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  1. Jul 2018
    1. On 2017 Feb 05, Stuart RAY commented:

      I appreciate Prof Pybus' response, and have no objection to this use of the "Simplot" name; I was just providing context.


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    2. On 2017 Feb 01, Oliver Pybus commented:

      I named the method "Deep Simplot" in homage to the very popular Simplot program. I apologise to Prof Ray and his colleagues for (i) not seeking their permission to use this term and (ii) not citing the original Simplot paper. To avoid confusion I recommend that, in future, the method described by our paper is referred to as "deep divergence plotting". My thanks to Prof Ray for bringing this issue to my attention.


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    3. On 2017 Jan 31, Stuart RAY commented:

      As the author of Simplot (Lole KS, 1999) I infer that the "Deep Simplot" method described was named after Simplot; it also shares characteristic display elements (as seen in figure 3b). Of course, the bootscanning approach that I implemented in Simplot was pioneered by Mika Salminen et al (Salminen MO, 1995, which is cited by Iles et al.).


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    1. On 2015 Aug 12, Víctor M. Baizabal-Aguirre commented:

      The PLKO1-GSK3beta1 and PLKO1-GSK3beta2 vectors used in our work were successfully used in a previous report by Yoeli-Lerner et al. (2009). As in our study, these authors were also able to fully silence the GSK3beta isoform (PMID: 19258413, see Figures 1A and 3A). Most of the studies on GSK3-dependent regulation of beta-catenin have used unspecific inhibitors that affect both GSK3 isoforms. Therefore, the contribution of GSK3alpha and GSK3beta to the regulation of beta-catenin is an issue that remains open. In this regard, Yu et al. (2003) reported that specific gene silencing of GSK3alpha or beta by siRNA expression vectors induces the stabilization of beta-catenin in P19 mouse embryonic carcinoma cells (PMID: 12597911, see Figure 5). As to the effect of GSK3 silencing on beta-catenin, results published in 2009 by Mamaghani et al., demonstrated that GSK3alpha or beta inhibition by siRNA increased the stabilization of beta-catenin in pancreatic cancer cells (PMID: 19405981, see Figure 3A). In contrast, Ryu et al., (2012) reported that specific GSK3alpha inhibition by siRNA decreased beta-catenin levels in human gastric cancer cells (PMID: 22328534, see Figure 3E). These findings indicate that complete removal of GSK3alpha or GSK3beta, as in our work, affect the relative abundance of beta-catenin and that GSK3alpha and GSK3beta alter in different ways the stabilization of beta–catenin, depending on the type of cell.


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    2. On 2015 Aug 04, Jim Woodgett commented:

      Figure 3 appears to be missing panel B (beta-catenin blot).

      The RNAi knockdowns here are remarkably efficient and it looks from the legend as though only one siRNA was used (although in the methods 3 alpha sequences and 2 beta sequences are listed). Figure 5 shows essentially complete removal. Blowing up the figure reveals some image artifacts. Typically, even complete inhibition of either GSK-3alpha or GSK-3beta has no effect on beta-catenin as the other isoform compensates fully (Axin is present at far lower concentrations that either isoform of GSK-3 and is the limiting factor in beta-catenin phosphorylation).


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    1. On 2015 Dec 21, Will Rowe commented:

      SEAR is now available for use as an App on the BaseSpace platform (Illumina).

      This iteration of SEAR has been updated, changes include:

      • The use of the open source VSEARCH (instead of USEARCH).

      • New result output.

      Please try it at:

      https://basespace.illumina.com/apps/2083081/SEAR-Antibiotic-Resistance

      Finally, the SEAR source code (for the App, Docker container image and original code) is available on GitHub:

      https://github.com/wpmr2/SEAR


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    1. On 2016 Dec 05, Anne Carpenter commented:

      As senior author on this paper, I report an error on page 10: the words "after cell fixation with 16% paraformaldehyde" should be replaced by "after cell fixation with 3.2% formaldehyde".


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    1. On 2015 Jul 25, David Keller commented:

      This just in: pioglitazone proved futile for slowing the progression of Parkinson's disease

      A large double-blind placebo-controlled randomized phase II study has proved pioglitazone futile for slowing the progression of early Parkinson's disease [1]. Pioglitazone is the only widely-prescribed thiazolidinedione ("glitazone") since the FDA placed safety restrictions on the use rosiglitazone (Avandia).

      Glitazones now join the ranks of disproved neuro-protectants, including creatine, co-enzyme Q10, vitamin E and minocycline. Back to the laboratory....

      Reference:

      1: NINDS Exploratory Trials in Parkinson Disease (NET-PD) FS-ZONE Investigators. Pioglitazone in early Parkinson's disease: a phase 2, multicentre, double-blind, randomised trial. Lancet Neurol. 2015 Aug;14(8):795-803. doi: 10.1016/S1474-4422(15)00144-1. Epub 2015 Jun 23. PubMed PMID: 26116315.


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    2. On 2015 Jul 23, David Keller commented:

      Exenatide, a different kind of diabetes drug, also exhibits activity against Parkinson's disease

      The type-2 diabetes drug exenatide is in the category of incretin mimetics, and is not a thiazolidinedione ("glitazone") like the drugs in this study by Brauer and colleagues. Exenatide lowers blood sugar by raising levels of endogenous insulin, among other effects. It also has exhibited symptomatic benefits in Parkinson's disease, in a prospective randomized interventional trial [1], with persistent motor and cognitive benefits which suggest possible disease modification. Exenatide can be used concomitantly with glitazones, and such use should be accounted for in this glitazone study, to avoid skewed results. For example, if the percentage of glitazone patients taking exenatide was higher than the percentage of placebo patients taking exenatide, then the apparent benefits of glitazone use may have been all or partly due to this imbalance in the use of exenatide. Was this possibility controlled for?

      Reference:

      1: Aviles-Olmos I, Dickson J, Kefalopoulou Z, Djamshidian A, Kahan J, Ell P, Whitton P, Wyse R, Isaacs T, Lees A, Limousin P, Foltynie T. Motor and cognitive advantages persist 12 months after exenatide exposure in Parkinson's disease. J Parkinsons Dis. 2014;4(3):337-44. doi: 10.3233/JPD-140364. PubMed PMID: 24662192.


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    1. On 2017 Jun 28, Raphael Levy commented:

      A response from Chad Mirkin. Well, nearly: a section of William Briley's PhD which starts with: "Though the endosomal escape of SNA nanostructures such as the Nanoflare and stickyflare is evident based upon their ability to provide sequence-specific information regarding RNA levels and locations within cells, one researcher [That’s me!] has concluded that SNAs cannot escape from endosomes.[75] That researcher is ignoring the many papers now that use such architectures for sequence-specific cell-sorting experiments." More here


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    2. On 2015 Nov 17, Raphael Levy commented:

      David Mason and myself submitted a letter to the Editor of PNAS regarding that article. It was however deemed not to "contribute significantly to the discussion of this paper" by the editorial board, and therefore publication was declined. I leave it to the readers of PubMed Commons to decide: the letter was published as a PrePrint on bioRxiv. Our article argues that Briley et al own data show that the Sticky-Flare remain in endosome where they get degraded by nucleases (and therefore cannot report on RNA level and localisation).


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    3. On 2015 Nov 17, Raphael Levy commented:

      The PNAS article itself includes a sentence which could be interpreted as SmartFlare advertising: "As a result, the Nanoflare has grown into a powerful and prolific tool in biology and medical diagnostics, with ∼1,600 unique forms commercially available today (sold under the SmartFlare trade name)." Furthermore, there is a Sticky-Flare patent which was published around a month before the communication of the PNAS article.


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    4. On 2015 Sep 28, George McNamara commented:

      I posted this on PubPeer, https://pubpeer.com/publications/25CC01C366B9593D1686A78B52461F#fb36935

      The Briley et al 2015 paper is deficient in methods - what is the length of the new product? what are the design criteria for specificity? how are the spherical nucleic acids constructed? Is there a mechanism by which the flare gets kicked off the SNA? I suggest PNAS explicitly require self contained full methods and materials in manuscripts they accept. The details can be in the supplemental file, and can both provide full details and cite -- or even quote -- earlier work.

      The Briley COI statement states: "The authors declare no conflict of interest.". The authors and their University previously commercialized NanoFlare/SmartFlare - is PNAS sure they have not submitted patent applications for Sticky-Flare and intent to make money from it = financial interest. I am fine with commercialization of products, but if this is an advertisement for a future product, the authors should be honest in their COI an PNAS should mark the paper as an advertisement.

      Citation for commercialization: "NanoFlares have been very useful for researchers that operate in the arena of quantifying gene expression. AuraSense, Inc., a biotechnology company that licensed the NanoFlare technology from Northwestern University, and EMD-Millipore, another biotech company, have commercialized NanoFlares. There are now more than 1,700 commercial forms of NanoFlares sold under the SmartFlare name in more than 230 countries." http://www.northwestern.edu/newscenter/stories/2015/07/new-tool-for-investigating-rna-gone-awry.html#sthash.GwI4hbRx.dpuf

      One of their patents is US8507200B2 https://patents.google.com/patent/US8507200B2/en?q=mirkin&q=nanoflare


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    1. On 2017 Mar 27, Christopher Southan commented:

      There was tutorial on this theme at the 2017 International Conference on Trends for Scientific Information (ICIC) https://www.slideshare.net/Haxel/icic-2017-tutorial-digging-bioactive-chemistry-out-of-patents-using-open-resources/1


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    2. On 2016 Jan 25, Dimitrios Tzalis commented:

      The ELF Public Compound Collection (PCC) is a very unique collection of compounds that are already synthesized and available for screening within ELF Screening Campaign. The goal of the paper was to compare the PCC with other compounds that are available for biological screening or that were actually screened. That is why, with a full awareness, we have analyzed the PCC against part of the PubChem collection called MLP of NIH, commercially available Maybridge and already tested compounds represented by ChEMBL. It might be interesting to collate the PCC and the 15 millions of patent-extracted compounds, in respect to broadly understood novelty, but we wanted to avoid the contamination of our comparison with theoretical compounds. In such a way the work is much more consistent. Nevertheless, thank you for your valuable comment and we can think of extending our novelty check also in respect to theoretical compounds in the future analysis since our collection is still growing. We believe that by focusing on exploring underrepresented chemical space of spiro-compounds and saturated, fused hetero rings we are offering a very competitive and unprecedented collection.


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    3. On 2015 Jul 22, Christopher Southan commented:

      This is part of a special issue "From chemistry to biology database curation" http://www.sciencedirect.com/science/journal/17406749/14/supp/C. The PubMed ID series is 26194580-6.


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    1. On 2015 Jul 22, Ellen M Goudsmit commented:

      As one of the main authors, I note that the PACE trial could not have used the London criteria for ME, as often claimed, as there should have been at least one difference between the groups, and this was not reported. Ergo, they did not use the criteria for ME correctly and the results from the trial can not be extrapolated to this population. The attitude of the authors towards ME and the scientists who specialise in this disease is disappointing.


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    1. On 2015 Oct 03, Seyed Moayed Alavian commented:

      Dear All, I would like to declare that receiving the medical services may be an important risk factor for acquiring the HCV and HBV infections in Middle East Countries. Yours Alavian SM


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    1. On 2016 Jan 14, Noman Shahzad commented:

      The article is the highest level of evidence available on the topic. Reading the article, I am interested in knowing more about those who developed hernia. Like group wise details of how many of them were symptomatic, how many required surgical repair. Was there any statistical difference in detection method used to diagnose hernia? Was there difference in Quality of Life of those who developed hernia in traditional vs small suture group? This information will help in understanding the impact of change in technique from patient perspective. Clustering leading to increased risk of alfa error is a frequent problem of multicentric trials, it will be informative if information could be provided if adjustment was made for clustering in statistical analysis.


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    2. On 2016 Jan 10, Noman Shahzad commented:

      None


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    1. On 2015 Jul 24, Jay Kaufman commented:

      Etsuji Suzuki of Okayama University, Japan contacted the authors to note that on page 3 of the article, the text states that that conditioning on CVD in Figure 1c opens four paths that bias the effect of obesity on mortality. However, the first of these paths that is listed in the text (obesity <- smoking -> CVD -> mortality) does not in fact contain a collider on the path, since no nodes are entered and exited through arrowheads. Therefore, the text should state that there are three such paths, not four. This error in the exposition of the problem changes neither the quantitative results nor the conclusions of the paper.


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    1. On 2015 Dec 11, Mark Johnston commented:

      Interactive protocols from this article are freely available at protocols.io.


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    1. On 2015 Sep 29, George McNamara commented:

      Why does this paper's authorship section state:

      Conflict-of-interest disclosure: The authors declare no competing financial interests.

      when one of the authors works for the company that supplied the CB-839 drug feature in the abstract and key points?

      http://www.calithera.com/programs/cb-839/

      Genetically mandated alterations in the fundamental metabolic pathways of tumors often cause a dramatic rise in the uptake of the nutrients glucose and glutamine. Removal of glutamine leads to a substantial reduction in cell growth or induces cell death in certain types of cancer cells, indicating that these cells are dependent on, or “addicted” to, glutamine. Normal cells do not show this pronounced dependence on glutamine. The enzyme glutaminase, which converts glutamine to glutamate, has been identified as a critical choke point in the utilization of glutamine by cancer cells. CB-839 is a potent, selective, reversible and orally bioavailable inhibitor of human glutaminase.


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    1. On 2015 Oct 24, Geriatric Medicine Journal Club commented:

      This article was critically appraised at the October 2015 Geriatric Medicine Journal Club (follow #GeriMedJC on Twitter). One of the study authors was also present for the tweet chat discussion! The full discussion can be found at: http://gerimedjc.blogspot.com/2015/10/october-2015-gerimedjc.html?spref=tw This is a very interesting study which separates common beliefs about older people in general as different from older patients in health care settings. This will help inform policies and education strategies to improve care for older adults.


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    1. On 2015 Aug 16, Xiang Ming commented:

      Thanks very much for Murtaugh’s careful review. According to your comment, we make following explanations. 1. The pancreas photos on the first row of Fig.5A showed that the surgical removal of tissues do not include intestine. After being photographed, the tissues were embedded in paraffin, so we could ensure that all sections assessed in this paper are from pancreas. 2. As you said “the treatment might have induced cancers of an intestine-like pathology”, we should explain that a great quantity of non-tumor components existed in pancreatic cancer including stromal cells and lymphocytes. The immunohistochemical analysis in Figure.5 was consistent with this pathological characteristic which was similar to intestine-like pathology. 3. In our study, the malignant cell could secrete a small amount of amylase (Fig.5A). This also prove that the treatment didn’t induce cancers of an intestine-like pathology. On the other hand, the Ki67 is mainly expressed in the malignant acinar cell nucleus, so high levels of Ki67 expression could support our conclusion that Reg3g could promote proliferation in acinar cells


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    2. On 2015 Jul 30, L Charles Murtaugh commented:

      While this is an interesting study, and the role of REG genes in pancreatic cancer is arguably understudied, the conclusions of this paper are tempered by irregularities in the histological analysis. Only one study group developed pancreatic cancer in this study, namely the high-dose pReg3g + DMBA treatment, referred to as HA10R. Inspection of the histology data presented for the HA10R group (Fig. 5A) reveals that several of the most relevant images (H&E staining, Ki67 and cytokeratin-19), for this group specifically, appear to be taken from sections of the intestine rather than the pancreas. While, in principal, the treatment might have induced cancers of an intestine-like pathology, this would not explain the clear organization of proliferative crypts and non-dividing villi, apparent from Ki67 staining. This raises doubts about the quantitative analysis of these and other variables, in Fig. 5B, as well as about the overall conclusion that treated mice developed cancer of the pancreas.


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    1. On 2015 Dec 05, David Keller commented:

      Patient-oriented result: response rate to magnetic stimulation was the same as to placebo

      This study of repetitive transcranial magnetic stimulation (rTMS) was designed to test the hypothesis that rTMS would result in a "statistically significantly greater percentage of responders to treatment in an active rTMS group compared with a placebo rTMS group" [1]. A relatively new metric called the Tinnitus Functional Index (TFI) was used to measure response to treatment. The TFI rated 18 of the 32 subjects actively treated with rTMS as responders to treatment (56%), while only 7 of the 32 subjects treated with sham therapy were rated as responders (22%). These two rates differed significantly, which was pre-specified in the Objectives section as defining a successful outcome.

      However, 7 of the 18 treated subjects rated as "responders to therapy" using the TFI scale nevertheless believed they had received sham therapy, implying that they did not perceive any treatment benefit beyond the placebo effect. When a subject states that his treatments seemed like sham therapy, providing only placebo-strength benefit, this is important information. Since it is a direct expression of the subject's assessment of the efficacy of rTMS therapy, it has more validity than a contrived metric like the TFI, from a patient-oriented perspective.

      The data in e-Table 12 indicate that, of the 32 subjects who received active rTMS treatments, only 11 correctly guessed they had received active therapy at the end of the last treatment, which implies that only 11 out of 32 actively-treated subjects (about 34%) noted perceptible improvement in their tinnitus symptoms. Coincidentally, 11 of the 32 placebo-treated subjects (also 34%) guessed that they had received active rTMS therapy, which equals the placebo effect. Thus, active rTMS treatments had the same response rate as sham therapy, equal to the placebo effect of 34%.

      Conclusion: rTMS is no more effective than placebo for treating tinnitus, when assessed by subjects after a full course of treatments, based on their perception of whether they received active or sham therapy. The advantage of this assessment is that it eliminates uncertainty about the accuracy and clinical relevance of the TFI metric, because the assessment of treatment benefit came directly from the subjects themselves.

      Reference

      1: Folmer RL, Theodoroff SM, Casiana L, Shi Y, Griest S, Vachhani J. Repetitive Transcranial Magnetic Stimulation Treatment for Chronic Tinnitus: A Randomized Clinical Trial. JAMA Otolaryngol Head Neck Surg. 2015 Aug;141(8):716-22. doi: 10.1001/jamaoto.2015.1219. PubMed PMID: 26181507.


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    2. On 2015 Nov 29, David Keller commented:

      38% of the reported "responders to therapy" thought they had been randomized to placebo & reply by author

      At the end of this study, only 11 of the 32 subjects who received active treatment for tinnitus guessed that they had received active treatment. The remaining 21 subjects who were actively treated guessed that they had received placebo (sham treatments).

      18 of the 32 actively treated subjects were rated as "responders" to therapy by Folmer et al. Thus, 7 of the actively treated subjects, who were rated as "responders" to therapy, thought they had received sham treatments. Bottom line: 7 of the 18 tinnitus sufferers (38%) who were reported to be "responders to therapy" actually did not perceive any benefit.

      Tinnitus is a subjective phenomenon. I contend that, by definition, a responder to tinnitus therapy cannot believe that he received sham therapy. If a subject thinks he was treated with sham therapy, he did not perceive any benefit, and he cannot be a reported to be a "responder to therapy". This is the essence of my criticism of this study, and it has not been addressed.

      Addendum (12/4/2015): Yesterday, in reply to the above comment, Dr. Folmer issued the following statement (start of quotation):

      In our study, participants were categorized as "responders" or “non-responders” to TMS treatment based solely on the change in their TFI score from baseline to post-TMS assessment – this is stated in the article.

      The definition of "responders" or “non-responders” we used had nothing to do with

      1. Whether or not study participants “perceived” any benefit if that was based on anything else but their TFI score
        
      2. Study participants’ guesses that they received active or placebo rTMS  
        

      These are separate issues. You can debate, discuss or disagree with them, but they remain separate issues and definitions as specified in the article.

      --Robert L. Folmer, Ph.D. (end of quotation)


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    1. On 2015 Oct 05, Eiko Fried commented:

      A recent study published in Nature by the CONVERGE consortium [1] identified two Single Nucleotide Polymorphisms (SNPs) for Major Depressive Disorder (MDD) that replicated across two samples of Han-Chinese women with recurrent depression. The report was accompanied by an editorial [2] that hailed the findings as biologically and diagnostically relevant, suggesting that large-scale exploratory genome-wide studies offer enticing prospects towards aiding diagnosis and the development of new drugs.

      We disagree with the editorial’s interpretation (and most of the media coverage) of these CONVERGE results, which also contrast with the careful phrasing of the authors themselves. Although the two SNPs discovered in the comparatively homogenous CONVERGE sample did replicate in a similarly ascertained group, the editorial fails to mention that they did not in the more heterogeneous Psychiatric Genomics Consortium (PGC) data also examined by the authors. Moreover, in polygenic risk score analysis, the genetic signal in the PGC sample explained less than 0.1% of disease risk in the CONVERGE data, implying a fundamental lack of overlap in genetic risk signal across samples.

      The laudable effort of the CONVERGE consortium to ensure genetically and phenotypically homogenous samples confirms the elusiveness of the genetics of MDD. Hailing the results as robust insights into the biology of depression detracts from the true scientific relevance of the study: genetic effects for MDD are, even in large homogenous samples, small and do not generalize.

      Given the hitherto negative results of genetic MDD studies [4,5], slogging along on this current road of ever-larger samples and discovering at best small effects is not an alluring prospect, especially so considering that these effects are likely not specific to MDD [6]. Instead, we suggest revising complex psychiatric phenotypes such as MDD that were transferred unquestioningly from psychiatry to genetics. Incorporating recently proposed network models [7], symptom- rather than syndrome-level analyses [8], and the development of new instruments that tap variation along the entire continuum [9,10] (i.e., in both "cases" and "controls") offer promising ways forward.

      References

      • 1.Cai, N. et al. Sparse whole-genome sequencing identifies two loci for major depressive disorder. Nature 523, 588–91 (2015).

      • 2.Ledford, H. First robust genetic links to depression emerge. Nature 523, 268–269 (2015).

      • 3.Keener, A. B. Genetic Variants Linked to Depression. Sci. (2015).

      • 4.Hek, K., Demirkan, A., Lahti, J. & Terracciano, A. A Genome-Wide Association Study of Depressive Symptoms. Biol. Psychiatry 73(7), 667–78 (2013).

      • 5.Daly, J. et al. A mega-analysis of genome-wide association studies for major depressive disorder. Mol. Psychiatry 18, 497–511 (2013).

      • 6.Kendler, K. S. ‘A gene for...’: the nature of gene action in psychiatric disorders. Am. J. Psychiatry 162, 1243–52 (2005).

      • 7.Cramer, A. O. J., Kendler, K. S. & Borsboom, D. Where are the Genes? The Implications of a Network Perspective on Gene Hunting in Psychopathology. Eur. J. Pers. 286, 270–271 (2011).

      • 8.Fried, E. I. & Nesse, R. M. Depression sum-scores don’t add up: why analyzing specific depression symptoms is essential. BMC Med. 13, 1–11 (2015).

      • 9.Lee, S. H. & Wray, N. R. Novel genetic analysis for case-control genome-wide association studies: quantification of power and genomic prediction accuracy. PLoS One 8, e71494 (2013).

      • 10.Van der Sluis, S., Posthuma, D., Nivard, M. G., Verhage, M. & Dolan, C. V. Power in GWAS: lifting the curse of the clinical cut-off. Mol. Psychiatry 18, 2–3 (2012).

      Authors

      • EI Fried, University of Leuven, Belgium

      • S van der Sluis, VU Medical Center, Amsterdam, The Netherlands

      • AOJ Cramer, University of Amsterdam, The Netherlands

      PDF of this commentary (DOI: 10.13140/RG.2.1.3480.4963) available at: http://eiko-fried.com/wp-content/uploads/Nat_Correspondence_blog.pdf


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    1. On date unavailable, commented:

      None


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    2. On 2015 Sep 23, Angelo Gaitas commented:

      The entire response appears in the PLOS1 comment section under response: http://www.plosone.org/article/comments/info:doi/10.1371/journal.pone.0127219

      In two recent articles [1, 2] two techniques for removing or inactivating blood borne pathogens were introduced. The initial experiments were performed in vitro under simplified conditions. First, the primary achievement of the PDT work deserves clarification [1]. PDT is a powerful therapeutic modality, but its clinical application has been hampered by the inability of light to penetrate deep layers of the tissue, which is mainly due to hemoglobins in the blood readily absorbing photons. Utilizing a millimeter- diameter transparent tube for extracorporeal blood circulation allows PDT to function well despite the presence of hemoglobins in blood. Another point that deserves clarification is that the tube capturing device is not a microfluidic device [2]. This technique can be adapted using existing medical tubing without the need for complicated microfluidics and micro-fabrication. The device is a medical tube that has been chemically modified using simple steps to adapt the internal surface for cell capturing. 
      
      We would like to take this opportunity to respond to concerns brought up in [3]. We start off by addressing concern (1), which speculates about the possibility of overheating during the use of near IR light. Our control data (Fig.3 and Fig.4 of [3]), confirmed that controls illuminated without photosensitizer-antibody conjugates did not undergo cell death, whereas those with photosensitizer-antibody conjugates underwent significant cell death under identical conditions. Thus it is clear from our data that temperature did not affect the outcome. It has been shown that 660 nm irradiation is safe and effective [4-6]. 
      
      Moving on to concern (2) part (a) that brings up the problem of using the CD-44 antigen as a target. Limitations of antibody specificity are common knowledge and not unique to CD-44, but to all antibodies. To our knowledge, a targeting method that exclusively binds only to cancer cells does not yet exist, making the use of such a compound an unreasonable standard for publication. We used CD-44 antibody to demonstrate feasibility. As targeting methodologies advance and better selectivity to target cells becomes available, this technique will have improved selectivity. Our experiments were designed to avoid non-specific damage to other cells by pre-staining pure cancer cells with the photosensitizer-antibody conjugates and subsequently removing extra free conjugates before spiking into blood (described in detail in [1]). This elimination of the possibility of side effects due to undesired binding to other blood cells and excess free photosensitizer-antibody conjugates precluded the need for a toxicity study, particularly because we were at the proof-of-principle stage.
      
      Part (b) of concern (2) suggests that we may have caused non-specific damage to non-cancerous cells by ROS' convection in the blood stream. We believe that this is highly unlikely. One of the authors has been conducting research focusing on ROS and PDT for years, in collaboration with other researchers [7-15]. This research demonstrated that PDT is extremely selective to targeted cells [13]. 
      
       Part (c) of concern (2) states that we should have used additional cytotoxicity assays, such as Annexin V, TUNEL, and MTT. However, because none of these techniques are cell-type specific, they would be useless for the particular objective they were suggested. Once our line of investigation reaches a more mature stage, we plan to undertake more useful studies, such as applying separate fluorescent tags, or radio labels, in addition to a cell viability assay and analyzing cell death with a cell sorting technology, such as FACS, MACS, density gradient centrifugation, etc.  
      
      Concern (3) is that the capturing work [2] lacked purity confirmation concerning non-specific capturing of blood cells. Though purity confirmation is critical in diagnostic testing, our work was strictly limited to in vitro conditions, using spiked pure PC-3 cells as a model. To visualize and quantify PC-3 cells in the presence of whole blood, PC-3 cells were pre-labeled using a fluorescence tag (Calcein AM) and the extra free dye was subsequently removed before spiking PC-3 cells into blood. Because only PC-3 cells can have fluorescence in the blood mixture, and because quantification was based on fluorescing cells, false-positive results from other blood cells can be reasonably excluded. Furthermore, if other blood cells were captured but not identified by our detection method our data would then indicate that the simple tube captured cancer cells despite being blocked by other blood cells. If our technique were applied to CTC diagnosis, independent isolation procedures could be used to ensure the purity of captured cells. In contrast, if used for therapy, the purity of captured cells would not be as critical, provided that CTCs are effectively removed. If, by chance, capturing is hampered by accumulation of non-specific binding in filtering the entire blood volume, this issue can be addressed with strategies such as scaling up the tube and carefully determining the tube dimensions, flow rate, frequency of tube replacements, etc. 
      
      Finally, concern (4), points out that the experimental conditions were not translatable to clinical applications. Part (a) regards scaling up the system to show high throughput. The concept of extracorporeal cleansing of the entire blood volume has been used for years in cases such as hemodialysis. We already are working on optimizing the technique for larger blood volume processing. Part (b) of concern (4) discusses the static no-flow condition as being unrealistic. This issue was brought up during the review process, and we provided with our results showing data under constant flow conditions by peristaltic pump (to be published in future publication). The reviewers agreed that the use of a no-flow condition as a conservative approach during a proof-of-concept stage was appropriate.
      
      Despite its preliminary nature, we believe that our work communicates novel ideas, an important objective of research and publication. Given the number of research articles dealing with diagnostics and microfluidics, perhaps a further point of confusion came about by thinking of our work in those terms. We want to clarify that diagnostics were not the primary objective in our work. Furthermore, as it becomes evident by this response our experimental design was carefully devised to minimized unnecessary interferences. We hope that this response mitigates any confusion and addresses the concerns raised. 
      
      1. Kim G, Gaitas A. PloS One. 2014;10(5):e0127219-e.
      2. Gaitas A, Kim G. PLoS One. 2015;10(7):e0133194. doi: 10.1371/journal.pone.0133194.
      3. Marshall JR, King MR. DOI: 101007/s12195-015-0418-3. 2015;First online.
      4. Ferraresi C, et al. Photonics and Lasers in Medicine. 2012;1(4):267-86.
      5. Avci P, et al. Seminars in cutaneous medicine and surgery; 2013.
      6. Jalian HR, Sakamoto FH. Lasers and Light Source Treatment for the Skin. 2014:43.
      7. Ross B, et al. Biomedical Optics, 2004
      8. Kim G, et al. Journal of biomedical optics. 2007;12(4):044020--8.
      9. Kim G, et al Analytical chemistry. 2010;82(6):2165-9.
      10. Hah HJ, et al. Macromolecular bioscience. 2011;11(1):90-9.
      11. Qin M, et al. Photochemical & Photobiological Sciences. 2011;10(5):832-41.
      12. Wang S, et al. et al. Lasers in surgery and medicine. 2011;43(7):686-95.
      13. Avula UMR, et al.Heart Rhythm. 2012;9(9):1504-9.
      14. Kim G, et al. R. Oxidative Stress and Nanotechnology, 2013. p. 101-14.
      15. Lou X, et al. E. Lab on a Chip. 2014;14(5):892-901.
      16. https://www.roswellpark.org/patients/treatment-services/innovative-treatments/photodynamic-therapy.
      17. Yin H, et al. Artificial organs. 2014;38(6):510-5.
      18. Yin H, et al. Journal of Photochemistry and Photobiology B: Biology. 2015.


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    3. On 2015 Aug 29, Michael King commented:

      Our recent commentary discusses this paper:

      http://link.springer.com/article/10.1007/s12195-015-0418-3

      In cancer research, the discovery and study of circulating tumor cells (CTCs) have seemed to open a world of possibilities. We now have the potential to gain cellular and molecular understanding of individual cases of metastatic cancer without invasive procedures. This area of research is, however, not without some basic pitfalls. In this commentary, we address some of these pitfalls by considering two recent examples in the published literature and discuss ways to overcome their limitations with the hope of informing those who may be entering the growing field of CTC research. Careful research design should always be followed to prevent incomplete or misleading studies from entering the literature, and thereby avoid setting back this burgeoning field.


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    1. On 2016 Nov 02, Eiko Fried commented:

      What the study actually found is this: none of the 171 serum proteins differed between MDD cases and controls, seeing that none of the 171 markers differed after controlling for multiple testing.

      The authors do not report this most important core finding of their study in the abstract, and instead claim that 28 of the 171 markers differed between the two groups. I struggle to understand why the authors chose to report the uncorrected findings instead of the proper statistical results — the corrected findings – in the abstract.


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    1. On 2017 Jan 19, Jameson Voss commented:

      This paper identifies an interesting association between calories in the national food supply per capita and average population body weight. It was recently recognized by an independent review as an important work in the field. The recognition is appropriate as the analysis was based on worldwide comprehensive data, stratification of countries by income, assessment of longitudinal changes, incorporation of a mathematical model of weight gain and other strengths. The association is plausible and builds on other work connecting the food supply and body weight.

      Despite these strengths, readers should be cautious about how they interpret the title and discussion. First, the title uses a causal phrase “major driver” which was also echoed in the recent review (linked above). Readers should be aware this title refers to an ecologic association and avoid making causal inferences about outcomes at a population or individual level based on this type of observational study design. Secondly, readers might misinterpret the term “major” as though the authors found the association to be stronger than other obesity correlates, but the paper did not provide an empiric comparison with any other obesity correlate. Finally, the discussion about opportunities for future research could also be misunderstood. The authors argue against testing the association with a study that moves people to different food systems by claiming it would be impractical. That might discourage readers from pursuing probative designs like “packet randomized experiments” which can utilize quasi-random assignment of migration (e.g., international adoptions, foreign exchange students, military household moves, etc.). If done properly, these studies can eliminate confounding among individuals, but confounding at the location persists. When participants are assigned to locations with higher energy in the food supply, they would simultaneously face other local, regional, or national exposures. That is, all exposures found at a location are assigned together as a single “packet,” so national food supply could be confounded by other differences between places (e.g., infrastructure, hygiene, ambient light, pollution, temperature, etc.).

      There are empiric methods of handling packet level confounding, but it can be eliminated with a design called cluster randomization. Within the United States, an industry affiliated organization has worked to lower national per capita food energy supply and this has coincided with worsening average waist circumference, but it cannot be known if these trends are caused by the lower energy available in the food supply (as discussed here). Instead, system interventions could be randomized to different systems or subsystems or implemented at randomized start times or randomized locations.

      While ecologic studies have confounding at both the location and subject level, there is still possible utility for prediction if the confounding remains stable across periods. Interventions, on the other hand, work based on causation and can have unintended consequences. Thus, readers should continue to feel encouraged to investigate net harms and benefits of altering the food supply.

      The views expressed in this comment are those of the author and do not necessarily reflect the official policy or position of the Air Force, the DoD, or the U.S. Government.


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    1. On 2017 Aug 02, Gregory Francis commented:

      The journal Perspectives on Psychological Science used to have an on-line commenting system. They seem to have discontinued it and removed all past comments. In April 2013, I published a comment on this article. I reproduce it below.

      Simonsohn's arguments are without merit

      Simonsohn presents two arguments to discredit the publication bias analyses I have published over the past year. Neither of these arguments are convincing to me, but some people seem to be taking them seriously. I treat them in more depth in a recent paper (Francis, 2013), but it might be helpful to have a comment with the article itself.

      Whether to ignore data that appears to be biased

      I have argued that sets of experiments that appear to be biased should be treated as "non-scientific" and be replaced by new experiments. Such a recommendation is admittedly a cautious approach, but I feel that such caution is warranted for scientific investigations; especially when it is fairly easy to gather new data. For example, in my POPS article, to which Simonsohn's directs his reply, the publication bias analysis suggests that the aversiveness memory effects reported by Galak & Meyvis (2010) appear to be biased. My recommendation to ignore their data is not so very harsh, since it is quite easy for interested researchers to gather new (unbiased) data and determine the magnitude of the effect. There may be situations where gathering new data is more difficult and such situations might justify efforts to try to mitigate effects of bias. However, existing statistical methods are not very good at compensating for bias, and they do not attempt to compensate for other types of questionable research practices that can also trigger the bias analysis.

      Simonsohn raises an interesting issue about the relation between statistical significance and practical significance. His example of a literature of 100 studies, all with p<.05 and power of 97%, highlights a particularly bad property of bias. As Simonsohn describes it, bias appears to be present (the bias test gives .97<sup>100</sup> = 0.0476) but small because, given the power values, one would expect just three non- significant findings out of 100 experiments. Thus, Simonsohn concludes the bias is small because it appears to be small relative to what is published. Such a view would be fine if there was no reason to suspect bias, but it is difficult to maintain this view given that the analysis suggests there is bias. The bias could be small, but there may have been another 100 non-significant findings that were suppressed, in which case the bias is quite large. There is no way for a reader to know the extent of the bias.

      One of the fundamental goals of science is to reduce uncertainty in measurements, but the appearance of bias introduces uncertainty about the experimental results and conclusions. The responsibility for making a strong scientific argument rests with the authors; and if their results appear to be biased, then it is difficult to make such an argument.

      Cherry picking

      Simonsohn charges that my analyses are ironically biased with the very practice that is used to produce the biased experiment sets that I criticize. To this charge, I reply "guilty", but I have an explanation. There are different types of biases; and some biases misrepresent empirical data, while other biases are simple byproducts of scientific exploration. Understanding the differences between these types of bias is very important.

      Biases that misrepresent the data

      If a researcher runs 10 direct replication experiments and gets six experiments to reject the null hypothesis and four experiments to not reject the null, then bias is going to be introduced if only the six significant experiments are reported. (Whether such bias will be detected by the bias analysis depends on the estimated power of those experiments.) A meta-analysis across those six published experiments will almost surely overestimate the true effect size, because the experiments with samples having small effect sizes tend to not reject the null. When the experiments are connected by a theoretical link (in this case by the idea that the experiments are measuring the same effect size), this kind of bias misrepresents the true state of nature, which is clearly a problem for a scientific field.

      Biases that do not misrepresent the data

      If a researcher runs 10 experiments on unconnected topics (separate studies on afterimages, reading rates, Stroop reaction times, aversiveness ratings of memories, etc.) and gets six experiments to reject the null and four experiments to not reject the null, then a bias is introduced by publishing only the six significant experiments. However, this kind of bias is mostly benign because it does not misrepresent the published data. Suppose the study on afterimages finds a significant effect with a standardized effect size of 0.6. None of the other experiments tell us anything about the effect size of afterimages, so whether those experiments are published or not does not influence the scientific conclusions that are drawn about afterimages from this published study.

      The publication bias analyses I have reported over the past year have the latter type of bias. Whether other papers have bias or not is irrelevant to the conclusion about bias for Galak & Meyvis (or any other paper). This is not to say that the bias analysis cannot make a Type I error and conclude bias when it does not exist. If we cannot tolerate making a Type I error, then we should not make decisions.

      An important caveat is that the selective reporting of my analyses prohibits us from estimating the proportion of biased papers in the field. Trying to make such an estimate from the reported analyses changes the bias from being benign to one that misrepresents the data. Importantly, just because this particular interpretation is inappropriate does not mean that the individual analyses are inappropriate.

      In conclusion, Simonsohn's arguments are without merit. His claim that ignoring the data is unwise leads to scientifically vacuous arguments; and his claim of cherry picking is true but its meaning is misunderstood.

      Francis, G. (2013). Replication, statistical consistency, and publication bias. Journal of Mathematical Psychology. http://dx.doi.org/10.1016/j.jmp.2013.02.003

      Conflict of Interest: None declared


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    1. On 2015 Jul 15, Peter Hajek commented:

      The key question is what effect this has on cigarette sales. If it is reducing cigarette sales, it is a positive development.


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    1. On 2015 Jul 15, Holly Brothers commented:

      This is really interesting - I'll be happy to get access to the article. It reminds me of the RadioLab episode highlighting Jasper Lawrence who used hookworms to battle his hyperimmune responses (allergies and asthma) http://www.radiolab.org/story/91691-sculptors-of-monumental-narrative/.


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    1. On 2015 Dec 17, Peng Chen commented:

      I realize that you have work very hard to publish all these excellent papers! Good job! Well done! And, I love U :)


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    1. On 2015 Jul 22, BSH Cancer Screening, Help-Seeking and Prevention Journal Club commented:

      The HBRC journal club read with interest this paper that uses an innovative qualitative method to examine the barriers to colorectal cancer (CRC) screening experienced by people from medically under-served areas in the US. The paper offers an account of how macro level factors, such as the socio-political context, combine with individual level factors to determine uptake of CRC screening.

      The authors used a participatory research method and PhotoVoice technique to engage participants in the research project, which took place over several months and included training sessions, group meetings, and individual meetings. We felt that one of the strengths of this approach was that it allowed rapport to be built over time, and that participants could express themselves in ways other than by just verbalising their thoughts and feelings. The photos taken by participants served as the “jumping off point” for the group discussions, which we felt helped obtain a richer picture of what people have to go through in order to obtain screening. Using each participant’s photos as a catalyst for the discussions may have encouraged a more evenly distributed participation across participants, because each participant was expected to contribute to the meetings. Although many of the barriers mentioned in this paper focused on the costs of colonoscopy screening and may therefore not necessarily generalise to healthcare contexts that use different screening methods or are free at the point of delivery, such as in the UK, some of the opportunity costs mentioned by participants did resonate with the journal club and may be more widely applicable. For example, those undergoing flexible sigmoidoscopy screening in the UK may also be faced with the opportunity cost of having to take (potentially unpaid) time off work.

      We felt the authors could have commented more on the possible limitations of their study. The chosen study method required a great deal of commitment and active participation from participants. Although the researchers note that the Photovoice method may address shortcomings of other qualitative work in this field, which “may simply generate ‘impression management discourses’”, we felt that the method does not necessarily circumvent these discourses, but may just elicit more “crafted” image discourses. In addition, the high level of commitment expected from participants in the current study may mean that only those who were most highly motivated and health conscious self-selected to participate, which may limit the generalisability of the study findings. The authors chose to focus on the obstacles experienced by those who had been screened, but those may not necessarily be the same as the obstacles faced by people who have not screened. The HBRC journal club would encourage further study in samples of participants who are not engaged with screening. We also felt that the results were presented in a way that suggested a broad consensus among participants and wondered whether there were any dissenting voices? Some of us felt that a greater emphasis could have been placed on the experience of facilitators to screening uptake, although some felt that this was adequately addressed by discussing the importance of social support around the time of screening. Finally, we felt that the paper formed a good illustration of some of the barriers and facilitators to CRC screening that we already know about, but some of us felt that it did not offer many new insights, and wondered whether the wealth of data collected in the study could have generated any novel insights? We recognise that journal requirements may only allow for a limited discussion of all findings in a study, and we would argue that online supplements could make a valuable contribution to convey the results of this type of study, for example, as a photo gallery with accompanying quotations.

      In sum, the HBRC journal club really enjoyed reading this paper and feel that the Photovoice method is a great method for doing explorative research in certain groups, because of the high level of active involvement of participants in the research project, and the meaning and value added by their pictures which may complement verbal explanations of behaviour. This study shows that decisions about screening are not just up to the individual, but are made in a socio-political context that can help or hinder individuals to obtain screening, and has important implications for policy making in preventive healthcare.

      Conflicts of interest. We report no conflict of interests and note that the comments produced by the group are collective and not the opinion of any one individual.


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    1. On 2015 Jul 27, Chuan-Wei Jang commented:

      In the paper, we failed to specify the sources of some antibodies used in the additional experiments a reviewer requested after our initial submission. These antibodies are:

      H3K4me2: Active Motif, 39141

      CenpA: Abcam, ab33565

      TRF1: Alpha Diagnostic International, TRF12-A

      TRF2: Novus, NB110

      Beta-Actin: Abcam, ab8826


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    2. On 2015 Jul 16, Chuan-Wei Jang commented:

      The figures in the paper have been reduced in size and resolution in the print publication process, and thus some details are compromised in their final form. The original high resolution figures can be viewed or downloaded from here.


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    1. On 2017 Apr 12, Siegfried Hekimi commented:

      We obtained very different results that suggest that CLK-1 functions exclusively in ubiquinone biosynthesis and not in the nucleus to affect the mtUPR. In a paper entitled: A single biochemical activity underlies the pleiotropy of the aging-related protein CLK-1. By Liu et al. http://www.nature.com/articles/s41598-017-00754-z?WT.feed_name=subjects_energy-metabolism


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    1. On 2016 Aug 24, Ben Goldacre commented:

      This trial has the wrong trial registry ID associated with it on PubMed: both in the XML on PubMed, and in the originating journal article. The ID given is NCT0210086. We believe the correct ID, which we have found by hand searching, is NCT02100865.

      This comment is being posted as part of the OpenTrials.net project<sup>[1]</sup> , an open database threading together all publicly accessible documents and data on each trial, globally. In the course of creating the database, and matching documents and data sources about trials from different locations, we have identified various anomalies in datasets such as PubMed, and in published papers. Alongside documenting the prevalence of problems, we are also attempting to correct these errors and anomalies wherever possible, by feeding back to the originators. We have corrected this data in the OpenTrials.net database; we hope that this trial’s text and metadata can also be corrected at source, in PubMed and in the accompanying paper.

      Many thanks,

      Jessica Fleminger, Ben Goldacre*

      [1] Goldacre, B., Gray, J., 2016. OpenTrials: towards a collaborative open database of all available information on all clinical trials. Trials 17. doi:10.1186/s13063-016-1290-8 PMID: 27056367

      * Dr Ben Goldacre BA MA MSc MBBS MRCPsych<br> Senior Clinical Research Fellow<br> ben.goldacre@phc.ox.ac.uk<br> www.ebmDataLab.net<br> Centre for Evidence Based Medicine<br> Department of Primary Care Health Sciences<br> University of Oxford<br> Radcliffe Observatory Quarter<br> Woodstock Road<br> Oxford OX2 6GG


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    1. On 2016 Feb 29, Jim Johnson commented:

      Thanks Dave. Actually there are 2 related bioRxiv pre-prints. One is from the SFP facility and reports on the male littermates from this study. The other is from a conventional facility (same facility as the 2012 Mehran et al paper reports on).

      Hyper-variability in Circulating Insulin Levels and Physiological Outcomes to High Fat Feeding in Male Ins1-/-:Ins2+/- Mice in a Specific Pathogen-free Facility Nicole M Templeman, Arya Mehran, James Johnson bioRxiv doi: http://dx.doi.org/10.1101/031799

      Hyper-variability in Circulating Insulin and Physiological Outcomes in Male High Fat-fed Ins1-/-:Ins2+/- Mice in a Conventional Facility Arya Mehran, Nicole M Templeman, Xiaoke Hu, James Johnson


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    2. On 2016 Feb 28, Dave Bridges commented:

      A preprint was posted by this group describing similar experiments in male mice: http://dx.doi.org/http://dx.doi.org/10.1101/031799


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    1. On 2017 Jul 13, Randi Pechacek commented:

      Elisabeth Bik wrote a blog describing this paper on microBEnet in a discussion about human microbiomes at sea.


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    1. On 2016 May 25, André Morandini commented:

      I disagree with some points presented. A reply was submitted and not accepted. But published in Bulletin of Marine Science (http://dx.doi.org/10.5343/bms.2016.1018)

      Succession of generations is still the general paradigm for scyphozoan life cycles

      Abstract: A recent study proposed an unorthodox view of the long-known metagenetic life cycle of scyphozoan jellyfish. We argue that misinterpretations and imprecise information generated a misleading view of such life cycle patterns. In favor of our reasoning, we present the historical understanding of metagenesis, and contend that it can still be used as a shared general life cycle pattern for Scyphozoa, as well as for other medusozoans.


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    1. On 2015 Jul 15, thomas samaras commented:

      A number of findings indicate that lower birth weight and smaller body size are strongly related to low CHD.

      During the 20th C, Papua New Guinea was characterized by slow growth, low BMI and short height. Based on a 70-year tracking period no evidence of CHD or stroke was found among the natives. Many other indigenous populations show a similar relation between small size and the absence of CHD and stroke.

      A study by M. Eriksson (50-80 year old men) found a progressive increase in risk of heart attacks with increasing birth weight. The lowest birth weight quartile had the lowest risk (15% vs 25% for highest birth weight).

      Another study reported by Yajnik found that higher birth weight and better nourished urban Indians had 4 to 5 times the risk of CHD and diabetes as rural children that had lower birth weight and reduced nutrition. A WWII study of US twins found that lower birth weight identical twins had the highest life expectancy of 82 years. Higher birth weight fraternal twins had a life expectancy of 80.5 years. WWII singletons (highest birth weight) had a life expectancy of 78 years. The longer life expectancy indirectly points to lower CHD. Birth weight is strongly correlated with height, weight and BMI.

      Increasing BMI cannot be a driver for lower CHD because virtually all CHD risk factors get worse with increasing BMI starting from a BMI of less than 21. For example, HDL, APO A and sex hormone binding globulin decrease with increasing BMI. Blood pressure, cholesterol, TG, APO B, LDL also increase. Left ventricular mass and pulse wave velocity also increase with BMI, both independent CVD risk factors.


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    1. On 2015 Oct 04, Mohit Sharma commented:

      Intialmost and the most cancer specific Hallmark present universally in all malignant tumors


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    1. On 2016 Aug 18, David C. Norris commented:

      This JAMA Viewpoint hinges on a categorical claim: “probability is not meaningful in an individual context.” In a subsequent exchange with Van Calster, Steyerberg and Harrell<sup>1</sup> , the authors have backed away slightly from this precipice, stating that it was rather the verifiability (and not meaningfulness) of ‘individual probability’ that was at issue—and indeed that only a frequentist probability notion was targeted by this statement.<sup>2</sup> The authors also explain that their original citation of Cohen<sup>3</sup> in the context of this statement was meant “to direct the reader to the excellent discussion by Cohen of the limitations of the frequentist notion of probability”<sup>2</sup> . Cohen’s discussion is indeed excellent, and the reader who follows up this citation cannot fail to find a forceful rebuke of this Viewpoint's entire treatment of ‘probability’, delivered no less with particular reference to the very context under consideration—medical decision making:

      Nor is it open to a frequency theorist to claim that all important probabilities are indeed general, not singular. It often seems very important to be able to calculate the probability of success for your own child’s appendectomy... <sup>3(p49)</sup>

      Cohen proceeds from this observation to advance a Bayesian perspective; why Sniderman, D’Agostino and Pencina don’t do likewise would be a mystery if they did not reveal some peculiar methodological preoccupations in the ensuing development of their argument.

      Eschewing a (meaningful|verifiable) notion of ‘individual probability’, the authors substitute the petitio principii of ‘individual risk’—the continuous, probabilistic character of which they conceal through the conceit of “clinically meaningful risk categories” [emphasis mine]. Tellingly, they label these categories “clinically meaningful” because they have forfeited the philosophic basis for making them so. Ultimately, what makes any concept clinically meaningful is its openness to connection with the values and circumstances of individual patients. Classification schemes that prematurely close patients’ decision problems have precisely the opposite character. Without such artificial categories, however, the characteristically incoherent<sup>4</sup> frequentist approach to decision-making under uncertainty would lack even a semblance of that singular uncertainty which confronts the patient-physician dyad.

      The authors conclude by calling on physicians to mop up this shambles. They utter the shibboleth, “models cannot replace the physician,” then incant some vague magic by which physicians should restore the individual patient to a scheme that has excluded the individual from its very epistemology. Mathematically, the requisite magic translates to conditioning on individuals after frequentist methods have already averaged individuals out.<sup>4(pp61,509)</sup>

      The ‘art of medicine’ has long enough been defined by quixotic attacks upon mathematical impossibilities. Physicians of the future will gladly relinquish the merely computational tasks of medicine to predictive models and other forms of automation. They will rather find a purposive role in the creative, irreplaceably human endeavor of helping patients to formulate their medical decision problems in alignment with their values and circumstances,<sup>5</sup> and to decide these problems in accordance with appropriate evidence drawn from ever-improving<sup>6</sup> predictive models.

      1] Van Calster B, 2015

      2] Sniderman AD, 2015

      3] Cohen, L. Jonathan. An Introduction to the Philosophy of Induction and Probability. Oxford : New York: Clarendon Press; Oxford University Press, 1989.

      4] Robert, Christian P. The Bayesian Choice: From Decision-Theoretic Foundations to Computational Implementation. 2nd ed. Springer Texts in Statistics. New York: Springer, 2007.

      5] Moroff SV, 1983

      6] Mazzola E, 2015


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    1. On 2015 Jul 30, Marco Weiergräber commented:

      In their response Dibue-Adjei and Schneider state that they have decided to sample and analyze beyond the nominal sampling rate of the transmitter and state that this is done by other groups as well. To prove this two references (Raver SM et al., 2013 and Black SW et al., 2014) are mentioned. First, sampling beyond the nominal sampling rate is virtuell and does not generate real data points. According to the Nyquist-Shannon sampling theorem, frequency reconstruction beyond half of the nominal sampling rate of the transmitter, i.e. 125 Hz in this case, is not possible. The Nyquist-Shannon limit has been violated in Dibue et al. (2013) Second, the references given (Raver SM et al., Black SW et al., 2014) do not support the statement of Dibue-Adjei and Scheider in their response. Gamma is analyzed up to 60 and 80 Hz respectively in both references. With a transmitter bandwidth of 1-50Hz this could be tolerable. However, unlike in Dibue et al. (2013), the Nyquist-Shannon limit of 125 Hz has not been violated in both references. Indeed, a literature screen does not reveal any violation of the Nyquist-Shannon limit despite those published in Dibue et al. (2013, 2014) and Kamp et al. (2014).


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    1. On 2016 Apr 29, Leigh Jackson commented:

      The long and short of this review is that no good evidence could be found to show that acupuncture is effective for asthma in children.

      Two studies showing possible evidence of slight benefit were found.

      In one of these studies - Scheewe et al. - patients with bronchial asthma received drug therapy as well as traditional acupuncture. There was no sham control.

      In the other trial - Stockert et al. - patients with intermittent or mild asthma received probiotic drops as well as laser acupuncture. Each treatment had a placebo control.

      The evidence of benefit found in this review, such as it is, could conceivably be due to traditional or laser acupuncture or both; or to the other treatments or combinations of treatments; or in the case of Scheewe et al. simply to the placebo effect.

      On the basis of the evidence examined in this review, what is now needed is not large-scale RCTs, but successful independently replicated RCTs of the different forms of acupuncture versus sham controls alone.


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    1. On 2017 Dec 26, Evgeniy Gorbunov commented:

      Subetta is not homeopathic drug. We have already answered to E.V. Dueva to the similar comment regarding another drug produced using the same biotechnological platform (please see here: https://www.ncbi.nlm.nih.gov/pubmed/28036118).

      There are two references in Materials and Methods sections regarding Subetta manufacturing: to United States patent US8535664 (ref. 8), which E.V. Dueva mentioned in her comment; to the previously published work, where the drug preparation is briefly described (ref. 6).

      The study was performed blindly by independent laboratory using validated experimental approach. The article is fully transparent for the readers so they have an opportunity to familiarize themselves with these results and make their own opinion.

      The article passed peer-review process in accordance with the journal requirements. During the peer-review process, all necessary information had been provided including the images of blots.


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    2. On 2017 Dec 09, Evgenia V Dueva commented:

      Subetta is made from antibodies diluted beyond Avogadro’s limit (12 consecutive dilutions of 1:100, see Google patents US8535664) and thus contains no active molecules. The authors do not mention homeopathy in their article, but this clearly is a homeopathic drug.

      The results obtained by the authors are likely false positives considering the very low prior probability of a drug with no active molecules having any specific effect on insulin or any other receptors.

      The authors did not provide any images of their blots, or information on the protein concentrations that they used. Without this critical information, it is unclear how the article passed peer-review.


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    1. On 2015 Jul 08, David Keller commented:

      The CREST-2 investigators recognize that asymptomatic carotid stenosis should be screened for & get intensive medical treatment

      The CREST-2 clinical trial will study subjects having asymptomatic carotid stenosis, and will randomize them to receive invasive treatment (such as endarterectomy or stenting), or to receive no invasive treatment. All patients will receive the same background "intensive medical therapy" (1).

      The USPSTF recommends against screening for asymptomatic carotid stenosis for the purpose of treating it with intensive medical therapy, stating: "There is no evidence that identification of asymptomatic carotid artery stenosis leads to any benefit from adding or increasing medication doses (beyond current standard medical therapy for cardiovascular disease prevention)." (2) Yet, CREST-2 subjects will all be given intensive medical therapy, instead of the standard medical therapy which the USPSTF advises for them.

      Dr. Chaturvedi, CREST-2 corresponding author, stated their position very clearly in an email to me dated 7/8/2015: "You are correct that intensive medical therapy has never been tested against standard medical therapy. However, we felt that for clinical trial purposes, the "best" form of medical therapy should be tested."

      So, the CREST-2 subjects will be identified by screening, and will be treated with "intensive" medical therapy, despite the fact that USPSTF still recommends against screening for asymptomatic carotid stenosis, or treating it with anything stronger than "standard preventative" medical therapy. The CREST-2 investigators are ignoring these recommendations, as should all physicians.

      "Significant but asymptomatic atherosclerotic stenosis in any artery is an indication for intensive medical therapy", is a statement which has not been proved directly, but which has accumulated enough circumstantial evidence from the statin trials to have achieved the status of a clinical axiom. For example, the CREST-2 investigators were not willing to expose any of their patients with asymptomatic carotid stenosis to the risk of standard preventative medical therapy, despite the current dictum of the USPSTF (which is a mandate in many health systems). To deny screening for asymptomatic carotid stenosis, and to fail to treat it with intensive therapy when it is discovered, are not sensible or even ethical, given only minor extrapolation on the evidence we do have.

      It is time for the USPSTF to bring their recommendations into alignment with current best practices, as exemplified by the CREST-2 protocol.

      References:

      1: Chaturvedi S, Howard G, Meschia J. Carotid Endarterectomy for Asymptomatic Stenosis.JAMA Intern Med. 2015;175(7):1241-1242. doi:10.1001/jamainternmed.2015.1118.

      2: United States Preventative Services Task Force web site, accessed 7/7/2015. http://www.uspreventiveservicestaskforce.org/Page/Document/RecommendationStatementFinal/carotid-artery-stenosis-screening


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    1. On 2016 Aug 22, Vincent J Lynch commented:

      We have recently become aware of potential contamination in the Wooly Mammoth samples reported in this paper, M25 in particular (for details please see the preprint by Rogers and Slatkin available at https://arxiv.org/abs/1606.06336). While potential contamination of the M25 and M4 genomes with other Wooly Mammoth DNA may render these samples unusable for some analyses, we do not believe that the results or conclusions reported in Lynch et al. are adversely affected. Specifically our analyses focused on fixed, derived substitutions that occurred in the mammoth stem-lineage. The identification of mammoth-specific fixed, derived amino acid substitutions is unlikely to be affected by contamination of the M25 and M4 genomes with aDNA from other mammoths because these changes are by definition fixed in the genome of all mammoths.

      We have reanalyzed our data including the additional mammoth samples reported by Palkopoulou et al. (PMC4439331) and replicated all but 105 (91.3%) of the amino acid changes reported in Lynch et al., including the mammoth-specific TRPV3 substitution. Downstream enrichment analyses were also replicated. We are preparing a manuscript describing these reanalyses and will post a link to the preprint when it is available.


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    2. On 2016 Mar 16, Vincent J Lynch commented:

      Hi Mick,

      We may have been able to use the existing data if they were at high enough coverage and available prior to our sequencing of the Asian elephant genomes. But we were likely sequencing the genomes at the same time as Wilkie et al. (2013), thus they just would not have been available to use. We also sequenced each Asian elephant to ~30x whereas Wilkie et al. (2013) and Dastjerdi et al. (2014) sequenced to 5x and 2.5x (as you obviously know). The lower coverage may have made using the existing data less informative.

      Vinny


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    3. On 2016 Mar 10, Mick Watson commented:

      Hi Vinny

      Thanks for the reply. I guess my question would be whether you needed to generate new data on Asian elephant genomes, or could have just used existing data

      Cheers Mick


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    4. On 2015 Aug 05, Vincent J Lynch commented:

      Hi Mick,

      Although I was aware of this work, we didn't think it was appropriate to cite Dastjerdi et al. (2014) or Wilkie et al. (2013) because we did not use the data reported in these papers or even characterize the Asian elephant genomes we generated. Rather we just used the Asian elephant data we generated to polarize nucleotide changes in order to identify those that were mammoth-specific.

      Vinny


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    5. On 2015 Jul 09, Mick Watson commented:

      Quite surprised this paper didn't recognise previous efforts to sequence Asian elephant genomes:

      http://www.gigasciencejournal.com/content/3/1/12


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    1. On 2015 Nov 02, David Mage commented:

      This is an interesting article about SIDS and possible CNS involvement but the author seems to ignore two mandatory requirements for any such explanation: The first requirement is to account for SIDS unique left-censored 4-parameter lognormal age distribution that shows there is no ʺcritical age of vulnerability in SIDS" because the same equation fits all the SIDS age data from birth to well beyond one year. Schwartz (PMID: 3549041) correctly stated ʺAny viable hypothesis must account for its characteristic age distribution;" The second requirement is to account for the 50% excess male fraction of SIDS. It is not clear why the author now in 2015 fails to even mention male gender as a risk factor for SIDS as he correctly wrote in his 2008 EMBO Report (PMID: 18246101) that ʺ61% of SIDS cases occur in males," and he should have cited PMID: 5129415 that concluded ʺthe general disadvantage of males has long been recognized. The biologic differences must originate in the genetic differences between the sexes and those genetic differences are the consequence of disparity in the number of X-chromosomes." In addition U.S. linked birth and death certificate data (wonder.cdc.gov) show that the rate of ICD-10 R95 SIDS increases with live birth order, but infant deaths from CNS causes (ICD-10 P91.6 Hypoxic ischemic encephalopathy of newborn) do not, and furthermore, the ages of these CNS deaths are not lognormally distributed and they do not have the same 50% male excess as SIDS.


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    1. On 2015 Nov 05, David Attwell commented:

      Contractile pericytes should not be confused with smooth muscle cells. David Attwell, University College London, E-mail D.Attwell@ucl.ac.uk

      The original definition of pericytes by Zimmermann (1923) (translated into English here) included in this cell class the contractile cells on capillaries which Hill et al. (2015) (reviewed here) re-name in their paper to be smooth muscle cells (despite their clear morphological difference from classical arteriolar smooth muscle cells). Unfortunately, because Hill et al. re-named pericytes in this way, the title and text of their paper are misleading. Zimmermann (1923), and most workers since in the field of vascular biology, would define as pericytes the spatially-isolated contractile cells on capillaries that Hill et al. (2015) observe to control capillary blood flow in health and disease, confirming previous papers showing that pericytes have this role (Hall et al., 2014; Yemisci et al., 2009). Further discussion can be found in: Attwell, Mishra, Hall, O’Farrell & Dalkara (2015) What is a pericyte? J Cereb Blood Flow & Metab. advance online publication.


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    1. On 2015 Jul 27, Arnaud Chiolero MD PhD commented:

      This is a very insightful comment regarding the difficulties of pre-registration of protocols of analyses using observational study data


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    1. On 2016 Aug 24, M Mangan commented:

      After more than a year, with extensive back-and-forth with the journal and the authors, we were refused access to the data from this research.

      This is disappointing, of course. Although the journal did later make a statement to clarify some of the erroneous methods desciption (as a comment on the paper's site), they did not require fixes to the publication. "The reference to triplicates in the Methods section of the article refers to the sampling and not to the measurements."

      Further, in the correspondance, the authors admitted that they did not test for glufosinate--despite noting that they tested for the presence of crops with the resistance to this herbicide. So they cannot claim that their testing for herbicides was complete and claims of their detection of herbicides is flawed. If you ignore one of them, your claims of what is at the highest levels is of little value. Again, the journal did not require the authors to address this error.

      Statistical issues and flawed design should make the reader wary of the work within and the subsequent claims and conclusions.


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    2. On 2015 Oct 08, M Mangan commented:

      In apparent violation of PLOS policy, the authors of this paper refuse to provide the data underlying the claims for this work.

      This work has also been used in an attempt to influence regulatory policy from government agencies. However, citing many flaws of the work, including incomplete reporting of the data, regulators have dismissed the claims made.

      See: http://www.efsa.europa.eu/en/efsajournal/pub/4258


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    1. On 2015 Aug 07, Ivan Oransky commented:

      Here's a second look at this study by F. Perry Wilson of Yale: http://www.medpagetoday.com/Endocrinology/Obesity/52492


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    2. On 2015 Aug 01, DAVID ALLISON commented:

      Video Exaggerates Effects.

      In 1954, Huff [1] showed that representing data with 2D graphics of 3D objects could mislead if geometric principles were neglected. In the video accompanying this article [2] describing liraglutide weight loss results, at 1 minute, 26 seconds, a cartoon patient injects liragultide and shrinks in size. We measured an 11.4% reduction in depicted ‘waist diameter’. If waist perimeters approximate circles, this implies an approximately equivalent percent reduction in waist circumference (WC). Yet, the investigators report only a 7.3% reduction (not placebo corrected) in mean WC with liragultide. This alone indicates that the video exaggerates average change among treated patients. Further, a simplifying approximation of the human body as a cylinder of uniform mass [3] and empirical observations [4] suggest that weight scales to WC to the power of lambda, with lambda > 1. This implies that the 11.4% waist reduction shown portrays a figure with an implied weight reduction >11.4%. Yet, mean intervention body weight dropped only 7.9%.

      Concerns exist about misleading before and after photographs in weight loss advertisements [5]. Standards for weight loss drawings similarly need to avoid inadvertently misleading clinicians and patients.

      David B. Allison, University of Alabama at Birmingham

      Diana M. Thomas, Montclair State University

      Steven B. Heymsfield, Pennington Biomedical Research Center

      References

      1) Huff D. How to lie with statistics. New York: Norton; 1993.

      2) Pi-Sunyer X, Astrup A, Fujioka K, et al. A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management. N Engl J Med 2015;373:11-22.

      3) Heymsfield SB, Martin-Nguyen A, Fong TM, Gallagher D, Pietrobelli A. Body circumferences: clinical implications emerging from a new geometric model. Nutr Metab (Lond) 2008;5:24.

      4) Heymsfield SB, Heo M, Pietrobelli A. Are adult body circumferences associated with height? Relevance to normative ranges and circumferential indexes. Am J Clin Nutr 2011;93:302-7.

      5) Weight Loss Advertising: An Analysis of Current Trends: A Federal Trade Commission staff report. Federal Trade Commission: https://www.ftc.gov/reports/weight-loss-advertisingan-analysis-current-trends [accessed 8/1/15].


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    1. On 2015 Jul 06, Alexis Verger commented:

      If anyone is interested, our structural model of the ERM transactivation domain (TAD) in complex with MED25 is available in figshare as a Pymol session

      http://figshare.com/articles/MED25_interaction_site_with_the_TAD_of_ERM/1468391


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    1. On 2017 Jun 09, GERALD SMITH commented:

      In Ma et al. (1), we isolated Schizosaccharomyces pombe ctp1 point mutations, which we interpreted to separate genetically two known meiotic activities that depend on Ctp1 for meiotic DNA break repair. A later paper by Jensen and Russell (2) claimed these activities are not genetically separable. We believe the disparity in interpretation stems largely from the use of meiotic cells in our studies but mitotic cells by Jensen and Russell. We maintain that in meiotic cells the activities are genetically separable.

      During S. pombe meiosis, Rec12 (Spo11 homolog) makes DNA double-strand breaks (DSBs) and remains covalently linked to each 5’ end. The Mre11-Rad50-Nbs1 (MRN)-Ctp1 complex endonucleolytically removes Rec12 covalently linked to a short oligonucleotide (Rec12-oligo), an activity called “clipping.” The recessed 5’ end is then further digested, an activity called “resection,” to form a long 3’ single-stranded DNA tail that forms with intact DNA a joint DNA molecule to continue DSB repair. We concluded that most of the dozen ctp1 point mutants we studied retained nearly wild-type levels of resection but little clipping activity during meiosis. These conclusions were based on concordant genetic and physical analyses. Although we isolated these mutants based on a mitotic screen, we drew all of our conclusions from meiotic data.

      In our physical assays for clipping, we found in wild-type cell extracts abundant Rec12-oligos, which were absent or barely detectable in ctp1 mutant extracts, either point mutant or complete deletion (ctp1Δ). Failure to clip off Rec12 leaves irreparable DSBs and consequently inviable spores; the ctp1 point mutants had 10- to 30,000-fold, and ctp1Δ 100,000-fold, reductions of viable spore yields compared to wild type. These results indicate that the ctp1 mutants have strongly reduced clipping activity.

      To assay resection, we induced in meiotic cells a DSB at a well-defined site, using either the I-SceI or the I-PpoI homing endonuclease. Physical assays using Southern blots showed that resection of the DSB end proceeded as rapidly and extensively in the ctp1 point mutants as in wild type but slowly and to a much lesser extent in the ctp1Δ mutant. The homing endonucleases form DSBs without a covalently bound protein; I-SceI-dependent recombination thus requires resection but not clipping. In the ctp1 point mutants, the frequency of this recombination was equal to, or even twice as high as, that in ctp1+ cells, which was ~5 times higher than that in the ctp1Δ mutant. Thus, both physical and genetic assays indicate that resection is robust in the ctp1 point mutants.

      In interpreting these results, it is important to consider the role of Exonuclease I (ExoI), which could potentially resect DSB ends and produce recombinants. The MRN complex blocks ExoI access to DSBs in meiotic cells, but the Ku complex blocks ExoI in mitotic cells. Thus, ExoI plays no apparent role in DSB repair in meiotic cells with an intact MRN complex; instead, MRN promotes access of Ctp1 to DSB ends. For example, in meiotic cells exoIΔ has no significant effect on I-SceI-dependent recombination, but ctp1Δ reduces it by a factor of ~5 (3). Conversely, in rad50Δ mutants ctp1Δ has no significant effect, but exoIΔ reduces recombination by a factor of ~4. As expected, the ctp1Δ exoIΔ double mutant is like ctp1Δ in rad50+ cells but like exoIΔ in rad50Δ mutants.

      Jensen and Russell (2) assessed the mitotic activity of two of our ctp1 point mutants, along with ctp1+ and ctp1Δ, by analyzing the number and sizes of colonies formed on agar plates containing DNA damaging agents and spotted with 5-fold serial dilutions of cell cultures. Their results, like ours, showed that ctp1-6 and ctp1-25 are more DNA damage-resistant than the ctp1Δ mutant, indicating that the point mutants retain some activity. Removal of the Ku complex, by pku80Δ, suppressed these sensitivities but only if ExoI was present. Removal of ExoI enhanced the sensitivity to some agents (e.g., methyl methanesulfonate) but not, or only slightly, to others (e.g., ionizing radiation). In each of these various combinations, the point mutants were more resistant than the ctp1Δ mutant, confirming our results that the point mutants retain some activity. In nine out of ten cases, the ctp1-6 exoIΔ and ctp1-25 exoIΔ mutants were more resistant than ctp1Δ exoIΔ, which was completely sensitive to the agents tested. This result shows that the ctp1 point mutants retain an activity that can be supplied by ExoI, which we take to be resection.

      Jensen and Russell proposed that the ctp1 point mutations reduce, but do not abolish, a single activity. They further proposed that this residual activity is sufficient to repair a single DSB per cell (as in the I-SceI and I-PpoI experiments we reported) but not multiple DSBs per cell [as in the experiments with wild-type Rec12, which makes about 60 DSBs per meiotic cell (4)]. This proposal is hard to reconcile with our physical assays of clipping and resection noted above. It is not clear to us how a single Ctp1 activity could be altered, in either KM or kcat, to resect one DSB in a cell with wild-type kinetics but not clip Rec12 off 60 DSBs in a cell if resection and clipping result from the same activity, since both processes take about the same amount of time. Rather, we think the mutant proteins have greater reductions of clipping activity than of resection activity. Reduction of the number of Ctp1 molecules per cell, from 60 or more to about 1, could account for our results, but we consider this an unlikely explanation for the many mutants we studied. Instead, we think our mutants have retained nearly wild-type levels of resection but have strongly reduced levels of clipping, in meiotic cells. Whether the active sites for these two activities are in Ctp1, the MRN complex, or both is not addressed by our experiments. Without tests of a very large number of Ctp1 mutants under many conditions, we think the conclusion that the two activities are not genetically separable is unwarranted.

      Lijuan Ma, Neta Milman, Mridula Nambiar, and Gerald R. Smith

      References:

      1. Ma, L., Milman, N., Nambiar, M. and Smith, G.R. (2015) Two separable functions of Ctp1 in the early steps of meiotic DNA double-strand break repair. Nucleic Acids Res., 43, 7349-7359.

      2. Jensen, K.L. and Russell, P. (2016) Ctp1-dependent clipping and resection of DNA double-strand breaks by Mre11 endonuclease complex are not genetically separable. Nucleic Acids Res., 44, 8241-8249.

      3. Farah, J.A., Cromie, G.A. and Smith, G.R. (2009) Ctp1 and Exonuclease 1, alternative nucleases regulated by the MRN complex, are required for efficient meiotic DNA repair and recombination. Proc. Natl. Acad. Sci. USA, 106, 9356-9361.

      4. Fowler, K.R., Sasaki, M., Milman, N., Keeney, S. and Smith, G.R. (2014) Evolutionarily diverse determinants of meiotic DNA break and recombination landscapes across the genome. Genome Res., 24, 1650-1664.


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    1. On 2016 Mar 03, Liam McKeever commented:

      Ms. Allard,

      Thank you for your thoughtful comments. Using [tiab] would certainly increase the specificity of the search without much loss to sensitivity. The technique of this tutorial assumes that the article indexed for MEDLINE has been properly indexed, which will not always be a correct assumption. While I consider this assumption an acceptable and explainable loss in sensitivity in exchange for what is usually a considerable increase in specificity, the technique you are describing may actually be a perfect compromise.

      Sincerely,

      Liam McKeever,MS,RDN


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    2. On 2016 Feb 29, Rhonda J Allard commented:

      While I see the point you make about being sure your search strategies take into account both Medline and non-Medline articles, I don't believe you need to create two searches to accomplish this goal. The following search strategy (in my opinion), is as effective:

      fasting AND (alternate day* OR alternating day*) -- it retrieves 120 articles

      Notes: 1) The term fasting will map to Fasting [Mesh] and also search "fasting" in all fields. This will retrieve both Medline and non-Medline articles. 2) Anytime you use double quotes for phrase searching or the asterisk for truncation you are turning off the "Automatic Term Mapping" and searching all of PubMed.

      If the searcher is concerned with the amount of irrelevant articles they might retrieve when using keywords, another trick is to limit keywords to the title or abstract using [tiab], see below:

      military retrieves 127,746 results (it maps to Military Personnel[Mesh] and searches for "military" in All Fields) whereas (Military Personnel[MH] OR military[tiab]) retrieves 56,624 results. This second search limits the search results to where the topic is the military. The term military can appear in the Author Affiliation field or as part of another MeSH term.


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    3. On 2016 Feb 25, Liam McKeever commented:

      Mr. Bramer,

       Your point here is well taken but really represents a calculated shortcoming of that particular search, not the technique. The search in our paper was only designed to demonstrate the different aspects of the techniques in the paper. We kept it short on purpose for the publication. Obviously, in performing a review, a thorough analysis of any and all possible relevant MeSH terms must be considered. Generally, in practice, this technique becomes a somewhat iterative process where search results are checked against articles of known relevance. Early in the process, an article is often found missing from the list. Any article that does not show up in the list is analysed and the search strategy is revised. I then use a Boolean 'NOT' to subtract the search that has already been scanned by the reviewers from the new search. In this way, no one has to duplicate their efforts and the search parameters remain as tight as possible. Generally, the search process is continued right up to publication and adapts as necessary along the way. This is just a different way to go about the process. 
       As for your techniques having a 2-3% specificity. Do you realize that means only 2-3% of the citations irrelevant to your search are properly classified as such? Did you maybe mean to indicate a 97-98% specificity? If so, I do not see how you would manage a specificity that high without sacrificing sensitivity.If you have a citation that demonstrates the validity of a such a technique, I would be very interested to see it.
      

      Liam McKeever, MS, RDN


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    4. On 2016 Feb 25, Wichor Bramer commented:

      Dear Mr McKeever,

      Thank you for your detailed response to my remarks. Let me respond in return to some of your answers.

      2

      I was indeed referring that a thorough systematic review search ORs tiab terms with MeSH terms, not ANDs it as you do in your final search strategy. It depends on the goal of your research whether you focus on sensitivity of specificity. If you state you want to perform an exhaustive search strategy (such as is needed for systematic reviews), you should aim for sensitivity (without loosing too much specificity of course, but in the literature for SR searches a specificity of 2-3% is very normal). In your search strategy you will find relevant Medline articles on alternate day fasting only if they are also indexed with the MeSH terms you added. However you will miss important articles that have other relevant MeSH terms such as Varady KA, 2011, which has the MeSH terms Diet, Reducing, Weight Loss and Obesity/therapy. Hence you use MeSH terms to restrict your free text searches, which is not an improvement.

      4

      I was not objecting complicated searches in general, believe me, my SR searches are far more complicated than the one you show here (see for example: Malfliet A, 2015). However, I object unnecessary complicatedness that does not improve the search results. If I can get better results, only adding a few articles but not missing the above mentioned relevant article, by simply searching for:

      ("Alternate Day Fasting" OR "fasting on alternating days" OR "alternate-day fasting") NOT (animals[mh] NOT humans[mh])

      I don't understand why making it much more complicated with all these steps is a payoff in thoroughness, transparence and manipulability.

      Adding to that a new point of critique: are you aware that your search relies on automatic term mapping as well? If a search results page in PubMed says: Quoted phrase not found that means PubMed will try to do automatic term mapping. If you checked search details you would see that the phrase "fasting on alternating days" is reportedly not found, and replaced by

      (("fasting"[MeSH Terms] OR "fasting"[All Fields]) AND alternating[All Fields] AND days[All Fields])

      meaning that the user is not in control and the formula is neither robust nor reproducible nor transparent.

      Sincerely, Wichor Bramer

      Information specialist Erasmus MC (involved as search coordinator in hundreds of review per year)


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    5. On 2015 Nov 11, Liam McKeever commented:

      Mr. Bramer,

      Thank you for your critique of our work. We will respond to your comments in order in which they were written.

      1. Regarding the likelihood that someone would rely heavily on a "related citations" feature to perform a review, the initial impetus for writing the paper came from such comments from seasoned researchers indicating they rely heavily on this technique. After reading the paper, this is often the first point people argue. Obviously, I would not expect a librarian to rely on such inadequate techniques, but it is happening in the field and so we addressed it. Remember that there are many forms of review where the methods of review are not made explicit, such as in grant writing. Here, researchers are more likely to fall back on the methods with which they are most familiar. For that audience, these comments were appropriate.

      2. You state that there are robust search strategies which utilize both MeSH Terms and free text terms and that this has the added benefit of culling articles which may have been improperly categorized by the MEDLINE indexers. If you are referring to restricting (with Boolean AND) a MeSH search to only those folders which include certain text words in the [all fields], our strategy incorporates this. If you are instead describing duplicating your MEDLINE search by using free text words connected to the MeSH search with a Boolean OR, that is something entirely different.<br> It is true that re-searching the MEDLINE index with free text words opens the door to locating a possibly misplaced citation, but it comes with a steep cost. Let us define some terms. The sensitivity of search is the ability of that search to identify a truly relevant article. The specificity of a search is its ability to reject truly irrelevant articles. There is always a tradeoff between sensitivity and specificity. We would argue that a good search maximizes both sensitivity and specificity. The MEDLINE MeSH-term indexing method is both sensitive and highly specific. The reason for this that MEDLINE indexers read every article and catalog it according to the meaning of the article as opposed to a simple word count. To combine a MeSH-based search with a text-based version of the same search negates the entire purpose of having MEDLINE indexers. This would create a search that is highly sensitive but not very specific. Search strategies low in specificity may bypass the human error of the MEDLINE indexers, but possibly increase the human error of the scientists performing the review due to the unnecessary increase in volume of irrelevant citations.

      3. It is for this reason that we must separate the search between the MEDLINE and nonMEDLINE database. We use the robust MeSH search techniques to search the MEDLINE database and restrict the less robust “free text” based techniques to search only the ~10% of PubMed that has not been indexed for MEDLINE. This creates a search that is both sensitive and specific. Failing to separate the searches decreases the specificity of your search by increasing the percentage of irrelevant citations.

      4. You ask why this search needs to be so complicated. All searches are complicated. They only appear uncomplicated when you type in something simple and allow PubMed to do the thinking for you. The search on Alternate Day Fasting was chosen because it was simple enough to allow the reader to see the steps involved. Those steps are designed to put the control back in the hands of the user and refrain from relying too heavily on algorithms and automated term mapping. This requires some work up front, but the payoff is a thorough, reproducible formula that is transparent and easily manipulated as project needs change.

      Sincerely, Liam McKeever, MS, RDN


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    6. On 2015 Nov 10, Wichor Bramer commented:

      This article does not really give a good example of how to create search strategies. The title of the article states that it describes a method for exhaustive searches for literature reviews. I will discuss the contents of the article likewise.

      The solutions described here as common are not common practice in a sense that they are performed as described by researchers writing a systematic review. Hardly any researcher will think that related citations is the proper way to do an exhaustive search. Robust search strategies can be built in both medline and non-medline part of PubMed with one search strategy using both mesh terms and free text terms, which is very common practice among both researchers and information specialists. That way not only the most recent articles are retrieved by the free text terms, but also articles where MeSH terms are incorrectly assigned will be found.

      There is no need to limit the MEDLINE component to MeSH only searches, as text search might find extra relevant articles, nor is there a need to limit non-Medline part to text only searches, as this will not retrieve any articles, so no irrelevant articles as well.

      The ultimate search strategy presented here is very complicated:

      ((("Fasting"[MeSH] OR "Obesity/diet therapy"[MeSH] OR "Weight Loss/physiology"[Mesh]) AND "Humans"[MeSH]) AND ("alternate day fasting" OR "fasting on alternating days" OR "alternate-day fasting")) OR (("Alternate Day Fasting" OR "fasting on alternating days" OR "alternate-day fasting") NOT medline[sb])

      Why shoud it be so complicated? With this search articles on alternate day fasting are only retrieved if they also have one of the MeSH terms shown. Is that necessary? Each article found with this method has one of the phrases ("alternate day fasting" OR "fasting on alternating days" OR "alternate-day fasting") in the text. In that case one can just search for those phrases, and not much more. You don’t need 32 steps for that.

      That search is not systematic either, but the described method does not provide a step by step approach to create a systematic search. The authors should have consulted with an information specialist before writing an article on a topic like this.


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    7. On 2015 Aug 12, Liam McKeever commented:

      Dear Ms. Gluck,

      Thank you for your comments. Training in the use of multiple databases was not the point of this paper. This paper was written in response to a recognition that many of the methods researchers use to perform their systematic reviews are not in fact systematic. A systematic review is meant to bring scientific methods into the process of writing a review. This means the methods of the review must be reproducible. Currently, many reviews that attempt to be truly systematic employ only the MEDLINE database because of its organized system of medical subject headings. If they do this correctly, they can perform an exhaustive search of the MEDLINE database. Our paper provided a technique for taking this systematic approach into an exhaustive search of both the MEDLINE and the PubMed databases, leading to a master formula, which could then be picked apart and improved upon by the scientific community. The techniques translate well to other databases and have recently been translated to EMBASE.

      The argument that a complete systematic review should include an attempt to collect all relevant articles from multiple databases is well taken and commonly accepted. Preventing publication bias however is a much bigger picture than including multiple databases in a search strategy and was beyond the scope of this paper. To get all the null findings necessary to overcome publication bias would also mean including studies that either never entered or did not survive the peer review process. While such attempts should be made, a more achievable goal would be the thorough analysis of the publication bias present in a review where the search methodology is both explicit and reproducible.

      The selection of appropriate databases for a systematic review, as you implied, varies greatly by profession. It was therefore also not in the scope of this paper. I do think there is some value in considering what it actually means than not all databases contain all journals. I find it highly unlikely that a bio-medically relevant journal would not be indexed in MEDLINE simply because they neglected to apply. It is much more likely that they applied and were rejected. Just as a systematic review has inclusion criteria at the level of the articles selected, databases have inclusion criteria at the level of the journals selected for cataloging. The degree of research quality and scope of topic areas are considered and determined to either meet or not meet the standards of the database. When we select a database for a systematic review, we are defining our inclusion criteria at the level of the journal. With this in mind, assuming adequate search methods were used and provided a thorough analysis of publication bias has been performed, one could make the argument that a properly selected major database pairing, like MEDLINE and PubMed may be acceptable for a systematic review. From a scientific methods perspective, we feel what is most important is that the inclusion criteria at all levels are explicit and that is what this paper attempts to facilitate.

      Sincerely, Liam McKeever, MS, RDN


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    8. On 2015 Aug 06, Jeannine Gluck commented:

      The authors give the impression that an exhaustive and comprehensive search can be carried out in a single database. Not so. While PubMed/MEDLINE clearly covers a very large number of publications, no database is comprehensive. EMBASE, for one example, has better coverage of the European and pharmaceutical literature. There are many subject-specific databases, any one of which may be relevant for a search in a particular aspect of the health sciences. Researchers looking at educational or sociological aspects of their field would do well to consult resources in those disciplines.

      Workshops on systematic reviews emphasize, first and foremost, the requirement that multiple sources be consulted in order to minimize bias. This article was not about systematic reviews, per se. Still, any researchers calling their search "exhaustive" would do well to heed this advice. Had the authors included a librarian on their team, this serious oversight would not likely have happened.


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    1. On 2015 Dec 22, John Tucker commented:

      While addressing the important issue of commercial influence in the practice of medicine, the article's treatment of the issues surrounding "lifestyle drugs" relies too heavily on the values and stereotypes of the authors. Arguably, the most defining feature of "maladies" such as obesity, impotence, hair loss, and diminished libido is the wide range of importance attached to them by different people. The authors' failure to recognize that the values of others may differ from their own results in a paper that mostly misses the key issues in this controversial area.

      The shortcomings of this approach become apparent in a striking way in the article's introduction, in which three female authors, two of which are apparently under 40 years of age, pronounce impotence "a normal part of male aging". This view conflates "commonplace" with "unworthy of medical intervention", and if applied consistently would suggest that we should not develop drugs for the treatment of other diseases of aging such as arthritis and macular degeneration. It dismisses the desire of many older couples to maintain an active sex life, and appears rooted in stereotypes of what is appropriate behavior for older people.

      Likewise, the development of drugs that treat low sexual desire in women is criticized based on the argument that "there is no reliable evidence that hypoactive sexual desire disorder is a real medical condition". Unfortunately, the authors provide no definition for what constitutes "a real medical condition", and thereby dodge the central issue of what is an appropriate subject for pharmacological therapy. They simply appear to have decided that the concerns of women who are troubled by their lack of libido are invalid, and they "shouldn't worry about it". This is a remarkable value judgment to make on behalf of others.

      There are complex issues here, and they are worthy of address in greater depth than the intellectual shortcuts taken in this paper.


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    1. On 2015 Jul 20, David Keller commented:

      Why have these benefits not been reported by Parkinson disease patients taking these anti-malarials?

      I am skeptical about this report for the following reason: chloroquine is an old anti-malarial drug which must have been taken by many Parkinson's disease patients over the decades. If the benefits in humans are similar to those reported in the rat model, then surely it would have been observed and reported before. How do the authors explain this apparent contradiction?


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    1. On 2015 Sep 08, Alexandra Alexiev commented:

      This paper was featured in a microBEnet post here: http://microbe.net/2015/09/08/another-important-paper-microbiome-studies-strongly-influenced-by-sample-processing-and-pcr-primer/

      MicroBEnet is a blog that writes about microbiology of the built environment and is funded by the Sloan Foundation to do outreach and science communication.


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    1. On 2016 Jan 02, Mihaela Zavolan commented:

      Regulation of BAF170 seems to be a general property of miRNAs from the seed family of miR-302 and is also conserved between mouse and human:

      Gruber AJ, Grandy WA, Balwierz PJ, Dimitrova YA, Pachkov M, Ciaudo C, Nimwegen Ev, Zavolan M. Embryonic stem cell-specific microRNAs contribute to pluripotency by inhibiting regulators of multiple differentiation pathways. Nucleic Acids Res. 2014 Aug;42(14):9313-26. doi: 10.1093/nar/gku544. Epub 2014 Jul 16. PubMed PMID: 25030899; PubMed Central PMCID: PMC4132708.

      The same family of miRNAs also regulates DNA methylation:

      Sinkkonen L, Hugenschmidt T, Berninger P, Gaidatzis D, Mohn F, Artus-Revel CG, Zavolan M, Svoboda P, Filipowicz W. MicroRNAs control de novo DNA methylation through regulation of transcriptional repressors in mouse embryonic stem cells. Nat Struct Mol Biol. 2008 Mar;15(3):259-67. doi: 10.1038/nsmb.1391. Epub 2008 Mar 2. PubMed PMID: 18311153.

      Benetti R, Gonzalo S, Jaco I, Muñoz P, Gonzalez S, Schoeftner S, Murchison E, Andl T, Chen T, Klatt P, Li E, Serrano M, Millar S, Hannon G, Blasco MA. A mammalian microRNA cluster controls DNA methylation and telomere recombination via Rbl2-dependent regulation of DNA methyltransferases. Nat Struct Mol Biol. 2008 Mar;15(3):268-79. doi: 10.1038/nsmb.1399. Epub 2008 Mar 2. Erratum in: Nat Struct Mol Biol. 2008 Sep;15(9):998. PubMed PMID: 18311151; PubMed Central PMCID: PMC2990406.


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    1. On 2015 Nov 05, David Attwell commented:

      Contractile pericytes should not be confused with smooth muscle cells. David Attwell, University College London, E-mail D.Attwell@ucl.ac.uk

      The original definition of pericytes by Zimmermann (1923) (translated into English here) included in this cell class the contractile cells on capillaries which Hill et al. (2015) re-name in their paper to be smooth muscle cells (despite their clear morphological difference from classical arteriolar smooth muscle cells). Unfortunately, because Hill et al. re-named pericytes in this way, the title and text of their paper are misleading. Zimmermann (1923), and most workers since in the field of vascular biology, would define as pericytes the spatially-isolated contractile cells on capillaries that Hill et al. (2015) observe to control capillary blood flow in health and disease, confirming previous papers showing that pericytes have this role (Hall et al., 2014; Yemisci et al., 2009). Further discussion can be found in: Attwell, Mishra, Hall, O’Farrell & Dalkara (2015) What is a pericyte? J Cereb Blood Flow & Metab. advance online publication.


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    1. On 2015 Oct 05, S Sundar commented:

      ARV-7 dynamics and re-induction of hormone sensitivity by chemotherapy in Prostate cancer.

      This report by Antonarakis’s group regarding reversal of ARV-7 positivity by Taxane chemotherapy is likely to have a significant impact on the sequencing of various hormonal and chemotherapeutic agents .

      The two previous independent reports of re- induction of hormone sensitivity by chemotherapy could probably be explained by this mechanism whereby chemotherapy induces favourable changes for hormone therapy to be effective again after prior hormonal resistance[1][2].

      The previous reports of re-induction of hormone sensitivity by chemotherapy utilised Docetaxel monotherapy as well as Chlorambucil and Lomustine combination therapy. Hence it could be hypothesised that the reversal of ARV-7 dynamics and consequent re-induction of hormone sensitivity is a class effect of chemotherapy induced selection pressure. Exploitation of this phenomenon would significantly optimise the use of existing hormonal and chemotherapeutic agents in prostate cancer.

      References:

      1. Cox RA, Sundar S. Re-induction of hormone sensitivity to diethylstilboestrol in androgen refractory prostate cancer patients following chemotherapy. Br. J. Cancer 2008; 98(1):238–239.

      2. Shamash J, Davies A, Ansell W et al. A phase II study investigating the re-induction of endocrine sensitivity following chemotherapy in androgen-independent prostate cancer. Br. J. Cancer 2008; 98(1):22–24.


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    1. On 2016 Jan 25, Jacob H. Hanna commented:

      Thank you for the valuable information.

      We highlight that the gene expression data in Chd4 null embryos presented in this paper, and the immuno-staining for Oct4/Nanog on Mbd3 null embryos in Kaji et al. Development 2007 <PMID 17287250>, both show formation of hallmarks of pluripotency in vivo at the pre-implantation epiblast ( http://imgur.com/lsM6kbV ). This is in contrast to Nanog null embryos for example, that cannot sustain Oct4+ cells at E3.5-E4.5 ICMs ( http://imgur.com/lsM6kbV ).

      As Mbd3 KO ESCs derivation in vitro is not compromised under optimized growth conditions (e.g. 2i/LIF (Rais et al. Nature 2013), KSR/LIF or high quality FBS/LIF conditions), we will be also testing Chd4 KO ESC derivation from null mice to finalize the discussion and provide a more complete and solid answer.


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    2. On 2016 Jan 25, Brian Hendrich commented:

      This paper is about the function of Chd4 in cells of preimplantation stage embryos. It is not about ES cells. Anyone wishing to attempt derivation of Chd4-null ES cells can obtain our Chd4 floxed mouse line which has been deposited with MRC Harwell (http://www.har.mrc.ac.uk/) for distribution.


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    3. On 2016 Jan 23, Jacob H. Hanna commented:

      I would first like to congratulate the authors on this elegant and important paper. The Hendrich group has previously purported in Kaji et al. Development 2007 paper that it is absolutely impossible to derive Mbd3-/- ESCs from Mbd3 null E3.5 embryos. This result was surprising considering that the authors show in the same paper presence of Oct4+/Nanog+ cells in Mbd3-/- ICMs. Further, Mbd3-/- ESCs are "hyper-naive" and resist differentiation even in the absence of LIF (Kaji et al. Nature Cell Biology 2006, Reynolds et al. Cell Stem Cell 2012). Our group has revisited this result in Rais et al. Nature 2013, and was able to efficiently derive Mbd3-/- ESCs in serum free enriched 2i/LIF conditions. This suggests that the main conclusion of Kaji et al. 2007 Development paper Kaji K, 2007 titled "Mbd3 is required for development of pluripotent cells", is invalid and constitutes an artifact possibly due to using a low quality fetal bovine serum (FBS) batch.

      In O'Shaughnessy-Kirwan et al. Development 2015 have generated Chd4 null mouse embryos and show that Oct4+/Nanog+ ICM is formed in vivo, just like in Mbd3-/- embryos Kaji K, 2007. This indicates again that Mbd3/Chd4/NuRD is dispensable for the formation of pluripotent cells in vivo. It is disappointing that the authors did not describe attempts to derive Chd4 knockout ESCs in this work and explain their ambiguous and controversial results on NuRD complex null ESC derivations Kaji K, 2007.

      Jacob (Yaqub) Hanna M.D. Ph.D.

      Department of Molecular Genetics

      Weizmann Institute of Science | 234 Herzl St, Rehovot 7610001, Israel

      Email: jacob.hanna@weizmann.ac.il

      Lab website: http://hannalabweb.weizmann.ac.il/

      Twitter: @Jacob_Hanna


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    1. On 2015 Jul 25, David Keller commented:

      Yet another treatment is proved futile for slowing neuro-degeneration

      Pioglitazone, meet minocycline, co-enzyme Q-10, creatine, and vitamin E. They are all losers in the search for a neuro-protective agent to slow the progression of diseases like Alzheimer's and Parkinson's.

      This result is particularly disappointing given the recent observational study which found the use of thiazolidinediones ("glitazones") to be associated with reduced incidence of Parkinson's disease [1].

      Note: pioglitazone is the only widely-used glitazone since the FDA restricted the use of rosiglitazone (Avandia) due to safety concerns.

      Reference:

      1: Brauer R, Bhaskaran K, Chaturvedi N, Dexter DT, Smeeth L, Douglas I. Glitazone Treatment and Incidence of Parkinson's Disease among People with Diabetes: A Retrospective Cohort Study. PLoS Med. 2015 Jul 21;12(7):e1001854. doi: 10.1371/journal.pmed.1001854. eCollection 2015 Jul. PubMed PMID: 26196151.


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    1. On 2015 Aug 06, Andrea Messori commented:

      Equivalence of sofosbuvir-ledipasvir (12 weeks) and ABT-450/ ritonavir/ ombitasvir/dasabuvir (12 weeks) in previously untreated patients with genotype 1 HCV infection

      By Andrea Messori, PharmD, Sabrina Trippoli, PharmD

      HTA Unit, Tuscany Region, ESTAR, Regional Health Service, 50100 Firenze, Italy

      Some debate is ongoing on which procurement methods can contribute to reduce the high prices of direct-acting antiviral agents (DAAs) indicated for the treatment of hepatitis C (1-4). Two techniques are particularly suitable for this purpose: a) price-volume agreements (3,4); and b) competitive tenders (1,2). In this brief report, we re-examine the results published by Trippoli et al. (5) to evaluate how these findings can be a suitable clinical basis for undertaking competitive tenders according to the current Italian regulation.

      At the end of 2012, a national regulation was issued in Italy (“decreto Balduzzi” [6,7]) concerning the acquisition tenders run by our NHS. According to this regulation, when these tenders are aimed at drugs that belong to the same pharmacological class, a preventive authorization must be obtained from our National Medicines Agency (Agenzia del Farmaco, AIFA) to certify that the agents under examination are therapeutically equivalent. Otherwise, these tenders can no longer be performed. Hence, defining equivalence is, in Italy, not only a matter of scientific interest but also a prerequisite for making procurement decisions within our NHS.

      In the field of DAAs, the main practical need for conducting tenders is to promote a competition between the two main combination treatments presently available: a) the combination of sofosbuvir and ledipasvir (manufactured by Gilead), abbreviation: SOF/LED; and: b) the four –drug combination manufactured by Abbvie (that includes ABT-450/ ritonavir/ ombitasvir/dasabuvir); abbreviation, ARIOD. To avoid an excessive heterogeneity in the clinical material included in this assessment, we restricted our analysis to the treatments based on a duration of 12 weeks and to the indication of previously untreated patients infected by genotype 1. The end-point was the achievement of sustained virologic response at 12 weeks after the end of therapy (SVR12). It can be seen that these criteria are similar to those employed by Trippoli et al. (5). As regards the margin of equivalence, we adopted the value of ±10% around the overall meta-analytical rate calculated for both treatments.

      By running a PubMed query, we searched for more recent studies not included in the meta-analysis of Trippoli et al., but we found none. Furthermore, since the present analysis was essentially based on a proportion meta-analysis design, we replaced the all-in-one Bayesian model adopted by Trippoli et al. with the more traditional random-effect frequentist model of proportion meta-analysis (software: Open Meta-Analyst, version 4.16.12, Tufts University).

      Overall, our proportion meta-analysis included 3 studies for SOF-LED and 3 studies for ARIOD (see Appendix 1 for details). Figure 1 shows the Forest plot with the trial-specific rates of SVR12 achievement and the meta-analytic rates estimated separately for SOF-LED and for ARIOD. The overall meta-analytic rate estimated for SOF-LED and ARIOD (6 studies) was 95.5%; hence, the equivalence margin was from 85.5% to 100%. Both SOF/LED (rate of SVR12 achievement, 97.1%; 95% CI of SVR12: 94.4% to 99.8%) and ARIOD (rate of SVR12 achievement, 93.1% ; 95% CI: 85.6% to 100%) satisfied our pre-specified criterion of equivalence. It should be noted that, while most equivalence analyses generally adopt 90%CIs, our analysis employed a more selective confidence interval of 95%.

      In conclusion, these results indicate that SOF-LED and ARIOD, given for 12 weeks, are therapeutically equivalent in treatment-naïve patients with genotype 1 infection; this conclusion, formally based on a meta-analysis, confirms the message of equivalence that several experts have reported in narrative terms (1). As regards safety, several recent reviews have examined this point (8-11) and none of them have suggested that there is any difference between these two combination treatments. Hence, this overall picture of the literature indicates that SOF-LED and ARIOD can be included in competitive tenders aimed at the procurement of treatments for patients with the characteristics mentioned above.

      References

      1. Wilensky G. A New Focus on Prescription Drug Spending. JAMA 2015;314(5):440-441.

      2. Brunetto MR, De Luca A, Messori A, Zignego AL. Reducing the price of new hepatitis C drugs in the Tuscany region of Italy. BMJ 2015;350:h3363 doi: 10.1136/bmj.h3363 (Published 24 June 2015), available at http://bmj.com/cgi/content/full/bmj.h3363?ijkey=xYS3zhzXoox8A8t&keytype=ref

      3. Messori A. Newest treatments for hepatitis C: how can we manage sustainability? Clin Infect Dis. 2015 Aug pii: civ667. [Epub ahead of print], prepint available at http://www.osservatorioinnovazione.net/papers/cid2015pricing.pdf

      4. Messori A. Managing the high cost of innovative drugs: anti-cancer agents vs direct-acting antivirals for hepatitis C (Comment posted 2 April 2015), Ann Intern Med 2015, available at http://annals.org/article.aspx?articleid=2212249#tab

      5. Trippoli S, Fadda V, Maratea D, Messori A. Bayesian network meta-analysis to evaluate interferon-free treatments in naïve patients with genotype 1 HCV infection. Eur J Gastroenterol Hepatol 2015 Aug;27(8):983-984

      6. Messori A, Fadda V, Maratea D, Gatto R, Trippoli S, De Rosa M, Marinai C. Intravenous proton pump inhibitors for stress ulcer prophylaxis in critically ill patients: determining statistical equivalence according to evidence-based methods. Int J Clin Pharmacol Ther. 2014 Oct;52(10):825-9.

      7. Messori A, Fadda V, Gatto R, Maratea D, Trippoli S. Differentiating between “no proof of difference” and “proof of no difference” for new oral anticoagulants. BMJ. 2014; 348: g1955.

      8. Kohli A, Shaffer A, Sherman A, Kottilil S. Treatment of hepatitis C: a systematic review. JAMA. 2014 Aug 13;312(6):631-40.

      9. Feeney ER, Chung RT. Antiviral treatment of hepatitis C. BMJ. 2014 Jul 348:g3308.

      10. Pawlotsky JM. New hepatitis C therapies: the toolbox, strategies, and challenges. Gastroenterology. 2014 May;146(5):1176-92.

      11. Ferenci P, Kozbial K, Mandorfer M, Hofer H. HCV targeting of patients with cirrhosis. J Hepatol. 2015 Jun 19. pii: S0168-8278(15)00393-1. doi:10.1016/j.jhep.2015.06.003. [Epub ahead of print]

      APPENDIX 1. INFORMATION ON THE TRIALS INCLUDED IN THE PROPORTION META-ANALYSIS.§

      AUTHOR SVR12 (n/N) RATE (95% CI) TREATMENT


      Kowdley, 206/216, rate=0.954 (0.926 to 0.982), SOF-LED

      LONESTAR, 18/19, rate=0.947 (0.847 to 1.048), SOF-LED

      Afdal, 211/214, rate=0.986 (0.970 to 1.002), SOF-LED

      Kowdley, 70/79, rate=0.886 (0.816 to 0.956), ARIOD

      Pearl-IV, 185/205, rate=0.902 (0.862 to 0.943), ARIOD

      Pearl-III, 207/209, rate=0.990 (0.977 to 1.004), ARIOD


      §The complete bibliographic details of the studies are available from the paper by Trippoli et al. (5). Abbreviations: SOF/LED, sofosbuvir+ledipasvir; ARIOD, ABT-450/ ritonavir/ ombitasvir/dasabuvir; CI, confidence interval.

      FIGURE 1. PROPORTION META-ANALYSIS BASED ON A RANDOM-EFFECT MODEL

      Rates of SVR12 achievement with sofosbuvir+ledipasvir (12 weeks; 3 studies) and with ABT-450/ ritonavir/ ombitasvir/dasabuvir (12 weeks; 3 studies). The parameter I<sup>2</sup> is an index of heterogeneity. The Forest plot of this figure is available at http://www.osservatorioinnovazione.net/papers/trippoli-reanalysis.jpg . Abbreviations: SOF/LED, sofosbuvir+ledipasvir; ARIOD, ABT-450/ ritonavir/ ombitasvir/dasabuvir; C.I., confidence interval.


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    1. On 2015 Nov 18, Chris Del Mar commented:

      Between 1 - 5/1,000 children aged <5 years in developed countries may need hospital admission each year because of influenza infections, (PMID: 26111238) -- much lower (e.g. 0.6/1,000 children when based on laboratory confirmation of influenza, (http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19365). The benefits of influenza vaccination in children are a NNTB of 28 to prevent one child age aged >6 years getting influenza, but there is no effect on any downstream consequences such as secondary infections, nor benefit for children aged <2 years, from a Cochrane review (PMID 22895945). This systematic review estimates a rate of fevers of 6-7%, and of febrile convulsions at ~1/1,000 from inactivated vaccine fever in children aged >6 years (NNTH of 16 and 1,000 respectively) -- in the same range as those who might be prevented from a post-influenza admission. This suggests the decision about influenza vaccination needs discussion with parents to balance benefits against harms, perhaps using shared decision making (patient decision aid might be ideal), rather than public health pronouncements. Peter Collignon, Chris Del Mar


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    1. On 2016 Apr 13, Manoochehr Karami commented:

      Title: Death Suicide: Stop Saying "Completed Suicide"

      Authors: Manoochehr Karami(PhD)Social Determinants of Health Research Center and Department of Epidemiology, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran.

      Ali Ghaleiha(MD) Behavioral Disorders and Substance Abuse Research Center &Department of Psychiatry, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran

      The World Health Organization has considered suicide as a serious public health problem with more than 800000 deaths annually worldwide (1). Researchers use different terms including "Died by Suicide", "Committed Suicide" and "Completed Suicide" for attempted suicide leading to death (2-5). Among these, completed suicide is the most popular term, especially during the recent years. Although "Completed Suicide" is more accurate to indicate outcome of attempted suicide, "Death Suicide" is an alternative term without second thought to replace "Completed Suicide". In conclusion, authors, journal editors and readers are advised to consider "Death Suicide" to avoid ambiguity and misclassification of suicide cases.

      References:

      1. World Health Organization. Suicide Fact sheet N°398 2015 [cited 2015 August]. Available from: http://who.int/mediacentre/factsheets/fs398/en/.

      2. Khazaei S, Karami M, Sohailzade M, Sohrabnegad A. Determinants of complete suicide: A cross sectional study. Journal of Ilam University of Medical Sciences. 2013;21(6):240-7.

      3. Pallaskorpi SK, Isometsa ET, Henriksson MM, Suominen KH, Lonnqvist JK. Completed suicide among subjects receiving psychotherapy. Psychotherapy and Psychosomatics. 2005;74(6):388-91.

      4. Suominen K, Isometsa E, Suokas J, Haukka J, Achte K, Lonnqvist J. Completed suicide after a suicide attempt: A 37-year follow-up study. American Journal of Psychiatry. 2004;161(3):562-3.

      5. Wu A, Wang JY, Jia CX. Religion and Completed Suicide: a Meta-Analysis. Plos One. 2015;10(6).


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    1. On 2016 May 23, Stanton A Glantz commented:

      In June 2015 we published our paper “The smoking population in the USA and EU is softening not hardening” in the journal Tobacco Control. We showed that as smoking prevalence has declined over time, quit attempts increased in the USA and remained stable in Europe, US quit ratios increased (no data for EU), and consumption dropped in the USA and Europe. These results contradict the hardening hypothesis which is often used as part of the tobacco industry’s strategy to avoid meaningful regulation and protect its political agenda and markets, claiming that there is a need for harm reduction among those smokers who “cannot or will not quit.” Indeed, rather than “hardening” the remaining smoking population is “softening.”

      In February 2016 we received an email from Robert West, editor of the journal Addiction, informing us that Addiction was about to publish an article by Plurphanswat and Rodu entitled “A Critique of Kulik and Glantz: Is the smoking population in the US really softening?” whose sole purpose was to critique our Tobacco Control paper, and offered to let us respond to the criticism.

      The fact that Plurphanswat and Rodu sent their paper to Addiction was unusual because normal scientific procedure would have had them sending a letter to the editor of the journal that originally published the work (Tobacco Control).

      As detailed below, we did respond, noting that Plurphanswat and Rodu’s paper followed the well-established pattern of tobacco industry-funded researchers trying to create controversy about research inconsistent with industry interests, the fact that Rodu had understated his financial ties to the industry, and, of course, showing how their criticism was based on statistical error that they made.

      Addiction rejected our response because we would not delete the first two points and limit our response only to the statistical issue.

      This blog post includes the response that Addiction rejected so that readers of Plurphanswat and Rodu’s critique do not think we did not have a response. We also include a summary of our interactions with the journal and the related email correspondence.

      THE REJECTED RESPONSE

      Consider the Source

      “Harm reduction” is a key part of the tobacco industry’s strategy to avoid meaningful regulation and protect its political agenda and markets.[1] This agenda is premised on the existence of “hard core” smokers who “cannot or will not” quit.[2-4] Our paper, “The smoking population in the USA and EU is softening not hardening”,[5] undermined this agenda because it showed that, contrary to the hardening hypothesis, as smoking prevalence has declined over time, quit attempts increased in the USA and remained stable in Europe, US quit ratios increased (no data for EU), and consumption dropped in the USA and Europe.

      There is a longstanding pattern of tobacco industry-funded experts writing letters criticizing work that threatens the industry’s position, first described in 1993 by then-JAMA Deputy Editor Drummond Rennie.[6] Rodu and various co-authors have written several such letters.[7-10] Another similarity to past efforts is industry-linked experts submitting critiques of a paper published in one journal to another,[11-15] which is also the case here, with this critique of our paper published in Tobacco Control being published in Addiction. One would have expected any criticism to have been published as a letter in Tobacco Control.

      Addiction requires “full disclosure of potential conflicts of interest, including any fees, expenses, funding or other benefits received from any interested party or organisation connected with that party, whether or not connected with the letter or the article that is the subject of discussion.” As with another investigator supported by the tobacco industry,[16] the conflict of interest statement Plurphanswat and Rodu provide may not truly reflect the extent of Rodu’s involvement with the tobacco industry. For example:

      • Rodu’s Endowed Chair in Tobacco Harm Reduction Research at the University of Louisville is funded by the U.S. Smokeless Tobacco Company (US Tobacco) and Swedish Match North America, Inc.[17]

      • Rodu is a Senior Fellow at the Heartland Institute, which has received tobacco industry funding.[18-20]

      • Rodu is a Member and Contributor to the R Street Institute, which has received tobacco industry funding.[19,21]

      • Before moving to Louisville, Dr. Rodu was supported in part by an unrestricted gift from the United States Smokeless Tobacco Company to the Tobacco Research Fund of the University of Alabama at Birmingham.[8]

      • Rodu was a keynote speaker at the 2013 Tobacco Plus Expo International, a tobacco industry trade fair to discuss “How has the tobacco retail business evolved; where was it fifteen years ago, where is it today and where is it going”.[22]

      • Rodu has worked with RJ Reynolds executives between at least 2000 and 2009 to help promote industry positions on harm reduction, including specific products.[23-26]

      The substance of Plurphanswat and Rodu’s criticism is that the statistically significant negative association between smoking prevalence and quit attempts and the positive association between prevalence and cigarettes smoked per day both become non-significant when more tobacco control variables are included in the model (state fixed effects, cigarette excise taxes, workplace smoking bans and home smoking bans). The problem with including all these variables is that it results in a seriously overspecified model, which splits any actual effects between so many variables that all the results become nonsignificant. The regression diagnostic for this multicollinearity is the Variance Inflation Factor (VIF); values of the VIF above 4 indicate serious multicollinearity. For the United States, adding all the other variables increases the VIF for the effect of changes in smoking prevalence from 1.8 in our model for quit attempts to 16.7, and from 1.8 in our model to 17.9 for cigarettes per day, respectively. Plurphanswat and Rodu’s model is a textbook case of why one has to be careful not to put too many variables in a multiple regression.

      The Plurphanswat and Rodu criticism misrepresents our conclusions. We did not argue that drops in prevalence caused increased quit attempts and reduced consumption; we simply present the observation that, as prevalence falls, quit attempts increase and consumption fall or remain constant, which is the exact opposite of what the hardening hypothesis predicts.

      The references and the full email correspondence with Addiction is available at http://tobacco.ucsf.edu/addiction-refuses-allow-discussion-industry-ties-criticism-our-“softening-paper”


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    2. On 2016 May 19, Brad Rodu commented:

      We conducted an additional analysis of the American data used in this study, which has been published in Addiction: Plurphanswat N, 2016

      The original authors ran a linear regression of state-level measures of quit attempts, quit ratios and cigarette consumption on smoking prevalence using data sets from the Tobacco Use Supplements to the Current Population Surveys from 1992–2011. However, they did not include relevant tobacco control variables such as cigarette excise taxes, workplace and home smoking bans, and other unobserved, time-invariant, state-specific factors that could have accounted for the observed associations.

      We extended the original model by including these readily available variables, and we found that the original results were not robust; there was a large drop in the coefficients and they became statistically non-significant. These findings do not support the original authors' claim that the smoking population is "softening."

      Since 2005 Dr Rodu has been supported by the Kentucky Research Challenge Trust Fund and by unrestricted grants to the University of Louisville from tobacco manufacturers (Swedish Match AB, U.S. Smokeless Tobacco Company, Reynolds American Inc. Services, Altria Client Services, and British American Tobacco). Dr Plurphanswat has been supported by these grants since 2013.


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    1. On 2016 Nov 25, Leonid Schneider commented:

      Dr. Ana Pedro has published a critical post-publication peer review of this paper on my website. She highlights several technical inconsistencies of Melo et al 2015. https://forbetterscience.wordpress.com/2016/11/24/post-publication-peer-review-of-a-multimillion-dollar-heavy-nature-paper-by-ana-pedro


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    1. On 2016 Aug 23, Ben Goldacre commented:

      This trial has the wrong trial registry ID associated with it on PubMed: both in the XML on PubMed, and in the originating journal article. The ID given is NCT0082231. We believe the correct ID, which we have found by hand searching, is NCT00822315.

      This comment is being posted as part of the OpenTrials.net project<sup>[1]</sup> , an open database threading together all publicly accessible documents and data on each trial, globally. In the course of creating the database, and matching documents and data sources about trials from different locations, we have identified various anomalies in datasets such as PubMed, and in published papers. Alongside documenting the prevalence of problems, we are also attempting to correct these errors and anomalies wherever possible, by feeding back to the originators. We have corrected this data in the OpenTrials.net database; we hope that this trial’s text and metadata can also be corrected at source, in PubMed and in the accompanying paper.

      Many thanks,

      Jessica Fleminger, Ben Goldacre*

      [1] Goldacre, B., Gray, J., 2016. OpenTrials: towards a collaborative open database of all available information on all clinical trials. Trials 17. doi:10.1186/s13063-016-1290-8 PMID: 27056367

      * Dr Ben Goldacre BA MA MSc MBBS MRCPsych<br> Senior Clinical Research Fellow<br> ben.goldacre@phc.ox.ac.uk<br> www.ebmDataLab.net<br> Centre for Evidence Based Medicine<br> Department of Primary Care Health Sciences<br> University of Oxford<br> Radcliffe Observatory Quarter<br> Woodstock Road<br> Oxford OX2 6GG


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    1. On 2017 Aug 11, Alex Vasquez commented:

      The concern being addressed (after the documentation of human DNA, at least in fragmented form) is whether or not such “vaccine DNA” could be incorporated into the living “human DNA” of the host recipient; however, that is only one rather minor concern with the injection of human DNA from one person’s cells into the body of another living human being. From an immunology and inflammology standpoint, the concern is the likelihood that exogenous human DNA would trigger inflammatory responses after being perceived by the immune system and received by receptors for DAMPs (damage associated molecular patterns). Whether this amount of inflammation triggered from human DNA in vaccines is great or small, frequent or uncommon is unknown due to the lack of adequate vaccine testing; however, one would expect it to be of greater consequence in “genetically susceptible” persons and also when co-administered in various mixtures with other vaccines and with their pro-inflammatory ingredients such as aluminum (which exacerbates the release of human DNA[1]), mercury (known to promote immune sensitization) and allergenic antibiotics common in vaccines, including streptomycin[2], polymyxin B[3], neomycin[4], gentamicin and kanamycin[5].

      [1] "Although DNA DAMPs are closely associated with the development of autoimmune disease, DNA DAMPs also contribute to the activation of acquired immune responses following vaccination with alum adjuvant. Previous studies have shown that genomic DNA from dying cells induces the maturation of antigen-presenting cells as well as antigen-specific antibody and cytotoxic T cell responses. This suggests that self-DNA DAMPs can activate innate immune responses that induce acquired immunoresponses. Recently, Marichal et al. demonstrated that the adjuvanticity of alum was dependent on self-DNA released from cells at the alum inoculation site (Marichal et al., 2011). NLRP3 appears to be a key sensor in the induction of alum-mediated innate immunity, although its function is only partially dependent upon alum adjuvanticity. " Jounai et al. Recognition of damage-associated molecular patterns related to nucleic acids during inflammation and vaccination. Front Cell Infect Microbiol. 2013 Jan 8;2:168 [2] Romano et al. Anaphylaxis to streptomycin. Allergy. 2002 Nov;57(11):1087-8 [3] Henao MP, Ghaffari G. Anaphylaxis to polymyxin B-trimethoprim eye drops. Ann Allergy Asthma Immunol. 2016 Apr;116(4):372 [4] Goh CL. Anaphylaxis from topical neomycin and bacitracin. Australas J Dermatol. 1986 Dec;27(3):125-6 [5] Sánchez-Pérez et al. Allergic contact dermatitis from gentamicin in eyedrops, with cross-reactivity to kanamycin but not neomycin. Contact Dermatitis. 2001 Jan;44(1):54


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    2. On 2015 Jul 12, Kenneth Rochel de Camargo commented:

      One would expect that after the Wakefield debate editors would be doubly cautious before publishing something that hypothesises a link between vaccines and autism. Unfortunately, this article shows it is not the case. The argument is woven out of strenuous "just so" links, without adequate justification for any of the many steps required to make the purported connection; how those tiny base sequences were established to be of human origin? how to make sure that those were not simply integrated into the viral genome? how does such a small sequence of pairs would interfere with a host? has it really been demonstrated that such small sequences can somehow enter host cells? But even if we take those at face value, the fundamental premise of the whole argument, the supposedly "epidemiologic" evidence, is anything but. The "evidence" is a graph that plots the average incidence of autism in three countries and the average MMR coverage in those countries, with absolutely no attempt at any statistical correlation. Once again, even if we take such data for its face value, it is mind boggling that anyone would attempt to call this "evidence". Why those three countries were selected? Why was the US, where this problem is even more serious, left out? Why not test for correlation within each country? Why not test for correlation at all? Given the problems we already have with vaccine coverage in many places of the world, it is utterly irresponsible to publish something that weak and claim it to be evidence of anything.


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    1. On 2015 Jul 27, Janet Kern commented:

      The authors state, "Birth year changepoints were identified for 1980.9 [95% CI, 1978.6-1983.1], 1988.4 [95% CI, 1987.8-1989.0] and 1995.6 [95% CI, 1994.6-1996.6] for CA and U.S. data". For those that are knowledgeable about the Thimerosal issue, these are directly related to changes in the US vaccine schedule about Thimerosal. First for the 1981 date, in the late 1970s/early 1980s was when most states, including California adopted requirements that all children needed to be vaccinated to go to school and the expanded whole-cell DTP vaccine schedule (i.e., 5 doses vs. 3 doses). The whole-cell DTP vaccine contained 25 micrograms mercury per dose, so this first date corresponds to a significant increase in Thimerosal in vaccines in the US. For the second 1988 date, it corresponds to the approximate introduction of the Hib vaccine (first, with shots at 15-18 months, then followed very soon thereafter by the recommendation to be given as 4 shots starting at 2 months of age, and these generally contained 25 micrograms mercury per dose) and subsequently hepatitis B vaccine (3 shots starting on the day of birth, and these generally contained 12.5 micrograms mercury per dose) to be added to the US vaccine schedule. For the third 1996 date, it relates to what happened regarding the Hib vaccine. This vaccine started off as its own vaccine with 25 micrograms of mercury. Then in about 1992-1993, there was a combination vaccine that started to be marketed in the US whole-cell DTP-Hib vaccine, because this was a combined vaccine it contained 25 micrograms mercury. Then in about 1996, the acellular DTaP vaccine was recommended for administration to American infants, instead of the old whole-cell DTP vaccine. The acellular DTaP vaccine was generally manufactured without the Hib vaccine, so this resulted in American infants receiving increasing mercury dosing yet, again.

      It is possible to see the consequences of the above changes in Thimerosal content in US vaccines and the risk of autism in the following published peer-reviewed studies:

      (1) Young HA, Geier DA, Geier MR. Thimerosal exposure in infants and neurodevelopmental disorders: an assessment of computerized medical records in the Vaccine Safety Datalink. J Neurol Sci 2008;271:110-8. *** This study reveals a significant correlation between increasing/decreasing doses of mercury from Thimerosal-containing vaccines administered to birth cohorts in the United States from 1990 through 1996 and the increasing/decreasing prevalence of autism.

      (2) Geier DA, Kern JK, King PG, Sykes LK, Geier MR. A case-control study evaluating the relationship between Thimerosal-containing haemophilus influenzae type b vaccine administration and the risk for a pervasive developmental disorder diagnosis in the United States. Biol Trace Elem Res 2015;163:28-38.

      (3) Geier DA, Geier MR. An evaluation of the effects of Thimerosal on neurodevelopmental disorders reported following DTP and Hib vaccines in comparison to DTPH vaccine in the United States. J Toxicol Environ Health A 2006;69:1481-95. *** These studies reveal a significant correlation between the amount of Thimerosal children received from Thimerosal-containing Hib vaccines and the risk of autism.

      (4) Geier DA, Geier MR. A comparative evaluation of the effects of MMR immunization and mercury doses from Thimerosal-containing childhood vaccines on the population prevalence of autism. Med Sci Monit 2004;10:PI33-9. *** This study reveals a significant correlation between increasing/decreasing doses of mercury from Thimerosal-containing vaccines administered to birth cohorts in the 1980s and early/middle 1990s and the increasing/decreasing prevalence of autism.


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    1. On 2015 Jun 30, Remo Rohs commented:

      This entry refers to a conference presentation, and the original publication appeared in Nucleic Acids Res:

      GBshape: a genome browser database for DNA shape annotations. Chiu TP, Yang L, Zhou T, Main BJ, Parker SC, Nuzhdin SV, Tullius TD, Rohs R. Nucleic Acids Res. 2015 Jan;43(Database issue):D103-9. doi: 10.1093/nar/gku977. Epub 2014 Oct 17. PMID: 25326329 https://www.ncbi.nlm.nih.gov/pubmed/25326329


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    1. On 2015 Jun 30, Remo Rohs commented:

      This entry refers to a conference presentation, and the original publication appeared in Nucleic Acids Res:

      DNAproDB: an interactive tool for structural analysis of DNA-protein complexes. Sagendorf JM, Berman HM, Rohs R. Nucleic Acids Res. 2017 Jul;45(W1):W89-W97. doi: 10.1093/nar/gkx272. Epub 2017 Apr 20. PMID: 28431131 https://www.ncbi.nlm.nih.gov/pubmed/28431131


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    1. On 2015 Jun 30, Remo Rohs commented:

      This entry refers to a conference presentation, and the original publication appeared in Brief Funct Genomics:

      Evolving insights on how cytosine methylation affects protein-DNA binding. Dantas Machado AC, Zhou T, Rao S, Goel P, Rastogi C, Lazarovici A, Bussemaker HJ, Rohs R. Brief Funct Genomics. 2015 Jan;14(1):61-73. doi: 10.1093/bfgp/elu040. Epub 2014 Oct 14. PMID: 25319759 https://www.ncbi.nlm.nih.gov/pubmed/25319759


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    1. On 2015 Jun 30, Remo Rohs commented:

      This entry refers to a conference presentation, and the original publication appeared in Nucleic Acids Res:

      TFBSshape: a motif database for DNA shape features of transcription factor binding sites. Yang L, Zhou T, Dror I, Mathelier A, Wasserman WW, Gordân R, Rohs R. Nucleic Acids Res. 2014 Jan;42(Database issue):D148-55. doi: 10.1093/nar/gkt1087. Epub 2013 Nov 7. PMID: 24214955 https://www.ncbi.nlm.nih.gov/pubmed/24214955


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    1. On 2015 Jun 30, Remo Rohs commented:

      This entry refers to a conference presentation, and the original publication appeared in Proc Natl Acad Sci U S A:

      Quantitative modeling of transcription factor binding specificities using DNA shape. Zhou T, Shen N, Yang L, Abe N, Horton J, Mann RS, Bussemaker HJ, Gordân R, Rohs R. Proc Natl Acad Sci U S A. 2015 Apr 14;112(15):4654-9. doi: 10.1073/pnas.1422023112. Epub 2015 Mar 9. PMID: 25775564 https://www.ncbi.nlm.nih.gov/pubmed/25775564


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    1. On 2015 Nov 01, Anders von Heijne commented:

      These are important thoughts. So sad that the recent report from IOM: "Improving diagnosis in health care" that was published in september 2015 has excluded overdiagnosis from its analysis and the suggested remedies.


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    1. On 2015 Jul 23, Martine Crasnier-Mednansky commented:

      The present finding that Salmonella typhimurium transports fructoselysine via a mannose-type PTS (Enzyme IIA<sup>Gfr</sup>, IIB<sup>Gfr</sup>, IIC<sup>Gfr</sup> and IID<sup>Gfr</sup>), and uses fructoselysine as a nitrogen source when growing on glucose, deserves some scrutiny. The model established by Doucette CD, 2011 allows coordinated uptake of carbon and nitrogen via inhibition of Enzyme I by α-ketoglutarate, which accumulates in nitrogen limitation. This strategy when applied to the present finding indicates that, when growth occurs on glucose and fructoselysine, both glucose and fructoselysine PTS transports must be regulated to prevent conditions of nitrogen limitation, which will result in both PTS being inhibited. It was reported that the nitrogen PTS, PTS<sup>Ntr</sup> (Enzyme I<sup>Ntr</sup>, NPr, and Enzyme IIA<sup>Ntr</sup>), is activated by α-ketoglutarate (Lee CR, 2013). In this context, it is very tempting to propose that the PTS<sup>Ntr</sup> could function to regulate the transcription of the RpoN-dependent gfr operon. Thus, a controlled balance might occur for coordinating PTS-dependent carbon and nitrogen uptakes.


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    1. On 2017 Jan 15, John Tucker commented:

      Addendum:

      Performing a Monte Carlo calculation using actual PFS and OS data from P3 NSCLC trials in first-line, Stage IIIb /IV NSCLC patients and standard errors of measurement of 0.5 and 0.2 months for OS and PFS respectively, one can calculate that the maximum attainable measured correlation would be about 0.93. This number falls about halfway between my estimate of 0.85 and the 1.0 assumed in the paper.

      If one assumes that this maximum attainable value is representative of other cancers, and recategorizes the PFS-OS correlations accordingly, the fraction of correlations in the paper categorized as high or medium rises from 44% to 72%.

      So it appears that, as is so often the case, that the truth lies somewhere in the middle of the two positions argued here.


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    2. On 2017 Jan 15, John Tucker commented:

      Dr. Prasad is correct if one accepts that referencing a source which used the same proposed cutoffs, but which also failed to provide any justification for them, is sufficient validation.

      Looking at the math, however, it clearly doesn't make sense to expect a correlation coefficient of >0.85 when the OS values included in the analysis span a range of 7 months, and the individual OS values are measured with 95% confidence intervals that span 2 months.

      In the absence of a convincing rationale for the selection of the cutoff values, the conclusions of the paper represent little more than a tautology. The correlations are low because Prasad et al. have defined them as such.


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    3. On 2016 Dec 22, Vinay Prasad commented:

      Sadly, the reader is incorrect. We state clearly in the manuscript that the proposed cutoffs arise from ones proposed by the Institute of Quality and Efficiency in Health Care.


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    4. On 2016 Dec 07, John Tucker commented:

      Prasad and coworkers provide a review of previous meta analyses undertaken to determine the correlation of various surrogate endpoints with overall survival in cancer trials. They tabulate the various studies according to tumor type and provide their assessment in each case of whether the correlation found was high, medium or low. They conclude that most such studies found only low correlation with survival and that such surrogates should thus have no place in the approval of cancer therapeutics.

      Unfortunately, the authors provide no explanation for their chosen cutoffs of what represents a "high" (r > 0.85), "medium" (r = 0.7 to 0.85) or "low" correlation. This is a critical shortcoming, as the choice of these definitions dictates the paper's conclusions. Given the modest accuracy with which median PFS and OS values are determined in typically sized Phase 3 trials, these cutoffs are not mathematically justified.

      Looking at typical phase 3 trials in 1st line metastatic NSCLC, for example, overall survival typically ranges from 9 to 16 months with an accuracy of measurement (standard error) of about 0.5 months. Progression free survival is measured with a standard error of about 0.2 months. This suggests that even if the true correlation of PFS with OS in this indication were 1.00, the maximum observed correlation would be on the order of 0.85, which according to Prasad's criteria would only be a "medium" correlation. Because of the limited precision with which the values of PFS and OS are determined in clinical trials, the observed correlation will always be less than the true correlation, and Prasad's analysis fails to take this into account.

      In light of the unrealistic and mathematically unjustified categorization criteria used in this paper, it is not surprising to find that Prasad's characterization of the observed correlations often differs from that of the authors of the underlying studies. For example, Tang et al. characterize the relationship between PFS and OS in first line mCRC (r = 0.74) as "strong", but Prasad et al demote this surprisingly high correlation to "medium". Similarly, Petrelli et al characterize the correlation between OS and PFS in metastatic breast cancer as strong, but Prasad et al recharacterize the correlation (0.7) as "low".


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    1. On 2015 Jul 12, Miguel Lopez-Lazaro commented:

      The authors discuss that their results provide preclinical evidence proposing the use of SYK inhibitors in combination with paclitaxel in cancer patients, and that this combination warrants future clinical studies to assess its clinical benefit.

      Before initiating clinical studies, it would be interesting to evaluate if inhibition of STK can also potentiate paclitaxel-induced cytotoxicity in nonmalignant cells from a variety of tissues (including those responsible for the dose-limiting toxicity of paclitaxel). This is important because a drug combination that induces a potentiation effect in cancer cells will not be clinically useful if it induces a higher potentiation effect in nonmalignant cells. What matters is if the new treatment improves the selectivity of the standard treatment, and not if it improves its cytotoxic potency in cancer cells.

      It would also be interesting to test if the combination of a STK inhibitor + paclitaxel improves the survival rate induced by paclitaxel when tested under equivalent experimental conditions (e.g., equitoxic doses, determined in mice) in animal models representative of the patients who are expected to receive the new treatment (e.g., animal models of metastasis). Patients with localized and resectable tumors are usually treated successfully with surgery and are not expected to benefit from this pharmacological treatment.

      http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4381701/pdf/oncoscience-02-0091.pdf


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    1. On 2017 Jan 04, Stefan Hofmann commented:

      Retraction Notice: This article is retracted. The reason is as follows: It was brought to our attention that there were several significant errors in our published meta-analysis comparing the effect of intranasal oxytocin versus placebo administration on psychiatric symptoms. Correcting these errors changed the main result of this study. The corrected result is that oxytocin is not more efficacious for psychiatric symptoms compared to placebo. Our overall placebo-controlled effect size, which was previously reported as significant, is no longer significant. In addition, none of the symptom-specific effects of oxytocin versus placebo are significant. The primary error with our original data was the misspecification of the direction of several outcomes included in the meta-analysis. The reason for the error is that the program we used, Comprehensive Meta-Analysis, requires users to manually enter the direction of the effects. We mistakenly assumed that individuals in the placebo group would never show greater reductions in psychiatric symptoms than individuals receiving oxytocin. Therefore, we assumed that the direction of the placebo controlled effect size of oxytocin would never be negative. Although this is often true in placebo-controlled studies, this assumption was incorrect for 7 effect size estimates. In addition, we discovered some more minor data extraction errors. The corrected placebo-controlled effect size is Hedges' g=0.11, p=0.51. The direction of the effect size was also incorrect for 7 symptom measures (out of 28 total measures), which were used to calculate symptom-specific effects of oxytocin vs. placebo (e.g., on depression, anxiety, autism/repetitive behaviors, psychotic symptoms, and general psychopathology). The corrected effect sizes for the symptom domains are the following: depression (Hedges'g=-0.01, p=0.96), anxiety (Hedges' g=-0.04, p=0.86), autism/repetitive behaviors (Hedges' g=0.10, p=0.68), psychotic symptoms (Hedges' g=0.49, p=0.10), and general psychopathology (Hedges' g=0.15, p=0.47). Whereas our data previously indicated that oxytocin had some potential benefit for reducing depression, anxiety, psychotic symptoms, and general psychopathology, we now conclude that oxytocin has no benefit for any of these symptom domains. We greatly apologize to the journal, the reviewers, and readers for the errors in the original article, and we thank the readers who brought the errors to our attention (Donald Williams and Paul Bürkner). We would like to urge researchers to be mindful of the direction of the effect sizes, especially when using certain software programs, such as the Comprehensive Meta-Analysis program. Effect sizes and effect size directions should always be carefully examined manually, even when using a software program and it cannot be assumed that the placebo group is never superior to the treatment group.


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    1. On 2015 Dec 10, Marius Nicolae commented:

      Please note that the source code link should contain a tilde (~) before rajasek:

      http://engr.uconn.edu/~rajasek/lfqc-v1.1.zip

      Alternatively, the source code can also be found at:

      https://github.com/mariusmni/lfqc


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    1. On 2016 Mar 31, Johannes W. Dietrich commented:

      This interesting paper extends the concept of syndrome T, impaired quality of life in substituted hypothyoridism despite normal TSH concentrations, to children and young people. See Wiersinga WM, 2014 for a comprehensive review of previous research.


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    1. On 2015 Aug 06, Darko Lavrencic commented:

      This dispute looks like story "Blind men and an elephant": And so these men of Hindustan Disputed loud and long, Each in his own opinion Exceeding stiff and strong, Though each was partly in the right And all were in the wrong. ( https://en.wikipedia.org/wiki/Blind_men_and_an_elephant )


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    1. On 2015 Nov 27, Anders von Heijne commented:

      Please note the emerging evidence that GCA might be a form of chronic VZV-infection. TA biopsies show VZV in about 75% of cases. Treatment with aciclovir can be considered. See for example: Nagel MA et al JAMA Neurol. 2015 Nov 1;72(11):1281-7


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    1. On 2016 Aug 24, Ben Goldacre commented:

      This trial has the wrong trial registry ID associated with it on PubMed: both in the XML on PubMed, and in the originating journal article. The ID given is NCT0201433. We believe the correct ID, which we have found by hand searching, is NCT02014233.

      This comment is being posted as part of the OpenTrials.net project<sup>[1]</sup> , an open database threading together all publicly accessible documents and data on each trial, globally. In the course of creating the database, and matching documents and data sources about trials from different locations, we have identified various anomalies in datasets such as PubMed, and in published papers. Alongside documenting the prevalence of problems, we are also attempting to correct these errors and anomalies wherever possible, by feeding back to the originators. We have corrected this data in the OpenTrials.net database; we hope that this trial’s text and metadata can also be corrected at source, in PubMed and in the accompanying paper.

      Many thanks,

      Jessica Fleminger, Ben Goldacre*

      [1] Goldacre, B., Gray, J., 2016. OpenTrials: towards a collaborative open database of all available information on all clinical trials. Trials 17. doi:10.1186/s13063-016-1290-8 PMID: 27056367

      * Dr Ben Goldacre BA MA MSc MBBS MRCPsych<br> Senior Clinical Research Fellow<br> ben.goldacre@phc.ox.ac.uk<br> www.ebmDataLab.net<br> Centre for Evidence Based Medicine<br> Department of Primary Care Health Sciences<br> University of Oxford<br> Radcliffe Observatory Quarter<br> Woodstock Road<br> Oxford OX2 6GG


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    1. On 2015 Sep 22, DANIEL BARTH commented:

      Lack of appropriate controls leads to mistaking absence seizures for post-traumatic epilepsy

      Krista M. Rodgers<sup>1,</sup> F. Edward Dudek<sup>2,</sup> and Daniel S. Barth<sup>1</sup>

      <sup>1</sup> Department of Psychology and Neuroscience, University of Colorado, Boulder, CO 80309

      <sup>2</sup> Department of Neurosurgery, University of Utah School of Medicine, Salt Lake City, UT 84108

      We are disappointed in the rebuttal to our paper by D’Ambrosio and colleagues, which we believe does not productively address or clarify key issues. We decided that our response would be most useful to readers if we first describe here what prompted us to publish our paper; these issues are discussed briefly in a Letter to the Editor in the Journal of Neuroscience and also discussed in a detailed response hosted at http://arxiv.org/abs/1509.05802.

      Barth and Rodgers were funded from a DoD grant to use the fluid percussion injury (FPI) model to investigate interventional strategies for post-traumatic epilepsy (PTE). We used a different but well-documented FPI protocol (i.e., with a Picospritzer; (Frey et al., 2009; Rodgers et al., 2012, 2014). The FPI procedure provided macroscopic and histopathological evidence for brain injury that appeared similar if not identical to traditional FPI. We maximized severity so that with aggressive animal care we only had 10% mortality; however, greater severity enhanced mortality. Thus, we attempted to induce severe FPI and replicate the results of others, including the D’Ambrosio group.

      We were initially pleased to replicate nearly all of the data described by D’Ambrosio and colleagues. We recorded epileptiform electrographic events (EEEs), the hallmark of the short non-convulsive PTE “seizures” described by D’Ambrosio et al. (see Figs 2&7 from D’Ambrosio et al., 2009), with features nearly identical to many of the events shown in their publications, including spike-and-wave morphology, high frequency of occurrence, short duration, lack of frequency progression during the event, lack of post-ictal suppression, “spindle-like” amplitude fluctuation with longer events, and time-locked behavioral interruption (i.e., “freezing”) with accompanying facial automatisms. However, with randomization and blind procedures for our experimental and control groups (i.e., sham surgical and non-surgical controls), we became increasingly concerned that virtually every animal showed EEEs, even though some of the animals were obviously controls. Furthermore, in none of the animals could we find clear evidence of a focal onset to the EEEs; nearly all of the EEE onsets were synchronous on all electrodes. We realized that we were not recording FPI-induced epileptic seizures; instead, it appeared we had brief, absence-type seizures and/or other oscillatory activity.

      D’Ambrosio et al. argue that the SWDs we record in young adult (< 6 mo) rats are extremely rare and cast doubts on our methods for identifying SWD with supervised pattern recognition. Their statement is not an accurate reflection of the literature on SWD. While more difficult to identify due to their short (1-2 sec) duration, numerous authors in several papers have seen SWDs in young as well as adult rats. For example, Pearce et al. (2014), in Scharfman’s group, have reported that SWDs are present in 20% of young (2-3 months old) uninjured rats, a paper cited by the D’Ambrosio et al. rebuttal as evidence for their rarity in young animals. It is difficult to imagine quantifying brief SWD in the young animals with anything other than the supervised pattern recognition (support vector machine or SVM) we deployed. D’Ambrosio et al. suggest that the use of young rats with a low background SWD would simplify the task of identifying EEE. We strongly recommend the opposite. EEEs should be induced in older rats (> 6 mo) with abundant SWDs so that the two phenomena can be quantitatively compared, and compared to age-matched controls. This has never been done. Discriminating EEEs and SWDs in the same rats is essential if EEEs are to be validated as a model of PTE.

      In terms of identifying the seizures resulting from traumatic brain injury (i.e., PTE), D’Ambrosio and colleagues essentially claim that the properties of duration and waveform of the electrographic events are not clinically relevant, and consider that the critical feature is a focal onset. Clearly, the presence or lack of a focal onset is a meaningful part of the constellation of data needed to assess epileptic seizures, but the electrographic waveforms and their duration have been important criteria for decades to distinguish different types of seizures, particularly separation of absence seizures from complex partial seizures (i.e., more recently called focal dyscognitive seizures, Berg et al., 2010). The arguments by D’Ambrosio and colleagues (D’Ambrosio et al., 2009; D’Ambrosio and Miller, 2010) concerning what is clinically relevant are based on their own effort to re-define “What is a seizure?”; these are simply opinions by D’Ambrosio and colleagues not a formal consensus report from a group of unbiased experts (Dudek and Bertram, 2010). The argument of focal onset to distinguish EEEs does not reflect PTE in humans, which is not a focal variant of absence epilepsy, identical in every aspect to absence seizures except a focal versus generalized onset. For this reason we propose in our paper that EEE are not an etiologically realistic rat model of human PTE.

      In our interactions with Dudek throughout our experiments, we became familiar with the publications of Kevin Kelly (Kelly, 2004), who >10 years ago expressed concern about the EEE events of D’Ambrosio and colleagues, in large part because of Kelly’s own observations in control animals. Based on publications from Kelly et al, plus recent work from the Scharfman lab (Pearce et al., 2014), we decided that it was our scientific responsibility to publish our “negative” results, even though we fully anticipated that we would be criticized - if not ridiculed - by some researchers. We firmly believe that anyone considering use of the FPI model and EEEs, as described by D’Ambrosio and collaborators, should carefully read our paper and proceed with extreme caution. Their own description of the FPI method in their rebuttal strongly suggests that the traditional FPI device (and general procedures) is capricious and unreliable, even though other authors (Kharatishvili et al., 2006a, 2006b; Kharatishvili and Pitkanen, 2010; Shultz et al., 2013) besides D’Ambrosio and colleagues have reported genuine PTE.


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    2. On 2015 Sep 04, RAIMONDO D'AMBROSIO commented:

      We find that the authors' conclusions are invalidated by poor experimental design, application of inappropriate epilepsy diagnosis criteria, and disregard of antecedent literature that is incompatible with their thesis. These issues are addressed briefly in a Letter to the Editor in the Journal of Neuroscience, and thoroughly discussed in a document found at http://arxiv.org/abs/1509.01206

      First, there is no evidence that the authors managed to master the FPI technique to induce any epileptogenesis. They simply failed to induce any of the convulsive and non-convulsive epileptic seizures induced by classic FPI by many different independent laboratories. The discussion in ArXiv details why the nominal matching of the parameters of the pressure pulse used by the authors cannot be used to claim equivalency of injury.

      Second, the authors' report of frequent bilateral SWDs in virtually all male Sprague Dawley rats by 3 months of age is unprecedented and in conflict with all other reports we know of, which originate from many different independent laboratories. Thus, their claim that young male Sprague Dawley rats commonly exhibit SWDs is unfounded.

      Third, the authors do not use valid diagnostic criteria to distinguish focal epilepsy from absence epilepsy, but dwell instead on the morphology of the ECoG discharge which is not recognized as clinically valid to differentiate these seizure types. In the clinic, diagnosis of focal epilepsy is based on the identification of a pathological brain area from which seizures consistently precipitate (the epileptic focus) and the analysis of the consistent focality, lateralization and spread of the seizures. Using the clinically recognized criteria, it is apparent that the authors were dealing with absence epilepsy in both their control and FPI rats. The analysis in ArXiv details why the authors' diagnostic criteria are wrong, why they err in asserting that it is established that short duration and spectral power at 7-9Hz is uniquely characteristic of rodent absence epilepsy, and why the SWDs described here are clearly distinct from the focal seizures observed after effective FPI.

      Fourth, the study systematically fails to acknowledge published data that are inconsistent with their conclusion, including: 1) focal seizures induced by FPI are not sensitive to drugs (valproate and carisbamate) that potently control genetic SWDs, 2) FPI-induced focal seizures can be potently prevented by mild focal cooling of the perilesional neocortical epileptic focus, which proves both their acquired nature and their origin from an epileptic focus, and 3) spectral power in the theta band is common in acquired epilepsy in both rats and humans.

      As a result of these many flaws, this study simply amounts to a comparison of absence epilepsy in control rats with the same absence epilepsy in FPI rats. Contrary to the authors’ assertion, this study has no discernible implication for the translational relevance of the FPI model of PTE, or for any of the many other etiologically realistic acquired epilepsy models that are currently being used in a growing number of laboratories and that induce non-convulsive seizures with a dominant ECoG spectral power in the theta band.


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    1. On 2015 Oct 16, NephJC - Nephrology Journal Club commented:

      This study was discussed on Aug 25th and 26th in the open online nephrology journal club, #NephJC, on twitter. Introductory comments from Joel Topf and Suzanne Norby are available at the NephJC website and blog. The discussion was quite detailed, with more than 40 participants, including nephrologists, hematologists, fellows and residents. The highlights of the tweetchat were:

      • Dr Agarwal and his team, as well as the funding agency (NIDDK and the Indiana Institute for Medical Research) should be congratulated for designing and conducting this trial, though most participants were somewhat perplexed by the choice of outcome for this intervention.

      • There was a very intriguing signal in worse outcomes with intravenous iron (compared to oral iron) which, despite some uncertainty due to small sample size and early stoppage of the trial, is coherent with other non-renal data, as also some data from the dialysis literature, resulting in broad agreement that oral iron could be used more often, if needed.

      • Some bold questions were discussed: Is there any reason to treat anemia in chronic kidney disease unless hemoglobin was < 9 g/dL? Is there a role for regular monitoring of hemoglobin at all, given lack of data that iron or erythropoietin result in improvement of any meaningful outcome?

      A transcript and a curated (i.e. Storified) version of the tweetchat are available from the NephJC website.

      Interested individuals can track and join in the conversation by following @NephJC or #NephJC, or visit the webpage at NephJC.com.


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    1. On 2015 Oct 13, David M Patrick commented:

      I thank Dr. Kindlon for his comment. As he indicates, this study was not designed to be a comprehensive evaluation of POTS in this context. We used a simple clinical screening test rather than a lengthy evaluation. We also had a largely ambulatory patient grouping which will not represent the full spectrum of ME/CFS.


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    2. On 2015 Oct 05, Tom Kindlon commented:

      Is 1 minute of standing sufficient to test for orthostatic intolerance?

      Perhaps not a major point regarding the main thrust of the paper, but I thought I would highlight how orthostatic intolerance was tested:

      "Heart rate and blood pressure were measured lying and after 60 seconds of standing, with postural hypotension defined as a drop in systolic blood pressure by ≥20 mm Hg or in diastolic blood pressure by ≥10 mm Hg; postural tachycardia was defined as an increase from lying to standing heart rate of ≥30 beats per minute."

      I'm not an expert on dysautonomia and the like but my impression is that testing using 1 minute of standing is non-standard.


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    1. On 2016 Jun 16, Lanfranco Troncone commented:

      Adding to the discussion on the role of monoamines in violent aggression, this new data shed light on results we published many years ago on three models of aggression in REM sleep deprived rats. Aggression can be elicited in these animals by dopaminergic agonists like apomorphine, dopamine/noradrenaline precursor L-DOPA and noradrenaline synthesis inhibition by fusaric acid. We observed the clear differences in these three models and fusaric acid induced the more violent aggression while L-DOPA the most stereotyped mild boxing type. Our discussion proposed then that noradrenergic transmission was responsible for moderating the behavior while dopamine was triggering it. We offer the full paper at: Troncone LR, & Tufik, S. - Physiology & Behavior (1991), 50, 173-178 (PMID 1946713).


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    1. On 2015 Aug 31, Bill Cayley commented:

      From the fore-going discussion, it is clear that there remain questions about this approach, but it seems that this is an area where, at least in some cases, "less" may be "more". See also: https://lessismoreebm.wordpress.com/?s=appendicitis


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    2. On 2015 Aug 20, Paulina Salminen commented:

      In response to colleagues Bertele and Garattini, we agree that it is of great importance to evaluate the optimal treatment for uncomplicated acute appendicitis regarding all pros and cons for both surgery and antibiotic therapy. The aim of the APPAC trial was to test the hypothesis that uncomplicated acute appendicitis can be successfully treated with antibiotics by comparing antibiotic therapy with emergency open appendectomy. Even though more patient-centric outcomes are valuable, we aimed to identify a clear and concise definition of efficacy that would apply to both treatments in order to enable fair comparison – resolution of acute appendicitis. The non-inferiority approach was used as the goal was not to find an approach that is more effective than current standard treatment as appendectomy cures appendicitis. The non-inferiority approach allows us to evaluate other advantages and a novel treatment that is almost as effective as standard treatment might be preferred in practice or for some patients.(1)

      Based on our APPAC study results, we now know that the majority (73%) of patients with uncomplicated acute appendicitis were successfully treated with antibiotics.(2) We agree with Bertele and Garattini that major complications in both treatment arms are of vital importance. In the APPAC trial none of the patients treated initially with antibiotics and later with appendectomy had major complications; thus antibiotics are a safe first-line treatment for CT-proven uncomplicated acute appendicitis.

      The optimal use of antibiotic therapy regarding both spectrum and duration of the treatment in patients with uncomplicated acute appendicitis needs to be prospectively evaluated in large patient series including the important assessment of relevant patient-centric outcomes.

      1.Kaji AH, Lewis RJ. Noninferiority Trials: Is a New Treatment Almost as Effective as Another? Jama. 2015 Jun 16;313(23):2371-2. 2.Salminen P, Paajanen H, Rautio T, et al. Antibiotic Therapy vs Appendectomy for Treatment of Uncomplicated Acute Appendicitis: The APPAC Randomized Clinical Trial. Jama. 2015 Jun 16;313(23):2340-8.


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    3. On 2015 Jul 29, Vittorio Bertele' commented:

      The question of antibiotic therapy as an alternative to surgery for acute appendicitis keeps being addressed by a non-inferiority approach. We have previously challenged this attitude as it is not in the best interest of patients(1). The APPAC trial aimed to prove that fewer than one out of four patients with uncomplicated acute appendicitis would have required surgery within one year if they had been treated with antibiotics. The trial failed to prove this as the arbitrarily selected non-inferiority margin of antibiotics relative to surgery, although huge (24%), was not met. Still, the technically negative outcome of APPAC does not necessarily signify a failure(2). Avoiding surgery may be an advantage but patients also want to know what else could happen if they undergo, avoid or just defer appendicectomy. Unfortunately, the APPAC trial does not specify what patients can gain or lose with the two therapeutic strategies apart from the possibility of avoiding surgery in the antibiotic group. Besides –or even rather than– the greater than expected need for surgery in this group (27% instead of 24%), what matters most to patients is how many cases of peritonitis, other severe infections, complications of surgery, undue interventions, etc. there are in the two study arms. A trial addressing the superior overall benefit-risk profile of either the surgical or the antibiotic approach would have put these alternative strategies in a clearer perspective, enabling physicians and patients to make firmer decisions. A composite outcome measure including clinically relevant efficacy and safety endpoints –to address the sum of benefits and risks– would have answered the question whether failure to avoid surgery in spite of antibiotics still provides an actual advantage to patients, not just an acceptable disadvantage in exchange for unknown benefit. APPAC is one further demonstration that non-inferiority trials are often useless for patients(3): they assume an advantage (avoidance of surgery), allow too large a margin of failures –several patients needed surgery later in spite of the antibiotics– and, most important, do not address the possible overall benefit for patients (fewer complications?).

      Vittorio Bertele’ and Silvio Garattini IRCCS-Istituto di Ricerche Farmacologiche Mario Negri email: vittorio.bertele@marionegri.it, silvio.garattini@marionegri.it

      References 1. Banzi R, Torri V, Bertele V, Garattini S. Antibiotics versus surgery for appendicitis. Lancet 2011;378:1067-8. 2. Livingston E, Vons C. Treating Appendicitis Without Surgery. JAMA 2015;313:2327-8. 3. Garattini S, Bertele V. Non-inferiority trials are unethical because they disregard patients' interests. Lancet 2007;370:1875-7.


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    1. On 2017 Jul 24, Richard E Goodman commented:

      As one of the senior authors of the Siruguri et al., 2015 publication, with 20 years experience in evaluating the safety of Genetically Engineered (GE or GM) crops, I feel obligated to respond to the statements Dr. Sunil Verma is posting on PubMed COMMONS and now also in Science as an e-letter to the 2016 publication by Priyanka Pulls describing the development of this GE mustard. Dr. Verma's second comment posting here lists his letter in Science. Importantly, neither my comments, nor those of Verma are peer reviewed. We are giving our opinions (which differ markedly as does our experiences). I have written a response to Verma's e-letter in Science and it is available at http://science.sciencemag.org/content/352/6289/1043/tab-e-letters . It addresses the issues of the accepted hazard and risk evaluation of GE crops in India and internationally. Our 2015 publication here describes the assessment looking at the source of the genes, the sequences of proteins and the scientific rational is to evaluation potential risks for those who might be allergic to the protein (Barnase, Barstar or Bar), or to proteins that are highly identical, and could share IgE binding. Dr. Verma did not provide any data that demonstrates we are wrong, or that there are risks from this mustard. Instead in his supplemental information, he compared the sequence of Ani s 9, a minor allergen of a fish parasitic worm, to other sequences in the AllergenOnline.org database. And he implies that cross-reactivity might occur due to associated proteins like the SXP/RAL-2 proteins (Ani s 5 and Ani s 9). However, as noted by Garcia-Mayoral et al., 2014), similar proteins do not exist outside of worms (Nematodes). Ani s 9 has very little sequence similarity to Barnase, as described in our paper. Comparing Ani s 9 in AllergenOnline demonstrates that it is rather unique and unlikely to have cross-reactivity outside of the parasitic worm allergens. This mustard contains Barnase, not Ani s 9. Furthermore, he points to the six amino acid match of Barnase to Ani s 9. But as described in our paper and in my letter in Science, that six amino acid segment matches hundreds of proteins in the NCBI database, without any evidence of cross-reactivity or allergy. Furthermore, there is no evidence that a six amino acid match predicts cross-reactivity. The standard in CODEX is sequences matching >35% identity over 80 amino acids, and such matches are quite conservative (overpredict) both primary and confirmational epitopes (Goodman, 2006, Goodman et al., 2008). CODEX indicates you may do a short sequence match, but must justify the methods. If there are matches of >35% identity over 80, then serum IgE tests would be warranted using sera from at-risk (specifically allergic subjects (Goodman, 2008). In the future there will be improvements in the assessment (Goodman and Tetteh, 2011), however, Dr. Verma has not described any new method or any proof that he has an improvement. Instead, he has proposed hypothetical issues, a letter in Science and he has not posted the letter on facebook. If he thinks there can be improvements, he should do experiments and submit his results to a peer reviewed journal for scientific evaluation. The authors of the Siruguri et al 2015 paper stand by our results that this GM mustard is as safe as the non-GM mustards in use in India today.

      References: Garcia-Mayoral MF, Trevino MA et al., (2014). Relationships between IgE/IgG4 epitopes, structure and function in Anisakis simplex Ani s 5, a member of the SXP/RAL-2 protein family. PLOS, Negl Tropical Dis 8(3):e2735. Goodman RE. (2006) Practical and predictive bioinforamtics methods for the identiifcation of potentially cross-reactive protein matches. Mol Nutr Food Res 50:655-660. Goodman RE, Vieths S et al, (2008). Allergenicity assessment of genetically modified crops--what makes sense? Goodman RE. (2008) Performing IgE serum testing due to bioinformatics matches in the allergenicity assessment of GM crops. Food Chem Toxicol 46(Suppl 10):S24-S34. Goodman RE, Tetteh AO. (2011). Suggested improvements for the allergenicity assessment of genetically modified plants used in foods. Curr Allergy Asthma Rep 11(4):317-324.


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    2. On 2017 Jul 21, Sunil Verma commented:

      Reply to - Comment of Prof. Richard E. Goodman, and Vasanthi Siruguri 2017 Jul 19 2:50 p.m.

      Sunil Kumar Verma, Principal Scientist CSIR-Centre for Cellular and Molecular Biology, Hyderabad 500 007, India.

      Dear Authors,

      I read your elaborated reply with great enthusiasm and with hope to find specific answers to my very specific queries on this specific paper (PMID: 26079618). Instead of replying to my scientific observations on the methodology used in this paper, your reply focus more on defending the release of GM mustard in India, which is not really the central theme of this specific paper in question. The scope of this specific paper was limited to assess the allergenic potential of the transgene Bar, Barnase, and Barstar expressed in Genetically Modified Indian Mustard for heterosis breeding, wherein, the technical methodology which was used in this paper was questionable as specifically explained in my previous comment (supported by 15 pages of supplementary information, please see attachment in previous comment) in detail.

      Of course, GM Mustard release could be a consequence of this publication, which could be discussed in detail at appropriate forum when safety data and complete dossier which you have cited in your reply above is made available for public review by the concerned authorities (see ref. 1). Until that complete dossier is available for review, your justifications on GM mustard release would be one sided. And for that reason, I would not like to even touch upon the matter beyond the scope of this specific paper and my technical comments which are still unaddressed.

      With reference to your first argument that I have misinterpreted recommendations of Indian Council of Medical Research (ICMR, 2008) guidelines on the safety of Genetically Engineered (GE) crops, I would like to highlight that even the ICMR guideline also emphasize on overall structural similarities to predict the allergenic potentials (see page 13-14 in ref. 2), however, in the light of my previous comment and provided data therein, we now know that primary amino acid sequence comparisons are not the best known indicators of structural similarities among proteins, therefore my technical objection remains valid.

      My second technical comment was on Barnase-barstar complex and its possible differential immune response compared to individual proteins in free form; this aspect you have left unaddressed in your reply above.

      In response to my third technical objection, you have written that AllergenOnline.org database is a peer reviewed database. I understand that it is a peer-reviewed database; however, it's peer-reviewed status does not change the newly revealed fact that this database fails to detect the known allergen 'Ani s 9' (GenBank: ABV55106.1) as allergen using the strategy as was followed to examine the GM Mustard transgenes; thus, the conclusions drawn in this analysis remain erroneous.

      My commentary on your paper and flawed conclusion therein has been published in Science (3). Authors are welcome to take this debate further so that a consensus could be reached beyond a reasonable doubt on the conclusion of this specific paper in question and a suitable action could be taken to correct the conclusions of this paper by the way of erratum if appropriate, as an outcome of this post publication review.

      References:

      (1) Priyanka Pulla, India nears putting GM mustard on the table. Science 27 May 2016: Vol. 352, Issue 6289, pp. 1043. DOI: 10.1126/science.352.6289.1043

      (2) Guidelines for the Safety Assessment of Foods Derived from Genetically Engineered Plants. Indian Council of Medical Research. New Delhi. 2008. https://goo.gl/HuAnGC Link accessed on 22/07/2017

      (3) Sunil Kumar Verma, RE: Letter on In Depth "New India nears putting GM mustard on the table" Science 10 July 2017. http://science.sciencemag.org/content/352/6289/1043/tab-e-letters Link Accessed on 22/07/2017


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    3. On 2017 Jul 19, Richard E Goodman commented:

      Sunil Verma, CSIR Hyderabad, India, provided hypothetical comments about our study (PMID 26079618). He suggests our evaluation methods and conclusions were wrong and suggests our conclusions should be changed. We reviewed our publication and Verma’s comments. We conclude that he is misinterpreting the rationale for our study, the recommendations of the CODEX Alimentarius guidelines (2003/2009) and Indian Council of Medical Research (ICMR, 2008) on the safety of Genetically Engineered (GE) crops and our study. The dossier including study was reviewed and approved by the RCGM and GEAC committees of the government of India. Dr. Verma did not present data from studies of the GE plant or the proteins.

      Our response: 1) Indian mustard (Brassica juncea) is an important oil seed crop consumed as oil, seed and greens in India. However, production efficiency and plant diseases limits yield. Heterosis breeding often leads to production of agronomically superior hybrid plants.

      2) Mustard is usually self-pollinating. Therefore, scientists at the University of Delhi South Campus developed a GE Indian mustard system producing a male sterile plant and a fertility restorer line that allows hybrid production. The male sterile line was created by insertion of a gene that encodes an RNase (Barnase) that is expressed only in the tapetum (outer cell layer of the anther or pollen sac in early flower buds). The DNA construct includes a herbicide tolerant gene (bar). Expression of Barnase is tightly regulated by the construct of DNA as explained in Jagannath et al., 2002, where a long spacer DNA was inserted between the bar gene and promoter and the Barnase gene to ensure it is only expressed in the anther as demonstrated from field trial plants. Barnase is not detectable in seeds or green tissue of the plant (Jagannath et al., 2001). The fertility restoring line was developed by inserting a gene encoding Barstar also using an anther (tapetum) restricted promoter. Barstar binds to Barnase in a very tight protein complex that inhibits the RNase activity of Barnase (Bisht et al., 2004). The restorer line also includes the bar herbicide tolerance gene. Data on the two GE plants and their hybrid offspring were well characterized and data, including a full safety evaluation, was reviewed by the RCGM and GEAC committees of the Indian government with recommendations the plants are as safe as non-GE mustard.

      3) The safety evaluation followed the Indian Council of Medical Research guidelines (2008), which are consistent with the international guideline (CODEX Alimentarius, 2003 and 2009). One primary concern is whether the protein expressed by the novel genes encode allergens or proteins of moderate sequence identity (e.g. >35% identity over 80 amino acids) to an allergen so that allergenic cross-reactivity might be expected. The guidelines are referenced in the paper and are publically available. The methods and databases are cited. There is no evidence that proteins of lower sequence identity (including the FAO/WHO 2001 suggestion of 6 consecutive amino acid matches) are sufficient to demonstrate potential risks of allergy.

      4) The assessment for potential risks of allergenicity of GE crops have been extensively addressed (e.g. Goodman et al., 2008). The risks of food allergy recognized by food regulators around the world are that foods must be labeled with the source of ingredients so that people who have allergies to allergenic sources (e.g. peanuts, specific tree nuts, milk, wheat, eggs), can avoid ingesting foods that cause their allergies. Governments have adopted specific food labeling laws for all foods and hold producers accountable. The standard is the same for GE crops. When Pioneer Hibred was developing a nutritionally enhanced soybean by adding a gene from Brazil nut, Dr. Taylor at the University of Nebraska conduct tests since the gene was from an allergenic tree nut. The results demonstrated that the protein was an allergen that would put Brazil nut allergic subjects at risk (Nordlee et al., 1996) That GE plant never entered food production. There are no published scientific reports of a GE protein in an approved crop causing allergic reactions in humans.

      5) The methods suggested by Verma have not been demonstrates to predict allergenicity. A number of publications demonstrate that six-amino acid matches are common and not predictive (e.g., Hileman et al., 2002). Proteins with less than 50% overall identity are unlikely to be cross-reactive. Similar three-D shapes do not predict allergenicity. The AllergenOnline.org database is a peer reviewed database that includes Ani s 9, and there is no significant math. The database is updated every year and is accepted by international governments (Goodman et al., 2016).

      6) A similar GE mustard (canola) was produced PGS in Europe, now owned by Bayer CropScience. The canola include the same proteins, expressed in similar amounts and patterns. Seven events have been approved for production and consumption in Canada, the US, and Australia. Food and feed products from those events are approved for import and consumption in Japan, China, South Africa, Korea and the European Union. The food and feed safety evaluation summaries and details are available on the CERA-GMC.org/GmCropDatabase Result website. First approvals were in 1995 and there is no evidence of harm even though 95% of canola in North America is GE.

      7) The standard for food safety of GE crops in all countries that approve GE crops is that the GE plant does not pose any greater risk of allergy or toxicity than the similar non-GE crop. This GE Indian mustard developed at South Delhi campus meets those standards.

      We stand by our conclusions that the male-sterile and restorer Indian mustard events and progeny are as safe as the non-GM counter-parts. There is no data that suggests otherwise. Statements by Dr. Verma are hypothetical, not based on facts. This mustard meets the same standards used to evaluate GE crops approved in the US, Canada, Australia-New Zealand, Japan and other countries.

      Richard E. Goodman, and Vasanthi Siruguri

      References: 1.Siruguri V, Bharatraj DK, Vankudavath RN, Rao Mendu VV, Gupta V, Goodman RE. 2015. Evaluation of Bar, Barnase and Barstar recombinant proteins expressed in genetically engineered Brassica juncea (Indian mustard). For potential risks of food allergy using bioinformatics and literature searches. Food Chem Toxicol 83:93-102. 2.Jagannath A, Bandyopadhyay P, et al. 2001. The use of a spacer DNA fragment insulates the tissue-specific expression of a cytotoxic gene (barnase) and allows high-frequency generation of transgenic male sterile lines in Brassica juncea L. Mol Breeding. 8:11-23. 3.Jagannath A, Arumugam N, et al., 2002. Development of transgenic barstar lines and identification of a male sterile (barnase)/restorer (barstar) combination for heterosis breeding in Indian oilseed mustard (Brassica juncea).Curr Sci 82:46-52. 4.CODEX Alimentarius Guidelines 2003, 2009. 5.ICMR Guidelines. 2008. 6.Bisht NC, Jagannath A et al., 2004. A two gene-two promoter system for enhanced expression of a restorer gene (barstar) and development of improved fertility restorer lines for hybrid seed production in crop plants. Mol Breeding 14:129-144. 7.Hileman RE, Silvanovich A et al., 2002. Bioinformatic methods for allergenicity assessment using a comprehensive allergen database. Int Arch Allergy Immunol 128:280-291. 8.Goodman RE, Ebisawa M, et al. 2016. AllergenOnline: a peer-reviewed, curated allergen database to assess novel food proteins for potential cross-reactivity. Mol Nutr Food Res 60:1183-1198. 9.Nordlee JA, Taylor SL, Townsend JA, Thomas LA, Bush RK. 1996. Idnetification of a Brazil-nut allergen in transgenic soybeans. N Engl J Med. 334:688-692. 10.Goodman RE, Vieths S, et al. 2008. Allergenicity assessment of genetically modified crops—what makes sense? Nat Biotechnol 26:73-81.


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    4. On 2017 Jul 09, Sunil Verma commented:

      Comment on - Evaluation of Bar, Barnase, and Barstar recombinant proteins expressed in genetically engineered Brassica juncea (Indian mustard) for potential risks of food allergy using bioinformatics and literature searches

      Sunil Kumar Verma, Principal Scientist CSIR-Centre for Cellular and Molecular Biology, Hyderabad 500 007, India.

      In this study, the authors have tested the allergenic potential of the transgene Bar, Barnase, and Barstar expressed in Genetically Modified Indian Mustard for heterosis breeding. To this end, the authors have done the primary amino acid sequence comparisons of these proteins with the primary amino acid sequences of the known allergens listed in Allergenonline.org and NCBI Entrez protein database until January 2015 and 9 March 2015, respectively. Based on these bioinformatics comparisons authors concluded that the Bar, Barnase and Barstar proteins are unlikely to present any significant risk of food allergy to consumers. The authors also recommended not to perform any human serum IgE testing to further evaluate possible binding to the Bar, Barnase or Barstar proteins.

      I hereby propose that the above conclusions drawn by the authors in this study are incorrect and require a major revision.

      The main criteria used by the authors in these bioinformatics comparisons was the primary amino acid sequence homology searches of the proteins in question with that of the primary amino acid sequences of the potential allergen listed in above databases. All the hits with less than 50% primary amino acid sequence identities for full length proteins and less than 35% identity in the sliding window 80 amino acid segments of each proteins were ignored; the argument was that these matches could not have led to significant structural similarities among the proteins in question, therefore can be ignored.

      Several independent studies have shown that in many cases, even though the primary amino acid sequence similarity between two proteins / domains are very less (<20%), but the tertiary structures of the proteins may be highly similar. One classical example of this is high structural similarity between N terminal half of the Krit-B41 domain with that of the RA domain of RalGDS (1RAX:A) with an r.m.s. deviation of 2.9A for 80 aligned positions; despite a very low homology in their primary amino acid sequences (sequence identity =8.7%). [1, S1] It is notable that both RalGDS and Krit-1 interact with Rap1A through the RA and B41 domains, respectively [2, 3], and so the talin [4]. Thus, the high primary amino acid sequence similarity between two proteins may though infer greater chances of structural homology between these proteins; however, low primary amino acid sequence similarity does not necessarily infer that proteins in question will necessarily have higher structural dissimilarities.

      Since it is the conformationally determined structure of the proteins/epitopes which finally decide immunogenicity and allergenicity - and not just the primary amino acid sequences; the conclusion drawn in this study based on merely the primary amino acid sequence comparisons are scientifically inappropriate.

      Secondly, in real scenario, both the Barnase and Barstar proteins are expressed simultaneously and these two proteins remain in a complex and not as individual proteins in plant [5, 6]. It is not unlikely that structure of a specific protein in complex may be different than that of the structure of the same individual protein in free form. Also, there may be the possibilities of formation/exposure of new epitope(s) surfaces, particularly as we know now that there are several antibodies known that recognize just the native proteins and some may indeed require complex assembly.

      Thus, these conformationally determined epitopes that are recognized in the complex but not the free protein of interest may be reveled in differential screening between a protein and a complex form of the same protein. The conformationally determined epitopes could then be compared for structural homology with the epitopes in known allergens to determine the allergenic potential of two proteins in complex; such studies however, were not conducted in this paper; and the fact that Barnase and Barstar remain in complex and not in free form, was completely ignored throughout the study.

      Finally, I found that the overall implication of the Allergenonline.org database itself on correctly predicting the allergenic potential of a new antigen was also questionable.<br> To test this, I assumed that 'Ani s 9' (which is a very well known allergen from SXP/RAL-2 protein family) [7] is a new putative allergen and that this group of proteins are not yet listed in the database; and asked whether or not one can predict if 'Ani s 9' is a potential food allergen using the strategy as was used in this study for Barnase, Barstar and Bar transgenic proteins. The full length primary amino acid sequence comparison of 'Ani s 9' (GenBank: ABV55106.1) using default parameter i.e 'E' value cut off = 1 identified 7 hits (excluding the hits with its own sequences) with 'tropomyosin' allergen from various organisms and 'AAEL002761-PC ' allergen from Aedes aegypti, respectively; however, none of the hits was with significant similarity cut off (>50%). Thus, this bioinformatics search criteria wrongly predicted that the 'Ani s 9' is not a potential food allergen. [S2]

      The another criteria i.e. greater than 35% identity in the sliding window of 80 amino acid segment also did not produce any hit at all (other than self hits, which were excluded as explained above), indicating that this criteria also failed to identify 'Ani s 9' as potential food allergen. [S3] The third criteria i.e. 8 continuous amino acid segment search also did not identify any hit with any of the allergen in the database.[S4]

      Thus, the bioinformatics search as used in this study following any of the criteria defined could not identify 'Ani s 9' as a potential food allergen. This confirms that the criteria used in this study by authors could easily give false negative results.

      The only strategy that could have identified 'Ani s 9' as possible food allergen was a '6 continuous amino acid segment search, which could have identified its match with Allergen 'Lol p 5' for the 6-aa segment 'ANAPPA'. [S5]

      This criteria however, was not used in current study to predict the allergenic potential of Bar, Barnase and Barstar. If this specific criteria was used, Barnase transgenic protein also could have given a potential hit with Allergen Ber e 2 and Ani s 9 for the 6 continuous amino acid patch LFSTAA, and WVASKG, respectively [S6]; hence, the conclusion of this paper could have been different.

      In view of the above, I conclude that the criteria implemented in this study were not sufficient to exclude the possibility of the transgenic protein Bar, Barnase and Barstar being a possible allergen; therefore the conclusion drawn by authors that "the above transgenic proteins are unlikely to present any significant risk of food allergy to consumers" is not beyond a reasonable doubt, and hence need an appropriate correction by the way of erratum.

      Further, as discussed above, the Barnase and Barstar proteins are expressed simultaneously in final plant and they remain in a tight complex (i.e. barnase-barstar complex) and not as free form. The current study has not even touched upon the barnase-barstar complex; therefore, until the systematic studies on this complex is conducted and concluded, it is not appropriate to give a 'safe' tag to these transgenic proteins. This is particularly important since the conclusion drawn from this study was one of the major evidence which was used by the Indian regulatory authorities to recently give a safety clearance to the genetically engineered Brassica juncea (Indian Mustard) for commercial cultivation in India. [8, 9]

      Ref & Suppl Information


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    1. On 2015 Jul 23, Neil Davies commented:

      Østergaard and colleagues report that fewer people with a high genetic risk of high blood pressure develop Alzheimer disease compared to those with a lower genetic risk of high blood pressure (1). This is consistent with evidence that use of anti-hypertensive medication is associated with incidence and progression of Alzheimer disease (2–4). We investigated these associations in an observational longitudinal cohort study using data from the Clinical Practice Research Datalink, a database of anonymous UK National Health Service primary and secondary health care data. We found that patients prescribed angiotensin-receptor blockers were less likely to be diagnosed with Alzheimer disease (OR 0.47, 95% CI: 0.37 to 0.58) than those prescribed other anti-hypertensives. Our results were based on observational data and may suffer from residual confounding, but they provide suggestive evidence that blood pressure or blood pressure medication is implicated in the aetiology of Alzheimer disease. A meta-analysis of randomised controlled trials has also suggested that treatment with blood pressure lowering medication may help slow cognitive decline (5).

      However, there are alternative explanations for these associations. Although Mendelian randomization analyses may remove biases due to confounding and reverse causality, survival bias is still likely to be an issue. Individuals with a greater burden of high blood pressure SNPs may have higher mortality, which could cause them to die before developing Alzheimer’s disease and reduce the frequency of blood pressure increasing SNPs in cases compared to controls. Survival bias may also explain the apparent protective effect on Alzheimer’s disease risk of variants that are associated with heaviness of smoking. The smoking heaviness increasing allele located in the CHRNA5-A3-B4 gene cluster has been shown to be associated with increased mortality risk amongst ever smokers (6), which is likely to explain the reduced frequency of this allele amongst older populations of ever compared to never smokers.(7) This highlights the difficulties in using Mendelian randomisation for diseases of old age.

      The authors discuss survival bias, and conclude it is unlikely to be a problem. However, in our opinion more research is needed to quantify the extent and impact of survival bias in Mendelian randomisation studies. It may be possible to assess the extent of survival bias by comparing risk allele frequencies to known allele frequencies in younger populations, or to track their change in a population as it ages. Survival bias is likely to only occur if there are fewer risk alleles in older populations. Simulations may allow us to estimate the size of survival bias and aid the interpretation of Mendelian randomisation studies.

      Neil M. Davies, Amy E. Taylor, Marcus R. Munafò

      [1] S. D. Østergaard et al., Associations between Potentially Modifiable Risk Factors and Alzheimer Disease: A Mendelian Randomization Study. PLOS Med. 12, e1001841 (2015).

      [2] N. Li et al., Use of angiotensin receptor blockers and risk of dementia in a predominantly male population: prospective cohort analysis. Br. Med. J. 340, b5465 (2010).

      [3] N. M. Davies, P. G. Kehoe, Y. Ben-Shlomo, R. M. Martin, Associations of anti-hypertensive treatments with Alzheimer’s disease, vascular dementia, and other dementias. J. Alzheimers Dis. JAD. 26, 699–708 (2011).

      [4] P. G. Kehoe, N. M. Davies, R. M. Martin, Y. Ben-Shlomo, Associations of Angiotensin Targeting Antihypertensive Drugs with Mortality and Hospitalization in Primary Care Patients with Dementia. J. Alzheimers Dis. JAD. 33, 999–1008 (2013).

      [5] N. Levi Marpillat, I. Macquin-Mavier, A.-I. Tropeano, A.-C. Bachoud-Levi, P. Maison, Antihypertensive classes, cognitive decline and incidence of dementia: a network meta-analysis. J. Hypertens. 31, 1073–1082 (2013).

      [6] L. Rode, S. E. Bojesen, M. Weischer, B. G. Nordestgaard, High tobacco consumption is causally associated with increased all-cause mortality in a general population sample of 55,568 individuals, but not with short telomeres: a Mendelian randomization study. Int. J. Epidemiol. 43, 1473–1483 (2014).

      [7] A. E. Taylor, M. R. Munafò, CARTA consortium, Commentary: Does mortality from smoking have implications for future Mendelian randomization studies? Int. J. Epidemiol. 43, 1483–1486 (2014).


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    1. On 2016 Aug 24, Lily Chu commented:

      In response to public comments, Dr. Smith and her colleagues have conducted sensitivity analyses on the data, assessing the impact of CBT and GET on various outcomes when only subjects fitting Oxford criteria are considered versus when subjects fitting non-Oxford case definitions (i.e. 1994 Fukuda) are considered. They concluded in an Addendum to the original report that:

      "Our sensitivity analysis would result in a downgrading of our strength of evidence on several outcomes which can be attributed to the decrease in power, dominance of one large trial, or lack of trials using criteria other than the Oxford (Sharpe, 1991) case definition for inclusion. Blatantly missing from this body of literature are trials evaluating effectiveness of interventions in the treatment of individuals meeting case definitions for ME or ME/CFS."

      Almost all patients are diagnosed in the United States and most countries using the Fukuda criteria. The United Kingdom is the only region that uses the Oxford criteria on a regular basis. This means that clinicians need to be aware of low strength of evidence or the lack of evidence behind CBT and GET when considering this treatment for their ME/CFS patients.

      The full revised report may be read at: https://effectivehealthcare.ahrq.gov/ehc/products/586/2004/chronic-fatigue-report-160728.pdf


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    2. On 2016 Feb 12, Ellen M Goudsmit commented:

      Postscript 2016. The errors noted were rejected as inaccuracies by the editors and thus my comment (under Haney et al) was not published as a letter or correction. Example, they refused to accept that a trial discussed used two sets of criteria, not just the one listed. And if they had checked the reference given for the London criteria, they would have known that it does not give a list of authors. I was not named, so the citation is factually incorrect. I submit that this attitude to factual errors is inconsistent with good science.


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    3. On 2015 Jun 24, Ellen M Goudsmit commented:

      I've already noted some of the factual errors and misleading comments in this review online: http://annals.org/article.aspx?articleid=2322800

      Due to the word limit, I could not add that Haney et al named four individuals as authors of the London criteria for ME, despite the fact that their reference, the Westcare Report, did not [1]. The people listed in the review did not write the version published in the Westcare Report and this information has been in the public domain since 1994.

      I was also unable to point out that that Haney et al refer to clinical criteria (e.g., p. 834), when most of the case definitions they discussed were formulated for research.

      The omission of the new research criteria for classic ME is baffling as they have already been cited in the literature, most recently by Jason et al [2]. If people are going to make decisions about ME, or ME/CFS, they need to know what ME is. I suggest readers look online or access the original paper from 2009 [3].

      [1]. The UK Patient Organisations. “London Criteria”. In: Report from The National Task Force on Chronic Fatigue Syndrome (CFS), Post Viral Fatigue Syndrome (PVFS), Myalgic Encephalomyelitis (ME). Bristol: Westcare; 1994. Appendix B, Names, Definitions and Descriptions: p. 96-8. Available from: http://www.actionforme.org.uk/Resources/Action for ME/Documents/get-informed/national task force.pdf

      [2]. Jason, LA., Sunnquist, M., Brown, A and Reed, J. Defining essential features of myalgic encephalomyelitis and chronic fatigue syndrome. Journal of Human Behavior in the Social Environment, 2015, 25, 6, 657-674. Online 6th May. doi:10.1080/10911359.2015.1011256

      [3]. Goudsmit E, Shepherd C, Dancy CP, Howes S. ME: Chronic fatigue syndrome or a distinct clinical entity? Health Psychol Update. 2009;18(1):26-33. Available from: http://shop.bps.org.uk/publications/publications-by-subject/health/health-psychology-update-vol-18-no-1-2009.html

      Alternatively see: http://www.foodsmatter.com/me_and_cfs/cfs_me_causes_general/articles/goudsmit-me-clinical entity-10-12.html

      Revised article (2014): http://www.axfordsabode.org.uk/me/mecrit2014.htm


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    1. On 2015 Dec 02, Ellen M Goudsmit commented:

      Sad to note today that the journal chose to publish letters, favouring opinion above the correction of factual errors. How can science progress if editors collude in the perpetuation of inaccuracies and myths? Who will know that there ARE research criteria for ME as described by Ramsay? That there are helpful alternatives to CBT and GET?

      Postscript 2016. The editors decided not to publish the comment as a letter in the journal as they rejected the view that there were factual errors. Thus while I was not a co-author of the criteria cited in the article, and I'm not named in the reference given, listing me as a co-author is not a 'factual error' in their eyes. Nor is the claim that a trial I discussed selected patients using two sets of criteria, not just the one referred to in the article. In my view, this failure to correct errors and misleading information is inconsistent with good science.


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    2. On 2015 Jul 17, Ellen M Goudsmit commented:

      As someone who has studied myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS) since the 1980s, I appreciate the work completed by The National Institutes of Health Pathways to Prevention Workshops on what is now known as ME/CFS. Unfortunately, some of the information in the two reviews is inaccurate, incomplete and misleading (1,2). For example, in the report on diagnostic methods, the reviewers included the London criteria for ME but gave details in the table based on a version written by a layperson, rather than the four individuals cited in their reference (3). Moreover, they did not consider the updated criteria for ME (4), although one of the authors had emailed the panel on two separate occasions during the consultation phase to alert them to their existence.

      The second review (2) encourages further research on subgroups and outcomes other than fatigue and function but did not identify one of the few controlled studies which had employed such a design (5). For instance, in the Appendix, Table 1 lists the programme evaluated by Goudsmit and colleagues under ‘counseling and behavioural therapies’, and describes the treatment as ‘counseling’. It also states that patients were selected using the Oxford criteria, that the duration of follow-up was six months and that the outcomes were function and fatigue.

      In fact, the trial evaluated a physician-led multi-component programme comprising medical care, information on the illness, diet and relaxation, as well as advice on activity management and some counselling (5). It was conducted in the naturalistic setting of an NHS hospital clinic, patients were diagnosed using criteria for post-viral fatigue syndrome as well as the Oxford criteria, and data were available for a number of symptoms including cognitive impairment, as well as other variables. Fatigue improved as noted in the review but the latter did not convey that 82% of the patients rated themselves as ‘better’, that 23% were well enough to be discharged at six months and that the improvements were maintained at 1 year. Given the missing details, the study’s rating as ‘poor’ is understandable.

      The reviewers concluded that “more definitive studies comparing participants meeting different case definitions, including ME... are needed to fill research gaps”. It was therefore disappointing that they did not recognise the positive aspects of a study that used a different case definition and assessed a range of symptoms, not just fatigue.

      1. Haney E, Smith MEB, McDonagh M, Pappas M, Daeges M, Wasson N, et al. Diagnostic methods for myalgic encephalomyelitis/chronic fatigue syndrome: A systematic review for a National Institutes of Health Pathways to Prevention Workshop. Ann Intern Med. 2015;162: 834-40. [PMID: 26075754] doi:10.7326/M15-0443

      2. Smith MEB, Haney E, McDonagh M, Pappas M, Daeges M, Wasson N, et al. Treatment of myalgic encephalomyelitis/chronic fatigue syndrome: A systematic review for a National Institutes of Health Pathways to Prevention Workshop. Ann Intern Med. 2015;162:841-

      3. [PMID: 26075755] doi:10.7326/M15-0114

      4. Dowsett E, Goudsmit E, Macintyre A, Shepherd C. London Criteria for myalgic encephalomyelitis. In: Report from The National Task Force on Chronic Fatigue Syndrome (CFS), Post Viral Fatigue Syndrome (PVFS), Myalgic Encephalomyelitis (ME). Westcare. 1994. 96-98. Available from: http://www.actionforme.org.uk/Resources/Action for ME/Documents/get-informed/national task force.pdf

      5. Goudsmit E, Shepherd C, Dancy CP, Howes S. ME: Chronic fatigue syndrome or a distinct clinical entity? Health Psychol Update. 2009;18(1):26-33. Available from: http://shop.bps.org.uk/publications/publications-by-subject/health/health-psychology-update-vol-18-no-1-2009.html

      6. Goudsmit EM, Ho-Yen DO, Dancey CP. Learning to cope with chronic illness. Efficacy of a multi-component treatment for people with chronic fatigue syndrome. Patient Educ Couns. 2009;77:231–6. [PMID: 19576714 ] doi:10.1016/j.pec.2009.05.015

      Ellen M Goudsmit PhD FBPsS

      Comment also on Annals of Internal Medicine website under Haney et al.


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    1. On 2015 Dec 15, Diana Frame commented:

      Interesting article and, as a researcher engaged in systematic reviews, I really appreciate the empirical testing done by the authors. I wonder whether the true benefit of machine learning algorithms will be not so much in performing the screening (what is often called "Level I" screening, on titles and abstracts), but in helping to plan search strategies. I could see using this tool at the very beginning of a project to find other non-obvious terms that describe the concepts to be covered in the review. Might be especially helpful as more and more full-text articles become available to churn through. Looking for a needle in a haystack can be challenging for human reviewers, but computers don't get tired.


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    1. On 2016 Aug 24, Ben Goldacre commented:

      This trial has the wrong trial registry ID associated with it on PubMed: both in the XML on PubMed, and in the originating journal article. The ID given is NCT001226810. We believe the correct ID, which we have found by hand searching, is NCT00122681.

      This comment is being posted as part of the OpenTrials.net project<sup>[1]</sup> , an open database threading together all publicly accessible documents and data on each trial, globally. In the course of creating the database, and matching documents and data sources about trials from different locations, we have identified various anomalies in datasets such as PubMed, and in published papers. Alongside documenting the prevalence of problems, we are also attempting to correct these errors and anomalies wherever possible, by feeding back to the originators. We have corrected this data in the OpenTrials.net database; we hope that this trial’s text and metadata can also be corrected at source, in PubMed and in the accompanying paper.

      Many thanks,

      Jessica Fleminger, Ben Goldacre*

      [1] Goldacre, B., Gray, J., 2016. OpenTrials: towards a collaborative open database of all available information on all clinical trials. Trials 17. doi:10.1186/s13063-016-1290-8 PMID: 27056367

      * Dr Ben Goldacre BA MA MSc MBBS MRCPsych<br> Senior Clinical Research Fellow<br> ben.goldacre@phc.ox.ac.uk<br> www.ebmDataLab.net<br> Centre for Evidence Based Medicine<br> Department of Primary Care Health Sciences<br> University of Oxford<br> Radcliffe Observatory Quarter<br> Woodstock Road<br> Oxford OX2 6GG


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    1. On 2015 Nov 02, R Andrew Moore commented:

      Peter has a number of problems, and it is difficult to cover them all in a short space. He has not reported his concerns through the Cochrane Feedback mechanism.

      Our searches did identify a large number of unpublished trials. We deplore this, but are powerless to change things. In a previous review for topical NSAIDs we contacted all identified manufacturers for published or unpublished data. The yield was small (as others have found), but some unpublished studies were brought into the public domain. Waiting for all studies and clinical trial reports of all studies would take forever, and could probably never be achieved. We believe that many of these unpublished studies relate to drugs and/or formulations that have never been manufactured commercially. While these would be of interest in determining what does and doesn’t work, they would have little clinical relevance.

      Peter’s main issue appears to be heterogeneity. Tests for heterogeneity are problematical anyway (Pain. 2000 85:415-24), and the I square of 92% was for all topical diclofenac formulations combined. We demonstrated in the review that the (at least five) different diclofenac formulations produced different results from one another using L’Abbé plots and in our detailed analyses showing large variations in efficacy between them. In the circumstance, a high I square for all combined (clinical heterogeneity) is to be expected. The bulk of the studies on diclofenac were published in the last five years, were of decent quality, and moderate to large size. There were older data for ketoprofen, but again major differences between formulations.

      Trying to determine publication bias using funnel plots or other measures is something of a lost cause (Journal of Clinical Epidemiology 2000;53:207-16). It is especially so with small number of trials (Journal of Clinical Epidemiology 2000 53: 477-484), and making sense of funnel plots is anything but easy for most people (Journal of Clinical Epidemiology 2005 58: 894-901). A useless method seems an odd choice to make to criticise our review.

      There are very good scientific reasons why drug and formulation may play a big part in the efficacy of topical NSAIDs. This is also the case for oral analgesics used in acute pain, where formulation improvements generating rapid absorption confers greater efficacy. Simple lumping strategies may have been permissible in past systematic review methodology, but a more forensic approach is needed now and in the future. This is what we have attempted to do in this latest review.

      Comparisons with Peter’s 2010 review seem inappropriate since that review was based on other reviews that are now out of date.


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    2. On 2015 Oct 28, Peter Gøtzsche commented:

      The authors found that the results were missing from 5900 patients. Furthermore, there was extreme heterogeneity in their meta-analyses, e.g. I square was 92% for the diclofenac trials, which were the most common ones, and there was extreme funnel plot asymmetry, with the largest trials showing the smallest effects (the authors didn’t show funnel plots but I constructed one for diclofenac). Moreover, the trials were industry funded, of relatively poor quality, and the authors analysed published data, not data from clinical study reports, and did not try to obtain all the missing trials and data from the manufacturers.

      The authors concluded that topical NSAIDs are effective in providing pain relief but also cautioned that the large amounts of unpublished data “could influence results in updates of this review.” They certainly could. I believe it is plain wrong to perform meta-analyses on the authors’ data. When I most recently reviewed this area for the BMJ in 2010, I concluded that we don't know whether topical NSAIDs are beneficial (1).

      1 Gøtzsche PC. NSAIDs. Clin Evid (Online). 2010 Jun 28.


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    1. On 2017 Jun 05, Michael Greicius commented:

      Thanks for your interest in the paper. The discrepancy you note arises from the reannotation step described in the manuscript. We reannotated each probe sequence to a gene using the ReAnnotator tool [1]. The used probe-to-gene mapping is listed in supplementary data file S2 [2]. The complete reannotated file is available through sourceforge [3].

      [1]http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0139516 [2]http://science.sciencemag.org/highwire/filestream/631209/field_highwire_adjunct_files/2/Richiardi_Data_File_S2.xlsx [3]https://sourceforge.net/projects/reannotator/files/annotations/


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    2. On 2017 May 30, Xiang-Zhen Kong commented:

      I found that there are 8 of 136 genes (listed below) not available from the Allen Brain website, http://human.brain-map.org/static/download. I used the "Complete normalized microarray datasets". Could you share how you downloaded the expression data with all the 136 genes? Thanks.

      8 genes not available from the Allen Brain website: CDK1 PRSS35 SHISA9 SIX3-AS1 TINCR LINC00617 MS4A8 NUPR1L


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    3. On date unavailable, commented:

      None


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    4. On 2017 May 02, Jonas Richiardi commented:

      A detailed reply has been posted at https://doi.org/10.1101/132746, showing that our original results stand. We provide a short summary here for convenience.

      To a first approximation, all connectivity, like all politics, is local and these two features -- nearness and connectivity -- are challenging to disentangle. Evidence abounds that the majority of connectivity is local, but this critical attribute of functional anatomy is perhaps most efficiently conveyed in a macaque tracer study by Markov et al (2012, see in particular Figure 7). Thus, in undertaking our analysis, we were well aware that spatial nearness is correlated with connectivity, which we addressed using a measure of "fine" tissue-tissue similarity derived from an ontological atlas provided by the Allen Institute. The peer-reviewers at Science were also aware of this confound and insisted on an additional level of tissue-tissue similarity correction which our analysis survives (note that Data File S1 of our paper also included information about "coarse" tissue classes (field coarsetissueclass)).

      The commenters suggest that the tissue-tissue similarity correction we applied is inadequate and point out that in the brain samples we used there remains a significant linear correlation between Euclidean distance and correlated gene expression between brain regions. The r-value for this correlation is 0.1. When the coarse tissue-tissue correction is applied, the r-value for the correlation drops to 0.094. In terms of variance explained, this means that slightly less than 1% of the correlated gene expression measure used in our analyses can be explained by Euclidean distance.

      We thank the commenters for providing an independent replication of our core results, using the same method and data as in our original paper, and our rebuttal can be summarized in the following 5 points:

      • Our analysis survives correction for Euclidean distance (see details in full reply), applied on top of the tissue-tissue similarity correction we used, as well as distance-aware permutation tests. Here, we note that there is an intrinsic contradiction in the commenters' counter-argument that a linear regression of Euclidean distance is inadequate, despite the fact that their critique (see their Figure 1B) is founded on this very same linear correlation.
      • The random clusters generated by the commenters, meant to show the non-specificity of our results, consist of nodes that are roughly twice as close to one another as the nodes in the actual functional networks (see Figure 1 in our full reply).
      • We replicated results of our connectivity gene in both a mouse connectivity analysis and a resting-state fMRI connectivity analysis. The commenters did not generate gene lists for any of their random cluster analyses to try and replicate in these or other independent datasets.
      • Euclidean distance correction will wrongly assign "nearness" to two "neurally distant" regions on the crowns of adjacent gyri (see Figure2 in our full reply). This is essentially the opposite problem of the limitation to tissue-tissue correction that the commenters rightly point out in their figure 1A.
      • Correcting the connectivity of two regions for nearness, using any measure, is bound to dilute the measure of connectivity. That our gene list survives two levels of tissue-tissue similarity correction plus a correction for Euclidean distance and is then replicated in a mouse structural connectivity dataset and a human resting-state fMRI connectivity datasets strikes us as strong support for the conclusion that these genes are important to functional connectivity.

      Detail of these and several other points are available in the full reply paper at https://doi.org/10.1101/132746.


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    5. On 2016 Oct 19, Spiro Pantazatos commented:

      Mind the distance: spatial proximity confounds tissue-tissue gene expression correlations reported in this study.

      This is a novel and very interesting study. However, the authors do not adequately control for spatial proximity, which, contrary to the authors’ claims in the original article, accounts entirely for high within-network strength fraction according to our recent replication/reanalysis of these same data. Furthermore, “null networks”, (i.e. contiguous clusters with center coordinates randomly placed throughout cortex), also have significantly high strength fractions, indicating that high within-network strength fraction is not related to resting-state networks identified by fMRI.

      Here is a link to the full technical commentary and replication/reanalysis write-up with additional supplementary discussion: http://biorxiv.org/content/early/2016/10/04/079202

      And here is a link to the replication/reanalysis code on Github: https://github.com/spiropan/ABA_functional_networks

      The lead authors are aware of these findings and concerns (I notified them via personal email in March, 2016) and they have let me know they plan to respond. I have submitted the commentary for peer review to Frontiers in Neuroscience. If accepted, they have the option to publish a formal rebuttal/response letter there, and/or respond in the comments section here.

      Commentary Abstract

      A recent report claims that functional brain networks defined with resting-state functional magnetic resonance imaging (fMRI) can be recapitulated with correlated gene expression (i.e. high within-network tissue-tissue strength fraction, SF) (Richiardi et al., 2015). However, the authors do not adequately control for spatial proximity. We replicated their main analysis, performed a more effective adjustment for spatial proximity, and tested whether 'null networks' (i.e. clusters with center coordinates randomly placed throughout cortex) also exhibit high SF. Removing proximal tissue-tissue correlations by Euclidean distance, as opposed to removing correlations within arbitrary tissue labels as in (Richiardi et al., 2015), reduces within-network SF to no greater than null. Moreover, randomly placed clusters also have significantly high SF, indicating that high within-network SF is entirely attributable to proximity and is unrelated to functional brain networks defined by resting-state fMRI. We discuss why additional validations in the original article are invalid and/or misleading and suggest future directions.

      Conflict of Interest

      The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


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    1. On 2015 Jun 20, Arnaud Chiolero MD PhD commented:

      Reinvention of cohort studies as platforms to test interventions is probably a great idea. It could give a new life to epidemiology, which seems to be lost in the data-deluge of observational studies.


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    1. On 2016 Apr 06, Jakob Suckale commented:

      This is a good article on how to improve our undergraduate teaching. Below is a verified list of the resources mentioned in the text ordered by usefulness - a few links no longer work as of early 2016 others lead to locked or difficult to get resources, many are very useful.

      Most useful

      Least useful


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    1. On 2016 Feb 21, Joe Newton commented:

      This revealing study, in the absence of established biological markers, and gene sequencing for epistasis, highlights the diagnostic dilemma of uncertainty of animal control systems. For example, "The diagnosis of schizophrenia was made with great rigor by obtaining a consensus between clinical diagnosis of an expert clinician and a research diagnosis generated by MINI-Plus interview. Moreover, diagnostic stability over 1–3 years was examined by reviewing the follow-up notes; ten subjects were excluded from the final sample following this exercise." In addition, the cohort sample size (45 each) is likely too small.

      Statistical method, although following established procedures, is also uncertain for a many degree-of-freedom simultaneous non-linear system. For example, the null HYPOTHESIS, based on smooth Gaussian curves, applied to such a system, is questionable.

      Congratulations to the authors. Joe Ray Newton


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    1. On 2015 Aug 24, Martine Crasnier-Mednansky commented:

      Relevant published data were not taken into consideration by the authors, as indicated below.

      In 2007, Vibrio fischeri was reclassified as Aliivibrio fischeri Urbanczyk H, 2007.

      Transcription of the cpdA gene, encoding the cellular cAMP phosphodiesterase CpdA, is positively regulated by the CRP-cAMP complex, as reported for the closely related Vibrio vulnificus cpdA gene Kim HS, 2009. By itself, this finding infers homeostatic control of the cAMP cellular concentration by CpdA in A. fischeri. This is reminiscent of Pseudomonas aeruginosa CpdA whose gene transcription is also under cAMP positive control Fuchs EL, 2010.

      As regards the periplasmic cAMP phosphodiesterase CpdP, Dunlap PV, 1993 reported its specific activity was 'exceptionally' high, and allowed growth on cAMP as the sole source of carbon and energy. Therefore the role of CpdP in altering the periplasmic cAMP concentration in A. fischeri is important and, as shown by data in figure 4A, likely regulates indirectly the cytoplasmic cAMP concentration by controlling excretion of cAMP from the cell.


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    1. On 2015 Jun 25, David Keller commented:

      Does Deep Brain Stimulation slow the progression of neurodegeneration in early Parkinson disease?

      The authors report that "Subjects receiving an earlier STN-DBS showed a sustained improvement in the activities of daily living and motor complications, never reaching the severe levels of disability reported by Late-Stimulated patients at the time of surgical selection." Did this sustained level of symptom improvement require ongoing increases in DBS stimulation parameters (such as total daily stimulation current)? The need for increasing DBS stimulation to maintain a constant level of symptom improvement implies continued progression of the patient's underlying neurodegeneration. On the other hand, if sustained symptom improvement was achieved while requiring constant or decreasing amounts of electrical brain stimulation, this might reflect slowing or reversal of the neurodegenerative process.

      It would be informative to assess the neurological status of the subjects who received early DBS, with their stimulators turned off, and track these UPDRS scores over time. If the rate of worsening of their stimulator-off UPDRS scores is slower than the rate of worsening for comparable patients who have not received DBS, that would imply possible disease-altering effects for DBS in early PD. Was the crucial stimulator-off UPDRS data collected in this study, and, if so, what do they tell us about how DBS affects the rate of neurodegeneration?


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    1. On 2015 Jul 10, Miguel Lopez-Lazaro commented:

      The authors show a pharmacological strategy that might improve the therapy of a variety of cancer types. However, they tested the anticancer activity of their drug combinations using a preclinical validation approach that, in my opinion, does not reliably predict drug efficacy in cancer patients. Their approach was based on evaluating cytotoxic potency against cancer cells and tumor regression in mice. Although this experimental approach is used by many researchers (including myself in the recent past), it may be inadequate to detect the type of drugs that cancer patients need. I recently proposed an alternative way to assess preclinical anticancer activity: the new drug or drug combination should improve the selectivity (in vitro) and survival rate (in vivo) of the standard treatments used in cancer patients (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4381701/pdf/oncoscience-02-0091.pdf). This patient-oriented approach may help reveal whether or not a combination of kinase and BET inhibitors can improve the efficacy of the existing therapies. I wrote the following letter for Cancer Cell, but the Editors did not find it adequate for their journal. Perhaps someone finds it useful.


      Combination of Kinase and BET Inhibitors to Overcome Resistance to Therapy: Preclinical Validation Required

      Miguel López-Lázaro Department of Pharmacology, Faculty of Pharmacy, University of Seville, Spain

      Kinase inhibitors are the standard of care for a variety of cancer types. Patients treated with kinase inhibitors often develop resistance to therapy, which has been associated with upregulation of tyrosine kinase receptors (RTKs) and subsequent activation of the PI3K pathway. In an article recently published in Cancer Cell, Stratikopoulos et al. showed that BRD4 is important for the feedback activation of several RTKs, and that combined PI3K and BET inhibition blocks PI3K reactivation in a variety of cancer cells. Then, the authors carried out experiments to validate this combination in preclinical in vitro and in vivo models. They observed in several cancer cell types that the cytotoxicity of the combination of a PI3K inhibitor and a BET inhibitor at a fixed concentration was higher than that observed when the inhibitors were tested alone at the same concentrations. They also found a better antitumor activity when mice with breast tumors were treated with kinase and BET inhibitors together than when they were treated with each inhibitor alone at the same doses. The authors discussed that these findings provide the rationale for combining kinase and BET inhibitors to improve therapy in several human cancers (Stratikopoulos et al., 2015).

      Patients with unresectable or metastatic cancers are difficult to cure and require the development of better pharmacological therapies. The first step to developing better therapies is to find good drug candidates or pharmacological strategies for testing. Stratikopoulos et al. find that combined PI3K and BET inhibition sustains PI3K inhibition in a variety of cancer cells, thereby providing the rationale for testing the anticancer potential of this combination. The next step to developing better treatments is to evaluate the new drugs using robust preclinical models; these models should predict whether the anticancer potential of the new drugs is high enough to deserve clinical evaluation. The experimental approach used by Stratikopoulos et al. does not reveal, however, whether or not the combination of PI3K and BET inhibitors deserves clinical testing. The main reason is that their approach was based on evaluating cytotoxic potency in cancer cells and tumor shrinkage in animal models, and these parameters are poor predictors of clinical efficacy. Despite their widespread use, these parameters do not reliably detect the type of drugs that cancer patients need.

      Cancer patients do not need drugs or drug combinations that target their cancer cells at low concentrations if they also target their normal cells at similar concentrations. Cancer patients will probably not benefit from drugs that reduce tumor volumes in mice if they do not extend their lives. Cancer patients need drugs that improve the efficacy of the existing treatments. Establishing the best parameters to measure efficacy in vitro and in vivo is essential, and evidence suggests that selectivity (in vitro) and survival rate (in vivo) are the most reliable parameters to predict drug efficacy in cancer patients (Lopez-Lazaro, 2015c). In vitro, the new treatment should improve the selectivity of the existing drugs when tested in cancer cells versus nonmalignant cells from a variety of healthy tissues (Lopez-Lazaro, 2015a; Lopez-Lazaro, 2015b; Lopez-Lazaro, 2015c). The efficacy of a drug combination should be assessed by testing in cancer cells versus nonmalignant cells if it improves the selectivity of the standard treatment, and not by testing in cancer cells if its cytotoxicity is enhanced in relation to the cytotoxicity induced by each drug alone. It is important to realize that a drug combination that induces a strong cytotoxic synergism in cancer cells will not be clinically effective if it induces a stronger synergism in nonmalignant cells, or that a drug combination that induces synergism in cancer cells and antagonism in nonmalignant cells will not be clinically useful if its selectivity towards cancer cells is lower than that of the standard treatment (Lopez-Lazaro, 2015c). In vivo, the new drug or drug combination should improve the survival rate of the existing therapy when tested under equivalent experimental conditions (e.g., equitoxic doses) in animal models representative of the patients who would eventually receive the new treatment (Lopez-Lazaro, 2015c). Unfortunately, many drugs and drug combinations are tested in cancer patients after showing cytotoxic potency against cancer cells and tumor regression in mice. This preclinical validation approach may contribute to explain why our ability to translate preclinical cancer research to clinical success is remarkably low (Hutchinson and Kirk, 2011). A preclinical validation model based on assessing whether the drug candidates improve the selectivity and survival rate of the standard therapies would facilitate the development of better treatments, and would also prevent many cancer patients from receiving ineffective drugs (Lopez-Lazaro, 2015c).

      In conclusion, Stratikopoulos et al. have discovered a pharmacological strategy that might improve the therapy of a variety of cancer types. However, they assessed the anticancer potential of their strategy using a preclinical validation approach that does not reliably predict drug efficacy in cancer patients. Testing if BET inhibitors improve the selectivity and survival rate of the kinase inhibitors used in oncology would help reveal whether or not kinase and BET inhibitors together can overcome resistance to therapy.

      REFERENCES

      Hutchinson, L. and Kirk, R. (2011). High drug attrition rates--where are we going wrong? Nat. Rev. Clin. Oncol. 8, 189-190.

      Lopez-Lazaro, M. (2015a). A Simple and Reliable Approach for Assessing Anticancer Activity In Vitro. Curr. Med. Chem. 22, 1324-1334.

      Lopez-Lazaro, M. (2015b). How many times should we screen a chemical library to discover an anticancer drug? Drug Discov. Today. 20, 167-169.

      Lopez-Lazaro, M. (2015c). Two preclinical tests to evaluate anticancer activity and to help validate drug candidates for clinical trials. Oncoscience 2, 91-98.

      Stratikopoulos, E.E., Dendy, M., Szabolcs, M., Khaykin, A.J., Lefebvre, C., Zhou, M.M., and Parsons, R. (2015). Kinase and BET Inhibitors Together Clamp Inhibition of PI3K Signaling and Overcome Resistance to Therapy. Cancer Cell. 27, 837-851.


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    1. On 2015 Jul 03, Martine Crasnier-Mednansky commented:

      Gene identification number VC1822 and VCA1045 relate to PTS proteins with A, B, and C domain (not just an A domain as inferred from the text). In accordance with the 'Proposed Uniform Nomenclature' for the PTS proteins Saier MH Jr, 1992, gene VC1822 encodes an Enzyme IIACB<sup>N/D</sup> and VCA1045 an Enzyme IICBA<sup>Mtl</sup> . It would be a great benefit for PTS researchers if the nomenclature was used beyond for example Escherichia coli.

      Based on figure 6A, the authors report the CRP-cAMP complex negatively regulates the expression of tcpA in the absence of the PTS. However, because figure 6A shows there is no significant difference in expression between the cya and the cya ptsH mutant strain or the crp and the crp ptsI mutant strain, and no significant difference in expression between the wild type and the crp or cya mutant strain, it could be concluded from figure 6A that the CRP-cAMP complex does not play a major role in the transcription of tcpA in the TCP-producing AKI medium used by the authors. This conclusion is not supported by previous data indicating CRP-cAMP indirectly regulates negatively the expression of tcpA by inhibiting the transcription of tcpPH (Kovacikova G, 2001). However the cAMP level varies in response to changes in carbon and energy sources. Thus, if the level of cAMP is relatively low in the AKI medium as compared to LB medium, production of TcpA occurs. This provides an explanation for the present observation indicating deletion of crp does not significantly affect production of TcpA (figure 6A). It also provides an explanation why incorporation of a crp mutation in the El Tor strain C6706 allows production of TCP in LB medium (Skorupski K, 1997).

      Figure 6B does not indicate that "…in the EI or Hpr mutants, intracellular cAMP concentrations were significantly higher than that in wt cells" - as stated. In fact, intracellular cAMP concentrations are significantly higher in the cpdA mutant strains, possibly indicating a role for cAMP phosphodiesterase in regulating the cAMP levels.


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    1. On 2015 Jun 26, Donald Forsdyke commented:

      The review covers a field that has occupied geneticist Jianzhi Zhang and colleagues for many years. Their publications are in journals that have usually not permitted direct commenting. The present new PubMed facility allows the release of past comments on their work that previously had only limited circulation (see Yang JR, 2012, Lin F, 2012, Park C, 2013). There are also comments on a paper in PLOS Biology that are accessible at http://www.plosbiology.org/annotation/listThread.action?root=81241.

      The review considers the scope of negative selection, which usually associates with low evolutionary rates and, following Hurst and Smith (1999), only briefly alludes to positive selection, which usually associates with high evolutionary rates. In so doing, the review seems to exclude evidence from studies of positive selection that might reflect on its thesis (see comment on Park C, 2013). Indeed, biochemists have long known that some proteins that are deemed “important” for their host organism evolve slowly under negative selection. Other “important” proteins evolve rapidly under positive selection. Within this broad negative-to-positive range are scattered many other “important” or “essential” or “non-dispensable” proteins. Thus, the review correctly concludes that “the functional importance of a protein only has a weak impact on its evolutionary rate,” and “the evolutionary rate of a protein is predominantly influenced by its expression level rather than functional importance.”

      However, the latter statement can be interpreted as implying that, above a certain minimum, expression level and function are not connected. This misinterpretation could be compounded by (i) the narrow range of papers considered the “foundations in the field,” and (ii) frequent allusions to the functional importance (note singular) of a protein, and (iii) focusing too closely on recently acquired genomic datasets (important as they are).

      There is extensive literature showing that collective functions of proteins, which are dependent on expression level, can underlie biological phenomena (e.g. the Donnan equilibrium; Donnan FG, 1927). Thus, a protein can have both specific (e.g. enzymic) and general functions (1). The discovery of X chromosome dosage compensation (reviewed by Muller in 1948; see http://post.queensu.ca/~forsdyke/xchromos.htm) gave an early indication of the importance of the general role.

      Since many proteins contribute to collective functions, the loss of an individual protein type is more likely to affect its specific function than its contribution to collective functions. Depending on the collective function, some proteins have properties (e.g. size) that would better support that function than other proteins. Thus, there can be degrees of specificity.

      And long ago (McConkey EH, 1982) attention was drawn to the importance of functional constraints due to “quinary” interactions between proteins in the crowded intracellular environment. This referred to “macromolecular interactions that are transient in vivo” which should “constitute an important source of constraints on changes in primary structure” (see also Monteith WB, 2015). The E-R anticorrelation, and selection to avoid protein misinteractions, are further considered in a recent review. A cell mutation that may be deemed as imposing a “gain-in-toxicity,” may function to alert an organism’s cytotoxic T cells that the mutant cell should be destroyed before becoming cancerous. We neglect the immunological concomitants of mutation at our peril (Forsdyke DR, 2015).

      (1)Forsdyke DR (2012) Functional constraint and molecular evolution. In: Encyclopedia of Life Sciences. Chichester: John Wiley.


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    1. On 2015 Jul 21, Weijun Liu commented:

      None


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    2. On 2015 Jul 16, Weijun Liu commented:

      Same flow cytometry figures for cell cycle analysis in Figure 3C and Figure 5A but with different experiment conditions.


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    1. On 2015 Oct 21, Gerard Bruder commented:

      Jesulola et al. (2015) reviewed the literature of EEG alpha asymmetry in relation to behavioral withdrawal in depression. One of the confusing issues in this literature is whether one is referring to hemispheric asymmetry of EEG alpha (α) or brain activity, which is thought to be inversely related to alpha. To their credit, the authors attempted to deal with this by using separate abbreviations for the direction of alpha asymmetry in depression (Lα > Rα) and asymmetry of brain activity (Ra > La). The problem is that these were not consistently used in describing findings in literature. Specifically, on page 60 (3.2.1.4) in referring to the findings of Lopez-Duran et al. (2012), they state that “greater relative left frontal activation (i.e., the opposite of the La>Ra finding for depressed individuals)” but the typical finding for depression is greater right than left frontal activity (Ra>La). Immediately below, in referring to the findings of Bruder et al. (2007), they state “that children whose parents and grandparents were depressed demonstrated greater Lα > Rα EEG asymmetry in the parietal…”, but it should be La>Ra, meaning that activity was less over right than left parietal sites. In section 3.2.2.1 on this page, they state “other studies have examined EEG asymmetry in participants with comorbid anxiety and depression”…and “In general, depressed patients who also had an anxiety disorder had the opposite direction EEG asymmetry (i.e., La>Ra) than depressed patients who did not have comorbid anxiety, although most significant findings have been reported in the parietal sites.” The Bruder et al. (1997) study referred to, which measured EEG alpha in depressed patients with versus without a comorbid anxiety disorder, found greater activity over right than left parietal sites in those with a comorbid anxiety disorder and so it should read “Ra>La”. The other EEG studies referred to were in non-clinical samples or did not include resting alpha measures. They also state, “This contrary finding is unpredicted as it might be expected that co-morbid anxiety and depression might combine to give a much larger Ra>La frontal asymmetry...” The Bruder et al. (1997) study actually found the co-morbid group had Ra>La at frontal sites, whereas depressed patients without an anxiety disorder did not, and so the having both an anxiety and depressive disorder was associated with Ra>La. It was only at parietal sites where the alpha asymmetry in the co-morbid group (Ra>La) was opposite to depressed patients without an anxiety disorder (La>Ra). The favoring of right over left parietal activity in the co-morbid patients could reflect hyperactivation of right parietal regions due to anxious arousal (Heller et al., 1997), hypoactiation of left hemisphere regions or some combination of both (Bruder et al. 1999).

      The authors also discuss several key research issues that require addressing for this field to move forward. The issue of where EEG asymmetry occurs in depression is important and can be dealt with by including frontal and more posterior electrode sites. However, this review does not mention more recent methodological developments, in particular application of current source density (CSD), that can refine the quantification and spatial resolution of EEG measures, improving neuroanatomical and spectral resolution (Tenke et al., 2005; Tenke & Kayser, 2015; Tenke et al., 2015; Kayser & Tenke, 2015). The use of CSD measures also deals with the EEG “reference” problem, which no doubt contributed to differences in alpha asymmetry findings across studies, and can lead to greater consistency of EEG findings between studies using “resting” and task-based EEG measures (Stewart et al., 2014). References Bruder, G.E., Fong, R., Tenke, C.E., Leite, P., Towey, J.P., Stewart, J.E., McGrath, P.J., Quitkin, F.M (1997). Regional brain asymmetries in major depression with or without an anxiety disorder: a quantitative electroencephalographic study. Biological Psychiatry, 41(9), 939-948. Bruder, G.E., Tenke, C.E., Warner, V., Weissman, M.M. (2007). Grandchildren at high and low risk for depression differ in EEG measures of regional brain asymmetry. Biological Psychiatry, 62(11), 1317-1323. Bruder, G.E., Wexler, B.E., Stewart, J.W., Price, L.H. (1999). Perceptual asymmetry differences between major depression with or without a comorbid anxiety disorder: A dichotic listening study. Journal of Abnormal Psychology, 108 (2), 233-239. Heller, W., Nitschke, J.B., Etienne, M.A., Miller, B.A. (1997). Patterns of regional brain activity differentiate types of anxiety. Journal of abnormal Psychology, 106, 376-385. Kayser, J., Tenke, C.E. (2015). Issues and considerations for using the scalp surface Laplacian in EEG/ERP research: A tutorial review. International Journal of Psychophysiology, 97(3), 189-209. Lopez-Duran, N.I., Nusslock, R., George, C., Kovacs, M. (2012). Frontal EEG asymmetry moderates the effects of stressful life events on internalizing symptoms in children at familial risk for depression. Psychophysiology, 49 (4), 510-521. Tenke, C.E., Kayser, J. (2015). Surface Laplacians (SL) and phase properties of EEG rhythms: simulated generators in a volume-conduction model. International Journal of Psychophysiology, 97(3), 285-298. Tenke, C.E., Kayser, J., Abraham, K., Alvarenga, J.E., Bruder, G.E. (2015). Posterior EEG alpha at rest and during task performance: comparison of current source density and field potential measures. International Journal of Psychophysiology, 97(3), 299-309. Stewart, J.L., Coan, J.A., Towers, D.N., Allen, J.J.B. (2014). Resting and task-related prefrontal EEG asymmetry in depression: Support for the capability model. Psychophysiology 51, 446-455.


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    1. On 2015 Jun 12, Pavel Baranov commented:

      Would it be useful to refer to the signal obtained with this technique as heelprinting instead of footprinting?


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    1. On 2015 Nov 15, NephJC - Nephrology Journal Club commented:

      This paper was discussed on Sep 8th in the open online nephrology journal club, #NephJC, on twitter. Introductory comments, prepared by Hector Madariaga, are available at the NephJC [website](www.nephjc.com/obesity-and-transplant/). This controversial topic was discussed in detailed with more than 50 participants, including the authors of the paper (Jennifer McCaughan and Chris Hill) as well as nephrologists, transplant specialists, transplant surgeons, fellows and residents. The highlights of the tweetchat were:

      • The authors did a commendable job in compiling the data for this review together, trying to answer this vexing question about the suitability of kidney transplantation in the obese individual with kidney failure, and provided useful quantitative data on clinical outcomes.

      • The participants acknowledged the difficulties of obese patients losing weight and accessing bariatric surgery pre-transplant. The additional specific concern, which could not be assessed in this systematic review, is that these patients may be challenging for kidney transplantation surgery due to technical aspects (length of stay, wound complications, infections). Balancing equity and utility are crucial from a societal perspective.

      • The consensus was that BMI is an imperfect criterion for kidney transplantation and that each case should be assessed individually. There was still a transatlantic difference, with the European discussants still being wary above a BMI of 40 kg/m2. A transcript and a curated (i.e. Storified) version of the tweetchat are available from the [NephJC website](www.nephjc.com/obesity-and-transplant/). Interested individuals can track and join in the conversation by following @NephJC or #NephJC, or visit the webpage at [NephJC.com](www.nephjc.com).


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    1. On 2015 Dec 11, Mark Johnston commented:

      An interactive protocol from this article is freely available at protocols.io.


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    1. On 2015 Jun 19, Christopher Southan commented:

      Please provide (figshare?) a full list of the 647 candidate genes and the 1,497 for the seven complex diseases from PMID 25077696 so that others can extend these results. The journal should have mandated this.


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    1. On 2015 Jul 13, CREBP Journal Club commented:

      The authors concluded that the “use of written information leaflets in general practice consultations are effective in reducing antibiotic prescribing, and actual antibiotic use by patients and their intention to reconsult for future episodes of illness. It is unclear whether information leaflets also actually affect reconsultation rates.”

      The group generally agreed that this was a well conducted review and liked the arrangement of the data in Table 3. We discussed a number of areas:

      In this review, two reviewers screened 200 titles and abstracts (with no disagreements) and a single author screened the rest with double checking by a second. We noted that individual reviewers miss around 3% of articles; thus, this approach may have led to a number of missed articles (Doust et al 2005).

      The authors stated they would exclude multifaceted interventions but included a study by Francis et al. 2009. It included both information and training in delivering of the intervention (and some members of the journal club believed it could be classed as a shared decision-making intervention). However, the authors did acknowledge this training and stated that it may have affected the results of this study.

      The authors assessed the risk of bias as high for blinding of participants and personnel for each study. GRADE processes suggest that the risk of bias for blinding should be assessed for each outcome (rather than study) so that the objectivity or subjectivity of the specific outcome measure can be taken into account when deciding on whether bias was likely.

      Overall, we believed this was a well conducted review. Clinicians in the journal club had a lively debate about whether they would use information for their patients with common infections. We concluded that it was one tool that you could have in your toolkit to help minimise antibiotic use and the risk of antibiotic resistance.

      References:

      Doust et al. Identifying studies for systematic reviews of diagnostic tests was difficult due to the poor sensitivity and precision of methodologic filters and the lack of information in the abstract. Journal of Clinical Epidemiology 2005; 58 (5): 444-449

      Francis et al. Effect of using an interactive booklet about childhood respiratory tract infections in primary care consultations on reconsulting and antibiotic prescribing; a cluster randomised controlled trial. BMJ 2009; 339:b2885

      O’Sullivan et al. Written information for patients on the use of antibiotics in acute upper respiratory infections in primary care. Cochrane Database of Systematic Reviews 2014; Issue 10: CD011360.

      Full journal club report: CREBP Journal Club


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    1. On 2016 Jul 24, JAVIER MATA commented:

      Sorry not to have written before. We know that selection of an ES of 0.75 in the study establishes a stricter requirement to prove the efficacy of acupuncture than is used in the evaluation of NSAIDs. We used a higher effect size in order to improve the statistical power. A study without statistical significance does not necessarily mean that a relevant association does not exist between the factor under the study and the response. The statistical power of a study is determined by: the variability of the variables within the study, the size of the sample, the level of statistical significance and the effect size. The size of the effect on pain compared to sham acupuncture is 0.4 which is considered ‘moderate’ but the 95% CI around this estimate are wide (0.1, 0.6), this effect size was calculated with manual and electroacupuncture (EA). Use of EA was shown to be superior to manual stimulation alone for knee pain in 2010, but there is not effect size calculation with EA alone and from our experience it is higher.


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    2. On 2015 Jun 15, Arthur Yin Fan commented:

      Why use Effect size 0.75? This is much higher than NIH recommended 0.50 for testing pain medication and higher than hinman's acupuncture trial for chronic knee pain (ES= 0.60).


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    1. On 2017 Jul 10, Randi Pechacek commented:

      Mitja Remus-Emsermann, one of the authors of this paper, wrote a blog post on microBEnet to reveal the "story behind the paper."


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    1. On 2017 Mar 14, Andrea Messori commented:

      Promoting the use of Markov simulation models to study outcomes of total hip arthroplasty

      Andrea Messori

      HTA Section, ESTAR Toscana, Regional Health Service, Firenze, Italy

      Correspondence to: Dr. Andrea Messori, PharmD, HTA Unit, ESTAR Toscana, Regional Health Service, Via San Salvi 12, 50100 Firenze, Italy. andrea.messori.it@gmail.com Fax: +39-05-74701319

      In patients receiving total hip arthroplasty (THA), simulation studies employing Markov models are increasingly being used [1-4]. The aim of these studies is to determine the “typical” clinical outcomes expected on the long term and to generate estimates of cost/effectiveness. If we consider these modelling tools, most of the simulation software published thus far shares the following characteristics:

      a) Health states. The model implements, with minimal variations across different models, the health-states shown in Figure 1 along with the corresponding transitions from one health state to another. The probabilities of individual transitions are shown in Figure 1; these probabilities can be adjusted depending on the specific intervention under examination;

      b) Clinical outcomes after THA. The following outcomes can occur after the first surgery: i) successful outcome; ii) complications; iii) death; the same outcomes can occur also after a repeat surgery for arthroplasty revision.

      c) Life expectancy. The life-expectancy attributed to the simulated patients is determined by considering: a) the age-related and gender-related mortality of a healthy population [5]; b) the mortality attributable to arthroplasty surgery. These two factors are separately managed in different sections of the Markov model (see Figure 1).

      d) Utilities and estimation of QALYs. Utility of patients is assumed to be around 0.72 [6] after surgery. Over the pre-specified time horizon (e.g. 20 years), QALYs are computed on the basis of the health states of the model, their utilities, and the corresponding transition probabilities.

      e) Discounting. The annual discount rate (e.g. 3.5%) is incorporated in the calculation of QALYs according to standard discounting techniques [6].

      As regards the practical use of these computer programs, the simulation models published in the past years are essentially based on two software tools: on the one hand, some researchers have used a general-purpose spreadsheet (namely: Excel by Microsoft) to develop these Markovian programs; on the other, other researchers [3] have used a specific, commercial program (in most cases: TreeagePro by Treeage Software Inc., Williamstown, Massachusetts, USA). The Markovian subroutines written under Excel, as well as the tools developed under Treeage, share a negative characteristic because they are not freely available. Even NICE does not provide these tools when a Technology Appraisal is released. The unavailability of these programming tools is a serious hurdle that limits the scientific advancement of cost-effectiveness research on THA. Hence, in the present report we have tried to facilitate the application of Markov models in the setting of THA by developing a simulation software which is an improved version of the tools previously employed for specific research projects [3]. Our simulation model, that can be downloaded from the following link http://www.osservatorioinnovazione.net/papers/total_hip_arthroplasty.trex, is designed to be run under TreeagePro version 2011 (or subsequent versions). The input variables for the model are shown in the legend to Figure 1. The output of the program is represented by the estimate of total QALYs per patient accrued over the pre-specified time horizon. The software manages only the clinical part of these simulations; however, cost data can be added quite easily by introducing new sections of programming.

      References

      [1] Losina E, Walensky RP, Kessler CL, Emrani PS, Reichmann WM, Wright[ EA, Holt HL, Solomon DH, Yelin E, Paltiel AD, Katz JN. Cost-effectiveness of total knee arthroplasty in the United States: patient risk and hospital volume. Arch Intern Med. 2009 Jun 22;169(12):1113-21.

      [2] Bedair H, Cha TD, Hansen VJ. Economic benefit to society at large of total knee arthroplasty in younger patients: a Markov analysis. J Bone Joint Surg Am. 2014 Jan 15;96(2):119-26.

      [3] Pennington MW, Grieve R, van der Meulen JH. Lifetime cost effectiveness of different brands of prosthesis used for total hip arthroplasty: a study using the NJR dataset. Bone Joint J. 2015 Jun;97-B(6):762-70.

      [4] Mari K, Dégieux P, Mistretta F, Guillemin F, Richette P. Cost utility modeling of early vs late total knee replacement in osteoarthritis patients. Osteoarthritis Cartilage. 2016 Dec;24(12):2069-2076.

      [5] ISTAT. Tavole di mortalità della popolazione italiana—Ripartizione: Italia—Maschi—Anno: 2005, Report of 2010. http://demo.istat.it/unitav2012/index.html?lingua=ita (last accessed 7 May 2014).

      [6] Mason J, Drummond M, Torrance G. Some guidelines on the use of cost effectiveness league tables. BMJ. 1993 Feb 27;306(6877):570-2.

      [7] Jørgensen CC, Kehlet H; Lundbeck Foundation Centre for Fast-track Hip and Knee Replacement Collaborative group.. Time course and reasons for 90-day mortality in fast-track hip and knee arthroplasty. Acta Anaesthesiol Scand. 2017 Apr;61(4):436-444.

      Figure 1. States of the Markov model and transition probabilities.

      The starting point of the simulation model is a Markov node (circled M) from which six branches originate. The explanation for these six branches is the following: 1) surgery for THA; 2) follow-up after first surgery (and also the occurrence of revision surgery): 3) follow-up after revision surgery; 4) follow-up after first surgery with complications; 5) follow-up after revision surgery with complications: 6) death. Second-level branches regard events defined according to the accompanying labels. The symbols adopted in this scheme reflect the syntax required by the Treeage software: Ο, probabilistic node;◄, terminal node.

      Abbreviations: RWD, reward (which in this model represents the incremental increase in quality- adjusted survival).


      The graph of Figure 1 can be downloaded from the following link: http://www.osservatorioinnovazione.net/tenders/tha.gif


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    1. On 2015 Jun 30, Frank Twisk commented:

      Commentary on Jason et al. (2015):

      Towards separate empirical Case Definitions of Myalgic Encephalomyelitis and chronic fatigue syndrome.

      Health Psychol Behav Med. 2015; 3(1): 109-110. doi: 10.1080/21642850.2015.1027705.

      Twisk FNM.

      http://www.tandfonline.com/doi/pdf/10.1080/21642850.2015.1027705


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    1. On 2015 Jun 05, Weiwei Chen commented:

      Weiwei Chen and Xiaonan Yang contributed equally to this work. Xiaonan Yang is an equal contributor.


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    1. On 2015 Sep 30, Peter Gøtzsche commented:

      Augmentation therapy with alpha-1 antitrypsin cannot be recommended

      Chapman et al. published the third trial of α1 proteinase inhibitor (A1PI) augmentation treatment for α1 antitrypsin deficiency.1 The new trial adds very little, if anything, to the results of the two previous trials, which we have summarised in our Cochrane review.2 In the Cochrane review, the decline in lung density measured by CT scan was slightly less on drug than on placebo, difference 1.14 g/l (95% confidence interval 0.14 to 2.14). This minute effect is about the same when the new trial is added to the analysis, difference 0.86 (0.31 to 1.42). The effect of drug on FEV1 was the opposite as that on lung density. In the Cochrane review, FEV1 declined slightly faster on drug than on placebo, difference 20 ml per year (-41 to 1; p = 0.06). Adding the new trial doesn’t change this estimate much, standardised mean difference -0.19 (-0.42 to 0.05). In the accompanying editorial,3 Crystal writes that there is now “evidence of clinical efficacy” and suggests that augmentation treatment should be used earlier than at present, despite the fact that the treatment costs far more than most people earn in a year before taxes. An effect on a surrogate marker is not “evidence of clinical efficacy” and we therefore don’t reimburse or use this treatment in Denmark. We conclude in our Cochrane review: “Augmentation therapy with alpha-1 antitrypsin cannot be recommended, in view of the lack of evidence of clinical benefit and the cost of treatment.”2

      1 Chapman KR, Burdon JG, Piitulainen E, et al. ntravenous augmentation treatment and lung density in severe α1 antitrypsin deficiency (RAPID): a randomised, double-blind, placebo-controlled trial. Lancet 2015;386:360-8.

      2 Gøtzsche PC, Johansen HK. Intravenous alpha-1 antitrypsin augmentation therapy for treating patients with alpha-1 antitrypsin deficiency and lung disease. Cochrane Database Syst Rev 2010;(7):CD007851.

      3 Crystal RG. Augmentation treatment for α1 antitrypsin defi ciency. Lancet 2015;386:319-20.


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    1. On 2015 Dec 22, Allison Bischoff commented:

      It recently came to our attention that an incorrect grant number for the NICHD was cited on this paper. The correct funding information is as follows:

      Grant title: “Tracking neurodegeneration in early Wolfram Syndrome” Hershey, PI NICHD HD070855


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    1. On 2016 May 26, Lydia Maniatis commented:

      Short version: Bottom-up, feed-forward, “feature detection” models that describe perception as a summation process and neurons as “detectors” are inconsistent with logic and the facts, and poking around in the brain will not make them any more credible.


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    2. On 2016 May 26, Lydia Maniatis commented:

      Part 2: An understanding of the role of “higher levels” of processing to CREATE and to ADD structural interpretations to the raw point information registered in “lower levels” - an understanding that led Kanizsa to coin the phrase “going beyond the information given,” is obviously absent when the authors say things like: “These anatomical observations indicate that the visual system is progressively REDUCING [my caps] the amount of information encoded at higher levels of the form vision hierarchy.” If anatomical observations are supposedly contradicting perceptual facts, then there's obviously something wrong with the theory/methods that have led to these conclusions.

      The authors themselves are at least aware that there is a problem with their description of the visual process as feedforward: “One major element missing from this ventral pathway scenario is any role for the ubiquitous feedback connections among areas (VanEssen et al., 1992).” This statement speaks for itself; a story has been created that ignores a major, relevant fact. If this fact couldn't be accommodated, then the story was woefully premature. The brief, vague, unintelligible speculation that follows this admission is not worth discussing.

      The authors are also aware of the ad hoc nature of their conclusions. They hope this will not be a problem for relevance, concluding their paper by saying: “We believe that the observations and models for curved shapes presented here will inform and illuminate these future studies [involving angles and curves].” The authors belief-system aside, the probability that uninformed, ad hoc accounts will end up being corroborated or even useful is really very small. The authors are claiming that they have discovered correlations between shape concepts – curvature – and V4 activity. However, it is a sure thing that, given a particular pattern of activity in any particular V4 neuron, the authors would be in no position to infer anything at all about the stimulus - not even what it isn't. No experiments are needed to make this assertion.

      The term “dimensionality” is thrown around a lot but its meaning and relationship to principles of perception is not at all clear; it obviously involves many unstated and likely unviable assumptions.


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    3. On 2016 May 26, Lydia Maniatis commented:

      Part 1: This article is nonsense, a quality that unfortunately doesn't differentiate it from much (likely most) of the vision science literature today. It's particularly disconcerting that the authors are employing animals, and in particular, monkeys.

      The authors are making a fundamental error in describing the visual process (see below). The error predates the period of German research known as Gestalt psychology. The latter generated cogent logical arguments and empirical evidence against this erroneous, myopic description. The modern proponents of this view are perpetually spinning their wheels, using arbitrary experimental situations to generate inconclusive data fed into ad hoc “models” built on arbitrary assumptions, perpetually adjusting these models, and treating failures and contradictions as temporary bumps in the road. This literature has become an impenetrable swamp of detail unguided by careful observations and lacking organizing concepts.

      Since it involves correlations, there is obviously no point in trying to analyze perception at a neural level unless we have correctly described what it is that we are trying to correlate neural activity with. The authors are naive to the basic challenges that face the visual system as are their descriptions of “stimuli.” They describe the “stimulus” as a face, a shoe, a chair,”containing curves, straight lines, etc. Particular neurons or neural populations are supposed to be particularly sensitive to – i.e to “detect” particular features thus naively described. We're told, for example, that“Many V4 neurons” are “selectively sensitive to curvature extrema” located at “a particular position relative to the center of a closed, curved object.” Leaving aside that “a particular location relative to the center a closed, curve object” conveys no information whatsoever, there are serious theoretical and practical problems with this discussion.

      First, it is a serious mistake to treat perception as a detection and information-reduction problem. The authors frame the problem as: here is a “face;” how does the visual system “detect” it, and how much of the information contained in the “face” is thrown away?

      The problem is that the stimulus with which the visual system is confronted, and must use to create a percept, is never a “face,” a “shoe,” a “chair.” It is a disconnected set of points, which, moreover, are constantly changing location on the constantly-moving retinal surface. Being a sum of disconnected points (the stimulating photons), the stimulus does not intrinsically contain any type of shape or shape feature, such as lines or curves, and it certainly doesn't contain closed, curved objects. If it did, then the problem of computer vision would not be so difficult – we would just tell the computer to pick out – to match - the relevant shapes features. The problem is the computer hasn't been made that can infer/construct the absent forms in the first place. That's why reading the numbers or letters in captchas, a trivial problem for us, is so difficult for robots.

      Any shapes eventually perceived are the result of what are, in effect, inferential processes. Whether and the degree to which the percept will resemble the physical object from which the photon pattern originated (which, again, the authors naively equate with the stimulus) depends on many factors. The percept might resemble it, and it might not. If an actual face, for example, is painted the same color as its background and everything is equally illuminated from all directions, then we will see a single homogeneous color instead of a face. Conversely, a flat surface may appear to possess 3D physical structure.

      These simple examples are enough to show the problem, which is that photons reflected from objects don't possess the properties of these objects, shape or otherwise. Obviously, variations in intensity and wavelength of the photons are required in order for there to be a chance that the percept will resemble, in experienced structure and properties, the physical object. But this is not enough. Even luminance boundaries can't be said to intrinsically possess shape properties; we need to solve the figure-ground problem first, and the illumination/reflectance problem. And as the Gestaltists showed conclusively, non-local points influence what forms will be seen locally, whether or not these forms correspond to actual intensity changes. How these forms are constructed is a non-trivial problem that must be solved before we can refer to “a curve” or “a face.” Wilson and Wilkinson don't see these problems because they describe stimuli in terms of what they see – in terms of the problems already solved by their respective visual systems. (Again, if there were a simple correlation between what they see and the photon information, even in a simple geometrical or mathematical sense, then computers would be better at seeing by now.)

      Therefore, to say that a neuron in V4 simply “detects” a particular feature that lies within its particular receptive field, and feeds this information to higher levels for combination (a summary process) with information from other such neural detectors, flies in the face of perceptual facts (and exhaustive arguments, available in the Gestalt literature, of why these claims can't hold in principle). Even more so given that we know that the activity of visual neurons even below V4 - neurons which “detect,” for example, illusory contours which are not physically present - is determined on the basis of entire visual field (and on the principles by which this field is organized).

      Furthermore, as Teller (1984) pointed out, the logic behind the assumption that a higher level of firing in a particular neuron indicates a special role in “encoding” the “feature” that is supposedly being responded to, is faulty. Perceptual outcomes depend on the relative activity of neurons, not on peak activity of individual neurons. For an example she refers to cone responses and their role in coding color perception. What matters are relative, not maximum, firing rates.


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    1. On 2015 Sep 15, NephJC - Nephrology Journal Club commented:

      This study was discussed on Aug 11th and 12th in the open online nephrology journal club, #NephJC, on twitter. Introductory comments are available at the NephJC website .

      The discussion was quite detailed, with more than 50 participants, including nephrologists, critical care physicians, fellows and residents with additional input from one of the authors, John Kellum. This activity was also supported by the editors and staff at the journal JAMA, which made the full text of the article available for free and provided prizes for best tweet comments.

      A transcript and a curated (i.e. Storified) version of the tweetchat are available from the NephJC website.

      The highlights of the tweetchat were:

      • The authors were to commended for designing and conducting this trial, using an inexpensive and low-risk intervention, and choosing an ideal target population to test it on.

      • The use of biomarkers as damage and alarm markers was quite elegant and thought provoking, but didn’t necessarily convince everyone. Biomarkers, and not just creatinine, do seem to be crucial in future acute kidney injury research.

      • The consensus was that though this trial was quite promising, given other negative data (ERRIKA and RIPHEART) the overall body of evidence is not conclusive yet to drive change in practice. There were concerns about the time required and impact on busy/tight operating schedules, and there was a hope that a mortality powered trial would be done.

      Interested individuals can track and join in the conversation by following @NephJC or #NephJC, or visit the webpage at NephJC.com.


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    1. On 2015 Sep 30, Lydia Maniatis commented:

      This study has very serious problems in terms of both its purpose and its methods.

      Purpose: The authors' guiding question is “how color constancy supports object selection,” an issue they claim is “not understood.” What, exactly, is not understood? If color constancy is achieved, if the percept is clear and the task unambiguous, then what do we hope to gain by having subjects choose a matching surface (out of a limited number of pre-selected options) rather thanfreely adjusting a patch, and then comparing it to a target in order to judge the correspondence between the two? Unless the means of gauging the subjects' perceptual experience is expected to affect the experience itself, then why not choose the most direct, precise, and easy-to-analyze means, rather than a cruder, ambiguous, difficult-to-analyze method deemed to be more “naturalistic”? (The authors themselves acknowledge the crudeness of their method – basically a forced-choice method - in relation to the free-choice “asymmetric matching” method).

      Methods: 1) The authors' use the dimensions “naturalistic” vs “simple” as their independent variables, without explaining what they mean by the terms. The study purports to compare color comparison/selection in a “naturalistic” stimulus vs a “simple” stimulus. The problem with this may be appreciated if we describe the “naturalistic” stimulus, which was actually a series of “simulated naturalistic scenes:” “The target objects were embedded in a multifaceted cube suspended in midair in a room in which the illumination, coming from multiple light sources, varied spatially.” Each facet of the cube contained 49 differently-colored, semi-randomly assigned checks. The illumination on one side was blue or yellow, on the other “standard.” Targets were placed on top of these colored checkerboards. The “simple” stimuli were “flat patches embedded in a textured color background across which simulated illumination varied.” It is not clear why the backgrounds in the “simple” stimulus were not checkerboards matched to those of the “natural” stimuli, or, alternatively, a solid background. Even though the authors state, at one point, that they are controlling for “low-level” features of the stimuli, methodological choices are never clarified beyond the “simple/natural” dichotomy.

      The authors themselves acknowledge the theoretical gap at the heart of this dichotomy: “A systematic characterization of how color constancy varies with the degree of stimulus naturalness is challenging, because a definition of naturalness remains elusive.” So, “Rather than attempting to define dimensions along which naturalness varies, we chose to study two configurations that we judged differed considerably in how natural they appeared.” Despite this vagueness in their chosen dimensions, they qualify the undefined value, “stimulus naturalness,” as a “key factor” in their results (at another point they refer to their stimulus as “nearly naturalistic” and the task as “fairly natural”). The problems here are beyond methodological, they are epistemological – failure to specify conditions in an experimental study means it does not meet the basic demands of the scientific method. Scientists go from nature to the lab in order to control and test potential causal variables; these authors are arguing that going "natural" is a merit - is somehow informative - even if they can't define what they mean by the term.

      2) The authors conclude that “a reasonable degree of color constancy operates effectively in support of object selection.” (Again, why wouldn't it?). The assertion turns the scientific method on its head. This is because the surfaces and illumination were “simulated.” Thus, judgment of whether observers' choices are 'color-constant' or not hinged on assumptions about what the true reflectance of a patch should be judged to be, based on the “simulated” illumination: “To find the reflectance match for each target under a test illuminant, we [derived] a surface reflectance function...using a three-dimensional linear model for surface reflectance...derived from analysis of the spectra of Munsell papers, using the tabulated spectral data reported by Nickerson (1957)...”

      Here's the problem: Let's say I take a black surface, place it on a larger grey surface, and brightly illuminate the smaller surface such that its boundary and the boundary of the illumination precisely coincide. Then, based on my knowledge of the illumination, I declare that a well-functioning lightness constancy mechanism should label the smaller surface “black.” Of course, my subjects would all fail this test. But it will not have been fair test, because observers are required to use the luminance structure of the stimulus to guess at both the reflectance and the illumination of the surfaces; they don't have my inside information about the illumination. If the stimulus itself doesn't support the inference of differential illumination, then the best inference is that illumination is uniform. Similarly, observers (their visual systems) of Radonjic et al's stimuli are called on to make guesses about both the reflectance and the illumination of target surfaces based on stimulus structure (geometric/chromatic). In order for the authors' presumed “correct” answers to constitute a valid test of observers' choices, they would have to provide a specific theory of why these answers constitute the best-guess based on stimulus structure. They would need to explicitly state their assumptions, rather than “cheating” by simply stripping away the “simulated illuminant.” And if they had made and shared any such theoretical assumptions, it would probably be more appropriate to consider observer choices a test of the theory, rather than making the predictions of the theory a test of observer choices. Because if we're studying perception, then the typical observer is never wrong.


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    1. On 2015 Nov 22, Lydia Maniatis commented:

      Another issue that deserves consideration is the distinction between perceptual salience and "detection." The visual system "sees" the data but the percept is a selective description of this data. The so-called laws of perceptual organisation are an attempt to determine how the data are exploited in the attempt to construct a (for practical purposes) veridical representation of the world.

      "Detection" is not the right paradigm for describing the contents of perception, any more than "discovery" is the right description of the scientific process (with respect to discovering (I can't help it) the laws of nature. The phenomena of subjective contours and amodal completions should, on the basis of a detection paradigm, be errors, failure to detect the absence of edges/surfaces.

      Conversely, as the Gestaltists have amply shown, the mere presence of a contour in the stimulus does not mean it will be perceived. But this does not mean it was not "detected."

      We can prove this on the basis that a change in a distant part of the stimulus may make a previously unseen "contour" salient. A very simple example is if we arrange four dots so that they mark the four corners of a square, then we will tend to perceive a square shape, i.e. we will mentally connect the dots to form a square. We will not tend to mentally connect the dots diagonally. But if we remove one of the "corners," then one of these diagonal connections will become salient, as we will typically perceive a triangle shape.

      It's the same with science. Natural laws aren't discovered, they're created with the goal of making them match the facts as closely as possible. Just as with the example above, a chance discovery can cause an entire theoretical structure to rearrange.


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    2. On 2015 Nov 03, Lydia Maniatis commented:

      As is the case with “Bayesians” in general, the authors here perform a sleight-of-hand: They make highly predictable predictions, to which they have attached some type of “Bayesian” rationale; the prediction is borne out; they claim (invalidly) that their “Bayesian framework” has been validated.

      The authors' proposition is that increasing complexity of a "contour" (via increasing bending) decreases its detectability. We are repeatedly told that this is a well-known fact:

      “A number of recent studies have demonstrated that...detection performance declines with larger turning angles” (p. 1)

      “Of course...it is well-known that contour curvature decreases detectability...” (p. 5).

      “Contour curvature is well known to influence human detection of contours” (p. 12).

      Lo and behold, the authors' results show that “ subjects are sensitive to the complexity of the target contour's shape, as expected under the Bayesian framework and the assumed generative model. This finding gives strong prima facie support for the Bayesian approach...” (p. 8). Thus, our predictable prediction comes out as expected, and is treated as corroboration of our fundamentally post-hoc model. This train of thought is analogous to my claiming that invisible angels push the sun up every morning, and consider the coming of the dawn as prima facie evidence for my theological framework. But in fact, my angel hypothesis can only be corroborated by testing its unique components - the existence of invisible angels. It happens to be vague and untestable. Similarly, the results of this study can only validate the “Bayesian framework” by clarifying and testing its uniquely “Bayesian” assumptions (whatever these may be), not by straightforwardly modeling "well-known" facts.

      In addition, the authors frame their question in a way that doesn't reflect a real perceptual problem, but is amenable to their “model.” They state that “The detection of coherent objects among noisy backgrounds is an essential function of perceptual organization, allowing the visual system to distinguish discrete, whole forms from random clutter” (p. 1). As I look around me, all I see are discrete, whole forms. None is set against a background of noise. Nor are their long, skinny objects (“open contours”). The problem is framed this way because it corresponds nicely to the authors' “hammer.” The task is an awkward, not a natural one, akin to exploring motor patterns by tying subjects legs together. It is not an obvious candidate for modeling natural perceptual processes; we are told that conditions were set so that, in a pilot study, subjects performed near 75% “correct.” Results were, predictably, mixed.

      The claims made are easy to falsify. Specifically, the authors are suggesting that subjects performance in detecting the “contours” presented is due to “noisy” encoding of turning angles, thus “depressing their performance relative to an ideal observer in possession of perfect image data. “ (p. 14). The definition of contours as chains of points of identical luminance in a “noisy” background, as well as the reference to “perfect image data” reveals a certain naivete on the part of the authors vis a vis basic principles of visual perception. Their model would obviously fail to predict performance of subjects shown images that produce illusory contours, or amodal completions, for example. It would not even predict grouping of points with gaps between them – for example, a straight contour composed of identical black pixels alternated with white ones.

      Finally, one of the authors, (Feldman) has repeatedly and strenuously argued against the “frequentist” definition of probability (e.g. Feldman, 2015), contrasting it with the belief-based “Bayesian” definition. Here, he inscrutably cross-breeds “frequentism” and “Bayesianism,” referring, for example, to a “Bernoulli Bayesian decision problem ” (p. 13)). Thus, it is not clear where, for Bayesians, “frequentism” ends and belief begins.

      References

      Feldman, Jacob. "Bayesian models of perception: a tutorial introduction." Wagemans, J eds (2014).


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