BS 2 Flashcards by Lo Kola

Articular hyaline cartilage:
How get nutrition
Top 3 components

Diffusion nutrition from synovial fluid
- Avascular (why doesn’t heal)
Components: H2O, PG, collagen (type 2 = car-two-lage)

How well did you know this?

Not at all

Perfectly

Describe collagen structure

3 alpha collagen chains in a triple helix

How well did you know this?

Not at all

Perfectly

Where do you find type X cartilage

Fracture callus
Hypertrophic zone growth plate
Calcified tidemark of articular cartilage

How well did you know this?

Not at all

Perfectly

What are 2 genetic disorders that affect type 2 collagen of cartilage?

Achond - lethal kind

Spondyloepiphyseal dysplasia (SED-C) - congenita
- Mentally normal
- Proportional dwarfism (trunk + limbs)

How well did you know this?

Not at all

Perfectly

What is the structure of PG

HA backbone
Protein core
Chondroitin + keratan sulfate

Overall negative charge molecule

How well did you know this?

Not at all

Perfectly

Diastrophic dysplasia:
Inheritance
Mutated protein
Clinical presentation

AR
Sulfate transporter mutation - can’t get sulfate into cells to make PG (chondroitin and keratin sulfate)

Presentation
- Dwarfism
- Hitchhiker thumb
- Cauliflower ear

“If your sulfate transporter isn’t working, you have to hitchhike”

How well did you know this?

Not at all

Perfectly

What is the only cell in cartilage? What TF controls it?

Chondrocytes - SOX9

How well did you know this?

Not at all

Perfectly

What are the layers of cartilage from superficial to deep

Tangential - chondrocytes lay flat
- Most H2O + lubricin, least PG
Transitional/radial
Deep zone
Tidemark - contains Ca2+ cartilage (type X)
Subchondral bone
Cancellous bone

How well did you know this?

Not at all

Perfectly

What are the 2 types of cells in synovium

Type A = mArcophAge like cells
- Removes debris from joint
- From bone marrow (hematopoietic)

Type B = fiBroBlast like cells
- Mesenchymal derived
- Make synovial fluid - lubricin, etc

How well did you know this?

Not at all

Perfectly

What molecule is responsible for synovial fluid viscosity

Hyaluronic acid

How well did you know this?

Not at all

Perfectly

Name molecules in synovial fluid

Hyaluronic acid
Lubricin

HA binds lubricin
Lubricin works via boundary lubrication

How well did you know this?

Not at all

Perfectly

How does cartilage change with OA

Wet - increase H2O
Decrease modulus of elasticity (stress strain curve has lower slope)

How well did you know this?

Not at all

Perfectly

How does cartilage change with aging

Less H2O - dry
Brittle = increased mod of elasticity
Increased decorin

How well did you know this?

Not at all

Perfectly

What signaling molecules are upregulated in OA

IL 1beta
MMPs
ADAMTS

How well did you know this?

Not at all

Perfectly

What is an antimicrobial peptide over expressed in psoriasis patients

Cathelicidins
Increased keratin in wound helaing

How well did you know this?

Not at all

Perfectly

While interleukin causes the liver to bump CRP + ESR

IL 6

Name the class of drug + specific mechanism
Etanercept
Infliximab
Adalimumab

TNF alpha blockers

Etanercept - receptor fusion protein
Infliximab - chimeric IgG Ab
Adalimumab - mAb

Mechanism of anakinra

IL 1 receptor blocker

Mechanism of tocilizumab

IL6 receptor antibody

Rituximab mechanism

Ab to CD 20 antigen (B cell inhibitor)

What does each nomenclature mean
-mab
-ximab
-zumab
-cept

-mab = mAb
-ximab = chimeric mAb (mouse+human)
-zumab = humanized mAb
-cept = fusion of a receptor to Fc part of IgG

What is the first cell recruited to fracture hematoma?

Neutrophils - “inflam phase”

Why cytokines do macrophages release

IL1/6
TNF alpha
VEGF
M-CSF

What cell mediates osteolysis?
What cytokine is release that stimulates osteoclasts?

Macrophages - osteolysis
RANKL - osteoclasts - dissolve bone

What is tabetic arthropathy? Describe clinical presentation

Tabes dorsalis aka neurosyphilis Joint changes before neuro diagnosis XRs look WAY worse than the sx Will also have unsteady gait, bloody effusion w/ neg infx wu

Diagnose: Neuropathic arthritis XR Loss of pain/temp sensation in a capelike distribution

Syrinx causing neuropathic arthritis Often middle aged Often shoulder or elbows affected - 1 joint

What is black cartilage disease Inheritance

Alkaptonuria AR Homogentisic acid oxidase Excess homogentisic acid deposited in joints - tints matrix black Predisposes to Ca deposition in cartilage (chondrocalcinosis) and early OA (young joint replacement)

Name that arthritis: Viking heritage FHx arthritis + liver disease Hyperpig skin Chondrocalcinosis on XRs w/ +crystals on aspirate Screening test Trt

Hemochromatosis w/ CPPD - Hereditary excess iron absorption "Viking curse" Bronze DM - cirrhosis, DM, skin pigmentation Screen w/ transferrin + ferratin tests Trt: blood letting for iron control

Describe the crystals: Gout CPPD

Gout - yellow, urate, needle, neg birefringe CPPD - blue, post birefringe

Tumoral calcinosis: 2 causes What kind of crystals are deposited

Too much blood PO4 1. Renal failure - can't excrete 2. Familial tumoral calcinosis - low FDF23 = can't excrete Ca hydroxyapatite

What diseases are these HLAs associated with HLA B27 HLA DR3 HLA DR4

HLA B27 - ank spond, JRA HLA DR3 - SLE HLA DR4 - RA

Describe the pathophys of RA

Genetically susceptible person - HLA DR4/DW4 Some antigen trigger B cells make auto Abs vs RF, aCCP CD4 T cells infiltrate around jt tissues - Release TNFa, IL 1/6 Inflam cells proliferate synovium = pannus

What cells are in RA pannus

CD4 T cells Macrophages - TNFa, IL1/6 Fibroblast (type B) - MMPs, proteases, RANK-L

What 2 Abs are diagnostic for RA?

RF = IgM to IgG Anti-CCP = anti cyclic citrullinated peptide Abs - Most sensitive + specific for RA

HST rxn Type 1 - cell type and example Type 2 - " "

Type 1 - IgE mediated, mast cells release histamine Ie latex allergy Type 2 - IgM or IgG mediated Ie myasthenia gravis, transfusion reaction (ABO mismatch)

SLE: Pathophys 3 Abs

Ag-Ab immune complex deposition - T3 HST rxn Sensitive: ANA Specific: Anti-dsDNA Anti-Sm (=RNA)

Sjogren: Pathophys 2 Abs Other immune cell involvement

CD4 T cells infiltrate saliva and lacrimal glands - Dry mouth/eyes Abs vs ribonucleoproteins: SS-A(Ro) + SS-B(La) Increased IgA

Scleroderma: Pathophys 3 Abs

CD4 T cells activate fibroblasts More type 1 collagen deposition Calcinosis ANA+ Localized = CREST = anticentromere Ab Diffuse = anti-DNA topoisomerase I Ab

What is the triad of reactive arthritis (Reiter's syndrome) Cause Trt

Cant see - conjunctivitis Cant pee - urethritis Cant bend the knee - arthralgia "Red eyes, burning pee, joint effusions and pain" Chlamydia Diarrheal causes: Shigella, salmonella Trt - supportive, treat underlying bug if possible