The presence of classical components of the renin-angiotensin system has been demonstrated in the male reproductive tract, mainly in the testes and epididymis. The objective of this study was to verify the localization of angiotensin (Ang)-(1-7) and its receptor Mas in human testis. The study included 12 men with previously proven fertility submitted to orchiectomy for prostate cancer and 20 infertile men submitted to testicular biopsy for infertility work-up, comprising a subgroup with obstructive azoospermia/normal spermatogenesis (n = 8) and another with non-obstructive azoospermia and severely impaired spermatogenesis (n = 12). Testicular tissue samples were processed by immunohistochemistry and real time polymerase chain reaction. Ang-(1-7) was strongly expressed in the interstitial compartment, mainly in Leydig cells, with similar intensity in all groups evaluated. The peptide was also detected in the seminiferous tubules, but with much less intensity compared to interstitial cells. The receptor Mas was equally distributed between interstitial and tubular compartments and was found in all layers of the normal seminiferous epithelium. However, neither Ang-(1-7) nor Mas were detected in the seminiferous tubules of samples with impaired spermatogenesis. The testicular samples of infertile men with impaired spermatogenesis (non-obstructive azoospermia) expressed Mas and ACE2 mRNA at lower concentrations (fold change = 0.06 and 0.04, respectively, P < 0.05) than samples with full spermatogenesis (obstructive azoospermia). This shows, for the first time, the immunolocalization of Ang-(1-7) and its receptor Mas in testes of fertile and infertile men, and suggests that this system may be altered when spermatogenesis is severely impaired.

The vasodilator/antiproliferative peptide angiotensin-(1-7) [ANG-(1-7)] is released into the corpus cavernosum sinuses, but its role in erectile function has yet to be defined. In this study, we sought to determine whether ANG-(1-7) and its receptor Mas play a role in erectile function. The ANG-(1-7) receptor Mas was immunolocalized in rat corpus cavernosum by confocal microscopy. Infusion of ANG-(1-7) into corpus cavernosum at a rate of 15.5 pmol x kg(-1) x min(-1) potentiated the elevation of the corpus cavernosum pressure induced by electrical stimulation of the major pelvic ganglion (MPG) in rats. The facilitatory effect of ANG-(1-7) was completely blunted by the specific ANG-(1-7) receptor blocker A-779 and N(omega)-nitro-L-arginine methyl ester. Nitric oxide (NO) release in the corpus cavernosum was evaluated with the fluorescent dye 4-amino-5 methylamino-2',7'-difluorofluorescein diacetate. Electrical stimulated-release of NO in rat corpus cavernosum was potentiated by ANG-(1-7). Furthermore, incubation of rat and mouse corpus cavernosum strips with ANG-(1-7) at 10 nmol/l resulted in an increase of NO release. This effect was completely abolished in mas-deficient mice. More importantly, genetic deletion of Mas resulted in compromised erectile function as demonstrated by penile fibrosis and severely depressed response to electrical stimulation of the MPG. Furthermore, the attenuated erectile function of DOCA-salt hypertensive rats was fully restored by ANG-(1-7) administration. Together these data provide strong evidence for a key role of the ANG-(1-7)-Mas axis in erectile function.

SUMMARYThe rate of motile sperm recovery after cryopreservation is very variable and difficult to predict. Anti-M€ ullerian hormone (AMH) and inhibin B are produced by Sertoli cells and released into the seminal plasma, where they could be functional markers of spermatogenesis and sperm resistance to thermal stress. The aim of this study was to evaluate whether seminal plasma levels of AMH and inhibin B predict sperm recovery after cryopreservation. The study included 153 men enrolled prospectively during a semen analysis. The cohort was stratified by the fresh semen characteristics into: normal (n = 52), high sperm count (n = 55), asthenozoospermia (n = 23), and oligozoospermia (n = 23). The main outcome measure was motile sperm recovery rate, defined as post-thaw total motile sperm count 9 100/pre-freezing total motile sperm count. In men with asthenozoospermia there was a significant correlation between motile sperm recovery rate and the pre-freezing concentrations of AMH (r = 0.522, p < 0.05) and inhibin B (0.471, p < 0.05). In this group, the areas under the receiver operating characteristic curves of AMH and inhibin B for prediction of ≥50% motile sperm recovery after cryopreservation were, respectively, 0.808 and 0.638. AMH was particularly useful, with sensitivity of 0.85, specificity of 0.80, positive predictive value of 0.84 and negative predictive value of 0.80. The sensitivity, specificity, positive, and negative predictive values of inhibin B for the same outcome were, respectively, 0.62, 0.60, 0.67, and 0.55. The median motile sperm recovery rate was 83% when seminal plasma AMH concentration was ≥0.84 ng/mL, vs. 27% when AMH concentration was <0.84 ng/ mL (p < 0.05). In other patient groups, there was no correlation between the two hormone levels in seminal plasma and the motile sperm recovery rate. In conclusion, seminal plasma AMH and inhibin B concentrations correlate with and can be used to predict motile sperm recovery after semen cryopreservation in asthenozoospermic men.

Human spermatogonial stem cells (SSCs) are an essential source to maintain spermatogenesis as an efficient process for daily sperm production with high self-renewal capacity along adulthood. However, the phenotype and the subpopulation that represent the real reserve SSC for the human testis remain unknown. Moreover, although SSC markers have been described for undifferentiated spermatogonia (Adark and Apale), the existence of a specific subtype that could be identified as the actual/true SSC has not yet been fully determined. Herein we evaluated spermatogonial morphology, kinetics, positioning regarding blood vasculature in relation to protein expression (UTF1, GFRA1, and KIT) as well as proliferative activity (MCM7) and identified a small subpopulation of Adark with nuclear rarefaction zone (AdVac) that behaves as the human reserve SSC. We show that AdVac is the smallest human spermatogonial population (10%), staying quiescent (89%) and positioned close to blood vessels throughout most of the stages of the seminiferous epithelium cycle (SEC) and divides only at stages I and II. Within this AdVac population, we found a smaller pool (2% of A undifferentiated spermatogonia) of entirely quiescent cells exhibiting a high expression of UTF1 and lacking GFRA1. This finding suggests them as the real human reserve SSC (AdVac UTF1+/GFRA1-/MCM7-). Additionally, Adark without nuclear vacuole (AdNoVac) and Apale have similar kinetic and high proliferative capacity throughout the SEC (47%), indicating that they are actively dividing undifferentiated spermatogonia. Identification of human stem cells with evident reserve SSC functionality may help further studies intending to sort SSCs to treat male diseases and infertility.

Not applicable.

N euroiNterveNtioNal procedures have become a significant asset in the treatment of cerebrovascular disorders. Training in these techniques requires several years of dedicated study to develop an understanding of and the haptic feel for catheter navigation and interventional treatments. However, medicolegal concerns and work hour restrictions may limit the experience trainees receive. Simulators allow trainees to improve their technical expertise and also allow physicians and industry to collaborate in the development of innovative devices. 3The ideal training model should be inexpensive, readily available, and have haptic characteristics similar to those encountered in the endovascular treatment of human disorders. Animal and computer-based models have been developed for this purpose. 3,5,7 While each model has certain advantages and disadvantages, it is difficult to reproduce all the haptic qualities necessary for these procedures using virtual simulators or animal models.4,6-8 Thus, it is necessary to continue to develop and research new techniques for neurointerventional training. In this article, we abbreviatioNs GDC = Guglielmi detachable coil; HP = human placenta. obJective The development of neurointerventional treatments of central nervous system disorders has resulted in the need for adequate training environments for novice interventionalists. Virtual simulators offer anatomical definition but lack adequate tactile feedback. Animal models, which provide more lifelike training, require an appropriate infrastructure base. The authors describe a training model for neurointerventional procedures using the human placenta (HP), which affords haptic training with significantly fewer resource requirements, and discuss its validation. methods Twelve HPs were prepared for simulated endovascular procedures. Training exercises performed by interventional neuroradiologists and novice fellows were placental angiography, stent placement, aneurysm coiling, and intravascular liquid embolic agent injection. results The endovascular training exercises proposed can be easily reproduced in the HP. Face, content, and construct validity were assessed by 6 neurointerventional radiologists and 6 novice fellows in interventional radiology. coNclusioNs The use of HP provides an inexpensive training model for the training of neurointerventionalists. Preliminary validation results show that this simulation model has face and content validity and has demonstrated construct validity for the interventions assessed in this study.

Human placentas are useful haptic models to simulate brain tumor microsurgical removal. Results using this model demonstrate face, content, and construct validity.

Purpose: To develop and validate a new test of specific technical skills required for microsurgical varicocelectomy. Materials and Methods: An electronic questionnaire was sent to 558 members of the Brazilian Society of Urology for the validation of the task-specific checklist (TSC) for assessment of microsurgical varicocelectomy. Participants who had experience in this procedure were selected as judges. For construct validation, 12 participants including attending urologists and urological residents in training were recruited for voluntary participation. We formed a group of three experts and a group of nine novices, who had to perform the steps of microsurgical varicocelectomy on a simulation model using human placenta. Each participant was filmed and two blinded raters would then evaluate their performance using the TSC of microsurgical varicocelectomy. Results: 14 judges were recruited. The assessment tool was reformulated, according to the judges suggestions and had the content validity achieved. The final version of the TSC was comprised of the task-specific score, a series of 4 items scored in a binary fashion designed for microscopic sub-inguinal varicocelectomy. The differences between the performance of participants with different levels of experience reflected the construct validity. The reliability between the raters was high. The mean time required to complete the training of microsurgical varicocelectomy in simulation model was significantly shorter for experts compared to novices (201 vs. 496 seconds, p=0.01). Conclusions: This preliminary study suggests that the task-specific checklist of microsurgical varicocelectomy is reliable and valid in assessing microsurgical skills.