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Biomedical subjects

S N Cherenkevich

Publications and source records attributed to S N Cherenkevich.

At least 19 recordsLinked to original sources
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↗
PubMed1985

Chemiluminescence of luminol caused by interaction of cytochrome P-450 and cytochrome C with cumene hydroperoxide: comparative studies.

A comparative study of the interaction of cumene hydroperoxide with cytochrome P-450LM2 and with cytochrome C has been undertaken using the chemiluminescence method in the presence of luminol. Considerable differences in the mechanisms of action of both hemoproteins have been revealed with various inhibitors of radical stages, i.e. superoxide dismutase, mannitol, sodium azide, and alpha-tocopherol. It is shown that molecular oxygen participates in the process of hemoprotein-catalyzed hydroperoxide oxidation of luminol.

Animals↗
PubMed1985

[Peroxidase activity of the influenza virus].

The appearance of chemiluminescence has been detected in influenza virus-luminol-hydrogen peroxide system. An effective decrease of its intensity in the presence of oxygen radical scavengers (sodium azide, superoxide dismutase, mannitol, ethanol) is indicative of activated oxygen taking part in the reaction. Increased luminescence in the presence of o-phenanthroline and its suppression by antimycin A suggest that peroxidase-like activity of influenza virus is due to the presence in it of Fe-S-protein.

Animals↗
PubMed1985

[Changes in the activity of hydrogen ions in lymphocytes during the endocytosis of concanavalin A].

Changes of hydrogen ions activity in rat thymocytes were studied during the process of concanavalin A (Con A) endocytosis by cells. A possibility was shown to use fluoresceinisothiocyanate-labeled Con A for measuring pH values in the sites of mitogen localization. It is established that during the action of Con A endocytotic vesicles with low pH value are formed, while the pH value of the cytoplasm is increased. The pH value measured in the sites of mitogen localization depends on the treatment of cells by alpha-methyl-D-mannoside and sodium azide. Mechanisms of acidic-basic equilibrium changes in the cytoplasm of lymphocytes upon cell stimulation with mitogens are discussed.

Animals↗
PubMed1984

[Chemiluminescence of thrombocytes in thrombin-induced aggregation].

Chemoluminescence induced by thrombin and aggregation of thrombocytes as well as effect of aspirin on the reactions were studied. Intensity of thrombin-induced chemoluminescence correlated with accumulation of malonic dialdehyde and hydroperoxides in cells. Chemoluminescence of thrombocytes appears to occur after the thrombin stimulation of cyclooxygenase pathway of arachidonic acid oxidation in cells.

Arachidonic Acid↗
PubMed1983

[pH-dependent conformational changes in thrombocyte proteins].

A study was made of the medium pH influence on structural states of platelets by optical methods. Within the pH range (6-8), two pH induced reversible changes of platelet state were observed. A conclusion is made that the structural rearrangements in platelets induced in the medium by changes in hydrogen ion concentration may involve some rearrangements in platelet proteins, and thus acting as a factor regulating platelet function.

Blood Platelets↗