Chem path 14 - Enzyme EMQs (Karim Meeran) Flashcards
At what rate do you produce creatinine?
At a fixed rate
Where is AST found in heart?
Myocytes
How long does it take for AST to go up after MI and how long does it stay up?
2-5 days
What are the enzymes which increase following an MI?
AST, troponin, CK-MB, LDH, myoglobin
When does LDH peak post MI?
5-7 days
When do you measure troponins?
2 measurements, 12 hours apart, should go up. A negative troponin is also useful.
How do you prevent the progression to renal failure in rhabdomyolysis?
IV bicarbonate which allows them to urinate out all the CK which is the cause of the renal failure
What is the relationship of AST and ALT to either viral hepatitis or chronic alcoholic cirrhosis?
ALT higher than AST in pts with viral hepatitis
AST higher than ALT in pts with chronic alcoholic cirrhosis
What is another name for acid phosphatase?
PSA
In primary hyperparathyroidism, what happens to the level of vitD?
it is low
Why is the level of vit D low in primary hyperparathyroidism?
PTH activates 1a hydroxylase meaning that vitamin D is consumed (i.e. it is activated)
What are assays for vitamin D measuring?
25-OH cholecalciferol (Calcidiol)
What happens to the urea and creatinine levels in acute and chronic renal failure?
In acute renal failure caused by dehydration, UREA will rise the most
In chronic renal failure caused by a fall in GFR, CREATININE will rise the most
what is significant about CKD caused by diabetes?
It is much more rapidly progressive than other causes of renal impairment
What creatinine cut off level is significant in diabetes related CKD?
A creatinine >200umol/L as you are likely to reach end stage renal failure within a year
Is a high creatinine an indication for dialysis?
No
What are the indications for dialysis?
- Hyperkalaemia (refractory)
- refractory fluid overload
- Acidosis (treated with sodium bicarbonate)
- Pulmonary oedema
- Uraemic symptoms (encephalopathy, pruritis, nausea, malaise, pericarditis)
- CKD Stage 5 (GFR <15l/min)
What is a marker for blood glucose control over the last 3 weeks?
Fructosamine (useful in pregnancy)
Which two markers are increased in Paget’s disease?
ALP and osteocalcin due to increased activity in both osetoblasts and osteoclasts
what is a key feature of Paget’s disease?
A bowed tibia (will be warm as well) (others will be asymptomatic, high risk of fracture)
What is the treatment for Paget’s?
Bisphosphonates (only if painful disease) - bone formed with calcium bisphosphonate is unable to be degraded by osteoclasts
Which scan is performed in all oncology patients to look for bony metastases?
Technetium bisphosphonate scan (NOTE: kidneys always show up on this scan as the label is excreted by them)
What is a technetium 99 scan and when is it used?
It is used to look for iodine uptake by the thyroid gland
What is an FDG-PET scan used for?
To detect abdominal mets. FDG is a non specific marker as glucose is taken up by every cell but cancer cells are more active so have higher uptake.
