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At least 883 records · Page 49Linked to original sources
PubMedDate not supplied

[Primary nephrotic syndrome. Follow-up of 202 pediatric patients].

Two hundred and two children with primary nephrotic syndrome were studied. Clinical features at onset and evolution were studied and correlated with microscopic findings and response to treatment. Histologic type and steroid-response were correlated with urinary protein selectivity in a group of them. Mean follow-up (by the same group of nephrologists) was 6.6 years; 22% were followed for over 8 years. The presence of hematuria, hypertension and renal failure at onset and during the course of the disease were evaluated. 122 patients were steroid-responders, 64 of them had frequent relapses. After a mean follow-up of 6.3 years, 81% were on remission; 14% had transient proteinuria, and 5% developed persistent proteinuria with late resistance to steroid therapy. 80 children were steroid-resistant. Their mean follow-up period was 5.5 years (1.0-10.5 years). 65 of them were biopsied: 12 had minimal glomerular change; 27 focal and segmental sclerosis. 9 membrano-proliferative glomerulonephritis, 4 focal and global sclerosis, 4 membranous nephropathy, 4 diffuse mesangial proliferation, 2 diffuse mesangial sclerosis and 2 were not classifiable. Hematuria had a prognostic value only when it was permanent or macroscopic. Urinary protein selectivity was measured in 43 patients, and C3 in 81; hypocomplementemia was found only in the 9 children with membranoproliferative glomerulonephritis. 8 children had tubular dysfunction: 7 had focal and segmental sclerosis, and 1 diffuse mesangial sclerosis; glycosuria and aminoaciduria were present in all 8, but only 4 of them had deficient urinary acidification. Secondary infections appeared in 42 patients; 19 were steroid-resistant and 23 steroid-responders, 17 of them showed frequent-relapses, 3 had localized thromboembolism. 23 children went into chronic renal failure and 17 of them died, 13 in end-stage renal failure and 4 because of complications. Their first biopsies showed minimal change in 1, focal and segmental sclerosis in 8, membranoproliferative glomerulonephritis in 3, diffuse mesangial proliferation in 1, diffuse sclerosis in 2, and 2 were not classifiable.

Adolescent↗
PubMedDate not supplied

Fanconi's syndrome in a dog with primary hypoparathyroidism.

An 11-year-old castrated male mixed breed dog was referred for evaluation of muscle twitching, polyuria, polydipsia, anorexia, and periocular alopecia. Primary hypoparathyroidism was diagnosed by documenting decreased serum concentrations of parathyroid hormone and ionized calcium. Neurological, gastrointestinal, and dermatological signs resolved after calcium repletion. Initially, 1,25-dihydroxycholecalciferol PO was required to correct the hypocalcemia. Dihydrotachysterol, in combination with oral calcium supplementation, was used for long-term maintenance of normal serum calcium concentration. Aminoaciduria, glucosuria, and hyperchloremic metabolic acidosis were consistent with a diagnosis of Fanconi's syndrome. This diagnosis was further supported by the presence of hypokalemia and increased urinary fractional excretion of sodium, potassium, calcium, phosphorus, and magnesium. Renal tubular dysfunction resolved after oral supplementation with calcium and vitamin D3. Fanconi's syndrome in this dog may have been caused by decreased serum concentration of 1,25-dihydroxycholecalciferol, which was secondary to decreased parathyroid hormone production.

Animals↗
PubMed1990

Renal tubular acidosis.

Renal tubular acidosis refers to a group of disorders that result from pure tubular damage without concomitant glomerular damage. They could be hereditary (primary) or acquired (secondary to various disease states like sickle cell disease, obstructive uropathy, postrenal transplant, autoimmune disease, or drugs). The hallmark of the disorder is the presence of hyperchloremic metabolic acidosis with, or without, associated defects in potassium homeostasis, a UpH greater than 5.5 in the presence of systemic acidemia, and absence of an easily identifiable cause of the acidemia. There are three physiologic types whose basic defects are impairment of or a decrease in acid excretion, i.e., type 1 (dRTA); a failure in bicarbonate reabsorption, i.e., type 2 (pRTA); and deficiency of buffer or impaired generation of NH4+, i.e., type 4 RTA. Several pathophysiologic mechanisms have been postulated for these various types. pRTA is the least common of all in the adult population. It rarely occurs as an isolated defect. It is frequently accompanied by diffuse proximal tubule transport defects with aminoaciduria, glycosuria, hyperphosphaturia, and so forth (Fanconi syndrome). dRTA is associated with a high incidence of nephrolithiasis, nephrocalcinosis, osteodystrophy, and growth retardation (in children). Osteodystrophy also occurs in pRTA to a lesser degree and is believed to be secondary to hypophosphatemia. Patients with type 4 RTA usually have mild renal insufficiency from either diabetes mellitus or interstitial nephritis. Acute bicarbonate loading will result in a high fractional excretion of bicarbonate greater than 15% (FEHCO3- greater than 15%) in patients with pRTA, but FEHCO3- less than 3% in patients with dRTA. Type I patients will also have a low (U - B) PCO2 with bicarbonate loading. They are also unable to lower their urine pH to less than 5.5 with NH4Cl loading. The treatment of these patients involves avoidance of precipitating factors when possible, treatment of underlying disease, correction of electrolyte imbalance, particularly hypokalemia and hyperkalemia, and most importantly, the use of alkali. This will prevent or reduce all the various complications.

Acid-Base Equilibrium↗
PubMedDate not supplied

Effect of polyaspartic acid on CdCl2-induced nephrotoxicity in the rat.

We produced an animal model of CdCl2 nephrotoxicity in rats, and treated them with polyaspartic acid (PAA) to prevent renal damage. Male Sprague-Dawley (SD) rats (190-200 g) were used to induce proximal renal tubular damage by daily injection of CdCl2 3.0 mg/1,000 g body wt for 2 wk. CdCl2-exposed SD rats exhibited significant increases in urine volume, urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG), alanine aminopeptidase (AAP), and fractional excretion of sodium (FENa) and a decrease in the percentage of tubular reabsorption of phosphate (%TRP). Of these indicators of proximal tubular function, AAP and %TRP are more sensitive than NAG or FENa. No glycosuria or aminoaciduria, however, were observed. PAA markedly improved these indicators of proximal tubular function. Daily urinary protein excretion and creatinine clearance, on the other hand, did not change after administration of PAA. Cd concentrations in the cortex were 3 times higher than in the medulla, however, there were no differences between Cd-treated rats and PAA-treated rats. Our animal model is an excellent one for determining the effect of cadmium on renal proximal tubule damage. PAA appears to be useful in the treatment of CdCl2 nephrotoxicity.

Acetylglucosaminidase↗
PubMed1992

Familial progressive renal tubulopathy.

We report herein data on 6 male patients with progressive tubulopathy. These patients belonged to two families: the propositus, his father, a paternal first cousin, two paternal uncles, and a maternal uncle. A 7-year-old proband had mild proteinuria (1 g/day), consisting of beta 2-microglobulin, alpha 1-microglobulin and lysozyme, and aminoaciduria. Glycosuria and acidosis were absent. A 38-year-old father had mild proteinuria (2 g/day), including low-molecular-weight protein. Hypokalemia, hypophosphatemia, glucosuria, phosphaturia, aminoaciduria, and reduced urinary concentrating ability were also present. The other 4 affected family members also had low-molecular-weight proteinuria, detected by screening for beta 2-microglobulin. In addition, there were several abnormalities; aminoaciduria in all 6, phosphaturia in 4 of 6, hypercalciuria in all 6 and glycosuria in 2 of 6 patients. Tubular dysfunction was more severe in the older subjects, hence, the disease seems to progress with age. Familial low-molecular-weight proteinuria is apparently a progressive disease linked to a X-linked or to an autosomal dominant inheritance.

Adolescent↗
PubMed1980

Lowe's syndrome.

The histopathological manifestations in four eyes from two male patients with the oculo-cerebro-renal syndrome of Lowe included a small, discoid, cataractous lens, peculiar capsular and epithelial changes with aberrant formation of collagenous fibrous tissue, polar lenticular changes with anterior vitreous condensation, embryonic anterior chamber angle with anterior displacement of rudimentary ciliary processes, segmental hypoplasia of iris dilator muscle, and Lange's folds with peripheral retinal cystoid changes. Additional findings in one of the cases included bilateral corneal keloids, vitreous organization, hyalinized retinal vessels, and mild gliosis. We suggest that the congenital ocular abnormalities in Lowe's syndrome are related to an as yet unidentified, inherited enzymatic and/or biochemical defect, and that they progress further because of an abnormal aqueous humour environment. The role of aminoaciduria and mucopolysaccharidosis in the pathogenesis of systemic and ocular defects is discussed in the light of recent investigations.

Anterior Chamber↗
PubMed1978

On the development of glycine transport systems by rat renal cortex.

The initial uptake of glycine by renal cortical slices from newborn Sprague-Dawley and Long-Evans rats is the same as that observed in adult tissues. Both newborn and adult tissue possess similar high and low affinity glycine transport systems which require an examination of velocity measurements over a wide range of concentration (0.02--50.0 mM) for their discernment. Initial rates of glycine uptake by isolated renal tubule fragments from newborn and adults are similar at a physiological substrate concentration but at high glycine levels there appears to be a decrease in velocity of uptake (V) associated with the high Km system in the young. Whatever preparation of renal cortex is studied, there is a consistent finding that immature tissue is able to accumulate much higher intracellular levels of glycine than the adult, a finding consistent with slower efflux from the cell. An interpretation of the etiology of physiologic aminoaciduria in young animals should take this into account.

Aging↗
PubMed1991

Mechanisms of hypophosphatemia in humans with heatstroke.

Hypophosphatemia is common in heatstroke, but little is known about its mechanism. We investigated 10 consecutive patients with heatstroke (mean age 58 +/- 2 yr) whose mean rectal temperature at admission was 42.3 +/- 0.2 degrees C. Eight patients presented with hypophosphatemia [0.48 +/- 0.08 mmol/l, normal range (NR) 0.8-1.4 mmol/l], associated with increased fractional excretion of phosphate (19.8 +/- 6.4%, NR 6-20%) relative to plasma phosphate levels and reduced renal threshold for phosphate (0.55 +/- 0.08 mmol/l glomerular filtrate, NR 0.8-1.4 mmol/l). Plasma parathyroid hormone (75.0 +/- 5 pmol/l) and calcium (2.24 +/- 0.02 mmol/l) levels and fractional excretion of calcium were normal (1.66 +/- 0.27%). There was no evidence of uricosuria or aminoaciduria, and only one patient had glucosuria. Arterial carbon dioxide was decreased in eight patients (28 +/- 1.1 Torr); however, none had elevated blood pH (7.35 +/- 0.02). The results suggest that heatstroke-related hypophosphatemia is associated with abnormal phosphaturia independent of the parathyroid hormone level, and there is no evidence of tubular dysfunction.

Aged↗
PubMed1980

Laboratory and histological similarities between Wilson's disease and rats with copper toxicity.

Rats were injected intraperitoneally with copper-lactate daily for over 160 days (total dose of 30 mg copper in each animal). At 120 to 160 days of copper administration, animals developed symptoms similar to those of Wilson's disease, i.e., kidney functional disturbances, proteinuria, aminoaciduria, decreased blood ceruloplasmin oxidase activity and increased urinary copper excretion. Cirrhosis was found in some animals. Tubular necrosis of the kidneys, liver fibrosis and tigrolysis of thalamic nerve cells were also found. Copper depositions were observed in liver parenchymal cells, renal tubular epithels, thalamus glia cells and on the Descemet's membrane of the cornea. The similarities between induced copper- intoxication in rats and Wilson's disease are discussed.

Animals↗
PubMedDate not supplied

[Nephrotoxicity of ifosfamide with special reference to Fanconi Syndrome].

UNLABELLED: The article is a case presentation of Fanconi syndrome in a patient treated with high doses of ifosfamide. ifosfamide nephrotoxicity relates to glomerular and tubular disfunction. Tubular disfunction type 2 (Fanconi Syndrome) is observed most often. In this syndrome hypophosphatemia, hyperphosphaturia, glucosuria, polyuria, aminoaciduria, hypokalemia and tubular acidosis are present. The treatment consists of electrolyte supplementation and acidosis reduction. Nephrotoxicity risk factors are: total ifosfamide doses and age under 3 years. Early diagnosis is possible by estimating b2 microglobulin and retinal binding protein. Normally used parameters of renal function are insufficient. MATERIAL AND METHODS: case report - N. W - 13-year-old patient with a skin's tumour was treated in our clinic. Euro Ewing-99 protocol with 100.8 g/m2 of ifosfamide was applied for 18 months. During treatment serum electrolytes, urea, creatinine and creatinine clearance were normal. 6 months after treatment a metastasis in the lung was detected. RESULTS: Fanconi Syndrome symptoms were noticed before introduction of chemotherapy. After treatment with small doses of ifosfamide (4.5 g/m2) the disorders became severe. For this reason, nephrotoxic cytostatics were excluded from further treatment, decreasing its efficiency. CONCLUSIONS: 1. Renal complications of ifosfamide may appear after treatment completion. Monitoring of renal function parameters is necessary during and after treatment. 2. When protocols with cyclophosphamide (less nephrotoxic than ifosfamide) prove to be of similar efficiency, this treatment could be an alternative for patients' with renal disfunction. 3. Patients with completed ifosfamide treatment shall be qualified for repeated chemotherapy carefully due to high-risk of renal disfunction.

Acute Kidney Injury↗
PubMed1980

Urine screening for aminoacidopathies: is it beneficial? Results of a long-term follow-up of cases detected bny screening one millon babies.

One million 6-week-old infants were screened for aminoacidurias and the long-term follow-up analyzed to assess the benefits of the screening program. Apart from phenylketonuria, now normally detected by blood screening at five days, the most frequent abnormalities identified were cystinuria, histidinemia, Hartnup disease, and iminoglycinuria. Other disorders occurred less frequently than 1:100,000. Early diagnosis provided unequivocal clinical benefit only for phenylketonuria. There was probable benefit to patients with cystinuria, homocystinuria, argininosuccinic aciduria, and to some patients with Hartnup disease. However, benefit of early diagnosis in these disorders, of which the combined incidence was 1:10,000, was not clear-cut; for example, in 68 cystinuric children, four had already developed renal stones despite close medical supervision and a regimen of increased fluid intake to the limits of tolerance. No patient detected with any other condition benefited, either because the condition appeared benign and was not treated, or because the disorder was serious or lethal and there was a bad outcome despite early diagnosis and treatment. Existing urine screening programs should explore the incidence and clinical significance of further biochemical abnormalities detectable in the newborn infant, but there is no indication at present for the initiation of new urine screening programs designed to detect only aminoacidurias.

Amino Acid Metabolism, Inborn Errors↗
PubMed2004

Fanconi's syndrome in HIV+ adults: report of three cases and literature review.

UNLABELLED: We diagnosed Fanconi's syndrome (phosphate depletion and dysfunction of the renal tubules) in three HIV(+) patients. This was temporally related to their HIV treatment. Physicians caring for patients with HIV should recognize the association of this rare syndrome with antiretroviral medications and monitor their patients carefully. INTRODUCTION: Fanconi's syndrome is caused by increased excretion of phosphate, glucose, amino acids, and other intermediary metabolites, and can result in osteomalacia. MATERIALS AND METHODS: We diagnosed this syndrome in three HIV(+) patients. RESULTS: The first was a 43-year-old woman referred for multiple painful stress fractures. She demonstrated hypophosphatemia, metabolic acidosis, phosphaturia, glucosuria, and generalized aminoaciduria. These abnormalities resolved with oral phosphate replacement and discontinuation of the antiretroviral medication tenofovir. The second patient was a 39-year-old man with hypophosphatemia and bone pain. His symptoms improved with discontinuation of adefovir and supplementation of phosphate, potassium, and calcitriol. The third patient was a 48-year-old man who presented with symptomatic tetany caused by hypocalcemia (total serum calcium of 6.5 mg/dl [8.5-10.5 mg/dl]). Nine months before presentation, he had been treated with cidofovir for retinitis caused by cytomegalovirus. With calcium, phosphate, potassium, and calcitriol therapy, his laboratory abnormalities improved substantially, although he continues to require daily electrolyte replacement. CONCLUSIONS: Each patient demonstrated generalized renal tubular dysfunction temporally related to treatment with antiretroviral drugs. The mechanism responsible for these abnormalities is not known; however, physicians caring for patients with HIV disease should recognize the association of Fanconi's syndrome with antiretroviral medications and monitor susceptible patients to prevent potential skeletal and neuromuscular complications.

Adenine↗
PubMed1995

Heavy metal mediated inhibition of rBAT-induced amino acid transport.

rBAT, a protein which is located in the brush border membranes of intestine and renal proximal tubule cells, was recently shown to induce electrogenic countertransport of neutral and dibasic amino acids after its expression in Xenopus oocytes. Here, we studied the effects of heavy metals on rBAT induced amino acid transport in Xenopus oocytes to clarify a possible involvement of rBAT in heavy metal-induced aminoaciduria. The heavy metals Hg2+ and Pb2+ inhibited rBAT-induced amino acid transport with a different profile of action. The Pb2+ mediated inhibition occurred rapidly upon superfusion and was readily reversible upon washout. The maximal inhibition caused by Pb2+ was about 50% of the amino acid-induced currents at an apparent affinity (Km) of about 10 microM. In contrast, the Hg(2+)-mediated inhibition occurred rather slowly, depending on its concentration, and was not reversible during washout with control solution. However, the Hg(2+)-mediated amino acid transport inhibition could be reversed with Hg2+ chelating agents and reducing compounds. Other oxidative agents, such as the membrane permeable 2,2'-Dithio-bis(5-Nitropyridine) (DTNP), but not the membrane impermeable 5,5'-Dithio-bis (2-Nitrobenzoic acid) (DTNB), mimicked the effect of Hg2+, and their effect could similarly be reversed with 2,3-Dihydroxybutane-1,4-dithiol (DTE). In conclusion, Pb2+ and Hg2+ inhibit rBAT-induced amino acid transport in a noncompetitive, allosteric fashion. Blockade of rBAT-induced amino acid transport may be involved in aminoaciduria following mercury or lead intoxication.

Amino Acid Transport Systems, Basic↗
PubMed2001

The molecular bases of cystinuria and lysinuric protein intolerance.

Cystinuria and lysinuric protein intolerance are inherited aminoacidurias caused by defective amino-acid transport activities linked to a family of heteromeric amino-acid transporters (HATs). HATs comprise two subunits: co-expression of subunits 4F2hc and y(+)LAT-1 induces the efflux of dibasic amino acids from cells, whereas co-expression of subunits rBAT and b(o,+)AT induces the renal reabsorption and intestinal absorption of cystine and dibasic amino acids at the brush border of epithelial cells. Recently, the role of b(o,+)AT (SLC7A9) in cystinuria (non Type I) and the role of y(+)LAT-1 (SLC7A7) in lysinuric protein intolerance have been demonstrated.

Amino Acid Sequence↗
PubMed1990

Nephrotoxicity after ifosfamide.

Eleven children and adolescents with previously normal renal function who received ifosfamide for the treatment of extrarenal solid tumours underwent detailed investigation of glomerular and renal tubular function to assess the incidence and extent of renal damage. None had received cisplatin. Glomerular filtration rate (measured by plasma clearance of 51Cr labelled edetic acid) was reduced in six children. All 11 patients had evidence of proximal, and six of distal, tubular damage. Proximal tubular toxicity was indicated by phosphaturia and hypophosphataemia (n = 4), glycosuria (n = 5), increased urine beta 2 microglobulin excretion (n = 11), and generalised aminoaciduria (n = 10); distal tubular damage caused a reduction of the osmolality of the urine in an early morning sample. Two children developed clinical hypophosphataemic rickets, and one of these also had severe nephrogenic diabetes insipidus. Glomerular and tubular nephrotoxicity are common and potentially serious complications of ifosfamide treatment in children.

Adolescent↗