Science On Demand: A Roundup of SOT Webinar Recordings Released October 1–December 31, 2023

By James Luyendyk posted 01-04-2024 12:52

Many of the webinars hosted by SOT Regional Chapters, Special Interest Groups, and Specialty Sections—collectively known as the SOT Component Groups—are recorded and added to the SOT Video Library so that SOT members and others can watch these valuable presentations at any time. SOT Committees, the Postdoctoral Assembly, and Graduate Student Leadership Committee also host webinars that are recorded. In this blog, you will find a listing of all the recent webinar recordings that have been added to the SOT Video Library.

In Silico Tools for Prediction and Mechanistic Interpretation of Systemic and Topical Toxicity

Hosted by: SOT Risk Assessment Specialty Section
Speaker: Alexander Tropsha, PhD, K.H. Lee Distinguished Professor, University of North Carolina at Chapel Hill
Advances in basic and applied science are continuously presenting opportunities to employ non-animal methodologies, including computational methods which, when qualified, could replace animal testing methods to support regulatory submissions. Dr. Tropsha presents new computational tools (PreS/MD and STopTox) for rapid and accurate prediction of chemical-induced toxicity. He discusses similar efforts in predicting additional toxicity endpoints as well as approaches to elucidating adverse outcome pathways for chemical and medical device toxicities using biomedical knowledge graphs.

An Introduction to Precision Fermentation: Application and Challenges

Hosted by: SOT Biotechnology and Food Safety Specialty Sections
  • Vincent Sewalt, PhD, Head of Scientific & Public Affairs, International Flavors & Fragrances
  • Alex Eapen, PhD, DABT, Director, R&D Scientific & Regulatory Affairs, Cargill
  • Adam Leman, PhD, Lead Scientist, Fermentation, Good Food Institute
Precision fermentation is a rapidly emerging technology that promises to revolutionize various industries, from food and beverages to pharmaceuticals and biotechnology. This webinar provides an in-depth exploration of the science behind precision fermentation, the techno-economic challenges faced by this innovative approach, and the regulatory and safety hurdles that must be navigated for its successful integration into the global market. Furthermore, it examines the sustainability outlook and potential challenges associated with implementing precision fermentation on a large scale.

NCAC-SOT and CFSAN Joint Fall 2023 Symposium: Applied Toxicology and Risk Assessment

Hosted by: SOT National Capital Area Regional Chapter and the US FDA Center for Food Safety and Applied Nutrition
This day-long symposium features a keynote by Suzy Fitzpatrick, PhD, DABT, ERT, Senior Advisor for Toxicology, US Food & Drug Administration Human Foods Program, and three sessions with nine invited speakers.

Overview of the US EPA Toxics Release Inventory Toxics Tracker

Hosted by: SOT Sustainable Chemicals through Contemporary Toxicology Specialty Section
  • Christina Guthrie, MS, Lead Environmental Protection Specialist, US EPA Toxics Release Inventory Program
  • Charlotte Snyder, MS, Environmental Protection Specialist, US EPA Toxics Release Inventory Program
The US EPA TRI Toxics Tracker allows one to access nationwide Toxics Release Inventory (TRI) data from the past 10 years and to easily explore it by geography, facility, industry, chemical, or specific data elements. This webinar provides information about this tool and answers questions about how it works and its utility to those working in sustainable chemistry, alternatives assessment, and related fields. This webinar presents an overview of the tracker and its utility and expands on the Environmental Justice and Risk Analysis section of the tool.

A Connectivity Mapping (CMap)–Based Assessment of Butylated Hydroxytoluene for Endocrine Disruption

Hosted by: SOT Risk Assessment Specialty Section
Speaker: Nadira DeAbrew, PhD, Group Scientist, Procter & Gamble
Butylated hydroxytoluene (BHT) is a synthetic antioxidant widely used in many industrial sectors. BHT is a well-studied compound for which there are many favorable regulatory decisions. However, a recent opinion by the French Agency for Food, Environmental and Occupational Health and Safety (ANSES) hypothesizes a role for BHT in endocrine disruption (ANSES 2021). This opinion is based on observations in mostly rat studies where changes to thyroid physiology are observed. Enzymatic induction of Cytochrome P450–mediated thyroid hormone catabolism has been proposed as a mechanism for these observations; however, a causal relationship has not been proven. Other evidence proposed in the document includes a read-across argument to butylated hydroxyanisole (BHA), another Community Rolling Action Plan (CoRAP)–listed substance with endocrine disruption concerns.
We tested the hypothesis that BHT is an endocrine disruptor by using a next-generation risk assessment method. Four different cell lines (A549, HCC1428, HepG2, and MCF7) were treated with BHT and a series of BHT analogs at five different concentrations. RNA was isolated from cell extracts and run on the L1000 gene array platform. A toxicogenomics-based assessment was performed by comparing unique genomic signature of BHT to a large external database containing signatures of other compounds (including many known endocrine disruptors) to identify if any endocrine disruption–related modes of action (MOAs) are prevalent among BHT and other compounds with similar genomic signatures. In addition, we performed a toxicogenomics-based structure activity relationship assessment of BHT and a series of structurally similar analogs to understand if endocrine disruption is a relevant MOA for chemicals that are considered suitable analogs to BHT using the Procter & Gamble read-across framework (Wu et al. 2010). Neither BHT nor any of its analogs connected to compounds that had endocrine activity for estrogens, androgens, thyroid, or steroidogenesis.

All the Ways You Can Evaluate Lead Risks: My Pathway from Molecular Biology to Toxicology and Risk Assessment

Hosted by: SOT Women in Toxicology Special Interest Group and Metals Specialty Section
Speaker: Barbara Beck, PhD, DABT, ERT, ATS, AAAS Fellow, Principal, Gradient
Lead (Pb) is a multiple media contaminant. Multiple agencies have programs to limit Pb exposure in different media to permissible levels. This talk describes the scientific basis of four approaches for managing such exposures to lead (US FDA IRL, US EPA Superfund, US EPA dust clearance level, and CA OEHHA prop 65) and will compare approaches in terms of differences in population(s) of interest; critical endpoints; risk targets; exposure methodology; and description of uncertainty and variability.
Dr. Beck also provides a summary of her circuitous path from molecular biology and microbiology at Tufts School of Biomedical Sciences to risk assessment, toxicology, and consulting. She takes you through her career from her PhD thesis, "Study on the Relationship between Three Murein Hydrolases and Cell Division in E. coli,” to winning the WIT Smith and Hook Distinguished Service and Metals Career Achievement Awards.

A Machine Learning Model for PFAS Toxicokinetic Half-Lives: Enhancing Machine Learning with Biologically Relevant Descriptors

Hosted by: SOT Biological Modeling Specialty Section
Speaker: John Wambaugh, PhD, Research Physical Scientist, US EPA
Per- and polyfluoro-alkyl substances (PFAS) are a large and diverse class of organic chemicals. PFAS are commonly found in human tissues. While toxicokinetic (TK) data are available for a few commonly occurring PFAS, many hundreds more have been detected in the environment. TK half-life (half-life) is the amount of time needed for 50% of the chemical to be eliminated from the body. Half-life is used to extrapolate toxicological effects observed in animal species and to understand human exposure. Some PFAS have been noted as having long half-life (several years in humans). Widespread PFAS exposure from the environment and long half-lives result in the potential for bioaccumulation. Typical extrapolation methods for TK parameters of PFAS are unreliable between species and chemicals.
As an alternative, we used a method of random forests to construct a machine learning (ML) model for half-life. We balanced model performance with simplicity to create a parsimonious model. Given the limited training data (11 compounds across four species and two sexes), we only aimed to classify half-life into four broad categories (fast, moderate, slow, very slow) according to compound, species, and sex. We use the median training data in each bin as the predicted half-life. This new ML model for PFAS half-life means that TK predictions can now be made for ~4000 PFAS with no other data. Because an ML model could not be built for volume of distribution (Vd), we chose to use the median dataset value of Vd= 0.201 L/kg for all PFAS and species. Model building scripts and predictions are available online. An upcoming version of R package “httk” will include the ML predictions. The majority (56%) of PFAS were predicted to be in the longest half-life category for humans regardless of sex. Chemicals with a longer half-life may bioaccumulate and thus might warrant closer scrutiny.

The Modernization of Cosmetics Regulation Act and Confirming Cosmetic Safety

Hosted by: SOT Regulatory and Safety Evaluation Specialty Section
  • Kim Norman, PhD, DABT, ERT, Senior Director of Toxicology, Personal Care Products Council
  • Lauren Brown, DABT, MS, Senior Scientist, ToxStrategies, LLC
In December 2022, the Modernization of Cosmetics Regulation Act (MoCRA) was passed. This is the most substantial overhaul to the regulation of cosmetic ingredients and products in the United States in almost 85 years. Several major MoCRA provisions have statutory dates for implementation by the US FDA at the end of 2023.

National Capital Area and North Carolina Joint Trainee Presentations

Hosted by: SOT National Capital Area and North Carolina Regional Chapters
  • Paul M. Kruse, Postdoctoral Fellow, US EPA
    “A Cheminformatics Workflow for Higher-Throughput Modeling of Chemical Exposures from Biosolids”
  • Kevin Schichlein, PhD student, University of North Carolina at Chapel Hill
    “Aerosolized Vitamin D Attenuates Ozone-Induced Inflammation and Immune Dysfunction”
  • Sarah-Marie Alam El Din, PhD student, Johns Hopkins University Bloomberg School of Public Health
    “The Use of Single Cell Inductively Coupled Plasma Mass Spectrometry for the Detection of Metal Nanoparticles in Electronic Cigarette Condensate”
  • Michelle Fiamingo, Graduate Research Assistant, University of North Carolina at Chapel Hill and US EPA
    “Depleted Living Conditions and High Ambient Temperatures Worsen Cardiovascular and Autonomic Dysregulation in C57BL/6 Mice”

My Career in Toxicology: Research on Toxic Chemical Exposures and Medical Countermeasures

Hosted by: SOT Association of Scientists of Indian Origin Special Interest Group
Speaker: Neera Tewari-Singh, PhD, Assistant Professor, Michigan State University
ASIO member and Assistant Professor of pharmacology and toxicology at Michigan State University Dr. Neera Tewari-Singh shares her journey in toxicology and the research she has dedicated her life to. Her doctoral research background was in plant biotechnology; however, her early postdoctoral research led to an interest in developing effective medical countermeasures to treat injuries and diseases in humans arising from mass casualty scenarios involving chemical threat exposures.
Chemical emergencies pose a serious threat to the health and survival of the human population. Chemical substances that can be easily available, synthesized, and whose toxic properties can kill, incapacitate, or cause devastating injuries to human beings can cause emergencies due to their use in terrorism events, warfare, or industrial accidents. The main categories of chemical agents used as weapons include nerve agents, vesicating agents, choking agents, blood agents, and toxic industrial chemicals/toxic industrial materials (TICs/TIMs). Due to evolving technologies, increases in industrialization, easy access, and a lack of global monitoring, TICs and TIMs are emerging threats that can lead to chemical emergencies.
Dr. Tewari-Singh’s lab is employing cutting-edge technologies that can reveal more precise molecular targets for medical intervention which might be highly useful to develop effective countermeasures against toxicity from chemical exposures.

Integrating Machine Learning and Quantitative Structure Activity Relationships Modeling Approaches to Develop AI-Assisted Interactive Physiologically Based Pharmacokinetic Modeling Web Dashboard

Hosted by: SOT Risk Assessment and Biological Modeling Specialty Sections and SOT American Association of Chinese in Toxicology Special Interest Group
  • Zhoumeng Lin, PhD, Associate Professor, University of Florida
  • Wei-Chun Chou, PhD, Research Assistant Professor, University of Florida
Physiologically based pharmacokinetic (PBPK) and quantitative structure-activity relationship (QSAR) models are useful tools in the assessment of pharmacokinetics/toxicokinetics, toxicities, and health risks of environmental chemicals, drugs, and nanoparticles in animals and humans. Machine learning and artificial intelligence (AI) approaches have greatly advanced many scientific disciplines, including toxicology and risk assessment. This webinar introduces representative applications of machine learning and AI approaches in different areas of toxicological sciences, including prediction of absorption, distribution, metabolism, and excretion (ADME) properties of drugs, QSAR modeling for toxicity prediction of environmental chemicals, PBPK model development for nanoparticles, and toxicological databases relevant to these applications.