Enzymes (part two) Flashcards by Mariah Kinman

What are the 5 major liver enzymes

Aspartate aminotransferase
Alanine aminotrasferase
Alkaline phosphatase
Gamma-glutamyl transerase
Cholinesterase

How well did you know this?

Not at all

Perfectly

Aspartate Amiontransferase (AST) 
- Three biological sources

Heart
Skeletal Muscle
Liver
(4. Kidney)

How well did you know this?

Not at all

Perfectly

Aspartate Amiontransferase (AST) 
- typical appearance, peak, and return to normal after myocardial infarction

Rises within 12 hours after onset of chest pain; peaks at 18-24 hours; normal within 4-5 days

How well did you know this?

Not at all

Perfectly

Aspartate Amiontransferase (AST)
-Two liver diseases that give rise to the greatest elevations

Liver (hepatocellular) Disease

Viral Hepatitis
Liver carcinoma

How well did you know this?

Not at all

Perfectly

Aspartate Amiontransferase (AST) 
- One muscular disease in which AST is elevated

Skelatal Muscle Disease (Muscular Dystrophy)

How well did you know this?

Not at all

Perfectly

Aspartate Amiontransferase (AST) 
-If hemolyzed specimens are unacceptable

UNACCEPTABLE

-due to high intracellular concentration of AST

How well did you know this?

Not at all

Perfectly

Principle biological source of ALT

Liver

How well did you know this?

Not at all

Perfectly

alanine aminotransferase (ALT)
-relative use in the diagnosis of liver disease, compared to AST

useful in the diagnosis of acute and chronic liver disease; parallels the rise in AST activity

How well did you know this?

Not at all

Perfectly

alanine aminotransferase (ALT)
-liver diseases in which it is elevated

ALT higher and persists longer than AST in hepatitis

How well did you know this?

Not at all

Perfectly

alanine aminotransferase (ALT)
-Hemolysis acceptibility?

NO HEMOLYSIS

How well did you know this?

Not at all

Perfectly

Alkaline Phosphatase (ALP) 
- four principal biological sources of total ALP

liver, bone, intestine, placenta

How well did you know this?

Not at all

Perfectly

Alkaline Phosphatase (ALP) 
- Hepatobiliary diseases in which ALP is increased

biliary obstruction, hepatitis, cirrhosis, infectious mono, and metastic carcinoma

How well did you know this?

Not at all

Perfectly

Alkaline Phosphatase (ALP)
- The hepatobiliary disease which gives rise to ALP's highest elevations

Biliary Obstruction

How well did you know this?

Not at all

Perfectly

Alkaline Phosphatase (ALP) 
- Bone diseases in which ALP is increased

Bone tumors, Paget’s Disease, Rickets, osteomalacia, hyperparathyroidism, and healing fractures

How well did you know this?

Not at all

Perfectly

Alkaline Phosphatase (ALP)
- Two bone diseases which tie rise to ALP's highest elevations

Bone tumors and Paget’s Disease

How well did you know this?

Not at all

Perfectly

Alkaline Phosphatase (ALP) 
- If hemolyzed specimens are unacceptable

Gross hemolysis NOT acceptable (slight ok but must be documented)

How well did you know this?

Not at all

Perfectly

Alkaline Phosphatase (ALP)
- Principle of the Bowers and McComb procedure using p-nitrophenylphosphate

reference method; kinetic method that uses pNPP as substrate and measures the rate of p-nitrophenoxide release in AMP buffer

How well did you know this?

Not at all

Perfectly

Which specific isoenzymes may be distinguished using the heat stability, urea denaturation, amino acid inhibition, and electrophoretic techniques

Alkaline Phosphatase (ALP)

How well did you know this?

Not at all

Perfectly

Alkaline Phosphatase (ALP)
- Why the reference range is higher in children than in adults

due to rapid bone growth

How well did you know this?

Not at all

Perfectly

gamma-glutamyltransferase (GGT)

-two principle biological sources

primarily liver, also kidney

How well did you know this?

Not at all

Perfectly

gamma-glutamyltransferase (GGT)

-degree of elevation used in the differential diagnosis of hepatocellular VS biliary tract disease

Elevation up to 5X ULN in biliary tract disorders; lesser elevation (2-5X) in viral hepatitis or active cirrhosis

How well did you know this?

Not at all

Perfectly

gamma-glutamyltransferase (GGT)

-clinical usefulness in the diagnosis and monitoring of chronic alcoholism

GGT is induced by alcohol and other drugs; used as a marker to check for abstinence from alcohol

How well did you know this?

Not at all

Perfectly

cholinesterase (ChE) in vivo reaction it catalyzes

Both enzymes hydrolyze choline esters to form choline and the corresponding fatty acid at the neuromuscular junction

How well did you know this?

Not at all

Perfectly

Three clinical applications of measuring ChE activity

1 assess exposure to organophospahtes found in insecticides and nerve gas
2 check how patient will react to general anesthesia
3 assess presence of cirrhosis, hepatitis, liver carcinoma (due to decreased production)

How well did you know this?

Not at all

Perfectly

Sources of AChE (acetylcholinesterase)

Red blood cells and central nervous system

Sources of cholinesterase (ChE)

Liver, white matter of brain, serum

``` creatine kinase (CK) -in vivo reaction it catalyzes ```

Catalysis for ATP formation and phosphorylation of creatine in energy production or usage

``` Creatine Kinase (CK) -three principle tissue sources ```

skeletal and cardiac muscle, brain

``` Creatine Kinase (CK) -dimeric composisition and sources of its three isoenzymesm ```

composed of two subunits (M and B); Isoenzymes formed: CK-MM, CK-MB, CK-BB

``` Creatine Kinase (CK) -typical apprearance, peak, and return to normal after a myocardial infarction ```

Rises 3-8 hours after the onset of chest pain (1st to rise) Activity peaks at 10-36 hours Levels return to normal in 3-4 Days

``` Creatine Kinase (CK) -one muscular disease that gives rise to CK's highest elevations ```

Duchenne's Muscular Dystrophy (50X ULN)

``` Creatine Kinase (CK) -cerebral diseases in which CK is elevated ```

Cerebral vascular accident (CVA), stroke, cerebral ischemia

``` Creatine Kinase (CK) -principle of the Oliver and Rosalki method ```

Analytical procedure for total CK; Increase in absorbance as NADP is oxidized is measured at 340 nm

Lipase (LPS) | -principle biological source

Pancreas

Lipase (LPS) | -two diseases in which LPS is elevated

Acute pancreatitis and chronic pancreatitis

Lipase (LPS) | -a comparison between the usefulness of LPS and AMS measurements in the diagnosis of pancreatitis

levels parallel AMS appearance, but LPS is more specific than AMS

Lipase (LPS) | -principles of the turbidimetric/nephelometric procedures

Olive oil emulsion is hydrolyzed by LPS, causing a DECREASE in turbidimetry

Lipase (LPS) | -principle of coupled enzymatic analytical procedure

LPS hydrolyzes fatty acids to form free glycerol which is quantitated colorimetrically

Clinical usefulness of performing acid phosphatase (ACP) measurements

used to diagnose diseases of the prostate; can also do a prostatic acid phosphatase (PAP) and PSA

Glucose-6-phosphate dehydrogenase (G-6-PD) | -biological sources

RED BLOOD CELLS, adrenal cortex, lymph nodes, thymus, spleen

Glucose-6-phosphate dehydrogenase (G-6-PD) | -disease state associated with LOW levels of G-6-PD

hemolytic anemia

four major coenzymes used in electron transfer reactions commonly employed in enzyme assays in the lab, including specific wavelength for measurement

NAD, NADH, NADP, NADPH; wavelength 340

Clinically significant enzymes/lab findings | -myocardial infarction

I CK, I CKMB, I AST, I LD

Clinically significant enzymes/lab findings | -liver (hepatocellular) disease

AST and ALT

Clinically significant enzymes/lab findings | -Liver (hepatobiliary) disease

ALP and GGT

Clinically significant enzymes/lab findings | -bone disease

ALP

Clinically significant enzymes/lab findings | -brain disease

CK-BB, CK

Clinically significant enzymes/lab findings | -prostate cancer and hypertrophy

ACP

Clinically significant enzymes/lab findings | -acute and chronic pancreatitis

LPS AMS

Clinically significant enzymes/lab findings | -muscle disease and muscular dystrophy

CK-MM CK ALS

``` Lactate Dehydronase (LD) - seven principle biological sources ```

Ubiquitous! 1. Brain 2. RBCs 3. WBCs 4. Kidney 5. Liver 6. Lung 7. Cardiac 8. Skeletal muscle

``` Lactate Dehydronase (LD) -after myocardial infarction ```

- 10X increase above UNL - increase 8-18 hours after onset of chest pain - peaks 48-72 hours - returns normal 6-10 days - ELP shows LD1 > LD 2 or "flipped pattern"

``` Lactate Dehydronase (LD) -liver disease which it is elevated ```

Hepatobiliary disease

``` Lactate Dehydronase (LD) - liver disease that gives rise to the greatest elevation ```

Metastatic cancer

``` Lactate Dehydronase (LD) - two types of anemia where it is elevated ```

Megaloblastic anemia | Pernicious anemia

``` Lactate Dehydronase (LD) -hemolysis acceptable? ```

Acceptable, but make a comment. Hemolysis increases LD in vivo, and in vitro.

Aldolase (ALS) | - three principle biological sources

- skeletal - muscle - brain

Aldolase (ALS) | -one disease state where it is elevated

Skeletal muscle diseases, such as muscular dystrophy

Amylase (AMS) | - two principle biological sources

1. Pancreas 2. Salivary glands 3. Macroamylase

Amylase (AMS) | - clinical significance of macroamylase

AMS bound to IgG or IgA, causing an increase in total AMS without apparent disease

Amylase (AMS) | - clinical significance of measurements in diagnosis of acute pancreatitis, chronic pancreatitis, and mumps

???

Amylase (AMS) | - what method measures amount of sugars formed from hydrolytic activity of AMS

Saccharogenic

Amylase (AMS) | - what method uses dye-labeled starch substrates; as AMS hydrolyzes the starch, an increase in color is quantified

Chromilytic

Amylase (AMS) | -method that measures decrease in starch substrate concentration as AMS works on starch.

Amyloclastic Assays

Amylase (AMS) | -method that is a glucose coupled reaction and a hexokinase coupled reaction

Enzymatic Assays

Enzymes (part two) Flashcards

(65 cards)