Free Questions and Answers for All Medical Students all over the World
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
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
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
Q- A patient taking allopurinol for gout should be closely monitored for which serious adverse effect? A- Aplastic anemia B- Hepatotoxicity C- Severe hypersensitivity reaction D- Thrombocytopenia Q- A patient with asthma is prescribed propranolol and develops worsening shortness of breath. What explains this effect? A- Alpha-1 receptor blockade B- Beta-1 receptor stimulation C- … Read more
Q- A 59-year-old man presents with progressive dysphagia. Endoscopy reveals an ulcerated mass in the distal esophagus. Biopsy shows malignant gland-forming cells. Which risk factor is most strongly associated with this condition? A- Alcohol consumption B- Chronic gastroesophageal reflux disease C- Human papillomavirus infection D- Iron deficiency anemia Q- A 66-year-old woman presents with … Read more
Q- A patient treated with cisplatin develops hearing loss. What is the mechanism of this adverse effect? A- Accumulation in cochlear hair cells B- Autoimmune inner ear inflammation C- Decreased cerebral perfusion D- Inhibition of prostaglandin synthesis Q- A patient taking phenelzine develops severe hypertension after eating aged cheese. What is the underlying cause … Read more