1. Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
2. Liver Center, Cathay General Hospital Medical Center, Taipei, Taiwan
3. School of Medicine, Taipei Medical University, Taipei, Taiwan
4. Division of Gastroenterology, Department of Internal Medicine, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan
5. Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Warren 1007, 55 Fruit Street, Boston, MA 02114, USA