A 16-year-old boy presents to his primary care doctor due to a 1-month history of blurry vision. His family recently immigrated to the United States. Review of his medical record reveals that he has had multiple recent hospitalizations for sinopulmonary infections. On physical exam, temperature is 98.6°F (37°C), blood pressure is 110/80 mmHg, pulse is 68/min, and respirations are 12/min. Auscultation of the lungs reveals diffuse wheezing. Examination of the eyes is shown in Figure A. Deficiency in which of the following is most likely responsible for this patient's presentation?

A scientist is studying how a novel virus is able to rapidly replicate in host cells. She discovers that the virus needs to make certain proteins in a specific 2:2:1 ratio in order to assemble correctly. She also discovers that the virus genome is composed of DNA that is recognized by the human transcription machinery in order to produce messenger RNA (mRNA). Interestingly, when the transcripts are translated by ribosomes, this exact ratio is always maintained irrespective of how many transcripts are created. Which of the following genetic characteristics is most likely responsible for this feature of the virus?

A 52-year-old man presents to his primary care physician with a 3-month history of increasing fatigue. He first started noticing the fatigue when he found that he was having increasing difficulty keeping up with his friends while playing golf. He states that the fatigue has progressed to the point where he feels weary with little energy after getting home from a day of work. He also complains of indigestion and bloating. His wife has noted that he appears abnormally pale despite it being the middle of summer. He has no past medical history and eats a diverse diet. Labs are obtained with the following results: Hemoglobin: 8.7 g/dL Mean corpuscular volume: 114 µm^3 Which of the additional laboratory values seen in Figure A would most likely also be found in this patient?

A 28-year-old man is brought to the emergency department by ambulance after he was found unresponsive in the snow on the sidewalk. His past medical history is significant for multiple forms of substance use disorder, but no collateral information is able to be obtained with regards to which substances were most recently used. On physical exam, the patient is somnolent and is only arousable to pain. He is also found to have fixed contracted pinpoint pupils. Which of the following sets of vital signs seen in Figure A would most likely be seen in this patient?

A 10-year-old girl is brought to her pediatrician by her mother with complaint of a new-onset rash on both of her lower extremities. Her past medical history is significant for asthma and an episode of pneumonia 3 months ago. Per her mother, the patient recently returned from a school field trip to a farm a few days ago. The class fed barn animals, played hide-and-seek in the woods, and picked wild blackberries. Apart from severe pruritus and some pain in the area of her rash, the patient has no other complaints. Her temperature is 98.6°F (37°C), blood pressure is 114/65 mmHg, pulse is 75/min, and respirations are 14/min. Physical examination reveals the findings shown in Figure A. Which of the following most accurately describes the histological findings of the patient’s condition?

A research team is studying the effect of endoscopic carpal tunnel surgery on complication rates following surgery, compared to the traditional open approach. Due to the potential morbidity associated with infections, the team is interested in comparing the incidence of surgical site infections (SSIs) after these types of carpal tunnel surgery. They are designing a retrospective cohort study and estimate that they will require 2,456 patients in each cohort to detect a 1 percentage-point increase in SSI incidence (baseline incidence: 1%) with at least 80% power. They set the threshold for statistical significance at p < 0.001. Which of the following is the best interpretation of the statistical values given?

A team of researchers is investigating whether differences exist in the incidence of acute kidney injury between obese and non-obese patients who are hospitalized with a respiratory virus infection. With institutional review board approval, the researchers prospectively enroll 450 obese and 1,560 non-obese patients in their study after obtaining informed consent. At hospital admission, each patient receives a serum creatinine measurement. Serum creatinine measurements are repeated daily during the admission. The researchers calculate the change in serum creatinine concentration from admission to hospital day 2 for each patient. The average change is shown for each cohort: Non-obese cohort: +0.14 mg/dL (95% confidence interval: 0.09-0.20 mg/dL) Obese cohort: +0.34 mg/dL (95% confidence interval: 0.09-0.54 mg/dL) Which of the following is true regarding the accuracy and precision of the estimate for average change for the 2 cohorts?

A 65-year-old woman is brought to the emergency department for somnolence. She was found to be disoriented to person, place, and time this morning at her nursing facility. Last night, she had complained of mild suprapubic discomfort. She has a history of hypertension, hyperlipidemia, and diabetes for which she takes amlodipine, atorvastatin, and insulin, respectively. The patient’s temperature is 103.9°F (39.9°C), blood pressure is 90/60 mmHg, pulse is 112/min, and respirations are 24/min. Physical exam reveals suprapubic and right costovertebral angle tenderness. Laboratory studies are obtained and reveal a C-reactive protein concentration of 5.2 mg/L (reference: <3.0 mg/L) and ferritin concentration of 300 ng/mL. Which of the following cytokines is most directly responsible for these laboratory abnormalities?

A 65-year-old man is referred to an ophthalmologist due to a few weeks of bilateral worsening vision. He states that he has never trusted doctors, but decided to come in since he was scared about not seeing well. His medical history is significant for hypertension and 40-pack-year smoking history. Apart from the patient’s current symptoms, he does have any other complaints. His temperature is 98.6°F (37°C), blood pressure is 145/75 mmHg, pulse is 75/min, and respirations are 13/min. On examination, the patient’s visual acuity is slightly decreased per Snellen chart. Tonometry indicates elevated intraocular pressure bilaterally; enlarged cup-to-disc ratios are also observed on funduscopic exam. The physician prescribes a medication for outpatient use. However, after his first use, the patient develops dyspnea, coughing, and fatigue. What is the therapeutic mechanism of the medication?

A 26-year-old woman visits her primary care physician for an annual checkup. Her medical history is significant only for major depression, which has been in remission for several years in the setting of consistently taking bupropion. When asking the patient about her home life, she discloses having some difficulty in her marriage stemming from her having no sexual desire over the past 2 years. Her husband attempts to initiate intercourse about once a month, but she experiences little excitement or pleasure during these times. She loves her husband but has begun wondering whether her husband may be having an affair due to his frustration. On review of systems, she endorses feeling more sleepy and stressed, as she started a new job last week. Physical exam of genitalia are unrevealing, with no lesions or pain with speculum examination. Which of the following diagnoses most likely explains this patient's symptoms?

A 5-year-old boy is brought to a rural health clinic with a 1-week history of low-grade fever and a red lesion on his right leg. His parents say that they noticed a small lesion on his right leg after they returned from a neighboring village, where they traveled to celebrate a wedding. The lesion went away after a few days but he continued to have fever and irritability since then. His temperature is 100.4°F (38°C), blood pressure is 105/61 mmHg, pulse is 92/min, and respirations are 17/min. Physical exam reveals the finding shown in Figure A. Which of the following would be the most likely long-term consequence if this patient's disease remains untreated?

A 28-year-old man is brought to the emergency department in cardiac arrest after a motorcycle accident. Despite high-quality cardiopulmonary resuscitation (CPR) and adherence to the advanced cardiac life support (ACLS) algorithm, no pulse can be recovered and the patient is pronounced dead an hour later. The physician in charge of the code must then inform the parents of the patient regarding his death. Which of the following is the most appropriate statement for addressing this situation?

A 71-year-old man with a history of human immunodeficiency virus (HIV) infection presents to his primary care physician for follow-up 3 months after starting a new medication regimen. His previous medications were no longer covered by his insurance, so one of the components of his therapy was switched at the previous visit. His past medical history is also significant for atrial fibrillation for which he has taken a stable dose of warfarin for years. He has no history of diabetes, hyperlipidemia, or hypertension. Selected interval laboratory results since switching his medication are shown below: Fasting serum: Glucose: 171 mg/dL Triglycerides: 221 mg/dL Coagulation studies: International normalized ratio (INR): 3.8 Which of the following medications was most likely started in this patient?

A researcher is studying a novel targeted therapy against a rare form of kidney cancer. She finds that the therapeutic compound binds to a specific protein that is over-expressed on the plasma membrane of neoplastic cells. The drug does not affect the function of this overexpressed protein; however, when administered to a rodent model of the disease, the drug leads to the recruitment of NK cells and apoptosis of the neoplastic cells. The therapy that is being studied in this case has a mechanism of action most similar to which of the following drugs?

A 29-year-old woman undergoes elective spine surgery for a herniated disc that is causing left-sided C6 radiculopathic symptoms. Her surgeon elects to perform a 1-level anterior corpectomy, discectomy, and fusion procedure. During anesthesia induction, the patient has an adverse reaction that is attributed to malignant hyperthermia, and despite maximum medical treatment, she develops cardiopulmonary arrest in the operating room. She is unable to be resuscitated. Afterwards, her parents angrily state to the attending surgeon, "We are furious about the care she received and believe there must have been a mistake because she was young and healthy and had no reason to die like this." What is the most appropriate response by the physician at this time?

A 55-year-old man presents to his primary care physician for an annual exam. His only complaint is constant fatigue and inability to stay awake during the day for the past 6 months despite sleeping for 8 hours nightly. He denies fever, chills, or unintentional weight loss. His medical problems include hypertension, diabetes mellitus, and hypothyroidism for which he takes amlodipine, hydrochlorothiazide, metformin, and levothyroxine. He is a former smoker with a 40 pack-year smoking history. The patient’s temperature is 98.6°F (37.0°C), blood pressure is 138/78 mmHg, pulse is 96/min, and respirations are 18/min. Body mass index (BMI) is 38 kg/m^2. Physical examination reveals a tired-appearing man with a thick neck. Lung fields are clear to auscultation. Thyroid-stimulating hormone (TSH) level is 1.2 µU/mL. Which of the following complications is this patient at greatest risk of developing?

A 34-year-old man is brought to the emergency department by ambulance for altered mental status. He was found after he fell on the sidewalk with somnolence and slurred speech. He has had multiple prior emergency department visits for the same symptoms. He has a history of depression treated with fluoxetine. Physical exam reveals horizontal nystagmus. His serum osmolal gap is 20 mOsm/L (reference: <10 mOsm/L). He is treated for his condition and counseled appropriately. Because of unstable housing, he is discharged to a temporary housing facility. He is brought to the emergency department again 3 days later by ambulance with visual hallucinations. He was found to be agitated by his roommate, who called the police. There is no nausea or vomiting. The patient’s temperature is 102.6°F (39.2°C), blood pressure is 154/78 mmHg, pulse is 112/min, and respirations are 18/min. Physical exam reveals diaphoresis without nuchal rigidity. Patellar and ankle reflexes are 2+ bilaterally. Which of the following is the most likely diagnosis?

A 48-year-old woman presents to her primary care physician for an annual exam. She has no acute medical complaints today. She has diabetes mellitus and hypothyroidism for which she takes metformin and levothyroxine. Her immunizations are up to date. She quit smoking 10 years ago and has a 45 pack-year history. She drinks alcohol socially and denies illicit drug use. The patient’s temperature is 98.6°F (37.0°C), blood pressure is 144/82 mmHg, pulse is 82/min, and respirations are 16/min. A review of her chart shows that her blood pressure was 148/70 mmHg 3 months ago. On physical exam, her lung fields are clear to auscultation bilaterally. No murmurs, rubs, or gallops are heard on cardiac auscultation. She is started on the most appropriate medication for her blood pressure and advised that it can cause a non-productive cough. Which of the following changes are expected after initiation of this medication (Figure A)?

A 23-year-old man is brought to the emergency department by ambulance after a motorcycle collision. During his trauma evaluation, he requires a large number of computed tomography scans in order to properly identify all of his injuries. The medical student on the emergency medicine rotation asks whether there are harmful effects to administering so many scans to this patient. The answer to this student's question most likely involves which of the following DNA findings?

A 35-year-old woman presents to her primary care physician for an annual physical exam. She has infrequent headaches that resolve with acetaminophen but no other medical complaints. Her medical history includes asthma and diabetes. She has an albuterol rescue inhaler and takes metformin. She drinks alcohol socially and does not smoke cigarettes. The patient's temperature is 98.6°F (37.0°C), blood pressure is 154/82 mmHg, pulse is 70/min and regular, and respirations are 16/min. Her lung fields are clear to auscultation bilaterally. Heart sounds are normal without murmurs, rubs, or gallops. There is no lower extremity edema. Serum laboratory results are as follows: Na+: 136 mEq/L Cl-: 97 mEq/L K+: 3.0 mEq/L HCO3-: 32 mEq/L BUN: 16 mg/dL Glucose: 110 mg/dL Creatinine: 0.8 mg/dL What is the most appropriate treatment for this patient's condition?

A 10-year-old boy is brought to the pediatrician for complaints of scalp itching. The patient’s mother states that several classmates have also had similar symptoms. He reports no other symptoms. His vital signs are normal. On examination of the patient’s head, there are tiny white objects attached to the base of many hair shafts. Treatment should most likely be initiated against which of the following?

A 57-year-old woman presents to her physician for progressively worsening, unilateral, left-sided nipple rash and pruritus, as well as bloody nipple discharge for 2 months. The pruritus has not improved with over-the-counter hydrocortisone. Her maternal grandmother developed breast cancer at 61 years of age, and her maternal aunt developed breast cancer at 52 years of age. Her temperature is 98.6°F (37.0°C), blood pressure is 125/80 mmHg, pulse is 80/min, respirations are 12/min. Physical exam reveals a small firm, fixed mass in the upper outer quadrant of the left breast. Which of the following pathological findings (Figures A-E) would be expected on a biopsy of the skin lesion on the breast?

A 15-year-old boy is brought to the emergency department by his mother for left knee pain. His knee felt inflamed and became swollen 2 days ago. The swelling has progressed despite around-the-clock ibuprofen. He denies any recent or prior injury to the affected joint. He has no medical problems. There is no family history of malignancy. He plays soccer and is sexually active with 3 female partners. His body mass index (BMI) is 21 kg/m^2. The patient’s temperature is 101.4°F (38.6°C), blood pressure is 120/80 mmHg, pulse is 99/min, and respirations are 18/min. A physical exam is remarkable for a severely limited range of motion of the left knee due to pain. The right knee has normal flexion and extension. A joint aspiration is performed with the following findings: Color: Yellow Appearance: Cloudy Leukocyte count: 50,000/mm^3 with polymorphonuclear predominance Gram stain: No organisms seen What is the most likely etiologic organism of this patient’s condition?

A 31-year-old woman presents to the emergency room with 2 days of dysuria, increased urinary frequency, and suprapubic pain. She denies chills, rigors, or significant fatigue. The patient has 1 new recent sexual partner and occasionally uses condoms. She has never been hospitalized and has never traveled internationally. Her temperature is 98.6°F (37.0°C), blood pressure is 125/85 mmHg, pulse is 85/min, and respirations are 15/min. A physical exam is significant for suprapubic pain but no costovertebral tenderness. Laboratory studies show a white blood cell count of 11,200 cells/mm^3. A pregnancy test is negative. Which of the following is a mechanism of action of an appropriate outpatient antimicrobial agent for this patient?

A 75-year-old man is brought to the emergency department by his daughter for dull right-sided flank pain. The pain began around 3 months ago and has progressed steadily since then. He has not had fever or chills. He was recently diagnosed with right-sided renal cell carcinoma with extensive metastatic disease. He was strongly considering hospice at that time but asked for time to consider his options with his family. There are no other pertinent medical conditions. He takes no medications. He has a 90-pack-year smoking history and quit 5 years ago. He is not married. The patient’s temperature is 98.2°F (36.8°C), blood pressure is 110/70 mmHg, pulse is 90/min, and respirations are 18/min. He appears comfortable but tearful, anxious, and sad. He is alerted and oriented to person, place, and time. There are no ecchymoses on his extremities. He has dull pain with percussion of the right costovertebral angle. His daughter states that they would like to consider resection of the renal mass. A surgical consult is obtained and the risks, benefits, and alternatives of the procedure are explained. The patient expresses understanding in his own words but remains quiet when asked if he has further questions. The daughter asks when the surgery can be performed. An informed consent form is prepared and the patient is asked to sign. Which of the core principles of informed consent has been inadequately assessed?

A 41-year-old woman presents to an ophthalmologist with a 2-month history of feeling like she is having increasing difficulty seeing things while driving at nighttime. She also notes that her eyes feel “gritty” and that her skin feels drier than normal. The patient has no personal or family history of rheumatologic or eye disease. On exam, her vision is 20/25 in both eyes, intraocular pressure is 13 mmHg in both eyes (normal 10-21 mmHg), and pupils are 5 mm in the dark and constrict sluggishly bilaterally. Small, raised, grey-white lesions are also noted on the temporal conjunctiva of both eyes as seen in Figure A. Which of the following is most likely to be associated with this patient’s presentation?

A 35-year old man with severe sepsis is admitted to the intensive care unit. His temperature is 101.2°F (38.4°C), blood pressure is 82/53 mmHg, pulse is 120/min, and respirations are 20/min. A central venous catheter is placed. Which of the following would most likely decrease the risk of complications from this procedure?

A 74-year-old man presents to the emergency department with a 2-month history of low back pain and constipation. He has no known past medical history but has not seen a doctor in over 20 years. He has smoked 2 packs per day for 40 years and drinks 3-4 beers per night. A physical exam is unrevealing, but imaging demonstrates a large pelvic mass as well as widely dispersed lesions of unknown origin. An image-guided biopsy is obtained, and histology of the tissue is seen in Figure A. Which of the following types of lymph nodes were most likely first involved in this patient's pathology?

A 78-year-old man presents to his primary care physician for his yearly wellness visit. He says that he has been feeling well overall and does not have any new complaints. His past medical history is significant for hypertension and hyperlipidemia for which he is currently taking metformin and atorvastatin. His social history is significant for a 5-pack-year history of smoking but he quit 30 years ago. His temperature is 98.6°F (37°C), blood pressure is 141/86 mmHg, pulse is 82/min, and respirations are 14/min. His body mass index is 24. Physical exam reveals no evidence of coronal or sagittal plane spinal deformity. Pulmonary exam is unremarkable. Compared to baseline results that were obtained when the patient was 50 years old, which of the sets of changes would most likely be seen in this patient's pulmonary function tests?

A 1-day-old infant is evaluated in the neonatal intensive care unit for cyanosis. He was born to a 28-year-old G1P1 woman and started to have difficulty breathing immediately upon birth. He is placed on oxygen and transferred to the intensive care unit for further evaluation. An echocardiogram is performed demonstrating the absence of a posterior interventricular septum and an aberrant tunnel structure supplied by the left anterior descending artery that connects to the aorta. This structure most likely originates from which of the following regions of the heart?

A 34-year-old man is brought to the emergency department after he was found down in a city park. He has no identifying information and the circumstances surrounding his current presentation are unknown. His temperature is 102.2°F (39.0°C), blood pressure is 102/64 mmHg, pulse is 116/min, and respirations are 14/min. A large wound is present on his left leg and he is started empirically on antibiotic treatment. One day later, he is found to be hypoxic to 83% on room air and he requires escalating respiratory support including mechanical ventilation. A chest radiograph obtained at this time is shown in Figure A. Which of the following is the most likely cause of this patient's respiratory difficulties?

A 16-year-old girl is brought to her pediatrician by her mother for a well child examination. The patient has no acute complaints or symptoms. Her medical problems consist of asthma for which she uses an albuterol inhaler as needed. She takes no other medications. She received surgery during infancy for malrotation of the intestines. She has received an up-to-date childhood vaccination series, including 1 dose of meningococcal vaccine. There is no family history of sudden cardiac death or malignancies. The patient is in the 11th grade and does well academically. After her mother is asked to leave the room, the patient states she has tried alcohol and marijuana once in the past but did not like them. She denies tobacco use. She is sexually active with her boyfriend and uses barrier contraception. She feels that over the past 6 months, she has “lost control” of her eating and eats large amounts of food quickly. She feels she “can’t stop eating” even though she feels disgusted with herself afterwards. She exercises 3 times a week for 1 hour each to lose weight. The patient’s temperature is 98.6°F (37.0°C), blood pressure is 110/60 mmHg, pulse is 90/min, and respirations are 16/min. Her body mass index is 20.9 kg/m^2. Her teeth are in good condition. Cardiopulmonary auscultation is unremarkable. There are no skin lesions on her extremities or torso. Which of the following is the most likely diagnosis?

A group of medical students are studying the effects of a new injection for the treatment of stenosing tenosynovitis. They enroll 200 patients with this disease in a randomized fashion with 100 being treated with the new injection and the others being treated with a traditional corticosteroid injection. They find that 90 of the patients treated with the new injection have complete resolution of symptoms whereas 75 of the patients treated with the corticosteroid injection have similar resolution of symptoms. Compared with corticosteroids, which of the following is the number needed to treat with the new injection?

A 58-year-old man presents to the emergency department with acute onset vision loss in his left eye. The patient is a university professor. Approximately 30 minutes ago, he was delivering a lecture when he suddenly noticed decreased vision in his left eye. The decrease in vision happened over a period of a few seconds and was not associated with pain. The patient’s past medical history is significant for hypertension, hypercholesterolemia, diabetes, and bilateral osteoarthritis of the knees. His medications include atorvastatin, lisinopril, metformin, and semaglutide. He is unsure of his family history but notes his mother is of Ashkenazi Jewish descent. He quit smoking 10 years ago, but previously smoked half a pack of cigarettes per day for 30 years. His temperature is 98.6°F (37.0°C), blood pressure is 132/70 mmHg, pulse is 87/min, respirations are 16/min, and O2 saturation is 99% on room air. His BMI is 33 kg/m^2. Eye exam reveals 20/20 vision in the right eye and he is only able to count fingers at 3 feet in the left eye. The intraocular pressure is 14 mmHg in both eyes (normal 12-21 mmHg). Indirect ophthalmoscopy reveals the findings shown in Figure A. Which of the following is the most likely diagnosis in this patient?

Researchers are studying a common pathogenic bacterium. They isolate the organism of interest on a culture medium that contains Mueller-Hinton agar, 5% chocolate sheep blood, vancomycin, polymyxin, nystatin, and trimethoprim. Which of the following is an infection most commonly associated with the organisms that grow in this culture medium?

A 45-year-old woman presents to the emergency room with a headache. The headache had an acute onset 30 minutes before admission and has not improved with ibuprofen. She has occasionally had headaches, but nothing as severe as the current episode. Her past medical history is significant for hypertension and Ehlers-Danlos syndrome. She does not drink alcohol but has smoked 2 packs of cigarettes per day for the past 25 years. Her temperature is 98.6°F (37.0°C), blood pressure is 175/95 mmHg, pulse is 115/min, respirations are 22/min, and O2 saturation is 99% on room air. A brief physical exam is notable for photophobia and nuchal rigidity. No focal neurologic deficits are noted. Computed tomography (CT) scan of the head is notable for blood in the interpeduncular, crural, ambient, and quadrigeminal cisterns. Which of the following is the most likely cause of this patient’s current presentation?

A 68-year-old man is brought to the emergency room by his wife for confusion. The patient had sudden onset of fever, headache, and myalgias 3 days before presentation. He has also had diarrhea, abdominal pain, neck pain, and photophobia. In the past day, he has been increasingly confused and weak. He has not traveled recently or been in contact with anyone sick. His past medical history is significant for obesity, hypertension, hyperlipidemia, type 2 diabetes mellitus, heart failure with preserved ejection fraction, obstructive sleep apnea, and osteoarthritis. His medications include dapagliflozin, diclofenac gel, furosemide, losartan, metformin, rosuvastatin, and tirzepatide. He drinks 1-2 beers daily and does not use tobacco. He works as a project manager for a software company, and he lives in southern California. His temperature is 101.2°F (38.4°C), blood pressure is 135/70 mmHg, pulse is 100/min, respirations are 18/min, and O2 saturation is 99% on room air. The cardiopulmonary examination is notable for regular tachycardia. He is intermittently attentive and oriented to person and place, but not to time. Neurologic examination is significant for increased tone, bradykinesia, a coarse tremor, and 3/5 strength in the lower extremities. A maculopapular rash is noted on the chest, back, and arms. A lumbar puncture is performed, which demonstrates normal opening pressure, clear cerebrospinal fluid, white blood cell count of 20/mm^3 (mostly monocytes), protein of 75 mg/dL, and a glucose of 65 mg/dL. Which of the following is the most likely cause of this patient’s symptoms?

A 35-year-old man presents to urgent care with 1 week of cough productive of brown sputum and shortness of breath. The patient has also had myalgias and fatigue. The patient has been taking his as-needed budesonide-formoterol inhaler more frequently without significant relief of symptoms. His past medical history is significant for asthma and human immunodeficiency virus (HIV) infection. His medications include both scheduled and as-needed budesonide-formoterol, as well as a bictegravir, emtricitabine, and tenofovir combination medication. He has no past surgical history. He lives in New York and works as a software engineer. He recently visited Chicago for a conference; otherwise, he has not traveled for the past 3 years. He does not drink alcohol, smoke tobacco, or use other recreational drugs. His temperature is 100.8°F (38.2°C), blood pressure is 110/65 mmHg, pulse is 80/min, respirations are 20/min, and O2 saturation is 94% on room air. Physical examination is notable for inspiratory wheezing bilaterally. Laboratory studies show: Leukocyte count: 13,000 cells/mm^3 Segmented neutrophils: 54% Bands: 3% Eosinophils: 11% Basophils: 0.5% Lymphocytes: 27% Monocytes: 5% CD4+ T-cell count: 650 cells/mm^3 Serum immunoglobulin E (IgE): 1,300 IU/mL High-resolution computed tomography (CT) scan of the chest shows widespread proximal bronchiectasis, predominantly in the upper lobes. Which of the following organisms is most likely associated with this patient’s symptoms?

A 32-year-old G2P1 woman presents to her obstetrician at 32 weeks of gestation for a routine prenatal appointment. Her pregnancy has been uncomplicated thus far. She has no complaints other than increased urinary frequency. She denies dysuria or nocturia. She records fetal kicks daily and has consistently noticed more than 10 kicks in 2 hours. Her previous child was delivered at term via spontaneous vaginal delivery. She has no past medical history including no history of diabetes or kidney disease. Her only medication is a multivitamin. Her temperature is 98.6°F (37.0°C), blood pressure is 115/70 mmHg, pulse is 85/min, respirations are 22/min, and O2 saturation is 97% on room air. Physical examination is notable for a fundal height consistent with 32 weeks of gestation, as well as a systolic ejection murmur. Fetal Doppler ultrasound shows a fetal heart rate of 150/min. A urinalysis shows: Bacteria: absent Leukocyte esterase: negative Nitrite: negative Ketones: negative White blood cells (WBC): 2 cells/HPF Red blood cells (RBC): 0-1 cells/HPF Urine epithelium: 4 cells/HPF pH: 5.5 Protein: 2+ Compared to prior to pregnancy, which of the following physiological parameters would be expected in this patient?

A 29-year-old woman presents to the emergency department with a 1-day history of itching on her leg. She says that she recently cut herself while walking in the woods but does not recall any exposures that she is aware of. She put a bandage on the cut but started experiencing itching the next morning. Her past medical history is significant for seasonal allergies and she does not currently take any medications. Her temperature is 98.6°F (37°C), blood pressure is 115/72 mmHg, pulse is 81/min, and respirations are 12/min. Oh physical exam, she is found to have a pruritic, erythematous rash under the bandage as seen in Figure A. Which of the following would be the most likely histology finding if this lesion were biopsied?

A 4-year-old boy is brought to the emergency department by his mother for severe right leg pain. The pain began suddenly 6 hours ago and has been unremitting. He has been well other than having a mild nonproductive cough and runny nose 1 week ago that resolved 2 days ago. The patient has a history of asthma and sickle cell disease, for which he takes hydroxyurea, penicillin, and an albuterol inhaler as needed. He has not had any prior surgeries. He is up to date on his vaccinations, including pneumococcal, influenza, and meningococcal vaccines. He lives with his parents and has 2 siblings, who are healthy. The patient’s temperature is 98.6°F (37.0°C), blood pressure is 98/56 mmHg, pulse is 140/min, and respirations are 22/min. Physical examination shows a tearful boy holding his right calf in pain. A cardiopulmonary examination is unremarkable. His abdomen is soft, nontender, and nondistended. His right calf is diffusely painful without focal tenderness. There is no overlying erythema in the affected extremity. Passive range of motion of his right hip, knee, and ankle are full. He refuses to participate in the gait exam. The results of serum laboratory results are shown below: Hemoglobin: 9.2 g/dL Platelet count: 160,000/mm^3 Reticulocyte count: 5% Erythrocyte sedimentation rate (ESR): 10 mm/h Radiographs of the right tibia, fibula, and ankle are unremarkable. Which of the following is most likely to be decreased in this patient?

A 78-year-old woman is brought to the emergency department by ambulance for altered mental status. She is a resident at a skilled nursing facility, where she was noted to have lower abdominal discomfort 3 days ago. She had 1 episode of urinary incontinence on each of the last 2 nights. This morning, she was found to be disoriented to place and time. The patient has a history of diabetes mellitus, hypertension, and congestive heart failure for which she takes metformin, insulin, lisinopril, metoprolol, and spironolactone. She also had a stroke 3 years ago that left her with residual dysarthria. She received a left total knee arthroplasty 20 days ago. She is up to date on her vaccinations, including herpes zoster. She has a 30-pack-year smoking history and quit 15 years ago. She does not drink alcohol. She has a history of intravenous drug use. She is a retired librarian. The patient's temperature is 103.6°F (39.8°C), blood pressure is 90/56 mmHg, pulse is 120/min, and respirations are 22/min. Physical examination reveals an ill-appearing woman. She is oriented only to person. Cardiac exam reveals a normal S1 and S2 with an S4 gallop. There are no murmurs or rubs. Bronchial breath sounds are heard bilaterally. Her abdomen is soft and nondistended. There is right costovertebral angle tenderness. Which of the following is the most likely cause of this patient's condition?

A 28-year-old woman presents to the emergency department with sudden-onset, severe pelvic pain. The pain began 1 hour ago and there were no apparent inciting factors. The patient had been feeling well otherwise, without fever, chills, or vaginal bleeding. Since the pain began, she has experienced waves of nausea with some vomiting. She has a history of exercise-induced asthma for which she uses an albuterol inhaler. Six months ago, her gynecologist discovered a 5-cm cystic mass on her left ovary. The mass was round, anechoic in appearance, and had no evidence of internal flow on Doppler ultrasonography. The gynecologist recommended surveillance of the cyst. The patient has no surgical history. She does not smoke cigarettes, drinks alcohol socially, and does not use illicit drugs. She works as a teacher. She is sexually active with 3 men and intermittently uses condoms. The patient's temperature is 100.1°F (37.8°C), blood pressure is 120/80 mmHg, pulse is 110/min, and respirations are 20/min. Physical examination reveals a woman in acute pain. Cardiac auscultation reveals a normal S1 and S2. Her lung fields are clear bilaterally. Her abdomen is soft and nondistended. There is pain on deep palpation of her lower abdomen but no masses are palpated. A transabdominal ultrasound is obtained, showing a diffusely enlarged left ovary. A urine beta-human chorionic gonadotropin (beta-hCG) test is negative. Which of the following is the most likely diagnosis?

A 48-year-old woman presents to the physician with poorly controlled blood pressure. She measures her blood pressures at home and they have intermittently been in the 170-190/80-90 mmHg range. The patient endorses intermittent palpitations and diaphoresis. She denies fever, cough, or dysuria. The patient has a history of hypertension, hyperlipidemia, and asthma. Her medications consist of lisinopril, amlodipine, hydrochlorothiazide, rosuvastatin, and an as-needed albuterol inhaler. She received a left anterior cruciate ligament reconstruction 10 years ago. She has a 40-pack-year smoking history but quit 5 years ago. She does not drink alcohol or use illicit drugs. The patient's temperature is 98.6°F (37.0°C), blood pressure is 110/70 mmHg, pulse is 80/min, and respirations are 16/min. Cardiopulmonary exam discloses a normal S1 and S2 without murmurs and clear bilateral lung fields. Her abdomen is soft and nontender. Serum and urine metanephrines are elevated. The patient is diagnosed with an isolated, benign adrenal tumor. Despite recommendations for curative surgical treatment and its risks and benefits, the patient states that her relative died from a surgical complication and she would like to use an herbal remedy only, that she read about. Which of the following is the most appropriate next step by the physician?

A 6-year-old boy is brought to the emergency department by his parents for increasing abdominal pain. The pain began 3 days ago and has become progressively worse. It is associated with nausea and vomiting. He had some mild watery diarrhea and low-grade fevers starting 1 week ago that resolved without further treatment. Over the past 5 days, his parents note that he has been running to the bathroom more frequently than usual. He has no known medical problems and takes a pediatric multivitamin. He has no prior surgeries. He lives at home with both parents and an older sister and they have a pet cat. The patient's temperature is 98.6°F (37.0°C), 100/64 mmHg, pulse is 122/min, and respirations are 38/min. Physical examination reveals an ill-appearing boy with rapid and deep respirations. Cardiac auscultation reveals a normal S1 and S2 without any murmurs. His oral mucosa is dry and there is no axillary moisture. Laboratory results are shown below: Fingerstick blood glucose: 600 mg/dL Urine beta-hydroxybutyrate: positive Which of the following enzymes is most likely to have increased activity as a result of this patient's condition?

A 71-year-old woman presents to her primary care physician for her yearly physical exam. Since her last visit, she sustained a distal radius fracture from a ground-level fall that has healed without complication. At the time, it was recommended that she undergo a bone density scan and she is interested in the results of that study today. Her past medical history is significant for hypertension but she is not currently taking any medications. Her temperature is 98.6°F (37°C), blood pressure is 152/91 mmHg, pulse is 73/min, and respirations are 13/min. Her blood pressure during her previous visit was also elevated in this range. A physical exam is unrevealing with no murmurs, rubs, or gallops appreciated. Her physician lets her know that the Z-score for her bone mineral density is -2.9. Which of the following medications would be most effective in addressing both her bone mineral density and her elevated blood pressure?

An 81-year-old man with a history of papillary thyroid carcinoma is admitted to the hospital in order to proceed with a surgical thyroidectomy. His past medical history is significant for hypertension, diabetes, and thyroid carcinoma which was diagnosed by fine needle aspiration. His temperature is 98.6°F (37°C), blood pressure is 145/91 mmHg, pulse is 91/min, and respirations are 12/min. Physical exam demonstrates a nodular thyroid gland but no other significant findings. During the process of consent, the risks and benefits of the surgery are discussed. Standard risks of surgery such as infection, bleeding, and damage to surrounding structures are presented. The patient asks about what symptom he would experience if nerve damage was sustained during the surgery. Which of the following would be a result of the most common nerve complication of this surgery?

A scientist is studying the behavior of a novel hormone receptor in humans. The hormone is found to circulate systemically in the bloodstream and results in pleomorphic effects in different organ systems. She isolates cells that express the hormone receptor and uses differential centrifugation techniques in order to fractionate the membranes present in the cell. She finds that the hormone receptor is expressed in both the cytosolic and nuclear fractions of the homogenate but is not present on the plasma membrane or low-density membrane fractions of the homogenate. She uses formaldehyde to crosslink the receptor in the nuclear fraction of the homogenate and found that the receptor is bound to DNA. Which of the following hormones would most likely bind to the receptor described in this case?

A 56-year-old man presents to his primary care physician with a 3-year history of shortness of breath. He says that he cannot identify anything in particular that triggers his symptoms, but his symptoms have been getting worse over time. In the beginning, he had only a dry cough, but now his symptoms include chest pain, fatigue, and difficulty catching his breath after walking down his block. His past medical history is significant for type 2 diabetes, and he has worked as a welder in the aerospace industry for 30 years. Which of the following would most likely be seen on lung biopsy in this patient?