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Biomedical subjects

F B Stapleton

Publications and source records attributed to F B Stapleton.

At least 109 records · Page 6Linked to original sources
PubMed1983

Evaluation of T lymphocyte subpopulations in children with nephrotic syndrome.

We have evaluated lymphocyte subsets both quantitatively and functionally in children with nephrotic syndrome. Ten children had minimal change nephrotic syndrome (MCNS), seven had focal segmental glomerular sclerosis (FSGS) and four had recovered from MCNS. Two patients with FSGS had decreased OKT4+ cells and a decreased T4/T8 ratio. Patients with active MCNS synthesized significantly less IgM in vitro than did normal subjects (P less than 0.005). In vitro IgG synthesis was significantly decreased in patients with active nephrotic syndrome whether it was due to MCNS or FSGS. Co-culture studies involving lymphocyte subsets suggested that both patients with decreased percentages of T4+ cells had decreased T helper cell activity as well. The results of this study support previous speculation about abnormal immune function in some patients with nephrotic syndrome.

Antibodies, Monoclonal↗
PubMed1983

Reflux nephropathy complicated by acute post-streptococcal glomerulonephritis.

A 7 years old male with severe bilateral vesicoureteral reflux developed acute renal failure without evidence of either infection or obstruction. The diagnosis of acute post-streptococcal glomerulonephritis was confirmed by clinical, serological and histological evaluation. The patient's creatinine clearance decreased from 25 ml/min/1.73 m2 to 10-13 ml/min/1.73 m2 following the acute nephritic episode and chronic dialysis therapy was required thereafter. This patient illustrates that a glomerular etiology should be suspected when acute renal failure occurs in a patient with reflux nephropathy and suggests that the prognosis of acute post-streptococcal glomerulonephritis may be worse in children with pre-existing renal disease.

Acute Disease↗
PubMed1982

Hypercalciuria in children with urolithiasis.

The pathogenetic roles of idiopathic renal hypercalciuria and absorptive hypercalciuria in children with urolithiasis have not yet been determined. Oral calcium loading studies were performed in 21 children with unexplained calcareous urolithiasis. Thirteen children, aged 20 months to 17 years, were found to have renal hypercalciuria after an overnight fast (urinary calcium-urinary creatinine [UCa/UCr] ratio in milligrams, greater than 0.21). Four children were found to have absorptive hypercalciuria. In this group, fasting UCa/UCr values were normal (SEM, 0.12 +/- 0.02); however, UCa/UCr values were elevated (SEM, 0.31 +/- 0.01) after the oral calcium load. Serum parathyroid hormone values were normal in all children with hypercalciuria. Urinary calcium excretion was normal in four patients. These data indicate that hypercalciuria may frequently occur in children with urolithiasis and that detailed metabolic evaluation is warranted in children with kidney stone disease.

Absorption↗
PubMed1982

Cystic kidneys in a patient with oral-facial-digital syndrome type I.

A cystic renal lesion is described in a girl with oral-facial-digital syndrome, type I. Excretory urography was normal at 1 yr of age; however, flank masses, hypertension, and renal failure were discovered at 11 yr of age. Bilateral nephrectomies were performed prior to renal transplantation. The renal cortex was replaced by large cysts. The cysts were lined by flattened nondescript epithelium and many contained glomerular tufts. Twenty renal cysts were aspirated, and the cyst fluid analyzed for sodium, potassium, creatinine, and osmolality. The concentration of solutes in the cyst fluid was comparable to plasma values. The pathologic features and pattern of cyst solute concentration appear to distinguish the cystic renal lesion in oral-facial-digital syndrome from the more common adult-type polycystic kidney disease.

Abnormalities, Multiple↗
PubMed1982

Adrenal responsiveness in children with steroid responsive idiopathic nephrotic syndrome.

Impaired adrenal cortical responsiveness to ACTH has been reported in children with steroid responsive nephrotic syndrome. Plasma cortisol levels at 8 AM and 2 hours post ACTH stimulation were measured on 42 occasions in 33 children with steroid-responsive nephrotic syndrome. Twenty-two of 42 fasting 8 AM plasma cortisol and 39 of 42 post-ACTH plasma cortisol values were subnormal. Plasma cortisol values were similar in children evaluated prior to, immediately following or 2-24 moths after prednisone therapy. No relationship was observed between 8 AM or post-ACTH plasma cortisol values and serum albumin concentration or the presence of edema. Impaired adrenal responsiveness to ACTH was not helpful in predicting the length of clinical remission. Hydrocortisone replacement therapy given to five children with impaired ACTH-responsiveness did not alter the rate of relapses observed prior to this treatment.

Adolescent↗
PubMed1982

Urinary excretion of calcium following an oral calcium loading test in healthy children.

The ratio of urinary calcium (UCa)/urinary creatinine (UCr) concentrations (mg/mg) during calcium loading has been used to diagnose hypercalciuric states in adults. The UCa/UCr ratios have been examined before and after an oral dose of calcium in 48 healthy children following five days of abstinence from dietary milk products. No differences in UCa/UCr ratios were observed between sexes, races, or age groups. UCa/UCr ratio before the calcium dose was 0.09 +/- 0.12 (mean +/- 2 SD) and increased to 0.12 +/- 0.15 in urine samples collected for four hours after the calcium load. A direct relationship between UCa/UCr ratio and urinary sodium (UNa)/UCr ratio was observed (r = .57, P less than .01). In six children, calcium loading studies were repeated without prior restriction of dietary calcium. Dietary calcium intake before the calcium loading had little effect upon UCa/UCr ratio before the calcium in these six children (0.068 vs 0.08); however, UCa/UCr values after the calcium load were significantly lower (0.08 vs 0.15) when no dietary calcium restriction preceded the calcium-loading study. These data may allow characterization of renal hypercalciuria and gastrointestinal hyperabsorption of calcium in children with urolithiasis.

Adolescent↗
PubMed1981

Hematuria preceding renal calculus formation in children with hypercalciuria.

Five children were evaluated for painless hematuria; currently recommended diagnostic studies were unsuccessful in determining a diagnosis. A renal calculus subsequently was passed or detected radiographically in each child from 14 to 20 months after the initial evaluation. Hypercalciuria was then demonstrated by quantitation of 24-hour urinary calcium excretion or by measurement of urinary calcium/creatinine ratio. Calculi and hematuria have not recurred following thiazide therapy. We infer that idiopathic hypercalciuria was a probable cause of the unexplained painless hematuria.

Calcium↗
PubMed1981

Renal pathogenesis of familial hyperuricemia: studies in two kindreds.

The pathogenesis of familial hyperuricemia has been investigated in two kindreds in whom hyperuricemia was present in members of successive generations. Enzymatic and metabolic studies, including the incorporation of isotopically labeled glycine into urinary uric acid and assessment of the total excretion of oxypurines in one family, excluded a metabolic etiology. No secondary cause of hyperuricemia was identified in either family. Fractional excretion of uric acid was less than 6.2% in all hyperuricemic individuals studied, while creatinine clearances were normal. Tubular secretion of uric acid and tubular reabsorption of uric acid were studied in an affected teenager from each family while receiving a purine-free diet. Inhibition of secretion of uric acid with pyrazinamide decreased fractional excretion of uric acid to 0.6% in patient S and to 0.7% in patient B. Tubular secretion of uric acid at maximal response to pyrazinamide in these patients was 0.393 and 0.410 mg/dl glomerular filtration rate(nl response 0.300 to 1.30 mg/min/100ml inulin clearance). Probenecid, an inhibitor of uric acid reabsorption, increased uric acid excretion by 3.9 mg/min and by 3.2 mg/min (nl response 1.7 +/- 0.3 mg/min) in patients S and B. Tubular reabsorption of uric acid distal to secretory sites was determined by assessing the uricosuric response to probenecid plus pyrazinamide. Uric acid excretion increased by only 0.08 mg/min in patient A and by 0.17 mg/min in patient B (nl response 0.9 mg/min). Ascorbic acid increased fractional excretion of uric acid by 7.2% in patient S but was not uricosuric in patient B or any hyperuricemic member of his family. These data suggest that hyperuricemia in these families is due to diminished renal clearance of uric acid and that the reduced clearance is due to increased tubular reabsorption of uric acid distal to secretory sites.

Adolescent↗
PubMed1981

Ontogeny of renal uric acid excretion in the mongrel puppy.

Renal uric acid excretion was examined in 35 mongrel puppies at 1, 30, 60 and 90 days of age and in seven mature mongrel dogs. Uric acid concentrations in plasma and urine were determined using a uricase fluorometric method. Clearance of inulin increased with postnatal age; however, fractional excretion of uric acid (FEUA) decreased from 83% at birth to 51% at 90 days of age (r = -0.675, P less than 0.001). Filtered uric acid and net reabsorption of uric acid increased with postnatal development. The decline in FEUA with postnatal age was unrelated to binding of uric acid to plasma proteins or to urine flow rate. A direct correlation was observed between clearance of uric acid (CUA) and clearance of sodium (CNa) during early development (r = 0.48, P less than 0.001). These data indicate that postnatal maturational patterns of renal urate excretion in mongrel puppies are similar to human newborns.

Age Factors↗
PubMed1981

The alternate complement pathway. A possible role in a patient with focal glomerular sclerosis.

A boy had focal segmental glomerular sclerosis after the resolution of an unusual transient functional defect in activation of the alternate complement pathway. Prior to 1 year of age, the patient suffered repeated serious bacterial infections that were associated with an inability to opsonize Escherichia coli ON 2 in vitro. Serum levels of complement components were normal. Shortly after resolution of the complement defect, nephrotic syndrome developed. Properdin and C3 were identified in sclerotic glomeruli, which suggests that the ability to activate the alternate complement pathway played a role in the pathogenesis of glomerular sclerosis.

Biopsy↗
PubMed1980

The cystic renal lesion in tuberous sclerosis.

A characteristic cystic renal lesion is described in three infants with tuberous sclerosis. Large cystic kidneys were present at birth in one child. The other two patients were discovered to have cystic kidneys and hypertension at 3 months of age. Development delay and seizures were ultimately present in two infants; typical cutaneous lesions of tuberous sclerosis developed in only one child. The roentgenographic appearance of the kidneys in the two older children was similar to that of adult-type polycystic kidney disease. Cysts were lined by a distinctive, hyperplastic epithelium in each patient. The diagnosis of tuberous sclerosis may be determined by renal biopsy in infants presenting with cystic kidneys.

Diagnosis, Differential↗
PubMed1978

Uric acid excretion in normal children.

Standard values were established for urinary excretion and clearance of uric acid in 95 normal, nonhospitalized children. We found that urinary uric acid excretion and serum uric values increase throughout childhood; that in early childhood, fractional excretion and clearance of uric acid are higher than adult norms; and that despite an increasing filtered load of uric acid, there is a progressive decrease in fractional excretion and clearance of uric acid with advancing age. Some tubular maturational change, either decreasing secretion or increasing reabsorption, must account for the progressive decline in fractional excretion and clearance of uric acid.

Adolescent↗
PubMed1978

Effect of ouabain and colloid osmotic pressure on renal tubule cell volume.

Proximal renal tubule cell volume increases in ouabain but cell swelling is limited by the tubule basement membrane (TBM) and the colloid osmotic pressure from the bath protein. We compared the effect of ouabain, external protein concentration, and TBM on cell volume of proximal convoluted (PCT), proximal straight (PST), and cortical collecting tubules (CCT). We blocked active solute transport with ouabain and evaluated cell size by measuring the outer diameter of nonperfused tubules. Proximal tubules in ouabain swelled 35-40% in isoncotic medium and 20-25% further in hyponcotic medium (0.3 g/100 ml albumin), but PCT swelled faster than PST. The CCT swelled minimally in similar mediums, indicating pronounced heterogeneity in the response of cortical nephron segments to ouabain. In the presence of ouabain, all tubules swelled extensively when we removed the TBM with collagenase. In the hyponcotic medium fluid flux across the peritubular membrane was 0.081, 0.049, and 0.030 nl/min per mm tubule length for PCT, PST, and CCT, respectively. The rates of fluid flux in PCT and PST were proportional to estimates of the respective basolateral surface areas. We suggest that differences in swelling rates between proximal segments reflect variations in surface area rather than intrinsic peritubular membrane permeability to solute and water.

Animals↗
PubMed1978

Hypertension associated with the Guillain-Barré syndrome.

Guillain-Barré syndrome (GBS) is frequently complicated by hypertension, which has been ascribed to sympathetic nervous system hyperactivity. We report the case of a child with GBS and hypertension that appeared to be related to increased renin-angiotensin activity. Urinary catecholamine excretion was normal. Propranolol therapy successfully controlled the hypertension. Evaluation of the renin-angiotensin system and catecholamine excretion is indicated in patients with GBS and hypertension.

Catecholamines↗