The development of the human vaginal fornix and the portio cervicis.

INTRODUCTION: One of the transitional zones of the human body is situated in the cervix uteri. The developmental differentiation of epithelial and stromal characteristics in such a region is of high clinical interest. However, few studies have focused on the development of this region, and information in anatomical and clinical textbooks is limited. We therefore examined the development of the human vaginal fornix and the cervix uteri during prenatal development. MATERIALS AND METHODS: We examined 29 female embryos and fetuses between 20 and 34 weeks and two newborns using histology and immunohistochemistry. RESULTS: The characteristic shape of the portiocervicis and the vaginal fornix first became visible in mid-term fetuses because of the different muscular coats and of an uncategorized Müllerian-derived epithelium, which was rapidly replaced by a multilayered squamous epithelium. Only thereafter, in older fetuses, were there organogenetic differentiation of the epithelia and the underlying stroma of the cervical canal. UGS-derived p63/CK17-positive cells could be identified as precursor cells for the squamous epithelium, and Müllerian-derived CK7-positive cells for the columnar-type epithelium. Both cell types and different stromal zones were already present in a prenatal transformation zone. Initial functional differentiation could be observed in perinatal stages. CONCLUSIONS: Our results on prenatal human development strongly support the view that two different cell lineages meet at the transitional zone of the cervix uteri and that these lineages depend on alternative signals from the underlying stromal compartment.

Early appearance of key transcription factors influence the spatiotemporal development of the human inner ear.

Expression patterns of transcription factors leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5), transforming growth factor-ß-activated kinase-1 (TAK1), SRY (sex-determining region Y)-box 2 (SOX2), and GATA binding protein 3 (GATA3) in the developing human fetal inner ear were studied between the gestation weeks 9 and 12. Further development of cochlear apex between gestational weeks 11 and 16 (GW11 and GW16) was examined using transmission electron microscopy. LGR5 was evident in the apical poles of the sensory epithelium of the cochlear duct and the vestibular end organs at GW11. Immunostaining was limited to hair cells of the organ of Corti by GW12. TAK1 was immune positive in inner hair cells of the organ of Corti by GW12 and colocalized with p75 neurotrophic receptor expression. Expression for SOX2 was confined primarily to the supporting cells of utricle at the earliest stage examined at GW9. Intense expression for GATA3 was presented in the cochlear sensory epithelium and spiral ganglia at GW9. Expression of GATA3 was present along the midline of both the utricle and saccule in the zone corresponding to the striolar reversal zone where the hair cell phenotype switches from type I to type II. The spatiotemporal gradient of the development of the organ of Corti was also evident with the apex of the cochlea forming by GW16. It seems that highly specific staining patterns of several transcriptions factors are critical in guiding the genesis of the inner ear over development. Our findings suggest that the spatiotemporal gradient in cochlear development extends at least until gestational week 16.

Growth and cellular patterning during fetal human inner ear development studied by a correlative imaging approach.

BACKGROUND: Progressive transformation of the otic placode into the functional inner ear during gestational development in humans leads to the acquisition of hearing perception via the cochlea and balance and spatial orientation via the vestibular organ. RESULTS: Using a correlative approach involving micro-computerized tomography (micro-CT), transmission electron microscopy and histological techniques we were able to examine both the morphological and cellular changes associated with human inner ear development. Such an evaluation allowed for the examination of 3D geometry with high spatial and temporal resolution. In concert with gestational progression and growth of the cochlear duct, an increase in the distance between some of the Crista ampullaris is evident in all the specimens examined from GW12 to GW36. A parallel increase in the distances between the macular organs - fetal utricle and saccule - is also evident across the gestational stages examined. The distances between both the utricle and saccule to the three cristae ampullares also increased across the stages examined. A gradient in hair cell differentiation is apparent from apex to base of the fetal cochlea even at GW14. CONCLUSION: We present structural information on human inner ear development across multiple levels of biological organization, including gross-morphology of the inner ear, cellular and subcellular details of hearing and vestibular organs, as well as ultrastructural details in the developing sensory epithelia. This enabled the gathering of detailed information regarding morphometric changes as well in realizing the complex developmental patterns of the human inner ear. We were able to quantify the volumetric and linear aspects of selected gestational inner ear specimens enabling a better understanding of the cellular changes across the fetal gestational timeline. Moreover, these data could serve as a reference for better understanding disorders that arise during inner ear development.

Langerhans cells in hypospadias: an analysis of Langerin (CD207) and HLA-DR on epidermal sheets and full thickness skin sections.

BACKGROUND: Hypospadias are among the most common genital malformations. Langerhans Cells (LCs) play a pivotal role in HIV and HPV infection. The migration of LC precursors to skin coincides with the embryonic period of hypospadias development and genetic alterations leading to the formation of hypospadias impact the development of ectodermally derived tissues. We hypothesized that this might be associated with a difference in frequency or morphology of epidermal and dermal LCs in hypospadias patients. METHODS: A total of 43 patients from two centers were prospectively included into this study after parental consent and ethics approval. Epidermal and dermal sheets were prepared from skin samples of 26 patients with hypospadias, 13 patients without penile malformations and 4 patients with penile malformations other than hypospadias. Immunofluorescence staining of sheets was performed with anti-HLA-DR-FITC and anti-CD207/Langerin-A594 antibodies. Skin sections from 11 patients without penile malformation and 11 patients with hypospadias were stained for Langerin. Frequencies as well as morphology and distribution of epidermal and dermal LCs on sheets and sections were microscopically evaluated. Cell counts were compared by unpaired t-tests. RESULTS: There was no difference in frequency of epidermal LCs, Neither on sheets (873 ± 61 vs. 940 ± 84LCs/mm2, p = 0.522) nor on sections (32 ± 3 vs. 30 ± 2LCs/mm2, p = 0.697). Likewise, the frequency of dermal LCs (5,9 ± 0,9 vs. 7.5 ± 1.3LCs/mm2, p = 0.329) was comparable between patients with hypospadias and without penile malformation. No differences became apparent in subgroup analyses, comparing distal to proximal hypospadias (p = 0.949), younger and older boys (p = 0.818) or considering topical dihydrotestosterone treatment prior to surgery (p = 0.08). The morphology of the LCs was not different comparing hypospadias patients with boys without penile malformations. CONCLUSIONS: LCs are present in similar frequencies and with a comparable morphology and distribution in patients with hypospadias as compared to children without penile malformations. This suggests that patients with hypospadias are not different from patients with normal penile development considering this particular compartment of their skin immunity.

Do ultrasound findings of levator ani "avulsion" correlate with anatomical findings: A multicenter cadaveric study.

AIMS: This study aimed to validate the levator "avulsion" injury as seen on ultrasound against anatomical dissection in the same cadaver. METHODS: Puboviseral muscle (PVM) anatomy of female cadavers was studied using 3D-translabial ultrasonography and an "avulsion" confirmed per standard recommendations [Dietz HP. Aust N Z J Obstet Gynaecol 53:220-230, 2013]. Cadavers were then dissected to determine the macroscopic attachment or detachment of the PVM and the dimensions including the PVM symphysis gap and PVM attachment depth. Intra and inter-observer reliability of USS findings and anatomical measurements were assessed using the Cohen's κ and Bland & Altman plots respectively. McNemar's and Mann-Whitney U tests were used to compare imaging and cadaveric dissection findings. RESULTS: "Avulsions" were seen on imaging in 11/30 (36.7%) cadavers; the defect was bilateral in 1/30 (3.3%) and unilateral in 10/30 (33.3%). No "avulsion" was found at dissection (McNemar's χ(2) = 60.0, P < 0.001). An additional thirty-nine cadavers were dissected with no "avulsion" identified. A narrower PVM insertion depth was strongly associated with "avulsion" on ultrasound (mean: 4.79 mm vs. 6.32 mm, Z = -3.191, P = 0.001). Intra- and inter-observer agreement was perfect (K = 1.0 ± 0.0) and good (K = 0.85 ± 0.142) for anatomical "avulsions" and USS, respectively. CONCLUSIONS: There is a clear difference between anatomical and USS findings. The imaged appearance of an "avulsion" does not represent a true anatomical "avulsion" as confirmed on dissection. The term "avulsion" is misrepresentative and should not be used to describe this imaging finding. Moreover, further attempts at surgically repairing this defect should be avoided, at least until there is a better understanding of its pathophysiology. Neurourol. Urodynam 35:683-688, 2016. © 2015 Wiley Periodicals, Inc.

Biomechanical testing of circumferential instrumentation after cervical multilevel corpectomy.

STUDY DESIGN: Biomechanical investigation. PURPOSE: This study describes ex vivo evaluation of the range of motion (ROM) to characterize the stability and need for additional dorsal fixation after cervical single-level, two-level or multilevel corpectomy (CE) to elucidate biomechanical differences between anterior-only and supplemental dorsal instrumentation. METHODS: Twelve human cervical cadaveric spines were loaded in a spine tester with pure moments of 1.5 Nm in lateral bending (LB), flexion/extension (FE), and axial rotation (AR), followed by two cyclic loading periods for three-level corpectomies. After each cyclic loading session, flexibility tests were performed for anterior-only instrumentation (group_1, six specimens) and circumferential instrumentation (group_2, six specimens). RESULTS: The flexibility tests for all circumferential instrumentations showed a significant decrease in ROM in comparison with the intact state and anterior-only instrumentations. In comparison with the intact state, supplemental dorsal instrumentation after three-level CE reduced the ROM to 12% (±10%), 9% (±12%), and 22% (±18%) in LB, FE, and AR, respectively. The anterior-only construct outperformed the intact state only in FE, with a significant ROM reduction to 57% (±35 %), 60% (±27%), and 62% (±35%) for one-, two- and three-level CE, respectively. CONCLUSIONS: The supplemental dorsal instrumentation provided significantly more stability than the anterior-only instrumentation regardless of the number of levels resected and the direction of motion. After cyclic loading, the absolute differences in stability between the two instrumentations remained significant while both instrumentations showed a comparable increase of ROM after cyclic loading. The large difference in the absolute ROM of anterior-only compared to circumferential instrumentations supports a dorsal support in case of three-level approaches.

The developmental origin of cervical and vaginal epithelium and their clinical consequences: a systematic review.

OBJECTIVE: Studies on the development of the embryological and fetal development of the cervix and the vagina are rare and mostly go back to the first decades of the last century. The aims of this review were to present the latest knowledge concerning the developmental origin of cervical and vaginal epithelium and to point out new results in the context of different clinical findings. MATERIALS AND METHODS: Relevant studies published between 1910 and 2013 were identified via PubMed, MEDLINE, OVID, Web of Science, and EMBASE. The reference lists of retrieved articles were reviewed to locate additional articles. Each abstract was reviewed, and the appropriate publications were obtained and reviewed as well. A total of 33 articles and 8 book chapters were selected for citation in this review. RESULTS: New objective findings clearly show that human prenatal epithelialization of the cervix and vagina results in 3 morphogenetically determined units: (i) the Müllerian columnar epithelium of the endocervix, (ii) the Müllerian squamous epithelium of the ectocervix and the upper vagina, and (iii) the vaginal squamous epithelium of the lower vagina. CONCLUSIONS: These results are of high clinical relevance and may provide new insight into the histogenesis of ectopy, vaginal adenosis, and the congenital transformation zone. They should be added to the explanations in gynecological, colposcopical, and gynecopathological textbooks.

Anatomical mapping of the nasal muscles and application to cosmetic surgery.

We present an anatomical mapping of the most important muscles influencing the nose, incorporating constant anatomical structures, and their spatial correlations. At our disposal were the midfaces of 18 bodies of both sexes, obtained by informed consent from body donors aged between 60 and 80 years. Macroscopically, we dissected the nasal regions of eight corpses, six midfaces were prepared according to plastination histology, four by creating plastinated slices. On their way from their periosteal origin to the edge of the skin, the muscles of the nose cross the subcutaneous adipose tissue, dividing it into superficial and deep layers. The individual muscle fibers insert into the skin directly at the reticular corium. Sometimes, they reach the border of the epidermis which represents a special arrangement of corial muscle attachments. The course of the anatomical fibers of individual nasal muscles presented macroscopically and microscopically in this study offers surgeons a detailed overview of the anatomically important muscular landmarks of the midface.

Spatio-temporal expression of HOX genes in human hindgut development.

BACKGROUND: Hox genes belong to a highly conserved subgroup of the homeobox gene superfamily. Studies of animal models have emphasized their role in defining the body plan by their coordinated expression along the body axis during ontogeny. Although an important role of HOX genes in human development is assumed, little is known about their expression during human ontogenesis. Therefore, we investigated the expression of the nine most posterior members of the HOXA, HOXB, HOXC, and HOXD clusters in embryonic hindgut between weeks 6 to 12 and in adult rectal tissue. RESULTS: Applying in situ hybridization and immunohistochemistry, we observed expression of HOXA11, HOXA13, HOXD12, and HOXD13 in developmental week 6. However, expression of HOXD12 faded during weeks 7 and 8, and then became increasingly re-expressed during week 9 in humans. With the exception of HOXD13, all expressed HOX genes dropped below detection limits in week 11. Adult rectal tissue displayed distinct HOXA11, HOXA13, HOXD12, and HOXD13 expression patterns within the rectal layers. CONCLUSIONS: Our data suggest a strict spatio-temporal regulation of HOX gene expression during human development, supporting the idea of their role as key regulators. Nonetheless, the expression pattern of distinct HOX genes differs markedly from animal models.

Spatial transcriptomics in embryonic mouse diaphragm muscle reveals regional gradients and subdomains of developmental gene expression.

The murine embryonic diaphragm is a primary model for studying myogenesis and neuro-muscular synaptogenesis, both representing processes regulated by spatially organized genetic programs of myonuclei located in distinct myodomains. However, a spatial gene expression pattern of embryonic mouse diaphragm has not been reported. Here, we provide spatially resolved gene expression data for horizontally sectioned embryonic mouse diaphragms at embryonic days E14.5 and E18.5. These data reveal gene signatures for specific muscle regions with distinct maturity and fiber type composition, as well as for a central neuromuscular junction (NMJ) and a peripheral myotendinous junction (MTJ) compartment. Comparing spatial expression patterns of wild-type mice with those of transgenic mice lacking either the skeletal muscle calcium channel CaV1.1 or ß-catenin, reveals curtailed muscle development and dysregulated expression of genes potentially involved in NMJ formation. Altogether, these datasets provide a powerful resource for further studies of muscle development and NMJ formation in the mouse.

Cadaveric study of ergonomics and performance using a robotic exoscope with a head-mounted display in spine surgery.

The conventional microscope has the disadvantage of a potentially unergonomic posture for the surgeon, which can affect performance. Monitor-based exoscopes could provide a more ergonomic posture, as already shown in pre-clinical studies. The aim of this study was to test the usability and comfort of a novel head-mounted display (HMD)-based exoscope on spinal surgical approaches in a simulated OR setting. A total of 21 neurosurgeons naïve to the device were participated in this prospective trial. After a standardized training session with the device, participants were asked to perform a single-level thoracolumbar decompression surgery on human cadavers using the exoscope. Subsequently, all participants completed a comfort and safety questionnaire. For the objective evaluation of the performance, all interventions were videotaped and analyzed. Twelve men and nine women with a mean age of 34 (range: 24-57) were participating in the study. Average time for decompression was 15 min (IqR 9.6; 24.2); three participants (14%) terminated the procedure prematurely. In these dropouts, a significantly higher incidence of back/neck pain (p = 0.002 for back, p = 0.046 for neck pain) as well as an increased frequency of HMD readjustments (p = 0.045) and decreased depth perception (p = 0.03) were documented. Overall, the surgeons' satisfaction with the exoscope was 84% (IqR 75; 100). Using a standardized, pre-interventional training, it is possible for exoscope-naïve surgeons to perform sufficient spinal decompression using the HMD-based exoscope with a high satisfaction. However, inaccurate HMD setup prior to the start of the procedure may lead to discomfort and unsatisfactory results.

Development of epithelial and mesenchymal regionalization of the human fetal utero-vaginal anlagen.

Literature on the development of the human vagina is abundant; however, contributions concerning the prenatal development of the entire utero-vaginal anlagen (UVA) are rare or carried out in rodents. The primary epithelial characteristics in the adult vagina and uterus are determined during prenatal development and depend on epithelio-mesenchymal stroma interaction; thus an investigation summarizing the spatiotemporal distribution of relevant molecular markers in the entire human UVA will be of current interest. We phenotyped epithelial and mesenchymal characteristics in sagittal sections from 24 female fetuses of 14-34 weeks of gestation and two female newborns by immunostaining with cytokeratins 8, 13, 14 and 17, p63, bcl-2, bmp4, HOX A13, CD31, VEGF, SMA, Pax2 and vimentin. Epithelial differentiation followed a caudal-to-cranial direction in the UVA. Due to the cytokeratin profile of cytokeratins 8, 13 and 14, the characteristics of the different epithelial zones in the UVA could already be recognized in middle-age fetuses. Vaginal epithelium originated from the urogenital sinus in the lower portion and initiated the transformation of vimentin-positive Müllerian epithelium in the upper vaginal portion. During prenatal development the original squamo-columnar junction was clearly detectable from week 24 onwards and was always found in the cervical canal. Early blc-2 positivity within the surrounding mesenchyme of the entire vagina including the portio region pointed to an organ-specific mesenchymal influence. Prenatal findings in human specimens clearly show that fornix epithelium up to the squamo-columnar junction is of vaginal Müllerian origin, and the cervical epithelium cranial to the squamo-columnar junction is of uterine Müllerian origin and includes cells with enough plasticity to transform into squamous epithelium.

The distance between the distal margin of the flexor retinaculum and the radiocarpal joint as a landmark in CTS surgery: A cadaver study.

BACKGROUND: The most frequent peripheral entrapment neuropathy is compression of the median nerve in the carpal tunnel, known as carpal tunnel syndrome. The most effective treatment is surgery, where the flexor retinaculum (FR) is divided. Nevertheless, after this operation, a significant number of patients suffer from persistent symptoms due to incomplete FR distal release. It may be difficult to identify the distal boundary of the FR due to the minimal skin incision. We aimed to identify an anatomical landmark to avoid incomplete distal FR release. The radiocarpal (RC) joint can be palpated, and lies in close proximity to the boundaries of the FR. Thus, the distance between the RC joint space and the distal FR margin - the RC-FR distance - could be a reliable and individual morphologic measurement from easily acquired regional anthropological measurements. METHODS: During this study, 39 radiocarpal regions of 23 embalmed cadavers were dissected, and measurements were taken. Linear regression corresponding to the ulnar length and the RC-FR distance was established. RESULTS: The mean RC-FR distance from the RC joint space to the distal FR margin was 3.8 cm (95 % CI 3.5-4.0), and the range was 2.3-5.1 cm. This distance was 1.1 cm (95 % CI 0.8-1.4) longer in males than in females (p < 0.00001), and there were no side-specific differences. The individual projection of the distal FR margin in centimeters can be calculated by measurement of the ipsilateral ulnar length divided by 4 and reduced by 2.9, p < 0.005. CONCLUSIONS: The side-equal and sex-specific position of the distal flexor retinaculum margin could be calculated from the palpable radiocarpal joint space based on the ipsilateral ulnar length.

The relationship between connexin-43 expression and Ki67 in non-glial central nervous system tumors.

BACKGROUND: Advanced intercellular communication is a known oncogenic factor. In the central nervous system, Connexin-43 (Cx43) forms this junctional networking. Moreover, it correlates with the proliferation rate, and thus behavior, of gliomas. We assessed the expression of Cx43 and its relationship to Ki67 in other common central nervous system tumors. METHODS: The expression of Cx43 and Ki67 were assessed in formalin-fixed paraffin embedded samples of human brain metastases, meningiomas, and neurinomas using immunohistochemistry. Neurinomas and meningiomas were jointly evaluated due to similar non-malignant behavior. RESULTS: A total of 14 metastases of different extracerebral carcinomas, 6 meningiomas, and 10 neurinomas were evaluated. Five (36%) metastases and 5 (31%) meningiomas/neurinomas showed minor expression, whereas 6 (43%) metastases and 2 (13%) meningiomas/neurinomas showed no Cx43 expression at all. In 3 (21%) metastases and 9 (56%) meningiomas/neurinomas, moderate or strong expression of Cx43 was identified. The higher expression of Cx43 in meningiomas and neurinomas directly correlated with Ki67, r = 0.53 (P = 0.034). For metastases no significant correlation was found. Mitotic index in meningiomas/neurinomas correlated with Ki67 expression, r = 0.74 (P < 0.001), but did not show statistically significant correlation with Cx43 expression in these tumors. CONCLUSIONS: The expression of Cx43 as a marker of cell-to-cell networking exposed a significant correlation with the Ki67-defined proliferation index in case of primary central nervous system neuroectodermal neoplasms. However, it does not seem to play a comparable role in metastases with extracerebral origin.

Impact of GAP-43, Cx43 and actin expression on the outcome and overall survival in diffuse and anaplastic gliomas.

Distant intercellular communication in gliomas is based on the expansion of tumor microtubuli, where actin forms cytoskeleton and GAP-43 mediates the axonal conus growth. We aimed to investigate the impact of GAP-43 and actin expression on overall survival (OS) as well as crucial prognostic factors. FFPE tissue of adult patients with diffuse and anaplastic gliomas, who underwent first surgery in our center between 2010 and 2019, were selected. GAP-43, Cx43 and actin expression was analyzed using immunohistochemistry and semi-quantitatively ranked. 118 patients with a median age of 46 years (IqR: 35-57) were evaluated. 48 (41%) presented with a diffuse glioma and 70 (59%) revealed anaplasia. Tumors with higher expression of GAP-43 (p = 0.024, HR = 1.71/rank) and actin (p < 0.001, HR = 2.28/rank) showed significantly reduced OS. IDH1 wildtype glioma demonstrated significantly more expression of all proteins: GAP-43 (p = 0.009), Cx43 (p = 0.003) and actin (p < 0.001). The same was confirmed for anaplasia (GAP-43 p = 0.028, actin p = 0.029), higher proliferation rate (GAP-43 p = 0.016, actin p = 0.038), contrast-enhancement in MRI (GAP-43 p = 0.023, actin p = 0.037) and age (GAP-43 p = 0.004, actin p < 0.001; Cx43 n.s. in all groups). The intercellular distant communication network in diffuse and anaplastic gliomas formed by actin and GAP-43 is associated with a negative impact on overall survival and with unfavorable prognostic features. Cx43 did not show relevant impact on OS.

Efficient mRNA detection from human archival paraffin-embedded tissue: an update.

We recently published an in situ hybridization protocol for archival tissue using a commercial hybridization buffer. This buffer is no more available. Therefore, we have developed an improved protocol with a defined hybridization buffer.

Role of puborectalis muscle in the genesis of urethral pressure.

PURPOSE: The internal (smooth muscle) and the external (rhabdosphincter striated muscle) urethral sphincters have important roles in the genesis of urethral closure pressure. The U-shaped pelvic floor puborectalis muscle is important in the closure of anal and vaginal orifices in humans. We defined the contribution of the puborectalis to urethral pressure. MATERIALS AND METHODS: A total of 11 female rabbits were anesthetized and prepared to measure urethral, vaginal and anal canal pressure using manometric methods. Pressure was recorded at rest, after administration of pharmacological agents and during electrical stimulation of the puborectalis and rhabdosphincter sphincter muscles. Phenylephrine, sodium nitroprusside (Sigma-Aldrich®) and rocuronium bromide (PharMEDium, Lake Forest, Illinois) were used to define the relative contribution of smooth and striated muscles to urethral pressure. Histology of the pelvic floor hiatus was also studied. RESULTS: At rest mean ± SEM maximum urethral pressure was 13 ± 6 mm Hg. Sodium nitroprusside (50 µg/kg) infusion resulted in a 30% to 40% decrease in resting urethral pressure (mean 7.2 ± 0.2 mm Hg). Phenylephrine produced a dose dependent increase in urethral pressure (mean 17 ± 6, 25 ± 5 and 29 ± 6 for 5, 10 and 50 µg/kg intravenously, respectively). Electrical stimulation of the puborectalis muscle induced a stimulus dependent increase in urethral, vaginal and anal canal pressure. On the other hand, rhabdosphincter stimulation induced a stimulus intensity dependent increase in urethral pressure only. The increase in urethral pressure after puborectalis muscle stimulation was more than twofold higher than after rhabdosphincter stimulation. CONCLUSIONS: Our data prove that the puborectalis, a component of the pelvic floor muscles, is an important contributor to urethral pressure in the rabbit.

Molecular characteristics and alterations during early development of the human vagina.

Unresolved questions remain concerning the derivation of the vagina with respect to the relative contributions from the Müllerian ducts, the urogenital sinus, and the Wolffian ducts. Recent molecular and cellular studies in rodents have opened up a large gap between the level of understanding of vaginal development in mice and understanding of human vaginal development, which is based on histology. To compare the findings in mice with human vaginal development and to address this gap, we analysed molecular characteristics of the urogenital sinus, Wolffian ducts, and Müllerian ducts in 8-14-week-old human specimens using immunohistochemical methods. The monoclonal antibodies used were directed against cytokeratin (CK) 14, CK19, vimentin, laminin, p63, E-cadherin, caspase-3, Ki67, HOX A13, and BMP-4. The immunohistochemical analysis revealed that, during weeks 8-9, the epithelium of the Müllerian ducts became positive for p63 as p63-positive cells that originated from the sinus epithelium reached the caudal tip of the fused Müllerian ducts via the Wolffian ducts. The lumen of the fused Müllerian ducts was closed by an epithelial plug that contained both vimentin-positive and vimentin-negative cells. Subsequently, the resulting epithelial tube enlarged by proliferation of basal p63-positive cells. The first signs of squamous differentiation were detected during week 14, with the appearance of CK14-positive cells. According to our results, all three components, namely, the urogenital sinus, Wolffian ducts, and Müllerian ducts, interacted during the formation of the human vagina. The sinus epithelium provided p63-positive cells, the Wollfian ducts acted as a 'transporter', and the Müllerian ducts contributed the guiding structure for the vaginal anlagen. Epithelial differentiation began at the end of the period studied and extended in a caudo-cranial direction. The present study is one of the first to provide up-to-date molecular correlates for human vaginal development that can be compared with the results of cell biological studies in rodents.

Diagnosis and management of pediatric urethral injuries.

OBJECTIVE: The incidence of urethral injuries in children is rare due to the fact that the urethra is short, mobile and protected by the pubic bone. The management of urethral trauma in childhood remains controversial because of the limited expertise of most urologists. MATERIAL AND METHODS: We performed a literature review by searching the Medline database for articles published between 1975 and 2010 based on clinical relevance. Electronic searches were limited to the keywords 'pediatric', 'urethral injury', 'trauma' and 'reconstruction'. RESULTS: Retrograde urethrography is considered the gold standard for diagnosis of urethral injuries. The initial management should ensure drainage of the bladder either by suprapubic cystostomy or urethral realignment if possible: in complete anterior urethral disruption as well as in children with life-threatening pelvic and intra-abdominal injuries after posterior urethral injuries, a deferred repair after 3 months is necessary. Immediate primary suturing of disrupted and dislocated urethral ends should be avoided because of high complication rates. Primary repair, however, of the defect is possible in girls avoiding a 2-stage approach. CONCLUSION: The aim of therapy is minimizing remote damages such as urethrocutaneous fistulae, periurethral diverticulae, strictures, incontinence and impotence with different therapeutic management depending on classification of the injury and the presence of life-threatening injuries.

Functional interactions between the fossa ischioanalis, levator ani and gluteus maximus muscles of the female pelvic floor: a prospective study in nulliparous women.

PURPOSE: We evaluated the role of the fossa ischioanalis (FI) in functional relations between the levator ani (LA) and gluteus maximus muscles (GM) in healthy female volunteers. METHODS: Twenty-three nulliparae were examined. Electromyogramms of LA and GM were simultaneously recorded during voluntary contraction of the pelvic floor muscles (PFM) and at rest in six body positions. The surface areas of LA (LAA), FI (FIA) and GM (GMA) were evaluated using MRI. RESULTS: Simultaneous LA and GM contractions were electromyographically observed irrespectively of body position in 97.2 %. MRI revealed synchronous movement of all structures: while LAA (-7.4 %) reduced, GMA increased (+6.8 %), FIA changed significantly (+3.4 %). CONCLUSIONS: The LA, FI and GM are morphologically and functionally connected. We recommend considering these structures as the 'LFG-Complex', emphasising the importance of this unit for functional integration of the pelvic floor. The findings of this study may contribute to understanding of urinary continence mechanism and disorders after pelvic floor surgery and obstetrical trauma.