Toxicology Flashcards
Forensic medecine and toxicology is
cross between medecine and science that deals with criminal cases of poisoning. Death by poisoning vs by natural causes.
Ecotoxicity is
hebicides and various products put into environment
Daffodils is
plant contain toxins (Galanthamine and lycorine) & calcium oxalate
Galanthamine action
interferes with the action of acythylcholinesterase (to breakdown Ach)
Organophosphate
Amaryllis contain
taxine (toxic)
nightshade plant contain
deathly level of atropine
Ricin effect
disrupts protein synthesis (similar to diphteria toxin) –> death of cells
When things are discard into landfill it end up:
Soil
Air
Water
Smaller particles reach
distal alveoli (phagocytosed by alveolar macrophages <2um) or Absorbed in bloodstream if <100um
Toxicology is
study of adverse responses causes by chemical/physical agents
Acute toxicity is
agent that can cause death form eating one time
Chronic toxicity is
eating regularly over a long period of time with consequences
Example of acute and chronic toxicity:
Ethanol
Arsenic
When looking to a toxin, we evaluate:
Lethal margin of safety (LD1 compared to ED99)
Shape of the curve (slow rise vs dramatic rise)
Presence of threshold dose
NOAEL is
No effective observed level - the highest point at which there was no observed toxic or adverse effect
LOAEL is
Lowest point at which there was an observed toxic or adverse effect
Cohort study is
Study of individuals with EXPOSURE to a chemical compare to another one without
2 types: Prospective and retrospective
Case control study is
Study group with a problem and compare to others (compare if their is a difference in exposure)
Cross-sectional study is
take data and comparing and correlating data on exposure and disease.
Odd ratio is
ratio between the risk of disease in a case-control study for an exposed group to an unexposed group
Standardized mortality ratio (SMR) is
relative risk of death comparing exposed to a non-exposed group.
Relative risk (RR) is
ratio expressing the occurence of disease in an exposed population to an unexposed popuation (%)
Factor that could invalidate a study:
Bias
Confounding (forget to include important aspect in the study)
Chance
Types of bias:
Selection bias
Information bias
Recall bias
Lead affects
Nervous system
Decrease function in vitamin D metabolism
Hemoglobin synthesis
Erythrocyte protoporphyrin (heme production inhibited or lack of iron)
Developmental toxicity (no hearing growth, brain development)
Methylated mercury become methylated by
come from volcanoes/ rock and become methylated in the water and soil.
Grasshopper effect is
air currents move volatile contaminants north every year.
Organochlorines act one
example:
Voltage-gated sodium channel
DDT (insecticide)
Why insect more vulnerable to organochlorines?
Because staying open longer than mammalian channels (insect die by convulsion)
Lindane is
act one
Insecticide use in tx lice.
GABA
Pyrethroids is
act one
insecticide
prolong opening of voltage-gated ion channels
Organophosphates is
act on
category of insecticide
interferes with acetylcholinesterase at the cholinergic synapse (Blocking the action of the enzyme –> respiratory failure)
Malathion
difference with others
insecticide from the category of organophosphate
can be metabolized by mammals (least toxic)
