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

Using the ambulatory protocol previously described, 241 patients with nephrolithiasis were evaluated. They could be categorized into 10 groups from the results obtained. Absorptive hypercalciuria type I (87 per cent male) comprised 24.5 per cent and was characterized by normocalcemia, normal fasting urinary calcium (less than 0.11 mg/100 ml glomerular filtration), an exaggerated urinary calcium following an oral calcium load (greater than 0.20 mg/mg creatinine), normal urinary cyclic adenosine monophosphate (AMP) (less than 5.4 nmol/100 ml glomerular filtration) and serum parathyroid hormone (PTH), and hypercalciuria (greater than 200 mg/day during a calcium- and sodium-restricted diet). Absorptive hypercalciuria type II (50 per cent male) accounted for 29.8 per cent; its biochemical features were the same as those for absorptive hypercalciuria type I, except for normocalciuria during a restricted diet and low urine volume (1.42 +/- 0.55 SD liter/day). Renal hypercalciuria (56 per cent male), disclosed in 8.3 per cent, was represented by normocalcemia and high values for fasting urinary calcium (0.160 +/- 0.054 mg/100 ml glomerular filtration), urinary cyclic AMP (6.80 +/- 2.10 nmol/100 ml glomerular filtration) and serum PTH. Primary hyperparathyroidism (57 per cent female), accounted for 5.8 per cent, typically included hypercalcemia, hypophosphatemia, hypercalciuria and high urinary cyclic AMP. Hyperuricosuric calcium urolithiasis (100 per cent male) comprised 8.7 per cent, and was characterized by hyperuricosuria (776 +/- 164 mg/day) and urinary pH exceeding pK for uric acid (5.91 +/- 0.33). In enteric hyperoxaluria (60 per cent female), encountered in 2.1 per cent of cases, urinary oxalate was increased (6.29 +/- 13.2 mg/day). Noncalcium-containing stones were found in 2.1 per cent of the patients with uric acid lithiasis (100 per cent male) and in another 2.1 per cent of the patients with infection lithiasis (60 per cent female). These conditions were typified by low urinary pH (5.29 +/- 0.12) and high urinary pH (6.69 +/- 1.16), respectively. Renal tubular acidosis was found in one patient (male, 0.4 per cent). In 10.8 per cent of the patients (81 per cent male), no metabolic abnormality could be found, although urine volume was low (1.41 +/- 0.51 liter/day). Hypercalciuria could not be differentiated between absorptive hypercalciuria and renal hypercalciuria in 5.4 per cent of the patients. Thus, this ambulatory protocol disclosed a physiologic disturbance in nearly 90 per cent of the cases and provided a definitive diagnosis in 95 per cent of the patients.
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PMID:Ambulatory evaluation of nephrolithiasis. Classification, clinical presentation and diagnostic criteria. 624 14

The urinary excretion of oxalate, calcium, citrate, magnesium, urate and creatinine and the inhibition of calcium oxalate crystal growth were determined in 30 patients operated with three different types of jejunoileal bypass. In addition the ion-activity products of calcium oxalate and calcium oxalate saturation were calculated. 15 of the patients had formed urolithiasis postoperatively. The patients were investigated on an out-patient basis with their ordinary diet. All patients had hyperoxaluria. The oxalate excretion did not seem to decrease with time after operation. The patients operated with a biliointestinal shunt had a significantly higher excretion of oxalate than those with the other two types of operation, indicating that variations in the anatomy of the small intestine after jejunoileal bypass might result in different absorption of oxalate or oxalate precursors. Urinary oxalate, calcium oxalate saturation and ion-activity products were higher whereas the excretion of calcium, magnesium and citrate was lower in patients than in controls. The urine volumes, excretion of creatinine and urate and inhibition of calcium oxalate crystal growth were equal in patients and controls. Analogous urine composition was found in patients both with and without urolithiasis with the exception of a higher magnesium excretion observed in stone formers.
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PMID:Urine composition following jejunoileal bypass. 682 41

Balance studies and oxalate loading tests were carried out in order to define the pathogenesis of hyperoxaluria in 8 patients with jejunoileal bypass surgery for severe obesity; two healthy volunteers were also studied. In the bypass patients, urinary oxalate was markedly elevated (118 +/- 43 mg/day, mean +/- SD) when they were on a high oxalate diet (252 mg/day). Hyperabsorption of dietary oxalate was confirmed by the markedly increased urinary recovery of [14C]oxalate given in a test meal. In addition, the oxalate radioactivity was excreted in urine far more slowly than in healthy volunteers, suggesting that the colon was a major site of oxalate absorption. Elevated urinary oxalate excretion persisted, averaging 38 +/- 12 mg/day, despite ingestion of a very low oxalate diet (approximately 6 mg/day), suggesting that the diet contained "oxalogenic" substances other than preformed dietary oxalate which also contributed to dietary oxalate in these patients. Urinary oxalate decreased in 7 of 8 patients, however, when protein-rich foods were removed from the diet, suggesting that at least one dietary factor was digestive products of protein or creatinine. These results confirm the current view that in patients with hyperoxaluria secondary to jejunoileal bypass, the majority of urinary oxalate derives from dietary oxalate that is absorbed from the colon. Tissue or bacterial production of oxalate or an oxalate precursor from dietary constituents associated with protein, however, also appears to contribute to urinary oxalate. The results provide an explanation for the reported difficulty of eliminating secondary hyperoxaluria by restriction of dietary oxalate alone.
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PMID:Complex pathogenesis of hyperoxaluria after jejunoileal bypass surgery. Oxalogenic substances in diet contribute to urinary oxalate. 684 9

The circadian (circannual for oxalic acid) variations of 13 urinary variables (volume, creatinine, calcium, oxalic acid, glycolic acid, 17-ketosteroids, 17-hydroxycorticosteroids, phosphates, urea, uric acid, chloride, sodium, and potassium) have been documented in 7 calcium oxalate renal stone formers and 7 healthy men (control group). Urine was collected every 4 h over a period of 24 h. All subjects had the same synchronization: diurnal activity from 07(00) to 23(00) +/- 1 h and nocturnal rest; meals were given at fixed clock hours (08(00), 12(30) and 20(00) +/- 1 h). A statistically-significant rhythm (p less than 0.05) was validated for all variables except urea and calcium in healthy men. In renal stone formers, 6 variables (calcium, oxalic acid, and glycolic acid in particular) had no detectable circadian rhythm. However, a periodicity of c. 8 h (ultradian rhythm) was demonstrated for calcium and oxalic acid with peaks being located around 02(00), 10(00), and 18(00). No circannual variations in oxalic acid output could be observed. The present study shows an alteration of the periodicity of calcium and oxalic metabolisms, i.e. the loss of a circadian (24-h) rhythm and the occurrence of an ultradian rhythm of 8 h. The risk of calcium-oxalate crystallisation appears thus greater at 02(00), 10(00), and 18(00). Furthermore, any study dealing with oxalic acid excretion should state the season of urine collection when comparing renal stone formers and healthy subjects, as significant differences in oxaluria may appear during the summer months and not during the rest of the year.
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PMID:Alterations in circadian rhythmicity in calcium oxalate renal stone formers. 686 98

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

Ten car mechanics frequently exposed to glycol-based cooling liquids were followed during a workshift. Airborne ethylene and propylene glycol concentrations in the car mechanics' environment were measured. The car mechanics gave urine samples after the workshift and their excretion of ethylene glycol, propylene glycol, oxalic acid, calcium and ammonia was analysed and compared to that of unexposed office workers. Urinary succinate dehydrogenase activity and glycosaminoglycans were also measured in both groups. Airborne ethylene and propylene glycol concentrations in the car mechanics' environment were negligible. Urinary ethylene glycol excretion in exposed workers was significantly higher than that in unexposed workers, but propylene glycol excretion was at the same levels as in controls. In the exposed group, the excretion of the end metabolite of ethylene glycol, oxalic acid (47 +/- 11 mmol/mol creatinine, mean +/- SD, n = 10) differed slightly from that of controls (36 +/- 14 mmol/mol creatinine, mean +/- SD, n = 10). Urinary excretion of ammonia was higher among exposed workers than office workers. The excretion of calcium did not differ from that of controls. A marginally decreased urinary succinate dehydrogenase activity was found in the exposed men. The excretion of glycosaminoglycans was significantly lower in exposed workers. Therefore, it seems that ethylene glycol is absorbed by skin contact. The internal body burden is associated with oxaluria and increased ammoniagenesis typical of chronic acidosis.
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PMID:Exposure to glycols and their renal effects in motor servicing workers. 757 1

To evaluate the clinical utility of in vitro calcium oxalate monohydrate (COM) crystallization kinetics measurements and to determine the effect of quantitative removal of urinary Tamm-Horsfall glycoprotein on such measurements, we examined 24-hour, room temperature urine collections of patients from our Stone Clinic and of normal subjects from our research laboratories at Ochsner Medical Institutions in New Orleans, LA, and compared their COM kinetic parameters in vitro before and after urine ultrafiltration (30 kd). Data from 53 calcium oxalate stone-forming patients (26% women; mean age, 47 years) who demonstrated radiographic or other evidence of forming at least one stone were compared with data from 22 healthy volunteers (25% women; mean age, 40 years). Hypercalciuria (> 7.5 mm/24 hr), hyperoxaluria (> 0.5 mm/24 hr), and hypocitraturia (< 2.0 mm/24 hr) were present in 38%, 26%, and 26% of the patient population, respectively. Urinary creatinine, urate, calcium, citrate, phosphate, oxalate, pH, volume, total immunoreactive-disaggregated Tamm-Horsfall glycoprotein, and the urine's effects on COM solubility, percent crystal growth inhibition, and crystal agglomeration inhibition [tm] were determined. Calcium oxalate monohydrate agglomeration inhibition, [tm], was reduced in stone-forming patients. It decreased with increasing stone frequency, making [tm] a useful tool for measuring the risk of stone recurrence. Urinary Tamm-Horsfall glycoprotein and citrate concentrations were linearly related to COM agglomeration inhibition. Their effects were synergistic. Tamm-Horsfall glycoprotein removal from urine reduced COM agglomeration inhibition dramatically. Alkali therapy increased urinary citrate concentration and increased [tm].(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Calcium oxalate stone agglomeration reflects stone-forming activity: citrate inhibition depends on macromolecules larger than 30 kilodalton. 798 66

Evidence for the suitability of spot urines for selective screening in children was obtained by comparing the 24-hour urinary oxalate excretion with the ratio of urinary oxalate to creatinine [mmol/mol] in spontaneously voided urine samples. Spot urines of 169 healthy children aged 1 day to 13 years were analysed in order to establish reference values for the urinary oxalate/creatinine ratio in relation to age and body surface area. Oxalate was measured by automated ion chromatography. Results showed an inverse relationship between the oxalate/creatinine ratio and age. The highest ratios, 131 +/- 57 mmol/mol (mean +/- 2 SD), were found in infants. At age two years, the ratio was 84 +/- 55, at age five years 56 +/- 35, and for children older than ten years 42 +/- 31. This finding can be explained by the gain of muscle mass and hence increased creatinine production with increasing age. Data for the urinary oxalate/creatinine ratio are presented according to body surface area for the assessment of children with abnormal growth. In 19 urine samples from nine patients with primary hyperoxaluria, the oxalate/creatinine ratio greatly exceeded (286-2022 mmol/mol) the above reference ranges. We therefore propose the determination of the oxalate/creatinine ratio in spot urines for the selective screening for hyperoxaluria in children with nephrocalcinosis or urolithiasis.
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PMID:Determination of oxalate excretion in spot urines of healthy children by ion chromatography. 816 90

Aim of the study was to establish normal values for calcium/creatinine (Ca/cr) and oxalate/creatinine (Ox/cr) ratio in infants and children. Urine probes of 416 healthy children (25 infants aged 1-7 days and 391 children aged 1 month-14.5 years) were analysed. Oxalate was measured by ion-chromatography. Urinary Ca2+/cr was normally distributed, Ox/cr had log-normal distribution. Ca/cr was the lowest in the first days of life, the highest between 7 month-1.5 years (mean +/- SD = 0.39 +/- 0.28 mmol/mmol), a slight decrease could be observed until 14 years (0.34 +/- 0.18). The highest Ox/cr values were measured during the first month of life (geometric mean/range/ = 133 /61-280 mmol/mmol/), followed by gradual decrease until 14 years (25/6-73/). The measurement of Ca2+/cr and Ox/cr in first morning urine samples is suitable for screening of hypercalciuria and hyperoxaluria. The interpretation of the values requires age specific reference values. Both calcium and oxalate determinations should be the part of the evaluation of patients with hematuria, hypercalciuria or nephrolithiasis.
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PMID:[Normal values of calcium and oxalate excretion in children]. 865 14

Primary hyperoxaluria type 1 (PH 1) is complicated by a high rate of early end-stage renal failure (ESRF). In ESRF combined liver kidney transplantation has emerged as treatment of choice for teenagers and adults. In chronic renal failure (CRF) and for small children the situation is less clear. We report on three isolated liver transplantations and show the data of young children from the European Registry for liver transplantation in PH 1. Patient #1 developed ESRF at 3 months of age. Deficiency of alanine:glyoxylate aminotransferase proved PH 1. Progressive bone disease developed and the boy received a living related liver graft (LRLTx) at age two. Due to recurrent cholangitis kidney transplantation (KTx) is currently not feasible. Plasma oxalate decreased after LRLTx indicating correction of the metabolic defect. Patient #2 was diagnosed at the age of 14 months. He had nephrocalcinosis and hyperglycolic hyperoxaluria. Two years later he developed ESRF. At 5 years of age isolated liver transplantation was performed as a first step of therapy. Due to prolonged warm ischemia time organ function was poor. A severe bleeding complicated the course. The child died four weeks after transplantation from untreatable CMV septicemia. Patient #3 was evaluated for failure to thrive at 6 months of age. Urinary oxalate/creatinine ratio was 705 mumol/mol and gave rise to the diagnosis of PH 1. Renal failure slowly progressed to a creatinine clearance of 20 ml/min/1.73 m2 at 8 years, when liver transplantation (LTx) was performed. Four months later, GFR has not changed. Liver function and urinary oxalate/creatinine ratio are normal. Slowly deteriorating chronic renal failure can be stabilized through isolated liver transplantation and thus the rapid need for KTx will at least be delayed. Even more important, normalization of the oxalate metabolism prevents extrarenal oxalate deposits during renal failure.
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PMID:Transplantation procedures in primary hyperoxaluria type 1. 883 45


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