WebPath Inflammation
14. A small sliver of wood becomes embedded in the finger of a 25-year-old man. He does not remove it, and over the next 3 days the area around the sliver becomes red, swollen, and tender. Neutrophils migrate into the injured tissue. Expression of which of the following substances on endothelial cells is most instrumental in promoting this inflammatory reaction? A Interferon gamma B Hageman factor C Lysozyme D E-selectin E Prostacyclin
(D) CORRECT. Selectins are adhesive molecules expressed on endothelial cell surfaces and attract leukocytes, mainly neutrophils. P-selectin is expressed rapidly, while E-selectin is expressed within several hours.
23. Within minutes following a bee sting, a 37-year-old man develops marked respiratory stridor with dyspnea and wheezing. He also develops swelling and erythema seen in his arms and legs. An injection of epinephrine helps to reverse these events and he recovers within minutes. Which of the following chemical mediators is most important in the pathogenesis of this man's condition? A Bradykinin B Complement C5a C Nitric oxide D Tumor necrosis factor E Histamine
(E) CORRECT. This is systemic anaphylaxis, a type I hypersensitivity reaction in which the antigen contacts preformed IgE antibody attached to mast cells, leading to mast cell degranulation with release of bioactive compounds such as histamine and production of symptoms. The initial response typically occurs within minutes.
9. A 43-year-old woman has had a chronic cough with fever and weight loss for the past month. A chest radiograph reveals multiple nodules from 1 to 4 cm in size, some of which demonstrate cavitation in the upper lobes. A sputum sample reveals the presence of acid fast bacilli. Which of the following cells is the most important in the development her lung lesions? A Macrophage B Fibroblast C Neutrophil D Mast cell E Platelet
(A) CORRECT. Epithelioid cells and giant cells are derived from activated macrophages. Tissue macrophages are derived from blood monocytes. These cells are important in the development of granulomatous inflammation in the adaptive immune response to tuberculosis.
15. An inflammatory process that has continued for 3 months includes the transformation of tissue macrophages to epithelioid cells. There are also lymphocytes present. Over time, fibroblasts lay down collagen as the focus of inflammation heals. These events are most likely to occur as an inflammatory response to which of the following infectious agents? A Mycobacterium tuberculosis B Pseudomonas aeruginosa C Cytomegalovirus D Giardia lamblia E Treponema pallidum
(A) CORRECT. Mycobacterial organisms are difficult to kill, because of their lipid coat of mycolic acid. Hence a neutrophilic response has little effect. This persistent infection requires macrophage activation that leads to granuloma formation.
33. A 65-year-old woman has had a fever for the past day. On physical examination her temperature is 39°C and blood pressure 90/50 mm Hg with heart rate of 106/minute. Laboratory studies show a WBC count of 12,510/microliter and WBC differential count of 78 segs, 8 bands, 11 lymphs, and 3 monos. A blood culture is positive for Escherichia coli. Her central venous pressure falls markedly. She goes into hypovolemic shock as a result of the widespread inappropriate release of a chemical mediator derived from macrophages. She develops multiple organ failure. Which of the following mediators is most likely to produce these findings? A Nitric oxide B Bradykinin C Histamine D Prostacyclin E Complement C3a
(A) CORRECT. Nitric oxide (NO) acts as a vasodilator. Small amounts released from endothelial cells causes vasodilation and prevents thrombosis. Macrophages release NO to kill bacteria, but large amounts released body-wide can cause hypotension and shock.
35. A 19-year-old man incurs a stab wound to the chest. The wound is treated in the emergency room. Two months later there is a firm, 3 x 2 cm nodular mass with intact overlying epithelium in the region of the wound. On examination the scar is firm, but not tender, with no erythema. This mass is excised and microscopically shows fibroblasts with abundant collagen. Which of the following mechanisms has most likely produced this series of events? A Keloid formation B Development of a fibrosarcoma C Poor wound healing from diabetes mellitus D Foreign body response from suturing E Staphyloccocal wound infection
(A) CORRECT. Some persons have an exaggerated, inappropriate wound healing response with excessive collagenization.
25. In an experiment, Enterobacter cloacae organisms are added to a solution containing leukocytes and blood plasma. Engulfment and phagocytosis of the microbes is observed to occur. Next a substance is added which enhances engulfment, and more bacteria are destroyed. Which of the following substances in the plasma is most likely to produce this effect? A Complement C3b B Glutathione peroxidase C Immunoglobulin M D P-selectin E NADPH oxidase
(A) CORRECT. The C3b fragment generated from the complement cascade serves as an effective opsonin, attaching to the bacteria so that phagocytes will find and engulf them more easily.
40. A 56-year-old man has had increasing difficulty breathing for the past week. On physical examination he is afebrile. Auscultation of his chest reveals diminished breath sounds and dullness to percussion bilaterally. There is 2+ pitting edema present to the level of his thighs. A chest radiograph reveals bilateral pleural effusions. Which of the following laboratory test findings is he most likely to have? A Hypoalbuminemia B Glucosuria C Neutrophilia D Anemia E Hypernatremia
(A) CORRECT. The decrease in oncotic pressure from decreased serum albumin, the blood protein that accounts for most of the oncotic pressure, can be significant. This can be a cause for edema and fluid transudates. Too little circulating protein doesn't keep in or draw water into the vasculature.
31. A 31-year-old woman has a laparotomy performed for removal of an ovarian cyst. She recovers uneventfully, with no complications. At the time of surgery, a 12 cm long midline abdominal incision was made. The tensile strength in the surgical scar will increase so her normal activities can be resumed. Most of the tensile strength will likely be achieved in which of the following time periods? A One week B One month C Three months D Six months E One year
(C) CORRECT. About 70 to 80% of the tensile strength in the scar, compared to non-wounded skin, is reached at 3 months, which is about as much as will be obtained.
19. A 45-year-old woman has had a chronic, non-productive cough for 3 months, along with intermittent fever. She has a chest radiograph that reveals multiple small parenchymal nodules along with hilar and cervical lymphadenopathy. A cervical lymph node biopsy is performed. Microscopic examination of the biopsy shows noncaseating granulomatous inflammation. Cultures for bacterial, fungal, and mycobacterial organisms are negative. Which of the following chemical mediators is most important in the development of her inflammatory response? A Interferon gamma B Bradykinin C Complement C5a D Histamine E Prostaglandin E2
(A) CORRECT. This non-caseating granulomatous inflammation is typical for sarcoidosis, a non-infectious process. Granulomas are a form of type IV hypersensitivity reaction. There are cytokines such as interferon gamma produced by lymphocytes that recruit blood monocytes and stimulate macrophages to develop a granulomatous response.
22. A 45-year-old man has been working hard all day long carrying loads of bricks to build a wall. He takes a non-steroidal anti-inflammatory drug (ibuprofen). Which of the following processes is this drug most likely to diminish in his arms? A Thrombosis B Pain C Necrosis D Fibrinolysis E Scar formation
(B) CORRECT. Aspirin, indomethacin, and NSAIDS block the cyclo-oxygenase arm of the arachidonic acid pathway, which generates the prostaglandins that play a role in development of pain as a consequence of the inflammatory process. The inflammation here is minimal but widespread as a consequence of the overuse of the connective tissues in the arms.
7. A 22-year-old woman has premature labor with premature rupture of fetal membranes at 20 weeks gestation. Prior to that time, the pregnancy had been proceeding normally. A stillbirth occurs two days later. Microscopic examination of the normal-sized placenta reveals numerous neutrophils in the amnion and chorion, but no villitis. The premature labor was most likely mediated by the effects from release of which of the following substances? A Immunoglobulin B Prostaglandin C Complement D Fibrinogen E Lymphokines
(B) CORRECT. Prostaglandins are mediators of acute inflammation that promote labor through effects on smooth muscle and blood vessels.
12. A 94-year-old woman has developed a fever and cough over the past 2 days. Staphylococcus aureus is cultured from her sputum. She receives a course of antibiotic therapy. Two weeks later she no longer has a productive cough, but she still has a fever. A chest radiograph reveals a 3 cm rounded density in the right lower lobe whose liquefied contents form a central air-fluid level. There are no surrounding infiltrates. Which of the following is the best description for this outcome of her pneumonia? A Hypertrophic scar B Abscess formation C Regeneration D Bronchogenic carcinoma E Chronic inflammation F Granulomatous cavitation
(B) CORRECT. The formation of a fluid filled cavity following an infection with S. aureus suggests that liquefactive necrosis has occurred. The cavity is filled with tissue debris and viable and dead neutrophils (pus). Localized, pus filled cavities are called abscesses. The liquified contents seek a level (air-fluid level).
36. A 45-year-old man has had a fever and dry cough for 3 days, and now has difficulty breathing and a cough productive of sputum. On physical examination his temperature is 38.5°C. Diffuse rales are auscultated over lower lung fields. A chest radiograph shows a right pleural effusion. A right thoracentesis is performed. The fluid obtained has a cloudy appearance with a cell count showing 15,500 leukocytes per microliter, 98% of which are neutrophils. Which of the following terms best describes his pleural process? A Serous inflammation B Purulent inflammation C Fibrinous inflammation D Chronic inflammation E Granulomatous inflammation
(B) CORRECT. The neutrophils suggest an acute inflammatory process; the fluid is characteristic for an exudate. Such a large amount of purulent exudate in the pleural space can be termed an empyema.
5. A clinical study is performed of patients with pharyngeal infections. The most typical clinical course averages 3 days from the time of onset until the patient sees the physician. Most of these patients experience fever and chills. On physical examination, the most common findings include swelling, erythema, and pharyngeal purulent exudate. Which of the following types of inflammation did these patients most likely have? A Granulomatous B Acute C Gangrenous D Resolving E Chronic
(B) CORRECT. The short course of days and the purulent exudate are typical features of acute inflammation with a neutrophilic response, most often caused by a bacterial organisms such as group A Streptococcus. Lacking evidence for an acute bacterial infection, avoid use of antibiotics.
3. A 39-year-old man incurs a burn injury to his hands and arms while working on a propane furnace. Over the next 3 weeks, the burned skin heals without the need for skin grafting. Which of the following is the most critical factor in determining whether the skin in the region of the burn will regenerate? A Good cardiac output with tissue perfusion B Persistence of skin appendages C Maintenance of underlying connective tissue D Diminished edema and erythema E Granulation tissue formation
(B) CORRECT. The skin appendages have epithelium from which the surface epidermis can regenerate. A partial thickness burn retains epithelial elements in the skin. This is why a full thickness burn is much worse and requires grafting.
24. A 72-year-old woman did not get a 'flu' shot in the fall as recommended for older persons. In the wintertime, she became ill, as many people in her community did, with a respiratory illness that lasted for 3 weeks. During this illness, she had a fever with a non-productive cough, mild chest pain, myalgias, and headache. What was her chest radiograph most likely to have shown during this illness? A Hilar mass B Interstitial infiltrates C Hilar lymphadenopathy D Lobar consolidation E Pleural effusions
(B) CORRECT. Viral illnesses, including those caused by common viral respiratory pathogens such as influenza, often produce chronic inflammation that is mainly interstitial in the lungs. The lack of an alveolar filling process results in the lack of a productive cough.
29. A 55-year-old man with a history of ischemic heart disease has worsening congestive heart failure. He has noted increasing dyspnea and orthopnea for the past 2 months. On physical examination there is dullness to percussion at lung bases. A chest x-ray shows bilateral pleural effusions. A left thoracentesis is performed, and 500 mL of fluid is obtained. Which of the following characteristics of this fluid would most likely indicate that it is a transudate? A Cloudy appearance B High protein content C <3 lymphocytes/microliter D Presence of fibrin E Large size of the effusion
(C) CORRECT. A transudate resembles a filtrate of plasma and has few cells with very little protein and has a clear appearance.
33. A 20-year-old woman sustains an injury to her right calf in a mountain biking accident. On physical examination she has a 5 cm long laceration on the right lateral aspect of her lower leg. This wound is closed with sutures. Wound healing proceeds over the next week. Which of the following factors will be most likely to aid and not inhibit wound healing in this patient? A Commensal bacteria B Decreased tissue perfusion C Presence of sutures D Corticosteroid therapy E Hypoalbuminemia
(C) CORRECT. Although any foreign body will delay wound healing to some degree, the net effect of having sutures is to aid the process of healing more than to hinder it, since the sutures close the wound, so there is less space to fill in by granulation tissue, and less distance for cells to move.
27. In an experiment, lymphatic channels are observed in normal soft tissue preparations. Staphylococcus aureus organisms are innoculated into the tissues and the immunologic response observed over the next 24 hours. Which of the following functions is most likely to be served by these lymphatics to produce a specific immune response to these organisms? A Carry lymphocytes to peripheral tissue sites B Remove extravascular tissue fluid C Transport antigen presenting cells D Serve as a route for dissemination of infection E Provide an emigration point for neutrophils
(C) CORRECT. Antigen presenting cells such as dendritic cells and macrophages which have trapped antigen in peripheral tissues can be transported to lymph nodes where they encounter specific clones of memory cells capable of responding to those specific antigens, and this typically happens within a day.
39. In an experiment, a lung tissue preparation is exposed to Mycobacterium tuberculosis organisms. Over the next week, it is observed that granulomas form in the lung. Within the granuloma are found inflammatory cells expressing class II MHC antigens. These cells elaborate cytokines that promote fibroblastic production of collagen within the granulomas. From which of the following peripheral blood leukocytes are these cells bearing class II antigen most likely to be derived? A Neutrophils B B cells C Monocytes D NK cells E Basophils
(C) CORRECT. Blood monocytes can migrate into tissues and become macrophages. Macrophages play an important role in delayed hypersensitivity reactions with cell-mediated immunity.
30. In a clinical study, patients undergoing laparoscopic cholecystectomy are followed to document the post-surgical wound healing process. The small incisions are closed with sutures. Over the 4 weeks following surgery, the wounds are observed to regain tensile strength and there is re-epithelialization. Of the following substances, which is most likely found to function intracellularly in cells involved in this wound healing process? A Fibronectin B Laminin C Tyrosine kinase D Hyaluronic acid E Collagen
(C) CORRECT. Cell surface growth factor receptors recruit intracellular protein kinases that begin a sequence of events leading to cell division and growth.
13. A 36-year-old woman has been taking acetylsalicylic acid (aspirin) for arthritis for the past 4 years. Her joint pain is temporarily reduced via this therapy. However, radiographs of her knees reveals continuing joint destruction with loss of articular cartilage and joint space narrowing. This pain reduction is most likely to be the result of diminishing which of the following chemical mediators? A Leukotriene B4 B Interleukin-1 C Prostaglandin D Bradykinin E Hageman factor
(C) CORRECT. Prostaglandins are produced via the cyclooxygenase pathway of arachidonic acid metabolism. Aspirin and non-steroidal anti-inflammatory drugs block the synthesis of prostaglandins that produce pain. Acetaminophen, which does not have the effect upon platelets that aspirin does, would be a better choice for the arthritis pain.
34. A 24-year-old primigravida is late in the second trimester of pregnancy. She experiences the sudden onset of some cramping lower abdominal pain. This is immediately followed by passage of some fluid per vagina along with a foul-smelling discharge. The fetus is stillborn two days later. Examination of the placenta demonstrates extensive neutrophilic infiltrates in the chorion and amnion. Which of the following organisms is most likely to be responsible for these findings? A Mycobacterium tuberculosis B Herpes simplex virus C Escherichia coli D Treponema pallidum E Toxoplasma gondii
(C) CORRECT. She developed an acute chorioamnionitis, and bacterial infections that precede or follow premature rupture of membranes are most often to blame. Bacterial infections tend to elicit neutrophilic inflammatory responses.
17. A 17-year-old truck driver is involved in a collision. He incurs blunt force abdominal trauma. In response to this injury, cells in tissues of the abdomen are stimulated to enter the G1 phase of the cell cycle from the G0 phase. Which of the following cell types is most likely to remain in G0 following this injury? A Smooth muscle B Endothelium C Skeletal muscle D Fibroblast E Hepatocyte
(C) CORRECT. Skeletal and cardiac muscle cells do not typically proliferate in response to injury, and necrotic cells are replaced by connective tissue. Remaining striated muscle cells, however, can undergo hypertrophy.
2. A 40-year-old woman had laparoscopic surgery 3 months ago. Now she has a small 0.5 cm nodule beneath the skin at the incision site that was sutured. Which of the following cell types is most likely to be most characteristic of the inflammatory response in this situation? A Mast cell B Eosinophil C Giant cell D Neutrophil E Plasma cell
(C) CORRECT. The suture is a foreign material and produces a foreign body reaction. Persistence of the stimulus recruits macrophages that are activated and transformed to giant cells, in this case foreign body giant cells.
20. A 55-year-old man has a history of hypercholesterolemia with coronary artery disease and suffered a myocardial infarction 2 years ago. He now presents with crushing substernal chest pain. Which of the following laboratory tests is most useful in diagnosing the cause of his chest pain? A Increased white blood cell count B Elevated sedimentation rate C Decreased serum complement D Increased serum creatine kinase E Decreased platelet count F Increased serum cholesterol
(D) CORRECT. CK is an enzyme released from the damaged striated muscle. CK-MB would be more specific for cardiac muscle, while CK-MM mainly comes from skeletal muscle. Cell damage leads to leakage of intracellular contents, such as enzymes. Some enzymes are more specific for certain tissues to aid in diagnosis.
28. In an experiment, surgical wound sites are observed following suturing. An ingrowth of new capillaries is observed to occur within the first week. A substance elaborated by macrophages is found at the wound site to stimulate this capillary proliferation. Which of the following substances is most likely to have this function? A Platelet-derived growth factor B Phospholipase C-gamma C Fibronectin D Fibroblast growth factor E Epidermal growth factor
(D) CORRECT. FGF can stimulate all aspects of angiogenesis.
32. A 9-year-old girl sustains a small 0.5 cm long laceration to her right index finger while playing 'Queen of Swords' with a letter opener. Which of the following substances, on contact with injured vascular basement membrane, activates both the coagulation sequence and the kinin system as an initial response to this injury? A Thromboxane B Plasmin C Platelet activating factor D Hageman factor E Histamine
(D) CORRECT. Hageman factor (factor XII as measured in the intrinsic coagulation pathway) becomes activated upon contact with injured, exposed vascular basement membrane.
21. A 15-year-old girl has had episodes of sneezing with watery eyes and runny nose for the past 2 weeks. On physical examination she has red, swollen nasal mucosal surfaces. She has had similar episodes each Spring and Summer when the amount of pollen in the air is high. Her symptoms are most likely to be mediated by the release of which of the following chemical mediators? A Complement C3b B Platelet activating factor (PAF) C Tumor necrosis factor (TNF) D Histamine E Immunoglobulin G
(D) CORRECT. Histamine, mainly released from mast cells in perivascular locations in the submucosa beneath the nasal respiratory epithelium, leads to vasodilation and fluid exudation. That is why people with allergies take antihistamines.
8. After two weeks in the hospital following a fall in which she incurred a fracture of her left femoral trochanter, a 76-year-old woman now has a left leg that is swollen, particularly her lower leg below the knee. She experiences pain on movement of this leg, and there is tenderness to palpation. Which of the following complications is most likely to occur next after these events? A Gangrenous necrosis of the foot B Hematoma of the thigh C Disseminated intravascular coagulation D Pulmonary thromboembolism E Soft tissue sarcoma
(D) CORRECT. She has deep and superficial venous thrombosis as a consequence of venous stasis from immobilization following the accident. The large deep venous thrombi can embolize to the lungs and lead to death.
A 22-year-old man develops marked right lower quadrant abdominal pain over the past day. On physical examination there is rebound tenderness on palpation over the right lower quadrant. Laparoscopic surgery is performed, and the appendix is swollen, erythematous, and partly covered by a yellowish exudate. It is removed, and a microscopic section shows infiltration with numerous neutrophils. The pain experienced by this patient is predominantly the result of which of the following two chemical mediators? A Complement C3b and IgG B Interleukin-1 and tumor necrosis factor C Histamine and serotonin D Prostaglandin and bradykinin E Leukotriene and HPETE
(D) CORRECT. The findings are those of acute appendicitis. The acute inflammation is marked by neutrophil exudation. Release of a variety of chemical mediators results in the findings associated with inflammation: calor (warmth), rubor (erythema), tumor (swelling), and dolor (pain). The analgesic aspirin, by inhibiting the cyclooxygenase pathway, can decrease prostaglandin synthesis.
6. A 56-year-old man has had increasing dyspnea for 6 years. He has no cough or fever. He had chronic exposure to inhalation of silica dust for many years in his job. A chest x-ray now shows increased interstitial markings and parenchymal 1 to 3 cm solid nodules. His pulmonary problems are most likely to be mediated through which of the following inflammatory processes? A Neutrophilic infiltrates producing leukotrienes B Foreign body giant cell formation C Plasma cell synthesis of immunoglobulins D Mast cell histamine release E Macrophage elaboration of cytokines
(E) CORRECT. Cytokines including growth factors are released from macrophages that have ingested silica crystals, and these factors stimulate collagen production by fibroblasts, producing interstitial fibrosis and nodule formation that reduces and restricts the amount of normal lung parenchyma and makes breathing more difficult.
4. A 58-year-old woman has had a cough with fever for 3 days. A chest radiograph reveals infiltrates in the right lower lobe. A sputum culture grows Streptococcus pneumoniae. The clearance of these organisms from the lung parenchyma would be most effectively accomplished through generation of which of the following substances by the major inflammatory cell type responding to this infection? A Platelet activating factor B Prostaglandin E2 C Kallikrein D Leukotriene B4 E Hydrogen peroxide
(E) CORRECT. Hydrogen peroxide is reduced by myeloperoxidase to a powerful oxidant that kills bacteria. She has an acute inflammatory response to a bacterial organism, and the majority of inflammatory cells responding will be neutrophils.
18. A 19-year-old woman is in the early second trimester at 16 weeks gestation with her first pregnancy. On a routine prenatal visit, the nurse cannot detect fetal heart tones and an ultrasound reveals no fetal cardiac activity or fetal movement. The mother has noted no recent illness or other factors for this fetal demise. She is given a pharmacologic agent to induce abortion. By which of the following mechanisms is this induction most likely to be accomplished? A Leukotriene-induced neutrophil aggregation B Complement-induced hemolysis C Histamine-induced edema D Endotoxin-induced disseminated intravascular coagulation E Prostaglandin-induced muscular contraction
(E) CORRECT. Prostaglandins are generated through the cyclooxygenase pathway of arachidonic acid metabolism and induce smooth muscle contraction in the uterus for induction to expel the fetus.
10. A 20-year-old man has experienced painful urination for 4 days. A urethritis is suspected, and Neisseria gonorrheae is cultured. Numerous neutrophils are present in a smear of the exudate from the penile urethra. These neutrophils undergo diapedesis to reach the organisms. Release of which of the following chemical mediators is most likely to drive neutrophil exudation? A Histamine B Prostaglandin C Hageman factor D Bradykinin E Complement
(E) CORRECT. The C5a component of complement, along with TNF, leukotrienes, and bacterial products, is chemotactic for neutrophils.
11. An episode of marked chest pain lasting 4 hours brings a 51-year-old man to the emergency room. He is found to have an elevated serum creatine kinase. An angiogram reveals a complete blockage of the left circumflex artery 2 cm from its origin. Which of the following substances would you most expect to be elaborated around the region of tissue damage in the next 3 days as an initial response to promote healing? A Histamine B Immunogloblulin G C Complement component C3b D Leukotriene B4 E Vascular endothelial growth factor
(E) CORRECT. The VEGF stimulates angiogenesis to aid in establishing collateral circulation and restoring blood flow to the myocardium in this patient with an acute myocardial infarction.
38. A 52-year-old woman with no major medical problems takes a long airplane flight across the Pacific Ocean. Upon arrival at Sydney's Kingsford Smith airport following the flight from Los Angeles, she cannot put her shoes back on. There is no pain or tenderness. Which of the following is the most likely explanation for this phenomenon? A Activation of Hageman factor has led to bradykinin production. B A lot of drinks were served in the first class section. C Femoral vein thrombosis developed. D A cellulitis developed in her legs. E Venous hydrostatic pressure became increased.
(E) CORRECT. The longest non-stop flight in the world has its drawbacks. Extracellular fluid builds up when hydrostatic pressure is increased over a long time. Remaining upright and stationary in a cramped airplane predisposes to reduced venous and lymphatic return.
16. A 37-year-old man has had nausea and vomiting for 5 weeks. He experienced an episode of hematemesis yesterday. On physical examination he has no abnormal findings. Upper GI endoscopy is performed, and there is a 1.5 cm diameter lesion in the gastric antrum with loss of the epithelial surface. These findings are most typical for which of the following pathologic processes? A Abscess B Serositis C Granuloma D Gangrene E Ulcer
(E) CORRECT. The loss of an epithelial surface with inflammation is called an ulceration. The presence of hydrochoric acid in the stomach promotes this process when epithelial injury occurs.
26. A 43-year-old woman has had nausea with vomiting persisting for the past 5 weeks. On physical examination there are no abnormal findings. She undergoes an upper GI endoscopy and gastric biopsies are obtained. The microscopic appearance of these biopsies shows mucosal infiltration by lymphocytes, macrophages, and plasma cells. Which of the following most likely caused her findings? A Staphylococcus aureus septicemia B Ingestion of chili peppers C Diabetes mellitus D Tuberculosis E Infection with Helicobacter pylori
(E) CORRECT. This is a chronic inflammatory process, based upon the mononuclear inflammatory cell components present. H. pylori organisms live in the mucus above the gastric epithelium and release chemical substances that alter epithelial function and defenses, leading to gastritis. This organism does not directly infect or damage the epithelium, and its persistence leads to the chronic inflammation.