1. Department of Gastroenterology, Osaka National Hospital, 2-1-14 Hoenzaka, Chuo-ku, Osaka 540-0006, Japan
2. Department of Gastroenterology and Hepatology, Osaka University Graduate School of Medicine, Clinical Research Building (K1), 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
3. Department of Gastroenterology, Osaka Police Hospital, Kitayama-cho, Tennoji-ku, Osaka 543-0035, Japan
4. Department of Gastroenterology, Sakai City Hospital, 1-1-1 Minamiyasui-cho, Sakai-ku, Sakai 590-0064, Japan
5. Department of Gastroenterology, Osaka Rosai Hospital, 1179-3, Nagasone-cho, Kita-ku, Sakai 591-8025, Japan
6. Department of Gastroenterology, Itami City Hospital, 1-100 Koyaike, Itami-shi, Hyougo 664-8540, Japan
7. Department of Gastroenterology, Osaka Kousei-Nenkin Hospital, 4-2-78 Fukushima, Fukushima-ku, Osaka 553-0003, Japan