Biomedical subjects
Publications and source records attributed to V V Lavrent'ev.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Pathological immunoglobulins (IgG from patients with multiple myeloma and IgM from patients with Waldenström macroglobulinemia) have been shown to possess hydrophylic-lipophylic balance (HLB) which differed from normal Ig HLB. HLB deficiency in pathological proteins was due to the increase of hydrophobic area at the surface of protein globe, which was the reason for different normal and abnormal Ig orientations at the aqueous NaCl solution--air interface. The normal IgG and IgM had horizontal orientation while abnormal ones had vertical orientation. Both normal and abnormal Ig changed their orientation in monolayers as a result of sodium deoxycholate processing. The change in orientation depended on protein molecules interaction with single molecules or micelles of sodium deoxycholate.
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.
Explore the source record for details and available documents.
The surface denaturation kinetics of mouse normal IgG and IgGl kappa secreted by myeloma MOPC-21 was studied in monomolecular layers at the air-water interface. Based on the denaturation kinetics data the orientation of the native IgG molecules was determined relative to the interface surface, which turned out to be horizontal for normal IgG and vertical for myelomic ones. As regards the orientation in the monolayers and the rate of surface denaturation, the mouse normal IgG were found to be similar to normal IgG from other species. Like human myelomic IgG, MOPC-21 IgGl kappa differed from normal IgG in both the orientation and lesser native structure stability.
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.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The authors studied the possibilities of applying thermistography to the determination of IgE in human blood serum. It was shown that IgE is thermolabile, precipitating at the equivalent antigen/antibody ratios and at pH 5.5-7.5 as in the case with other immunoglobulins. Thermistography may be applied to the determination of the IgE level in the blood serum of patients and normal subjects.
Explore the source record for details and available documents.
Adsorption of human serum albumin (HSA), egg albumin (EA), immunoglobulin G (IgG) and immunologic reactions occurring between them on silicon surface were studied by ellipsometry. Adsorption of HSA, IgG and antibodies on the monolayer of antigen is monomolecular in their isoelectric points and can be depicted by Langmuir's equation. Adsorption of EA is polymolecular apparently because of great tendency of the protein to aggregation in aqueous solutions. Comparison of the magnitudes of the protein monolayer thickness and areas per adsorbed molecule with their linear dimensions indicate that they preserve their native conformation. This allows an evaluation of the maximum number of the active sites (as approximately four) on the antigen surface accessible for antibodies and the adsorption constants for specific and nonspecific adsorption of IgG.
The mechanism of complement complexing with immunoglobulins in the solution has been shown to depend on the nature and structure of the reagents. The maximum complexing rate can be recorded during interaction of the native complement with aggregated antibodies. The complexing rate varies with the complement type. Guinea pig fresh serum is the most active in this respect.
The process of specific complex formation of different human immunoglobulines M, G and A with IgG antibody against them was investigated by the thermistor method. It was shown that the rate and intensity of the process vary with the types of interacting immunoglobulines, and that they reach maximum for IgM. From the character of the curves obtained a judgement can be formed about the immunoglobulin type being synthesized at the given moment. Disturbance of the inner structure of immunoglobulin macromolecules, e.g. during heating, leads to changes in the mechanism of complex formation, it being important what particular component underwent denaturation.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.