NBME 30

NBME 30 56 y/o F comes to physician 3 wk hx increasing weakness of arms and legs. - Smoking - Weakness of hip girdle muscles, lesser weakness of shoulder girdle muscles. - Weakness improves with repetitive testing. - Hilar lung mass What's impaired: - Acetylocholinesterase - Binding of ACh on postsynaptic membrane - Direct depolarization of muscle by Ca - Postsynaptic membrane potential - Presynaptic release of ACh -- Presynaptic release of ACh - Lambert Eaton myasthenic syndrome (ab to voltage-gated calcium channels on presynaptic LMNs, which decreased calcium influx and ACh release to postsynaptic SkM cells 23 y/o F 1 wk history of intermittent fever, chills, rash - Hx 4 operations (1) scoliosis, (2) tonsillectomy, (3) appendectomy, (4) lipoma. - Hx admission for N/V - Dermabrasion to correct acne scarring - PE: 12 evenly spaced punctate marks in linear patten on abdomen and UE, LE Diagnosis? - AML - Factitious d/o - ITP - Lyme disease - Syphilis -- Factitious disorder - patients produced symptoms for primary gain. Primary gain is motivation to be cared for, which constitutes unconscious motivator in patients production of symptoms. "Care seeking" tx - regular f/u with one physician who oversees management & psychotherapy An investigator is studying the adverse effects of a proteasome inhibitor, bortezomib, on immune responses. Administered to group of pts with relapsed MM and immune response observed. Which immunologic processes affected by drug? - Activation of complement cascade - Activation of perforin - Presentation of antigens to CD8+ T lymphocytes - Secretion of histamine by mast cells - Secretion of IL-1 by macrophages -- Presentation of antigens to CD8+ T lymphocytes - Proteasomes ar elarge proteases with numerous domains that ar epresent in cytoplasm adn nuceli. Made of alpha nd beta subunits and have extensive role in cell cycle regulations and immune function. Caspase, chymotrypsin, and trypsin-like protease capabilities of this enzyme complex are critical to their role as APC; intracellular peptides are processed in teh proteasomme for presentation on Class I MHC. Which are regogized by CD8 T lympocytes. 12 y/o girl sliced her left palm with a knife. Would is cleaned and suture. One week later, sutures are removed. At this time, which of the following factors is most instrumental in migration fo fibroblasts into area of would healing? - collagen - fibronectin - heparin - IG - plasminogen -- Fibronectin. Collagen is then synthesized by the fibroblasts. What is the most common brain tumor in adults? -- M