Lecture 24 Flashcards
Serum total protein
Careful
A fall in one protein my be masked by an increase in another
4 causes for elevated enzyme levels in serum
Increased cellular turnover
Cellular proliferation (neoplasia)
Increased enzyme synthesis (induction)
Obstruction to secretion (pancreatic duct)
Isoenzymes or isozymes
Catalyze the same reaction, but differ in their primary structure and/or subunit composition, or quaternary level
Infarction
Necrosis of tissue/organ due to disruption of its blood supply
Can be arterial or venous
Criteria for MI diagnosis (WHO)
Severe chest pain
ECG change
Increase or present of cardiac biomarkers
Enzymes for MI
CK (not in liver)
LDH
AST
Creatine kinase
3 isoforms
2 subunits, M for muscle, B for brain
CK-1 BB: brain and lungs, moves furtherest on electrophoresis
CK-2 MB: myocardium
CK-3 MM: myocardium and skeletal muscle
Negatively charged, move to anode
CK MB
Specific to heart muscle
Peak at 24h then rapidly fall, last 2-3 days
Detect reinfarction
Indicate whether MI occurred
Toal CK
Measure size and intensity of infarction
Peak at 18-30 h, duration 2-5 days
LDH isoforms and places
LDH-1: heart and serum
LDH-5: liver and muscle
Also LDH2-4
LDH 1 serum level increase producing?
1,2-Flip
But 1 2 isoforms also found in erythrocytes, not specific
LDH peaks 40-50 h post MI
The percent of CK MB to total CK
> 3 indicates MI
Non-enzymatic cardiac biomarkers for MI
Myoglobin: detected 1-3 h post MI, peak 4-12 h, highly sensitive for MI, but lack specificity
troponin isoforms: highly specific and sensitive
Troponins 3 regulatory proteins
Troponin T (TnT):specific to heart Troponin I (TnI): specific for myocardial tissues Troponin C (TnC): nonspecific
TnI
Rise 3/5 h
Peak 14/18 h
Remain 5-7 days
TnT
Less specific than cardiac TnI
Rise 3/5 h
Remain 14-21 days
Angina attacks also cause its release
Liver function tests = LFT includes
Total bilirubin Albumin AST and ALT ALP = alkaline phosphatase Gamma GT = gamma-glutamyl transferase
Hepatocyte function tests
Decrease in capacity to synthesize:
Serum albumin
Prothrombin
Fibrinogen
Measure serum ammonia, elevated ammonia indicates hepatic dysfunction
hepatocyte integrity disease is implicated by elevated enzyme activity of :
AST: more sensitive, also for MI
ALT: more specific to liver
LDH-5
Fatty liver disease = FLD
AST:ALT > 2
Caused by alcohol
Hepatitis and NAFLD
High ALT:AST
ALT
Cytosolic enzyme converts reversibly alanine to pyruvate
Amino group used to form glutamate (urea cycle)
Liver biomarker
AST
Cytosolic and mitochondrial isoforms
Reversible conversion of aspartate to OAA
Liver and heart biomarkers
Biliary excretion function diseases are implicated by elevated:
Serum and urine bilirubin, serum bile acid
Membrane bound enzymes (from damage to bile canaliculus): serum ALP, serum GGT, serum 5’nucleotidase
ALP
High concentration in osteoblasts, liver, placenta, and intestinal epithelium, increase during pregnancy and childhood
Pathological increase due to liver disease and certain bone diseases
Decrease associates with hypothyroidism
ALP isoforms
ALPI: intestinal
ALPL: tissue nonspecific: liver, bone, kidney
ALPP: placental
Disease of ALP
Paget’s disease
Deformities of the skull
Liver bile duct obstructions
Gallstones, tumors
Biomarkers: ALP-1, GGT, conjugated bilirubin
GGT
Mainly in liver, less in pancreas and kidney
Cell surface glycoprotein that cleaves gamma-glutamyl amide bond
Biomarker for liver dysfunction and bile duct injury
Acute pancreatitis
Gallstones
Excessive ethanol consumption
Chronic pancreatitis
CF
Hypertriglyceridemia: too many TAG in blood
Long-term excessive ethanol consymption
Biomarkers for pancreatitis
Elevated serum alpha-amylase
Serum lipase: amylase ratio >2: ethanol-induced pancreatitis
Prostate specific antigen (PSA)
Glycoprotein produced by prostate cells
Elevated PSA indicate prostate cancer
Not specific
Alpha-foetal protein (AFP)
Synthesized by foetal liver
Low in adults
High AFP indicates hepatocellular carcinoma
Lack specificity
Similar fcn to albumin, replace by albumin in 12 months
Cancer of liver
Common site for secondary metastases
Jaundice may be first sign of cancer
Liver biopsy performed if w/o blood clotting factors deficiency
