The insulin secretory granule is a hotspot for autoantigen formation in type 1 diabetes.

In type 1 diabetes, the insulin-producing beta cells of the pancreas are destroyed through the activity of autoreactive T cells. In addition to strong and well-documented HLA class II risk haplotypes, type 1 diabetes is associated with noncoding polymorphisms within the insulin gene locus. Furthermore, autoantibody prevalence data and murine studies implicate insulin as a crucial autoantigen for the disease. Studies identify secretory granules, where proinsulin is processed into mature insulin, stored and released in response to glucose stimulation, as a source of antigenic epitopes and neoepitopes. In this review, we integrate established concepts, including the role that susceptible HLA and thymic selection of the T cell repertoire play in setting the stage for autoimmunity, with emerging insights about beta cell and insulin secretory granule biology. In particular, the acidic, peptide-rich environment of secretory granules combined with its array of enzymes generates a distinct proteome that is unique to functional beta cells. These factors converge to generate non-templated peptide sequences that are recognised by autoreactive T cells. Although unanswered questions remain, formation and presentation of these epitopes and the resulting immune responses appear to be key aspects of disease initiation. In addition, these pathways may represent important opportunities for therapeutic intervention.

Hybrid insulin peptide isomers spontaneously form in pancreatic beta-cells from an aspartic anhydride intermediate.

Hybrid insulin peptides (HIPs) form in beta-cells when insulin fragments link to other peptides through a peptide bond. HIPs contain nongenomic amino acid sequences and have been identified as targets for autoreactive T cells in type 1 diabetes. A subgroup of HIPs, in which N-terminal amine groups of various peptides are linked to aspartic acid residues of insulin C-peptide, was detected through mass spectrometry in pancreatic islets. Here, we investigate a novel mechanism that leads to the formation of these HIPs in human and murine islets. Our research herein shows that these HIPs form spontaneously in beta-cells through a mechanism involving an aspartic anhydride intermediate. This mechanism leads to the formation of a regular HIP containing a standard peptide bond as well as a HIP-isomer containing an isopeptide bond by linkage to the carboxylic acid side chain of the aspartic acid residue. We used mass spectrometric analyses to confirm the presence of both HIP isomers in islets, thereby validating the occurrence of this novel reaction mechanism in beta-cells. The spontaneous formation of new peptide bonds within cells may lead to the development of neoepitopes that contribute to the pathogenesis of type 1 diabetes as well as other autoimmune diseases.

Detailed cadaveric analysis of perivesical lymph nodes in cystectomy specimens.

INTRODUCTION: Perivesical lymph nodes were added to the 8th edition of American Joint Committee on Cancer (AJCC) staging for bladder cancer. Currently, these nodes are inconsistently evaluated at the time of radical cystectomy. The objective of this study was to provide a detailed anatomic evaluation of perivesical lymph nodes. MATERIALS AND METHODS: A radical cystectomy was performed on six un-embalmed cadavers with wide resection of perivesical tissue and meticulous care to separate the pelvic sidewall lymph nodes (e.g. obturator, external iliac) from the bladder and perivesical en-bloc specimen. Perivesical tissue dissection in 2 mm slices was performed with a board-certified pathologist. Lymph node size and location were recorded. RESULTS: Gross tissue resembling lymph nodes were identified in the perivesical tissue in 50% (3/6) of the specimens, with a total of six grossly identified lymph nodes. The mean size was 7.5 mm (2-16 mm). On histologic analysis, 4 of 6 (66%) putative gross lymph nodes had confirmed lymphoid tissue. The mean distance of the lymph nodes from bladder wall was 9 mm (3-15 mm). Eight anatomic locations for perivesical nodes were developed: urachal, anterior bladder wall, posterior peritoneum, bladder neck, bilateral pedicle, bilateral lateral bladder wall. CONCLUSION: This cadaveric study with meticulous dissection of the perivesical space confirms that perivesical lymph nodes are a distinct entity and separate from other lymph nodes in the true pelvis. Perivesical lymph nodes are not present in all subjects and pathologic evaluation is more difficult owing to the surrounding fat. We herein propose perivesical regions for evaluation which can serve as a foundation for future studies and anatomic grossing techniques.

Does qSOFA score predict ICU admission and outcomes in patients with obstructed infected ureteral stones?

INTRODUCTION: Obstructing stones with infection represent a true urologic emergency requiring prompt decompression. Historically the systemic inflammatory response syndrome (SIRS) criteria has been used to predict outcomes in patients with sepsis. The quick Sequential Organ Failure Assessment (qSOFA) score has been proposed as a prognostic factor in patients with acute pyelononephritis associated with nephrolithiasis. However there has been limited application of qSOFA to patients undergoing ureteral stenting with obstructive pyelonephritis. The purpose of this study was to evaluate the predictive value of the qSOFA score for postoperative outcomes following renal decompression in this patient population. MATERIALS AND METHODS: A retrospective review was conducted at three medical centers within one academic institution to identify patients with obstructive pyelonephritis secondary to ureteral stones. All patients underwent emergent ureteral stent placement for decompression. The primary outcome was the predictive value of preoperative qSOFA score ≥ 2 for intensive care unit (ICU) admission postoperatively. Univariate analysis and multivariate regression analysis were performed to identify factors associated with postoperative outcomes, with p < 0.05 considered significant. RESULTS: Of the 289 patients who had ureteral stents placed, 147 patients met inclusion criteria. Twenty-four (16.3%) patients required ICU admission and there were 3 (2%) mortalities, all of these within the ICU admission group. The sensitivity and specificity of the qSOFA score ≥ 2 for ICU admission was 70.8% and 79.5% respectively which outperformed SIRS criteria, which had a sensitivity and specificity of 100% and 33.6% respectively. CONCLUSION: A preoperative qSOFA score ≥ 2 was a significant predictor for postoperative ICU admission in patients undergoing ureteral stent placement for obstructive pyelonephritis. The qSOFA score can be used to determine which patients will require ICU admission.

Which Laser System Is Optimal for Cystolithotripsy of Large Bladder Calculi?

Introduction and Objective: A variety of laser sources are available to treat bladder stones. The aim of this study was to compare time and cost efficiency of the thulium fiber laser (TFL) to four holmium lasers (HLs) with different powers or technologies, including MOSES™ during simulated cystolithotripsy. Materials and Methods: In a benchtop simulation of laser cystolithotripsy, 25 identical 4-cm BegoStones (calcium oxalate monohydrate consistency) were placed on a grid within a 3D-printed bladder model. Lasers were operated at maximal energy, using a 550 µm fiber. Lasers compared were as follows: 60 W TFL, 120 W HL with MOSES, and conventional 120, 100, and 30 W HLs. Five trials were performed for each laser with endpoints of laser time, total time, number of fiber strippings, and total energy. Cost-effectiveness was modeled using laser purchase price, fiber, and operating room (OR) time cost. ANOVA with Tukey's B post hoc was performed to compare outcomes. Spearman's test was used to assess correlation between laser power and procedure time. Results: The laser and total operating times were significantly different between the five systems (p < 0.001). The 120 W HL with MOSES was the fastest with 60.9 minutes of laser and 68.3 minutes of procedure times, while the 30 W HL was the slowest with 281.2 minutes of laser and 297.5 minutes of procedure times. The 60 W TFL was faster than the 30 W HL, but slower than the higher power HLs. Higher laser power was associated with shorter procedure time (Rs = -0.98; p = 0.002). When estimating cost per procedure, the MOSES HL was the cheapest, but had the highest purchase cost. The TFL was not cost-effective for large bladder stones compared with the 100 W HL. Conclusions: When treating large bladder stones, total laser power was highly correlated with laser and procedure times and the TFL was limited by its total power. The most cost-effective laser for use will depend on the case volume.

Cathepsin D Drives the Formation of Hybrid Insulin Peptides Relevant to the Pathogenesis of Type 1 Diabetes.

Hybrid insulin peptides (HIPs) form in pancreatic ß-cells through the formation of peptide bonds between proinsulin fragments and other peptides. HIPs have been identified in pancreatic islets by mass spectrometry and are targeted by CD4 T cells in patients with type 1 diabetes (T1D) as well as by pathogenic CD4 T-cell clones in nonobese diabetic (NOD) mice. The mechanism of HIP formation is currently poorly understood; however, it is well established that proteases can drive the formation of new peptide bonds in a side reaction during peptide bond hydrolysis. Here, we used a proteomic strategy on enriched insulin granules and identified cathepsin D (CatD) as the primary protease driving the specific formation of HIPs targeted by disease-relevant CD4 T cells in T1D. We also established that NOD islets deficient in cathepsin L (CatL), another protease implicated in the formation of disease-relevant HIPs, contain elevated levels of HIPs, indicating a role for CatL in the proteolytic degradation of HIPs. In summary, our data suggest that CatD may be a therapeutic target in efforts to prevent or slow the autoimmune destruction of ß-cells mediated by HIP-reactive CD4 T cells in T1D.

Evaluation of progression from first to second stage sacral neuromodulation and unplanned device removal.

OBJECTIVE: Sacral neuromodulation (SNM) is an advanced treatment option for patients with refractory overactive bladder (OAB) symptoms, urinary retention, and bowel disorders; it is usually performed in 2 separate procedures. This study aims to determine a cohort's progression rate from stage 1 to 2 and predict factors for progression and unplanned device removal or revision. MATERIAL AND METHODS: A retrospective review was conducted in patients who underwent SNM at a single institution between June 2012 and May 2019. Progression rates from stage 1 to 2, patient characteristics, and indications for unplanned SNM removal or revision were recorded. Chi-square, Mann-Whitney U, and Fisher's exact tests were used for data analysis. RESULTS: A total of 128 patients underwent SNM for 1 or more of the following diagnoses: OAB (n=103), urinary retention (n=15), neurogenic bladder dysfunction (n=4), fecal incontinence (n=2), and constipation (n=4). The progression rate to stage 2 was 92.2% (118/128). Patients who failed to progress to stage 2 had additional diagnoses other than OAB, such as urinary retention or bowel disorders (p=0.007). Fifteen patients (12.7%) required SNM removal or revision within 4 years of surgery. Among these patients, the body mass index was significantly lower (p=0.036). CONCLUSION: Most patients (92.2%) progressed to stage 2. Patients with only OAB symptoms had a higher progression rate to stage 2. Single full-stage procedures may be considered in select patients to reduce morbidity, time, and costs.

Chemoablation in Urothelial Carcinoma: A Systematic Review and Future Perspectives.

Chemoablation is an emerging treatment for urothelial carcinomas. This review provides an overview of the evidence for intracavitary chemoablation in the treatment of urothelial carcinomas. The benefits of such agents include a reduction in morbidity and diseased organ preservation. While numerous agents have shown promise, research is limited due to small patient cohorts, varying follow-up, and no standardized methodology to assess response. Therefore, to date, chemoablation has not been widely adopted. This may change as a novel mitomycin formulation has recently been approved for treating low-grade upper tract urothelial carcinoma. Future studies are ongoing which evaluate other promising chemoablation options in urothelial carcinoma.

Single-stage Simultaneous Retrograde and Antegrade Endoscopic Treatment of Giant Prostatic and Bladder Urethral Calculi.

INTRODUCTION: Calculi encountered in the lower urinary tract typically reside within the bladder, less often in the urethra. In this video, we present a minimally invasive endoscopic approach for removal of the largest total stone volume in the lower urinary tract reported in the literature to date. METHODS: A 25-year-old male (body mass index 61 kg/m2) with neurogenic bladder presented with urosepsis and acute kidney injury secondary to obstructive uropathy. Computerized tomography (CT) of the abdomen and pelvis demonstrated bilateral severe hydroureteronephrosis, a 4.2-cm bladder stone, and 3 urethral stones, including a 7.7-cm prostatic urethral stone and 2 membranous urethral stones (Fig. 1). Urgent bilateral percutaneous nephrostomy tubes were placed. The patient elected for endoscopic management. RESULTS: The patient was placed in the supine lithotomy position. His buried penis and narrow urethra only accommodated a 16-French flexible cystoscope. Multiple stones were encountered in the membranous urethra. A 60-W SuperPulse Thulium Fiber laser at 2 J and 30 Hz was utilized to dust the urethral stones efficiently. Simultaneous ultrasound-guided percutaneous access into the bladder was obtained and ultrasonic lithotripsy via shockpulse was used to clear the bladder stone and prostatic stone from above. Total stone treatment time was 240 minutes. Suprapubic and urethral catheters were placed at the conclusion. Postoperative day 1 CT scan confirmed stone-free status and he was discharged postoperative day 2. Outpatient nephrostogram demonstrated patency of bilateral ureters and nephrostomy tubes were removed. CONCLUSION: Higher morbidity procedures including open or laparoscopic approaches have been described for management of large lower urinary tract stones. In this video, we demonstrate a minimally invasive approach of combined simultaneous antegrade and retrograde lithotripsy to achieve a stone-free status in this morbidly obese and complicated patient.

What Guidewire Is the Best for Bypassing an Impacted Ureteral Stone?

Introduction and Objectives: To determine the optimal guidewire for bypassing an impacted ureteral stone. Materials and Methods: Three different benchtop models of varying impaction (300, 362, and 444 mm Hg pressure) were used to compare the ability of 13 different guidewires to bypass an impacted ureteral stone. In the first and second models, we recorded the maximum force required to bypass the stone. In the first model (300 mm Hg) 10 new wires for each of the 13 types were advanced past a ureteral stone using a series 5 digital force gauge. In the second model (362 mm Hg), the top 5 performing guidewires were similarly tested. In the third model (444 mm Hg), 5 attending urologists and 5 urology residents (blinded to wire type) compared the 13 guidewires and rated the wire performance using a Likert scale. Statistical analysis was performed with analysis of variance and the chi-square test. Results: In the first model, there was a significant difference between wires (p < 0.001) with the lowest mean force to bypass a stone seen in the Glidewire (0.117 ± 0.02 lbs) and HiWire (0.130 ± 0.01 lbs). Of the five wires tested in the second model, the Glidewire (0.24 ± 0.09 lbs) and UltraTrack (0.40 ± 0.35 lbs) both required less force than the other three wires (p = 0.018). In the third model, only two wires (Roadrunner and Glidewire) bypassed the impacted stone in 100% of trials. When comparing standard, hybrid, and hydrophilic wires, the hydrophilic had the highest success rate (standard = 0%, hybrid = 36.67%, and hydrophilic = 70.67%; p = 0.000) and Likert score (standard = 1.03, hybrid = 2.38, and hydrophilic = 3.24; p = 0.000). Hydrophilic wires required the least time to bypass the stone (hybrid = 82.81 seconds vs hydrophilic = 45.37 seconds, p = 0.000). Conclusions: In this benchtop study, standard wires performed poorly and hybrid wires were not as effective as hydrophilic wires. The Glidewire required the least force, the shortest insertion time, and had the highest surgeon satisfaction rating.

The Impact of Patient, Procedural, and Staffing Factors Upon Ureteroscopy Cost.

Introduction: The purpose of this study was to evaluate factors during ureteroscopy that can potentially impact procedure cost. Materials and Methods: A retrospective review of 129 consecutive elective ureteroscopy cases was performed to determine direct procedure cost. Direct cost was defined as cost incurred because of operating room expenses, including operating room time, staffing expenses, equipment, and supply costs. Data regarding patient, procedural, and operating room staffing characteristics were compared between the most and least expensive cases. Univariate and logistic regression analysis were performed to identify factors predictive of higher costs. Results: The average direct ureteroscopy cost was $3298/case. On univariate analysis, ureteroscopies in the highest 50th cost percentile had larger stone burden (170.1 vs 146 mm2; p = 0.03) and longer operative times (95.3 vs 49.9 minutes; p < 0.01), were more likely performed for non-stone indications (21.4% vs 7.2%; p = 0.03), more likely to include a resident (65.5% vs 43.6%; p = 0.02), and less likely to have a dedicated urology scrub technician (38.2% vs 61.8%; p = 0.01) compared to cases in the lowest 50th percentile. The presence of a resident, larger stone burden, absence of a dedicated scrub technician, and longer operative time were associated with an average cost increase of $516, $700, $1122, and $1401, respectively. Logistic regression analysis showed that operating room time was the only factor predicting higher cost (OR [odds ratio] 12.8, 95% confidence interval [CI] 2.0-84.0). A post-hoc logistic regression analysis demonstrated that the presence of a resident during ureteroscopy (OR 2.9, 95% CI 1.1-8.0) and larger stone burden (OR 1.01, 95% CI 1.0-1.013) were significantly associated with longer operative times. Conclusion: Operating room time is the primary determinant of ureteroscopy case cost. All efforts should be made to decrease operative time, although balancing patient safety and maintaining a quality training environment.

Ureteropelvic Junction Obstruction in a Polycystic Kidney with Duplicated System: Successful Outcome with Endoscopic Management.

Background: Autosomal dominant polycystic kidney disease is the most prevalent hereditary renal disease, associated with progressive renal insufficiency, usually leading to dialysis. It is rarely diagnosed with other renal abnormalities. We present a case of a 35-year-old woman with a duplicated left polycystic kidney, who had recurrent pain and pyelonephritis because of ureteropelvic junction (UPJ) obstruction of the upper moiety. Case Presentation: A 35-year-old female patient initially presented with left flank pain for 7 days. Evaluation demonstrated enlarged bilateral polycystic kidneys with the appearance of a duplicated system of the left kidney and UPJ obstruction of the upper moeity. She underwent endoscopic management, including balloon dilatation and stent placement. After stent removal she had no symptoms, and ultrasonography showed resolution of the upper pole hydronephrosis. Conclusion: Minimally invasive nephron sparing approaches for UPJ obstruction could delay the process of end-stage renal disease development in polycystic kidney disease patients who have additional congenital renal anomalies. Balloon dilatation should be considered as a feasible therapy for UPJ obstruction in polycystic kidney disease patients with duplicated systems.

The Effect of Operative Field Instrument Clutter During Intraoperative Fluoroscopy on Radiation Exposure.

Introduction and Objectives: Fluoroscopy units are routinely operated in the automatic brightness control (ABC) mode to optimize image quality. During ureteroscopy, objects may be placed within the fluoroscopy beam and the effect upon radiation exposure is unknown. The purpose of this study is to investigate the effects of equipment within the fluoroscopy beam during simulated ureteroscopy. Methods: ABC fluoroscopy of a cadaver was performed in eight clinical scenarios, including a control (no equipment), and seven groups with different equipment within the fluoroscopy beam. Equipment tested included electrocardiogram (EKG) leads, a Kelly clamp, camera and light cords (straight and coiled configurations), flexible ureteroscope, rigid cystoscope, and the lateral table support beam. Ten 145-second fluoroscopy trials were performed for each arm. The primary outcome was radiation dose (mGy) compared using the Mann-Whitney test with p < 0.05 considered significant. Results: Compared with control (18.5 mGy), radiation exposure was significantly increased with the presence of a straight camera and light cords (19.3 mGy), Kelly clamp (19.4 mGy), coiled camera and light cords (20.2 mGy), a flexible ureteroscope (21.0 mGy), a rigid cystoscope (21.2 mGy), and when the lateral table support beam was in the path of the X-ray (25.0 mGy; a 35% increase; p < 0.007 for all). The EKG leads did not affect the radiation dose. Conclusions: Avoiding equipment within the fluoroscopy beam using ABC mode can reduce radiation exposure. Adjusting the table and patient position to exclude the lateral table support beam will reduce radiation exposure by 35%.