Publications by authors named "Hales B"

There is growing evidence that organophosphate esters (OPEs) can act as endocrine-disrupting chemicals. However, only a few studies have assessed the effects of OPE exposure on one of the most important endocrine glands in the body, the adrenal gland. Our aim was to test the effects of a mixture of OPEs detected in Canadian house dust on adrenal function in Sprague Dawley rats.

View Article and Find Full Text PDF

Bisphenols are a family of chemicals used in the manufacture of consumer products containing polycarbonate plastics and epoxy resins. Studies have shown that exposure to bisphenol A (BPA) may disrupt steroidogenesis and induce adverse effects on male and female reproduction, but little is known about BPA replacements. We determined the effects of six bisphenols on the steroidogenic function of MA-10 Leydig cells and KGN granulosa cells by measuring the levels of progesterone and estradiol produced by these cells as well as the expression of transcripts involved in steroid and cholesterol biosynthesis.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates how ocean acidification (OA) combined with river inputs affects water quality and acidification in estuarine environments, particularly in Tillamook Bay, Oregon.
  • Researchers collected data on carbonate chemistry and river conditions over a year to understand the influences of human development and natural processes on acidification.
  • Findings reveal that while riverine acidification significantly impacts areas with more human development, emissions-driven OA is the main contributor to acidification, making local management strategies less effective in addressing these issues.
View Article and Find Full Text PDF

Attribution of the ocean acidification (OA) signal in estuarine carbonate system observations is necessary for quantifying the impacts of global anthropogenic emissions on water quality, and informing managers of the efficacy of potential mitigation options. We present an analysis of observational data to characterize dynamics and drivers of seasonal carbonate system variability in two seagrass habitats of Puget Sound, WA, USA, and estimate how carbon accumulations due to anthropogenic emissions interact with these drivers of carbonate chemistry to determine seasonally resolved rates of acidification in these habitats. Three independent simulations of accumulation from 1765 to 2100 were run using two previously published methods and one novel method for estimation.

View Article and Find Full Text PDF

Organophosphate esters (OPEs), used as flame retardants and plasticizers, are present ubiquitously in the environment. Previous studies suggest that exposure to OPEs is detrimental to female fertility in humans. However, no experimental information is available on the effects of OPE mixtures on ovarian granulosa cells, which play essential roles in female reproduction.

View Article and Find Full Text PDF

Exposure to the organophosphate esters (OPEs), used as flame retardants and plasticizers, is associated with a variety of adverse health effects including an increase in the incidence of fatty liver diseases. The goal of this study was to investigate the effects of six OPEs, all detected in Canadian house dust, on the phenotype and function of HepG2 liver cells. We used high-content imaging to investigate the effects of these OPEs on cell survival, mitochondria, oxidative stress, lipid droplets, and lysosomes.

View Article and Find Full Text PDF

A sensitive modified QuEChERS extraction method was developed to assess the levels of free and conjugated bisphenols (BPs) in human milk collected between 2018 and 2019 from two regions of South Africa (the Limpopo Province Vhembe district, n = 194; Pretoria, n = 193) and Canada (Montreal, n = 207). Total BPA (free and conjugated) and BPS were the predominant bisphenols detected in samples from Vhembe and Pretoria, whereas total BPS was the predominant bisphenol detected in Montreal samples. The levels of total BPA in samples from Vhembe and Pretoria ranged between < MDL-18.

View Article and Find Full Text PDF

Organophosphate esters (OPEs) are used primarily as flame retardants and plasticizers. Previously, we reported that adrenal cells are important targets of individual OPEs. However, real-life exposures are to complex mixtures of these chemicals.

View Article and Find Full Text PDF

Despite the growing number of studies reporting potential risks associated with exposure to organophosphate esters (OPEs), their molecular mechanisms of action remain poorly defined. We used the high-throughput TempO-Seq™ platform to investigate the effects of frequently detected OPEs on the expression of ∼3000 environmentally responsive genes in KGN human ovarian granulosa cells. Cells were exposed for 48 h to one of five OPEs (0.

View Article and Find Full Text PDF

Adverse effects associated with exposure to brominated flame retardants have led to regulations for their use and their replacement with organophosphate esters (OPEs). However, little is known about the impact of OPEs on the adrenal, a vital endocrine gland. Here, we used a high-content screening approach to elucidate the effects of OPEs on H295R human adrenal cell phenotypic endpoints and function.

View Article and Find Full Text PDF

Organophosphate esters (OPEs) are used extensively as flame retardants and plasticizers and are found ubiquitously in the environment and human matrices. Previous studies suggested that exposure to some of these chemicals may disrupt the homeostasis of female sex hormones and have detrimental effects on female fertility. Here, we determined the effects of OPEs on the function of KGN ovarian granulosa cells.

View Article and Find Full Text PDF

There is a need to optimize SARS-CoV-2 vaccination rates amongst healthcare workers (HCWs) to protect staff and patients from healthcare-associated COVID-19 infection. During the COVID-19 pandemic, many organizations implemented vaccine mandates for HCWs. Whether or not a traditional quality improvement approach can achieve high-rates of COVID-19 vaccination is not known.

View Article and Find Full Text PDF

To test the hypothesis that migration from the thermal labels on plastic film packaging is a major source of exposure to bisphenols and alternative color developers in food, we analyzed 140 packaging materials from packaged fresh food purchased in North America. No bisphenol A (BPA) was detected in either the packaging samples or thermal labels. However, significant amounts of bisphenol S (BPS) and alternative color developers (up to 214 μg/cm) were present in thermal labels; their relative occurrence varied among stores.

View Article and Find Full Text PDF

Hundreds of xenobiotics, with very diverse origins, have been detected in human milk, including contaminants of emerging concern, personal care products and other current-use substances reflecting lifestyle. The routes of exposure to these chemicals include dermal absorption, ingestion and inhalation. Specific families of chemicals are dominant among human milk monitoring studies (e.

View Article and Find Full Text PDF

Background: End-of-life decision-making tools are used to establish a shared understanding among patients, families and healthcare providers about medical treatment and goals of care. This systematic review aimed to understand the availability and effect of end-of-life decision-making tools on: (i) goals of care and advance care planning; (ii) patient and/or family satisfaction and well-being; and (iii) healthcare utilization among racial/ethnic, cultural, and religious minorities.

Methods: A search was conducted in four electronic databases (inception to June 2021).

View Article and Find Full Text PDF

Exposure to organophosphate esters (OPEs) is extensive, yet few studies have investigated their association with hormone levels or semen quality. Here, we studied the association between urinary concentrations of OPEs and their metabolites with hormone levels and semen parameters in men (n = 117) predominantly in the 20-29 years age range who were recruited from the greater Montreal area between 2009 and 2012. Urine, serum, and semen samples were analyzed for OPEs, hormones, and semen quality, respectively.

View Article and Find Full Text PDF

The endocrine disruptive effects of bisphenol A (BPA) and brominated flame retardants (BDE-47) have led to restrictions on their use and increased the pressure to identify safe replacements for these chemicals. Although there is evidence that some of these alternatives may be toxic to spermatogonial and Leydig cells, little is known about the toxicity of emerging replacements on Sertoli cells. We used high-content imaging to compare the effects of legacy chemicals, BPA and BDE-47, to their corresponding replacements.

View Article and Find Full Text PDF

The replacement of regulated brominated flame retardants and plasticizers with organophosphate esters (OPEs) has led to their pervasive presence in the environment and in biological matrices. Further, there is evidence that exposure to some of these chemicals is associated with reproductive toxicity. Using a high-content imaging approach, we assessed the effects of exposure to 9 OPEs on cells related to reproductive function: KGN human granulosa cells, MA-10 mouse Leydig cells, and C18-4 mouse spermatogonial cells.

View Article and Find Full Text PDF

Bisphenols are a family of chemicals commonly used to produce polycarbonate plastics and epoxy resins. Exposure to bisphenol A (BPA) is associated with a variety of adverse effects; thus, many alternatives to BPA, such as bisphenol AF (BPAF) and bisphenol S (BPS), are now emerging in consumer products. We have determined the effects of 3 bisphenols on endochondral ossification and the transcriptome in a murine limb bud culture system.

View Article and Find Full Text PDF

The developmental and reproductive toxicity associated with exposure to phthalates has motivated a search for alternatives. However, there is limited knowledge regarding the adverse effects of some of these chemicals. We used high-content imaging to compare the effects of mono (2-ethylhexyl) phthalate (MEHP) with six alternative plasticizers: di-2-ethylhexyl terephthalate (DEHTP); diisononyl-phthalate (DINP); di-isononylcyclohexane-1,2-dicarboxylate (DINCH); 2-ethylhexyl adipate (DEHA); 2,2,4-trimethyl 1,3-pentanediol diisobutyrate (TXIB) and di-iso-decyl-adipate (DIDA).

View Article and Find Full Text PDF

Background: Recently immigrated and ethnic minority patients in Ontario, Canada are more likely to receive aggressive life-prolonging treatment at the end of life in comparison to other patients. To explore this finding further, this survey-based observational study aimed to evaluate satisfaction with the quality of end-of-life care for patients from diverse ethnocultural backgrounds.

Methods: The End-of-Life Satisfaction Survey was used to measure satisfaction with the quality of inpatient end-of-life care from the perspective of next-of-kin of recently deceased patients at Sunnybrook Health Sciences Centre in Toronto, Ontario (between March 2012 to May 2019).

View Article and Find Full Text PDF

Over the past century, evidence has emerged that endocrine disrupting chemicals (EDCs) have an impact on reproductive health. An increased frequency of reproductive disorders has been observed worldwide in both wildlife and humans that is correlated with accidental exposures to EDCs and their increased production. Epidemiological and experimental studies have highlighted the consequences of early exposures and the existence of key windows of sensitivity during development.

View Article and Find Full Text PDF

NifB, a radical SAM enzyme, catalyzes the biosynthesis of the L cluster (FeSC), a structural homolog and precursor to the nitrogenase active-site M cluster ([MoFeSC·R-homocitrate]). Sequence analysis shows that NifB contains the CxxCxxxC motif that is typically associated with the radical SAM cluster ([FeS]) involved in the binding of S-adenosylmethionine (SAM). In addition, NifB houses two transient [FeS] clusters (K cluster) that can be fused into an 8Fe L cluster concomitant with the incorporation of an interstitial carbide ion, which is achieved through radical SAM chemistry initiated at the [FeS] cluster upon its interaction with SAM.

View Article and Find Full Text PDF