1. Center for Gastroenterology; Teine-Keijinkai Hospital; Sapporo Japan
2. Department of Gastroenterology and Hepatology; Hokkaido University Hospital; Sapporo Japan
3. Department of Gastroenterology and Hepatology; Okayama University; Okayama Japan
4. Department of Gastroenterology and Hepatology; Tokyo Medical University; Tokyo Japan
5. Department of Medical Oncology and Hematology; Sapporo Medical University School of Medicine; Sapporo Japan
6. Department of Gastroenterology, Aizu Medical Center; Fukushima Medical University; Fukushima Japan
7. Division of Gastroenterology, Department of Medicine; Kurume University School of Medicine; Kurume Japan
8. First Department of Internal Medicine; Gifu University Hospital; Gifu Japan
9. Department of Gastroenterology; Teikyo University Mizonokuchi Hospital; Kawasaki Japan
10. Department of Gastroenterology; Saitama Medical University International Medical Center; Hidaka Japan
11. Department of Gastroenterology and Hepatology; Yamaguchi University Graduate School of Medicine; Ube Japan