1. Division of Gastroenterology and Hepatology; Department of Internal Medicine III; Medical University of Vienna; Vienna; Austria
2. Schering-Plough Corporation; a subsidiary of Merck, Inc.; Global Medical Affairs; Kenilworth; NJ; USA
3. Schering-Plough Corporation; a subsidiary of Merck & Co.; Global Medical Affairs; Oss; The Netherlands
4. Medical Affairs Immunology Europe; Janssen Biologics Europe; Leiden; The Netherlands