GI Bio Flashcards
Medication that improves survival in metastatic colon cancer?
Mechanism?
Mutation that predicts a poor response?
Cetuximab
inhibits EGFR
Presence of KRAS-activating mutations predict poor response (restricted to wildtype KRAS)
Pathway that plays a key role in intestinal cell proliferation?
WNT pathway
Name the syndrome associated with mutations in this gene:
MLH1
Hereditary non-polyposis colon cancer (Lynch Syndrome)
Mutations in the following develop colon cancer through chromosomal instability pathway?
APC
KRAS
TP53
Name the syndrome associated with mutations in this gene:
PTEN
Cowden syndrome
Name the syndrome associated with mutations in this gene:
SMAD4
Juvenile polyposis
Name the syndrome associated with mutations in this gene:
BMPR1A
Juvenile polyposis
Name the syndrome associated with mutations in this gene:
CDH1
Hereditary diffuse gastric cancer
Name the syndrome associated with mutations in this gene:
LKB1/STK11
Peutz-Jager syndrome
Name the syndrome associated with mutations in this gene:
Menin
MEN1
Sporadic unstable microsatellite colon cancer is associated with?
CPG island hypermethylation
Protein product of CDH1?
E-cadherin
Name the syndrome associated with mutations in this gene:
MSH2
hereditary non-polyposis colorectal cancer (HNPCC) AKA Lynch syndrome
Name the syndrome associated with mutations in this gene:
APC
Type of mutation?
APC function?
Familial adenomatous polyposis; Gardner syndrome
Germline mutation
Tumor suppressor gene
Role of Peyer’s patches?
M-cell function?
Immune surveillance of intestines
Phagocytosis and endocytosis
This protects immunoglobulins from gastric acid and luminal proteases?
Expressed by?
Polymeric Ig receptor
Basaolateral membrane of intestinal epithelial cells
The layer of the intestinal wall with the majority of inflammatory cells?
Lamina propria
Pathobiont?
Organism that has a potential to cause disease under certain circumstances (c diff)
Somatostatin is produced by?
Main role? Mechanism?
Gastric Antral D cells
Increase gastric pH.
Paracrine effect on parietal cells to inhibit gastric acid secretion
Prebiotic?
Pharmabiotic?
Indigestible food that selectively induces the growth of beneficial bacteria
Any biologic product obtained from the human microbiota and has biologic activity
Bacterial phyla that contribute 90+ percent of the species in the distal bowel?
Bacteroidetes, Firmicutes
Operational taxonomic unit stratifies microbes according to?
16S rRNA sequence Homology
Form of communication between related bacteria that senses the diversity and density of bacteria in the local environment, regulating gene expression?
Quorum sensing
Meissner vs Auerbach plexus?
Sunmucosal plexus versus myenteric plexus
Secretin - secreted by? Stimulates?
Duodenal S-cells; pancreatic fluid and bicarbonate secretion
Hypersecretion of VIP from a pancreatic neuroendocrine tumor – results in this syndrome?
Other features?
Verner–Morrison syndrome
WDHA - Watery diarrhea; hypokalemia;
achlorhydra (hyperchloremic metabolic acidosis)
Also:
Hypercalcemia;
Facial flushing
Overproduction of somatostatin results in? Usual culprit?
Steatorrhea and cholelithiasis
Duodenal tumor
The level of Motilin follows a similar pattern to?
Motilin is secreted from? Under what circumstances?
Function?
Migratory motor complexes
Intestinal epithelium; fasting conditions
Stimulates insulin release and gastric emptying
Hormone secreted from adipocytes? Main function?
Secreted from?
Leptin; decreased food intake
Stomach
Foveolar hyperplasia and dilated cystic glands are the pathologic feature of?
Endoscopic findings?
Mechanism?
Ménétrier’s Disease
Irregular hypertrophic folds in the stomach
Increased transforming growth factor alpha -> binds epidermal growth factor receptor -> mucosal gland hyperplasia
Gastrointestinal stromal tumor‘s are usually do to enhanced signaling in this pathway?
C-kit and platelet-derived growth factor receptor
Amylin - synthesized by? Function?
Pancreatic beta cells
Suppresses glucagon secretion, delayed gastric emptying, induces satiety
Difference in function between leptin and amylin?
Both induce satiety but amylin delays gastric emptying
Ghrelin nickname? Function?
“Hunger hormone“ – increase his food intake
Hormones that suppress food intake?
Leptin, peptide YY, Amylin Lin, GLP-1
Hormones that delayed gastric emptying?
CCK, secretary, peptide YY
Function of VIP?
Vasodilation, gastric acid inhibition, smooth muscle relaxation, and increased epithelial secretion,
Function of Pancreatic polypeptide?
Inhibits pancreatic enzyme secretion
Function of CCK?
Pancreatic enzyme secretion, gallbladder contraction, Sphincter of Oddi relaxation
