THE URIC-ACID WHEWELLITE ASSOCIATION IN HUMAN-KIDNEY STONES

Abstract

Human kidney stones, composed almost exclusively of uric acid and whewellite, were studied using X-ray (powder and single-crystal) as well as scanning electron-diffraction techniques. Whewellite, showing as a concentric aggregate characteristically marked by radial striations, is enclosed within a mass of uric acid, the crystallites of which grow with their b axis parallel to the radial direction of the striations. That axis corresponds to b (2 .times. 7.294 .ANG.) and tends to systematically superimpose over its uric acid counterpart (b = 7.40 .ANG.). Nonetheless no other such dimensional match was found for the other set of periodicities that characterize the uric acid whewellite interfaces, raising questions that a systematic epitaxial interaction could there take place. Selected uric acid-whewellite contacts and the crucial role of the "matrix" were also investigated.