Parvathi Hosain

Measurement of plasma volume using 99Tcm, and 113Inm labelled proteins

The short-lived 132I-labelled serum albumin (HSA) has previously been used for the repeated estimations of blood volume with reduced dose of radiation. The possibilities of using 99Tcm-HSA and 113Inm-chloride (the shortlived blood-pool scanning agents) for similar measurements have been explored. Simultaneous measurements of plasma volume were carried out in human subjects using 99Tcm-HSA or 113Inm-chloride with 131I-HSA. The values obtained with the new agents were comparatively higher (about 5 per cent) than results with 131I-HSA. Studies in dogs showed that a direct slow injection of 113InmCl3 in acidic saline could be used for the measurement of plasma volume, though pre-labelling of plasma transferrin by simple mixing improved the accuracy. The method was applied in repeated estimations of blood volume within a few hours in normal women and to determine changes in blood volume after delivery in pregnant women. The relative values of whole body radiation doses per estimation of plasma volume were calc...

Quality control studies of 99mTc-labeled radiopharmaceuticals by high-performance liquid chromatography

Abstract Efficacy of HPLC in the quality control of commonly-used 99 m Tc-labeled radiopharmaceuticals has been evaluated using different columns. μ-Bondagel and μ-Bondapak columns were found to be suitable for the separation of 99 m TcO 4 − from 99 m Tc-labeled HSA and HIDA, respectively. Both of these columns offered marginal utility for DTPA, MDP and PPi.

Technetium-99m labelled imidodiphosphate: an improved bone-scanning radiopharmaceutical

Technetium-99m labelled imidodiphosphate was prepared in the presence of stannous ions. It was evaluated as a bone-scanning agent in animals and patients. Comparative tissue distribution studies in mice showed a relatively higher uptake of radioactivity in bone when 99Tcm -labelled pyrophosphate and diphosphonate. Accumulation of radioactivity in soft tissues, especially kidneys, was less with this radiopharmaceutical. Results in patients were most satisfactory in delineating skeletal bone and identifying bone lesions with relatively small tracer doses of the radiopharmaceutical.

Measurement of cardiac output with indium 113m-labelled transferrin

Abstract The use of 113Inm-transferrin has been proposed as a suitable agent for the repeated measurements of cardiac output with reduced doses of radiation. It provides certain advantages over the use of 99Tcm or 132I-HSA. Studies were carried out in anaesthetised dogs and normal human subjects. Measurements of cardiac output within short intervals with 131I-albumin and 113Inm-transferrin gave comparable results.

Comparison of biodistribution of 3H,32P and 99mTc labeled Gpp(NH)p in tumor bearing hamsters

Biodistribution and tumor uptake studies were carried out with intravenously injected tracer doses of Gpp(NH)p labeled with 3H, 32P or 99mTc . Syrian golden hamsters with cheek pouch carcinomas, induced by repeated topical applications of DMBA, were used as a tumor model. The biodistributions of these three radionuclides were different, indicating significant molecular cleavage of this nucleotide analog. It was also apparent that this compound labeled with 99mTc may not be useful for tumor imaging due to low tumor-to-blood specific activity ratio. The cheek pouch carcinoma tumor model may be valuable for the evaluation of tumor localizing radiopharmaceuticals.