A 55-year-old woman is diagnosed with metastatic breast cancer. The patient is treated with an opioid analgesic for bone pain that is well controlled during the first week of therapy. The following week, the analgesic dose becomes ineffective and the patient reports nausea, itching, and constipation. She has become very weak and is unable to walk due to the pain.

The opioid dose is increased. The patient is concerned about side effects with higher dosages, noting that her son has a history of opioid dependence, and "I watched him suffer a lot of bad reactions”. The physician explains the concept of tolerance to opioids and that high doses are commonly required to control pain.

Over the next few weeks, the patient would likely experience which of the following?

A 65-year-old man comes to the emergency department due to an episode of hemoptysis that occurred earlier this morning. The patient estimates that he coughed up about 100 mL of blood. Prior to this episode he was in his usual state of health and felt well, with no fevers, night sweats, or weight loss. He has had occasional episodes of blood-tinged sputum over the past few months. The patient's past medical history is significant for tuberculosis (TB) that was effectively treated several years ago. He had smoked a pack of cigarettes daily for 45 years but quit 4 years ago.

A representative cut of the CT scan, demonstrates changes consistent with prior TB infection, including an old left upper lobe cavity. Compared to prior scans, the main difference is that the cavity now appears to be filled with a round mass.

Which of the following best describes this patient's condition?

A 56-year old man hospitalized in the intensive care unit is being evaluated for fever. He was admitted 8 days ago with respiratory failure and has had a complicated hospital course, including mechanical ventilation, central venous line placement, and broad-spectrum antibiotic therapy. The patient has a history of HIV and a hematologic malignancy. His last chemotherapy session was 2 weeks ago.

Chest x-ray does not reveal a new infiltrate, and urine cultures are negative for infection. Blood cultures grow pseudohyphae-producing yeast species with an ability to form germ tubes.

Which of the following most likely directly contributed to the development of fungemia in this patient?

A 34-year-old Asian female is hospitalized with progressive exertional dyspnea, lower extremity edema and cough. She also describes frequent nocturnal episodes of breathlessness and recent hoarseness. She does not use tobacco, alcohol or drugs. Auscultation reveals loud first and second heart sounds and a mid-diastolic rumble best heard at the cardiac apex.

This patient's hoarseness is most likely caused by

A 64-year-old man is brought to the emergency department due to worsening shortness of breath. The patient is able to speak in short sentences only and becomes hypoxemic with minimal exertion. His medical history includes hypertension and dyslipidemia. He smoked a pack of cigarettes a day for 40 years and worked for 25 years as a nickel miner. His father died of chronic respiratory failure.

While in the emergency department, he rapidly develops respiratory failure and is intubated. Despite appropriate treatment, he dies several days later in the intensive care unit. Autopsy is performed, and examination or the bronchi reveals thickened bronchial walls, inflammatory infiltrates, mucous gland enlargement, and patchy squamous metaplasia of the bronchial mucosa.

Which of the following factors was likely the greatest contributor to this patient’s pathological findings?

A 46-year-old man is brought to the emergency department 30 minutes after being found intoxicated in a park. The patient reports a 10-day history of fevers, night sweats, weight loss, and productive cough with foul-smelling sputum. He drinks 1 or 2 pints of vodka daily and has been hospitalized multiple times tor intoxication.

Temperature is 38.9^oC, blood pressure is 110/65 mm Hg. pulse is 102/min, and respirations are 22/min. Lung auscultation reveals coarse crackles over the right lower lobe. Heart sounds are normal with no murmurs. Laboratory results show an elevated leukocyte count. Chest x-ray reveals a cavitary lesion with an air-fluid level in the superior segment of the right lower lobe of the lung.

Which of the following is the most likely cause of this patient’s lung findings?

A 64-year-old woman comes to the hospital due to sudden-onset right arm weakness and difficulty speaking, which completely resolved within 20 minutes. The patient has had no shaking movements, headache, nausea, photophobia, or anxiety. She has a history of hypertension and hypercholesterolemia and takes amlodipine and rosuvastatin, respectively.

Her blood pressure is 125/70 mm Hg and pulse is 78/min and regular. Neurologic examination is unremarkable. Fingerstick glucose is within normal limits. ECG shows normal sinus rhythm. Carotid Doppler reveals mild left common carotid artery stenosis. MRI of the brain and echocardiogram are unremarkable.

If the patient is started on an additional medication that is indicated for her condition, which of the following adverse effects is most likely to occur?

A 67-year-old man comes to the emergency department with low-grade fevers and fatigue. He has no history of heart disease. His temperature is 38.4^oC, blood pressure is 117/76 mm Hg. Pulse is 82/min, and respirations are 14/min.

On examination, there is a diastolic murmur at the left sternal border. He has nontender erythematous macules on his hands and feet. Blood cultures show gram-positive cocci that are catalase-negative and able to grow in hypertonic (6.5%) saline and bile.

This patient's medical history is most likely to include which of the following procedures within the past month?

A 28-year-old man comes to the office with a 2-month history of dull low back pain and morning stiffness. The pain had an insidious onset, and the patient does not recall any recent trauma. He attempted treatment with acetaminophen and spinal manipulation, which did not provide relief. The patient has usually slept on his back but now must lie on his side to fall asleep easily. Past medical history is unremarkable. Vital signs are normal.

Physical examination shows limited anterior flexion of the spine. There is no swelling or warmth of any peripheral joints. X-rays reveal narrowing of the sacroiliac joints. Rheumatoid factor assay was negative.

Which of the following Is most strongly associated with this patient s disease?

A 45-year-old man comes to the emergency department because of severe chest pain, diaphoresis, and palpitations. The patient dies two hours after the onset of his symptoms. Autopsy reveals 100% occlusion of the left anterior descending artery.

At the time of the patient’s death, light microscopy of the affected myocardium would most likely demonstrate which of the following'?

A 54-year-old man with a history of hepatitis C infection is brought to the emergency department by his wife after several episodes of vomiting bright red blood. He is admitted to the hospital and the appropriate treatment is initiated. During morning rounds the next day, the patient is disoriented and cannot identify the month or his current location.

Physical examination shows significant abdominal distention and gynecomastia. Repetitive ticking motions of the hands are seen when the patient is asked to outstretch his arms and dorsiflex his wrists.

Which of the following is most likely contributing to this patient’s altered mental status?

A 66-year-old man comes to the office for hypertension follow-up. The patient takes lisinopril and amlodipine, but his blood pressure recordings have been 140-150/85-95 mm Hg over the past 2 office visits. He has had no chest pain or shortness of breath. The patient also reports worsening urinary symptoms over the past year that include hesitancy, straining during urination, poor urinary flow, and waking up once or twice a night to urinate. He feels the symptoms are bothersome but are not affecting his quality of life.

The patient has no other medical conditions and does not use tobacco, alcohol, or illicit drugs. Blood pressure is 142/88 mm Hg and pulse is 70/min. Physical examination shows a mildly enlarged, smooth prostate but is otherwise unremarkable. Serum chemistry studies and urinalysis are normal.

Which of the following medications would be most effective for treating this patient's medical issues?

A 56-year-old man comes to the emergency department due to progressively worsening dyspnea. The patient can walk only a few blocks before becoming short of breath. He also finds it difficult to sleep lying flat and requires 3 pillows to prop himself upright when sleeping. Other medical problems include long-standing hypertension, for which he occasionally takes his prescribed anti-hypertensive medication. The patient does not use tobacco, alcohol, or illicit drugs.

Blood pressure is 170/100 mm Hg, and pulse is 80/min and regular. Physical examination reveals bilateral basilar lung crackles, Jugular venous distension, and bilateral lower extremity edema. Chest x-ray reveals cardiomegaly and hilar prominence. ECG shows left ventricular hypertrophy. Echocardiogram shows elevated pressures in the pulmonary artery.

Which of the following is the most likely underlying cause of the observed echocardiographic finding in this patient?

A 42-year old man with a long history of type 1 diabetes mellitus comes to the office due to frequent involuntary loss of urine. For the past several months, he has been having difficulty starting and maintaining a urinary stream. In the last 3 weeks, he has had 2 episodes of nocturnal enuresis and multiple daytime episodes of uncontrolled voiding without any sensation of a full bladder. His other medical problems include chronic kidney disease and gastroparesis. He does not use tobacco or alcohol.

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

A group of researchers collected demographic and clinical data from multiple hospitals across the nation to determine epidemiological features of nosocomial bloodstream infections. In this study, a nosocomial bloodstream infection was diagnosed if blood cultures drawn 48 hours after admission yielded a pathogenic organism. Analysis of the data collected over several decades shows that staphylococci are increasingly responsible for the identified cases.

An increased use of which of the following is most likely the underlying cause of the observed trend?

The autopsy of a 78-year-old Caucasian male who died of esophageal cancer reveals a small heart without significant coronary artery atherosclerosis. Myocardial cells show prominent intracytoplasmic granules that are tinged yellowish- brown.

Which of the following most likely accounts for the observed microscopic changes?

A 45-year-old woman is hospitalized due to severe Pneumocystis pneumonia. The patient has a history of injection drug use and was diagnosed with HIV 10 years ago. She does not adhere to antiretroviral therapy and has developed resistance to multiple antiretroviral medications. Laboratory evaluation reveals severe immunosuppression with a high HIV viral load.

After the patient is adequately treated for pneumonia, HIV genotypic analysis is performed. The viral isolates are found to have a mutation in the variable (v3) region of the env gene, which makes the virus capable of infecting T-cells with a specific surface receptor, but infection of macrophages is inefficient.

Which of the following antiretroviral medications is most likely to be ineffective in this patient?

A 78-year-old man with severe dementia is brought to the emergency department due to a day-long history of lethargy, fever, and vomiting. The patient lives in a nursing home, and his caregivers report that he has had poor oral intake over the last week. Medical history is significant for emphysema, heart failure with reduced ejection traction, hypertension, and diabetes mellitus type 2.

On physical examination, the patient is lethargic but arousable. Blood pressure is 60/30 mmHg and pulse is 120/min and regular. The extremities are warm. Coarse rhonchi are heard over the right lower Lung. After receiving several intravenous fluid boluses, the patient is given an intravenous infusion of an agent that increases peripheral vascular resistance, increases blood pressure, and decreases heart rate.

Which of the following agents is most likely being described?

A 16-year-old girl comes to the office due to pelvic and crampy lower abdominal pain that seems to recur at the beginning of each month and resolves after a day or two. She thinks the pain began approximately 6 months ago, and it is worsening significantly each month. The patient has never had a menstrual period. She and her boyfriend have not had any form of sexual intercourse, including digital, oral, vaginal, or anal.

The patient’s weight, height, and BMI are average for age and sex, and she has fully developed secondary sexual characteristics. Examination reveals a palpable mass anterior to the rectum. Serum Beta-hCG is negative.

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

A 28-year-old woman comes to the office due to progressively worsening eye irritation and double vision over the last 2 months. She also reports unintentional weight loss, mood swings, and palpitations. The patient has no prior medical problems and takes no medications. She has no known drug allergies and does not use tobacco, alcohol, or illicit drugs. Blood pressure is 140/70 mmHg, and pulse is 110/min and regular.

Physical examination shows bilateral conjunctival redness and severe proptosis. Appropriate therapy is begun. On a follow-up visit 4 weeks later, her eye symptoms have improved, and examination reveals a small decrease in proptosis with no redness.

The drug that improved her ocular symptoms most likely did so by affecting which of the following?

A 6-year-old boy playing in a dusty field in windy weather inhales many small particles that become lodged in his terminal bronchioles. Which of the following respiratory components is most important in clearing these particles?

A 44-year-old man comes to the clinic due to increasing fatigue, trouble sleeping, and palpitations. He has lost 9 kg over the last year despite eating well. The patient says he is under a lot of pressure at work but cannot think of any other precipitating factors for his insomnia. He has no other medical problems and takes no medications. The patient does not use tobacco, alcohol, or illicit drugs. His mother has a history of a thyroid problem. Blood pressure is 140/80 mm Hg and pulse is 108/min.

On physical examination, the thyroid is diffusely enlarged. His serum free thyroxine levels are elevated and TSH level is decreased. He is found to have a positive assay for thyrotropin receptor antibodies.

If present, which of the following additional findings would be most specific to the underlying cause of this patient’s hyperthyroidism?

A 22-year-old man comes to the office for evaluation of a neck mass. He first noticed a small nodule in his lower neck 6 months ago, and it has progressively enlarged since that time. The patient has had no changes in weight and otherwise feels well. Medical history is notable only for seasonal allergies, and he takes no medications.

Physical examination shows a 2-cm nodule in the right lobe of the thyroid. There are multiple 4 to 8-mm soft papules on the lips and tongue. The arm span exceeds his height and the patient has long fingers. Serum calcitonin levels are elevated.

Which of the following is most likely to develop in this patient?

A 7-year-old boy is brought to the emergency department by his parents for abdominal pain and arthralgias. He had a cough and runny nose last week but otherwise has been in good health. The patient's temperature is 37^oC, pulse is 92/min, and respirations are 20/min. Physical examination shows palpable purpura over his buttocks and thighs. Auscultation of the lungs and heart is normal. His abdomen is diffusely tender to palpation without rebound or guarding. Both knees are tender but do not appear warm or swollen. A stool occult blood test is positive. Urinalysis results are as follows:

Protein: 2+

Blood: moderate

Leukocyte esterase: trace

Nitrites: negative

White blood cells: 1-2/hpt

Red blood cells (RBCs): many/hpf

Casts: RBC casts

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