3/19 UWORLD test #52

Question 1

Q 2. What is the most common outcome of HepB infection?

Answer 1

acute hepatitis with complete resolution

> 95%

Question 2

Q 3. impaired adduction of eye to contralateral gaze. where is lesion? what disease?

Answer 2

MLF

multiple sclerosis

Question 3

Q 3. Young adult experiencing episodic CNS dysfunction that partially or fully resolves. what should I suspect?

Answer 3

multiple sclerosis

repeating recovery & relapsing

Question 4

Q 3. What is saltatory conduction? What disease manifests decreased saltatory conduction

Answer 4

electrical signal transduction along axon by jumping.

multiple sclerosis

Question 5

Q 4. Very severe burst of coughing. sometimes so severe, causing vomiting afterward coughing. What bug should I think?

Answer 5

whoping cough

Bordetella pertussis

Question 6

Q 4. Bordetella pertussis: Gram stain? shape?

Answer 6

gram negative cocobacilli

Question 7

Q 4. X-ray finding of Bordetella pertussis?

Answer 7

normal chest X-ray

Question 8

Q 4. What patient history is clue for Bordetella pertussis

Answer 8

• long cough duration (over 100 days)

- took a vaccine when young, but didn’t get any vaccination since then: absence of booster Tdap vaccine

Question 9

Q 5. compare motor symptoms: serotonin syndrome vs. neuroleptic malignant syndrome

Answer 9

• serotonin syndrome
  : more like clonus, hyperreflexia
• neuroleptic malignant syndrome
  : rigidity, bradyreflexia

Question 10

Q 6. How CO poisoning affects methamoglobin level? what about PaO2?

Answer 10

NO affect on both methemoglobin & PaO2

methemoglobin
PaO2: oxygen dissolve in blood

oxygen CONTENT (oxygen bound to Hb+ oxygen dissolved in blood) is lowered in CO poisoning

Question 11

Q 8. How does kidney responds to acidic urine?

Answer 11

renal ammoniagenesis

generate ammonia and send it to buffer acid

Question 12

Q 9. Renal ammoniagenesis uses what amino acid as a precursor of ammonia?

Answer 12

glutamine

Question 13

Q 10. How does protein M works as virulence factor in group A strep?

Answer 13

inhibits phagocytosis and complement activation

Question 14

Q 11. What is the most common cause gram positive bug of sepsis in sickle cell disease patients?

Answer 14

strep.pneumoniae

sickel cell: asplenic -> increased susceptibility to encapsulated bacteria

Question 15

Q 13. What is reticulocyte? describe how its level changes with vitamin B12 injection therapy for vitamin B12 deficiency anemia

Answer 15

reticulocyte is immature RBC

with vitamin B12 injection, reticulocytes are synthesized and released in blood stream. After about 1 week, reticulocyte level drops, as it becomes mature RBC

It takes about 8 weeks to fix anemia with vitamin B12 injection for erythropoiesis induction

Question 16

Q 15. Wild, large-amplitutde, flinging jerk characterizes what kind of tremor? which nucleus is impaired?

Answer 16

hemiballismus

subthalmic nucleus

• one side leg & arm jerk may not be explicitily mentioned in question. In question, it may say like wild jerk movements so that patient throw beer can involuntarility, things like that.

Question 17

Q 16. increased RBC, leukocytes, platelet: what should I think?

Answer 17

myeloproliferative disorders
depending on which one is more siginificantly increased than others, it can be
PV or ET

Question 18

Q 16. What gene mutation is associated with myeloproliferative disorders? what is function of this gene?

Answer 18

JAK2 mutation

JAK2: cytoplasmic tyrosine kinase for JAK-STAT pathway

EPO binds to EPO receptor, intracellular JAK2 binds to EPO receptor and activates JAK-STAT signaling pathway
Mutated JAK2 leads to abnormal growth signling

Question 19

Q 18. Systemic mastocytosis

• associated with what gene
• excess secretion of what compound
• complication

Answer 19

• KIT gene mutation
• excess mast cells –> excess histamine
• histamine -> may also stimulate parietal cell –> excess gastric acid secretion

Question 20

Q 18. Cimetidine

• MOA
• indication
• side effects

Answer 20

• H2 blocker -> less gastric acid secretion from parietal cells
• gastriitis, GERD
• side effects
  1. potent CYP-450 inhibitor
  2. anti-androgen effects (gynecomastia, impotence, decreased libido)

Question 21

Q 20. Why serum ferritin is high in hereditary hemochromatosis?

Answer 21

HFE gene -> increased intestinal iron absorption

Question 22

Q 23. What is first line for acute gout?

Answer 22

NSAID

Question 23

Q 25. heart manifestation of Turner?

Answer 23

coarctation

Question 24

Q 25. heart manifestation of tuberous sclerosis?

Answer 24

valvular obstruction by rhabdomyoma

Question 25

Q 26. Brown adipose tissue - where is it located - gross appearance - function

Answer 25

- around kidneys and adrenal glands - brown pigmented tan-fat containing tissue ( increased mitochondria within adipose tissue gives tan color) - heat generation

Question 26

Q 27. Why anti-depressants should be avoid in bipolar disorder?

Answer 26

anti-depressatns may induce mania

Question 27

Q 28. What is the location of pancoast tumor?

Answer 27

superior sulcus: apex of lung, grove formed by subclavian vessels * in fact, pancoast tumor is also called as superior sulcus tumor

Question 28

Q 29. How mitral regurgitation changes below? explain - preload - afterload - ejection fraction

Answer 28

- preload: increased As blood regurging back to LA, more diastolic LV pressure - afterload: decreased more LV filled, less resistance for LV ejecting blood - ejection fraction: increased more LV filled, more forceful ejection

Question 29

Q 30. What does grapefruit juice do on CYP-450?

Answer 29

CYP450 inhibitor

Question 30

Q 30. Is CYP-450 exist in the gut wall?

Answer 30

yes. major location of CYP450 is hepatocyte for sure. but gut wall also contains CYP450. This is why drinking grapefruit juice can inhibit CYP450

Question 31

Q 31. MRI finding: similarities and differences between pilocytic astrocytoma vs. medulloblastoma

Answer 31

Similarity: pilocytic astrocytoma an medulloblastoma BOTH commonly arise from cerebellum Difference: - pilocytic astrocytoma: combination of cyst + solid - medulloblastoma: solid

Question 32

Q 33. dietary restriction for fructose intolerance?

Answer 32

fructose and sucrose | sucrose -> metabolized to fructose

Question 33

Q 34. Is APC activated or inactivated in FAP?

Answer 33

inactivated

Question 34

Q 34. Is BRCA1 tumor suppressor gene? or oncogene? How mutation alters BRCA1 in breast cancer? What is its normal function?

Answer 34

BRCA1- neither tumor suppressor or oncogene it mediates DNA repair In breast cancer, loss of function mutation of BRCA1 leads to cancer development. BRCA1 mutation is example is incomplete penetrance, not all individuals with BRCA1 mutation will develop breast cancer

Question 35

Q 37. breast cancer with dimpling. What is dimpling? Existence dimpling suggest cancer cells invade through what structure?

Answer 35

dimpling is skin retraction. | That is, skin gets shallow underneath the mass, meaning cancer cells invade through suspensory ligament

Question 36

Q 38. Apart from SSRI and SNRI, what other drug may be useful for treating panic disorder?

Answer 36

BDZ

Question 37

Q 39. What is the primary mechanism of development of stress incontinence during pregnany?

Answer 37

increased intra-abdominal pressure

Question 38

Q 40. What are three most common underlying conditions that predisposes to subacute infective endocarditis?

Answer 38

MVP, prosthetic valve, valvular sclerosis pre-damaged valve -> more likely damaged by infection *historically rheumatic heart disease was also considered as common cause for bacterial endocarditis, but nowadays in developed countries, the association drops due to increased recognition to group A strep