1. Department of Gastroenterology and Hepatology; University Hospital Heidelberg; Heidelberg Germany
2. Division of Gastroenterology and Hepatology, Department of Internal Medicine III; Medical University of Vienna; Vienna Austria
3. Department of Neurology; University Hospital Dresden; Dresden Germany
4. Sections of Digestive Disease and Transplantation and Immunology, Departments of Medicine and Surgery; Yale University School of Medicine; New Haven CT