[1] Hiroshima Univ Hosp, Dept Endoscopy, Minami Ku, Hiroshima 7348551, Japan
[2] Hiroshima Univ, Dept Med & Mol Sci, Grad Sch Biomed Sci, Minami Ku, Hiroshima 7348551, Japan
[3] Hiroshima Univ, Hlth Serv Ctr, Higashihiroshima 7398514, Japan
[4] Hiroshima Univ Hosp, Dept Pathol, Minami Ku, Hiroshima 7348551, Japan