UWorld_1.17 Flashcards
Presentation of Fragile X
- more common/severe in males
- mild-moderate cognitive impairment, speech/language delay, ADHD, mild autism
- macroorchidism
- prominent jaw, long face, large ears, cleft palate
- mitral valve prolapse
- short height, joint laxity, scoliosis, pes cavus, double-jointed thumbs, single palmar crease
Cause of Fragile X
- highest inherited cause of cognitive impairment
- increase in trinucleotide repeat in FMR1 gene on X chromosome
Presentation of CNIII palsy
- unilateral headache
- eye pain
- dilated, unreactive pupil
- diplopia
- ptosis
- ipsilateral eye = “down and out”
Cause of CNIII palsy
- CN III runs between posterior cerebral and superior cerebellar artery
- aneurysm @ either vessel ==> CNIII palsy
Calculation of number needed to harm
- NNH = number of people that must be treated in order to harm 1 person
- NNH = 1/attributable risk
- attributable risk = adv.event ratetreatment - adv.event rateplacebo
Isoproteronol MOA
- agonist at B1 and B2 receptors w/no alpha receptor activity ==>
- increase in cardiac contractility (B1)
- vascular smooth muscle relaxation (B2)
Major process used to maintain blood glucose levels @ 18-24 hrs
- gluconeogenesis = glucose formed from lactate, glycerol, and amino acids
Important steps in gluconeogenesis
- pyruvate ==> oxaloacetate (pyruvate carboxylase) [@ mitochondria]
- OAA ==> malate (malate dehydrogenase) [@ mitochondria]
- malate ==> OAA ==> phosphoenolpyruvate (PEP carboxykinase = “PEPCK”) [@ cytosol]
- PEP ==> glucose (fructose-1,6-bisphosphatase & glucose-6-phosphatase)
unsteady gait + blanching nests of distended capillaries + pulmonary infections ==> dx? + mechanism
- Ataxia telangectasia
- [autosomal recessive] mutation @ ATM (“Ataxia telangectasia mutated”) gene = DNA break repair ==>
- sensitive to xray radiation
- cerebellar ataxia
- telangectasias = blanching nests of distended cappilaries
- predisposed to hematologic malignancies
- IgA deficiency ==> predisposition to respiratory infections
Nerve coursing near piriform recess + fxn
- internal laryngeal nerve (branch of CN X) courses superficially through mucosa @ piriform recess
- fxn = afferent cough reflex
- can be damage by food objects caught in piriform recess or in efforts to retrieve them
Factors ==> increased risk of renal calculi
- increased concentrations of:
- calcuim
- uric acid
- oxalate
- phosphate
- decreased water
Factors ==> decreased risk of renal caculi
- increased water intake
- increased citrate ==> binds free Ca and prevents precipitation and facilitates excretion
Rates of metabolism of various non-glucose sugars
- Fructose = fastest
- phosphorylated @ liver ==> fructose-1-P ==> bypasses PFK-1 = rate-limiting step
- other sugars metabolized slower than fructose:
- Galactose ==> glucose-6-P ==> glycolysis
- Mannose ==> fructose-6-P ==> glycolysis
Cresent formation @ kidney on light microscopy ==> dx?
rapidly progressive glomerulonephritis
Mechanism of rapidly progressive glomerulonephritis
- RPG ==> formation of crescent formation + focal necrosis
- crescents = glomerular parietal cells, monocytes, macrophages, fibrin ==> sclerotic ==> irreversible renal injury
Muscle contraction @ skeletal msucle vs. cardiac muscle
- skeletal muscle
- AP ==> L-type-Ryr ==> Ca in T-tubule system (most of Ca from sarcoplasmic reticulum) ==> contraction
- NO DEPENDENCE ON EXTRACELL Ca
- cardiac muscle
- AP ==> opening L-type Ca channels ==> entry of Ca ==> contraction
- DEPENDENT ON EXTRACELL Ca
Vascular rxn to intimal/endothelial injury
- hyperplasia and fibrosis
- mostly mediated by medial smooth muscle cells
- injured endothelial cells release platelet-derived growth factor ==> migration and proliferation of mSMCs
- vascular cell-adhesion molecules (VCAMs) allow attachment of WBCs ==> release of cytokines ==> also attract mSMCs
Embryonic origin of melanocytes = ?
neural crest cells
intensly pruritic rash on flexor surfaces, worse at night, usually @ kids or those who work w/kids ==> dx? + mechanism
- Scabies = infestation of sarcoptes scabiei mite
- Type IV hypersensitivity rxn to mites and eggs
- erythematous papules + excoriations; rapidly spreading
Characteristics of HepA infection
- commonly asymptomatic or subclinical (anicteric) in children; self-lmiting
- can also: N/V, jaundice, RUQ pain, malaise/fatigue, aversion to smoking
- usually uncommon but more severe @ adults
Extent/fxn of mucous and cilia @ lungs
- cilia = trachea ==> respiratory bronchials
- mucous (goblet cells) = interspersed from trachea ==> larger bronchials (not present @ terminal bronchials)
- mucous + cilia ==> mucociliary clearance of foreign particles and organisms
Common organisms + treatment of urethritis in young male
- organisms = N. gonorrheae or C. trachomatis
- N. gonorrhea tx = ceftriaxone
- C. trachomatis = doxycycline or azithromycin
Tx of acute mania
- mood stabilizers = lithium, valproate, carbamazepime
- atypical antipsychotic = olanzapine
