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.     

Mathematical model of the male urinary tract

The paper presents a simplified (but not trivial) mathematical model of the interaction between the urine flow and the male urethra and bladder, respectively. Urine is assumed to be a Newtonian fluid. The flow is considered to be non-stationary, isothermal and turbulent. The urethra and bladder wall, featuring elastic properties, experience large displacements and strains. The dynamic forces are included in the urethra wall motion. When fully extended the urethra attains the shape of an axisymetric tube. An iterative method based on the uncoupled approach is developed.     

Age-dependent changes in particulate and soluble guanylyl cyclase activities in urinary tract smooth muscle

Regional and age specific differences are observed in the sodium nitroprusside induced relaxation responses in the urinary tract. To clarify these differences, guanylyl cyclase activity is assayed in particulate and soluble fractions from the ureter, bladder dome, and urethra of young (11-18 days), adult (90-100 days), and old adult (2-3 years) guinea pigs. The rank order of soluble guanylyl cyclase activities is urethra = ureter > bladder dome with the largest decreases with aging occurring in the bladder. Atrial natriuretic factor (10-7 M) increases particulate guanylyl cyclase activity in the three tissues at all ages tested, with the activity being highest in the ureter. ATP (0.5 mM) activates particulate guanylyl cyclase in the ureter, bladder and urethra of old adult guinea pigs, and enhances atrial natriuretic factor induced activation of particulate guanylyl cyclase in all tissues and at all ages tested. The higher levels of soluble guanylyl cyclase activity in the urethra and ureter compared to the bladder parallel sodium nitroprusside induced relaxation in these tissues.     

Alpha- and beta-adrenergic and muscarinic cholinergic binding sites in the bladder and urethra of the rabbit

The affinities of a number of alpha- and beta-adrenergic binding sites and muscarinic cholinergic binding sites in rabbit urethra and bladder have been determined, using specific radioligand receptor binding assays. There was a greater density of beta-binding sites than alpha-binding sites in the bladder, while, in the urethra, there was a greater density of alpha-binding sites than beta-binding sites. The number of alpha-binding sites was fourfold greater in the urethra, whereas there were fewer beta-binding sites in the urethra. There were fewer muscarinic binding sites in the urethra than in the bladder. The dissociation constant for [3H]dihydroalprenolol at the beta-binding site was 6.4 nM, for [3H]dihydroergocryptine at the alpha-binding site was 2.11 nM, and for 3H-labelled l-quinuclidinyl benzilate at the muscarinic binding site was 0.22 nM.     

Expression of the androgen receptor and 5α-reductase type 2 in the developing human fetal penis and urethra

Normal penile development is dependent on testosterone, its conversion via steroid 5 alpha-reductase type 2 to dihydrotestosterone, and a functional androgen receptor (AR). The goal of this study was to investigate the distribution of AR and 5 alpha-reductase type 2 in the developing human fetal external genitalia with special emphasis on urethra formation. Twenty fetal genital specimens from normal human males (12-20 weeks gestation) were sectioned serially and stained by avidin-biotinylated peroxidase complex method with antigen retrieval. Stained sections throughout male genital development documented the expression of AR and 5 alpha-reductase type 2 in the phallus. Between 12 and 14 weeks of gestation, AR was localized to epithelial cells of the urethral plate in the glans, the tubular urethra of the penile shaft, and stromal tissue surrounding the urethral epithelium. In the fetal penis between 16 and 20 weeks gestation, the density of AR expression was greatest in urethral epithelial cells versus the surrounding stromal tissues. There was a characteristic pattern of AR expression in the glandular urethral epithelium between 16 and 20 weeks gestation. AR expression was greater along the ventral aspect of the glandular urethra than along the dorsal aspect of the urethral epithelium. The expression of 5 alpha-reductase type 2 was localized to the stroma surrounding the urethra, especially along the urethral seam area in the ventral portion of the remodeling urethra. These anatomical studies support the hypothesis that androgens are essential for the formation of the ventral portion of the urethra and that abnormalities in either the AR or 5 alpha-reductase type 2 can explain the occurrence of hypospadias.     

Normal development of the male anterior urethra

A histological study was performed on serially sectioned human and mouse embryos to study the influences of programmed cell death (PCD) during morphogenesis for clarifying the existing controversies on the morphology and basic processes involved in the embryonic development of the male anterior urethra. The following new insights into the development of the anterior urethra could be established. The formation of the urethra starts with the early adhesion of the arms of the genital tubercle. In this way an epithelial plate is formed, located in the ventral midline, that is in continuity with the cloacal membrane. Male sex differentiation takes place following rupture of this cloacal membrane through programmed cell death. Fusion of the urogenital swellings with primary luminization gives rise to the penile urethra, whereas the glandular part of the urethra is formed through secondary luminization of the epithelial cord that is formed during fusion of the arms of the genital tubercle, i.e., the glans. In both fusion processes, apoptosis plays a key role. The consequence of fusion of the urogenital swellings is that their mesodermal cores unite on the ventral aspect of the penile urethra, where they differentiate into the integumental structures. The prepuce starts to develop as a fold of ectoderm with a mesodermal core after complete fusion of the entire urethra. Finally, the scrotum was found to develop through merging of the labioscrotal swellings and not by fusion.     

Prostaglandin D2 effects and DP1/DP2 receptor distribution in guinea pig urinary bladder out‐flow region

The proximal urethra and urinary bladder trigone play important roles in continence. We have previously shown that PGD₂ is released from guinea pig bladder urothelium/suburothelium and can inhibit detrusor contractile responses. We presently wished to investigate PGD₂ actions in guinea pig out‐flow region and the distribution of DP₁/DP₂ receptors. The effects of PGD₂ on urothelium‐intact trigone and proximal urethra contractility were studied in organ bath experiments. Expression of DP₁/DP₂ receptor proteins was analysed by western blot. Immunohistochemistry was used to identify distribution of DP₁/DP₂ receptors. PGD₂ in a dose‐dependent manner inhibited trigone contractions induced by electrical field stimulation (EFS) and inhibited spontaneous contractions of the proximal urethra. PGD₂ was equally (trigone) or slightly less potent (urethra) compared with PGE₂. Expression of DP₁ and DP₂ receptors was found in male guinea pig bladder trigone, neck and proximal urethra. In the trigone and proximal urethra, DP₁ receptors were found on the membrane of smooth muscle cells and weak immunoreactivty was observed in the urothelium. DP₂ receptors were distributed more widespread, weakly and evenly in the urothelium and smooth muscles. Inhibitory effects by PGD₂ on motor activity of guinea pig trigone and proximal urethra are consistent with finding DP₁ and DP₂ receptors located in the urothelium and smooth muscle cells of the trigone and proximal urethra, and PGD₂ may therefore be a modulator of the bladder out‐flow region, possibly having a function in regulation of micturition and a role in overactive bladder syndrome.     

A new method to correlate histology with biomechanical properties in urethral tissue. An in-vitro study using light microscopy and scanning acoustic microscopy

When surveying the classical biomechanical theory of flow and resistance, the passive elastic properties of the urethra seems to be important for the transport of urine though the urethra. The aim of this study was to show that scanning acoustic microscopy (SAM) is a suitable methodology for investigating elastic properties of the urethra, and that it can be used to correlate elastic properties to histological areas. One 40 kg female pig and one 2 kg male rabbit comprised the material. A SAM2000 was used at a working frequency of 1000 MHz. Sections of nominal 3 micrometer thickness fixed urethral tissue were prepared for SAM and stained for light microscopy. The histological layers of the urethra were evident in the SAM image, and showed highly variable values of elastic properties. The layers seen with SAM correlated well with those seen with light microscopy. In conclusion, we have provided the first images of the microelastic properties of the urethra and correlated them to histology.     

Tissue-specific requirements of beta-catenin in external genitalia development

External genitalia are body appendages specialized for internal fertilization. Their development can be divided into two phases, an early androgen-independent phase and a late androgen-dependent sexual differentiation phase. In the early phase, the embryonic anlage of external genitalia, the genital tubercle (GT), is morphologically identical in both sexes. Although congenital external genitalia malformations represent the second most common birth defect in humans, the genetic pathways governing early external genitalia development and urethra formation are poorly understood. Proper development of the GT requires coordinated outgrowth of the mesodermally derived mesenchyme and extension of the endodermal urethra within an ectodermal epithelial capsule. Here, we demonstrate that beta-catenin plays indispensable and distinct roles in each of the aforementioned three tissue layers in early androgen-independent GT development. WNT-beta-catenin signaling is required in the endodermal urethra to activate and maintain Fgf8 expression and direct GT outgrowth, as well as to maintain homeostasis of the urethra. Moreover, beta-catenin is required in the mesenchyme to promote cell proliferation. By contrast, beta-catenin is required in the ectoderm to maintain tissue integrity, possibly through cell-cell adhesion during GT outgrowth. The fact that both endodermal and ectodermal beta-catenin knockout animals develop severe hypospadias in both sexes raises the possibility that the deregulation of any of these functions can contribute to the etiology of congenital external genital defects in humans.     

Spinning top urethra and lower urinary tract dysfunction in a young female

Spinning top urethra (STU) denotes a particular urethral configuration that is a dilated posterior urethra mainly seen in young girls or women. STU deformity arises secondary to detrusor instability, leading to a rise the intravesical pressure against a closed sphincter. We describe a case of spinning top urethra in a 30-year-old woman who presented with lower urinary tract symptoms and left flank pain.     

Different epithelia in the distal human male urethra

Summary The distal segment of the human male urethra, in particular the fossa navicularis, was studied with light- and electron microscopy as well as by means of histochemical and immunocytochemical methods. The fossa navicularis of the urethra contains a circumscribed zone of extremely thick, non-keratinized stratified squamous epithelium composed of cells containing a large amount of glycogen. These cells lack acid phosphatase activity and lysozyme-like immunoreactivity, both of which can be demonstrated to varying extents in the other zones of the distal male urethra. These glycogen-rich cells are considered to be the substrate for an endogenous flora of lactobacteria, whereas the acid-phosphatase activity and the lysozyme-like immunoreactivity indicate the presence of macrophages and the secretion of bactericidal agents at the epithelial surface. These observations suggest that the different zones with heterogeneous properties in the distal male urethra probably represent a defense system against the invasion of pathogenic microorganisms. Moreover, the glycogen-rich zone, which resembles the glycogen-rich epithelium of the vagina, is estrogen-dependent. This is demonstrated in cases of sex reversal in which after long-lasting estrogen treatment the glycogen-rich zone becomes extremely extended by displacement of the neighbouring epithelium.     

Reparation en urgence differee des ruptures traumatiques de l’urethre posterieur

The management of posterior urethra injuries is still subject of controversies. Some authors recommend primary or deferated emergency repair operation, while some others wait for about three months and repair the urethral stenosis. The analysis of a series of fifteen cases shows that when patients are treated by deferated emergency operation, the results are usually good. However, when repair is performed later, results are less good, and the rate of sexual impotency is higher in this group. We conclude that deferated emergency repair operation is the best way to manage disrupted posterior urethra.     

A method of obtaining material for the bacteriological diagnosis of urethral diseases

An installation is developed for sampling the contents of urethra (A. c. USSR 980726). The installation promotes acceleration of the correct diagnosis under the torpid and chronic inflammatory processes in the urethra. The above installation permits obtaining data on distribution of the microbic flora at a different depth of mucosa of the anterior area of the male urethra. In this case the mixing of samples taken for investigation from different sites is impossible.     

Characteristics of changes in microbiocenosis in patients with chronic nonspecific urethritis

The species composition and the complex of biological characteristics of microflora in the front section of urethra in healthy males and in patients with chronic nonspecific urethritis. The study revealed that in patients with chronic nonspecific nongonococcal urethritis changes in the microbiocenosis of the urethra were observed. These changes were manifested by a decrease in the number of species, the appearance of Grain-negative enterobacterial flora and an increase in the persistence potential of symbiotic bacteria. These disturbances are regarded as the manifestation of urogenital dysbiosis.     

Diphallia in a mixed-breed dog with multiple anomalies

Complete diphallia was detected in a six-month-old Poodle cross dog. Duplication of the urinary bladder, right renal hypoplasia, bifurcation of the descending colon and bilateral cryptorchidism were also present. The left urethra was patent, and emptied the left urinary bladder; the right urethra ended blindly at a point 2.5 cm from the tip of the right penis. The left urinary bladder was joined medially to a right urinary bladder with no interbladder communication; however, the right bladder opened caudally into a blind sac which drained into the left prostatic urethra. Pyelonephritis of the left kidney was present, and was suspected to be due to ascending bacterial infection of the right urinary bladder and the right segment of the bifurcated descending colon, which terminated at the apex of the right urinary bladder. Diphallia and associated urogenital anomalies are reviewed.     

Carcinome urothélial de l’urètre: une nouvelle observation et revue de la littérature

Urothelial carcinoma of the male urethra is a rare tumour. We report a new case of urothelial carcinoma of the urethra in a 64-year old man who was examined due to a dysuria. Retrograde and voiding urethrocystography carried out had shown images of bulbopenile urethral stricture treated by urethroplasty. Histological examination of the urethrectomy part revealed a urothelial carcinoma of the urethra. The patient refused any additional treatment and survived 14 months after diagnosis.     

Sex-Related Differences in Urethra Development in Human Embryos

Virtually no information on the chronology of prenatal development of the human urinary tract and the sex-related differences in the emergence of urinary tract topography during embryonic development is presently available. The aim of our work was to study sex-related differences in urethra development in human embryos and early fetuses. Forty-nine preparations of human embryos and early fetuses without external signs of anatomical abnormalities were studied in order to achieve the aim and fulfill the objectives of the study. Embryos and early fetuses were divided into six groups according to gestational age and parietococcygeal length. The complex of adequate methods of morphological research used in the study included preparation and microscopy of serial histological and anatomical sections of human embryos, including female and male urinary tracts, preparation of 3D-reconstruction models, and morphometry. The formation of prostatic urethra, a derivative of the urogenital sinus, was shown to occur at the beginning of the ninth week of embryogenesis, and the primordium of the internal sphincter of the urinary tract was formed at the end of the tenth week. Formation of the terminal part of spongy urethra took place during weeks 10–11 and involved funnel-like protrusion of the ectoderm from the top of the balanus towards the urethra lumen. The secondary ventral displacement of the urethral opening does not occur in female fetuses, and, therefore, only the prostatic urethra is a homolog of the female urinary tract. The pelvic part of the urogenital sinus was transformed into the prostatic urethra and the membranous urethra of the male at the end of the first stage of fetal development. Elongation of the genital tubercle (a penis primordium) and formation of the urethral ridge walls that involved the urogenital folds occurred at the same time.     

Muscular tubes of urethra engineered from adipose-derived stem cells and polyglycolic acid mesh in a bioreactor

We have explored the feasibility of using adipose-derived stem cells (ADSCs) and polyglycolic acid (PGA) for constructing muscular tubes of urethra in a bioreactor. With the induction of by 5-azacytidine, ADSCs were found to acquire a myoblast phenotype. Here we seeded ADSCs in a PGA mesh to construct the cell–PGA complex that was cultured statically for 1 week. Afterwards, the cell–PGA complex was subjected to extension stimulation in a bioreactor for 5 weeks. A muscular tube of urethra was formed after 6 weeks. Histological examination showed differentiated ADSCs and collagenous fibers had orientated well. This study demonstrates that tissue engineering of urethra tissues in vitro by using a bioreactor leads to tissue maturation and the differentiation of ADSCs. This novel technique could provide an effective approach for urethra tissue engineering.     

尿道下裂患者术前术后尿道细菌的研究

目的了解尿道下裂患者尿道修复前后尿道及其周围细菌的分布,为临床预防尿道下裂术后感染提供依据。方法采集30例尿道下裂患者术前尿道、会阴部,术后重建尿道、会阴部皮肤作细菌分离、培养、鉴定、统计分析、药敏试验。结果术前术后尿道与会阴部细菌分布差异无显著性（P〉0．05）,有革兰阳性菌表皮葡萄球菌、肠球菌等,革兰阴性菌变形杆菌、阴沟肠杆菌、大肠埃希菌等,以表皮葡萄球菌占多数。结论术后重建尿道内存在的细菌由会阴部皮肤表面细菌转移而入。菌株以革兰阳性菌表皮葡萄球菌占多数,菌株耐药率较高,临床选择药物要慎重。     

Advances in the understanding of sress urinary incontinence and the promise of stem-cell therapy

The middle urethra and external urethral sphincter are the focus in management of stress urinary incontinence, and recent cellular-therapy research suggests a new paradigm in treatment. Cell-based therapies are most often described as using autologous multipotent stem cells procured from bone marrow in procedures that may be painful, require anesthesia, and yield low numbers of mesenchymal stem cells upon processing. In contrast, muscleand adipose-derived stem cells can be obtained easily in large quantities under local anesthesia. Instead of lifting the urethra with a sling or bulking up the urethral sphincter with collagen, we now have the potential to restore function with the use of autologous stem cells.