[1] Yokohama City Univ, Grad Sch Med, Dept Gastroenterol, Yokohama, Kanagawa 232, Japan
[2] Yokohama City Univ, Grad Sch Med, Dept Biostat & Epidemiol, Yokohama, Kanagawa 232, Japan
[3] Hiroshima Univ, Grad Sch Biomed Sci, Dept Med & Mol Sci, Hiroshima, Japan
[4] Kyoto Prefectural Univ Med, Dept Gastroenterol & Hepatol, Kamigyo Ku, Kyoto, Japan
[5] Kochi Med Sch, Dept Gastroenterol & Hepatol, Kochi, Japan
[6] Saga Med Sch, Div Hepatol, Ctr Liver, Saga, Japan
[7] Yokohama City Univ, Grad Sch Med, Dept Radiol, Yokohama, Kanagawa 232, Japan
[8] Shimane Univ, Fac Med, Dept Pharmacol, Izumo, Shimane, Japan