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Volume 19 (1978)
- Issue 4 Pages 287-
- Issue 3 Pages 175-
- Issue 2 Pages 101-
- Issue 1 Pages 62-
Volume 19, Issue 4
Displaying 1-4 of 4 articles from this issue
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T. IWASAKI, H. OHARA, S. MATSUMOTO, H. MATSUDAIRA1978 Volume 19 Issue 4 Pages 287-294
Published: December 15, 1978
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSEffects of a 5, 000 gauss magnetic field on three biological systems were investigated. (1) Chinese hamster ovary (CHO) cells, growing in a plastic flask, were exposed to the magnetic field with full of F10 complete medium for 8 hours at room temperature. After the exposure, the cells were dispersed and replated for the examination of cellular growth and multiplicity, and of colony forming ability. (2) Naturally synchronous plasmodia of Physarum polycepharum were exposed at S-G2 or M-S-G2 for 8 hours at 25°C, and examined if mitosis was delayed. (3) The fertilized or early cleavage eggs of Xenopus laevis were also exposed (up to 72 hours), and their hatchability and delay in the embryonic development were checked.
The results of the present study indicated that such short time exposure does not produce any biological disturbance in all of these three systems.View full abstractDownload PDF (344K) -
TAKU KOYANAGI, MOTOKAZU NAKAHARA, MITSUE IIMURA1978 Volume 19 Issue 4 Pages 295-305
Published: December 15, 1978
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSRetention of 54Mn, 59Fe, 60Co and 65Zn by marine demersal fish, Ishigarei (Kareius bicoloratus) was observed by administering sediment-bound radio-isotopes orally to the fishes to elucidate the contribution of sediment to the accumulation of radionuclides by marine benthic organisms.
The sediment had high distribution coefficients for these radionuclides and from the result of leaching experiments with acidified seawater, considerable fractions of radioactive Mn, Co and Zn in the sediment were assumed to be leached in the stomach of the fishes. Retention patterns of the nuclides in the whole-body of the fishes were analyzed by peeling off method and two components were obtained for all the nuclides. The parameters which which characterized the retention patterns suggested relatively high absorption efficiencies of the radionuclides except 59Fe through the digestive tract of the fishes and the retention patterns of the slower component were supposed to be similar to those observed for the nuclides taken up from seawater or food by the fishes. Rapid and higher transfer of the absorbed radionuclides to the particular organs of the fishes suggested the important role of the sediment in the radioactive contamination of marine demersal fishes.View full abstractDownload PDF (447K) -
MASAHIDE ASANO, JAMES E. NORMAN Jr, HIROO KATO, KANICHI YAGAWA1978 Volume 19 Issue 4 Pages 306-318
Published: December 15, 1978
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSThe authors examined 155 autopsy cases of Hashimoto's thyroiditis in the Life Span Study sample including both A-bomb survivors and controls in Hiroshima and Nagasaki (1954 to 1974). Hashimoto's thyroiditis was classified into lymphoid, diffuse and fibrous types and the following results were obtained.
No difference existed in the effects of A-bomb radiation in the incidence and ATB. The ratio of males to females did not reveal statistical significance, even though reversed ratio was noted in the high dose group. The variation of thyroid gland weight in T65 dose or by variant showed no significant pattern, even though the smallest average weight was found in the highest radiation exposure group. The complication in the patients with Hashimoto's thyroiditis were noted to have high prevalance of ovarian cancer and low prevalence of stomach cancer and total cancer. Only two patients with Hashimoto's thyroiditis were found to be complicated with thyroid carcinoma. Among collagen diseases, the prevalence of rheumatic fever and rheumatoid arthritis was high as complication. And the prevance of combined diseases suggested that no late effect of A-bomb radiation existed.View full abstractDownload PDF (736K) -
T. MORI, M. HORIKAWA, O. NIKAIDO, T. SUGAHARA1978 Volume 19 Issue 4 Pages 319-335
Published: December 15, 1978
Released on J-STAGE: July 14, 2006
JOURNAL FREE ACCESSTen sulfhydryl (SH) compounds including cysteamine could be divided into three classes according to their radioprotective action and toxicity as measured by colony forming ability in irradiated and unirradiated mouse L cells. Cysteamine, 2-aminoethylisothiuronium bromide hydrobromide (AET) and 2-mercaptopropionylglycine (MPG) were chosen respectively from each class and their protective abilities against the formation of single and double-strand breaks in cellular DNA induced by X-rays were tested. The X-ray-induced single and doublestrand breaks were protected effectively by cysteamine and to a lesser extent by AET, but significant radioprotective action was not observed with MPG. These results are in good agreement with those obtained for cell survival.
On the other hand, X-ray-induced single-strand breaks can be rejoined during post-irradiation incubation in SH compound-free medium. However, most of the double-strand breaks were left unrejoined even after prolonged post-irradiation incubation. These results suggest that there is a correlation between protection against cell death and protection against the formation of DNA double-strand breaks.View full abstractDownload PDF (785K)
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