[1] Mayo Clin, Coll Med, Div Gastroenterol & Hepatol, Rochester, MN 55905 USA
[2] Mayo Clin, Ctr Canc, Rochester, MN 55905 USA
[3] Chulalongkorn Univ, Fac Med, Dept Med, Bangkok 10330, Thailand
[4] King Chulalongkorn Mem Hosp, Thai Red Cross Soc, Bangkok, Thailand