Presentation on theme: "What Do Toxicologists Do?"— Presentation transcript:
1 What Do Toxicologists Do? Most Toxicologists work to assess and understand how chemicals affect living systemsDevelop mechanistic understanding of effectsEnsure safer chemical productsDevelop safer drugs & medicinesDetermine risks from chemical exposuresDevelop treatments for chemical exposuresEnsure a safe food and water supplyForensics
2 Toxicology is an applied science with many areas of specialization Images from Gray’s AnatomyImages from webelements.comImage from Molecular Cell BiologyWhat is so great about toxicology is that you are specialized but diverse all at the same time!!Introduce the concept of dose w/ tetrodotoxin (fugu)
3 Who are Toxicologists?Toxicology involves integration of information frommany different areas of expertise. People working intoxicology can also be called:BiochemistsChemistsPathologistsCancer ResearchersVeterinariansMedical DoctorsCell and Molecular BiologistsEngineersMathematiciansStatisticiansLab TechniciansAnimal Care Providers
4 What are major areas of specialization in toxicology? Mechanistic toxicology (basic biology and chemistry)Descriptive toxicology (testing)Regulatory toxicology (rule making and compliance)Risk assessment (modeling)Translational and clinical (applying basic research to patient care)
5 Mechanistic Toxicology Focuses on howChemicals produce adverse effectsBiological systems protect themselves against adverse effectsInvolvesCellular and Molecular BiologyChemistry, often xenobiotic metabolismXenobiotic: a chemical that is foreign to the organism
6 Mechanistic Toxicology Chemical research in toxicology usually investigates metabolic transformations of drugs or potentially hazardous chemicalsHow persistent is a chemical in the body?Are metabolic products toxic?Do test animals exhibit the same results as humans or other species of concern?
7 Descriptive Toxicology Typically involves toxicity testingBroad spectrum of responses reflects toxicityFunctional effects, such as immunological responsesGrowth inhibitionReproductive impairmentIncrease in cancer incidenceMortality
8 Descriptive Toxicology Toxicity Testing Assesses the concentration-dependent hazard a chemical may presentHuman healthNatural populationsResults typically applied toApproval of product useRegulating allowable concentrations in the environment.
9 Descriptive Toxicology Types of toxicity testingIn vitro (test tube)—useful in detecting potential biochemical and genetic effectsUse model systems (bacteria, cultured animal cells, DNA interactions)In vivo (animal)—are essential for detecting health effectsAcute, chronic, multi-generationExperimental animals may be treated with high doses over a lifetime to evaluate potential to cause cancerIn silico (computer-based)—biological experiments conducted by computer models; these depend on data previously collected in other experimentsCompletion of all toxicity tests may take five or six years and is very costly
10 Descriptive Toxicology Toxicity Testing Molecular and cellular studies in toxicology often supplement toxicity testing results to help ascertain chemical hazard. They often unravel complex processes that underlie an adverse response.Use of toxicants can help determine the function of proteins in complex networks.
11 Descriptive Toxicology What private and public sectors invest in toxicity testing that aims to protect human health?Chemical ManufacturersPharmaceutical IndustryUS Federal Agencies and ProgramsNational Toxicology Program (NTP)Environmental Protection Agency (EPA)National Institute of Environmental Health Sciences (NIEHS)Food and Drug Administration (FDA)State and Local Governmental Bodies
12 Regulatory Toxicology Setting rules and assuring complianceProduct registrationAllowable concentrations in food or environmental mediaTechnical and legal issues may require negotiation and gathering of new informationRisk and safety are estimated by total weight of evidenceToxicity evidence is the basis, but often rules are modified by political, legal considerations, as well a technical feasibility
13 Regulatory Toxicology Risk Assessment Is the mathematical modeling processthat yields estimates for safe orallowable chemical concentrationsHazard identificationDose-response assessmentExposure characterizationIdentify unique effects of chemical mixturesRisk assessmentRisk characterizationRight to know and understandUncertainty characterization
14 TranslationalTranslational science is the application of biomedical research and drug development to efficiently use a promising drug in the right patient circumstances and assess its efficacy in the human using appropriate indicators such as biomarkers.Scientists work in multidisciplinary teams involving basic researchers, clinicians, patient care providers, regulators, and ethics boards.Basic scientists provide new tools for use in patients and for assessment of their impact, and clinical researchers make novel observations about the nature and progression of disease that can lead to further basic research.