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Biomedical subjects

A P Shepelev

Publications and source records attributed to A P Shepelev.

36 records · Page 2Linked to original sources
PubMedDate not supplied

[A modification of lactoferrin isolation method].

A modified method was developed to isolate lactoferrin from women's colostrum by means of ion-exchange chromatography on a Servacel CM-52 column and gel filtration on a Toyoperal HW-52 column. These changes simplified the basic method and decreased the length of the procedure without affecting the biological activity and purity of the preparation. The modified method can be recommended to produce lactoferrin suitable for the use as a pharmaceutical preparation and nutritional additive to milk substitutes.

Chromatography, Ion Exchange↗
PubMedDate not supplied

[Modern concepts of adipocere formation mechanisms].

Biochemical parameters of transformation of fresh subcutaneous fat into adipocere have been studied in experiment. Activation of lipid peroxidation is a significant component of the mechanism of adipocere transformation, which is proven by a drastic increase in the level of Schiff's bases in adipocere in comparison with subcutaneous fat. The concentrations of myristic, palmitic, and stearic fatty acids increase during the formation of adipocere, while the content of linoleic acid decreases in comparison with the unchanged human subcutaneous fat.

Adipose Tissue↗
PubMedDate not supplied

[Erythrocyte membranes and antioxidant provision in experimental acute pancreatitis].

Experiments were conducted on rats with induced edematous and hemorrhagic forms of acute pancreatitis (AP) to study the parameters characterizing the state of the red cell membranes: hemolytic efficiency, glucose-6-phosphate dehydrogenase activity, extra-erythrocytic hemoglobin concentrations. The values characterizing the bio-antioxidative defense were also studied: superoxide dismutase activity and antioxidative property. The development of experimental AP is attended by injury to the red cell membranes among the causes of which is poor antioxidative provision.

Acute Disease↗
PubMedDate not supplied

[Effect of non-enzymatic desamidation of gamma-globulin on its properties and biological activity].

During incubation of gamma-globulin preparations under conditions similar to physiological ones within 28 days (0.9% NaCl, pH 7.0, 37 degrees) as well as during storage at 3-10 degrees within 36 months gradual nonenzymatic deamidation of the protein occurred mainly due to hydrolysis of readily accessible amide groups (asparagine). Fluorescence of the preparations decreased gradually in the course of deamidation; it constituted for 82% of the initial value after incubation during 28 days. Immunological activity of the gamma-globulin, which lost 19.6% of amide groups, was decreased by 34%; alteration in the amidation by 45.1% was accompanied by a decrease in active antibodies concentration by 92.3%. Nonenzymatic deamidation may be responsible for conformational alterations and inactivation of gamma-globulin.

Amides↗
PubMedDate not supplied

[The effect of Staphylococcus aureus toxic shock exotoxin on whole blood cell chemiluminescence in vitro and in vivo].

Stimulated and nonstimulated blood chemiluminescence were studied in presence of the toxic shock syndrome toxin I (TSST-I) in vivo and in vitro. In vivo experiments involved evaluation of rabbit whole blood chemiluminescence developed within various periods after the TSST-I intraperitoneal administration. Effect of various TSST-I concentrations on blood chemiluminescence was studied in vitro. TSST-I was shown to inhibit the nonstimulated chemiluminescence in blood within 45 min after administration of LD50 of both opsonized zymosan and calcium ionophore A 23187 in vivo. Similar effects the toxin exhibited at concentrations 20 microM and more in vitro. The maximum effect TSST-I demonstrated within the first 5 min of incubation and this effect was distinctly dose-dependent.

Animals↗
PubMedDate not supplied

[Effect of acute overheating of animals on the processes of lipid peroxidation].

In liver tissue, brain, lungs and skeletal muscles of rats, subjected to overheating, content of conjugated diens and lipid peroxides was distinctly increased. The decrease in the period of malon dialdehyde induction and in the antioxidative activity of lipids correlated with the alteration in content of peroxidation products. The overheating of animals was accompanied by a decrease in unsaturation of lipids in liver tissue, brain and skeletal muscles due to a decrease in amounts of arachidonic acid and to an increase in content of palmitinic and stearinic acids. In lipids of lungs the unsaturation was increased as a result of increase in content of linoleic acid. Administration of alpha-tocopherol and ionol, 10 min before the overheating and in hypothermia, exhibited a protective effect, thioTEPA caused an opposite action. Administration of alpha-tocopherol and ionol 24 hrs before the thermic treatment decreased the survival period of the animals which were subjected to the overheating.

Alkadienes↗
PubMedDate not supplied

[Induction of Ca2+-dependent chemiluminescent response of peritoneal macrophages with bacterial lipopolysaccharides].

A lipopolysaccharide preparation obtained from Klebsiella pneumonia was shown to affect primarily the peritoneal macrophages after intraperitoneal administration. Transition of the macrophages to a new metabolic state in response to opsonized zymosan was responsible for a distinct increase in the rate of luminol-dependent chemoluminescence. At the same time, the macrophages produced chemiluminescence was only slightly increased in the presence of Ca2+ ionophore A23187. These dissimilar alterations observed suggest that the primary reaction of macrophages in response to the lipopolysaccharide occurred with the increase in content of intracellular free calcium. Administration of finoptin (calcium influx inhibitor) into suspension of macrophages caused a decrease in the rate of chemiluminescence response.

Animals↗
PubMedDate not supplied

[Relationship between the depth of acute hypothermia and the composition and phase transitions of mitochondrial lipids of dog and white rat myocardium].

It has been found in the experiments on white rats and dogs that the increase of body temperature by 8--10 degrees in myocardium mitochondria composition of phospholipids is changed, microviscosity of lipids decreases, the phase transition is shifted to the low temperature region. Changes in white rats' mitochondria are expressed to a greater extent. When the body temperature is decreased by 18--20 degrees microviscosity of lipids in dog myocardium mitochondria increases, that of white rats is maintained on the same level. Effect of the composition of membrane lipids on the temerature of phase transitions during hypothermia is discussed, as well as possible dependence of the stability of animals towards low temperatures on the degree of reconstruction of the membrane lipids.

Animals↗