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Biomedical subjects

S M Mauer

Publications and source records attributed to S M Mauer.

At least 127 records · Page 7Linked to original sources
PubMed1985

Improving survival in the very young renal transplant recipient.

Sixty-one patients ranging in age from 6 weeks to 30 months have undergone renal transplantation over a 19-year period. The overall survival is 80% with a 90% survival in those patients transplanted since 1980 (41 patients). Seventy-five percent of the original allografts have survived with 83% of the last 41 allografts surviving. The unique challenges presented by the very young renal transplant recipient are outlined along with those aspects of management felt to be most important in ensuring a successful outcome.

Age Factors↗
PubMed1985

Pseudohermaphroditism, glomerulopathy, and Wilms tumor (Drash syndrome): frequency in end-stage renal failure.

The sporadic concurrence of male pseudohermaphroditism and chronic glomerulopathy is associated with an extremely high risk of Wilms tumor. We report our experience with an infant who developed this triad (Drash syndrome) and review the 21 patients described in the literature, to emphasize the importance of early diagnosis and to suggest guidelines for management. The dysgenetic gonads are always intra-abdominal and carry a 20% to 30% risk for malignancy. The external genitalia are frequently ambiguous (77%); some children are phenotypically normal females. The glomerulopathy typically leads to end-stage renal failure in infancy; the subsequent death rate has, to date, been 68%. The clinical presentation of renal disease is variable and includes congenital nephrotic syndrome (14%) and infantile nephrotic syndrome (41%); 27% of patients develop proteinuria and renal insufficiency between the ages of 1 and 3 years. The high risk of Wilms tumor (55% in this review) mandates regular tumor surveillance, and prophylactic bilateral nephrectomy and gonadectomy once irreversible renal failure develops.

Disorders of Sex Development↗
PubMed1985

Wegener granulomatosis in pediatric patients.

Wegener granulomatosis is more easily recognized as a distinct clinical entity than other vasculitides because the initial clinical features frequently include granulomatous vasculitis of the upper and lower respiratory tract and glomerulonephritis. Although the disease has been lethal in the past, prolonged survival and avoidance of end-stage kidney disease can now be expected when cyclophosphamide therapy is introduced early in the course. We report four children with Wegener granulomatosis in whom the initial clinical findings suggested Henoch-Schönlein purpura. In two of the patients Wegener granulomatosis was not recognized until after end-stage kidney disease had developed. The course in these patients emphasizes the need for attention to even scant evidence of inflammation of the upper or lower respiratory tract in patients with glomerulonephritis. Appropriate diagnostic studies may then lead to recognition of Wegener granulomatosis and the prompt institution of appropriate treatment.

Adolescent↗
PubMed1985

Pediatric renal transplantation.

This article outlines the current status of pediatric renal transplantation and emphasizes a practical approach to patient management. It discusses two areas of renal transplantation in children in which results differ significantly between children and adults. These areas are renal transplantation in the very young child and transplantation in children with renal failure secondary to urologic disease.

Blood Transfusion↗
PubMed1985

A clinicopathologic study of forty-eight infants with nephrotic syndrome.

The clinical and histopathologic features of 48 children presenting with the nephrotic syndrome during the first year of life were analyzed. Proteinuria was discovered soon after birth to 3 months of age in 39 infants (congenital nephrotic syndrome), and nine infants had an infantile onset presenting between 4 and 12 months of age. Neither histologic parameters--microglomeruli, epithelial, or mesangial proliferation, focal segmental or global sclerosis, fibrinoid necrosis, or tubular microcysts--nor histologic classification--microcystic disease, mesangial proliferative glomerulonephritis, focal segmental glomerular sclerosis/hyalinosis-predicted the outcome. Rather, age at presentation was found to predict outcome: One of 39 infants with a congenital onset and seven of nine infants with an infantile onset underwent a complete remission (P less than 0.0001).

Child, Preschool↗
PubMed1985

Effects of mesangial localization of polyvinyl alcohols on glomerular basement membrane thickness.

We studied the effects of mesangial localization of polyvinyl alcohols (PVA) on glomerular basement membrane (GBM) thickness in inbred Lewis rats. To avoid possible influences of PVA redistribution after localization in liver, lung, and other organs, the kidneys of rats given PVA were transplanted into uninephrectomized normal rats. Normal kidneys transplanted into normal rats served as a control. GBM thickness at the time of transplantation was the same in PVA kidneys as in normal kidneys. However, by 18 weeks post-transplant GBM thickness was greater in PVA kidneys, and this increase was sustained at 30 weeks. Within the glomeruli of PVA kidneys, lobules with marked mesangial PVA accumulation had more marked GBM thickening than lobules with little or no PVA accumulation. It is concluded that changes within the mesangium can influence GBM thickness. Whether this represents a direct effect of mesangial architectural distortion, a consequence of local phlogistic activities such as the influx of macrophages into the mesangium of glomeruli with PVA localization, or the result of intraglomerular hemodynamic perturbations is unclear.

Animals↗
PubMed1985

De novo formation of immune complexes in human kidney allografts.

Cryostat sections of 11 rejected human renal grafts were selected for positive results in immunofluorescence tests. Immune complexes were detected in glomerular basement membrane (9 cases), tubular basement membrane (3 cases), and vessels (5 cases). Preincubation of the sections with FII of pooled human serum, but not of rabbit serum, prevented the staining of immune complexes for human IgG. These findings were interpreted by the assumption that most complexes under study were produced by reaction of the patient's altered IgG with the rheumatoid-like factor of IgG variety.

Antigen-Antibody Complex↗
PubMed1985

Improved results of multiple renal transplantation in children.

The results of 289 renal transplants in 223 children performed at the University of Minnesota during a 15-year period (1968 to 1982) were analyzed retrospectively. We found no statistically significant difference in graft and patient survival rates between 223 first, 50 second, and 13 third transplants. Children with greater than 1 year primary graft function had a significantly better second graft survival, especially when transplant nephrectomy was unnecessary before retransplantation. Children with less than 1 year primary graft function had a poorer second graft survival, particularly when the interval between transplants was less than 1 year. To determine the current risk-benefit factors in retransplantation in children, we compared two eras, our recent 7-year experience with our earlier 8-year experience. First graft survival remained essentially unchanged in both eras; however, graft survival rates of second transplants significantly improved, from 58% to 77% at 2 years (p less than 0.04). Two-year graft survival rates for nonidentical related kidneys improved from 73% to 82% and for cadaveric kidneys from 30% to 66%. Two-year graft survival rates for human leukocyte antigen (HLA)-identical kidneys were 100% in both eras. Better experience in patient care, abandonment of the practice of early retransplantation in children with rapid loss of the primary graft, changes in blood transfusion policy, and the use of better matched cadaveric kidneys probably account for our improved results. In conclusion, current risk-benefits for first and second transplants in children are the same. In our view, it is unwarranted to maintain children on open-ended long-term dialysis because the first graft has failed, although a period of maintenance dialysis to allow recovery from the complications of the first graft seems justified.

Adolescent↗
PubMed1984

Congenital nephrotic syndrome: evolution of medical management and results of renal transplantation.

We analyzed the clinical course, pathologic findings, and results of aggressive medical management and renal transplantation in 41 infants with onset of nephrotic syndrome in the first 3 months of life. All but one infant with congenital onset failed to thrive and had progressive renal insufficiency; 17 were given steroids or cytotoxic drugs or both, without benefit. Severe bacterial infections occurred in 85% of the infants, pyloric stenosis in 12%, gastroesophageal reflux in 8%, and thrombotic events in 10%. All children prior to the era of renal transplantation died before 4 years of age. The last 24 infants received aggressive medical management, which allowed renal transplantation in 17. Two-year patient and graft survival rates were 82% and 71%, respectively. There was no recurrence of the nephrotic syndrome in the children who underwent transplantation. All but one surviving infants has had normal or accelerated growth, although mean height for the group is 3.1 SD below the mean. School and social performance has been normal in 80%. Thus intensive medical therapy combined with renal transplantation offers a very good opportunity for survival with an acceptable quality of life for infants with congenital nephrotic syndrome.

Child Development↗
PubMed1984

Successful strategies for renal transplantation in primary oxalosis.

Eleven patients, aged 6 months to 47 years, with renal failure due to primary oxalosis, received renal allografts and were followed for 1 to 9 years. A specialized strategy for medical management included intensive pre-transplant hemodialysis and post-transplant long-term diuresis, administration of neutral phosphate, Mg++, and pyridoxine. Seven of ten living-related (LRD) transplants have good renal function, six with no biopsy evidence of renal oxalate deposition at up to 7 years after transplant. Two LRD graft losses from recurrent oxalosis, accompanied by massive secondary oxalate deposits, occurred in patients following endstage renal failure for over 3 years. A third LRD graft loss occurred following long-term (6 month) peritoneal dialysis in an infant. One cadaver transplant recipient has survived with recurrent oxalosis and poor graft function for 9 years. It is possible to perform successful renal transplantation in small children and adults with primary oxalosis and to completely prevent the deposition of oxalate in the renal allograft. Renal transplantation, with a strict medical protocol, would appear to be the initial treatment of choice for renal failure due to primary oxalosis.

Adult↗
PubMed1984

Structural-functional relationships in diabetic nephropathy.

Renal biopsies in 45 patients with insulin-dependent diabetes mellitus (IDDM) were examined by semiquantitative light microscopy and quantitative electron microscopic stereologic morphometry. In these 14 males and 31 females, aged 13-52 yr, who had had IDDM for 2.5-29 yr there was no strong relationship between either glomerular basement membrane (GBM) thickness or mesangial expansion and duration of IDDM. There was only a weak relationship between the thickness of the GBM and expansion of the mesangium. Thus, GBM thickening and mesangial expansion in IDDM occur at rates that often differ from one another and that vary greatly among patients. The clinical manifestations of diabetic nephropathy, albuminuria, hypertension, and decreased glomerular filtration rate related poorly or not at all to GBM thickening. In contrast, all light and electron microscopic measures of mesangial expansion were strongly related to the clinical manifestations of diabetic nephropathy, although in the absence of these clinical findings, it was not possible to predict the severity of any of the diabetic glomerular lesions. Mesangial expansion had strong inverse correlations with capillary filtering surface area density. It is hypothesized that mesangial expansion could lead to glomerular functional deterioration in IDDM by restricting the glomerular capillary vasculature and its filtering surface. However, capillary closure, glomerular sclerosis, and interstitial fibrosis could also contribute to the clinical manifestations of this disorder.

Adolescent↗
PubMed1984

A comparison of alternate day and daily steroid therapy in children following renal transplantation.

The effects of switching from daily steroid therapy (DST) to alternate day steroids (ADST) was reviewed in 28 children following kidney transplantation. Fifteen of the 28 children could be pair matched for age, sex, height and weight at transplant, time after transplant and renal function with children on DST. We found that catch-up growth occurred in children less than 10 years of age on low dose DST in the first 1 or 2 years post-transplant as long as major growth retarding factors such as renal failure or nephrosis were absent. Switching to ADST resulted in a significant increase in growth velocity in the second year on ADST compared to the parallel time in the matched pairs on DST. However, no significant increase occurred in the first year on ADST and for the total period of ADST which averaged 3.2 years. There was a similar risk of acute rejection episodes and rising serum creatinine levels in the matched ADST groups. However, late episodes of violent acute rejection leading to rapid graft loss were seen only in the ADST group, as long as 6 years post-transplant. Thus, ADST compared to low dose DST offers little growth advantage and, perhaps, this therapy should be reserved for children growing poorly after transplant.

Adolescent↗
PubMed1984

Renal allograft failure due to recurrent dense intramembranous deposit disease.

Dense intramembranous deposit disease (DIDD) almost universally recurs in renal allografts. However, the 29 previously reported cases suggest that recurrent DIDD rarely results in graft failure. We studied the clinical course and renal histology of the 6 patients with DIDD who have received renal allografts here since 1967. All patients had characteristic findings of DIDD in their native kidneys by light, immunofluorescence and electron microscopy. Seven grafts in 4 patients failed and histological evaluation showed that 5 of these allografts in 4 patients were lost due to recurrent disease. They all demonstrated marked mesangial proliferation with crescents but minimal acute interstitial or vascular changes of rejection. Patients with graft failure due to recurrent disease were male and developed recurrent nephrotic syndrome. The 2 patients with rapidly progressive glomerulonephritis (RPGN) in their native kidneys lost the transplanted kidney due to recurrent disease within 1 year. This study suggests that recurrence of DIDD in renal allografts is a more serious problem than previously appreciated, especially in patients with RPGN.

Adolescent↗
PubMed1984

Shwartzman reaction in streptozotocin-induced diabetic rats.

The possibility that experimental diabetes could prepare for the generalized Shwartzman reaction was investigated in female Sprague-Dawley streptozotocin-induced diabetic rats. After 48 hours, 1 week, and 9 weeks of diabetes, the rats were injected with 2 mg/kg of endotoxin, and the animals were sacrificed 2, 4, 8, and 24 hours after endotoxin. Ninety percent of the diabetic animals given endotoxin developed massive glomerular capillary fibrin deposition accompanied by marked decrease in platelet count. The age- and sex-matched nondiabetic control rats had no such changes. This marked susceptibility to endotoxin, previously only reported in pregnant rats, was present as early as 1 week of diabetes. The degree of glycemic control greatly influenced the susceptibility of diabetic rats to the generalized Shwartzman reaction. Only 28% of the diabetic animals given insulin once daily (4.6 +/- 0.3 units, mean +/- SEM) and maintaining a blood glucose level of 269 +/- 19 mg/dl developed glomerular thrombi. In contrast, the diabetic animals that did not receive insulin and had a blood glucose level of 617 +/- 21 mg/dl all developed fibrin thrombi. We conclude that the diabetic state in rats induces a unique susceptibility to the generalized Shwartzman reaction following a single injection of endotoxin, which varies with the severity of the diabetic state. Although the pathogenesis is unclear, this phenomenon may reflect abnormalities in the glomerular capillary wall and/or the coagulation system that may be important in the development of microvascular complications. Furthermore, this phenomenon may, in the animal model, mirror the increased risk of the diabetic patient to intravascular coagulation with bacterial sepsis.

Animals↗
PubMed1983

Failure to find amyloidosis in dogs treated with long-term intravenous insulin delivered by a totally implantable pump.

We examined tissues of seven non-diabetic mongrel dogs and four diabetic beagle dogs treated with constant insulin infusion via totally implantable pumps for from 210 to 880 days. Kidney and skeletal muscle tissue from all dogs were stained with Congo Red and thioflavin-T and appropriately examined. Kidney tissues from the beagle dogs were examined by electron microscopy. No amyloid deposits were found in any of these tissues. Thus, we cannot confirm an earlier report of amyloid occurring in dogs given long-term intravenous insulin. It is concluded that amyloidosis is not a necessary complication of long-term intravenous insulin infusion in dogs.

Amyloidosis↗