[1] UCL Royal Free & Univ Coll Med Sch, London, England
[2] Hop Hotel Dieu, Serv Gastroenterol, Paris, France
[3] Hop Hotel Dieu, Serv Anat Pathol, Paris, France
[4] Hop Lariboisiere, Serv Gastroenterol, F-75475 Paris, France
[5] Hop Lariboisiere, Serv Anat Pathol, F-75475 Paris, France
[6] Fdn Francaise Cancerol Digest, GELD, Dijon, France
[7] Inst Canc Res, Canc Gene Cloning Ctr, Sutton, Surrey, England
[8] Bacteriol Lab, Bordeaux, France