[1] HARVARD UNIV, SCH MED, DEPT PEDIAT, BOSTON, MA 02115 USA
[2] CHILDRENS HOSP MED CTR, BOSTON, MA 02115 USA
[3] ORAVAX INC, CAMBRIDGE, MA 02139 USA
[4] BAYLOR UNIV, MED CTR, DEPT RADIOL, DALLAS, TX 75246 USA
[5] CHU VAUDOIS, DIV GASTROENTEROL, CH-1011 LAUSANNE, SWITZERLAND
[6] UNIV LAUSANNE, INST BIOCHEM, CH-1066 EPALINGES, SWITZERLAND
[7] UNIV LAUSANNE, SWISS INST EXPTL CANC RES, CH-1066 EPALINGES, SWITZERLAND