Toxicology
This section covers the key components of toxicology
Biochemical Theory and Pathways
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Toxicokinetics: How the body handles toxins (ADME processes)
- Absorption: Entry into the body
- Distribution: Transport to tissues
- Metabolism: Chemical alteration (detoxification or bioactivation)
- Excretion: Elimination from the body
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Mechanisms of Toxicity
- Cellular damage, enzyme inhibition, oxidative stress, etc
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Target Organs
- Specific organs are more vulnerable to certain toxins
- Liver, kidneys, brain, lungs, heart
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Dose-Response Relationship
- Higher doses generally cause more severe effects
Laboratory Test Procedures
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Analytical Principles
- Immunoassays: Antibody-antigen binding for screening
- Chromatography: Separates compounds
- Mass Spectrometry: Identifies compounds by mass
- Atomic Absorption Spectrometry: Measures light absorption by atoms
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Common Assays
- Drugs of abuse screens
- Alcohol levels
- Heavy metal analysis
- Specific drug assays
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Special Precautions
- Chain of custody, proper storage, quality control
Test Result Interpretation
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Quantitative vs. Qualitative Results
- Qualitative: Positive/negative
- Quantitative: Numerical concentration
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Cutoff Values
- Threshold for positive results
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Reference Intervals
- Limited in toxicology (therapeutic ranges for some drugs)
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Analytical Considerations
- Cross-reactivity, interfering substances
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Clinical Correlation
- Patient history, symptoms, medications