USMLE Med basic 1

1) A 74-year-old man presents to your office for a routine. He has no present complaint. His medical history is significant for right knee osteoarthritis. He takes naproxen occasionally, to relieve knee pain. He does not smoke or consume alcohol. His BP is 165/75 mmHg and PR is 70/min. The physical examination showed a mild systolic ejection type murmur at the base of the heat to the right. An E-KG revealed left ventricular hypertrophy and secondary ST segment and T wave change. Moderate left ventricular hypertrophy, without any flow abnormalities, was demonstrated on echocardiography. The ejection fraction was 60%. What is the most probable cause of hypertension in this patient?

2) A 47-year-old woman loses consciousness for 2 minutes while shopping in a supermarket. In the emergency room, she recounts feeling nausea and warmth spreading over her body immediately before passing out. She has never had a similar episode before. She has not seen a doctor for several years and does not take any medications, nor does she use tobacco, alcohol or drug. Her family history is unremarkable. Which of the following most likely caused this episode?

3) A 25-year-old woman experiences sudden-onset palpitations and generalized weakness. During this episode, her blood pressure is 100/60 mmHg and her heat rate is 160/min and regular. She has no significant past medical history and does not take any medications. She reports having a few similar episodes in the past which she has self-treated by immersing her face in cold water. Generally, she says, cold water immersion relieves her symptoms within several minutes. This cold water therapy works by affecting which of the following?

4) A 67-year-old man is evaluated for hypertension. He complains of occasional morning headaches. His past medical history is also significant for type 2 diabetes mellitus, coronary artery disease, and a stroke with residual left-sided weakness. He underwent coronary artery bypass surgery seven years ago and carotid endarterectomy five years ago. His current medication list includes lisinopril hydrochlorothiazide, amlodipine, metoprolol, aspirin, metformin and glyburide. His blood pressure is 190/120 mmHg on the right arm and 170/110 mmHg on the left arm. His heat rate is 65/min Physical examination reveals a periumbilical systolic-diastolic bruit. The latter finding is best explained by which of the following?

5) A 67-year-old male is brought to the emergency department after a syncopal episode. He lost consciousness while shopping in the mall. He denies any nausea, diaphoresis, chest pain, or shortness of breath. He has had two episodes of lightheadedness over the last month but has not seen a doctor. His past medical history is significant for long-standing hypertension, which is being treated with enalapril. His blood pressure is 135/90 mmHg while supine, and 130/85 mmHg while standing. His heat rate is 64/min. ECG shows a sinus rhythm with high voltage, prolonged PR interval, prolonged QRS interval, normal QT interval and occasional premature ventricular contractions (PVC). Echocardiography reveals left ventricular hypertrophy and an ejection fraction (EF) of 55%. Which of the following is the most likely cause of this patient's syncope?

6) A 47-year-old male presents to your office with a two-month history of lethargy and decreased libido. His medical records reveal that he has been treated for joint pain and swelling over the last six months and was diagnosed with diabetes mellitus one year ago. Physical examination reveals hepatomegaly and testicular atrophy. Which of the following cardiac abnormalities is most likely to also be present in this patient?

7) A 50-year-old woman presents to your office complaining of lower extremity edema that stated several weeks ago, and slowly progressed thereafter. Her past medical history is significant for hypertension, treated with metoprolol for 2 years. Amlodipine was added recently because of inadequate control of BP with metoprolol alone. She does not smoke or consume alcohol. She has no known drug allergies. Her blood pressure is 130/80mmHg and her heart rate is 64/min. The physical examination reveals bilateral symmetric 3+ pitting edema of both lower extremities, without any skin changes or varicosities. Her neck vein pulsation is normal. Other physical findings are within normal limits. Her laboratory studies reveal the following: Serum albumin 4.5 g/dL, Total serum bilirubin 0.8 mg/dL, Serum sodium 140 mEq/L, Serum potassium 4.0 mEq/L, Serum creatinine 0.8 mg/dL. Urinalysis is within normal limite. What is the most likely cause of the edema in this patient?

8) A 63-year-old man presents to the ER with substernal chest pain and diaphoresis. The pain stated one hour ago and did not remit with antacids. He has a past medical history of asthma for which he uses inhaled fluticasone and peptic ulcer disease for which he takes omeprazole. His family history is significant for prostate cancer in his father and breast cancer in his mother. Physical examination reveals a blood pressure of 160/100 mmHg and a heat rate of 90/min. A bruit is heard over the right carotid artery and a mild systolic murmur is present at the cardiac apex. Sublingual nitroglycerin and aspirin are administered in the. Within minutes, the patient reports decreased pain. Which of the following most likely accounts for this improvement in his symptoms?

9) A 38-year-old female comes to your office complaining of occasional palpitations. She describes feeling a fast and irregular heartbeat. Over the past two months, she has had three such episodes, each lasting about two hours. She denies any associated chest pain, shortness of breath cough or ankle swelling. She drinks alcohol on social occasions and does not smoke cigarettes. She has no other medical problems and is not taking any medications. On physical examination, her temperature is 37.1°C (98.9°F), pulse is 80/min, blood pressure is 130/70mmHg, and respirations are 14/min. On auscultation of her heat the apical impulse is displaced and there is an S3. You also hear a pansystolic murmur, which is loudest at the apex and radiates to the axilla. Which of the following is the most likely cause of her symptoms?

10) A 42-year-old woman is evaluated for depression, mood swings and poor. She also complains of mild headaches and muscle weakness. She has had two ER visits for kidney stones over the past year. She denies any illicit drug use. Her blood pressure is 160/105 mmHg and her heat rate is 85/min. Her laboratory findings are shown below: Sodium 140mEq/L, Potassium 3.6 mEq/L, Chloride 101 mEq/L, Bicarbonate 24 mEq/L, BUN 13 mEq/L, Creatinine 0.9 mEq/L, Glucose 98 mEq/L, Calcium 11.7 mg/dL. Which of the following is the most likely cause of this patient's hypertension?

11) A 14-year-old African American male is referred to your office after his older brother experienced sudden cardiac arrest during hiking trip. He has no current complaints. He denies any illicit drug use. His blood pressure is 110/60 mmHg and his heat rate is 75/min. Neck is supple, no jugular venous distention is appreciated. Carotid pulse seems to have dual upstroke. Lungs are clear. There is strong apical impulse and a systolic ejection type murmur along the left sternal border. Which of the following is most likely to increase the murmur intensity in this patient?

12) A 60-year-old male is brought to ER by his son because he had an episode of syncope. He was watching TV in an arm-chair when suddenly lost his consciousness without any warning sign. He had several clonic jerks while unconscious. He never had such an episode before. His past medical history is significant for acute myocardial infarction six months ago and well-controlled hypertension. His current medications include captopril metoprolol hydrochlorothiazide, clopidogrel and aspirin. His blood pressure is 130/85 mmHg and heat rate is 80/min with frequent ectopic beat. Physical examination revealed mild holosystolic apical murmur radiating to the axilla. Which of the following is the most probable pathophysiologic mechanism for his syncopal episode?

13) A 54 year-old male comes to the physician because of abdominal distention. He thinks his big belly is making it hard for him to breathe. He received radiation therapy for Hodgkin lymphoma several years ago and was told that he is cured. He drinks alcohol on a regular basis. His temperature is 36.7°C (98°F), blood pressure is 120/76 mm Hg, pulse is 80/min and respirations are 20/min. Examination shows a jugular venous pressure 7 cm above the sternal angle. Dullness to percussion and decreased breath sounds are noted in the right lung base. The abdomen is quite distended with an obvious fluid wave. Mild hepatomegaly is present. Extremities have 2+ lower extremity edema. Initial laboratory studies are shown below: Serum creatinine 08 mg/dL, Alburnin 4.0 mg/dL, Total bihrubin 1.0 mg/dl, Prothrombin time 11 sec. Urinalysis is within normal limits. Which of the following is the most likely cause of his condition?

14) A 32-year-old woman presents with progressively worsening dyspnea on exertion one month after returning from a vacation in Texas. She says that her symptoms have progressed to the point that she now wakes during the night with a choking sensation that improves only with sitting up. Recently her shortness of breath has required her to significantly limit her physical activity. She denies having associated chest pain, skin rash or joint pain. She has no significant past medical history. Family history is significant for thyroid cancer in her aunt and lung cancer in her father, a heavy smoker. On physical examination, her temperature is 37.2°C (99°F), pulse is 96/min, blood pressure is 110/70 mmHg, and respirations are 14/min. Bilateral pitting ankle edema is present. Her liver is enlarged 2 cm below the right costal marginal. Lung auscultation reveals decreased breath sounds at the bilateral bases. Cardiac exam reveals the presence of a third heat sound. Chest x ray shows an enlarged cardiac silhouette and small bilateral pleural effusion. EKG is unremarkable. Which of the following is the most likely cause of her symptoms?

15) An 88-year-old female nursing home resident is brought to the hospital with a one-week history of moaning, decreased oral intake and decreased ambulation. Physical examination reveals a very thin female who is moaning and appears to be in pain. She opens her eyes spontaneously but does not respond to questions. Her blood pressure is 75/43 mmHg, pulse is 105/min, temperature is 35.5°C (96°F), and respirations are 22/min. Oxygen saturation (pulse oximetry) is 97% on room air. Her skin and oral mucosa are dry and her neck veins are flat. There is no lymphadenopathy. On chest auscultation, there are crackles in the right upper lung lobe. Abdomen is soft and non-distended. There is 2+ pitting presacral and lower extremity edema, and a deep pressure ulcer in the sacral area. Laboratory analysis reveals the following: Sodium 155mEq/L, Potassium 5.3 mEq/L, Glucose 88mg/dL, Bicarbonate 14mEq/L, BUN 151mg/dL, Creatinine 3.1mg/dl. Which of the following is the most likely cause of her lower extremity edema?

16) 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?

17) A 55-year-old Caucasian male presents to your office with muscle pain of recent onset. His past medical history is significant for hypertension and an acute myocardial infarction experienced 2 months ago. His current medications include metoprolol captopril, aspirin and simvastatin. His blood pressure is 130/80 mmHg and heat rate is 60/min. Liver function tests are slightly abnormal. Serum creatine kinase level is elevated. You suspect a drug-induced reaction. Which of the following is the most possible mechanism of drug-induced reaction in this patient?

18) 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?

19) A 32-year-old male complains of progressive weakness and exertional dyspnea. His past medical history is significant for a knife injury to the right thigh two months ago. He has been arrested several times for robbery. He consumes alcohol regularly, and smokes crack occasionally. His younger brother died of cystic fibrosis. His blood pressure is 160/60 mmHg, and heart rate is 100/min. His extremities are warm and flushed. Carotid upstroke is brisk. The point of maximal impulse is displaced to the left, and a soft, holosystolic murmur is heard over the cardiac apex. The murmur does not change with the Valsalva maneuver. Which of the following is the most likely cause of this patient's symptoms?

20) A 22-year-old college student went to the health clinic complaining of a fever over the last 5 days, fatigue, myalgias, and a bout of vomiting and diarrhea. The clinic doctor diagnosed him with acute gastroenteritis and told him to drink more fluids. Three days later, the student presents to the ED complaining of substernal chest pain that is constant. He also feels short of breath. His temperature is 100.9°F, HR is 119 beats per minute, BP is 120/75 mmHg, and RR is 18 breaths per minute. An ECG is performed revealing sinus tachycardia. A chest radiograph is unremarkable. Laboratory tests are normal except for slightly elevated WBCs. Which of the following is the most common cause of this patient’s diagnosis?

21) A 60-year-old man is brought to the ER by his wife because he lost consciousness in the bathroom at night. He says that he woke up, went to the bathroom to urinate, and fainted there. He rapidly recovered his consciousness without any indication of disorientation. He has never had such an episode before. He admits' problems with urination,' including difficulty with initiating urination and frequent awakening to void at night. He does not take any medication. His past medical history is insignificant. He smokes 2 packs of cigarettes per day and does not consume alcohol. His blood pressure is 130/80 mmHg while supine, and 132/80 mmHg while standing. His heart rate is 70/min. His physical examination is within normal limits. The ECG is normal. What is the most probable cause of the syncopal episode in this patient?

22) A 73-year-old man presents to the ED after a syncopal episode. He had been resting in bed for approximately one week after injuring his right knee. This morning, his knee felt better and he attempted to get up from bed. However, upon attempting to stand, he sustained a brief loss of consciousness. He had no symptoms or medical history prior to the knee injury. Medications include acetaminophen and ibuprofen for knee pain. On exam, his pulse is 73/min, respirations are 14/min, and blood pressure is 136/83 mmHg. Which of the following is the most likely cause of this patient's syncope?

23) A 46-year-old woman is hospitalized for agitation, restlessness and poor sleep. She has been complaining of headaches recently and has gained 14 pounds over the past three months. She denies any illicit drug use. Her blood pressure is 160/110 mmHg and her heart rate is 90/min. Her laboratory findings are shown below: Sodium 142 mEq/L, Potassium 3.2 mEq/L, Chloride 98 mEq/L, Bicarbonate 26 mEq/L, BUN 12 mg/dl, Creatinine 0.9 mg/dl, Glucose 205 mg/dl, Calcium 94 mg/dl. Which of the following is the most likely cause of this patient's hypertension?

24) A 53-year-old man presents to the emergency room with squeezing chest pain that started two hours ago. He also complains of shortness of breath that is worse when lying down. He has never had pain like this before. He has no significant past medical history and he takes no medications. A routine health maintenance visit two weeks ago was normal. On physical examination in the ER, his blood pressure is 140/90 mmHg and his heart rate is 100/min. Chest auscultation reveals a grade II/VI blowing systolic murmur at the cardiac apex and bibasilar crackles in the lungs. ECG shows ST segment elevations in leads I, aVL, and v1-v3. Which of the following is most likely increased in this patient?

25) A 35-year-old woman who has recently emigrated from Asia presents to the emergency room with acute onset of dyspnea. She denies any cough, chest pain, or fever. She has a history of rheumatic heart disease as a teen. On examination, she has an irregular pulse of 97/min, blood pressure of 125/75 mmHg and temperature of 37.2°C (98.9°F). The first heart sound is loud and a mid-diastolic rumble is heard at the apex. Crackles are present in both lung fields. ECG shows an irregularly, irregular heart rhythm and the absence of 'P' waves. Which of the following is the most likely cause of this patient's abnormal heart rhythm?

26) An 82-year-old male presents for evaluation of chronic back pain. On physical examination, he is found to have a blood pressure of 160/85 mmHg while supine and 135/70 mmHg while standing. He is otherwise healthy; his only medicine is occasional ibuprofen for back pain. Which of the following age-related changes best explains the observed finding?

28) A 24-year-old male experiences syncope while shovelling snow. He regained consciousness within one minute. He has been having some shortness of breath and chest pains recently, mostly related to exercise. He denies any illicit drug use. His temperature is 37.2°C (98.9°F), and blood pressure is 126/76 mmHg, pulse is 76/min and respirations are 14/min. Physical examination shows a well-built male in no apparent distress. Lungs are clear. A crescendo-decrescendo systolic murmur is heard along the left sternal border without carotid radiation. Chest X-ray is normal. Which of the following is the most likely cause of his syncopal episode?

29) A 33-year-old woman is undergoing an elective, open cholecystectomy after 2 episodes of acute calculous cholecystitis. She suddenly becomes hypotensive, and a generalized rash is noted. Her past medical history is significant for a hypotensive episode 8 weeks ago while having protected sex with her new partner. Which of the following is the most probable cause of this patient's condition?

30) A 72-year-old male comes to the office with intermittent symptoms of dyspnea on exertion, palpitations, and cough occasionally productive of blood. On cardiac auscultation, a low-pitched diastolic rumbling murmur is faintly heard at the apex. What is the most likely cause of the murmur?

31) A 53-year-old male presents to your office with a two-day history of right calf pain and swelling. He describes the pain as constant and states that it is exacerbated by knee flexion. He has a history of past IV drug abuse, endocarditis, and stroke. He is currently wheelchair-bound secondary to stroke-related left-sided hemiparesis. On physical examination, his blood pressure is 140/90 mmHg and his heart rate is 100/min. There is no jugular venous distention or hepato-jugular reflux. His chest is clear to auscultation but his abdomen is enlarged with shifting dullness and a fluid wave, suggestive of ascites. His liver is palpable 3 cm below the right costal margin. His spleen is also palpable. On examination of his lower extremities, you note right-sided calf swelling and tenderness. Which of the following is the most likely cause of this patient's ascites?

32) 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?

33) A 34-year-old male who recently immigrated from Brazil presents with a 5-month history of exertional dyspnea without associated chest pain, palpitations, dizziness, or syncope. His past medical history is significant for an episode of megacolon, which was treated 2 years ago. On physical examination, there is 1+ pedal edema and mild jugular venous distention. Cardiac exam is significant for the presence of an S3, but no murmurs are heard. Chest x-ray reveals prominent cardiomegaly. Based on these findings, which of the following is most likely causing his symptoms?

34) A 12-year-old African American male is found to have a murmur during a routine sports physical. He has a family history of sudden death at a young age. It is a harsh crescendo-decrescendo murmur that begins after S1 and is best heard at the left lower sternal border. Valsalva maneuver intensifies the murmur. Which of the following is the most likely mitral valve abnormality in this patient?

35) A 63-year-old woman with a long history of hypertension faints after experiencing the sudden onset of severe chest pain that radiates to her back. She is rushed to the emergency room. Upon arrival she is agitated and demands quick pain relief. Her heart rate is 110/min and blood pressure is 90/50 mmHg. Jugular veins are distended. An intra-arterial catheter shows significant variation of systolic blood pressure related to the respiratory cycle. Chest x-ray reveals widening of the mediastinum. Which of the following is the most likely cause of this patient's syncope?

36) A 47-year-old male was brought to the emergency room with chest pain of acute onset. The pain was associated with nausea, vomiting, and diaphoresis. He has a history of diabetes, hypertension, and hyperlipidemia. ECG reveals ST segment elevation in the anterolateral leads and ventricular premature beats (VPBs). The patient dies within the first hour after the arrival to emergency room. What is the most likely pathophysiologic mechanism responsible for this patient's death?

37) A 57-year-old male presents to your office with a two week history of fever, chills, and generalized weakness. His medical history is significant for a hospitalization for pyelonephritis requiring IV antibiotics six months ago. He also recently underwent cystoscopy for evaluation of persistent dysuria. His past medical history is also significant for an episode of rheumatic fever as a child and Hodgkin's lymphoma treated with chemotherapy 10 years ago. On examination, his temperature is 37.8°C (100°F), blood pressure is 150/86 mmHg, pulse is 98/min and regular, and respirations are 16/min. The patient appears slightly diaphoretic. You note a new II/VI systolic murmur and tender erythematous lesions affecting several fingertips. The remainder of the physical examination is unremarkable. Which of the following bacteria is most likely responsible for his present illness?

38) A 65-year-old man complains of lower leg swelling, fatigue and poor appetite. His past medical history is significant for recurrent chest infections, wheezing, cough, recent pyelonephritis, and arterial hypertension. He smokes 1 pack of cigarettes a day but denies alcohol or intravenous drug use. His physical examination reveals a barrel-shaped chest with bilateral scattered wheezes. His abdomen is distended and his liver edge is palpated 4 cm below the right costal margin. You note pitting edema and dilated, tortuous, superficial veins over the bilateral lower extremities. Manual pressure on the abdomen causes persistent distention of the jugular veins. The patient's serum sodium level is 135 mEq/L and his creatinine concentration is 1.2 mg/dl. An abnormality of which of the following is most likely to explain his edema?

39) A 60-year-old male presents to the emergency room with the chief complaint of progressive exertional dyspnea and fatigue. He denies any chest pain, syncope, cough, or edema. He suffered an acute anterior wall myocardial infarction one month ago. Chest auscultation reveals bilateral crackles in his lower chest. Cardiac auscultation reveals a pansystolic murmur at the apex with radiation to the axilla. ECG shows previously present unchanged Q waves and a persistent ST segment elevation in the anterior leads. Based on these findings, what is the most likely underlying cause of his symptoms?

40) A 68-year-old white female presents to the ER complaining of sudden onset chest pain associated with two episodes of vomiting. She has hypertension for which she takes atenolol and hydrochlorothiazide. Her pulse is 60/min, blood pressure is 80/50 mmHg and respirations are 14/min. Examination shows elevated jugular venous pressure and a positive Kussmaul's sign. Her lungs are clear to auscultation. Her EKG shows 2 mm ST segment elevation in leads II, III and aVF and 1 mm ST segment depression in leads I and aVL. Which of the following is the most likely cause of this patient's hypotension?

41) A 53-year-old man presents to your office complaining of weakness and exertional dyspnea over the last week. He denies chest pain and palpitations. He has no other past medical history. His father died of a myocardial infarction at age 55. On exam, his heart rate is 100/min and blood pressure is 90/60 mmHg. Internal jugular venous pulsation is observed 7 cm above the sternal angle. Lungs are clear to auscultation. Heart sounds are muffled. Which of the following is the most likely cause of this patient's complaints?

42) A 34-year-old man rushes into the ER complaining of severe substernal chest pain that began abruptly 30 minutes ago. He says that he also feels as though his heart 'is racing,' but denies any shortness of breath, cough or fever. He has never experienced pain like this before. His past medical history is significant for an appendectomy one year ago. The patient reports that his father died at age 64 due to "some heart problem" and his mother died of ovarian cancer. On physical examination, the patient is agitated and sweating profusely. His pulse is 110/min, blood pressure is160/100 mmHg, and respirations are 14/min. Physical examination is normal except for dilated pupils and a small amount of 42) A 34-year-old man rushes into the ER complaining of severe substernal chest pain that began abruptly 30 minutes ago. He says that he also feels as though his heart 'is racing,' but denies any shortness of breath, cough or fever. He has never experienced pain like this before. His past medical history is significant for an appendectomy one year ago. The patient reports that his father died at age 64 due to "some heart problem" and his mother died of ovarian cancer. On physical examination, the patient is agitated and sweating profusely. His pulse is 110/min, blood pressure is160/100 mmHg, and respirations are 14/min. Physical examination is normal except for dilated pupils and a small amount of 441 blood at the external nares. EKG shows ST elevations in leads v1-v4. What is the most likely explanation for his symptoms?

43) A 50-year-old white male comes into your office for a routine check-up. He has no present complaints. His past medical history is significant for hypertension controlled with a low-dose thiazide diuretic. His family history reveals non-fatal myocardial infarction in his father at the age of 47. The patient does not smoke or consume alcohol. His blood pressure is 130/75 mmHg and his heart rate is 70/min. His previous records show that his HDL level is persistently low in spite of acceptable total cholesterol and LDL levels. You prescribe niacin to raise HDL level. The patient returns in a week complaining of intensive generalized pruritis and flushing. What is the most probable cause of the patient's complaint?

44) A 63-year-old male is admitted for sudden onset severe chest pain. His ECG reveals ST elevation in leads V2-V6. He is treated with thrombolytic therapy, heparin, aspirin, metoprolol, morphine, and nitrates. A coronary angiogram performed after thrombolytic therapy reveals 50% obstruction of the left anterior descending artery. On the third day of hospitalization, the patient suddenly develops severe shortness of breath at rest and hypotension. Examination reveals a soft S1, an apical pansystolic murmur radiating to the axilla, and bibasilar crackles. His temperature is 37.8°C (100°F), blood pressure is 92/58 mmHg, heart rate is 102/min, and respirations are 31/min. An echocardiogram performed on the second hospital day reveals an akinetic region of the anterior wall. What is the most likely explanation for this patient's deterioration?

45) A 34-year-old female presents to your office complaining of pressure-like, substernal chest pain that has been affecting her recently when she plays active sports. Resting consistently alleviates the pain. She denies any associated nausea, vomiting, diaphoresis, dyspnea, palpitations or syncope. Family history is non-contributory. On physical examination, her pulse is 79/min and blood pressure is 130/70 mmHg. Cardiac auscultation reveals a high-pitched 3/6 systolic murmur best heard at the second right intercostal space. The lungs are clear to auscultation. Chest x-ray shows a normal sized heart and clear lung fields. What is the most likely cause of this patient's chest pain?

46) A 48-year-old Caucasian male presents to your office complaining of progressive exertional dyspnea. It has become especially bothersome over the past two months. Presently, he becomes short of breath after climbing one flight of stairs. He denies any significant problems in the past. He is not taking any medications and he denies smoking or drinking alcohol. His temperature is 37.2°C (98.9°F), pulse is 78/min, blood pressure is 130/75 mmHg and respirations are 14/min. Chest examination reveals a harsh systolic murmur that is best heard at the right second intercostal space with radiation along the carotid arteries. An S4 is heard at the apex. Based on these findings, what is the most likely cause of this patient's symptoms?

47) A 45-year-old man presents to the emergency department because of dyspnea, fatigue, poor appetite and weight gain over the past several weeks. He says that about four weeks ago he began to develop worsening shortness of breath with exertion and more recently has been waking at night with breathlessness. He also notes that it is sometimes difficult for him to open his eyes in the morning due to facial edema. He has no significant past medical history and he takes no medications. On physical examination, his blood pressure is 200/120 mmHg and his heart rate is 100/min. You note generalized bodily edema and distention of his jugular veins while he is sitting upright. On lung auscultation you hear bibasilar rales. Urinalysis shows trace protein, no nitrites, trace leukocyte esterase, 50+ red blood cells and occasional neutrophils. Which of the following is the most likely cause of this patient's edema?

48) A 14-year-old African American male collapses and dies while playing basketball at a school tournament. He has no known past medical history. Which of the following is the most likely underlying disease in this patient?

49) A 46-year-old man complains of exertional dyspnea and dry cough. He also describes occasional episodes of a suffocating night-time cough that is relieved only when he stands up. His medical history is significant for a myocardial infarction six months ago. His current medications are metoprolol, aspirin and simvastatin. He does not use tobacco but drinks alcohol on social occasions. His father died of a stroke and his mother suffers from diabetes mellitus. His blood pressure is 150/100 mmHg and his heart rate is 60/min. Chest examination reveals bibasilar rales. His cardiac apex is palpated in the sixth intercostal space. The liver span is 12 cm. Bilateral pitting leg edema is also present. Which of the following most likely contributes to his edema?

50) A 54-year-old man with a 20-year history of chronic obstructive lung disease has a heave that is palpable at the lower left sternal border at the third, fourth, and fifth intercostal spaces. Which of the following best explains the etiology of the heave?

51) A 55-year-old man presents to the ED with chest pain and shortness of breath. His BP is 170/80 mmHg, HR is 89 beats per minute, and oxygen saturation is 90% on room air. Physical examination reveals crackles midway up both lung fields and a new holosystolic murmur that is loudest at the apex and radiates to the left axilla. ECG reveals ST elevations in the inferior leads. Chest radiograph shows pulmonary edema with a normal sized cardiac silhouette. Which of the following is the most likely cause of the cardiac murmur?

52) A 66-year-old retired carpenter presents with chronic shortness of breath upon exertion. He has smoked one pack of cigarettes per day for the past 5 years and drinks alcohol regularly. Physical examination reveals a displaced point of maximal impulse and hepatosplenomegaly. His medications include pantoprazole for gastroesophageal reflux and sertraline for depression. Echocardiogram reveals an ejection fraction of 30% and dilated left and right ventricles. Laboratory tests show: Na+: 129 mEq/L, K+: 5.2 mEq/L, Cl−: 101 mEq/L, Blood urea nitrogen: 45 mg/dL, Creatinine: 1.3 mg/dL, Glucose: 134 mg/dL, Aspartate aminotransferase: 220 U/L, Alanine aminotransferase: 140 U/L, Alkaline phosphatase: 280 U/L. Which of the following is the most likely cause of his cardiac findings?

53) A 47-year-old woman who is 2 weeks post triple bypass surgery presents to the emergency department with a chief complaint of sudden onset, sharp chest pain for several hours. She is fatigued and short of breath. On physical examination she has distended neck veins that grow more distended on inspiration. Muffled heart sounds are heard. Her temperature is 37.0°C (98.6°F), pulse is 133/min, blood pressure is 70/50 mmHg, respiratory rate is 30/ min, and oxygen saturation is 100% on room air. An echocardiogram shows a large pericardial effusion and chamber collapse; therefore, pericardiocentesis is performed. Although a large amount of blood is aspirated, the patient’s clinical picture acutely worsens. Her pain level increases substantially; pulse is 150/min, blood pressure is 60/41 mm Hg, respiratory rate is 30/ min, and oxygen saturation is 100%. Repeat echocardiography shows an even larger pericardial effusion with chamber collapse. Which complication of pericardiocentesis is most likely in this patient?

54) A 29-year-old man is brought to the ED by EMS for a syncopal episode that occurred during a basketball game. A friend states that the patient just dropped to the ground shortly after scoring a basket on a fast break. On examination, you note a prominent systolic ejection murmur along the left sternal border and at the apex. An ECG reveals left ventricular hypertrophy, left atrial enlargement, and septal Q waves. You suspect the diagnosis and ask the patient to perform the Valsalva maneuver while you auscultate his heart. Which of the following is most likely to occur to the intensity of the murmur with this maneuver?

55) A 32-year-old man is brought to the emergency department by paramedics after being found wandering downtown, apparently delirious and agitated. During transport to the hospital the patient becomes diaphoretic and tremulous and has a blood pressure to 163/100 mmHg, pulse of 102/min, and temperature of 39°C (102.2°F). On examination the patient has dilated pupils and ulcerations of his nasal septum mucosa with the residue of a white powder along the nasal alae in addition to his tachycardia, hypertension, hyperthermia, and agitation. Which of the following is the reason why nonselective β-blockers should be avoided in this patient?

56) A 72-year-old woman had a pacemaker inserted 4 years ago for symptomatic bradycardia because of AV nodal disease. She is clinically feeling well and her ECG shows normal sinus rhythm at a rate of 68/min but no pacemaker spikes. Her pacemaker only functions when the ventricular rate falls below a pre-set interval. Which of the following best describes her pacemaker function?

57) A 47-year-old man is found to have edema, ascites, and hepatosplenomegaly. The examination of his neck veins reveals elevated venous pressure with a deep y descent. Heart size on x-ray is normal. Which of the following etiologies is not a possible explanation for this syndrome?

58) 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?

61) 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?

62) While palpating the pulse of a patient, you note that the pulse wave has two peaks. You auscultate the heart and are certain that there is only one heartbeat for each two pulse waves. Which of the following best describes this finding?

63) A 62-year-old man with a prosthetic aortic valve develops fevers and malaise. His valve was replaced 5 years ago because of aortic stenosis from a bicuspid valve. He has a systolic ejection murmur but no other abnormalities on examination. Blood cultures are most likely to grow which of the following?

64) A 28-year-old man with a history of intravenous drug abuse presents to the emergency department with a 2-day history of fever, chills, and shortness of breath. On physical examination the patient has a new heart murmur, small retinal hemorrhages, and subungual petechiae. Which of the following is the most likely causative organism?

65) A 91-year-old woman presents to the emergency department with a chief complaint of shortness of breath over the past 2 days. She has a history of hypertension and coronary artery bypass surgery 25 years earlier. Her blood pressure is 178/92 mmHg and she has jugular venous distension, hepatomegaly, and 3+ lower extremity edema. ECG is remarkable for left ventricular hypertrophy, no ST-segment elevations or depressions, no Q waves, and no T wave abnormalities. Echocardiogram reveals an ejection fraction of 60% and left atrial dilatation. There is universal left ventricular thickening. No valvular regurgitation or stenosis was noted. Which of the following underlying conditions is the most likely cause of this patient’s symptoms?

67) A 47-year-old woman has new-onset transient right arm weakness and word finding difficulty symptoms lasting 3 hours. She is also experiencing exertional dyspnea, and had a syncopal event 1 month ago. Her echocardiogram reveals a cardiac tumor in the left atrium, it is pendunculated and attached to the endocardium. Which of the following is the most likely cause of this lesion?

68) A 23-year-old man develops sharp left-sided chest pain, fever, and a friction rub heard at the lower left sternal border, unaffected by respiration. The pain is also aggevated by lying down and relieved by sitting up. He is otherwise well with no other symptoms and the remaining physical examination is normal. Which of the following is the most likely cause for his symptoms?

69) A 17-year-old girl develops exertional dyspnea, but has no cough, sputum, or wheezing symptoms. On examination, she has a fixed splitting of her second heart sound and a 3/6 systolic ejection murmur heard best over the left sternal border. An echocardiogram confirms the condition. Which of the following is the best physiologic explanation for her condition?

70) A 65-year-old man comes to the office and complains of pain and a rash with blisters over the left side of his chest. He has experienced pain over the area for the past 2 days. This morning, he noticed blisters while changing his shirt. He also complains of malaise and headache. His pulse is 82/min, blood pressure is 140/90 mmHg, respirations are 14/min and temperature is 36.8°C (98.4°F). Physical examination reveals grouped, tense vesicles arranged in a band along the left side of his chest. Which of the following is the most likely etiology of his condition?

71) A 65-year-old man comes to the office with a six-month history of a non-healing ulcer on his right forearm. Physical examination demonstrates a scaling plaque with central ulceration and 1.5 cm diameter. The biopsy shows polygonal cells with atypical nuclei at all levels of the epidermis with zones of keratinization. What is the single most important risk factor for this condition?

72) A 35-year-old Caucasian male with aplastic anemia undergoes bone marrow transplantation. The donor is an HLA-matched sibling. Two weeks after the procedure, he develops a maculopapular pruritic rash that is predominantly found on his face, hands, and feet. He also complains of diarrhea. The stool is positive for occult blood. Liver function tests are abnormal. Which of the following is the most likely pathophysiologic mechanism of this patient's condition?

73) A 36-year-old male AIDS patient comes in due to a painful red eye. He complains of pain, discharge and redness in his left eye for the past 10 days. On physical examination, you notice redness in his left eye as well as multiple skin lesions on his face, left eyelid, inner thighs, penis and pubis. The lesions are painless, pale, shiny, dome-shaped papules with a central umbilication measuring 2-5mm in diameter. These lesions were not present on his previous visit. His CD4 count thirty days ago was 100/uL. What is the most likely etiology of this patient's skin lesions?

74) A 25-year-old woman comes to the office for the evaluation of pale patches of skin around her mouth. She noticed these lesions a few months ago, but they have become more prominent now. There is no itching, burning, or numbness over the patches. Her vital signs are stable. On examination, you notice pale white patches symmetrically distributed around her mouth. The borders of these macules are well-circumscribed and hyperpigmented. Similar lesions are also found over the areola of her breasts. She denies any history of trauma or infection. Which of the following best explains the pathology of her condition?

75) 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?

76) A 30-year-old female presents with a circumferential pruritic rash over her right wrist. The rash has been present for the last two days, and she denies ever having a similar rash before. She bought a new bracelet two weeks ago, and has been wearing it on her right forearm since. Which of the following metals in jewellery is most likely to cause such symptoms?

78) A 9-year-old boy is brought to the office by his mother because of itching, burning and oozing skin lesions on both of his legs. The boy appears tanned. When asked if he had been spending time outdoors, he replies with great excitement that he just returned yesterday from a camping trip in the woods with his dad. Physical examination of both lower limbs reveals vesicles with erythema arranged in a linear fashion. Weepy and crusted lesions and edema are also present. What type of reaction is responsible for this boy's lesions?

79) A 15-year-old male is brought to the emergency department due to sudden-onset difficulty breathing for the past 45 minutes. He also complains of nausea, colicky abdominal pain and a swollen face. He has been suffering from bronchitis for the past 4 days, and his condition had been improving. His mother says that he had a similar episode when he had a tooth extraction 2 year ago. On examination, there is an edematous swelling of his face including the lips, hands, arms, legs, and genitals. His pulse is 82/min, blood pressure is 120/80 mmHg, respirations are 18/min and temperature is 36.8°C (98.4°F). Which of the following best explains the pathological process of his condition?

80) A 32-year-old Asian female presents to the office with a mole on her foot that recently became darker. She has always had skin that is very sensitive to sunlight. She is unable to tan, and has had several sunburns when she did not use sunscreens. Her past medical history is insignificant. Her mother had 'a kind of skin cancer.' Physical examination reveals a dark mole with irregular borders on the left foot. Which of the following is the strongest risk factor for malignancy in this patient?

81) A 25-year-old complains of fever and myalgias for 5 days and now has developed a macular rash over his palms and soles with some petechial lesions. The patient recently returned from a summer camping trip in Tennessee. Which of the following is the most likely cause of the rash?

82) A 53-year-old female presents to the clinic with an erythematous lesion on the dorsum of her right hand. The lesion has been present for the past 7 months and has not responded to corticosteroid treatment. She is concerned because the lesion occasionally bleeds and has grown in size during the past few months. On physical examination you notice an 11-mm erythematous plaque with a small central ulceration. The skin is also indurated with mild crusting on the surface. Which of the following is true about this process?

84) A 34-year-old homosexual male with a history of HIV presents to the clinic complaining of a wheezing and multiple violaceous plaques and nodules on his trunk and extremities. Physical examination of the oral mucosa reveals similar findings on his palate, gingiva, and tongue. Chest x-ray is also significant for pulmonary infiltrates. What is the most likely pathogenesis of this process?

85) A 40-year-old female presents with altered mental status and confusion. Last year, she was diagnosed with rheumatoid arthritis, for which she is currently using indomethacin and methotrexate. Her temperature is 37°C (98.6°F), pulse is 75/min, blood pressure is 110/70 mmHg, and respirations are 15/min. She is disoriented and irritable. Mucus membranes are moist. There is no jugular venous distention. Lungs are clear to auscultation. Abdomen is soft, nontender and not distended. There is no peripheral edema. Serum chemistry reveals: Sodium 122 mEq/L, Potassium 3.7 mEq/L, Bicarbonate 22 mEq/L, Blood glucose 90 mg/dL, BUN 9.0 mg/dL, Uric acid 3.0 mg/dL. Serum osmolality is 265mOsm/kg, while urine osmolality is 500 mOsm/kg. What is the most likely cause of this patient's hyponatremia?

86) A 25-year-old woman comes into the office with a three-month history of weight loss, irritability, insomnia, and palpitations. Her past medical history is insignificant. She is not taking any current medications and denies drug abuse. Her blood pressure is 155/70 mmHg and heart rate is 110/min. Physical examination reveals lid retraction, fine tremor of the hands, and increased neck circumference. The most probable cause of hypertension in this patient is?

87) A 55-year-old Caucasian male presents to the office for a routine check-up. He has no present complaints. His past medical history is significant for a long history of hypertension. He does not smoke or consume alcohol. His current medications are enalapril and hydrochlorothiazide. His blood pressure is 140/90 mmHg and heart rate is 80/min. Physical examination reveals a moderately overweight man (BMI = 27 kg/m2) with a waist circumference of 41 inches. The laboratory studies show: Fasting blood glucose 112 mg/dl, Total cholesterol 220 mg/dl, LDL cholesterol 140 mg/dl, Triglycerides 240 mg/dl. Which of the following is the most important pathogenic factor for this patient's condition?

88) A 38-year-old Mexican male presents to the emergency department with a history of weight loss, fever, cough with sputum, nausea, abdominal pain, and postural dizziness for the last three months. Adrenal insufficiency is suspected, and cosyntropin (synthetic ACTH) stimulation test is performed. The rise of serum cortisol following an injection of cosyntropin is grossly subnormal. CT scan of the abdomen shows calcification of both adrenal glands. What is the most likely cause of this patient's adrenocortical insufficiency?

89) A 60-year-old Caucasian male is brought to the emergency department by his daughter due to a 2-day history of confusion and lethargy. According to his daughter, he had been complaining of fatigue, anorexia, polyuria and constipation for the last several weeks. He smokes two packs of cigarettes daily, and consumes alcohol occasionally. His blood pressure is 130/90 mmHg and heart rate is 90/min. Physical examination reveals a somnolent patient who is not oriented in time. His lab values are: Serum Na 140 mEq/L, Serum K 4.0 mEq/L, Serum chloride 100 mEq/L, Serum bicarbonate 22 mEq/L, Serum creatinine 1.6 mg/dl, Serum calcium 13.4 mg/dL, Serum phosphorus 2.2 mg/dL, Blood glucose 100 mg/dL, Alkaline phosphatase 80 U/L. Chest x-ray demonstrates a right middle lobe mass and perihilar adenopathy. What is the most probable cause of this patient's symptoms?

90) A 51-year-old female comes to the office for a routine visit. She is apparently healthy and does not have any complaints. Physical examination reveals a thyroid nodule. She is surprised to hear about the nodule and asks, "How often does this happen? What could have caused this?" Which of the following is the most common cause of thyroid nodules?

91) A 46-year-old male presents with swelling of his face that is especially prominent in the periorbital area. He also complains of bilateral ankle swelling. He denies shortness of breath, fever and discoloration of urine. He is a non-smoker and non-alcoholic. His past medical history is not significant. He is currently not taking any medication. His pulse is 78/min, blood pressure is 130/70mmHg, respirations are 14/min and temperature is 37.1°C (99.0°F). Examination shows bilateral pitting ankle edema. Auscultation reveals clear lungs, normal heart sounds, and no murmurs. Dipstick urinalysis is positive for protein. 24-hour urine collection shows proteinuria of 4.6 g/day. Lab studies show: Total serum calcium 7.5 mg/dL, Albumin 2.2 g/dL, Phosphorus 3.5 mg/dL, Magnesium 2.2 mg/dL, Creatinine 0.8 mg/dL. Which of the following is the most likely cause of his low serum calcium level?

92) A 36-year-old white male is brought to the emergency department because of dyspnea, tachypnea, crampy pain and paresthesias in his extremities. He gives an unclear history about how he "rapidly ascended to a height of 10,000 feet” His pulse is 70/min, blood pressure is 120/80 mmHg, temperature is 36.7°C (98.5°F) and respirations are 24/min. The significant physical finding on examination is carpopedal spasm. At this point, the suspected diagnosis is acute respiratory alkalosis secondary to hyperventilation. Which of the following is true regarding this patient's serum calcium level?

93) A 23-year-old Caucasian male with muscular weakness, vomiting and abdominal pain is brought to the emergency department. He had a minor respiratory illness 2 days ago. His past medical history is significant for diabetes mellitus, type 1. He admits skipping his insulin shots yesterday and today because he had no appetite. His temperature is 37.8°C (100°F), blood pressure is 110/70 mmHg, pulse is 110/min, and respirations are 27/min. His oral mucosa is dry. The laboratory values are: Serum sodium 132 mEq/L, Serum potassium 5.4 mEq/L, Serum calcium 8.9 mEq/L, Serum chloride 96 mEq/L, Serum bicarbonate 12 mEq/L, Blood glucose 470 mg/dl,BUN 19 mg/dL, Serum creatinine 1.1 mg/dL. Which of the following is the most likely cause of the increased potassium level in this patient?

94) A 29-year-old white female presents to the emergency department with nausea, vomiting, severe generalized abdominal pain, and hypotension. She is subsequently admitted to the intensive care unit. Her past medical history is significant for hypothyroidism secondary to Hashimoto's thyroiditis, for which she has been taking levothyroxine. She denies smoking cigarettes, drinking alcohol, and using any intravenous drugs. Her mother also has hypothyroidism. Her blood pressure is 70/50 mmHg, heart rate is 110/min, temperature is 98.4°F (37.0°C) and respiratory rate is 24/min. Physical examination reveals dry and pigmented mucous membranes. The skin creases also show increased pigmentation. Lab studies show: Serum chemistry: Serum Na 130 mEq/L, Serum K 6.1 mEq/L, Chloride 96 mEq/L, Bicarbonate 18 mEq/L, BUN 33 mg/dL, Serum creatinine 1.3 mg/dL, Blood glucose 56 mg/dL. CBC: Hemoglobin 10.8 g/L, Platelets 300,000/mm3, Leukocyte count 6,500/mm3, Neutrophils 70%, Eosinophils 10%, Lymphocytes 20%. The random serum cortisol level is 3.2 mcg/dL (normal=5 to 25 mcg/dL), and ACTH level is 142 pg/mL (normal= 9 to 52 pg/mL). What is the most likely involved pathophysiologic mechanism of this patient's disorder?

95) A 40-year-old male patient presents with a thyroid nodule. His other complaints are episodes of palpitations, anxiety and sweating. He denies heat intolerance. His weight and appetite are normal. He has a family history of thyroid cancer. His pulse is 80/min, and blood pressure is 160/100 mmHg. Examination of the neck shows a 4-cm, hard, non-tender thyroid nodule. The urinalysis, serum sodium, serum potassium, serum calcium, serum creatinine, serum PTH, TSH, T3 and T 4 levels, and the EKG are all normal. The serum calcitonin level is elevated. The urinary levels of metanephrine and norepinephrine are increased as well. FNA biopsy of the thyroid nodule shows malignant cells. Genetic testing shows a mutation in the RETproto oncogene. Which of the following abnormalities is also present in most patients suffering from this disorder?

96) A 45-year-old female presents complaining of constipation and abdominal pain for the past two weeks. She also complains of urinary frequency and constant thirst. Her past medical history is significant for obesity. She tells you that she has been trying very hard to lose weight, and over the past six months has even attempted various fad diets. She assures you that she supplements her intake with numerous over-the-counter vitamins and minerals. She has managed to lose 20 lbs during this time. Her medical history is also significant for atrial fibrillation for the past 4 years, for which she takes diltiazem. On physical examination, her temperature is 36.8°C (98.2°F), blood pressure is 120/70 mmHg, pulse is 90/min, and respirations are 13/min. Her mucous membranes are dry, and her abdomen is soft and non-tender without rebound or rigidity. Bowel sounds are present. Urinalysis is within normal limits. Which of the following is most likely responsible for her current symptoms?

97) A 19-year-old football linebacker is admitted following a motor vehicle accident. He had an extensive cerebral bleed, which led to a deep coma. He also has fractures of the C4 vertebra, pelvis, and right femur. Following admission, he is intubated and central lines are placed. During the next few days, he develops acute renal failure due to rhabdomyolysis. While he is recovering from acute renal failure, he is found to have a serum calcium level of 12.1 mg/dL. Other investigations are: Serum albumin 3.0 g/dL, Serum creatinine 2.8 mg/dL, Serum phosphorus 3.8 mg/dL, Blood glucose 108 mg/dL, PTH 9 pg/mL, PTHrP undetectable, 1, 25-dihyroxy vitamin D 19 pg/mL (normal 20-60 kg/mL). What is the most likely cause of this patient's hypercalcemia?

98) A 28-year-old avid mountain climber and his friend are vacationing in Andes, South America. During their mountain climbing expedition, the pair somehow manages to get lost. It has been over 16 hours since their food supply ran out. Their glycogen stores are becoming depleted, and their bodies are beginning to utilize the process of gluconeogenesis. Which of the following intermediates is alanine being converted into during this process?

99) A 60-year-old Caucasian male presents to your office complaining of decreased hearing on the right side. He also feels that something is wrong with his head because his hat size had increased over the last two years. His past medical history is significant for hypertension and peptic ulcer disease. His current medications are hydrochlorothiazide and enalapril. He also takes ibuprofen for occasional headaches, and ranitidine for infrequent episodes of heartburn. Lab tests showed increased alkaline phosphatase levels. Which of the following is the most likely mechanism underlying this patient's condition?

100) A 60-year-old man presents to his primary care physician for routine medical care. He has no complaints, takes no medications, and has a family history of DM. Examination is unremarkable. A screening laboratory test reveals a fasting blood glucose level of 152 mg/dL. One week later the test is repeated and a value of 144 mg/dL is obtained. Which of the following is the most likely cause of these findings?

102) A 28-year-old woman presents to her gynecologist for her annual examination. She mentions that she and her husband have been trying to conceive for 9 months without success and that her menstrual cycles have become irregular. Her gynecologist suggests that she and her husband continue to try to conceive and that the woman return in 3 months for some laboratory studies if she still has not become pregnant. In the interim, a routine visit to the ophthalmologist reveals bitemporal hemianopsia. Which of the following is the most likely cause of this woman’s infertility?

103) A 50-year-old obese female is taking oral hypoglycemic agents. While being treated for an upper respiratory infection, she develops lethargy and is brought to the emergency room. Neurological examination is nonfocal; she does not have neck rigidity. Laboratory results are as follows: Na: 134 mEq/L, K: 4.0 mEq/L, HCO3: 25 mEq/L, Glucose: 900 mg/dL, BUN: 84 mg/dL, Creatinine: 3.0 mg/dL, HgA1c: 6.8%, BP: 120/80 mmHg lying down, 105/65 mmHg sitting. Which of the following is the most likely cause of this patient’s coma?

104) 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?

105) A 52-year-old African-American woman with type 2 diabetes mellitus (DM) presents to her physician’s office and states that she has been feeling lousy in the morning. She notes that she reliably checks her blood glucose levels, and is frustrated at the fact that she often has a blood sugar level in the 120s at night, followed by a level in the 170s to 180s the following morning. The patient’s primary care physician increased her nightly dose of neutral protamine Hagedorn insulin 1 month ago, but her morning glucose levels have only become more elevated. She has recently begun to limit her carbohydrate intake at night, with no effect. This patient’s morning hyperglycemia might most likely be alleviated by which of the following?

106) A 26-year-old G1P0 woman at 12 weeks gestation presents to her obstetrician for her first visit. Her pregnancy thus far has been notable only for some mild nausea and vomiting that lasted throughout her first trimester. She reports feeling overly tired lately and very weak. Her past medical history is significant for pernicious anemia. On physical examination she is an anxious-appearing, thin woman. Her blood pressure is 130/85 mmHg, heart rate is 115/ min, and respiratory rate is 18/min. Fetal heart tones are present at 135/min. The uterine fundus is at 12 cm. The woman has a diffuse, non- tender goiter, a resting tremor, and poor global muscle strength. Which is the most likely mechanism underlying this woman’s condition?

107) A 60-year-old woman recently diagnosed with type 2 DM complains of daily headaches and double vision that have gradually worsened over the previous month. An MRI shows a large pituitary adenoma. Which of the following is most likely being secreted by this tumor?

108) A 45-year-old Asian male complains of a progressively worsening sore throat and difficulty swallowing for the past 24 hours. You notice that his voice is muffled and he is drooling. He also has a harsh shrill associated with respiration. His temperature is 39.3°C (103°F), blood pressure is 120/80 mmHg, pulse is 106/min, and respiratory rate is 22/min. On examination, a few cervical lymph nodes are palpable and there is tenderness to palpation over his larynx. Which of the following are the two most common organisms that cause this condition?

109) A 65-year-old female complains of difficulty eating over the last two days. She states that food drops out of her mouth. She has also been having some discharge in her left ear recently. She denies any sore throat, nasal discharge, chest pain, cough, or difficulty breathing. Her past medical history is significant for type 2 diabetes mellitus, hypertension, and hyperlipidemia. She has been poorly complaint with follow-up appointments. Her temperature is 38.8°C (101.7°F), pulse is 96/min, blood pressure is 140/90 mmHg, and respirations are 18/min. Examination of the left ear canal shows granulations. There is facial asymmetry, and the angle of the mouth on the left is deviated downward. Which of the following is the most likely causative organism for this patient's condition?

110) A 62-year-old male comes to your office for a routine follow-up appointment. He has smoked one pack of cigarettes per day for the past 30 years and adamantly refuses to quit. He also drinks six to ten beers each weekend. His past medical history is significant for type 2 diabetes mellitus and hypertension. His last hemoglobinA1c was 8.3%. He is overweight with a current BMI of 27.5 kg/m2. While examining him, you notice a whitish patch over the anterior floor of his mouth. The lesion appears to have a granular texture and is not removed by scraping with a tongue depressor. Which of the following is most likely cause of his oral lesion?

111) A 51 -year-old obese male presents to your office complaining of difficulty swallowing solids but not liquids. His medical history is significant for GERD. Six months ago he was diagnosed with Barrett's esophagus. He reports that three months after the diagnosis of Barrett's esophagus, his heartburn resolved. Barium swallow now reveals an area of symmetric, circumferential narrowing affecting the distal esophagus. Which of the following best explains this finding?

112) A 23-year-old man comes to the physician because of a two-month history of loose stools, decreased appetite, and weight loss. He has no history of medical problems. He takes no medications. His temperature is 36.7°C (98°F), blood pressure is 120/76 mmHg, pulse is 90/min, and respirations are 16/min. Laboratory studies show: Hemoglobin 11.2 g/dL, MCV 80 fl, Leukocyte count 9,500/cmm, Segmented Neutrophils 65%, Bands 3%, Eosinophils 1%, Basophils 0%, Lymphocytes 25%, Monocytes 6%, Platelets 550,000/cmm, ESR 50 mm/hr, Serum sodium 145 mEq/L, Serum potassium 4.0 mEq/L. Test of the stool for occult blood is positive. Which of the following is the most likely type of diarrhea in this patient?

113) 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?

114) A 12-year-old girl comes to the physician for chronic weight loss and fatigue. She has a history of bulky, floating, foul-smelling stools, flatulence and meteorism. She also has bone pain and easy bruising. Laboratory studies show anemia with serum iron: 25 mg/dl , ferritin: 25 mg/dl and serum total iron binding capacity 600 mg/dl (normal 300-360 mg/dL); PT is 16 sec. Physical examination shows loss of subcutaneous fat, pallor, hyperkeratosis and abdominal distention; bowel sounds are increased. Which of the following is most likely associated with this patient's condition?

115) A 44-year-old male who has had an extensive small bowel resection for Crohn's disease has been on total parenteral nutrition for two years. He presented to the hospital with epigastric and right upper quadrant pain. He has been taking azathioprine. His vital signs are within normal limits. Physical examination shows mild right upper quadrant tenderness. An ultrasonogram shows several gallstones; an ultrasonogram performed two years ago did not demonstrate gall stones. Which of the following is the most likely cause of his gallstones?

116) A 35-year-old Caucasian male presents to the emergency department with two episodes of bloody vomiting which occurred one-half hour ago. He has a history of migraines. For the past two days, he has been having severe headaches and has taken 20 tablets of aspirin without relief. He then resorted to heavy drinking and forgot about the pain. He drinks alcohol "occasionally" and has been smoking 1 pack of cigarettes daily for the past 18 years. Which of the following is the most likely explanation for this patient's hematemesis?

117) A 29-year-old male with a 6-year history of HIV infection presents with chronic, severe diarrhea associated with malaise, nausea, anorexia and abdominal cramps. His last CD4 count was 80cells/mm3. A modified acid-fast stain of a stool specimen shows 4-6 mm oocysts. Which of the following is the most likely microorganism responsible for this condition?

118) A 45-year-old Caucasian male presents with a 2-year history of progressive heartburn which is most severe while supine. Over-the-counter antacids have not relieved his symptoms. Endoscopy shows a hiatal hernia. The patient is reluctant to accept any treatment. Which of the following is he at risk for if his condition is left untreated?

119) A 45-year-old male comes to the physician with a 6-month history of periodic abdominal pain. He tried several over-the-counter medications including H2 blockers and proton pump inhibitors with moderate success. Workup, including an upper GI series and endoscopy, showed multiple duodenal ulcers and a single jejunal ulcer. Test of the stool for occult blood is positive. Test of the stool for fat is positive. Which of the following is the best explanation for this patient's impaired fat absorption?

120) A 58-year-old man presents with a one-year history of diarrhea. The stools are watery and accompanied by abdominal cramps. He denies any fever, blood per rectum, or foul-smelling stools. He has also experienced frequent episodes of dizziness, flushing, wheezing, and a feeling of warmth. He has taken herbal medicines, which failed to relieve his symptoms. He is depressed about his illness, and feels hopeless about diagnosis and treatment. He appears ill. Auscultation of the chest shows a 2/6 systolic murmur over the left lower sternal border. Abdominal examination shows hepatomegaly 3cm below the right costal margin, mild shifting dullness, and no abdominal tenderness. Laboratory studies show: Hb 13.0gm/dl, MCV 90fl, WBC 6,100/cmm, Platelets 210,000/cmm, AST101 U/L, ALT 99 U/L, Alkaline phosphatase 400 mg/dl. This patient is at risk of developing a deficiency of which vitamin or mineral?

121) A 65-year-old Caucasian male presents to your office with a several month history of difficulty swallowing. He has noticed a right-sided neck mass which increases in size while drinking fluids. His past medical history is significant for hypertension, gastroesophageal reflux disease, and osteoarthritis of his right knee. His current medications include hydrochlorothiazide, ranitidine, and occasional naproxene. You order a barium examination of the esophagus to visualize the abnormality. Which of the following is the most important pathogenetic factor in the development of this patient's problem?

122) A 20-year-old male university student presents with a one-month history of 4 to 6 loose watery bowel movements per day with occasional tenesmus, urgency, and abdominal cramps. He also describes a two-week history of intermittent bright red blood per rectum. His appetite and energy levels are excellent and his weight is stable. He is otherwise healthy and takes no medications. His family history is unremarkable. He has not recently used antibiotics nor has he traveled outside the country. He does not use tobacco, alcohol or drugs. Sigmoidoscopy demonstrates mild erythema and rectal biopsy confirms acute mucosal inflammation. Which of the following is a potential complication of this condition requiring regular surveillance?

123) A 46-year -old alcoholic man comes to the emergency department because of several episodes of vomiting. The last episode of emesis contained blood. Five hours ago, he had a fatty meal and several alcoholic drinks. Two days ago, he had an upper GI tract endoscopy and abdominal ultrasound for the evaluation of dyspepsia. The endoscopy was unremarkable, and the ultrasound showed a hyperechogenic enlarged liver and stones in the gallbladder. His temperature is 36.6°C (97.9°F), blood pressure is 120/70 mm Hg, pulse is 95/min, and respirations are 15/min. Laboratory studies show: Hb 12.8 g/dl, WBC 5,400/cmm, BUN 26 mg/dl, Creatinine 1.1 mg/dl, AST 100 U/L, ALT 45 U/L, Bilirubin 0.7 mg/dl. Nasogastric suction shows normal stomach contents mixed with bright red blood. The rectal examination shows no melena. Which of the following is the most likely explanation for this patient's bloody vomiting?

124) A 53-year-old woman presents to your office with right-sided abdominal pain that started two days ago. She describes the pain as constant and burning in nature. There is no associated nausea, vomiting or diarrhea. The patient reports taking over-the-counter antacids and ibuprofen, which brought no relief. Her medical history is significant for breast cancer diagnosed one year ago, for which she underwent a modified radical mastectomy and is receiving chemotherapy, the last course of which was completed two months ago. On physical examination, her temperature is 36.7°C (98°F), blood pressure is 120/70 mm Hg, pulse is 80/min, and respirations are 16/min. Her lung fields are clear to auscultation and her abdomen is soft and non-distended. The liver span is 10 cm and the spleen is not palpable. Lightly touching the skin to the right of the umbilicus elicits intense pain. In one week the patient is most likely to develop:

125) A 20-year-old Caucasian male presents with lower abdominal pain for the past few hours. The pain first started around the umbilicus, but then shifted to the right lower abdominal area. He has had one episode of vomiting. Physical examination shows tenderness at McBurney's point. CT scan of the abdomen confirms the diagnosis of acute appendicitis. Which of the following explains the pathophysiology of the shifting of pain from the peri-umbilical area to the right lower quadrant in acute appendicitis?

126) A husband and wife present to the ED with 1 day of subjective fever, vomiting, watery diarrhea, and abdominal cramps. They were at a restaurant a day before for dinner and both ate the seafood special, which consisted of raw shellfish. In the ED, they are both tachycardic with temperatures of 99.8°F and 99.6°F for him and her, respectively. Which of the following is responsible for the majority of acute episodes of diarrhea?

127) A 21-year-old woman presents to the ED complaining of diarrhea, abdominal cramps, fever, anorexia, and weight loss for 3 days. Her BP is 127/75 mm Hg, HR is 91 beats per minute, and temperature is 100.8°F. Her abdomen is soft and nontender without rebound or guarding. WBC is 9200/μL, β-hCG is negative, urinalysis is unremarkable, and stool is guaiac positive. She tells you that she has had this similar presentation four times over the past 2 months. Which of the following extraintestinal manifestations is associated with Crohn disease but not ulcerative colitis?

128) A 67-year-old woman is currently postoperative day 8 after an emergent laparoscopic cholecystectomy for acute cholecystitis. On postoperative day 2 she spiked a temperature of 40°C (101.4°F) and began to complain of some shortness of breath. X-ray of the chest revealed right lower lobe pneumonia, and the patient was started on clindamycin. Today she is experiencing multiple episodes of foul-smelling, watery diarrhea that is green tinged but non-bloody. She also complains of lower abdominal cramping. Her temperature is 37.8°C (100°F), pulse is 90/min, respiratory rate is 15/min, and blood pressure is 110/70 mm Hg. Which of the following is the most likely explanation for these findings?

129) 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?

130) A 77-year-old woman is brought to the emergency room because of nonspecific abdominal discomfort. She has no anorexia, fever, chills, or weight loss. Her abdomen is soft and non-tender on physical examination. Abdominal x-rays show lots of stool in the colon, but no free air or air-fluid levels. The amylase is 150 U/L (25–125U/L), and the rest of her biochemistry and complete blood count are normal. Which of the following conditions can cause a false positive elevation in the serum amylase?

131) A 76-year-old woman with a history of congestive heart failure, coronary artery disease, and an “irregular heart beat” is brought to the ED by her family. She has been complaining of increasing abdominal pain over the past several days. She denies nausea or vomiting and bowel movements remain unchanged. Vitals are HR of 114 beats per minute, BP 110/75 mm Hg, and temperature 98°F. On cardiac examination, her HR is irregularly irregular with no murmur detected. The abdomen is soft, nontender, and nondistended. The stool is heme-positive. This patient is at high risk for which of the following conditions?

132) A 78-year-old man with a history of atherosclerotic heart disease and congestive heart failure presents with increasing abdominal pain. The pain began suddenly a day ago and has progressively worsened since then. He denies nausea, vomiting, and diarrhea, but states that he had black tarry stool this morning. He denies any history of prior episodes of similar pain. Vitals are BP 120/65 mm Hg, HR 105 beats per minute, and temperature 99°F. The patient is at high risk for which of the following conditions?

133) A 29-year-old man with acquired immune deficiency syndrome (AIDS) comes to the emergency department because of progressively increasing abdominal discomfort. Examination shows voluntary guarding in the upper abdomen. His biochemistry is normal except for an elevated amylase at 370 U/L (25–125 U/L). Which of the following infections can trigger this disorder in AIDS patients?

135) A 33-year-old woman develops mild epigastric abdominal pain with nausea and vomiting of 2 days duration. Her abdomen is tender on palpation in the epigastric region, and the remaining examination is normal. Her white count is 13,000/mL, and amylase is 300 U/L (25–125 U/L). Which of the following is the most common predisposing factor for this disorder?

136) A 54-year-old man complains of burning epigastric pain that usually improves after a meal, and is occasionally relieved with antacids. On examination, he appears well and besides some epigastric tenderness on palpation, the rest of the examination is normal. Upper endoscopy confirms a duodenal ulcer. Which of the following statements concerning PUD is most likely correct?

137) A 60-year-old man with no past medical history undergoes upper endoscopy and biopsy for an upset stomach that is worsened by eating. He is found to have inflammation predominantly in the antrum of the stomach. Which of the following is the most likely etiology of this condition?

138) A 23-year-old woman presents to the ED complaining of pain with urination. She has no other complaints. Her symptoms started 3 week ago. During this time, she has been to the clinic twice, with negative urine cultures each time. Her condition has not improved with antibiotic therapy with sulfonamides or quinolones. Physical examination is normal. Wet mount showed epithelial cells. Which of the following organisms is most likely responsible for the patient’s symptoms?

141) 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?

142) 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?

143) A 43-year-old man feels vaguely unwell. Physical examination is unremarkable except for evidence of scleral icterus. The skin appears normal. Which of the following is the most likely explanation for why early jaundice is visible in the eyes but not the skin?

144) A 56-year-old woman becomes the chief financial officer of a large company and, several months thereafter, develops upper abdominal pain that she ascribes to stress. She takes an over-the-counter antacid with temporary benefit. She uses no other medications. One night she awakens with nausea and vomits a large volume of coffee grounds-like material; she becomes weak and diaphoretic. Upon hospitalization, she is found to have an actively bleeding duodenal ulcer. Which of the following statements is true?

145) A 50-year-old man wants to talk to you about something, "absolutely confidential". After you assure him, he admits, "He is unable to get an erection and just can't have sex." He wants to figure it out quickly because "he simply can't live like this." He has never been diagnosed with diabetes and denies other complaints. He has a 2 pack/day history of smoking for 30 years. On examination, his BP: 158/90mm of Hg; Temperature: 37.1°C (98.8°F); RR 14/min; PR 82/min. There is upper body obesity, rounded face, increased fat around the neck, and thinning of arms and legs. You find his skin to be bruised, fragile and thin. Laboratory reveals the following results. Serum: Glucose 186 mg/dl, Sodium 142 mEq/L, Potassium 2.5 mEq/L, Bicarbonate 38 mEq/L. Chest X ray shows a large mass in left bronchus. What is the most likely cause of patient's condition?

146) A 66-year old female has been your patient for the last 8 years. She was diagnosed with colorectal carcinoma 2 years ago, and eventually underwent an endoscopic resection. Since then, she has been healthy, and has been coming to the office regularly for follow-up visits. She is very grateful, and has stated many times that she owes her life to you. You are currently a co-investigator of a retrospective observational study of patients with colon cancer, and you believe that including her medical information will be extremely beneficial. What course of action must you take so that you can include this patient's data in your study?

147) A 65-year-old woman comes to the office for a health maintenance visit. She has been your patient for the last 15 years. When you ask how she has been, she replies with, "Well, I'm very health-conscious now. I read all the health magazines regularly, and exercise for 30 minutes daily. I eat a lot of garlic to control my cholesterol, and drink cranberry juice to keep my kidneys strong. I don't smoke, but I drink alcohol during social events. I've been compliant with regular screening colonoscopies, mammograms, and pap smears. Doc, since my mother died from ovarian cancer, do you think I can have an abdominal ultrasound every 6 months, plus any additional necessary tests, so that any cancer can be detected early?" What is the best response to this patient's concerns?

148) A 22-year-old African-American man presents to the ER with fever, jaundice, abdominal pain, and dark urine. His heart rate is 100/min and blood pressure is 100/60 mmHg. Peripheral blood smear reveals bite cells and red blood cell inclusions seen after crystal violet staining. The patient most likely suffers from which of the following conditions?

149) A 34-year-old male is brought to the emergency department with altered mental status. His girlfriend reports that he has had fever and cough for the past two days. His past medical history is significant for abdominal trauma two years ago that required splenectomy and left-sided nephrectomy. On physical examination, his temperature is 39° C (102.2°F), blood pressure is 80/50 mm Hg, pulse is 110/min, and respirations are 32/min. Gram-positive cocci are cultured from his blood. Which of the following is most likely impaired in this patient?

150) A 43-year-old man presents to your office with low energy and increased fatigability. He also complains of daytime sleepiness and occasional headaches. He drinks two to three glasses of wine daily but does not smoke. He sleeps in a separate room from his wife because she finds his constant snoring annoying. On physical examination, his blood pressure is 160/100 mmHg and his heart rate is 80/min. His BMI is 31.5 kg/m2. His abdomen is soft and non-tender. The liver span is 10 cm and the spleen is not palpable. Laboratory findings are: Hematocrit 60%, WBC count 9,000/mm3, Platelets 190,000/mm3. Which of the following is most likely responsible for this patient's increased hematocrit?

151) A 6-year-old African-American child is brought in by his father for complaints of easy fatigability and pallor. These symptoms occurred after the son was treated with "some medication" for a recent diarrhea. Physical examination is normal except for pallor and multiple petechiae. Laboratory values are as follows: Hb 8.0 g/dL, WBC 12,000/cmm, Platelets 50,000/cmm, Blood glucose 118 mg/dL, Serum Na 135 mEq/L, Serum K 5.3 mEq/L, Chloride 110 mEq/L, Bicarbonate 18 mEq/L, BUN 38 mg/dL, Serum creatinine 2.5 mg/dL, Total bilirubin 3 mg/dL, Direct bilirubin 0.5 mg/dL, PT 12 seconds, APTT 30 seconds, LDH 900 IU/L, Reticulocyte count 6%. A peripheral blood smear reveals giant platelets and multiple schistocytes. What is the most likely underlying pathophysiology for this boy's pallor?

153) A 79-year-old woman presents to your office complaining of an intermittent skin rash over the last several months. She denies fever, headache, and recent weight loss. Her past medical history is significant for diet-controlled diabetes and right knee osteoarthritis treated with acetaminophen. Physical examination reveals several dark purple ecchymotic areas over the dorsum of both arms. Her abdomen is soft and non-tender. The liver span is 8 cm and the spleen is not palpable. Laboratory studies reveal: Hematocrit 47%, WBC count 5,800/mm3, Platelet count 220,000/mm3, Serum creatinine 0.8 mg/dL\, Fibrinogen 350 mg/dL, Prothrombin time 10 sec, INR 1.0, Partial thromboplastin time 25 sec. Which of the following is the most likely cause of this patient's complaint?

154) A 42-year-old woman is evaluated for chronic abdominal pain and fatigue. Her pain is epigastric, crampy, and sometimes awakens her from sleep. She denies any recent weight loss, nausea, or vomiting. Her diet consists mainly of fruits and vegetables. She also complains of a "strange appetite" for paper and ice that she has never had before. Upper gastrointestinal endoscopy reveals an ulcer located on the anterior wall of the duodenal bulb. Her unusual appetite is most directly related to:

155) A 22-year-old female presents to the emergency room with a nosebleed. A quick review of her records reveals that she presented with the same problem yesterday, at which time the bleeding was stopped with prolonged local pressure. On review of systems, the patient also reports easy bruising for the past several months. On physical examination, her heart and lungs appear normal. The liver span is 8 cm and the spleen is not palpable. There are scattered ecchymoses over her arms and legs. Laboratory findings include the following: Hematocrit 45%, Platelet count 9,000/mm3, Leukocyte count 5,500/mm3, Neutrophils 56%, Eosinophils 1%, Lymphocytes 33%, Monocytes 10%, Fibrinogen 250 mg/dL, Prothrombin time 13 sec. Which of the following is the most likely cause of this patient's condition?

156) A 66-year-old female comes for removal of a lipoma from her elbow. She wants the swelling out because it looks ugly when she wears sleeveless tops. Her only complaints are general malaise and fatigue for the past 8 months, which she attributes to her "being alone all the time." Her vital signs are within normal limits. Physical examination reveals mild pallor and both cervical and supraclavicular lymphadenopathy. Her preoperative blood count reveals the following: Hemoglobin 10.0 g/dL, Hematocrit 32%, Platelets 126,000/cmm, WBC 31,600/cmm. Leukocyte distribution: Segmented neutrophils 18%, Lymphocytes 77%, Bands 4%, Monocytes 1%. The pathologist reports the presence of "leukocytes that have undergone partial breakdown during preparation of a stained smear or tissue section, because of their greater fragility." Lymph node biopsy confirms the diagnosis. What is the correct statement about the above patient?

157) A 17-year-old male presents to clinic for routine check-up. He is a long distance runner and has beenachieving outstanding results recently. He is very proud of his athletic achievements, remarking that his effort "pays off." He does not smoke or consume alcohol. His family history is significant for diabetes mellitus in his mother and skin cancer in his father. Chest examination is normal. His liver span is 8 cm and his spleen is not palpable. His current laboratory findings include: Hematocrit 59%, WBC count 7,500/mm3, Platelet count 170,000/mm3, ESR 15 mm/hr. Which of the following is the most likely explanation for the high hematocrit in this patient?

158) A 65-year-old Caucasian male had undergone cardiac catheterization followed by aortic valve replacement for severe aortic stenosis and coronary artery bypass grafting for three-vessel disease. His postoperative course was complicated by atrial fibrillation and a urinary tract infection. His other medical problems include hypertension, diabetes, and hypercholesterolemia. He is also receiving heparin, ciprofloxacin, and amiodarone. On postoperative day five, he developed prolonged bleeding from the venipuncture site. His labs show: Hb 11.5 g/dL, MCV88 fl, Platelet count 50,000/cmm, Leukocyte count 7,500/cmm, Segmented neutrophils 68%, Bands 1%, Eosinophils 1%, Lymphocytes 24%, Monocytes 6%, Prothrombin time 12 sec (INR=1.0), Partial thromboplastin time 65 sec. His preoperative labs were unremarkable. What is the most likely cause of these findings in this patient?

159) A 62-year-old woman presents complaining of recurrent cough productive of yellow sputum. She was seen several weeks ago for similar complaints and was effectively treated with a course of azithromycin. Today she expresses frustration that she seems to keep getting sick with the same infection. On review of systems, the patient also reports recent-onset back pain for which she has been taking acetaminophen. Her past medical history is otherwise insignificant. She has never smoked cigarettes, and drinks alcohol only on rare social occasions. Physical examination reveals conjunctival pallor, a few scattered rales in the lungs bilaterally, and tenderness over the lumbar vertebrae. Laboratory analyses reveal: Hemoglobin 8.4 g/dL, Leukocyte count 5,500/mm3, Blood urea nitrogen 34 mg/dL, Creatinine 2.0 mg/dL, Calcium 10.9 mg/dL, Albumin 3.8 g/dL, Total protein 9.5 g/dL. This patient is at increased risk for recurrent infections because of which of the following abnormalities?

160) A 47-year-old man presents to your office complaining of occasional daytime headaches, dizziness and nausea. He has no significant past medical history. He works as a traffic controller in an underground parking lot. He does not smoke cigarettes, and consumes alcohol only on weekends. He is sexually active in a monogamous relationship with his wife and uses condoms for contraception. His cardiac exam is unremarkable. His abdomen is soft and non-tender. The liver span is 8 cm and the spleen is not palpable. Laboratory findings are: Hematocrit 59%, WBC count 7,000/mm3, Platelets 200,000/mm3. Which of the following is most likely responsible for this patient's increased hematocrit?

161) A 57-year-old Caucasian female is diagnosed with deep venous thrombosis of the right leg that was confirmed with Doppler ultrasonography. She was diagnosed with pneumonia and empyema one week earlier, and treated with chest tube, antibiotics and bed rest. On her 6th day of anticoagulation therapy, she develops right hemiparesis and slight motor aphasia. The laboratory findings are: Red blood cells 4.3 million/mm3, Hemoglobin 14.00 g/dL, White blood cells 7,000/cmm, Platelets 50,000/cmm, APTT 60 sec (N < 25-40 sec), Fibrin degradation products negative. The emergency head CT scan does not reveal blood in the subarachnoid space or brain parenchyma. Which of the following is the most probable cause of this patient's condition?

162) A 25-year-old African American woman presents with a photo distributed skin rash and arthralgias. She is found to have low-range proteinuria and abnormal urinary sediment. Renal biopsy findings are consistent with focal proliferative glomerulonephritis. Her complete blood count shows: Erythrocyte count 3.2 mln/mm3, Platelets 60,000/mm3, Leukocyte count 2,500/mm3. Which of the following is the most likely cause of these hematologic findings?

163) A 45-year-old Asian man presents to your office complaining of easy fatigability. He denies abdominal pain, distention, nausea, vomiting, or significant weight loss. His past medical history includes a gastrectomy for a non-healing gastric ulcer. He is not currently taking any medications. He quit smoking several years ago and does not use alcohol or illicit drugs. His vital signs are within normal limits. Physical examination reveals a shiny tongue and pale palmar creases. No lymphadenopathy, hepatomegaly, or splenomegaly is present. His blood hemoglobin level is 7.5 mg/dL and W8C count is 3,800/mm3. Stool tests for occult blood are repeatedly negative. This patient's condition involves which of the following pathophysiologic mechanisms?

164) A 23-year-old African American man is treated with an antibiotic for an uncomplicated urinary tract infection. Several days later, he presents to your office saying that his initial symptoms have improved but his urine now appears dark. He has no significant past medical history and does not use tobacco, alcohol, or illicit drugs. His temperature is 36.8°C (98.2°F), pulse is 88/min, respirations are 14/min, and blood pressure is 130/76 mmHg. Physical examination is within normal limits. The urine sample stains positive with Prussian blue and the sediment microscopy is unrevealing. What is the mechanism behind the cell damage responsible for this patient's current complaint?

165) A 6-year-old Caucasian boy is hospitalized for acute sinusitis that was accompanied with intensive nasal bleeding. Past medical history is significant for recurrent pulmonary infections and several hospitalizations for parenteral antibiotic therapy. The sweat chloride test is positive. The blood tests reveal a prothrombin time (PT) of 20 seconds. Which of the following coagulation factors is most likely to be deficient in this patient?

166) A 27-year-old man presents to the emergency department with unremitting nose bleeding. He reports having a similar bleeding episode one year ago that was stopped in the ER. He works as a computer programmer and has a sedentary lifestyle. He drinks alcohol on social occasions but does not smoke or use illicit substances. On physical examination, there are several ruby-colored papules on his lips that blanch partially with pressure. Digital clubbing is also present. His abdomen is soft and non-tender. The liver span is 8 cm and the spleen is not palpable. Laboratory findings are: Hematocrit 60%, WBC count 8,000/mm3, Platelets 180,000/mm3. Which of the following is most likely responsible for this patient's increased hematocrit?

167) A 14-year-old boy is brought by his mother because she noticed a change in his voice. He has been having frequent nosebleeds for the last month, and feels that his "left nose" is always congested. There is no history of trauma. He admits to using marijuana, in the absence of his mother. He is otherwise well, and does not take any medications. He actively participates in the school basketball tournaments. Physical examination reveals an intact nasal septum with a visible mass at the back of the left nostril. CT scan reveals an erosion of the adjacent bone. What is the most likely reason of this patient's nosebleeds?

168) A 34-year-old male who recently emigrated from Asia comes to the clinic and complains of a two-month history of exertional shortness of breath and easy fatigability. He has been taking isoniazid and rifampin for his tuberculosis, which was diagnosed four months ago. Due to his religious beliefs, he completely turned into a vegetarian for the last year. Physical examination reveals severe pallor. Peripheral smear shows macrocytosis with hypersegmented polymorphonuclear neutrophils. His WBC and platelet counts are within normal limits. This patient's most likely problem is due to which of the following?

169) A 12-year-old boy is brought to the emergency department because of severe pain near his left knee. He has sickle cell disease, and has been hospitalized previously for sickle cell crisis. Vital signs are notable for mild fever. Examination of the left lower extremity reveals a normal knee joint with marked tenderness and swelling over the proximal tibia. Labs show leukocytosis and elevated ESR. He is subsequently diagnosed with osteomyelitis. Which of the following organisms is the most likely cause of his condition?

170) A 23-year-old male comes to ER with five day history of diarrhea and abdominal pain. Initially, the diarrhea was watery occurring five-six times per day but yesterday he noticed blood in the stool which prompted his visit to ER. He describes his abdominal pain as colicky and severe. He also complains of nausea and decreased appetite but he has had no vomiting. His past medical history is insignificant and never had similar symptoms. He is not sexually active and he denies any illicit drug use. He has no history of recent travel. His father had colon cancer and his uncle died of liver cirrhosis. His temperature is 36.6°C (98.0°F), blood pressure is 123/82 mmHg and heart rate is 102/min. On examination, he has prominent periumbilical and right lower quadrant tenderness but no guarding or rebound. Rectal examination reveals brownish stool mixed with blood. Which of the following is the most likely diagnosis?

171) A 55-year-old Asian man with mitral stenosis secondary to rheumatic heart disease undergoes dental surgery for caries. Postoperatively, he does well and is discharged home. Two weeks later, he presents with fever, chills, fatigue, and feels "sick." Four out of four blood culture bottles are positive for gram-positive cocci. An echocardiogram is performed and shows mitral valve vegetations. Which of the following is the most likely causative organism of this patient's condition?

172) A 16-year-old Asian boy presents with a two-day history of fever, malaise, and painful enlargement of his parotid glands. He has no significant past medical history. He was born in India, and has not received any childhood vaccinations. He recently returned from a one-week vacation in India. His vital signs are stable, except for a mild fever. Examination shows bilateral parotid enlargement. The rest of the examination is unremarkable. Which of the following organs is most likely to be affected by this patient's illness?

173) A 29-year-old man returns home to Colorado after a diving trip to Honduras in Central America. He was gone for 6 days. The day he returns, he starts to develop diarrhea, abdominal cramping, and nausea. There is no mucus and blood in the stool. He has no other medical problems and does not take medications. He does not use tobacco, alcohol or drugs. His temperature is 37.2°C (98.9°F), blood pressure is 120/74 mm Hg, pulse is 80/min, and respirations are 15/min. There is no lymphadenopathy. Chest is clear to auscultation. Abdomen is soft and non-tender. There is no organomegaly. Bowel sounds are increased. Stool is negative for leukocytes and fecal occult blood. Which of the following is the most likely pathogen responsible for his symptoms?