1. Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
2. Division of Gastroenterology and Hepatology, Min-Sheng General Hospital, Taoyuan, Taiwan, ROC
3. School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC
4. Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
5. Department of Medicine, Renown Regional Medical Center, Reno, Nevada, USA
6. Department of Medical Research, Taipei Veterans General Hospital, Taipei, Taiwan, ROC