Preoperative urine nitrite versus urine culture for predicting postoperative fever following flexible ureteroscopic lithotripsy: a propensity score matching analysis.

PURPOSE: Multiple studies have reported that preoperative positive urine culture is an independent risk factor for postoperative fever (POF) after ureteroscopy (URS). Urine nitrite is associated urinary tract infections (UTIs). However, none of studies has explored the role of urine nitrite in the prediction of POF after flexible URS (fURS). METHODS: Patients who underwent fURS by the same surgeon between 2009 and 2019 were screened. Sensitivity and specificity of urine culture and urine nitrite were calculated. Propensity score (PS) matching was performed to get a baseline-balanced retrospective cohort to avoid potential bias. Receiver operating characteristic-area under the curve (ROC-AUC) calculated was used to determine the predictive power of models. Decision curve analysis (DCA) was plotted to obtain the clinical benefit of the models. RESULTS: Poseoperative fever (POF) is defined as the temperature of the patient higher than 38 ℃ within 72 h after operation, with no sign of infection in other systems. 31(2.8%) of 1095 cases had POF after fURL. Urine nitrite had a better specificity than urine culture for POF diagnosis (P < 0.001). After the PS matching, a well-balanced cohort of 24 POF group and 96 no-POF group was produced. The mean AUC from the bootstrap resampling method for urine nitrite model (AUC: 0.8736; 95% CI: 0.8731-0.8743) was significantly increased than that of the urine culture model (AUC: 0.8385; 95% CI: 0.8378-0.8392). The application of two kinds of POF predicting models could bring clinical net benefit when the probability is < 35%. However, urine nitrite model showed a better clinical net benefit acquirement compared to the urine culture model. CONCLUSION: Preoperative positive urine nitrite may play a pivotal role in the prediction of POF after fURS and needs to be validated by future evidence.

Efficacy and safety comparison of pharmacotherapies for interstitial cystitis and bladder pain syndrome: a systematic review and Bayesian network meta-analysis.

INTRODUCTION AND HYPOTHESIS: The objective was to compare the clinical efficacy and safety of pharmacological interventions for interstitial cystitis and bladder pain syndrome (IC/BPS) with direct and indirect evidence from randomized trials. METHODS: We searched PubMed, the Cochrane library, and EMBASE for randomized controlled trials (RCTs) that assessed the pharmacological therapies for IC/BPS. Primary efficacy outcomes included ICSI (O'Leary Sant Interstitial Cystitis Symptom Index), ICPI (O'Leary Sant Interstitial Cystitis Problem Index), 24-h micturition frequency, visual analog scale (VAS), and Likert score for pain. Safety outcomes are total adverse events (AEs, intravesical instillation, and others), gastrointestinal symptoms, headache, pain, and urinary symptoms. A systematic review and Bayesian network meta-analysis were performed. RESULTS: A total of 23 RCTs with 1,871 participants were identified. The ICSI was significantly reduced in the amitriptyline group (MD = -4.9, 95% CI: -9.0 to -0.76), the cyclosporine A group (MD = -7.9, 95% CI: -13.0 to -3.0) and the certolizumab pegol group (MD = -3.6, 95% CI:-6.5 to -0.63) compared with placebo group. Moreover, for ICPI, cyclosporine A showed superior benefit compared to placebo (MD = -7.6, 95% CI: -13 to -2.3). VAS score improved significantly in cyclosporine A group than pentosan polysulfate sodium (MD = 3.09, 95% CI: 0.13 to 6.07). None of the agents revealed a significant alleviation of 24-h micturition frequency. In terms of safety outcomes, the incidence rate on urinary symptoms for botulinum toxin A was the only variate higher than chondroitin sulfate (MD = -2.02, 95% CI: -4.99 to 0.66) and placebo (MD = -1.60, 95% CI:-3.83 to 0.17). No significant difference was found among the other treatments. CONCLUSIONS: Cyclosporine A might be superior to other pharmacological treatments in efficacy. Amitriptyline and certolizumab pegol were capable of lowering the ICSI as well.

Transurethral endoscopic enucleation of the prostate using a diode laser versus bipolar plasmakinetic for benign prostatic obstruction: a meta-analysis.

To evaluate the clinical efficacy and safety of diode laser enucleation of the prostate (DiLEP) versus bipolar plasma kinetic enucleation of the prostate (PKEP) in the management of benign prostatic hyperplasia (BPH). A systematic literature search was undertaken using PubMed, Embase, Web of Science, Cochrane Library, and CKNI databases to identify eligible studies published before April 2019. The quality of evidence and methodology was assessed. Primary outcomes were clinical and demographic characteristics and postoperative efficacy including maximum flow rate (Qmax), postvoid residual (PVR), quality of life (QoL), and International Prostate Symptom Score (IPSS); secondary outcomes were intraoperative variables and major complications. Meta-analyses of extracted data were performed with the RevMan version 5.2. The overall effects were determined by the Z-test, and a p value less than 0.05 was considered with significant difference. A fixed- or random-effect model was chosen to fit the pooled heterogeneity (determined by Chi-squared test and I2). As qualified trials were few, subgroup analyses were not performed. Four randomized controlled trials (RCTs) involving 451 patients were enrolled in our meta-analysis. In the included trials, all the diode (wavelength at 980 nm and 1470 nm) lasers applied output at continuous wave mode; the energy settings ranged from 120 to 160 W for enucleation and 30 to 60 W for coagulation. DiLEP provided less perioperative hemoglobin decrease (MD = - 3.22; 95% CI (- 5.15, - 1.29); p = 0.001; I2 = 65%), less postoperative catheterization time (MD = - 17.82; 95% CI (- 32.74, - 2.90); p = 0.02; I2 = 96%), less postoperative irrigation time (MD = - 7.15; 95% CI (- 13.67, - 0.62); p = 0.03; I2 = 98%), and lower incidence of urinary irritative symptoms (OR = 0.31; 95% CI (0.14, 0.67); p = 0.003; I2 = 0%) compared with PKEP. During the 1, 3, 6, and 12-month postoperative follow-up, no statistically significant difference was found in Qmax, IPSS, QoL, and PVR between the procedures. As regards other perioperative and postoperative parameters and major complications, we found no significant difference. Both DiLEP and PKEP are safe and efficient methods for the treatment of BPH. However, DiLEP showed less perioperative hemoglobin decrease, less postoperative catheterization time, less postoperative irrigation time, and lower rates of postoperative irritative symptoms compared with the PKEP group.

Enucleation of the prostate for benign prostatic hyperplasia thulium laser versus holmium laser: a systematic review and meta-analysis.

To evaluate the clinical efficacy and safety of thulium laser vapoenucleation/enucleation of the prostate (ThuEP) versus holmium laser enucleation of the prostate (HoLEP) in the management of benign prostatic hyperplasia (BPH). A systematic literature search was performed using PubMed, Embase, and Web of Science to identify eligible studies published before July 2018. Meta-analysis of extracted data was performed with RevMan version 5.3. We chose the fixed- or random-effect model to fit the pooled heterogeneity. Five eligible studies including two randomized controlled trials (RCTs) and three non-RCTs involving 1010 patients were enrolled in our meta-analysis. ThuEP provided less enucleation time when compared with HoLEP (WMD = - 7.73, 95% CI - 14.39-1.07, P = 0.02). During the 1st, 6th, and 12th months of postoperative follow-ups, statistically significant differences were found in Qmax (WMD = 2.05, 95% CI 0.52~3.58) and PVR (WMD = - 6.50, 95% CI - 7.35~- 5.66, P < 0.001) in the 1st month after the operation, also in IPSS (IPSS: WMD = - 1.29, 95% CI - 2.39~- 0.19, P = 0.02) in the 12th month after the operation. As regards other perioperative, postoperative parameters, and complication rates, we found no significant difference. Both ThuEP and HoLEP provided satisfactory micturition improvement with low morbidity after the 1st and 6th months of the operation. However, ThuEP showed higher enucleation efficacy and less intraoperative blood loss and may get a better outcome as compared to the HoLEP group in the early postoperative period with regard to Qmax/PVR and IPSS after the 1st and 12th months of the operation respectively.

The Antimuscarinic Agent Tolterodine Regulates Bladder Extracellular Matrix in Partial Bladder Outlet Obstruction in Rats.

BACKGROUND/AIMS: Antimuscarinic agents can delay the progression of bladder dysfunction caused by bladder outlet obstruction (BOO). To date, the relationship between muscarinic receptor activity and the bladder extracellular matrix (ECM) remains unclear. Thus, an animal model of partial BOO (PBOO) in female rats was established to explore the variation in bladder wall ECM proteins under PBOO conditions with antimuscarinic agent administration. METHODS: Rats were randomly divided into three groups: sham, PBOO, and PBOO plus tolterodine. Picrosirius red staining was used to examine the smooth muscle and collagen content of bladder samples. Gene microarray and RT-PCR were performed to survey the expression of ECM proteins, receptors, and metabolism regulators in the rat bladder. Positive results were further evaluated by immunohistochemistry. RESULTS: Picrosirius red staining showed that smooth muscle volume significantly increased in the PBOO and PBOO plus tolterodine groups (p < 0.05), while collagen significantly increased in the PBOO group (p < 0.05) but not in the PBOO plus tolterodine group. Gene microarray and RT-PCR revealed that none of the collagen subtypes exhibited significant changes after PBOO establishment and tolterodine administration. However, matrix metalloproteinases (MMPs) increased significantly in the PBOO plus tolterodine group (p < 0.05). Additionally, PBOO inhibited the expression of non-collagen ECM proteins in the rat bladder wall, while tolterodine induced the expression of non-collagen ECM proteins and ECM receptors. CONCLUSIONS: Tolterodine decreased the volume of collagen in PBOO rat bladder wall, possibly via MMPs, and regulated the expression of ECM proteins and receptors.

Paraneoplastic Cerebellar Degeneration Associated with Pelvic Liposarcoma: A Rare Case Report.

Paraneoplastic cerebellar degeneration (PCD) is one of the most common paraneoplastic neurological syndromes characterized by the rapid development of severe cerebellar ataxia. In this report, a 23-year-old female with noticeable dizziness and gait instability was described. The enhanced CT scanning suggested the presence of a pelvic tumor. Then, PCD was established. Postoperative pathological result defined it as a liposarcoma (LS) with dedifferentiation. Interestingly, clinical symptoms disappeared after the surgical removal of the pelvic tumor. To our knowledge, this was the first case report with PCD due to LS.

Protective Effects of Antimuscarinics on the Bladder Remodeling After Bladder Outlet Obstruction.

BACKGROUND/AIMS: Overactive bladder associated with bladder outlet obstruction (BOO) is a highly prevalent condition, which is usually treated with antimuscarinics. However, the potential effects of antimuscarinics on the structure and function of bladder have not been investigated thus far. METHODS: Sprague-Dawley(R) rats accepted bladder neck obstruction surgery or sham surgery, and then received treatment of three different antimuscarinics (Solifenacin, Darifenacin, and Tolterodine) or vehicle. After 3, 6 and 12 weeks, the bladder function and structure were measured. The effect of antimuscarinics on cellular alteration in vitro was observed under mechanical stimulation. Bladder morphology were examined by immunohistochemistry, and the bladder function were investigated by cystometry and strip contractility test. The expression of muscarinic receptors and inflammatory cytokines were measured by PCR and Western blotting. RESULTS: Here we demonstrate, both in vitro and in vivo, that antimuscarinics are protective regulators for the bladder structure and function. Antimuscarinics decrease the weight of bladders with BOO. Antimuscarinics improve the voiding parameter and enhance the contraction of bladder smooth muscle. The results also show that antimuscarinics inhibit the proliferation of bladder smooth muscle cells both in vivo and in vitro, it can reduce the collagen deposition and inflammatory cytokines in bladders with BOO. During this process, the expression of M2 and M3 receptors was altered by antimuscarinics. CONCLUSION: Antimuscarinics could reverse the structural and functional changes of BOO bladder wall at cellular and tissue level, and the alteration of M2 and M3 receptors may be involved in this biological process.

Risk factors for recurrence in female urethral diverticulectomy: a retrospective study of 66 patients.

PURPOSE: We aimed to report surgical outcomes in female urethral diverticula and to investigate the risk factors for diverticula recurrence. METHODS: A total of 66 patients underwent urethral diverticulectomies from January 2009 to October 2015 at out institution. Patient and diverticula characteristics were collected. Mean follow-up was 28.8 months (range 4-85 months). Recurrence was defined as requiring a repeat diverticulectomy. RESULTS: Mean age was 44.9 years. Mean duration of symptoms was 28.1 months. Seven cases had previous urethral surgeries. Mean diverticula size was 2.8 cm. Main clinical symptoms included dribbling (n = 41), vaginal mass (n = 41), dysuria (n = 33), frequency/urgency (n = 29), infection (n = 24), stress urinary incontinence (SUI) (n = 20) and dyspareunia (n = 8). 10 cases had proximal diverticula, 10 cases had multiple diverticula, and 35 cases had horseshoe/circumferential diverticula. Postoperatively, the recurrence rate was 19.7 %. Preoperative SUI disappeared in 14 cases, and de novo SUI was developed in six cases. One case developed urethral stricture, and no cases reported urinary fistula. Among 60 cases with pathological results, neoplastic change was seen in one case (1.7 %). Besides, atypical hyperplasia (n = 2) and metaplasia (n = 3) were observed. Univariate analysis suggested that age, duration, follow-up, diverticula size and diverticula shape were not associated with surgical outcomes. Patients with multiple diverticula (p = 0.032), proximal diverticula (p = 0.042) and those with previous urethral procedures (p = 0.004) were at risk of recurrent diverticula confirmed by multivariate logistic regression analysis. CONCLUSIONS: The surgical outcomes of urethral diverticulectomies were acceptable. Multiple diverticula, proximal diverticula and previous urethral surgery were three independent risk factors for recurrent diverticula.

Factors Influencing Repair Outcomes of Vesicovaginal Fistula: A Retrospective Review of 139 Procedures.

INTRODUCTION: We aimed to report the outcomes of patients undergoing vesicovaginal fistula (VVF) repair to identify prognostic factors. MATERIALS AND METHODS: Patients who underwent VVF repair between January 2009 and October 2015 were reviewed. Primary outcome was fistula closure at 3 months. RESULTS: A total of 123 patients and 139 procedures of VVF repair were reviewed. The overall success rate was 85.6%. There were no significant differences in age (p = 0.476), etiology (p = 0.900), fistula duration (p = 0.491) and number of repairs (p = 0.509) between success and fail group. Moderate or severe perifistula fibrosis and multiple fistula were associated with failure in repair of fistula (70.8 vs. 93.4%, p < 0.001; 62.5 vs. 88.6%, p = 0.005). No difference was seen in success rate of vaginal and abdominal approaches (86.0 vs. 85.0%, p = 0.800). Logistic regression analysis identified fistula number (p = 0.003) and perifistula fibrosis (p = 0.002) as 2 independent prognostic factors. Medium/large fistulas were 3.2 times more likely to fail in repair than small fistulas (OR 3.2, 95% CI 0.95-10.6, p = 0.061). CONCLUSIONS: Fistula number and perifistula fibrosis were 2 independent prognostic factors for fistula repair. Unsuccessful closure was more likely in medium/large VVF.

Risk of severe rash in cancer patients treated with EGFR tyrosine kinase inhibitors: a systematic review and meta-analysis.

AIM: We performed a meta-analysis to evaluate the incidence and risk factors of severe rash associated with the use of EGFR tyrosine kinase inhibitors (TKIs). METHODS: PubMed, EMBASE and oncology conference proceedings were searched for articles published till March 2016. RESULTS: A total of 18,309 patients from 37 randomized controlled trials were available for the meta-analysis. The overall incidence for severe rash was 6.6% (95% CI: 5.2-8.3%) among patients receiving EGFR-TKIs. The use of EGFR-TKIs significantly increased the risk of developing severe rash (risk ratio: 7.70; 95% CI: 5.79-10.23) in cancer patients. On subgroup analysis, the increased risk of severe rash was driven predominantly by drug type (p = 0.002). CONCLUSION: EGFR-TKIs significantly increase the risk of developing severe rash in cancer patients.

Risk of mTOR inhibitors induced severe pneumonitis in cancer patients: a meta-analysis of randomized controlled trials.

BACKGROUND: A meta-analysis of randomized controlled trials was performed to determine the overall risk of noninfectious severe pneumonitis associated with mTOR inhibitors (mTORi) in cancer patients. MATERIALS & METHODS: PubMed, EMBASE and oncology conference proceedings were searched for relevant studies. RESULTS: A total of 8377 patients from 16 randomized controlled trials were included. The incidence of severe pneumonitis associated with mTORi was 1.7% (95% CI: 1.1-2.5%). The use of mTORi significantly increased the risk of severe pneumonitis compared with controls (odds ratio: 3.36; 95% CI: 2.20-5.12). The analysis was stratified for drug types, tumor types, controlled therapy and mTORi-based regimens, but no significant differences in odds ratios were observed. CONCLUSION: mTORi significantly increase the risk of severe pneumonitis in cancer patients.

Changing trends in the causes and management of male urethral stricture disease in China: an observational descriptive study from 13 centres.

OBJECTIVE: To determine whether there have been any changes in the causes and management of urethral strictures in China. PATIENTS AND METHODS: The data from 4,764 men with urethral stricture disease who underwent treatment at 13 medical centres in China between 2005 and 2010 were retrospectively collected. The databases were analysed for the possible causes, site and treatment techniques for the urethral stricture, as well as for changes in the causes and management of urethral strictures. RESULTS: The most common cause of urethral strictures was trauma, which occurred in 2,466 patients (51.76%). The second most common cause was iatrogenic injures, which occurred in 1,643 patients (34.49%). The most common techniques to treat urethral strictures were endourological surgery (1,740, 36.52%), anastomotic urethroplasty (1,498, 31.44%) and substitution urethroplasty (1,039, 21.81%). A comparison between the first 3 years and the last 3 years showed that the constituent ratio of endourological surgery decreased from 54% to 32.75%, whereas the constituent ratios of anastomotic urethroplasty and substitution urethroplasty increased from 26.73% and 19.18% to 39.93% and 27.32%, respectively (P < 0.05). CONCLUSIONS: During recent years, there has been an increase in the incidence of urethral strictures caused by trauma and iatrogenic injury. Endourological urethral surgery rates decreased significantly, and open urethroplasty rates increased significantly during the last 3 years.

Magnitude-dependent proliferation and contractility modulation of human bladder smooth muscle cells under physiological stretch.

PURPOSE: The purpose of this study was to describe and test a kind of stretch pattern which is based on modified BOSE BioDynamic system to produce optimum physiological stretch during bladder cycle. Moreover, we aimed to emphasize the effects of physiological stretch's amplitude upon proliferation and contractility of human bladder smooth muscle cells (HBSMCs). METHODS: HBSMCs were seeded onto silicone membrane and subjected to stretch simulating bladder cycle at the range of stretches and time according to customized software on modified BOSE BioDynamic bioreactor. Morphological changes were assessed using immunofluorescence and confocal laser scanning microscope. Cell proliferation and cell viability were determined by BrdU incorporation assay and Cell Counting Kit-8, respectively. Contractility of the cells was determined using collagen gel contraction assay. RT-PCR was used to assess phenotypic and contractility markers. RESULTS: HBSMCs were found to show morphologically spindle-shaped and orientation at various elongations in the modified bioreactor. Stretch-induced proliferation and viability depended on the magnitude of stretch, and stretches also regulate contractility and contraction markers in a magnitude-dependent manner. CONCLUSION: We described and tested a kind of stretch pattern which delivers physiological stretch implemented during bladder cycle. The findings also showed that mechanical stretch can promote magnitude-dependent morphological, proliferative and contractile modulation of HBSMCs in vitro.

[Bladder reconstruction using autologous bone marrow mesenchyaml stem cells-seeded bladder acellelar matrix graft in a canine model].

OBJECTIVE: To investigate the feasibility of autologous bone marrow mesenchymal stem cells(BMSCs) seeded on bladder acellular matrix graft (BAMG) for bladder reconstruction in a canine model. METHODS: This study included 25 mongrel dogs. Five dogs were sacrificed for the preparation of BAMG. Twenty dogs were randomly divided into two groups and received partial cystectomy. In group A, the bladder defect was repaired with unseeded BAMG. In group B, the bladder defect was repaired with autologous BMSCs-seeded BAMG. The bladders were retrieved and studied histologically and immunohistochemically at the time point of 1, 2, 4, 8, 12 weeks after surgery to evaluate tissue regeneration. RESULTS: All dogs survived the procedure. Histopathological examination in group B showed there was urothelium developed at the end of the 2 weeks. By 8 and 12 weeks all bladder wall components were regenerated in the repaired area, which were similar to normal bladder tissue. In group A, urothelium regeneration was observed at the end of the 4 weeks, whereas smooth muscle was still not well-formed by 12 weeks. CONCLUSION: Autologous BMSCs-seeded BAMG could promote the repair of bladder defect, which is superior to unseeded BAMG in regenerative properties.

[The Cross-sectional Study on the Influence Factors for Encrustation of Double J Stent in Patients with Urolithiasis].

OBJECTIVE: To study the influence factors for encrustation of double J stent in patients with urolithiasis. METHODS: In this study, there were 84 urolithiasis patients with double J stent included from February to July 2014 in our hospital. The encrustation on double J stent was evaluated by a PC stereo microscope. The nterrelated clinical data were obtained, then the factors which may affect the encrustation were studied by logistic regression analysis. RESULTS: The mean indwelling time was (17. 0±6. 0) d, and a thin encrustation formed on the stents for most cases [67/84(79. 8%)]. Compared with the cases who did not form a thin encrustation, those having a thin encrustation formation on the stent were younger [(44. 9±11. 5) vs. (54. 4±12. 6), P=0. 004]; The patients with proteinuria got a higher rate of encrustation [62/73(84. 9%) vs. 5/11 (45. 5%), P=0. 002]. The patients with urinary tract infection had a higher rate of encrustation [26/28(92. 9%) vs. 41/56(73. 2%), P 3. 035]. The patients with hematuriaalso got a higher rate of encrustation [67/80(83. 8%) vs. 0/4, P=0. 001]. Different sex, retention time,serum calcium,inorganic phosphorus, uric acid, urine pH,lithiasis component had no effects on encrustation (P>0. 05). Logistic regression analysis showed that age and proteinuria was retained as idependent correlated factors with encrustation (P<0. 05), while hematuria and urinary tract infections had a low ntensity correlation with encrustation (P>0. 05). CONCLUSION: For encrustation of double J stentin patients with urolithiasis, younger age, increased urinary protein, hematuria and infections are important risk-factors.

The role of mirabegron in overactive bladder: a systematic review and meta-analysis.

OBJECTIVE: To present a systematic review assessing the efficacy and safety of mirabegron for overactive bladder (OAB). MATERIALS AND METHODS: A literature search was performed using the Cochrane Library, MEDLINE, EMBASE and Science Citation Index Expanded. The literature reviewed included meta-analyses, randomized and nonrandomized prospective studies. We utilized mean difference (MD) to measure the mean number of incontinence episodes and the mean number of micturitions, and OAB questionnaire (OAB-q) and odds ratio (OR) to measure adverse events rates. We used the Cochrane Collaboration's Review Manager 5.1 software for statistical analysis. RESULTS: We identified six publications that strictly met our eligibility criteria. Meta-analysis of extractable data showed that mirabegron was more effective than placebo in treating OAB despite different drug dosages in the efficacy end points: mean number of incontinence episodes per 24 h (MD -0.54; 95% CI -0.63, -0.45; p = 0.001), mean number of micturitions per 24 h (MD -0.55; 95% CI -0.63, -0.47; p = 0.001), OAB-q (MD -4.49; 95% CI -6.27, -2.71; p = 0.001) and adverse events (OR 0.99; 95% CI 0.83, 1.19; p = 0.92). When compared to tolterodine, mirabegron was more effective in terms of mean number of incontinence episodes per 24 h (MD -0.25; 95% CI -0.43, -0.06; p = 0.009). However, there were no differences between mirabegron and tolterodine in mean number of micturitions per 24 h (MD -0.17; 95% CI -0.35, 0.01; p = 0.07) and OAB-q (MD -1.09; 95% CI -2.51, 0.33; p = 0.13). Mirabegron also had a lower adverse reaction rate (OR 0.9; 95% CI 0.8, 1.0; p = 0.04). CONCLUSIONS: In this diverse population, mirabegron was an effective and safe pharmacologic therapy for OAB.

Expression and proliferation profiles of PKC, JNK and p38MAPK in physiologically stretched human bladder smooth muscle cells.

OBJECTIVE: To determine protein kinase C (PKC), c-Jun NH2-Terminal Kinase (JNK) and P38 mitogen-activated protein kinases (p38MAPK) expression levels and effects of their respective inhibitors on proliferation of human bladder smooth muscle cells (HBSMCs) when physiologically stretched in vitro. MATERIALS AND METHODS: HBSMCs were grown on silicone membrane and stretch was applied under varying conditions; (equibiaxial elongation: 2.5%, 5%, 10%, 15%, 20%, 25%), (frequency: 0.05, 0.1, 0.2, 0.5, 1Hz). Optimal physiological stretch was established by assessing proliferation with 5-Bromo-2-deoxyuridine (BrdU) assay and flow cytometry. PKC, JNK and p38 expression levels were analyzed by Western blot. Specificity was maintained by employing specific inhibitors; (GF109203X for PKC, SP600125 for JNK and SB203580 for p38MAPK), in some experiments. RESULTS: Optimum proliferation was observed at 5% equibiaxial stretch (BrdU: 0.837±0.026 (control) to 1.462±0.023)%, (P<0.05) and apoptotic cell death rate decreased from 16.4±0.21% (control) to 4.5±0.13% (P<0.05) applied at 0.1Hz. Expression of PKC was upregulated with slight increase in JNK and no change in p38MAPK after application of stretch. Inhibition had effects on proliferation (1.075±0.024, P<0.05 GF109203X); (1.418±0.021, P>0.05 SP600125) and (1.461±0.01, P>0.05 SB203580). These findings show that mechanical stretch can promote magnitude-dependent proliferative modulation through PKC and possibly JNK but not via p38MAPK in hBSMCs.

The purinergic component of human bladder smooth muscle cells' proliferation and contraction under physiological stretch.

OBJECTIVE: To investigate whether cyclic stretch induces proliferation and contraction of human smooth muscle cells (HBSMCs), mediated by P2X purinoceptor 1 and 2 and the signal transduction mechanisms of this process. METHODS: HBSMCs were seeded on silicone membrane and stretched under varying parameters; (equibiaxial elongation: 2.5%, 5%, 10%, 15%, 20%, 25%), (Frequency: 0.05Hz, 0.1Hz, 0.2Hz, 0.5Hz, 1Hz). 5-Bromo-2-deoxyuridine assay was employed for proliferative studies. Contractility of the cells was determined using collagen gel contraction assay. After optimal physiological stretch was established; P2X1 and P2X2 were analyzed by real time polymerase chain reaction and Western Blot. Specificity of purinoceptors was maintained by employing specific inhibitors; (NF023 for P2X1, and A317491for P2X2), in some experiments. RESULTS: Optimum proliferation and contractility were observed at 5% and 10% equibiaxial stretching respectively, applied at a frequency of 0.1Hz; At 5% stretch, proliferation increased from 0.837±0.026 (control) to 1.462±0.023%, p<0.05. Mean contraction at 10% stretching increased from 31.7±2.3%, (control) to 78.28 ±1.45%, p< 0.05. Expression of P2X1 and P2X2 was upregulated after application of stretch. Inhibition had effects on proliferation (1.232±0.051, p<0.05 NF023) and (1.302±0.021, p<0.05 A314791) while contractility was markedly reduced (68.24±2.31, p<0.05 NF023) and (73.2±2.87, p<0.05 A314791). These findings shows that mechanical stretch can promote magnitude-dependent proliferative and contractile modulation of HBSMCs in vitro, and P2X1 and 2 are at least partially responsible in this process.

Integrin αv mediates contractility whereas integrin α4 regulates proliferation of human bladder smooth muscle cells via FAK pathway under physiological stretch.

PURPOSE: The requirement of integrins for mechanotransduction has been recognized for some time. We investigated the role of integrin subunits and their pathway in the physiological stretch induced contractility and proliferation of human bladder smooth muscle cells. MATERIALS AND METHODS: Human bladder smooth muscle cells were seeded on silicone membrane and subjected to stretch, simulating bladder cycles of various stretches and times, as controlled by customized software on a modified BioDynamic bioreactor. Cell proliferation, viability and cycle were determined by BrdU incorporation assay, the Cell Counting Kit-8 (Beyotime Institute of Biotechnology, Haimen, People's Republic of China) and flow cytometry, respectively. Cell contractility was determined using a collagen gel contraction assay. RESULTS: Physiological stretch increased cell contractility, proliferation and viability. Knockdown of integrin αv but not α4 in the cells disrupted the enhanced contractility induced by stretch. Under physiological stretch conditions, the integrin αv level and phospho-FAK/FAK ratio correlated positively with cell stretch induced enhanced contractility. Further examination revealed that contractile marker expression was associated with integrin αv activation through the FAK pathway. At the same time integrin α4 but not integrin αv mediated stretch induced cell proliferation and viability. CONCLUSIONS: These data revealed that different integrins have different roles in the contractility and proliferation of human bladder smooth muscle cells under physiological stretch. This suggests that different integrins may become specific therapeutic targets in patients with voiding dysfunction. They may also be used to design a specific microenvironment for optimal bladder tissue regeneration.