Biochemical studies on geeldikkop and enzootic icterus

The haematology, chemical pathology, disturbed biochemistry, general enzymology and histopathology of geeldikkop, enzootic icterus and icterogenin intoxication in sheep are presented in full for the first time. The relationship of geeldikkop to enzootic icterus is demonstrated and both diseases are shown to be the result of sudden catastrophic failures of membrane permeability in various tissues of the body. The conditions are thought to be two different manifestations of a single disease entity, possibly low grade selenium intoxication. The acute manifestations are precipitated by various forms of non-specific stress the effects of which, on sheep from the areas where the diseases are enzootic, are described. One of the most important factors in this regard is thought to be a virus infection similar in nature to bluetongue. The chemical pathology and haematology of mild bluetongue infections in sheep are thus described in detail. The chemical nature of the ovine bile pigments is described and methods are given for their isolation and identification, as well as for the isolation of bromsulphalein conjugates formed by the ovine liver. Methods are given for the determination of copper in body fluids and tissues, the various copper fractions in blood, and iron and selenium in body tissues. The diagnosis of ovine liver, renal and adrenal dysfunction and myopathy by means of clinical laboratory tests is fully dealt with. Intermediary metabolism in the ovine red cell is discussed and activity levels of numerous metabolic enzymes in these cells are presented for consideration. Carbohydrate metabolism in the sheep as it is revealed by a study of the disturbances seen in geeldikkop forms an important theme of this thesis.The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Biochemical studies on aflatoxicosis

Biochemical studies have been made on liver tissue and blood from ducklings and various breeds of chickens maintained on standard rations containing 0·5 ppm of aflatoxin B₁. The results obtained from these birds were compared with those from birds of the same age maintained on groundnut-free mashes. Of the various breeds of chickens studied, only New Hampshires have been found to be susceptible to the effects of this level of aflatoxin. In the livers of affected chickens and ducklings a marked decrease in the activity of certain mitochondrial dehydrogenases and enzymes of the electron transfer chains or oxidative phosphorylation mechanisms is apparent. Mild to moderate anaemia, severe hypo-proteinaemia and grossly abnormal plasma protein electrophoretograms are presented by affected birds. It is believed that the suppression of protein synthesis observed and affecting the albumin fraction in particular, is due to a lowered rate of ATP synthesis consequent to mitochondrial injury. An increase in the activity of certain plasma enzymes, notably those of lactic dehydrogenase, aldolase and glutamic-oxalacetic- or glutamic-pyruvic transaminases, is also seen in these birds. This increase in the activity of plasma enzymes can be correlated with the severe hepatic lesions. The use of these various studies in the diagnosis of this condition, before hepatic lesions are evident, has been suggested. The ability of affected birds on rations containing 0·5 ppm of aflatoxin to recover rapidly when placed on toxin free rations is noted. Aflatoxin at these levels appears to have no cumulative effects, but no resistance is built up to its actions by tissues of birds exposed to it for long periods. Susceptible birds revealed no evidence of aflatoxicosis after prolonged feeding of dairy or poultry products obtained from cows or fowls kept on highly toxic rations. From the practical point of view there seems to be little danger inherent in the dietary use of such essential foods.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Contributions to the study of blood constituents in domestic animals in South Africa. 3. Normal values for the activity of glyceraldehyde-phosphate dehydrogenase and glucose-6-phosphate dehydrogenase in the erythrocytes of sheep

Normal values have been established for the activity of glyceraldehyde-phosphate dehydrogenase and glucose-6-phosphate dehydrogenase in the erythrocytes of sheep maintained under experimental and field conditions in South Africa. The 10 per cent lower, 80 per cent and 10 per cent upper limits have been established for the former enzyme as 400- 424, 425-730 and 731-900 micrograms/ml of blood respectively. Negligible activity of the latter enzyme has been demonstrated in the ovine erythrocyte by three different methods. Glycolysis in the red blood cells of the sheep is believed to proceed mainly via the direct Embden-Meyerhof pathway. The importance of these findings with regard to the ovine disease syndromes, geeldikkop and enzootic icterus, is mentioned.The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

A survey of the occurrence of potentially harmful amounts of selenium in the vegetation of the Karoo

The selenium content of the vegetation of the Karoo has been investigated. It is clear that given suitable conditions numerous species of plants in this area can take up moderate to dangerous amounts of the element. A tentative classification of these plants on the basis of apparent selenium uptake has been attempted. Correlation between selenium content of the vegetation and the incidence of geeldikkop and enzootic icterus is demonstrated. The effects of veld mismanagement in relation to these disease problems are indicated.The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Chemical studies on blood and tissues from Angora goats carrying to normal term and from habitually-aborting animals

The results of a comparative study of the haematology and the levels of various constituents of blood taken from certain groups of ewes emanating from farms where abortion was either not known to have occurred previously and where it was most prevalent, are reported. Anaemia consequent to verminosis, sideropaenia and chronic hepatic disease are cited as possible contributing factors in the aetiology of Angora goat abortions and neonatal kid mortality. A marked difference in the liver iron and selenium content between normal and pathological foetuses has been observed. This is interpreted as evidence of early impairment in the placental transfer of nutrients between mother and foetus. Hypocupraemia was encountered in most of the animals studied. Copper deficiency in the areas concerned may be an important secondary factor on some farms.The articles have been scanned in colour with a HP scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to final presentation PDF-Format

Contributions to the study of blood constituents in domestic animals in South Africa. 4. Normal values for haemoglobin and plasma calcium, inorganic phosphate, magnesium, iron and copper in the blood of Angora goats in the Cape Midlands

Normal values have been established for haemoglobin and plasma calcium, inorganic phosphate, magnesium, iron and copper in the blood of Angora goats maintained in the Cape Midlands of South Africa. With the exception of the values obtained for haemoglobin, the data collected for these determinations present slightly to considerably skewed distribution curves. Normal values have been established by using cumulative relative frequency polygons constructed from these data.The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

A preliminary report on the occurrence of selenosis in South Africa and its possible role in the aetiology of tribulosis (geeldikkop), enzootic icterus and some other disease conditions encountered in the Karoo areas

Selenosis is described, it is believed for the first time, as being a potential grazing hazard in many parts of this country, especially in the Karoo areas. A review of the symptomatology, pathology and epizootology of the condition as it is known elsewhere in the world is presented together with a short account of experimental selenosis and some of the known actions or toxic effects of the element on the body. A brief description of some disease conditions which are believed to be essentially chronic selenosis syndromes is given, and some thoughts are advanced as to the possible role of selenium intoxication in the two conditions known as tribulosis ovis (geeldikkop), and enzootic icterus. In conclusion the results of numerous analyses of animal and plant tissues for selenium are presented, which indicate the presence of dangerous amounts of this element in the material examined.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

The urinary excretion of 5β-pregnane-3α : 20α-diol and gestational failure in Angora goats

The urinary excretion of pregnanediol has been studied over the full period of gestation in a group of twenty Angora ewes. A comparison is drawn between animals in which conception presumably did not occur, those which kidded normally producing strong healthy kids, and those which produced weak undersized young, stillborn kids or aborted before term. Evidence is presented suggesting that abortion, prenatal and some instances of neonatal mortality in these animals are associated with deficient luteal function and progesterone secretion during the first third of the gestational period. The urinary excretion of pregnanediol during this period appears to be a useful prognostic guide as to the outcome of gestation in pregnant Angora ewes.The articles have been scanned in colour with a HP scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to final presentation PDF-Format

Biochemical studies on a suspected lysosomal storage disease in Abyssinian cats

Blood lipid analysis was performed on the serum of 2 normal kittens and 1 adult cat and on serum from 3 affected kittens. Thin layer chromatography was done on tissue extracts of various organs from clinically affected kittens and unaffected unrelated kittens of a similar age, and on serum from carrier cats, affected kittens, related unaffected kittens and unrelated kittens. Spleen and lymph node cell cultures were prepared from 1 affected kitten and the growth medium and cell cultures were analysed for lipids. A lecithin-like phospholipid was identified in the serum of an affected kitten, a carrier cat and a related unaffected kitten. This substance was produced by the liver of affected kittens and also by macrophage-like cells in spleen cell cultures prepared from the spleen of a kitten with signs of the disease.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.University of Pretoria

Photosensitivity in South Africa. VI. The experimental induction of geeldikkop in sheep with crude steroidal saponins from Tribulus terrestris

Geeldikkop was induced in sheep by the oral administration of crude steroidal saponins from Tribulus terrestris. Two of the sheep developed typical lesions of geeldikkop, including birefringent crystalloid material in bile ducts and concentric periductal lamellar fibrosis. The clinical pathological changes in these sheep were also consistent with those of geeldikkop: aspartate transaminase and gamma-glutamyl transferase activities in the sera of both were elevated, and one had bilirubinaemia. A third sheep became photosensitive without typical lesions of geeldikkop in the liver or changes in the activities of liver enzymes before euthanasia. The findings of these trials are consistent with reports from abroad that ovine hepatogenous photosensitization, caused by Agave lechuguilla and Narthecium ossifragum,can be induced with crude saponins from the respective plants.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201