Non-communicable diseases Flashcards
1
Q
NCDs overview
A
long duration, slow onset, not transmissible from person to person
eg. cardiovascular diseases, cancer, diabetes etc
2
Q
risk factor definition
A
anything that increases the likelihood of developing a particular disease
3
Q
Risk groups
A
- Medical condition that inc risk
- Behaviour eg smoking drinking
- hereditary. eg family history
4
Q
what are the
- preexisting conditions
- behavioural/lifestyle choices
- hereditary/genetic factors
associated with strokes
A
conditions:
- hypertension
- high cholesterol
behaviour:
- excessive salt
- excess alcohol activity
hereditary
- sickle cell disease
5
Q
what are the
- preexisting conditions
- behavioural/lifestyle choices
- hereditary/genetic factors
associated with lung cancer?
A
conditions:
- chronic lung diseases
behaviour:
- smoking
- asbestos exposure
- radiation exposure
hereditary:
- 1st degree family member with lung cancer
- gender
6
Q
what are the
- preexisting conditions
- behavioural/lifestyle choices
- hereditary/genetic factors
associated with asthma?
A
conditions:
- another allergic condition
behaviour:
- exposure to allergens
- smoking
hereditary:
- blood relative with asthma
7
Q
what are the
- preexisting conditions
- behavioural/lifestyle choices
- hereditary/genetic factors
associated with type 2 diabetes?
A
conditions:
- aged 45+
- gestational diabetes
behaviour:
- physical activity < 3 times a week
- being overweight
hereditary:
- blood relative with diabetes
- certain ethnicities
8
Q
tumour def
A
a lump or growth of abnormal cells that undergo uncontrolled cell division
9
Q
what is the definition of cancer?
A
a disease caused by usually caused by a mutation that causes uncontrolled cell division and leads to the formation of a tumour
10
Q
4 typed of cancer
A
- Carcinoma (external & internal body surfaces)
- Sarcomas (supporting tissue)
- Lymphomas (lymph nodes and tissue of IS)
- Leukaemias (blood cells)
11
Q
Benign tumour
A
- Uncontrolled division
- Slow growing, located within one specific tissue, cells do not break off & spread
- not normally life threatening but can apply pressure
12
Q
Malignant tumour
A
- tumours grow rapidly
- cells can and do break off & spread to other tissues
- one metastic = cancer
- primary tumour (original), secondary tumour
13
Q
Control of cell division
A
proto-concogenes & tumour supressor genes
14
Q
Proto-oncogenes
A
- Controls normal cell growth
- Stimulates cell division after stimulation from growth factor
- If a mutation occurs, forms oncogene
- ∴ DNA replication is triggered without the extra-cellular growth factor, causing abnormally high production of GF
15
Q
Tumour supressor gene
A
- TSG codes for production of protein that stops cell division & causes apoptosis
- If mutation occurs, stops production of protein
- Leads to continual division
16
Q
outline the role of the c-Myc gene and explain [how its mutated form can cause cancer]
A
regulator gene on chromosome 8 responsible for regulating 15% of gene expression
[Myc constantly expressed –> unregulated expression of genes –> cell proliferation and cancer formation]
17
Q
p53
A
- codes for transcription factor
- also has several anti-cancer effects
- damaged dna is repaired by proteins activated by p53
- Can stop cycle at g1 to repair damage
18
Q
Mutagen
A
- physical, biological or chemical agent that mutates DNA causing frequency of mutations to increase
eg. UV radiation, alcohol, virus
19
Q
Carcinogen
A
a mutagen that specifically leads to cancer as a result of uncontrolled cell division
20
Q
outline the role of the Ras gene and explain [how its mutated form can cause cancer]
A
- division stimulated by extra-cellular messengers
- [division stimulated by Ray gene without hormone, cell cycle inhibition removed]
21
Q
Explain how smoking contributes to lung cancer [6]
A
- tar is a known carcinogen which enters lung cells
- destroyed cilia prevent removal of tar, hence have more time in contact with epithelial cells
- enters nucleus
- Proto-oncogene mutates to form oncogene
- uncontrolled cell division
- formation of tumour cells
22
Q
why does chance of cancer increase with age
A
- more mutations
- weaker immune system
- more exposure to carcinogens
23
Q
how do viruses cause cancer
A
- their DNA enters nucleus
- causes mutation that affects protooncogenes
- leads to uncontrolled cell vision
24
Q
X-rays
A
- high energy radiation
- x rays passes through soft tissue, film turns black
- bones absorb x rays, film turns white
-quick and easy, cannot distinguish without further tests
25
Mammography
- low energy X rays
- can detect small tumours in breast tissue
- breast places between two plates which press firmly together
- mammogram examined to identify any areas of calcification
-quick, non invasive, cannot distinguish without further tests
26
CT scan
- X rays passing through the body at different angles
- Gives detailed image (tomogram) of the internal structure of the body
- Patient lies down continuously moved through a rotating x-ray beam
- on the opposite side of the body x rays are detected
- Gives more detail than standard x-ray (3D image)
-non invasive, costly, can't distinguish without further tests
27
MRI
- Magnetic resonance imaging
- single scan can give multiple pictures from many angles
- Patient has to lie very still, no metal
- Magnet creates magnetic field that lines up the protons in hydrogen atoms
- beam of radio waves spin protons and signal emitted is converted into detailed 3D image
+ non-invasive; good for soft tissues
- costly; can't distinguish without further tests
28
PET scan
- produces 3d images of functional processes in the Boyd
- uses tracer (fluorodeoxyglucose most common)
- FGS injected to the patient prior to scan. Uptake is a marker for uptake of glucose. cancerous cells metabolise faster than normal, so absorb more FGS
- Pet scan detects radiation given off by tracer
+ accurate; fine detail; 3D coloured images
- can't distinguish without further tests
29
Biopsies
- Removal of a sample of tissue
- send to lab to be analysed and to distinguish between cancerous and non-cancerous
- Bone marrow biopsies- diagnose blood cancers, detected cancers that start somewhere & spread to BM
- Endoscopic biopsies- smear test
- Needle biopsies- used when tumour felt through skin
+ can distinguish
- invasive
30
Blood tests
- Diagnostic and monitoring purposes
- CAA125- high levels may mean ovarian cancer
- P (prostate-specific antigen)- detect prostrate cancer
+ effective diagnostic tool
- invasive
31
Ultrasound
- high-frequency sound waves
- handheld transducer moved over skin which delivers sound waves which reflect off organs and are detected
+ very safe, cheap, portable
- can't distinguish without further tests
32
what is screening
testing people who are known to be at risk of a certain condition before symptoms start
Aim= enable better outcome for individual
eg. breast, prostrate. cervical, bowel
33
Reliability
not 100% reliable or accurate
However, potentially reduce the risk of developing the condition if individual acts on advice given & make appropriate lifestyle changes
34
False negative may be due to
- cancer doesn't show up x-ray, may be too small, human error
35
False positives may be due to
increased number of screening, human error
36
Suggest how isoflavone may affect action of oestrogen
- has similar shape to oestrogen
- hence complementary to receptor
- prevents oestrogen from binding
37
sensitive vs specific test
sensitive- may pick it up early on
| specific- only picks it up when cancer is present
38
biological marker examples
protein, glycoprotein, glycolipid
39
features of cam that allow growth factors to bind
proteins & glycoproteins act as receptors, complementary
40
Breast cancer genetics test
- BRCA1 & BRCA2
- 40-90% of women carrying mutations in BRCA genes will develop cancer
- Risk increases with age
41
BRCA1 & BRCA2
- These genes produce tumour suppressor proteins
- Proteins repair dna
- mutations= failure to repair dna
- other genes eg TP53 + PTEN
42
Who can have genetic screening for breast cancer
- Strong family history
- Mutation research carried out on living relative with cancer to determine faulty gene
- then, a faulty gene is identified in an individual ie predictive testing
- This process is expensive for NHS
43
Bowel Cancer
- Hereditary non-polyposis colorectal cancer= type of bowel cancer caused by a mutated gene
- Mutation in genes which repair DNA
44
Benefits & negatives of genetics testing
```
+
relief from uncertainty
can make informed decisions about future
lifestyle changes
inform individual to make appropriate treatment decisions
```
-
anger, anxiety, depression
-which treatment to have
-absence from work etc
45
Treating cancer- surgery
Breast:
Lumpectomy- removal of tissue and surrounding tissue
Masectomy- removal of entire breast. Lymph nodes may also be removed
Colon:
Colectomy- removal of part of colon containing tumour
Ends of colon are joined back together by anastomosis. May need temporary stoma
46
Treating cancer- Chemo
- can be used prior to surgery to shrink the tumour. Or after surgery to ensure all cells are removed. Or to treat cancer which has spread
- Uses chemicals that are toxic to dividing cells
- Cancer cells divide more rapidly than normal cells, so it has more effect on them
- But can affect whole body rather than just cancer cells eg. bone marrow cells, hair follicles etc as these divide *faster and more regularly*
symptoms: hair loss, fatigue, loss of appetite, nausea and vomiting
47
Treating cancer- Radiotherapy
- uses ionising radiation to destroy cancer cells
- Destroys actively growing cell more than others
- causes damage to dna. especially if going through SMR
- can be targeted accurately to tumour
- can be used before or after chemotherapy
48
Treating cancer- Immunotherapy
- anticancer drugs can be attached to monoclonal antibodies which bind specifically to cancer cells
- Or can be tagged with enzyme that converts inactive form of cytoxic drug into active form
- ONLY attach to specific cancer cells, so can be administered at high dose
- ADEPT= antibody directed enzyme prodrug therapy
- eg. Herceptin- user for breast cancer. Has complementary binding sites for a specific protein receptor on cam of breast cancer cells. Binds to it and stops cells dividing rapidly
49
Treating cancer- Complementary therapies
- Focuses on making person feel better during other treatments
- Reduces side effects
- eg, reiki, meditation, acupuncture, hypnotherapy
- Positive mental attitude can have positive impact on improving effectiveness of immune system
50
Treating cancer- Hormone related therapies
-Tamoxifen- used to treat breast cancer
-Oestrogen stimulates gene transcription:
Diffuses through csm, binds to a specific receptor, allostery, receptor complex binds to coregulator, diffuses to nucleus, binds with chromatin, transcription occurs, increases growth and division of breast cancer cells
-Tomoxifen binds to oestrogen receptor. Complex still forms
-But, It does not undergo allostery, so blocks binding of coregulator, no transcription occurs
-Effective for some types of breast cancer in short term. After 2-3 years, woman can develop resistance. So different drug needs to be prescribed to reduce oestrogen levels
