[1] Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Dept Gastroenterol & Hepatol, Okayama 7008558, Japan
[2] Sumitomo Besshi Hosp, Dept Internal Med, Niihama, Japan
[3] Sumitomo Besshi Hosp, Dept Pathol, Niihama, Japan
[4] Okayama Univ, Grad Sch Med Dent & Pharmaceut Sci, Dept Pathol, Okayama 7008558, Japan
[5] Okayama Univ Hosp, Dept Endoscopy, Okayama, Japan