1/16. Familial hypouricaemia due to renal tubular defect of urate transport.A 28-year-old man was found to have hypouricaemia (plasma uric acid, 0.40 to 1.25 mg/100 ml). The 24-hour urinary urate excretion on a low purine diet was 690 mg, a value higher than the mean value of 419 mg for gouty Japanese patients. Urate clearance was 88.5 ml/min--approximately the same as the endogeneous creatinine clearance. The ratio of urate clearance to creatinine clearance was scarcely altered by pyrazinamide, but diminished by probenecid (from 69.2% to 52.4%). No other renal tubular abnormalities were detected. The findings in this subject may be accounted for by a nearly complete tubular defect in reabsorptive transport mechanisms of urate. A survey of his family revealed at least three similarly affected persons, who were all from consanguineous marriages. The hypouricaemia was transmitted as an autosomal trait.- - - - - - - - - - ranking = 1keywords = urinary (Clic here for more details about this article) |
2/16. Hypouricemia due to familial isolated renal tubular uricosuria. Evaluation with the combined pyrazinamide-probenecid test.A Jewish Iraqi woman with familial isolated renal tubular uricosuria, urate clearance of 60.5 /- 5.7 ml/min and hypouricemia of 1.0 /- 0.2 mg/dl is described. The combined pyrazinamide-probenecid test suggested a presecretory defect in urate reabsorption. Four offspring were moderately affected. This family represents the sixth Jewish Iraqi family with familial isolated presecretory uricosuria, and emphasizes the marked prevalence of this disease among the Iraqi Jewish population. Since the inheritance of the presecretory defect is autosomal recessive, we suggest that this family is an example of pseudodominant transmission. The combined pyrazinamide-probenecid test may cause a reduction in glomerular filtration rate and filtered load of urate and thereby affect urinary excretion rate of urate in patients with urate wasting.- - - - - - - - - - ranking = 1keywords = urinary (Clic here for more details about this article) |
3/16. Familial pseudohypoaldosteronism.The clinical course of two siblings with a severe form of pseudohypoaldosteronism was followed over a period of seven and five years respectively. Both children persistently had a high sodium-potassium excretion ratio in the urine, sweat, saliva, and stools as well as high serum concentrations of aldosterone and renin and an increased urinary excretion of tetrahydroaldosterone. Despite sustained treatment with sodium chloride (10-40 mmol/kg/d) and cation exchange resin (sodium polystyrole sulfonate 0.5-2 g/kg/d) they repeatedly developed episodes of salt wasting and hyperkalemia which occurred mainly during uncomplicated respiratory tract infections. aldosterone receptor characteristics were studied in the cytosol of the rectal mucosa at ages 2.5 years and 6 months respectively. Compared to age matched controls there was a decreased affinity for aldosterone at the low affinity binding site. Among the members of the family, the father and one of his sisters had high concentrations of sodium in the sweat and an increased urinary excretion of tetrahydroaldosterone.- - - - - - - - - - ranking = 2keywords = urinary (Clic here for more details about this article) |
4/16. Successful indomethacin treatment of two paediatric patients with severe tubulopathies. A boy with an unusual hypercalciuria and a girl with cystinosis.Two children were followed for severe congenital tubulopathies: a boy presented an excessive sodium, calcium and water excretion; a girl had cystinosis and a De Toni-Debre-fanconi syndrome. These renal defects were both associated with increased levels of plasma renin activity and aldosterone, and excessive urinary PGE1 production. They had been unresponsive to therapeutic attempts. Only indomethacin treatment was successful in reversing the biochemical abnormalities and improving the growth pattern.- - - - - - - - - - ranking = 1keywords = urinary (Clic here for more details about this article) |
5/16. Ultrastructural, neurological, and glycosaminoglycan abnormalities in lowe's syndrome.The oculocerebrorenal syndrome (OCRS), Lowe's syndrome, is an X-linked, recessive disease characterized by mental retardation, congenital corneal abnormalities and cataracts, growth failure, rickets, osseous abnormalities, renal dysfunction with periodic acidosis, hypotonia, and areflexia. Ultrastructural studies of skin biopsy specimens in three individuals with the disorder (aged 17, 9, and 8 years) revealed cytoplasmic, membrane-bound, electron-lucent vacuoles and some electron-dense membranous inclusion bodies in fibroblasts and schwann cells, as well as axonal degeneration and vascular changes. Computed tomographic scans evidenced brain atrophy. Urinary excretion of glycosaminoglycans (GAG) was four to five times greater than in normal controls. The predominant urinary GAG was a low-sulfated chondroitin-4-sulfate; chondroitin-6-sulfate and heparan sulfate excretion levels were normal. A tenfold increase in urinary GAG excretion was found in one patient with oculocerebrorenal syndrome during periods of behavioral agitation. These findings suggest that the clinical stigmata of oculocerebrorenal syndrome may be related to a defect in GAG metabolism.- - - - - - - - - - ranking = 2keywords = urinary (Clic here for more details about this article) |
6/16. pseudohypoaldosteronism. Clinical, biochemical and morphological studies in a long-term follow-up.A boy with pseudohypoaldosteronism was followed from birth to the age of 7 years. failure to thrive, vomiting, dehydration, hyponatraemia and urinary sodium loss were prominent findings. Urinary excretion of corticosteroid metabolites was normal. Before treatment, excessively high plasma renin concentration was found, associated with a marked activation of aldosterone secretion. A renal biopsy showed pronounced hypertrophy of the juxtaglomerular apparatus. Persisting metabolic acidosis and an insufficient urinary acidifying capacity suggested the presence of distal renal tubular acidosis. Treatment with sodium bicarbonate and sodium chloride from 19 to 31 months of age resulted in normal growth and normal physical and mental development. The plasma electrolytes were normalized but a pronounced activation of the renin-aldosterone system persisted after therapy, and on sodium restriction this system responded with a considerable further activation.- - - - - - - - - - ranking = 2keywords = urinary (Clic here for more details about this article) |
7/16. The effect of triamterene and sodium intake on renin, aldosterone, and erythrocyte sodium transport in Liddle's syndrome.Liddle's syndrome was diagnosed in a 23-yr-old Chinese girl with hypertension and hypokalemia by the presence of suppressed renin and negligible plasma and urinary aldosterone secretion. Adrenal corticosteroids, including aldosterone, were suppressed by dexamethasone and stimulated by ACTH. While spironolactone was ineffective, triamterene (2,4,7-triamino-6-phenyl-pteridine) treatment corrected the hypertension and hypokalemia and restored PRA to normal provided that sodium intake was not excessive. During long term treatment with triamterene, blood pressure was extremely sensitive to salt intake, increasing promptly with high intake and decreasing with low salt intake. As a result of the chronic hypervolemia and sodium retention consequent upon the patient's persistent high salt intake and increased renal tubular sodium reabsorption, plasma renin and aldosterone remained low. Erythrocyte sodium concentration and membrane permeability were increased. triamterene with salt restriction was able to lower the intracellular sodium concentration but did not correct the increased sodium permeability. This suggests that there is an abnormality of sodium transport in Liddle's syndrome which affects the erythrocytes as well as the renal tubular cells.- - - - - - - - - - ranking = 1keywords = urinary (Clic here for more details about this article) |
8/16. Coincidence of pseudohypoaldosteronism with gluten-enteropathy.This is a 21-month-old boy with pseudohypoaldosteronism (PHA) in coincidence with celiac disease. The diagnosis of PHA was made on the basis of hyponatremia, hyperkalemia and large urinary salt losses, as well as high renin activity and aldosterone levels and increased urinary plasma aldosterone. Whereas mineralocorticoid therapy was ineffective, salt therapy has proven successful. The patient's HLA type was found to be characteristic of gluten-enteropathy (A1, B8, DR3). The combination of PHA and celiac disease has not yet been described and is probably a coincidence. However, it is suggested that other PHA patients be typed in order to investigate the segregation between HLA type, PHA and celiac disease.- - - - - - - - - - ranking = 2keywords = urinary (Clic here for more details about this article) |
9/16. Low urinary excretion of heparan sulfate in three patients with Lowe's syndrome.Urinary glycosaminoglycans were isolated with the cetylpyridinium chloride (CPC) precipitation method and the excretion of individual species of urinary glycosaminoglycans in three patients with Lowe's syndrome was compared with that of age-matched control children by means of electrophoresis on cellulose acetate membranes and by quantification of hexosamine contents. Total daily excretion of urinary glycosaminoglycans in the patients seemed to be normal, but the relative excretion of urinary heparan sulfate was significantly reduced and ranged from 26 to 46% of the age-matched control mean, when calculated on the basis of relative glucosamine content in urinary glycosaminoglycans. Although electrophoretograms of urines from patients with Lowe's syndrome suggested some excess of low sulfated chondroitin sulfate corresponding in mobility to dermatan sulfate, the enzymatic subunit assay employing chondroitinases did not disclose any significant differences in the excretion pattern or in the degree of sulfation of chondroitin sulfate isomers between lowe's syndrome and control children.- - - - - - - - - - ranking = 8keywords = urinary (Clic here for more details about this article) |
10/16. Tumoral calcinosis: evidence for concurrent defects in renal tubular phosphorus transport and in 1 alpha,25-dihydroxycholecalciferol synthesis.A 50-year-old Latin American man with tumoral calcinosis presented with hyperphosphatemia (6.62 /- 1.04 SD mg/dl), elevated renal threshold phosphorus concentration (TmP) (7.3 mg/GFR), and 1,25-dihydroxyvitamin D [1,25-(OH)2D] (69 pg/ml) hypercalciuria (239 mg/day), and a high fractional intestinal calcium (Ca) absorption (0.74). Sodium cellulose phosphate therapy (20 g/day) lowered urinary Ca, and partially reduced serum phosphorus (P) and TmP to 5.91 /- 0.63 mg/dl and 6.2 mg/GFR, respectively. serum 1,25-(OH)2D remained elevated at 58-64 pg/ml. Amphojel therapy (4 oz/day) decreased urinary P to 23 /- 21 mg/day and lowered serum P to 5.75 /- 0.36 mg/dl (P < 0.05). TmP increased to a value of 8.0 mg/GFR while serum 1,25-(OH)2D continued to remain elevated at 53 pg/ml. This case illustrates the probable operation of dual abnormalities in tumoral calcinosis represented by augmented renal conservation of P and an elevation in the circulating concentration of 1,25-(OH)2D.- - - - - - - - - - ranking = 2keywords = urinary (Clic here for more details about this article) |
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