[1] Kansai Med Univ, Div Gastroenterol & Hepatol, Dept Internal Med 3, Hirakata, Osaka 5731191, Japan
[2] Shinshu Univ, Ctr Hlth Safety & Environm Management, Matsumoto, Nagano, Japan
[3] Tokyo Metropolitan Komagome Hosp, Tokyo, Japan
[4] Nagoya Univ, Grad Sch Med, Dept Gastroenterol, Nagoya, Aichi, Japan
[5] Showa Univ, Sch Med, Dept Internal Med 2, Tokyo 142, Japan
[6] Kochi Med Sch, Dept Gastroenterol & Hepatol, Nankoku, Kochi, Japan
[7] Nagoya City Univ, Grad Sch Med Sci, Dept Internal Med & Bioregulat, Nagoya, Aichi, Japan
[8] Kyushu Univ, Grad Sch Med Sci, Dept Med & Bioregulatory Sci, Fukuoka 812, Japan
[9] Ogaki Municipal Hosp, Dept Gastroenterol, Ogaki, Japan
[10] Fujita Hlth Univ, Teaching Hosp 2, Dept Internal Med, Nagoya, Aichi, Japan
[11] Tohoku Univ, Grad Sch Med, Div Gastroenterol, Sendai, Miyagi, Japan
[12] Kurihara Cent Hosp, Kurihard, Japan
[13] Juntendo Univ, Sch Med, Dept Pathol, Tokyo 113, Japan
[14] Tokyo Womens Med Univ, Sch Med, Dept Gastroenterol, Tokyo, Japan
[15] Kyushu Univ, Grad Sch Med Sci, Dept Surg & Oncol, Fukuoka 812, Japan
[16] Chiba Univ, Grad Sch Med, Dept Med & Clin Oncol, Chiba, Japan
[17] Kyorin Univ, Sch Med, Dept Surg, Tokyo, Japan
[18] Univ Occupat & Environm Hlth, Japan Sch Med, Dept Internal Med 3, Kokura, Japan