[Experimental morphological study of the therapeutic effect of shark cartilage preparation in a model of infective allergic arthritis].

The therapeutic effect of a Polar shark cartilage preparation which is an enzymatic hydrolysate was studied in a rabbit model of infective allergic pseudotuberculous arthritis. Characterization of the chemical composition of the preparation designed by an original method is presented. Improvement of the general state of the affected joints and development of tissue immunomorphological responses were shown.

[Influence of temperature on the variability of Listeria monocytogenes in the course of its prolonged existence in soil-packed water-circulating columns]. / Vliianie temperatury na izmenchivost' Listeria monocytogenes pri dlitel'nom obitanii v protochnykh pochvennykh kolonkakh.

The capacity of L. monocytogenes for prolonged existence in the soil at different temperatures (18-20 degrees C and 6-8 degrees C) has been shown. The viability of these bacteria in the soil depends both on their properties and the temperature factor. Low temperatures (6-8 degrees C) ensure, on the whole, the stable preservation of the biological properties of the bacteria. More pronounced variability of L. monocytogenes at a temperature of 18-20 degrees C is an adaptive property, ensuring high ecological plasticity of the bacteria and their prolonged existence in the soil.

[Mechanism of viral infection of macrophages by an agent of hemorrhagic fever with renal syndrome: ultrastructural aspects]. / Mekhanizm infitsirovaniia makrofagov vozbuditelem gemorragicheskoi likhoradki s pochechnym sindromom: ul'trastrukturnye aspekty.

Monocytes/macrophages are one of the first cells subjected to the infectious effect of viruses. The present paper analyses for the first time the ultrastructural changes in macrophages caused by an agent of hemorrhagic fever with renal syndrome (HERS)--hantavirus (HV). After a local fusion with the host cell plasmalemma and its adsorption on the cell surface, the HV penetrates through the macrophage membrane. This process occurred without destruction of cell plasmalemma. HV viral particles were observe within the macrophage cytoplasm mostly on the smooth granular endoplasmic reticulum vesicles. Viroplasts were defined in macrophages after a 2 h incubation, with synthesis of viral nucleoproteins and primary covers being observed on the surface of viroplasts. Viral particles left macrophages in the process of budding on the phagocyte surface. Thereby HV, similar to other enveloped viruses, realizes entrance and egress from the target cell without damaging its plasmalemma. This accounts for the viral ability to reproduce in macrophages for a long time without any cytopathological effect. Consequently, in the absence of obvious destruction changes, mononuclear phagocytes can serve as a long-term storage of viruses, and thus being involved in HV dissemination during HERS.

Cardiopathy modeling in rats.

Stages of reproduction of a polyetiological model of coronary failure in rats are described. The model is based on the development of electrolyte steroid cardiopathy. Morphological studies confirmed the presence of degenerative changes in rat myocardium and coronary vessels. The model is intended for studies of the development and remission of cardiac diseases.

[Experimental tick-borne encephalitis in golden hamsters treated with specific immunotherapy]. / Eksperimental'nyi kleshchevoii éntsefalit u zolotistykh khomyachkov na fone spetsificheskoi immunoterapii.

Efficiency of various protocols of specific immunoglobulin treatment was evaluated in golden hamsters inoculated with two Far Eastern tick-borne encephalitis (TBE) strains. After a low therapeutic dose (0.1 ml) of immunoglobulin, corresponding to total dose (60 ml) per course, all parameters (survival, immunogenicity, pathomorphology of the brain) deteriorated in animals infected with both strains. A higher dose (0.2 ml) corresponding to total dose of 120 ml notably improved all the studied parameters. The efficiency of specific immunoglobulin depends on the clinical and pathogenetic characteristics of TBE, determined by the properties of TBE strains. The results validate therapy and prevention of TBE by high-titer immunoglobulin in adequate total dose, monitored by blood analyses for TBE antigen and evaluations of the time course of IgM antibodies.

Ultrastructure of Yersinia pseudotuberculosis inhabiting the soil for a long time.

Ultrastructural changes in the population of pathogenic Yersinia pseudotuberculosis inhabiting a model soil ecosystem for a long time were studied. Changes in the bacteria were mainly adaptive until the 8th month of the experiment, their capacity to binary division was preserved. After 9 months cell structure changed: extracellular amorphous matrix appeared, probably due to increased mucus production.

Pathomorphological characteristics of experimental toxemia induced by thermostable Yersinia pseudotuberculosis toxin.

Pathogenic properties of thermostable toxin responsible for pathogenicity of Yersinia pseudotuberculosis were experimentally studied. The toxin exerted a pronounced polyorgan cytopathogenic effect with predominating degenerative destructive changes and membranolytic effect on cell ultrastructure of parenchymatous organs. The toxin is believed to be directly involved in the development of typical pathomorphological picture of pseudotuberculosis, which confirms its pathogenetic role.

Genetic diversities of hantaviruses among rodents in Hokkaido, Japan and Far East Russia.

Seroepizootiologic surveys among wild rodents were carried out in Japan and Far East Russia in 1995 and 1996. Seropositive animals were only identified in Clethrionomys rufocanus (23/134) in Hokkaido, Japan. On the other hand, seropositives were identified in C. rufocanus (1/8), Apodemus agrarius (2/66), Apodemus spp. (2/26) and Microtus fortis (3/22) in Vladivostok, Far East Russia. Total RNA was isolated from lungs of seropositive animals and the S genome segments were amplified by PCR, cloned and sequenced. The S and M genomes of hantavirus, derived from Japanese C. rufocanus (Tobetsu genotype), were most closely related with Puumala viruses (76-79% nucleotide and 95% amino acid identities for S genome, 70-78% nucleotide and 87-92% amino acid identities for M genome). The recombinant nucleocapsid protein of Tobetsu genotype was antigenically quite similar with that of Sotkamo. These suggest that the virus endemic in Japanese C. rufocanus belongs to Puumala virus. Phylogenetic analysis indicates that the genotype forms a distinct lineage within Puumala viruses. Partial S segment (1-1251 nt), derived from seropositive M. fortis in Vladivostok, was sequenced and analyzed. The S genome segment, which was designated Vladivostok genotype, was most closely related with Khabarovsk virus (79% nucleotide and 90% amino acid identities) which was isolated from M. fortis.

[Pathogenetic criteria for evaluating the virulence of tick-borne encephalitis strains isolated in the southern part of the Far East]. / Patogeneticheskie kriterii otsenki virulentnosti shtammov virusa kleshchevogo éntsefalita, izolirovannykh na iuge dal'nego vostoka.

A comparative virological, immunological, and pathohistological study of 5 tick-borne encephalitis (TBE) strains differing by virulence was carried out in golden hamsters. The authors characterize the TBE virus pathogenicity sign, denoted as Pmaic genetic marker (pathogenicity for hamsters at intracerebral inoculation), which helps understand the essence of immunopathogenetic mechanisms of the TBE infectious process in man.

[Morphology of granulomatous inflammation in pseudotuberculosis]. / Morfologiia granulematoznogo vospaleniia pri pseudotuberkuleze.

The study of pathology in pseudotuberculosis has showed that clinical and morphological nature of the disease is related to granulomatous inflammation in organs and tissues. The authors have established that a relapsing course of this infection may be due to pronounced specific sensitization of the body when granulomas appear in large numbers. Morphogenesis of acute granulomatous inflammation in pseudotuberculosis reflects a consecutive involvement of cellular reactions of the immediate and delayed hypersensitivity. In the authors' opinion pseudotuberculosis granulomas may be assigned to immune hypersensitive granulomas of mixed type according to the classification suggested by A. I. Strukov and O. Ya. Kaufman. The data obtained allow a hypothesis that granulomas tending to cause a purulent liquefaction and necrosis, like pseudo-tuberculous granulomas, could be considered as a morphological sign of granulocytic-macrophagal immune deficiency.

[Yersinia L-transformation in experimental pseudotuberculosis]. / L-transformatsiia iersinii pri éksperimental'nom psevdotuberkuleze.

An experiment on guinea pigs infected with virulent Y. pseudotuberculosis has revealed for the first time that in the host body Yersinia cells undergo ultrastructural changes, characteristic of L-transformation. These changes are manifested by damages in the cell wall and peptidoglycan layer of bacteria, dramatic expansion of the peri-plasmatic space, appearance of spheroplast bacterial cells. Myelin-like structures are formed around dead bacteria. These changes reveal one of the possible mechanisms which may render Yersinia harmless in convalescent patients, as well as contribute to the development of relapses of Y. pseudotuberculosis infection.

[Effect of mytilane, a bioglycan from the mussel Crenomytilus grayanus, on the course and outcome of experimental flu infection]. / Vliianie mitilana--bioglikana iz midii Crenomytilus grayanus na techenie i iskhod éksperimental'noi grippoznoi infektsii.

Materials characterizing the antiviral activity of Mytilane, manifested by the protection of 50-60% of mice infected with the lethal dose of influenza virus and by a decrease in the severity of pathological changes in the lungs of mice, are presented. The inhibiting activity of Mytilane with respect to the reproduction of influenza virus in vivo and in vitro under experimental conditions is demonstrated.

[Secondary immunodeficiency in Pseudotuberculosis in man and in experiment]. / Vtorichnyi immunodefitsit pri psevdotuberkuleze u cheloveka i v éksperimente.

Surgical material from 55 children, from 2 to 15 years of age with an abdominal form of pseudotuberculosis (appendix, lymph nodes, ileum) and the immunogenesis organs (lymphoid tissue of the small intestine, lymph nodes, appendix, spleen and thymus) of 277 rabbits infected with virulent strains of the Yersinia pseudotuberculosis I serovar at the dose of 10(8) bacterial bodies were investigated. The results testify to the disturbance of all parts of the immuno-phagocytic system in pseudotuberculosis with the development in some cases of secondary immunodeficiency due to the specific damage of the lymphoid tissue and the functional deficiency of phagocytes. This probably results from the cytotoxicity of the pathogenic factor inhibiting the host defense mechanisms. The tendency to pseudotuberculosis exacerbation and recurrence is associated with the development of the immunodeficiency.

[The biological action of Yersinia pseudotuberculosis endotoxin]. / K voprosu o biologicheskom deistvii éndotoksina Yersinia pseudotuberculosis.

Experimental studies on guinea pigs have shown that Y. pseudotuberculosis lipopolysaccharide is capable of inducing endotoxinemia accompanied by the development of the thrombohemorrhagic syndrome. In cases of pseudotuberculosis the importance of the increased synthesis of prostaglandins and cyclic nucleotides with the prevalence of PGF2 alpha and cGMP in the genesis of toxico-allergic manifestations of pathologic processes has been established. The pathomorphological picture of pseudotuberculosis endotoxinemia is characterized by sludge, the vascular thrombosis of the microcirculatory bed, diapedetic hemorrhages, delymphatization of the immunogenetic organs. The moderately pronounced action of indomethacin, a prostaglandin inhibitor, on the manifestations of pseudotuberculosis endotoxinemia has been revealed.

[The basic features of the pathogenesis of pseudotuberculosis (yersiniosis)]. / Osnovnye cherty patogeneza psevdotuberkuleza (iersinioza).

A new pathogenetic pattern of pseudotuberculosis has been derived on the basis of original clinical, anatomical and experimental findings as well as literature data. Careful consideration is given to: a basic mode of infection (alimentary), emergence of the primary affection with a rapid blood invasion by the agent (primary bacteremia), development of specific sensitization, multiorgan secondary focal impairment with lymphogenic dissemination of the infective agent (specific pseudotuberculous polyadenitis), formation of secondary immunodeficiency, consequent repeat bacteremias, recurrences, symptoms of infectious process aggravations, immunological rearrangement with dominating delayed hypersensitivity. As a rule, the disease terminated by elimination of the secondary foci and recovery.

[Changes in the functional activity of polymorphonuclear leukocytes in pseudotubercular infection]. / Izmenenie funktsional'noi aktivnosti polimorfno-iadernykh leikotsito pri psevdotuberkuleznoi infektsii.

The functional activity of polymorphonuclear leukocytes (PNL) of the peripheral blood of rabbits infected orally with Y. pseudotuberculosis was studied. By day 5 of Y. pseudotuberculosis infection the pronounced stimulation of the myeloperoxidase system with the appearance of respiratory explosion was registered with the use of the nitro blue tetrazolium (NBT) test. The NBT-positive leukocyte index was found to increase 3.32-fold in comparison with the initial data. According to the results of the liposomal cationic test, the stimulation of the system of nonenzymatic cationic PNL proteins was revealed. By day 12 after infection the median cytochemical coefficient reached 2.035 +/- 0.005 conventional units, while in intact animals it was equal to 0.995 +/- 0.002 units. By day 20 a repeated, not so great, increase in the amount of NBT-positive PNL and in the content of cationic proteins in them was observed. The data thus obtained are indicative of the faintly pronounced secretory degranulation of PNL, which was probably one of the causes responsible for disturbances in the process of the digestion of Y. pseudotuberculosis by leukocytes, while their capacity for ingestion was retained.