[Comparative pathomorphological assessment of the action of Vibrio cholerae serogroups 01 and 0139]. / Eksperimental'nye dannye sravnitel'noi patomorfologicheskoi otsenki deistviia kholernykh vibrionov 01 i 0139 serogrupp]

The pathomorphological picture of experimental infection caused by the infective agent of cholera was shown to have some specific features observed in infections caused by vibrios belonging to the serogroups under study. Infection caused by V. cholerae of serogroup O139 induced some morphological changes in the gastrointestinal tract which were quite characteristic of this disease, but inflammatory changes with the prevalence of proliferative infiltrative processes came to the foreground simultaneously with less developed processes of edema and dystrophic lesions of enterocytes. These specific morphological features in animals infected with V. cholerae of serogroup O139 appeared to be probably due to the production of new surface structures by these strains.

[Apudocytes in experimental cholera vaccination]. / Sostoianie apudotsitov pri protivokholernoi vaktsinatsii.

The morphofunctional state of apudocytes in the gastrointestinal tract and immunocompetent organs (spleen, mesenteric lymph nodes) of mice immunized with chemical bivalent cholera vaccine was studied. The study revealed that the APUD system of the intestine and the argyrophil elements of the immunocompetent organs of white mice gave a response to the oral administration of commercial cholera vaccine. The reaction of the APUD system of the gastrointestinal tract was manifested by a significant increase in the number of apudocytes and their greater synthesizing activity in the immunized animals during the period of maximum immunological transformation of the macroorganism. The immunization of mice with Vibrio cholerae facilitated the maintenance of homeostasis in the macroorganism and prevented appearance of morphological disturbances in its organs and system after subsequent challenge with V. cholerae.

[The APUD-system function of the intestines and the morphological changes in the internal organs of adult rabbits infected with toxigenic Vibrio cholerae]. / Sostoianie APUD-sistemy kishechnika i morfologicheskie izmeneniia vo vnutrennikh organakh vzroslykh krolikov, zarazhennykh toksigennymi kholernymi vibrionami.

V. cholerae infection with clearly pronounced diarrhea was reproduced in adult rabbits with the use of the RITARD system. The state of the APUD system of the intestine of the animals and morphological changes in internal organs in experimental cholera were described. As noted in this study, the manifestation of changes in the intestine and other organs, as well as the reaction of apudocytes to V. cholerae infection, were linked with the intensity of diarrhea and the time of the death of the animals.

[The comparative characteristics of the pathogenic action of Vibrio cholerae of the non-O1 group O139 serovar and of the O1 group on the intestinal APUD system of suckling rabbits]. / Sravnitel'naia kharakteristika patogennogo deistviia kholernykh vibrionov ne O1 gruppy O139 serovara i O1 gruppy na APUD-sistemu kishechnika krol'chat-sosunkov.

The comparative study of the enteropathogenic action of V. cholerae strains of group non-O1, serovar O139, and group O1 with different virulence on the APUD system of the intestine of suckling rabbits after intraenteral infection revealed that V. cholerae of group non-O1 induced inflammatory changes in the intestine and the pronounced toxic lesion of parenchymal organs. This was accompanied by a decrease in the number of apudocytes and an increase in the functional tension of the APUD system. After the infection of the animals with V. cholerae of group O1 changes in the APUD system and internal organs directly depended on the virulence of the microbes and the infective dose.

[The effect of choleragen poisoning on the intestinal apudocytes of gnotobiotic minipigs]. / Vliianie kholerogennoi intoksikatsii na apudotsity kishechnika gnotobioticheskikh mini-porosiat.

Intragastric administration of the cholera toxin to gnotobiotic mini-pigs results in cyclic morphofunctional alterations of intestinal apudocytes followed by their degranulation, a decrease in their number from 1 to 3 hrs and after 18 hrs, while a slight increase in their number occurred from 3 to 12 hrs. The response of APUD-system cells is similar in large and small intestine. Products of apudocyte secretion may be involved in the diarrheogenic effect of the cholera toxin.

Dermatonecrotic lesions in rabbits caused by neuraminidase.

In an attempt to study the role of neuraminidase in cholera vibrio pathogenesis, the dermatonecrotic effect of a purified neuraminidase preparation was studied in rabbits. The experiments demonstrated that dermatonecrotic lesions resulted from intracutaneous injection of a purified neuraminidase preparation (0.5 specific human dose or 1 NU) as well as significant doses of cholera toxoid containing the enzyme (4,12,18 specific human doses).

[An experimental study of the safety of a chemical monovalent tableted cholera vaccine in enteral administration]. / Eksperimental'noe izuchenie bezvrednosti kholernoi khimicheskoi monovalentnoi tabletirovannoi vaktsiny pri énteral'nom vvedenii.

The safety of experimental chemical cholera monovalent vaccine in tablets, produced by the institute "Microbe" (Saratov, USSR), has been studied. The study has shown that the vaccine, administered to adult rabbits and germ-free suckling rabbits by the enteral route, retains residual toxicity, mainly due to the presence of O-antigen. One or two administrations of 1-2 human doses of this preparation to adult rabbits induce minimal structural changes admissible from the viewpoint of safety. After immunization made in two administrations immunobiological transformation develops more rapidly and is more pronounced than after immunization in a single administration.

[The effect of different Yersinia pestis antigens on the cellular link in immunity]. / Izuchenie vliianiia razlichnykh antigenov Yersinia pestis na kletochnoe zveno immuniteta.

Immunization with live plague vaccine has been shown to give no protection to thymectomized mice from subcutaneous challenge with Y. pestis virulent strain. Under the action of the vaccine or individual Y. pestis antigens (fraction I) the functional and morphological activation of thymocytes and macrophages is observed, more pronounced in C57BL/6 mice and less pronounced in CBA mice. Y. pestis antigenic preparations (fractions I and II, pesticin) act as T-cell mitogens and are thus capable of inducing the in vitro proliferation of thymocytes. At the same time the in vivo action of fraction II induces a decrease in the level of lymphocytes in the peripheral blood of mice and the destruction of lymphocytes in their thymus and spleen.

[Morphological changes caused by the dermonecrosis factor of the causative agents of cholera and various other intestinal infections]. / Morfologicheskie izmeneniia vyzvannye dermonekroticheskim faktorom vozbuditelei kholery i nekotorykh drugikh kishechnykh infektsii.

Intra- or subepithelial focal purulent inflammation with necrosis of exudating leucocytes during 1-2 days is developed in consequence of intradermal injection of the living cholera vibrios, cultured on membrane agar, or their supernatants. Sometimes coagulative necrosis of cover epithelium arises without preliminary purulent inflammation stage from the very beginning. Intradermal injection of living cholera vibrios leads to the development of coagulative necrotic foci in derma too. The vascular genesis of alterations mentioned above is supposed.

[The role of T-suppressors in the formation of plague immunity in mice]. / Rol' T-supressorov v formirovanii protivochumnogo immuniteta u myshei.

Antiplague immunization of mice causes an increase in the number of T-suppressors in their thymus and spleen; this increase is especially pronounced after injection of a low-immunogenic dose of the vaccine strain. T-suppressors specific to Yersinia pestis antigens were detected in the thymus on day 3 after a single injection and on day 14 after two injections of the vaccine strain.

[The potentiating action of artificial immunodeficiency on the development of amyloidosis in plague in great gerbils]. / Potentsiruiushchee deistvie iskusstvennogo immunodefitsita na razvitie amiloidoza pri chume u bol'shikh peschanok.

Cyclophosphamide injection causes amyloidosis development in the spleen of great gerbils both intact and plague-infected after immunization. The amyloid deposits are observed irrespective of acquired antiplague resistance level. Alterations observed may be considered as acquired (secondary) AA-amyloidosis. Results indicate the significance of immunodepression in amyloidogenesis and a possibility to use the cyclophosphamide-treated great gerbils as a convenient experimental model of amyloidosis.

[Use of gnotobiotic animals for the study of the pathogenesis of cholera intoxication]. / Ispol'zovanie gnotobioticheskikh zhivotnykh dlia izucheniia patogeneza kholernoi intoksikatsii.

Germ-free suckling rabbits and minipigs can be recommended as models suitable for the study of different aspects of the pathogenesis of cholera intoxication. In minipigs, individual representatives of intestinal autochthonous microflora produce different effect on the sensitivity of the animals to the toxigenic and choleragenic action of Vibrio cholerae antigen introduced by oral administration, that should also be taken into consideration in the determination of residual toxicity during the trial of new vaccine preparations against cholera.

[Morphological study of the damaging effect of an EB vaccine strain of the plague microbe in inbred mice]. / Morfologicheskoe izuchenie povrezhdaiushchego deistviia vaktsinnogo shtamma EB chumnogo mikroba u inbrednykh myshei.

The data obtained during the study of the morphological changes in the internal organs and blood of 6 mouse strains at the early stages of anti-plague immunity are presented. It has been established that the introduction of 5.10(3) and 1.10(5) m. b. of the EV vaccine strain resulted in the development of morphological changes typical of residual virulence. The degree of these changes depended on the haplotype of the animals and the dose used. The most resistant to injury induced by EV strain were CBA mice (haplotype H-2k) and the most sensitive were C57BL/6 mice (haplotype H-2b).

[Effect of intestinal microflora on the pathogenesis of cholera intoxication]. / Vliianie mikroflory kishechnika na patogenez kholernoi intoksikatsii.

Germ-free minipigs, previously treated with bacteroids, develop cholinergic reaction after the intragastric administration of Vibrio cholerae exotoxin. The intensity of this reaction, disturbances in homeostasis, and the character of morphological changes depend on the dose of choleragen, the bacteroid strain, and the presence of the concomitant (Escherichia coli) and residual microflora in the intestine.