[usmlelover]

1>Which of the following conditions may lead to development of an exudate within the pleural cavity?
A. Bacterial pleuritis
B. Cirrhosis of the liver
C. Congestive heart failure
D. Nephrotic syndrome
E. Protein-losing enteropathy
Answer
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2>In which of the following sites do myxopapillary ependymomas most frequently occur?
A. Cerebellum
B. Conus medullaris
C. 4th ventricle
D. Lateral ventricles
E. Midbrain
Answer
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3>A patient has long-standing severe hemolytic anemia characterized by hypochromic cells. Electrophoresis studies demonstrate a near complete absence of beta chains. Several years later, the patient develops cardiac failure. Intracardiac deposition of which of the following would be most likely to contribute to the cardiac failure?
A. Calcium
B. Iron
C. Magnesium
D. Potassium
E. Sodium
Answer
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4>Before being approved by the FDA, a chemical is tested for carcinogenicity by examining its mutagenic effects on bacterial cells in culture. Which of the following tests is used to make this determination?
A. Ames test
B. Nitroblue tetrazolium test
C. Watson-Schwartz test
D. Widal test
E. Woellner enzyme test
Answer
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5.A sharp instrument passing through the superior orbital fissure would most likely sever the
A. abducens nerve
B. facial nerve
C. mandibular nerve
D. maxillary nerve
E. middle meningeal artery
F. ophthalmic artery
G. optic nerve
Answer
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6>An elderly nursing home patient has had multiple small strokes. On several occasions she has aspirated food, and neurological examination reveals that her gag reflex is absent. These findings suggest involvement of the nucleus of which of the following cranial nerves?
A. Facial (VII)
B. Glossopharyngeal (IX)
C. Hypoglossal (XII)
D. Spinal accessory (XI)
E. Vestibulocochlear (VIII)
Answer
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7>A new antifungal medication is being tested in Phase I clinical trials. Examination of the pharmacokinetic properties of the drug reveals that the half-life of the drug is 6 hours. If a continuous intravenous infusion of this drug were started on a research subject, how long would it take to reach 75% of steady state?
A. 3 hours
B. 6 hours
C. 9 hours
D. 12 hours
E. 18 hours
F. 24 hours
Answer
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8>A leukemia patient who has undergone multiple courses of chemotherapy develops herpes simplex encephalitis. Which of the following would you expect a CT scan of the patient's brain to show?
A. Generalized volume loss
B. Volume loss selectively in the basal ganglia
C. Volume loss selectively in the brainstem
D. Volume loss selectively in the cerebellum
E. Volume loss selectively in the temporal and frontal lobes
Answer
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9>An 18-year-old male takes an employment physical examination that is remarkable for a systolic murmur preceded by a distinct click on auscultation. The patient has unique body features, with unusually long legs and long, tapering fingers. An ocular examination reveals dislocation of the lens. An abnormality of which of the following gene products is thought to underlie this condition?
A. Collagen
B. Dystrophin
C. Elastin
D. Fibrillin
E. Myosin b-chain
Answer
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10>A third-world patient develops muscle weakness and atrophy with fasciculations and hyporeflexia. The patient's condition continues to deteriorate, and his legs are eventually permanently paralyzed. The virus that can cause these problems is usually spread by which of the following routes?
A. Dirt contact with open wound
B. Injection
C. Mosquitoes
D. Oral-fecal
E. Puncture wound of the foot
Answer
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11>Physical examination of a 45-year-old diabetic patient demonstrates a pulsatile abdominal mass. Radiographic studies demonstrate a 10 cm diameter aneurysm of the abdominal aorta with foci of calcification in the walls. Which of the following is the most likely etiology for this aneurysm?
A. Atherosclerosis
B. Congenital weakness
C. Cystic medial necrosis
D. Syphilis
E. Vasculitis
Answer
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12>A 40-year-old woman is being seen by a physician for the 10th time this year for evaluation of vague aches and pains. An extensive prior evaluation has excluded the possibility of serious disease. During the interview with this patient, she makes repeated statements along the lines of, "What I want doesn't matter. Do what you want." And, "I'm afraid you won't have time to see me anymore." The traits this patient is exhibiting are most consistent with which of the following personality disorders?
A. Dependent
B. Histrionic
C. Obsessive-compulsive
D. Paranoid
E. Schizoid
Answer
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13>A 60-year-old man suddenly becomes completely blind in one eye, and angiography demonstrates occlusion of the central retinal artery. Which of the following is the most likely cause of the occlusion?
A. Atheroma or embolism
B. Cranial (temporal) arteritis
C. Hypertension
D. Polycythemia vera
E. Tumor
Answer
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14 A mailman gets a severe bite wound from a pit bull guarding a junkyard. The wound is cleansed and he receives a booster injection of tetanus toxoid and an injection of penicillin G. Several days later, the wound is inflamed and purulent. The exudate is cultured on blood agar and yields gram-negative rods. Antibiotic sensitivity tests are pending. The most likely agent to be isolated is
A. Bartonella henselae
B. Brucella canis
C. Clostridium tetani
D. Pasteurella multocida
E. Toxocara canis
Answer
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15.A 7-year-old boy is referred to a specialty clinic because of digestive problems. He often experiences severe abdominal cramps after eating a high fat meal. He is worked up and diagnosed with a genetic defect resulting in a deficiency of lipoprotein lipase. Which of the following substances would most likely be elevated in this patient's plasma following a fatty meal?
A. Albumin-bound free fatty acids
B. Chylomicrons
C. HDL
D. LDL
E. Unesterified fatty acids
Answer
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16>A 49-year-old woman is in an automobile accident and sustains a closed head injury. A CT scan does not show any intracranial hemorrhage, but reveals a small tumor at the cerebellopontine angle of the brain. Which of the following nerves is most likely to be affected by this tumor?
A. Facial nerve
B. Glossopharyngeal nerve
C. Optic nerve
D. Trigeminal nerve
E. Vagus nerve
Answer
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17>A 47-year-old male patient presents with painful arthritis in the right big toe and uric acid renal stones. He has been taking allopurinol for his condition. What biochemical defect would likely be found in this patient?
A. A defect in urea synthesis
B. An abnormality of the purine degradation pathway
C. An inability to synthesize non-essential amino acids
D. Defective topoisomerases
E. Increased levels of leukotrienes
Answer
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18>A 3-year-old boy is brought to the emergency department after the acute onset of headache, vomiting, nuchal rigidity, and impaired mental status. MRI reveals a posterior fossa tumor that fills the 4th ventricle. Surgery is immediately started, and intraoperative consultation leads to a "frozen section" diagnosis of medulloblastoma. Which of the following pathologic mechanisms most likely accounts for this child's clinical presentation?
A. Acute hemorrhage into the 4th ventricle
B. Alteration of medullary function
C. Increased intracranial pressure
D. Infiltration of the cerebellar vermis by the neoplasm
E. Spread of tumor to the subarachnoid space
Answer
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19>A diabetic mother gives birth to a baby who dies in the first week of life. Autopsy reveals a severe cardiac malformation. Which of the following is the most likely diagnosis?
A. Atrial septal defect
B. Coarctation of the aorta
C. Eisenmenger's syndrome
D. Tetralogy of Fallot
E. Transposition of the great arteries
Answer
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20>There is a classic zoo story about a cage with three monkeys in it. The largest monkey steals the middle-sized monkey's banana. The middle-sized monkey then screams with rage, hits the smallest monkey on the head, and then steals his banana. The middle-sized monkey is using which of the following mechanisms of defense?
A. Displacement
B. Projection
C. Reaction formation
D. Regression
E. Repression
Answer
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21>A 10-year-old boy has a small tumor in the wall of the right lateral ventricle. A biopsy of this tumor is consistent with subependymal giant cell astrocytoma. Which of the following lesions may also be present in this patient?
A. Café-au-lait spots
B. Cortical tubers
C. Hemangioblastoma
D. Lisch nodules
E. Schwannoma of the 8th cranial nerve
Answer
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22>Physical examination of a 45-year-old diabetic patient demonstrates a pulsatile abdominal mass. Radiographic studies demonstrate a 10-cm diameter aneurysm of the abdominal aorta with foci of calcification in the walls. Which of the following is the most likely etiology for the aneurysm?
A. Atherosclerosis
B. Congenital weakness
C. Cystic medial necrosis
D. Syphilis
E. Vasculitis
Answer
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23>A 19-year-old female, who recently moved from her family's home in another state, is hospitalized for attempting suicide by taking an overdose of antidepressant medications. On the third day of her hospital stay, she insists, under threat of a lawsuit, that her medications be stopped and that she be discharged from the hospital so she "can go home and finish the job." Her sensorium is clear. Her physician should
A. discharge her against medical advice (AMA)
B. honor her request and release her immediately
C. obtain an emergency order of detention
D. release her to go back to her parents' home
E. sedate her
Answer
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24>Which of the following could prevent an allergen from reacting with a specific IgE molecule present on the mast cell membrane?
A. Antihistamine
B. Blocking antibody
C. Cromolyn sodium
D. Epinephrine
E. Theophylline
Answer
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25>During a fight, a 32-year-old man is hit on the back of the neck with a chair. A CT scan reveals a bony fragment that penetrated the lateral portion of the dorsal columns. Which of the following functions would most likely be affected by a lesion at this site?
A. Fine motor control of the ipsilateral fingers
B. Motor control of the contralateral foot
C. Sweating of the ipsilateral face
D. Proprioception from the ipsilateral leg
E. Vibratory sense from the ipsilateral arm
Answer
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26>A 40-year-old, formerly obese woman presents to her physician. She was very proud of having lost 80 lbs. during the previous 2 years, but now noticed that her "hair is falling out." On questioning, she reports having followed a strict fat-free diet. Her alopecia is probably related to a deficiency of which of the following vitamins?
A. Vitamin A
B. Vitamin C
C. Vitamin D
D. Vitamin E
E. Vitamin K
Answer
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27>A 50-year-old woman presents with a 5-year history of headaches, generalized tonic-clonic seizures, and bilateral leg weakness. Skull films reveal hyperostosis of the calvarium. Biopsy of the responsible lesion shows a whorling pattern of the cells. Which of the following is the most likely diagnosis?
A. Arachnoid cyst
B. Glioblastoma multiforme
C. Meningioma
D. Metastatic breast cancer
E. Oligodendroglioma
Answer
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28>A 53-year-old man develops acute, excruciating chest pain that radiates to his back. En route to the emergency room, he becomes unresponsive, and is pulseless on arrival. Resuscitation attempts are unsuccessful. Autopsy reveals massive hemoperitoneum due to a ruptured aortic dissection. There is a jagged intimal tear in the ascending aorta, with a dissecting hematoma in the media, extending from the aortic valve to the renal arteries. Which feature of this scenario most strongly suggests hypertension as the cause of the aortic dissection?
A. Adventitial tear above renal arteries
B. Dissection through media
C. Involvement of major aortic branches
D. Origin at ascending aorta
E. Rapid exsanguination
Answer
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29>A 68-year-old, well-developed, well-nourished black male presents to the emergency department complaining of shortness of breath. He denies chest pain. He has no significant past medical history and takes no medications. A chest x-ray shows clear lung fields, mild cardiomegaly and a widened thoracic aorta with linear calcifications. An MRI of the chest shows aortic dilatation in the thorax, extending proximally, with atrophy of the muscularis and wrinkling of the intimal surface. What is the most likely etiology of this condition?
A. Atherosclerosis
B. Hypertension
C. Marfan's syndrome
D. Syphilis infection
E. Takayasu's arteritis
Answer
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30>A 60-year-old man presents to a physician because of difficulty in reading and coming down stairs, which he attributes to an inability to "look down." Physical examination reveals that the patient looks around by moving his head rather than his eyes and als o shows a distinctive axial rigidity of neck, trunk, and proximal limb muscles. He shows poverty of movement and dysarthric speech. Mentally, the patient responds very slowly but has better memory and intellect than are initially apparent. Which of the following pathologic findings of the brain would most likely be present?
A. Depigmentation of the substantia nigra and locus ceruleus
B. Diffuse cortical atrophy with relative sparing of primary motor and sensory areas
C. Selective frontal and temporal lobe atrophy
D. Striking degeneration of the caudate nucleus
E. Widespread neuronal loss and gliosis in subcortical sites
Answer
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31>At which of the following sites is the characteristic triple helical structure of the collagen initially formed?
A. Extracellular space
B. Golgi body
C. Nucleus
D. Rough endoplasmic reticulum
E. Smooth endoplasmic reticulum
Answer
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32>The nucleus that lies immediately medial (and deep) to the uncus is the
A. amygdala
B. caudate nucleus
C. claustrum
D. hippocampus
E. putamen
F. thalamus
Answer
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33>A 62-year-old female is brought to the emergency room by her husband with complaints of shortness of breath. Which of the following physical findings would be the most reliable indicator that she is experiencing heart failure?
A. A third heart sound (S3)
B. A fourth heart sound (S4)
C. Ascites
D. Orthopnea
E. Pulmonary rales
Answer
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34> A couple brings their son in to a specialty clinic for evaluation of recurrent bacterial infections involving the respiratory tract. Other family members have a similar disorder, as noted in the pedigree above. Which of the following is the most likely diagnosis?
A. Bruton's agammaglobulinemia
B. Common variable immunodeficiency
C. DiGeorge syndrome
D. Hereditary angioedema
E. Isolated IgA deficiency
Answer
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35>Two young boys are playing at a daycare center. One holds a ball on top of some blocks that the other child has placed on the floor. The second child helps steady the blocks, then the first child lets go of the ball , knocking the blocks down to the floor. They both watch and then repeat the process. These children are most likely
A. 10 months old
B. 16 months old
C. 18 months old
D. 24 months old
E. 48 months old
Answer
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36>In which of the following neurodegenerative conditions would you expect to observe the phenomenon known as anticipation?
A. Familial Alzheimer disease (FAD)
B. Familial amyotrophic lateral sclerosis (ALS)
C. Huntington disease
D. Pick disease
E. Progressive supranuclear palsy
Answer
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38>Which of the following antihistamines would be the most appropriate treatment for an airline pilot with hay fever?
A. Chlorpheniramine
B. Diphenhydramine
C. Meclizine
D. Pyrilamine
E. Terfenadine
Answer
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39>A newborn baby has multiple hemorrhages. Clotting studies demonstrate an elevated prothrombin time. An abnormality of which of the following biochemical processes is likely present in this patient?
A. Conversion of homocysteine to methionine
B. Conversion of methylmalonyl CoA to succinyl CoA
C. Degradation of cystathionine
D. Formation of gamma-carboxyglutamate residues
E. Hydroxylation of proline
Answer
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40>Examination of an autopsy specimen from a Mexican immigrant demonstrates a heart with massive dilation of the aortic root and adjacent aortic arch. Opening the aorta reveals a smooth interior wall without obvious lesions. If a histological section through the aortic wall is made, which of the following would most likely be seen?
A. A heavy eosinophilic infiltrate
B. Fibrinoid necrosis with a neutrophilic infiltration
C. Focal fragmentation of elastic elements
D. Obliterative endarteritis of the vasa vasorum
E. Ring-like calcification of the vessel media
Answer
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41>A 16-year-old girl is brought to emergency room by her parents for severe right foot pain. The patient states that the pain started 1 day prior to presentation. She cannot recall any recent trauma, and denies any past medical or surgical problem. She is active and walks at least 1 hour daily in the nearby forest. She goes to high school and is doing very well. She gets along well with her parents except that they insist she should eat more, as her weight has dropped from 130 to 105 pounds over the past year. Which of the following is the most likely diagnosis?
A. Conversion disorder
B. Depression with somatic manifestation
C. Injured medial ankle tendon
D. Metatarsal stress fracture
E. Tick bite
Answer
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42>A newborn has a heart rate of 130/min, irregular respirations, and active muscle movements with good tone. He coughs and grimaces in response to stimulation; he is pink in color, except for his hands and feet, which are slightly bluish. This neonate's APGAR score is
A. 6
B. 7
C. 8
D. 9
E. 10

43>Which of the following amino acids would most likely be found on the surface of a protein molecule?
A. Alanine
B. Arginine
C. Isoleucine
D. Leucine
E. Phenylalanine
F. Tryptophan
Answer
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44>A 46-year-old man sustains a spider bite on his upper eyelid, and an infection develops. The physician is very concerned about spread of the infection to the dural venous sinuses of the brain via emissary veins. With which of the following dural venous sinuses does the superior ophthalmic vein directly communicate?
A. Cavernous sinus
B. Occipital sinus
C. Sigmoid sinus
D. Superior petrosal sinus
E. Straight sinus
Answer
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45>A 10-week-old apparently healthy infant is laid down for a nap. The mother sits in a rocking chair nearby reading. At one point, she hears the baby make a single small cry, but she keeps reading because the baby quiets quickly. Later, she gets up to check on the child, whom she finds dead.Careful autopsy would be most likely to reveal which of the following cardiac findings?
A. Endocarditis
B. Failure of development of the endocardial cushion
C. Large interventricular septal defect
D. Mitral valve stenosis
E. Right ventricular hypertrophy
Answer
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46>A 40-year-old HIV-positive man with a CD4 cell count of 25/mm3 complains of progressive memory loss, confusion, and incontinence. MRI reveals moderate brain atrophy. The patient subsequently dies of disseminated aspergillosis. Autopsy confirms the presence of moderate cerebral atrophy. Histologically, there are multifocal lymphohistiocytic infiltrates with numerous microglial nodules and scattered multinucleated giant cells. Which of the following conditions was most likely responsible for this patient's neurologic symptoms?
A. Aspergillosis
B. CMV encephalitis
C. HIV encephalitis
D. Mycobacterial infection
E. Vacuolar myelopathy
Answer
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47> The pedigree above illustrates the mode of inheritance for which of the following diseases?
A. Glucose-6-phosphate dehydrogenase deficiency
B. Leber's hereditary optic neuropathy
C. Neurofibromatosis
D. Sickle cell anemia
E. Tay Sachs disease
Answer
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48>A 45-year-old man develops a large meningioma that compresses the brain. A head CT scan demonstrates a subfalcine herniation. This herniation would most likely damage which of the following structures?
A. Cerebellar tonsils
B. Cingulate gyrus
C. Medial temporal lobe
D. Medulla
E. Midbrain
Answer
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49>A middle-aged patient develops a gelatinous, well-circumscribed mass in her right cerebral hemisphere. Biopsy of the mass reveals neoplastic cells with a "fried egg" morphology. Which of the following tumors does this patient most likely have?
A. Choroid plexus papilloma
B. Ependymoma
C. Glioblastoma multiforme
D. Oligodendroglioma
E. Pilocytic astrocytoma
Answer
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50>A patient develops an excruciatingly painful infection of the anterior half of the external ear canal. Which of the following nerves transmits this impulse?
A. Auricular branch of the vagus
B. Auriculotemporal nerve
C. Greater auricular nerve
D. Lesser occipital nerve
E. Vestibulocochlear nerve
Answer
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