[Presence and role of trace elements in urinary calculi]. / Nature et rôle des éléments traces dans les calculs urinaires.

AIM: To assess the possible nature and role of trace elements in the pathogenesis of urinary stones. MATERIAL AND METHOD: A series of 76 calculi from the East-Algerian region has been investigated through Fourier transform infrared spectroscopy for chemical analysis and X-ray fluorescence for detecting trace elements. RESULTS: Among the detected trace elements, Zn, Sr, Pb, Cu, Rb and Se, only the first three had significant values. Overall, the calcium components, namely calcium oxalate and calcium phosphate, were the most loaded by these elements contrary to organic components such as uric acid and cystine, which had low contents. CONCLUSION: The correlation of contents of Zn and Sr with the stone components (carbapatite, weddellite and whewellite) suggests an adsorption of these trace elements in the case of calcium stones rather than a catalytic process. LEVEL OF EVIDENCE: 3.

[Revisiting the chemical diversity in prostatic calculi: a SEM and FT-IR investigation]. / Diversité chimique des calculs prostatiques : une investigation par MEB et spectroscopie infrarouge.

OBJECTIVE: Revisiting the chemical diversity of the crystalline phases of prostatic calculi by means of SEM and FT-IR analysis. METHODS: A set of 32 prostatic calculi has been studied by FT-IR and SEM. RESULTS: FT-IR analysis has determined the chemical composition of each prostatic calculus and the SEM observation has described the morphology of the calculi surfaces and layers. Infrared analysis revealed that 90.7% of the stones were mainly composed of calcium phosphates. However, several mineral phases previously not reported in prostatic calculi were observed, as brushite or octocalcium phosphate pentahydrate. CONCLUSION: Prostatic calculi exhibited a diversity of crystalline composition and morphology. As previously reported for urinary calculi, relationships between composition and morphology of prostatic stones and étiopathogenic conditions could be of interest in clinical practice.

[Synchrotron radiation techniques for structural characterisation of biological entities: an example with renal stone analysis]. / Les techniques de rayonnement synchrotron au service de la caractérisation d'objets biologiques: un exemple d'application, les calculs rénaux.

This paper describes the opportunities given by the synchrotron radiation techniques regarding the structural characterisation of biological entities. After a short recall on the characteristics of the synchrotron radiation, are described the experimental devices based on fluorescence X, wide angle X-ray scattering and X-ray absorption spectroscopy, which may applied for biological samples, especially in the field of stone analysis. Recent progresses in medical research using synchrotron radiation will be also discussed.