1. Department of Gastroenterology401 General Military Hospital of Athens Athens Greece
2. Department of Gastroenterology and HepatologyUniversity of Zurich Zurich Switzerland
3. Department of Internal Medicine, Second Medical Clinic, Ippokration HospitalAristotle University of Thessaloniki Thessaloniki Macedonia Greece
4. First Department of Pharmacology, School of MedicineAristotle University of Thessaloniki Thessaloniki Macedonia Greece
5. Department of Internal MedicineAgios Pavlos General Hospital Thessaloniki Macedonia Greece