Property changes of urinary nanocrystallites and urine of uric acid stone formers after taking potassium citrate

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.

High-throughput and rapid fluorescent visualization sensor of urinary citrate by CdTe quantum dots

In this paper, we have presented a novel CdTe quantum dots (QDs) based fluorescent sensor for visual and turn-on sensing of citrate in human urine samples. The europium ion (Eu(3+)) can lead to the fluorescence quenching of thioglycollic acid (TGA) modified CdTe QDs due to photoinduced electron transfer accompanied by the change of emission color from yellow to orange. Next, addition of citrate breaks the preformed assembly because citrate can replace the CdTe QDs, based on the fact that the Eu(3+) ion displays higher affinity with citrate than the CdTe QDs. Thus the photoinduced electron transfer is switched off, and the fluorescence emission of CdTe QDs is rapidly (within 5min) recovered, simultaneously, the orange emission color restores to yellow. Such proposed strategy may conveniently discriminate the patient of renal stone from normal person by naked eyes. In addition to visualization detection, the fluorescence responses can be used for well quantifying citrate in the range of 0.67-133μM. So, the present, simple, low-cost and visualized citrate fluorescence sensor has great potential in the applications for earlier screening in clinical detection.

Comparative Analysis of Compositions between Calcium Phosphate Calculi and Urinary Crystallites in the Stone-Formers

The chemical composition of urinary crystallites of less than 1000 nm from 10 calcium phosphate (CaP) stone-formers were investigated and compared with that from healthy subjects using X-ray power diffraction, Fourier transform infrared spectroscopy and nanoparticle size analyzer. Although there were some calcium oxalate monohydrate (COM) crystals in CaP stones, the main components of crystallites in urine of CaP stone formers were uric acid (UA), CaP and COM, while that in healthy urine was mainly UA and a small amount of COM. That is, the CaP content in urinary crystallites of CaP stone-formers was significantly higher than that of controls. The particle size range of crystallites in lithogenic urine was 3~1000 nm and most of these crystallites were aggregated, but it was 30~500 nm in healthy subjects.