Biomedical subjects
Publications and source records attributed to A V Lepekhin.
Study of the proliferative potential and immunophenotype of lymphocytes and cytokine-producing capacity of mononuclear cells in patients with chronic tick-borne encephalitis virus antigenemia showed changes in T cell lymphoproliferative response, relative content of T cells and T helper inductors, immunoregulatory index, and imbalance in the production of immunoregulatory Th1 and Th2 cytokines.
The structure of lymphocyte and erythrocyte plasma membrane in patients with long persistence of tick-borne encephalitis virus was studied using fluorescent probes pyrene and 1-anilinonaphthalene-8-sulfonate. The authors analyze the clear-cut disorders in the membranes of both lymphocytes and erythrocytes in viral tick-borne-encephalitis from the viewpoint of generalized involvement of cell membranes in infectious process.
Study of the surface phenotype, structure of plasma membrane, and activity of DNA repair system in peripheral blood lymphocytes from patients with different clinical forms of tick-borne encephalitis associated with long persistence of the virus revealed a pronounced imbalance between lymphocyte subpopulations, increased microviscosity of the plasma membrane lipid phase, and decreased activity of the DNA repair system in lymphocytes.
Heterotrophic bacteria were found to be capable of proliferation in physiological saline and distilled water. In 1988-1989 experimental studies were made with a view to establish the role of the gaseous phase of atmospheric air and the products of the autolysis of dead bacteria as the sources of organic nutrition. The studies revealed that the complete removal of atmospheric air from vials with bacterial suspension completely stopped the stimulation of reproduction. In vials with a higher concentration of dead bacterial bodies the proliferation rate was 2- to 400-fold (on the average, 118-fold) higher. The products of the autolysis of bacterial bodies proved to be of no importance as an independent source of organic nutrition for heterotrophic bacteria. The mechanism of the assimilation of autolysis products is "switched on" by biologically active geomagnetic disturbances. The mechanisms of the increase of bacterial biomass remain unclear.
Patients with tick-borne encephalitis (TBE) had higher counts of red blood cells (RBC) with micronuclei. The majority of patients revealed decreased capacity of blood lymphoid cells for DNA repair except those with a 2-wave pattern of the course of disease; in the latter, the DNA repair was significantly higher than in healthy donors. Patients with TBE revealed lower T-lymphocyte counts due to a decrease in the amount of T-helper cells (the level of T-suppressors was elevated). The intensity of antibody production against TBE virus was significantly enhanced by termination of disease in the majority of patients. The count of natural killer cells was decreased, particularly at the initial stage of disease. At the time of admission to hospital the counts of RBC with micronuclei and of T-helper cells were in reverse proportion. At the terminal stage of disease the same correlation was noted between RBC counts with micronuclei and the antibody level. At the onset of disease a direct correlation was noted between DNA repair and B-lymphocyte and T-helper counts. At the final stage of disease the reverse correlation between the activity of DNA-repair systems and T-suppressor counts was registered. Three months after discharge from hospital, the indices of micronuclear test, natural killer cell activity, and DNA repair returned to normal.
Infectious mononucleosis may be differentiated from clinically similar diseases by the detection of classes M and A antibodies to Epstein-Barr virus capsid antigen. The authors emphasize the high specificity of this test vs. the detection of the Paul-Bunnell-Davidson heterophilic antibodies.
The comparative study of disturbances in the immune status of patients with different clinical forms of tick-borne encephalitis has revealed that in the severe (meningeal) form of the disease more pronounced imbalance in the immune system develops, especially with respect to immunoregulatory subpopulations of T-lymphocytes. This seems to be the cause of delayed activation of immune processes in this group of patients in comparison to those having an aborted course of the disease.
Analysis of the structure of immunoregulatory cells (IRC) as the reflection of cell interaction in healthy persons and in patients with typhoid fever, tick-borne encephalitis, or chronic opisthorchiasis has shown that the characteristics under study (information entropy, structural information, the coefficient of ecological-genetic correspondence) are highly sensitive and specific, which makes it possible to use them quite effectively for differentiating health from disease and for identifying this disease. The study of IRC structure as the reflection of cell interrelations helps evaluate the changes in the organization of IRC system as a whole in different infectious diseases.
In 116 patients with opisthorchiasis running a cholecystocholangitic variant of the disease course, the characteristics of nonspecific resistance (complement, lysozyme, properdin), cell-mediated and humoral immunity (T- and B-lymphocytes, T gamma-, T mu-, O-, D-, A-cells and auto-rosette-forming cells, IgG, IgA and IgM) have been studied. Essential changes in these characteristics before and after treatment, as well as at the remote periods of dispensary observation, have been established.
The informative logical analysis has been used as the basis for the construction of the functional models of the immune status in the form of logical formulae. In these models the character of interrelations between immunocompetent cells in health and disease is reflected. Such models make it possible to substantiate the necessity, as well as the differentiated methods, of the correction of disturbances in the immune status, depending on the nature of the pathological case.
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.
A standard, highly specific and sensitive enzyme immunoassay test system has been developed for the diagnosis of acute opisthorchiasis, which is based on indirect solid-phase enzyme immunoassay for determination IgM antibodies to the antigen derived from Opisthorchis felineus marita extracts. The sensitivity of the test system is 87%, its specificity is 96.8%.
Sixty three patients with chronic opisthorchiasis were cytogenetically, serologically, and biochemically studied. Most patients with opisthorchiasis were found to have higher or high titers of antibodies to Epstein-Barr viral antigens. There was a direct correlation between the titers of antibodies to Epstein-Barr virus capsid antigen and the count of cytogenetically damaged cells. The majority of opisthorchiasis patients with superinvasion, hepatic, pancreatic, and oropharyngeal diseases showed a great increase in the titers of antibodies to Epstein-Barr virus antigens and a high persistence and in the cytogenetically damaged lymphocytes. Opisthorchiasis patients with high antibody titers to Epstein-Barr virus capsid antigens showed a considerable decrease in the parameters of the peripheral antioxidative system.
The characteristics of the functional status of peripheral blood monocytes/macrophages in patients with Ixodes tick-borne acute borreliosis accompanied by opisthorchiasis invasion were studied. The study revealed a decrease in the phagocytic activity of monocytes and in the level of expression of cell receptors Fcgamma with the expression of cell receptors C3beta being normal.
The occurrence of chronic tick-borne encephalitis viral antigenemia characterized by the asymptomatic course or minimal clinical manifestations is caused by the virus-immune cell interaction. Cellular immunity was studied in 183 patients with chronic (more than 6-month) tick-borne encephalitis viral antigenemia, by evaluating the immunophenotypic and cytogenetic statuses, structural and functional features, cytokine profile, and peripheral lymphocytic apoptosis. The findings suggest impairments in the cooperation of immunocompetent cells and in the classical scheme of antiviral immunity regulation in tick-borne encephalitis viral persistence due to the changes in lymphocytic structural and functional properties.
The hormonal function of the hypophysis and thyroid (TTG, T3, T4) and its dependence on hepatobiliary function, examined by hepatobiliscintigraphy, were studied by radioimmunoassay in 71 patients with chronic opisthorchiasis and in 18 chronic carriers of Salmonella typhi. in both groups. The decrease of T3 and T4 in the presence of normal TTG level was found. The imbalance of thyroid hormones activity is likely to be associated with hepatobiliary dysfunction. In chronic opisthorchiasis the hormonal disturbance may be one of the factors favouring the S. typhi carriership.