1. Institute of Endocrinology, Diabetes, Metabolism (V.P., D.Mil., S.P., M.Dj., M.Do., S.D., D.Mic., G.C.), Serbia and Montenegro;
2. Institute of Abdominal Surgery (P.P.), Serbia and Montenegro;
3. University Clinical Center, Belgrade, Laboratory Consilium (J.G.), 11000 Belgrade, Serbia and Montenegro;
4. Department of Physiology (C.D.), E-15780 Santiago de Compostela, Spain
5. Complejo Hospitalario, Endocrine Section (F.F.C.), Faculty of Medicine, Santiago de Compostela University, E-15780 Santiago de Compostela, Spain