B6- Preventing And Treating Disease Flashcards
Different way if treating and preventing disease
Disinfecting surfaces
Handwashing
Antiseptics-chemicals that kill pathogens on skin
Isolating infected individuals
Vaccines
Painkillers-reduce pain
Antivirals-drug used to viruses
Antibiotics- specific antibiotics are used to treat specific pathogens,antibiotics can kill bacteria but not viruses
Vaccination
Involves injecting small amounts of dead or weakened pathogens into the body. This stimulates white blood cells to produce antibodies.
When a pathogen enters the body,the lymphocyte with the correct antibodies is selected.
The lymphocyte produces a lot of antibodies to neutralise the pathogen by binding to antigens
The selected lymphocyte remains a “memory cell” ready to release more antibodies if repeat infection occurs.
The antibodies upon secondary infection are produced much quickly,so pathogen can be destroyed and symptoms are not felt.
Herd immunity
-following a vaccination, a person can become immune to specific disease
-this immunity gives the individual protection against the illness
-majority of population must be vaccinated against serious disease, which can reduce the chance of people coming into contact with specific pathogens,leading to herd immunity.
Antibiotics and painkillers defenition
Antiobiotics are medicines that kill bacterial pathogens inside the body,without damaging body cells.
Painkillers only treat the symptoms of the disease rather than the cause.
Antiobiotics
-can be taken as a pill,syrup or directly into bloodstream
-different antiobiotics are effective against different type of bacteria, so receiving correct one is important
- example is pencilin
Concern about antiobiotics
Bacteria is becoming resistant to Antiobiotics
-mutations can occur during reproduction resulting in certain bacteria no longer being killed by antibiotics
-when these bacteria are exposed to antibiotics,only the non-resitant one die
-the resistant bacteria survive and reproduce,meaning population of bacteria increases.
What is digitalis used for? Where does it come from?
One of several drugs extracted from foxgloves. It has been used since 18th century to strengthen heartbeat
What is aspirin used for? Where does it come from?
It is a painkiller that come from a compound found in the bark of willow trees. The anti-inflammatory and pain relieving properties were first recorded in 400bc. Relieves pain and inflammation
Pencilin
Fleming was growing bacteria on plates
He found mould on his culture plates,with clear rings around the mould indicating there was no longer bacteria there
He found that the mould was producing a substance called pencilin which killed bacteria
A good medicine is…
Effective-must cure the disease or prevent the disease
Safe-the drug must to be too toxic or have unacceptable side affects
Stable-you must be able to use the medicine under normal conditions and store it for some time
Successfully taken into and removed from body
Developing and testing new drugs
Clinical testing:
-it is first tested on healthy volunteers sith a low dose to ensure there are no harmful side affects
-the drugs are then tested on patients to find out most effective dosage
-to test efficiency patients are split into 2 groups Recieving the drug and other recieving placebo so the effect kf the new drug can be observed
Preclincial testing:
- The drug is tested on cells in the lab
- computer models may also be used to stimulate the metabolic pathways that may be taken by the drug
-efficacy and toxicity are tested at this stage
-whole organism testing
-efficacy,toxicity and dosage are tested at this stage
Antiobiotic resistance
Overused and antibiotic resistance has developed in many different types of bacterial species
-one of these mutations may give them resistance to antibiotics
1) a population of bacteria in gut. Some have antibiotic resistance
2) when exposed to an antibiotic,bacteria causing an illness, as well as healthy gut bacteria
3) with reduced competition for nutrients, antibiotic resistant bacteria multiply, forming a larger population that is difficult to control
Preventing resistant bacteria
- Doctors need to avoid the overuse of antibiotics, prescribing them only when needed-they may test the bacteria first to make sure that they prescribe the correct antiobiotic
-Antibiotics shouldn’t be used in non-serious infections that the immune system will “clear up”
-Antibiotics shouldn’t be used for viral infections - patients need to finish the whole course of antibiotics so that all the bacteria are killed and none are left to mutate to resistant strains
- antibiotics use should be reduced in industries such as agriculture
Reducing spread of resistant strains
-Good hygiene practices such as handwashing and use of hand sanitisers have reduced the rates of resistant strains if bacteria, such as MRSA
-isolation of infected patients to prevent the spread of resistant strains, in particular in surgical wards where MRSA can infect surgical wounds
What do all drugs need to be tested and trialled before they can be used in patients
Toxicity
Efficacy
Dose
Future medications
Vaccinations to different diseases
Antibiotics that have different action on the bacteria,so that bacteria are not resistant to them
Painkillers with fewer side affects
Antiviral drugs that don’t damage the boy tissues
Advantages and disadvantages of vaccination
Advantages:
-they have eradicated many diseases so far (eg smallpox) and reduced the occurrence of many (e.g rubella)
-epidemics (lots of cases in an area) can be prevented through herd immunity
DisAdvantages:
- They are not always effective in providing immunity
- bad reactions (such as fevers) can occur in response to vaccines (although very rare)
