1. Department of Gastroenterology, 424 Army General Teaching Hospital, Thessaloniki
2. 2nd Surgical Clinic, Gennimatas General Hospital, Thessaloniki
3. 3rd Department of Pediatrics, Medical Faculty, Aristotle University, Hippokration Hospital, Thessaloniki
4. 1st Department of Medicine, A.H.E.P.A. Teaching Hospital, Thessaloniki, Greece