A novel approach for the adsorption of iodine-125 on silver wire as matrix for brachytherapy source for the treatment of eye and prostate cancer.

The adsorption of iodine-125 on silver wire bits coated with palladium to be sealed in titanium capsules as brachytherapy sources was studied. A method was optimized to obtain quantitative adsorption of 125I on the palladium treated silver wires. A comparative evaluation of palladium coated and uncoated (bare) silver wires on the adsorption of 125I was made. While, the adsorption of bare silver wires showed low, inconsistent uptake (approximately 60%) of 125I with high leachability (approximately 4%), the Pd coated silver wires showed quantitative and consistent uptake of 125I (approximately 90%) and exhibited low leachability (0.01%). 125I adsorbed on Pd coated silver wires could be used as a matrix for the preparation of interstitial sources in eye and prostate cancer therapy.

Superiority of the use of a pre-incubated complex of primary and second antibody in the radioimmunoassay of thyroid hormones.

We report on the superiority of a radioimmunoassay (RIA) system wherein the second antibody (Ab2) is incorporated as a pre-incubated complex with the primary antibody (Ab1) for the assay of haptens like triiodothyronine (T3) and thyroxine (T4). Separation of the antibody bound and free antigen (Ag) was accomplished by 8% polyethylene glycol (PEG) (final concentration) following a single incubation of less than 1 h. The other advantages of this system are a 15-fold reduction in the quantity of Ab2 (without any need for increasing the concentration of PEG) and the consequent savings in cost.