Context: A 20-year-old man comes to the clinic complaining of shoulder pain for the past week. He is a pitcher for the baseball team at his university and reports that the pain started shortly after a game. The pain is described as achy and dull, intermittent, 7/10, and is concentrated around the right shoulder area. He denies any significant medical history, trauma, fever, recent illness, or sensory changes but endorses some difficulty lifting his right arm. A physical examination demonstrates mild tenderness of the right shoulder. When the patient is instructed to resist arm depression when holding his arms parallel to the floor with the thumbs pointing down, he reports significant pain of the right shoulder. Strength is 4/5 on the right and 5/5 on the left with abduction of the upper extremities. What nerve innervates the injured muscle in this patient?

Question: What nerve innervates the injured muscle in this patient?

Answer: Suprascapular nerve


Context: A 6-year-old boy and his parents present to the emergency department with high-grade fever, headache, and projectile vomiting. The boy was born at 39 weeks gestation via spontaneous vaginal delivery. He is up to date on all vaccines and is meeting all developmental milestones. Past medical history is noncontributory. He has had no sick contacts at school or at home. The family has not traveled out of the area recently. He likes school and playing videogames with his younger brother. Today, his blood pressure is 115/76 mm Hg, heart rate is 110/min, respiratory rate is 22/min, and temperature is 38.4°C (101.2°F). On physical exam, the child is disoriented. Kernig’s sign is positive. A head CT was performed followed by a lumbar puncture. Several aliquots of CSF were distributed throughout the lab. Cytology showed high counts of polymorphs, biochemistry showed low glucose and elevated protein levels, and a gram smear shows gram-positive lanceolate-shaped cocci alone and in pairs. A smear is prepared on blood agar in an aerobic environment and grows mucoid colonies with clearly defined edges and alpha hemolysis. On later evaluation they develop a ‘draughtsman’ appearance. Which one of the following is the most likely pathogen?

Question: Which one of the following is the most likely pathogen?

Answer: Streptococcus pneumoniae


Context: A forty-five-year-old farmer with past medical history of diabetes, hypertension, and glaucoma comes into your emergency room confused, diaphoretic, salivating, vomiting and shedding tears. He has pinpoint pupils. You conclude that he is showing effects of acute organophosphate poisoning. While administering the antidote, you should carefully monitor for which of the following side effects?

Question: While administering the antidote, you should carefully monitor for which of the following side effects?

Answer: Acute closed-angle glaucoma


Context: A 54-year-old man is brought to the emergency department after having been hit by a car while riding his bicycle. He was not wearing a helmet. Despite appropriate life-saving measures, he dies 2 hours later because of a severe intracranial hemorrhage. Autopsy of the heart shows general thickening of the left ventricular wall with narrowing of the ventricular chamber. Which of the following conditions is the most likely underlying cause of the described cardiac changes?

Question: Which of the following conditions is the most likely underlying cause of the described cardiac changes?

Answer: Chronic hypertension


Context: A 25-year-old woman presents her physician with a complaint of feeling tired and low on energy for the past 6 months. She also has noticed she has been having trouble performing daily tasks and at times experiencing near-fainting spells. She has no recollection of similar instances in the past. Her past medical history is insignificant, except for the fact that she has been a strict vegan for the last 5 years. Her vital signs are stable. On physical examination, she is visibly pale and has decreased position and vibratory sensation in her both lower extremities. There is decreased lower limb reflexes with sensation intact. A complete blood count - done last week, - shows hemoglobin of 9.7 g/dL with an MCV of 110 fL. The serum levels of which of the following will most likely aid in the physician’s treatment plan?

Question: The serum levels of which of the following will most likely aid in the physician’s treatment plan?

Answer: Methylmalonic acid


Context: A 30-year old G2P1 woman, currently at 38 weeks estimated gestational age, presents with contractions. She says that she did not have any prenatal care, because she does not have health insurance. Upon delivery, the infant appears jaundiced and has marked hepatosplenomegaly. Serum hemoglobin is 11.6 g/dL and serum bilirubin is 8 mg/dL. The direct and indirect Coombs tests are both positive. The mother has never had a blood transfusion. Her previous child was born healthy with no complications. Which of the following is most consistent with this neonate’s most likely condition?

Question: Which of the following is most consistent with this neonate’s most likely condition?

Answer: The mother generated IgG antibodies against fetal red blood cells


Context: A 39-year-old female with poorly controlled systemic lupus erythematosus (SLE) presents to the emergency room with a cough and pleuritic chest pain. She states that she developed these symptoms 2 days prior. The pain appears to improve when the patient leans forward. She currently takes hydroxychloroquine for her systemic lupus erythematosus but has missed several doses recently. Her temperature is 99°F (37.2°C), blood pressure is 135/80 mmHg, pulse is 115/min, and respirations are 22/min. Physical examination reveals a rise in jugular venous pressure during inspiration. In addition to tachycardia, which of the following EKG patterns is most likely to be seen in this patient?

Question: In addition to tachycardia, which of the following EKG patterns is most likely to be seen in this patient?

Answer: PR depressions and diffuse ST elevations


Context: A 32-year-old male patient presents to the emergency department after being found down on a sidewalk. He is able to be aroused but seems confused and confabulates extensively during history taking. Physical exam of the eye reveals nystagmus and the patient is unable to complete finger-to-nose or heel-to-shin testing. Chart review shows that the patient is well known for a long history of alcohol abuse. Which of the following substances should be administered prior to giving IV glucose to this patient?

Question: Which of the following substances should be administered prior to giving IV glucose to this patient?

Answer: Vitamin B1


Context: A 6-month-old boy is referred to a geneticist after he is found to have persistent hypotonia and failure to thrive. He has also had episodes of what appears to be respiratory distress and has an enlarged heart on physical exam. There is a family history of childhood onset hypertrophic cardiomyopathy, so a biopsy is performed showing electron dense granules within the lysosomes. Genetic testing is performed showing a defect in glycogen processing. A deficiency in which of the following enzymes is most likely to be responsible for this patient's symptoms?

Question: A deficiency in which of the following enzymes is most likely to be responsible for this patient's symptoms?

Answer: Lysosomal alpha 1,4-glucosidase


Context: A 68-year-old man is brought to the physician by his wife because she is concerned about his speech being irregular. Specifically, she says that over the last 8 months, her husband has been saying increasingly nonsensical statements at home. In addition, he is no longer able to perform basic verbal tasks such as ordering from a menu or giving directions even though he was an English teacher prior to retirement. She also reports that he has recently started attempting to kiss strangers and urinate in public. Finally, she has also noticed that he has been frequently binge eating sweets even though he was previously very conscientious about his health. When asked about these activities, the patient does not have insight into his symptoms. Which of the following would most likely be seen in this patient?

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

Answer: Hyperphosphorylated tau inclusion bodies


Context: A 3-year-old boy is brought to your pediatrics office by his parents for a well-child checkup. The parents are Amish and this is the first time their child has seen a doctor. His medical history is unknown, and he was born at 39 weeks gestation. His temperature is 98.3°F (36.8°C), blood pressure is 97/58 mmHg, pulse is 90/min, respirations are 23/min, and oxygen saturation is 99% on room air. The child is in the corner stacking blocks. He does not look the physician in the eye nor answer your questions. He continually tries to return to the blocks and becomes very upset when you move the blocks back to their storage space. The parents state that the child has not begun to speak and often exhibits similar behaviors with toy blocks he has at home. On occasion, they have observed him biting his elbows. Which of the following is the best next step in management?

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

Answer: Hearing exam


Context: A 26-year-old primigravid woman at 39 weeks' gestation is admitted to the hospital in active labor. Pregnancy was complicated by mild oligohydramnios detected a week ago, which was managed with hydration. Her pulse is 92/min, respirations are 18/min, and blood pressure is 134/76 mm Hg. Pelvic examination shows 100% cervical effacement and 10 cm cervical dilation; the vertex is at 0 station. Cardiotocography is shown. 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: Maternal repositioning and oxygen administration


Context: A 22-year-old sexually active female presents to the emergency department in severe pain. She states that she has significant abdominal pain that seems to worsen whenever she urinates. This seems to have progressed over the past day and is accompanied by increased urge and frequency. The emergency room physician obtains a urinalysis which demonstrates the following: SG: 1.010, Leukocyte esterase: Positive, Protein: Trace, pH: 7.5, RBC: Negative. Nitrite: Negative. A urease test is performed which is positive. What is most likely cause of UTI in this patient?

Question: What is most likely cause of UTI in this patient?

Answer: Staphylococcus saprophyticus


Context:
A 10-year-old boy is brought to the emergency department due to vomiting and weakness. He is attending a summer camp and was on a hike with the other kids and a camp counselor. His friends say that the boy skipped breakfast, and the counselor says he forgot to pack snacks for the kids during the hike. The child’s parents are contacted and report that the child has been completely healthy since birth. They also say there is an uncle who would have to eat regularly or he would have similar symptoms. At the hospital, his heart rate is 90/min, respiratory rate is 17/min, blood pressure is 110/65 mm Hg, and temperature is 37.0°C (98.6°F). Physical examination reveals a visibly lethargic child with slight disorientation to time and place. Mild hepatosplenomegaly is observed but no signs of dehydration are noted. A blood sample is drawn, and fluids are started via an intravenous line.
Lab report
Serum glucose 44 mg/dL
Serum ketones absent
    Serum creatinine 1.0 mg/dL
Blood urea nitrogen 32 mg/dL
    Alanine aminotransferase (ALT) 425 U/L
Aspartate aminotransferase (AST)  372 U/L
    Hemoglobin (Hb%) 12.5 g/dL
Mean corpuscular volume (MCV) 80 fl
Reticulocyte count 1%
Erythrocyte count 5.1 million/mm3
Which of the following is most likely deficient in this patient?

Question:
Lab report
Serum glucose 44 mg/dL
Serum ketones absent
    Serum creatinine 1.0 mg/dL
Blood urea nitrogen 32 mg/dL
    Alanine aminotransferase (ALT) 425 U/L
Aspartate aminotransferase (AST)  372 U/L
    Hemoglobin (Hb%) 12.5 g/dL
Mean corpuscular volume (MCV) 80 fl
Reticulocyte count 1%
Erythrocyte count 5.1 million/mm3
Which of the following is most likely deficient in this patient?

Answer: Acyl-CoA dehydrogenase


Context: A middle aged man is brought in by emergency medical services after being found unconscious, lying on the street next to an empty bottle of vodka. His past medical history is unknown. Upon evaluation, he opens his eyes spontaneously and is able to obey commands. After peripheral access is obtained, IV normal saline and glucose are administered. Suddenly, the patient becomes confused and agitated. Horizontal nystagmus is noted on exam. This acute presentation was likely caused by a deficiency in which of the following?

Question: This acute presentation was likely caused by a deficiency in which of the following?

Answer: Vitamin B1


Context: A 22-year-old woman is brought to the physician by her husband because of a gradual 20-kg (45-lb) weight loss and recurrent episodes of vomiting without diarrhea over the past 2 years. Her last menstrual period was 6 months ago. On physical examination, she appears fatigued and emaciated, and there is bilateral swelling of the retromandibular fossa. Laboratory studies show hypokalemia and a hemoglobin concentration of 8 g/dL. Which of the following additional findings is most likely in this patient?

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

Answer: Decreased triiodothyronine


Context: A 32-year-old man presents to the physician with a history of fever, malaise, and arthralgia in the large joints for the last 2 months. He also mentions that his appetite has been significantly decreased during this period, and he has lost considerable weight. He also informs the physician that he often experiences tingling and numbness in his right upper limb, and his urine is also dark in color. The past medical records show that he was diagnosed with an infection 7 months before and recovered well. On physical examination, the temperature is 37.7°C (99.8°F), the pulse rate is 86/min, the respiratory rate is 14/min, and the blood pressure is 130/94 mm Hg. Which of the following infections has most likely caused the condition the patient is suffering from?

Question: Which of the following infections has most likely caused the condition the patient is suffering from?

Answer: Hepatitis B virus


Context: A 20-year-old man presents to his physician with diarrhea, vomiting, and fever for the past 2 days. After laboratory evaluation, he is diagnosed with bacterial gastroenteritis. The man is a microbiology major and knows that the human gastrointestinal tract, respiratory tract, and skin are lined by epithelia which act as a barrier against several infective microorganisms. He also knows that there are specific T cells in these epithelia that play a part in innate immunity and in recognition of microbial lipids. Which of the following types of T cells is the man thinking of?

Question: Which of the following types of T cells is the man thinking of?

Answer: γδ T cells


Context: A 28-year-old man presents with a yellow coloration of his skin. He says he feels well and denies any recent history of nausea, fatigue or fever, or discoloration of his urine or stool. The patient reports episodes with similar symptoms in the past. Family history is significant for similar symptoms in his father. The patient is afebrile and vital signs are within normal limits. On physical examination, he is jaundiced. Scleral icterus is present. Laboratory findings are significant only for an unconjugated hyperbilirubinemia. Liver enzymes are normal, and there is no bilirubin present in the urine. Which of the following is the most appropriate treatment for this patient’s most likely diagnosis?

Question: Which of the following is the most appropriate treatment for this patient’s most likely diagnosis?

Answer: No therapy indicated


Context: A 5-month-old boy is brought to the physician by his mother because of poor weight gain and chronic diarrhea. He has had 3 episodes of otitis media since birth. Pregnancy and delivery were uncomplicated but his mother received no prenatal care. His immunizations are up-to-date. He is at the 10th percentile for height and 5th percentile for weight. Physical examination shows thick white plaques on the surface of his tongue that can be easily scraped off with a tongue blade. Administration of which of the following is most likely to have prevented this patient's condition?

Question: Administration of which of the following is most likely to have prevented this patient's condition?

Answer: Zidovudine


Context: In the coronary steal phenomenon, vessel dilation is paradoxically harmful because blood is diverted from ischemic areas of the myocardium. Which of the following is responsible for the coronary steal phenomenon?

Question: Which of the following is responsible for the coronary steal phenomenon?

Answer: Microvessel dilation


Context: A 15-year-old boy is brought to the emergency department one hour after sustaining an injury during football practice. He collided head-on into another player while wearing a mouthguard and helmet. Immediately after the collision he was confused but able to use appropriate words. He opened his eyes spontaneously and followed commands. There was no loss of consciousness. He also had a headache with dizziness and nausea. He is no longer confused upon arrival. He feels well. Vital signs are within normal limits. He is fully alert and oriented. His speech is organized and he is able to perform tasks demonstrating full attention, memory, and balance. Neurological examination shows no abnormalities. There is mild tenderness to palpation over the crown of his head but no signs of skin break or fracture. Which of the following is the most appropriate next step?

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

Answer: Observe for 6 hours in the ED and refrain from contact sports for one week


Context: A 26-year-old woman comes to the emergency department 30 minutes after she was bitten by her neighbor's cat. She has no history of serious illness and takes no medications. She received all recommended immunizations during childhood but has not received any since then. Vital signs are within normal limits. Physical examination shows four puncture wounds on the thenar eminence of the right hand. There is mild swelling but no erythema. There is normal range of motion of her right thumb and wrist. The wound is cleaned with povidone iodine and irrigated with saline. 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: Administer oral amoxicillin-clavulanate


Context: An 11-month-old boy is brought to the pediatrician by his mother due to fever and tugging at his right ear. The mother says that he is currently irritable with a mild fever. About 1 week ago, he had a mild cough, mild fever, body aches,  and a runny nose. He was treated with children’s Tylenol and the symptoms resolved after a few days. The child lives in an apartment with his mother, grandmother, and father. His grandmother watches him during the day. There have been no sick contacts at home. His father smokes cigarettes on the balcony. There is no pertinent family history. He was born full term by spontaneous vaginal delivery. He is progressing through his developmental milestones and is up to date on his vaccines. His temperature is 39.3°C (102.7°F), pulse is 122/min, and respirations are 24 /min. The child appears cranky and requires consoling during the physical exam. His heart and lung exam are normal. He has a red and mildly swollen right ear. Otoscopic evaluation of the right ear reveals the finding shown in the image below. Which of the following most likely contributed to this patient’s condition?

Question: Which of the following most likely contributed to this patient’s condition?

Answer: Second hand smoke


Context: A 43-year-old male is transferred from an outside hospital to the neurologic intensive care unit for management of a traumatic brain injury after suffering a 30-foot fall from a roof-top. He now lacks decision-making capacity but does not fulfill the criteria for brain-death. The patient does not have a living will and did not name a specific surrogate decision-maker or durable power of attorney. Which of the following would be the most appropriate person to name as a surrogate decision maker for this patient?

Question: Which of the following would be the most appropriate person to name as a surrogate decision maker for this patient?

Answer: The patient's 22-year-old daughter


Context: A previously healthy 33-year-old woman comes to the emergency department because she could feel her heart racing intermittently for the last 2 hours. Each episode lasts about 10 minutes. She does not have any chest pain. Her mother died of a heart attack and her father had an angioplasty 3 years ago. She has smoked a half pack of cigarettes daily for 14 years. She drinks one to two beers daily. She appears anxious. Her temperature is 37.6°C (98.1°F), pulse is 160/min, and blood pressure is 104/76 mm Hg. The lungs are clear to auscultation. Cardiac examination shows no murmurs, rubs, or gallops. An ECG is shown. 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: Vagal maneuvers


Context: A 19-year-old female presents with a malodorous vaginal discharge. She notes that the odor is more prominent after sexual intercourse. She is sexually active with one partner and uses barrier contraception. Her past medical history is significant only for community-acquired pneumonia treated with antibiotics 2 months ago. The vital signs were as follows: blood pressure, 110/70 mm Hg; heart rate, 68/min; respiratory rate, 12/min; and temperature, 36.6℃ (97.9℉). The physical examination was normal. On gynecologic examination, the vaginal walls and cervix appeared normal. There was a gray, thin, homogeneous discharge with bubbles. The pH of the discharge was approximately 6.0. Which of the following findings would be expected on further investigation of this patient?

Question: Which of the following findings would be expected on further investigation of this patient?

Answer: Bacteria-coated epithelial cells on wet mount microscopy


Context: A 42-year-old man presents to the clinic for a several-month history of fatigue, and it is starting to affect his work. He often needs to sneak away in the middle of the day to take naps or else he cannot focus and is at risk of falling asleep at his desk. He has been feeling like this for approximately 1 year. Otherwise, he feels healthy and takes no medications. On further questioning, he also had constipation and thinks he has gained some weight. He denies shortness of breath, chest pain, lightheadedness, or blood in his stool. The vital signs include: pulse 56/min, blood pressure 124/78 mm Hg, and oxygen saturation 99% on room air. The physical exam is notable only for slightly dry skin. The complete blood count (CBC) is within normal limits, and the thyroid-stimulating hormone (TSH) is 8.0 μU/mL. Which of the following is the next best treatment for this patient?

Question: Which of the following is the next best treatment for this patient?

Answer: Levothyroxine


Context: A 22-year-old primigravid woman at 41 weeks' gestation is admitted to the hospital in active labor. Pregnancy has been uncomplicated. She has asthma treated with theophylline and inhaled corticosteroids. She has had 2 surgeries in the past to repair multiple lower limb and pelvis fractures that were the result of a car accident. She is otherwise healthy. Her temperature is 37.2°C (99°F) and blood pressure is 108/70 mm Hg. Examination shows the cervix is 100% effaced and 10 cm dilated; the vertex is at -4 station, with the occiput in the anterior position. Uterine activity is measured at 275 MVUs. Maternal pushing occurs during the contractions. Fetal heart tracing is 166/min and reactive with no decelerations. Epidural anesthesia is initiated for pain relief. After 4 hours of pushing, the vertex is found to be at -4 station, with increasing strength and rate of uterine contractions; fetal heart tracing shows late decelerations. Which of the following is the most likely cause of this patient's prolonged labor?

Question: Which of the following is the most likely cause of this patient's prolonged labor?

Answer: Cephalopelvic disproportion


Context: A senior medicine resident receives negative feedback on a grand rounds presentation from his attending. He is told sternly that he must improve his performance on the next project. Later that day, he yells at his medical student for not showing enough initiative, though he had voiced only satisfaction with the student's performance up until this point. Which of the following psychological defense mechanisms is he demonstrating?

Question: Which of the following psychological defense mechanisms is he demonstrating?

Answer: Displacement


Context: A 33-year-old man visits his psychiatrist with feelings of sadness on most days of the week for the past 4 weeks. He says that he is unable to participate in his daily activities and finds it hard to get out of bed on most days. If he has nothing scheduled for the day, he sometimes sleeps for 10–12 hours at a stretch. He has also noticed that on certain days, his legs feel heavy and he finds it difficult to walk, as though there are bricks tied to his feet. However, he is still able to attend social events and also enjoys playing with his children when he comes home from work. Other than these simple pleasures, he has lost interest in most of the activities he previously enjoyed. Another troubling fact is that he had gained weight over the past month, mainly because he eats so much when overcome by these feelings of depression. His is prescribed a medication to treat his symptoms. Which of the following is the mechanism of action of the drug he was most likely prescribed?

Question: Which of the following is the mechanism of action of the drug he was most likely prescribed?

Answer: Non-selectively inhibits monoamine oxidase A and B


Context: A 27-year-old man presents to the emergency department for altered mental status. The patient was found napping in a local market and brought to the hospital. The patient has a past medical history of polysubstance abuse and is homeless. His temperature is 104°F (40.0°C), blood pressure is 100/52 mmHg, pulse is 133/min, respirations are 25/min, and oxygen saturation is 99% on room air. Physical exam is notable for an altered man. Cardiopulmonary exam reveals a murmur over the left lower sternal border. A bedside ultrasound reveals a vegetation on the tricuspid valve. The patient is ultimately started on IV fluids, norepinephrine, vasopressin, vancomycin, and piperacillin-tazobactam. A central line is immediately placed in the internal jugular vein and the femoral vein secondary to poor IV access. Cardiothoracic surgery subsequently intervenes to remove the vegetation. While recovering in the ICU, days 3-5 are notable for an improvement in the patient’s symptoms. Two additional peripheral IVs are placed while in the ICU on day 5, and the femoral line is removed. On day 6, the patient's fever and hemodynamic status worsen. Though he is currently responding and not complaining of any symptoms including headache, photophobia, neck stiffness, or pain, he states he is feeling weak. Jolt accentuation of headache is negative and his abdominal exam is benign. A chest radiograph, urinalysis, and echocardiogram are unremarkable though the patient’s blood cultures are positive when drawn. Which of the following is the best next step in management?

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

Answer: Remove the central line and send for cultures


Context: A 25-year-old man is brought to the emergency department by his girlfriend for a nosebleed. Pinching the nose for the past hour has not stopped the bleeding. For the past several months, he has had recurring nosebleeds that resolved with pressure. He has no history of hypertension or trauma. He has asthma that is well controlled with an albuterol inhaler. He has intermittent tension headaches for which he takes aspirin. His temperature is 37.9°C (100.2°F), pulse is 114/min, and blood pressure is 160/102 mm Hg. Physical examination shows active bleeding from both nostrils. Pupil size is 6 mm bilaterally in bright light. The lungs are clear to auscultation. The hemoglobin concentration is 13.5 g/dL, prothrombin time is 12 seconds, partial thromboplastin time is 35 seconds, and platelet count is 345,000/mm3. 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: Cocaine use


Context: A 36-year-old man presents with increasing shortness of breath for a month, which is aggravated while walking and climbing up the stairs. He also complains of pain and stiffness in both wrists, and the distal interphalangeal and metacarpophalangeal joints of both hands. He was diagnosed with rheumatoid arthritis 6 months ago and was started on methotrexate with some improvement. He is a lifetime non-smoker and has no history of drug abuse. The family history is insignificant for any chronic disease. The blood pressure is 135/85 mm Hg, pulse rate is 90/min, temperature is 36.9°C (98.5°F), and the respiratory rate is 22/min. Physical examination reveals short rapid breathing with fine end-inspiratory rales. An echocardiogram is normal with an ejection fraction of 55%. A chest X-ray shows diffuse bilateral reticular markings with multiple pulmonary nodules. Which of the following is the most likely cause of this patient’s lung condition?

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

Answer: Drug-induced pulmonary disease


Context: A 27-year-old man presents to the emergency department after being stabbed. The patient was robbed at a local pizza parlor and was stabbed over 10 times with a large kitchen knife with an estimated 7 inch blade in the ventral abdomen. His temperature is 97.6°F (36.4°C), blood pressure is 74/54 mmHg, pulse is 180/min, respirations are 19/min, and oxygen saturation is 98% on room air. The patient is intubated and given blood products and vasopressors. Physical exam is notable for multiple stab wounds over the patient's abdomen inferior to the nipple line. Which of the following is the best next step in management?

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

Answer: Exploratory laparotomy


Context:
A 37-year-old woman comes to the physician because of irregular menses and generalized fatigue for the past 4 months. Menses previously occurred at regular 25- to 29-day intervals and lasted for 5 days but now occur at 45- to 60-day intervals. She has no history of serious illness and takes no medications. She is 155 cm (5 ft 1 in) tall and weighs 89 kg (196 lb); BMI is 37 kg/m2. Her temperature is 37°C (98.6°F), pulse is 90/min, and blood pressure is 146/100 mm Hg. Examination shows facial hair as well as comedones on the face and back. There are multiple ecchymotic patches on the trunk. Neurological examination shows weakness of the iliopsoas and biceps muscles bilaterally. Laboratory studies show:
Hemoglobin 13.1 g/dL
Leukocyte count 13,500/mm3
Platelet count 510,000/mm3
Serum
Na+ 145 mEq/L
K+ 3.3 mEq/L
Cl- 100 mEq/L
Glucose 188 mg/dL
Which of the following is the most likely diagnosis?"

Question:
Laboratory studies show:
Hemoglobin 13.1 g/dL
Leukocyte count 13,500/mm3
Platelet count 510,000/mm3
Serum
Na+ 145 mEq/L
K+ 3.3 mEq/L
Cl- 100 mEq/L
Glucose 188 mg/dL
Which of the following is the most likely diagnosis?"

Answer: Cushing syndrome


Context:
A 18-year-old male presents to his primary care provider with his parents for a sports physical. He was last seen in clinic several months ago, when he was diagnosed with attention deficit hyperactivity disorder (ADHD). He was started on methylphenidate at that time, and the patient now reports improvement in his ability to concentrate in school and at home. He hopes to play baseball in college and has begun lifting weights daily in preparation for baseball season. The patient reports that he eats a healthy diet to fuel his exercise regimen. His parents have no concerns and are pleased with the recent improvement in his grades. On physical exam, the patient has tall stature with average muscle mass for his age. He has no dysmorphic features. His chest has a normal appearance other than mild gynecomastia. The patient has sparse facial hair and a moderate amount of coarse pubic hair that extends across the pubis and spares the medial thighs. His testes are small and firm. Due to the latter, laboratory testing is performed and reveals the following:

Follicle-stimulating hormone (FSH): 42 mIU/mL (Reference range: 4-25 mIU/mL)
Luteinizing hormone (LH): 38 mIU/mL (Reference range: 6-23 mIU/mL)

Which of the following is the most likely etiology of this patient’s presentation?

Question:
Due to the latter, laboratory testing is performed and reveals the following:

Follicle-stimulating hormone (FSH): 42 mIU/mL (Reference range: 4-25 mIU/mL)
Luteinizing hormone (LH): 38 mIU/mL (Reference range: 6-23 mIU/mL)

Which of the following is the most likely etiology of this patient’s presentation?

Answer: Meiotic nondisjunction


Context: Following passage of a calcium oxalate stone, a 55-year-old male visits his physician to learn about nephrolithiasis prevention. Which of the following changes affecting urine composition within the bladder are most likely to protect against crystal precipitation?

Question: Which of the following changes affecting urine composition within the bladder are most likely to protect against crystal precipitation?

Answer: Decreased calcium, increased citrate, decreased oxalate, increased free water clearance


Context: A 67-year-old woman is brought to the emergency department for the evaluation of fever, chest pain, and a cough productive of a moderate amount of greenish-yellow sputum for 2 days. During this period, she has had severe malaise, chills, and difficulty breathing. She has hypertension, hypercholesterolemia, and type 2 diabetes mellitus. She smoked one pack of cigarettes daily for 20 years, but quit 5 years ago. Current medications include simvastatin, captopril, and metformin. Temperature is 39°C (102.2°F), pulse is 110/min, respirations are 33/min, and blood pressure is 143/88 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 94%. Crackles are heard on auscultation of the right upper lobe. Laboratory studies show a leukocyte count of 12,300/mm3, an erythrocyte sedimentation rate of 60 mm/h, and a urea nitrogen of 15 mg/dL. A chest x-ray is shown. 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: Inpatient treatment with azithromycin and cefotaxime


Context:
A study is conducted to investigate the relationship between the development of type 2 diabetes mellitus and the use of atypical antipsychotic medications in patients with schizophrenia. 300 patients who received the atypical antipsychotic clozapine and 300 patients who received the typical antipsychotic haloperidol in long-acting injectable form were followed for 2 years. At the end of the observation period, the incidence of type 2 diabetes mellitus was compared between the two groups. Receipt of clozapine was found to be associated with an increased risk of diabetes mellitus relative to haloperidol (RR = 1.43, 95% p<0.01).
Developed type 2 diabetes mellitus Did not develop type 2 diabetes mellitus
Clozapine 30 270
Haloperidol 21 279
Based on these results, what proportion of patients receiving clozapine would not have been diagnosed with type 2 diabetes mellitus if they had been taking a typical antipsychotic?"

Question:
Developed type 2 diabetes mellitus Did not develop type 2 diabetes mellitus
Clozapine 30 270
Haloperidol 21 279
Based on these results, what proportion of patients receiving clozapine would not have been diagnosed with type 2 diabetes mellitus if they had been taking a typical antipsychotic?"

Answer: 0.03


Context:
A 44-year-old woman presents to her primary care physician for worsening dysuria, hematuria, and lower abdominal pain. Her symptoms began approximately 2 days ago and have progressively worsened. She denies headache, nausea, vomiting, or diarrhea. She endorses feeling "feverish" and notes to having foul smelling urine. She has a past medical history of Romano-Ward syndrome and is not on any treatment. She experiences profuse diarrhea and nausea when taking carbapenems and develops a severe rash with cephalosporins. Her temperature is 100.4°F (38C), blood pressure is 138/93 mmHg, pulse is 100/min, and respirations are 18/min. On physical exam, the patient appears uncomfortable and there is tenderness to palpation around the bilateral flanks and costovertebral angle. A urinalysis and urine culture is obtained and appropriate antibiotics are administered. On her next clinical visit urine studies and a basic metabolic panel is obtained, which is shown below:

Serum:
Na+: 140 mEq/L
Cl-: 101 mEq/L
K+: 4.2 mEq/L
HCO3-: 22 mEq/L
BUN: 20 mg/dL
Glucose: 94 mg/dL
Creatinine: 2.4 mg/dL

Urinalysis
Color: Yellow
Appearance: Clear
Blood: Negative
pH: 7 (Normal 5-8)
Protein: Negative
Nitrite: Negative
Leukocyte esterase: Negative
Cast: Epithelial casts
FeNa: 3%

Urine culture
Preliminary report: 10,000 CFU/mL E. coli

Which of the following antibiotics was most likely given to this patient?

Question:
On her next clinical visit urine studies and a basic metabolic panel is obtained, which is shown below:

Serum:
Na+: 140 mEq/L
Cl-: 101 mEq/L
K+: 4.2 mEq/L
HCO3-: 22 mEq/L
BUN: 20 mg/dL
Glucose: 94 mg/dL
Creatinine: 2.4 mg/dL

Urinalysis
Color: Yellow
Appearance: Clear
Blood: Negative
pH: 7 (Normal 5-8)
Protein: Negative
Nitrite: Negative
Leukocyte esterase: Negative
Cast: Epithelial casts
FeNa: 3%

Urine culture
Preliminary report: 10,000 CFU/mL E. coli

Which of the following antibiotics was most likely given to this patient?

Answer: Tobramycin


Context: A 58-year-old man presents to the physician due to difficulty initiating and sustaining erections for the past year. According to the patient, he has a loving wife and he is still attracted to her sexually. While he still gets an occasional erection, he has not been able to maintain an erection throughout intercourse. He no longer gets morning erections. He is happy at work and generally feels well. His past medical history is significant for angina and he takes isosorbide dinitrate as needed for exacerbations. His pulse is 80/min, respirations are 14/min, and blood pressure is 130/90 mm Hg. The physical examination is unremarkable. Nocturnal penile tumescence testing reveals the absence of erections during the night. The patient expresses a desire to resume sexual intimacy with his spouse. Which of the following is the best next step to treat this patient?

Question: Which of the following is the best next step to treat this patient?

Answer: Check prolactin levels


Context: A 3-year-old girl is brought to the physician because of a cough for 2 days. The cough occurs as paroxysmal spells, with vomiting sometimes occurring afterwards. She takes a deep breath after these spells that makes a whooping sound. She has been unable to sleep well because of the cough. She had a runny nose and low-grade fever 1 week ago. She was admitted at the age of 9 months for bronchiolitis. Her immunizations are incomplete, as her parents are afraid of vaccine-related complications. She attends a daycare center but there have been no other children who have similar symptoms. She appears well. Cardiopulmonary examination shows no abnormalities. Her hemoglobin concentration is 13.3 g/dL, leukocyte count is 41,000/mm3, platelet count is 230,000/mm3 and erythrocyte sedimentation rate is 31 mm/hr. An x-ray of the chest is unremarkable. The patient is at increased risk for which of the following complications?

Question: The patient is at increased risk for which of the following complications?

Answer: Pneumothorax


Context:
A 34-year-old man is brought to the emergency room by emergency medical technicians after being found unconscious near a park bench. He appears disheveled with a strong odor of alcohol. There is no known past medical history other than treatment for alcohol withdrawal in the past at this institution.The patient is laying on the stretcher with altered mental status, occasionally muttering a few words that are incomprehensible to the examiner. Physical examination reveals a heart rate of 94/min, blood pressure of 110/62 mm Hg, respiratory rate of 14/min, and temperature is 37.0°C (98.6°F). The patient’s physical exam is otherwise unremarkable with lungs clear to auscultation, a soft abdomen, and no skin rashes. Initial laboratory findings reveal:
Blood glucose 56 mg/dL
Blood alcohol level 215 mg/dL
Hemoglobin 10.9 g/dL
WBC 10,000/mm3
Platelets 145,000/mm3
Lactate level
2.2 mmol/L
Which of the following describes the most likely physiological factor underlying the patient’s hypoglycemia?

Question:
Initial laboratory findings reveal:
Blood glucose 56 mg/dL
Blood alcohol level 215 mg/dL
Hemoglobin 10.9 g/dL
WBC 10,000/mm3
Platelets 145,000/mm3
Lactate level
2.2 mmol/L
Which of the following describes the most likely physiological factor underlying the patient’s hypoglycemia?

Answer: Glycogen depletion


Context: A 68-year-old man is admitted to the emergency department after 2 days of difficulty breathing and fever. His past medical history is significant for hypertension and benign prostate hypertrophy. He takes hydrochlorothiazide and tamsulosin.  He also admits to drinking alcohol on the weekends and a half pack a day smoking habit. Upon admission, he is found to have blood pressure of 125/83 mm Hg, pulse of 88/min, a respiratory rate of 28/min, and a temperature of 38.9°C (102°F). On physical exam breath sounds are decreased at the left pulmonary base. A chest x-ray reveals consolidation in the left lower lobe. Additional laboratory tests demonstrate leukocytosis, elevated C-reactive protein, a serum creatinine (Cr) of 8.0 mg/dL, and a blood urea nitrogen (BUN) of 32 mg/dL. The patient is admitted to the hospital and started on cefepime and clarithromycin. His dyspnea slowly improves after 48 hours, however, his body temperature remains at 39°C (102.2°F). Recent laboratory tests show reduced C-reactive protein levels, a Cr of 1.8 mg/dL and a BUN of 35 mg/dL. A urinalysis is ordered. Which of the following would you expect to find in this patient’s urine?

Question: Which of the following would you expect to find in this patient’s urine?

Answer: White blood cell casts


Context: A 29-year-old man comes to the emergency department because of progressively worsening fatigue and shortness of breath for the past 2 weeks. His only medication is insulin. Examination shows elevated jugular venous distention and coarse crackles in both lungs. Despite appropriate life-saving measures, he dies. Gross examination of the heart at autopsy shows concentrically thickened myocardium and microscopic examination shows large cardiomyocytes with intracellular iron granules. Examination of the spinal cord shows atrophy of the lateral corticospinal tracts, spinocerebellar tracts, and dorsal columns. Which of the following is the most likely underlying cause of this patient's condition?

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

Answer: GAA trinucleotide repeat expansion on chromosome 9


Context: A 51-year-old woman comes to the physician because of a 3-month history of fatigue, increased urinary frequency, and low back pain. She reports frequent passing of hard stools, despite using stool softeners. During this time, she has not been as involved with her weekly book club. Her family is concerned that she is depressed. She has no history of serious illness. She has smoked 1 pack of cigarettes daily for the past 20 years. Her pulse is 71/min and blood pressure is 150/90 mm Hg. Abdominal examination shows right costovertebral angle tenderness. The patient's symptoms are most likely caused by hyperplasia of which of the following?

Question: The patient's symptoms are most likely caused by hyperplasia of which of the following?

Answer: Chief cells in the parathyroid gland


Context: A 43-year-old woman comes to the physician because of a 3-month history of increased flow and duration of her menses. Menses previously occurred at regular 28-day intervals and lasted 5 days with normal flow. They now last 8–9 days and the flow is heavy with the passage of clots. During this period, she has also had lower abdominal pain that begins 2–3 days prior to onset of her menses and lasts for 2 days after the end of her menses. She has three children. Her mother died of endometrial cancer at the age of 61 years. Her temperature is 37°C (98.6°F), pulse is 86/min, and blood pressure is 110/70 mm Hg. Pelvic examination shows a uniformly enlarged, boggy uterus consistent in size with an 8-week gestation that is tender on palpation. A urine pregnancy test is negative. Which of the following is the most likely cause of this patient's findings?

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

Answer: Endometrial tissue within the uterine wall


Context:
A 54-year-old man comes to the emergency department because of abdominal distension for the past 3 weeks. He also complains of generalized abdominal discomfort associated with nausea and decreased appetite. He was discharged from the hospital 3 months ago after an inguinal hernia repair with no reported complications. He has a history of type 2 diabetes mellitus, congestive heart failure, and untreated hepatitis C. His current medications include aspirin, atorvastatin, metoprolol, lisinopril, and metformin. His father has a history of alcoholic liver disease. He has smoked one pack of cigarettes daily for 30 years but quit 5 years ago. He drinks 3–4 beers daily. He appears cachectic. His vital signs are within normal limits. Examination shows a distended abdomen and shifting dullness. There is no abdominal tenderness or palpable masses. There is a well-healed surgical scar in the right lower quadrant. Examination of the heart and lung shows no abnormalities. He has 1+ bilateral lower extremity nonpitting edema. Diagnostic paracentesis is performed. Laboratory studies show:
Hemoglobin 10 g/dL
Leukocyte count 14,000/mm3
Platelet count 152,000/mm3
Serum
Total protein 5.8 g/dL
Albumin 3.5 g/dL
AST 18 U/L
ALT 19 U/L
Total bilirubin 0.8 mg/dL
HbA1c 8.1%
Peritoneal fluid analysis
Color Cloudy
Cell count 550/mm3 with lymphocytic predominance
Total protein 3.5 g/dL
Albumin 2.6 g/dL
Glucose 60 mg/dL
Triglycerides 360 mg/dL
Peritoneal fluid Gram stain is negative. Culture and cytology results are pending. 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: Lymphoma


Context: A 29-year-old woman presents with a skin rash that has spread on her arm over the last few days. She also complains of fever, headache, joint pain, and stiffness of the neck associated with the onset of the rash. On physical examination, there is an annular, red rash with a clear area in the center similar to a bull’s-eye (see image). The patient says she went on a camping trip to Connecticut last month but does not remember being bitten by an insect. Which of the following could result if this condition remains untreated in this patient?

Question: Which of the following could result if this condition remains untreated in this patient?

Answer: Bell’s palsy


Context:
A 45-year-old man presents to the office with complaints of facial puffiness and mild swelling in his lower back. He denies chest pain, blood in the urine, or fever. He was recently diagnosed with colon cancer. The vital signs include a blood pressure of 122/78 mm Hg, a pulse of 76/min, a temperature of 36.9°C (98.4°F), and a respiratory rate of 10/min. On physical examination, there is mild facial puffiness that is pitting in nature and presacral edema. His other systemic findings are within normal limits.
Urinalysis shows:
pH 6.2
Color light yellow
RBC none
WBC 3–4/HPF
Protein 4+
Cast oval fat bodies
Glucose absent
Crystal none
Ketone absent
Nitrite absent
 24 hours urine protein excretion  4.8 g
A renal biopsy is ordered and diffuse capillary and basement membrane thickening is noted. Which of the following findings is expected to be present if an electron microscopy of the biopsy sample is performed?

Question: Which of the following findings is expected to be present if an electron microscopy of the biopsy sample is performed?

Answer: Spike and dome appearance


Context: A 16-year-old female presents to her pediatrician’s office because she has not yet started menstruating. On review of systems, she states that she has been increasingly tired, constipated, and cold over the last 6 months. She also endorses a long history of migraines with aura that have increased in frequency over the last year. She complains that these symptoms have affected her performance on the track team. She states that she is not sexually active. Her mother and sister both underwent menarche at age 15. The patient is 5 feet, 4 inches tall and weighs 100 pounds (BMI 17.2 kg/m^2). Temperature is 98.4°F (36.9°C), blood pressure is 98/59 mmHg, pulse is 98/min, and respirations are 14/min. On exam, the patient appears pale and has thinning hair. She has Tanner stage IV breasts and Tanner stage III pubic hair. Which of the following would be most useful in determining this patient’s diagnosis?

Question: Which of the following would be most useful in determining this patient’s diagnosis?

Answer: FSH and estrogen levels


Context: An investigator is working with a mutant strain of mice that lack a consistent density of sarcolemmal transverse tubules in the skeletal muscle cells. Which of the following is the most likely associated finding as a result of this abnormality?

Question: Which of the following is the most likely associated finding as a result of this abnormality?

Answer: Impaired synchronization of cross-bridge formation


Context: A 4-year-old male is accompanied by his mother to the pediatrician. His mother reports that over the past two weeks, the child has had intermittent low grade fevers and has been more lethargic than usual. The child’s past medical history is notable for myelomeningocele complicated by lower extremity weakness as well as bowel and bladder dysfunction. He has been hospitalized multiple times at an outside facility for recurrent urinary tract infections. The child is in the 15th percentile for both height and weight. His temperature is 100.7°F (38.2°C), blood pressure is 115/70 mmHg, pulse is 115/min, and respirations are 20/min. Physical examination is notable for costovertebral angle tenderness that is worse on the right. Which of the following would most likely be found on biopsy of this patient’s kidney?

Question: Which of the following would most likely be found on biopsy of this patient’s kidney?

Answer: Tubular colloid casts with diffuse lymphoplasmacytic infiltrate


Context: A 5-month-old girl is brought to the physician with a red lesion on her scalp that was first noticed 2 months ago. The lesion has been increasing in size slowly. It is not associated with pain or pruritus. She was born at 37 weeks of gestation after an uncomplicated pregnancy and delivery. The patient’s older sister is currently undergoing treatment for fungal infection of her feet. Examination reveals a solitary, soft lesion on the vertex of the scalp that blanches with pressure. A photograph of the lesion is shown. 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: Reassurance and follow-up


Context: A 65-year-old man is admitted to the hospital because of a 1-month history of fatigue, intermittent fever, and weakness. Results from a peripheral blood smear taken during his evaluation are indicative of possible acute myeloid leukemia. Bone marrow aspiration and subsequent cytogenetic studies confirm the diagnosis. The physician sets aside an appointed time-slot and arranges a meeting in a quiet office to inform him about the diagnosis and discuss his options. He has been encouraged to bring someone along to the appointment if he wanted. He comes to your office at the appointed time with his daughter. He appears relaxed, with a full range of affect. Which of the following is the most appropriate opening statement in this situation?

Question: Which of the following is the most appropriate opening statement in this situation?

Answer: """What is your understanding of the reasons we did bone marrow aspiration and cytogenetic studies?"""


Context: A 53-year-old homeless woman is brought to the emergency department by the police after she was found in the park lying unconscious on the ground. Both of her pupils are normal in size and reactive to light. There are no signs of head trauma. Finger prick test shows a blood glucose level of 20 mg/dL. She has been brought to the emergency department for acute alcohol intoxication several times before. Her vitals signs include: blood pressure 100/70 mm Hg, heart rate 90/min, respiratory rate 22/min, and temperature 35.0℃ (95.0℉). On general examination, she looks pale, but there is no sign of icterus noted. On physical examination, the abdomen is soft and non-tender and no hepatosplenomegaly noted. She spontaneously opens her eyes after the administration of a bolus of intravenous dextrose, thiamine, and naloxone. Blood and urine samples are drawn for toxicology screening. Finally, the blood alcohol level turns out to be 300 mg/dL. What will be the most likely laboratory findings in this patient?

Question: What will be the most likely laboratory findings in this patient?

Answer: AST > ALT, increased gamma-glutamyl transferase


Context: A 37-year-old woman comes to the physician because of difficulty swallowing for the past 1 year. She was diagnosed with gastroesophageal reflux 3 years ago and takes pantoprazole. She has smoked a pack of cigarettes daily for 14 years. Examination shows hardening of the skin of the fingers and several white papules on the fingertips. There are small dilated blood vessels on the face. Which of the following is the most likely cause of this patient's difficulty swallowing?

Question: Which of the following is the most likely cause of this patient's difficulty swallowing?

Answer: Esophageal smooth muscle fibrosis


Context: A 68-year-old man presents for his first hemodialysis treatment. He was diagnosed with progressive chronic kidney disease 6 years ago that has now resulted in end-stage renal disease (ESRD). He currently is on a waiting list for a kidney transplant. His past medical history is significant for hypertension and peptic ulcer disease, managed with amlodipine and esomeprazole, respectively. He has diligently followed a severely restricted diet. The patient is afebrile and his vital signs are normal. His latest serum creatinine gives him an estimated glomerular filtration rate (eGFR) of 12 mL/min/1.73 m2. Which of the following should be increased as part of the management of this patient?

Question: Which of the following should be increased as part of the management of this patient?

Answer: Protein intake


Context: A 36-year-old woman presents to the outpatient department with a recent onset of generalized weakness and weight gain. On physical examination, there is diffuse nontender enlargement of the thyroid gland. Fine-needle aspiration and cytology show lymphocytic infiltration with germinal centers and epithelial Hürthle cells. Which of the following autoantibodies is most likely to be found in this patient?

Question: Which of the following autoantibodies is most likely to be found in this patient?

Answer: Antimicrosomal antibody


Context: A 27-year-old woman is brought to the office at the insistence of her fiancé to be evaluated for auditory hallucinations for the past 8 months. The patient’s fiancé tells the physician that the patient often mentions that she can hear her own thoughts speaking aloud to her. The hallucinations have occurred intermittently for at least 1-month periods. Past medical history is significant for hypertension. Her medications include lisinopril and a daily multivitamin both of which she frequently neglects. She lost her security job 7 months ago after failing to report to work on time. The patient’s vital signs include: blood pressure 132/82 mm Hg; pulse 72/min; respiratory rate 18/min, and temperature 36.7°C (98.1°F). On physical examination, the patient has a flat affect and her focus fluctuates from the window to the door. She is disheveled with a foul smell. She has difficulty focusing on the discussion and does not quite understand what is happening around her. A urine toxicology screen is negative. Which of the following is the correct diagnosis for this patient?

Question: Which of the following is the correct diagnosis for this patient?

Answer: Schizophrenia


Context: You are seeing an otherwise healthy 66-year-old male in clinic who is complaining of localized back pain and a new rash. On physical exam, his vital signs are within normal limits. You note a vesicular rash restricted to the upper left side of his back. In order to confirm your suspected diagnosis, you perform a diagnostic test. What would you expect to find on the diagnostic test that was performed?

Question: What would you expect to find on the diagnostic test that was performed?

Answer: Multinucleated giant cells


Context: A 54-year-old man comes to the physician for a follow-up examination after presenting with elevated blood pressures on both arms at a routine visit 1 month ago. He feels well and takes no medications. He is 178 cm (5 ft 10 in) tall and weighs 99 kg (218 lb); BMI is 31 kg/m2. His pulse is 76/min, and blood pressure is 148/85 mm Hg on the right arm and 152/87 mm Hg on the left arm. Physical examination and laboratory studies show no abnormalities. The physician recommends lifestyle modifications in combination with treatment with hydrochlorothiazide. From which of the following embryological tissues does the site of action of this drug arise?

Question: From which of the following embryological tissues does the site of action of this drug arise?

Answer: Metanephric blastema


Context: An 18-year-old boy is brought to the emergency department by his parents because he suddenly collapsed while playing football. His parents mention that he had complained of dizziness while playing before, but never fainted in the middle of a game. On physical examination, the blood pressure is 130/90 mm Hg, the respirations are 15/min, and the pulse is 110/min. The chest is clear, but a systolic ejection murmur is present. The remainder of the examination revealed no significant findings. An electrocardiogram is ordered, along with an echocardiogram. He is diagnosed with hypertrophic cardiomyopathy and the physician lists all the precautions he must follow. Which of the following drugs will be on the list of contraindicated substances?

Question: Which of the following drugs will be on the list of contraindicated substances?

Answer: Nitrates


Context: An investigator is studying the crossbridge cycle of muscle contraction. Tissue from the biceps brachii muscle is obtained at the autopsy of an 87-year-old man. Investigation of the muscle tissue shows myosin heads attached to actin filaments. Binding of myosin heads to which of the following elements would most likely cause detachment of myosin from actin filaments?

Question: Binding of myosin heads to which of the following elements would most likely cause detachment of myosin from actin filaments?

Answer: ATP


Context: A 52-year-old man awakens in the middle of the night with excruciating pain in his right great toe. He reports that even the touch of the bed sheet was unbearably painful. His right foot is shown in figure A. He is treated with colchicine. Which of the following describes the mechanism of colchicine?

Question: Which of the following describes the mechanism of colchicine?

Answer: Decreases microtubule polymerization


Context: A 15-year-old boy and his mother were referred to a pulmonology clinic. She is concerned that her son is having some breathing difficulty for the past few months, which is aggravated with exercise. The family is especially concerned because the patient’s older brother has cystic fibrosis. The past medical history is noncontributory. Today, the vital signs include: blood pressure 119/80 mm Hg, heart rate 90/min, respiratory rate 17/min, and temperature 37.0°C (98.6°F). On physical exam, he appears well-developed and well-nourished. The heart has a regular rate and rhythm, and the lungs are clear to auscultation bilaterally. During the exam, he is brought into a special room to test his breathing. A clamp is placed on his nose and he is asked to take in as much air as he can, and then forcefully expire all the air into a spirometer. The volume of expired air represents which of the following?

Question: The volume of expired air represents which of the following?

Answer: Vital capacity


Context: A 39-year-old woman is brought to the emergency department 30 minutes after her husband found her unconscious on the living room floor. She does not report having experienced light-headedness, nausea, sweating, or visual disturbance before losing consciousness. Three weeks ago, she was diagnosed with open-angle glaucoma and began treatment with an antiglaucoma drug in the form of eye drops. She last used the eye drops 1 hour ago. Examination shows pupils of normal size that are reactive to light. An ECG shows sinus bradycardia. This patient is most likely undergoing treatment with which of the following drugs?

Question: This patient is most likely undergoing treatment with which of the following drugs?

Answer: Timolol


Context:
A 30-year-old forest landscape specialist is brought to the emergency department with hematemesis and confusion. One week ago she was diagnosed with influenza when she had fevers, severe headaches, myalgias, hip and shoulder pain, and a maculopapular rash. After a day of relative remission, she developed abdominal pain, vomiting, and diarrhea. A single episode of hematemesis occurred prior to admission. Two weeks ago she visited rainforests and caves in western Africa where she had direct contact with animals, including apes. She has no history of serious illnesses or use of medications. She is restless. Her temperature is 38.0℃ (100.4℉); the pulse is 95/min, the respiratory rate is 20/min; and supine and upright blood pressure is 130/70 mm Hg and 100/65 mm Hg, respectively. Conjunctival suffusion is noted. Ecchymoses are observed on the lower extremities. She is bleeding from one of her intravenous lines. The peripheral blood smear is negative for organisms. Filovirus genomes were detected during a reverse transcription-polymerase chain reaction. The laboratory studies show the following:
Laboratory test
Hemoglobin 10 g/dL
Leukocyte count 1,000/mm3
Segmented neutrophils 65%
Lymphocytes 20%
Platelet count 50,000/mm3
Partial thromboplastin time (activated) 60 seconds
Prothrombin time 25 seconds
Fibrin split products positive
Serum
Alanine aminotransferase (ALT) 85 U/L
Aspartate aminotransferase (AST) 120 U/L
γ-Glutamyltransferase (GGT) 83 U/L
Creatinine 2 mg/dL
Which of the following is the most appropriate immediate step in management?

Question:
The laboratory studies show the following:
Laboratory test
Hemoglobin 10 g/dL
Leukocyte count 1,000/mm3
Segmented neutrophils 65%
Lymphocytes 20%
Platelet count 50,000/mm3
Partial thromboplastin time (activated) 60 seconds
Prothrombin time 25 seconds
Fibrin split products positive
Serum
Alanine aminotransferase (ALT) 85 U/L
Aspartate aminotransferase (AST) 120 U/L
γ-Glutamyltransferase (GGT) 83 U/L
Creatinine 2 mg/dL
Which of the following is the most appropriate immediate step in management?

Answer: Intravenous fluids and electrolytes


Context: You have isolated cells from a patient with an unknown disorder and would like to locate the defect in this patient. When radiolabeled propionate is added to the mitochondria, no radiolabeled carbon dioxide is detected. However, when radiolabeled methylmalonic acid is added, radiolabeled carbon dioxide is detected from these cells. Which of the following amino acids can be fully metabolized by this patient?

Question: Which of the following amino acids can be fully metabolized by this patient?

Answer: Phenylalanine


Context:
A 21-year-old woman is brought to the clinic for evaluation by her brother. The patient’s brother says that, 3 days ago, the patient had put on her best pantsuit and makeup and insisted that she was returning to work and driving to Seattle to take over for the CEO of the Amazon Corporation. He says this was especially odd because her husband was just killed in an automobile accident in a different city 2 days ago. Today, the patient’s brother says she was saddened, wearing grey jogging pants. The patient says she does not recall acting odd and does remember that her husband is dead. Her vital signs include: blood pressure 132/84 mm Hg, pulse 92/min, respiratory rate 16/min, temperature 37.4°C (99.4°F). Upon physical examination, the patient’s affect is saddened but her speech rate and volume are normal. There is no hallucinations, mania, interruptive speech, depressive symptoms, or loss of interest in activities once enjoyed. Results of urine drug screen are provided below:
Amphetamine negative
Benzodiazepine negative
Cocaine negative
GHB negative
Ketamine negative
LSD negative
Marijuana negative
Opioids negative
PCP negative
Which of the following best describes the patient’s state?

Question:
Results of urine drug screen are provided below:
Amphetamine negative
Benzodiazepine negative
Cocaine negative
GHB negative
Ketamine negative
LSD negative
Marijuana negative
Opioids negative
PCP negative
Which of the following best describes the patient’s state?

Answer: Brief psychotic disorder


Context:
A 55-year-old man comes to the physician for a follow-up examination. During the past month, he has had mild itching. He has alcoholic cirrhosis, hypertension, and gastroesophageal reflux disease. He used to drink a pint of vodka and multiple beers daily but quit 4 months ago. Current medications include ramipril, esomeprazole, and vitamin B supplements. He appears thin. His temperature is 36.8°C (98.2°F), pulse is 68/min, and blood pressure is 115/72 mm Hg. Examination shows reddening of the palms bilaterally and several telangiectasias over the chest, abdomen, and back. There is symmetrical enlargement of the breast tissue bilaterally. His testes are small and firm on palpation. The remainder of the examination shows no abnormalities. Laboratory studies show:
Hemoglobin 10.1 g/dL
Leukocyte count 4300/mm3
Platelet count 89,000/mm3
Prothrombin time 11 sec (INR = 1)
Serum
Albumin 3 g/dL
Bilirubin
Total 2.0 mg/dL
Direct 0.2 mg/dL
Alkaline phosphatase 43 U/L
AST 55 U/L
ALT 40 U/L
α-Fetoprotein 8 ng/mL (N < 10)
Anti-HAV IgG antibody positive
Anti-HBs antibody negative
Abdominal ultrasonography shows a nodular liver surface with atrophy of the right lobe of the liver. An upper endoscopy shows no abnormalities. 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: Repeat abdominal ultrasound in 6 months


Context: A newborn infant is born at 40 weeks gestation to a G1P1 mother. The pregnancy was uncomplicated and was followed by the patient's primary care physician. The mother has no past medical history and is currently taking a multi-vitamin, folate, B12, and iron. The infant is moving its limbs spontaneously and is crying. His temperature is 98.7°F (37.1°C), blood pressure is 60/38 mmHg, pulse is 150/min, respirations are 33/min, and oxygen saturation is 99% on room air. Which of the following is the best next step in management?

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

Answer: Intramuscular (IM) vitamin K and topical erythromycin


Context: Researchers are investigating a new strain of a virus that has been infecting children over the past season and causing dermatitis. They have isolated the virus and have run a number of tests to determine its structure and characteristics. They have found that this new virus has an outer coating that is high in phospholipids. Protein targeting assays and immunofluorescence images have shown that the outer layer contains numerous surface proteins. On microscopy, these surface proteins are also expressed around the nucleus of cells derived from the infected tissue of the children. This virus’s structure most closely resembles which of the following?

Question: This virus’s structure most closely resembles which of the following?

Answer: Herpesvirus


Context: A 48-year-old woman is brought to the emergency department by her family at her psychiatrist's recommendation. According to her family, she has been more restless than her baseline over the past week. The patient herself complains that she feels her mind is racing. Her past medical history is significant for bipolar disorder on lithium and type 1 diabetes mellitus. The family and the patient both assert that the patient has been taking her medications. She denies any recent illness or sick contacts. The patient's temperature is 100°F (37.8°C), blood pressure is 100/60 mmHg, pulse is 130/min, and respirations are 20/min. She appears diaphoretic, and her cardiac exam is notable for an irregularly irregular rhythm with a 2/6 early systolic murmur. Blood counts and metabolic panel are within normal limits. The patient's lithium level is within therapeutic range. Which of the following laboratory tests would be the most useful to include in the evaluation of this patient?

Question: Which of the following laboratory tests would be the most useful to include in the evaluation of this patient?

Answer: Thyroid stimulating hormone and free thyroxine levels


Context: A 42-year-old man with systolic heart failure secondary to amyloidosis undergoes heart transplantation. The donor heart is obtained from a 17-year-old boy who died in a motor vehicle collision. Examination of the donor heart during the procedure shows a flat, yellow-white discoloration with an irregular border on the luminal surface of the aorta. A biopsy of this lesion is most likely to show which of the following?

Question: A biopsy of this lesion is most likely to show which of the following?

Answer: Lipoprotein-laden macrophages


Context: A 14-year-old boy is brought to the emergency department because of a 4-hour history of vomiting, lethargy, and confusion. Three days ago, he was treated with an over-the-counter medication for fever and runny nose. He is oriented only to person. His blood pressure is 100/70 mm Hg. Examination shows bilateral optic disc swelling and hepatomegaly. His blood glucose concentration is 65 mg/dL. Toxicology screening for serum acetaminophen is negative. The over-the-counter medication that was most likely used by this patient has which of the following additional effects?

Question: The over-the-counter medication that was most likely used by this patient has which of the following additional effects?

Answer: Decreased uric acid elimination


Context:
A 53-year-old woman comes to the physician because of pain in her ankle. She twisted her right ankle inward when walking on uneven ground the previous day. She describes the pain as 6 out of 10 in intensity. She is able to bear weight on the ankle and ambulate. Three weeks ago, she had an episode of gastroenteritis that lasted for two days and resolved spontaneously. She has type 2 diabetes mellitus, hypertension, and hyperlipidemia. Her father has type 2 diabetes mellitus and chronic renal failure. Her mother has hypothyroidism and a history of alcohol abuse. The patient drinks 8–10 beers each week and does not smoke or use illicit drugs. She adheres to a strict vegetarian diet. Current medications include metformin, atorvastatin, and lisinopril. Her temperature is 36.9°C (98.4°F), heart rate is 84/min, and blood pressure is 132/80 mm Hg. Examination of the right ankle shows edema along the lateral aspect. She has pain with eversion and tenderness to palpation on the lateral malleolus. The foot is warm to touch and has dry skin. Pedal pulses are palpable. She has decreased sensation to light touch on the plantar and dorsal aspects of the big toe. She has full range of motion with 5/5 strength in flexion and extension of the big toe. Laboratory studies show:
Hemoglobin 15.1 g/dL
Hemoglobin A1c 8.1%
Leukocyte count 7,200/mm3
Mean corpuscular volume 82 μm3
Serum
Na+ 135 mEq/L
K+ 4.0 mEq/L
Cl- 101 mEq/L
Urea nitrogen 24 mg/dL
Creatinine 1.3 mg/dL
Thyroid-stimulating hormone 1.2 μU/mL
Which of the following is the most likely cause of the decreased sensation in this patient?"

Question:
Laboratory studies show:
Hemoglobin 15.1 g/dL
Hemoglobin A1c 8.1%
Leukocyte count 7,200/mm3
Mean corpuscular volume 82 μm3
Serum
Na+ 135 mEq/L
K+ 4.0 mEq/L
Cl- 101 mEq/L
Urea nitrogen 24 mg/dL
Creatinine 1.3 mg/dL
Thyroid-stimulating hormone 1.2 μU/mL
Which of the following is the most likely cause of the decreased sensation in this patient?"

Answer: Microvascular damage


Context: A 62-year-old man with a 5-year history of chronic obstructive pulmonary disease comes to the physician for a follow-up examination. He has had episodic palpitations over the past week. His only medication is a tiotropium-formoterol inhaler. His pulse is 140/min and irregular, respirations are 17/min, and blood pressure is 116/70 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 95%. The lungs are clear to auscultation. Cardiac examination shows no murmurs, rubs, or gallops. Serum concentrations of electrolytes, thyroid-stimulating hormone, and cardiac troponins are within the reference range. An electrocardiogram is shown. 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: Verapamil therapy


Context: A 63-year-old woman comes to the physician with a 3-month history of progressively worsening right calf pain. She reports that the pain occurs after walking for about 10 minutes and resolves when she rests. She has hypertension and hyperlipidemia. She takes lisinopril and simvastatin daily. She has smoked two packs of cigarettes daily for 34 years. Her pulse is 78/min and blood pressure is 142/96 mm Hg. Femoral and popliteal pulses are 2+ bilaterally. Left pedal pulses are 1+; right pedal pulses are absent. Remainder of the examination shows no abnormalities. Ankle-brachial index (ABI) is 0.65 in the right leg and 0.9 in the left leg. This patient is at greatest risk of which of the following conditions?

Question: This patient is at greatest risk of which of the following conditions?

Answer:
Acute myocardial infarction
"


Context: An 11-month-old boy is brought to the physician for the evaluation of recurrent otitis media since birth. The patient’s immunizations are up-to-date. He is at the 5th percentile for height and weight. Physical examination shows multiple petechiae and several eczematous lesions over the scalp and extremities. The remainder of the examination reveals no abnormalities. Laboratory studies show a leukocyte count of 9,600/mm3 (61% neutrophils and 24% lymphocytes), a platelet count of 29,000/mm3, and an increased serum IgE concentration. Which of the following is the most likely diagnosis?

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

Answer: Wiskott-Aldrich syndrome


Context:
A 65-year-old man with chronic myelogenous leukemia comes to the physician because of severe pain and swelling in both knees for the past day. He finished a cycle of chemotherapy 1 week ago. His temperature is 37.4°C (99.4°F). Physical examination shows swelling and erythema of both knees and the base of his left big toe. Laboratory studies show:
Leukocyte count 13,000/mm3
Serum
Creatinine 2.2 mg/dL
Calcium 8.2 mg/dL
Phosphorus 7.2 mg/dL
Arthrocentesis of the involved joints is most likely to show which of the following?"

Question:
Laboratory studies show:
Leukocyte count 13,000/mm3
Serum
Creatinine 2.2 mg/dL
Calcium 8.2 mg/dL
Phosphorus 7.2 mg/dL
Arthrocentesis of the involved joints is most likely to show which of the following?"

Answer: Monosodium urate crystals


Context: In translation, the wobble phenomenon is best illustrated by the fact that:

Question: In translation, the wobble phenomenon is best illustrated by the fact that:

Answer: A tRNA with the UUU anticodon can bind to either AAA or AAG codons


Context: A 34-year-old primigravid woman at 8 weeks' gestation comes to the emergency department 4 hours after the onset of vaginal bleeding and crampy lower abdominal pain. She has passed multiple large and small blood clots. The vaginal bleeding and pain have decreased since their onset. Her temperature is 37°C (98.6°F), pulse is 98/min, and blood pressure is 112/76 mm Hg. Pelvic examination shows mild vaginal bleeding and a closed cervical os. An ultrasound of the pelvis shows minimal fluid in the endometrial cavity and no gestational sac. Which of the following is the most likely diagnosis?

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

Answer: Complete abortion


Context: A 6-year-old boy presents to his pediatrician accompanied by his mother for evaluation of a rash. The rash appeared a little over a week ago, and since that time the boy has felt tired. He is less interested in playing outside, preferring to remain indoors because his knees and stomach hurt. His past medical history is significant for an upper respiratory infection that resolved uneventfully without treatment 2 weeks ago. Temperature is 99.5°F (37.5°C), blood pressure is 115/70 mmHg, pulse is 90/min, and respirations are 18/min. Physical exam shows scattered maroon macules and papules on the lower extremities. The abdomen is diffusely tender to palpation. There is no cervical lymphadenopathy or conjunctival injection. Which of the following will most likely be found in this patient?

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

Answer: Leukocytoclastic vasculitis


Context: An investigator is studying a drug that acts on a G protein-coupled receptor in the pituitary gland. Binding of the drug to this receptor leads to increased production of inositol triphosphate (IP3) in the basophilic cells of the anterior pituitary. Administration of this drug every 90 minutes is most likely to be beneficial in the treatment of which of the following conditions?

Question: Administration of this drug every 90 minutes is most likely to be beneficial in the treatment of which of the following conditions?

Answer: Anovulatory infertility


Context:
A 69-year-old male presents to his primary care provider for a general checkup. The patient currently has no complaints. He has a past medical history of diabetes mellitus type II, hypertension, depression, obesity, and a myocardial infarction seven years ago. The patient's prescribed medications are metoprolol, aspirin, lisinopril, hydrochlorothiazide, fluoxetine, metformin, and insulin. The patient states that he has not been filling his prescriptions regularly and that he can not remember what medications he has been taking. His temperature is 99.5°F (37.5°C), pulse is 96/min, blood pressure is 180/120 mmHg, respirations are 18/min, and oxygen saturation is 97% on room air.

Serum:
Na+: 139 mEq/L
K+: 4.3 mEq/L
Cl-: 100 mEq/L
HCO3-: 24 mEq/L
BUN: 7 mg/dL
Glucose: 170 mg/dL
Creatinine: 1.2 mg/dL

On physical exam which of the following cardiac findings would be expected?

Question:
Serum:
Na+: 139 mEq/L
K+: 4.3 mEq/L
Cl-: 100 mEq/L
HCO3-: 24 mEq/L
BUN: 7 mg/dL
Glucose: 170 mg/dL
Creatinine: 1.2 mg/dL

On physical exam which of the following cardiac findings would be expected?

Answer: Heart sound prior to S1


Context: A 17-year-old teenager is brought to the emergency department with severe bleeding from his right hand. He was involved in a gang fight about 30 minutes ago where he received a penetrating stab wound by a sharp knife in the region of the ‘anatomical snuffbox’. A vascular surgeon is called in for consultation. Damage to which artery is most likely responsible for his excessive bleeding?

Question: Damage to which artery is most likely responsible for his excessive bleeding?

Answer: Radial artery


Context:
A 36-year-old woman comes to the gynecologist because of a 4-month history of irregular menstrual cycles. Menses occur at irregular 15 to 45-day intervals and last 1–2 days with minimal flow. She also reports a milk-like discharge from her nipples for 3 months, as well as a history of fatigue and muscle and joint pain. She does not have abdominal pain, fever, or headache. She has recently gained 2.5 kg (5.5 lb) of weight. She was diagnosed with schizophrenia and started on aripiprazole by a psychiatrist 8 months ago. She has hypothyroidism but has not been taking levothyroxine for 6 months. She does not smoke or consume alcohol. She appears healthy and anxious. Her vital signs are within normal limits. Pelvic examination shows vaginal atrophy. Visual field and skin examination are normal. Laboratory studies show:
Hemoglobin 12.7 g/dL
Serum
Glucose 88 mg/dL
Creatinine 0.7 mg/dL
Thyroid-stimulating hormone 16.3 μU/mL
Cortisol (8AM) 18 μg/dL
Prolactin 88 ng/mL
Urinalysis is normal. An x-ray of the chest and ultrasound of the pelvis show no abnormalities. Which of the following is the most likely explanation for the nipple discharge in this patient?"

Question: Which of the following is the most likely explanation for the nipple discharge in this patient?"

Answer: Hypothyroidism


Context: A 14-year-old girl presents to the emergency room complaining of abdominal pain. She was watching a movie 3 hours prior to presentation when she developed severe non-radiating right lower quadrant pain. The pain has worsened since it started. She also had non-bloody non-bilious emesis 1 hour ago and continues to feel nauseated. Her temperature is 101°F (38.3°C), blood pressure is 130/90 mmHg, pulse is 110/min, and respirations are 22/min. On exam, she has rebound tenderness at McBurney point and a positive Rovsing sign. She is stabilized with intravenous fluids and pain medication and is taken to the operating room to undergo a laparoscopic appendectomy. While in the operating room, the circulating nurse leads the surgical team in a time out to ensure that introductions are made, the patient’s name and date of birth are correct, antibiotics have been given, and the surgical site is marked appropriately. This process is an example of which of the following human factor engineering elements?

Question: This process is an example of which of the following human factor engineering elements?

Answer: Standardization


Context: A 6-year-old boy is brought to the emergency department for acute intermittent umbilical abdominal pain and several episodes of nonbilious vomiting for 4 hours. The pain radiates to his right lower abdomen and occurs every 15–30 minutes. During these episodes of pain, the boy draws up his knees to the chest. He had two similar episodes within the past 6 months. Abdominal examination shows periumbilical tenderness with no masses palpated. Transverse abdominal ultrasound shows concentric rings of bowel. His hemoglobin concentration is 10.2 g/dL. Which of the following is the most common underlying cause of this patient's condition?

Question: Which of the following is the most common underlying cause of this patient's condition?

Answer: Meckel diverticulum


Context:
A 16-year-old female presents to the physician for delayed onset of menstruation. She reports that all of her friends have experienced their first menses, and she wonders whether “something is wrong with me.” The patient is a sophomore in high school and doing well in school. Her past medical history is significant for an episode of streptococcal pharyngitis six months ago, for which she was treated with oral amoxicillin. The patient is in the 35th percentile for weight and 5th percentile for height. On physical exam, her temperature is 98.7°F (37.1°C), blood pressure is 112/67 mmHg, pulse is 71/min, and respirations are 12/min. The patient has a short neck and wide torso. She has Tanner stage I beast development and pubic hair with normal external female genitalia. On bimanual exam, the vagina is of normal length and the cervix is palpable.

Which of the following is the most accurate test to diagnose this condition?

Question: Which of the following is the most accurate test to diagnose this condition?

Answer: Karyotype analysis


Context: A 23-year-old male comes to the physician because of a 2-week history of fatigue, muscle aches, and a dry cough. He has also had episodes of painful, bluish discoloration of the tips of his fingers, nose, and earlobes during this period. Three months ago, he joined the military and attended basic training in southern California. He does not smoke or use illicit drugs. His temperature is 37.8°C (100°F). Physical examination shows mildly pale conjunctivae and annular erythematous lesions with a dusky central area on the extensor surfaces of the lower extremities. Which of the following is the most likely causal organism?

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

Answer: Mycoplasma pneumoniae


Context: A 7-year-old boy is brought to the clinic by his parents due to right ear pain. For the past few days, the patient’s parents say he has had a low-grade fever, a runny nose, and has been frequently pulling on his left ear. Past medical history is significant for a similar episode one month ago for which he has prescribed a 10-day course of amoxicillin. He is up-to-date on all vaccinations and is doing well at school. His temperature is 38.5°C (101.3°F), blood pressure is 106/75 mm Hg, pulse is 101/min, and respiratory rate is 20/min. Findings on otoscopic examination are shown in the image. The patient is treated with amoxicillin with clavulanic acid. Which of the following best describes the benefit of adding clavulanic acid to amoxicillin?

Question: Which of the following best describes the benefit of adding clavulanic acid to amoxicillin?

Answer: Inhibitor effect


Context: A 4-year-old male presents to the pediatrician with a one week history of fever, several days of bloody diarrhea, and right-sided abdominal pain. The mother explains that several other children at his son's pre-K have been having similar symptoms. She heard the daycare owner had similar symptoms and may have her appendix removed, but the mother claims this may just have been a rumor. Based on the history, the pediatrician sends for an abdominal ultrasound, which shows a normal vermiform appendix. She then sends a stool sample for culturing. The cultures demonstrate a Gram-negative bacteria that is motile at 25 C but not at 37 C, non-lactose fermenter, and non-hydrogen sulfide producer. What is the most likely causative agent?

Question: What is the most likely causative agent?

Answer: Yersinia enterocolitica


Context: A 45-year-old man comes to the physician for the evaluation of limited mobility of his right hand for 1 year. The patient states he has had difficulty actively extending his right 4th and 5th fingers, and despite stretching exercises, his symptoms have progressed. He has type 2 diabetes mellitus. He has been working as a mason for over 20 years. His father had similar symptoms and was treated surgically. The patient has smoked one pack of cigarettes daily for 25 years and drinks 2–3 beers every day after work. His only medication is metformin. Vital signs are within normal limits. Physical examination shows skin puckering near the proximal flexor crease. There are several painless palmar nodules adjacent to the distal palmar crease. Active and passive extension of the 4th and 5th digits of the right hand is limited. Which of the following is the most likely underlying mechanism of this patient's symptoms?

Question: Which of the following is the most likely underlying mechanism of this patient's symptoms?

Answer: Palmar fibromatosis


Context: A 2-year-old boy is being evaluated for an autosomal-recessive condition that produces valine instead of glutamine in the β-globin gene. On further examination, the patient’s X-ray showed a crew cut appearance of the skull. Which of the following statements about his condition is false?

Question: Which of the following statements about his condition is false?

Answer: An individual needs 2 defective β-globin genes to have the sickle cell trait


Context: A 7-year-old boy is brought to his pediatrician by his parents because of a new rash. The family immigrated from Laos one year ago and recently obtained health insurance. A week ago, the boy stated that he was “not feeling well” and asked to stay home from school. At the time, he starting having cough, nasal congestion, and irritated eyes – symptoms that persisted and intensified. His parents recall that at the time they noticed small whitish-blue papules over the red buccal mucosa opposite his molars. Five days ago, his parents noticed a red rash around his face that quickly spread downward to cover most of his arms, trunk, and then legs. His temperature is 102.5°F (39.2°C), blood pressure is 110/85 mmHg, pulse is 102/min, and respirations 25/min. On physical exam, he has intermittent cough, cervical lymphadenopathy, and nonpurulent conjunctivitis accompanied by a confluent, dark red rash over his body. This patient is at risk for which of the following complications later in life?

Question: This patient is at risk for which of the following complications later in life?

Answer: CNS degeneration


Context: A 41-year-old nulliparous woman, at 15 weeks' gestation comes to the emergency department because of an 8-hour history of light vaginal bleeding. She had a spontaneous abortion at 11 weeks' gestation 9 months ago. Vital signs are within normal limits. Abdominal examination is unremarkable. On pelvic examination, there is old blood in the vaginal vault and at the closed cervical os. There are bilateral adnexal masses. Serum β-hCG concentration is 122,000 mIU/ml. Results from dilation and curettage show hydropic chorionic villi and proliferation of cytotrophoblasts and syncytiotrophoblasts. There are no embryonic parts. Vaginal ultrasound shows that both ovaries are enlarged and have multiple thin-walled, septated cysts with clear content. Which of the following is the most likely cause of the ovarian findings?

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

Answer: Theca lutein cysts


Context: A 39-year-old pregnant woman at 16 weeks gestation recently underwent a quad-screen which revealed elevated beta-hCG, elevated inhibin A, decreased alpha-fetoprotein, and decreased estradiol. An ultrasound was performed which found increased nuchal translucency. Which of the following is recommended for diagnosis?

Question: Which of the following is recommended for diagnosis?

Answer: Confirmatory amniocentesis and chromosomal analysis of the fetal cells


Context: Four months after giving birth, a young woman presents to the hospital complaining of lack of breast milk secretion. The patient complains of constantly feeling tired. Physical exam reveals that she is slightly hypotensive and has lost a significant amount of weight since giving birth. The patient states that she has not experienced menstruation since the birth. Which of the following is likely to have contributed to this patient's presentation?

Question: Which of the following is likely to have contributed to this patient's presentation?

Answer: Obstetric hemorrage


Context: A 64-year-old African American female comes to the physician’s office for a routine check-up. The patient’s past medical history is significant for hypertension, diabetes, and osteoarthritis in her right knee. Her medications include metformin, glimepiride, lisinopril, metoprolol, hydrochlorothiazide, and ibuprofen as needed. Her only complaint is an unremitting cough that started about 3 weeks ago and she has noticed some swelling around her mouth. The drug most likely responsible for her recent symptoms most directly affects which part of the kidney?

Question: The drug most likely responsible for her recent symptoms most directly affects which part of the kidney?

Answer: Efferent arteriole


Context: A 26-year-old primigravida woman presents to her obstetrician for her first prenatal visit. Her last menstrual cycle was 12 weeks ago. She denies tobacco, alcohol, illicit drug use, or history of sexually transmitted infections. She denies recent travel outside the country but is planning on visiting her family in Canada for Thanksgiving in 3 days. Her past medical and family history is unremarkable. Her temperature is 97.5°F (36.3°C), blood pressure is 119/76 mmHg, pulse is 90/min, and respirations are 20/min. BMI is 22 kg/m^2. Fetal pulse is 136/min. The patient's blood type is B-negative. Mumps and rubella titers are non-reactive. Which of the following is the most appropriate recommendation at this visit?

Question: Which of the following is the most appropriate recommendation at this visit?

Answer: Influenza vaccination


Context: A 38-year-old woman, gravida 2, para 1, at 32 weeks' gestation comes to the physician for a prenatal visit. Pregnancy and delivery of her first child were uncomplicated. She has type 1 diabetes mellitus treated with insulin. Her temperature is 37.2°C (99°F), pulse is 92/min, respirations are 16/min, and blood pressure is 110/86 mm Hg. Examination shows minimal bilateral edema below the knees. The uterus is consistent in size with a 29-week gestation. The remainder of the examination shows no abnormalities. Transabdominal ultrasound shows an intrauterine pregnancy in longitudinal lie, normal fetal cardiac activity, an amniotic fluid index of 5 cm and calcifications of the placenta. This patient's child is at greatest risk of developing which of the following conditions?

Question: This patient's child is at greatest risk of developing which of the following conditions?

Answer: Pulmonary hypoplasia


Context:
A researcher is investigating the relationship between interleukin-1 (IL-1) levels and mortality in patients with end-stage renal disease (ESRD) on hemodialysis. In 2017, 10 patients (patients 1–10) with ESRD on hemodialysis were recruited for a pilot study in which IL-1 levels were measured (mean = 88.1 pg/mL). In 2018, 5 additional patients (patients 11–15) were recruited. Results are shown:
Patient IL-1 level (pg/mL) Patient IL-1 level (pg/mL)
Patient 1 (2017) 84 Patient 11 (2018) 91
Patient 2 (2017) 87 Patient 12 (2018) 32
Patient 3 (2017) 95 Patient 13 (2018) 86
Patient 4 (2017) 93 Patient 14 (2018) 90
Patient 5 (2017) 99 Patient 15 (2018) 81
Patient 6 (2017) 77
Patient 7 (2017) 82
Patient 8 (2017) 90
Patient 9 (2017) 85
Patient 10 (2017) 89
Which of the following statements about the results of the study is most accurate?"

Question:
Results are shown:
Patient IL-1 level (pg/mL) Patient IL-1 level (pg/mL)
Patient 1 (2017) 84 Patient 11 (2018) 91
Patient 2 (2017) 87 Patient 12 (2018) 32
Patient 3 (2017) 95 Patient 13 (2018) 86
Patient 4 (2017) 93 Patient 14 (2018) 90
Patient 5 (2017) 99 Patient 15 (2018) 81
Patient 6 (2017) 77
Patient 7 (2017) 82
Patient 8 (2017) 90
Patient 9 (2017) 85
Patient 10 (2017) 89
Which of the following statements about the results of the study is most accurate?"

Answer: The median of IL-1 measurements is now larger than the mean.


Context: A 68-year-old man presents to his primary care physician with pain that started after he visited his daughter as she moved into her new apartment. The patient states that the pain is likely related to all the traveling he has done and helping his daughter move and setup up furniture. The patient has a past medical history of obesity, type II diabetes, multiple concussions while he served in the army, and GERD. He is currently taking metformin, lisinopril, omeprazole, and a multivitamin. On physical exam, pain is elicited upon palpation of the patient's lower back. Flexion of the patient's leg results in pain that travels down the patient's lower extremity. The patient's cardiac, pulmonary, and abdominal exam are within normal limits. Rectal exam reveals normal rectal tone. The patient denies any difficulty caring for himself, defecating, or urinating. Which of the following is the best next step in management?

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

Answer: NSAIDS and activity as tolerated


Context:
A laboratory technician processes basic metabolic panels for two patients. Patient A is 18 years old and patient B is 83 years old. Neither patient takes any medications regularly. Serum laboratory studies show:
Patient A Patient B
Na+ (mEq/L) 145 141
K+ (mEq/L) 3.9 4.4
Cl- (mEq/L) 103 109
HCO3- (mEq/L) 22 21
BUN (mg/dL) 18 12
Cr (mg/dL) 0.8 1.2
Glucose (mg/dL) 105 98
Which of the following most likely accounts for the difference in creatinine seen between these two patients?"

Question:
Serum laboratory studies show:
Patient A Patient B
Na+ (mEq/L) 145 141
K+ (mEq/L) 3.9 4.4
Cl- (mEq/L) 103 109
HCO3- (mEq/L) 22 21
BUN (mg/dL) 18 12
Cr (mg/dL) 0.8 1.2
Glucose (mg/dL) 105 98
Which of the following most likely accounts for the difference in creatinine seen between these two patients?"

Answer: Normal aging


Context: A 55-year-old woman is being managed on the surgical floor after having a total abdominal hysterectomy as a definitive treatment for endometriosis. On day 1 after the operation, the patient complains of fevers. She has no other complaints other than aches and pains from lying in bed as she has not moved since the procedure. She is currently receiving ondansetron, acetaminophen, and morphine. Her temperature is 101°F (38.3°C), blood pressure is 127/68 mmHg, pulse is 100/min, respirations are 17/min, and oxygen saturation is 94% on room air. Her abdominal exam is within normal limits and cardiopulmonary exam is only notable for mild crackles. Which of the following is the most likely etiology of this patient’s fever?

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

Answer: Inflammatory stimulus of surgery