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A 34-year-old man comes to the physician for a 2-month history of an itchy rash on his forearm. He feels well otherwise and has not had any fever or chills. He returned from an archaeological expedition to Guatemala 4 months ago. Skin examination shows a solitary, round, pink-colored plaque with central ulceration on the right wrist. There is right axillary lymphadenopathy. A photomicrograph of a biopsy specimen from the lesion is shown. Which of the following is the most likely causal organism?

Leishmania braziliensis

step1

E

A 59-year-old woman comes to the physician because of a 1-month history of episodic cough and shortness of breath. The cough is nonproductive and worsens when she climbs stairs and during the night. She has not had chest pain or palpitations. Eight weeks ago, she had fever, sore throat, and nasal congestion. She has a 10-year history of hypertension. She has smoked half a pack of cigarettes daily for 16 years. Her only medication is enalapril. Her pulse is 78/min, respirations are 18/min, and blood pressure is 145/95 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 96%. Diffuse end-expiratory wheezes are heard on pulmonary auscultation. An x-ray of the chest shows no abnormalities. Spirometry shows an FEV1:FVC ratio of 65% and an FEV1 of 60%. Which of the following is the most likely diagnosis?

Asthma

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D

A 2850-g (6-lb 5-oz) newborn is delivered at term to a 19-year-old primigravid woman via normal spontaneous vaginal delivery. The mother has had no prenatal care. Examination of the newborn in the delivery room shows a small, retracted jaw and hypoplasia of the zygomatic arch. This patient's condition is most likely caused by abnormal development of the structure that also gives rise to which of the following?

Incus

step1

C

A 52-year-old woman comes to the emergency department because of epigastric abdominal pain that started after her last meal and has become progressively worse over the past 6 hours. She has had intermittent pain similar to this before, but it has never lasted this long. Her temperature is 39°C (102.2°F). Examination shows a soft abdomen with normal bowel sounds. The patient has sudden inspiratory arrest during right upper quadrant palpation. Her alkaline phosphatase, total bilirubin, amylase, and aspartate aminotransferase levels are within the reference ranges. Abdominal imaging is most likely to show which of the following findings?

Gallstone in the cystic duct

step1

B

A 15-year-old boy is brought to the physician by his father because he has been waking up frequently during the night to urinate. Apart from occasional headaches, he has no other complaints. His family recently emigrated from Tanzania and his medical history is unknown. His father was diagnosed with sickle cell disease at the age of 5. Physical examination shows no abnormalities. Laboratory studies show: Hemoglobin 14.5 g/dL Hematocrit 44% MCV 90 fL Reticulocytes 1.5% A hemoglobin electrophoresis shows: HbA 55% HbS 43% HbF 1% This patient is at greatest risk for which of the following conditions?"

Renal papillary necrosis

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C

A 71-year-old woman comes to the physician because of an 8-month history of fatigue. Laboratory studies show a hemoglobin concentration of 13.3 g/dL, a serum creatinine concentration of 0.9 mg/dL, and a serum alkaline phosphatase concentration of 100 U/L. Laboratory evaluation of which of the following parameters would be most helpful in determining the cause of this patient's symptoms?

Gamma-glutamyl transpeptidase

step1

D

A laboratory physician investigates the chromosomes of a fetus with a suspected chromosomal anomaly. She processes a cell culture obtained by amniocentesis. Prior to staining and microscopic examination of the fetal chromosomes, a drug that blocks cell division is added to the cell culture. In order to arrest chromosomes in metaphase, the physician most likely added a drug that is also used for the treatment of which of the following conditions?

Acute gouty arthritis

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B

Following gastric surgery, a 45-year-old woman complains of severe nausea and vomiting on the 2nd postoperative day. On physical examination, her vitals are stable and examination of the abdomen reveals no significant abnormality. The patient is already receiving a maximum dosage of ondansetron. Metoclopramide is given, and she experiences significant relief from nausea and vomiting. Which of the following best explains the mechanism of action of this drug?

Inhibition of dopamine receptors in the area postrema

step1

A

A 32-year-old woman is found unconscious on the office floor just before lunch by her colleagues. She had previously instructed them on the location of an emergency kit in case this ever happened so they are able to successfully inject her with the substance inside. Her past medical history is significant for type 1 diabetes for which she takes long acting insulin as well as periprandial rapid acting insulin injections. She has previously been found unconscious once before when she forgot to eat breakfast. The substance inside the emergency kit most likely has which of the following properties.

Promotes gluconeogenesis in the liver

step1

B

A 6-year-old girl is brought to the physician because of a generalized pruritic rash for 3 days. Her mother has noticed fluid oozing from some of the lesions. She was born at term and has been healthy except for an episode of bronchitis 4 months ago that was treated with azithromycin. There is no family history of serious illness. Her immunization records are unavailable. She attends elementary school but has missed the last 5 days. She appears healthy. Her temperature is 38°C (100.4°F). Examination shows a maculopapular rash with crusted lesions and vesicles over the entire integument, including the scalp. Her hemoglobin concentration is 13.1 g/dL, leukocyte count is 9800/mm3, and platelet count is 319,000/mm3. Which of the following is the most appropriate next best step?

Calamine lotion

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E

A 3-month-old boy is brought to the emergency room by his mother for 2 days of difficulty breathing. He was born at 35 weeks gestation but has otherwise been healthy. She noticed a cough and some trouble breathing in the setting of a runny nose. His temperature is 100°F (37.8°C), blood pressure is 64/34 mmHg, pulse is 140/min, respirations are 39/min, and oxygen saturation is 93% on room air. Pulmonary exam is notable for expiratory wheezing and crackles throughout and intercostal retractions. Oral mucosa is noted to be dry. Which of the following is the most appropriate diagnostic test?

No further testing needed

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B

A 2200-g (4-lbs 13-oz) female newborn is delivered at term to a 37-year-old gravida 2, para 1 woman. The newborn is at the 10th percentile for length, 14th percentile for weight, and 3rd percentile for head circumference. Examination shows “punched-out“ skin lesions on the scalp, cleft lip, and a small chin. There is a convex-shaped deformity of the plantar surface of the feet. Auscultation shows a holosystolic murmur heard best at the left lower sternal border. Some of her intestines protrude through the umbilicus, covered by a thin membranous sac. An MRI of the brain shows a single ventricle and a fusion of the basal ganglia. Which of the following additional findings is most likely to be seen in this patient?

Polydactyly

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A

A 39-year-old woman presents to the emergency department with fever, cough, and shortness of breath. She reports developing flu-like symptoms 7 days ago but progressively worsened to the point where she experiences dyspnea on exertion. Her cough is accompanied by a mild amount of yellow sputum. Past medical history is notable for a previous admission to the hospital for pneumonia 4 months ago and an admission for bacteremia 6 weeks ago. She additionally has a history of IV heroin abuse, but her last use of heroin was 3 years ago. Temperature is 101.2°F (38.4°C), blood pressure is 104/70 mmHg, pulse is 102/min, and respirations are 20/min. Physical examination demonstrates coarse upper airway breath sounds over the right lower lung field. A faint 1/6 non-radiating systolic flow murmur is auscultated at the first right intercostal space. Abdominal examination is significant for moderate splenomegaly. Tenderness of the wrists and fingers is elicited on palpation, and range of motion is restricted. The patient comments that her range of motion and pain usually improve as the day goes on. Which of the following laboratory abnormalities is most likely to be found in this patient?

Neutropenia

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D

A 72-year-old man presents to his primary care physician complaining of pain and bulging in his groin. He is otherwise healthy and has never had surgery. He is referred to a general surgeon, and is scheduled for an elective hernia repair the following week. On closer inspection in the operating room, the surgeon notes a hernia sac that protrudes through the external inguinal ring, bypassing the inguinal canal. Which of the following accurately describes this patient's condition?

Direct inguinal hernia

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E

A 65-year-old man comes to the physician for evaluation of a neck mass and weight loss. He first noticed the growing mass 2 months ago. The mass is not painful. He also has decreased appetite and intermittent abdominal pain. He has lost 10 kg (22 lb) of weight over the past 3 months. Sometimes, he wakes up in the morning drenched in sweat. He takes daily over-the-counter multivitamins. He appears pale. His pulse is 65/min, blood pressure is 110/70 mm Hg, and temperature is 38.1°C (100.6°F). Physical exam shows a painless, golf ball-sized mass in the anterior triangle of the neck. A biopsy shows large cells with a bilobed nucleus that are CD15- and CD30-positive. Laboratory analysis of serum shows a calcium level of 14.5 mg/dL and a parathyroid hormone level of 40 pg/mL. Which of the following is the most likely explanation of this patient's laboratory findings?

Ectopic vitamin D production

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B

A 29-year-old African American woman presents with incidentally noted bilateral hilar lymphadenopathy on a recent chest radiograph for the evaluation of pneumonia 1 month earlier. Upon questioning, she reports a cough, dyspnea, and angina. The report provided by a previous ophthalmologic consultation did not demonstrate any eye abnormalities. Clinical laboratory pathologic analysis reveals an elevated level of angiotensin-converting enzyme. Her physical examination reveals no obvious abnormalities. Her vital signs show a heart rate of 76/min, respiratory rate of 16/min, and blood pressure of 123/73 mm Hg. Of the following options, which is the mechanism of the reaction causing hilar adenopathy in this patient?

Type IV–cell-mediated (delayed) hypersensitivity reaction

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D

Ten days after starting a new medication, a 60-year-old man is brought to the emergency department after a 3-minute episode of myoclonic jerking movements and urinary incontinence. After regaining consciousness, the patient had no recollection of what happened and seemed confused. He has bipolar disorder, which has been controlled with maintenance therapy for the past 15 years. Physical examination shows dry oral mucosa, muscle fasciculations, and bilateral hand tremors. His speech is slow, and he is disoriented. Which of the following drugs most likely precipitated this patient's current condition?

Celecoxib

step1

D

A previously healthy 2-year-old boy is brought to the emergency department because of a 2-day history of fever and pain in the left lower extremity. His mother says that he has refused to walk for the last two days and has had a poor appetite. He returned from a weekend camping trip about a month ago. His maternal cousin died of osteosarcoma at the age of 12. His immunizations are up-to-date. He is at the 80th percentile for height and 70th percentile for weight. He appears ill. His temperature is 39.3°C (102.7°F), pulse is 115/min, respirations are 19/min, and blood pressure is 95/50 mm Hg. Examination of the left hip shows tenderness; range of motion is limited. Minimal attempts to rotate the hip cause severe discomfort. The remainder of the examination shows no abnormalities. Laboratory studies show: Hemoglobin 12 g/dL Leukocyte count 19,800/mm3 Platelet count 254,000/mm3 Erythrocyte sedimentation rate 55 mm/h Serum Glucose 80 mg/dL CRP 15 mg/L X-rays of the pelvis shows a widened acetabular space on the left side. Which of the following is the most appropriate next step in management?"

Synovial fluid drainage plus cefazolin therapy

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B

A 51-year-old male presents to his primary care provider for a normal check-up. He reports that he “hasn’t felt like himself” recently. He describes feeling down for the past 8 months since his mother passed away. He has had trouble sleeping and has unintentionally lost 15 pounds. He feels guilty about his mother’s death but cannot articulate why. His performance at work has declined and he has stopped running, an activity he used to enjoy. He has not thought about hurting himself or others. Of note, he also complains of numbness in his feet and fingers and inability to maintain an erection. His past medical history is notable for diabetes. He is on metformin. His temperature is 98.6°F (37°C), blood pressure is 125/65 mmHg, pulse is 90/min, and respirations are 16/min. On exam, he is alert and oriented with intact memory and normal speech. He appears tired with a somewhat flattened affect. The best medication for this patient inhibits which of the following processes?

Norepinephrine and serotonin reuptake

step1

B

A 35-year-old man arrives at the emergency department within minutes after a head-on motor vehicle accident. He suffered from blunt abdominal trauma, several lacerations to his face as well as lacerations to his upper and lower extremities. The patient is afebrile, blood pressure is 45/25 mmHg and pulse is 160/minute. A CBC is obtained and is most likely to demonstrate which of the following?

Hb 15 g/dL, Hct 45%

step2&3

C

A 28-year-old man comes to the physician because of a 3-month history of pain in his left shoulder. He is physically active and plays baseball twice a week. The pain is reproduced when the shoulder is externally rotated against resistance. Injury of which of the following tendons is most likely in this patient?

Infraspinatus

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C

A 58-year-old woman presents to the physician with a throbbing headache. She says she had it for the last year and it’s usually located in the right temporal area. There is localized tenderness over the scalp. During the last 2 weeks, she experienced 3 episodes of transient loss of vision on the right side, without ocular pain. On physical examination, her vital signs are normal. Palpation reveals that the pulsations of the superficial temporal artery on the right side are reduced in amplitude. Laboratory studies show: Blood hemoglobin 10.7 g/dL (6.64 mmol/L) Leukocyte count 8,000/mm3 (8.0 x 109/L) Platelet count 470,000/mm3 (470 x 109/L) Erythrocyte sedimentation rate 60 mm/h (60 mm/h) Which of the following conditions is most likely to co-exist with the presenting complaint in this woman?

Polymyalgia rheumatica

step1

D

A researcher is studying proteins that contribute to intestinal epithelial permeability. He has isolated intestinal tissue from several mice. After processing the tissue into its individual components, he uses a Western blot analysis to identify a protein that forms part of a multi-protein complex at the apical aspect of epithelial cells. The complex is known to provide a diffusion barrier between the apical and basolateral aspects of epithelial cells. Which of the following proteins is this researcher most likely investigating?

Claudin

step1

E

A 38-year-old woman is evaluated for a difficult-to-control hypertension. Her symptoms include sleep interruption because of frequent waking up for voiding and frequent headaches. She has smoked 10 cigarettes daily for the past 5 years. Family history is insignificant. Her vital signs include a blood pressure of 170/96 mm Hg, pulse of 90/min, and temperature of 36.7°C (98.0°F). Physical examination is unremarkable. Her lab results are shown: Serum sodium 146 mEq/L Serum potassium 4 mEq/L Serum bicarbonate 29 mEq/L Her plasma aldosterone concentration (PAC): plasma renin activity (PRA) ratio measured after following all precautions is found to be elevated. Oral salt loading testing reveals a lack of aldosterone suppression. A computerized tomography (CT) scan of the adrenal glands shows a 2 cm mass on the left side. Which of the following is the best next step for this patient?

Adrenal venous sampling

step2&3

B

A 43-year-old woman comes to the office with a 3-day history of a rash. She's had a rash across her neck, shoulders, and the palms of her hands for the past five days. She's also had large-volume watery diarrhea for the same period of time. Past medical history is notable for acute myeloid leukemia, for which she received a stem cell transplant from a donor about two months prior. Physical exam reveals a faint red maculopapular rash across her neck, shoulders, and hands, as well as an enlarged liver and spleen. Labs are notable for a total bilirubin of 10. Which of the following is the mechanism of this patient's pathology?

Graft T cells against host antigens

step2&3

E

A 27-year-old man who recently emigrated as a refugee from Somalia presents with fever, weight loss, fatigue, and exertional chest pain. He says his symptoms began 3 weeks ago and that his appetite has decreased and he has lost 3 kg (6.6 lb) in the last 3 weeks. He denies any history of cardiac disease. His past medical history is unremarkable. The patient admits that he has always lived in poor hygienic conditions in overcrowded quarters and in close contact with cats. His vital signs include: blood pressure 120/60 mm Hg, pulse 90/min, and temperature 38.0°C (100.4°F). Physical examination reveals generalized pallor. A cardiac examination reveals an early diastolic murmur loudest at the left third intercostal space. Abdominal examination reveals a tender and mildly enlarged spleen. Prominent axillary lymphadenopathy is noted. Laboratory investigations reveal a WBC count of 14,500/μL with 5% bands and 93% polymorphonuclear cells. An echocardiogram reveals a 5-mm vegetation on the aortic valve with moderate regurgitation. Three sets of blood cultures are taken over 24 hours followed by empiric antibiotic therapy with gentamicin and vancomycin. The blood cultures show no growth after 5 days. Following a week of empiric therapy, the patient continues to deteriorate. Which of the following would most likely confirm the diagnosis in this patient?

Bartonella serology

step1

A

Four days after having been admitted to the hospital for a pulmonary contusion and whiplash injury sustained in a motor vehicle collision, a 66-year-old woman complains of severe pain in her right flank and muscle spasms. She also has nausea with two episodes of vomiting and abdominal bloating. Her pain had previously been well controlled with acetaminophen every 6 hours. She underwent umbilical hernia repair surgery two years ago. She takes sertraline for depression. Her temperature is 36.5°C (97.7°F), pulse is 99/min, respirations are 17/min, and blood pressure is 102/72 mm Hg. After administration of 0.5 L of crystalloid fluids, blood pressure improves to 118/79 mm Hg. Multiple ecchymoses are present over the anterior abdominal wall in a pattern that follows the course of a seatbelt. There are ecchymoses of the flanks bilaterally. Bowel sounds are absent. There is tenderness to palpation in all four quadrants with voluntary guarding. Her hemoglobin is 7.9 g/dL, leukocyte count is 8,500/mm3, platelet count is 350,000/mm3, prothrombin time is 11 seconds, and activated partial thromboplastin time is 33 seconds. An x-ray of the abdomen shows obliteration of the right psoas shadow and uniform distribution of gas in the small bowel, colon, and rectum without air-fluid levels. Which of the following is the most likely explanation for this patient's symptoms?

Retroperitoneal hemorrhage

step2&3

D

A 65-year-old man comes to the physician because of a 2-week history of chest pain that begins after walking at a brisk pace for 2 blocks. The pain does not radiate anywhere and is hard to localize. He has had similar episodes in the past 6 months and was prescribed sublingual nitroglycerin, which helps relieve the pain. The patient has hypertension and type 2 diabetes mellitus. He takes lisinopril and metformin daily. He appears well. His temperature is 37°C (98.6°F), pulse is 75/min, and blood pressure is 145/90 mm Hg. Examination shows a regular heart rhythm. S1 and S2 are normal. The lungs are clear to auscultation. There is no peripheral edema. Which of the following is the most likely explanation for the improvement of this patient's chest pain?

Decreased end-diastolic pressure "

step2&3

E

A 34-year-old woman presents with confusion, drowsiness, and headache. The patient’s husband says her symptoms began 2 days ago and have progressively worsened with an acute deterioration of her mental status 2 hours ago. The patient describes the headaches as severe, localized to the frontal and periorbital regions, and worse in the morning. Review of symptoms is significant for a mild, low-grade fever, fatigue, and nausea for the past week. Past medical history is significant for HIV infection for which she is not currently receiving therapy. Her CD4+ T cell count last month was 250/mm3. The blood pressure is 140/85 mm Hg, the pulse rate is 90/min, and the temperature is 37.7°C (100.0°F). On physical examination, the patient is conscious but drowsy. Papilledema is present. No pain is elicited with extension of the leg at the knee joint. The remainder of the physical examination is negative. Laboratory findings, including panculture, are ordered. A noncontrast CT scan of the head is negative and is followed by a lumbar puncture. CSF analysis is significant for: Opening pressure 250 mm H2O (70-180 mm H2O) Glucose 30 mg/dL (40-70 mg/dL) Protein 100 mg/dL (<40 mg/dL) Cell count 20/mm3 (0-5/mm3) Which of the following additional findings would most likely be found in this patient?

CSF India ink stain shows encapsulated yeast cells

step1

C

A 55-year-old male is started on nitrate therapy for treatment of stable angina. He experiences significant and immediate relief of his symptoms within minutes of starting therapy. Approximately 48 hours after initiating this new medication, he notes return of chest pain and pressure with exertion that no longer responds to continued nitrate use. Which of the following 24-hour dosing schedules would most likely explain this patient's response to nitrate treatment?

Transdermal nitroglycerin patch placed at 7AM then removed and replaced with another at 7PM

step1

A

A 68-year-old woman comes to the physician for a follow-up visit for elevated blood pressure. Two weeks ago, her blood pressure was 154/78 mm Hg at a routine visit. Subsequent home blood pressure measurements at days 5, 10, and 14 have been: 156/76 mm Hg, 158/80 mm Hg, and 160/80 mm Hg. She has trouble falling asleep but otherwise feels well. She had a cold that resolved with over-the-counter medication 2 weeks ago. She has a history of primary hypothyroidism and a cyst in the right kidney, which was found incidentally 20 years ago. She takes levothyroxine. She is 178 cm (5 ft 10 in) tall and weighs 67 kg (148 lb); BMI is 21.3 kg/m2. Her pulse is 82/min, and blood pressure is 162/79 mm Hg. Examination shows no abnormalities. Laboratory studies, including thyroid function studies, serum electrolytes, and serum creatinine, are within normal limits. Which of the following is the most likely underlying cause of this patient's blood pressure findings?

Decrease in arterial compliance

step2&3

B

An 9-month-old infant is brought to the physician because of a generalized nonpruritic rash for 2 days. The rash began on her trunk and spread to her extremities. Five days ago, she was taken to the emergency department for fever of 40.5°C (104.9°F) and a 1-minute generalized tonic-clonic seizure. She was born at term and has no history of serious illness. Her immunizations are up-to-date. Current medications include acetaminophen. Her temperature is 37.2°C (99.0°F) and pulse is 120/min. Examination shows a maculopapular rash that blanches on pressure. A photograph of the rash is shown. Posterior auricular lymphadenopathy is present. Which of the following is the most likely diagnosis?

Roseola infantum

step2&3

D

An 11-month-old boy is brought to the physician by his adoptive mother for the evaluation of seizures and musty-smelling urine. His immunizations are up-to-date. His height and weight are both below the 10th percentile. He is pale and has blue eyes. He cannot pull himself up from a seated position to stand and does not crawl. Which of the following genetic principles best explains the variety of phenotypic traits seen in this patient?

Pleiotropy

step1

B

A 24-year-old woman is in the intensive care unit for the management of a severe acute asthma exacerbation. She is currently intubated and sedated, and she is receiving intravenous steroids, continuous nebulized beta-agonists, and anticholinergic therapy via breathing treatments. On hospital day 2, she has a new fever to 38.9°C (102.0°F). Chest X-ray shows a right lower lobe consolidation. Blood cultures are collected, and she is started empirically on intravenous cefepime and daptomycin. On hospital day 4, she continues to be febrile; chest X-ray shows interval worsening of the right lower lobe opacity. Which of the following is the most likely reason for treatment failure in this patient?

Inactivation of the medicine in the target tissue

step2&3

C

A 53-year-old Asian woman comes to the physician because of a 2-month history of severe pain in her right leg while walking. She used to be able to walk a half-mile (800-m) to the grocery store but has been unable to walk 200 meters without stopping because of the pain over the past month. She can continue to walk after a break of around 5 minutes. She has hypertension, atrial fibrillation, and type 2 diabetes mellitus. She has smoked one pack of cigarettes daily for the past 32 years. Current medications include metformin, enalapril, aspirin, and warfarin. Vital signs are within normal limits. Examination shows an irregularly irregular pulse. The right lower extremity is cooler than the left lower extremity. The skin over the right leg appears shiny and dry. Femoral pulses are palpated bilaterally; pedal pulses are diminished on the right side. Which of the following is the most appropriate next step in management?

Ankle-brachial index

step2&3

D

A 27-year-old woman develops progressive difficulty breathing after a long day of chores in a dusty house. These chores included brushing the family dog, vacuuming, dusting, and sweeping. She occasionally gets these episodes once or twice a year and has her medication on hand. Her symptoms are reversed by inhaling a β2-adrenergic receptor agonist. Which of the following chemical mediators is responsible for this patient’s breathing difficulties?

Leukotrienes

step1

B

Nine healthy subjects participate in a study of gastric secretions. Subjects are asked to eat a meal at hour 0, at which time the pH of stomach contents and rate of stomach acid secretions are measured over the next 4 hours. Results of the study are shown. Which of the following mediators is most active at point A in the graph?

Acetylcholine

step1

E

A 43-year-old Caucasian woman is admitted to the hospital with acute onset right upper quadrant (RUQ) pain. The pain started 6 hours ago after the patient had a large meal at a birthday party and has progressively worsened. She recalls having similar pain before but not so intense. No significant past medical history. Current medications are only oral contraceptive. Vitals are blood pressure 140/80 mm Hg, heart rate 79/min, respiratory rate 14/min, and temperature 37.6℃ (99.7℉). The patient’s BMI is 36.3 kg/m2. On exam, the patient appears slightly jaundiced. Her cardiac and respiratory examinations are within normal limits. Abdominal palpation reveals tenderness to palpation in the RUQ with no rebound or guarding, and there is an inspiratory arrest on deep palpation in this region. The remainder of the examination is within normal limits. Laboratory tests are significant for the following: RBC count 4.1 million/mm3 Hb 13.4 mg/dL Leukocyte count 11,200/mm3 ESR 22 mm/hr Platelet count 230,000/mm3 Total bilirubin 2 mg/dL Direct bilirubin 1.1 mg/dL ALT 20 IU/L AST 18 IU/L Amylase 33 IU/L Ultrasound of the abdomen shows the following result (see image): The common bile duct (CBD) (not shown in the image) is not dilated. Which of the following procedures is most appropriate for the treatment of this patient?

Laparoscopic cholecystectomy

step2&3

C

A 38-year-old man comes to the physician because of severe muscle pain and swelling of his eyelids for 3 days. He has also had fever and chills during this period. For the last 2 days, he has had severe pain in his mouth while chewing. He had an episode of diarrhea a month ago for which he did not seek medical care. He has no history of serious illness. His sister has dermatomyositis. He returned from a hunting trip to eastern Europe 45 days ago. His temperature is 38.1°C (100.6°F), pulse is 80/min, and blood pressure is 130/70 mm Hg. Examination shows periorbital edema and severe generalized muscle tenderness. There are splinter hemorrhages on both hands. Laboratory studies show: Hemoglobin 14.2 g/dL Leukocyte count 12,500/mm3 Segmented neutrophils 60% Eosinophils 18% Lymphocytes 20% Monocytes 2% Serum Glucose 117 mg/dL Creatinine 1.1 mg/dL Alkaline phosphatase 72 U/L Creatine kinase 765 U/L Urinalysis is within normal limits. Which of the following is most likely to have prevented this patient's condition?"

Cooking meat to 71°C (160°F)

step2&3

B

A 28-year-old man comes to the physician for a pre-employment examination. He has no history of serious illness and takes no medications. A screening blood test is performed in which peptides are added to the sample to stimulate in vitro production of interferon-gamma, which is then measured using an enzyme-linked immunosorbent assay. This test is most likely to be helpful in diagnosing infection with which of the following pathogens?

Mycobacterium tuberculosis

step1

D

A 23-year-old woman comes to the physician because of a 5-month history of a pruritic rash on the bilateral upper extremities. She has no history of serious illness and takes no medications. A skin biopsy of the rash shows intraepidermal accumulation of edematous fluid and widening of intercellular spaces between keratinocytes. Which of the following is the most likely diagnosis?

Eczematous dermatitis

step1

E

A 52-year-old man with a 20+ year history of smoking comes in today to talk about quitting. His wife has recently been trying to quit, and she wants him to quit with her. He has been resistant in the past, but he is now very willing to talk with you about it. Today, he seems like he really wants to make a change. What stage of change does this behavior correspond to?

Preparation

step2&3

C

A 28-year-old woman is brought into the clinic by her husband with concerns that she might be depressed. She delivered a healthy newborn a week and a half ago without any complications. Since then, she has been having trouble sleeping, eating poorly, and has stopped playing with the baby. The patient says she feels like she is drained all the time and feels guilty for not doing more for the baby. Which of the following is the best course of treatment for this patient?

Reassurance

step1

A

A 51-year-old man presents to the emergency department with complaints of upper abdominal pain for the last several hours. He says that the pain travels to his back and is less severe when he leans forward. He is diagnosed with acute pancreatitis following enzyme analysis and CT scan of the abdomen and is subsequently managed in intensive care unit (ICU) with IV fluids, analgesics, nasogastric decompression, and supportive therapy. He recovers quickly and is discharged within a week. However, after 5 weeks, the patient develops projectile vomiting containing food but no bile. Physical examination shows visible peristalsis from left to right in the upper abdomen. A repeat CT scan is done. Which of the following is the next best step in the management of this patient?

Endoscopic drainage

step1

D

A 13-year-old boy is brought to the physician because of a 5-day history of a rash on his chest and back. His mother initially noticed only a few lesions on his back, but since then the rash has spread to his chest. His family returned from a trip to the Caribbean 2 weeks ago. His mother started using a new laundry detergent 8 days ago. He has type 1 diabetes mellitus controlled with insulin. His mother has Hashimoto thyroiditis and his brother has severe facial acne. His temperature is 37.2°C (99°F), pulse is 81/min, and blood pressure is 115/74 mm Hg. Examination of the skin shows multiple, nontender, round, white macules on the chest and trunk. There is fine scaling when the lesions are scraped with a spatula. There are no excoriation marks. The remainder of the examination shows no abnormalities. Which of the following is the most likely underlying mechanism of this patient's symptoms?

Increased growth of Malassezia globosa

step2&3

C

A 72-year-old woman is brought to the emergency department because of increasing abdominal pain for 6 hours. The pain is dull and diffuse over her abdomen and radiates to her lower back bilaterally. Three weeks ago, she was diagnosed with atrial fibrillation and started on warfarin. Her only other medication is 1 g of acetaminophen daily for osteoarthritis of her knees. Her pulse is 87/min and blood pressure is 112/75 mm Hg. Physical examination shows abdominal tenderness to palpation at both lower quadrants. A CT scan of the abdomen shows a retroperitoneal mass and hazy margins of the surrounding structures. In addition to discontinuation of warfarin, the most appropriate next step in management is administration of which of the following?

Phytonadione and prothrombin complex concentrate

step2&3

D

A 36-year-old man presents to a psychiatrist for management of nicotine dependence. He has been a heavy smoker for the past 20 years. He has unsuccessfully attempted to quit smoking many times. He has seen multiple physicians for nicotine dependence. They prescribed nicotine replacement therapy and varenicline. He has also taken two antidepressants and participated in talk therapy. He asks the psychiatrist whether there are other alternatives. The psychiatrist explains that nicotine replacement therapy, non-nicotine pharmacotherapy, and talk therapy are the best options for the management of nicotine dependence. He tells the patient he can take a second-line medication for non-nicotine pharmacotherapy because the first-line medication failed. Which of the following medications would the psychiatrist most likely use to manage this patient’s nicotine dependence?

Clonidine

step2&3

B

A physician attempts to study cirrhosis in his state. Using a registry of admitted patients over the last 10 years at the local hospital, he isolates all patients who have been diagnosed with cirrhosis. Subsequently, he contacts this group of patients, asking them to complete a survey assessing their prior exposure to alcohol use, intravenous drug abuse, blood transfusions, personal history of cancer, and other medical comorbidities. An identical survey is given to an equal number of patients in the registry who do not carry a prior diagnosis of cirrhosis. Which of the following is the study design utilized by this physician?

Case-control study

step2&3

A

A 17-year-old male presents to your office complaining of polyuria, polydipsia, and unintentional weight loss of 12 pounds over the past 3 months. On physical examination, the patient is tachypneic with labored breathing. Which of the following electrolyte abnormalities would you most likely observe in this patient?

Hyperkalemia

step1

B

A 54-year-old man comes to the physician because of generalized fatigue and numbness of his legs and toes for 5 months. He has hypertension and hypercholesterolemia. He underwent a partial gastrectomy for peptic ulcer disease 15 years ago. Current medications include amlodipine and atorvastatin. He is a painter. His temperature is 37°C (98.6°F), pulse is 101/min, respirations are 17/min, and blood pressure is 122/82 mm Hg. Examination shows conjunctival pallor and glossitis. Sensation to vibration and position is absent over the lower extremities. He has a broad-based gait. The patient sways when he stands with his feet together and closes his eyes. His hemoglobin concentration is 10.1 g/dL, leukocyte count is 4300/mm3, and platelet count is 110,000/mm3. Which of the following laboratory findings is most likely to be seen in this patient?

Elevated methylmalonic acid levels

step2&3

C

A 5-year-old male is brought to his pediatrician after recurrent, prolonged upper respiratory infections over a period of several months. Physical exam reveals petechiae on the patient’s legs and arms. Laboratory studies show hemoglobin: 10 g/L, platelet count: 35,000/mm^3, leukocyte count: 6,600/mm^3. A bone marrow aspiration shows an abundance of lymphoblasts indicative of acute lymphoblastic leukemia (ALL). Positive immunostaining for which of the following would support a diagnosis of precursor B-cell leukemia?

CD19, CD10

step1

C

The objective of one case-control study was to assess whether a history of past trauma represents a risk factor for the development of spondyloarthritis. Cases of spondyloarthritis were compared with a random sample taken from the general population in regards to a history of prior trauma. This kind of history, which in turn increased the likelihood of being subjected to X-ray imaging investigations, led to a higher likelihood of diagnosing spondyloarthritis in these individuals compared with the general population. This resulted in a significantly higher proportion of spondyloarthritis in study participants with prior trauma, with the resulting overestimation of related odds ratio. In which case is the bias in this example more likely to occur?

If the outcome is ascertained through electronic health records

step1

A

A 67-year-old man presents to the emergency department with trouble urinating. The patient states that in general he has had difficulty urinating but recently, it has taken significant effort for him to initiate a urinary stream. He finds himself unable to completely void and states he has suprapubic tenderness as a result. These symptoms started suddenly 3 days ago. The patient has a history of benign prostatic hyperplasia, constipation, and diabetes mellitus. His current medications include finasteride, sodium docusate, and hydrochlorothiazide. He recently started taking phenylephrine for seasonal allergies. The patient’s last bowel movement was 2 days ago. His temperature is 99.0°F (37.2°C), blood pressure is 167/98 mmHg, pulse is 90/min, respirations are 14/min, and oxygen saturation is 100% on room air. Physical exam is notable for suprapubic tenderness, and an ultrasound reveals 750 mL of fluid in the bladder. Which of the following is the most likely etiology of this patient’s symptoms?

Medication-induced symptoms

step2&3

B

A 26-year-old woman, gravida 2, para 1, at 26 weeks’ gestation, comes to the emergency department because of pain and swelling in her right calf. Physical examination shows an increased circumference of the right calf. The leg is warm and tender on palpation. Dorsiflexion of the right foot elicits calf pain. An ultrasound of the right leg shows a noncompressible popliteal vein. Which of the following is the most appropriate pharmacotherapy for this patient's condition?

Heparin

step1

C

A 4-year-old boy is brought to the physician by his mother because of generalized weakness and difficulty walking for the past month. Laboratory studies show a hemoglobin concentration of 6.6 g/dL, mean corpuscular volume of 74 μm3, platelet count of 150,000/mm3, and serum total bilirubin of 2 mg/dl. An MRI of the spine shows low signal intensity in all vertebral bodies and a small epidural mass compressing the spinal canal at the level of L1. A CT scan of the head shows osteopenia with widening of the diploic spaces in the skull. A biopsy of the epidural mass shows erythroid colonies with an abundance of megakaryocytes and myeloid cells. Which of the following is the most likely diagnosis?

Beta-thalassemia "

step1

E

A 32-year-old woman comes to the physician because of weight gain, generalized weakness, and irregular menstrual cycles for the past 16 months. She began having symptoms of insomnia and depression 10 months ago. More recently, she has been having difficulties rising from a chair. She has a 2-year history of hypertension. Current medications include citalopram and hydrochlorothiazide. She is 168 cm (5 ft 6 in) tall and weighs 100 kg (220 lb). BMI is 36 kg/m2. Her pulse is 92/min, respirations are 18/min, and blood pressure is 134/76 mm Hg. She appears tired and has a full, plethoric face and central obesity. Examination of the skin shows violaceous linear striations on her lower abdomen. Two midnight serum cortisol studies show measurements of 288 μg/L and 253 μg/L (N < 90); a 24-hour urinary cortisol measurement was 395 μg (N < 300). Upon follow-up laboratory examination, the patient's serum ACTH levels were also elevated at 136 pg/mL (N = 7–50). Which of the following is the most appropriate next step in evaluation?

High-dose dexamethasone suppression test

step2&3

C

A 43-year-old woman is found in the hospital to have a plasma sodium concentration of 126 mg/dL. She was hospitalized after she expressed suicidal ideations and was started on a medication for major depressive disorder. Her past medical history is significant for diabetes for which she is currently taking metformin. Her blood pressure while in the hospital has been around 130/85 mmHg and she is not taking any other medications. Urinalysis shows a serum osmolality of 1085 mOsm/L. Which of the following best describes the cell bodies of the cells that are behaving abnormally in this patient?

Located in the hypothalamus

step1

D

A 41-year-old nulliparous woman comes to the physician for an annual pelvic examination and Pap smear. Over the past year she has been feeling healthy. She is sexually active and uses an intrauterine device with copper for contraception. She has smoked one pack of cigarettes daily for 20 years. She is 160 cm (5 ft 3 in) tall and weighs 88 kg (194 lb); BMI is 34.4 kg/m2. Bimanual pelvic examination shows an irregularly enlarged uterus. A transvaginal ultrasound reveals a singular 4 cm, hypoechoic mass inside the myometrial wall. Which of the following is the most likely cause of this finding?

Leiomyoma

step2&3

A

A 52-year-old man comes to the physician for a routine health maintenance examination. He feels well. His blood pressure is 125/70 mm Hg. His glomerular filtration rate is calculated to be 105 mL/min/1.73 m2 and glucose clearance is calculated to be 103 mL/min. This patient is most likely being treated with which of the following agents?

Canagliflozin

step1

B

An 18-month-old boy is brought in by his parents for a routine check-up. The parents state that the patient still has not had any language development, and they are concerned about developmental delay. Of note, they have also noticed that the patient’s facial features have changed significantly in the last year. The patient also seems to have trouble visually focusing on objects or on the television. On exam, the patient's temperature is 98.2°F (36.8°C), blood pressure is 108/72 mmHg, pulse is 86/min, and respirations are 14/min. Of interest, the patient has not increased much in length or weight in the past 3 months. He is now in the 25th percentile for weight but is in the 90th percentile for head circumference. The patient does not appear to have any gross or fine motor deficiencies. Of note, he has coarse facial features that were not previously noted, including a long face, prominent forehead, and protruding eyes. The patient has corneal clouding bilaterally. At rest, the patient keeps his mouth hanging open. After extensive workup, the patient is found to have 2 mutated copies of the IDUA gene, with no production of the protein iduronidase. Which of the following is the likely mutation found in this disease?

Nonsense mutation

step1

D

A 29-year-old man is brought to the emergency department 20 minutes after being stabbed in the left thigh. His pulse is 110/min, respirations are 20/min, and blood pressure is 110/70 mm Hg. Examination shows a 2-cm wound overlying a pulsatile mass on the left anterior thigh, 4 cm below the inguinal crease. A thrill is palpated, and a bruit is heard over this area. Peripheral pulses are normal bilaterally. The patient is at greatest risk for which of the following?

High-output cardiac failure

step1

B

A 69-year-old man presents to his primary care physician for pain when he walks. He states that the pain is the worst in his left great toe but is also present in his hips and knees. He says that his symptoms are worse with activity and tend to improve with rest. His symptoms have progressively worsened over the past several years. He has a past medical history of obesity, type II diabetes mellitus, smoking, and hypertension. He drinks roughly ten beers per day. His current medications include metformin, insulin, lisinopril, and hydrochlorothiazide. The patient has a recent travel history to Bangkok where he admits to having unprotected sex. On physical exam, examination of the lower extremity results in pain. There is crepitus of the patient's hip when his thigh is flexed and extended. Which of the following is the most likely diagnosis?

Osteoarthritis

step2&3

A

A 51-year-old woman presents to your office with 2 weeks of fatigue and generalized weakness. She has a past medical history of diabetes, hypertension, and hyperlipidemia. She was recently diagnosed with rheumatoid arthritis and started on disease-modifying therapy. She states she has felt less able to do things she enjoys and feels guilty she can't play sports with her children. Review of systems is notable for the patient occasionally seeing a small amount of bright red blood on the toilet paper. Laboratory studies are ordered as seen below. Hemoglobin: 12 g/dL Hematocrit: 36% Leukocyte count: 7,700/mm^3 with normal differential Platelet count: 207,000/mm^3 MCV: 110 fL Which of the following is the most likely etiology of this patient's fatigue?

Medication side effect

step2&3

D

A 34-year-old man presents with acute-onset fever and weakness followed by shifting neurologic deficits (aphasia, motor deficits), which have lasted for a few days. His relatives add that his quantity of urine has reduced significantly over the last few days. He has never had any similar symptoms. Laboratory findings are significant for the following: Hb 8.6 g/dL WBC 6.5 × 1000/mm3 Platelets 43 × 1000/mm3 Cr 3.1 mg/dL BUN 25 mg/dL Na+ 136 mg/dL K+ 4.2 mg/dL Cl- 101 mg/dL HCO3- 24 mg/dL Glu 101 mg/dL Examination of the peripheral smear shows the presence of schistocytes, helmet cells, and spherocytes. Which of the following is true regarding this patient's condition?

Plasmapheresis is the treatment of choice.

step1

E

A 38-year-old man comes to the physician because of a 1-month history of fever and a cough productive of a moderate amount of yellowish sputum. He has had a 6-kg (13-lb) weight loss during this period. He emigrated from the Middle East around 2 years ago. His father died of lung cancer at the age of 54 years. He has smoked one pack of cigarettes daily for 18 years. He appears malnourished. His temperature is 38.1°C (100.6°F), pulse is 101/min, and blood pressure is 118/72 mm Hg. Crackles are heard on auscultation of the chest. Cardiac examination shows no abnormalities. The abdomen is soft and nontender. Laboratory studies show: Hemoglobin 12.3 g/dL Leukocyte count 13,200/mm3 Platelet count 330,000/mm3 Erythrocyte sedimentation rate 66 mm/h Serum Urea nitrogen 16 mg/dL Glucose 122 mg/dL Creatinine 0.9 mg/dL Urinalysis is within normal limits. An x-ray of the chest is shown. Which of the following is the most appropriate next step in management?"

Collect sputum specimens for acid-fast bacilli smear microscopy, culture, and nucleic acid amplification

step2&3

C

A 5-year-old girl is brought to the physician by her mother for a 6-week history of fatigue, fever, and recurrent epistaxis. She has a history of duodenal atresia and an atrioventricular septal defect. She is at the 5th percentile for height and 30th percentile for weight. Physical examination shows painless cervical lymphadenopathy. Her hands are short and broad and there is a space between the first and second toes bilaterally. The spleen tip is palpated 3 cm below the left costal margin. Bone marrow aspirate shows leukocytosis with 50% lymphoblasts. Which of the following best explains this patient's condition?

Meiotic nondisjunction

step1

A

A 27-year-old woman, gravida 2, para 1, at 37 weeks' gestation is admitted to the hospital in active labor. She has received routine prenatal care, but she has not been tested for group B streptococcal (GBS) colonization. Pregnancy and delivery of her first child were complicated by an infection with GBS that resulted in sepsis in the newborn. Current medications include folic acid and a multivitamin. Vital signs are within normal limits. The abdomen is nontender and contractions are felt every 4 minutes. There is clear amniotic fluid pooling in the vagina. The fetus is in a cephalic presentation. The fetal heart rate is 140/min. Which of the following is the most appropriate next step in management?

Administer intrapartum intravenous penicillin

step2&3

C

A 55-year-old woman presents with diarrhea and a rash. She reports having some painful reddish nodules on her legs that she noticed a week ago. She also has been having loose stools associated with cramping lower abdominal pain for the past month. This is associated with an urgency to defecate, and defecation helps relieve the abdominal pain. The stool is occasionally blood-tinged and has some mucus. She feels fatigued but denies fever, weight loss, exposure to any sick people, or history of travel recently. No significant past medical history. Her family history is significant for osteoporosis in her mother, aunt, and older sister. On physical examination, the patient has generalized pallor. There are multiple erythematous tender nodules over the extensor surface of the legs bilaterally below the level of the knee. Abdominal examination reveals mild tenderness to palpation in the left lower quadrant. A DEXA scan is performed and reveals a T-score of -1.5 at the hips and spine. Laboratory findings are significant for microcytic anemia and an elevated ESR. A colonoscopy is performed and reveals patchy inflammation of the colon with rectal sparing. The lesions are present in patches with intermittent normal colonic mucosa. The patient is started on sulfasalazine and shows a good response. However, 6 months later, she returns with a recurrence of her symptoms. A repeat colonoscopy reveals more extensive involvement of the colon and the small bowel. A second drug is added to her treatment regimen. Which of the following is the most common adverse effect associated with the use of this second drug?

Infection

step1

B

A 7-year-old boy presents to the emergency department with several days of high fever accompanied by runny nose, cough, and red itchy eyes. Upon further history, you learn that the family is undocumented and has not had access to primary health services. Upon physical examination you see a red, slightly bumpy rash extending from the head to the mid-chest level. If you had examined this child a prior to the development of the rash, which of the following signs may you have observed?

Koplik spots

step1

E

A 75-year-old female patient comes to the emergency department with altered mental status. She is brought in by her daughter with whom the patient lives. The patient’s daughter said they were watching TV when her mother became unresponsive. On exam the patient withdraws to pain but does not open her eyes or speak. An emergent head CT is done and shows an intracranial bleed. The patient is moved to the ICU and intubated. Further history is obtained from the daughter. The patient has a past medical history of diabetes and a previous stroke. Her medications are metformin and warfarin. The patient is compliant with all of her medications. The daughter says that the patient changed her diet about 1 month ago in response to a diet she saw on a talk show. Which of the following foods is most likely to cause the pathology seen in this patient?

Grapefruit juice

step1

C

A 25-year-old gravida 1 para 0 woman visits an OB/GYN for her first prenatal visit and to establish care. She is concerned about the costs related to future prenatal visits, medications, procedures, and the delivery. She has no type of health insurance through her work and has previously been denied coverage by public health insurance based on her income. Since then she has been promoted and earns a higher salary. In addressing this patient, which of the following is the most appropriate counseling?

She may be eligible for Medicaid because she is pregnant

step2&3

B

A 19-year-old male with cystic fibrosis is evaluated in the clinic for regular health maintenance. He is compliant with his respiratory therapy, but states that he often "forgets" to take the medications before he eats. A panel of labs is drawn which reveals a moderate vitamin D deficiency. Which of the following electrolyte abnormalities might be seen as a consequence of vitamin D deficiency?

Decreased calcium and decreased phosphate

step2&3

D

A 57-year-old male presents with a primary complaint of erectile dysfunction. After proper evaluation, the patient is started on daily administration of sildenafil. This medication directly causes accumulation of which of the following intracellular mediators?

cGMP

step1

B

A 32-year-old Caucasian female is admitted to the emergency department with a 48-hour history of severe and diffuse abdominal pain, nausea, vomiting, and constipation. Her personal history is unremarkable except for an ectopic pregnancy 5 years ago. Upon admission, she is found to have a blood pressure of 120/60 mm Hg, a pulse of 105/min, a respiratory rate 20/min, and a body temperature of 37°C (98.6°F). She has diffuse abdominal tenderness, hypoactive bowel sounds, and mild distention on examination of her abdomen. Rectal and pelvic examination findings are normal. An abdominal plain film of the patient is given. What is the most likely cause of this patient’s condition?

Adhesions

step2&3

C

A 32-year-old woman presents with three-days of vaginal burning, itching, and pain with intercourse. She is in a monogamous relationship with her husband and has an intrauterine device for contraception. Her past medical history is unremarkable, except for recently being treated with antibiotics for sinusitis. Pelvic exam is remarkable for vulvar excoriations, vaginal wall edema, and thick, white discharge in the vault. Wet mount with KOH staining reveals budding filaments with pseudohyphae and hyphae. Which of the following is the most appropriate treatment?

Fluconazole

step1

A

A 2-week-old female newborn is brought to the physician for the evaluation of red eyes with discharge for 2 days. She was born at 39 weeks' gestation to a 22-year-old woman. Pregnancy and delivery were uncomplicated. The mother received irregular prenatal care during the second half of the pregnancy. The newborn weighed 3700 g (8 lb 2.5 oz) at birth, and no congenital anomalies were noted. She currently weighs 4000 g (8 lb 13 oz). Examination of the newborn shows pink skin. The lungs are clear to auscultation. There is mucopurulent discharge in both eyes and mild eyelid swelling. Polymerase chain reaction assay of conjunctival scraping confirms the diagnosis. Which of the following is the most appropriate next step in management?

Oral erythromycin administration

step2&3

D

A 40-year-old woman was admitted to the surgical service after an uncomplicated appendectomy. She underwent surgery yesterday and had an uneventful postoperative course. However, she now complains that she is unable to completely void. She also complains of pain in the suprapubic area. You examine her and confirm the tenderness and fullness in the suprapubic region. You ask the nurse to perform a bladder scan, which reveals 450cc. What is the next appropriate step in management?

Catheterization

step2&3

E

A 42-year-old woman presents to her family physician with a headache. The patient reports that the symptoms started about 2 hours ago when she woke up and have not improved. She states the pain is moderate, throbbing, tight in character, and is located in the occipital region bilaterally. The patient denies any visual and audio disturbances, nausea, and vomiting. She recalls 2 similar headaches in the past month. She has no other relevant medical history. Current medications are alendronate and a daily multivitamin. The patient works long hours as a corporate attorney. A review of systems is significant for mild photophobia. Her temperature is 37.0°C (98.6°F), the blood pressure is 110/70 mm Hg, the pulse is 70/min, the respiratory rate is 18/min, and the oxygen saturation is 98% on room air. On physical exam, the patient is alert and oriented. There is moderate tenderness to palpation diffusely over the upper posterior cervical muscles and occipital region of the scalp. The remainder of the physical exam is normal. Laboratory tests are normal. Urine pregnancy test is negative. What is the next best step in management?

Recommend lifestyle changes, relaxation techniques, and massage therapy

step2&3

E

A 27-year-old man comes to the physician for a follow-up examination. Paroxetine therapy was initiated 6 weeks ago for a major depressive episode. He now feels much better and says he is delighted with his newfound energy. He gets around 8 hours of sleep nightly. His appetite has increased. Last year, he had two episodes of depressed mood, insomnia, and low energy during which he had interrupted his job training and stopped going to the gym. Now, he has been able to resume his job at a local bank. He also goes to the gym three times a week to work out and enjoys reading books again. His temperature is 36.5°C (97.7°F), pulse is 70/min, and blood pressure is 128/66 mm Hg. Physical and neurologic examinations show no abnormalities. On mental status examination, he describes his mood as ""good.” Which of the following is the most appropriate next step in management?"

Continue paroxetine therapy for 2 years

step2&3

A

A 15-year-old girl comes to the physician because of a 2-year history of irregular menstrual bleeding. Menses have occurred at irregular 45- to 60-day intervals since menarche at the age of 13 years. Her last menstrual period was 5 weeks ago and lasted for 7 days with heavy flow and no cramping. She is not sexually active. She is 171 cm (5 ft 7 in) tall and weighs 58 kg (128 lb); BMI is 20 kg/m2. Her temperature is 36.6°C (97.8°F), pulse is 80/min, and blood pressure is 110/60 mm Hg. Pelvic examination shows a normal-appearing vagina and cervix. Bimanual examination shows a normal-sized uterus and no palpable adnexal masses. The remainder of the physical examination shows no abnormalities. A urine pregnancy test is negative. Which of the following is the most likely explanation for this patient's symptoms?

Anovulation

step2&3

D

A 7-year-old boy is brought by his parents to his pediatrician due to progressive fatigue and shortness of breath while playing sports. He is otherwise healthy with no known medical disorders and no other symptoms. 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. On physical examination, his temperature is 36.9ºC (98.4ºF), pulse rate is 90/min, blood pressure is 100/70 mm Hg, and respiratory rate is 18/min. Pulses in all four extremities are equal and normally palpated; there is no radio-femoral delay. The pediatrician suspects a congenital heart disease after auscultation of the heart. Which of the following congenital heart diseases is most likely to present with the clinical features listed above?

Atrial septal defect

step2&3

D

A previously healthy 17-year-old boy is brought to the emergency department by his mother for further evaluation after elective removal of his wisdom teeth. During the procedure, the patient had persistent bleeding from the teeth's surrounding gums. Multiple gauze packs were applied with minimal effect. The patient has a history of easy bruising. The mother says her brother had similar problems when his wisdom teeth were removed, and that he also has a history of easy bruising and joint swelling. The patient takes no medications. His temperature is 37°C (98.6°F), pulse is 90/min, and blood pressure is 108/74 mm Hg. Laboratory studies show: Hematocrit 35% Leukocyte count 8,500/mm3 Platelet count 160,000/mm3 Prothrombin time 15 sec Partial thromboplastin time 60 sec Bleeding time 6 min Fibrin split products negative Serum Urea nitrogen 20 mg/dL Creatinine 1.0 mg/dL Bilirubin Total 1.0 mg/dL Direct 0.5 mg/dL Lactate dehydrogenase 90 U/L Peripheral blood smear shows normal-sized platelets. Which of the following is the most likely diagnosis?"

Hemophilia

step2&3

D

A 48-year-old man with a history of diabetes mellitus presents to his primary care physician with lethargy, joint pain, and impotence. Lab evaluation is notable for a ferritin of 1400 ug/L (nl <300 ug/L), increased total iron, increased transferrin saturation, and decreased total iron binding capacity. All of the following are true regarding this patient's condition EXCEPT:

It may improve with calcium chelators

step2&3

C

A 68-year-old man is brought to the clinic by his daughter who has noticed behavioral changes and frequent headaches for the past 2 weeks. The patient’s daughter says he has been having memory and simple calculation issues, gets upset easily, and his grip strength has dramatically declined. The patient was completely normal prior to these recent changes and used to be able to perform his activities of daily living without a problem. He has a past medical history significant for hypertension, stable angina, and benign prostatic hypertrophy, as well as frequent falls with the last one occurring 1 month ago. Physical examination is remarkable for dyscalculia, short-term memory deficits, and decreased grip strength (4/5) in his right hand. A noncontrast CT of the head is performed and is shown in the image. Which of the following is the most likely etiology of this patient condition?

Tearing of bridging veins

step1

B

A 30-year-old woman, gravida 1, para 0, at 40 weeks' gestation is admitted to the hospital in active labor. Pregnancy was complicated by iron deficiency anemia treated with iron supplements. At the beginning of the first stage of labor, there are coordinated, regular, rhythmic contractions of high intensity that occur approximately every 10 minutes. Four hours later, the cervix is 100% effaced and 10 cm dilated; the vertex is at -1 station. Over the next two hours, there is minimal change in in fetal descent; vertex is still at -1 station. Fetal birth weight is estimated at the 75th percentile. The fetal heart rate is 145/min and is reactive with no decelerations. Contractions occurs approximately every 2 minutes with adequate pressure. Epidural anesthesia was not given, as the patient is coping well with pain. Which of the following is the most appropriate next step in management?

Observation for another hour

step2&3

D

A 23-year-old woman, gravida 2, para 1, at 26 weeks gestation comes to the physician for a routine prenatal visit. Physical examination shows a uterus consistent in size with a 26-week gestation. Fetal ultrasonography shows a male fetus with a thick band constricting the right lower arm; the limb distal to the constrictive band cannot be visualized. The most likely condition is an example of which of the following embryological abnormalities?

Disruption

step1

C

A 47-year-old man presents to the emergency department due to a rash. He states the rash started last night and is very concerning to him. The patient cannot remember being exposed to any environmental stimuli such as new detergents or poison ivy. The patient recently started following with a primary care provider who is helping him manage his arthritis and a new onset cough. His temperature is 99.5°F (37.5°C), blood pressure is 127/68 mmHg, pulse is 125/min, respirations are 18/min, and oxygen saturation is 98% on room air. Physical exam is notable for the findings of coalescing erythematous macules, bullae, desquamation, and mucositis only on the upper half of his back. Cardiopulmonary exam and abdominal exam are within normal limits. Inspection of the patient’s oropharynx reveals ulcers and erythema. Which of the following is the most likely diagnosis?

Steven-Johnson syndrome

step2&3

D

A 12-year-old boy presents to the pediatrician with complaints of chronic cough for the past two years. The cough is present during the day, especially after returning from school. His school teacher says he does not cough at school. The cough is absent while he is asleep, although it increases during examinations or when he experiences boredom. His mother reports that there was a one-month period where he did not cough, but during that month, he used to shrug his shoulders frequently, especially when he was stressed or fatigued. There is no history of sneezing, nasal discharge, nasal congestion, headache, ear symptoms, or breathing difficulty. Detailed history does not suggest the presence of a mood disorder, obsessive-compulsive symptoms, or attention-deficit/hyperactivity disorder. There is no past history of a known neurological disorder, and there is no history of substance abuse. On physical examination, his vital signs are stable. Examination of his respiratory and cardiovascular systems is normal. However, the pediatrician notes repeated eye blinking; upon asking about eye blinking, the mother reports that he has had this habit since he was almost eight years old. Further inquiry suggests that eye blinking, coughing, and grunting disappear for a few weeks without explanation, only to reappear again. Which of the following drugs is likely to be most effective to control this patient’s symptoms?

Haloperidol

step2&3

D

A 27-year-old woman consults an obstetrician as she is planning to become pregnant. She has been diagnosed with HIV (human immunodeficiency virus) infection recently and is currently taking antiretroviral therapy (HAART), as prescribed by her physician. The obstetrician emphasizes the importance of antenatal and peripartum antiretroviral therapy for reducing the risk of mother-to-child transmission of HIV. She also tells the patient that certain antiretroviral drugs, if taken during pregnancy, increase the risk of birth defects in the fetus. She gives a printed list of such drugs to the woman for educational and informational purposes. Which of the following drugs are most likely to be present on the list?

Efavirenz and Delavirdine

step1

B

A 1-month-old baby is brought to the emergency department because he had a coughing spell while feeding and turned blue. The mother says that the blue color went away when she picked the baby up and brought his knees to his chest. The physician orders a chest X-ray which shows a boot-shaped heart and he tells the mother that the baby has a condition that is caused by an anterosuperior displacement of the infundibular septum. What are the 4 features of the baby’s cardiac condition?

Pulmonary stenosis, right ventricular hypertrophy, ventricular septal defect, overriding aorta

step1

E

A 16-year-old girl is brought to the physician by her mother because she has not had her menstrual period yet. At birth, she was found to have partial labial fusion and clitoromegaly. The mother reports that during the pregnancy she had noticed abnormal hair growth on her chin. The girl has severe acne. Three years ago, she broke her wrist after a minor trauma. Last year, she sustained a spinal compression fracture after lifting a box during a move. She currently takes oral isotretinoin and an oral contraceptive. The patient is at the 97th percentile for height and 50th percentile for weight. Physical examination shows numerous inflamed pustules on her face and upper back. Breast development is at Tanner stage I. The patient refuses to have a pelvic examination. A pelvic ultrasound shows ovaries with multiple cysts and a normal uterus. Which of the following is the most likely diagnosis?

Aromatase deficiency

step2&3

E

A 6-month-old infant is brought to the physician’s office by his parents due to a fever, cough, and shortness of breath. The cough is dry and has been progressively worsening for the past 48 hours along with the shortness of breath. His fever never exceeded 37.8°C (100.0°F) at home. The parents say that he has also had abundant nasal drainage and loss of appetite. He is irritable and vomited twice during this period. He has no relevant medical or family history. His vitals are the following: Pulse rate 165/min Respiratory rate 77/min Temperature 38.0°C (100.4°F) On physical examination, there is nasal congestion with thick secretions, accompanied by nasal flaring. On chest examination, intercostal retractions are seen and diffuse wheezing on both sides are heard on auscultation. What is the most likely cause?

Bronchiolitis

step1

D

A 67-year-old woman comes to the physician because of fever, chills, myalgias, and joint pain 1 month after undergoing aortic prosthetic valve replacement due to high-grade aortic stenosis. She does not drink alcohol or use illicit drugs. Her temperature is 39.3°C (102.8°F). She appears weak and lethargic. Physical examination shows crackles at both lung bases and a grade 2/6, blowing diastolic murmur over the right sternal border. Laboratory studies show leukocytosis and an elevated erythrocyte sedimentation rate. The causal organism is most likely to have which of the following characteristics?

Novobiocin-sensitive, coagulase-negative cocci

step1

B

A 42-year-old woman presents to her primary care provider with vision loss. She reports that twice over the last 2 weeks she has had sudden “black out” of the vision in her right eye. She notes that both episodes were painless and self-resolved over approximately a minute. The patient’s past medical history is significant for hypertension, diet-controlled diabetes mellitus, and hypothyroidism. Her family history is notable for coronary artery disease in the patient’s father and multiple sclerosis in her mother. Ophthalmologic and neurologic exam is unremarkable. Which of the following is the best next step in management?

Ultrasound of the carotid arteries

step2&3

E

A 37-year-old man presents to his primary care provider with dysphagia. He notes that his symptoms began several weeks ago and have worsened over time. He now has trouble swallowing solids and liquids. He denies any other symptoms. He has no significant past medical history. Travel history reveals a recent trip to South America but no other travel outside the United States. His temperature is 100°F (37.8°C), blood pressure is 120/81 mmHg, pulse is 99/min, respirations are 14/min, and oxygen saturation is 98% on room air. HEENT exam is unremarkable. He has no palpable masses in his abdomen. What is the most appropriate next step in management?

Barium swallow

step2&3

A

A 61-year-old woman presents for a routine health visit. She complains of generalized fatigue and lethargy on most days of the week for the past 4 months. She has no significant past medical history and is not taking any medications. She denies any history of smoking or recreational drug use but states that she drinks “socially” approx. 6 nights a week. She says she also enjoys a “nightcap,” which is 1–2 glasses of wine before bed every night. The patient is afebrile, and her vital signs are within normal limits. On physical examination, there is significant pallor of the mucous membranes. Laboratory findings are significant for a mean corpuscular volume (MCV) of 72 fL, leukocyte count of 4,800/mL, hemoglobin of 11.0 g/dL, and platelet count of 611,000/mL. She is started on oral ferrous sulfate supplements. On follow-up, her laboratory parameters show no interval change in her MCV or platelet level. Which of the following is the best next step in the management of this patient?

Continue oral ferrous sulfate and supplement with ascorbic acid

step2&3

B

A 41-year-old man with HIV comes to the physician because of rectal bleeding and itching for 2 weeks. During this period, he has also had pain with defecation. Four months ago, he was diagnosed with anogenital warts that were treated with cryotherapy. Over the past year, he has been sexually active with 3 male partners. He uses condoms inconsistently. Current medications are zidovudine, emtricitabine, and efavirenz. Digital rectal examination and anoscopy show an exophytic mass on the anal margin that is protruding into the anal canal. The mass is tender to palpation and bleeds easily on contact. Laboratory studies show a leukocyte count of 7,600/mm3 and a CD4+ T-lymphocyte count of 410/mm3 (N ≥ 500). A biopsy specimen of the lesion shows a well-differentiated squamous cell carcinoma. Which of the following cellular processes was most likely involved in the pathogenesis of this patient's malignancy?

Inactivation of TP53 gene "

step1

E

A 3-year-old child is brought to the emergency department by his parents. The child presents with significant rapid breathing and appears unwell. On examination, his liver size is 1.5 times larger than children of his age, and he has mild pitting edema in his legs. This child is also in the lower weight-age and height-age percentiles. On auscultation, mild rales were noted and a fixed split S2 was heard on inspiration. There is no family history of congenital disorders or metabolic syndromes. Which of the following is the likely diagnosis?

Atrial septal defect

step2&3

B

A neurophysiologist describes the mechanism of a specific type of synaptic transmission to his students. While illustrating this, he points out that when the action potential reaches the presynaptic terminal of a chemical synapse, the voltage-gated Ca2+ channels open. Ca2+ ions trigger the release of neurotransmitters from vesicles in the presynaptic terminal. In this type of synaptic transmission, increased cytosolic Ca2+ levels cause the release of a neurotransmitter from small vesicles with dense cores. Which of the following neurotransmitters is most likely to be the one that is released into the synaptic cleft in this type of synapse?

Epinephrine

step1

B

A 32-year-old man with a history of major depressive disorder is brought to the emergency department by his wife because of a sudden onset of restlessness and disorientation that developed 3 hours ago. The patient’s wife says that he suddenly started sweating, having tremors, and mumbling to himself. Yesterday, the patient visited his psychiatrist with worsening depression who added phenelzine to his current treatment regimen. No other significant past medical history. His temperature is 39.7°C (103.5°F), blood pressure is 145/90 mm Hg, and pulse is 115/min. On physical examination, the skin is flushed. Mucous membranes are dry, and pupils are dilated. There is pronounced clonus in the extremities bilaterally. Babinski sign is present bilaterally. All the patient’s medications are discontinued, and intravenous fluids are started. Which of the following drugs most likely interacted with phenelzine to cause this patient’s condition?

Sertraline

step2&3

C