31 - Smoking

Question 1

How do carcinogens in cigarettes cause carcinoma

Answer 1

• Metabolic activation by “DNA adduct” (covalently bonded)
• Direct DNA damage (oncogenic mutations)

Question 2

Gene mutations in tobacco induced cancer

Answer 2

• Inactivation of tumour suppressor genes (e.g. p53)
• Activation of oncogenes
• Gene silencing by promotor methylation

Question 3

Carcinoma caused by smoking

Answer 3

• Larynx
• Eosophagus
• Trachea
• Lung
• Myeloid leukemia
• Stomach
• Pancreas
• Kidney

Question 4

3 factors that contribute to thrombosis (Virchow’s Triad)

Answer 4

• Endothelial injury
• Hyper coagulability
• Abnormal blood flow

Question 5

CVD risks

Answer 5

• Development of atherosclerotic changes
• Induction of hypercoagulable state (acute thrombosis)
• Glucose intolerance
• Diabetes
• Stroke
• Caused even at low dose (second hand smoke)

Question 6

Pulmonary disease caused by smoking

Answer 6

• Chronic bronchitis
• Chronic obstructive pulmonary disease (includes emphysema)
• Exacerbation of asthma

Question 7

Chronic bronchitis

Answer 7

• Cough and sputum most days for at least 3 months
  in at least two years
• In half of heavy smokers
• Symptoms decrease within 1-2 months of cessation

Question 8

COPD (Chronic obstructive pulmonary disease)

Answer 8

• Air flow limitation that is not reversible
• Obstructive bronchiolitis
• Emphysema

Question 9

COPD pathogenesis

Answer 9

• Oxidative stress
• Protease-antiprotease imbalance (free radicals in cigarette smoke, chronic inflammation, genetic)

Question 10

Effect of smoking on developing foetus

Answer 10

• Pre term delivery (immature) due to contractile sensitivity
• Intra uterine growth restriction (more prone to developmental defects) due to toxin substances found in placenta and cord
• Increased risk of premature rupture of membranes

Question 11

Other reproductive health concerns due to smoking

Answer 11

• Reduced sperm quality
• Diminished oviduct function
• Placenta previa
• Placental abruption