BIOL 0510 Lecture Notes - Lecture 12: Helicobacter Pylori, Peptic Ulcer, Stomach Cancer
7 Nov 2016
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Ulcers caused by lifestile (stress): diet, alcohol, drugs. Lifestyle change was antacids or surgery as only solution. 1970s-1980s marshall knew that antibiotics cured peptic ulcers. Also know that h. pylori was associated with 100% ulcers. First: microorganism must be found in all organisms suffering from the disease but should not be found in healthy organisms. Marshall drank h. pylori --> developed gastritis. Most gastric ulcer patients have h. pylori infection. 80% of infected people are asymptomatic (>50% of world, 10-50% of us) Infection carries 10-20% chance of developing ulcers and 1-2% lifetime risk of gastric cancer. 100 other bacteria inhabit the stomach: microbiome. Infection: growth of a microbe typically not present in the host (not necessarily pathogenic) Parasites/pathogens: organisms living on/in host organisms that cause damage. Opportunistic pathogen: causes disease only in absence of host defense. Virulence: relative ability of pathogen to cause disease: risk factors for infection. Youth and advanced age: host-parasite interactions.
