USMLE Step 1 Questions with Complete Solutions 2023-Graded A+

USMLE Step 1 Questions with Complete Solutions 2023-Graded A+ Heterophile ab NEGATIVE Mono-like syndromes - CORRECT ANSWER *CMV HHV-6 HIV Toxoplasmosis Wernicke's Aphasia - CORRECT ANSWER -word salad: well-articulated, nonsensical speech paired with lack of lang comprehension -aud association cortex: post part of sup temporal gyrus - supplied by MCA Congenital Deficiency of Propionyl CoA Carboxylase - CORRECT ANSWER -prevents conversion of propionyl CoA to methylmalonyl CoA -propionyl CoA derived from= val, ile, met, thr, odd # FA, cholesterol side chains -Propionic Acidemia: poor feeding, vomiting, hypotonia, lethargy, dehydration, anion gap acidosis Down Synd Comorbidities - CORRECT ANSWER Neuro: MR, early onset Alzheimer's Cardio: complete AV septal defect, VSD, ASD GI: duodenal atresia, hirschprung disease Endo: hypothyroid, DM1, obesity Heme: ALL (> 5 yo) and AML (<5 yo) Rheumatology: atlantoaxial stability MCC of Hypoglycemia in EtOH-ics - CORRECT ANSWER Thiamine def= suppression of GNG (pyruvate DH) and TCA cyle (alpha-KG DH) MCC of Hypoglycemia in advanced renal insuff - CORRECT ANSWER impaired clearance of insulin Avoid Nitrates in Hypertrophic Cardiomyopathy bc... - CORRECT ANSWER Nitrates decrease preload, which will increase the LV outflow tract... BUT since the ventricle is abnormally shaped, there is an outflow obstruction Mets through BM - CORRECT ANSWER Clonal proliferation of cells can invade/ metastasize* 1. malignant cells to lose their cell-to-cell adhesion molecules (cadherins) 2. cell receptors to attach to laminin (a glycoprotein) in the basement membrane and to release metalloproteinases (e.g., collagenases, stromelysins, gelatinases) to degrade the basement membrane and other enzymes to degrade the interstitial connective tissue- tissue inhibitors of metalloproteinases neutralize these tumor-produced enzymes and limit the degree of invasion