Expression of Concern on “Influence of gastrectomy on cortical and cancellous bones in rats”

Abstract EN

Gastroenterology Research and Practice would like to express our concern with the article titled “Influence of gastrectomy on cortical and cancellous bones in rats”, published in 2013 [1].

It was brought to our attention that a later article by the same authors published in Journal of Nutritional Science and Vitaminology in 2014 [2] 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: (1)In Figure 1 of Journal of Nutritional Science and Vitaminology, the gastrectomy data for all six variables are discrepant with those for the same variables in Figure 3 of Gastroenterology Research and Practice (2)In Figure 1 of Journal of Nutritional Science and Vitaminology, the control data for work to failure in the femoral diaphysis are discrepant with those for the same variable in Figure 3 of Gastroenterology Research and Practice (3)In the legends to Figures 1, 2, and 3 in Gastroenterology Research and Practice, the superscript letters denoting statistical significance are stated to be related to ‘versus gastrectomy’ though they are above the gastrectomy data.

This should probably have read ‘versus control’; (4)In Journal of Nutritional Science and Vitaminology, control and gastrectomy groups had vehicle administered by oral gavage, but in Gastroenterology Research and Practice there is no mention of vehicle administration in either group (5)No funding statement was provided (6)The study was stated to have been conducted at Hamri Co (Ibaraki, Japan), yet none of the authors had affiliations there and neither did any of the acknowledged contributors (7)Co-author Yoshihiro Sato, since deceased, previously admitted he was given gift authorship on other articles by Jun Iwamoto