Micro ELISA and indirect haemagglutination tests in the diagnosis of Taenia hydatigena metacestode infections in lambs

Of 48 lambs slaughtered at a local abattoir, 60.4% were either found to be infected with Taenia hydatigena cycts, or showed evidence of abortive infections (white spots on the liver) with that parasite. The micro ELISA test and the IHA test did not distinguish between animals showing evidence of infection at slaughter and those which did not. Both tests gave results which correlated significantly with each other. The antigens used in the tests cross-reacted with each other, which may be the reason for the large number of false negative results.     

Geomagnetic Variations in the Eastern United States: avidence for a Highly Conducting Lower Crust?

Temporal geomagnetic variations, recorded at ten stations across the eastcentral United States, are interpreted in terms of the electrical conductivity structure of the earth beneath this region. The results are surprising and suggest that the lower crust is highly conducting, having distinct lateral variations in conductivity beneath the Appalachian Mountains.     

BLOOD GLUTATHIONE PEROXIDASE ACTIVITY IN HORSES IN RELATION TO MUSCULAR DYSTROPHY AND SELENIUM NUTRITION

The activity of glutathione peroxidase, a selenium containing enzyme, was measured in the blood of horses to determine its usefulness as an indicator of selenium status. In 15 horses the enzyme activity was positively related to the blood selenium concentration (P<.001, r - 0.98) over the range of enzyme activities of 8.2 to 140 units (μmoles NADP-oxidised/min/gHb) and selenium concentrations of 0.24 to 2.74 μmol/k1. In a group of 8 horses which 2 foals had died with lesions of muscular dystrophy the enzyme activity increased from a mean of 11.8 units before treatment with selenium to 34.5 units after 2 intravenous injections of sodium selenite given one month apart. Another group of 8 horses grazing paddocks adjacent to this affected group did not receive any selenium treatment and had a mean enzyme activity of 11.9 units. Blood glutathione peroxidase activity was measured in 50 pasture-fed horses and 180 stallfed horses. The range of activities found (7 to 158 units) indicated that selenium intake in horses varied widely between localities. All pasture-fed horses grazing areas where muscular dystrophy had occurred in foals had low activities (less than 20 units). In stall-fed horses the enzyme activity was influenced by selenium treatment, and horses which had been treated usually had higher activities than horses in the same stable with no history of selenium treatment. It was concluded that blood glutathione peroxidase is a suitable indicator of selenium status in horses.     

Metabolism of a synthetic insect juvenile hormone (JH-I) during the development of Tribolium castaneum (herbst) (coleoptera,tenebrionidae)

Metabolites produced from ¹⁴C-labelled C-18 juvenile hormone (JH-I) topically applied to the flour beetle Tribolium castaneum were measured in larvae aged 21 and 28 days, pupae at four stages of development, and newly emerged and mature adults. The hormone was metabolized rapidly, in all stages examined, to form the corresponding diol-ester, acid-epoxide, and acid-diol derivatives, the diol-ester derivative being the major metabolite produced. The metabolism of JH-I was most rapid at the times of the larval/pupal and pupal/adult transformations. The differences in the rate of metabolism appeared to be correlated with changes in the production of the diol-ester derivative. Similar metabolic changes may regulate the levels of endogenous juvenile hormones during development in this species.