1. Department of Internal Medicine (M.K., C.P.), University of Pisa, 56126 Pisa, Italy
2. Department of Technosciences for Medical Application and Research (M.P.), Consiglio Nazionale delle Ricerche Institute of Clinical Physiology, 56124 Pisa, Italy
3. Division of Endocrinology and Metabolism (C.-H.A.), Department of Internal Medicine III, Medical University of Vienna, A-1090 Vienna, Austria
4. Institute fur Stoffwechselforschung (T.K.), D-60327 Frankfurt, Germany
5. St. James’s Hospital (M.-P.C.), Dublin, 8 Ireland
6. The Medical Research Laboratories (A.F.), Clinical Institute and Medical Department M (Diabetes and Endocrinology), Aarhus University Hospital, DK-8000 Aarhus, Denmark
7. Institute for Research in Extramural Medicine Institute (J.D.), Vrije University, 1081 BT Amsterdam, The Netherlands