US EPA

8437561 

Journal Article 

Calcium carbonates in gallstones 

Mashina, EV; Makeev, BA; Filippov, VN 

2015 

326 

1 

34-39 

Russian 

Relevance of the research. calcium carbonate, in the form of its three polymorphs: calcite, aragonite and vaterite, is included, beside natural systems, in composition of pathogenic biomineral aggregates, such as gallstones. The solution of the problem with calcium car- bonate genesis in gallstones is not only of medical practical value, but it is also of a great interest from the point of view of mineralogi- cal study. The study of morphological features, possible isomorphism, formation conditions of calcium carbonate in gallstones will allow comparing it with mineral analogues in natural objects, and thus, outlining the pattern of biomineral genesis. The aim of research is to study the distribution, the features of chemical composition and morphology of calcium carbonate in the gall- stones of inhabitants of Komi Republic. Methods of research: X-Ray structural analysis (Shimadzu XRD-6000), electron microscope JSM 6400 with energy-dispersive spectro- meter Link. Results. The study of 50 gallstones samples by X-ray structural analysis showed that 39 samples contained calcium carbonate of various modifications. Vaterite was detected in 74 % of the analyzed carbonate-containing gallstones and in 38 % of samples vaterite was as the only polymorph. Simultaneously three polymorphs of calcium carbonate were determined only in 10 %. The REM study of morpho- logical features of calcium carbonate showed that the carbonates were visualized as lamellar crystals, rhombohedrical, conical, dump- bell and irregular grains. The carbonates under study contain the admixtures: magnesium, manganese, iron and silicon, which content is less than 2 wt. %. Conclusions. It was determined that vaterite is the dominant polymorph carbonate calcium in the studied gallstones. 

Admixtures; Calcium carbonate; Gallstones; Genesis; Morphology; Polymorphic modifications