Clinical Chemistry Flashcards
What could cause an elevated specific gravity but normal osmolality?
heavier molecules such as protein or glucose
What are the normal values for CSF glucose, protein appearance, and WBC’S?
Glucose: 50-80 mg/100 mL
Protein:15-45 mg/dL,
Appearance: clear and colorless,
WBC:0-5
Why is CO toxic?
prevents binding of Hgb to oxygen
Know the abnormal and normal metabolism of bilirubin, including what is increased and/or decreased in the serum, urine, and/or feces
-Total Bili 0.2-1.0 mg/dL
-Conj Bili 0.0-0.2 mg/dL;
-Unconj Bili 0.2-0.8 mg/dL
-Prehep: too much bili to liver, incr in urine/feces, (hemolytic anemias)
-Hepatic: problem with liver itself, incr in urine/feces (liver disease)
-Posthep: Bili obstruction, decr/absence urobili in urine/feces (stones,tumors)
e.g. obstructive jaundice=decr. fecal urobilinogen,
increased bile pigments=jaundice
Be able to interpret oral and intravenous GTT results
(2 hour plasma glucose) Normal: 200 mg/dL
Give precautions for bilirubin specimen handling
- protect from light
- run ASAP
- no hemolysis
What enzyme tests cannot be preserved by freezing
LD
What is the cause of postprandial lipemia?
chylomicrons
How does the electrophoretic pattern of plasma differ from that of serum?
sharp fibrinogen peak in plasma
What is the order of migration of proteins on electrophoresis at pH 8.6?
fastest-albumin, A1, A2, Beta, Gamma(slowest)
What is the principle enzyme in saliva?
amylase
The immunoglobulins migrate with what protein on electrophoresis at pH 8.6?
gamma globulin
How do oral contraceptives affect total T4 and TBG in competitive binding
assays?
increased in both
Creatinine is the breakdown product of what substance?
Creatine
What tests are affected by hemolysis?
ACP, ALP, ALT, AST, BILI, CBC, CK, LD, aPTT, PT
What is the normal bicarbonate to dissolved CO2 ratio?
20:1
What is the anticoagulant of choice for blood gas analysis?
Heparin
How is serum globulin usually determined?
serum globulin=total protein-albumin
What is the predominant form of thyroid hormone in the circulation?
Thyroxine (T4)
How is a bloody CSF handled in the chemistry lab?
spin it down and analyze fluid; mention presence of blood
What is the unique value of enzymes as reagents?
specificity
What are the major intracellular and extracellular anions and cations?
intracellular anion: phosphate
intracellular cation: potassium
extracellular anion: chloride
extracellular cation: sodium
What is the normal pH of blood?
7.35-7.45
Differentiate a Transudate from and exudate.
transudate- clear, no clots, SG 1.015
exudate- cloudy,clots,SG>1.015
What protein is a contributing factor in edema formation?
albumin
How is the blood glucose level affected if the serum is left sitting on the clot for several hours?
decrease by 10% per hour
What is the most accurate pipette for measuring a 1 mL volume?
Oswald-Folin volumetric
What type of fast does the patient undergo for lipid studies?
12 hour
Be able to calculate problems on:
C1V1 = C2V2
can also be used for Normality
N1V1=N2V2
Be able to calculate problems on:
Creatinine Clearance
(Ucr)(Vu) / (Pcr)(T)
T=1440 minutes
Be able to calculate problems on:
Normality
N = grams divided by GEW divided by Liters
GEW=GMW divided by the total positive valence of ions in the compound
Be able to calculate problems on:
Percent Solutions
(w/w) {ex.} 5%=5/100=0.050
(w/v) {ex.} 10/100=x/1000 x=100
(v/v) {ex.} 2/100=x/50ml
Be able to calculate problems on:
Dilutions
Initial/preceding dilution X (x)= dilution needed
Ex. 1:10 X(x)=1:20 {solve for x}
Be able to calculate problems on:
Molarity
M = grams divided by GMW divided by Liters
GMW=add molar masses of each element in a compound; M is measured in moles per liter (mol/L)
Be able to calculate problems on:
Beer’s Law
concentration and absorbance in photometric determinations Cu=(Au)(Cs)/As -Concentration standard (Cs) -Concentration unknown (Cu) -Absorbance standard (As) -Absorbance unknown (Au)
Be able to calculate problems on:
Anion Gap
(sodium + potassium)-(chloride+bicarbonate) OR
sodium-(chloride+bicarbonate)
Know the principle behind the following:
Kjeldahl protein technique
conversion of nitrogen into ammonium; reference method for total protein determination
Know the principle behind the following: Biuret method
directly proportional to the number of peptide bonds present; specifically reacts with least 2 peptide bonds or more (tripeptide or larger)
Know the principle behind the following:
Osmolality
freezing point depression
Know the principle behind the following:
Creatinine clearance/GFR
Creatinine clearance tests GFR based on assumption that all creatinine passes into the urine. (GFR = volume of plasma filtered by the glomerulus per unit of time; GFR=V/t)
Know the principle behind the following:
Nephelometer
measurement of light is directly proportional to the number of particles in solution
Know the principle behind the following:
Fluorometer
measurement of light excited by a UV light source
Know the principle behind the following:
Sweat Chloride
uses pilocarpine through an electric current into the skin
Know the principle behind the following:
Oral GTT
detects abnormal glucose metabolism
Know the significance of the following terms to clinical chemistry:
Glycosylated Hb
HgA1C give a picture of PT blood glucose concentration over the past 3 months
Know the significance of the following terms to clinical chemistry:
Intrinsic Factor
required for B12 absorption
Know the significance of the following terms to clinical chemistry:
Jaffe reaction
determines creatinine levels
Know the significance of the following terms to clinical chemistry:
3 hour GTT
borderline fasting blood sugar pts
Know the significance of the following terms to clinical chemistry:
Kernicterus
Kernicterus is a bilirubin-induced brain dysfunction.
Know the significance of the following terms to clinical chemistry:
+/- 2SD
includes 95.5% of values
Know the significance of the following terms to clinical chemistry:
Hollow Cathode Lamp
used in atomic absorption
Know the significance of the following terms to clinical chemistry:
Pheochromocytoma
abnormal adrenal medulla which causes increased VMA, norepinephrine, and epinephrine
Know the significance of the following terms to clinical chemistry:
VMA
vanillylmandelic acid - a test for catecholamine-secreting tumors performed on a 24-hour urine specimen; it is based on the finding that vanillylmandelic acid is the major urinary metabolite of norepinephrine and epinephrine
Know the significance of the following terms to clinical chemistry:
5-HIAA
increased in cancers involving entero chromofins of GI tract
Know the significance of the following terms to clinical chemistry:
Berthelot Reaction
hydrolysis of urea
Know the reagents used in the following test:
Prostatic Acid Phosphatase
L tartrate
Know the reagents used in the following test:
Urobilinogen
p aminobenzaldehyde
Know the reagents used in the following test:
BUN
diacetyl monoxime
Know the clinical significance of the following test:
Urinary 17-ketosteroids
increased in adrenal cortex
Know the clinical significance of the following test:
Duodenal Fluid Testing
diagnose pancreas disease
Know the clinical significance of the following test:
HDL Cholesterol
High Density Lipoprotein Cholesterol- it is not readily catabolized by most cells and dose not serve as a source of fuel
Know the clinical significance of the following test:
AFP (Tumor marker)
alpha feta protein;hepatoma
Know the clinical significance of the following test:
LD
increased in MI
Know the clinical significance of the following test:
CK
increased 1st in MI
Know the clinical significance of the following test: Acid Phosphatase (vaginal fluid)
rape
Know the clinical significance of the following test:
CK isoenzymes
CKMB(heart)increased in MI
CKMM muscle
CKBB brain
Know the clinical significance of the following test:
Uric Acid
increased in gout
Know the clinical significance of the following test:
Sweat Chloride
CF
Know the clinical significance of the following test:
GGT
GGT levels are elevated in conditions such as Acute Pancreatitis, Diabetes Mellitusm and MI
Know the clinical significance of the following test:
SGOT/AST
increased in MI, viral hepatitus, skeletal muscle disease
Know the clinical significance of the following test:
5-HIAA
5-Hydroxyindoleacetic acid is the main metabolite of serotonin
Know the clinical significance of the following test:
Ionic Calcium
low in tetany
Know the clinical significance of the following test:
Amylase
increased in pancreatic diagnosis
Know the clinical significance of the following test:
Creatinine
is the indicator of a good kidney function. High creatinine means that the kidney is not filtering well or not in good function
Know the clinical significance of the following test:
ALT (Alanine Aminotransferase)
confined mainly to evaluation of hepatic disorders: have a longer half-life
Know the clinical significance of the following test:
Anion Gap
indicating an increase in one or more of the unmeasured anions in the serum and also as a form of QC for the analyzer used to measure these electrolytes
Patients with an increased catabolism of purines most likely have an increased serum
concentration of what substance?
uric acid
How would the urine volume of a patient with diabetes insipidus be affected upon
administrations of ADH?
decrease
Recognize erroneous results caused by drawing blood from an IV site.
transferring blood from a syringe to a tube
The serum protein electrophoresis pattern in multiple myeloma shows what abnormality?
spike in the gamma globulin
Know the normal values for LDL, HDL, cholesterol and triglycerides.
HDL: 40-75 mg/dl
LDL: 50-130 mg/dl
Tri: 60-150 mg/dl
Cholesterol: 140-200 mg/dl
What substance in the intestines is required for the absorption of vitamin B12?
intrinsic factor
List three enzymes whose clinical significance is related to the detection of a MI.
AST
CK
LD