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Biomedical subjects

I Zak

Publications and source records attributed to I Zak.

16 recordsLinked to original sources
PubMed2000

Selectin glycoprotein ligands.

Lectin selectins and their counter-receptors participate in discontinuous cell-cell interactions concurrent with leukocyte tethering and rolling on endothelium, which, in consequence, leads to leukocyte penetration to lymphatic organs and generation of inflammation sites. Counter-receptors are glycoproteins in which carbohydrate units, the direct selectin ligands, are built into the polypeptide framework. In this review, the distribution, structure and function of the main ligands and counter-receptors for P-, L- and E-selectins known so far, have been discussed. The common biosynthetic pathway of sialyl-Lewis x and sulpho-sialyl-Lewis x determinants of selectin ligands has been described.

Animals↗
PubMed1995

[Mosaic proteins].

Explore the source record for details and available documents.

Cell Adhesion↗
PubMed1991

Composition of proteoglycans from rabbit aorta in the experimentally induced atherosclerosis.

Proteoglycans (PG) from normal and atherosclerotic rabbits aortas were extracted with 4 M guanidine hydrochloride and digested with collagenase in the presence of protease inhibitors. The contents of uronic acid and hexosamine from PG fractions purified by isopycnic CsCl gradient ultracentrifugation under associative and dissociative conditions were significantly higher in the atherosclerotic aortas (up to 40%) than in the control tissue. The uronic acid/protein ratio increased from 0.7 to 1.3 in the monomers PG fraction of atherosclerotic aortas. Chromatographic separation and electrophoretic analysis of PG monomers indicated the presence of three different subfractions PGI, PGII and PGIII in both groups of animals. The uronic acid/protein ratio in PGI from experimental aorta was increased whereas this ratio in PGIII was decreased compared to contrast tissue. The observed increase of sugar component in the core proteins suggests their over glycosylation.

Animals↗
PubMed1986

In vitro effects of ethanolamine on insulin secretion.

The effects of ethanolamine on insulin secretion by the perfused rat pancreas were examined. During the second phase of glucose-induced insulin secretion 5-minute perfusions of ethanolamine at final concentrations of 0.1, 1 and 10 mM inhibited insulin release in a dose-related manner. When given throughout the experiment the highest dose of ethanolamine markedly suppressed both phases of glucose-induced insulin release. The inhibitory effect of ethanolamine was blunted in the presence of phentolamine. It is concluded that ethanolamine inhibits glucose-induced insulin secretion by the perfused rat pancreas and that alpha-adrenergic receptors play a role in its actions on insulin output.

Animals↗
PubMed1982

Incorporation of 7-ketocholesterol by plasma membranes from porcine aortic endothelial cells.

We present evidence that 7-ketocholesterol (7KC) is incorporated into the plasma membranes of endothelial cells in excised porcine aortas in molar amounts comparable to the native cholesterol present in the membrane. Our experimental findings indicate that simple adsorption of 7KC does not play a role in the results obtained. Instead 7KC appears to be inserted into the lipid bilayer of the membranes. This is largely independent of membrane cholesterol content and is not due to substitution of the native membrane cholesterol. A significant increase in the total sterol-to-phospholipid ratio is obtained with 7KC-exposure without significant changes in the cholesterol-to-phospholipid ratio.

Alkaline Phosphatase↗
PubMed1980

[Pulmonary ventilation and lead absorption in workers of non-ferrous metallurgical plants].

The biological response to lead, taking into account pulmonary ventilation values, has been checked in nonferrous metal plant workers. Except for lead rolling-mill workers, increased blood lead, decreased delta-aminolevulinic dehydratase activity in erythrocytes, and increased urinary excretion of lead, delta-aminolevulinic acid and coproporphyrin were found in the metallurgists. The intensity of the biological response to lead was dependent on pulmonary ventilation. A positive, statistically significant correlation was found between these indices. With extensive correlation studies, a lead dose was calculated that is probably absorbed in the respiratory tract during a6-hr shift. This dose ranges between 352 -- 1056 mu g in lead refiners exposed to identical airborne lead concentration (0.163 mg/Pb/m3), the degree of physical effort being different (pulmonary ventilation from 11.8 -- 35.8 1/min). The authors indicate a need for including -- to a greater extent than so far -- pulmonary ventilation measurements in lead exposure evaluation.

Absorption↗
PubMed1979

The common space of personality traits and vocational interests.

Investigated relationships between personality traits and vocational interests. Cattell's (Research and Consultations Center of Educational Personnel, 1976) CAQ Part I and the Ramak interest inventory (Meir, 1975) based upon Roe's (1956) occupational classification system were administered to a sample of 397 university applicants. Canonical Correlation Analysis and Smallest Space Analysis were used to test two hypotheses (a) relationships exist between personality traits and vocational interests; and (b) personality traits which characterize occupational profiles are arranged in circular order corresponding to the configuration Of the vocational fields which represent those occupations. Both hypotheses were supported by the data.

Journal Article↗
PubMed1978

[Effect of cadmium on serum level of total protein and glycoprotein carbohydrate components in rats].

In experimental cadmium intoxication 100 rats were intraperitoneally injected with single doses of 0; 5 1,0, 2,0 5,0 mg Cd++/kg body weight as well as with 14 doses of 0,25 mg Cd++/kg. In the serum of animals the level of total protein and of glycoprotein carbohydrate components was determined. After doses in the range of cadmium concentration from 0,5 to 2,0 mg Cd++/kg body weight, a statistically and significant increase of the serum level of the protein-bound hexose hexoamine and sialic acids was stated. On the other hand the dose of 5,0 mg Cd++/kg caused only the increase of hexose in comparison with values of these constituents recorded in the control group. In animals receiving multiple doses of cadmium and also in those after a single administration of 1,0 mg Cd++/kg, a significant increase of the total protein level was started. The last group revealed the highest concentrations of protein and glycoprotein carbohydrate constituents on the third day after injection of cadmium while after 14 days, amouunts of these compounds approximated the levels estimated in the control group. A univocal evaluation of the obtained results is difficult, however in the mechanism of the quantitative alterations within the glycoprotein components of rats serum, the possibility of cadmium--induced biosynthesis of these compounds should be taken into consideration.

Animals↗