[1] Alton Ochsner Med Fdn & Ochsner Clin, Gastroenterol Sect, New Orleans, LA 70121 USA
[2] Alton Ochsner Med Fdn & Ochsner Clin, Sect Pathol, New Orleans, LA 70121 USA
[3] Univ Pittsburgh, Med Ctr, Pittsburgh, PA USA
[4] Harvard Univ, Sch Med, Boston, MA USA
[5] Massachusetts Gen Hosp, Gastrointestinal Unit, Boston, MA 02114 USA
[6] Toronto Gen Hosp, Toronto, ON, Canada
[7] Univ Calif Los Angeles, Sch Med, Los Angeles, CA 90024 USA
[8] Univ Calif San Francisco, San Francisco, CA 94143 USA
[9] Univ Virginia, Hlth Sci Ctr, Charlottesville, VA USA
[10] Univ Miami, Miami, FL 33152 USA
[11] Calif Pacific Med Ctr, San Francisco, CA USA
[12] CHU Montreal, Montreal, PQ, Canada
[13] Glaxo Wellcome Inc, Res Triangle Pk, NC 27709 USA