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Biomedical subjects

G M Lum

Publications and source records attributed to G M Lum.

At least 19 recordsLinked to original sources

Cystic renal lymphangiectasia presenting as renal insufficiency in childhood.

Cystic renal lymphangiectasia is an unusual cause of cystic renal disease in childhood. We present a case of bilateral cystic renal lymphangiectasia in a 7-year-old boy who presented with asymptomatic renal insufficiency and anemia with decreased erythropoietin production. The clinical features of this condition and the diagnostic approach are reviewed. Although rare, this disorder should be considered in the differential diagnosis of cystic renal disease.

Anemia↗

Solitary renal myofibromatosis: an unusual cause of infantile hypertension.

INTRODUCTION: Renovascular disease accounts for the vast majority of cases of infantile hypertension with complications resulting from umbilical arterial catheterization predominating in the neonatal period and fibrodysplastic lesions of the renal artery predominating outside the neonatal period. We report a previously undescribed cause of renovascular hypertension: solitary renal myofibromatosis. CASE REPORT: A 9-month-old male infant was transported to the intensive care unit at Children's Hospital in Denver, Colorado, for evaluation and treatment of a dilated cardiomyopathy and severe systemic hypertension. The child was full-term with no perinatal problems. Specifically, the child never required umbilical arterial catheterization. He was well until 6 months of age when his parents noted poor weight gain. At 9 months of age, he was evaluated at the referral hospital for failure to thrive. On examination he was noted to have a blood pressure of 170/110 mm Hg, but no other abnormalities. A chest radiograph showed cardiomegaly. Laboratory studies demonstrated normal electrolytes, blood urea nitrogen, and creatinine. However, urinalysis demonstrated 4+ protein without red blood cells. An echocardiogram showed severe left ventricular dilatation with an ejection fraction of 16%. On admission the child was noted to be cachectic. His vital signs, including blood pressure, were normal for age. The physical examination was unremarkable. Serum electrolytes, blood urea nitrogen, and creatinine were normal. Echocardiographic studies suggested a dilated hypertrophic cardiomyopathy. He was started on digoxin and captopril. Subsequently, he demonstrated episodic hypertension ranging from 170/90 to 220/130 mm Hg. A repeat echocardiogram 24 hours after admission demonstrated a purely hypertrophic cardiomyopathy. Verapamil and nifedipine were added to the treatment regimen in an effort to better control the blood pressure without success. Urine and blood for catecholamines and plasma renin activity, respectively, were sent and treatment with phentolamine instituted because of a possible pheochromocytoma. A spiral abdominal computerized tomographic scan revealed a markedly abnormal right kidney with linear streaky areas of calcification around the hilum and also an area of nonenhancement in the posterior upper pole. The adrenals and the left kidney were normal. Doppler ultrasound revealed a decrease in right renal arterial flow. The urinary catecholamines were normal and surgery was scheduled after the blood pressure was brought under control by medical treatment. At surgery, tumorous tissue and thrombosis of the renal artery were found in the right upper pole. A right nephrectomy was performed. Pathologic examination of the kidney showed the presence of a diffuse spindle cell proliferation in the interstitium of the kidney. The angiogenic/angiocentric character of the proliferation was demonstrated in several large renal vessels. The lumen of most vessels was narrowed and some vessels were totally occluded with recanalization and dystrophic calcifications observed. Immunostaining of the tumor demonstrated strong desmin and vimentin positivity and minimal actin positivity in the spindle cells. Mitotic activity was not noted in the spindle cell process. These pathologic changes were consistent with a diagnosis of infantile myofibromatosis (IM). The child's preoperative plasma renin activity was 50 712 ng/dL/h (reference range, 235-3700 ng/dL/h). DISCUSSION: The causes of systemic hypertension in infancy are many although renal causes are by far the most common. Renal arterial stenosis or thrombosis accounts for 10% to 24% of cases of infantile hypertension. Renal artery thrombosis is usually a consequence of umbilical arterial catheterization, which can also lead to embolization of the renal artery. Renal artery stenosis may result from fibrodysplastic lesions (74%), abdominal aortitis (9%), a complication of renal transplantation (5%), and ren

Cardiomyopathy, Dilated↗

Acute interstitial nephritis associated with loracarbef therapy.

We describe a biopsy-confirmed case of acute interstitial nephritis associated with the use of loracarbef in an 18-month-old boy, which resulted in end-stage renal failure. This complication has been documented with the use of beta-lactam antibiotics, and it seems likely the loracarbef was responsible for acute interstitial nephritis in this patient.

Acute Disease↗

A prospective, double-blind study of growth failure in children with chronic renal insufficiency and the effectiveness of treatment with calcitriol versus dihydrotachysterol. The Growth Failure in Children with Renal Diseases Investigators.

Because controlled trials in adults have shown accelerated deterioration of renal function in a small number of patients receiving calcitriol for renal osteodystrophy, we initiated a prospective, randomized, double-blind study of the use of calcitriol versus dihydrotachysterol in children with chronic renal insufficiency. We studied children aged 1 1/2 through 10 years, with a calculated glomerular filtration rate between 20 and 75 ml/min per 1.73 m2, and with elevated serum parathyroid hormone concentrations. Ninety-four patients completed a mean of 8.0 months of control observations and were randomly assigned to a treatment period; 82 completed the treatment period of at least 6 months while receiving a calcitriol dosage (mean +/- SD) of 17.1 +/- 5.9 ng/kg per day or a dihydrotachysterol dosage of 13.8 +/- 3.3 micrograms/kg per day. With treatment the height z scores for both calcitriol- and dihydrotachysterol-treated groups showed no differences between the two groups. In relation to cumulative dose, there was a significant decrease in glomerular filtration rate for both calcitriol and dihydrotachysterol; for calcitriol the rate of decline was significantly steeper (p = 0.0026). The treatment groups did not differ significantly with respect to the incidence of hypercalcemia (serum calcium concentration > 2.7 mmol/L (> 11 mg/dl)). We conclude that careful follow-up of renal function is mandatory during the use of either calcitriol or dihydrotachysterol because both agents were associated with significant declines in renal function. There was no significant difference between calcitriol and dihydrotachysterol in promoting linear growth or causing hypercalcemia in children with chronic renal insufficiency. Dihydrotachysterol, the less costly agent, can be used with equal efficacy.

Calcitriol↗

Childhood membranoproliferative glomerulonephritis type I: limited steroid therapy.

Nineteen patients with biopsy proven membranoproliferative glomerulonephritis type I (MPGN I) and a minimum of three years of follow-up (mean 6.5 +/- 0.7 years) have been treated with an uncontrolled regimen of limited corticosteroids. Initial therapy ranged from 20 mg per os (po) every other day to 30 mg/kg/day i.v. for three consecutive days, depending on clinical disease severity. Therapy was then decreased based on each patient's improving clinical status. At diagnosis creatinine clearance (CCr) was less than 80 ml/min/1.73 m2 in 12 patients and less than 50 in 2. All patients had hematuria and proteinuria, with 15 in the nephrotic range. Hypertension, present at diagnosis in 13, developed in five others following institution of prednisone, and was controlled medically. Renal biopsy was repeated after two years of therapy prior to cessation of treatment (mean total treatment duration 38 +/- 3 months). Follow-up biopsy revealed decreased glomerular inflammatory activity in 88% of patients. All patients have now been off prednisone for 40 +/- 9 months. The mean CCr is 126 +/- 5 ml/min/1.73 m2. Eight patients have normal urinalyses. These data suggest that early therapy with a limited course of corticosteroids, and control of associated hypertension, may forestall progressive renal insufficiency in children with MPGN type I.

Adolescent↗

Pancreatitis in children on chronic dialysis treated with valproic acid.

Four children treated with maintenance dialysis, three peritoneal and one hemodialysis, developed pancreatitis while receiving valproic acid (VPA) for chronic seizure disorders. Two patients recovered, eventually resuming VPA therapy after successful cadaveric renal transplantation. Two children died after complications of pancreatitis. No episodes of pancreatitis occurred in the other 74 children in this maintenance dialysis population; none of whom received VPA. Although pancreatitis is a known complication of VPA treatment or end-stage renal disease (ESRD), this is the first reported series specifically relating pancreatitis to VPA administration in children treated with maintenance dialysis. The literature related to the association of pancreatitis with VPA administration and ESRD therapy is briefly reviewed and the clinical implications are discussed.

Child↗

Descriptions of the participating centers and patient population in the Growth Failure in Children with Renal Diseases Study.

The Growth Failure in Children With Renal Diseases Study, a double-blind, multicenter clinical trial with 108 children entered into the control period over 4.3 years of patient enrollment (December 1984 to April 1989), is being extended for 3 years (December 1988 to December 1991) to provide the time needed to accrue additional patients, aged between 1 1/2 and 10 years, with glomerular filtration rates of 20 to 75 ml/min/1.73 m2. The study design of randomization to two treatment arms (1,25-dihydroxyvitamin D vs dihydrotachysterol) requires a total of 108 patients with a minimum of 6 months of treatment to test the long-term effectiveness and safety of 1,25-dihydroxyvitamin D, an essential part of the therapeutic regimen for children with chronic renal insufficiency. The frequent longitudinal assessments of nutrition and growth in children with chronic renal insufficiency can better define the natural history of renal disease and its influence on growth. Similar data in the treatment period will define the impact of treatment with 1,25-dihydroxyvitamin D3 versus dihydrotachysterol on this natural history. Linear growth must be observed long enough (6 to 12 months minimum) to permit valid quantitation and comparison of the two vitamin D treatment arms, the multiple confounding variables that affect growth (e.g., steroid therapy, diabetes mellitus, prior vitamin D treatment) must be rigorously excluded or controlled, and the assignment of patients to the two groups must be random. These controls--sufficient study duration, sufficient patient numbers, and randomization--should eliminate extraneous sources of variation, including seasonal periodicity. This carefully developed, double-blind clinical trial with multiple participating centers and an effective organizational structure is coming close to achieving the goals of the study. An explosion of data regarding the natural history of chronic renal insufficiency and its treatment with vitamin D metabolites will be forthcoming at the conclusion of the study.

Child↗

Unexpected seizures during hemodialysis. Effect of dialysate prescription.

To assess the effects of the dialysate prescription on the intradialytic neurological stability of children requiring chronic hemodialysis (HD), continuous EEG monitoring (CEM) was performed on five children before, during and after HD against: (1) low sodium acetate (LAc: Na 132 mEq/l, acetate 38 mEq/l); (2) high sodium acetate (HAc: Na 144 mEq/l, acetate 41 mEq/l), and (3) low sodium bicarbonate (LBi: Na 133 mEq/l, bicarbonate 35 mEq/l) dialysate. Three children, two with clinically well-controlled seizure disorders and one with no seizure history, exhibited subclinical seizures on LAc and HAc but improved neurological stability on LBi. Two children had essentially unchanged CEM studies on any HD regimen. Symptoms of disequilibrium were noted in four of the five children on LAc, two of the five on HAc and only one of the five on LBi. The data suggest that bicarbonate HD may enhance intradialytic neurological stability, particularly in children with known seizure disorders. Furthermore, CEM was found to be a useful tool for evaluating the neurological stability of children during HD.

Adolescent↗

A unique approach to peritoneal dialysis in infants.

Little recorded experience exists concerning the use of chronic peritoneal dialysis in the infant. We herein report the results of a multidisciplinary approach to two infants who were treated with a unique modification of "short-dwell" peritoneal dialysis. A single-bag technique was devised in the hopes of reducing glucose absorption and protein losses while concomitantly permitting a simplified manual method of cycling peritoneal dialysis. The desired nutritional needs of the infants consisted of a caloric intake of 140 calories/kg/d and a protein intake of 3.0 to 4.0 g/kg/d, a goal that often required administration through a nasogastric tube. The timely initiation of peritoneal dialysis and the strict adherence to the prescribed dietary regimen was associated with continued growth in both patients. Repeated developmental assessments of each child were conducted and revealed normal development in one patient and mild delay, but gradual improvement, in the other.

Blood Urea Nitrogen↗

Decline of vaccine-induced antipneumococcal antibody in children with nephrotic syndrome.

Twenty-five children with steroid-responsive idiopathic nephrotic syndrome were studied for persistence of antipneumococcal capsular polysaccharide antibody during relapse of their disease and at 1, 6, and 12 months after vaccination with the 14-valent pneumococcal vaccine. Nonrelapsers (group I) were compared to those who had at least one relapse but whose sera were obtained during remission (group II). Group II had a more rapid decline in total anticapsular antibody per month than group I (5.3% v 2.4%). Analysis by individual anticapsular types showed that differences between groups approached significance only for type 4 (P = .07). Rates of decline of antibody against pneumococcal capsular polysaccharide varied among types. One year after vaccination, 50% of patients had less than 300 ngAbN/mL against types 4, 6A, 7F, 8, and 19F. Sera obtained from seven patients during relapse had geometric mean antibody concentrations less than 300 ngAbN/mL against those same types; two of these types have been reported to cause disease in vaccinated patients with nephrosis. Decline of antibody against pneumococcal capsular polysaccharide following vaccination varies by capsular type. Type-specific analysis should be used when monitoring serum antibody levels in these patients after vaccination.

Adolescent↗

Aluminum intoxication in a child: treatment with intraperitoneal desferrioxamine.

We report the successful chelation of aluminum and the clinical resolution of severe aluminum intoxication in an infant receiving chronic peritoneal dialysis through the use of intraperitoneal desferrioxamine. Following the introduction of desferrioxamine, urine and dialysate fluid aluminum levels exceeded those noted without the chelating agent, thus demonstrating enhanced removal of aluminum. As a result of therapy, plasma and bone aluminum levels decreased markedly, and previously noted histomorphometric abnormalities on bone biopsy resolved. Clinically, the aluminum-associated osteomalacia and microcytic hypochromic anemia completely reversed. Moderate developmental delay has also improved slightly but persists. Our experience suggests that intraperitoneal chelation therapy with desferrioxamine may be helpful to reverse aluminum intoxication in children with chronic renal failure. However, limited exposure to aluminum should remain a primary goal.

Aluminum↗

Prednisone therapy of membranoproliferative glomerulonephritis in children.

Six children with biopsy-proved type 1 membranoproliferative glomerulonephritis (MPGN) improved clinically during a 2-year course of prednisone therapy. All children had nephrotic syndrome. Creatinine clearance was less than or equal to 80 ml/min/1.73 m2 in four patients. Initial prednisone dosage ranged from 20 mg every other day to 2 mg/kg/day (maximum 60 mg), with subsequent modifications based on improvement. After completion of a 2-year course of steroid therapy, a repeat kidney biopsy was performed in each child; a decrease in glomerular disease activity was noted in five of them. After a mean follow-up of almost 5 years, all children have creatinine clearance greater than 120 ml/min/1.73 m2, and only one remains nephrotic. Although the use of prednisone in children with MPGN remains controversial, we have observed a diminution in proteinuria and normalization of creatinine clearance with therapy initiated early in the disease course.

Adolescent↗

Peritonitis with continuous ambulatory peritoneal dialysis and continuous cycling peritoneal dialysis.

The frequency and cause of peritonitis in 18 children receiving continuous ambulatory peritoneal dialysis (CAPD) and nine children receiving continuous cycling peritoneal dialysis (CCPD) are described. Cumulative CAPD and CCPD experience demonstrated 58 episodes of peritonitis in 294 patient treatment months (one case per 5.1 patient treatment months). Total hospitalization for the treatment of peritonitis was 0.18 days per patient treatment month. Life table analysis revealed no significant difference in the peritonitis-free "survival" between the two modalities. Gram-negative organisms accounted for a significantly increased percentage of the peritonitis in CAPD compared with CCPD (65% vs 17%) (P less than 0.001). Thirty-seven percent of the gram-negative infections in the CAPD population were in children with nephrostomies. Factors predisposing to peritonitis were identified in 76% of cases occurring with CAPD. Peritonitis remains the major contributor to the morbidity associated with peritoneal dialysis, regardless of the technique. The resultant frequency of hospitalization is not prohibitive. Attention to the "high-risk" pediatric patient and education directed at several well-recognized predisposing factors may yield improved results.

Acinetobacter Infections↗