Damage susceptibility of human lymphocyte chromosomes at different stages of the mitotic cycle in combined exposure to fast neutrons and postradiation hyperthermia

The combined action of gamma rays (1-4 Gy) and postradiation hyperthermia on the human lymphocyte culture induces intensification of the damaging effect at the stage of DNA synthesis, i.e. at the most radioresistant stage of the mitotic cycle, the thermal intensification factor (TIF) being 1.7-2.0. After the neutron action (0.5-1.5 Gy) the hyperthermia has no effect on the chromosome aberration spectrum, the TIF being 1.8-2.5 at G1 phase and 1.8-2.4 at S phase, which testifies to the possible modification of neutron irradiation.