HELP! NBME Form 3 Q and A

[02115]

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I thought NBME form 3 was pretty difficult. I had the following questions and was wondering what people thought

Section 1:
For the woman with renal failure and the palpable mass extending upward from the pubic symphysis it asked was that pre-renal or post-renal failure? I was thinking it must be post-renal because the mass was her bladder?? There was also a similar question in section 4.

For the 6 month old male who was sluggish and edematous with coarse facial features and poor muscle tone, what was the diagnosis? I thought cretinism but that didn't quite "fit."

Section 2:
For the cross section of the brain where the 80% loss of neurons occur, what was that? I thought it might be the substantia nigra or subthalamic nuclei. So then the answer would've been the striatum???

For the question about viremia, I guessed primary varicella infection since that would be system, right??

What on earth was the pathogen that gave the Peace Corps volunteer the dysuria, RBC in urine, hydronephrosis and nodules in bladder? I had absolutely no clue and guessed mycobacteria.

For the old man who was urinating 8-10 times per day and had a whopping serum Na, was that an aldosterone secreting neoplasm???

Section 3:
For the man who came in with abdominal pain and spoke no english but his daughter spoke spanish, would it be appropriate to ask her to translate since this sounded like a medical emergency?

Do you want to decrease NaCl intake in patients with hepatic disease and edema because secondary aldosteronism is present?

For the graph with the two antibiotics and apparent synergy does anyone know what that was?

For the daycare kindergarten teacher with bloody diarrhea, I was surprised that Yersinia wasn't a choice and couldn't decide between Salmonella Typhi (unlikely) or Shigella flexneri

For the alcoholic who fell and banged his head, what blood vessel was damaged?

Was psychosis the result of the dopamine overdose?

For the man with osteoblastic vertebrae discovered after he hurt his back painting the garage, how did you tell between multiple myeloma and metastatic prostate CA? I assumed since he had regular check ups he would've been screened for prostate CA.

Lactase deficiency is most manifest in the colon, right????

What is the difference between biliary colic and acute cholecystitis? Is it that biliary colic is more chronic??

Why is diabetes more difficult to control after a weight gain?

Does hepatic oxidation decrease the most with aging?

What was up with the woman who couldn't menstruate. Was that premature ovarian failure or polycystic kidney?

 

[dara678]

for the question with the spanish speaking patient, i said to ask a professional translator to come in -- we learned in our "doctoring" class that is actually inappropriate to ask a relative to translate because things might get lost along the way (i.e. the daughter might not include information to protect her dad, for example).

 

[nrosigh]

For the woman with renal failure and the palpable mass extending upward from the pubic symphysis it asked was that pre-renal or post-renal failure? I was thinking it must be post-renal because the mass was her bladder?? There was also a similar question in section 4.

Yes, postrenal.

For the 6 month old male who was sluggish and edematous with coarse facial features and poor muscle tone, what was the diagnosis? I thought cretinism but that didn't quite "fit."

Yes.

Section 2:
For the cross section of the brain where the 80% loss of neurons occur, what was that? I thought it might be the substantia nigra or subthalamic nuclei. So then the answer would've been the striatum???

Substantia nigra.

For the question about viremia, I guessed primary varicella infection since that would be system, right??

Yes.

What on earth was the pathogen that gave the Peace Corps volunteer the dysuria, RBC in urine, hydronephrosis and nodules in bladder? I had absolutely no clue and guessed mycobacteria.

Shistosoma hematobium.

For the old man who was urinating 8-10 times per day and had a whopping serum Na, was that an aldosterone secreting neoplasm???

Don't remember this one.

Section 3:
For the man who came in with abdominal pain and spoke no english but his daughter spoke spanish, would it be appropriate to ask her to translate since this sounded like a medical emergency?

Always get a professional translator.

Do you want to decrease NaCl intake in patients with hepatic disease and edema because secondary aldosteronism is present?

Yes

For the graph with the two antibiotics and apparent synergy does anyone know what that was?

Aminoglycosides are synergistic with beta-lactams.

For the daycare kindergarten teacher with bloody diarrhea, I was surprised that Yersinia wasn't a choice and couldn't decide between Salmonella Typhi (unlikely) or Shigella flexneri

Shigella is a common day-care pathogen.

For the alcoholic who fell and banged his head, what blood vessel was damaged?

I don't remember this one. If it's acute = middle meningeal. If it's more chronic (2-3 days before symptoms) thin it's tearing of the bridging veins.

Was psychosis the result of the dopamine overdose?

I thought so....

For the man with osteoblastic vertebrae discovered after he hurt his back painting the garage, how did you tell between multiple myeloma and metastatic prostate CA? I assumed since he had regular check ups he would've been screened for prostate CA.

I think this is classic for Prostate CA.
Multiple myeloma will probably present with infection and anemia first.

Lactase deficiency is most manifest in the colon, right????

Brush border of small intestine.

What is the difference between biliary colic and acute cholecystitis? Is it that biliary colic is more chronic??

Biliary Colic is not an infection - intermittent colicky pain. With acute cholecystitis you should see systemic signs like fever.

Why is diabetes more difficult to control after a weight gain?

Increasing adipose downregulates insulin receptors.

Does hepatic oxidation decrease the most with aging?

Yes, you lose phase 1 oxidative reactions first. If they had said "GFR" that would probably have been the best answer.

What was up with the woman who couldn't menstruate. Was that premature ovarian failure or polycystic kidney?

If I remember correctly I think it was ovarian failure but I don't remember the question. In PCOS (which is what I assume you meant) you will have HIGH FSH but normal LH, and HIGH testosterone and estrogens.

 

[02115]

Thank You So Much!!!!!

 

[02115]

I have another question from form 3:

Which of the following abnormalities is likely in a woman with small cell lung cancer:

a) Hypocalcemia
b) Hypoglycemia
c) Hyponatremia
d) Polycythemia

According to FA squamous cell CA produces PTH and that would increase calcium, so I don't think it's A. Small cell carcinoma produces ADH or ACTH. ADH would cause dilutional hyponatremia, so that would suggest C. But wouldn't ACTH upregulate aldosterone which would lead to sodium retention???

Thanks so much for answering all these questions-- I really appreciate it!

 

[xjacob]

I have another question from form 3:

Which of the following abnormalities is likely in a woman with small cell lung cancer:

a) Hypocalcemia
b) Hypoglycemia
c) Hyponatremia
d) Polycythemia

According to FA squamous cell CA produces PTH and that would increase calcium, so I don't think it's A. Small cell carcinoma produces ADH or ACTH. ADH would cause dilutional hyponatremia, so that would suggest C. But wouldn't ACTH upregulate aldosterone which would lead to sodium retention???

Thanks so much for answering all these questions-- I really appreciate it!

I think you are right about sq. cell ca. producing PTH (or PTHrp), but remember that small cell ca. can produce more than just ADH or ACTH (somewhere deep in my notes I have like 10 diff. hormones written...not like I'm gonna memorize them). Anyway, the point is that even tho it can produce almost anything, it is prob. not gonna produce more than one hormone at a time. So an ADH secreting tumor will cause hyponatremia, and we can go with option C.
One more thing. I am almost 100% sure that ACTH does NOT stimulate aldosterone secretion (cf. cushing's dz, where aldo is more or less normal). It stimulates cortisol. However, cortisol does have some degree of mineralocorticoid activity, altho incomparably less than aldo (unless you eat lycorice).

 

[02115]

I think you are, right, xjacob!. According to Wikipedia:

ACTH acts through the stimulation of cell surface ACTH receptors, which are primarily located on the adrenocortical cells. ACTH stimulates the cortex of the adrenal gland and boosts the synthesis of corticosteroids, mainly glucocorticoids but also mineralcorticoids and sex steroids (androgens).

However, FA says aldosterone secretion is primarily controlled by the renin-angiotensin system so the "most likely" answer would by hyponatremia due to ADH secretion.

 

[nrosigh]

It's easy to remember:

Small cells makes the two A's: ACTH and ADH
Squamous makes PTH

Done.

I think you are, right, xjacob!. According to Wikipedia:

ACTH acts through the stimulation of cell surface ACTH receptors, which are primarily located on the adrenocortical cells. ACTH stimulates the cortex of the adrenal gland and boosts the synthesis of corticosteroids, mainly glucocorticoids but also mineralcorticoids and sex steroids (androgens).

However, FA says aldosterone secretion is primarily controlled by the renin-angiotensin system so the "most likely" answer would by hyponatremia due to ADH secretion.

 

[02115]

Ok, here is another question: If you get a p value of 0.2 then that means there is a 20% chance that your observation is due to chance, right??

Can I say thank you to nrosigh? I understand you already took Step I but are still helping others. Truly, you embody the best principles of the medical profession!

 

[lealf-ye]

Ok, here is another question: If you get a p value of 0.2 then that means there is a 20% chance that your observation is due to chance, right??


Yes, I think so.

 

[exmike]

I have another question from form 3:

Which of the following abnormalities is likely in a woman with small cell lung cancer:

a) Hypocalcemia
b) Hypoglycemia
c) Hyponatremia
d) Polycythemia

According to FA squamous cell CA produces PTH and that would increase calcium, so I don't think it's A. Small cell carcinoma produces ADH or ACTH. ADH would cause dilutional hyponatremia, so that would suggest C. But wouldn't ACTH upregulate aldosterone which would lead to sodium retention???
Thanks so much for answering all these questions-- I really appreciate it!

Small cell is known to produce ADH so what you would expect is SIADH.
SIADH always causes hyponatremia. In fact a Sodium less than 120 is almost always SIADH.

Also, increased ACTH tends to increase cortisol and sex hormones while leaving aldosterone unchanged so even if it was ACTH secreting, you wouldnt have sodium retention.

 

[lealf-ye]

Originally Posted by 02115
Section 3:
For the man who came in with abdominal pain and spoke no english but his daughter spoke spanish, would it be appropriate to ask her to translate since this sounded like a medical emergency?



Always get a professional translator.


why do we always need translator? I thought we only use it when not family member understand English....

 

[lealf-ye]

how cimetidine will affect warfarin? inhibit p-450 and increase warfarin level? I am not sure if warfarin is metabolized by p-450....

3 y.o in day care center, get intense bilateral conjunctival erythema and mild serous exudate -- caused by Adenovirus?

 

[02115]

I think cimetidine does interfere with warfarin metabolism. According to Wikipedia, warfarin is metabolized by multiple CYPs and cimetidine is a known CYP450 inhibitor. I think I remember this question from QBank.

For the 3 y/o I put adenovirus as well.

 

[lisa13579]

Cimetidine is def. one of the p450 inhibitors, therefore will increase warfarin concentration.

Ditto on chosing adenovirus. The mild serous exudate makes me think viral rather than bacterial and adeno commonly causes conjunctivitis. (don't remember what the other choices were in that questions)

 

[zeloc]

The question about the erthrocyte swelling after adding NaCl, how can the conc. of NaCl be determined? The RBC increased by 50%.