Dynamics of the spectral-coherent characteristics of the human EEG in healthy subjects and brain pathology

EEGs of 15 healthy subjects and 30 patients in early period after surgical ablation of tumours with basal localization, were investigated by means of monitor "Neuro-1" which allows to obtain in continuous regime characteristics of EEG dynamics according to power spectra and reveal the characteristics of intercentral relations of electrical brain processes by coherence and phase shifts. In healthy subjects in the period of transition from wakefulness to drowsiness highly coherent beta-rhythm (16-18 Hz) was revealed, preceeding typical picture of drowsiness and sleep. Study of the patients shows that certain characteristics of coherence and phasic shifts have an important prognostic value. Conclusion is made that for estimation of the functional state of healthy subjects during transition from wakefulness to drowsiness and of patients in early postoperative period the data on spectra of coherence are most informative.     

Expression in Escherichia coli of DNA coding for human tumor necrosis factor

The variants of expression in Escherichia coli of artificial DNA coding for human tumor necrosis factor, an important immune modulator with selective cytotoxic action on a number of transformed cell lines have been described. The DNA was placed under control of either phage M13 promoter of gene for main coat protein or tandem of pair of E. coli tryptophane promoters. It has been shown that E. coli cells harbouring plasmids described with artificial TNF gene provide good level of protein biosynthesis. The protein has been purified by anion exchange chromatography near to homogeneity and used for preparation of monoclonals. As result three hybridomas effectively produced high affinity monoclonal anti-TNF antibodies have been obtained and characterized.     

Synthesis, cloning, and expression of artificial genes, coding antigenic determinants of the foot-and-mouth virus substrain A22]

Chemical-enzymatic synthesis and cloning in Escherichia coli of double-stranded DNAs, coding for simple and complex antigenic determinants of foot-and-mouth disease virus (FMDV) strain A22, have been carried out. The simple antigenic determinants are a part of the viral coat protein VP1 (amino acid sequence 131-152 or 131-160) whereas the complex antigenic determinants comprise additionally the amino acid sequence 200-213 of VP1 linked to N-terminus of simple antigenic determinants through a tetrapeptide spacer Pro-Pro-Ser-Pro. Recombinant DNAs containing genes for antigenic determinants of FMDV fused with C-terminus of gene for human tumor necrosis factor (hrTNF) have been constructed. Expression of the hybrid genes and properties of the proteins coded were studied. All recombinant proteins were shown to interact specifically with polyclonal antibodies both against hrTNF and FMDV strain A22. The recombinant proteins produced by bacteria are perspective for study as a vaccine against FMDV.     

Isolation and characterization of cardiac progenitor cells from myocardial right atrial appendage tissue

Resident cardiac stem cells, known as “cardiogenic progenitor cells” (CPCs), are a heterogeneous population of immature cells residing in the myocardium and capable of self-renewal and differentiation into cardiomyocyte-like and vascular-like cells. CPCs are usually isolated by long enzymatic digestion of heart tissue and selection with stem cell markers. However, long exposure to enzymatic digestion and the small size of a myocardial sample significantly hinder acquiring a large number of viable cells. To avoid these problems, we developed a method based on CPC growth ex vivo and subsequent immunomagnetic selection.     

Seasonal Variations in the Structure of an Anoxygenic Phototrophic Bacterial Community from the Meromictic Lake Trekhtsvetnoe (Kandalaksha Bay,White Sea)

Microbiology - The community of anoxygenic phototrophic bacteria (APB) from the water column of the meromictic Lake Trekhtsvetnoe (Kandalaksha Bay, White Sea, Russia) was studied in March 2012 and...     

Intracerebral EEG functioning as a reflexion of the systemic brain organization in norm and pathology

The authors summarized the EEG findings and defined the nature of intercentral EEG relationships in different functional states of healthy subjects and patients with organic cerebral pathology based on coherence analysis. The EEG features typical of healthy subjects were identified: an anterior-posterior gradient of the mean coherence and the character of cortical-subcortical relationships in the anterior cerebral structures. Right- and lefthanded subjects showed the frequency and regional differences in EEG coherence, which reflected, mainly, specific intracortical relationships. Development and regression of pathologic signs in right- and lefthanded patients with organic brain lesions are thought to be determined by these differences. As distinct from cortical pathology, lesions of regulatory structures (diencephalic, brainstem, and limbic) were shown to produce more diffuse changes in intercentral relationships with a tendency to reciprocity. Intercentral relations, including their interhemispheric differences, varied with changes in the functional state of healthy subjects (increase and decrease in the level of functioning). A certain time course of changes in intercentral relationships was also revealed in patients with organic brain lesions during recovery of their consciousness and mental activity. Changes in the dominance of activity of individual regulatory structures are considered to be one of the most important factors that determine the dynamic character of EEG coherence.     

Expression and properties of human TNF peptide fragments

The tumor necrosis factor (TNF) is a proinflammatory cytokine that plays a pivotal role in the regulation of the human immune system. Studies of the TNF functional topography are a challenging task in bioengineering. We have produced genes encoding the peptides D1 (3–30), D2 (31–85), D3 (86–114), and D4 (115–157), which correspond to isolated fragments of the informational structure of TNF. These genes were expressed in E. coli cells at a high level in a soluble form. We have shown that hybrid proteins SD2 and SD4 tend to form high-molecular aggregates, which can be destroyed by urea treatment. Purified peptides D1, D3, and D4 possess a similar secondary structure with dominating beta-structural elements. The analysis of the biological activity of these peptides has shown that they do not exhibit cytotoxic properties on L929 murine fibroblasts. The simultaneous addition of D1 with full-length TNF results in the concentration dependent suppression of TNF activity.     

Position Effect Variegation: Role of the Local Chromatin Context in Gene Expression Regulation

Molecular Biology - Position effect variegation (PEV) is a phenomenon wherein the expression level of a gene strongly depends on its genomic position. PEV can be observed when a gene is moved via a...     

Effect of tumor necrosis factor DNA on immune response to DNA immunization against herpes simplex virus

A study was made of the adjuvant effect of the mouse tumor necrosis factor alpha (mTNF alpha) on DNA immunization against the herpes simplex virus type 1 (HSV1). The HSV1 gD gene (pDNAgD) served as an immunogen; mTNF alpha or its gene cloned in an eukaryotic expression vector (pDNAmTNF) were used to modulate the immune response. Double immunization with pDNAgD led to a sixfold increase in the in vitro T-cell response, a high (1:2000) titer of anti-HSV1 antibodies (including virus-neutralizing antibodies), an increase in IgG2a/IgG1 (suggesting a shift of the immune response to the Th1 type), and no change in CD4/CD8 T-cell ratio. A single injection of mTNF alpha along with inactivated HSV1 allowed a twice higher antibody titer and a fourfold higher T-cell response as compared with immunization with HSV1 alone. Double immunization with both pDNAgD and pDNAmTNF increased the titer of anti-HSV1 antibodies and the T-cell response by factors of 8 and 1.5, respectively, as compared with immunization with pDNAgD alone. However, the protective effect was significantly lower with the two plasmids than with pDNAgD (73 vs. 100%). Thus, DNA immunization with pDNAgD induced both B- and T-cell responses and completely protected mice from a lethal doze of HSV1. The adjuvant properties of mTNF alpha and pDNAmTNF need further investigation.