NPN Flashcards
1
Q
Which is true regarding NPN?
A. Compounds arise from the catabolism of proteins and nucleic acids
B. Majority are excreted in the kidneys
C. The term nonprotein nitrogen (NPN) originated in the early days of biochemistry
D. A and B
A
D
2
Q
NPN of highest concentration in the blood and end product of protein catabolism state of hydration
A
Urea
3
Q
First metabolite to increase in kidney diseases and part of the B:C Ratio (normal B:C ratio is 10:1-20:1)
A
Urea
4
Q
increased BUN
a. poor nutrition
b. high fluid intake
c. azotemia
d. over hydration
e. pregnancy
f. severe liver disease
A
C
5
Q
decreased BUN:
a. stress
b. burns
c. high protein diet
d. dehydration
e. severe liver disease (hormones)
f. azotemia
A
E
6
Q
Clinical application of Urea A. Evaluation of renal function B. Assess hydration status C. Determine nitrogen balance D. Aid in the diagnosis of renal disease E. Verify adequacy of dialysis F. All of the above
A
F
7
Q
are used most frequently in clinical laboratories for Urea
A
Enzymatic method
8
Q
The most common method couples the urease reaction with ____________
A
glutamate dehydrogenase
9
Q
An increase in pH due to the production of ammonia color results in urase (6.8)
A
Yellow
10
Q
An increase in pH due to the production of ammonia color results in urase (pH 8.2)
A
bright pink
11
Q
End product of muscle metabolism derived from
A
creatinine
12
Q
Urea in PFF, the presence of buffer and heat-forming ammonium carbonate which is then reacted with _____ to form a ______
A
Nessler’s reagent, yellow dimercuric ammonium iodide
13
Q
The Oldest method in Urase
A
Micro-Kjeldahl Nessler
14
Q
Mixture of sulfuric acid and phosphoric acid
A
Kjeldahl process
15
Q
Coupled Urease
A
Glutamate Dehydrogenase Method
16
Q
Commonly and Routinely done. Urease is prepared from jack beans. Ammonia treating with Berthelot reagents.
A
Hydrolysis of Urea by Urease
17
Q
DIRECT MEASUREMENT OF UREA
A
Diacetyl Monoxime Method (DAM)
18
Q
Diacetyl Monoxime Method (DAM) produces what color
A
Yellow
19
Q
Principle of Diacetyl Monoxime Method
A
Faeron Reaction
20
Q
- _____ will inhibit urase, it should be avoided. 2._______ are added to enhance color development.
A
- Fluoride and Citrate
2. Thiosemicarbazide and ferric ions
21
Q
Urea nitrogen concentration expressed in
A
mg/dL
22
Q
Urea nitrogen concentration converted to urea concentration in ____
A
mmol/L
23
Q
Specimen used in Urea
A
plasma, serum, urine, non-hemolyzed
24
Q
Fasting is usually required in Urea and Creatinine. TRUE OR FALSE.
A
False (not)
25
elevated level of nitrogenous substances like urea and creatinine in the blood
Azotemia
26
very high plasma urea concentration accompanied by renal failure
Uremia
27
conditions in which circulation through the kidneys is less efficient than usual
Pre-renal
28
characterized by the presence of lesions on
| the parenchyma itself (tubular injury)
Renal causes
29
due to the obstruction in the-urinary tract due to
Post-renal causes
30
```
What classification:
Hemorrhage (blood loss)
Cardiac decompression
Increased protein catabolism
Heatstroke (Dehydration)
Burns (Fluid loss)
```
Pre-renal
31
```
What classification:
Chronic nephritis
Acute glomerulonephritis (AGN)
Polycystic kidney
Nephrosclerosis
Tubular necrosis
```
Renal causes
32
What classification:
Stones
Prostatic enlargement
Tumors
Post-renal causes
33
```
What creatinine ratio?
Low protein diet
Acute tubular necrosis
Repeated dialysis
Hepatic disease
```
Low Ratio <10:1
34
```
What creatinine ratio?
Pre-renal azotemia
-Dehydration
-Catabolic states
-GI bleeding
-High protein diet
```
High ratio = >20:1 (with normal creatinine)
35
Post-renal azotemia
High ratio = >20:1 (with elevated creatinine)
36
______ is inversely related to glomerular filtration rate (GFR)
Plasma creatinine
37
Not affected by protein diet and not reused in the body’s metabolism. Also used to evaluate fetal kidney maturity (2 mg/dL).
Creatinine
38
Most commonly used to monitor renal function, an index of overall renal function. Solely a waste product & not easily removed by dialysis.
Creatinine
39
Creatinine is decreased creatinine during decreased GFR. TRUE OR FALSE.
True
40
Creatine is synthesized in the liver from ____
arginine, glycine and methionine
41
Creatine is transported to tissues and converted to ____
Creatinine phosphate
42
Creatinine is released into the circulation at a relatively constant rate. TRUE OR FALSE.
True
43
Clinical application of Creatinine except:
a. used to determine sufficiency of kidney function and the severity of kidney damage
b. To monitor the progression of kidney disease
c. Urinary creatinine excretion has been used as a measure of the completeness of mid-catch stream urine collections in a given individual
C (24 hour urine)
44
a measure of the amount of creatinine eliminated from the blood by the kidneys, and GFR are used to gauge renal function
Creatinine clearance
45
The methods most frequently used to measure creatinine are based on the ______
Jaffe reaction
46
Creatinine reacts with ____ in _____ solution to form a ____ chromogen
picric acid, alkaline, red-orange
47
Reference method for Jaffe reaction
Isotope Dilution Mass Spectrometry
48
Jaffe reagent ___ and ____
saturated picric acid and 10% NaOH
49
Interferences in creatinine are Folin-Wu & Lloyd or Fuller’s earth method. TRUE OR FALSE
true
50
Which is correctly matched?
A. Lloyds reagent & (Sodium Aluminum Silicate)
b. Fuller’s earth reagent (Aluminum Magnesium Silicate)
c. Both A and B
d. Neither
C
51
In Enzymatic Method of creatinine, it uses ____.
Creatinine Amidohydrolase Method & Creatinase-Hydrogen Peroxide Method
52
Specimen used in creatinine
plasma, serum, urine,
53
_____ samples should be avoided in creatinine test
Hemolyzed and icteric
54
```
Increase Creatinine Except:
A Impaired Renal function
b Chronic nephritis
c Muscular diseases
d CHF
e Decreased muscle mass
```
E
55
```
Decrease Creatinine Except:
a Decreased muscle mass
b Advanced and severe liver disease
c Chronic nephritis
d pregnancy
e inadequate dietary protein
```
C
56
The product of catabolism of the purine (Adenine and Guanine) nucleic acid, relatively insoluble in plasma and can be deposited in the joints and tissue.
Uric Acid
57
Most uric acid is reabsorbed in the ____ and reused
PCT
58
Final breakdown of nucleic acids catabolism in humans
Uric acid
59
Plasma: 95% exists as _____ urate (Uric Acid)
monosodium
60
Clinical Application of Uric acid EXCEPT:
A. To confirm diagnosis and monitor treatment of gout
B. To assist in the diagnosis of renal calculi
C. To prevent nephropathy during chemotherapeutic treatment
D. To assess inherited disorders of cystine metabolism
D
61
involves the chemical reaction of uric acid with alkaline phosphotungstate in a protein-free solution with tungsten blue as the end product
Caraway Method
62
simplest and most specific method, uses uricase to convert uric acid into allantoin; can be measured
spectrophotometrically at ___ nm or coupled with catalase or peroxidase
Uricase Method, 293
63
Negative Interference of Uricase
Hemoglobin and Xanthine
64
measure the hydrogen peroxide produced as uric acid is converted to allantoin
Coupled enzyme methods
65
used to catalyze a chemical indicator reaction
Interference of coupled enzyme methods in uric acid is ____ and _____
Peroxidase or Catalase
| Bilirubin & ascorbic acid
66
Principle in chemical methods of uric acid
Reduction-Oxidation
67
Sodium cyanide in Reduction-Oxidation
Folin, Brown, Newton, Benedict
68
Sodium carbonate in Reduction-Oxidation
Archibald, Caraway, Henry
69
Incubation period after the addition of an alkali to inactivate non-uric acid reactants
Lag phase
70
Specimen used in Uric Acid 1.____ and 2.____ should be avoided
1 heparinized plasma, serum, urine
| 2 Gross lipemia
71
may falsely decrease results in Uric Acid
High bilirubin concentration
72
Significant hemolysis results in low values and salicylates and Thiazides increases values in Uric Acid. TRUE OR FALSE.
True
73
EDTA or fluoride additives are NOT used in uric acid. TRUE OR FALSE.
True
74
Urine specimens must be acidic in uric acid (pH5.5). TRUE OR FALSE.
False (alkaline, pH8)
75
deficiency of hypoxanthine-guanine phosphoribosyl transferase (HGPRT); neurologic symptoms, mental retardation, and self-mutilation
Lesch-Nyhan syndrome
76
first diagnosed between 3rd and 5th decade of life; pain and inflammation of the joints
Gout
77
seen in leukemia, lymphoma, multiple myeloma or polycythemia. Treatment is allopurinol.
Increased nuclear metabolism
78
due to decreased glomerular filtration rate and tubular secretion; >10mg/dL plasma UA which can cause urinary tract calculi
Chronic renal disease
79
```
TRUE OR FALSE.
HYPOURICEMIA:
Hemolytic or megaloblastic anemia
Secondary to glycogen storage diseases
Toxemia of pregnancy and lactic acidosis
Increased dietary intake
Ethanol consumption
```
False (Hyperuricemia)
80
```
TRUE OR FALSE.
HYPERURICEMIA:
Fanconi’s syndrome
Wilson’s disease
Hodgkin’s disease
```
False (Hypouricemia)
81
Formed in the deamination of amino acids during protein metabolism and not useful for renal studies but for liver function
Ammonia
82
Removed from the circulation and converted to urea in the liver and has its significance in impending hepatic coma and terminal stages of hepatic cirrhosis
Ammonia
83
Free ammonia is nontoxic. TRUE OR FALSE
False (toxic)
84
May result from anaerobic metabolic reactions that occur in skeletal muscle during exercise
Ammonia
85
```
Increase ammonia EXCEPT:
A Reye’s Syndrome
B Kidney failure
C cirrhosis
D hepatic coma
E acetaminophen poisoning
```
B
86
monitor hyperalimentation therapy
Blood ammonia
87
used to confirm the ability of the kidneys to produce ammonia
Urinary ammonia
88
ammonia is isolated from the sample and then assayed
Two-step approach
89
Specimen used in ammonia
Whole blood ammonia concentration
90
Venous blood is placed on ice immediately. Samples should be centrifuged at 0°C to 4°C within 20 minutes of collection. Cigarette smoking is a significant source of ammonia contamination. Hemolysis should be avoided. TRUE OR FALSE. (AMMONIA)
True
91
Anticoagulants used in ammonia
Heparin and EDTA
92
The ammonia formed reacts with phenol and alkaline hypochlorite using sodium nitroprusside as catalyst to form indophenol blue (ammonia)
BERTHELOT'S REACTION
93
ammonia formed when it reacts with the Nessler's reagent in the presence of a colloidal stabilizer forms a colloidal suspension of dimercuric ammonium iodide (ammonia)
NESSLERIZATION
Yellow - low to moderate
orange brown - high
94
Ammonium salts, asparaginase, barbiturates, diuretics, ethanol, hyperalimentation, narcotic analgesics
Increased plasma ammonia
95
Diphenhydramine, Lactobacillus acidophilus, lactulose, levodopa, and several antibiotics
Decreased plasma ammonia
96
Glucose at concentrations greater than __ mg/dL interferes in dry slide methods
600
97
is a source of contamination leading to elevated levels
Smoking & Prolong standing
