Pathology Flashcards
What protein is overexpressed in follicular lymphoma? [14;18]?
Bcl2 overexpressed -> APAF1 overly inhibited -> APAF1 can’t bind and activate cyt. c -> decreased caspase activation
Full out the rest: DNA dmg -> p53 -> …?
p53 -> BAX/BAK -> Cyt C -> caspases -> execution
mito pw = intrinsic pw; Fas:FasL is extrinsic pw
What does Bcl-2 inhibit?
Cyt C & APAF-1
What is the pathophysiology of fibrinoid necrosis a product of?
Immune complexes combine w/fibrin -> vessel wall dmg
Which part of the heart is most susceptible to ischemia?
Subendocardium (LV)
Which parts of the kidney are most susceptible to ischemia? (2)
PCT (straight part in medulla)
TAL (medulla)
Which liver zone is most susceptible to ischemia?
Zone 3 around central vein
Which parts of the colon are most susceptible to ischemia? (2)
Splenic flexure
Rectum
(watershed)
What is Wallerian degeneration?
Degeneration of axon distal to site of injury (macrophages)
Which pts are usually normocalcemic: those w/dystrophic or metastatic calcification?
Dystrophic calcification
besides calcification [dark], see also small bony tissue and thick fibrotic wall on histo
What part of leukocyte extravasation is defective in leukocyte adhesion def. type 2?
Margination & rolling (decreased Sialyl-Lewis^x on WBCs, binds selectins)
What part of leukocyte extravasation is defective in leukocyte adhesion def. type 1?
Binding (decreased CD18 integrin on WBCs, binds CAM’s)
What structure on both WBC’s and stroma is needed for diapedesis?
PECAM-1 on both
What binds during rolling phase (after margination), and where does each come from?
Vasculature/stroma:
E-selectin from TNFa and IL-1
P-selectin from weibel-Palade bodies
WBCs: Sialyl-Lewis^x
What binds during the adhesion/tight binding phase?
Vasculature/stroma:
ICAM-1
VCAM-1
WBCs:
Integrins (LFA-1, Mac-1, VLA-4)
What binds during the diapedesis phase?
PECAM-1 (CD31) in both WBCs and stroma
Actions of PDGF?
(secreted via activated platelets, macrophages)
- Vascular remodeling
- Smooth muscle cell migration
- FIbroblast growth -> collagen synthesis
Actions of TGF-beta?
- Angiogenesis (like VEGF, FGF)
- Fibrosis
- Cell cycle arrest
What collagen type is first laid down in wound healing (proliferative phase, day 3 - 1 week)? What does it change to during the remodeling phase (1 week to 6+ months)?
Type III to type I
Why should you always test for latent TB before starting anti-TNF therapy?
TNF-a from macrophages maintain granulomas.
If lost, bacteria may disseminate to the blood.