Lecture 4

Question 1

What is toxicodynamics?

Answer 1

• toxicodynamics refers to the molecular, biochemical, and physiological effects of toxicants or their metabolites in biological systems
• these effects are result of the interaction of the biologically effective dose of the ultimate (active) form of the toxicant with a molecular target

(what a chemical does when it gets to its targeted location)

Question 2

What are some forever chemicals

Answer 2

nonstick cookware
pesticides
coolants
flame retardants
electrical insulation
pharmaceuticals

Question 3

What is a biomarker of an internal exposure?

Answer 3

A chemical or it’s metabolite that is measured in the body (e.g. DNA adducts in urine, hair mercury, etc.)

Question 4

What is a biomarker of a biological effect?

Answer 4

Any measurable biochemical, physiological, or alteration in an organism that, depending on magnitude, can be recognized as an established potential health impairment or disease (DNA adduct, polyps)

Question 5

What are some benzopyrene sources?

Answer 5

Question 6

Does the environment influence cancer?

Answer 6

New migrant populations assume the cancer incidence of their NEW environment, even in the first generation

Question 7

Explain differences in cancer risk.

Answer 7

Question 8

What are some biomarkers of risk sensitivity?

Answer 8

Question 9

Name three potential targets that can increase cancer risk.

Answer 9

endocrine disruptors
effectors of proliferation
immune suppressors

Question 10

Name four processes that can compromise toxicodynamics.

Answer 10

1. inflammation: cancer, arthritis
2. oxidative stress: all diseases
3. energy production: etiology of some neurodegenerative diseases re due to disruption in energy (ATP) production
4. intracellular calcium homeostasis: some neurodevelopmental diseases might be due to effects on it

Question 11

What is an endocrine disruptor?

Answer 11

An exogenous chemical substance or mixture, natural or synthetic, capable of interfering with the biosynthesis, storage, release, transport, and/or receptor binding of endogenous hormones, ultimately interfering with the proper functions of these hormones.

Question 12

What are some examples of Bisphenol A(BPA)?

Answer 12

• BPA has been shown to affect the reproductive systems of laboratory animals
• human health effects from BPA at low environmental exposures are unknown
• BPA found in the urine of nearly all of the people tested

Question 13

What’s the story with thalidomide?

Answer 13

Had a bunch of adverse birth effects that caused birth defects and some died. They had amelia (lacking one or more limbs), phocomelia(severe abnormalities of the limbs), and other effects(respiratory, cardiovascular, and urogenital)

the rats weren’t sensitive to it so they didn’t know before they prescribed it

Question 14

What are some critical windows of exposure in pregnancy?

Answer 14

Question 15

What is Baker’s Hypothesis for fetal basis of disease?

Answer 15

Question 16

Why have rodent models been used in assessing risk of exposure to chemicals? And what are some assumptions made?

Answer 16

short lifespan
easy to manipulate
90% of the rat genes are found in humans
similar physiology

Assumptions: an agent that causes an adverse effect in experimental animals might cause an effect in humans but also the absence of an effect in animals is not harmful to humans, all endpoints of toxicity are of potential concern

Question 17

What is risk context?

Answer 17

Individual and community behaviors that affect the way risk arises and how it may be managed.

Question 18

What is toxicity testing?

Answer 18

Relationship between chemical structure and its effect

Question 19

What are polymorphisms?

Answer 19

genetic variants