Energetic signatures of single base bulges: thermodynamic consequences and biological implications

DNA bulges are biologically consequential defects that can arise from template-primer misalignments during replication and pose challenges to the cellular DNA repair machinery. Calorimetric and spectroscopic characterizations of defect-containing duplexes reveal systematic patterns of sequence-context dependent bulge-induced destabilizations. These distinguishing energetic signatures are manifest in three coupled characteristics, namely: the magnitude of the bulge-induced duplex destabilization (ΔΔGBulge); the thermodynamic origins of ΔΔGBulge (i.e. enthalpic versus entropic); and, the cooperativity of the duplex melting transition (i.e. two-state versus non-two state). We find moderately destabilized duplexes undergo two-state dissociation and exhibit ΔΔGBulge values consistent with localized, nearest neighbor perturbations arising from unfavorable entropic contributions. Conversely, strongly destabilized duplexes melt in a non-two-state manner and exhibit ΔΔGBulge values consistent with perturbations exceeding nearest-neighbor expectations that are enthalpic in origin. Significantly, our data reveal an intriguing correlation in which the energetic impact of a single bulge base centered in one strand portends the impact of the corresponding complementary bulge base embedded in the opposite strand. We discuss potential correlations between these bulge-specific differential energetic profiles and their overall biological implications in terms of DNA recognition, repair and replication

The effect of surgeon volume and hospital characteristics on in-hospital outcome after ureteral reimplantation in children

The aim of this study was to examine the association between surgeon and hospital characteristics on in-hospital outcome after ureteral reimplantation in children. Patients \u3c 18 years undergoing vesicoureteral reimplantation (n = 3,109) were identified in Kids\u27 Inpatient Database, an administrative database containing discharge records from 27 states during 2000 in the US. Based on patient volume in 2000, surgeons were designated as low volume (\u3c 11 procedures), medium volume (11-20 procedures) and high volume (\u3e 20 procedures) surgeons. Length of stay and hospital charges were analyzed using multivariate linear regression analysis.A significant association between shorter length of stay and higher surgeon volume (p = 0.02) was observed that was independent of children\u27s hospital status, hospital volume and other hospital characteristics. Length of stay was 20% shorter when the procedure was performed by the highest volume surgeons compared to when performed by the lowest. No significant effect of surgeon volume on hospital charges, however, was observed. Higher surgeon volume was associated with shorter length of stay but no difference in hospital charges among children undergoing vesicoureteral reimplantation. © Springer-Verlag 2006

The effect of surgeon volume and hospital characteristics on in-hospital outcome after ureteral reimplantation in children

The aim of this study was to examine the association between surgeon and hospital characteristics on in-hospital outcome after ureteral reimplantation in children. Patients \u3c 18 years undergoing vesicoureteral reimplantation (n = 3,109) were identified in Kids\u27 Inpatient Database, an administrative database containing discharge records from 27 states during 2000 in the US. Based on patient volume in 2000, surgeons were designated as low volume (\u3c 11 procedures), medium volume (11-20 procedures) and high volume (\u3e 20 procedures) surgeons. Length of stay and hospital charges were analyzed using multivariate linear regression analysis.A significant association between shorter length of stay and higher surgeon volume (p = 0.02) was observed that was independent of children\u27s hospital status, hospital volume and other hospital characteristics. Length of stay was 20% shorter when the procedure was performed by the highest volume surgeons compared to when performed by the lowest. No significant effect of surgeon volume on hospital charges, however, was observed. Higher surgeon volume was associated with shorter length of stay but no difference in hospital charges among children undergoing vesicoureteral reimplantation. © Springer-Verlag 2006

Effects of mTOR Inhibitor Everolimus (RAD0011) On Bladder Cancer Cells

Purpose: We investigated the effect of the mTOR inhibitor everolimus (RAD001) on human bladder cancer cells in vitro and in vivo. Experimental Design: The UM-UC-3, UM-UC-6, UM-UC-9 and UM-UC-14 cell lines were treated at different concentrations of RAD001. Growth effect was assessed by crystal violet assays at different time courses, with or without RAD001 re-dosing. Flow cytometric cell cycle analyses, propidium iodide exclusion and annexin V assays were performed. Tritium radiolabeled leucine incorporation and western blot assays were also performed. In vivo experiments were performed using nude mice subcutaneously implanted with UM-UC-3, UM-UC-6, and UM-UC-9 and treated with orally RAD001 or placebo. Tumors were harvested for immunohistochemistry. Results: The RAD001 treated bladder cancer cells showed transient growth inhibition in a dosedependent manner, with growth inhibition augmented by re-treatment after 3 days. UMUC-14 was most sensitive to RAD001 therapy while UM-UC-9 was least sensitive.RAD001 showed G1 growth phase arrest only after prolonged treatment in sensitive cell lines. There was no evidence of apoptosis. Significant tumor growth inhibition compared to controls was shown in murine subcutaneous tumors from UM-UC-3, UM-UC-6, and UM-UC-9 cell lines. Protein synthesis inhibition via S6K and 4EBP1 pathway appears to be the main mechanism of bladder cancer cell growth inhibition by RAD001. However, inhibition of angiogenesis was the predominant mechanism for UM-UC-9 cells. Conclusions: The mTOR inhibitor RAD001 inhibits growth of bladder cancer cells in vitro. RAD001 is effective in treating bladder cancer in vivo, in spite of heterogeneity of tumor response in vitro

Mitomycin Gel (UGN-101) as a Kidney-sparing Treatment for Upper Tract Urothelial Carcinoma in Patients with Imperative Indications and High-grade Disease.

BACKGROUND: Intracavitary UGN-101 is approved for the treatment of low-grade noninvasive upper tract urothelial carcinoma (UTUC). Post-commercialization studies underscore the benefit of UGN-101 administration for patients with imperative indications for whom radical nephroureterectomy (RNU) is not a viable option. OBJECTIVE: To describe the use, efficacy, and safety of UGN-101 in patients with UTUC with imperative indications for renal preservation, including high-grade disease. DESIGN, SETTING, AND PARTICIPANTS: Patients receiving UGN-101 with imperative indications were retrospectively analyzed using a multicenter centralized registry from 15 high-volume academic and community centers. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We defined imperative indications as patients with a solitary kidney, the presence of chronic kidney disease (CKD) with a glomerular filtration rate/min, bilateral UTUC, and patients unfit for or unwilling to undergo surgical extirpation. Tumor characteristics, disease progression/recurrence, and adverse events were recorded on a per-renal-unit basis. RESULTS AND LIMITATIONS: UGN-101 was instilled into 52 renal units (38%) in 48 patients for imperative indications, including 29 patients (56%) with a solitary kidney, 11 kidneys (21%) in the setting of bilateral UTUC, six patients (12%) with CKD, and six patients (12%) who were unfit for or unwilling to undergo RNU. Twelve renal units had biopsy-proven high-grade papillary disease. Tumors were completely ablated before induction therapy in 34% of cases, while 66% had tumor present. Following induction therapy, 17 patients (40%) had no evidence of disease (NED) on ureteroscopy, 88% of whom maintained this status at median follow-up of 10.8 mo. In the cohort with high-grade disease, five patients (45%) had NED at initial post-induction primary disease evaluation. Adverse events included pyelonephritis (8%), ureteral stenosis (8%), anemia (6%), and acute renal failure (4%). Limitations include the retrospective study design, the lack of long-term follow up, and patient selection bias. CONCLUSIONS: Intracavitary therapy with UGN-101 in patients with UTUC and imperative indications shows promise as a kidney-sparing treatment modality. While long-term follow-up is needed, this intracavitary treatment may help in prolonging time to RNU and delaying the morbidity of hemodialysis in this comorbid population. PATIENT SUMMARY: We reviewed results for patients with cancer in the upper urinary tract and an additional condition that would not allow kidney removal who received treatment with a gel called UGN-101. Our results suggest that UGN-101 shows promise as a kidney-sparing treatment. It may delay the time until kidney removal is needed in these patients and avoid the negative effects associated with dialysis