Search PubMed⌕ Search

Biomedical subjects

S B Cheknev

Publications and source records attributed to S B Cheknev.

At least 19 recordsLinked to original sources
PubMed2006

Binding of zinc cations to human serum gamma-globulin.

Binding of zinc cations to human serum gamma-globulin was studied by molecular ultrafiltration. The content of free metal in the filtrate was evaluated by reaction with o-phenanthroline. Conformation characteristics of the protein were determined by UV spectrophotometry. Our findings suggest that gamma-globulin molecule contains several zinc binding sites differing by corresponding constants and successively occupied with increase in the content of bound metal. The parameters of zinc binding correspond to those obtained in experiments with copper. Conformation status of protein with bound zinc differs significantly from that of protein with bound copper cations.

Cations↗
PubMed2005

Formation of supramolecular aggregations of gamma-globulin as a metal-dependent process.

The presence of copper cations in the solution of human serum gamma-globulin induced the formation of supramolecular forms of the protein. The intensity of this reaction increased with increasing copper concentration. The mechanisms of g-globulin aggregate formation under normal conditions and the possible role of bivalent metal cations in the regulation of protein effector functions are discussed.

Cations, Divalent↗
PubMed2005

Biphasic interaction of gamma-globulin with copper cations.

Interactions of human serum gamma-globulin with copper cations in solution were studied by differential ultraviolet spectrophotometry. Copper in supraphysiological concentrations increases optical density of protein solution, reflecting the effect of gamma-globulin saturation with metal. In physiological and lower concentrations of copper cations we observed hypochromia in the protein absorption spectrum. Conformational changes in g-globulin molecule during interactions with copper by the surface and intramolecular binding sites and possible role of bivalent metal cations in the maintenance of certain conformations of immunoactive serum proteins are discussed.

Cations↗
PubMed2005

Reactions between human serum gamma-globulin and zinc cations.

Interactions of human serum gamma-globulin with zinc cations in solution were studied by differential spectrophotometry in UV light. Supraphysiological concentrations of zinc caused an increment in optical density of protein solution reflecting the effect of gamma-globulin saturation with the metal. Zinc concentrations below physiological led to hypochromism in the protein absorption spectrum. Conformation changes in gamma-globulin during interactions with zinc are analyzed for the surface and intramolecular binding sites and are compared with the effects of copper cations.

Cations↗
PubMed2004

Activity of human lymphocytes in the presence of carbohydrate-containing compounds.

Treatment with chelating agent abolished stimulation of human lymphocyte blast transformation observed in the presence of native microbial glycoproteins. Heparin passed through a column packed with aluminum hydroxide inhibited cytotoxic activity in natural killer cells. We discuss the possibility of regulation of cell functions via modulation of the vector of transport and exchange of metal cations in cell microenvironment and the role of macromolecular compounds containing carbohydrate components in this process.

Adult↗
PubMed2004

Variability of natural killer activity during immunotherapy.

In patients with multiple sclerosis, chronic active hepatitis B, and relapsing genital herpes integral parameters of variability in natural killer activity were higher than in donors. In the dynamics of immunotherapy with IFN preparations (chronic active hepatitis B) and IFN inductor ridostine (relapsing genital herpes) these parameters decreased and approached the normal values. The possibility of using variability of natural killer activity for evaluation of cell function and prediction of the efficiency of immunotherapy is discussed.

Adolescent↗
PubMed2004

Immunomodulating characteristics of Cys-(Pro)3-Glu-Leu hexapeptide under different experimental conditions.

Cys-(Pro)3-Glu-Leu hexapeptide markedly stimulated activity of human natural killers during the cytotoxic test in the presence of autologous serum, but not fetal calf serum. This effect of hexapeptide on natural killer activity was physiological. Conditions are determined under which hexapeptide stimulates the cytotoxicity in a mode ensuring protection of the microenvironment from damage inflicted by own natural killer cytotoxic factors.

Adolescent↗
PubMed2003

[Endogenous biological retranslation in current clinical and biological studies].

The paper generalizes the results of research implemented within the framework of the methodological concept of the Endogenous Biological Retranslation (EBR) for the purpose of finding new data about the immune pathogenesis of multiple sclerosis (MS), whose mechanisms are related with violations of the EBR processes in the body. A possibility is considered to use the priming of interferon (INF) production, as an EBR variant, for evaluating the functioning of the INF system. The thus obtained materials prove convincingly that the experimental approaches, based on priming the blood cells to the IFN production, can be clinically used in the diagnosis and therapy of MS. A new effective combined IFN-therapy scheme for the disease in question was demonstrated. A set of criteria, which makes it possible to prescribe the INF preparations for MS patients with regard for an evaluated response degree of patients' blood cells to them and with regard for a prognosticated efficacy of an assumed treatment is offered. Possibilities of an individualized comprehensive therapy for MS by using the offered experimental approaches are discussed.

Adult↗
PubMed2002

[Clinico-immunological comparisons in evaluation of interferon system functioning in patients with multiple sclerosis].

In search for rational approach for immunotherapy individualization in patients with multiple sclerosis (MS) assigned to interferon (IFN) treatment, an evaluation of IFN-alpha and IFN-gamma production by peripheral blood leucocytes (PBL) under standard induction and exogenous IFN priming in comparison with clinical characteristics was made. Fifteen patients with MS (6 males and 9 females, aged 25-58 years) with verified diagnosis of MS were examined. IFN production priming allowed to obtain characteristics of IFN system deficiency, which could not be detected by standard induction methods. Correlation between induced and primed PBL. IFN-gamma production and MS severity, duration and course was found. Patients with no PBL blood cells dissociate response to IFN-alpha and IFN-gamma exhibited less neurological deficit than those with associations in response. A use of blood cell sensitivity to exogenous IFN in individualization of MS immunotherapy with IFN-medications is discussed.

Adult↗
PubMed2001

Correlations between in vitro effects of preparations of interferon and its inducers on blood cells in patients with multiple sclerosis.

We studied in vitro production of interferon-alpha and interferon-gamma by peripheral blood leukocytes from 15 patients with multiple sclerosis. The priming effects of interferon preparations weakly correlated with interferon-alpha production by leukocytes from patients with multiple sclerosis, but negatively correlated with interferon-gamma production. The effects of interferon inducers in most cases positively correlated with its spontaneous production. We found a weak positive correlation between the priming effect of natural interferon-alpha and the effect of recombinant interferons. There were positive or strong positive correlations between the effects of recombinant interferons on leukocytes from patients with multiple sclerosis. The relationship between the effects of medicinal interferon inducers and interferon preparation varied from negative to strong positive correlations. These data suggest that correlation analysis can be used for dynamic control and elaboration of methods for combined immunotherapy of multiple sclerosis with various interferon preparations or interferon and its inducers.

Acridines↗
PubMed1999

[Active oxygen metabolites in provision and control of natural cytotoxic reactions].

Whether the redox active compounds that are able to generate and capture free oxygen radicals utilized in natural cytotoxicity (NCT) are involved in the provision and control of NCT in the body of man and animals is discussed. Evidence is given for the participation of endogenous metal-binding peptido(proteo)glycans (MBPPG) in the establishment and maintenance of regulatory balance in the complex of NCT reactions. Cyanobacterial exometabolites and their related metal-binding amphipathic compounds yielded in the exosystem was substantiated to be involved in the rational limitation of lymphocytic cytotoxicity. The findings suggest that exogenous redox active microbial products exert their action on NCT cells by changing the rate of generation and capture of free oxygen radicals by exogenous MBPPG.

Animals↗
PubMed1999

[Natural cytotoxicity in complex of cell interactions].

The paper summarizes the results of studies on the mechanisms and factors that do prevent natural killer (NK) cells from their cytotoxicity against the body's own cells. The findings support the fact that three-level mechanisms are involved in the protection of the body's cell from NK cell damage. The mechanisms of the first endogenic level are ensured by the factors which form a regulatory balance in the complex of NK cell responses. Those of the second endogenic level are ensured by the factors that participate in the transfer and exchange of metallic cations in the cell microenvironment. The third (exogenous) level mechanisms have been found in the study of the lymphocytic functions of cyanobacterial exometabolites and their derivatives from tap water probes. The products tested are able to block the generation of the free oxygen radicals utilized by NK cells in their lethal shock. A limitation of NK cell cytotoxicity seems to an important condition for non-cytotoxic regulatory NK cell interactions with immune and other cells.

Animals↗
PubMed1999

[Functional organization and mechanisms of human intrinsic regulation of natural cytotoxicity system].

The paper gives a detailed account of the specific features and mechanisms of natural cytotoxicity (NCT) reactions in health and in disease. The assumption that the system autonomically functions has been substantiated and experimentally verified. There is evidence for that it is able to self regulate and to be controlled by endogenous or exogenous factors. If there is a biological expediency for NCT to be limited, which would prevented the intrinsic unchanged cells from lesions when they interact with the system's activated cells is first discussed. It has been found that there are three organizational levels of the mechanisms that rationally limit NCT. These include intra-systemic, extra-systemic endogenous and exogenous. The theoretical result of the studies is a basically new methodology of fundamental developments in the area of immunobiological surveillance. It assumes that environmental microbial factors have a limiting rather inducing influence on NCT, which prevents intact cells from lesions in cytotoxic reactions.

Animals↗