MRC Basic Science - All the shit Flashcards
What is the most sensitive and specific test for RA?
Anti-CCP
What is the MoA of PCN’s and Cephalosporins?
Cell wall inhibitors
What is the MoA of Vancomycin?
Cell wall inhibitor
What is the MoA of Aminoglycosides (Gentimicin, Tobrimicin, etc)
Inhibits protein synthesis 30s ribosome
“Buy AT 30”
What is the MoA of Tetracycline?
Inhibits protein synthesis 30s ribosome
“Buy AT 30”
What is the MoA of Macrolides? (Erythromycin, Azithromycin, Clarithromycin)
Inhibits protein synthesis 50s ribosome
“CCEL at 50”
What is the MoA of Clindamycin?
Inhibits protein synthesis 50s ribosome
“CCEL at 50”
What is the MoA of Linezolid?
Inhibits protein synthesis 50s ribosome
“CCEL at 50”
What is the MoA of Rifampin?
Inhibits RNA Polymerase
What is the MoA of Quinnolones (Ciprofloxacin, Levofloxicin, -floxicin)?
Inhibits DNA Gyrase (= Topoisomerases)
What signaling factors are responsible for:
- Apical growth
- Radial/ulnar differentiation
- Dorsal/Ventral axis
- Apical growth - Fibroblast Growth Factor (FGF..think of Achondroplasia!)
- Radial/ulnar differentiation - Sonic Hedgehog
- Dorsal/Ventral axis - Wnt
- ) What gene is indicated in Multiple Epiphyseal Dysplasia?
- ) What type of Collagen effected in MED?
- ) What is characteristic presentation?
1.) COMP
2.) Collagen IX
3.) Bilateral, effecting multiple joints; problems on both sides of the joint! NO spine involvement!
(*If has spine involvement -> then think of Spondylo-Epiphyseal Dysplasia and involvement of Collagen II…to help remember - think that nucleaus polposus is Collagen II!)
What is it preferable to plate on the tension side of fractures?
Minimizes the bending stress on the plate. When plate is on the tension side and the fracture is loaded it tends to close down so that the bone takes more of the load and there is less load on the plate. If you plate on the compression side, when the bone is loaded the tension side will open during loading and the plate will see more bending stress.
What does viscoelastic mean?
Strain varies by rate of loading
What is the composition of articular cartilage?
75% water
Next largest component is Collagen: 15%
What is the most common type of Collagen in Cartilage?
What other type is very common?
Type II Collagen
Type X Collagen (makes things hard!)
- Calcified tidemark/Hypertrophic zone/hypertrophic chondrocytes
What are important facts about the tangential/superficial zone of cartilage?
Flat tangential cartilage cells
Highest Lubricin (boundary lubricant) and Collagen%
Highest water/Least PG synthesis
As you go deeper in the cartilage layers what happens to the collagen?
Larger collagen diameter and becomes more vertical.
What is the main molecule associated w/ synovial fluid viscosity?
Hyaluronic Acid (squeeze film/fluid-film lubrication)
What is the difference b/t aging cartilage and cartilage in OA?
OA is wet and soft! (decrease modulus of elasticity, loss of proteoglycans)
Aging - dry, brittle, and stiff (Increased decorin, decreases water, increases modulus of elasticity)
What type of arthritis has black coloration to it? (black cartilage, urine black, black/blue sclera and ear lobe)
Ochronosis (due to Alkaptonuria) - get arthritis early in life.
AR defect of homogentisic acid oxidase
\+Viking/celtic family hx Arthritis and liver dz Hyperpigmented skin Chondrocalcinosis & "hook-like" spurs on MCPs (+) Rhomboid crystals
Hemochromatosis w/ CPPD
Get “bronze DM” = liver dz, DM & hyperpigmentation of skin as late finding
What crystals are a/w Gout?
Yellow Urate crystals
Negative birefringence
Needle shaped
What crystals are a/w pseudogout aka CPPD?
Blue Calcium Pyrophosphate crystal
Positive birefringence
Rhomboid shaped
What are the 2 common causes of Tumoral Calcinosis?
“Bad beans or bad genes!”
- ) Chronic renal failure - can’t excrete phosphate
- ) Genetic decrease of FGF-23 activity (*Remember FGF-23 stands for “Farewell to Fosphate”…so if have a decrease then you keep more phosphate in your serum)
What should you think of when you see juxta-articular erosions?
Rheumatoid Arthritis