Clinical Cases

Question 1

What’s the name of the condition where you have a gastrinoma?

Answer 1

Zollinger-Ellison Syndrome

Question 2

What will happen to gastric H+ secretion if you have Zollinger-Ellison Syndrome?

Answer 2

VERY high

Question 3

If you have Zollinger-Ellison syndrome and you do a pentagastrin stimulation test, what will happen to H+ secretion?

Answer 3

It won’t be increased since H+ secretion is already maxed out

Question 4

What will happen to someone with zollinger Ellison syndrome if you do a secretin stimulation test?

Answer 4

Gastrin will increase

Question 5

Gastrin secretion by gastrinomas (is/is not) controlled by feedback mechanisms

Answer 5

Is not

Question 6

What’s the big deal if you have hypersecretion of gastrin anyways?

Answer 6

Can cause ulcers and hypertrophy of the gastric mucosa

Question 7

How do you treat acid hypersecretion’?

Answer 7

Proton pump inhibitors (omeprazole)

Question 8

What happens to normal people if you do a pentagastrin stimulation test?

Answer 8

Pentagastrin would stimulate H+ secretion to levels 3x higher than normal

Question 9

In zollinger Ellison syndrome, giving secretin causes the release of ________

Answer 9

Gastrin

Question 10

In normal people, giving secretin would have what effect on gastrin release?

Answer 10

Gastrin would stay the same or decrease

Question 11

Why does someone with zollinger Ellison syndrome have steatorrhea (oily stool)

Answer 11

Pancreatic lipase will be denatured by the extremely high pH in the small intestine

Question 12

Why would someone who’s missing 80% of their ileum have diarrhea and oily stools?

Answer 12

No bile salt reabsorption= losing bile salts faster than liver can replace them.

Deficient bile= impaired lipid digestion= oily stool

Bile salts entering large intestine= stimulation of water secretion and intestinal motility= diarrhea
******

Question 13

How could you treat the diarrhea suffered by someone with 80% of their ileum removed?

Answer 13

Cholestyramine/bile acid binding resin will bind to the bile salts and “hide” them from the large intestine so it won’t freak out and cause a bunch of water secretion and diarrhea when bile salts enter the colon.

Question 14

How much bile salt usually makes it into the colon?

Answer 14

Almost none!

Question 15

What vitamin will our patient who is missing 80% of his ileum be deficient in?

Answer 15

B12

It is absorbed in the ILEUM bound to intrinsic factor***

Question 16

How do we treat B12 deficiency if patient is missing 80% of their ileum?

Answer 16

B12 injections (oral b12 will do nothing)

Question 17

What two tests can be done to diagnose H Pylori?

Answer 17

Serological test- looking for antibodies against H Pylori

13C-Urea breath test

Question 18

How does the 13C-Urea Breath test look for H pylori?

Answer 18

Patient is given urea labeled with 13C. H Pylori urease will metabolize it to 13CO2 and NH3.
13CO2 is breathed out and measured.

Question 19

How does H Pylori cause gastric ulcers?

Answer 19

It releases cytotoxins that break down the protective mucus

Question 20

How can h pylori survive in the low pH of the stomach?

Answer 20

It has urease which converts urea to NH4+, which alkalinizes the environment

Question 21

How does H Pylori cause ~duodenal~ ulcers?

Answer 21

Two ways:

Inhibits D cells= no somatostatin= G cells go crazy making gastrin= tons of H+ secretion

Inhibits HCO3- secretion in pancreatic ductal cells

Question 22

How do you treat H Pylori infection?

Answer 22

Antibiotic

Antacid