CHANGES IN GENE EXPRESSION ASSOCIATED WITH NON-CANCER EFFECTS OF THE CHORNOBYL CLEAN-UP WORKERS IN THE REMOTE PERIOD AFTER EXPOSURE. / ZMINY GENNOÏ EKSPRESIÏ, ASOTsIIOVANI Z NEPUKhLYNNYMY EFEKTAMY VIDDALENOGO PERIODU PISLIa OPROMINENNIa V UChASNYKIV LIKVIDATsIÏ NASLIDKIV AVARIÏ NA ChAES.

OBJECTIVE: to establish the connection of radiation-induced changes in gene expression with the realized pathology of the broncho-pulmonary and cardiovascular systems in Chornobyl clean-up workers. MATERIALS AND METHODS: We examined 314 male Chornobyl clean-up workers (main group; age (58.94 ± 6.82) years(M ± SD); min 33, max 79 years; radiation dose (411.82 ± 625.41) mSv (M ± SD); min 1.74, max 3600 mSv) with various nosological forms of cardiovascular and broncho-pulmonary pathology (BPP) and 50 subjects of the controlgroup: age (50.50 ± 5.73) years (M ± SD); min 41, max 67 years. The relative level of BCL2, CDKN2A, CLSTN2, GSTM1,IFNG, IL1B, MCF2L, SERPINB9, STAT3, TERF1, TERF2, TERT, TNF, TP53, CCND1, CSF2, VEGFA genes expression was determined inperipheral blood leukocytes by real-time PCR (7900 HT Fast Real-Time PCR System (Applied Biosystems, USA)). The«gene-disease¼ association was determined on statistical models stratified separately for each disease and gene.Logistic regression was used to calculate the odds ratio. RESULTS: Increased GSTM1 gene expression and no changes in angiogenesis-related VEGFA gene expression werefound in the main group of patients with coronary heart disease (CHD). It was established overexpression of TP53,VEGF and IFNG genes in the group of patients with arterial hypertension (AH). At combination of these diseases anincrease of expression of СSF2, TERF1, TERF2 genes was established. The detected changes demonstrate an activationof the antioxidative defense system in patients with CHD, while AH is associated with the expression of genes ofangiogenesis and immune inflammation. It was shown an increase in the expression of genes associated with apoptosis and kinase activity (BCL2, CLSTN2, CDKN2), immune inflammation (CSF2, IL1B, TNF) in Chornobyl clean-upworkers with BPP. Expression of TP53 and GSTM1 (gene, associated with the glutathione system) was significantlyupregulated in the group of individuals with chronic bronchitis, whereas in patients with chronic obstructive pulmonary disease, no increase was detected; the expression of SERPINB9 and MCF2L genes was downregulated. CONCLUSIONS: Changes in the expression of genes, associated with the development of somatic pathology in theremote period after irradiation, in particular the genes of the immune response and inflammatory reactions CSF2,IFNG, IL1B, TNF; expression of genes that regulate cell proliferation, aging and apoptosis TP53, BCL2, MCF2L, CDKN2A,SERPINB9, TERF1, TERF2, TERT; genes that regulate cell adhesion and angiogenesis CLSTN2, VEGF.

BIOLOGICAL MARKERS OF EXTERNAL AND INTERNAL EXPOSURE IN SHELTER CONSTRUCTION WORKERS: A 13-YEAR EXPERIENCE.

OBJECTIVE: The aim of this study is to investigate the cellular, molecular, genetic and non-invasive functional biomarkers of occupational irradiation in workers exposed to a combination of external gamma-radiation and incorporation of transuranium elements. RESULTS: A study was performed in 688 radiation workers of Shelter object conversion into a safe system with mean shift dose of external exposure of 26.06 mSv (range: 0.1-113.35) and risk of internal exposure with transuranium elements. Several biological parameters could serve as biomarkers of exposure at radiation doses below 100 mSv and even in 20-50 mSv interval. The parallel changes were shown in decline of brain electric activity, telomere length, differences in CCND1, CDKN1A, CDKN2A, VEGFA, TP53, DDB2 genes expression. An increase in counts of dicentrics, pair fragments and TCR-variant lymphocytes at doses over professional limits shows the need of biological dosimetry. The most sensitive markers include TCR-CD4+, γ-H2AX+ and CyclinD1+ cell counts. Implementation of flow cytometry approach for these markers enables quick obtaining of quantitative data. Confounding factors included respiratory function and smoking. The study of the radiation workers with the history of chronic exposure in radiation area during 3-5 years demonstrates changes of compensatory origin, i.e. absence of telomere shortening, increased number of NK-cells in combination with lower expression of intracellular γ-H2AX. CONCLUSION: This study confirms the presence of radiation-induced changes in gene regulation of cell proliferation, telomere function and apoptosis in radiation workers exposed to external and internal exposure at doses above professional limits and increase of compensatory changes.

Cases of the staff unaccounted exposure during the construction of the protective shell for a new confinement at the ChNPP site. / VYPADKY NEVRAKhOVANOGO OPROMINENNIa PERSONALU PRY SPORUDZhENNI ZAKhYSNOGO KONTURU NOVOGO KONFAY̆NMENTU V ZONI DSP ChAES.

OBJECTIVE: cytogenetic control of the staff radiation exposure level during the construction of the protective shell for a new confinement at the ChNPP site. MATERIALS AND METHODS: A cytogenetic examination was carried out for 32 staff persons from the contracting organ izations involved into construction of the protective shell for a new confinement. Additionally, for the goal of com parison, 28 persons who did not have professional contacts with the radiation factors were inspected. The analyti cal method of the aberrations on preparations of uniformly stained chromosomes of the peripheral blood lympho cytes has been used. The frequency has been determined for the dicentrics and centric rings with an accompanying pair fragment for 100 analyzed metaphases. The staff chronic exposure absorbed doses are estimated by means of the linear part of the linear quadratic equations, which describe the calibration dose dependence of the unstable chromosomal exchanges yield in the acute irradiated blood samples in vitro. RESULTS: Six staff persons from 32 investigated ones have the individual frequency of the recent exposure specific markers (unstable chromosomal exchanges with accompanying pair fragments) significantly higher than those for the comparison group and the population average spontaneous level. It indicates on the possibility of their exces sive irradiation during the work execution in the ChNPP zone. Single cells with two chromosomal exchanges were registered for three persons, while such cells were absent in the comparison group. This is the result of the incorpo ration of radionuclides, which are available in the air at the workplaces. The calculated averaged individual absorbed doses caused by the recent exposure of six staff persons lies in the range from 102.5 to 371.0 mGy. CONCLUSION: The doses calculated from the frequency of unstable chromosomal exchanges with the accompanying pair fragment caused by the recent exposure of six staff persons are exceeding significantly the doses determined by the methods of physical dosimetry and the occupational exposure dose limits.

Cytogenetic indices in blood lymphocites of individuals from the staff working on new confinement buildining in Chornobyl NPP zone. / Cytogenetychni pokaznyky v limfocytah krovi grupy osib iz personalu, jakyj vykonuje roboty z budivnyctva novogo konfajnmentu v zoni ChAES.

Objective. Сytogenetic indication of possible exposure of contracting staff individuals, performing work on dismantling the ventilation pipe of "Shelter" object of Chornobyl NPP (ShO). Materials and methods. Cytogenetic examination of 12 individuals among the employees of contractors performing work on dismantling the ventilation pipe of ShO was provided. For comparison individuals who had no contact with the radiation factors for the profession activity were examined. Routine analysis method of uniformly stained chromosomes of peripheral blood lymphocytes was used. 11 388 metaphase plates were analyzed. Results. In contracting staff mean group frequency of aberrant lymphocytes, chromosome (dicentrics, acentrics, abnormal monocentrics) and chromatide type aberrations is significantly higher than such frequency in the comparison group. Three staff persons had individual frequency of specific markers of exposure - dicentric chromosomes with accompanying fragments significantly higher than their mean population level and the average frequency in the comparison group. It indicates the probability of their excess radiation when working in Chornobyl NPP local zone. Cells with two chromosome exchanges and one multiaberrant cell were registered in staff with the absence of such in control persons. The calculated estimated radiation doses of two staff persons were 87-123 mGy and and one person 210-240 mGy of acute exposure respectively. Conclusion. Calculated by frequency of dicentric chromosomes tentative "biological" doses of three staff persons show a more significant radiation effect comparing to the data of physical dosimetry.

Peculiarities of induction and persistence of hidden chromosome instability in peripheral blood lymphocytes of persons occupationally exposed to ionizing radiation. / Osoblyvosti indukcii' ta persystencii' pryhovanoi' hromosomnoi' nestabil''nosti v limfocytah peryferychnoi' krovi osib, jaki profesijno kontaktuvaly z ionizujuchoju radiacijeju.

Objective - to investigate the induction of hidden chromosome instability in persons occupationally exposed to ionizing radiation and its persistence in vitro in successive mitoses. Materials and methods. Using two tests ("G2-bleomycin sensitivity assay" and two-term cultivation of human peripheral blood lymphocytes) voluntary cytogenetic examination of 15 individuals participated in the conversion of the "Shelter" ("Chornobyl NPP") into ecologically safe system had been carried out. Total 24 034 metaphase had been analyzed, of which 12 243 - without additional mutagenic exposure, 11 791 - exposed to bleomycin in vitro at concentration of 0.05 µg/ml. Results. The magnitude and dynamics of background as well as bleomycin-induced cytogenetic effects in both terms of lymphocytes' cultivation in occupational group differed significantly from the group of comparison towards increasing of chromosome instability indices with significant interindividual fluctuations. Conclusion. Interindividual differences in persistence of radiation-induced hidden chromosome instability in successive generations of human somatic cells had been found.

Radiation protection and health of personnel of contracting enterprises participating in works for transformation of the object "shelter" of SSE Chornobyl NPP into an ecologically safe system.

UNLABELLED: Transformation of the object "Shelter" (OS) of SSE Chornobyl NPP into an ecologically safe system is one of the most important state programs in Ukraine. Both medical and dosimetric measures on healthcare of personnel participating in these works ranks the main place among most actual problems of contemporary clinical radiobiology, radiation hygiene, and radiation protection. The study objective was to work out and implement the medical and biophysical checking of the health status and workability both with radiation protection of personnel executing works on transformation of OS into an ecologically safe system. MATERIALS AND METHODS. The interdependent complex program of medical and biophysical (for internal and external irradiation) control of personnel executing the production tasks under conditions of ionizing radiation impact and open sources of ionizing radiation. Realization of medical examination envisages the estimation of the status of haemopoietic, immune, endocrine, respiratory systems, organ of vision, nervous system, psychics status and psychophysiological adaptation, ear, both with circulatory, digestive, urogenital, and bone-muscular system. There were 19434 cases of medical control of personnel in total. RESULTS: Results of the input medical control testify to the following: 4698 (48.90%) were admitted to work, 4909 (51.10%) were rejected. Individual annual effective doses of irradiation in the major part of cases did not exceed 12 mSv. There were 1845 cases of 239+240Pu content in excrements exceeding the level of 1.5 mBq/sample at a current biophysical control. Individual doses of internal irradiation at that did not exceed 1 mSv. CONCLUSIONS: The program of medical and biophysical service for reconstruction works on the OS proved its necessity and efficiency as its results showed that under the unique radiation-hygienical conditions not engineering challenges and technical problems but issues of how to save the health and workability of people and prevent the overdose of personnel including due to an internal irradiation are most critical.