Manuel Tubis

Preparation and Use of I131 Labeled Sodium Iodohippurate in Kidney Function Tests

Summary I131 labeled sodium o-iodohippurate (I131 Hippuran) has been prepared by 2 methods. This compound eliminates major disadvantages of currently used radioactive substances for individual kidney function testing. There is no complication due to liver uptake. It is more rapidly and completely removed, thereby reducing the time for test by 100% or more. Clinical studies with patients having known urinary tract pathology indicate that I131 Hippuran demonstrated comparative differences more sensitively than other labeled “renographic’ substances(5).

The preparation and properties of I131-labeled iodobenzoic acids

Methods are described for the preparation of I131-labeled ortho, meta and para iodobenzoic acids by exchange. These are suitable for biological and other uses. Their toxicity and chromatographic behavior are reported. A possible explanation is offered for the difference in the exchange of I131 for I127 in the formation of these isomers.

Accumulation of Homologous Radioiodinated Albumin in Experimental Tumors

Conclusion The data presented indicate that experimental tumors of the liver (Brown-Pearce) in rabbits accumulate more radio-iodinated rabbit albumin than normal liver tissue of the same animal. This increased concentration appears to be unrelated to vascularity since it was demonstrated in perfused animals.

Indium-III-Labeled Antibody Heavy Metal Chelate Conjugates: A Potential Alternative to Radioiodination

Summary An alternative method to radioiodination is outlined for labeling antibodies with a radioactive marker. The method requires the conjugation of the antibody molecule to chelating agents that contain a free amino group and are capable of binding heavy metal ions. Glutaraldehyde is the coupling agent used to bridge the free amino groups on both the chelate and the antibody molecules. 111In is then added to the antibody-chelate conjugate and is bound instantaneously by the chelating portion. Electrophoretic, autoradiographic, immunodiffusion, and hemagglutination techniques were used to confirm the integrity of the 111In-labeled antibodies.

Cholescintigraphy with 99mTc-Penicillamine

D-pencillamine labeled with 99mTc (Tc-Pen) was used for cholescintigraphy in dogs and man. Satisfactory images of the gallbladder were obtained using a scintillation camera fitted with a pinhole collimator. The results of cholescintigraphy and contrast cholecystography compared favorably. The authors suggest that Tc-Pen is taken up by the hepatocytes and excreted into the bile canaliculi which enter the gallbladder. Tc-Pen may prove to be an ideal agent for evaluation of hepatocellular function.