KIDNEY FUNCTION TEST part 2 Flashcards
This refers to the concentration of urea as a whole molecule not just by the nitrogen portion.
Urea concentration test
The values of Urea is often obtained via?
Direct methods
What is the equation that is used to convert BUN in the equation?
Urea concentration = BUN x 2.14
How is 2.14 obtained?
It is derived from:
- molecular weight of 2 nitrogen atoms in urea.
The stability of Urea in Serum can lasts up to?
24hrs at room temp
several days: 2 - 6°C
2 - 3 months when frozen
These substances inhibits the urease enzyme
Fluoride and Citrate
This is contradicted in the assay
Double oxalate
If urea in serum is left standing for a prolonged period, what would happen?
Due to deamination, the NH3 concentration would increase 2-3 times.
Do lipemia and hemolysis interfere with urea concentration test?
No.
TRUE OR FALSE:
Ammonium containing anticoagulant should not be used in urea concentration test.
TRUE
TRUE OR FALSE:
In Urea concentration test, fasting sample is required.
FALSE; Not required
This method measure urea by converting it first to ammonium ions using urease.
Indirect method / Enzymatic
What happens in the initial reaction of indirect/ enzymatic method?
The urease converts urea to ammonium ions and carbonate ions/ carbon dioxide
What happen in the secondary reaction of indirect/ enzymatic method?
It quantifies ammonium ions that formed after the initial reaction
Where in urease often derived?
Jack bean meal
What is the color dimercuric ammonium iodide.
Yellow-orange
This is the conversion of unionized urea into ammonium and bicarbonate and it measures the increase in conductivity rate.
Beckman BUN analyzer
Beckman BUN analyzer is based from?
Conductivity generated when NH4 ions and HCO3 are produced from the reaction of urease on urea.
The Beckman BUN analyzer in monitored by?
Conductivity electrode
Urastrat Strip Method is based on?
Chromatography
What travels up the urastrat strip?
Serum or plasma
What are the reactants involved in Urastrat Strip Method?
Urease
K2CO3
BGC-Tartaric acid
What is the formula of BUN mg/dL every 30 minutes?
Height of color change (mm) x 5 + 10
What is the reference method for DAM?
Fearon
If Urea is combined with diketone/DAM + strong acid + heat. What would be the product?
An unstable photosensitive yellow complex known as DIAZINE.
Diazine can be measured at what wavelength?
540 nm
How is diacetyl produced?
Diacetyl monoxime hydrolyzes in the presence of acid.
What substance does Diacetyl reacts to produce a diazine derivative?
Urea
What is the color of a diazine derivative?
Pink/Yellow
What is the reference method for Urea?
Isotope Dilution Mass Spectrometry
It is a biochemical abnormality pertaining to increase NPN compounds which is creatinine and Urea defining GFR effect,
Azotemia
This refers to the increased plasma urea, creatinine and uric acid concentration. It has an involvement such as renal failure.
Uremia
