Bilirubin and NPN Measurement Flashcards
(229 cards)
1
Q
End product of hemoglobin metabolism
A
BILIRUBIN
2
Q
Principal pigment in bile
A
BILIRUBIN
3
Q
What are the sources of bilirubin
A
- Heme
- Myoglobin, cytochrome, peroxidases/catalase
4
Q
How many % of bilirubin derived from heme
A
85%
5
Q
How many % of bilirubin derived from Myoglobin, cytochrome, peroxidases/catalase
A
15% (remaining)
6
Q
Fill in the blanks:
Senescent RBCs (old RBCs) are destroyed in the _____ which cause the liberation or release of _______.
A
spleen; hemoglobin
7
Q
What are the 3 components of hemoglobin
A
iron, heme, and globin
8
Q
What happens to the globins in the circulation
A
Globins are degraded and the amino acids are recycled by the body
9
Q
In the circulation:
Iron is bound to what transport protein?
A
transferrin
10
Q
What happens to the iron in the circulation
A
Iron is bound to transferrin (transport protein), which will be delivered to the liver and other organs.
11
Q
Component of hemoglobin wherein the bilirubin is derived
A
Heme
12
Q
In the circulation:
heme is degraded to ______ by the action of _______
A
biliverdin; heme oxygenase
13
Q
Biliverdin is reduced to ______ by the enzyme _______
A
Bilirubin 1; biliverdin reductase.
14
Q
Bilirubin 1 will be transported by the ______ from the circulation to the _____ (hepatic cycle), where it will be released and picked up by the transport protein called as _______.
A
albumin
liver
ligandins
15
Q
The Bilirubin 1 in the liver will be conjugated/esterified with ______ to form ______ and to ________ by the action of the enzyme ________
A
glucoronic acid;
bilirubin monoglucoronide;
bilirubin diglucuronide/B2;
uridine diphosphate glucoronyl/glucoronosyl transferase (UDPGT)
16
Q
Once conjugated/Bilirubin 2 is formed, it will now be transported to the _____ where it is reduced to form ______, ________, ______ by ________
A
intestine
mesobilirubin, mesobilirubinogen, urobilinogen intestinal bacteria
17
Q
colorless byproduct of reduction of bilirubin
A
Urobilinogen
18
Q
2 fates of urobilinogen
A
80% converted to stercobilin
20% reabsorbed to the circulation and filtered by the kidneys in the form of urobilin
19
Q
stercobilin is excreted in what
A
stool
20
Q
urobilin is excreted in what
A
urine
21
Q
What are the 2 forms of bilirubin
A
bilirubin 1 & bilirubin 2
22
Q
Other names for Bilirubin 1
A
Unconjugated Bilirubin
Water Insoluble
Non-polar Bilirubin (has 2 propionic acids present)
Indirect bilirubin
Hemobilirubin
Slow reacting
Prehepatic bilirubin
23
Q
Other names for Bilirubin 2
A
Conjugated Bilirubin
Water soluble
Polar Bilirubin (the 2 propionic acids are already conjugated/esterified)
Direct bilirubin
Cholebilirubin
One-minute/Prompt Bilirubin
Post-hepatic/ Hepatic/ Obstructive/ Regurgitative Bilirubin
24
Q
bilirubin found in the circulation/blood
A
Bilirubin 1
25
bilirubin found in the liver and intestine
bilirubin 2
26
form of bilirubin that can be directly measured by the reagent
bilirubin 2
27
what is the reference value for unconjugated Bilirubin:
0.2 – 0.8 mg/dL
28
what is the reference value for conjugated Bilirubin:
0.0 – 0.2 mg/dL
29
conjugated bilirubin is synthesized in the liver that is why it should not be present in the circulation. however, there are cases in which there is a very small amount of it in the circulation, why?
very small amount of it may be present due to minor leakage from the hepatocytes (0.2 mg/dL)
30
what is the reference value for total Bilirubin:
0.2 – 1.0 mg/dL
31
What do you mean by total bilirubin
conjugated and unconjugated bilirubin combined
32
Conjugated bilirubin (B2) tightly bound to albumin
Delta Bilirubin
33
Delta Bilirubin is formed due to:
prolonged elevation of conjugated bilirubin
34
T/F:
delta bilirubin has shorter half life compared to other forms of bilirubin
F; LONGER half life
35
Helps in monitoring the decline of serum bilirubin following cholecystectomy
delta bilirubin
36
refers to the surgical removal of gallbladder
cholecystectomy
37
delta bilirubin reacts with what reagent
diazo reagent
38
reagent used to measure the normal forms of bilirubin
diazo reagent
39
Reference value of delta bilirubin
<0.2 mg/dL
40
what is the formula of delta bilirubin
Delta bilirubin=TB-(DB+IB)
41
The formula in delta bilirubin can be used all of the time except for ______
neonate patients (≤14 days old)
42
Sample used in bilirubin measurement
serum
43
T/F: In Bilirubin measurement, the sample must be stored away from light immediately
T
44
if not protected from light, bilirubin levels may decreased to:
30 - 50%/hr
45
If sample is prepared and stored properly:
Room temperature: ______
Refrigerator (4 ̊C): ______
Freezer (-20 ̊C): _______
2 days
1 week
indefinite
46
T/F:
Fasting sample is required in bilirubin measurement
F; Fasting sample is preferred but not required
47
T/F Recent intake of food may cause lipemia
T
48
What are the Interferences in bilirubin measurement
lipemia and hemolysis
49
In bilirubin measurement, lipemia (increases, decreases) bilirubin conc.
increases
50
In bilirubin measurement, hemolysis (increases, decreases) reaction of bilirubin with diazo reagent causing a (decreased, increased) bilirubin
decreases; decreased
51
Principle used in bilirubin measurement
Van den Berg Reaction
52
diazotization of bilirubin to form azobilirubin
Van den Berg Reaction
53
Van den Berg Reaction is the diazotization of bilirubin to form _______
azobilirubin
54
T/F;
55
T/F;
Van den Berg Reaction only measure conjugated bilirubin and total bilirubin
T
56
What must be added in order to measure unconjugated bilirubin in bilirubin measurement
accelerants/accelerator
57
What are the two methods used in bilirubin measurement
Evelyn and Malloy Method
Jendrassik and Grof Method
58
Coupling Accelerator used in Evelyn and Malloy method
methanol
59
T/F: Methanol is added to measure unconjugated bilirubin/B1 so that total bilirubin can be measured
T
60
What are the 3 diazo reagents used in evelyn and malloy method
Diazo A
Diazo B
Diazo Blank
61
Diazo A contains
0.1% sulfanilic acid, hydrochloric acid (HCl)
62
Diazo B contains
0.5% Sodium nitrite
63
Diazo blank contains
1.5% HCl
64
Final Reaction in Evelyn and Malloy Method
pink to purple azobilirubin (measured @ 560 nm)
65
Popular technique for discreet analyzers
Jendrassik-Grof Method
66
Most commonly used method because it is more sensitive than Evelyn and Malloy Method
Jendrassik-Grof Method
67
Main reagent used in Jendrassik-Grof method
Diazo reagent
68
Accelerator used in Jendrassik-Grof method
Caffeine Sodium Benzoate
69
Buffer used in Jendrassik-Grof method
Sodium acetate
70
terminates the accelerator and destroys excess diazo reagent
Ascorbic acid
71
provides alkaline pH after addition of ascorbic acid
Alkaline tartrate solution:
72
Final reaction in Jendrassik-Grof Method
blue azobilirubin (measured at 600 nm)
73
most common cause of jaundice
Cholelithiasis (gallstones)
74
characterized by yellow discoloration of the skin, sclera, and mucus membranes.
Hyperbilirubinemia
75
Type of jaundice that is not visible to the naked eye
Overt Jaundice:
76
reference value for Overt Jaundice
1.0 – 1.5 mg/dL
77
high levels of bilirubin but no abnormal yellowish discoloration
overt jaundice
78
RV for visible jaundice
3.0 – 5.0 mg/dL
79
RV for visible jaundice
3.0 – 5.0 mg/dL
80
more commonly termed for serum or plasma with yellow discoloration due to hyperbilirubinemia.
Icterus
81
RV for icterus
>25 mg/dL
82
T/F Nowadays, icterus and jaundice can be used interchangeably
F
83
What are the 3 classification of jaundice
pre-hepatic Jaundice/hepatic jaundice/post-hepatic Jaundice
84
What is the cause of pre-hepatic jaundice
Too much RBC destruction
85
Pre-hepatic jaundice:
Bilirubin assay?
Elevated Indirect Bilirubin
86
Cause of hepatic jaundice
Hepatocyte injury caused by viruses, alcohol, and parasites
87
Hepatic jaundice:
Biirubin assay?
Elevated Direct and Indirect Bilirubin
88
Cause of post hepatic jaundice
Failure of bile to flow in the intestine (Impaired bilirubin excretion)
89
Post-hepatic jaundice:
bilirubin assay?
Elevated Direct Bilirubin
90
most abundant NPN
Urea
91
40% of the total NPN
urea
92
major end product of protein and amino acid catabolism
UREA NITROGEN (BLOOD) BUN
93
Approximately 80% of the nitrogen excreted
UREA NITROGEN (BLOOD) BUN
94
First metabolite to increase in kidney disease
UREA NITROGEN (BLOOD) BUN
95
BUN are excreted by the kidneys but _____ of them are reabsorbed
40%
96
Reference value for UREA NITROGEN (BLOOD) BUN
8-23 mg/dL
97
What is the Normal Bun:Creatinine Ratio
10-20:1
98
What are the sample used in Urea Nitrogen Methodologies
serum, plasma, urine
99
Urea Nitrogen Methodologies:
If the sample is plasma, ____ and _____ should not be used
fluoride and citrate
100
Why is fluoride and citrate not used if the sample is plasma in urea nitrogen
these inhibits urease
101
reagent used in the enzymatic method of BUN measurement
Urease
102
T/F:
In Urea Nitrogen methodologies, refrigerate sample if delay in testing is expected
T
103
Why the sample needs to be refrigerated
Because urea may be decomposed by urease producing bacteria
104
Assays for urea were based on measurement of ______
nitrogen
105
what are the 3 methods in Urea Nitrogen
1. chemical method
2. enzymatic method
3. Isotope Dilution Mass Spectrometry
106
Urea Nitrogen Methodologies:
Chemical method is also known as
Diacetyl Monoxime (DAM) Method
107
Urea Nitrogen Methodologies:
what is the indicator dye used in the chemical method
Diacetyl Monoxime (DAM)
108
Urea Nitrogen Methodologies:
T/F: Chemical method is a specific method
F; not specific
109
Reference method in Urea Nitrogen Methodologies
Isotope Dilution Mass Spectrometry
110
What are the 2 enzymatic methods in urea nitrogen methodologies
Urease Method
Urease-Glutamate dehydrogenase (GLD) method
111
it involves the hydrolysis of urea to form ammonia by the enzyme urease.
Urease Method
112
urease is prepared from ___
jack beans
113
Urease method:
The synthesized ammonia may be subjected to ________ to form a chromogenic product which is _____
Berthelot’s reaction
indophenol blue
114
Urease method:
T/F: Ammonia and CO2 can be measured by different methods to calculate the concentration of urea in the sample. But CO2 is more commonly used
F; ammonia is more commonly used
115
known as Coupled Urease Method
Urease-Glutamate dehydrogenase (GLD) method
116
why is Urease-Glutamate dehydrogenase (GLD) method known as coupled urease method?
it uses 2 enzymes (urease & glutamate)
117
aka UV Enzymatic Method
Urease-Glutamate dehydrogenase (GLD) method
118
T/F: BUN and urea are exactly the same.
F; BUN and urea are NOT exactly the same.
119
Atomic mass of Nitrogen
14 g/mol
120
Molecular mass of urea
60 g/mol
121
Urea is equivalent to how many Nitrogen atoms
2 Nitrogen atoms (46.6% of the total weight of urea)
122
How many g/mol of BUN is there per 60 g/mol of UREA
28 g/mol of BUN
123
1 mol of urea is equivalent to how many g/mol of nitrogen?
28 g/mol Nitrogen
124
For every BUN/Nitrogen, there is ____ g/mol of urea
0.4666 g/mol of urea
125
Formula for urea
Urea=BUN x 2.14
126
Creatinine is synthesized primarily by the liver from ______, _________, and _______
arginine, glycine and methionine
127
Synthesized primarily by the liver from arginine, glycine and methionine
Creatinine
128
Measure the completeness of 24 hour urine collection (urine creatinine)
CREATININE
129
In 24 hr urine collection, the urine creatinine should be _____
>0.8 g/day
130
In 24 hr urine collection, if the urine creatinine is <0.8 g/day, it indicates what?
collection is incomplete
131
Index of overall renal function
CREATININE
132
why is creatinine considered as the index of overall renal function
Because the excretion is very stable
133
Creatinine:
reference value for male:
0.9-1.3 mg/dL
134
Creatinine:
reference value for female:
0.6-1.1 mg/dL
135
Creatinine:
reference value for child:
0.3-0.7 mg/dL
136
What are the sample used in creatinine methodologies
serum, plasma, urine
137
What are the interferences in creatinine methodologies
hemolysis, ictericia, lipemia
138
What are the 4 methods in creatinine methodologies
1. Direct Jaffe Method (Chemical Method)
2. Kinetic Jaffe Method
3. Enzymatic Method
4. Isotope Dilution Mass Spectrometry (IDMS)
139
composition of jaffe's reagent
Saturated picric acid
10% NaOH
140
T/F: Jaffe reagent is stable
False; fairly unstable
141
What happens when jaffe's reagents are mixed together
when mixed together, they become unstable; may form picramic acid and methyl guanidine (forms orange color)
142
What are the interferences in Direct Jaffe Method, FALSE INCREASE?
Creatinine-like analytes: Uric acid, ascorbic acid, glucose, α-keto acids
Medications: cephalosporins, dopamine, lidocaine
143
What are the interferences in Direct Jaffe Method, FALSE DECREASE?
bilirubin, hemoglobin
144
What are the 2 methods under Direct Jaffe Method
Folin Wu Method
Lloyd or Fuller’s Earth Method
145
A sensitive but not specific method
Folin Wu Method
146
What are the interferences in folin wu method
Acetoacetate
Acetone
Ascorbate
Glucose
Pyruvate
147
T/F: the interferences in Folin Wu method are creatinine like substances/analytes
T
148
added to remove interferences
Adsorbents
149
A sensitive and specific method
Lloyd or Fuller’s Earth Method
150
Adsorbent used in Lloyd or Fuller’s Earth Method
Lloyd's reagent
Fuller’s Earth reagent
151
Lloyd’s reagent contains:
Sodium aluminum silicate
152
Fuller’s Earth Reagent contains
Aluminum magnesium silicate
153
What are the disadvantages of Lloyd or Fuller’s Earth Method
Time consuming
Not employed to automated analyzers
154
Requires automated analyzers for precision
Kinetic Jaffe Method
155
Fill in the blanks (Principle of Kinetic Jaffe Method)
Serum is mixed with _________ and the rate of change in absorbance is measured between _______ (1 min & 2 mins marked difference)
alkaline picrate solution;
two points
156
composition of alkaline picrate solution
picric acid + 10% NaOH or Jaffe reagent
157
Interferences in Kinetic Jaffe Method
False increased: α-ketoglutarate, cephalosporins
158
What is the Routinely used method in creatinine methodologies
Enzymatic Method
159
Used to eliminate the non-specificity of Jaffe reagent
Enzymatic Method
160
More specific than Direct and Kinetic Jaffe Method
Enzymatic Method
161
What are the two methods under Enzymatic method
1. Creatinine Aminohydrolase-CK Method
2. Creatinase-Hydrogen Peroxide Method
162
Why is Creatinine Aminohydrolase-CK Method not widely used?
because it requires a large volume of pre-incubated sample
163
Has potential to replace Jaffe method (more specific)
Creatinase-Hydrogen Peroxide Method
164
Without interference from acetoacetate and cephalosporins
Creatinase-Hydrogen Peroxide Method
165
Creatinase is also known as:
creatinine aminohydrolase
166
elevated concentration of NPN in the blood
azotemia
167
what are the two noted NPNs in Azotemia?
urea and creatinine
168
presence of elevated plasma urea accompanied by renal failure
Uremia/Uremic syndrome
169
Causes of urea plasma elevations are:
Prerenal
Renal
and postrenal
170
Anything that produces a decrease in functional blood volume and High protein diet or increased catabolism are the cause of this azotemia
Pre-renal Azotemia
171
Anything that produces a decrease in functional blood volume, include:
Congestive heart failure
Shock
Hemorrhage
Dehydration
172
High protein diet or increased catabolism during:
Fever, major illness, stress
173
State the process involving pre-renal azotemia
Reduced Renal Blood Flow (most common)
↓
Less blood delivered to the kidney
↓
Less urea is filtered
174
Also known as True Renal Disease
Renal Azotemia
175
What are the causes of Renal Azotemia
Acute/chronic renal disease
Glomerulonephritis
Tubular necrosis
176
Renal Azotemia (LAB Results)
BUN (increased, decreased) to ______ mg/dL
increased; >100 mg/dL
177
Renal Azotemia (LAB Results)
Creatinine (increased, decreased) to ______ mg/dL
increased; 20 mg/dL
178
Renal Azotemia (LAB Results)
BUA (increased, decreased) to ______ mg/dL
increased; 12 mg/dL
179
What is the hormone involved in Electrolyte imbalance
aldosterone
180
Anemia is seen in the lab result of thos type of azotemia
Renal Azotemia
181
Complications in Renal Azotemia
Coma
Neuropsychiatric changes
182
State the process involving renal azotemia
Damaged Kidneys
↓
Poor Excretion
↓
Increased Urea
183
Usually the result of Urinary Tract Obstruction
Post Renal Azotemia
184
In Post Renal Azotemia, urea level is higher than creatinine due to:
back-diffusion of urea into the circulation.
185
Causes of Post Renal Azotemia
nephrolithiasis, renal calculi, cancer/tumors of genitourinary tract, severe infection
186
What is nephrolithiasis
kidney stones
187
Chemical name of uric acid
2,6,8-trihydroxypurine
188
It is the major product of purine (adenine and guanine) catabolism.
URIC ACID
189
Uric acid is the major product of ?
purine (adenine and guanine) catabolism
190
It is the final breakdown of nucleic acids catabolism in humans.
Uric acid
191
what are the sources of nucleic acids in the body
Ingestion
Endogenous
Endogenous purine nucleotides
192
T/F: Nucleic acids found within the body breakdowns when cells are dead (apoptotic cells)
T
193
It is formed from xanthine by the action of xanthine oxidase in the liver and intestine.
Uric acid
194
Uric acid is formed from _____ by the action of ________ in the liver and intestine.
xanthine; xanthine oxidase
195
Uric acid is transported to kidney and filtered.
How many percent is filtered?
70%
196
How many % of uric acid are reabsorbed by the proximal convoluted tubules
98% (of the 70%)
197
Remaining 30% of uric acid will go to the ____ where they are degraded by the bacterial enzymes
GIT
198
Uric acid is present in plasma as:
monosodium urate
199
How many % of Uric acid is present in plasma as monosodium urate
95%
200
T/F:
At plasma pH, uric acid is relatively insoluble (may accumulate)
T
201
Uric acid:
RV for male:
3.5-7.2 mg/dL
202
Uric acid:
RV for female:
2.6-6.0 mg/dL
203
Uric acid:
RV for child:
2.0-5.5 mg/dL
204
At what concentration does plasma with uric acid is saturated.
>6.8 mg/dL
205
Saturated plasma may _____, forming ______ which can be deposited into the _____ causing _____.
Saturated plasma may precipitate, forming uric acid crystals which can be deposited into the tissues (joints) causing gout.
206
Uric acid crystal may also be formed in the urine if the urine filtrate is ____ (pH: ?)
acidic (pH <5.75)
207
Sample used in Uric Acid Methodologies
serum, heparinized plasma, urine
208
In UA Methodologies;
Serum may be stored for ______ (refrigerator)
3-5 days
209
In UA Methodologies;
Serum may be stored for ______ (refrigerator)
3-5 days
210
Urine sample in uric acid should have pH level of
8.0
211
T/F: Fasting is required because food intake affects uric acid conc.
F; Fasting is NOT required because food intake DOES NOT affect uric acid conc.
212
Interferences in uric acid:
False increased: ______, ______, _____
lipemia, salicylates, thiazides
213
Interferences in uric acid:
False decreased: ______, ______
high bilirubin, hemolysis
214
3 Methods in Uric acid methodologies
Chemical Methods
Enzymatic Methods
Isotope Dilution Mass Spectrometry – reference method
215
Also known as Caraway method
Chemical Method
216
Chemical Method is also known as ?
Caraway method
217
Principle in chemical method
Reduction-oxidation reaction
218
Sodium cyanide (NaCN) is USED for: ____, _____, _____, _____
Folin, Newton, Brown, Benedict
219
Sodium carbonate (NaCO3) is used for: _____, ____, ____
Caraway, Archibald, Henry
220
Also known as Uricase method
Enzymatic Method
221
T/F: In enzymatic method (Uric acid), EDTA/fluoride tube must be used
F; EDTA/fluoride tube must NOT be used
222
T/F: Enzymatic method (Uric acid) is a specific method
T
223
T/F: Enzymatic method (Uric acid) is a specific method
T
224
Principle used in enzymatic method (Uric acid)
Uric acid is oxidized to form allantoin by uricase enzyme.
225
Uric acid is oxidized to form_____ by ____ enzyme
allantoin; uricase
226
has a peak absorbance at 293 nm
Uric acid
227
not absorbed at 293 nm.
Allantoin
228
HYPERURICEMIA is seen in:
Gout
Increased nuclear metabolism
Chronic Renal Disease
Lesch-Nyhan Syndrome
Secondary to Glycogen Storage Disease (GSD)
Toxemia of pregnancy and lactic acidosis
Increased dietary intake
Ethanol consumption
229
HYPOURICEMIA is seen in:
Fanconi’s syndrome
Wilson’s disease
Hodgkin’s disease
Overtreatment with allopurinol
Chemotherapy (6-mercaptopurine, azathioprine)
Alzheimer’s disease
Parkinson’s disease
