GI Bio

Question 1

Medication that improves survival in metastatic colon cancer?

Mechanism?

Mutation that predicts a poor response?

Answer 1

Cetuximab

inhibits EGFR

Presence of KRAS-activating mutations predict poor response (restricted to wildtype KRAS)

Question 2

Pathway that plays a key role in intestinal cell proliferation?

Answer 2

WNT pathway

Question 3

Name the syndrome associated with mutations in this gene:

MLH1

Answer 3

Hereditary non-polyposis colon cancer (Lynch Syndrome)

Question 4

Mutations in the following develop colon cancer through chromosomal instability pathway?

Answer 4

APC
KRAS
TP53

Question 5

Name the syndrome associated with mutations in this gene:

PTEN

Answer 5

Cowden syndrome

Question 6

Name the syndrome associated with mutations in this gene:

SMAD4

Answer 6

Juvenile polyposis

Question 7

Name the syndrome associated with mutations in this gene:

BMPR1A

Answer 7

Juvenile polyposis

Question 8

Name the syndrome associated with mutations in this gene:

CDH1

Answer 8

Hereditary diffuse gastric cancer

Question 9

Name the syndrome associated with mutations in this gene:

LKB1/STK11

Answer 9

Peutz-Jager syndrome

Question 10

Name the syndrome associated with mutations in this gene:

Menin

Answer 10

MEN1

Question 11

Sporadic unstable microsatellite colon cancer is associated with?

Answer 11

CPG island hypermethylation

Question 12

Protein product of CDH1?

Answer 12

E-cadherin

Question 13

Name the syndrome associated with mutations in this gene:

MSH2

Answer 13

hereditary non-polyposis colorectal cancer (HNPCC) AKA Lynch syndrome

Question 14

Name the syndrome associated with mutations in this gene:

APC

Type of mutation?

APC function?

Answer 14

Familial adenomatous polyposis; Gardner syndrome

Germline mutation

Tumor suppressor gene

Question 15

Role of Peyer’s patches?

M-cell function?

Answer 15

Immune surveillance of intestines

Phagocytosis and endocytosis

Question 16

This protects immunoglobulins from gastric acid and luminal proteases?

Expressed by?

Answer 16

Polymeric Ig receptor

Basaolateral membrane of intestinal epithelial cells

Question 17

The layer of the intestinal wall with the majority of inflammatory cells?

Answer 17

Lamina propria

Question 18

Pathobiont?

Answer 18

Organism that has a potential to cause disease under certain circumstances (c diff)

Question 19

Somatostatin is produced by?

Main role? Mechanism?

Answer 19

Gastric Antral D cells

Increase gastric pH.

Paracrine effect on parietal cells to inhibit gastric acid secretion

Question 20

Prebiotic?

Pharmabiotic?

Answer 20

Indigestible food that selectively induces the growth of beneficial bacteria

Any biologic product obtained from the human microbiota and has biologic activity

Question 21

Bacterial phyla that contribute 90+ percent of the species in the distal bowel?

Answer 21

Bacteroidetes, Firmicutes

Question 22

Operational taxonomic unit stratifies microbes according to?

Answer 22

16S rRNA sequence Homology

Question 23

Form of communication between related bacteria that senses the diversity and density of bacteria in the local environment, regulating gene expression?

Answer 23

Quorum sensing

Question 24

Meissner vs Auerbach plexus?

Answer 24

Sunmucosal plexus versus myenteric plexus

Question 25

Secretin - secreted by? Stimulates?

Answer 25

Duodenal S-cells; pancreatic fluid and bicarbonate secretion

Question 26

Hypersecretion of VIP from a pancreatic neuroendocrine tumor – results in this syndrome? Other features?

Answer 26

Verner–Morrison syndrome WDHA - Watery diarrhea; hypokalemia; achlorhydra (hyperchloremic metabolic acidosis) Also: Hypercalcemia; Facial flushing

Question 27

Overproduction of somatostatin results in? Usual culprit?

Answer 27

Steatorrhea and cholelithiasis Duodenal tumor

Question 28

The level of Motilin follows a similar pattern to? Motilin is secreted from? Under what circumstances? Function?

Answer 28

Migratory motor complexes Intestinal epithelium; fasting conditions Stimulates insulin release and gastric emptying

Question 29

Hormone secreted from adipocytes? Main function? Secreted from?

Answer 29

Leptin; decreased food intake Stomach

Question 30

Foveolar hyperplasia and dilated cystic glands are the pathologic feature of? Endoscopic findings? Mechanism?

Answer 30

Ménétrier’s Disease Irregular hypertrophic folds in the stomach Increased transforming growth factor alpha -> binds epidermal growth factor receptor -> mucosal gland hyperplasia

Question 31

Gastrointestinal stromal tumor‘s are usually do to enhanced signaling in this pathway?

Answer 31

C-kit and platelet-derived growth factor receptor

Question 32

Amylin - synthesized by? Function?

Answer 32

Pancreatic beta cells Suppresses glucagon secretion, delayed gastric emptying, induces satiety

Question 33

Difference in function between leptin and amylin?

Answer 33

Both induce satiety but amylin delays gastric emptying

Question 34

Ghrelin nickname? Function?

Answer 34

“Hunger hormone“ – increase his food intake

Question 35

Hormones that suppress food intake?

Answer 35

Leptin, peptide YY, Amylin Lin, GLP-1

Question 36

Hormones that delayed gastric emptying?

Answer 36

CCK, secretary, peptide YY

Question 37

Function of VIP?

Answer 37

Vasodilation, gastric acid inhibition, smooth muscle relaxation, and increased epithelial secretion,

Question 38

Function of Pancreatic polypeptide?

Answer 38

Inhibits pancreatic enzyme secretion

Question 39

Function of CCK?

Answer 39

Pancreatic enzyme secretion, gallbladder contraction, Sphincter of Oddi relaxation