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

The following main conclusions concerning the transplantation strategies to be adopted in primary hyperoxaluria type 1 (PH1) were drawn from the data collected from 22 patients who received combined liver-kidney grafts and 2 patients who received isolated liver grafts in Europe from June 1984 to March 1990. In end-stage renal failure due to PH1 liver-kidney transplantation yields better results than conventional renal transplantation. An isolated liver graft should be planned in patients with GFR between 25 and 60 ml/min/1.73 m2 whereas a combined liver-kidney graft is to be recommended as soon as the GFR falls below 25 ml/min/1.73 m2. Such patients should not be maintained on dialysis for more than a few months since they would unavoidably develop oxalosis with the risk of disabling lesions in the skeleton and cardiovascular system. Besides, oxalosis would be regularly followed by long-standing hyperoxaluria, with the risk of damage to the kidney graft, despite the correction of the enzyme deficit brought up by the liver graft.
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PMID:[Which transplantation strategies in primary hyperoxaluria type 1?]. 192 55

In approximately one-third of primary hyperoxaluria type 1 patients, disease is associated with a unique protein sorting defect in which hepatic L-alanine:glyoxylate aminotransferase (AGT; EC 2.6.1.44), which is normally peroxisomal, is mistargeted to mitochondria. In all such patients analyzed to date, the gene encoding the aberrantly targeted AGT carries three point mutations, each of which specifies an amino acid substitution. In this paper we show that one of these substitutions, a proline-to-leucine at residue 11, is necessary and sufficient for the generation of a mitochondrial targeting sequence in the AGT protein. AGT with this substitution appears to interact specifically with the mitochondrial protein import machinery, via a discrete N-terminal domain of the AGT protein. The N-terminal 19 amino acids of AGT with this substitution are sufficient to direct mouse cytosolic dihydrofolate reductase to mitochondria, and a synthetic peptide corresponding to this same 19-amino acid region reversibly inhibits mitochondrial protein import, not only of AGT but also of ornithine transcarbamoylase, a genuine cytoplasmically synthesized mitochondrial protein. We have extended these studies to analyze a region of normal human AGT cDNA directly upstream of the coding region. This sequence appears to correspond to an ancestral mitochondrial targeting sequence deleted from the human coding region by point mutation at the initiation codon. We show that reestablishment of this initiation codon produces an active mitochondrial targeting sequence that is different to that found in the hyperoxaluria patients. These results are discussed with reference to the AGT targeting defect in primary hyperoxaluria and also in relation to the highly unusual species specificity of subcellular distribution of AGT among mammals.
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PMID:Mistargeting of peroxisomal L-alanine:glyoxylate aminotransferase to mitochondria in primary hyperoxaluria patients depends upon activation of a cryptic mitochondrial targeting sequence by a point mutation. 196 59

The detection of type I primary hyperoxaluria is based on the finding of exceedingly high oxalate excretion which is associated with increased glycolate excretion. The differential diagnosis of this disease may become a difficult task once end-stage renal disease (ESRD) and anuria have supervened. The various procedures thus far proposed to obviate this circumstance are complex, inaccurate or not reproducible. In this paper we propose the accurate liquid chromatographic determination of glycolate in blood and dialysate as a means to detect type I primary hyperoxaluria in patients on maintenance hemodialysis (RDT). The method is based on the enzymatic conversion of glycolate to glyoxylate coupled with alpha-keto acid derivatization with phenylhydrazine. The resulting phenylhydrazone is then resolved by high-performance liquid chromatograph (HPLC). With this method, plasma glycolate in 12 healthy controls was 7.8 +/- 1.7 mumol/liter, almost twentyfold less than previously reported. Five dialysis patients with high serum oxalate, of whom four with primary hyperoxaluria and one with Crohn's disease and presumed enteric oxalate hyperabsorption, were checked by this method and compared to nine patients with oxalosis-unrelated ESRD. The patients with hyperoxalemia were also evaluated for their response to pyridoxine therapy. The measurement of glycolate in blood drawn prior to and at the end of the dialysis session as well as in the dialysate soundly discriminated the patients with type I hyperoxaluria from all the other dialysis patients. Glycolate measurement was shown to be much more powerful than oxalate in that patients with oxalosis-induced ESRD exhibited an almost two hundred and fiftyfold increase compared to the oxalosis-unrelated patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Glycolate determination detects type I primary hyperoxaluria in dialysis patients. 200 28

Hyperoxaluria is an important risk factor in patients who form calcium oxalate stones within the urinary tract. It occurs in patients with primary hyperoxaluria, enteric hyperoxaluria, and the syndrome of idiopathic calcium oxalate urolithiasis. In the latter condition, the specific causes of the hyperoxaluria are not well defined. Diet and the availability of calcium and oxalate from the diet within the intestine are important factors in the hyperoxaluria that is present in some of these patients with idiopathic calcium oxalate urolithiasis. Other abnormalities in endogenous metabolism or transport of oxalate may play a role in the hyperoxaluria in some of these patients.
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PMID:Diet and hyperoxaluria in the syndrome of idiopathic calcium oxalate urolithiasis. 200 1

A case of primary hyperoxaluria is presented. In a product of consanguinous marriage recurrent stone formation, nephrocalcinosis and increased urinary oxalate excretion revealed the diagnosis of hyperoxaluria. Diagnosis and treatment of primary hyperoxaluria are briefly reviewed and the importance of elevated urinary oxalate level in diagnosis is emphasized.
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PMID:Early onset of stone diseases and primary hyperoxaluria. 221 Sep 75

A case of primary hyperoxaluria is presented. In a product of consanguinous marriage, recurrent stone formation, nephrocalsinosis and increased urinary oxalate excretion revealed the diagnosis of hyperoxaluria. Diagnosis and treatment of primary hyperoxaluria briefly reviewed and the importance of elevated urinary oxalate level in diagnosis is emphasized.
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PMID:Early onset of stone diseases and primary hyperoxaluria. 228 20

Severe oxalate nephropathy with end-stage kidney lesions was found in two pups of a litter of three Tibetan Spaniels. This histopathological finding strongly suggests a primary hyperoxaluria since there was no exposure to agents capable of producing secondary hyperoxaluria. Primary hyperoxaluria has not been reported as a spontaneous disease in the dog, although it is a well-known, but rare, inherited metabolic disease of man.
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PMID:Oxalate nephropathy in a Tibetan spaniel litter. A probable case of primary hyperoxaluria. 239 49

In normal adults the urinary excretion of oxalate rarely exceeds 0.5 mmol/24 hours-1 despite dietary and seasonal fluctuations of intake and absorption. Hyperoxaluria may be encountered in a number of disease states because of increased absorption of dietary oxalate or derangements of metabolism (Table 1). More unusually, hyperoxaluria may arise from one of three inborn errors of metabolism, i.e., the primary hyperoxalurias. The most common, primary hyperoxaluria type I (PHI), is recessively inherited; it will be discussed in detail in this paper. Primary hyperoxaluria type II, caused by a deficiency of D-glycerate dehydrogenase (EC 1.1.1.29), has a similar clinical pattern of disease, but has been described in only a very few families. More recently, another idiopathic form of hyperoxaluria has been defined (type III). It is likely that this form results from a primary defect in oxalate absorption in the absence of any morphologically or functionally definable intestinal disease; a satisfactory response to dietary restriction of oxalate, along with the use of thiazide diuretics, has been described.
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PMID:Perspectives in the assessment and management of patients with primary hyperoxaluria type I. 249 26

The medical history of a 42-year-old patient with primary hyperoxaluria type I is presented. Primary hyperoxaluria was suspected after renal transplantation, when oxalate deposits were found in a biopsy of the kidney graft. Diagnosis of type I hyperoxaluria was confirmed by the finding that significantly increased amounts of glycolic acid and oxalic acid were excreted. Treatment of the patient with 500 mg pyridoxine daily resulted in a decrease of the excretion of oxalate to normal values.
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PMID:Recurrence of nephrocalcinosis after renal transplantation in an adult patient with primary hyperoxaluria type I. 249 56

A patient with primary hyperoxaluria type I in infancy is reported. He had renal insufficiency, but urolithiasis was absent. Demonstration of diffuse nephrocalcinosis by renal ultrasound contributed to early diagnosis. Prolonged survival leads to extensive extrarenal oxalate deposition. Repeated skeletal surveys showed the development and the progression of severe hyperoxaluria-related bone disease. Translucent metaphyseal bands with sclerotic margins, wide areas of rarefaction at the ends of the long bones, and translucent rims around the epiphyses and the tarsal bones were signs of disordered bone growth. Bone density generally increased with time indicating progressive sclerosis due to oxalate deposition in the previously normal bone structure.
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PMID:Bone disease of primary hyperoxaluria in infancy. 268 79


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