title: Quantification of crystal growth of calcium oxalate in gel and its modification by urinary constituents in a new flow model of crystallization.
abstract: OBJECTIVE
  To use a new flow model of crystallization to quantify the growth of calcium oxalate monohydrate (COM) in a gel matrix under simulated physiological conditions.
  
  
  METHODS
  Artificial urine supersaturated in COM was conducted through channels containing a gel with COM seed crystals (flow rate: 0.5 ml. per minute; reaction time: 4 hours; 37 +/- 1C). A relative crystal growth parameter, Vcr, was quantified by discontinuous measurement of scattered light intensity by microphotometry. The effects on Vcr of varying a series of urinary parameters were investigated within the system.
  
  
  RESULTS
  The following order of effectiveness in changing COM growth could be derived: dilution > oxalate > calcium > magnesium approximately citrate.
  
  
  CONCLUSIONS
  Drinking therapy and lowering of urinary oxalate excretion can be concluded to be the most promising means of preventing CaOx urolithiasis. The new crystallization model demonstrated here should be suitable to new applications in the investigation of urinary stone formation.
authors.affiliation: Universitätsklinikum Marburg, Urologische Klinik, Marburg/Lahn, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Achilles
authors.forename: R
authors.initials: R
authors.lastname: Freitag
authors.forename: B
authors.initials: B
authors.lastname: Kiss
authors.forename: H
authors.initials: H
authors.lastname: Riedmiller
mesh_terms: D002129:Calcium Oxalate / Q000737:chemistry*; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D003460:Crystallization; D005782:Gels; D007700:Kinetics; D008956:Models, Chemical; D014545:Urinary Calculi / Q000737:chemistry
chemical_list: D005782:Gels; D002129:Calcium Oxalate