1. Division of Gastroenterology and Hematology/Oncology, Department of Medicine; Asahikawa Medical University; Asahikawa; Hokkaido; Japan
2. Division of Hepatobiliary and Pancreatic Disease, Department of Internal Medicine; Hyogo College of Medicine; Hyogo; Japan
3. Internal Medicine, Institute of Gastroenterology; Tokyo Women's Medical University; Tokyo; Japan
4. Division of Gastroenterology and Hepatology; Niigata University Graduate School of Medical and Dental Sciences; Japan
5. Department of Gastroenterology and Metabology; Ehime University Graduate School of Medicine; Ehime; Japan