[Polymorphism of tox and dtxR genes in circulating strains of Corynebacterium diphtheriae].

Polymorphism of tox and dtxR genes responsible for diphtheria toxin synthesis was revealed. Seven point mutations in tox gene were detected; study of their combinations allowed to determine 10 allelic variants of the tox gene in C. diphtheriae strains.

[Molecular typing of the strains of Bordetella pertussis circulating in St. Petersburg during an outbreak of the disease].

Growth of the whooping-cough morbidity during the last years in Russia and other countries with 40-year-long history of immunization gave rise to significant interest of researchers to variability of the Bordetella pertussis population. Comparative assay of the genomes of the B. pertussis strains circulating in St.

[The adhesive properties of meningococci from serogroups A, B and C].

The adhesive properties of 261 meningococcal strains have been studied by the methods of the hemagglutination test, the test of adhesion on buccal epithelial cells and electron microscopy. The study has revealed that adhesive properties can be observed in the strains of all groups under study (A, B and C) isolated from patients and carriers, including those isolated from the nasopharynx, blood and liquor, adhesive properties occurring in newly isolated strains with greater frequency than in museum ones. The simultaneous use of all three above-mentioned methods increases the possibility of the detection of meningococcal strains with adhesive activity.

Coenzyme non-specific glutamate dehydrogenase from Chlorella pyrenoidosa 82T: electron microscopic studies.

The constitutive coenzyme non-specific glutamate dehydrogenase (GDH) from Chlorella pyrenoidosa 82T was purified to homogeneity by column immunoaffinity chromatography and examined by an electron microscope. The enzyme molecule was found to be a hexameric oligomer composed of monomers arranged in three 2-point group symmetry in two layers slightly twisted round the 3-fold axis. The molecule is 8 +/- 1 nm in diameter and 10 +/- 1 nm in height.

[Current aspects of the short-term prognosis of meningococcal infection morbidity for the sake of epidemiological surveillance].

The short-term prognosis of the epidemic situation requires the establishment of the system of constant surveillance, which takes into account the data on morbidity rates for several years, both total and in various age groups, the data on the morbidity level and its changes, induced by meningococci of the epidemic group, in the IV quarter of the year, the data on the level of carriership among the indicator groups of the population in this period, as well as the data on changes in antibody titers in the sera of donor blood samples taken in summer and in December.

[Effect of testosterone, its 5 alpha-reduced metabolites, estradiol and progesterone on the formation of an experimental duodenal ulcer in male rats].

The influence of different doses (0.01, 0.1, 1.

[Characteristics of free water distribution in the cytoplasm of cryotolerant cells of Cryptococcus laurentii].

The resistance to freezing-thawing was studied with Cryptococcus laurentii cultivated at a near-zero plus temperatures in a minimal or a rich medium. At the transition into the stationary phase, the resistance of the cells to freezing increased 20 times in the culture grown in the minimal medium and 8 times in the culture grown in the rich medium. Free water localization in the cell cytoplasm was determined by electron microscopy.

[Structural role of histidine residues in NAD(P)-glutamate dehydrogenase from the bovine liver].

Photooxidation of bovine liver glutamate dehydrogenase (GDH, EC 1.4.1.

[Dependence on androgen metabolism in the hypophysis and hypothalamus on age in rats].

The in vitro metabolism of 3H-testosterone, 3H-dihydrotestosterone, 3H-5 alpha-androstan-3 alpha, 17 beta-diol and 3H-5 alpha-androstan-3 beta, 17 beta-diol was studied in hypophyses and hypothalamuses of the rats at the age from 5 to 60 days. The androgen metabolites were separated by means of chromatography in thin layers of silicogel. The rate of androgen metabolism in the organs studied from the 5th till the 23rd day of development was dozens of times that in the adult animals.

In vitro metabolism of androgens in hypothalamus and pituitary from infantile and adolescent rats of both sexes.

The metabolism of [3H]testosterone, [3H]dihydrotestosterone and [3H]. 5alpha-androstan-3beta, 17beta-diol was studied in vitro in pituitaries and hypothalami of male and female rats aged 5, 10, 15, 23, 30, 40 and 60 days. The concentration of labelled androgens in incubation medium was 10-20 nmol l-1.

[Role of 5-alpha-androstane-3-beta, 17-beta-diol in establishing feedback between the gonads and hypothalamo-hypophyseal system of orchidectomized adult rats].

Concentration of luteinizing hormone and content of luliberine were estimated, respectively, blood serum and in hypothalamic arccuate nucleus and median eminence of adult castrated rats after administration of testosterone, 5 alpha-androstane 3 beta, 17 beta diol and 5 alpha-androstane 3 alpha, 17 beta diol. Effect of testosterone and of its derivatives on hypothalamo-hypophysial system was distinctly dissimilar both in the intensity of the action and in the rate of its realization. 5 alpha-androstane 3 beta, 17 beta diol as well as testosterone and 5 alpha-androstane 3 alpha, 17 beta diol were shown to be active in the negative feedback mechanism between gonads and hypothalamo-hypophysial system; the effect of androgenes was dose-dependent.

[Changes in the concentration of luteinizing hormone in the blood serum and of luliberin in the hypothalamus of castrated rats after the administration of testosterone and its 5 alpha-reduced metabolites. I].

Luteinizing hormone concentration in the blood serum and luliberin content in the hypothalamic arcuate body and medial eminence were determined in castrated mature rats 1, 3, 6, 12, 24 hours afte single injections of testosterone and its 5 alpha-reduced metabolites (dihydrotestosterone, 5 alpha-androstane-3 alpha, 17 beta-diol and 5 alpha-androstane-3 beta, 17 beta-diol) at a dose of 2.5 x 10(-7) kg/kg body weight by radioimmunoassay. Principal differences between testosterone and its 5 alpha-reduced metabolite action on the hypothalamohypophyseal system were detected from the stand point of their effectiveness and the effect realization rate.

[Metabolism of sex steroid hormones in neuroendocrine organs. I. In vitro androgen metabolism in the hypophyses and epiphyses of rats during the puberal period].

Metabolism of tritium-labeled testosterone, delta4-androstane-3, 17-dion, dihydrotestosterone. 5alpha-androstane-3alpha, 17beta-diod and 5alpha-androstane-3beta, 17beta-dion by the isolated hypophyses and epiphyses of male and female 30-day rats was studied. The glands were incubated in Eagle's medium containing the mentioned androgens with the concentration of 1-2.