Context: A 66-year-old man is brought into the emergency department by his daughter for a change in behavior. Yesterday the patient seemed more confused than usual and was asking the same questions repetitively. His symptoms have not improved over the past 24 hours, thus the decision to bring him in today. Last year, the patient was almost completely independent but he then suffered a "series of falls," after which his ability to care for himself declined. After this episode he was no longer able to cook for himself or pay his bills but otherwise had been fine up until this episode. The patient has a past medical history of myocardial infarction, hypertension, depression, diabetes mellitus type II, constipation, diverticulitis, and peripheral neuropathy. His current medications include metformin, insulin, lisinopril, hydrochlorothiazide, sodium docusate, atorvastatin, metoprolol, fluoxetine, and gabapentin. On exam you note a confused man who is poorly kept. He has bruises over his legs and his gait seems unstable. He is alert to person and place, and answers some questions inappropriately. The patient's pulse is 90/minute and his blood pressure is 170/100 mmHg. Which of the following is the most likely diagnosis?

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

Answer: Vascular dementia


Context:
A 33-year-old woman presents to her primary care physician for a wellness check-up. She states that recently she has been feeling well other than headaches that occur occasionally, which improve with ibuprofen and rest. She has a past medical history of hypertension and headaches and is currently taking hydrochlorothiazide. Her temperature is 99.2°F (37.3°C), blood pressure is 157/108 mmHg, pulse is 90/min, respirations are 14/min, and oxygen saturation is 98% on room air. Physical exam reveals a young woman who appears healthy. A normal S1 and S2 are auscultated on cardiac exam, and her lungs are clear with good air movement bilaterally. From her previous visit, it was determined that she has an elevated aldosterone and low renin level. Laboratory values are ordered as seen below.

Serum:
Na+: 139 mEq/L
Cl-: 100 mEq/L
K+: 3.7 mEq/L
HCO3-: 29 mEq/L
BUN: 20 mg/dL
Creatinine: 1.1 mg/dL

Which of the following is the most likely diagnosis?

Question:
Serum:
Na+: 139 mEq/L
Cl-: 100 mEq/L
K+: 3.7 mEq/L
HCO3-: 29 mEq/L
BUN: 20 mg/dL
Creatinine: 1.1 mg/dL

Which of the following is the most likely diagnosis?

Answer: Primary hyperaldosteronism


Context: A 42-year-old man is brought to the physician 25 minutes after an episode of violent jerky movements of his hands and legs that lasted for 5 minutes. After the episode, he had difficulty conversing. For the past 10 days, he has had a left-sided headache and nausea. Apart from a history of recurrent ear infections treated with antibiotics, he reports no other personal or family history of serious illness. He works as an assistant at a veterinarian clinic. He appears ill and is oriented to place and person only. His temperature is 37.8°C (100°F), pulse is 102/min, and blood pressure 112/78 mm Hg. Examination shows bilateral optic disc swelling. There is no lymphadenopathy. Muscle strength and tone is normal in all extremities. Deep tendon reflexes are 2+ bilaterally. Plantar reflex shows a flexor response bilaterally. Laboratory studies show a CD4 count within the reference range. An MRI of the brain is shown. Intravenous mannitol and levetiracetam are administered. 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: Aspiration and surgical drainage


Context: A 12-year-old girl is brought to the physician by her mother because of high fever and left ankle and knee joint swelling. She had a sore throat 3 weeks ago. There is no family history of serious illness. Her immunizations are up-to-date. She had an episode of breathlessness and generalized rash when she received dicloxacillin for a skin infection 2 years ago. She appears ill. Her temperature is 38.8°C (102.3°F), pulse is 87/min, and blood pressure is 98/62 mm Hg. Examination shows left ankle and knee joint swelling and tenderness; range of motion is limited. Breath sounds over both lungs are normal. A grade 3/6 holosytolic murmur is heard best at the apex. Abdominal examination is normal. Which of the following is the most appropriate pharmacotherapy?

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

Answer: Clarithromycin


Context: A 58-year-old woman with HIV infection is brought to the emergency department because of a 2-week history of headaches, blurred vision, and confusion. Her current medications include antiretroviral therapy and trimethoprim-sulfamethoxazole. Neurological examination shows ataxia and memory impairment. Her CD4+ T-lymphocyte count is 90/μL. Analysis of her cerebrospinal fluid analysis shows lymphocytic predominant pleocytosis, and PCR is positive for Epstein-Barr virus DNA. An MRI of the brain with contrast shows a solitary, weakly ring-enhancing lesion with well-defined borders involving the corpus callosum. Which of the following is the most likely diagnosis?

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

Answer: Primary cerebral lymphoma


Context: A 19-year-old man presents to a psychiatrist for the management of substance abuse. He reports that he started using the substance 2 years ago and that he smokes it after sprinkling it on his cigarette. He describes that after smoking the substance, he feels excited and as if he does not belong to himself. He also reports that when he is in his room, he sees vivid colors on the walls after using the substance; if he listens to his favorite music, he clearly sees colors and shapes in front of his eyes. There is no history of alcohol or nicotine abuse. The psychiatrist goes through his medical records and notes that he had presented with acute substance intoxication 1 month prior. At that point, his clinical features included delusions, amnesia, generalized erythema of his skin, tachycardia, hypertension, dilated pupils, dysarthria, and ataxia. Which of the following signs is also most likely to have been present on physical examination while the man was intoxicated with the substance?

Question: Which of the following signs is also most likely to have been present on physical examination while the man was intoxicated with the substance?

Answer: Nystagmus


Context: An experimental infusable drug, X729, is currently being studied to determine its pharmacokinetics. The drug was found to have a half life of 1.5 hours and is eliminated by first order kinetics. What is the minimum number of hours required to reach a steady state concentration of >90%?

Question: What is the minimum number of hours required to reach a steady state concentration of >90%?

Answer: 6


Context: A 67-year-old man comes to the physician for a follow-up examination. He feels well. His last visit to a physician was 3 years ago. He has chronic obstructive pulmonary disease, coronary artery disease, and hypertension. Current medications include albuterol, atenolol, lisinopril, and aspirin. He has smoked one pack of cigarettes daily for 18 years but stopped 20 years ago. He had a right lower extremity venous clot 15 years ago that required 3 months of anticoagulation therapy. A colonoscopy performed 3 years ago demonstrated 2 small, flat polyps that were resected. He is 175 cm (5 ft 9 in) tall and weighs 100 kg (220 lb); BMI is 32.5 kg/m2. His pulse is 85/min, respirations are 14/min, and blood pressure is 150/80 mm Hg. Examination shows normal heart sounds and no carotid or femoral bruits. Scattered minimal expiratory wheezing and rhonchi are heard throughout both lung fields. Which of the following health maintenance recommendations is most appropriate at this time?

Question: Which of the following health maintenance recommendations is most appropriate at this time?

Answer: Abdominal ultrasonography


Context: A 72-year-old retired shipyard worker received a chest x-ray as part of a routine medical work-up. The radiologist reported incidental findings suggestive of an occupational lung disease. Which of the following descriptions is most consistent with this patient's film?

Question: Which of the following descriptions is most consistent with this patient's film?

Answer: Fibrocalcific parietal pleural plaques on the diaphragm


Context: A 32-year-old man presents to the clinic with a dull low back pain radiating to the buttocks. He first noted it about 2 years ago and it has; progressed since then. He notes that it is worse in the morning and improves later in the day after physical activity. The patient also reports morning stiffness lasting up to 30 minutes and blurred vision, which started about 7 months ago. The patient’s vital signs include: blood pressure 130/80 mm Hg, heart rate 88/min, respiratory rate 16/min, and temperature 36.8°C (98.2°F). Physical examination reveals tenderness over the sacroiliac joints and limitation of the lumbar spine movements in the sagittal plane. The patient’s X-ray is shown in the picture below. Which of the following HLA variants is associated with this patient’s condition?

Question: Which of the following HLA variants is associated with this patient’s condition?

Answer: HLA-B27


Context: A 60-year-old man who was admitted for a fractured hip and is awaiting surgery presents with acute onset altered mental status. The patient is noted by the nurses to be shouting and screaming profanities and has already pulled out his IV and urine catheter. He says he believes he is being kept against his will and does not recall falling or fracturing his hip. The patient must be restrained by the staff to prevent him from getting out of bed. He is refusing a physical exam. Initial examination reveals an agitated elderly man with a trickle of blood flowing down his left arm. He is screaming and swinging his fists at the staff. The patient is oriented x 1. Which of the following is the next, best step in the management of this patient?

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

Answer: Administer an Antipsychotic


Context: A 34-year-old woman comes to the physician for evaluation of a breast lump she noticed 2 days ago while showering. She has no history of major illness. Her mother died of ovarian cancer at age 38, and her sister was diagnosed with breast cancer at age 33. Examination shows a 1.5-cm, nontender, mobile mass in the upper outer quadrant of the left breast. Mammography shows pleomorphic calcifications. Biopsy of the mass shows invasive ductal carcinoma. The underlying cause of this patient's condition is most likely a mutation of a gene involved in which of the following cellular events?

Question: The underlying cause of this patient's condition is most likely a mutation of a gene involved in which of the following cellular events?

Answer: Repair of double-stranded DNA breaks


Context: A 9-month-old boy is brought to the physician because of abnormal crawling and inability to sit without support. A 2nd-trimester urinary tract infection that required antibiotic use and a spontaneous preterm birth via vaginal delivery at 36 weeks’ gestation both complicated the mother’s pregnancy. Physical examination shows a scissoring posture of the legs when the child is suspended by the axillae. Examination of the lower extremities shows brisk tendon reflexes, ankle clonus, and upward plantar reflexes bilaterally. When encouraged by his mother, the infant crawls forward by using normal reciprocal movements of his arms, while his legs drag behind. A brain MRI shows scarring and atrophy in the white matter around the ventricles with ventricular enlargement. Which of the following is most likely associated with the findings in this child?

Question: Which of the following is most likely associated with the findings in this child?

Answer: Antenatal injury


Context: A 69-year-old man is brought to the emergency room by his wife 30 minutes after losing consciousness while they were working in their garden together. The patient says that time seemed to slow down, his vision went dark, and he had a sensation of falling. After 3–5 seconds, he awoke slightly disoriented but quickly regained his baseline mental status. The patient says he has had a few similar episodes that occurred 1–2 months ago for which he did not seek any medical treatment. He says overall he has been more tired than usual and feeling out of breath on his morning walks. He denies any chest pain or palpitations. Past medical history is significant for type 1 diabetes mellitus. Current medications are atorvastatin and insulin. His family history is significant for his father who died of myocardial infarction in his 70’s. His blood pressure is 110/85 mm Hg and pulse is 82/min. On physical examination, there is a 3/6 systolic murmur best heard over the right sternal border with radiation to the carotids. S1 is normal but there is a soft unsplit S2. The lungs are clear to auscultation bilaterally. The remainder of the exam is unremarkable. Which of the following physical exam findings would also most likely be present in this patient?

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

Answer: A slow-rising and delayed upstroke of the carotid pulse


Context: A 69-year-old man comes to the physician because of a 1-week history of blood in the urine and fatigue. He also has had a 5.0-kg (11-lb) weight loss during the past month. Physical examination shows pallor and cachexia. A nontender right flank mass is palpated. A CT scan of the chest, abdomen, and pelvis shows a 5-cm right upper pole renal mass and several pulmonary lesions. A biopsy specimen of an affected area of the lung is obtained. A photomicrograph of the biopsy specimen is shown. Molecular evaluation of the specimen is most likely to show which of the following genetic changes?

Question: Molecular evaluation of the specimen is most likely to show which of the following genetic changes?

Answer: VHL gene deletion


Context:
A 72-year-old man is brought to the emergency department by his daughter because he was found to have decreased alertness that has gotten progressively worse. Three weeks ago he was diagnosed with an infection and given an antibiotic, though his daughter does not remember what drug was prescribed. His medical history is also significant for benign prostatic hyperplasia and hypertension, for which he was prescribed tamsulosin, a thiazide, and an ACE inhibitor. He has not sustained any trauma recently, and no wounds are apparent. On presentation, he is found to be confused. Labs are obtained with the following results:

Serum:
Na+: 135 mEq/L
BUN: 52 mg/dL
Creatinine: 2.1 mg/dL

Urine:
Osmolality: 548 mOsm/kg
Na+: 13 mEq/L
Creatinine: 32 mg/dL

Which of the following etiologies would be most likely given this patient's presentation?

Question:
Labs are obtained with the following results:

Serum:
Na+: 135 mEq/L
BUN: 52 mg/dL
Creatinine: 2.1 mg/dL

Urine:
Osmolality: 548 mOsm/kg
Na+: 13 mEq/L
Creatinine: 32 mg/dL

Which of the following etiologies would be most likely given this patient's presentation?

Answer: Overdiuresis by thiazides


Context: Steroid hormone synthesis, lipid synthesis, and chemical detoxification are activities of which of the following?

Question: Steroid hormone synthesis, lipid synthesis, and chemical detoxification are activities of which of the following?

Answer: Smooth Endoplasmic Reticulum


Context: A 60-year-old woman presents to the emergency department due to progressive shortness of breath and a dry cough for the past week. She notes that her symptoms are exacerbated by physical activity and relieved by rest. The woman was diagnosed with chronic kidney disease 2 years ago and was recently started on regular dialysis treatment. Her pulse rate is 105/min, blood pressure is 110/70 mm Hg, respiratory rate is 30/min, and temperature is 37.8°C (100.0°F). On examination of the respiratory system, there is dullness on percussion, decreased vocal tactile fremitus, and decreased breath sounds over the right lung base. The rest of the physical exam is within normal limits. 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: Pleural effusion


Context:
A 22-year-old female is brought to the emergency department by her roommate with a one day history of fever and malaise. She did not feel well after class the previous night and has been in her room since then. She has not been eating or drinking due to severe nausea. Her roommate checked on her one hour ago and was alarmed to find a fever of 102°F (38.9°C). On physical exam temperature is 103°F (40°C), blood pressure is 110/66 mmHg, pulse is 110/min, respirations are 23/min, and pulse oximetry is 98% on room air. She refuses to move her neck and has a rash on her trunk. You perform a lumbar puncture and the CSF analysis is shown below.

Appearance: Cloudy
Opening pressure: 180 mm H2O
WBC count: 150 cells/µL (93% PMN)
Glucose level: < 40 mg/dL
Protein level: 50 mg/dL
Gram stain: gram-negative diplococci

Based on this patient's clinical presentation, which of the following should most likely be administered?

Question:
Appearance: Cloudy
Opening pressure: 180 mm H2O
WBC count: 150 cells/µL (93% PMN)
Glucose level: < 40 mg/dL
Protein level: 50 mg/dL
Gram stain: gram-negative diplococci

Based on this patient's clinical presentation, which of the following should most likely be administered?

Answer: Ceftriaxone


Context: A 65-year-old man is brought to the emergency department because of a fall that occurred while he was taking a shower earlier that morning. His wife heard him fall and entered the bathroom to find all four of his extremities twitching. The episode lasted approximately 30 seconds. He was unsure of what had happened and was unable to answer simple questions on awakening. He has regained orientation since that time. He has hypertension and hyperlipidemia. Current medications include metoprolol and atorvastatin. His temperature is 37.1°C (98.8°F), pulse is 72/min, respirations are 19/min, and blood pressures is 130/80 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 98%. Cranial nerve examination shows no abnormalities. He has 5/5 strength in all extremities. Examination shows full muscle strength. Sensation to pinprick, light touch, and vibration is normal and symmetrical. A noncontrast head CT is performed and shows a slightly hyperdense mass. Follow-up MRI shows a homogeneous, well-circumscribed 4-cm mass with compression of the adjacent white matter, and a hyperintense rim around the mass on T2 weighted imaging. Which of the following is the most likely diagnosis?

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

Answer: Meningioma


Context: A 48-year-old woman comes to the physician because of a 6-month history of excessive fatigue and a 1-month history of progressively increasing generalized pruritus. She has hypothyroidism, for which she receives thyroid replacement therapy. Physical examination shows jaundice. The liver is palpated 4 cm below the right costal margin. Serum studies show a direct bilirubin concentration of 2.9 mg/dL, alkaline phosphatase activity of 580 U/L, and increased titers of antimitochondrial antibodies and anti-thyroid peroxidase antibodies. Which of the following is the most likely cause of this patient's condition?

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

Answer: Destruction of intrahepatic bile ducts


Context: A 53-year-old woman presents to her primary care physician with joint pain. She reports a 6-month history of progressive pain in her hands that is worse around her knuckles. The pain is symmetric bilaterally and seems to improve after she starts working in the morning at her job in a local grocery store. She has also lost 10 pounds over the past 6 months despite no changes in her weight or exercise regimen. Her past medical history is notable for seasonal allergies, hypertension, and intermittent constipation. She takes losartan and a laxative as needed. She had adolescent idiopathic scoliosis as a child and underwent a spinal fusion at the age of 14. She does not smoke or drink alcohol. Her temperature is 98.6°F (37°C), blood pressure is 135/75 mmHg, pulse is 92/min, and respirations are 16/min. On examination, she appears well and is appropriately interactive. Strength is 5/5 and sensation to light touch is intact in the bilateral upper and lower extremities. An examination of her hands demonstrates symmetric swelling of the metacarpophalangeal joints bilaterally. This patient’s condition is most strongly characterized by which of the following?

Question: This patient’s condition is most strongly characterized by which of the following?

Answer: HLA-DR4


Context:
A 3100-g (6.9-lb) male newborn is brought to the emergency department by his mother because of fever and irritability. The newborn was delivered at home 15 hours ago. He was born at 39 weeks' gestation. The mother's last prenatal visit was at the beginning of the first trimester. She received all standard immunizations upon immigrating from Mexico two years ago. Seven weeks ago, she experienced an episode of painful, itching genital vesicles, which resolved spontaneously. Four hours before going into labor she noticed a gush of blood-tinged fluid from her vagina. The newborn is ill-appearing and lethargic. His temperature is 39.9°C (103.8°F), pulse is 170/min, respirations are 60/min, and blood pressure is 70/45 mm Hg. His skin is mildly icteric. Expiratory grunting is heard on auscultation. Skin turgor and muscle tone are decreased. Laboratory studies show:
Hemoglobin 15 g/dL
Leukocyte count 33,800/mm3
Platelet count 100,000/mm3
Serum glucose 55 mg/dL
Which of the following is the most likely causal organism?"

Question:
Laboratory studies show:
Hemoglobin 15 g/dL
Leukocyte count 33,800/mm3
Platelet count 100,000/mm3
Serum glucose 55 mg/dL
Which of the following is the most likely causal organism?"

Answer: Streptococcus agalactiae


Context: A 10-year-old boy is brought in by his parents with increasing breathlessness. He was diagnosed with asthma about 2 years ago and has been on treatment since then. He was initially observed to have breathlessness, cough and chest tightness 2 or 3 times a week. He would wake up once or twice a month in the nighttime with breathlessness. At that time, his pediatrician started him on a Ventolin inhaler to be used during these episodes. His symptoms were well controlled until a few months ago when he started to experience increased nighttime awakenings due to breathlessness. He is unable to play outside with his friends as much because he gets winded easily and has to use his inhaler almost daily to help him breathe easier. He is able to walk and perform other routine activities without difficulty, but playing or participating in sports causes significant struggles. Based on his symptoms, his pediatrician adds an inhaled formoterol and budesonide combination to his current regime. During spirometry, which of the following peak expiratory flow rates will most likely be observed in this patient?

Question: During spirometry, which of the following peak expiratory flow rates will most likely be observed in this patient?

Answer: 65%


Context: A 17-year-old girl is brought to the physician by her mother because she has not had her menstrual period yet. At birth, she had ambiguous genitalia. The mother reports that during the pregnancy she had noticed abnormal hair growth on her chin. A year ago, the girl broke her distal radius after a minor trauma. She is at the 95th percentile for height and 50th percentile for weight. Physical examination shows nodulocystic acne on the face, chest, and upper back. Breast development is at Tanner stage I. Pelvic examination reveals normal pubic hair with clitoromegaly. A pelvic ultrasound shows ovaries with multiple cysts and a normal uterus. Which of the following is the most likely diagnosis?

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

Answer: Aromatase deficiency


Context: A 56-year-old woman is referred to a plastic surgeon for breast reconstruction approximately 18 months after undergoing right modified radical mastectomy for breast cancer. Physical exam demonstrates atrophy of the lower lateral pectoralis major muscle. Damage to which of the following nerves during mastectomy is the most likely cause of her atrophy?

Question: Damage to which of the following nerves during mastectomy is the most likely cause of her atrophy?

Answer: Medial pectoral


Context: A 4-year-old boy is brought to the physician in December for episodic shortness of breath and a nonproductive cough for 3 months. These episodes frequently occur before sleeping, and he occasionally wakes up because of difficulty breathing. His mother also reports that he became short of breath while playing with his friends at daycare on several occasions. He is allergic to peanuts. He is at the 55th percentile for height and weight. Vital signs are within normal limits. Examination shows mild scattered wheezing in the thorax. An x-ray of the chest shows no abnormalities. Which of the following is the most likely diagnosis?

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

Answer: Asthma


Context: An investigator is studying membranous transport proteins in striated muscle fibers of an experimental animal. An electrode is inserted into the gluteus maximus muscle and a low voltage current is applied. In response to this, calcium is released from the sarcoplasmic reticulum of the muscle fibers and binds to troponin C, which results in a conformational change of tropomyosin and unblocking of the myosin-binding site. The membranous transport mechanism underlying the release of calcium into the cytosol most resembles which of the following processes?

Question: The membranous transport mechanism underlying the release of calcium into the cytosol most resembles which of the following processes?

Answer: Uptake of fructose by small intestinal enterocytes


Context: A 5-year-old boy is brought to the emergency room lapsing in and out of consciousness. The mother reports that 30 minutes ago, the young boy was found exiting the garage severely confused. A container of freshly spilled antifreeze was found on the garage floor. The next appropriate step would be to administer:

Question: The next appropriate step would be to administer:

Answer: Fomepizole


Context: A 39-year-old man comes to the emergency department because of a 2-day history of fever, chills, dyspnea, and a non-bloody productive cough. He was diagnosed with HIV infection 4 years ago and has been on highly active antiretroviral therapy since then. His temperature is 38.8°C (101.8°F). Examination shows crackles over the left lower lung base. His CD4+ T-lymphocyte count is 520/mm3 (N ≥ 500). An x-ray of the chest shows an infiltrate in the left lower lobe. Sputum cultures grow colonies with a narrow zone of green hemolysis without clearing on blood agar. The most likely causal pathogen of this patient's condition produces which of the following virulence factors?

Question: The most likely causal pathogen of this patient's condition produces which of the following virulence factors?

Answer: Polysaccharide capsule


Context: A 38-year-old woman, gravida 3, para 2, at 12 weeks' gestation comes to her obstetrician for a prenatal visit. Screening tests in the first trimester showed a decreased level of pregnancy-associated plasma protein and an increased level of β-hCG. A genetic disorder is suspected. Which of the following results from an additional diagnostic test is most likely to confirm the diagnosis?

Question: Which of the following results from an additional diagnostic test is most likely to confirm the diagnosis?

Answer: Additional chromosome in placental tissue


Context: A 82-year-old woman is brought to the emergency department from a retirement community after she was found down during the evening. On presentation, she complains that she experienced several hours of nausea, vomiting, crampy abdominal pain, and diarrhea prior to blacking out. She said that she cannot recall any factors that may have triggered her symptoms; however, she recalls that some of her friends with whom she eats also had similar symptoms earlier in the day and were brought to the hospital. They often go for walks and occasionally cook for themselves from a garden that they keep in the woods behind the facility. One of the residents on the team recalls seeing other patients from this facility earlier today, one of whom presented with kidney failure and scleral icterus prior to passing away. The enzyme most likely affected in this case has which of the following functions?

Question: The enzyme most likely affected in this case has which of the following functions?

Answer: Synthesis of small nucleolar RNA


Context: A 6-month-old boy presents with decreased growth, pigmented retinopathy, hemolytic anemia, and peripheral neuropathy. You suspect that these signs are the result of a vitamin deficiency leading to increased fatty acid oxidation. Which of the following is most likely responsible for this patient's symptoms?

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

Answer: Abetalipoproteinemia


Context:
A 2-year-old boy is brought to the emergency department after his mother noticed maroon-colored stools in his diaper. He has not had any diarrhea or vomiting. The prenatal and birth histories are unremarkable, and he has had no recent trauma. He tolerates solid foods well. The vital signs include: temperature 37.0℃ (98.6℉), blood pressure 90/60 mm Hg, pulse 102/min, and respiratory rate 16/min. The weight is at the 50th percentile. The examination revealed an alert boy with pallor. The abdomen was mildly tender at the right iliac region without masses. There were no anal fissures or hemorrhoids. A stool guaiac test was positive. The laboratory results are as follows:
Complete blood count (CBC)
Leukocytes 7,500/uL
Hemoglobin 9 g/dL
Hematocrit 24%
Platelets 200,000/uL
Which of the following is the most appropriate next step in the management of this patient?

Question:
The laboratory results are as follows:
Complete blood count (CBC)
Leukocytes 7,500/uL
Hemoglobin 9 g/dL
Hematocrit 24%
Platelets 200,000/uL
Which of the following is the most appropriate next step in the management of this patient?

Answer: Technetium-99m pertechnetate scan


Context: A 14-year-old boy presents to his pediatrician with weakness and frequent episodes of dizziness. He had chronic mucocutaneous candidiasis when he was 4 years old and was diagnosed with autoimmune hypoparathyroidism at age 8. On physical examination, his blood pressure is 118/70 mm Hg in the supine position and 96/64 mm Hg in the upright position. Hyperpigmentation is present over many areas of his body, most prominently over the extensor surfaces, elbows, and knuckles. His laboratory evaluation suggests the presence of antibodies to 21-hydroxylase and a mutation in the AIRE (autoimmune regulator) gene. The pediatrician explains to his parents that his condition is due to the failure of immunological tolerance. Which of the following mechanisms is most likely to have failed in the child?

Question: Which of the following mechanisms is most likely to have failed in the child?

Answer: Negative selection


Context:
A 71-year old man is brought to the emergency department because of progressively worsening shortness of breath and fatigue for 3 days. During the last month, he has also noticed dark colored urine. He had an upper respiratory infection 6 weeks ago. He underwent a cholecystectomy at the age of 30 years. He has hypertension, hyperlipidemia, and type 2 diabetes mellitus. He immigrated to the US from Italy 50 years ago. Current medications include simvastatin, lisinopril, and metformin. He appears pale. His temperature is 37.1°C (98.8°F), pulse is 96/min, respirations are 21/min, and blood pressure is 150/80 mm Hg. Auscultation of the heart shows a grade 4/6 systolic murmur over the right second intercostal space that radiates to the carotids. Laboratory studies show:
Leukocyte count 9,000/mm3
Hemoglobin 8.3 g/dL
Hematocrit 24%
Platelet count 180,000/mm3
LDH 212 U/L
Haptoglobin 15 mg/dL (N=41–165)
Serum
Na+ 138 mEq/L
K+ 4.5 mEq/L
CL- 102 mEq/L
HCO3- 24 mEq/L
Urea nitrogen 20 mg/dL
Creatinine 1.2 mg/dL
Total bilirubin 1.8 mg/dL
Stool testing for occult blood is negative. Direct Coombs test is negative. Echocardiography shows an aortic jet velocity of 4.2 m/s and a mean pressure gradient of 46 mm Hg. Which of the following is the most appropriate next step in management to treat this patient's anemia?"

Question: Which of the following is the most appropriate next step in management to treat this patient's anemia?"

Answer: Aortic valve replacement


Context: A 62-year-old man with gastroesophageal reflux disease and osteoarthritis is brought to the emergency department because of a 1-hour history of severe, stabbing epigastric pain. For the last 6 months, he has had progressively worsening right knee pain, for which he takes ibuprofen several times a day. He has smoked half a pack of cigarettes daily for 25 years. The lungs are clear to auscultation. An ECG shows sinus tachycardia without ST-segment elevations or depressions. This patient is most likely to have referred pain in which of the following locations?

Question: This patient is most likely to have referred pain in which of the following locations?

Answer: Left shoulder


Context: A 57-year-old woman comes to the physician because of a 2-week history of swelling of both her feet. It improves a little bit with elevation but is still bothersome to her because her shoes no longer fit. She has type 2 diabetes mellitus treated with metformin and linagliptin. She was diagnosed with hypertension 6 months ago and started treatment with amlodipine. Subsequent blood pressure measurements on separate occasions have been around 130/90 mm Hg. She otherwise feels well. Today, her pulse is 80/min, respirations are 12/min, and blood pressure is 132/88 mm Hg. Cardiovascular examination shows no abnormalities. There is pitting edema of both ankles. Which of the following would have been most likely to reduce the risk of edema in this patient?

Question: Which of the following would have been most likely to reduce the risk of edema in this patient?

Answer: Addition of enalapril


Context: A 50-year-old woman comes to the physician for the evaluation of excessive hair growth on her chin over the past 2 weeks. She also reports progressive enlargement of her gums. Three months ago, she underwent a liver transplantation due to Wilson disease. Following the procedure, the patient was started on transplant rejection prophylaxis. She has a history of poorly-controlled type 2 diabetes mellitus. Temperature is 37°C (98.6°F), pulse is 80/min, respirations are 22/min, and blood pressure is 150/80 mm Hg. Physical examination shows dark-pigmented, coarse hair on the chin, upper lip, and chest. The gingiva and the labial mucosa are swollen. There is a well-healed scar on her right lower abdomen. Which of the following drugs is the most likely cause of this patient's findings?

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

Answer: Cyclosporine


Context: A 24-year-old man presents to the clinic with the complaint of a new rash. The lesions are not bothersome, but he is worried as he has never seen anything like this on his body. Upon further questioning the patient states has been generally healthy except for a one time "horrible" flu-like episode two months ago in June. He has since gotten better. On physical exam the following rash is observed (Figure 1). What is the cause of this patient's rash?

Question: What is the cause of this patient's rash?

Answer: Molluscum contagiosum virus


Context: An HIV-positive 48-year-old man comes to the emergency department because of a 3-month history of recurrent, painful mouth ulcers. This time, the pain is so severe that the patient cannot eat. He has a history of a seizure disorder but currently does not take any medications. He appears very ill. His temperature is 39.0°C (102.2°F). Physical examination shows numerous vesicular ulcerations on the lips and sloughing of the gums, buccal mucosa, and hard palate. Genetic analysis of the pathogen isolated from the lesions shows a mutation in a gene encoding viral phosphotransferases. Which of the following drugs is the most appropriate treatment?

Question: Which of the following drugs is the most appropriate treatment?

Answer: Cidofovir


Context: A 28-year-old woman presents to an outpatient clinic for a routine gynecologic examination. She is concerned about some swelling on the right side of her vagina. She senses that the right side is larger than the left and complains that sometimes that area itches and there is a dull ache. She denies any recent travel or history of trauma. She mentions that she is sexually active in a monogamous relationship with her husband; they use condoms inconsistently. On physical examination her vital signs are normal. Examination of the pelvic area reveals a soft, non-tender, mobile mass that measures approximately 2 cm in the greatest dimension at the 8 o’clock position on the right side of the vulva, just below the vaginal wall. Which of the following is the most likely diagnosis?

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

Answer: Bartholin duct cyst


Context: A 64-year-old woman presents to the physician’s office to find out the results of her recent abdominal CT. She had been complaining of fatigue, weight loss, and jaundice for 6 months prior to seeing the physician. The patient has a significant medical history of hypothyroidism, generalized anxiety disorder, and hyperlipidemia. She takes levothyroxine, sertraline, and atorvastatin. The vital signs are stable today. On physical examination, her skin shows slight jaundice, but no scleral icterus is present. The palpation of the abdomen reveals no tenderness, guarding, or masses. The CT results shows a 3 x 3 cm mass located at the head of the pancreas. Which of the following choices is most appropriate for delivering bad news to the patient?

Question: Which of the following choices is most appropriate for delivering bad news to the patient?

Answer: Set aside an appropriate amount of time in your schedule, and ensure you will not have any interruptions as you explain the bad news to the patient


Context: An investigator studying DNA replication in Campylobacter jejuni inoculates a strain of this organism into a growth medium that contains radiolabeled thymine. After 2 hours, the rate of incorporation of radiolabeled thymine is measured as a proxy for the rate of DNA replication. The cells are then collected by centrifugation and suspended in a new growth medium that contains no free uracil. After another 2 hours, the rate of incorporation of radiolabeled thymine is measured again. The new growth medium directly affects the function of which of the following enzymes?

Question: The new growth medium directly affects the function of which of the following enzymes?

Answer: Primase


Context: A 22-year-old woman presents to the emergency department feeling lightheaded and states that her heart is racing. She does not have a history of any chronic medical conditions. She is a college sophomore and plays club volleyball. Although she feels stressed about her upcoming final exams next week, she limits her caffeine intake to 3 cups of coffee per day to get a good night sleep. She notes that her brother takes medication for some type of heart condition, but she does not know the name of it. Both her parents are alive and well. She denies recent illness, injuries, or use of cigarettes, alcohol, or recreational drugs. The pertinent negatives from the review of systems include an absence of fever, nausea, vomiting, sweating, fatigue, or change in bowel habits. The vital signs include: temperature 36.8°C (98.2°F), heart rate 125/min, respiratory rate 15/min, blood pressure 90/75 mm Hg, and oxygen saturation of 100% on room air. The laboratory results are within normal limits. The ECG is significant for a shortened PR interval and widened QRS. Which of the following medications should the patient avoid in this scenario?

Question: Which of the following medications should the patient avoid in this scenario?

Answer: Verapamil


Context: A 13-year-old boy is brought to the physician because of a 4-month history of worsening dizziness, nausea, and feeling clumsy. An MRI of the brain shows a well-demarcated, 4-cm cystic mass in the posterior fossa. The patient undergoes complete surgical resection of the mass. Pathologic examination of the surgical specimen shows parallel bundles of cells with eosinophilic, corkscrew-like processes. Which of the following is the most likely diagnosis?

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

Answer: Pilocytic astrocytoma


Context: A 45-year-old man comes to the physician for a 2-day history of headache and breathlessness on exertion. During the same period, he has vomited twice and not passed urine. He also reports pain and stiffness in his fingers that has worsened progressively over the past 2 years. He has no history of serious illness and takes no medications. He does not smoke or drink alcohol. He is in moderate distress. His temperature is 37.2°C (98.9°F), pulse is 88/min, blood pressure is 170/100 mm Hg, and respirations are 24/min. Pulse oximetry on room air shows an oxygen saturation of 91%. Examination reveals pallor, 2+ pretibial edema, and jugular venous distention. The skin on the arms, chest, and upper back is coarse and thickened. Diffuse cutaneous hyperpigmentation and hypopigmented patches with perifollicular hypopigmentation are noted. Contractures are present in the proximal interphalangeal joints of both hands. Diffuse crackles are heard on auscultation of the chest. There is dullness to percussion and decreased breath sounds over both lung bases. S1 and S2 are normal. An S3 gallop is heard at the apex. The remainder of the examination shows no abnormalities. His hemoglobin concentration is 8.1 g/dL, and his serum creatinine is 5.3 mg/dL. Further evaluation of this patient is most likely to show which of the following?

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

Answer: Decreased serum haptoglobin levels


Context: A 62-year-old woman presents to the emergency department complaining of fever, worsening fatigue, and muscle weakness for the previous 48 hours. The patient describes her muscle weakness as symmetric and worse in the upper limbs. Her past medical history is significant for long-standing diabetes type 2 complicated by stage 5 chronic kidney disease (CKD) on hemodialysis. She takes lisinopril, verapamil, metformin, and glargine. Today, the patient’s vital signs include: temperature 38.6°C (101.5°F), pulse 80/min, blood pressure 155/89 mm Hg, respirations 24/min, and 95% oxygen saturation on room air. The cardiac and pulmonary exams are unremarkable. The abdomen is soft and non-tender. Her strength is 3/5 in the upper extremities and 4/5 in the lower extremities and her sensation is intact. Deep tendon reflexes are absent in both the upper and lower limbs. A 12-lead electrocardiogram (ECG) is shown in the image below. Blood work is drawn and the patient is admitted and started on continuous cardiac monitoring. Based on the available information, what is the next best step in managing this patient?

Question: Based on the available information, what is the next best step in managing this patient?

Answer: Administer IV calcium gluconate


Context: A 71-year-old man with recently diagnosed small-cell lung cancer sees his physician because of increasing weakness over the past 3 months. He is unable to climb stairs or comb his hair. His weakness is worse after inactivity and improves with exercise. He is a former smoker with a 30-pack-year history. He is currently preparing for initiation of chemotherapy. His vital signs are within normal limits. On examination, ptosis of both eyelids is seen. Dry oral mucosa is notable. Significant weakness is detected in all four proximal extremities. The patellar and biceps reflexes are absent. Auscultation of the lungs reveals generalized wheezing and rhonchi. Which of the following is the most likely underlying mechanism for this patient’s weakness?

Question: Which of the following is the most likely underlying mechanism for this patient’s weakness?

Answer: Autoantibody-impaired acetylcholine release from nerve terminals


Context: A 68-year-old man is brought to the emergency department for increasing colicky lower abdominal pain and distention for 4 days. He has nausea. He has not passed flatus for the past 2 days. His last bowel movement was 4 days ago. He has hypertension, type 2 diabetes mellitus, and left hemiplegia due to a cerebral infarction that occurred 2 years ago. His current medications include aspirin, atorvastatin, hydrochlorothiazide, enalapril, and insulin. His temperature is 37.3°C (99.1°F), pulse is 90/min, and blood pressure is 126/84 mm Hg. Examination shows a distended and tympanitic abdomen. There is mild tenderness to palpation over the lower abdomen. Bowel sounds are decreased. Digital rectal examination shows an empty rectum. Muscle strength is decreased in the left upper and lower extremities. Deep tendon reflexes are 3+ on the left and 2+ on the right. The remainder of the examination shows no abnormalities. Laboratory studies are within normal limits. An x-ray of the abdomen in left lateral decubitus position is shown. The patient is kept nil per os and a nasogastric tube is inserted. Intravenous fluids are administered. 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: Endoscopic detorsion


Context: A 27-year-old woman, gravida 2, para 1, at 38 weeks' gestation comes to the emergency department in active labor. She received all of her prenatal care for this pregnancy. Pregnancy and delivery of her first child were uncomplicated. The patient's blood type is Rh-negative. Four hours after arrival, a healthy 3650-g (8-lb) female newborn is delivered. Delivery of the fetus is followed by placental retention and heavy vaginal bleeding. One hour later, the placenta is manually removed and the bleeding ceases. The mother's temperature is 36.7°C (98.1°F), pulse is 90/min, and blood pressure is 110/60 mm Hg. Examination shows blood on the vulva, the introitus, and on the medial aspect of each thigh. The neonate's blood type is Rh-positive. A single dose of anti-D immune globulin is administered. 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: Perform rosette test


Context: A 5-year-old boy is brought to the emergency department because of a generalized pruritic rash for 14 hours. Five days ago, he had pink eyes that resolved spontaneously. He has acute lymphoblastic leukemia. He has received 3 cycles of chemotherapy with vincristine, asparaginase, dexamethasone, and doxorubicin. His last treatment cycle was 2 weeks ago. The patient's other medications include multivitamin supplements. His temperature is 38°C (100.4°F), pulse 90/min, and blood pressure is 105/65 mm Hg. Examination of the skin shows multiple crops of macules and papules over the face, trunk, and extremities. There are also excoriation marks and crusted lesions. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next step in the treatment of this patient?

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

Answer: Acyclovir administration


Context:
A 17-year-old adolescent male is brought to the emergency department by fire and rescue after being struck by a moving vehicle. The patient reports that he was running through his neighborhood when a car struck him while turning right on a red light. He denies any loss of consciousness. His temperature is 99.0°F (37.2°C), blood pressure is 88/56 mmHg, pulse is 121/min, respirations are 12/min, and SpO2 is 95% on room air. The patient is alert and oriented to person, place and time and is complaining of pain in his abdomen. He has lacerations on his face and extremities. On cardiac exam, he is tachycardic with normal S1 and S2. His lungs are clear to auscultation bilaterally, and his abdomen is soft but diffusely tender to palpation. The patient tenses his abdomen when an abdominal exam is performed. Bowel sounds are present, and he is moving all 4 extremities spontaneously. His skin is cool with delayed capillary refill. After the primary survey, 2 large-bore IVs are placed, and the patient is given a bolus of 2 liters of normal saline.

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

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

Answer: Focused Abdominal Sonography for Trauma (FAST) exam


Context: An investigator is examining tissue samples from various muscle tissue throughout the body. She notices that biopsies collected from a specific site have a high concentration of sarcoplasmic reticulum, mitochondria, and myoglobin; they also stain poorly for ATPase. Additionally, the cell surface membranes of the myocytes in the specimen lack voltage-gated calcium channels. These myocytes are found in the greatest concentration at which of the following sites?

Question: These myocytes are found in the greatest concentration at which of the following sites?

Answer: Semispinalis muscle


Context: A 36-year-old woman comes to the physician for a 2-month history of urinary incontinence and a vaginal mass. She has a history of five full-term normal vaginal deliveries. She gave birth to a healthy newborn 2-months ago. Since then she has felt a sensation of vaginal fullness and a firm mass in the lower vagina. She has loss of urine when she coughs, sneezes, or exercises. Pelvic examination shows an irreducible pink globular mass protruding out of the vagina. A loss of integrity of which of the following ligaments is most likely involved in this patient's condition?

Question: A loss of integrity of which of the following ligaments is most likely involved in this patient's condition?

Answer: Uterosacral ligament


Context: A 23-year-old woman presents to the emergency department with an acute exacerbation of her 3-month history of low back and right leg pain. She says she has had similar symptoms in the past, but this time the pain was so excruciating, it took her breath away. She describes the pain as severe, shock-like, and localized to her lower back and radiating straight down the back of her right thigh and to her calf, stopping at the ankle. Her pain is worse in the morning, and, sometimes, the pain wakes her up at night with severe buttock and posterior thigh pain but walking actually makes the pain subside somewhat. The patient reports no smoking history or alcohol or drug use. She has been working casually as a waitress and does find bending over tables a strain. She is afebrile, and her vital signs are within normal limits. On physical examination, her left straight leg raise test is severely limited and reproduces her buttock pain at 20° of hip flexion. Pain is worsened by the addition of ankle dorsiflexion. The sensation is intact. Her L4 and L5 reflexes are normal, but her S1 reflex is absent on the right side. A CT of the lumbar spine shows an L5–S1 disc protrusion with right S1 nerve root compression. Which of the following muscle-nerve complexes is involved in producing an S1 reflex?

Question: Which of the following muscle-nerve complexes is involved in producing an S1 reflex?

Answer: Gastrocnemius/soleus-tibial nerve


Context: A 36-year-old man comes to the physician because of a 2-week history of productive cough, weight loss, and intermittent fever. He recently returned from a 6-month medical deployment to Indonesia. He appears tired. Physical examination shows nontender, enlarged, palpable cervical lymph nodes. An x-ray of the chest shows right-sided hilar lymphadenopathy. A sputum smear shows acid-fast bacilli. A diagnosis of pulmonary tuberculosis is made from PCR testing of the sputum. The patient requests that the physician does not inform anyone of this diagnosis because he is worried about losing his job. Which of the following is the most appropriate initial action by the physician?

Question: Which of the following is the most appropriate initial action by the physician?

Answer: Inform the local public health department of the diagnosis


Context: A 32-year-old African American woman presents to her family physician complaining of fevers, fatigue, weight loss, joint pains, night sweats and a rash on her face that extends over the bridge of her nose. She has also had multiple sores in her mouth over the past few weeks. She recently had a root canal procedure done without complications. She has no significant past medical history, but has recently had a urinary tract infection. She denies tobacco, alcohol, and illicit drug use. Laboratory evaluation reveals hemolytic anemia. If she were found to have a cardiac lesion, what would be the most likely pathogenetic cause?

Question: If she were found to have a cardiac lesion, what would be the most likely pathogenetic cause?

Answer: Immune complex deposition and subsequent inflammation


Context: A 38-year-old woman comes to the physician for a follow-up examination. Two years ago, she was diagnosed with multiple sclerosis. Three weeks ago, she was admitted and treated for right lower leg weakness with high-dose methylprednisone for 5 days. She has had 4 exacerbations over the past 6 months. Current medications include interferon beta and a multivitamin. Her temperature is 37°C (98.6°F), pulse is 90/min, and blood pressure is 116/74 mm Hg. Examination shows pallor of the right optic disk. Neurologic examination shows no focal findings. She is anxious about the number of exacerbations and repeated hospitalizations. She is counseled about the second-line treatment options available to her. She consents to treatment with natalizumab. However, she has read online about its adverse effects and is concerned. This patient is at increased risk for which of the following complications?

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

Answer: Progressive multifocal leukoencephalopathy


Context: A 2-day-old male newborn is brought to the emergency department by his mother because of irritability and vomiting for two hours. During this period, he has vomited bilious fluid three times. He has not yet passed stool. The mother has breastfed the newborn every two hours. He has wet two diapers during the last two days. He was born at term and was delivered at home. Pregnancy and delivery were uncomplicated. The mother had no prenatal care during pregnancy. The patient currently weighs 3100 g (6 lb 13 oz) and is 50 cm (19.6 in) in length. The newborn appears restless. His temperature is 37.3°C (99.14°F), pulse is 166/min, respirations are 60/min, and blood pressure is 60/45 mm Hg. There is no redness or warmth around the umbilical cord stump. Cardiopulmonary examination shows no abnormalities. Bowel sounds are sparse. The abdomen is distended. Digital rectal examination shows no abnormalities. An x-ray of the abdomen with contrast shows dilated small bowel loops, a microcolon, a mixture of gas and meconium located in the right lower quadrant. A nasogastric tube is placed and fluid resuscitation is begun. 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: Gastrografin enema


Context:
A 40-year-old woman comes to the physician for the evaluation of fatigue, poor appetite, and an unintentional 10-kg (22-lb) weight loss over the past 6 months. The patient also reports several episodes of nausea and two episodes of non-bloody vomiting. There is no personal or family history of serious illness. Menses occur at regular 27-day intervals and last 6 days. Her last menstrual period was 3 weeks ago. She is sexually active with her husband, but states that she has lost desire in sexual intercourse lately. Her temperature is 37°C (98.6°F), pulse is 100/min, and blood pressure is 96/70 mm Hg. Physical examination shows no abnormalities. Laboratory studies show:
Hemoglobin 13.5 g/dL
Leukocyte count 7,000/mm3
Serum
Na+ 128 mEq/L
Cl- 96 mEq/L
K+ 5.8 mEq/L
HCO3- 23 mEq/L
Glucose 70 mg/dL
AM Cortisol 2 μg/dL
Which of the following is the most appropriate next step in management?"

Question:
Laboratory studies show:
Hemoglobin 13.5 g/dL
Leukocyte count 7,000/mm3
Serum
Na+ 128 mEq/L
Cl- 96 mEq/L
K+ 5.8 mEq/L
HCO3- 23 mEq/L
Glucose 70 mg/dL
AM Cortisol 2 μg/dL
Which of the following is the most appropriate next step in management?"

Answer:
Cosyntropin administration
"


Context: A 22-year-old Caucasian male is stabbed in his left flank, injuring his left kidney. As the surgeon undertakes operative repair, she reviews relevant renal anatomy. All of the following are correct regarding the left kidney EXCEPT?

Question: All of the following are correct regarding the left kidney EXCEPT?

Answer: The left kidney has a longer renal artery than the right kidney


Context: An 82-year-old male with a history of congestive heart failure presented with new-onset atrial fibrillation. He was initially started on carvedilol, but he now requires an additional agent for rate control. He is started on a medicine and is warned by his physician of the following potential side effects associated with this therapy: nausea, vomiting, confusion, blurry yellow vision, electrolyte abnormalities, and potentially fatal arrhythmia. Which of the following is most likely to increase this patient's susceptibility to the toxic effects associated with this medication?

Question: Which of the following is most likely to increase this patient's susceptibility to the toxic effects associated with this medication?

Answer: Hypokalemia


Context: A 25-year-old woman with a psychiatric history of bipolar disorder is brought into the emergency department by emergency medical services. The patient is unconscious, but the mother states that she walked into the patient's room with the patient lying on the floor and an empty bottle of unknown pills next to her. The patient has previously tried to commit suicide 2 years ago. Upon presentation, the patient's vitals are HR 110, BP 105/60, T 99.5, RR 22. The patient soon has 5 episodes non-bilious non-bloody vomiting. Upon physical exam, she has pain in the right upper quadrant and her liver function tests are AST 1050 U/L, ALT 2050 U/L, ALP 55 U/L, Total Bilirubin 0.8 mg/dL, Direct Bilirubin 0.2 mg/dL. You are awaiting her toxicology screen. What is the most likely diagnosis?

Question: What is the most likely diagnosis?

Answer: Acetaminophen ingestion


Context: A 25-year-old woman presents into the clinic complaining of worsening malaise, hair loss, and a rash on her face. The patient states that she has been avoiding daylight because the rash becomes painful, and she has not been able to go to classes because of debilitating arthralgia in her fingers and ankles. No significant past medical history. She takes no medication. At the time of the consult, the patient has a fever of 39.0°C (102.2 °F). The presence of which of the following is most commonly seen on diagnostic labs in this patient’s most likely condition?

Question: The presence of which of the following is most commonly seen on diagnostic labs in this patient’s most likely condition?

Answer: Antinuclear antibody


Context: A 45-year-old woman presents to your office with a serum glucose of 250 mg/dL and you diagnose diabetes mellitus type II. You intend to prescribe the patient metformin, but you decide to order laboratory tests before proceeding. Which of the following basic metabolic panel values would serve as a contraindication to the use of metformin?

Question: Which of the following basic metabolic panel values would serve as a contraindication to the use of metformin?

Answer: Creatinine > 2.0


Context: You are reading through a recent article that reports significant decreases in all-cause mortality for patients with malignant melanoma following treatment with a novel biological infusion. Which of the following choices refers to the probability that a study will find a statistically significant difference when one truly does exist?

Question: Which of the following choices refers to the probability that a study will find a statistically significant difference when one truly does exist?

Answer: Power


Context: A 17-year-old girl comes to the physician because of a 2-day history of pain in her right knee. Last week she had right wrist pain. She has no history of recent trauma. She returned from summer camp in Connecticut 2 weeks ago. She is sexually active with one male partner and uses an oral contraceptive. Her temperature is 38°C (100.4°F). Examination shows several painless vesiculopustular lesions on the back and one lesion on the right sole of the foot. There is swelling of the right knee with tenderness to palpation. Passive extension of the right wrist and fingers elicits pain. Which of the following is the most likely diagnosis?

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

Answer: Disseminated gonococcal infection


Context: A 25-year-old man comes to the physician because of an 8-hour history of painful leg cramping, runny nose, chills, diarrhea, and abdominal pain. Examination shows cool, damp skin with piloerection. The pupils are 7 mm in diameter and equal in size. Deep tendon reflexes are 3+ bilaterally. The diagnosis of opioid withdrawal is made. After the patient is stabilized, the physician initiates a withdrawal regimen with methadone. Which of the following characteristics makes this drug a suitable substance for the treatment of this patient's addiction?

Question: Which of the following characteristics makes this drug a suitable substance for the treatment of this patient's addiction?

Answer: Long elimination half-life


Context: A 55-year-old man presents with intense pain in his left knee that started after returning from a camping trip 2 days ago, during which he consumed copious amounts of alcohol and red meat. He says he has had similar episodes in the past that resolved spontaneously usually over a period of about 10 days. His past medical history is significant for essential hypertension managed with hydrochlorothiazide 20 mg/day. The patient is afebrile, and his vital signs are within normal limits. Physical examination shows edema, warmth, and erythema of the left knee, which is also severely tender to palpation; The range of motion at the left knee joint is limited. A joint arthrocentesis of the left knee is performed, and synovial fluid analysis reveals 20,000 neutrophils and the following image is seen under polarized light microscopy (see image). Which of the following is the best course of treatment for this patient’s condition?

Question: Which of the following is the best course of treatment for this patient’s condition?

Answer: Nonsteroidal antiinflammatory drugs


Context: A 9-month-old male infant is brought to his pediatrician by his mother with lethargy and decreased oral intake for one day. His mother also mentions that he did not sleep well the previous night. A review of the medical record reveals several missed appointments and that the boy was born at 36 weeks gestation via spontaneous vaginal delivery. At the clinic, his temperature is 37.2ºC (99.0ºF), pulse rate is 140/minute, respirations are 44/minute, and blood pressure is 92/60 mm Hg. On physical exam the infant is awake but irritable and the rest of the physical is within normal limits for his age. On ophthalmologic examination, there are multiple retinal hemorrhages that extend to the periphery in both eyes. Which of the following investigations is most likely to be helpful in the management of the infant?

Question: Which of the following investigations is most likely to be helpful in the management of the infant?

Answer: Noncontrast computed tomography of head


Context: A 21-year-old girl with a history of bipolar disorder, now in a depressive episode, presents to the emergency in distress. She reports that she wanted to "end it all" and swallowed a full bottle of acetaminophen. However, regretting what it would do to her parents, and she decided that she wants to live. She appears in no acute distress and clearly states she swallowed the pills one hour ago. What is the most appropriate next step in management?

Question: What is the most appropriate next step in management?

Answer: Give activated charcoal and draw a serum acetaminophen level in three hours


Context: A 7-year-old boy presents to an urgent care clinic from his friend’s birthday party after experiencing trouble breathing. His father explains that the patient had eaten peanut butter at the party, and soon after, he developed facial flushing and began scratching his face and neck. This has never happened before but his father says that they have avoided peanuts and peanut butter in the past because they were worried about their son having an allergic reaction. The patient has no significant medical history and takes no medications. His blood pressure is 94/62 mm Hg, heart rate is 125/min, and respiratory rate is 22/min. On physical examination, his lips are edematous and he has severe audible stridor. Of the following, which type of hypersensitivity reaction is this patient experiencing?

Question: Of the following, which type of hypersensitivity reaction is this patient experiencing?

Answer: Type I hypersensitivity reaction


Context: You conduct a medical research study to determine the screening efficacy of a novel serum marker for colon cancer. The study is divided into 2 subsets. In the first, there are 500 patients with colon cancer, of which 450 are found positive for the novel serum marker. In the second arm, there are 500 patients who do not have colon cancer, and only 10 are found positive for the novel serum marker. What is the overall sensitivity of this novel test?

Question: What is the overall sensitivity of this novel test?

Answer: 450 / (450 + 50)


Context: A 43-year-old man comes to the physician because of weight loss and swelling on the left side of his neck. Physical examination shows a firm, enlarged left upper cervical lymph node that is immobile. Immunohistochemical testing performed on a biopsy specimen from the lymph node stains positive for cytokeratin. Which of the following is the most likely site of the primary neoplasm in this patient?

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

Answer: Skin


Context: A 32-year-old woman presents to the clinic with the complaint of excessive fatigue for the past few weeks. After returning home from the office, she feels too tired to climb up the stairs, comb her hair, or chew her food. She has occasionally experienced double vision. She denies any history of fever, cough, weight loss, night sweats, or snoring. Past history is unremarkable. Physical examination reveals: blood pressure 124/86 mm Hg, heart rate 85/min, respiratory rate 14/min, temperature 37.0°C (98.6°F), and body mass index (BMI) 22.6 kg/m2. On examination, the right upper eyelid is slightly drooping when compared to the left side. Her eye movements are normal. Flexion of the neck is mildly weak. Muscle strength is 5/5 in all 4 limbs. When she is asked to alternately flex and extend her shoulder continuously for 5 minutes, the power in the proximal upper limb muscles becomes 4/5. The muscle tone and deep tendon reflexes are normal. What is the most appropriate test to diagnose this condition?

Question: What is the most appropriate test to diagnose this condition?

Answer: Single-fiber electromyography


Context:
A 30-month-old toddler presents with his mother to the pediatrician for a scheduled follow-up. She is concerned that his appetite has been poor since the death of his father, approximately one year ago. She denies any history of vomiting, refusal of food, diarrhea, constipation, recurrent cough and colds, recurrent wheezing, fast breathing, recurrent fever, or recurrent infections. The boy was born at full term by vaginal delivery with an uneventful neonatal period and infancy. His vaccines are up to date. On physical examination, his vital signs are stable. His complete physical examination does not suggest a specific medical disorder or congenital abnormality. His detailed diagnostic evaluation, including complete blood counts, serum protein, liver function tests, and urinalysis are normal. The pediatrician reviews the patient’s growth chart.
At the age of 18 months he was at the 90th percentile for weight and 75th for height. After plotting his current growth parameters on the growth charts, the pediatrician suspects failure to thrive with psychosocial etiology. Based on which of the following findings on the growth charts did the pediatrician suspect the condition?

Question: Based on which of the following findings on the growth charts did the pediatrician suspect the condition?

Answer: Present gender-specific weight for age between 75 and 50 percentile markers


Context:
A 28-year-old woman presents to her primary care physician complaining of intense thirst and frequent urination for the past 2 weeks. She says that she constantly feels the urge to drink water and is also going to the bathroom to urinate frequently throughout the day and multiple times at night. She was most recently hospitalized 1 month prior to presentation following a motor vehicle accident in which she suffered severe impact to her head. The physician obtains laboratory tests, with the results shown below:

Serum:
Na+: 149 mEq/L
Cl-: 103 mEq/L
K+: 3.5 mEq/L
HCO3-: 24 mEq/L
BUN: 20 mg/dL
Glucose: 105 mg/dL
Urine Osm: 250 mOsm/kg

The patient’s condition is most likely caused by inadequate hormone secretion from which of the following locations?

Question:
The physician obtains laboratory tests, with the results shown below:

Serum:
Na+: 149 mEq/L
Cl-: 103 mEq/L
K+: 3.5 mEq/L
HCO3-: 24 mEq/L
BUN: 20 mg/dL
Glucose: 105 mg/dL
Urine Osm: 250 mOsm/kg

The patient’s condition is most likely caused by inadequate hormone secretion from which of the following locations?

Answer: Posterior pituitary


Context: A 28-year-old man presents with one week of redness and discharge in his eyes, pain and swelling in his left second and third toes, and rash on the soles of his feet. He is sexually active with multiple partners and uses condoms occasionally. He denies any recent travel or illness and does not take any medications. Review of systems is otherwise unremarkable. On physical exam, he has bilateral conjunctivitis, dactylitis of the left second and third toes, and crusty yellow-brown vesicles on his plantar feet. Complete blood count and chemistries are within normal limits. Erythrocyte sedimentation rate (ESR) is 40 mm/h. Toe radiographs demonstrate soft tissue swelling but no fractures. Which diagnostic test should be performed next?

Question: Which diagnostic test should be performed next?

Answer: Nucleic acid amplification testing for Chlamydia trachomatis


Context: An 18-year old college freshman presents to his university clinic because he has not been feeling well for the past two weeks. He has had a persistent headache, occasional cough, and chills without rigors. The patient’s vital signs are normal and physical exam is unremarkable. His radiograph shows patchy interstitial lung infiltrates and he is diagnosed with atypical pneumonia. The patient is prescribed azithromycin and takes his medication as instructed. Despite adherence to his drug regimen, he returns to the clinic one week later because his symptoms have not improved. The organism responsible for this infection is likely resistant to azithromycin through which mechanism?

Question: The organism responsible for this infection is likely resistant to azithromycin through which mechanism?

Answer: Methylation of ribosomal binding site


Context:
A group of researchers is studying various inhaled substances to determine their anesthetic properties. In particular, they are trying to identify an anesthetic with fast onset and quick recovery for use in emergencies. They determine the following data:
Inhalational anesthetic  Blood-gas partition coefficient
A 0.15
B 0.92
C 5.42
Which of the following statements is accurate with regard to these inhaled anesthetic substances?

Question:
They determine the following data:
Inhalational anesthetic  Blood-gas partition coefficient
A 0.15
B 0.92
C 5.42
Which of the following statements is accurate with regard to these inhaled anesthetic substances?

Answer: Agent A has the fastest onset of action


Context: A 14-year-old boy presents to the office for a checkup. He is well-nourished and meets all developmental milestones. He denies any complaints, and you offer him counseling on adolescent issues. On examination, he appears to be a normal, healthy teenager. The only significant finding is the bilateral swelling of the tibial tuberosities. When asked about them, the patient denies trauma and states they are sore, especially when he runs or squats. Which of the following is the underlying cause of this finding?

Question: Which of the following is the underlying cause of this finding?

Answer: Osgood-Schlatter disease


Context: A 23-year-old female presents to the emergency department with monocular blindness. She states that early this morning she lost her vision seemingly "out of nowhere." She denies trauma or any precipitating factors. She does state though that over the past year she has had occasional episodes of weakness and even an episode of urinary incontinence, which always resolve on their own. On exam, pain is elicited with eye movement and nystagmus is appreciated. The emergency physician performs a lumbar puncture. What is most likely to be observed in the CSF of this patient?

Question: What is most likely to be observed in the CSF of this patient?

Answer: Oligoclonal bands


Context:
ََA 22-month-old girl is brought to the emergency department with a 24-hour history of fever, irritability, and poor feeding. The patient never experienced such an episode in the past. She met the normal developmental milestones, and her vaccination history is up-to-date. She takes no medications, currently. Her temperature is 38.9°C (102.0°F). An abdominal examination reveals general tenderness without organomegaly. The remainder of the physical examination shows no abnormalities. Laboratory studies show the following results:
Urine
Blood 1+
WBC 10–15/hpf
Bacteria Many
Nitrite Positive
Urine culture from a midstream collection reveals 100,000 CFU/mL of Escherichia coli. Which of the following interventions is the most appropriate next step in evaluation?

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

Answer: Renal and bladder ultrasonography


Context: A 34-year-old woman presents to her primary care physician for a routine check-up. She complains that she is not feeling her normal self, but has no specific complaints. After a routine examination, the physician orders a full thyroid workup, including TSH, T3, and free T4. He also refers her directly to an oncologist for an initial consultation. Which type of lymphadenopathy was most likely present during the physical examination that made the primary care physician react this way?

Question: Which type of lymphadenopathy was most likely present during the physical examination that made the primary care physician react this way?

Answer: Localized painless lymphadenopathy


Context: A 52-year-old man presents to his primary care physician to discuss laboratory results that were obtained during his annual checkup. He has no symptoms or concerns and denies changes in eating or urination patterns. Specifically, the physician ordered a panel of metabolic laboratory tests to look for signs of diabetes, hyperlipidemia, or other chronic disorders. A spot glucose check from a random blood sample showed a glucose level of 211 mg/dL. A hemoglobin A1c level was obtained at the same time that showed a level of 6.3%. A fasting blood glucose was obtained that showed a blood glucose level of 125 mg/dL. Finally, a 2-hour glucose level was obtained after an oral glucose tolerance test that showed a glucose level of 201 mg/dL. Which of the following statements is most accurate for this patient?

Question: Which of the following statements is most accurate for this patient?

Answer: This patient has type 2 diabetes as diagnosed by his oral tolerance blood glucose


Context: A 35-year-old man is brought to the emergency department from a kitchen fire. The patient was cooking when boiling oil splashed on his exposed skin. His temperature is 99.7°F (37.6°C), blood pressure is 127/82 mmHg, pulse is 120/min, respirations are 12/min, and oxygen saturation is 98% on room air. He has dry, nontender, and circumferential burns over his arms bilaterally, burns over the anterior portion of his chest and abdomen, and tender spot burns with blisters on his shins. A 1L bolus of normal saline is administered and the patient is given morphine and his pulse is subsequently 80/min. A Foley catheter is placed which drains 10 mL of urine. What is the best next step in management?

Question: What is the best next step in management?

Answer: Additional fluids and escharotomy


Context: An 8-year-old girl is brought to the physician by her parents for the evaluation of an episode of unconsciousness while at the playground that morning. She was unconscious for about 15 seconds and did not shake, bite her tongue, or lose bowel or bladder control. Her grandfather died suddenly at the age of 29 of an unknown heart condition; her parents are both healthy. An ECG shows sinus rhythm and a QT interval corrected for heart rate (QTc) of 470 milliseconds. Laboratory studies are within normal limits. Which of the following is the most likely additional finding in this patient?

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

Answer: Sensorineural hearing loss


Context:
A 42-year-old woman presents to the emergency department with abdominal pain. Her pain started last night during dinner and has persisted. This morning, the patient felt very ill and her husband called emergency medical services. The patient has a past medical history of obesity, diabetes, and depression. Her temperature is 104°F (40°C), blood pressure is 90/65 mmHg, pulse is 160/min, respirations are 14/min, and oxygen saturation is 98% on room air. Physical exam is notable for a very ill appearing woman. Her skin is mildly yellow, and she is in an antalgic position on the stretcher. Laboratory values are ordered as seen below.

Hemoglobin: 13 g/dL
Hematocrit: 38%
Leukocyte count: 14,500 cells/mm^3 with normal differential
Platelet count: 257,000/mm^3

Alkaline phosphatase: 227 U/L
Bilirubin, total: 11.3 mg/dL
Bilirubin, direct: 9.8 mg/dL
AST: 42 U/L
ALT: 31 U/L

The patient is started on antibiotics and IV fluids. Which of the following is the best next step in management?

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

Answer: Endoscopic retrograde cholangiopancreatography


Context: A 45-year-old female is undergoing renal transplantation for management of chronic renal failure secondary to glomerulonephritis. The transplant surgeon placed the donor kidney in the recipient and anastamosed the donor renal artery to the recipient's external iliac artery as well as the donor ureter to the recipient's bladder. After removing the clamps on the external iliac artery, the recipient's blood is allowed to perfuse the transplanted kidney. Within 3 minutes, the surgeon notes that the kidney does not appear to be sufficiently perfused. Upon further investigation, an inflammatory reaction is noted that led to clotting off of the donor renal artery, preventing blood flow to the transplanted organ. Which of the following best describes the pathophysiology of this complication?

Question: Which of the following best describes the pathophysiology of this complication?

Answer: Type II hypersensitivity reaction


Context: A 68-year-old man is brought to the emergency department 30 minutes after the onset of uncontrollable jerking movements of his arms and legs followed by loss of consciousness. His wife says that he seemed confused this morning and had a headache. Immediately before the shaking episode, he said that he smelled rotten eggs. He is unresponsive. Cerebrospinal fluid (CSF) analysis shows a leukocyte count of 700/μL (70% lymphocytes), a glucose concentration of 60 mg/dL, and a protein concentration of 80 mg/dL. Despite appropriate lifesaving measures, the man dies. Which of the following is most likely to be found on postmortem examination of this patient?

Question: Which of the following is most likely to be found on postmortem examination of this patient?

Answer: Necrosis of the temporal lobes


Context: A 54-year-old man presents to the emergency department complaining of shortness of breath and fatigue for 1 day. He reports feeling increasingly tired. The medical records show a long history of intravenous drug abuse, and a past hospitalization for infective endocarditis 2 years ago. The echocardiography performed at that time showed vegetations on the tricuspid valve. The patient has not regularly attended his follow-up appointments. The visual inspection of the neck shows distension of the neck veins. What finding would you expect to see on this patient’s jugular venous pulse tracing?

Question: What finding would you expect to see on this patient’s jugular venous pulse tracing?

Answer: Obliterated x descent


Context: A 68-year-old man is brought to the emergency department by his wife because of a 2-week history of progressive disorientation and a 1-day history of left-sided weakness and difficulty speaking. The wife reports that the patient had a minor fall 4 months ago, during which he may have hit his head. He has hypertension and hyperlipidemia. He drinks 3–4 bottles of beer daily. He is only oriented to person. Neurological examination shows moderate spastic weakness, decreased sensation, and increased deep tendon reflexes in the left upper and lower extremities. A CT scan of the head is shown. Which of the following is the most likely cause of this patient's condition?

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

Answer: Tearing of bridging veins


Context: A 5-year-old boy with Down syndrome presents with his mother. The patient’s mother says that he isn’t playing or eating as much as he used to and seems lethargic. Expected developmental delays are present and stable. Physical examination reveals dry mucous membranes and abdominal distention with no tenderness to palpation. An abdominal radiograph is shown in the image below. Which of the following is the most likely diagnosis in this patient?

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

Answer: Hirschsprung's disease


Context: A 27-year-old man with an unknown past medical history is brought to the emergency department acutely intoxicated. The patient was found passed out in a park covered in vomit and urine. His temperature is 99.0°F (37.2°C), blood pressure is 107/68 mm Hg, pulse is 120/min, respiratory rate is 13/min, and oxygen saturation is 95% on room air. Physical exam is notable for wheezing in all lung fields without any crackles. The patient is started on 2L/min nasal cannula oxygen and IV fluids. His laboratory values are notable for an AST of 200 U/L and an ALT of 100 U/L. An initial chest radiograph is unremarkable. Which of the following is the most likely explanation for this patient's pulmonary symptoms?

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

Answer: Environmental antigen


Context:
A 24-year-old man presents to the emergency department for bloody stools. The patient states that he has had bloody diarrhea for the past 3 days without improvement. He recently returned from a camping trip where he drank stream water and admits to eating undercooked meats which included beef, chicken, pork, and salmon. The patient's father died at age 40 due to colon cancer, and his mother died of breast cancer at the age of 52. The patient lives alone and drinks socially. The patient has unprotected sex with multiple male partners. His temperature is 98.3°F (36.8°C), blood pressure is 107/58 mmHg, pulse is 127/min, respirations are 12/min, and oxygen saturation is 99% on room air. Laboratory values are ordered as seen below.

Hemoglobin: 9.2 g/dL
Hematocrit: 29%
Leukocyte count: 9,500/mm^3 with normal differential
Platelet count: 87,000/mm^3
Lactate dehydrogenase: 327 IU/L
Haptoglobin: 5 mg/dL

Serum:
Na+: 139 mEq/L
Cl-: 100 mEq/L
K+: 5.9 mEq/L
HCO3-: 19 mEq/L
BUN: 39 mg/dL
Glucose: 99 mg/dL
Creatinine: 1.1 mg/dL
Ca2+: 10.2 mg/dL

Which of the following is the most likely cause of this patient's presentation?

Question:
Hemoglobin: 9.2 g/dL
Hematocrit: 29%
Leukocyte count: 9,500/mm^3 with normal differential
Platelet count: 87,000/mm^3
Lactate dehydrogenase: 327 IU/L
Haptoglobin: 5 mg/dL

Serum:
Na+: 139 mEq/L
Cl-: 100 mEq/L
K+: 5.9 mEq/L
HCO3-: 19 mEq/L
BUN: 39 mg/dL
Glucose: 99 mg/dL
Creatinine: 1.1 mg/dL
Ca2+: 10.2 mg/dL

Which of the following is the most likely cause of this patient's presentation?

Answer: Escherichia coli


Context:
A 53-year-old woman is brought to the emergency department because of an episode of lightheadedness and left arm weakness for the last hour. Her symptoms were preceded by tremors, palpitations, and diaphoresis. During the past 3 months, she has had increased appetite and has gained 6.8 kg (15 lbs). She has hypertension, hyperlipidemia, anxiety disorder, and gastroesophageal reflux. She works as a nurse in an ICU and has been under more stress than usual. She does not smoke. She drinks 5 glasses of wine every week. Current medications include enalapril, atorvastatin, fluoxetine, and omeprazole. She is 168 cm (5 ft 6 in) tall and weighs 100 kg (220 lb); BMI is 36 kg/m2. Her temperature is 37°C (98.8°F), pulse is 78/min, and blood pressure is 130/80 mm Hg. Cardiopulmonary examination shows no abnormalities. The abdomen is soft and nontender. Fasting serum studies show:
Na+ 140 mEq/L
K+ 3.5 mEq/L
HCO3- 22 mEq/L
Creatinine 0.8 mg/dL
Glucose 37 mg/dL
Insulin 280 μU/mL (N=11–240)
Thyroid-stimulating hormone 2.8 μU/mL
C-peptide 4.9 ng/mL (N=0.8–3.1)
Urine screen for sulfonylurea is negative. Which of the following is the most likely diagnosis?"

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

Answer: Insulinoma


Context: A 56-year-old man presents to his primary care doctor to discuss his plans for diet and exercise. He currently has hypertension treated with thiazide diuretics but is otherwise healthy. On exam, his temperature is 98.8°F (37.1°C), blood pressure is 122/84 mmHg, pulse is 70/min, and respirations are 12/min. His weight is 95.2 kilograms and his BMI is 31.0 kg/m^2. The patient is recommended to follow a 2000 kilocalorie diet with a 30:55 caloric ratio of fat to carbohydrates. Based on this patient’s body mass index and weight, he is recommended to consume 75 grams of protein per day. Which of the following represents the approximate number of grams of carbohydrates the patient should consume per day?

Question: Which of the following represents the approximate number of grams of carbohydrates the patient should consume per day?

Answer: 275


Context: A 19-year-old man is rushed to the emergency department 30 minutes after diving head-first into a shallow pool of water from a cliff. He was placed on a spinal board and a rigid cervical collar was applied by the emergency medical technicians. On arrival, he is unconscious and withdraws all extremities to pain. His temperature is 36.7°C (98.1°F), pulse is 70/min, respirations are 8/min, and blood pressure is 102/70 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 96%. The pupils are equal and react sluggishly to light. There is a 3-cm (1.2-in) laceration over the forehead. The lungs are clear to auscultation. Cardiac examination shows no abnormalities. The abdomen is soft and nontender. There is a step-off palpated over the cervical spine. 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: Rapid sequence intubation


Context: A 72-year-old male with a past medical history significant for aortic stenosis and hypertension presents to the emergency department complaining of weakness for the past 3 weeks. He states that, apart from feeling weaker, he also has noted lightheadedness, pallor, and blood-streaked stools. The patient's vital signs are stable, and he is in no acute distress. Laboratory workup reveals that the patient is anemic. Fecal occult blood test is positive for bleeding. EGD was performed and did not reveal upper GI bleeding. Suspecting a lower GI bleed, a colonoscopy is performed after prepping the patient, and it is unremarkable. What would be an appropriate next step for localizing a lower GI bleed in this patient?

Question: What would be an appropriate next step for localizing a lower GI bleed in this patient?

Answer: Technetium-99 labelled erythrocyte scintigraphy


Context:
A 46-day-old baby is admitted to the pediatric ward with an elevated temperature, erosive periumbilical lesion, clear discharge from the umbilicus, and failure to thrive. She is the first child of a consanguineous couple born vaginally at 38 weeks gestation in an uncomplicated pregnancy. She was discharged home from the nursery within the first week of life without signs of infection or jaundice. The umbilical cord separated at 1 month of age with an increase in temperature and periumbilical inflammation that her mother treated with an herbal decoction. The vital signs are blood pressure 70/45 mm Hg, heart rate 129/min, respiratory rate 26/min, and temperature, 38.9°C (102.0°F). The baby's weight is between the 10th and 5th percentiles and her length is between the 50th and 75th percentiles for her age. The physical examination shows an erosive lesion with perifocal erythema in the periumbilical region with drainage but no pus. The rest of the examination is within normal limits for the patient’s age. The complete blood count shows the following results:
Erythrocytes 3.4 x 106/mm3
Hb 11 g/dL
Total leukocyte count
Neutrophils
Lymphocyte
Eosinophils
Monocytes
Basophils 49.200/mm3
61%
33%
2%
2%
2%
Platelet count 229,000/mm3
The umbilical discharge culture shows the growth of Staphylococcus aureus. Flow cytometry is performed for suspected primary immunodeficiency. The patient is shown to be CD18-deficient. Which of the following statements best describes the patient’s condition?

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

Answer: The patient’s leukocytes fail to adhere to the endothelium during their migration to the site of infection.


Context: An 8-year-old boy is brought to the physician because of a 7-day history of a progressively worsening cough. The cough occurs in spells and consists of around 5–10 coughs in succession. After each spell he takes a deep, noisy breath. He has vomited occasionally following a bout of coughing. He had a runny nose for a week before the cough started. His immunization records are unavailable. He lives in an apartment with his father, mother, and his 2-week-old sister. The mother was given a Tdap vaccination 11 years ago. The father's vaccination records are unavailable. His temperature is 37.8°C (100.0°F). Examination shows no abnormalities. His leukocyte count is 42,000/mm3. Throat swab culture and PCR results are pending. Which of the following are the most appropriate recommendations for this family?

Question: Which of the following are the most appropriate recommendations for this family?

Answer: Administer oral azithromycin to all family members and Tdap vaccination to the father and mother


Context: An investigator is studying the recycling of heme proteins in various cell types. Heat denaturation and high-performance liquid chromatography are used to carry out and observe the selective destruction of hemoglobin molecules in red blood cells. It is found that these cells are unable to regenerate new heme molecules. A lack of which of the following structures is the most likely explanation for this observation?

Question: A lack of which of the following structures is the most likely explanation for this observation?

Answer: Mitochondria


Context: A 7-year-old boy is brought to the emergency department by his parents for worsening symptoms. The patient recently saw his pediatrician for an acute episode of sinusitis. At the time, the pediatrician prescribed decongestants and sent the patient home. Since then, the patient has developed a nasal discharge with worsening pain. The patient has a past medical history of asthma which is well controlled with albuterol. His temperature is 99.5°F (37.5°C), blood pressure is 90/48 mmHg, pulse is 124/min, respirations are 17/min, and oxygen saturation is 98% on room air. On physical exam, you note a healthy young boy. Cardiopulmonary exam is within normal limits. Inspection of the patient's nose reveals a unilateral purulent discharge mixed with blood. The rest of the patient's exam is within normal limits. Which of the following is the most likely diagnosis?

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

Answer: Foreign body obstruction


Context: A 24-year-old woman delivers a girl by normal vaginal delivery, Apgar scores are 8 and 9 at 1 and 5 minutes respectively. The newborn’s vitals are normal. On examination, the attending pediatrician finds a circular skin defect that measures 0.5 cm in diameter. The defect is hairless and extends into the dermis. The delivery was atraumatic and there were no surgical instruments in the area. The pediatric team believes this is a congenital defect. The remaining examination is normal. The mother gives past history of having constant diarrhea for 3 months about 2 years ago, weight loss of 5 kg (11 lb) in 3 months, palpitations, and sensitivity to heat. She visited a community hospital and was prescribed a medication for this problem. She did not visit the hospital for any of her routine check-ups and continued taking her medications. Which drug can predispose the newborn to this condition?

Question: Which drug can predispose the newborn to this condition?

Answer: Methimazole


Context: A 63-year-old man comes to the physician because of a 2-day history of a painful rash on his right flank. Two years ago, he underwent cadaveric renal transplantation. Current medications include tacrolimus, mycophenolate mofetil, and prednisone. Examination shows an erythematous rash with grouped vesicles in a band-like distribution over the patient's right flank. This patient is at greatest risk for which of the following complications?

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

Answer: Sensory neuropathy


Context: A 16-year-old girl is brought to the emergency room with hyperextension of the cervical spine caused by a trampoline injury. After ruling out the possibility of hemorrhagic shock, she is diagnosed with quadriplegia with neurogenic shock. The physical examination is most likely to reveal which of the following constellation of findings?

Question: The physical examination is most likely to reveal which of the following constellation of findings?

Answer: Pulse: 56/min; blood pressure: 88/40 mm Hg; respirations: 22/min; loss of rectal tone on DRE; reduced muscle power and absence of sensations in the limbs


Context: A 64-year-old woman presents to the clinic with a history of 3 fractures in the past year with the last one being last month. Her bone-density screening from last year reported a T-score of -3.1 and she was diagnosed with osteoporosis. She was advised to quit smoking and was asked to adapt to a healthy lifestyle to which she complied. She was also given calcium and vitamin D supplements. After a detailed discussion with the patient, the physician decides to start her on weekly alendronate. Which of the following statements best describes this patient’s new therapy?

Question: Which of the following statements best describes this patient’s new therapy?

Answer: The patient must stay upright for at least 30 minutes after taking this medication


Context: A 27-year-old woman comes to the physician for a routine health maintenance examination. She feels well. She had a chlamydia infection at the age of 22 years that was treated. Her only medication is an oral contraceptive. She has smoked one pack of cigarettes daily for 6 years. She has recently been sexually active with 3 male partners and uses condoms inconsistently. Her last Pap test was 4 years ago and results were normal. Physical examination shows no abnormalities. A Pap test shows atypical squamous cells of undetermined significance. 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: Perform HPV testing