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