1. Department of Gastroenterology, Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan
2. Department of Gastroenterology, Onomichi General Hospital, Onomichi 722-8508, Japan
3. Department of Gastroenterology, Hiroshima Memorial Hospital, Hiroshima 730-0802, Japan
4. Department of Gastroenterology, Hiroshima Prefectural Hospital, Hiroshima 734-8530, Japan
5. Department of Gastroenterology, Hiroshima General Hospital, Hatsukaichi 738-8503, Japan
6. Department of Gastroenterology, National Hospital Organization Kure Medical Center and Chugoku Cancer Center, Kure 737-0023, Japan
7. Department of Gastroenterology, Saiseikai Hiroshima Hospital, Aki 731-4311, Japan
8. Department of Gastroenterology, Kure Kyosai Hospital, Kure 737-8508, Japan
9. Department of Gastroenterology, Saiseikai Kure Hospital, Kure 737-0921, Japan
10. Department of Gastroenterology, Hiroshima Red Cross & Atomic-Bomb Survivors Hospital, Hiroshima 730-8619, Japan
11. Department of Gastroenterology, National Hospital Organization Higashihiroshima Medical Center, Higashihiroshima 739-0041, Japan
12. Department of Gastroenterology, Hiroshima City North Medical Center Asa Citizens Hospital, Hiroshima 731-0293, Japan
13. Department of Gastroenterology, Chugoku Rosai Hospital, Kure 737-0193, Japan
14. Department of Anatomical Pathology, Hiroshima University Hospital, Hiroshima 734-8551, Japan