PLTW Medical Interventions- 1.4 Review

Edward Jenner

Gave boy a different strand of pox (cow pox) to use as a virus. Because a virus only runs once, it worked as a vaccine. Then gave the boy smallpox, and the boy was immune.

Innate Immunity

nonspecific defense mechanisms that come into play immediately or within hours of an antigen's appearance in the body (skin and chemicals)

Passive Immunity

mother passes on antibodies to child through breastfeeding

Live- Attenuated Vaccines

Alive, but very weak; Made when the virus is weakened to such a level that they reproduce only 20 times in the body; Potential of side effects; EX: MMR (measles, mumps and rubella combination vaccine), varicella and the intranasal form of influenza.

Inactivated Vaccines

Bacteria is completely killed using a chemical, usually formaldehyde; Dead pieces of bacteria are put into vaccine; Strength tends to wear off over time

Multiple doses are necessary; Zero chance of developing disease related symptoms; EX: hepatitis A, hepatitis B, poliovirus, haemophilus influenzae type b (Hib), meningococcal, pneumococcal and the injected form of influenza.

Complement System

group of proteins that meets invaders such as bacteria

Antigens

molecules that the body recognizes as foreign substances

Complement Proteins

trigger inflammation, attract eater cells such as macrophages to the area, coat intruders so that the eater cells are more likely to devour them, kill intruders

Phagocytes

group of immune cells specialized in finding and "eating" bacteria, viruses, and dead or injured body cells; types include granulocyte, the macrophage, and the dendritic cell

Macrophages ("big eaters")

are slower to respond to invaders than the granulocytes, but they are larger, live longer, and have far greater capacities. Macrophages also play a key part in alerting the rest of the immune system of invaders. Macrophages start out as white blood cells called monocytes. Monocytes that leave the bloodstream turn into macrophages.

Dendritic cells

"eater" cells and devour intruders, like the granulocytes and the macrophages. And like the macrophages, the dendritic cells help with the activation of the rest of the immune system. They are also capable of filtering body fluids to clear them of foreign organisms and particles.

Lymphocytes

white blood cells that originate in the bone marrow but migrate to parts of the lymphatic system such as the lymph nodes, spleen, and thymus; types include T cells and B cells

lymph vessels

for transportation and storage of lymphocyte cells within the body

T Cells

include helper and killer cells

Helper T cells

are the major driving force and the main regulators of the immune defense. Their primary task is to activate B cells and killer T cells.

Killer T cell

is specialized in attacking cells of the body infected by viruses and sometimes also by bacteria. It can also attack cancer cells.

B lymphocyte cell

searches for antigen matching its receptors. If it finds such antigen it connects to it, and inside the B cell a triggering signal is set off.

Plasma cell

is specialized in producing a specific protein, called an antibody, that will respond to the same antigen that matched the B cell receptor.

Memory Cells

are the second cell type produced by the division of B cells. These cells have a prolonged life span and can thereby "remember" specific intruders.

First line of defense of immune system

skin, mucous membranes

Second line of defense of immune system

groups of cells, tissues, organs; eater cells

Third line of defense of immune system

memory cells

Similar Pathogen Vaccine

(live attenuated) begin with pathogen and alter it in some way

Smallpox virus

contain cowpox viruses but not the bacteria and other impurities found in the fluid collected from such pustules - similar pathogen

Attenuated Vaccine

(live attenuated) alters pathogen; must be similar but not identical; protect against mumps, polio, rubella, and yellow fever

Measles virus

starts with fever, runny nose, cough, red eyes, and sore throat. It's followed by a rash that spreads over the body. Measles virus is highly contagious virus and spreads through the air through coughing and sneezing - example of live attenuated

Killed Vaccine

(inactivated) disables a pathogen's replicating activity while keeping immune responses and shapes intact; inactivate through heat of radiation; will not produce full immune response so requires booster shots

Polio virus

uses cells within tissue culture to make copies of itself - example of killed vaccine

Toxoid Vaccine

(inactivated) goal is to condition the immune system to combat not an invading virus or bacteria but rather a toxin produced by that invading virus or bacteria; booster shots needed

Tetanus

caused by toxins created by the bacteria Clostridium tetani - example of toxoid

Subunit Vaccine

small portion of vaccine; contains a piece of the protein coat that surrounds the virus' DNA

Hepatitis B

A serious liver infection caused by the hepatitis B virus

Naked DNA Vaccines

use a gene from a pathogen to generate an immune response; small loops of DNA invade body cells and incorporate themselves into the cells nuclei; made using PCR and vectors

HIV

The human immunodeficiency virus is a lentivirus that causes HIV infection and acquired immunodeficiency syndrome. - example of DNA/RNA vaccine

Restriction Enzymes

cut DNA sequences at known locations

DNA Ligase

enzyme that allows scientist to paste the ends of DNA molecules together by matching sticky ends with their base pairs

Restriction Endonuclease

proteins that cut out regions of Dna; move across DNA molecule and break the bond they are coded for, leaving behind sticky ends; EX: BamHI, EcoRI, HaeIII, HindIII, PstI

Plasmids

small rings of DNA that exist independently on a bacterial chromosome; can be copied and passed on; created DNA is passed into a plasmid (transformation)

Herd Immunity

Vaccinating a large percentage of a community to interrupt transmission of contagious disease

Epidemiology

Branch of medical science concerned with the incidence, distribution, and control of diseases that affect large numbers of people.

Explain why the Hepatitis B vaccine is administered multiple times over the course of a child's life. What does it mean when doctors use the term "booster shot"?

Hepatitis B vaccine is created through the use of dead Hep B pathogens and / or pieces of the Hep B pathogen. This is a way to ensure the recipient does not contract the disease, but it is also not as effective a way for the body to provide 'recognition' of the pathogen. Administering it in three doses helps the development of the memory B lymphocyte cells and ensures immunity against the disease.

Explain how doctors can

determine if you will require an additional dose of a vaccine.

A doctor can take your blood and do what is called an 'immunity titer'. He will look for the antibodies against the disease in question. This antibody test may even be a form of the ELISA test we conducted to determine what antigen Sue was sick with. ELISA tests can test for antibodies or antigens it depends on how the test is designed.

It can be said that a vaccine does not prevent infection; rather it primes the immune system to respond to an invader. Using information about human immune response, explain this statement. Mention what happens in the body from the time of vaccination through contact with the infectious agent.

It is not that the person doesn't contract the disease, it is that the person now has immunity against the pathogen. After a vaccination, if a pathogen enters the body then the memory B lymphocytes can immediately activate the cytotoxic T cells in the case of a virus, or activate the neutrophils in the case of a bacteria. Initially, when a vaccine is administered and the body recognizes it as a pathogen, an eater cell such as a macrophage, dendritic phagocytize 'eats' the pathogen and presents the pathogen cite on it's surface. This activates the B lymphocytes that create memory B cells or plasma cells that produce antibodies. These antibodies 'tag' the pathogen for ingestion by other eater cells, or the memory B cellsactivate cytotoxic T cells of handle the virus invaders.

Experimental Epidemiologist Study

Epidemiologists have control over the circumstances from the start

Observational Epidemiologist Study

Epidemiologists do not have control over circumstances

Cohort Study

Select the study population according to their exposure regardless of whether they have the disease or health outcome you're studying, then determine the outcomes and compare them on the basis of the individuals' exposure

Case- Control Study

Epidemiologist works backward; Participants are selected on the basis of the presence or absence of the disease or outcome in question, so you have one group of people with the health problem and one without

B cells produce which cells?

Plasma cells and memory cells

Which of the diseases mentioned in unit 1.4 are viruses?

Polio, Small Pox, Measles, HIV, Hep B

What is active immunity?

Acquired immunity or Innate Immunity

Epidemic

Affecting an atypically large number of individuals within a population, community, or region at the same time

Epidemiology

A branch of medical science that deals with the incidence, distribution, and control of disease in a population

Herd Immunity

The resistance of a group to an attack by a disease to which a large proportion of the members of the group are immune

Inoculation

The introduction of a pathogen or antigen into a living organism to stimulate the production of antibodies

Plasmid

A small ring of DNA that carries accessory genes separate from those of the bacterial chromosome

Recombinant DNA

A DNA molecule made in vitro with segments from different sources

Vaccination

A procedure that presents the immune system with a harmless variant of a pathogen, thereby stimulating the immune system to mount a long-term defense against the pathogen

Vaccine

A harmless variant of a pathogen that stimulates a host's immune system to mount defenses against the pathogen