[1] Shimane Univ, Sch Med, Dept Gastrointestinal Endoscopy, Izumo, Shimane 6938501, Japan
[2] Shimane Univ, Sch Med, Dept Gastroenterol & Hepatol, Izumo, Shimane 6938501, Japan
[3] Shimane Univ, Sch Med, Dept Clin Pathol, Izumo, Shimane 6938501, Japan