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53.
During an experiment, drug X is added to a muscle bath containing a strip of guinea pig intestinal smooth muscle. Agonists
are added to the bath, and the resultant effects on muscle tension are shown in the table.
Agonist
Muscle Tension Before Drug X (g)
Muscle Tension After Drug X (g)
Vehicle
6.0
6.1
Acetylcholine
11.3
18.5
Norepinephrine
4.1
4.2
Which of the following types of drugs is most likely to produce effects most similar to those of drug X?
(A) α
1
-Adrenergic antagonist
(B) β-Adrenergic antagonist
(C) Cholinesterase inhibitor
(D) Monoamine oxidase inhibitor
(E) Muscarinic antagonist
54.
A 42-year-old man comes to the physician for a follow-up examination. Four months ago, he underwent repair of a
Dupuytren contracture. Physical examination shows decreased range of motion in the affected hand. The patient is upset that
his hand has not fully healed, and he files a malpractice suit against the physician. Which of the following is the most likely
precipitating factor in this patient's decision to file a malpractice suit?
(A) The patient's perception that the physician is incompetent
(B) The patient's perception that the physician is uncaring
(C) The patient's socioeconomic status
(D) The physician's amount of experience in the medical field
(E) The physician's inability to screen out problem patients
55.
A 72-year-old woman comes to the physician because of a 2-month history of painless swelling of both ankles. She also
reports shortness of breath with exertion and when lying down. She has been awakened from sleep by shortness of breath.
She has not had chest pain. Her pulse is 96/min and regular, respirations are 24/min, and blood pressure is 128/76 mm Hg.
Jugular venous pressure is 15 cm H
2
O. Pulmonary examination shows crackles at both lung bases. Cardiac examination
shows a regular rhythm and a soft S
3
. A grade 3/6 holosystolic murmur is heard best at the apex, radiating to the axilla. There
is 2+ pitting edema of the lower legs and ankles. Which of the following is most likely to confirm the diagnosis?
(A) Measurement of serum troponin I concentration
(B) ECG
(C) Exercise stress test
(D) Echocardiography
(E) Pulmonary artery catheterization
56.
A 14-year-old boy is brought to the physician for a physical examination prior to participating in sports. He appears reluctant
to remove his shirt for the examination, and says that he is embarrassed because he has grown breasts during the past year.
He is at the 50th percentile for height and weight. Physical examination shows bilateral 1.5-cm fibroglandular masses located
beneath the nipple-areolar complex and normal penis and testes. Pubic hair development is Tanner stage 3. Serum
concentrations of gonadotropic hormones, estrogens, and testosterone are within the reference ranges. Which of the following
is the most likely cause of this patient's breast enlargement?
(A) Breast adenocarcinoma
(B) Estradiol-secreting Leydig cell tumor
(C) Peutz-Jeghers syndrome
(D) Seminiferous tubule dysgenesis (Klinefelter syndrome)
(E) Normal development
25
57.
A 5-year-old boy is admitted to the hospital because of a 1-week history of fever and increasingly severe abdominal
discomfort. At the age of 7 months, he was treated for osteomyelitis caused by Aspergillus fumigatus. He has been admitted
to the hospital three times during the past 4 years for severe pneumonia. He appears moderately ill. His temperature is
39°C (102.2°F). Abdominal examination shows an enlarged, tender liver. Ultrasonography of the abdomen shows an
intrahepatic abscess. Culture of the abscess fluid grows Staphylococcus aureus. Further analysis shows failure of the
neutrophils to undergo an oxidative burst when exposed to S. aureus. This patient has an increased susceptibility to infection
as a result of which of the following abnormalities?
(A) Deficient leukocyte production
(B) Failure of leukocytes to migrate between endothelial cells
(C) Failure of leukocytes to roll along the endothelial surface
(D) Inability of leukocytes to ingest microorganisms
(E) Inability of leukocytes to kill intracellular microorganisms
58.
A 22-year-old woman contacts a medical student and asks if he would like to join her for dinner. The student met the woman
when he was assigned to her care during her 2-week hospitalization for treatment of major depressive disorder. He has not
treated or seen the patient since she was discharged from the hospital. He is attracted to this former patient and would be
interested in dating her. Which of the following is the most appropriate action by the medical student regarding this patient's
invitation?
(A) He can date her because he was a medical student, not a physician, when he contributed to her care
(B) He can date her because she is no longer his patient
(C) He can date her, but only after at least 1 year has passed since he treated her
(D) He cannot date her because she was once his psychiatric patient
(E) He cannot date her unless she agrees never to seek care at his hospital in the future
59.
A 73-year-old woman comes to the physician because of a 2-month history of diffuse weakness and tingling of her arms and
legs. Neurologic examination shows weakness of the extensor and flexor muscles of the lower extremities. Knee and ankle
deep tendon reflexes are exaggerated. Sensation to vibration and position is decreased in all extremities, but the decrease is
more prominent in the lower extremities than in the upper extremities. This patient most likely has a deficiency of which of
the following vitamins?
(A) Niacin
(B) Vitamin B
1
(thiamine)
(C) Vitamin B
2
(riboflavin)
(D) Vitamin B
6
(pyridoxine)
(E) Vitamin B
12
(cyanocobalamin)
60.
A 45-year-old man comes to the physician because of right shoulder pain that began after he chopped wood 2 days ago.
Examination of the right upper extremity shows no obvious bone deformities or point tenderness. The pain is reproduced
when the patient is asked to externally rotate the shoulder against resistance; there is no weakness. In addition to the teres
minor, inflammation of which of the following tendons is most likely in this patient?
(A) Infraspinatus
(B) Pectoralis
(C) Subscapularis
(D) Supraspinatus
(E) Trapezius