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Biomedical subjects

N A Onishchenko

Publications and source records attributed to N A Onishchenko.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

[A comparative study of the dynamics of deep burns healing in using medullary allogenic fibroblast-like mesenchymal stem cells from bone marrow immobilized on biodegrading membranes or taken from cultural plastic].

Transplantation of suspention of allogenic fibroblast-like mesenchymal stem cells (AFMSC) of the bone marrow and AFMSC immobilized on the biodegradable membrane (BM) stimulates healing of deep burn wounds compared to control (without cell transplantation) because these cells produce biologically active substances into the wound. AFMSC immobilized on BM activate repair processes in the wounds earlier. This may be due to their higher functional activity created in the monolayer by adequate intercellular interactions. To avoid complications caused by low diffuse properties of BM (protein precipitation), BM should be removed from the surface of the burn wound maximum 3 days after its application.

Animals↗
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[Influence of cell therapy and alimentary correction on the condition of microcirculatory system in experimental dyslipidemia].

A comparative analysis of the impact of cell therapy (allogenic fetal liver cells, stem cells of autologic bone marrow) on lipid homeostasis, microcirculatory disturbances and structural changes in some organs was made using the atherosclerosis model in guinea-pigs. A positive effect of cell therapy on these parameters was established. The effect was stronger and prolonged after transplantation of stem cells. Atherogenic diet weakens the effect of cell therapy. Thus, cell therapy is more effective in restriction of atherogenic risk factors.

Animals↗
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[Hemoperfusion via cryopreserved tissue fragments of xenogeneic spleen in suppurative-septic states in urology].

Hemoperfusion through cryopreserved fragments of porcine xenospleen tissue was used in combined treatment of 42 patients with pyoseptic urologic diseases: urosepsis, purulent intoxication due to acute pyelonephritis, pyoinflammatory scrotal and prostatic lesions (in 15, 19, 8 patients, respectively). Indications and contraindications are specified. Altogether 57 sessions were performed. Seventeen patients underwent the perfusion pre- and postoperatively, twenty-five in combination with chemotherapy. After the removal porcine spleen was dissected, treated with cryoprotective mixture (-196 degrees C) and placed into liquid nitrogen. One-year viability of the tissue retained in 82-93% of the samples. Duration of the hemoperfusion was 40-80 min, the rate--30-40 ml/min. Two-four columns with cryopreserved tissue were utilized which were alternately connected with the circuit. Heparinization reached 12,000-15,000 units. All the patients survived. Positive clinical and laboratory findings were obtained for 38 patients (90%). Urine and blood samples appeared sterile on day 7-12. The improvement of the severe condition of the patients is attributed to detoxication, immunostimulation and immunocorrective effects.

Acute Disease↗
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[Hypothermia as a damaging factor in heart preservation].

To study the mechanisms of hypothermic heart damage the authors analysed changes in the energetic condition and character of restoration of the contractile activity of the rat heart after heart ischemia and hypothermic storage of various duration. In contrast to damage in heat ischemia, the degree of cardiac function disorders after hypothermic storage did not correlate with the degree of the energy disturbances. Addition of 0.5% dimethylsulfoxide to the preservative solution reduced the degree of the functional disorders and increased the admissible duration of hypothermic storage. It is believed that disorders of the function of the heart in storage under low temperature are due to a great measure to the phase transfer of the membrane lipids and impaired intramembrane protein-lipid interrelationships.

Animals↗
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[An experimental study of the energy metabolism in the cortex of the single denervated kidney].

The long-term study of intratissular contents of ATP, ADP, AMP and the energy charge of the renal cortex in rats under the conditions of experimental combination of compensatory hypertrophy and chronic nervous decentralization enabled the authors to make the conclusion on the chronic energy-deficient status of the tubular cortical zones manifest by a two-wave decrease in the pool and the impaired spectrum of the adenyl system constituents. A negative trophic effect of demediatorization of chronically overloaded tissue of the cortex was found to be responsible for the disorders in the energy metabolism levels in the early phase of the disease and two months later for the progressive hypoperfusion of the cortical tubular system of a single denervated kidney.

Adenine Nucleotides↗
PubMedDate not supplied

[Effect of chronic denervation on blood flow and ultrastructural and functional status of the tubule system of the solitary kidney].

The sodium kidney treatment, local blood flow in the cortex and medulla as well as ultrametric parameters of mitochondria of different regions of the rat kidney duct system were studied under compensatory hypertrophy of kidneys (CHK) and against a background of aftereffects of single kidney decentralization (SKD). In all 120 experiments have been conducted. In the course of the first two weeks of the experiment the local blood flows in the cortex of SKD increased by 30% as compared to those under CHK and natriuresis+ was thrice as high (due to a decrease in proximal reabsorption). In this case coefficients of structural organization Km and of energy efficiency (Ke) of mitochondria lowered in cells of proximal ducts. Later on the intensity of local blood flows in the cortex of SKC was not only lower progressively than that under CHK but also of the control, simultaneously local blood flows in medulla being increased. The complete equalization of the sodium transport parameters of SKD up to their values under CHK did not occur. The rise of ultrametric parameters of the medullary ducts of SKD segments is associated with the intensification of their hemoperfusion.

Animals↗
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[Effect of vitamin E on the energy allowance of functional and plastic processes in the myocardium during ischemia and reoxygenation].

It was found that preliminary (before ischemia) administration of vitamin E in a dose of 200 mg/kg to albino rats causes the changes in energy support of the ischemic myocardium leading to prolonged maintenance of synthesis processes: energy production, cGMP concentration, unsaturation of cell membrane lipids increase. The combination of all these factors probably determines the anti-ischemic effect of vitamin E providing adequate restoration of the myocardial function in the postischemic period.

Animals↗
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[Action of vitamin E on the normal myocardial energy balance and in ischemia and reoxygenation].

The energy mechanisms of formation of anti-ischemic myocardial resistance have been studied by means of vitamin E, administered to rats 24 hours before modelling ischemia in a dose of 200 mg/kg, in which the antioxidant activity of the preparation is pronounced. At the stage of ischemia, myocardial energy was studied by the differential calorimetry method, in the pre- and postischemic periods on a functioning heart in a stand according to Neely. It is shown, that vitamin E in ischemic and postischemic periods enhances the power and efficiency of myocardial energy consumptions: decreases irrational energy consumptions in the initial period of ischemia (the first 15 minutes) and supports a higher level of energy production further on, increasing thus the admissible periods of myocardial ischemia from 20-25 to 30-35 minutes, maintains in the postischemic period a higher level of total useful energy consumptions and coefficients of the oxygen utilization efficiency as compared with the experiments without preliminary administration of vitamin E. It is shown, that the anti-ischemic defence of the myocardium by vitamin E is formed already in the preischemic period and conditioned by redistribution of energy consumptions and growth of the share of energy consumptions aimed at the maintenance of the initial structural-functional homeostasis of myocardial cells.

Animals↗
PubMedDate not supplied

[Stabilizing effect of the antioxidants alpha-tocopherol and sodium selenite following phospholipase damage to mitochondrial membranes in a model of anoxia].

The kinetics of the free fatty acids accumulation in membranes of isolated mitochondria of the brain, heart and liver of rats, with their incubation in a medium containing no substrates and ATP, was studied. The intensity of the phospholipase damage, measured by the rate of free fatty acids accumulation, augments in the sequence of: the liver-heart-brain. The amassment of fatty acids in the mitochondrial membranes is shown to give place to their penetration into the inner space of the mitochondria. A relationship between the content of the intramitochondrial calcium and the concentration of free fatty acids in in the membranes, on the one hand, and the degree of passive swelling of the cardiac mitochondria, on the other, was revealed. It is suggested that the free fatty acids or their derivatives act as carriers of calcium to the mitochondrial membrane. A preliminary administration to rats of the vitamin E and sodium selenite protects the mitochondria of the heart against the phospholipase damage. These agents display a synergic action and are effective with administration of physiological doses. It is presumed that the protective action of these substances is due to the stabilization of biological membranes.

Animals↗
PubMedDate not supplied

[Effect of alpha-tocopherol acetate and sodium selenite on the change in ATP content and the RNA synthesis rate in the ischemic myocardium].

The effect of preliminary administration of alpha-tocopherol acetate (1 mg/kg) and sodium selenite (1 mg/kg) on RNA synthesis rate and changes in the macroergic content in ischemic myocardium was studied. It was shown to be conducive to ATP level maintenance after 30- and 60-minute heart ischemia. A statistically significant accumulation of RNA by the myocardium following I-hour ischemia as well as this polynucleotide synthesis activation were recorded. Preservation of the energetic resources by the cell along with RNA metabolism returning to normal contributes to inhibiting the emergence of irreversible cell damage and increases regenerative potentialities of the myocardium.

Adenosine Triphosphate↗
PubMedDate not supplied

[Use of a differential calorimetry method for studying the energy mechanisms of the protective action of anti-ischemic agents].

Differential calorimetry is suggested for quantitative estimation of antiischemic activity of the drugs by determining total energy losses, the critical level of energy losses and permissible times of ischemia of isolated organs. The method allows the unraveling of the mechanisms by which antiischemic resistance of cells and organs is formed with pharmacological means.

Animals↗