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Biomedical subjects

M V Baranchikova

Publications and source records attributed to M V Baranchikova.

14 recordsLinked to original sources
PubMed1998

[Hemodynamic effect of plasma DNA].

To reveal the hemodynamic effect of plasma DNA, the authors measured the concentrations of plasma DNA, the length of its molecular fragments, and hemodynamic resistance/Toms effect. The Toms effect was detected in all blood samples from 10 healthy donors and 39 patients without acute stroke caused by atherosclerosis of the head great arteries with and without arterial hypertension. There was a clear inverse relationships between the plasma concentrations of DNA which had only long-molecular fragments in healthy persons and the hemodynamic resistance of its blood flow samples. The patient blood plasma had significant increased DNA concentrations but their molecular fragments were long and short. Inverse relationships between the plasma DNA concentration and the hemodynamic resistance of the patients' blood flow samples had a less correlation coefficient due to the high proportion of short DNA molecular fragments. The Toms effect was shown in the DNA solution prepared only from human funic blood where the DNA molecular fragments were long. The Toms effect was absent in the solutions prepared from the commercial cattle or salmon sperm DNA which contained shorter DNA molecular fragments. It is concluded that plasma DNA has a hemodynamic effect and the origin of long-molecular fragments of DNA which is typical for healthy young persons and short DNA molecular fragments that additionally appear in patients with vascular disorders is different.

Acute Disease↗
PubMed1993

[Diminished experimental alimentary atherogenesis under the influence of polymers that decrease the hydrodynamic resistance of the blood].

The experiments on adult rabbits have demonstrated that high-cholesterol diet given to the animals for 3 months causes a severe hypercholesterolemia and disseminated aortic lesion due to the formation of numerous fatty streaks and plaques of atherosclerotic genesis. The simultaneous intravenous injection of a special linear high molecular-weight polymer solution, which reduces hydrodynamic resistance once a week leads to a significantly less atherogenesis in the same hypercholesterolemia. The highest effect was observed in the descending portions of the aorta and just after its bifurcation, i.e. in the areas of the least unsteady blood flow.

Animals↗
PubMed1989

[Changes in energy metabolism in the brain in experimental cerebral ischemia of different degree of severity (nuclear magnetic resonance-spectroscopic study)].

The peculiarities of brain energy metabolism were studied in male rats before and during cerebral ischemia of various severity elicited by bilateral common carotid arteries ligation. A multidimensional analysis was applied. In the rats which died after the ischemia, the NAD + NADH+/phosphocreatine (PCr) ratio and ATP content before ligation were higher than those in the surviving group. Also the strength of relationships between parameters of NMR spectra in each correlation matrix were 10 times higher and the variability of elements in each matrix was significantly lower in victims than those in the surviving group. The development of severe ischemia and the animals death were accompanied by an increase in the inorganic phosphate content, decrease in pH and stepwise disappearing of PCr and ATP. In animals surviving the same brain ischemia model, the changes in 31P spectra parameters pointed to some increase in the ratio of NAD + NADH+ only to ATP + ADP but not to PCr, and to an increase in summarized strength of correlation between 31P spectra parameters with the variability of elements decreased within each correlation matrix. Detection of these changes can be helpful in the diagnosis of mild ischemia without neurological deficit which already needs preventive therapy against more severe ischemia.

Animals↗
PubMed1989

[Prognostically significant indices of the bioenergetic metabolism of the brain in experimental ischemia (a NMR spectroscopic study)].

Initial levels of phosphate brain metabolites were measured using 31P NMR spectroscopy in rats which subsequently died or survived under bilateral ligation of common carotid arteries. A multidimensional analysis was applied. In the rats which died after the brain ischemia: (1), NAD and NADH+ concentrations were much higher than those of creatine phosphate or ATP (i.e. baseline dysbalance existed between the systems of hydrogen acceptors and major macroergic substances); (2), the force of relationships between parameters of NMR spectra in each correlation matrix were 10 times higher and the variability of elements in each matrix was significantly lower than those of the surviving group. These regularities can be used in detection of special groups at high professional risk and in designing individual procedures of prevention and treatment of cerebral circulation disorders. The data are valuable in terms of development of drugs which would correct the dysbalance between hydrogen acceptors and macroergic systems thus providing a metabolic defense for the ischemic brain.

Animals↗
PubMed1987

[Status of the "dead point" of blood flow in anastomoses of superficial cerebral arteries as affected by an acute increase of blood pressure].

Changes in pial arteries diameter and the condition of blood flow "dead point" in arterial anastomoses were established using the brain window during an acute increase of mean arterial pressure (MAP) induced by intravenous injection of norepinephrine (NE) with microcineangiography and the analysis of films and frames on a montage table and TAS ("Leitz"). During an acute increase of MAP the movement of blood flow "dead point" in anastomoses and the expansion of plasma segments occurred much more frequently than in normotension. The stabilization of blood flow "dead point" was observed at high constant MAP. Pronounced dilation of both pial arteries and veins first occurred in anastomoses, then spread to arterial branches. It is assumed that high vulnerability of the brain vessels of the borderline zones is due to breakthrough in autoregulation of cerebral blood flow on its upper limit and depends on the repeatedly changing directions of the blood flow and its moving "dead point", as the peripheral resistance of arterial anastomoses-forming branches under these circumstances changes in an irregular manner.

Animals↗
PubMedDate not supplied

[Effect of different doses of dexamethasone on the course of brain injuries in animals sensitized to nerve tissue antigens].

The effect of different dexamethasone doses on the development of edema of the brain in its injury was studied on 79 rabbits, controls and those sensitized with the brain antigen. The local cerebral circulation and the total tissue fluid in the perifocal region of the injured grey and white matter of the rabbit's cerebral hemispheres were studied; EEG was recorded and ultrastructural study of the nervous tissue in the zone of the trauma at the level of the ultrastructures was conducted. The examination showed that dexamethasone had a favourable therapeutic effect on the course of the brain trauma in the early periods after it was inflicted; the agent reduced edema of the brain tissue, which was especially manifest in animals with altered immunological reactivity of the organism. The best effect in these animals was caused by large doses of dexamethasone.

Animals↗
PubMedDate not supplied

[Comparative characterization of morphologic changes in animal brain after normo-, hypobaric hypoxic hypoxia and hypobaric normoxia].

In three series of experiments on 16 randomly inbred adult male rats, specific features of morphological changes in the brain were studied 3 days following the tests of animals for high- or low-resistance to hypoxic hypoxia (HH) during hypobaric HH (Series I), normobaric HH (Series II), and hypobaric normoxia (Series III). The conventional testing was found to result in changes in the rat brain, which were caused both by HH and decompression. The more sparing procedure is testing animal during normobaric HH which eliminates the impact of decompression whose damaging action was pronounced in hypobaric normoxia. Thus, the sensitivity of rats to HH should be detected, by using the least brain-traumatizing modified procedure--normobaric HH.

Altitude↗
PubMedDate not supplied

[Effect of the nootropic agent cerebrolysin in cerebral ischemia in rats with varying behavioral reactions in the open field test].

Open field tests were made on 489 white male rats to distinguish subgroups by baseline higher nervous activity (HNA) to study the effects of cerebrolysin (EBEVE, Austria) on relationships between neuronal activity and cerebral blood supply in normal cerebral circulation (CC) and in acute brain ischemia. Local CC and EEG were measured by laser doppler flowmeter and read from the same point gauge. CC/EEG index was calculated. Cerebrolysin was injected i.p. in a dose 0.3 ml/100 g body mass. Brain ischemia was provoked by occlusion of the common carotid arteries. Neurological symptoms were estimated according to the McGrow scale. Also, 24-h lethality was registered. It was confirmed that cerebrolysin, as an active nootrop, enhances EEG. This effect takes place both in intact and brain ischemia rats. It was also found that cerebrolysin has different effectiveness dependent on the animal's behavior in the open field test, that blood supply to the brain does not increase in cerebrolysin-activated HNA. In stable circulation, this was compensated due to cerebral metabolic reserve, but in intensive EEG activation, recorded by CC/EEG index, cerebrolysin reduces cerebral blood supply aggravating acute brain ischemia.

Amino Acids↗