Calcium oxalate crystal-containing

Bark contains 2-5% inorganic solids of the dry bark weight (determined as ash). The metals are present as various salts including oxalates, phosphates, silicates, etc. Some of them are bound to the carboxylic acid groups of the bark substance. Calcium and potassium are the predominating metals. Most of the calcium occurs as calcium oxalate crystals deposited in the axial parenchyma cells. Bark also contains trace elements, such as boron, copper, and manganese. 

Thompson, M.E., Lewin-Smith, R., Kalasinsky, V.F., Pizzolato, K.M., Fleetwood, M.L., McElhaney, M.R., Johnson, T.O. (2008). Characterization of melamine-containing and calcium oxalate crystals in three dogs with suspected pet food-induced nephrotoxicosis. Vet. Pathol. 45 417-26. 

Arranged horizontally or radially in the tree are the wood rays, which, as mentioned earlier, are composed predominantly of small, bricklike, and often living cells called parenchyma see Figures 4, 7, and 11). These cells function in radial translocation but have a major role as a storage receptacle, and frequently contain extraneous materials such as starch, fats, oils, various sugars, and inorganic depositions such as calcium oxalate crystals or silica (Figure 12). 

In some forms of steatorrhea, calcium, which normally binds to and precipitates oxalate in the intestine, binds instead to fatty acids producing increased oxalate absorption and hyperoxaluria. Even though urinary calcium is decreased under these conditions, the concentration of urinary oxalate may be elevated sufficiently to cause precipitation of calcium oxalate crystals. Stone formation can be exacerbated by a diet that contains foods rich in oxalate, such as rhubarb, citrus fruits, tea, and cola drinks. 

The above investigations built upon the pioneering studies of Haka et al. [45], by showing that excised calcifications were identifiable by Raman spectroscopy and separable into groups type I, containing calcium oxalate dihydrate (cod) and type II, containing calcium hydroxyapatite (hap). Calcium oxalate crystals are mainly found in benign ductal cysts, while calcium hydroxyapatite crystals... 

The last theory on stone formation comprises the matrix theory in which proteins may play an important role in urolithiasis (FI). This theory is based on analyses of many stones, which revealed that the core of these stones contained protein. It had been shown in vitro that certain proteins bind calcium and even induce the calcification process (Rl). These proteins, also called promoters, were therefore considered to be able to activate the initial crystallization process. However, these results could not be verified (FI). Recently it has been shown that in vitro calcium oxalate crystals do contain protein and that the crystallization in urine is not a random event, but rather a selective phenomenon (M4). This supports an earlier statement that stones contain about 1.6% of their weight in nondialyzable extractable protein and that the composition is the same for all stones, regardless of their mineral composition (S7). 

The elemental distribution of Ca, Si, and Mn in the hair of the common stinging nettle Urtica dioica) obtained using the Oxford University PIXE microprobe. The color code for Ca is yellow, >3.4 M orange, 2.0-3.4 M red, 1.5-2.0 M dark blue, 1-1.5 M blue, 0.5-1.0 M light blue, 0.1-0.5 M white, <0.1 M. The color codes of Si and Mn are similar. The PIXE data show that the tip mainly is made up of Si (presumably amorphous silica), but the region behind is largely made up of Ca (calcium oxalate crystals). The base of the hair contains substantial amounts of Mn. The pictures were kindly provided by R. J. P. Williams. 

Microscopically, the powder from the edge of the leaflets and the bracts is g onze-green rather than yellow-gyeen, and again lacks the characteristic odor of fresh powder. The microstructure appears normal, with double calcium oxalate crystals, and the various types of hairs—unicellular pointed, short cysto-lithic (containing calcium carbonate crystals), conical, swollen... 

B. Group 2a plants contain insoluble calcium oxalate crystals that may cause burning pain and swelling of mucous membranes. Many houseplants are commonly found in this category. 

C. Group 2b plants contain soluble oxalate salts (sodium or potassium) that can produce acute hypocalcemia, renal injury, and other organ damage secondary to precipitation of calcium oxalate crystals in various organs (see p 295). Mucous membrane irritation is rare, allowing patients to ingest sufficient quantities to cause systemic toxicity. Gastroenteritis may also occur. 

Jack-in-the-pulpit contains water-insoluble calcium oxalate crystals that are destroyed by processing (heating or drying)... 

Tannia leaves are nutritionally superior to the tubers with respect to protein, calcium, phosphorus, iron, vitamin A aid vitamin C. They are an excellent source of vitamin A. Hence, they compensate for most of the nutritional deficiencies of the tuber. However, the leaves may contain much higher levels of highly irritating calcium oxalate crystals than the tubers. Therefore, the leaves should not be consumed raw by people or livestock, unless it is certain that they contain little or no oxalates. The leaves may be rendered safe by boiling. 

Boiled taro tubers are sunilat in nutritional v e to other root and tuber vegetables 167% water, 124 kcal per 100 g, and 1.9% proteinl. The nuimional value oi taro tubers is siridar to that of potatoes, except that die tain is much lower in wtamin C, The leaves are more nuliili ous than the tubers. Neither the tools nor the leaves of taro should be consumed taw, because some varieties contain potenually harmful amounts of calcium oxalate crystals. 

These solid phases are connected to the components in Fig. 4, with which they are in reversible equilibrium. For example, if magnesium ion were added to a complex solution containing solid calcium oxalate monohydrate (COM), the magnesium would compete with calcium for an increased share of the oxalate this would reduce the amount of the calcium oxalate complex, and finally a small amount of calcium oxalate sohd would dissolve to restore the complex concentration to its equilibrium value. In urine, this picture must be extended to account for the molecular substances that coat crystals and reduce access of the solution to the surface coated crystals do not redissolve readily. 

A saturated solution contains the maximum amount of a solute, as defined by its solubility. No more solute will dissolve in a solution saturated with that solute. If the solution is not saturated, more solute will dissolve in that solution. Sometimes, a solution will become supersaturated with a solute. A supersaturated solution contains more solute than allowed by the solubility of the solute. This is not a stable system, because there is more solute dissolved in the sample than the solvent can accommodate. In this case, the excess solute will come out of solution crystallizing as a solid, separating as a liquid, or bubbling out as a gas. For example, when blood or urine in the kidneys becomes supersaturated with calcium oxalate or calcium phosphate, a kidney stone can form. If the solute is a gas in liquid solvent, you would see bubbles forming in the solution. Perhaps you ve seen this phenomenon when you open a bottle of beer or soda pop. 

Renal parenchymal calcium deposition can be associated with significant renal dysfunction. When calcium deposits are encountered on renal biopsy, the calcium salt typically contains either phosphate or oxalate. The two anions are easily differentiated pathologically, as calcium oxalate is identified as refractile crystals under polarized light. In contrast, calcium phosphate is non-polarizable but gives a positive histochemical reaction to the von Kossa stain [16]. 

The high prevalence of oxalate containing renal (tubular) and urinary tract calcifications is related to the low solubility of the oxalate-calcium salt. High urine oxalate excretion increases urine calcium oxalate supersaturation and, therefore the risk of crystal formation in tubular fluid and urine. In human urine, calcium concentration is about ten fold higher than oxalate on molar base. Relatively modest increases in urine oxalate excretion will have significant effects on urine supersaturation [49], especially in patients with hypercalciuria where calcium is even in greater excess of oxalate. Nevertheless, most people do not suffer from renal calcifications [50-54], suggesting that renal protection mechanisms exist. 

Small crystals of calcium oxalate are a normal component of the urine. They form in the glomerular filtrate as water is reabsorbed and the urine is concentrated. The urine of most persons contains compoimds that inhibit the growth of crystals. These inhibitors include magnesium, citrate, pyrophosphate, and mucopolysaccharides. Apparently, persons who tend to form renal and bladder stones have reduced levels of these inhibitors. Stone formation has a genetic component. The disease may "run in the family."... 

In radial longitudinal section a lengthwise view of the tissues will be seen. The meduUary rays appear 15 to 25 cells in height and crossing at right angles to the other elements. The crystal fibers here will be seen to be composed of vertical rows of superimposed thin-walled cells each of which contains a monoclinic prism of calcium oxalate. The bast fibers appear elongated and taper ended and are associated with crystal fibers. 

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