General Pathology USMLE Step 1 Practice Question
A 12 year old boy receives radiation therapy for a malignant brain tumor. Two days later, a biopsy from nearby irradiated tissue shows shrunken eosinophilic cells with chromatin condensation and membrane bound apoptotic bodies but little surrounding inflammation. Which of the following molecular events most directly mediates this form of cell death through the intrinsic pathway?
Answer choices
- AInhibition of p53 at the G1 to S checkpoint
- BUpregulation of selectins on endothelial cells
- CActivation of phospholipase A2 leading to arachidonic acid production
- DActivation of BAX with release of cytochrome c from mitochondriaCorrect answer
- EDeposition of immune complexes in vessel walls
- FActivation of caspase-8 through Fas-Fas ligand binding
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