A new species of the genus <Emphasis Type="Italic">Pediasia</Emphasis> (Lepidoptera,Pyraloidea) from mountains of Transbaikalia

The new pyraloid moth species, Pediasia lidiella Streltzov et Ustjuzhanin, sp. n. (Lepidoptera, Crambidae), is described from the Udokan Range (northeastern Transbaikalia, Russia). The type material is deposited in the collection of the Zoological Institute, Russian Academy of Sciences (St. Petersburg).     

Specific features of adaptation of rats to chronic cold treatment

Permanent exposure of rats to four-week cold treatment at +4ºC for 24 h/day resulted in increased weights of the brown adipose tissue, adrenals, and spleen and had no effect on the levels of cortisol and corticosterone in the blood serum. Similar data were observed after exposure of rats to intermittent four-week cold treatment at +4ºC for 8 h/day. After short-term exposure of rats to intermittent cold treatment at +4ºC for 1.5 h/day, all indices studied were similar to those observed in intact animals.     

The role of IS-elements of Yersinia pestis (Lehmann, Neumann) in the emergence of calcium-independent mutations

Calcium independent mutants of two Yersinia pestis strains were studied. Insertions of IS100 element at three different sites of plasmid pCad within calcium dependence region were detected in Y. pestis EV, as well as two extensive deletions covering the whole region. It was shown that IS100 carries no HindIII sites. Novel IS element of Y. pestis designated IS101 was discovered in strain 358, in addition to IS100. It is distinguished by a slightly smaller size, HindIII site presence and high specificity of integration.     

Seasonal fluctuations in the potential soil capacity for nitrogen fixation

The nitrogenase activity of soils to which no energy-rich substances were added is low. This can be attributed to a low content of easily available organic substances. The potential activity of nitrogen fixation of the soils under study is different and changes with seasons. The highest ability for potential nitrogen fixation is displayed by soddy-calcareous and continuous-cultivated grey forest soils. The potential activity of nitrogen fixation in these soils correlates with the bacterial number on agar. Such a correlation is not observed in grey forest soils.     

NF-κB suppression provokes the sensitization of hormone-resistant breast cancer cells to estrogen apoptosis

The progression of breast cancer cells to estrogen-independent growth may be accompanied with the paradoxical cell sensitization to estrogen apoptotic action; however, the mechanism of this phenomenon is still unclear. In the present study, we have shown that the sensitization of hormone-resistant breast cancer cells to estrogen apoptotic action is accompanied with the gradual NF-κB suppression. Using the chemical inhibitors of NF-κB as well as the dominant-negative NF-κB constructs, we have proved the sufficiency of NF-κB inhibition for the sensitization of the resistant cells to estrogen apoptosis. Estradiol treatment results in the additional suppression of NF-κB, demonstrating the possible NF-κB involvement in the regulation of cell response to estrogens. Totally, the results presented suggest that the constitutive NF-κB suppression in the estrogen-independent cells may be considered as one of the factors resulting in a imbalance between pro- and anti-apoptotic pathways and enhancement in estrogen apoptotic action in the cells.     

Interaction of topotecan,DNA topoisomerase I inhibitor,with double-stranded polydeoxyribonucleotides. III. Binding at the minor groove

Interaction of topotecan (TPT) with calf thymus DNA, coliphage T4 DNA, and poly(dG-dC). poly(dG-dC) was studied by optical (linear flow dichroism, UV-vis spectroscopy) and quantum chemical methods. The linear dichroism (LD) signal of TPT bound to DNA was shown to have positive sign in the range 260-295 nm. This means that the plane of quinoline fragment (rings A and B) of TPT molecule form an angle lower 54 degrees with the long axis of DNA, and hence TPT molecule can not intercalate between DNA base pairs. TPT was established to bind to calf thymus DNA as readily as to coliphage T4 DNA whose all cytosines in the major groove were glycosylated at the 5th position. Consequently, the DNA major groove does not participate in TPT binding. TPT molecule was shown to compete with distamycin for binding sites in the minor groove of DNA and poly(dG-dC). poly(dG-dC). Thus, it was demonstrated for the first time that TPT binds to DNA at its minor groove.     

Spatial-typological differentiation of the ecosystems of the West Siberian Plain. Communication II: Underground phytomass,dead organic matter,and soil humus

Similarity was quantified for the ecosystems of the West Siberian Plain based on the masses of plant cover, dead organic matter, and underground organic matter (including soil humus) and the resultant matrix was subjected to cluster analysis. The results showed that the differentiation in the vegetation was nearly equally attributable to zonal gradients of thermal and moisture conditions (waterlogging), while the differentiation in the underground part of the ecosystems was predominantly under control of waterlogging. Intratypical differences in the underground part were due to zonal-subzonal heterogeneity in the gradients of thermal and moisture conditions, composition of vegetation, and flooding during snow-melt period. Such division did not entirely agree with subzonal division. The ecosystems were rather aggregated on the basis of the three abovementioned characteristics, with flooding and forest-forming species being the same.