Radioactive sodium iodide

Sodium Iodide, Radioactive, Sodium iodide—,MI sodium radio-iodide (tslI) Na l iodotope Oriodide Radiocaps-131 Theriodide-131. Prepd from radioactive iodine ( l) which has a half-life of 8 days and emits beta and gamma rays. Other properties identical with those of ordinary sodium iodide. Dispensed as carrier-free sodium radioiodide in capeules for oral use Or in aq soln for oral or parenteral administration. 

Radioisotope scanning was used in the early days to detect filling defects in organs, such as the liver and spleen. Radioactive sodium iodide was used to image the thyroid. Radioactive particles were used to image the reticuloendothelial system. The dye, radio-iodinated Rose Bengal, was used to image the liver. 

Molecular imaging as the foundation of diagnosis is not new. Half a century ago, imaging the rate of accumulation of radioactive sodium iodide by the thyroid was the first example of molecular imaging, although it was called radioisotope scanning. 

For the experiment with radioactive iodine, three kinds of radioactive solutions were prepared by spiking with radioactive sodium iodide- I solution (aqua, KI (5 g/100 ml) and 0.15M I2). The specific radioactivity of the radioiodine added was so high that its weight was negligible. The activities of the solutions were adjusted to about 2 X 10 cpm/ml, each 15 ml of radioactive solution was mixed with the sample and after standing for 1 h, the activity of the supernatant liquid was measured with a Aloka Auto Well ARC-500. 

Fig. 2. Distribution of radioactive iodiiie of the injected labeled enzyme derived from the preputial gland in rat. Radioactive sodium iodide dissolved in saline was given to another rat as contrast. Shaded bar injection of incn anic radioactive iodide black bar labeled enzyme injection. Total recovered radioactiviUes in rat body are expressed as 100%.

In a classic expenment Edward Hughes (a colleague of Ingold s at University College Lon don) studied the rate of racemization of 2 lodooctane by sodium iodide in acetone and compared It with the rate of incorporation of radioactive iodine into 2 lodooctane... 

The displacement was monitored by observing the changing distribution of radioactive 128I between the inorganic (sodium) iodide and 2-iodooctane, and it was found, under these conditions, to be second order overall (first order with respect to 128Ie and to 2-iodooctane) with k2 = 3-00 + 0-25 x 10-5 (at 30°). 

EGER targeting was also used for systemic delivery of pDNA expressing the sodium iodide symporter (NIS) gene to liver cancer cells, followed by administration of radioactive isotope iodine-131, which accumulates in the tumor by NIS-mediated uptake in radiotherapeutic doses [227]. 

Sodium iodide is an iodine supplement in food, an expectorant, cloud seed to cause rain, and solubilizes iodine in aqueous solution for analytical work. The radioactive iodide salt of sodium, Na(I-131) is used to diagnose thyroid function. 

Gamma-ray counters are usually made from a cylinder of activated sodium iodide, which is enclosed in an aluminum shell, with one side of the cylinder lying in close proximity to a photomultiplier tube. The flow cell is composed of a U tube or coil (Figure 7.12) placed into the core of the cylinder. Radioactivity present in the column effluent is blocked from escaping by the dense sodium iodide, and the energy is converted into light, which is measured by the photomultiplier tube. 

Radioactive iodine (131I) sodium (Iodotope, Sodium Iodide I 131 Therapeutic)... 

In a technique known as medical imaging, tracers are used in medicine for the diagnosis of internal disorders. Small amounts of a radioactive material, such as sodium iodide, Nal, which contains the radioactive isotope iodine-131, are administered to a patient and traced through the body with a radiation detector. The result, shown in Figure 4.11, is an image that shows how the material is distributed in the body. This technique works because the path the tracer material takes is influenced only by its physical and chemical properties, not by its radioactivity. The tracer may be introduced alone or along with some other chemical, known as a carrier compound, that helps target the isotope to a particular type of tissue in the body. 

The expts were conducted in stainless steel sigma-blade type mixers with proplnt mixing capacities of 60, 600 and 2000 lbs, respectively. Radioactivity measurements on samples taken from various locations in the batch at different mixing times were performed with a sodium iodide scintillation detector system... 

Exchange Reactions of Iodine. Iodine dissolved in ethyl iodide does not exchange with the iodine of the ethyl iodide at room temperature, but there is an exchange between radioactive iodide ion and ethyl iodide as shown by experiments with sodium iodide and ethyl iodide dissolved in alcohol. 

Aliphatic Substitution and the Walden Inversion. The rate of substitution of radioactive iodine into sec-octyl iodide in acetone was found to be the same as the rate of racemization of d-sec-octyl iodide by sodium iodide. The radioactive iodine was produced by bombardment with neutrons from 150 millicuries of radon mixed with beryllium and embedded in paraffin. 

The tren-based heteroditopic receptor 22, featuring a tripodal tetrahedral amide hydrogen-bond anion-recognition site in combination with benzo-15-crown-5 ether cation-binding moieties, has been found to cooperatively bind chloride, iodide, and perrhenate anions via co-bound crown ether-complexed sodium cations. It also can efficiently extract the radioactive sodium pertechnetate from simulated aqueous nuclear waste streams. The anion-binding affinity of 22 is considerably reduced in the absence of a co-bound cation <1999CC1253>... 

While increasing anion solvation by protic solvents has an accelerating effect on SnI reactions as described above, it is often a decelerating factor in Sn2 reactions. Thus, reaction (5-103) between (iodomethyl)benzene and radioactively labeled sodium iodide in acetone is clearly decelerated by the addition of protic solvents such as water, ethanol or phenol, as demonstrated in Fig. 5-16 [266]. 

Sodium iodide and chloramine-T can be used for the production of iodides, a process that has particular application to the introduction of radioactive iodine. ... 

Fluorescent materials have important applications in medical research. Dyes such as fluorescein are attached to protein molecules to probe biological reactions. Fluorescent materials, such as sodium iodide and zinc sulfide, can be activated by radioactivity and are used in scintillation counters to measure radiation (see Chapter 17). 

Waltz F, Pillette L, Ambroise Y (2010) Anon-radioactive iodide uptake assay for sodium iodide symporter function. Anal Biochem 396(1/91-95... 

---