The present review provides challenges and opportunities to stimulate research and exploit Sirtuin-based signalling as diagnostic tools and potential targets for therapeutic applications in reproductive medicine.

Background Scrotal color Doppler ultrasound (CDUS) still suffers from lack of standardization. Hence, the European Academy of Andrology (EAA) has promoted a multicenter study to assess the CDUS characteristics of healthy fertile men (HFM) to obtain normative parameters. Objectives To report and discuss the scrotal organs CDUS reference ranges and characteristics in HFM and their associations with clinical, seminal, and biochemical parameters. Methods A cohort of 248 HFM (35.3 ± 5.9years) was studied, evaluating, on the same day, clinical, biochemical, seminal, and scrotal CDUS following Standard Operating Procedures. Results The CDUS reference range and characteristics of the scrotal organs of HFM are reported here. CDUS showed a higher accuracy than physical examination in detecting scrotal abnormalities. Prader orchidometer (PO)‐ and US‐measured testicular volume (TV) were closely related. The US‐assessed TV with the ellipsoid formula showed the best correlation with the PO‐TV. The mean TV of HFM was ~ 17 ml. The lowest reference limit for right and left testis was 12 and 11 ml, thresholds defining testicular hypotrophy. The highest reference limit for epididymal head, tail, and vas deferens was 12, 6, and 4.5 mm, respectively. Mean TV was associated positively with sperm concentration and total count and negatively with gonadotropins levels and pulse pressure. Subjects with testicular inhomogeneity or calcifications showed lower sperm vitality and concentration, respectively, than the rest of the sample. Sperm normal morphology and progressive motility were positively associated with epididymal head size/vascularization and vas deferens size, respectively. Increased epididymis and vas deferens sizes were associated with MAR test positivity. Decreased epididymal tail homogeneity/vascularization were positively associated with waistline, which was negatively associated with intratesticular vascularization. CDUS varicocele was detected in 37.2% of men and was not associated with seminal or hormonal parameters. Scrotal CDUS parameters were not associated with time to pregnancy, number of children, history of miscarriage. Conclusions The present findings will help in better understanding male infertility pathophysiology, improving its management.

Background Infertility affects 7%‐12% of men, and its etiology is unknown in half of cases. To fill this gap, use of the male genital tract color‐Doppler ultrasound (MGT‐CDUS) has progressively expanded. However, MGT‐CDUS still suffers from lack of standardization. Hence, the European Academy of Andrology (EAA) has promoted a multicenter study (“EAA ultrasound study”) to assess MGT‐CDUS characteristics of healthy, fertile men to obtain normative parameters. Objectives To report (a) the development and methodology of the “EAA ultrasound study,” (b) the clinical characteristics of the cohort of healthy, fertile men, and (c) the correlations of both fertility history and seminal features with clinical parameters. Methods A cohort of 248 healthy, fertile men (35.3 ± 5.9 years) was studied. All subjects were asked to undergo, within the same day, clinical, biochemical, and seminal evaluation and MGT‐CDUS before and after ejaculation. Results The clinical, seminal, and biochemical characteristics of the cohort have been reported here. The seminal characteristics were consistent with those reported by the WHO (2010) for the 50th and 5th centiles for fertile men. Normozoospermia was observed in 79.6% of men, while normal sperm vitality was present in almost the entire sample. Time to pregnancy (TTP) was 3.0[1.0‐6.0] months. TTP was negatively correlated with sperm vitality (Adj.r =−.310, P = .011), but not with other seminal, clinical, or biochemical parameters. Sperm vitality and normal morphology were positively associated with fT3 and fT4 levels, respectively (Adj.r = .244, P < .05 and Adj.r = .232, P = .002). Sperm concentration and total count were negatively associated with FSH levels and positively, along with progressive motility, with mean testis volume (TV). Mean TV was 20.4 ± 4.0 mL, and the lower reference values for right and left testes were 15.0 and 14.0 mL. Mean TV was negatively associated with gonadotropin levels and pulse pressure. Varicocoele was found in 33% of men. Conclusions The cohort studied confirms the WHO data for all semen parameters and represents a reference with which to assess MGT‐CDUS normative parameters.

Human spermatozoa express type-1 cannabinoid receptor (CB1), whose activation by anandamide (AEA) affects motility and acrosome reaction (AR). In this study, we extended the characterization of the AEA-related endocannabinoid system in human spermatozoa, and we focused on the involvement of the AEA-binding vanilloid receptor (TRPV1) in their fertilizing ability. Protein expression was revealed for CB1 ( approximately 56 kDa), TRPV1 ( approximately 95 kDa), AEA-synthesizing phospholipase D (NAPE-PLD) ( approximately 46 kDa), and AEA-hydrolyzing enzyme [fatty acid amide hydrolase (FAAH), approximately 66 kDa]. Both AEA-binding receptors (CB1 and TRPV1) exhibited a functional binding activity; enzymatic activity was demonstrated for NAPE-PLD, FAAH, and the purported endocannabinoid membrane transporter (EMT). Immunoreactivity for CB1, NAPE-PLD, and FAAH was localized in the postacrosomal region and in the midpiece, whereas for TRPV1, it was restricted to the postacrosomal region. Capsazepine (CPZ), a selective antagonist of TRPV1, inhibited progesterone (P)-enhanced sperm/oocyte fusion, as evaluated by the hamster egg penetration test. This inhibition was due to a reduction of the P-induced AR rate above the spontaneous AR rate, which was instead increased. The sperm exposure to OMDM-1, a specific inhibitor of EMT, prevented the promoting effect of CPZ on spontaneous AR rate and restored the sperm responsiveness to P. No significant effects could be observed on sperm motility. In conclusion, this study provides unprecedented evidence that human spermatozoa exhibit a completely functional endocannabinoid system related to AEA and that the AEA-binding TRPV1 receptor could be involved in the sperm fertilizing ability.

Background The aim of testosterone replacement therapy (TRT) is to improve symptoms and signs of testosterone deficiency including decreased libido, erectile dysfunction, depressed mood, anaemia, loss of muscle and bone mass, by increasing serum testosterone levels to physiologic range. TRT has been used in the last 70 years, and overtime, numerous preparations and formulations have been developed to improve pharmacokinetics (PKs) and patient compliance. The routes of delivery approved for use in the Western world include buccal, nasal, subdermal, transdermal and intramuscular (IM). Objectives The aim of this narrative review was to describe and compare all available and approved testosterone preparations according to pharmacology, PKs and adverse effects. Materials and Methods We have performed an extensive PubMed review of the literature on TRT in clinical practice. Contraindications and monitoring of TRT were analyzed by comparing available guidelines released in the last five years. We provide a review of advantages and disadvantages of different modalities of TRT and how to monitor treatment to minimize the risks. Results TRT is associated with multiple benefits highly relevant to the patient. However, the recommendations given in different guidelines on TRT are based on data from a limited number of randomized controlled trials (RCTs), as well as non‐randomized clinical studies and observational studies. This is the case for the safety of a long‐term TRT in late‐onset hypogonadism (LOH). No evidence is provided indeed on the effects of TRT on endpoints such as deterioration of heart failure suggesting a cautious approach to T replacement in older men with a history of heart failure. Conclusion Clinicians must consider the unique characteristics of each patient and make the necessary adjustments in the management of LOH in order to provide the safest and most beneficial results.