Satoshi Fukuda, Haruzo Iida, Yuyuan Hseih¡ö and Wenzhi Chen¡ö (¡öShanghai Institute of Materia Medica)
- Keywords:
oral administration, CBMIDA, plutonium, Zn-DTPA
¡¡The effects of the oral administration of CBMIDA [catechol-3,6-bis(methyleiminodiacetic acid)], given in drinking water, on the removal of plutonium in rats were compared to those of Zn-DTPA. Male Wistar rats received a daily dose of 120 ¦Ìmol¡¿kg or 1,200 ¦Ìmol¡¿kg of CBMIDA or Zn-DTPA, given in drinking water, for 4 weeks after plutonium injection. The content of plutonium in bone, liver, kidney, spleen, and testis was measured by liquid scintillation spectrometry after treatment of the organs by a wet ash method. The plutonium content of each organ in the 120 ¦Ìmol¡¿kg groups of CBMIDA and Zn-DTPA was not significantly reduced compared to the control. The content of plutonium in the 1,200 ¦Ìmol¡¿kg groups of both CBMIDA and Zn-DTPA was, however, significantly reduced, to 65.7¡ó (p¡ã0.001) and 76.8 ¡ó (p¡ã0.05), respectively of the control in bone, and to 66.6 ¡ó (p¡ã0.05) and 44.0 ¡ó (p¡ã0.01), respectively, in liver. There were no significant decreases in kidney, spleen, and testis in the 1,200¦Ìmol¡¿kg dose CBMIDA group, but there were significant decrease in these organs in the 1,200¦Ìmol¡¿kg dose Zn-DTPA group. These results showed that, when given orally, CBMIDA was more than effective in removing plutonium from bone than Zn-DTPA, a finding similar to the results achieved with the intravenous injection of both agents in our previous study.
[Publications] Fukuda, S., Iida, H., Hseih, Y. and Chen, W.: J. Health Phys., 30, 117-120, 1995.
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2.Correlation between Cell Death and Induction of Non-rejoining Chromatin Breaks by X-rays and Carbon-Ion Beams
Masao Suzuki, Yoko Kase, Tatsuaki Kanai and Koichi Ando
- Keywords:
non-rejoining chromatin break, PCC, carbon-ion beams, LET
¡¡We reported that the induction rate of the initially measured chromatin breaks per cell per Gy, which were obtained by counting the number of chromatin fragmentations detected by the premature chromosome condensation (PCC) technique, on normal human fibroblast cells was almost constant, but that the number of remaining breaks after 12h of post-irradiation incubation differed with the LET between 0.3keV¡¿¦Ìm and 230keV¡¿¦Ìm for 137Cs gamma-rays and carbon-ion beams. This LET dependence of non-rejoining chromatin breaks was the same as the LET dependence of cell death.
¡¡In order to clarify the relationship between the radiosensitivity and the induction of non-rejoining chromatin breaks by qualitatively different types of radiation on different radiosensitive human cell lines, we examined the correlation between the cell death and the induction of non-rejoining chromatin breaks on normal human cells and human tumor cell lines by using X-rays and carbon-ion beams accelerated by the HIMAC.
¡¡The RBE values of cell death by carbon-ion beams relative to X-rays were 1.1 to 1.4 for 13 keV¡¿¦Ìm beams and 2.5 to 2.9 for 77 keV¡¿¦Ìm beams. The induction rate of non-rejoining chromatin breaks per cell per Gy was the highest for 77 keV¡¿¦Ìm beams on all of the cell lines. The results concerning the relationship between cell death and non-rejoining chromatin breaks indicated that the cell line which was more sensitive to cell death had higher induction of non-rejoining chromatin breaks. These results suggest that there was a good correlation between the cell death and the induction of non-rejoining chromatin breaks on various cell lines.
¡¡We have now begun to examine use of the PCC technique for predictive assay in cancer radiotherapy.
[Publications] Suzuki, M., Watanabe, M., Kanai, T., Kase, Y., Yatagai, F., Kato, T and Matsubara, S.: Advances in Space Research, 18, (1¡¿2)127-(1¡¿2)136, 1996.
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