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Biomedical subjects

A B Sedman

Publications and source records attributed to A B Sedman.

35 records · Page 2Linked to original sources
PubMed1991

Renal obstructive dysplasia: ultrasound diagnosis and therapeutic implications.

57 cases of renal obstructive dysplasia (defined as the abnormal development of nephronic and ductal structures due to in utero obstruction of the urinary tract) were evaluated in terms of sonographic findings, renal and other associated anomalies, and current status of the child. More than one-third of the cases had bilateral disease and although not uniformly fatal bilateral involvement was associated with significant morbidity and mortality. In 12 of the 33 cases with unilateral dysplasia there was an association with contralateral renal problems including uretero-pelvic junction obstruction, vesicoureteral reflux and aplasia. Almost one-half of the cases had congenital anomalies, these included VACTERL association, congenital heart disease, cranial abnormalities and gastrointestinal malformations. Fifteen stillborns and 12 of the patients with bilateral involvement and four with unilateral involvement have died. Four patients are on dialysis (two with bilateral involvement and two with unilateral renal obstructive dysplasia). Only one-quarter are otherwise normal. More serious problems are reported in this mixed age population of patients with obstructive renal dysplasia than has been identified in previous studies. Management decisions of the fetus and child must be based on this new age-expanded population.

Abnormalities, Multiple↗
PubMed1990

Intrarenal arterial Doppler sonography in patients with nonobstructive renal disease: correlation of resistive index with biopsy findings.

The resistive index (RI), calculated from the duplex Doppler waveform, was compared with clinical and laboratory findings and the results of renal biopsy in 41 patients with nonobstructive (medical) renal disease. Kidneys with active disease in the tubulointerstitial compartment had a mean RI of 0.75 +/- 0.07. This was statistically significantly different (p less than .01) from the RI in kidneys with disease limited to the glomeruli (mean RI of 0.58 +/- 0.05). Acute tubular necrosis resulted in an elevated RI (mean RI = 0.78 +/- 0.03) as did vasculitis/vasculopathy (mean RI = 0.82 +/- 0.05). Patients with hypertension, proteinuria, or hematuria did not have kidneys with a significantly higher RI than did patients without these clinical factors. Kidneys found to be abnormally echogenic did not have an RI significantly different from kidneys of normal echogenicity. There was a weak correlation between creatinine level and RI value, reflected by a linear correlation coefficient of 0.34. In patients with normal renal RIs, the mean creatinine level was 1.7 +/- 1.7, whereas in those with abnormal RI values (greater than or equal to 0.70), the mean creatinine level was 3.7 +/- 3.6. We conclude that some forms of nonobstructive renal disease can produce changes in the Doppler waveform detectable by RI measurement. The production of Doppler waveform changes is strongly influenced by the site of the main disease within the kidneys. Active disease within the tubulointerstitial compartment (acute tubular necrosis, interstitial nephritis) or vasculitis/vasculopathy generally resulted in an elevated RI, whereas disease limited to the glomeruli, no matter how severe, did not significantly elevate the RI. Degree of renal dysfunction as indicated by serum creatinine level probably affects the Doppler waveform to some degree, but the relationship is weak.

Adolescent↗
PubMed1988

Percutaneous nephrostogram in the newborn with bilateral renal cystic disease.

Percutaneous antegrade pyelography should be considered in the few, select, critically ill newborns with bilateral renal cystic disease when the diagnosis is critical to management and difficult with the usual imaging procedures. Two extremely ill newborns with severe oliguria and cystic abnormalities in both kidneys by ultrasound underwent sonographic guidance for percutaneous antegrade nephrostograms in the first week of life. With injection of contrast medium, definitive diagnoses were made of a multicystic dysplastic kidney on one side and an obstructed hydronephrotic kidney on the other, thereby directing decompression of the obstructed kidney to preserve native renal function. This procedure can provide a definitive diagnosis in these rare but difficult cases.

Humans↗
PubMed1987

Radiographic manifestations of experimental aluminum toxicity in growing bone.

To evaluate the effect of aluminum on growing bone in the presence of normal renal function, the following experiment was performed. Eight littermate pair-fed pigs (5 weeks old) were randomly assigned to one of two study groups: control C, n = 4, or aluminum treated Al, n = 4. Daily intravenous injections of either aluminum 1.5 mg/kg/day (Al group) or vehicle only (C group) were given during the 8-week duration of the study. The radiographic findings which appeared in the aluminum-treated group and not in the controls consisted of areas of sclerosis in the submetaphyseal regions and the periphery of epiphyses. In addition there was separation of the anterior tibial tubercle. The growth plates did not increase in width despite the presence of osteomalacia and histologic evidence of extensive deposition of aluminum in bone. The area of sclerosis visualized in the radiographs correlated histologically with thickened bony trabeculae. The increased width of these trabeculae is attributable to an increase in primary spongiosum and broadened seams of osteoid.

Aluminum↗
PubMed1987

Tissue and cellular basis for impaired bone formation in aluminum-related osteomalacia in the pig.

Bone formation is impaired in aluminum-associated bone disease. Reductions in the number of osteoblasts or in the function of individual osteoblasts could account for this finding. Thus, quantitative bone histology and measurements of bone formation were done at three skeletal sites in piglets given aluminum (Al) parenterally, 1.5 mg/kg per d, for 8 wk (Al, n = 4) and in control animals (C, n = 4). Bone Al was 241 +/- 40 mg/kg per dry weight in Al and 1.6 +/- 0.9 in C, P less than 0.001. All Al-treated animals developed osteomalacia with increases in osteoid seam width, osteoid volume, and mineralization lag time at each skeletal site, P less than 0.05 vs. C for all values. Mineralized bone formation at the tissue level was lower in Al than in C, P less than 0.05 for each skeletal site, due to reductions in active bone forming surface. Bone formation at the cellular level was similar in each group, however, and total osteoid production by osteoblasts did not differ in C and Al. Aluminum impairs the formation of mineralized bone in vivo by decreasing the number of active osteoblasts, and this change can be distinguished from the effect of aluminum to inhibit, either directly or indirectly, the calcification of osteoid.

Aluminum↗
PubMed1987

Diagnosis of autosomal dominant polycystic kidney disease in utero and in the young infant.

Autosomal dominant polycystic kidney disease (ADPKD), once thought to be a disease of the adult, is now being reported with increasing frequency in childhood. We report five cases and review eight cases from the literature of ADPKD diagnosed in the fetus or the young infant by sonographic evaluation and a positive family history. Renal enlargement (85%) was the most common and most helpful sonographic finding. Approximately 50% of the patients already had cysts large enough to detect by ultrasound. Increased renal echogenicity was present in nine of 10 cases. Although every case in this review had one parent affected with ADPKD, only five of 13 (38%) were aware of their disease prior to their pregnancy. Renal cystic disease diagnosed in the fetus and young infant should trigger an investigation of the family history and sonographic screening.

Female↗
PubMed1987

Pediatric renal transplantation with an emphasis on the prognosis of patients with chronic renal insufficiency since infancy.

In this report recent experience with renal transplantation in 43 children who were 17 days to 16 years old was reviewed. One-year patient survival rate was 98%, and overall one-year graft survival rate was 68%. One-year graft survival rate was 73% for cyclosporine-treated patients and 78% for recipients of related donor kidneys. A subpopulation of patients affected with renal insufficiency since infancy was analyzed separately to evaluate the prognosis of these patients, who have previously been reported to be a high risk for permanent neurologic, developmental, and growth retardation. All 16 such patients underwent transplantation. Gross motor delay that was noted in 31% of patients before surgery resolved in all patients after transplantation. No evidence of severe developmental delay was noted after transplant and seven of 11 patients with successful transplants had evidence of catch-up growth. Overall renal transplantation is a safe and effective procedure for children with renal failure, and even the patients at highest risk for growth and developmental failure caused by renal insufficiency show potential for rehabilitation after transplantation.

Adolescent↗
PubMed1986

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↗
PubMed1985

Evidence of aluminum loading in infants receiving intravenous therapy.

To investigate the possibility that premature infants may be vulnerable to aluminum toxicity acquired through intravenous feeding, we prospectively studied plasma and urinary aluminum concentrations in 18 premature infants receiving intravenous therapy and in 8 term infants receiving no intravenous therapy. We also measured bone aluminum concentrations in autopsy specimens from 23 infants, including 6 who had received at least three weeks of intravenous therapy. Premature infants who received intravenous therapy had high plasma and urinary aluminum concentrations, as compared with normal controls: plasma aluminum, 36.78 +/- 45.30 vs. 5.17 +/- 3.1 micrograms per liter (mean +/- S.D., P less than 0.0001); urinary aluminum:creatinine ratio, 5.4 +/- 4.6 vs. 0.64 +/- 0.75 (P less than 0.01). The bone aluminum concentration was 10 times higher in infants who had received at least three weeks of intravenous therapy than in those who had received limited intravenous therapy: 20.16 +/- 13.4 vs. 1.98 +/- 1.44 mg per kilogram of dry weight (P less than 0.0001). Creatinine clearances corrected for weight did not reach expected adult values until 34 weeks of gestation. Many commonly used intravenous solutions are found to be highly contaminated with aluminum. We conclude that infants receiving intravenous therapy have aluminum loading, which is reflected in increased urinary excretion and elevated concentrations in plasma and bone. Such infants may be at high risk for aluminum intoxication secondary to increased parenteral exposure and poor renal clearance.

Aluminum↗
PubMed1984

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↗
PubMed1984

Aluminum loading in children with chronic renal failure.

Plasma aluminum levels were measured in 17 children with chronic renal failure who were receiving aluminum containing antacids for the control of hyperphosphatemia. Seven children were on hemodialysis, five on peritoneal dialysis, and five were awaiting dialysis with creatinine clearances between 10 to 20 cc/min/1.73 m2. Plasma aluminum levels correlated directly with oral aluminum dosage; extremely high levels were documented in small, nondialyzed children. Bone aluminum levels were measured in four children with high plasma levels and confirmed significant aluminum loading. Other factors such as the level of aluminum in dialysate and tap water were measured and were not contributory. All patients with plasma aluminum levels greater than 100 micrograms/liter had signs of aluminum toxicity and were receiving greater than 75 mg/kg/day of elemental aluminum orally. We concluded that children who require greater than 30 mg/kg/day of elemental aluminum to control hyperphosphatemia should have plasma aluminum levels monitored and/or be considered for other forms of therapy including more restricted diets and earlier or more aggressive dialysis.

Adolescent↗
PubMedDate not supplied

Treatment of Henoch-Schönlein Purpura glomerulonephritis in children with high-dose corticosteroids plus oral cyclophosphamide.

BACKGROUND: Henoch-Schönlein Purpura (HSP) is a common childhood vasculitis with manifestations in numerous organ systems, including glomerulonephritis. Patients with more severe HSP-associated glomerulonephritis may develop chronic renal failure. Currently, no widely accepted treatment protocols exist for patients with significant renal involvement. METHODS: We retrospectively reviewed the clinical courses of 12 children (mean age 9 years) with HSP glomerulonephritis treated with high-dose corticosteroids plus oral cyclophosphamide. All patients had nephrotic-range proteinuria, and all had significant histopathologic changes on biopsy, including crescentic nephritis in 10 patients. Treatment consisted of either intravenous pulse methylprednisolone or oral prednisone followed by oral cyclophosphamide (2 mg/kg/day) for 12 weeks, along with either daily or alternate-day oral prednisone. Prednisone was tapered following completion of cyclophsophamide. RESULTS: Serum albumin rose significantly after treatment from 2.8 +/- (SD) 0.5 to 3.7 +/- 0.4 g/dl (p < 0.001), and there was a concurrent reduction in proteinuria, as reflected by decreasing serial protein-to-creatinine ratios: from 6.3 +/- 4.4 to 0.8 +/- 0.8 (p = 0.002). Renal function remained normal in all patients. Hypertension developed during treatment in 10 patients, all but 1 of whom were normotensive at last follow-up, 35 +/- 17 months following biopsy. CONCLUSIONS: We conclude that treatment of children with HSP nephritis with high-dose corticosteroids plus oral cyclophosphamide is safe and, as in nephrotic syndrome, appears to significantly reduce proteinuria which is a known risk factor for the development of renal insufficiency in HSP. Further studies with larger numbers of patients should be conducted to confirm this finding.

Administration, Oral↗
PubMedDate not supplied

Hepatic abnormalities associated with aluminum loading in piglets.

Cholestasis is a common complication of total parenteral nutrition (TPN) in infants. A contributing factor to the hepatic dysfunction may be a contaminant of the TPN solution, such as aluminum, that accumulates in liver and may act as a hepatotoxin. To study the hepatic effects of aluminum, growing piglets were given daily intravenous injections of aluminum, 1.5 mg/kg, for 50 days; pair-fed controls were given heparinized saline. At sacrifice, liver and serum were obtained. Liver was analyzed for histopathology and for aluminum content and localization. The hepatocyte lysosomes of the experimental group showed aluminum peaks by x-ray microanalysis, whereas the control group did not. No differences in ultrastructure were noted between the two groups when examined by electron microscopy. Mean serum total bile acid levels (27.8 +/- 15.9 SD vs 6.3 +/- 1.5 mumol/liter, p less than 0.05), mean alkaline phosphatase (309 +/- 108 vs 180 +/- 27 IU/liter, p = NS), and mean hepatic copper content (24.8 +/- 4.5 vs 14.4 +/- micrograms/g dry weight, p less than 0.01), were elevated in the aluminum-loaded piglets, indicating that cholestasis may have been produced. Also, a small but significant reduction in serum levels of 25 hydroxy-vitamin D was found in the aluminum-loaded piglets, suggesting that vitamin D hydroxylation may be impaired. Inasmuch as lysosomal contents are excreted into the bile, aluminum accumulation in lysosomes may alter lysosomal function and possibly affect bile flow or content.

Aluminum↗
PubMedDate not supplied

Serial plasma and urinary aluminum levels and tissue loading in preterm twins.

Serial plasma, urinary, and postmortem tissue aluminum levels were determined in 32-week, appropriate-for-gestational-age twins from 45 to 151 days postnatal age. Estimated total aluminum absorptions were 56.7 mg, and 28 mg, twin A and twin B, respectively. At autopsy, Twin A had a hypoplastic right kidney while Twin B had normal kidneys. Mean plasma aluminum levels (twin A, 34.2 micrograms/liter and twin B, 32.3 micrograms/liter) and urinary aluminum levels expressed as aluminum creatinine ratios (twin A, 11.3 and twin B, 8.5) were similar. These levels were elevated compared to normal plasma aluminum levels of 5.1 +/- 3.6 (1 SD) and urinary aluminum creatinine ratios of 0.64 +/- 0.75 (1 SD). Twin A had higher tissue aluminum levels than twin B in all tissues except for brain. Bone and liver aluminum contents for both twins were increased as compared to infants receiving short-term or no parenteral nutrition. We conclude; (1) tissue aluminum loading occurs in infants receiving aluminum-containing solutions, (2) plasma and urinary aluminum levels are poor predictors of tissue aluminum content, (3) enteral solutions may add significant aluminum exposure.

Aluminum↗