(Module 6)Preventing and treating disease

Question 1

How do vaccines work?

Answer 1

Every pathogen gets a unique antigen, even when weak or ill
A vaccine is an injection of a weak, dead or dying pathogen.
The body will naturally battle it like it does any other pathogen, which will take time, but the injected version of the pathogen is too weak to do any damage
Once dealt with, the white blood cells will recognise/remember the antigens of the pathogen
So if a real live version of the pathogen enters the body, it can be rapidly dealt with

Example : MMR (Measles, mumps and rubella)

Question 2

What is herd immunity?

Answer 2

This is where enough of the population are immune to a disease that they become resistant, and the disease it weakened and dies out

Question 3

What are the problems with many drugs/pain killers?

Answer 3

They relieve symptoms (e.g a headache), but do not speed up the process of healing any way. As well, they will be ineffective against viruses in the body at the time

Most do not kill pathogens, you have to wait for your immune system to overcome the disease

Question 4

In short, what are the benefits of many antibiotics and what do they do?

Answer 4

They are medicines which are effective at destroying communicable diseases. They first became widespread in the 1940’s, and were seen as wonder drugs

They destroy bacterial cells effectively. They do this without damaging your own cells, and only kill harmful bacterial cells

Enter the body by pill, syrup or may directly be entered into the bloodstream
Some kill many bacterial cells. Some target a few. The right antibiotic must be used for the right bacteria

Question 5

Problems with antibiotics

Answer 5

• They cannot target viral diseases (viruses). This is because viruses grow an reproduce in cells, and so are hard to target without damaging the cell
• More and more bacteria are becoming more resistant to antibiotics which once stopped them. Unless new antibiotics are found, many will die in the future from diseases we could cure today

Question 6

Examples of drugs from plants

Answer 6

Digitalis & Digoxin: A drug extracted from foxgloves
They help to strengthen the heart beat. Although there are many modern drugs to deal with this, doctors still use digitalis for older patient

Aspirin: origins from a compound found in the bark of a willow tree
First Discovered in 400BC, but mostly used in 1897
Relieves pain and inflation, and has little side effects
Commonly used to treat a wide range of health problems

Question 7

Drugs from microorganisms - discovering penicillin

Answer 7

In 1928, Alexander Fleming had been growing bacteria, but most had mould growing over it as he was careless
However, he noticed on spot where there was no mould. Something was killing the bacteria. He called it penicillin

He was unsuccessful, but later on Ernst Chain and Howard Florey decided to create penicillin 10 years later.
They tested on a man dying of blood infection. He survived whilst there was penicillin.
The two worked with US company Pfizer to mass produce it. It was used in WW2, as it was produced on a mass scale

Question 8

Medicines for the future

Answer 8

Example: the noni fruit
Used in Costa Rica, it is a traditional medicine used to treat infections and non-communicable disease. It has also been used for food and drink as well for years, and is seen as safe
It has antibiotic properties, but further research is neededt

Question 9

Can soil provide medicines in the future?

Answer 9

It could as many microorganisms are found in the soil, and just need to be tested. One has been found which has been successful so far on mice

Question 10

What does a good medicine need to be?

Answer 10

Effective - must prevent or cure a disease, or make you feel better
Safe - must not be too toxic (poisonous) or have unacceptable side affects
Stable - must be able to store for a while and usable under normal conditions
Successfully taken in and removed from the body - must reach its target and cleared from the system once done

Question 11

What are the costs to create a new medicine?

Answer 11

12 years and £1700 million

Question 12

What is preclinical testing?

Answer 12

This is where a new drug/chemical is tested in a laboratory on cells, tissues and live animals

Question 13

What happens in preclinical testing?

Answer 13

A disease is targeted
Researches create a range of drugs
They are treated in a laboratory to see if they are toxic and if they do their job efficiently. Tested on cells, tissues and whole organs

Those that make it are tested on live animal to see their effect on a whole organism
Also to see possible dosages and side effects

Question 14

What is clinical treatment?

Answer 14

Where the new drugs are used on healthy or ill patients in a clinic

Question 15

What happens in clinical treatments?

Answer 15

First, small doses are used on healthy patients and volunteers to check side effects
If safe, small amounts are used on a small amount of patients to see if the drug treats the disease
If found to be safe and effective, bigger clinical trials are used to check for the best dosage

If found to be safe, it is licensed and made available, whilst also being monitored for as long it is used

Question 16

Testing on drugs summarised

Answer 16

Preclinical:
Tested on cells, tissues and whole organisms
Then tested on animals

Clinical:
Tested on volunteers
Then tested on small number of patients
Then bigger tests occur
If all good, licensed

Question 17

What are double clinical trials?

Answer 17

To check for placebo affect

Some patients are given the drug, some something else
Nor the doctor nor the patient knows
The patients health is carefully monitored

Question 18

How are the drug companies checked for the truth?

Answer 18

Written reports are monitored by non-related doctors and health companies

Example: the NICE (National health institute for excellent health care)
Check drugs and monitor which ones the NHS should use