FDN - Exam 3 Flashcards
What does C4BP do?
C4BP binds to C4b prior to C4b covalently binding to a surface
This inhibts binding and ultimately C3 convertase creation
What causes redness and heat?
Arteriolar dilatation
What enzyme acts on arachidonic acid to make leukotriene A4 (LTA4)?
5-lipoxygenase
What fragment in the complement system accomplishes opsonization?
C3b
What type of necrosis is in this picture?
Caseous (note the granuloma)
Formula for O2 delivery to tissues?
Cardiac output (SV * HR) x O2 content of blood (Hb * Hb sat * 1.34)
Hb sat = [Oxy-Hb]/[Total-Hb] x 100
What is the histological hallmark of cell death?
Disappearance of the nucleus
What is reversible cell injury?
Cell survives due to stress response or adaptation
What receptors on macrophages recognize DAMPs?
Toll-like receptors (TLRs), chemokine receptors, integrins, inflammasome (and various others)
What macrophage cytokine attracts neutrophils to sites of inflammation?
CXCL8
Why opsonization?
For improved recognition of pathogens by phagocytes
What is salicylism?
Dose-dependent phenomena that can cause headache, sweating, tinnitus, and dizziness
Severe forms can cause CNS disturbances, acidbase disturbances, fever, and skin erruptions
What causes leukocytosis in acute inflammation?
Demargination via cortisol and epinephrine (you want to get those WBCs away from endothelium, in the blood stream and to the spot of inflammation)
Stimulation of WBC production via cytokines & CSF (macrophage colony stimulating factors… not CSFluid ;)
“left shift” = release of immature WBCs from the bone marrow via endotoxin stimulation or epinepherine & cortisol
Common findings in SIRS?
hyper or hypothermia
tachycardia
tachypenia or reduced pCO2
leukocytosis or leukopenia (worse option!)
neutrophilia and/or “bandemia”
Possible stimuli for a granuloma?
infection (viral, bacterial, fungal, parasitic), autoimmune disease, cancer, foreign material, unknown (like in sarcoidosis)
Just know that a lot of stuff can cause granulomas!
What are the actions of leukotrienes?
Increased vascular permeability, vasoconstriction, bronchospasm
Acetaminophen is generally well-tolerated for what two reasons?
- It does not cause GI distress
- It does NOT effect platelet function
What activates initiator caspases?
Proteolytic cleavage by pro-apoptotic factors
Do all granulomas involve the adaptive immune system?
No
Does fludrocortisone have glucocorticoid effects, mineralcorticoid effects, or both?
Both.
Low enough doses are given to maintain salt-retaining activity without having anti-inflammatory or antigrowth effects
What is thrombodulin?
A protein expressed on the surface of endothelial cells that serves as a cofactor for thrombin. It reduces blood coagulation by converting thrombin to an anticoagulant enzyme
What are myelin figures?
They are derived from organelle and plasma membranes and represent intracellular whorls of laminated lipid material. Do NOT contain actual myelin.
Most likely represent lipoprotein remnants after cleavage by phospholipases.
What are the effects of Thromboxane A2 (TXA2)
Vasoconstriction, platelet activation (pro-coagulant), and decreased blood loss
What is a lipopolysaccharide (LPS)? What kind of negative effect can it have?
A compound or complex of lipid and carbohydrate
Endotoxin is an LPS released from the cell walls of gram negative bacteria that produces septic shock
What is the inflammasome?
A cytoplasmic multiprotein complex that senses cytoplasmic PAMPs and DAMPs
What agents cause granulomas?
Phagocytized but not eliminated (like inert TB) or viruses present in the cytoplasm
These result in persistent stimulation of the adaptive immune system & epithelioid cells
What percentage of genes are regulated by glucocorticoids?
10-20%
How can inflammation be modified pharmacologically?
Via vasoconstrictors, anti-histamines, receptor blockers, etc
Is diapedesis characterized by strong or weak endothelial-leukocyte interactions? What molecules particpate in binding in this stage?
Strong endothelial-leukocyte interactions
PCAM (CD31) on the endothelium and PECAM on the leukocytes are involved
Both PECAMs are inducd by endotheial and WBC activation
What ROS are generated by macrophages?
superoxide anion -> hydrogen peroxide -> hydroxyl radical + nitric oxide (NO)
What is responsible for the conversion of fibrinogen to firbin?
Thrombin (IIa)
What does the CR3 receptor on phagocytes recognize?
Bacterial CH2O
More info via Google: Complement receptor 3 (CR3)(CD11b/CD18) is a human cell surface receptor found on polymorphonuclear leukocytes (mostly neutrophils), NK cells, and mononuclear phagocytes like macrophages. CR3 is a pattern recognition receptor, capable of recognizing and binding to many molecules found on the surfaces of invading bacteria. CR3 also recognizes iC3b when bound to the surface of foreign cells. Binding to the receptor causes phagocytosis and destruction of the foreign cell.
What disease state is shown here?
ARDS
What does fibrinoid necrosis look like at the macroscopic level?
Nothing. We can only see it at the microscopic level
How and where is nitric oxide (NO) generated?
It’s generated in the cell cytoplasm via iNOS (inducible NO synthase)
Toxicity due to withdrawal of steroid therapy can be caused by what two things?
- Potential flare-up of the underlying disease
- Adrenal glands may have atrophied & it will take weeks to months for HPA axis to return to normal
Do NSAIDs reduce the body temperature in all situations?
No, only when the temperature is elevated
What percentage of O2 from aerobic respiration forms ROS?
1-5% (majority becomes water!)
What is plasma cortisol bound to?
90% bound to Corticosteroid Binding Globulin (CBG), remaining 10% bound to albumin
What are some examples of positive acute phase reactants?
Immune-related (complements, MBL), anti-proteases like alpha-1-antitrypsin & alpha-2-macroglobulin, redox participant ceruloplasmin (+ Fe transport)
What is serous inflammation?
Predominance of fluid (inflammatory edema)
Fluid can come from blood stream (i.e. transudate) or from mesothelial cells lining a cavity
What is systemic inflammatory response syndrome (SIRS)?
Detrimental systemic response to acute inflammation
Mediated by higher circulating concentrations of TNF-alpha (most important), IL-1beta, PAF, etc
What type of acute inflammation is shown here?
Fibrinoid
What are the different types of emboli?
Thromboembolism: embolization from a thrombus (VTE: venous thromboembolism)
Septic embolism: mass of bacteria or fungi (endcarditis)
Fat embolism: following trauma to a bone
Cholesterol: following plaque rupture
Air embolism: nitrogen bubble (rapid assent in diving)
Foreign body: catheter, bullet
Name a COX-2 selective inhibitor. What does it treat?
Celecoxib (brand name: Celebrex)
8-10 fold selective for COX-2, lacks COX-1 side effects
Approved for RA, osteoarthritis, and acute pain
How is acute inflammation resolved?
- Removal of the inciting stimulus via control/elimination of infection or removal of necrotic cells
- Repair of injury via fibroblasts, endothelial cells, epithelium, etc
Where does most ROS come from in the cell?
Oxidative phosphorylation in the mitochondria Some from peroxisomes
In the classical pathway, what makes up the C3 convertase?
C4b2a
What is different about a neutrophil moving toward a chemoattractant?
The leading edge (lamellipodium) lacks organelles
There are a higher number of receptors at the leading edge (these receptors bind to substances that stimulate chemotaxis)
Note that the “tail end” of the moving neutrophil is called the uropodium (just think of what area a urologist works in)
What four molecules trigger P-selectin release from Weibel-Palade bodies? Also include what secretes the molecule.
- Histamine - mast cells
- Thrombin - clotting cascade
- PAF - various cells including endothelium and macrophages
- TNF-alpha - macrophages
Once activated, what odes executioner caspase do?
It degrades the caspase-activated DNase (CAD) inhibitor, iCAD, thus activating CAD. Nuclear DNA is cleaved in 200bp fragments
How do platelets aggregate?
A conformational change in GPIIb/IIIa allows it to bind fibrinogen (GPIIb/IIIa can also bind VWF)
Platelets also released thromboxane A2 (a pro-clot forming prostagandin derivative)
Neutrophils are numerically elevated most often in response to what type of infection?
Bacterial
Are leukotrienes arteriole vasodilators?
Nope
What is karyolysis?
DNA degradation by endonucleases; lysis of nucleus Observed in necrosis ONLY (no apoptosis)
What happens in the three stages of blood clotting? Which two stages occur at the same time?
Primary hemostasis: platelet “plug”
Secondary hemostasis: fibrin formed
Tertiary hemostasis: Fibrin cross-linked
Primary & secondary occur at the same time
What leukotriene product is found in mast cells, macrophages, and basophils?
Leukotrienes C4, D4, and E4
Exposed subendothelium presents what factor that can bind to a certain factor in the blood, intiating secondary hemostasis/blood clotting?
Tissue Factor (TF) from subendothelium binds to Factor VII in the blood
Active form: TF/VIIa
What complement regulators are located in the plasma?
C1INH, C4BP, Factor H, and Factor I
What are the adverse manifestations of SIRS?
Exaggerated or aberrant APR findings (ex: decreased WBC count; very high or very low temp)
Shock
Disseminated intravascular coagulation (DIC)
multi organ failure
If the source of a thromboemboli is an arterial thrombus, what is a possible consequence?
Stroke
What is responsible for the systemic effects of acute inflammation?
Cytokines!!
Endogenous DAMPs, exogenous PAMPs
What is gangrenous necrosis?
Subtype of coagulative necrosis caused by ischemic necrosis of an extremity (with or without concurrent infection), ischemic necrosis of the bowel, or tissue necrosis due to significant infection
How do exudates form?
Via inflammation, direct injury (trauma, infection) or via crush injury (rhabdomylosis)
What causes smooth muscle relaxation of ultimately hyperemia?
NO (nitric oxide) secreted from endothelial cells
What is the normal cellular response to chronic irritation (physical or chemical)?
Metaplasia
What three things can cause an infarction?
- Thrombus
- Embolus
- Mechanical factors (vessel compression, mechanical obstruction)
Are prostaglandins primary mediators of vascular permeability?
NO. They potentiate the actions of other agents
What does LTB4 do?
Attract more leukocytes (aka leukocyte chemotaxis)
If ACTH is lost, will we still have aldosterone production?
Yes, it only decreases by about 50%
What chemical mediators are responsible for arteriolar dilatation? Include the major source as well.
Histamine -mast cells
Serotonin - platelets
Bradykinin - plasma
PAF - various cells, platelets, endothelial
What is Budd-Chiari syndrome?
Hepatic vein thrombosis. Liver swells, increased portal vein pressure
Why is opsonization important?
Necessary for control of infections due to encapsulated bacteria
These capsules impair phagocytosis but opsonized pathogens are more readily phagocytized
What does Factor H do?
It inhibits Factor B binding to C3b in the alternative pathway & stimulates Factor I to degrade C3b
iC3b becomes C3c and C3dg
This is beneficial if/when C3b accidentally binds to self. Factor H determines if C3b goes down the alternative pathway or the degradation pathway
What type of nuclear change is observed here?
Pyknosis
Do we see organelles in blebs in necrosis or apoptosis?
Apoptosis
What type of acute inflammation is shown here?
Serous inflammation
What are examples of clinically significant biomarkers of cell injury?
Troponin from cardiac muscle, transaminase from hepatocytes, and alkaline phosphatase from bile duct epithelial cells
What type of macrophage provides positive evidence of chronic pulmonary congestion?
Hemosiderin-positive macrophages aka “heart failure” cells
How are damaged lipids repaired?
They’re not. They’re degraded by phospholipases (harmful degradation products!)
What causes swelling in typical cases of inflammation?
Venular permeability
How is the classical pathway initiated?
By the production of a C1 Esterase
C1q can bind directly to a pathogen, CRP molecule, or to an antibody. Once bound, C1r aquires enzymatic activity and cleaves C1s to generate a serine protease. C1s then acts on C4 and C2.
Is attachment characterized by strong or weak endothelial-leukocyte interaction? What molecules are involved in binding?
Strong endothelial-leukocyte interaction
Integrins (LFA-1, Mac-1, and VLA-4) on the leukocyte bind to immunoglobulin super(gene) family (ICAM-1 and VCAM-1) on endothelial cells
Can glucocorticoids bind to mineralcorticoid receptors?
Yes.
An enzyme that converts cortiol to cortisone in some tissues stops this effect (cortisone has minimal affinity for aldosterone receptors)
Hyposecretion of the adrenal gland is what?
Hypersecretion of the adrenal gland is what?
Hypo = Addison’s
Hyper = Cushing’s
What complement fragment is responsible for opsonization?
C3b
(the first goal of the C’ cascade is to opsonize target pathogens!)
What acivates I -> Ia pathway?
IIa
What is a corticosteroid? Name the two types.
A hormone produced by the adrenal cortex
Glucocorticoids and mineralcorticoids
How do macrophages trigger inflammation?
Cytokine secretion
Patients taking ______ should not take Aspirin due to bleeding risks.
Warfarin
Unsuccessful repair of inflammation can lead to what?
Abscess, chronic inflammation, and granulomas
What are the three main sources of cellular stress?
Exogenous - physical, exogenous - biological, endogenous
How would you classify Ibuprofen and Naproxen (Aleve)?
Non-selective/non-salicylate drugs
More potent but NOT more efficacious than Aspirin
What is the normal cellular response to decreased nutrients and decreased stimulation?
Atrophy
Inhibiting COX may divert to the lipoxygenase pathway and increase production of leukotrienes. In what disease is this relevant?
Asthma
What is acute respiratory distress syndrome (ARDS)?
A clinical syndrome of severe dyspnea (shortness of breath) of rapid onset, hypoxemia, and diffuse pulmonary infiltrates leading to respiratory failure
What is chemotaxis?
Locomotion along a concentration gradient
How can acute phase proteins be classified? What is the reasoning behind this classification?
Positive and negative
Positive reactants are increased during acute phase inflammation, but this comes at the cost of the production of other proteins (negative reactants)
Can phagocytes recognize the sterile products of injured or necrotic cells to initiate inflammation?
Yes!
They have receptors that recognized DAMPs (damage/danger associate molecular patterns)
What are free radicals?
Molecules containing unpaired electrons They form covalent bonds with other molecules and impair or block function; chain reaction of covalent bonds amplifies molecular damage Arise from endogenous and exogenous sources
What attracts NSAIDs to areas of inflammation?
low pH of inflammatory environment
What is a scab?
A crust formed by the coagulation of blood (fibrin), pus (neutrophils), serum, or a combo
Forms on the surface of ulcers, erosions, or other types of wounds
What reaction creates the hydroxyl radical in macrophages? What element is required for this reaction?
The Fenton rxn
Iron (Fe) is required!
What WBC is VLA-4 (an integrin) present on?
monocytes
What comprises exudate?
Plasma (C’ and Ig) and cells (neutrophils and macrophages)
What are the two pathways that trigger apoptosis? What enzyme do those pathways converge on?
Extrinsic and Intrinsic Caspases
What is the first change in most cell injury? Is this reversible or irreversible?
Cloudy swelling Reversible
What does ionizing radiation do to DNA?
It fragments it/causes double strand breaks
What are some possible results of toxicity due to continued use of supraphysiological doses?
Hyperglycemia, psychosis, osteoporosis, ulcers, edema, hypertension, impaired wound healing, etc
What prostaglandin is indirectly responsible for pain?
PGE2
What are the effects of PGE2, PGF2alpha, PGD2?
Vasodilatation, increased vascular permeability, but NO platelet effects
What is paroxysmal nocturnal hemoglobinuria? What causes this?
A deficiency in GPI (membrane anchors) stops CD55 and CD59 from being attached to cell surfaces. The regulation of the complement system is now irregular (primarily lack of CD59 causes pores to be made in RBCs [CD59 normally inhibits C9 in polymerizing and making the pore!] - Hb leaks out and collects in urine overnight. These people have VERY dark urine in the morning)
What type of necrosis is seen here?
Fibrinoid
Eosinophils typically increase in concentration in the blood in response to what type of infection and what type of immunologic condition?
Parasitic infection and allergy
What are the two categories of glucocorticoid toxicity?
- Toxicity due to withdrawal of steroid therapy
- Toxicity due to continued use of supraphysiological doses
What is metaplasia? Provide an example.
Change in phenotype of differentiated cells, often in response to chronic irritation May result in reduced function or increased propensity for malignant transformation Chronic exposure to cigarette smoke leads to this in the bronchus (pseudostratified to stratified squamous)
What are the signals from injured or necrotic cells that trigger inflammation when perceived by macrophages?
DAMPs - Danger (or damage)-associated molecular patterns
What is autophagy?
Formation of double membrane autophagosome around damaged or unnecessary cell components followed by fusion with lysosome, degradation, and recycling of building blocks to cytosol for new synthesis
What are giant cells?
Arise from macrophage fusion
Nuclear division but not cytokinesis
Do NOT require T cells but can be induced by them
What are the phagocyte receptors for IgG bound to a pathogen and C3b bound to a pathogen?
IgG (bound to pathogen) - FcyR (on phagocyte)
C3b (bound to pathogen) - CR (on phagocyte)
What inhibits Aspirin/what should a patient taking Aspirin not take concurrently?
Ibuprofen
Note: ibuprofen binds reversibly
What are the typical manifestations of APR?
Fever (1-4*C increase)
Acute-phase proteins are altered
Leukocytosis (Increased WBC count)
What triggers platelets to release serotonin, histamine, and produce PAF?
Platelet adhesion followed by platelet aggregation
What cells are involved in healing?
Macrophages, platelets, fibroblasts, endothelial cells, epithelial cells
What molecule is the precursor for leukotrienes and prostaglandins?
Arachidonic acid
What three things does cortisol inhibit?
- CRH
- ACTH
- Inflammatory cytokines (IL-1, IL-2, IL-6, and TNFa)
What are myelin figures?
Dark whorls and aggregates that look like myelin inside cells but are not Caused by damaged and abnormal membranes
What is the mechanism of action of glucocorticoids?
They dimerize with a receptor in the cell cytoplasm and then either act as transcription factors in the nucleus or stimulate other TFs to act
What cardiovascular concerns are there in regards to NSAIDs?
They increase blood pressure (due to sodium retention in the renal tubules & via interactions with catecholamines & angiotensin II)
Do all forms of swelling result from exudates?
Nope. Transudates can cause swelling too
The synthesis of what requires free radicals?
Prostaglandins
What leukotriene product is found in neutrophils and macrophages?
Leukotriene B4 (LTB4)
What fragment in the complement system recruits inflammatory cells?
C5a
What are the clinical findings in a pulmonary embolus?
Shortness of breath, chest pain, tachypnea, and hemoptysis (with infarction)
What protein is a key trigger for apoptosis (hint: from the mitochondria)?
Cytochrome C
Blood clotting involves the interaction of what three “systems” (more like things)?
Blood vessel wall (endothelium), platelets, and plasma protein clotting factors (like VIII)
What are the roles of platelets in acute inflammation?
Hemostasis, wound repair, and secretion of products to cause acute vascular changes (like platelet-derived growth factor) They also release serotonin, histamine, and platelet-activating factor (PAF) to cause vascular effects (dilatation and increased permeability)
What are these cells?
Atypical lymphocytes
We can tell bc they’re larger than normal, have more cytoplasm, and have nucleoli in their nucleus
What type of WBC is elevated most often in response to viral infection?
lymphocyte
Irreversible cell injury can end with either _______ or _________
necrosis (cell lysis) or apoptosis
What is suppurative (or purulent) inflammation?
Pus! Neutrophils (alive or dead), cellular debris, and possibly dead tissue
Usually caused by microbial pathogens
What are the major effects of ATP depletion?
- Impaired Na+/K+ (causes influx of Ca2+, efflux of K+, ER swelling, cellular swelling, loss of microvilli and blebs) 2. Increased anaerobic glycolysis -> lactic acid formation -> decreased pH -> nuclear chromatin clumping 3. Inhibition of protein synthesis -> impaired response to stress and adaptation
What activates X -> Xa pathway?
IXa + VIII
What are the two basic components of acute inflammation?
vascular changes and cellular changes
What are reactive oxygen species (ROS)?
Chemically reactive and unstable forms of oxygen Most ROS are formed as toxic byproducts of cellular metabolism; but have roles in normal biosynthesis ROS are inactivated by many cellular detoxification pathways (ex: SOD)
How does cytochrome C get out of the mitochondria in the intrinsic pathway?
Bcl2 family creates a permeability pore on the outside of the mitochondria
What is the normal cellular response to cumulative sublethal injury over a long life span?
Cellular aging
What is acute inflammation?
A protective reaction of vascularized tissue to injury. Part of the innate immune system
How can thrombi be classified?
- Arterial - platelet rich, white in apperance
- Venous - fewer platelets, many RBCs, red in appearance
What three mechanisms cause chronic inflammation?
- Failure to resolve acute inflammation
- Repeated episodes of acute inflammation (i.e. persistent stimulus)
- de novo (without apparent acute inflammation)
What part of granuloma formation can cause disease?
Fibrosis
What characterizes an abscess?
A type of purulent inflammation
Produces a caivty due to liquefaction necrosis
When do we see myelin figures? Reversible or irreversible cell injury?
Both! Although they are more prominent in irreversible injury
Does apoptosis have ATP depletion?
No
In what instance is apoptosis pathologic?
In some forms of cell injury like DNA damage that triggers apoptosis
What does glutathione peroxidase (GPX) do?
In its reduced form (GSH) it reacts with ROS (H2O2 or *OH) to yield water and the oxidized form (GSSG)
What is it called when alveoli collapse?
Atelectasis
(Note: with atelectasis the lung can be described as “collapsed”)
Define cell injury
Sequence of events following exposure to stress or source of damage (i.e. nutrient deprivation) that affects essential cell components and their functions in a manner that exceeds the limits of the cell’s adaptive responses
Why is bacterial lysis important?
Because for some bacteria opsonization isn’t enough to control the infection (ex: Neisseria bacterias)
What are the consequences of a venous thrombosis?
Venous obstruction which will lead to downstream blockage of venous return
Extension of the thrombus, embolization (most commonly to lung), and infarction (uncommon)
Results in peripheral edema, leg pain, and warmth
What enzyme creates hydrogen peroxide from superoxide anion?
superoxide dismutase (SOD)
What complement regulators are located on the cell surface?
CD59 and CD55
What is an embolus?
A plug composed of detached thrombus, mass of bacteria, or foreign body that is occluding a vessel
What are examples of endogenous cellular stresses?
Cellular metabolism, inflammation, mutagenesis, immunological anomalies
What does Prostaglandin H-2 (PGH-2) become in mast cells?
PGD2
What is the normal sequence of events in inflammation?
- Cellular injury (necrosis, infection, hemorrhage, etc)
- Vascular changes (hyperemia & increased vascular permeability)
- Leukocyte emigration & leukocyte actions
- Healing with return to normal structure or scar
What cells produce leukotrienes?
Neutrophils, mast cells, macrophages, and various other cells
Where do we see E-selections? Is their expression constituitive, pre-formed, or synthesized on the spot?
on the Endothelium
They are synthesized as needed/as triggered by inflammation
What other vaso-active factors can contribute to shock?
histamine, bradykinin, and serotonin
What are the five major targets of cellular injury?
Plasma membrane
Mitochondria
Ribosomes
Cytoskeleton
Nucleus
What are the six steps of phagocytosis?
What does TGF-beta do in healing?
Stimulates collagen secretion by fibroblasts
(Note: autocrine signaling - fibroblasts secrete TGF-beta to create a positive feedback loop and stimulate themselves)
Does rolling contain weak or strong endothelial-leukocyte interactions? What is the interaction/binding between the two cell types?
Weak interaction
Selectin-selectin binding
Sialyl-Lewisx on leukocytes and P-selectin & E-selectins on endothelium
What is fibrinous inflammation?
Exudation of plasma proteins with fibrin deposition
Typically occurs over a surface like the pericardium, pleura, or peritoneum
What is opsonization?
The process of recognizing pathogens by coating them with C’ components, antibodis, or other opsonins (like CRP)
What are the four actions of complements?
- Opsonization
- Recruit inflammatory cells to sites of infection/inflammation
- Pathogen lysis
- Clearance of immune complexes
** for all of these activities C’ must bind to non-self
What are the consequences of a thromboembolism to the pulmonary artery?
V/Q disturbance (ventilation and perfusion disturbance)
Platelets release serotonin, aterio-venous fistula open, acute hypoxia (+/- death)
What is a purulent exudate?
Exudate rich in neutrophils (PUS); often results from bacterial infection
What fragment in the complement system clears immune complexes?
C3b
If the source of a thromboemboli is a venous thrombus, what is a possible consequence?
Pulmonary embolus to the pulmonary artery
What is the source(s) or HOCl?
Neutrophils and monocytes
NOT macrophages