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Biomedical subjects

Iu P Petrov

Publications and source records attributed to Iu P Petrov.

At least 19 recordsLinked to original sources
PubMed2002

[Cell interaction with extracellular proteins during two-phase polymer system formation].

A modified method of investigation of surface properties of cells and proteins with the help of a two-phase polymer system dextran-500/polyethylenglycol-6000 was used. This method is based on changing the kinetics of two-phase system partitioning into phase on adding cells or macromolecules. These changes were registered by measuring the top phase optical density during the system partitioning at 500 nm. Cell lines L (NCTC clone 929), LS and A431, human keratinocytes and platelets, collagen I, laminin-1, laminin-2/4, and fibronectin were studied. The interaction between collagen and all cell types with the formation of complexes takes place during co-partitioning of cells and proteins in the two-phase system. Laminins differ in surface properties and in interaction with cells. Laminin-1 makes preferable complexes with cells of monolayer subline L (NCTC clone 929), but not with cells of suspension subline LS. No interaction of laminin-2/4 with L cells was detected, but, in contrast to laminin-1, this protein has the affinity to A431 cells. No interaction of L cells with fibronectin were detected.

Animals↗
PubMed2001

[Study of surface properties of chloroplasts of some beans using a binary phase polymer system].

The surface properties of chloroplasts in leaves of some leguminous plants--Pisum sativum, Trifolium paratense, Melilotus album, and Vicia cracca--were investigated, based on the analysis of phase formation kinetics of the aqueous polymeric two-phase system dextrane-500/polyethyleneglycol-6000. The surface properties of chloroplasts have been shown to display both species- and sort-specificity. A specific influence of chloroplasts of melilot and non-chlorophyllic pea lines on phase formation kinetics has been noticed.

Chloroplasts↗
PubMed2001

[The effect of medium viscosity on actin polymerization].

A comparative study of the influence of two factors--excluded volume effect, and medium viscosity--on actin polymerization was carried out. Dextrane--500 (1%), poly(ethylene)glycol--6000 (2.7%), Ficol (1.8%), methyl cellulose (0.04%), saccharose (10%), and glycerine (10%) were used for creating a viscous medium. The concentrations of these agents in actin solution made approximately the same viscosity commensurable with the cytoplasm viscosity. By this it was possible to bring conditions of actin polymerization in vitro closer to those in vivo. It is shown that the medium viscosity in contrast to the excluded volume effect, prolongs the nucleation phase during actin polymerization. A conclusion is made that in the cell both factors can be involved in the regulation of actin filament formation.

Actins↗
PubMed2000

[Dependence of the kinetics of forming phases of a two-phase polymeric system on actin state].

New analytical possibilities of biological macromolecule partition in a two-phase polymer system (dextran-500/polyethyleneglycol-6000) were investigated. The technical principles were based on the fact that optical density of the system changes during phase formation. Various actin forms were investigated. Unlike G-actin, F-actin increases the speed of phase formation. Different actin isoforms exert different influence on this process. The kinetics of the partition system into phases makes it possible to figure out the picture of native G-actin damage. The two-phase polymer system has been shown to be capable of supporting the native properties of actin for not less than 6 days at 20 degrees C. An assumption is made that two-phase systems can be used for imitating the intracellular medium in studies on actin functional characteristics.

Actins↗
PubMed2000

[Features of formation of phases of dual-phase polymeric system in the presence of collagen I, laminin I, and their mixtures].

A study was made of the phase formation kinetics of a two-phase aqueous polymer system, consisting of 7.8% (w/w) dextran-500 and 4.6% (w/w) polyethylene glycol-6000, in the presence of various concentrations of collagen (0.07-0.20 mg/ml), laminin I (0.01-0.03 mg/ml) and their mixture. The phase formation was evaluated by registration of its optical density on a spectrophotometer. The obtained two-phase polymer system optical density curves and also the partitioning coefficients for the studied objects depend on surface properties of these objects. It has been shown that the surface properties of collagen I and laminin I differ according to differences in their molecules conformations, and that the phase formation kinetics points to their interaction during a mutual partitioning of these proteins in the system. The authors made a conclusion that collagen I and laminin I in the two-phase polymer system conditions could make complexes.

Biopolymers↗
PubMed1987

[Changes in the karyotype and surface properties of L cells during the adaptation of a suspension culture to monolayer growth].

Distribution of cells (L929, LS, LSM) in the two-phase polymer system was studied in addition to characterization of their karyotypes. In the course of LSM cell passages, the increased ratio of cells with a reduced number of chromosomes was found. The results obtained show that in the process of adaptation of the suspension cell culture to the growth as monolayer (the culture of LSM cells) the changes of the cell surface do not dependent on the chromosome number.

Adaptation, Physiological↗
PubMed1987

[Early changes in the state of the cell surface and nucleoid of irradiated Ehrlich ascites carcinoma cells].

For cells of Ehrlich ascite carcinoma, irradiated by the dose of 10 Gy, a decrease in the coefficient of cell distribution in the two-phase polymer system--dextrane-polyethylene-glycol and an increase in the nucleoid viscosity are shown. The values of both indices characterizing the state of the cell surface and nuclear DNA by the same way have changed in time after irradiation: the maximum effect was observed 1 hour after irradiation and the normalization of the both indices was marked 5-6 hours after it.

Animals↗
PubMed1986

[Surface changes in irradiated thymocytes studied by partition in 2-phase systems and electrophoresis].

A study was made of thymocyte surface changes 1-6 hour after the irradiation in a dose of 4 Gy by means of two phase partition in dextran-polyethylenglycole systems and of electrophoretic mobility registration. A decrease in the two phase partition coefficient (by 20% per cent in one hour after irradiation) was registered. The electrophoretic mobility of irradiated cells did not change.

Animals↗
PubMed1985

[Surface properties of L cells studied by countercurrent distribution in a 2-phase polymer system before and after cyochalasin B and colcemid exposure].

A study was made of the effect of cytochalazin B and cocemid on the line L cells of monolayer and suspension culture studied by the method of counter-current distribution in two-phase polymer system dextran-500 - polyethylenglycol-6000. It has been shown that cytochalazin B caused a decrease in the partition coefficient of both the subline cells irrespective of the growth phase of cell population. Colcemid decreases the partition coefficient in the log-phase of cell culture but increases it in the stationary phase. Effect of colcemid is not associated with the accumulation of metaphase cells in the cell population.

Animals↗
PubMed1982

[Countercurrent distribution in a 2-phase polymer system of cultured cells following their exposure to trypsin, versen, dimethyl sulfoxide and suboptimal temperature].

A study was made of the effects of trypsin (0.25%) EDTA (0.02%), DMSO (10%) and suboptimal temperatures (16-18 degrees C) on the line L cells of monolayer and suspension cultures by the method of counter-current distribution in two-phase polymer system Dextran-500/poly (ethylene) glycol-6000. It has been shown that these agents cause the increase in number of cells with low partition coefficient, which is most expressed in the population of monolayer subline cells.

Animals↗
PubMed1981

[Countercurrent distribution of L line monolayer and suspension cell cultures in a 2-phase polymer system].

The distribution of two sulines of L cells, differing in adhesive properties (monolayer and suspension cultures), have been investigated using polymer two-phase system dextran-500-polyenthylenglycol-600. By counter-current distribution it has been shown that most of the cells growing in monolayer have low coefficients of partition, unlike cells grown in suspension having a high coefficient of partition. It is supposed that differences revealed in properties of the cell surface may be associated with the ability of cells to form adhesive contacts.

Animals↗