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Introduction: Perfluoroalkylated substances (PFAS) such as carboxylic acids, and sulfonic acids were manufactured in high quantities and are ubiquitous environmental contaminants. These chemicals persist in the environment and tend to bioaccumulate. Materials and Methods:&nb...

Stress plus chemical exposure may produce effects not observed with chemical exposure alone, which would be of particular concern for environmental justice (EJ) since EJ communities experience higher levels of chronic stress. Therefore, there is a need for New Approach Methodolog...

Thyroid-relevant bioassay data in the publicly available ToxCast database (and browseable in the CompTox Chemicals Dashboard) will be reviewed by molecular-initiating event. Example case studies of how to interpret the suite of bioactivity assay data will be shown. Work-in-progre...

Sensitivity to potential endocrine disrupting chemicals in the environment varies across species and is influenced by sequence conservation of their nuclear receptor targets. Here, we evaluated a multiplexed, in vitro assay testing receptors relevant...

Stress plus chemical exposure may produce effects not observed with chemical exposure alone. Therefore, there is a need for new approach methods that can rapidly screen chemicals for their interaction with stressed biological systems, which will advance understanding of inter- an...

Since the origin of the term “Endocrine Disruptors” at the 1991 Wingspread Meeting, led by Dr Theo Colborn, the field has evolved from description of the in vitro and in vivo effects EDCs to the utilization of mechanisms of toxicity and key events in Adverse Outcome P...

 Thyroid hormones (TH) are critical for brain development. Serum measures of TH are used for regulatory decision-making purposes because of concern for neurodevelopmental disorders and serum T4 represents a key integrator node in the Adverse Outcome Pathway (AOP) upstream fr...

This is an overview slide presentation of previously publication information. 

Since initial regulatory action in 2010 in Canada, bisphenol A (BPA) has been progressively replaced by structurally related alternative chemicals. Unfortunately, many of these chemicals are data-poor, limiting toxicological risk assessment. We used high-throughput transcriptomic...

The presentation gives an overview of ER and AR models, assays relevant to thyroid adverse outcome pathways, and work on the high-throughput steroidogenesis assay and resultant models. The slides serve as a reference to users who are interested in finding and understanding these ...

Overview of James Lazorchak educational and work history. Presents some of my significant contributions to EPA and the scientific literature and introduces one of the most important Endocrine disruption experiments conducted at the Canadian Experimental Lakes Area.

In teleost fish, the balance between steroidal estrogens and androgens is essential during sexual differentiation and this balance is in turn dependent on the availability and activity of steroid synthesizing enzymes such as aromatase, the enzyme responsible for the conversion of...

This chapter covers both developmental and reproductive effects of brominated flame retardants (BFRs) with emphasis on polybrominated diphenyl ethers (PBDEs). BFRs belong to a large group of organohalogen chemicals. They are highly persistent, bioaccumulative, and cause adverse e...

1. Introduction Over the last decade, the release of endocrine-disrupting chemicals (EDCs) into the environment has become a matter of unprecedented public and scientific debate. EDCs are capable of interfering with and altering functions of the endocrine (hormone) system of livi...

Analysis of mechanistic evidence as part of a human health assessment can inform biological plausibility and human relevance of effects observed in in-vivo and in-vitro experimental models. Since their identification, the Key Characteristics of Carcinogens have served as an appro...

Endocrine-disrupting chemicals have the ability to interfere with and alter functions of the hormone system, leading to adverse effects on reproduction, growth and development. Despite growing concerns over their now ubiquitous presence in the environment, endocrine-related human...

Since the introduction of ten key characteristics of carcinogens as a basis for organizing mechanistic data on carcinogenesis, the National Academy of Sciences has recommended that key characteristics approaches also be developed for noncancer hazards. The aim of this project was...

Since the introduction of ten key characteristics of carcinogens as a basis for organizing mechanistic data on carcinogenesis, the National Academy of Sciences has recommended that key characteristics approaches also be developed for noncancer hazards. The aim of this project was...

Flame retardants are chemical mixtures added to materials after manufacturing to reduce the amount of time it would take a small open flame to ignite the item. These compounds are volatile and continuously leach out of materials into the environment. Therefore, they are ubiquitou...

Polybrominated diphenyl ethers (PBDEs) are persistent environmental pollutants considered as neurotoxicants and endocrine disruptors with important biological effects ranging from alterations in growth, reproduction, and effects on the hypothalamus-pituitary-adrenal axis. The vas...

Exposure to endocrine-disrupting compounds (EDCs) can lead to perturbations of normal, steroid hormone production in vertebrates, ultimately leading to adverse reproductive or developmental effects. Liquid chromatography mass spectrometry (LC-MS) methods are the gold standard for...

A commitment under the “Toxic Substances and Areas of Concern” Focus Area of the Great Lakes Restoration Initiative (GLRI) was to identify emerging contaminants and evaluate their potential impacts on Great Lakes fish and wildlife. Here we present data and results fro...

Background: High-throughput and computational tools provide a new opportunity to calculate cumulative bioactivity of exposure to diverse chemicals acting through a common mechanism. Objective: We used high throughput bioactivity data and exposure predictions from the U.S. EPA&rsq...

The process of molting, known alternatively as ecdysis, is a feature integral within the life-cycles of species across the arthropod phylum. Regulation occurs as a function of the interaction of ecdysteroid hormones with the arthropod nuclear ecdysone receptor (EcR) and triggerin...

The US EPA and other international regulatory agencies are required to evaluate certain chemicals for their ability to be “endocrine disruptors”, which includes testing for activity against the endocrine pathways, including the estrogen receptor (ER) pathway. The curr...