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Biomedical subjects

S G Zhabin

Publications and source records attributed to S G Zhabin.

At least 19 recordsLinked to original sources
PubMed2004

[Identification of mutation of the phenylalanine hydroxylase gene using an automated DNA sequencer].

Mutations were studied in phenylalanine hydroxylase gene of phenylketonuria patients from Kemerovo oblast and Altaiskii krai (15 and 2 families, respectively). The following mutations were identified in exons of this gene: R408W, R261Q, R243Q, Y414C, Y386C, P281L, Y168H, R68S (lead to amino acid substitutions), R243X (leads to stop codon formation), and three splice site mutations (IVS12nt 1g-->a, IVS2nt-13t-->g, IVS7nt 1g-->a).

Automation↗
PubMed2003

Review: immunomodulatory activity of pregnancy-associated plasma protein-A.

This mini-review highlights the growing number of indications for the immunological importance of pregnancy-associated plasma protein-A (PAPP-A), which is a remote member of the alpha-macroglobulin plasma protein family. PAPP-A can bind a variety of cytokines and specifically cleave a binding protein for insulin-like growth factors, thereby serving as a modulator of cytokine activity. Important immune functions, such as lymphocyte proliferation response to alloantigens and lectins and expression of HLA-DR molecules are predominantly suppressed in vitro by PAPP-A. It is likely that the immunoregulatory properties of PAPP-A are very similar to that of alpha 2-macroglobulin. The experimental data allows us to suppose that PAPP-A serves to prevent the recognition of the fetus by the maternal immune system and to suppress locally the host's immune response to the tumour.

Adjuvants, Immunologic↗
PubMed1997

The effects of alpha 2-antiplasmin complex and alpha 2-antiplasmin on the secretion of IgG and IgM by cultured human mononuclear cells.

We tested alpha 2-antiplasmin (AP) and its complex with plasmin (PL) for their capacity to modulate spontaneous secretion of immunoglobulins (Ig) G and M by mononuclear cells (MNC). MNC were obtained from peripheral blood of 10 donors (5 males and 5 females) and cultured for 7 days in the presence of various concentrations of AP and AP-PL complex. The 18 hr incubation of MNC with AP-PL complex resulted in a dose-dependent increase in IgG and IgM secretion but the stimulatory effect was less significant than under conditions of incubation of MNC with the complex during a 7 day culture period. The AP-PL complex-induced stimulation occurred only in the cultures in which the dose of the complex was either close to or higher than the mean value of the complex levels in plasma of healthy donors. Elevation of IgG secretion in AP-PL complex-treated cultures from females was slightly higher than in those from males. No significant change in IgG and IgM secretion was observed in the presence of native AP.

B-Lymphocytes↗
PubMed1995

Interaction of human pregnancy-associated plasma protein-A with serine proteinases.

Human pregnancy-associated plasma protein A (PAPP-A) inhibited significantly the proteolytic activity of bovine trypsin and human plasmin. Trypsin or plasmin treatment of PAPP-A resulted in the generation of a major 85 kDa component and the rapid cleavage of internal thiol esters. The results indicated that both of these serine proteinases bound in a 1:1 stoichiometry to PAPP-A. The PAPP-A-bound enzymes were found to be enzymatically active towards small synthetic substrates and inaccessible to inactivation by soybean trypsin inhibitor and alpha 1-proteinase inhibitor. The mechanism of proteinase inhibition was likely to be entrapment, as described for alpha 2-macroglobulin.

Amino Acid Sequence↗
PubMed1994

Changes in tissue distribution of rat alpha 1-macroglobulin and pregnancy-associated alpha 1-glycoprotein after inflammatory injury.

Antiserum against rat alpha 1-macroglobulin (alpha 1MG) was produced in rabbits. Antiserum against rat pregnancy-associated alpha 1-glycoprotein (PAG) was obtained by immunization with a partly purified PAG preparation and absorption of the serum with male rat serum. Acute inflammation was produced in non-pregnant female rats by a single intramuscular injection of turpentine. The concentrations of both macroglobulins in the serum and in tissue extracts were measured by rocket immunoelectrophoresis at various times up to 7 days after injury. Inflammation produced in the rats resulted in moderately elevated serum levels of these proteins soon after injury. At first, alpha 1MG levels in a number of tissues (heart, lung, kidney, spleen, pancreas, uterus and ovary) were depressed markedly; they then stabilized. The elevated serum concentrations of alpha 1MG remained unchanged during inflammation. The store of PAG in the tissues was rapidly depleted and its serum level decreased to a normal value 7 days after injury. Our findings indicate that alpha 1MG plays a more important role in maintenance of the proteinase inhibitory potential in the rat than does PAG.

Acute-Phase Reaction↗
PubMed1994

[The effect of plasmin-modified proteinase inhibitors on macroglobulin production by human blood mononuclear cells in culture].

A study was made of the influence of plasmin (PL) complexes with alpha 2-macroglobulin (MG) and alpha 2-antiplasmin on secretion of MG, pregnancy-associated alpha 2-glycoprotein (PAG), and pregnancy-associated plasma protein A (PAPP-A) by mononuclear cells (MC), obtained from human peripheral blood. It has been shown that incubation of the MG-PL complexes with MC resulted in the increase in concentrations of all these macroglobulins (MG, PAG, and PAPP-A) in supernatants of cultured MC. We revealed the same effects of AP-PL with regard to the secretion of PZP and PAPP-A. However, this complex was found to suppress MG production by cultured MC. The effects found were dose dependent and some of them differed greatly in men and women, resp.

Cells, Cultured↗
PubMed1993

[Hepatocyte receptors for proteinase inhibitor complexes with plasmin].

Hepatocyte receptors have been found for such complexes as alpha 2-macroglobulin-plasmin, pregnancy-associated plasma protein A-plasmin, and pregnancy-associated alpha 2-glycoprotein-plasmin, molecular masses of these receptors being estimated. The proteinaceous component of hepatocyte membranes contains heavy chains of plasmin and a 50 kDa fragment of plasmin molecule. These chains and the fragment are able to bind the native alpha 2-antiplasmin. Using immunoblotting no hepatocyte receptors for native macroglobulins, and alpha 2-antiplasmin-plasmin, alpha 1-proteinase inhibitor were detected.

Cell Fractionation↗
PubMed1991

[Comparative study of immunosuppressive properties of pregnancy- associated protein A, alpha 2-glucoprotein and alpha 2-macroglobulin].

Effects of high-molecular proteinase inhibitors on spontaneous and mitogen-induced lymphocyte proliferation were examined in males and pregnant and non-pregnant females. All three proteins, A protein, alpha 2-glycoprotein, and alpha 2-macroglobulin were found to be potent immunosuppressors and their activity was determined by the stage of pregnancy, the dose and mode of mitogenic lymphocyte stimulation.

Culture Media↗
PubMed1990

[A comparative evaluation of the use of immunoturbidimetry in clinical practice].

A variant of immunoturbidimetry available for any clinical diagnostic laboratory has been developed. The data of measurements of immunoglobulins, albumin, alpha 2-macroglobulin and some other proteins of pregnancy in the blood serum and other biologic fluids, carried out by immunoturbidimetry, coincided with the findings of radial immunodiffusion and rocket immunoelectrophoresis, but immunoturbidimetry is more rapid and simple.

Female↗
PubMed1990

[The detection of streptococcal cell-wall proteins that form complexes with human macroglobulins].

The composition of the extracts of the cultures of individual streptococcal strains, studied by immunoblotting techniques, has been shown to contain proteins with a molecular weight of 70-80 KD. These proteins have pronounced affinity to human macroglobulins: alpha-macroglobulin, alpha-glycoprotein associated with pregnancy and protein A. The significance of this phenomenon on the cellular and somatic levels is discussed.

Bacterial Proteins↗
PubMed1990

[An immunoenzyme method of determining pregnancy-associated alpha 2-glycoprotein].

Methods for purification of pregnancy-associated alpha 2-glycoprotein, obtained antibodies to it, and enzyme immunoassay of this protein are described. Enzyme immunoassay permits measurement of this protein in blood serum and mononuclear cell cultures in a wide range of concentrations. The method sensitivity may be improved by removing the antibodies cross-reacting with animal proteins.

Female↗
PubMed1990

[Distribution of alpha 2-macroglobulin and pregnancy-associated protein A and alpha 2-glycoprotein in human placenta].

By means of immunoperoxidase technique staining localization in the mature placenta of a number of highly molecular proteins--alpha 2-macroglobulin and associated with pregnancy alpha 2-glycoprotein and protein-A--has been determined. These proteins are predominantly determined in syncytiotrophoblast and decidual cells. Similarity in distribution of the proteins in question is determined not only by identity of their receptors, but is evidently caused by community of their functional properties.

Decidua↗