[1] John Hopkins Hosp & Med Inst, Dept Med, Baltimore, MD USA
[2] John Hopkins Hosp & Med Inst, Div Gastroenterol & Hepatol, Baltimore, MD USA
[3] Showa Univ, Northern Yokohama Hosp, Yokohama, Kanagawa, Japan
[4] Winthrop Univ Hosp, Rock Hill, SC USA
[5] Northwestern Univ, Chicago, IL 60611 USA
[6] North Shore Univ Hlth Syst, Evanston, IL USA
[7] Fukuoka Univ, Fac Med, Fukuoka 81401, Japan
[8] Chinese Univ Hong Kong, Inst Digest Dis, Shatin, Hong Kong, Peoples R China