Psychophysiological mechanisms of stress in subjects with different representation of activation

The EEG spectral power was calculated in 102 students aged 18-25 years in three experimental conditions (during the common educational process, immediately before and after an examination). Before the examination (stress situation), predominant activation of the right anterior cortical quadrant (the area related with negative emotions, according to R. Davidson, 1993) was revealed by the asymmetry coefficient of the beta rhythm. Subjects with low amplitude of the alpha rhythm (more activated) manifested not only emotional but also autonomic disturbances, while only emotional signs were pronounced in students with high alpha (less activated). Increase in the theta rhythm spectral power during stress and its decrease in the poststress period were observed in the less activated persons, which is considered to be a normal reaction to emotionally negative stimuli. On the contrary, in students with low alpha the theta rhythm power in the stress situation was decreased pointing to their emotional instability. In this group, as distinct from the first one, the beta 2 rhythm recorded in the right anterior cortical quadrant did not decrease in the poststress situation. Together with the observed theta rhythm, decrease in the left-hemisphere and bilateral prefrontal areas in the stress situation, this deviation testifies to a predisposition to the reactive depression of these subjects.     

Investigation of DNA complexes with histones F3 and F3+F2a2]

Characteristic viscosity, sedimentation constant and optical anisotropy were studied of the complexes formed between DNA and histone fractions F3 and F3+F2a2. The parameters mentioned continuously change with the increase of protein content within the complex. Analysis of experimental data shows that binding of a histone bads to a decrease of size and thermodynamic rigidity of the DNA molecule. On the basis of results obtained a model of F3 histone binding with DNA is suggested, amino acid sequence of this protein being taken into account. Comparison of behaviour of nucleohistones DNA+F3 and DNA+F1 studied previously testifies different way of binding of these histones to DNA.     

Emoxipin in reperfusion of ischemic myocardium in dogs: effects on infarct size and plasma creatine kinase activity

The effects of synthetic antioxidant emoxypine on infarct size and plasma creatine kinase (CK) activity was studied on open-chest anesthetized dogs with 180-min myocardial ischemia followed by reperfusion. Emoxypine (10 and 40 mg/kg) was injected intravenously, beginning since 120th min of coronary artery occlusion. Emoxypine (10 mg/kg) resulted in infarct size limitation and reduction in plasma CK activity. An increase in dose of emoxypine to 40 mg/kg largely attenuated its protective effect on infarct size. CK activity during post-ischemic reperfusion was even higher in emoxypine (40 mg/kg) group compared with control. Augmented CK leakage from irreversibly injured myocardium to plasma under these experimental conditions may be owing to preservation of microvascular integrity and improving of drainage of infarcted tissue exerted by emoxypine.     

The natural killer and fungicidal activity of the peripheral blood mononuclear cells in candidiasis

The activity of natural killers and the capacity of peripheral blood mononuclears for the extracellular killing of Candida cells in patients with different forms of candidiasis has been determined in the radiometric test with the use of targets labeled with 3H-uridine RNAase and in the fungicidal test. On the basis of the data thus obtained the conclusion has been made that in candidiasis changes in the activity of natural killers and fungicidal capacity depend on the severity of the disease and the stage of the process. Linear correlation between the activity of natural killers and fungicidal capacity in candidiasis patients at the stage of exacerbation and in healthy persons is absent.     

Multiplicity of site-specific DNA methyltransferases of theBstF5I restriction-modification system

A fragment located downstream of the genes for DNA methyltransferases ofBacillus stearothermophilus F5 (M.BstF5I-1 and M.BstF5I-2) was sequenced. The fragment contains a gene for another methylase, M.BstF5I-3, structurally and functionally similar to the N-terminal domain of M.FokI. Thus, in contrast to other restriction-modification systems, theBstF5I system includes three methylases, two being homologous to the individual M.FokI domains.