C O M P R E H E N SIO N Q U E ST IO N S
[33.1] A 18-year-old male with sickle cell anemia develops severe right
upper-abdominal pain radiating to his lower right chest and his right
flank 36 hours prior to admission to the ER. Twelve hours following
the onset of pain, he began to vomit intractably. In the past year he has
had several episodes of mild back and lower extremity pain that he
attributed to mild sickle cell crises. He reported that the present pain
was not like his usual crisis pain. He also reports that his urine is the
color of iced tea and his stool now has a light clay color. On examina-
tion, his temperature is slightly elevated, and heart rate is rapid. He is
exquisitely tender to pressure over his right upper abdomen. The scle-
rae of his eyes are slightly yellowish in color.
What is the most likely cause of this patient’s symptoms?
A. A cholesterol-rich gallstone
B. A defect in the synthesis of bile acids
C. A defect in heme synthesis
D. A gallstone rich in calcium bilirubinate
E. A sickle cell crisis brought on by overexertion
[33.2] A patient has been on combination statin and cholestyramine therapy
to lower his serum cholesterol levels. Prior to any surgery, this patient
would be well advised to be supplemented with which of the following?
A. Vitamin A
B. Vitamin B12
C. Vitamin C
D. Vitamin K
E. Linolenic acid
[33.3] A 17-year-old female, whose parents were first cousins, presents to a
neurologist because of recurring seizures despite being on anticonvul-
sive therapy. Nodules that appeared to be fatty deposits were present on
her Achilles tendon and several of her joints. Plasma cholesterol con-
centrations were elevated, and an assay of plasma sterols indicated ele-
vated cholestanol. Cultured skin fibroblasts did not contain any sterol
27-hydroxylase activity. A diagnosis of cerebrotendinous xanthomato-
sis, a genetic disease inherited in an autosomal fashion, was made.
A deficiency in sterol 27-hydroxylase would lead to a decrease in the
synthesis of which of the following compounds?