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J W Balfe

Publications and source records attributed to J W Balfe.

At least 19 recordsLinked to original sources
PubMed1992

Inherited WT1 mutation in Denys-Drash syndrome.

Patients with the Denys-Drash syndrome (Wilms' tumor, genital anomalies, and nephropathy) have been demonstrated to carry de novo constitutional mutations in WT1, the Wilms' tumor gene at chromosome 11p13. We report three new cases, two carrying a previously described WT1 exon 9 mutation and one with a novel WT1 exon 8 mutation. However, unlike patients in previous reports, one of our three patients inherited the affected allele from his phenotypically unaffected father. This observation indicates that the WT1 exon 9 mutation affecting 394Arg demonstrated in over one-half of the patients with the Denys-Drash syndrome may exhibit incomplete penetrance. Consequently, familial studies in patients affected by this syndrome are recommended.

Adolescent↗
PubMed1992

Captopril test in children with reflux nephropathy.

We studied the plasma renin activity (PRA) and blood pressure (BP) responses to a single oral dose of captopril in children with renal scarring due to vesicoureteral reflux. The test was performed on 19 children, of whom 13 were normotensive and 6 hypertensive. Basal PRA was within the normal range for age for all except 1 patient. Mean basal PRA values for normotensive and hypertensive patients were not significantly different. At 90 min post captopril, the mean PRA increase was 3.61 ng/l per second (SD = 7.07) in the normotensive group but only 0.77 ng/l per second (SD = 0.83) in the hypertensive group. In 11 patients the average systolic BP 60-90 min post captopril was 0.9%-12.4% lower than the basal value. Diastolic BP decreased after captopril administration in 10 patients and increased in 9. The changes in mean arterial pressure and PRA between 0 and 90 min post captopril were inversely correlated (r = 0.605, P less than 0.01). Because of the PRA responsiveness in the normotensive patients with renal scarring, we suggest that there was activation of the renin-angiotensin axis in this group. However, it is not apparent whether such patients are more at risk of developing hypertension at a later time.

Adolescent↗
PubMed1992

Ambulatory blood pressure monitoring and left ventricular mass and function after successful surgical repair of coarctation of the aorta.

Late cardiovascular morbidity and mortality remain significant despite apparently successful surgical repair of aortic coarctation. Alterations in cardiac function have been reported in normotensive patients who have had successful repair, the reasons for which remain unclear. This study addresses the relation between ambulatory blood pressure measurements and alterations in left ventricular performance in 20 patients with normotension at rest after successful repair of aortic coarctation. Exercise testing, ambulatory blood pressure monitoring and two-dimensional echocardiographic studies in 13 boys and 7 girls (mean age 14.2 +/- 2.31 and 14.7 +/- 3 years, respectively) who had no evidence of recoarctation were compared with the findings in 20 matched control subjects. No difference was found in systolic blood pressure at rest or peak exercise between patients and control subjects. Male patients developed a significant arm/leg gradient at peak exercise. Systolic ambulatory blood pressure was higher throughout the day in the male group. In the female group, systolic blood pressure was higher only during sleep. No difference was found in diastolic blood pressure or heart rate. The transverse aortic arch was smaller and the left ventricular mass greater in all patients. The relation of wall stress to rate-corrected velocity of shortening was 2 SD above normal in 8 of the 20 patients, suggesting that some have enhanced contractility. The E/A ratio on the atrial echocardiogram was significantly reduced in the patient group. Successfully treated patients who are normotensive at rest after operation are still at risk for developing end organ damage, which is probably explained by incipient mild hypertension documented by ambulatory blood pressure monitoring.

Adolescent↗
PubMed1992

The peritoneal equilibration test in children.

The peritoneal equilibration test (PET) has been recommended in adults as a standardized means of estimating solute transport. Based on results of the PET, adult peritoneal permeability has been classified as high, high average, low average, and low. We performed a PET on 32 children aged 0.8 to 17.8 years (mean 9.3) using a dwell volume of 32 +/- 5 ml/kg of 2.5% dialysate. Dialysate to plasma (D/P) ratios for creatinine, urea, and sodium were calculated at two and four hours as were the ratios of dialysate glucose at two and four hours to the dialysate glucose at time 0 (D/Do). Stepwise logistic regression identified only the patients' age and D/Do glucose values at two hours as significant predictors of ultrafiltration. Net ultrafiltration after a four hour dwell could be predicted for 75% of children above 9.3 years, or whose D/Do glucose value at two hours was greater than 0.45. The mean and standard deviation values for D/Do glucose and D/P creatinine at four hours were 0.31 +/- 0.17 and 0.71 +/- 0.12, respectively. When children are characterized according to adult standards, at least 70% fall into the high or high average permeability categories.

Adolescent↗
PubMed1991

Autosomal recessive inheritance of vasopressin-resistant diabetes insipidus.

We report on 2 intellectually normal sisters with vasopressin-resistant (nephrogenic) diabetes insipidus (NDI). The sex of the patients, the history of parental consanguinity, and the fact that both parents formed normally concentrated urine suggested that the NDI in the 2 sisters was the result of inheritance of an autosomal recessive mutation affecting renal tubular water reabsorption. The results of DNA analysis of the DXS52 locus with the use of St14 as probe, shown by Knoers et al. [1988] to be tightly linked to the NDI locus on the X-chromosome, showed that each girl inherited different Xq28 regions of the maternal X chromosomes, ruling out a diagnosis of classical X-linked NDI.

Consanguinity↗
PubMed1991

Medical and social outcome in adolescents with end-stage renal failure.

Clinical information was collected on 118 adolescents who developed ESRF at age 143 months or older and were treated between 1966 and 1986 at the Toronto Hospital for Sick Children. The cumulative survival rate in transplanted patients (N = 109) was 80.1% after 15 years. Survival rates after four years were 93.9% in transplanted and 46.9% in nontransplanted patients (P less than 0.001). No patient receiving dialysis alone (N = 9) was followed longer than four years. Nine patients received three transplants and had an 89% survival rate. Six of these had a functioning graft at end of the follow-up. The cumulative survival of the entire group was 76.4% at eighteen years. Forty-two (35.6%) patients had a height below the third percentile. Functional status obtained by a structure telephone interview with a member of the present treating nephrology service was good (G) or excellent (E) for 66.7% of all patients (73.5% of transplant patients (N = 68) and 45% of dialysis patients (N = 20). Hemodialysis patients functioned less well [25% G/E (N = 12)] than peritoneal dialysis patients [75% G/E (N = 8)]. Most patients achieved an appropriate level of formal education although more slowly than normal adolescents. Only 11 patients were neither enrolled in an educational institution nor employed. We conclude that aggressive treatment for adolescents with ESRF is an appropriate application of health care resources.

Adolescent↗
PubMed1991

Hernias associated with CAPD in children.

Twenty-eight hernias occurred in eighteen of seventy-nine pediatric patients on peritoneal dialysis (PD). There was 18 inguinal hernias (6 bilateral) in 12 patients (11 boys and 1 girl) the average age of the male patients with inguinal hernias was 5.2 years vs 9.3 years for the remaining 32 males. Four of the 11 patients were under 2 years old, where as only 3 of the remaining 32 patients were less than 2 (p less than 0.05), and 3 of the 6 patients with bilateral hernias were under 2. A high incidence of recurrent hernias was noted when only high ligation of the hernia sac was performed. We conclude that all candidates for PD should be carefully evaluated for the presence of occult hernias, hernias should be repaired promptly and electively on an inpatient basis, surgical correction of hernias should include a formal Cooper ligament repair and males under 2 should have bilateral repairs done even if they present with a single hernia.

Adolescent↗
PubMed1991

Experience with chronic peritoneal dialysis in infants.

We describe our experience with chronic peritoneal dialysis in 17 infants. Fourteen boys and 3 girls, aged 2.7-22.5 months, were on continuous ambulatory peritoneal dialysis (CAPD) for 215.1 months with 5 infants on continuous cycling peritoneal dialysis (CCPD) for 71.2 months subsequently. Analysis of growth and biochemical data on 16 CAPD and 5 CCPD patients showed poor linear growth despite improved weight gain, high incidence of developmental delay, tendency to lower plasma albumin, phosphate and sodium and increased plasma cholesterol and triglyceride levels. Overall chronic peritoneal dialysis proved to be a possible and effective means of dialysis in infants.

Child, Preschool↗
PubMed1991

Captopril pharmacokinetics, blood pressure response and plasma renin activity in normotensive children with renal scarring.

We studied blood pressure response, plasma renin activity (PRA) and captopril pharmacokinetics in 8 children receiving orally 0.7 mg/kg of the drug. The drug increased PRA in all patients, in 5 to abnormally high levels. Peak captopril concentrations were achieved between half an hour and 2 h, and ranged between 100 and 547 ng/ml. Mean elimination half-time (T1/2) was 1.5 h, ranging between 0.98 and 2.3 h. There was a significant positive correlation between the area under the curve (AUC) and elimination T1/2 of the drug. There was a significant inverse correlation between AUC or elimination T1/2 and percent change in diastolic blood pressure; the 2 children who had no change in diastolic blood pressure had the largest AUC and the lowest apparent clearance of captopril. The kidney is the major site of captopril's pharmacological action. It is possible that longer retention of captopril in the plasma, evidence by larger AUC, may reflect less captopril available to modulate renin activity in the kidney.

Administration, Oral↗
PubMed1991

Use of the captopril test to assess renin responsiveness in children with hypertension and renal disease.

The captopril test was performed on 49 children of whom 36 were hypertensive, and the remainder were normotensive but were at risk for developing hypertension because of scarred kidneys secondary to vesico-ureteral reflux. Blood pressure (BP) was monitored in fasting supine patients throughout the duration of the test. Blood was taken for measurement of plasma renin activity (PRA); then captopril (0.7 mg/kg of body weight) was administered orally. A second blood sample was taken for PRA at 90 min postcaptopril. The mean (SEM) PRA at 90 min was 11.90 (4.01) ng/l/s [42.84 (14.44) ng/ml/h] in 7 patients with renovascular disease. In 4 patients with essential hypertension corresponding values were 0.88 (0.38) ng/l/s [3.17 (1.37) ng/ml/h]. Patients with other renal diseases showed variable values. Some individuals had PRA values as high as those of patients with renovascular disease, but the etiology of their hypertension was usually clinically evident. Our preliminary data would suggest that the captopril test may help differentiate between patients with essential hypertension and those with renovascular disease, or may help select patients that should be followed up by more definitive diagnostic procedures.

Captopril↗
PubMed1990

Coagulation abnormalities in chronic peritoneal dialysis.

To determine whether children treated with chronic peritoneal dialysis have a hypercoagulable state, various coagulation and fibrinolytic factor concentrations or activities were measured in 17 children undergoing chronic peritoneal dialysis. The patients had significantly increased activities of factors VII and VIII, and increased concentrations of von Willebrand factor (vWF), fibrinogen, factor XIIIA and factor XIIIS compared to reference values (P less than 0.001 in each case). The activated partial thromboplastin time was prolonged (P less than 0.001) and the thrombin clotting time was decreased (P less than 0.05) in these children. The prothrombin time and activities of factors XII, XI, IX, X, V and II were not significantly different from control values. Protein C concentrations were similar to normal, but antithrombin III concentrations were increased (P less than 0.05). Within the fibrinolytic pathway, decreased concentrations of plasminogen were found (P less than 0.001) and the concentrations of alpha-2-antiplasmin were increased (P less than 0.001). The plasma albumin concentration was below 33 g/l in 13 of the 17 children. The duration of treatment with peritoneal dialysis was directly correlated with vWF concentrations (P less than 0.001) and inversely correlated with factor VII concentrations (P less than 0.01). Of these patients 2 have since had clinical thrombotic episodes. The coagulation abnormalities found may have a role in the occurrence of thrombosis complicating renal transplantation.

Adolescent↗
PubMed1990

Angiotensin converting enzyme inhibitor therapy to decrease microalbuminuria in normotensive children with insulin-dependent diabetes mellitus.

It has been proposed that lowering glomerular pressure in children with insulin-dependent diabetes mellitus will reduce microalbuminuria and that this reduction may preserve renal function. We therefore conducted a double-blind, placebo-controlled, crossover trial to compare 3 months of treatment with the angiotensin converting enzyme inhibitor captopril (0.9 mg/kg/day), and 3 months of placebo administration to 12 normotensive adolescents with insulin-dependent diabetes mellitus, 11 with microalbuminuria (albumin excretion rate of 15 to 200 micrograms/min) and one with early overt nephropathy. Mean age (+/- SD) was 14.4 +/- 1.7 years, and disease duration was 5.1 +/- 2.5 years. Albumin excretion rate decreased significantly during captopril therapy (baseline 78 +/- 114 micrograms/min; mean of monthly measurements 38 +/- 55 micrograms/min vs placebo 78 +/- 140 micrograms/min; p less than 0.001). During captopril therapy, albumin excretion was reduced by 41 +/- 44% and decreased in 10 of 12 subjects, but was unchanged in two, one with a borderline albumin excretion rate (16.3 micrograms/min) and one with diabetes of short duration (2.9 years). Plasma renin activity rose significantly during captopril therapy, and mean arterial pressure decreased slightly (placebo 81 +/- 7 mm Hg; captopril 76 +/- 5 mm Hg; p = 0.004). After 3 months of captopril treatment, glomerular filtration rate and renal plasma flow did not change significantly. Hemoglobin Alc values remained stable during the study. The only side effect of captopril was diarrhea in one patient. We conclude that, in the short term, captopril is effective in decreasing albumin excretion rate in normotensive children with insulin-dependent diabetes mellitus and microalbuminuria, without significant side effects. Longer trials are indicated in an attempt to delay or prevent overt nephropathy.

Adolescent↗
PubMed1990

Renal autotransplantation in children: a successful treatment for renovascular hypertension.

Renovascular hypertension in children is not a common disease. With improved surgical technique the incidence of nephrectomy has decreased and renovascular reconstruction is currently the preferred method to manage this entity. Between 1977 and 1988, 21 patients with renovascular hypertension were treated at our hospital: 7 patients 6 to 16 years old underwent renal autotransplantation. Of the children 4 had unilateral and 3 had bilateral disease requiring bilateral autotransplantation. Autotransplantation was performed by anastomosis of each renal artery end-to-side to the common iliac artery. The renal veins were anastomosed end-to-side to the common iliac veins. The ureters were left intact in all but 1 patient who required a bench operation. Of the 4 patients who had a unilateral procedure 3 are cured and 1 is improved with a normal blood pressure on a small dose of antihypertensive medication. The 3 patients with bilateral autotransplants are cured. These results, with normalization of the blood pressure in 86% of the patients and improvement in blood pressure in 14% with a patency rate of 87%, are similar to other reported reconstructive modalities in children.

Adolescent↗
PubMed1990

Tracer kinetics and actions of oral and intraperitoneal 1,25-dihydroxyvitamin D3 administration in rats.

Tracer kinetic parameters of [3H]-1,25(OH)2D3 were calculated from data obtained following its acute oral (p.o.) or intraperitoneal (i.p.) administration. In normal rats studied after the tracer had distributed into the body, the slope and intercept of the log-serum [3H]-1,25(OH)2D3 versus time relationship were not significantly influenced by the route of administration. Pretreatment with 1,25(OH)2D3 (0.2 micrograms/100 g/day) by the same route as the tracer resulted in the following changes: in p.o. rats the serum [3H]-1,25(OH)2D3 intercept was much lower but the slope was not changed; in i.p. rats the intercept was not changed but the slope was increased. Both p.o. and i.p. treatment with 1,25(OH)2D3 lowered the weight gain and diet consumption, and increased serum calcium, kidney tissue calcium and urinary excretion of orally administered 45Ca. All the measures of bioactivity were greater in the i.p. dosed rats than in the p.o. dosed rats. We conclude that the p.o. 1,25(OH)2D3 was less potent because of diminished bioavailability due to self induction of its presystemic metabolism and inactivation.

Administration, Oral↗
PubMed1990

Tube feeding in children on chronic peritoneal dialysis.

We feel that tube feeding children on CPD is an important and useful therapy to optimize their growth. Strategies to accelerate growth in such children by using human growth hormone are interesting and await scientific confirmation with controlled trials.

Child↗