Effect of 4‐N‐benzyldemethylrifampicin and of radiation therapy on rauscher viral leukemia in vivo

Abstract
Studies were carried out to evaluate the therapeutic effects of 4‐N‐Benzyldemethylrifampicin (AF/ABP) and of radiation on the survival of mice infected with Rauscher leukemia virus (RLV). To assess this effect two parameters were employed. These were (a) the percentage of animals surviving 6 months after infection, and (b) the average survival time of the animals which died. The results indicate that administration of the drug shortly after virus resulted in a marked increase in the number of survivors, but without any lengthening of survival time among the animals which died of the leukemia. Administration of the drug 14 days after virus had no beneficial effect on either survival time or number of survivors. The effect of radiation 14 days after virus infection significantly increased the survival time, but did not materially affect the ultimate number of survivors at 6 months after the virus infection. Combined employment of radiation and the drug 14 days after viral infection did not show any significant improvement over the use of radiation alone. Reduction of viral leukemia‐related splenomegaly was also noted following both radiation treatment and drug treatment. However, no significant correlation could be drawn between this reduction in splenomegaly and the survival time or the number of survivors.