Dealing with disease Flashcards
Natural Active immunity
Natural: no medical intervention
Active: using own immune system to create antibodies and memory cells
Immunological memory is developed: Subsequent exposures lead to memory cells proliferate and differentiate
Natural Passive immunity
Natural: no medical intervention
Passive: antibodies obtained by another individual
Passing of antibodies through breast milk or via placenta during pregnancy
Infant has a weak adaptive immune system, therefore gains antibodies directly from mother.
Artificial immunity what is it
Immunity to a disease with medical intervention
Artificial Active immunity
Artificial: Medical intervention required
Active: introduced pathogen/antigen results in the body producing antibodies
Vaccines contain weakened/ dead microbes/ fragments of the pathogen
Trigger the adaptive immune system
Immunological memory develops
Artificial passive
Body gains antibodies to pathogen (through injection of antiserum)
Vaccines what are they and types
Vaccines contain components that resemble the pathogens antigens, without causing disease whch This introduces the individual to the pathogen and allows them to create antibodies and memory cells for a rapid attack
Can either be:
Attenuated (weakened)
Inactivated (dead) pathogens
Toxoids: toxins that have been altered
RNA
What happens in the primary immune response
Delay in the adaptive immune response after first vaccination
Time required to find T and B cells complementary to the vaccine’s antigen
Some antibodies are produced
Memory cells are formed and stored
what happensin the secondary immune repsosne
After second vaccination, the memory cells created after the first vaccine, recognises the antigen
Large amounts of antibodies are produced
Faster response
Longer lasting immunity
More than one vaccination is required for immunity to form
Booster vaccines
Booster vaccines are required to stimulate any remaining memory cells to generate more antibodies and more memory cells because over time memory B and T cells die.
When are booster vaccines given
Boosters are given much later after a vaccination program
-how many years is it typically givne
Herd immunity
When the majority of people in a community are immunised to a disease, to prevent the spread of a disease to those who have not been vaccinated
The more people vaccinated, the less chance of infectious agent spreading
Artificial Passive immunity
Artificial: medical intervention
Passive: body does not produce own antibodies
Body gains antibodies to pathogen through injection of antiserum/antivenom which is produced by another organism
No immunological memory is developed
What is antivenom, what do antibody treatemnets like and are memory cells produced
Antivenom is a treatment made from antibodies that neutralize the venom of a poisonous animal, such as a snake bite helping to prevent harm after a bite or sting.Used to treat snake bites
Contains antibodies created by another organism
Antibody treatments increase the number of antibodies at the time of administer but declines shortly after.
No memory cells developed, therefore no immunological memory
Achieving herd immunity
Larger populations require more individuals immune to a disease
More contagious diseases require more people to be immune
Protects people who aren’t immune such as those unable to be vaccinated
Greater the percent of population, less infected
compare infectious and non infcetious disaeses, how are they cause,d what are charactierisictied of pahtognes, what are examples of non ifnectious diseases and infeitcosdisease
Non-infectious diseases
Illness not caused by a pathogen
Causes range from abnormal genes, lifestyle, cancer.
Examples include cystic fibrosis, cardiovascular disease, Type 1 diabetes.
Infectious diseases
Diseases caused by pathogens
Pathogens harm the host
Characteristics of pathogens:
Contagious: how easily it is transmitted
Virulent: how severe the pathogen is
Highly contagious and highly virulent are of greatest concern
what are non emerging disases
Diseases that were once a major public health problem and then declined dramatically in incidence, but then again becoming health problems for many people
what are emerging diseases
Diseases that have not occurred in humans before, have occurred previously but only affected populations in isolated places, or have occurred throughout history but have only recently been recognised as being caused by pathogens
Factors that influence the emergence and re-emergence of diseases
Evolution of organism: resistance to treatment due to changes to evolution of the pathogen.
Travel: increased exposure to other populations results in faster spread of diseases
Increased exposure to animals (zoonosis): spread of disease from another species to humans.
Increased population: larger populations lead to increased population densities increasing the likelihood of spread
Poor vaccination rates: loss of herd immunity
Lack of sanitation and poor hygiene
Human behaviour
Misuse of antibiotics
Examples of origin of diseases
HIV/AIDS from primates humans
SARS bats human
MERS camel human
Ebola bat human
Zika mosquito human
Are ebola, malara, measles, COVID-19 and aids emerging or non emerging diseases
Ebola-remerging
measles-re-emerigng
malaria-remerging
covid-19-emerging
aids-emerging
define epidemic, pandemic and endemic
Epidemic
is
Widespread of an infectious disease among a specific population at a particular time
Pandemic
Widespread of an infectious disease to different countries and or continents. Effect a greater number of people compared to epidemics.
Endemic
Constant baseline level in a population. Example: influenza.
Summarise how the colonisation of Europeans causedsusceptibility in diseases amongst Aboriginal and Torres StraitIsland peoples
First convicts in austraila introduced new diseases to indigneous popualtionsbecause austriala was isolated from other countries such a s smallpox, influenza and measles, resulting in widepsread diseases and death
Aboriginal communities were suepsctibile to these diseases becasue whilst the europeans had devleoped immunity towards diseases like measles and influenza at a young age, indigenous communities Indigenous communities were exposed to measles at adulthood. No immunological memory developed, leading to sever reaction.
Lack of knowledge and expiernce:
-indigneous communities responded to diseases diffiernetly in theri population and new diseases meant lack of knowledge in how to treat these new euorpena diseases
Additionally, indgineus communites were restricted from suffiencent food and water fm the european settlers which decreased their health status nad in tunr made them more susectble to disease.s
Methods in identifying pathogens
- Physical: identifying using a microscope the structure of the pathogen (virus/bacteria/other)
- Phenotypic: use of agar plates to allow certain pathogens to grow. The use of certain chemicals on agar allow the growth of certain pathogens. This allows scientists to identify the type of pathogen
- Immunological: diagnosis based on the presence of antibodies of antigens in a person’s serum. Use of ELISA test (Enzyme-linked immunosorbent assay).
- Molecular: genomic sequencing to identify the pathogen. Use of hybridisation-based detection which uses labelled segments of genetic material which are complementary to a pathogen’s genetic material.
If a signal is generated, it means the pathogen is present.
ELISA TEST STEPS
Step 1: antibodies specific to a certain pathogen are attached to a plate
Step 2: serum added to plate. If serum contains specific antigens, then they will attach to antibodies.
Step 3: enzyme added. If antigen-antibody complexes form, then enzyme will attach
Step 4: substrate is added to allow the enzyme to change colour if a antigen-antibody complex is formed.
how can diseases be transmitted
Airborne transmission
Sneezing or coughing creates aerosol droplets containing infectious particles
Eg. Influenza.
Droplet transmission
Respiratory droplets containing pathogens can fall on surfaces. Transferred if person touches eyes, mouth or nose.
Direct physical contact
Via touch, exchange of body fluids, sexual contact, mother to baby.
Eg. HIV
Indirect physical contact
Consumption of contaminated food /water, needles
Spread also due to vectors such as mosquitos
Eg. Salmonella, typhoid
Faecal-oral transmission
Pathogens from faeces can be consumed by another person via contamination of food or water
E.g. rotavirus causing diarrhoea
Controlling disease transmission - Prevention
Prevent the disease from spreading to other people
Keeping pathogen vectors away from human populations
Use of PPE
Disinfectants: applied to non-living materials (e.g. kitchen bench) to kill or slow the growth of pathogens
Antiseptics: applied to living tissue to kill or slow the growth of pathogens. Includes hand sanitisers
Vaccination
Quarantine and isolate to ensure that there is a physical distance between infected individuals and the rest of the population
how cna we treat diseases(viruses, bacteria and fungi casueed)
Antibiotics can be used to breakdown the cell wall of bacteria and inhibiting them from replicating
Antiviral drugs prevent the virus from entering or reproducing in host cells
Fungicides used to treat diseases caused by fungi.
Antivirals what are they and how theywork
Antiviral drugs prevent the virus from entering or reproducing in host cells.
Can work in a number of ways:
Preventing entry of the virus by binding to receptors that allow entry
Inhibit enzymes involved in reproduction or viral genome-
Inhibiting reverse transcriptase
Stopping newly formed viruses from being released from host cells
Inhibit transcription and translation
Prevent exit of virus from the cell (therefore reducing spread)
what is Immunotherapy, what is it desgiend to do and examples of it
Form of medical treatment that alters the immune system’s function.
Some immunotherapies are designed to increase the action of the immune system, while other suppress it.
Examples:
Antibody therapy using Monoclonal antibodies
Dendritic cell therapy
Cytokine therapy
Q: What is the purpose of altering antibodies in antibody therapy?
A: To treat cancer and autoimmune diseases.
Q: What are monoclonal antibodies?
A: Laboratory-made proteins that bind to a specific antigen.
Q: How do monoclonal antibodies work in treating diseases?
A: They trigger the killing of cancerous cells or self-recognizing cells for autoimmune diseases.
steps of producing monoclonal antibodies
Step 1: Identify and isolate an antigen found on the desired cell e.g. cancer cell.
Step 2: Produce a vaccine and vaccinate an animal such as a mice to produce antibodies against the antigen.
Step 3: Scientists extract B lymphocytes from the spleen of the mice
Step 4: Extracted B lymphocytes are fused with myeloma cells (rapidly-dividing cancerous human plasma cells) to form hybridomas. This allows B lymphocytes to grow and produce large quantities of antibodies.
Step 5: Hybridomas are selected and are cloned to produce large amounts of antibodies.
Step 6: Antibodies are collected and administered to the same cancer patient.
What is cancer?
s a disease in which some of the body’s cells grow uncontrollably and spread to other parts of the body.Cancer results from uncontrolled and unregulated replication of cells that invade other sites of the body.
Q: How do cancer cells bypass normal cell cycle checkpoints?
Accumulation of mutations in cancer cell DNA allows them to bypass normal checkpoints of the cell cycle.
Q: What are the common causes of cancer?
A: Cancer is caused by carcinogens such as radiation, chemicals, and viruses.
How do monoclonal antibodies work against cancer?
Antibody-dependent cell-mediated cytotoxicity (ADCC): monoclonal antibodies bind to cancer cells attracting other immune cells to destroy.
Complement activation: monoclonal antibodies bind to cancer cells and interact with complement proteins to form membrane attack complexes (MAC)
Complement activation: monoclonal antibodies bind to cancer cells and interact with complement proteins to form membrane attack complexes (MAC)
Q: How can monoclonal antibodies be used in autoimmune diseases?
A: Monoclonal antibodies can suppress the immune system in autoimmune diseases.
Q: What is the cause of autoimmune diseases?
A: Autoimmune diseases result from the body attacking its own self-cellsdue to a failrue to dififerniate between self and non self cells
Q: What role do B cells play in autoimmune diseases?
A: B cells release autoantibodies that target self-cells.
Q: What happens to T cells in autoimmune diseases?
A: T cells become autoreactive, meaning they react to self-cells as if they were non-self.
Immunosuppression
a reduction in the ability of the immune system to generate an immune response.
Monoclonal antibodies can inhibit
Monoclonal antibodoes can contribbute/assist in immunosuppression by
Inhibiting cytokine binding: They prevent cytokines (which activate immune cells) from binding to autoreactive immune cells, reducing harmful immune responses.
Targeting autoreactive B and T cells: Monoclonal antibodies can directly bind to these cells, either blocking their harmful activity or marking them for destruction by other components of the immune system.
What is the main drawback of using radiation or chemotherapy to treat cancer?
Radiation or chemotherapy can damage healthy tissues in addition to targeting cancer cells, leading to side effects such as fatigue, nausea, and tissue damage.
How do immunosuppressants help treat autoimmune diseases?
Immunosuppressants reduce the activity of the immune system, controlling the autoimmune response but also increasing susceptibility to infections and other diseases due to immunodeficiency.
What is the advantage of using monoclonal antibodies in cancer treatment?
Monoclonal antibodies are specific to the antigen of cancer cells, allowing for a more targeted treatment that minimizes damage to healthy tissues.
How do monoclonal antibodies help in autoimmune diseases?
Monoclonal antibodies can inhibit cytokines from binding to autoreactive immune cells or directly bind to autoreactive B and T cells, inhibiting their action or marking them for destruction.
What is the advantage of using monoclonal antibodies in cancer treatment?
Monoclonal antibodies are specific to the antigen of cancer cells, allowing for a more targeted treatment that minimizes damage to healthy tissues.
