1. Department of Medicine Second Medical Clinic,Aristotle University of Thessaloniki Ippokration Hospital Thessaloniki Greece
2. Department of Gastroenterology University Hospital of Larisa Larisa Greece
3. First Laboratory of Pharmacology School of Medicine Aristotle University of Thessaloniki Thessaloniki Greece
4. Division of Gastroenterology and Hepatology Medical University Department Kantonsspital Aarau Aarau Switzerland