Basic Science Flashcards
Describe the key transcription factors for cell signaling
SOX9-Cartilage
Mohawk-MKK-tendon
SATB2 osteoblasts
what is the CREST syndrome anti-body?
what is the basic science background regarding scleroderma?
How does the mechanism of Rifampin affect Gene transcription?
Binds to mRNA, which is the first step in gene transcription
what is the 16s ribosomal RNA
what is a gene?
Codon?
Exon?
Intron?
what is the relationship between systemic lupus and SNRMPS?
what is the relationship between fascioscapohumeral muscular dystropy?
Activated junk DNA
Bilateral winging
inability to whistle
Define Genotype, phenotype, karyotype
what are the two types of mutations?
- Suppressor Gene
- Activating mutation
Fibrous Dysplasia/Mccune-Albright
Describe the basic science behind Fibrous Dysplasia:
Activation mutation of GNAS1
causing sustained adenylate cyclase causing increase cAMP.
post zygotic somatic mutation
what is mosaicism and give clinical examples
two genotypes in the same organism
what is the basic science behind neurofibromatosis?
mutation in a supressor gene
turns off neurofibromin
Describe the difference between the two types of diseases with cafe-au-lait spots?
What is a mendelian disorder?
a single gene disorder
List the autosomal dominant structural protein disorder diseases:
List of autosomal recessive enzymatic gene defect diseases
List of x-linked recessive gene disorders
What is an x-linked dominant disease, and give an example of it:
what is the carter effect?
what are down syndrome ortho issues?
what is unlucky thirteen and its relationship to multiple myeloma?
Multiple myeloma equals round delections…..
why?
what is the the chromosomal deletion for prader-willi syndrome and what is it relationship to maternal imprinting?
Describe in more detail Genetic imprinting:
what is the chromosomal translocation for Ewing’s Sarcoma?
what are the ortho examples of chromosomal translocations?
where do the mesenchymal stem cells originate from?
what are the cell-cell proteins involved in limb formation?
Characterize the BMP protein
what are the therapeutic uses of BMP?
what is FOP?
what are the limb bud growth factors?
what is the clinical relevance of WNT?
Dorsal ventral formation
nail patella syndrome
osteoblast precursor
adult bone homeostasis
Describe the WNT/ Beta-catenin canonical pathway:
what are two types of bone formation?
Describe the basics of intramembranous ossification
In intramembraneous ossification, MSC cells form bone directly
High early WNT signaling first favors osteoblasts
RUNX increased
SOX-9 decreased
No cartilage model/ Woven bone
What are some orthopedic situations where intramembranous ossification occurs?
What is the clinical signficance of the clavicle as it relates to bone formation?
first bone to form in the fetus
last to ossify
intramembranous ossification
what is a clinical example of poor intramembranous ossification?
Cleidocranial Dysplasia
RUNX/CBFA1
Core Binding Factor 1
what are the clinical manifestions of cleidocranial dysplasia?
List the diseases associated with “Wormian Bones”
PORKCHOPS
what are the early signaling compnents that lead to endochondral ossification?
low early WNT signaling favors cartilage
Increased SOX-9
RUNX-2 decreased
Later WNT increases
Describe the steps for enchondral bone formation
MSCs first form cartilage
CARTILAGE MODEL
Osteoblasts form perichondrium
Cartilage replaced by bone
what are some clinical examples of enchondral ossification?
Growth plates
fracture repair (secondary healing)
Heterotopic ossification
synovial osteochondromatosis
LEARN this SCHEMATIC!
What are some clinical examples of Trisomy 21?
what are some genetic causes for short limbs?
FGF-
dwarfish
What are the key points about fibroblast growth Factor Receptor?
Describe the function of the hedgehogs:
Does high SHH production cause radial or ulnar development?
Ulnar
How does fibular hemimelia relate to Sonic the Hedgehog?
How do you characterize tibial bowing?
what does indian Hedgehog do?
what is the mechanism of action for PCN?
PCN inhibits petidoglycan synthesis
What are the antibiotics that inhibit cell wall synthesis?
PCN
Cephalosporins
Vancomycin
Bacitracin
Aztreonam
Imipenem
beta-lactams bind to surface of cell membrane
What antibiotics increase cell membrane permeability?
Polymixin
Nystatin-antifungal
Amphotericin-antifungal
What antibiotics inhibit protein synthesis by binding to ribosomal RNA?
bacteriostatic
Aminoglycosides
clindamycin
erythromycin
tetracycline
What antibiotics are bacteriocidal and bind to 30S subunit ,misread messenger RNA?
Gentamycin
Streptomycin
tobramycin
amikacin
neomycin
What is the mechanism of Rifampin ?
Inhibits RNA synthesis in bacteria
what is the mechanism of action of quinolones
inhibit DNA gyrase
associated with tendon ruptures
list some common complications associated with specific antibiotic usage:
aminoglycosides: ears and kidneys
tetracycline-teeth staining
cephalosporins- good in ortho
clindamycin-highest bone concentrations
cipro- tendon ruptures
imipenem- seizures
what does warfarin do?
affects vitamin k metabolism in the liver, limiting the production of factors 2,7,9,10
and proteins C and S
inhibits vitamin K dependent proteins from being carboxylated
Intrinsic pathway
What does heparin do?
Enhances the ability of anti-thrombin (AT-III) to inhibit factors IIA, 9A, 10A.
extrinsic pathway PTT
What is the mechanism of Aspirin?
Inhibits thromboxane A2 synthesis by irreversible binding COX in platelets and blocking platelet aggregation
What is the mechanism of Lovenox?
Complexes formed between AT-III and factors IIa, Xa.
What is the mechanism of action of LMWH?
inhibit factors Xa and IIa.
What are the three anticoagulation pathways?
Heparin–AT-III
Protein C-thrombomodulin-protein S
Tissue factor inhibitor
what is von willebrand factor?
promotes platelet binding to vessel walls;
carrier for factor VIII
treat deficiency with cryoprecipitate and desmopresin
What are potentiators of coumadin?
Flagyl
erythromycin
aspirin
sulfa
bactrim
heaprain
septa dylantin
Free Body analysis:
M=Fx(torque moment)
F= mass x acceleration
hip free body diagram
Body weight down x moment length=
abductor moment are x abductor weight
describe the piezoelectric effect
concave compression side is electronegative
convex tension is electropositive
What factors increase rigidity of external fixators:
Bone to Bone contact (most important)
Larger diameter pins
Additional pins
Decreased bone-rod distance (closer to leg)
increased mass of rods (stack the rods)
increase space between pins
circular fixators
List the biomechanical implants in Youngs Modulus order:
Highest to lowest
Ceramic
cobalt chrome
stainless steel
Titanium
Cortical bone
polymethylmethacrylate Cement
Poly Implant
Cancellous bone
tendon
ligaments
cartilage
what is the definition of toughness
resistance to fracture
What is the modulus of elasticity definition?
linear relationship between applied stress and resultant deformation
what is the elastic limit?
biomechanical point at which strain is no longer recoverable
What is a yield strength?
amount of stress necessary to produce a specific amount of permanent deformation, usually .2%
what is ultimate strength?
maximum strength obtained to failure
what is the elastic linear region?
proportional strain to stress applied…until yield point.
what is the plastic region?
curve past yield point in which stress is not reversible
does a brittle material have a large or small elastic region?
what about ductile
small plastic curve
large plstic curve
what is fatigue failure?
number of cycles to material failure at a specific stress level
Define endurance limit:
stress level at which a materaila can be cyclically loaded an infinite number of times withou failing.
what is the paronychia trilogy?
Herpetic whitlow
candida albicans
streph-acute bacteria
what are the flesh-eating bacteria?
Group A Strep with exotoxin
Vibrio Vulnificus-seawater
Aeromonas Hydrophilia-freshwaster
what are the common skin, fascia and muscle infections with the associated bugs?
review the soft tissue infection flow diagram from NEJM:
What is the most common bacteria for orthopedic Infections?
what gene is associate with MRSA?
MEC-A gene
codes for penicillin binding protein 2a
transmitted by horizontal gene transfer
plasmids, bacteriophages
drug of choice is Vanco.
what is the difference between HA-MRSA and CA-MRSA?
What are the guidelines for stopping Rheumatoid medications prior to arthroplasty surgery?
What is the mechanism of TXA?
blocks the formation of plasmin
decrease clots dissolving
what Upregulates RANKL and downregulates OPG?
increases bone resorption/destruction
Parathyroid hormone
Activated Vitamin D
Il-1N
TNF-A
PGE2
what down regulates RANKL and upregulates OPG?
decreases bone destruction
IL-4
TNF-B
Interferon N gamma
what transcription factors are associated with Tendon, Bone and Cartilage?
Mohwawk MKK- Tendon
SOX9-Cartilage
