519. A 5-year-old child develops a febrile disease with cough, a blotchy rash, and cervical and axillary lymphadenopathy. Also noted is an erythematous, maculopapular rash behind the ears and along the hairline, involving the neck and, to a lesser extent, the trunk. Examination of this patient's oropharynx would likely reveal which of the following lesions?

 A.  Adherent thin, whitish patch on gingiva 
 B.  Cold sores on the lips 
 C.  Curdy white material overlying an erythematous base on the oral mucosa 
 D.  Large shallow ulcers on the oral mucosa 
 E.  Multiple small white spots on the buccal mucosa 

519. Delta waves of electroencephalogram have frequency of:

1. More than 14 cycles per second. 
2. Between 8 and 13 cycles per second. 
3. Less than 3.5 cycles per second. 
4. Between 4 and 7 cycles per second.

518. Which of the following cell types show abnormal function when there is a history in a young adult of multiple arm and leg fractures following minor falls, with a slight weakness of facial muscles on the left, mild anemia, and with generalized bony widening with partial obliteration of marrow spaces?

 A.  Granulocytic stem cells 
 B.  Megakaryocytes 
 C.  Plasma cells 
 D.  Osteoblasts 
 E.  Osteoclasts