Component analyses of urinary nanocrystallites of uric acid stone formers by combination of high-resolution transmission electron microscopy, fast Fourier transformation, energy dispersive X-ray spectroscopy, X-ray diffraction and Fourier transform infrared spectroscopy.

This study aimed to analyse the components of nanocrystallites in urines of patients with uric acid (UA) stones. X-ray diffraction (XRD), Fourier transform infrared spectroscopy, high-resolution transmission electron microscopy (HRTEM), fast Fourier transformation (FFT) of HRTEM, and energy dispersive X-ray spectroscopy (EDS) were performed to analyse the components of these nanocrystallites. XRD and FFT showed that the main component of urinary nanocrystallites was UA, which contains a small amount of calcium oxalate monohydrate and phosphates. EDS showed the characteristic absorption peaks of C, O, Ca and P. The formation of UA stones was closely related to a large number of UA nanocrystallites in urine. A combination of HRTEM, FFT, EDS and XRD analyses could be performed accurately to analyse the components of urinary nanocrystallites.

Changes in urinary nanocrystallites in calcium oxalate stone formers before and after potassium citrate intake.

The property changes of urinary nanocrystallites in 13 patients with calcium oxalate (CaOx) stones were studied before and after ingestion of potassium citrate (K3cit), a therapeutic drug for stones. The analytical techniques included nanoparticle size analysis, transmission electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The studied properties included the components, morphologies, zeta potentials, particle size distributions, light intensity autocorrelation curves, and polydispersity indices (PDIs) of the nanocrystallites. The main components of the urinary nanocrystallites before K3cit intake included uric acid, ß-calcium phosphate, and calcium oxalate monohydrate. After K3cit intake, the quantities, species, and percentages of aggregated crystals decreased, whereas the percentages of monosodium urate and calcium oxalate dehydrate increased, and some crystallites became blunt. Moreover, the urinary pH increased from 5.96 ± 0.43 to 6.46 ± 0.50, the crystallite size decreased from 524 ± 320 nm to 354 ± 173 nm, and the zeta potential decreased from -4.85 ± 2.87 mV to -8.77 ± 3.03 mV. The autocorrelation curves became smooth, the decay time decreased from 11.4 ± 3.2 ms to 4.3 ± 1.7 ms, and the PDI decreased from 0.67 ± 0.14 to 0.53 ± 0.19. These changes helped inhibit CaOx calculus formation.

[The property changes of urine crystallites of calcium oxalate stone formers before and after taking medicine].

The property changes of urine crystallites of six cases of calcium oxalate stone formers before and after taking medicine were comparatively studied using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, nanoparticle size analyzer, and transmission electron microscopy (TEM). The results showed that the urinary pH increases after taking medicine (before taking 5.87 +/- 0.51, after taking 6.23 +/- 0.74.) Before taking medicine the main components of urine crystallites were uric acid, calcium oxalate monohydrate (COM) and biphosphate. The types and quantities of urine crystallites after taking medicine were less than that of before. The average size of urine crystallite before taking medicine was (579 +/- 326) nm, and it reduced to (404 +/- 338) nm after taking medicine. After taking medicine the zeta potential was also decreased to (-7.29 +/- 4.16) mV from (-4.28 +/- 2.55) mV. The decrease in zeta potential is beneficial to preventing urinary crystallites deposition. The edges and corners of urine crystallite were sharp with significant aggregation before taking medicine, while they became blunt and less aggregation after taking medicine. The analysis of the property changes of urine crystallites of calcium oxalate stone patients before and after taking medicine by using modern equipments has important clinical significance to the clinical prevention and treatment of urinary stones.