Background And Purpose: Oxalobacter formigenes is an anaerobic commensal colonic bacterium capable of degrading oxalate through the enzyme oxalyl-CoA decarboxylase. It has been theorized that individuals who lack this bacterium have higher intestinal oxalate absorption, leading to a higher urinary oxalate concentration and an increased risk of calcium oxalate urolithiasis. We performed a prospective, controlled study to evaluate O. formigenes colonization in calcium oxalate stone formers and to correlate colonization with urinary oxalate and other standard urinary stone risk factors.
Patients And Methods: Thirty-five first-time calcium oxalate stone formers were compared with 10 control subjects having no history of urolithiasis and a normal renal ultrasound scan. All subjects underwent standard metabolic testing by submitting serum and 24-hour urine specimens. In addition, all subjects submitted stool samples for culture and detection of O. formigenes by Xentr(ix) O. formigenes Monitor.
Results: Intestinal Oxalobacter was detected in only 26% of the stone formers compared with 60% of the controls (p < 0.05). Overall, the average urinary oxalate excretion by the two groups was similar (38.6 mg/day v 40.8 mg/day). Among stone formers, however, there were statistically higher urinary oxalate concentrations in O. formigenes-negative patients compared with those testing positive (41.7 mg/day v 29.4 mg/day) (p = 0.03). Furthermore, all 10 stone formers with hyperoxaluria (>44 mg/day) tested negative for O. formigenes (p < 0.05).
Conclusions: Calcium oxalate stone formers have a low rate of colonization with O. formigenes. Among stone formers, absence of intestinal Oxalobacter correlates with higher urinary oxalate concentration and an increased risk of hyperoxaluria. Introduction of the Oxalobacter bacterium or an analog of its enzyme oxalyl-CoA decarboxylase into the intestinal tract may be a treatment for calcium oxalate stone disease.
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http://dx.doi.org/10.1089/089277903321618743 | DOI Listing |
Med J Islam Repub Iran
October 2024
Department of Urology, Shohada-e-Tajrish Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Background: Nephrolithiasis is a common condition that has been linked to various systemic diseases. Recent studies have suggested that young patients with nephrolithiasis are at increased risk of developing premature atherosclerosis. This study aims to investigate the relationship between nephrolithiasis and systemic disease by examining the association between aortic calcification and the severity of kidney stone disease.
View Article and Find Full Text PDFJ Paleolit Archaeol
July 2024
Laboratory of Theriology, Zoological Institute of the Russian Academy of Sciences, St. Petersburg, Russian Federation.
The Altai mountains contain a number of cave and rockshelter sites that have given crucial information about human evolution in Asia. Most of these caves are located in the Gornyi Altai of Siberia, while the southern flank of the range remains much less known. Bukhtarma Cave was a karstic cave located near the former village of Peshchera, on the banks of the Bukhtarma River running through the foothills of the southern (Kazakh) Altai mountains.
View Article and Find Full Text PDFNat Med
January 2025
Department of Nephrology and Hypertension, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
Introduction: Free radical-mediated oxidative renal tubular injury secondary to hyperoxaluria is a proposed mechanism in the formation of calcium oxalate stones. Vitamin E, an important physiologic antioxidant, has been shown in rat models to prevent calcium oxalate crystal deposition. Our objective was to determine if low dietary vitamin E intake was associated with a higher incidence of stones.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
Beijing National Laboratory for Molecular Sciences, N, ew Corner-Stone Science Laboratory, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
Metal carbides with earth-abundant elements are widely regarded as promising alternatives to noble metal catalysts. Although comparable catalytic performances have been observed for metal carbides in several types of reactions, precise control of reaction pathways on them remains a formidable challenge, partially due to strong adsorption of reactants or intermediates. In this study, we show that bimolecular dehydrogenation of methanol to methyl formate and H is kinetically favored on bare α-MoC catalysts, while monomolecular dehydrogenation to CO and H becomes the dominant pathway when α-MoC is decorated with crowding atomic Ni species.
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