[1] Tohoku Univ Hosp, Dept Comprehens Med, Sendai, Miyagi 9808574, Japan
[2] Tohoku Univ, Grad Sch Med, Dept Surg, Sendai, Miyagi 980, Japan
[3] Saiseikai Kawaguchi Hosp, Dept Internal Med, Kawaguchi, Saitama, Japan
[4] Tokai Univ, Sch Med, Dept Gastroenterol, Isehara, Kanagawa 25911, Japan
[5] Sakura Life Clin, Tokyo, Japan
[6] Machida Municipal Hosp, Dept Surg, Machida, Tokyo, Japan
[7] Jikei Med Univ, Sch Med, Dept Surg, Minato Ku, Tokyo, Japan
[8] Gunma Univ, Grad Sch Med, Dept Med & Mol Sci, Maebashi, Gunma 371, Japan