NBME Answers : step1forthewin's page

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+1 visit this page (nbme24#5)

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Can someone please clarify the answer. Is decreased adherence same as decreased aggregation? Wouldn;t inhibition of the IIb/IIIa receptor prevent aggregation?

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xxabi I'm not completely sure...but I think its because its aspirin, and aspirin doesn't work on IIb/IIIa receptors. That's why i picked decreased adherence of platelets, figured that was the closest thing to decreased aggregation that still made sense with aspirin's mechanism of action. Hope that helps! +2

ihavenolife Aspirin irreversibly inhibits COX which leads to decreased TXA2. TXA2 normally is a vasoconstrictor and induces platelet aggregation, so aspirin inhibits platelet aggregation by downplaying TXA2 not by interacting with IIb/IIIa receptor. (Source FA and UWorld) +22

fallenistand In this case, inhibition of COX-1 by aspirin will also reduce the amount of precursors for vascular prostacyclin synthesis, provided, for example, from adhering platelets https://www.ncbi.nlm.nih.gov/pubmed/9263351 +1

niboonsh inhibition of IIb/IIIa receptor is the moa of a completely separate class of drugs - Glycoprotein IIb/IIIa (abciximab, eptifabide, tirofiban) +1

t123 Bad question - TXA2 upregulates GpIIb/IIIa on platelets. So aspirin inhibits their expression. +1

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submitted by lispectedwumbologist(122), visit this page

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

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lispectedwumbologist Nevermind I'm stupid as fuck I see my mistake +2

drdoom be kind to yourself, doc! (it's a long road we're on!) +21

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 +25

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... +9

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 +2

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. +4

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. +6

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. +5

zevvyt so i guess size is more important than color cause those are hypochromatic as fuck +

yesa The NUCLEUS of a lymphocyte should be the same size as a normal RBC, which is not the case here. Under normal circumstances RBCs are not as big as lymphocytes, so this is truly extraordinary = megaloblastic anemia. +1

weirdmed51 @yesa you mean ‘macrocytic’. For it to be ‘megaloblastic’ there had to be a hypersegmented neutrophil. +