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Comments ...

 +0  (nbme22#45)

in NBME 20 there is a question where a pt starts taking an antitussive and has constipation. The offending drug was dextro.... confusing, man...

 +0  (nbme21#24)

I know that small cell carcinoma wasn't an option in this question, but would there be any possible way to distinguish small cell from squamous cell on this specific gross pathology?

Subcomments ...

submitted by mcl(454),

Pronator teres and quadratus are both supplied by median nerve (C5/C6/C7/C8/T1, so that's not super helpful.) Extension of the forearm is radial nerve (also C5-T1, also not helpful). This does tell us is it can't be isolated median or radial. Triceps tendon reflex is C7/C8, which narrows it down to these two.

Can anyone explain why it's C7 over C8?

joha961  Same question. How could you determine between the specific nerve roots (C7 vs. C8)? +2  
mcl  Someone I was talking to (and post below) was saying that first aid mentions triceps is C7, so that's what should've been the big thing for us. +1  
joanmadd  you might see some ulnar nerve involvement if C8 was involved her +  

submitted by hayayah(884),

Missense mutations involve a nucleotide substitution resulting in changed amino acids. Sometimes the effects of missense mutations may be only apparent under certain environmental conditions; such missense mutations are called conditional mutations. Many missense mutations result in proteins that are still functional, at least to some degree.

Also, all the other answers would probably leave you with either a greatly altered or non-functional protein.

thefoggymist  I chose nonsense because I thought it'll make the enzyme shorter (since less bonds = more heat liable = can't work at 42 degrees) but yea, probably won't work even at 30 if it's an early nonsense. +1  
joanmadd  A good clinically related example is HbC disease on electrophoresis. HbC disease is due to a missense mutation (glutamic acid (-) for valine (neutral)). The mutated hemoglobin is still fairly functional but when placed on gel electrophoresis the HbC migrates the least far from the negative electrode due to less negative propulsion (lack of wild type glutamic acid). +1  

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