Repeated USMLE Questions Step 1 Review-165- Pharmacology

Q- A patient with heart failure is started on sacubitril/valsartan. What is the primary pharmacologic action of sacubitril? A- Angiotensin II receptor blockade B- Inhibition of neprilysin C- Inhibition of renin release D- Stimulation of natriuretic peptide receptors   Q- A patient taking linezolid develops thrombocytopenia after prolonged therapy. What is the underlying mechanism? A- … Read more

Repeated USMLE Questions Step 1 Review-164- Pathology

Q- A 45-year-old woman presents with episodic headaches, sweating, and palpitations. Imaging reveals an adrenal medullary tumor. Which histologic pattern is most characteristic of this tumor? A- Keratin pearls B- Psammoma bodies C- Sheets of small blue cells D- Zellballen pattern   Q- A 63-year-old man with long-standing diabetes presents with progressive renal failure. Renal … Read more

Repeated USMLE Questions Step 1 Review-163- Pharmacology

Q- A patient taking warfarin is given vitamin K. What is the primary effect of vitamin K administration? A- Decreases synthesis of clotting factors II, VII, IX, X B- Increases synthesis of clotting factors II, VII, IX, X C- Inhibits platelet aggregation D- Prevents fibrin degradation   Q- A patient taking spironolactone develops breast enlargement … Read more

Repeated USMLE Questions Step 1- Review-162

Q- A 2-year-old child has recurrent infections with catalase-positive organisms. Neutrophils show absent oxidative burst on flow cytometry. Which enzyme is defective? A- Adenosine deaminase B- Glucose-6-phosphate dehydrogenase C- NADPH oxidase D- Myeloperoxidase   Q- A patient has difficulty rising from a chair and climbing stairs. Biopsy shows endomysial inflammation and CD8+ T-cell infiltration. Which … Read more

Repeated USMLE Questions Step 1 Review-161- Pharmacology

Q- A patient receiving amphotericin B develops fever, chills, and renal dysfunction. What is the primary mechanism of nephrotoxicity? A- Afferent arteriole vasoconstriction B- Autoimmune tubular injury C- Direct glomerular inflammation D- Inhibition of prostaglandin synthesis A- Afferent arteriole vasoconstriction- Amphotericin B causes dose-dependent nephrotoxicity by constricting the afferent arteriole, reducing renal blood flow and … Read more

Repeated USMLE Questions Step 1- Review-160

Q- A patient with chronic kidney disease develops secondary hyperparathyroidism. Which of the following biochemical changes directly stimulates parathyroid hormone (PTH) secretion in this condition? A- Decreased 1,25-dihydroxyvitamin D levels B- Decreased serum phosphate C- Increased calcium-sensing receptor activation D- Increased intestinal calcium absorption   Q- A mutation prevents phosphorylation of the regulatory light chain … Read more