1. Department of Gastroenterology and Metabolism, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan
2. Department of Gastroenterology, Hiroshima Prefectural Hospital, Hiroshima, Japan
3. Department of Gastroenterology, Hiroshima Red Cross Hospital & Atomic-bomb Survivors, Hiroshima Red Cross Hospital & Atomic-bomb Survivors Hospital, Hiroshima, Japan
4. Department of Surgery, Applied Life Sciences Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
5. Department of Anatomical Pathology, Hiroshima University Hospital, Hiroshima, Japan