PubMed Health⌕ Search

Biomedical subjects

A L Friedman

Publications and source records attributed to A L Friedman.

At least 55 records · Page 3Linked to original sources
PubMed1994

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↗
PubMed1992

Prevention of autoimmune diabetes in the BB rat by intrathymic islet transplantation at birth.

Spontaneous diabetes in the BioBreeding (BB) rat, like human type I diabetes, results from the destruction of pancreatic islets by autoreactive T lymphocytes recognizing beta cell-specific antigens. T cell tolerance is in part mediated by interactions of maturing thymocytes with antigens expressed in the thymic microenvironment; islets were therefore implanted into the thymus of neonatal diabetes-prone BB rats to determine whether exposure of T cell precursors to beta cell antigens could influence the development of diabetes. This treatment completely prevented diabetes and insulitis in the native pancreas. The effect may be the result of specific modulation of diabetogenic T cells maturing in an islet-bearing thymus.

Animals↗
PubMed1992

A recent decrease in the time to development of monomorphous and polymorphous posttransplant lymphoproliferative disorder.

We have noted a decrease in the time to development of posttransplant lymphoproliferative disorder (PTLD) over the last two and one-half years in our multiorgan transplant program. From February 1965 until December 1990, 1622 transplants were performed including 1489 kidneys (KTxp), 87 livers (LTxp), and 46 pancreata. Between February 1965 and July 1988 (group 1), there were 1260 transplants performed and nine cases of either monomorphous PTLD (M-PTLD, n = 8) or polymorphous PTLD (P-PTLD, n = 1) were diagnosed. The mean time to development of PTLD was 163 +/- 128 weeks, all after KTxp. Five of these nine patients received haploidentical living-related grafts. All patients had presented with advanced disease, none had transplant nephrectomy, and all died of their disease. Between July 1988 and December 1990 (group 2), 362 transplants were performed, and four cases of M-PTLD and three cases of P-PTLD were recognized. Of the seven cases of PTLD in group 2, six developed within 90 days posttransplant (early PTLD). The mean time to development of PTLD was 11 +/- 16 weeks. This was significantly earlier than group 1 (P less than .01). Four of the five cases after KTxp had a 1 or 2 DR-matched donor. Five of these seven patients had serological evidence of recent Epstein-Barr Virus infection, and four of these five had received OKT3 and then developed early PTLD. In group 2, three patients are alive 7-15 months after KTxp nephrectomy, the remaining four have died. We hypothesize that risk factors for the development of PTLD may include heavy immunosuppression, including the use of OKT3, good DR matching, and active EBV infection. Treatment should include graft removal, if applicable, and reduction or cessation of immuno-suppression.

Herpesvirus 4, Human↗
PubMed1992

Vesicoureteric reflux in sibships.

A family with 4 of 6 siblings manifesting vesicoureteric reflux is presented. Reflux could not be demonstrated in preceding and succeeding generations in this family. Genetic analysis suggests that most instances of familial vesicoureteric reflux arise secondary to expression of autosomal dominant single genes with incomplete penetrance. Screening of sibships for reflux might be most appropriately carried out by urine analysis, culture and ultrasound imaging.

Child↗
PubMed1992

Effects of prolonged growth hormone administration in rats with chronic renal insufficiency.

Recombinant hGH (rhGH) augments short-term linear growth in experimental animals and children with chronic renal failure. Significant augmentation of final height, however, requires prolonged growth hormone therapy during years of growth. The effects of prolonged rhGH treatment on linear growth, progression of renal dysfunction, and longevity in the setting of renal insufficiency are unknown. We examined at 9, 15, and 25 wk growth in length and weight, glomerular filtration rate measured by inulin and creatinine clearance, food efficiency (g ingested/weight gained), and survival in treated (U-GH) and untreated (U) 75% nephrectomized uremic rats and in treated (S-GH) and untreated (S) sham-operated rats. We also measured kidney weight to body weight ratios at the time the rats were killed. Treatment was rhGH 1.0 mg s.c. three times a week during wks 4-12 of life. Length of U-GH rats was greater than that of U rats (p less than 0.05) at 15 and 25 wk (but not at 9 wk) and equal to that of S rats throughout the study. Length of S-GH rats exceeded that of S rats. At 9 wk, weight was diminished in both U and U-GH rats (p less than 0.05) versus S and S-GH rats; by 15 wk, U-GH rat weight was equal to S rat weight. Glomerular filtration rate measured by creatinine was markedly reduced in U and U-GH rats and did not increase in response to prolonged rhGH in either U-GH or S-GH rats. Diminished food efficiency of U rats versus S rats (p less than 0.05) was not improved significantly by rhGH.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Renal transplantation at the University of Pennsylvania Medical Center: an update of results in the cyclosporine era.

This chapter presents a summary of living-related, living-unrelated, and cadaver renal transplantation performed at the University of Pennsylvania Medical Center between January 1984 and October 1992. Over the past 9 years, 895 patients (557 males, 338 females, mean age 42 yrs) received 942 renal transplants; 599 patients received kidneys from cadaver donors (n = 627) and 296 patients received kidneys (n = 315) from living donors of all types. During this period, 151 patients were retransplanted, sometimes more than once (159 total retransplants, 124 secondary grafts, and 35 third or more transplants). An analysis of patient ant graft survival rates (calculated by actuarial methods) for different categories of transplant recipients was performed. Black recipients, as a racial subcategory, had the poorest graft outcome, especially when followed over the long term. Graft survival rates for Black recipients who were retransplanted with cadaver grafts were even worse and were noted to be similar to the diabetic population that received cadaver retransplants (66% vs 62% at 1 yr and 32% vs 25% at 5 yrs). Diabetic recipients of living-donor transplants had excellent graft survival results, similar to nondiabetic, living-donor recipients (patient survival rates 98% and 92% vs 97% and 92% at 1 and 5 yrs; graft survival rates 92% and 82% vs 92% and 82% at 1 and 5 yrs). HLA-identical recipients of first cadaver grafts demonstrated the best outcome in the entire cadaver series (graft survival rates 91% and 83% at 1 and 5 yrs, respectively). HLA-identical recipients of second or more cadaver grafts had poorer results than expected (50% graft survival at 1 yr) despite a 100% patient survival rate. HLA-identical recipients of living-related grafts had the best graft survival rates (96% at 1 yr and 94% at 5 yrs) and superior graft survival rates for retransplanted grafts as well (100% at 1 and 5 yrs). We conclude that in the last decade, patient and graft survival rates for cadaveric and living-donor renal transplants have improved dramatically relative to the results obtained in the pre-CsA era. Long-term graft survival in Black recipients remains lower than in other races, suggesting the need to analyze other factors to explain poorer graft survival in this recipient population. Results in diabetic recipients continue to be excellent at our center, encouraging the continuation of our aggressive approach to try to transplant diabetics as early as possible, particularly when a living donor is available.

Academic Medical Centers↗
PubMed1991

Progressive renal insufficiency in methylmalonic acidemia.

Methylmalonic acidemia is a heterogeneous inborn error of propionate metabolism. Therapy frequently includes a low-protein diet to minimize precursors of methylmalonic acid (MMA) and reduce its concentration in body tissues. Renal dysfunction in these patients is increasingly recognized. Tubulointerstitial disease has been found in the small number of renal biopsy specimens from young children previously reported by others. We describe an 18-year-old patient with the mut- form of the disease who developed renal dysfunction despite the use of a low-protein diet. Tubulointerstitial injury was documented by renal biopsy. The patient had no risk factors associated with established causes of chronic tubulointerstitial nephropathy (CTIN). We postulate that methylmalonyl-CoA and/or its precursors (propionyl-CoA, odd-chain fatty acids), may be capable of producing CTIN. We speculate that prevention of renal injury may require lower tissue levels of MMA and its precursors than those required for prevention of ketoacidosis.

Adolescent↗