1.4 MI Study Guide PLTW Flashcards
Vaccines, Epidemiology, Recombinant DNA, John Snow, etc
Vaccine
A harmless variant of a pathogen that stimulates a hosts immune system to mount defenses against the pathogen
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
What is smallpox?
A highly infectious disease characterized by small lesions on the skin, and ravaged society for centuries
What was Edward Jenner’s smallpox vaccination experiment?
Exposing a health patient to cowpox, a similar, yet less lethal virus, Jenner was able to make this individual immune to smallpox.
What happened to smallpox after the vaccine came out?
Wiped smallpox off the planet
What is a Live Attenuated Vaccine
Using a weakened version of a virus or bacterium so it cannot cause disease but still triggers an immune response
Live Attenuated Vaccine Examples
MMR, Polio (Oral), Yellow Fever
Killed/Inactivated Vaccines
made by killing or inactivating the virus or bacterium with heat, chemicals, or radiation, ensuring that it cannot replicate or cause disease
Killed/Inactivated Vaccine Examples
Polio (Inactivated), Hepatitis A, Rabies
Toxoid Vaccines
made by inactivating bacterial toxins (exotoxins) using heat or chemicals. The inactivated toxin (toxoid) stimulates the immune system to produce antibiotics
Toxoid Vaccine Examples
Diphtheria, Tetanus
Subunit/Conjugate Vaccine
These vaccines only contain specific parts of the pathogen (proteins/sugars) Conjugate vaccines combine polysaccharide antigens from the pathogen with the proteins to enhance the immune response (especially in young children)
Subunit/Conjugate Vaccine Examples
Hepatic B, Hib, PCV13
mRNA Vaccine
These vaccines injects mRNA to instruct cells to produce protein similar to a part of the virus. The immune system recognizes this as foreign and mounts an immune response
mRNA Vaccine Examples
Covid-19
Viral Vector Vaccine
use a different virus as a vector to deliver genetic material from the target virus into human cells. The genetic material then instructs the body to produce a protein from the pathogen prompting an immune response
Viral Vector Vaccine Examples
Johnson & Johnson Janssen Covid-19, AstraZeneca Covid-19
How body works with a vaccine
vaccine → recognition by immune system —> Binding and neutralization—> Activation of helper T-cells—> activation of B Cells and antibody production—> Activation of cytotoxic T cells—> Formation of memory cells—> clearing of vaccine antigen—> immunity
How the body works against a pathogen
pathogen→ pathogen recognition —> recognition by immune system—> binding and neutralizing—> activation of T cells—> phagocytosis
Recombinant DNA
A DNA molecule made in nitro with segments from different sources
Recombinant DNA Technology
The process of cutting and Recombining DNA fragments
Plasmids
A small DNA ring that carries accessory genes separate from those bacterial chromosomes
Vectors
An agent (as a plasmid or virus) that contains or carries a modified genetic material that can be used to introduce extra genes into a genome of an organism
Genes
A discrete unit of hereditary informations consisting of a specific nucleotide sequence of DNA and codes for proteins
Restriction Enzyme
A degradative enzyme that recognizes specific necelotide sequences and cuts up DNA
DNA ligase
A linking enzyme essential for DNA replication and recombinant DNA techniques
What Characteristics make an effective Vaccine?
Has low levals of side effects/toxicity, Protects against exposure to natural/ wild forms of a pathogen, should stimulate both an B-call and T-call response, and should not need many boosters (immunogical memory)
Where are the routes of adminstartions for a vaccinne
Mainly administered through injection (Subcataneous-fatty layer, Intrmuscular-muscle layer, and Intradermal-dermis-epidermis layer). There are also oral vaccines
Explain how recombinant DNA is preformed?
Recombinant DNA is when DNA and plasmid is cut using restriction enzymes and cutting restriction sites. Some of these sites can make a blunt (even) end or sticky ends (uneven). These sticky ends are used to make recombinant DNA molecules. This is used to cut a specific gene or interest so it can be inserted into a plasmid. Then once connected DNA ligase (linkining enzyme) brings/joins the DNA together.
What can go wrong during recombinet DNA?
Ligation could be unsuccessful sometimes the plasmid will ligate without a gene (self-ligation), Other items the DNA can be inserted backwards (inversion)
What are the two tools of molecular biology?
Restriction Enzymes (scissors) and DNA Ligase (glue)
What are the 4 guidelines needed for creating a new plasmid?
1) Use 1 restriction enzyme that will cut the plasmid ring as the viral gene (should not cut into to many small pieces)
2) Do not cut more than 20bps off of either side
3) It should not interup the orgin of replication (ori) or antibiotic resistance gene
4) Must have sticky ends.
Why HaeIII is unlikely to be used to create recombinant DNA
HaeIII creates blunt ends which makes it harder for DNA fragements to join together
Epidemiology
A medical science that delas with the incidence, distribution, and control of disease in a population
What are the (3) various roles held by an epidemiologists?
- Moniter the health of populations and search for patterns in diseases
- Assist in outbreak investigations
- Examine lifestyle factors/relationships to chronic illnesses
What is the role of an epidemiologist? What are they involved in?
investigate health related matters such as disease outbreaks and chronic illnesses by gathering information, examining data, and looking for patterns.
What causes cholera?
Passed through feces
How is cholera transmitted?
Through the consumption of contaminated water or food
What are the symptoms of cholera
- Dehydration
- Diarrhea
- Vommiting
- Abdominal Cramps
- Muscle weakness
- Fatigue
- Low BP
How do you calculate the attack rate?
formula
people who are ill/total amount of people who consumed
What is an epidemic curve?
A visual display of the onset of illness among cases associated with an outbreak. The epi-curve is represented by a graph with two axes that intersect at right angles
What information can an epidemic curve tell you?
Time trends, Outliers, magnitude, pattern of spread, and the likely time of exposure
What is the difference between a cohort study and a case study?
A cohort study follows a group of individuals (the cohort) over time to observe the occurrence of a specific outcome. Case studies, on the other hand, delve deep into a single individual, group, or event to explore a complex issue or phenomenon in detail
What are the advantages and disadvantages of a cohort study
Advantages:
Directly measure the risk and rate of a health outcome occurrence overtime
Disadvantages:
Require large sample sizes, expensive and time consuming
What are the advantages and disadvantages of a case study
Advantages:
Most effective for rare disease outcomes, and could have similar results to a cohort study it would just take less time
Disadvantages:
Does not yield an estimate for risk or rate, not efficient in control groups
