Diabetes has issued two expressions of concern (EOCs) for papers co-authored by leading diabetes researcher Kathrin Maedler, adding to her previous count of one retraction and three corrections.
Both papers were questioned on PubPeer, alongside several others co-authored by Maedler, who is based at the University of Bremen in Germany. As we previously reported, PubPeer comments have led to one retraction for Maedler in the Journal of Biological Chemistry (JBC), and corrections in various other journals.
One of those corrections has now earned an EOC from Diabetes, which also extends to the original paper. Here are the notices, which asks the University of Bremen to investigate further:
On the basis of the recommendation of the American Diabetes Association’s Panel on Ethical Scientific Programs (ESP), the American Diabetes Association, the publisher of Diabetes, is issuing this expression of concern to alert readers to questions about the reliability of the data in the above-cited article and erratum.
After readers contacted the journal about potentially duplicated images in the article, the ESP reviewed the following issues:
- In the erratum for Fig. 5D (Diabetes 2014;63:3974; DOI: 10.2337/db14-er11), the “cleaved Caspase 3” panel (lanes 7 and 8 in the original blots and lanes 4 and 5 in the corrected version) closely resembles the “cleaved Casp3” panel in Fig. 3D in the original version of the article (Diabetes 2008;57:645–653; DOI: 10.2337/db07-0847).
- Likewise, in the original article, Fig. 5D (lanes 4 and 5) resembles the “cleaved Casp3” panel in Fig. 3D.
- In the erratum (Diabetes 2014;63:3974; DOI: 10.2337/db14-er11), the “cleaved Caspase 3” panel, lanes 1 and 2, closely resembles a horizontal mirror image of Fig. 2F, TCF7L2 panel, lanes 3 and 4, from a 2009 article by the same author group in the journal Human Molecular Genetics (Hum Mol Genet 2009;18:2388–2399; DOI: 10.1093/hmg/ddp178). In addition, lanes 4 and 5 of the corrected Fig. 5D in the erratum closely resemble a horizontal mirror image of Fig. 2F, TCF7L2 panel, lanes 1 and 2, of the Human Molecular Genetics article.
It should be noted that an erratum to replace Fig. 2F in the Human Molecular Genetics article was published in March 2015 (http://hmg.oxfordjournals.org/content/early/2015/03/07/hmg.ddv075.full).
The Panel has contacted the corresponding author to inform her of these concerns, and the corresponding author’s institution, the University of Bremen, has been asked to undertake an investigation of these issues. Diabetes will make a final decision on the publication status of this article after the journal obtains more information on the reliability of the data and conclusions presented in the article.
The 2005 paper, “Transcription Factor 7-Like 2 Regulates β-Cell Survival and Function in Human Pancreatic Islets,” has been cited 151 times, according to Thomson Reuters Web of Science. Its erratum has not been cited.
On the basis of the recommendation of the American Diabetes Association’s Panel on Ethical Scientific Programs (ESP), the American Diabetes Association, the publisher of Diabetes, is issuing this expression of concern to alert readers to questions about the reliability of the data in the above-cited article.
After readers contacted the journal about the potential republication of images from this article, the ESP reviewed the following issues:
- In a 2009 PLOS ONE article (PLoS ONE 2009;4:e4394; DOI: 10.1371/journal.pone.0004394), lanes 1 and 2 of the “b-Actin” panel in Fig. 1A appear to be the same as lanes 2 and 3 of the “Actin 42 kDa” panel in Fig. 3G of this 2006 Diabetes article.
- It should be noted that a correction to replace Fig. 1A was published in PLOS ONE in May 2015 (PLoS ONE 2015;10:e0117766; DOI: 10.1371/journal.pone.0117766).
- Also, lane 4 of the PDX1 panel in Fig. 1E of a 2011 article in The Journal of Biological Chemistry (J Biol Chem 2011;286:17144–17155; DOI: 10.1074/jbc.M110.210526) closely resembles lane 1 of the FLIP 55KDa panel of Fig. 3D of this 2006 Diabetes article. Also, lane 8 of the PDX1 panel of Fig. 1E of The Journal of Biological Chemistry article closely resembles lane 5 of the FLIP 55KDa panel in Fig. 3D of this Diabetes article.
- It should be noted that The Journal of Biological Chemistry article was retracted in November 2015 (DOI: 10.1074/jbc.A110.210526).
Despite the published amendments to the PLOS ONE and The Journal of Biological Chemistry articles, the Panel still has concerns about the reliability of the data and conclusions presented in this article. The Panel has contacted the lead author (Dr. Kathrin Maedler, who is the corresponding author on the PLOS ONE and The Journal of Biological Chemistry articles) to inform her of these concerns and has asked the author’s institution, the University of Bremen, to undertake an investigation of these issues. Diabetes will make a final decision on the publication status of this article after the journal obtains more information from the university.
Diabetes is a member journal of the Committee on Publication Ethics (COPE) (publicationethics.org). As such, the ESP refers to COPE’s guidelines and best practices when reviewing potential violations of the journal’s publication policies.
This 2006 paper has been cited 97 times.
We’ve contacted Maedler to comment on the EOCs. Earlier this year, she sent us a statement, noting:
Mistakes have indeed occurred by reusing loading controls from different experiments, which was not apparent to me at the time of publication. We have immediately put the appropriate actions in place to avoid such in the future. Several replicate experiments were provided to the respective journals, which fully confirm scientifically correct data, and we could correct the wrongly placed loading controls in our publications. Journals investigated all provided full blots of the experiments, which led to correction of the data.
I am thankful to the journal editors to have had the opportunity to correct the mistakes publicly and these corrections are in no way altering interpretation of our results and the conclusions of the original papers.
In that earlier statement, Maedler also noted that the University of Zurich in Switzerland, where she completed her PhD, carried out a separate inquiry into various papers from her thesis, and found no evidence of misconduct. A Zurich spokesperson confirmed Maedler’s claims.
Andreas Breiter, vice president for research at the University of Bremen, told us the university could not comment on the case, but said:
Please rest assured that the University of Bremen is taking any necessary measures to ensure the code of good research practice in accordance with the rules by the German Research Foundation (DFG). We will inform the public accordingly.
Christian Kohler, staff liaison for the panel on ethical scientific programs at the American Diabetes Association (ADA), which publishes Diabetes, said the publisher would not comment beyond published statements.
Hat tip: Rolf Degen
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