Modification of N-Methyl-N-Nitrosourea initiated bladder carcinogenesis in Wistar rats by terephthalic acid

The effect of terephthalic acid (TPA) on urinary bladder carcinogenesis was examined. Male Wistar rats were initiated by injection of N-Methyl-N-Nitrosourea (MNU) (20 mg/kg b.w. ip) twice a week for 4 weeks, then given basal diet containing 5% TPA, 5% TPA plus 4% Sodium bicarbonate (NaHCO3) or 1% TPA for the next 22 weeks, and then euthanized. 5% TPA treatment induced a high incidence of urinary bladder calculi and a large amount of precipitate. Though 5% TPA plus 4% Sodium bicarbonate (NaHCO3) and 1% TPA treatment did not induce urinary bladder calculi formation, they resulted in a moderate increase in urinary precipitate. Histological examination of urinary bladder revealed that MNU-5% TPA treatment resulted in a higher incidence of simple hyperplasia, papillary or nodular hyperplasia (PN hyperplasia), papilloma and cancer than MNU control. MNU-5% TPA plus 4% Sodium bicarbonate (NaHCO3) and 1% TPA treatment increased slightly the incidence of simple hyperplasia and PN hyperplasia (not statistically significant). The major elements of the precipitate are phosphorus, potassium, sulfur, chloride, calcium and TPA. The present study indicated that the calculi induced by TPA had a strong promoting activity on urinary bladder carcinogenesis and the precipitate containing calcium terephthalate (CaTPA) may also have weak promoting activity on urinary bladder carcinogenesis.

[Effect of Passiflora edulis (passion fruit) extract on rats' bladder wound healing: morphological study]

PURPOSE

To evaluate the effects of hydroalcoholic extract of Passiflora edulis leaves in the healing of urinary bladder in rats from histological aspects.

METHODS

Forty Wistar male rats were submitted to a longitudinal incision of the bladder followed by a stetching in only one level. After this common procedure, animals were divided at random two groups: Passiflora and Control. In the Passiflora group the only dosage used was administered by intraperitoneal injection of hydroalcoholic extract of Passiflora edulis leaves while in the Control group distilled water was injected. Each subgroup was then divided in two subgroups according to the death of these animals: Control, three and seven days, Passiflora, three and seven days. After the death of these animals, an inventory of the abdominal cavity was performed and the bladder was removed. A comparative analysis was done between the two groups with microscopic evaluation of the healing. There was less acute inflammation (p=0.008), greater collagenous formation (p=0.001) and greater capillary neo-formation (p=0.000) in the third day Passiflora subgroup when compared to the Control subgroup of the third day.

RESULTS

There was less acute inflammation (p=0.001), greater fibroblastic proliferation (p=0.011) and greater collagenous formation (p=0.001) in the Passiflora subgroup of seventh day when compared with the Control seventh day subgroup.

CONCLUSION

The use of Passiflora edulis leaves extract resulted in less acute inflammation, greater fibroblastic proliferation, collagenous formation and capillary neo-formation on rats' bladder wound healing.

Permeability of Pig Urinary Bladder Wall: Time and Concentration Dependent Effect of Chitosan

Chitosan in 0.5% w/v concentration enhanced the permeability of the isolated pig urinary bladder wall by desquamation of the urothelium as ascertained in our previous study. The aim of the present work was to determine the time and concentration dependence of chitosan's effect on the permeation of a model drug into the bladder wall and to establish if the mechanism of permeation enhancement depends on the concentration of chitosan used. In the permeability studies performed by the use of diffusion cells, transport of a model drug moxifloxacin into the isolated pig urinary bladder wall was determined. For morphological observations of the urothelium in response to chitosan treatment scanning and transmission electron microscopy were applied. Within 90 min the effect of chitosan on the tissue amounts of moxifloxacin gradually increased and approached its plateau. In one hour even 0.0005% w/v dispersion of chitosan significantly enhanced the permeability of the pig urinary bladder wall for the model drug and at 0.001% w/v concentration the maximal effect on the tissue permeability was achieved. All concentrations of chitosan that significantly enhanced the permeability of the bladder wall triggered necrosis of superficial cells or desquamation of the urothelium. However, at lower concentrations and shorter exposure times the damage of the urothelium was limited to the changes in tight junctions. Chitosan was ascertained to increase the permeation of moxifloxacin into the urinary bladder wall in a time and concentration dependent manner.

Estudo da cicatrização de suturas na bexiga urinária de ratos com e sem a utilização de extrato bruto de Jatropha gossypiifolia L. intraperitoneal

INTRODUÇÃO: A sutura dos tecidos e sua cicatrização é um dos fundamentos básicos da cirurgia e a procura de substâncias que melhorem este processo é desafio constante. O uso de substâncias retiradas de plantas tem sido testado há muitos anos, contudo sem ainda terem comprovação científica consolidada. OBJETIVO: Comparar as alterações macroscópicas e histológicas proporcionadas pelo uso do extrato bruto da Jatropha gossypiifolia L. intraperitonial, na cicatrização de suturas realizadas na bexiga urinária de ratos. MÉTODOS: Quarenta ratos da linhagem wistar, adultos, machos foram distribuídos em dois grupos, experimento e controle. Incisão longitudinal de 1cm na parede ventral da bexiga e síntese em plano único com pontos separados de poliglactina 910 5-0 (ethicon) foi realizada nos dois grupos. No controle, instilou-se na cavidade peritoneal água destilada na proporção de 1ml/kg de peso, enquanto no grupo Jatropha utilizou-se o extrato bruto de Jatropha gossypiifolia L. na proporção de 1ml/kg, que representava 200mg/kg de peso do fitoterápico. Cada grupo foi subdividido em dois subgrupos de 10 animais, sendo estes submetidos à eutanásia no 3º e 7º dia pós-operatório. Foi feita análise macroscópica e histológica comparativa entre os subgrupos. RESULTADOS: No 3º dia foi observada diferença estatisticamente significante nas variáveis inflamação aguda, neoformação vascular e colagenização, sendo a primeira, maior no grupo controle e as duas últimas no grupo Jatropha; no 7º dia as variáveis inflamação aguda e proliferação fibroblástica apresentaram-se mais intensas, com significado estatístico, no grupo controle. CONCLUSÃO: Não se observou efeito favorecedor cicatrizante do extrato bruto da Jatropha gossypiifolia L., intraperitonealmente aplicado, na bexiga urinária de ratos.

Decreased cellular membrane expression of gap junctional protein, connexin 43, in rat detrusor muscle with chronic partial bladder outlet obstruction

OBJECTIVES

To investigate alterations in gap junctional protein, connexin-43 (Cx-43), in the rat detrusor muscle with partial bladder outlet obstruction (P-BOO). Muscle cell actions, such as detrusor contractions, are thought to be synchronized by way of gap junctional intercellular communication. Gap junctions may play an important role in voiding, and P-BOO is a common medical problem.

METHODS

A total of 33 female Wistar rats (12 weeks old) were divided into a P-BOO group and a sham-operated control group and were killed at 2, 4, and 8 weeks after surgery. Cystometric investigation, the alteration of gap junction, and Cx-43 protein expression, which compose the gap junction, were examined.

RESULTS

The number of gap junctions was decreased in the P-BOO rat bladder. Furthermore, decreased cellular membrane expression of Cx-43 proteins was detected in rat detrusor muscle cells more than 4 weeks after surgery. The gap junctions of the detrusor muscle cell membranes were significantly fewer in number in the P-BOO rats with no detrusor contractions.

CONCLUSIONS

These data suggest that the normal signals that contribute to voiding function could be transported directly through the gap junctions. Voiding dysfunction may be caused by the disruption of gap junctional intercellular communication.

Ultrastructural and immunohistochemical analysis of rat uroepithelial cell junctions after partial bladder outlet obstruction and selective COX-2 inhibitor treatment

The present study was undertaken to evaluate alterations in uroepithelial cell junctional complexes in partial bladder outlet obstruction (PBOO) of rat bladders using ultrastructural morphometry and immunohistochemistry, and to determine whether selective COX-2 inhibitors have any effects on these structures. A total of 18 male rats were separated into three groups of six rats each: (1) sham-operated animals served as controls; (2) a PBOO group, without further treatment (3) and a group that immediately after PBOO, received treatment for 4 weeks with oral Celecoxib, a selective COX-2 inhibitor. Uroepithelial cell junctions were evaluated using transmission electron microscopy combined with morphometry. Results were also assessed by E-cadherin and alpha-catenin immunohistochemistry. Morphometrical analysis of ultrastructural evaluations revealed that 4 weeks of PBOO caused a significant reduction in the electron density of zonula adherens and zonula occludens junctional complexes. Moreover, some desmosomes located between the deeper cells of the uroepithelium showed signs of disintegration. Selective COX-2 inhibitor treatment during 4 weeks of PBOO showed protective effects on adherens and occludens junctions, as well as on desmosomes. Immunohistochemical analysis of E-cadherin confirmed that the decreased E-cadherin immunolabelling in 4 weeks of PBOO was prevented by selective COX-2 inhibitor treatment. Based on ultrastructural morphometrical analysis, we conclude that PBOO alone and in combination with selective COX-2 inhibitors can have considerable effects on uroepithelial cellular junctions. Our findings provide a novel area of investigation regarding the selective use of COX-2 inhibitors following PBOO.

Ultra-structural morphological abnormalities of the urinary bladder in streptozotocin-induced diabetic female rats

The objective of this study was to evaluate the ultra-structural changes in the urinary bladder of diabetic rats in relation to disease duration since the morphological bases of diabetes-induced bladder dysfunction are poorly understood. Urinary bladders were examined chronologically by electron microscopy in a female Wistar-rat model of streptozotocin-induced diabetes mellitus and compared to control samples. Numerous dark mitochondria with swollen cristae and electron lucent, large, calcified and degenerated mitochondria were observed first in the urothelium. Intraepithelial capillaries surrounded by thick collagen were also present. Gap junctions between myocytes were interrupted or extensively widened with reduced mitochondria and caveolae. Collagen accumulation, degenerated nerve fibres and myelin bodies were seen between myocytes with increased collagen content and frequent mast cells, phagocytes and lymphocyte aggregates in the stroma. All ultra-structural lesions became augmented with longer duration of diabetes. Diabetes induces time-dependent pathologic changes in the urinary bladder of rats that might account for bladder dysfunction.

Diagnosing the location of carcinoma in situ (CIS) of the urinary bladder using pirarubicin hydrochloride

INTRODUCTION

No established technique for locating solitary carcinoma in situ (CIS) of the urinary bladder or CIS accompanying bladder cancer has been determined. Here we investigated whether the location of CIS of the urinary bladder can be macroscopically ascertained by instilling pirarubicin hydrochloride (THP) into the urinary bladder.

PATIENTS AND METHODS

We dissolved 50 mg of THP in 50 ml of distilled water, and instilled the resulting solution into the urinary bladder. After 5 min, the urinary bladder is examined using a cystoscope. The study group consisted of 30 subjects (23 men and 7 women).

RESULTS

THP uptake was seen in 19 flat (nontumorous) areas of the bladder mucosa in 13 patients. Of these, 11 lesions in 6 patients were confirmed to be CIS. THP uptake was also seen in flat malignant lesions such as bladder cancer invasion into the prostatic urethra, and in benign lesions such as chronic cystitis and urothelial hyperplasia.

CONCLUSIONS

The present method can be useful to find easily and macroscopically the location of flat malignant lesions such as CIS.

Covert operations of uropathogenic Escherichia coli within the urinary tract

Entry into host cells is required for many bacterial pathogens to effectively disseminate within a host, avoid immune detection and cause disease. In recent years, many ostensibly extracellular bacteria have been shown to act as opportunistic intracellular pathogens. Among these are strains of uropathogenic Escherichia coli (UPEC), the primary causative agents of urinary tract infections (UTIs). UPEC are able to transiently invade, survive and multiply within the host cells and tissues constituting the urinary tract. Invasion of host cells by UPEC is promoted independently by distinct virulence factors, including cytotoxic necrotizing factor, Afa/Dr adhesins, and type 1 pili. Here we review the diverse mechanisms and consequences of host cell invasion by UPEC, focusing also on the impact of these processes on the persistence and recurrence of UTIs.

Permeability of pig urinary bladder wall: the effect of chitosan and the role of calcium

Chitosan is a cationic polysaccharide widely employed as an absorption enhancer. The aim of this work was to examine the effect of chitosan on the permeability of isolated pig urinary bladder wall as well as to determine the role of calcium ions in this process. Besides permeability studies, scanning electron microscopy and fluorescent microscopy were applied to get an insight into the mechanism by which chitosan increases the permeability of urinary bladder wall. Additionally, the obtained findings were compared to the mechanism proposed for Caco-2 cells. The results show that 0.5% (w/v) chitosan increases the permeability of urinary bladder wall by causing the desquamation of the urothelium. Calcium ions, when applied to the luminal surface of the urinary bladder at the same time as chitosan, decreases the effect of chitosan on permeation of the model drug moxifloxacin into the bladder wall in concentration dependent way. The desquamation of urothelium cells caused by chitosan was reduced in the presence of calcium, but not to such extent as it would be expected from the permeability studies. When present, calcium obviously interferes directly in the interactions between chitosan and the surface of urothelium.

Lack of ultrastructural detrusor changes following endoscopic injection of botulinum toxin type a in overactive neurogenic bladder

INTRODUCTION

Endoscopical injections of Botulinum toxin type A into the detrusor muscle are gaining clinical acceptance in the treatment of neurogenic detrusor overactivity. Structural effects of Botulinum toxin type A are only known from studies on striated muscles, where a widespread nerve sprouting occurs temporarily. The aim of this study was to evaluate the ultrastructural effects of Botulinum toxin type A injections on the human detrusor.

MATERIAL AND METHODS

30 detrusor biopsies were obtained from 24 patients with neurogenic detrusor overactivity. Patients were divided into two groups: Group I included 13 biopsies from patients before the first Botulinum toxin type A injection. Group II included 6 biopsies from patients within 3 months after the first injection and 11 biopsies at the time of decreasing efficacy of Botulinum toxin type A. The biopsies were processed by standard procedure for detailed electron microscopic study and evaluated by 2 examiners without prior knowledge of clinical/urodynamic data.

RESULTS

No statistically significant detrusor changes have been found concerning muscle cell fascicle structure (p = 0.445), width of intercellular space (p = 0.482) and number/kind of muscle cell junctions (p = 0.443). A median of 70% of intrinsic axon terminals presented with signs of degeneration in group I, a median of 66% in group II (p = 0.840). Out of 309 evaluated axon terminals in both groups, 1 sprouting axon was found in group I, 3 sprouting axons in group II (p = 0.864). Specimen from group I and group II showed only limited collagen deposits within the detrusor. No changes in the ultrastructure of the detrusor have been observed in those biopsies obtained before and after the Botulinum toxin type A injection of the same patient.

CONCLUSION

This study verifies our earlier report of severe intrinsic axon degeneration in the detrusor of patients with neurogenic detrusor overactivity. It also shows nearly no structural differences of the detrusor before and after Botulinum toxin type A injections. Contrary to reports of striated muscle, axonal sprouting within the detrusor was very limited after Botulinum toxin type A injections indicating pathophysiologically different reactions to the toxin either between striated muscle and smooth muscle or between different treated diseases.

Features of the peritoneal covering of the lesser pelvis with special reference to stomata regions

Occasional reports describe various aspects of the fine morphology of the pelvic peritoneum, but its complete organ characteristics remain undefined. The peritoneal covering of the urinary bladder, rectum, uterus, uterine tube, ovary, broad ligament (BL) and testis in Wistar rats was examined by means of transmission and scanning electron microscopy (TEM, SEM). Unusually complicated relief and stomata between the cubic mesothelial cells characterized the surface of the BL. Deep, parallel furrows separated the wide longitudinal folds over the entire length of the uterine tube. The uterus and the ovary formed less numerous, shallow or extremely deep crypt-like invaginations, as well as serous villus-like or papilla-like evaginations. The flat cells were the predominant cell type over the BL, while the cubic mesothelium was the basic covering of the organs. Most of the cubic cells were located in the invagination of the submesothelial layer (SML). Such cells formed an almost smooth surface over the urinary bladder or formed larger areas of the rectum and the testis surfaces. Numerous microvilli, ciliae, round evaginations and complex lamellar bodies characterized their apical plasmalemma. In conclusion, the mesothelial heterogeneity is a stable feature of the lesser pelvis peritoneum, confirmed by TEM and SEM. The cubic mesothelium characterizes the organ peritoneum, while the BL plays the role of the parietal sheet, involving lymphatic units in the SML. The different types of contacts between the mesothelio-endothelial cells, large lymphatic vessels and occasional stomata are the usual components of the lymphatic units in norm, visible by TEM. Images of stomata, seen by SEM, demonstrate oval-shaped deep channel-like gaps surrounded by cubic mesothelium. The last data extend the evidence on stomata regions, which resemble the diaphragmatic ones. Clusters of cells (macrophages, mastocytes and Lymphocytes), small vessels (blood or lymphatic) and nerve fibers (unmyelinated and rare myelinated) form highly specialized complexes in the SML of the ovary, the uterus and the testis.

Morphofunctional ontogeny of the urinary system of the European sea bass Dicentrarchus labrax

European sea bass (Dicentrarchus labrax) are euryhaline fish that tolerate wide salinity fluctuations owing to several morphofunctional adaptations. Among the osmoregulatory sites (tegument, branchial chambers, digestive tract, urinary system), little is known about the kidney and the urinary bladder. The present study describes the ontogeny of the urinary system (kidney and urinary bladder) and focuses on the progressive expression of the Na(+)/K(+)-ATPase in the cells of these ion-transporting epithelia. A structural approach has shown that two pronephric urinary tubules are already present at hatching while the urinary bladder starts to differentiate. The glomus, an ultrafiltration site, occurs at day 5 (D5). The opisthonephros differentiates at D19/25 from the pronephric collecting tubules, then it rapidly grows longer and becomes folded. Na(+)/K(+)-ATPase immunolocalization and transmission electron microscopy show that ionocyte-like cells line the urinary tubules and the dorsal wall of the urinary bladder from D2/D5 on. Tubule ionocytes present a basolateral-localized fluorescence. Ionocytes of the collecting ducts and of the dorsal wall of the bladder present a fluorescence distributed in the whole cytoplasm. Fluorescence becomes stronger in later stages, suggesting a progressively increasing functionality of the urinary system in active ion transports. This observation is closely correlated with the ontogeny of osmoregulatory abilities. In juvenile and preadult fish kept in seawater, osmolality measurements demonstrate that urine is isotonic to blood. At low salinity, urine is hypotonic to blood in both stages. The capacity to produce hypotonic urine increases during ontogeny, a fact that suggests an increasing involvement of the urinary system in osmoregulation. The occurrence and the progressive functionality of the urinary system during the ontogeny, along with those of other osmoregulatory sites, are major adaptations allowing the sea bass to live in habitats of variable salinity such as lagoons and estuaries.

The uroepithelium: not just a passive barrier

The uroepithelium lines the inner surface of the renal pelvis, the ureters, and the urinary bladder, where it forms a tight barrier that allows for retention of urine, while preventing the unregulated movement of ions, solutes, and toxic metabolites across the epithelial barrier. In the case of the bladder, the permeability barrier must be maintained even as the organ undergoes cyclical changes in pressure as it fills and empties. Beyond furthering our understanding of barrier function, new analysis of the uroepithelium is providing information about how detergent-insoluble membrane/protein domains called plaques are formed at the apical plasma membrane of the surface umbrella cells, how mechanical stimuli such as pressure alter exocytic and endocytic traffic in epithelial cells such as umbrella cells, and how changes in pressure are communicated to the underlying nervous system.

Biaxial strength of multilaminated extracellular matrix scaffolds

Xenogeneic extracellular matrix (ECM) can be harvested and configured to function as a bioscaffold for tissue and organ reconstruction. The mechanical properties of the ECM vary depending upon the tissue from which it is harvested. Likewise, the manufacturing steps required to develop ECMs into medical grade devices will affect the surface morphology and the mechanical properties of the bioscaffold; important properties for constructive tissue remodeling. The present study compared the ball-burst strength of five different ECM scaffolds before and after treatment with peracetic acid (PAA): porcine small intestinal submucosa (SIS), porcine urinary bladder submucosa (UBS), porcine urinary bladder matrix (UBM), a composite of UBS + UBM, and canine stomach submucosa (SS). This study also compared the mechanical properties of 2- and 4-layer ECM scaffolds. Results showed 2-layer SS devices had the highest ball-burst value of all 2-layer ECM devices. Moreover, all 4-layer ECM devices had similar ball-burst strength except for 4-layer UBM devices which was the weakest. PAA-treatment decreased the ball-burst strength of SS and increased the ball-burst strength of UBS 2-layer devices. This study showed the material properties of the ECM scaffolds could be engineered to mimic those of native soft tissues (i.e. vascular, musculotendinous, etc) by varying the number of layers and modifying the disinfection/sterilization treatments used for manufacturing.

Using the atomic force microscope to observe and study the ultrastructure of the living BIU-87 cells of the human bladder cancer

In this study, the ultrastructure of living BIU-87 cells of human bladder cancer was mapped using atomic force microscopy to reveal the dynamic change of single cancerous cell division. Simultaneously, the feasibility and functional reliability of the atomic force microscope (AFM) were established and a laboratory model using AFM to study living cancerous cells was created. In this experiment, BIU-87 cells of human bladder cancer were cultured by conventional methods and grown in gelatin-treated dishes. A thermostat was used for preserving the cell's living temperature. Scanning of these cells using AFM was carried out in physiologic condition. The AFM images of the ultrastructure of living BIU-87 cells as well as those of the cell's membrane and cytoskeleton were very clear. The dynamic phenomenon of single cell division was observed. It was concluded that the AFM was able to observe and depict the ultrastructure of living cells of human bladder cancer directly and in real time. This experimental model is expected to play an important role in elucidating the cancerous mechanism of bladder normal cells at the atomic or nanometer level.

Differentiation-dependent localisation of tissue-type plasminogen activator in human bladder urothelium

Human bladder urothelium is able to secrete tissue-type plasminogen activator (tPA). The aim of our study was to analyse localisation of tPA antigen in comparison to differentiation state of cells in samples of histologically normal urothelium and non-invasive tumours of the human urinary bladder. Twenty-five samples of normal urothelium and 31 non-invasive papillary tumours from 36 patients were examined. The presence of tPA antigen was evaluated immunohistochemically. Differentiation of superficial cells was assessed by the presence of urothelial cell differentiation markers, uroplakins (UPs; immunohistochemistry) and cell's apical surface architecture (scanning electron microscopy). All tissue samples stained anti-tPA positive. In normal urothelium, the intensity of anti-tPA staining was the strongest in superficial cells, which were well-differentiated. In tumours, all cell layers stained anti-tPA positive. The intensity of anti-tPA positive reaction in the upper cell layer correlated with the percentage of anti-UP positive superficial cells. Superficial cells showed various differentiation states. The localisation of tPA antigen in human in vivo tissue is not confined to the well-differentiated superficial cells. Our results suggest a positive correlation between tPA secretion and cell differentiation.

An ultrastructural study of the cercarial excretory system in Bucephaloides gracilescens and Prosorhynchus squamatus

The ultrastructure of the flame cells, capillaries, collecting tubes, excretory bladder, excretory atrium, caudal vesicle, lateral caudal ducts and excretory pores of cercariae of Bucephaloides gracilescens (Rudolphi, 1819) Hopkins, 1954 and Prosorhynchus squamatus Odhner, 1905 (Digenea: Bucephalidae) is described. Both species are essentially similar except for some details. The terminal parts of the protonephridia have all the structural features that are typical of trematodes. The collecting tubes in the cercarial body are composed of cells that are wrapped around the lumen. The main collecting tubes are joined to the excretory bladder syncytium by septate junctions. Features of P. squamatus excretory bladder epithelium indicate that it is involved in secretory activity, but this is not the case in B. gracilescens. In both species the luminal surface of the excretory bladder epithelium is increased by lamellae, and the basal plasma membrane forms invaginations. In the bladder syncytium of P. squamatus both apical lamellae and basal invaginations are more developed and mitochondria are also more numerous. The excretory atrium is lined by a syncytium with nucleated cytons located in the surrounding parenchyma. The atrium lining is not continuous with the body tegument and possesses specific secretory inclusions and a thick glycocalyx. Septate junctions connect the atrium syncytium to the excretory bladder epithelium at its anterior end and to the syncytial excretory epithelium lining the caudal vesicle and the lateral caudal ducts at its posterior. In the excretory pores the caudal duct syncytium is joined to the tegument by septate desmosomes.

Ultrastrukturelle Ver�nderungen der Altersblase

Recent prospective, comparative ultrastructural/urodynamic studies on geriatric voiding dysfunction, including its natural evolution, have revealed that abnormalities of detrusor behavior have specific correlates in detrusor microstructure represented by distinctive electron-microscopic patterns. Each electron-microscopic pattern comprises a constellation of features in two or all three tissue compartments of the detrusor (smooth muscle, interstitium, intrinsic nerves). The pattern characteristic of each dysfunction is the same in detrusors of men and women. The electron-microscopic patterns are additive when multiple abnormalities coexist. All distinctive patterns of various clinical voiding dysfunctions can readily be defined qualitatively in endoscopic biopsies of the detrusor. These observations, including those on material studied for the natural evolution of geriatric voiding dysfunction, have led to the proposal of a clinical/structural definition of the normal aging detrusor and the development of an algorithm for pathologic diagnosis of geriatric voiding dysfunction.

The detrusor muscle cell in bladder outlet obstruction--ultrastructural and morphometric findings

OBJECTIVE

Lower urinary tract symptoms (LUTS) in elderly males are not solely caused by bladder outlet obstruction (BOO) and may be at least partly attributable to detrusor dysfunction. Urodynamically, patients may show instability, hypocontractility, BOO or combinations of these findings. These findings have been related to specific ultrastructural changes in detrusor smooth muscle cells; however, this relationship is controversial. The aim of this study was to correlate ultrastructural findings in patients with BOO with urodynamic parameters.

MATERIAL AND METHODS

In 25 men with BOO verified by means of a full urodynamic evaluation, including a pressure-flow study, a detrusor biopsy was obtained. Six men without BOO served as controls. Biopsies for electron microscopy were analysed semiquantitatively and morphometrically to determine the presence of muscle cell hypertrophy, variation in intercellular distances, occurrence of abnormal cell junctions and configurations and intracellular changes.

RESULTS

The only parameter which was found to relate to the degree of obstruction in BOO was an increase in intra- and interfascicular elastin, all other correlations not reaching significance.

CONCLUSION

This study does not confirm a specific relationship between ultrastructural detrusor smooth muscle features and various types of BOO. Therefore ultrastructural investigation of detrusor smooth muscle cells cannot replace urodynamic evaluation in the classification of LUTS.

Morphological analysis of the acute effects of overdistension on the extracellular matrix of the rat urinary bladder wall

PURPOSE

To investigate the morphological effects of acute overdistension in the structure of the extracellular matrix of the bladder wall in rats.

MATERIALS AND METHODS

The bladders of a group of 6 male Wistar rats were transurethrally overdistended for 3 hours. Another identical group (the control group) was only submitted to a sham operation. Specimens from the bladder dome were analyzed with light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM).

RESULTS

LM--The control group bladders had a 4 to 5 layer urothelium, a lamina propria, and a smooth muscle layer with longitudinal and transversal fibers. The overdistended bladders presented an intense interstitial infiltrate in the lamina propria, and a less intense infiltrate among the smooth muscle fibers. TEM--The cells of the overdistended bladders had a significant amount of vacuoles, unlike the control bladders, where such vacuoles were scarce or absent. SEM--A delicate three-dimensional mesh of collagen fibrils was observed in the lamina propria of the bladder walls from the control group. Whilst for the control group this mesh consisted of distinct geometric structures, with mostly circular cellular spaces surrounded by the fibrils, the overdistended group showed evidence of distortion of the mesh, with flattened and elongated cellular spaces.

CONCLUSIONS

Acute bladder overdistension induces structural modifications, altering the arrangement and interaction of collagen fibrils, as well as incipient tissue damage as edema in the lamina propria and smooth muscle layers.

The 3D structure of the human urinary bladder mucosa: a scanning electron microscopy study

We performed a scanning electron microscopy study on the human urinary bladder tunica mucosa. Specimens from bladder biopsies were treated with OsO4 maceration and 1N NaOH maceration methods prior to SEM observation to disclose the three-dimensional organization of the lamina propria, basal lamina and urothelium. The lamina propria housed a well developed capillary plexus just below the basal lamina; the urothelium presented a typical three-layered organization with basal, intermediate and superficial cells. The intermediate cells appeared essentially similar to basal cells in their external features and stretched from the basal lamina up to the superficial layer. The most superficial cells appeared consistently flattened and interconnected by extensive junctional complexes. They showed a peculiar specialization, their apical plasmalemma being thickened with distinctive, stiff plaques, in contrast with the underlying globular or spindle-shaped cells whose plasmalemma was only covered by short microvillosities.

Papillary clusters as a diagnostic pitfall in urinary cytology of pseudosarcomatous fibromyxoid tumor of the bladder. A case report

BACKGROUND

Pseudosarcomatous fibromyxoid tumor (PFT) of the urinary bladder is an uncommon benign lesion that can involve any site in the bladder. Cellular features of PFT of the bladder are exceedingly rare. We describe the urinary cytology in a PFT patient who displayed numerous papillary fragments that suggested a malignant tumor.

CASE

A 52-year-old man was seen at the hospital for evaluation of gross hematuria. At cystoscopy, the urologist observed a 3-cm, smooth, polypoid and ulcerated mass extending from the trigone to the bladder neck. Urinary cytology showed many papillary clusters with irregular nuclear margins in the bloody cell background. No spindle cells were noted. Cytology was interpreted as papillary growth, factor transitional cell carcinoma, grade 2-3. A laparotomy with partial resection of the urinary bladder was carried out, and histologically the tumor was composed of spindle, stellate, fibroblastic cells embedded in myxoid stroma with little collagen. Immunohistochemical and ultrastructural studies revealed the fibroblastic nature of the lesion. The final diagnosis was PFT of the bladder on the basis of histologic examination of the resected material.

CONCLUSION

Papillary fragments are a diagnostic pitfall in urinary cytology of PFT lesions.

Ultrastructural basement membrane topography of the bladder epithelium

The basement membrane underlies epithelium and separates it from deeper tissues. Recent studies suggest that nanoscale topography of the surface of basement membrane may modulate adhesion, migration, proliferation and differentiation of overlying epithelium. This study was performed to elucidate nanoscale topographic features of basement membrane of the bladder. Bladder tissues were obtained from three adult female rhesus macaques. A process was developed to remove the epithelium while preserving the underlying basement membrane, and tissues were evaluated by immunohistochemistry and scanning electron microscopy (SEM). Detailed measurements were made of stereo SEM images to quantitatively define topographic features. Measurements made from multiple SEM images of bladder basement membrane provided the following values for topographic features: mean feature height, 178+/-57 nm; mean fiber diameters, 52+/-28 nm; mean pore diameter, 82+/-49 nm; and mean interpore distance (center to center), 127+/-54 nm. These dimensions are similar to those reported previously for basement membranes of other species and anatomical locations. This information provides a rational basis for design of nanostructured biomaterials to produce composite grafts for repair or replacement of segments of the urinary tract.

Intracellular bacterial biofilm-like pods in urinary tract infections

Escherichia coli entry into the bladder is met with potent innate defenses, including neutrophil influx and epithelial exfoliation. Bacterial subversion of innate responses involves invasion into bladder superficial cells. We discovered that the intracellular bacteria matured into biofilms, creating pod-like bulges on the bladder surface. Pods contained bacteria encased in a polysaccharide-rich matrix surrounded by a protective shell of uroplakin. Within the biofilm, bacterial structures interacted extensively with the surrounding matrix, and biofilm associated factors had regional variation in expression. The discovery of intracellular biofilm-like pods explains how bladder infections can persist in the face of robust host defenses.

Confocal laser scanning microscopy of urinary bladder after intravesical instillation of a fluorescent dye

OBJECTIVES

To assess the potential of confocal laser scanning microscopy for imaging of the urinary bladder after intravesical instillation of a fluorescent dye.

METHODS

The study was performed on the bladder of male Copenhagen rats. For confocal fluorescence microscopy (CFM), a standard confocal laser scanning microscope (Zeiss LSM 410) was used. Before measuring, the fluorescent marker SYTO 17 was instilled intravesically. After 2 hours of incubation, the rat was killed, the bladder excised and opened, and CFM was performed starting from the surface going through the urothelium and superficial layers of the lamina propria. Except for the opening incision, the bladder was left intact and no biopsies were taken. After imaging, the bladder was sent for conventional histologic studies.

RESULTS

CFM allows imaging of cellular details of the entire urothelium (superficial umbrella cells, intermediate, and basal urothelial cells) and superficial layers of the lamina propria. CFM images are close to those obtained by standard microscopy after conventional hematoxylin-eosin staining. Cell structure (eg, shape, size, chromatin texture, nucleoli, mitotic figures, nuclear/cytoplasmic ratio), as well as the structure of the connective tissue (eg, collagen fibers, blood vessels, erythrocytes), can be studied, allowing a standard histologic evaluation. Furthermore, in contrast to conventional histologic evaluation, CFM provides three-dimensional information and allows the study of intact tissue representing the true in vivo situation.

CONCLUSIONS

CFM enables the study of the microscopic anatomy of bladder mucosa in its in vivo state. In combination with optical fiber bundles, endoscopic microscopy of the bladder may be possible in the future.

[Morphological and functional changes of tissue receptors of an organ plexus under the effect of blockers of cytoskeleton assembly]

Colchicine and cytochalasine C exert modifying action on tissue receptors of urinary bladder of the frog. Under the effect of cytochalasine the period of vital staining of receptors were changed. Latent period of decoloration grew 37-56% longer while the period of staining accumulation grows 18% shorter. The forming of granules was also altered 2 types of terminal plaques were distinguished according to this sign in the course of treatment with colchicine and 3 types in the experiment with cytochalasine. Modifying action of cytochalasine was greater. Cytochalasin caused mass appearance of round intensely stained plaque the appearance of which was obviously connected with microtubules destruction. Mean area of terminals profile field also increased. Spontaneous impulse activity of receptors was significantly suppressed. Specificity of responses to colchicine and cytochalasine was probably conditioned by their effect on different elements of cytoskeleton.

The effect of ovariectomy and estradiol replacement on collagen and elastic fibers in the bladder of rats

The authors quantified the collagen and elastic fibers in the bladder wall of ovariectomized rats with and without estradiol replacement. This study was conducted on 60 3-month-old Wistar rats. Group 1 remained intact; group 2 underwent bilateral ovariectomy and were sacrificed after 30 days; group 3 were sham operated and sacrificed after 30 days; group 4 had a bilateral ovariectomy and after 30 days were started on subcutaneous injections of 17beta-estradiol (10 microg/kg body weight) for 90 days; group 5 were sham operated and after 30 days were on started subcutaneous sesame oil replacement (0.2 ml/day) for 90 days; group 6 had a bilateral ovariectomy and after 30 days were started on subcutaneous sesame oil replacement (0.2 ml/day) for 90 days. Sirius red and Weigert's resorcin-fuchsin were used to stain collagen and elastic fibers on paraffin-embedded rat bladder sections. The M-42 grid system was used to quantitatively analyze the fibers. Ovariectomy had no effect on the volumetric density and absolute volume of the collagen and elastic fibers in the bladder wall of rats, or on the weight of the bladder. Estradiol replacement in castrated animals did not demonstrate any significant difference in the stereological parameters compared to the castrated group without hormonal replacement.

Analysis of feline urinary calculi and urethral plugs by infrared spectroscopy and scanning electron microscopy

The chemical constituents of 34 feline urinary calculi and five urethral plugs were analysed by infrared spectroscopy. The analysis revealed that 18 (52.9 per cent) of the calculi contained magnesium ammonium phosphate hexahydrate (struvite) as the major component; 10 (29.4 per cent) contained complex ammonium urates (three of them also containing calcium phosphate, mainly on the surface); three were composed of calcium phosphates and three were composed mainly of calcium oxalate mono and dihydrates. The urethral plugs were composed primarily of struvite, but also contained large amounts of organic matter. The examination of 16 selected samples by scanning electron microscopy and electron dispersive x-ray analysis revealed that their crystalline structures were similar to those of canine stones.

Giant vacuoles arising during ADH-induced transcellular bulk water flow across the epithelium of the frog urinary bladder

Structural changes of the cytoplasm of urinary bladder granular cells after an antidiuretic hormone (ADH) stimulation of water transport were studied using standard and cryogenic methods of electron microscopy. Numerous changes occurred in these cells, the cytoplasm of the granular cells becoming swollen, and the intercellular spaces enlarged. Most granules become fused with the apical membrane. Under maximal ADH action, giant vacuoles appear in the cytoplasm of granular cells, in association with microfilaments and microtubules. Analysis of ultrastructure of the granular cells has established the origin of giant vacuoles from the cis -cisterna of the Golgi complex. A hypothesis based on the morphofunctional homology of giant vacuoles in granular cells with the contractile vacuoles of Protozoa is proposed in which the giant vacuoles ('contractile-like' vacuoles) are seen as operating a osmoregulatory role in these cells. It is also proposed that microtubules and microfilaments participate in giant vacuole migration through the cytoplasm.

Disruption of bladder epithelium barrier function after spinal cord injury

Neural-epithelial interactions are hypothesized to play an important role in bladder function. We determined whether spinal cord injury (SCI) altered several indicators of urinary bladder epithelium barrier function, including continuity of the surface umbrella cell layer, transepithelial resistance (TER), and urea and water permeability. Within 2 h of SCI, significant changes in uroepithelium were noted, including disruption of the surface umbrella cells and an approximately 50% decrease in TER. By 24 h, TER reached a minimum and was accompanied by significant increases in water and urea permeability. Regeneration of the surface uroepithelium was accomplished by 14 days after SCI and was accompanied by a return to normal TER and urea and water permeabilities. This early disruption of the uroepithelial permeability and accompanying changes in uroepithelial morphology were prevented by pretreatment with hexamethonium (a blocker of ganglion transmission), indicating involvement of sympathetic or parasympathetic input to the urinary bladder. In addition, prior treatment with capsaicin worsened the effect of SCI on uroepithelial permeability, suggesting that capsaicin-sensitive afferents may play a protective role in the process. These results demonstrate that SCI results in a significant disruption of the urinary bladder uroepithelium and that these changes may be mediated in part by an interaction with bladder nerves.

The effect of inflammation on rat urinary bladder-dependent relaxation in coaxial bioassay system

The effect of urinary bladder inflammation on the activity of a bladder-derived relaxant factor in the coaxial bioassay system was examined. Bladder inflammation was induced by intraperitoneal (i.p.) cyclophosphamide or intravesical lipopolysaccharide (LPS) injection to male rats. In precontracted rat anococcygeus muscle that was placed within rat bladder (coaxial bioassay system), acetylcholine induced a relaxation response, which was not altered by the denudation of urothelium or incubation with indomethacin and N(G)-methyl-L-arginine. Acetylcholine-induced relaxation was significantly attenuated, when bladders were removed from cyclophosphamide- and LPS-pretreated group of rats and were used with intact urothelium in the coaxial bioassay system. However, the impairment acetylcholine response in both pretreatment groups was not observed after denudation of the bladder urothelium. These results showed that bladder inflammation did not alter the synthesis and/or release of this bladder-derived relaxant factor, which is neither a cyclooxygenase product nor nitric oxide, but restricted its demonstration by coaxial bioassay assembly probably due to inflammation-induced mucosal oedema.

Inverse expression of uroplakins and inducible nitric oxide synthase in the urothelium of patients with bladder outlet obstruction

OBJECTIVE

To assess the expression and distribution of uroplakins, protein subunits of the asymmetric unit membrane (AUM), and inducible nitric-oxide synthase (iNOS) in the urinary bladder urothelium of patients with bladder outlet obstruction (BOO) caused by benign prostatic hyperplasia (BPH).

PATIENTS AND METHODS

Urinary bladder urothelium samples from 15 men (mean age 69 years) with BOO secondary to BPH were processed for light and electron immunocytochemistry. Uroplakins and iNOS were detected, and areas of apical surface covered with AUM were compared with those of iNOS-positive urothelial cells.

RESULTS

Areas of superficial urothelial cells with no AUM were found in all obstructed bladder samples. The immuno-electron microscopy showed that the uroplakin-positive cells had the characteristic appearance of terminally differentiated umbrella cells, whereas cells from the uroplakin-negative regions were undifferentiated, typically showing microvilli on their apical surface. iNOS was not detected in areas with continuous AUM staining, but was readily detected in the uroplakin-negative areas. There was an inverse correlation between the intensity of uroplakin and iNOS staining.

CONCLUSIONS

In patients with BOO associated with BPH, some superficial urothelial cells lacked the AUM, suggesting focal compromise of the blood-urine permeability barrier. In such relatively undifferentiated urothelial zones there was an accompanying increase in the expression of iNOS, which marks perturbed urothelial differentiation and may modulate bladder response to the outlet obstruction.

A prospective evaluation of detrusor ultrastructural changes in bladder outlet obstruction

OBJECTIVES

To characterize the ultrastructure of detrusor smooth muscle from the bladders of symptomatic men with bladder outlet obstruction (BOO) caused by benign prostatic enlargement (BPE) and compare this with a matched control group; to determine how detrusor morphology relates to urodynamic findings and to develop a better understanding of the natural development of bladder dysfunction related to BOO.

PATIENTS AND METHODS

Twelve men (mean age 66 years, range 52-77) with urodynamically confirmed BOO caused by BPE and 12 age-matched asymptomatic normally voiding controls (mean age 67.8 years, undergoing cystoscopy for other conditions) had detrusor biopsies taken endoscopically. The biopsies were processed for electron microscopy using standard methods. The specimens were randomized and examined at medium power (x 4000) by an examiner unaware of the urodynamic findings. Any ultrastructural patterns identified subjectively were noted.

RESULTS

In the BOO group eight of the 12 men had a myohypertrophic pattern, half of which were associated with a degenerative pattern of hypocontractility. Of the remaining four patients, two had the degenerative pattern alone and two were normal. The six men whose biopsies had a degenerative pattern had consistent postvoid residual volumes of > 150 mL; the remainder all had volumes of < 150 mL. There were no ultrastructural abnormalities in the control patients.

CONCLUSIONS

There are interesting qualitative ultrastructural changes in the obstructed detrusor, but they are not consistent enough to provide a reliable diagnostic tool. However, there may be an important relationship between the degenerative pattern and postvoid residual volume in BOO.

Biochemical and morphological effects of bladder pumping on the urinary bladder in rats

AIMS

To study the influence of bladder pumping on the urinary bladder in 44 female rats.

METHODS

Under halothane anesthesia, a urethral catheter was inserted into the bladder of 27 rats, and air (0.4-0.8 mL) was pumped in and out of the bladder at 0.5 cycles/second for a period of 5 minutes. Twenty-four hours after pumping, the bladder was harvested for measurement of the tissue levels of myosin, actin, and nerve growth factor, as well as for electron microscopy. In nine of the 27 rats, cystometry was performed without anesthesia before and 1, 7, 30, and 90 days after bladder pumping. The remaining 17 rats that did not undergo pumping were anesthetized and their bladders were harvested as a control.

RESULTS

Bladder pumping increased the bladder capacity and decreased the maximum bladder contraction pressure, but did not increase the residual volume. Bladder pumping also increased the tissue level of nerve growth factor and decreased the levels of myosin and actin. Electron microscopy showed degeneration of bladder smooth muscle cells and nerve fibers after bladder pumping, as well as derangement and disruption of collagen fiber bundles in the bladder wall. These functional and morphological effects of pumping disappeared within 90 days.

CONCLUSIONS

Bladder pumping therapy appears to have various effects on the bladder wall collagen fiber bundles, smooth muscle cells, and nerves.

Evidence of gap junctions in the stable nonobstructed human bladder

PURPOSE

Gap junctions are thought to synchronize muscle cell actions by promoting intercellular communications. Since it is still a matter of debate whether smooth muscle cells in the bladder are electrically coupled, we investigated the occurrence of gap junctions and the gap junction forming protein connexin 45 in normal human detrusor.

MATERIALS AND METHODS

Detrusor smooth muscle was obtained during radical cystectomy in 6 patients. For transmission electron microscopy studies samples were high pressure frozen and cryo-fixed. Additional frozen samples were processed for freeze fracture/freeze fracture immunolabeling analyses or for reverse transcriptase-polymerase chain reaction using primers for connexin 45. Furthermore, a set of samples was fixed with Bouin's solution, embedded in paraffin and used for immunohistochemistry with a polyclonal antibody against connexin 45 as well as for in situ hybridization studies with digoxigenin labeled connexin 45 riboprobes.

RESULTS

Ultrastructural and freeze fracture studies showed gap junctions at detrusor smooth muscle cells. However, these gap junctions appeared to be small and irregularly shaped. Reverse transcriptase-polymerase chain reaction and in situ hybridization showed that connexin 45 mRNA was expressed in the detrusor muscularis. Furthermore, we detected prominent connexin 45 immunoreactions at detrusor smooth muscle cells. Freeze fracture immunolabeling techniques revealed connexin 45 signals at small gap junctional plaques.

CONCLUSIONS

To our knowledge this study is the first to provide morphological, molecular biological and immunohistochemical evidence that smooth muscle cells of stable human detrusor are electrically coupled through gap junctions. These results may contribute to new concepts in the understanding of bladder physiology.

Structural basis of neurogenic bladder dysfunction. I. Methods of prospective ultrastructural study and overview of the findings

PURPOSE

We standardize procedures for ultrastructural study of detrusor smooth muscle and intrinsic nerves in neurogenic bladder dysfunction in the human, and present an overview of the findings.

MATERIALS AND METHODS

The study included 18 female and 33 male patients 7 to 96 years old. They had neurogenic bladder dysfunction with hyperreflexia for less than 1 to 43 years, resulting from upper motoneuron lesions (spinal cord injury 25, brain disorder 17) or combined upper and lower motoneuron deficit (meningomyelocele 9). Endoscopic or open bladder biopsies were processed for ultrastructural study of detrusor smooth muscle and intrinsic neural elements. Qualitative morphologic criteria of muscle cell arrangement, degeneration and cell-cell contacts, as well as those of degeneration and regeneration of intrinsic neural elements are defined.

RESULTS

Five biopsies from the brain disorder group had insufficient smooth muscle and were excluded from study. The remaining 46 biopsies were evaluated by electron microscopy, and all displayed the complete dysjunction pattern of detrusor overactivity. Most displayed degeneration and regeneration of intrinsic axons but disproportionately limited muscle cell degeneration, irrespective of detrusor contractility. The brain disorder group biopsies displayed many more ultrastructurally normal axons than the meningomyelocele and spinal cord injury group biopsies (median 33% versus 8% or less).

CONCLUSIONS

Upper motoneuron neurogenic bladder dysfunction in humans is associated with intrinsic neuromuscular defects in the detrusor. Ultrastructural features of these defects suggest morphologic markers that not only may distinguish neuropathic from nonneuropathic bladder dysfunction, but also may point to the anatomical level of the neurogenic deficit.

Ultrastructural basis for the efficiency of an ileal orthotopic neobladder 27 years after surgery

The morphological and functional basis of the excellent clinical outcome of ileal orthotopic neobladders are largely unknown. Only long-term follow-up studies will provide an adequate answer to this unsettled question. We have studied a patient who underwent this type of surgery over 27 years ago. Besides an important secretive adaptation we have found, at the ultrastructural level, that the monolayered epithelium does not show signs of true metaplasia and that changes had occurred in the intercellular junctions, namely that desmosomes are significantly increased. Although limited to a single case, these features, if confirmed by further observations, suggest a working hypothesis for the understanding of the definitive phenotypic adaptation of the ileal epithelium to the new aggressive environment.

[Ultrastructural observation of detrusor in BPH patients]

OBJECTIVES

To observe the detrusor ultrastructure in BPH patients and to investigate the relationship between detrusor instability and ultrastructure.

METHODS

The patients were divided into groups of detrusor instability(DI) and detrusor stability(DS) according to urodynamics examination. The structure of the detrusor were observed by light microscopy and transmission electron microscopy(TEM).

RESULTS

The intercellular intermediate junctions and cytoplasmic process junctions in DS were 11.34 +/- 3.23 and 4.26 +/- 1.78 respectively. The intercellular intermediate junctions decreased obviously (3.12 +/- 1.47, P < 0.01) instead of a large amount of cytoplasmic process junctions (26.37 +/- 7.14, P < 0.01) in DI.

CONCLUSIONS

There is a close relevance between intercellular junctions and DI. The observation of the ultrastructure of the detrusor is helpful for the diagnosis of BPH with DI and for the clinical treatment.

The role of the human bladder lamina propria myofibroblast

OBJECTIVES

To describe the ultrastructure and relationship to nerves of the myofibroblast in the human bladder lamina propria, and discuss its possible role in bladder function, including sensing stretch, as the response of the bladder to stretch has been thoroughly investigated by afferent nerve recordings, but specialized stretch sensing organs have yet to be identified.

MATERIALS AND METHODS

Flexible cystoscopic bladder biopsies were obtained from patients with detrusor hyper-reflexia and from controls. Systematic electron micrographs were obtained throughout the lamina propria, and the presence and location of cells with ultrastructural characteristics of myofibroblasts noted, together with their relation to surrounding nerves.

RESULTS

Within the lamina propria there was a layer of cells with the cytological characteristics of both fibroblasts and smooth muscle cells, that included bundles of fine cytoplasmic filaments, dense bodies, linear arrays of subsurface vacuoles, and the presence of an interrupted basal lamina. This combination of features is characteristic of the myofibroblast. These cells had close contacts with unmyelinated axonal varicosities containing a mixture of clear and large dense-cored vesicles, or clear vesicles alone.

CONCLUSIONS

There is a layer of cells with the ultrastructural characteristics of myofibroblasts within the human bladder lamina propria. Their close contacts with nerves containing both small clear, and small clear with dense-cored, vesicles implies they have both an efferent and an afferent nerve supply, possibly functioning as a bladder stretch receptor. Furthermore, because of their similarities with the interstitial cells of Cajal in the gut, which are claimed to modulate small intestinal function, we discuss other possible roles for bladder lamina propria myofibroblasts.

Role of membrane proteins in permeability barrier function: uroplakin ablation elevates urothelial permeability

Although water, small nonelectrolytes, and gases are freely permeable through most biological membranes, apical membranes of certain barrier epithelia exhibit extremely low permeabilities to these substances. The role of integral membrane proteins in this barrier function has been unclear. To study this problem, we have ablated the mouse gene encoding uroplakin III (UPIII), one of the major protein subunits in urothelial apical membranes, and measured the permeabilities of these membranes. Ablation of the UPIII gene greatly diminishes the amounts of uroplakins on the apical urothelial membrane (Hu P, Deng FM, Liang FX, Hu CM, Auerbach AB, Shapiro E, Wu XR, Kachar B, and Sun TT. J Cell Biol 151: 961-972, 2000). Our results indicate that normal mouse urothelium exhibits high transepithelial resistance and low urea and water permeabilities. The UPIII-deficient urothelium exhibits a normal transepithelial resistance (normal 2,024 +/- 122, knockout 2,322 +/- 114 Omega. cm(2); P > 0.5). However, the UPIII-deficient apical membrane has a significantly elevated water permeability (normal 0.91 +/- 0.06, knockout 1.83 +/- 0.14 cm/s x 10(-5); P < 0.05). The urea permeability of the UPIII-deficient membrane also increased, although to a lesser extent (normal 2.22 +/- 0.24, knockout 2.93 +/- 0.31 cm/s x 10(-6); P = 0.12). These results indicate that reduced targeting of uroplakins to the apical membrane does not significantly alter the tight junctional barrier but does double the water permeability. We provide the first demonstration that integral membrane proteins contribute to the apical membrane permeability barrier function of urothelium.

Trajectorial organisation of cytokeratins within the subapical region of umbrella cells

The subapical region of umbrella cells in the urinary bladder contains a dense cytokeratin (CK) network. Yet, this network should enable a very intensive traffic of specific fusiform vesicles involved in alterations of the surface area of the apical membrane. Therefore, the cytokeratins should be organised in a way to be both mechanically strong and also passable for fusiform vesicles. The supramolecular organisation of the CKs in the subapical region of umbrella cells in mice was studied by conventional fluorescence, confocal laser microscopy, and TEM. It has been found that the first 150 to 300 nm under the apical membrane is filled with fusiform vesicles and only below that the CK network begins. The CK 7 and CK 20 compose a subapical network, which is created as an array of parallel trajectories pointing to the apical plasma membrane. The network is framed by a strong wall of CK, which is parallely aligned in neighbouring cells. The double labelling of the urothelial-specific membrane proteins, uroplakins, and CKs proved the presence of fusiform vesicles within these trajectories. The measurements proved that the trajectory diameter in the upper half of the network is smaller than in the lower half. The diameters of the trajectories in animals with distended bladders exceeded those in contracted bladders for 70%, which most likely facilitates the transport of fusiform vesicles to the apical membrane. Discovery of the subapical CK network elucidates the until now undescribed supramolecular organisation of CKs in the apical region of urothelial cells.

[Microtubule dynamics in epithelial cells]

Microtubules (MTs) are necessary components of all eukaryotic cells. They fulfill various functions being involved in cell division, ciliar and flagellar beating, cell shape maintaining, organelle distribution in the cell, organization of other cytoskeletal elements. Dynamic features of MTs have been commonly studied in vitro or on undiffirentiated cultured cells by means of molecular and ultrastructural methods. It is generally accepted that the phenomenon of dynamic instability is the major mechanism of MT turnover in the cell. MTs radiate from the centrosome and take part in the distribution of cell organelles. In addition, epithelial, nerve, and skeletal muscle cells contain non-centrosomal MTs. A few hypothesis of their origin have been so far put forward. According to the capture-release hypothesis, MTs are first nucleated on the a centrosome, then release to be driven in various parts of the cell by molecular motors. Some alternative mechanisms of non-centrosomal MT formation are also proposed in literature. For example, the nucleation sites were reported not only in centrosomes but also in other parts of cells, such as the apical membranes of epithelial cells, the nuclear membrane of muscle cells, pigment granule aggregates of melanophores. On studying frog urinary bladder and large intestine epithelial cells the authors observed in these cells numerous non-centrosomal MTs. This makes epithelial cells, good models for analysing structural and dynamic features of non-centrosomal MTs in differentiated cells. For the urinary bladder the pool of specific granules may serve as MT organizing centers. Non-cenrosomal MTs of these cells have big diameters (35-38 nm) and form bundles oriented in the apical-basal axis of the cell. In addition, non-centrosomal MTs of these cells may participate in the transport of specific granules and giant vacuoles that appear under stimulated water flows through the cell.

Vanilloid receptor 1 expression in the rat urinary tract

Previous findings have shown that the capsaicin sensitivity of sensory fibres is due to the expression of a specific membrane protein, the vanilloid receptor type 1 (VR1). In the present work we studied the distribution, morphology and the neurochemical content of nerve fibres expressing this receptor in the rat urinary tract. Immunolabelling was performed against the VR1 and the positive fibres were examined by light and electron microscopy. Colocalisation of VR1 and substance P or calcitonin gene-related peptide immunoreactivities, and isolectin B4 binding, was evaluated under the confocal microscope. In addition, the effect of intravesical administration of resiniferatoxin, an ultra-potent vanilloid receptor agonist, in the receptor expression in the bladder was also studied. Numerous VR1-immunoreactive fibres were found in the mucosa and muscular layer of the entire urinary tract except the kidney. In the bladder, most fibres were also substance P- or calcitonin gene-related peptide-immunoreactive but did not bind isolectin B4. Under the electron microscope VR1 immunoreactivity was confined to unmyelinated axons and varicosities containing small clear and large dense-core synaptic vesicles. They occurred beneath or among epithelial cells or closely apposed to smooth muscle cells. Intravesical resiniferatoxin decreased VR1 immunoreactivity transiently. These data indicate that primary sensory fibres expressing VR1 are extremely abundant in the rat urinary tract and that, in contrast to the skin, they belong almost exclusively to the peptide-containing sub-population of primary afferents. As capsaicin-sensitive bladder afferents are involved in nociception and reflex micturition control, the numerous free terminal nerve endings expressing VR1 in the mucosa seem more adequate to accomplish the former function. However, the close apposition between VR1-expressing fibres and smooth muscle cells suggests that they may also encode the tonus of the muscular layer.

Antigenic and ultrastructural markers associated with urothelial cytodifferentiation in primary explant outgrowths of mouse bladder

The purpose of this study was to establish an in vitro culture model that closely resembles whole mouse urothelial tissue. Primary explant cultures of mouse bladder were established on porous membrane supports and explant outgrowths were analysed for morphology and the presence of antigenic and ultrastructural markers associated with urothelial cytodifferentiation. When examined at the ultrastructural level, the cultured urothelium was polarized and organized as a multilayered epithelium. Differentiation was found to increase from the porous membrane towards the surface and from the explant towards the periphery of the culture. Scanning and transmission electron microscopical analysis of the most superficially-located cells revealed four successive differentiation stages: cells with microvilli, cells with ropy microridges, cells with rounded microridges, and highly-differentiated cells with asymmetric unit membrane (AUM) plaques forming rigid microridges and fusiform vesicles. The more highly-differentiated cells were numerous at the periphery of the culture, but rare close to the explant. Epithelial organization was stabilized by well developed cell junctions. Immunolabeling demonstrated that superficial urothelial cells in culture: (1) develop tight junctions, E-cadherin adherens junctions and abundant desmosomes and (2) express uroplakins and cytokeratin 20 (CK 20). Using a culture model of primary explant outgrowth we have shown that non-differentiated mouse urothelial cells growing on a porous membrane show a high level of de novo differentiation.

Vascular architecture of normal human urinary bladder and its remodeling in cancer, as revealed by corrosion casting

The vasculature of normal human urinary bladder wall and its tumors were studied using corrosion casting and scanning electron microscopy. In the normal wall, a regular organization of highly tortuous horizontal and vertical vessels allows accommodation of the vascular system to spatial changes resulting from the filling/voiding cycle. The vasculature of tumors is a result of remodeling of preexisting wall vessels associated with gradual growth of the neoplastic tissue. The shape and arrangement of blood vessels in different regions of the tumor seem to reflect a variable dynamics of tumor development and possible influence of various angiogenesis-promoting growth factors.

Effects of bladder volume on transabdominal ultrasound measurements of intravesical prostatic protrusion and volume

BACKGROUND

A filled bladder acts as an acoustic window for transabdominal ultrasound measurements of intravesical prostatic protrusion and volume. The aim of this study is to evaluate the effects of bladder volume on transabdominal ultrasound measurements of these parameters.

METHODS

Twenty-two patients undergoing transurethral resection of the prostate (TURP) were studied. Under general anesthesia just before TURP, a transrectal ultrasound measurement of prostate volume was obtained. The bladder was then filled in a stepwise manner with 100, 200, 300, 400 and 500 mL. At each volume, the intravesical prostatic protrusion and prostatic volume were measured transabdominally using ultrasound.

RESULTS

There was an obvious trend of decreasing mean transabdominal intravesical prostatic protrusions with increasing bladder volume. The mean transabdominal intravesical prostatic protrusion at bladder volumes 100, 200, 300, 400 and 500 mL was 9.1, 8.8, 7.4, 5.8 and 4.6 mm, respectively. The bladder volume at which maximum prostatic protrusion occurred was between 100 and 200 mL. The mean transabdominal prostate volume at the five increasing bladder volumes was 50.6, 48.7, 49.2, 47.9 and 41.4 mL, and these were correlated to transrectal prostate volume, particularly when the bladder volume was less than 400 mL.

CONCLUSIONS

Transabdominal ultrasound measurement of prostatic protrusion is dependent on bladder volume. Transabdominal ultrasound measurement of prostatic volume correlates well with the transrectal measurement of the same parameter when the bladder volume is less than 400 mL.

Does ultrastructural morphology of human detrusor smooth muscle cells characterize acute urinary retention?

PURPOSE

Acute urinary retention is relatively rare in otherwise healthy men. The condition may be attributable to a combination of obstruction and detrusor hypocontractility. We determined whether acute or chronic urinary retention is accompanied by characteristic ultrastructural features in bladder detrusor smooth muscle cells and whether any of these ultrastructural features may be useful for classifying these conditions.

MATERIALS AND METHODS

Bladder biopsies of 15 men, including 13 in acute and 2 in chronic urinary retention, and 6 controls were examined by transmission electron microscopy. They were semiquantitatively and morphometrically analyzed for degenerative changes, cellular hypertrophy, variations in intercellular distances, abnormal cell junctions and configurations, and intracellular changes.

RESULTS

No significant ultrastructural features were noted in the detrusor muscle of patients in acute urinary retention compared with controls.

CONCLUSIONS

We cannot confirm the reports of others that characteristic ultrastructural features in smooth muscle cells accompany bladder outlet obstruction and detrusor hypocontractility.