Effect of Seed Crystals of Uric Acid and Monosodium Urate on the Crystallization of Calcium Oxalate in Undiluted Human Urine in Vitro

1997 ◽  
Vol 92 (2) ◽  
pp. 205-213 ◽  
Author(s):  
Phulwinder K. Grover ◽  
Rosemary L. Ryall
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Uric Acid ◽  
Calcium Oxalate ◽  
Human Urine ◽  
Monosodium Urate ◽  
Calcium Oxalate Crystals ◽  
Seed Crystals ◽  
Oxalate Crystals ◽  
Scanning Electron

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.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

scholarly journals Ovule Structure of Scotch thistle Onopordum acanthium L. (Cynareae, Asteraceae)

2016 ◽  
Vol 58 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Jolanta Kolczyk ◽  
Piotr Stolarczyk ◽  
Bartosz J. Płachno
Keyword(s):  
Electron Microscopy ◽  
Calcium Oxalate ◽  
Calcium Oxalate Crystals ◽  
Polarizing Microscopy ◽  
Onopordum Acanthium ◽  
Oxalate Crystals ◽  
Transmission Electron ◽  
Mature Ovule ◽  
Vacuolated Cells ◽  
Scanning Electron

AbstractStudies concerning the ultrastructure of the periendothelial zone integumentary cells of Asteraceae species are scarce. The aim was to check whether and/or what kinds of integument modifications occur inOnopordum acanthium. Ovule structure was investigated using light microscopy, scanning electron microscopy, transmission electron microscopy and histochemistry. For visualization of calcium oxalate crystals, the polarizing microscopy was used. The periendothelial zone of integument inO. acanthiumis well developed and composed of mucilage cells near the integumentary tapetum and large, highly vacuolated cells at the chalaza and therefore they differ from other integumentary cells. The cells of this zone lack starch and protein bodies. Periendothelial zone cells do not have calcium oxalate crystals, in contrast to other integument cells. The disintegration of periendothelial zone cells was observed in a mature ovule. The general ovule structure ofO. acanthiumis similar to other members of the subfamily Carduoideae, although it is different to “Taraxacum”, “Galinsoga” and “Ratibida” ovule types.

Developmental morphology of the flower of Anthurium jenmanii: a new element in our understanding of basal Araceae

Botany ◽  
2008 ◽  
Vol 86 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Denis Barabé ◽  
Christian Lacroix
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Floral Development ◽  
Developmental Morphology ◽  
Calcium Oxalate Crystals ◽  
Stages Of Development ◽  
Early Stages ◽  
Floral Primordia ◽  
Scanning Electron

The early stages of development of the inflorescence of Anthurium jenmanii Engl. were examined using scanning electron microscopy. The inflorescence of A. jenmanii consists of more than 100 flowers arranged in recognizable spirals. Each flower has four broad tepals enclosing four stamens that are not visible prior to anthesis. The gynoecium consists of two carpels. The floral primordia are first initiated on the lower portion of the inflorescence, they then increase in size and appear as transversely extended bulges. The two lateral tepals are the first organs to be initiated, followed shortly thereafter by the two median tepals. The two lateral stamens are initiated first, directly opposite the lateral tepals, and are followed by two median stamens initiated directly opposite the median tepals. A two-lobed stigma is clearly visible during the early stages of development of the gynoecium. On some of the young inflorescences, all floral parts were covered by extracellular calcium oxalate crystals. The release of these prismatic crystals occurs before the stamens and petals have reached maturity. The mode of floral development observed in Anthurium has similarities with that reported for Gymnostachys . However, contrary to Gymnostachys, the development of the flower of A. jenmanii is not unidirectional.

Effect of prothrombin and its activation fragments on calcium oxalate crystal growth and aggregation in undiluted human urine in vitro: relationship between protein structure and inhibitory activity

2002 ◽  
Vol 102 (4) ◽  
pp. 425-434 ◽  
Author(s):  
Phulwinder K. GROVER ◽  
Rosemary L. RYALL
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Human Urine ◽  
Inhibitory Activity ◽  
Coulter Counter ◽  
Crystal Aggregation ◽  
Activation Peptides ◽  
Scanning Electron

In recent years there has been great interest in the putative role of prothrombin and its activation peptides, especially the urinary form of prothrombin fragment 1, in the pathogenesis of calcium oxalate (CaOx) urolithiasis. Previously, we showed that prothrombin and its activation peptides inhibit CaOx crystallization in inorganic conditions in vitro. The aim of the present study was to determine if this inhibitory activity is retained in undiluted human urine and, therefore, whether it is likely to have any influence under physiological conditions. A secondary objective was to assess the relationship between the structures of the proteins and their inhibitory activities. Prothrombin was purified from Prothrombinex-HT, cleaved with thrombin and the resulting fragment 1 (F1) and fragment 2 (F2) were purified. The purity of each protein was confirmed by SDS/PAGE, and their effects on CaOx crystallization in undiluted ultrafiltered human urine were determined at a final concentration 80.65nmol/l using Coulter Counter and [14C]oxalate analysis. The precipitated crystals were visualized using scanning electron microscopy. The Coulter Counter data revealed that, whereas prothrombin and its activation peptides did not affect the urinary metastable limit and the size of the precipitated particles, F1 did significantly reduce the latter. These findings were corroborated with scanning electron microscopy which also revealed that the reduction in particle size caused by F1 resulted from a decrease in the degree of crystal aggregation, rather than in the size of the individual crystals. The [14C]oxalate data showed that none of the proteins added significantly inhibited the mineral deposition. It was concluded that with the exception of F1, which does inhibit CaOx crystal aggregation, prothrombin and its activation peptides do not alter the deposition and aggregation of CaOx crystals in ultrafiltered human urine in vitro. Also, the γ-carboxyglutamic acid domain of prothrombin and F1, which is absent from thrombin and F2, is the region of the molecules that determines their potent inhibitory effects. The superior potency of F1, compared with prothrombin, probably results from the molecule's greater charge-to-mass ratio.

scholarly journals Effect of Dolichos biflorus Seeds Based Functional Beverage on In Vitro Calcium Oxalate Crystallization in Human Urine

2021 ◽  
Vol 12 (5) ◽  
pp. 5836-5844
Keyword(s):  
Antioxidant Activity ◽  
Calcium Oxalate ◽  
Human Urine ◽  
Crystallization Process ◽  
Radical Scavenging ◽  
Scavenging Activity ◽  
Calcium Oxalate Crystals ◽  
Dolichos Biflorus ◽  
Oxalate Crystals

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.

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