General Path. Flashcards
antigen surveillance
T cells use TCR complex
CD4 - MHC II
CD8 - MHC I
signals for cd4 activation
> antigen presented with MHCclass ii > B7 on APC binds CD28 on CD4Tcell
cd4 can help two cells
B cells, CD8
th1 subset secretes ____ during NFL;
what is the effect?
IFN gamma; > activates macrophage > promotes formation of Th1 > inhibits formation of Th2 IL2; > Tcell GF > CD8 activator
th2 subset secretes ____ during NFL;
what is the effect?
> IL4; class switch from igG to E > IL5; eosinophil chemotaxis/activation, Bcells => plasma & class switching to IgA > IL10; inhibits Th1 phenotype
cd8 cytotoxic is activated with
> Ag presented on MHC I
> IL2 from cd4
what do cytotoxic t cells secrete?
perforins
granzyme
Fas ligand
B lymphocytes activated by
> Ag presented on MHC class II > CD40 on B cell to CD40L on helper T cell
epitheliod histiocyte
> macrophage with abundant pink cytoplasm
UZE surrounded by giant cells and rim of lymphocytes
this is the defining feature of a granuloma
non caseating granulomas
> lack central necrosis
> from rxn to foreign material
caseating granulomas
> exhibit central necrosis
> characteristic in TB and fungal infections
differential for non caseating granulomas
> Chron’s
sarcoidosis
beryllium
cat scratch disease
what macrophage cytokine stimulates formation of Th1 helper T cells
IL-12; this happens in both caseating and non caseating granulomas
what Th1 cytokine stimulates formation of epitheliod histiocytes and giant cells?
IFN gamma
what are the key mediators in apoptosis
caspases
leukocyte MARGINATION
> step 1
vasodilation slows blood in POST CAP. VENULES
cells marginate from center to the PERIPHERY
leukocyte ROLLING
> step 2
histamine triggers Pselectin from WEIBEL PALADE bodies
Eselectin induced by TNF & IL1
selectins on endothelial
leukocyte ADHESION
> step 3
ICAM/VCAM on endothelium (TNF, IL1 trigger)
Integrins on leukocytes (C5a, LTB4 triggered)
interaction btn CAMs and integrins is FIRM
leukocute TRANSMIGRATION, CHEMOTAXIS
> step 4 > neutrophils attracted via >>> bacterial products >>> IL8 >>> C5a >>> LTB4
leukocyte PHAGOCYTOSIS
> step 5
enhanced by opsonins.
» IgG
» C5b
leukocyte WASTE REMOVAL
> step 6
O2 is the most effective mechanism
HOCl is generated during oxidative burst and kills microbes
oxidative burst enzymes
O2 => O2- => H2O2 => HOCl
1) NADPH oxidase
2) superoxide dismutase
3) myeloperoxidase
What does elevated D-dimer mean? why?
> abnormal thrombotic states (DIC, DVT, pulm. embol.)
D-mers are are a type of FIBRIN SPLIT PRODUCT
fibrin split products occur from degrading fibrin clots
Virchows triad
> hypercoaguloability
abmornal blood flow
endothelial injury
clinical conditions of hypercoagulobility
factor V leiden and prothrombin gene mutations
many others too, but these are common inherited
clinical conditions of abmornal blood flow
> turbulence from athrerosclerotic plaques
stasis from sickle cell anemia vascular occlusions
hyperviscosity from polycythemia vera
clinical conditions of endothelial injury
> vasculitis
trauma, inflammation
hypertension
warfarin inhibits
> inhibits all of the calcium dependant clotting factors
> 2, 7, 9, 10, protein C, protein S
heparin acts on
> anti-thrombin III to accentuate/catalyze inhibition of factor 10a and 9 a.
both heparin and warfarin act on both sides of the coagulation cascade (T/F) Significance in labs?
true. they both increase PT/INR and PTT
which test is most sensitive for coumadin?
coumadin is most sensitive to PT/INR testing
which test is most sensitive for heparin?
heparinis most sensitive to PTT testing
relationship between warfarin and coumadin
they are the same. “Coumadin” is the brand name for the active ingrediant warfarin sulfate
streptokinase is?
> bacterial enzyme
> it cleaves plasminogen to plasmin => FIBRINOLYSIS of fibrinclot
lymphadenitis vs lymphangitis
clinical features
> angitis appears as a red, subQ streak
> adenitis is enlargement of the nodes
