Neurophysiological aspects of the regulation of the head’s position in the normal state and left- and right-sided forms of spasmodic torticollis

We have studied the spatiotemporal distribution of coherent EEG links in 10 healthy right-handed subjects under the conditions of comfortable wakefulness with a straight position of the head and with the head voluntarily turned to fixed left and right positions. The computations were made separately in each standard range of EEG frequencies (Δ, θ, α, and β). The results were compared with the data obtained during studies of right-handed patients with right-sided (RS, n = 9) and left-sided (LS; n = 8) forms of spasmodic torticollis (ST). It has been shown that, upon a voluntary right turn of the head, the number of strong and moderate coherent EEG links in healthy subjects increases considerably more than upon a left turn. This may be accounted for by the greater functional importance of the control of the right part of the visual space as the area of manipulation of the dominant hand. In patients with RS ST, the number of intra- and interhemispheric strong and moderate coherent EEG links increased in all four frequency ranges, as compared to healthy subjects, upon the right turn of the head. In patients with LS ST, the spatial structure of the bioelectric potential field of the brain is less reorganized upon the voluntary left turn of the head as compared to the level of coherent EEG links in healthy subjects. Presumably, this phenomenon reflects a stronger insufficiency of neurophysiological mechanisms of postural control and compensation for its disturbances in patients with the LS form of ST, which results in a more severe disability as compared to patients with right-sided ST.     

Capacities of diagnostic volumetric multislice spiral computed tomography in the diagnosis of gastric cancer

In the period 2009 to 2010, diagnostic multislice spiral computed tomography (MSCT) was carried out in 49 patients with gastric cancer. The efficiency of dynamic MSCT in detecting a tumor and determining its locoregional extent was evaluated. The results of dynamic MSCT were compared with those of postoperative histological examination. The possibility of detecting gastric cancer by dynamic MSCT was ascertained to depend on the depth of tumor invasion and to average 29, 71, 72, and 77% for T1, T2, T3, and T4, respectively. Dynamic MSCT showed a correlation between the frequency of metastatic lesion and the sizes of lymph nodes (r = 0.54; p = 0.0001) and their number (r = 0.82; p < 0.0001).     

Effect of individual peculiarities on formation of preference of ethanol in female and male Wistar rats

Individual characteristics of animal behavior can serve a prognostic parameter of predisposition to use of alcohol. The goal of the work was to study dynamics of formation of preference of alcohol at early stages in the process of forced alcoholization in male and female rats as well as the accompanying changes in behavior parameters. For 3 months, the rats were submitted to the forced alcoholization with 10 % ethanol. Each week the rats were tested in the "two-glass trial". Individual peculiarities of all animals were evaluated prior to, after 6 weeks, and after the end of the experiment with aid of the "open field test" and "Suok-test". Results showed that the male rats demonstrating by the end of the experiment the significantly higher level of the alcohol preference, at the initial stages of the forced alcoholization demonstrated the significantly lower preference as compared with the remaining ones. These rats also showed the lower levels of the motor and exploratory activities before alcoholization as compared with control. On the contrary, the individuals that by the end of the experiment did not differ from control by the level of the alcohol preference demonstrated prior to alcoholization in the "Suok-test" the higher anxiety level. In female groups, no statistically significant differences were observed both in parameters of the motor and exploratory activities and in the anxiety level in both tests. Thus, in male rats, the prognostic parameter predicting formation of the abuse can serve the degree of alcohol preference at the initial stages.     

Establishment of a chimeric, replication-deficient influenza A virus vector by modulation of splicing efficiency

Segment 8 of the influenza A virus codes for two proteins (NS1 and NS2/NEP) via splicing. Here, we developed a viral vector expressing a cytokine or chemokine instead of the interferon antagonist NS1. To achieve both the desired genetic stability and high transgene expression levels, NS2/NEP mRNA splicing efficacy had to be fine-tuned by modification of splicing elements. Expression levels of secreted foreign proteins could be further enhanced by fusing the N-terminal 13 amino acids of NS1 with an IgK-derived secretion signal peptide. Thus, the first start codon was used for translation initiation of both NS2/NEP and the foreign protein.     

Disulfide-stabilized helical hairpin structure and activity of a novel antifungal peptide EcAMP1 from seeds of barnyard grass (Echinochloa crus-galli)

This study presents purification, activity characterization, and (1)H NMR study of the novel antifungal peptide EcAMP1 from kernels of barnyard grass Echinochloa crus-galli. The peptide adopts a disulfide-stabilized α-helical hairpin structure in aqueous solution and thus represents a novel fold among naturally occurring antimicrobial peptides. Micromolar concentrations of EcAMP1 were shown to inhibit growth of several fungal phytopathogens. Confocal microscopy revealed intensive EcAMP1 binding to the surface of fungal conidia followed by internalization and accumulation in the cytoplasm without disturbance of membrane integrity. Close spatial structure similarity between EcAMP1, the trypsin inhibitor VhTI from seeds of Veronica hederifolia, and some scorpion and cone snail toxins suggests natural elaboration of different functions on a common fold.     

The possibilities for partial rehabilitation of the integrative activity of the brain in patients in a vegetative state

An integrated neuroreconstructive approach to stimulating the pathogenetic mechanisms of a vegetative state developed due to a severe traumatic brain injury (TBI) is suggested. It has been shown that a faster and more pronounced therapeutic effect, compared with conventional therapies, could be achieved through the application of transtimpanal chemical vestibular dereception and transcranial micropolarization. The results of neurophysiological in-depth examination in dynamics have shown that over time interregional cortical interactions become more intense, “rigid,” and “tight” in patients with a vegetative state, while the temporal-parietal-occipital areas begin to dominate in the organization of these interactions in the cortex of both hemispheres. It is assumed that the vestibulothalamic tract, owing to its anatomical location, appears to be the least vulnerable under the conditions of brain stem dislocation due to a severe TBI. As a result, vestibular afferentation appears to become a predominant kind of afferentation for generating interregional cortical interactions. A pathological functional system develops on the basis of this afferentation, blocking other functional systems in the damaged brain. The suggested therapies significantly reduce the amount of vestibular afferent inputs and open a possibility for restoring more effective afferent interactions. This significantly facilitates the functioning of the brain as a multimodal analyzer.     

Does Land-Use Intensification Decrease Plant Phylogenetic Diversity in Local Grasslands?

Phylogenetic diversity (PD) has been successfully used as a complement to classical measures of biological diversity such as species richness or functional diversity. By considering the phylogenetic history of species, PD broadly summarizes the trait space within a community. This covers amongst others complex physiological or biochemical traits that are often not considered in estimates of functional diversity, but may be important for the understanding of community assembly and the relationship between diversity and ecosystem functions. In this study we analyzed the relationship between PD of plant communities and land-use intensification in 150 local grassland plots in three regions in Germany. Specifically we asked whether PD decreases with land-use intensification and if so, whether the relationship is robust across different regions. Overall, we found that species richness decreased along land-use gradients the results however differed for common and rare species assemblages. PD only weakly decreased with increasing land-use intensity. The strength of the relationship thereby varied among regions and PD metrics used. From our results we suggest that there is no general relationship between PD and land-use intensification probably due to lack of phylogenetic conservatism in land-use sensitive traits. Nevertheless, we suggest that depending on specific regional idiosyncrasies the consideration of PD as a complement to other measures of diversity can be useful.     

Choline‐mediated modulation of hippocampal sharp wave–ripple complexes in vitro

The cholinergic system is critically involved in the modulation of cognitive functions, including learning and memory. Acetylcholine acts through muscarinic (mAChRs) and nicotinic receptors (nAChRs), which are both abundantly expressed in the hippocampus. Previous evidence indicates that choline, the precursor and degradation product of Acetylcholine, can itself activate nAChRs and thereby affects intrinsic and synaptic neuronal functions. Here, we asked whether the cellular actions of choline directly affect hippocampal network activity. Using mouse hippocampal slices we found that choline efficiently suppresses spontaneously occurring sharp wave–ripple complexes (SPW‐R) and can induce gamma oscillations. In addition, choline reduces synaptic transmission between hippocampal subfields CA3 and CA1. Surprisingly, these effects are mediated by activation of both mAChRs and α7‐containing nAChRs. Most nicotinic effects became only apparent after local, fast application of choline, indicating rapid desensitization kinetics of nAChRs. Effects were still present following block of choline uptake and are, therefore, likely because of direct actions of choline at the respective receptors. Together, choline turns out to be a potent regulator of patterned network activity within the hippocampus. These actions may be of importance for understanding state transitions in normal and pathologically altered neuronal networks.

     

Bacillus subtilis var. amyloliquefaciens biosynthesis of extracellular protease possessing coagulase activity and formed under conditions of limiting the nitrogen sources in the medium

An exocellular protease having the activity of coagulase was synthesized by Bacillus subtilis var. amyloliquefaciens when the growth medium contained no nitrogen sources. The removal of a nitrogen source from the medium was found to induce the synthesis of exoproteases by washed bacterial cells. Protein as a sole source of nitrogen in the medium inhibited rather than induced the biosynthesis of proteases possessing the activity of coagulase by the cells. The production of exoproteases with the coagulase activity was inhibited when a mixture of amino acids was used as a sole nitrogen source.     

Production of monoclonal antibodies to the prion protein and their characterization

Antibodies to the prion protein (PrP), particularly, monoclonal antibodies, are necessary tools in the diagnostics and study of prion diseases and potential means of their immunotherapy. For the production of monoclonal antibodies, BALB/c mice were immunized by a recombinant bovine PrP. Three stable hybridomas producing antibodies of IgM class were prepared. The antibodies were bound to PrP in a solid-phase enzyme immunoassay and immunoblotting. The epitope mapping accomplished with the use of synthetic peptides showed that an epitope located in region 25–36 of PrP corresponds to one antibody, and epitopes located in region 222–229, to the other two. The antibodies to fragment 222–229 purified by affinity chromatography recognized with a high specificity conglomerates of a pathogenic prion in the brain tissue of cows suffering from spongiform encephalopathy. Thus, in nontransgenic mice, PrP-specific monoclonal antibodies were produced, useful in studies and diagnostics of prion diseases.