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Biomedical subjects

L G Artemova

Publications and source records attributed to L G Artemova.

At least 19 recordsLinked to original sources

[Modifying effect of antioxidants on the rate of lipid peroxidation in liver microsomes at early stages of diethylnitrosamine biotransformation].

Lipid peroxidation and free radicals' generation were investigated in rats treated with carcinogenic diethylnitrosamine (DENA) after pretreatment with some antioxidants. It was shown that decreased generation of free radicals during DENA metabolism in rat liver microsomes after pretreatment of animals with antioxidants may be the cause of the protective action of these antioxidants against DENA toxicity. Lipid peroxidation was shown to be not a crucial reaction in the toxic effect of DENA.

Animals↗

[Changes in the structural characteristics and ATPase activity of the erythrocyte membranes in angiographically verified coronary artery lesion].

Structural characteristics and Na, K-ATPase activity of erythrocyte membranes were studied by the spin probe method in patients with an angiographically verified damage to the coronary arteries. The rise of the cholesterol/phospholipid ratio in patients with coronary heart disease was associated with the increased orderliness of the fatty acid chains of erythrocyte membrane lipids, leading to inhibition of Na, K-ATPase activity. The data point to the same line of changes in erythrocyte membranes and smooth muscle cells during the development of coronary heart disease.

Cholesterol↗

[Interaction of spin-labelled phosphatidyl choline with Ca-dependent ATPase from sarcoplasmic reticulum].

The interaction between 3-acyl-2-(6-doxylpalmitoyl) phosphatidyl choline used as a hydrophobic spin probe and Ca2+-dependent ATPase from sarcoplasmic reticulum membranes of rabbit and carp white skeletal muscles was studied. The spin label incorporation into ATPase preparations was performed at initial steps of ATPase isolation by incubating reticulum membranes with the spin probe in the presence of cholic acid. A comparison of the molecular mobility of the probe incorporated into ATPase preparations and into liposomes formed from ATPase phospholipids demonstrated that the presence of the protein in the membrane produces the same effect on the probe mobility as does the decrease of temperature by 10-15 degrees C. The molecular mobility of the probe in the ATPase preparation is increased during protein thermal denaturation. The breaks on the Arrhenius plots for the probe molecular mobility are revealed at the same temperatures (25 degrees for rabbit reticulum and 16 degrees for carp reticulum) as those for the ATPase activity.

Animals↗

[Structural and functional changes in erythrocyte membranes in experimental atherosclerosis].

Structural and functional characteristics of erythrocyte membranes were studied in rabbits with experimental atherosclerosis. In animals with single lipid spots in the aorta, a significant rise of the plasma cholesterol level was associated with the increased cholesterol/phospholipid (CS/PL) ratio and diminished activity of erythrocyte membrane Na+, K+-ATPase. EPMR spin probe data point to changes in structural membrane characteristics--an increase in order parameter for fatty acid chains of lipids and expansion of the temperature interval of the transition phase in the membranes. In rabbits with total aorta injury, a further increase both in the plasma cholesterol concentration and in the CS/PL ratio as well as in structural changes in erythrocyte membranes does not lead to another decrease in the enzymatic activity. In aorta homogenates of the experimental animals, the activity of Na+, K+-ATPase correlated with that in the erythrocyte membrane. This suggests the existence of similar chemical and structural changes in aorta cell membranes. The data may provide an indirect evidence in favour of the hypothesis of the involvement of smooth muscle cells and membrane enzymatic activity alterations in atherosclerosis.

Animals↗

[Effect of hyperalphalipoproteinemia on structural characteristics of plasma lipoproteins according to electron paramagnetic resonance spin probe findings].

Spin probe, a stearic acid derivative, was used to study the structural features of different lipoproteins (LP) from plasma of subjects with different plasma level of high density LP (HDLP). Access of spin probe located in the internal nonpolar regions of HDLP for the reducer, ascorbic acid, was higher in hyperalphalipoproteinemia than in mean values of HDLP cholesterol concentration. An analogous effect was seen in subjects with LP of very low density. Possible causes of such differences as well as their role in biochemical reactions that proceed with LP participation are discussed.

Adult↗

[Kidney resection in cancer].

The authors analyze 5 cases of conservative surgery in renal cancer and formulate their point of view on indications for such interventions in patients with contralateral kidney. Relevant techniques and policy are specified.

Adult↗

[Structural characteristics of plasma lipoproteins studied with spin-labelled fatty acids].

As shown by means of electrone paramagnetic resonance of spin probes, a magnitude of ordering of lipoprotein molecular arrangement both internal and external parts of molecule was decreased in a following sequence: high density lipoproteins greater than low density greater than very low density lipoproteins. Permeability towards a reducing agent - ascorbic acid - was altered similarly in the lipoprotein surface monolayer.

Adult↗

[Computer simulation of ESR signals of liver paramagnetic centers].

Changes of paramagnetic centres concentration characterized by g-factors values of 1.94, 2.2, and 2.03 in the rat liver were studied by ESR method under acute intoxication by diethylnitrosamine (DENA) and at preliminary threefold treatment of animals with butylhydroxytoluene (BHT). A protective effect of BHT can be explained by its stabilizing action of the membrane structures. A comparison has been carried out with a similar study of paramagnetic centres in the experiment of chronic intoxication by DENA. A simulation was performed of the liver tissue ESR spectra by means of special computer program. The parameters of simulated ESR spectra of the liver tissue with due regard for ESR signal g 2.03 corresponded to the parameters of the experimental spectra. Confirmations were obtained for the nature and number of paramagnetic centres in the liver tissue.

Animals↗

[Electron paramagnetic resonance spectra with g=2.03 of the animal liver tissue treated with butylhydroxytoluene and diethylnitrosamine].

ESR spectra g=2.03 intensities of rat liver tissues were studied under the action of cancer agent either diethylnitrosamine (DEN) with butylhydroxytoluene (BHT) injected before DEN or without BHT at 77 K. Combined influence of DEN and BHT upon the intensity change of ESR spectra with g=2.03 at animal disease is explained by modified action of DEN metabolism.

Animals↗