[1] CABRINI MED CTR,NEW YORK,NY
[2] UNIV CALIF SAN DIEGO,DEPT MED GASTROENTEROL,LA JOLLA,CA 92093
[3] GEORGE WASHINGTON UNIV,MED CTR,DEPT MED,DIV GASTROENTEROL & NUTR,WASHINGTON,DC 20037
[4] UNIV MILAN,INST MED INTERNA,INTERNAL MED,I-20122 MILAN,ITALY
[5] UNIV PALERMO,CATTEDRA SEMEIOT MED,I-90134 PALERMO,ITALY
[6] HARVARD UNIV,MASSACHUSETTS GEN HOSP,SCH MED,DEPT RADIOL,BOSTON,MA 02114