Immunological and biochemical investigations of the infectious bovine rhinotracheitis. III. Alterations in pulmonary surfactant lipids.

The effect of experimental bovine herpes virus (BHV) type I rhinotracheitis on the surfactant system phospholipids in calves was examined. A stimulated exocytosis of pulmonary surfactant phospholipids in the acute phase of the disease was documented biochemically and ultrastructurally. The data presented were assumed as an evidence of the involvement of pulmonary surfactant in lung defense.

[Immunosuppression in an experimental infection with the infectious rhinotracheitis virus]. / Imunosupresiia pri eksperimentalna infektsiia s virusa na zarazniia rinotrakheit.

The changes in the immune status of the calves infected with bovine herpes virus-1 inducing infectious rhinotracheitis were studied. The virus was introduced by intratracheal inoculation of 5 cm3 suspension with minimal concentration of 10(-7) CPU50 per 1 cm2 from the Cervena voda strain cultivated in calf kidney culture. An infection of moderate seriousness and characteristic clinical manifestations was caused. On the 2nd, 5th, 10th and 15th day after the infection lung lavage was carried out and samples were taken from the peripheral blood. The number, viability and differential distribution of the alveolar macrophages and phagocytic and microbicidal ability showed a tendency to decrease during the acute phase of the infection (the 2nd-5th day) followed by a slow restoration in the period of convalescence (the 15th day). Some parameters of the systemic immunity--number of the plaque-forming and the rosette-forming cells, differential and absolute number of leucocytes in the peripheral blood--also had similar dynamics. The changes in the local and in the systemic, in the cell and humoral immunity were connected to the pathogenesis of the infection and the immune suppressive properties of the agent. The rhinotracheitis infection is indicative of the character of changes in the immune status at herpes virus infections and, on the other hand, it can be used as a model for testing immunostimulators of recovery effect.

[The immunostimulating action of suramin in infection with the infectious rhinotracheitis virus]. / Imunovuzstanovitelno deistvie na suramin pri infektsiia s virusa na zarazniia rinotrakheit.

The immunostimulating antiviral preparation suramin has a favourable effect on the process and outcome of an experimental infection with the virus of infectious rhinotracheitis (bovine herpes virus type 1, BHV1), thus reducing the gravity of the clinical course and increasing the survival rate. The therapeutic protective effect of the preparation is expressed in the prevention of virus-induced immunosuppression which is markedly strong during the acute phase of the infection process. Suramin restored the number, viability, relative share in the bronchial lavage population, phagocytic and microbicidal capacity of the alveolar macrophages--a major factor of the local defence mechanisms of the lung. In a similar way suramin influenced some parameters of the systemic immunity (number and differential count of polymorphonuclear phagocytes, plaque- and rosette-forming cells). The application of suramin in doses lower than those used for virus inhibition and its considerable action on different mechanisms of the immune system suggested that the preparation's therapeutic effect could be related mainly to its immunostimulating properties.

Adhesion and phagocytosis of Staphylococcus aureus L-forms.

Electron microscopical investigations on in vitro and in vivo interactions of normal Staphylococcus aureus cells with rat peritoneal macrophages showed that these bacteria were rapidly endocytosed and digested even in the absence of specific antibodies. In contrast to the parental strains oxacilin-induced and stable variante lacking a cell wall (L-forms) were ingested without subsequent formation of phagolysomes and digestive vacuoles. The intracytoplasmic L-form bodies retained their characteristic ultrastructure, i.e. no visible alterations occurred. Some morphological aspects of the L-forms and their persistence in macrophages 7 days after intraperitoneal administration of L-form to rats, suggest the possibility of their intracellular survival.

[Effect of the pesticide carbaryl (sevin) on the course of experimental Erysipelothrix rhusiopathiae infection in rats]. / Vliianie na pestitsida karbaril (sevin) vurkhu khoda na eksperimentalna infektsiia u plukhove s Erysipelothrix rhusiopathiae.

Rats treated with carbaril (sevin) at the rate of 2 to 5 mg were infected via the feed with Erysipelothrix rhusiopathiae in the course of 30 days. Studied were the clinical picture, some paraclinical indices, the mortality rate, and the morphologic and histopathologic changes in the parenchymal organs. It was found that rats that were given carbaril for a long time in minimum amounts and were then subjected to infection developed a characteristic clinical picture and showed a high mortality rate (nearly twice as high as that with the control animals). In hemocultures the causative agent was isolated over a longer period than in the case with the controls. Both the gross and the histopathologic findings were more strongly manifested in the test (carbaril-treated) rats.