[1] STANFORD UNIV,MED CTR,SCH MED,DIV GASTROENTEROL,ROOM 5609,STANFORD,CA 94305
[2] CALIF DEPT HLTH SERV,VIRAL & RICKETTSIAL DIS LAB,BERKELEY,CA
[3] MEM SLOAN KETTERING CANC CTR,INFECT DIS SERV,NEW YORK,NY 10021
[4] JOHNS HOPKINS UNIV,SCH MED,DIV INFECT DIS,BALTIMORE,MD 21205
[5] ST LUKES ROOSEVELT HOSP,DIV GASTROINTESTINAL DIS,NEW YORK,NY 10025