C706 study

Radioimmunoassay process

Radioimmunoassay (RIA)

a highly sensitive, in vitro laboratory technique used to measure the concentration of specific antigens (such as hormones, drugs, and proteins) in biological samples

Antigen (Ag)

a substance (e.g., protein) that is able to induce the production of an antibody in the body and binds to that antibody very specifically

Antibody (Ab)

usually a protein that is produced in immunologic response to an antigen and forms a specific complex with the antigen.

Schilling Test

Indicates vitamin B12 absorption. Vitamin B₁₂ labeled with ⁵⁷Co is administered to fasting patients, and the 24-h urinary excretion of the tracer is measured and used as an index of the disease state.

Blood volume radioimmunoassay

¹²⁵I-Labeled Serum Albumin Method or ⁵¹Cr-Labeled Red Blood Cell Method. Radiolabelled blood sample compared to standard and RBC conc. to determine totoal blood volume

Normal adult blood volume

4000-5500mL

RBC survival

⁵¹Cr-Labeled RBC. 24hr sample taken to represent 100% cell survival. RBC sample acquired every 48hr until latest sample is less than half of the 100% sample

RBC survival time

120 days (average). Mean T1/2 of 28 days

Cr-51 characteristics

27.7 day half life, 320keV principle gamma emission

DTPA

Diethylenetriamine penta-acetic acid

pernicious anemia

autoimmune condition that prevents your body from absorbing vitamin B12

Polycythemia Vera

a rare blood cancer that causes the bone marrow to produce too many red blood cells, which thickens the blood and increases the risk of dangerous blood clots