Chemical Examination Flashcards
pH of a first-morning urine sample from a healthy individual
5.0 - 6.0 pH
Ph of a random urine sample from a healthy individual:
4.5 - 8.0 pH
Normal values for urine:
None. Values must be considered in conjunction with other patient info
Kidneys secrete hydrogen in what form?
Ammonium ions
Hydrogen phosphate
Weak organic acids
What does the kidney reabsorb to increase urine pH
Bicarbonate
High protein diet causes __________ urine
Acidic
Explain the clinical significance of pH in urine
- It aids in determining the existence of systemic acid-base disorders.
- Management of urinary conditions that require a specific pH to be maintained
What is the most common cause of kidney stones, and the pH where can be found?
Calcium oxalate, acidic urine
To avoid UTI, a person must keep a/an _____ urine pH
Acidic
What is the most indicative of a renal disease? Why?
Protein. There must be very low levels of protein in the urine. Those protein found in the urine are normally produced by the genitourinary tract.
Reagent strips are sensitive to what kind of protein?
Albumin
What is the major serum protein that is found in the urine?
Albumin
Aside from the major serum protein found in the urine, what else can be found?
Uromodulin
Microglobulin
Protein from prostatic, seminal, and vaginal secretions
Uromodulin is also known as:
Tamm-horsfall protein
What are the categories that cause proteinuria?
Pre-renal
Renal
Post-renal
Is pre-renal proteinuria an indicative of actual renal disease? Why or why not?
It is not an indicative of an actual renal disease because the problem is that there’s just too many protein in the body’s circulation
Pre-renal proteinuria is commonly caused by increased levels of
LMW plasma
Examples of LMW plasma proteins
Hemoglobin
Myoglobin
Acute phase reactants
Patients with multiple myeloma excrete monoclonal immunoglobulin light chains that are called ____
Bence-jones proteins
What is the modern test for bence-jones proteins?
Serum electrophoresis
What are the 4 renal proteinuria?
Glomerular proteinuria
Microalbuminuria
Orthostatic proteinuria
Tubular proteinuria
What commonly causes the damage in gromular proteinuria?
Immune complexes
What are the abnormal substances that may cause glomerular proteinuria?
Amyloid material
Toxic substances
Immune complexes
Modified true or false:
Low blood pressure entering the glomerulus can cause damage that results to glomerular proteinuria
False. Increased blood pressure
Normal values of urinary albumin excretion:
30-300 mg/day
Or
20-200 ug/min
Low presence of albumin, but megative reagent strip for urine albumin signifies what?
Early kidney damage due to DM
Poor glucose control inhibits ________ which helps in forming ________.
N-deacetylase
Heparan sulfate
Importance of heparan sulfate
Maintains the shield of negativity to the glomerular basement membrane
Micral test is dipped for how long? When do we compare the results?
5 seconds
1 minute
Principle of micral test
Alb + ab -> bound conjugate -> albumin (skip) -> enzymatic substrate -> color change
Or
Alb +ab + enzyme substrate = color change
In what zone will the unbound conjugate get trapped into?
Zone 2
Other name for orthostatic proteinuria
Postural proteinuria
Orthostatic proteinuria is due to what?
Incressed pressure on the renal vein when standing up for long periods
How does tubular proteinuria occur?
Failure to reabsorb filtered albumin
What are the causes of tubular proteinuria?
Exposure to toxic substances
Heavy metals
Severe viral infections
Fanconi syndrome
Fanconi syndrome is a defect in which part of the kidney?
Proximal tubule
Causes of post-renal proteinuria
- Exudates containing protein from infections and inflammations
- Blood from injury or menstrual contamination
- Prostatic fluid and large amounts of sperm
Modified true or false: Protein from the lower urinary tract causes renal proteinuria
False. Post-renal proteinuria
Sulfosalicylic acid test is a _______ test that reacts equally with all forms of protein
Cold precipitation
The most frequently performed chemical analysis in urine
Glucose
What is the ideal specimen for glucose testing?
Fasting specimen
What is the specimen for diabetes monitoring?
2-hour postprandial specimen
Why is it important not to eat anything with sugar when testing for glucose?
Because there is a glucose spike after meal
Examples of non-diabetic origin hyperglycemia
Cushing syndrome
Pancreatitis
Acromegaly
Hyperthyroidism
Severe stress (hormones)
What is the test for glucose and its method?
Clinitest
Copper reduction method
What is the inital color in copper sulfate method?
Negative blue
True or false: reagent strip is more accurate than clinitest
True
What are the 3 forms of ketones in the blood
Acetone
Acetoacetic acid
B-hydroxybutyrate
What is the renal threshold for ketones in the urine?
70 mg/dL
Explain why ketones appear in the body
When our primary source of energy, carbohydrates, are compronised, our body metabolises fats (gluconeogenesis) to supply energy throughout the body
Explain the formation of ketones
The metabolosm of triglycerides will form acetyl CoA, where it then proceeds to Krebs cycle to produce, ATP, CO2, and H2O. However, when there’s too much acetyl CoA, it leades to the formation of ketone bodies.
Ferric chloride test is also known as
Gehrardt’s test
