Basic USMLE VTH3

479) A 60-year-old man comes to the physician because of worsening fatigue and nausea. He had a carotid angiogram for the evaluation of symptomatic carotid artery stenosis 15 days ago, and was discharged home three days after the procedure. His medical problems are hypercholesterolemia, coronary artery disease, intermittent claudication, hypertension for 18 years, and diabetes mellitus for 15 years. Physical examination shows painless, reddish-blue mottling of the skin of the extremities. Laboratory studies show: Hb 10.5 g/dl, WBC 10,000/cmm with 12% eosinophils, BUN 46 mg/dl, Serum creatinine 3.0 mg/dl, Serum C3 level Decreased. Urinalysis:pH Normal,Esterase Negative, Nitrite Negative, Protein 1+, WBC Many eosinophils, RBC 1-2/HPF. Which of the following is the most likely cause of this patient's findings?

488) A 60-year-old white man comes into the Emergency Room with intensive retrosternal pain that began ten minutes ago. He has never had such pain before. His past medical history is significant for diabetes mellitus, type 2, controlled with diet. His blood pressure is 150/95 mmHg and HR is 80/min. You give him one chewable tablet of aspirin and two sublingual tablets of nitroglycerin with a 5-minute interval. After the second tablet of nitroglycerin, the pain is greatly relieved. What is the most important mechanism responsible for pain relief in this patient?

489) A 60-year-old woman comes to the physician because of a 3-month history of worsening fatigue and back pain. She has had diabetes mellitus for the past three years, and hypertension for the past ten years. Laboratory studies show: Hb 9.0 mg/dL, Serum calcium 11.2 mg/dL, Serum phosphorus 3.5 mg/dL, BUN 38 mg/dL, Serum creatinine 2.0 mg/dL. Which of the following is the most likely cause of this patient's renal failure?

491) A 60-year-old woman with heart failure and normal renal function is started on furosemide (Lasix) 80 mg/day. She notices a good diuretic response every time she takes the medication. A few weeks later, she is feeling unwell because of fatigue and muscle weakness, but her heart failure symptoms are better. Which of the following is the most likely explanation for her muscle weakness?

494) A 62-year-old man has progressive symptoms of dyspnea, and more recently noticed difficulty lying supine. Examination shows an elevated JVP at 8 cm, with a third heart sound, pedal edema, and bibasilar crackles on auscultation. Which one of the following may be implicated in fluid retention for this condition?

505) A 64-year-old man complains of palpitations and progressive shortness of breath over the past several hours. He says that he also develops a choking sensation every time he tries to lie down. His medical history is significant for hypertension for the past 20 years and medication non-compliance. He also has a 35-year smoking history. He reports that his father died of a heart attack at age 70 and his mother suffered from asthma. On physical examination, his blood pressure is 170/100 mmHg and his heat rate is 130/min and irregularly irregular. Lung exam reveals bibasilar crackles. There is 2+ pitting edema of the lower extremities. Bedside echocardiography shows a left ventricular ejection fraction of 55%. Which of the following is most likely responsible for his symptoms?

533) A 66-year-old man presents with a four week history of increasing back pain and severe constipation. He has no weakness or sensory symptoms in his legs. He takes acetaminophen for back pain, metoprolol for high blood pressure, and an over-the-counter fiber supplement for constipation. A screening colonoscopy 5-year ago was unremarkable. Rectal examination shows no abnormalities. Examination of the stool for occult blood is negative. His blood pressure is 135/80 mmHg and heart rate is 80/min. Abdominal examination shows no abnormalities. Laboratory studies show: Hb 9.5 g/dl, WBC 7,000/cmm, Platelets 300,000/cmm, BUN 28 mg/dl, Serum Creatinine 1.9 mg/dl, ESR 80/hr. Which of the following is the best explanation for this patient's constipation?

546) A 68-year-old woman presents with a pigmented lesion on the trunk. Upon further examination the lesion has an irregular border, darkening coloration, and raised surface. An incisional biopsy is performed and confirms a melanoma with a thickness of 0.5 mm. The patient is scheduled for a wide local excision of the melanoma in the operating room. Which of the following is the smallest margi recommended for excision?

557) A 70-year-old man is brought to the Emergency Room because he lost his consciousness while working in the garden. He says that he had several episodes of near-syncope on exertion recently. His past medical history is insignificant. He is not taking any medications. His blood pressure is 110/85 mmHg and heat rate is 80/min. Point of maximal impulse is increased in intensity. Cardiac auscultation reveals ejection type systolic murmur at the base of the heat with radiation to the carotid arteries. ECG demonstrates left ventricular hypertrophy, and secondary ST segment and T wave change. What is the most probable cause of this patient's condition?

559) A 71-year-old man is brought to the ER after a witnessed tonic-clonic seizure. He is somnolent and intermittently combative on exam. No past medical history is available. His arterial blood gas (ABG) at room air is given below: pH 7.23, pCO2 69 mmHg, pO2 57 mmHg, HCO3 28 mmHg. Which of the following best explains the acid-base disturbances in this patient?

563) A 72-year-old man with coronary artery disease and hypertension is hospitalized after suffering a myocardial infarction 5 days ago. He suddenly complains of severe chest pain. His blood pressure is 90/60 mmHg and heart rate is 65/min. Auscultation reveals no murmurs or rubs. An ECG reveals sinus rhythm with an acute ST-segment elevation in the anteroseptal area. Urgent bedside echocardiography showed anteroseptal, lateral, and apical akinesis, mild left ventricular systolic dysfunction, and severe pericardial effusion. Within 20 minutes he is unconscious with undetectable pulses and blood pressure. What is the most likely cause of the patient’s sudden decompensation?

569) A 73-year-old man from a nursing home develops headache, fever, cough, sore throat, malaise, and severe myalgia during a community outbreak affecting numerous other residents at the home. The symptoms gradually resolve after 3 days, and he starts feeling better but then there is a reappearance of his fever, with cough and yellow sputum production. On examination, his temperature is 38.5°C, pulse 100/min, respiration 24/min, oxygen saturation 88% and crackles in the right lower lung base, bronchial breath sounds and dullness on percussion. CXR reveals a new infiltrate in the right lower lobe. Which of the following is the most likely causative organism?

572) A 73-year-old woman presents to the emergency room with black tarry stools and symptoms of presyncope when standing up. Digital rectal examination confirms the presence of melena. She recently started using ibuprofen for hip discomfort. Upper endoscopy confirms the diagnosis of a gastric ulcer. Which of the following is the most likely explanation for the gastric ulcer?

576) A 74-year-old nursing home resident is brought to the ER with a low-grade fever, cough and shortness of breath for the last two days. The cough is productive of small amounts of greenish sputum. His past medical history is significant for hypertension, diabetes mellitus type 2, COPD, hypercholesterolemia and mild dementia. His blood pressure is 152/78 mmHg and his heart rate is 89/min, regular. Physical examination reveals decreased breath sounds, coarse rhonchi, and increased fremitus over the lower left lung field. His oxygen saturation is 92% on room air when lying on his right side but drops to 84% when he lies on his left. Which of the following best explains this finding?

579) A 75-year-old female nursing home resident complains of cough and fever. Her past medical history is significant for hypertension, myocardial infarction (experienced two years ago), and a traumatic right foot amputation. Her current medications are atenolol, hydrochlorothiazide, and aspirin. Her temperature is 39.4°C (103°F), pulse is 110/min, respirations are 22/min, and blood pressure is 110/76 mmHg. Crackles are present at right lung base. Chest x-ray reveals a right lower lobe infiltrate. Which of the following pathogens is the most likely cause of this patient's condition?

588) A 9-month-old African American boy is brought to the office by his parents due to swelling of the feet and hands for the past two days, accompanied by poor feeding and fussiness. His vital signs are stable, except for a temperature of 38.3C (101 F). He appears pale. On examination, the dorsal surface of his hands and feet on both sides are swollen and tender, with restricted range of movement. He is an adopted child, and his family history is not available. Radiography of the feet and hands reveal soft tissue swelling. What is the pathophysiology of this patient's presentation?

589) A 9-year-old boy has a severe sore throat with fever and dysphagia. On examination, there are grayish-white papulovesicular lesions on an erythematous base that ulcerate. They are located on the soft palate, anterior pillars of the tonsils and uvula. There are no lesions on the gingiva, tongue, or lips. A clinical diagnosis of herpangina is made. Which of the following is the most likely causative organism?

591) A 9-year-old boy is brought to the emergency department due to an episode of seizures during class. His teacher says that the seizure started suddenly, and he fell to the ground with sustained flexion of the arms and extension of the legs, followed by clonic movements of the whole body. He has also been irritable lately, and his school performance has declined. His parents arrive shortly and say that they recently noticed he was lethargic and frequently complained of headaches, especially in the morning. His medical history is unremarkable. Physical examination reveals decreased muscle strength of the left side of the body, with brisk deep tendon reflexes in the left arm and leg. MRI of the head reveals a space-occupying lesion in the right parietal lobe. What tumor is most likely responsible for this patient's symptoms?

594) A 9-year-old child has developed headaches that are more frequent in the morning and are followed by vomiting. Over the previous few months, his family has noted a change in his behavior (generally more irritable than usual) and his school performance has begun to drop. Imaging of this child is most likely to reveal a lesion in which of the following regions?

615) A mother delivers a neonate with meconium staining and Apgar scores of 3 at 1 and 5 minutes of life. She had no prenatal care and the delivery was by emergency cesarean section for what the obstetricians report as “severe fetal bradycardia.”Which of the following sequelae could be expected to develop in this intubated neonate with respiratory distress?

625) A one-year-old girl is brought to the office for the evaluation of sickle cell anemia. Both her parents have sickle cell trait, and her elder sister has sickle cell anemia. Her vital signs are stable. Her height and weight are appropriate for age. On examination, she appears healthy and normal. Her birth and past medical histories are insignificant. Hemoglobin electrophoresis reveals 40% hemoglobin S. What is the most common presentation of this condition?

629) A patient requires both cardiac and renal transplantation. Preparation for the procedures has begun. How do cardiac allografts differ from renal allografts?

635) A pregnant 35-year-old patient is at highest risk for the concurrent development of which of the following malignancies?

638) A premature neonate with respiratory distress syndrome is maintained on mechanical ventilation in a neonatal intensive care unit. Two weeks after delivery, the nurses in the intensive care unit notice that higher ventilation settings are needed and that more secretions are being suctioned from the endotracheal tube. A chest x-ray film shows questionable new infiltrates. Which of the following is the most likely pathogen?

649) A term boy with Apgar scores of 9 and 9 at 1 and 5 minutes has failed to pass meconium at 72 hours. He has had no episodes of emesis, and his abdomen is only mildly distended to palpation. The patient’s mother reports that her older son had the same problem at birth. A plain radiograph of the abdomen shows a small bowel obstruction with numerous air-filled loops of bowel. The patient is treated with a diatrizoate meglumine (Gastrografin) enema, with good results. Which of the following is the most likely mechanism for this infant’s acute intestinal problem?

653) A wealthy American executive donates five million dollars for the prevention of intrauterine growth restriction in the local county. Spending this money on which of the following programs would prevent the greatest number of cases of fetal growth restriction (FGR) in the population?

655) A woman gives birth to twins at 38 weeks’ gestation. The first twin weighs 2800 g (6 lb, 3 oz) and has a hematocrit of 70%; the second twin weighs 2100 g (4 lb, 10 oz) and has a hematocrit of 40%. Which of the following statements is correct?

657) After an uneventful labor and delivery, an infant is born at 32 weeks’ gestation weighing 1500 g (3 lb, 5 oz). Respiratory difficulty develops immediately after birth and increases in intensity thereafter. At 6 hours of age, the child’s respiratory rate is 60 breaths per minute. Examination reveals grunting, intercostal retraction, nasal flaring, and marked cyanosis in room air. Auscultation reveals poor air movement. Physiologic abnormalities compatible with these data include which of the following?

658) After delivery of a term infant with Apgar scores of 2 at 1 minute and 7 at 5 minutes, you ask that umbilical cord blood be collected for pH. The umbilical arteries carry which of the following?

659) After reading an article titled: ''The Risk of Cancer in Patients with Diethylstilbestrol (DES) Exposed Mothers", a 23-year old female comes to your office with her mother for assessment of possible risks. Her mother had been given DES while pregnant. Which of the following cancers is this patient most at risk of developing?

662) An 18-month-old child presents to the emergency center having had a brief, generalized tonic-clonic seizure. He is now postictal and has a temperature of 40C (104F). During the lumbar puncture (which ultimately proves to be normal), he has a large, watery stool that has both blood and mucus in it. Which of the following is the most likely diagnosis in this patient?

664) An 18-month-old male infant is brought to the office by his parents for a follow-up visit. He has a congenital condition that started at the age of 6 months with repeated vomiting and hypotonia, and progressively evolved into choreoathetosis, spasticity and dystonia. Over the past month, he has started biting his hands and arms, pinching himself and banging his limbs against the wall. His family history is unremarkable. On examination, he has several scars, cuts and bruises over his arms and hands. His uric acid levels are elevated. What is the most likely deficient enzyme in this patient?

665) An 18-month-old male is brought to the hospital because of fever, dyspnea, and productive cough of two days duration. His mother reports that he just recovered from prolonged diarrhea due to Giardia infection. His past medical history is also significant for pneumonia and recurrent ear infections since 6 months of age. On physical examination, his temperature is 38.7°C (101.7°F), pulse is 140/min, and respirations are 40/min. Examination reveals a young child in mild respiratory distress and bronchial breath sounds in the right lower lung lobe. Which of the following is the most likely cause of his recurrent infections

667) An 18-year-old man develops fever, neck stiff- ness, and headache. On examination, his blood pressure is 110/80 mm Hg, pulse 100/min, temperature 38.7°C, and neck flexion is very painful. The ears, throat, and sinuses are normal; there are no focal neurologic signs; and the remaining examination is normal. There are no reported similar cases in the community. Which of the following is the most likely causative organism?

668) An 18-year-old man develops fever, neck stiffness, and headache. On examination, his blood pressure is 105/80 mm Hg, pulse 100/min, temperature 38.7°C, and neck flexion is very painful. The ears, throat, and sinuses are normal; there are no focal neurologic signs, and the remaining examination is normal. His is the second case of meningitis in his university dormitory building. Which of the following is the most likely causative organism?

671) An 8-month-old previously preterm infant with bronchopulmonary dysplasia presents to the emergency department with lethargy. His regular medications include furosemide and spironolactone. His temperature is 37.4 C (99.3 F), blood pressure is 68/32 mm Hg, pulse is 110/min, and respirations are 10/min. He has poor skin turgor and dry mucous membranes. Laboratory chemistry evaluation reveals: sodium, 131 mEq/L; potassium, 3.0 mEq/L; chloride, 84 mEq/L; bicarbonate, 38 mEq/L; blood urea nitrogen, 36 mg/dL; and creatinine, 0.4 mg/dL. An arterial blood gas shows pH, 7.52; PaCO2: 49 mm Hg; and PaO2: 92 mm Hg. Which of the following is the most likely explanation for these findings?

672) An 8-year-old boy is brought to the office by his mother for a routine check-up. He has fair skin, blond hair and blue eyes. His past medical history is insignificant. His mother wants to know what the best possible photo-protection is for her son, because "his skin has always been sensitive to the sun, and he is almost unable to tan." He had two episodes of sunburn recently. Physical examination reveals several junctional nevi. Which of the following is the best response to this patient's mother?

674) An 8-year-old boy with sickle cell disease presents with left leg pain and a high fever. He has been refusing to walk since yesterday. On physical examination, his temperature is 39.8 C (103.6 F), blood pressure is 122/68 mm Hg, pulse is 102/min, and respirations are 20/min. His left femur is tender to palpation 3 cm above the left knee, and there is marked soft tissue swelling. A plain film of his left leg is normal. A bone scan shows increased uptake around the metaphysis of the left femur. Which of the following is the most likely pathogen?

687) An infant comes to the office for his 1-year check-up. His father states that he is worried that his son is smaller than he should be. The child's weight is 8.6 kg (19 lb), and his length is 71 cm (28 in). He appears to be growing appropriately on his growth curve. Which of the following is the most appropriate explanation about growth to be given to the father?

690) An infant is brought to a hospital because her wet diapers turn black when they are exposed to air. Physical examination is normal. Urine is positive both for reducing substance and when tested with ferric chloride. This disorder is caused by a deficiency of which of the following?

692) An infant is due for her first dose of polio vaccine. Her parents have heard that there are two different types of vaccine for polio. They want to know why their daughter needs to get another shot rather than just taking the oral form of the vaccine. You tell the parents the major advantage of the injectable vaccine is which of the following?

693) An obese 18-year-old woman is brought to the emergency department by her mother, who noted that she had been lethargic all day, and suffered a brief, seizure-like episode. One month earlier, the patient had been started on medication for type 2 DM. Lactic acid levels are normal. Which of the following medications most likely played a role in the patient’s current presentation?

694) An otherwise healthy 13-year-old boy has seasonal allergic rhinitis. He complains of excessive rhinorrhea, frequent sneezing, and nasal congestion. He has a nasal voice and breathes with his mouth. He derives some relief from keeping windows closed at home and spending as litde time as possible outdoors in periods of high pollen concentration. However, he is excessively bothered by nasal congestion. Which of the following drugs would be most effective in relieving nasal congestion?

700) At birth, an infant is noted to have an abnormal neurologic examination. Over the next few weeks he develops severe progressive central nervous system (CNS) degeneration, an enlarged liver and spleen, macroglossia, coarse facial features, and a cherry-red spot in the eye. Which of the following laboratory findings most likely explains this child’s problem?

701) During routine breast examination of a 28-year-old woman with no significant family or past medical history, a firm 2-cm mass is detected in the patient’s right breast. It is freely mobile and non-tender. Ultrasound reveals a solid, well-circumscribed mass, which is later found to be benign by biopsy. Which of the following statements is true?

703) During the examination of a 2-month-old infant, you note that the infant’s umbilical cord is still firmly attached. This finding prompts you to suspect which of the following?

706) In a failed suicide gesture, a depressed student severs her radial nerve at the wrist. Which of the following is her expected disability?

710) On pelvic examination of a patient in labor at 34 weeks, the patient is noted to be 6 cm dilated, completely effaced with the fetal nose and mouth palpable. The chin is pointing toward the maternal left hip. This is an example of which of the following?

711) One day after a casual sexual encounter with a bisexual man recently diagnosed as antibody-positive for human immunodeficiency virus (HIV), a patient is concerned about whether she may have become infected. A negative antibody titer is obtained. To test for seroconversion, when is the earliest you should reschedule repeat antibody testing after the sexual encounter?

716) The mother and father of a newborn come in for the 2-week check-up. The mother complains of “colic” and asks if she can switch to goat’s milk instead of breast milk. Which of the following should be your main concern about using goat’s milk instead of breast milk or cow’s milk?

718) The parents of a 1-month-old infant bring him to the emergency center in your local hospital for emesis and listlessness. Both of his parents wanted a natural birth, so he was born at home and has not yet been to see a physician. On examination, you find a dehydrated, listless, and irritable infant. Although you don’t have a birth weight, the parents do not feel that he has gained much weight. He has significant jaundice. His abdominal examination is significant for both hepatomegaly and splenomegaly. Laboratory values include a total bilirubin of 15.8 mg/dL and a direct bilirubin of 5.5 mg/dL. His liver function tests are elevated and his serum glucose is 38 mg/dL. Serum ammonia is normal. A urinalysis is negative for glucose, but it has a “mouse-like” odor. These findings are consistent with which of the following conditions?

724) Three hours after a church social, eight people develop severe diarrhea. Other symptoms included nausea, vomiting, and abdominal cramps. Food served included chicken salad and cream-filled pastries. All affected individuals had the chicken salad. Which of the fol- lowing is the most likely causative organism?

727) Which of the following patients with primary hyperparathyroidism should undergo parathyroidectomy?

729) Which of the following statements is true regarding contraception?

732) While playing with his children, a 44-year-old man falls and lands on his right shoulder. There is immediate pain and deformity. In an uncomplicated dislocation of the glenohumeral joint, the humeral head usually dislocates primarily in which of the following directions?

738) You are working in the ED on a Sunday afternoon when four people present with acute-onset vomiting and crampy abdominal pain. They were all at the same picnic and ate most of the same foods. The vomiting began approximately 4 hours into the picnic. They deny having any diarrhea. You believe they may have “food poisoning” so you place IV lines, administer IV fluids, and observe. Over the next few hours, the patients begin to improve, the vomiting stops, and their abdominal pain resolves. Which of the following is the most likely cause of their presentation?