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Biomedical subjects

E Valderrama

Publications and source records attributed to E Valderrama.

12 recordsLinked to original sources
PubMed1992

Taurine attenuates renal disease in chronic puromycin aminonucleoside nephropathy.

Repeated administration of low doses of puromycin aminonucleoside (PAMN) to rats induces a proteinuric renal disease that resembles focal segmental glomerulosclerosis (FSGS). Reactive oxygen molecules may be involved in the progressive course of this nephropathy. Therefore we evaluated whether taurine, an endogenous antioxidant, could limit the extent of renal injury. Sprague-Dawley rats received low-dose injections of PAMN, 2 mg/100 g body wt, over a 12-wk period. Two groups were studied: 1) controls given tap water (n = 23), and 2) an experimental group that drank 1% taurine-supplemented water (n = 22). Taurine-treated nephrotic rats had a reduction in albuminuria, as assessed by the urinary albumin-to-creatinine ratio (26 +/- 4 vs. 44 +/- 4, P less than 0.0001). After 12 wk, creatinine clearance was 0.33 +/- 0.03 (experimental) vs. 0.17 +/- 0.03 ml.min-1.100 g body wt-1 (control) (P less than 0.001), and inulin clearance (n = 6 pairs) was 0.26 +/- 0.04 (experimental) vs. 0.13 +/- 0.02 ml.min-1.100 g body wt-1 (control) (P less than 0.025). Administration of taurine reduced the percentage of segmentally sclerosed glomeruli (9.8 +/- 1.7 vs. 16.2 +/- 1.8%, P less than 0.02) and the tubulointerstitial injury score (1.36 +/- 0.19 vs. 2.61 +/- 0.25, P less than 0.0025) in experimental vs. control rats. Taurine treatment normalized the elevated renal cortical malondialdehyde level in rats with PAMN nephropathy (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

IgA nephropathy in a child with human immunodeficiency virus type 1 infection.

Infection with the human immunodeficiency virus type 1 (HIV-1) can cause a spectrum of renal disease, termed acquired immunodeficiency syndrome (AIDS) nephropathy. The most common clinical manifestations of kidney involvement in HIV-1-infected patients are proteinuria and/or nephrotic syndrome, and the histopathological pattern usually reveals focal segmental glomerulosclerosis. We describe an 8-year-old child with AIDS who presented with recurrent gross hematuria. A kidney biopsy demonstrated IgA nephropathy. This unique case indicates that the range of kidney disease in HIV-infected children may be broader than originally thought, and that these patients warrant a complete evaluation of any renal abnormality.

Biopsy↗
PubMed1991

Nephrotoxicity of allopurinol is enhanced in experimental hypertension.

Hyperuricemia is present in 20-40% of pediatric and adult patients with essential hypertension. This metabolic abnormality may represent an additional risk factor for the development of cardiovascular disease. Therefore, we performed the following studies to determine 1) whether hyperuricemia is more prevalent in the spontaneously hypertensive rat (SHR) and 2) whether allopurinol treatment has a beneficial effect on the development of hypertension in this strain, based on its capacity to lower the serum uric acid concentration and to act as an antioxidant agent. SHR and control Wistar-Kyoto (WKY) rats were assigned to two groups, one given tap water to drink and the other provided water containing allopurinol (400 mg/l) to furnish an approximate daily dose equal to 100 mg/kg body wt. This treatment was maintained for 15 weeks. The serum uric acid levels were similar in untreated SHR and WKY rats (1.85 +/- 0.10 versus 1.66 +/- 0.14 mg/dl; p = 0.28). In the control WKY rat strain, allopurinol therapy did not adversely affect weight gain or hematocrit and did not cause an increase in mortality. It resulted in a moderate decrement in kidney function (creatinine clearance: allopurinol-treated group 0.32 +/- 0.09 versus control group 0.46 +/- 0.04 ml/min/100 g body wt, in conjunction with mild-to-moderate tubulointerstitial inflammation (allopurinol-treated group 0.9 +/- 0.4 versus control group 0).(ABSTRACT TRUNCATED AT 250 WORDS)

Allopurinol↗
PubMed1990

Molecular phenotype of a pediatric small round cell tumor.

Molecular probes were used to characterize an unusual small round cell abdominal tumor arising from the fallopian tube of a 15-year-old girl. DNA and RNA extracted from the tumor and adjacent normal tissue was subjected to Southern and Northern blot analysis using a variety of different probes. N-myc oncogene RNA was greatly expressed in the tumor, but was not expressed in normal tissue or amplified in chromosomal DNA. Insulin-like growth factor II RNA was similarly overexpressed in the neoplasm, but not in normal tissue. While histopathologic studies could not distinguish between a neuroectodermal neoplasm and Wilms' tumor, electron microscopy and the pattern of gene expression was most consistent with Wilms' tumor.

Adolescent↗
PubMed1990

The renal functional and structural consequences of corticosteroid and angiotensin-converting enzyme inhibitor therapy in chronic puromycin aminonucleoside nephropathy.

Glomerular diseases are characterized by increased urinary protein excretion. Treatment of this abnormality frequently involves administration of corticosteroids and angiotensin-converting enzyme inhibitors. There has been much recent interest in the potential impact of these drugs on progressive renal dysfunction, since they have opposing effects on intraglomerular hemodynamics. Therefore, we investigated the effect of methylprednisolone or captopril treatment on animals with chronic puromycin aminonucleoside nephropathy. In rats given a single injection of puromycin aminonucleoside, 15 mg/100 g body weight, both methylprednisolone and captopril significantly reduced proteinuria at 6 months [83 +/- 14 untreated (n = 7), 34 +/- 6 with methylprednisolone (n = 8), and 6 +/- 1 mg/24 h with captopril (n = 5), P less than 0.001]. Segmental glomerulosclerosis occurred with equal frequency in the untreated (7.8 +/- 2.3%) and methylprednisolone-treated rats (5.0 +/- 1.11%), but was significantly reduced by the administration of captopril (1.0 +/- 0.5%, P less than 0.001). We conclude that in chronic puromycin aminonucleoside nephropathy, treatment with corticosteroids reduces proteinuria without increasing the incidence of segmental glomerulosclerosis. Therapy with an angiotensin-converting enzyme inhibitor substantially decreases proteinuria and lessens the severity of glomerular scarring.

Adrenal Cortex Hormones↗
PubMed1990

Kearns-Sayre syndrome presenting as renal tubular acidosis.

Renal tubular acidosis and tetany were the 1st manifestations of Kearns-Sayre syndrome in a 5-year-old child. Subsequently, he developed progressive external ophthalmoplegia, ptosis, retinopathy, heart block, and endocrinopathy. There was a 7.5-kb deletion of mitochondrial DNA documented in muscle, kidney, skin fibroblasts, and leukocytes, providing evidence for a multisystem mitochondrial cytopathy.

Acidosis, Renal Tubular↗
PubMed1990

Acute interstitial nephritis in adolescents and young adults.

We have reviewed our experience with acute interstitial nephritis (AIN) in pediatric patients over the 3-year period from 1985 to 1988. We encountered 7 new cases of AIN in this interval and it was seen in 7% of kidney biopsies performed during this time of study. The clinical presentation was very nonspecific and included fever (100%), gastrointestinal complaints (57%) and rash (28%). Laboratory findings on admission included elevated erythrocyte sedimentation rate (100%), anemia (70%), pyuria (57%) and abnormal renal ultrasound (86%). Associated systemic diseases were observed in 4 patients. AIN was severe enough to necessitate treatment with hemodialysis in 42% of the cases. Corticosteroid therapy was used in 6 patients with a favorable response in all but 1 case. While 6/7 patients manifested complete recovery, 1 adolescent who may have had pre-existing renal disease had persistent chronic renal failure (estimated GFR, 25 l/min/1.73 m2). We have concluded that: (1) AIN is a relatively common disease in pediatric practice; (2) it can be severe enough to necessitate dialysis therapy, and (3) AIN often occurs in children with systemic disorders that may be associated with immunologic disorders.

Adolescent↗
PubMed1990

Hepatitis-B-associated glomerulonephritis: pathology, pathogenesis, and clinical course.

Hepatitis-B-associated glomerulonephritis (HBGN) is a distinct entity occurring frequently in hepatitis-B-prevalent areas of the world. The disease affects both adults and children who are chronic hepatitis-B-virus (HBV) carriers with or without a history of overt liver disease. The diagnosis is established by serologic evidence of HBV antigens/antibodies, presence of an immune complex glomerulonephritis, immunohistochemical localization of 1 or more HBV antigens, and pertinent clinical history, when available. In this study we present clinicopathologic and follow-up findings in 12 patients (7 children, 5 adults) with hepatitis-B-associated glomerulonephritis. Twelve patients provided 15 renal biopsies and 1 specimen of kidney tissue, obtained at autopsy; these were examined by light microscopy, electron microscopy, and immunohistochemical methods. Membranous glomerulonephritis (MGN) with or without mesangial proliferation was noted in 7 biopsies, mesangiocapillary (membranoproliferative) glomerulonephritis (MCGN) in 5 biopsies, and proliferative glomerulonephritis with or without membranous changes in 2 biopsies. Tubulointerstitial changes were minimal except in 3 adults, in whom they were attributable to arterionephrosclerosis. Ultrastructural findings included the presence of considerable amounts of focal or diffuse granular electron-dense deposits in the glomeruli, in the subepithelial, subendothelial, and mesangial locations, occasionally destroying or replacing the lamina densa of the basement membrane. Variable mesangial proliferation was also observed, with interposition, with focal irregular reduplication of the basement membranes and rare clusters of spherical particles, probably representing viral particles in the deposits. In addition, granular deposits along tubular basement membranes were seen in 1 case. The glomerular deposits stained for 2 or more immunoglobulins, the predominant one being IgG, and variably also for complement components (C3, C4 and C1q). Hepatitis B viral antigens (HBsAg, HBcAg, HBeAg) were demonstrated using acid elution techniques in the deposits in all biopsies where frozen tissue was available, singly or in a variety of combinations and intensities. There were deposits of IgG, C3, C1q, and HBsAg along the tubular basement membranes in 1 case. Follow-up biopsies in 2 cases, 2 and 5 years apart, showed a transformation from a diffuse MGN to MCGN with segmental membranous features. Follow-up biopsy after 3 years in the third patient, who went into clinical remission, revealed partially resolving glomerular lesions. Renal lesions secondary to chronic liver disease, parasitic diseases, certain tropical nephropathies, and lupus nephritis are some of the diseases that may morphologically resemble HBGN. Recognition and differentiation of HBGN from other entities may have significant prognostic and therapeutic implications.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1979

Congenital unilateral ichthyosis in a newborn.

Ichthyosiform erythroderma is a rare phenomenon occurring in about 1/300,000 live births. Congenital unilateral ichthyosis, described in this case report, is a clinical variant of ichthyosis. Only five previous cases have been reported. In the patient described in this report, superimposed infection of the affected skin developed. Her immunologic system was intact. She manifested failure to thrive, in spite of an adequate caloric intake, and markedly delayed psychomotor development. This patient also demonstrated absorption from the affected dermis of topically applied urea hydrophilic base ointment. She died before her first birthday.

Female↗
PubMed1979

The Ask-Upmark kidney in a premature infant.

A premature infant with segmental hypoplasia of one kidney is reported. Since 1929 when Ask-Upmark first reported this renal anomaly and its association with hypertension, the nature of the lesion has remained in doubt. The question whether it is acquired post-natally or whether it is a developmental mal-formation has not been resolved. The case which we now report clearly documents the prenatal development of the lesion as well as its association with arrested nephrogenesis and the presence of abnormal vasculature. The cause of these changes is not clear, but it is suggested that ureteral reflux was present.

Humans↗
PubMed1978

Pulmonary blastoma. Report of two cases in children.

Pulmonary blastoma is a rare tumor of the lung. Although it has been stated that this is predominantly a tumor of adults, a review of the 42 cases published to date reveals that it is a disease which occurs with some frequency in children. The tumor is relatively benign compared to pulmonary carcinosarcoma. Of the eight cases previously described in children, three are known to have survived and to be free of disease 10 months, 3 and 8 years after surgical resection. We report two additional cases of pulmonary blastoma in children followed for 34 and 26 months without any evidence of recurrence or metastases.

Adolescent↗