special chem rotation

how is liver disease characterized on protein electrophoresis?

general increase in gamma globulins with a decrease in albumin

what are the positive acute phase reactants?

complement, haptoglobin, CRP, alpha-1 antitrypsin, fibrinogen, and globulins

what are the negative acute phase reactants?

pre-albumin, albumin, and transferrin

what are the lab values associated with Wilson’s disease?

increased urine copper and liver enzymes, mild anemia, and decreased ceruloplasmin

what are the conditions of a typical protein electrophoresis?

agarose gel kept at 8.6 pH and electrophoresed at 120 mV

what is the purpose of citrate gel?

hemoglobin electrophoresis

what order of kinetics is drug toxicity most likely?

zero order

how many half lives must pass to determine the steady state of a drug?

4-5

what fluids are drugs excreted in?

urine, bile, sweat, and saliva

what is first pass metabolism?

the amount of drug metabolized from the hepatic portal vein

what is digoxin used to treat?

CHF

what drugs are considered stimulants?

amphetamines, cocaine, PCP, nicotine, and caffeine

in thin layer chromatography, if an acidic drug is extracted into a polar solution, what must the pH of the mobile phase be?

opposite of the drug, basic in this case

when is the mobile phase of TLC similar in pH to the drug that is being extracted?

if the drug is extracted into an organic solution

how do gel barrier tubes affect the measurement of lipophilic drugs?

it causes a false decrease of the drug due to the gel absorbing it

when are trough specimens collected?

right before the next dose

how many times should infusion lines be flushed before drawing a specimen?

6 times

what drugs are considered anticonvulsants?

phenytoin, phenobarbital, carbamezepine, primidone, and valproic acid

what drugs are considered immunosuppressive drugs?

tacros and cyclosporine

how does a non-polar mobile phase used with a polar drug and chromatagram affect the migration of the band?

causes slower migration and therefore decreased Rf

how is lead measured?

atomic absorption

how are volatiles measured?

head space GC

how are drugs of abuse measured?

GC-MS and HPLC

how does decreased purity of water affect the specimen measurement?

it causes a false increase

how is primary ovarian insufficiency indicated?

increased LH and FSH with decreased estrodiol

what lab value is decreased in conjunction with decreased IGF-1? why?

growth hormone will also be decreased because growth hormone stimulates the release of IGF-1 from the liver

what is 1 mol equivalent to?

1 mEq

what units is a % solution measured in?

g/dL

what is the formula for neutralization?

volume 1* normality1= volume 2*normality 2

what is the formula for beer’s law?

(abrosrbance of the unkown/absorbance of the standard)* concentration of the standard

what is the advantage of using a dual beam spec over a single beam spec?

it compensates for variance in intensity by using light from both the reference and analytical cells

what happens to the signal in competitive assays as the analyte concentration increase?

the signal decreases bc the analyte of interest is outcompeting the labeled antigen that was initially added to the test system

what two labels cannot be used in homogenous assays?

chemiluminescent and radioactive because there is no alteration in the signal when antibody binding occurs

when may biotin cause a false decrease?

if it is already present in elevated concentrations within the patient, it may bind up the avidin that is meant to be bound to added biotin to the antibody, which may cause the antibody not to be bound to the label that is attached to avidin; this may also occur if biotin is not washed off prior to adding avidin in a competitive immunoassay

what is the most sensitive type of immunoassay?

noncompetitive chemiluminescent EIAs

why should quartz or plastic cuvettes be used for UV spec instead of glass?

because glass can absorb light past a certain wavelength, causing a false increase in absorbance

how is the setup for fluorometry different from nephelometry?

although both place the cuvette at an angle away from the light source, fluorometry requires the use of two filters to select for the excitation wavelength and the emission wavelength of the fluorophor

can sandwich immunoassays be competitive?

no; sandwich is synonymous for noncompetitive

what type of assays can the hook effect occur in?

noncompetitive

what is the difference between heterogenous and homogenous assays?

homogenous assays do not require a separation step, whereas homogenous assays do

what immunoassays are considered homogenous?

EMIT, CEDIA, and FRET

how are ELISAs different from EMIT?

ELISAs are considered heterogenous due to requirement of washing steps, whereas EMIT is a homogenous technique that is common among small molecules such as drugs or hormones

what is CEDIA?

an enzyme immunoassay that involves two inactive fragments that spontaenously reassemble to form active enzyme in the presence of the antigen of interest

how does a chemiluminescent assay work?

a flash of light is produced in response to the presence of the immunoassay

how can heterophile antibodies interfere with immunoassays?

they can cause either false positive or false negatives depending on the nature of the assay; for example, human anti-mouse antibodies (HAMA)s can cause a false positive for hCG detection due to binding to conjugate antibodies but can cause a false negative if bound to capture antibodies in other immunoassays

how can it be determined that heterophile antibodies are present within a specimen that is undergoing dilutions?

if linearity is lost within the dilutions i.e. the dilutions do not increase/decrease sequentially

what kind of label is used for CLIA?

acridium ester

how is standard deviation calculated?

square root of the sum of the mean subtracted from each value and squared, then divided by the number of specimens -1

how is coefficient of variation calculated?

standard deviation/mean*100

how is sensitivity and specificity calculated?

sensitivity= true positive/true positives+false negatives

specificity= true negative/true negatives+false positives

how is positive predicitive value calculated?

true positives/true positives+false positives

what value is most characteristically increased in Zollinger-Ellison? what clinical presentation may this associate with?

increased gastrin from gastrinomas within the pancreas, causing multiple peptic ulcers and constipation

what can cause Vitamin B12 excretion to remain low in a Schilling’s test, even after injection of Vitamin B12?

malabsorption, renal dysfunction, and incomplete urine collection

what are the conditions associated with the following abnormal values: Vitamin D, Vitamin K, folic acid, transthyretin, and Vitamin C

• Vitamin D deficiency= Ricket’s

• Vitamin K deficiency= hemorrhage and coag issues

• folic acid deficiency= pregnancy and lactation

• transthyretin deficiency= poor nutrition

• Vitamin C deficiency= scurvy

what lab values are associated with Hashimoto’s?

elevated TSH with decreased free T4; potential anti-TPO and anti-TG

what lab values are associated with Grave’s disease?

decreased TSH with increased free T4; potential TSH receptor antibodies

what condition can ectopic ACTH cause?

Cushing’s syndrome

what are the indicators of Addison’s disease?

decreased cortisol with increased ACTH

what are the indicators of Cushing’s syndrome?

increased cortisol with decreased ACTH

what does hCG look like in an ectopic pregnancy?

decreased

what element is used to perform autoradiography?

phosphorus

what condition is associated with decreased AFP, decreased urine estriol and hCG, and normal inhibin A?

trisomy 18

what condition is associated with increased AFP and normal urine estriol, hCG, and inhibin A?

neural tube defect

what condition is associated with decreased AFP and urine estriol, increased hCG and inhibin A, nuchal transluscency, and decreased PAPP-A?

down syndrome

how does a hydatiform mole affect hCG?

it causes extremely high hCG

what is the formula for retention factor?

retention time of unkown/retention time of internal standard

how is the concentration of an unknown drug calculated in TLC?

(peak height unknown/peak height IS)*(peak height IS/peak height std)*std concentration

what is the difference between major and minor thalassemia?

major thalassemia causes anemia, while minor thalassemia causes no anemia

what is the most severe form of alpha thalassemia?

hemoglobin barts hydrops AKA alpha thalassemia major

what is the order of hemoglobin bands from in acidic hemoglobin electrophoresis from anode to cathode?

C, S, A, F

what is the order of hemoglobin bands in alkaline hemoglobin electrophoresis from anode to cathode?

A, F, S, C

how does hydroxyruea treatment affect hemoglobin electrophoresis?

increased hgb f

how do transfusions on a sickle cell patient affect hemoglobin electrophoresis?

small amount of A1

what abnormal hgb comigrates with with hgb a in alkaline hemoglobin electrophoresis?

hgb d

what is the normal electrophoretic pattern of CSF?

one prealbumin band and two transferrin bands

what is the purpose of immunotransfixation?

to identify elevations of certain immunoglobulins when presented with an abnormal protein electrophoresis

what is the detection antibody of a RAST assay?

labeled anti-IgE

what is 5-HIAA used to determine?

carcinoid syndrome

what are the associated cancers with each marker: CEA, HCG, AFP, PSA, CA 125, CA 15-3, TG, and beta-2 microglobulin

• CEA= colon cancer

• HCG= trophoblastic disease

• AFP= hepatocellular carcinoma

• PSA= prostate cancer

• CA 125= ovarian cancer

• CA 15-2= breast cancer

• TG= thyroid cancer

• beta-2 microglobulin= multiple myeloma