finals - non protein nitrogen Flashcards
1
Q
The term ___originated in the early days of clinical
chemistry when analytic methodology required removal of protein from a
specimen before analysis
A
nonprotein nitrogen (NPN)
2
Q
The concentration of nitrogen-containing compounds in this protein-free
filtrate was quantified
____
A
spectrophotometrically
3
Q
The concentration of nitrogen-containing compounds in this protein-free
filtrate was quantified spectrophotometrically by converting nitrogen to
___
A
ammonia
4
Q
The concentration of nitrogen-containing compounds in this protein-free
filtrate was quantified spectrophotometrically by converting nitrogen to
ammonia and subsequent reaction with what reagent?
A
Nessler’s reagent
5
Q
nessler’s reagent components
A
double iodide of potassium mercury
6
Q
end color of converting nitrogen to ammonia using nessler’s reagent
A
yellow
7
Q
nonprotein nitrogen (NPN)
The majority of these compounds arise from the catabolism of ___
A
proteins and amino acids
8
Q
list down the non protein nitrogen compounds
A
urea
amino acids
uric acid
creatinine
creatine
ammonia4
9
Q
Major excretory product of protein
metabolism
A
UREA
10
Q
Formed in the liver from amino groups (-NH2)
and free ammonia generated during protein
catabolism
A
urea
11
Q
Concentration of urea in the plasma is
determined by ___
A
renal function and perfusion,
the protein content of the diet,
and the rate of protein catabolism
12
Q
marker of dialysis
A
urea
13
Q
In severe liver damage, levels of urea
___.
A
decreases
14
Q
why do urea level decreases in liver damage?
A
ammonia is deaminated in liver from proteins that will subsequently turned as a urea, if there’s no liver that can deaminate ammonia to become urea, urea level will decrease
15
Q
It is used as a screening test for kidney
disease.
A
BLOOD UREA
NITROGEN (BUN)
16
Q
Major organic compound in the urine
A
BLOOD UREA
NITROGEN (BUN)
17
Q
Major inorganic solid in the urine
A
chloride
18
Q
Urea is readily removed by ___
A
dialysis
19
Q
____ Urea is excreted; 10% remain in the
blood
A
90%
20
Q
(<10% of the total BUN) are excreted through the ___
A
gastrointestinal (GI) tract and skin
21
Q
The concentration of urea in the plasma is
determined by the __
A
protein content of the diet,
the rate of protein catabolism,
and renal function and perfusion
22
Q
clinical application of BUN
A
evaluate renal function,
to assess hydration status,
to determine nitrogen balance,
to aid in the diagnosis of renal disease, and
to verify adequacy of dialysis
23
Q
oldest technique for urea determination
A
MICRO-KJELDAHL NESSLER
24
Q
end product of MICRO-KJELDAHL NESSLER
A
Dimercuric ammonium iodide
25
___ process
Mixture of sulfuric acid and phosphoric acid
Kjeldahl
26
a nesslerization with a use of enzyme
UREASE-NESSLER
METHOD
27
in UREASE-NESSLER
METHOD
urea is splitted into
carbon dioxide and nh3 (ammonia)
then the ammonia is subjected to nesslerization to produce dimercuric ammonium iodide
28
what is the coupling enzyme used in BUN enzymatic method; urease?
gldh - glutamic dehydrogenase
29
what is being measured in urease kinetic enzymatic method
the rate of disappearance of NAD to its reduced form NADH which is measured to 340 nm
30
a BUN method which is Greater specificity: More expensive
enzymatic kinetic method of urease
31
Greater specificity: More expensive
enzymatic kinetic method of urease
32
Urea is hydrolyzed to ammonium
carbonate by urease and ammonia
reacts with phenol and sodium
hypochlorite in an alkaline medium
forming a blue indophenol.
Urease Berthelot Method
33
in Urease Berthelot Method:
what elements do ammonia reacts with?
phenol and sodium hypochlorite
34
end product of Urease Berthelot Method:
blue indophenol.
35
Urea is hydrolyzed by
urease forming ammonia
which is then titrated
with a weak acid.
ENZYMATIC AND
ACID TITRATION
36
2 methods of ENZYMATIC AND
ACID TITRATION
a. Van Slyke Cullen
b. Urograph
37
DIRECT MEASUREMENT OF UREA measures
urea itself, no need to use urease to convert it to ammonia
38
DIRECT MEASUREMENT OF UREA measures
urea itself, no need to use urease to convert it to ammonia
however, it is only a what type of method?
colorimetric method
39
a method under DIRECT MEASUREMENT OF UREA
Diacetyl Monoxime Method (DAM)
40
in Diacetyl Monoxime Method (DAM)
Urea is made to react with diacetyl monoxime to produce a yellow diazine
derivative known as
Fearon's reaction
41
what is the end product color of Diacetyl Monoxime Method (DAM)
yellow diazine derivative
42
in Diacetyl Monoxime Method (DAM)
we are adding a color enhancer and to exclude the protein interferences called as ___
Arsenic thiosemicarbazide
43
comments for Diacetyl Monoxime Method (DAM)
inexpensive but lacks specificity since colorimetry
44
CONSIDERATION IN BUN DETERMINATION
The determination is affected by __.
high protein diet, hydration and other physiologic functions
45
CONSIDERATION IN BUN DETERMINATION
Whole blood should be ___ to
eliminate interferences of hemoglobin
deproteinized
46
CONSIDERATION IN BUN DETERMINATION
what anticoagulants are contraindicated in enzymatic methods.
Ammonium oxalate-containing anticoagulants
47
CONSIDERATION IN BUN DETERMINATION
Sodium fluoride and Citrate inhibits the action of __.
urease
48
CONSIDERATION IN BUN DETERMINATION
Upon prolonged standing, ammonia concentration in the sample rises____ times the original value due to enzymatic deamination of labile amide-like
glutamine
2-3 times
49
NORMAL VALUE of BUN
6-20 mg/dL (2.1 – 7.1 mmol/L)
8-23 mg/dl in stan bio
50
Normal value of BUN in 24hr urine
12-20g/dL
51
CONVERSION FACTOR of BUN
0.357
52
Urea nitrogen concentration can be converted to urea concentration by multiplying by ____
2.14
53
the enzymatic method that used pH indicator
indicator dye
54
proposed reference method of urea
isotope dilution mass spectrophotometry
55
quantification using isotopically labelled compounds measuring the fragments of urea
idms - isotope dilution mass spectrophotometry
56
___ is the principal waste product of muscular metabolism derived mainly from creatine (alpha-methyl guanidoacetic acid)
Creatinine
57
CREATININE
It is synthesized forming three amino acids (____)
methionine, arginine and lysine
58
chemical name of creatine
alpha-methyl guanidoacetic acid
59
Used to monitor renal function (an index of overall renal function)
creatinine
60
used to measure Fetal kidney maturity
creatinine
61
the most commonly used assay for Renal Blood Flow
creatinine
62
is easily removed by Dialysis
nope
63
is creatinine The production is constant
yes
64
Creatinine is formed from __ and __ in muscle and is
excreted into the plasma at a constant rate related to muscle mass.
creatine and creatine phosphate
65
relationship of GFR to plasma creatinine
inversely proportional
66
it is commonly
filtration function
plasma creatinine
67
increased creatine normal creatinine means
problem in muscle
68
increased in both creatinine and creatine means
problem in kidney
69
Creatinase Method, uses what enzymes?
creatininase
creatinase
sarcosine oxidase
peroxidase
70
Creatinase Method is available on what analyzer
Available on Ektachem analyzer
71
in creatinase coupled enzymatic Method uses what enzymes
creatinine aminohydrolase, creatinine kinase,
pyruvate kinase, and lactate dehydrogenase
72
in Creatinine Aminohydrolase Method what enzyme is used to hydrolyzed creatinine to creatin
creatinine aminohydrolase
73
creatinine aminohydrolase method measures
the disappearance of the reduced form nadh to NAD
74
the working solution of direct jaffe reaction method wherein the acid is added to a base is called as
alkaline sodium picrate solution
75
the alkaline sodium picrate solution in direct jaffe reaction method will result to what end color
red orange tautomer
76
interferences in DIRECT JAFFE REACTION METHODS
falsely increased
ascorbate, glucose, uric acid, ∝-ketoacids
77
a creatinine determination method wherein it didn't use enzyme but is still the most widely used method
direct jaffe reaction method
78
interferences in DIRECT JAFFE REACTION METHODS
falsely decreased
hemoglobin and bilirubin
79
purpose of adsorbents
remove interferences
80
adsorbents example of adsorbent used for direct jaffe reaction
Lloyd’s Reagent
fuller's earth reagent
81
Lloyd's reagent has __ as an adsorbent
sodium aluminum silicate
82
normal range of creatinine using serum for males
0.9 - 1.5 mg/dl
0.9 - 1.3 mg/dl in lec
83
fuller earth's reagent has __ as an adsorbent
aluminum magnesium silicate
84
normal range of creatinine using serum for females
0.7 - 1.4 mg/dl
0.6 - 1.1 mg/dl in lec
85
normal range of creatinine using urine for males
1000 - 2000 mg/24 hr
86
normal range of creatinine using urine for females
600 - 1500 mg/24 hr
87
CREATININE METHOD
colorimetric endpoint comments
(jaffe but endpoint)
simple and non specific
88
CREATININE METHOD
colorimetric kinetic comments
rapid and increased specificity
89
CREATININE METHOD
enzymatic comments
Measures ammonia
calorimetrically or with ION
selective electrode
90
what is the reaction time of jaffe method
endpoint
91
what is the reaction time of direct jaffe
kinetic
92
CLINICAL SIGNIFICANCE of creatinine determination
Aside from renal diseases, it is also elevated in myopathies like:
Muscular dystrophies
Familial periodic paralysis
Myasthenia gravis
Dermatomyositis
93
previous ref method of creatinine determination
direct jaffe method
94
ref method of creatinine method
idms - isotope dilution mass spectrophotometry
95
<10:1 B:C ratio means
LOW Protein Diet
Repeated Dialysis
Hepatic disease
96
High >20:1(normal creatinine)
B:C ratio means
Pre renal Azotemia, Dehydration, CHF
Catabolic states
GI hemorrhage
High Protein Diet
97
High >20:1(increased creatinine)
B:C ratio means
Post renal Azotemia, Urinary tract obstruction, Renal calculi, tumor
Renal disease
Renal Failure
98
nitrogen containing a-
biochemical abnormality that refers to
an increase in BUN and creatinine
levels which is largely related to decrease glomerular filtration
AZOTEMIA
99
defined as the increased in urea and
creatinine (azotemia) with accompanying clinical signs and symptoms of renal failure
UREMIA
100
signs and symptoms of renal failure seen in uremia
❑Metabolic acidosis due to failure of the kidneys to eliminate acidic products of metabolism
❑Hyperkalemia due to failure of potassium
excretion
❑Generalized edema due to water retention
❑(+) Burr cells
❑Anemia, Uremic frost (dry skin), foul breath and sweat (urine like)
101
conditions in which circulation of blood through the kidneys is less efficient than usual.
means lower perfusion
Pre-renal causes
102
Pre-renal causes
Hemorrhage (blood loss)
Cardiac decompression
Increased protein catabolism
Heatstroke (Dehydration)
Burns (Fluid loss)
103
characterized by the presence of lesions
on the parenchyma itself (tubular injury).
Renal causes
104
Renal causes
Chronic nephritis
Acute glomerulonephritis (AGN)
Polycystic kidney
Nephroschlerosis
Tubular necrosis (colorless urine)
105
due to the obstruction in
the-urinary-tract
Post-renal causes
106
Post-renal causes
Stones
Prostatic enlargement
Tumors
107
___ is the major end product of purine metabolism (Adenine and Guanine)
Uric acid
108
Uric acid is formed in the liver and intestinal mucosa from xanthine by the action of ___.
xanthine oxidase
109
BLOOD URIC ACID (BUA) Derived from
catabolism of ingested nucleoproteins, endogenous nucleoproteins
and direct transformation of endogenous purine nucleotides
110
Normally, ____% of the filtered UA is reabsorbed
89
111
is uric acid It is relatively insoluble?
yep
112
uric acid
When it accumulates, it may be deposited in the joints called as
tophi
113
Uric acid accumulates in the genitourinary tracts as ___
uric acid stones.
114
type of reaction of direct redox method
colorimetric
115
Uric acid is oxidized to allantoin and C02 by phosphotungstic
acid reagent (protein
precipitant and color reagent in alkaline solution).
In the process , phosphotungstic acid is
reduced to tungsten blue
DIRECT REDOX METHODS (COLORIMETRIC)
116
the acid used in direct redox method
phosphotungstic acid
117
in direct redox method
what is the end product of uric acid and phosphotungstic acid
allantoin and CO2
118
what is the color of the phosphotungstic acid once reduced under the direct redox method
tungsten blue
119
aside from the direct colorimetric reaction for uric acid which is the redox method, we as well have enzymatic method which is known as the ___
BLAUNCH and KOCK or URICASE METHOD
120
what is the reaction type of uricase method
end point
121
ENZYMATIC METHOD (BLAUNCH and KOCK or URICASE METHOD
is based on what type of spectrophotometry
Differential or Absorption Spectrophotometry
122
Uric acid is destroyed by the action of uricase
to form carbon dioxide and allantoin.
ENZYMATIC METHOD (BLAUNCH and KOCK or URICASE METHOD)
123
enzyme used in the enzymatic determination of uric acid
uricase
124
peak absorbance of uric acid
290-293 nm
125
Most commonly used method for uric acid determination employed by coupled enzymatic- Peroxidase
BLAUNCH and KOCK or URICASE METHOD
126
interferences of uricase method
protein
hemoglobin
xanthine
127
interferences in coupled enzymatic uricase-peroxidase method
bilirubin and ascorbic acid
128
what is the indicator used in coupled enzymatic method
4-aminophenazone - red color product
129
how to counter interferences of ascorbic acid and hgb in coupled enzymatid method of uri acid
use potassium ferricyanide and ascorbic oxidase
130
Uric acid is stable for several days (____) at room 'temperature and longer if refrigerated
3
131
uric acid
Addition of ___ increases its stability
to bacterial destruction
thymol
132
Any of the common anticoagulants, can be used except for ____ which forms potassium
phosphotungstate promoting turbidity
uric acid topic
potassium oxalate
133
Purine like foods like ___ and others may affect uric acid assay
legumes, visceral organs
134
Uric acid may be measured in ___.
heparinized plasma, serum, or urine
135
Serum should be removed from cells as quickly as possible to prevent ____ by intracellular contents.
uric acid
dilution
136
uric acd
Diet may affect uric acid concentration overall, but a recent meal has no significant effect and a fasting specimen is unnecessary.
fasting is not required but preferred
t or f
true
137
Gross lipemia should be avoided. High bilirubin concentration may falsely ____ results obtained by peroxidase methods. Significant hemolysis, with concomitant glutathione release, may result in ___ values.
decrease; low
138
Drugs such as ___ have been shown to increase values for uric acid
salicylates and thiazides
139
______ additives should not be used for specimens that will
be tested by a uricase method. Urine collections must be alkaline
Ethylenediaminetetraacetic acid (EDTA) or fluoride
140
ref method for uric acid
IDMS
141
Oldest method for the determination of
Uric Acid
CARAWAY METHOD
142
CARAWAY METHOD
Uses ___ as color stabilizer
NaCN - sodium cyanide
143
CARAWAY METHOD
Uses ___ as color stabilizer
sodium cyanide
144
a defect in uric acid metabolism which causes an excess of the acid and
salts to accumulate in the bloodstream and joints.
gout
145
increases uric acid in the bloodstream because alcohol inhibits its excretion
Chronic alcoholism
146
due to increased turnover of
nucleoproteins
Leukemia and other malignant conditions
147
Uric acid levels are elevated in decreased renal functions either due to over
production of uric acid or decreased rate of excretion
true or false
true
148
Fatal poisoning with chloroform and methanol, excessive exposure to X-rays and
radioactive radiators, due to excessive cell breakdown and nucleic acid catabolism can increase uric acid
true or false
true
149
(inborn error of purine metabolism) – HGPRT
deficiency
Lesch-Nyhan Syndrome
Hypoxanthine-guanine phosphoribosyltransferas
150
Hypouricemia related to kidney
decrease reabsorption of uric acid
151
Hyperuricemia
GSDs – Von Gierke’s
disease
Lactic acidosis
Toxemia of pregnancy
152
Hypouricemia
Fanconi’s syndrome
Wilson’s disease
Hodgkin’s disease
153
ADH
peptide hormone secreted by the __
posterior pituitary
154
response to increased blood osmolality
ADH
155
released when blood volume decreases by more than 5%–10%`
ADH
156
ADH is also known as
vasopressin
157
stimulates water reabsorption
ADH/ Antidiuretic
158
Water diffuses passively from the lumen of the tubules → resulting in
more concentrated urine and decreased plasma osmolality
ADH
159
Aldosterone
produced by the __
adrenal cortex
160
Aldosterone
produced by the adrenal cortex → influence of the _____ mechanism
renin-angiotensin
161
Triggered by decreased blood flow or blood pressure in the afferent
renal arteriole
Aldosterone
162
Decreased plasma sodium
Aldosterone
163
stimulates sodium reabsorption in the distal tubules and potassium and hydrogen ion secretion
Aldosterone
164
THREE MAJOR GROUPS OF KIDNEY FUNCTION
TESTS
Test measuring glomerular filtration rate (GFR)
Test measuring renal blood flow
Test measuring tubular function
165
The __ is the volume of plasma filtered (V) by the glomerulus per unit of time (t)
GFR
166
a gfr that Does not require the collection of timed 24 urine specimen
ESTIMATED GLOMERULAR FILTRATION RATE
167
inhibitor of cysteine proteinase
cystatin c
168
filtered peptide is completely reabsorbed by the proximal tubule → destroyed rather than
reentering the circulation
CYSTATIN C
169
component of the major histocompatibility complex class I molecule
β-2-Microglobulin
170
production is increased in multiple myeloma and lymphoma
β-2-Microglobulin
171
Common cause of dialysis-associated amyloidosis
β-2-Microglobulin
172
functions as prostaglandin D synthase
Β TRACE PROTEIN
173
plasma level is increased in patients with renal disease because of reduced filtration in the presence of constant
production
Β TRACE PROTEIN
174
▪ filtered at the glomerulus freely and is not reabsorbed
Tryptophan Glycoconjugate
175
___ freely passes the glomeruli but is neither secreted nor reabsorbed by the nephric tubules.
inulin
176
Considered to be the most accurate measure of GFR
INULIN CLEARANCE TESTS
177
reference method of all the clearance test
INULIN CLEARANCE TESTS
178
___ is freely filtered by the glomeruli but variably reabsorbed in the tubules depending upon the
transit time (rate of urine flow along the course of nephric tubules) of urea filtrate
Urea
179
A more reliable method than Urine SG, Affected only by the numbers of
solutes present in the urine and serum
OSMOLALITY
180
major contributor of Urine osmolality → ___
Urea
181
major contributor of Urine Serum osmolality → __
Sodium and Chloride
182
183
Sample fr osmolality
Serum or Urine (24 hr)
184
Reference value OSMOLALITY
S osm= 275-295 mosm/Kg
U osm= 300-900 mosm/Kg
Normal Ratio: 1:1 -3:1
185
Determined by measuring the colligative property of the sample.
autoanalyzer
DIRECT METHOD OF OSMOLALITY
186
Parameters of DIRECT METHOD OF OSMOLALITY
FREEZING POINT, VAPOR PRESSURE,
OSMOTIC PRESSURE AND BOILING POINT
187
INCREASE IN OSMOLALITY: ___
Increase in osmotic pressure
and boiling point
188
Most commonly used Method in OSMOLALITY
Freezing Point osmometry
189
