Radiatsionnaia biologiia, radioecologiia最新文献

The vertical distribution of ¹³⁷Cs in Albeluvisols of the spruce forest in the Roslavl district of Smolensk region was investigated. The statistical characteristics of spatial variability and distribution laws for the activity con- centrations and activity depositions of ¹³⁷Cs in upper soil layers (forest litter, 0-5, 5-10, 10-19 cm) were de- termined. Positive correlations between the height, crown length of spruce trees and the content of ¹³⁷Cs in the soil under them were revealed. The regularities of spatial configuration of ¹³⁷Cs contamination in soil were related to the parcel structure of spruce forest. The lateral trends for distribution of 137Cs along the tessers un- der spruce and during the transfer to the open positions between the trees were recorded.

In this paper the contribution of chronic irradiation at low doses (0.42 mGy/h) and dysgenesis to changing morphological parameters (gonadal atrophy/sterility and ovarian reserve) of the reproductive system of female Drosophild melanogaster is rated. It is shown that the sterilizing effect of dysgenesis is enhanced predominantly by irradiation of the maternal line. The level of ovarian reserve of irradiated females depends on the type of dysgenic system. Unlike I-R females in whom the level of radiation-induced ovarian reserve does not differ from the control, both decrease (in P-M females) and increase (in H-E females) is observed in the ovariole number. The results indicate the important role of mobile genetic elements destabilizing the genome in the modification of reproductive functions of females exposed to chronic-action of low-intensity γ-radiation.

Immune status was studied in the framework of the current work and the results of the analysis of concentration of 26 characteristic parameters of innate and acquired immunity in 140 individuals from 56 trios (fathers, mothers and their Ist generation offspring that were included in 2 groups) are presented. Fathers and mothers of the children under study in the main groip Were exposed due to a long-term residence (from childhood to maturity) in the areas of Chelyabinsk region contaminated as a result of the-accident at Mayak PA (contamination included long-lived isotopes - ⁹⁰Sr and, to a smaller extent, ¹³⁷Cs and ²³⁹Pu) and then migrated into Ozyorsk prior to the conception of their children (75 individuals, 33 family trios). Comparison group (control) included parents and their offspring who are Ozyorsk residents never residing in the areas contaminated by radionuclides (65 individuals, 23 family trios). All the investigated individuals from the compared groups were of the corresponding age and gender and had never worked at nuclear facilities. Blood samples were obtained in the periods that excluded oncological, acute infectious and inflammatory diseases of any acute stages of chronic processes. Concentration of immune cells was measured by flow cytometer (Beckman Coulter, USA) using special monoclonal antibodies of the same manufacturer in a licensed medical center "Familia" (Chelyabinsk). The objective of the work is to assess the immune status in parents who migrated from contaminated areas prior to the conception of children and in their 1st generation offspring not exposed to radiation. Alterations of the immune status in the form of increase or, to a smaller extent, decrease of concentration of lymphocytes with effector and/or regulatory functions (B-1, T-helpers, NK, T-NK, late precursors of T-1 and T-1 of late activation) in blood of exposed parents and their offspring were detected in comparison with the results in the control group; that could possibly be related to the stimulation effect of low doses that support activation, proliferation and development of compensatory imbalance in the immune system and immunodeficiency in parents of the main group and in their offspring. In order to reveal the mechanisms of the detected alterations the interrelation between immune damage and incidence, of diseases among the cohorts involved in the current work will be studied further.

Release of liquid radioactive waste into the Techa River from the Mayak Production Association during 1949-1956 resulted in a significant exposure of about 30000 people who lived in downstream settlements. The residents were exposed to internal and external radiation. The article discusses the capability of two methods that were used 50 years after the termination of radioactive discharges for the dose reconstruction, namely EPR measurements of tooth enamel, and FISH measurements of stable chromosome aberrations in circulating lymphocytes. The Main issue in the application of these methods for the dose reconstruction was local irradiation from strontium radioisotopes incorporated in teeth and bones. The EPR and FISH assays were supported by measurements of the 90Sr content in the skeleton and teeth in order to estimate and subtract internal doses from incorporated 89, 90Sr. The resulting dose estimates obtained from EPR and FISH mea- surements were found to be consistent The settlement-averaged values in the upper-Techa Region varied from 550-570 mGy to 130-160 mGy and showed a reduction with the distance from the release site. The EPR- and FISH-based dose estimates were in agreement with the doses calculated with the dosimetry system TRDS that uses data on radionuclide contamination of the Techa River floodplain and individual residential histories.

The number of large deletions of mitochondrial DNA in whole peripheral blood of the former Mayak PA workers occupationally exposed to prolonged γ-radiation has been determined in the long term period after irradiation (mean cumulative dose 135.40 ± 22.03 cGy, age range at the time of blood sampling 67-76 years) and compared with the number of deletions in groups of "young" (19-33 years) and "adult" (66-73 years) individuals who had no contact with radiation sources. Samples of the total DNA from the peripheral blood were obtained from the Radiobiological Human Tissue Repository of the Southern Urals Biophysics Institute (Ozyorsk, Chelyabinsk region) and used for carrying out a long-distance PCR. The analysis of the data showed a statistically significant increase in the number of large deletions in the peripheral blood of "adult" donors of the control group as compared with the control group of "young" donors (51.6 and 14.3%, respec- tively). No statistically significant difference in the number of large deletions in the group of former Mayak PA workers occupationally subjected to prolonged exposure to γ-radiation as compared with the control do- nors of similar age was found (53.6 and 43.8% respectively).

This article describes the results of systemic transplantations of cardiomyoblasts grown from autologous or allogeneic bone marrow-derived mesenchymal stem cells, in the complex therapy of the late radiation da- mage of the heart, which developed after radiation therapy in 16 female patients with Hodgkin disease (HD) or breast cancer (BC). The cell therapy drastically improved the efficacy of the drug treatment, which earlier was the only option for the therapy of the radiation damage of vital organs. The effect of such therapy was clinically observed in the patients already in the first year of observation, and consisted in the decrease of the degree of the cardiac failure severity and improvement of their quality of life in the absence of HD or BC progression.

Individual doses from external γ-rays were estimated using biological dosimetry based on limited samplings (n₁= 15 and n₂ 12 individuals) which comprised the Mayak workers group with acute radiation sickness (ARS). The following primary data were used for calculation as initial parameters: estimated dose from ex- ternal γ-rays based on physical dosimetry methods - D (Gy); time before first vomiting - T (h); number of lymphocytes in peripheral blood on a second day after acute radiation exposure - L (10⁹/1); number of neutrophils in blood during first hours after accidental radiation exposure - N(10⁹/). A number of mathe- matical models used for dose estimation were verified: power-law dependence of the absorbed dose from ex- ternal γ-rays (D) on time before first vomiting (7), exponential dependence of D on the number of lympho- cytes in peripheral blood (L), dependence of D on the number of neutrophils in peripheral blood (N) and complex models forD association with Tand L parameters as well as-with Tand Nparameters. The biological dosimetry technique based on a complex approach was shown to provide the best agreement with physical dosimetry methods for individual assessment of doses from external γ-rays.

Changes in the weight of reproductive system organs, quantitative and qualitative indicators of the epididymal spermatozoa of rats on the Ist and 30th days after the end of an electromagnetic exposition from the mobile phone (1745 MHz, the 8 hour/day, power density 0.2-20 μW/cm²) of various duration (from 1 to 90 days) have been researched. A significant increase in the absolute and relative weight of the epididymis and seminal vesicles and the number of epididymal spermatozoa was revealed on the 1st day after electromagnetic expo- sure during 7 days. The increase in the exposure duration up to 14 days is accompanied by a fall of the above indicators, and after a longer exposure (30, 60 days) there is an increase of the absolute weight of the testes; in all other cases, significant deviations in terms of the weight of reproductive organs are not observed. Expo- sition of various duration at 1745 MHz, except for 7-day radiation exposure, had no significant effect on the amount of epididymal spermatozoa and DNA fragmentation in them; however, viability of mature male germ cells in irradiated animals decreases independently of the duration of exposure. The revealed disturbances of the researched indicators are mainly normalized in the remote period (on the 30th day) after electromagnetic radiation.

The current data of radioecological research within the Semipalatinsk test site (STS) are presented in the pa- per. It has been shown that almost 90% of polygon lands can be returned to the national economy. Waters of water facilities located at conditionally "background" territories of the STS do not present a radiation hazard to population. Waters of the potential water facilities located close to the radiation hazardous facilities have an increased level of the specific activity of individual radionuclides. Recommendations for the radiological assessment of the quality of waters in water facilities located near radiation hazardous facilities and adjacent territories of STS are offered in the article.

At present volumetric activity of β-emitting radionuclides in water at various locations of the Techa River ranges from 5 to 40-Bq/L; a specific activity of β-emitting radionuclides in the bottom sediments at various locations ranges 10 Ito 106 Bq/kg dry weight. A significant increase of the erythroblast content in blood as compared to that in the roach from the reference watercourse (the Miass River) was observed during spawning in the spring. Due to this fact the number of erythrocytes was equal to that in the control animals under chronic radiation exposure at the dose rates of 0.9 and 16 μGy/day, and was insufficient at the dose rate of 108 gGy/day. During summer feeding no changes in the indexes of erythropoiesis in roach were observed under chronic radiation exposure at the dose rate of 0.9 μGy/day; the number of erythrocytes in the peripheral blood declines when the dose rates are 16 and 108 μGy/day. When performing a regression analysis, we revealed a dose-rate-dependent decrease in the absolute number of erythrocytes, normocytes, polychromatocytes, dividing and non-dividing erythroid cells in the peripheral blood of roach from the Techa River and an increase of a relative number of normochromatophylic erythrocytes.