Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020500 (hyperoxaluria)
 912 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Plasma pyridoxine metabolites in plasma and 4-pyridoxic acid excretions in urine were measured in normal subjects, in 7 patients with type-1 hyperoxaluria and in 8 patients with mild metabolic hyperoxaluria, while receiving various doses of pyridoxine. Compliance with ingestion of pyridoxine was verified by measuring urinary 4-pyridoxic acid. In the normal subjects the maximum level of pyridoxal phosphate was obtained after only 10 mg/day of pyridoxine. The patients were divided into nonresponders, good responders and poor responders to pyridoxine according to the fall in urinary oxalate and glycollate excretions. In patients taking pyridoxine, the plasma pyridoxal phosphate levels were as for normal subjects in primary hyperoxaluria, lower than for normal subjects in mild metabolic hyperoxaluria (p less than 0.01), and in the latter group lower in partial responders than in good responders (p = 0.04). Hence in mild metabolic hyperoxaluria there may be difficulty in converting pyridoxine to pyridoxal phosphate.
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PMID:Metabolism of pyridoxine in mild metabolic hyperoxaluria and primary hyperoxaluria (type 1). 177 98

Primary hyperoxaluria type I (PH I) is characterized by an excessive endogenous production and excretion of oxalic and glycolic acid. Prognosis of this "inborn error of metabolism" is not favorable due to calcium-oxalate depositions in kidney and other organs. Vitamin B6 administration and/or renal transplantation can greatly improve the prognosis, as reported in literature. In this article our experience with 5 patients with vitamin B6 resistant hyperoxaluria is reported. Symptomatology and progression of the primary disease are described. The results of treatment interfering with oxalate production and calcium-oxalate crystallization are given. Three patients underwent renal replacement therapy. In these, oxalosis developed during hemodialysis and progressed following transplantation; a disabling bone disease was the most severe complication. Outcome of transplantation was disappointing. In two out of three patients, there was recurrence of the primary disease in the graft. In only one of them long-term graft function was satisfying. However, even this good function could not prevent disabling symptoms of oxalosis. Therefore, evaluation of the results of transplantation should not only include data related to graft function and survival, but also the complications due to calcium-oxalate depositions in various organs. To prevent oxalosis, kidney transplantation should be performed before end stage renal disease is achieved in patients with vitamin B6 resistant PH I.
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PMID:Vitamin B6 resistant primary hyperoxaluria type I. Report of 5 cases. 270 72

An 8-year-old boy who had suffered from recurrent stone formation since the age of 4 years, was admitted as an emergency due to anuria for a half day on November 20, 1986. Kidney-ureter-bladder film showed that the urethra was obstructed by a stone, and emergent cystoscopy was performed to remove it. He is the product of consanguinous marriage, his parents being first cousins. There was no family history of renal stone. Laboratory investigations showed hypokalemic, hyperchloremic metabolic acidosis. The ammonium chloride loading test revealed inability to acidify the urine and a markedly decreased excretion of titrable hydrogen ion and ammonium ion in the urine. These results indicate that this is a case of Type I renal tubular acidosis. His 24-hour urinary excretion of oxalate and glyoxylate were also markedly increased. There were no underlying causes leading to the development of secondary hyperoxaluria. These results also establish the diagnosis of Type I primary hyperoxaluria. The patient then received regimens of Polycitra 1ml/kg/day and Vitamin B6 50mg/day for 4 months. However, urinary stone developed again in this patient 4 months later. To our knowledge, Type I primary hyperoxaluria in association with Type I renal tubular acidosis has not been previously reported.
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PMID:Type I primary hyperoxaluria associated with type I renal tubular acidosis. 344 74

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

The prevalence of nephrolithiasis (12% of the population) is directly related to environmental risk factors including nutrition. Correlations have been demonstrated between activity of renal stone disease and excessive protein intake or low fiber diets, and cause-and-effect relationships have been suggested between prevalence of the disease and low urine volume due to underhydration. Indeed eating too much meat and drinking too little can expose certain subjects, but not all, to nephrolithiasis. Why? Populations at risk include subjects with medullary sponge kidneys who represent 10% of the patients with idiopathic calcium nephrolithiasis and those with mild metabolic hyperoxaluria who cannot activate pyridoxin to 5' pyridoxal phosphate. Defective intestinal absorption of citrate and modifications in protein structures which inhibit urinary crystallization have also been observed. Clearly, many apparently normal subjects are overly susceptible to nephrolithiasis and the "explosion" would appear to be programmed if they are exposed to additional risk factors. Thus our theory of the powder keg and the tinderbox.
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PMID:[Pathogenesis of renal calculi]. 797 43

Vitamin B6 metabolites and their potential correlates to urinary oxalate excretion in idiopathic calcium stone formers (ICSF) compared with healthy subjects were investigated. This clinical study was performed in a population of male ICSF with (Hyperoxalurics, n=55) or without hyperoxaluria (Normooxalurics, n=57) as well as in 100 healthy male control subjects. Pyridoxal 5'-phosphate serum concentration (S-pyridoxal 5'P) and 24-h urinary excretion of 4-pyridoxic acid (U-4pyridoxic acid) were measured using HPLC; 24-h urinary excretion of oxalate (U-oxalate) was measured concurrently. A subgroup of subjects (40 Hyperoxalurics, 15 Normooxalurics and 50 controls) underwent the same measurements before and after 7-day pyridoxine loading per os (pyridoxine hydrochloride, 300 mg/d). Under usual conditions, U-4pyridoxic acid was similar in the three groups, whereas mean S-pyridoxal 5'P was significantly lower ( p<0.0001) in the Hyperoxalurics (59.6+/-21.2 nmol/L) and in the Normooxalurics (64.9+/-19.7 nmol/L) than in the controls (86.0+/-31.0 nmol/L). No correlation could be found between U-oxalate and U-4pyridoxic acid or S-pyridoxal 5'P. After B6 loading, S-pyridoxal 5'P was still significantly lower in the Hyperoxalurics (415+/-180 nmol/L, p<0.001) and in the Normooxalurics (429+/-115 nmol/L, p=0.036) than in the controls (546+/-180 nmol/L), although there was no difference between groups for U-4pyridoxic acid. No correlation in any group could be found between changes in U-oxalate and changes in U-4pyridoxic acid or S-pyridoxal 5'P. Although there is no vitamin B6 deficiency in ICSF with or without hyperoxaluria, these patients, on average, have lower levels of S-pyridoxal 5'P than healthy subjects. However, this slight decrease does not seem to account for idiopathic hyperoxaluria.
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PMID:Vitamin B6 metabolites in idiopathic calcium stone formers: no evidence for a link to hyperoxaluria. 1462 6