1. Introduction Flashcards

1
Q

Define toxicology.

A

The study of the adverse effects of xenobiotics on biological and ecological systems.

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2
Q

Define Xenobiotic.

A

Any substance that is foreign to a biological system

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3
Q

What’s the difference between a toxicant and a toxin?

A

Toxicant: a chemical that is produced by man and after introduction into the environment produces harmful effects.
Toxin: a harmful substance produced within a cell or an organism, e.g., snake venom.

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4
Q

How are toxic substances classified? give examples

A

Toxic substances can be classified according to why the chemicals exist:

  • Chemical warfare agents
  • Pesticides
  • Environmental pollutants
  • Household poisons
  • Drugs
  • Food additives
  • Cosmetics
  • Industrial chemicals
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5
Q

Give examples of plants that produce toxins.

A
  1. Star of Foxglove
  2. Belladonna
  3. Poison ivy
  4. Poison oak
  5. Yew
  6. Oleander
  7. Wisteria
  8. Hemlock
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6
Q

Can natural substances such as plants be toxicants? Give examples.

A

Yes, just because it is natural, it doesn’t mean it can’t be toxic.
Ex: star of foxglove -> Digoxin
Belladonna -> atropine
Yew -> Taxol

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7
Q

Describe the differnece between toxicology and pharmacology.

A

Toxicology: Undesired effects of therapeutic agents.

  • Actions of poisons / toxins that would not be used as therapeutic agents
  • Effects of chemicals in/on the environment - indirect effects on human health

Pharmacology: Desired effects of therapeutic agents.

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8
Q

What are the branches of toxicology?

A
  1. Clinical Toxicology (hospital setting)
  2. Forensic Toxicology (Medical Examiner’s office)
  3. Industrial Toxicology
  4. Environmental Toxicology (Government, University)
  5. Biochemical and Molecular Toxicology (University)
  6. Product Development Toxicology (Corporate setting)
  7. Regulatory Toxicology (industry and government settings)
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9
Q

What is the distribution of chemicals in commerce in order from biggest to smallest?

A
1. Industrial
~80,000 on TSCA (toxic substances
control act) 
Inventory
No specific data requirements for
PMNs (pre-manufacture notice)
  1. Pesticides
    ~2000 Active Ingredients (AI)
    FIFRA requires data (Federal Insecticide, Fungicide, and Rodenticide Act)
  2. Drugs, Cosmetics, Food Additives
    ~2,000 AI
    Federal Food, Drug, and Cosmetic Act requires data
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10
Q

What is the purpose of mechanistic toxicology? Who mainly researches it?

A

To identify and understand cellular and molecular mechanisms by which chemicals exert toxic effects on organisms.
Done by academic research.

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11
Q

What is the purpose of regulatory toxicology?

Who mainly researches it?

A

Assess risk prior to marketing HC, FDA, EPA, OSHA.

Mainly researched by the government.

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12
Q

What is descriptive toxicology?

Who mainly researches it?

A

Toxicity testing, Safety evaluation, and Regulatory requirements.
It is mainly researched by the industry.

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13
Q

Who is the father of Chinese medicine? What did he do?

A
  • Emperor Shen Nung

- Wrote Pen Ts’ao - the Great Herbal or Chinese Materia Medica

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14
Q

What is Ebers papyrus?

A

Ebers papyrus, Egyptian compilation of medical texts dated about 1550 bc, one of the oldest known medical works.

  • recognizes many poisons such as:
  • hemlock
  • aconite (helmet flower)
  • Chinese arrow poison,
  • opium
  • heavy metals (lead, copper and antimony)
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15
Q

Explain the history of pharmacology that took place in Rome.

A

King Mithridates VI (Rome, 132–63 BC)

  • did acute toxicity experiments on accused criminals
  • claimed to have discovered a mixture of antidotes against all poisons
  • treated himself with a mixture of 36 such chemicals
  • Mithridatic = antidotal or protective mixture
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16
Q

Explain the history of pharmacology that took place in Medieval Spain.

A

Maimonides wrote Poisons and Their Antidotes (1198):

  • First volume to systematically describe treatments for poisoning from insects, snakes and mad dogs
  • Noted that milk, butter and cream could delay intestinal absorption, I.e., bioavailability
17
Q

Explain the history of pharmacology that took place in France/Italy.

A

Catherine de Medici (Italy/France 1519-1589) obtained direct evidence to identify most effective poisons:

  • carefully noted: rapidity of response (onset of action)
  • effectiveness of compound (potency)
  • degree of response of body parts (specificity)
  • complaints of victim (clinical signs and symptoms)
18
Q

Who is the father of modern toxicology? What were his contributions?

A

Paracelsus
Quote: “All substances are poisons; there is none which is not a poison; the right dose differentiates a poison from a remedy”
- Articulation of the concept of the dose response relationship
- Toxicon, the primary toxic substance, is a chemical entity and not a mixture.

19
Q

What were the first cases of occupational toxicology and who discovered them?

A
  • Ellenberg, 1480: warns of toxicity of mercury and lead in goldsmithing
  • Pott, 1775: recognizes that soot causes scrotal cancer in chimney sweeps; first reported action of polyaromatic hydrocarbon carcinogenicity
20
Q

Who were the pioneers in experimental toxicology? What did they do?

A
  • Orfila (Spanish/French), 1818 – First to use autopsy material and chemical analysis systematically as legal proof of poisoning
  • Magendie (French), ~1830 – First to study mechanism of action of poisons such as strychnine
  • Bernard (French), ~1850 – Demonstrates how the South American arrow poison (curare) works as well as the mechanism of action of carbon monoxide
21
Q

How did toxicology evolve in the 20th century?

A
  • Rapid development of organic chemistry; thousands of new chemicals
  • Misuse of drugs and elixirs leads to numerous toxic reactions
  • Chemicals are developed for warfare
  • Development of pesticides/insecticides
  • Creation of governmental regulatory bodies, e.g. FDA (1938)
  • Recognition of Toxicology as a field with national
    societies and numerous scientific publications
22
Q

How did toxicology evolve in the 21st century?

A
  • Environmental Toxicology
  • Toxicogenomics
  • Epigenotoxicology
  • Trangenerational Toxicology
  • Computational Toxicology
  • Predictive Toxicology
  • NAMS (new approach methodologies)
23
Q

What are the branches of toxicology?

A
  1. Clinical Toxicology (hospital setting)
  2. Forensic Toxicology (Medical Examiner’s office)
  3. Industrial Toxicology
  4. Environmental Toxicology (Government, University)
  5. Biochemical and Molecular Toxicology (University)
  6. Product Development Toxicology (Corporate setting)
  7. Regulatory Toxicology (industry and government settings)