The distribution of chromosome aberrations after gamma and neutron irradiation among cells in various stages of the mitotic cycle in a human lymphocyte culture

Distribution of chromosome aberrations among cells depending on radiation dose, stage of mitotic cycle of human lymphocyte culture, time of cell fixation under the effect of 6 MeV neutrons and their combination with postirradiation hyperthermia has been investigated. The regularities in the distribution of aberrations within cells are similar with both neutron- and gamma-radiation. In experiments with both types of radiation delivered at the S stage and fixation 52 h after the onset of incubation, distribution of aberrations follows Poisson formula whereas with 62-hour fixation, the correlation is disturbed. This is due to the presence of cells dividing for the second time after irradiation which makes the data obtained with delayed fixation scantily informative. Additional hyperthermia does not affect substantially the structure of cell population with both radiation types.