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Volume 38 (1997)
- Issue 4 Pages 213-
- Issue 3 Pages 153-
- Issue 2 Pages 77-
- Issue 1 Pages 1-
Volume 38, Issue 4
Displaying 1-4 of 4 articles from this issue
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TADAAKI BAN-NAI, YASUYUKI MURAMATSU, SATOSHI YOSHIDA, SHIGEO UCHIDA, S ...1997 Volume 38 Issue 4 Pages 213-218
Published: 1997
Released on J-STAGE: April 06, 2006
JOURNAL FREE ACCESSWe used the multitracer technique to study the transfer of several radionuclides to two mushroom species. Radionuclides accumulated in the fruiting bodies of the mushrooms in the order of 83Rb > 65Zn > 54Mn > 22Na > 75Se and 85Sr > 60Co > 88Y, 102Rh, 139Ce 143, 144Pm 146, 153Gd and 173Lu > 175Hf. The concentration ratio values for 83Rb, 65Zn and 54Mn in the fruiting bodies were more than 10, whereas those for 60Co, 88Y, 102Rh, 121mTe, 175Hf and the rare earth elements were less than 1. There were major differences in the accumulations of the alkali elements.View full abstractDownload PDF (286K) -
NOBUHIKO BAN, MICHIAKI KAI, TOMOKO KUSAMA1997 Volume 38 Issue 4 Pages 219-231
Published: 1997
Released on J-STAGE: April 06, 2006
JOURNAL FREE ACCESSMurine acute myeloid leukemia is characterized by chromosome 2 aberrations, and genesis of the marker chromosome 2 by radiation is suspected to be an initiating event of radiation leukemogenesis. A detailed analysis of the type and frequency of chromosome 2 aberrations in murine bone marrow cells at an early stage after irradiation is provided here. A total of 40 male C3H/He mice was exposed to 137Cs γ-ray at a dose of 1, 2 or 3 Gy, and sacrificed 24 hours after irradiation. Metaphase samples prepared from bone marrow cells were Q-banded for karyotyping or painted with DNA probes specific to chromosome 2. In 5 mice analyzed by karyotyping, one mouse showed high frequency of the marker aberrations as well as other chromosome 2 aberrations. Chromosome painting analysis for the rest of the mice also detected 3 animals showing significantly high frequencies of chromosome 2 aberrations. Dose-dependence of the frequencies was observed even among those mice that tended to be sensitive. The results indicated that there was a subgroup of mice carrying hypersensitive chromosome 2. The subgroup could be leukemia-sensitive if radiation-induced chromosome aberrations are responsible for an early change in myeloid leukemogenesis.View full abstractDownload PDF (586K) -
YOSHIHIRO TAKAI, YOSIO HOSOI, KIYOHIKO SAKAMOTO, SIGEFUMI OKADA1997 Volume 38 Issue 4 Pages 233-240
Published: 1997
Released on J-STAGE: April 06, 2006
JOURNAL FREE ACCESSCorrelations between radiocurability and kinetic parameters were investigated in four transplantable tumor types in WHT/Ht mice. The radiation dose to achieve 50% tumor control at 120 days after irradiation, i.e., TCD50/120, was 30 Gy for squamous cell carcinoma H, 32 Gy for squamous cell carcinoma NOS, 46 Gy for rhabdomyosarcoma KAS, and 63 Gy for fibrosarcoma YAS. The tumor cell kinetic parameters investigated were specific growth delay, volume doubling time, 125I -iododeoxyuridine (IUdR) uptake rate, and specific cell loss rate. The specific cell loss rate was defined as the ratio of cell loss rate in non-irradiated tumors to the rate in irradiated tumors, and was obtained by measuring the retention rate of radioactivity in the tumors. No correlations were found between specific growth delay, volume doubling time, 125I-IUdR uptake rate, and TCD50. However, the specific cell loss rate correlated with the TCD50. Therefore, the 125I-IUdR labeling method may be useful as an in situ predictive assay for tumor radiocurabilityView full abstractDownload PDF (353K) -
CHARLES E. SWENBERG, YASHESH N. VAISHNAV, BIN LI, HONG TSAO, BING MAO, ...1997 Volume 38 Issue 4 Pages 241-254
Published: 1997
Released on J-STAGE: April 06, 2006
JOURNAL FREE ACCESSThe technique of high-resolution gel electrophoresis using oligodeoxyribonucleotides of known composition as model systems, offers a simple quantitative estimate of DNA damage in aqueous solution induced by ionizing radiation. The fraction of damaged DNA can be quantitatively defined in terms of the increased electrophoretic mobilities of the damaged oligonucleotides, relative to the mobility of the unirradiated and intact oligonucleotides. The usual direct strand breaks can be observed at γ-ray dosages of 200 Gy. However, at a γ-ray dosage of 400 Gy, only a broad background, attributed to heterogeneously and multiply damaged oligonucleotide fragments with overlapping and varying electrophoretic mobilities, can be distinguished. On the other hand, individual bands due to resolvable DNA fragments are evident even at dosages as high as 400 Gy for fission neutrons. When double-stranded oligonucleotides are exposed to γ-ray dosages of 200 Gy, the fraction of damaged DNA approaches 30-40%. This damage can be almost completely suppressed (> 99%) if the irradiations are conducted in aqueous solutions in the presence of 0.5-1.0 mM concentrations of the thiols cysteamine or 3-(3-methylaminopropylamino)propanethiol (WR-151326). The rate constant of reaction of OH· radicals with small double stranded oligonucleotides 16 base pairs long, KDNA, is found to be closer to the diffusion-controlled value (> 3 × 109 M-1 s-1) than the magnitudes of KDNA for the higher molecular weight, native DNA reported in the literature. These observations suggest that oligonucleotides represent more simple model systems than native DNA in solutions for studying the mechanisms of radioprotection exerted by thiols of different structures.View full abstractDownload PDF (647K)
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