Equine viral arteritis at a veterinary teaching hospital

An outbreak of equine viral arteritis (EVA) occurred at a veterinary teaching hospital in the summer and autumn of 1984. Clinical signs were observed in 16 out of 61 hospitalized horses and included ventral, limb and preputial edema, mild conjunctivitis with lacrimation, pyrexia and increased respiratory and heart rates. Of 16 clinically affected horses, 13 were undergoing experimental abdominal surgery and/or were involved in digestion experiments; 9 of the 13 were > 20 years of age. The three other clinically affected horses were client animals. Thirteen client horses developed serologic titers to equine arteritis virus in the absence of clinical signs. The risk of infection was associated with close contact, involvement in the experimental studies being conducted and length of hospitalization. The disease was mild, limited in spread and successfully controlled by quarantine.     

Integrated assessment of catchment suspended sediment budgets: a Zambian example

In many developing countries, the management of sediment‐related environmental problems is severely hampered by a lack of information on sediment mobilization and delivery in river basins. The sediment budget concept represents a valuable framework for assembling such information, which can, in turn, be used to assist with the design and implementation of soil erosion and sediment control policies. However, the information necessary to construct a catchment sediment budget is difficult to assemble. Against this background, an integrated approach to establishing a catchment suspended sediment budget, involving a river monitoring station, the use of ¹³⁷Cs measurements to estimate soil erosion and deposition and floodplain accumulation rates within the catchment, and sediment source fingerprinting, has been developed and tested in the 63 km² catchment of the upper Kaleya River in southern Zambia. The approach developed not only provides detailed information on individual components of the suspended sediment delivery system, but also permits the establishment of the overall catchment sediment budget. A sediment budget for the upper Kaleya catchment is presented and both its key features and its wider implications for catchment management are discussed. Copyright © 2001 John Wiley & Sons, Ltd.     

Gas-liquid chromatographic/mass spectrometric screening method for T-2 toxin in milk

A method for the analysis of T-2 toxin in milk is presented. Ethyl acetate extracts of milk samples which had been spiked with T-2 toxin were purified by thin layer chromatography and derivatized with N,O-bis(trimethylsilyl)acetamide to produce the T-2 toxin trimethylsilyl ether (T-2 toxin-TMS). N,O-bis(trimethylsilyl-d9)acetamide was used to make T-2 toxin d9-trimethylsilyl ether (T-2 toxin-d9 TMS) which was added to the derivatized milk extract as an internal standard. Samples were analyzed by combined gas-liquid chromatography/mass spectrometry using either electron impact ionization or chemical ionization mass spectrometry. In electron impact ionization analyses, simultaneous monitoring of the T-2 toxin-TMS fragment ion at m/z 436 and the T-2 toxin-d9TMS fragment ion at m/z 445 gave a T-2 toxin-TMS detectability estimated at 6 microgram/kg. In chemical ionization analyses, the T-2 toxin-TMS fragment ion at m/z 377 and the T-2 toxin-d9TMS fragment ion at m/z 386 were simultaneously monitored to give a T-2 toxin-TMS detectability estimated at 3 microgram/kg. Average recovery was 85% at 200 microgram/kg and 65% at 20 microgram/kg.     

Distribution of CCR3 mRNA expression in horse tissues

CCL11 (also known as eotaxin) is a very potent and selective mediator of eosinophil migration which exerts its effects through its receptor, CCR3. In this study we report the cloning of an equine CCR3 cDNA sequence and investigation of the localization of CCR3 mRNA expression in horse tissues. Equine CCR3 displayed high levels of sequence identity with CCR3 sequences in other species. RT-PCR analysis revealed the expression of CCR3 in colon, lung and spleen of normal horses. In situ hybridisation experiments indicated that expression of CCR3 mRNA in colon was predominantly in eosinophils and to a lesser extent in mast cells, whereas CCR3 was seen mainly in lymphocytes of the lung and spleen. In view of the role of CCR3 in the recruitment of cells into sites of allergic inflammation, equine-specific CCR3 sequence data and information on tissue localization will be of potential benefit in the development of CCR3-targeted anti-inflammatory therapies in the horse.     

Enzyme-linked immunosorbent assay of benomyl and thiabendazole in some foods

Enzyme-linked immunosorbent assays were developed for benomyl as its decomposition product, methyl 2-benzimidazole carbamate, and thiabendazole in foods. Immunogens consisting of human serum albumin coupled to 2-succinamidobenzimidazole or 2-(2'-succinamido-4'-thiazolyl)benzimidazole were used in rabbits to raise antisera that were specific for the respective fungicides. Lower limits of quantitation of 0.35 ppm for benomyl and 0.03 ppm for thiabendazole were established without cleanup of the ethyl acetate extract. Recoveries of benomyl from 3 crops spiked at 0.5 to 10 ppm averaged 89% (range 73-109%) and of thiabendazole from 5 crops spiked at 0.1 to 2.0 ppm were 93% (range 81-105%).     

Carotenoid changes of intact watermelons after storage

Watermelon contains lycopene, a red carotenoid pigment that has strong antioxidant properties. The lycopene content of watermelon is substantial, contributing 8-20 mg per 180 g serving. There are no reports on carotenoid changes in whole watermelon during storage. Three types of watermelon, open-pollinated seeded, hybrid seeded, and seedless types, were stored at 5, 13, and 21 degrees C for 14 days and flesh color, composition, and carotenoid content were compared to those of fruit not stored. Watermelons stored at 21 degrees C had increased pH, chroma, and carotenoid content compared to fresh fruit. Compared to fresh fruit, watermelons stored at 21 degrees C gained 11-40% in lycopene and 50-139% in beta-carotene, whereas fruit held at 13 degrees C changed little in carotenoid content. These results indicate that carotenoid biosynthesis in watermelons can be affected by temperature and storage.     

Lesions of spinal cord parelaphostrongylosis in sheep. Sequential changes following intramedullary larval migration

Spinal cord nematodiasis epidemiologically, clinically, and histologically consistent with Parelaphostrongylus tenuis infection was noted in two flocks of sheep. Spinal cords from two sheep with active infection and one from a partially recovered animal were studied in an effort to determine the sequence of lesions following larval invasion of the central nervous system. In the former two sheep, migration of larvae within the spinal cord induced asymmetrically irregular tracks of disrupted and necrotic tissue, primarily in white matter. Subsequently, macrophages infiltrated these regions and phagocytized the necrotic tissue, which led to cavity formation. Swelling and loss of axons, diminished myelin staining, mononuclear cell infiltration and increase in astrocytic fibers were often seen in adjacent tissue. Only occasional coiled larvae were found in these actively infected animals. Late stage lesions in the white matter in the partially recovered sheep included multiple small astrogliotic regions with diminished myelin and axonal content, and a single large multicavitary, atrophic, gliotic zone.     

The effect of various flooring materials on performance and foot health of early-weaned pigs

The effects of various flooring materials on the performance and foot health of early-weaned piglets were evaluated in seven trials using 728 pigs. Pigs housed on galvanized flattened expanded metal, plastic-coated expanded metal, perforated galvanized panels, galvanized woven wire and plastic-coated woven wire had similar average daily gains, average daily feed intakes and feed/gain ratios. Foot pad scores were lower (less cuts, cracks and abrasions) for plastic-coated expanded metal, plastic-coated woven wire and perforated galvanized panels than for galvanized expanded metal and galvanized woven wire. While foot pad scores varied among flooring materials, none of the flooring materials produced lesions that resulted in any visible discomfort or inhibition of locomotion of the pigs. Correlation coefficients between individual pig body weight and foot pad scores were positively related indicating that body weight may be a factor contributing to lesion severity. Although foot pad lesions were common in the weanling pigs, with some variation due to flooring materials, there were no differential effects among the flooring materials evaluated on performance or visible comfort of the pigs.