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Biomedical subjects

N A Matveeva

Publications and source records attributed to N A Matveeva.

64 records · Page 4Linked to original sources
PubMedDate not supplied

[Comparative study of normal and myelogenic immunoglobulin G in monomolecular layers at air-water and oil-water interface].

Orientation of normal and 12 abnormal immunoglobulins G (IgG) isolated from serum of patients with multiple myeloma in monomolecular layers at 0.15 M NaCl--air and 0.15 M NaCl--octane interfaces has been studied. Majority of abnormal proteins was found to be oriented vertically at phase border of both types unlike normal human IgG which had horizontal orientation. Abnormal IgG differed from the normal one also by lower resistance to surface denaturation at air--water interface. Thus the monomolecular layer method was demonstrated to be capable of distinguishing normal and abnormal IgG.

Air↗
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[Orientational, conformational stability and surface potential of immunoglobulins in monomolecular layers].

Orientation, resistance to surface denaturation and surface potential of bovine and horse immunoglobulin G (IgG) and also of pig IgG-antibodies against DNP and DNS groups on the surface of NaCl solutions of various concentrations have been studied by monomolecular layer method. High conformational stability of IgG molecules of all the species was confirmed. At the surface of NaCl solutions with concentrations 0.15--0.5 M immunoglobulins of all species from monolayers consisting of practically non-unfolded molecules with such an orientation, that all the fragments of IgG molecule are located horizontally. Beyond the limits of this native structure stability zone the rate of surface denaturation is directly proportional to NaCl concentration in the solution. The values of surface potentials of all immunoglobulins under study are close to each other and change little with the surface denaturation.

Animals↗
PubMedDate not supplied

[Conformational stability of immunoglobulin G in monomolecular layers at aqueous NaCl solution-octane interfaces].

Resistance to surface denaturation of human and horse immunoglobulin G (IgG) molecules at aqueous NaCl solution--octane interface as a function of aqueous phase pH and NaCl concentration has been studied by monomolecular layer method. Higher conformational stability of these proteins at oil--water interface as compared to that at air-water interface has been demonstrated. At aqueous solutions of 0.15 M NaCl concentration and pH range from 2.8 to 8.0 units no conformational changes were fixed. With the change of NaCl concentration in aqueous phase from 0.15 to 2.0 M at neutral pH horse IgG molecules did not lose their native conformation. Human IgG molecules were only slightly undergoing denaturation process under the same conditions.

Animals↗
PubMedDate not supplied

[Study of Monomolecular layers of immunoglobulin G by IR-spectroscopy].

The deposited immunoglobulin G (IgG) monomolecular layers consisting of native protein molecules oriented either horizontally or vertically towards the Si internal reflection plate, and also of molecules, denatured in monolayers at air-water interface have been studied by attenuated total-reflection (ATR) IR-spectroscopy technique. It was shown that deposition of IgG molecules on Si surface from monolayers at air--water interface did not change conformation and orientation of the molecules. The value of monolayer thickness correlates with the IgG molecule dimensions calculated from X-ray diffraction data. It was also established that beta-conformation prevails in the secondary structure of both native and denaturated molecules.

Animals↗
PubMedDate not supplied

[Relation between surface denaturation of immunoglobulin G in monolayers and the pH of the solution].

Dependence of surface denaturation kinetics of rabbit immunoglobulin G (IgG) in monomolecular layers at air-water interfaces on the substrate pH has been studied. By measuring the surface potential the drift of the isoelectric point of IgG in monolayer as compared to that of the bulk aqueous phase in the direction of high pH values has been demonstrated. The IgG molecule displays the greatest stability in monolayer at the isoelectric point. An increase of protein molecules positive charge in the region of 7.5--5.5 pH units is not sufficient for prominent acceleration of surface denaturation in comparison to the isoelectric point. A decrease of the substrate pH lower than 5.5 units is followed by the growth of the rate of surface denaturation which is directly proportional to [H+] concentration in the substrate. In the same region of pH values compensation of charges of protein molecules takes place, so that the surface potential is not changed and does not depend on the rate of molecular denaturation. High conformational stability of IgG molecules in monomolecular layers at air water interface has been confirmed.

Animals↗
PubMedDate not supplied

[The dynamic physical development of schoolchildren in Nizhni Novgorod].

In the past 55 years, the trends in the physical development of school children of a large industrial city have been in agreement with the global ones in the growth and development of children and adolescents. In the past decade, there have been unfavourable tendencies in the physical development of schoolchildren. The physical development of children is an indicator of the social and economic status, living conditions, and the environment. Follow-ups should be an obligatory element of monitoring the population's health.

Adolescent↗
PubMedDate not supplied

[Heavy metal content of the hair of children in industrial cities].

Heavy metals are most common pollutants in large industrial cities. Differences were first shown in the distribution of concentrations of toxic and biogenic heavy metals in the hair of children. Zinc and copper had dispersion close to normal values, whereas lead, cadmium, and nickel had asymmetric dispersion. Scales were first developed for rating the levels of heavy metals in the children's hair in cities. A typology of microareas was also first developed by the level of metal pollution. The permanent stay of children in the highly polluted areas causes a high accumulation of lead in the hair and it is a risk factor of morphofunctional abnormalities and chronic diseases.

Age Factors↗