Clinical relevance of Biochemistry 2 Flashcards
Name and describe 3 functions of cholesterol in health?
Plasma membrane - maintains structure and stability
Cell signalling - Forms a lipid ‘raft’ that from bridges between receptor proteins and second messengers. Act as centres for assembly of singling molecules
Precursor molecules - for bile/bile acids. Important in digestion and absorption of fat soluble vitamins, vitamin D and steroid hormones
What are the functions of health of triglycerides?
Similar to cholesterol in cell membranes have polar and non polar bits
Highly concentrated energy stores
How are triglycerides carried around the body?
Attached to specialised proteins called lipoproteins
Give the values of Total cholesterol, HDL cholesterol, Total to HDL cholesterol, Triglycerides?
Total cholesterol (ideally <5 mmol/L)
HDL cholesterol (0.9 - 1.6 mmol/L)
Total to HDL cholesterol (ideally <4)
Triglycerides (1.0 - 2.3 mmol/L)
What is atherosclerosis? (basically)
Basically inflammation which happens on the inner walls of the arteries
Where do the earliest changes of atherosclerosis take place?
in the endothelium
What are the first visible lesion in atherosclerosis?
Fatty streaks
As fatty streak progress to intermediate and advanced lesions what do they form?
A fibrous cap that walls of the lesion from the lumen.
What does rupture or ulceration of the fibrous plaque lead to?
Thrombosis and this usually occurs at sites of thinning of the fibrous cap. The thinning is usually due to the continuing influx and activation of macrophages which release proteolytic enzymes at these sites . These enzymes degrade into the matrix resulting in haemorrhage or thrombus formation and occlusion of the artery
What are the 2 types of cholesterol transport?
From the liver to the tissues - mediated by buoyant lipoproteins like VLDL
Back from the liver to the tissues (reverse cholesterol transport) - medicated by HDL
The 2 cholesterol transport mechanism exist in balance, what happens if the balance is disrupted, especially if reverse cholesterol transport cannot match transport to tissues?
cholesterol (especially LDL) will accumulate, resulting in atherosclerosis
What is case control study evidence?
Case-control study: two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute
What is cohort study evidence?
Cohort study: follows a group of people over time, e.g. with reference to risk factors for a disease
What is systematic review evidence?
Systematic review: literature review focused on a research question; tries to synthesize all relevant high-quality evidence
What is meta-analysis evidence?
Meta-analysis: a statistical technique for combining findings from independent studies. (“Research about research”).
