Does Severity of Renal Scarring on DMSA Scan Predict Abnormalities in Creatinine Clearance?
Department of Urology, University of California, San Francisco, USA. Urology
(Impact Factor: 2.19).
07/2010; 76(1):204-8. DOI: 10.1016/j.urology.2010.03.010
To examine the relationship between severity of renal scarring and creatinine clearance. Existing studies on renal scarring and functional outcomes have focused on the presence or absence of scarring.
Patients with a history of urinary tract infection leading to the diagnosis of vesicoureteral reflux were recruited. These subjects were admitted to a pediatric research center for an in-patient collection of 24-hour urine to be sent for creatinine and protein. DMSA scans performed at least 6 months after documented urinary tract infection were graded by 3 independent, blinded pediatric urologists for renal scarring according to the Randomized Intervention for Children with Vesicoureteral Reflux study criteria.
Twenty-nine subjects (14 girls, 15 boys) with a median age of 7 years were recruited. Scar grading was reliable between the observers with a Kappa score of 0.66-0.75. On DMSA scan, 10% were scar-free, 62% had unilateral scars, and 28% had bilateral scars. Mean creatinine clearance was 123 for those with unilateral disease and 100 for those with bilateral disease (P = .048). Median proteinuria (58 mg/dL) and serum creatinine (0.5 mg/dL) were similar between the 2 groups. Creatinine clearance did not differ according to average scar grade, taking both kidneys into account.
In children with vesicoureteral reflux, although those with bilateral scarring have a significantly lower creatinine clearance than those with unilateral scarring, the severity of scar grade alone does not predict overall creatinine clearance with short-term follow-up.
Available from: Ivan Benkovsky
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ABSTRACT: The dimercaptosuccinic acid (DMSA) stability at pH = 3.8, 7.1, 8.8 and the interaction with SnCl2·2H2O were investigated. The degradation of DMSA is the most significant at alkali pH. There where observed oxidized and dimerized
forms of DMSA and fumaric acid presence. Progress of instability is less substantial and slower under neutral reaction conditions.
At acidic pH the concentration of soluble DMSA decreases with the time. The ligand forms with SnCl2 complex under alkali pH = 8.8 and its chemical formula was determined as Sn(DMSA)2.
Journal of Radioanalytical and Nuclear Chemistry 09/2011; 289(3). DOI:10.1007/s10967-011-1181-0 · 1.03 Impact Factor
Available from: Rod Blais
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ABSTRACT: Computer simulations are an increasingly important area of geoscience research and development. At the core of stochastic or Monte Carlo simulations are the random number sequences that are assumed to be distributed with specific characteristics. Computer-generated random numbers, uniformly distributed on (0, 1), can be very different depending on the selection of pseudo-random number (PRN) or chaotic random number (CRN) generators. In the evaluation of some definite integrals, the resulting error variances can even be of different orders of magnitude. Furthermore, practical techniques for variance reduction such as importance sampling and stratified sampling can be applied in most Monte Carlo simulations and significantly improve the results. A comparative analysis of these strategies has been carried out for computational applications in planar and spatial contexts. Based on these experiments, and on some practical examples of geodetic direct and inverse problems, conclusions and recommendations concerning their performance and general applicability are included.
Computers & Geosciences 07/2011; 37(7):928-934. DOI:10.1016/j.cageo.2011.01.009 · 2.05 Impact Factor
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ABSTRACT: We analyzed whether newly developed or aggravated hydronephrosis deteriorates differential renal function after extravesical ureteral reimplantation.
We performed extravesical ureteral reimplantation in 93 patients with unilateral vesicoureteral reflux between January 2006 and December 2009. Excluding 3 patients with other combined disease, a retrospective cohort analysis of 90 consecutive patients was conducted. We performed ultrasonography before and 1 month after extravesical ureteral reimplantation, and dimercapto-succinic acid scan before and 6 months after extravesical ureteral reimplantation. Of the patients 83 underwent final dimercapto-succinic acid scan at 6 months postoperatively. We analyzed the preoperative studies and perioperative parameters to evaluate the factors affecting newly developed or aggravated hydronephrosis at 1 month, and decrease in differential renal function at 6 months after extravesical ureteral reimplantation.
Newly developed or aggravated hydronephrosis was observed in 25 patients (28.4%) 1 month after extravesical ureteral reimplantation. Younger age at surgery was a risk factor (p = 0.003). Of the patients 23 showed improvement on ultrasound 6 months postoperatively. In 12 patients (15.7%) a decrease in differential renal function of more than 5% was observed 6 months postoperatively. Preoperative parenchymal reduction on dimercapto-succinic acid scan was the only significant factor (p = 0.008). There was no correlation between newly developed or aggravated hydronephrosis and final decrease in differential renal function (p >0.999).
Although newly developed or aggravated hydronephrosis after extravesical ureteral reimplantation is common, especially in younger patients, it is transient and does not affect differential renal function. A postoperative decrease in differential renal function without further urinary tract infection could develop when there is a parenchymal reduction on preoperative dimercapto-succinic acid scan.
The Journal of urology 12/2011; 187(2):670-5. DOI:10.1016/j.juro.2011.10.019 · 4.47 Impact Factor
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