QSAR: Using the Past to Study the Present.

Quantitative structure-activity relationships (QSAR) is a method for predicting the physical and biological properties of small molecules; it is in use in industry and public services. However, as any scientific method, it is challenged by more and more requests, especially considering its possible role in assessing the safety of new chemicals. To answer the question whether QSAR, by exploiting available knowledge, can build new knowledge, the chapter reviews QSAR methods in search of a QSAR epistemology. QSAR stands on tree pillars, i.e., biological data, chemical knowledge, and modeling algorithms. Usually the biological data, resulting from good experimental practice, are taken as a true picture of the world; chemical knowledge has scientific bases; so if a QSAR model is not working, blame modeling. The role of modeling in developing scientific theories, and in producing knowledge, is so analyzed. QSAR is a mature technology and is part of a large body of in silico methods and other computational methods. The active debate about the acceptability of the QSAR models, about the way to communicate them, and the explanation to provide accompanies the development of today QSAR models. An example about predicting possible endocrine-disrupting chemicals (EDC) shows the many faces of modern QSAR methods.

The impact of endocrine-disrupting chemicals on stem cells: Mechanisms and implications for human health.

Endocrine-disrupting chemicals (EDCs) are compounds, either natural or man-made, that interfere with the normal functioning of the endocrine system. There is increasing evidence that exposure to EDCs can have profound adverse effects on reproduction, metabolic disorders, neurological alterations, and increased risk of hormone-dependent cancer. Stem cells (SCs) are integral to these pathological processes, and it is therefore crucial to understand how EDCs may influence SC functionality. This review examines the literature on different types of EDCs and their effects on various types of SCs, including embryonic, adult, and cancer SCs. Possible molecular mechanisms through which EDCs may influence the phenotype of SCs are also evaluated. Finally, the possible implications of these effects on human health are discussed. The available literature demonstrates that EDCs can influence the biology of SCs in a variety of ways, including by altering hormonal pathways, DNA damage, epigenetic changes, reactive oxygen species production and alterations in the gene expression patterns. These disruptions may lead to a variety of cell fates and diseases later in adulthood including increased risk of endocrine disorders, obesity, infertility, reproductive abnormalities, and cancer. Therefore, the review emphasizes the importance of raising broader awareness regarding the intricate impact of EDCs on human health.

Adrenal Vein Sampling for Primary Aldosteronism: Recommendations From the Australian and New Zealand Working Group.

Adrenal vein sampling (AVS) is the current recommended procedure for identifying unilateral subtypes of primary aldosteronism (PA), which are amenable to surgery with the potential for cure. AVS is a technically challenging procedure usually undertaken by interventional radiologists at tertiary centres. However, there are numerous variations in AVS protocols relating to patient preparation, sampling techniques and interpretation which may impact the success of AVS and patient care. To reduce practice variations, improve the success rates of AVS and optimise patient outcomes, we established an Australian and New Zealand AVS Working Group and developed evidence-based expert consensus recommendations for the preparation, performance and interpretation of AVS. These recommendations can be used by all healthcare professionals in a multidisciplinary team who look after the diagnosis and management of PA.

The use of in vitro bioassays and chemical screening to assess the impact of a minimally processed vegetable facility on wastewater quality.

Fruit- and vegetable-processing facilities may contaminate wastewater via contaminants found in the produce and disinfecting chemicals used. These contaminants may include agrochemicals, pesticides, and disinfectants such as chlorine and quaternary ammonium compounds (QACs). Some compounds may exhibit harmful endocrine-disrupting activity. This study investigated the impact of a minimally processed vegetable facility on wastewater quality via in vitro bioassays and chemical screening. Estrogen activity was assessed via a yeast estrogen screen (YES), and (anti-)androgenic and glucocorticoid activities were evaluated via an MDA-kb2 reporter gene assay. The samples were screened via gas and liquid chromatography-tandem mass spectrometry (GC-MS/MS and LC-MS/MS) to identify target compounds, and GC coupled with time-of-flight mass spectrometry (GC-TOFMS) was used for non-targeted screening. Sample complexity and chemical profiles were assessed using GC-TOFMS. Estrogenic activity was detected in 16 samples (n = 24) with an upper limit of 595 ± 37 ng/L estradiol equivalents (EEqs). The final wastewater before discharge had an EEq of 0.23 ng/L, which is within the ecological effect-based trigger value range for the estrogenic activity of wastewater (0.2-0.4 ng/L EEq). Androgenic activity was detected in one sample with a dihydrotestosterone equivalent (DHTEq) value of 10 ± 2.7 ng/L. No antiandrogenic activity was detected. The GC-MS/MS and LC-MS/MS results indicated the presence of multiple pesticides, nonylphenols, triclocarban, and triclosan. Many of these compounds exhibit estrogenic activity, which may explain the positive YES assay findings. These findings showed that wastewater from the facility contained detergents, disinfectants, and pesticides and displayed hormonal activity. Food-processing facilities release large volumes of wastewater, which may affect the quality of the water eventually being discharged into the environment. We recommend expanding conventional water quality monitoring efforts to include additional factors like endocrine activity and disinfectant byproducts.

Periampullary duodenal neuroendocrine tumor in a patient with neurofibromatosis-1: A case report.

BACKGROUND: Patients with neurofibromatosis type 1 (NF1) are exposed to a higher risk of developing neuroendocrine tumors (NETs). Periampullary neuroendocrine neoplasms (NENs) in NF1 patients primarily affect the duodenum and periampullary region. CASE SUMMARY: A 50-year-old male patient was admitted to our hospital due to progressive skin and scleral yellowing for over 6 months. An abdominal contrast-enhanced computed tomography scan revealed a tumor in the periampullary region, which measured 1.2 cm × 1.4 cm in size and showed a progressive enhancement. Magnetic resonance cholangiopancreatography indicated the dilation of intrahepatic and extrahepatic bile ducts. The patient was diagnosed with an ampullary tumor with the possibility of malignancy. A Whipple procedure was performed. Microscopically, the duodenum tumor was found to invade the mucosa, sphincter, and muscular layer of the duodenal papilla. Histologic hematoxylin and eosin staining confirmed the presence of duodenal G1 NET. Subsequently, a bibliometric analysis was performed to evaluate the state of NEN research. Publications about periampullary NENs showed an annual increase, with most of them focusing on the treatment and diagnosis of NENs. CONCLUSION: This article reported a case of periampullary duodenal NET in a patient with NF1, and a bibliometric analysis was conducted.

Experience of endoscopy versus surgery as initial management of chronic pancreatitis.

INTRODUCTION AND AIM: Chronic pancreatitis is a pathologic fibroinflammatory syndrome of the pancreas. Treatment includes medical management and endoscopic and/or surgical interventions. Our aim was to describe progression in patients with chronic pancreatitis whose initial management was either endoscopic or surgical. MATERIAL AND METHODS: A retrospective, analytic, observational, and longitudinal study was conducted that included patients diagnosed with chronic pancreatitis treated at the Hospital de Especialidades of the Centro Médico Nacional Siglo XXI from 2015 to 2021. RESULTS: Twenty-two patients were included in the study; 12 underwent endoscopy and 10 underwent surgery. The mean number of interventions performed was 3 in the endoscopic management group and 1.1 in the surgical management group (p = 0.001). Regarding pain remission (partial or total), results were statistically significant in favor of surgical management (p = 0.035). Of the 12 patients that initially underwent endoscopy, 7 (58.3%) eventually required surgery during follow-up. There were no statistically significant differences with respect to opioid and pancreatin use, readmissions, weight loss, steatorrhea, newly diagnosed diabetes, or deaths during follow-up. CONCLUSION: Pain is the main indication for invasive treatment, whether endoscopic or surgical, in patients with chronic pancreatitis. Slightly more than half of the patients that were initially managed endoscopically required surgery during follow-up. Management decisions should be multidisciplinary and individualized for each patient.

Optimal testing time for cerebral heterotopia formation in the rat comparative thyroid assay, a downstream indicator for perinatal thyroid hormone insufficiency.

In a past study, we proposed a modified Comparative Thyroid Assay (CTA) with additional examinations of brain thyroid hormone (TH) concentrations and brain histopathology but with smaller group sizes. The results showed that the modified CTA in Sprague Dawley rats detected 10 ppm 6-propylthiouracil (6-PTU)-induced significant suppressions of serum/brain TH concentrations in offspring. To confirm the reliability of qualitative brain histopathology and identify the optimal testing time for heterotopia (a cluster of ectopic neurons) in the modified CTA, brain histopathology together with serum/brain TH concentrations were assessed in GD20 fetuses and PND2, 4, 21, and 28 pups using a similar study protocol but with a smaller number of animals (N=3-6/group/time). Significant hypothyroidism was observed and brain histopathology revealed cerebral heterotopia formation in PND21 and PND28 pups, with likely precursor findings in PND2 and PND4 pups but not in GD20 fetuses. This study confirmed that the optimal testing time for cerebral heterotopia in rat CTA was PND21 and thereafter. These findings suggest that cerebral heterotopia assessment at appropriate times may be a useful alternative to the original CTA design.

The mixture of non-persistent endocrine-disrupting chemicals in relation to endometriosis.

Non-persistent endocrine-disrupting chemicals (EDCs) are of significant concern due to their reproductive toxicity. Previous research reported a relationship between a single type of EDCs and endometriosis. Yet, evidence regarding mixed exposure of multiple categories of EDCs is scarce. Between 2014 and 2018, our hospital-based case-control study recruited 238 endometriosis cases diagnosed by laparoscopy and 296 normal controls in China. Seventeen non-persistent EDCs (phthalates and bisphenols) were measured in urine. The association of single EDC with endometriosis was estimated using logistic regression, while the association between EDC mixture and endometriosis was modeled by Bayesian kernel machine regression (BKMR), quantile-based g-computation (q-gcomp), and principal component analysis (PCA). Consistent results were observed in both single and mixture models where phthalates and bisphenols were associated with increased risk of endometriosis (mixture effect: adjusted odds ratio (aOR)=1.44, 1.22-1.70) and the major contributors were bisphenol A (BPA) and the metabolites of di(2-ethylhexyl) phthalate (DEHP). Interaction analysis showed that bisphenols exhibited significant synergistic interactions with phthalates. Our results suggest that non-persistent EDCs are associated with endometriosis but the underlying mechanisms remain to be elucidated. Our finding may have important public health implications in preventing endometriosis.

Subtotal Versus Total Parathyroidectomy for the Management of Tertiary Hyperparathyroidism: A Systematic Literature Review and Meta-Analysis of Optimal Surgical Modality.

Background: Surgery is the definitive treatment option for tertiary hyperparathyroidism (THPT), however, the optimal surgical approach remains unclear. We aimed to compare total parathyroidectomy (PTX) with auto-transplantation vs subtotal PTX for THPT through a systematic review and meta-analysis.Methods: PubMed, Embase, and Web of Science were searched for studies comparing outcomes of total vs subtotal PTX for THPT. A total of 28 studies (n = 1000 patients) met the inclusion criteria.Results: The mean age was 46.5 years and 53% were female. The proportion of females (59% vs 49%) was higher in the total PTX with auto-transplantation cohort (P = .008). Both procedures had similar preoperative calcium and PTH levels. Postoperative and 6-month calcium and PTH were also comparable between groups, except transiently higher post-operative PTH in the total PTX with auto-transplantation cohort (P = .03). Hypercalcemia cure rates were 98%-100% with no difference between surgical techniques (P = .67). Safety profiles were comparable and low.Conclusions: Total PTX with auto-transplantation and subtotal PTX yield similar efficacy and safety for THPT, with no significant differences in cure rates, recurrence, complications, or biochemical control.

Transcriptome analysis elucidates mating affects the expression of intra-/extra-ovarian factors, thereby influencing ovarian development in the mud crab Scylla paramamosain.

Prior to the pubertal molt and mating, the ovarian development of the mud crab Scylla paramamosain was primarily at stage II. However, immediately after mating, female crabs initiate vitellogenesis, and their ovaries quickly develop. The aim of this study was to identify differentially expressed genes associated with ovarian development in the mud crab before and after mating, in order to elucidate the influence of mating on ovarian development using comparative transcriptomics. The KEGG pathway analysis results indicated that ribosome and ribosome-related pathways were highly associated with ovarian development at stage II across both transcriptomes, likely to support the subsequent vitellogenesis by providing the necessary materials. Additionally, the neurodegeneration, MAPK, cAMP and PLD pathways were active in regulating oogonia differentiation, oocyte proliferation and vitellogenesis after mating. Meanwhile, certain intra-ovarian factors, such as the cell cycle-related genes cyclin B and APC, the forkhead box family genes Foxl2 and slp1, the SOX family gene SOX5-like, the hormone-related genes SULT1E1 and Eip74EF-like, the growth factor-related genes VEGFD-like and CUBE1-like, as well as HPS10 and tra1-like, have essential functions in regulating ovarian development after mating. Furthermore, the receptors of extra-ovarian hormones, such as RPCHR, HR4, and ILR1, as well as the neurotransmitter receptor 5-HTR4, were involved in ovarian development. It is believed that ovarian development is controlled by the coordinated action of both intrinsic and extrinsic endocrine factors, and these factors are influenced by mating. Finally, the analysis of epigenic modification-related genes, transcription factors, and target genes revealed the regulation of gene expression. Our study indicated that, those genes work in a coordinated manner to regulate the complex processes of follicle cell development, oogonia differentiation, oocyte proliferation, and vitellogenesis during ovarian development.

Adjuvant endocrine therapy and risk of contralateral breast cancer: a systematic review and meta-analysis of observational studies.

PURPOSE: Randomized clinical trials support reductions in contralateral breast cancer (CBC) risk with use of adjuvant endocrine therapy, however, real-world treatment effects, particularly for subgroups of breast cancer survivors, remain inconclusive. To address this, population-based observational studies of adjuvant endocrine therapy and CBC were synthesized and meta-analyzed. METHODS: PubMed and Embase databases were systematically searched for observational studies of endocrine therapy use and CBC risk. Random effects meta-analyses estimated summary relative risks (RRs) and 95% confidence intervals (CIs) for associations between endocrine therapy (ever use of tamoxifen and/or aromatase inhibitors (AIs)) and CBC risk. Heterogeneity across studies was assessed using the I2 test. Subgroup analyses were conducted by study design, menopausal status, and CBC estrogen receptor (ER)-status. RESULTS: Seventeen eligible observational studies (n = 287,576 breast cancer survivors) published between 1995 and 2019 were included. Endocrine therapy use was associated with reduced CBC risk (RR:0.62, 95% CI:0.53, 0.73, I2 = 84.8%, p < 0.0001). No heterogeneity was observed by study design (phet = 0.9). Similar reductions were observed in analyses restricted to tamoxifen use. As only two studies assessed AI use, estimates could not be meta-analyzed. In subgroup analyses, there were no differences in CBC risk reduction by menopausal status (phet = 0.22). Endocrine therapy reduced risk of ER-positive (RR:0.55, 95% CI:0.43, 0.70) but not ER-negative CBC (RR:1.26, 95% CI:0.95, 1.66) (phet < 0.001). CONCLUSION: This meta-analysis of observational studies supports a reduction in CBC risk with endocrine therapy among breast cancer survivors, in concert with evidence synthesized from randomized clinical trials, and highlights differences in endocrine therapy effectiveness by ER-status of CBC.

Nursing care during management of recurrent pheochromocytoma: A case study.

BACKGROUND: Pheochromocytoma can occur in patients with multiple endocrine neoplasia type 2, placing them at increased risk of tumour recurrence after surgical resection. Therefore, management of pheochromocytoma in these patients is a clinical challenge. AIMS: We aim to present and discuss the nursing management of patient with recurrent pheochromocytoma. STUDY DESIGN: Case studies. We reviewed and retrieved the necessary information from the medical records. RESULTS: A 34-year-old female with a history of medullary thyroid carcinoma and pheochromocytoma complicated by cardiomyopathy, who had undergone surgical resections 6 years ago, presented with abdominal pain for 1 day and was diagnosed with recurrent bilateral pheochromocytoma, hypertensive crisis, acute heart failure, and acute renal failure. Eight hours after hospital admission, she experienced sudden cardiac arrest and received cardiopulmonary resuscitations. She was then supported under extracorporeal membrane oxygenation and continuous renal replacement therapy (CRRT). The adrenal tumour was successfully treated with absolute ethanol ablation followed by gelatin sponge particle embolization, a management approach which has not been reported previously. She had a satisfactory recovery. CONCLUSIONS: A comprehensive nursing management approach, including prone ventilation; safe transportation; close cardiopulmonary monitoring; pre-, intra- and post-procedure care; individualized early rehabilitation; and psychological supports, should be applied to improve the prognoses in patients with similar medical conditions. RELEVANCE TO CLINICAL PRACTICE: Bilateral adrenal pheochromocytoma can be managed by absolute ethanol ablation followed by gelatin sponge particle embolization. Comprehensive nursing management, including a team effort regarding patient positioning, transportation, close monitoring, early rehabilitation and psychological support, should be provided during the peri-procedure period.

Exploring risk factors for endocrine-related immune-related adverse events: Insights from meta-analysis and Mendelian randomization.

This study utilized meta-analysis and Mendelian randomization (MR) to identify risk factors for endocrine-related immune-related adverse events (EirAEs) and to ascertain whether EirAEs confer better prognosis of immunotherapy. The meta-analysis identified several risk factors for EirAEs, including elevated baseline TSH (OR = 1.30, 95% CI 1.10-1.53), positive TgAb (OR = 14.23, p < .001), positive TPOAb (OR = 3.75, p < .001), prior thyroid-related medical history (OR = 4.19), increased BMI (OR = 1.11), combination immune checkpoint inhibitors (ICIs) therapy with targeted treatment (OR = 2.71, 95% CI 2.11-3.47), and dual ICI therapy (OR = 3.26, 95% CI 2.22-4.79). MR analysis further supported causalities between extreme BMI, hypothyroidism, and irAEs from a genetic perspective. In addition, cancer patients who experienced EirAEs exhibited significantly prolonged PFS (HR = 0.84, 95% CI 0.73-0.97) and OS (HR = 0.59, 95% CI 0.45-0.76) compared to those without. These findings provide valuable insights for clinical decision-making among healthcare professionals and offer direction for future research in this field.

Neoadjuvant sunitinib plus exemestane in post-menopausal women with hormone receptor-positive/HER2-negative early-stage breast cancer (SUT_EXE-08): a phase I/II trial.

Neoadjuvant endocrine therapy (NET) for hormone receptor-positive (HR+) breast cancer might be as effective as chemotherapy, with a better toxicity profile. Blocking a crucial process such as angiogenesis with sunitinib may have a synergistic effect with NET. We aimed to assess the efficacy and safety of neoadjuvant sunitinib plus exemestane in early-stage HR+/HER2-negative breast cancer. In this phase I/II study, postmenopausal women with HR+/HER2- stage II-III breast cancer received neoadjuvant exemestane at conventional dose of 25mg plus sunitinib in a 3 + 3 design at 25mg (3/1weeks scheme) or 37.5mg continuous dose, for 6 months. Coprimary endpoints were the recommended dose of sunitinib combined with exemestane and objective response. Secondary endpoints included safety and biomarkers of early response. For 15 months, 18 patients were enrolled, 15 at sunitinib 25mg and 3 at 37.5mg. Median age was 73, 77% of patients had T2 tumors and 67% node-positive disease. The most common grade 2 toxicity was asthenia (44%), as was hypertension (22%) for grade 3. No grade 4-5 were reported. Twelve patients (66%) achieved an objective response. VEGFR-2 levels significantly decreased after one month of treatment. Differential gene expression analysis showed downregulation of ESR1, PGR and NAT1 in post-treatment samples and upregulation of EGFR, MYC, SFRP1, and FOXC1. PAM50 analysis on 83% of patients showed a prevalence of luminal A subtype, both in pre-treatment (63.6%) and post-treatment tumors (54.5%). Sunitinib plus exemestane was associated with substantial yet reversible toxicities, providing safety, efficacy and biological impact insights of combining an antiangiogenic drug with hormone therapy in early-stage breast cancer.Trial registration: Registered with ClinicalTrials.gov, NCT00931450. 02/07/2009.

Large scale screening and quantification of micropollutants in fish from the coastal waters of Cochin, India: Analytical method development and health risk assessment.

Urban estuarine and coastal water receive several micropollutants through industrial and agricultural influxes. The bioaccumulation of these micropollutants in fish and their entry into the coastal population's food chain raises significant food safety concerns. Hence, a comprehensive analytical method was developed for ultra-trace level quantification of 345 micropollutants in fish. The optimized sample preparation method could extract compounds suitable for both GC-MS/MS and LC-MS/MS analysis simultaneously. The target list of contaminants included 278 agricultural pesticides and also 102 endocrine disruptors covering polyaromatic hydrocarbons, polychlorinated biphenyls, organochlorines, and endocrine-disrupting pesticides. The GC-MS/MS with large volume injection (LVI) technique, and LC-MS/MS operating in MRM mode, achieved an LOQ of <2.00 ng/g for most of the analytes. The extraction strategy involved tri-phase partitioning between water, acidified acetonitrile, and hexane, followed by salting out. Dispersive solid phase cleanup (dSPE) with C18, Z-Sep+, CaCl2, and MgSO4 was able to reduce the matrix influence, and the method achieved satisfactory recovery in the range of 70.0-120.0 % for all the target analytes. The repeatability and reproducibility relative standard deviation values of the measured analytes were <20.0 %, and the Horwitz ratio values were well below 2. The method was used to accurately measure the target micropollutants in fish from the Cochin estuary, the highly urbanized portion of the Vembanad Lake, and an important Ramsar site. At least one or more of the 41 different micropollutants were identified and quantified in about 90.7 % of the 108 samples analyzed. The importance of large-scale screening and trace-level quantification methods in environmental monitoring and risk assessment is underscored by the results. The risk assessment showed a moderate risk of exposure to the nearby coastal population through the food chain.

An in vitro approach reveals molecular mechanisms underlying endocrine disruptor-induced epimutagenesis.

Endocrine disrupting chemicals (EDCs) such as bisphenol S (BPS) are xenobiotic compounds that can disrupt endocrine signaling due to steric similarities to endogenous hormones. EDCs have been shown to induce disruptions in normal epigenetic programming (epimutations) and differentially expressed genes (DEGs) that predispose disease states. Most interestingly, the prevalence of epimutations following exposure to many EDCs persists over multiple generations. Many studies have described direct and prolonged effects of EDC exposure in animal models, but many questions remain about molecular mechanisms by which EDC-induced epimutations are introduced or subsequently propagated, whether there are cell type-specific susceptibilities to the same EDC, and whether this correlates with differential expression of relevant hormone receptors. We exposed cultured pluripotent (iPS), somatic (Sertoli and granulosa), and primordial germ cell-like (PGCLC) cells to BPS and found that differential incidences of BPS-induced epimutations and DEGs correlated with differential expression of relevant hormone receptors inducing epimutations near relevant hormone response elements in somatic and pluripotent, but not germ cell types. Most interestingly, we found that when iPS cells were exposed to BPS and then induced to differentiate into PGCLCs, the prevalence of epimutations and DEGs was largely retained, however, >90% of the specific epimutations and DEGs were replaced by novel epimutations and DEGs. These results suggest a unique mechanism by which an EDC-induced epimutated state may be propagated transgenerationally.

Therapeutic approaches targeting the gut microbiota in ischemic stroke: current advances and future directions.

Ischemic stroke (IS) is the predominant form of stroke pathology, and its clinical management remains constrained by therapeutic time frame. The gut microbiota (GM), comprising a multitude of bacterial and archaeal cells, surpasses the human cell count by approximately tenfold and significantly contributes to the human organism's growth, development, and overall well-being. The microbiota-gut-brain axis (MGBA) in recent years has established a strong association between gut microbes and the brain, demonstrating their intricate involvement in the progression of IS. The regulation of IS by the GM, encompassing changes in composition, abundance, and distribution, is multifaceted, involving neurological, endocrine, immunological, and metabolic mechanisms. This comprehensive understanding offers novel insights into the therapeutic approaches for IS. The objective of this paper is to examine the mechanisms of interaction between the GM and IS in recent years, assess the therapeutic effects of the GM on IS through various interventions, such as dietary modifications, probiotics, fecal microbiota transplantation, and antibiotics, and offer insights into the potential clinical application of the GM in stroke treatment.

Roger Guillemin: A Century of Life, A Legacy of Endocrine Discoveries.

Dr. Roger Guillemin was a French physiologist who won the Nobel Prize in 1977. His pioneering research and fierce competition led to the isolation and identification of hypothalamic hormones, including thyrotropin-releasing factor (TRF), luteinizing hormone-releasing factor (LRF), and somatostatin. These discoveries transformed the knowledge of the role of the hypothalamus in endocrine control. His work not only helped in the advancement of scientific understanding but also directed the field for decades. His research continues to resonate today, shaping modern endocrinology and impacting the global treatment of endocrine disorders.

Profiling the endocrine disrupting properties of triazines, triazoles and short-chain PFAS.

Persistent, mobile and toxic (PMT) compounds released to the environment are likely to pollute drinking water sources due to their slow environmental degradation (persistency) and high water solubility (mobility). The aim of the present study was to create in vitro hazard profiles for sixteen triazoles, nine triazines and eleven PFAS based on their agonistic and antagonistic effects in estrogen receptor (ER), androgen receptor (AR) and thyroid hormone receptor (TR) reporter gene assays, their ability to bind human transthyretin (TTR), and their effects on steroidogenesis. The triazole fungicides tetraconazole, bitertanol, fenbuconazole, tebuconazole, cyproconazole, difenoconazole, propiconazole, paclobutrazol and triadimenol had agonistic or antagonistic effects on the ER and AR. Difenoconazole, propiconazole and triadimenol were also found to be TR antagonists. The triazine herbicide ametryn was an ER, AR and TR antagonist. The same nine triazole fungicides and the triazines atrazine, deethyl-atrazine and ametryn affected the secretion of steroid hormones. Furthermore, PFAS compounds PFBS, PFHxS, PFHxA, PFOS, PFOA and GenX and the triazoles bitertanol, difenoconazole and 4-methyl benzotriazole were found to displace T4 from TTR. These results are in line with earlier in vitro and in vivo studies on the endocrine disrupting properties of triazines, triazoles and PFAS. The present study demonstrates that this battery of in vitro bioassays can be used to profile compounds from different classes based on their endocrine disrupting properties as a first step to prioritize them for further research, emission reduction, environmental remediation and regulatory purposes.