[1] Chugoku Cent Hosp, Dept Gastroenterol, Fukuyama, Hiroshima, Japan
[2] Takanobashi Cent Hosp, Dept Gastroenterol, Hiroshima, Japan
[3] Hiroshima Red Cross Hosp, Dept Gastroenterol, Hiroshima, Japan
[4] Atomic Bomb Survivors Hosp, Hiroshima, Japan
[5] Okayama Univ, Dept Pathol, Grad Sch Med Dent & Pharmaceut Sci, Okayama, Japan