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USMLE Step 1 > UWorld_1.20 > Flashcards

Flashcards in UWorld_1.20 Deck (20)
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1

Most common benign tumor of breast = 

fibroadenoma

2

breast biopsy, dx?

fibroadenoma

3

child w/severe intellectual disability + seizures + pallor @ substantia nigra, locus ceruleus, vagal nucleus dorsalis ==> dx/

PKU (phenulketonuria)

4

mechanism of PKU

  • lack of phenylalanine hydroxylase or tetrahydrobiopterin (BH4) [it's cofactor] ==> buildup of phenylalanine @ body fluids and CNS

5

colchicine: MOA/use/SE

  • inhibition of microtubular polymerization ==> prevention of aggregration  ==> disrupts chemotaxis and phagocytosis 
  • also inhibits formation of leukotriene B4
  • use = acute gouty arthritis
  • SE = nausea, abdominal pain, diarrhea

6

Common colonization location of staph aureus

nasal colonization

7

Microscopic steps of inflammation

  • margination
  • rolling
  • activation
  • tight adhesion and crawling
  • transmigration

8

Key molecular components of rolling

  • loose binding via sialyated carbohydrate groups
  • @ PMNs = L-selection
  • @ endothelial cells = E-selectin/P-selectin

9

Key molecular components of tight adhesion and crawling

  • CD18 beta 2 integrins (Mac-1 and LFA-1) bind to ICAMs on endothelial cells

10

Key molecular components of transmigration

  • PMNs squeeze between cells and out of vasculature
  • migrate via integrin attachments and adherence to platelet endothelial cell adhesion molecule 1 (PECAM-1)

11

Middle meningeal artery is a branch of the...?

maxillary artery

12

Presentation of tuberous sclerosis

  • bilateral renal angiomyolipomas
  • cortical tubers
  • subependymal hamartomas @ brain
  • cardiac rhabdomyoma
  • facial angiofibroma
  • leaf-shaped patches of skin lacking pigment (ash-leaf patch)
  • autosomal dominant condition

13

When is K permeability highest during AP?

during repolarization phase

14

Calculation of filtration fraction

  • FF = (glomerular filtration rate)/(renal plasma flow)
    • renal plasma flow = (1-Hct)(Renal blood flow)

15

Amino acids w/3 titrable protons (==> 3 pKas on titration curve)

  • Histadine
  • Arginine
  • Lysine
  • Aspartic acid
  • glutamic acid
  • cysteine 
  • tyrosine

16

Enoxaparin: MOA

  • low molecular weight heparin
  • MOA: binding and activating antithrombin III
    • active ATIII prevents factor Xa from: prothrombin ==> thrombin
  • ==> anticoagulant effect

17

Characteristics of mastocytosis

  • abnormal proliferation of mast cells
  • ==> increased histamine secretion
  • ==> increased gastric acid production by parietal cells of stomach

18

Sensitivity =

Specificity = 

Sens = TP/(TP + FN)

Spec = TN/(TN + FP)

19

Digoxin clearance

via kidneys

20

Glucorticoids stimulate...?

liver (gluconeogenesis/glycogenolysis)

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