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

Seventy-seven patients with nephrocalcinosis as revealed by X-ray studies over a 10-year period are reviewed. A programmed clinical and metabolic study was performed on each case; the author's criteria included the different pathogenic factors considered in the etiologic definition of the disease. There were 22 cases with primary hyperparathyroidism, 19 with spongy kidney, nine with tubulointerstitial nephropathy, five with hyperoxaluria, five with distal renal tubular acidosis, four with esential hypomagnesemia, and three cases of miscellaneous etiology (vitamin D intoxication, Fanconi's syndrome, Bartter's disease). Ten other cases were classified as idiopathic nephrocalcinosis since no definite cause could be found. The clinical characteristics (symptoms, associated diseases, diet and medication intake, family history) and the biochemical findings are analysed for each group. The physiopathologic mechanisms, comparisons between each etiologic group, treatment, clinical course, and prognosis are commented on. The conclusion drawn is that nephrocalcinosis is a clinical syndrome of various etiologies which in most cases arises from an underlying metabolic disease.
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PMID:[Nephrocalcinosis as a clinical syndrome. Study of 77 cases (author's transl)]. 52 25

During the past several years there has been increasing interest in refunctionalizing patients who have undergone radical extirpative surgery for pelvic malignancies and patients with dysfunctional bladders. To accomplish this, intestinal segments have been successfully employed in a variety of configurations. Independent of their optimal urosurgical implementation these procedures are not without potential complications, a significant portion of which involve metabolic derangements. Besides first follow-up results of patients with bladder substitution or continent urinary diversion, analysis of experimental investigations and functionally comparable clinical conditions enables an insight into potential following physiopathological interrelationships. These concern, besides the problem of chronic metabolic acidosis, disorders of bile acid and vitamin B12 metabolism as well as the potential induction of a secondary hyperoxaluria with subsequent oxalate concrement diathesis. Furthermore, there may be a malabsorption of calcium and vitamin D with development of intestinal osteopathy due to the reduction of absorptive surface. Apart from these problems of enteral loss and deficiency manifestations, several case reports and investigations suggest that bone demineralization can occur as a consequence of chronic metabolic acidosis and patients are at risk of skeletal demineralization. The pathogenesis of this association has yet to be clarified. These physiopathological interrelationships must be considered in medical attendance of patients with intestinal substitute bladders and continent supravesical pouch systems over many years. As these procedures become more popular, it becomes important to identify any metabolic changes that may occur as their consequence.
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PMID:[Bladder replacement and continent diversion: what about metabolic complications?]. 184 45

Farnolith (a dietary fibre preparation) was given to normal patients (n = 6) with absorptive hypercalciuria type I (n = 6) and to one patient with renal hypercalciuria. Farnolith binds calcium and reduces calcium absorption in the intestines. In normal subjects, the urine and serum parameters of calcium metabolism (total and ionized calcium, 1.25-dihydroxy-vitamin D) were unchanged. In absorptive hypercalciuria type I, a significant decrease in calcium excretion was achieved; oxalate excretion decreased as well. Low PTH values normalized; vitamin-D metabolites were not affected. In renal hypercalciuria, PTH and 1.25 DHCC were increased, whereas hypercalciuria persisted. Our investigations show that Farnolith is a reasonable treatment for absorptive hypercalciuria. Calcium homeostasis is rendered normal by Farnolith without producing secondary hyperoxaluria as sodium cellulose phosphate. Patients with primary renal calcium leakage and secondary hyperparathyroidism should not be treated with Farnolith.
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PMID:[Studies of calcium metabolism in normal persons and patients with hypercalciuria in relation to therapy with the dietary fiber preparation Farnolith]. 253 20

The formation of a neobladder by the transformation of sections of the terminal ileum has become an important alternative to supravesical urinary diversion. The discussion about the optimal urosurgical technique however has, so far ignored the problems of consecutive enteric defunctionalization and deficiency symptoms resulting from the anatomical shortening of the ileum. The analysis of experimental investigations and functionally comparable syndromes, such as Crohn's disease, permits an insight into the pathophysiological consequences. These relate to disorders in the bile acid and vitamin B12 metabolism and to the potential induction of a secondary hyperoxaluria, with a subsequent oxalate calculus diathesis. Further more, the reduction of the absorption area in the ileum can lead to calcium and vitamin D malabsorption with the development of intestinal osteopathy. These pathophysiological relationships must be taken into account in the long-term medical care of patients with ileal neobladder. The preventive and therapeutic measures are described.
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PMID:[Ileocystoplasty and enteropathies]. 276 94

In the present study Farnolith (a granular powder consisting of different dietary fibres) was given to normals (n = 6), patients suffering from absorptive hypercalciuria type I (n = 6) and to one patient suffering from renal hypercalciuria. Farnolith binds calcium and reduces the calcium absorption from the intestine. In normals the urine- and serum parameters of calcium metabolism (total- and ionised calcium, parathyroid hormone and vitamin-D-metabolites) remained unchanged. In patients suffering from absorptive hypercalciuria type I a significant reduction of hypercalciuria was found; oxalic acid excretion had decreased as well. Lowered parathyroid hormone values returned to normal, vitamin-D-metabolites remained unaffected. In one patient suffering from renal hypercalciuria parathyroid hormone and 1,25-dihydroxy-vitamin D values increased, calcium excretion had not decreased, though. Our investigation shows that Farnolith is suitable for the treatment of absorptive hypercalciuria. Calcium homoeostasis is returned to normal by Farnolith, at the same time it does not produce secondary hyperoxaluria (as e.g. sodium cellulose phosphate). Patients with primary renal calcium loss should not be treated by Farnolith.
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PMID:Calcium metabolism in normal and in hypercalciuric patients on Farnolith, a dietary fibre preparation. 285 67

The high incidence of renal lithiasis in hyperparathyroidism (55 p. 100) suggests that PTH plays a causal role in stone production. It also motivates a systematic search for primary hyperparathyroidism in all patients with renal stones although it is only found in about 7 p. 100 of cases. PTH acts through the stimulation of 1.25(OH)2 vitamin D production and therefore, the absorption of calcium from the intestine, which in turn increases the filtrable calcium, hence the calciuria. In renal stones, in general, hypercalciuria represents one of the major metabolic disturbances, besides the hyperoxaluria, hyperuricosuria and the reduction of the inhibitors of crystallization. However, hypercalciuria is rarely the indirect result of excess PTH. It is usually caused by increased dietary ingestion of NaCl, meat, calcium and possibly carbohydrates.
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PMID:[Renal lithiasis in idiopathic hypercalciuria and primary hyperparathyroidism]. 376 88

1. Vitamin D seems to play an essential role in the pathogenesis of idiopathic hypercalciuria at least in part via intestinal hyperabsorption of calcium. Hyperabsorption of calcium, in turn, might enhance the intestinal uptake of free oxalate, thus leading to hyperoxaluria. To verify this hypothesis we studied 75 calcium-stone-formers subdivided as follows: group 1 (15 patients) with isolated hyperoxaluria; group 2 (25 patients) with hyperoxaluria and hypercalciuria; group 3 (22 patients) with isolated hypercalciuria; group 4 (12 patients) with no metabolic abnormalities. 2. As expected, urinary calcium excretion differed in the various groups (P < 0.001), being highest in groups 2 and 3; urinary oxalate excretion, by definition highest in groups 1 and 2, was even more pronounced in group 2 than in group 1 (P < 0.05). Although in the normal range, the serum 1,25-dihydroxyvitamin D concentration was higher (P < 0.001) in the two hypercalciuric groups (2 and 3), showing peak levels in group 2. 3. When the data from the 75 stone-formers were pooled, there was a positive correlation between the serum concentration of 1,25-dihydroxyvitamin D and urinary calcium excretion (P < 0.001) and urinary oxalate excretion (P < 0.003), the latter relationship also being present when only the two hypercalciuric groups (groups 2 and 3) were considered together (P < 0.05). 4. Our data seem to confirm a relevant role for the vitamin D system in the pathogenesis of calcium nephrolithiasis due to increased intestinal calcium absorption, but also because this in turn induces a greater intestinal absorption of oxalate, thus leading to the occurrence or exacerbation of hyperoxaluria.
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PMID:Possible link between vitamin D and hyperoxaluria in patients with renal stone disease. 838 34

The treatment of X-linked hypophosphatemia (XLH) consists of phosphate and vitamin D3 derivatives. Transient hypercalciuria and hypercalcemia are well-known signs of vitamin D intoxication. Despite urinary calcium excretion control, the danger of nephrocalcinosis in treated patients has been emphasized. It has recently been suggested that hyperoxaluria might be a causative factor of nephrocalcinosis other than calcium in phosphate-treated XLH patients. We measured urinary oxalate and phosphate excretion in 12 patients with the syndrome of hereditary hypophosphatemic rickets with hypercalciuria (HHRH) receiving only oral phosphates and in 5 XLH patients receiving both oral phosphates and vitamin D. No correlation was found between the dosage of phosphate supplements or urinary phosphate excretion and urinary oxalate excretion, in either group of patients. Nephrocalcinosis, presenting as hyperechogenicity of the medullary pyramids, was found in 2 of the 5 XLH patients and only in 2 HHRH patients who had been treated with excessive doses of vitamin D2 and calcium, prior to the true diagnosis being established. We conclude: (1) hyperoxaluria is not a cause of nephrocalcinosis in phosphate-treated patients with hereditary hypophosphatemic rickets; (2) prolonged phosphate treatment alone does not induce nephrocalcinosis in HHRH patients, and (3) we believe that in XLH patients, nephrocalcinosis is essentially due to vitamin D overdosage at some stage, or noncompliance in phosphate intake, leading to repeated undetected hypercalciuric periods.
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PMID:Hyperoxaluria is not a cause of nephrocalcinosis in phosphate-treated patients with hereditary hypophosphatemic rickets. 839 9

Calcium urolithiasis is often associated with increased intestinal absorption and urine excretion of calcium, and has been suggested to result from increased vitamin D production. The role of the enzyme 1 alpha-hydroxylase, the rate-limiting step in active vitamin D production, was evaluated in 36 families, including 28 sibships with at least a pair of affected sibs, using qualitative and quantitative trait linkage analyses. Sibs with a verified calcium urolithiasis passage (n = 117) had higher 24-h calciuria (P = 0.03), oxaluria (P = 0.02), fasting and postcalcium loading urine calcium/creatinine (Ca/cr) ratios (P = 0.008 and P = 0.002, respectively), and serum 1,25(OH)2 vitamin D levels (P = 0.02) compared with nonstone-forming sibs (n = 120). Markers from a 9-centiMorgan interval encompassing the VDD1 locus on chromosome 12q13-14 (putative 1 alpha-hydroxylase) were analyzed in 28 sibships (146 sib pairs) of single and recurrent stone formers and in 14 sibships (65 sib pairs) with recurrent-only (> or = 3 episodes) stone-forming sibs. Two-point and multipoint analyses did not reveal excess in alleles shared among affected sibs at the VDD1 locus. Linkage of stone formation to the VDD1 locus could be excluded, respectively, with a lambda d of 2.0 (single and recurrent stone formers) and 3.25 (recurrent stone formers). Quantitative trait analyses revealed no evidence for linkage to 24-h calciuria and oxaluria, serum 1,25(OH)2 vitamin D levels, and Ca/cr ratios. This study shows absence of linkage of the putative 1 alpha-hydroxylase locus to calcium stone formation or to quantitative traits associated with idiopathic hypercalciuria. In addition, there is coaggregation of calciuric and oxaluric phenotypes with stone formation.
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PMID:The 1 alpha-hydroxylase locus is not linked to calcium stone formation or calciuric phenotypes in French-Canadian families. 951 4

Various endo- and exogenous factors play a role in the urinary stones formation tract. The aim of the study was to define the type and frequency of hyperexcretion of lithogenic substances in school children population and to determine an influence of risk factors on hyperexcretion of crystallizing substances. The study included 220 school children. Preurolithiasis state (PS) was found in 30% children. The most frequently hyperoxaluria, hyperuricosuria and hypercalciuria were diagnosed and it may be connected with abnormal nutritional habits, excessive application of multivitamins, vitamin D and calcium, disturbances in drinking water chemical composition (higher amount of calcium, smaller amount of magnesium, abnormal pH). Urinary tract infections, particularly in children with obstructive uropathy are an important risk factor in the examined population. Positive familial history of urolithiasis in 43.3% children may indicate for the important role of the genetic factor in the pathogenesis of the disease.
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PMID:[The role of environmental factors in the formation of kidney calculi]. 1089 97


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