1. Division of Gastroenterology; Department of Internal Medicine; Kawasaki Medical School; Kurashiki Japan
2. Department of Gastroenterology and Metabolism; Graduate School of Biomedical Sciences; Hiroshima University; Hiroshima Japan
3. Department of General Medicine; Kawasaki Medical School; Kurashiki Japan
4. Division of Endoscopy and Ultrasound; Department of Clinical Pathology and Laboratory Medicine; Kawasaki Medical School; Kurashiki Japan
5. Health Service Center; Hiroshima University; Higashihiroshima Japan
6. Department of Internal Medicine; Saiseikai Hiroshima Hospital; Hiroshima Japan
7. Department of Pathology; Kawasaki Medical School; Kurashiki Japan
8. Department of Endoscopy; Hiroshima University Hospital; Hiroshima Japan
9. Department of Medicine; Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine; Houston TX USA