A 12-year-old girl visits her physician for follow up after treatment with methotrexate for acute lymphoblastic leukemia. Stool analysis reveals blood in stool. Her platelet count is very low. Which of these substances should be administered immediately? A-Vitamin K B-Leucovorin C-Deferoxamine D-Amitriptyline E-Penicillamine Answer This is a case of methotrexate toxicity. Leucovorin is the active […]
USMLE Step 1
Repeated USMLE Questions Step 1- 265
As physicians, we need to know some definitions in Genetics, which are related directly to our practice and guide us to diagnose and treat many genetic disorders. These items include genome, genotype, phenotype, genetic code, gene expression, etc. Which one of the following choices describes the definition of a phenotype? A- Genetic constitution of an […]
Repeated USMLE Questions Step 1- 264
A 43-year-old man presents to your clinic for a follow up after colon biopsy taken last week. He has a history of constipation and blood in stools for 6 months. Biopsy reveals colon cancer. After you told him the bad news, he looked down and told you that constipation was not that bad. He seeks […]
Repeated USMLE Questions Step 1- 263
A 48-year old man presents to the emergency room with severe headache and blurred vision. His blood pressure is 230/140. Ophthalmologic examination reveals blurred optic discs with indistinct margins. An intravenous drip of nitroprusside is started. What is the mechanism of action of this medication? A- Alpha adrenergic antagonist B- Beta adrenergic antagonist C- Ganglion […]
Repeated USMLE Questions Step 1- 262
A 73-year-old man with a history of benign prostatic hyperplasia (BPH) presents to the emergency room complaining of repeated falls. His wife admits that during the past 3 weeks he has had unsteady gait, urinary incontinence and memory disturbances. His medical, surgical and family histories are unremarkable. He has never smoked or taken any recreational […]
Repeated USMLE Questions Step 1- 261
A 43-year old cashier visits her physician with a complaint of severe pain for 3 months and a new onset of itching in her right leg. Examination reveals multiple varicosities on the medial side the right thigh and leg and an erythematous patch on the medial side of the knee. What is the most common […]