[1] Yamaguchi Univ, Grad Sch Med, Dept Oncol & Lab Med, Dept Gastroenterol & Hepatol, Ube, Yamaguchi 755, Japan
[2] Yamaguchi Univ, Grad Sch Med, Dept Gastroenterol & Hepatol, Ube, Yamaguchi 755, Japan
[3] Univ Edinburgh, Queens Med Res Inst, Edinburgh, Midlothian, Scotland