CHEMICAL EXAM prt.1.2 Flashcards
pH
•Kidneys secrete hydrogen in the form of (3) and reabsorb____
ammonium ions
hydrogen phosphate
weak organic acids
bicarbonate
NORMAL pH VALUES
• Random urine pH:________
• First morning urine pH (healthy individual):______
4.5 to 8.0
5.0 to 6.0
pH of______ or higher: NOT NORMAL!
• This suggests contamination, bacterial overgrowth, or improper sample storage.
• pH values above 8.0 or below 4.5 are physiologically impossible and indicate potential _____
9.0
adulteration or contamination.
Normal values for pH
NO NORMAL VALUES: Must be considered in conjunction with other patient information
FACTORS AFFECTING URINE pH
Diet and Medications
• High-protein diets →_____
• Vegetarian diets (except cranberry juice) →______
• Cranberry juice →______(prevents bacterial growth)
Acidic urine
Alkaline urine
Acidic urine
Clinical Uses of pH Management
1. Diagnosis of systemic acid-base disorders
• Acidic urine →________
• Alkaline urine →________
Metabolic or respiratory acidosis (unless caused by renal disease)
Metabolic or respiratory alkalosis (unless caused by renal disease)
Clinical Uses of pH Management
- Management of urinary conditions
• Kidney stone prevention:
• ______stones form in___(pH) urine.
• Maintaining____(pH) urine discourages stone formation.
Calcium oxalate
acidic
alkaline
CLINICAL SIGNIFICANCE
- Management of urinary conditions
Urinary tract infections (UTIs):
•_____(pH) urine inhibits the growth of urea-splitting bacteria (e.g., Proteus, Klebsiella, Pseudomonas).
• Maintenance of_____(pH) urine helps treat UTIs.
Acidic
pH
Physiologically impossible! Suggests urine adulteration (e.g., acidification with chemicals).
<4.5
pH
Physiologically impossible! Suggests:
- Iatrogenic alkaline contamination (e.g., from medical interventions).
- Improperly stored urine specimen (bacteria decompose urea into ammonia, increasing pH).
- Contamination with an alkaline chemical.
> 8.0
> 8.0
Physiologically impossible! Suggests:
- Iatrogenic alkaline contamination.
- Improperly stored urine specimen
- Contamination with an alkaline chemical.
pH
NOTE:
1. Maintaining urine at an alkaline pH discourages formation of the____
2. Maintenance of an acidic urine can be of value_____
calculi
(UTI) treatment
@Most indicative of renal disease
PROTEIN
Normal urine contains very little _____
PROTEIN
Major serum protein found in urine:
ALBUMIN
Others:
microglobulins
uromodulin (Tamm-Horsfall protein)
proteins from prostatic, seminal, and vaginal secretions
Normal urine protein consists of:
•________ that are small enough to be filtered by the glomerulus but are mostly reabsorbed in the proximal tubule.
• Proteins secreted by the____
Low molecular weight (LMW) serum proteins
genitourinary tract (non-renal sources)
does not always signify renal disease (more tests required to determine if the it present is pathologic or physiologic)
proteinuria
*Causes of proteinuria can be grouped into three major categories:
Pre-renal
Renal
Post-renal
PRE-RENAL PROTEINURIA
•Caused by increased levels of LMW plasma proteins that exceed the normal reabsorptive capacity of the tubules
Hemoglobin
Myoglobin
Acute phase reactants
Caused by conditions affecting the plasma prior to reaching the kidney
•NOT INDICATIVE OF ACTUAL RENAL DISEASE
PRE-RENAL PROTEINURIA
Now:
cases of multiple myeloma are easily detected by chemical methods and diagnosed by____ (classic ‘_____ spike’ in the gamma globulin region) and immunoelectrophoresis
serum electrophoresis
M spike
• Monoclonal immunoglobulin light chains excreted by patients with multiple myeloma
BENCE-JONES PROTEIN
Historical screening test for BENCE-JONES PROTEIN
If protein coagulates (becomes turbid) at ________ and dissolves (clears) at_______ (other proteins remain coagulated
40°C and 60°C
100°C
occurs when the kidneys themselves are damaged, leading to the loss of proteins in the urine
Renal proteinuria
May be the result of either glomerular or tubular damage
Renal proteinuria
RENAL PROTEINURIA
“May be the result of either glomerular or tubular damage
(4)
• Glomerular proteinuria
• Microalbuminuria
• Orthostatic (postural) proteinuria
•Tubular proteinuria
presence of abnormal substances in the glomerular membrane may damage the glomerular membrane
GLOMERULAR PROTEINURIA
CAUSES OF GLOMERULAR PROTEINURIA (3)
Amyloid material in amyloidosis (buildup can cause organ failure)
Toxic substances
Immune complexes (main cause)
increased pressure from the blood entering the glomerulus
May be reversible or transient (strenuous exercise and dehydration, hypertension, pregnancy)
GLOMERULAR PROTEINURIA
urinary albumin excretion of 30-300 mg/day, or 20-200 g/min
Amount of urinary albumin greater than the normal value, but also lower than what is detected by a conventional dipstick
MICROALBUMINURIA
MICROALBUMINURIA
urinary albumin excretion of______ or ______
Amount of urinary albumin greater than the normal value, but also lower than what is detected by a conventional dipstick
30-300 mg/day
20-200 g/min
Common in patients with early-stage diabetic nephropathy leading to reduced glomerular filtration
MICROALBUMINURIA
• early-stage diabetic nephropathy
• Poor glucose control inhibits N-deacetylase needed to form the heparan sulfate
•Decreased proximal tubular albumin reabsorption
MICROALBUMINURIA
MICROALBUMINURIA/ MICRAL TESTING
Micral-Test Reagent Strips
Contain_______
gold-labeled antihuman albumin antibody-enzyme conjugate
Micral-Test Reagent Strip
Principle of the Micral-Test
Contain _____-labeled antihuman albumin antibody-enzyme conjugate
Strips are dipped in urine for ____ seconds and compared with the color chart after____
_____in the urine binds to the antibody. The bound and unbound conjugates move up the strip by wicking action.
Unbound conjugates are removed in a captive zone by combining with albumin embedded in the strip.
The urine albumin-bound conjugates continue up the strip and reach an area containing enzyme substrate.
The conjugated enzyme reacts with the substrate, producing colors ranging from white to red.
The amount of color produced represents the amount of albumin present in the urine.
gold
5 seconds; 1 minute
Albumin
Occurs following long periods spent in a vertical position and disappears when a horizontal position is assumed
ORTHOSTATIC PROTEINURIA
ORTHOSTATIC PROTEINURIA
Due to increased pressure on the ______
Renal vein
ORTHOSTATIC PROTEINURIA
Collect urine after ______and another specimen after______
Orthostatic proteinuria:
if specimen 1 is______ for protein and specimen 2 is_____ for protein
waking up; after remaining in a vertical position for several hours
negative; positive
•Failure to reabsorb filtered albumin
TUBULAR PROTEINURIA
TUBULAR PROTEINURIA
Causes:
exposure to toxic substances and heavy metals
severe viral infections
Fanconi syndrome
A defect of proximal tubule leading to malabsorption of various electrolytes and substances that are usually absorbed by the proximal tubule
Fanconi syndrome
Bacterial and fungal infections and inflammations produce exudates containing protein
POST-RENAL PROTEINURIA
Presence of blood from injury or menstrual contamination
POST-RENAL PROTIENURIA
Prostatic fluid and large amounts of spermatozoa
POST-RENAL PROTEINURIA
A cold precipitation test that reacts equally with all forms of protein
SULFOSALICYLIC ACID TEST
SULFOSALICYLIC ACID TEST
Add_____ ml of _____ SSA reagent to_____
3 ml of 3% SSA
3 ml centrifuged urine
PROCEDURE FOR SSA TEST
- Centrifuge the_____ to remove any cellular debris or contaminants.
- Take_____ of the supernatant (clear urine portion).
- Add_____.
- Observe for turbidity (cloudiness) and grade the reaction.
urine sample
3 mL
3 mL of a 3% Sulfosalicylic Acid (SSA) reagent
