[Morpho-functional changes of the pyramidal neurons in various hippocampal areas after the ischemic postconditioning].

The aim of this study was to determine the effect of ischemic postconditioning (IP) on the viability of neurons in various hippocampal areas as well as on cytoplasmic activity of succinatedehydrogenase (SDH) in these cells in 30 male Mongolian gerbils (Meriones unguiculatus). Ischemic brain injury was induced by bilateral common carotid artery occlusion for 7 min. IP protocol comprised 3 cycles of 15 s of reperfusion/15 s of ischemia. After reperfusion for 48 h, the morphometric analysis was conducted, and SDH cytoplasmic activity was assessed using quantitative histochemistry in the pyramidal neurons of the hippocampal areas CA1, CA2, CA3, CA4. The experiment has demonstrated that 7-minute-long ischemia resulted in a significant decrease in the number of viable neurons in CA1 area (up to 24%) and in the CA3 (to 56%) of the hippocampus; besides, it lead to the elevation of SDH activity in the cytoplasm of the neurons in all the hippocampal areas as compared to that in sham-operated animals. The application of IP significantly increased the number of viable neurons in CA1 (up to 52.9%, P<0,01) and in CA3 areas of the hippocampus(up to 88%, P<0,05), and it was accompanied by reduction of SDH activity in surviving neurons in all the hippocampal areas.

Activity of succinate dehydrogenase in the neocortex and hippocampus of Mongolian gerbils with ischemic and reperfusion brain injury.

We analyzed changes in activity of SDH, one of the most important enzymes of the Krebs cycle, in the cytoplasm of hippocampal and cortical neurons of Mongolian gerbils (Meriones unguiculatus) at the early and delayed reperfusion period after global brain ischemia. The data indicate that SDH activity in pyramidal neurons of various hippocampal areas and in neurons of II, III and V layers of cerebral cortex after 7-min forebrain ischemia depends on both the localization of these neurons and duration of the postischemic reperfusion. SDH activity in neurons significantly increased on days 2 and 7 after reperfusion.

[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).

[Application of dermal fibroblasts in complex treatment of patients with trophic ulcers of venous etiology].

The authors have analyzed the results of an experimental-clinical investigation devoted to studying the efficiency of local treatment of trophic ulcers at the stage of healing using transplantation of dermal allogenic fibroblasts. The method was proved to accelerate epithelization and to shorten the time of preparing to operations for correction of the venous blood flow.

Pathomorphological peculiarities of damage to hair cells of the organ of corti in experimental sensorineural hearing loss.

Pathomorphology of the organ of Corti was studied on models of acute and chronic sensorineural damage to the acoustic analyzer. Peculiarities of hair cell degeneration, necrosis, and apoptosis in the organ were studied by light and scanning electron microscopy. The type of pathomorphological substrate in abnormalities of the organ of Corti depends on the intensity of the destructive exposure, but not on the nature of otopathological factors.

Local neurotoxicity of epidural clofelin.

Morphological and quantitative histoenzymological changes in neurons of dog spinal cord and spinal ganglion were studied in acute and chronic experiments with epidural administration of 0.01% clofelin. No morphofunctional changes were revealed after bolus injection of clofelin in a single dose of 6.5 mg/kg. After administration of clofelin in a daily dose of 15 microg/kg for 14 days permeability of capillaries in the nervous tissue decreased at the site of injection, but increased in intact areas. Compensatory changes in energy supply to neurons manifested in activation of aerobic and anaerobic oxidation. Sufficient level of nucleic acids synthesis confirms qualitative validity of nervous cells. Epidural clofelin did not cause dystrophy and necrosis in neurons of the spinal and spinal ganglion.

Morphofunctional changes in spinal cord neurons after epidural lidocaine.

Morphofunctional and histoenzymological changes in spinal cord neurons of mongrel dogs were studied after epidural administration of isobaric 2% lidocaine solution. Control animals received epidural 0.9% sodium chloride. The results obtained from these studies provide evidence for the absence of pathological structural-metabolic changes in nerve tissue after treatment with lidocaine. The occurrence of certain morphofunctional rearrangements in spinal cord neurons were typical of animals of both the experimental and control groups. The changes recorded varied within the limits of physiological variation and provided evidence predominantly of the functional response of these nerve tissue structures to epidural injections of both sodium chloride and lidocaine.

[Morphological and functional changes in spinal ganglion neurons after epidural clopheline administration]. / Morfofunktsional'nye izmeneniia neironov spinnomozgovykh gangliev pri épidural'nom vvedenii klofelina.

The aim of this chronic experimental study performed in 16 dogs was to determine the effect of epidural infusion of 0.01% clopheline solution on the morphological and histoenzymological characteristics of spinal ganglion neurons. Daily infusions of clopheline at the dose of 15 mg/kg for 14 days caused a decrease in capillary permeability in the spinal ganglia at the injection site and its increase in the intact areas. This finding suggests the changes in the activity of the microcirculatory bed with a disturbed interaction in capillary-neuron system. Analysis of morphometric parameters has demonstrated the presence of some functional and reversible dystrophic changes in spinal ganglion neurons, which were associated with epidural infusion of both clopheline and isotonic solution of sodium chloride. Determination of the activity of oxidation-reduction enzymes, which reflect the course of aerobic and anaerobic processes in spinal ganglion neurons, has shown no significant differences between the groups of animals infused with or isotonic solution of sodium chloride. In conditions of chronic experiment no significant variations were found in RNA content in ganglionic cells at and outside the sites of infusion of clopheline and of isotonic solution of sodium chloride.

[General pathological aspects of the hair cells damage in spiral organ]. / Obshchepatologicheskie aspekty povrezhdeniia voloskovykh kletok spiral'nogo organa.

The information concerning general pathological changes in hair cells of the spiral organ is reviewed. The conditions for the onset, morphological picture of dystrophy, necrosis, apoptosis typical for hair cells in respect to structural and functional features of the sensory epithelium of the spiral organ are outlined. Nonspecific morphological changes of the spiral organ neuroepithelium after the action of damaging agents of different origin (such ototoxic drugs as aminoglycoside antibiotics and others, intensive acoustic impacts, ageing of the acoustic analyzer) are emphasized.

[Local neurotoxicity of isobaric 2% solution of lidocaine at epidural administration]. / Mestnaia neirotoksichnost' izobaricheskogo 2% rastvora lidokaina pri épidural'nom vvedenii.

The morphological and histoenzymological changes in the spinal neurons and spinal ganglia of dogs were analyzed after epidural administration of a 2% solution of lidocaine in acute and chronic experiments. In the control group the animals were given epidural infusions of 0.9% saline. The results obtained have shown the absence of pathological structural and metabolic changes in the nervous tissue after lidocaine injection. Certain signs of morpho-functional reorganization were noted in the spinal neurons of animals in both experimental and control groups. The registered changes were found to vary within the physiological fluctuation limits and are rather indicative of the functional reaction of the nervous tissue structures in question to the epidural injections of either saline or lidocaine.

[Evaluation of the local neurotoxicity of lidocaine following epidural administration]. / Otsenka mestnoi neirotoksichnosti lidokaina pri épidural'nom vvedenii.

The morphological and histoenzymological changes in spinal neuron and in the spinal ganglia of outbred dogs were analyzed in the epidural administration of 2% solution of lydocaine. The results showed a lack of pathological or structural-and-metabolic changes in the nervous tissue. The morpho-functional reshaping occurring in the spinal cord cells and in the spinal ganglia was in line with that when the 0.9% solution of sodium chloride was in use. The registered changes ranging within the physiological deviations' limits witnessed to a functional reaction of the studied nervous-tissue structures to epidural drugs' injections.

[Morpho-functional changes of the spinal cord neurons after epidural administration of lidocaine]. / Morfofunktsional'nye izmeneniia v neironakh spinnogo mozga posle epidural'nogo vvedeniia lidokaina.

The analysis of morphological and histoezymological changes of spinal cord neurons has been performed in outbred dogs following epidural infusion of isobaric 2% lidocaine solution. In the control group the animals received epidural infusion of 0.9% saline. The results obtained indicate the absence of pathological structural and metabolic changes in the nervous tissue after lidocaine application. Certain signs of morpho-functional reorganization were noted in spinal cord neurons of animals in both experimental and control groups. The registered changes were found to vary within the physiological fluctuation limits and are rather indicative of the functional reaction of the studied structures of the nervous tissue to the epidural injections of either saline and lidocaine.

Protective effect of calcium channel blocker verapamil on morphological and functional state of hair cells of the organ of corti in experimental kanamycin-induced ototoxicity.

The protective effect of verapamil against acute ototoxic sensorineural damage produced by intraperitoneal injections of kanamycin (50 mg/kg daily for 14 day) was studied on rats. The functional (otoacoustic emission), histological, and physiological methods proved the protective effect of daily injections of calcium channel blocker verapamil (2 mg/kg) on the state of hair cells of the organ of Corti.

Effect of epidural infusion of isobaric 2% lidocaine on spinal cord ganglionic neurons.

We analyzed morphological and histoenzymologic changes in spinal cord ganglionic neurons of mongrel dogs caused by epidural infusion of isobaric 2% lidocaine. Lidocaine produced no pathological structural and metabolic alterations in the nervous tissue. Both epidural infusion of 0.9% NaCl and lidocaine produced some morphofunctional rearrangements in spinal ganglionic neurons. These alterations were within the limits of physiological norm and probably attested to functional response of the examined nerve tissue structures to epidural infusion.

Effect of epidural injection of prosidol with clonidine on the state of spinal cord and spinal ganglion.

Morphological and histoenzymatic changes in cells of the spinal cord and spinal ganglia after epidural injection of a combination of prosidol with clonidine were studied on dogs. No pathological structural and metabolic changes in the nervous tissue were found after combined treatment with the test drugs. Higher activity of nucleic acids and alkaline phosphatase in spinal neurons and spinal ganglion in experimental animals in comparison with those in controls indicates intensification of protein synthesis and active transport in the endothelium of nerve tissue capillaries, which is a favorable factor.

[Analysis of morphological changes in the spinal cord and ganglia of dogs after epidural administration of prosidol, clopheline and prosidol-clopheline combination]. / Analiz morfologicheskikh izmenenii spinnogo mozga i spinno-mozgovogo gangliia sobak posle épidural'nogo vvedeniia prosidola, klofelina i kombinatsii proosidola s klofelinom.

Experiments were carried out on 22 mongrel dogs (12-20 kg). Group 1 consisted of 5 dogs to which prosidol in a dose of 0.65 mg/kg was injected epidurally; group 2, 5 dogs, clofelin (6.5 micrograms/kg) epidurally; group 3, 5 dogs, prosidol (0.65 mg/kg) + clofelin (6.5 micrograms/kg) epidurally. Control groups were as follows: 1) 5 intact dogs; 2) 2 dogs epidurally injected with 0.9% normal saline. Analysis of the spinal cord and ganglia in control groups showed no dystrophic changes in neurons. After epidural injections of prosidol, clofelin, or both only solitary cells with degenerative changes were detected or none at all. Nissle granules were evenly distributed in the cytoplasm of anterior and posterior spinal horn neurons in all control and experimental animals. The majority of ganglious cells in control and experiment had the nucleus and nucleolus. Hence, morphological analysis showed that epidural injection of prosidol, clofelin, and a combination of both caused no degenerative or necrobiotic changes in the anterior and posterior spinal horn neurons and in ganglious cells of spinal ganglia.

[Enzymatic activity in spinal cord neurons after epidural administration of clopheline in dogs]. / Aktivnost' fermentov v neironakh tkani spinnogo mozga posle épidural'nogo vvedeniia klofelina u sobak.

Time course of the major enzymes (SDH, LDH, GPDHcyt, GPDHmit, AP) and protein synthesis (DNA, RNA) in spinal neurons and spinal ganglia after epidural injection of clofelin were studied in an acute experiment on dogs. No physiological or neurological disorders or depriming effect of clofelin on the major enzymatic systems and protein synthesis in nervous tissue of dogs were detected. Increased activity of AP in the spinal white and gray matter is worthy of note, which indicates intensification of active transport in spinal capillary epithelium after epidural injection of clofelin.