Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
24 Cards in this Set
- Front
- Back
- 3rd side (hint)
Which lipoprotein causes "milky" plasma blood cells?
|
Chylomicrons cause milky plasma; when a sample is refrigerated, the CM will form a creamy layer of the top of the sample. VLDL causes cloudy plasma, which is distinct from the milky/creamy plasma that forms during the refrigeration test
|
|
|
Which apolipoprotein specific chylomicrons?
|
B-48 is found only in chylomicrons
|
|
|
Was the predominant apolipoprotein low-density lipoprotein?
|
B-100 is the key apolipoprotein in LDL. It is also found in VLDL
|
|
|
where does high density lipoprotein(HDL) migrate on protein electrophoresis?
|
HDL migrates in the alpha-1 fraction
|
|
|
Which alipoprotein activates the enzyme lipoprotein lipase (LPL)?
|
apoC-2
|
|
|
31-year-old completes a half iron triatholon , submits blood sample for research protocol on the effects of vigorous exercise on lipids. His triglycerides(TG) are found to be elevated at 232mg/dl. He consumed almost no fat during the race and ate a carbohydrate rich breakfast. Explain?
|
Vigorous exercise can generate free glycerol plasma, interfering with enzymatic triglyceride measurement. To correct for this, a blanking procedure should be performed prior to measuring the subject’s .
|
|
|
Reviewed the electrophoretic patterns of the lipoproteins :
CM, LDL, V LDL, HDL |
Cm=origin, VLDL=pre-beta, LDL=beta, HDL=alpha-1
|
|
|
State the Friedewald formula for estimating LDL in mg/dL, state when a direct method would be more accurate?
|
LDL = TC - HDL - TG/5.0 (mg/dL)
if triglycerides are greater than 400 mg/dL then a direct measurement |
|
|
Reviewed the cholesterol oxidase method of measuring cholesterol, how would ascorbic acid result in a falsely low value?
|
ascorbic acid consumes hydrogen peroxide, a reaction product , which is converted to H2O and adye measured at 500nm. less H2O2 would result in less finial product, in this case the dye
|
|
|
what is the role of lipoprotein lipase?
|
LPL hydrolyses triglycerides from CM and VLDL. Type 1 hyperlipoproteinemia in the Fredrickson Classification scheme is a deficiency of LPL. This is autosomal recessive disorder. With CM poorly handled in circulation, these patients have milky plasma
|
|
|
an overnight fast ensures that which lipoprotein is cleared from plasma in a normal individual?
|
CM should be cleared by 9-12 hours of fasting
|
|
|
why is EDTA the preferred anticoqagulant for cholesterol panel when cholesterol and triglycerides levels in plasma are about 3% lower in EDTA- preserved specimens than in serum samples?
|
EDTA retards oxidative and enzymatic changes that occur in lipoproteins during storage.
|
|
|
Friedewald formula for estimating LDL
|
LDL-cholesterol= total cholesterol -HDL-cholesterol - TG/5
If TG are greater than 400mg/dL then a direct measurement of LDL is more accurate |
|
|
a patient with dysbetalipoproteinemia has elevated levels of what lipoprotein? what electrophoretic feature helps distinguish this disorder from others?
|
beta -VLDL ; on protein electrophoreesis a broad band between VLDL and LDL is present and distinctive; this is type 3 in the fredrickson scheme
|
|
|
according to the AFCAPS trial, which apolipoprotein was found to be the single best lipid, lipoprotein or apolipoprotein measurement to predict coronary artery disease risk?
|
apoB
|
|
|
what is the effect of age on cholesterol concentrations in both sexes?
|
cholesterol concentrations increase with again both sexes starting in early adulthood
|
|
|
total cholesterol of 287mg/dL, HDL of 22mg/dL, TG of 400mg/dL
LDL? |
LDL-cholesterol= total cholesterol -HDL-cholesterol - TG/5
287-22-(400/5)=185mg/dL |
|
|
|
|
|
|
|
|
|
|
premature coronary artery disease is most clearly associated with which types of lipoproteinemia in the Fredrickson Classification?
|
2a&2b=LDL
3=IDL; abdominal and femoral arteries |
|
|
2A (heterozygous and
homozygous familial hypercholesterolemia) |
mutation of LDL receptor gene on chromosome 19
|
|
|
cholesterol ratio is used to screen for type 3 hyperlipoprotein/dysbetalipoproteinemia?
|
VLDL/TG
normal ratio is 0.2 , in dysbetalipoproteinemia patients this ratio is >0.3 with all their excess VLDL |
|
|
what vitamin deficiency is most pronounced in abetalipoproteinemia and why?
|
vitamin E requires CM for adsorption, VLDL for transport and LDL for delivery into the cells
without the apoB proteins, there is no B-48(this is the major protein in CM-no B-48, no CM based absorption of vitamin E); these patients also are deficient in B-100, a key protein in both LDL and VLDL, so these proteins can not be properly synthesized; patients can develop retinal and peripheral nerve deficits if vitamin E is not replaced |
|
|
25yom body builder has HDL 12mg/dL, HEENT exame is normal; what do you suspect?
|
classic anabolic steroid use; the normal HEENT examination ruled out the orange tonsils of Tangier disease
This, defined as HD L<35 mgldL, is an independent risk factor for premature atherosclerosis . Ahigh HDL, greater than 70 mg/dL, i sprotective. Tangier disease is an autosomal recessive disorder of lipid metabolism characterized by low cho-lesterol, normal to increased TG, absent HDL, an dabsence of APO-A 1 . Cholesterol esters deposit in th etonsils, lymph nodes, vasculature, and spleen, andcorneal opacities develop. HDL cholesterol may als obe reduced by smoking, obesity, sedentary lifestyle,and anabolic steroids |
|