1. Department of Medicine III, RWTH-University Hospital Aachen, Pauwelsstrasse 30, 52074 Aachen, Germany
2. Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry, RWTH-University Hospital Aachen, Pauwelsstrasse 30, 52074 Aachen, Germany
3. Medical Care Center, Dr. Stein and Colleagues, Mönchengladbach, Germany
4. Section of Gastroenterology and Hepatology, Department of Internal Medicine, Maastricht University Medical Centre (MUMC), Maastricht, Netherlands