Exam 4- Clinical Correlations

Question 1

Indigestion, loss of appetite, abd pain, “oily” diarrhea, and ulcers on endoscopy eval might be concerning for what?

Answer 1

Zollinger-Ellison syndrome

Question 2

What might lab values for Zollinger-Ellison syndrome show?

Answer 2

Elevated serum gastrin level, elevated gastric H+ secretion

Question 3

If pt with Zollinger-Ellison synrome has a mass on the pancreas identified as a gastrinoma, what is the management? (2)

Answer 3

Omeprazole (proton pump inhibitor) prior to surgery, then laparoscopic surgery

Question 4

What is the cause of the high levels of gastrin in Zollinger-Ellison syndrome?

Answer 4

Gastrinoma NOT controlled by feedback mechanisms

Question 5

What is the result of high levels of gastrin in Zollinger-Ellison syndrome? (3)

Answer 5

Hypersecretion of gastric acid, hypertrophy of gastric mucosa, ulcers

Question 6

What test is used involves infusion of a gastrin analogue while the stomach contents are sampled using a nasogastric tube?

Answer 6

Pentagastrin stimulation test

Question 7

In healthy individuals, pentagastrin stimulates H+ by parietal cells to what levels?

Answer 7

3x higher than basal secretion

Question 8

Why would a pentagastrin stimulation test likely have no effect on a pt with Zollinger-Ellison syndrome?

Answer 8

H+ secretion already maximal

Question 9

For unknown reasons, secretin directly stimulates gastrin release by gastrinoma cells, but not what type of cells?

Answer 9

Antral G cells

Question 10

What is the result of a secretion stimulation test in a pt with Zollinger-Ellison syndrome?

Answer 10

Serum gastrin increases (N response = decreased or unchanged)

Question 11

What is the cause for “oily” stools (steatorrhea) in a pt with Zollinger-Ellison syndrome?

Answer 11

Inactivation of pancreatic lipase by low duodenal pH

Question 12

Loss of more than 100cm of terminal ileum will disrupt what process?

Answer 12

Enterohepatic circulation of bile salts

Question 13

What might be the cause of a pt losing bile salts faster than the liver can replace them and what will this result in?

Answer 13

Ileal resection, lipid digestion greatly impaired

Question 14

Why would a pt with an ileal resection present with oily, pale, and foul smelling stool?

Answer 14

Result of bile salt depletion is steatorrhea (undigested fat in stool)

Question 15

Bile salts stimulate Cl- and water secretion in the colon, casuing what clinical presentation? (ileal resection)

Answer 15

Chronic diarrhea

Question 16

What is a cationic resin that binds bile salts and results in their excretion?

Answer 16

Cholestyramine

Question 17

Cholestyramine was originally used to treat what condition?

Answer 17

Hypercholesterolemia (loss of bile salts stimulates hepatic synthesis of new bile salts from cholesterol)

Question 18

How does cholestyramine reduce diarrhea?

Answer 18

Binds bile salts so they do not stimulate Cl- and fluid secretion by the colon

Question 19

What is the largest and most structurally complicated vitamin and is aka cobalamin?

Answer 19

Vit B12

Question 20

Why must a pt with an ileal resection have Vit B12 injections?

Answer 20

Intrinsic factor B12 complex is normally absorbed by the ileum

Question 21

Pt presenting with “acid indigestion” described as burning and dull ache in her stomach, what might you be concerned for?

Answer 21

H.pylori infection/ peptic ulcer disease

Question 22

The results of a serological test and a C-urea breath test consistent with H.pylori might be concerning for what disease?

Answer 22

Peptic ulcer disease

Question 23

What is used to treat a pt with peptic ulcer disease from H. pylori? (2)

Answer 23

Antibiotic and proton pump inhibitor (Omeprazole)

Question 24

What is defined as an ulcerative lesion of the gastric or duodenal mucosa caused by erosive and digestive actions of H+ and pepsin on the mucosa (which is ordinarily protected by mucous and HCO3-)?

Answer 24

Peptic ulcer disease

Question 25

What pathogen is a G- bacterium that colonizes the gastric mucosa and can lead to gastric and duodenal ulcers, usually in the antrum?

Answer 25

H. pylori

Question 26

What is requied for peptic ulcer formation? (3)

Answer 26

1. loss of protective mucous barrier, 2. excessive H+ and pepsin secretion, 3. combo of the two

Question 27

What factors outside of H+ and pepsin can lead to peptic ulcer disease? (5)

Answer 27

H. pylori infection, NSAIDs, stress, smoking, alcohol

Question 28

What virulence factors of H. pylori allows for their destruction and survival in the stomach? (2)

Answer 28

Cytotoxins break down protective mucous. Releases urease which converts urea to NH3. NH3 to protonated to NH4 leading to an alkalinization of their local enviroment allowing bacteria to survive

Question 29

How does H. pylori cause a duodenal ulcer?

Answer 29

Infection and inflammation leads to decreased HCO3- secretion

Question 30

How can H. pylori infections of peptic ulcer disease be diagnosed? (3)

Answer 30

Serologic tests for antibodies, C-urea breath test (measurement of CO2 produced by H.pylori), endoscopic bx

Question 31

What is the treatment for an H.pylori infection? (2)

Answer 31

Abx + proton pump inhibitor (Omeprazole)