1 urinalysis. urine sediment seminar no. 13. 2 q. 2 test for glc, kb
TRANSCRIPT
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Urinalysis. Urine sediment
Seminar No. 13
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Q. 2
Test for Glc, KB
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Test for Reagent(s) / Principle Problem(s)
Glucose glucoseoxidase + peroxidaseascorbate false negativity
peroxides false positivity
KBsodium nitroprusside
Na2[Fe(CN)5NO]fresh sample needed to prevent the decarboxylation of acetoacetate
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glucose + O2 gluconolactone + H2O2
H2O2 + H2A 2 H2O + A
glucoseoxidase
peroxidase
colourless chromogen
coloured product
colourless colourless colourless colourless
colourless colourless
Enzymatic test for glucose
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Test for blood (Hb), bilirubin
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Test for Reagent(s) / Principle Problem(s)
Bloodperoxidase like activity of heme
Fe salts false positivity
Bilirubin
Ubgdiazonium salts give coloured azo-compounds R-N=N-R’
fresh sample needed
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Test for proteins, nitrites
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Test for Reagent(s) / Principle Problem(s)
ProteinsProtein error of some acid-base indicators
Sensitivity mainly for albumin
Nitrites
Ar-NH2 + HNO2 + HCl
Ar-NN+ Cl- + 2 H2O
H-Ar’
Ar-N=N-Ar’ + HCl
•Fresh urine needed
•Absolutly clean vessels
•4 h urine retention in bladder
•No antibiotics
•High ascorbate false negativity
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Urine sediment
• suspension material obtained by centrifugation of fresh
urine sample under defined condition
• semiquantitative quantitative
• chemical sediment – crystals of various compounds (salts)
• biological sediment – cells (RBC,WBC), casts, bacteria
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Factors involved in renal stones formation
• increased concentrations of certain ions (Ca2+, Mg2+ ...)
• extreme values of pH of urine
• low intake of fluid (low diuresis)
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Insoluble compounds
CompoundInsolubility pH range
Acid Neutral Alkaline
Uric acid
Ammonium hydrogen urate
Calcium oxalate
Calcium hydrogen phosphate
Hydroxyapatite
Ammonium magnesium phosphate
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Write formulas
Calcium oxalate
Calcium hydrogen phosphate
Hydroxyapatite
Ammonium magnesium phosphate
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Calcium oxalate Ca(COO)2
Calcium hydrogen phosphate CaHPO4
Hydroxyapatite Ca5(PO4)3OH
Ammonium magnesium phosphate NH4MgPO4
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Uric acid (lactim) is a diprotic acid
N
N
N
NH
OH
HO
OHN
N
N
NH
OH
HO
ON
N
N
NH
OH
O
O
uric acid hydrogen urate urate
pKA1 = 5.4 pKA2 = 10.3
2,6,8-trihydroxypurine
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Mineralogical name Chemical name
Weddellit calcium oxalate dihydrate
Whewellit calcium oxalate monohydrate
Struvit magnesium ammonium phosphate hexahydrate
Brushit calcium phosphate dihydrate
Uricit uric acid
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Q. 7
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Q. 8
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Bacterial urease catalyzes the hydrolysis of urea
H2N-CO-NH2 + H2O 2 NH3 + CO2
NH3 + H2O NH4+ + OH-
alkaline urine precipitation of CaHPO4
ammonia
weak base
ammonium
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Q. 10
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• oxalates
• see the table in lab manual, p. 109
There are three sources
of oxalic acid in
the body
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Three sources of oxalic acid in the body
60 % catabolism of glycine and ethanolamine
30 % catabolism of ascorbate
10 % plant food
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Glycine oxalate
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COOHCH2
NH2
COOHCH
NHFAD FADH2
O2H2O2
H2O
NH3-H
C
O O
C
OH
glyoxalát
HO
C
O O
C
OHoxalát
H
C
O
S CoA-CO2
formyl-CoA
oxid.
glyoxylate
oxalate
iminoacetate
Glycine oxalate
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Ethanolamine oxalate
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Content of oxalic acid in some plant foods
Food Content (mg/kg)SpinachChard (mangold)RhubarbTeaCocoaBambooBeetrootCabbageWheat flourBrocoliTomatoes
5000 - 100005000 - 90002000 - 96006000 - 70003000 - 45001600 - 4500300 - 1400100 - 1200400 - 750100 - 50050 - 100
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Chard (mangold)
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Rhubarb
• a herb with long reddish leaf-stalks, rich in oxalic acid
• rhubarb juicy stalks are edible when cooked and sweetened
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Intoxication and oxidation of ethylene glycol leads to
oxalic acid through a number of intermediates
oxid.COOH
COOH
glyoxalová kyselina
CH2OH
CH2OH
CHO
CHO
COOH
CH2OH
oxid.CHO
CH2OH
COOH
CHO
ethylenglykol glykolaldehyd
glyoxal
glykolová kyselina
št'avelová kyselina
oxid.
oxid.
oxid.
oxid.
ethylene glycol
glycolic acid
glycolaldehyde glyoxylic acid(glyoxylate)
oxalic acid(oxalate)
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Q. 12
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Some food components conduce to urolithiasis
Food Commentary
Meat (excess)
Milk products
Mineral waters
Spinach
Rhubarb
Vitamin C (excess)
cystein catabolized to SO42- + 2H+ urine acidification
rich in Ca2+ and phosphates
some of them are rich in Ca2+ and Mg2+
contains oxalic acid (up to 1 %)
contains oxalic acid (up to 1 %)
catabolized to oxalic acid
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SubstancePlasma concentration (mmol/l)
Urine excretion (mmol/d)
Na+ 133 - 150 100 - 260
K+ 3.8 - 5.5 40 - 90
Ca2+ 2.0 - 2.7 1 - 6
Mg2+ 0.6 - 1.0 1 - 12
HCO3- 21 - 27 1 - 2
Cl- 97 - 108 120 - 260
H2PO4- + HPO4
2- 0.7 - 1.5 10 - 30
SO42- 0.2 - 0.5 8 - 35
Urea 2 - 8 330 - 600
Uric acid 200 - 420 μmol/l 2 - 3
NH4+ 5 - 50 μmol/l 30 - 50
α-Amino nitrogen 2 - 4 4 - 14
Creatinine 50 - 125 μmol/l 9 - 16
Total proteins 65 - 85 g/l < 150 mg/d