title: Calcium content of different compositions of gallstones and pathogenesis of calcium carbonate gallstones.
abstract: OBJECTIVE
  Our aim was to investigate the calcium content of different gallstone compositions and the pathogenic mechanisms of calcium carbonate gallstones.
  
  
  METHODS
  Between August 2001 and July 2007, gallstones from 481 patients, including 68 calcium carbonate gallstones, were analyzed for total calcium content. Gallbladder bile samples from 33 cases and six controls were analyzed for pH, carbonate anion level, free-ionized calcium concentration and saturation index for calcium carbonate.
  
  
  RESULTS
  Total calcium content averaged 75.6 %, 11.8 %, and 4.2 % for calcium carbonate, calcium bilirubinate and cholesterol gallstones. In 29.4 % of patients, chronic and/or intermittent cystic duct obstructions were caused by polypoid lesions in the neck region and 70.6 % were caused by stones. A total of 82 % of patients had chronic low-grade inflammation of the gallbladder wall and 18.0 % had acute inflammatory exacerbations. In the bile, we found the mean pH, mean carbonate anion, free-ionized calcium concentrations, and mean saturation index for calcium carbonate to be elevated in comparison to controls.
  
  
  CONCLUSIONS
  From our study, we found chronic and/or intermittent cystic duct obstructions and low-grade GB wall inflammation lead to GB epithelium hydrogen secretion dysfunction. Increased calcium ion efflux into the GB lumen combined with increased carbonate anion presence increases SI_CaCO(3) from 1 to 22.4. Thus, in an alkaline milieu with pH 7.8, calcium carbonate begins to aggregate and precipitate.
authors.affiliation: Division of General Surgery, Department of Surgery, Taichung Metroharbor Tung's Memorial Hospital, Wuchi Town, Taichung County, Taiwan, ROC.
authors.forename: Ji-Kuen
authors.initials: JK
authors.lastname: Yu
authors.forename: Huichin
authors.initials: H
authors.lastname: Pan
authors.forename: Shing-Moo
authors.initials: SM
authors.lastname: Huang
authors.forename: Nan-Lan
authors.initials: NL
authors.lastname: Huang
authors.forename: Chung-Chin
authors.initials: CC
authors.lastname: Yao
authors.forename: Kuang-Ming
authors.initials: KM
authors.lastname: Hsiao
authors.forename: Chew-Wun
authors.initials: CW
authors.lastname: Wu
mesh_terms: D000368:Aged; D000838:Anions; D001646:Bile / Q000737:chemistry; D002118:Calcium / Q000032:analysis*; D002119:Calcium Carbonate / Q000032:analysis*; D002254:Carbonates / Q000032:analysis; D002764:Cholecystitis / Q000503:physiopathology; D001651:Cholestasis, Extrahepatic / Q000150:complications; D003549:Cystic Duct; D005260:Female; D042882:Gallstones / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D013624:Taiwan
chemical_list: D000838:Anions; D002254:Carbonates; D002119:Calcium Carbonate; D002118:Calcium