module 4 - 12.7 preventing and treating disease Flashcards
what is natural immunity?
- immunity that occurs naturally in the body
hat is natural active immunity?
- when pathogen is met for the first time, immune system is activated and antibodies are formed - destructs antigen
- immune system produced T and B memory cells so if pathogen is met again, immune system can immediately destroy it
why is it natural active immunity known as active?
because the body has self acted to produce antibodies and/or memory cells
what is natural passive immunity?
- new born babies cannot make antibodies
- some antibodies cross the placenta from the mother so has some immunity at birth
- milk (colostrum) has high antibodies, infants gut allows these glycoproteins into bloodstream without being ingested
what is artificial passive immunity?
antibodies are formed in one individual, extracted and then injected into bloodstream of another
what is artificial active immunity?
immune system of the body is stimulated to make its own antibodies to a safe form of antigen (vaccine) which is injected into the bloodstream
what are the steps of artificial active immunity?
- pathogen is made safe so the antigens are intact but there’s no risk of infection
- small amounts of safe antigen are injected into blood
- primary immune response is triggered by foreign antigens, body produces antibodies & memory cells if infected with live pathogen
- contact with live pathogen - secondary response triggered & you destroy pathogen rapidly
what may vaccines contain?
- killed or inactive bacteria and viruses
- weakened strains of bacteria or viruses
- isolated antigens extracted from pathogen
- genetically engineered antigens
what is an empidemic?
when a communicable disease spreads rapidly to a lot of people at a local or national level
what is a pandemic?
when a communicable disease spreads rapidly across a number of countries (worldwide)
what can prevent epidemics?
mass vaccination but must be changed to remain effective
what is herd immunity?
when a mass number of people have been vaccinated - minimal opportunity for outbreak to occur
what is the impact of medicines?
- penicillin - cures bacterial diseases
- computer programmes can build up to 3D models of key molecules , pathogens and antigen systems
- analysis of genomes and pathogens - target drugs
what is the source and action of penicillin?
SOURCE - extraction originally from mould
ACTION - antibiotic against many common bacterial diseases
what is the source and action of docetaxel/paclitaxel?
SOURCE - yew trees
ACTION - treatment of breast cancer
what is the source and action of aspirin?
SOURCE - sallow (willow) bark
ACTION - painkiller, anticoagulant, anti-inflammatory
what is the action and source of prialt?
SOURCE - venom of cone snail
ACTION - new pain-killing drug
what is the source and action of vancomycin?
SOURCE - soil fungus
ACTION - antibiotics
what is the source and action of digoxin?
SOURCE - extracted from foxgloves
ACTION - powerful heart drug, treats atrial fibrillation & heart failure
what are pharmogenetics?
- analysing human genome rapidly and cheaply
- science interweaving knowledge of drug actions with personal genetic material
what is synthetic biology?
- techniques of genetic engineering
- enables use of bacteria as biological factories
- redesigning organisms for useful purposes
what is selective toxicity?
when antibiotics interfere with the metabolism of the bacteria without affecting metabolism of the human cells
how are antibiotics becoming less effective?
bacteria becomes more exposed and more resistant to antibiotic
- may also come from over prescribing antibiotics
what is the development of antibiotic resistant bacteria?
random mutations occur within bacteria and produce one not affected by drug, that will then survive & reproduce, passing on antibiotic resistance to daughter cells
what is MRSA?
- bacterium carried by up to 30% of population on skin or in nose
- in body - causes boils, potentially fatal septicaemia
- was treated effectively with methicillin - produced mathicillin-resistant strains
what is C. difficile?
- bacterium in guts of 5% of population
- produced toxins that damage linings of intestines - leads to diarrhoea & bleeding
- when commonly used antibiotics kill off ‘helpful’ bacteria it survives & reproduced rapidly
how can antibiotic resistant infections be reduced?
- minimising use of antibiotics, ensuring every course of antibiotics is completed
- good hygiene in hospitals, care homes & in general
