BACKGROUND: Hafnium alloys are employed in medical applications due to their biocompatibility and high corrosion resistance. These alloys have demonstrated osteogenic and antimicrobial activities in surgical implants and have been utilized in the treatment of sarcoma. Additionally, a sensor based on hafnium nanoparticles has been reported for the detection of coronavirus disease 2019. Despite the increasing usage of hafnium, a literature review reveals no studies examining its effects on sperm in both human and animal species.
METHODS: Semen samples were analyzed according to the 2010 World Health Organization (WHO) criteria, and 20 normospermic specimens were included in the study. Three groups were formed: control, hafnium chloride 2 mg/mL, and 4 mg/mL. Motility and viability were assessed in all groups at the 20th and 40th minutes.
RESULTS: The decrease in viable sperm count was found to be significant in the 2 mg/ml HfCl4 group (difference: 12.73 ± 0.8, p<0.001) and the 4 mg/ml HfCl4 group (difference: 41.72 ± 1.34, p<0.001) compared to the control group. A time-dependent decrease in sperm viability was significant across all groups (difference: 8.93 ± 0.59, p<0.001). The decrease in viable sperm count in the 4 mg/ml HfCl4 group was significant when compared to the 2 mg/ml HfCl4 group (difference: 29 ± 1.27, p<0.001). The decrease in total motile sperm count was observed in both the 2 mg/ml HfCl4 group (difference: 12.80 ± 1.30, p<0.001) and the 4 mg/ml HfCl4 group (difference: 35.63 ± 1.12, p<0.001) compared to the control group. Additionally, the decrease in total motile sperm count in the 4 mg/ml HfCl4 group was significant compared to the 2 mg/ml HfCl4 group (difference: 22.80 ± 1.60, p<0.001). A time-dependent decrease in total motile sperm count was also significant (difference: 6.03 ± 0.49, p<0.001).
CONCLUSIONS: The study determined that hafnium chloride negatively affects sperm motility and viability in vitro. These effects may be due to the presence of an acidic environment. It has been demonstrated that instruments containing this element may pose a potential risk.

The effect of metallic elements on semen quality remains controversial, with limited evidence on the effects of metal mixtures. We conducted a study involving 338 participants from multiple centers in Eastern China, measuring 17 urinary metals and semen quality parameters. Our analysis used various statistical models, including multivariate logistic and linear regression, Bayesian Kernel Machine Regression, and weighted quantile sum models, to examine the associations between metal levels and semen quality. Logistic regression showed that higher urinary lead was associated with increased risk of abnormal sperm concentration (OR = 1.86, p = 0.021), arsenic to higher abnormal progressive motility risk (OR = 1.49, p = 0.027), and antimony to greater abnormal total motility risk (OR = 1.37, p = 0.018). Conversely, tin was negatively correlated with the risk of abnormal progressive motility (OR = 0.76, p = 0.012) and total motility (OR = 0.74, p = 0.003), respectively. Moreover, the linear models showed an inverse association between barium and sperm count, even after adjusting for other metals (β = - 0.32, p < 0.001). Additionally, the WQS models showed that the metal mixture may increase the risk of abnormal total motility (βWQS = 0.55, p = 0.046). In conclusion, semen quality may be adversely affected by exposure to metals such as arsenic, barium, lead, and antimony. The combined effect of the metal mixture appears to be particularly impaired total motility.

The incidence of male infertility (MI) is rising annually. However, the lifestyle and occupational exposure factors contributing to MI remain incompletely understood. This study explored the effects of self-reported lifestyle and occupational exposure factors on semen quality. Among 1060 subjects invited to participate, 826 were eligible. The participants\' general characteristics, lifestyle, and occupational exposure factors were collected immediately before or after semen evaluation through an online questionnaire. Initially, univariate analysis was used to investigate the relationship between the abovementioned factors and semen quality. The results indicated significant associations between low semen quality and various factors, including age, BMI, infertility type and duration, abstinence time, semen and sperm parameters, smoking, alcohol consumption, irregular sleep habits, and frequent exposure to high temperatures and chemicals at work (p < 0.05). Then, multivariate analysis was conducted to identify factors independently associated with low semen quality. Adjustment for relevant confounders was achieved by including factors with a p-value < 0.25 from univariate analyses as covariates in the binomial and ordered logistic regression models. The results suggested that alcohol consumption was a positive factor for sperm concentration (odds ratio [OR] = 0.60; 95% confidence interval [CI] = 0.36-0.99; p = 0.045). The groups with a BMI ≥ 24 and <28 kg/m2 showed a significant decrease in sperm progressive motility when compared to the reference group (BMI < 24 kg/m2) (OR = 0.63; 95% CI = 0.46-0.87, p = 0.005). In addition, the groups that drank green tea <1 time/week (OR = 1.52, 95% CI = 1.05-2.2) and 1-4 times/week (OR = 1.61, 95% CI = 1.02-2.54) exhibited significantly increased sperm DFI values compared with the group that drank green tea 5-7 times/week. In conclusion, these findings underscore the importance of maintaining a normal weight and regularly consuming green tea for men.

Vaginally administered postbiotics derived from Lactobacillus were recently demonstrated to be effective in alleviating bacterial vaginosis and increasing pregnancy rates. However, their potential effect on sperm quality has not been well investigated. This controlled in vitro study aimed to assess the dose- and time-dependent effects of postbiotics derived from Lactobacillus rhamnosus PB01 (DSM 14870) on sperm quality parameters. The experiment was conducted in vitro to eliminate potential confounding factors from the female reproductive tract and vaginal microbiota. Sperm samples from 18 healthy donors were subjected to analysis using Computer-Aided Sperm Analysis (CASA) in various concentrations of postbiotics and control mediums at baseline, 60 min, and 90 min of incubation. Results indicated that lower postbiotic concentration (PB5) did not adversely affect sperm motility, kinematic parameters, sperm DNA fragmentation, and normal morphology at any time. However, concentrations exceeding 15% demonstrated a reduction in progressively motile sperm and a negative correlation with non-progressively motile sperm at all time points. These findings underscore the importance of balancing postbiotic dosage to preserve sperm motility while realizing the postbiotics\' vaginal health benefits. Further research is warranted to understand the underlying mechanisms and refine practical applications in reproductive health.

As the demand for rare earth elements (REEs) continues to surge in diverse industrial and medical domains, the ecological consequences of their ubiquitous presence have garnered heightened attention. Among the REEs, gadolinium (Gd), commonly used in medical imaging contrast agents, has emerged as a pivotal concern due to its inadvertent introduction into marine ecosystems via wastewater release. This study delves into the complex ecotoxicological implications of Gd contamination, focusing on its impact on the embryonic development and sperm functionality of Mytilus galloprovincialis. The findings from this study underscore the potential hazards posed by this rare element, offering a critical perspective on the ecological risks associated with Gd. Notably, this exploratory work reveals that Gd exerts a significant embryotoxic effect at elevated concentrations, with an observed half maximal effective concentration (EC50) value of 0.026 mg/L. Additionally, Gd exposure leads to a considerable reduction in sperm motility and alters sperm morfo-kinetic parameters, especially at a concentration of 5.6 mg/L. The results highlight a dose-dependent relationship between Gd exposure and the prevalence of specific malformation types in Mytilus embryos, further providing crucial insights into the potential risks imposed by this rare earth element.

UNASSIGNED: To examine the impact of tobacco smoking on seminal parameters in men with both primary and secondary infertility.
UNASSIGNED: This cross-sectional study analyzed 1938 infertile men from China who were categorized as nonsmokers (n=1,067) and smokers (n=871), with the latter group further divided into moderate smokers (1-10 cigarettes per day) (n=568) and heavy smokers (>10 cigarettes per day) (n=303). We assessed semen volume, concentration, total sperm count, progressive motility, and normal morphology following World Health Organization (WHO 2010) guidelines. A logistic regression model was used to analyze the relationships between smoking and seminal parameters while also controlling for lifestyle factors.
UNASSIGNED: The analysis demonstrated a statistically significant correlation between smoking and adverse seminal parameters in both primary and secondary infertility patients. Specifically, primary infertile men who smoked had a lower semen concentration, with heavy smokers showing a median sperm concentration of 59.2×10^6/ml compared to 68.6×10^6/ml in nonsmokers (P=0.01). The secondary infertile men who smoked exhibited reduced forward sperm motility, with heavy smokers demonstrating a median progressive motility of 44.7%, which was significantly lower than the 48.1% observed in nonsmokers (P=0.04).
UNASSIGNED: Smoking is significantly associated with detrimental effects on seminal parameters in infertile men, thus highlighting the need for cessation programs as part of fertility treatment protocols. Encouraging smoking cessation could substantially improve semen quality and fertility outcomes in this population.

Microplastics are ubiquitous environmental contaminants that have been detected in human semen from polluted areas, yet their prevalence and effects in the general population remain largely unexplored. To examine microplastic presence, abundance, polymer types, and associations with semen quality parameters in individuals without occupational exposures, this study was conducted by collecting semen samples from 40 participants undergoing premarital health assessments in Jinan, China. Raman microspectroscopy was employed to identify, quantify, and categorize microplastic polymers, sperm motility was assessed via computer-assisted analysis, and morphology was evaluated through Diff-Quik staining. Correlations between demographics, semen parameters, and microplastic content were examined by statistical analysis. We found that microplastics were detected in all semen samples, with 2 particles per sample (ranging from 0.72 to 7.02 μm). Eight distinct polymers were identified, with polystyrene (31 %) being most prevalent. Semen exposed to polystyrene demonstrated higher sperm progressive motility as compared to polyvinyl chloride exposure group (43.52 ± 14.21 % vs 19.04 ± 13.46 %). Sperm morphological abnormalities were observed but not significantly associated with specific plastic types. In conclusion, this study reveals microplastic contamination in semen from individuals without occupational exposure, with PS, PE, and PVC being the most prevalent and exhibiting differential correlations with sperm progressive motility, and highlight the need for further research into the potential reproductive impacts of microplastic exposure.

BACKGROUND: Infertility is a worldwide medical issue in which infection is recognized to play a major role. Pathogens trigger various mechanisms that impact fertility, either directly by affecting the physiological indices of semen or indirectly by disrupting the process of spermatogenesis. In the current work, the effect of in-vitro cultivation of Escherichia coli (E. coli), Candida non-albicans (C. non-albicans), and Trichomonas vaginalis (T. vaginalis) (as the most frequently reported sexually transmitted infections) was assessed on the physiological functions of the spermatozoa and the chemical characteristics of the seminal fluid.
METHODS: The semen samples were exposed to cultures of E. coli, C. non-albicans, and T. vaginalis. The study analyzed the changes in motility, agglutination, viability, DNA fragmentation index (DFI%), seminal pH, and biochemical parameters at 1/2, 1, 1.5, 2, 2.5, 3.5 and 4 hours.
RESULTS: Incubation of the semen samples with E. coli resulted in a progressive increase in agglutination, pH, and nitrite. The seminal glucose and the sperm motility, on the other hand, were reduced. The sperm vitality and seminal protein remained unaffected. C. non-albicans induced three forms of agglutination (head-to-head, tail-to-tail, and head-to-tail), lowered pH values and decreased the sperm motility, but did not alter the seminal protein, glucose, nitrite, nor the spermatozoa viability at the different tested time intervals. T. vaginalis resulted in increased seminal protein, and reduced glucose, pH, and motility. It also induced minimal agglutination and caused unchanged nitrite and sperm viability. The DFI% was increased in all pathogens with the C. non-albicans showing the highest DNA fragmentation index.
CONCLUSIONS: Urogenital infection with E. coli, C. non-albicans, or T. vaginalis is assumed to affect the quality of semen through DNA fragmentation, agglutination and altered seminal chemical microenvironment.

Exposure to metals/metalloids is reported to potentially influence semen quality. While most studies have focused on single metal impacts, the link between exposure to multiple metals and semen quality has remained less explored. The study aimed to investigate the effects of both individual and mixed metal/metalloid exposure on semen quality. A total of 330 men were recruited from three reproductive centers in eastern China. Seminal plasma levels of 25 metals/metalloids and sperm parameters were determined. We used the Generalized Linear Model (GLM) and Restricted Cubic Spline (RCS) to assess the relationships between single metals/metalloids and semen quality. The weighted quantile sum (WQS) models were then applied to evaluate the combined effect of all these metals/metalloids. We observed positive associations of exposure to lithium (Li), zinc (Zn), and magnesium (Mg) with an increased risk of below reference values for progressive motility and total motility using a logistic regression model (P < 0.05). Additionally, our results also revealed a significant inverse relationship between aluminum (Al) and both sperm concentration and count, while cobalt (Co) demonstrated a positive association with sperm concentration (P < 0.05). Notably, the WQS model indicated a significant positive association between exposure to metal/metalloid mixtures and the risk of abnormal progressive motility (OR: 1.57; 95%CI: 1.10, 2.24) and abnormal total motility (OR: 1.53; 95%CI: 1.06, 2.19), with this association primarily driven by Li, Mg, and Zn. In summary, our findings indicate that exposure to metal/metalloid mixtures might have an adverse effect on semen quality.

Anemia poses a significant healthcare challenge across different socioeconomic groups and can result in reproductive system damage through the generation of free radicals and lipid peroxidation. This study examines the protective effects of quercetin (QUE) and mirtazapine (MIR) against the reproductive damage caused by phenylhydrazine (PHZ) in mice. Fifty NMRI mice, aged 8-10 weeks with an average weight of 27.0 ± 2.0 g, were randomly divided into five groups. The control group (Group 1) received oral administration of 10 mL/kg/day of normal saline. Group 2 (PHZ group) received an initial intraperitoneal dose of 8 mg/100 g body weight of PHZ, followed by subsequent doses of 6 mg/100 g every 48 h. Group 3 received PHZ along with oral QUE at a dosage of 50 mg/kg/day. Group 4 received PHZ along with oral MIR at a dosage of 30 mg/kg/day. Group 5 received PHZ along with oral QUE at a dosage of 50 mg/kg/day and MIR at a dosage of 30 mg/kg/day. The treatment duration was 35 days. Sperm samples were collected from the caudal region of the epididymis post-euthanasia to assess the total mean sperm count, sperm viability, motility, DNA damage, and morphology. Testicular tissue was employed to quantify total antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA) concentrations, while serum levels of testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were analyzed. Additionally, various aspects, including testicular histopathology, oxidative enzyme levels, gene expression related to apoptosis and antiapoptotic pathways, and in vivo fertility index, were evaluated after 35 days. The QUE, MIR, and QUE + MIR groups showed less abnormal morphology and DNA damage, as well as better total and progressive sperm motility, motility characteristics, viability, and plasma membrane function compared to the PHZ group. QUE, MIR, and QUE + MIR administration increased TAC, SOD, and GPx activities in testicular tissue, while reducing MDA levels compared to the PHZ group. Furthermore, QUE, MIR, and QUE + MIR significantly reduced Bax, and caspase-3 expression levels, and increased Bcl-2 expression levels, compared to the PHZ group. Mice treated with QUE, MIR, and QUE + MIR exhibited an increased in vivo fertility index and plasma sex hormone levels compared to the PHZ group. These results show that QUE, MIR, and QUE + MIR might be able to improve the fertility index, boost the testicular antioxidant defense system, and control the death of germ cells. This could mean that they could be used to treat mice with PHZ-induced testicular damage.