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PubMed2004

Microbiology of the urethra and perineum and its relationship to bacteriuria in community-residing men with spinal cord injury.

OBJECTIVE: Reasons why some persons with spinal cord injury (SCI) experience recurrent urinary tract infections more than others are poorly understood. We performed a prospective study of bacterial flora of the urethra and perineum in men with and without bacteriuria to understand more completely the relationship between bacterial colonization and invasion of the urinary tract. METHODS: Urine, urethra, and perineum cultures were obtained from 70 men. Microbial flora of these sites was compared for men with and without bacteriuria. RESULTS: Urine colony count was 0 in 16 (22.9%) men. Perinea in 2 men (12.5%) and urethras in 6 men (37.5%) were colonized with various gram-negative bacilli, enterococci, and/or Staphylococcus aureus. Among 54 (77.1%) men with bacteriuria, uropathogens were shown in the perineum in 31 (57.4%) and in the urethra in 46 (85.2%). In 40 (74.1%) of men with bacteriuria, at least one bacterial species present in the urine was also found in the urethra and/or perineum. Differences in the occurrence of uropathogens in men with and without bacteriuria were statistically significant, and organisms were present in higher numbers in men with bacteriuria. CONCLUSION: Men with SCI who have bacteriuria are significantly more likely to be colonized in the distal urethra and perineum with uropathogens that are often present in the urine in comparison with men without bacteriuria.

Adult↗
PubMed1997

Involvement of the anterior urethra in male patients with transitional cell-carcinoma of the bladder undergoing radical cystectomy with simultaneous urethrectomy.

Histological tumor extension into the prostate, urethra and ureters was examined in 52 specimens obtained by cystourethrectomy for transitional cell carcinoma of the bladder with one or more risk factors for urethral involvement. In four (21.1%) of 19 patients with diffuse carcinoma in situ in the bladder extending to the internal urethral orifice and prostatic urethra, the anterior urethra was affected by transitional cell carcinoma, including one specimen with invasion into the corpus spongiosum. However, none of 33 patients without these findings had synchronous anterior urethral transitional cell carcinoma involvement. It is recommended that patients with diffuse carcinoma in situ extending into the prostatic urethra undergo careful preoperative assessment of the anterior urethra before cystectomy. In other cases, the anterior urethra can be preserved and used for orthotopic neobladder replacement.

Adult↗
PubMed2000

Primary malignant melanoma of the urethra: a clinicopathologic analysis of 15 cases.

The clinical and pathologic features of 15 primary urethral melanomas occurring in patients (nine women and six men) age 44 to 96 years (mean age, 73 yrs) are described. In the men the tumor involved the distal urethra. In eight women it involved the distal urethra, usually the meatus; both the distal and proximal urethra were involved in one woman. The tumors were typically polypoid and ranged from 0.8 to 6 cm (mean, 2.6 cm) in maximum dimension. A vertical growth phase was present in all tumors, with a prominent nodular component in seven of them. A radial growth phase was seen in nine tumors. The depth of invasion ranged from 2 to 17 mm. The tumors had diffuse, nested, storiform, or mixed growth patterns. The neoplastic cells typically had abundant eosinophilic cytoplasm, large nuclei with prominent nucleoli, and brisk mitotic activity. Melanin pigment was seen in 12 tumors but was conspicuous in only six. At the time of diagnosis, 13 tumors were confined to the urethra and two patients had lymph node metastasis. Nine patients died of disease 13 to 56 months after initial diagnosis and treatment, and one patient had a local recurrence at 4 years and subsequently died of sepsis 1 year later. Three patients were alive and well at 11 months, 23 months, and 7 years. One patient died at the time of the initial operation, and one died of a ruptured aortic aneurysm at 3 years without evidence of melanoma at autopsy. Primary malignant melanomas of the urethra, one fifth of which are amelanotic, must be included in the differential diagnosis of a number of primary neoplasms that involve the urethra, including transitional cell carcinoma, sarcomatoid carcinoma, and sarcomas. Conventional prognostic factors, such as depth of invasion or tumor stage, do not seem to play as important a role in predicting survival as the mucosal location and the nodular growth present frequently in these tumors.

Adult↗
PubMed1975

The structure and innervation of smooth muscle in the wall of the bladder neck and proximal urethra.

Neurohistochemical and electron microscopic techniques have been employed to compare the structure and autonomic innervation of the bladder detrusor with that of the bladder neck and urethra in male and female cats, rats and guinea-pigs. In all specimens the structure and arrangement of smooth muscle in the detrusor was different from that in the bladder neck and proximal urethra. In male specimens this circular smooth muscle extended into the proximal urethra as far as the entrance of the ejaculatory ducts. A similar muscle coat was less well developed in the female but could be identified along the length of the urethra. Differences in the distribution of autonomic nerves have also been demonstrated. Presumptive cholinergic nerves were frequently encountered amongst the smooth muscle cells of the detrusor whilst noradrenergic nerves were relatively sparse. In contrast, muscle in the bladder neck and urethra was richly innervated by both types of autonomic nerve. In the male these findings are considered to provide support for the concept of a sphincteric mechanism which prevents retrograde ejaculation. In both sexes the possible functional role of the autonomic innervation of the bladder neck and proximal urethra during micturition has also been discussed.

Animals↗
PubMed2006

Pudendal nerve stimulation of a preparation of isolated guinea-pig urethra.

OBJECTIVE: To assess the functional response of the urethral striated muscle to activation of its nerves, using a novel isolated organ-bath preparation. MATERIALS AND METHODS: The urethra of the female guinea-pig was chosen as a suitable model for investigation, as it is functionally and structurally similar to the human urethra. Female Dunkin-Hartley guinea-pigs (400-500 g) were used; for the histochemical and immunohistochemical experiments, unfixed urethras were cryo-sectioned (14 microm thick) and were stained using established methods. For in vitro experiments, whole urethras were suspended vertically, with pudendal nerves intact, for isometric tension and intraluminal pressure recording in a 40-mL organ bath. Drugs were applied directly to the bathing solution. RESULTS: In the striated muscle layer of the urethra there was positive beta-NADPH-diaphorase activity. In organ-bath studies the pudendal nerve-evoked contractions (0.2 ms pulses, 5 s trains, 70 V and 1-100 Hz) were abolished in the presence of tubocurarine (10(-6)m), and unaffected by guanethidine and atropine (both 10(-6)m). Pre-incubation with sodium nitroprusside and SIN-1 chloride significantly reduced the initial peak pressure responses (P < 0.05, anova for paired data) evoked by electrical field stimulation of the pudendal nerves at stimulus parameters of 0.2 ms pulses, 5 s trains, 70 V and 25 Hz. CONCLUSION: Electrically induced contractions were abolished by tubocurarine, confirming that the pudendal nerve innervates the striated muscle of the guinea-pig external urethral sphincter via nicotinic receptors. beta-NADPH-diaphorase histochemistry gave positive staining around guinea-pig striated muscle cells and possibly identified neuromuscular junction sites staining positively for the nitric oxide synthase marker. Together with the results of the organ-bath experiments, the results suggest that the striated muscle cells of the guinea-pig urethra have the machinery to respond to nitric oxide.

Action Potentials↗
PubMed2006

Kit-positive interstitial cells in the rabbit urethra: structural relationships with nerves and smooth muscle.

OBJECTIVE: To identify interstitial cells (ICs) in the wall of the rabbit urethra using antibodies to the Kit receptor, and to examine their location, morphology and relationship with nerves and smooth muscle cells (SMCs), as studies of enzymatically isolated cells from the rabbit urethra have established that there are specialized cells that show spontaneous electrical activity and have morphological properties of ICs. MATERIALS AND METHODS: Urethral tissues from rabbits were fixed, labelled with antibodies and examined with confocal microscopy. Some specimens were embedded in paraffin wax and processed for histology. Histological sections from the most proximal third and mid-third region of rabbit urethra were stained with Masson's Trichrome to show their cellular arrangement. RESULTS: Sections from both regions had outer longitudinal and inner circular layers of SM, and a lamina propria containing connective tissue and blood vessels; the lumen was lined with urothelial cells. The mid-third region had a more developed circular SM layer than the most-proximal samples, and had extensive inner longitudinal SM bundles in the lamina propria. Labelling with anti-Kit revealed immunopositive cells within the wall of the rabbit urethra, in the circular and longitudinal layers of the muscularis. Double-labelling with an antibody to SM myosin showed Kit-positive cells on the boundary of the SM bundles, orientated parallel to the axis of the bundles. Others were in spaces between the bundles and often made contact with each other. Kit-positive cells were either elongated, with several lateral branches, or stellate with branches coming from a central soma. Similar cells could be labelled with vimentin antibodies. Their relationship with intramural nerves was examined by double immunostaining with an anti-neurofilament antibody. There were frequent points of contact between Kit-positive cells and nerves, with similar findings in specimens double-immunostained with anti-neuronal nitric oxide synthase (nNOS). CONCLUSION: Kit-positive ICs were found within the SM layers of the rabbit urethra, in association with nerves, on the edge of SM bundles and in the interbundle spaces. The contact with nNOS-containing neurones might imply participation in the nitrergic inhibitory neurotransmission of the urethra.

Animals↗
PubMed1986

Regional distribution of alpha-adrenoceptor subtypes in the female rabbit urethra.

The aim of the present investigation was to study the regional distribution of alpha-adrenoceptor subtypes in the female rabbit bladder base and urethra, using radioligand binding and mechanical activity studies. The binding studies performed on membranes prepared from the bladder base, and the proximal and distal part of the urethra, revealed that the number of alpha 1-adrenoceptors did not significantly differ between the three regions, whereas the number of alpha 2-adrenoceptors increased distally. The mechanical activity studies showed that noradrenaline and clonidine, but not phenylephrine, were more potent in the distal than the proximal part of the urethra. It is suggested that in the female rabbit urethra the lower EC50-value found for noradrenaline and clonidine in the distal as compared to the proximal part of the urethra, at least in part, is attributable to a higher number of postjunctional alpha 2-adrenoceptors in the distal than in the proximal urethra.

Adrenergic alpha-Agonists↗
PubMed2005

Vesicoureteral reflux: can the urethra be adequately assessed by using contrast-enhanced voiding US of the bladder?

PURPOSE: To prospectively evaluate contrast material-enhanced voiding ultrasonography (US) for assessment of the urethra by using voiding cystourethrography (VCUG) as the reference standard. MATERIALS AND METHODS: This study was approved by the ethics committee on human research. Written informed consent was obtained for all patients. A total of 146 pediatric patients suspected of having vesicoureteral reflux underwent US with a galactose-based contrast agent. The bladder was instilled with contrast agent and then filled with saline. US images of the urethra were videotaped before catheterization and during voiding. VCUG was subsequently performed in all patients. In female patients, the probe (a 3.5- or 5-MHz sector array or a 7.5-MHz linear transducer) was positioned longitudinally between the labia. In male patients, the transducer was placed longitudinally on the scrotum and then displaced distally toward the penile urethra. During voiding, attention was focused on the distention of the urethral walls and on the caliber of both the posterior and anterior urethra, which were measured with calipers. Sensitivity and specificity were estimated by using a confidence interval (CI) of 95%. RESULTS: All female patients and 75 male patients showed a normal urethra at both US and VCUG. Posterior urethral valves (PUV) were diagnosed in three patients at voiding US and were confirmed with findings from VCUG. Urethral stenosis was diagnosed in two male patients at voiding US and was confirmed with findings from VCUG. Seven male patients who had undergone surgery for PUV were adequately evaluated with both modalities. Sensitivity of voiding US was 100% (CI 95%: 96.5%, 100%); specificity was 100% (CI 95%: 69.9%, 100%). CONCLUSION: Voiding US is a reliable imaging modality for studying the urethra.

Adolescent↗
PubMed1979

Cultures from different parts of the urethra in female urethral syndrome.

It is a common belief that the female urethral syndrome is an infectious disease, caused by ascending vestibular microorganisms or bacteria harboured in the paraurethral glands. To study the flora of different parts of the urethra in patients with urgency, cultures were obtained in 36 cases from the proximal urethra, the external urethral opening, the distal urethra after paraurethral massage and from the upper vagina for comparison. All locations were dominated by lactobacillae. Enterobacteria and anaerobic bacteria occurred in approximately one third of the cases at all sites, although only in small amounts in the urethra, especially in the proximal part. The urethral and the vaginal flora resembled each other very closely. Only in a few cases did a possible pathogen reside solely in the urethra, i.e. it could not be found in the vagina or in the vestibular flora. On the whole, no appreciable amount of any microorganism was present in the urethra or in secretion from the paraurethral glands. The clinical significance which a very small amount of enterobacteria or anaerobes may have in these locations remains to be established.

Adult↗
PubMed1991

[Effect of moxisylyte on the lower urinary tracts (2). Effect on the urethra in anesthetized dogs].

Effect of moxisylyte on the lower urinary tracts was studied with the urethral pressure profile (UPP) and balloon method in anesthetized female dogs. In the UPP, moxisylyte produced relaxation in both the proximal and distal urethras. The relaxation effects of prazosin and bunazosin on the distal urethra was weaker than on the proximal urethra. In the balloon method, moxisylyte, prazosin, bunazosin and phentolamine caused a decrease in urethral pressure dose-dependently. The ID25 values of moxisylyte, prazosin, bunazosin and phentolamine were 23.4, 0.43, 0.76 and 33.1 micrograms/kg, respectively. In the balloon method, moxisylyte noncompetitively antagonized phenylephrine induced contraction of the urethra at high doses, whereas prazosin, bunazosin, phentolamine and yohimbine competitively antagonized phenylephrine induced contraction of the urethra. These results suggest that moxisylyte relaxes both the proximal and distal urethras due to alpha 1-adrenoceptor antagonistic and direct urethral smooth muscle relaxant actions. Therefore, moxisylyte is useful for the therapeutic treatment of micturitional disorder.

Adrenergic alpha-Antagonists↗
PubMed1999

Evidence for predominant mediation of alpha1-adrenoceptor in the tonus of entire urethra of women.

PURPOSE: We separated the entire length of the isolated human female urethra into seven parts from external urethral meatus to bladder neck and examined regional differences in contractile responses to noradrenaline, clonidine, acetylcholine and KCl. MATERIALS AND METHODS: The entire urethra was obtained from 9 female patients with a mean age of 72.2 +/- 1.8 years. The entire urethra (35 to 42 mm. in length) was transversely cut into seven parts, and the contractile responses to noradrenaline, clonidine, acetylcholine and KCl of these parts were examined. RESULTS: Noradrenaline but not clonidine produced concentration-dependent contraction in all parts, with a peak amplitude in middle to proximal urethra. In contrast, acetylcholine produced contraction only in proximal urethra and bladder neck. The amplitudes of noradrenaline-induced contraction were normalized against those induced by KCl, revealing similarity in patterns between noradrenaline-induced contractions and urethral pressure profile in human female urethra. These contractions to noradrenaline and acetylcholine were competitively inhibited by prazosin (pK(B): 8.38 +/- 0.10) and atropine (pK(B): 8.52 +/- 0.43), respectively. CONCLUSION: These findings suggest that sympathetic innervation helps maintain resting urethral tonus, mainly through alpha1-adrenoceptors.

Acetylcholine↗
PubMed2001

Morphological aspects of the female pig bladder neck and urethra: quantitative analysis using computer assisted 3-dimensional reconstructions.

PURPOSE: To investigate whether the pig is a suitable model for studies of lower urinary tract function and dysfunction, we sought to determine the morphology of the female pig bladder neck and urethra. Computer assisted 3-dimensional (D) reconstructions from step serial histological sections were used for visualization of the spatial relationships between neighboring urethral wall components, and the quantification of these components in the bladder neck and along the urethra. MATERIALS AND METHODS: Step serial histological paraffin sections from the bladder neck and urethra of 6 female pigs, stained with Masson's trichrome, were used to generate computer assisted 3-D reconstructions using MacStereology (Ranfurly MicroSystems Ltd., Airdrie, United Kingdom) as the 3-D software package. RESULTS: The bladder neck and urethral anatomy revealed well defined smooth and striated muscle layers that varied in location, regional distribution and orientation. Circular smooth muscle was maximally developed in the mid urethra, at which point maximal urethral pressure was observed. The longitudinal smooth muscle layer appeared continuous with the detrusor, implicating a possible role in urethral shortening at the onset of voiding. A small circular and longitudinal striated muscle component was present in the distal urethra. CONCLUSIONS: Anatomical differences exist between the female pig and human bladder neck and urethra, which were successfully highlighted using computer assisted 3-D reconstructions from step serial histological paraffin sections.

Animals↗
PubMed2001

Construction of female urethra using buccal mucosa graft.

PURPOSE: We reviewed our experience with buccal mucosa grafts for reconstructing difficult female urethral problems. METHODS AND METHODS: Since 1994, we have used a buccal mucosa graft to reconstruct the urethra in 7 girls 3 to 13 years old. The underlying pathological condition was a fibrotic urethra after previous operations for cloacal exstrophy, cloacal malformation, iatrogenic urethral stricture, and multiple false passages in a previously reconstructed urethra of vaginal mucosa that made clean intermittent catheterization difficult. A full-thickness buccal mucosa graft was tubularized in situ as the neourethra to the base of the clitoris. In patients with cloacal exstrophy and cloacal malformation the bladder neck and urethra were widely exposed transabdominally by splitting the pubic symphysis. The fibrotic mucosa was excised and the tubularized buccal mucosa graft was wrapped with periurethral tissues. Other patients underwent transvaginal surgery in the prone position and the graft was covered with a buttock flap. RESULTS: Patients were followed for 12 to 58 months (mean 34.7). Those with cloacal exstrophy and cloacal malformation had been completely incontinent before urethral reconstruction but all attained complete continence postoperatively. They and the girl who underwent urethral reconstruction for difficult catheterization performed clean intermittent catheterization easily. The patient with urethral stricture voided via the urethra without difficulty. CONCLUSIONS: In select female patients with difficult urethral reconstructive problems a tubularized free graft obtained from the buccal mucosa may be effectively used when local tissue is fibrotic and unsuitable for creating a supple new urethra.

Adolescent↗
PubMedDate not supplied

[Ultrasound and X-ray urethrography and urethroscopy during endoscopic operations on the urethra].

In 41 patients are made x-ray ascending and descending and transrectal US (TRUS) of an urethrography and endoscopy before and after transurethral (TUR) of operations on a urethra. For 35 patients there were posttraumatic strictures and obliterations of a urethra, for 3--postinflammatory strictures, for 2--iatrogenic false courses of a urethra and for 1--congenital diverticulum of a urethra. The comparative estimation ultrasonic and x-ray urethrography and urethroscopy has shown, that they are not competitive, but complementary techniques. Thus TRUS of a urethra, as the technique irrelevant with radial load on the patient, can and should more widely be used born for primary diagnostic, and for monitoring outcomes TUR on a urethra.

Contrast Media↗
PubMed1992

[Anatomy of the posterior urethra].

The short section of the urethra that passes through the urogenital diaphragm is termed the membranous urethra. It is accompanied by several vessels and nerve fibers. In surgery on the membranous urethra the perineal body is of crucial importance, and precise knowledge of the course of the urethra through the pelvic floor is essential. Furthermore, the relationship between the membranous urethra and its accompanying structures is of great importance. These include the branches of the internal pudendal artery, the prostatic venous plexus and the cavernous nerves coursing ventrally from the pelvic plexus. The nerves supplying the membranous urethra were studied in fetuses with the help of a magnifying lens. The results of the dissections are documented by histological sections, photographs and paintings.

Aged↗
PubMed2004

[Experimental study on preventing postoperative posterior urethra scar in response to Tablet Fu Kang].

OBJECTIVE: To find an effective measurement to prevent and decrease the posterior urethral scar stricture. METHODS: Twenty New Zealand rabbits were chosen. All the rabbits were made posterior urethra disruption model, and at the same time, the urethra anastomosis operation was performed. Twenty rabbits were divided into two groups after operation at random. One group was treated by Tablet Fu Kang (experimental group), another group was treated by NS (control group). All the rabbits were killed three weeks later, the urethra anastomotic stoma tissue was chosen and stained with Masson. All the figures of slides were inputted into figure analytic system. RESULTS: There were little collagenous fiber, sparsely and arranged in good order in scar tissue of urethra anastomotic stoma in experimental group. The area of collagenous fibers was 117.11 +/- 10.17 microm2 in three visual fields. There were many collagenous fibers, densely,and arranged in disorder in scar tissue of urethra anastomotic stoma in control group, the relative area was 136.43 +/- 15.85 microm2. There was statistic significance when comparing the area of collagenous fiber in two groups (P < 0.05). CONCLUSIONS: Tablet Fu Kang could restrain the hyperplasia of fibroblast in the process of wound healing of rabbit smooth muscle in urethra.

Anastomosis, Surgical↗
PubMed1979

The adult male urethra: normal anatomy, pathology, and method of urethrography.

Detailed knowledge of the normal anatomy of the urethra and adjacent structures is essential to an understanding of the normal radiologic landmarks on urethrography, and is prerequisite to the radiologic interpretation of the diseased urethra. The nature of fibrosis in the urethra must also be clearly understood, since radiologic interpretation of urethral scarring influences surgical management. No longer is it sufficient for the radiologist to delineate a tight structure in the urethra and leave the operative decision solely to clinical assessment. Dynamic retrograde urethrography allows the radiologist to direct the attention of the urologist to the membranous urethra and to the possibility that transsphincter urethroplasty may be required. While voiding urethrography is an integral part of the examination and may provide additional information, voiding urethrography without dynamic retrograde urethrography without dynamic retrograde urethrography may be misleading in that soft scarring of the urethra may be missed.

Adult↗
PubMed1993

[Incidence of the form and caliber of urethral resistance. Evaluation for a normal masculine urethra and in cases of obstruction due to prostatic hypertrophy].

Certain forms of benign prostatic hypertrophy are associated with a reduction of the calibre of the prostatic urethra of the median lobe, a defect of infundibulisation of the bladder neck and a dilated appearance of the bulbar urethra. The objective of this study was to verify whether hydrodynamic arguments could be used to confirm the concept that defective infundibulisation of the bladder neck is directly responsible for an obstructive syndrome or via a reduction in the calibre of the bladder neck orifice. More generally, this study was designed to quantify the distribution of resistance to flow along the normal urethra and to define the role of cervicoprostatic and urethral deformities in the obstruction associated with benign prostatic hypertrophy. Urodynamic studies are unable to answer this question, as the instantaneous urethral resistance is evaluated globally by the Pressure-Flow relation. The authors performed morphological analysis to divide the urethra into simple hydraulic segments for which the corresponding pressure drop coefficients were calculated. These coefficients constitute an approach to segmental resistance to flow and can be used to quantify changes in shape observed on voiding urethrography or ultrasonography. Digital analysis of voiding urethrographies showed that, under normal conditions, urethral resistance was regularly distributed along the urethra and essentially depended on friction of the urethral wall. In the case of benign prostatic hypertrophy, even with a median lobe, the increase in the pressure drop coefficients was due to a reduction in the calibre of the bladder neck orifice and prostatic urethra. Cervical deformities appeared to be minimally obstructive, according to urodynamic parameters, if they were not associated with a reduction in the calibre of the bladder neck orifice.

Evaluation Studies as Topic↗