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 +1  (nbme24#6)

How does one differentiate factitious disorder from being thirsty w poor impulse control?

therealslimshady  If you're asking how to rule out diabetes insipidus, I think it's because: Diabetes insipidus is caused by a lack of ADH effect, so they will be peeing out too much water, thus making them dehydrated and hyperosmolar (thirsty). This CHF patient is presenting with signs of fluid overload

 +0  (nbme24#4)

ALL YOU HAVE TO DO is remember that last time they used this picture D & E were CNs VII & VIII, so anything else on the right side or down from there could be the right CN X.

 +0  (nbme23#17)

I'd never heard of an accessory spleen and spent like 4 minutes talking myself into this one as it would explain the findings much better than the other options.

 +4  (nbme23#8)

B1-selective antagonists start with a letters A-M & end in -olol.

  • acebutolol, atenolol, betaxolol, bisoprolol, esmolol, metoprolol

Nonselective antagonists (B1=B2) start with letters N-Z & end in -olol.

  • nadolol, pindolol, propanolol, timolol

Nonselective alpha & beta antagonists end in -ilol or -alol

  • carvedilol

  • labetalol

Source: FA 20 p245

focus  The mneumonic for B1 selective antagonists: "A BEAM"

 +3  (nbme23#13)

I got thrown off thinking about nitric oxide synthesis occurring in the endothelial cells and NO diffusing to nearby smooth muscle cells. This does occur, though the cGMP the question asks about is a downstream effect of the NO in the smooth muscle cell.

mdmikek89  Its the action of PDE inhibitors. They inhibit PDE = increase cyclic compounds. Doesn't effect NO.

 +5  (nbme23#6)

To remember the 4 degrees of perineal tears, you have to remember that.... when giving birth, vaginal tears are PAR for the course.

  • Vagina
  • Perineum
  • Anal sphincter
  • Rectum

 +2  (nbme23#46)

I just remember my wife was paranoid that our baby was going to get measles because he couldn't get the (live attenuated) MMR vaccine before 1 yo.

Now you have an excuse to put down your computer and go make some babies.

 +1  (nbme23#33)

Both parents have alpha-thalassemia trait. Given they are Asian, they will have the cis-mutation. That is, each parent will have 1 chromosome 17 with 0 alpha chain genes + another chromosome 17 with 2 alpha chain genes).

Thus, each parent can pass on either 0 or 2 copies of the alpha chain gene. So, the offspring will have a

  • 25% chance of having 0 alpha chains (causing hydrops fetalis & death in utero),
  • 50% chance of having 2 alpha chains (alpha-thal trait, answer choice D), and a
  • 25% chance of having 4 alpha chains (normal).

A) Hemoglobin H is when there is 1 alpha chain, so that is not possible.

B, C, D) Both parents had normal hemoglobin electrophoresis, so Hb S, HbSC, and B-thal are not possible.

rockodude  *alpha chain is on chromosome 16, beta chain is on chromosome 11

 +1  (nbme23#6)

The personality disorder is always borderline if it's a suicide attempt after a breakup.

 +0  (nbme22#29)

Rule of thumb:

Amphotericin B is the "Big gun" for serious/systemic fungal infections.

It works by binding to ergosterol in the membrane.

 +0  (nbme22#5)

RNA depended DNA polymerase = reverse transcriptase (FA 20 p 38, under telomerase).

Given the virus has reverse transcriptase, it is likely a retrovirus (hepadnavirus also has reverse transcriptase).

Retroviruses are SS+ RNA viruses (FA 20 p 167)

 +0  (nbme22#39)

According to UW, contact dermatitis can be CD4+ and/or CD8+ T cell mediated, with urushiol (poison ivy) dermatitis being primarily mediated by CD8+ T cells.

Subcomments ...

Metformin is awesome. It decreases hepatic glucose production, decreases intestinal absorption of glucose, and improves insulin sensitivity by increasing peripheral glucose uptake and utilization.

drschmoctor  And it dramatically increases lifespan in experimental animals! Human trials in progress! +2  

submitted by m-ice(233),

Question is basically asking what are the substrates used the first step in heme synthesis. In that step, glycine and succinyl CoA are combined to make aminolevulinic acid.

sunshinesweetheart  p 417 FA 2019 +  
drschmoctor  p 425 FA2020 +  

submitted by brethren_md(73),

Transfusion-related acute lung injury (TRALI) is a rare but serious syndrome characterized by sudden acute respiratory distress following transfusion. It is defined as new, acute lung injury (ALI) during or within six hours after blood product administration in the absence of temporally-associated risk factors for ALI.

drschmoctor  Neutrophils sequestered in recipient lung are triggered by donor antigen (e.g., anti leukocyte IgG), which causes release of cytokines, inflammation party in the lungs. +2  

Why would it not be anemia of chronic disease with decreased serum transferrin concentration?

lispectedwumbologist  Nevermind I'm stupid as fuck I see my mistake +  
drdoom  be kind to yourself, doc! (it's a long road we're on!) +11  
step1forthewin  Hi, can someone explain the blood smear? isn't it supposed to show hypersegmented neutrophils if it was B12 deficiency? +1  
loftybirdman  I think the blood smear is showing a lone lymphocyte, which should be the same size as a normal RBC. You can see the RBCs in this smear are bigger than that ->macrocytic ->B12 deficiency +15  
seagull  maybe i'm new to the game. but isn't the answer folate deficiency and not B12? Also, i though it was anemia of chronic disease as well. +  
vshummy  Lispectedwumbologist, please explain your mistake? Lol because that seems like a respectible answer to me... +1  
gonyyong  It's a B12 deficiency Ileum is where B12 is reabsorbed, folate is jejunum The blood smear is showing enlarged RBCs Methionine synthase does this conversion, using cofactor B12 +  
uslme123  Anemia of chronic disease is a microcytic anemia -- I believe this is why they put a lymphocyte on the side -- so we could see that it was a macrocytic anemia. +  
yotsubato  Thanks NBME, that really helped me.... +1  
keshvi  the question was relatively easy, but the picture was so misguiding i felt! i thought it looked like microcytic RBCs. I guess the key is, that they clearly mentioned distal ileum. and that is THE site for B12 absorption. +4  
sahusema  I didn't even register that was a lymphocyte. I thought I was seeing target cells so I was confused AF +  
drschmoctor  Leave it to NBME to find the palest macrocytes on the planet. +3  

yb_26  @at0xibolic, I think you won this competition on finding better picture lol thanks +4  
drschmoctor  Those may be better, but this is the BEST. http://bitly.com/98K8eH +3  
brotherimodu  god damnit +  
jesusisking  Not again (´∀`) +  

submitted by mcl(447),

lolol so instead of using fomepizole they just gonna get him real drunk

johnson  yep - supposedly, ethanol is used when a hospital/facility doesn't have fomepizole. +4  
usmlecrasherss  Drink vodka man , either way you're dying +  
drschmoctor  Or if you really wanna get drunk and have a warm place to sleep, drink a bunch of methanol in the waiting room of the ED, then let them pump you full of ethanol and keep you safe. +  

submitted by sugaplum(153),

always remember them in order with formula, SITS=AEEI
and the two on the END are AD-DUCTION

makinallkindzofgainz  The supraspinatus AB-ducts. The Subscapularis ADDucts +  
makinallkindzofgainz  disregard my comment, I misread what you meant +  
drzed  How are you supposed to remember which S is which? +1  
drschmoctor  @drzed "Supra" = on top, so the 1st S is for supraspinatus. +  
usmleaspirant2020  according to Physeo : INFraspinatus--EXternal rotaTION------INF-ECTION +  

submitted by sympathetikey(743),

Seminoma is the most common testicular tumor. It's a germ cell tumor. Commonly see "fried egg cells".

motherfucker2  If it was a woman would be a dysgerminoma. Seminomas have excellent prognosis and highly radiosensitive. MCC testicular tumor +4  
drschmoctor  Spunky fun fact: In a normal adult male >1,000 sperm are made per heartbeat. +3  

submitted by mousie(134),

Cholera = Fecal oral /Legionnaires = Legonalla pneumo = NO person to person only by inhalation of bacteria contaminated water /Lyme = tick bite /Meningiococcal = sharing respiratory and throat secretions (saliva or spit). Generally, it takes close (for example, coughing or kissing) or lengthy contact to spread these bacteria (CDC) /RMSF = tick bite

smc213  Also, when Meningococcal meningitis is treated ... close contacts are also treated prophylactically whereas the others typically are not. There's also a subunit vaccine for n. meningitis due to high infectivity rate especially in crowded establishments. +5  
dentist  So, Cholera is also p2p but Mening is more likely? +1  
usmlecharserssss  in cholera people to water => water to people +  
qball  Remember the fire sprinklers from Sketchy for M. Meningitis. as respiratory droplets are the easiest to transmit from person to person. +  
drschmoctor  but the poop water comes from people so.... +1  
llamastep1  Respiratory dropplets is easier than fecal-oral tho +  
lowyield  Can also reason that n. meningitidis is common in college students because they live in close quarters which suggests high rate of transmission even amongst immunocompetent individuals +  

Seems like I did what most of you did. I read the "symptom" as pain and went for PGE2.

Turns out if I had just read the 2008 paper Undiscovered role of endogenous thromboxane A2 in activation of cardiac sympathetic afferents during ischaemia I would have known that TXA2 MAY be a cause of MI pain. https://www.ncbi.nlm.nih.gov/pubmed?term=18483073

There are also theories that the pain is from adenosine/bradykinin/acid/ROS/5-HT which you can read about here:

https://www.ncbi.nlm.nih.gov/pubmed?term=10099685 https://www.ncbi.nlm.nih.gov/pubmed?term=10222339 https://www.ncbi.nlm.nih.gov/pubmed?term=11458709 https://www.ncbi.nlm.nih.gov/pubmed?term=12411532

I found these via the UpToDate page Angina pectoris: Chest pain caused by coronary artery obstruction which does say the mechanism is "complex and not entirely understood."

makinallkindzofgainz  this is all irrelevant. the dude is having an MI so the answer is Thromboxane A2 +  
drschmoctor  Bruh, you gotta read all the 2008 papers. It was a fire year for obscure shit you need to know in 2020. +2  

submitted by seagull(831),

out of curiosity, how may people knew this? (dont be shy to say you did or didnt?)

My poverty education didn't ingrain this in me.

johnthurtjr  I did not +1  
nlkrueger  i did not lol +  
ht3  you're definitely not alone lol +  
yotsubato  no idea +  
yotsubato  And its not in FA, so fuck it IMO +1  
niboonsh  i didnt +  
imnotarobotbut  Nope +  
epr94  did not +  
link981  I guessed it because the names sounded similar :D +10  
d_holles  i did not +  
yb_26  I also guessed because both words start with "glu"))) +14  
impostersyndromel1000  same as person above me. also bc arginine carbamoyl phosphate and nag are all related through urea cycle. +  
jaxx  Not a clue. This was so random. +  
wolvarien  I did not +  
ls3076  no way +  
hyperfukus  no clue +  
mkreamy  this made me feel a lot better. also, no fucking clue +1  
amirmullick3  My immediate thought after reading this was "why would i know this and how does this make me a better doctor?" +5  
mrglass  Generally speaking Glutamine is often used to aminate things. Think brain nitrogen metabolism. You know that F-6-P isn't an amine, and that Glucosamine is, so Glutamine isn't an unrealistic guess. +2  
djtallahassee  yea, I mature 30k anki cards to see this bs +3  
taediggity  I literally shouted wtf in quiet library at this question. +1  
bend_nbme_over  Lol def didn't know it. Looks like I'm not going to be a competent doctor because I don't know the hexosamine pathway lol +1  
drschmoctor  Is it biochemistry? Then I do not know it. +2  
snoochi95  hell no brother +  
roro17  I didn’t +  
bodanese  I did not +  
hatethisshit  nope +  
jesusisking  I Ctrl+F'd glucosamine in FA and it's not even there lol +  
batmane  i definitely guessed, for some reason got it down to arginine and glutamine +1  
waterloo  Nope. +  
monique  I did not +  
issamd1221  didnt +  
baja_blast  Narrowed it down to Arginine and Glutamine figuring the Nitrogen would have to come from one of these two but of course I picked the wrong one. Classic. +  
amy  +1 no idea! +  

submitted by seagull(831),

THis question is just critical thinking. The adrenals are bilaterally and symmetrically small. All other answer choices are not likely to be even bilaterally. Cancer won't equally spread in perfect symmetry nor infectious causes while maintaining the adrenal architecture.

slim23shady  Will TB be the answer if they'd mentioned the patient from developing world? +  
step1soon  Autoimmune adrenalitis aka addisons disease → adrenals atrophy common cause: 1. developing world: TB 2. Western world:autoimmunne FA 2019 page 334 +7  
drschmoctor  FA 2020 p 349. +  
drzed  I think the cancer reference (C) was with respect to an ACTH secreting tumor, which would symmetrically and bilaterally HYPERTROPHY the adrenals +1  
drzed  ^Just kidding, it says metastatic. My bad! +1  

submitted by joha961(34),

Maintenance dose = (Css * CL * t) / F

... where t is elapsed time between doses (not relevant here since it’s continuous infusion) and F is bioavailability (which is 100% or 1.0 here because it’s given IV).

​Contrast with loading dose:

(Css * Vd) / F

... where Vd is volume of distribution.

yotsubato  So do we just have to memorize this... +6  
gh889  yep +9  
drschmoctor  @yotsubato Not necessarily. I can't remember a formula to save my life. The Css is the amount you want in the blood. The clearance is the fraction removed per unit time. Since we want to maintain a steady state, we only need to replace what is removed. Thus, maintenance dose = amount present * fraction removed. +4  
mambaforstep  https://www.youtube.com/watch?v=gnqOUmNhmdg good & short explanation +  
castlblack  I remember CLoCk Time as in check the clock time to give the next dose Cl = clearance, C = concentration and T = half life. I have never had to use F. +1  
baja_blast  This is on p. 233 in FA 2019. +  

Lifting head while prone: 1 month Social smile: 2 months Cooing: 2 months

pg32  Where do you guys learn that cooing starts at 2 months? It isn't in first aid or boards and beyond so this was an annoying question for me +  
drschmoctor  @pg32 From being a parent! Otherwise little chance I'd remember all these milestones. +3  
drzed  I'll get right on that @drshmoctor :). If only I could have a kid to memorize all these damn developmental milestones. That would make life easier haha. +3  
snripper  Yeah, I don't see cooing anywhere. +  
teepot123  thankfully a lot of my friends on insta keep posting pics/vids of their babies reaching milestones so im well updated lol +  

johnthurtjr  FTR I had no idea this was a thing, and was pretty disappointed in myself when the google search had it in big bold letters right in my face. +3  
drdoom  via @johnthurtjr link: "Testosterone and other androgens have an erythropoietic stimulating effect that can cause polycythemia, which manifests as an increase in hemoglobin, hematocrit, or red blood cell count." https://www.medscape.com/viewarticle/773465 +3  
meningitis  I guess that's another reason for steroids and doping up. +5  
drschmoctor  For once I feel like I've been led astray by Pathoma. My instinct was to go with hemoglobin, but I talked myself out of it after remembering Dr. Sattar saying that the reason why women have lower hemoglobin is due to menstruation. +  
fexx  F U testosterone! and F U NBME 22 question +  

don't be a dick? not really sure what more there is to it. The patient doesn't have any other family so this woman should be considered family

aesalmon  Questions like this usually hinge on asking if you're going to follow the rules or not though, obviously the one asking her to lie and say she was her sister is wrong, but the correct answer is obviously breaking the hospice center's "policy" - presumably if the physician is sending her to hospice then they don't work there so why would the Dr. be able to just tell her its fine? +2  
hungrybox  Yeah, I got this one wrong with the same logic as you, aesalmon. +1  
emmy2k21  I genuinely interpreted this question as though the two women were in a relationship because of the quotes "my close friend". I figured significant others would be allowed to visit simply. Ha seems like I'm the only one who read too far in between the lines! +4  
dr_jan_itor  @emmy2k21 I also thought the quotes implied a lesbian relationship and that the patient was afraid to share this (they grew up at a time when it was heavily stigmatized). So i was thinking, of course you and your "special friend" can stay together. I know this is not just a phase +4  
et-tu-bromocriptine  Anything particularly wrong with A (Don't worry. I'll call you right away...")? It seemed like the most professional yet considerate answer choice. Are we supposed to imply that they're partners based on those quotation marks around "close friend"? Because otherwise it seems like too casual and less professional than A, almost as if it's breaking policy. +4  
lilmonkey  I can swear that I saw this exact same question in UWORLD before. The only reason I got it right this time. +1  
docshrek  @lilmonkey can you please give the QID for the UWorld question? +1  
jakeperalta  Can someone explain to me why following hospital policy is the wrong answer? I'm so lost.And essentially how is this option any different from the last option where he asks her to say its her sister? Both go against hospital policy. Would greatly appreciate some insight yall. +  
jakeperalta  Can someone explain to me why following hospital policy is the wrong answer? I'm so lost.And essentially how is this option any different from the last option where he asks her to say its her sister? Both go against hospital policy. Would greatly appreciate some insight yall. P.s:it struck me as a romantic relationship as well, but it doesn't clear my doubt😓😭 +1  
drschmoctor  @jakeperalta Following the hospital policy is wrong because it would be cruel and unnecessarily rigid to deny a dying woman the comfort of her closest companion. Also, It would be inappropriate to ask the Pt to lie. What's the point of becoming a doctor if you have to follow some BS corporate policy instead of calling the shots and doing right by your patients? +1  

Was just going over Pathoma again and he explanes this concept really well in CH 1, "Free Radical Injury", Section II "Examples of Free Radical Injury"

ultimately cell swelling (the hallmark of acute/reversible injury) = ribosomes off RER = decreased protein synth = decreased Apolipoprotein synth = fat accumulation in cells

drschmoctor  Yes, he does explain very well how both cellular swelling & fat accumulation occur. ... which is exactly why this question is some chicken vs egg BS. +1  

Is this just red-man syndrome? Direct mast-cell degranulation caused by vancomycin....and also morphine?

drschmoctor  Yes, this is red man syndrome. Mast-cell degranulation directly due to Vancomycin: https://www.ncbi.nlm.nih.gov/books/NBK482506/ +  

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