Radioactive iodine

Fourth, they are difficult to measure in body fluids. There are very precise ways of measuring very small quantities, in plasma or urine, of almost all conventional medicines and this has made it possible to make the kinetic measurements we have been considering earlier. Some of the techniques for the big protein medicines are not as reliable. For example, one way of tracing a big molecule s progress through the body is to label it with a radioactive tracer. Biopharmaceuticals can be labelled with, for example, radio-iodine (Iodine-125) which can be counted in samples of plasma or urine. However as proteins are similar or identical to normal proteins they can be metabolised and the label can become part of a metabolite or another breakdown product. Counting the iodine radioactivity in this case will not be measuring the parent molecule alone. 

III.b.1.6. Radioactive iodine. Radioactive iodine (Iodine-131) is a radioactive isotope of iodine, usually taken in an oral solution formulation as sodium 1. Given orally as sodium I, radioactive iodine is rapidly absorbed, concentrated and stored in the thyroid follicles. The therapeutic effect depends on beta-ray emission and destruction of thyroid parenchyma manifests some weeks after treatment. It is relatively safe, cheap, painless and avoids side effects associated with surgery. It is widely regarded as the treatment of choice in adults with toxic multinodular goiter, toxic nodule and people who relapse after a course of antithyroid medication. 

Iodine (radioactive) Significant Enters milk in quantities sufficient to cause thyroid suppression in infant. 

Detection of the symporter protein can also take place through various means. In western blotting, proteins harvested from cells or tissues can be separated on a denaturing polyacylamide gel, transferred to membranes, and then probed with specific antibodies directed toward the symporter protein that can indicate whether the symporter was present in that specific tissue. These specific antibodies may also be utilized in a process called immunohisto-chemistry. In this method, the tissue remains whole and is sectioned into thin slices for easy study under a microscope. Treatment of this tissue with the antibody directed against the symporter then allows for the detection of the protein within the tissue slice. A final method of determining symporter expression and iodine uptake makes use of the fact that some iodine isotopes are radioactive. The location of these radioactive isotopes can be determined by using cameras that detect iodines radioactive emissions. This allows... 

Because the uptake of radioactive iodine by the thyroid is indistinguishable from ordinary iodine, radioactive iodine is trapped in thyroid cells (WiUiams, 1986). When taken up by thyroid cells, beta-emissions from radioactive... 

Carrier-free iodine, radioactive concentration 100 mCi/ml (e.g. code IMS-30. Amersham Pharmacia Biotech)... 

Operation of the main control room habitability system is automatically initiated on high-2 particulate or iodine radioactivity set point, or low pressuriser pressure, a safety related signal is generated to isolate the main control room from the nuclear island non-radioactive ventilation system and to initiate air flow from the main control room habitability system storage tanks. Isolation of the nuclear island non-radioactive ventilation system consists of closing valves in the supply and exhaust ducts that penetrate the main control room pressure boundary. Main control room habitability system airflow is initiated by a signal which opens the isolation valves in the main control room habitability system supply lines (see Section 6.4 of Reference 6.1). 

For abnormal conditions, control actions are taken at two levels of radioactivity as detected in the main control room supply air duct. The first is "high" radioactivity based upon gaseous radioactivity instrumentation. The second is "high-high" radioactivity based upon either particulate or iodine radioactivity instruments. 

If ac power is unavailable for more than 10 minutes, pressurizer pressure falls below the low setpoint, or if "high-high" particulate or iodine radioactivity is detected in the main control room supply air duct, the protection and safety monitoring system automatically isolates the main control room from the normal main control room/control support area HVAC subsystem by closing the supply, return, and toilet exhaust isolation valves. Main control room habitability is maintained by the main control room emergency habitability system, which is discussed in Section 6.4.4 of this PCSR. 

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