Future Health (KPH W4) Flashcards
what is a cause?
an event, condition or characteristic that preceded the disease event
the outcome is determined by the presence/absence of exposure
what is a necessary cause?
a cause that must be present for an outcome to take place
what is a sufficient cause?
a cause that produces or initiates an outcome
(always causes an outcome)
name different types of causation models and what they involve
line - genetic, environment
triangle - host, agent, environment
wheel - host, genetic, environment
web - social, genetic, agent, environment
what is causal inference?
criteria set to appraise/interpret evidence to formulate a subjective judgement of a causal relationship
define screening
a public health intervention where a defined population are asked a question or offered a test
what do screening tests do?
test asymptomatic people
determines risk marker
describe the basic characteristics of screening tests
simple
affordable
acceptable
low complication risk
not diagnostic
what is the difference between germline and somatic mutations?
germline mutations are inherited (associated with inherited diseases)
somatic mutations are not inherited (associated with somatic disease)
describe the DNA repair activity in germline vs somatic cells
very active in germline cells (alot of cellular energy required)
less active in somatic cells (higher rate of mutation)
what is the function of DNA mismatch repair complex?
heterotetramer protein composition
detects DNA damage from DNA polymerase and activates it for downstream mismatch repair
explain the mechanism of DNA mismatch repair complex
first signals to DNA polymerase to halt transcription
recruits DNA exonuclease which externally digests DNA (destroys new strand from unfinished end)
once damage removed, complex dissociates
what are the different ways DNA can be damaged?
base loss
base modification
single strand breaks
double streand breaks
name mutagens that can increase rate of mutation
chemical exposure
diet
smoking
radiation
free radicals
explain the process of repairing single stranded DNA damage
DNA ligase joins broken strands together
explain the process of a nucleotide excision repair
NER multu-enzyme complex identifies DNA damage
DNA endonuclease recruited, it cuts DNA from within the molecule and removes the damaged section
what diseases are caused by defective nucleotide excision repair?
xerodema pigmentosum
cockayne syndrome
describe the characteristics of xerodema pigmentosum and cockayne syndrome
predisposition to light induced skin lesions/cancer
accelerated ageing
dwarfism
neurological abnormalities
how are double stranded breaks repaired?
DNA endonuclease removed samaged parts and causes a reforming of the DNA through an overhang connection
what can occur when multiple double stranded breaks occur at once in DNA?
complete translocation of DNA segments
describe the characteristics of nijmegan breakage syndrome
rare autosomal recessive
defective homology dependant repair
radiation sensetivity
immunodeficiency
what genes are involved in inherited breast and ovarian cancer?
BRCA 1 and BRCA 2
involved in homology dependent repair
