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64 Cards in this Set
- Front
- Back
define hepatitis |
any type of hepatocellular inflammation and necrosis due to various agents (viruses, parasites, bacteria, drug toxicity, alcohol, circulatory failure, autoimmune process, and metabolic disorders) |
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What is fulminant liver failure?
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Severe liver damage leads to secondary problems:
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What are the clinical findings of hepatitis? |
anorexia, weakness and jaundice (but not diagnostic) |
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What is the treatment for hepatitis? |
Supportive treatment: low fat, high carbohydrate diet and follow up care is needed to monitor progress |
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What are the 3 phases of hepatitis? |
acute subacute chronic |
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Acute hepatitis is usually caused by what? |
viruses (hepatitis A, B, C, D, E, G, CMV, EBV and HSV) |
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What is the most common cause of acute hepatitis which is usually short-lived and not chronic? |
hepatitis A (foodborne virus) |
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What is chronic hepatitis? |
destruction of the liver due to immune response to the virus |
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What is hepatitis B? |
HBV is the most common form of chronic hepatitis worldwide |
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Which hepatitis is the most common form of chronic in North America? |
Hepatitis C |
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What is hepatitis C? |
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What are the risk factors associated with hepatitis C? |
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What are the symptoms of hepatitis C? |
many patients are asymptomatic
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What is cirrhosis? |
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What are the most common causes of cirrhosis? |
hepatitis and alcoholism
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What are the clinical manifestations of cirrhosis? |
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What are the two MOST consistent features of advanced liver cirrhosis are what? |
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What should be known about the enzyme activity levels to interpret conditions?
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T/F: enzyme activity in the plasma is not helpful in the indicator of cell damage |
False (enzyme activity is an extremely sensitive indicator of even minor cell damage) |
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Why do enzymes leak from cells? |
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Why would enzyme production be increased? |
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Why would enzyme production be decreased?
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How are enzymes cleared from the plasma? |
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What is the function of aspartate aminotransferase (AST)? |
catalyzes the interconversions of amino acids and 2-oxacids by transfer of amino group transfers the amine group from L-aspartic acid to 2-oxoglutarate to produce L-glutamic acid and oxaloacetate (reversible to make aspartate or glutamate) |
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Where is AST found? |
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What is the preferred specimen for aspartate aminotransferase measurement? |
serum (avoid hemolysis) which the aspartate aminotransferase for about a week at 2-6 degrees (refrigerated) |
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What is the principal for aspartate aminotransferase measurement? |
clinical assays couple oxaloacetate formed by enzyme activity to a second indicator reaction that results in a colored product UV absorbance change |
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What is the function of alanine aminotransferase? |
catalyzes the interconversions of amino acids and 2-oxacids by transfer of amino group transfers of the amine group from L-alanine to 2-oxoglutarate to produce L-glutamic acid and pyruvate (reversible to make alanine or glutamate) |
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Where is ALT found? |
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What does measuring the ALT tell you?
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What is the principle of alanine aminotransferase measurement? |
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What is the preferred specimen for alanine aminotransferase measurement?
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serum (avoid hemolysis) which the aspartate aminotransferase for about a week at 2-6 degrees (refrigerated) |
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What is alkaline phosphatase (ALP)? |
total ALP varies with age and gender (men more than women, and women increase levels during trimester in pregnancy
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Where is alkaline phosphatase found in the body?
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What is alkaline phosphatase useful for? |
differentiating biliary obstruction
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Why would alkaline phosphatase serum levels increase? |
due to cell membrane localized synthesis induced by biliary stasis/duct obstruction, not from cell injury |
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Increased levels of alkaline phosphatase in bone isoenzyme occur in what? |
rapid bone growth (puberty), pregnancy and bone diseases:
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Alkaline phosphatase's activity is optimal at what pH in vivo?
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pH 10
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Alkaline phosphatase's activity is optimal at what pH in vitro? |
depends on the substrate and magnesium concentration |
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What are the activators of alkaline phosphatase? |
divalent ions: Mg, Co, Mn and An |
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The correct ratio of what two divalent ions are required for optimal activity of alkaline phosphatase? |
Mg:Zn |
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What are the inhibitors of alkaline phosphatase? |
phophate, borate, oxalate and cyanide ions |
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What is the most widely used substrate for ALP? |
4-nitrophenyl phosphate (4-NPP) |
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What is the preferred specimen for alkaline phosphatase? |
fasting samples of the serum or heparinized plasma and no hemolysis |
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What should be avoided in specimens collected for alkaline phosphatase? |
the specimen should NOT have citrate, oxalate (inhibits the enzyme) or EDTA anticoagulants (binds and inactivates divalent ions) |
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What happens to alkaline phosphatase in the specimen over time in storage? |
its activity increases |
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What are some techniques to differentiate the ALP isoenzymes? |
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Describe electrophoretic separation at alkaline pH for ALP differentiation. |
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Describe heat inactivaton for ALP differentiation. |
example: if 80% of enzyme activity is present after 19 mins, then 80% is liver enzyme and 20% was bone |
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Describe chemical inhibition for ALP differentiation |
varying resistance to inactivation by urea placental (most resistant) > liver > bone (least resistant) |
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Describe immunochemical techniques |
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What is gamma glutamyl transferase? |
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What is the role of GGT? |
role in glutathione metabolism in the liver and aa absorption in nephrons and in the intestine |
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If the GGT is elevated, what does it indicate? |
almost always indicates liver damage: obstruction, necrosis and neoplasms
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Concentration of GGT vary with what? |
gender but not age |
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GGT synthesis is induced by what?
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chronic alcohol and/or drug ingestion |
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Which screening test has been advocated for alcohol abuse? |
GGT (although alcohol related GGT levels will return to normal 14-16 days after cessation of alcohol consumption) |
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What is gamma glutamyl transferase levels used for? |
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What is the principle for measuring GGT?
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the assay utilize gamma-glutamyl-p-nitroanilide as a substrate or donor and glycylglycine as the amino acid receptor which is a coupled reaction and observed spectrophotometrically |
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What is the specimen preferred for GGT analysis?
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serum preferred, EDTA plasma acceptable, avoid hemolysis |
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What is 5'-nucleotidase? |
localized in microsomes and cell membranes |
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What is 5'-nucleotidase useful for? |
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What is the principle of the assay used to measure 5'-nucleotidase?
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The principle of the assay used to measure 5'-nucleotidase will vary depending on the technique instrumentation and substrate being used. The enzyme will react only with the nucleoside 5'-phosphate. Adenylate monophosphate or PMP is used as a substrate. The 5'-nucleotidase removes the phosphate to produce adenosine. This reaction is coupled to two additional enzymatic reactions in order to obtain a measurable product. The adenosine is the adenosine deaminase seen which results in the formation of ammonia. The ammonia then reacts with two oxoglutarate and NADH with the help of the enzyme glutamate dehydrogenase to produce glutamate and NAD. The conversion of the NADH to NAD can be measured spectrophotometrically
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What are the specimen preferred for 5'-nucleotidase analysis? |
serum preferred, hemolysis avoided |