Studies of a co-chaperone of the androgen receptor, FKBP52, as candidate for hypospadias

BACKGROUND: Hypospadias is a common inborn error of the male urethral development, for which the aetiology is still elusive. Polymorphic variants in genes involved in the masculinisation of male genitalia, such as the androgen receptor, have been associated with some cases of hypospadias. Co-regulators of the androgen receptor start being acknowledged as possible candidates for hormone-resistance instances, which could account for hypospadias. One such molecule, the protein FKBP52, coded by the FKBP4 gene, has an important physiological role in up-regulating androgen receptor activity, an essential step in the development of the male external genitalia. The presence of hypospadias in mice lacking fkbp52 encouraged us to study the sequence and the expression of FKBP4 in boys with isolated hypospadias. PATIENTS AND METHODS: The expression of FKBP52 in the genital skin of boys with hypospadias and in healthy controls was tested by immunohistochemistry. Mutation screening in the FKBF4 gene was performed in ninety-one boys with non syndromic hypospadias. Additionally, two polymorphisms were typed in a larger cohort. RESULTS: Immunohistochemistry shows epithelial expression of FKBP52 in the epidermis of the penile skin. No apparent difference in the FKBP52 expression was detected in healthy controls, mild or severe hypospadias patients. No sequence variants in the FKBP4 gene have implicated in hypospadias in our study. CONCLUSION: FKBP52 is likely to play a role in growth and development of the male genitalia, since it is expressed in the genital skin of prepubertal boys; however alterations in the sequence and in the expression of the FKBP4 gene are not a common cause of non-syndromic hypospadias

Study on the short-term effects of increased alcohol and cigarette consumption in healthy young men's seminal quality

Many studies have reported a negative impact of lifestyle factors on testicular function, spermatozoa parameters and pituitary-gonadal axis. However, conclusions are difficult to draw, since studies in the general population are rare. In this study we intended to address the early and late short-term impact of acute lifestyle alterations on young men's reproductive function. Thirty-six healthy male students, who attended the Portuguese academic festivities, provided semen samples and answered questionnaires at three time-points. The consumption of alcohol and cigarette increased more than 8 and 2 times, respectively, during the academic festivities and resulted in deleterious effects on semen quality: one week after the festivities, a decrease on semen volume, spermatozoa motility and normal morphology was observed, in parallel with an increase on immotile spermatozoa, head and midpiece defects and spermatozoa oxidative stress. Additionally, three months after the academic festivities, besides the detrimental effect on volume, motility and morphology, a negative impact on spermatozoa concentration was observed, along with a decrease on epididymal, seminal vesicles and prostate function. This study contributed to understanding the pathophysiology underlying semen quality degradation induced by acute lifestyle alterations, suggesting that high alcohol and cigarette consumption are associated with decreased semen quality in healthy young men.publishe

Vasovasostomy and predictors of vasal patency: A systematic review

About 3-6% of vasectomized men requested vasectomy reversal, for various reasons. Vasal patency (VP) is an important surrogate outcome of vasectomy reversal. This article reviews the impact of surgical skills, surgical approaches, intraoperative vasal fluid characteristics and the length of obstructive interval on VP. Based on the best available evidence, the rate of patency is related to the operative frequency of the surgeons, with better results obtained by surgeons who perform the operations at least 10 times annually. Microsurgical vasovasostomy is the preferred technique for durable good results. One-layer vasovasostomy and two-layer vasovasostomy seem to be equal with regard to VP. The rate of patency following vasovasostomy in the convoluted vas and vasovasostomy in the straight vas is comparable. The patency rate is high in men with clear intraoperative vasal fluid in at least one vas. VP is still high among patients with a long obstructive interval. In conclusion, surgical skills and intraoperative vasal fluid characteristics are the most important predictors of VP. Postoperative semen quality and the age of the female partner determine the chance of spontaneous conception in these couples

Semi-Blind Channel Estimation for Intelligent Reflecting Surfaces in Massive MIMO Systems

Intelligent reflecting surface (IRS) is considered as a promising technology for enhancing the transmission rate in cellular networks. Such improvement is attributed to considering a large IRS with high number of passive reflecting elements, optimized to properly focus the incident beams towards the receiver. However, to achieve this beamforming gain, the channel state information (CSI) should be efficiently acquired at the base station (BS). Unfortunately, the traditional pilot estimation method is challenging, because the passive IRS does not have radio frequency (RF) chains and the number of channel coefficients is proportional to the number of IRS elements. In this paper, we propose a novel semi-blind channel estimation method where the reflected channels are estimated using not only pilot but also data symbols, reducing the channel estimation overhead. The performance of the system is analytically investigated in terms of the uplink achievable sum-rate. The proposed scheme achieves higher energy and spectrum efficiency while being robust to channel estimation errors. For instance, the proposed scheme achieves an 80% increase in spectrum efficiency compared to pilot-only based schemes, for IRSs with $N=32$ elements

Advances in male reproductive surgery: Robotic-assisted vasovasostomy

It is estimated that 3-6% of all vasectomised men request vasectomy reversal for different reasons. Microsurgical vasovasostomy is the gold standard technique of vasectomy reversal. However, the microsurgical technique is time-consuming and challenging to most urological surgeons. Therefore, alternative methods of vasal anastomosis have been studied including robotic-assisted vasovasostomy. This review discusses the feasibility and practice of robotic-assisted vasovasostomy. Based on the available studies robotic-assisted vasovasostomy is feasible. The reported rate of vasal patency associated with this new technique is similar to that of microsurgical vasovasostomy. There is no clear difference between the 2 approaches in terms of operating time. Robotic-assisted vasovasostomy does not appear to afford significant advantages in the era of vasectomy reversal

Probabilistic Shaping Based Spatial Modulation for Spectral-Efficient VLC

Visible light communication (VLC) is a promising technology for 6th-generation (6G) networks because of its attractive feature such as a wide unlicensed spectrum. In this paper, a novel adaptive coded spatial modulation scheme with probabilistic shaping (PS) is proposed to approach the capacity of the spatial modulation (SM) in VLC channels with intensity modulation and direct detection (IM/DD). In the proposed scheme, spatial and constellation symbols are probabilistically shaped depending on the user's location inside the room and the optical signal-to-noise ratio (OSNR). Moreover, we optimize the channel coding rate to maximize further the achievable rate of the proposed scheme for a given OSNR. Finally, we propose an algorithm to compute the capacity-achieving distribution of the proposed scheme with unipolar M-ary pulse amplitude modulation (PAM) signaling. The proposed scheme outperforms uniform and an orthogonal frequency-division multiplexing (OFDM) based scheme in terms of spectral efficiency (SE) and/or frame error rate (FER). For example, for 8-PAM signaling with N = 8 transmit antennas, the proposed scheme operates within 0.2 dB from the unipolar M-PAM SM VLC channel signaling capacity and outperforms the uniform and OFDM based schemes in terms of FER by at least 1.1 dB and 1.3 dB at a normalized data rate of 1.33 bits per channel use per sub-carrier (b/cu/sc), respectively

Compressive Near-Field Localization For Multipath RIS-aided Environments

Reconfigurable intelligent surfaces (RISs) are considered among the key techniques to be adopted for sixth-generation cellular networks (6G) to enhance not only communications but also localization performance. In this regard, we propose a novel single-anchor localization algorithm for a state-of-the-art architecture where the position of the user equipment (UE) is to be estimated at the base station (BS) with the aid of a RIS. We consider a practical model that accounts for both near-field propagation and multipath environments. The proposed scheme relies on a compressed sensing (CS) technique tailored to address the issues associated with near-field localization and model mismatches. Also, the RIS phases are optimized to enhance the positioning performance, achieving more than one order of magnitude gain in the localization accuracy compared to RISs with non-optimized phases

Testicular biopsy: Clinical practice and interpretation

Testicular biopsy was considered the cornerstone of male infertility diagnosis for many years in men with unexplained infertility and azoospermia. Recent guidelines for male infertility have limited the indications for a diagnostic testicular biopsy to the confirmation of obstructive azoospermia in men with normal size testes and normal reproductive hormones. Nowadays, testicular biopsies are mainly performed for sperm harvesting in men with non-obstructive azoospermia, to be used for intracytoplasmic sperm injection. Testicular biopsy is also performed in men with risk factors for testicular malignancy. In a subgroup of infertile men, there is an increased risk for carcinoma in situ of the testis, especially in men with a history of cryptorchidism and testicular malignancy and in men with testicular atrophy. Ultrasonographic abnormalities, such as testicular microlithiasis, inhomogeneous parenchyma and lesions of the testes, further increase the risk of carcinoma in situ (CIS) in these men. For an accurate histological classification, proper tissue handling, fixation, preparation of the specimen and evaluation are needed. A standardized approach to testicular biopsy is recommended. In addition, approaches to the detection of CIS of the testis testicular immunohistochemistry are mandatory. In this mini-review, we describe the current indications for testicular biopsies in the diagnosis and management of male infertility