Mizutani A, Okajima K, Uchiba M, Noguchi T. Activated protein C reduces ischemia/reperfusion-induced renal injury in rats by inhibiting leukocyte activation. Blood. 2000;95(12):3781-3787. Mizutani A, Okajima K, Uchiba M, Isobe H, Harada N, Mizutani S, Noguchi T. Antithrombin reduces ischemia/reperfusion-induced renal injury in rats by inhibiting leukocyte activation through promotion of prostacyclin production. Blood. 2003;101(8):3029-3036.

The Editors wish to retract the 15 June 2000 and 15 April 2003 (prepublished 12 December 2002) articles cited above. The retractions were prepublished in First Edition on 29 March 2013. The institutional investigations by the Oita University and the Nagoya Municipal University in Japan, which focused on the research of Kenji Okajima and Akio Mizutani, concluded that the data presented in the Blood 2000 paper were obtained using fraudulent methods and hence cannot be considered reliable. Specifically, Figure 3B and Figure 3D are duplicated and rotated images of the same stained slide. In addition, some of the data were reused, without attribution, between the 2000 and 2003 Blood papers. Figure 1A-B and Figure 4A in both papers show identical data through 24 hours. The same applies to Figure 6A in the 2000 paper, Figure 7A in the 2003 paper, Figure 7A-C in the 2000 paper, and Figure 8A-C in the 2003 paper. The figure legends and Methods in the 2003 paper do not indicate that these data were in part previously published. In addition to the issue of potential data reuse without attribution, the journal found possible problems with the data itself, because the figures up through 24 hours are identical, yet purported to result from experiments 3 years apart, consisting of different group sizes for the sham and R/I saline groups between the 2 papers.

Dr Uchiba agreed to the retractions. Dr Okajima was contacted by Blood, but did not respond. The remaining authors could not be contacted.