[1] Hosp Clin 1 Prov, Barcelona, Spain
[2] Hop La Pitie Salpetriere, Paris, France
[3] Osped Maggiore Policlin, Milan, Italy
[4] Univ Miami, Miami, FL USA
[5] Univ Bern, Bern, Switzerland
[6] Univ Calgary, Heritage Med Res Clin, Calgary, AB, Canada
[7] Toronto Western Hosp, Univ Hlth Network, Toronto, ON M5T 2S8, Canada
[8] Charite Campus Virchow Klinikum, Berlin, Germany
[9] Hosp Med Sur, CIF BIOTEC, Mexico City, DF, Mexico
[10] Hosp Univ Gaffree & Guinle, Rio De Janeiro, Brazil
[11] Univ Klinikum Schleswig Holstein, Kiel, Germany
[12] St Josef Hosp, Oberhausen, Germany
[13] Hosp Municipal Gastroenterol Dr Bonorino Udaondo, Buenos Aires, DF, Argentina
[14] Schering Plough Res Inst, Kenilworth, NJ USA