[Isolation and study of influenza A viruses in different cell cultures]. / Vydelenie i izuchenie virusov grippa A na raznykh kletochnykh kul'turakh.

The usefulness of some cells cultures (BSC-I, VERO, MDSK) for isolation and study of reproduction of influenza A viruses was explored. Out of 50 clinical specimens examined, in 16 cases the virus was isolated both in chick embryos and in MDSK cell cultures. MDSK cultures were found to be highly sensitive to influenza A viruses, which produced cytopathic effect and hemagglutinin accumulation. The plaques formed by freshly isolated strains under an agar overlay containing trypsin were markedly polymorphous. MDSK cells may be recommended for use in virus isolation studies. Examinations of virion morphology revealed their diversity both in size and shape.

[Electron microscopic and immunological study of influenza virus interaction with murine peritoneal microphages]. / Elektronno-mikroskopicheskoe i immunologicheskoe izuchenie vazaimodeistviia virusa grippa s peritoneal'nymi myshinymi mikrofagami.

Electron microscopic and immunological investigations of influenza virus HONI interactions with peritoneal macrophages of intact and immune mice were carried out. Both intact and immune macrophages exert phagocytosis and disintegration of virions in phagolysosomes as early as 10 and 30 min after the end of adsorption. This process is most active with eosinophils, less in neutrophils and the least in basophils. Titration of the infectious virus in chick embryos showed that immune macrophages contained considerably less virus than the intact ones.

[Electron microscopic study of the interaction of Yersinia pseudotuberculosis with macrophages and HeLa cells]. / Elektronno-mikroskopicheskoe izuchenie vzaimodeistviia Yersinia pseudotuberculosis s makrofagami i kletkami HeLa.

The comparative electron-microscopic study of early stages of the interaction of Y. pseudotuberculosis virulent strain (No. 282) with "professional" (macrophages) and "nonprofessional" (HeLa cells) phagocytes has been carried out. The character of the intimate mechanism of this interaction has been found to be essentially different. The common feature for both systems is the adsorption of bacteria and their penetration into cells due to phagocytosis. But the subsequent fate of Y. pseudotuberculosis is different. In HeLa cells they are isolated from the cytoplasm by multilayer membrane structures, thus remaining morphologically intact. In macrophages the destruction of the microbe in phagolysosomes occurs.

[Surface structure of the elementary bodies of Chlamydia]. / Stroenie poverkhnosti élementarnykh telets khlamidii.

The surface structure of chlamydial elementary bodies (strain PL-B577 causing enzootic abortion of ewes and strain CP-1 isolated from a patient with Reiter's syndrome), concentrated directly on the grid of an electron microscope, was studied by the method of negative staining. The surface of the cell wall of chlamydial elementary bodies in the preparations of crude cultures, not subjected to enzymatic purification, was formed by spherical subunits 4 nm in diameter. The surface of the cell wall of elementary bodies was found to have projections 10-20 nm long and 3-4 nm in diameter, as well as annular structures 15-22 nm in diameter in hexagonal arrangement, spaced at 45 nm and probably traversed by these projections. The number of such structures in a group was 12-15. These data correspond to the model representing the structure of the surface of chlamydiae, which was proposed by Matsumoto in 1979.

[Electron microscopic study of the interrelation of the L forms of beta-hemolytic Streptococcus group A with mouse peritoneal macrophages]. / Elektronno-mikroskopicheskoe izuchenie vzaimootnoshenii L-form beta-gemoliticheskogo streptokokka gruppy A s peritoneal'nymi makrofagami myshei.

Interrelations between the L-forms of group A beta-hemolytic streptococci and mouse peritoneal macrophages have been studied by electron microscopy. The macrophages have been shown to actively phagocytize L-form cells in great amounts. Most of the phagocytized L-forms are destroyed and become nonviable, but a few of them survive as elementary bodies within 48 hours.

[Electron microscopic study of the interaction of virulent and avirulent Shigella flexneri strains with the macrophages of murine peritoneal exudate]. / Elektronno-mikroskopicheskoe izuchenie vzaimodeistviia virulentnogo i avirulentnogo shtammov Shigella flexneri s makrofagami peritoneal'nogo ékssudata myshei.

The electron microscopic dynamic study of the interaction of S. flexneri virulent strain 2a and S. flexneri avirulent strain, genetically related to strain 2a and having the same antigenic structure, with peritoneal macrophages of CBA mice at an early period showed differences in the cytotoxic action of these strains. Even at the early period of the interaction between macrophages and virulent shigellae structural changes were observed in macrophages: ruptures in the membranes of parasitophore phagosomes, the vacuolization of the cytoplasm, the destruction of mitochondria. These changes were indicative of the early cytotoxic action of shigellae belonging to the virulent strain. In macrophages infected with avirulent shigellae the manifestations of this cytotoxicity were less pronounced and appeared later than in macrophages infected with S. flexneri virulent strain.

[Antigenic structure of Salmonella L forms studied by an immunoferritin method]. / Izuchenie antigennoi struktury L-form sal'monell s pomoshch'iu immunoferritinovogo metoda.

The antigenic structure of the L-forms of salmonellae (S. typhimurium and S. typhi) in comparison with that of the initial bacterial cultures and revertant cultures was studied with the use of the immunoferritin method. The L-forms of salmonellae were found to retain an insignificant amount of O-antigen, as well as to have K-antigen on the surface of the cytoplasmic membrane, but in a lesser amount than the initial strains. In the cultures reverting from the L-forms of S. typhimurium and S. typhi the quantitative and qualitative characteristics of O- and K-antigens were completely restored.

The morphology and nucleotide composition of DNA of Citrobacter phages.

Citrobacter phages 38/37, 31/37, 40/1 and 8/5, isolated from lysogenic cultures, were concentrated and purified by 2 cycles of differential centrifugation. Electron microscopy of the phages has shown that their particles have similar morphology and that they relate to the morphological group A1. The heads of the phages are hexagonal, 50 +/- 2 nm in diameter. The tail of the phage is straight, 112-152 nm in length, with a contracting sheath 11.5-12.5 nm wide. The tails of the phages 38/37 and 40/1 were found to be slightly longer in comparison with the phages 31/37 and 8/5. Chromatographic investigation of DNA preparations of the phages revealed the presence of 4 nitrous bases. Identification of the latter permitted us to relate them to common nitrous bases. DNA of the phages is double-stranded and belongs to a weakly expressed guanine-cytosine type. The content of guanine and cytosine in DNA of the phage 38/37 amounts to 56.68%, that of the phage 31/37 to 56.75, of the phage 40/1 to 57.36% and of the phage 8/5 to 55.58%. No substantial variations were observed in the DNA composition of the phages.

[The relationship between the fate of the agent of toxoplasmosis, Toxoplasma gondii, in macrophages cultivated in vitro and the virulence of the parasites]. / Sud'ba vozbuditel'ia toksoplazmoza Toxoplasma gondii v makrofagakh, kul'tiviruemykh in vitro, v zavisimosti ot virulentnosti parazitov

Comparative light microscopic and electron microscopic studies of development of a highly-virulent RH strain and a less virulent Lagrave strain of Toxoplasma cultivated in macrophages in vitro were made. Contrary to active multiplication of the highly virulent strain most of toxoplasmas of a less virulent strain disintegrated the first hours, degenerating completely in 24-48 hours after the penetration into the macrophages. Submicroscopic study showed no marked cytological changes of macrophages infected with a less virulent strain in comparison with the marked changes of the nuclei in macrophages infected with the RH strain. Disintegration of parasites within the phagosome was accompanied by a gradual transformation of an originally double (or triple) vacuolar membrane to a single membrane and by the disappearance of an additional layer of mitochondria and endoplasmic reticulum elements surrounding the vacuolar membrane. It is likely that the capacity of toxoplasma to develop in macrophages in vitro could become an additional marker to its virulence for albino mice.