Том 42, № 6 (2016)

With the advancement of contemporary techniques for studies of high-frequency electroencephalograms (EEGs), possible contamination of the EEG with the electromyogram (EMG) of pericranial muscles has raised more and more concern. The aim of the present study was to demonstrate if certain EEG correlates of mental activities can be revealed in a high-frequency scalp EEG in spite of EMG contamination. Nineteen healthy women who performed similar test tasks before and after cosmetic injections of Dysport in various facial regions for reduction of the activity of facial muscles took part in the study. Inductions of emotional states with different valences, memory storing, and extraction of verbal information were used in the test tasks. The default state of rest was examined as well. During performance of the tasks, parallel registrations of the EEG from the scalp surface (19 channels) and EMG from several facial muscles (6 channels) were carried out. Changes in the spectral power in β₂ and low γ frequency bands (18–40 Hz) in EEG- and EMG-derivations after Dysport injections were analyzed. Changes in the spectral power in the same bands in pairwise comparisons for the test tasks before and after Dysport injections were also analyzed separately. It was demonstrated that Dysport injections lead to reduction of the EMG power in areas of the injections and to reduction of EEG power in the frontal and temporal derivations. However, the EEG-correlates revealed when comparing different test tasks remained qualitatively invariable as for after and before Disport injections. These facts confirm that EMG makes a noticeable contribution to the electric activity registered from the scalp in the frequency ranges greater than 18 Hz. At the same time, one can see that at least in certain experimental situations the influence of EMG does not make impossible identification of EEG-correlates of mental activity with EEG registration from the head surface at least in the β₂ and low γ frequency bands (18–40 Hz).

The article analyzes event-related potentials in the Go/NoGo test of patients with schizophrenia and schizotypal personality disorder in relation to healthy subjects. Differences identified in the group of patients with schizophrenia are consistent with previous studies and indicate disruption in processes associated with different stages of visual information processing and executive functions. Specific features of brain activity in patients with schizotypal personality disorder were significantly less pronounced and presumably pointed to changes in the processes of attention redistribution and action monitoring. The results agree well with the clinical symptoms of schizophrenia and schizotypal personality disorder, so that this technique can be considered a possible additional diagnostic criterion for these disorders.

Effects of different visual conditions on the vertical posture maintenance were compared in subjects standing on a firm or compliant surface. These visual conditions included a motionless visual environment (MVE), eyes-closed condition (EC), and a virtual visual environment (VVE). The VVE consisted of two planes: the foreground and background. The foreground displayed a room window with adjacent walls, and the background was represented by an aqueduct with the adjacent landscape. The VVE was destabilized by inducing either the cophased or the antiphased relation between the foreground of the visual scene and the body sway. We evaluated changes in the amplitude spectra of two elementary variables calculated from the trajectories of the plantar center of pressure (CoP) displacements in the anteroposterior and lateral directions, namely, the trajectories for the center of gravity projections on the support (the CG variable) and the differences between the CoP and CG trajectories (the CoP–CG variable).The CG trajectory was considered as a controlled variable, and the difference between the CoP and CG trajectories were considered as a variable related to the body acceleration and reflecting changes in the resultant stiffness in ankle joints. The rootmean-square (RMS) values for the spectra of both variables calculated from the body sway in the anteroposterior direction in standing on a firm support decreased proportionately with antiphased relation between the foreground and the body sway and increased with the cophased relation, compared with the RMS calculated for the MVE conditions. RMS for the spectra of the CG variable in the cophased relation were nearly the same, as in standing with eyes closed (EC), while the RMS for the spectra of the CoP–CG variable were significantly less than with EC. The body sway during standing on a compliant support significantly increased in both the anteroposterior and the lateral directions under all visual conditions. RMS for the spectra of both variables with EC increased considerably higher than in the cophased relation. Furthermore, the RMS for the spectra of the CG variable calculated from the body sway in the lateral direction on a compliant support was substantially higher in the antiphased relation than in the cophased relation, whereas the RMS for the spectra of the CoP–CG variable under both conditions had similar values. The analysis of body sway and the results under some visual conditions have shown that the amplitude characteristics of the CG and CoP–CG variables changed not always proportionately with the passage from standing on a firm support to a compliant support. It is suggested that the found disproportion of changes in these two variables is probably associated with the contribution of another additional factor to the process of postural control, the passive elastic component of musculo-articular stiffness generated by fascial-tendon tissues.

We studied the polymorphism of uncoupling protein genes (UCP1, UCP2, and UCP3) and the FTO gene in 28 football players (team of masters) and compared the results with the data obtained in nonathletes. All these genes encode the proteins that are involved in the regulation of body mass. However, we observed an increased percentage of the carriers of “thrifty” allele of the UCP3 gene; the alleles frequency of other studied genes showed the same tendency. This finding can be partially explained by the fact that the organism of an athlete needs to spare energy. Spearman rank correlation analysis showed that there is a significant correlation between the UCP1 and FTO genes and the elastic component of explosive strength of leg muscles. No correlations were found with the body composition and fat distribution (except for the fat distribution in the pelvic area). The UCP2 gene correlated with the parameters of respiratory functions. The UCP3 gene correlated with the rate of energy production in ramp test and the ergometric parameters of efficiency. It was also found that the high rate of uncoupling of oxidation and phosphorylation in muscles results in an increase in the total energy consumption rate, but also improves the ergometric parameters of efficiency and intensity of muscle work corresponding to the anaerobic threshold. The obtained data were analyzed in the context of the possible role of uncoupling proteins in homeostasis during intense physical activities.

The individual, age-related, and professional variations of the sensitivity to a stable hypoxic stimulus have been studied in healthy male subjects. Hypoxia was induced using the method of rebreathing with modifications. An algorithm have been suggested for detecting the point when the oxygen saturation level of blood oxyhemoglobin started to decrease in comparison with the initial value upon gradual reduction of the gas in the inhaled air. We have found that age-related differences in the oxyhemoglobin saturation with oxygen under the conditions of hypoxia were nonsignificant in subjects at the ages from 21 to 50 years. At the same time, the average sensitivity to hypoxia in the subjects performing their professional duties in a modified atmosphere (hyperoxia) was lower than in those of the conventional professions.

Elevated concentrations of Nt-pro-BNP were revealed in 11% of apparently healthy subjects aged 19–24 years and 22% of middle-aged (34–55 years) subjects. An increase in Nt-pro-BNP blood concentration was detected in 90% of patients with metabolic syndrome. Elevated levels of Nt-pro-BNP in peripheral blood occur with age. Higher concentrations of the peptide were revealed in women. Inhibition of lymphocytes proliferation and differentiation accompanied by increasing concentration of Nt-pro-BNP in blood is associated with a deficiency of the IL-2 level due to increased IL-10 concentration. Immunosuppressive effect of IL-10 declares itself at the level of innate immune reactions as a decrease in blood counts of naive CD45RA+ T lymphocytes, natural killer cells, T cells with adhesion receptor (CD56+) and adhesion receptor ligand (CD62L+). To prevent a loss of the intercellular pool, the effect of Nt-pro-BNP is activated. No statistically significant correlations between the increased Nt-pro-BNP concentration in blood and the content of serum IgM, IgG, IgA, IgE, IL-6, TNF-α, IFN-γ, CEC C1q, or С3d, as well as glucose, hemoglobin, transferrin, iron, or free fatty acids were revealed in apparently healthy subjects.

The review addresses the effect of microgravity on the endothelial cells, an important mechanosensory element of the cardiovascular system that is known to undergo functional changes in space flight. The chalanges that arise in performing space flight experiments are presented, as well as approaches used to simulate microgravity effects in vitro. The role of cytoskeletal elements as the putative gravity sensors in the cells is demonstrated. The changes in the expression of adhesion molecules that may underlie the mechanisms of gravity sensing by endothelial cells are described. The possible reasons for the discrepancies between the results obtained, such as the differences between the cell lines and experimental design, the variation in time of cultivation, and the specific spaceflight related factors, are analyzed.