Peptidome profiles in melamine diet-induced bladder stones in C57BL/6 mice.

The aim of this research was to detect potential serum biomarkers of melamine diet-induced bladder stones in C57BL/6 mice. Magnetic bead-based weak cationexchange chromatography (MB-WCX) and matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) were employed to detect serum biomarkers in 10 mice fed a melamine diet and 10 control mice. Seventeen peaks (fold change>1.5) with a mass to charge (m/z) value of 1000-10,000 Da were detected in the two groups. Among the significant peaks, five were upregulated and the other 12 were downregulated in the model group. Among the upregulated peaks, 2954.49 and 1710.49 were found to correspond to the peptide regions of NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 8(Ndufα8) and basigin, respectively, by liquid chromatography with electrospray ionization and tandem triple quadrupole mass spectrometry(LC-ESI-MS/MS). Western blot analysis was used to detect the expression of Ndufα8 and basigin in another 10 model mice and 10 control mice. The western blot results confirmed the LC-ESI-MS/MS data. The expression of serum basigin and Ndufα8 was partly dependent the concentration of melamine, but no time dependence. In conclusion, Ndufα8 and basigin may be potential serum biomarkers for the detection of melamine diet-induced bladder stones in C57BL/6 mice.

Relationships between some lithogenetic factors and vitamin B6-status in idiopathic calcium lithiasis.

Several researchers have shown that a reduced intake of vitamin B6 can induce increased oxalate urinary excretion leading to a higher incidence of calcium oxalate stones. Furthermore, the treatment with pyridoxine in patients with urinary stones and high oxalate excretion has led to contradictory results as the excretion of oxalate was either decreased, unchanged or increased. To verify if these divergent results were linked to a different B6 status of the patients undergoing the treatment, we studied the vitamin B6 and the main lithogenetic factor levels in patients with idiopathic calcium lithiasis as compared to normal subjects. The results showed that a high oxalate excretion is not necessarily coupled with a low vitamin B6 status and viceversa. However, some stone formers present a non homogeneous vitamin pattern that could be the consequence of an abnormal vitamin B6 metabolism.

Studies on serum mucoproteins in patients with urinary calculi.

A significant increase in serum mucoproteins in stone patients has been observed previously. The present study describes the variation of the constituents of mucoproteins obtained on hydrolysis. The serum mucoproteins of 31 patients with urinary calculi (13 with kidney stone, 7 with bladder stone and 11 with stones in other sites) were analysed and compared with that of 15 healthy control subjects, who had no personal or family history of calculi. The mucoproteins, glycosylated serum proteins, hexosamine and sialic acid were increased in all patients irrespective of the site of stone, while uronic acid decreased as compared with the control subjects. Serum fucose increased in all patients except in kidney stone formers. Uronic acid decreased in all stone formers irrespective of the site of the stone. It is suggested that a different type of mucoprotein is present in such patients.