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H Urine Samples (h + urine_sample)
Selected AbstractsAssociation of absence of intestinal oxalate degrading bacteria with urinary calcium oxalate stone formationINTERNATIONAL JOURNAL OF UROLOGY, Issue 6 2003KAZUO MIKAMI Abstract Aim: Urinary concentration of oxalate is considered an important factor in the formation of renal stones. Dietary oxalate is a major contributor to urinary oxalate excretion in most individuals. Furthermore, oxalate degrading bacteria have been isolated from human feces. We investigated the significance of oxalate degrading bacteria for urinary oxalate excretion and urinary stone formation. Methods: Twenty-two known calcium oxalate stone-forming patients (stone formers) and 34 healthy volunteers (non-stone formers) were included in the study. Stool specimens were inoculated into pepton yeast glucose (PYG) medium supplemented with oxalate under anaerobic condition at 37 C for one week. After the incubation period, each colony was checked for the loss of oxalate from the culture medium. A 24-h urine sample was collected in 43 individuals and analyzed for oxalate excretion. Results: Twenty-eight of 34 (82%) healthy volunteers and 10 of 22 (45%) calcium oxalate stone formers were colonized with oxalate degrading bacteria. Calcium oxalate stone formers were more frequently free of oxalate degrading bacteria (P < 0.01). Urinary excretion of oxalate in those with oxalate degrading bacteria was significantly less than in those without oxalate degrading bacteria (P < 0.05). Hyperoxaluria (> 40 mg/day) was found in four of 27 individuals (15%) with oxalate degrading bacteria compared to seven of 16 (44%) without oxalate degrading bacteria (P < 0.05), suggesting an association between the absence of oxalate degrading bacteria and the presence of hyperoxaluria. Conclusion: The absence of oxalate degrading bacteria in the gut could promote the absorption of oxalate, thereby increasing the level of urinary oxalate excretion. The absence of oxalate degrading bacteria from the gut appears to be a risk factor for the presence of absorptive hyperoxaluria and an increased likelihood of urolithiasis. [source] Adrenarche and Bone Modeling and Remodeling at the Proximal Radius: Weak Androgens Make Stronger Cortical Bone in Healthy Children,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 8 2003Thomas Remer Abstract Adrenarche, the physiological increase in adrenal androgen secretion, may contribute to better bone status. Proximal radial bone and 24-h urinary steroid hormones were analyzed cross-sectionally in 205 healthy children and adolescents. Positive adrenarchal effects on radial diaphyseal bone were observed. Obviously, adrenarche is one determinant of bone mineral status in children. Introduction: Increased bone mass has been reported in several conditions with supraphysiological adrenal androgen secretion during growth. However, no data are available for normal children. Therefore, our aim was to examine whether adrenal androgens within their physiological ranges may be involved in the strengthening of diaphyseal bone during growth. Methods: Periosteal circumference (PC), cortical density, cortical area, bone mineral content, bone strength strain index (SSI), and forearm cross-sectional muscle area were determined with peripheral quantitative computed tomography (pQCT) at the proximal radial diaphysis in healthy children and adolescents. All subjects, aged 6,18 years, who collected a 24-h urine sample around the time of their pQCT analysis (100 boys, 105 girls), were included in the present study, and major urinary glucocorticoid (C21) and androgen (C19) metabolites were quantified using gas chromatography-mass spectrometry. Results and Conclusions: We found a significant influence of muscularity, but not of hormones, on periosteal modeling (PC) before the appearance of pubic hair (prepubarche). Similarly, no influence of total cortisol secretion (C21) was seen on the other bone variables. However, positive effects of C19 on cortical density (p < 0.01), cortical area (p < 0.001), bone mineral content (p < 0.001), and SSI (p < 0.001),reflecting, at least in part, reduction in intracortical remodeling,were observed in prepubarchal children after muscularity or age had been adjusted for. This early adrenarchal contribution to proximal radial diaphyseal bone strength was further confirmed for all cortical variables (except PC) when, instead of C19 and C21, specific dehydroepiandrosterone metabolites were included as independent variables in the multiple regression model. During development of pubic hair (pubarche), muscularity and pubertal stage rather than adrenarchal hormones seemed to influence bone variables. Our study shows that especially the prepubarchal increase in adrenal androgen secretion plays an independent role in the accretion of proximal radial diaphyseal bone strength in healthy children. [source] Urinary L-FABP and anaemia: distinct roles of urinary markers in type 2 diabetesEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2 2010M. Von Eynatten Eur J Clin Invest 2010; 40 (2): 95,102 Abstract Background, Urinary liver-type fatty acid binding protein (L-FABP) and kidney injury molecule (KIM)-1, novel urinary biomarkers of renal tubulointerstitial function, have previously been associated with acute ischaemic kidney injury. We studied the clinical significance of urinary L-FABP, KIM-1 and N -acetyl-,-glucosaminidase (NAG) as potential markers of renal function and chronic ischaemic injury in patients with diabetic nephropathy. Material and methods, A total of 130 type 2 diabetes patients with early diabetic nephropathy and 40 healthy controls were studied. Urinary L-FABP, KIM-1, NAG, albumin excretion rate (AER) and creatinine clearance were obtained from 24-h urine samples, and correlated with measures of red blood cell count, renal function and metabolic control. Results, Urinary L-FABP was significantly increased in diabetes patients compared with healthy controls [8·1 (interquartile 0·6,11·6) vs. 2·4 (0·5,3·6) ,g/g creatinine, P < 0·001] and correlated with AER (r = 0·276, P = 0·002), creatinine clearance (r = ,0·189, P = 0·033) and haemoglobin levels (r = ,0·190, P = 0·030). In multivariable linear regression analysis, haemoglobin (, = ,0·247, P = 0·015) and AER (, = 0·198, P = 0·046) were significant predictors of urinary L-FABP. Prevalent anaemia was independently associated with a 6-fold risk for increased tubulointerstitial kidney damage (upper vs. lower two L-FABP tertiles: OR, 6·06; 95% CI: 1·65,22·23; P = 0·007). Urinary KIM-1 was not significantly associated with kidney function, AER, or measures of red blood cell count while urinary NAG was associated with parameters of glucose control and renal function. Conclusions, Different urinary biomarkers may reflect distinct pathophysiological mechanisms of tubulointerstitial damage in early diabetic nephropathy: Urinary L-FABP could be a novel biomarker for chronic intrarenal ischaemia. [source] A Vacuolar ATPase Inhibitor, FR167356, Prevents Bone Resorption in Ovariectomized Rats With High Potency and Specificity: Potential for Clinical Application,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 9 2005Kazuaki Niikura MS Abstract FR167356, a novel inhibitor of vacuolar ATPase, has high potency against osteoclast V-ATPase and low potency against lysosomal V-ATPase. FR167356 is the first compound of this nature to be tested. It has the potential to be useful for clinical application. Introduction: It has been suggested that the key issue regarding the therapeutic usefulness of V-ATPase inhibitors is their selectivity. Materials and Methods: In in vitro and in vivo studies, we compared FR167356 with other vacuolar ATPase (V-ATPase) inhibitors, bafilomycin A1 and SB242784. H+ transport by various membrane vesicles was assayed by measuring uptake of acridine orange. Inhibitory activity against in vitro bone resorption was examined by measuring the Ca2+ release from cultured calvariae. In vivo, hypercalcemia was induced by retinoic acid in thyroparathyroidectomized-ovariectomized rats, and the effect on serum Ca2+ level was assessed. Ovariectomized rats were treated with FR167356 or SB242784. One week after surgery, free deoxypyridinoline levels in 24-h urine samples, which were collected from 6 h after administration of FR167356, were measured by ELISA. After 4 weeks of treatment, plasma biochemical parameters were analyzed. BMD of the distal femur metaphysis was measured with pQCT. Histomorphometric analysis of the proximal tibias was performed. Blood gases of rats treated with FR167356 were measured with a blood gas analyzer for estimating the effect of FR167356 on in vivo function of renal V-ATPase. Results: FR167356, which is distinctly different from other V-ATPase inhibitors, has a high potency against osteoclast V-ATPase and low potency against lysosomal V-ATPase. Similarly, FR167356 inhibited bone resorption in vitro when stimulated by PTH, IL-1, and IL-6. FR167356 reduced retinoic acid-induced hypercalcemia in thyroparathyroidectomized-ovariectomized rats in a dose-dependent manner. Moreover, FR167356 was shown to restore BMD of ovariectomized rats caused by the inhibition of bone resorption. Ovariectomized rats treated with FR167356 did not show adverse symptoms, whereas SB242784 caused a decrease in body weight gain and significant changes in two plasma biochemical parameters. Interestingly, FR167356 treatment did not affect blood acid-base balance; however, FR167356 inhibited renal V-ATPase with a similar potency as for osteoclast V-ATPase inhibition. Conclusion: Comparison of FR167356 with SB242784 implies that the characteristics of FR167356 may be more appropriate for clinical application as a V-ATPase inhibitor. [source] Investigation of the effects of concomitant caffeine administration on the metabolic disposition of pyrazinamide in ratsBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 5 2002Aida Mehmedagic Abstract The utility of pyrazinamide (PZA) in the short-course antituberculous treatment is well established. All available data support the idea that the PZA metabolite pyrazinoic acid (PA) is the active compound against M. tuberculosis. This situation warranted a deeper investigation of possible interactions with respect to its metabolic disposition. Caffeine, which is widely used as a drug and is a common constituent of most diets, shares with PZA the same metabolic enzyme, xanthine oxidase (XO). This study investigated if, and in what manner, concomitant administration of caffeine affects PZA metabolism. PZA and caffeine, in various doses (PZA=50 or 100 mg kg,1 and caffeine= 0, 50, 100, and 150 mg kg,1), were administered to female Sprague-Dawley rats. PZA and its three main metabolites were quantified in 24 h urine samples by reversed phase-HPLC Concomitant administration of 100 mg kg,1 caffeine and 50 mg kg,1 PZA increased from the excretion (p<0.05) of the most water-soluble and the least toxic PZA metabolite 5-hydroxypyrazinoic acid (5-OH-PA) from 66.18±10.87 to 94.56±8.65 ,mol/24 h. This effect was more pronounced when 100 mg kg,1 of PZA was administered increasing excretion of 5-OH-PA from 113.28±70 to 173.23±17.82 ,mol/24 h. These results show that the metabolic disposition of PZA is affected by concomitant caffeine intake. Copyright © 2002 John Wiley & Sons, Ltd. [source] | ||||||||||