Search

We studied immunogenicity of two recombinant proteins FR.9 and FR.11-3 created on the basis of fragments of the primary structure of N. meningitidis IgA1 protease with different molecular weights containing different sets of T and B epitopes. The proteins actively protect animals infected with live virulent culture of meningococci, serogroups A, B, and C. Analysis of CD4+, CD8+, and CD19+ lymphocyte populations in mouse blood showed predominant contribution of different cell populations to the formation of immune response to different proteins. Injection of FR.11-3 protein to animals did no affect the immunoregulatory index, hence, this protein can be used for creation of immunologically safe vaccine preparation.

Using the genome sequence of IgA1 protease of N. meningitidis of serogroup B, four recombinant proteins of different structure and molecular weight were constructed. These proteins were equal in inducing the formation of specific antibodies to IgA1 protease and had protective properties against meningococci. In the sera of immunized mice, anti-IgA1 protease antibodies were detected by whole-cell ELISA, which indicated the presence of IgA1 protease on the surface of these bacteria. We hypothesized that the protective properties of IgA1 protease-based antigens and IgA1 protease analogs could be realized not only via impairment of bacterium adhesion to the mucosa, but also via suppression of this pathogen in the organism. The presented findings seem promising for using these proteins as the basis for anti-meningococcus vaccine.

It was experimentally demonstrated that cholinesterase activity increases in the gray matter of the cerebral hemispheres in tetanus and dysentery intoxications. However, there is no change in its activity in pneumococcal mococcal intoxication. The activity of the enzyme does not change in the cerebellum in tetanus and dysentery intoxications. The increase in activity of cholinesterase in all the above cases is proved statiscally.

The authors study the effect of compound B 58, a synthetic interferon inducer, on activity of natural killer cells (NKC) and cytostatic effectors in the mouse spleen. NKC activity in the spleen was determined in the 4-hour microtoxicity test against VAC-1 target cells labeled with /sup 51/Cr. /sup 3/H-thymidine was added to the effectors and targets. An increase in activity of the cellular mechanisms of natural antitumor resistance arising under the influence of compound B 58 is shown.

The average percentage of spontaneous plasmid-negative variants in an initial resistant population of staphylococci developingin vitro was 0.9±0.2 in broth and 1.2±0.3 in exudate; developingin vivo, in a subcutaneous suppurative inflammatory focus it was 6.3±2.0 and in the kidneys 9.5±2.6. The average percentage of spontaneous plasmid-negative variants in purulent exudatein vivo was significantly higher than in purulent exudatein vitro. The frequency of appearance of these variantsin vivo depends on the properties of the host.

The degree of the inhibiting concentration of isoniazid, kanamycin ethionamide, ethambutol and D,L-cycloserine with regard toM. tuberculosis var. avium increases with a decrease in the oxygen content of the medium. The inhibiting concentration of D-cycloserine does not depend on the oxygen content of the medium. The bactericidal effect of isoniazid on tuberculosis mycobacteria grows with an increase in the aeration of the medium and slows down with its decline. An analogous relationship in a somewhat lesser degree was revealed in experiments with D,L- and D-cycloserine and was manifest slightly, if at all, in experiments with ethionamide, ethambutol and kanamycin.