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K L Shakhanina

Publications and source records attributed to K L Shakhanina.

At least 19 recordsLinked to original sources
PubMed1992

[Immunoenzyme analysis of antigen-specific determination of HBsAG-containing circulating immune complexes (CIC HBsAG/IgM and CIC HBsAG/IgG) in blood serum of patients with HBV-infection].

A complex enzyme immunoassay (ELISA) has been designed for antigen-specific determination of HBsAg-containing circulating immune complexes (CIC HBsAg/IgM and CIC HBsAg/IgG) in human blood sera in parallel with registration of free HBsAg and specific antibodies to viruses of hepatitis A, B and D. It is shown that effective formation of HBsAg-containing CIC serologically is registered predominantly as a mutually incompatible marker with detection of free HBsAg (in 70-85% of the cases). CIC HBsAg/IgM and CIC HBsAg/IgG may be registered both in parallel and as mutually exclusive markers. Effective formation of HBsAg-containing CIC in the presence of anti-HBsAg occurs in case of a mild course of viral hepatitis of epidemic and sporadic type, while in severe forms of VH-free HBsAg is predominantly detected thus pointing either to ineffective formation of HBsAg-containing CIC or to their continuous registration with demonstration of the effect of delay of witching of anti-HBsM over to anti-HBsG (or CIC HBsAg/IgM to CIC HBsAg/IgG). It was also found that in case of epidemic VH in Tajik SSR (1987) serologically marked as VH both A and B convalescent phase was characterized by parallel disappearance (or lowering of the titer levels) of HBsAg-containing CIC and class M antibodies to both hepatitis A (anti-HAV M) and B (anti-HBcM, anti-HBsM) along with the containing parallel registration of relevant G-antibodies (anti-HAV G/anti-HBcG). This observation requires further studies both in terms of close association of viruses of hepatitides A and B and with regards to possible antigenic mimicry.

Adult↗
PubMed1991

[Interaction of rabbit IgG with anti-IgG: localization of epitopes and absence of immunoreactivity of the pFc'-fragment].

To localize essential epitopes of rabbit IgG, a series of proteolytic IgG fragments obtained by papain (Fab, Fc) or pepsin (pFc', F(ab')2) proteolysis have been prepared and their interaction with sheep antibodies against rabbit IgG has been studied. The data obtained suggest that essential immunoreactive epitopes of rabbit IgG are located in the CH2 domain and hinge region. This finding is in line with the results obtained by computing the antigenic sites of immunoglobulins. However, the deviation from the computed antigenic structure was deduced from the complete lack of immunoreactivity of the pFc fragment, it being a dimer of the terminal CH3 domain of the Fc fragment. The hinge region comparable in size with the dimensions of the epitope reveals high affinity binding to anti-IgG, thus testifying to the localization of the expressed epitope or its essential part in the hinge region. Proteolytic cleavage of this region leads to a significant decrease in the binding of the IgG fragment to anti-IgG. In addition to the CH2 domain and hinge region, a relatively low interaction of the antigen-binding antibody fragments with anti-IgG was found.

Animals↗
PubMed1989

[The diagnosis of antileptospiral antibodies in human subjects by solid-phase immunoenzyme analysis].

The possibility of using the enzyme-linked immunosorbent assay (ELISA) for the diagnosis of leptospirosis has been shown. This method has proved to be more simple and sensitive than the leptospiral microagglutination and lysis test. The data on obtaining genus-specific leptospiral antigens are presented. As revealed in this study, the antigens obtained by the complex treatment of microbial cells with ultrasound and detergents show the maximum activity in ELISA. The optimum parameters of the ELISA system for the diagnosis of leptospirosis have been established.

Antibodies, Bacterial↗
PubMed1989

[The use of an immunoenzyme method for the rapid diagnosis of legionellosis].

An enzyme immunoassay (EIA) system for the detection of L. pneumophila antigen in clinical material (sputum, urine, bronchial washings) has been developed. The use of EIA permits the detection of L. pneumophila antigen in the urine of 75-80% of patients during the first week of the disease. The specificity and sensitivity of EIA makes it possible to recommend this method for the rapid diagnosis of L. pneumophila infection.

Antibodies, Bacterial↗
PubMed1988

[Use of the ELISA immunoenzyme method for the detection of the causative agent of tularemia].

The conditions of the enzyme-linked immunosorbent assay (ELISA) for the detection of Francisella tularensis were worked out. In the study of 27 strains differing in their biological characteristics, the sensitivity of the assay was determined, varying within the range of 1 X 10(4)--5 X 10(4) million cells/ml and exceeding the sensitivity of the currently used methods for the immunodiagnosis of tularemia by 1-2 orders. ELISA also proved to be a highly effective technique for the detection of the specific antigen in the organs of infected animals. The antigen was regularly detected in the organs of white mice, beginning from day 3 after their infection with the minimal doses of F. tularensis. The method may be recommended both for the identification of isolated cultures and for the early diagnosis of tularemia infection.

Animals↗
PubMed1988

[Immunoenzyme analysis for determining class G and M antibodies to HBsAg].

A scheme of the purification of hepatitis B virus surface antigen (HBsAg) as applied to the enzyme immunoassay (EIA) for the detection of antibodies to HBsAg is described. An indirect EIA technique for the detection of IgG and IgM antibodies to HBsAg has been developed and the diagnostic assay system based on the use of immunoreagents and solid-phase carriers produced in the USSR has been obtained. The sensitivity of the indirect EIA technique in the detection of IgG antibodies to HBsAg exceeds that of double immunodiffusion in gel used for this purpose 2,500- to 5,000-fold. The study has shown the possibility of using the indirect EIA technique for the detection of antibodies to HBsAg, both free and bound in immune complexes, of detecting antibodies to HBsAg in patients with acute and chronic viral hepatitis B, as well as of simultaneous detection of IgG and IgM antibodies to HBsAg without pseudonegative results.

Blood Donors↗
PubMed1987

[Detection of the antigens of the causative agent of brucellosis by an immunoenzyme method].

The conditions of the enzyme immunoassay for the detection of Brucella antigens have been selected, making it possible to detect these antigens both in solutions and in biological material within 3-4 hours. In guinea pigs infected with B. abortus 99 in a dose of 1,000 microbial cells, brucellar antigen has been detectable in the organs and blood serum of the animals as early as 24 hours after infection. This assay, if carried out under the optimal conditions, detects soluble brucellar polysaccharide antigen at a concentration of 1 ng/ml and Brucellae at a concentration of 5 X 10(4) microbial cells/ml in the presence of 200-fold surplus of other bacterial cells.

Animals↗
PubMed1987

[Importance of the determination of antibodies to n-DNA in systemic lupus erythematosus and other rheumatic diseases (comparative study of radioisotope and immunoenzyme technics)].

Altogether 95 patients with systemic lupus erythematosus, 36 patients with rheumatoid arthritis, 10 with sclerodermia systematic, 10 with Bekhterev's disease, 9 with rheumatic fever, and 20 healthy persons were examined. An analysis of the results made it possible to establish that in SLE, sclerodermia systematic and Bekhterev's disease the frequency of detection of higher levels of antibodies to n-DNA using enzyme immunoassay and radionuclide methods was approximately the same. SLE patients were characterized by a 2-fold increase in the level of antibodies to n-DNA as compared to patients with sclerodermia systematic, Bekhterev's disease and rheumatic fever suggesting usefulness for differentiation of these diseases. In rheumatic fever and rheumatoid arthritis antibodies to n-DNA in minimal elevated levels were revealed more frequently under enzyme immunoassay than in radionuclide ones. In SLE high levels of antibodies to n-DNA under the method of radionuclide binding showed significant correlation with a decrease in complement hemolytic activity, high levels of circulating immune complexes, with a higher frequency of detection of the antinuclear factor, and reflected lupus nephritis severity. Enzyme immunoassay used for the detection of antibodies to n-DNA showed correlation of high levels of these antibodies with signs of developing cerebrovasculitis and pulmonary lesion.

Adolescent↗
PubMed1987

[Choice of the suitability criteria of polystyrene-based solid-phase carriers for performing immunoenzyme analyses].

The authors discuss a tentative approach to the choice of criteria indicating the optimal suitability of different solid-phase carriers made of polystyrene for use in the enzyme immunoassay (EIA), viz. the dependence of specificity, sensitivity, reproducibility and reliability of EIA results on the adsorption properties, transparency expressed in percent and transparency variations of the plates under test. The evaluation of the carriers by four parameters is proposed with the use of assay plates manufactured by Nunc A/S (Denmark) for control. To ensure the objective evaluation of the suitability of polystyrene plates for use in EIA, the choice of uniform criteria is necessary.

Adsorption↗
PubMed1986

[Development of an immunoenzyme method for detecting Francisella tularensis].

The conditions permitting the determination of F. tularesis cells by means of the enzyme immunoassay (EIA) in 3-5 hours have been established. Ways for enhancing the reliability of results obtained in the assay of the least possible amount of the test material have been proposed. The sensitivity and specificity of the rapid EIA technique permitting the determination of F. tularensis cells at a concentration of 20 000 cells/ml in the presence of other bacterial cells in 100-fold excess have been shown.

Antibodies, Bacterial↗
PubMed1985

[Differential affinity of pathogenic species of microorganisms for a set of lectins detectable by the sandwich method using fluorescein isothiocyanate (FITC)].

The qualitative differences in the affinity of concanavalin A (Con A), wheat-germ agglutinin (WGA) and Phaseolus vulgaris lectin to the surface of 10 microbial strains inducing various diseases in humans and agricultural animals have been demonstrated by means of the indirect immunofluorescence tests. Enterobacteria, Coxiella burnetii and Bacillus anthracis have been found to possess pronounced affinity to Con A and WGA, while Rickettsia prowazekii, Francisella tularensis and Brucella abortus, as well as Treponema pallidum, have proved to be resistant to lectins. WGA has been found to bind specifically to Brucella abortus and Treponema pallidum. Con A and WGA are seemingly suitable for use in the preliminary test for the total capacity of lectin receptors to come in contact with biological macromolecules.

Animals↗
PubMed1984

[Receptors for lactoferrin on human thymic lymphocytes. The stimulation of expression as affected by adenosine, theophylline and a supernatant of thymic lymphocytes].

It was established by indirect immunofluorescence with the use of antibodies to human lactoferrin that thymic lymphocytes bear lactoferrin receptors in the point structures on the cell surface. The ability of thymic lymphocytes to express lactoferrin receptors depends on the cAMP concentration in the cell, inasmuch the treatment of lymphocytes with adenosine and theophylline increases the number of cells bearing lactoferrin receptors. Supernatant of thymic lymphocytes is also capable of stimulating expression of lactoferrin receptors. It is assumed that these treatments can be used for increasing the number of lymphocytes with lactoferrin receptors with the purpose of separation and study of the function of this subpopulation in health and in different pathological conditions.

Adenosine↗
PubMed1984

[Determination of tularemia antibodies by an immunoenzyme method on a solid-phase carrier (ELISA)].

ELISA "sandwich" techniques have been developed and the optimum assay conditions for detecting specific antibodies in human serum samples have been determined. The possibility of using these techniques for the determination of the level of antibodies to tularemia antigens in the sera of persons immunized with live tularemia vaccine has been shown. Statistically significant differences in the level of antibodies to tularemia antigen in the sera of immunized and nonimmunized persons have been established. The comparative study of five serological methods - ELISA, the agglutination test, the passive hemagglutination test, the immunofluorescence test and the defined antigen substrate sera ( DASS ) techniques - has revealed the advantage of ELISA, whose sensitivity has proved to be considerably higher than that of all other methods used in our work.

Agglutination Tests↗
PubMed1984

[Use of an immunoenzyme method on a solid-phase carrier for determining the tularemia antigen].

The method of the highly sensitive (up to 10 ng/ml) and specific determination of soluble tularemia antigen, based on the use of "sandwich" type ELISA techniques, has been developed. The dependence of the specificity and sensitivity of the method on the degree of purification of antibodies and their peroxidase conjugates used in the assay has been studied. The study has revealed that the best results can be obtained with the use of purified IgG and its conjugate free of unbound peroxidase. Both foreign peroxidase preparations and type A enzyme manufactured in the USSR can be equally used as enzymatic labels.

Antigens, Bacterial↗