1. Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan;
2. Divisions of Gastroenterology, Matsuyama Red Cross Hospital, Ehime, Japan;
3. Division of Gastroenterology, Department of Internal Medicine, Iwate Medical University, Morioka, Japan;
4. Divisions of Pathology, Matsuyama Red Cross Hospital, Ehime, Japan;
5. Department of Endoscopic Diagnostic and Therapeutics, Saga University Hospital, Saga, Japan