Preventing and Treating Disease

Question 1

What is involved in an immune response?

Answer 1

Phagocytes engulf and destroy pathogens; lymphocytes produce antibodies and antitoxins, and recognise antigens produces

Question 2

Vaccination

Answer 2

1. Vaccines contain dead/inactive pathogens for a specific disease
2. Vaccine is usually injected into the body
3. Antigens in the vaccine stimulate lympocytes to produce the correct antibody
4. Memory cells remain in the body so that when an infection occurs white blood cells can be produced rapidly
5. The body responds much more quickly to produce antibodies so you do not suffer from the disease
6. The antibodies destroy the antigen without the risk of getting the disease

Question 3

Immune response graph - why is secondary response quicker, more antibodies, lasting longer?

Answer 3

Because the 1st response is slow, it cannot prevent disease - a vaccine mimics the primary response without the risk of getting ill
In the 2nd response, the pathogen is detected, attacked and destroyed before symptoms appear

Question 4

Herd immunity

Answer 4

If enough of the population is vaccinated, it becomes very difficult for the pathogen to be transmitted so essentially the population is protected

Question 5

What causes Zone of Inhibition?

Answer 5

Antibiotic diffusing from disk out to agar, killing bacteria

Question 6

Drug

Answer 6

Substance that alters the way in which your body works - could affect mind, body or both

Question 7

Medicine

Answer 7

Drug or other preparation for the treatment or prevention of disease

Question 8

Cure vs treatment

Answer 8

Treatments relieve symptoms, cures make disease go away e.g. penicillin vs paracetamol

Question 9

Painkillers vs antibiotics

Answer 9

Used to relieve symptoms, do not kill pathogens causing disease so not a cure

Question 10

Antibiotics vs painkillers

Answer 10

Kill bacteria and therefore cure the disease

Question 11

How do antibiotics work?

Answer 11

Damages bacterial cells but do not harm human cells - e.g. penicillin acts on the cell walls of bacteria

Question 12

Viruses and antibiotics

Answer 12

Antibiotics do not kill viruses; viruses live and reproduce inside human cells so difficult to develop drugs which kill viruses but don’t damage human cells

Question 13

Antibiotic resistance

Answer 13

Some bacteria develop resistance to antibiotics - they have a natural mutation which means they are not affected by the antibiotic. Mutations happen by chance and produce new strains of bacteria by natural selection

Question 14

Susceptible Bacteria

Answer 14

In any population of bacteria, some are stronger and some are weaker. More susceptible bacteria are easier to kill with antibiotics and vice versa. Less susceptible bacteria can be killed eventually dw kids

Question 15

How to prevent antibiotic resistance

Answer 15

Take the full course

Question 16

Resistance storyboard

Answer 16

1. Non resistant bacteria exist
2. Bacteria multiply by the millions - a few of these bacteria will mutate
3. Some mutations make the bacterium drug resistant and in the presence of drugs only these will survive
4. Drug resistant bacteria multiply and thrive

Question 17

Antibiotic

Answer 17

Medicine or a chemical which can kill bacteria without harming our cells

Question 18

Features of a good medicine

Answer 18

Effective (must prevent/cure disease)
Safe (not toxic and have no unacceptable side effects)
Stable (must be able to use the drug under normal conditions and store it for some time)
Excreted safely from the body (after reaching the target area the drug must be broken down safely and excreted)

Question 19

Drug development

Answer 19

Researchers target a new disease and make lots of possible new drugs

Question 20

Preclinical trials drug development

Answer 20

Drugs are tested on cells in the lab to test their toxicity and efficacy (are they toxic and do they do their job)

Question 21

After preclinical trails

Answer 21

Drugs are tested on animals in the lab to see how they work in a whole system

Question 22

Phase I Clinical Trial

Answer 22

Drug tested on healthy volunteers - low doses given to check for side effects and then to check for the correct dosage

Question 23

Phase II

Answer 23

Drugs tested on people who suffer from teh disease and in increasingly large numbers to test dosages and ensure there are no side effects

Question 24

Phase III

Answer 24

Test how drugs compare to current ones as there is no point in developing drugs further if it isnt better than existing ones

Question 25

After Phase III

Answer 25

Drug can be granted a license and can be prescribed

Question 26

Phase IV

Answer 26

Continue after the drug has been approved and is being used - it is important to monitor long term effects

Question 27

Placebo

Answer 27

Looks the same but odes not contain the active drug

Question 28

Double blind trials

Answer 28

Patient s with the target disease are given either a placebo or the active drug and their health is monitored carefully (sometimes the placebo contains another drug so the patient is not deprived of treatment) Neither doctor nor patient knows who got what until after the trial

Question 29

Why bother double blind

Answer 29

Avoids bias from patient and doctor

Question 30

Antibodies

Answer 30

Proteins that are produced to target a specific cell or chemical in the body

Question 31

Mice lympocyted

Answer 31

• produce antibodies to the antigen but cells wioll die quickly

Question 32

Cancer cells

Answer 32

Divide quickly and don’t die

Question 33

Hybridoma

Answer 33

Mice lympocytes x tumour cells - divide quickly, don’t die, produce antibodies

Question 34

What is MRSA

Answer 34

It is an infection of the skin
The bacterium MRSA has become resistant to number of antibiotics due to natural
selection.
It prevents wounds from healing and is a particular problem in hospitals.
It can be spread easily from patient to patient by direct contact

Question 35

Minimising the problem of MRSA

Answer 35

Use antibiotics only when necessary
Treat specific pathogen with specific antibiotics
Medical staff to wash hands between patients
Visitors to wash hands entering and leaving
Patients with MRSA to be looked after in isolation

Question 36

What can you do with hybridoma cells

Answer 36

They can multiply to make large nos of identical cells that can all produce the specific antibody - ab can then be collected and purified

Question 37

Monoclonal use diagnosis

Answer 37

Monoclonal antibodies are made to bind to specific antigens found on pathogens, or on blood clots or on cancer cells. The
monoclonal antibodies may also carry markers that make it easy
for doctors to see where they have built up. This allows doctors
to detect problems, eg prostate cancer blood test uses
monoclonal antibodies.

Question 38

Pregnancy Tests Monoclonal use

Answer 38

Monoclonal antibodies bind to the hormone hCG (human
chorionic gonadotropin) that is made in the early stages of
pregnancy. Tiny amounts of the hormone are passed out of the
body in the urine. Monoclonal antibodies in the pregnancy test
bind to the hormone if it is present, and this is used to produce a
colour change that signals a positive result.

Question 39

Measuring and monitoring monoclonal

Answer 39

Used to monitor the levels of hormones or other chemicals in
hospitals.eg screening donated blood for HIV, detecting illegal
drugs in athletes, detecting syphilis.

Question 40

Research monoclonal

Answer 40

To locate or identify specific molecules in a cell or tissue.
Scientists link the monoclonal antibody to a fluorescent dye, this
can be detected under a microscope.

Question 41

How can monoclonal antibodies be used to treat cancer

Answer 41

1. recognise, attck and destory cancer cells
2. Using MAB to block receptors on the surface of cancer cells to stop them growing
   and dividing.
3. Can be used to carry toxic drugs, radioactive substances or drugs that stop cells
   dividing to the cancer cells directly, they do not harm other cells.

Question 42

Drugs from plants

Answer 42

Aspirin from willow bark
Pencillin from penicillum fungus
Digitalis from foxgloves

Question 43

Monoclonal Ab Pros

Answer 43

• bind to specific antigens
• healthy cells are not affected unlike in conventional therapy
• can be used to treat a range of diseases because it is specific

Question 44

Monoclonal Ab cons

Answer 44

Expensive to develop.
More side effects than expected.
The mouse antibodies used can trigger
an immune response in humans although
newer technology is using hybrid cells so there are fewer side effects.
Side effects need treatment.
Producing the correct monoclonal
antibody and attaching the drug can be difficult.