[Development of specific technics for the prevention of mycoplasma infections in swine]. / K razrabotke metodov spetsificheskoi profilaktiki mikoplazmoza svinei.

Four experimental series were run in 2 experiments with 44 unweaned piglets to test non-inactivated vaccine from ts-mutant M-60 of Mycoplasma (M.) arginini and from attenuated strains of CH-2 M. hyorhinis, EP-29 M. hyosynoviae, M. suipneumoniae, and B-1 Acholeplasma laidlawii. Similar deviations of clinical and immunological parameters were recorded from piglets inoculated with the above vaccine and infected with pathogenic mycoplasma cultures. These deviations, however, were less strongly pronounced in animals which had been inoculated. Mycoplasma species were re-isolated from bronchial lymph nodes and lungs of 62.5% of inoculated piglets. Lasting residual virulence was recorded from the attenuated mycoplasma strains. That residual virulence had no substantial impact upon growth and development of the piglets under laboratory conditions, throughout the period of observation. The above results are likely to suggest the advisability of further studies for the development of a vaccine from ts-mutants and attenuated strains of pathogens of mycoplasmosis in swine.

[Thymus-dependent nature of the antigens of enteropathogenic viruses]. / Timus-zavisimaia priroda antigenov énteropatogennykh virusov.

The nature of antigens in enteropathogenic animal viruses--coronavirus--an agent of transmissive gastroenteritis of pigs (TGE) and pig enterovirus of serotype VI was studied. Basing on the results of the histomorphometric study of the white spleen pulp under the individual introduction of viruses and in combination with the lymphoid chalone it was established that the developing immune response has a thymus-dependent induction mechanism. The pharmacological stimulation of the T-system of animals suffering from virus gastroenteritis provides a positive therapeutic effect. The selective stimulation of the animal T-system may be considered as a promising trend in therapy of intestinal infections and as one of the possible ways to increase the immune response to the antigens of viral vaccines.

Acyclic analogs of nucleosides. Synthesis and in vitro antiviral activity of hydroxyalkyl-2-(trifluoromethylthiomethyl) benzimidazoles.

In a search for novel antiviral compounds of the 'doubly modified' nucleoside type, we have prepared 1-(4-hydroxy-2-oxabutyl)-, 1-(4-hydroxy-3-hydroxymethyl-2-oxabutyl)-, 1-(4-hydroxy-1-hydroxymethy1-2-oxabutyl)-, 1-(4-hydroxy-1-methyl-2-oxabutyl), 1-(4,5-dihydroxy-2-oxapentyl)-, 1-(5-hydroxy-2-oxapentyl), 1-(5-hydroxy-1-chloromethyl-2-oxapentyl)-, and 1-(6-hydroxy-1-chloromethyl-2-oxahexyl)-2-(trifluoromethylthiomethyl)benzimidazole. They were obtained by condensing the trimethylsilyl derivative of 2-(trifluoromethylthiomethyl) benzimidazole with alkylating agents in the presence of an equimolar mixture of trifluoromethanesulfonic acid and trimethylchlorosilane. These nucleoside analogs showed moderate antiviral activity against some RNA viruses.

Acyclic analogs of nucleosides. Synthesis of hydroxyalkyl derivatives of 2-trifluoromethyl- and 2-trifluoromethylthiobenzimidazole.

1-(2,3-Dihydroxypropyl)-, 1-(4-hydroxy-2-oxabutyl)-, 1-(3-hydroxymethyl-4-hydroxy-2-oxabutyl)-, 1-(1,5-dihydroxy-3-oxa-2-pentyl)-, 1-(5-hydroxy-3-oxa-2-pentyl)-, and 1-(4,5-dihydroxy-2-oxapentyl)-2-trifluoromethyl- and -2-trifluoromethylthiobenzimidazoles were obtained by condensation of trimethylsilyl derivatives of 2-substituted benzimidazoles with alkylating agents in the presence of SnCl4, or by direct alkylation of the sodium salts of the heterocycles.