Pathology - Environmental Disease Flashcards
Polycyclic hydrocarbons…
Benzopyrene…
Nitrosamines…
Are all what?
Potent carcinogens found in cigarette smoke. Especially potent after CYP modification.
What kind of drug is nicotine?
An addictive alkaloid.
It binds to CNS receptors causing release of catecholamines.
Which cancers does smoking contribute to?
Lung. Oral. Esophagus. Pancreas. Bladder. Laryngeal.
How does smoking cause emphysema?
Inflammation caused by irritants leads to leukocyte recruitment, which leads to increased elastase activity.
Alpha-1 anti trypsin can’t keep up…
What is the legal limit for EtOH in NZ?
80 mg/dL.
Metabolic pathways for EtOH metabolism include?
3 pathways
Alcohol dehydrogenase
Microsomal ethanol oxidising system
Liver catalase
Fetal alcohol syndrome is characterised by which growth and developmental defects?
Microcephaly
Facial dysmorphology
Malformations of the brain
Malformations of the CVS and GU systems.
What is Resveratrol? What effect is associated with Resveratrol?
Resveratrol is a polyphenolic compound in red wine. In doses, which far exceed those in red wine, it is associated with extended life in animals. Sirtuin enzymes are involved.
What is non-ionizing radiation?
Radiation with longer wavelengths and lower frequencies. It does not have sufficient energy to displace bound electrons. Examples include UV, IR, radio/micro/sound waves.
What is ionizing radiation?
Radiation of short wavelength and high frequency which displaces electrons. Examples include X-Rays, gamma rays, alpha and beta particles, and high energy neutrons.
How are radiation doses measured?
Three different ways:
- The amount emitted by a source - Curies
- The dose absorbed by tissue - Grays
- The biological effect - Sievert
What are the determinants of biological effect of Ionizing Radiation?
- Rate of delivery
- Field size
- Cell proliferation
- Vascular supply of tissue
- Oxygenation of tissue
How does oxygenation of tissue affect ionizing radiation effect?
DNA damage by radiation is enhanced and effected by ROS. Poorly vascularised tissue with relative hypoxia will be less sensitive to radiation injury.
Total body Ionizing radiation doses and effects:
10 Gy?
1-2 Gy?
0.5 Gy?
10 Gy = Death, usually within 5-14 days, SB mainly affected.
1-2 Gy = Kills proliferating cells within 2-6 weeks. Lymphocytes most affected.
0.5 Gy = No effect
What kind of DNA damage occurs with ionizing radiation?
Damage done includes single base damage, single and double strand breaks (DSB), and DNA protein cross links. DSBs are the most serious.
