Experimental study of combined effect of actoprotectors and radioprotectors in radiation injury

Combined treatment of mice and dogs with actoprotector bimethyl and radioprotector indralin suppressed radioprotective action of the latter, the surveillance being decreased from 83.3 to 14.3% in dogs and from 70.3 to 5% in mice. At the same time vasodynamic action of indralin (increase of artherial pressure up to 30% from a reference level) did not change.     

Yield and quality of forage maize (<i>Zea mays</i> L.) with different levels of subsurface drip irrigation and plant density

The scarcity of water in arid and semiarid regions of the world is a problem that every day increases by climate change. The subsurface drip irrigation (SDI) and changes in population density of plants are alternatives that can be used to make a sustainable use of water. Therefore, the objectives of this study were to determine the combination that allows for an increased corn performance and efficient use of water without losing the quality of forage. Three different irrigation levels were applied through a system of a SDI at three different densities of forage maize plants in an arid region. The results demonstrated that by applying different levels of water, either enough or lack of soil moisture is created, which is directly reflected in crop yield, and its determining variables such as green forage and dry matter yield, and nutritional quality. The irrigation level to a 100% of potential evapotranspiration (PET), at a density of 80000 plants/ha, increased yield of green forage to 57664 kg/ha; crude protein was 8.59%, while the rest of the quality parameters decreased. This study allowed to conclude that the irrigation level was the major factor in the response of the crop.     

Estradiol binding to maxi-K channels induces their down-regulation via proteasomal degradation

Estrogens exert their biological action via both genomic and non-genomic mechanisms. Proteins different from classical estradiol receptors are believed to mediate the latter effects. Here we demonstrate that the maxi-K channel functions as an estrogen-binding protein in transfected HEK293 cells. Whole-cell maxi-K channel currents and protein expression were attenuated by exposure to either 17alpha- or 17beta-estradiol. This effect was dose-dependent for 17beta-estradiol at concentrations ranging from 10 nm to 1 microm, while 17alpha-estradiol inhibited channel expression only at 1 microm. These effects were mediated by direct low affinity binding of estradiol to the maxi-K channel but not to its accessory beta1-subunit, as revealed by cell membrane estradiol binding assays. However, specific binding of estradiol to the channel was facilitated by the presence of the beta1 subunit. Addition of MG-132, a blocker of proteasomal degradation, stabilized channel expression. These data suggest that channel down-regulation is mediated by estrogen-induced proteasomal degradation, similar to the pathway used for estrogen receptor degradation. Membrane expression of endogenous maxi-K channels in cultured vascular smooth muscle cells was also attenuated by prolonged exposure to 17alpha- and 17beta-estradiol. Thus our studies demonstrate that estrogen binds to maxi-K channels and may directly regulate channel expression and function. These results will have important implications in understanding estradiol-induced effects in multiple tissues including vascular smooth muscle.     

Recombinant human interleukine-1beta (betaleukine) usage for acute radiation sickness of severe degree treatment at canines

Recombinant human interleukine-1beta (betaleukune) of Institute of especially pure biopreparation production had been examined as a treatment means at acute radiation disease of severe degree at dogs. Dogs were irradiated totally in doses above the LD95/45. Betaleukine had been administered s/c twice in day in 15 min - 2 h after irradiation. All the dogs, including control ones, received in acute period 8-24/26 days after irradiation antibiotics ampicillin and gentamycin i/m. Betaleukine increased 45 day-survival by 37% at 4 Gy and by 25% at 4.4 Gy. The effect correlated with more high level of nadir and more early beginning the leucocyte number restoration. We observed the regularity at all the dogs that received betaleukine as survived as died, but in the latter case in a lesser degree certainly. Besides the noticed character of leucocytes kinetics had been repeated at all the blood cell types but in the different degree. It had been concluded on the base of these observations that betaleukine acts on hemopoietic stem cells preferentially. The effect is in preventing death of a stem cells part, or in stimulating survived stem cells proliferation, or in both together. Betaleukin can be regarded as a suitable means of urgent pathogenic therapy at radiation accidents.     

Assessment of the status of biological health of the population of tundra Nentsy inhabiting northwestern Siberia from data on analysis of autoantibodies and lipoproteins from blood donors

As a result of large-scale nuclear explosion on Novaya Zemlya test site (1955-62) the Tundra Nentsy population of Yamal-Nentsy autonomous region (YNAR) fell under constant influence of incorporated radioactive isotopes (137Cs and 90Sr). Therefore, it is very important to analyze a possible spectrum of diseases of Tundra Nentsy population. We have developed recently a new method for determination of concentrations of all main fraction and subfraction of lipoproteins (LP, 30 parameters) in human sera using small-angle X-ray scattering, and a general mathematical model to describe LP composition in human blood. The analysis of the 30 parameters characterizing fine spectrum of LPs in 374 YNAR natives showed that only approximately 10% of the donors are normal, while the indices for approximately 90% of the test subjects fall into the range of different pathologies (3-8% incidence in normal population, according to epidemiological studies). Moreover, we found that approximately 41% of European and approximately 56% of Tundra Nentsy have high level of autoantibodies to DNA and cardiolopine like the same for autoimmune diseases patients.     

Regulation of 1-dehydrogenation and 20 beta-reduction of ketosteroids by microorganisms]

Regulation of two microbiological processes--1-dehydrogenation and 20 beta-reduction of ketosteroids--was studied using several exogeneous quinones which (a) stimulated 1-dehydrogenation and (b) inhibited the accompanying reaction, the reduction of 20-ketogroup of the steroid molecule. The least active compounds were benzoquinones. The best regulators are 1,4-naphthoquinone, 1,2-naphthoquinone, and 7-methoxy-1,2-naphthoquinone. Possible mechanism of the action of naphthoquinones on Mycobacterium globiforme is discussed.     

Effect of several compounds on the process of reduction of the 20-keto group of corticosteroids by a culture of Mycobacterium globiforme

The effect of certain metabolites produced in the metabolism of carbohydrates, proteins and fats on the reduction of the 20-keto group in a number of corticosteroids (prednisone, prenisolone, 6 alpha-methylprednisolone) was studied with the culture of Mycobacterium globiforme. The metabolites and inhibitors of the respiration chain were found to stimulate the 20 beta-reduction of a steroid molecule. The inhibitor of oxidative phosphorylation, 2,4-dinitrophenol, inhibited the reduction of the 20-keto group in a steroid.