[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.

[The use of temporal temperature gradient gel electrophoresis to reveal mutations in peripheral blood mitochondrial DNA].

The mutations in mitochondrial DNA (mtDNA) arise at a higher frequency than in nuclear DNA, and their appearance in peripheral blood can be considered as a sensitive marker to estimate the level of genotoxic load. For revealing the presence of mutations in mtDNA of peripheral blood, we used the method of temporal temperature gradient gel electrophoresis (TTGE). The samples of whole blood DNA from four donor groups were used. Group I contained 10 young (23-26 years) donors and Group II 12 elderly (65-74 years) donors. Group III was formed from patients with breast cancer (12 women) past sessions of radio-chemotherapies (RCHT). Group IV was made of professionals of a nucleus plant occupationally exposed to chronic gamma-irradiation. PCR was carried out on four coding sequences and on one hypervariable sequence of the D-loop (DloopI) of mtDNA. PCR products were tested with TTGE. Most mutations were revealed in the DloopI. Heteroplasmy in the region of DloopI was registered in the blood of each donor of Group III 7 days after the RCHT session. Also, mutations in mtDNA Dloop1 were found in 6 of 13 individuals of Group IV. The blood of this donor group was taken 16 to 28 years after prolonged irradiations in a dose range of 250-350 cGy. In the elderly donor group, the same results were observed in 3 of 12 individuals. The results show that the method of TTGE can be used in mass analyses to assess the effects of radiation and other genotoxic agents in man by detection of unknown mutations in peripheral blood mtDNA.

[Hematopoietic precursor cells in Wistar rats with acute myeloblastic leukemia]. / Krovetvornye kletki-predshestvenniki u krys porody Wistar s ostrym mieloblastnym leikozom.

The studies were performed on Wistar rats with acute myeloblastic leukemia induced by a prolonged administration of tritiated water (370 MBq/kg/day-1; an absorbed dose--25.3 Gy) and by repeated pyrogenal injections. A reduction of the pool of polypotent hemopoietic cells (CFUs) with a simultaneous increase of their proliferative activity and a decline of their ability to self-supporting were observed in the leukemia-bearing animals. Populations of CFUdc in DC and of CFUc were reduced in all cases; their colony-forming ability was also found to decrease. All animals with leukemia showed a lowered amount of CFU-BL in the bone marrow and of CFU-TL in the thymus, although the content of these cells in the peripheral blood remained unchanged.

[Cytogenetic characteristics of H3 oxide induced myeloid leukemia in Wistar rats]. / Tsitogeneticheskaia kharakteristika mieloidnykh leikozov, indutsirovannykh okis'iu 3H u krys Wistar.

Frequency and spectrum of chromosomal aberrations were studied in hemopoietic cells of Wistar rats myeloid leukaemia induced by the prolonged exposure to tritium oxide. Differences in quantitative and structural damages of chromosomes were revealed by the cytogenetic assessment of eighteen rats with acute myeloid leukaemia (AML) and six rats with chronic myeloid leukaemia (CML). The most characteristic chromosomal aberrations for AML appeared to be rearrangements in chromosomes 1-3. In CML translocations by one of chromosomes 15-20 coupled with defects in the groups of chromosomes 5-10 seemed to be nonrandom.

Tritium radiobiological effects in mammals: review of experiments of the last decade in Russia.

This review briefly describes techniques and basic results of experimental investigations in mice and rats on metabolism, dosimetry, and radiobiological effects of tritium oxide and some tritiated biogenic compounds (glucose, amino acids, and nucleosides) during the last 10 to 15 years in Russia. The content of water in tissue cells of mammals is shown to be 15 to 40% less than in whole tissue. The kinetics of tritium incorporation from oxide (HTO) and its retention in DNA of hemopoietic tissues were studied. The contribution of bound tritium to dose strongly depends on the chemical form of tritium and reaches 90% when labeled L-lysine is injected. Specific features of the action of HTO on hemopoietic tissue were investigated in tests of damage and repair of DNA, induction of chromosome aberrations in cells, content of nucleic acids, kinetics of cell populations, immunity parameters, carcinogenesis, decrease of life span, induction of dominant lethal mutations in germ cells in male mice, and reciprocal translocations in mouse spermatogonia. According to these tests, the radiobiological effects of tritium beta radiation in the form of oxide is 2 to 6 times higher than for gamma radiation of 137Cs. The frequency of dominant lethal mutations induced by labeled lysine, thymidine, and deoxycytidine is 3 to 12 times higher than those induced by equal HTO activity. The results of these investigations are used to standardize HTO and the various biogenic compounds of tritium, improve techniques of indirect dosimetry, provide medical aid to personnel, and estimate population risk.

Assessing the uniformity of plutonium alpha radiation dose in human lung: the Mayak experience.

Radiation-induced lung cancer risk is currently estimated based on epidemiological data from populations exposed either to relatively uniform, low-LET radiation, or from uranium miners who inhaled radon and its progeny. Inhaled alpha-emitting radionuclides (e.g. Pu and Am) produce distinctive dose patterns that may not be adequately modelled at present. Thus the distribution of Pu is being measured in formalin-fixed autopsy lung tissue from former workers at the Mayak Production Association, and which is maintained in a tissue archive at SUBI. Lungs are sampled using contemporary stereological techniques and Pu particle activities and locations are determined using quantitative autoradiography and morphological identification of lung structures. To date, > 80% of Pu particles have been observed in parenchymal lung tissues with higher concentrations being found in scar tissue. Concentrations of Pu particles in conducting airways are uniformly low, thus indicating that long-term-retained Pu particles are non-uniformly distributed in human lung, mostly in the parenchyma.

[Experimental study of anti-radiation effects of interleukin-1 beta]. / Izuchenie protivoluchevogo deistviia interleikina-1 beta v éksperimente.

Therapeutical effect of human recombinant IL-1 beta on exposed CBA mice was shown. Single injection of IL-1 beta into mice exposed to LD70, LD80 and LD100 raised their 30-day survival by 60, 40 and 35%, respectively. Therapeutically effective doses of IL-1 beta were 100-200 micrograms/kg. Multiple injections of the preparation were ineffective.

[Cytogenetic effects of alpha-irradiation due to incorporated 239Pu]. / Tsitogeneticheskie éffekty alpha-oblucheniia inkorporirovannykh 239Pu.

Intravenous injection of plutonium dioxide with 1-2 microns particle sizes in amount of 92.5, 46.3 and 23.2 kBq/kg of body mass increased the yield of chromosome aberrations in bone marrow cells of rats by 3.7, 2.3 and 1.7 times, correspondingly, in comparison with the spontaneous level. The model of chromosome aberration dependence on dose of radionuclide was developed based on the experimental results.

[State of cellular immunity effectors of the lung in inhalation exposure to low-transportable Pu-239]. / Sostoianie populiatsii éffektorov kletochnogo immuniteta legkikh pri ingaliatsionnom postuplenii nizkotransportabel'nogo 239Pu.

The reduction of populations of lung cell immunity effectors as well as changes in their cytotoxic and phagocytic activity was observed in rats after inhalation exposure to polymeric 239Pu. Dose-response curves described as a function of absorbed dose of alpha-irradiation in lung.

[Comparative study of hazards of energy plutonium and standard Pu-239 using non stochastic effects]. / Sravnitel'naia opasnost' énergeticheskogo plutoniia i standartnogo 239Pu po nestokhastichesksim éffektom.

In experiment with rats it was found that the "energy" Pu is more toxic than standard 239Pu when entered endotracheally. The comparison was made by the non-stochastic effects. The toxicity in respiratory system and blood system was 1.8 and 1.6 times higher when calculated per 1sGy of absorbed dose and 1.6 and 1.1 times higher when calculated per 1kBg/kg of the amount taken, respectively.

[Effect of mammalian and Escherichia coli DNA on rat somatic cell chromosomes]. / Vliianie DNK mlekopitaiushchikh i Escherichia coli na khromosomy somaticheskikh kletok krys

High-polymer DNA isolated from mammalian lymphoid tissues (rat spleen, calf thymus) and from Escherichia coli increases the frequency of quantitative lesions in bone marrow cells of normal Wistar rats. The highest percentage of aberrant metaphases was revealed 24 hours after the injection of mammalian DNA, the frequency of aberrations being 9 times higher than the control values after the injection of heterologous DNA and 6 times higher-after the injection of homologous DNA. The effect observed was not a prolonged one, and 72 hours following the DNA injection the numbers of aberrant cells decreased to the control level. The maximal frequency of aberrations in bone marrow cells of rats treated with bacterial DNA was found 72 hours after the injection, when a 4-fold increase above the spontaneous aberration level was observed. Definite differences in the character of structural changes of chromosomes induced by DNA of different origin were revealed. Mammalian DNA injected produced the chromatid-type aberrations only. The injection of bacterial DNA led to the formation of both chromatid and chromosome aberrations. Possible mechanisms of the increase of chromosome aberration frequency in rat somatic cells under the action of high-polymer DNA of different origin are discussed.

[Determination of the efficiency of reparative processes in the chromosomes of bone marrow cells in vivo by using test irradiation]. / Opredelenie éffektivnosti reparativnykh protsessov v khromosomakh kletok kostnogo mozga in vivo s pomoshch'iu test-oblucheniia.

The method developed on rats was applied to estimate the effectiveness of reparative processes in myelokaryocyte chromosomes using the test-irradiation in vivo (0.5 Gy, gamma-rays of 137Cs). The method is based on the comparison of the curves demonstrating the chromosome aberration yield in the first mitosis following the test-irradiation of experimental and control animals.

[The frequency of chromosome aberrations in rat bone marrow cells in the late period after a single uptake of tritium]. / Chastota aberratsii khromosom kletok kostnogo mozga krys v otdalennom periode posle odnokratnogo postupleniia tritiia.

A prolonged self-maintenance of haemopoietic tissue cells with stable chromosome rearrangements following a single intake of tritium oxide in the amount of 24 MBq/g of body weight (absorbed dose of 11 Gy) is shown. Mutant cells revealed long after the radionuclide exposure are descendants of stem-cell precursors, bearing stable chromosome aberrations during the period of formation of radiation injury after the radionuclide administration.

X-ray fluorescence microscopy for investigation of archival tissues.

Several recent efforts in the radiation biology community worldwide have amassed records and archival tissues from animals exposed to different radionuclides and external beam irradiation. In most cases, these samples come from lifelong studies on large animal populations conducted in national laboratories and equivalent institutions throughout Europe, North America, and Japan. While many of these tissues were used for histopathological analyses, much more information may still be obtained from these samples. A new technique suitable for imaging of these tissues is x-ray fluorescence microscopy (XFM). Following development of third generation synchrotrons, XFM has emerged as an ideal technique for the study of metal content, speciation, and localization in cells, tissues, and organs. Here the authors review some of the recent XFM literature pertinent to tissue sample studies and present examples of XFM data obtained from tissue sections of beagle dog samples, which show that the quality of archival tissues allows XFM investigation.

[Damage to the hematopoietic system of BALB/c and CBA mice undergoing long-term repeated irradiation]. / Povrezhdenie krovetvornoi sistemy myshei linii BALB/c i CBA pri dlitel'nom povtornom obluchenii.

A higher death rate of BALB/c as compared to CBA mice was registered during long-term external irradiation. The changes in the content of the morphologically recognized bone marrow cells and blood formed elements in the exposed mice of the studied lines were different.

[Injury of the rat hematopoietic stem pool during prolonged external irradiation]. / Povrezhdenie stvoloogo krovetvornogo pula u krys pri dlitel'nom vneshnem obluchenii.

The haemopoietic stem pool in rats exposed to long-term repeated irradiation with a cumulative dose of 10 Gy was irreversibly reduced. Proliferating, maturing and functional pools were restored completely. Possible mechanisms of the impairment of the CFUs population recovery are discussed.

[Impairment of recovery of the hematopoietic stem pool after long-term external irradiation]. / Narushenie vosstanovleniia stvolovogo krovetvornogo pula posle dlitel'nogo vneshnego oblucheniia.

A stable decrease in the polypotent CFUs pool of CBA mice was observed after long-term irradiation the cumulative doses being 10 Gy (0.06-0.5 Gy/day) and 1.8-2 Gy (0.01 and 0.5 Gy/day). With the comparable values of the cumulative dose the share of the unrepaired part of the haemopoietic pool increased with the increase in total time of exposure.

[Capacity of hematopoietic colony-forming cells to maintain their own population in the late periods after prolonged radiation exposure]. / Sposobnost' krovetvornykh kolonieobrazuiushchikh kletok k podderzhaniiu sobstvennoi populiatsii v pozdnie sroki posle dlitel'nogo radiatsionnogo vozdeistviia.

The content of multipotent CFUs in bone marrow and their self-maintenance capacity were studied for 15 months following protracted external radiation of CBA mice at the total dose 10 Gy (0.5 Gy per day). The mean life shortening was 16% in the irradiated mice. The proliferating, maturating and functional pools returned to normal within 1-3 months after exposure. The stem cell pool did not return to the values seen in the same age controls till the end of the life of experimental animals and averaged 55% of normal. The self-maintenance capacity of bone marrow CFUs was 2.5-4.5-fold as decreased in the irradiated mice. The failure of this unique property of multipotent CFUs was principally due to the foregoing increase in their proliferative activity.

[Chromosome aberrations in hematopoietic stem cells in late periods after prolonged external irradiation]. / Aberratsii khromosom v rodonachal'nykh krovetvornykh kletkakh-predshestvennikakh v pozdnie sroki posle dlitel'nogo vneshnego oblucheniia.

At remote times following long-term external irradiation of Wistar rats with a cumulative dose of 10 Gy a 2-4-fold increase was registered in the spontaneous yield of chromosome aberrations in a population of original haemopoietic cells-precursors mainly due to symmetrical inter- and intrachromosomal exchanges.

[Inactivation of non-syngeneic hematopoietic stem cells by mouse lymphocytes after long-term exposure to tritium oxide]. / Inaktivatsiia T-limfotsitami myshei nesingennykh stvolovykh krovetvornykh kletok posle dlitel'nogo deistviia okisi tritiia.

A study was made of functional activity of lymphocytes, which inactivated nonsyngeneic colony-forming units (CFU) in allogenous and xenogenous interaction systems, at different times after long-term action of tritium oxide in a cumulative dose of approximately 9 Gy. The function of these lymphocytes was depressed during the first months after termination of exposure while at later times it exceeded the control level. The consequences of the interaction between lymphocytes and nonsyngeneic CFU were also studied in this work.