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 +0  (nbme20#42)

Patient has acutely decompensated heart failure, most likely due to an MI 5 days ago. Orthopnea-dyspnea-edema would mean he likely also has jugular venous distention and hepatic congestion.


 +0  (nbme20#33)

Got this one wrong because of those 2 unaffected children. Here's the explanation from FA pg 59:

Mitochondrial inheritance - Transmitted only through the mother. All offspring of affected females may show signs of disease.

Variable expression in a population or even within a family due to heteroplasmy.

Heteroplasmy basically means that multiple mitochondria are transmitted to each offspring. Their ratio may change at each generation, and cause more severe or less severe disease, even within the same family.

Those unaffected dudes lucked out.

dickass  That'll teach me not to skim FA, you really gotta look up the words you don't know.
chandlerbas  heteroplasmy is a fancy way of saying variable expressivity just specific to mitochondrial diseases i do declare

 +0  (nbme20#19)

SIADH: + Excessive free water retention + Euvolemic hyponatremia with continued urinary Na excretion + Urine osmolality > serum osmolality

Body responds to water retention with DECREASED aldosterone and INCREASED ANP and BNP

Water retention => Less aldosterone => Less ENAC channels => Less sodium reuptake => Loss of sodium in urine


 +1  (nbme20#24)

...migrant workers ...has not received routine medical care ==> she was not screened for hypothyroidism


 +0  (nbme20#38)

Yeah, so, turns out this is not Nephrogenic DI due to lithium use, you don't give lithium to treat schizophrenia.


 +1  (nbme20#32)

Nonmaleficence: “Do no harm.”

Even if the patient wants to die, I guess.

champagnesupernova3  FA says you cant assist suicide but you can prescribe pain medication which they can conveniently overdose on
dickass  "Physicians may, however, prescribe medically appropriate analgesics even if they shorten the patient's life." (wink, wink) It's vague, but I guess the main point is to let the patient have relief, side effects no longer important. I still don't think you can just give the patient a bottle of benzos though.

 +1  (nbme20#31)

Paclitaxel hyperstabilizes polymerized microtubules (made up of alpha- and beta- tubulin)

md_caffeiner  And clinical use is in breast and ovarian CA (FA19 433)

 +1  (nbme20#41)

FA pg 567:

Congenital solitary functioning kidney: Condition of being born with only one functioning kidney. Majority asymptomatic with compensatory hypertrophy of contralateral kidney, ...


 +0  (nbme20#9)

Remember kids, GFR corresponds with Salt (mineralocorticoids), Sugar (glucocorticoids), and Sex (androgens).


 +0  (nbme20#37)

FA pg 70:

Vit E deficiency:

Neurologic presentation may appear similar to vitamin B12 deficiency, but without megaloblastic anemia, hypersegmented neutrophils, or  serum methylmalonic acid levels.

dickass  and VitB12 neurologic symptoms are described on pg 518

 +1  (nbme20#1)

Testicles have significant aromatase activity. This enzymatic activity is regulated by LH (and of course bHCG)

https://www.ncbi.nlm.nih.gov/pubmed/9267128


 +0  (nbme20#4)

It can't be the Facial nerve, physical examination was normal. Someone would probably notice the face symptoms.

I went with Glossopharyngeal, but that wasn't it.


 +0  (nbme20#35)

I spent like 5 minutes trying to figure out what kind of trick question this was. They're just trying to get you to figure out 'oh look the spleen is YUGE!'





Subcomments ...

submitted by dickass(13),

Nonmaleficence: “Do no harm.”

Even if the patient wants to die, I guess.

champagnesupernova3  FA says you cant assist suicide but you can prescribe pain medication which they can conveniently overdose on +  
dickass  "Physicians may, however, prescribe medically appropriate analgesics even if they shorten the patient's life." (wink, wink) It's vague, but I guess the main point is to let the patient have relief, side effects no longer important. I still don't think you can just give the patient a bottle of benzos though. +  


submitted by hayayah(416),

Frontotemporal dementia (formerly known as Pick disease): Early changes in personality and behavior (behavioral variant), or aphasia (primary progressive aphasia). May have associated movement disorders (eg, parkinsonism).

While this presents very similiarly to Hungtington's, you can differentiate it because in this stem it says "atrophy of the frontal lobes bilaterally" whereas Huntington's has atrophy of caudate and putamen with ex vacuo ventriculomegaly.

dickass  and the patient has no chorea +  


submitted by hayayah(416),

Patient has a craniopharyngioma. Most common childhood supratentorial tumor. Derived from remnants of Rathke pouch (oral ectoderm). Calcification is common. Cholesterol crystals found in “motor oil”-like fluid within tumor.

A cystic suprasellar mass with calcifications and enhancement of the wall or solid portions in a child or adolescent is almost always a craniopharyngioma.

May be confused with pituitary adenoma (both cause bitemporal hemianopia).

dickass  Cholesterol crystals in motor oil +  


submitted by dickass(13),

Got this one wrong because of those 2 unaffected children. Here's the explanation from FA pg 59:

Mitochondrial inheritance - Transmitted only through the mother. All offspring of affected females may show signs of disease.

Variable expression in a population or even within a family due to heteroplasmy.

Heteroplasmy basically means that multiple mitochondria are transmitted to each offspring. Their ratio may change at each generation, and cause more severe or less severe disease, even within the same family.

Those unaffected dudes lucked out.

dickass  That'll teach me not to skim FA, you really gotta look up the words you don't know. +  
chandlerbas  heteroplasmy is a fancy way of saying variable expressivity just specific to mitochondrial diseases i do declare +  


submitted by hayayah(416),

Oxytocin uses IP3 signaling pathway.

GnRH, Oxytocin, ADH (V1-receptor), TRH, Histamine (H1-receptor), Angiotensin II, Gastrin.

FA mnemonic: "GOAT HAG"

dickass  I figured "if Oxytocin can cause milk secretion and enough uterine contractions to expel a full baby, it's probably activating smooth muscle contraction through Gq coupled second messengers" +1  


submitted by hayayah(416),

This patient has small cell carcinoma. This type of cancer is associated with paraneoplastic syndromes such as: Cushing Syndrome, SIADH, or antibodies against Ca2+ channels (Lambert-Eaton) or neurons. Amplification of myc oncogenes is also common.

SIADH (Syndrome of inappropriate antidiuretic hormone secretion) is characterized by:

  • Excessive free water retention
  • Euvolemic hyponatremia with continued urinary Na+ excretion
  • Urine osmolality > serum osmolality

Body responds to water retention with aldosterone and ANP and BNP. That is what causes the increased urinary Na+ secretion Žwhich leads to normalization of extracellular fluid volume Žand the euvolemic hyponatremia.

hello  Why would body respond to water retention with ALDO? ALDO would increase water retention... +2  
nala_ula  @hello, the body's response is to decrease Aldosterone since there is increased volume retention and subsequently increased blood pressure. This concept confused me a lot, but I ended up just viewing it as separate responses. First, the increased volume retention leads to increase ANP and BNP secretion that lead to decreased Na+ reabsorption in the tubules (page 294 in FA 2019) and second, this increased volume basically leads to increased pressure so lets also decrease aldosterone so there is no Na+ retention (since water comes with it)... I thought it was counterintuitive to secrete so much Na+ since you're already having decreased serum osmolality (decreased Na+ concentration) because of the water retention, but I'm guessing that this is just another way our body's well intentions end up making us worse XD +6  
compasses  see page 344 FA2019 for SIADH. +  
dickass  author pasted text straight from FA but the arrows didn't copy over, inverting the original meaning +  
medninja  The idea of increasing urine Na is getting rid of water, thats why this mechanism end increasing urine Na secretion even when there are very low serum Na levels. +  


submitted by dr_jan_itor(14),

Can anyone answer why this one can't be F. Beta thalasemia major? I was thinking becaues of his anemia and the "european descent" which includes the mediteranian europeans. Unless NMBE writers think that european only means the ones with extra white people lol

dickass  European implies northern european (they even specified the patient was a person of pallor), mediterranean descent is usually implied by country of origin or by straight-out writing 'mediterranean'. +  
poisonivy  The MCV is normal, thalassemias are microcytic anemias, that hint helps to rule out the thalassemias. However, I got it wrong, not sure why it cannot be a homozygous mutation in the ankyrin gene +  


submitted by jotajota94(9),

Use the Hardy-Weinberg equation

  1. Take the square root of 1/1600, and that will give you the frequency of the recessive allele = 1/40.
  2. Calculate the frequency of the dominant allele with p+q=1, which is p= 0.975.
  3. They are telling you to calculate the frequency of the disease carriers, which is with the equation 2pq.
  4. They want only the disease carriers in which deletion is present. To calculate this, use the q value (1/40) and multiply by 80% in this should give you 0.02.
  5. Finally, calculate for 2Pq 2 (0.975)(0.02)= 0.04 = 1/25.
yex  Nice! ...and we are supposed to read the stem and do all this in a minute or so? :-/ +3  
charcot_bouchard  Allele frequency 1/40. so carrier freq 1/20. 80% of 1/20 is 1/25 (80/100 x 1/20) +4  
dickass  Ah feck, 2pq got me +  


submitted by breis(11),

Patient has Midsystolic murmur heard at the cardiac apex. there is also a LEFT ATRIAL abnormality. Echo shows LEFT ATRIUM is enlarged.

Mid systolic... enlarged left atrium...

Best choice: Mitral Regurg

hpsbwz  Why is it regurg instead of stenosis? +2  
minhphuongpnt07  Vague question requires a lot clinical reasoning. mitral regurgitation: holosystolic murmur( this cv: midsystolic), enlarged LA, LV Mitral stenosis: diastolic murmur, enlarged LA, normal LV. only best explanation I can think of: early stage Mitral regur, that's why the murmur is not holosystolic but midsystolic and LV still adequately handle the situation +1  
dickass  @hpsbwz it's regurgitation because the murmur is SYSTOLIC, when the mitral valve is not supposed to make any sound. mitral valve leaks in systole, which causes blood to back up, which causes the left atrium to work harder and eventually hypertrophy. Mitral stenosis would be a DIASTOLIC sound, which is when the left atrium normally contracts. +2  


submitted by hayayah(416),

Familial adenomatous polyposis is an autosomal dominant mutation. Thousands of polyps arise starting after puberty; pancolonic; always involves rectum. Prophylactic colectomy or else 100% progress to CRC.

Autosomal dominant diseases have, on average, 50% chance of being passed down to offspring.

sympathetikey  I would say this is Lynch Syndrome (APC is usually thousands of polyps) but lynch syndrome would generally have a family history of other cancers as well, so you might be right. Either way, both autosomal dominant so win win. +1  
smc213  uptodate states: Classic FAP is characterized by the presence of 100 or more adenomatous colorectal polyps +  
dickass  @sympathetikey Lynch Syndrome is literally called "Hereditary NON-POLYPOSIS colorectal cancer" +1  


submitted by dickass(13),

FA pg 70:

Vit E deficiency:

Neurologic presentation may appear similar to vitamin B12 deficiency, but without megaloblastic anemia, hypersegmented neutrophils, or  serum methylmalonic acid levels.

dickass  and VitB12 neurologic symptoms are described on pg 518 +  


submitted by nwinkelmann(104),

This explains it really well with a picture: https://www.med.illinois.edu/m2/pathology/PathAtlasf/Atlas01.html.

Hydropic change = one of the early signs of cellular degeneration in response to injury that results in accumulation of water in the cell. Hypoxia/ischemia leads to decease in aerobic respiration in the mitochondria and decreased ATP production due to failure of the Na+/K+ ATPase leading to Na+ and water diffusion into the cell. Individual tubule cells appear swollen and "empty" with almost occluded lumen, glomerulus is hypercellular.

dickass  it's basically from pathoma chapter 1: cellular injury causes swelling +1  
md_caffeiner  @dickass you why arent you on every q stem? +  


submitted by step420(18),

B-HCG and LH,FSH,TSH share same alpha subunit, so HCG can activate those receptors if its in high enough quantity. Activating LH receptor will lead to more Testosterone from the Leydig cells. More testosterone can lead to more estrogen formation via aromatase.

dickass  bHCG directly increases testicular aromatase activity, it's not because of the increased amount of testosterone. +1  


submitted by medbitch94(10),

WHY she has a huge ass liver too? I don't understand how you can choose big spleen over big liver or visa versa

dickass  I like big spleens and I can not lie~ +1  


submitted by step420(18),

This is mullerian agenesis. Normal ovaries but absent uterus.

endochondral   why not androgen insensitivity? +  
shaeking  I was wondering the same thing because doesn't androgen insensitivity also have normal female secondary characteristics. Was it the levels of hormones because she doesn't have abnormally high testosterone? +  
swb  Androgen insensitivity has the same presentation and symptoms. What's the clue that it is mullerian agenesis instead ? +  
sugaplum  Testosterone would be high if it was androgen insensitivity FA 2019 Pg 625 +2  
charcot_bouchard  Testo would be high in AIS. in AIS pubic hair, axillary hair doesnt devlop because of androgen insensitivity. both have normal breast dev and primary amenorrhea +  
dickass  This is not androgen insensitivity because she has perfectly normal Estradiol, which means she has perfectly normal ovaries. She also has regular female levels of testosterone. +1