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Biomedical subjects

M J Dillon

Publications and source records attributed to M J Dillon.

At least 199 records · Page 11Linked to original sources
PubMed1978

Renin and blood-pressure in children with renal scarring and vesicoureteric reflux.

Plasma-renin-activity (P.R.A.) was raised in 9 of 15 hypertensive children with pyelonephritic scarring secondary to urinary-tract infection and vesicoureteric reflux and also in 8 of 100 normotensive children with such scars. P.R.A. was much less likely to fall with age in normotensive children with renal scarring than in normal children. The identification of hyperreninaemic normotensive children with renal scarring is important, since P.R.A. may prove to be of value in early identification of children at risk of developing hypertension. A longitudinal follow-up is proposed to establish this hypothesis.

Adolescent↗
PubMed1978

Renal vein renin measurements in children with hypertension.

Renal venous renin activity was measured in 50 children with hypertension. Main renal vein and segmental renal vein sampling was feasible in children as young as 15 months. In all cases in which there was a clear difference in renin secretion between the kidneys--that is, a main vein renin ratio above 1.5--surgery, when undertaken, successfully restored normal blood pressure. Most of the children with main renal vein renin ratios below 1.5 had bilateral disease or apparently normal kidneys. Segmental renal vein sampling contributed useful information additional to that provided by main renal vein measurements and permitted identification of local sources of renin production. In children with renal transplants who developed hypertension renal vein renin measurements helped in determining the cause and facilitating the management of the raised blood pressure.

Adolescent↗
PubMed1978

Renin and aldosterone response in human newborns to acute change in blood volume.

Increased activity of the renin/aldosterone system in the neonatal period is now well established in both animals and man but the control mechanisms are poorly understood. We have monitored the plasma renin activity (PRA) and plasma aldosterone concentration (PAldo) in 14 infants undergoing 21 exchange transfusions. PRA and PAldo were measured before and at 5, 10, 15, 30, 45, and 60 minutes after the injection, and 5, 10, 15, and 30 minutes after the withdrawal of 7 ml blood/kg birthweight immediately before exchange transfusions. PRA increased to a maximum of 53% and decreased to a maximum of 39% of the resting values after withdrawal or injection of blood respectively. PAldo values did not change significantly during the same period. Thus the renin-angiotensin system in the newborn infant is responsive to changes in blood volume.

Aldosterone↗
PubMed1978

'Epidemic neuromyasthenia' at the Hospital for Sick Children, Great Ormond Street, London.

An outbreak of an illness with features in common with 'epidemic neuromyasthenia' affected the staff of the Hospital for Sick Children in London between August 1970 and January 1971. At least 145 cases were observed and the majority of these were nurses. Symptomatology was protean, clinical findings minimal and relapses frequent. Care was taken to minimize anxiety and fear in a vulnerable population, and laboratory investigations were purposefully limited in number for this reason. In general, laboratory findings, including virological investigations were negative. A high incidence of anti-complementary activity and the presence of ill defined aggregates in some acute sera on electron microscopy were interesting and possibly significant findings suggesting the presence of immune complexes. These findings, plus the ability of lymphocytes from some patients to proliferate in vitro, were thought to represent possible evidence of an infective process. Although no children were affected during the 1970 outbreak, it is interesting that seven children have recently been referred to the hospital with features compatible with 'epidemic neuromyasthenia'.

Adolescent↗
PubMed1977

Congenital adrenal hyperplasia: renin and steroid values during treatment.

Plasma renin activity (PRA), aldosterone (Aldo), 17alpha-hydroxyprogesterone (17-OHP) and testosterone (T), together with urine sodium, pregnanetriol, 17-oxosteroids and the 11-oxygenation index (11-OH) were estimated in 23 patients (age 5.7--18 yrs.) with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency during glucocorticoid treatment. Elevated PRA levels (1400--17200 ng Al/l/hr) were found in 13 out of 15 patients with a history of salt loss. Three non-salt losers showed high PRA levels and in the remaining 5 the levels were in the upper normal range (540--900 ng Al/l/hr). Plasma Aldo levels were normal (25--620 pmol/l) in 18 patients and slightly elevated (690--2360 pmol/l) in 5. While these results indicate persistent impairment of sodium homeostasis in CAH patients, no significant correlations between log. PRA, log. Aldo and urinary sodium excretion were found. Mid-day 17-OHP levels ranged from 9 to 117 nmol/l and T from 0.3 to 18.0 nmol/l. Neither the 17-OHP nor the T results correlated well with the clinical assessment of therapeutic control. The results of the urinary steroid determinations showed better agreement with the clinical assessment of treatment and the 17-oxosteroid, pregnanetriol and 11-OH index results appeared to be better discriminants between good and poor control. Twelve of the patients with a history of early salt loss were reinvestigated after one month's treatment with oral 9 alpha-flurohydrocortisone (0.05 mg/day). PRA was reduced in 7 patients and 17-OHP fell in 10 patients. No consistent changes were found in Aldo, T, or urinary sodium and steroid excretion during this low-dose mineralocorticoid treatment.

17-Ketosteroids↗
PubMed1977

Salt-losing syndrome in 2 infants with defective 18-dehydrogenation in aldosterone biosynthesis.

Two infants presented with a salt-losing syndrome, the presenting features of which were subtle. One case appeared to be transient. Deficient production of aldosterone was shown by plasma renin activity and plasma aldosterone profile. Gas chromatography-mass spectrometry of urine indicated a defect in 18-dehydrogenation of 18-hydroxycorticosterone. Treatment with salt supplements and 9alpha-fludrocortisone reversed the salt-losing state and in one case treatment was later stopped. Although the disease may appear transient, the biochemical defect is persistent and for adequate growth a positive salt-balance is necessary.

18-Hydroxycorticosterone↗
PubMed1976

Plasma renin activity and aldosterone concentration in the human newborn.

Twenty-one healthy newborn infants whose mothers had normal pregnancies and deliveries were studied. Plasma renin activity (PRA) and plasma aldosterone concentration (PAldo) were measured by semimicro methods in cord blood and on the 6th day of life. PRA and PAldo were increased in cord blood compared with values previously found in healthy infants between 1 month and 1 year of age. There was a twofold reduction in both values by the 6th day. PRA and PAldo were positively correlated when cord blood and 6th-day values were considered as a whole, but no significant correlations were found between either cord blood PRA or cord blood PAldo and their respective values on the 6th day. The PRA and PAldo findings were not related to birthweight, the infant's sex, weight change, 6th-day urinary sodium, or blood pressure measurements. The type of milk feed did not influence PRA but PAldo was slightly greater in bottle-fed babies on the 6 day. These observations confirmed that the inverse relationship between PRA, PAldo, and age extends into the neonatal period but they suggest that the balance of factors controlling these variables at birth is different to that operating at the age of 6 days.

Age Factors↗
PubMed1976

Cry fire!

Explore the source record for details and available documents.

Fires↗
PubMed1975

Plasma renin activity and aldosterone concentration in children.

Using semi-micro methods, plasma renin activity (PRA) and plasma aldosterone concentration (PA) were measured concurrently in 79 healthy children aged 1 month to 15 years to establish a reference range. PRA and PA varied inversely with age. Eleven children with renal hypertension had higher PRA and PA than age-matched controls. In contrast, PRA was much greater in 38 saline-depleted children. PA was not uniformly increased in this group and was within the normal range in children with adrenal diseases compared with the high values seen in other salt-wasting states. The findings emphasise the need to relate data from patients to age-matched control values before attempting interpretation and suggest that sodium depletion is a more potent stimulator of renin-aldosterone release than renovascular disease or renal scarring in children. Plasma renin-aldosterone profiles were also valuable in discriminating between renal and adrenal causes of salt loss in childhood.

Adolescent↗
PubMed1975

Micropenis associated with testicular agenesis.

This paper describes 2 male infants who were born with sever micropenis and in whom testicular tissue could not be identified at surgery. HCG stimulation in one infant was not followed by a rise in plasma testosterone. It was decided that both cases would be best raised as females, despite their male chromosomal sex.

Chorionic Gonadotropin↗
PubMed1975

Hypertension, oedema, and suppressed renin aldosterone system due to unsupervised salt administration.

This paper describes an infant with gastroenteritis, who developed hypertension and oedema after administration of inaccurately prepared oral glucose salt solution. The renin aldosterone system was suppressed in this child and it was suggested that this may be a factor in the development of hypernatraemia when abnormal water losses occur in infants fed on hyperosmolar feeds. Unless salt can be given accurately in small amounts it may be safer to advise feeds of glucose only in infants with mild diarrhoea.

Aldosterone↗
PubMed1975

Measurement of plasma renin activity by semi-micro radioimmunoassay of generated angiotensin I.

A semi-micro method for determination of plasma renin activity (PRA) by radioimmunoassay of generated angiotensin I (AI) is described. The method permits measurement of PRA on 250 mul of plasma without loss of specificity, sensitivity, accuracy or preision. The small sample size has considerable application in terms of investigation of infants and young children. A reference range was established for healthy children on free diets. There was a 15-fold decline in PRA with age from a mean value of 1404pgAI/ml h-1 (ngAI/1. h-1) in infancy to a mean of 85 pgAI/ml h-1 (ngAI/1. h-1) in adult life.

Adolescent↗
PubMed1974

Epidemic neuromyasthenia: outbreak among nurses at a children's hospital.

Between August 1970 and January 1971 nearly 150 of the staff of a London teaching hospital were affected by an illness with features in common with what is currently known as epidemic neuromyasthenia. Symptomatology was protean, clinical findings minimal, relapses frequent, and results of laboratory investigations, including virological studies, were generally negative. Most of the patients were nurses. Care was taken to minimize anxiety and fear in a vulnerable population, and laboratory investigations were limited in number for this reason.

Blood Chemical Analysis↗