1. Division of Gastroenterology and Hepatology, Graduate School of Medical and Dental Sciences, Niigata University, Chuo-Ku, Niigata 951-8510, Japan
2. Drug Discovery Laboratories, Chiome Bioscience Inc., 907 Nogawa, Miyamae-Ku, Kawasaki-Shi, Kanagawa 216-0001, Japan
3. Division of Gastroenterology and Hepatology, Niigata Prefectural Central Hospital, Joetsu-Shi, Niigata 943-0147, Japan
4. Division of Surgery, Niigata Prefectural Central Hospital, Joetsu-Shi, Niigata 943-0147, Japan
5. Division of Diagnostic Pathology, Niigata Prefectural Central Hospital, Joetsu-Shi, Niigata 943-0147, Japan
6. Division of Digestive and General Surgery, Graduate School of Medical and Dental Sciences, Niigata University, Chuo-Ku, Niigata 951-8510, Japan