1. Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan
2. School of Medicine, National Yang Ming Chiao Tung University, Taipei 112, Taiwan
3. Division of Gastroenterology and Hepatology, Min-Sheng General Hospital, Taoyuan 330, Taiwan
4. Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
5. Department of Medicine, Renown Regional Medical Center, Reno, NV 89502, USA
6. Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112, Taiwan
7. Department of Medical Research, Taipei Veterans General Hospital, Taipei 112, Taiwan
8. Institute of Pharmacology, National Yang Ming Chiao Tung University, Taipei 112, Taiwan