13
19.
A 26-year-old woman is brought to the emergency department 3 hours after ingesting approximately 50 tablets of aspirin in a
suicide attempt. She is nauseated, confused, and sleepy. Her pulse is 130/min, respirations are 30/min, and blood pressure is
100/60 mm Hg. Which of the following sets of laboratory values is most likely on evaluation of blood obtained before
treatment?
Serum
Arterial Blood
HCO
3
−
pH
P
CO
2
(A)
↑
↓
↑
(B)
↓
↓
↓
(C)
↑
↑
↓
(D)
↓
↓
↑
(E)
↑
↑
↑
20.
An investigator is studying the incidence of the common cold among medical students at various time points during the
school year. Results show an increased incidence of upper respiratory tract infections among these students during finals
week. It is hypothesized that the stress of studying for examinations adversely affects the immune system, making the
students more susceptible to infection. Which of the following laboratory findings in these students during examination week
is most likely to support this hypothesis?
(A) Decreased
AM
serum cortisol concentration
(B) Decreased macrophage activity
(C) Increased basophil count
(D) Increased lymphocyte count
(E) Increased natural killer cell activity
21.
A 63-year-old man is brought to the emergency department because of a 4-day history of increasingly severe left leg pain and
swelling of his left calf. He also has a 1-month history of increasingly severe upper midthoracic back pain. During this time,
he has had a 9-kg (20-lb) weight loss despite no change in appetite. He has no history of major medical illness. His only
medication is ibuprofen. He is 180 cm (5 ft 11 in) tall and weighs 82 kg (180 lb); BMI is 25 kg/m
2
. His vital signs are within
normal limits. On examination, lower extremity pulses are palpable bilaterally. The remainder of the physical examination
shows no abnormalities. An x-ray of the thoracic spine shows no abnormalities. A CT scan of the abdomen shows a 3-cm
mass in the body of the pancreas; there are liver metastases and encasement of the superior mesenteric artery.
Ultrasonography of the left lower extremity shows a femoropopliteal venous clot. Which of the following is the most likely
cause of this patient’s symptoms?
(A) Carcinoid syndrome
(B) Hypercoagulability from advanced malignancy
(C) Multiple endocrine neoplasia
(D) Splenic artery aneurysm and embolic disease of the left lower extremity
(E) Superior mesenteric artery syndrome
22.
A 35-year-old man comes to the physician because of pain and swelling of his right arm where he scraped it on a tree branch
2 days ago. His temperature is 38.3°C (101°F). Examination of the right forearm shows edema around a fluctuant
erythematous lesion at the site of trauma. The area is extremely tender to palpation. Which of the following is most likely the
primary mechanism of the development of edema in this patient?
(A) Degranulation of eosinophils
(B) Disruption of vascular basement membranes
(C) Increased hydrostatic pressure
(D) Release of thromboxane
(E) Separation of endothelial junctions
14
23.
A 4-year-old boy from Brazil is brought to the physician because of a 1-week history of painless swelling of his jaw and
pressure around his eyes. He is at the 80th percentile for height and weight. Physical examination shows a single 12 × 10-cm
lesion in the right side of the jaw with diffuse limits and irregular edges. Photomicrographs of an incisional biopsy specimen
of the lesion are shown. Based on these findings, which of the following processes is most likely occurring in the region
indicated by the arrows?
(A) Apoptosis
(B) Necrosis
(C) Oncosis
(D) Ostosis
(E) Symptosis
24.
A 33-year-old woman comes to the physician because of a 2-day history of mild nausea, increased urinary urgency and
frequency, and constipation. She also has had a 4.5-kg (10-lb) weight loss during the past 2 weeks and a 3-week history of
vaginal bleeding. Pelvic examination shows a nodular cervix with an irregular, friable posterior lip, and a rock-hard,
irregular, immobile pelvic mass that extends across the pelvis. Examination of biopsy specimens from the cervix and anterior
wall of the vagina show well-differentiated keratinizing squamous cell carcinoma. Which of the following best describes the
pathogenesis of this patient's disease?
(A) Inactivation of cellular p53
(B) Insertion of viral promotors adjacent to cellular growth factor genes
(C) Specialized transduction
(D) Transactivation of cellular growth factor genes by TAX
(E) Translocation of CMYC to an Ig gene promoter
25.
A 27-year-old man is admitted to the hospital 45 minutes after being involved in a motor vehicle collision. Physical
examination shows a sluggish response to stimuli. Neurologic examination shows no other abnormalities. A skull x-ray
shows a linear, nondepressed basal skull fracture. Two weeks later, the patient develops polyuria and polydipsia. Laboratory
studies show a serum glucose concentration within the reference range, increased serum osmolality, and decreased urine
osmolality. Following the administration of desmopressin, urine osmolality increases. The beneficial effect of this drug is
most likely due to activation of which of the following?
(A) Adenylyl cyclase
(B) Ca
2+
channels
(C) Janus kinase
(D) Serine kinase
(E) Tyrosine kinase