[1] Heinrich Heine Univ, Fac Med, Inst Anat 2, D-40225 Dusseldorf, Germany
[2] German Diabet Ctr, Inst Clin Diabetol, Dusseldorf, Germany
[3] German Ctr Diabet Res DZD, Munich, Germany
[4] Heinrich Heine Univ, Fac Med, Dept Endocrinol & Diabetol, Dusseldorf, Germany