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Biomedical subjects

R B Elliott

Publications and source records attributed to R B Elliott.

At least 109 records · Page 6Linked to original sources
PubMed1978

The effects of some methyl prostaglandin derivatives on the ductus arteriosus of swine in vivo.

Three methylated analogues of prostaglandin E1 and E2 were examined for their ability to open the ductus arterious of neonatal piglets in vivo. Fifteen (S) 15 methyl prostaglandin E1 (15-Me PGE1), 15 (S) 1K methyl prostaglandin E2 (15-Me PGE2), and 16' 16' dimethyl prostaglandin E1 (16-diMe PGE1) all opened the ductus when given intravenously, intramuscularly or orally. The effects on ductal patency lasted four hours or more in many instances. Side-effects included apnea with intravenous and intramuscular dosages, and with high oral dosages of 15-Me PGE1. A transient drop in heart rate and blood pressure occurred with each dose. In one animal the ductus was kept open for 19 days with six-hourly intramuscular injections of 3 microgram/kg 15-Me PGE1. Transient sedation occurred with each dose. Death occurred on the 19th day and histological studies showed that the morphology of the ductus wall was similar to that seen in a two day old animal. These studies suggest that maintenance od ductal patency in the infant may be possible with oral administration of methyl prostaglandin derivatives.

Administration, Oral↗
PubMed1978

Effect of prostaglandins and some methyl derivatives on the ductus arteriosus.

In vitro studies showed that PGF2a constricted the ductus arteriosus of newborn animals, whereas PGEs produced dilatation. The finding that constriction could also be produced by c-GMP and dilatation by c-AMP raised the possibility that the PGs might produce their effects by altering the relative proportions of cyclic nucleotides in the ductus wall. Results of experiments with inhibitors of PG synthesis and with drugs which are known to interfere with the degradation of c-GMP and c-AMP accorded with this hypothesis. Angiographic studies in neonatal piglets showed that PGEs and PGAs were potent dilators of the ductus. Prostaglandin action was confirmed in infants with congenital heart disease who were dependent on ductus patency for survival. In those patients, PGs proved to be an extremely useful tool. Experimental studies are in progress in the hope of finding a PGE analog, active by the oral route, which may be suitable for the long-term treatment of patients.

Animals↗
PubMed1977

Cystic-fibrosis screening in the newborn.

In a new method of testing stool samples from newborn babies for cystic fibrosis (C.F.), a colourless substrate, benzoyl-arginine-p-nitroanilide (B.A.P.N.A.), releases yellow p-nitroaniline when hydrolysed by trypsin. Samples from infants with C.F., who lack trypsin, give negligible colour. 2 infants with C.F. were detected among 2500 consecutive newborn babies tested. The incidence of false-positive results was 1.2% after the first specimen and 0.05% after the second specimen. A further refinement has reduced the positive rate to 0.1% after the first specimen (2000 samples). Tests on samples from 5 other older patients with untreated C.F. have yielded no evidence for false-negative results.

Benzoylarginine Nitroanilide↗
PubMed1977

Palliation of cyanotic congenital heart disease in infancy with E-type prostaglandins.

Prostaglandin-E (PGE) infusions have been used in an attempt to increase ductal patency in 11 infants aged one to 99 days with cyanotic heart disease. PGE1 was used in nine infants and PGE2 in two. Five patients had pulmonary atresia, four extreme pulmonary stenosis, one Ebstein's anomaly and one simple transposition of the great arteries. All but the oldest infant showed a satisfactory increase in oxygen saturation (average 36%) attributed to dilatation of the ductus. The failure in one infant may have been due largely to hypoplasia of the left pulmonary artery. The only important side effect was apnea in one infant receiving PGE2. The efficacy of this form of treatment is confirmed in infants dependent on ductal patency for survival. PGE is an important asset in saving the lives of neonates requiring an aorticopulmonary shunt operation. The recommended starting dose is 0.1 mug/kg/min of PGE1 given by constant infusion.

Heart Defects, Congenital↗
PubMed1976

Cystic fibrosis in New Zealand: incidence and mortality data.

The incidence of and mortality from cystic fibrosis in New Zealand for the years 1965-1971 have been reviewed. Data were obtained from hospital admission and death records. All of the 171 cases were of European parentage except for one part-Maori child. The minimum incidence of cystic fibrosis in the European population (one in 3185 live births) is comparable with that in other populations of similar background but somewhat lower than that derived by Becroft (1968). The data show that, during the period of the survey, approximately 30 percent of cystic fibrosis suffereres died at less than 12 months of age.

Child↗
PubMed1976

Studies in the renal handling of insulin in juvenile diabetics.

A technique is described for the accurate radioimmunoassay of insulin in serum and urine. This method was applied to study of renal clearance and excretion of endogenous and exogenous insulin in untreated juvenile diabetics and healthy young adults. There was good agreement between our results for normal adults and previously reported values. In six non-obese juvenile diabetics, urinary insulin clearance values, both basal (fasting) and following glucose loading (entire range 0.03 ml/min to 1.23 ml/min) were similar to those obtained for the adults (entire range 0.17 ml/min to 2.35 ml/min). The basal urinary excretion in these diabetics was generally of the same order of magnitude as that in the normals. The clearance of exogenous insulin, administered for the first time, was also of the same order as that for endogenous insulin. Markedly elevated urinary clearance and excretion of insulin during fasting and non-fasting states was demonstrated in four non-obese juvenile diabetics with no clinical evidence of abnormal proteinuria, though they demonstrated slight to mild clinical dehydration and acidosis compared with the other diabetics studied. Clearance and excretion of exogenous insulin was similarly elevated. This finding could reflect renal tubular dysfunction in these diabetics, and this dysfunction could relate to even the mild degree of dehydration and acidosis found in this study. Endogenous and exogenous insulin clearance in an obese diabetic child was similar to that for the control group.

Child↗
PubMed1976

Studies on the effects of prostaglandins E1, E2, A1, and A2 on the dustus arteriosus of swine in vivo using cineangiography.

Prostaglandins E1, E2, A1, and A2 have been shown by cineaortography to open and dilate the ductus arteriosus in anesthetised piglets 3 to 6 hours of age. The dosage of PGEs required was 1 to 4 mug/kg/min. and of PGAs 20 to 40 mug/kg/min. The effect of PGEs faded within 20 minutes of stopping infusion but the effect of PGAs was still evident up to 45 minutes after stopping the infusion. Little effect was noted from hypoxia or from the addition of indomethacin to prostaglandin infusion. Side effects were not troublesome with the dosage employed but hypotension and apnea sometimes occurred at the onset of PGE infusions.

Animals↗
PubMed1976

A therapeutic trial of fatty acid supplementation in cystic fibrosis.

Seven children with cystic fibrosis (CF) have been treated for at least one year with intravenously administered soya oil emulsion. In all, an improvement of at least one biochemical abnormality in character with the disease appeared. The children's clinical course remains benign. This course is remarkably better than that of other children with CF treated without Intralipid in Auckland in the same period, though a placebo effect cannot be discounted. It is postulated that intravenous supplementation with essential fatty acid in CF may in turn partially correct an error of metabolism of prostaglandins present in the disease.

Body Weight↗
PubMed1975

A comparative study of the health of elite Maori and Caucasian children in Auckland.

A group of socially elite Maori and part-Maori parents kept a 10 month record (February to November 1972) of their children's health. The majority of a Caucasian control group were matched for socio-economic status by the Maori parents. The majority of both parent groups were of professional or skilled tradesman status whose income exceeded the then current New Zealand average. The results show no overall difference between the morbidity of the two racial groups studied.

Child↗
PubMed1975

Medical manipulation of the ductus arteriosus.

Prostaglandin E-1 was infused into two children with cyanotic congenital heart-disease where patency of the ductus arteriosus was necessary to maintain arterial oxygen saturation. With each infusion oxygen saturation rose, probably as a result of dilatation of the ductus. Administration of the non-specific antagonist of prostaglandin synthesis, indomethacin, to one patient was associated with a fall in arterial saturation. The prevention of ductus closure by p.g.E-1 infusions over the first few weeks of life is a possiblility.

Blood Pressure↗