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Biomedical subjects

R M Barlow

Publications and source records attributed to R M Barlow.

At least 37 records · Page 2Linked to original sources

Causes of hypothermia in 89 lambs.

The causes of hypothermia in 89 lambs were identified on the basis of history and clinical biochemistry. Excessive heat loss accounted for 24 per cent of the cases, and depressed heat production because of either severe hypoxia during birth, immaturity or starvation accounted for 72 per cent. Exhaustion of energy reserves and hypoglycaemia were marked characteristics of lambs which became hypothermic after 12 hours of age. Most of the lambs were either twins or triplets. The implications of the findings for both the treatment and prevention of hypothermia in newborn lambs are discussed.

Animals↗

Mannosidosis in Aberdeen Angus cattle in Britain.

Mannosidosis, an inherited and lethal lysosomal storage disease of Aberdeen Angus cattle, was diagnosed on a farm in north-east Scotland. Two affected calves were examined in detail. Both were poorly grown and ataxic, though the intention tremor and aggression considered characteristic of the disease were not recorded. Histological examination revealed typical vacuolation of nerve cells, fixed macrophages and epithelial cells of the viscera. Deficiency of the enzyme alpha mannosidase was demonstrated. The epidemiology of the disorder in Scotland is considered and control methods indicated.

Animals↗

Morphogenesis of cerebellar lesions in bovine familial convulsions and ataxia.

Cerebellar lesions develop in a heritable disorder characterized by recurrent episodic seizures in newborn and young calves and by ataxia in survivors of several bouts of convulsions. Earliest changes were altered patterns of phosphatase reaction products in Purkinje cells. Purkinje cells axons in the outer half of the granular layer developed fusiform or spheroidal argyrophilic swellings. Early lesions were restricted to the lingula and uvula, but cases with more persistent clinical disease involved other parts of the vermis. In ataxic calves these lesions were also in the cerebellar hemispheres. The axonal swellings showed proliferation of tubulovesicular endoplasmic reticulum, neurofibrils and mitochondria. In other swellings axoplasm was degenerate, and in some it resembled Purkinje cell cytoplasm. In some clinically normal adult transmitters of the disorder, light microscopy showed some similar swellings, but most calves that recovered had no lesions.

Animals↗

The definition of border disease: problems for the diagnostician.

Inocula derived from two sources of typical border disease (BD) and designated BP-77 and H-77 respectively, were prepared and injected into pregnant ewes of four breeds. The BP-77 inoculum produced higher serum neutralising antibody titres to the cytopathic BD virus than to the NADL strain of bovine virus diarrhoea virus. Only typical BD occurred among the progeny of all four breeds. In contrast H-77 produced higher titres to bovine virus diarrhoea than to BD and typical BD occurred only in the progeny of two of the four breeds. Progeny of the other two breeds appeared normal or had a range of malformations of the central nervous system but none of the characteristic clinical or pathological stigmata of BD. The existence of more than one strain of BD virus is confirmed. Virus strain/host genotype interactions may affect the character of disease in the progeny. The possible implications for diagnosis and control are discussed. It is concluded that the generally accepted criteria for diagnosis of BD are no longer adequate and that the disorder should be redesignated.

Animals↗

A rigid lamb syndrome in sheep in Rhodesia.

A syndrome characterised by the birth of lambs with varying degrees of rigidity of the limbs and spine has been encountered on several occasions in Rhodesia. Outbreaks have occurred in autumn-born lambs from Dorper ewes grazing heavily fertilised Star grass cv No 2 (Cynodon aethiopicus) pastures. The condition appears to be exacerbated by the application of sulphur to the pasture and is partly prevented by the administration of selenium and vitamin E to the ewes before lambing. The aetiology is unknown.

Animals↗