the urine which is found in the calyx of the kidney, empties into which structure of the kidney?
substances that may interfere with measurements of urine and serum osmolarity include all of the following except:
which statement regarding the normal salt and water handling by the nephron is correct?
The ascending loop of henle
which of the following is not involved with the bicarbonate ions
regulates calcium tubular secretion
water reabsorption (without stimulation from hormones) occurs in what parts of the nephron?
both proximal convoluted tubules and distal convoluted tubules
calcualte the creatine clearance rate using the following date: serum creatine = 2.4mg/dl
urine creatinine = 105mg/dl urine volume = 1.4L/day surface area = 1.80m^2
which of the following is the end product of the protein metabolism and is synthesized in the liver from the ammonia and carbon dioxide?
blood flow through the nephron in the following order ?
Afferent arteriole, glomerulus efferent arteriole, peritubular capillaries, vasa recta, peritubular capillaries
the small renal artery branch in the nephron, through the blood flows away from the glomerulas is known as?
to provide an accurate measure of the renal blood flow, a test substance should be completely:
cleared on each contact with functional renal tissue
which of the following statement are correct about creatinine clearance is correct?
creatinine clearance is mainly determined by renal tubular function
of the ultrafiltrate passing through the glomerulus what percentage is ultimately excreted as urine ?
diabetics frequently drink excessive amounts of fluids to quench their thirst. this symptom is called:
an unidentified fluid is received in the laboratory with a request to determine if the fluid is urine or another bod fluid. Using routine laboratory tests, what test would determine that the fluid is most probably urine?
urea and creatinine
which of the following is the closest to the reference range for total urine output in a single day(ml/day)
500 to 1800
what is the differance btw osmolality and osmolarity?
osmolality is the concentration of an osmotic solution especially when measured in osmols or milliosmoles per 1000 grams of solvent. osmolarity is the concentration of an osmotic solution especially when measured in osmols or milliosmole per liters of solvent.
what is the formula for the manual calculations of osmolality?
1.86(NA)+(glu/19) + (BUN/2.8) = osmolality
what is urea
the end product of protein matabolism. it is synthesized in the liver from ammonia and carbon dioxide.
why should tubes containing fluoride or citrate not be used when collecting blood for urea if analysis will be by the urease method?
flouride and citrate inhibit urease.
what is creatinine?
the anhydride of creatine . Creatinine is formed from creatine by splitting out water.
what reaction is used to measure creatinine?
the jeffe reaction using alkaline picrate. It is non-specific, but still clinically useful, method.
what is the significance of BUN: creatinine ratio?
It helps determine the cause of an increased BUN. The normal ratio is approximately 10:1 to 20:1.
higher ratios are due to non-renal causes, such as high protein diet, increased rate of protein catabolism, or decreased renal blood flow.
with these conditions the BUN increases more than the creatinine.
with renal disease, the BUN and creatinine increases proportionally.
Calculate the BUN: creatinine ratio for a patient whose BUN is 45mg/dl and whose creatinine is 2.1 mg/dl
45/2.1 = 21.4
what is the estimated glomerular filtration rate (eGFR)?
A calculation value based on serum creatinine and the patient's age sex, and race. the national kidney disease education program encourages reporting eGFR along with serum creatinine because it is a more sensitive indicator of the kidney disease. At this time, the practice is not widely adopted.
what is uric acid?
the end product of purine metabolism. the purines are adenosine and guanine, components of nucleic acids.
uric acids is increased in gout, renal disease, and condition where there is high cellular turnover, such as leukemia.
what reagents is commonly used to measure uric acid
Uricase. the preservative sodium fluoride must not be used to collect the blood sample because it destroys uricase.
what may results from high levels of uric acid?
urate crystals may precipitation in joints and tissue.
why must the PH of urine for uric acid determination be adjusted 7.5-8?
to prevent precipitation of uric acid. uric acid precipitates at acid ph.
which of the following statements regarding urea is true?
urea is the major nitrogen-containing metabolite from the degradation of protein.
An increased serum level of which of the following analytes is most commonly associated with decrease GFR.
which of the following test would best support the diagnosis of chronic renal failure?
increased BUN, increased creatinine
creatinine is a good substance to use for a clearance test because?
It's blood values are stable day to day
In the urea method, the enzymatic reaction of urease is inhibited when the blood for analysis is drawn in a tube containing which of the following anticoagulants?
A patient has the following values?
serum creatinine =2.0 mg/dl
urine creatinine =123mg/dl
24hour urine =1460mls
patient height=5ft 8in
calculate the creatinine clearance?
blood flows through the nephron in the following order?
Afferant arteriole, pertitubular capillaries, vase recta, efferent arteriole.
glucose will appear in the urine when the:
blood levels of glucose is 200 mg/dl
TM for glucose is reached
renal threshold for glucose is exceeded
bicarbonate ions filtered by the glomerulus are returned to the blood?
the proximal convoluted tubule
combined with hydrogen ions
by tubular secretion
place the appropriate letter in front of the following clearance substances: A.exogenous
given the following information, calculate the creatinine clearance
24 hour urine volume : 1000 ml; serum creatinine : 2.0 mg/dl; urine creatine 200 mg/dl
given the data serum creatinine: 1:1 mg/dl; age 50 years, and weight 72 kg the estimated creatinine clearance using the cockcroft-gault formula is :
variables that may be included in estimated creatinine clearance calculations include all of the following except:
An advantage to using cystain C to monitor GFR is :
It does not require urine collection
it is not secreted by the tubules
it can be measured by immunoassay
substances that may interfere with measurement of urine and serum osmolarity include all of the following except:
calculate the free water clearance from the following results: Urine volume in 6 hours: 720ml; urine osmolarity 225 mosm; plasma osmolarity :300 mosm
to provide an accurate measure of renal blood flow, a test substance should be completely :
cleared on each content with functional renal tissue
given the following date calculate the effective renal plasma flow :
urine volume in 2 hours :240 ml;urine PAH: 150mg/dl; plasma PAH: 0.5 mg/dl
renal tubular acidosis can be caused by the:
inability to produce an acidic urine due to impaired production of ammonia
tests performed to detect renal tubular acidosis after administering an ammonium chloride load include all of the following except:
A 44 year old man diagnosed with acute tubular necrosis has a blood level of 100 mg/dl. A 2+ urine glucose is also reported.
A. state the renal threshold for glucose.
B. what is the significance of the positive urine glucose and normal blood glucose?
A. 160 to 180 mg/dl
B. renal tubular reabsorption is impaired
A patient develops a sudden drop in blood pressure.
A. Diagram the reaction that takes place to ensure adequate blood pressure within the nephrons.
B. how do these reactions increase blood volume?
C. when blood pressure returns to normal, how does the kidney respond?
A. juxtaglomerular apparatus-> Macula densa > justaglomerular apparatus> Angiotensinogen > renin > angiotensin 1 > Angiotensin 2
B. vasodilation and constriction, increased sodium reabsorption, increased aldosterone and ADH Production.
C. production of renin deceases, and this reduces the actions of the renin-angiotensin -aldosterone system.
A physician would like to prescribe a nephrotoxic antibiotic for a 60 year old man weighing 80 kg. the patient has a serum creatinine level of 1.0mg/dl.
A. How can he physician determine whether it is safe to prescribe this medication before the patient leaves the office
B.can the medication be prescribed to this patient with a reasonable assurance of safety.
C. A creatinine clearance was also run on the patient with the following results: serum creatinine .9 mg/dl; urine creatinine ,190 mg/dl; 24 hour urine volume, 720 ml. should the patient continue to take the medication? justify your answer.
A. the physician can calculate the approximate creatinine clearance using the cockcroft-gault formula.
B. yes, the measured creatinine clearance is 80 ml/min a normal range for a male and female.
C. yes, the measured creatinine clearance is 86 ml/min normal for this patient.
A laboratory is obtaining erratic serum osmolarity results on a patient who is being monitored at 6 am, 12 pm, 6pm, and 12 am . osmolarities are not performed on the night shift; therefore , the midnight specimen is run at the same time as the 6 am specimen.
A. what two reasons could account for these discrepancies?
B. If the laboratory is using a freezing point osmometer, would these discrepancies still occur? why or why not?
C. if a friend was secretly bringing the patient a pint of whiskey every night , would this affect the results? explain your answer?
A.serum from the midnight specimen is not being separated from the clot and refrigerated in a timely manner.
B. yes, lactic acid effects both cryoscopic and vapor pressure osmolarity.
C. If the laboratory is using a cryoscopic osmometer, results will be effected by alcohol ingestion; vapor pressure results would not be affected and could be used as a comparison.
following overnight (6 pm to 8 am) fluid deprivation, the urine to serum osmolarity ratio in a patient who is exhibiting polyuria and polydipsia is 1:1 the ratio remains the same when a second specimen is tested at 10 am. vasopressin is then administered subcutaneously to the patient, and the fluid deprivation is continued until 2 pm, when another specimen is tested.
A. what disorder do these symptoms and initial laboratory results indicate?
B. if the urine to serum osmolarity ratio on the 2 pm specimen is 3:1, what is the underlying cause of the paient's disorder?
C. If the urine to serum osmolarity ratio on the 2 pm specimen remains 1:1, what is the underlying cause of the patient's disorder.
A. Diabetes insipidus
B. decreased production of ADH
C. lack of tubular response to ADH
Define the term ultrafiltrate of plasma
ultrafiltrate of plasma is when the nephron forms a filtrate of protein free plasma. It occurs across the glomerular capilliaries passing through the three cellular layer which are the capillary wall membrane, the basement membrane, and the visceral epithelium of the bowmans capsule. which then results in a hydrostatic pressure within the capillary which pushes the water and solutes across the filtration membrane. (filtrate reflects the plasma except for large molecules and cells)
which ion is freely filtered by the glomerulas and must be reabsorbed to maintain a proper PH?
studies have shown that increase in _________ occur before an increase in creatinine in cases of acute renal failure.
in the______ method for determining creatinine concentration the resulting red orange complex known as __________ complex absorbs light in the 480 to 520 nm range.
elevated levels of creatinine may be caused by __________
enlarged prostate gland
elevated levels of __________ may lead to a condition know as ________ which can lead to painful joints
uric acid and gout
A patient presents with protienuira, hematuria and casts. the patient serum has elevated levels of BUN, creatinine and phosporus; serum calcium is decrease. these symptoms are closely associated with....
Acute renal failure
the six main function of the kidney as follows?
regulation of fluid and electrolyte to balance
excretion of waste products of protein metabolism
in the urine formation the nephron has functional units of the kidneys which contains 5 parts they are?
glomerulus, proximal convoluted tuble,loop of henley, distal convoluted tuble, collecting duct
in the glomerulus of the basement membrane why is it semi permeable
it filters everything except cells and large molecules.
the proximal secretes a variety of ?
organic acids and bases, as well as hydrogen, ammonium and drugs.
descending loop of henley is freely permeable to water B/C?
passive reabsorption of water in the osmotic gradient of the medulla
what is it called when the descending loop of henley is relatively impermeable to water and actively reabsorbs chloride and passively reabsorbs sodium and urea this is called what?
diluting segment because of the loss of salt without water in the final urine.
the primary function of the convoluted tubule is to make?
fine adjustments to achieve acid base equilibrium and electrolyte balance.
If the acid base equilibrium and electrolyte balance is responsive to aldosterone that is secreted by the adrenal cortex. what does this result in?
it results in a reabsorption of sodium and secretion of potassium and hydrogen of the distal convoluted tubule.
hydrogen secretion is involved in what regeneration of the distal convoluted tubule.
bicarbonate regeneration (acid base balance) and ammonium secretion.
the collecting duct is also under the influance of ?
the collecting duct is under the influence of aldosterone (sodium reabsorption) and another hormone called ADH (antidiuretic hormone)
ADH is produced by? and stimulated by in the collecting duct?
ADH is produced by the lower pituitary gland and is stimulated by increase blood osmolality or decrease blood volume.
In the presence of ADH water is ____________ in the collecting duct. In the absence of ADH water is?
In it's presence water is permeable in the collecting duct (reabsorbs) , and in its absence , water is impermeable (excreted)
steps in how the final urine flows.
the urine flows from the collecting duct (cortex) of the nephron to larger connecting ducts (medulla) which coalesce to form a central duct in the renal pyramids. these then drain through the papilla into the renal pelvis and finally into the ureters.
( collecting duct > medulla >central duct in the renal pyramids >papillla >renal pelvis >ureters
what are the cells in the afferent and efferent arterioles that produces renin? (IN the collecting duct)
what is renin?
it is a peptide hormone that initiates a hormonal cascade that ultimately produces Angiogenesis 2 .
which function out of the 6 function is this?
the human kidney has the ability to produce highly concentrated or dilute urine, ranging from 50 mOsm/kg to 1200 mOsm/kg.
regulation of fluid and electrolyte balance.
with dehydration or low water reserves extremely concentrated urine is produced to?
converse(reversed) body water
what does increased blood osmolality or low blood volume initiate?
1. secretion of AHD which increases renal tubular reabsorption of water (collecting Duct)
2. thirst, which increases fluid intake and is under the regulation of the thirst center in the hypothalamus.
explain renin ?
renin is produced in the renal medulla whenever extracellular fluid decreases, it serves as vasoconstrictor to increase blood pressure and also is the initial component in the renin- angiotensin-aldosterone feed back system.
what is erythropoietin?
Erythropoietin production is regulated by blood oxygen levels. It increases production of red blood cells in the bone marrow. Erythropoietin is produced in cells next to the proximal tubule.
ion equilibrium of sodium ?
primary extracellular cation is filtered by the glomerulus with 70% reabsorption in proximal tubule. Reabsorption controlled by the aldosterone in distal tubule and collecting duct.
Ion equilibrium of potassium
main intracellular cation is actively reabsorbed throughout the nephron (except descending loop of henley) excretion is controlled by aldosterone (distal convoluted tubule and collecting duct)
Ion equilibrium of phosphate, calcium, and magnesium.
All exist in protein and non-protein bound forms. non- protein bound forms are filtered by the glomerulus and reabsorbed by the proximal tubule. reabsorption is under the influence of PTH (parathyroid hormone)
in the regulation of acid balance the kidneys should maintain a normal blood PH of ?
they should maintain a normal Ph of 7.4 by their buffering abilities.
what ion is freely filtered at the glomerulus and must be reabsorbed to maintain a proper ph.
the secretion of what ion from metebolism and dietary intake by the renal tubular cells prevents the bicarbonate ion from being lost in the urine (regeneration of bicarbonate ions)
the secretion of excess hydrogen ion
how many percent of the filtered bicarbonate ion is reabsorbed in this way once the bicarbonate is in the lumen of the renal tubules.
what is the process of returning the pH to its optimal level?
the carbon dioxide diffuses into the renal tubular cells, where it is reconverted by carbonic anhydrase to carbonic acid. the carbonic acid breaks down to hydrogen (excreted) and regenerated bicarbonate (absorbed). The bicarbonate enters the blood thus helping to return pH to its optimal level.
what are two other method of excretion of the kidney?
1. hydrogen is combined with filtered phosphate ion (HPO4 ^2-) and excreted
2. ammonia (NH3) reacts with secreted hydrogen to form ammonium (NH4+) and excreted
An important function of the kidneys is the excretion of nonprotein nitrogen waste products form the metabolism of?
nucleic acids, amino acids, and proteins
what are the three main substances in the excretion of waste products of protein metabolism?
urea, creatinine and uric acid
explain the process of how urea works?
protein are broken down to amino acids which in turn are detoxified by the removal of the nitrogen atoms. Ammonia (toxic) is formed and converted into urea. Urea is then filtered by the glomerulus where approximately 50% is passively reabsorbed in the proximal tubule.
where is urea reabsorbed?
in the ascending loop of henley into the interstitial spaces of the medulla to maintain hyperosmolality.
the creatinine is at a constant level in the ?
a constant level in the blood and reflects the total muscle mass. (higher in males then females)
describe the process of how creatinine is filtered?
creatinine is filtered by the glomerulas and is not reabsorbed by the tubules. A small amount is secreted by the kidney tubules at high serum concentration.
describe the filtration process of uric acid ?
uric acid is filtered by the glomerulus and goes through a cycle of reabsorption and secretion until only 10% of the original filtrate is excreted.
the glomerulus has a semi-permeable membrane with a molecular cut-off of 70,000. what is this called?
what charge does the protein have?
they only have a negatively charged that repels negatively charged molecules such as protein.
what does a clearance test measure?
the clearance test measures the rate at which the kidneys are able to clear a substance from the blood.
An ideal substances to measure clearance should be ?
it should neither be reabsorbed nor secreted by the tubules
what happens if their is a secretion of the renal tubules?
the results would be a result in a falsely increased GFR
what are the current test used to measure clearance
creatinine, inulin, beta2-microglobulin, cystatin c and radioisotopes.
what is inulin?
is a stable polymer of fructose that is neither reabsorbed nor secreted by the tubules. which means a result is an accurate GFR determination.
why is inulin not used to assist GFR?
there is a disadvantage of this method includes the technical difficulties in analysis and the fact that it requires intravenous infusion at a constant rate throughout the test procedure
what disease can you detect with increased Beta2 -microglobulin in urine can be used to monitor GFR as a marker of ?
glomerular disease , ( especially tubular proteinuria)
is a small endogenous peptide (MW of 11,800), which os easily filtered by the glomerulus.
define Cystain C?
cystain C is a plasma protein (a protease inhibitor) which is freely filtered by the glomerulus and is produced in constant amounts and does not very with gender and age.
an increase in cystain C is present before an increase in creatinine in cases of what?
acute renal failure
what are the disadvantage of using creatinine?
some creatinine is secreted by tubules. secretion increases as serum concentration increases.
some chromagen are present in human serum that react with the test giving falsely elevated serum concentrations.
bacteria can metabolize creatinine in urine giving falsely elevated lower values if the test is not performed in a timely manner.
increased dietary intake of meat and vigorous exercise can falsely elevate the urine creatinine concentration and result in a higher GRF's.
patients with muscle-wasting disease should not be assessed by this method.
what is the formula for clearance creatinine test?
(CL) (P) = (u) (V)/(P) * 1.73/A\
Cl = creatinine clearance
U= urine creatinine
V= urine volume excreted in 24 hrs (ml/min)
1.73/A = normalization factor for body surface area m^2 (nomgram)
the lab receives a 24 hour urine sample from a 30 year old male. He is 6'4' and weights 250lbs; body surface area is 2.50. these sample volume is 900 ml. the plasma creatinine is 1.1 mg/dl and urine creatinine is 125 mg/dl. calculate the clearance results:
if the results are lowered then expected and the patient has a creatinine serum value in the normal range what should de done?
If the test comes back the same what are some of the possible explanation for results?
cl=(125mg/dl) (900ml/24hr 1h/60min)
Cl (corrected) = 71ml/min * 1.73m^2 /2.50 M^2
repeat the test.
1. not all of the urine was collected in the 24 hr period (some discarded)
2. not a true 24 hour sample
3. sample was not preserved correctly and therefore some of the creatinine has degraded.
GFR and diseases.1. what is your creatinine clearance was 60-89 ml/min/1.73m^2
2. what is it was 30-59 ml/min/1.73m^2
3. what if it is 15-29 ml/min/1.73m^2
1. mildly decreased kidney function
2. moderately decreased kidney function
3. severely decrease kidney function
what is colligative properties?
a solution are directly related to the number of particles per unit volume or mass of solvent.
A one mole solution will?
Decrease the freezing point 1.86 degrees C
decrease the vapor pressure .3 mm hg
increase osmotic pressure 22.4 atmosperes
increase boiling point .52 degrees C
most clinical laboratories utilize the colligative properties of freezing point depression to measure what ?
osmolality of a specimen
vapor point depression is what?
vapor point depression is the second most common instrument to measure the osmolality of a specimen is vapor point depression.
what does the vapor pressure osmometers actually measure ?
the depression of the dew point of solution rather then vapor pressure.
the vapor pressure osmolality technique is much less precise then the freezing point method and consequently greater then 80% of the labs in CAP surveys use what?
the freezing point depression cryscopic osmometer.
in patients with renal tubular deficiency, the ratio is less then normal b/c?
they have lost the concentrating ability of the kidneys
in diebetes insipidus, the patients lack what and what is the ratio in that?
the patients lack ADH and the range is .2 to .7 even after water restriction/
the jeffe method uses what ?
spectrophotometric-end point analysis of the reaction btw creatnine and picrate in an alkaline medium resulting in the function of a red-orange complex (janovski complex ) which absorbs light in the range of 480 to 520NM
what is the disadvantage of the jeffe reaction when analysising it at the end?
cross reactivity with non creatinine chromogens such as proteins, acetoacetate, glucose, ascorbic acid, quandine, acetone, alpha-ketoacids, urea, and certain antibiotic. they also react with picrate giving falsely elevated creatinine levels.
which method eliminates some of these interfering substances b/c the initial reaction rate is primarily due to the reaction of creatinine and picrate.
spectrophotometric kinetic method
what interferes with the enzymatic methods?
biliruben, creatinine, dopamine, ascorbic acid, and sarcosine interfere with the enzymatic methods
elevated levels of creatinine is caused by?
poor kidney function, kidney infection, something blocking the flow of urine (such as enlarged prostate gland or a kidney stone), dehydration, heart failure, decreased blood flow to the kidneys, pregnancy with high blood pressure (preeclampsia or toxemia of pregnancy), some medicines can cause the creatinine level to be higher than normal, such as blood pressure meds including ACE inhibitors (such as captopril and enalapril) nonsteroidal anti-flammatory drugs such as ibuprofen or neproxen) diuretics such as furosemide, antibiotics including aminoglycosides (for example, gentamicin) and cephalosporins (for example, cefoxitin and cimetidine)
lower than normal creatinine levels may be caused by ?
muscle disease such as myasthenia gravis or muscular dystrophy.
where is urea formed ? and were is it carried out to?
in liver and carried by the blood to the kidneys for excretion.
due to urea cleared from the bloodstream by the kidneys, a test measuring how much urea nitrogen remains in the blood can be used as a test for ?
what other things can cause BUN alterations other than renal disease?
protein breakdown, hydration status, and liver disease/failure.
what are the reference value?
Adult 7-20 mg/100 ml; men may have slightly higher values than women, pregnancy : values slightly lower than adult range, newborn: values slightly increased due to lack of renal concentration
increased protein metabolism due to ?
hemorrhage into the gastrointestinal tract, acute myocardial infarction
excessive protein intake or protein catabolism
A decreased BUN may be seen in?
liver failure, malnutrion, anabolic steroid use, overhydration, which can result from prolonged intrevenous fluids, pregnancy (due to increased plasma volume), impaired nutrient absorption, syndrome of inappropriate anti-diuretic secretion(SIADH)
what is the formula for converting BUN values to urea concentrations?
60= mw of urea (CO(NH^2)^2)
urea nitrogen is 46.6% by weight of urea (28 divided by 60)
most method used to measure urea utilize an enzymatic reaction with?
Urease b/c of the high specificity of urease of urea
the dupont (glutamate Dehydrogenase-GLDH) utilizes a enzyme assay involving what ? they can be spectrophotometrically monitored at ?
how can it decrease accuracy?
the endogenous enzymes in the patients specimen can compete oxidizing the NADH, thus decreasing accuracy.
the method utilizes the production of the alkaline NH^4 ion with the addition of a PH indicator dye. The ph indicator dye for vitros method is ? and absorbs light at ?
merocyamine light at 520nm
the uric acid test are used to evaluate what in the blood and urine? what can it also detect beside these ?
for blood it is gout and urine it is kidney stone. it can also detect disorders that effect the body's production of uric acid and to help measure the level of kidney functioning.
if the liver produces too much uric acid or the kidneys excrete too little, the patient will have too much uric acid in the blood. this condition is know as?
how do you get kidney stones?
supersaturated uric acid in the urine (uricosuria) can crystalize to form kidney stones that may block the tubes that lead from the kidney to the bladder (the ureters)
what are the normal value for blood in male and female. and what is it in 24hours?
blood; male 2.1-8.5 mg/dl; female 2.0-6.6 mg/dl. values maybe slightly higher in the elderly. in 24 hours urine 250-750 mg/hours
what is the critical value for the blood test for uric acid?
uric acid is higher than 12 miligrams per deciliters
increased uric acid can result from?
eating foods that are high in purine.
anchovies, beef kidneys, herring game meats, sardines, brains, mackerel, gravy, liver, meat extracts, scallops, overproduction may also be caused by gout. genetic disorder of purine metabolism, metastatic cancer, destruction of red blood cells, luekemia, or cancer chemotherepy.
decreased excretion of uric acid is seen in?
chronic kidney disease, low thyroid, toxemia of pregency, alcoholism, patient with gout excrete less then half the uric acid in their blood as other persons. only 10-15% of the total cases of hyperuricemia , however,are caused by gout, drugs allopurinal or probenecid for treatment of gout
uric acid enzyme fall into what three groups?
uricase enzyme reaction, phosphotungst acid colorimetric, hplc (high performance liquid chromatography)
explain how the uric acid is quantitated in less then 6 mins?
by adding an internal standard to plasma sample and injecting it onto a reverse phase HPLC column.
how is uric acid idnetified by ?
relative retention time to internal standard snd quantitated by an absorbance at 254 nm (UV)
, most commonly found in children and young adults following a respiratory tract illness due to group A streptococcus. Immune complexes are formed and deposited on the glomerular membrane with the resultant membrane damage (membrane leaky). If treated, reversible. the symptoms are the patient presents oliguria , hematuria, edema, and hypertension. labs indicate marked increase in RBC's (hematuria) , RBC casts, proteinuria, increased BUN, increased serum creatinine, increased ASO serum titer, and decreased GFR. what renal disorder does this patient have?
Acute glomerulonephritis (glomerulus)
the integrity of the glomerular membrane is lost causing leakage of large molecules of protein and lipids. some causes are glomerulonephritis (late stage) , infection, toxin, allergens, preeclampsis, and systemic disease such as amyloidosis, carcinoma, SLE (systemic lupus erthematosus, and diabetes. the symptoms that this patient is having is massive proteinuria (greater then 3.5g/day) edema, hypoalbuminemia, hyperlipidemia, lipiduria. labs results are urinalysis shows massive increase in protein, urinary fat droplets, oval fat bodies, renal tubular epithelial cells, waxy and fatty casts, and increase in RBC's. what disorder does this patient have?
Acute renal failure is usually classified as pre-renal, renal , or post-renal. 1. if the patient has decreased renal blood flow such as shronic heart failure, salt and water depletion, vomiting, diarrhea, diuresis, sweating, shock, burns. what is this classified under? 2. impaired kidney function such as acute tubular necrosis such as renal vasoconstriction, drugs , and toxins; glomerulonephritic and vasculitis. this is classified under? any obstruction of urinary tract. this is classified under?
1. pre-renal Azotemia
2. renal azotemia
3. post renal azotemia
the patient has symptoms of primary initial symptoms (excluding the symptoms of the underlying cause) is oliguria or anuria. symptoms are reversible. labs urinalyisis shows proteinuira, hematura, and cast. the serum BUN, creatinine, and phosphorus became makredly elevated and with progression of the pathological process, metabloic acidosis can result. serum calcium levels decrease. in pre-renal azotemia BUN/ creatinine ratio greater then 20:1. what disease does this patient have by observing the symptoms and lab reports.
Acute renal failure
the patient has a primary renal causes include glomerular disease, renal vascular disease, chronic pyelonephritis, toxins, kidney stones, radiation, chemothrepy. systemic causes include diabetes mellitus, gout, benign prostatic hypertrophy, amyloidosis and congenital anomalies. the symptoms are progressive loss of renal function. 50% of nephron loss before increase in serum BUN and creatinine is noted. symptoms irreversible. labs end stage of disease reveals anemia (decrease production of erythropoietin
chronic renal failure
infection of the kidneys. it is most frequently seen in women b/c of untreated cystitis or lower urnary tract infection, but it can also occur secondary to obstruction that allows bacteria to remain in the kidneys. symptoms include fever, extreme lower back pain. if left untreated can progress to Chronic renal function. labs WBC casts, bacteruria, and possibly proteinuria and hematuria. WBC casts distinguish pylelonephritis form cystitis (bladder infection) whatt disorder does this patient have ?
A 3 year old girl brought to pediatricain for increasing facial and peripheral edema of eight days duration. urine -4.2g protein/24hrs, hyline casts, oval fat bodies, ASO (antistreptolysin-o) negative, creatinine -1.0mg/dl. serum protein-6.5g/dl; albumin 3.0 g/dl . what test look abnormal? what do you suspect is the problem?
protein look abnormal, hyaline casts, oval fat bodies.
the problem is nephrotic syndrome.
dysmorphic RBC casts would be a significant finding with all of the following except?
occassional episodes of miscropic hematuria over periods of 20 or more years are seen with?
the presence of fatty casts is associated with all of the following except:
neprogenic diabetes insipidus
An inherited or acquired disorder producing a generalized defect in tubular reabsorption is :
the presence of renal tubular epithelial cells and casts is an indication of ?
Acute tubular necrosis
urinalysis on a patient being evaluated for renal calculi would be most beneficial if it is showed:
An unidentified fluid is received in the laboratory with a request to determine if the fluid is urine or another body fluid. using routine laboratory tests , what tests would determine that the fluid is most probably urine?
urea and creatinine
A patient presenting with polyuria, nocturia, polydipsia, and a high urine specific gravity is exhibiting symptoms of what disorder?
true or false disposable containers with a capacity of 50 ml are recommended for the collection of specimen for routine urinalysis.
A urine specimen for routine urinalysis would be rejected by the laboratory because :
the specimen and the accompanying requisition did not match.
An unpreserved specimen collected at 8 am and remaining at room temp. until the afternoon shift arrives can be expected to have:
decreased glucose and ketones
increased bacteria and nitrate
what three changes wiil effect the results of the microscopic eximination of urine if it is not tested within 2 hours ?
increased bacteria , decreased red blood cells, decreased casts
for the best preservation of urinary sediments, the preservatives of choice are?
boric acid and thymol
true or false: A properly labeled urine specimen for routine urinalysis delivered to the laboratory in a gray top blood collection tube can be used.
three types of urine specimen that would be acceptable for culture to diagnose a bladder infection include all of the following except:
A negative urine pregnancy test performed on a random specimen may need to be repeated using a :
first morning specimen
what type of urine specimen should be collected from a patient who complains painful urination and the physician has ordered a routine urinalysis and urine culture?
midstream clean catch
A yellow-brown specimen that produces a yellow foam when shaken can be suspected of containing :
specimen that contain intact RBC's can be visually distinguished from those that contain hemoglobin because:
RBC's produces a cloudy specimen
After eating beets purchased at the local farmers market, Mrs. williams notices that her urine is red, but Mr. william's urine remains yellow . the williamses should:
not be concerned b/c only mrs. williams is genetically susceptible to produce red urine from beets
specimen from the patients receiving treatment for urinary tract infections frequently appear:
viscous and orange
freshly voided normal urine is usually clear, however, if it is alkaline, a turbidity may be present due to:
Amorphous phosphates and carbonates
microscopic examination of a clear urine that produces a pink precipitates after refrigeration will show:
under what condition will a port-wine urine color be observed in a urine specimen?
urine contains porphyrins
which of the following specific gravity would be most likely to correlate with a dark yellow urine?
true or false : urine specific gravity is equally influenced by the presence of glucose and sodium?
in what circumstances might a sediment be slightly warmed prior to microscopic examination.
to dissolves amorphous urates
A urine specific gravity measured by refractometer is 1.029 and the temp of the urine is 14 degrees C. the specific gravity should be reported as :
An alkaline urine turns black upon standing develops a cloudy white precipitate, and has a specific gravity of 1.012. the major concern about this specimen would be
A urine specimen with a specimen with a specific gravity of 1.008 has been diluted 1:5 the actual specific gravity is :
the method for determining a urine specific gravity that is based on the principle that the frequently of a sound wave entering a solution changes in proportion to the density of the solution is :
harmonic oscillation densitometry.
true or false : specific gravity is more diagnostic value than osmolarity in evaluating renal concentration ability
the microscopic of a cloudy amber urine is reported as rare WBC's and epithelial cells. what does this suggest
possible mix up of specimen and sediments
A specimen with a strong ammonia odor and a heavy white precipitate when it arrives in the laboratory may require?
collection of a fresh specimen
urinalysis provides information concerning?
the state of the kidney and urinary tract.
information about metabolic or systemic disorder
an normal individual would have how many mls of water ? how much can it range from?
1200 to 1500 mls urine output in 24hour period
however it can range from 600 to 2000 ml/24 hour
what type of urinalysis is performed?
dipstick urinalysis, microscopic (routine or basic) urinalysis, cytodiagnostic urinalysis
urine is composed of organic and inorganic compounds dissolved in water. what are the organic compounds, inorganic , other stuff and the formed elements
organic : urea, creatinine, uric acid
inorganic : chloride, potassium, sodium
other: hormones, vitamins, medications
formed elements : cells, casts, crystals, mucus, bacteria
how should the specimen be collected:
clean, sterile container that has a tightly fitting lid to prevent spillage, evaporation, and contamination
If the test is not done in 2hours then what do you do with the test?
refrigerate or have an appropriate chemical preservatives added if cannot be delivered or tested within two hours.
after taking it out from the refrigrater what should you do?
allow the specimen to return to room temp prior to chemical testing so the reagent strips can dissolve amorphous urates and phosphates which may obscure microscopic analysis and to correct specific gravity reading when using urinometer.
what happens to the unpreserved urine?
increase in ph, nitrate, bacteria
decrease in glucose, ketones, biliruben, urobilinogen, cells, casts
first morning specimen
routine screening, pregnancy tests, orthostatic proteinuria, cytological study
not measured as a part of a urinalysis. however, in certain conditions the volume in 24 hours is a valuable aid to clinical diagnosis
cessation of urine flow. damage to the kidneys: decrease in blood flow to the kidneys, renal failure.
increased in daily urine volume. often associated wih diabetes mellitus and diabetes insipidus; maybe artificially induced by the use of diuretics, caffeine or alcohol.
defect in pancreatic production of insulin or in the function of insulin resulting in an increased body glucose concentration. urine will have a high specific gravity
decrease in the production or function of antidiuretic hormone (ADH). urine will have a low specific gravity
normal- faint aromatic due to presence of certain volatile acids(not part of routine urinalysis
Abnormal odor maybe due to
bacterial acton-strong ammonia smell
urinary tract infection- putrid or foul
excess ketones- fruity
maple syrup urine disease- maple syrup smell (inherited matabolic disorder)
refers to the the transparency /turbidity of urine specimen. visually inspect the mixed specimen while holding it in front of the light source
Alkline urine- maybe due to amorphous phoshates and carbonate.
Acidic urine- maybe due to amorphous urates (brick-dust due to uroerythrin), calcium oxalate and uric acid crystals, semen, fecal contamination, radiographic contrast, talcum powder, and vaginal creams
Abnormal cloudiness is due to:
WBCs, RBCs, bacteria, yeast, abnormal crystals, nonsquamous epithelial cells, lymph fluid, lipids. ether can be used to dissolve lipid and lymph fluid.
failure to mix a specimen prior to inserting the reagent strips will primarily affect the:
testing a refrigerated specimen that has not warmed to room temperture will adversely affect?
quality control of reagent strips is performed:
using positive and negative controls
when results are questionable
at least once every 24 hours
all of the following are important to protect the integrity of reagent strips except:
removing the desiccent from the bottle
in the laboratory, a primary consideration associated with ph is :
identification of urinary crystals and determination of specimen acceptibility
indiacate the source of the following proteinurais by placing a 1 for prerenal 2 for renal 3. for postrenal in front of the condition.
A. microalbuninuria = renal ; B. acute phase reaction= prerenal; C. pre-eclampsia= renal; D. vaginal inflammation= post-renal E. multiple myelome = prerenal F. orthostatic proteinuria= renal G. prostatis = post renal
the principle of the protein error of indicative reaction is that?
albumin accepts hydrogen ions from the indicator
all of the following will cause false-positive protein reagent strip values except?
protein other then albumin
A patient with a 1+ protein reading in the afternoon is asked to submit a first morning specimen. the second specimen also has a 1+ protein. this patient is
negative for orthostatic proteinuria
testing for microalbuminuria is valuable for monitoring patients with:
hypertension, diabetes mellitus, cardiovascular disease risk
all of the following are true for the micral- test for microalbumin except:
two blue bands are formed on the strips
All of the following are true for the immunodip test for microalbumin except:
bound antibody migrates further than unbound antibody
the principle of the protein-low reagent pad on the multistix pro is the :
binding to the albumin to sulphonphtalein dye
the principle of the creatinine reagent pad on microalbumin reagent strips is the:
A patient with normal blood glucose and a positive urine glucose should be further checked for?
A positive clinitest and a negative reagent strip glucose are indicative of
nonglucose reducing substances
the three intermediate products of fat metabolism include all of the following except:
the most significant reagent strips test that is associated with a positive ketone result is :
urinalysis on a patient with a severe back and abdominal pain is frequently performed to check for:
place the appropriate number or numbers in front of each of the following statement. use both numbers for an answer if needed 1.hemoglobinuria 2. myoglobinuria
A. associated with tranfusion reactions = hemoglobinuira; B. clear, red urine and pale yellow plasma= myoglobinuria; C. clear red urine and red plasma= hemoglobinuria; D. Associated with rhabdomylosis= myoglobinuira ; E. precipitated by ammonium sulfate= hemoglobinuira; F. not precipitated by ammonium sulfate= myoglobinuria; G. produced hemoisiderin granules in urinary sediments= hemoglobinuria; H. associated with acute renal failure= hemoglobinuria
list the following products of hemoglobin degradation in the correct order by placing numbers 1-4 in front of them
1. unconjugated biliruben, 2. conjugated bilirubin, 3. urobilinogen and stercobiligen 4. urobilin
the purpose of the special mat supplied with the ictotest tablets is that :
Biliruben reamins on the surface of the mat
the primary problem with urobilinogen tests using Ehrlish reagent is :
positive reaction with Ehrlich reactive substances
In the watson-shwartz differentiation test, the substances not extracted into butonol is:
A positive nitrite test and a negative leukocyte esterase test is an indication of a:
vaginal yeast infection
the principle of the reagent strip for specific gravity uses the dissociation constant of a /an
variation in the microscopic analysis of urine include all of the following except:
identification of formed elements
all of following can cause false negative microscopic results except:
using midstream clean catch specimen
when using the glass slide and coverslip method, which of the following might be missed if the coverslip is overflowed
which of the folllowing should be used to reduce light intensity in bright-field microscopy?
when pyuria is detected in a sediment, the slide should be carefully checked for the presence of
forms of transitional epithelial cells include all of the following except:
catheterization and pyleonephritis
A primary characteritics used to identify renal tubular epithial cells is ?
eccentrically located nucleus
A structure believed to be an oval fat body produced a maltase cross formation under polarized light but does not stain with sudan III. the structure
A person submitting a urine specimen following a strenous exercise routine can normally have all of the following in the sediment except:
proir to identifying an RBC cast, all of the following should be observed except:
intact RBCs in the casts
the presence of fatty casts is associated with:
nephrotic syndrome, crush injuries, diabetes mellitus
the observation of broad casts represents:
destruction of tubular cells and formation in the collecting ducts
match the following crystals seen in acidic urine with their decription . identifying characteristics ; Amorphous urates
calcium oxalate monhydrate
calcium oxalate dihydrate
Amorphous urates = pink sediments
uric acid= yellow brown whetstones
calcium oxalate monhydrate = ovoid
calcium oxalate dihydrate= envelopes
match the following crystals seen in alkaline urine with their description. identifying characteristics : triple phosphate
triple phosphate = coffin lid
amorphous phosphate = white precipitate
calcium phosphate = thin prism
ammonium biurate = thorny precipitate
calcium carbonate = dumbbell shape
match the abnormal crystals with their description. identifying characteristics: cystine
cystain= hexagonal plates
tyrosine= fine needle seen in liver disease
cholesterol= notoched corners
leucine = concentric circles, radical striations
ampicillian= bundles followed by refrigeration
radiographic dye= flat plates, high specific gravity
bilirubin= bright yellow clumps
match the following types of microscopy with their description
bright- field= low refractive index objects may be overlooked
phase = forms halo of light around object
polarized =objects split light into two beams
dark-field=indirect light is reflected off the object
fluorescent= detects specific wavelength of light emitted from objects
interference contrast= three- dimensional images
place the appropriate letter in fornt of the statement that best describes CSF specimen in these two condition
A. traumatic tap
B. intracranial hemorrhage
even distribution of blood in all tubes= intracranial hemorrhage
Xanthochromic of blood in tube 1 is greater= intracranial hemorrhage
concentration of blood in tube 1 is greater then in tube 3 = truamatic tap
specimen contains clots= truamatic tube
given the following information, calculate the csf wbc count; Cells counted 80: dilution 1:10; large neubauer square counted 10
The purpose of adding albumin to CSF before cytocentrifugation is to :
increase the cell yield and decrease the cellular distortion
the primary concern when pleocytosis of neutrophil and lymphocytes is found in the CSF is :
following a CNS diagnostic procedure, which might be seen in the CSF?
choroidal cells, ependymal cells, spindle-shaped cells
in the plasma, the second most prevalent protein is IgG: in CSf, the second most prevalent protein is :
given the following results, calculate the IgG index: CSF IgG, 50 mg/dl; serum IgG, 2 gm. dl ; CSF albumin, 70 mg/dl; serum albumin, 5 gm/dl
A CSf glucose of 15 mg/dl, WBC count of 5000, 90% neutrophils and protein of 80 mg/dl is suggestive of:
measurement of which of the following can be replaced by the CSF glutamine analysis in children with reye syndrome?
All of the following statement are true about cryptoccocal meningitis except?
the WBC count is over 2000
sterheimer- malbin stain- consist of crystals violet and safranin. identifies WBC's, epithelial cells, and casts
diffrentiates WBC's and renal tubular epithelials (RTE) by enhancing nuclear details
bright field microscopy
corrects light adjustments is essential because translucent element such as hyline cast, mucus threads are easily overlooked
element that have low refractive index like mucus threads, hyline casts are better visualized; halo effect is produced b/c of the reterdation of ligh rays diffused by the object in focus
oval fat bodies , fatty casts, and crystals produced characteristic colors and maltese cross by rotation of the path of light
they are associated with damage to glomerular mambrane or vascular injury within genito-urinary track.
RBC's under the scope
is smooth, non-nucleated biconcave disks, approximately 7um , concentrated-crenated
may be confused with WBC, yeast cell, oil droplets
dysmorphic cells (RBC with protrusions or fregments), associated with glomerular bleeding
what kind of diseases are RBCs associated with?
glomerulonephritis, acute infection, toxic and immunologic reactions, malignancies, circulatory overload, renal calculi, physiologic causes including exercise
seen in pyleonephritis , cystitis, prostatitis, urethritis may be seen in glomerulonephritis, lupus, interstitial nephritis, tumors may be observed in fevers and after strenous exercise
lyses in dilute alkaline urine (wbcs appearance in old urine) (observes bownian motion
squamous epithelial cells
most frequently seen and less significant
comes from male and female urethras
largest cells with abundant, irregular cytoplasm and central nucleus the size of RBC
comes from linning the pelvis, bladder, and upper urethra. smaller than squamous and are spherical, caudate or polyhedral
small central nucleus; larger number should be reported and sent to cytological examination for possible carcinoma
renal tubular epithelial (RTE)
large # seen in tubular necrosis
slightly larger than WBC
rectangular, columnar or polyhedral with single round eccentrically located nucleus
may contain bilirubin, melanin, hemosiderin
oval fat bodies
RTE with lipids and free floating fat droplets, confirm: sudan III and oil red O-orange red droplets (triglycerides and neutral fats) polorized light maltese cross if cholestrol is present
lipiduria associated with nephrotic syndrome
unique to the kidney
formed in the lumen of the distal convoluted and collecting ducts
parallel side and round ends
major constituents is tamm-horsfall protein
factors favoring formation
decreased renal flow
increased solute concentration
increased protein concentration
colorless, homogenous, nonrefractive, semiitransparent;
stain with sternheimer-malbin
phase contrast and interference microscopy are valuable tools
Increase number following strenous exercise, dehydration, heat
exposure and emotional stress
pathologically increased in glomerulonephritis, pyelonephriitis,
chronic renal disease,(CHF)
orange red matrix containing RBCs
refractile, more fragile than other casts
seen in glomerulonephritis
After contact sports
Asociated with pyelonephritis, acute insterstitial nephritis maybe seen in glomerulonephritis primary marker for distinguished upper UTI (pyelonephritis) from the lower UTI, accompanies bacteruria, refractile, exhibits granules, multilobed nuclei.
often seen with RBC and WBC casts, both glomerular and pyelonephritis where tubular damage is present.
distinguish from WBC cast by round nucleus, staining and phase contrast microscopy
RTE attached to protein matrix
fine the coarse granules and protein aggregates in protein matrix
results from the disintegration of cellular casts
can also be seen following stress, and strenous exercise
retractile, cracked sides, uneven edges b/c rigid casts are broken as they pass through tubules, extreme urine stasis, chronic renal failure
seen in conjuction with oval fat bodies, refractile, yellow brown oil droplets, accompanied proteinuria nephrotic syndrome, DM, toxic tubular necrosis, crush injuries
similar in appearance to hemoglobin casts -seen in myoglobinuria, after acute muscle damage
not normal to urine; can be seen with surface contamination, will multiple at room temp. significant when seen in a freshly voided specimen and when seen with WBC's, culture to identify organism
trichomonas vaginalis - flegellate with rapid movement, schistosoma haematobium- bladder parasites, pinworm ova- fecal contamination
seen in variety of shapes; alkali soluble
rhombic, four sided flat plates (whetstones), rosettes, wedges, usually yellow-brown, but may be colorless and six sided shape similar to cystine, highly birefringent under polarized light
found in luekemin patients undergoing therapy and sometime qout.
Amorphous urates ;
yellow-brown granules, tend to form in acid urine, soluble in 10% NAOH, microscopic pink color after centrifigation (brick dust)
uric acid crystals
yellow-brown-six sided shape
increased levels of purine and nucleic acid and in leukemia patients, increased levels pf purine and nucleic, increased levels of purines and nucleic acid in leukemia patients, lesch-nyhan syndrome and gout.
can be seen in neutral and rarely in alkaline urine
soluable in dilute HCL
dihydate- most common, colorlesss octahedral envelop, monohydrate-dumbbell shaped
both are birefringent under polarized light
finding of clumps of calcium oxalate crystals in fresh urine maybe related to the formation of renal calculi b/c majority of the renal calculi ar composed of calcium oxalate.