Biomedical subjects

I A Tumanova

Publications and source records attributed to I A Tumanova.

6 recordsLinked to original sources

PubMed1991

[Quantitative characteristic of circulating immune complexes in patients with lupus erythematosus and central nervous system disorders].

Molecular weight and concentration characteristics of immune complexes (IC) from 19 sera of patients with systemic lupus erythematosus (SLE) and CNS impairment have been obtained by the rapid nephelometry assay. Basing on cranial CT findings, the examinees were divided into 2 groups. Group I included patients with cerebral cysts and local dilation of subarachonid spaces, group II those with the above dilatation or that of ventricles of the brain. Small-size IC were registered in 14 sera, their relative molecular mass being under the values derived for donors and SLE patients without CNS affections whereas their level exceeded such in donor sera. Larger IC relative concentrations were seen in group I patients than in group II ones (34 +/- 13 and 18.7 +/- 12, respectively). Five patients failed to demonstrate IC. The presence of small-size IC in high concentrations may be considered a marker of CNS involvement in SLE, the highest concentrations suggesting local impairment of the brain.

Adolescent↗

PubMed1987

Production and characterization of heat-aggregated IgG complexes with pre-determined molecular masses: light-scattering study.

A method for the preparation of model immune complexes of heat-aggregated human IgG with predetermined molecular masses is described. IgG complexes with different molecular masses were produced by incubation of human IgG for 20 min at 63 degrees C, the protein concentration varying from 0.5 to 5 mg/ml before heat treatment. To determine the bulk of IgG molecules included in the aggregates, the IgG complexes obtained were precipitated by 7% polyethylene glycol. The relative molecular masses of the heat-aggregated IgG preparations were calculated using light-scattering measurements, being expressed as the number of IgG molecules per aggregate (MIC/MIgG). The dependence of the MIC/MIgG value upon IgG concentration in aggregation was plotted. This dependence makes it possible to produce IgG model immune complexes with pre-determined molecular masses.

Antigen-Antibody Complex↗

PubMed1986

[Complement-binding activity of myeloma and normal immune complexes].

The comparison of complement-fixing capacity of simulated immune complexes formed by normal IgG and IgG, isolated from serum of patients with multiple myeloma, has been performed. In both cases a non-linear dependence of complement-fixing capacity on the complex molecular mass was demonstrated, it being higher for myeloma proteins. Complement supplementation to high molecular complexes leads to their collapse, with normal immune complexes destroyed at lower molecular masses. Heat-aggregation of myeloma immunoglobulins leads to the formation of simulated immune complexes of lower molecular mass compared to normal proteins.

Antigen-Antibody Complex↗

PubMed1984

[Comparison of the complement-binding activity of model immune complexes of different molecular weights].

The authors studied and compared the complement-fixing activity of model immune complexes with different molecular mass. The complement-fixing activity of the complexes was found to be linearly independent of the molecular mass, being mainly determined by the size of the complex, and to be slightly dependent on the concentration of aggregated immunoglobulins. As far as the aggregates with a molecular mass over 20 IgG are concerned, addition of complement leads to the dissociation of the complexes.

Antigen-Antibody Complex↗

PubMed1983

A method for quantitative determination of average masses and concentrations of circulating immune complexes in human sera.

A method for rapid determination of average masses and concentrations of circulating immune complexes in human sera is suggested. It is based on the dissimilarity in solubilities of immune complexes with different masses in the presence of polyethyleneglycol. Light-scattering intensities are measured by a laser nephelometer after adding to the serum of PEG in two different concentrations. The experimental values of the average masses and concentrations are calculated using calibration curves. The calibration curves are plotted for model immune complexes with different average masses obtained by heat-aggregation of IgG at various concentrations. This technique has been employed for determination of the average masses and concentrations of circulating immune complexes in 17 patients suffering from systemic lupus erythematosus and in 8 control individuals.

Antigen-Antibody Complex↗

PubMed1982

[Complement-binding capacity of aggregated immunoglobulins of different molecular weights].

The complement-fixing capacity of aggregated immunoglobulins with varying molecular weights has been explored. It has been demonstrated that as the molecular weight of a complex rises, the complement-fixing capacity increases. The amount of unfixed complement depends nonlinearly on the concentration of complement added and aggregated complexes in solution. The size of the complexes rather than their concentration plays the key role in the measurement of the complement-fixing capacity of aggregated immunoglobulins.

Animals↗