Layers Of Bladder Wall Research Articles

Bladder Wall Stiffness after Cystectomy in Bladder Cancer Patients: A Preliminary Study.

Bladder cancer (BlCa), specifically urothelial carcinomas, is a heterogeneous disease that derives from the urothelial lining. Two main classes of BlCa are acknowledged: the non-muscle invasive BlCa and the muscle-invasive BlCa; the latter constituting an aggressive disease which invades locally and metastasizes systemically. Distinguishing the specific microenvironment that cancer cells experience between mucosa and muscularis propria layers can help elucidate how these cells acquire invasive capacities. In this work, we propose to measure the micromechanical properties of both mucosa and muscularis propria layers of the bladder wall of BlCa patients, using atomic force microscopy (AFM). To do that, two cross-sections of both the macroscopically normal urinary bladder wall and the bladder wall adjacent to the tumor were collected and immediately frozen, prior to AFM samples analysis. The respective "twin" formalin-fixed paraffin-embedded tissue fragments were processed and later evaluated for histopathological examination. H&E staining suggested that tumors promoted the development of muscle-like structures in the mucosa surrounding the neoplastic region. The average Young's modulus (cell stiffness) in tumor-adjacent specimens was significantly higher in the muscularis propria than in the mucosa. Similarly, the tumor-free specimens had significantly higher Young's moduli in the muscularis propria than in the urothelium. Young's moduli were higher in all layers of tumor-adjacent tissues when compared with tumor-free samples. Here we provide insights into the stiffness of the bladder wall layers, and we show that the presence of tumor in the surrounding mucosa leads to an alteration of its smooth muscle content. The quantitative assessment of stiffness range here presented provides essential data for future research on BlCa and for understanding how the biomechanical stimuli can modulate cancer cells' capacity to invade through the different bladder layers.

Birefringent tissue-mimicking phantom for polarization-sensitive optical coherence tomography imaging.

.Significance: Tissue birefringence is an important parameter to consider when designing realistic, tissue-mimicking phantoms. Options for suitable birefringent materials that can be used to accurately represent tissue scattering are limited.Aim: To introduce a method of fabricating birefringent tissue phantoms with a commonly used material—polydimethylsiloxane (PDMS)—for imaging with polarization-sensitive optical coherence tomography (PS-OCT).Approach: Stretch-induced birefringence was characterized in PDMS phantoms made with varying curing ratios, and the resulting phantom birefringence values were compared with those of biological tissues.Results: We showed that, with induced birefringence levels up to , PDMS can be used to resemble the birefringence levels in weakly birefringent tissues. We demonstrated the use of PDMS in the development of phantoms to mimic the normal and diseased bladder wall layers, which can be differentiated by their birefringence levels.Conclusions: PDMS allows accurate control of tissue scattering and thickness, and it exhibits controllable birefringent properties. The use of PDMS as a birefringent phantom material can be extended to other birefringence imaging systems beyond PS-OCT and to mimic other organs.

Vesical Imaging-Reporting and Data System (VI-RADS) for assessment of response to systemic therapy for bladder cancer: preliminary report.

The Vesical Imaging-Reporting and Data System (VI-RADS) criteria are expanding, providing fine differentiation of bladder wall layers involvement. We aimed to explore the feasibility of a novel categorical scoring, the Neoadjuvant chemotherapy VI-RADS (nacVI-RADS) for radiologic assessment of response (RaR), to define the spectrum of treatment response among patients with muscle invasive bladder cancer (MIBC). Ten consecutive patients diagnosed with non-metastatic MIBC were prospectively enrolled and addressed to NAC and underwent mpMRI before staging resection and after the chemotherapy cycles. The follow-up MRI assessment was performed using the nacVI-RADS algorithm for evaluation of response to therapy. NacVI-RADS categorically define complete RaR, based on prior VI-RADS score, presence of residual disease, tumor size, and infiltration of the muscularis propria. NacVI-RADS categories were able to match all the final radical cystectomy pathology both for complete pT0 responders and for the patients defined as partial or minimal responders, who only showed some RaR inter-scoring class downstaging. This report is the preliminary evidence of the feasibility of nacVI-RADS criteria. These findings might lead to possible paradigmatic shifts for cancer-specific survival risk assessment and to possibly drive the therapeutic decision through active surveillance programs, bladder-sparing modalities, or to the standard of care.

PD09-11 POTENTIAL ROLE OF MICRO-ULTRASOUND IN THE DIFFERENTIATION BETWEEN MUSCLE-INVASIVE AND NON-MUSCLE INVASIVE BLADDER CANCER: A PROSPECTIVE ANALYSIS

You have accessJournal of UrologyBladder Cancer: Non-invasive I (PD09)1 Sep 2021PD09-11 POTENTIAL ROLE OF MICRO-ULTRASOUND IN THE DIFFERENTIATION BETWEEN MUSCLE-INVASIVE AND NON-MUSCLE INVASIVE BLADDER CANCER: A PROSPECTIVE ANALYSIS Pietro Diana, Giovanni Lughezzani, Alessandro Uleri, Nicola Frego, Roberto Contieri, Marco Paciotti, Vittorio Fasulo, Piergiuseppe Colombo, Nicolomaria Buffi, Alberto Saita, Paolo Casale, Rodolfo Hurle, and Massimo Lazzeri Pietro DianaPietro Diana More articles by this author , Giovanni LughezzaniGiovanni Lughezzani More articles by this author , Alessandro UleriAlessandro Uleri More articles by this author , Nicola FregoNicola Frego More articles by this author , Roberto ContieriRoberto Contieri More articles by this author , Marco PaciottiMarco Paciotti More articles by this author , Vittorio FasuloVittorio Fasulo More articles by this author , Piergiuseppe ColomboPiergiuseppe Colombo More articles by this author , Nicolomaria BuffiNicolomaria Buffi More articles by this author , Alberto SaitaAlberto Saita More articles by this author , Paolo CasalePaolo Casale More articles by this author , Rodolfo HurleRodolfo Hurle More articles by this author , and Massimo LazzeriMassimo Lazzeri More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001977.11AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Magnetic resonance imaging (MRI) has been proposed as a staging tool for bladder cancer (BC), but its use has been limited by its high costs and limited availability. Microultrasound (mUS) is a novel technology capable providing high-resolution images, which was initially developed for the diagnosis of PCa. In the setting of BC, a preliminary study has showed that mUS may be capable to differentiate the bladder wall layers, identify BC and differentiate between non-muscle invasive (NMIBC) and muscle-invasive BC (MIBC). The aim of this study is to confirm on a larger scale the potential role of mUS in the identification and characterization of BC. METHODS: This is an observational study of prospectively collected data performed in patients diagnosed with primary BC and scheduled for an endoscopic treatment. Micro-US was performed before transurethral resection (TUR) of bladder tumor using the ExactVu system with an EV29L 29-MHz side-fire transducer (Exact Imaging, Markham, Canada). The endpoints were to assess the diagnostic accuracy of mUS in identifying BC and in differentiating between NMIBC and MIBC comparing the mUS findings with the histopathological results. RESULTS: Between April 2018 and December 2020, we prospectively enrolled 94 consecutive patients with primary BC. Micro-US window was not acceptable in 10 patients and 2 patient presented with a tumor looking mass at both cystoscopy and abdominal US but histology was negative for bladder cancer showing chronic cystitis. In all the other 82 patients, mUS clearly identified the three bladder wall layers and the BC as heterogeneous structures protruding from the normal wall. The reported accuracy, sensitivity, specificity, and positive, and negative predictive values for mUS were 82.9%, 87.5%, 81%, 65.6%, and 94%, respectively. The ROC curve analysis for the mUS in detecting MIBC shows an AUC of 0.843 (CI 95% 0.746-0.940). CONCLUSIONS: These results confirm in a larger population the potential role of mUS to differentiate the bladder wall layers and reliably differentiate between NMIBC and MIBC in the great majority of patients. In consequence, mUS may represent a cheaper and less time-consuming alternative to mpMRI. Further comparative studies between mUS and MRI are still warranted to validate this imaging technique in the BC staging before its introduction in clinical practice. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e124-e124 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Pietro Diana More articles by this author Giovanni Lughezzani More articles by this author Alessandro Uleri More articles by this author Nicola Frego More articles by this author Roberto Contieri More articles by this author Marco Paciotti More articles by this author Vittorio Fasulo More articles by this author Piergiuseppe Colombo More articles by this author Nicolomaria Buffi More articles by this author Alberto Saita More articles by this author Paolo Casale More articles by this author Rodolfo Hurle More articles by this author Massimo Lazzeri More articles by this author Expand All Advertisement Loading ...

Virtual measurements of paracellular permeability and chronic inflammation via color coded pixel-wise T1 mapping.

To assess whether quantitative T1 relaxometry can measure permeability, chronic inflammation and mural thickening of mouse bladder wall. Adult female C57BL6 mice unexposed to radiation (controls) or 40 wk postirradiation of 10 Gy were scanned at 9.4 T before and after instillation (0.1 mL) of aqueous, novel contrast mixture (NCM) containing 4 mM gadobutrol and 5 mM ferumoxytol. Rapid acquisition with refocused echo (RARE) sequence was used with variable repetition times (TR). Pixel-wise maps of T1 relaxation times for the segmented bladder wall layers were generated from voxel-wise, nonlinear least square data fitting of TR-dependent signal intensity acquired with TR array of 0.4-10 s followed by the histology of harvested bladder. Significant differences between precontrast and postcontrast T1 (ΔT1) were noted in urothelium and lamina propria of both groups but only in detrusor of irradiated group (P < 0.001; 2-way ANOVA). Nearly twofold higher gadobutrol permeability (550 ± 73 vs. 294 ± 160 μM; P < 0.01) derived as per 1/ΔT1 = r1. [C] in urothelium of irradiated group. Inflammation and bladder wall thickening (0.75 ± 0. vs. 0.44 ± 0.08 mm; P < 0.001) predicted by MRI was subsequently confirmed by histology and altered expression of CD45 and zonula occludens-1 (ZO-1) relative to controls. NCM enhanced MRI relies on the retention of large molecular weight ferumoxytol in lumen for negative contrast, while permeation of the non-ionic, small molecular weight gadobutrol through ZO-1 generates positive contrast in bladder wall for virtual measurement of paracellular permeability and assessment of chronic inflammation in thin and distensible bladder wall, which is also defined by its variable shape and location within pelvis.

Assessing the Feasibility and Accuracy of High-resolution Microultrasound Imaging for Bladder Cancer Detection and Staging

BackgroundMagnetic resonance imaging (MRI) has been proposed as a staging tool for bladder cancer (BC), but its use has been limited by its high costs and limited availability. Microultrasound (mUS) is a novel technology capable of providing high-resolution images of the prostate. ObjectiveTo test the feasibility of high-resolution mUS in patients diagnosed with BC and its ability to differentiate between non-muscle-invasive BC (NMIBC) and muscle-invasive BC (MIBC). Design, setting, and participantsThis is an observational prospective study performed in 23 patients with a diagnosis of primary BC scheduled for an endoscopic treatment. Surgical procedureMicro-US was performed before transurethral resection of bladder tumor using the ExactVu system with an EV29L 29-MHz side-fire transducer (Exact Imaging, Markham, Canada). MeasurementsThe endpoints were to test the feasibility, describe the normal bladder wall anatomy, identify the lesions, and compare the mUS findings with the histopathological results. Results and limitationsMicro-US was accurate in differentiating the three layers of the bladder wall in all cases. Bladder cancers were clearly identified as heterogeneous structures protruding from the normal bladder wall. In 14 cases the lesions appeared confined to the lamina propria, and in all cases NMIBC was confirmed by the final pathological report. In the other patients, the lesions seemed to extend into the muscular layer, but MIBC was confirmed in five out of seven cases (71.4%) from the pathologist. The small sample size was the main limitation of the current study. ConclusionsOur findings showed that mUS is able to differentiate the bladder wall layers and identify the bladder cancer stage. Further studies with a larger population and imaging correlation with MRI are warranted before its introduction in clinical practice. Patient summaryIn this report, a new imaging technique was tested for the characterization of bladder cancer. Microultrasound appears to be feasible and capable of discriminating between superficial and invasive tumors.

Transurethral front-firing Greenlight bladder autoaugmentation for bladder contracture: technique and clinical outcomes

To describe a novel transurethral front-firing Greenlight bladder autoaugmentation for the treatment of bladder contracture and report initial clinical outcomes. Between April 2014 and August 2015, five patients diagnosed with contracted bladder were all refractory to conservative treatment and received novel transurethral autoaugmentation. CT scan and urodynamics examination were conducted before operation for disease assessment. Mucosal and muscular layers of bladder wall in fundus were incised vertically and horizontally with front-firing Greenlight laser to enlarge bladder capacity in the operation. Imaging examination and periodical urodynamics study were performed to evaluate the clinical outcomes of the procedure in postoperative follow-up. Transurethral front-firing Greenlight bladder autoaugmentation was performed successfully on all the patients. The mean operative time was 59 min (range 52-65 min) with no significant blood loss. Urodynamic parameters of these patients after operation improved significantly compared with those before operation. Average maximum cystometric capacity (Vmax) increased from 91.2 to 333 ml (p < 0.01), average maximum flow rate (Qmax) ascended from 12.6 to 18.62 ml/min (p < 0.01), and average flow rate (Q(ave)) also increased from 5.74 to 13.18 ml/min (p < 0.01). At the last follow-up, all the patients could void spontaneously with good bladder emptying and their symptoms improved significantly. Our novel transurethral front-firing Greenlight bladder autoaugmentation is a safe and effective treatment for contracted bladders. Future studies with larger sample size and long-term follow-up are needed to confirm our findings.

Diagnosis of urinary bladder diseases in dogs by using two-dimensional and three-dimensional ultrasonography.

Aim:The objective of this study was to obtain and compare two-dimensional (2D) and three-dimensional (3D) ultrasonographic images of the urinary bladder in different disease conditions.Materials and Methods:The present study was conducting on total 10clinical cases of the urinary bladder in dogs. The ultrasound (US) machine used for this study was 3D US machine (Nemio-XG: Toshiba, Japan) having a four-dimensional volumetric probe.Results:In the present study, the inflamed thickened wall was clearly visible with the distinction of different layers of the urinary bladder wall in some of the cases of cystitis using 2D ultrasonography. In 3D sonogram, the urinary bladder was visualized as a large anechoic structure with no distinction of different layers of the bladder wall. The cystoliths were clearly visible as hyperechoic structures with distal acoustic shadow in 2D sonogram and appeared as a bright echogenic area in 3D sonogram. In case of urinary bladder neoplasia in 2D ultrasonogram, the bladder lumen was found to be occluded with a large growth imaged as focal anechoic areas in the tissue of mixed echogenicity with small hyperechoic dots in this tissue parenchyma. In 3D ultrasonogram, a tissue of mixed echogenicity of pus was also observed.Conclusion:From the present study it was concluded that 2D and 3D ultrasonography is very helpful for diagnosis of different clinical conditions of the urinary bladder such as cystitis, cystoliths, and urinary bladder neoplasia. The cavity of urinary bladder was more clearly visualized in 3D ultrasonography, but the distinction of different layers of the bladder wall was visualized only in 2D ultrasonography. The distinct shadow of pus and cystoliths were visible in 2D ultrasonogram. The visualization of pus in 3D ultrasonography was done for the first time in present study.

Murine Bladder Imaging by 2-Photon Microscopy: An Experimental Study of Morphology

We developed 2-photon laser scanning microscopy analysis of the native murine bladder. Bladder tissue from wild-type mice was imaged by 2-photon laser scanning microscopy autofluorescence and second harmonic generation microscopy. Bladder wall layers and structures were analyzed using differences in color, size, shape and morphology. Autofluorescence of the urothelium, nerve structures and muscles was visible in the green spectral channel due to autofluorochromes such as NAD(P)H and elastin. Second harmonic generation of collagen was seen in the blue spectral channel. Imaging from the mucosal side revealed umbrella cells at 0 and 30 μm, of which the high cellular NAD(P)H content allows autofluorescence detection. Below that a network-like connective tissue layer was visualized up to 50 μm that contained vessels with a diameter of 10 to 40 μm and nerves with a diameter of 1 to 6 μm. Imaging from the adventitial side revealed a radiant collagen layer covered with nerves and macrophages at 0 to 20 μm. Below at 20 to 25 μm we visualized a thick muscle layer containing elastic fibers and macrophages. Findings were also represented in 3-dimensional reconstructions, providing information on structure localization, orientation and interconnection. Two-photon laser scanning microscopy imaging using autofluorescence of the murine bladder is a promising technique to provide new insight into structures and morphology. It opens avenues to identify structural changes in bladder pathology.

Intravesical Electromotive Botulinum Toxin-A Administration: an Experimental Study

Purpose The method of Intravesical Electromotive Drug Administration (EMDA) has been applied for the treatment of enormous urological pathologies. However, there is no clinical or experimental report of intravesical botulinum toxin-A (BTX-A) administration in the literature. In this study, an animal model was designed to evaluate the depth of BTX-A penetration and its distribution pattern through rabbit bladder wall layers by the application of EMDA. Material and Methods Ten male healthy New Zealand white rabbits were selected, anesthetized and then, catheterized with a specific catheter containing a conducting electrode. The bladder was washed out with normal saline twice or more until the catheter output became clear. The animals were allocated into two groups, the EMDA group (I), a current generator delivered a total of 2 to 2.4 mA at the frequency of 2.5 kHz for 15 min to the fully distended bladder containing 10 IU/kg BTX-A (Dysport®, Ipsen Limited, UK) and two 2 cm × 2 cm dispersive pads, attached bilaterally parallel to midline at the level of distended bladder. In group II, electrical current with same characteristics was applied to the bladder filled with normal saline solution. For each bladder, three full- thickness from dome, posterior and anterior bladder were obtained and submitted for immunohistochemical staining with primary monoclonal antibody in a dilution of 4:100. The negative controls were processed similarly except the primary antibody was eliminated from the protocol. Results Immunohistochemical staining in EMDA group detected BTX-A at the level of eurothelium, interstitial and muscularis layers in the dome, posterior and anterior walls. In control group, all layers were intact. Conclusions In this study, intravesical electromotive BTX-A administration showed deep and homogenous penetration of the toxin throughout the urinary bladder layers.

Updates in intravesical electromotive drug administration® of mitomycin-C for non-muscle invasive bladder cancer

Electromotive drug administration (EMDA) increases the local drug efficacy by controlling and enhancing transmembranous transport into tissue. EMDA of intravesical mitomycin-C (MMC) has been used for treatment of non-muscle invasive bladder cancer (NMIBC) for about a decade on the basis of laboratory studies that demonstrated an enhanced administration rate of MMC into all bladder wall layers after EMDA compared to standard instillation/passive diffusion (PD). Higher MMC concentrations might have a clinical impact since EMDA was associated with lower recurrence rates than PD in randomized studies. Further data suggest that EMDA/MMC is at least equivalent to BCG in treatment of high-risk bladder tumours. In addition, BCG combined with EMDA/MMC as well as preoperative EMDA/MMC are new therapeutic strategies with promising preliminary results in terms of higher remission rates and longer remission times. In summary, these findings suggest that EMDA for MMC delivery in the bladder could be a major therapeutic breakthrough in the treatment of NMIBC.

Antioxidant Levels in the Pig Urinary Bladder: Distribution within the Bladder Wall and in the Urothelium Derived from Different Bladder Regions

This study was designed to determine the antioxidant levels in the urinary bladder wall layers as well as urothelium derived from different bladder regions. Samples of the urothelium, lamina propria, muscularis, and serosa were prepared from the pig's urinary bladder body, while samples used for regional mapping of the urothelium were prepared from trigone, ventral and dorsal middle bladder body, and apex region. Activities of superoxide dismutase, glutathione peroxidase, glutathione reductase, and catalase were determined. Concentrations of ascorbic acid and glutathione were also measured. Antioxidant activities, i.e. concentrations of superoxide dismutase, glutathione peroxidase, glutathione reductase and glutathione, were shown to be highest in the urothelium and progressively lower towards the serosa. Regional mapping of the urothelium singled out apex as the region with the lowest antioxidant activities, i.e. concentrations of glutathione peroxidase, ascorbic acid, and glutathione. The fact that antioxidants are concentrated in the urothelium implies that urothelium functions as a barrier against reactive species. The urothelium derived from the apex is the region with the lowest antioxidant levels and is therefore probably the region most liable to development of oxidative damage.

Determination of main low molecular weight antioxidants in urinary bladder wall using HPLC with electrochemical detector

The aim of the present work was to develop validated HPLC method using electrochemical detector for simultaneous detection of low molecular weight antioxidants (LMWA) in urinary bladder. Furthermore, the method was applied to study the distribution of LMWA in urinary bladder wall. The ascorbic acid (AA), glutathione in reduced (GSH) and oxidized (GSSG) form and uric acid (UA) were resolved by isocratic elution from C 18 reversed-phase column. The bladder tissue sample preparation involved extraction with meta-phosphoric acid solution for LMWA stabilization. The AA, GSH and UA tissue peak was identified by different approaches. The obtained method validation parameters were in acceptable range: intra-day precision (<4.4%), intra-day accuracy (<8.4%), inter-day precision (<9.4%) and inter-day accuracy (<15.6%). Additionally, the method provided good linearity ( r 2 > 0.99) and recoveries (98.9–112.6%). The distribution of LMWA in urinary bladder was determined by measuring their concentration in bladder wall layers: urothelium, lamina propria, muscularis and serosa. The validated method was able to quantify the reduced form of all three LMWA in all four bladder wall layers. The LMWA concentrations were decreasing from urothelium to serosa except of UA. The developed HPLC method with electrochemical detection of LMWA is simple, fast and can be used for simultaneous quantification of LMWA in tissues, which contain low concentrations of antioxidants.

Identification of Bladder Wall Layers by Raman Spectroscopy

Identification of Bladder Wall Layers by Raman Spectroscopy

Identification of Bladder Wall Layers by Raman Spectroscopy

We explored the applicability of Raman spectroscopy to in situ investigation of bladder wall tissue.Bladder wall tissue was obtained from a guinea pig model and frozen sections were used for Raman spectroscopic investigations. From each section 500 to 700 spectra were obtained in a 2-dimensional grid spanning the urothelium, lamina propria and muscle layer. The data set of spectra was subdivided into groups of similar spectra by a cluster analysis algorithm. With each group assigned a different color Raman maps of frozen sections were constructed based on group membership of measured spectra. These maps were then compared with histological and histochemical data obtained from hematoxylin and eosin and immunohistochemical staining for collagen I and III and for smooth muscle actin to correlate Raman spectral features with bladder wall structure and molecular composition.Urothelium, lamina propria and muscle layers could be clearly distinguished based on Raman spectra. Lamina propria spectra were dominated by signal contributions of collagen and the smooth muscle layer showed strong signal contributions of actin. The urothelium had a relatively strong lipid signal contribution.These results and the fact that Raman spectroscopy is rapidly evolving into a technology that can be applied in vivo by thin, flexible fiberoptic catheters indicate that prospects are good for in vivo analysis of the molecular composition of the normal and pathological bladder without biopsies.

Disruption of guinea pig urinary bladder permeability barrier in noninfectious cystitis.

Although most cell membranes permit rapid flux of water, small nonelectrolytes, and ammonia, the apical membranes of bladder epithelial umbrella cells, which form the bladder permeability barrier, exhibit strikingly low permeabilities to these substances. In cystitis, disruption of the bladder permeability barrier may irritate the bladder wall layers underlying the epithelium, causing or exacerbating inflammation, and increasing urinary frequency, urgency, and bladder pain. To determine the effects of inflammation on the integrity of the permeability barrier, guinea pigs were sensitized with ovalbumin, and the bladders were exposed subsequently to antigen by instillation on the urinary side. Inflammation of the bladder wall markedly reduced transepithelial resistance of dissected epithelium mounted in Ussing chambers and increased water and urea permeabilities modestly at 2 h and more strikingly at 24 h after induction of the inflammation. Transmission and scanning electron microscopy of bladders at 30 min and 24 h after antigen exposure revealed disruption of tight junctions, denuding of patches of epithelium, and occasional loss of apical membrane architecture. These permeability and structural effects did not occur in nonsensitized animals in which the bladders were exposed to antigen and in sensitized animals exposed to saline vehicle rather than antigen. These results demonstrate that inflammation of the underlying muscle and lamina propria can disrupt the bladder permeability barrier by damaging tight junctions and apical membranes and causing sloughing of epithelial cells. Leakage of urinary constituents through the damaged epithelium may then exacerbate the inflammation in the underlying muscle layers.

Evaluation of bladder cancer with a miniature high frequency transurethral ultrasonography probe.

A miniature high frequency 10 MHz transurethral ultrasonography probe has been developed which is adaptable to any standard 17 F cystoscope sheath. High frequency contributed to a definite improvement in image resolution but did not allow distinct visualisation of different bladder wall layers. An 80% correlation between ultrasonographic and pathological staging was established after evaluation of 50 consecutive patients with newly diagnosed bladder tumours. Ta/T1 tumours tended to be overstaged with ultrasound. In some patients, the response to conservative treatment (external beam radiation therapy) of deeply infiltrating tumours could be assessed with the miniature probe on an out-patient basis.