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A 38-year-old woman presents to her primary care provider after a 3-month trip to China. She complains of chills and a cough for the past 2 weeks. Vital signs are notable for a body temperature of 101°F, and the patient’s weight has decreased by 4 kg since her last visit 3 months ago. A chest radiograph is obtained and shown in Figure A. The patient’s whole blood is incubated with a peptide, and ELISA assay reveals high amounts of IFN-gamma. What is the primary mechanism for the pulmonary tissue destruction evident on the patient’s chest radiograph?
Proteolytic enzymes released by bacteria
Invagination of the lysosomal membrane with uptake of cytoplasmic material
Macrophages ingested with microbes are activated by CD4+ effector T cells
Deposition of immune complexes with resulting inflammatory response
Excessive presence of peroxides and free radicals
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A 78-year-old man presented to his primary physician with a 3-month history of weight loss, fever, fatigue, night sweats, and cough. He is a former smoker. A recent HIV test was negative. A CT scan of the chest reveals a 3 cm lesion in the lower lobe of the left lung and calcification around the left lung hilus. A sputum smear was positive for acid fast organisms. These findings are most consistent with which of the following:
A 44-year-old Caucasian male presents with a fever, recent weight loss, and a cough productive of bloody sputum. A chest X-ray and CT scan were performed, revealing cavities near the apex of his lungs. The patient is started on rifampin, isoniazid, ethambutol and pyrazinamide. Formation of the cavities in the patient's lungs is mainly mediated by:
Toxin secretion by the bacterium
The lung of a 45-year-old Caucasian male who died from Mycobacterium tuberculosis infection reveals the following at autopsy (Image A). Of the steps leading to the formation of this structure, which occurs first?
Activation of macrophages by T-lymphocytes
Th1 cell activation
Bacterium-mediated inhibition of phagosome-lysosome fusion
Formation of epithelioid cells
Formation of giant cells