Chemical Pathology 17 - EMQs on Enzymes, Chemistry Flashcards
What type of technetium is used in bone scans vs thyroid scans?
Bone scans: Tc bisphosphonate (radioactively labelled bisphosphante)
Thyroid scans: Tc pertechnate
Which type of nuclear medicine test is most useful for identifying Ca cells themselves?
FDG-PET
**shows metabolic activity of cancer cells**
Which type of nuclear medicine test is most useful for identifying primary neuroendocrine tumours (eg insulinomas)?
Gallium 68 dotatate PET and CT (identifies somatostatin receptor)
**this is not FDG PET**
Which type of nuclear medicine test is most useful for parathyroid scans?
Sesta MIBI scan
Which type of nuclear medicine test is most useful for investigating for a phaeochromocytoma?
MIBG (looks for phaeo mets)
Recall the timeline of elevation of troponin I, AST and LDH elevation post-MI
Troponin I - first few hours
AST - first day
LDH - over first 5 days
Which LFT result will be most deranged in obstructive jaundice?
ALP
Descrine the pathophysiology of alcoholic hepatitis causing portal hypertension
Alcoholic hepatitis –> hepatocyte death
The person becomes ill and recovers, and the hepatocytes regenerate. However, rather than regenerating as before, they form a NODULE
This nodule disrupts hepatic micro-architecture between the portal vein and the central vein
If enough nodules appear, this increases pressure in the portal vein –> portal HTN
Which enzymes are most elevated by gallstones vs viral hepatitis and why?
Gallstones: ALP - stones tend to cause most damage near portal triad, where more ALP is made
Viral hepatitis - ALT - the virus tends to affect hepatocytes around the central vein the most, where ALT is predominantly produced
What marker is raised in paget’s disease of the bone?
ALP
What marker is raised in osteomalacia?
ALP
Which of these is raised after acute MI?
AST
Which enzymes increase after an MI?
- troponins - msot sensitive, rises within 6 hours
- CKMB
- AST- over a day
- LDH- over 5 days
What is another name for prostate specific antigen?
acid phosphatase
What is ALP in priimary hyperparathyroidism?
Tends to be normal
What is Vitamin D like in primary hyperparathyoridism?
LOW
High PTH–> consumes inactivated Vitamin D (this is what is measured in the blood rather than activated vitamin D)
Between urea and creatinine which one goes up first rapidly in acute renal failure?
what about chronic renal failure?
urea
creatinine (c for chronic, c for creatinine)
What is a marker of glucose control over the last 3 weeks?
FRUCTOSAMINE
What is the histology of a brown’s tumour?
giant multinucleate cells
what does this chest x ray show?
bilateral hilar lmphadenopathy
how does sarcoidosis cause hypercalcaemia?
sarcoid tissue (macrophages) expresses ectopic 1 alpha hydroxylase
this produces activated vitamin D
which increases calcium absorption
this suppresses PTH
**gives you seasonal hypercalcaemia - only in the summer where you have enough sunlight**
What produces ALP?
osteoblasts
What test is used to diagnose paget’s disease?
technetium bone scan (tc bisphosphonate)
If urine dipstick is poistive for blood but negative for erythrocytes what does that mean?
myoglobinuria eg due to rhabdomyololysis
what enzyme abnromality can mumps cause?
mumps causes parotitis which can cause raised serum amylase!!!
