U4 LEC: NPNs: URIC ACID (PT. 1) Flashcards
(102 cards)
1
Q
Product of catabolism of purine bases
A
Uric Acid
catabolism also happens in the liver
2
Q
Purine bases
A
Adenine, Guanine
3
Q
Readily filtered by?
A
glomerulus
4
Q
Uric acid undergoes?
A
reabsorption and secretion
5
Q
____% reabsorbed in the _________
A
98-100, proximal convoluted tubules
6
Q
_____% excreted in the _________
A
<1%, distal tubules
7
Q
Renal excretion
A
70%
8
Q
GI excretion
A
30%
9
Q
Relatively insoluble in plasma as _______ at _______
A
monosodium urate, pH 7.0
10
Q
At what concentrations does plasma become saturated and may form urate crystals in the tissues?
A
> 6.8 mg/dL
11
Q
At what pH does uric acid crystals form?
A
< 5.75 (acidic urine)
12
Q
Where does monosodium urate crystals deposit into?
A
tissues and joints
13
Q
Where do you see uric acid crystals in pH <5.75?
A
acidic urine
14
Q
The accumulation of high concentrations of crystals is called?
A
Tophi
15
Q
The inflammation after accumulation in joints and tissues is called?
A
gouty arthritis
16
Q
Gout has _____ uric acid, saturated plasma
A
increased
17
Q
Inflammation can also lead to?
A
edema (swelling / pamamanas due to liquid)
18
Q
Method of reliving Gouty Arthritis
A
use 50-100mL syringe to aspirate synovial fluid from the knee
19
Q
Clinical applications of Uric Acid
A
- confirm diagnosis and monitor treatment of gout
- assess and prevent uric acid nephropathy during chemotherapeutic management
- assess inherited disorders of purine metabolism
- detect kidney dysfunction
- assist in the diagnosis of renal calculi
20
Q
Clinical Application
Confirm diagnosis and monitor treatment of?
A
gout
21
Q
This refers to uric acid in blood.
A
Monosodium urate
22
Q
Clinical Application
Assess and prevent uric acid nephropathy during?
A
chemotherapeutic management
23
Q
T/F: In chemotherapy, there is increase in the uric acid, and decreased WBC.
A
True
Cell lysis > kakalat nucleic acids > high purines
24
Q
Clinical Application
Assess inherited disorders of?
A
purine metabolism
25
Clinical Application
Detect?
kidney dysfunction
98% is reabsorbed dapat by the kidneys so UA can be a marker
26
Clinical Application
Assist in the diagnosis of?
renal calculi
27
T/F: Uric acid can form renal calculis.
True
28
Most common kidney stone
Calcium Oxalate (CaOx)
29
Calcium Oxalate can be seen in conditions of?
- Chronic UTI
- Parahyperthyroidism (production of excessive calcium)
30
Hyperuricemia
> 6.0 mg/dL
31
Gout is present in males between?
30 to 50 yrs of age
32
Gout is present in females after?
menopausal
33
Normal value of UA
until 7.2
pero dapat daw di ka na umabot dito !
34
Food rich in purines
- street foods (laman loob; liver, isaw)
- beer
- red meat
- dark meat of fish
- monggo
35
Pain and inflammation of joints are caused by?
precipitation of sodium urates
36
Hyperuricemia is seen in what percentage of patients?
25% to 30%
result of overproduction of uric acid
37
T/F: You can be hyperuricemic and not have gout.
True
38
Hyperuricemia can cause?
formation of renal calculi
39
Hyperuricemia can also cause?
increased nuclear breakdown
40
Increased nuclear breakdown
seen in patients undergoing chemotherapy for?
- leukemia
- lymphoma
- multiple myeloma
- polycythemia
41
Increased nuclear breakdown
UA monitoring is done to avoid?
nephrotoxicity and renal calculi
42
Increased nuclear breakdown
Treatment
Allopurinol
43
Increased nuclear breakdown
Allopurinol inhibits or attacks what enzyme?
Xanthine oxidase
44
Increased nuclear breakdown
Xanthine Oxidase converts _______ to UA
Hypoxanthine and Xanthine
45
Increased nuclear breakdown
can also cause?
- Hemolytic/megaloblastic anemia
- Purine-rich diet
46
UA can also be used to detect?
kidney diseases (impaired filtration and secretion)
47
T/F: With impaired filtration and secretion, Uric Acid may increase in the blood.
True
48
T/F: Uric Acid is not a good indicator for renal function.
True
if problema is nasa distal = small amt lang ang nasa urine
49
This syndrome is an X-linked genetic disorder.
Lesch-Nyhan Syndrome
50
Lesch-Nyhan Syndrome
only seen in?
males (commonly in male children)
51
Lesch-Nyhan Syndrome
Absolute/complete deficiency of?
Hypoxanthine-Guanine Phosphoribosyltransferase (HGPT)
52
Lesch-Nyhan Syndrome
This enzyme is responsible for utilization of purine bases in the nucleotide salvage pathway.
Hypoxanthine-Guanine Phosphoribosyltransferase (HGPT)
53
Lesch-Nyhan Syndrome
Lack of HGPT prevents reutilization of purine bases in the?
nucleotide salvage pathway
54
Lesch-Nyhan Syndrome
Consequentially results in?
increased UA in plasma and urine
55
Lesch-Nyhan Syndrome
Characteristics
- deformities
- neurologic symptoms
- mental retardation
- self mutilation
56
Lesch-Nyhan Syndrome
____ purine synthesis, _______ degradation product
increasing
57
Disease Correlation
- mutations on Phosphoribosyl synthetase
- Toxemia of pregnancy (preeclampsia)
- Lactic acidosis
58
Disease Correlation
Glycogen storage disorder
Type I (Von Gierke)
gluconeogenesis (nucleic acids to energy)
59
Disease Correlation
Atrophy (tissues will eat theirselves)
Increased tissue catabolism or starvation
60
Causes of Hyperuricemia
Decreased UA excretion
- Preeclampsia
- Lactic acidosis
61
Causes of Hypouricemia
Secondary to?
severe liver disease
62
Causes of Hypouricemia
Defective tubular reabsorption (tuloy tuloy ineexcrete, nasa ihi and di nabalik sa blood)
Fanconi Syndrome
63
Causes of Hypouricemia
Chemotherapy with?
- 6-mercatopurine
- azathiopurine
64
Causes of Hypouricemia
6-mercatopurine and azathiopurine inhibits?
de novo purine synthesis
65
Causes of Hypouricemia
______ of Allopurinol
Overproduction
66
Reference method for Uric Acid
Isotope dilution mass spectrometry (IDMS)
67
Direct REDOX Method is called?
Caraway / Henry's Method
68
Caraway / Henry's Method
Utilizes?
Phosphotungstic acid
69
Caraway / Henry's Method
Will produce?
Tungsten blue and allantoin
70
Caraway / Henry's Method
End product of purine metabolism in lower forms
Allantoin
(UA to Allantoin)
71
Caraway / Henry's Method
________ of Uric Acid in PFF
Oxidation
72
Caraway / Henry's Method
__________ of Phosphotungstic Acid
Reduction
73
Caraway / Henry's Method
False increaase
- turbidity
- aspirin and metabolite
- acetaminophen
- caffeine
- theophylline
74
Iron Reduction Method
Ferric iron will become?
ferrous iron
75
Most common method for Uric Acid
Enzymatic Method
76
Enzymatic Method
Utilizes what enzyme?
Uricase
77
Uricase Method is also known as?
Blauch and Koch
78
Uricase Method
Conversion of?
UA to Allantoin
79
T/F: With the help of Uricase, the amount of UA is proprtional to converted amount of Allantoin
True
80
Uricase Method
Measurement at?
290-293nm
81
Uricase Method
more specific but proteins may cause?
high background absorbance
82
Uricase Method
Negative interference due to?
- Hemoglobin
- Xanthine
83
This refers to a colorimetric method.
Coupled Enzymatic Method
84
Coupled Enzymatic Method
After conversion to Allantoin, utilizes?
H2O2 (Peroxide) and indicator dye to produce colored compound
85
Coupled Enzymatic Method
These may destroy peroxide (wala masyado sasama sa colored compound), may lead to false decrease
- Bilirubin
- Ascorbic acid
86
Coupled Enzymatic Method
Remedy for Peroxide
Addition of:
- Potassium ferricyanide
- Ascorbate oxidase
87
IDMS
Detection of?
characteristic fragments after ionization
88
IDMS
Quantification using?
isotopically labeled compound
89
Specimen Requirements
- heparinized plasma
- serum
- urine
90
Specimen Requirements
may affect UA concentration
Diet
91
T/F: Recent intake of food will not have a significant effect, hence, it is a non fasting test.
True
92
Specimen Requirements
This should be avoided
Gross lipemia (turbidity causes interference)
93
Specimen Requirements
May result to low values
Hemolysis with concomitant glutathione release
94
Specimen Requirements
May increase UA values
- Salicylates
- Thiazides
95
Specimen Requirements
Serum samples may be refrigerated for?
3 to 5 days
96
Specimen Requirements
Anticoagulants that should not be used
- EDTA
- Sodium Fluoride
inhibits Uricase
97
Specimen Requirements
Urine specimen
must be alkalinzed to pH 8(add chemicals)
98
Conversion Factor
0.06
99
Reference Values
Male
3.5-7.2 mg/dL (0.21-0.43 mmol/L)
100
Reference Values
Female
2.6-6.0 mg/dL (0.16-0.36 mmol/L)
101
Reference Values
Child
2.0-5.5 mg/dL (0.12-0.33 mmol/L)
102
Reference Values
Adult, Urine 24 h
250-750 mg/d (1.5-4.4 mmol/d)
