Session 5 - Chronic Inflammation and Wound Healing

Question 1

What is the length of chronic inflammation?

Answer 1

Days + Weeks + Months

Question 2

What are the histological appearance of acute inflammation?

Answer 2

Exudation of fluid and plasma proteins

Emigration of leukocytes

Question 3

What are the histological changes seen in chronic inflammation?

Answer 3

Infiltration of mononuclear cells

Tissue destruction + tissue repair

Question 4

What are the mononuclear cells seen in chronic inflammation?

Answer 4

Macrophages + Lymphcytes + Plasma cells

Question 5

What causes chronic-active inflammation?

Answer 5

Initial cause of inflammation has not been removed

Question 6

What is occurring during chronic-active?

Answer 6

Suppurative inflammation with chronic inflammatory changes

Question 7

What is a disease seen in cattle that can cause chronic-active inflammation?

Answer 7

Hardware disease

Question 8

What is the pathology of FIP?

Answer 8

Mutations occur in macrophages in Peyer’s patches of intestines + blood monocytes. Each cat will have its own variant.

Question 9

What gross changes do you see with FIP?

Answer 9

Multifocal, grey-tan, slightly raised pyogranulomas that follow vascular structures and tend to coat serosal surfaces

Question 10

How does the suppurative component of FIP occur?

Answer 10

Due to activated macrophages + monocytes that continue to release proinflammatory mediators

Question 11

What type of hypersensitivity occurs with FIP?

Answer 11

Type III

Question 12

What happens once type III reaction occurs in FIP?

Answer 12

Complement will further promote neutrophil chemotaxis

Question 13

What type of inflammation does fibrinous inflammation occur?

Answer 13

Acute

Question 14

Why does fibrinous inflammation occur with acute inflammation?

Answer 14

Due to increased vascular permeability, fibrinogen is released from vessels and makes a disorganized scaffold

Question 15

What does the fibrinous inflammation provide scaffolding for?

Answer 15

Subsequent fibrosis

Question 16

What is fibrosis?

Answer 16

Organized collagen fills areas of tissue damage

Question 17

What is the major characteristic of granulomatous inflammation?

Answer 17

Epithelioid macrophages

Question 18

What is granulomatous inflammation a subset of?

Answer 18

Chronic inflammation

Question 19

What other cell types, beside epitheliod macrophages, occur in granulomatous inflammation?

Answer 19

Lymphocytes + Multinucleated giant cells

Question 20

Where does fibrosis occur in granulomatous inflammation?

Answer 20

Within and around granuloma

Question 21

Where are epithelioid macrophages found in a granulomatous inflammation?

Answer 21

Cluster in a circle around the causative agent

Question 22

Where are lymphocytes found in a granulomatous lesion? What do they do?

Answer 22

Circling the macrophages. Secrete cytokines.

Question 23

What do Epithelioid macrophages look like histologically?

Answer 23

Large cells with abundant pale staining cytoplasm

Flat, sheet like appearance

Question 24

What are giant cells?

Answer 24

20+ activated macrophages that can fuse together

Question 25

What do giant cells look like histologically?

Answer 25

Large mass of cytoplasm + multiple nuclei

Question 26

What are the common components of chronic inflammation that can lead to neoplasia?

Answer 26

Increase cell division = prolonged attempts to heal | Reduced immune surveillance allowing proliferation of cells

Question 27

How is it thought that feline post-vaccinal fibrosarcoma occur?

Answer 27

Persistent injection site inflammation + genetic predisposition Neoplastic transformation of fibroblast + other CT cell type

Question 28

What is the median age of feline post-vaccinal fibrosarcoma?

Answer 28

8 years

Question 29

What first is seen (at a young age) that can be a sign post-vaccinal fibrosarcoma will occur?

Answer 29

Subcutaneous location near previous vaccine site

Question 30

What are the stages of wound healing?

Answer 30

Hemostasis Acute inflammation Proliferation Remodeling

Question 31

What is the general mechanism occurring during proliferation?

Answer 31

Granulation

Question 32

What general mechanism is occurring during remodeling?

Answer 32

Maturation + Contraction

Question 33

What occurs during hemostasis during wound healing?

Answer 33

Occurs immediately | Vasospasm followed by relaxation + accumulation of platelets

Question 34

What type of inflammation occurs with wound healing?

Answer 34

Acute

Question 35

What is occurring during the proliferation phase of wound healing?

Answer 35

Wound is rebuilt with granulation tissue | Epithelial cells resurface the wound

Question 36

What is it called when epithelial cells resurface wound?

Answer 36

Epithelialization

Question 37

What is occurring during granulation?

Answer 37

Collagen and new blood vessels occur throughout the wound via angiogenesis

Question 38

Why does angiogenesis need to occur during wound healing?

Answer 38

The are that is healing needs adequate oxygen and nutrients

Question 39

What phase does MMP play a role in?

Answer 39

Proliferation phase

Question 40

What does MMP do?

Answer 40

Damaged tissue matrix is degraded by MMP so that it can be phagocytosis by macrophages

Question 41

What occurs during the maturation phase of wound healing?

Answer 41

Remodeling of collagen + switch from synthesis of Type III to I Collagen synthesis stops Blood vessels regress and decrease

Question 42

What are the four major cell types in granulation tissue?

Answer 42

Macrophages + Fibroblasts + Endothelial cells + Epithelial cells

Question 43

What growth factors are related to macrophages?

Answer 43

Lymphokines C3b TGF-B Fibronectin

Question 44

What growth factors are related to fibroblasts?

Answer 44

``` PDGF + MDGF + EDGF IL - 1 Insulin ILGF + FGF + TGF-B somatomedins Lymphokines ```

Question 45

What growth factors are related to endothelial cells?

Answer 45

MDGF + PDGF Lymphokines Epidemral angiogenic factor

Question 46

What growth factors are related to epithelial cells?

Answer 46

EGF | PDGF

Question 47

What is the most critical growth factor in wound healing?

Answer 47

TGF-B

Question 48

What is TGF-B secreted by?

Answer 48

Fibroblasts + Keratinocytes + Macrophages + Platelets

Question 49

What does TGF-B work on?

Answer 49

Keratinocytes + Fibroblasts + Endothelial cells + Monocytes

Question 50

What does TGF-B do to fibroblasts?

Answer 50

Proliferation + Migration

Question 51

What does TGF-B do to macrophages?

Answer 51

Promotes chemotaxis

Question 52

What does TGF-B do to fibroblasts?

Answer 52

Stimulate production of ECM proteins + Collagen

Question 53

What can occur with granulation tissue that is NOT helping healing?

Answer 53

Can overgrow + inhibit healing | aka proud flesh

Question 54

What cell type is responsible for wound contraction?

Answer 54

Myofibroblasts

Question 55

What are the basic causes of chronic inflammation?

Answer 55

Persistent infections by some microorganisms Prolonged toxic exposures Autoimmune reactions Persistent injury