A Narrative Review Discussing Vasectomy-Related Impact upon the Status of Oxidative Stress and Inflammation Biomarkers and Semen Microbiota

Background: Male contraceptive approaches besides tubal sterilization involve vasectomy and represent the method of choice among midlife men in developing countries thanks to many advantages. However, the subsidiary consequences of this intervention are insufficiently explored since the involved mechanisms may offer insight into a much more complex picture. Methods: Thus, in this manuscript, we aimed to reunite all available data by searching three separate academic database(s) (PubMed, Web of Knowledge, and Scopus) published in the past two decades by covering the interval 2000–2023 and using a predefined set of keywords and strings involving “oxidative stress” (OS), “inflammation”, and “semen microbiota” in combination with “humans”, “rats”, and “mice”. Results: By following all evidence that fits in the pre-, post-, and vasectomy reversal (VR) stages, we identified a total of n = 210 studies from which only n = 21 were finally included following two procedures of eligibility evaluation. Conclusions: The topic surrounding this intricate landscape has created debate since the current evidence is contradictory, limited, or does not exist. Starting from this consideration, we argue that further research is mandatory to decipher how a vasectomy might disturb homeostasis.

MRI in the evaluation of the azoospermic male

PURPOSE We aimed to show the usefulness of magnetic resonance imaging (MRI) in the evaluation of infertile men and its ability to distinguish obstructive from nonobstructive azoospermia. METHODS Between April 2015 and February 2018, 45 azoospermic men underwent scrotal MRI. We evaluated the images with an emphasis on signal characteristics of the testis and morphologic changes typical for obstruction. Testicular volume (TV), apparent diffusion coefficient (ADC) value, T1 and T2 signal ratios (testis/muscle) were measured for every testis. On the basis of histologic results, patients were divided into two groups: obstructive azoospermia (OA) and nonobstructive azoospermia (NOA). RESULTS Testes of patients in the OA group had significantly lower ADC values (mean 0.876±101 ×10-3 mm2/s) than in the NOA group (mean, 1.114±147 ×10-3 mm2/s). TV was significantly higher in patients with OA (median, 17.61 mL; range, 11.1-38.4 mL) than in those with NOA (median, 10.5 mL; range, 5.2-22.2 mL). ROC analysis showed that both TV and ADC values were highly predictive for distinguishing between OA and NOA patients, with an area under the ROC curve of 0.82 and 0.92 respectively. A cutoff value of ≥12.4 mL could distinguish obstructive from nonobstructive azoospermia with a sensitivity of 92% and specificity of 63%, whereas for ADC measurements a cutoff value of ≥0.952 ×10-3 mm2/s exhibited a sensitivity of 81% and specificity of 90% There was no statistically significant difference in T1 and T2 signal ratios between both groups. Abnormalities typical for obstruction of the male reproductive tract (e.g., dilatation of ejaculatory ducts, prostatic or seminal vesicle cysts) were found in 78% of patients (14/18) in the obstructive group. CONCLUSION Scrotal MRI is a very effective tool for the evaluation of azoospermic men and may provide important information facilitating interventional treatment of infertility.

A fertility-oriented method for histological processing of testicular biopsies in men with azoospermia

The present study was designed to evaluate whether tissue preparation by glutaraldehyde and glycol methacrylate (G/GMA) improves the diagnostic assessment of testicular biopsies from azoospermic men when compared to the standard tissue preparation using Bouin's solution and paraffin. We prospectively included a total of 21 testicular biopsies of sexually mature men aged 29-50 years with infertility and azoospermia. One testicular biopsy fragment from each patient was processed by the G/GMA method, whereas another tissue fragment was contemporarily processed by the conventional Bouin/paraffin (B/P) method. The G/GMA method provided better resolution of cytological details of the seminiferous epithelium, changing the final diagnosis in four cases. The medians of Bergmann's spermatogenesis scores were 0.25 (interquartile range 0.04-0.88) for B/P preparations and 0.79 (interquartile range 0.17-0.96) for G/GMA preparations. Both techniques allowed accurate prediction of sperm recovery from the biopsies (B/P, area under the receiver operating characteristics [ROC] curve 0.88, 95% confidence interval [CI] 0.75-1.00; G/GMA, area under the ROC curve 0.94, 95% CI 0.86-1.00). We conclude that human testicular biopsy preparation with G/GMA improved image resolution under light microscopy and produced more reliable results for the evaluation of spermatogenesis in comparison with B/P, allowing a more precise fertility-oriented diagnosis in azoospermic men.Abbreviations: B/P: Bouin/paraffin; GMA: glycol methacrylate; G/GMA: glutaraldehyde and glycol methacrylate; ICSI: intracytoplasmic sperm injection; OA: obstructive azoospermia; NOA: nonobstructive azoospermia; TESE: testicular sperm extraction.

MAEL promoter hypermethylation is associated with de-repression of LINE-1 in human hypospermatogenesis

STUDY QUESTION

Does the hypermethylation of the maelstrom spermatogenic transposon silencer (MAEL) promoter and subsequent de-repression of transposable elements represent one of the causes of spermatogenic failure in infertile men?

SUMMARY ANSWER

Experimental hypermethylation of a specific region (-131 to +177) of the MAEL promoter leads to decreased expression of MAEL with increased expression of the transposable element LINE-1 (L1) and in infertile men methylation of the MAEL promoter is associated with the severity of spermatogenic failure.

WHAT IS KNOWN ALREADY

MAEL induces transposon repression in the male germline and is required for mammalian meiotic progression and post-meiotic spermiogenesis. Patients with non-obstructive azoospermia (NOA), defined as no sperm in the ejaculate due to spermatogenic failure, and histopathologically proven hypospermatogenesis (HS) is not uncommon and its etiology is largely unknown.

STUDY DESIGN, SIZE, DURATION

Luciferase reporter assay and a targeted DNA methylation model were used to explore the effects of hypermethylation of MAEL promoter on gene expression. Germ cell-enriched testicular cells from infertile patients were used to determine the methylation levels of MAEL and expressions of MAEL and L1.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Twenty-six patients with histopathologically proven NOA and HS and 12 patients with obstructive azoospermia and normal spermatogenesis (NS) were enrolled in this study. Demographic and clinical information were obtained. The severity of HS was determined by a spermatogenic scoring system. The methylation levels of 26 CpGs in the MAEL promoter was measured, and quantitative real-time RT-PCR was used to determine the expressional levels of MAEL and L1.

MAIN RESULTS AND THE ROLE OF CHANCE

Targeted DNA methylation of MAEL promoter suppressed MAEL expression and de-repressed L1 activity in vitro. Patients with HS had significantly higher mean methylation levels of 26 consecutive CpGs in the MAEL promoter, compared to patients with NS. The MAEL methylation levels were negatively correlated with MAEL transcript levels and higher methylation level of MAEL was associated with severe spermatogenic defect. L1 transcript level was significantly higher in patients with HS. No differences in age, frequency of testicular insults and genetic anomalies was noted between patients with high or low MAEL methylation levels.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Because of the difficulty in the use of human germ cells for study, the in vitro targeted DNA methylation model was performed by using human NCI-H358 cells to explore the effects of MAEL methylation on transposable elements activity. Because the germ cell-enriched testicular cells isolated from a testicular sample were relatively few, the purity of cell populations was not determined.

WIDER IMPLICATIONS OF THE FINDINGS

Measurement of the methylation level of MAEL gene may be feasible to predict the severity of spermatogenic failure or the outcome of testicular sperm retrieval.

STUDY FUNDING/COMPETING INTERESTS

This work was supported through grants from the Ministry of Science and Technology of Taiwan (100-2314-B-006-017) and National Cheng Kung University Hospital, Tainan, Taiwan (NCKUH 20120266). The authors declare no conflicts of interest.

Spontaneous Reproductive Tract Lesions in Aged Captive Chimpanzees

Chimpanzees (Pan troglodytes) have served as an important model for studies of reproductive diseases and aging-related disorders in humans. However, limited information is available about spontaneously occurring reproductive tract lesions in aging chimpanzees. In this article, the authors present histopathologic descriptions of lesions identified in the reproductive tract, including the mammary gland, of 33 female and 34 male aged chimpanzees from 3 captive populations. The most common findings in female chimpanzees were ovarian atrophy, uterine leiomyoma, adenomyosis, and endometrial atrophy. The most common findings in male chimpanzees were seminiferous tubule degeneration and lymphocytic infiltrates in the prostate gland. Other less common lesions included an ovarian granulosa cell tumor, cystic endometrial hyperplasia, an endometrial polyp, uterine artery hypertrophy and mineralization, atrophic vaginitis, mammary gland inflammation, prostatic epithelial hyperplasia, dilated seminal vesicles, a sperm granuloma, and lymphocytic infiltrates in the epididymis. The findings in this study closely mimic changes described in the reproductive tract of aged humans, with the exception of a lack of malignant changes observed in the mammary gland and prostate gland.

Testicular histological and immunohistochemical aspects in a post-pubertal patient with 5 alpha-reductase type 2 deficiency: case report and review of the literature in a perspective of evaluation of potential fertility of these patients

BACKGROUND

Testicular morphology and immunohistochemical studies have never been reported in genetically documented adult patients with 5 alpha-reductase type 2 deficiency (5α-R2 deficiency).

CASE PRESENTATION

We describe the testicular histopathology of a 17-year-old XY subject with 5α-R2 deficiency caused by the recurrent homozygous Gly115Asp loss of function mutation of the SRD5A2 gene.We also performed an immunohistochemical analysis in order to further study the relationship between seminiferous tubules structure, Sertoli cell differentiation and androgenic signaling impairment in this case. We thus evaluated the testicular expression of the anti-Müllerian hormone (AMH), androgen receptor (AR) and 3β-hydroxysteroid dehydrogenase (3βHSD). Histological analysis revealed a heterogeneous aspect with a majority (92%) of seminiferous tubules (ST) presenting a mature aspect but containing only Sertoli cells and devoid of germ cells and spermatogenesis. Focal areas of immature ST (8%) were also found. Testicular AR and 3βHSD expression were detected in adult male control, 5α-R2 deficiency and CAIS subjects. However, AMH expression was heterogeneous (detectable only in few AR negative prepubertal ST, but otherwise repressed) in the 5α-R2 deficiency, conversely to normal adult testis in which AMH was uniformly repressed and to an adult CAIS testis in which AMH was uniformly and strongly expressed.

CONCLUSION

Intratesticular testosterone can repress AMH by itself, independently of its metabolism into dihydrotestosterone. We also compare our results to the few post pubertal cases of 5α-R2 deficiency with available histological testicular description, reported in the literature. We will discuss these histological findings, in the more general context of evaluating the fertility potential of these patients if they were raised as males and were azoospermic.

Intérêt de la ponction épididymaire et de la biopsie testiculaire systématique dans la prise en charge de l’azoospermie obstructive

Introduction

Dans l’azoospermie obstructive (AO), les taux d’extraction chirurgicale de spermatozoïdes sont élevés. Cependant, en ce qui concerne les issues des ICSI (Intra cytoplasmic Sperm Injection) chirurgicales, les données de la littérature divergent. Quels sont, dans notre équipe, les taux d’extraction de spermatozoïdes après aspiration épidydimaire (MESA) et après extraction testiculaire (TESE) dans l’AO ? Les taux de grossesses, les taux de fausses couches spontanées et d’accouchements diffèrent-ils en fonction de l’origine du sperme ?

Matériels et méthodes

L’étude a rétrospectivement inclus 48 couples dont l’homme présente une azoospermie obstructive pure et ayant bénéficié d’un prélèvement chirurgical de spermatozoïdes associant systématiquement MESA et TESE. Les ICSI ont été réalisées de manière asynchrone. À chaque fois que cela était possible, la première ICSI a été réalisée avec des spermatozoïdes épididymaires.

Résultats

Pour les 48 couples, 99 ICSI ont été réalisées. Quinze couples ont réalisé 24 ICSI-TESE car l’aspiration épididymaire était négative. Onze couples ont réalisé 20 ICSI-TESE car la qualité du prélèvement épididymaire n’était pas satisfaisante (vitalité spermatique réduite le plus souvent). Vingt-deux couples ont réalisé 22 ICSI-MESA en première intention puis en cas d’échec, 11 couples ont réalisé 12 ICSI-MESA et dix couples ont réalisé 20 ICSI-TESE. Alors que les nombres d’ovocytes injectés (7,1±4,1 vs 6,9 ±3,6 P: 0,8) et d’embryons obtenus (4,5±3,0 vs 4,7±2,7; P: 0,7) ne sont pas significativement différents dans les deux groupes d’ICSI, les nombres d’embryons de top qualité (2,4±1,9 vs 3,6±2,0 P: 0,005) et d’embryons congelés (0,9±1,8 vs 1,7±1,9 P: 0,04) sont significativement supérieurs dans le groupe TESE. Le nombre de grossesse par ponction est supérieur dans le groupe TESE (58,5 % vs 26,5 %, P: 0,002).

Conclusion

L’approche de notre centre a la particularité d’associer systématiquement un prélèvement testiculaire au prélèvement épididymaire chez tout homme présentant une azoospermie obstructive alors que la plupart des autres études rapportées se limitent à l’exploration épididymaire si cette dernière est positive lors de l’examen extemporané. Alors que classiquement, on rapporte 100% de positivité lors du prélèvement épididymaire chez l’homme atteint d’une azoospermie obstructive, dans notre étude, plus de la moitié des explorations épididymaires s’est avérée inexploitable. La qualité embryonnaire et les taux de grossesses sont meilleurs avec des spermatozoïdes testiculaires. L’association de ces 2 sites de prélèvement (MESA et TESE) peut être complémentaire et utile pour le couple et l’issue de sa prise en charge en AMP sans pour autant entraîner un sur-risque pour l’homme dans les suites de la chirurgie.