Biology 6 Vaccination and monclonal antibodies

Defence system

-skin acts as a physical barrier, secretes antimicrobial substances.

Hairs and mucus traps pathogens in nose

Trachea and bronchi secrete mucus to trap pathogens. The cilia in bronchi waft mucus up so it can be swallowed. The stomach HCl will then kill the pathogen.

White Blood cell travels around blood and patrol for microbes. 

 Engulf and phagocytosis

Producing antibodies - antibodies produced are specific to the cell that is being targeted.

Producing antitoxins - counter attack toxins 

Vaccination -Giving you a dead or inactive disease, it stimulates your bodies natural response to pathogens. 

Stimulates white blood cell to produce antibodies. 

Vaccination involves introducing small quantities of dead or inactive forms of a pathogen into the body to stimulate the white blood cells to produce antibodies. If the same pathogen re-enters the body the white blood cells respond quickly to produce the correct antibodies, preventing infection. 

If the same pathogen re-enters the body the white blood cells respond quickly to produce the correct antibodies, preventing infection. 

Herd Immunity - When a high percentage of the population is vaccinated, it is difficult for infectious diseases that are also contagious to spread, because there are not many people who can be infected

Painkillers - Drugs that relieve pain. They don't actually tackle the cause of disease or kill pathogens. They reduce symptoms. E.g Aspirin

Antibiotics - (Bacteria) They kill or prevent the growth of pathogenic bacteria without killing body cells. Different antibiotics kill different bacteria. 

Antibiotics do not viruses (flu cold) because viruses hide in body cells and antibiotics aren't designed to harm body cells.

Bacteria can mutate allowing it to become resistant to the antibiotic. When you treat infection all non-resistant bacteria will die to allow resistant one to flourish. 

MRSA is a resistant strain to all current antibiotics.

Prevent resistant strains - Stop over prescribing drugs and finish the whole course.

Plants produce a variety of chemicals to defend against pathogens.

A lot of current medicines were discovered by studying plants. 

Traditionally drugs were extracted from plants and microorganisms.

•• The heart drug digitalis originates from foxgloves.

•• The painkiller aspirin originates from willow.

•• Penicillin was discovered by Alexander Fleming from the Penicillium mould.

The area around mould was free of bacteria.

Most new drugs are synthesized by chemists in the pharmaceutical industry. However, the starting point may still be a chemical extracted from a plant.

Preclinical Trials

- Drugs tested on human cells and tissues in the lab.n

Live animals - Test for efficacy Toxicity and best dosage(concentration and how often). 2 different live mammals. Cruel on animals vs best way to make sure drug isn't dangerous for humans

-Healthy volunteers make sure no harmful side effects when the body is working normally.Low then increased.

Ill Volunteers

- The optimum dose(most effective few side effects) is found

Placebo effect. Double-blind Trials

The results of testing and trials are published only after scrutiny by peer review.

Produced by B- lymphocytes 

Monoclonal antibodies are produced from lots of clones of a single white blood cell. All antibodies are identical and will only target one specific protein antigen. 

Lymphocytes don't divide very easily. Tumor cells divide lots but don't produce antibodies. So B lymphocyte x tumor cell. == hybridoma.

Hybridoma cells cloned == monclonal antibodies.

You can make monoclonal antibodies to bind to anything you want e.g an antigen found on the surface of only 1 cell. 

Really useful-  Becuase they only bind to the target molecule. The specific cell in the body.

Negative side effects - High Blood pressure vomiting 

Treat Diseases - Bind to specific cells and antigens in the body.

Cancer cells have antigens on their cell membranes that aren't found on normal body cells.Tumor Markers. In the lab, you can make monoclonal antibodies that will bind to specific tumor markers.

An anti-cancer(toxic drug or a radioactive isotope) drug will be attached to the monoclonal antibody. The antibodies are given to a patient through a drip. Antibodies only kill specific target cells but not normal cells.

Labs- Used to bind to hormones and other chemicals in blood to measure their levels. Locate specific molecules on a cell or in a tissue. Antibodies are bound to a fluorescent dye. The antibodies will attach to target molecule and will be detected using dye.