[1] Okayama Univ Hosp, Dept Gastroenterol, Okayama, Japan
[2] Himeji Hosp, Japanese Red Cross Soc, Dept Internal Med, Himeji, Hyogo, Japan
[3] Okayama Saiseikai Gen Hosp, Dept Internal Med, Okayama, Japan
[4] Tsuyama Chuo Hosp, Dept Internal Med, Tsuyama, Japan
[5] Okayama Univ Hosp, Dept Pathol, Okayama, Japan
[6] Okayama Univ Hosp, Dept Gastroenterol Surg, Okayama, Japan