Gastric cancer and IBD Flashcards
What are the 2 secretory cell types in gastric gland, and which produces acids?
1) Parietal cells (P cells) are the type that secrete acid by pumping protons into the gastric lumen.
2) Non-parietal mucosal epithelial cells secrete bicarbonate mucus that is protective
What are the 2 types of drugs that inhibit gastric acid secretion?
1) H2 antagonists
2) Proton-pump inhibitor (PPI)
How does Helicobacter pylori damage the stomach?
Invades the mucus lining cells and secretes urease (makes NH3 and neutralizes environment).
Can directly damage the epithelium and further damage via immune response.
Inflammatory damage results in mucosal atrophy. Acid further damages atrophic mucosa.
What is intestinal metaplasia?
Change of cell morphology to something that looks more small intestinal (white goblet cells).
Describe an experiment testing which cell type the metaplastic gastric epithelial cells originated from.
Replace bone marrow w/ marrow from β-gal mouse. Infect with H. pylori and wait for metaplasia.
Describe 2 types of inflammatory bowel diseases.
1) Crohn’s disease: transmural, thickening, multi-organ involvement
2) Ulcerative colitis: mucosal, thinning
Diagnosed via anti-inflammatory/immunosuppression and/or surgery.
List 3 modes of the mechanisms of glucocorticoid actions.
1) Binds to glucocorticoid receptor and acts as transcription factor.
2) Can also act as transcriptional repressor by binding and inhibiting the NF-kB complex.
3) Acts on protein folding and activation of anti-inflammatory proteins.
What are glucocorticoid target cells, and how do they respond?
Immune: Downregulate pro-inflammatory factors for mostly NF-kB. Immune suppression.
Metabolic: Liver, increase glucose generation from amino acids and lipids. Adipose tissues, lipolysis. Bone, inhibit formation (osteoblasts) and activate lysis (osteoclasts)
Cancer cells: Pro-apoptotic, anti-angiogenesis, not all cancer cells respond
List 2 categories of molecules that can be targeted in IBDs, and 1 example of each.
1) Cytokines: TNFα
2) Leukocyte trafficking: Integrin inhibitor
A 29 year old visited the clinic complaining of stomach discomfort for 6 months. Gastric endoscopy and biopsy shows gastric lesions as presented. Choose the best combination of correct statements.
a. Urease test can help determine the cause of symptoms.
b. These cells may be of bone marrow origin.
c. This lesion is often accompanied by atrophic epithelium.
d. Glucocorticoids must be used to relieve the inflammation.
a. True, urease is secreted by H. pylori
b. True
c. True, atrophic (reabsorption and breakdown of tissues, usually involving apoptosis)
d. False
What stimulates parietal cell secretion (P cells)?
Histamines. Secreted by ECL cells.
Parietal cells
Epithelial cells that secrete hydrochloric acid (HCl) and intrinsic factor. These cells are located in the gastric glands found in the lining of the fundus and in the cardia of the stomach.
Peptic ulcer
Mucosal layer gets damaged and bleeding occurs. Diagnosed via gastric endoscopy.
Can be caused by H. pylori, non-steroidal anti-inflammatory drugs (NSAIDs), and stress
