Test 175 (Miscellaneous)

1. Amyloid: 

a. is a a-pleated sheet structure protein.

b. can occur from overproduction of immunoglobulin light 
    chain

c. is found within the cellular cytoplasm

d. can occur in the vitreous in the absence of systemic 
    amyloidosis

e. is the structure found in lattice dystrophy of the cornea
 

Answera.F   b.T  c.F   d.T  e.T
Amyloid is a beta-pleated sheet structure protein.

2. Cytokines include:

a. interleukins

b. interferon

c. arachidonic acid

d. tumour necrosis factor

e. bradykinin
 

Answera.T  b.T  c.F  d.T  e.F
Interleukins mediate leukocyte interaction. Interferon inhibits viral replication. Tumour necrosis 
factor kills tumour cells. Arachidonic acid is the precursor for thromboxane and prostaglandins. Bradykinin is a powerful vasodilator and causes increased vascular permeability.
 
 

3. The following are true about tumour suppressor genes:

a. they encode proteins that positively regulate cell growth

b. P53 is a tumour suppressor gene found on 
    chromosome 17

c. P53 triggers apoptosis and cell cycle arrest

d. RB1 is a tumour suppressor gene located on 
    chromosome 13

e. they function like proto-oncogenes
 

Answer
a.F   b.T  c.T  d.T  e.F
Tumour suppressor genes encode proteins that 
negatively regulate cell growth whereas proto-oncogenes encode proteins that positively regulate cell growth.

 

. 4. The following topical medications are contraindicated in iritis

a. pilocarpine

b. atropine

c. latanoprost

d. b-blockers

e. acetazolamide
 

Answer
a.T  b.F  c.T  d.F  e.F
Both pilocarpine and latanoprost can increase ocular inflammation.

5. With regard to valaciclovir:

a. it is the L-valine ester prodrug of acyclovir

b. it is absorbed than acyclovir from the gut

c. it is less effective than acyclovir in the treatment
    of herpes zoster ophthalmicus

d. it causes DNA chain termination in herpes virus

e. it is effective in treating adenoviral keratitis
 

Answer
a.T   b.T  c.F  d.T  e.F
Valaciclovir is a prodrug of acyclovir. It has better 
absorption from the gut than acyclovir. It is as effective as acyclovir in the treatment of herpes zoster ophthalmicus. It is only effective in the treatment of herpeviruses.

 

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