Bacterial infections of the genital tract are one of the most serious causes of infertility in males. In some human patients with poor semen quality, leukocytospermia has been observed. Because leukocytes express the bacterial-lipopolysaccharide (LPS) responsive Toll-like receptor (TLR) signaling cascade and secrete tumor necrosis factor-α, secreted cytokines comprise one, but probably not the only, class of factors that can impact sperm motility.
METHODS AND RESULTS
In this study, we documented that bacterial endotoxins, LPS and peptidoglycan, can be detected in human semen. Furthermore, the addition of endotoxins in the absence of leukocytes directly and significantly reduced the motility and increased the apoptotic rate of both human and mouse sperm and suppressed fertilization by mouse sperm both in vivo and in vitro. The well-known LPS receptor, TLR4, and peptidoglycan receptor, TLR2, were expressed in human and mouse sperm. In Tlr2/4−/− double-mutant mice, the negative effects of endotoxins on sperm functions were blocked, suggesting that the bacterial endotoxins mediated activation of TLR-dependent pathways in sperm leading to apoptosis.
Sperm can recognize bacterial endotoxins by TLRs present in their membranes. The activated TLRs reduce sperm motility, induce sperm apoptosis and significantly impair the potential for fertilization.
peptidoglycan; lipopolysaccharide; sperm motility; sperm apoptosis; Toll-like receptors
High level of semen reactive oxygen species is considered as an important factor in male infertility. Sesame has antioxidant properties, which could be effective on improvement of semen parameters. This study was designed to determine the effects of sesame on sperm quality.
Materials and Methods:
Twenty-five infertile men entered this clinical trial. They were treated with a 3-months course of taking 0.5 mg/kg sesame. The pre intervention sperm analysis (sperm count, motile sperm percentage and normal morphology sperm percentage) was compared with post treatment sperm analysis. Based on the post intervention seamen analysis, patients were advised to undergo either IVF or ICSI to assess their fertility status.
There was significant improvement in the sperm count (10.56 ± 5.25 vs. 22.71 ± 30.14 million per ml) and motility (15.32 ± 13.58 vs. 23.32 ± 20.61 percent) after treatment with sesame (P value: 0.04 and <0.0001 respectively), but there was no significant improvement in sperm morphology after the treatment (10.72 ± 6.66 vs. 13.20 ± 11.14 percent, P value: 0.10). Three patients (12%) underwent IUI, which resulted in 1 successful pregnancy. Two patients (8%) underwent ICSI, which was not successful; however 2 (8%) patients had spontaneous pregnancy. Fortunately, all pregnancies led to live birth. Except 1 case of diarrhea, no other major side effect was reported.
Sesame improved sperm count and motility, and can be prescribed as an effective and safe method for male factor infertility.
Male infertility; infertility; semen quality; sesame
This study investigated the effect of treatment with the proprietary standardized, water-soluble extract of the root of the Malaysian plant, Eurycoma longifolia Jack, which is thought to enhance male fertility with regard to higher semen volumes, sperm concentrations, the percentage of normal sperm morphology and sperm motility in male partners of sub-fertile couples with idiopathic infertility. A total of 350 patients were given 200 mg of the extract daily and follow-up semen analyses were performed every 3 months for 9 months. Of these 350 patients, 75 patients completed one full cycle of 3 months. Follow-up semen analyses in these patients showed significant improvement in all semen parameters. The proprietary extract of Eurycoma longifolia Jack significantly improved the sperm quality in these patients, allowing for 11 (14.7%) spontaneous pregnancies.
male infertility; medicinal herbs; semen
There is clinical evidence to show that sperm DNA damage could be a marker of sperm quality and extensive data exist on the relationship between DNA damage and male fertility status. Detecting such damage in sperm could provide new elements besides semen parameters in diagnosing male infertility. We aimed to assess sperm DNA fragmentation and oxidation and to study the association between these two markers, routine semen parameters and malondialdehyde formation.
Semen samples from 55 men attending the Histology-Embryology Laboratory of Sfax Faculty of Medicine, Tunisia, for semen investigations were analysed for sperm DNA fragmentation and oxidation using flow cytometry. The Sperm was also assessed spectrophotometrically for malondialdehyde formation.
Within the studied group, 21 patients were nonasthenozoospermic (sperm motility ≥ 50%) and 34 patients were considered asthenozoospermic (sperm motility < 50%). A positive correlation was found between sperm DNA fragmentation and oxidation (p = 0.01; r = 0.33). We also found a negative correlation between sperm DNA fragmentation and some sperm parameters: total motility (p = 0.001; r = -0.43), rapid progressive motility (type a motility) (p = 0.04; r = -0.27), slow progressive motility (type b motility) (p = 0.03; r = -0.28), and vitality (p < 0.001; r = -0.65). Sperm DNA fragmentation was positively correlated with coiled tail (p = 0.01; r = 0.34). The two parameters that were found to be correlated with oxidative DNA damage were leucocytes concentrations (p = 0.01; r = 0.38) and broken neck (p = 0.02; r = 0.29). Sperm MDA levels were negatively correlated with sperm concentration (p < 0.001; r = -0.57), total motility (p = 0.01; r = -0.35) and type a motility (p = 0.03; r = -0.32); but not correlated with DNA fragmentation and DNA oxidation.
Our results support the evidence that oxidative stress plays a key role in inducing DNA damage; but nuclear alterations and malondialdehyde don't seem to be synchronous.
The standard semen analysis is the first line and the most popular laboratory test in the diagnosis of male fertility. It evaluates sperm concentration, motility, morphology and their vitality. However, it is well-known that normal results of semen analysis can not exclude men from the causes of couples′ infertility. One of the most important parameters of sperm in its fertilizing potential is “Sperm chromatin integrity” that has direct positive correlation with Assisted Reproductive Techniques (ART) outcomes including; fertilization rate, embryo quality, pregnancy and successful delivery rate. It seems that sperm DNA chromatin integrity provides better diagnostic and prognostic approaches than standard semen parameters. For these reasons under-standing the sperm chromatin structure, etiology of sperm chromatin abnormality, identification factors that disturbs sperm chromatin integrity and the mechanism of their action can help in recognizing the causes of couples′ infertility. Various methods of its evaluation, its importance in male fertility, clinical relevance in the outcomes of ART and application of laboratory and medical protocols to improve this integrity have valuable position in diagnosis and treatment of male infertility. There has recently been interest in the subject and its application in the field of andrology. Therefore, with regard to the above mentioned importance of sperm chromatin integrity, this review article describes details of the useful information pertaining to sperm DNA damage including the origins, assessments, etiologies, clinical aspects, and prevention of it.
Chromatin; DNA Damage; Fertility; Male; Spermatozoa
We previously reported reduced sperm concentration and motility in fertile men in a U.S. agrarian area (Columbia, MO) relative to men from U.S. urban centers (Minneapolis, MN; Los Angeles, CA; New York, NY). In the present study we address the hypothesis that pesticides currently used in agriculture in the Midwest contributed to these differences in semen quality. We selected men in whom all semen parameters (concentration, percentage sperm with normal morphology, and percentage motile sperm) were low (cases) and men in whom all semen parameters were within normal limits (controls) within Missouri and Minnesota (sample sizes of 50 and 36, respectively) and measured metabolites of eight current-use pesticides in urine samples provided at the time of semen collection. All pesticide analyses were conducted blind with respect to center and case-control status. Pesticide metabolite levels were elevated in Missouri cases, compared with controls, for the herbicides alachlor and atrazine and for the insecticide diazinon [2-isopropoxy-4-methyl-pyrimidinol (IMPY)]; for Wilcoxon rank test, p = 0.0007, 0.012, and 0.0004 for alachlor, atrazine, and IMPY, respectively. Men from Missouri with high levels of alachlor or IMPY were significantly more likely to be cases than were men with low levels [odds ratios (ORs) = 30.0 and 16.7 for alachlor and IMPY, respectively], as were men with atrazine levels higher than the limit of detection (OR = 11.3). The herbicides 2,4-D (2,4-dichlorophenoxyacetic acid) and metolachlor were also associated with poor semen quality in some analyses, whereas acetochlor levels were lower in cases than in controls (p = 0.04). No significant associations were seen for any pesticides within Minnesota, where levels of agricultural pesticides were low, or for the insect repellent DEET (N,N-diethyl-m-toluamide) or the malathion metabolite malathion dicarboxylic acid. These associations between current-use pesticides and reduced semen quality suggest that agricultural chemicals may have contributed to the reduction in semen quality in fertile men from mid-Missouri we reported previously.
Purpose:The aim of this study was to evaluate the possible correlation of low-dose heparin-induced decondensation of sperm chromatin with sperm concentration, motility, morphology, membrane hypoosmotic response, ejaculate volume, and the ability of sperm to penetrate zona-free hamster oocytes.
Methods:Twenty-two donors of known fertility and 105 patients undergoing evaluation at an andrology laboratory were evaluated by standard World Health Organization semen analysis techniques and a modified sperm penetration assay (SPA). An aliquot was also incubated for 60 min and Ham's F10 medium containing 50 USP/ml heparin. The percentage of sperm undergoing chromatin decondensation was evaluated and correlated to SPA rates and semen quality parameters.
Results:No significant correlation was observed between semen parameters and decondensation rates. A nonsignificant (P = 0.11) inverse correlation (P = −0.21) wax observed between SPA rates and chromatin decondensation. Significant (P < 0.001) differences were observed in the decondensation rate of donors (3.7 ± 0.6), patients with normal SPA rates (7.8 ± 1.5), and patients with decreased SPA rates (21.7 ± 1.8). The decondensation rates were significantly different (P < 0.01) between patients with a normal SPA rate and patients with a decreased SPA rate.
Conclusions:These data indicate a significant inverse relationship between the SPA rate, which has previously been shown to correlate highly with fertilization ability, and heparin-induced sperm chromatin decondensation.
protamine; chromatin; decondensation; capacitation
A study was conducted to determine the proportion of yearling beef bulls that have mature spermiograms at 11 to 15 months of age, and to evaluate the relationship between semen quality traits, age, and scrotal circumference. Semen samples and data on sperm motility and scrotal circumference measurements were obtained from 1641 bulls of 14 breeds. Criteria for a satisfactory spermiogram included sperm concentration > or = 400 x 10(6)/mL, > or = 60% progressively motile sperm, and > or = 70% morphologically normal sperm. The mean scrotal circumference measurements for all bulls combined were 33.4, 34.4, 35.2, 35.8, and 35.3 cm at 11, 12, 13, 14, and 15 months of age, respectively. The percentage of bulls with matures spermiograms at 11, 12, 13, 14, and 15 months of age were 20%, 30%, 51%, 52%, and 61%, respectively. There was a high positive correlation (r = 0.9) between the number of bulls with > or = 70% normal sperm and scrotal circumference measurement. The main types of morphologic defects observed in immature bulls were proximal droplets and midpiece defects.
To study the effect of addition of zinc to human semen sample prior to cryopreservation on post-thaw sperm quality and function.
Semen samples were collected from men attending university infertility clinic for semen analysis (n=109). Liquefied semen samples were cryopreserved in glycerol-egg yolk- citrate medium with or without the prior addition of zinc (100 μM) and stored in liquid nitrogen. After 10 days, the semen samples were thawed to assess the outcome. Sperm motility, DNA integrity, mitochondrial potential and the ability of spermatozoa to undergo capacitation and acrosome reaction was assessed in post-thaw samples.
Semen samples cryopreserved after addition of zinc had a significantly higher percentage of sperm with intact DNA (p<0.001), mitochondrial function (p<0.001) and progressive motility (p<0.01) compared to the semen samples cryopreserved without zinc supplementation. Apart from this, ability to undergo capacitation and acrosome reaction in vitro was significantly higher in semen samples cryopreserved with zinc (p<0.0001 and p<0.001 respectively).
Addition of zinc to semen samples prior to cryopreservation helps in preventing the freeze-thaw-induced sperm DNA damage and loss of sperm function.
Zinc; Semen cryopreservation; Sperm DNA integrity; Mitochondrial potential; Capacitation; Acrosome reaction
Recent observations in in vitro and in vivo models suggest that arsenic (As) is an endocrine disruptor at environmentally-relevant levels. When exposed to As, male rats and mice show steroidogenic dysfunction that can lead to infertility. However, the possible effects of As on human male semen quality remain obscure.
We monitored the profile of As species in the urine of a reproductive-age human cohort and assessed its association with semen quality. Men (n = 96) were recruited in an infertility clinic from July 2009 to August 2010 in the Affiliated Hospital of Chongqing Institute for Population and Family Planning. Five urinary As species were analyzed by high-performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). Clinical information on the semen volume, sperm concentration and motility was employed to catalogue and evaluate semen quality according to WHO guidelines. As species concentrations in addition to other continuous variables were dichotomized by the medians and modelled as categorical variables in order to explore using the binary logistic regression possible associations between As exposure and semen quality.
Urinary concentrations (geometric mean ± SD, μg g-1 creatinine) of different As species were 7.49 (±24.8) for AsB, 20.9 (±13.7) for DMA, 2.77 (±3.33) for MMA, and 4.03 (±3.67) for Asi (AsiIII and AsiV). DMA concentrations above the median were significantly associated with below-reference sperm concentrations (P =0.02) after adjusting for age, body mass index (BMI), abstinence, smoking and drinking habits. In addition, smoking was positively associated with MMA.
Reduced parameters in human semen quality are positively associated with As exposure in a reproductive-age Chinese cohort.
Arsenic; China; Cross-sectional study; Human reproduction; Semen quality
The effectiveness of varicocelectomy in restoration of fertility and improvement of semen parameters is still controversial. The purpose of this study was to determine the effect of age on semen parameters following varicocelectomy in a group of infertile men.
Improvements in sperm count, morphology, and motility were studied in 67 infertile patients 4–10 months after varicocelectomy.
The mean age of the patients was 30.48 ± 7.49 years. Significant improvements in total sperm count, percentage normal morphology, and motility were noted in all age groups (P < 0.05). Patients aged <25 years demonstrated the greatest increase in sperm counts, normal morphology, and motility following varicocelectomy. There was a significant negative correlation between age and sperm count, sperm morphology, and sperm motility (P < 0.05).
The effect of age on improvement in sperm parameters after varicocelectomy is inconsistent with some reports in the literature, and could be attributable to the duration of infertility prior to surgery; in the long term, varicoceles are known to have deleterious effects on testis biology.
sperm count; sperm morphology; sperm motility; varicocele
Purpose: To determine whether the quality of semen has changed over time in men screened for semen donation.
Methods: All 448 men volunteering for semen donation between 1983 and 2001 at a donor insemination clinic in Sydney, Australia, were included in this longitudinal single centre observational analysis of semen parameters. There was no selection for fertility or marital status but all volunteers had to be aged between 18 and 40 years.
Results: There was no change in the total sperm count during the study period (r = 0.065, P = 0.17) using a linear regression model. The ejaculate volume did not change (r = 0.002, P = 0.97), while an increase in sperm motility was seen (Spearman R = 0.194, P < 0.001).
Conclusion: The semen quality of volunteers for sperm donation presenting to our donor insemination clinic in Sydney between 1983 and 2001 has not declined.
Semen donation; semen quality; sperm count; sperm motility
5.3 million American couples of reproductive age (9%) are affected by infertility, among which male factors account for up to 50% of cases, which necessitates the identification of parameters defining sperm quality, including sperm count and motility. In vitro fertilization (IVF) with or without intra cytoplasmic sperm injection (ICSI) has become the most widely used assisted reproductive technology (ART) in modern clinical practice to overcome male infertility challenges. One of the obstacles of IVF and ICSI lies in identifying and isolating the most motile and presumably healthiest sperm from semen samples that have low sperm counts (oligozoospermia) and/or low sperm motility (oligospermaesthenia). Microfluidic systems have shown potential to sort sperm with flow systems. However, the small field of view (FOV) of conventional microscopes commonly used to image sperm motion presents challenges in tracking a large number of sperm cells simultaneously. To address this challenge, we have integrated a lensless charge-coupled device (CCD) with a microfluidic chip to enable wide FOV and automatic recording as the sperm move inside a microfluidic channel. The integrated system enables the sorting and tracking of a population of sperm that have been placed in a microfluidic channel. This channel can be monitored in both horizontal and vertical configuration similar to a swim-up column method used clinically. Sperm motilities can be quantified by tracing the shadow paths for individual sperm. Moreover, as the sperm are sorted by swimming from the inlet towards the outlet of a microfluidic channel, motile sperm that reach the outlet can be extracted from the channel at the end of the process. This technology can lead to methods to evaluate each sperm individually in terms of motility response in a wide field of view, which could prove especially useful, when working with oligozoospermic or oligospermaesthenic samples, in which the most motile sperm need to be isolated from a pool of small number of sperm.
Investigate in what extent sperm transcriptome of infertile men is different from that of fertile individuals.
Semen samples were collected for determination of sperm parameters as well as for RNA isolation. Gene expression profile was investigated in spermatozoa of 8 infertile and 3 fertile men by microarray analysis using the Affymetrix Chip HG-U133 Plus 2.0.
We observed up to 33-fold reduction expression of genes involved in spermatogenesis and sperm motility. Furthermore, there is an important decrease in expression of genes involved in DNA repair as well as oxidative stress regulation. In this study, we also show a striking drop in expression of histone modification genes.
We found that transcription profile in germ cells of men with idiopathic infertility is different from that of fertile individuals. Interestingly, about 15% of the regulated genes (Eddy Rev Reprod 4:23–30, 1999) play a role in spermatogenesis.
Sperm; Transcripts; Oligoasthenoteratozoospermia; Male infertility; Microarray
Most of the general population is exposed to carbaryl and other contemporary-use insecticides at low levels. Studies of laboratory animals, in addition to limited human data, show an association between carbaryl exposure and decreased semen quality. In the present study we explored whether environmental exposures to 1-naphthol (1N), a metabolite of carbaryl and naphthalene, and 3,5,6-trichloro-2-pyridinol (TCPY), a metabolite of chlorpyrifos and chlorpyrifos-methyl, are associated with decreased semen quality in humans. Subjects (n = 272) were recruited through a Massachusetts infertility clinic. Individual exposures were measured as spot urinary concentrations of 1N and TCPY adjusted using specific gravity. Semen quality was assessed as sperm concentration, percent motile sperm, and percent sperm with normal morphology, along with sperm motion parameters (straight-line velocity, curvilinear velocity, and linearity). Median TCPY and 1N concentrations were 3.22 and 3.19 μg/L, respectively. For increasing 1N tertiles, adjusted odds ratios (ORs) were significantly elevated for below-reference sperm concentration (OR for low, medium, and high tertiles = 1.0, 4.2, 4.2, respectively; p-value for trend = 0.01) and percent motile sperm (1.0, 2.5, 2.4; p-value for trend = 0.01). The sperm motion parameter most strongly associated with 1N was straight-line velocity. There were suggestive, borderline-significant associations for TCPY with sperm concentration and motility, whereas sperm morphology was weakly and nonsignificantly associated with both TCPY and 1N. The observed associations between altered semen quality and 1N are consistent with previous studies of carbaryl exposure, although suggestive associations with TCPY are difficult to interpret because human and animal data are currently limited.
biological markers; environment; human; pesticides; semen
Although the motile sperm organelle morphology examination (MSOME) was developed only as a selection criterion, its application as a method for classifying sperm morphology may represent an improvement in evaluation of semen quality, with potential clinical repercussions. The present study aimed to evaluate individual variations in the motile sperm organelle morphology examination (MSOME) analysis after a time interval.
Two semen samples were obtained from 240 men from an unselected group of couples undergoing infertility investigation and treatment. Mean time interval between the two semen evaluations was 119 +/- 102 days. No clinical or surgical treatment was realized between the two observations. Spermatozoa were analyzed at greater than or equal to 8400× magnification by inverted microscope equipped with DIC/Nomarski differential interference contrast optics. At least 200 motile spermatozoa per semen sample were evaluated and percentages of normal spermatozoa and spermatozoa with large nuclear vacuoles (LNV/one or more vacuoles occupying >50% of the sperm nuclear area) were determined. A spermatozoon was classified as morphologically normal when it exhibited a normal nucleus (smooth, symmetric and oval nucleus, width 3.28 +/- 0.20 μm, length 4.75 +/- 0.20 μm/absence of vacuoles occupying >4% of nuclear area) as well as acrosome, post-acrosomal lamina, neck and tail, besides not presenting cytoplasm around the head. One examiner, blinded to subject identity, performed the entire study.
Mean percentages of morphologically normal and LNV spermatozoa were identical in the two MSOME analyses (1.6 +/- 2.2% vs. 1.6 +/- 2.1% P = 0.83 and 25.2 +/- 19.2% vs. 26.1 +/- 19.0% P = 0.31, respectively). Regression analysis between the two samples revealed significant positive correlation for morphologically normal and for LNV spermatozoa (r = 0.57 95% CI:0.47-0.65 P < 0.0001 and r = 0.50 95% CI:0.38-0.58 P < 0.0001, respectively).
The significant positive correlation and absence of differences between two sperm samples evaluated after a time interval with respect to normal morphology and LNV spermatozoa indicated that MSOME seems reliable (at least for these two specific sperm forms) for analyzing semen. The present result supports the future use of MSOME as a routine method for semen analysis.
Cryopreservation is associated with the production of reactive oxygen species, which leads to lipid peroxidation of the sperm membrane and consequently a reduction in sperm motility and decreased fertility potential. The aim of this study was to determine the optimal concentration of L-cysteine needed for cryopreservation of boar semen. Twelve boars provided semen of proven motility and morphology for this study. The semen was divided into four portions in which the lactose-egg yolk (LEY) extender used to resuspend the centrifuged sperm pellet was supplemented with various concentrations of L-cysteine to reach 0 mmol L−1 (group I, control), 5 mmol L−1 (group II), 10 mmol L−1 (group III) and 15 mmol L−1 (group IV). Semen suspensions were loaded in straws (0.5 mL) and placed in a controlled-rate freezer. After cryopreservation, frozen semen samples were thawed and investigated for progressive motility, viability using SYBR-14/EthD-1 staining and acrosome integrity using FITC-PNA/EthD-1 staining. There was a significantly higher (P < 0.01) percentage of progressive motility, viability and acrosomal integrity in two L-cysteine-supplemented groups (group II and group III) compared with the control. There was a biphasic effect of L-cysteine, with the highest percentage of progressive motility, viability and acrosomal integrity in group III. In conclusion, 5 or 10 mmol L−1 was the optimum concentration of L-cysteine to be added to the LEY extender for improving the quality of frozen–thawed boar semen.
antioxidant; boar semen; cryopreservation; L-cysteine
Current data regarding infertility suggests that male factor contributes up to 30% of the total cases of infertility. Semen analysis reveals the presence of spermatozoa as well as a number of non-sperm cells, presently being mentioned in routine semen report as “round cells” without further differentiating them into leucocytes or immature germ cells.
The aim of this work was to study a simple, cost-effective, and convenient method for differentiating the round cells in semen into immature germ cells and leucocytes and correlating them with total sperm counts and motility.
Materials and Methods:
Semen samples from 120 males, who had come for investigation for infertility, were collected, semen parameters recorded, and stained smears studied for different round cells. Statistical analysis of the data was done to correlate total sperm counts and sperm motility with the occurrence of immature germ cells and leucocytes. The average shedding of immature germ cells in different groups with normal and low sperm counts was compared. The clinical significance of “round cells” in semen and their differentiation into leucocytes and immature germ cells are discussed.
Round cells in semen can be differentiated into immature germ cells and leucocytes using simple staining methods. The differential counts mentioned in a semen report give valuable and clinically relevant information. In this study, we observed a negative correlation between total count and immature germ cells, as well as sperm motility and shedding of immature germ cells. The latter was statistically significant with a P value 0.000.
Immature germ cells; round cells; semen; total sperm count
Infertile men have higher levels of semen reactive oxygen species (ROS) than do fertile men. High levels of semen ROS can cause sperm dysfunction, sperm DNA damage and reduced male reproductive potential. This observation has led clinicians to treat infertile men with antioxidant supplements. The purpose of this article is to discuss the rationale for antioxidant therapy in infertile men and to evaluate the data on the efficacy of dietary and in vitro antioxidant preparations on sperm function and DNA damage. To date, most clinical studies suggest that dietary antioxidant supplements are beneficial in terms of improving sperm function and DNA integrity. However, the exact mechanism of action of dietary antioxidants and the optimal dietary supplement have not been established. Moreover, most of the clinical studies are small and few have evaluated pregnancy rates. A beneficial effect of in vitro antioxidant supplements in protecting spermatozoa from exogenous oxidants has been demonstrated in most studies; however, the effect of these antioxidants in protecting sperm from endogenous ROS, gentle sperm processing and cryopreservation has not been established conclusively.
antioxidant; male infertility; oxidative stress; sperm DNA fragmentation; vitamins
Neurogenic reproductive dysfunction in men with spinal cord injury (SCI) is common and the result of a combination of impotence, ejaculatory failure, and abnormal semen characteristics. It is well established that the semen quality of men with SCI is poor and that changes are seen as early as 2 weeks after injury. The distinguishing characters of poor quality are abnormal sperm motility and viability. In the majority of the men with SCI, the sperm count is not abnormal. We elaborate on the effects of the SCI on semen parameters that may contribute to poor motility and poor viability.
PubMed and MEDLINE databases were searched using the following key words: spinal cord injuries, fertility, sexual dysfunction, and spermatogenesis. All literature was reviewed by the team of authors according to the various stages of sperm development and transport in the male reproductive cycle.
The cause of asthenozoospermia appears to be multifactorial.
Current literature does not support the preeminence of a single factor relating to neurogenic reproductive dysfunction in men with SCI. After SCI, there is ample evidence of disturbance of sperm production, maturation and storage, and transport due to an abnormal neuroendocrine milieu. Semen quality seems to be primarily affected by changes to the seminal plasma constituents, type of bladder management, and the neurogenic impairment to the ejaculatory function. Further focused and structured studies are required.
Spinal cord injuries; Infertility, male; Semen quality; Reproductive medicine; Paraplegia; Tetraplegia; Electroejaculation; Vibroejaculation
To compare the efficiency of routine sperm selection method with HA-selection procedure for fertilization rate, embryo development, implantation and pregnancy rates as well as evaluating the relationship between HA-binding ability with sperm protamine deficiency and DNA fragmentation.
Semen samples were obtained from the 50 couples undergoing ICSI. The percentage of fertilization rate, cleavage and quality of embryos compared between two procedures (routine sperm selection and HA-binding selection). The semen samples were assessed for DNA fragmentation and protamine deficiency by sperm chromatin dispersion (SCD) test and Chromomycin A3 (CMA3) staining, respectively.
A significant inverse correlation was observed between percentage of HA binding with protamine deficiency, DNA fragmentation and abnormal sperm morphology (P < 0.05). Furthermore, in current study, oocytes inseminated by HA sperm selection procedure had significantly higher fertilization rate (P < 0.05). While the pregnancy and implantation rates were insignificantly increased.
The results suggest that normal sperm have higher chance to bind HA and therefore, HA sperm selection procedure may select sperm with normal protamine content and low DNA fragmentation, but to confirm the effect of HA sperm selection on the ICSI outcome requires further studies.
Sperm selection; HA-binding; Protamine deficiency; DNA fragmentation; ICSI
To investigate the effects of male aging on semen quality, DNA fragmentation and chromosomal abnormalities in the spermatozoa of infertile patients and fertile men.
Semen samples of 140 infertile patients (24–76 years) and 50 men with proven fertility (25–65 years) were analyzed according to WHO guidelines. DNA fragmentation was detected by TUNEL assay, while aneuploidy was assessed by FISH.
In the patient group, semen volume and vitality of spermatozoa decreased significantly with age, while sperm concentration showed a statistically significant increase with age. DNA fragmentation as well as disomy of sex chromosomes and disomy 8 did not show a statistically significant change with age. However, the diploidy rate was significantly increased with patient’s age. In the control group, conventional semen parameters as well as DNA fragmentation and chromosomal abnormalities did not show a statistically significant with age.
Increased age in infertile men is associated with an increase in sperm concentration and diploidy, as well as a decline in semen volume and sperm vitality. However motility, morphology and DNA fragmentation are not affected by male age.
Aneuploidy; DNA fragmentation; Male infertility; Paternal age; Semen parameters
During spermatogenesis, sperm chromatin undergoes structural changes and results in a high condensation. This nuclear compaction would be useful as a predictor of sperm fertilization capacity and pregnancy outcome. We purpose to evaluate firstly the relationship among chromatin maturity assessed by aniline blue staining (AB) and the semen parameters in infertile men. Secondly, we analyzed whether the sperm gradient density centrifugation is effective to select mature spermatozoa. Fifty-one ejaculates were investigated by semen analysis and stained for chromatin condensation with AB to distinguish between unstained mature sperm and stained immature sperm. AB was applied also on 12 ejaculates which proceeded by density gradient centrifugation to compare the rates of immature sperm before and after selection. Neat semen were divided into two groups: G1 (n = 31): immature sperm <20% and G2 (n = 20): immature sperm ≥20%. No significant differences were detected in sperm concentration, motility, and normal morphology between G1 and G2. However, the rates of some morphology abnormalities were higher in G2: head abnormalities (P = 0.01) and microcephalic sperm (P = 0.02). We founded significant correlation between sperm immaturity and acrosome abnormalities (r = 0.292; P = 0.03). Sperm selection has significantly reduced the rates of immature sperm. A better understanding of chromatin structure and its impact on the sperm potential is needed to explore male infertility.
Sperm that bypass natural apoptosis and the ubiquitin-proteasome system may find their way into semen. In order to avoid the insemination of such sperm during an intracytoplasmic sperm injection (ICSI) treatment, novel sperm selection procedures such as the Zeta procedure have been implemented. Therefore, the aim of this study was to evaluate extent of ubiquitination and external phosphatidylserine (EPS) in sperm populations selected by combines density gradient centrifugation (DGC) and Zeta electric potential in comparison to DGC and neat semen samples.
Semen samples were collected from 51 infertile men and divided into control, DGC and DGC-Zeta groups. Semen analysis was carried out according to World Health Organization criteria. The percentages of protamine deficiency, DNA fragmentation, EPS and ubiquitinated sperm were assessed by chromomycin A3 (CMA3), TUNEL, Annexin V, and immunostaining, respectively.
Sperm selected by the DGC-Zeta procedure presented a lower percentage of sperm with protamine deficiency, abnormal morphology and DNA fragmentation while the percentage of annexin V and ubiquitin-positive sperm increased.
The results of this study reveal that, DGC-Zeta improves the quality of the selected spermatozoa for ICSI and increases ubiquitination and EPS rates. We propose these alterations are part of the normal physiological process of capacitation.
Zeta method; Density gradient centrifugation; DNA damage; Capacitation; Annexin V; Ubiquitination
Idiopathic male infertility may be due to exposure to environmental toxicants that alter spermatogenesis or sperm function. We studied the relationship between air pollutant levels and semen quality over a 2-year period in Los Angeles, California, by analyzing repeated semen samples collected by sperm donors. Semen analysis data derived from 5,134 semen samples from a sperm donor bank were correlated with air pollutant levels (ozone, nitrogen dioxide, carbon monoxide, and particulate matter < 10 μm in aerodynamic diameter) measured 0–9, 10–14, and 70–90 days before semen collection dates in Los Angeles between January 1996 and December 1998. A linear mixed-effects model was used to model average sperm concentration and total motile sperm count for the donation from each subject. Changes were analyzed in relationship to biologically relevant time points during spermatogenesis, 0–9, 10–14, and 70–90 days before the day of semen collection. We estimated temperature and seasonality effects after adjusting for a base model, which included donor’s date of birth and age at donation. Forty-eight donors from Los Angeles were included as subjects. Donors were included if they collected repeated semen samples over a 12-month period between January 1996 and December 1998. There was a significant negative correlation between ozone levels at 0–9, 10–14, and 70–90 days before donation and average sperm concentration, which was maintained after correction for donor’s birth date, age at donation, temperature, and seasonality (p < 0.01). No other pollutant measures were significantly associated with sperm quality outcomes. Exposure to ambient ozone levels adversely affects semen quality.
air pollution; epididymis; male infertility; ozone; semen analysis; sperm concentration; total motile sperm count