phlt 304 test 1

Epidemiologic Triad

interaction between susceptible host, external agent, and environment that bring the three together

environmental contamination: natural

volcanoes, natural seepage, soil deposits, fires

anthropogenic causes

caused by humans, pollution

common effects of climate change

stronger storms, rising sea levels, damaged coral, warmer oceans, less snow, droughts and wildfire, food and water scarcity

water contaminants and waterborne illnesses

hepatitis A, cholera (killed by chlorine)

eutrophication

results in algae bloom, heavy production of algae

happens because of nutrient offloading, fertilizer runoff

body of water receives too many nutrients and elements such as nitrogen and phosphorous triggers heavy production

once algae dies, decaying process uses up a lot of oxygen, not leaving enough for the animals in the water

bioaccumulation

when an animal has a higher concentration of a chemical in its body than in the surrounding water (accumulation of a toxic chemical in the tissue of a particular organism

biomagnification

special kind of bioaccumulation where the animal is getting high amounts of the chemical through the food web, i.e fish and their mercury levels

bad fish

shark, swordfish, tiefish (fulf of MX), tuna (bigeye), marlin, orange roughey, king mackerel

onehealth

if we keep animals healthier, animal diseases won’t effect humans

ecosystem services

things we get from earth; water, air, lumber, etc

regulating services

help keep climate and resources stable, invisible until something goes wrong

ecosystem engineers

species that change biotic/abiotic materials to influence habitats i.e beavers and their dams

provisioning services

food and raw materials

supporting habitat services

a place to live for plants and animals

cultural services

benefits human get for being in the environment

cortisol levels improve

tourism, recreation

keystone species\*\*

species that play a key role in the function and structure of an ecosystem

predator, prey, mutualists, host

stressors affecting ecosystem services

chemical contaminants

biological factors

animal overexploitation

habitat loss: urban development, agriculture, fracturing

greenhouse effect

not enough heat escaping the atmosphere

* carbon dioxide
* methane
* nitrous oxide
* gasses w fluorine

effects of each gas in the atmosphere depends on…

how much is in the atmosphere

how long it stays in the atmosphere

how much it absorbs/warms

potency on a molecular basis are

not equivalent

carbon dioxide (co2)

some removed quickly, but some stays for 1000+ years

GWP= 1 year

global warming potential (GWP)

potency to stay in the atmosphere

methane (ch4)

12 year life in atmosphere

GWP= 25 years

nitrous oxide (n2o)

114 year life in atmosphere

GWP= 298 years

CO2 and ocean acification

affects animals with shells, shell is dissolving as the ocean becomes more acidic

environmental health

relationship between people and their environment

environmental risk assesmet

done when something is exposed to the environment

* how much of chemical is present
* how toxic is it
* how people are exposed and to what extent
* what is the likelihood of adverse effects (harm)

inhalation exposure

respiratory tract, surface area of lungs is large, rapid exchange of gasses/uptake of molecules

ingestion exposure

GI tract, small intestine has large surface area to facilitate nutrient absorption

skin exposure

depends if skin is damaged, warm, time on skin, properties,

concept of dose

central importance in determining health

adverse health effects when passing therapeutic level to toxic level

natural doesn’t mean good for you

particular contaminants

dust, fumes, mists, aerosols, fibers

top 10 causes of death environmentally

1. ischemic heart disease
2. chronic respiratory disease
3. cancers
4. unintentional injuries
5. respiratory infections
6. stroke
7. diarrheal diseases
8. diabetes
9. malaria
10. neo-natal conditions

clean air act

regulates many airborne contaminants

particulate contaminants/ particulate matter

less than 10 microns in diameter

* premature death
* nonfatal heart attacks
* irregular heart beat
* aggravated asthma
* reduced lung function
* increased respiratory symptoms

genes

made of DNA

unit of inheritance

code for inherited variable traits

protein formation

gene (DNA) → transcription → mRNA transcript → translation → protein

beneficial mutation

duh benefits population through process of mutation

intron

noncoding sections of an RNA transcript

spliced out before RNA molecule is translated into a protein

exon

region of the genome that ends up within an mRNA molecule

(what stays!!!!)

gene mutation

can change nothing, one amino acid, or a whole protein

genetic disorder

caused by mutation

deletion and insertion are more severe

Single Nucleotide Polymorphism (SNP)

variation in one nucleotide, single base position in DNA

CYP2D6

metabolizing

ex) when you consume morphine it's not an active therapeutic until the body enzyme metabolizes it

epigenetics

study of changes caused by activating or silencing genes (increasing or decreasing gene expression) without any change to the underlying DNA sequence

epigenetic modification

* consists of small molecules being attached to existing DNA
* small molecules added onto the DNA or histones, making it easier or harder to have gene expression
* does not change sequence in bases in DNA

mutation

consists of change in the DNA sequence

ex) changes in the bases in the DNA

DNA adduct

a piece of DNA covalently bonded to a chemical

isn’t a mutation but can cause mutations to form

DNA is damaged, resulting in abnormal replication

structure of DNA

* wrapped into histone protein core to form a nucleosome
* coiled further into solenoids
* solenoids organized into chromatin loops, each loop has 100,000 base pairs (ATGC)

methyl group

CH3 attachment, methyl group attaches directly to DNA but doesn’t change base sequence

when it gets close to the gene it SILENCES It

reversible

DNA Methylation\*\*\*

\
Addition of methyl group ME onto DNA

when close to a gene, reduces expression

* histone acetyltransferase
* deacetylases
* acetylation
* methylation

DNA Acetylation\*

repairs proteins and is a dynamic epigenetic modification done by HATS (lysine acetyltransferase), effects DNA binding ability, protein activity

DNA deacetylation

histone tails, DNA becomes more tightly wrapped around the histone cores, making it harder for transcription factors to bind to the DNA

* gene silencing

acetyl in methylation

makes it easier for gene expression to happen, loosens DNA for easier access

Bisphenol A (BPA)

associated! risks!

increased risk of miscarriage and gestational diabetes (women)

DNA damage to sperm/reduced fertility (men)

immunodeficiency

risk factor for certain kinds of cancer, specifically viral and lymphatic

Benzo(a)pyrene

changed into a very reactive molecule that covalently bonds with DNA

* mutation of the 12th codon of the Hras oncogene
* oncogene: gene which sometimes turns into a tumor cell

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Initiation

mutation of somatic cell

these cells can remain static (nondividing)

eliminated by apoptosis

somatic cell

every cell other than sperm and egg

progression

conversion of benign preneoplastic into neoplastic cancer

generation time

time needed for a quiescent cell to complete one cell division cycle to produce 2 daughter cells (amount of time for one cell cycle)

malignant cells

shorter generation time, smaller fraction of cells are in the resting and more are in the reproducing stage (too rapid!!)

proto-oncogene

managing normal cell growth, mutation turns it into just oncogene and then it’s bad!!!!!!

cancer cells have a lower level of…

methylation

autoimmune disease

immune system cannot differentiate self and non-self

lymph nodes

lymphocytes recognize and eliminate invading pathogens

spleen

assists body in protecting against bacterial infections

innate immunity

nonspecific immunity

had since birth

first line of defense

fast

* not effected by vaccines
* stomach, stomach acid

complement

plasma proteins that kill foreign cells, increase inflammatory response and attach phagocytes

natural killer cells

cytotoxic action against cancer cells

interferons

antiviral proteins

NK cells

effector lymphocytes of the innate immune system

Adaptive Immunity

acquired or specific immunity

* antigens


* slower than the first time exposed to pathogen, develops immunologic memory
* slower than innate immunity

antigen\*

molecule or substance that is foreign to the body that provokes an immune response

Cell mediated immunity

primarily involves T lymphocytes/ t cells

cytotoxic t cells

(CD8 cells) destroy infected host cells (cancer, transplant organs

helper t cells

(CD4) cells

* increase and support antibody production. cytotoxic t cells, natural killer cells, increase phagocytosis

long lived memory t cells

made after you first get sick, works fast for future exposure to same antigen

cytotoxic

cell killing, factors destroy cell once infected

humoral (anti-body mediated) immunity\*

encounter pathogen and remember antigen (non-self indicator to B cells)

plasma cells

make antibodies that are specific for the antigen that initiated their production, can make 2000 per second

antibody function

proteins secreted into plasma to help eliminate foreign organisms

active immunity

after exposure to a foreign organism, immune cells produce antibodies and memory cells

passive immunity

transfer of antibodies from someone else to the vulnerable person

* no memory cells formed → short terms protection until antibodies consumed or catabolized

tolerance

body’s ability to correctly recognize self and not attack it

immune system’s appropriate lack of response to “self”

autoimmunity

when tolerance fails and body develops autoantibodies to own tissues, no known cause and no preventative methods available

* sjorn’s syndrome (4 million US women, dry eyes & mouth) can occur with lupus or rheumatoid arthritis

inflammation

body’s response to injury, infection, certain environmental exposure

intestinal dysbiosis

perturbation in the composition of the gut microbiome relative to the composition of the gut microbiome in healthy individuals

circadian rythms

physical, mental, behavioral changes that occur over a 24 hour period

suprachiasmatic nucleus (SCN)

overall master clock

* located in the brain
* controls production of melatonin

insufficient sleep

changes in mood, memory, cognition

* increased risk of obesity because less sleep decreases leptin, making you hungry and wanting carbs
* type 2 diabetes and high tension and high blood pressure
* sleep hygiene

which chromosome determines sex

23rd

color blindness

recessive and sex-linked

alcohol dehydrogenase (ADH)

converts ethanol to acetaldehyde (toxic)

aldehyde dehydrogenase (ALDH)

oxidized aldehydes to acetate (less toxic)

* acetate is broken down into CO2 and H2O

asian flush

50% of Chinese, Koreans, and Vietnamese populations have high incidence of atypical form of ADH (rapidly metabolize, red)

lead

children of ages 0-6

* reduced IQ
* can be stored in the bones with calcium, during pregnancy it’s released from bones and exposed to fetus

ground-level ozone

health effects of breathing this

* chest pain
* coughing
* throat irritation
* airway inflammation
* worsen bronchitis, emphysema, asthma

ground level ozone compounds

* carbon monoxide (CO)
* sulfur dioxide (SO2)
* nitrogen dioxide (NO2)