Basic Science Flashcards
What is the most common culture isolate in necrotizing fasciitis?
Polymicrobial
What is the MOA of calcitonin?
Binds to osteoclast receptors, which decreases the ruffled border, followed by cell retraction, and therefore arrest of bone resorption
What is denosumab?
IgG2 monoclonal antibody against RANKL
What is teriparatide?
recombinant PTH; anabolic effect via activating osteoblasts
What effects does calcitonin have on osteocytes?
inhibits apoptosis and increased expression of sclerostin (a Wnt-signaling inhibitor)
What is the MOA of enoxaparin?
Enoxaparin binds to and increases the activity of antithrombin III
What is the MOA of osteoprotegrin?
Binds to and sequesters RANKL preventing osteoclastic differentiation
What artery provides the blood supply to the outer third the long bone diaphysis?
periosteal arteriole
What artery provides the blood supply to the inner two thirds of long bones?
Nutrient artery
Is DBM osteoconductive or osteoinductive?
It is both; but not osteogenic
Is BMP osteodconductive, osteoinductive, or osteogenic?
osteoinductive
What is the mechanism of BMP in bone formation?
activates mesenchymal cells to transform into osteoblasts and produce bone
What is the mechanism of osteoprotegrin in bone formation?
OPG inhibits both osteoclast activation and differentiation by acting as a decoy receptor for RANK-L.
Bridge plating relies on what kind of bone healing?
Relative stability; Secondary (endochondral) bone healing through chondrocytes proliferation and hypertrophy
Anatomic fracture reduction relies on what time of bone healing?
Absolute stability; primary (intramembranous) bone healing through Haversian canals and cutting cones
What is DBM made up of?
collagen, TGF-beta, BMP, and residual calcium; it is bone osteoinductive and osteoconductive but not osteogenic
What are the FDA indications for use of recombinant human (rh) BMP-2?
Acute open tibia shaft fractures treated within 14 days and single level ALIFs
What is the definition of strain?
Change in length / original length of an object due to an external force
Salter-Harris type I fractures typically occur through which zone of the physis?
Zone of provisional calcification
What region of the physis does collagen type X play a prominent role?
Type X collagen is important for bone mineralization and is produced by hypertrophic chondrocytes in the zone of hypertrophy.
What is the mechanism of Sclerostin?
Sclerostin impedes osteoblast proliferation and function by inhibiting the Wnt signaling pathways and thus inhibits bone formation.
What is the MOA of anakinra?
Receptor antagonist of IL-1
What agar does Neisseria grow on?
Thayer Martin
What agar does mycobacterium grow on?
Lowenstein Jensen
What agar does Kingella kingae grow on?
aerobic blood agar (can take a week)
