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Query: UMLS:C0020500 (hyperoxaluria)
 912 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of some putative inhibitors of oxalate production or urinary oxalate excretion have been investigated in the Cynamolgus monkey and in patients with Type I primary hyperoxaluria (hyperoxaluria with glycollic aciduria). Sodium-1-hydroxybutan-sulphonate, D,L-phenyllactate, succinimide and isocarboxazide did not reduce the urinary oxalate excretion in the monkeys. Pyridoxine reduced the excretion of oxalate and glycollate in some patients, and its therapeutic use has been documented over a five-year period. Succinimide, which has been used by other workers for the treatment of non-hyperoxaluric stone formers, did not decrease the excretion of either oxalate or glycollate in three patients in whom it was tried. It did not change the inhibitory activity of the urine with respect to the growth and aggregation of calcium oxalate crystals in any of the three patients, and it did not have any consistent effect on the excretion of calcium oxalate crystals in the one patient who had detectable crystaluria before treatment. We have identified several metabolites of succinimide in the urine of patients taking the drug. These include 2,3-dehydrosuccinamic, 2-hydroxysuccinamic and 3-hydroxysuccinamic acids. Isocarboxazide, cholestyramine and thiamine did not affect the urinary oxalate excretion in the patients. The significance of these observations from the viewpoint of the treatment of primary hyperoxaluria is discussed.
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PMID:Studies on some possible biochemical treatments of primary hyperoxaluria. 11 1

To differentiate hyperoxaluria syndromes we measured plasma and urine glycolate by a novel high performance liquid chromatographic procedure. Mean glycolate level was 7.9 +/- 2.4 mumol./l. in plasma and 422 +/- 137 mumol./24 hours in urine from 19 control subjects. Renal clearance was about 50% the glomerular filtration rate irrespective of the underlying disease. There was close correlation between glycolate and oxalate in plasma. Plasma glycolate was normal in all but 8 patients who had primary hyperoxaluria 1. Plasma assay detected the disease more efficiently than urine assay. Pyridoxine decreased oxalate biosynthesis in 2 of the 4 patients treated with it and glycolate assay confirmed this behavior. Glycolate excretion was significantly high in 3 of 8 patients of primary hyperoxaluria 1 patients. Idiopathic stone formers had mild increases in glycolate excretion but this was not related with oxalate excretion. Glycolate levels were normal in 5 patients with enteric hyperoxaluria. We conclude that glycolate assay is essential for identifying patients with primary hyperoxaluria 1 and may represent a valuable tool for differentiating hyperoxaluria.
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PMID:Plasma and urine glycolate assays for differentiating the hyperoxaluria syndromes. 150 56

Pyridoxine in doses of 250-500 mg daily by mouth was administered to 12 patients suffering from recurrent calcium oxalate renal calculi and idiopathic hyperoxaluria. This therapy decreased urinary oxalate excretion significantly (p less than 0.025) during up to 18 months of treatment. In that period eight patients showed no evidence of active stone disease; three showed slight increase in the size of their old stone(s) and one patient formed one new stone. None of these patients developed any significant complications of the therapy. These findings support the view that pyridoxine in pharmacological doses is useful in the control of elevated urinary oxalate excretion in patients with recurrent renal oxalate calculi.
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PMID:Control of hyperoxaluria with large doses of pyridoxine in patients with kidney stones. 317 Jan 5

The urinary excretion levels of oxalic acid, calcium, kynurenic, and xanthurenic acids and serum pyridoxal and pyridoxal phosphate concentrations were determined for nonbilharzial and bilharzial hyperoxaluric patients with or without urinary stones. The effects of pyridoxine and allopurinol treatment were also studied. The different groups studied showed elevated levels of urinary oxalic acid, calcium, kynurenic, and xanthurenic acids as well as decreases in serum pyridoxal and pyridoxal phosphate concentrations. These data indicate that nonbilharzial hyperoxaluric patients suffer from dietary B6 deficiency, whereas bilharzial hyperoxaluric patients may suffer from impaired pyridoxine phosphokinase activity. Pyridoxine supplementation is recommended for the treatment of nonbilharzial hyperoxaluric patients. Allopurinol may be the proper drug in the treatment of oxaluria and stone formation or of bilharzial patients.
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PMID:Biochemical studies on bilharzial and nonbilharzial hyperoxaluria: effect of pyridoxine and allopurinol treatment. 366 92

Pyridoxine (vitamin B6), given to patients with primary hyperoxaluria of type I, generally leads to a decrease in urinary excretion of oxalate owing to stimulation of conversion of glyoxylate to glycine instead of oxalate. It is not known, however, whether pyridoxine would equally influence hyperoxalurias of other origins, e.g. idiopathic or enteric. Two groups of patients were therefore given pyridoxine orally for 2 months (300 mg/d). Group 1 consisted of 10 idiopathic stone formers with mild hyperoxaluria of unknown origin. Group 2 consisted of 4 patients with enteric hyperoxaluria after intestinal bypass surgery. As a mean, enteric hyperoxaluria was not influenced by vitamin B6, which suggests that this disorder is the consequence of intestinal hyperabsorption of oxalate rather than of glyoxylate. In contrast, idiopathic hyperoxaluria was influenced by vitamin B6: urinary excretion of oxalate decreased in 8 patients out of 10 and became normal in 7. However, two patients did not respond to pyridoxine; both had concomitant severe hyperuricosuria (greater than 1 g/24 h), an observation suggesting that in these cases hyperoxaluria was of dietary origin. Four of the patients whose urinary excretion of oxalate became normal while on pyridoxine were followed up for 8 to 36 months after treatment: in all of them oxaluria remained normal. One whose oxaluria had returned to the upper normal limit was retreated after 2 years and again displayed a fall in urinary oxalate. It is concluded that pyridoxine given to idiopathic hyperoxalurics may correct the disorder, as in primary hyperoxaluria of type I; this is not the case in enteric hyperoxaluria. The mechanisms governing this sensitivity to vitamin B6 remain to be clarified.
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PMID:[Pyridoxine can normalize oxaluria in idiopathic renal lithiasis]. 379 70

Twelve recurrent stone formers with hyperoxaluria were administered pyridoxine-HCl (10 mg/day) daily for a period of 180 days. The pyridoxine status of the patients, as assessed by their erythrocyte transaminase activation indexes, improved significantly (p less than 0.001) after 180 days of supplementation as compared with the basal levels. Although urinary oxalate decreased significantly (p less than 0.05) by the 90th day of pyridoxine therapy, other parameters, e.g., urinary calcium, phosphorus, and creatinine, remained unaltered. Significant correlation was observed between erythrocyte glutamate pyruvate transaminase (EGPT) or erythrocyte glutamate oxaloacetate transaminase (EGOT) activation index and urinary oxalate excretion (p less than 0.01). Pyridoxine in low doses (10 mg/day) is of therapeutic value for hyperoxaluric stone formers.
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PMID:Effect of pyridoxine supplementation on recurrent stone formers. 714 62

In order to prevent kidney stones and nephrolithiasis in hyperoxaluria, a new treatment that specifically reduces oxalate production and therefore urinary oxalate excretion would be extremely valuable. Pyridoxamine(PM) could react with the carbonyl intermediates of oxalate biosynthesis, glycolaldehyde and glyoxylate, and prevent their metabolism to oxalate. In PM treated rats, endogenous urinary oxalate levels were consistently lower and became statistically different from controls after 12 days of experiment. In ethylene glycol-induced hyperoxaluria, PM treatment resulted in significantly lower (by ~50%) levels of urinary glycolate and oxalate excretion compared to untreated hyperoxaluric animals, as well as in a significant reduction in calcium oxalate crystal formation in papillary and medullary areas of the kidney. These results, coupled with favorable toxicity profiles of PM in humans, show promise for the therapeutic use of PM in primary hyperoxaluria and other kidney stone diseases.
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PMID:Pyridoxamine lowers oxalate excretion and kidney crystals in experimental hyperoxaluria: a potential therapy for primary hyperoxaluria. 1629 84

The Zellweger spectrum disorders (ZSDs) are characterized by a generalized loss of peroxisomal functions caused by deficient peroxisomal assembly. Clinical presentation and survival are heterogeneous. Although most peroxisomal enzymes are unstable in the cytosol of peroxisome-deficient cells of ZSD patients, a few enzymes remain stable among which alanine:glyoxylate aminotransferase (AGT). Its deficiency causes primary hyperoxaluria type 1 (PH1, MIM 259900), an inborn error of glyoxylate metabolism characterized by hyperoxaluria, nephrocalcinosis, and renal insufficiency. Despite the normal level of AGT activity in ZSD patients, hyperoxaluria has been reported in several ZSD patients. We observed the unexpected occurrence of renal stones in a cohort of ZSD patients. This led us to perform a study in this cohort to determine the prevalence of hyperoxaluria in ZSDs and to find clinically relevant clues that correlate with the urinary oxalate load. We reviewed medical charts of 31 Dutch ZSD patients with prolonged survival (>1 year). Urinary oxalate excretion was assessed in 23 and glycolate in 22 patients. Hyperoxaluria was present in 19 (83%), and hyperglycolic aciduria in 14 (64%). Pyridoxine treatment in six patients did not reduce the oxalate excretion as in some PH1 patients. Renal involvement with urolithiasis and nephrocalcinosis was present in five of which one developed end-stage renal disease. The presence of hyperoxaluria, potentially leading to severe renal involvement, was statistically significant correlated with the severity of neurological dysfunction. ZSD patients should be screened by urinalysis for hyperoxaluria and renal ultrasound for nephrocalcinosis in order to take timely measures to prevent renal insufficiency.
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PMID:High incidence of hyperoxaluria in generalized peroxisomal disorders. 1662 44

To determine the clinical, biological, and radiological futures of primary hyper-oxaluria type 1 in Tunisian children, we retrospectively studied 44 children with primary hyper-oxaluria type 1 who were treated in our center from 1995 to 2009. The diagnosis was established by quantitative urinary oxalate excretion. In patients with renal impairment, the diagnosis was made by infrared spectroscopy of stones or kidney biopsies. The male-to-female ratio was 1:2. The median age at diagnosis was 5.75 years. About 43% of the patients were diagnosed before the age of five years with initial symptoms dominated by uremia. Four patients were asymptomatic and diagnosed by sibling screenings of known patients. Nephrocalcinosis was present in all the patients; it was cortical in 34%, medullary in 32%, and global in 34%. At diagnosis, 12 (27%) children were in end-stage renal disease. Pyridoxine response, which is defined by a reduction in urine oxalate excretion of 60% or more, was obtained in 27% of the cases. In the majority of patients, the clinical expression of primary hyperoxaluria type 1 was characterized by nephrocalcinosis, urolithiasis, and renal failure; pyridoxine sensitivity was associated with better outcome.
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PMID:Primary hyperoxaluria type 1 in Tunisian children. 2238 46

Hyperoxaluria is characterized by an increased urinary excretion of oxalate. Primary and secondary hyperoxaluria are two distinct clinical expressions of hyperoxaluria. Primary hyperoxaluria is an inherited error of metabolism due to defective enzyme activity. In contrast, secondary hyperoxaluria is caused by increased dietary ingestion of oxalate, precursors of oxalate or alteration in intestinal microflora. The disease spectrum extends from recurrent kidney stones, nephrocalcinosis and urinary tract infections to chronic kidney disease and end stage renal disease. When calcium oxalate burden exceeds the renal excretory ability, calcium oxalate starts to deposit in various organ systems in a process called systemic oxalosis. Increased urinary oxalate levels help to make the diagnosis while plasma oxalate levels are likely to be more accurate when patients develop chronic kidney disease. Definitive diagnosis of primary hyperoxaluria is achieved by genetic studies and if genetic studies prove inconclusive, liver biopsy is undertaken to establish diagnosis. Diagnostic clues pointing towards secondary hyperoxaluria are a supportive dietary history and tests to detect increased intestinal absorption of oxalate. Conservative treatment for both types of hyperoxaluria includes vigorous hydration and crystallization inhibitors to decrease calcium oxalate precipitation. Pyridoxine is also found to be helpful in approximately 30% patients with primary hyperoxaluria type 1. Liver-kidney and isolated kidney transplantation are the treatment of choice in primary hyperoxaluria type 1 and type 2 respectively. Data is scarce on role of transplantation in primary hyperoxaluria type 3 where there are no reports of end stage renal disease so far. There are ongoing investigations into newer modalities of diagnosis and treatment of hyperoxaluria. Clinical differentiation between primary and secondary hyperoxaluria and further between the types of primary hyperoxaluria is very important because of implications in treatment and diagnosis. Hyperoxaluria continues to be a challenging disease and a high index of clinical suspicion is often the first step on the path to accurate diagnosis and management.
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PMID:Primary and secondary hyperoxaluria: Understanding the enigma. 2594 37


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