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Biomedical subjects

Iu N Kovalev

Publications and source records attributed to Iu N Kovalev.

At least 19 recordsLinked to original sources
PubMed2000

[Development of a quantitative PCR variant, and use of it for assessing gene expression].

The data on the development of a quantitative PCR technique are presented, including the synthesis of modified primers, the choice of conditions for the removal of reaction-mixture components from the amplified DNA, and the colorimetric detection of the PCR product. The application of this technique to the assessment of the level of gene expression in nonculturable bacterial forms characterized by a drastically reduced metabolism is described.

Colorimetry↗
PubMed2000

[Use of molecular-biological methods for identifying brucella in a comparative analysis of strains, isolated from sick dogs].

Ten strains isolated from sick dogs in 1998 in St. Petersburg were studied by traditional and molecular biological methods of Brucella identification. PCR study confirmed that the isolated cultures were Brucellae, and comparative study of the traditional phenotypical characteristics and protein and antigenic composition allowed referring all the isolated strains to B. canis. Traditional identification showed similarity of 7 strains with the reference B. canis strain RM6/66, and 3 strains were similar to B. canis Mex 51 strain. These results confirmed the division of B. canis into two biovars. Polyacrylamide gel electrophoresis with sodium dodecyl sulfate demonstrated the identity of protein profiles of 10 strains isolated from dogs to the reference B. canis RM6/66 strain. Immunoblotting analysis with S- and R-specific rabbit antisera also demonstrated the identity of antigens binding IgG antibodies in the strains isolated from dogs to the reference B. canis RM6/66 strain.

Animals↗
PubMed1994

[Electrokinetic potential of Yersinia pestis and Escherichia coli cells with an intact or defective ycaA gene (caf1M) of the fra-operon of plague pathogen].

The dependence of the amount of electrokinetic potential in cells of Escherichia coli and Yersinia pestis, which differ in the rate of reduction of lipopolysaccharide (LPS), on the presence or absence of typical and atypical capsules of Y. pestis, encoded by intact and mutant fra operons, respectively, was studied. The ycaA+ycaF+(caf1 M+caf1+) genotype was shown to be expressed in serological stability of a classical capsular antigen, irrespective of the producer strain, and a decrease in the negative charge of microbial cells compared to their noncapsular variants. Blocking of the synthesis of the product of the ycaA gene of the fra operon resulted in formation of encapsulated bacteria, whose surface electricity and serological characters varied in dependence on the LPS structure. Data obtained support the assumption that a product of the ycA gene stabilizes the conformation of the typical capsule of the plague-causing agent, which was formed from YcaF (Caf1) monomers.

Escherichia coli↗
PubMed1991

[The chrysotherapy of patients with Reiter's disease].

Chrisanol therapy was provided to 172 men suffering from Reiter's disease, having histocompatibility antigen B35 and its combination with B27 as well as B17 and B11 indicating that the articular syndrome may run a persistent and grave course. Chrisanol therapy brought about a decrease of the activity of complement, lysozyme, bactericidal activity of blood serum, a reduction of the content of serum IgG, and autoimmune reactions parameters. Chrisanol therapy was tolerated well. The ten-year follow-up revealed relapses in 8.3% of the patients.

Adolescent↗
PubMed1990

[The characteristics of the immune response to Chlamydia antigens in patients with Reiter's disease].

Immunologic tests (complement fixation, microprecipitation reaction, leukocytic agglomeration phenomenon, leukocyte migration inhibition tests) with standard chlamydial antigen were used in examinations of 116 male patients with Reiter's disease, 54 of these with the first (early) and 62 with the second (late) stages of this process. The findings evidence a higher intensity of antichlamydial humoral and cellular immune response in the patients with the first stage of the disease and a much lower intensity of those with the second stage. The pathologic process in patients with the second stage is liable to a prolonged self-maintaining course and is torpid to anti-infection therapy, as against that in the patients with the first stage of the condition; this fact prompts a conclusion that such a course of the process is explained not so much by the infectious agent, as by immune inflammation.

Antibodies, Bacterial↗
PubMed1989

[The urogenital inflammatory focus and its treatment in Reiter's disease].

The complement fixation test, microprecipitation, leukocyte migration inhibition, leukocyte agglomeration phenomenon, direct and indirect immunofluorescence were used to demonstrate that chronic prostatovesiculitis associated with Reiter's disease may be of immune-induced nature. This requires a differentiated approach to the choice of the treatment policy. The methods of the treatment for the urogenital inflammatory focus in men suffering from Reiter's disease are provided. It is indicated that complete cure of Reiter's disease can be attained only after elimination of inflammation in the urogenital organs.

Antibodies↗
PubMed1989

[A diagnostic criterion of Reiter's disease].

Clinical and laboratory criteria of the diagnosis of Reiter's disease are presented, based on many-year clinical and immunologic examinations of 254 male patients with this condition; these criteria help early and reliably diagnose this disease.

Arthritis, Reactive↗
PubMed1981

[Transducing lambda phages with Escherichia coli genes].

The paper presents data on transducing lambdoid phages containing Escherichia coli genes. The major genetic techniques for isolating transducing phages (in vivo) are outlined. A combined table of best-studied transducing phages obtained by the methods of molecular genetics and genetic engineering lists phages genotype & basic literature references for the phages and their derivatives. The chromosome fragments of E. coli inserted in phage DNA are separately specified. Another table presents information about phages carrying E. coli fused operons and genes. The paper also provides detailed physical maps of three regions of the E. coli chromosome. The bibliography contains 300 items.

Bacteriophage lambda↗
PubMed1979

[New transducing phage with RNA polymerase beta- and beta'-subunit genes derived from a hybrid phage lambda att80: isolation, genetic analysis and physical mapping].

A hybrid lambda att 80 phage with the genetic structure lambda (A-J) phi 80 (att-int-xis) imm lambda..cI857s7 is shown to be a convenient vector for creating transducing phages. On the one hand, the restriction analysis indicates that it has 3 restriction sites for EcoRI in comparison with 5 and 9 sites for parental phages lambda and phi 80 respectively. On the other hand, its buoyant density is less than that of phage lambda and under centrifugation it is easier separated from the phage transducing particles. When lambda att 80 prophage was excluded from the bfe locus of Escherichia coli, transducing phages with genes of two RNA polymerase beta-subunits (rpoB and rpoC) were isolated. To identify the latter, a convenient genetic test was worked out. A physical map of lambda att 80 drifd 35 transducing phage, carrying rpoB and rpoC genes has been constructed using endonucleases EcoRI and HindIII. A comparison of this map and the corresponding maps of transducing phages lambda drifd 18 and lambda drifd 47, studied earlier, led to the discovery of two integration sites of phage lambda within the locus bfe spaced apart by about 1800 nucleotide pairs. At all the sites both phages (lambda and lambda att 80) have integrated in the locus bfe in the counter clockwise order.

Bacteriophage lambda↗