1. Department of Gastroenterology and Metabolism, Applied Life Science, Institute of Biomedical & Health Science, Hiroshima University, Hiroshima, Japan
2. Department of Gastroenterology, Hiroshima Prefectural Hospital, Hiroshima, Japan
3. Department of Gastroenterology & Hepatology, JA Hiroshima General Hospital, Hiroshima, Japan
4. Department of Gastroenterology, National Hospital Organization, Kure Medical Center and Chugoku Cancer Center, Kure, Hiroshima, Japan
5. Department of Gastroenterology, National Hospital Organization Higashihiroshima Medical Center, Higashihiroshima, Japan