Radiatsionnaia biologiia, radioecologiia最新文献

The aim of this study is to assess the level of somatic mutagenesis according to the frequency of lymphocytes bearing mutations at the locus of T-cell receptor (TCR) in the residents of the Bryansk region contaminated with radionuclides as a result of the Chernobyl accident. The study was :conducted in 2014 in two regional centers - Klintsy and Novozybkov (average¹³⁷Cs pollution density of 322 and 708 kBq/m²,.respectively). The average frequency of the TCR-mutant cells in the total group of examined residents of the Bryansk region (n = 237) was not significantly different from that in the group of agematched control persons living in un- contaminated areas (n = 146): 3.8 x 10⁻⁴ vs 3.5 x 10⁻⁴, respectively (p = 0.84). However, after separation of examinees into 3 groups depending on age at the start of irradiation (at.the moment of the Chernobyl acci- dent) it was found that the average frequency of the TCR-mutant cells in the persons exposed in utero was 1.6 higher than that in the control group (p = 0.04). Proportion of persons with an increased frequency of the mutant cells (more than the age norm of this indicator) among prenatally exposed population reached 23.8%; which was about.4 times higher than in the control group (p = 0.04). Proportion of persons with an increased frequency of the TCR-mutant cells in group "0-17 years at the start of irradiation", was about 2 times higher than in controls, but this difference was not statistically significant (8.0% vs 4.3%, respectively, p = 0.33). In the third group "18 or more years old at the start of irradiation" we could not register the difference in the average frequency of theTCR mutant cells or the proportion of persons with an increased frequency of these cells in comparison with the age-matched control group. In general, comparison with earlier data shows that age-related regularities of somatic mutagenesis established 15-18 years after the Chernobyl accident persist at a later date (after 28 years in this study).

Results of long-term immunological monitoring of liquidators of consequences of the Chernobyl accident and the revealed regularities are presented. Earlier the unknown phenomenon of the activating influence of radiation at small doses on the T-cellular link of the immune status (IS), mainly on T-lymphocytes/helper was for the first time established. This phenomenon came to light among participants of LPA working in an extreme situation of 1986 in the zones of the CN PP and further was confirmed by inspection of the personnel of a 30-km zone of the CNPP in 1990; the personnel at radiation dangerous nuclear power plants and the population living near these objects, the population polluted by radionuclides on the territories of the Bryansk region. This effect in the presence of clinical symptoms which can be caused by influence of a radiation factor was most expressed. Prognostic value of the changes in the development of IS immune insufficiency (ID), cellular and humoral link in the near future after taking part in clean-up workers are established. These laws have a theoretical value for immunology and radiobiology, and practical health care as well, as the formation of a phenotype of IS defines approaches to immunoprophylactics and immunocorrection, as in extreme situations, and in the following years. During the delayed periods development of an imbalance, immune in- sufficiency in T-lymphocytes and natural killer cells is revealed. By the end of the 3rd - the beginning of the 4th fifth anniversary after the accident the high frequency of clinical manifestations of immune dysfunction and chronic somatic diseases was defined. The immunological characteristic of an immunoproliferative syn- drome that allowed one to reveal predictors of early diagnostics of malignant new growths in immune status is for the first time established. Clinical-immunological signs of early aging of liquidators and features of changes in liquidators in the lipidic status depending on the age and risk factors of Chernobyl accident are revealed. Features of antiviral protection of an organism ofliquidators that is defined by changes in the cluster of genes of cytokines (IL28A, IL28B and IL29) localized on the 19th chromosome (19ql3) of the person are established. Establishment of genotypes can be associated with a positive effect of treatment, steady and long remission of GVI.

The article analyzes the results of using the imitation modeling method for the study, prediction and recon- struction processes of radionuclide. behaviour in terrestrial ecosystems after the Chernobyl accident. Also discussed are some additional issues associated with the application of this method and perspectives of radio- ecological modeling.

There are 2 most important questions regarding studies of the Chernobyl disaster: to what degree the opportunities to decrease injuries of the people affected by the disaster were realized and how the study of the con- sequences of the disaster impacted elucidation of low level radiation damage to human health. It can be as- sumed that not all scientific elaborations were realized to a proper degree (the use of iodine prophylaxis, radioprotectors). It was associated with impoper fulfillment of instructions by executive organs of radiation safety and medical emergency aid. However, the stationary medical treatment of patients with acute radiation disease was well organized. Insufficient consideration was given to non- radiological factors having an effect or,the psycho-emotional state of the people. Harmful effects of small doses on human health were not be found. The adverse delayed consequences (thyroid cancer, leucosis, and solid cancers) were found in the case of exceeding dose limit of 250 mGy. The upper border of low harmless.radiation doses could not be detected in those studies because of poor radiation dosimetry of liquidators, inadequate models of risk evaluation and ignoring influence of non-radiological factors on human health.

Previously developed mathematical model of simultaneous action of two inactivating agents has been adapted and tested to describe the results of sequential action. The possibility of applying the mathematical model to the interpretation and prognosis of the increase in radio-sensitivity of tumor cells as well as mammalian cells after sequential action of two high temperatures or hyperthermia and ionizing radiation is analyzed. The model predicts the value of the thermal enhancement ratio depending on the duration of thermal exposure, its greatest value, and the condition under which it is achieved.

This study was aimed to compare mFISH and mBAND techniques in assessment of the yield of chromosomal aberrations induced by high-LET ionizing radiation. The study group included Mayak workers (46 individuals), for whom the yield of chromosomal aberrations was assessed using two methods: mFISH and mBAND. It was shown that both methods are applicable for biological indication of internal α-radiation exposure. Nevertheless, in case when the source of ionizing radiation is unknown or in terms of a mixed exposure, mFISH appeared as more informative technique that allows identification of markers both external γ-rays (translocations) and internal α-radiation (complex chromosomal rearrangements).

Multipotent mesenchymal stromal cells (MSC) are now considered to be a perspective multifunctional treatment option for radiation side effects. At present.a great number of sufficient evidence has been collected in favor of therapeutic effects of MSCs in acute radiation reactions. It has been shown that MSC-based products injected locally or systemically have therapeutic effects on irradiated organs and tissues. This review presents summarized experimental and clinical data about protective and regenerative effects of MSCs on different radiation-injured organs and tissues; the main probable therapeutic mechanisms of their action are also discussed.

The results of experimental studies on the biological effects and mechanisms of action of antitumor and radio modifying weak low-frequency turbulent magnetic field (TMF) on tumor objects of different levels of integration are presented. The studies have been conducted in the Russian Cancer Research Center named after Blokhin of the Russian Academy of Medical Sciences using the methods and criteria applied for the evaluation of antitumor efficacy of new drugs and impacts. Studies of the direct TMP action on tumor cells demonstrate the inhibitory effect on the DNA synthesis, also shown is the ability of TMP to induce apoptosis. It has been shown that exposure to TMF increases the functional activity of phagocytes, which manifests itself in increased level of non-specific resistance of the organism to the tumor process, and represents one of the possible mechanisms of the antitumor action. The discovered radio modifying effect of TMP opens the prospects for its use in combination with radiotherapy. Possible hypotheses about biophysical mechanisms of the established biological effects of TMP are presented. The presence in this physical factor of its own antitumor activity can be of interest for further research.

This study has been completed in the frames of activities on the environment assessment in the vicinity of the Far Eastern center (FEC) on radioactive waste treatment (a branch of Fokino, Sysoev Bay). Underground waters collected at the FEC technical site were surveyed both with instrumental techniques and bioassays. Concentrations of some chemicals (ranged to the third hazard category) in the samples collected are over the permitted limits. Activities of 137Cs and 90Sr in waters amount up to 3.8 and 16.2 Bq/l, correspondingly. The integral pollution index is over 1 in all the samples and could amount up to 165. The Allium-test application allows the detection of the sample points where underground waters have an enhanced mutagenic potential. Dependencies between biological effects and pollution levels are analyzed. The findings obtained could be used for the monitoring optimized and decision making on rehabilitation measures to decrease negative influence of the enterprise on the environment.