[1] QUEENS UNIV,DEPT MED,KINGSTON K7L 3N6,ONTARIO,CANADA
[2] QUEENS UNIV,DEPT PHARMACOL & TOXICOL,KINGSTON K7L 3N6,ONTARIO,CANADA
[3] NCI,MOLEC CARCINOGENESIS LAB,BETHESDA,MD 20892
[4] NCI,FREDERICK CANC RES FACIL,DIV CANC ETIOL,COMPARAT CARCINOGENESIS,FREDERICK,MD 21701