Abstract: In delayed terms following Chernobyl accident the important role for realization of late medical consequences of human radiation exposure (including oncopathology) take place untargeted cytogenetic effects - hidden, delayed and transmissible chromosome instability and "bystander effect".
For investigation of these cytogenetic effects such models had been modified and applied by us: two-termed (during 48 and 144 hours) cultivation of peripheral blood lymphocytes; G2-bleomycin sensitivity assay; mixed human lymphocytes culture consisted of cells differed by cytogenetic sex markers. The groups of high priority with different intensity of radiation exposure due to Chernobyl accident had been voluntary observed.
In children born to exposed parents increased frequency of chromatid breaks in long-term cultures confirmed expression of delayed chromosome instability in consequent mitosis; appearance of stable aberrations confirmed transmissible chromosome instability.
In exposed groups investigated by means of G2-bleomycin sensitivity assay the individual levels of chromosome aberrations induced by testing concentrations of bleomycin varied in wide range and didn't depend on their initial values. Among control donors, liquidators and Shelter's personnel ~33% persons hypersensitive to bleomycin exposure had been identified that can be considered as genetically caused phenomenon. Among patients recovered from acute radiation sickness ~58% persons expressed hidden chromosome instability that assumed modification of inherited susceptibility to mutagens by high doses of ionizing radiation.
Under joint incubation of targeted lymphocytes received from Chernobyl liquidators with intact female lymphocytes the frequency of chromosome aberrations in bystander cells was significantly higher than their background level that proved induction of chromosome instability in untargeted cells as the result of bystander effect.
The data received confirmed the reality of untargeted cytogenetic effects in delayed terms following Chernobyl accident that can be one of risk factor for human health, especially for induction and promotion of oncopathology.

Brief Biography of the Speaker:
Maria A. Pilinskaya is Head of Cytogenetic’s laboratory of Department of medical genetics at Research Centre for radiation medicine, Ukraine. Her scientific interests are:
Assessment of mutagenic effects and genetic hazard of environmental factors for human health; biological indication and dosimetry of human radiation exposure; evaluation of nearest and delayed post Chernobyl cytogenetic effects in human; elaboration of cytogenetic criteria (especially cytogenetic oncomarkers) for the selection of risk groups. She is author or co-author over 350 scientific papers published in native and foreign reviewed journals or presented at domestic and international conferences. She is co-author of Russian-English Dictionary-Reference Book “Radiation Cytogenetics” (2009). She had the opportunity to work on probation in the field of FISH-WCP technique at Livermore National Laboratory, USA. She is a member of European Cytogenetisists Association.