Question | Answer |
List the two major groups of nitrogen containing compounds | Proteins
Nucleic Acids |
Convert Urea to a BUN, and BUN to Urea. | BUN x 2.5 (60/24) = Urea
Urea x 0.49 (24/60) = BUN |
Describe the synthesis of urea in the body | Liver breaks down amino acids to form ammonia. Ammonia then enters the Urea Cycle where Urea is formed. |
What three conditions will have increased serum BUN | Pre-Renal: reduced renal flow (dehydration, high protein diet)
Renal : Reduced renal function (acute glomerulonephritis, tubular necrosis)
Post-Renal: Obstruction of urine flow (kidney stones) |
What is the reason for the usage of the BUN/Creatinine ratio? | The levels can indicate where a problem exists in the body |
What conditions will have a low BUN/Creatinine ratio? | BUN is diminished. Creatinine is normal. -> acute renal tubular necrosis, malnutrition, low protein diet, or over hydration. |
What conditions will have a high BUN/Creatinine ratio? | BUN is high. Creatinine is normal. -> reduced renal perfusion, obstructive uropathy, shock, GI bleeding, dehydration, high protein diet.
High levels of BUN and Creatinine is a kidney problem |
State the basic principle of enzymatic BUN methodologies | Based on the preliminary hydrolysis of urea with urease to generate ammonia. |
Briefly describe the synthesis of uric acid in the body: | Uric acid comes from the breakdown of purines (adenosine and guanine) |
Define Hyperuricemia and give a cause of the condition: | Elevation of uric acid greater than 7.0 mg/dl
Gout: monosodium urate forms in the joints and tissues, patients with carcinomas, arthritic attack. |
Define Hypouricemia and give a cause of the condition: | Uric acid levels less than 2 mg/dl
Severe hepatocellular disease. Defective renal tubular reabsorption. |
State the basic principle for the Phosphotungstic Acid (PTA) uric acid methodology | based on the reaction of uric acid with PTA to form tungsten blue in an alkaline medium. Bi-product formed is hydrogen peroxide. |
State the basic principle for the uricase method of uric acid methodology | uricase acts on uric acid to produce allantoin, hydrogen peroxide, and CO2. The reaction is measured in kinetic or equilibrium mode. |
State the basic principle for the HPLC method of uric acid methodology | uses ion-exchange or reversed-phase columns to separate and quantify uric acid. |
Describe the formation of Creatinine in the body | Creatine is formed in the kidney, liver, and pancreas. Sent to the muscles and brain. Phosphorylation by CK locks Creatine into the cells. Conversion of Creatine to Creatinine. Free Creatinine is excreted in the urine at a constant rate |
List two conditions that lead to increased Creatinine levels in blood serum | Severe muscle disease
Hypertension |
State and explain the chemical method used in Creatinine determination | Jaffe reaction: Creatinine reacts with picrate in alkaline medium to yield orange-red complex |
State and explain the enzymatic method used in Creatinine determination | Creatininase (indicator system)
Creatininase and creatinase (oxidized reactant or indicator sys)
Creatinine deaminase (oxidized reactant) |