The usefulness and significance of assessing rapidly progressive spermatozoa

Analytical variability and interpretation of results of a 3-category sperm motility assessment: 5 years' of an Australian external quality assurance programme

RESEARCH QUESTION

How do laboratories perform when assessing sperm motility with a 3-category system and interpreting results as per the fifth edition of the World Health Organization manual (WHO5), and will the use of a 4-category system as per the sixth edition of the WHO manual improve their performance?

DESIGN

Eighty video recordings of sperm samples were sent to over 200 laboratories spanning a 5-year period for the assessment of progressive motility. The results were reviewed relative to the all-laboratory trimmed mean (ALTM) in terms of the minimum and maximum values reported, the coefficient of variation and the proportion of laboratories indicating an abnormal result. A further 20 video recordings were sent over 1 year, with 6-11 laboratories per distribution adjusting to reporting rapid progressive motility using the 4-category system.

RESULTS

For the 3-category system, the videos covered a mean assessed progressive motility range of 12.0-81.1%. The mean difference between the minimum and maximum values per sample was 50.3% and the coefficients of variation were negatively correlated with the ALTM (r = -0.87, P < 0.00001). Progressive motility abnormality reporting formed a sigmoid curve, and the inflection point (50% of laboratories identifying an abnormality) gave an ALTM value of 32.01%. Preliminary results for laboratories using the 4-category system showed no performance improvement but the number of laboratories was small.

CONCLUSIONS

Analytical variation can result in laboratories crossing the clinical cut-off of the lower reference limit for samples whose motility is close to the WHO5 lower reference limit, but is less important for samples with extreme values. The benefits of a 4-category motility system are yet to be shown.

Sperm Cryopreservation Today: Approaches, Efficiency, and Pitfalls

The cryopreservation of human spermatozoa has been an option for patients undergoing chemo or radiotherapies since the late 1950s. Presently, there are different techniques for the cryopreservation of spermatozoa. The most commonly used techniques are programmable slow freezing and freezing on liquid nitrogen vapors, while the use of vitrification is still not accepted as clinically relevant. Although there have been many improvements, the ideal technique for achieving better post-thaw sperm quality continues to be a mystery. A major obstacle during cryopreservation is the formation of intracellular ice crystals. Cryodamage generated by cryopreservation causes structural and molecular alterations in spermatozoa. Injuries can happen because of oxidative stress, temperature stress, and osmotic stress, which then result in changes in the plasma membrane fluidity, motility, viability, and DNA integrity of the spermatozoa. To prevent cryodamage as much as possible, cryoprotectants are added, and in some clinical trial cases, even antioxidants that may improve post-thaw sperm quality are added. This review discusses cryopreservation techniques, cryodamage on molecular and structural levels, and cryoprotectants. It provides a comparison of cryopreservation techniques and describes recent advances in those techniques.

High-DNA integrity sperm selection using rheotaxis and boundary following behavior in a microfluidic chip

Rheotaxis, as one of the main natural guidance mechanisms in vivo, has been used in microfluidics to separate motile sperm. However, the lack of DNA integrity assessment and the inability to separate the cells in a specific reservoir have been the main limitations for the practical application of most of the devices using rheotaxis for sperm separation. Here, we present a microfluidic chip that can separate highly motile sperm using their inherent rheotaxis and boundary-following behavior in a network of boomerang-shaped microchannels. The device design is informed by our FEM simulation results to predict sperm trajectories. Experimental results demonstrate the device's performance to separate over 16 000 motile sperm in under 20 min, sufficient for droplet-based IVF. Separated cells are classified into two motility groups, highly motile (swimming speed > 120 μm s^-1) and motile (swimming speed < 120 μm s^-1). The device selects sperm with over 45%, 20%, and 80% improvement in motility, the number of highly motile sperm, and DNA integrity, respectively, suggesting promising potential for applications in assisted reproduction.

Resveratrol ameliorates bisphenol A-induced testicular toxicity in adult male rats: a stereological and functional study

BACKGROUND

Bisphenol A (BPA) is one of the most widely used synthetic chemicals worldwide. BPA as an endocrine disruptor affects the reproductive systems through estrogenic and antiandrogenic proprieties. Resveratrol (RES) as a natural polyphenol and potent antioxidant exhibits protective effects against reproductive toxicity by inhibiting of oxidative stress. 48 male rats were divided into eight groups (n=6), including CONTROL, OLIVE OIL (0.5 ml/ day), Carboxy methylcellulose (CMC) (1 ml of 10 g/l), RES (100mg/kg/day), low dose of BPA (25 mg/kg/day), high dose of BPA (50 mg/kg/day), low dose of BPA + RES, and high dose of BPA + RES. All treatments were done orally per day for 56 days. At the end of the 8th week, blood samples were collected for hormone assays. Then, the sperm parameters were analyzed, and the left testis was removed for stereological study.

RESULTS

We showed a significant decrease in sperm parameters in the low and high doses of BPA groups compared to control groups (P<0.05). The volume of testicular components as well as the diameter and length of seminiferous tubules significantly reduced (11-64 %), and the total number of the testicular cell types decreased (34-67 %) on average in the low and high doses of BPA groups. Moreover, serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone hormones concentration showed a significant reduction in both doses of BPA groups (P<0.01). Nonetheless, treatment with RES could ameliorate all the above-mentioned changes in the low and high doses of BPA groups (P<0.05).

CONCLUSIONS

RES could prevent BPA-induced testicular structural changes and sperm quality via improving gonadotropin hormones and testosterone levels.

Metabolomics of Human Semen: A Review of Different Analytical Methods to Unravel Biomarkers for Male Fertility Disorders

Background: Human life without sperm is not possible. Therefore, it is alarming that the fertilizing ability of human spermatozoa is continuously decreasing. The reasons for that are widely unknown, but there is hope that metabolomics-based investigations may be able to contribute to overcoming this problem. This review summarizes the attempts made so far. Methods: We will discuss liquid chromatography–mass spectrometry (LC-MS), gas chromatography (GC), infrared (IR) and Raman as well as nuclear magnetic resonance (NMR) spectroscopy. Almost all available studies apply one of these methods. Results: Depending on the methodology used, different compounds can be detected, which is (in combination with sophisticated methods of bioinformatics) helpful to estimate the state of the sperm. Often, but not in all cases, there is a correlation with clinical parameters such as the sperm mobility. Conclusions: LC-MS detects the highest number of metabolites and can be considered as the method of choice. Unfortunately, the reproducibility of some studies is poor, and, thus, further improvements of the study designs are needed to overcome this problem. Additionally, a stronger focus on the biochemical consequences of the altered metabolite concentrations is also required.

Evaluation of selected semen parameters and biomarkers of male infertility - preliminary study

Background: Because the etiopathogenesis of male infertility is multifactorial our study was designed to clarify the relationship between standard semen parameters, testicular volume, levels of reproductive hormones and the fragmentation of sperm nuclear DNA (SDF). Methods: Patients (n = 130) were clustered as subjects: 1) with an abnormal volume (utrasonography) of at least one testis (<12 mL) or with a normal volume of testes and 2) with abnormal levels of at least one of the reproductive hormones (FSH, LH, PRL, TSH, total T - electrochemiluminescence method) or with normal hormonal profiles and 3) with high level of SDF (>30%), moderate (>15-30%) or low (≤15%) (sperm chromatin dispersion test). Results: In subjects with a decreased testicular volume and in subjects with abnormal levels of reproductive hormones, decreased basic semen parameters were found. Participants with abnormal testicular volume had a higher percentage of SDF and a higher level of FSH (Mann-Whitney U test). In turn, men with a high level of SDF had lower testicular volume and conventional sperm parameters than men with a low level of SDF (Kruskal-Wallis test). Conclusions: We showed that spermatogenesis disorders coexisted with decreased testicular volume and increased FSH levels. The disorders of spermatogenesis were manifested by reduced basic sperm characteristics and a high level of sperm nuclear DNA damage.

ICSI outcomes for infertile men with severe or complete asthenozoospermia

BACKGROUND

Severe or complete asthenozoospermia is a rare entity that can lead to male infertility. In this study, we explored whether different extents of severe or complete asthenozoospermia could affect intracytoplasmic sperm injection (ICSI) outcomes and compared the ICSI outcomes using testicular spermatozoa with those using ejaculated spermatozoa in couples with complete asthenozoospermia.

RESULTS

Ninety-seven couples with severe or complete asthenozoospermia who underwent ICSI between January 2014 and December 2018 were included. According to the sperm category used in ICSI, patients were categorized into four groups: ejaculated progressive motile sperm group (Ep-group), ejaculated non-progressive motile sperm group (En-group), ejaculated immotile sperm group (Ei-group), and testicular sperm group (TESE-group). We compared the baseline characteristics, hormone profile, semen parameters, normal fertilization, good-quality embryos on day 3, transferred embryos, and ICSI outcomes in the four groups. The clinical pregnancy rate was significantly increased in the Ep-group (65.4%, P = 0.019) and TESE-group (63.6%, P = 0.035) compared with that in the Ei-group (23.1%). The ongoing pregnancy rate in the Ei-group was significantly lower than that in the Ep-group (23.1% vs. 61.5%, P = 0.041). Moreover, the biochemical pregnancy rate, ongoing pregnancy rate, and live birth rate were much lower in the Ei-group than in the TESE-group (30.8% vs. 63.6%, 23.1% vs. 40.4% and 23.1% vs. 40.4%, respectively).

CONCLUSIONS

In couples with complete asthenozoospermia, testicular spermatozoa should be preferred to ejaculated spermatozoa for obtaining a better ICSI outcome. With the appropriate selection of testicular spermatozoa, the extent of severe or complete asthenozoospermia may not affect the ICSI outcomes. Future studies with a larger sample size are warranted to validate these findings.

Is seminal quality worsening? A 20-year experience in Córdoba, Argentina

PURPOSE

To assess the possible variations in semen quality during the last 20 years in Córdoba, Argentina, and to identify possible causal lifestyle or genitourinary factors.

METHODS

Retrospective study of 23,130 patients attending an andrology laboratory. The 20-year period (2001-2020) was divided into four quinquenniums. Seminal parameters (sperm concentration, motility, morphology, viability, and membrane functional integrity) were classified as normal or abnormal according to WHO, and results were expressed as percentage of patients abnormal for each parameter per quinquennium. In addition, the percentage of patients per quinquennium exposed to the different risk factors (daily alcohol and/or tobacco consumption; occupational exposure to heat or toxics; history of parotitis or varicocele; and high body mass index, BMI) was reported.

RESULTS

Patients included in our study did not show impairment in seminal quality over time. Beyond a transient decrease in normozoospermia in the second and third quinquennium, possibly explained by a parallel increase in teratozoospermia, other important parameters of the spermogram did not change. In fact, abnormalities in sperm concentration (oligozoospermia), total sperm count, viability and response to hypoosmotic test showed a decreasing trend over time. On the other hand, parotitis, varicocele, morbid obesity and regular exposition to heat/toxics were the factors more frequently associated with semen abnormalities; the last two increased their frequency over the study period.

CONCLUSION

The population included in this study did not show a clear impairment in semen quality during the last 20 years. The decreasing patterns found were associated with high BMI and exposure to heat/toxics.

Sperm motility in asthenozoospermic semen samples can be improved by incubation in a continuous single culture medium (CSCM®)

Standard protocols for clinical in vitro fertilization (IVF) laboratories recommend incubating semen at 37°C in 5% CO₂ without strictly specifying which medium should be used or for how long. This study aimed to test the most common different incubation media used in Latin American andrology and micromanipulation laboratories and verify which, if any, is the most appropriate medium to improve asthenozoospermic semen samples' motility in the infertile male population. Ejaculates (136) collected from asthenozoospermic men were divided into two cohorts with similar characteristics (cohort 1; n = 28 and cohort 2; n = 108). Cohort 1 was used to evaluate the optimal incubation time with regard to unprepared asthenozoospermic sample sperm motility. After defining an optimal incubation period of 2 h, cohort 2 was used to evaluate which of the four media commonly used in IVF clinics (continuous single culture medium = CSCM®; SpermRinse medium = SR®; in vitro fertilization medium = G-IVF® and human tubal fluid medium = HTF®) was preferred for semen samples from asthenozoospermic patients. Overall, it was determined that a 2-h incubation in CSCM® medium led to the highest asthenozoospermic sperm motility. Thus, this simple, cost-effective, easily reproducible protocol could prove extremely useful for andrology laboratories working with IVF clinics dealing with asthenozoospermic semen specimens. This is particularly relevant since the incidence of the latter is on the rise as semen quality decreases around the globe.Abbreviations: ANOVA: Analysis of variance; ARTs: Assisted reproductive techniques; BWW: Biggers, Whitten, and Whittingham; CO₂: Carbon dioxide; CPM: counted per minute; CSCM: Continuous Single Culture Medium; DAB: 3.3'- diaminobenzidine; DFI: DNA Fragmentation Index; DMSO: Dimethyl sulfoxide; G-IVF: In Vitro Fertilization Medium; GSH: Glutathione; GPx: glutathione peroxidase; HDS: High DNA Stainability; HSA: Human Serum Albumin; HTF: Human Tubal Fluid; HYP: Hyperactivity; ICSI: Intracytoplasmic sperm injection; IUI: Intrauterine insemination; IVF: in vitro fertilization; LIN: Linearity; ROS: Reactive Oxygen Species-level; SC: Sperm concentration; SCA: Sperm Computer Analysis; SCSA: Sperm Chromatin Structural Assay; SR: SpermRinse medium; SSS: Synthetic Serum Substitute; STR: Straightness; SOD: superoxide dismutase; TNE: Tris-Borate-EDTA; TSC: Total sperm count; VAP: Mean velocity; VCL: Curvilinear velocity; VSL: Linear velocity; WHO: World Health Organization; WOB: Wobble; spz: spermatozoa; AO: antioxidant.

The sixth edition of the WHO manual on semen examination: ensuring quality and standardization in basic examination of human ejaculates

A basic semen investigation has established principles that are necessary for ascertaining reliable and internationally comparable results. Although these principles have been present in the WHO manual since its inception, the baseline issue across most published studies and practice in reproductive medicine (in which the male is considered) is repetitive failure to adhere to these principles, thereby leading to relevant comparable data and accuracy. To address this failure, the sixth edition of the WHO manual includes revised basic methods, and a complementary formal standard of the International Standards Organization (ISO23162:2021) for basic semen examination has been published. Perhaps the most significant change in the sixth edition is the reintroduction of the four-category distinction of sperm motility, which causes additional work for laboratories in changing reporting parameters but is clinically important. Another essential change is the widened focus from mainly a prognostic tool for medically assisted reproduction to additionally raising awareness of semen examination as a measure of male reproductive functions and general male health.

The Sixth Edition of the WHO Manual for Human Semen Analysis: A Critical Review and SWOT Analysis

Semen analysis is the cornerstone of male fertility evaluation with WHO guidelines providing the basis for procedural standardization and reference values worldwide. The first WHO manual was published in 1980, and five editions have been subsequently released over the last four decades. The 6th Edition was published in July 2021. In this review, we identify the key changes of this 6th Edition. Additionally, we evaluate the utility of this 6th Edition in clinical practice using SWOT (strengths, weaknesses, opportunities, and threats) analysis. This new Edition has made the analysis of basic semen parameters more robust, taking into account the criticisms and grey areas of the previous editions. The tests assessing sperm DNA fragmentation and seminal oxidative stress are well-described. The main novelty is that this latest edition abandons the notion of reference thresholds, suggesting instead to replace them with “decision limits”. While this seems attractive, no decision limits are proposed for either basic semen parameters, or for extended or advanced parameters. This critical review of the 6th Edition of the WHO laboratory manual combined with a SWOT analysis summarizes the changes and novelties present in this new Edition and provides an in-depth analysis that could help its global use in the coming years.

Human sperm morphology assessment since 2010: experience of an Australian external quality assurance programme

RESEARCH QUESTION

Which classification criteria of sperm normality were used after the publication of the World Health Organization (WHO) 5th Edition manual (WHO5), and how did the laboratories perform?

DESIGN

Semen samples were sent to enrolled laboratories over a 10-year period for the determination of the proportion of spermatozoa with normal morphology. The coefficient of variation was used to indicate the level of precision between laboratories.

RESULTS

Before the publication of WHO5, at least six different classification criteria were in use. After 2010, WHO5 was quickly adopted, with 50% of laboratories using WHO5 criteria after the first 2 years, increasing to 94% after 10 years. Reported normal forms by WHO3 and WHO4 users remained consistent; however, the morphology results for each distribution declined significantly over time for WHO5 users (P < 0.001), suggesting laboratories were becoming stricter in their identification of normal spermatozoa. The precision of WHO5 users improved over time as shown by a steady decline in the coefficients of variation.

CONCLUSIONS

The introduction of WHO5 resulted in the effective adoption of its morphology classification system, with laboratories showing improved between-laboratory variation over time; however, the identification of normal forms by WHO5 users over time was inconsistent, as laboratories became stricter. Given the reduction in reported normal forms by WHO5 users, it seems that increased training of laboratory personnel or the consideration of validated objective automated analysers in the assessment of sperm morphology would seem warranted.

Fresh semen characteristics in captive accipitrid and falconid birds of prey

Artificial insemination (AI) is the most frequently used assisted reproductive technique for captive propagation of rare avian species. As semen quality is critical for reproductive success, baseline data are needed for evaluating and selecting the best male bird donors. To this end, we used computer-assisted semen analysis to assess male eastern imperial eagles (n = 7), northern goshawks (n = 24) and peregrine falcons (n = 20). While imperial eagles and northern goshawks donate ejaculate voluntarily, peregrine falcons required cloacal massage. Eight peregrine falcon females were inseminated with semen from eight males, with fresh ejaculates (15 to 50 µl) applied to the pars uterina of the oviduct immediately after collection and examination. All females were inseminated within 2 h of laying an egg. A fertilization rate of 70% was achieved using this method. Minimum semen characteristics associated with egg fertilization included a semen concentration of 115.12 × 106/ml, 33.52% total motility, 1.92% spermatozoa with progressive motility and 0.17% with rapid motility. Comparative data on spermatozoa concentration and kinematics suggest that eastern imperial eagles concentrate on high quality semen investment at the start of the breeding season, northern goshawks compensate for a decrease in motility-associated parameters with increased semen concentration and peregrine falcons maintain semen production standards throughout the breeding season. Our data show that, in birds of prey, levels of egg fertilization following AI with fresh semen can be almost as successful as after natural mating.

Vanadium adversely affects sperm motility and capacitation status via protein kinase A activity and tyrosine phosphorylation

Vanadium is a chemical element that enters the atmosphere via anthropogenic pollution. Exposure to vanadium affects cancer development and can result in toxic effects. Multiple studies have focused on vanadium's detrimental effect on male reproduction using conventional sperm analysis techniques. This study focused on vanadium's effect on spermatozoa following capacitation at the molecular level, in order to provide a more detailed assessment of vanadium's reproductive toxicity. We observed a decrease in germ cell density and a structural collapse of the testicular organ in seminiferous tubules during vanadium treatment. In addition, various sperm motion parameters were significantly decreased regardless of capacitation status, including sperm motility, rapid sperm motility, and progressive sperm motility. Curvilinear velocity, straight-line velocity, average path velocity, beat cross frequency, and mean amplitude of head lateral displacement were also decreased after capacitation. Capacitation status was altered after capacitation. Vanadium dramatically enhanced protein kinase A (PKA) activity and tyrosine phosphorylation. Taken together, our results suggest that vanadium is detrimental to male fertility by negatively influencing sperm motility, motion kinematics, and capacitation status via abnormal PKA activity and tyrosine phosphorylation before and after capacitation.

Progressive sperm motility is associated with spontaneous pregnancy after varicocelectomy

Background: Varicocelectomy is performed on patients with clinical varicocele associated with abnormal sperm parameters. The goal of this procedure is to improve men’s sperm parameters and pregnancy rates of their partners. The objective of our study was to assess the factors that were associated with spontaneous pregnancy in female partners after varicocelectomy.Methods: A retrospective case-control study was conducted to review several factors that are associated with spontaneous pregnancy after varicocelectomy. The data were taken from medical records at Sanglah General Hospital and three private hospitals in Denpasar from January 2015 to June 2016. Case subjects (n=38) include varicocele patients with abnormal sperm parameters whose partner had a spontaneous pregnancy following varicocelectomy and a control group (n=38) whose partner did not have a spontaneous pregnancy following varicocelectomy.Results: Progressive sperm motility (≥37.5%) before varicocelectomy was 2.7 times more likely to result in a spontaneous pregnancy (odds ratio: 2.7; 95% confidence interval: 1.04–6.96; p=0.04). No statistical significance was found between age at varicocelectomy, grade of varicocele, body mass index, infertility duration, smoking habit, sperm concentration, normal sperm morphology before varicocelectomy, and spontaneous pregnancy.Conclusion: Progressive sperm motility before varicocelectomy is a significant factor for the occurrence of spontaneous pregnancy after varicocelectomy.

Quantitative assessment of heavy metal effects on sperm function using computer-aided sperm analysis and cytotoxicity assays

One known environmental risk factor impacting on human reproduction is heavy metal pollution. Although some metals (e.g., Cu, Se and Zn) have protective effects on the male reproductive system in low doses, heavy metals can accumulate to toxic levels and result in poor semen quality and decreased sperm function. We investigated the effect of CuSO₄ and CdCl₂ (10, 50, 100 and 250 µg/ml or 500 µg/ml) on human sperm motility and vitality by using computer-aided sperm analysis (CASA) and two cytotoxicity assays (WST-1 and XTT). Several sperm motility parameters were significantly reduced after 5 hr of exposure to the highest concentrations of CuSO₄ (250 µg/ml) and CdCl₂ (500 µg/ml). The WST-1 assay also revealed significantly lower absorbance values for 50, 100 and 250 µg/ml CuSO₄ and for 500 µg/ml CdCl₂ ; however, no significant effect was seen with XTT. The calculated average IC₅₀ value was 50.31±  4.34 µg/ml for CuSO₄ and 392.32  ±76.79 µg/ml for CdCl₂ . The effects of these metals were confirmed with MgCl₂ , a positive control. This study provides threshold concentrations for the harmful effect of CuSO₄ and CdCl₂ on human spermatozoa and recommends the use of WST-1 as vitality assay in future in vitro studies.

Uncertainty of measurement and clinical value of semen analysis: has standardisation through professional guidelines helped or hindered progress?

This article suggests that diagnostic semen analysis has no more clinical value today than it had 25-30 years ago, and both the confusion surrounding its evidence base (in terms of relationship with conception) and the low level of confidence in the clinical setting is attributable to an associated high level of 'uncertainty'. Consideration of the concept of measurement uncertainty is mandatory for medical laboratories applying for the ISO15189 standard. It is evident that the entire semen analysis process is prone to error every step from specimen collection to the reporting of results and serves to compound uncertainty associated with diagnosis or prognosis. Perceived adherence to published guidelines for the assessment of sperm concentration, motility and morphology does not guarantee a reliable and reproducible test result. Moreover, the high level of uncertainty associated with manual sperm motility and morphology can be attributed to subjectivity and lack a traceable standard. This article describes where and why uncertainty exists and suggests that semen analysis will continue to be of limited value until it is more adequately considered and addressed. Although professional guidelines for good practice have provided the foundations for testing procedures for many years, the risk in following rather prescriptive guidance to the letter is that unless they are based on an overwhelmingly firm evidence base, the quality of semen analysis will remain poor and the progress towards the development of more innovative methods for investigating male infertility will be slow.

Protective role of epigallocatechin-3-gallate on arsenic induced testicular toxicity in Swiss albino mice

Arsenic, often referred to as the king of poisons is carcinogenic in humans and animals. It affects multiorgan systems including reproduction. The present study was undertaken to explore the protective role of green tea compound, epigallocatechin-3-gallate (EGCG) on arsenic induced testicular toxicity in Swiss albino mice. Thirty two adult male mice were randomly assigned to four groups (n=8). Group I served as control without test chemical. The group II received arsenic (200ppm) through drinking water, group III received only EGCG (20mg/kgb.wt., intraperitoneally, alternate days) and group IV was administered arsenic+EGCG for 40days. Factorial experimental design was employed to assess the treatment effect. The EGCG restored arsenic induced decrements in epididymal sperm concentration, kinematic attributes (total motility, rapid, progressive motile, fast progressive, VSL, VAP, VCL, BCF, LIN, WOB, STR and Type A), structutal membrane integrity, functional membrane integrity and mitochondrial membrane potential. As evidenced by the histoarchitectural studies, the EGCG reversed the deleterious effects of arsenic on testicular malondialdehyde (p<0.05) levels, reduced glutathione, antioxidative enzymes and spermatogenesis. Overall, the results suggest that EGCG reduces the testicular oxidative stress induced by arsenic poisoning and thereby protect the reproductive system.

Genotoxicity evaluation of zinc oxide nanoparticles in Swiss mice after oral administration using chromosomal aberration, micronuclei, semen analysis, and RAPD profile

The expanded uses of zinc oxide nanoparticles (ZnO NPs) have grown rapidly in the field of nanotechnology. Thus, rising production of nanoparticles (NPs) increases the possible risks to the environment and occupationally exposed humans. Hence, it is indispensable to appraise the safety toxicity including genotoxicity for these NPs. In the present study, we have evaluated the genotoxic effect of ZnO NPs after oral administration to Swiss mice at dose levels of 300 and 2000 mg/kg body weight. These doses were administered for 2 days at 24 h apart. Chromosomal aberration (CA) and micronucleus tests were conducted following Organization for Economic Co-operation and Development guidelines. DNA damage was evaluated at 0, 24, 48, and 72 h posttreatment using a randomly amplified polymorphic DNA (RAPD) assay; additionally, semen analyses were also performed at 34.5 days post oral exposure. The reactive oxygen species (ROS), 8-oxo-2'-deoxyguanosine and CAs were increased ( p < 0.05) at the highest dosage (2000 mg/kg) of ZnO NPs compared to controls. Aberrant sperm morphology with reduced sperm count and motility were also present ( p < 0.05) in the high-dose group. Based on the RAPD assay, the genomic template stability within the high-dose group (<90%) was less than the controls (100%). The results suggested that ZnO NPs are mildly genotoxic in a dose-related manner and this toxicity were induced by generation of ROS.

Trends of male factor infertility, an important cause of infertility: A review of literature

Infertility and problems of impaired fecundity have been a concern through ages and is also a significant clinical problem today, which affects 8–12% of couples worldwide. Of all infertility cases, approximately 40–50% is due to “male factor” infertility and as many as 2% of all men will exhibit suboptimal sperm parameters. It may be one or a combination of low sperm concentration, poor sperm motility, or abnormal morphology. The rates of infertility in less industrialized nations are markedly higher and infectious diseases are responsible for a greater proportion of infertility. The present literature will help in knowing the trends of male factor infertility in developing nations like India and to find out in future, various factors that may be responsible for male infertility.

Dose- and Time-Dependent In Vitro Effects of Divalent and Trivalent Iron on the Activity of Bovine Spermatozoa

This in vitro study was designed to assess the impact of divalent (Fe(2+)) or trivalent (Fe(3+)) iron on the activity and oxidative balance of bovine spermatozoa at specific time intervals (0, 2, 8, 16, and 24 h) during an in vitro culture. Forty-five semen samples were collected from adult breeding bulls and diluted in physiological saline solution supplemented with different concentrations (0, 1, 5, 10, 50, 100, 200, 500, 1000 μmol/L) of FeCl2 or FeCl3. Spermatozoa motion parameters were assessed using the SpermVision™ computer-aided sperm analysis (CASA) system. Cell viability was examined with the metabolic activity 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the nitroblue-tetrazolium (NBT) test was applied to quantify the intracellular superoxide formation. Both divalent and trivalent iron exhibited a dose- and time-dependent impact on the spermatozoa physiology and oxidative balance. Concentrations ≥50 μmol/L FeCl2 and ≥100 μmol/L FeCl3 led to a significant decrease of spermatozoa motility (P < 0.05) and mitochondrial activity (P < 0.001 with respect to 200-1000 μmol/L FeCl2/FeCl3; P < 0.01 in case of 100 μmol/L FeCl2/FeCl3), accompanied by a significant superoxide overproduction (P < 0.001 in terms of 200-1000 μmol/L FeCl2 and 500-1000 μmol/L FeCl3; P < 0.01 with respect to 100 μmol/L FeCl2 and 100-200 μmol/L FeCl3). On the other hand, concentrations below 10 μmol/L FeCl2 and 50 μmol/L FeCl3 proved to stimulate the spermatozoa activity, as shown by a significant preservation of the motility and viability characteristics (P < 0.001 in case of the motility parameters; P < 0.01 with respect to the spermatozoa viability), alongside a significant decline of the superoxide generation (P < 0.05). In a direct comparison, divalent iron has been shown to be more toxic than trivalent iron. Results from this in vitro study show that high concentrations of both forms of iron are toxic, while their low concentrations may have spermatozoa activity-promoting properties. In vitro concentrations of divalent or trivalent iron that could be regarded as critical are 50 μmol/L FeCl2 and 100 μmol/L FeCl3 when iron ceases to be an essential micronutrient in order to become a toxic risk factor.

Mitochondrial PKA mediates sperm motility

BACKGROUND

Mitochondria are the major source of ATP to power sperm motility. Phosphorylation of mitochondrial proteins has been proposed as a major regulatory mechanism for mitochondrial bioenergetics.

METHODS

Sperm motility was measured by a computer-assisted analyzer, protein detection by western blotting, membrane potential by tetramethylrhodamine, cellular ATP by luciferase assay and localization of PKA by immuno-electron microscopy.

RESULTS

Bicarbonate is essential for the creation of mitochondrial electro-chemical gradient, ATP synthesis and sperm motility. Bicarbonate stimulates PKA-dependent phosphorylation of two 60kDa proteins identified as Tektin and glucose-6-phosphate isomerase. This phosphorylation was inhibited by respiration inhibition and phosphorylation could be restored by glucose in the presence of bicarbonate. However, this effect of glucose cannot be seen when the mitochondrial ATP/ADP exchanger was inhibited indicating that glycolytic-produced ATP is transported into the mitochondria and allows PKA-dependent protein phosphorylation inside the mitochondria.

CONCLUSIONS

Bicarbonate activates mitochondrial soluble adenylyl cyclase (sAC) which catalyzes cAMP production leading to the activation of mitochondrial PKA. Glucose can overcome the lack of ATP in the absence of bicarbonate but it cannot affect the mitochondrial sAC/PKA system, therefore the PKA-dependent phosphorylation of the 60kDa proteins does not occur in the absence of bicarbonate.

GENERAL SIGNIFICANCE

Production of CO2 in Krebs cycle, which is converted to bicarbonate is essential for sAC/PKA activation leading to mitochondrial membrane potential creation and ATP synthesis.

Basic diagnostics in andrology

Basic andrological diagnosis consists of taking the patient's medical history and the couple's history as well as performing a physical examination including genital ultrasound, spermiogram, and hormonal analysis. If needed, a testicular biopsy and genetic testing may also be performed. Recent studies have shown the effect of lifestyle factors on male fertility. Thus, the patient history and clinical/andrological examinations have been broadened to include information on metabolic disorders like obesity and diabetes mellitus. The biggest changes occurred with the publication of the fifth edition of the WHO laboratory manual in 2010 and the introduction of a section on semen analysis in the German Medical Association guidelines (RiliBÄK). The reference values for almost all spermiogram parameters were adapted in an evidence-based approach using worldwide prospective population studies. For central parameters such as sperm motility and morphology, the assessment criteria were changed. New independent markers such as sperm DNA fragmentation rate are now routinely used in clinical diagnosis. For German andrological laboratories, there are now mandatory quality assurance measures for semen analysis (in the German "Rili-BÄK" guidelines). These include duplicate testing of all standard semen parameters and inter-laboratory comparison at regular intervals.

The effect of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) on semen parameters in human males: a systematic review and meta-analysis

BACKGROUND

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is one of the risk factors of impaired male fertility potential. Studies have investigated the effect of CP/CPPS on several semen parameters but have shown inconsistent results. Hence, we performed a systematic literature review and meta-analysis to assess the association between CP/CPPS and basic semen parameters in adult men.

METHODS

Systematic literature searches were conducted with PubMed, EMBASE and the Cochrane Library up to August 2013 for case-control studies that involved the impact of CP/CPSS on semen parameters. Meta-analysis was performed with Review Manager and Stata software. Standard mean differences (SMD) of semen parameters were identified with 95% confidence intervals (95% CI) in a random effects model.

RESULTS

Twelve studies were identified, including 999 cases of CP/CPPS and 455 controls. Our results illustrated that the sperm concentration and the percentage of progressively motile sperm and morphologically normal sperm from patients with CP/CPPS were significantly lower than controls (SMD (95% CI) -14.12 (-21.69, -6.63), -5.94 (-8.63, -3.25) and -8.26 (-11.83, -4.66), respectively). However, semen volume in the CP/CPPS group was higher than in the control group (SMD (95% CI) 0.50 (0.11, 0.89)). There was no significant effect of CP/CPPS on the total sperm count, sperm total motility, and sperm vitality.

CONCLUSIONS

The present study illustrates that there was a significant negative effect of CP/CPPS on sperm concentration, sperm progressive motility, and normal sperm morphology. Further studies with larger sample sizes are needed to better illuminate the negative impact of CP/CPPS on semen parameters.

Manual methods for sperm motility assessment

Progressive motility is a vital functional characteristic of ejaculated human spermatozoa that governs their ability to penetrate into, and migrate through, both cervical mucus and the oocyte vestments, and ultimately fertilize the oocyte. A detailed protocol, based on traditional manual/visual methods, is provided for performing an accurate four-category differential count including the reliable identification of rapid progressive (grade "a") spermatozoa-the most biologically, and hence clinically, important subpopulation. Thorough prior training and the use of a microscope fitted with a heated stage are both essential requirements for achieving accuracy and an acceptable uncertainty of measurement of no more than ±10%.

Semen analysis and sperm function testing

Despite controversy regarding the clinical value of semen analysis, male fertility investigation still relies on a standardized analysis of the semen parameters. This is especially true for infertility clinics in both developing and developed countries. Other optional tests or sophisticated technologies have not been widely applied. The current review addresses important changes in the analysis of semen as described in the new World Health Organization (WHO) manual for semen analysis. The most important change in the manual is the use of evidence-based publications as references to determine cutoff values for normality. Apart from the above mentioned changes, the initial evaluation and handling methods remain, in most instances, the same as in previous editions. Furthermore, the review evaluates the importance of quality control in andrology with emphasis on the evaluation of sperm morphology. WHO sperm morphology training programmes for Sub-Saharan countries were initiated at Tygerberg Hospital in 1995. The external quality control programme has ensured that the majority of participants have maintained their morphological reading skills acquired during initial training. This review reports on current sperm functional tests, such as the induced acrosome reaction, and sperm-zona pellucida binding assays, as well as the impact of sperm quality in terms of DNA integrity, and the relationship of sperm function tests to sperm morphology.

Semen analysis and sperm function tests: How much to test?

Semen analysis as an integral part of infertility investigations is taken as a surrogate measure for male fecundity in clinical andrology, male fertility, and pregnancy risk assessments. Clearly, laboratory seminology is still very much in its infancy. In as much as the creation of a conventional semen profile will always represent the foundations of male fertility evaluation, the 5th edition of the World Health Organization (WHO) manual is a definitive statement on how such assessments should be carried out and how the quality should be controlled. A major advance in this new edition of the WHO manual, resolving the most salient critique of previous editions, is the development of the first well-defined reference ranges for semen analysis based on the analysis of over 1900 recent fathers. The methodology used in the assessment of the usual variables in semen analysis is described, as are many of the less common, but very valuable, sperm function tests. Sperm function testing is used to determine if the sperm have the biologic capacity to perform the tasks necessary to reach and fertilize ova and ultimately result in live births. A variety of tests are available to evaluate different aspects of these functions. To accurately use these functional assays, the clinician must understand what the tests measure, what the indications are for the assays, and how to interpret the results to direct further testing or patient management.

Semen quality in men from subfertile couples from the region of Łódź (Poland) according to the new reference values recommended by WHO 2010

The semen analysis is the main diagnostic tool for evaluating the male fertility potential. The standard semen analysis includes evaluation of the sperm concentration, motility, and their morphology. The most important question is whether the results from semen analysis may be accurate markers for male fertility. Therefore, we retrospectively studied sperm quality among men attending the infertility clinic due to reproductive problems consistent with the WHO manual from 1999, which were reassessed according to the manual from 2010. Semen results from 571 males from couples undergoing fertility investigation were analyzed. All subjects included in the study had no abnormalities during examination. In 64 samples (11.2%), a leukocyte count above 1 x 10⁶/ml was found and their semen volume (median 3.2 ml) was significantly lower in comparison with the group without leukocytes (3.6 ml; p <0.001). Normal semen parameters were found in 290 subjects (50.8%) according to the 1999 manual and in 362 men (63.4%) according to the 2010 manual. The normozoospermia group, according to the 2010 manual, had a significantly lower percentage of sperm with progressive motility, motile sperm concentration, and total number of motile sperm in comparison with the normozoospermia group according to the manual from 1999. It seems that routine semen analysis is not sufficient to estimate male fertility potential and some men with normal semen parameters may be subfertile. Further investigations are needed.

New WHO-reference limits-revolution or storm in a teapot?

Since release of the latest WHO manual with the new lower reference values of semen parameters, a lot of discussion has been raised about their usefulness and appropriateness for assessment of male fertility. As with the previous reference values the new limits do neither allow an andrological diagnosis based on nosological criteria nor clear-cut differentiation between fertility and sub-/infertility. Therefore, considering the fact that fertility is a continuum, the new lower reference limits should not be overestimated. Most probably, more sperm function tests, such as determination of DNA integrity, and-in the future-assessment of biomarkers, such as sperm proteomics will be included into andrological work-up, thus resulting in a more personalized approach of infertility management. On the other hand, the detailed instructions for standard and advanced semen analysis provided in the new manual are very much appreciated and should be adopted by each seriously working laboratory.