Following accusations by independent bloggers in Japan and Germany, the American Heart Association (AHA) has issued an Expression of Concern about five papers published in AHA journals co-authored by Hiroaki Matsubara, a prominent cardiologist and researcher at Kyoto Prefectural University in Japan. In addition to his many papers exploring the basic science of the renin-angiotensin system, Matsubara was the chief investigator of the KYOTO HEART Study, a randomized, open-labeled study studying the add-on effect of valsartan to conventional therapy in high-risk hypertension.

Questions about Matsubara’s work were initially raised last year on a Japanese blog and then pursued in three English language posts (here, here and here) on a German site, the Abnormal Science Blog. Abnormal Science reported evidence of serious scientific misconduct in 12 papers in which Matsubara was the only common co-author. The AHA posted its Expression of Concern on Monday, which was subsequently reported by Retraction Watch.

The three posts on Abnormal Science demonstrate repeated examples of  image manipulation and copying, as well as self-plagiarism. The non-AHA journals cited by Abnormal Science include Kidney International, Biochemical and Biophysical Research Communications, and Journal of Molecular and Cellular Cardiology. At least one paper, in Molecular and Cellular Biochemistry, has been  retracted “due to a mistake of duplicating the publication of original data” that already had appeared in Circulation Research. Here is how Abnormal Science summarized its initial findings in several of the papers:

It is apparent that band images from ‘real’ blots may have been digitally reassembled into new blot images pretending to be derived from distinct experimental settings. Since ‘reconfigured blots’ have been densimetrically scanned and the results illustrated in tables and figures, we are presumably confronted with a case of severe data fabrication.

These are the five papers cited by the AHA, including the number of citations as reported by Retraction Watch:

• “Angiotensin II Type 2 Receptor Inhibits Epidermal Growth Factor Receptor Transactivation by Increasing Association of SHP-1 Tyrosine Phosphatase,” published in Hypertension in 2001 and cited 30 times, according to Thomson Scientific’s Web of Knowledge
• “Enhancement of Ischemia-Induced Angiogenesis by eNOS Overexpression,” published in Hypertension in 2003 and cited 64 times
• “Angiogenesis by Implantation of Peripheral Blood Mononuclear Cells and Platelets Into Ischemic Limbs,” published in Circulation in 2002 and cited 167 times
• “Aldosterone Directly Induces Myocyte Apoptosis Through Calcineurin-Dependent Pathways,” published in Circulation in 2004 and cited 57 times
• “Angiotensin AT1 and AT2 Receptors Differentially Regulate Angiopoietin-2 Vascular Endothelial Growth Factor Expression and Angiogenesis by Modulating Heparin Binding–Epidermal Growth Factor (EGF)–Mediated EGF Receptor Transactivation,” published in Circulation Research in 2001 and cited 143 times