1. Kyushu University Faculty of Medicine Graduate School of Medical Science, Department of Medicine and Bioregulatory Science, Fukuoka, Fukuoka, Japan
2. Kyushu University, Department of Endoscopic Diagnostics Therapeutics, Fukuoka, Fukuoka, Japan
3. Kyushu University Faculty of Medicine Graduate School of Medical Science, Department of Gastroenterology and Metabolism, Japan