[Activity of lactate dehydrogenase in the brain cortex and hippocampus of Mongolian gerbils after global ischemia and reperfusion injuries].

Cerebral ischemia results in severe derangements of energy metabolism in the nervous tissue including activation of glycolytic pathway. Activity of cytosolic lactate dehydrogenase (LDH) in the specific brain structures remains unclear. The recent study was aimed at investigation into the LDH activity in the cytoplasm of both hippocampal and cortical neurons in Mongolian gerbils (Meriones unguiculatus) at different durations of reperfusion after global ischemia. Analysis showed that the activity of LDH in pyramidal neurons of various hippocampal areas and neurons of II, III and V cortical layers after 7-minute forebrain ischemia depended on both localization of the neurons and duration ofreperfusion. In general, the changes in postischemic cytosolic LDH activity include significant decrease in the LDH activity 2 days after reperfusion with varying degree of recovery on day 7 of reperfusion.

[Morpho-functional changes of hippocampal CA1 area in Mongolian gerbils after ischemic postconditioning].

The aim of this study was to determine the effect of ischemic postconditioning on hippocampal CA1 neuronal survival and cytoplasmic activity of lactate dehydrogenase (LDH) in the gerbil model of cerebral ischemia-reperfusion injury. Ischemia was induced by bilateral common carotid artery occlusion (for 7 min) in male Mongolian gerbils (Meriones unguiculatus). Ischemic postconditioning protocol comprised 3 cycles of 15 s reperfusion/15 s ischemia. After 48 h of reperfusion, CA1 neuronal death was detected by Nissl staining and the cytoplasmic LDH was demonstrated histochemically in CA1 area of the hippocampus with a quantitative cytophotometric assessment of the enzyme activity. The results have shown that 7 min ischemia resulted in a significant decrease in the number of viable neurons (up to 24%) in the CA1 area of hippocampus; in addition, it reduced the activity of LDH in these neurons (from 0.260 +/- 0.009 to 0.190 +/- 0.006 relative units). The application of ischemic postconditioning significantly increased the number of viable neurons (up to 52.9%, P < 0.01) in the CA1 area of hippocampus, and it was accompanied by an increase in the activity of LDH (0.240 +/- 0.008 relative units, P < 0.001).

[Comparison of photodynamic effect with respect to human and rabbit erythrocytes].

Parameters of photoinduced lysis are studied for human and rabbit erythrocytes (photosensibilizer--Radachlorin, the light source--Shuttle HeNe lazer, lambda = 633 nm). The higher sensitivity to irradiation is revealed for rabbit erythrocytes. Treatment of erythrocytes with trypsin showed the surface proteins in human cells to produce a protective effect. Trypsynization of rabbit erythrocytes produced the opposite action--the rate of photohemolysis increased. Results of the study indicate the differences in sensitivity to the photoinduced lysis of erythrocytes of different species and participation of erythrocytes proteins in the effect of photohemolysis.

[The replacement of defects and prevention of dental arch deformities in complete destruction of the crowns in subjects of various ages]. / Zameshchenie defektov i profilaktika deformatsii zubnykh riadov pri polnom razrushenii koronok u lits razlichnogo vozrasta.

The authors necessitate careful handling of the dental roots and consider it necessary that indications for the use of pin constructions be widened; they suggest original modifications of such designs and analyze the results of treatment of 176 patients. Examinations of 2,664 adolescents have revealed various dentition defects in 23.2 +/- 1.5%, these defects leading to deformations. Orthodontic treatment and prostheses are necessary to prevent these deformations.