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Biomedical subjects

M J Dillon

Publications and source records attributed to M J Dillon.

At least 181 records · Page 10Linked to original sources
PubMed1983

Inhibitor of prostacyclin production in sporadic haemolytic uraemic syndrome.

Prostacyclin (PGI2) production was diminished when rat aortic rings were incubated with plasma from 5 of 6 patients with the sporadic form of haemolytic uraemic syndrome but was normal in the presence of plasma from 7 patients with the epidemic form of haemolytic uraemic syndrome or from patients with other renal diseases. The reduced PGI2 production was caused by an unstable inhibitor, extractable into polar lipid solvents, in sporadic haemolytic uraemic plasma. These results suggest that there may be at least 2 different pathogenetic mechanisms in epidemic and sporadic haemolytic uraemic syndrome and that the reduced PGI2 production observed in the sporadic type is due to an inhibitor of PGI2 production rather than a deficiency of stimulating factors.

Adolescent↗
PubMed1983

Renal function following cardiopulmonary bypass surgery in children: a randomized comparison of the effects of gentamicin and cloxacillin with cephalothin.

Renal function was studied in 36 children who were randomly allocated to receive either gentamicin and cloxacillin or cephalothin as prophylactic antibiotic cover for complex cardiopulmonary bypass surgery. Both groups of children developed a similar degree of impairment of glomerular function with significant elevations in plasma creatinine concentrations and urine albumin excretion compared to preoperative levels which tended to resolve by the 5th postoperative day. The urine excretion of N-acetyl-glucosaminidase increased in both groups postoperatively but remained significantly elevated only in those children who had received gentamicin. These findings suggest that whilst gentamicin exerts a demonstrable nephrotoxic effect on the proximal renal tubules it does not contribute significantly to either the incidence or severity of postoperative renal glomerular impairment.

Acute Kidney Injury↗
PubMed1983

Survival time in cystinosis. A collaborative study.

In a retrospective study the overall survival time of 205 cystinotic patients of six countries was determined. The median survival time was 8.5 years. The median time for 'renal death' (age at death due to uraemia or age at starting renal replacement therapy) was 9.2 years. The youngest patient dying of renal death was 5.2 years. No sex difference in survival time was noticed. Furthermore no difference in survival time was noted between the different countries. The analysis of the overall survival curve indicates no clear differences between the infantile and adolescent types of cystinosis.

Adolescent↗
PubMed1982

Renal failure due to 2,8-dihydroxyadenine urolithiasis.

A four-year-old girl presented in renal failure due to dihydroxyadenine urolithiasis. Prior to this she had been fed a high purine macrobiotic diet, rich in pulses and grain. She was comatose, anuric, requiring peritoneal dialysis, and bilateral radiolucent renal calculi were revealed by ultrasonography and retrograde pyelography. 2,8-dihydroxyadenine stones were found at pyelolithotomy, renal biopsy revealed interstitial birefringent crystals, and a complete lack of adenine phosphoribosyl transferase (APRT) was found subsequently in erythrocyte lysates. APRT levels were initially falsely raised due to a blood transfusion on admission. The mother was shown to have heterozygote levels. The child was treated successfully with allopurinol, and a reduction in dietary purine but with only partial return of renal function.

Adenine↗
PubMed1982

Acute renal failure complicating cardiopulmonary bypass surgery.

Acute renal failure developed in 24 (5.3%) of 456 children undergoing cardiopulmonary bypass surgery during a 2-year period. It was more common in younger children, in those with complex cardiac lesions, and in those with long overall bypass times. Fourteen (58%) recovered renal function; renal failure was responsible for death in only two. Early vigorous peritoneal dialysis is advocated after cardiopulmonary bypass surgery if there is oliguria (less than or equal to 1.0 ml urine/kg per hour) resistant to volume repletion, dopamine infusion and diuretics, intractable fluid overload, or hyperkalaemia.

Acute Kidney Injury↗
PubMed1982

Analysis of steroids in urine for differentiation of pseudohypoaldosteronism and aldosterone biosynthetic defect.

The salt-losing syndromes in the neonatal period and early infancy due to adrenal disease can be differentiated by the pattern of excretion of steroids in urine. The presence or absence of metabolites of cortisol, aldosterone, and corticosterone as well as certain precursors can be established in a single analysis of steroids in urine by using gas chromatography with open tubular capillary columns. The profiles of steroid excretion in the urine of 8 infants with renal tubular insensitivity to aldosterone were compared with those in 5 infants with isolated aldosterone biosynthetic defects. The excretion in urine of 18 hydroxytetrahydro-compound A was elevated in all 13 children, but relative to the excretion of tetrahydroaldosterone, a high ratio was found for the biosynthetic defect and clearly distinguished the 2 conditions. Age-related changes in steroid metabolism are described. The diagnosis in each case was supported by clinical investigation together with determinations of PRA and aldosterone concentrations.

Aldosterone↗
PubMed1981

Uric acid crystal-induced nephropathy: evidence for a specific renal lesion in a gouty family.

Gout is principally a disease of middle-aged men. There has been a lot of discussion over the cause of the renal lesion, whether it is age, hypertension or crystal induced, as single factors or in combination. We have recently been able to study renal biopsies from three related young women with an hereditary gout, and another girl with 2,8-dihydroxyadenine crystal nephropathy. All were normotensive. These findings were compared with the findings of a crystal-induced nephropathy in pigs. In the renal biopsies many stages of acute and chronic nephritis were found which were similar to the crystal nephropathy in pigs. We concluded that the cause of the original lesion in the women was crystal deposition in the tubules, that crystals were not necessary to keep a non-specific nephritis active and that age and hypertension need not be contributory factors.

Adenine↗
PubMed1980

Renin-angiotensin-aldosterone system.

There is increased activity of the renin, angiotensin, aldosterone (RAA) system in infancy and childhood. An inverse relationship between plasma renin, aldosterone and age has been demonstrated. In childhood hypertension due to renovascular disease or pyelonephritic scarring peripheral plasma renin is increased. Renal vein renin measurements in children with renal hypertension have proved valuable in predicting surgical curability of the underlying lesion. The upper limit of normal for the renal venous renin ratio in normotensive children without renal disease is 1.5. Pharmacological blockade of the RAA system has a place in diagnosis and treatment of hypertensive children. The plasma renin aldosterone profile is diagnostically useful in the investigation of salt-wasting disease and can easily distinguish between aldosterone biosynthetic defects and pseudohypoaldosteronism.

Aging↗
PubMed1980

Pseudohypoaldosteronism.

10 infants are described with pseudohypoaldosteronism, 5 in detail and a further 5 briefly. They all presented with hyperkalaemia, urinary salt-wasting disease, and ostensibly normal renal and adrenocortical function. Diagnosis was established by demonstrating the greatly increased values of plasma renin activity and plasma aldosterone concentration, plus the increased excretion of aldosterone and its metabolites on gas chromatographic and mass spectrometric analyses of urine. The children were treated with sodium chloride supplements, up to 60 mmol/day, but by the time most of the infants were about a year old these could be stopped. Exogenous mineralocorticoids were without effect in those to whom they were administered. The precise aetiology of the condition remains conjectural; lack of renal tubular response to aldosterone seems probable. Pseudohypoaldosteronism may be more common than has been thought and new techniques for investigating salt-wasting disorders may show its true incidence.

Aldosterone↗
PubMed1980

Hypertension in a four-year-old child: gas chromatographic and mass spectrometric evidence for deficient hepatic metabolism of steroids.

A 4-yr-old boy with hypertension and hypokalaemic alkalosis had low plasma aldosterone levels and renin activity. The hypertension and hypokalemia responded to spironolactone and triamterene therapy. A partial response to dexamethasone was observed. Analysis of urinary steroid metabolites by gas chromatography-mass spectrometry showed that the excretion of metabolites of deoxycorticosterone and aldosterone was subnormal, and there was no evidence for sizeable excretion of unusual steroids with potential mineralocorticoid activity. The cortisol excretion rate, however, was subnormal, and the relative excretions of individual metabolites of this hormone were not typical. In particular, the excretion of tetrahydrocortisone was markedly reduced, and the excretions of allotetrahydrocortisol and free cortisol and metabolites were elevated. These findings suggest that modified or deficient metabolism of adrenal steroids could give rise to elevated blood pressure. It is not known whether the inappropriate production of unusual cortisol metabolites were responsbile for the high blood pressure or whether the altered metabolism is indicative of similar abnormality in the metabolism of other adrenal steroids, resulting in hyperproduction or extended half-life of minor but highly active mineralocorticoids of unknown structures.

Aldosterone↗
PubMed1979

Blindness and paraplegia in severe childhood hypertension.

3 children with severe renal hypertension and bilateral infarction of the optic nerves are described. 1 patient also had a transverse myelopathy. Such complications may perhaps be prevented by earlier detection of hypertension and gradual reduction of blood-pressure.

Age Factors↗
PubMed1979

Malnutrition in infants receiving cult diets: a form of child abuse.

Severe nutritional disorders, including kwashiorkor, marasmus, and rickets, were seen in four children and were due to parental food faddism, which should perhaps be regarded as a form of child abuse. All disorders were corrected with more normal diets and vitamin supplements. In view of the potentially serious consequences of restricted diets being fed to children, families at risk should be identified and acceptable nutritional advice given. When children are found to be suffering from undernutrition due to parental food faddism a court order will normally be a necessary step in providing adequate treatment and supervision.

Child Abuse↗
PubMed1979

Renal vein renin measurements in normotensive children.

Renal venous PRA was measured in 49 normotensive children without renal disease undergoing routine cardiac catheterization. PRA levels did not differ significantly between both renal veins and were significantly higher in the renal veins than in the IVC. There was a constant mean ratio of 1.21 between the renal veins and the IVC at low, intermediate, and high absolute PRA levels. Three patients had a renal venous PRA ratio greater than 1.4 and the highest ratio observed was 1.55. This fidning supports 1.5 as an acceptable upper limit of normality for the interpretation of renal vein PRA ratios in the investigation of patients with suspected renal hypertension. In four patients, PRA in the renal veins was significantly lower than in the IVC. The possibility of renin removal by these kidneys is discussed.

Adolescent↗
PubMed1979

Clinical evaluation and comparison of the Infrasonde, Arteriosonde, and mercury sphygmomanometer in measurement of blood pressure in children.

Both systolic and diastolic pressures can be measured in children with the mercury sphygmomanometer, the Arteriosonde and the Infrasonde. Estimates made blindly with these instruments were compared with directly measured intra-arterial blood pressures in 50 children aged between 4 days and 14 years. Systolic and diastolic estimates with the three techniques showed highly significant correlations with simultaneous intra-arterial measurements (P less than 0.001). The Infrasonde diastolic estimates were least satisfactory and the slope of the regression line against the intra-arterial pressure differed significantly from unity (y=0.54x+29.53). In 11 small children a satisfactory diastolic estimate could not be obtained with the mercury sphygmomanometer. While the mercury sphygmomanometer should remain the standard hospital equipment, an Arteriosonde would be valuable if it is difficult to hear Korotkoff's sounds on auscultation and if a diastolic pressure is required. For research investigations into childhood blood pressure an Arteriosonde or mercury sphygmomanometer, coupled with a device to exclude observer bias, is probably most suitable. Although the Infrasonde is not sufficiently accurate for research purposes, it is acceptable for routine ward use.

Adolescent↗
PubMed1979

Bartter's syndrome: 10 cases in childhood. Results of long-term indomethacin therapy.

Ten children with Bartter's syndrome are described. Their ages at diagnosis ranged from three months to 15 years and there was an equal sex distribution. A wide spectrum of severity of clinical and biochemical features was found. Hypercalcaemia, hypophosphataemia, hypercalcuria, nephrocalcinosis, rickets and urine acidification defects were seen in some patients. Two affected children were siblings. Six children were treated over periods of six to 24 months with indomethacin with remarkable clinical and biochemical improvement. Catch-up growth was demonstrated in all treated cases. Tolerance to indomethacin appeared to develop in some children. Only one serious complication was seen with this therapy, a duodenal ulcer in a child on high dosage. Of those children not treated with indomethacin, one died, one is now on indomethacin elsewhere and two are well without therapy.

Adolescent↗