UWorld test 1 Flashcards
adenomyosis
presence of endometrial tissue and stroma within the uterine myometrium
Radiographic findings of osteosarcoma
destruction of normal trabecular bone pattern, mixed radiodense and radiolucent areas, periosteal new bone formation, lifting of the cortex, and Codman’s triangle. soft tissue adjacent to the osteosarcoma demonstrates ossification in a “sunburst” pattern.
osteoarthritis is different b/c it will show improvement with OTC analgesics and osteophytes and joint space narrowing on X-ray.
What are the important translocations for leukemias?
9;22: chronic myelogenous leukemia
15;17: M3 type of acute myeloid leukemia (Auer rods). treat with ATRA. Not all AML has this translocation.
follicular lymphoma: t14;18. bcl-2 activation
mantle lymphoma: 11;14. cyclin D activation
burkitt lymphoma: 8;11. c-myc activation
What are the cytokines secreted by macrophages? By T cells?
macrophages: IL1, 6, 8,12, TNF-alpha all T cells: IL 2, 3 Th1 T cells: IFN-gamma Th2 T cells: IL4, IL5, IL10 IFN alpha and beta are made by virally infected cells
desmosomes vs. hemidesmosomes; cadherins
desmosomes attach cells to cells; hemidesmosomes attach cells to the basement membrane and to integrins.
cadherins are calcium dependent adhesion molecules that help muscle and epithelial cells bind together. Examples: desmocollins, desmogleins, and E-cadherin.
secretin
delivery of acidic chyme to the duodenum triggers gallbladder bile release and stimulates the S cells to release secretin to the systemic circulation. pancreas is then prompted to generate bicarb-rich fluid which neutralizaes the H ions in carb.
vasculature and knee dislocations
worry about popliteal artery injury in all pts with knee dislocation (as well as tibial nerve and common peroneal nerve). in posterior and anterior disolcations, the popliteal artery is especially at risk bc it is located deep within the popliteal fossa, close to the articular surfaces of the joint, and is tightly fixed. highly susceptible to tearing by traction forces.
endometritis
example: woman has lower abd. pain 2 days after vaginal delivery. temp is 100F, bp 110/70, pulse is 110, resp 18. Bimanual exam reveals tender uterus and foul-smelling vaginal discharge.
endometritis: inflammation of the endometrium with plasma cells and lymphocytes associated with retained products of conception from delivery (any type), or from an IUD. bacteroides is most common cause.
tx: gentamicin + clindamycin +/- ampicillin
What do intracellular tyrosine kinase receptors normally do? examples?
receptors for insulin, IGF-1, FGF, PDGF, EGF, VEGF.
tyrosine kinase receptors are transmembrane proteins with a ligand binding extracellular domain and in intracellular domain with inducible tyrosine kinase activity. ligand binding causes dimerization of 2 identical receptor subunits, which phosphorylate each other. this exposes their catalytic domains.
this is different from receptor associated tyrosine kinases (for prolactin, immunomodulators, and GH, because the intrinsic tyrosine kinases have TK activiy WITHIN them. the receptor associated tyrosine kinases are just receptors. when they bind ligand, the receptors dimerize, which RECRUITS a tyrosine kinase (JAK). JAK is not normally part of the receptor.
What are the effects of heminephrectomy on GFR?
immediately after surgery, GFR is down to 50% of baseline. Within 1 week, the remaining kidney has already increased to 60-70%, and by 6 weeks you are up to 80% of the baseline value.
serratus anterior
innervated by the long thoracic nerve. axillary lymph node dissection (for breast CA) or knife wounds to the axillary area can injure the long thoracic nerve. long thoracic nerve is derived from C5 through C7. serratus anterior originates from the lateral part of the first 8 ribs and inserts on the medial border of the scapula to fix the medial scapula to the chest wall. it also rotates the scaupla. paralysis of this muscle results in an inability to raise the arm over the head and winging of the medial scapula when the outstretched arm is pushed forward against resistance.
what is pancreatic bicarb fluid secretion like? What other tissues do this?
tissues that produce a bicarb rich fluid in response to stimulation: exocrine pancreas and the epithelial cells of the biliary tract. bicarb secretion in these tissues is mediated by secrete (released by S cells in response to acid in the duodenum). the pancreas makes HCO3- rich fluid. this occurs via the exchange of Cl and HCO3, so Cl decreases while HCO3- increases
What are unique features of herpes encephalitis?
olfactory hallucinations or anosomia, temopral lob seizures, personality change, bizarre or psychotic behavior, delirium, aphasia, and/or hemiparesis
(also the normal stuff: fever, headache, seizure, coma).
Porphyrias (REALLY?!!? You already studied these so hard!!!)
Start with the process
glycine and succinyl CoA become ALA (aminolevulinic acid). enzyme is rate limiting and called aminolevulinic acid sythase (ALAS). This step happens in the mitochondria and is decreased by glucose and heme. Problems here cause sideroblastic anemia (decr. heme because decr. protoporphyrin).
ALA is converted to porphobilinogen by ALAD. This step is blocked during lead poisoning.
porphobilinogen –> hydroxymethylbilane by PORPHOBILINOGEN DEAMINASE. a problem with this enzyme will cause acute intermittent porphyria (painful abdomen, port-wine urine, polyneuropathy, psychological disturbances, precipitated by drugs, starvation, alcohol). porphobilinogen and ALA build up in blood. coporphobilinogen builds up in urine.
–> uroporphyrinogen III –> coproporhyrinogen III by uroporphyrinogen decarboxylase. A problem here causes porphyria cutanea tarda (bulla with photo exposure). uroporphyrin builds up- tea colored urine.
finally, back in the mitochondria, propoporphyrin (made from coproporphyrinogen III) joins iron to make heme. this step is done by ferrochelatase and is inhibited by lead poisoning.
to summarize steps: glycine and succinyl CoA –> ALA –> porphobilinogen – hydroxymethylbilaine –> uroporphyrinogen III –> coproporphyrinogen III –> protoporphyrin to heme.
most important intermediates: protoporphyrin, ALA, uroporhyrin (from uroporphyrinogen III),
What does the 3rd heart sound represent?
lots of fluid. heard during rapid filling of the ventricle in mid diastole.
