Publications (92) View all
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Article: Repair of the Vesicoureteral Reflux
New England Journal of Medicine 07/2011; 365(3):269. · 53.30 Impact Factor -
Article: Evaluation of dynamic contrast-enhanced MRI in detecting renal scarring in a rat injury model.
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ABSTRACT: To create a reliable rat model with small renal cortical scars and evaluate the accuracy and sensitivity of dynamic contrast-enhanced MRI in detecting the kinds of lesions that are associated with reflux nephropathy. In 16 rats, three unilateral renal cortical lesions were created using either electrocautery or pure alcohol with the contralateral kidney serving as control. MRI on a 1.5 Tesla GE Signa was performed 10-14 days after surgery. After bolus injection of 0.2 mM/Kg Gd-DTPA, sequential MRI acquisitions were performed using a 4-inch quadrature birdcage coil. Renal and scar volumes and pathology were compared after scanning and killing. Of the 48 points of injury, 40 (83%) in the 16 rats were detected grossly. Under microscopy, 36 injuries (75%) were detected on mid-kidney cross-sections. The average lesion was 4.2 mm(3) corresponding to 0.5% of the kidney volume. Using pathological findings as the gold standard, the sensitivity and specificity of scar detection using MRI was 69% and 93%, respectively. A rat model was created to demonstrate the sensitivity of dynamic contrast-enhanced MRI for detecting renal scars. Alcohol and electrocautery created reliable renal scars that were confirmed pathologically. MRI detected these lesions that averaged 4.2 mm(3) (0.5% total renal volume) with sensitivity and specificity of 69% and 93%, respectively.Journal of Magnetic Resonance Imaging 05/2010; 31(5):1132-6. · 2.70 Impact Factor -
Article: Three differentiation states risk-stratify bladder cancer into distinct subtypes.
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ABSTRACT: Current clinical judgment in bladder cancer (BC) relies primarily on pathological stage and grade. We investigated whether a molecular classification of tumor cell differentiation, based on a developmental biology approach, can provide additional prognostic information. Exploiting large preexisting gene-expression databases, we developed a biologically supervised computational model to predict markers that correspond with BC differentiation. To provide mechanistic insight, we assessed relative tumorigenicity and differentiation potential via xenotransplantation. We then correlated the prognostic utility of the identified markers to outcomes within gene expression and formalin-fixed paraffin-embedded (FFPE) tissue datasets. Our data indicate that BC can be subclassified into three subtypes, on the basis of their differentiation states: basal, intermediate, and differentiated, where only the most primitive tumor cell subpopulation within each subtype is capable of generating xenograft tumors and recapitulating downstream populations. We found that keratin 14 (KRT14) marks the most primitive differentiation state that precedes KRT5 and KRT20 expression. Furthermore, KRT14 expression is consistently associated with worse prognosis in both univariate and multivariate analyses. We identify here three distinct BC subtypes on the basis of their differentiation states, each harboring a unique tumor-initiating population.Proceedings of the National Academy of Sciences 02/2012; 109(6):2078-83. · 9.68 Impact Factor -
Article: Trends in hospitalization for pediatric pyelonephritis: a population based study of California from 1985 to 2006.
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ABSTRACT: We examined trends in pediatric hospitalization for pyelonephritis from 1985 to 2006 and identified factors associated with admission. We performed a population based analysis of hospital discharges using the Office of Statewide Health Planning and Development database to evaluate trends in California regarding pediatric hospitalizations for pyelonephritis from 1985 to 2006. Multivariable logistic regression was performed to identify factors associated with admission for pyelonephritis. A total of 46,300 children were hospitalized for pyelonephritis in California from 1985 to 2006. The overall rate of hospitalization for pyelonephritis increased by greater than 80%, from 17 per 100,000 children in the California population in 1985 to 31 per 100,000 in 2005. This change was primarily due to the nearly ninefold increase in pyelonephritis hospitalizations observed in children younger than 1 year, from 28 per 100,000 in 1985 to 238 per 100,000 in 2005. Among children younger than 1 year males without private insurance and of nonwhite race had increased odds of hospitalization, while females with private insurance and of Asian race had increased odds of hospitalization, compared with nonprivate insurance and white race, respectively. A significant increase in hospital admissions for pyelonephritis, primarily in children younger than 1 year, occurred in California between 1985 and 2006. Further studies are needed to establish the cause of this striking increase and to determine why certain pediatric populations are at increased risk for hospitalization.The Journal of urology 09/2011; 186(3):1028-34. · 4.02 Impact Factor -
Article: Epidemiologic trends in penile anomalies and hypospadias in the state of California, 1985-2006.
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ABSTRACT: Using statewide data, we evaluated whether the changing incidence of penile anomalies and hypospadias is reflected in the diverse California population of newborn males over the past 20 years. Discharge data from all California hospitals, prepared by the OSHPD (Sacramento, CA) was reviewed for the years 1985-2006 for male infant births with an ICD-9 code (752.6) for hypospadias, epispadias or other penile anomalies. Trends were examined by Generalized Estimation Equations for Poisson regression. From 1985 to 2006, the birth incidence of newborn penile anomalies increased in California from 47 to 57 cases per 10,000 newborn discharges, yet the trend for hypospadias alone appears stable from 1997. The rates for penile anomalies in newborns increased 1.4% annually (p < 0.001). All racial/ethnic groups analyzed showed this increase (p < 0.001 for each). During the study period there was a 2% increase per year in plural births (p < 0.001). Interestingly, the rate of change in penile anomaly incidence was greater in males of plural births compared to their singleton cohorts (2% vs 1% annually) (p < 0.001). The birth incidence of cleft palate, another congenital anomaly known to be stable over time, remained unchanged over this period. From 1985 to 2006 in California the incidence of penile anomalies increased in a statistically significant manner, but the incidence of hypospadias appears stable for the last decade. Our data support the notion that different racial/ethnic groups have distinct incidences of penile anomaly formation and that an association with plural births appears to be present.Journal of pediatric urology 06/2011; 7(3):294-8. · 1.38 Impact Factor
