Kevin Ginsburg

Zebrafish as a Natural Host Model for Vibrio cholerae Colonization and Transmission

ABSTRACT The human diarrheal disease cholera is caused by the aquatic bacterium Vibrio cholerae. V. cholerae in the environment is associated with several varieties of aquatic life, including insect egg masses, shellfish, and vertebrate fish. Here we describe a novel animal model for V. cholerae, the zebrafish. Pandemic V. cholerae strains specifically colonize the zebrafish intestinal tract after exposure in water with no manipulation of the animal required. Colonization occurs in close contact with the intestinal epithelium and mimics colonization observed in mammals. Zebrafish that are colonized by V. cholerae transmit the bacteria to naive fish, which then become colonized. Striking differences in colonization between V. cholerae classical and El Tor biotypes were apparent. The zebrafish natural habitat in Asia heavily overlaps areas where cholera is endemic, suggesting that zebrafish and V. cholerae evolved in close contact with each other. Thus, the zebrafish provides a natural host model for the study of V. cholerae colonization, transmission, and environmental survival.

Understanding the Risk Factors and Long-Term Consequences of Cisplatin-Associated Acute Kidney Injury: An Observational Cohort Study

Acute kidney injury (AKI) is a well-known complication of cisplatin-based chemotherapy; however, its impact on long-term patient survival is unclear. We sought to determine the incidence and risk factors for development of cisplatin-associated AKI and its impact on long-term renal function and patient survival. We identified 233 patients who received 629 cycles of high-dose cisplatin (99±9mg/m2) for treatment of head and neck cancer between 2005 and 2011. These subjects were reviewed for development of AKI. Cisplatin nephrotoxicity (CN) was defined as persistent rise in serum creatinine, with a concomitant decline in serum magnesium and potassium, in absence of use of nephrotoxic agents and not reversed with hydration. All patients were hydrated per protocol and none had baseline glomerular filtration rate (GFR) via CKD-EPI<60mL/min/1.73m2. The patients were grouped based on development of AKI and were staged for levels of injury, per KDIGO-AKI definition. Renal function was assessed via serum creatinine and estimated glomerular filtration rate (eGFR) via CKD-EPI at baseline, 6- and 12-months. Patients with AKI were screened for the absence of nephrotoxic medication use and a temporal decline in serum potassium and magnesium levels. Logistic regression models were constructed to determine risk factors for cisplatin-associated AKI. Twelve-month renal function was compared among groups using ANOVA. Kaplan-Maier curves and Cox proportional hazard models were constructed to study its impact on patient survival. Of 233 patients, 158(68%) developed AKI; 77 (49%) developed stage I, 55 (35%) developed stage II, and 26 (16%) developed stage III AKI. Their serum potassium and magnesium levels correlated negatively with level of injury (p<0.05). African American race was a significant risk factor for cisplatin-associated AKI, OR 2.8 (95% CI 1.3 to 6.3) and 2.8 (95% CI 1.2 to 6.7) patients with stage III AKI had the lowest eGFR value at 12 months (p = 0.05) and long-term patient survival (HR 2.1; p<0.01) than patients with no or lower grades of AKI. Most common causes of death were recurrent cancer (44%) or secondary malignancy elsewhere (40%). Cisplatin-associated severe AKI occurs in 20% of the patients and has a negative impact on long-term renal function and patient survival. PEG tube placement may be protective and should be considered in high risk-patients.

ERG/AKR1C3/AR Constitutes a Feed-Forward Loop for AR Signaling in Prostate Cancer Cells

Purpose: Intratumoral androgen synthesis in prostate cancer contributes to the development of castration-resistant prostate cancer (CRPC). Several enzymes responsible for androgen biosynthesis have been shown to be overexpressed in CRPC, thus contributing to CRPC in a castrated environment. The TMPRSS2–ERG transcription factor has been shown to be present in primary prostate cancer tumors as well as CRPC tumors. We hypothesize that TMPRSS2–ERG fusions regulate androgen biosynthetic enzyme (ABE) gene expression and the production of androgens, which contributes to the development of CRPC. Experimental design: We used a panel of assays, including lentivirus transduction, gene expression, chromatin immunoprecipitation and sequencing, liquid chromatography-mass spectrometric quantitation, immunocytochemistry, immunohistochemistry, and bioinformatics analysis of gene microarray databases, to determine ERG regulation of androgen synthesis. Results: We found that ERG regulated the expression of the ABE AKR1C3 in prostate cancer cells via direct binding to the AKR1C3 gene. Knockdown of ERG resulted in reduced AKR1C3 expression, which caused a reduction in both DHT synthesis and PSA expression in VCaP prostate cancer cells treated with 5α-androstanedione (5α-Adione), a DHT precursor metabolite. Immunohistochemical staining revealed that ERG was coexpressed with AKR1C3 in prostate cancer tissue samples. Conclusions: These data suggest that AKR1C3 catalyzes the biochemical reduction of 5α-Adione to DHT in prostate cancer cells, and that ERG regulates this step through upregulation of AKR1C3 expression. Elucidation of ERG regulation of ABEs in CRPC may help to stratify TMPRSS2–ERG fusion-positive prostate cancer patients in the clinic for anti–androgen receptor–driven therapies; and AKR1C3 may serve as a valuable therapeutic target in the treatment of CRPC. Clin Cancer Res; 21(11); 2569–79. ©2015 AACR.

Prospective assessment of positioning-related pain in robotic urologic surgery

This was a prospective study to assess positioning-related pain in 20 awake volunteers in the dorsal lithotomy (DL) and lateral decubitus (LD) positions. Each volunteer was put through the series of discrete, sequential steps used to achieve a final position; each step had two options. The Wong-Baker scale (WB) was used to rate pain for each option and the preferred option and ad lib comments were recorded. We found that awake volunteers could clearly and immediately distinguish differences in pain levels between position options. For the DL position, volunteers favored having the arms slightly flexed and pronated as opposed to being straight and supinated reflected by statistically less painful WB scores and option preference. Volunteers preferred having the neck flexed as opposed to being flat. For the LD position, volunteers reported statistically lower pain scores and preference for a foam roll for axilla support as opposed to a rolled blanket, the table flexed without the kidney rest as opposed to a raised kidney rest, and the over arm board as oppose to stacked blankets for contralateral arm support. Ad lib comments from the volunteers supported the above findings. To our knowledge, ours is the first study to demonstrate objective preferences for variations in surgical positioning using awake volunteers. This exercise with awake volunteers resulted in immediate changes in positioning for real robotic surgery patients in our practice.

Risk of Becoming Lost to Follow-up During Active Surveillance for Prostate Cancer

Active surveillance (AS) has emerged as the preferred management strategy for many men with prostate cancer (PC); however, insufficient longitudinal monitoring may increase the risk of poor outcomes. We sought to determine rates of patients becoming lost to follow-up (LTFU) and associated risk factors in a large AS cohort. The Michigan Urologic Surgery Improvement Collaborative (MUSIC) maintains a prospective registry of PC patients from 44 academic and community urology practices. Over a 6-yr period (2011-2017), we identified patients managed with AS. LTFU was defined as any 18-mo period where no pertinent surveillance testing was entered in the registry. With a median surveillance period of 32 mo, the estimated 2-yr LTFU-free probability calculated by Kaplan-Meier method was 90% (95% confidence interval [CI]=89-92%). Both African American race (hazard ratio [HR]: 2.77, 95% CI=1.81-4.24) and Charlson comorbidity index ≥1 (HR: 1.55, 95% CI=1.08-2.23) were independently associated with increased risk of LTFU. There was variability in rates of estimated 2-yr LTFU-free survival across MUSIC practices, ranging from 52% (95% CI=21-100%) to 99% (95% CI=97-100%), with a median of 96% (interquartile range: 94-98%), although this did not reach statistical significance (p=0.076). These data reveal opportunities for urology practices to identify systems to reduce rates of LTFU and improve the long-term safety of AS. PATIENT SUMMARY: With a median observation period of 32 mo, an estimated 10% of patients will be lost to follow-up at the 2 yr time point while on AS. African American men and generally unhealthy patients were at increased risk, and there was variability from one urology practice to another. There is ample opportunity to improve the quality of the performance of AS.

Pathological upgrading at radical prostatectomy for patients with Grade Group 1 prostate cancer: implications of confirmatory testing for patients considering active surveillance

To examine the association between National Comprehensive Cancer Network (NCCN) risk, number of positive biopsy cores, age, and early confirmatory test results on pathological upgrading at radical prostatectomy (RP), in order to better understand whether early confirmatory testing and better risk stratification are necessary for all men with Grade Group (GG) 1 cancers who are considering active surveillance (AS).

Avoidance of androgen deprivation therapy in radiorecurrent prostate cancer as a clinically meaningful endpoint for salvage cryoablation

To investigate the ability of salvage cryoablation of the prostate (SCAP) to delay the need for androgen deprivation therapy (ADT) in local recurrence after radiation therapy to the prostate using the Cryo‐On‐Line Database (COLD) registry.

MP61-20 ACUTE URETERAL JET ANGLED MEASURED BY PREOPERATIVE ULTRASOUND CORRELATES WITH RESOLUTION OF VESICOURETERAL REFLUX TREATED WITH ENDOSCOPIC INJECTION OF SUBURETERIC BULKING AGENTS

INTRODUCTION AND OBJECTIVES: We aim to present longterm outcomes of patients with ureterocele, treated by an innovative technique. To date the optimal surgical technique for ureterocele complex remains unclear and treatment options are extremely variable in this regard. These techniques mostly share major drawbacks including de novo vesicoureteral reflux (VUR) into ureterocele moiety and mandatory secondary surgery. A feasible and minimally invasive method for treatment of ureterocele using concomitant ureterocele double puncture and intraureterocele fulguration has been previously introduced (Kajbafzadeh et al. J Urol 2007; 177: 1118-23). Herein, we present long-term outcomes of this technique. METHODS: After obtaining institutional ethical approval, a retrospective chart review was performed to gather records of patients undergone this technique between 1999 and 2014. Patients with history of previous ureterocele surgery or follow up period of less than two years were excluded from the study. In this technique, after maintaining two punctures into the poles of ureterocele using the stylet of a 3Fr ureteral stent and cutting current, a Double-J stent was inserted into the both punctured sites. Afterwards, fulguration of anterior and posterior ureterocele walls at multiple sites was performed under direct vision in order to create anterior and posterior wall surface welding of urine channel. RESULTS: During the study period, 48 patients (51 ureteroceles) underwent this technique. From these, 31 (64.6%) patients were female. Two patients had single system ureteroceles. Three patients (6.2%) underwent bilateral ureterocele double puncture. Mean (range) age at the time of surgery was 2.9 (2 months 13 years) years. The mean follow up period was 6.1 (2-15.2) years. Mode of presentation was febrile UTI (52%). Ureterocele was successfully decompressed in all except two kids (success rate1⁄496%). Secondary ureterocele surgery was performed successfully in two aforementioned patients. De novo VUR was diagnosed in another two patients in upper pole ureter (one grade II, one grade III) which was endoscopically treated with success in both cases. No febrile UTI was encountered postoperatively. CONCLUSIONS: The present study suggests that double puncture ureterocele surgery is highly successful in decompressing ureterocele without incurring major complications, further partial nephroureterectomy or common sheet double ureteric reimplatation. We believe that, this technique could serve as a promising minimally invasive alternative in ureterocele management.

PD56-02 AVOIDANCE OF ANDROGEN DEPRIVATION THERAPY IN RADIORECURRENT PROSTATE CANCER AS A CLINICALLY MEANINGFUL ENDPOINT FOR SALVAGE CRYOABLATION

INTRODUCTION AND OBJECTIVES: There is a paucity of longterm data following local recurrences from radiation refractory prostate cancer (RRPCa). We analyzed the long-term survival outcomes of salvage cryoablation (Cryo) for RRPCa cancer across two centers. METHODS: Patients undergoing salvage Cryo for biopsy proven, localized RRPCa from 1990 to 2004were prospectively accrued. Preoperative characteristics, perioperative morbidity and postoperative data were reviewed from a prospectively maintained database. The primary outcome was overall survival (OS). Secondary outcomes were metastasis-free survival (MFS) and disease specific survival (DSS). RESULTS: 268 patients were identified with a median follow up of 115 months (55.25-151 IQR). Median age is 70 yrs. (65.8-73 IQR). Median PSA nadir was 2 (1-4.25 IQR) and median pre-salvage PSA was 6 (3.5-10.4 IQR). 20% (54/268) had Gleason score <7 at time of recurrence, 10% (28/268) had a Gleason score of 7, and 69% (184/268) had Gleason score>7. Out of 268 patients, 15 (5.6%) underwent repeat cryotherapy and neoadjuvant hormones were used in 29% of patients (77/268). Of the 268 patients, 123 (45%) experienced some form of morbidity. 101 (38%) had mild-moderate incontinence (0-1 pad/day), 43 (16%) had severe incontinence ( 2 pad/day), 43 (16%) experienced pelvic/perineal pain, 4 (1.5%) had rectourethral fistula, 68 (25%) had urinary retention, 38 (14%) had gross hematuria, and 28 (10.4%) had a bladder neck contracture, 12 (4.4) had urethral stricture disease. There were 176 Clavien 1-2, and 48 Clavien 3 events in the cohort. 4 (1.4%) patients were SP tube dependent and 3 (1.1%) patients went on to cystoprostatectomy.48% (130/268) of patients died by study follow up, 22% (59/268) died of RRPCa, and 31% (84/268) developed metastasis. Median OS was 163 mo., DSS 210 mo. and MFS was 199 mo. There was a significantly worse OS (p1⁄40.027) and MFS (p1⁄40.0114) for patients with a pre-cryotherapy PSA > 10 than those with a PSA <5, and those with PSA 5-10 e Figure 1. CONCLUSIONS: Cryo for RRPCa provides long term MFS, DSS and OS with an acceptable degree of morbidity and is a viable treatment option of localized RRPCa following radiation therapy. PreCryo PSA appears to serve as a prognostic tool for patient selection, and further prospective trials are required for validation.