Gallstones calcium

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]. 

Biliary sludge A deposit of tiny stones or crystals made up of cholesterol, calcium bilirubinate, and other calcium salts. The cholesterol and calcium bilirubinate crystals in biliary sludge can lead to gallstone formation. 

Calcium oxalate (whewellite, weddelite) Gallstones plant defenses... 

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. 

Part of the cholesterol newly synthesized in the liver is excreted into bile in a free non-esterified state (in constant, amount). Cholesteiol in bile is normally complexed with bile salts to form soluble cholic acids, Free cholesterol is not readily soluble and with bile stasis or decreased bile salt concentration may precipitate as gallstones. Most common gallstones are built of alternating layers of cholesterol and calcium bilirubin and consist mainly (80-90%) of cholesterol. Normally. 80% of hepatic cholesterol arising from blood or lymph is metabolized to cholic acids and is eventually excreted into the bile in the form of bile salts. 

Gallstones are solid formations in the gallbladder that are composed of cholesterol and bile salts. Although they vary in chemical composition, they generally contain a mixture of cholesterol, bilirubin, calcium, and mucoproteins, In the United States, 70% to 85% of all gallstones are predominantly cholesterol and more than 10% of the adult population is affected. 

Systemic complications of Crohn s disease are common, and similar to those found with ulcerative colitis. Arthritis, iritis, skin lesions, and liver disease often accompany Crohn s disease. Renal stones occur in up to 10% of patients with Crohn s disease (less frequently with ulcerative colitis) and are caused by fat malabsorption, which allows for greater oxalate absorption and formation of calcium oxalate stones. Gallstones also occur with greater frequency in patients with ileitis, possibly because of bile acid malabsorption at the terminal ileum. 

Components of gallstones Cholesterol, calcium bilirubinate, and bile... 

Edwards et al. (1958) have used infrared spectroscopy in the qualitative analysis of 30 specimens of human biliary calculi. The spectra of cholesterol, calcium bilirubinate, and calcium carbonate display prominent and characteristic bands that do not overlap in certain areas of the spectrum. Bands at 3380, 2910, and 1055cm" indicate the presence of cholesterol, a doublet at 1670 and 1630 cm" is characteristic of calcium bilirubinate, and a sharp band at 875 cm is produced by calcium carbonate. It is thus possible to verify the principal constituents of biliary calculi—whether they are (1) pure gallstones that are composed of either cholesterol, calcium bilirubinate, or calcium carbonate, or are (2) mixed gallstones that are composed chiefly of two or three of these components, or are (3) combined llstones with a nucleus of one kind and a shell of another substance. 

Recent advances in infrared spectroscopy have allowed rapid and simple determination of some gallstone ingredients (Chihara et al., 1958) with a minimum quantity of specimen. Of various absorptions characteristic of calcium bilirubinate, the one at 1624 cm , which is due to Vc c of pyrrole nuclei (Suzuki and Toyoda, 1966), was chosen as the key band for quantitative analysis. In analyses of 10 gallstone specimens (Toyoda, 1966) the infrared-determined calcium bilirubinate content was found to lie in between values from two kinds of chemical data those obtained for extracts of the stones with (a) chloroform after HCl treatment, plus a 5 % ammonia extraction, and (b) those obtained for extracts with chloroform, but no ammonia extraction. Toyoda claims that the infrared data show satisfactory proportionality with both types of data. 

Calcium has been recognized as a constituent of gallstones since the earliest chemical studies (see reference 118). It occurs as calcium carbonate (either calcite or aragonite), calcium phosphate (apatite), calcium bilirubinate, or the salts of bile acids and fatty acids. In normal hepatic bile, the calcium concentration is about 21 mg %. It is about 45 mg % in normal gallbladder bile and about twice that in the gallbladder bile of patients with cholesterol stones (119). The concentration of calcium is said to vary with the concentration of bile salts (3). Apparently, calcium in bile is bound in part to bile salt micelles, and under normal conditions this complex remains stable and soluble (120). However, under appropriate conditions of pH, calcium concentration, and anion concentration, calcium salts may precipitate. 

Okey (127) produced gallstones rich in calcium phosphate, although... 

These results raise the question of whether these amorphous stones containing calcium bile salts could be related to the pathogenesis of the cholesterol stones. Glycine-conjugated bile salts, particularly of the less soluble compounds such as chenodeoxycholate and lithocholate, have been found in greater proportions in the centers of human gallstones (167), and it would be of interest to know whether this is the case in the cholesterol stones that frequently coexisted in these animals. 

Fujimaka (158), in the course of experiments on vitamin-deficient diets, noted that rats kept for 22-37 weeks on a vitamin A deficient diet developed urinary calculi and, later, gallstones in the common duct. When calcium and phosphorus in the diet were also restricted, gallstones formed in 6-8 weeks. The gallstones were said to contain calcium salts, cholesterol, and pigment the methods used for these determinations were not described. 

Usuki (169) raised rabbits on a diet deficient in fat-soluble vitamins and found a 9% incidence of gallstones after 6-8 weeks. Qualitative analysis revealed that these small sandlike stones contained calcium, bilirubin, and traces of cholesterol. 

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