Calcium oxalate kidney stones

Whether this increased oxalate excretion has consequences in terms of stone formation depends very much on the dosage and duration of treatment. In a small study in healthy individuals short-term, high-dose ascorbic acid (4 g in 5 days) did not affect the risk factors associated with calcium oxalate kidney stone formation (8). A prospective study of the association between doses of pyri-doxine and ascorbic acid and the risk of symptomatic kidney stones was undertaken in a large cohort of US nurses. Ascorbic acid was not associated with a higher risk of stone formation (25). 

Auer BL, Auer D, Rodgers AL. The effect of ascorbic acid ingestion on the biochemical and physicochemical risk factors associated with calcium oxalate kidney stone formation. Clin Chem Lab Med 1998 36(3) 143-7. 

McHarg T, Rodgers A, Charlton K. Influence of cranberry juice on the urinary risk factors for calcium oxalate kidney stone formation. BJU Int 2003 92(7) 765-8. 

Magnesium deficiency is common in SBS patients with large ostomy or diarrheal losses. This deficiency should be corrected aggressively because of the correlation between low magnesium and potassium concentrations, and magnesium supplementation decreases the formation of calcium oxalate kidney stones. Serum concentrations are most commonly monitored, but urinary magnesium concentrations may decrease earlier with deficiency, and may be a better estimate of total body stores than serum levels. Oral supplementation may be difficult because it can contribute to increased diarrhea or ostomy output. However, repletion is necessary to correct potassium deficits in addition to magnesium losses. ... 

Massey, L.K., H. Roman-Smith, and R.A. Sutton. 1993. Effect of dietary oxalate and calcium on urinary oxalate and risk of formation of calcium oxalate kidney stones. /. Am. Diet. Assoc. 93(8) 901-906. 

Along which lines of reasoning shall we proceed Because patients with hyperuricemia and hyperuricosuria are more frequently inclined to get uric acid- and calcium oxalate kidney stones than patients with normal uric acid levels, the prophylaxis of recurrent stones can result from a decrease in serum concentrations of uric acid as well as the excretion of uric acid in the urine. 

Calcium oxalate kidney stones L-glyceric aciduria... 

Resnick, M., Pridgen, D.B., and Goodman, H.O. Calcium oxalate kidney stones genetic predisposition to formation of calcium oxalate renal calculi. N. Engl. J. Med. 278, 1313-1318 (1968)... 

Lemann, J., Piering, W.F. and E.J. Lennon Possible role of carbohydrate induced calciuria in calcium oxalate kidney stone formation N.Bngl J.Med. 280, 232, 19 9. 

To understand such phenomena quantitatively, you must be able to solve problems in solubility equilibria. Calcium oxalate kidney stones form when the concentrations of calcium ion and oxalate ion are sufficiently great. What is the relationship between the concentrations of ions and the solubility of a salt What is the minimum concentration of oxalate ion that gives a precipitate of the calcium salt from a 0.0025 M solution of Ca (the approximate concentration of calcium ion in blood plasma) What is the effect of pH on the solubility of this salt We will look at questions such as these in this chapter. 

Stone analysis showed only magnesium ammonium phosphate and no xanthine was present. R.J. (III5) had renal colic and a stone by x-ray but no stone was recovered and C.J. (III3) had a calcium oxalate kidney stone. 

The toxicity of vitamin C is very low and doses of 10 g/day appear to be quite safe. The major concern at high doses is the risk of the formation of calcium oxalate kidney stones and it might be wise not to take calcium supplements with vitamin C. The increase of oxalate levels, even at high doses, only increases by about 50%. The evidence for rebound effects where, following withdrawal of high-dose therapy, vitamin C levels fall and for in vivo mutagenicity is not conclusive. The worst effects of vitamin C at high dose appear to be GI disturbances and diarrhoea. 

Nephrocalcin in the kidneys has considerable homology with matrix Gla protein. It is probably involved in renal reabsorption of calcium, but also acts to solubilize calcium salts in the urine. It is found in calcium oxalate renal stones. 

Calcium and oxalate arc closely associated with the fomiation of stones in the urinary tract. Kidney stones (renal calculi) and bladder stones are mineral deposits containing protein. They can have a diameter of a centimeter or greater. Most kidney stones (75%) are composed mainly of calcium oxalate or calcium oxalate with hydroxyapatite. Uric acid stones account for about 10% of stones xanthine stones are rare. Calcium containing kidney stones occur in fetem nations and affect about one person in 1000. The disease may occur in children, but typically occurs after rhe age of 30 and in men, Calcium biadder stones occur malniy in the children of underdeveloped countries, such as Thailand, and occur rarely in West em nations. Some kidney stones do not result in symptoms. Others may cause blood loss in the urine. Stones that obstruct the flow of urine from the kidney into the ureter result in violent pain, nausea, and vomiting. 

OxaKc add HOOC-COOH. O.a. occurs widely in plants as its caldum, magnesium and potassium salts. By forming insoluble calcium salts in the intestine, it hinders the absorption of caldum. It is not metabolized by animals, and in large quantities it is poisonous. Humans normally excrete 10-30mg O.a. daily higher levels may lead to kidney damage (formation of oxalate kidney stones). 

Two nucleation processes important to many people (including some surface scientists ) occur in the formation of gallstones in human bile and kidney stones in urine. Cholesterol crystallization in bile causes the formation of gallstones. Cryotransmission microscopy (Chapter VIII) studies of human bile reveal vesicles, micelles, and potential early crystallites indicating that the cholesterol crystallization in bile is not cooperative and the true nucleation time may be much shorter than that found by standard clinical analysis by light microscopy [75]. Kidney stones often form from crystals of calcium oxalates in urine. Inhibitors can prevent nucleation and influence the solid phase and intercrystallite interactions [76, 77]. Citrate, for example, is an important physiological inhibitor to the formation of calcium renal stones. Electrokinetic studies (see Section V-6) have shown the effect of various inhibitors on the surface potential and colloidal stability of micrometer-sized dispersions of calcium oxalate crystals formed in synthetic urine [78, 79]. 

The presence of sparingly soluble components in human urine, such as calcium oxalate, calcium phosphate, magnesium ammonium phosphate, uric acid and l-cystine. Kidney stones are composed mainly of these compounds. 

Bone, shell, and coral are not, however, the only biominerals created by living organisms. The kidney and liver of animals, for example, often synthesize biominerals in the form of pathological stones (known as calculi) of varied composition (mostly of calcium oxalate, calcium phosphate, or... 

Calcium oxalate monohydrate responsible for the formation of most kidney stones significantly increased mitochondrial superoxide production in renal epithelial cells [42], Recombinant human interleukin IL-(3 induced oxygen radical generation in alveolar epithelial cells, which was suppressed by mitochondrial inhibitors 4 -hydroxy-3 -methoxyacetophe-none and diphenylene iodonium [43]. Espositio et al. [44] found that mitochondrial oxygen radical formation depended on the expression of adenine nucleotide translocator Anti. Correspondingly, mitochondria from skeletal muscle, heart, and brain from the Antl-deficient mice sharply increased the production of hydrogen peroxide. 

If the kidneys remove too many calcium ions from the blood, the equilibrium position in the kidneys shifts to the right. Solid calcium phosphate can form in the kidneys, producing kidney stones. Kidney stones, which are painful, can also form as the result of calcium oxalate precipitating in the kidneys. Precipitates of other compounds can affect different areas of the body gallstones in the gall bladder and gout in the joints are two examples. 

A patient s kidney stones are composed primarily of calcium oxalate, CaC204. The patient s physician prescribes a medicine that is basic, and advises the patient to drink plenty of water. Explain why this is a suitable treatment. 

Oxalic acid occurs in high concentrations in pineapple and rhubarb, among other plants, and is responsible for the sharpness of the fresh fruits. Ingestion of too much oxalic acid can cause gastroenteritis, commonly recognized as a stomach ache. A salt of oxalic acid, calcium oxalate, is the stuff of kidney stones. 

When particles or large molecules make contact with water or an aqueous solution, the polarity of the solvent promotes the formation of an electrically charged interface. The accumulation of charge can result from at least three mechanisms (a) ionization of acid and/or base groups on the particle s surface (b) the adsorption of anions, cations, ampholytes, and/or protons and (c) dissolution of ion-pairs that are discrete subunits of the crystalline particle, such as calcium-oxalate and calcium-phosphate complexes that are building blocks of kidney stone and bone crystal, respectively. The electric charging of the surface also influences how other solutes, ions, and water molecules are attracted to that surface. These interactions and the random thermal motion of ionic and polar solvent molecules establishes a diffuse part of what is termed the electric double layer, with the surface being the other part of this double layer. 

Mechanism of Action A nonabsorbable compound that alters urinary composition of calcium, magnesium, phosphate, and oxalate. Calcium binds to cellulose sodium phosphate, thus preventing intestinal absorption of it. Therapeutic Effect Prevents the formation of kidney stones. 

Another example of an undesirable precipitation reaction involves the formation of kidney stones in the human body. The major type of kidney stones consists of calcium in combination with oxalate ). The... 

This reaction shows calcium chloride reacting with oxalic acid to produce calcium oxalate and hydrochloric acid. The calcium oxalate is the kidney stone. Calcium oxalate precipitates out of the urine in the kidneys of all individuals. Normally, the solids formed are grain size and do not cause prob-... 

Approximately two thirds of kidney stones contain Ca2+ phosphate or Ca2+ oxalate. Many patients with such stones exhibit a defect in proximal tubular Ca2+ reabsorption that causes hypercalciuria. This can be treated with thiazide diuretics, which enhance Ca2+ reabsorption in the distal convoluted tubule and thus reduce the urinary Ca2+ concentration. Salt intake must be reduced in this setting, since excess dietary NaCI will overwhelm the hypocalciuric effect of thiazides. Calcium stones may also be caused by increased intestinal absorption of Ca2+, or they may be idiopathic. In these situations, thiazides are also effective, but should be used as adjunctive therapy with other measures. 

TThe primary function of D-amino acid oxidase, present at high levels in the kidney, is thought to be the detoxification of ingested D-amino acids derived from bacterial cell walls and from cooked foodstuffs (heat causes some spontaneous racemization of the l-amino acids in proteins). Oxalate, whether obtained in foods or produced enzymatically in the kidneys, has medical significance. Crystals of calcium oxalate account for up to 75% of all kidney stones. ... 

The potassium or calcium salt form of oxalic add is distributed widely in the plant kingdom. Oxalic acid is found in spinach, rhubarb, etc. Oxalic acid is a product of metabolism of fungi or bacteria and also occurs in human and animal urine the calcium salt is a principal constituent of kidney stones. 

Most kidney stones consist of insoluble calcium salts, such as calcium oxalate. 

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. 

Disposition in the Body. Less than 5% of ingested oxalic acid is absorbed in healthy adults. About 8 to 40 mg of oxalic acid is normally excreted in the urine daily this is derived mainly from the metabolism of dietary ascorbic acid and glycine with small amounts from dietary oxalic acid and other minor metabolic sources. Calcium oxalate is a major constituent of kidney stones and is frequently found as crystals in freshly-voided urine. In normal subjects concentrations of oxalic acid in blood range from about 1 to 3 pg/ml. Small amounts of oxalate are produced as a metabolite of ethylene glycol. 

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