NBME 18

Question 1

Most likely cause of findings is abnormal proliferation of what cell type?

• Child
• osteolytic and soft tissue mass in skull
• mild, smooth inward displacement of dura
• “sheet-like infiltrate of pale eosinophilic cells w/bean-shaped nuclei”
• Birbeck granules
• CD1a positive

Answer 1

Langerhans cells

Question 2

What disease process is similar to the below?

• animal experiment with defect in innate GI defense
• decreased gastric acid
• decreased mucous thickness and hyperplasia of enterchromaggin-like cells

Answer 2

Chronic gastritis

Question 3

What structure most likely being targeted by antibodies?

• 70 yo w/skin blistering
• tense bullae in joint folds of UE/LE
• supepidermal blister formations
• Abs against proteins at dermal-epidermal junction

Answer 3

Hemidesmosomes

Bullous pemphigoid

Question 4

Start a statin, what adaptive response at cellular level will be seen?

Answer 4

Increased transcription of HMG-CoA reductase

Question 5

In a dehydrated, hypovolemic man what tubular osmolality will he have compared to serum?

Answer 5

Isotonic at proximal tubule
hypotonic at macula densa
hypertonic at medullary collecting duct

Question 6

Diphenhydramine helps with motion sickness by blocking

Answer 6

M3 receptors

it is also a H1 blocker

Question 7

Porphyria cutanea tarda, what serves as precursor for uroporphyrin?

Answer 7

Succinyl-CoA

Question 8

Old lady with severe left sided HA

• lasts 30-60 seconds
• shoots from left ear down jawline
• pain precipitated by chewing/brushing teeth
• moderate dental caries

Answer 8

trigeminal neuralgia

Question 9

Man given infusion of 2g calcium chloride over 2 hrs, compared to pre-infusion, serum concentration of what is likely increased?
-Ca increased to 11.5 mg/dL

Answer 9

24,25-Dihydroxycholecalciferol

Question 10

Boy with nosebleeds and easy bruising, what platelet abnormality is most likely causing symptoms?

• URI 3 weeks ago
• ecchymoses over UE/LE
• blood work all normal except decreased Pet
• BM smear increased megakaryocytes

Answer 10

Antibodies directed against glycoprotein IIb/IIIa complex

ITP

Question 11

Klinefelter’s, where would error in chromosome segregation most likely occur during anaphase in the father?

Answer 11

Primary spermatocyte

Question 12

With ARDS, damage to what will most likely preclude restoration of normal tissue architecture and pulmonary function?

Answer 12

Basement membrane

Question 13

Slow recovery from succinyl-CoA due to genetic abnormality in

Answer 13

pseudocholinesterase

Question 14

Most active cell division area in small intestine epithelium

Answer 14

base of crypt

Question 15

2 month with vomiting, diarrhea, dehydration
what are the physical and chemical properties of pathogen?
-stool is negative
-viral particles with wheel like shape

Answer 15

dsRNA, segmented
naked
icosahedral
Rotavirus?

Question 16

Fever, flank pain, pain with urination, nausea
treated with cipro and returns with similar symptoms, why?
-taking alendronate, calcium carbonate, ezetimibe, HCTZ, simvastatin

Answer 16

Interaction between cipro (cyp inhibitor) and calcium carbonate causing more stones

Question 17

Baby in respiratory distress with herniation of abdominal contents, what caused this abnormality?

Answer 17

maldevelopment of left pleuroperitoneal membrane

Question 18

SOB w/exertion

abnormally brisk upstroke of carotid pulse w/downstroke to fall precipitously

Answer 18

aortic regurgitation

Question 19

In patient with lung cancer, cachexia, significant muscle wasting, what intracellular component is most likely increased in muscle cells?

Answer 19

autophagic vacuoles

Question 20

Post-splenectomy you see target cells, this is due to loss of function of what part of the spleen?

Answer 20

Red pulp

Question 21

Patient gets adrenal failure after Neisseria meningitides infection what is next step to determine cause

Answer 21

ACTH stimulation test

Question 22

Little girl with recurrent skin and oral mucosa infections since birth, most likely defective production of what?

• Labs show neutrophils but biopsy shows no neutrophils
• staph aureas

Answer 22

integrin
Leukocyte adhesion deficiency type 1 (AR)
defect in LFA-1 integrin (CD18) protein found on phagocytes
impaired migration and chemotaxis

Question 23

SOB w/exertion
Hx nosebleeds since adolescence
albuterol doesn't improve symptoms
red spots on tongue
nails

Answer 23

pulmonary AV shunting seen in osler weber rendu

• inherited disorder of blood vessels
• branching skin lesions (telangiectasis)
• recurrent epistaxis
• skin discolorations
• AVMs
• GI bleeding
• hematuria

Question 24

MCC of death in scleroderma/CREST

Answer 24

pulmonary HTN

Question 25

In celiac disease, there is a dysfunction of what cell

Answer 25

enterocyte

Question 26

Baby in womb found to have dilated collecting system and pelvis of left kidney with compressed renal cortex. Normal right kidney. Ureters are dilated. Amniotic fluid normal. What is the cause?

Answer 26

incomplete recanalization of proximal ureter

Question 27

randomly assigning women to one of two groups is for what purpose

Answer 27

get two groups with similar underlying characteristics

Question 28

cleaning with alcohol inactivates what kind of viruses

Answer 28

enveloped viruses

Question 29

strep progenies virulence factor that causes sandpaper like rash

Answer 29

erythrogenic toxin

Question 30

perforated diverticulitis in patient that dies 2 days later has rind on liver, what is it made of?

Answer 30

Fibrin

Question 31

Initial drop in coronary blood flow with adenosine is due to

Answer 31

coronary dilation by A2

Question 32

Boy with intermittent vomiting, progressive clumsiness

• impaired upward gaze and pupil response unilateral
• shuffling gait
• enlarged lateral and third ventricles
• 2 cm mass

Answer 32

Pinealoma
Parinaud syndrome
precocious puberty in boys (beta hCG)
histologically similar to germ cell tumor (testicular seminoma)

Question 33

which anti fungal will decrease gluten expression on fungal cell surface

Answer 33

capsofungin

Question 34

Child with severe chronic diarrhea d/t Giardia
-expresses CD3 and CD4 but not CD40 ligand
what immunoglobulin isotope predominates and what are its biologic properties?

Answer 34

Hyper IgM syndrome

activates complement

Question 35

visible pulsation above manubrium of sternum and displacement of trachea to the right
man with increasingly severe deep chest pain

Answer 35

aortic aneurysm

Question 36

After heart transplant, you get HTN, kidney failure all due to what drug?

Answer 36

cyclosporine