A 56-year-old man presents to his internist with jaun- dice. The patient is receiving no medication, and his only symptomatic complaint is mild fatigue over the past 2 months. Physical examination is remarkable only for the presence of scleral icterus. The patient has no significant past medical history. Analysis of serum chemistry reveals the following: 



SGOT: 0.58 ’kat/L (35 U/L)

SGPT: 0.58 ’kat/L (35 U/L)

Total bilirubin: 91.7 ’mol/L (7 mg/dL) 

Direct bilirubin: 85.5 ’mol/L (5 mg/dL) 

Alkaline phosphatase: 12 ’kat/L (720 U/L)



Which of the following is the next most appropriate diagnostic step? 

A 24-year-old patient known to be infected with HIV- 1 presents with a 2-week history of intermittent bloody diarrhea, urgency, abdominal pain, and malaise. Stool cul- ture for enteropathogenic organisms is negative, and anal- ysis for ova and parasites is similarly unrevealing. The patient is taking no medication. The diarrheal symptoms do not respond to a course of trimethoprim-sulfameth- oxazole. Colonoscopic examination reveals multiple areas of ulceration and mucosal erosion. Biopsy reveals the presence of cells containing a large, densely staining nu- cleus and abundant intracytoplasmic inclusions. The most appropriate therapy for this patient is 

A 48-year-old woman develops fevers, chills, and ic- teric sclera. In addition to a fever of 39.2 C (102.5 F), the physical examination is remarkable for an ill-appearing jaundiced female with right upper quadrant pain. Ultra- sonography reveals a dilated common bile duct with stones in the gallbladder and in the duct itself. The patient is placed on broad-spectrum antibiotics to cover organisms known to infect the biliary tract. The procedure most appropriate now is 

A 45-year-old man says that for the past year he oc- casionally has regurgitated food particles eaten several days earlier. His wife complains that his breath has been foul-smelling. He has had occasional dysphagia for solid foods. The most likely diagnosis is