B6- Preventing and treating disease Flashcards
Vaccine
An injection containing a dead or weakened pathogen
Process of vaccination in the body
- Vaccine with dead or weakened pathogen
- White cells produce antibodies, bind to dead pathogen’s antigen
- Person doesn’t feel ill as pathogen is dead
- Memory cells remain
Concentration of antibody after infections
Initial exposure, lymphocytes produce antibodies. Second exposure, memory cells quickly produce a large amount
Herd immunity
Large proportion of the population is immune to a disease, spread of the pathogen is reduced
Vaccines
Ad and dis
Ad- low chance of getting infectious disease, prevents epidemics, save money on treatment
Dis- possible adverse reactions or side effects, against some beliefs
Pain killers and examples
Relieve pain and symptoms but don’t kill pathogens eg. aspirin paracetamol, ibuprofen
Antibiotics and example
Kill bacteria but can’t be used on viral infections eg. penicillin, amoxicillin
What happened after antibiotics became widely available?
Why don’t antibiotics destroy viruses?
Number of deaths rapidly decreased
Viruses replicate inside cells, hard to damage virus without body cells
2 ways antibiotics work
- Stop bacteria from building cell walls
- Stop bacteria’s DNA replicating
Antibiotic resistance
Bacteria strains evolving so antibiotics no longer have an effect
3 ways to prevent resistant bacteria
1.Don’t take them for minor or viral infections
2.Finish antibiotic course
3. Use correct type of antibiotic for infection
3 drugs that came from plants and microorganisms
Where from?
Does what?
Aspirin- Willow tree bark, painkiller
Penicillin- Fungus mould, antibiotic
Digitalis- Foxgloves, strengthens heartbeat
Antibiotics
Discovered by?
First one?
How?
Alexander Fleming
Penicillin
Cultures of bacteria dies after contaminated by fungus, grew it after
Starting point for most drugs?
Why is it hard to find medicines?
What fruit has potential antibiotic properties
Chemicals extracted from a plant
Most kill human cells
Noni fruit (Costa Rica)
4 things a good medicine needs to be and what does it mean
Effective- prevent, cure disease or feel better
Safe- not toxic, little side effects
Stable-stored long time
Dosage- effective conc
3 things new drugs are tested for
Efficacy, toxicity, dosage
Pre-clinical drug stage
What tested?
Aim?
Cells/tissue
Level of toxicity at a cellular level
Animals
Efficacy and toxicity
Clinical phase 1 drug stage
What tested?
Aim?
Low dose given to small group of healthy volunteers
Tested for side effects
Clinical phase 2 drug stage
What tested?
Aim?
Small group of patients
Test for effectiveness
Clinical phase 3 drug stage
What tested?
Aim?
Larger group of patients
Confirm effectiveness and test for optimum dose
Placebo
A medicine that does not contain the active drug
Double blind trial
Definition?
Why is it helpful?
Neither the doctor nor patient know the medicine they have
Removes bias and makes results valid
Monoclonal antibodies
Large number of identical antibodies produced by cloned cells
How are monoclonal antibodies created
Lymphocytes that produce a specific antibody are isolated, then combined with tumour cells to form a hybridoma cell. They divide to produce clones, that are purified to produce monoclonal antibodies
Uses for monoclonal antibodies
1.Pregnancy tests
2. Treating disease
3. Diagnosing disease
4. Monitoring hormones
5. Research
How pregnancy tests work for a positive result
Pregnancy urine contains hCG, that binds with mobile antibodies, and they both bind to the first set of immobile antibodies changing colour. Excess mobile antibodies bind to the immobilised antibodies on the control strip that changes colour.
Monoclonal antibodies Ads and Dis
Ad- Healthy cells not affected, potential to be cheap, can treat a wide range of conditions
Dis- Hard to produce, expensive, created more side effects than expected
3 ways monoclonal antibodies treat cancer
1.Stimulate immune system to recognise, attack and destroy cancer cells
2.Stop cancer cell dividing
3.Carry drugs that directly stop division
