Enteric and mild hyperoxaluria.

R A Sutton; V R Walker

Home/Archive/PubMed

PubMed · 7783697

Enteric and mild hyperoxaluria.

R A Sutton·V R Walker

View original source ↗Export metadata ↓

Abstract

Enteric hyperoxaluria complicates extensive disease or resection of the small intestine in the presence of an intact colon, and is associated with calcium oxalate nephrolithiasis. In addition to hyperoxaluria these patients have a low urine volume, low urinary ionic strength and hypocitraturia. Many forms of treatment have been recommended, but none has been subjected to a prospective clinical trial. Mild idiopathic hyperoxaluria is reported in 8-50% of idiopathic calcium oxalate stoneformers. Several pathophysiological mechanisms have been proposed, including low dietary calcium and possible oxalate transport defects in the gut and/or the kidney. Mild hyperoxaluria, or a high oxalate:calcium ratio in the urine, may be particularly important risk factors for calcium oxalate stone formation; an approach to the correction of these abnormalities is proposed.

Explore related subjects

Calcium Oxalate Calcium, Dietary Humans Hyperoxaluria Incidence Intestinal Absorption Oxalates Prevalence Urinary Calculi Vitamin B 6 Deficiency Journal Article Review

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

R A Sutton, V R Walker. 1994. Enteric and mild hyperoxaluria.. https://pubmed.ncbi.nlm.nih.gov/7783697/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2003

Urinary saturation and risk factors for calcium oxalate stone disease based on spot and 24-hour urine specimens.

In 222 random spot urine specimens, the calcium concentration and calcium oxalate saturation [DG(CaOx)] were significantly higher among stone formers than among non-stone formers, while the citrate and creatinine-corrected citrate concentrations were lower. In 188 24-hour urine specimens, magnesium excretion was lower among stone formers than non-stone formers, while the creatinine-corrected calcium concentration and DG(CaOx) were higher. Among stone formers, there was no gender difference in the urinary concentrations of calcium, oxalate, citrate, magnesium, and DG(CaOx), but the creatinine-corrected calcium, citrate, and magnesium concentrations were higher in women, as well as 24-hour citrate excretion. The levels of calcium and oxalate have a major influence on DG(CaOx), while citrate and magnesium levels have a minor influence. DG(CaOx) was correlated with calcium and oxalate excretion, as well as with the creatinine-corrected calcium and oxalate concentrations. Approximately 5% of 24-hour urine specimens showed critical supersaturation, 80% showed metastable supersaturation, and 15% were unsaturated. Hypercalciuria or hyperoxaluria was fairly common (30% and 40%) in critically supersaturated urine, while it was less common (22.4% and 8.6%) in metastably supersaturated urine and was not detected in unsaturated urine. Hypocitraturia and/or hypomagnesiuria was more common (63.8-80%) at any saturation. The urinary calcium, oxalate, and citrate concentrations, as well as the creatinine-corrected calcium, oxalate, citrate, and magnesium concentrations and DG(CaOx), showed a significant correlation between 57 paired early morning spot urine and 24-hour urine specimens. The creatinine-corrected calcium and citrate concentrations of the early morning urine specimens were significantly correlated with the levels of calcium and citrate excretion in the paired 24-hour urine specimens. In conclusion, no parameter other than urinary saturation gives more than a vague indication of the risk of lithogenesis, so DG(CaOx) in either early morning urine or 24-hour urine specimens appears to be the best predictor of stone risk. Finally, the creatinine-corrected calcium and citrate concentrations in early morning urine can be used as a substitute for measuring 24-hour excretion.

Calcium Oxalate↗

PubMed2003

Adhesion between molecules and calcium oxalate crystals: critical interactions in kidney stone formation.

Kidney stones are crystal aggregates, most commonly containing calcium oxalate monohydrate (COM) crystals as the primary constituent. Notably, in vitro studies have suggested that anionic molecules or macromolecules with substantial anionic functionality (e.g., carboxylate) play an important role in crystal aggregation and crystal attachment to renal epithelial cells. Furthermore, kidney stones contain measurable amounts of carboxylate-rich proteins that may serve as adhesives and promote aggregation of COM crystals. Atomic force microscopy (AFM) measurements of adhesion forces between tip-immobilized molecules and the COM (100) surface in aqueous media, described herein, reveal the effect of functional groups on adhesion and support an important role for the carboxylate group in processes responsible for kidney stone formation, specifically macromolecule-mediated adhesion of COM crystals to cells and crystal aggregation. The presence of poly(aspartic acid) during force measurements results in a reduction in the adhesion force measured for carboxylate-modified tips, consistent with the blocking of binding sites on the COM (100) surface by the carboxylate-rich polymer. This competitive binding behavior mimics the known reduction in attachment of COM crystals to renal epithelial cells in the presence of carboxylate-rich urinary macromolecules. These results suggest a feasible methodology for identifying the most important crystal surface-macromolecule combinations related to stone formation.

Calcium Oxalate↗

PubMed2003

Determination of calcium oxalate (mono- and dihydrate) in mixtures with magnesium ammonium phosphate or uric acid: the use of simultaneous thermal analysis in urinary calculi.

BACKGROUND: The human urinary calculi are mainly formed from calcium oxalate, magnesium ammonium phosphate hexahydrate (MAPH) and uric acid (UA) crystals. It is important for the physician and surgeon to distinguish the two types of hydrates of calcium oxalate, mainly mono- (COM, Whewellite) and dihydrate (COD, Weddelite). This is because COM stones are evacuated two times more frequently than COD, which sometimes needs to be extracted surgically. METHODS: Thermal analysis techniques, such as Differential Thermal Analysis (DTA) and Thermogravimetry (TG), are considered the best techniques for the characterization of the two hydrates of calcium oxalate. A simultaneous thermal analysis method (TG-DTA) was applied to determine the percentage of each hydrate (COM and COD) when present together, in the presence of MAPH or in the presence of UA. RESULTS: The results performed on 156 urinary calculi were as follows (according to the major component): 74.36%, 7.05% and 10.26% for calcium oxalate hydrate, UA and MAPH, respectively. The COD/COM ratios were 0.75 and 1.75, when they are present in mixtures with UA and MAPH, respectively. CONCLUSIONS: Fourier transform infrared (FTIR) and X-ray diffraction (XRD) have been used in urinary calculi analysis. Simultaneous thermal analysis TG-DTA would be an alternative method for quantitative determination of the two types of calcium oxalate in urinary stones.

Calcium Oxalate↗