CARBOHYDRATES II Flashcards
can be used as a sample.
Whole blood, serum , plasma, CSF, serous fluid or urine
preservative in evacuated tubes that prevents glycolysis and stable up to 24 hours at room temperature
sodium fluoride
preservative in evacuated tubes that prevents clotting
potassium oxalate
evacuated tube that contains sodium fluoride and potassium oxalate.
Evacuated gray top tube
most commonly used specimen
Serum
Fasting required is at least?
8 hour not longer than 16 hours
Serum at room temperature, glucose concentration is stable up to ____ hours and up to ____ hours at _____
8
72
4C
specimen that should be process immediately to avoid bacterial contamination.
CSF glucose
Urine glucose in 24-hour specimen can be preserved by adding?
55mL glacial acetic acid
Higher glucose level in capillary blood, ____ higher than venous blood
2-3%
Blood glucose determination
Chemical Method
Enzymatic method
Dextrostix (ONLY ONE)
Chemical method
1. oxidation reduction method
2. condensation method
Enzymatic method
1. glucose oxidase
2. hexokinase
3. glucose dehydrogenase
In alkaline pH Cupric ions is reduced to cuprous ion in the presence of reducing sugar.
Copper reduction method
Most carbohydrates are reducing sugar except
sucrose
Folin wu method (benedict’s test)
Reagent and Result
Reagent: phosphomolybdate
Result: molybdenum blue
Nelson-Somogyi
Reagent and Result
Reagent: arsenomolybdate
Result: molybdenum blue
Neocuproine method
Reagent and Result
Reagent: neocuproine
Result: yellow-orange red complex
( Hagedorn Jensen method)
also known as
Ferric cyanide method
Ferric cyanide method is also known a s
Hagedorn Jensen method
reduce to ferrocyanide in the presence of reducing sugars
Ferric cyanide
From colored reagent (yellow) to colorless and measured at 400 nm.
Ferric cyanide
Reagent of Ferric cyanide method
Regent: hot alkaline solution of ferric cyanide.
Chemical method Used in automated machines.
Ferric cyanide method
Uses hot acidic medium to produce “enol” form of glucose which is the active reducing form of glucose to convert D-glucose to L-glucose.
Ortho -tuloidine method (dubowski method)
(dubowski method) is also called
ortho- tuloidine method
What method?
Glucose + Glacial acetic + heat at 100C = green color measured at 620-630 nm
Condensation method
Ortho -tuloidine method (dubowski method)
The most common method (Enzymatic method), measures D-glucose.
Glucose oxidase method (GOD)
Hexokinase method (HK)
Glucose dehydrogenase method (GDH)
colorimetric method aka
Glucose oxidase
What enzymatic method?
Enzyme glucose oxidase catalyzes the oxidation of glucose to gluconolactone and hydrogen peroxide, then the addition of enzyme peroxidase and chromogenic (oxygen acceptor) results in the formation of color that can be measured.
Colorimetric method
Types of glucose oxidase method
Trinder’s Reaction
Gochman and Smitz method
Polarographic Oxygen Electrode (Beckman analyzer)
Glucose oxidase method
Chromogens
O-dianisidine- blue color
Aminoantipyine- rose pink color
o-toluidine
Dethyl p- phenylenediamine
o-anisidine
3-methyl- 2-benzothiazolinone hydrazone, N,N dimethylalanine
4-aminophenazone
Glucose oxidase
Sources of error
Hemolyzed sample
Icteric sample (presence of bilirubin)
Ascorbic acid
Phosphorylation of glucose by ATP is catalyzed by enzyme ______ to form glucose-6-phosphate and ADP
Hexokinase
co-enzymes
NADH and NAPH (reduced form)
NAD and (NADP) nicotinamide adenine dinucleotide phosphate
If G6PD source is yeast, what hexokinase is used?
NADP
If G6PD source is bacteria, what hexokinase is used?
NAD
derives from Bacillus cereus
Glucose dehydrogenase
The enzyme glucose dehydrogenase (GDH) catalyzes oxidation of glucose to ___?
gluconolactone
Used for home monitoring/self monitoring of blood glucose
DEXTROSTIX method
Quantitative test for glucose in whole blood
DEXTROSTIX method
Uses cellulose strip impregnated with reagents which contains glucose oxidase, peroxidase and chromogen.
DEXTROSTIX method
Laboratory findings in hyperglycemia
Increase plasma and urine glucose
Elevated urine specific gravity
Acidic urine
Elevated serum osmolality
Elevated urine osmolality
Presence of ketonemia and ketonuria
Decrease blood pH (acidosis)
Electrolyte imbalance (low Na Cl and high K)
Criteria for testing prediabetes and diabetes
Obese with a BMI of > 25
Sedentary life style
High blood pressure
History of cardiovascular disease.
High impaired glucose tolerance test (IGT) and impaired fasting glucose (IFG) and HBA1C.
Lipid profile test: Triglycerides (250 mg/dl) and HDL (<35 mg/dl).
History of GDM (female) or delivering an overweight baby ( 9.1 lbs./4 kg).
Female with PCOS (polycystic ovarian syndrome)- high risk for GDM.
Family history of diabetes.
With symptoms of diabetes mellitus
Random blood sugar (RBS)
Results?
≥ 200 mg/dl (≥ 11.1 mmol/L)
With symptoms of diabetes mellitus
Fasting blood sugar (FBS)- most preferred method.
Results?
≥ 126 mg/dl (≥ 7.0 mmol/L)
With symptoms of diabetes mellitus
2-hour post prandial
Results?
≥ 200 mg/dl (≥ 11.1 mmol/L)
With symptoms of diabetes mellitus
Urine glucose
Results?
Positive (glucosuria)
With symptoms of diabetes mellitus
HBA1C
Results?
Greater than 6.5 %
Not used for diagnosis but for monitoring purposes.
Urine glucose
occurs when the blood glucose exceed 180 mg/dl, excess is excreted in urine.
Glucosuria
≥ 200 mg/dl (11.1 mmol/L) two hour or more after mixed meal is diagnostic of DM
Two-hour Postprandial plasma glucose
Serial measurement of plasma glucose before and after glucose is given orally.
OGTT (Oral glucose tolerance test)
administer standard oral glucose load, 75 grams
Post-challenge Plasma glucose
NDDG stands for?
National diabetes data group
FBS
1st hour
2nd hour
3rd hour
at lease 2 values must exceed the following values to confirm GDM
105 mg/dl
190 mg/dl
165 mg/dl
145 mg/dl
Used to diagnosis and for management of diabetes.
GLYCOSYLATED HEMOGLOBIN (HbA1c)
It reflects the blood glucose level for the past 3 months (RBCs life span).
GLYCOSYLATED HEMOGLOBIN (HbA1c)
Glucose combined with hemoglobin to form ?
GLYCOSYLATED HEMOGLOBIN (HbA1c)
Amount of ____ is directly proportional to blood glucose.
GLYCATED HEMOGLOBIN
Method of measurement: affinity chromatography
GLYCOSYLATED HEMOGLOBIN (HbA1c)
Specimen: hemolyzed EDTA blood.
GLYCOSYLATED HEMOGLOBIN (HbA1c)
GLYCOSYLATED HEMOGLOBIN (HbA1c)
Significane
what values indicates
Normal
Diagnostic of pre-diabetes
Diagnostic of diabetes
5.6%
5.7-6.4%
> or = 6.5%
Diabetic patient should maintain___ and below level. (above leads to diabetic complications)
6 %
Diabetic patient should maintain a ≤ 6 % HB1c.
Uncontrolled blood sugar level will result to
macrovascular and microvascular complications.
For patient with diabetes and GDM. monitors the blood glucose level on a daily basis using a
glucose meter
The purpose of monitoring blood glucose level is to?
maintain glycemic control and prevent hypoglycemia
helps to adjust insulin dosage, dietary intake or physical activity.
Glycemic control
