A gastroenterology journal has issued an extensive expression of concern about a 2013 paper by Yoshihiro Sato, a Japanese endocrinologist who has posthumously been climbing the Retraction Watch leaderboard. (He’s now ranked number three, ahead of Diederik Stapel.)
To call the statement an “expression of concern” is like calling Charles M. Schulz a talented cartoonist, or Escoffier a pretty good cook. Indeed, the journal expresses so much concern, about, well, so much, that we’re not sure what in the paper would be left unscathed.
Sato, formerly of Hirosaki University, currently has 77 retractions for a range of misconduct-related issues including likely data fabrication and duplication.
The article, “Influence of gastrectomy on cortical and cancellous bones in rats,” appeared in Gastroenterology Research and Practice. Two of the authors, Jun Iwamoto and Hideo Matsumoto, were affiliated with Keio University School of Medicine. (Iwamoto has 57 retractions, one behind Stapel.) Sato at the time was listed as being with Mitate Hospital in the city of Fukuoka.
The paper has been cited six times, including once by the expression of concern, acording to Clarivate Analytics’ Web of Science. According to the journal:
Gastroenterology Research and Practice [GRP] would like to express our concern with the article titled “Influence of gastrectomy on cortical and cancellous bones in rats”, published in 2013 . It was brought to our attention that a later article by the same authors published in Journal of Nutritional Science and Vitaminology [JNSV] in 2014  used some of the same animals as in the Gastroenterology Research and Practice article, but the second article had an additional arm of rats given vitamin K and did not cite the first article. The authors did not mention in the Gastroenterology Research and Practice article that they had also used an additional arm of rats given vitamin K. In addition to the partial redundant publication, readers should be aware of the following concerns and discrepancies:
The notice goes on to list seven points, ranging from discrepancies in the data to the fact that the authors said they conducted the research at a company with which they appear to have no connection. The last point states:
Co-author Yoshihiro Sato, since deceased, previously admitted he was given gift authorship on other articles by Jun Iwamoto
According to the journal:
We asked the first author, Jun Iwamoto, to respond to these concerns and provide the raw data, but he did not explain the discrepancies or provide the data. We asked the Dean of Keio University School of Medicine and the Provost of Keio University to investigate. We were informed by a contact from the Research Administration at Keio University School of Medicine that an investigation was complete and we would be contacted by Dr. Iwamoto, but we were not told the outcome of the investigation and our specific concerns were not addressed.
Andrew Grey and Mark Bolland, of the University of Auckland, in New Zealand, have been urging journals to look closely at Sato’s research — efforts that have led to many retractions. Grey told us that:
we think retraction of the GRP paper is very clearly warranted – as it stands, the GRP paper is very clearly unreliable, and the problems cannot be resolved.
Grey said he and Boland asked Hindawi about the status of the article and were told that the publisher was waiting on word from Keio University, where the research was conducted:
but it is hard to see how anything the institution reports (if it ever does) could render the publication reliable.
We raised concerns about the GRP paper and its paired/partially duplicated paper in JNSV [now retracted] … The concerns were about authorship misconduct, funding uncertainty, unacknowledged duplicate data reporting (42% of the data in the GRP paper were reported in the JNSV paper), data discrepancies and methodological discrepancies.
The GRP/Hindawi staff did a very good job of trying to resolve the problems we identified with the data, and eventually managed to obtain the raw data. As the detailed EoC outlines, the animals in the gastrectomy groups in the raw data files are not the same in the datasets for the 2 papers, although they should be, as they are from the same randomization. This anomaly is unexplained. Further, using the data in the raw data files introduces more anomalies with the published data, in body weight in the gastrectomy group in the GRP paper. Neither does the raw data resolve the problem of the discrepant data for the control group in work to failure fig 3(a) GRP paper (reported data are wrong, according to the raw data) vs fig 1 A JNSV paper (reported data are correct, according to the raw data)
The EoC states “Co-author Yoshihiro Sato, since deceased, previously admitted he was given gift authorship on other articles by Jun Iwamoto”. In fact, Dr Sato’s statement indicates systematic gift/honorary authorship with Dr Iwamoto beginning in 2002.
Finally, this raises an important question. When there is an undisputed context of a wide range of behaviours that compromise the integrity of publications (eg >80 retractions within this group of investigators), when should the burden of proof shift, such that journals and publishers no longer need very stringent evidence to retract papers with unresolved serious concerns?
Matt Hodgkinson, head of research integrity at Hindawi, which publishes the journal, told us:
We are not certain to what extent the issues described in the notice affect the results in the Gastroenterology Research and Practice article. We hoped the institutional investigation would clarify this, but we have not been informed of the outcome. Based on advice from our board and COPE guidelines, we decided to post the Expression of Concern to be transparent about the process and the concerns identified by the journal and Dr. Grey. We are following up with the institution and MEXT, the Japanese ministry with oversight of investigations (as suggested by Dr. Grey). Depending on the responses, or lack of response, from these organisations, we will consider what further action to take to correct the literature.
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