A Guatemalan child with a history of meconium ileus is brought to a clinic because of a chronic cough. The mother notes a history of respiratory tract infections and bulky, foul-smelling stools. After assessment of the respiratory tract illness, the physician should also look for signs of
A 1-week-old, bottle-fed, low-birth-weight neonate develops severe abdominal pain with bloody diarrhea. Several hours later, the neonate undergoes emergency surgery. A portion of small intestine is resected , and pathologic examination demonstrates a perforation. Which of the following would most likely be seen on microscopic examination of the involved bowel?
A 68-year-old man presents to his physician with complaints of fatigue and a dragging sensation in his abdomen. Physical examination is remarkable for massive splenomegaly without lymphadenopathy. The patient's hematocrit is 30%, his platelet count is 80,000/mm3, and his leukocyte count is 2500/mm3. Bone marrow biopsy shows 'fried egg' cells expressing the pan B-cell markers CD19 and CD20, and the monocyte marker CD11c. Positive staining for which of the following substances would most likely verify the likely diagnosis?
A 22-year-old male military recruit complains of a headache and stiff neck. He is examined, blood is drawn, and a lumbar puncture performed. The glucose in the CSF is 100 mg/dL and the serum glucose is 120 mg/dL. The CSF shows 3 lymphocytes and 0 neutrophils/microliter. Which of the following conclusions concerning the interpretation of these findings is most accurate?
A newborn baby has a prominent defect at the base of his spine through which his meninges and spinal cord protrude. A failure of which of the following processes is the most common cause of this type of defect?
Which of the following is thought to be a major contributor to the cachexia often experienced by patients with advanced cancer?
A patient, who appears to be female, is found to be 46,XY. The patient's vagina is very shallow, ending in a blind pouch, and there are palpable masses in the labia. The diagnosis of testicular feminization syndrome is made. Which of the following was most likely present during the early fetal life of this individual?
A patient develops a swollen and tender lymph node in his popliteal fossa. An infected skin lesion in which of the following sites would most likely induce lymphadenopathy in this region?
A 37-year-old female presents to the emergency room with a fever. Chest x-ray shows multiple patchy infiltrates in both lungs. Echocardiography and blood cultures suggest a diagnosis of acute bacterial endocarditis limited to the tricuspid valve. Which of the following is the most probable etiology?
During an intra-abdominal operation, a surgeon asks a medical student to pass his hand toward the head, along the inner aspect of the anterior abdominal wall, slightly to the right of the midline. The reflection of which of the following will eventually stop the movement of the student's hand?