Urological Research 

About: Urological Research is an academic journal. The journal publishes majorly in the area(s): Calcium oxalate & Nephrology. Over the lifetime, 3194 publications have been published receiving 55370 citations.

Changes in stone composition according to age and gender of patients: a multivariate epidemiological approach.

Abstract: Urinary stone incidence and composition have changed markedly over the past half-century in industrialized countries, in parallel with profound changes in living standards and dietary habits, with a dramatic increase in the incidence of calcium oxalate stones. However, studies evaluating the influence of age and gender on the distribution of the various types of urinary calculi are scarce. We report the results of a study based on 27,980 calculi (from 19,442 males and 8,538 females) analyzed by infrared spectroscopy between 1976 and 2001. The relationships between age and sex and stone composition were investigated using a multivariate approach, based on correspondence factor analysis (CFA). We found a male predominance for calcium oxalate and uric acid, a female preponderance for calcium phosphate and struvite stones, and an increasing prevalence of uric acid stones with age in both genders. CFA was able to reconstruct in blind the age curve from stone composition. The first two axes of the multidimensional classification, which correspond to age, included 86.9% of the total variance, indicating that age was the main factor involved in stone type. Superimposition of age classes and stone components showed a strong relationship between age and whewellite, weddellite, brushite, carbapatite, octacalcium phosphate and uric acid, while other substances (whitlockite, amorphous carbonated calcium phosphate, struvite, proteins, mucopolysaccharides, triglycerides or ammonium urate) appeared weakly related to age. In addition, CFA suggests the role of common lithogenic factors between weddellite, carbapatite and brushite, which clustered in the same area, whereas the various crystalline forms of phosphate stones segregated into two different clusters, suggesting distinct pathogenic factors. In conclusion, this study provides a picture of the present epidemiology of urinary stones in France. CFA helped to confirm: (1) an etiopathogenic distinction between weddellite and whewellite, (2) etiopathogenic associations between chemical compounds, which were only suspected on a clinical basis, and (3) suggested yet unrecognized associations, especially with respect to the heterogeneous group of phosphate stones.

Evidence suggesting that high intake of fluoride provokes nephrolithiasis in tribal populations

Abstract: The present study was designed to evaluate the role of fluoride in urolithiasis in humans. Two areas were selected for this purpose, a fluoride endemic area (EA) and a fluoride non-endemic area (NEA). The prevalence of uroliathiasis was 4.6 times higher in EA than in NEA. Furthermore, the prevalence was almost double in subjects with fluorosis than without fluorosis in the endemic area. No relationship was observed between urolithiasis and the duration of fluorosis. The fluoride levels in drinking water ranged from 3.5 to 4.9 ppm in EA and subjects from this area excreted more fluoride. A comparison of normal subjects (NS) from EA and NEA revealed that endemic subjects tend to have slightly higher mean serum thiobarbituric acid reactive substance (TBAR) levels and excrete more oxalate and fluoride than their non-endemic counterparts. The urinary stone formers (SF) from the two areas showed a similar tendency, though again the difference was not significant. Citrate excretion in SF was almost normal in the EA, but NEA SF had significantly lower excretion levels. Urinary stones from endemic patients had higher fluoride, oxalate and calcium levels than those from non-endemic patients. In vitro studies suggested that fluoride did not influence the heterogonous mineralization of calcium oxalate. In conclusion, the data suggest that fluoride in vivo may behave as a mild promoter of urinary stone formation by (a) excretion of insoluble calcium fluoride, (b) increasing oxalate excretion and (c) mildly increasing the oxidative burden.

Sex- and age-related composition of 10 617 calculi analyzed by infrared spectroscopy.

Abstract: A series of 10 617 calculi were analyzed by stereomicroscopy and infrared spectroscopy. This first study of French calculi was compared with large series in the literature. That the frequency of pure calculi was the lowest ever observed can be related to the methodology routinely used in our laboratory, which includes microsampling. We described more than 70 components among the 10 617 calculi. The overall sex ratio male to female patients was high (2.27) and increased over the period 1981-1993. Calcium oxalate was the most frequent component (86.48%), followed by calcium phosphate (79.75%) and purines (18.64%). We found a low occurrence of "infection" stones. The sex ratio was related to stone composition and differed according to the main component. For instance, calcium oxalate dihydrate (COD) was more frequent in men than in women, with a sex ratio of 4.97 versus 2.57 for calcium oxalate monohydrate (COM). On the contrary, calcium phosphate was more frequent in female patients (sex ratio 0.72 versus overall ratio). The high frequency of COD calculi (23.17%) suggests that hypercalciuria is particularly frequent in French patients susceptible to stone formation. For each main component, a specific profile was observed in relation to the sex and age of the patients with stones.

Calcium oxalate stone disease: role of lipid peroxidation and antioxidants.

Abstract: Membrane injury facilitated the fixation of calcium oxalate crystals and subsequent growth into kidney stones. Oxalate-induced membrane injury was mediated by lipid peroxidation reaction through the generation of oxygen free radicals. In urolithic rat kidney or oxalate exposed cultured cells, both superoxide anion and hydroxyl radicals were generated in excess, causing cellular injury. In hyperoxaluric rat kidney, both superoxide and H2O2-generating enzymes such as glycolic acid oxidase (GAO) and xanthine oxidase (XO) were increased, and hydroxyl radical and transition metal ions, iron, and copper were accumulated. The lipid peroxidation products, thiobarbituric acid-reactive substances (TBARS), hydroperoxides, and diene conjugates were excessively released in tissues of urolithic rats and in plasma of rats as well as stone patients. The accumulation of these products was concomitant with the decrease in the antioxidant enzymes, superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), and glucose-6 phosphate dehydrogenase (G6PD) as well as radical scavengers, vitamin E, ascorbic acid, reduced glutathione (GSH), and protein thiol. All the above parameters were decreased in urolithic condition, irrespective of the agents used for the induction of urolithiasis. Oxalate binding activity and calcium oxalate crystal deposition were markedly pronounced, along with decreased adenosine triphosphatase (ATPase) activity. Lipid peroxidation positively correlated with cellular oxalate, oxalate binding, gamma-glutamyl carboxylase, and calcium level and negatively correlated with GSH, vitamin E. ascorbic acid, and total protein thiol. Antioxidant therapy to urolithic rats with vitamin E, glutathione monoester, methionine, lipoic acid, or fish oil normalised the cellular antioxidant system, enzymes and scavengers, and interrupted membrane lipid and protein peroxidation reaction, ATPase inactivation, and its associated calcium accumulation. Antioxidant therapy prevented calcium oxalate precipitation in the rat kidney and reduced oxalate excretion in stone patients. Similarly, calcium oxalate crystal deposition in vitro to urothelium was prevented by free radical scavengers such as phytic acid and mannitol by protecting the membrane from free radical-mediated damage. All these observations were suggestive of the active involvement of free radical-mediated lipid peroxidation-induced membrane damage in the pathogenesis of calcium oxalate crystal deposition and retention.

Promotive effect on human sperm progressive motility by prostasomes.

Abstract: Seminal plasma constituents were separated on Sephadex G200 gel columns. The column eluate was analysed with regard to protein content, ATPase activity and promotive activity on sperm progressive motility. Two different chromatographic fractions were also subjected to electron microscopy after sedimentation by preparative ultracentrifugation. A maximum promotive value on sperm progressive motility coincided with a maximum ATPase activity value in a single peak from seminal plasma eluted first on the column and containing less protein than the other peaks appearing later in the chromatogram. This first peak was the only one containing ATPase activity and membrane-surrounded organelles named prostasomes. Other peaks, rich in protein but lacking ATPase and prostasomes, displayed a moderate and rather irregular pattern in reference to promotive activity on sperm progressive motility. Evidence is given that the positive effect by prostasomes is specific on sperm progressive motility. Hence, procedures aiming at a change of membrane integrity of the prostasomes resulted in diminished effects on sperm progressive motility. This could be explained by a probable dissipation of the electrochemical gradient of calcium ions.