scholarly journals Effect of calcium content of diet on crystal formation in urine of patients with calcium oxalate stones: a randomized crossover clinical trial

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Sathish Kumar Gopala ◽  
Jim Joe
Keyword(s):  
Clinical Trial ◽  
Calcium Oxalate ◽  
Kidney Stone ◽  
Stone Formation ◽  
Calcium Content ◽  
Urine Samples ◽  
Creatinine Ratio ◽  
Calcium Oxalate Stones ◽  
High Calcium ◽  
Kidney Stone Formation

Abstract Background Patients with idiopathic calcium oxalate stones are advised to consume a low-oxalate diet to prevent recurrence. In this study, on patients with calcium oxalate stones we have attempted to determine the effect of calcium content of diet on the formation of calcium oxalate crystals in urine by in vitro supersaturation study of fresh postprandial urine samples and observing the morphology of the crystals formed using polarized optical microscopy. Methods The trial was conducted as a prospective interventional randomised crossover clinical trial in a repeated measures design. Sixty patients with calcium oxalate stones and no metabolic abnormalities in urine treated by lithotripsy at a tertiary care centre during the period May 2016 to May 2019 were recruited. Following a 14 h overnight fasting, urine samples were collected after providing the patient with either a low- or high-calcium meal for breakfast followed four hours later, by high-oxalate meal for lunch. Urine was tested for multiple parameters including urine pH, specific gravity, calcium/creatinine ratio and supersaturation of urine with sodium oxalate followed by optical density measurement by spectrophotometry and microscopic analysis of crystals formed. Results Optical density values and calcium/creatinine ratio of urine samples obtained after high-calcium meal are significantly higher than in corresponding sample obtained after low-calcium meal (p < 0.001). These findings were reflected in the morphology of formed crystals in their size, shape and number. When urinary calcium levels were low, no crystals were formed during supersaturation study of postprandial urine samples following a high-oxalate diet. Conclusions High calcium content in diet significantly contributes to kidney stone formation. There is a lower risk of kidney stone formation with a low-calcium meal even on consumption of a high-oxalate diet.

scholarly journals Protective Effect of Degraded Porphyra yezoensis Polysaccharides on the Oxidative Damage of Renal Epithelial Cells and on the Adhesion and Endocytosis of Nanocalcium Oxalate Crystals

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Qian-Long Peng ◽  
Chuang-Ye Li ◽  
Yao-Wang Zhao ◽  
Xin-Yuan Sun ◽  
Hong Liu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Epithelial Cells ◽  
Oxidative Damage ◽  
Protective Effect ◽  
Calcium Oxalate ◽  
Kidney Stone ◽  
Stone Formation ◽  
Porphyra Yezoensis ◽  
Renal Epithelial Cells ◽  
Kidney Stone Formation

The protective effects of Porphyra yezoensis polysaccharides (PYPs) with molecular weights of 576.2 (PYP1), 105.4 (PYP2), 22.47 (PYP3), and 3.89 kDa (PYP4) on the oxidative damage of human kidney proximal tubular epithelial (HK-2) cells and the differences in adherence and endocytosis of HK-2 cells to calcium oxalate monohydrate crystals before and after protection were investigated. Results showed that PYPs can effectively reduce the oxidative damage of oxalic acid to HK-2 cells. Under the preprotection of PYPs, cell viability increased, cell morphology improved, reactive oxygen species levels decreased, mitochondrial membrane potential increased, S phase cell arrest was inhibited, the cell apoptosis rate decreased, phosphatidylserine exposure reduced, the number of crystals adhered to the cell surface reduced, but the ability of cells to endocytose crystals enhanced. The lower the molecular weight, the better the protective effect of PYP. The results in this article indicated that PYPs can reduce the risk of kidney stone formation by protecting renal epithelial cells from oxidative damage and reducing calcium oxalate crystal adhesion, and PYP4 with the lowest molecular weight may be a potential drug for preventing kidney stone formation.

Effects of inter-α-inhibitor and several of its derivatives on calcium oxalate crystallization in vitro

2000 ◽  
Vol 98 (4) ◽  
pp. 471-480 ◽  
Author(s):  
Caroline DEAN ◽  
Jerry KANELLOS ◽  
Hung PHAM ◽  
Maria GOMES ◽  
Adrian OATES ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Kidney Stone ◽  
Stone Formation ◽  
Calcium Oxalate Crystallization ◽  
Sds Page ◽  
Kidney Stone Formation ◽  
Scanning Electron

The bikunin peptide chain of the protease inhibitor inter-α-inhibitor (∣α∣) has been reported to be an inhibitor of calcium oxalate (CaOx) crystallization, and hence has been proposed as having a role in CaOx kidney stone formation. However, further experimental evidence is required to assess if fragments of ∣α∣ other than bikunin may play a role in the regulation of crystallization events in stone formation. The aim of the present study was to assess the effects of ∣α∣ and several of its derivatives on CaOx crystallization in a seeded inorganic system and to compare these effects with those of a known inhibitor of crystallization, prothrombin. ∣α∣ was purified from a preparation of human plasma and fragmented by alkaline hydrolysis, and two of its peptide chains, bikunin and heavy chain 1 (H1), were purified further by HPLC. Their purity was confirmed by SDS/PAGE. Using Coulter counter and [14C]oxalate analysis and scanning electron microscopy, ∣α∣, its H1 chain and bikunin from urine and from plasma were shown to be relatively weak inhibitors of CaOx crystallization in vitro at expected physiological concentrations. It was concluded that members of the ∣α∣ family may not be as important in kidney stone formation as has been generally proposed, although further studies are required before a possible role for ∣α∣ and its fragments in stone formation can be unambiguously discounted.

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