1. Paul-Langerhans-Group for Integrative Physiology; German Diabetes Center; Düsseldorf Germany
2. German Center for Diabetes Research; Partner Düsseldorf Germany
3. Institute for Clinical Diabetology; German Diabetes Center; Düsseldorf Germany
4. Department of Endocrinology and Diabetology, Medical Faculty; Heinrich-Heine University Düsseldorf; Germany