Biocolloids of Urine in Health and in Calculous Disease. Iii. The Mucoprotein Matrix of Urinary Calculi 1

Over a period of three years 676 renal or ureteral calculi have been decalcified by chelating agents.The matrix has been recovered by ultrafiltration through collodion membranes and sub- jected to analysis by a variety of techniques.The present report is concerned with the microscopic structure and the histochemical properties of the matrix recovered from calcigerous stones. MATERIAL AND METHODSPreparationt of matrix for histochemical studies.The decalcifying solution contained 5 per cent (wt/v) tetra- sodium ethylenediaminetetraacetate and 10 per cent (v/v) formalin adjusted to pH 7.8 ± 0.1 with 12 N HCI.Sixty-four calcigerous stones of wet weight 60 mg. to 28.35 gm., when surgically removed from the renal pelvis or ureter, were immediately rinsed in water and bisected with a hacksaw.The two halves were placed in a stop- pered Erlenmeyer flask containing 500 ml. of decalcifying solution.The filings from the sawcut were subj ected to chemical (1) and spectroscopic (2) analyses.The flasks containing the halved calculi were carefully stored at 3°C. and every effort was made to prevent agi- tation of the solution.At 7 to 10-day intervals the de- calcifying solution was removed by pipette and filtered through collodion membranes of 0.01 micron in pore size.3Refiltration through membranes of average pore diameter less than 0.005 micron did not result in recovery of additional material.The decalcifying solu- tion was carefully replaced and the process continued for 3 to 27 weeks, depending upon the size of the stone and the rate of decalcification.The residual matrix invari- ably formed a complete cast of the original stone, and decalcification of a degree permitting sectioning with the 1 This investigation was supported by research grants