Comparison of reactive EEG changes and fMRI characteristics of brain health based on multivariate statistics

To gain a deeper insight into the relationship between the electrogenesis and oxygenation of the brain, fMRI and EEG reactions to identical functional loads (opening of the eyes and right- and left-hand fingering) were compared in 11 young right-handed healthy subjects with statistical techniques. Changes in power, frequency and coherent EEG parameters obtained by 18-channel monopolar recording were compared with values of + BOLD-fMRI response, calculated for 18 corresponding cortical areas on the basis of application of the "virtual cap" by the original algorithm. In reactive changes of both hemodynamic and bioelectrical parameters, sets of independent factors were identified, which were regarded on the basis of their topography as specific (localized in the cortical representation ofa relevant analyzer) and nonspecific (diffuse and similar under different functional loads). Specific component dominated in the fMRI response, whereas non-specific component was characteristic of the EEG reaction. The similar topography of reactive fMRI and EEG factors under normal conditions, confirmed by the correlation analysis, reflects the multilevel character of the systemic organization of the brain activity, visualized, in particular, in the sagittal projections of the individual fMRI images. Each of the reactive EEG factors included all of the EEG quantitative characteristics. EEG coherence, which dominated among other parameters (with a local increase in the cortical representation of a relevant analyzer and a diffuse decrease in the areas of the influence of the regulatory structures) displayed the highest correlation with hemodynamic responses of the brain.     

Long-term preservation of DNA in aqueous solutions in the presence of the chemical analogues of microbial autoregulators

he fact of long-term preservation of the physicochemical properties of DNA molecules in aqueous solutions in complexes with methylresorcinol, hexylresorcinol, and tyrosol, the chemical analogues of microbial autoregulators (d₁ factors) from the group of alkylhydroxybenzenes (AOB), was established. Compared to the control variants of storage of aqueous DNA solutions, the AOB influence consisted in the sum of correlating effects: the prevention of DNA degradation (according to spectrophotometric parameters) and the preservation of its viscous characteristics and electrophoretic mobility. The initial DNA properties were preserved to the greatest degree in the presence of hexylresorcinol, the compound with the longest alkyl radical. Possible mechanisms of the protective action of alkylhydroxybenzenes in relation to DNA are discussed, namely, the prevention of its hydrolysis due to isolation from the aqueous environment and maintaining DNA stability in the dormant forms of microorganisms.     

Species composition and distribution of ichthyoplankton in the Sea of Japan in Autumn 1995 and 2001

It was determined on the basis of data on species composition and distribution that ichthyoplankton in the Sea of Japan within the exclusive economic zone of Russia was represented in October 1995 and September 2001 by 13 species. Anchovy Engraulis japonicus and saury Cololabis saira were the most abundant and widely distributed. The area of distribution of anchovy larvae and juveniles was great, but was restricted mostly to subtropical waters. The larvae and juveniles of saury were captured to the west of the frontal interface in the waters of subarctic structure. The character of the distribution of early progeny suggests that the spawning of saury in summer ran in the economic zone of Russia. The early progeny of saury was absent in the zone of Japan filled with subtropical waters. Because of peculiarities of spawning strategy of the spawners, the regions of distribution and maximum concentrations of their larvae and juveniles did not overlap and were associated with different water masses. The species composition of larvae and young fishes collected with the Maruchi-Ami fry net was more diverse in comparison to the fish-egg net IKS-80. The parameters of the catches of both nets on conversion to the filtered volume of water were comparable only in the regions with increased concentrations of larvae and juveniles. The fry net was not very efficient for calculating recruitment in the dispersed autumn aggregations.     

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.     

Spatiotemporal deep imaging of syncytium induced by the soybean cyst nematode <Emphasis Type="Italic">Heterodera glycines</Emphasis>

Parasite infections cause dramatic anatomical and ultrastructural changes in host plants. Cyst nematodes are parasites that invade host roots and induce a specific feeding structure called a syncytium. A syncytium is a large multinucleate cell formed by cell wall dissolution-mediated cell fusion. The soybean cyst nematode (SCN), Heterodera glycines, is a major soybean pathogen. To investigate SCN infection and the syncytium structure, we established an in planta deep imaging system using a clearing solution ClearSee and two-photon excitation microscopy (2PEM). Using this system, we found that several cells were incorporated into the syncytium; the nuclei increased in size and the cell wall openings began to be visible at 2 days after inoculation (DAI). Moreover, at 14 DAI, in the syncytium developed in the cortex, there were thickened concave cell wall pillars that resembled “Parthenon pillars.” In contrast, there were many thick board-like cell walls and rarely Parthenon pillars in the syncytium developed in the stele. We revealed that the syncytia were classified into two types based on the pattern of the cell wall structures, which appeared to be determined by the position of the syncytium inside roots. Our results provide new insights into the developmental process of syncytium induced by cyst nematode and a better understanding of the three-dimensional structure of the syncytium in host roots.     

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.     

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.