enzymes

Answer 1

The Miachaelis-Menten constant = concenetration of a substarte at which the reaction velocity is 50% of the maximum

Question 2

When is ALP found

Answer 2

Bone - fracture, Page’ts, osteomalacia, rickets, HPT, renal osteodystrophy

Intrahepatic / extrahepatic bile ducts -
Intestine - bowel disorders

Question 3

When is raised ALP physiologically normal?

Answer 3

During pregnancy - released from placenta
or children

Question 4

Clinical approach to ALP

Answer 4

Check LFTs - if normal, check vit D

Answer 5

Body breaks down bone to release phosphate, hence ALP is released

Question 6

ALT vs AST - where do they come from?

Answer 6

AST can come from heart, liver, muscle, kidney, whereas ALT comes mainly from the liver

However there are better biomarkers for the other organs so we used these other ones

Question 7

ALT raise meaning

Answer 7

Toxins - hepatocyte injury - alcohol, paracetamol overdose
Liver ischemia after heart attack
Hepatitis

and some other things - see

Question 8

How can you test for intestinal ALP

Answer 8

Fasting ALP - if it returns to normal after being high, it suggests it’s coming from the intestines

Question 9

Where is gamma glutamyl transferase released?

Answer 9

Liver/biliary system

Answer 10

Rifampicin

Question 11

LDH can be raised due to

Answer 11

Lymphoma
Haemolysis
Germ cell testicular cancer - poor prognosis if LDH is high
Myositis
Hepatic disease

Question 12

Serum amylase

Answer 12

in exocrine glands

If high - pancreatitis; only high in acute
perforated duodenal ulcer
bowel obstruction secondary to

Salivary gland - stones, infection

Macroamylase - immunoglobulin binds to amylase and makes renal excretion difficult - request amylase isoenzymes

Question 13

Does serum amylase cause

Answer 13

measure calclium, glucose, lactate

Question 14

CK due to

Answer 14

Skeletal muscle- rhabdomyolysis, myositis, polymyositis, severe exercise, myopathy

can cause acute tubular necrosis due to getting stuck in kidneys

???

Question 15

What do we measure troponin for?

Answer 15

Cardiac specific troponin-I; injury to cardiac myocyte

primary - heart attack, myocarditis, cardiomyopathy, aortic dissection

Secondary cardiac injury

Question 16

CK-MB

Answer 16

Is a specific isoform of CK-MB

Answer 17

rises within 2 hours
peaks at 12 hours

male <35ng/L
female <16ng/L

returns to normal 5-10 days later

Question 18

What change in troponin means ACS

Answer 18

50 percent increase or decrease is suggestive of cardiac myocyte injury due to ACS

Question 19

Narrowing of coronary arteries due to an atherosclerotic plaque can result in

Answer 19

STEMI
NSTEMI
Unstable angina
Stable angina

Question 20

Cardiac chest pain + STEMI management

Answer 20

PCI

STEMI - subendocardial layer and myocardium

Question 21

NSTEMI

Answer 21

Subendocardial layer

do serial troponins and check ref range, or if there is more than a 50% change in results

VT + VF = complications so do serial ECGs too

Question 22

Unstable angina

Question 23

BNP and NT=proBNP

Question 24

Explain

Answer 24

cardiomyocyte stretch - BNP transcribed within 1 hr, caues you to PEEEEE to offload extra volume

We measure NT-proBNP, produced in equamolar amounts

NT-proBNP is stable for longer so can be measured 7 hrs down the line

Question 25

Which drug gives you false BNP readings? What do you measure instead?

Answer 25

Entresto -

Question 26

When might you measure BNP? If it’s high, what do you do next?

Answer 26

E.g. if a pt comes in with shortness of breath for heart failure

If it’s high, what do you do next? echocardiogram

Question 27

what’s high in chronic pancreatitis?

Answer 27

Faecal elastase