[The association between oxidative stress markers and clinical course of chronic cerebral ischemia].

Authors studied 360 patients with different stages of chronic cerebral ischemia (CBI), including 180 patients followed-up for 12 months after the first examination, who were stratified into two groups with regard to disease course - favorable (stable) and unfavorable (progressive or with acute episodes of cerebral blood circulation disturbance). Oxidative stress markers were evaluated by the level of lipid- (malonic dialdehyde) and protein - (carbon products of protein oxidation, the level of plasma SH-groups, the accumulation of the products of deep oxidation of proteins) oxidation. Along with indicators of oxidative stress, we evaluated the binding capacity of albumin using fluorescent probe K-35. Initial level of these markers and their concentrations after the copper ion induced oxidation of the plasma were determined. The highest increase in oxidative stress indicators was seen in patients with acute episodes. Authors identified significant differences in these indicators in the groups of patients with different clinical variants of CBI course as well as qualitative and quantitative diagnostic criteria of unfavorable course and risk of stroke. Our findings suggest that the imbalance of oxidative-antioxidative system contributes to the course of CBI. Prediction of unfavorable course of CBI determines the timeliness of adequate treatment.

[Relationship between clinical characteristics and primary and secondary products of lipid and protein peroxidation].

Recent studies showed that activation of free oxygen radicals and the resulting stress play a key role in the development of brain vascular lesions related to hypertensive disease and atherosclerosis leading to chronic cerebral ischemia. To recall, activation of oxidative stress precedes chronic cerebral ischemia and stroke. Therefore, detection of stress markers may be a step toward the development of a new method for the identification of groups at high risk of stroke among patients with the unfavourable course of cerebral ischemia. This study was focused on the relationship between lipid and protein peroxidation products and clinical manifestations of the disease.

[The free-radical processes and antioxidant therapy in brain ischemia].

A role of the free-radical processes and disturbances of oxidative-restorative blood homeostasis and nervous tissue in the pathogenesis of brain ischemic pathology and other diseases are reviewed. Attention is focused on the search for optimal ways of pharmacological correction of oxidative stress in the schemes of complex treatment of chronic blood circulation insufficiency and on the necessity of combined application of several antioxidants with different mechanisms of action which reciprocally potentiate each other. Experimental and clinical suppositions of the use of a-lipoic acid as one of the most studied antioxidant in the treatment of brain ischemia as well as the results of own studies on the preparation berlition which contains a-lipoic acid used in the neuroprotective therapy of chronic brain ischemia for correction of free-radical processes are discussed.

Evaluation of the resistance of blood plasma to oxidative stress by oxidizability of proteins and lipids during metal-catalyzed oxidation.

A new approach for the evaluation of oxidizability of proteins and lipids in the same sample of blood plasma was proposed. We tested a method for evaluation of metal-catalyzed oxidation of fibrinogen by the formation of bityrosine cross-links during oxidation detected by the increase in fluorescence at 415 nm. A correlation was revealed between parameters of oxidizability estimated by this marker and carbonyl derivatives (dinitrophenylhydrazine method). Oxidizability of total proteins from whole plasma was compared with oxidizability of plasma lipids (marker malonic dialdehyde). Study of these parameters in patients with coronary heart disease showed that the proposed experimental approach allows us to divide the sample into several subgroups differing in the resistance to oxidative stress. These data can be used for diagnostic and prognostic purposes.

Regulatory effects of Ribotim on functional activity of neutrophils and wound healing during experimental burn trauma.

We studied the effects of ribonucleic immunotropic preparation Ribotim obtained from the thymus on functional activity of peripheral blood neutrophils and wound healing after burn trauma. Immunotherapy normalized immunological parameters, attenuated demarcation inflammation in burn wound, and promoted epithelialization of the wound surface preserving skin structures.

Effects of low-molecular-weight thymic RNA on T cell-dependent antibody formation.

We proposed a method for isolation of low-molecular-weight RNA from mammalian thymus. Physicochemical properties and regulatory activity of these RNA in immunological test of T cell-dependent antibody formation were evaluated.

[Autolytic degradation of RNA; the effect of various factors on the dynamics of the process]. / Avtoliticheskaia degradatsiia RNK: vliianie razlichnykh faktorov na dinamiku protsessa.

As found earlier RNA preparations from different eukaryotic tissues followed by thorough deproteinization contain "masked" RNases, that cause autolytic degradation. The present paper indicates that the autolytic degradation of a deproteinized preparation of RNA from Ehrlich's cells by gel electrophoresis under denaturated conditions and ultracentrifugation in sucrose gradient is submitted by definite regularities and is essentially dependent on the concentration change of Mg2+, Na+, K+, NH4+ ions and also GTP and guanosine. It is proposed the activity of "masked" RNases is the manifestation of ribozyme properties of RNA molecules. Similar processes may take place in processing and catabolism of RNA in vivo.

[Autolytic degradation of RNA: effect of autolysates and native preparations of pre-mRNA on the level of transcription in model systems in vitro and in vivo]. / Autoliticheskaia degradatsiia RNK: vliianie autolizatov i nativnykh preparatov pre-mRNK na uroven' transkriptsii v model'nykh sistemakh in vitro i in vivo.

The effects of autolysates and native preparations of pre-mRNA on RNA biosynthesis in isolated rat liver nuclei in vitro and in mouse liver cells in vivo were studied. The correlation between the experimental data obtained in both test systems and the differences in the effects of native pre-mRNA preparations and their autolysates suggest that the autolytic degradation in vitro is a reflection of processes occurring in eukaryotic cells. The feasible role and significance of such fragments in the general scheme of transcription regulation are discussed.

[Discovery of "masked" ribonucleases in highly purified preparations of RNA]. / Obnaruzhenie "skrytykh" ribonukleaz v vysokoochishchennykh preparatakh RNK.

It was found that RNA preparations isolated with the help of various inhibitors of RNAses from different eukariotic tissues, followed by thorough deproteinization contain particular ribonucleases ("masked" RNAses). These RNAses were supposed to be connected with RNA molecules and are not active. They may be activated by changes of RNA molecule conformation. Apparently the "marked" RNAses can take part in (a) processing of large precursor RNA molecules; (b) regulation of gene expression by means of specially cut RNA fragments.

[Abolishment of allogeneic inhibition of colony formation with the aid of various RNA classes]. / Otmena allogennoi ingibitsii kolonieobrazovaniia s pomoshch'iu razlichnykh klassov RNK.

The authors analysed the capacity of various temperature fractions of RNA isolated from the spleen of donors of the bone marrow cells (of mice C57BL/6I) and recipients--hybrids (CBA X C57BL/6I) F1 to abolish the depression of colony formation in the nonsyngenous organism. In the administration of bone marrow cells of mice of parental genotype C57BL/6I of the irradiated recipients F1 there is observed a sharp depression of the number of colony forming units in the spleen F1. This depression can be eliminated by preliminary incubation of the bone marrow cells of mice of parental genotype with a 63 degrees fraction of the recipient's RNA. Preliminary inculation of the bone marrow cells of mice of parental genotype with 85 degrees and cytoplasmic fractions of recipient's RNA led to a partial restoration of colony formation only. The 45 degrees and 55 degrees RNA fractions of the recipient's RNA produced no restoring action. None of the temperature RNA fractions of the RNA of donor bone marrow cells were capable of abolishment of the colony formation depression in the nonsyngenous organism. It is supposed that restoration of the colony forming capacity in the nonsyngenous organism was connected with the activity of matrix RNA of the 63 degrees fraction obtained from the recipient's spleen.