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Biomedical subjects

R D Ganatra

Publications and source records attributed to R D Ganatra.

At least 55 records · Page 3Linked to original sources

Labeling of red blood cells with Tc-99m after oral administration of SnCl2: concise communication.

In vivo labeling of red blood cells with Tc-99m was possible after prior oral administration of SnCl2, both in rats and human volunteers. Absorption of oral SnCl2 was low but sufficient for more than 95% labeling efficiency. Prior i.v. administration of stannous chloride is known to induce in vivo labeling of red blood cells with pertechnetate. We have observed that such labeling is possible even after oral administration of stannous chloride. Nearly 95% of the circulating radioactivity and 93.7% of the administered radioactivity was in RBCs 30 min after i.v. injection of 99mTcO4- in rats that were fed 5 mg of stannous chloride (3.13 mg Sn2+ ion) 2 hr before injection. Red blood cells from four human volunteers could bind pertechnetate, both in vitro and in vivo, after oral administration of 100 mg of SnCl2. We have obtained a blood-pool image of the human heart by labeling the RBCs in vivo by this method. We have also studied various parameters affecting the in vivo binding of RBCs with Tc-99m--such as the amount of orally administered SnCl2, the time of injection of radionuclide after oral SnCl2, and the optimum time for the imaging.

Administration, Oral↗

Transit time of a radionuclide bolus through inferior vena cava.

The effect of an intrinsic block or extrinsic pressure on blood flow through the inferior vena cava (IVC) was studied after rapid injection of 99mTc-pertechnetate or 99mTc-phytate into the femoral vein. Peak-to-peak transit time (PTT) between the curves generated at IVC origin and over the cardiac blood pool was measured in twelve normal patients (PTT = 2.0 +/- 0.7 s) and six patients clinically suspected of circulatory impediment through the IVC (PTT = 3.0 to 30.0 s). PTT measurements augmented the information obtained from sequential scintiphotos of IVC circulation. It is felt that this may be a more objective parameter for follow-up of patients having a progressive, primary disease of this vessel.

Blood Circulation↗

Factors affecting the preparation of 99mTc-sulfur colloid.

Some factors, such as the effect of mannitol as 'stabilizer', increased concentration of thiosulfate, autoclaving conditions, etc., that can affect the preparation of 99mTc-sulfur colloid and consequently its biodistribution into different tissues are discussed. Also discussed are parameters, such as distribution with respect to time, effect of storage, preloading dose, etc., that can influence the uptake of the radiopharmaceutical by the RES in animals and humans.

Animals↗

Efficacy of brain scanning in epilepsy of late onset.

Brain scans of 513 patients with epilepsy of late onset were analysed with reference to the patient's age and sex and to the nature of convulsion. Only 17 of them showed an abnormal concentration of radionuclide indicating a space-occupying lesion in the brain. The findings of those patients who had positive brain scans were correlated with EEG findings. It was found that the incidence of epilepsy of late onset is almost 3 times higher in males than in females and that the age cannot be considered as a criterion for screening the patients for brain scan investigations as far as epilepsy of late onset is concerned. In our opinion, the incidence of 3.3% is not too low. A positive brain scan finding calls for further investigation and helps in deciding the management and further line of treatment of the patients. Moreover, a normal scan rules out the presence of a space-occupying lesion and helps as a screening procedure.

Adult↗