[1] INST CANC RES,CHESTER BEATTY LABS,VIROL GRP,LONDON SW3 6JB,ENGLAND
[2] CTR MED UNIV GENEVA,DEPT BIOCHIM MED,CH-1211 GENEVA 4,SWITZERLAND
[3] GRYPHON SCI,S SAN FRANCISCO,CA 94080
[4] RIGSHOSP 6321,MOL PHARMACOL LAB,DK-2100 COPENHAGEN,DENMARK
[5] GLAXOWELLCOME RES & DEV SA,GENEVA BIOMED RES INST,CH-1228 PLAN LES OUATES,GENEVA,SWITZERLAND