1. Gastroenterological Center Yokohama City University Medical Center Yokohama Japan
2. Departments of Gastroenterology and Hepatology Hokkaido University Hospital Sapporo Japan
3. Departments of Gastroenterology and Hepatology Ogaki Municipal Hospital Ogaki Japan
4. Division of Molecular and Cellular Medicine National Cancer Center Research Institute Tokyo Japan
5. Division of Pharmacotherapeutics, Keio University Faculty of Pharmacy Tokyo Japan
6. Department of Surgery Ogaki Municipal Hospital Ogaki Japan
7. Department of Gastroenterological Surgery I Hokkaido University Hospital Sapporo Japan
8. Department of Surgical Pathology Hokkaido University Hospital Sapporo Japan
9. Department of Gastroenterology Yokohama City University Yokohama Japan