THE EXPERTISE OF THE CAUSAL RELATIONSHIP BETWEEN THE DEVELOPMENT OF ARTERIAL HYPERTENSION WITH PARTICIPATION IN WORKS FOR LIQUIDATION OF THE CONSEQUENCES OF CHORNOBYL NPP ACCIDENT IN REMOTE POSTACCIDENTAL PERIOD. / EKSPERTYZA PRYChYNNOGO ZV'IaZKU ROZVYTKU ARTERIAL'NOÏ GIPERTENZIÏ Z UChASTIu V ROBOTAKh PO LIKVIDATsIÏ NASLIDKIV AVARIÏ NA ChORNOBYL'S'KII AES U VIDDALENOMU PISLIaAVARIINOMU PERIODI.

Loss of health and work ability, as well as deaths from diseases of the circulatory system (DCS), first of all arterialhypertension (AH), due to radiation exposure (RE) in the conditions of Chernobyl catastrophe (ChC) in the performance of professional, military or official duties and / or living on radiation-contaminated areas, additional exposurenot through their own fault but due to a radiation accident, caused the development of a special form of medicalexpertise as part of the of medical social protection system for these suffered contingents. OBJECTIVE: to optimize decision-making criteria for the expert estimation of the casual relationship between development and progression of AH under the influence of RE in clean-up workers of the Chornobyl NPP accident (CWs)in the remote postaccidental period based on the study of odds ratio (OR) of the course of the disease. MATERIAL AND METHODS: A retrospective analysis of the structure of 16073 cases of victims of the Chornobyl NPP(ChNPP) accident, considered by the Central Interagency Expert Commission of Ministry of Health of Ukraine for diseases, reason of disability and death causal relationship to ChNPP accident (CIEC) during 2014-2016, allowed toform a group of 401 cases of CW with AH to determine the OR of the course of the disease. The main group consisted of 330 CWs for whom the development of AH has a causal relationship with the participation in the work for liquidation consequences of the Chornobyl NPP accident (WLAc), the comparison group - 71 CWs in respect of whoma negative expert decision was made. There were not significant differences between both groups of CWs in doseof external radiation exposure (DERE) in the main group - (0.155 ± 0.085) Sv, in CWs of the comparison group -(0.135 ± 0.086) Sv (р = 0.868). RESULTS: In the remote postaccidental period, HSC take the second place (39.62 %) in the structure of medicalexpertise of the causal relationship of the diseases development and progression with RE for all categories of victims of the Chernobyl accident. The share of cases of AH was 28.4% of the total number of cases considered CWs. Inthe structure of cases of relationship of diseases of CWs that led to death, the share of AH was 17.8 %. In CWs themain group the AH developed in (9.4 ± 6.2) years after participation in WLAc, which is on average 6 years earlierthan in the comparison group (р < 0.001). AH in the main group of CWs developed at the age of 5.8 years youngerthan in the comparison group (р = 0.0005). The need for inpatient treatment come 8.6 years earlier (14.6 ± 7.7years) than in CWs comparison group (р < 0.001). At DERE 0,05 Sv and over, increases the probability of developmentand progression of AH that has causal relationship with participation in the WLAc. For medical expertise of thecausal relationship of the AH development and progression with WLAc at DERE 0.20 Sv and over the significant evidence value have the next criteria: terms Somatoform Vegetative (autonomic) Dysfunction (SVD) development(within 3,5 years) and its transformation into AH (within 7 years), verification of the AH diagnosis (within 9,5 years),inpatient treatment for SVD or AH (within 15 years), vascular events (Acute Cerebrovascular Accident - Stroke(ACVA) - within 24 years after participation in the WLAc or 11 years after the AH diagnosed, myocardial infarction(MI) - within 22 years after participation in the WLAc or 10.5 years after the AH diagnosed), the establishment ofpermanent disability. CONCLUSION: Radiation factor has an evidence influence on the development and progression of AH in CWs. Criteria ofthe development and progression of AH in CWs can be used for evidence-based medical expertise for estimation of thecausal relationship of the disease with the WLAc in the remote post accidental period at DERE more than 0.20 Sv.

Features of cellular effects of combined exposure to ionizing radiation and copper ions.

UNLABELLED: The constant increase in the scale of the use of chemicals and ionizing radiation in various industries, medicine and science increases their impact on all environmental components. Therefore, the probability of simultaneous effects of radiation and chemical factors on biological objects is growing. In this regard the issue of combined exposure to different by virtue of the nature factors is becoming more and more challenging. The objective of the work was to investigate the characteristics of the individual and combined effects of ionizing radiation and copper salts on cell viability in vitro. MATERIALS AND METHODS: The research involved inoculated cell culture line L929. Copper acetate (Cu(CH3COOH)2) was added to the cell culture 1 hour after irradiation. Irradiation of the cells was performed 24 hours after passaging. Proliferative activity of the cells was assessed by growth kinetics. Study results showed the cytotoxicity of copper ions at concentration of 1 µmol/L. A combined effect of ionizing radiation in sublethal doses and copper ions at a concentration of 0.001 and 1 µmol/L led to the increased number of atypical polykaryocytes. CONCLUSIONS: Both activation and inhibition of cell proliferation and mitotic activity occurs after the incubation of cells with copper ions at various concentrations. Cellular survival and mitotic activity decrease along with radiation dose elevation. Index of polykaryocytes at that is elevated. The altered morphological and functional properties of the cells were found in combined exposure to ionizing radiation and copper ions in vitro. They were not directly proportional either to a dose of irradiation or concentration of copper ions.

Features of cellular effects under combined effects of nickel ions and ionizing radiation.

UNLABELLED: Under current conditions the probability of simultaneous effects of radiation and chemical factors on biological objects increases, and that's why the issue of combined influence of factore different by their nature becomes progressively important. The objective was to study the cytotoxicity of nickel ions in a test-system of cell culture and to detect the cellular reactions under a combined impact of nickel ions and ionizing radiation. MATERIALS AND METHODS: Studies were performed on inoculated cell culture line L929. Cells were cultivated according to standard methods of treating the cell strains. After 24 h cultivation the cells were γ-irradiated at the unit "Teratron" (Canada) at doses of 0.5, 5.0 and 10.0 Gy. The water-soluble salt of nickel acetate was added to the culture medium 1 h prior to irradiation in the final concentration of 10, 1, 0.1, or 0.01 µmol/L. Morfological and functional characteristics of cells in a culture were determined at different periods of cultivation. Proliferative cell activity was assessed by growth kinetics: the total number of cells, the number of mitoses and giant multi (2 or more nuclei) cells were counted within grid area of 0.05 mm2. Simultaneously the number of apoptotic cells was determined. STUDY RESULTS: As a result , it was found that nickel ions exhibit the cytotoxic effects on cells in vitro: an increase in concentration of the element caused the cell death intencification with proliferative and mitotic activity decrease. Moreover, at low concentrations (0.01-0.1 µmol/L) the number of atypical polykaryocytes increased as well as the level of apoptosis. When nickel ions concentration increased the cell death took place through apoptosis and necrosis. Under the combined influence of radiation and nickel ions the nonlinear cellular responses were observed: under the low-dose radiation (0.5 Gy) a sensitization of cells to radiation was noted, and the sublethal doses (10 Gy) caused a particular radioprotection. Number of apoptotic cells under these conditions was significantly higher vs. control. CONCLUSIONS: Studies have shown that nickel ions have significant toxic effects on proliferation and mitotic activity of cells in vitro. Under the combined effects of ionizing radiation the cell sensitization to nickel ion was detected till following exposure to low dose (0.5 Gy) and reduction of cells tolerance to sublethal doses of irradiation (10 Gy).