Eicosanoid synthesis and function — MCQs

A 6-year-old boy is presented to a pediatric clinic by his mother with complaints of fever, malaise, and cough for the past 2 days. He frequently complains of a sore throat and has difficulty eating solid foods. The mother mentions that, initially, the boy’s fever was low-grade and intermittent but later became high grade and continuous. The boy was born at 39 weeks gestation via spontaneous vaginal delivery. He is up to date on all vaccines and is meeting all developmental milestones. The past medical history is noncontributory. The boy takes a multivitamin every day. The mother reports that he does well in school and is helpful around the house. The boy’s vital signs include blood pressure 110/65 mm Hg, heart rate 110/min, respiratory rate 32/min, and temperature 38.3°C (101.0°F). On physical examination, the boy appears uncomfortable and has difficulty breathing. His heart is mildly tachycardic with a regular rhythm and his lungs are clear to auscultation bilaterally. Oropharyngeal examination shows that his palatine tonsils are covered with pus and that there is erythema of the surrounding mucosa. Which of the following mediators is responsible for this patient’s elevated temperature?

A 53-year-old man is brought to the emergency department because of wheezing and shortness of breath that began 1 hour after he took a new medication. Earlier in the day he was diagnosed with stable angina pectoris and prescribed a drug that irreversibly inhibits cyclooxygenase-1 and 2. He has chronic rhinosinusitis and asthma treated with inhaled β-adrenergic agonists and corticosteroids. His respirations are 26/min. Examination shows multiple small, erythematous nasal mucosal lesions. After the patient is stabilized, therapy for primary prevention of coronary artery disease should be switched to a drug with which of the following mechanisms of action?

A 14-year-old boy is brought to the emergency department because of a 4-hour history of vomiting, lethargy, and confusion. Three days ago, he was treated with an over-the-counter medication for fever and runny nose. He is oriented only to person. His blood pressure is 100/70 mm Hg. Examination shows bilateral optic disc swelling and hepatomegaly. His blood glucose concentration is 65 mg/dL. Toxicology screening for serum acetaminophen is negative. The over-the-counter medication that was most likely used by this patient has which of the following additional effects?

A 54-year-old man comes to the physician for a follow-up examination. One week ago, he was treated in the emergency department for chest pain, palpitations, and dyspnea. As part of his regimen, he was started on a medication that irreversibly inhibits the synthesis of thromboxane A2 and prostaglandins. Which of the following is the most likely adverse effect of this medication?

A 61-year-old woman comes to the physician because of a 6-month history of left knee pain and stiffness. Examination of the left knee shows tenderness to palpation along the joint line; there is crepitus with full flexion and extension. An x-ray of the knee shows osteophytes with joint-space narrowing. Arthrocentesis of the knee joint yields clear fluid with a leukocyte count of 120/mm3. Treatment with ibuprofen during the next week significantly improves her condition. The beneficial effect of this drug is most likely due to inhibition of which of the following?

A 48-year-old woman presents to the emergency room because of severe back pain after a fall. She says that she was walking home from work when she slipped on a patch of ice on the sidewalk. Since she did not have anything to hold onto, she fell backwards and landed on her posterior iliac crests bilaterally. Immediately after the fall, she started experiencing back pain and tenderness that concerned her enough to call for an ambulance. Her past medical history is significant for arthritis, diabetes, and hypertension. On arrival, her temperature is 99°F (37.2°C), blood pressure is 129/86 mmHg, pulse is 112/min, respirations are 19/min. Physical exam reveals tenderness to palpation over the middle of her lower back. A drug that may have predisposed this patient to this outcome most likely has which of the following mechanisms?

A 19-year-old woman with a history of poorly controlled asthma presents to her pulmonologist for a follow-up visit. She was recently hospitalized for an asthma exacerbation. It is her third hospitalization in the past five years. She currently takes inhaled salmeterol and medium-dose inhaled budesonide. Her past medical history is also notable for psoriasis. She does not smoke and does not drink alcohol. Her temperature is 98.6°F (37°C), blood pressure is 110/65 mmHg, pulse is 75/min, and respirations are 20/min. Physical examination reveals bilateral wheezes that are loudest at the bases. The patient’s physician decides to start the patient on zileuton. Which of the following is the most immediate downstream effect of initiating zileuton?

A 59-year-old male with a 1-year history of bilateral knee arthritis presents with epigastric pain that intensifies with meals. He has been self-medicating with aspirin, taking up to 2,000 mg per day for the past six months. Which of the following medications, if taken instead of aspirin, could have minimized his risk of experiencing this epigastric pain?

A researcher is studying how arachidonic acid metabolites mediate the inflammatory response in rats. She has developed multiple enzyme inhibitors that specifically target individual proteins in the arachidonic acid pathway. She injects these inhibitors in rats who have been exposed to common bacterial pathogens and analyzes their downstream effects. In one of her experiments, she injects a leukotriene B4 inhibitor into a rat and observes an abnormal cell response. Which of the following interleukins would most closely restore the function of one of the missing products?

A 42-year-old woman comes to her primary care physician because of an irritating sensation in her nose. She noticed recently that there seems to be a lump in her nose. Her past medical history is significant for pain that seems to migrate around her body and is refractory to treatment. She has intermittently been taking a medication for the pain and recently increased the dose of the drug. Which of the following processes was most likely responsible for development of this patient's complaint?