1. Division of Gastroenterology, Department of Internal Medicine, Nippon Medical School Chiba Hokusoh Hospital, Japan
2. Core Research Facilities for Basic Science, Research Center for Medical Sciences, The Jikei University School of Medicine, Japan
3. Division of Gastroenterology and Hepatology, Shinmatsudo Central General Hospital, Japan
4. Division of Gastroenterology and Hepatology, Department of Internal Medicine, The Jikei University School of Medicine Katsushika Medical Center, Japan
5. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Nippon Medical School, Japan