Miller's Biology Flashcards
high strain cells in healing
fibroblasts -> fibrous union
cells that respond to medium strain, low oxygen in bone healing
chondroblasts -> cartilage
cells that respond to low strain, high oxygen in bone healing
osteocyte/osteoblast -> bone healing/formation
What secretes sclerostin?
Function of sclerostin?
Osteocytes
inhibits osteoblasts via Wnt pathway
PTH effect on sclerostin
increases
Calcitonin effect on sclerostin
decreases
Osteoclast cell of origin
macrophage lineage
molecules involved in osteoclast attachment to bone
integrins to vibronectin (RGD sequence)
major proteolytic enzyme in bone resorption
cathepsin K
mutation in Cathespine K causes
Pyknodysostosis
Cath’rine Pyknod the wrong profession so we stole her distal phalanges (represents distal phalanx osteolysis)
mutation in carbonic anhydrase causes
osteopetrosis
what does calcitonin act on
what is effect
acts on receptor on osteoclast to decrease its activity
secreted by tumor cells to cause osteolysis
IL 1
PTHrP
tensile strength to bone
collage
gives compressive strength to bone
proteoglycans
single most important factor determining bone healing
blood supply
cartilaginous extracellular matrix is degraded in fracture healing by
MMP13
increases mechanical strenth of callus and produces nano motion
LIPUS
how is cancellous graft incoroporated
creeping substitution
cell of origin for calcitonin
clear cells of thyroid
physis zone of rickets
zone of provisional calcification
PHEX gene mutation
X linked familial hypophosphatemic rickets
cannot absorb phosphate
rickets and patient is totally bald
Vit D dependent rickets
medications that disrupt bone mineralization
prednisone PPIs seizure meds SSRIs heparin
clonazepam can cause osteoporsis via
increase in sclerostin
1 compression fx increases risk of hip fx by
5x
avg year of bisphosphonate use leading to atypical subtroch fx
4 years
osteoporosis med CA in Pagets
teriparatide (forteo)
progression of nerve recovery sx’s
sympathetic activity pain temp touch proprioception motor
most prominent proteoglycan in tendon
decorin
bglycan
initial collagen in tendon healing
III
proteoglycan that regulates tendon diameter
decorin
tendon is weakest at what point in healing process
7-10 days
stress equation
Force/Area
strain equation
change in length/original length
maximum stress a material can sustain before breaking
ultimate strength
diff btw yielf point and fx point
ductility - how much it can bend before breaking
molecule of ligament that allows for toe region
elastin
instant center of motion in wrist
capitate
mutation causing defective sulfate transporter
Diastrophic Dysplasia
Genetic Defect in SOX9
Campomelic Dysplasia
- short long bones
- bowed femurs
- all die at infancy: hear, kidney, lung defective
Location of Type X collagen in cartilage
Calcified zone
Cartilage layer with highest Lubricin
Tangential zone
Type A cells of synovium
mAcrophage like cells that remove waste and such
What molecule contributes most to joint fluid viscosity
Hyaluronic Acid
Nonnewtonian - less viscous with stirring
Thixotropic - flows more easily with shear stress and is shear thinning
Synovial fluid
CAuses of Neuropathic Arthritis
Charcot (DM)
Syphilis (hip/knee)
Syrinc (shoulder/elbow)
Leprosy
AR defect of homogentisic acid oxidase
Ochronosis (Alkaptonuria)
Diabeteis, increase LFT’s, hyperpigemented skin
Mulitple arthritic joints
Hemochromatosis (Bronze Diabetes)
- elevated ferritin
crystal with X in it
Ca+ Oxalate
Positive birefringent
Pseudogout - calcium pyrophosphate
Normal function of FGF-23
decreaese renal reabsorption of PO4 (thus decreases serum phosphate)
2 causes of tumoral calcinosis
FGF23 defect
Renal disease
Synovial biopsy shows macrophages with CHICV RNA “hijacked” and natural killer cells
Chikungunya = chronic viral polyarthritis
- RNA alpha virus via mosquitos
Arthritis with morning stiffness lasting longer than an hour
RA
Mopst sensitive and specific lab testing for RA
Anti-CCPa
What is humoral immunity
soluble components in the serum that kill microorganisms inactive toxins clump and lyse RBCs increase macrophage phagocytosis
Main cell involved in Humoral immunity
B cell -> secreste Ig
What is rheumatoid factor
IgM to IgG
ANA + diseases
Lupus
Scleroderma
Type of reaction
- Aseptic lymphocyte vasculitis-assoc lesion
Type IV hypersensitivity
Seronegative Spondyloarthropathies
Ank Spon
Psoriatic Arthritis
Reactive Arthritis (Reiter’s Syndrome)
Most common cause or Reiter’s
Chlamydia
Diarrheal Illness: Shigella, Yersinia, Salmonella
Most common bug of cellulitis
Group A strep
Most common bug of necrotizing fasciitis
Group A strep (strep pyogenes)
Skin finding particular to nec fasciitis
non-blanching skin
bla gene mutant
resistant to penicillin
mecA gene
provides methicillin resistance
Alternative to Vanc for MRSA
Linezolid
When to repeat intraop abx
1 L blood loss
at 3 hours
Heavy EtOH effect on bone
decreases
impairs fx healing
inhibits Wnt pathway
decrease fibroblast propduction of collagen type I
When to stop RA biologics
For the duration of dosing + 1 wk
indication that Lupus is severe
nephritis/renal issues
lysine analog that binds plasminogen
TXA
how much bacteria do you need to cause an infection
> 100k
Indication that Lupus is severe
nephritis/renal issues
Abx for human and animal bites
Augmentin
How much bacteria do you need to cause an infection
> 100k
culture negative bacteria in osteomyelitis in kid think
- how is it ID’d in the lab
Kingella Kingae
- PCR
Cytokine that triggers proteolytic enzymes that destroy cartilage in infection
IL-1
Culture negative bacteria in osteomyelitis in kid think
- how is it ID’d in the lab
Kingella Kingae
- PCR
MSK infection after URI in < 5 yo
Kingella Kingae
Treatment of gonococcal arthritis
Ceftriaxone
Intracellular gm - diplococci
gonnococcal
Lytic lesion in late stage AIDS and cate exposure
Bartonella
Treatment for Chronic non-bacterial osteomyelitis
NSAIDs
aka- Chronic Recurrent Mulitfocal Osteomyelitis
it’s an autoinflammtory bone disease
adult version is SAPHO- synovitis Acne pustulosis hyperostosis osteitis
Rrisk of HIV transmission with single needle stick
0.3%
Single stick tramission risk with hep B
30%
Single stick transmission risk with Hep C
2-3%
Anti-centrome ab’s
CREST syndrome
Anti-histone
drug induced Lupus
Anti-U
mixed connective tissue diseases
anti-smith
Systemic Lupus
how to treat bilateral winging in fascioscapulohumeral muscular dystrophy
scapulothoracic fusion
2 fertilized eggs that merge together that create one organism
chimera- XX/XY = gives rise to remale phenotype
Turn on or off gene
- fibrous dysplasia
- NF1
fibrous dysplasia-> on (somatic mutation NOT inherited)
NF1- turning of tumor suppressor gene
only X linked dominant
hypophophatemic rickets
ortho issue in Down syndrpome
Laxity
COL6 on chromosome 21
- collage VI is overexpressed
cancer cause by chromosmal deletion
Mulitple Myeloma
- chromosome 13 copy is missing
which embryologic layer dores msk system come from
mesoderm
marker of osteoblast differentiation
alk phos
- the by product of conversion of pyrophosphate (PPi) to phosphate ion which favors ossification
- via hydrolosys
rickets like picture with low alk phos
hypophospohatasia
- AR where PPi accumulates and inhibits bone mineralization
most potent/abundant osteoblast stimulator
PGE2
gene that guides radial/ulnar limb growth
Sonic hedge hog
- hand - high levels is pinky side, low side is thumb side
genetic basis for fibular hemimelia
poor sonic hedge hog protein
genetic basis for postaxial polydactyly
sonic hedge hog overexpressed
gene stimulates/regulates dorsal/ventral limb pattern growth
Wnt
bone formation method by which distraction osteogenesis works
intramembranous
first bone to ossify
clavicle
- also the last
notable enzymes of osteoclasts
Carbonic anhydrase Chloride channel giving rise to hydrochloric acid Cathepsin K- dissolves organic matrix TRAP- a marker for osteoclasts Vacuolar H+ ATPase
Cathepsin K deficiency disease
pyknodysostosis
enzyme messed up in Morquio
galactose sulfatase
defect in enzyme function is what inheritance
AR
defect in protein function is what inheritance
AD
avoid ligamentous procedures in
Ehlers Danlos
Virchow’s Triad
hypercoagability
endothelial damage
stasis
Indications for IVC filter
CA to anticoagulatio
Failure of anticoagulation
complication from anticoagulation
Indications for IVC filter
CA to anticoagulation
Failure of anticoagulation
complication from anticoagulation
Andexanet
antidote for Xarelto
recommendation for long plane flights
stay hydrated
walk the cabin
treatment for ARDS
ventilation with PEEP to keep alveoli open
- only intubate if necessary
best clinical indicator of inadequate fluid rescitation
best lab for inadequate resus
urine output < 30cc/hr
lactate > 2.5
best clinical indicator of inadequate fluid resuscitation
best lab for inadequate resus
urine output < 30cc/hr
lactate > 2.5
earliest sign and most sensitive/specific sign of malignant hyperthermia
uneplzined rise in end tidal CO2