Diabetes

Question 1

Hyperglycaemia

Answer 1

• Raised blood sugar levels
• Common effect of uncontrolled diabetes
• Can lead to serious damage to nerves and blood vessels

Question 2

Type 1 diabetes:

Answer 2

• Beta-cells in the islets of Langerhans can not produce insulin
• Cause is not known –> can not be cured or prevented
• Can be effect of an autoimmune response where the body’s own immune system attacks the Beta-cells
• Treat symptoms
• Conditions begins in childhood and symptoms develop quickly

Question 3

Type 2 diabetes:

Answer 3

• Cannot effectively use insulin and control their blood sugar levels –> not enough insulin produced or body cells do not respond properly to insulin
• Often because glycoprotein insulin receptor on the cell membrane does not work properly –> cells lose their responsiveness to insulin and do not take up enough glucose

Question 4

What causes type 2 diabetes:

Answer 4

• Excess body weight
• Physical inactivity
• Habitual, excessive overeating of refined carbohydrates

Question 5

Difference between type 1 and 2 diabetes?

Answer 5

• Type 2 develops more slowly and is less severe
• Type 2 is only diagnosed after complications have already arisen.
• Risk of type 2 increases with age, type 1 doesn’t
• Used to only occur in adults, while type 1 in both. Now type 2 seen in both

Question 6

Control of type 1 diabetes:

Answer 6

Insulin-dependent –> Regular injections of insulin
- Regularly test blood glucose level –> pricking finger.
- Drop of blood analysed by machine which tells blood sugar conc
- Based on conc, patients can work out how much insulin they need to inject
- Blood glucose conc drops quickly

Question 7

What happens if someone with type 1 diabetes injects themself with too much insulin?

Answer 7

• Hypoglycemia (very low blood glucose concentrations) –> unconsciousness

Question 8

What happens if someone with type 1 diabetes injects themself with too little insulin?

Answer 8

• Hyperglycaemia (too much blood glucose) –> unconsciousness and death if left untreated.

Question 9

Control of type 2 diabetes:

Answer 9

• Regulate person’s carbohydrate intake through their diet and matching this to their exercise levels
• Overweight people encouraged to lose weight
• In come cases, diet and exercise are not enough to control blood glucose levels and drugs also neede
• Drugs stimulate insulin production, slow rate at which body absorbs glucose from small intestine, ultimately insulin injections

Question 10

Medically produced insulin: old

Answer 10

• From pancreas of cows and pigs slaughtered for food
• But this could cause allergic reactions

Question 11

Medically produced insulin: modern

Answer 11

1955 –> structure of human insulin identified and made by genetically modified bacteria

Question 12

Advantages of modern medically produced insulin:

Answer 12

• Human insulin produced in a pure form -> less likely to cause allergic reactions
• Insulin can be produced in much higher quantities
• Production costs much cheaper
• People’s concerns over using animal products in humans (religious or ethical) overcome

Question 13

Stem cell potential:

Answer 13

• Replace faulty beta cells
• Limited number of cells in the islet can restore insulin production (stem cells)
• Totipotent stem cells have potential to grow into any of the body’s cell types.
• study signals required to promote differentiation into beta cells (directly in patients body or in lab)

Question 14

Stem cells advantages over current therapies:

Answer 14

• Donor availability would not be an issue –> stem cells support unlimited source of new beta cells
• Reduced likelihood of rejection problems as embryonic stem cells generally not rejected by body. Stem cells can also be made by somatic cell nuclear transfer (SCNT)
• People no longer have to inject themselves with insulin

Question 15

Ethics around stem cells:

Answer 15

For:
- One embryo used for multiple treatments
- Could use umbilical stem cells
- ‘spare’ embryos

Against:
- Human life

Question 16

Pancreas transplant:

Answer 16

• Highly successful –> stop type 1 diabetes
• Demand too high
• Risk of transplant can be greater than risk of having type 1 diabetes
• Immunosuppressant drugs required -> susceptible to infection