Showing papers on "Urinary bladder published in 1990"

Activation of unmyelinated afferent fibres by mechanical stimuli and inflammation of the urinary bladder in the cat.

Abstract: 1. We examined the functional properties of unmyelinated primary afferent neurones innervating the pelvic viscera in twenty-five anaesthetized cats. The axons were isolated from the intact dorsal root and the intact or chronically de-efferented ventral root of the segment S2. All units were electrically identified with electrical stimulation of the pelvic nerve. 2. The responses of the neurones were studied with natural stimulation of the urinary bladder using innocuous and noxious increases of intravesical pressure and at the onset of an acute artificial inflammation induced by intraluminal injection of mustard or turpentine oil. 3. Out of 297 unmyelinated afferent units isolated from the dorsal root, seven were excited by an increase of the intravesical pressure during contractions and distension of the urinary bladder. These units were silent when the bladder was empty and had thresholds of 30-50 mmHg which are presumed to be noxious. Further increases of the intravesical pressure were accurately encoded by the discharge rate of the fibres. Out of sixty-eight unmyelinated afferent units isolated from the ventral root none was activated by these stimuli. 4. Intraluminal injection of mustard oil excited mechanosensitive units at short latency. The discharge was not closely related to changes of the intravesical pressure and the units displayed on-going activity after the irritant had been removed. This observation suggests that the units had also chemosensitive properties and that the receptive endings were located in the bladder wall. 5. In sixteen cats ninety-five afferent fibres that were not activated by noxious mechanical stimuli of the urinary bladder were systematically tested with intraluminal injections of mustard oil. This excited 7/67 dorsal root units and 4/28 ventral root units with short latency. Intraluminal application of turpentine oil, tested on twenty-six afferents in four animals, did not produce a rapid excitation. 6. Following the induction of an inflammation some previously non-mechanosensitive units started to respond to changes of intravesical pressure in the biologically relevant pressure range of the urinary bladder. 7. In conclusion, a small subpopulation (2.4%) of unmyelinated visceral afferents responds to high, presumably noxious, intravesical pressure and intraluminal application of chemical irritants. Acute inflammation excites a larger proportion of afferents (9.5%) that are not activated by acute noxious mechanical stimulation of the normal urinary bladder. In the inflamed bladder some previously non-mechanosensitive units started to respond to increases of intravesical pressure. These novel types of chemosensitive receptors may contribute considerably to the pathogenesis of visceral pain states.

Biology and Management of Bladder Cancer

Abstract: IN recent years, there have been important advances in our understanding of the biology of bladder cancer. They have been achieved with the use of new experimental models, the study of oncogenes in bladder cancer, and the demonstration of a wide range of functional heterogeneity in populations of morphologically identical bladder cancer cells. The development of new techniques of management — including diagnosis and staging, the use of intravesical chemotherapy and preemptive (neoadjuvant) intravenous chemotherapy, and the application of new monoclonal antibodies — appears to be yielding higher rates of response, prolonged disease-free survival, and perhaps even improved rates of . . .

The epidermal growth factor receptor and the prognosis of bladder cancer

Abstract: Epidermal growth factor is found in high concentrations in urine, and its receptor (EGFr) has been identified in certain bladder tumors. This study was performed to determine whether receptor positivity in the tumor was associated with a poor clinical outcome. One hundred one patients with newly diagnosed bladder cancer were studied prospectively by immunohistochemical staining for the EGFr. There were 76 men and 25 women, with a mean follow-up of 30 months; 49 had tumors invading muscle: 18 were pTl (tumor invading lamina propia) and 34 were pTa (tumor confined to urothelium). Strong staining for the EGFr was found in 48% of tumors and was associated with high stage (P less than 0.001). Death of bladder cancer (40 of 101) was associated independently with high stage (P less than 0.0001) and EGFr positivity (P less than 0.001). In patients with pTa and pTl tumors, EGFr positivity was associated with multiplicity (P less than 0.01), time to recurrence (P less than 0.03), and recurrence rate (P less than 0.004). Tumor progression was associated with EGFr positivity (P less than 0.0001) and multiplicity (P less than 0.05). EGFr were found on a significant proportion of bladder tumors: such tumors were more likely to result in death, recurrence, and progression.

Urinary bladder of rat: fine structure of normal and hypertrophic musculature

Abstract: The fine structure of the muscle of the urinary bladder in female rats is similar to that of other visceral muscles, although it is arranged in bundles of variable length, cross-section and orientation, forming a meshwork. When distended, the musculature is 100–120 μm thick, with some variation and occasional discontinuity. Extended areas of cell-to-cell apposition with uniform intercellular space occur between muscle cells, whereas attachment plaques for mechanical coupling are less common than in other visceral muscles. There are no gap junctions between muscle cells. Many bundles of microfilaments and small elastic fibres run between the muscle cells. After chronic partial obstruction of the urethra, the bladder enlarges and is about 15 times heavier, but has the same shape as in controls; the growth is mainly accounted for by muscle hypertrophy. The outer surface of the hypertrophic bladder is increased 6-fold over the controls; the muscle is increased 3-fold in thickness, and is more compact. Mitoses are not found, but there is a massive increase in muscle cell size. There is a modest decrease in percentage volume of mitochondria, an increase in sarcoplasmic reticulum, and no appreciable change in the pattern of myofilaments. Gap junctions between hypertrophic muscle cells are virtually absent. Intramuscular nerve fibres and vesicle-containing varicosities appear as common in the hypertrophic muscle as in controls. There is no infiltration of the muscle by connective tissue and no significant occurrence of muscle cell death.

Effect of bladder outlet obstruction on the morphology, physiology, and pharmacology of the bladder.

Abstract: Bladder outlet obstruction secondary to benign prostatic hyperplasia induces numerous changes in bladder morphology, physiology, and pharmacology. These changes have been studied experimentally in various animal models, and while each species has advantages and disadvantages, it is unclear which is most like man. It has been shown that tissue hypertrophy leading to an increase in tissue mass develops rapidly after bladder outlet obstruction. Ischemia induced by the obstruction results in acute muscle dysfunction. The degree of functional impairment is directly related to the degree of tissue hypertrophy. However, the bladder contractile apparatus appears to have a surprising regenerative ability, such that recovery of bladder function becomes obvious 14 days after obstruction. Urodynamic changes include an increase in urinary frequency and voiding pressure and a decrease in voided volume. Clinically, involuntary bladder contractions are often present. Determination of which of these specific aspects of outlet obstruction the investigator is interested in studying will dictate the selection of the most appropriate animal model.

A bladder-to-bladder cooling reflex in the cat.

Abstract: 1. Reflex effects of cold stimulation of the lower urinary tract were studied in cats anaesthetized with alpha-chloralose. The bladder and the urethra were catheterized for separate fluid instillations and the bladder pressure was monitored together with the evoked efferent nerve responses in pelvic nerve filaments. 2. A bladder cooling reflex could be evoked from both the bladder and the urethra. The response was an efferent discharge in preganglionic pelvic motor fibres to the bladder. 3. Bladder mechanoreceptors that drive the normal micturition reflex were not directly involved in the cooling reflex. Their tension sensitivity was decreased by cooling and the efferent reflex response typically occurred before any activation of these receptors. The efferent activity of the cooling reflex also survived an intentional unloading of the mechanoreceptors, a manipulation that abolishes the normal micturition reflex. 4. The dynamic threshold temperature of the cooling reflex was about 30-32 degrees C, which was at the thermal neutral point of the bladder in our experimental situation. 5. The bladder-evoked component of the reflex was greatly reduced or abolished by an intravesical infusion of the local anaesthetic Xylocaine. It was also abolished by total bladder denervation. 6. The vesical component of the reflex was unchanged by bilateral transections of the hypogastric nerves but abolished by pelvic nerve transection. The cooling reflex from the distal urethra was abolished by transection of the pudendal nerves. 7. It was proposed that the cooling reflex originates from cold receptors in the bladder and urethral walls and that the responsible afferent fibres are unmyelinated C fibres. The function of the reflex may be to rid the body of a thermal ballast when under cooling stress.

Nerve fibre proliferation in interstitial cystitis.

Abstract: The aetiology of pain in interstitial cystitis is not understood, although it has been reported to be due to release of mediators from mast cell granules Cystolysis and intravesical instillation of dimethyl sulphoxide have been shown to relieve pain in this condition We have studied the nerve population within the bladder wall using immunohistochemical stains for protein gene product 95 A group of 18 cases of chronic interstitial cystitis and 12 controls; neuropathic bladder (n=1), chronic bacterial cystitis (n=3), systemic lupus erythematosus cystitis (n=2) and normals (n=6), were investigated There were significantly more nerve fibres within the sub-urothelial and detrusor muscle layers in chronic interstitial cystitis than there were in normals Patients with chronic cystitis of other aetiology did not have a significant increase in nerve fibre density within the bladder wall suggesting a specific association between nerve fibre proliferation and interstitial cystitis Cystolysis is shown to deplete selectively the submucosal nerve plexuses without altering the nerve density within detrusor muscle This finding explains the desensitisation of the bladder without impairment of detrusor function after this procedure

Carcinogen Hemoglobin Adducts, Urinary Mutagenicity, and Metabolic Phenotype in Active and Passive Cigarette Smokers

Abstract: In 100 healthy volunteers, we have studied the relationship between the type (air- or flue-cured) and number of cigarettes smoked and different biomarkers relevant to the risk of bladder cancer, including the levels of 4-aminobiphenyl (ABP) hemoglobin adduct (a marker of internal dose), urinary mutagenicity in Salmonella typhimurium TA98, and the N-acetylation phenotype (a marker of susceptibility). ABP is a potent bladder carcinogen that is N-acetylated as an overall detoxification step. Levels of the ABP hemoglobin adduct were higher in smokers of black tobacco (air-cured) than in smokers of blond tobacco (flue-cured), confirming our earlier study. In addition, "slow" acetylators had higher levels of the ABP hemoglobin adduct for the same type and quantity of cigarettes smoked. Urinary mutagenicity was also associated with quantity of cigarettes but not with the acetylation phenotype. Convex dose-response relationships were found between the amount smoked and ABP hemoglobin adduct levels or urinary mutagenicity. In 15 nonsmokers who reported exposure to environmental tobacco smoke, ABP hemoglobin adduct levels, unlike urinary mutagenicity, were found to be an aspecific exposure indicator.

Caffeine: Does it Affect your Bladder?

Abstract: Summary— Patients with symptoms of frequency and urgency often complain that their symptoms are exacerbated by tea or coffee. A series of 20 women with confirmed detrusor instability and 10 asymptomatic women were given 200 mg of caffeine citrate and urodynamic studies were performed. In the group with detrusor instability there was a statistically significant increase in detrusor pressure on bladder filling following administration of caffeine, but no difference in volume at first contraction, height of contraction or bladder capacity. Normal women had no abnormality on cystometry.

Morphological plasticity in efferent pathways to the urinary bladder of the rat following urethral obstruction

Abstract: Partial urethral ligation in female Wistar rats produces changes in the neural control of the lower urinary tract including bladder hyperactivity and facilitation of a spinal micturition reflex pathway. To gain insight into the mechanisms underlying these changes, axonal tracing studies were conducted to examine the postganglionic efferent limb of the micturition reflex pathway which originates in the major pelvic ganglion (MPG). Forty microliters of the tracer Fluoro-Gold (4%) were injected into the right side of the bladder in urethral-obstructed (n = 10) and control (n = 4) rats 6 weeks after urethral ligation or sham surgery. As a control Fast blue (40 microliters, 5%) was injected into the colon to label neurons in the MPG innervating the intestine. Obstructed rats exhibited a 6-fold increase (p less than 0.001) in bladder weight (0.848 gm) compared to controls (0.148 gm). A significant increase (p less than 0.001) in the size of labeled bladder postganglionic neurons in the MPG was noted in obstructed rats (576.4 microns 2, n = 4) as compared to controls (299.6 microns 2). However, labeled, colon postganglionic neurons in the MPG in obstructed (312.9 microns 2) rats were not enlarged compared to controls (359.4 microns 2). Neuronal hypertrophy was not associated with a change in the number of labeled MPG neurons in control and obstructed groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypertrophy of visceral smooth muscle.

Abstract: Smooth muscles of viscera undergo a large increase in volume when there is a chronic, partial obstruction impairing the flow of lumenal contents. Hypertrophy of smooth muscle occurs in various medical conditions and several methods are available for inducing it experimentally in laboratory animals, especially in urinary bladder, small intestine and ureter. The hypertrophic response differs somewhat with the type of organ, the animal species, the age of the subject, and the experimental procedure. Ten- to fifteen-fold increases in muscle volume develop within a few weeks in the urinary bladder or the ileum of adult animals, a growth that would not have occurred in the lifespan of the animal without the experimental intervention. The general architecture of the muscle and the boundaries with adjacent tissues are well preserved. In intestinal hypertrophy, muscle cells increase in number: mitoses are found in mature, fully differentiated muscle cells. Cell division by full longitudinal splitting of muscle cells may also occur. Enlargement of muscle cells accounts for most of the muscle hypertrophy. The hypertrophic muscle cell has an irregular profile with deep indentations of the cell membrane, bearing caveolae and dense bands; however, the cell surface grows less than the cell volume (reduction of surface-to-volume ratio). The nucleus is crenated and is much less enlarged than the cell (reduction of the nucleo-plasmatic ratio). Mitochondria grow in number but in some muscles their spatial density decreases; intermediate filaments increase more than myofilaments. The spatial density of sarcoplasmic reticulum is generally increased. In the hypertrophic intestine, gap junctions increase in number and size; in the bladder, gap junctions are absent both in control and in hypertrophy. Thus the hypertrophic muscle cell is not only larger than a control cell, but has a different pattern of its structural components. Extensive neo-angiogenesis maintains a good blood supply to the hypertrophic muscle. The density of innervation is much decreased in the hypertrophic intestine, whereas it appears well maintained in the bladder. Neuronal enlargement is found in the intramural ganglia of the intestine and in the pelvic ganglion. The mechanisms involved in hypertrophic growth are unknown. Three possible factors, mechanical factors, especially stretch, altered nerve discharge, and trophic factors are discussed.

Postirradiation changes in the pelvis: assessment with MR imaging.

Abstract: Magnetic resonance (MR) imaging features of pelvic radiation change were assessed in 51 patients and were correlated with tumor and critical tissue radiation dose, time after treatment, and clinical symptoms. The severity of MR tissue changes was graded. Radiation tissue toxicity increased significantly when the dose exceeded 4,500 cGy, with the incidence of marked bladder and rectal changes rising from 8% to 51% and from 24% to 48%, respectively. Similar dose-related changes were seen in other pelvic organs. All grades of tissue change were seen in the bladder and rectum regardless of the time from start of therapy. All patients who exhibited clinical grade 2 or 3 bladder and rectal changes showed moderate or severe changes on MR images. In asymptomatic patients, minimal MR changes were seen in the bladder (47%) and in the rectum (33%). The accuracy of MR imaging in differentiating between radiation damage and residual/recurrent tumor varied with the primary tumor site, being excellent for recurrent cervical cancer and less so for rectal carcinoma.

Pseudosarcomatous myofibroblastic proliferations in the urinary bladder of children.

Abstract: Ten examples of a pseudosarcomatous myofibroblastic proliferation occurring in the urinary bladder of children (aged 2 to 16 years) are reported. The lesions appeared as polypoid nodular masses of variable size with myxoid and hemorrhagic areas. They consisted of compact fascicles of elongated spindle cells with minimal atypia. Myxoid areas of variable extension and scattered inflammatory cells were constant features, whereas diffuse collagen deposition was not common. Despite the striking cellularity of some of the lesions, most showed minimal mitotic activity. Ultrastructurally, the predominant cells had features of myofibroblasts. Six cases studied by immunocytochemical methods expressed vimentin and muscle-specific actin. In addition, two of these cases expressed desmin and two others cytokeratin. Infiltration into the muscularis propria of the urinary bladder was demonstrated in six cases and into the perivesical soft tissues in two. However, none of the eight patients for whom follow-up information is available has had local recurrence or metastasis develop 18 months to 6 years after surgical excision.

The various types of neurogenic bladder dysfunction: an update of current therapeutic concepts

Abstract: Increased experience with treatment strategies developed during the last 10 years in the field of neurourology justifies an update of current therapeutic concepts. Based on a rather simple, but clinically useful, classification of detrusor-sphincter dysfunction the therapeutic concepts now available for four prototypes of detrusor-sphincter dysfunction are discussed. (1) For the combination of a hyperreflexive detrusor with a hyperreflexive (spastic) sphincter, characteristic for the reflex- and the uninhibited neuropathic bladder, detrusor-sphincter dyssynergia (DSD) is still the greatest problem, and transurethral sphincterotomy is the method of choice if this situation cannot otherwise be managed. One concept is to convert detrusor hyperreflexia into hyporeflexia by adequate pharmacotherapy, which is nowadays available, and to assist or to accomplish bladder emptying by clean intermittent (self-) catheterisation (CIC) with the advantage of dry intervals in between. Japanese colleagues recommend bladder overdistension during the spinal shock phase to achieve detrusor hyporeflexia, but this procedure is rather decisive at an early stage of the disability, leaving the detrusor no chance for further rehabilitation. Another possibility is rhizotomy of the sacral posterior roots to eliminate detrusor hyperreflexia, and the simultaneous implantation of a sacral anterior root stimulator (Brindley) to achieve electrically induced micturition. From our personal experience with 12 patients this concept is ideal for female patients with unbalanced reflex bladder and otherwise uncontrollable reflex incontinence. (2) The combination of a weak detrusor with a spastic sphincter is a clear indication for CIC, as the bladder is emptied regularly, and due to the spastic sphincter, the patient stays continent as long as controlled fluid intake prohibits overflow incontinence. The implantation of an anterior sacral root stimulator is an alternative approach provided that at least weak reflex detrusor contractions are present. (3) With the combination of an areflexive or hyporeflexive detrusor and a flaccid pelvic floor, passive voiding by abdominal straining or by the Crede manoeuvre is usually recommended, but should be replaced by CIC if this mechanism of bladder emptying creates unphysiological high and dangerous intravesical pressures, or if vesico-uretero-renal reflux is present. Neurogenic urinary stress incontinence is usually associated with this type of lesion and can be successfully treated by the implantation of an artificial urinary sphincter (Scott). However in two thirds of the patients with neurogenic bladder dysfunction, additional, usually operative treatment is necessary to meet the criteria for implantation. Moreover, a 30% rate of repair operations must be accepted by patients, but is becoming less frequently required with an improved design of the device.(ABSTRACT TRUNCATED AT 400 WORDS)

The histology of interstitial cystitis.

Abstract: Several studies have reported histologic findings in interstitial cystitis (IC) bladder biopsy specimens. However, these studies used a variety of criteria to define IC, which may explain the variation noted in the histologic changes. Clinical experience shows that these biopsy specimens are often not helpful in confirming the diagnosis. Our study was designed to examine the histologic features identified in bladder biopsy specimens from patients with IC and compare them with biopsy specimens from a control population. Although IC patients as a group had a higher incidence and degree of denuded epithelium, ulceration, and submucosal inflammation, none of these findings was pathognomonic. In addition, these findings occurred only in interstitial cystitis patients with pyuria or small bladder capacity. The inflammatory infiltrate seen in IC was composed predominantly of lymphocytes, with increasing numbers of plasma cells as the degree of inflammation increased. There was no specific predilection for the inflammatory infiltrate to be perineural. Submucosal inflammation was associated with denuded epithelium, ulceration, pyuria, and a clinical response to therapy suggesting a pathophysiologic relationship. Epithelial and basement membrane thickness, submucosal edema, vascular ectasia, fibrosis, and detrusor muscle inflammation and fibrosis were not significantly different in the IC and control patients. These findings suggest that IC is a chronic submucosal inflammatory disease, at least in those patients with small bladder capacities or pyuria. IC is best diagnosed from its clinical features; the histologic changes identified in the bladder biopsy play a supportive role in this diagnosis. Mast cells play a limited role in the diagnosis of IC.