BRS 2 Flashcards
A 72-year-old man presents with a 3-day history of progressively worsening produc- tive cough, fever, chills, and signs of toxicity. Prominent physical findings include signs
of consolidation and rales over the right lung base. Sputum culture is positive for Streptococcus pneumoniae. An intra-alveolar exudate filling the alveoli of the involved portion of the lung is present. Which of the following types of inflammatory cells is most likely a prominent feature of this exudate?
(A) Basophils
(B) Eosinophils
(c) Lymphocytes
(d) Monocytes–macrophages
(e) Neutrophils
the answer is e. The patient has bacterial pneumonia due to Streptococcus pneumoniae, a classic example of severe acute inflammation. In the early stages of acute inflammation, the neutrophil is the most prominent inflammatory cell. It is noteworthy that, in many instances, bacterial infections are characterized by neutrophilic infiltrates. It is also note- worthy that S. pneumoniae (also known as the “pneumococcus”) is the most common etiologic agent of lobar pneumonia (see Chapter 14).
A routine complete blood count per- formed on a 22-year-old medical student reveals an abnormality in the differential leukocyte count. She has been complain- ing of frequent sneezing and “watery” eyes during the past several weeks and reports that she frequently had such episodes in the spring and summer. Which of the following cell types is most likely to be increased? (A) Basophils (B) Eosinophils (c) Lymphocytes (d) Monocytes (e) Neutrophils
the answer is B. This type of reaction is primarily mediated by the release of histamine from tissue mast cells, and the associated cellular infiltrate and peripheral blood findings represent mobilization and increased numbers of eosinophils. The symptoms reported are those of seasonal rhinitis, better known as “hay fever,” a manifestation of type I hypersensitivity (see Chapter 5).
A 16-year-old boy presents with a 24-hour history of severe abdominal pain, nausea, vomiting, and low-grade fever. The pain is initially periumbilical in location but has migrated to the right lower quadrant of the abdomen, with maximal tenderness elic- ited at a site one-third of the way between the crest of the ileum and the umbilicus (McBurney point). The leukocyte count is 14,000/mm3, with 74% segmented neutro- phils and 12% bands. Surgery is performed. Which of the following describes the expect- ed findings at the affected site?
(A) Fistula (abnormal duct or passage) con- necting to the abdominal wall
(B) Granulation tissue (new vessels and young fibroblasts) with a prominent infiltrate of eosinophils
(c) Granulomatous inflammation with prominent aggregates of epithelioid cells and multinucleated giant cells
(d) Massive infiltration of lymphocytes and plasma cells
(e) Prominent areas of edema, congestion, and a purulent reaction with localized areas of abscess formation
the answer is e. The clinical findings are typical of acute appendicitis, another example of severe acute inflammation. Because the danger of perforation is great, early appendec- tomy is the treatment of choice. Suppurative or purulent inflammation is characterized by the prominent areas of edema resulting from increased vascular permeability, conges- tion, and a purulent (pus-containing) exudate consisting of necrotic cells and large num- bers of neutrophils. In addition, other signs of acute inflammation, such as congestion, are prominent. The patient responds with the sensation of pain (induced by increased hydrostatic pressure in tissue and by chemical mediators such as bradykinin) and the acute phase reaction (in this instance, fever and neutrophilic leukocytosis with a “shift to the left”).
A 2-year-old boy presents with recur- rent infections involving multiple organ systems. Extensive investigation results in a diagnosis of chronic granulomatous disease of childhood. Which of the following most closely characterizes the abnormality in this patient’s phagocytic cells?
(A) Decreased killing of microorganisms because of enhanced production of hydrogen peroxide
(B) Deficiency of NADPH oxidase activity (c) Impaired chemotaxis and migration
caused by abnormal microtubule
formation
(d) Inability to kill streptococci
(e) Increased myeloperoxidase–halide-
mediated killing of catalase-positive organisms when compared with catalase-negative organisms
the answer is B. Chronic granulomatous disease of childhood, a condition characterized by repeated infections and most commonly X-linked inheritance, is marked by failure
of the myeloperoxidase–halide system of killing within phagocytic cells. It is caused by the deficiency of NADPH oxidase activity. This results in a secondary deficiency of reac- tive oxygen metabolites, including H2O2, which, along with halide ions, functions as a substrate for myeloperoxidase. A hallmark of the disorder is the failure of intracellular killing of catalase-positive organisms, exemplified by staphylococci. These organisms are ingested but not killed. The impaired phagocytic cell is incapable of producing H2O2, and any H2O2 produced by the microorganism itself is inactivated by endogenous catalase. In contrast, catalase-negative microorganisms, such as streptococci, are ingested and killed. They too produce endogenous H2O2, which is thus available as one of the substrates for myeloperoxidase. In a sense, the microorganisms assist in their own killing.
The accompanying figure is representative of the findings in a hilar lymph node from a 54-year-old man who sought medical care for low-grade fever, anorexia, fatigue, night sweats, weight loss, and persistent cough with bouts of hemoptysis. A chest x-ray had revealed a
right apical infiltrate with beginning cavitation, and examination of the sputum had revealed acid-fast bacilli. This condition is typified by a form of inflammation that invariably includes which of the following?
(A) A morphologically identifiable etiologic agent
(B) Caseous necrosis
(c) Clusters of epithelioid cells
(d) Multinucleated giant cells
(e) Prominent granulation tissue
the answer is c. The clinical description and the figure are both typical of advanced sec- ondary tuberculosis. Although this disorder is now relatively uncommon, its incidence
is increasing, especially in association with immunodeficiency. Tuberculosis is a classic cause of granulomatous inflammation, which is characterized by the presence of “granu- lomas,” which by definition consist of clusters of modified macrophages referred to as epithelioid cells. Additional features such as caseous necrosis, giant cell formation, and identifiable etiologic agents may or may not be present and are not invariable features
of this form of inflammation. Granulation tissue is a feature of early repair and is totally unrelated to granulomatous inflammation.
A laboratory experiment is performed to evaluate the chemotactic potential of a group of potential mediators. Which of the following substances most likely has the greatest affinity for neutrophils? (A) C5a (B) Fucosyl transferase (c) β2-Integrin (d) P-selectin (e) TNF-α
the answer is A. Several substances have chemotactic potential for neutrophils (see Table 2-1). C5a is a prominent example.
A 26-year-old African-American woman has bilateral hilar adenopathy, and radiog- raphy reveals multiple reticular densities in both lung fields. A bronchoscopic biopsy reveals granulomatous inflammation with multiple giant cells of the Langhans type and no evidence of caseous necrosis. Which of the following is the most likely diagnosis?
(A) Aspergillosis
(B) Coccidioidomycosis (c) Histoplasmosis
(d) Sarcoidosis
(e) Tuberculosis
the answer is d. The histologic hallmark of sarcoidosis is the finding of noncaseat-
ing granulomatous inflammation. Although this finding is not entirely specific, a non-necrotizing granulomatous response of the lung is rarely seen in patients with tuberculosis or deep-seated fungal infections. These infections usually have a necrotizing component.
In a laboratory exercise for medical stu- dents, an unknown compound is studied. The students are informed that the com- pound has been isolated from endothelial cells and that its synthesis can be inhibited by aspirin. In the laboratory, the students demonstrate that the compound is a potent vasodilator and platelet antiaggregant. Given these findings, the substance is most likely which of the following mediators? (A) 5-HPETE (B) LTC4 (c) LXA4 (d) PGI2 (e) TxA2
the answer is d. PGI2 is a prostaglandin that is synthesized and expressed primarily
in endothelial cells. It is a product of the cyclooxygenase pathway of arachidonic acid metabolism, which is inhibited by aspirin. PGI2 is a potent vasodilator and platelet anti- aggregant. These properties are often contrasted with those of TxA2, which is primarily synthesized in platelets and is a vasoconstrictor and platelet aggregant. The other com- pounds are products of the lipoxygenase pathway of arachidonic acid metabolism, which is not inhibited by aspirin.
A 70-year-old man presents with the sud- den onset of left-sided weakness, spasticity, and hyperactive and pathologic reflexes. The most serious consequences of this disorder are the result of damage to which of the following cell types? (A) Labile cells (B) Multipotent adult progenitor cells (c) Permanent cells (d) Stable cells
the answer is c. The clinical findings are those of “stroke,” or cerebrovascular disease. This group of entities encompasses injury to the brain caused by disorders of the cerebral vasculature, such as thrombosis, embolism, and hemorrhage (see Chapter 3). The most important consequence is damage to neurons, because neurons are considered to be “permanent” cells, incapable of division and replication (however, this has been recently challenged as the result of provocative stem cell research). Permanent cells are exem- plified by neurons and myocardial cells. Labile cells, such as cells of the epidermis and gastrointestinal mucosa, divide throughout the life of the individual. Stable cells, such
as hepatocytes and renal tubular cells, do not divide regularly but have the capacity to divide and regenerate as needed.
