RADIOISOTOPES

Research has been done on optically reconstructed imaging employing the Multiple Pinhole Coded Aperture (hereafter abbreviated as MPCA) in radioisotope tomographic imaging. However, problems remain in the optically reconstructed image method. Therefore, we em-ployed a minicomputer (hereafter abbreviated as CPU) and developed the software for decoding and managing the radioisotope tomographic image. Combining the MPCA and the CPU system, we were able to decode and manage the radioisotope tomo graphic image.
1) In comparison to the optically decoded MPCA image, various input commands are possibly in the CPU method according to the dialogue between the CPU and the on line typewriter. In addition to this, decoded tomo graphic images of unrestricted depth are readily attainable.
2) In the CPU method noise elimination and other aspects of image management can be easily performed.

View full abstract

Metabolism of 3'-methyl-4- (methylamino) azobenzene (3'-Me-MAB) in the rat has been investigated by an ion cluster technique. A mixture of non-labeled and deuterium labeled 3'-Me-MAB in cottonseed oil was administered orally with a stomach tube. After administration, the rat bile was collected for 24 hr and enzymically hydrolyzed. This sample was applied to an Amberlite XAD-2 column and the column was washed with water. The metabolites were eluted with methanol and were separated by thin-layer chromatography. The mass spectrum of each metabolite was measured. By means of this technique, the metabolites oxidized at the 3'-methyl group were newly detected in the bile in addition to the N-demethylated, aryl hy-droxylated, and their azo-reduced metabolites. The effect of the ring methyl group on the carcinogenic action of aminoazo dyes is also discussed.

View full abstract

Show abstractHide abstract

The metabolic fate of the labeled glucose (U-¹⁴C) was studied during the feeding with 3'-methyl-4- (dimethylamino) azobenzene (3'-Me-DAB) in rats by the method of radiorespirometry. The peak time (PT) was inclined to hasten from 2nd, reached to the maximum at 4th, and markedly returned to delay at 5th week after the administration of 3'-Me-DAB. The peak height (PH) at 4th to 5th week was lower than that of control. These alterations coincided with the appearance of a-fetoprotein (AFP) at an early stage. However, no marked changes were found in the yield value (YV) .
The activities of glycolytic enzyme were assayed continuously for 6 weeks after the administration of 3'-Me-DAB. As the result, only hexokinase was activated at 4th week, while pyruvate kinase was inhibited to the level of about 30% of control immediately after the onset of 3'-Me-DAB up to 5th week.
Changes of radiorespirometric parameter and enzyme activity were compared on normal and tumor bearing rats. These results were significantly different from those which obtained at an early stage, 1st to 6th week, after the administration of 3'-Me-DAB. Namely, the haste of PT observed at 4th week was not found in tumor bearing rats. On the other hand, the activity of hexokinase was slightly decreased in tumor bearing rats, while the activity of pyruvate kinase was about 2 times as high as that of normal rats.

View full abstract

Download PDF (642K)

1) The experimental studies have demonstrated that ^99mTc-gluconate reaches a high concentration in the kidneys within 1-2 hours after injection and its concentration in organs adjacent to the kidneys is low.
2) The initial images of serial macroautoradio grams visualized the inner medulla as well as the cortex and outex medulla, whereas the delayed images revealed only the outer cortex and outer stripes in the outer medulla. These findings suggest that this renal agent consists of two components and the delayed component deposits in the convoluted and straight segments of proximal tuble.
3) This renal agent visualizes the calyceal system and excretory pathways in the initial study and the renal morphology in the delayed study. Therefore, using this renal agent, it may be possible to evaluate a variety of renal diseases, including obstructive uropathy, space-occupying lesions, congenital deformities, etc, .

View full abstract

Register with J-STAGE for free!