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Biomedical subjects

B L Warshaw

Publications and source records attributed to B L Warshaw.

At least 19 recordsLinked to original sources
PubMed2001

Tacrolimus rescue therapy for children with acute renal transplant rejection.

Seventeen children with renal transplants (11 living-related, age 2-18 years) were converted from cyclosporine to tacrolimus because of acute rejection that failed to respond to high-dose corticosteroids. Resistance to corticosteroids was confirmed by renal biopsy in 14 patients, and assumed in 3 patients because of failure of serum creatinine to improve to baseline values. Four patients were also treated with OKT3, and 15 children had been receiving mycophenolate maintenance therapy prior to conversion to tacrolimus. Rejection occurred at 2-174 weeks post transplant (mean 52 weeks). Actuarial 1- and 2-year graft survival was 87% and 78%. Three children progressed to end-stage renal disease after 4, 12, and 13 months of tacrolimus. The remaining 14 children have functioning allografts after 20-168 weeks of treatment (mean 80 weeks). All 14 children exhibit stable or improved renal function: serum creatinine 1.1+/-0.7 mg/dl versus 2.0+/-0.9 mg/dl prior to tacrolimus. In conclusion, tacrolimus was effective therapy for both early and late acute rejection in children who failed to respond to high-dose corticosteroids. No significant short-term adverse effects were encountered.

Acute Disease↗
PubMed1996

Bacteremia in a pediatric hemodialysis unit secondary to Enterococcus fecalis.

UNLABELLED: Bacteremia is often a serious and recurring problem in children with hemodialysis catheters. We report an outbreak of Enterococcus bacteremia in a pediatric hemodialysis unit occurring from June 1992 to June 1993. During this period, 18 episodes of bacteremia occurred in eight children; 11 infections were polymicrobial. Enterococcus fecalis was associated with 13 infections in five patients (8 polymicrobial). Other pathogens included Enterobacter cloacae (5 infections), Staphylococcus (3), Staphylococcus epidermidis (2), and Klebsiella pneumoniae (2). All Enterococcus infections occurred in patients with dual-lumen subclavian venous catheters. Skin and catheter sites were culture negative, except in one patient. Rectal swabs were positive for Enterococcus in five patients. Enterococcus was not isolated from any source within the unit. Serotypes of all Enterococcus isolates were different, except for 2 isolates in the same patient. Starting in June 1993, catheters were flushed after dialysis with vancomycin or ampicillin. Since initiating this procedure, further episodes of Enterococcus bacteremia have not occurred. A questionnaire sent to other pediatric hemodialysis units failed to identify Enterococcus among 26 cases of bacteremia. IN CONCLUSION: (1) Enterococcus is an unusual pathogen for hemodialysis-related bacteremia in children; (2) patients with dialysis catheters were predisposed to this infection; (3) a common source for Enterococcus could not be identified by either culture or by serotyping; (4) flushing catheters with antibiotics after dialysis was effective prevention.

Bacteremia↗
PubMed1996

Evolving strategies in immunosuppressive therapy: the Emory experience.

We have reviewed our experience with various immunosuppression regimens over the past 11 years in 2,065 renal transplant recipients. Patients received triple-drug maintenance therapy with CsA, imuran and prednisone following either no induction therapy or treatment with polyclonal (PCA) or monoclonal (MCA) antibody. The most recent immunosuppressive regimen has included CsA, MMF, and prednisone without induction therapy. We observed that those patients receiving PCA had a better graft survival 5 years after transplantation than recipients with MCA induction or those receiving standard triple drug therapy without induction. Patients receiving MMF experienced superior one-year graft survival compared with those receiving induction with PCA, MCA or standard triple drug therapy. A similar one-year graft survival rate for both Black and White recipients was observed in the MMF group and raises the possibility of achieving improved long-term graft survival in Black recipients with a MMF-based immunosuppression strategy. Our experience indicates that excellent short-term graft survival can be achieved with an immunosuppressive protocol of MMF, CsA and prednisone without induction. Graft survival in MMF-treated recipients was equal to or superior to that which we previously achieved with induction therapy.

Antilymphocyte Serum↗
PubMed1989

IgG subclasses in children with nephrotic syndrome.

To determine whether the hypogammaglobulinemia of childhood nephrotic syndrome is characterized by symmetric depression of the IgG subclasses, the authors compared the IgG subclass concentrations in nephrotic patients in relapse versus remission. The authors used a highly sensitive monoclonal antibody-based enzyme immunoassay that allows quantitation with comparable precision of all four subclasses. They analyzed 28 sera obtained from 22 nephrotic patients during relapse (n = 16) and/or remission (n = 12). The mean ages of the two groups were similar. IgG1 and IgG2 were significantly decreased during relapse compared with remission, whereas IgG3 and IgG4 were not significantly different. This pattern of asymmetric depression of IgG subclasses supports a cause other than urinary losses in the pathogenesis of this abnormality.

Adolescent↗
PubMed1989

Daily single-dose and daily reduced-dose prednisone therapy for children with the nephrotic syndrome.

Most current reference sources recommend that initial therapy for minimal lesion nephrotic syndrome consist of prednisone, 60 mg/m2 per 24 hours or 2 mg/kg per 24 hours, given in divided doses, and that this regimen be repeated for each relapse. The need for divided-dose daily-administered prednisone is predicated on anecdotal observations that single-dose daily administration is not effective. Because single-dose daily-administered and reduced-dose daily-administered prednisone has been used to treat this condition for several years, experience with these regimens in nephrotic children was analyzed. Forty-one patients were studied, including 22 treated from the onset of their disease. Of these 22, 17 (77%) responded to single-dose daily-administered prednisone (2 mg/kg); after subsequent biospy, each of the nonresponders proved to have lesions other than minimal change disease. The mean response time with single-dose daily-administered prednisone (9.6 days for treatment of the initial onset of nephrotic syndrome and 11.1 days for treatment of relapses) was comparable to that previously reported with divided-dose regimens. In 14 patients with frequent relapses, a single reduced-dose daily-administered dose of prednisone (0.2 to 1.5 mg/kg/d) successfully induced remissions in 55 of 63 relapse episodes. It is concluded that a single morning dose of prednisone effectively induces remission in children with minimal lesion nephrotic syndrome. Among selected patients with frequent relapses, additional steroid sparing may be achieved by the use of this regimen with reduced doses during treatment of relapses.

Child↗
PubMed1987

Thiazide diuretics for the treatment of children with idiopathic hypercalciuria and hematuria.

We describe our experience in 14 children with idiopathic hypercalciuria and hematuria who received a finite course of thiazide diuretics. Thiazides reduced urinary calcium excretion and resolved hematuria in all cases. Serum calcium concentration was not altered with treatment. Serum potassium concentration decreased, and total carbon dioxide content and uric acid concentrations increased in response to therapy but these changes did not necessitate discontinuation of treatment. Thiazides were discontinued electively after 16 +/- 15 months of treatment (range 3 to 40 months). Six children maintained normal urinary calcium excretion, while 8 displayed excessive calcium excretion for 16 +/- 4 months after treatment was stopped. Renal calculi were not detected in any patient during this interval but hematuria recurred in 4 children. These findings suggest that thiazides are safe and effective for resolving hypercalciuria and hematuria. Thiazides may be discontinued safely in some children, while others will require further treatment courses or prolonged continuous therapy.

Benzothiadiazines↗
PubMed1985

Families of children with idiopathic hypercalciuria. Evidence for the hormonal basis of familial hypercalciuria.

Six children with idiopathic hypercalciuria and their families were examined with an oral calcium loading test. Family members were divided into two clinical categories: group 1 consisted of the six index children and their parents and siblings with urolithiasis or unexplained hematuria; group 2 comprised the remaining parents and siblings without signs or symptoms associated with hypercalciuria. The results revealed that fasting urinary excretion of calcium was similar in both groups, but group 1 displayed a greater calciuric response to an oral calcium load. Serum concentrations of calcitriol (1,25-dihydroxyvitamin D3) and calcium were higher in group 1 than in group 2, while parathyroid activity was lower in group 1 patients. Urinary excretion of sodium, phosphorus, and magnesium, urine pH, serum levels of calcifediol (25-hydroxyvitamin D3) and phosphorus, and the renal tubular threshold for phosphate were not significantly different in the two groups. These findings suggest that idiopathic hypercalciuria may arise from a disturbance in the regulation of vitamin D metabolism that mediates enhanced intestinal absorption of calcium.

Adult↗
PubMed1985

Prognostic features in infants with obstructive uropathy due to posterior urethral valves.

The histories of 22 infants presenting during the first year of life with obstructive uropathy due to posterior urethral valves were analyzed to determine outcome and prognostic features. Mean patient age at the time of the initial surgical intervention was 39 days, and the mean duration of followup inclusive of renal function data was 5.8 years. One patient died (5 per cent) and one had end stage renal disease. The mean preoperative and postoperative serum creatinine concentrations during the initial hospitalization were 3.1 and 1.4 mg. per dl., respectively. Neither value was significantly predictive of the creatinine concentration at final followup. In contrast, the nadir creatinine value during the first year of life correlated significantly with final renal function. Children with nadir creatinine values less than or equal to 0.8 mg. per dl. by 12 months of age maintained creatinine levels less than or equal to 1.1 mg. per dl. at the time of final evaluation, whereas children with higher values during the first year of life were likely to have progressive renal failure. Of 19 final creatinine determinations 6 were normal and 5 exceeded 1.5 mg. per dl. Proteinuria, hypertension, renal biopsy findings, urinary infection, unilateral nephrectomy and type of surgery did not correlate significantly with functional outcome. Followup studies of longer duration are needed to determine the ultimate outcome of these patients, more than half of whom had some degree of renal insufficiency at final evaluation.

Blood Pressure↗
PubMed1984

Ocular involvement in primary hyperoxaluria.

Ocular involvement from primary hyperoxaluria developed in one infant and one teenaged patient. Autopsy procedures in the first case used special histopathologic staining techniques to demonstrate a wider deposition of calcium oxalate crystals within the eye than was previously suspected. Clinical photographs and fluorescein angiograms in the older patient demonstrated a widespread retinal distribution of crystals with a periarterial predilection. This patient also demonstrated a unique acquired black macular lesion.

Adolescent↗
PubMed1984

Idiopathic hypercalciuria. Renal and absorptive subtypes in children.

Twelve children with urolithiasis or unexplained episodes of gross hematuria, hypercalciuria, and normal serum calcium levels were examined with an oral calcium loading test. Eight patients displayed elevated fasting urinary calcium excretion, consistent with renal hypercalciuria; four exhibited normal fasting calcium excretion, which increased excessively with calcium loading, suggesting hyperabsorption of intestinal calcium. Evidence of secondary hyperparathyroidism was detected in three children with renal hypercalciuria on the basis of urinary cyclic adenosine monophosphate (cAMP) excretion. Serum calcium concentrations obtained four hours after loading increased significantly in children with renal hypercalciuria and were directly correlated with fasting urinary calcium excretion. Among patients with renal hypercalciuria, serum calcium level was higher in patients with normal fasting cAMP excretion. These results suggest that hyperabsorption of intestinal calcium occurs in renal hypercalciuria and may account for the lower-than-predicted incidence of secondary hyperparathyroidism in these patients. Idiopathic hypercalciuria may arise from one fundamental metabolic disturbance with varying degrees of expression, rather than from two separate pathogenic mechanisms.

Adolescent↗
PubMed1984

Vitamin D replacement therapy and renal function. Calcitriol v dihydrotachysterol.

We treated 24 patients who had chronic renal insufficiency and renal osteodystrophy with either calcitriol (1,25-dihydroxyvitamin D3) or dihydrotachysterol. Renal function was evaluated before and during treatment to determine if these vitamin D analogues caused an accelerated rate of renal function deterioration. An accelerated rate of increase in the serum creatinine level was found in three of 12 patients in each treatment group after therapy was started, but the mean rate of increase during treatment did not differ significantly from the rate during the pretreatment control period in either group. The occurrence of hypercalcemia or an excessive serum calcium x phosphorus-product did not correlate with the rate of change in renal function during treatment with either drug. We concluded that children receiving calcitriol are not at greater risk for an accelerated rate of renal function deterioration than are children treated with dihydrotachysterol. Furthermore, neither vitamin D analogue could be directly implicated as a cause of an accelerated rate of renal function deterioration when episodes of hypercalcemia were transient and occurred infrequently.

Adolescent↗
PubMed1984

Decreased serum transferrin concentration in children with the nephrotic syndrome: effect on lymphocyte proliferation and correlation with serum immunoglobulin levels.

Recent evidence suggests that transferrin has immunoregulatory functions. In the nephrotic syndrome, excessive urinary losses can produce hypotransferrinemia. Whether low serum transferrin concentration in children with the nephrotic syndrome is related to their decreased immunoglobulin concentrations and to the decreased in vitro response of lymphocytes to a mitogen was studied. Twenty patients, 2 to 15 years of age, were studied. Fifteen patients had the nephrotic syndrome and 5 had other renal disorders. Of 13 patients with nephrotic syndrome in relapse, serum transferrin and gamma-globulin concentrations were decreased in 10 and 11 patients, respectively. Transferrin levels correlated with the concentrations of total protein (r = 0.87, P less than 0.001), albumin (r = 0.91, P less than 0.001), and gamma-globulin (r = 0.78, P less than 0.001). Urinary electrophoretic analyses suggested that hypogammaglobulinemia was not explained simply by urinary losses. In order to determine whether decreased serum transferrin concentrations might limit immunoglobulin synthesis, the effect of hypotransferrinemic sera on lymphocyte proliferation in vitro was tested. At low concentrations of serum, tritiated thymidine uptake was directly proportional to the serum transferrin concentration (r = 0.86, P less than 0.001 at 0.02% serum concentration). Addition of transferrin completely restored the ability of patients' sera to support lymphocyte proliferation. These results suggest that hypotransferrinemia might influence in vivo lymphocyte function and immunity in the nephrotic syndrome.

Adolescent↗