1. Health Care Center, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
2. Clinical Research Center, Kyushu Medical Center, National Hospital Organization, Fukuoka 810-8563, Japan
3. Department of Gastroenterology, Kyushu Medical Center, National Hospital Organization, Fukuoka 810-8563, Japan