Future Health (KPH W4)

Question 1

what is a cause?

Answer 1

an event, condition or characteristic that preceded the disease event
the outcome is determined by the presence/absence of exposure

Question 2

what is a necessary cause?

Answer 2

a cause that must be present for an outcome to take place

Question 3

what is a sufficient cause?

Answer 3

a cause that produces or initiates an outcome
(always causes an outcome)

Question 4

name different types of causation models and what they involve

Answer 4

line - genetic, environment
triangle - host, agent, environment
wheel - host, genetic, environment
web - social, genetic, agent, environment

Question 5

what is causal inference?

Answer 5

criteria set to appraise/interpret evidence to formulate a subjective judgement of a causal relationship

Question 6

define screening

Answer 6

a public health intervention where a defined population are asked a question or offered a test

Question 7

what do screening tests do?

Answer 7

test asymptomatic people
determines risk marker

Question 8

describe the basic characteristics of screening tests

Answer 8

simple
affordable
acceptable
low complication risk
not diagnostic

Question 9

what is the difference between germline and somatic mutations?

Answer 9

germline mutations are inherited (associated with inherited diseases)

somatic mutations are not inherited (associated with somatic disease)

Question 10

describe the DNA repair activity in germline vs somatic cells

Answer 10

very active in germline cells (alot of cellular energy required)

less active in somatic cells (higher rate of mutation)

Question 11

what is the function of DNA mismatch repair complex?

Answer 11

heterotetramer protein composition

detects DNA damage from DNA polymerase and activates it for downstream mismatch repair

Question 12

explain the mechanism of DNA mismatch repair complex

Answer 12

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

Question 13

what are the different ways DNA can be damaged?

Answer 13

base loss
base modification
single strand breaks
double streand breaks

Question 14

name mutagens that can increase rate of mutation

Answer 14

chemical exposure
diet
smoking
radiation
free radicals

Question 15

explain the process of repairing single stranded DNA damage

Answer 15

DNA ligase joins broken strands together

Question 16

explain the process of a nucleotide excision repair

Answer 16

NER multu-enzyme complex identifies DNA damage

DNA endonuclease recruited, it cuts DNA from within the molecule and removes the damaged section

Question 17

what diseases are caused by defective nucleotide excision repair?

Answer 17

xerodema pigmentosum
cockayne syndrome

Question 18

describe the characteristics of xerodema pigmentosum and cockayne syndrome

Answer 18

predisposition to light induced skin lesions/cancer
accelerated ageing
dwarfism
neurological abnormalities

Question 19

how are double stranded breaks repaired?

Answer 19

DNA endonuclease removed samaged parts and causes a reforming of the DNA through an overhang connection

Question 20

what can occur when multiple double stranded breaks occur at once in DNA?

Answer 20

complete translocation of DNA segments

Question 21

describe the characteristics of nijmegan breakage syndrome

Answer 21

rare autosomal recessive
defective homology dependant repair

radiation sensetivity
immunodeficiency

Question 22

what genes are involved in inherited breast and ovarian cancer?

Answer 22

BRCA 1 and BRCA 2
involved in homology dependent repair