wound healing

Question 1

key growth factor in wound healing

Answer 1

PDGF (chemotaxis; activate fibroblasts, macs (to secrete GFs for prolif and angio), PMNs, smooth mm cells; angiogenesis; epithelialization; accelerates wound healing)

Question 2

tissue injury exposes 3 things.

Answer 2

collagen, platelet activating factor, tissue factor

Question 3

platelet activating factor?

Answer 3

generated by phospholipase in endotheliu to increase inflammatory cells and activate plts

Question 4

chemotactic factors for inflammatory cells?

Answer 4

PDGF, IL8, LTB4, C5a, C3a, PAF, TNFa, IL1f

Question 5

chemotactic factors for fibroblasts?

Answer 5

PDGF, EGF, FGF

Question 6

angiogenesis factors?

Answer 6

hypoxia, PDGF, EGF, FGF, Il8

Question 7

epithelialization factors?

Answer 7

PDGF, EGF, FGF

Question 8

bradykinin

Answer 8

released in Type I hypersensitivity
peripheral vasodil, pulm vasocon, bronchoCONstriction, increased permeability
inactivated by ACE in lungs

Question 9

histamine release?

Answer 9

mast cells (tissue), basophils (blood)

Question 10

nitric oxide NO = endothelium derived RELAXING FACTOR

Answer 10

arginine precursor

NO activated guanylate cyclase, inc cGMP to dilate SMOOTH MUSCLE.

Question 11

what has the opposite effect of nitric oxide?

Answer 11

endothelin (constrict smooth muscle)

Question 12

what causes fever?

Answer 12

IL-1 cytokine (PGE2 mediated in hypothalamus)

Question 13

NSAIDs effect on fever?

Answer 13

decrease PGE2 synthesis. decrease fever.

Question 14

IL-10

Answer 14

decreases the inflammatory response.

Question 15

interferons…?

Answer 15

inhibit viral replication (activate macs, NK cells, T cells)

Question 16

acute phase reactants?

Answer 16

released by IL-6 mostly
CRP (activate complement)
amyloid A
fibrinogen
haptoglobin
ceruloplasmin
a1 antitrypsin, C3
*(stop: albumin, prealb, transferrin)

Question 17

adhesion molecules? ROLLING ADHESION

Answer 17

L-selectin (leukocytes) bind E-selectins (endothelial) and P-selectins (plt)

Question 18

B2 integrins (CD 11/18 molecules)? ANCHORING ADHESION

Answer 18

B2 integrins on leukocytes bind ICAMs on endothelial cells
anchor and help diapedesis (migration into cell)

Question 19

classic complement pathway

Answer 19

unique: C1, C2, C4
activated buy IgG or IgM and antigen.

Question 20

alternative complement pathway

Answer 20

unique: B, D, P
activated by endotoxin, bacteria, others

Question 21

common complement?

Answer 21

C3

Question 22

what electrolyte required for both complement pathways?

Answer 22

Mg

Question 23

C3a C4a C5a are also referred to as

Answer 23

anaphylotoxins (increase vasc perm, bronchoconstr, activate mast/baso)

Question 24

MAC membrane attack complex complement

Answer 24

C5b, C6b, C7b, C8b, C9b
cause cell LYSIS via hole in cell membrane

Question 25

opsonization?

Answer 25

targeting of Ag for immune response mediated by C3b and C4b

Question 26

PGI2 and PGE2 fxn

Answer 26

vasoDILATION, bronchoDILATION, increase permeability, inhibit plt

Question 27

NSAIDs vs ASA on COX

Answer 27

NSAIDs inhibit reversibly ASA inhibits irreverisbly and inhibit plt adhesions by decreasing TXA2

Question 28

steroids on COX

Answer 28

inhibit phospholipase so phospholipids cannot become arachidonic acid (so decrease inflammation)

Question 29

lipoxygenase pathway (leukocyte derived)... leukotrienes.

Answer 29

also arachidonic precursors.

Question 30

LTC4 LTD4 LTE4 fxn

Answer 30

slow reacting substance of anaphylaxis... bronchoCONSTRICTION, vasoCONSTRICTION then increased permeability (wheal and flare)

Question 31

LTB4

Answer 31

chemotactic for inflammatory cells

Question 32

NE vs E release

Answer 32

NE released from sympathetic postganglionic neurons AND medulla Epi just released from medulla

Question 33

hormones released with inflammation?

Answer 33

CRF, ACTH, ADH (keep water), GH, Epi, NEpi

Question 34

superoxide anion radical O2-

Answer 34

made by NADPH oxidase cell defense: superoxide dismutase CGD: NADPH issue can't make O2-

Question 35

hydrogen peroxide H2O2

Answer 35

made by: xanthine oxidase cell defense: glutathione peroxidase, catalase

Question 36

wound healing phases?

Answer 36

1. inflammation (1-10 days) 2. proliferation (5 days - 3 wks) 3. remodeling (3 wks - 1 yr)

Question 37

what type of collagen in proliferation phase?

Answer 37

3 to 1 ... by the end of 3 wks

Question 38

how fast is epithelialization & p. nerve regen?

Answer 38

1-2 mm/day

Question 39

remodeling is what action in wound healing?

Answer 39

crosslinking of type I collagen

Question 40

main cell type at 2 days, 4 days, 5+ days in wound healing?

Answer 40

0-2: PMN 3-4: mac 5+: fibroblasts**

Question 41

fibronectin?

Answer 41

released by fibroblasts, chemotactic for macs, anchors fibroblasts.. makes up provisional matrix with HYALURONIC ACID

Question 42

fibroblasts replace fibronectin-fiber with...?

Answer 42

collagen

Question 43

most important factor in healing open wounds vs closed wounds?

Answer 43

open: epithelial integrity (secondary intention) closed: tensile strength (primary intention)

Question 44

strength layer of bowel?

Answer 44

submucosa

Question 45

when to take out sutures

Answer 45

face: 1 wk other: 2 wks

Question 46

weakest time for bowel anastomosis?

Answer 46

3-5 days

Question 47

myofibroblast function in scar; how to communicate

Answer 47

smooth muscle-fibroblast; communicate via gap junction healing by secondary intention - wound contraction!

Question 48

type I collagen

Answer 48

MC. skin, bone, tendon, healed wound

Question 49

type II collagen

Answer 49

cartiage

Question 50

type III collagen

Answer 50

wound healing.... blood vessels, skin happens day 8 thru 1 year

Question 51

type IV collagen

Answer 51

basement membrane

Question 52

type V collagen

Answer 52

everywhere.. cornea

Question 53

collagen synthesis reagents?

Answer 53

a-ketoglutarate, vit C, oxygen, iron, prolyl hydroxylase (hydroxylation)

Question 54

what cross links in collagen?

Answer 54

proline (q3 amino acid)

Question 55

scar strength compared to original tissue?

Answer 55

80% @ 8 wks

Question 56

maximum collagen amount (uncrosslinked) at what time?

Answer 56

3 wks

Question 57

d-penicillamine on cross linking?

Answer 57

inhibits collagen cross linking

Question 58

transcutaneous oxygen measurement necessary for wound healing?

Answer 58

25+ mm Hg

Question 59

how does DM affect wound healing?

Answer 59

hyperglycemia causes poor leukocyte chemotaxis

Question 60

what vitamin couteracts effects of steroids on wound healing?

Answer 60

vitamin A 25000 IU qd

Question 61

osteogenesis imperfecta?

Answer 61

type I collagen defect

Question 62

ehlers danlos syndrome?

Answer 62

collagen disorders

Question 63

marfans

Answer 63

fibrillin defect (CT protein)

Question 64

epidermolysis bullosa?

Answer 64

excessive fibroblasts tx: phenytoin

Question 65

pyoderma gangrenosum

Answer 65

wound healing issue; treat with STEROIDS

Question 66

DFI?

Answer 66

diabetic foot infection. mostly Charcot's joint (2nd MTP joint)

Question 67

when to stop chemotherapy if anticipating wound healing?

Answer 67

14 days

Question 68

how does cartilage get blood flow?

Answer 68

it doesn't... diffusion only for nutrients and oxygen

Question 69

alpha granules in plt - contents?

Answer 69

plt factor 4, factor V and VIII (coagulation factors) vWF fibrinogen B-thrombomodulin (binds thrombin) PDGF TGF-B (modulates above responses)

Question 70

dense granules in plt - contents?

Answer 70

adenosine, serotonin, calcium

Question 71

plt aggregation factors?

Answer 71

TXA2, thrombin, plt factor 4

Question 72

rate of wound infection

Answer 72

clean: 1-2% infection clean contaminated: 5-10% contaminated 15-30% dirty >30%

Question 73

treat venous leg ulcers?

Answer 73

Unna boot (elastic wrap) > pentoxifylline or aspirin