[Deletions in Mitochondrial DNA from the Peripheral Blood of Mayak PA Workers Exposed to Long-Term Ionizing Radiation].

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).

[Radiobiological Human Tissue repository: progress and perspectives for solving the problems of radiation safety and health protection of personnel and population].

Radiobiological Human Tissue repository was established in order to obtain and store biological material from Mayak PA workers occupationally exposed to ionizing (α- and/or γ-) radiation in a wide dose range, from the residents exposed to long term radiation due to radiation accidents and transfer of the samples to scientists for the purpose of studying the effects of radiation for people and their offspring. The accumulated biomaterial is the informational and research potential that form the basis for the work of the scientists in different spheres of biology and medicine. The repository comprises 5 sections: tumor and non-tumor tissues obtained in the course of autopsies, biopsies, surgeries, samples of blood and its components, of DNA, induced sputum, saliva, and other from people exposed or unexposed (control) to radiation. The biomaterial is stored in formalin, in paraffin blocks, slides, as well as in the freezers under low temperatures. All the information on the samples and the registrants (medical, dosimetry, demographic, and occupational data) was obtained and entered into the electronic database. A constantly updated website of the repository was developed in order to provide a possibility to get acquainted with the material and proceed with application for biosamples for scientists from Russia and abroad. Some data obtained in the course of scientific research works on the basis of the biomaterial from the Repository are briefly introduced in the review.

[Variability of DNA simple sequence repeats in peripheral blood of humans subjected to prolonged exposures of ionizing radiation].

Long-term post-radiation changes in the level of microsatellite DNA polymorphism in peripheral blood of the male "Mayak" employees (Ozyorsk, Russia), who had been exposed to prolonged gamma-irradiation during professional activities, were studied. DNA samples were obtained from the Radiobiology Repository of Human Tissue (Southern-Urals Biophysics Institute FMBA) and used as templates for arbitrarily primed PCR. Comparative analysis of the obtained samples of DNA fragments showed a significant increase in the number of high-molecular fragments and reduction in the number of amplified low molecular weight DNA fragments in comparison with the control. However, a direct correlation of the level of DNA polymorphism with the accumulated total dose of radiation was not found. The study of the polymorphism of microsatellite DNA repeats can be used for qualitative assessment of the levels of genetic variability.

[Radiation and nonradiation factors in thyroid pathology development for Chernobyl cleanup workers--residents of Mayak PA affected zone].

Thyroid state study was been carried out for Chernobyl NPP accident liquidators living in Ozyorsk, the city, located in the nuclear facility affected zone (Mayak PA). In total 531 individuals were examined. Thyroid assessment was made basing on physical examination, on ultrasound study and on hormones measurement of thyroid stimulating hormone, free thyroxine and thyroid peroxidase antibody. Screening revealed thyroid pathology for 27% of clean-up workers. As a result of the study carried the following conclusions were made: thyroid disease prevalence among the Ozyorsk residents participated in the breakdown elimination after Chernobyl accident was not differ from the individuals who didn't take part in this work; the prevalence of thyroid disease in liquidators was significantly connected with non radiation risk factors: with gender (for women compared to men), RR = 4.0, 95% CI 2.9-5.5; with age (over 60 years old vs under 60 years old), RR for women was 1.7; 95% CI 1.0-3.0 and for men -1.9; 95% CI 1.1-3.2; with hereditary predisposition, RR for autoimmune thyroiditis was 3.3, 95% CI 1.4-7.9.

[Analysis of classifications of chronic pancreatitis and criteria determining the strategy of surgical treatment].

The authors made an analysis of most widespread classifications of chronic pancreatitis and results of the retrospective distribution of 120 patients in them. A conclusion is made that the volume of surgical interventions in most cases is determined by morphological alterations in the pancreas. The most important of them are thought to be changed pancreas parenchyma (criterion "P"), large cavities (criterion "C") and dilatation of Wirsung's duct (criterion "H"). Such morphology is an indication for transferring the patient to the surgical department. The clinical picture and morphological analysis determine expediency of surgery. The method of surgical treatment depends on the localization and combination of morphological alterations.

[The parameters of clearance of industrially significant alpha-emitters from the lungs of mammals].

Results of assessment of biokinetic parameters of change in the burden of significant alpha-emitters in the lungs of mammals in various times after inhalation intake (Qt(lung)) were generalized. 1740 Wistar rats of both sex with the initial age of 2-2.5 months and 143 mature mongrel dogs used in 23 and 3 animal tests, respectively, were involved in this work. The analysis of experimental data resulted in selection of three groups of chemically soluble compounds of alpha-emitters that differ in the rate of radionuclide clearance from the lung as well as in integral doses. Stable complex compounds of quadrivalent and of hexavalent nuclides and non-complex salts of quinquivalent and of hexavalent 237Np were assigned to the group of soluble compounds of 239Pu and 237Np. A three-component exponential model of change in Qt(lung) with the prevalence of fast and of intermediate phases (55%, T(eff) = 0.41 days and 35%, T(eff) = 18.1 days respectively) and the presence of a slow clearance phase (10%, T(eff) = 206 days) was developed for these compounds. Complex compounds of quadrivalent 239Pu and 237Np unstable in the environment of pH and of body temperature, their non-complex salts of mineral acids in ionic or polymer form, and submicron plutonium dioxide (SMD = 0.07 mkm) were assigned to the group of relatively soluble compounds includes. An exponential model with 2-3 components with the prevalence of intermediate and of slow clearance phases (71%, T(eff) = 19.3 days and 22%, T(eff) = 169 days respectively) was developed for compounds of this group. The third group of the compounds is presented based on the soluble 241Am compounds that could be typical for stable trivalent compounds of rare-earth and transuranium radionuclides. Their biokinetics is described by a 3-4-component exponential model with the fast phase prevailing (96.7%, T(eff) < or = 6.8 days), and with intermediate (2.6%, T(eff) = 69 days) and with slow (0.7%, T(eff) = 1040 days) phases being negligible. Physical chemicas and biological processes determining nuclides biokinetics in lungs are discussed.

[The predictive value of cyclic nucleotide ratio in the prognosis of experimental tumors]. / Informativnost' testa sootnosheniia tsiklicheskikh nukleotidov pri prognozirovanii zlokachestvennykh opukholei v éksperimente.

The report deals with the predictive value of a procedure for lifetime detection of tumor in experimental animals. The database included the results of regular cAMP/cHMP tests carried out in 54 rats with radionuclide-inducted tumors and 24 tumor-free rats. The data were processes by statistical methods and the informative value was determined on the basis of standard recommendations. The test was shown to have high sensitivity (85.2%), sufficient predictive value (73%) and diagnostic effectiveness (68%). Application of the test in groups of humans at high risk of tumor development is discussed.

[The antioxidant therapy of cholestatic liver depression in diabetics]. / Antioksidantnaia terapiia kholestaticheskoi gepatodepressii u bol'nykh sakharnym diabetom.

Lipid peroxidation of cell membranes and liquid media of the organism were studied in 54 diabetics with the cholestatic syndrome, and fundamentals of antioxidant therapy of this cohort of patients discussed. The predominant efficacy of bio-oxidants has been revealed. The mechanism of their action is realized primarily at the stages of initiation and ramification of the chain of free radical oxidation. The authors searched for a sufficiently effective combination of antioxidants for the treatment of medium-severe and grave hepatodepression in patients with sub- and decompensated diabetes mellitus, as well as for the optimal method of antioxidant therapy.

Potentiation of glutamate-activated currents in isolated hippocampal neurons.

"Fast chemical stimulation" was shown to induce potentiation of glutamate-activated currents in neurons isolated from rat hippocampus. A fast application system allowed solution changes up to a rate of 20 Hz. In Mg2(+)-free solution, the response to glutamate application immediately after repetitive stimulation with glutamate plus glycine was increased by 25%-88%, returning to control levels over 10-15 min. Enhancement of glutamate-induced currents was also seen after stimulation with solutions containing aspartate or NMDA plus glycine. Aspartate-induced currents were not potentiated. These and other observations demonstrate that in a purely "postsynaptic" system, short-term potentiation can be induced and is mediated via NMDA receptors whereas the potentiated current is carried via non-NMDA glutamate receptor channels.

[Absorbed doses and hematological shifts in dogs inhaling submicron 239Pu dioxide]. / Pogloshchennye dozy i gematologicheskie sdvigi u sobak pri ingaliatsii submikronnoi dvuokisi 239Pu.

In dogs breathing submicron 239Pu dioxide, the absorbed doses were determined in 12 organs and tissues where the radionuclide was deposited; the integral doses to a whole body were also determined by the sum of the exposed organs. The relationship of the hematologic changes not only with the doses for "critical" tissues but also with the integral dose was studied.

[Method for isolating single cardiac cells in the guinea pig using pronase. The role of calcium ions]. / Metod vydeleniia odinochnyklh serdechnykh kletok morskoii svinki s pomoshch'iu pronazy. Rol' ionov kal'tsiia.

A method for isolation of guinea-pig cardiomyocytes with pronase has been developed. The method has been assessed in hearts perfused with solutions containing pronase (1 U/ml) and 200 microM Ca2+. Eighty per cent of the cells released were rod-shaped and 1.2 mM Ca2+ tolerant. Enriched medium 199 was used for all solutions. Sodium and slow inward currents recorded from cells dispersed with pronase were similar to those recorded from cells isolated after prolonged exposure to collagenase. Two principal factors are to be marked: (a) presence of high enough amounts of Ca2+ in enzyme solution (up to 200 microM); (b) use of the enriched medium in all the stages of the procedure.