preventing and treating dieses (B6)

• Non-specific defences of the human body against all pathogens include:

  • Skin
  • Stomach
  • Nose
• White blood cells function to fight pathogens

  • There are two main types of white blood cells: lymphocytes and phagocytes
• Phagocytes:

  • Are attracted to areas of infection
  • Surround the pathogen and engulf it
  • Release enzymes that digest and destroy the pathogen
• Lymphocytes fight pathogens in two ways:

  • Antitoxins:
  • Bind to toxins produced by some pathogens, neutralizing them
  • Antibodies:
  • Target and help destroy specific pathogens by binding to antigens on the pathogens' surfaces
• New drugs are extensively tested and trialled for:

  • Toxicity: to check if it is harmful
  • Efficacy: to determine if it works
  • Dose: to establish the safe and effective amount to give
• Antibiotics:

  • Medicines that can kill bacteria in the body
  • Specific bacteria need to be treated by specific antibiotics
  • Antibiotics have reduced deaths from infectious bacterial diseases, but antibiotic-resistant strains of bacteria are emerging
• Treating viral diseases:

  • Antibiotics do not affect viruses
  • Drugs that kill viruses can damage the body's tissues
  • Painkillers treat symptoms of viral diseases but do not kill pathogens
• Vaccinations:

  • Involve injecting small quantities of dead or inactive forms of a pathogen into the body
  • Stimulate lymphocytes to produce the correct antibodies for that pathogen
  • Herd immunity occurs when a large proportion of the population is vaccinated against a disease, making it less likely to spread
• Monoclonal antibodies:

  • Produced by mouse lymphocytes combined with a tumour cell to make a hybridoma cell
  • Can be used to treat diseases such as cancer or in pregnancy tests
• • Skin:
  • Physical barrier against infection
  • Produces antimicrobial secretions
  • Microorganisms on the skin prevent pathogens from growing
• • Stomach:
  • Produces strong acid (pH 2) that destroys pathogens in mucus, food, and drinks
• Nose:

  • Cilia and mucus trap particles in the air, preventing them from entering the lungs
  • Trachea and bronchi produce mucus, which is moved away from the lungs to the back of the throat by cilia, where it is expelled
• double blind trials are when neither the participants nor the researchers know who is getting the treatment and who is getting the placebo (reduces bias)
• pre- clinical trials: testing on animals, cells and tissue to see if the drug is safe and effective
• clinical trial:

  • healthy volunteers receive low doses to see if the drug is safe and effective
  • if safe, larger number of healthy volunteers have patients to find the optimum dose
• digitalis comes from foxglove plants and give us drugs to treat heart conditions
• aspirin comes from willow tree and is used to treat headaches, fever, and inflammation (painkiller)
• penicillin was discovered by Alexander Fleming from penicillium mould (antibiotic)