Clinical Study Questions

Question 1

What are the three ketone bodies?

Answer 1

acetone, acetoacetic acid, beta-hydroxybutyric acid

Question 2

What does the presence of ketone bodies in urine indicate?

Answer 2

carbohydrate metabolism is deficient, body is using fat as the major energy source

Question 3

Which ketone body exists in the highest concentration?

Answer 3

beta-hydroxybutyric acid

Question 4

Which ketone body are most urinalysis strip tests most sensitive to?

Answer 4

acetoacetic acid

Question 5

What is the principle of the reaction for ketone bodies with Multistix testing?

Answer 5

sodium nitroprusside, in the presence of acetoacetic acid, produces a color change from buff pink (=) to purple (+) as ketone concentration increases

Question 6

Are acetone and/or beta-hydroxybutyric acid detected with Multistix testing?

Answer 6

no

Question 7

What is the pH a measure of in terms of kidney function?

Answer 7

measures the kidney’s ability to maintain normal hydrogen ion concentration in plasma and extracellular fluid

Question 8

What is the principle of the reaction for pH with Multistix testing?

Answer 8

utilizes the methyl red/bromthymol blue indicator system, which provides pH readings from 5.0-8.5; test pad color changes from orange to green to blue in this pH range

Question 9

What is hematuria and when would it be seen?

Answer 9

abnormal number of intact red cells; kidney or urinary tract disease

Question 10

What is hemoglobinuria and when would it be seen?

Answer 10

free hemoglobin in the urine; any condition resulting in intravascular hemolysis

Question 11

What is myoglobinuria and when would it be seen?

Answer 11

myoglobin (heme-containing protein) in the urine; rhabdomyolysis (muscle destruction)

Question 12

What is the principle of the reaction for occult blood in Multistix testing?

Answer 12

based on the peroxidase-like activity of hemoglobin, which catalyzes the reaction of diisopropylbenzene dihydroperoxide and uses 3,3’,5,5’-tetramethylbenzidine; blood is detected as intact red cells or as free hemoglobin; liberation of oxygen from peroxide through heme causes a benzidine compound to oxidize to a colored product ranging from orange to green to dark blue

Question 13

How is protein measured with Multistix testing?

Answer 13

protein error of indicators; utilizes tetrabromophenol blue reagent buffered at a pH of 3; the point of color change is different in the presence or absence of certain proteins, ranging from yellow (=) through yellow-green, green, and blue-green

Question 14

What must one keep in mind when testing for protein with Multistix in regards to sensitivity?

Answer 14

test pad is more sensitive to albumin than globulins (gammaglobulins, Bence-Jones proteins, hemoglobin, mucoprotein), and a negative result does not necessarily rule out the presence of the other proteins

Question 15

What reaction can be caused by buffered alkaline urine in regards to protein Multistix testing?

Answer 15

may produce false positives

Question 16

What is the difference between specific gravity and osmolality?

Answer 16

specific gravity measures the ratio of the density of a substance to the density of a reference substance; osmolality measures the concentration of a substance contained within a reference substance

Question 17

Between specific gravity and osmolality, which is more accurate and why?

Answer 17

osmolality; it is not affected by large or heavy particles, whereas specific gravity is

Question 18

Which protein in urine coagulates on heating to 45-60*C and re-dissolves on further heating to the boiling point?

Answer 18

Bence-Jones protein

Question 19

What two structures may be confused with white cells in a urine specimen, and how would they be differentiated?

Answer 19

red cells (smaller, bi-concave, can be lysed with 2% acetic acid); collecting duct cells (large and dense nuclei, polygonal shape)

Question 20

What two structures may be confused with red cells in a urine specimen, and how would they be differentiated?

Answer 20

bubbles (variation in size, highly refractile); yeast (variation in size, tends to be more spherical/ovoid rather than bi-concave, exhibits budding, will not lyse in acetic acid)

Question 21

What is the reaction of the Multistix reaction for glucose?

Answer 21

double sequential enzyme reaction: glucose + O2 –glucose oxidase–> gluconic acid + H2O2 –> H2O2 + chromagen –peroxidase–> oxidized chromagen + H2O

Question 22

Under what conditions would you see a negative dipstick and a positive Clinitest when testing for glucose?

Answer 22

non-glucose reducing substance (typically galactose)

Question 23

What are oval fat bodies?

Answer 23

renal tubular epithelial cells containing fat

Question 24

What do oval fat bodies exhibit under polarized microscopy?

Answer 24

Maltese cross formation

Question 25

Where are casts formed?

Answer 25

distal and collecting tubules of the kidneys

Question 26

What conditions bring about cast formation?

Answer 26

can appear normally (hyaline casts), glomerulonephritis, acute interstitial nephritis, pyelonephritis, chronic or acute renal disease, athletic pseudonephritis

Question 27

What do casts signify clinically?

Answer 27

number of casts reflects the extent of tubular involvement and severity of disease; type and number together can indicate a specific disease state

Question 28

Can the width of a cast be an indication of the severity of renal disease? Explain.

Answer 28

yes; broad casts (called renal failure casts) indicate cast formation in dilated convoluted tubules or in the collecting ducts; because one collecting duct may serve several nephrons, cast formation within them indicates significant urinary stasis due to either obstruction or disease

Question 29

What are hyaline casts composed of and when can they appear?

Answer 29

Tamm-Horsefall protein matrices; following strenuous exercise and stress

Question 30

What constitutes a cellular cast?

Answer 30

protein matrix filled with degenerating cells

Question 31

When can bacterial casts appear?

Answer 31

pyelonephritis and kidney infections

Question 32

When can red cell casts appear?

Answer 32

glomerulonephritis and strenuous exercise

Question 33

What are fatty casts and what are they associated with?

Answer 33

protein matrix containing fat globules; nephrotic syndrome

Question 34

What are waxy casts and how do they appear?

Answer 34

final breakdown product of a cellular cast; sharp, refractile outline with irregular, broken-off ends

Question 35

What kind of casts can appear in renal tubular damage?

Answer 35

renal tubular epithelial cell casts

Question 36

What is nephrotic syndrome?

Answer 36

caused by damage to the kidneys resulting in the release of too much protein into the urine

Question 37

What results would be expected in a urinalysis on a patient with nephrotic syndrome?

Answer 37

large amounts of protein, fatty casts

Question 38

What is the synonym for nephrotic syndrome?

Answer 38

nephrosis

Question 39

What is the source of bleeding if urine contains red cells but minimal protein?

Answer 39

kidneys (glomerulonephritis)

Question 40

What does the creatinine clearance test measure?

Answer 40

glomerular filtration rate

Question 41

In what two types of jaundice will bilirubin be found in the urine?

Answer 41

hepatic, obstructive

Question 42

What is the principle of the reaction for bilirubin with Multistix testing?

Answer 42

bilirubin reacts with diazonium salt (2,4-dichloroaniline) to form a tan color

Question 43

What three urine constituents are detected by the SSA protein procedure but not by the protein portion of Multistix?

Answer 43

albumin, Bence-Jones protein, and immunoglobulin light chains

Question 44

In what two types of jaundice will increased urobilinogen be found in the urine?

Answer 44

hepatic, hemolytic

Question 45

What is the principle of the reaction for urobilinogen with Multistix testing?

Answer 45

urobilinogen will react with p-dimethylaminobenzaldehyde in an acid medium to produce a pink-red color

Question 46

In what two conditions will urobilinogen be decreased in the urine, and why?

Answer 46

obstructive jaundice - bile containing direct bilirubin cannot enter the intestines, where it becomes urobilinogen; chronic liver disease - indirect bilirubin cannot be further processed by the liver, meaning there is little direct bilirubin available for conversion to urobilinogen

Question 47

What is a glitter cell?

Answer 47

swollen white cells whose cytoplasmic granules exhibit Brownian movement; associated with pyelonephritis and low specific gravity

Question 48

What are kidney stones?

Answer 48

solid material formed in the kidneys from minerals present in the urine; also called renal calculi or nephroliths

Question 49

What is the most common type of kidney stone?

Answer 49

calcium compounds, such as calcium oxalate or calcium phosphate

Question 50

What is the spot plate method of calculi analysis?

Answer 50

a drop of chemical reagent is added to the unidentified calculi; if the compound being tested for is present, observable changes will take place

Question 51

What effect does radiographic dye have on specific gravity?

Answer 51

increases it