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USMLE QBANK

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1. An increase in which of the following best explains the mechanism by which the cardiac output increases in severe anemia?
A.
B.
C.
D.
E.

2. A 2-year-old retarded child is evaluated by a metabolic specialist. The child's history is significant for failure to thrive and progressive neurologic deterioration, including deafness and blindness. Physical examination is remarkable for hepatosplenomegaly , as well as a cherry-red spot on funduscopic examination. These symptoms are consistent with a diagnosis of
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B.
C.
D.
E.

3. An 8-month-old female child is brought to medical attention because her first four teeth show several discrete, discolored, circumferential bands that show very little enamel. Excessive levels of which of the following may have produced this defect?
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B.
C.
D.
E.

4. Which of the following complications is currently the major limitation to the long-term success of cardiac transplantation?
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D.
E.

5. A child develops a tumor of the cerebellum. Biopsy reveals evidence of both neuronal and glial differentiation. Which of the following is the most likely diagnosis?
A.
B.
C.
D.
E.

6. A 56-year-old man visits his physician with complaints of complete exhaustion after mowing the lawn in his small front yard. He also complains of dizziness, irritability, difficulty sleeping, and loss of libido. On physical examination, the man's skin, conjunctiva, and oral mucosa are pale. A blood test indicates the man's hemoglobin is 7 g/dL. Which of the following findings is also likely to be present in this man?
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E.

7. A 55-year-old man had been in good health since receiving a heart transplant for severe atherosclerotic disease. Five years after transplantation, the patient died suddenly, without any premonitory symptoms, while working in his garden. He had been maintained on cyclosporin since his transplant. Which of the following complications would most likely be found at autopsy in the transplanted heart?
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B.
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E.

8. An elderly lady is brought to the emergency room after drinking insecticide that she thought was tea. After her stomach is pumped, her sense of smell is tested and it is found that she can not distinguish common smells (e.g., an orange, coffee). CT scan of the head demonstrates a mass in the olfactory groove area. The axons likely compressed by this mass project to which of the following structures?
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E.

9. A 27-year-old man develops bilateral parotid gland swelling and orchitis, and is generally ill with fever of 102° F. Which of the following substances is most likely to be significantly elevated in the patient's serum?
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B.
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E.

10. A 55-year-old man presents to the emergency room with crushing substernal pain and left shoulder pain of 2 hours duration. The pain is not relieved by sublingual nitroglycerin, and the electrocardiogram shows ST elevation in several leads. Aspirin and streptokinase therapy are initiated, and the patient is admitted to the intensive care unit. The next morning, serum cardiac enzymes are elevated to 4 times the upper limit of normal, and the electrocardiographic changes are still present. Which of the following is the most likely diagnosis?
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B.
C.
D.
E.

11. Which of the following amino acids is post-translationally hydroxylated in the cytoplasm of fibroblasts?
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B.
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D.
E.

12. Microscopic examination of a cancer cell reveals a cell in an abnormal telophase in which three clusters of chromosomes are seen. An abnormality of which of the following would be most likely to produce this alteration?
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B.
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D.
E.

13. A 58-year-old man with fainting spells and exercise intolerance is found to have a bicuspid aortic valve with marked aortic stenosis. Which of the following physical findings would be prominent in this patient?
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D.
E.

14. A 48-year-old man complaining of chest pain is brought to the emergency room. Physical examination followed by echocardiography demonstrates aortic stenosis. His coronary blood flow is increased. Which of the following is the most likely explanation for the increased coronary blood flow in this individual?
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B.
C.
D.
E.

15. A 45-year-old man presents to the emergency department with severe headache and vomiting. A CT scan shows a well-circumscribed cystic lesion within the 3rd ventricle; there is no calcium deposition. The cyst is surgically removed. On histologic examination, the wall of the cyst consists of a single layer of mucin-producing columnar epithelium with a ciliated apical surface. Which of the following is the most likely diagnosis?
A.
B.
C.
D.
E.

16. A 36-year-old female is brought to the emergency room by her husband who says that she "complained of a severe headache then lost consciousness." She has a history of hypertension and had been on several different medications. The examining physician notes that she is unable to move her arms and legs, but can blink her eyes. When the physician asks her to blink twice if she can hear him, she promptly does so. In which of the following structures is this woman's lesion most likely located?
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B.
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D.
E.

17. A 71-year-old man has been in excellent health, and practicing competently as an attorney. He is brought to the emergency room following a motor vehicle accident. A workup, including imaging of the spine, thorax, and head, is negative, but the patient is admitted for overnight observation. His injuries include several lacerations to the face and extremities as well as several contusions to the thorax. Three weeks later, he is admitted to the hospital for confusion. A neurologic exam is normal except that he is not oriented to time or place, and can recall only 1 out of 6 objects after 3 minutes. Which of the following is the most likely diagnosis?
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B.
C.
D.
E.

18. An 80-year-old woman dies after a long history of progressive memory loss, apraxia, and recurrent episodes of confusion. In the last months of life she was bedridden and unable to recognize familiar faces and objects. The pathologist identifies numerous flame-shaped intracytoplasmic inclusions in neurons of the neocortex and hippocampus. These consist of paired helical filaments (PHFs) on electron microscopy. Which of the following biochemical changes most likely accounts for the development of PHFs in this condition?
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B.
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D.
E.

19. The activity of which of the following enzymes is directly affected by citrate?
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20. Which of the following structures is found only in Gram-negative microorganisms?
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21. A scientist wishes to study free radical production under ischemic conditions. He decides to produce cerebral ischemia by tying off an artery of the brain. Ligation of which of the following arteries would be most likely to produce significant ischemic damage?
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B.
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E.

22. A 52-year-old woman has long-standing rheumatoid arthritis (RA) and is being treated with corticosteroids and nonsteroidal anti-inflammatory drugs (NSAIDs). Which of the following cardiac complications may arise in this clinical setting?
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D.
E.

23. Most fascia of the body that attach to bones attach by which of the following mechanisms?
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E.

24. A 35-year-old woman notices a change in the appearance of a mole on her neck. Physical examination reveals that the lesion is an irregular, nodular, superficial mass with a variegated appearance. Biopsy demonstrates a primary malignant tumor. Which of the following factors is most predictive of the patient's long term prognosis?
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B.
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D.
E.

25. A 43-year-old, insulin-dependent diabetic patient is diagnosed with hypertension and begins therapy with an antihypertensive agent. Three days later, he measures his blood glucose at home and finds that it is 53 mg/dL. He recalibrates his glucose testing apparatus and repeats the test, only to find that the first reading was accurate. He is concerned that his hypoglycemia did not produce the normal premonitory signs and symptoms. Which of the following medications was most likely prescribed to treat his hypertension?
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B.
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E.