USMLE QBANK

Digoxin toxicity may be precipitated by hypercalcemia?

A 2-month-old boy is evaluated for failure to thrive. As the pediatrician is examining the patient, she witnesses a seizure. Physical examination is remarkable for hepatomegaly, a finding later confirmed by CT scan, which also reveals renomegaly. Serum chemistries demonstrate severe hypoglycemia, hyperlipidemia, lactic acidosis, and ketosis. Which of the following diseases best accounts for this presentation?

An alert pediatric intern notices that a neonate with dysmorphic facies is twitching abnormally. As he watches, the baby experiences a seizure. Stat laboratories indicate a glucose of 90, serum sodium of 140, serum potassium of 4.2 and serum calcium of 3.9. Over the next several months, the child is admitted to the hospital twice for Candida infections, and once for a viral exanthem. Which of the following is the most likely diagnosis?

Which of the following metabolic processes occurs exclusively in the mitochondria?

A 21-year-old college student from Connecticut with a past history of Lyme disease presents with chronic pain and swelling in his right knee. He states that he has had problems with the knee for the past two years. Which of the following HLA alleles would you expect to be present in this individual?

A person lifts one foot prior to taking a step. Which of the following nerves innervates the muscle group that allows the person to maintain balance by holding the weight of his body over the foot remaining on the ground?

Evaluation of an infant with a variety of congenital abnormalities reveals hypocalcemia due to a lack of parathyroid hormone. On x-ray, the thymic shadow is absent. A failure of development and differentiation of which of the following embryonic structures would most likely be responsible for the observed presentation?

The table below shows the fall in blood pressure that occurs for the various types of blood vessels as blood flows from the aorta (100 mm Hg) to the right atrium (0 mm Hg). Which of the following types of blood vessel is likely to have the highest ratio of wall cross-sectional area to lumen cross-sectional area

A patient complaining of chest pain with exercise is evaluated by cardiac catheterization. The left anterior descending (LAD) branch of the coronary artery is visualized but the contrast angiography is poor. A Doppler-tipped catheter is inserted and the blood velocity is observed to increase transiently from 10 cm/sec to 70 cm/sec and then decrease back to 10 cm/sec as the probe passes a particular location in the artery. What was the cause of these changes in velocity measurements?

A 25-year-old male gets into a brawl outside a bar. During the altercation, someone pulls out a gun and shoots him in the head. The bullet enters the man's temple and severs his right optic nerve completely. He is quickly transported to a nearby emergency room and an emergency physician tests his pupillary response by shining a light in the right eye. What will the physician most likely find?