Adverse health outcomes related to exposure to endocrine disrupting chemicals, including increased incidences of coronary heart disease, prostate and testicular cancers, and congenital disabilities, have been reported in firefighters or their offspring. We, therefore, measured the estrogenic and antiestrogenic activity of extracts of used firefighter gear to assess exposure to these agents.
Methods
Extracts and known chemical contaminants were examined for estrogenicity and antiestrogenicity in yeast cells expressing the estrogen receptor.
Results
Most extracts of used gear and phthalate diesters detectable on this gear displayed strong antiestrogenic effects. Notably, new glove and hood extracts showed significant estrogenic activity.
Conclusions
Overall, our data suggest that firefighters are exposed to both estrogenic and antiestrogenic agents, possibly phthalates that may lead to health risks observed in this occupation as a result of perturbation of hormone homeostasis.
endocrine disrupting chemicals firefighter gear, estrogenic activity contaminated equipment, firefighter occupational exposure endocrine disruptors, antiestrogenic activity gear extracts, firefighter cancer risk chemical exposure, occupational endocrine disruption screening, firefighting gear chemical contamination, endocrine disruptor high throughput screening, firefighter reproductive health exposure, occupational chemical exposure reproductive effects
PMID 26641839 26641839 DOI 10.1097/JOM.0000000000000577 10.1097/JOM.0000000000000577
Cite this article
Stevenson, M., Alexander, B., Baxter, C. S., & Leung, Y. (2015). Evaluating Endocrine Disruption Activity of Deposits on Firefighting Gear Using a Sensitive and High Throughput Screening Method. Journal of occupational and environmental medicine, 57(12), e153-e157. https://doi.org/10.1097/JOM.0000000000000577
Stevenson M, Alexander B, Baxter CS, Leung Y. Evaluating Endocrine Disruption Activity of Deposits on Firefighting Gear Using a Sensitive and High Throughput Screening Method. J Occup Environ Med. 2015;57(12):e153-e157. doi:10.1097/JOM.0000000000000577
Stevenson, Max, et al. "Evaluating Endocrine Disruption Activity of Deposits on Firefighting Gear Using a Sensitive and High Throughput Screening Method." Journal of occupational and environmental medicine, vol. 57, no. 12, 2015, pp. e153-e157.
Spermatogenesis relies on the intricate interactions between testicular somatic cells and germ cells. While follicle-stimulating hormone (FSH) and testosterone (T) are considered pivotal regulatory factors in this process, the mechanisms by which these hormones regulate the spermatogonial stem cell (SSC) microenvironment via Sertoli cells during testicular development in roosters remain unclear. Here, we examined how FSH and T regulate Sertoli-cell proliferation and the expression of glial cell-derived neurotrophic factor (GDNF) during rooster testicular development. We observed that at 4 weeks of age, the seminiferous tubules of roosters were fully developed, accompanied by the migration of spermatocytes into the lumen. At this stage, both serum and testicular levels of FSH and T were elevated in parallel. In highly purified Sertoli cells cultures, FSH treatment (25-100 ng/mL) significantly promoted proliferation and cell-cycle progression, and induced GDNF protein expression in a time- and dose-dependent manner, with the strongest response observed at 75 ng/mL. Although T did not significantly affect Sertoli cell proliferation, it markedly upregulated GDNF protein expression via the androgen receptor (AR) signaling pathway. Specifically, T (0.1-0.4 ng/mL) increased GDNF without altering proliferation, and this effect was blunted by pharmacological AR blockade (enzalutamide), indicating AR dependence. Furthermore, combined treatment with FSH and T demonstrated a synergistic effect, amplifying the expression of GDNF protein. In vivo experiments revealed that subcutaneous FSH administration increased Sertoli-cell proliferative activity (PCNA) and testicular growth, whereas testosterone administration enhanced testicular GDNF expression. Notably, combined FSH+T treatment produced the highest testicular GDNF level among groups, consistent with a synergistic effect in vivo. These findings suggest that FSH drives the expansion of Sertoli cell numbers by promoting their proliferation and cell cycle progression, while testosterone enhances the functional maturation of Sertoli cells through the regulation of GDNF expression. The synergistic actions of these two hormones together optimize the spermatogenic microenvironment, providing novel insights into the hormonal regulation of male reproduction.
To evaluate the clinical relevance of serum progesterone levels on the day of frozen embryo transfer (FET) and the dose of vaginal progesterone gel (Crinone) used for early luteal phase support (LPS) in artificial-cycle frozen embryo transfer (AC-FET). This single-center retrospective study analyzed 342 AC-FET cycles in patients aged 18-45 at Changhua Christian Hospital, Taiwan (April 2018-December 2022). Women aged 18-45 years undergoing AC-FET were included; cycles with >3 prior failed FETs, major comorbidities, donor oocytes, or missing outcome data were excluded. Pregnancy outcomes were assessed per cycle. Crinone (90 mg or 180 mg daily) was administered for 5 days after endometrial thickness ≥7 mm and progesterone <1.5 ng/mL. Serum progesterone was measured on the day of FET. Clinical pregnancy rates based on gestational sac (CPR-S), fetal heartbeat (CPR-H), and live birth rate (LBR) were evaluated. Receiver operating characteristic (ROC) evaluated the predictive value of serum progesterone levels. Associations between study variables and pregnancy outcomes were assessed using univariate and multivariable logistic regression. Comparisons of pregnancy outcomes between the high- and low-dose Crinone groups were further conducted using inverse probability of treatment weighting (IPTW) to adjust for baseline differences between dosage groups. Serum progesterone levels demonstrated poor predictive performance for CPR-S, CPR-H, and LBR (AUC 0.541-0.559) and were not independently associated with pregnancy outcomes in multivariable analyses. After adjustment using inverse probability of treatment weighting, a higher Crinone dose (180 mg vs. 90 mg) was significantly associated with higher CPR-S (OR, 1.87; 95% CI, 1.11-3.17; p = 0.020), CPR-H (OR, 2.11; 95% CI, 1.24-3.59; p = 0.006), and LBR (OR, 2.10; 95% CI, 1.31-3.38; p = 0.002). Serum progesterone levels measured on the day of FET did not predict pregnancy outcomes in AC-FET cycles using vaginal progesterone gel. A higher Crinone dose was associated with higher early clinical pregnancy rates compared with a lower dose.
Is there a difference in live birth rates at 24 months between infertile women with polycystic ovary syndrome (PCOS) who have normal versus abnormal glucose metabolism? Abnormal glucose metabolism did not significantly reduce live birth rates but was associated with increased obstetric complications. Women with PCOS are often at increased risk of glucose metabolism disorders. However, evidence about the impact of these disorders on pregnancy outcomes remains limited, particularly in Asian populations. This prospective cohort study was conducted at a reproductive care centre in Vietnam from June 2020 to August 2024. A total of 1208 women were enrolled. PARTICIPANTS/MATERIALS Eligible participants were infertile women aged 18-40 years diagnosed with PCOS (Rotterdam criteria). Comprehensive assessments included medical history, anthropometric measurements, endocrine evaluations, fasting plasma glucose (FPG), glycosylated haemoglobin (HbAlc), and oral glucose tolerance tests (OGTT). Participants were categorized into normal or abnormal glucose metabolism groups and monitored for live birth outcomes at 24 months from the first visit. MAIN Live birth rates at 24 months were comparable between women with normal versus abnormal glucose metabolism (52.7% vs 48.2%, P = 0.12). However, obstetric complications, including gestational diabetes mellitus (15.2% vs 28.0%, P < 0.001) and hypertensive disorders of pregnancy (2.3% vs 9.0%, P < 0.001), were more common in the group with abnormal glucose metabolism. In women who conceived naturally, greater waist circumference and higher Homeostatic Model Assessment of Insulin Resistance index were significantly associated with lower odds of live birth, whereas the presence of hyperandrogenism was associated with higher odds of live birth. No factors were significantly associated with live birth in the group that conceived via ovulation induction plus IUI. In the group that conceived through IVF or IVM, a higher BMI was significantly associated with a lower live birth rate. LIMITATIONS This single-centre study was conducted exclusively on infertile women from South-East Asia who had PCOS, potentially limiting generalizability to other populations. Additionally, metabolic assessments were only performed at baseline, preventing evaluation of longitudinal changes and their dynamic effects on reproductive outcomes. While no significant difference in live birth rates was observed between PCOS women with normal and abnormal glucose metabolism, the abnormal glucose metabolism group experienced higher rates of gestational complications. These findings underscore the importance of preconception metabolic screening and tailored fertility strategies that include targeted interventions to optimize reproductive and maternal outcomes in women with PCOS. This study was supported by My Duc Hospital. Lan N. Vuong reports funding from the Vietnam National Foundation for Science and Technology Development (NAFOSTED; grant number FWO.108-2022.01); Speaker and conference fees; speaker and conference fees as well as a grant; speaker, conference, and scientific board fees outside the submitted work. All other authors declare no conflicts of interest. NCT04364087.
Serum progesterone (P) levels are critical for endometrial receptivity and implantation in frozen-thawed embryo transfer (FET) cycles. However, the prognostic role of P levels measured on the day of the β-human chorionic gonadotropin (β-hCG) pregnancy test has not been fully elucidated. This study aimed to evaluate the association between β-hCG day serum P levels and pregnancy outcomes in FET cycles. This retrospective cohort study included 621 FET cycles performed between January 2023 and December 2024, of which 79.5% were conducted using hormone replacement therapy (HRT) protocols and 20.5% using natural cycle (NC) protocols. Serum P levels were measured on the day of the β-hCG pregnancy test. Receiver operating characteristic (ROC) curve analysis was used to determine protocol-specific P thresholds for predicting ongoing pregnancy (OPR). Ongoing pregnancy was defined as a viable intrauterine pregnancy confirmed by ultrasound at or beyond 12 weeks of gestation. Multivariable logistic regression was applied to identify independent predictors of OPR. ROC analysis identified optimal P thresholds of 15.5 ng/mL in NC cycles (AUC 0.821) and 14.15 ng/mL in HRT cycles (AUC 0.595). Overall, 44% of patients had serum P levels below the protocol-specific threshold. OPR was significantly higher in patients with P levels above the threshold (NC: 63.0% vs. 12.8%; 48.1% vs. 31.9%; p < 0.001). Multivariable regression demonstrated that younger maternal age and higher β-hCG day P levels independently predicted OPR. In HRT cycles, blastocyst-stage transfer was also significantly associated with improved outcomes (OR = 0.27, 95% CI 0.13-0.59; p < 0.05). Serum P levels measured on the day of the β-hCG test are significantly associated with pregnancy outcomes in both HRT and NC FET cycles. Routine monitoring of late luteal P levels and individualized luteal phase support strategies may enhance clinical success rates.