Exam3 Flashcards
What is the normal glucose concentration of serum?
80-100 mg/dL
What are some of the requirements that must be adhered to during an oral GTT?
fasting at least 10 hours, not more than 16 hours; done in the morning; refrain from eating, drinking, smoking, and exercise, normal to high carb intake for 3 days
What is the order of motility of serum proteins during an electrophoresis?
albumin (fastest), alpha-1, alpha-2, beta fractions, gamma
Why can the biuret method not be used for determining CSF or urine protein?
lacks sensitivity, cannot detect low concentrations of protein
What does the biuret reagent specifically react with?
tripeptides or larger
What is the reference method for total protein determination?
Kjeldahl
Which method for measuring albumin is most commonly used in automated instruments?
dye binding method
What SPE abnormality is seen in multiple myeloma?
gamma globulin is increased
What SPE abnormality is seen in nephrotic syndrome?
alpha-2 globulin and beta are increased
Glucose in CSF is approximately what fraction of the amount of glucose in the blood?
2/3
In bacterial meningitis, what would be the expected results for CSF protein?
increased
In bacterial meningitis, what would be the expected results for CSF glucose?
decreased
What anticoagulant is used to prevent glycolysis?
sodium fluoride
What is the action of ACTH on blood glucose levels?
increases
What is the action of glucagon on blood glucose level?
increases
What is the action of glucocorticoids on blood glucose level?
increases
What is the action of insulin on blood glucose level?
decreases
What is the action of epinephrine on blood glucose level?
increases
What is the action of the enzyme glucose-6-phosphate dehydrogenase?
removes hydrogen from glucose-6-phosphate, gives it to NADP
What technique is used to identify patients with familial hyperlipoproteinemia?
electrophoresis
What is the normal value for albumin?
3.5-5.0
What is the normal value for globulin?
2.5-3.5
What is the normal value for total protein?
6.0-8.5
What phenomenon causes the gamma globulins to move toward the cathode in SPE, even though they are negatively charged?
electroendosmosis (EEO)
What specific form of hemoglobin is used to monitor patients with Type 1 diabetes mellitus?
A1c
How is globulin in serum routinely determined?
(total protein) - (albumin)
Which fraction of lipoprotein contains the highest percentage of protein?
HDL
What is the order of migration, beginning at the origin, of lipoproteins?
chylomicrons, prebeta, beta, alpha
What is the desirable level of total cholesterol in serum?
less than 200 mg/dL
What would be the most likely explanation if a patient’s laboratory results indicated elevated total cholesterol and triglyceride levels but a normal lipoprotein pattern?
patient is not fasting
Which lipoprotein fraction is responsible for post-prandial lipemia?
chylomicrons
If plasma is used instead of serum for electrophoresis, what change will be observed?
fibrinogen spike in beta gamma region
What dyes can be used for the detection of albumin?
bromocresol green, bromocresol purple, methyl orange, HABA
What does HABA stand for?
2,4’-hydroxyazobenzenebenzoic acid
What is considered to be the desirable level of HDL?
> 40 mg/dL
What is the value for a normal two-hour post prandial glucose?
less than 140 mg/dL
In a normal glucose tolerance curve, the glucose level returns to a normal fasting level in how many hours?
3 hours
Name four blood constituents that can produce a falsely decreased cholesterol level due to interference with the enzymatic cholesterol assay.
uric acid, ascorbic acid, bilirubin, glutathione
What is the electrophoretic classification of HDL?
alpha
What is the electrophoretic classification of LDL?
beta
What is the electrophoretic classification of VLDL?
prebeta
Which lipoprotein has a protective effect against coronary artery disease?
HDL
A protein isolated from a lipoprotein which is also affiliated with certain lipoproteins is referred to as a?
apoprotein
What is the main function of lipoproteins in the body?
transport of body lipids throughout blood stream
Describe the glucose tolerance test results for diabetes mellitus
elevated after 3 hours, starts high, stays high, takes longer to return to normal
Describe the glucose tolerance test results for hypoglycemia
lower than normal after three hours, then normal, then falls below fasting levels
Describe the normal glucose tolerance test results
at one hour may be slightly elevated, starts to decrease at 2 hour mark, and back to normal fasting levels at hour 3
Why is the performance of electrophoresis on CSF more difficult than SPE?
protein concentration is low; concentrate it 100X
Patients with borderline blood glucose levels are most often further tested by performing what test?
3 hours oral GTT
What is actually measured in the hexokinase method for glucose?
NADPH
What is the normal range for spinal fluid glucose?
40-70 mg/dL
What period of fasting is required for patients for whom the doctor has ordered lipid panels?
12 hours minimm
What is the reaction that takes place during the biuret procedure?
cupric ions with peptides bonds (violet color)
What precautions must be taken prior to collecting a specimen for lipid analysis?
12 hours fasting; 2 week normal diet; no medications that affect lipids; defer 2 months after surgery, AMI, or serious illness
What is the most specific method for determining plasma cholesterol?
cholesterol oxidase enzymatic reaction
What protein, when found in increased amounts, lowered the risk of coronary heart disease?
apolipoprotein A1
What is the only diagnostic purpose for performing a phospholipid measurement?
Riemann Pick disease
What unusual electrophoretic serum protein pattern is seen in cirrhosis of the liver?
beta gamma bridge
What would be the expected shape of a GTT curve if the patient has malabsorption syndrome?
no change in curve resulting in a flatline
What test should be done if a patient has malabsorption syndrome?
IV GTT test
What test may be used to assess the average plasma glucose level that a patient has maintained during a previous 2-3 month period?
glycosulated hemoglobin (to which A1c belongs)
What is the enzyme that causes the release of hydrogen peroxide when it reacts with glucose?
glucose oxidase
What would happen to the glucose in a blood specimen if it was drawn in a clot tube and was left uncentrifuged at room temperature?
decreased by 7 mg/dL per hour
How much glucose is used in an adult GTT test?
75 g
What reagent is used for color development in the Libermann-Burchard reaction?
combination of acetic anhydride sulfuric acid and acetic acid
What adjustment is made to an OGTT if hypoglycemia is suspected?
additional testing at 4 and 5 hours
β-lipoproteins contain a high percentage of?
cholesterol
pre-β-lipoproteins contain high percentage of?
triglycerides
How would a physician view the prognosis of a patient with an elevated HDL level?
good, not at high risk; patient is protected from arthrosclerosis
What is the most likely explanation of a milky serum?
increased chylomicrons
What enzyme catalyzes the hydrolysis of triglycerides?
lipase (LPL)
What is the normal range for spinal fluid protein?
15-45
What compound is used to stimulate the pancreas to produce insulin?
tolbudamide
Ultracentrifugation separates lipoproteins into various categories based on what physical property?
density
What stains can be used to stain the protein bands obtained from SPE?
ponceau S, amino black 10 B, bromphenol blue, lissamine green
At what pH is routine SPE performed?
8.6
What is gestational diabetes?
diabetes during pregnancy
What is meant by the term renal threshold?
the glucose levels in the blood above which glucose spills over into the urine
What is the renal threshold for glucose?
160-180 mg/dL
What type of diabetes generally occurs in adults?
type 2
Name a test that can be used to determine the risk of RDS in newborns
L/S ratio
