USMLE Rx: Week of 12/18/16

Question 1

Where do Zollinger-Ellison tumors usually present?

Answer 1

In the pancreas (occasionally in those with MEN 1). This is noteworthy because gastrin-secreting G cells are normally in the stomach.

Question 2

What should you be thinking if a patient being treated for TB presents with fever and swollen joints?

Answer 2

Drug-induced lupus from isoniazid!

Question 3

How does isoniazid work?

Answer 3

It inhibits the synthesis of mycolic acids.

Question 4

From outside to inside, what are the layers of the epidermis?

Answer 4

Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basalis

(“Californians Like Girls in String Bikinis.”)

Question 5

Which layer of the epidermis contains melanocytes?

Answer 5

The stratum basalis

Question 6

Why does hypoglycemia result in those lacking aldolase B?

Answer 6

Aldolase B deficiency is also called fructose intolerance, and it leads to hypoglycemia because fructose-1 phosphate accumulates in the liver and absorbs phosphate stores. Thus, there is not sufficient phosphate for glycogenolysis or gluconeogenesis.

Question 7

What inborn error of metabolism presents with infantile cataracts?

Answer 7

Galactosemia (both kinds).

Think of the milky way galaxies in babies eyes.

Question 8

I-cell disease presents with elevated serum ______________.

Answer 8

lysosomal enzymes; these enzymes are supposed to get sent to organelles, but they don’t –because of absent mannose-6 phosphate –and then leak out

Question 9

Which H2-antagonist causes gynecomastia?

Answer 9

Cimetidine

Question 10

What acid-base patterns does aspirin overdose cause?

Answer 10

Respiratory alkalosis (via direct stimulation of respiratory drive) and metabolic acidosis

Question 11

What could you give to someone who has overdosed on an acidic drug (such as aspirin)?

Answer 11

Bicarbonate, because it alkalinizes the urine

Question 12

What is a common sequela of acute pancreatitis?

Answer 12

Pseudocysts

Question 13

____________ disease is a tuberculous infection of the bone.

Answer 13

Pott

Question 14

Gingival hypertrophy and coarse facial features are suggestive of _____________.

Answer 14

I-cell disease

Question 15

Describe where the IVC, aorta, and esophagus pass through the diaphragm.

Answer 15

IVC: through a hole in the central tendon
Aorta: “under” (posterior to) the median arcuate ligament
Esophagus: esophageal hiatus

Question 16

What does a negative skew look like?

Answer 16

The bell curve shifts to the right with a long tail to the left; mean is less than median is less than mode

Question 17

In a positively skewed bell curve, the mean is _________ than the median.

Answer 17

greater than

Question 18

The main treatment for those with genetic disorders that cause low ceruloplasmin is a ____________ antagonist.

Answer 18

chemical (because penicillamine is a chelating agent)

Question 19

In a randomized controlled trial, the most useful analytic parameter is ______________.

Answer 19

number needed to treat

Question 20

What mnemonic can help you remember Whipple disease?

Answer 20

"PASs me the WHIPPed cream"
Painful joints
Anorexia (aka weight loss) 
Steatorrhea 
Whipple

Also, the organism Tropheryma stains with PAS!

Question 21

What effect do fibrates like gemfibrozil have on blood lipids?

Answer 21

Moderate decrease in VLDL
Small increase in HDL
Large decrease in triglycerides

This happens because fibrates stimulate PPAR which induces lipoprotein lipase. LPL then hydrolyzes triglycerides.

(Remember the gemfibrozil jellyfish taking down the airship, scattering the trident men, and raising the submarine.)

Question 22

What patients take prostaglandins?

Answer 22

PUD patients!

Question 23

Again, which amino acids are essential?

Answer 23

Ketogenic: leucine, lysine
Both: phenylalanine, isoleucine, tryptophan, tyrosine
Glucogenic: methionine, histidine, valine

Question 24

Antibodies to ___________ stain for neoplasms of epithelial origin.

Answer 24

cytokeratin

Question 25

If a pathology report said the tissue stained for tubulin, what type of tumor would that suggest?

Answer 25

Neuroma (Think Neural Tube = Neuroma –Tubulin)

Question 26

What two volumes make up functional residual capacity?

Answer 26

RV and ERV

Question 27

In someone with emphysema, which volumes and capacities are pathologically increased?

Answer 27

RV is increased because those with emphysema can’t get air out of their lungs. This increases the two capacities that contain RV: FRC and TLC.

Question 28

What lab test can help diagnose Chediak-Higashi?

Answer 28

Blood smear with abnormally large granules, because CH results in defective phagocyte emptying

Question 29

Those with _______________ syndrome have high levels of IgE and IgA, but because they have low IgM they are susceptible to encapsulated bacteria.

Answer 29

Wiskott-Aldrich

Question 30

________________ is inherited in an X-linked recessive manner and presents with thrombocytopenic purpura, eczema, and recurrent pyogenic infections.

Answer 30

Wiskott-Aldrich

Question 31

_______________ can be acquired in the third decade of life and presents with failure of response to vaccination.

Answer 31

Common-variable immune deficiency (a defect in B-cell maturation)

Question 32

Calcitonin and TSH bind to which class of receptor?

Answer 32

GPCR

Question 33

True or false: use of acetazolamide can cause metabolic alkalosis.

Answer 33

False. Acetazolamide causes metabolic acidosis due to decreased bicarbonate resorption.

Question 34

CD28 binds to a receptor on which kind of cells?

Answer 34

Antigen-presenting cells (specifically, the B7 receptor)

Question 35

Which receptor binds to the Fc receptor (to opsonize cells/material)?

Answer 35

CD16 (opson1z6)

Question 36

What vitamin deficiency can present with alopecia?

Answer 36

B5 (“Without B5, you get a FIVEhead.”)

Question 37

What is different between ASDs in the general population and in those with Down syndrome?

Answer 37

ASDs in the general population result from defects in the septum secundum, but in those with Down syndrome it results from defects in the septum primum.

(Think of how septum primum kind of looks like the number 71 in Latin, and 71 looks like 21, as in trisomy 21.)

Question 38

Transposition of the great vessels results from failure _______________.

Answer 38

of the aorticopulmonary shunt to spiral

Question 39

How do organisms develop resistance to macrolides?

Answer 39

By methylation of a ribosomal binding site.

Think of the train in Breaking Bad –because macrolides prevent translocation and methylation sounds like meth.

Question 40

The serratus anterior muscle helps keep the scapula flat against the back and is innervated by the _____________ nerve.

Answer 40

long thoracic (think of Thor’s scapula protruding out and Hulk pounding it back in with Thor’s LONG hammer)

Question 41

Bilious vomiting and air in the biliary tree suggest ________________.

Answer 41

gallstone ileus

Question 42

What organs come from the endoderm and mesoderm?

Answer 42

Endoderm: GI tract, urinary tract, liver, pancreas, galbladder, and lungs
Mesoderm: blood, lymph, muscle, connective tissue, spleen, kidneys, adrenal cortex, heart, and reproductive organs

Question 43

What cells secrete a substance that promotes the release of bicarbonate from the duodenum?

Answer 43

S cells (which release secretin)

Question 44

What should you do in a case of suspected child abuse?

Answer 44

Treat the wounds in need of immediate care and alert the authorities.

Question 45

What is late-look bias?

Answer 45

A form of bias in which investigators only sample people who’ve had a certain disease for a long (late) time; this results in a sample that is skewed to people who have a milder form of the disease

Question 46

What kinds of cancer does benzene cause?

Answer 46

Leukemia (and aplastic anemia)

Question 47

What esophageal pathology does scleroderma cause?

Answer 47

Smooth muscle atrophy in the lower two-thirds of the esophagus

Question 48

How do somatostatinomas present?

Answer 48

Think of all that somatostatin does:

• hypochlorhydria (from decreased gastrin)
• diabetes (from decreased insulin)
• cholelithiasis (from decreased gallbladder contraction)
• diarrhea (not sure why)

Question 49

What is the classic presentation of VIPoma?

Answer 49

Dehydration (from watery diarrhea), hypokalemia (from excess diarrhea), and achlorhydria

Question 50

What stimulates the release of somatostatin?

Answer 50

Acid

Question 51

When are NK cells stimulated to kill?

Answer 51

When cells don’t possess MHC I

Question 52

Why does infarction to the PICA lead to ptosis?

Answer 52

PICA infarction (lateral medullary syndrome) affects the sympathetic fibers that pass up to the eye. Thus, lateral medullary syndrome presents with ipsilateral ptosis and miosis.