USMLE USMLE Certifications USMLE Questions & Answers

• Question 501:

  A 72-year-old woman who has smoked 20 cigarettes daily for the past 38 years begins using eye drops for glaucoma. Three days later, she has a marked increase in shortness of breath while walking up a flight of stairs. Which of the following drugs is the most likely cause of the development of shortness of breath in this patient?

  A. Acetazolamide

  B. Apraclonidine

  C. Epinephrine

  D. Latanoprost

  E. Timolol

  Correct Answer: E

• Question 502:

  Six healthy subjects participate in a study of muscle metabolism during which hyperglycemia and hyperinsulinemia is induced. Muscle biopsy specimens obtained from the subjects during the resting state show significantly increased concentrations of malonyl-CoA. The increased malonyl-CoA concentration most likely directly inhibits which of the following processes in these subjects?

  A. Fatty acid oxidation

  B. Fatty acid synthesis

  C. Gluconeogenesis

  D. Glycogenolysis

  E. Glycolysis

  F. Oxidative phosphorylation

  Correct Answer: A

• Question 503:

  A 62-year-old man comes to the physician for a follow-up examination after he was diagnosed with chronic inflammatory interstitial pneumonitis. Following pulmonary function testing, a biopsy specimen of the affected area of the lungs is obtained. Compared with a healthy man, analysis of this patient's biopsy specimen is most likely to show which of the following patterns of changes in the cell populations of alveoli?

  

  A. Option A

  B. Option B

  C. Option C

  D. Option D

  E. Option E

  F. Option F

  G. Option G

  H. Option H

  Correct Answer: E

• Question 504:

  A 56-year-old man comes to the emergency department because of a 4-day history of colicky right flank pain that radiates to the groin and hematuria. Ultrasound examination of the kidneys shows right-sided hydronephrosis and a dilated ureter. Which of the following is most likely to be found on urinalysis?

  A. Erythrocyte casts

  B. Glucose

  C. Leukocyte casts

  D. Oval fat bodies

  E. Uric acid crystals

  Correct Answer: E

• Question 505:

  

  A 36-year-old man with profound intellectual disability is brought to the physician by staff at his facility because of increasing abdominal girth during the past 2 weeks. He is unable to speak, and no medical history is currently available. Physical examination shows a protuberant abdomen with a fluid wave and shifting dullness. There are no signs of trauma to the area. Laboratory studies show no abnormalities. A CT scan of the abdomen is shown. Fluid is present in which of the following areas as indicated by the arrow?

  A. Epiploic foramen

  B. Gastrosplenic ligament

  C. Hepatorenal pouch (of Morison)

  D. Omental bursa (lesser sac)

  E. Sulcus pericolicus

  Correct Answer: D

• Question 506:

  A study is designed to evaluate the feasibility of acupuncture in children with chronic headaches. Sixty children with chronic headaches are recruited for the study. In addition to their usual therapy, all children are treated with acupuncture three times a week for 2 months. Which of the following best describes this study design?

  A. Case-control

  B. Case series

  C. Cross-sectional

  D. Cross-sectional

  E. Historical cohort

  F. Randomized clinical trial

  Correct Answer: B

• Question 507:

  

  A 47-year-old woman comes to the emergency department because of a 2-week history of intermittent abdominal pain, nausea, and vomiting. She has had similar episodes sporadically during the past 4 years. Physical examination shows dehydration, jaundice, and upper abdominal distention. Laboratory studies show hyperbilirubinemia. A CT scan and upper gastrointestinal series of the abdomen with oral contrast are shown; the arrows indicate the abnormality. Which of the following is the most likely cause of these findings?

  A. Annular pancreas

  B. Cirrhosis of the liver

  C. Duodenal constriction by the portal vein

  D. Duodenal constriction by the superior mesenteric artery

  E. Pyloric stenosis

  Correct Answer: A

• Question 508:

  An 8-year-old boy is brought to the office by his mother because of a 3-day history of fever, sore throat, and itchy eyes. He just returned from a weeklong summer camp that included hiking trips and swimming lessons in the camp-owned swimming pool. He has no history of major medical illness and receives no medications. He appears tired. His temperature is 39.4°C (102.9°F); other vital signs are within normal limits. Physical examination shows conjunctival injection and discharge and oropharyngeal erythema. The public health department reports an outbreak of similar symptoms among the other campers and camp volunteers. Which of the following is the most likely cause of this patient's symptoms?

  A. Adenovirus

  B. Cytomegalovirus

  C. Epstein-Barr virus

  D. Influenza virus

  E. West Nile virus

  Correct Answer: A

• Question 509:

  A 12-year-old girl is brought to the physician because of a 2-month history of intermittent yellowing of the eyes and skin. Physical examination shows no abnormalities except for jaundice. Her serum total bilirubin concentration is 3 mg/dL, with a direct component of 1 mg/dL. Serum studies show a haptoglobin concentration and AST and ALT activities that are within the reference ranges. There is no evidence of injury or exposure to toxins. Which of the following additional findings is most likely in this patient?

  A. Decreased activity of UDP glucuronosyltransferase

  B. Gallstones

  C. Increased hemolysis

  D. Increased serum alkaline phosphatase activity

  E. Ineffective erythropoiesis

  Correct Answer: A

• Question 510:

  A 10-year-old girl is brought to the office by her mother because her school nurse thinks that she may have Marfan syndrome. She is at the 95th percentile for height and 25th percentile for weight. Physical examination shows a narrow palate with dental crowding, long slender extremities, and joint laxity. Molecular testing for FBN1 shows a single nucleotide difference that does not change the amino acid at that locus. Her mother is 163 cm (5 ft 4 in) tall. There is no clinical evidence of Marfan syndrome in the mother, but she has the same single nucleotide change as the patient. The same nucleotide change is found in 15 of 200 individuals without Marfan syndrome. Which of the following best describes the single nucleotide change in the patient and her mother?

  A. It is a disease-causing mutation in the patient and her mother

  B. It is a polymorphism

  C. It is a sequence variant of unknown significance

  D. It will change the folding of the protein E. It will result in a truncated protein

  Correct Answer: B