Effects of Human Urine on Aggregation of Calcium Oxalate Crystals

1986 ◽  
Vol 135 (1) ◽  
pp. 69-71 ◽  
Author(s):  
Kurt E. Springmann ◽  
George W. Drach ◽  
Beth Gottung ◽  
Alan D. Randolph
2021 ◽  
Vol 12 (5) ◽  
pp. 5836-5844

Calcium oxalate is the most common type of urolithiasis. The crystallization process includes nucleation, growth, and the aggregation of crystals. This study has used Dolichos biflorus seeds as a functional beverage to explore the role of its bioactive substances on the crystallization process of calcium oxalate in managing urolithiasis. A human urine model of in vitro calcium oxalate crystals was used in the study. Phytochemical screening of Functional beverage of Dolichos biflorus seeds was performed, and antioxidant activity was evaluated by measuring DPPH radical-scavenging activity, reducing power assay, and Hydrogen peroxide scavenging activity. Functional beverage of Dolichos biflorus seeds inhibited crystallization process by reducing aggregation of calcium oxalate crystals. The reduction in crystals aggregation helps prevent urolithiasis by keeping the crystals dispersed in the urine, controlling their size, and facilitating expulsion from the urinary tract. The results showed that the Functional beverage of Dolichos biflorus seeds has a significant quantity of flavonoids, glycosides, etc., and also possesses a significant antioxidant activity as evaluated by employing different antioxidant assays. Therefore, our findings suggested that the functional beverage of Dolichos biflorus seeds exhibited antiurolithiatic activity through inhibition of the crystallization process of the calcium oxalate process and significant antioxidant potential.


2002 ◽  
Vol 167 (1) ◽  
pp. 317-321 ◽  
Author(s):  
MARIA C. MARTINS ◽  
ANTHONY A. MEYERS ◽  
NATALIE A. WHALLEY ◽  
ALLEN L. RODGERS

1982 ◽  
Vol 62 (4) ◽  
pp. 421-425 ◽  
Author(s):  
P. C. Hallson ◽  
G. A. Rose ◽  
S. Sulaiman

1. Samples of fresh human urine were treated with immobilized uricase to lower urate concentration. Urate was added to yield low, normal and high urate samples. 2. Each sample was rapidly evaporated at pH 5.3 to standard osmolality and the yield of calcium oxalate crystals measured either by semi-quantitative microscopy or fully quantitative radioisotope techniques. 3. Increase of urinary urate did not increase the calcium oxalate crystals formed and may even have had an opposite effect. 4. Allantoin was without significant effect upon calcium oxalate crystal formation. 5. These data provide no support for the suggestion that reducing urate concentrations in the urine may be of value in treatment of patients with calcium oxalate stones.


1997 ◽  
Vol 92 (2) ◽  
pp. 205-213 ◽  
Author(s):  
Phulwinder K. Grover ◽  
Rosemary L. Ryall

1. The aim of this study was to determine whether seed crystals of uric acid or monosodium urate promote the epitaxial deposition of calcium oxalate in undiluted human urine. The effects of seed crystals of uric acid, monosodium urate or calcium oxalate on calcium oxalate crystallization induced in pooled 24-h urine samples collected from six healthy men were determined by [14C]oxalate deposition and Coulter counter particle analysis. The precipitated crystals were examined by scanning electron microscopy. 2. Seed crystals of uric acid, monosodium urate and calcium oxalate increased the precipitated particle volume in comparison with the control containing no seeds by 13.6%, 56.8% and 206.5% respectively, whereas the deposition of [14C]oxalate in these samples relative to the control was 1.4% (P < 0.05), 5.2% (P < 0.01) and 54% (P < 0.001) respectively. The crystalline particles deposited in the presence of monosodium urate seeds were smaller than those in the control samples. Scanning electron microscopy showed that large aggregates of calcium oxalate were formed in the presence of calcium oxalate seeds, which themselves were not visible. In contrast, monosodium urate and, to a lesser extent, uric acid seeds were scattered free on the membrane surfaces and attached like barnacles upon the surface of the calcium oxalate crystals. 3. It was concluded that seed crystals of monosodium urate and uric acid do not promote calcium oxalate deposition to a physiologically significant degree in urine. Howsever, binding of monosodium urate and uric acid crystals and their subsequent enclosure within actively growing calcium oxalate crystals might occur in vivo, thereby explaining the occurrence of mixed urate/oxalate stones.


1995 ◽  
Vol 89 (5) ◽  
pp. 533-541 ◽  
Author(s):  
Rosemary L. Ryall ◽  
Phulwinder K. Grover ◽  
Alan M. F. Stapleton ◽  
Dianne K. Barrell ◽  
Yulu Tang ◽  
...  

1. The urinary F1 activation peptide of prothrombin is the predominant protein incorporated into calcium oxalate crystals precipitated from human urine. The aim of this study was to examine the effect of pure urinary prothrombin F1 on calcium oxalate crystallization in human urine. 2. Urinary prothrombin F1 was purified from demineralized calcium oxalate crystals precipitated from human urine, and its effects on calcium oxalate crystallization induced by addition of an oxalate load were tested in undiluted, ultrafiltered urine from healthy men, at final concentrations of 0 to 10 mg/l. 3. Urinary prothrombin F1 did not affect the amount of oxalate required to induce crystallization, but the volume of material deposited increased in proportion to increasing concentrations of urinary prothrombin F1. However, the mean particle size decreased in reverse order: this was confirmed by scanning electron microscopy, which showed it to be the result of a reduction in crystal aggregation rather than in the size of individual crystals. Analysis of 14C-oxalate data revealed a dose-dependent decrease in calcium oxalate deposition with an increase in urinary prothrombin F1 concentration, indicating that the increase in particle volume recorded by the Coulter Counter resulted from inclusion of urinary prothrombin F1 into the crystalline architecture, rather than increased deposition of calcium oxalate. 4. It was concluded that urinary prothrombin F1 may be an important macromolecular determinant of stone formation.


Author(s):  
H. J. Arnott ◽  
M. A. Webb ◽  
L. E. Lopez

Many papers have been published on the structure of calcium oxalate crystals in plants, however, few deal with the early development of crystals. Large numbers of idioblastic calcium oxalate crystal cells are found in the leaves of Vitis mustangensis, V. labrusca and V. vulpina. A crystal idioblast, or raphide cell, will produce 150-300 needle-like calcium oxalate crystals within a central vacuole. Each raphide crystal is autonomous, having been produced in a separate membrane-defined crystal chamber; the idioblast''s crystal complement is collectively embedded in a water soluble glycoprotein matrix which fills the vacuole. The crystals are twins, each having a pointed and a bidentate end (Fig 1); when mature they are about 0.5-1.2 μn in diameter and 30-70 μm in length. Crystal bundles, i.e., crystals and their matrix, can be isolated from leaves using 100% ETOH. If the bundles are treated with H2O the matrix surrounding the crystals rapidly disperses.


Sign in / Sign up

Export Citation Format

Share Document