Activity of the Sympathoadrenal System during Adaptation of the Human Body to Living Inside an Isolated Object

Changes in the activity of the sympathoadrenal systems of three healthy volunteers during their adaptation to living and working inside an isolated facility were studied. The living conditions and the professional activities of the subjects examined simulated those typical of cosmonauts during long-term spaceflight. The activities of the sympathoadrenal and serotonin- and histaminergic systems were assessed through relative rates of synthesis, inactivation, and metabolism. The subjective tolerance to the complex of experimental conditions was evaluated with a feeling–activity–mood test. It was shown that, while a human lives and works inside an isolated facility, adaptive changes in some parameters of the sympathoadrenal and histaminergic systems proceed through specific temporal phases. Among the rates of synthesis, inactivation, and metabolism, the most significant phase-related changes were observed in parameters of the metabolic activity. Apparently, the metabolic activity of the liver and other tissues affecting the blood levels of catecholamines and other biogenic amines is a leading mechanism of those phase-related changes in transmitter systems that are evident during human adaptation to complicated living conditions. For many of the metabolic parameters tested, rates of change were either independent of other experimental conditions or showed a less significant dependence on conditions than on phase-related factors.     

Effect of priming of multipotent mesenchymal stromal cells with interferon γ on their immunomodulating properties

Multipotent mesenchymal stromal cells (MSCs) are widely used for cell therapy, in particular for prophylaxis and treatment of graft-versus-host disease. Due to their immunomodulatory properties, MSCs affect the composition of lymphocyte subpopulations, which depends on the immunological state of the organism and can change in different diseases and during treatment. Administration of MSCs is not always effective. Treatment of MSCs with different cytokines (in particular IFN-γ) leads to enhancement of their immunomodulatory properties. The aim of this study was to investigate sub-populational alterations and activation markers in lymphocytes (activated and non-activated) after interaction with MSCs and MSCs pretreated with IFN-γ (γMSCs) in vitro. Lymphocytes were co-cultured with MSCs or γMSCs for 4 days. The proportion of CD4⁺ and CD8⁺ expressing CD25, CD38, CD69, HLA-DR, and PD-1 and distribution of memory and effector subsets were measured by flow cytometry after co-cultivation of lymphocytes with MSCs or γMSCs. The distribution of lymphocyte subpopulations changes during culturing. In non-activated lymphocytes cultured without MSCs, decrease in the proportion of naïve cells and increase in the number of effector cells was observed. That could be explained as activation of lymphocytes in the presence of serum in culturing medium. Co-culturing of lymphocytes with MSCs and γMSCs leads to retention of their non-activated state. Activation of lymphocytes with phytohemagglutinin increases the number of central memory cells and activates marker expression. Interaction with MSCs and γMSCs prevents activation of lymphocytes and keeps their naïve state. Priming with IFN-γ did not induce MSCs inhibitory effect on activation of lymphocytes.     

Initial data on biological activity of taiga–steppe soils in the lower reaches of the Kolyma River

Microbiological and enzyme activities of extrazonal taiga-steppe soils in the lower reaches of the Kolyma River have been studied for the first time. Contrary to north-taiga cryometamorphic soils, predominating in the area, microbial cenoses under herb–sedge petrophytic and grass–sagebrush–herb thermophytic steppes are characterized by features typical for arid soils. The saturation of the soil profile with microorganisms is greater, and the development of actinomycetes is more intensive. The enzyme complex is characterized by high activity of dehydrogenases.     

In vitro selection of cell-internalizing 2′-modified RNA aptamers against <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis>

Infectious diseases caused by bacterial or viral agents represent the major cause of human pathogenesis and mortality worldwide. A development of novel antibacterial therapeutics and diagnostic tools is a very acute task. The use of DNA and RNA aptamers targeted to certain bacteria could be a promising solution to this problem. Here, we propose a new protocol of selection of 2′-fluoro RNA aptamers capable to internalize into bacterial cells. Using whole-cell SELEX against Pseudomonas aeruginosa, enriched 2′-fluoro RNA library was obtained, and its sequencing and data analysis were fulfilled. It was found that the central region of predominating aptamer sequence is identical to the fragment of P. aeruginosa rRNA. A possibility of internalizing of this aptamer into bacterial cells is shown. It is hypothesized that aptamers could be internalized more effectively as heterodimeric complexes.     

Protein methylation in mitochondria

Many proteins are modified by posttranslational methylation, introduced by a number of methyltransferases (MTases). Protein methylation plays important roles in modulating protein function and thus in optimizing and regulating cellular and physiological processes. Research has mainly focused on nuclear and cytosolic protein methylation, but it has been known for many years that also mitochondrial proteins are methylated. During the last decade, significant progress has been made on identifying the MTases responsible for mitochondrial protein methylation and addressing its functional significance. In particular, several novel human MTases have been uncovered that methylate lysine, arginine, histidine, and glutamine residues in various mitochondrial substrates. Several of these substrates are key components of the bioenergetics machinery, e.g., respiratory Complex I, citrate synthase, and the ATP synthase. In the present review, we report the status of the field of mitochondrial protein methylation, with a particular emphasis on recently discovered human MTases. We also discuss evolutionary aspects and functional significance of mitochondrial protein methylation and present an outlook for this emergent research field.     

鼠李糖脂的表面化学和生物合成及其在垃圾堆肥中的应用展望

鼠李糖脂是生物表面活性剂中一类非常重要而应用广泛的微生物发酵产物,在环境污染修复中需求量越来越多。针对近十年来国内外对鼠李糖脂生物表面活性剂的研究,较系统地总结了其化学结构、性质、生物合成机理及产量调节方法,及大规模生产鼠李糖脂的基础研究工作,并对其在城市生活垃圾堆肥中的应用做了展望。     

Effect of chitosan on tobacco mosaic virus(TMV) accumulation,hydrolase activity,and morphological abnormalities of the viral particles in leaves of N. tabacum L. cv. Samsun

The effect of chitosan on the development of infection caused by Tobacco mosaic virus(TMV) in leaves of Nicotiana tabacum L. cv. Samsun has been studied. It was shown that the infectivity and viral coat protein content in leaves inoculated with a mixture of TMV(2 μg/mL) and chitosan(1 mg/mL) were lower in the early period of infection(3 days after inoculation), by 63% and 66% respectively, than in leaves inoculated with TMV only. Treatment of leaves with chitosan 24 h before inoculation with TMV also caused the antiviral effects, but these were less apparent than when the virus and polysaccharide were applied simultaneously. The inhibitory effects of the agent decreased as the infection progressed. Inoculation of leaves with TMV together with chitosan considerably enhanced the activity of hydrolases(proteases, RNases) in the leaves, in comparison with leaves inoculated with TMV alone. Electron microscope assays of phosphotungstic acid(PTA)-stained suspensions from infected tobacco leaves showed that, in addition to the normal TMV particles(18 nm in diameter, 300 nm long), these suspensions contained abnormal(swollen, "thin" and "short") virions. The highest number of abnormal virions was found in suspensions from leaves inoculated with a mixture of TMV and chitosan. Immuno-electron microscopy showed that "thin" virus particles, in contrast to the particles of normal diameter, lost the ability to bind to specific antiserum. It seems that the chitosan-induced activation of hydrolases stimulates the intracellular degradation of TMV particles and hence hydrolase activation may be considered to be one of the polysaccharide-mediated cellular defense mechanisms that limit virus accumulation in cells.     

Molecular evolution of mammalian lactate dehydrogenase-A genes and pseudogenes: association of a mouse processed pseudogene with a B1 repetitive sequence

A mouse genomic clone containing a lactate dehydrogenase-A (LDH-A) processed pseudogene and a B1 repetitive element was isolated, and a nucleotide sequence of approximately 3 kb was determined. The pseudogene and B1 element are flanked by perfect 13-bp repeats, and the B1 sequence starts at 14 nucleotides 3' to the presumptive polyadenylation signal of the pseudogene. The nucleotide sequences of the LDH-A genes and processed pseudogenes from mouse, rat, and human were compared, and a phylogenetic tree was constructed. The rate and pattern of nucleotide substitutions in the LDH-A pseudogenes are similar to previously reported results (Li et al. 1984). The average rate of nucleotide substitutions in the LDH-A pseudogenes is 4.3 X 10(- 9)/site/year. The substitutions of C----T and G----A are most frequent, and A----G substitutions are relatively high. The rate of synonymous substitutions in the LDH-A genes is 5.3 X 10(-9), which is not significantly higher than the average rate of 4.7 X 10(-9) for 35 mammalian genes. The rate of nonsynonymous substitutions in the LDH-A genes is 0.20 X 10(-9), which is considerably lower than the average rate of 0.88 X 10(-9) for 35 mammalian genes. Thus, the mammalian LDH-A gene appears to be highly conserved in evolution.      

Recent history of Lake Ladoga

Combined paleolimnological investigations of a 1.8 m sediment core from the deepest north-western part of Lake Ladoga show stratigraphic changes in granulometric and chemical composition, organic matter content, diatom species composition and chlorophyll a concentration. The sediment accumulation rate was calculated and 5 stages of lake history over the last 4 000 years were described. Changes in lake environment were mainly caused by changes in climate and lake water balance. Human impact on the lake was also traced.