Transcript
8-2
Test Bank
Kumar: Robbins and Cotran Pathologic Basis of Disease, 9th Edition
Chapter 08: Infections
Test Bank
MULTIPLE CHOICE
1. Which of the following is the most common form of herpesvirus-induced eye infection?
a. Blepharitis
b. Conjunctivitis
c. Iridocyclitis
d. Keratitis
e. Retinitis
ANS: D, Herpesvirus most often causes keratitis, which can be classified as epithelial or interstitial.
2. Mycobacterium tuberculosis phagocytosed by macrophages in granulomas can be killed by endogenous nitric oxide (NO) after these macrophages become activated by T-helper cells. Which biologically active substance stimulates the formation of NO in macrophages?
a. Platelet-activating factor
b. Interferon-g
c. Interleukin-1
d. Tumor necrosis factor
e. Prostaglandin E2
ANS: B, CD4+ T-helper cells secrete interferon-, which stimulates the macrophages to produce nitric oxide (NO), NO2, and HNO3. These bactericidal substances kill the tubercle bacilli in the cytoplasmic vacuoles of the macrophages.
3. Mycobacterium avium intracellulare infection in AIDS patients typically begins in the
a. nasal cavity
b. lungs
c. esophagus
d. small intestine
e. liver
ANS: D, Mycobacterium avium intracellulare infections usually begin in the small intestine, and may disseminate from there to the lymph nodes, spleen, and liver.
4. During a mini-epidemic of Shigella, a 5-year-old child from India became infected and died 3 days after the onset of diarrhea. The most prominent changes seen at autopsy were
a. dilatation of the entire small intestine
b. ulceration of the proximal small intestine
c. ulcerations of the distal ileum
d. multiple ulcerations partially covered with pseudomembranes
e. perforation of the rectum
ANS: D, Ulcerations of the colonic mucosa caused by Shigella are usually covered with pseudomembranes. These findings are not specific but correlate well with the clinical findings, which invariably include massive bloody, pus-containing diarrhea.
5. Diarrhea caused by cholera toxin results from the action of this toxin on cells of the
a. stomach
b. small intestine
c. cecum
d. transverse colon
e. rectum
ANS: B, Cholera toxin acts on the epithelial cells of the small intestine, causing massive secretion of chloride, sodium, and water into the intestinal lumen. The large intestine cannot absorb all that fluid, which is thus discharged in the form of watery diarrhea.
6. Reiter syndrome, including the triad of conjunctivitis, polyarthritis, and genital lesions, occurs in men infected with which pathogen?
a. Neisseria gonorrhoeae
b. Treponema pallidum
c. Chlamydia trachomatis
d. Trichomonas vaginalis
e. Haemophilus ducreyi
ANS: C, Infection with Chlamydia trachomatis is a common cause of sexually acquired urethritis, which sometimes may be associated with eye and joint lesions. This triad is known as Reiter syndrome.
7. Suppurative nail infection (paronychia) and abscesses of fingertips ("felons") are most likely caused by
a. Escherichia coli
b. Pseudomonas aeruginosa
c. Haemophilus influenzae
d. Neisseria gonorrhoeae
e. Staphylococcus aureus
ANS: E, Suppurative infections of fingers are most likely caused by pyogenic Staphylococci.
8. Infection of the uterus following a “criminal abortion” performed in a "back alley" is most likely caused by
a. anaerobic non–spore-forming bacteria
b. spore-forming anaerobes
c. pyogenic cocci
d. coliform bacteria
e. Neisseria gonorrhoeae
ANS: A, Anaerobic non–spore-forming bacteria are the most common commensals in the lower female genital tract, and are thus the most common cause of uterine infection in septic “criminal abortions.”
9. A 60-year-old man known to have diabetes mellitus was admitted to the hospital in ketoacidosis. He had a massive, invasive infection of the nasal sinuses. Biopsy disclosed fungal infection, which was most likely caused by
a. Candida albicans
b. Aspergillus fumigatus
c. Mucor
d. Histoplasma capsulatum
e. Pneumocystis carinii
ANS: C, Mucormycosis is an opportunistic infection of the upper and lower respiratory tract and is most often found in immunosuppressed persons and in diabetics.
10. Which of the following is a preventable cause of blindness in Africa?
a. Giardiasis
b. Onchocerciasis
c. Filariasis
d. Cryptosporidiosis
e. Schistosomiasis
ANS: B, Onchocerciases is a preventable cause of blindness in Africa.
11. Which African disease is complicated by elephantiasis of the legs?
a. Giardiasis
b. Onchocerciasis
c. Filariasis
d. Cryptosporidiosis
e. Schistosomiasis
ANS: C, Filariasis, an infection caused by Wuchereria bancrofti, may obstruct lymphatics and cause elephantiasis.
12. Lepromatous leprosy represents a form of disease that develops due to
a. accelerated T-helper lymphocyte response
b. accelerated cytotoxic T-cell response
c. inadequate B-cell response
d. hyperimmunity
e. immunologic anergy
ANS: E, Leprosy occurs in two forms: tuberculoid leprosy, characterized by a granulomatous T-lymphocyte response, and lepromatous leprosy, which occurs in anergic persons who cannot mount a T-cell response.
13. The diagnosis of malaria is best made by examining a
a. biopsy specimen of the liver
b. biopsy specimen of the spleen
c. bone marrow biopsy
d. blood smear
e. serum sample for antibodies to plasmodia
ANS: D, Plasmodia are parasites that infect red blood cells and can be best seen in peripheral blood smears.
14. Schistosoma mansoni infection causes liver changes that present histologically as
a. granulomas that also contain eosinophils
b. abscesses
c. suppurative cholangitis
d. centrolobular necrosis of liver cells
e. centrolobular fibrosis
ANS: A, Schistosoma mansoni and S. japonicum lay eggs in the liver and elicit a granulomatous reaction. In addition to lymphocytes and macrophages, these granulomas contain scattered eosinophils, which may also occur in other parasitic infections.
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