[1] Nagoya Univ, Sch Med, Dept Gastroenterol, Nagoya, Aichi 466, Japan
[2] Toyohashi Municipal Hosp, Dept Gastroenterol, Toyohashi, Aichi, Japan
[3] Fujita Hlth Univ, Dept Internal Med, Div Liver & Biliary Dis, Toyoake, Aichi, Japan
[4] Ogaki Municipal Hosp, Dept Gastroenterol, Gifu, Japan