Regularities of lateral distribution of uranium and thorium decay series radionuclides in the anthropogenically changed soils from the area of radium production waste storage

Cartographical investigations of the territory of radium production waste storage has shown some changes in lateral differentiation of radionuclides of uranium and thorium decay series to occur during 27 years (1981-2008). Those changes are caused mostly by flat denudation typical for fluvial terrace. At present radionuclides of uranium and thorium decay series are concentrated mostly in flood lands and relief depressions. At the same time, decrease in the radionuclide activity concentration in 0-20 cm soil layer is observed with changes in lateral distribution. Total stocks of 226Ra, 210Pb and 210Po within catena soils studied in the northern and southern parts of the waste storage decreased 3-6 times, 238U - 2 times, and did not significantly change in case of 232Th during 27 years. Nonetheless, most of the samples studied are referred to radioactive waste both according to Russian standards (SPORO-2002) and IAEA safety norms (IAEA, 2004).     

Alteration of the immune response to Mycobacterium bovis BCG in mice exposed chronically to low doses of UV radiation

BALB/c mice were exposed on shaved dorsal skin to 1 minimal erythemal dose (MED) of UVB radiation (2.25 kJ/m2) from a bank of six FS-40 sunlamps three times per week. The total number of irradiations ranged from 1 to 27. At regular intervals, groups of mice were injected in the left hind foot pad with 1 x 10(6) live mycobacteria (Mycobacterium bovis BCG) 3 days after the last UVB exposure. The mice were tested 21 and 42 days after infection for a delayed type hypersensitivity (DTH) response to the purified protein derivative (PPD) of tubercle bacilli by injecting PPD into the right hind foot pad and measuring the foot pad swelling 24 hr later. The course of infection was followed by assessing the number of bacterial colony forming units in the lymph node draining the site of BCG infection and the spleen. Mice exposed from 1 to 15 times to 1 MED of UV radiation showed a significant suppression in their DTH response to PPD compared with the unirradiated mice. At the same time, the number of bacterial colony-forming units in the lymph node and spleen of the UV-irradiated mice was greater than in control mice. With continued exposure to UVB, however, the DTH response recovered to a normal level, and there was no longer an increase in the number of viable bacteria in the lymphoid organs. These results indicate that early in the course of chronic UV irradiation, mice were impaired in their ability to mount a DTH response to BCG and to clear these bacteria from their lymphoid organs; later the mice recovered from these effects of UV, with continued treatment. A dose-response study using single doses of UV radiation indicated that a dose of 2.7 kJ/m2 suppressed the DTH response by 50%. Thus, exposure of mice to a single or multiple low doses of UV radiation prior to infection can interfere with systemic immunity to mycobacteria.     

A mathematical modeling approach to risk assessment for normal and anemic women chronically exposed to carbon monoxide from biomass-fueled cookstoves

In developing countries, the chronic exposure to carbon monoxide (CO) from biomass-fueled cookstoves may pose a significant health risk for women who use these stoves, especially for those with underlying clinical conditions that impair tissue oxygenation, e.g., anemia and coronary artery disease. CO concentrations measured in the vicinity of these cookstoves often exceed World Health Organization (WHO) indoor air guidelines for an 8-h average (9 ppm) and a 1-h maximum (26 ppm). Carboxyhemoglobin levels, reported infrequently because they are difficult to obtain, often exceed the WHO threshold of 2.5%. Despite this evidence, specific adverse effects have not yet been linked with chronic CO exposures in these women. Furthermore, anemia, which is prevalent in populations that use biomass fuels, could exacerbate the adverse effects of chronic CO exposure. Because of the difficulties inherent in conducting prospective studies to address this issue, we used a mathematical model to calculate the effects of reported CO levels and exercise on carboxyhemoglobin for women living in 1) Guatemalan villages at altitudes of 4,429-4,593 ft, and 2) coastal villages in Pakistan. In addition, we used the model to calculate the effects of CO exposures in women with moderate to severe anemia on specific physiological parameters (carboxyhemoglobin, carboxymyoglobin, cardiac output, and tissue Po(2)) at exercise levels representing the activities in which these women would be engaged. Our results demonstrate the efficacy of using a mathematical model to predict the physiologic responses to CO and also demonstrate that chronic anemia is a critically important determinant of CO toxicity in these women.     

Genotoxic studies in populations occupationally exposed to low doses of physical and chemical agents in Republic Croatia

In Croata Republic personnel occupationally exposed to radiation is examined with a method of chromosomal aberrations every 5 years, by the law. A population exposed to chemical factors is examined with a method of sister chromatid exchange as well as with micronucleus test. In the paper it is discussed a significance of various methods of examination of low doses of clastogenic and aneugenic factors on human genome.     

The characteristics of the realization of cytogenetic damage in mammalian and plant cells exposed to low doses of radiation]

A complicated character of the cytogenetic injury dependence upon radiation dose was revealed after low-level gamma irradiation of Vicia faba seedlings and Chinese hamster fibroblasts. The dependence was linear with low-level secondary exposure to 70 GeV protons. The authors discuss a threshold nature of induction of the cytogenetic damage repair responsible for a high outcome of damages under the effect of low-level gamma radiation.     

The effect of extremely low doses of the novel regulatory plant proteins

Searching and study on regulatory proteins, which can keep under control the scope of important processes as like as cell adhesion, proliferation, differentiation and morphogenesis, is an actual aim of the current biochemistry. Recently we have identified S-100 proteins in plants of following species: plantain (Plantago major L.), aloe (Aloe arborescens L.), and bilberry (Vaccinum myrtillus L.). Extraction and purification of S-100 proteins gotten from these plants were performed by the method we developed earlier for adhesion proteins of animal tissues. Homogeneity of the studied plant proteins was evaluated and confirmed by HPLC and SDS-electrophoresis in PAAG. Both, plant and animal proteins have appeared to be biologically active at extremely low doses. The tests were performed by adhesiometrical method in short-term tissue culture of mouse's liver in vitro. As a result it was established that the plant proteins insert a membranotropic effect being added in extremely low doses, corresponding to 10(-10)-10(-13) mg/ml. Keeping in mind that the plantain is well known remedy for wound protection and healing, in several experiments we studied the biological effect of plant S-100 proteins on animal cells. It was found that S-100 proteins obtained from plantain influences proliferation of human fibroblasts in vitro. It was found that after the treatment with this protein in low doses the cell growth rate increases essentially.     

The thyroid and adrenal glands in rats chronically exposed to an intense electric field

Two month-old male Long-Evans rats were exposed for 8 hours a day during 4 weeks to an ambient electric field (50 kV/m). The growth rate of electric field-exposed rats was identical to the controls' one. No significant effect of exposure was observed on the levels of various hormones: plasma and adrenal corticosterone; plasma TSH, ACTH, T3 and T4; adrenal epinephrine and norepinephrine. Histological studies of thyro?d and adrenals showed a normal appearance. In adrenals, the levels of various components and the activities of enzymes which have a role on stero?dogenesis were not modified. It is concluded that, in the present experiment conditions, the daily exposure of the rat to a severe electric field does not affect the normal state of thyro?d and adrenals.     

Cytogenetic monitoring of industrial populations potentially exposed to genotoxic chemicals and of control populations

Currently the most applied technique for monitoring biological effects of exposure to genotoxic chemicals in industrial workers is the measurement of chromosome aberrations in peripheral blood lymphocytes. In the Shell petrochemical complex in The Netherlands cytogenetic monitoring studies have been carried out from 1976 till 1981 inclusive, in workers potentially exposed to a variety of genotoxic chemicals, i.e. vinyl chloride, ethylene oxide, benzene, epichlorohydrin, epoxy resins. Average exposure levels to these chemicals were well below the occupational exposure limits. Results of these studies indicate that no biologically significant increase in the frequencies of chromosome aberrations in the exposed populations occurred compared with control populations. Our experience with this methodology has shown that the results of chromosome analyses are difficult to interpret, due to the variable and high background levels of chromosome aberrations in control populations and in individuals. It is concluded that the method is not sufficiently sensitive for routine monitoring of cytogenetic effects in workers exposed to the low levels of genotoxic compounds.     

The growth and development of Schistosoma mansoni in mice exposed to sublethal doses of radiation

The maturation of Schistosoma mansoni was studied in mice exposed to various sublethal doses of radiation. Although the treatment of mice with 500 rads of radiation prior to infection did not alter parasite maturation, doses in excess of 500 rads led to a reduction in worm burden. This could not be attributed to a delay in the arrival of parasites in the hepatic portal system. Worms developing in mice treated with 800 rads commenced egg-laying about 1 wk later than worms in intact mice, and the rate of egg deposition appeared to be lower in irradiated hosts. The data demonstrate that exposure of C57BL/6 mice to doses of radiation in excess of 500 rads impairs their ability to carry infections of S. mansoni. The findings do not support the hypothesis that primary worm burdens in the mouse are controlled by a host immune response.     

The effect of plant identity and the level of plant decay on molecular gut content analysis in a herbivorous soil insect

Plant roots represent an important food source for soil‐dwelling animals, but tracking herbivore food choices below‐ground is difficult. Here, we present an optimized PCR assay for the detection of plant DNA in the guts of invertebrates, using general plant primers targeting the trnT‐F chloroplast DNA region. Based on this assay, we assessed the influence of plant identity on the detectability of ingested plant DNA in Agriotes click beetle larvae. Six different plant species were fed to the insects, comprising a grass, a legume and four nonlegume forbs. Moreover, we examined whether it is possible to amplify DNA of decaying plants and if DNA of decayed plant food is detectable in the guts of the larvae. DNA of the ingested roots could be detected in the guts of the larvae for up to 72‐h post‐feeding, the maximum digestion time tested. When fed with living plants, DNA detection rates differed significantly between the plant species. This may be ascribed to differences in the amount of plant tissue consumed, root palatability, root morphology and/or secondary plant components. These findings indicate that plant identity can affect post‐feeding DNA detection success, which needs to be considered for the interpretation of molecularly derived feeding rates on plants. Amplification of plant DNA from decaying plants was possible as long as any tissue could be retrieved from the soil. The consumption of decaying plant tissue could also be verified by our assay, but the insects seemed to prefer fresh roots over decaying plant material.     

Hit rates and radiation doses to nuclei of bone lining cells from alpha-particle-emitting radionuclides.

Factors relating the local concentration of a bone-seeking alpha-particle emitter to the mean hit rate have been determined for nuclei of bone lining cells using a Monte Carlo procedure. Cell nuclei were approximated by oblate spheroids with dimensions and location taken from a previous histomorphometric study. The Monte Carlo simulation is applicable for planar and diffuse labels at plane or cylindrical bone surfaces. Additionally, the mean nuclear dose per hit, the dose mean per hit, the mean track segment length and its second moment, the percentage of stoppers, and the frequency distribution of the dose have been determined. Some basic features of the hit statistics for bone lining cells have been outlined, and the consequences of existing standards of radiation protection with regard to the hit frequency to cell nuclei are discussed.     

Probing lymphoma infiltration in spleen of AKR/J mice chronically exposed to electromagnetic fields for risk assessment – toward noninvasive modeling

Using the AKR/J mouse model, the potential of Raman spectroscopy for monitoring lymphoma in predisposed subjects is demonstrated by discriminating lymphoma infiltration in spleens; the relevance of different excitation profiles is shown. Under green excitation with optimal fluorescence bleaching, stronger DNA bands, intensity variations at amide‐III and phenylalanine bands, and the behavior of the 1606/1639 cm^–1 doublet correlate with tumorigenesis. Under red excitation, Raman fingerprints with multivariate models help to discriminate AKR/J‐mouse histological subtypes: Lymphoblastic lymphoma (LB) is found significantly distant from both separated lymphocytic lymphoma (LL) and healthy spleen; this agrees with histology since LB has well differentiated large lymphoma cells, while LL, with smaller cells similar to normal lymphocytes, usually cannot be discriminated from normal tissue without histoimmunoassays. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The influence of substance P central administration on ethanol intake in rats chronically exposed to alcohol

The influence of central substance P (SP) administration on alcohol intake and brain dopamine metabolism within mesocortico-limbic and nigrostiatal systems of rats exposed to ethanol, was studied. During 6 months, the rats consumed 15% ethanol solution instead of water. Central administration of SP (3 mcg/kg) decreased alcohol consumption by 41% in alcohol-preference animals. After long-term ethanol exposure ratios DOPAC/DA and HVA/DA were reduced in striatum and accumbens. SP in dose 3 mcg/kg increased content of DOPAC by 17% and HVA by 23% as well as DOPAC/DA by 9%, HVA/DA by 19% in accumbens. Whereas in striatum only increased DOPAC (28%) and HVA (29%) were observed as compared with saline-treated rats.     

Impaired angiogenic balance and suppression of tumorigenicity in HeLa cells chronically exposed to interferon-alpha

We have previously reported that IFNalpha-chronic treatment for 41 days induced a partial phenotype reversion on HeLa cells along with a down-regulation of HPV18 mRNA levels. However, tumorigenicity of these cells in nude mice was unchanged. Interestingly, after 1 year of IFNalpha-chronic exposition, HeLa cells failed to induce s.c. tumors when injected into nude mice. In such experimental conditions both HPV18 DNA integration pattern and viral DNA copy number present in HeLa cells remained intact in the nontumorigenic phenotype cells. As result of the treatment with IFNalpha, HeLa cells rendered more resistant to lysis mediated by activated natural killer cells in vitro. Furthermore, IFNalpha-chronic treatment was able to induce VEGF and decrease bFGF mRNA expression, suggesting a potential effect on the angiogenic behavior of these tumoral cells. Thus, long-term treatment of HeLa cells with IFNalpha can accomplish a reversion of the malignant phenotype by a sequential multistep mechanism, in which the antiangiogenic effect of IFNalpha could be one of the contributing events.     

The research of molecular manifestations of genome instability for individuals exposed to ionizing radiation in clinical significant doses

The oxidative status (effective contents of a superoxide anion-radical (O2*-) in assay with methyltetrazolium compound MTT and the contents of the reactive oxygen species (ROS) in assay with dichlorodihydrofluorescein diacetate (DCF-DA), the state of DNA structure and the nature of correlation connection between these indexes in cells of a peripheral blood for 26 healthy donors and 26 patients (including exposed in emergency on Chernobyl power plant), examined in many years after the radiation exposure in clinically significant doses are investigated. The method of polymerase chain reaction-single strand conformation polymorphism in the same cells out the search of mutation changes in 5-8 exons of TP53 gene for 10 patients was carried. It was established, that the state of the oxidative status for the patients is characterized by lowered (in relation to the donor control of equal age) contents O2*- in a general fraction of leucocytes and in mononuclear cells accordingly on 25% (p < 0.001) and 30% (p < 0.003) and ROS in mononuclear more, than on 40% (p < 0.008). During 5-hour incubation of cells the positive correlation connection (unidirectional changes) between indexes of DNA nativity and of oxidative status of leucocytes for 36.4% of the donors and 13.3% of the patients and in mononuclears for 38.5% of the donors and for 20% of the patients (p < 0.05) was detected. The general part of the individuals with a direct correlation in any of above named cell fractions among the donors in 2 times was higher (61.5%), than among the patients (26.7%, p = 0.038). The mutation replacements in nucleotide sequences of 5-8 exones of TP53 genes for the inspected patients were not detected. The obtained data indicate the existence of such changes in a metabolism and in systems of its regulation in nuclear blood cells after irradiation, which can be conditioned or can mirror a state of radiation-induced genome instability. The presence for the majority of the patients on the moment of the examination of several chronic diseases does not eliminate the connection of the detected biomolecular changes with these pathologies.