Mechanism of PCNA loading by Ctf18-RFC for leading-strand DNA synthesis.

The proliferating cell nuclear antigen (PCNA) clamp encircles DNA to hold DNA polymerases (Pols) to DNA for processivity. The Ctf18-RFC PCNA loader, a replication factor C (RFC) variant, is specific to the leading-strand Pol (Polε). We reveal here the underlying mechanism of Ctf18-RFC specificity to Polε using cryo-electron microscopy and biochemical studies. We found that both Ctf18-RFC and Polε contain specific structural features that direct PCNA loading onto DNA. Unlike other clamp loaders, Ctf18-RFC has a disordered ATPase associated with a diverse cellular activities (AAA+) motor that requires Polε to bind and stabilize it for efficient PCNA loading. In addition, Ctf18-RFC can pry prebound Polε off of DNA, then load PCNA onto DNA and transfer the PCNA-DNA back to Polε. These elements in both Ctf18-RFC and Polε provide specificity in loading PCNA onto DNA for Polε.

A Multinational, Multi-Institutional Study Assessing the Impact of Diabetes Mellitus on the Prognosis of Patients with Non-Muscle Invasive Bladder Cancer Treated with Bacillus Calmette-Guérin.

The study aimed to examine the impact of diabetes mellitus type 2 (DMII) on the oncological outcomes of non-muscle invasive bladder cancer (NMIBC) treated with Bacillus Calmette-Guérin (BCG) using comprehensive real-world data. We performed an analysis of data on NMIBC patients treated with BCG from the United States (US) National Phase II BCG/Interferon (IFN) trial database (125 centers) and pooled databases from three tertiary care institutions: France (FR), Lebanon (LB) (2000-2021), and the US (University of Iowa) (2011-2021). There were 867 patients from the Phase II trial, 1232 from the FR/LB cohort, and 233 from the US (Iowa) cohort (n = 2332). DM II was reported in 13% of the Phase II trial cohort, 14.4% of the FR/LB cohort, and 33.5% of the US (Iowa) cohort. The median follow-up was 24 months in the Phase II trial cohort, 25 months in the FR/LB cohort, and 48 months in the US (Iowa) cohort. In multivariable Cox regression analyses, DMII was not significantly associated with recurrence or progression of the tumor in any of the cohorts included in this study. DMII may not be a clinical prognostic factor for NMIBC patients treated with BCG. Prospective evaluation is needed.

Hemospray® (hemostatic powder TC-325) as monotherapy for acute gastrointestinal bleeding: a multicenter prospective study.

Background: Hemostatic powders are used as second-line treatment in acute gastrointestinal (GI) bleeding (AGIB). Increasing evidence supports the use of TC-325 as monotherapy in specific scenarios. This prospective, multicenter study evaluated the performance of TC-325 as monotherapy for AGIB. Methods: Eighteen centers across Europe and USA contributed to a registry between 2016 and 2022. Adults with AGIB were eligible, unless TC-325 was part of combined hemostasis. The primary endpoint was immediate hemostasis. Secondary outcomes were rebleeding and mortality. Associations with risk factors were investigated (statistical significance at P≤0.05). Results: One hundred ninety patients were included (age 51-81 years, male: female 2:1), with peptic ulcer (n=48), upper GI malignancy (n=79), post-endoscopic treatment hemorrhage (n=37), and lower GI lesions (n=26). The primary outcome was recorded in 96.3% (95% confidence interval [CI]: 92.6-98.5) with rebleeding in 17.4% (95%CI 11.9-24.1); 9.9% (95%CI 5.8-15.6) died within 7 days, and 21.7% (95%CI 15.6-28.9) within 30 days. Regarding peptic ulcer, immediate hemostasis was achieved in 88% (95%CI 75-95), while 26% (95%CI 13-43) rebled. Higher ASA score was associated with mortality (OR 23.5, 95%CI 1.60-345; P=0.02). Immediate hemostasis was achieved in 100% of cases with malignancy and post-intervention bleeding, with rebleeding in 17% and 3.1%, respectively. Twenty-six patients received TC-325 for lower GI bleeding, and in all but one the primary outcome was achieved. Conclusions: TC-325 monotherapy is safe and effective, especially in malignancy or post-endoscopic intervention bleeding. In patients with peptic ulcer, it could be helpful when the primary treatment is unfeasible, as bridge to definite therapy.

Sequential Endoluminal Gemcitabine and Cabazitaxel with Intravenous Pembrolizumab as a Bladder-Preserving Strategy for Docetaxel-Unresponsive Non-Muscle Invasive Urothelial Carcinoma Following Transurethral Resection of Bladder Tumor.

Growing evidence suggests that many patients with high-risk non-muscle invasive urothelial carcinoma (NMIUC) can undergo bladder-sparing management with salvage intravesical therapies. However, inherent or developed disease resistance, particularly after multiple lines of prior salvage therapy, implores the continued pursuit of new treatment combinations. Herein, we describe the outcomes of 26 patients (31 treated units; 24 lower tract, 7 upper tract) with high-risk NMIUC treated with sequential intravesical gemcitabine and cabazitaxel with concomitant intravenous pembrolizumab (GCP) at the University of Iowa from August 2020 to February 2023. Median (IQR) follow-up was 30 (IQR: 17-35) months. Treated units had a history of high-risk NMIUC with a median of four prior endoluminal inductions. Overall, 87% of units presented with CIS or positive urine cytology. The 1- and 2-year recurrence-free survival was 77% (CI: 58-88%) and 52% (CI: 30-70%), respectively. The 2-year progression-free and cancer-specific survival was 70% (CI: 44-85%) and 96% (CI: 75-99%), respectively. In total, 22/26 (85%) patients reported any adverse event and 5/26 (19%) reported a grade ≥3 adverse event; however, all patients tolerated a full induction course. These results suggest that GCP is an effective and tolerable treatment option for patients with recurrent high-risk NMIUC.

Prognostic role of the neutrophil/lymphocyte ratio in high-risk BCG-naïve non-muscle-invasive bladder cancer treated with intravesical gemcitabine/docetaxel.

OBJECTIVES: To investigate the role of pretreatment neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in the prediction of response to sequential intravesical therapy, gemcitabine and docetaxel (Gem/Doce), given to patients with bacille Calmette-Guérin (BCG)- naïve high-risk non-muscle-invasive bladder cancer (NMIBC). PATIENTS AND METHODS: A retrospective analysis was conducted on 115 patients who received intravesical Gem/Doce for high-risk NMIBC between January 2011 and December 2021. Data were computed as the median (interquartile range [IQR]) or mean (standard deviation [sd]). Cox regression analysis was performed to determine if neutrophilia, NLR, platelet counts, and PLR before instillation therapy were predictive of recurrence-free survival (RFS) and overall survival (OS). Predictive performance was estimated using Uno's C-statistic. RESULTS: The median (IQR) follow-up for the overall cohort was 23 (13-36) months. The mean (sd) values for NLR, PLR and platelet counts were 3.4 (2.3), 142.2 (85.5), and 225.2 (75.1) × 109/L, respectively. NLR was associated with RFS, with a hazard ratio of 1.32 (95% confidence interval CI 1.19-1.46). Concordance analysis showed that NLR had a good ability to predict RFS (C-index: 0.7, P < 0.01). The PLR and platelet count were not associated with RFS and did not predict recurrence. In terms of OS, none of these cellular inflammatory markers showed any prediction value. CONCLUSION: Pre-treatment NLR provides some predictive accuracy for RFS in high-risk BCG-naïve patients receiving Gem/Doce. Further prospective trials are needed to validate this finding.

Establishing an Intravesical Doublet Chemotherapy Clinic for Nonmuscle-Invasive Bladder Cancer Patients.

INTRODUCTION: Intravesical sequential doublet chemotherapy (SDC) is being used increasingly as a rescue treatment for nonmuscle-invasive bladder cancer failing bacillus Calmette-Guérin (BCG), as single-agent chemotherapies are less effective, especially for carcinoma in situ. Considering the current BCG shortage, intravesical SDC also provides an efficacious alternative to BCG. Our aim is to detail the implementation to assist with establishing an efficient and practical intravesical SDC clinic for urologic practice. METHODS: We searched PubMed for published studies with the Medical Subject Heading of "intravesical chemotherapy" and "non-muscle invasive bladder cancer." The search was limited to English-language journals and full papers only. The initial search resulted in 260 articles, of which 20 relevant studies were selected. RESULTS: Five important processes were identified in the successful and efficient administration of intravesical SDC: (1) patient preparation, (2) medication procurement, (3) medication administration, (4) medication immediate aftermath, and (5) patient instruction and education. Safety precautions should be taken when handling each chemotherapy drug. A clinical pharmacist may be required for drug preparation. An important step in providing intravesical SDC is to use a closed system for the instillation of the chemo-solution. A special protocol should be adopted for every drug with its proper dwell time. The induction course consists of weekly instillation for 6 weeks. If an initial response is noted, maintenance therapy is recommended, typically monthly for 24 months. CONCLUSIONS: Successful intravesical SDC clinics necessitate appropriate patient selection, standardized workflow procedures, patient education, and good communication between the urologist, clinical pharmacists, and oncology nurses.

Proton-driven sodium secretion in a saline water animal.

Aquatic animals residing in saline habitats either allow extracellular sodium concentration to conform to environmental values or regulate sodium to lower levels. The latter strategy requires an energy-driven process to move sodium against a large concentration gradient to eliminate excess sodium that diffuses into the animal. Previous studies of invertebrate and vertebrate species indicate a sodium pump, Na+/K+ ATPase, powers sodium secretion. We provide the first functional evidence of a saline-water animal, Aedes taeniorhynchus mosquito larva, utilizing a proton pump to power this process. Vacuolar-type H+ ATPase (VHA) protein is highly expressed on the apical membrane of the posterior rectal cells, and in situ sodium flux across this epithelium increases significantly in larvae held in higher salinity and is sensitive to Bafilomycin A1, an inhibitor of VHA. We also report the first evidence of splice variants of the sodium/proton exchanger, NHE3, with both high and low molecular weight variants highly expressed on the apical membrane of the posterior rectal cells. Evidence of NHE3 function was indicated with in situ sodium transport significantly inhibited by a NHE3 antagonist, S3226. We propose that the outward proton pumping by VHA establishes a favourable electromotive gradient to drive sodium secretion via NHE3 thus producing a hyperosmotic, sodium-rich urine. This H+- driven Na+ secretion process is the primary mechanism of ion regulation in salt-tolerant culicine mosquito species and was first investigated over 80 years ago.

The human ATAD5 has evolved unique structural elements to function exclusively as a PCNA unloader.

Humans have three different proliferating cell nuclear antigen (PCNA) clamp-loading complexes: RFC and CTF18-RFC load PCNA onto DNA, but ATAD5-RFC can only unload PCNA from DNA. The underlying structural basis of ATAD5-RFC unloading is unknown. We show here that ATAD5 has two unique locking loops that appear to tie the complex into a rigid structure, and together with a domain that plugs the DNA-binding chamber, prevent conformation changes required for DNA binding, likely explaining why ATAD5-RFC is exclusively a PCNA unloader. These features are conserved in the yeast PCNA unloader Elg1-RFC. We observe intermediates in which PCNA bound to ATAD5-RFC exists as a closed planar ring, a cracked spiral or a gapped spiral. Surprisingly, ATAD5-RFC can open a PCNA gap between PCNA protomers 2 and 3, different from the PCNA protomers 1 and 3 gap observed in all previously characterized clamp loaders.

Efficacy of Intravesical Nadofaragene Firadenovec for Patients With Bacillus Calmette-Guérin-Unresponsive Nonmuscle-Invasive Bladder Cancer: 5-Year Follow-Up From a Phase 3 Trial.

PURPOSE: Nadofaragene firadenovec-vncg is a nonreplicating adenoviral vector-based gene therapy for bacillus Calmette-Guérin (BCG)-unresponsive carcinoma in situ (CIS) with/without high-grade Ta/T1. We report outcomes following 5 years of planned follow-up. MATERIALS AND METHODS: This open-label phase 3 trial (NCT02773849) enrolled patients with BCG-unresponsive nonmuscle-invasive bladder cancer in 2 cohorts: CIS ± Ta/T1 (CIS; n = 107) and Ta/T1 without CIS (Ta/T1 cohort; n = 50). Patients received 75 mL (3 × 1011 vp/mL) nadofaragene firadenovec intravesically once every 3 months with cystoscopy and cytology assessments, with continued treatment offered to those remaining high grade recurrence-free (HGRF). RESULTS: One hundred fifty-seven patients were enrolled from 33 US sites (n = 151 included in efficacy analyses). Median follow-up was 50.8 months (interquartile range 39.1-60.0), with 27% receiving ≥ 5 instillations and 7.6% receiving treatment for ≥ 57 months. Of patients with CIS 5.8% (95% CI 2.2-12.2) were HGRF at month 57, and 15% (95% CI 6.1-27.8) of patients with high-grade Ta/T1 were HGRF at month 57. Kaplan-Meier-estimated HGRF survival at 57 months was 13% (95% CI 6.9-21.5) and 33% (95% CI 19.5-46.6) in the CIS and Ta/T1 cohorts, respectively. Cystectomy-free survival at month 60 was 49% (95% CI 40.0-57.1): 43% (95% CI 32.2-53.7) in the CIS cohort and 59% (95% CI 43.1-71.4) in the Ta/T1 cohort. Overall survival at 60 months was 80% (71.0, 86.0): 76% (64.6-84.5) and 86% (70.9-93.5) in the CIS and Ta/T1 cohorts, respectively. Only 5 patients (4 with CIS and 1 with Ta/T1) experienced clinical progression to muscle-invasive disease. CONCLUSIONS: At 60 months, nadofaragene firadenovec-vncg allowed bladder preservation in nearly half of the patients and proved to be a safe option for BCG-unresponsive nonmuscle-invasive bladder cancer.

Differential modulation of sensory response dynamics by cilia structure and intraflagellar transport within and across chemosensory neurons.

Sensory neurons contain morphologically diverse primary cilia that are built by intraflagellar transport (IFT) and house sensory signaling molecules. Since both ciliary structural and signaling proteins are trafficked via IFT, it has been challenging to decouple the contributions of IFT and cilia structure to neuronal responses. By acutely inhibiting IFT without altering cilia structure and vice versa , here we describe the differential roles of ciliary trafficking and sensory ending morphology in shaping chemosensory responses in C. elegans. We show that a minimum cilium length but not continuous IFT is necessary for a subset of responses in the ASH nociceptive neurons. In contrast, neither cilia nor continuous IFT are necessary for odorant responses in the AWA olfactory neurons. Instead, continuous IFT differentially modulates response dynamics in AWA. Upon acute inhibition of IFT, cilia-destined odorant receptors are shunted to ectopic branches emanating from the cilia base. Spatial segregation of receptors in these branches from a cilia-restricted regulatory kinase results in odorant desensitization defects, highlighting the importance of precise organization of signaling molecules at sensory endings in regulating response dynamics. We also find that adaptation of AWA responses upon repeated exposure to an odorant is mediated by IFT-driven removal of its cognate receptor, whereas adaptation to a second odorant is regulated via IFT-independent mechanisms. Our results reveal unexpected complexity in the contribution of IFT and cilia organization to the regulation of responses even within a single chemosensory neuron type, and establish a critical role for these processes in the precise modulation of olfactory behaviors.

Inflammatory myofibroblastic tumor of the urinary bladder: A systematic review of the literature and report of a case.

Introduction: Inflammatory myofibroblastic tumors (IMTs) are intermediate-grade lesions that frequently recur and rarely metastasize. There are currently no guidelines on the management of bladder IMTs. This systematic review aims to describe the clinical presentation and compare the management options for bladder IMTs. Methods: A PubMed/Medline search was conducted, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, using the following Mesh terms: ("inflammatory myofibroblastic") AND ("tumor") OR ("tumor") AND ("bladder") AND ("case report"). A total of 75 case reports were included in the analysis. Results: The mean age of the patients was 36 years. 65% of the cases initially presented with hematuria. 68% of the tumors stained positive for anaplastic lymphoma kinase, and 20% invaded the muscularis. Patients underwent either transurethral resection of the bladder tumor (TURBT) only (34%), TURBT followed by complementary partial cystectomy (16%), or TURBT followed by radical cystectomy (4%). 36% and 9% of the cases underwent partial and radical cystectomy after the initial diagnosis, respectively. Cystectomies were performed using an open (74%), laparoscopic (14%), robotic-assisted (10%), or unknown (2%) approach. At a mean follow-up of 14 months, the recurrence and metastasis rates were about 9% and 4%, respectively. In addition, we present the case of a 49-year-old woman with a bladder IMT who underwent TURBT followed by laparoscopic partial cystectomy. The patient remains tumor free postoperatively (follow-up period of 12 months). Conclusion: A complete surgical excision of the bladder IMT is crucial for the optimal management of these cases. Proper differentiation of this tumor from sarcoma or leiomyosarcoma leads to the best outcomes.

Early experience with sequential intravesical gemcitabine and docetaxel for micropapillary variant non-muscle invasive bladder cancer.

BACKGROUND: Guidelines lack clear recommendations regarding conservative management of micropapillary (MP) variant non-muscle invasive bladder cancer (NMIBC). Bladder-sparing therapy using intravesical Bacillus Calmette-Guerin (BCG) has been reported although there are concerns regarding recurrence and progression with this approach. Due to the ongoing BCG shortage, we have utilized sequential intravesical gemcitabine and docetaxel (Gem/Doce) as primary therapy for NMIBC, including some cases with limited MP urothelial carcinoma (MPUC). To compare oncologic outcomes of patients with non-muscle invasive MPUC and conventional UC treated with Gem/Doce. METHODS: A secondary analysis of 138 patients with high-risk NMIBC treated with intravesical Gem/Doce from January 2011 to December 2021 was performed. Oncologic outcomes were compared in patients with or without MPUC using the Kaplan-Meier method. RESULTS: Median follow-up (f/u) for all patients was 23 months (IQR 13-34). There were 129 patients with pure UC and 9 with MPUC. In those with MPUC, all were high-grade (HG), 8/9 were stage T1, 7/9 had a focal MP component (extent < 10%), 3/9 had concomitant CIS, and 2/9 had lymphovascular invasion. All MPUC tumors were re-resected, and 4 had T0, 3 had T1 HG, 1 had Ta HG, 1 had carcinoma in situ (CIS); none had residual MP or LVI tumors before Gem/Doce treatment. The 24-month high-grade recurrence-free survival was 89% and 80% in patients with MPUC and pure UC, respectively. Survival outcomes did not significantly differ between patients with and without MPUC. Four patients with MPUC experienced recurrent NMIBC after Gem/Doce, and all were treated successfully with rescue sequential intravesical valrubicin and docetaxel (Val/Doce). Pathology of these four recurrent patients revealed more aggressive histologic features in the original tumor including: multifocal tumor (3/4), T1 HG disease (4/4), concomitant CIS (2/4), and moderate MP variant extent (30%) (1/4). No patient with MPUC underwent cystectomy, experienced progression, or died at last follow-up (median f/u of 43 months). CONCLUSIONS: Gem/Doce with Val/Doce rescue appears to have activity against carefully selected non-muscle invasive MPUC with favorable histology. Larger prospective trials are needed to validate these results.

Cryo-EM reveals a nearly complete PCNA loading process and unique features of the human alternative clamp loader CTF18-RFC.

The DNA sliding clamp PCNA is a multipurpose platform for DNA polymerases and many other proteins involved in DNA metabolism. The topologically closed PCNA ring needs to be cracked open and loaded onto DNA by a clamp loader, e.g., the well-studied pentameric ATPase complex RFC (RFC1-5). The CTF18-RFC complex is an alternative clamp loader found recently to bind the leading strand DNA polymerase ε and load PCNA onto leading strand DNA, but its structure and the loading mechanism have been unknown. By cryo-EM analysis of in vitro assembled human CTF18-RFC-DNA-PCNA complex, we have captured seven loading intermediates, revealing a detailed PCNA loading mechanism onto a 3'-ss/dsDNA junction by CTF18-RFC. Interestingly, the alternative loader has evolved a highly mobile CTF18 AAA+ module likely to lower the loading activity, perhaps to avoid competition with the RFC and to limit its role to leading strand clamp loading. To compensate for the lost stability due to the mobile AAA+ module, CTF18 has evolved a unique ß-hairpin motif that reaches across RFC2 to interact with RFC5, thereby stabilizing the pentameric complex. Further, we found that CTF18 also contains a separation pin to locally melt DNA from the 3'-end of the primer; this ensures its ability to load PCNA to any 3'-ss/dsDNA junction, facilitated by the binding energy of the E-plug to the major groove. Our study reveals unique structural features of the human CTF18-RFC and contributes to a broader understanding of PCNA loading by the alternative clamp loaders.

Biocultural and social determinants of ill health and early mortality in a New Mexican paediatric autopsy sample.

RESULTS.: Hispanic children have higher odds of growth stunting than non-Hispanic White children. Native American children die younger and have higher odds of respiratory diseases and porous lesions than Hispanic and non-Hispanic Whites. Rural/urban location does not significantly impact age at death, but housing type does. Individuals who lived in trailers/mobile homes had earlier ages at death. When intersections between housing type and housing location are considered, children who were poor and from impoverished areas lived longer than those who were poor from relatively well-off areas. CONCLUSIONS.: Children's health is shaped by factors outside their control. The children included in this study embodied experiences of social and ELS and did not survive to adulthood. They provide the most sobering example of the harm that social factors (structural racism/discrimination, socioeconomic, and political structures) can inflict.

Sequential endoluminal gemcitabine and docetaxel vs. Bacillus Calmette-Guérin for the treatment of upper tract carcinoma in situ.

INTRODUCTION: Nephroureterectomy is commonly performed for high-grade (HG) upper tract (UT) urothelial carcinoma (UC). However, some patients may benefit from a de-escalation of surgical management, particularly for noninvasive disease and carcinoma in situ (CIS). Bacillus Calmette-Guerin (BCG) is currently the only guideline-recommended endoluminal treatment option. Gemcitabine/Docetaxel (Gem/Doce) has shown promising efficacy as a treatment for noninvasive HG UTUC, though a comparison to BCG is lacking. We report the outcomes of patients treated with endoluminal Gem/Doce vs. BCG for UT-CIS. METHODS: A single-institutional retrospective review of patients treated with Gem/Doce vs. BCG for UT-CIS was performed. Treatment was instilled via nephrostomy or retrograde ureteral catheter. In both treatment groups, induction consisted of 6 weekly instillations. Maintenance was initiated if disease-free and consisted of 6 monthly instillations in the Gem/Doce group and a reduced dose (one-tenth) 3-week course at 3 months in the BCG group. Recurrence was defined as biopsy-proven disease or HG cytology. RESULTS: The final cohort included 53 patients with 65 upper tract units; 31 received BCG and 34 received Gem/Doce. Median follow-up was 88 and 29 months in the BCG and Gem/Doce groups, respectively. Presenting pathology included biopsy-proven CIS and HG cytology in 9.7% and 90% of the BCG group, and 8.8% and 91% of the Gem/Doce group, respectively. The 2-year estimates for recurrence-free and nephroureterectomy-free survival were 61% and 89% for the BCG group and 54% and 100% for the Gem/Doce group, respectively. Upon multivariable analysis, instillation via percutaneous nephrostomy tube was associated with an increased risk of recurrence (HR 3.89, 95% CI 1.59-9.53). The development of any symptom was not statistically different between treatment groups (P = 0.12). There were 2 treatment-related deaths that occurred, 1 within each treatment group. CONCLUSION: Endoluminal Gem/Doce and BCG have similar oncological outcomes and major adverse event rates in the treatment of UT-CIS. Further prospective evaluation is warranted.

Leiomyosarcoma of the prostate: a novel approach to treatment-case report and review of the literature.

Leiomyosarcoma of the prostate is a rare and aggressive tumor, with a quarter of the patients harboring metastatic disease, commonly in the lung. It usually presents with urinary obstruction in a relatively younger patient group. A 29-year-old male presented with lower urinary tract symptoms to the urologist. Computed tomography scan revealed a large pelvic mass involving the prostate. Biopsy on two occasions yielded leiomyoma. Instead of conventional radical surgery, en-bloc resection of the mass was done while preserving the remaining portion of the prostate, seminal vesicles, and ejaculatory duct. Histopathology revealed a high-grade leiomyosarcoma with negative margins. The patient had excellent recovery of defecation, erectile, and ejaculatory functions within 2 months after adjuvant radiotherapy. At the 24-month follow-up there was no evidence of disease. En-bloc resection of the tumor can be considered in select cases to improve functional outcomes and sustain a higher quality of life in patients.

Patterns of treatment of high-risk BCG-unresponsive non-muscle invasive bladder cancer (NMIBC) patients among Arab urologists.

PURPOSE: To understand the treatment plans suggested for BCG-unresponsive non-muscle invasive disease (NMIBC) patients in the Arab countries and therapeutic decisions applied for BCG-naive patients during BCG shortage time. METHODS: A 10-minute online survey was distributed through the Arab Association of Urology (AAU) office to urologists in the Arab countries who treat patients with NMIBC. RESULTS: One hundred six urologists responded to the survey. The majority of urologists had treated, in the past 6 months, > 10 patients with NMIBC who were considered BCG-unresponsive (55% of respondents). Radical cystectomy (RC) was the most popular treatment option (recommended by 50%) for these patients. This was followed by intravesical chemotherapy (30%), repeat BCG therapy (12%), resection with ongoing surveillance (8%). Clinical trials and intravenous checkpoint inhibitors were never selected. The most preferred intravesical chemotherapy was by ranking: 60% gemcitabine, 19% mitomycin C, 8% docetaxel, 8% gemcitabine/docetaxel, 4% sequential gemcitabine/mitomycin C, and 1% valrubicin. The use of intravesical chemotherapy appears limited by Arab urologists due to concerns regarding clinical efficacy (fear of progression) and the lack of clear recommendations by urology societies. Given the BCG shortage, which may vary per Arab country, Arab urologists have adjusted by prioritizing BCG for T1 and carcinoma in situ (CIS) patients over Ta, adapting intravesical chemotherapy, and reducing the dose/strength of BCG administered. Most physicians report an eagerness to utilize novel therapies to address the BCG deficit, especially to try intravesical chemotherapy. CONCLUSIONS: Even though Arab urologists are in the majority of cases selecting RC for BCG-unresponsive cases, one-third of them are most recently initiating intravesical chemotherapy as an alternative option. To further assist Arab urologists in the appropriate selection of BCG unresponsive high risk NMIBC patient treatments, enhanced education and pathway protocols are needed.

Structure of the PCNA unloader Elg1-RFC.

During DNA replication, the proliferating cell nuclear antigen (PCNA) clamps are loaded onto primed sites for each Okazaki fragment synthesis by the AAA+ heteropentamer replication factor C (RFC). PCNA encircling duplex DNA is quite stable and is removed from DNA by the dedicated clamp unloader Elg1-RFC. Here, we show the cryo-EM structure of Elg1-RFC in various states with PCNA. The structures reveal essential features of Elg1-RFC that explain how it is dedicated to PCNA unloading. Specifically, Elg1 contains two external loops that block opening of the Elg1-RFC complex for DNA binding, and an "Elg1 plug" domain that fills the central DNA binding chamber, thereby reinforcing the exclusive PCNA unloading activity of Elg1-RFC. Elg1-RFC was capable of unloading PCNA using non-hydrolyzable AMP-PNP. Both RFC and Elg1-RFC could remove PCNA from covalently closed circular DNA, indicating that PCNA unloading occurs by a mechanism that is distinct from PCNA loading. Implications for the PCNA unloading mechanism are discussed.