The bone marrow fibrosis observed in primary myelofibrosis is due to:
a. Malignant proliferation of fibroblasts
b. Increased erythropoietin, which stimulates fibroblast proliferation
c. Increased release of fibroblastic growth factors such as platelet-derived growth factor
d. Decreased apoptosis of normal fibroblasts
ANS: C
An increased release of fibroblastic growth factors occurs, including platelet-derived growth factor, in primary myelofibrosis; this results in fibrosis. The fibroblasts in primary myelofibrosis are normal, not malignant.
You might also like to view...
Because only the necessary resources are sent on each call, priority dispatching has which of the following benefits?
A) Minimizes responder responsibilities B) Saves time and money C) Reduces patient anxiety D) Keeps dispatchers alert
Which of the following is not a type of digital image receptor?
A) Photostimulable phosphor (PSP) plate B) Scanner C) Complementary metal oxide semiconductor active pixel sensor (CMOS-APS) D) Charge-coupled device