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High doses of ionizing radiation clearly produce deleterious consequences in humans, including, but not exclusively, cancer induction. At very low radiation doses the situation is much less clear, but the risks of low-dose radiation are of societal importance in relation to issues as varied as screening tests for cancer, the future of nuclear power,(More)
This paper develops a deterministic model of frequency distributions for energy imparted (total energy deposition) in small volumes similar to DNA molecules from high-energy ions of interest for space radiation protection and cancer therapy. Frequency distributions for energy imparted are useful for considering radiation quality and for modeling biological(More)
General correlations are found between the detailed spatial and temporal nature of the initial physical features of radiation insult and the likelihood of final biological consequences. These persist despite the chain of physical, chemical and biological processes that eliminate the vast majority of the early damage. Details of the initial conditions should(More)
Complex chromosome aberrations are characteristically induced after exposure to low doses of densely ionizing radiation, but little is understood about their formation. To address this issue, we irradiated human peripheral blood lymphocytes in vitro with 0.5 Gy densely ionizing alpha-particles (mean of 1 alpha-particle/cell) and analyzed the chromosome(More)
Modelling and calculations are presented as a first step towards mechanistic interpretation and prediction of radiation effects based on the spectrum of initial DNA damage produced by low energy electrons (100 eV-4.5 keV) that can be compared with experimental information. Relative yields of single and clustered strand breaks are presented in terms of(More)
PURPOSE To determine the induction and transmission, to second and third division cells, of complex chromosome aberrations in peripheral blood lymphocytes after exposure to high-LET alpha-particles in vitro. MATERIALS AND METHODS Separated peripheral blood lymphocytes collected from four healthy donors were irradiated in vitro with either high-LET(More)
This paper presents data on modelling of DNA damage induced by electrons, protons and alpha-particles to provide an insight into factors which determine the biological effectiveness of radiations of high and low linear energy transfer (LET). These data include the yield of single- and double-strand breaks (ssb, dsb) and base damage in a cellular(More)
PURPOSE To investigate the role of kinetics in the processing of DNA double strand breaks (DSB), and the formation of simple chromosome exchange aberrations following X-ray exposures to mammalian cells based on an enzymatic approach. METHODS Using computer simulations based on a biochemical approach, rate-equations that describe the processing of DSB(More)
When investigating the biological effects of ionizing radiation on the haemopoietic system, a confounding problem lies in possible differences between the biological effects of sparsely ionizing, low linear energy transfer radiation such as X-, beta- or gamma-rays, and densely ionizing, high linear energy transfer radiation such as alpha-particles. To(More)
We have demonstrated chromosomal instability in the clonal descendants of hemopoietic stem cells after irradiating murine bone marrow with alpha-particles. However, because cells that are irradiated by alpha-particles are defined by a Poisson distribution of individual particle traversals, there is an inevitable proportion of unirradiated cells in the(More)