PubMed Health⌕ Search

Biomedical subjects

K A Lebedev

Publications and source records attributed to K A Lebedev.

At least 37 records · Page 2Linked to original sources
PubMed1984

[Interrelations in the immune system of Staphylococcus aureus carriers].

The immune status of 60 S. aureus carriers and 60 donors without carrier state was studied with respect to the interrelations of their antistaphylococcal immunity characteristics and natural resistance factors with the levels of different parameters. In contrast to the donors without carrier state, new interrelations between specific and nonspecific humoral immunity factors were shown to appear in S. aureus carriers, their blood sera having the elevated levels of bactericidal activity and the increased titers of staphylococcal antibodies. The phagocytic activity of the blood in the carriers proved to be below the normal level. The S. aureus carriers were found to have disturbances in the interrelations of their phagocytic activity and specific humoral immunity. The immune status of the carriers as characterized by the interrelations of its parameters is compared with the immune status of normal persons.

Adolescent↗
PubMed1983

[Interrelation of the immunological parameters of healthy donors and of persons frequently ill with acute respiratory diseases and bronchitis in the remission stage (a new approach to assessing immune status)].

The state of the immune system in healthy donors and in chronic bronchitis patients, frequently suffering from acute respiratory diseases, at the period of remission has been studied by the methods of rosette-formation and phagocytosis. The authors propose a new approach to the evaluation of the immune system by regarding each of these groups as a dynamic set of discrete values. As a result, the parameters of the immune system have proved to be interrelated. These interrelations, in contrast to the variability of the numerical values of different parameters, remain constant in health persons and are seemingly the basis of the stability of their internal medium, or at any rate of their immune system. At the same time under the conditions of the remission of chronic bronchitis the interrelation of the above-mentioned parameters has altered in comparison with the normal state, which makes it possible to characterize the immune status of these patients as the state of imbalance of the immune system.

Acute Disease↗
PubMed1983

[Immunogenicity characteristics of a microorganism population from the pathological foci in chronic inflammatory diseases of the upper respiratory tracts].

The staphylococcal population isolated from the pathologic focus in patients with chronic infectious inflammatory diseases of the upper respiratory tract has been found to be heterogeneous in immune response it induces in the body. The action of immune serum in vivo and in vitro leads rather quickly to quantitative changes in the surface antigenic structures of microbial cells, disappearing in the absence of contact with antibodies. The data obtained in this study indicate that the immunogenicity of microbes easily changes under the influence of immune response, which permits them to evade the immunologic control. It is quite probable that such processes play an essential role in the formation of chronic inflammatory diseases.

Animals↗
PubMed1981

[Inhibiting effect of phenformin (phenethyl biguanide) on the growth of Ehrlich carcinoma].

Phenformin was shown to inhibit the rate of the Ehrlich carcinoma cell growth both in solid and ascitic forms of the tumor. The effect of phenformin on the tumor was eliminated by a diet containing high level of fats. The supernatant from the 18-hour culture of splenic cells, obtained from carcinoma-bearing mice treated by phenformin, inhibited phagocytosis of normal macrophages to a less extent compared with tumor-bearing mice which were not given phenformin. A peritoneal exudate from these mice was less effective in suppressing normal macrophages adhesiveness compared with untreated tumor-bearing mice.

Animals↗
PubMed1981

[Heterogeneity of agglutinability and antibiotic sensitivity of a population of Staphylococcus aureus isolated from tonsillar lacunae of patients with angina and chronic tonsillitis].

The study of the staphylococcal microflora of the tonsils in chronic tonsillitis patients revealed a high degree of variability in respect to its sensitivity to different antibiotics and the level of its agglutination by blood serum. The lesser part of the patients showed the presence of staphylococcal clones agglutinated by highly diluted serum and resistant to antibiotics suppressing the main part of the microbial population. The appearance of such clones in the microbial population is supposed to be the reason for the development of antibiotic-resistant population.

Agglutination↗
PubMed1981

[Changes in the proliferative activity of L cells in response to immune sera].

The influence of heterologous anti-L-serum and IgG isolated from it on the proliferative activity of L cells was studied with the use of the 3H-thymidine incorporation technique. High concentrations of the antiserum were shown to suppress, while low concentrations to stimulate the proliferative response of L cells. Both high and low concentrations of IgG were found to stimulate L cells. This indicates that stimulation of the growth of L cells is caused by antibody fraction. The presence of a greater number of antibodies, as well as of some serum components, is required for the development of the inhibitory effect. The line of the effect may be changed by supplementary actions. The proliferative activity of the whole population of L cells and descending cells was evaluated from the total 3H-thymidine incorporation.

Animals↗
PubMed1980

[Study of peripheral blood T-lymphocytes by the spontaneous and active "rosette" method using levamisole].

To study a possible relationship between the content variability of immunocompetent cells of peripheral blood and changes in their physiological activity, 43 healthy subjects were examined by means of the spontaneous and active rosette-formation tests with the use of levamisol. The evidence obtained suggest that variation in the number of spontaneous and active rosette-forming cells are consequent on changes in the physiological properties of these cells, depending on the functional state of the body.

Adolescent↗
PubMed1980

[Inhibitory effect of serum on the phagocytic activity of macrophages in vitro].

The effect of blood sera obtained from sick and healthy persons on the phagocytic activity of mouse macrophages has been studied by means of in vitro tests. The study was made on blood serum samples taken from patients with diseases owing their pathogenesis largely to the role of macrophages, such as hemoblastosis (acute leukosis, myeloleukemia, erythremia), cancer of the larynx, parasitic diseases (acute and chronic opisthorchiasis, schistosomiasis). These patients were found to have humoral factors suppressing the phagocytic activity of mouse macrophages in vitro accumulated in their blood. The test allowing to evaluate the level of humoral antimacrophage suppressants has been developed. The formation of these mediators is supposed to occur in the spleen, as the suppressant action of blood serum disappears after splenectomy.

Adult↗
PubMed1980

[Antibodies to staphylococcal autostrains in polypoid tissue of the human nasal mucosa].

The immune response of the body to different clones of nasal staphylococcal population in polypous rhinosinusitis has been studied. The titers of antibodies to different staphylococcal clones were shown to differ considerably. The titers of antibodies to different clones in polypous tissue were found to be higher or lower than the respective titers in the general blood stream. Thus different immunologic conditions for the development of microorganisms could locally appear in the presence of intensive general immune reaction. This seems to be due to differences in the intensity of the production of antibodies to these microorganisms in the lymphoid tissue of the nasal mucosa.

Adult↗