couple practice questions

[rahulb]

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a 9 yr old boy has had anorexia for 4 weeks following chemotherapy for ALL. he is brought to the ED by his mother when he develops a staggering gait and confused, disoriented speech. he receives a standard glucose solution for rehydration; however his symptoms rapidly become worse. they include depressed consciousness, irregular respiration, and opthalmoplegia. based on his history, which enzyme is most likely deficient in this patient.

a. homocysteine methyltransferase
b. lysyl hydroxylase
c. propionyl-CoA carboxylase
d. thymidylate synthase
e. transketolase

a 65 yr old man with a 2 month history of progressively worsening cough, which during the last week has been productive of bloody sputum. on questioning, the patient also states that he has been short of breath. the man has a 30 pack yr smoking history. ct scan demonstrates a 5cm mass adjacent to his right main bronchus. transbronchial biospy demonstrates a malignant tumor composed of islands of darkly basophilic small cells. areas of necrosis are present. immunohistochemical staining of this tumor would most likely be positive for which of the following?

a. AFP
b. endomysial antibody (EMA)
c. hCG
d. neuron-specific enolase (NSE)
e. spinal muscle actin (SMA)

a medical laboratory isolates a new dsDNA virus that is sensitive to alcohol. what is the most likely means by which this virus would be transmitted in nature?

a. arthropod
b. fecal/oral
c. respiratory droplet
d. sexual/parenteral
e. transplacental

a biotech company is investing the potential for development of a vaccine against a new emerging pathogen. which of the following is most likely to be associated with the requirement for a live attenutated vaccine?

a. dna virus
b. enveloped virus
c. helical virus
d. icosahedral virus
e. naked virus
f. rna virus
g. syncytial virus


input appreciated 👍

 

[tdd340]

eddg, just quickly off the top of my head

 

[Cliff Huxtable]

D d c e ?

 

[tdd340]

The first one is pretty classic for thiamine deficiency, rapid decline after glucose infusion, and transketolase is the only one of the choices that uses thiamine. As for 3, its an enveloped virus so parenteral transmission is most likely

 

[rahulb]

The first one is pretty classic for thiamine deficiency, rapid decline after glucose infusion, and transketolase is the only one of the choices that uses thiamine. As for 3, its an enveloped virus so parenteral transmission is most likely

ECDG 👍

however i still can't figure out why #2 is C

 

[njshibby]

ECDG 👍

however i still can't figure out why #2 is C

pretty sure the small cell one is enolase, it's a neuroendocrine marker.
can someone explain #4?

 

[rahulb]

pretty sure the small cell one is enolase, it's a neuroendocrine marker.
can someone explain #4?

i picked enolase and got it wrong..

 

[sendwich]

I thought enolase at first too but maybe they're referring to ACTH? doesn't it have the same alpha-subunit as hCG?

 

[Cliff Huxtable]

I thought enolase at first too but maybe they're referring to ACTH? doesn't it have the same alpha-subunit as hCG?

TSH, FSH, and LH have the same alpha subunit

 

[rahulb]

TSH, FSH, and LH have the same alpha subunit

hCG and TSH also share a common subunit. thats why you can see features of hyperthyroidism in conditions like choriocarcinoma

 

[sendwich]

then what explains #2 C?

btw, OP where are these q's from? just curious..