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qbnak q

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13 Posts

malinda
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01/10/06 - 04:11 PM

<25>A 32-year-old TV cameraman complains of weakness and blurred vision.
He notes that these symptoms are typically worsened with effort and
improve with rest. Physical examination is remarkable for ptosis and
weakness of limb muscles on repetitive testing. What is the mechanism
of action of the agent that is commonly prescribed for the long-term
amelioration of these symptoms?
A. Carbamylation of acetylcholinesterase
B. Competitive inhibition of acetylcholinesterase
C. Dephosphorylation of acetylcholinesterase
D. Direct muscarinic receptor agonist
E. Direct muscarinic receptor antagonist
F. Direct nicotinic receptor agonist
G. Direct nicotinic receptor antagonist
H. Phosphorylation of acetylcholinesterase

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msyamp
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01/10/06 - 04:35 PM

Edited by msyamp on 01/10/06 - 06:09 PM

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Geroo
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01/10/06 - 05:56 PM

msyamp
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01/10/06 - 06:09 PM

geroo thnax maan you are always right

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mjl1717
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01/10/06 - 06:15 PM

My reflex response is answer-b, but Id go with pyridostigmine answer g would be mecamylamine or hexamethonium or defunct trimethophan. I believe neostigmine and physostigmine have the carbamylated linkage.

Edited by mjl1717 on 01/10/06 - 06:28 PM

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Geroo
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01/10/06 - 07:58 PM

B.is edrophonium short acting competitive inhibitor
C.is pralidoxime
H.is organophosphates

msyamp
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01/10/06 - 08:53 PM

d acetylcholine
e atropine
f nicotine
g. succhynyl choline.
wink

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Geroo
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01/10/06 - 08:55 PM

i thought that everyone knows (d,e,f,g )hat's why i didn't mention them. grin

msyamp
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01/10/06 - 08:59 PM

hey dont underestimate fellas they know the answer too and all other choices ncludig abcdh.

they dont say it out. we doo cool

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kishore80
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01/10/06 - 09:07 PM

#10

hahahahaa. msyamp ur good not only at explanations but also at reading peoples minds.. a very good doc in the making. nod

malinda
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01/11/06 - 08:34 AM

#11

thanx for the answers smiling face

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mjl1717
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01/11/06 - 11:29 AM

#12

Every book I look at categorizes Succinylcholine as a depolarizing neuromuscular blocking agent (that is biphasic) Only in the 2nd phase does it function like d-tubocurarine

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msyamp
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01/11/06 - 12:25 PM

#13

yes it does function like dtc. first phase it exhaust all acetyl choline and second phase it has no more ach so it acts as if it is a nondepolarising blocker

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