NBME 22 Carboxylation of precursor proteins (NBME Answers)

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Retired NBME 22 Answers

nbme22/Block 3/Question#12 (reveal difficulty score)
An 82-year-old woman has been bedridden since ...
Carboxylation of precursor proteins 🔍 / 📺 / 🌳 / 📖
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submitted by ∗humble_station(85)

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Warfarin inhibits Vit K dependent synthesis of factors & proteins.

Vit K is necessary for the maturation of clotting factors II, VII, IX, X and protein C & S

So a drug that can inhibit the carboxylation of precursor proteins or in other words inhibit the maturation of the clotting factors will decrease the risk of thrombosis in this patient.

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Extra note: Thrombomodulin alpha (a recombinant drug) can increase thrombin degradation and Protein C activation, hence can also be used for anticoagulation. (But this question asked about decrease in which of the following)

+3/- apurva(101)

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submitted by ∗haliburton(224)

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warfarin inhibits the synthesis of factors II, VII, IX, X, C, and S by blocking reduction of oxidized vitamin K. The enzyme Epoxide Reductase is inhibited by warfarin. The reduced (active) form of vit. K is a cofactor for gamma-glutamyl carboxylase.

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link981 So factors II, VII, IX, and X are precursor proteins? GTFO +2

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submitted by ∗humble_station(85)

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Warfarin inhibits Vit K dependent synthesis of factors & proteins.

Vit K is necessary for the maturation of clotting factors II, VII, IX, X and protein C & S

So a drug that can inhibit the carboxylation of precursor proteins or in other words inhibit the maturation of the clotting factors will decrease the risk of thrombosis in this patient.

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ajss this is why warfarin is given as prophylaxis after this type of surgeries +

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submitted by ∗sup(31)

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Why not PGI2 by way of ASA? Especially given other answer choices of proteins C + S: doesn't warfarin also suppress these?

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imnotarobotbut Protein C and S are ANTI-thrombotic, so although Warfarin does decrease them, they wouldn't decrease the patient's risk for thrombosis +1

epr94 the question ask "suppression" of which one will decrease risk of thrombosis if you suppress C and S which and anti-thrombotic you get thrombotic +3

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