Isolation of Actinomycetes synthesizing proteases with thrombolytic activity

Proteases with the thrombolytic activity were studied in 212 strains of actinomycetes isolated from different soils of the Soviet Union. The cultures belonged to the genera Micromonospora, Nocardia and Streptomyces. Proteases were synthesized by 41% of the studied actinomycetes and some of their strains completely dissolved in vitro artificially obtained blood thrombi within 120-240 min. In the Streptomyces genus, more active strains were found in the groups Flavus, Fradia and Globisporus. The groups Olivaceus, Violaceus and Viridis had less active strains.     

Fat absorption following temporary ischemia of the small intestine

Ischemia of the rat small intestine lasting 40 min leads to pronounced structural disorders in lipid transport across the enterocytes, reduction in enzymatic activity of the cells and in absorption function, and to the loss of fat with feces. The normalization of the indicated parameters occurs at varying times and ends after 1 month. Fat transport abnormality is marked by an increase in lipid drops in the cavities of the smooth endoplasmic network, appearance of large and numerous matrix lipids, by a greater reduction, as compared to normal, in the membranes of the rough endoplasmic network and lamellar complex in the epithelium of the villi. Accumulation of lipids and retardation of their release from the cytoplasm are determined by incomplete differentiation of the epithelium, which is also combined with a decreased enzymatic activity.     

The development of the epidemic process and the formation of humoral immunity to the hepatitis A virus in adolescent collectives

Additional observation on the formation of humoral immunity to hepatitis A virus has been carried out in 2,375 adolescents aged 15-17 years and belonging to 12 groups at 3 areas of the USSR. This observation has shown that in the presence of a high level of the immune stratum the spread of infection occurs, as a rule, outside the group under observation. Besides, as revealed in this study, the risk of seroconversion and the loss of specific antibodies are, respectively, directly and inversely related to the level of the immune stratum in the group. The level of the immune stratum in a given age group supposedly reflects the intensity of the development of the epidemic process at a definite area.     

Immunomodulating effect of levamisole in antibiotic therapy

The use of ampicillin, benzylpenicillin, gentamicin, erythromycin, cefamezine or cephaloridine in combination with levamisole aimed at increasing their efficacy and correcting the adverse reactions was studied. Immunological activity of the antibiotics was comparatively characterized by using standard methods. It was shown that the character of the antibiotic effect on the basic factors of nonspecific resistance and immunity was heterogeneous. Schemes for using the antibiotics in combination with levamisole for correcting the detected disorders in the immunity status of the experimental animals were developed.     

Comparison of different methods of introducing a label into the DNA of microorganisms

Different methods of isotope introduction into plasmid and chromosomal DNA have been compared. The efficiency of label introduction into DNA was estimated by the results of DNA--DNA hybridisation and by the thermostability of hybrid duplexes. Using the enzymatic methods of label introduction levels of DNA specific radioactivity and label binding in homologous and heterologous reactions were close. DNA labeled by the method of enzymatic methylation forms more thermostable hybrid duplexes than "nick-translation" DNA. The advantages of enzymatic methods of label introduction for creating a microorganism reference DNA bank are discussed.     

The microflora of synanthropic flies in Czechoslovakia

Folia Microbiologica -     

Morphometric and electron microscopic study of the small intestine following total orthotopical auto- and allotransplantation]

Total orthotopic autotransplantation of the small intestine was performed in 22 dogs, allotransplantation--in 13 dogs. Changes in the wall of the graft resulted from the effect of both nonspecific (ischaemia, blockage of lymph outflow, denervation) and specific factors connected with the reaction of tissue incompatibility. Changes caused by the nonspecific factors are demonstrated as lymphostasis, edema of the wall in the graft, atrophy of the villi with epithelial flattening, hyperplasy of the intestinal gland, macrophagal and plasmocytic reaction in the mucous lamina propria, drop in villous-cryptic coefficient and reduction of the absorbing surface of the villi. At autotransplantation, structural-functional changes in the intestine undergo three stages: the stage of acute morphological changes and pronounced functional disturbances (up to 1,5 months); the stage of relative structural stabilization and gradual functional restoration (up to 6 months); the stage of atrophic-hyperplastic changes in the wall and decrease in functional activity of the intestinal graft (followed-up for 15 months). At allotransplantation, depending on the degree of cellular reaction and vascular changes, as well as on the localization of the process in the wall of the graft, a "graft versus host" reaction and a "recipient versus graft" reaction is demonstrated. Peculiar rosettes of plasmocytes have been described as a possible index of the reaction "graft versus host".     

Effect of Lincocin Treatment on the Greening Process in Bean (Phaseolus vulgaris) Leaves

The effect of lincocin (a plastid protein synthesis inhibitor) treatment on the greening process of bean (Phaseolus vulgaris L.) leaves have been studied. In comparison with control leaves treated ones had a decreased rate of chloroplast development. They had a marked chlorophyll deficiency and a decreased chlorophyll a/b ratio. Some long and short wavelength forms of chlorophyll a were lacking as evidenced from the absorption spectra at 25°C and the fluorescence spectra at 77°K. The –¹⁴CO₂ fixation was inhibited by 80–90% in treated leaves. The fluorescence induced by the measuring light was greater in the treated leaves than in the control ones, and the kinetics of the decline of the relative fluorescence intensity were also different. Electron microscopic studies showed macrogranum-like structures and incomplete membrane vesicles in the treated plastids. After longer treatment a destruction of membranes was observed. The results indicate some structural and functional membrane deficiencies and instability of the membranes.