1. Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka
2. Department of Gastroenterology, Fukuoka Higashi Medical Centre, Fukuoka
3. Department of Gastroenterology, Japan Organization of Occupational Health and Safety, Kyushu Rosai Hospital, Fukuoka
4. Digestive Diseases Branch, National Institutes of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
5. Department of Molecular Endocrinology and Metabolism, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan