urinalysis and body fluids review

which statement regarding renal function is true?

glomeruli are far more permeable to water and salt than other capillaries

which statement regarding normal salt and water handling by the nephron is correct?

the ascending limb of the tubule is highly permeable to salt but not water

which statement concerning renal tubular function is true?

in salt deprivation, the kidneys will conserve sodium at the expense of patassium

which of the following is innappropriate when collecting urine for routine bacteriologic culture?

the sample may be held at 2-8C for up to 48 hours prior to plating

which statement about sample collection for routine urinalysis is true?

samples may be stored at room temp for up to 2 hours

which urine color is correlated correctly with the pigment producing substance?

deep yellow urine and yellow foam with bilirubin

which of the following substances will cause urine to produce red fluorescence when examined with an ultraviolet lamp (360 nm)?

coproporphyrin

which of the following conditions is associated with normal urine color but produces red fluorescence when urine is examined with an UV (woods) lamp?

lead poisoning

which statement regarding porphyria is accurate?

serum, urine, and fecal tests may be needed for diagnosis

which is the most common form of porphyria?

porphyria cutanea tarda

which of the following methods is the least sensitive and specific for measuring PBG in urine?

watson-schwartz test

a brown or black pigment in urine can be caused by:

melanin

urine that is dark red or port wine in color may be caused by:

porphyria cutanea tarda

which of the following tests is affected least by standing or improperly stored urine?

protein

which type of urine sample is needed for a d-xylose absorption test on an adult patient?

5 hour timed urine kept under refrigeration

which of the following is inappropriate when collecting a 24 hour urine sample for catecholamines?

ten mL of 1N sodium hydroxide should be added to the container before collection

urine production of less than 400 a day is:

defined as oliguria

which of the following contributes to SG, but not to osmolality?

protein

urine with an SGconsistently between 1.0022 and 1.003 indicates:

diabetes

in which of the following conditions is the urine SG likely to be below 1.025?

chronic renal failure

which statement regarding methods for measuring SG is true?

to correct a urinometer, subtract .001 per each 3C below 15.5C

what is the principle of the colorimetric reagent strip determination of SG in urine?

ionic strength alters the pKa of a polyelectrolyte

which statement regarding urine pH is true?

contamination should be suspected if urine pH is less than 4.5

in renal tubular acidosis, the pH of urine is:

consistently alkaline

the normal daily urine output for an adult is approximately:

.6-1.6 L

the SG of the filtrate in bowmans space is approximately:

1.008-1.010

a patient with partially compensated respiratory alkalosis would have a urine pH of:

7.5-8.5

which of the following is most likely to cause a false positive dry reagent strip test for urinary protein?

highly buffered alkaline urine

when testing for urinary protein with sulfosalicylic acid (SSA), which condition may produce a false positive result?

the presence of xray contrast media

a discrepancy between the urine SG determined by measuring refractive index and urine osmolality would be most likely to occur:

after an intravenous pyelogram (IVP)

which of the following is likely to result in a false negative dry reagent strip test for proteinuria?

bence jones protein

daily loss of protein in urine normally does not exceed:

150

which of the following is least likely to cause a false positive result with turbidimetric protein tests?

ascorbic acid

which statement best describes the clinical utility of test for microalbuminuria?

testing may detect early renal involvement in diabetes

dry reagent strip tests for microalbuminuria that compare albumin to creatinine determine the creatinine concentration based upon which principle?

formation of Cu-creatinine complex

which of the following conditions is least likely to be detected by dry reagent strip tests for proteinuria?

renal tubular proteinuria

the normal renal threshold for glucose is:

165-180

in which of the following conditions is glycosuria most likely?

pregnancy

in addition to ascorbate, the glucose oxidase reaction may be inhibited by which substance?

acetoacetic acid (AAA)

a positive glucose oxidase test and a negative test for reducing sugars indicates:

true glycosuria

a negative glucose oxidase test and a positive test for reducing sugars in urine indicates?

the presence of a nonglucose reducing sugar such as galactose

in what condition may urinary ketone tests underestimate ketosis?

acidosis

AAA is detected in urine by reaction with:

sodium nitroprusside

nondiabetic ketonuria can occur in all of the following except:

renal failure

which of the following statements regarding the classical nitroprusside reaction for ketones is true?

it may be falsely positive in phenylketonuria

hemoglobin in urine can be differentiated from myoglobin using:

80%ammonium sulfate to precipitate hemoglobin

which of the following conditions is associated with a negative blood test and an increase in urine urobilinogen?

extravascular hemolytic anemia

which statement about the dry reagent strip blood test is true?

abnormal color may be absent from the urine when the reaction is positive

a moderate positive blood test and trace protein test are seen on the dry reagent strip, and 11-20 red blood cells per high power field are seen in the microscopic exam. these results are most likely caused by which of the following?

recent urinary tract catheterization

which of the following results are discrepant?

negative blood but 6-10 RBC/hpf

which of the following statements regarding the dry reagent strip test for bilirubin is true?

the test detects only conjugated bilirubin

which of the following reagents is used to detect urobilinogen in urine?

p-dimethylaminobenzaldehyde

which of the following statements regarding urinary urobilinogen is true?

dry reagent strip tests do not detect decreased levels

which of the following statements regarding the test for nitrite in urine is true?

the test is dependent upon an adequate dietary nitrate content

which statement about the dry reagent strip test for leukocytes is true?

the reaction is based upon the hydrolysis of substrate by WBC esterases

which of the following statements about creatinine clearance is correct?

creatinine clearance is dependent upon lean body mass

a male patients eGFR is 75. this indicates:

reduced glomerular filtration without uremia

which of the following tests is a specific measure of glomerular filtration?

cystatin C

which statement regarding urea is true?

urea is 100% filtered by the glomeruli

given the data, calculate the creatinine clearance:

serum creatinine: 1.2

urine creatinine: 100

urine volume: 1.4

body surface area: 1.8

78 ml/min

which of the following dyes are used in sternheimer-malbin stain?

crystal violet and safranin

which of the following statements regarding WBC in urinary sediment is true?

WBC casts indicate the pyuria is of renal, rather than lower urinary, origin

which description of sediment with sternheimer-malbin stain is correct?

transitional epithelium: cytoplasm pale blue, nucleus dark blue

a 5 mL urine specimen is submitted for routine urinalysis and analyzed immediately. the SG of the sample is 1.012 and the pH is 6.5. the dry reagent strip test for blood is a large positive (3+) and the micro exam shows 11-20. the leukocyte esterase reaction is a small pos (1+), and the micro exam shows 0-5 WBC. what is the most likely cause of the results?

insufficient volume is causing micro results to be underestimated

which of the following statements regarding epi cells in the urinary system is correct?

transitional cells originate from the upper urethra, ureters, bladder, or renal pelvis

which of the statements regarding exam of unstained sediment is true?

large numbers of transitional cells are often seen after catheterization

which of the following statements regarding cells found in urinary sediment is true?

renal tubular cells are often polyhedral and have an eccentric round nucleus

which of the following statements regarding RBC in the urinary sediment is true?

RBC of glomerular origin often appear dysmorphic

renal tubular epi cells are shed into the urine in largest numbers in which condition?

CMV infection of the kidney

the ova of which parasite may be found in the urinary sediment?

schistosoma hematobium

oval fat bodies are often seen in:

nephrotic syndrome

all of the following statements regarding urinary casts are true except:

casts can be seen in significant numbers even when protein tests are negative

which condition promotes the formation of casts in the urine?

reduced filtrate formation

the mucoprotein that forms the matrix of a hyaline cast is called:

tamm-horsfall protein

pseudocasts are often caused by:

amorphous urates

which of the following statements regarding urinary casts is correct?

broad casts are associated with severe renal tubular obstruction

a sediment with moderate hematuria and RBC casts most likely results from:

acute glomerulonephritis

urine sediment characterized by pyuria with bacterial and WBC casts indicates:

pyelonephritis

which type of casts signals the presence of chronic renal failure?

waxy casts

urinalysis of a sample from a patient suspected of having a transfusion reaction reveals small yellow-brown crystals in the micro examination. dry reagent strip tests are normal with the exception of a pos blood reaction (moderate) and trace pos protein. the pH of the urine is 6.5. what test should be performed to pos identify the crystals?

prussian blue stain

when examining urinary sediment, which of the following is considered an abnormal finding?

0-1 renal cell casts per LPF

a urine sample with a pH of 6 produces an abundance of pink sediment after centrifugation that appears as densely packed yellow to reddish brown granules under the microscope. the crystals are so dense that no other formed elements can be evaluated. what is the best course of action?

suspend the sediment in prewarmed saline, then repeat centrifugation

how can hexagonal uric acid crystals be distinguished from cystine crystals?

cystine gives a pos nitroprusside test after reduction with sodium cyanide

the presence of tyrosine and leucine crystals together in a urine sediment usually indicates:

chronic liver disease

which of the following crystals is considered nonpathological?

ammonium biurate

at which pH are ammonium biurate crystals usually found in urine?

alkaline urine only

which of the following crystals is seen commonly in alkaline and neutral urine?

magnesium ammonium phosphate

which crystal appears in urine as a long, thin, hexagonal plate, and is linked to ingestion of large amounts of benzoic acid?

hippuric acid

small yellow needles are seen in the sediment of a urine sample with a pH of 6. which of the following crystals can be ruled out?

cholesterol crystals

oval fat bodies are derived from:

renal tubular epithelium

oval fat bodies are often associated with:

lipoid nephrosis

urine of constant SG ranging from 1.008 to 1.010 most likely indicates:

renal tubular failure

which of the following characterizes prerenal failure, and helps to differentiate it from acute renal failure caused by renal disease?

BUN:creatinine ratio of 20:1 or higher

which of the following conditions characterizes chronic glomerulonephritis and helps to differentiate it from acute glomerulonephritis?

polyuria

which of the following conditions is seen in acute renal failure and helps to differentiate it from prerenal failure?

abnormal urinary sediment

which of the following conditions characterizes acute renal failure and helps to differentiate it from chronic renal failure?

hyperkalemia

the serum concentration of which analyte is likely to be decreased in untreated cases of acute renal failure?

calcium

which of the following conditions is associated with the greatest proteinuria?

nephrotic syndrome

which of the following conditions is often a cause of glomerulonephritis?

systemic lupus erythematosus

acute pyelonephritis is commonly caused by:

bacterial infection of medullary interstitium