Final exam

Question 1

MCSF function

Answer 1

Promotes monocyte differentiation into macrophage

Question 2

Why don’t macrophages undergo diapedesis?

Answer 2

Because they reside extravascular

Question 3

Macrophage size

Answer 3

80-100 microns

Question 4

Motility definition

Answer 4

Ability to move spontaneously by expanding energy

Question 5

Define phagocytes

Answer 5

Cells that protect a body by ingesting foreign objects

Question 6

Clonal selection theory

Answer 6

Clonal selection theory explains how adaptive immunity works, stating that lymphocytes specific to an antigen are selectively activated and proliferate upon encountering that antigen.

Question 7

2 subtypes of acquired immunity

Answer 7

Humoral
Cell mediated

Question 8

(T/F) NK cells require stressed cells to display MHC or Ab

Answer 8

False

Question 9

TH1 is for humoral/cell mediated

Answer 9

Cell mediated

Question 10

TH2 is for humoral/cell mediated

Answer 10

Humoral immunity

Question 11

MHC classes

Answer 11

MHC only displays peptides

Class 1: Intracellular source
Class 2: Extracellular source

Question 12

Two ways antibody contribute to immunity

Answer 12

1. Activation of complement system
   - leads to pathogen lysis
2. Opsonization
   - leads to phagocytosis

Question 13

4 main steps in wound healing

Answer 13

1. Injury
   - few mins
2. Coagulation
   - few hours
3. Inflammation
   - few hours
4. Repair and remodeling
   - weeks ~ months

Question 14

Describe the difference between angiogenesis and vasculogenesis

Answer 14

Angiogenesis:
* Formation of new blood vessels from pre-existing ones.
* Occurs during wound healing, tumor growth, and tissue repair.
* Involves sprouting, proliferation, migration, and remodeling of endothelial cells.

Vasculogenesis:
* De novo formation of blood vessels from precursor cells.
* Occurs during embryonic development.
* Involves differentiation of angioblasts into endothelial cells and their assembly into primitive vascular structures.

Question 15

Granulation tissue

Answer 15

• type of connective tissue
• scar tissue in early wound healing
• subset of fibrosis
• highly vascular, red, bumpy tissue, often moist, bleeds easily

Question 16

When does remodeling phase begin

Answer 16

When production and degradation of fibrosis collagen is equal

Question 17

What happens during remodeling phase

Answer 17

Disorganized collagen is rearranged and cross-linked in the direction of load bearing axis (tension or compression)

Question 18

Why is blood important during remodeling phase

Answer 18

They deliver nutrients and oxygen (angiogenesis!)

Question 19

Describe the timing aspects of wound healing

Answer 19

1. Blood clotting (immediate)
2. Clot break down (1-2 days)
3. Appearance of granulation tissue with angiogenesis (3-5 days)
4. Proliferative/repair phase (several weeks)
5. Remodeling phase (several years)

Question 20

What can arrest wound healing process in the inflammatory stage?

How does this do so?

Answer 20

Chronic inflammation

• This can lead to impaired matrix formation
• Inadequate or inactive GFs
• Mis-regulated enzymes

Question 21

How does infection lead to risk of chronic non-healing?

Answer 21

Prolonged inflammatory phase reduces ability of the tissue to proliferate

Question 22

Surface analytical techniques generate information about the (3 things)

Answer 22

• topography
• chemical composition
• interaction

Question 23

Should we include efficacy with safety?

Answer 23

No! Lychees can be effective, but not safe!

Question 24

What is meant by safety?

Answer 24

Non-injurious
Non-toxic

Question 25

Are biocompatibility and bioactivity the same

Answer 25

No. Bioactivity refers to eliciting a specific response at the surface of the material. For example, contact lenses are not bioactive. However, all materials that interacts with the body must be biocompatible.

Question 26

Most pre-clinical testing is done on _____ instead of the ______

Answer 26

Material, whole device

Question 27

3 classes of medical devices

Answer 27

Class 1 - does not sustain human life, been around a while - most exempt from 510k clearance Class 2 - most require 510k clearance Class 3 - supports or sustains life - nearly all require premarket approval (PMA)

Question 28

What is 510k

Answer 28

Premarket submission made to FDA that the medical device is substantially equivalent to the one that exists in the market (=predicate device), that does not require PMA

Question 29

Sequence of tests

Answer 29

1. In vitro 2. Ex vivo 3. Animal models (sheeps, pigs) 4. Clinical trials

Question 30

Purpose of in vitro testing

Answer 30

Used to screen materials and devices for BIOCOMPATIBILITY

Question 31

Cost for in vitro testing

Answer 31

100s~ 1000s

Question 32

Cost for in vitro lab facility

Answer 32

50k ~ 100k

Question 33

Which state of testing involves relatively fast processing of a large number of materials and prototypes?

Answer 33

In vitro testing

Question 34

Limitations of in vitro testing

Answer 34

No understanding of efficacy (just know the material does not kill cells) No understanding of systemic toxicity, only at the individual cell level

Question 35

Purpose of in vitro study

Answer 35

Used to screen materials and devices for biocompatibility

Question 36

What is the size progression of animal models

Answer 36

Small -> large Generally, larger animals are mroe expensive.

Question 37

What does every school + industry have that evaluates animal care and use program?

Answer 37

IACUC

Question 38

Things to consider when using animal mdoels

Answer 38

* must choose appropriate species + justify it * carefully plan experiments using smallest number of animals that will use statistical result * animal welfare act of 1966 - addresses care + use of lab animals

Question 39

5 essential features of clinical trials

Answer 39

1. uses defined inclusion/exclusion rules - age/weight requirements 2. use of control groups 3. subjects assigned to groups randomly 4. double-blinded studies 5. adequate size of experimental/control groups

Question 40

Cost of non-human primates

Answer 40

millions