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Biomedical subjects

R D Milner

Publications and source records attributed to R D Milner.

At least 163 records · Page 9Linked to original sources

Fat absorption by small babies fed two filled milk formulae.

In 3-day fat balances, 7 of 8 infants had appreciably more steatorrhoea when they were fed Cow and Gate V formula than when they were fed SMA. The mean fat excretion (+/- SEM) expressed as a percentage of the amount ingested on Cow and Gate V was 28-1 +/- 3-9 compared with 10-5 +/- 2-3 on SMA. Gas-liquid chromatography of the faecal fat in 2 of 3 infants showed that C16:0 was responsible for most of the excess fatty acid when they were fed Cow and Gate V formula.

Animals↗

Effect of decapitation and ACTH on somatic development of the rabbit fetus.

Rabbit fetuses were decapitated, injected with ACTH or decapitated and injected with ACTH on day 24 of gestation. On day 29 the body weight and weight of the interscapular fat pad were compared with those of littermates. The weight, total DNA and weight/DNA ratio of the liver, heart and kidney were measured in experimental and control fetuses. A comparison was made between decapitated and control fetuses of the length of the hind limb bones and number of ossified vertebrae. The body weight of the decapitated or ACTH-injected fetus ranked significantly below the mean for the litter, but decapitated fetuses injected with ACTH ranked close to the litter mean. The growth retardation of the decapitated fetus was not manifest in the kidneys which were heavier and had a greater number of cells than normal, nor in the cell size of the heart, liver or kidneys which were equal to those of the heaviest fetus in the litter. Decapitation had no specific effect on ossification. Growth retardation of the ACTH-injected fetus was mirrored by different patterns of DNA and weight/DNA reduction in the three organs studied. Decapitation retards growth in body weight of the fetal rabbit which may be corrected by ACTH. It is concluded that the hypophyseal-adrenal axis plays a role in the control of normal fetal growth but that excess secretion of glucocorticoids results in stunting.

Adrenocorticotropic Hormone↗

Metabolic and hormonal consequences of exchange transfusion via the umbilical artery or vein.

Twenty exchange transfusions for hyperbilirubinaemia were performed via the umbilical vein or artery in 17 term and pre-term infants. Blood preserved with acid citrate and dextrose was used and the effect of the route of transfusion on plasma glucose, free fatty acid, insulin and growth hormone (GH) concentrations was measured during the transfusion and for 3 h afterwards. Infants transfused via the umbilical vein secreted more insulin than those transfused via the artery although both groups had similar rises in plasma glucose. After transfusion, glucose disappearance was faster and minimum plasma glucose levels were lower in infants transfused via the vein. This group had a smaller fall in plasma free fatty acids during transfusion, but otherwise plasma free fatty acid levels were similar in both groups. More GH was secreted by infants transfused via the artery resulting in higher plasma levels during and after transfusion.

Blood Glucose↗

Development of pathways of insulin secretion in the rabbit.

Insulin release was studied in vitro using pieces of pancreas from rabbits of between 24 days gestational age and 6 weeks postnatal age. When allowance was made for the fraction of pancreas which was endocrine, 16-5mM-glucose caused increasing stimulation of insulin release as development advanced and 3-3 mM-glucose caused a similar rate of secretion at all ages. Secretion was not significantly influenced by insulin destruction in the incubation medium. Glucagon (5 mug/ml) did not stimulate insulin secretion from 24-day foetal pancreas but did so postnatally. Theophylline (1 mmol/1) stimulated insulin release at all ages and was equipotent on 24-day foetal pancreas in 3-3 or 16-5 mM-glucose. The stimulation of insulin release from 24-day foetal pancreas by 1 mM-theophylline occurred in the absence of extracellular glucose, pyruvate, fumarate and glutamate and in the presence of mannoheptulose and 2-deoxyglucose (each 3 mg/ml). Adrenaline (1 mumol/1) and diazoxide (250 mug/ml) abolished or attenuated the stimulation of insulin release by glucose, leucine plus arginine or theophylline from 24-day foetal, 1 day and 6 weeks postnatal pancreas. The stimulation of insulin release from 6-week-old pancreas by 1mM-barium was blocked by adrenaline and diazoxide but the effect became less with increasing immaturity. The experimental results illustrate some of the ways in which insulin secretion by the rabbit beta cell changes as a function of development and draw attention to the importance of glucose and cyclic adenosine monophosphate in this process.

Age Factors↗

Spontaneous changes in growth hormone and insulin levels in newborn infants.

Ten term, normally grown newborn infants aged 3-5 days with hyperbilirubinaemia due to rhesus or ABO incompatibility have been studied. Blood samples were taken via an umbilical venous catheter at 10 minute intervals in order to study spontaneous changes in growth hormone, insulin, glucose and free fatty acid concentration. Mean plasma GH, insulin and glucose concentrations remained unchanged, but the FFA level rose, due probably to the low room temperature at which the investigations were performed. Analysis of individual changes showed large and bidirectional alterations in GH and insulin, which were much greater than the error of the analytical methods. The findings should be considered in the evaluation of diagnostic investigations performed on newborn infants.

Apgar Score↗

Adrenocorticotrophin and the development of insulin secretion in the rabbit foetus.

Foetal rabbits were injected with adrenocorticotrophin (ACTH), decapitated, or decapitated and injected simultaneously with ACTH or cortisol in utero on day 24 of gestation. The foetuses were killed after Caesarian section on day 29, and blood was collected for measurement of plasma insulin concentration and pancreatic tissue was obtained for incubation in physiological buffer. Insulin release from the pancreatic tissue of decapitated foetuses was significantly greater than that from the pancreas of control litter-mates when incubated in media containing 3-3mM-glucose, 16-5mM-glucose or 16-5mM-glucose plus 5 mug glucagon/ml, but was similar when the incubation medium contained 3-3 or 16-5 mM-glucose plus 1 mM-theophylline or 3-3mM-glucose plus 60 mM-potassium. The pancreata of decapitated or intact foetuses injected with ACTH did not differ significantly from control foetuses in terms of insulin release in response to glucose in vitro. The plasma insulin concentration of decapitated foetuses and decapitated foetuses injected with ACTH was raised, whereas that of intact foetuses injected with ACTH was similar to that of the control foetuses. Cortisol injection at the time of decapitation resulted in a high rate of foetal mortality. The results indicate that foetal ACTH or foetal adrenocortical secretion influences the normal development of glucose-mediated insulin secretion in the rabbit and that exogenous ACTH corrects the effect of decapitation on beta cell function in vitro but not on plasma insulin concentration.

Adrenocorticotropic Hormone↗