Biomedical subjects
A Faulkner
Publications and source records attributed to A Faulkner.
L-Lactate as a source of carbon for fatty acid synthesis in adult and foetal sheep.
The contribution of carbon from acetate, glucose and L-lactate to fatty acid synthesis has been compared in adipose tissue from adult and foetal sheep. Adipose tissue slices were incubated with mixtures of acetate, glucose and L-lactate at concentrations found in sheep blood. Under these conditions acetate, glucose and L-lactate contributed 95, 2 and 3%, respectively, of the C2 units used for fatty acid synthesis in adipose tissue slices from adult sheep. In contrast, acetate, glucose and L-acetate provided 50, 17 and 33%, respectively, of the C2 units for fatty acid synthesis in adipose tissue slices from foetal lambs (about 30 days prior to birth). The contribution of acetate and L-lactate carbon to fatty acid synthesis varied with their concentrations over the normal physiological range at both ages. We conclude that L-lactate is normally a minor source of carbon for fatty acid synthesis in the adult sheep but is an important source in foetal lambs.
Communication skills. Talking points 15.
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Aye, there's the rub. Communication skills.
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Metabolic significance of milk glucose.
The free glucose concentration in the aqueous phase of samples of goat, sheep, cow, rat and rabbit milk was about 0.1-0.3 mM, while that in human milk was about 2mM. During starvation the glucose concentration of goat milk fell considerably (by about 80% in 2 d) in parallel with the decreased rate of lactose production. With rats fed ad lib., glucose concentration in the milk was greater at 12.00 h than at 18.00 h, when lactose synthesis has been shown to decrease. 3-O-Methyl-D-glucose injected into the goat mammary gland via the teat canal specifically entered the blood. These findings support the idea that glucose equilibrates across the apical membrane of mammary secretory cells, so that milk concentrations reflect intracellular glucose concentratioins.
Changes in milk citrate concentration during lactation in the goat.
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Changes in the concentrations of the minor constituents of goat's milk during starvation and on refeeding of the lactating animal and their relationship to mammary gland metabolism.
1. Changes in the concentrations of the minor constituents of goat's milk were observed during 48 h starvation and on refeeding. 2. The concentrations of hexose phosphate and UDP-hexoses increased during starvation and decreased on refeeding. 3. The concentrations of phosphoenolpyruvate and glycerate 3-phosphate decreased during starvation and increased on refeeding. 4. Isocitrate:2-oxoglutarate increased during starvation and decreased on refeeding. 5. Changes in the minor constituents of milk can be explained in terms of the metabolic changes occurring in the mammary gland during starvation. It is proposed that changes in the concentrations of these metabolites in milk reflect changes in their concentrations in the cytosol or Golgi vesicles of the mammary gland.
Counselling patients with cancer.
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Pyruvate dehydrogenase and the regulation of glucose metabolism in ruminant tissues.
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Communication and the nurse.
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The presence of cellular metabolites in milk.
Cellular metabolites are present in goats' milk. The concentrations of UDPgalactose and some nucleotides were higher in milk than in mammary tissue. Other metabolites were present in milk at similar concentrations to those found in the mammary gland. It is proposed that the concentrations of these metabolites in milk reflect their Golgi-vesicular and cytosolic concentrations.
The utilization of glucose for the synthesis of milk components in the fed and starved lactating goat in vivo.
1. [U-14C]Glucose and [3-3H]glucose were infused into fed and starved lactating goats in order to study glucose metabolism in the mammary gland. 2. Glucose carbon was oxidized and metabolizet to milk lactose, citrate and triacylglycerol in the lactating goat udder. 3. Recycling of glucose carbon in the lactating animal accounted for 10-20% of the total glucose turnover in the whole animal. Recycling of glucose 6-phosphate in the udder accounted for about 25% of the glucose 6-phosphate metabolized. 4. Flux of glucose 6-phosphate through the pentose phosphate pathway was sufficient to account for 34% of the NADPH required for fatty acid synthesis in the gland in the fed animal. 5. Net metabolism of glucose 6-phosphate via the pentose phosphate pathway accounted for 17.8 and 1.2% of the glucose phosphorylated by the mammary gland in the fed and starved animal respectively. Metabolism of glucose 6-phosphate via the pentose phosphate pathway was sufficient to account for all the CO2 produced from glucose in the fed animal, but only 17% of the CO2 produced from glucose in the starved animal.
Renal gluconeogenesis in pregnant and non-pregnant sheep.
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Cold exposure and mammary glucose metabolism in the lactating goat.
1. [U-14C]glucose was infused intravenously into conscious lactating goats exposed to thermoneutral or cold environments for a total of 24 h. The irreversible loss of glucose from the whole body and uptake of glucose by the mammary gland was measured and glucose utilization in the udder was studied by measuring the incorporation of radioactivity into carbon dioxide in mammary venous blood, into milk lactose and milk triglyceride-glycerol. 2. Exposure to cold increased the circulating level of glucose and slightly though not significantly, increased the non-mammary irreversible loss of glucose. 3. The extraction of glucose from the circulation by the udder fell, the secretion of lactose by the udder also fell and this correlated closely with the reduced secretion of milk in the cold. 4. Simultaneous measurements of the concentrations of insulin, growth hormone and corticosteroids in the arterial plasma were made. 5. The plasma concentration of corticosteroids increased significantly in the cold. 6. It is concluded that reduced glucose uptake and lactose synthesis by the udder are important factors which reduce milk secretion during cold exposure.
Effects of starvation on cardiovascular function (including the mammary circulation) and water balance in pregnant goats.
In conscious goats, starved for 48 hr, in mid-pregnancy (70 days) cardiac output and blood volume decreased; total peripheral resistance increased; heart rate, stroke volume, blood pressure, mammary blood flow and mammary resistance were not significantly affected. In late pregnancy (132 days) cardiac output, heart rate, blood volume and mammary blood flow fell; peripheral resistance increased; stroke volume and blood pressure were not significantly affected. In mid-pregnancy, water consumption fell and the animal entered a stage of negative sensible water balance which persisted for both days of starvation. A similar change was obtained on the first day in late-pregnant goats, but on the second day water consumption increased and positive water balance was restored. Cardiac output, heart rate, blood volume and mammary blood flow was higher in fed late-pregnant than in fed mid-pregnant goats, total peripheral resistance was lower while there were no significant changes in stroke volume or blood pressure. Indications of correlations between litter size and cardiac function were obtained. The results are compared with previous studies on the effects of starvation in lactating animals and are discussed in relation to the control of cardiac function and mammary blood flow in pregnancy and lactation.
Nursing as a research based profession - some ethical issues.
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Effects of starvation on the cardiovascular system, water balance and milk secretion in lactating goats.
During starvation in the lactating goat, cardiac output, stroke volume, mammary blood flow, blood volume and the rate of milk secretion decreased markedly; total peripheral resistance and haematocrit increased while arterial blood pressure and plasma osmolality remained unchanged. Water consumption decreased markedly and the animals went into negative water balance even though water was available throughout.
Monitoring nurse-patient conversation in a ward.
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