PubMed Health⌕ Search

Biomedical subjects

E E Mkheian

Publications and source records attributed to E E Mkheian.

At least 19 recordsLinked to original sources
PubMed1981

[Changes in the structuro-functional properties of erythrocytes in vascular diseases of the brain].

In patients with various impairments of brain circulation a decrease in deformation and osmotic stability of erythrocytes were observed. These findings correlated with the decrease in activity of Na+, K+- and Ca2+-ATPases from the cell membranes. At the same time, the Mg/+-ATPase activity was markedly increased. Conductivity for K+, Na+ and Ca2+ was increased in lipid bilayer of erythrocytes obtained from the patients with brain vascular pathology.

Calcium-Transporting ATPases↗
PubMed1981

[Microcirculatory disorders in patients with cerebrovascular pathology].

The microvascular network of the labial mucosa and the nail bed, as well as the rheological properties of the blood were examined in 132 patients with various forms of cerebral circulation disorders. It was shown that the patients with the cerebrovascular pathology had organic changes of the capillaries. At the same time a hyperreactivity of the microvessels was observed. This hyperreactivity was more marked in patients with initial forms of the cerebrovascular disturbances. In the patients examined an increased permeability of te capillaries for protein and water was revealed: this increase was found to correlate with the disease gravity. Along with the vascular changes the patients also showed disturbances of the blood rheological properties. These disturbances manifested in an increased viscosity of the blood (especially at low shear speeds) and an increased aggregation of erythrocytes. It was also found that not only the erythrocyte aggregation, but also the strength of the aggregates formed were increased: this correlated well with the disease gravity.

Capillary Permeability↗
PubMed1980

[Erythrocyte deformability in patients with acute cerebral circulatory disorders].

The capacity of erythrocytes to deformation was examined in patients with acute disturbances of the cerebral circulation. It was shown that in patients with transient cerebral circulation disturbances and brain infarctions this capacity of erythrocytes was sharply lowered. It was accompanied by a greater capacity of erythrocytes to aggregation and by a lability of weakly linked proteins of the erythrocytic membranes. It was also shown that in patients with brain infarction the lipid fraction of the erythrocytic membranes was more viscous.

Acute Disease↗
PubMed1978

[Effect of gangliosides on Na-K-ATPase activity and the conformation of microsomal membranes].

The effect of gangliosides on the activity of Na, K-ATPase and K-dependent nitrophenyl-phosphatase was studied. Low concentrations of gangliosides proved to activate Na, K-ATPase, and high ones to inhibit it. All the concentrations of gangliosides produced only an inhibitory effect on the K-dependent nitrophenyl-phosphatase. Inhibition of the enzyme by gangliosides is reversible and competitive in respect to K+. Calculation of Hill's coefficient demonstrated that both in case of the activating and of the inhibitory action gangliosides acted allosteric effectors. To ascertain the action mechanism of gangliosides on the enzyme their effect on the microsomal membranes was studied by the fluorescent probe method. Gangliosides were found to produce marked conformation shifts in the membranes of the brain microsomes.

Animals↗
PubMed1978

[Blood glycolipids of patients with cerebral circulatory disorders].

The paper is concerned with a study of the glycolipid content in the blood of 70 patients with acute disorders of brain circulation and in 14 patients with the initial signs of insufficiency of circulation. It was established that in the plasma and blood cells in patients with ischemic and hemorrhagic strokes the amount of gangliosides and cerebrosides were considerably higher than in normals (35 cases). In patients with transient disorders of brain circulation and initial signs of insufficiency of brain circulation the content of glycolipids is increased to a lesser degree. A conclusion has been made that there is a possible involvement of oligosaccharidceramides (mono- and asyalgangliosides, galactocerebrosides) in the occurrence of disorders in cerebral hemodynamics.

Acute Disease↗
PubMed1978

[Role of the superior cervical sympathetic ganglion on regulating the amount of brain cell nuclear histones].

The quantitative changes of histones and their fractions and of nonhistone proteins in nuclei of cerebral cells have been studied in normal animals and following removal of the right superior cervical ganglion. On the next day after sympathectomy the total amount of histones was shown to increase by 17% in nuclei of cells of the right hemisphere while in nuclei of cells of the left hemisphere an increase of 38% was observed 3 days after sympathectomy. Histone fractions rich in lysine were also found to increase. The amount of nonhistone proteins begins to decrease on the next day after sympathectomy and reaches 33% of control values by the third day.

Animals↗
PubMed1976

[Changes in the ribonuclease activity of brain cell nuclei and mitochondria at different periods following removal of the superior cervical sympathetic ganglion].

A study of the changes in the ribonuclease activity of nuclei and mitochondria of rat brain cells following 1, 3, 7, 20 and 90 days after extirpation of the right superior cervical ganglion showed an increase of enzyme activity in nuclei from the first up to the 90-th day following removal of the ganglion. During the first three days after the operation enzyme activity is higher in nuclei obtained from the intact (left) side of the brain while later on enzyme activity is more pronounced in nuclei obtained from the right (sympathectomized) side of the brain. In mitochondria enzyme activity is depressed during the whole period studied after sympathectomy (90 days).

Animals↗
PubMed1975

[Character of loosely and tightly bound human cerebral gangliosides and methods of preparatory extraction].

The quantitative isolation of loosely and tightly bound gangliosides of human brain has been studied following various ways of extraction. Hot methanol extraction (Bogoch's method) gave a higher level of tightly bound gangliosides than by extraction with the Folch method. Both kinds of gangliosides were found to have the same fractional composition on thin layer chromatography on silicagel. A single extraction method of gangliosides giving high yields is proposed.

Brain Chemistry↗
PubMed1974

[Quantitative changes in the nucleic acid nuclear fraction of rat brain cells following removal of the superior cervical sympathetic ganglion].

The nucleic acid content of the nuclear fraction of cerebral hemispheres was studied 1, 3, 7, 20 and 90 days after unilateral removal of superior cervical ganglion. The results obtained indicate that the content of nuclear RNA is significantly reduced in the desympathized side 1 day after removal of the ganglion. Seven days after sympathectomy the content of RNA increases, reaching control levels. Beginning from the 20th day it decreases and remains at a low level for 90 days. This decrease is observed on both sides of the brain. The content of nuclear DNA is significantly reduced seven days following removal of superior cervical ganglion. The possible mechanisms of the alterations observed are discussed in connection with changes in correlation of nucleic acids with nuclear proteins.

Animals↗
PubMed1974

[Changes in the terminal oxidation and active transport of calcium ions in the cerebral mitochondria of white rats following chronic cerebroside administration].

Terminal oxidation and active Ca ion transport have been studied in rat brain mitochondria following intraperitonial administrations of cerebrosides for 30 days. The results obtained have shown that cerebrosides inhibit terminal respiration at its 3rd metabolic state and reduce the rate of phosphorylation. ADP/O and ATP/t coefficients decrease due to the active transport of Ca ions. On increasing ADP and CaCl2 the time necessary for the binding and release of hydrogen ions is prolonged.

Animals↗