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At least 19 recordsLinked to original sources
PubMed1990

Mechanical properties of the urethra in healthy and stress incontinent females: dynamic measurements in the resting urethra.

The relationship between pressure and cross-sectional area in the resting urethra during its inflation and deflation was examined in 30 healthy females and in 30 patients with genuine stress incontinence (GSI). Measurements were performed at the bladder neck, in the high-pressure zone and distally in the urethra. The mechanical properties of the urethra were found to vary significantly as a function of time after induction of a cross-sectional area (stress episode) in both groups of women. The pattern of response of the urethra showed significant differences between normals and GSI particularly during dynamic conditions. Our results indicate that mechanical laxity of the urethra at the bladder neck and midurethrally especially at dynamic events (stress episodes) is of pathophysiological importance in GSI.

Adult↗
PubMed1978

Reappraisal of the sympathetic role in the sphincteric urethra. Denervation supersensitivity of the urethra of the chronic neurogenic bladder to alpha-adrenergic drugs.

The response of urethral pressure to administration of an alpha-stimulant was compared between a group of eight patients with chronic neurogenic bladders as evidenced by positive denervation supersensitivity to parasympathomimetic bethanechol chloride and a group of ten control patients. A supersensitive response to administration of an alpha-stimulant with a rise of maximum urethral pressure, 10 mm Hg or more above the control urethral pressure, was uniformly observed in the urethra of patients with chronically denervated bladders. Our results appear to add pharmacologic evidence of alpha-adrenergic predominance over the parasympathetic in the urethra which is believed to be innervated dually in the recently envolving new concept.

Adolescent↗
PubMedDate not supplied

[The surgical treatment of closed injuries and strictures of the urethra].

Under analysis were results of operative treatment of 291 patients aged from 7 to 76 years with traumas and strictures of the urethra at the period from 1970 to 1990. Totally 325 operations have been performed. The primary suture of the urethra was successfully used in 8 of 36 patients with trauma of the urethra. Tunneling of the urethra for its strictures which was widely used in the clinic up to 1980 gave 46.2% of recurrences during the first 3 months after operation. It required the surgical methods to be changed. During the recent 11 years 161 operative interventions have been performed: 103 (64.0%) resections of the urethra, 45 (28.0%) internal optical urethrotomies and transurethral resections (TUR) of scarry tissues, 7 (4.3%) epidermoplasties of the urethra and 6 (3.7%) tunnelings of the urethra. The amount of recurrences dropped up to 13.7%. The primary suture of the urethra is necessary for penetrating ruptures of the urethra if the patient's state allowed. Resection of the urethra must be the operation of choice in patients with strictures and obliteration of the urethra. The endoscopic methods of treatment (urethrotomy and TUR) are indicated for short strictures and scarry deformity of the posterior urethra after operations on the prostate. The epidermoplasty is expedient for lengthy strictures.

Adolescent↗
PubMed1991

Development of the human anterior urethra.

To further our understanding of the development of the anterior urethra a series of 38 normal human fetuses ranging from the end of the embryonic period proper to the third trimester of gestation were studied. Tissues prepared as serial histological sections were examined and appropriate specimens were reconstructed. The formation of the bulbar and spongy urethra occurred by proliferation of mesenchyme underlying the epithelium of the urethral folds, causing the creation of a tubular urethra by epithelial fusion in the ventral midline. The tubular urethra becomes invested by mesenchyme, the future corpus spongiosum. This process of fusion of the urethral folds extends to the glans penis. At this period of development the glans contains the urethral plate, a lamina of epithelium lacking a lumen. The mechanism of the subsequent connection of the spongy urethra to the canalized urethral plate has been the point of controversy. Our observations support the idea that 3 processes must act in synchrony to produce successful completion of the anterior urethra: 1) the prepuce forms by overgrowing the glans due to proliferation of the penile skin and subcutaneous tissues, and in so doing it continues the progression of closure of the urethral folds into the glans and forms the frenulum by its fusion on the ventral aspect, 2) the mesenchyme surrounding the prolongation of the urethra fuses with the mesenchyme of the glans, which before this time had existed as a mesenchymal structure distinct from the corpus spongiosum or corpus cavernosum and 3) the epithelium of the urethral plate within the glans, which underlies the epithelial tag, becomes canalized and develops continuity with the lumen of the spongy urethra.

Humans↗
PubMed1978

Differences in postsynaptic alpha-adrenoceptor populations between isolated cat urethra and various other isolated tissues.

This study was undertaken with the aim of determining whether the postsynaptic alpha-adrenergic receptor population of the cat urethra differed from that of other isolated tissues (rabbit aorta and rat vas deferens) and if so the possibility of selectively affect these receptors. For this purpose the substances 2-methylammonio-1-(spiro[cyclopentane-1,1'-indene]-3'-yl)ethanol (KABI 2023), noradrenaline (NA) and dopamine (DA) were used. KABI 2023 and NA acted as full agonists on all three tissues investigated. DA was a full agonist on the vas deferens but was almost inactive on urethra. The contractile response of urethra to KABI 2023 was of an alpha-adrenergic nature, as it could be blocked with phentolamine. Compared with NA, KABI 2023 showed a 10 times higher selectivity for the receptors of urethra than for those of aorta. Affinity constants (log KB) for phentolamine and haloperidol with use of the various agonists were estimated. The affinity of phentolamine was found to be significantly different when using NA and KABI 2023 as agonists on the urethra but not on the aorta. Corresponding findings were obtained with haloperidol. On the vas deferens a greater difference in log KB values than that on the urethra was found. On the basis of the results, it is suggested that the population of postsynaptic alpha-adrenoceptors in the urethra (cat) differs from that in the aorta (rabbit). On the vas deferens a heterogenicity of postsynaptic receptors seem to exist which makes the interpretation of the results more difficult on this organ. In the presence of phentolamine and haloperidol the maximum responses to NA were potentiated on the aorta and vas deferens, but not on the urethra. Investigations to evaluate this difference are now in progress.

Animals↗
PubMed1976

[The neutropathic urethra: urethrogram and pathophysiologic aspects (author's transl)].

In the analysis of neurogenic urinary voiding disturbances, too much attention has been paid to the bladder, too little to the muscular tubing of the posterior urethra and to the pelvic floor. Contrast radiography of the urethra in injection and micturition, combined with urodynamic investigations, seemed suitable for comprehension of neurogenic functional disturbances of the posterior urethra and the pelvic floor. A cross section of 143 predominantly traumatic patients and 69 patients with myelomeningocele were investigated radiologically. In addition, in a number of patients urinary flow was determined by uroflowmetry and micturition studies with simultaneous recording of intravesical and intrarectal pressure, of the EMG-activity of the pelvic floor and urinary flow were performed by a special method. The radiologic section (I) shows that the urinary picture of various neurogenic bladder types are characterized by specific changes in form of the posterior urethra. With the help of systematic investigations of a number of cases it was demonstrated that in automatic bladder the roentgen contour of the urethra changes with duration of illness and that primarily secondary, morphologic changes-recognizable at the same time from the increasing number of radiologically demonstrable changes of the prostate and the seminal vesicles-are responsible. Simultaneously a typical deformation of the posterior urethra in passive urinary voiding is described, and attention directed to the fact that the urinary pictures of children with neurogenic impaired urethra sometimes cannot be distinguished from those with urethral values. Urinary flow measurements (II) show that the flow rates from a cross section of patients with lesions of the upper and lower neurons are significantly lower in comparison to normals. With the help of combined urodynamic investigations (III) it was demonstrated that a functional obstruction was present in the neurogenic bladder at the level of spastic and of paretic pelvic floors. It was proved that the roentgenologically visible deformation of the posterior urethra plays a quite decisive role in neurogenically disturbed urinary voiding. It is the main reason why, despite sufficient bladder pressure values, urinary voiding remains unsatisfactory and urinary performance low. Hence the therapeutic consequence follows: an improvement in urinary performance in neurogenic bladder is generally only possible through a decrease in the expulsion resistance. Various operative procedures for the release of bladder outlet obstruction and their uses are discussed.

Adult↗
PubMed1992

Surgical anatomy of the male and female urethra.

The urethra is lined by transitional and stratified columnar epithelium. The urethra can be divided into both anatomic (prostatic, membranous, bulbar, and pendulous) and functional (anterior and posterior) segments. In the male, the anterior urethra is contained within the corpus spongiosum and penis. The urethra in the male and female is located within the urogenital triangle and pierces the superficial and deep perineal spaces of the pelvic floor. The urethra is surrounded by perineal and pelvic musculature that provide support and also form the urethral sphincter mechanism. Cancers of the anterior urethra preferentially drain into superficial inguinal lymph node channels. Those of the posterior urethra (prostatic, membranous, and bulbar segments in the male and the proximal two thirds of the urethra in the female) generally drain into pelvic lymphatic channels. A thorough knowledge of urethral and regional anatomy allows for complete tumor excision, optimal reconstruction, and in selected cases, restoration of urinary tract function.

Female↗
PubMed1977

[Neurogenic urethra. Urethrogram and pathophysiological aspects].

In the analysis of neurogenic urinary voiding disturbances, too much attention has been paid to the bladder, too little to the muscular tubing of the posterior urethra and to the pelvic floor. Contrast radiography of the urethra in injection and micturition, combined with urodynamic investigations, seemed suitable for comprehension of neurogenic functional disturbances of the posterior urethra and the pelvic floor. A cross section of 143 predominantly traumatic patients and 69 patients with myelomeningocele were investigated radiologically. In addition, in a number of patients urinary flow was determined by uroflowmetry and micturition studies with simultaneous recording of intravesical and intrarectal pressure, of the EMG-activity of the pelvic floor and urinary flow were performed by a special method. The radiologic section shows that the urinary picture of various neurogenic bladder types are characterized by specific changes in form of the posterior urethra. With the help of systematic investigations of a number of cases it was demonstrated that in automatic bladder the roentgen contour of the urethra changes with duration of illness and that primarily secondary, morphologic changes--recognizable at the same time from the increasing number of radiologically demonstrable changes of the prostate and the seminal vesicles--are responsible. Simultaneously a typical deformation of the posterior urethra in passive urinary voiding is described, and attention directed to the fact that the urinary pictures of children with neurogenic impaired urethra sometimes cannot be distinguished from those with urethral values. Urinary flow measurements show that the flow rates from a cross section of patients with lesions of the upper and lower neurons are significantly lower in comparison to normals. With the help of combined urodynamic investigations it was demonstrated that a functional obstruction was present in the neurogenic bladder at the level of spastic and of paretic pelvic floors. It was proved that the roentgenologically visible deformation of the posterior urethra plays a quite decisive role in neurogenically disturbed urinary voiding. It is the main reason why, despite sufficient bladder pressure values, urinary voiding remains unsatisfactory and urinary performance low. Hence the therapeutic consequence follows: an improvement in urinary performance in neurogenic bladder is generally only possible through a decrease in the expulsion resistance. Various operative procedures for the release of bladder outlet obstruction and their uses are discussed.

Female↗
PubMed1989

The morphogenesis of human sphincter urethrae muscle.

The morphogenesis of the sphincter urethrae muscle was studied in human ontogeny. Muscles of 65 embryos and fetuses, 7 newborns, 3 children and 3 adults of both sexes were examined histologically and by means of microdissection. Three developmental stages can be recognized in terms of morphogenetic events, histogenesis and development of sexual dimorphism. In the sexually indifferent stage (up to approximately 50 mm crown-rump length), the sphincter urethrae primordium is formed by a shallow arch apposed only to the ventrolateral wall of the urethra. The primordium extends from the level of the urogenital diaphragm up to the vesicourethral transition. It consists of a condensation of mononuclear cells. Myotubes appear in fetuses of 30 mm crown-rump length. During the second stage (until birth) sexual dimorphism develops in conjunction to the formation of the prostate and vagina. In this stage, the sphincter urethrae muscle fibres gradually extend to the posterior wall of the urethra. At the same time cranially situated muscle fibres project to the lateral wall of the prostate, whereas in females caudally located muscle fibres attach to the lateral wall of the vagina. In this way the sphincter achieves the sexually distinct form. The definitive arrangement develops in the third morphogenic stage (after birth), in which a complete muscle ring is formed by encircling the urethra in the infraprostatic part in males and in the upper, larger part of the sphincter in females. The sphincter urethrae muscle is located inside the sling of the puborectalis muscle in both sexes, but no muscle fibres connect them to one another.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1992

Comparative autonomic responses of the cat and rabbit bladder and urethra.

The cat and the rabbit have both been utilized extensively in the study of lower urinary tract function. Previous studies have demonstrated that although both the cat and rabbit bladder are approximately the same weight, the in-vitro cat bladder can generate over 6 times the intravesical pressure of the rabbit bladder. The current study was designed to compare the ability of the isolated bladder to generate pressure with the pressures required to maintain flow through the isolated urethra for both the cat and the rabbit. The results can be summarized as follows. 1) The cat bladder is visibly much thicker than the rabbit bladder, and in vitro cystometry demonstrates that it is far less compliant than the rabbit bladder. 2) Over 20 cm.H2O pressure is required to begin flow through the isolated cat urethra preparation, whereas 5 cm.H2O begins flow through the rabbit urethra. 3) Increasing the flow rate (up to 7-fold) through both the isolated cat and rabbit urethra increases intraurethral pressure only slightly. 4) Both the isolated cat and rabbit urethra respond strongly to field stimulation and alpha-adrenergic stimulation (relative to the opening pressure required to begin flow), but not to cholinergic stimulation. 5) Field stimulation following pre-stimulation by methoxamine induces a strong relaxation of the pre-stimulated cat urethra, but an additive contraction in the pre-stimulated rabbit urethra. These studies demonstrate that in order for the cat to empty its bladder, it must generate a comparatively high intravesical pressure, whereas the rabbit is required to generate a relatively low intravesical pressure.

Animals↗
PubMed1985

The adult human female urethra. Enzyme-histochemical study.

In the female urethra, the activity and distribution of 15 enzymes was determined by using both conventional and special histochemical methods. The enzymatic equipment differed according to the type of epithelial lining whose variation is characteristic for the female urethra. In the stratified squamous epithelium of the urethra, alkaline phosphatase, beta-glucuronidase, acetyl-beta-D-glucosaminidase, thiamine pyrophosphatase, and glucose-6-phosphatase exhibited but minimal or no activity, yet the other 10 enzymes studied displayed activity particularly in basally situated cells. Nearer to the lumen of the urethra, the activity in the epithelium kept decreasing and was mostly absent in superficial and desquamated cells. In the pseudostratified columnar and in the transitional epithelium of the urethra, the majority of enzymes showed an evenly distributed activity at all epithelial levels. In the apical parts of the most superficially situated cells bounding the lumen of the urethra, a distinct narrow zone of higher activity was observed. It was seen not only on determining the majority of dehydrogenases but also on examining acid phosphatase and naphthyl esterase. The endocrine cells occurring in the uroepithelial lining of the female urethra displayed, yet always with the exception of squamous epithelium (Zaviacic et al. 1983), distinct activity of acid hydrolytic enzymes, and of the enzymes studied it was particularly acid phosphatase. The majority of the demonstrated enzymes, of the dehydrogenases priority, is to be given to succinate dehydrogenase, enabled to differentiate readily between the highly active striated muscle fibers located in the most peripheral parts of the excisions along the urethral circumference and the smooth musculature of the urethral wall with a lower or only minimal activity.

Acetylglucosaminidase↗
PubMed1989

Pharmacological comparison of the isolated whole urethra model to urethral strip methodology.

Urethral strips provide a sensitive method for quantitative pharmacology; however, it is not clear if the physiological response of the whole urethra to pharmacological agents can be extrapolated from these data. The intent of this study was to investigate whether the linear contraction of strips is consistent with the ability of the intact urethra to alter resistance to flow. To measure the effect of drugs on the ability of the intact urethra to alter resistance to flow in the absence of endogenous influences, we developed an in vitro whole rabbit urethra model. We characterized the effect of norepinephrine in the absence and presence of alpha-adrenergic antagonists (prazosin, yohimbine, and LY253352) on intraurethral pressure which was measured during constant saline infusion using a Statham pressure transducer. We compared this to the contractile function of urethral strips. The pA2 values for alpha-adrenergic antagonists, LY253352, prazosin, and yohimbine were 8.17 +/- 1.5, 6.49 +/- 1.2, and 5.58 +/- 0.9, respectively, as determined in the whole urethra. The pA2 values for these antagonists determined in urethral strips were as follows: LY253352 8.72 +/- 1.2; prazosin 7.52 +/- 1.5, and yohimbine 5.6 +/- 0.84. Pharmacologically, the whole urethra model and isolated strips appeared to respond similarly to alpha-adrenergic agonists and antagonists, and thus both models would be suitable for pharmacological studies on the normal urethra.

Animals↗
PubMed1992

Oncogenic human papillomavirus type 16 is associated with squamous cell cancer of the male urethra.

Human papillomaviruses (HPV), especially genotypes 16 and 18, are probable effectors of human urogenital malignancies. Although the male urethra is a proposed reservoir of HPV transmission, the association between HPV and squamous cell carcinoma (SCC) of the male urethra has not been studied. The highly sensitive technique of polymerase chain reaction with type-specific HPV 16 and 18 primers and general primers, including nine other genotypes was used to survey a series of SCC of the male urethra for the prevalence of an association with HPV. Archival surgical specimens from 14 patients were analyzed, and primary, recurrent, and metastatic lesions from 4 (29%) patients contained HPV 16 DNA. No other HPV genotype (6b, 11, 13, 18, 30, 31, 33, 35, 45, 51) was detected. Complete concordance for the presence of HPV in primary and recurrent or metastatic disease was demonstrated. These findings strongly suggest that HPV type 16 is associated with a substantial subset of SCCs of the male urethra. Analysis of clinical data revealed that HPV-positive tumors had a significant predilection for location in the pendulous urethra versus the bulbar urethra. Survival data analysis showed that the presence of HPV more closely correlated with prolonged survival than did tumor location. The presence or absence of HPV 16 DNA defines two subsets of SCC of the male urethra which differ in the site of occurrence and, possibly, progression.

Base Sequence↗
PubMed1977

Duplication of the male urethra.

Our experience with 4 male subjects with accessory urethras is reported. The anatomic types, clinical presentations and treatment modalities of urethral duplication are discussed. Our scrutiny of all cases reviewed in the literature led us to classify patients into 3 types, depending upon the anatomic and embryologic features. Type 1 is a complete accessory urethra arising from a separate or confluent opening within the bladder and extending to an external orifice. Type 2 includes accessory urethras that arise from the primary urethra and may or may not extend to a distal orifice. Type 3 is the most unusual anomaly, in which 1 of the duplicated urethras arises from the bladder or proximal urethra and opens onto the perineum.

Adult↗
PubMed1989

[Definition and etiologic factors of hypotonic urethra in relation to urinary stress incontinence in the female].

In 555 stress-induced urinary incontinent and 119 continent women patients, we studied the history, clinical and urodynamic investigations to define the hypotonic urethra and to find out important etiological factors of the low urethral closure pressure. The linear depression of the urethral pressure and the urethral closure pressure at rest--well known from literature--has been confirmed in this study. With hypotonic urethra, closure pressure values were found to be below the simple standard deviation from a norm-curve. Also, in cases of stress urinary incontinence, we found a nearly linear depression of closure pressure. The stress incontinent patients could be divided in two groups: 46% with hypotonic urethra, 54% with nearly normal closure pressure. History of former incontinence surgery, but also of other operations such as simple abdominal or vaginal hysterectomy, is correlated with low urethral closure pressure. The degree of closure pressure is correlated with shortening of the functional urethral length. The maximum closure pressure shifts distally. Women, who, despite hypotonic urethras, are continent, build up a positive closure pressure throughout a broad zone of the functional urethral length. Contrarily, in the case of incontinent patients, even a weak coughing spasm, which does not even break through the bladder sphincter in maximum closure, can cause opening of the urethra and establishment of pressure equilibration between bladder and urethra.

Adult↗