[1] Kyoto Univ, Grad Sch Med, Dept Gastroenterol & Hepatol, Sakyo Ku, Kyoto 6068507, Japan
[2] Kobe City Gen Hosp, Dept Gastroenterol, Kobe, Hyogo, Japan
[3] Kobe City Gen Hosp, Dept Pathol, Kobe, Hyogo, Japan
[4] Kinki Univ, Sch Med, Dept Gastroenterol & Hepatol, Osaka 589, Japan