Biomedical subjects

N P Kuznetsova

Publications and source records attributed to N P Kuznetsova.

At least 19 recordsLinked to original sources

PubMed2006

Cell-free and cell-bound circulating DNA in breast tumours: DNA quantification and analysis of tumour-related gene methylation.

Tumour development is characterised by the increased circulating DNA (cirDNA) concentration and by tumour-related changes in blood plasma DNA. Concentration of cirDNA and methylation of RARbeta2, RASSF1A and HIC-1 gene promoters were investigated in cell-free and cell-surface-bound fractions from healthy donors, patients with breast cancer, and patients with breast fibroadenoma. Tumour development was shown to lead to significant changes in the distribution of cirDNA between cell-free and cell-surface-bound fractions. Analysis of RARbeta2 and RASSF1A methylation in the total cirDNA provides 95% diagnostic coverage in breast cancer patients, 60% in patients with benign lesions, and is without false-positive results in healthy women. Results of the study indicate that methylation-specific PCR of RARbeta2 and RASSF1A genes based on the total cirDNA combined with the quantitative analysis of cirDNA distribution between cell-bound and cell-free fractions in blood provide the sensitive and accurate detection and discrimination of malignant and benign breast tumours.

Breast Neoplasms↗

PubMed2005

Plasma content of extracellular nucleic acids in donors and patients with mammary tumors.

The concentrations of extracellular DNA and RNA were measured in the plasma of donors and patients with fibroadenoma and breast cancer. The content of extracellular DNA surpassed the normal in 80% plasma samples from patients with mammary tumors. Extracellular RNA was detected in 30% plasma samples from donors and patients with breast tumors. No correlations were found between plasma concentration of extracellular DNA and size and stage of tumor growth. Hence, measurement of extracellular DNA in the plasma of patients can be used only as an accessory test for tumor diagnosis.

Breast Neoplasms↗

PubMed1998

Synthesis, physico-chemical and biological properties of crosslinked modified hemoglobin.

Polymer aspects of polycondensation of pyridoxylated hemoglobin with glutaraldehyde have been considered. On the basis of the investigation of reaction kinetics, the mechanism of chemical crosslinking of hemoglobin molecules into oligohemoglobin is proposed. Owing to the statistical character of the reaction, the resulting macromolecules are polydisperse with respect to the degree of modification of hemoglobin amino groups, and size of oligohemoglobin molecules. The formation of hemoglobin oligomers was studied by varying the following reaction conditions: pH, the components ratio, and their concentrations. It is shown that the net electric charge of the oligohemoglobin molecule depends on the terminating agents. However, these agents have no effect on the electrophoretic mobility of erythrocytes in oligohemoglobin solutions. The efficiency of oxygen transport of these solutions is close to that of human blood erythrocytes. Oligohemoglobin circulation in the blood of animals after intravenous infusion leads to rapid removal of low molecular weight fractions from blood and to the accumulation of high molecular weight fractions in plasma. The period of half-release of oligohemoglobin from the organism is 14-16 h.

Animals↗

PubMed1997

Microdisperse form of immobilized hemoglobin modelling the erythrocytes.

Disperse systems based on hemoglobin sorption immobilization in reticular carboxylic polyelectrolytes are proposed as model of erythrocytes. The efficiency of oxygen transport of these systems is much higher than that of native hemoglobin and is comparable with the gas transport of erythrocytes. This is believed to be due to highly selective sorption of hemoglobin in microdisperse forms of permeable polyelectrolytes. Microparticles of immobilized hemoglobin exhibit high local concentration of hemoglobin: the protein mass being one order of magnitude than that of polymer-carrier. Besides, it is presumed that structure of the carboxylic polyelectrolyte matrix is a polymer analog of 2,3-diphosphoglycerate. Microdispersion of immobilized hemoglobin exhibits a aggregative resistance and have identity of surface charge with erythrocytes. Studies in vivo have revealed biocompatibility of immobilized hemoglobin.

Adsorption↗

PubMed1996

[Increase in oxygen-transporting efficiency of hemoglobin when chemically modified].

Polycondensation of human hemoglobin with glutaraldehyde premodified with reagents bearing acid groups (glutamic acid or sodium bisulfite), has been carried out. The resulting modified hemoglobin displays better oxygen transport characteristics in comparison with native hemoglobin.

Allosteric Regulation↗

PubMed1990

[Modification of hemoglobin by glutaric aldehyde and electrochemical properties of the conjugates].

Electrochemical properties of macromolecules of modified haemoglobin obtained by polycondensation with glutaric aldehyde have been investigated by means of potentiometric titration, PAG-electrophoresis, ion-exchange chromatography, and (for evaluation of isoelectric point) distribution between two aqueous polymeric phases. Introduction of additional functional groups into the macromolecule is possible by using various agents blocking polycondensation, which makes it possible to change the resulting charge and the isoelectric point.

Aldehydes↗

PubMed1990