[1] Natl Hosp Org Kanmon Med Ctr, Dept Clin Res, 1-1 Sotoura, Shimonoseki, Yamaguchi 7528510, Japan
[2] Shimane Univ, Dept Microbiol, Sch Med, Matsue, Shimane, Japan
[3] Natl Hosp Org Kanmon Med Ctr, Dept Gastroenterol & Hepatol, Yamaguchi, Japan
[4] Natl Hosp Org Kanmon Med Ctr, Dept Pathol, Yamaguchi, Japan
[5] Yamaguchi Univ, Grad Sch Med, Dept Lab Sci, Ube, Yamaguchi, Japan