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 ragweed 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)
E Immunoglobulin G
(D) CORRECT. Histamine, mainly released from mast cells in perivascular locations, leads to vasodilation and fluid exudation. That is why people with allergies take antihistamines.
A 45-year-old man has been working hard all day long carrying loads of bricks to build a wall. He is most likely to use a non-steroidal anti-inflammatory drug such as ibuprofen in order to try and diminish which of the following processes in his arms?
C Liquefactive necrosis
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.
[HIDE](E) CORRECT. This is systemic anaphylaxis, a type I hypersensitivity reaction in which the antigen contacts preformed antibody attached to mast cells, leading to mast cell degranulation and production of symptoms, typically within minutes.[/HIDE]
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?
B Complement C5a
C Nitric oxide
D Tumor necrosis factor
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 several 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 6 cm left hilar mass
B Bilateral interstitial infiltrates
C Marked hilar lymphadenopathy
D Left upper lobe consolidation
E Extensive pleural thickening with pleural effusions
[HIDE](B) CORRECT. Viral illnesses, including those caused by common viral respiratory pathogens such as influenza, produce chronic inflammation that is interstitial in the lungs. The lack of an alveolar filling process results in the lack of a productive cough.[/HIDE]
In an experiment, Enterobacter cloacae organisms are added to a solution containing leukocytes. Engulfment and phagocytosis of the microbes is observed to occur. Next a substance is added which enhances engulfment.
Which of the following substances is most likely to produce this effect?
A Complement C3b
B Glutathione peroxidase
C Immunoglobulin M
E NADPH oxidase
[HIDE](A) CORRECT. The C3b fragment serves as an effective opsonin.[/HIDE]
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 conditions is this woman most likely to have?
A Staphylococcus aureus septicemia
B Ingestion of chili peppers
C Diabetes mellitus
E Infection with Helicobacter pylori
[HIDE](E) CORRECT. This is a chronic inflammatory process, based upon the inflammatory cell components.[/HIDE]
[HIDE](C) CORRECT. Antigen presenting cells such as dendritic cells and macrophages which have trapped antigen 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. [/HIDE]
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
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
D Fibroblast growth factor
E Epidermal growth factor
(D) CORRECT. FGF can stimulate all aspects of angiogenesis.[/HIDE]
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 The presence of fibrin
E Large size of the effusion
[HIDE](C) CORRECT. A transudate has few cells or protein and has a clear appearance.[/HIDE]
[HIDE](C) CORRECT. Cell surface growth factor receptors recruit intracellular protein kinases that begin a sequence of events leading to cell division and growth.[/HIDE]
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?
C Tyrosine kinase
D Hyaluronic acid