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Biomedical subjects

N G Orlova

Publications and source records attributed to N G Orlova.

At least 19 recordsLinked to original sources
PubMed1999

[Optimization of a method of solid-phase immunoenzyme analysis for determination of chloramphenicol in milk].

The method of solid-phase enzyme linked immunosorbent assay (ELISA) for quantitative detection of chloramphenicol (CAP) in milk was developed. Peculiarities of the adsorption on the microtitre plates surface of CAP-ovalbumin conjugate were investigated. Different conditions of competition stage of the analysis were studied. Conditions providing CAP monitoring in human blood serum in the clinical range were optimized. Matrix effect on the assay results was studied. The specificity of the analytical system was investigated and the reagents stability was examined. The method developed permits CAP concentration to be determined in human blood serum, diluted 1/100, in the linear range from 0.1 to 100 ng/ml. The assay is characterized by high sensitivity (0.08 ng/ml) and good reproducibility (CV < 10.8%), assay time is about 3 hours. The correlation coefficient with HPLC is 0.977.

Animals↗
PubMed1992

[The effect of the bronchoalveolar fluid of mice infected with the influenza virus on hematopoietic bone marrow precursors].

The influence of bronchoalveolar washing fluid (BAWF), as well as BAWF cells, obtained from mice infected with influenza virus, on the formation of exogenic spleen colony-forming units (CFUs) of lethally irradiated syngeneic recipients was studied. BAWF and BAWF cells of intact syngeneic mice stimulated the growth of CFUs. BAWF of mice infected with nonpathogenic strain A/PR/8/34 lost its capacity for stimulating the growth of colonies, and BAWF cells greatly suppressed colony formation in the spleen of recipients. The participation of interferon, colony-stimulating factor and the virus itself in the process of the modulation of colony formation is discussed.

5'-Nucleotidase↗
PubMed1991

Correlation of amino acid residues in the M1 and M2 proteins of influenza virus with high yielding properties.

The ability of influenza A viruses to replicate to high titer in the allantoic sac of the chicken embryo has been mapped to the matrix protein gene (RNA 7). Because influenza A/WSN/33 (H1N1) virus grows poorly in this host but contains a matrix protein gene with a sequence similar to sequences from viruses that grow well in eggs, we derived a single gene reassortant containing only the M gene from A/WSN/33 (H1N1) in a background of the other 7 RNA segments from A/Philippines/2/82 (H3N2) (a low yielding virus, hy-). This reassortant replicated 10 times better than the A/WSN parent itself, indicating that the high yielding (hy+) phenotype of the A/WSN/33 M gene may be suppressed by one of the other genes of A/WSN/33. Comparison of M gene sequences between hy+ (including A/WSN/33) and hy- strains allowed us to correlate specific amino acid positions in M1 and M2 proteins with the growth properties of influenza viruses.

Amino Acid Sequence↗
PubMed1991

[The immunomodulating action of the surface antigens of the influenza A virus in experimental staphylococcal infection].

The results of the study of influenza A virus surface antigens, hemagglutinin and neuraminidase, in the induction of nonspecific immunomodulation and protection from acute pulmonary staphylococcal infection have been studied. Protective effect, the cell composition of bronchoalveolar lavage fluid depend on the serological subtypes of surface antigens used for intranasal immunization and the infective dose of staphylococci.

Animals↗
PubMed1990

[The role of food hypersensitivity in the pathogenesis of protracted forms of intestinal infections in infants].

Sensitization with food antigens and the status of the general and local immunological systems were examined in 31 children suffering from lingering intestinal infections which may be related to body sensitization with food antigens. The children of the first year of live manifested sensitization to cow's milk proteins most frequently, particularly to alpha-lactablumin and beta-lactoglobulin. The main criteria for laboratory diagnosis of food sensitization were blood eosinophilia, the presence of eosinophils in the feces, the presence of antibodies to food antigens, blood hypo- and dysimmunoglobulinemia. The treatment of lingering intestinal infections requires the use of etiotropic drug therapy, hypoallergenic dietetic management bearing in mind individual food intolerance, and the use of antihistaminic drugs.

Chronic Disease↗
PubMed1989

[The role of cellular and humoral factors of body resistance in the development of experimental influenza-staphylococcal infections in mice].

The clinico-experimental studies of mixed influenza-staphylococcal infection constantly point to the development of the aggravation of the infectious process due to the synergic action of the bacterial and viral infective agents. But, as shown by the authors of the present work, in those cases when the experimental infection with the virus was preceded by staphylococcal infection by 72 hours no synergism was observed. In cases of infection with adaptogenic virus the mortality rate of mice resulting from meningococcal infection was twice as low. The possible explanation of this fact is discussed.

Animals↗
PubMed1987

Microecology and local immune and nonspecific defensive proteins depending on different nutrition.

Breast-feeding is of high importance for the development of intestinal eubiosis. Before beginning with breast-feeding the coprofiltrates of newborns lack of IgA. Following the first feeding IgA concentration in the faeces sharply increases (up to 200 mg/100 g faeces). Comparable high values can be found in the coprofiltrates of breast-fed sick prematures. In the coprofiltrates of artificially fed healthy newborns and sick prematures no IgA is provable, within the first two weeks of age. Afterwards both the frequency of its evidence and its concentration gradually rise. This can be regarded as a sign of an increasing local production of immune proteins. Starting with the second year of life, only, the values of all the immunoglobulins fall again. It happens a microbial degradation. Increased concentrations of immunoglobulins in the coprofiltrates of children over 3 years must be evaluated as a sign of subclinical dysbacteriosis.

Digestion↗
PubMed1984

Microecology of the gastrointestinal tract and the immunological status under food allergy.

In children suffering from food allergy the microecology of the gut and the immune status were examined. As a rule, sensitization due to the penetration of the epithelial barrier of the intestinum by macromolecules of the food is not accompanied by deficiency of secretory IgA. In all cases dysbacteriosis of different degree was observed with a characteristic picture of deficiency of Bifidobacteria and Lactobacilli combined with rising numbers of Enterobacteriaceae. Correlations to an altered immune response are obvious.

Antibodies↗
PubMed1977

Infectivity of DNA recovered from cells persistently infected with SV5 paramyxovirus.

Infectivity of DNA isolated from L cells chronically infected with SV5 paramyxovirus was demonstrated by inoculation of continuous RH and HEp-2 cells. Infectivity of the DNA was completely abolished by treatment with deoxyribonuclease or by alkaline hydrolysis but did not change after treatment with ribonuclease and specific anti SV5 serum. The virus obtained as a result of transfection caused haemadsorption in susceptible cells and was neutralized by specific antiserum like the prototype SV5 strain.

Animals↗
PubMed1975

Neuraminidase activity of influenza virus-infected cells: localization and properties.

Infection of chick embryo cell (CEC) cultures with influenza virus results in the appearance of neuraminidase activity lost by the cells as a result of cultivation. Neuraminidase activity is associated mainly with the lysomal cell fraction. Different distribution of neuraminidase activity in lysosomes with various densities, different reaction to sodium ethylene diamine tetracetate (EDTA) and differenct optimal pH suggest that at early stages of viral infection the cell enzyme is activated and by the 7th hour of infection viral neuraminidase is synthesized.

Acid Phosphatase↗