1 Department of Gastroenterology, Onomichi Municipal Hospital, 3-1170-177 Shintakayama, Onomichi 722-8503, Japan; Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan. Electronic address: iwamuromasaya@yahoo.co.jp.
2 Central Research Laboratory, Okayama University Medical School, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan.
3 Department of Gastroenterology, Onomichi Municipal Hospital, 3-1170-177 Shintakayama, Onomichi 722-8503, Japan.
4 Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan.
5 Department of Endoscopy, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan.