Surfactants for the control of apple mildew

Reduction of the overwintering powdery mildew fungus Podosphaera leucotricha resulted from one application of a variety of surfactants (at 50 g/litre a.i.) to apple trees during the dormant season. Examples of non-ionic, anionic and cationic materials were tested and some gave promising control. Successful treatments delayed bud burst during the following spring and caused some loss in fruit yield.     

Analysis of the outer membrane proteins of Bacteroides nodosus, the causal organism of ovine footrot

Examination by SDS-PAGE of lithium acetate extracts of several strains of depiliated Bacteroides nodosus revealed 6 major outer membrane proteins (including pilin). The 5 membrane proteins exhibited approximate molecular weights of 75000, 50000, 38000, 34500 and 26500 whereas pilin had a MW of 17500 for the majority of strains. All proteins were accessible to lactoperoxidase-catalysed iodination and proteins 1, 2 and 5 were shown to be glycoproteins. Several attempts to isolate individual OMC proteins in pure form by selective solubilization and gel filtration were unsuccessful, but electroelution of individual outer membrane complex proteins resolved by SDS-PAGE provided sufficient quantities of antigen for immunization of sheep and for immunochemical analysis.     

Transmission of hog hog cholera virus by mosquitoes.

Mosquitoes trapped during an epizootic of hog cholera (HC) in Maryland in 1969 were prepared into 40 pools which were inoculated in pigs. Hog cholera virus was confirmed in pigs inoculated with 8 of 40 pools of mosquitoes. Generally, the pigs contracting HC developed chronic infections with persistent viremia that lasted 30 or more days. Two pigs seemed healthy when euthatized 62 and 80 days after inoculation, yet viremia of high titer was detected in each. Experimental studies were performed with 2 laboratory strains of mosquitoes, Aedes aegypti and Culex tarsalis, to determine if biological and mechanical transmission occur. Biological transmission was not confirmed, but HC virus was retained in A aegypti for 3 days. Mechanical transmission was confirmed with A aegypti in 2 of 9 experiments.     

Diarrhoea in dairy calves reduced by feeding colostrum from cows vaccinated with rotavirus

Forty-two dairy calves remained with their dams for two days after birth, and then were removed to a calf rearing shed. Calves were allocated to three groups for the next 14 days, and received twice daily either whole milk, whole milk with a 10 per cent supplement of pooled normal bovine colostrum or whole milk with 10 per cent supplement of colostrum from cows vaccinated with rotavirus. A natural outbreak of diarrhoea occurred, affecting 28 of the 42 calves. Feeding immune colostrum delayed the onset of diarrhoea, and reduced its incidence, duration and severity. Live weight gains were consequently improved. The group fed normal colostrum had diarrhoea intermediate in severity between that of control calves and those fed immune colostrum. The aetiology of the diarrhoea was complex, with calves excreting rotavirus, enteropathogenic Escherichia coli and cryptosporidia.     

Medical management of spinal cord disease

In spinal cord disease of horses, a complete history, neurologic examination, and adjunctive diagnostic procedures are very helpful in establishing a tentative diagnosis; however, a definitive diagnosis may be difficult or impossible to establish antemortem. Medical management should be initiated with full consideration of possible etiologies and knowledge of the effects and consequences of medical therapies. This article discusses the drugs commonly used in the management of spinal cord disease and the rationale for their use.