Squalene in petroleum asphaltenes

Squalene, 2,6,10,15,19,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene, a new biological marker, has been detected in various petroleum asphaltenes and their pyrolysis products. Since squalene is the most common triterpenoid in nature and the biological precursor of the important tetra- and pentacyclic triterpane markers, its detection in asphaltene suggests new ways for marker correlations.     

Observations on Diseased Pigs with High Sulfate Intake and Normal Tissue Copper Levels

Disease in a large pig herd reared intensively and kept on sulfate-rich drinking water is described. It is the first report of diseased progeny of sows with high sulfate intake. Results of two surveys are presented, one for water with sulfate in excess of 2000 ppm and one for water with less than 1000 ppm. The management practices are described in detail. Disease of Survey I was manifested by high morbidity and mortality (50% of 600) in piglets, incoordination in piglets and some adult stock and osteopathy in piglets and weaners. In Survey II disease was less severe and restricted to piglets. Detailed histopathological studies revealed myelin deficiency in brain and spinal cord of sows and piglets, interferred endochondreal ossification of long bones of piglets and weaners, fatty changes of livers and interstitial nephritis in piglets and weaners. The changes in the nervous tissue were considered due to delayed fixation as tissue was only immersed in fixative and not perfused with it immediately after death. Similar changes have been described for pigs deficient in copper. Copper content of tissue and body fluids of pigs of this study were normal, as were the serum inorganic phosphate and total calcium levels. The bone changes observed have also been reported for rats given dextran sulfate injections, for pigs on experimental low-copper sulfate-enriched diet and for pigs reported low in copper and fed a diet supplemented with sulfide. The cause of the locomotor disturbance and mortality in piglets was not established.     

Transmission of virulent footrot between sheep and goats

OBJECTIVE: To determine the infectivity of ovine and caprine strains of Dichelobacter nodosus for both sheep and goats. DESIGN: Pen experiments in which 20 sheep and 19 goats were challenged directly with the two strains, and transmission experiments on pasture, using donors infected by experimental challenge. RESULTS: Sheep and goat strains of D nodosus infected both animal species in experimental challenges. Animals so infected transmitted footrot to both sheep and goats on pasture plots. A significantly smaller proportion of goats than sheep was infected when challenged with either strain. The interval between exposure and development of footrot in goats was longer than in sheep when recipient animals were exposed to infected donors on pasture. The disease was less invasive in goats than in sheep. CONCLUSIONS: With the strains of D nodosus used there was no evidence of host specificity. Direct transmission of footrot can occur between sheep and goats in the same environment. There is a need to include goats in ovine footrot eradication programs and vice versa.