plasma 11-deoxycorticosterone

Plasma 11-deoxycorticosterone is a 21-carbon steroid hormone, mainly produced by the adrenal cortical bundle, which is a mineralocorticoid with a secretory function and action similar to 18-hydroxy-deoxycorticosterone. Basic Information Specialist classification: growth and development examination classification: blood examination Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: No relevant information. Normal value: Plasma 11-deoxycorticosterone (radioimmunoassay): 0.06-0.324 nmol/L Above normal: Adrenal syndrome, Cushing's disease, primary aldosteronism, late pregnancy. negative: Positive: Tips: Due to the physiological fluctuation of cortisol in the blood, it is the highest in the morning, gradually decreases afterwards, and falls to the lowest level after falling asleep. Clinically, blood samples are generally taken at around 8:00 in the morning for examination. Normal value Radioimmunoassay is 0.06 to 0.324 nmol/L. Clinical significance Elevation is seen in adrenal syndrome, Cushing's disease, primary aldosteronism, and late pregnancy. High results may be diseases: congenital adrenal hyperplasia considerations Due to the physiological fluctuation of cortisol in the blood, it is the highest in the morning, and then gradually decreases, and falls to the lowest level after falling asleep. Clinically, blood samples are generally taken at around 8:00 in the morning for examination. Inspection process The method is divided into three steps, namely antigen-antibody reaction, B and F separation, and radioactivity determination. (1) Reaction of antigen with antibody: The specimen (non-labeled antigen), labeled antigen and antiserum are sequentially dosed into a small test tube, and allowed to stand at room temperature (15 to 30 ° C) for 24 hours to fully compete for binding. (2) Separation of B and F: There are various separation techniques, and the precipitation method is commonly used. 1 second antibody precipitation method: also known as diabody method, after the test antigen specifically reacts with the first antibody, the corresponding second antibody is added, so that the formed antigen-first antibody-second antibody complex is co-precipitated. The labeled antigen B is separated from the free antigen F by centrifugation. This method is a specific precipitation, complete separation, low non-specific binding. However, the amount of the second antibody is large and the cost is high. In addition, the serum concentration and the presence or absence of anticoagulants can affect the results to some extent. 2 Polyethylene glycol (PEG) precipitation method: the protein is in an isoelectric point state, and the hydration layer is destroyed to cause protein precipitation. The advantage of this method is that PEG is convenient to prepare, inexpensive, and rapid to separate. The disadvantage is that there are many non-specific precipitates and the separation is incomplete. 3Second antibody-polyethylene glycol precipitation method: This method not only has the advantage of rapid precipitation of PEG method, but also maintains the effect of specific precipitation of second antibody, reduces the amount of second antibody, and reduces the concentration of PEG, so that non-specific precipitation Reduced material. 4 Activated carbon adsorption method: the free part of small molecules is adsorbed by the surface activity of activated carbon. For example, a layer of dextran is coated on the surface of the activated carbon to make a mesh having a certain pore diameter on the surface, thereby allowing small molecules of free antigen or hapten to escape and being adsorbed, while the macromolecular complex is excluded. After the antigen and the antibody are reacted, the dextran-activated carbon is added and allowed to stand for 5 to 10 minutes, so that the free antigen is adsorbed on the activated carbon particles, and the particles are precipitated by centrifugation, and the supernatant contains the labeled antigen. (3) Determination of radioactivity: After separation of B and F, the radioactivity can be measured. There are two types of measuring instruments: a liquid scintillation counter (measuring beta rays) and a crystal scintillation counter (measuring gamma rays). The unit of counting is the number of electrical pulses output by the detector in units of cpm (number of pulses/min). A standard curve is required for each measurement, and the different concentrations of the standard antigen are plotted on the abscissa, and the corresponding radioactivity measured is plotted on the ordinate. The radioactivity may be optionally B or F, and the calculated values ​​B/B+F, B/F or B/B0 may also be used. Specimens should be determined in duplicate, the average value is taken, and the corresponding antigen concentration is detected on the standard curve. Not suitable for the crowd People with reduced hematopoietic function such as leukemia, various anemia, myelodysplastic syndrome, or people with thrombocytopenia should pay attention to blood draw, and should not take more or more blood. Adverse reactions and risks 1. After the blood is drawn, do not press the needle hole to avoid subcutaneous hematoma. If there is a small piece of bruise in the blood, it is slightly tender, please don't panic, you can do hot compress after 24 hours to promote the absorption of blood. The general small amount of congestion will gradually absorb in 3 to 5 days and the color will become lighter and return to normal. 2. After the blood draw, symptoms such as dizziness, vertigo, fatigue, etc. should be immediately supine, drink a small amount of syrup, and then undergo a physical examination after the symptoms are relieved.