Insulitis

Question 1

Insulitis

Answer 1

Infiltration of lymphocytes in pancreas
CD8+s kill beta cells with granzymes and perforin
Response increases as insulin concentration decreases
CD20+ B cells cause insulin desensitivity

Question 2

Islet transplants

Answer 2

Stop severe hypos
6-10 year benefit
Need immunosuppressants
Require low level insulin injections
Non invasive
Needs donors

Question 3

Induce pluripotent stem cells

Answer 3

Ulimited supply, easy to obtain
Less ethical issues, adults not embryos
Difficult to do
Personalised so no immunosuppressants
Carcinogenic (teratomas)

Question 4

What factors reprogramme skin cells

Answer 4

OCT4, SOX2, KIF4, C-MYC

Question 5

Embryonic stem cells

Answer 5

Inner cell mass of blastocyst
Ethical issues
Autoimmune responses, teratomas
Potentially unlimited supply - self-renewal
Multidirectional differentiation

Question 6

What are the two routes for transdifferentiation?

Answer 6

Convert liver cells to beta cells

Covert alpha to beta cell

Question 7

Liver to beta cell transdifferentiation

Answer 7

Inject mouse with virus and TFs

Produce insulin positive cells

Question 8

Alpha to beta cell transdifferentiation

Answer 8

GABA induces alpha cell mediated beta-like cell neogenesis

Question 9

Pancreatic stem cells

Answer 9

Partially differentiated

Difficult to isolate

Question 10

Hepatic stem cells

Answer 10

Autologous source

Difficult to produce enough

Question 11

Spermatogonial stem cells

Answer 11

Potentially unlimited supply
No ethical issues, very plastic
No long term studies

Question 12

Mesenchymal stem cells

Answer 12

Unlimited supply
Multidirectional differentiation
Autologous
Temporary

Question 13

Beta cell regeneration

Answer 13

Enhanced replication of existing beta cells
Form new cells from cells not expressing insulin
Transdifferentiation or neogenesis (from progenitors)

Question 14

Smart insulin features

Answer 14

Inactive when glucose is normal/low
Rapidly activated when glucose rises
Rapidly inactivated when glucose falls

Question 15

Microarray patches

Answer 15

Insulin in polymer that dissociates in hypoxic environments (high glucose) releasing insulin

Question 16

Inhaler

Answer 16

Variable absorption in lungs and local irritation
Afrezza - rapid absorption
Exubera - stabilised so bioavaiable powder

Question 17

Pumps

Answer 17

Insulin via cannula - infection risk
Bolus at meals
More stable - fewer highs and lows
Cannula change every 2-3 days
Fewer risks e.g. exercising
Constantly attached
Short acting insulin - needs regular checking

Question 18

Continuous glucose monitoring

Answer 18

Glucotrack - earlobe
Smart tattoos
Flash glucose monitoring (scan button)
Uses interstitial fluid, not blood

Question 19

Interstitial fluid

Answer 19

15 minutes behind
Test any time
Non-invasive
Expensive
Less accurate

Question 20

Artificial pancreas - three features

Answer 20

CGM under skin
Control algorithm device (algorithm calculates dose)
Insulin pump (automatically administers via cannula)