Leukocyte activation and adhesion to vascular endothelial cells is a critical step in the inflammatory process. This process is regulated by which of the following molecules? a. The selectins b. The b5 integrins c. The immunoglobulin supergene family d. Nitric oxide e. IL-8

1 Answer

Answer :

Answer: a, c, d, e  The temporal events that initiate and propagate neutrophil recruitment and inflammation include endothelial cell activation and expression of endothelial-derived neutrophil adhesion molecules, neutrophil-endothelial cell adherence, and neutrophil transendothelial migration via established neutrophil chemotactic gradients. There are three major families of adhesion molecules which are expressed on the surface of leukocytes and endothelial cells and are important for leukocyte-endothelial cell interactions. These include the immunoglobin supergene family (ICAM-1, VCAM-1, and PECAM-1), the selectins (E-selectin, P-selectin and L-selectin), and the integrins. The leukocyte b2 integrin adhesion molecule family consists of three members with heterodimeric glycoproteins displayed as a variable alpha and a constant beta chain. Nitric oxide regulates the adhesion process both by direct influence on leukocyte binding as well as by regulation of regional blood flow. IL-8 is one of the most potent mediators of chemotaxis in the C-X-C chemokine family. It serves an important role in neutrophil recruitment and activation, and the continued propagation of the inflammatory response

Related questions

Description : Which of the following statements regarding endothelial cells in acute inflammation are true? a. Endothelial cells are characterized by phenotypic homogeneity b. Specific patterns of receptor expression ... blood flow and leukocyte adhesion d. Endothelial cells may be capable of phagocytosis

Last Answer : Answer: b, c, d Endothelial cells are increasingly recognized to be phenotypically heterogeneous. Specific receptor molecules are expressed at various sites where they help to direct lymphocytes and ... rather, they possess the ability to direct and focus many aspects of an inflammatory event

Description : Which of the following statements regarding IL-1 are correct? a. While IL-1 and TNFa share many biologic effects, IL-1 appears to be more potent b. IL-1 expression is in part ... production d. The ability of IL-1 to upregulate endothelial cell-neutrophil adhesion molecules is relatively limited

Last Answer : Answer: b IL-1 and TNFa share many biologic properties. In addition, each potentiates the effects of the other one when given concurrently. Overall, IL-1 alone probably has weaker effects than ... IL-1 provides a key step in the extravasation of leukocytes to sites of local inflammation and injury

Description : Which of the following statement(s) is/are correct concerning the immunoinflammatory response to shock? a. The anaphylactoxins, C3a and C5a, are products of activation of only the classical pathway ... effects d. Platelet-activating factor can be released by both circulating and fixed tissue cells

Last Answer : Answer: d Inflammatory mediators have recently been recognized as playing a significant role in the clinical manifestations and progression of shock and the development ... increased pulmonary vascular resistance, bronchoconstriction, peripheral vasodilatation, and increased vascular permeability

Description : Which of the following statements are true of the multiple organ dysfunction syndrome (MODS)? A. The two-hit model proposes that secondary MODS may be produced when even a relatively ... intensive care units has decreased owing to increased awareness, prevention, and treatment of the syndrome.

Last Answer : Answer: ABC DISCUSSION: MODS is part of a clinical continuum that begins with the systemic inflammatory response syndrome, which is the host's stress response to any major insult such ... pathogenesis of MODS, the incidence of MODS continues to increase without a significant improvement in outcome

Description : Neutrophil chemotaxis is a fundamental aspect of inflammatory injury in conditions such as the Adult Respiratory Distress Syndrome (ARDS). Neutrophil chemotaxis is directly attributable to which of the following molecules? ... TNFa c. LPS d. IL-1 e. ENA-78 (Epithelial Neutrophil Activating Protein)

Last Answer : Answer: a, e There is a large collection of peptide, polypeptide and lipid mediators which have chemotactic properties. Although TNF a, IL-1 and LPS were initially reported to have direct ... are several complement-derived peptides. Perhaps, the most potent of these is the short-lived C5a peptide

Description : Which of the following statement(s) is/are true concerning ischemia reperfusion injury? a. During ischemia, ATP degradation results in increased plasma and intracellular levels of ... immunization with antibodies to neutrophil adhesive complex lessen the ischemic/reperfusion microvascular injury

Last Answer : Answer: a, b, c, d During the ischemia and hypoperfusion phase, degradation of ATP stores essential to maintain cell integrity and significant loss of diffusible ... either the neutrophil adhesive complex or the endothelial selectins dramatically lessens ischemia/reperfusion microvascular injury

Description : Which of the following statement(s) is/are true concerning the pulmonary response to shock? a. The acute pulmonary vascular response to shock differs markedly from that of systemic vasculature b. The ... elements e. A decrease in lung compliance may result from the loss of type I pneumocytes

Last Answer : Answer: c, d, e Contributing pathophysiologic processes to the pulmonary manifestations of shock include the pulmonary component of the cardiovascular response, disruption of the normal ... injury from mediators of inflammation elaborated elsewhere, and from activated cellular blood elements

Description : Which of the following statements regarding cytokines is incorrect? A. Cytokines act directly on target cells and may potentiate the actions of one another. B. Interleukin 1 (IL-1) ... organ dysfunction syndrome because of its multiple actions and the secondary cascades that it stimulates.

Last Answer : Answer: C DISCUSSION: Cytokines are soluble peptide molecules that are synthesized and secreted by a number of cell types in response to injury, inflammation, and infection. Cytokines, which ... is thought to play a central role in the stress response, particularly in response to endotoxemia

Description : Which of the following statements about septic shock are true? A. A circulating myocardial depressant factor may account for the cardiac dysfunction sometimes seen with shock due to sepsis or ... animal studies that demonstrate a significant improvement in survival with the use of such agents.

Last Answer : Answer: AB DISCUSSION: Shock due to sepsis or SIRS frequently manifests as a hyperdynamic cardiovascular response, consisting of an elevated CI and a decreased SVR or SVRI. Occasionally, ... been encouraging thus far in human clinical trials, despite the promising results from many animal studies

Description : Which of the following belong to the family of C-X-C chemokines? a. IL-8 b. IL-10 c. Growth Related Oncogene-a d. Leukotreine B4 e. b Thromboglobulin

Last Answer : Answer: a, c, e A particularly important group of novel chemotactic cytokines has been elucidated over the last decade. Twelve are known and are listed below. C-X-C ... in vivo cytokine networks involving these molecules which regulate chemotaxis, and other fundamental aspects of inflammation

Description : The complement system consists of a series of serum proteins that exist in a quiescent or very low-level state of activation in the uninfected host. Which of the following ... certain complement components serve as chemoattractants to additional cellular components of the host defense mechanism

Last Answer : Answer: a, c, d Complement activation can occur through either classic or alternate (properdin) pathways, both of which eventuate in deposition of terminal complement pathway components on the ... and release of lysosomal enzymes that can directly damage certain target tissues, such as the lung

Description : Platelet activating factor is: a. Generated by the action of phospholipase A2 on membrane phospholipids b. Antiinflammatory in most of its actions c. Synthesized by endothelial and other cells d. Exerts a variety of biologic effects which are platelet-independent

Last Answer : Answer: a, c, d Like the eicosanoids, platelet-activating factor (PAF) is not stored in cells but is rapidly produced during inflammation. PAF exerts a variety of biologic effects ... and LTB4. There is considerable overlap and redundancy in the effects produced by PAF and eicosanoids

Description : Which of the following statement(s) is/are true concerning the proliferative phase of wound healing? a. The macrophage is the predominant cell type b. The pink or purple-red appearance of a wound ... amino acids, hydroxyproline and hydroxylysine d. The predominant collagen type in a scar is type 3

Last Answer : Answer: b, c The proliferative phase of wound healing begins with the formation of a provisional matrix of fibrin and fibronectin as part of the initial clot formation. Initially, the provisional ... The principal collagen type scar is type 1, with lesser amounts of type 3 collagen also present

Description : Which of the following cell types are not crucial for healing a clean, incisional wound? A. Macrophage. B. Platelet. C. Fibroblast. D. Polymorphonuclear leukocyte. E. Myofibroblast.

Last Answer : Answer: DE DISCUSSION: Experimental studies have shown that healing may progress normally in the absence of polymorphonuclear leukocytes in an uninfected wound. In contrast, depletion of monocytes and ... wound contraction in open defects but have little if any role in clean, incisional wounds

Description : The following statement(s) is/are true concerning host defense mechanisms to intraabdominal infection. a. Bacterial clearance can occur via translymphatic absorption b. Phagocytic activity and bacterial killing can ... may be walled off but are seldom sealed by the omentum and other mobile viscera

Last Answer : Answer: a, b, c The introduction of microorganisms into the normally sterile peritoneal environment invoke several potent specialized host antimicrobial defense mechanisms. Bacterial clearance, ... the contaminated enteric contents walled off, preventing continued soilage of the peritoneal cavity

Description : The neurohormonal arm of the stress response is well defined. Less is known about the inflammatory arm mediated primarily by cytokines. Which of the following statement(s) is/are true ... Cytokine release may stimulate the release of other cytokines leading to an important cascade of events

Last Answer : Answer: a, d Cytokines, which are produced at the site of injury by endothelial cells and by diverse immune cells throughout the body, also occupy a pivotal position in the stress response ... act as hormones and spill over into the systemic circulation and become detectable in the bloodstream

Description : Which of the following statement(s) is/are true concerning the antibody response to an invading antigen? a. All antibodies are composed of one type of heavy and one type of light protein chain b. ... stimulus d. Immunoglobulins A, D, and E play an active role in the circulating humoral response

Last Answer : Answer: a Humoral defenses consist of antibody (immunoglobulin; Ig) and complement. All Ig classes (IgM, IgG, IgA, IgE, IgD) and IgG subclasses are composed of one type (M, G, A, E, D ... exist in smaller amounts in the circulation and do not appear to play a major role as host defense components

Description : Which of the following statement(s) is/are true about the role of macrophages in the wound healing process? a. Macrophages are the dominant cell type during the inflammatory phase of wound ... phagocytosis d. Macrophages are a source of a number of humoral factors essential for wound healing

Last Answer : Answer: a, d Within three or four days after injury, macrophages become the dominant cell type in the inflammatory phase of wound healing. The role of macrophages is not limited only ... . These studies confirm the dominant role of the macrophage and the inflammatory phase of wound healing

Description : Under certain circumstances, the gut may become a source of sepsis and serve as the motor of systemic inflammatory response syndrome. Microbial translocation is the process by which microorganisms ... intestinal mucosal permeability c. Decreased host defense mechanisms d. Lack of enteral feeding

Last Answer : Answer: a, b, c, d 99 Translocation is promoted in three general ways: 1) altered permeability of the intestinal mucosa as caused by shock, sepsis, distant injury, or cell toxins; 2) ... trauma patient d. Fifty percent of non-nitrogen caloric requirements should be provided in the form of fat

Description : Which of the following is an adhesion glycoprotein? A. Fibronectin. B. Tenascin. C. Laminin. D. Hyaluronic acid. E. Collagen type IV.

Last Answer : Answer: ABC DISCUSSION: Cell adhesion glycoproteins such as fibronectin, vitronectin, laminin, and tenascin provide a railroad track to facilitate epithelial and mesenchymal cell migration over the wound ... , and collagen type IV is a protein that is a crucial component of basement membrane

Description : Platelets have a wide array of functions in inflammation. Which of the following are among these? a. Synthesis and release of vasoactive eicosanoids b. Release of chemotactic factors c. ... coating of bacterial and tumor cells d. Increase of vascular permeability e. Phagocytosis of bacteria

Last Answer : Answer: a, b, c, d Platelets are anucleated cells derived from megakaryocytes in the bone marrow. Their central role in hemostasis is well known. Platelets possess a wide ... primitive precursor inflammatory cell. Platelets serve primarily as an amplifier or modulator of the inflammatory response

Description : Which of the following statements regarding TNFa are true? a. TNFa has a marked procoagulant effect b. Passive immunization of patients with neutralizing antibodies to TNFa improves survival from multi-organ ... expression d. The most potent known stimulus for TNFa production and release is IL-1

Last Answer : Answer: a, c TNFa has a marked procoagulant effect on endothelial cells, precipitating intravascular thrombosis. TNFa causes endothelial cells to release procoagulant activity (tissue factor), ... to produce TNFa, however the most potent stimulus for TNFa production and release is endotoxin

Description : Cytokines with clearly defined actions in acute inflammation and early tissue injury include which of the following? a. Cysteine-X-Cysteine (C-X-C) chemokines b. Tumor Necrosis Factor (TNFa) c. Transforming Growth Factor-b (TGF-b) d. Interleukin-6 (IL-6) e. Platelet Derived Growth Factor (PDGF)

Last Answer : Answer: a, b, c, d, e Polypeptide mediators, such as TNFa and IL-1, are considered early response cytokines and are actively involved in the initiation of the ... of tissue repair. Thus, coagulation and platelet activation provide the initial foundation for subsequent cellular recruitment

Description : The transport of proteins out of the cell is termed exocytosis. Which of the following statement(s) is/are true concerning this process? a. Secretory vesicles fuse with the plasma membrane b. ... or a neurotransmitter d. A decrease in cytoplasmic calcium occurs as part of the secretion process

Last Answer : Answer: a, b, c Transport vesicles that bud off the Golgi network carry both material to be secreted from the cell and protein destined to become components of the plasma ... but may also involve generation of diacylglycerol or production of cyclic AMP which activate kinases or phosphatases

Description : In contrast to adult wound healing with scar formation, which of the following are characteristic of scarless fetal skin repair? A. Matrix rich in hyaluronic acid. B. Increased inflammatory response. C. Increased production of TGF-b. D. No collagen deposition. E. Minimal angiogenesis.

Last Answer : Answer: AE DISCUSSION: The ability of a fetus to heal without scar formation depends on its gestational age at the time of injury and the size of the wound defect. In ... repair has possible clinical applications in the modulation of adult fibrotic diseases and abnormal scar-forming conditions

Description : Increasing evidence has implicated gram-negative bacterial lipopolysaccharide (LPS endotoxin) as the portion of the gram-negative bacterial cell membrane responsible for many, if not all the ... host, exerting deleterious effects on the host when excessive amounts reach the systemic circulation

Last Answer : Answer: a, b, d The LPS molecule exerts diverse effects on the mammalian host. Immunologic responses to LPS include nonspecific polyclonal B-cell proliferation, macrophage activation and ... deleterious effects on the host only after large amounts are secreted and reach the systemic circulation

Description : Which of the following statements regarding fibroblasts and their function in wound healing are true? a. IL-1 has both inhibitory and promotional effects on fibroblast growth b. TNFa ... EGF (epithelial growth factor) has been demonstrated to accelerate epidermal regeneration in cutaneous wounds

Last Answer : Answer: a, d IL-1 appears to be important in the process of normal wound repair. IL-1 has been shown to stimulate skin fibroblast and keratinocyte growth, as well as ... that recombinant EGF enhances keratinocyte migration. EGF is also a potent chemoattractant for granulation tissue fibroblasts

Description : Cytokines which play an important role in the metabolic response to injury include: a. Tumor necrosis factor—a (TNF) b. Interleukin-1 (IL-1) c. Interleukin-6 (IL-6) d. Interferon-g

Last Answer : Answer: a, b, c, d TNF or cachetin is considered the primary mediator of the systemic effects of endotoxin, producing anorexia, fever, tachypnea, and tachycardia at low doses and hypotension, ... infected sells. IFN-g has the ability to upregulate the number of TNF receptors on various cell types

Description : Which of the following statement(s) is/are true concerning the treatment of MOFS? a. Prevention and therapy of MOFS requires control of the infectious or inflammatory source b. Restoration of normal ... of the nature of gut injury, total parenteral nutrition is preferred for most patients with MOFS

Last Answer : Answer: a, c The therapy of MOFS is directed towards interrupting the involving pathophysiologic process and providing an optimal physiologic environment for healing and recovery. ... Enteral absorption and processing of nutrients appears superior to TPN and lessens overall complications

Description : Which of the following statement(s) is/are true concerning tumor necrosis factor (TNF)? a. TNF is a product of activated macrophages secreted in response to contact with endotoxin or ... completed clinical trials of anti-TNF antibody in septic patients shows a marked improvement in survival

Last Answer : Answer: a, b Tumor necrosis factor (TNF), a protein product of activated macrophages, is secreted in response to contact with endotoxin or lipopolysaccharide, antibody complexes, or ... patients utilizing infusion of monoclonal antibodies to the TNF molecule have shown no overall survival benefit

Description : Which of the following statement(s) is/are true concerning metabolic derangements in sepsis and the systemic inflammatory response syndrome which may follow progressive shock? a. Alterations in glucose ... The serum aromatic amino acids fall rapidly as they are actively used in oxidative metabolism

Last Answer : Answer: b, c A broad spectrum of metabolic abnormalities become apparent in sepsis and the systemic inflammatory response syndrome following shock. Disruption of the normal cycles of carbohydrate, ... acetyl coenzyme A. This results in reduced serum level of leucine, isoleucine and valine

Description : Ketorolac: A. Is a nonsteroidal anti-inflammatory drug (NSAID) approved for intravenous, intramuscular, and oral administration. B. Can be used indefinitely for postoperative analgesia. C. Can cause renal dysfunction. D. May decrease surgical blood loss.

Last Answer : Answer: AC DISCUSSION: Ketorolac tromethamine, an NSAID, is approved by the FDA for intravenous, intramuscular, and oral administration. The agent is an effective analgesic with minimal side ... Additionally, it is recommended that ketorolac should not be used for more than 5 consecutive days

Description : True statements regarding eicosanoids include which of the following? A. Prostaglandins and thromboxanes are synthesized via the cyclo-oxygenase pathway. B. The vasoconstricting, platelet-aggregating, ... prostaglandins have a short circulation half-life and exert most of their effects locally.

Last Answer : Answer: ABD DISCUSSION: The eicosanoids are a group of compounds arising from the metabolism of arachidonic acid. The prostaglandins and thromboxanes are synthesized via the cyclo-oxygenase ... effects and may be involved in the physiologic responses associated with anaphylactic and septic shock

Description : In addition to their ability to decrease inflammatory prostaglandin synthesis, some non-steroidal anti-inflammatory drugs (NSAIDs) may owe part of their effects to their ability to (a) Inhibit leukocyte migration (b ... (c) Stabilize lysosmal membranes (d) All of the above (e) None of the above

Last Answer : Ans: D

Description : Which of the following statement(s) is/are true concerning the vascular response to injury? a. Vasoconstriction is an early event in the response to injury b. Vasodilatation is a ... Histamine, prostaglandin E2 (PGE2) and prostacyclin (PGI2) are important mediators of local vasoconstriction

Last Answer : Answer: a After wounding, there is transient vasoconstriction mediated by catecholamines, thromboxane, and prostaglandin F2 (PGF2a). This period of vasoconstriction lasts for only five to ten minutes. Once ... and mast cells and enhance the egress of cells and substrate into the wound and tissue

Description : Which of the following statement(s) is/are true concerning the role of glutamine in total parenteral nutrition? a. Glutamine is an essential amino acid b. Glutamine appears to be of primary ... . Glutamine is the primary energy source for intestinal mucosal cells of the small bowel and colon

Last Answer : Answer: b Glutamine is the most studied gut-specific nutrient. Glutamine has been classified as a nonessential or nutritionally dispensable amino acid since glutamine can be synthesized in adequate ... . In contrast to glutamine, short chain fatty acids are primary energy source for colonocytes

Description : Which of the following statement(s) is/are true concerning the cell plasma membrane? a. The plasma membrane is composed of amphipathic molecules b. The hydrophobic core of the lipid bilayer of the ... contribute to the cell coat d. The membrane proteins of nerve cells are highly voltage-dependent

Last Answer : Answer: a, b, d The plasma membrane defines the boundary of the cell and serves to contain and concentrate enzymes and other macromolecule constituents. The plasma membrane is ... and bear carbohydrate moieties primarily as oligosaccharide chains that contribute to the cell coat or glycocalyx

Description : Which of the following is/are true concerning wound fibroblasts? A. Fibroblasts synthesize and secrete collagen molecules. B. Wound fibroblasts are derived from blood-borne precursor cells. C. ... clot can act as a physical barrier to fibroblast penetration, which delays normal wound healing.

Last Answer : Answer: ACD DISCUSSION: Fibroblasts appear in the wound on about the third day of healing and begin to synthesize and secrete collagen molecules. Wound fibroblasts arrive from cells surrounding ... enzymes, and large amounts of fibrin and blood clot prevent fibroblasts from entering the wound

Description : Which of the following statements regarding the complement system are true? a. Complement activation yields products which are directly cytotoxic as well as products which act indirectly via activated ... and classical pathways converge proximal to generating the membrane attack complex (C5b-9)

Last Answer : Answer: a, d The complement system is composed of two different but linked sequences, the classic and alternative pathways. The pathways involve serum proteins that act to amplify the inflammatory-immune ... the C5 level proximal to generating the membrane attack complex (C5b-9) (Figure 6-3)

Description : Fibrinolytic therapy is based on activation of plasminogen, the inactive proteolytic enzyme of plasma that binds to fibrin during the formation of thrombosis. Activation of plasminogen to plasmin results ... TPA all exceed 30 minutes d. Streptokinase is significantly cheaper than urokinase or TPA

Last Answer : Answer: a, b, d Streptokinase is a bacterial protein produced by group C b-hemolytic streptococci. It is therefore antigenic in humans and can be associated with allergic reaction in ... one agent over the other. Streptokinase however, is markedly less expensive than either urokinase or TPA

Description : The best understood intracellular messenger is cyclic AMP (cAMP). Which of the following statement(s) concerning this intracellular messenger is/are correct? a. Intracellular cyclic AMP is constantly ... of adenylate cyclase d. cAMP is the only cyclic nucleotide active as an intracellular messenger

Last Answer : Answer: a, b The prototypic intracellular messenger is cAMP. To function as a mediator, the concentration of cAMP must change rapidly. In resting cells, cAMP is continuously being degraded by ... produce cGMP. Intracellular calcium ions also serve as second messengers in a large number of cells

Description : Which of the following statements about the coagulation cascade is/are true? A. The intrinsic pathway of coagulation is the predominant pathway in vivo for hemostasis and coagulation. ... coagulation abnormalities. D. Deficiencies of factor XII cause severe clinical bleeding syndromes.

Last Answer : Answer: AC DISCUSSION: Although it was previously held that two somewhat distinct pathways existed for the activation of the coagulation cascade, it is now recognized that the predominant ... bleeding. This further emphasizes the secondary role that the intrinsic pathway plays in coagulation

Description : Which of the following factors can be associated with impaired wound healing? a. Chemotherapy b. Chronic steroid use c. Peripheral vascular disease d. Radiation therapy e. Diabetes mellitus

Last Answer : Answer: a, b, c, d, e Bone marrow suppression, a common consequence of chemotherapy, is detrimental to wound healing. Quantitative and qualitative lymphocyte and monocyte deficiency impairs cellular ... be a primary cause of impaired healing, and may be also a cofactor with other conditions

Description : The following are true about chemicals involved in allergic reaction: a. thromboxane -leukocyte activation b. prostaglandin-2 - vasodilatation c. platelet-activating factor - leukocyte activation d. heparin - augments inactivation of prostaglandins

Last Answer : prostaglandin-2 - vasodilatation

Description : The blood-brain-barrier: a. contains the foot processes of astrocytes b. contains endothelial cells with tight junction c. allows transport in one direction only ie from the vascular system into the brain d. does not allow diffusion of water

Last Answer : does not allow diffusion of water

Description : With regard to the blood retina barrier: a. the outer blood retina is formed by the retinal pigment epithelium cells and their junctions b. the blood retina barrier is typically defective in the ... fluid and anions from the extracellular space of the retina into the circulation d. all above

Last Answer : all above

Description : Which of the following statement(s) is/are correct concerning the cardiovascular response to shock? a. Changes in cardiac contractile function shift the Frank Starling curve up and down b. ... d. The total circulating blood volume is equally split between the arterial and venous system

Last Answer : Answer: a Central in the general cardiovascular response to shock is the action of the heart itself. The principle determinants of cardiac function in the normal heart are the volume of blood ... Blood flow to the skin is sacrificed early, followed by that to the kidneys and splanchnic viscera

Description : A 68-year-old male who underwent a repair of an abdominal aortic aneurysm 5 days ago, develops tachycardia, tachypnea, hypotension with cool, pale, mottled cyanotic extremities. He ... use of moderate doses of inotropic agents e. Afterload reduction with nitroprusside is absolutely contraindicated

Last Answer : Answer: a, b, d Intrinsic cardiogenic shock results from failure of the heart as an effective pump. Coronary artery disease is the most common cause of myocardial ... hemodynamic monitoring. Infusion of afterload-reducing agents can be administered in conjunction with inotropic support