Acute oxalate poisoning attributable to ingestion of curly dock (Rumex crispus) in sheep

Ten of 100 mature ewes were afflicted with acute oxalate toxicosis within 40 hours after being temporarily penned in a lot that contained considerable growing Rumex crispus (curly dock). Clinical signs of toxicosis included excess salivation, tremors, ataxia, and recumbency. Affected ewes were markedly hypocalcemic and azotemic. Oxalate crystals were not observed in urine. Gross postmortem lesions were minimal and nondiagnostic in 2 ewes that died peracutely, but perirenal edema and renal tubular degeneration were clearly observable in ewes euthanatized on the third day of toxicosis. Diagnosis of oxalate toxicosis was confirmed by histopathologic findings. Samples of Rumex spp contained 6.6 to 11.1% oxalic acid on a dry-weight basis, a concentration comparable with that in other oxalate-containing plants that have caused acute oxalate toxicosis.     

LHRH and beta-endorphin in the hypothalamus of the ram in relation to photoperiod and reproductive activity

The regional distribution and relative concentrations of LHRH and beta-endorphin immunoreactivity in the hypothalamus were compared in sexually active and sexually inactive Soay rams. LHRH was localized principally in the medial basal hypothalamus and median eminence with lower concentrations in the anterior hypothalamus and preoptic area. beta-endorphin immunoreactivity was also found in highest concentrations in these regions but was more widely distributed into the rostral, dorsal and lateral parts of the hypothalamus. LHRH content in the medial basal hypothalamus was significantly lower in the sexually active rams compared to inactive rams while there was no difference in beta-endorphin immunoreactivity content between the two groups. Gel filtration chromatography of hypothalamic extracts revealed that the beta-endorphin immunoreactivity was due to both beta-lipotropin and beta-endorphin; the ratio of beta-endorphin: beta-lipotropin tended to be less in the sexually active rams than in the sexually inactive rams. The results are consistent with the hypothesis that beta-endorphin is a physiologically important endogenous opioid involved in the modulation of LHRH secretion.     

Continuing presence of rinderpest virus as a threat in East Africa, 1983-1985

The re-emergence of rinderpest virus in East Africa in 1979 caused widespread outbreaks of disease and subclinical infection throughout the region until mid-1983. Subsequent massive emergency vaccination campaigns have been successful in eliminating clinical rinderpest from Tanzania and preventing its spread southwards. Unfortunately the virus is still endemic in north-eastern Uganda and has recently caused epidemic outbreaks with high mortality in cattle in that country. In Kenya, buffaloes (Syncerus caffer) in and around the Masai Mara game reserve have developed antibodies to rinderpest virus as recently as late 1984. Although there have been no outbreaks of clinical disease in Tanzania or Kenya from April 1983 to the end of 1985 this serological evidence plus the increasing incidence of clinical outbreaks in Uganda indicate that rinderpest virus still threatens East Africa. The substantial aid which has been provided to the region for rinderpest control must be maintained.     

The effects of ergosterol on the response of female chicks to oral oestrogens and progestogens.

The chick-oviduct assay was used to investigate the effects of dietary ergosterol on the response to oral progestogens and oestrogens. 2. Progestogens alone had no effect on the oviduct but the hypertrophy due to oestrogen was greatly enhanced by simultaneous treatment with progestogen at all dose levels tested. 3. Ergosterol had no effect on any of the responses of the oviduct studied.     

Immune responses to mycoplasma infections of the respiratory tract

Mycoplasmas are capable of causing respiratory disease in a number of species of animals. The pathogenicity of the mycoplasma species ranges from those that cause major disease outbreaks and economic loss to what might be considered the more highly evolved and successful parasites at the other end of the spectrum that survive for long periods in the host without being recognised and evicted. This prolonged colonisation of mucous membranes which is typical of many mycoplasmas is related to certain unique features of the mycoplasma and its interaction with the hosts immune system. An initial step in infection is the attachment of the mycoplasma to the epithelial lining of the respiratory tract. Lack of cell wall confers plasticity and may engender the intimate association of mycoplasma and host cell that has been noted. This in turn may favour persistence of the extracellular parasite. Before the specific immune response is produced avoidance of the non-specific immune mechanisms would clearly aid survival. Both passive (capsules) and active (toxic effects) mechanisms of avoiding phagocytosis have been proposed. Both humoral and cell mediated responses are generated by mycoplasma infections. The serum antibody response follows the usual course IgM, G and A. The indications of cell mediated immunity that have been reported include; delayed type hypersensitivity reactions, lymphocyte transformation responses and inhibition of macrophage migration. The concept that the pathological lesions are in a large part due to host reactivity is well accepted. The lung lesions may contain infiltrating and dividing lymphocytes some of which are producing specific antibody. Evidence for the lung lesion in some animals being partly due to the hosts cell mediated response has also been produced. The local immune response appears to be of greater relevance to immunity to infection than the systemic response, in general the association between local antibody and immunity is much better than for serum antibody. Of particular note is the high contribution of local IgG production, particularly in the lower respiratory tract. Attempts are now being made to use this increased understanding to produce effective killed vaccines that produce immune responses in the lung. Such studies will hopefully lead to the development of 'killed' vaccines that are effective. It can be urged that mycoplasmas would be less pathogenic if they did not produce an inflammatory response and some species have been shown to have an immunosuppressive effect. Such a property could affect the lesion, and hence pathogenicity, and also aid mycoplasma persistence.(ABSTRACT TRUNCATED AT 400 WORDS)     

Analyte comparisons on the Coulter Dacos and Kodak Ektachem DT-60 clinical chemistry analyzers

Eighteen analytes were compared using the Coulter Dacos and Kodak Ektachem DT-60 chemistry analyzers. All analytes were significantly linearly related. Correlations were excellent for fifteen analytes (r > 0.95); the correlations for sodium, chloride, and total protein were less than 0.95 but greater than 0.90. Several analytes had slopes significantly different from unity which was likely related to methodological differences. Regression equations are presented for the conversion of data generated using the Kodak Ektachem DT-60 to Coulter Dacos values so that, in the University of Guelph clinical pathology laboratory, one set of reference intervals serves both instruments. These data are directly applicable only in the laboratory in which they were developed. They should not be utilized directly in other laboratories, but can be used as general guidelines until confirmatory studies are done.     

The permeability of plant cell walls as measured by gel filtration chromatography

The permeability of plant cell walls to macromolecules may limit the ability of enzymes to alter the biochemical and physical properties of the wall. Proteins of molecular weight up to 60,000 can permeate a substantial portion of the cell wall. Measurements of wall permeability in which cells are exposed to hypertonic solutions of macromolecules may seriously underestimate wall permeability.