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14 Cards in this Set
- Front
- Back
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acetaminophen toxicity
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Tylenol mostly metabolised in liver by sulfation and glucuronidation. Reactive metabolite formed, detoxed by reduced by glutathione (GSH). Overdose depletes GSH, toxic metabolites accumulate.
Massive hepatic necrosis 3-5 days. |
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carbon monoxide toxicity
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Combines with Hb, >200 higher affinity for oxygen. Even less oxygen dissociates with hypoxia, compounding effect.
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cyanide toxicity
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Rapidly absorbed via bronchial mucosa and alveoli. HCN blocks cytochrome oxidase, results in diffuse cellular anoxia.
Effects within secs/mins. |
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mercury poisoning
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Hg binds covalently to sulfhydryl groups; denatures and inactivates proteins.
Inorganic: Kidneys Organic/elemental: cross BBB, neuronal necrosis. |
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lead poisoning
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(-) δ-aminolevulinic acid; ↓haeme syn., ↑RBC fragility.
Targets: bone marrow, kidneys, GI. Adults: PNS Children: CNS |
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Silicosis
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inhalation of silica (from rock, esp. quartz; mining, polishing, sandblasting, stonecutting, ceramics)
Macrophages secrete fibrogenic/chemotactic factors. Collagenous nodule coalesce into fibrous lesions in UPPER lung fields. 15-20+ years of exposure. Associated: TB, rheumatoid arthritis, pulmonary HTN, right heart failure, lung cancer, resp. impairment. |
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Asbestosis
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Macrophages secrete fibrogenic/chemotactic factors.
ASBESTOS BODIES (asbestos fibres coated in iron-protein complex) most pronounced in LOWER and subpleural lung. 10-20+ years exposure. pulmonary HTN, right heart failure, lung cancer, resp. impairment, pleural lesions. |
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Hypersensitivity pneumonitis
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Hypersensitivity to inhaled organic dusts/Ag. Acute and flu-like.
Dyspnea, dry cough fatigue. Type III (humoral) and type IV (Cell-mediated) immune mechanisms. |
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Aflatoxin B1
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Toxin due to contamination of food by fungus; metabolism yields reactive electrophilic epoxide that covalently binds to DNA, initiating tumours.
Hep B may be synergistic. |
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Acute/early radiation
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days to weeks
Cellular necrosis, rapidly proliferating cells principally effected. Nuclear change from chromatin clumping to karyorrhexis (breaking up of DNA) Swelling, vacuolisation. |
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Late/delayed radiation
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months to years
fibrosis/vascular changes; vascular sclerosis, interstitial fibrosis, atrophy of parenchymal/epithelial cells, cellular atypia. |
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Haematopoietic Syndrome
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200-500 cGy
Latency: 1-3 wks Pancytopenia, haemorrhage, infection, death in 3-6 wks. |
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Gastrointestinal Syndrome
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500-1000cGy
Latency: 1-4 days Denudation/ulceration of GI mucosa, fever, diarrhoea, death in 1-2 wks. |
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CNS/Cardiovascular Syndrome
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>1000cGy
Latency: min-hours Generalised damage to BVs, diffuse leakage of plasma, oedema, drowsiness, ataxia, convulsions, coma, hypotension, shock. Death in 1-2 days. |
