USMLE Step 1 - uWorld High Yield Notes Rated A

USMLE Step 1 - uWorld High Yield Notes Rated A What are the two major microtubular motor proteins? Which does anterograde axonal transport, which does retrograde axonal transport? Kinesin, Dynein Kinesin: Anterograde Dynein: Retrograde` What do you think, immunologically speaking, when you see someone with recurrent Neisseria infections? Inability to form the membrane attack (MAC) complex this is a common complement deficiency What is the defect in Chronic Granulomatous disease? What is the pathophysiology? NADPH Oxidase deficiency leads to the inability to kill intracellular organisms Characteristic triad of ataxia telangiectasia? cerebellar ataxia, telangiectasias, increased risk of sinopulmonary infections What is the major immune deficiency of ataxia telangiectasia? IgA deficiency, which predisposes to infections of the upper and lower airways (and other mucous membranes) There's a useful mnemonic for Ataxia Telangiectasia and the gene that's mutated. What is it? ATM Ataxia Telangiectasia Mutated ATM gene is responsible for DNA break repair What is one reason that lead intoxication causes hypochromic anemia? Mitochondrial iron transport is important for Heme synthesis! It's inhibited by lead. So you don't make heme in your mitochondria and you get hypochromic anemia. What is the biochemical problem in Lesch-Nyhan syndrome? (And, only if you got that right, what are the really cool symptoms of it?) Defective purine catabolism, so buildup of purines. It's an X-linked recessive disorder with mutated HGPRT gene (hypoxanthine-guanine phosphoribosyltransferase, if you want to impress people). Now, if you got HGPRT and purine catabolism right, you can say: self-mutilating behavior on top of mental retardation, choreoathetoid (think Chorea) movements and spasticity. What is the defect in Niemann-Pick disease? What causes that? What is the common macular finding? Sphingolipid degradation is defective Caused by an autosomal recessive defect in sphingomyelinase Cherry Spot on the macula? Niemann Pick's or Tay Sach's. If a baby gets exposed to an unclean knife (...) and subsequently develops rigid paralysis, what is the diagnosis, where do we think this might happen, and how do we prevent it? Neonatal Tetanus Developing Countries Maternal immunization with tetanus toxoid is the best way to prevent it an adeuately immunized mom will transfer IgG's across the placenta to the neonate Which microtubule associated protein aids in anterograde transport of intracellular vesicles and organelles? Which end of the microtubule do they go towards? Kinesin. Towards the (+) rapidly growing end. What is an early BRAIN finding of Ataxia-Telangiectasia and how does it manifest itself? Cerebellar atrophy manifests as ataxia in the first years of life. High yield path association for Alzheimer's disease? Neurofibrillary tangles in the neocortex High yield path association for Parkinson's disease? Loss of neurons in the substantia nigra High yield path association for Huntington disease? Atrophy of caudate nucleus What are the major manifestations of Ataxia-telangiectasia? cerebellar ataxia, oculocutaneous tenlangiectasias, repeated sinopulmonary infections, and an increased incidence of malignancy If you heard: amenorrhea, bitemporal hemianopsia, and enlargement of the pituitary gland on brain imaging, what would you be thinking? Prolactinoma, the most common pituitary adenoma. What embryological layer is the anterior pituitary derived from? Surface ectoderm What is the most common congenital abnormality associated with the use of Sodium Valproate during pregnancy? neural tube defects, e.g., meningocele because valproate inhibits intestinal folic acid absorption resulting in teratogenicity What is the characteristic histology of a craniopharyngioma? On light microscopy, cysts are lined by stratified squamous epithelium, possibly with Keratin perals. Cysts are usually filled iwth a yellow, viscous fluid that's rich in cholesterol crystals. Where do craniopharyngyomas arise from? Craniopharyngiomas are calcified cystic tumors that arise from remnants of Rathke's pouch (embryonic precuros of the anterior pituitary) Failure of what process leads due neural tube defects? What can be seen in the amniotic fluid due to leakage of fetal cebebrospinal fluid? Failure of fusion of the neuropores. Alpha-fetoprotein and Acetylcholinesterase may appear in the amniotic fluid Can a competent patient refuse healthcare? Can a competent patient refuse knowledge of their potential health situation? yes and yes What is the consensus and professional standard regarding the receiving of gifts from patients? Don't do it. It's unethical to accept individual gifts from patients, especially of signficant value. AMA doesn't have clear cut answer, but they recommend careful consideration be used. some general