in 1984 , tofilon and deen reported that x irradiation of 9l cells immediately after treatment with 1,3-bis ( 2-chloroethyl ) -1-nitrosourea ( bcnu ) produced greater than additive induction of sister chromatid exchanges ( sces ) compared to the sum of sces induced by each agent alone [ radiat . res . 97 , 171-177 ( 1984 ) ] .
C0007634
cells
C0037211
sces