Chemical Examination of Urine (DJIP) Flashcards
Major types of reagent strips
- Multistix
- Chemstrip
Source of errors of using reagent strips
-Unmixed specimen o Keeping strip in urine too long o Excess urine on strip o Imprecise timing o Light source o Reagents strips and color charts from different manufacturers are not interchangeable o Sample must be at room temperature
True or false. Enzymatic
reactions are temperature dependent
true
pH of first morning urine
pH 5.0-6.0
Defects in renal tubular secretion and reabsorption of
acids and bases
—renal tubular acidosis
Normal pH range
4.5-8.0
pH condition observed after meals
Alkaline tide
Chemical finding most indicative of renal disease
protein
Causes of acidic urine
·Emphysema · Diabetes mellitus · Starvation · Dehydration · Diarrhea · Acid producing bacteria (E. coli) · High protein diet · Cranberry juice · Medications: Methenamine mandelate, fosfomycin tromethamine
Causes of alkaline urine
· Hyperventilation · Vomiting · Renal tubular disease · Urease producing bacteria · Vegetarian diet · Old specimens
Clinical proteinuria level
≥ 30 mg/dL
3 major categories of proteinuria
- prerenal
- renal
- postrenal
Kind of protein increased in Intravascular hemolysis
Hemoglobin
Kind of protein increased in muscle injury
myoglobin
Kind of protein increased in multiple myeloma
bence-jones protein
bence jones protein coagulate at what temp
40-60C
bence jones protein dissolve at what temp
100
kind of renal proteinuria when there are:
- Fanconi syndrome
- Toxic agents/heavy metals
- Severe viral infections
Tubular proteinuria
Due to vertical posture
Orthostatic (Postural) proteinuria
Due to increased pressure on renal vein
Orthostatic (Postural) proteinuria
solution to postural proteinuria
empty bladder before going to bed
and obtain a first morning specimen, then
obtain a second specimen after a few hours in
vertical position
-Diabetic nephropathy
- Leads to reduced glomerular filtration and
renal failure
Microalbuminuria
kind of proteinuria in Bacterial and fungal infections (UTI) [produce
exudates]
Postrenal proteinuria
Reagent of Multistix (protein)
:tetrabromphenol blue
Reagent of chemstrip (protein)
3’,3’’,5’,5’’-tetrachlorophenol-
3,4,5,6-tetrabromosulfonphthalein
sources of false positive when using a reagent strip
- Highly buffered alkaline urine
- Pigmented sx (phenazopyridine)
- 4° ammonium compounds (detergents)
- Antiseptics, chlorhexidine
- Loss of buffer due to prolonged exposure
- High specific gravity
sources of false negative when using a reagent strip
- Proteins other than albumin
- Microalbuminuria
Reagents of micral test
Gold-labeled antibody
· B-galactosidase
· Chlorophenol red galactoside
confirmatory test for albumin
Sulfosalicylic Acid Precipitation Test (SSA)
Most frequent chemical analysis
glucose
Reagent strip rxns for glucose
Blue-green to orange-red color
tablet used for glucose measurement
clinitest
true or false. Tablets are very hygroscopic
true
Intermediate products of fat metabolism
ketones
inadequate intake of carbohydrates
starvation
inadequate
absorption of carbohydrates
Malabsorption/pancreatic disorders
reagent strip reactions for ketones
purple
tablet used for ketone test
acetest
give the Clinical significance: - Due to trauma or damage of genitourinary organs Renal calculi Glomerulonephritis Pyelonephritis Tumors Trauma Exposure to toxic chemicals Anticoagulants Strenuous exercise Menstruation
hematuria
give the clinical signifance:
Heme-containing protein found in muscle tissue
- Clear red-brown urine
- Suspected in patients with conditions associated
with muscle destruction (eg. Rhabdomyolysis)
myoglobinuria
Reagent strip reactions (blood)
o Pseudoperoxidase activity of hemoglobin to catalyze
reaction with hydrogen peroxide and the chromogen
tetramethylbenzidene
o Green-blue color
o Early indicator of liver disease; detected before jaundice
bilirubin
tablet for bilirubin test
ictotest
ictotest reagent tablet composition
◦ P-nitrobenzene-diazonium-p-toluenesulfonate
◦ SSA
◦ Sodium carbonate
◦ Boric acid
positive result for bilirubin in ictotest
: blue to purple color
Found in urine because as it is filtered by the glomerulus en
route to the liver
Urobilinogen
Classic test for differentiating urobilinogen,
porphobilinogen and Ehrlich-reactive compounds
Watson-Schwartz test
read niyo nlng mga results about Watson-Schwartz test
Interpretation Tube #1: ◦ Upper layer = urine If colorless: porphobilinogen or Ehrlich-reactive compounds ◦ Bottom layer = chloroform If red: urobilinogen3A – MT | 2013-2014 Page 14 ◦ If both layers are red, reextract urine layer from tube #1, place 2 mL chloroform and 4 mL sodium acetate into a new tube and repeat! - If upper layer (urine) is colorless and the chloroform layer is red = excess urobilinogen - If both layers are red = porphobilinogen & urobilinogen Tube #2 ◦ Upper layer = butanol If red: urobilinogen or Ehrlich-reactive compounds ◦ Bottom layer = urine If colorless: porphobilinogen
Rapid screening or monitoring of urinary
porphobilinogen
Hoesch screening test
Sources of error in Hoesch screening test
◦ Methyldopa
◦ Indicant
◦ Highly-pigmented urines
Rapid screening test for UT
nitrite
Reagent strip reactions (nitrite)
- Greiss reaction
- Pink colored azodye
true or false. nitrite reagent strip measures degree of bateuria
false
Sensitivity reagent strip of nitrite is standardized to correspond with a
quantitative bacterial criterion of ________ organisms/mL
100,000
(LE) causes of Inflammation of the urinary tract
Trichomonas
Chlamydia
Yeast
Inflammation of renal tissues
true or false. LE catalyze hydrolysis of acid ester on reagent pad
true
Based on the change in pKa of a polyelectrolyte in an
alkaline medium
Specific Gravity
rgt strip rxn for sp gr
o Release of H+
directly proportional to number of ions
o pH is thus lowered
o blue to green to yellow
source of false positive in specific gravity rgt strip
High concentrations of protein
source of false negative in specific gravity rgt strip
Highly alkaline urine
other term for macroscopic screening, being used to decide whether microscopic exam is needed
chemical sieving
positive for nitrite may signify what in microscopic?
bacteria/WBCs
positive for protein may signify what in microscopic?
casts
positive for glucose may signify what in microscopic?
yeast
used to count number of RBCs, WBCs, casts, and epithelial cells present in a 12-hour urine sample
Addis count
may cause precipitation of amorphous urates and phosphates and other nonpathologic crystals
refrigeration
solution to crystals caused by refrigeration
warming to 37 degrees
standard volume for urine sedimentation
10-15 mL
RBCs must be identified at
HPO
RBCs in hypersthenuric urine appear
crenated
large empty cells are called ________; lysed RBCs in hyposthenuric urine which released its hemoglobin content
ghost cells
usually associated with glomerular bleeding
dysmorphic RBCs
indicates damage to the glomerular membrane or vascular injury within the genitourinary tract
presence of RBCs
urine in macroscopic hematuria appears
cloudy with red to brown color
predominnt WBC in urine
neutrophil
neutrophils may be called _______ due to the sparkling appearnce caused by brownian movement
glitter cells
the presence of eosinophils in the urine is primarily associated with
drug induced interstitial nephritis
preffered stain for eosinophil in urine
Hansel stain
may resemble RBCs because of their size
lymphocytes
___ are usually larger than WBCs and more polyhedral in shape, woth an eccentrically located nucleus
RTE
increase in urine WBCs
pyuria
indicates presence of inflammation or infection in the genitourinary tract
pyuria
represents normal sloughing off of cells
epithelial cells
largest found in a ruine sediment
squamous epithelial cells
contains irregular, abundant cytoplasm, prominent nucleus about the size of a RBC
squamous epith cell
indicative of bacterial infection by Gardnerella vaginalis
clue cells
difference of a transitional epith cell from RTE cells
transitional has centrally located nucleus
rectangular shape and reffered to as columnar or convoluted cells
PCT RTE
smaller than those from PCT and are round and oval
DCT RTE
cuboidal and never round
collecting duct RTE
the presence of ________ RTE cells per hpf indicates ______
2
tubular injury
RTE cells absorb lipids present in the glomerular filtrate, and then appear highly refractile
oval fat bodies
stain for oval fat bodies
sudan III
oil red o
most frequently associated with damage to the glomerulus caused by nephrotic syndrome
lipiduria
RTE cells containing non-lipid filled vacuoles
bubble cells
acidic crystals include
cystine cholesterol leucine tyrosine bilirubin sulfonamide ampicillin uric acid amorphous urates calcium oxalate
color of cystine crystal
colorless
color of bilirubin crystal
yellow
color of leucine crystal
yellow
most frequent parasite in urine
trichomonas vaginalis
a major constituent of mucus in urine
Tamm-Horsfall protein
formed within the lumens of the DCT and collecting tubes
casts
appearancce of cast
tubular with rounded ends
presence of casts in urien is called
cylindruria
hyaline cast is colored ___
colorless
specific finding indicating bleeding in the nephron
RBC casts
primary marker for distinguishing upper UTI from lower UTI
WBC casts
indicates advanced tubular destructon
epithelial cell casts
representative of extreme urine stasis indicating chronic renal failuer
waxy casts
also called renal failure casts, similar to waxy casr
broad cast
formed by the precipitation of urine solution
crystals
most common crystal found in the urine
urates
alkaline crystals include
amorphous phosphates calcium phosphate triple phosphate ammonium biurate calcium carbonate
color of amorphous urates
brick dust or yellow brown
appears like throny apple
ammonium biurate
dumbbell shaped
calcium carbonate
appears dumbbell shaped, oval and envelope
calcium oxalate
appears like coffin lids
triple phosphate
with notched corners
cholesterol crystals
appears in fine needle clumps
tyrosine
hexagonal shaped crystal
cystine crystal
varies upon refrigeration
ampicillin crystals
appears in rosette form
sulfa crystal
artifacts may include
pollen grain
diaper fiber
fecal material
vegetable fiber