1_2 Flashcards
*3 most commonly described selectins necessary for WBC extravasation during acute inflammation
*E (endothelial)P (platelet)L (leukocyte)WBC extravasation includes1. Margination (selectins)2. Adherence (integrins)3. Diapedesis (interendothelial)
*define diapedesis
*Diapedesis = process of WBC migration inbtwn endothelial cells at the site of injury during acute inflammationInvolves both adhesive and proteolytic events
*Proinflammatory cytokines
*IL-1, 6TNF alpha (cachectin)PGPDGFTGF Chemokinesleukotriene (LTB4)FIRST SOURCE= resident/sentinel tissue macrophages
*2 vasoactive substances involved in acute inflammation
*Histamine—short half life, main source from mast cells, work @ H1 receptorsSerotonin–spp dependentF(x): vasodilation, increase vascular permeability
*Define cytokines
*Diverse group of small soluble proteins that act as IC messengers during physiologic processes. Can work autocrine, endocrine, paracrine. Redundant, pleiotropism
*Anti inflammatory cytokines
*IL-10Lipoxins–inhibit neutrophils/chemotaxisSource=cd4+ TH cells, monocytes, B cellsf(x): decr pro inflammatory cytokines, decrease Ag presentationexcess IL-10 can increase susceptibility to microbial infection
*Physiologic action of PGE2
*Source= many cellsF(x): hyperalgesia, pyrogenic, vasodilation
*Physiologic action of PGF2
*Source= endometrial cells F(x): uterine contraction, bronchoconstriction, vasodilation
*Physiologic action of TxA2 (thromboxane)
*Source : Platelets, macrophagesF(x): Platelet aggregation, Vasoconstriction
*Hallmarks of an acute phase reaction
*FeverLeukocytosisChange in serum acute phase protein concentration
Nitric oxide
source:endothelial (primary), neuronal, inducibleF(x): Vasodilator(potent), Decreases platelet aggregation, Decreases white blood cell adhesion (eNO), free rad production to kill microbes (iNO)both inflm and antiinflam
C reactive protein
Positive acute phase proteinF(x): Activates complement, decreases PMN, increases macrophages, promotes DIC
Complement pathway
ROLE IN OPSONIZATION, PHAGOCYTOSIS, CHEMOTAXIS, CELL LYSIS1. Alternative path (Bacteria)——–>2. Classical path (Ab)——–> Cleave C33. Lectin path (Mannose) ——–>C3a—> anaphlatoxinC3b—> phagocytosisC3b + C3convertase—> C5b+ C6789 MAC—> lysis of bacteria
reperfusion injury pathophysiology
Prolonged ischemia –> incr hypoxanthineWhen reperfused, add oxygenAllows xanthine oxidase to fx to convert hypoxanthine –> xanthine + h2o2H2o2 destabilizes into free radicles–> oxidize cell membranes–> cell death
How are reactive oxygen species counteracted?
- Antioxidant enzymes (Superoxide dismutase, catalase glutathione peroxidase)2. Antioxidant scavenger molecules (Vitamin A, C, E)
Difference btwn Cox1 and cox 2
Both are enzymes in AA pathCOX1 constitutively expressedCOX2 induced by trauma, growth factors, inflm
Arachidonic acid pathway
Cell membrane phospholipids–>AA via phospholipase A2AA –> cyclooxygenase path–> PGI2(prostacyclin inhibits platelets), TXA2(thromboxane promotes platelets), PGE2/PGD2 (vasodilation, permeability, pyrogenic)AA–>lipoxygenase path–>lipoxins(inhibit PMN,antiinflm), leukotrienes LTB4(proinflm)
Source and MOA on TNF ALPHA
Pro inflm cytokineSource: macrophagesMOA: anti tumor activityRelease inflm mediators and cytokinesIncrease CD8+ cytotoxic T cell immunity and NK cells
Source and MOA IL 6
Pro inflm cytokineSource: macrophages, epithelial cells, enterocytes, T cellsMOA: incr liver acute phase proteinsIncrease lymphocyte proliferation
Purine and pyrimidine bases in DNA
Purine: adenine, guaninePyrimidine: cytosine, thiamineA–TG—C
Source and MOA IL 6
Pro inflm cytokineSource: macrophages, epithelial cells, enterocytes, T cellsMOA: incr liver acute phase proteinsIncrease lymphocyte proliferation INCREASES WITH DURATION/SEVERITY OF DISEASE (biomarker)
Difference btwn DNA & RNA
RNA: uracil, ribose sugar, single strandDNA: thiamine, deoxyribose sugar, double strand
Central dogma of molecular biology
Crick 1958Replication(make DNA copy)Transcription(make mRNA)–takes place in nucleusTranslation(make protein)–takes place in ribosome
What transcription factor is critical to cartilage formation
SOX9Can be used to restore changes in ECM of osteoarthritic cartilage