Annales de recherches veterinaires. Annals of veterinary research最新文献

The disposition of radiotocopherol after intraperitoneal administration of 14C-labelled-DL-alpha-tocopherol (1 microCi/kg bw, dose 1) and 3H-labelled-DL-alpha-tocopherol (4 microCi/kg bw dose 4) and of D-alpha-tocopherol, after intraperitoneal administration of DL-alpha-tocopherol acetate (100 mg/kg bw) was investigated in sheep. Plasma samples were taken at regular intervals after dosing and assayed for radioactivity and D-alpha-tocopherol. Plasma profiles were modelized using a compartmental approach and the input entry rate (for radioactivity) was identified using a numerical deconvolution method. Based on plasma specific activity (dose 1 and dose 4) and D-alpha-tocopherol plasma concentration (unlabelled alpha-tocopherol acetate), half-lives were not significantly different (99.6 +/- 28.3 h, 121.3 +/- 38.5 h and 75.0 +/- 49.75 h after dose 1, dose 4 and unlabelled alpha-tocopherol respectively). The times to reach maximal plasma concentrations were similar for the 3 test articles (mean values ranging from 21.5 to 26.7 h). The only significant difference was observed for the apparent volume of distribution (with respect to bioavailability) which was much larger for the unlabelled test article. Deconvolution study of plasma specific activity showed: i), that the maximal input rate was reached only after a short delay (3 to 12 h); ii), that half of the activity was absorbed after a delay of 38.13 +/- 16.76 h (dose 1) and 44.3 +/- 6.50 h (dose 4); and iii), that 90% of the activity was absorbed after 151.2 +/- 27.3 h (dose 1) and 162.3 +/- 11.2 (dose 4). It is concluded that the intraperitoneal route is of interest for alpha-tocopherol administration, but that more information is required to determine the exact process of absorption.

An experimental paratuberculosis study was performed in sheep. One group of 6 lambs was inoculated intravenously with the equivalent of 50 mg (wet weight) of live bacilli, another group of 6 lambs was inoculated orally by placing 500 mg (wet weight) of live organisms in milk feed and a group of 3 lambs was used as controls. The degree of cellular immunity was followed by examining delayed hypersensitivity using 3 allergens (bovine tuberculin PPD, avian tuberculin PPD and johnine PPD) and that of humoral immunity using complement fixation test, agar gel immunodiffusion test and ELISA. The elimination of bacilli in the faeces was examined simultaneously. After 2 years no macroscopic or microscopic lesion was observed in intravenously inoculated lambs and in those exposed orally to M paratuberculosis; cultures were negative. It appears that domestic sheep were able to control the infection. Nevertheless, most of them developed cellular and humoral immunity against paratuberculosis antigen. The best results were obtained in intravenously inoculated lambs.

One hog cholera virus strain isolated from an outbreak of the disease in a wild boar breeding herd in Brittany (France) in 1990 has been characterized with a panel of monoclonal antibodies to hog cholera virus and ruminant pestiviruses: the strain was found to be indistinguishable from that of other domestic pig isolates. The pathogenicity of the strain to domestic pigs was evaluated by infecting intranasally, intramuscularly and by contact 17 specific pathogen-free 6-week- and 12-week-old pigs. Sixteen of the 17 pigs showed symptoms of hog cholera. The virus was detected in the blood of the 16 pigs during all phases of hyperthermia which persisted up to death or the terminal phase, ie between 16 and 29 days post-infection. One animal recovered after presenting a mild form of the disease. This pig was the only one which raised antibodies to the virus. Typical hog cholera lesions were observed in 2 pigs only; the other animal showed very few pathological changes. No relationship between intensity or duration of the disease and pathological changes could be established.

Pulmonary intravascular macrophages (PIMs) are mononuclear cells found apposed to the lung capillary endothelium in a number of mammalian species. Although first described in the 1970s, it was not until the 1980s that they were more completely described. In several species of veterinary interest (bovine, porcine, ovine, and feline), PIMs are very important in blood clearance, which is not the case in mice and rats. Only recently have the immunological activities of PIMs been verified. In this review, we present an overview of PIM research with particular emphasis on the immune functions of this highly reactive macrophage population.