作者单位:Regents Univ, Augusta, GA USA[1]Univ Michigan, Ann Arbor, MI 48109 USA[2]Salix Pharmaceut, Raleigh, NC USA[3]Cedars Sinai Med Ctr, Los Angeles, CA 90048 USA[4]Washington Univ, Sch Med, Gastroenterol, St Louis, MO USA[5]Univ S Alabama, Mobile, AL 36688 USA[6]Beth Israel Deaconess Med Ctr, 330 Brookline Ave, Boston, MA 02215 USA[7]