A 9-year-old boy presents to the emergency department with a 12-hour history of severe vomiting and increased sleepiness. He experienced high fever and muscle pain about 5 days prior to presentation, and his parents gave him aspirin to control the fever at that time. On presentation, he is found to be afebrile though he is still somnolent and difficult to arouse. Physical exam reveals hepatomegaly and laboratory testing shows the following results: Alanine aminotransferase: 85 U/L Aspartate aminotransferase: 78 U/L Which of the following is the most likely cause of this patient's neurologic changes?
ASubarachnoid hemorrhage
BViral meningitis
CReye syndrome
DCerebral edema
EBacterial sepsis
An investigator is studying severely ill patients who experience hypoglycemia and ketonuria during times of fasting. The investigator determines that during these episodes, amino acids liberated from muscle proteins are metabolized to serve as substrates for gluconeogenesis. Nitrogen from this process is transported to the liver primarily in the form of which of the following molecules?
AGlutamate
Bα-ketoglutarate
CAlanine
DArginine
EPyruvate
A 4-day-old male newborn delivered at 39 weeks' gestation is evaluated because of poor feeding, recurrent vomiting, and lethargy. Physical examination shows tachypnea with subcostal retractions. An enzyme assay performed on a liver biopsy specimen shows decreased activity of carbamoyl phosphate synthetase I. This enzyme plays an important role in the breakdown and excretion of amino groups that result from protein digestion. Which of the following is an immediate substrate for the synthesis of the molecule needed for the excretion of amino groups?
AN-acetylglutamate
BHomocysteine
CPhenylalanine
DValine
EAspartate
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