1. Digestive Endoscopy Center, Doshinkai Tohyama Hospital, Minami-shinmachi 17-22, Tsu, Mie 514-0043, Japan
2. Department of Immunology, Mie University Faculty and Graduate School of Medicine, Edobashi 2-174, Tsu, Mie 514-8507, Japan
3. Department of Internal Medicine, Doshinkai Tohyama Hospital, Minami-shinmachi 17-22, Tsu, Mie 514-0043, Japan
4. Digestive Center, Mie University Hospital, Edobashi 2-174, Tsu, Mie 514-8507, Japan