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S N Cherenkevich

Publications and source records attributed to S N Cherenkevich.

At least 19 recordsLinked to original sources
PubMed2006

[Formation of reactive oxygen species in monocytes at adhesion to glass].

Processes of oxygen activation in monocytes stimulated with adhesion to glass were studied by methods of luminol-dependent and lucigen-independent chemiluminescence. It was shown that monocyte chemiluminescence was caused by cell adhesion to glass surface. Generation of reactive oxygen species at monocyte adhesion to glass was dependent on calcium ion concentration in the medium. The increase in the level of cytosolic calcium, as the extracellular calcium concentration elevated, was accompanied by the activation of phospholipase A2, 5-lypoxygenase and cycloxygenases. Magnesium ions exerted no influence on oxygen activation by cells. Incubation of cells in glucose-free medium, or the addition of glycolysis blocker (2-deoxy-D-glucose) to cell suspension led to a decrease in chemiluminescence intensity. By means of inhibitory analysis, it has been established that processes of oxygen activation are related to arachidonic acid metabolism, and depend on the activity of phospholipase A2.

Arachidonate 5-Lipoxygenase↗
PubMed2006

[Regulation of morphologicaland functional properties of astroglial cells by hydrogen peroxide].

Effects of hydrogen peroxide on morphological characteristics, proliferation index, menadione-dependent lucigenin-enhanced chemiluminescence of C6 glioma cells were studied. It was established that H2O2 at 1 x 10(-8) - 5 x 10(-7) M concentrations acts as a regulator of morphological and functional properties of astrocytes by inducing their reactivation that is manifested as a cell body hypertrophy and an increase of proliferative activity and of menadione-dependent production of superoxide (O2- ). Cytodestructive action of hydrogen peroxide at a concentration higher than 1 microM on C6 glioma cells shows itself as a decrease of their proliferation index and the ability to generate O2- under menadione action. Using lipopolysaccharide B as a functional stimulator it has been shown that H2O2 modifies signaling pathways leading to the increase of mitotic activity of C6 glioma cells and decreases the yield of lucigenin-enhanced chemiluminescence of astrocytes under menadione action to the level of control values.

Animals↗
PubMed1999

Differential potency of two crosslinking plant lectins to induce formation of haptenic-sugar-resistant aggregates of rat thymocytes by post-binding signaling.

To evaluate the significance of post-binding events for stable aggregate formation, the aggregation/dissociation of rat thymocytes initiated by two crosslinking plant lectins, namely concanavalin A (Con A) and Solanum tuberosum agglutinin (STA), were comparatively studied. Despite intimate cell contacts in the aggregates only Con A led to establishment of haptenic-sugar-resistant (HSR) complexes. The presence of inhibitor II of diacylglycerol kinase, a dual calmodulin antagonist/protein kinase C inhibitor (trifluoperazine), and a sulfhydryl group reagent (N-ethylmaleimide) impaired this process. The obtained results indicate that the formation of HSR cellular contacts is not an automatic response to lectin-dependent cell association. In contrast to STA, Con A binding elicits this reaction with involvement of diacylglycerol kinase, protein kinase C and/or calmodulin as well as thiol level perturbation, as inferred by the application of target-selective inhibitors.

Animals↗
PubMed1998

[Lectin-reactive immune complexes in plasma in ENT diseases].

The content of circulating immune complexes (IC) interacting with plant lectins from Canavalia ensiformis (Con A), phaseolus vulgaris (PHA) and wheat germ (WGA) was examined in blood plasma of healthy donors and patients with ENT diseases (n = 36). It was found that the level of PHA- and WGA-reactive IC in patients with laryngeal carcinoma was significantly higher than in control, whereas only the level of WGA-reactive IC was elevated in patients with scleroma. The level of ConA-reactive IC was statistically uniform in control and both ENT diseases.

Antigen-Antibody Complex↗
PubMed1997

Metabolic inhibitors as tools to delineate participation of distinct intracellular pathways in enhancement of lactose-induced dissociation of neutrophil and thymocyte aggregates formed by mediation of a plant lectin.

Signaling processes in the course of the formation of the lectin-mediated aggregates may partake in conveying enhanced stability to the cell clusters. To prove the validity of this reasoning in a model, we have studied the impact of addition of three metabolic inhibitors (N-ethylmaleimide, nordihydroguaiaretic acid, and trifluoperazine) on lactose-dependent dissociation of cell aggregates, formed in the presence of the galactoside-binding mistletoe lectin. Using both human neutrophils and rat thymocytes to avoid measurement of responses restricted to a single cell type, an enhanced dissociation of lectin-formed cell aggregates was observed, when lactose and an inhibitor were present. Among the tested inhibitors, nordihydroguaiaretic acid and N-ethylmaleimide were more potent enhancers of cell dissociation than trifluoperazine. These results suggest that biosignalling pathways connected with lipoxygenase activity as well as the level of intracellular sulfhydryl groups confer further stability to lectin-dependent cell aggregates. The systematic evaluation of inhibitors for defined activities is thus suggested as a tool to disclose the nature and the contribution of individual signaling mechanisms to post-binding effects following lectin-initiated cell contact formation.

Animals↗
PubMed1996

Effects of metabolic inhibitors and lectins on the menadione-dependent generation of H2O2 by rat thymocytes.

The capacity of oxidative metabolism and its regulation is an important factor in disease control. Using scopoletin as a fluorescent substrate of peroxidase the extent of menadione-dependent production of H2O2 by rat thymocytes was determined. The reaction was inhibited by 2,4-dinitrophenol, papaverine, nordihydroguaiaretic acid and iodacetamide. The membrane-penetrating SH reagent N-ethylmaleimide primed the reaction, probably due to an inhibition of glutathione peroxidase. To delineate an influence of cell-surface protein-carbohydrate interactions by exogenous lectins, the impact of cell binding was analyzed for several plant lectins, namely concanavalin A, phytohemagglutinin, the lectins from Triticum vulgaris and from Sambucus nigra. Except for the alpha-NeuNAc(2-6)gal/galNAc-binding agglutinin, the other three plant proteins with specificities to different parts of N-linked oligosaccharides primed the reaction. This activity of lectins did not coincide with their ability to aggregate cells. The given results indicate that biosignaling pathways triggered by lectins are involved in the regulation of the intracellular reduction of menadione.

2,4-Dinitrophenol↗
PubMed1995

Viscum album agglutinin-induced aggregation of blood cells and the lectin effects on neutrophil function.

Extracts from mistletoe enjoy a large popularity in central Europe as an unconventional treatment modality for cancer, warranting scientific efforts with defined components to delineate any potential benefit. The galactose-specific lectin from Viscum album (VAA), known to exhibit immunomodulatory and ensuing antitumoral capacities in animal model systems, was shown to aggregate human blood cells in the following order: neutrophils, mononuclear cells--thrombocytes and erythrocytes. To contribute to the analysis of lectin effects on individual aspects of the host defence system, two parameters of neutrophils were quantitatively assessed, namely the aggregating activity of VAA as a measure of strength of interaction with cell surface ligands and the effect of lectin on oxidative metabolism (H2O2 release) of these cells. It was found that whole lectin and its carbohydrate-binding B-subunit possessed the capacity to induce cell aggregation and H2O2 release, which were blocked by D-galactose and lactose. Both effects displayed similar dependence on the lectin concentration in the range 0.1-25 micrograms/ml. The toxic A-subunit displayed detectable activity only in high doses (50 micrograms/ml) while the bovine heart galaptin (14 kDa; galectin-1) failed to affect neutrophils. The role of oxidative metabolism in regulation of neutrophil aggregation induced by VAA was studied using metabolic inhibitors and controlled heating at 46 degrees C leading to inhibition of plasma membrane NADPH-oxidase system. Trifluoperazine and menadione inhibited the neutrophil aggregation in a dose-dependent manner in comparison with such inhibitors as amiloride and theophylline.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Cells↗
PubMed1993

[A comparative study of the reactions of the peripheral blood neutrophils from donors and from lymphogranulomatosis patients to arachidonate stimulation of the cells].

Arachidonate-induced aggregation and generalization of active oxygen forms (OAF) by peripheral blood neutrophils in donors were studied in donors and Hodgkin's disease patients. Leukocytes of the latter had incomplete ability to produce AOF in response to cell stimulation with arachidonic acid. The study of arachidonate-induced aggregation of neutrophils indicated no differences in the speed of the process in the patients and donors. AOF catchers did not act on the rate of leukocyte aggregation in the patients though accelerated the process in the donors. It is inferred that Hodgkin's disease is associated with dysfunction of oxygen activation by neutrophils. The findings suggest that defects in leukocytes ability to activate oxygen in Hodgkin's disease may entail deranged regulation of other processes essential for functional activity of polymorphonuclear leukocytes.

Adult↗
PubMed1992

Photodynamic activity of chlorin e6 and chlorin e6 ethylenediamide in vitro and in vivo.

Several parameters of chlorin e6 and its derivative chlorin e6 ethylenediamide have been investigated as these compound are potential sensitizers for photodynamic therapy. A study carried out to compare the cellular uptake of the pigments indicates that chlorin e6 ethylenediamide possesses an enhanced affinity for tumour cells and cellular membranes. Comparison of the uptake in induced sarcoma shows that chlorin e6 ethylenediamide is a much better tumour localizer than chlorin e6. The efficiency of phototherapy with chlorin e6 ethylenediamide is higher than that with chlorin e6. These data show the influence of the substitution of the carboxyl groups in chlorin e6 by ester and amide groups on the photosensitizing properties of the pigments.

Animals↗
PubMed1991

[Chemiluminescence in the peroxidase oxidation of luminol with hydrogen peroxide in various media].

The effects of culture media of various compositions on chemiluminescence developing in peroxidase oxidation of luminol with hydrogen peroxide were under study. The findings evidence that the presence of carbonate and bicarbonate ions in the medium results in a two-staged chemiluminescence kinetics and in more intensive chemiluminescence in the peroxidase-luminol-hydrogen peroxide system. This fact has brought the authors to a conclusion that carbonate and bicarbonate-containing media are more effective for the detection of low peroxidase concentrations by the chemiluminescence technique.

Hydrogen Peroxide↗
PubMed1991

[Chlorine e6-sensitized photoinhibition of thrombocyte aggregation. Participation of active oxygen forms].

It has been shown that photosensitized action of chlorin e6 (Che6) on platelet-rich plasma leads to platelet aggregation inhibition. Che6-sensitized photoinactivation of platelets was intensified in the presence of singlet oxygen interceptor. The aggregation rate of light-irradiated platelets in the presence of Che6 in D2O buffer was higher than in H2O buffer. The participation of active oxygen forms in the determination of platelet function has been considered.

Chlorophyllides↗
PubMed1990

[Oxygen activation by lymphocytes during interaction of HLA antibodies with HLA antigens].

The method of luminol-dependent chemiluminescence was used to detect oxygen activation during interaction of HLA antibodies with HLA antigens expressed on lymphocyte surface. Introduction of specific anti-HLA serum into the lymphocyte suspension leads to a rapid decrease of intensity in chemiluminescence intensity follows. The maximum yield of induced chemiluminescence in case of using a specific antiserum is significantly lower than in the control. The method could be used for detection of HLA antigens on lymphocyte surface.

Antigen-Antibody Reactions↗
PubMed1990

[Arachidonic acid-induced aggregation of human peripheral blood neutrophils in the presence of interceptors of active forms of oxygen].

Arachidonate-induced aggregation of human peripheral blood neutrophils and the influence of certain interreceptors of oxygen active forms (OAF) on its rate were studied. The results obtained have shown that OAF play an important role in the processes of interaction between arachidonate and leucocytes. Regulation of the process of leucocyte aggregation may be realized during arachidonate-induced aggregation of neutrophils, due to interaction of cell-generated OAF with arachidonic acid and its lipoxygenase metabolites.

Antioxidants↗
PubMed1990

[Effects of hyperthermia on certain properties of membranes of HeLa cells].

It has been shown that hyperthermia (45 degrees C, 20-120 min) produces a number of changes in HeLa cells at the plasma membrane level: shedding of membrane glycoproteins; changes in the lectin-induced cell agglutination; the outflux from cells of substances with the nonspecific esterase activity.

Agglutination↗
PubMed1989

[The distribution of chlorine e6 and its derivatives in HeLa cells studied using luminescence microscopy].

The influence of the chemical structure of porphyrin pigments on their accumulation and localization in HeLa cells has been examined by the scanning fluorescence microphotometry. It has been found that the replacement of carboxyl groups of chlorine e6 for methyl and amino groups has no influence on the pigment distributions in cells. All the pigments are bound by cell membrane structures. The chemical modification of chlorine e6 structure is essential for the ability of pigment to be accumulated by cells that can be used to increase the efficiency of cancer phototherapy. The charge and hydrophobic properties of pigment molecules are of great importance for accumulating porphyrin sensitizers by cells.

Chlorophyllides↗
PubMed1988

[Mechanisms of the interaction of the leukemic cell with endogenous regulators of the proliferation of hematopoietic tissue].

A substance inhibiting DNA synthesis in mouse leukemic cells was isolated from the regenerating calf spleen. When added to a suspension of leukaemic cells, this substance is adsorbed on their surface. The following changes in cell features being noticed: 1) a minute decrease in electrophoretic cell motility, 2) a decrease in esterase activity of the cells, 3) an increase in microviscosity of membrane lipids, 4) an increase in the intracellular pH values. With a longer contact with this substance, changes in nuclear chromatin structure were noticed, with special reference to weakened bonds between DNA and proteins. The data obtained are of significance for revealing molecular mechanisms of hematopoietic mediator action on target cells.

Adsorption↗