b6

• what does the immune systme do to the pathogen?

  if a pathogen enters the body the immune system tries to destroy the pathogen
• what is in a vaccine?

  a dead pathogen is injected into your body. the vaccine works in the same way as an infection. antigens can trigger an immune response. it can take many days for a lymphocyte making complementary anitbodies to be activated
• who is Edward Jenner?

  Edward Jenner used cow pox (vaccine) to treat small pox
• what is herd immunity?

  when enough people are vaccinated, the chnace of the disease spreading to an unvaccinated person is much lower
• what are antibiotics?

  a substance that helps a bacterial infection

  they kill bacteria in the body
• what are antiseptics?

  they kill microorganisms in the environment
• what is immunisation?

  the process of making a person immune or resistant to a particular disease, typically by administering a vaccine.
• what drug is from microorganism? who discovered it?

  penicillin

  Alexander Fleming
• how was penicillin formed?

  penicillin was discovered almost by accident. returning from holiday, Fleming removed the tops from some old petri dishes and notices that the bacteria he had grown were being killed by a mould - penicillin
• what does penicillin do?

  -penicillin kills bacterial pathogens while they are inside your body

  -they damage bacterial cells without damaging the body cells

  -millions of lives ave been saved

  -can be taken orally (mouth) or intravenously (needle)

  -some have a wide spectrum, some are very specific
• what are the drugs from plants?

  -traditional medicines are extracted from plants

  -digitalis & digoxin extracted from plants:

  -strengthen heartbeat

  -poisonous in large amounts

  -used since 18th century

  -aspirin originates from a compount in th ebark of willow trees

  -anti-inflammatory and pain-relieving

  -first used in 400BC

  -acetyl salicylic acid - synthetic aspirin (fewer side-effects) 1897
• what is drug is made from foxgloves? what does it do?

  digitalis is made from foxgloves

  they help strengthen the heartbeat
• what drug is made from willow bark? what does it do?

  aspirin (acetylsalicylic acid) is made from willow bark

  they are a painkiller, fever and inflammation
• how are monoclonal antibodies made?

  -monoclonal antibodies are antibodes that are made by identical immune cells, these identical immune cells are clones of the parent cell

  -antibodies are Y shaped proteins made by lymphocytes

  -the antibodies are specific to one building site on one protein antigen and so are able to target a specific chemical or specific cells in the body

  -they are produced by stimulating mouse lymphocytes to make a particular antibody by exposing them to an antigen
• advantages of monclonal antibodies

  -they only bind to specific molecules on diseased or damaged cell - tey do not affect healthy cells

  -highly specific so can be produced to treat a range of conditions

  -hoped to be a cheaper procedure, and a tred and tested method of treating conditions
• disadvantages of monclonal antibodies

  -caused more side effects than first expected, the use of mice antibodies caused complications. now humanised antibodies are being developed

  -it is an expensive process at the moment

  -producig specific monoclnal antibodies is proving to be more dfficult than expected
• what are the uses of monoclonal antibodies?

  -pregnancy test

  -diagnosis of disease

  -measuring & montioring

  -research

  -treating disease
• monoclonal antibodies in pregnancy tests

  the monoclonal antibodies are specific to a hormone produced in pregnancy, Human Chorionic Gonadotropin (HCG). they wll bind to the hormone if present and produce a colour change
• the different parts of a pregnancy test

  result window - non-mobile (immobilised) HCG - specific antibodies are found here

  sample pad - this part is dipped in urine

  control window - non-mobile (immobilised) antibodies complementory to the reaction zone antibodies

  reaction zone - HCG - specific antibodies are here. they are mobile and contain a blue dye
• what should a good medicine be?

  effective - it must prevent or cure a disease or at least make you feel better

  safe - the drug must not be too toxic (poisonous) or have unacceptable side effects for the patient

  stable - you must be able to use the medcine under normal conditions and store it for some time

  successfully taken into and removed from your body - it must reach its target and be cleared from your system once it has done its work
• what are the 3 stages of drug development?

  -preclinical testing

  -clinical trails (humans & animals)

  -double-blind trials
• what happens at the preclinical testing?

  -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
• what happens at the clincal trials (animals)?

  -the drug is tested on animals to see the effect in a whole organism - all new medicines in the UK have tests on 2 different animals by law

  -efficacy, toxicity and dosage are tested at this stage
• what happes at the clinical trails (humans)?

  -the drug is tested on human volunteers first generally with a very low dose that increased. this is to make sure it is safe in a body that is working normally

  -the next stage is to test on patients with the condition
• what happens at double-blind trials?

  -the patients are often split into 2 groups: 1 given the drug, the other given a placebo. neither the doctor nor the patient knows if the patient is getting the drug or the placebo

  -once the drug is found to eb safe then the lowest effective dose is tested at thsi stage