Acute Inflammation

Description:	USCSOM: Pathology: Acute Inflammation
Category:	Bacteriology
Created by:	null on 2009-08-23

Question	Answer
What are the six cardinal signs of inflammation?	Heat, redness, swelling, pain, loss of fxn, systemic changes
What are the three time categories of inflammation?	Acute (0-48hrs), Subacute (2-10days), Chronic>2weeks
What inflammatory cells are involved in acute inflammation?	heutrophils
WHat inflammatory cells are involved in chronic inflammation?	monocytes, lymphocytes, plasma cells, macrophages, granuloma cells
What is the first hemodynamic change that takes place in acute inflammation?	vasoconstriction followed by vasodilation
Where does increased permeability take place in the vasculature?	postcapillary venules
What is exudation?	leakage of fluid and cells into interstiital space
What are the stages of leukocyte exudation?	Margination, adhesion, emigration, chemotaxis
Describe the selectin family.	Ca-dependent lectins; expressed on the surface of endothelium; mediate rolling of leukocytes at site of inflammation
What is P-selectin?	stored in weibel-Palade bodies and alpha-platelet granules; stimulated of TNF or IL-1
What is E-selectin?	synthesized de novo; later recruitment of leukocytes; stimuled by TNF or IL-1
What is L-selectin?	Lymphocyte binding to lymph node venules
What is ICAM-1?	intercellular adhesion molecule; surface of cytokine stimulated endothelium
What is VCAM-1?	vascular cell adhesion molecule; receptor for lymphocytes, monocytes, eosinophils, basophils
What is PECAM-1?	platelet endothelial cell adhesion molecule; CD-31; important in diapedesis
What are integrins?	adhesion molecules; transmembrane in structure; heterodimers
What is the most notable Beta-1 integrin?	VLA-4; expressed on leukocytes; bind to VCAM-1
What are beta-2 integrins?	localization of phagocytes to injury; LFA-1 and Mac-1, and CR3/4 are examples
What are the 3 pathways for killing/degradation via phagocytosis?	oxygen-dependent (h2o2); h202-myeloperoxidase-halide system; oxygen-independent (leukocyte granules)
What are the effects of histamine and serotonin?	arteriorlar dilation; constriction of large arteries; increased permeability of postcapillary venules; immediate and transient
What types of cells store histamine and serotonin?	mast cells, basophils, platelets
What is the critical step in activation of complement?	cleavage of C3
What are the 3 pathways of complement?	classic (c1), alternate (c3's), lectin (c1-mannose)
Which complement fragments are anaphylatoxins? What is their role?	C3a,C4a,C5a; stimulate histamine release
What complement serves as chemotaxis?	C5a
What complement serves helps to opsonize foreign bodies?	C3b
What is Hageman Factor?	Factor XII of clotting system; triggers kinin and clotting
What is the first step in the kinin system?	prekallikrein to kallikrein by activated Hageman
What does kallikrein do?	forms bradykinin; amplifies Hageman; breaks C5 up; converts plasmin
What does bradykinin do?	short-lived vasoactive peptide; increases vascular permeability; dilates blood vessels; contracts smooth muscle; causes pain
What is the primary peptide in bee stings?	bradykinin
What role does thrombin play?	cleaves fibrinogen into insoluble fibrin clots; link between coagulation system and inflammation
What is plasmin's primary role?	lyses fibrin clots
What role does plasmin play in inflammation?	activated Hageman; cleaves C3; increase vascular permeability
What are the two pathways for arachidonic acid?	Cyclooxygenase and Lipoxygenase
What is Thromboxane A2?	potent platelet aggregator and vasoconstrictor
What is Prostacyclin PGI2?	vasodilator and inhibitor of platelet aggregation
What is PGE2?	sensitizes skin to painful stimuli; cytokine induced fever
What is PGD2, PGE2, PGF2?	causes vasodilation and potentiate edema
What is the lipooxygenase pathway?	converts arachidonic acid to HPETE, to HETE, to leukotrienes
Describe Leukotriene B4.	potent chemotactant, neutrophil aggregation, stimulate ROS and lysosomes
Describe Leukotrien C4,D4,E4.	intense vasoconstriction, bronchospasm, vascular permeability
Describe Lipoxins A4,B4.	negative regulators for leukotrienes, inhibit leukocyte action
How is lipoxin formed?	transcellular biosynthetic mechanism; neutrophillic stimulation of platelets
What are some actions of PAF?	Platelet activating factor; vasoconstriction, bronchoconstriction, leukocyte chemotaxis, PG and LkTr synthesis
What are the two KEY cytokines of inflammation?	Interleukin-1 and Tumor Necrosis Factor
What mainly produces IL-1 and TNF-alpha?	macrophages
What is the role of chemokines?	stimulate leukocyte recruitment in inflammation
Describe CXC or alpha chemokines.	act on neutrophils; IL-8
Describe CC or beta-chemokines.	act on mono, eosinophils, basophils, lymphcytes; MCP-2
Describe C or gamma-chemokines.	act of lymphocytes; lymphotactin
Describe CX,C chemokines.	monocytes and T-cells; fractaline
What types of cells produce NO?	macrophages and endothelium
What are the effects of NO release?	vasodilation; reduce platelet aggregation and inflammatory response; microbicidal actions
What are the effects of extracellular release of ROS?	endothelial cell damage; inactivation of antiproteases; injury to cells
What are some neuropeptides involved in acute inflammation?	substance P and Neurokinin A
What are some biologica fxns of Substance P?	pain signals, regulate BP, stimulate secretions, increase vascular permeability
What are the most likely mediators of vasodilation?	prostaglandins, NO
What are the most likely mediators of vascular permeability?	histamine, C5a, bradykinin, Leukotrienes, PAF, Substance P
What are mediators of Chemotaxis?	C5a, Leukotriene B4, Chemokines
What are mediators of fever?	IL-1, IL-6, TNF, Prostaglandins
What are mediators of pain?	prostaglandins, bradykinin
what are mediators of tissue damage?	lysosomal enzymes, ROS, NO