The significance of cytogenetic investigation for the estimation of Chernobyl accident consequences

The results of the cytogenetic investigation of people, which were exposed to radiation in the result of the Chernobyl NPP accident, were presented. Also the possibilities of the application of cytogenetic findings for dose estimations and for the prediction of the radiation influence consequences were examined. During the period of time since 1986 till 2004 the cytogenetic investigations of 1724 liquidators participating in the liquidation works after the Chernobyl accident were carried out. The radiation dose estimated by the frequency of dicentrics in 1986 was about 0.16 Gy. The doses for liquidators were determined by the frequency of translocations (FISH method) during the period from 1992 till 1995. For liquidators who worked in Chernobyl only in 1986 the average dose of radiation was about 0.19 Gy and for liquidators who worked repeatedly during the period from 1986 till 1995 - 0.39 Gy. There was shown that during the whole period of investigation (1986-2004) the frequency of dicentrics in peripheral blood lymphocytes was significantly higher than the control level. The cytogenetic investigation of Bryansk region inhabitants which was carried out in 1992-1994 discovered heightened value in 5 times than the control one. Findings are of great importance for the prediction of ill effects of radiation and for the development of sensitive criterions for early exposure disturbances in state of health.     

The epidemiological analysis of monitoring of the immune status in liquidators of consequences of the Chernobyl accident for early identification of risk groups and diagnostics of oncological diseases. Report 1

Ionizing radiation is one of major factors of risk of oncological diseases. A question about the frequency of malignant neoplasms (MN) and their early identification in the liquidators of consequences of the Chernobyl accident remains opened. In the present work, the results of long-term immunological monitoring of the liquidators of consequences of the failure at the Chernobyl Nuclear Power Plant (ChN PP) living in the Northwest region of Russia are analyzed; we also heve made an attempt to reveal the predictors of oncological diseases in this group of individuals. The frequency of the newly revealed MN cases in a cohort of the persons who took part in liquidation of consequences of the ChNPP failure and were followed-up in 1999-2009, has made up 89 cases per 1005 persons (8.856%), which somewhat exceeds general population indicators. Regarding the frequency of separate MN localizations, lung cancer, cancer of stomach and cancer of prostate gland predominated, which corresponds to the world's tendency of MN prevalence. It has been established that as early as 1-3 years before diagnosis of MN is confirmed in liquidators, a number of changes in the immune status comes to light: drop in percentage of CD3+ and CD4(+)-T-lymphocytes, B-lymphocytes to a lesser extent, decrease in the CD4+/CD8+ index, increase of the relative and absolute content of CD16(+)-lymphocytes, increase of absolute content of CD8(+)-T-lymphocytes, prevalence of CD3+16/56+(NK-T) cell over CD3-16/56+(NK) cells, rise of the activity of phagocytes. Patients with the presence of one or several of the above-mentioned signs should be attributed to the MN risk group for determination of tumor markers, thorough examination and dynamic observation.     

Elevated frequencies of hypoxanthine phosphoribosyltransferase lymphocyte mutants are detected in Russian liquidators 6 to 10 years after exposure to radiation from the Chernobyl nuclear power plant accident

This study was conducted to determine whether the frequency of hypoxanthine phosphoribosyltransferase (HPRT) deficient lymphocyte mutants would detect an effect of radiation exposure in a population of Russians who were exposed to low levels of radiation while working in 1986 and 1987 as liquidators cleaning up after the Chernobyl nuclear power reactor accident. The HPRT lymphocyte cloning assay was performed on peripheral blood lymphocytes collected between 1992 and 1996 from 142 liquidators and 66 Russian controls, and between 1989 and 1993 from 231 American controls. Russian and American controls were not significantly different for either cloning efficiency or mutant frequency (MF); inclusion of both sets of controls in the analysis increased the ability to detect a Chernobyl exposure effect in the liquidators. After adjusting for age and smoking, the results revealed no significant difference in cloning efficiency of Chernobyl liquidators relative to Russian controls but a significant, 24% increase in liquidator HPRT mutant frequency over Russian controls (90% confidence interval was 7% to 45% increase). The analytical method also accounted for differences in precision of the individual estimates of log CE and log MF and accommodated for outliers. The increase in HPRT mutant frequency of liquidators is an attribute of the exposed population as a whole rather than of individuals. These results demonstrate that, under appropriate circumstances, the HPRT specific locus mutation assay of peripheral blood lymphocytes can be used to detect a semi-acute, low dose radiation exposure of a population, even 6 to 10 years after the exposure.     

An epidemiological analysis of monitoring of the immune status of chernobyl nuclear accident liquidators for early detection of risk groups and diagnosis of cancer diseases. Communication 1

Ionizing radiation is one of the major risk factors for cancer diseases. The question on the rate of malignant neoplasms (MNs) and their early detection in Chernobyl nuclear accident (ChNA) liquidators is still open. In this work, the results of a long-term immunological monitoring of the ChNA liquidators who live in the northwestern region of Russia have been analyzed with an attempt to detect the predictors of cancer in this population cohort. The rate of newly detected MN cases in the cohort of followup ChNA liquidators monitored in 1990–2009 was 8.856% (89 cases per 1005 persons), which is somewhat higher as compared with the average rate for the total population. As for the rate of individual MN types, lung, gastric, and prostate cancers were prevalent, which matches the worldwide trend in MN abundance. It was shown that 1-3 years before the MN diagnosis, liquidators displayed detectable changes in their immune status, including a decrease in the percentages of CD3⁺ and CD4⁺ T lymphocytes, and, to a lesser degree, B lymphocytes; a decrease in the CD4⁺/CD8⁺ ratio; increase in the relative and absolute contents of CD16⁺ lymphocytes; increase in the absolute CD8⁺ T lymphocyte counts; prevalence of CD3⁺16/56⁺ (NK-T) cells over CD3-16/56⁺ (NK) cells; and increase in the activity of phagocytes. The patients who displayed one or several of the listed characteristics should be ascribed to the MN risk group to be assessed for cancer markers, be more comprehensively examined, and be the subjects of dynamic observation.     

Genetic effects in the liquidators of consequences of Chernobyl Nuclear Power Plant accident

The purpose of the present research was the estimation of probable genetic consequences at the liquidators of the consequences of Chernobyl accident in 1986-1987. The research is made on two groups of the liquidators. The first group included the liquidators taking place on the account in the branch register and working now at the enterprises of a nuclear industry. The second group included 902 liquidators of consequences of Chernobyl accident in 1986 constantly living in the Ryazan area and which are taking place on permanent observation the account in regional hospital. For an estimation of probable genetic effects analyzed the data on frequency and outcomes pregnancy of the wives of the liquidators, on condition and on diseases of newborn, on switching intrauterine development defects (IDD). The analysis carried out depending on dozes of an irradiation: up to 5 cGy; 5-10 cGy and 10-25 cGy. Received materials testify, that at the liquidators, at a doze of an external irradiation 10-25 cGy, the determined effects--period long sterility, kept at a part them till 3 years come to light. The set of the received data, such as depending from the dose increase of frequency of spontaneous abortions and of inherent defects of development of newborn, the increase of frequency diseases of newborn and share newborn with low weight, allows to make a conclusion about an induction of genetic effects in sexual cells of the liquidators of consequences of Chernobyl accident at dozes of an external irradiation more than 10 cGy. Taking into account high biological efficiency of alpha-radiation (K = 20), and of beta-radiation (K = 2-4), the equivalent effective doze male gonads (testes) in 3-5 times is higher, than estimated only from external gamma-radiation.     

FISH analysis in verification of recorded doses in liquidators of Chernobyl accident

With the help of the FISH technique the Official Dose Records (ODR) in 40 liquidators from the National (18 persons) and Military (22 persons) Registers were verified. In the civil liquidators the cases with the overestimated individual ODR were predominated while in the liquidators from the Military Register the cases with underestimation of the ODR in comparison with biological irradiation doses were prevailed. The both groups were considered as true "high-dose" ones with radiation exposure that exceed permissible levels for an accident.     

The number of nucleoli in peripheral blood lymphocytes of the Chernobyl accident liquidators]

The number of nucleoli in lymphocyte nuclei was compared in the peripheral blood of the Chernobyl liquidators and non-irradiated persons (control). The former was significantly distinguished from the latter (p < 0.01) by the parameter "the number of nucleoli in lymphocytes", mean numbers of nucleoli per nucleus in these being 1.18 and 1.12, respectively. The increased number of nucleoli in lymphocytes of the Chernobyl liquidators may be associated with cytogenetic radiation effects.     

Delayed medical consequences of the Chernobyl accident in Armenia. Assessment of life quality and accelerated biological aging of accident liquidators

In this paper, some final results of 25-year investigations carried out in Scientific Centre for Radiation Medicine and Burns MH RA (SCRMB) on the Armenian cohort of the Chernobyl accident consequences liquidators are shown. These results show that health conditions of the liquidators became worse during the whole observation period. A considerable development of both pathological states atypical of radiation damages and diseases, which may be considered as radiation-induced ones, was determined. Rise of the sickness rate of almost all organism systems, first of all, nervous, cardiovascular, respiratory and digestive ones, was observed. In 70% of liquidators the main disease was primarily detected after working on CNPP. In the intervening years, the average number of diagnoses per 1 liquidator increased from 1.5 in 1987 to 7-8 in the recent time. In addition to the detected diseases, particular functional shifts in neuropsychological and vegetative status of the liquidators were observed. The overwhelming majority of them have increased tonicity of the sympathetic vegetative nervous system, asthenic and depressive syndromes occurring in the form of weakness, somnolence, mood instability, mental capacity decrease, and memory defects. In the paper, the results of investigations aimed at clarification of changes in biological aging processes of the liquidators and assessment of their "life quality" features in terms of physical, psychical and social welfare are considered. Biological aged-related passportization in a definite part of liquidators elucidated an accelerated aging rate. The studies were performed with the help of SF-36 inquirer and indicated that health status aggravation of the liquidators also affected their life satisfaction. The "life quality" indices of the liquidators significantly concede the overall average standards by both physical health and psychical and social welfare scales.     

Thyroid cancer incidence among Chernobyl emergency workers: follow-up period 1986-2003

A vast amount of research articles devoted to the increase in childhood thyroid cancer incidence in the most contaminated by radionuclides territories of Belarus, Russia and Ukraine affected by the Chernobyl accident were published recent years. However, the amount of research studies of thyroid cancer incidence among the Chernobyl emergency workers (liquidators) is quite scanty. In the article results of the study of thyroid cancer incidence in the cohort of the Chernobyl liquidators (103427 persons) residing in 6 administrative regions of Russia (North-West, Volgo-Vyatsky, Central-Chernozemny, Povolzhsky, North-Caucasus and Urals) are described and discussed. For the period 1986-2003 eighty seven cases of thyroid cancer were detected in the cohort. Statistically significant excess of the incidence among liquidators over baseline incidence, SIR = 3.39 (95% CI: 2.73; 4.16), among men of Russia has been found. The highest thyroid cancer incidence (SIR = 6.49) was registered among liquidators who had been involved in mitigation works during April-July 1986. At the same time no statistically significant relationship between the incidence rate and external radiation dose, ERR = 1.68 (95% CI: -0.95; 6.46), was detected.     

The radiation risks of cerebrovascular diseases among the liquidators

The work concerns the assessment of radiation risks for non-cancer diseases of circulatory system among the Chernobyl liquidators. The medical and dosimetric data from Russian National Medical and Dosimetric Registry were used. The cohort data from 1986 to 2000 years of 61017 liquidators are discussed. Radiation risks are established for the cerebrovascular diseases and for the essential hypertension the significant. ERR =0.45/Gy, with 95% CI = (0.11; 0.80) for the cerebrovascular diseases and ERR = 0.36/Gy, with 95% CI = (0.005; 0.71) for the essential hypertension. It approves the results which were established by authors for the similar cohort in 1986-1996. The cerebrovascular diseases (CVD) are considered in greater details. The significant heterogeneity of the radiation risks by working time in Chernobyl zone is shown for the first time. ERR = 0.89/Gy for the working time less then 6 weeks, and ERR = 0.39/Gy in average for all periods of working in the zone. Among the liquidators entered Chernobyl zone during the first year after the accident (29003 liquidators), the CVD's risk group consists of persons accumulated more then 150 mGy from external sources in less, then 6 weeks (RR = 1.18 with 95% CI = (1.00; 1.40)). The significant CVD's risk from averaged dose rate was defined for external doses greater then 150 mGy (ERR for 100 mGy/day = 2.17, with 95% CI = (0.64; 3.69)).     

The connection between molecular-cellular parameters and immune status of liquidators after Chernobyl accident

The genome damage (the frequencies of cells with micronuclei (MN), chromosome aberrations, the level of DNA double-strand breaks (DSB DNA), the concentration of reactive oxygen species (ROS) and 28 immunological parameters have been studied on the blood lymphocytes of Chernobyl accident liquidators. The purpose of this article was the investigation of cytogenetic, molecular changes of blood lymphocytes of irradiated individuals 24 years after accident, examination it there are correlation between genome damage and immunological parameters. It was shown that in lymphocytes of liquidators the frequencies of cells with MN and with all type of chromosome aberrations didn't differ from the lymphocytes of nonirradiated individuals, but the frequency of chromosome aberration type was increased, the level of DSB DNA was increased too. The concentration of ROS is decreased. The percent of cytotoxic CD8(+)-T-lymphocytes, natural killer cells (CD16(+)-lymphocytes), CD3+ CD16+ CD56+ (NK-T-cells), that posses antivirus and antitumor activity--HLA-DR+, regulatory T-lymphocytes (CD4+ CD25+high) in liquidators significantly increases. The level of serum immunoglobulin (Ig A) significantly increases too. The index of immune regulation, meaning of phagocyte neutrophil (FAN) and macrophage activity decreases. In liquidators there are significant correlation between the frequencies of cells with MN and the content of regulatory T-lymphocytes (p < 0.05), between the concentrations of ROS and activated T-lymphocytes. More connection is on the tendency level (p < 0.10): the frequency of chromosome aberrations, the DSB DNA level with natural killer cells and regulatory T-lymphocytes; the frequency of cells with MN and DSB DNA and FAM. We can suppose that genomic instability induced by the liquidators of Chernobyl accident consequences 24 years ago manifests now as increased genome damage and oxidative status decrease that can result in imbalance of cells and humoral immune status, disturbancies of health.     

The epidemiological analysis of monitoring of the immune status in liquidators of consequences of the Chernobyl accident for early identification of risk groups and diagnostics of oncological diseases. Report 2. Dependence of frequency and changes in the immune status on risk factors of radiation accident

Malignant neoplasms (MN) have been found to develop most frequently in the liquidators of entry into the ChNPP zones in 1986 (43.75%), as well as among the liquidators who worked for long, one quarter of whom participated in liquidation of the consequences of failure (LCF) in 1986. Specific features of the immune status depending on the timing of participation in LCF and the year of entry into the ChN PP zone have been established. Changes in the immune system in the persons with a confirmed diagnosis of MN who took both a non-permanent and permanent part in liquidating the consequences of the ChNPP failure in 1986 had the same character of deviations and differed in the magnitudes of deviations of immunological parameters. Continuous participation in the period of extreme conditions and a greater exposure to the radiation factor led to the increased content of CD8(+)-T-cells, CD16(+)-lymphocytes and activated T-lymphocytes, as well as to the reduced index of immune regulation, decreased content ofCD3-16/56+(NK)-cells (%) and the total IgE and to a greater deficiency of B-lymphocytes. Distinctions in the groups of liquidators who participated in LCF in 1986 and 1987 have been revealed. The greatest deviations in the IS indicators were found in liquidators-87. A similar effect came to light in case of a continuance in the ChNPP zones in 1986 and 1987; however, the degree of deviation of the content of CD4(+)-T-lymphocytes (41), CD8(+)-T-lymphocytes (1) and the immune regulation index (41) were remarkably higher in liquidators-87. A continuous stay in the ChNPP zones in 1987 led to the deficiency of CD4(+)-T-lymphocytes, increased values of CD8(+)-T-lymphocytes, a decreased index of CD4+/CD8+, as well as to the change in the ratio between NK-T and NK cells, increased numbers of CD95+, HLA-DR+ and activated T-lymphocytes, and a lower level of the total IgE. Long-term participation in LCF didn't cause any enhanced expression of cellular activation markers in liquidators-86. Specific features of changes in IS depending on a dose of external gamma-irradiation have been established. Increase in the frequency of MN among liquidators, in relation to the number of examinees in each age group, with age has been revealed. Distinctions in the age dynamics of IS in liquidators in the presence and in the absence of MN manifested themselves in a stable level of values of CD3+, CD4+, CD8(+)-T-lymphocytes, immune regulation index, CD95+, serum IgA at the age between 40 and 70 years old with a subsequent reduction in indicators and increase in the content of CD8(+)-T-lymphocytes with age in the absence of MN; continuous increase of CD3-16/56(+)-NK-cells in the presence of MN and decrease in the values after 70 in the absence of MN. Also revealed in IS of the both age groups of liquidators over 70 with and without MN was the deficiency of the T-cell component (CD3+, CD4(+)-T-lymphocytes, CD4+/CD8+ index) and the increase in absolute values of CD8(+)-T-lymphocytes. The growing deficiency of CD4(+)-T-lymphocytes during monitoring against the background of ever rising values of CD8(+)-T-lymphocytes leading to the weakening of the immune regulation due to progressing disorders of the T-lymphocyte regulatory subpopulation distribution can serve an indicator for the adverse prognosis of the life expectancy in the presence of MN.     

The molecular and cellular consequences of the chernobyl accident

In this paper the results of research at 5–10 and 24 years after the Chernobyl accident are summarized. These results include the investigation of genomic instability, formation of the adaptive response, genome damage, and oxidative status. The studies were performed on cells in culture, mice, children and adults who lived in the contaminated areas, and liquidators of the consequences of the Chernobyl accident. Inhibition of cell proliferative activity, late cell death, and the increase in micronucleus and giant cell frequency were observed after the exposure of cells in culture in the accident zone followed by their culturing in laboratory conditions. In the progeny of the exposed cells, the effect of enhanced radiosensitivity was detected. Thus, it can be assumed that exposure of parental cells in culture in the area of the accident induced genomic instability that resulted in the development of various abnormalities in progeny cells. At the organism level, the Chernobyl zone exposure of mice caused an increase in radiosensitivity; as well, a decrease in the endotheliocyte density in the cerebral cortex and other brain tissues was observed. In the blood lymphocytes of children stimulated by PHA, a more than two times increase in micronucleus cell frequency was detected. A reduced number of individuals with significant adaptive response was found in both the juvenile and adult groups. In all investigated populations, an increased number of individuals with enhanced radiosensitivity were observed in response to low-dose radiation exposure. At 24 years after the accident liquidators were subjected to examinations, which revealed an increased frequency of cells with micronuclei and chromosome-type aberrations in blood lymphocytes, an elevated level of DNA double strand breaks, and a reduced level of reactive oxygen species compared to those of the control group. This means that the genomic instability that was accumulated by the residents of the contaminated regions and liquidators as a result of the accident leads to damage of the genetic apparatus, an increase in radiosensitivity, and hypoxia as late consequences that all are risk factors and increase the probability of the development of tumor and non-tumor diseases. The development of the above-mentioned pathological processes may occur in the distant future.

     

Medical protection during radiation accidents: some results and lessons of the Chernobyl accident

Actions of medical radiation protection of liquidators of consequences of on Chernobyl atomic power station accident are analysed. It is shown, that during the early period of the accident medical protection of liquidators was provided by administration of radioprotectors, means of prophylaxis: of radioactive iodine incorporation and agent for preventing psychological and emotional stress. When carrying out decontamination and regenerative works, preparations which action is caused by increase of nonspecific resistance of an organism were applied. The lessons taken from the results of the Chernobyl accident, have allowed one to improve the system of medical protection and to introduce in practice new highly effective radioprotective agents.     

Comparative results of thyroid ultrasound and laboratory studies in patients exposed to radiation

The paper presents the data of thyroid ultrasound and laboratory studies in 233 persons exposed to radiation: 63 X-ray physicians, 36 Chernobyl accident liquidators, 31 patients with lymphogranulomatosis, receiving radiotherapy, and 103 individuals (a control group) who were physicians of various specialties whose professional activity is unassociated with radiation factors. Thyroid changes were found in 67.7% of the examinees after gamma teletherapy and in 31% in the control group; among X-rat physicians and Chernobyl accident liquidators, the occurrence of thyroid changes was equal--44.4%. Direct radiation exposure of the thyroid in a dose of above 30 Gy led to the development of postradiation fibrosis (22.5%) and postradiation thyroiditis (32.3%) with thyroid dysfunction that is most commonly presented by hypothyroidism (22.45%). Autoimmune thyroiditis (11.1%) more predominantly with subclinical hypothyroidism, and diffuse thyroid hyperplasia (19.4%) resulted from mixed internal and external radiation. Thyroid changes revealed in X-ray physicians mainly appeared as nodular masses (22.2%) without functional impairments but to be followed up. It is recommended that the annual preventive examination protocol be supplemented by thyroid ultrasound studies in X-ray physicians.     

Microsatellite mutations show no increases in the children of the Chernobyl liquidators

We performed a study on Belarusian "liquidators", exploring whether increase in the frequencies of germline mutations at microsatellite loci could be found in their progeny. The liquidators, mostly young males, were those involved (during 1986 and 1987) in clean-up operations in the radioactively contaminated area following the Chernobyl nuclear power plant accident in 1986. Many liquidators fathered children during the clean-up period and after the work had been terminated. The numbers of families studied were 64 (liquidators) and 66 (controls). A total of 72 loci (31 autosomal, one X-linked and 40 Y-linked) were used. DNA was isolated from peripheral blood lymphocytes and the microsatellite loci were amplified by the polymerase chain reaction with fluorescence-labelled primers. Mutations were detected as variations in the length of the loci. At the Y-linked loci, the mutation rates (expressed as number of mutations among the total number of loci for the individuals included) are 2.9 x 10(-3) (4/1392) and 2.1 x 10(-3) (3/1458) in the children of exposed and control parents, respectively. This difference is not statistically significant. At the autosomal loci, the corresponding estimates are 5.9 x 10(-3) (11/1862; exposed group) and 8.5 x 10(-3) (18/2108; control). Again, the difference is not significant. The possibility that the Belarusian population might have been unexpectedly exposed to some chemical contaminants in the environment appears unlikely in view of the finding that the spontaneous mutation rates at the same set of loci in several non-Belarusian populations were similar to those in Belarus. The estimated mean radiation dose to the liquidators was small, being about 39 mSv, and this might be one reason why no increases in mutation rates due to radiation could be found.     

Several indices of the peripheral immune system in clean up team workers and patients who survived acute radiation disease 5 years after effects of the radiation accident factors]

A group of liquidators and patients survived acute radiation sickness (ARS) was studied five years after the effect of radiation factors resulted from the Chernobyl A.P.S. disaster. Studied were the number of T-lymphocytes (SD2+, SD3+, SD5+), subpopulations SD16+ and SD25+, the content of SD16+ and SD25+ lymphocytes and B-cells, as well as the levels of serum IgM, A, G; determined was the concentration of serum alpha 1-thymosin. A decrease was noted in the number of T-cells of the examined patients, with respect to all markers studied: the number of SD4+ cells was found decreased in patients with ARS sequelae and normal in liquidators. The decrease in serum alpha 1-thymosin was a function of dose. Dynamics of changes in the T-cells of the examinees may reflect the new trends in the radiation response of T-lymphocytes which were not directly related to initial damages to the latter. The injury to the stroma of the thymus and especially to its epithelial cells may be the basis for later postirradiation damages to the immune system. The decrease in the concentration of alpha 1-thymosin in the blood serum of the examinee is the manifestation of the thymus hypofunction. In liquidators and patients with the ARS sequelae the number of SD25+ cells increased markedly indicating the existence of the source of endogenous cell activation. The content of B-lymphocytes in all studied groups of patients was reduced which may serve as a criterion of chronic stress.     

The cytologic diagnosis of malignant neoplasms in pleural and peritoneal effusions

This study presents data on 3,011 pleural and peritoneal effusion specimens that were examined over a three-year period (1982 to 1984). Totals of 812 (44%) of 1,846 pleural and 423 (36%) of 1,165 peritoneal specimens were positive for malignant cells. While 535 patients had malignant pleural effusions, 254 patients had malignant peritoneal effusions, and 57 had both malignant pleural and peritoneal effusions. The most common primary neoplasms causing malignant pleural effusions were carcinomas of breast (24%) and lung (19%) and lymphoreticular neoplasms (16%). The most common primary neoplasms causing malignant peritoneal effusions were carcinomas of ovary (32%) and breast (13%) and lymphoreticular neoplasms (7%). There was an average interval of more than 30 months between the histologic diagnosis of the primary neoplasm and the diagnosis of malignant effusions in patients with carcinoma of breast, lymphoreticular neoplasm and malignant melanoma. The average time until death following the diagnosis of a malignant effusions was five months or less, except for patients with carcinoma of the breast and carcinoma of the ovary. One hundred twenty-five patients (15%) presented with malignant effusions caused by neoplasms of unknown primary sites. The most common primary neoplasms that were later diagnosed were, in decreasing order of frequency, carcinoma of the ovary, carcinoma of the lung and lymphoreticular neoplasms.     

The experience of FISH technique application for reconstruction of individual radiation doses in Chernobyl liquidators in the framework of Ukrainian-American project "Leukemia"

The results of proper investigations received under the cytogenetic examination of 225 persons (control groups, Chernobyl liquidators exposed to different radiation doses, oncogematology patients) had been summarized and analyzed. The conclusion concerning possibilities and limitations of FISH technique usage for retrospective biodosimetry of human radiation exposure has been presented.