Context: A 17-year-old previously healthy, athletic male suddenly falls unconscious while playing soccer. His athletic trainer comes to his aid and notes that he is pulseless. He begins performing CPR on the patient until the ambulance arrives but the teenager is pronounced dead when the paramedics arrived. Upon investigation of his primary care physician's office notes, it was found that the child had a recognized murmur that was ruled to be "benign." Which of the following conditions would have increased the intensity of the murmur?

Question: Which of the following conditions would have increased the intensity of the murmur?

Answer: Valsalva


Context: A 45-year-old male presents to the emergency room complaining of severe nausea and vomiting. He returned from a business trip to Nigeria five days ago. Since then, he has developed progressively worsening fevers, headache, nausea, and vomiting. He has lost his appetite and cannot hold down food or water. He did not receive any vaccinations before traveling. His medical history is notable for alcohol abuse and peptic ulcer disease for which he takes omeprazole regularly. His temperature is 103.0°F (39.4°C), blood pressure is 100/70 mmHg, pulse is 128/min, and respirations are 22/min. Physical examination reveals scleral icterus, hepatomegaly, and tenderness to palpation in the right and left upper quadrants. While in the examination room, he vomits up dark vomitus. The patient is admitted and started on multiple anti-protozoal and anti-bacterial medications. Serology studies are pending; however, the patient dies soon after admission. The virus that likely gave rise to this patient’s condition is part of which of the following families?

Question: The virus that likely gave rise to this patient’s condition is part of which of the following families?

Answer: Flavivirus


Context: A 14-year-old girl is brought to the physician for evaluation of her short stature. She was born at term, and her birth length was normal. She has not yet attained menarche. Her mother is 162 cm (5 ft 4 in) tall and her father is 177 cm (5 ft 10 in) tall. She is at the 3rd percentile for height and 40th percentile for weight. Vital signs are within normal limits. Breast and pubic hair development are Tanner stage 2. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next step in diagnosis?

Question: Which of the following is the most appropriate next step in diagnosis?

Answer: X-ray of the hand and wrist


Context: A 59-year-old African-American man presents with dyspnea on exertion and bilateral lower leg edema. The patient had a myocardial infarction 2 years ago, in which he developed chronic heart failure. Also, he has type 2 diabetes mellitus. His medications include bisoprolol 20 mg, lisinopril 40 mg, and metformin 2000 mg daily. The vital signs at presentation include: blood pressure is 135/70 mm Hg, heart rate is 81/min, respiratory rate is 13/min, and temperature is 36.6℃ (97.9℉). The physical examination is significant for bilateral lower leg pitting edema. The cardiac auscultation demonstrated an S3 and a systolic murmur best heard at the apex. Which of the following adjustments should be made to the patient’s treatment plan?

Question: Which of the following adjustments should be made to the patient’s treatment plan?

Answer: Add hydralazine/isosorbide dinitrate


Context: An investigator is studying the resting rate of oxygen consumption in the lower limbs of individuals with peripheral vascular disease. The rate of blood flow in a study subject's femoral vessels is measured using Doppler ultrasonography, and blood samples from the femoral vein and femoral artery are obtained. The blood samples are irradiated and centrifuged, after which the erythrocyte fractions from each sample are hemolyzed using 10% saline. Compared to the femoral vein, which of the following findings would be expected in the hemolysate from the femoral artery?

Question: Compared to the femoral vein, which of the following findings would be expected in the hemolysate from the femoral artery?

Answer: Lower chloride concentration


Context: A 5-year-old boy is brought to a pediatrician by his parents for evaluation of learning difficulties in school. He has short stature, a flat face, low-set ears, a large tongue, and a single line on the palm. He was born to his parents after 20 years of marriage. You ordered karyotyping which will likely reveal which of the following?

Question: You ordered karyotyping which will likely reveal which of the following?

Answer: 47, XY, +21


Context: A 28-year-old woman presents for her annual physical examination. She describes a painless lump in her left breast detected during breast self-examination two weeks ago. She has no previous history of breast lumps and considers herself to be generally healthy. She takes no medication and does not smoke tobacco or drink alcohol. The patient has no personal or family history of breast cancer. Her vitals are normal. Physical examination reveals a firm, 1 to 2 cm mass in the lateral aspect of her left breast. However, no associated skin changes, nipple discharge, or retraction are found. No axillary adenopathy is present. What is the most appropriate next step in the workup of this patient?

Question: What is the most appropriate next step in the workup of this patient?

Answer: Perform an ultrasound


Context:
A 10-year-old boy with trisomy 21 arrives for his annual check-up with his pediatrician. His parents explain that over the past week, he has been increasingly withdrawn and lethargic. On examination, lymph nodes appear enlarged around the left side of his neck; otherwise, there are no remarkable findings. The pediatrician orders some routine blood work.
These are the results of his complete blood count:
WBC 30.4 K/μL
RBC 1.6 M/μL
Hemoglobin 5.1 g/dL
Hematocrit 15%
MCV 71 fL
MCH 19.5 pg
MCHC 28 g/dL
Platelets 270 K/μL
Differential:
Neutrophils 4%
Lymphocytes 94%
Monocytes 2%
Peripheral smear demonstrates evidence of immature cells and the case is referred to hematopathology. On flow cytometry, the cells are found to be CALLA (CD10) negative. Which of the following diseases is most associated with these clinical and cytological findings?

Question: Which of the following diseases is most associated with these clinical and cytological findings?

Answer: Precursor T-cell acute lymphoblastic leukemia/lymphoma


Context: In large neurons the nucleus can be found a large distance away from the terminal end of its axon. The body has a complex system of intracellular transporters that are able to carry essential proteins from the nucleus to the distal edge of the cell and back. Which of the following proteins are essential for this function?

Question: Which of the following proteins are essential for this function?

Answer: Dynein, Kinesin


Context: A group of bariatric surgeons are investigating a novel surgically-placed tube that drains a portion of the stomach following each meal. They are interested in studying its efficacy in facilitating weight loss in obese adults with BMIs > 40 kg/m2 who have failed to lose weight through non-surgical options. After randomizing 150 patients to undergoing the surgical tube procedure and 150 patients to non-surgical weight loss options (e.g., diet, exercise), the surgeons found that, on average, participants in the surgical treatment group lost 15% of their total body weight in comparison to 4% in the non-surgical group. Which of the following statistical tests is an appropriate initial test to evaluate if this difference in weight loss between the two groups is statistically significant?

Question: Which of the following statistical tests is an appropriate initial test to evaluate if this difference in weight loss between the two groups is statistically significant?

Answer: Unpaired two-sample t-test


Context: A 55-year-old Caucasian male presents for a routine colonoscopy. A polyp is found in the patient's transverse colon and is found to be cancerous on histological evaluation. Upon examination, it is found that these cancerous cells have decreased MHC class I expression on their surface. Which immune system cell is most capable of killing these tumor cells?

Question: Which immune system cell is most capable of killing these tumor cells?

Answer: Natural killer cells


Context: A 68-year-old man comes to the physician because of headache, fatigue, and nonproductive cough for 1 week. He appears pale. Pulmonary examination shows no abnormalities. Laboratory studies show a hemoglobin concentration of 9.5 g/dL and an elevated serum lactate dehydrogenase concentration. A peripheral blood smear shows normal red blood cells that are clumped together. Results of cold agglutinin titer testing show a 4-fold elevation above normal. An x-ray of the chest shows diffuse, patchy infiltrates bilaterally. Treatment is begun with an antibiotic that is also used to promote gut motility. Which of the following is the primary mechanism of action of this drug?

Question: Which of the following is the primary mechanism of action of this drug?

Answer: Inhibition of peptide translocation at the 50S ribosomal subunit


Context: A 48-year-old man comes to the emergency department because of a 1-hour history of heavy nasal bleeding. He drinks half a bottle of sherry daily. His pulse is 112/min, and blood pressure is 92/54 mm Hg. Physical examination shows scattered ecchymoses across the extremities and oozing from a venipuncture site. Laboratory studies show a prothrombin time of 28 seconds and a partial thromboplastin time of 36 seconds. Impaired function of which of the following proteins is the most likely cause of this patient's hemorrhage?

Question: Impaired function of which of the following proteins is the most likely cause of this patient's hemorrhage?

Answer: Gamma-glutamyl carboxylase


Context: A 68-year-old male smoker dies suddenly in a car accident. He had smoked 2 packs per day for 40 years. His past medical history is notable for a frequent, very productive cough, recurrent respiratory infections and occasional wheezing. He had no other medical problems. At autopsy, which of the following is most likely to be found in this patient?

Question: At autopsy, which of the following is most likely to be found in this patient?

Answer: Increased number and activity of goblet cells


Context: A 62-year-old man is found unconscious in the park on a bench, early in the morning in January. The temperature outside is -4.0°C (25°F). He is barefoot and is wearing nothing more than sweatpants, a tee-shirt, and a light coat. Upon arrival at the emergency department, his vitals include: heart rate 45/min, blood pressure 100/70 mm Hg, and respiratory rate 10/min. His core body temperature is 30.0°C (85.5°F). His feet and palms are covered with clear blisters, the skin is yellow with a waxy appearance, and the tissues are edematous. The patient is unresponsive to auditory stimuli. Which of the following cold-associated injuries does the patient have?

Question: Which of the following cold-associated injuries does the patient have?

Answer: Frostbite


Context: A 16-year-old girl undergoes an emergent appendectomy after presenting to the emergency department with appendicitis. She is given a mixture of nitrous oxide and sevoflurane for induction of anesthesia and intubated for a secure airway during surgery. A few minutes after induction, she is found to have increased end-tidal carbon dioxide and tachycardia. Furthermore, the surgeon notices that her abdomen is extremely rigid before making his incision. Finally, she is found to have hyperkalemia despite having normal serum potassium during preoperative laboratory studies. Defective function of which of the following proteins is most likely responsible for this patient's findings?

Question: Defective function of which of the following proteins is most likely responsible for this patient's findings?

Answer: Ryanodine receptor


Context: An 18-year-old male in his first year of college presents to the emergency room with a fever and a severe headache. He reports having unprotected sex with several partners over the past few weeks. Upon examination, the male demonstrates nuchal rigidity and photophobia. His past medical history is notable for a lack of vaccinations beginning from infancy due to his parents' belief that vaccinations may cause autism. The bacteria causing these symptoms would most likely demonstrate which of the following?

Question: The bacteria causing these symptoms would most likely demonstrate which of the following?

Answer: Positive quellung reaction


Context: A 9-year-old girl is brought to the pediatrician for a wellness checkup. The girl's past medical history is non-contributory, and she has met all her developmental milestones. Her parents were recently called into the office as the girl was found touching the genitals of one of her classmates. She was trying to insert a toy into her classmate's genitals. The girl is asked what has happened and what she thinks is going on but she is too shy to reply to the physician. The girl and her mother recently moved in with a family member. They live in low-income housing subsidized by the government and are currently on food stamps. The mother states that her daughter has been particularly argumentative lately and that they have gotten into arguments in which her daughter screamed at her and locked herself in the bathroom. Which of the following is the most likely diagnosis?

Question: Which of the following is the most likely diagnosis?

Answer: Sexual abuse


Context: A previously healthy 59-year-old man comes to the physician with a 6-month history of worsening headaches, difficulty chewing, and progressive hearing loss. Examination shows a mildly tender, 1-cm, hard swelling over the left maxilla. The remainder of the examination shows no abnormalities. Serum studies show a calcium concentration of 8.5 mg/dL, alkaline phosphatase activity of 112 U/L, and parathyroid hormone concentration of 310 pg/mL. Audiometry shows bilateral mixed conductive and sensorineural hearing loss. Which of the following processes is the most likely cause of this patient's condition?

Question: Which of the following processes is the most likely cause of this patient's condition?

Answer: Increased activity of nuclear factor-κB


Context: A 28-year-old woman, gravida 2, para 1, at 24 weeks gestation comes to the physician for a prenatal visit. She reports dull aching pain and paresthesia over her left hand during the last few weeks. The pain radiates to her shoulder and is worse at night. Her hand feels numb upon waking up in the morning. She has a sister who has multiple sclerosis. Her current medications include iron supplements and a multivitamin. Vital signs are within normal limits. When the wrist is passively held in full flexion, aggravation of paresthesia is perceived immediately. Which of the following is the most likely explanation for this patient's symptoms?

Question: Which of the following is the most likely explanation for this patient's symptoms?

Answer: Median nerve compression


Context: A 62-year-old man comes to the physician because of gradual onset of bilateral ankle swelling over the past month. He also noticed reddish blotches of skin around his ankles. Five weeks ago, he came to the physician with difficulty walking and a resting tremor. He was diagnosed with Parkinson disease and started on medication. He has a history of hypertension and his antihypertensive medications were also adjusted. His temperature is 37.3°C (99.1°F), pulse is 64/min, respirations are 13/min, and blood pressure is 124/74 mm Hg. Physical examination shows bilateral 2+ edema in the ankles. There is purple-red discoloration on the lower legs in a reticular pattern. Neurologic examination shows resting tremor in both hands and bilateral cogwheel rigidity in the elbows. Which of the following pharmacotherapies is the most likely cause of this patient's edema?

Question: Which of the following pharmacotherapies is the most likely cause of this patient's edema?

Answer: Amantadine


Context: A 60-year-old man is brought to the emergency department after a fall. He has been seen by the triage nurse but has not been evaluated by a physician. He is heard yelling down the hallway, requesting to speak to “whoever is in charge.” He refuses to talk to the emergency resident and insists on talking to the attending physician despite being informed that the attending is currently resuscitating a patient who was in a car accident. He says that he deserves better treatment because he has made numerous contributions to the field of medicine. When asked about his work, he mentions that he was a medical device salesman. He is accompanied by his wife, who appears embarrassed. She claims that her husband frequently makes a scene and apologizes for her husband's behavior. On mental status examination, the patient is oriented to person, place, and time. He appears agitated and speaks in short, pressured sentences. There is no disorder of thought process or content. Which of the following is the most likely diagnosis?

Question: Which of the following is the most likely diagnosis?

Answer: Narcissistic personality disorder


Context: A 56-year-old woman presents with fatigue and joint pain in her fingers and wrists for the last 6 months. She says the pain is present in both hands, and her wrists are also swollen. Furthermore, she describes morning stiffness in her joints lasting about 2 hours, which improves with use. She has been taking acetaminophen, which provided minimal relief, but the swelling has gotten progressively worse. She also feels increasingly tired. Her past medical history reveals she has been successfully treated for Helicobacter pylori (H. pylori) related ulcers last year but still takes omeprazole for her mild gastroesophageal reflux. The patient denies any smoking history and stopped drinking when her gastric symptoms started. Which of the following analgesic drugs is the best choice to use in this patient?

Question: Which of the following analgesic drugs is the best choice to use in this patient?

Answer: Celecoxib


Context: A 15-year-old boy is brought to the physician by his parents for evaluation of his “weird” behavior. The parents report that their son tortured their cat to death two weeks ago. Over the past year, he has been accused of stealing a car and setting a fire at his school. He has no history of serious illness. He attends a local high school, and his performance at school is very poor compared to his classmates. He often loses his temper and argues with his teachers. He has smoked one pack of cigarettes daily for 2 years. He does not drink alcohol. His mother has a 10-year history of schizophrenia controlled with medication. On mental status examination, he is oriented to person, place, and time. The pupils are equal and reactive to light. His speech is normal in rate and rhythm, and his thought process is organized. Short- and long-term memory are intact. Attention and concentration are poor. Which of the following is the most likely diagnosis?

Question: Which of the following is the most likely diagnosis?

Answer: Conduct disorder


Context: A 45-year-old homeless man comes to the emergency department because of a 1-week history of a red, itchy rash on his hands. He says the itching is worse at night and often wakes him from sleep. Physical examination shows the findings in the photograph. A topical drug with which of the following mechanisms of action is most likely to be effective?

Question: A topical drug with which of the following mechanisms of action is most likely to be effective?

Answer: Binding to sodium channels


Context: A newborn presents with central cyanosis, nasal flaring, and subcostal retractions following a scheduled cesarean delivery. He was born to a healthy 29-year-old G-1-P-1 mother due to cervical incompetence at 34 weeks gestation; the pregnancy was otherwise uneventful. Appearance, Pulse, Grimace, Activity, and Respiration (APGAR) scores were 6 and 8 at 1 and 5 minutes, respectively and his birth weight was 3,200 g. The umbilical cord had 3 vessels and the placenta was tan-red with all cotyledons intact. Fetal membranes were tan-white and semi-translucent. Currently, the vital signs include: temperature 36.9°C (98.4°F), blood pressure 70/40 mm Hg, pulse 190/min, and respiratory rate 68/min. On auscultation, breath sounds are decreased. Diffuse ground-glass opacifications are identified on chest X-ray. Which of the factors listed below most likely contributed to this infant’s current condition?

Question: Which of the factors listed below most likely contributed to this infant’s current condition?

Answer: Gestational diabetes


Context: A 23-year-old woman presents with a 4-week menstrual delay. She also complains of irritability, increased somnolence, and occasional nausea. She had her first menarche at the age of 13, and her menstrual cycle became regular at the age of 15. She has been sexually active since the age of 20 but has had the same sexual partner since then. They stopped using birth control protection approximately 6 months ago. She does not smoke and consumes alcohol occasionally. Her blood pressure is 120/80 mm Hg, heart rate is 71/min, respiratory rate is 14/min, and temperature is 36.6℃ (98.2℉). Physical examination is significant only for slight breast engorgement and nipple pigmentation. Gynecologic examination reveals cervical softening and cyanosis. Which of the following drugs would be recommended for this patient?

Question: Which of the following drugs would be recommended for this patient?

Answer: Folic acid


Context: An 11-year-old girl presents to the pediatrician with her mother, who is concerned about her sexual development. She mentions that she herself experienced the onset of menses at the age of 10.5 years, while her daughter has still not had a menstrual period. However, she is otherwise a healthy girl with no significant medical problems since birth. On physical examination, her vital signs are stable. Evaluation of breast and pubic hair are Tanner stage 2. He reassures the mother that her daughter’s sexual development is within the normal range for girls and there is nothing to worry about at present. Which is a sign of Tanner stage 2?

Question: Which is a sign of Tanner stage 2?

Answer: Thelarche


Context: A 64-year-old man presents to his primary care physician for follow-up of a severe, unrelenting, productive cough of 2 years duration. The medical history includes type 2 diabetes mellitus, which is well-controlled with insulin. He has a 25-pack-year smoking history and is an active smoker. The blood pressure is 135/88 mm Hg, the pulse is 94/min, the temperature is 36.9°C (98.5°F), and the respiratory rate is 18/min. Bilateral wheezes and crackles are heard on auscultation. A chest X-ray reveals cardiomegaly, increased lung markings, and a flattened diaphragm. Which of the following is most likely in this patient?

Question: Which of the following is most likely in this patient?

Answer: Increased pulmonary arterial resistance


Context: A 62-year-old man comes to the physician because of a 2-month history of an itchy rash and a 7-kg (15-lb) weight loss. Physical examination shows multiple erythematous plaques on the arms, legs, and chest. There are palpable lymph nodes in the axillary and inguinal areas. A biopsy of a skin lesion shows aggregates of neoplastic cells within the epidermis. A peripheral blood smear is most likely to show which of the following findings in this patient?

Question: A peripheral blood smear is most likely to show which of the following findings in this patient?

Answer: CD4+ cells with cerebriform nuclei


Context: A 35-year-old homeless man from New York City comes to the physician with a 2-month history of fever, night sweats, and a cough productive of white sputum. He uses intravenous heroin several times a week. His temperature is 38°C (100.4°F) and respirations are 22/min. Physical examination shows coarse crackles in the left upper posterior lung field. An x-ray of the chest shows a cavitary lesion in the left upper lobe. Which of the following is the most likely source of his pulmonary findings?

Question: Which of the following is the most likely source of his pulmonary findings?

Answer: Reactivation of a latent infection


Context: A 19-year-old woman with a history of bipolar disorder and an unknown cardiac arrhythmia presents with palpitations and chest pain. She admits to taking lithium and procainamide regularly, but she ran out of medication 2 weeks ago and has not been able to get refills. Her family history is significant for bipolar disorder in her mother and maternal aunt. Her vital signs include blood pressure 130/90 mm Hg, pulse 110/min, respiratory rate 18/min. Physical examination is significant for a widely split first heart sound with a holosystolic murmur loudest over the left sternal border. Visible cyanosis is noted in the lips and nailbeds. An electrocardiogram is performed which shows intermittent supraventricular tachyarrhythmia with a right bundle branch block. Her cardiac enzymes are normal. An echocardiogram is performed, which shows evidence of a dilated right atria with portions of the tricuspid valve displaced towards the apex. Which of the following medications was this patient most likely exposed to prenatally?

Question: Which of the following medications was this patient most likely exposed to prenatally?

Answer: Mood stabilizer


Context: A 35-year-old woman presents to the emergency department with severe nausea and diarrhea. One day prior to presentation, she went to a new seafood restaurant known for serving exotic fish. For the past day she experienced nausea, diarrhea, weakness, and a tingling sensation in her extremities. In the emergency department, her temperature is 100.3°F (37.9°C), blood pressure is 95/60 mmHg, pulse is 105/min, and respirations are 20/min. On physical examination, she appears fatigued and has 1+ Achilles and patellar reflexes. Which of the following is the mechanism of action of the compound most likely responsible for this patient's clinical presentation?

Question: Which of the following is the mechanism of action of the compound most likely responsible for this patient's clinical presentation?

Answer: Prevents depolarization of Na+ channels


Context: A previously healthy 6-year-old boy is brought to the physician because he has increased facial and axillary hair. There is no family history of serious illness. He is at 95th percentile for height and weight. Examination shows coarse pubic and axillary hair. The penis and left testicle are enlarged. Serum concentrations of human chorionic gonadotropin and alpha-fetoprotein are within the reference range. Which of the following is the most likely cause of these findings?

Question: Which of the following is the most likely cause of these findings?

Answer: Leydig cell tumor


Context: A newborn boy born vaginally to a healthy 37-year-old G3P1 from a pregnancy complicated by hydramnios fails to pass meconium after 24 hours of life. The vital signs are within normal limits for his age. The abdomen is distended, the anus is patent, and the rectal examination reveals pale mucous with non-pigmented meconium. Based on a barium enema, the boy is diagnosed with sigmoid colonic atresia. Disruption of which structure during fetal development could lead to this anomaly?

Question: Disruption of which structure during fetal development could lead to this anomaly?

Answer: Inferior mesenteric artery


Context: A 20-year-old man visits the clinic for a regular follow-up appointment. Patient says he has been experiencing dry mouth and flushing of his skin for the past few days. He also feels tired and sleepy most of the time. Past medical history is significant for a skin rash a couple weeks ago after eating strawberries, for which he has prescribed a medication that he is still taking. Which of the following is the most likely etiology of this patient’s symptoms?

Question: Which of the following is the most likely etiology of this patient’s symptoms?

Answer: Inhibition of parasympathetic receptors


Context:
A 12-year-old boy is brought in by his mother for a routine checkup. The patient’s mother says he is frequently fatigued and looks pale. She also claims that he has recently become “much quieter” than normal and is no longer interested in playing baseball with his friends. The patient’s mother believes it may just be “growing pains.” The patient has no significant medical history. He is the 90th percentile for height and weight and has been meeting all developmental milestones. The patient is afebrile, and his vital signs are within normal limits. Physical examination reveals several small bruises on the patient’s right arm and on both thighs. Laboratory findings are significant for the following:
Sodium 140 mEq/L
Potassium 4.2 mEq/L
Chloride 101 mEq/L
Bicarbonate 27 mEq/L
BUN 16 mg/dL
Creatinine 1.2 mg/dL
Glucose (fasting) 111 mg/dL
  WBC 3,400/mm3
RBC 4.20 x 106/mm3
Hematocrit 22%
Hemoglobin 7.1 g/dL
Platelet count 109,000/mm3
A peripheral blood smear reveals myeloblasts. Which of the following is the next best step in the management of this patient?

Question: Which of the following is the next best step in the management of this patient?

Answer: Bone marrow biopsy


Context: A 22-year-old man comes to the physician because of a fall associated with a 6-month history of increasing difficulty walking. Over the last year, his friends have also noticed his speech becoming slower. During this period, he also gave up his hobby of playing video games because he has become clumsy with his hands. His father died of esophageal varices at the age of 40 years. The patient does not smoke or drink alcohol. He takes no medications. He appears sad. His temperature is 37°C (98.6°F), pulse is 70/min, and blood pressure is 120/80 mm Hg. He is alert and oriented to person, place, and time. His speech is slurred and monotonous; his gait is unsteady. Examination shows scleral icterus and some drooling. The liver is palpated 2 to 3 cm below the right costal margin, and the spleen is palpated 1 to 2 cm below the left costal margin. Further evaluation of this patient is most likely to show which of the following findings?

Question: Further evaluation of this patient is most likely to show which of the following findings?

Answer: Low serum ceruloplasmin concentration


Context: A young infant is brought to an immunologist because of recurrent infections, which have not resolved despite appropriate medical treatment. On reviewing her medical history, the immunologist notes that the child has had frequent disseminated mycobacterial infections. He suspects a possible immunodeficiency. What is the most likely cause of this patient's immunodeficiency?

Question: What is the most likely cause of this patient's immunodeficiency?

Answer: Interferon-gamma signaling defect


Context: You are counseling a pregnant woman who plans to breast-feed exclusively regarding her newborn's nutritional requirements. The child was born at home and the mother only plans for her newborn to receive vaccinations but no other routine medical care. Which vitamins should be given to the newborn?

Question: Which vitamins should be given to the newborn?

Answer: Vitamin K and Vitamin D


Context: An otherwise healthy 62-year-old woman comes to the physician because of a 3-year history of hearing loss. To test her hearing, the physician performs two tests. First, a vibrating tuning fork is held against the mastoid bone of the patient and then near her ear, to which the patient responds she hears the sound better on both sides when the tuning fork is held near her ear. Next, the physician holds the tuning fork against the bridge of her forehead, to which the patient responds she hears the sound better on the right side than the left. The patient's examination findings are most consistent with which of the following conditions?

Question: The patient's examination findings are most consistent with which of the following conditions?

Answer: Acoustic neuroma on the left


Context: A 50-year-old HIV-positive male presents to the ER with a two-day history of fever and hemoptysis. Chest radiograph shows a fibrocavitary lesion in the right middle lobe. Biopsy of the afflicted area demonstrates septate hyphae that branch at acute angles. Which of the following is the most likely causal organism?

Question: Which of the following is the most likely causal organism?

Answer: Aspergillus fumigatus


Context:
A 34-year-old G3P2 is admitted to the hospital after being physically assaulted  by her husband. She developed severe vaginal bleeding and abdominal pain. She is at 30 weeks gestation. Her previous pregnancies were uncomplicated, as has been the course of the current pregnancy. The vital signs are as follows: blood pressure, 80/50 mmHg; heart rate, 117/min and irregular; respiratory rate, 20/min; and temperature, 36.2℃ (97.1). The fetal heart rate is 103/min. On physical examination, the patient is pale and lethargic. Abdominal palpation reveals severe uterine tenderness and tetanic contractions. The perineum is grossly bloody. There are no vaginal or cervical lesions. There is active  heavy bleeding with blood clots passing through the cervix. An ultrasound shows a retroplacental hematoma with a volume of approximately 400 ml.
Laboratory workup shows the following findings:
Red blood cells count: 3.0 millions/mL
Hb%: 7.2 g/dL
Platelet count: 61,000/mm3
Prothrombin time: 310 seconds (control 20 seconds)
Partial prothrombin time: 420 seconds
Serum fibrinogen: 16 mg/dL
Elevated levels of which of the following laboratory markers is characteristic for this patient’s complication?

Question:
Laboratory workup shows the following findings:
Red blood cells count: 3.0 millions/mL
Hb%: 7.2 g/dL
Platelet count: 61,000/mm3
Prothrombin time: 310 seconds (control 20 seconds)
Partial prothrombin time: 420 seconds
Serum fibrinogen: 16 mg/dL
Elevated levels of which of the following laboratory markers is characteristic for this patient’s complication?

Answer: D-dimer


Context: A 21-year-old male college student is very anxious about having thyroid cancer as he found a lump in his neck a few days ago. He has also had diarrhea and a feeling of warmth on his face for 3 days now. His father and uncle both have been diagnosed with thyroid cancer. The lump is about 1 cm in diameter and is fixed and nontender on palpation. Physical examination is otherwise unremarkable. Ultrasound shows a non-cystic cold nodule that requires fine needle aspiration for diagnosis. Thyroid functions tests are normal, and his calcitonin level is 346 ug/ml. Which of the following genetic mutations would warrant thyroidectomy in this patient?

Question: Which of the following genetic mutations would warrant thyroidectomy in this patient?

Answer: RET gene mutation


Context:
A 78-year-old man presents to his primary care physician for persistent back pain. The patient states that he has had back pain for awhile; however, this past weekend he was helping his son move heavy furniture. Since the move, his symptoms have been more severe. The patient states that the pain is constant and occurs throughout the day. On review of systems, the patient endorses a recent 15 pound weight loss and constipation. His temperature is 99.5°F (37.5°C), blood pressure is 137/79 mmHg, pulse is 90/min, respirations are 15/min, and oxygen saturation is 98% on room air. Cardiovascular exam is notable for a murmur at the right sternal border that radiates to the carotids. Pulmonary exam reveals mild bibasilar crackles. Musculoskeletal exam is notable for mild midline tenderness of the lower thoracic spine and the upper segment of the lumbar spine. No bruising or signs of external trauma are observable on the back. Symptoms are not exacerbated when the patient is lying down and his straight leg is lifted. Strength is 5/5 in the lower and upper extremities. The patient's sensation is intact bilaterally in his lower and upper extremities. Laboratory values are ordered and return as seen below.

Hemoglobin: 11 g/dL
Hematocrit: 34%
Leukocyte count: 10,500/mm^3 with normal differential
Platelet count: 288,000/mm^3

Serum:
Na+: 139 mEq/L
Cl-: 100 mEq/L
K+: 4.3 mEq/L
HCO3-: 25 mEq/L
BUN: 20 mg/dL
Glucose: 99 mg/dL
Creatinine: 1.6 mg/dL
Ca2+: 11.8 mg/dL
AST: 12 U/L
ALT: 12 U/L

Which of the following is the most likely diagnosis?

Question:
Hemoglobin: 11 g/dL
Hematocrit: 34%
Leukocyte count: 10,500/mm^3 with normal differential
Platelet count: 288,000/mm^3

Serum:
Na+: 139 mEq/L
Cl-: 100 mEq/L
K+: 4.3 mEq/L
HCO3-: 25 mEq/L
BUN: 20 mg/dL
Glucose: 99 mg/dL
Creatinine: 1.6 mg/dL
Ca2+: 11.8 mg/dL
AST: 12 U/L
ALT: 12 U/L

Which of the following is the most likely diagnosis?

Answer: Plasma cell dyscrasia


Context: A 4-week-old neonate boy who was born at 27 weeks gestation to a 19-year-old G2P1 mother due to premature rupture of membranes has his hospital stay complicated by chorioamnionitis. He received 2 doses of surfactant and has been weaned from the ventilator to continuous positive airway pressure (CPAP). Over the last 6 hours he has developed abdominal distention and is no longer tolerating his tube feeds. You suspect necrotizing enterocolitis. Which of the following would be diagnostic?

Question: Which of the following would be diagnostic?

Answer: Pneumatosis intestinalis on an abdominal X-ray


Context: A 48-year-old woman with a history of obesity presents with acute onset of diffuse epigastric pain that began a few hours ago and then localized to the right upper quadrant. Further questioning reveals that the pain has been exacerbated by eating but has otherwise been unchanged in nature. Physical exam reveals severe right upper quadrant pain that is accompanied by arrest of respiration with deep palpation of the right upper quadrant. Which of the following symptoms is associated with the most likely etiology of this patient's presentation?

Question: Which of the following symptoms is associated with the most likely etiology of this patient's presentation?

Answer: Pain radiating to the right shoulder


Context: A 25-year-old man was referred to a neurologist for right-hand weakness. He was involved in a motor vehicle accident 2 months ago in which his right hand was injured. On examination, his grip is weak, especially in fingers 2, 4, and 5 and he is unable to adduct these fingers. Which of the following groups of muscles is most likely affected?

Question: Which of the following groups of muscles is most likely affected?

Answer: Palmar interossei muscles


Context: A 14-year-old girl presents with fever, headache, and muscle aches that have lasted for 2 days. She also complains of malaise and pain in her joints. She says she just returned from a camping trip in Delaware. Her past medical history is not significant. The patient denies any recent sick contacts. Her temperature is 38.3°C (101.0°F), pulse is 87/min, respirations are 17/min, and blood pressure is 120/78 mm Hg. On physical examination, there is a 3-inch-diameter, red, erythematous, round rash with central clearing on the right leg (see image). Antibodies against Proteus vulgaris OX-19 are absent. Which of the following is the most likely cause of this patient’s symptoms?

Question: Which of the following is the most likely cause of this patient’s symptoms?

Answer: Borrelia burgdorferi


Context:
A 55-year-old woman visits the clinic after experiencing what she describes as an odd episode of tingling in her fingers and the sensation of smelling sour milk. She denies loss of consciousness, confusion, or incontinence. She also denies a history of head trauma or the ingestion of toxic substances. Past medical history is significant for type 2 diabetes mellitus, which is well controlled with metformin. Her temperature is 36.8°C (98.2°F), the heart rate is 98/min, the respiratory rate is 15/min, the blood pressure is 100/75 mm Hg, and the O2 saturation is 100% on room air. The physical exam, including a full neurologic and cardiac assessment, demonstrates no abnormal findings. Laboratory findings are shown. Brain MRI does not indicate any areas of infarction or hemorrhage. ECG is normal, and EEG is pending.
BUN 15 mg/dL
pCO2 40 mmHg
Creatinine 0.8 mg/dL
Glucose 95 mg/dL
Serum chloride  103 mmol/L
Serum potassium 3.9 mEq/L
Serum sodium 140 mEq/L
Total calcium 2.3 mmol/L
Magnesium 1.7 mEq/L
Phosphate 0.9 mmol/L
Hemoglobin 14 g/dL
Glycosylated hemoglobin 5.5%
Total cholesterol 4 mmol/L
Bicarbonate (HCO3) 19 mmol/L
Urine toxicology screen is negative. What kind of seizure is most likely being described?

Question: What kind of seizure is most likely being described?

Answer: Simple partial


Context: A 29-year-old woman at 38 weeks gestation comes to the emergency room with regular contractions and spontaneous rupture of membranes. She subsequently delivers a 3500g (7lbs 7oz) newborn with ambiguous genitalia by spontaneous vaginal delivery. Her pregnancy and labor was uncomplicated. Examination of the newborn demonstrated no palpable gonads at the inguinal canal or perineum. Karyotype analysis demonstrated 46,XX. What is the best explanation for this patient’s presentation?

Question: What is the best explanation for this patient’s presentation?

Answer: Exposure to excessive androgenic steroids during gestation


Context: A 14-year-old teenager is brought to the physician by her mother who seems extremely concerned that her daughter is unable to sleep at night and has become increasingly irritated and aggressive. She has been noticing changes in her daughter’s behavior recently. She had no idea what was going on until she found pills hidden in her daughter’s room a week ago. Her daughter confessed that she tried these drugs once with her friends and started using them since then. Her mother threw away all the pills and prevented her daughter from seeing her friends. This is when she started to notice her tear often and sweat. She is seeking a quick and effective treatment for her daughter. Which drug was the teenager most likely using?

Question: Which drug was the teenager most likely using?

Answer: Oxycodone


Context: A group of researchers is studying molecules and DNA segments that are critical for important cellular processes in eukaryotic cells. They have identified a region that is located about 28 bases upstream of the 5’ coding region. This region promotes the initiation of transcription by binding with transcription factors. Which of the following regions have these researchers most likely identified?

Question: Which of the following regions have these researchers most likely identified?

Answer: TATA Box


Context: A 24-year-old woman with HIV infection comes to the physician for a follow-up examination. She has been inconsistently taking combined antiretroviral therapy for the past 5 years. She did not receive any childhood vaccinations because her parents were against them. During the consultation, the patient says that she wants to catch up on the missed vaccinations. Laboratory studies show a CD4+ T lymphocyte cell count of 180/mm3. Administration of the vaccine against which of the following agents should be avoided in this patient?

Question: Administration of the vaccine against which of the following agents should be avoided in this patient?

Answer: Varicella zoster virus


Context:
A 77-year-old woman is brought to the emergency department from her nursing home because she was found down overnight. On presentation she was found to be delirious and was unable to answer questions. Chart review shows that she is allergic to cephalosporins. Her temperature is 102.2°F (39°C), blood pressure is 105/52 mmHg, pulse is 94/min, and respirations are 23/min. Physical exam reveals a productive cough. A metabolic panel is obtained with the following results:

Serum:
Na+: 135 mEq/L
Cl-: 95 mEq/L
K+: 4 mEq/L
HCO3-: 19 mEq/L
BUN: 40 mg/dL
Creatinine: 2.5 mg/dL
Glucose: 150 mg/dL

Based on these findings two different drugs are started empirically. Gram stain on a blood sample is performed showing the presence of gram-positive organisms on all samples. One of the drugs is subsequently stopped. The drug that was most likely stopped has which of the following characteristics?

Question: The drug that was most likely stopped has which of the following characteristics?

Answer: Single-ringed ß-lactam structure


Context: A 30-year-old man presents to the physician after he discovered a raised, red, string-shaped lesion beneath the skin on his right foot. The lesion seems to move from one location to another over the dorsum of his foot from day to day. He says that the the lesion is extremely itchy and has not responded to over the counter topical treatment. He and his wife recently returned from a honeymoon in southern Thailand, where they frequented the tropical beaches. The physician diagnoses him with a parasitic infection and prescribes albendazole for the patient. With which of the following organisms is the patient most likely infected?

Question: With which of the following organisms is the patient most likely infected?

Answer: Ancylostoma braziliense


Context:
A 56-year-old man comes to the emergency department because of progressive swelling and pain in his left calf for 1 day. He does not have shortness of breath or chest pain. He has hypertension and chronic kidney disease. Current medications include enalapril, aspirin, simvastatin, and vitamin D. His temperature is 100.4°F (38°C), pulse is 84/min, and blood pressure is 135/92 mm Hg. Physical examination shows tenderness and swelling of the left lower extremity. A venous Doppler ultrasonography shows a thrombus in the left popliteal vein. Treatment with unfractionated heparin is begun. Two days later, physical examination shows improvement of symptoms. Laboratory studies at admission and 2 days after admission show:
Admission Two days after admission
Hemoglobin 11.2 g/dL 11.1 g/dL
Leukocyte count 5,500/mm3 6,100/mm3
Platelet count 230,000/mm3 170,000/mm3
Serum
Prothrombin time 12 seconds 13 seconds
Partial thromboplastin time 30 seconds 55 seconds
Estimated glomerular filtration rate 29 mL/min/1.73 m2 28 mL/min/1.73 m2
Which of the following is the most appropriate next step in management?"

Question:
Laboratory studies at admission and 2 days after admission show:
Admission Two days after admission
Hemoglobin 11.2 g/dL 11.1 g/dL
Leukocyte count 5,500/mm3 6,100/mm3
Platelet count 230,000/mm3 170,000/mm3
Serum
Prothrombin time 12 seconds 13 seconds
Partial thromboplastin time 30 seconds 55 seconds
Estimated glomerular filtration rate 29 mL/min/1.73 m2 28 mL/min/1.73 m2
Which of the following is the most appropriate next step in management?"

Answer: Continue unfractionated heparin


Context: An 84-year-old woman is brought to the physician by her son after he found her trying to hang herself from the ceiling because she felt that she was a burden to her family. Her family says that for the past 2 months she has had no energy to leave her room, has been sleeping most of the day, has lost 10 kg (22 lb), and cries every day. She was diagnosed with breast cancer that has metastasized to the liver 4 months ago. She moved in with her son and daughter-in-law shortly after the diagnosis. She initially underwent chemotherapy but discontinued the treatment when the metastases spread to the spine and brain. Her life expectancy is 1–2 weeks and she is currently receiving home-hospice care. Her only current medication is a fentanyl patch. She is 160 cm (5 ft 3 in) tall and weighs 46 kg (101.4 lb); BMI is 18 kg/m2. Her vital signs are within normal limits. Examination shows slow speech, a flat affect, and depressed mood. Which of the following treatments is initially most likely to provide the greatest benefit for this patient?

Question: Which of the following treatments is initially most likely to provide the greatest benefit for this patient?

Answer: Methylphenidate


Context: A 29-year-old G1P0 woman at 24 weeks gestation presents to her physician with complaints of burning with urination, and she reports that she has been urinating much more frequently than usual over the past several days. She otherwise is doing well and has experienced no complications with her pregnancy or vaginal discharge. Her temperature is 97.5°F (36.4°C), blood pressure is 112/82 mmHg, pulse is 89/min, respirations are 19/min, and oxygen saturation is 98% on room air. Examination is significant for suprapubic discomfort upon palpation and a gravid uterus. There is no costovertebral angle tenderness. Urinalysis shows increased leukocyte esterase, elevated nitrites, 55 leukocytes/hpf, and bacteria. The physician prescribes a 7-day course of nitrofurantoin. Which of the following is the next best step in management?

Question: Which of the following is the next best step in management?

Answer: Send a urine culture


Context: A steel welder presents to his family physician with a one-week history of intense abdominal cramping with nausea, vomiting, constipation, headaches, myalgias, and arthralgias. He claims that the symptoms started about two months after he began work on replacing the pipes in an early 20th century house. Blood was taken and he was found to have a microcytic, hypochromic anemia with basophilic stippling. Which of the following is the best treatment for his symptoms?

Question: Which of the following is the best treatment for his symptoms?

Answer: EDTA


Context: A 38-year-old man arrives at the emergency department with severe periumbilical, colicky pain and abdominal distention for the past 2 days. He is nauseated and reports vomiting light-green emesis 8 times since yesterday morning. He has not had a bowel movement or passed any gas for the past 3 days. He has a past medical history of ventral hernia repair 5 years ago. His heart rate is 110/min, respiratory rate is 24/min, temperature is 38.0°C (100.4°F), and blood pressure is 120/90 mm Hg. The abdomen is distended and mildly tender to deep palpation. Bowel sounds are high-pitched and tinkling. Which of the following is the most likely cause?

Question: Which of the following is the most likely cause?

Answer: Small bowel obstruction


Context: A 4-week-old Caucasian baby presents for a routine checkup. The patient was born to a 28-year-old G1P1 woman at 38 weeks estimated gestational age by cesarean section secondary to breech presentation. The pregnancy was complicated by gestational diabetes, which the mother controlled with diet and exercise. Prenatal ultrasounds showed normal fetal anatomy. Both parents are nonsmokers. The vital signs include: temperature 37.0°C (98.6°F), blood pressure 85/45 mm Hg, pulse 140/min, respiratory rate 42/min, and oxygen saturation 99% on room air. Height, weight, and head circumference are within the 90th percentile. Positive Moro and Babinski reflexes are present. The cardiopulmonary examination is normal. While in the supine position, the left leg is visibly shortened relative to the right. When the left hip is abducted with pressure applied to the greater trochanter of the femur, there is a non-tender clunking sound elicited. There is asymmetry of the labial skin folds. A blue macule is noted over the sacral region. Which of the following is the most appropriate next step in the management of this patient?

Question: Which of the following is the most appropriate next step in the management of this patient?

Answer: Ultrasound of the hips


Context: A 24-year-old man presents to the emergency department complaining of a prolonged course of diarrhea. He reports that he has had 3–4 large volume watery stools daily for the last several weeks. He has no pain with bowel movements, no abdominal pain, and no blood in his stools. He is homeless and uses recreational drugs. He also reports that he usually drinks a half-liter of whiskey, or whatever else he can find, every day and he has done this for several years. The physical exam is notable for a hyperpigmented rash across his face, neck, chest, and the backs of his hands and forearms. On mental status exam, he is oriented to person and place but not time; he scores a 23/30 on the Montreal Cognitive Assessment (MOCA). This patient's presentation is most likely related to which of the following micronutrients?

Question: This patient's presentation is most likely related to which of the following micronutrients?

Answer: Vitamin B3


Context: The World Health Organization suggests the use of a new rapid diagnostic test for the diagnosis of malaria in resource-limited settings. The new test has a sensitivity of 70% and a specificity of 90% compared to the gold standard test (blood smear). The validity of the new test is evaluated at a satellite health center by testing 200 patients with a positive blood smear and 150 patients with a negative blood smear. How many of the tested individuals are expected to have a false negative result?

Question: How many of the tested individuals are expected to have a false negative result?

Answer: 60


Context: A 21-year-old woman presents into the clinic worried that she might be pregnant. Her last menstrual period was 4 months ago and recalls that she did have unprotected sex with her boyfriend, despite not having sexual desire. They have since broken up, and she would like to do a pregnancy test. She appears very emaciated but is physically active. She says that she spends a few hours in the gym almost every day but would spend longer if she was to stray from her diet so that she does not gain any weight. Her calculated BMI is 17 kg/m2, and her urine pregnancy test is negative. Which of the following additional findings would most likely be present in this patient?

Question: Which of the following additional findings would most likely be present in this patient?

Answer: Orthostasis


Context: An 18-year-old Caucasian female presents to your clinic because of a recent increase in thirst and hunger. Urinalysis demonstrates elevated glucose. The patient's BMI is 20. Which of the following is the most common cause of death in persons suffering from this patient's illness?

Question: Which of the following is the most common cause of death in persons suffering from this patient's illness?

Answer: Myocardial infarction


Context: A 17-year-old girl presents to the clinic on her own, complaining of fatigue and feeling cold all the time. She is also very concerned about several minor medical conditions she has developed over the last year or so. Her past medical history is noncontributory. Menarche was at age 11 and her last menstrual period was 3 months ago. Her mother has hypothyroidism and she is concerned that she has it too. She proudly describes her “healthy” routine that consists of 2 grapefruits a day for breakfast and lunch and no dinner and that she runs 6 miles 4 times a week. She reports having good grades in school and that she tries very hard to fit in with the popular girls. She is also concerned that she has trouble losing weight and persistently asks for a prescription for weight loss medication. Her temperature is 36.9°C (98.5°F), blood pressure is 110/70 mm Hg, pulse is 60/min, and respirations are 13/min. Physical examination reveals a thin girl with pale mucosa and lanugo on her arms and back. Urine hCG is negative. Which of the following will most likely be detected in this patient?

Question: Which of the following will most likely be detected in this patient?

Answer: BMI less than 17


Context: A 78-year-old man dies suddenly from complications of acute kidney failure. An autopsy is performed and microscopic evaluation of the kidneys shows pale, swollen cells in the proximal convoluted tubules. Microscopic evaluation of the liver shows similar findings. Which of the following is the most likely underlying mechanism of these findings?

Question: Which of the following is the most likely underlying mechanism of these findings?

Answer: Impaired Na+/K+-ATPase pump activity


Context:
A 49-year-old man comes to the physician because of a 2-week history of increasing shortness of breath. He has also had chest pain that is exacerbated by deep inspiration. He has had recurrent episodes of pain in his fingers for the past 2 years. Two years ago, he was treated for a deep vein thrombosis. He has hypertension and anxiety. Current medications include enalapril, St John's wort, and ibuprofen. His temperature is 37°C (98.6°F), pulse is 110/min, respirations are 17/min, and blood pressure is 110/70 mm Hg. Examination shows pale conjunctiva. There is tenderness to palpation of the proximal interphalangeal and metacarpophalangeal joints of both hands. Heart sounds are distant. The lungs are clear to auscultation. Laboratory studies show:
Hemoglobin 11.9 g/dL
Leukocyte count 4200/mm3
Platelet count 330,000/mm3
Serum
Na+ 136 mEq/L
K+ 4.3 mEq/L
Antinuclear antibodies 1: 320
Anti-SM-1 antibodies positive
Anti-CCP antibodies negative
An x-ray of the chest is shown. Which of the following is most likely to be seen on this patient's ECG?"

Question: Which of the following is most likely to be seen on this patient's ECG?"

Answer: Electric alternans


Context: A 32-year-old male presents to his primary care provider for headache. He reports that he has headaches at night several times a week. He first developed these headaches over a year ago, but he had not had any for several months before they started up again three weeks ago. The episodes start suddenly and feel like a stabbing, electrical pain over his left eye. He also reports tearing of the left eye during these episodes. The headaches self-resolve over the course of 2-3 hours, but the patient complains that he is avoiding going to sleep for fear of waking up in pain. His past medical history includes type I diabetes mellitus and an episode of herpes zoster on his right flank one year ago. His only home medication is insulin. On physical exam, his extraocular muscles are intact and his eyes are not injected and without lacrimation. A CT of the head and sinuses shows no acute abnormalities. Which of the following is most likely to prevent future episodes of headache in this patient?

Question: Which of the following is most likely to prevent future episodes of headache in this patient?

Answer: Verapamil


Context: A 23-year-old woman presents to the emergency department with severe abdominal pain. The pain started suddenly several hours ago and has steadily worsened. The patient has a past medical history of anxiety and depression. Her current medications include sertraline, sodium docusate, a multivitamin, and fish oil. The patient is currently sexually active with her boyfriend and uses the "pull-out" method for contraception. A pelvic ultrasound in the emergency room reveals an ectopic pregnancy. The patient is scheduled for surgery and is promptly treated. She is recovering on the surgical floor. The procedure was complicated by a large amount of blood loss. The patient is recovering on IV fluids when her family comes to visit. When her parents find out the diagnosis, yelling ensues and they leave angrily. The patient is scheduled to go home today. Prior to discharge, the patient reports she is unable to use her left hand. Upon examination, she is teary-eyed and she claims that she has “the worst family in the world,” and she does not want to go home. Physical exam reveals no skin or bony abnormalities of the left arm. Strength is 0/5 in the left upper extremity. She does not recoil her left arm to pain. A MRI is obtained and is unremarkable. The rest of the patient’s neurological exam is within normal limits. Which of the following is the most likely diagnosis?

Question: Which of the following is the most likely diagnosis?

Answer: Conversion disorder


Context: A 27-year-old woman presents with acute abdominal pain in her right upper quadrant. The pain came on suddenly while she was eating dinner. After this pain she began feeling dizzy and came to the emergency department. In the ED, her blood pressure is 75/40 mmHg, pulse is 100/minute, and she is afebrile. On physical exam, she feels too light-headed to ambulate. She demonstrates normal bowel sounds with tenderness upon palpation in the right upper quadrant. The patient is deemed too unstable for imaging. An abdominal radiograph and CT are reviewed from a recent previous visit to the ED for mild abdominal pain, and are shown in Figures A and B, respectively. Which of the following specific additional findings in her history supports the most likely diagnosis?

Question: Which of the following specific additional findings in her history supports the most likely diagnosis?

Answer: Use of oral contraceptives (OCPs) for birth control


Context: A 2-year-old boy is brought to the physician because of a productive cough for 5 days. He has a history of recurrent lower respiratory tract infections and sinusitis treated with oral antibiotics. He frequently has loose stools that do not flush easily. He was born at 37 weeks' gestation and the neonatal period was complicated by meconium ileus. His immunizations are up-to-date. He is at the 15th percentile for height and at the 5th percentile for weight. His temperature is 37.1°C (98.8°F), pulse is 98/min, and respirations are 38/min. Pulse oximetry on room air shows an oxygen saturation of 95%. Examination shows bilateral nasal polyps. There are scattered inspiratory crackles heard in the thorax. Further evaluation of this patient is most likely to show which of the following?

Question: Further evaluation of this patient is most likely to show which of the following?

Answer: Elevated prothrombin time


Context: A 37-year-old man is brought to the emergency department by his wife after having a seizure. He has a 1-week history of headaches, blurry vision in his right eye, and muscle pain in his arms and neck. He has no history of a seizure disorder, and his vision was normal until the onset of his symptoms 1 week ago. He has a history of migraine headaches that occur on a monthly basis and are relieved with ibuprofen. He immigrated from Ecuador 6 years ago and often returns to visit his family. He appears confused. His vital signs are within normal limits. Ophthalmologic examination shows subretinal cysts. An MRI of the brain shows multiple small, ring-enhancing lesions in the parenchyma. A lumbar puncture is done; cerebrospinal fluid analysis shows numerous eosinophils and a protein concentration of 53 mg/dL. Which of the following is the most likely direct cause of infection in this patient?

Question: Which of the following is the most likely direct cause of infection in this patient?

Answer: Ingestion of eggs from human feces


Context: An 8-year-old boy is being seen in your neurology clinic for seizures of the type observed in video V. While speaking with the child, you notice that he frequently asks you to repeat yourself, and looks at you occasionally with a blank stare. Which of the following medications would be most appropriate for this patient?

Question: Which of the following medications would be most appropriate for this patient?

Answer: Valproic acid


Context: A 72-year-old man presents to the clinic for the evaluation of a lesion on his nose that has been slowly getting larger for the past 2 months. The patient notes no history of trauma, pruritus, or pain, but states that the size of the lesion is making his nose feel uncomfortable. On exam, the nodule is pink with rolled borders. Telangiectasias are also present within the lesion, with central ulceration. What is the characteristic histologic appearance of this lesion?

Question: What is the characteristic histologic appearance of this lesion?

Answer: Palisading nuclei


Context: A 4-year-old boy is brought to the emergency department with 2 days of fever and painful lumps in his legs bilaterally. In addition, he says that his arms and legs are extremely itchy. Since birth he has had recurrent skin and soft tissue infections. Physical exam reveals a pruritic erythematous scaling rash along both upper and lower extremities bilaterally. Palpation of the painful lesions reveal indurated tissue without any production of pus. Which of the following protein functions is most likely disrupted in this patient?

Question: Which of the following protein functions is most likely disrupted in this patient?

Answer: Transcription factor activity


Context: A 45-year-old woman presents to her primary care physician for an annual checkup. She states that she feels well and has no complaints. She lives alone and works as a banker. She smokes 1 cigarette per day and drinks 2 alcoholic beverages per night. She occasionally gets symmetrical pain in her hands where they change from red to white to blue then return to normal again. Her temperature is 98.7°F (37.1°C), blood pressure is 177/118 mmHg, pulse is 82/min, respirations are 15/min, and oxygen saturation is 99% on room air. The patient's hypertension is treated, and she returns 2 weeks later complaining of weight gain in her legs and arms. On exam, bilateral edema is noted in her extremities. Which of the following is the best next step in management?

Question: Which of the following is the best next step in management?

Answer: Lisinopril


Context:
А 55-уеаr-old mаn рrеѕеntѕ to hіѕ рrіmаrу саrе рhуѕісіаn wіth a сomрlаіnt of fatigue for a couple of months. He was feeling well during his last visit 6 months ago. He has a history of hypertension for the past 8 years, diabetes mellitus for the past 5 years, and chronic kidney disease (CKD) for a year. The vіtаl ѕіgnѕ include: blood рrеѕѕurе 138/84 mm Нg, рulѕе 81/mіn, tеmреrаturе 36.8°C (98.2°F), аnd rеѕріrаtorу rаtе 9/mіn. Оn physical ехаmіnаtіon, modеrаtе раllor іѕ noted on thе раlреbrаl сonјunсtіvа аnd nаіl bеd.
Complete blood count results are as follows:
Hemoglobin 8.5 g/dL
RBC 4.2 million cells/µL
Hematocrit 39%
Total leukocyte count 6,500 cells/µL cells/µL
Neutrophils 61%
Lymphocyte 34%
Monocytes 4%
Eosinophil 1%
Basophils 0%
Platelets 240,000 cells/µL
A basic metabolic panel shows:
Sodium 133 mEq/L
Potassium 5.8 mEq/L
Chloride 101 mEq/L
Bicarbonate 21 mEq/L
Albumin 3.1 mg/dL
Urea nitrogen 31 mg/dL
Creatinine 2.8 mg/dL
Uric Acid 6.4 mg/dL
Calcium 8.1 mg/dL
Glucose 111 mg/dL
Which of the following explanation best explains the mechanism for his decreased hemoglobin?

Question:
Complete blood count results are as follows:
Hemoglobin 8.5 g/dL
RBC 4.2 million cells/µL
Hematocrit 39%
Total leukocyte count 6,500 cells/µL cells/µL
Neutrophils 61%
Lymphocyte 34%
Monocytes 4%
Eosinophil 1%
Basophils 0%
Platelets 240,000 cells/µL
A basic metabolic panel shows:
Sodium 133 mEq/L
Potassium 5.8 mEq/L
Chloride 101 mEq/L
Bicarbonate 21 mEq/L
Albumin 3.1 mg/dL
Urea nitrogen 31 mg/dL
Creatinine 2.8 mg/dL
Uric Acid 6.4 mg/dL
Calcium 8.1 mg/dL
Glucose 111 mg/dL
Which of the following explanation best explains the mechanism for his decreased hemoglobin?

Answer: Failure of adequate erythropoietin production


Context:
A 25-year-old woman, gravida 2, para 1, at 25 weeks' gestation comes to the emergency department because of a 1-day history of fever and right-sided flank pain. During this period, she also had chills, nausea, vomiting, and burning on urination. Her last prenatal visit was 10 weeks ago. Pregnancy and delivery of her first child were uncomplicated. Her temperature is 39°C (102.2°F), pulse is 110/min, respirations are 20/min, and blood pressure is 110/70 mm Hg. Physical examination shows costovertebral angle tenderness on the right. The abdomen is soft and nontender, and no contractions are felt. Pelvic examination shows a uterus consistent in size with a 25-week gestation. Fetal heart rate is 170/min. Laboratory studies show:
Leukocyte count 15,000/mm3
Urine
Nitrite 2+
Protein 1+
Blood 1+
RBC 5/hpf
WBC 500/hpf
Blood and urine samples are obtained for culture and drug sensitivity. Which of the following is the most appropriate next step in management?"

Question: Which of the following is the most appropriate next step in management?"

Answer: Inpatient treatment with intravenous ceftriaxone


Context: A 34-year-old G2P2 undergoes colposcopy due to high-grade intraepithelial neoplasia detected on a Pap smear. Her 2 previous Pap smears showed low-grade intraepithelial neoplasia. She has had 2 sexual partners in her life, and her husband has been her only sexual partner for the last 10 years. She had her sexual debut at 16 years of age. She had her first pregnancy at 26 years of age. She uses oral contraceptives for birth control. Her medical history is significant for right ovary resection due to a large follicular cyst and cocaine abuse for which she completed a rehabilitation program. Colposcopy reveals an acetowhite lesion with distorted vascularity at 4 o’clock. A directed biopsy shows the following on histologic evaluation. Which of the following factors present in this patient is a risk factor for the detected condition?

Question: Which of the following factors present in this patient is a risk factor for the detected condition?

Answer: Age of sexual debut


Context:
A 71-year-old man is brought in by his wife with acute onset aphasia and weakness in his right arm and leg for the past 2 hours. The patient’s wife says they were eating breakfast when he suddenly could not speak. His symptoms have not improved over the past 2 hours. The patient denies any similar symptoms in the past. His past medical history is significant for immune thrombocytopenic purpura, managed intermittently with oral prednisone, hypertension, managed with hydrochlorothiazide, and a previous myocardial infarction (MI) 6 months ago. The patient reports a 20-pack-year smoking history and moderate daily alcohol use. His family history is significant for his father who died of an MI at age 58 and his older brother who died of a stroke at age 59. The vital signs include: blood pressure 175/105 mm Hg, pulse 85/min, and respiratory rate 20/min. On physical examination, there is a noticeable weakness of the lower facial muscles on the right. The muscle strength in his upper and lower extremities is 4/5 on the right and 5/5 on the left. There is also a loss of sensation on the right. He has productive aphasia. The laboratory findings are significant for the following:
WBC 7,500/mm3
RBC 4.40 x 106/mm3
Hematocrit 41.5%
Hemoglobin 14.0 g/dL
Platelet count 95,000/mm3
A noncontrast computed tomography (CT) scan of the head is unremarkable. Diffusion-weighted magnetic resonance imaging (MRI) and CT angiography (CTA) confirms a left middle cerebral artery (MCA) ischemic stroke. Which of the following aspects of this patient’s history is a contraindication to intravenous (IV) tissue plasminogen activator (tPA)?

Question: Which of the following aspects of this patient’s history is a contraindication to intravenous (IV) tissue plasminogen activator (tPA)?

Answer: Platelet count 95,000/mm3


Context:
A 62-year-old man is brought to the emergency department because of progressive shortness of breath, mild chest pain on exertion, and a cough for 2 days. One week ago, he had a low-grade fever and nasal congestion. He has hypertension but does not adhere to his medication regimen. He has smoked one pack of cigarettes daily for 30 years and drinks 3–4 beers daily. His temperature is 37.1°C (98.8°F), pulse is 125/min, respirations are 29/min, and blood pressure is 145/86 mm Hg. He is in moderate respiratory distress while sitting. Pulmonary examination shows reduced breath sounds bilaterally. There is scattered wheezing over all lung fields. There is inward displacement of his abdomen during inspiration. Arterial blood gas analysis shows:
pH 7.29
PCO2 63 mm Hg
PO2 71 mm Hg
HCO3- 29 mEq/L
O2 saturation 89%
Which of the following is the most likely cause of this patient's symptoms?"

Question:
Arterial blood gas analysis shows:
pH 7.29
PCO2 63 mm Hg
PO2 71 mm Hg
HCO3- 29 mEq/L
O2 saturation 89%
Which of the following is the most likely cause of this patient's symptoms?"

Answer: Acute exacerbation of chronic obstructive pulmonary disease


Context: A research group designs a study to investigate the epidemiology of syphilis in the United States. After a review of medical records, the investigators identify patients who are active cocaine users but did not have a history of syphilis as of one year ago. Another group of similar patients with no history of cocaine use or syphilis infection is also identified. The investigators examine the medical charts to determine whether the group of patients who are actively using cocaine was more likely to have developed syphilis over a 6-month period. The investigators ultimately found that the rate of syphilis was 30% higher in patients with active cocaine use compared to patients without cocaine use. This study is best described as which of the following?

Question: This study is best described as which of the following?

Answer: Retrospective cohort study


Context: A 31-year-old man comes to the emergency department because of drooping of the left side of his face since awakening that morning. He had difficulty chewing his food at breakfast. He was treated the previous day at the hospital after sustaining a head injury from falling off a ladder while working on his roof. A plain CT of the brain at that visit showed no abnormalities. He is in no apparent distress. His vital signs are within normal limits. The pupils are equal and reactive to light. There is drooping of the left corner of the mouth. The left nasolabial fold is flattened. When asked to close both eyes, the left eye remains partially open. There are no wrinkles on the left side of the forehead when the eyebrows are raised. Which of the following is the most appropriate next step in management?

Question: Which of the following is the most appropriate next step in management?

Answer: Steroid therapy


Context:
A 52-year-old woman is accompanied by her husband to the emergency department with a severe occipital headache that started suddenly an hour ago. She is drowsy but able to answer the physician’s questions. She describes it as the worst headache she has ever had, 9/10 in intensity. The husband says it was initially localized to the occiput but has now spread all over her head and she also complained of a generalized heaviness. She took an ibuprofen without experiencing any relief. She also complains of blurry vision and nausea and had 1 episode of vomiting. She denies a recent history of fever, chills, numbness, or seizures. Her past medical history is significant for hypertension controlled with lisinopril and metoprolol. On examination, she is drowsy but oriented. Papilledema is seen on ophthalmoscopy. Neck flexion is difficult and painful. The rest of the exam is unremarkable. Her blood pressure is 160/100 mm Hg, heart rate is 100/min, and temperature is 37.0°C (98.6°F). The ECG, cardiac enzymes, and laboratory studies are normal. Lumbar puncture results are as follows:
Opening pressure 210 mm H2O
RBC 50/mm3, numbers steady over 4 test tubes
Cell count 5/mm3
Glucose 40 mg/dL
Proteins 100 mg/dL
The patient is admitted to the ICU for further management. Which of the following is the most likely pathophysiology based on her history and CSF findings?

Question: Which of the following is the most likely pathophysiology based on her history and CSF findings?

Answer: Rupture of the communicating branches of the cerebral arteries


Context: A 40-year-old man presents to a clinic in Michigan in December complaining of painful blue fingers and toes. He also complains of numbness and tingling. The patient’s vital signs are within normal limits, and his symptoms typically disappear when he comes back into a warm room. The patient also notes that he recently moved to the area from Arizona and had recently recovered from a viral infection in which he had a low-grade fever and severe lymphadenopathy. Which of the following tests would most likely be positive in this patient?

Question: Which of the following tests would most likely be positive in this patient?

Answer: Direct Coomb’s test with anti-C3 reagent


Context: A drug research team has synthesized a novel oral drug that acts as an agonist at multiple adrenergic receptors. When administered in animals, it has been shown to produce urinary retention at therapeutic doses with the absence of other manifestations of adrenergic stimulation. The researchers are interested in understanding signal transduction and molecular mechanisms behind the action of the novel drug. Which of the following receptors would most likely transduce signals across the plasma membrane following the administration of this novel drug?

Question: Which of the following receptors would most likely transduce signals across the plasma membrane following the administration of this novel drug?

Answer: GqPCRs (Gq protein-coupled receptors)


Context: A 31-year-old man comes to the physician because of a 2-day history of abdominal pain and diarrhea. He reports that his stools are streaked with blood and mucus. He returned from a vacation in the Philippines 3 weeks ago. His vital signs are within normal limits. Abdominal examination shows hyperactive bowel sounds. A photomicrograph of a trichrome-stained wet mount of a stool specimen is shown. Which of the following organisms is the most likely cause of this patient's symptoms?

Question: Which of the following organisms is the most likely cause of this patient's symptoms?

Answer: Entamoeba histolytica


Context: A 25-year-old man is admitted to the emergency department because of an episode of acute psychosis with suicidal ideation. He has no history of serious illness and currently takes no medications. Despite appropriate safety precautions, he manages to leave the examination room unattended. Shortly afterward, he is found lying outside the emergency department. A visitor reports that she saw the patient climbing up the facade of the hospital building. He does not respond to questions but points to his head when asked about pain. His pulse is 131/min, respirations are 22/min, and blood pressure is 95/61 mm Hg. Physical examination shows a 1-cm head laceration and an open fracture of the right tibia. He opens his eyes spontaneously. Pupils are equal, round, and reactive to light. Breath sounds are decreased over the right lung field, and the upper right hemithorax is hyperresonant to percussion. Which of the following is the most appropriate next step in management?

Question: Which of the following is the most appropriate next step in management?

Answer: Apply a cervical collar


Context: Given the pattern of inheritance shown in the pedigree, where might you find the disease gene in question?

Question: Given the pattern of inheritance shown in the pedigree, where might you find the disease gene in question?

Answer: On circular DNA in the mitochondrion


Context: A 24-year-old man presents to the emergency room with a stab wound to the left chest at the sternocostal junction at the 4th intercostal space. The patient is hemodynamically unstable, and the trauma attending is concerned that there is penetrating trauma to the heart as. Which cardiovascular structure is most likely to be injured first in this stab wound?

Question: Which cardiovascular structure is most likely to be injured first in this stab wound?

Answer: Right ventricle


Context: A 24-year-old man comes to the physician with a wound on his forearm. He says that he injured himself by absentmindedly walking into a glass door. He does not have health insurance. He has had 5 jobs in the past 8 months. He quit each job after 3–4 weeks because he found the work beneath him. He was imprisoned 6 years ago for credit card fraud. He was released from prison on parole a year ago. He was expelled from school at the age of 13 years for stealing school property and threatening to assault a teacher. He has fathered 6 children with 4 women. He says that he does not provide child support because he needs the money for his own personal expenses. The patient's vital signs are within normal limits. Examination of the forearm shows a 6 cm long, 0.5 cm deep wound with neat edges on the dorsal surface of the left forearm. There are bruises on the left shoulder, back, and the proximal phalanges of the right hand. On mental status examination, the patient is alert and calm. His mood is described as cheerful. His thought process, thought content, and speech are normal. Which of the following is the most likely diagnosis?

Question: Which of the following is the most likely diagnosis?

Answer: Antisocial personality disorder


Context: While performing a Western blot, a graduate student spilled a small amount of the radiolabeled antibody on her left forearm. Although very little harm was done to the skin, the radiation did cause minor damage to the DNA of the exposed skin by severing covalent bonds between the nitrogenous bases and the core ribose leaving several apurinic/apyrimidinic sites. Damaged cells would most likely repair these sites by which of the following mechanisms?

Question: Damaged cells would most likely repair these sites by which of the following mechanisms?

Answer: Base excision repair


Context: A 2-year-old girl presents to the pediatrician with an itchy rash. Her mother reports that she has had a crusty rash on the face and bilateral upper extremities intermittently for the past 2 months. The child's past medical history is notable for 3 similar episodes of severely itchy rashes since birth. She has also had 2 non-inflamed abscesses on her arms over the past year. Her temperature is 98.9°F (37.2°C), blood pressure is 108/68 mmHg, pulse is 94/min, and respirations are 18/min. On exam, she appears uncomfortable and is constantly itching her face and arms. There is an eczematous rash on the face and bilateral upper extremities. Her face has thickened skin with a wide-set nose. This patient's condition is most likely caused by a mutation in which of the following genes?

Question: This patient's condition is most likely caused by a mutation in which of the following genes?

Answer: STAT3


Context: A 32-year-old farmer is brought to the emergency department by his wife. The patient was reportedly anxious, sweaty, and complaining of a headache and chest tightness before losing consciousness on route to the hospital. Which of the following is mechanistically responsible for this patient's symptoms?

Question: Which of the following is mechanistically responsible for this patient's symptoms?

Answer: Irreversible inhibition of acetylcholinesterase


Context: An 8-year-old boy is brought to the emergency department by his parents 30 minutes after losing consciousness. He was at a water park with his family when he fell to the ground and started to have jerking movements of the arms and legs. On arrival, he continues to have generalized, violent muscle contractions and is unresponsive to verbal and painful stimuli. The emergency department physician administers lorazepam. The expected beneficial effect of this drug is most likely caused by which of the following mechanisms?

Question: The expected beneficial effect of this drug is most likely caused by which of the following mechanisms?

Answer: Allosteric activation of GABAA receptors


Context: A 48-year-old multiparous woman visits the clinic for her annual physical check-up. During the interview, you find out that her father passed away 5 months ago after massive blood loss secondary to lower gastrointestinal bleeding, and both her younger siblings (45 and 42 years of age) were recently diagnosed with various colonic lesions compatible with colorectal cancer. The diet history reveals that the patient consumes large amounts of fried food and sugary drinks. She has smoked 1 pack of cigarettes every day for the last 10 years and frequently binges drinks to ‘calm her nerves’. The medical history is significant for estrogen-progestin therapy (to control menopausal vasomotor symptoms) and hypertension. The vital signs include a blood pressure of 139/66 mm Hg, a pulse of 72/min, a temperature of 37.2°C (99.0°F), and a respiratory rate of 16/min. Physical examination is unremarkable, except for a BMI of 38 kg/m² and a lesion in her axilla, as shown in the image. You explain that she needs to start taking care of herself by modifying her lifestyle to lower her increased risk for endometrial carcinoma. Which of the following is the most important risk factor for this patient?

Question: Which of the following is the most important risk factor for this patient?

Answer: Family history


Context: Three days after admission to the hospital following a motor vehicle accident, a 45-year-old woman develops a fever. A central venous catheter was placed on the day of admission for treatment of severe hypotension. Her temperature is 39.2°C (102.5°F). Examination shows erythema surrounding the catheter insertion site at the right internal jugular vein. Blood cultures show gram-positive, catalase-positive cocci that have a low minimum inhibitory concentration when exposed to novobiocin. Which of the following is the most appropriate pharmacotherapy?

Question: Which of the following is the most appropriate pharmacotherapy?

Answer: Vancomycin


Context: A 23-year-old woman presents to the emergency department with abnormal vaginal discharge and itchiness. She states it started a few days ago and has been worsening. The patient has a past medical history of a medical abortion completed 1 year ago. Her temperature is 98.6°F (37.0°C), blood pressure is 129/68 mmHg, pulse is 80/min, respirations are 14/min, and oxygen saturation is 99% on room air. Physical exam demonstrates an anxious woman. Pelvic exam reveals yellow cervical discharge. Nucleic acid amplification test is negative for Neisseria species. Which of the following is the best next step in management?

Question: Which of the following is the best next step in management?

Answer: Azithromycin


Context:
A 64-year-old man presents to the emergency department with sudden onset of pleuritic chest pain and dyspnea on exertion. He has a history of lung cancer and is currently being treated with outpatient chemotherapy. His temperature is 98.9°F (37.2°C), blood pressure is 111/64 mmHg, pulse is 130/min, respirations are 25/min, and oxygen saturation is 90% on room air. Initial laboratory values in the emergency department are seen below.

Hemoglobin: 8.2 g/dL
Hematocrit: 26%
Leukocyte count: 7,700/mm^3 with normal differential
Platelet count: 157,000/mm^3

A CT angiogram demonstrates a blood clot in the pulmonary vasculature. The patient is started on heparin and he is admitted to the ICU. Laboratory values 6 days later are shown below.

Hemoglobin: 8.0 g/dL
Hematocrit: 25%
Leukocyte count: 7,500/mm^3 with normal differential
Platelet count: 22,000/mm^3

Which of the following is the most appropriate next step in management?

Question:
Hemoglobin: 8.0 g/dL
Hematocrit: 25%
Leukocyte count: 7,500/mm^3 with normal differential
Platelet count: 22,000/mm^3

Which of the following is the most appropriate next step in management?

Answer: Stop heparin


Context: A 36-year-old woman comes to the physician because of prolonged stiffness in the morning and progressive pain and swelling of her wrists and hands over the past 4 months. Examination shows bilateral swelling and mild tenderness of the wrists and the second, third, and fourth metacarpophalangeal joints. Her range of motion is limited by pain. Serum studies show elevated anti-cyclic citrullinated peptide antibodies. Treatment with methotrexate is begun. At a follow-up examination, her serum aspartate aminotransferase (AST) concentration is 75 U/L and her serum alanine aminotransferase (ALT) concentration is 81 U/L. Which of the following substances is essential for the function of these enzymes?

Question: Which of the following substances is essential for the function of these enzymes?

Answer: Pyridoxine


Context: An 82-year-old woman comes to the physician because of difficulty sleeping and increasing fatigue. Over the past 3 months she has been waking up early and having trouble falling asleep at night. During this period, she has had a decreased appetite and a 3.2-kg (7-lb) weight loss. Since the death of her husband one year ago, she has been living with her son and his wife. She is worried and feels guilty because she does not want to impose on them. She has stopped going to meetings at the senior center because she does not enjoy them anymore and also because she feels uncomfortable asking her son to give her a ride, especially since her son has had a great deal of stress lately. She is 155 cm (5 ft 1 in) tall and weighs 51 kg (110 lb); BMI is 21 kg/m2. Vital signs are within normal limits. Physical examination shows no abnormalities. On mental status examination, she is tired and has a flattened affect. Cognition is intact. Which of the following is the most appropriate initial step in management?

Question: Which of the following is the most appropriate initial step in management?

Answer:
Assess for suicidal ideation
"


Context: A 14-year-old boy is brought to the physician by his parents for a well-child visit. The patient was born at 38 weeks' gestation via vaginal delivery and has been healthy. He attends a junior high school and is having difficulties keeping up with his classmates in many classes. He is at the 97th percentile for height and 50th percentile for weight. Vital signs are within normal limits. Cardiac examination shows a high-frequency midsystolic click that is best heard at the left fifth intercostal space. The patient has long extremities along with excess breast tissue bilaterally. He has no axillary hair. Genital examination shows reduced scrotal size and a normal sized penis. Which of the following tests is the most likely to diagnose the patient's underlying disorder?

Question: Which of the following tests is the most likely to diagnose the patient's underlying disorder?

Answer: Karyotyping


Context:
A 37-year-old man is brought to the emergency department following a motor vehicle collision. His temperature is 38.1°C (100.6°F), pulse is 39/min, respirations are 29/min, and blood pressure is 58/42 mm Hg. There is no improvement in his blood pressure despite adequate fluid resuscitation. A drug is administered that causes increased IP3 concentrations in arteriolar smooth muscle cells and increased cAMP concentrations in cardiac myocytes. This drug only has a negligible effect on cAMP concentration in bronchial smooth muscle cells. Which of the following sets of cardiovascular changes is most likely following administration of this drug?
 $$$ Cardiac output %%% Mean arterial pressure %%% Systemic vascular resistance $$$

Question: $$$ Cardiac output %%% Mean arterial pressure %%% Systemic vascular resistance $$$

Answer: No change ↑ ↑


Context: A 57-year-old man is brought to the emergency department by his family because of several episodes of vomiting of blood in the past 24 hours. He has a history of alcoholic cirrhosis and is being treated for ascites with diuretics and for encephalopathy with lactulose. His vital signs include a temperature of 36.9°C (98.4°F), pulse of 85/min, and blood pressure of 80/52 mm Hg. On examination, he is confused and unable to give a complete history. He is noted to have jaundice, splenomegaly, and multiple spider angiomas over his chest. Which of the following is the best initial management of this patient?

Question: Which of the following is the best initial management of this patient?

Answer: Combined vasoactive and endoscopic therapy


Context: A 3-year-old boy is brought to his pediatrician by his mother when he developed redness, burning, itching, and exquisite pain all over his arms, lower legs, neck, and face. The mother states that she just recently began taking him to the local playground in the afternoons. She reports that she applied liberal amounts of sunscreen before and during the time outside. She states that they were at the playground for 30 minutes to 1 hour each day for the last 3 days. The patient has experienced prior episodes of redness and pain after being outdoors, but they were relatively minor and resolved within 12 hours. She says his current presentation is much more severe with more exquisite pain than in the past. The patient's vital signs are as follows: T 37.2 C, HR 98, BP 110/62, RR 16, and SpO2 99%. Physical examination reveals edema, erythema, and petechiae over the patient's face, neck, arms, and lower legs. No blistering or scarring of the skin is noted. Which of the following is the best treatment option for this patient's condition?

Question: Which of the following is the best treatment option for this patient's condition?

Answer: Initiate oral beta carotene


Context: An 8-month-old boy presents with poor feeding. The patient’s mother says that he has refused to eat since yesterday morning. She also noticed that he has had trouble keeping his head up and appears floppy. She had breastfed him exclusively and just recently introduced him to pureed foods. His last bowel movement was 3 days ago which was normal. Past medical history is significant for recent otitis media. No current medications except for herbal supplements administered by his parents. Patient is not immunized due to the parent’s religious beliefs. The vital signs include: temperature 37.0°C (98.6°F), blood pressure 85/45 mm Hg, pulse 140/min, respiratory rate 31/min, and oxygen saturation 99% on room air. On physical examination, the patient is lethargic and drooling. Flaccid muscle tone present in all extremities. There is bilateral ptosis with sluggish pupillary reflexes. Which of the following best describes the pathophysiology of this patient’s condition?

Question: Which of the following best describes the pathophysiology of this patient’s condition?

Answer: Ingestion of a preformed toxin


Context: A 72-year-old man is brought into clinic by his daughter for increasing confusion. The daughter states that over the past 2 weeks, she has noticed that the patient “seems to stare off into space.” She reports he has multiple episodes a day during which he will walk into a room and forget why. She is also worried about his balance. She endorses that he has had several falls, the worst being 3 weeks ago when he tripped on the sidewalk getting the mail. The patient denies loss of consciousness, pre-syncope, chest pain, palpitations, urinary incontinence, or bowel incontinence. He complains of headache but denies dizziness. He reports nausea and a few episodes of non-bloody emesis but denies abdominal pain, constipation, or diarrhea. The patient’s medical history is significant for atrial fibrillation, diabetes, hypertension, hyperlipidemia, and osteoarthritis. He takes aspirin, warfarin, insulin, lisinopril, simvastatin, and ibuprofen. He drinks a half glass of whisky after dinner every night and smokes a cigar on the weekends. On physical examination, he is oriented to name and place but not to date. He is unable to spell "world" backward. When asked to remember 3 words, he recalls only 2. There are no motor or sensory deficits. Which of the following is the most likely diagnosis?

Question: Which of the following is the most likely diagnosis?

Answer: Subdural hematoma


Context: A 3-year-old girl is brought to the physician by her parents because of a barking cough, a raspy voice, and noisy breathing for the last 3 days. Five days ago, she had a low-grade fever and runny nose. She attends daycare. Her immunizations are up-to-date. Her temperature is 37.8°C (100°F) and respirations are 33/min. Physical examination shows supraclavicular retractions. There is a high-pitched sound present on inspiration. Examination of the throat shows erythema without exudates. Which of the following is the most likely location of the anatomic narrowing causing this patient's symptoms?

Question: Which of the following is the most likely location of the anatomic narrowing causing this patient's symptoms?

Answer: Subglottic larynx


Context: A student health coordinator plans on leading a campus-wide HIV screening program that will be free for the entire undergraduate student body. The goal is to capture as many correct HIV diagnoses as possible with the fewest false positives. The coordinator consults with the hospital to see which tests are available to use for this program. Test A has a sensitivity of 0.92 and a specificity of 0.99. Test B has a sensitivity of 0.95 and a specificity of 0.96. Test C has a sensitivity of 0.98 and a specificity of 0.93. Which of the following testing schemes should the coordinator pursue?

Question: Which of the following testing schemes should the coordinator pursue?

Answer: Test C on the entire student body followed by Test A on those who are positive


Context: A 40-year-old man is brought into the emergency department because he was involved in a bar fight and sustained an injury to the head. The next day, as requested by the patient, the psychiatry team is called to address some of the concerns he has regarding his drinking habits. He admits that he got irate last night at the bar because his driver’s license was recently taken away and his wife had taken his children to live with her parents because of his drinking problem. He drinks 4–6 beers on a weeknight and more on the weekends. He wants to know if there is anything that could help him at this point. Which stage of overcoming his addiction is this patient currently in?

Question: Which stage of overcoming his addiction is this patient currently in?

Answer: Preparation


Context: A 30-year-old woman presents with generalized fatigue, joint pain, and decreased appetite. She says that symptoms onset a year ago and have not improved. The patient’s husband says he has recently noticed that her eyes and skin are yellowish. The patient denies any history of smoking or alcohol use, but she admits to using different kinds of intravenous illicit drugs during her college years. The patient is afebrile and vital signs are within normal limits. Physical examination is unremarkable, except for moderate scleral icterus. A polymerase chain reaction (PCR) of a blood sample is positive for a viral infection that reveals a positive-sense RNA virus, that is small, enveloped, and single-stranded. The patient is started on a drug that resembles a purine RNA nucleotide. She agrees not to get pregnant before or during the use of this medication. Which of the following is the drug that was most likely given to this patient?

Question: Which of the following is the drug that was most likely given to this patient?

Answer: Ribavirin