USMLE

Which of the following characteristics most strongly suggests that the cell depicted above is a phagocytically active macrophage?

A 3-year-old male presents with a skin rash and epistaxis. He has had several, severe sinopulmonary infections. A careful history reveals that his maternal grandfather died of bleeding complications following an emergency cholecystectomy. What additional findings are likely in this case?

A 24-year-old woman presents with a 3-day history of fever, chills, chest pain, and cough productive of rust-colored sputum. Past medical history includes a splenectomy 1 year ago. A chest x-ray film indicates consolidation of the right lower lobe. Blood cultures are positive for a-hemolytic gram-positive diplococci. Immunity to the causative organism is based on

A 25-year-old female presents with a confluent maculopapular rash that began on her face, then spread downward over her trunk. She states that 3 days ago she started having a fever and headache, with bilateral pain associated with the front and back of her neck. She also complains of joint pain. Which of the following diseases does she most likely have?

A 73-year-old woman with a history of diabetes presents with left ear pain and drainage of pus from the ear canal. She has swelling and tenderness over the left mastoid bone. Which of the following microorganisms is the most likely causative agent?

Which of the following organisms is most likely to be implicated as a cause of urethritis that persists after antibiotic therapy for gonorrhea?

A 4-year-old boy is seen by his pediatrician for epistaxis. The patient has a history of multiple bacterial and viral respiratory tract infections and eczema. An uncle had similar problems. Physical examination is remarkable for multiple petechial lesions on the skin and mucous membranes. Serum IgE is increased, and platelets are decreased. Which of the following is the most likely diagnosis?

A 54-year-old woman suffering from influenza deteriorates and develops shaking chills and a high fever. Physical examination is remarkable for dullness to percussion at the left base and decreased breath sounds on the left. Chest x-ray confirms the diagnosis of lobar pneumonia, presumed to be caused by Streptococcus pneumoniae. The patient has no known drug allergies. Which of the following antibiotics would be most appropriate to treat the patient's condition?

A 27-year-old woman presents to the emergency department complaining of 10-12 episodes of nonbloody diarrhea per day for the past 2 days, along with severe abdominal cramps, nausea, vomiting, and a low-grade fever. She states that she just returned from a vacation to Mexico. While in Mexico, she did not drink any of the local water and ate only cooked foods and a few fresh salads. If fecal leukocytes are present, the patient should most likely be empirically treated with

A patient with a cavitary lung lesion coughs up sputum that contains thin, acid-fast positive rods. Which of the following features would most likely be associated with these bacteria?