[1] Mayo Clin, Rochester, MN 55905 USA
[2] Univ Western Ontario, London, ON, Canada
[3] Univ Chicago, Chicago, IL 60637 USA
[4] Mt Sinai Sch Med, New York, NY USA
[5] Univ Calgary, Calgary, AB, Canada
[6] St Marks Hosp, London EC1V 2PS, England
[7] Atlanta Gastroenterol Associates, Atlanta, GA USA
[8] Univ Toronto, Toronto, ON, Canada
[9] Univ Nottingham Hosp, Nottingham NG7 2UH, England
[10] Univ Montreal, Montreal, PQ, Canada
[11] Univ Manitoba, Winnipeg, MB, Canada
[12] Celltech Therapeut Ltd, Slough, Berks, England
[13] Cedars Sinai Med Ctr, Los Angeles, CA 90048 USA