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Radiotherapy for malignant pelvic disease is often followed by acute radiation colitis (ARC). It has been reported that sucralfate treatment has a protective effect against ARC, though the mechanisms of action are unknown. The effects of sucralfate on X-ray radiation-induced apoptosis was studied at 4 Gy in the colonic crypt cells of rats. Sucralfate enemas given prior to radiation resulted in the following: (1) reduction in number of apoptotic colonic crypt cells; (2) reduction in number of caspase-3 positive cells; (3) decreases in p53 accumulation and p21 expression; (4) decreases of Bax/Bcl-2 ratio. The protective effects of sucralfate against ARC may be partially due to the suppression of radiation-induced apoptosis by way of p53 in the colon and the protection of the colonic epithelial stem cell region., Journal of radiation research. 2006, 47(1), p.1-8

To determine the possible effect of hypergravity to modify the signal transduction of ionizing radiation, we analyzed the accumulation of p53 and the expression of p53-dependent genes, Waf-1 and Bax, using the western blot analysis. Hypergravity (20 × g) induced the accumulation of p53 in the human glioblastoma cell line A172 after 3 h of incubation. Low-dose (0.5 Gy) irradiation to the cells accumulated p53 1.5 h after irradiation, and induced Waf-1 and Bax. Under the condition of hypergravity (20 × g), the peak of p53 accumulation was shifted from 1.5 h to 3 h after irradiation, and the inductions of Waf-1 and Bax were suppressed entirely. These results indicate that hypergravity modifies the signal transduction of ionizing radiation through p53 in the cells., Journal of radiation research. 2002, 43(Supplement), p.261-264

60 Co / Specific activity / Atomic bomb / DS86 / Neutrons Residual 60 Co activity in five steel samples induced by neutrons from the Nagasaki atomic bomb has been measured within about 1000 m from the hypocenter. The chemical separation of cobalt and nickel from steel samples was performed, and cobalt-enriched samples were prepared for all samples. Gamma-ray measurements were carried out with a low-background well-type germanium detector. The gamma-ray spectra for five samples were compared with the spectrum of a control sample to ensure that the observed 60 Co was actually induced by A-bomb neutrons. The activation of cobalt by environmental neutrons was also investigated. It has been shown that the present 60 Co data are consistent with earlier Hashizume’s data.

We have constructed an in vitro system to examine how p53 mutants affect radiosensitivity. Mutations of p53 were made using in vitro mutagenesis, and mutant cDNAs were introduced into the human osteosarcoma cell line, Saos-2, which is devoid of endogenous p53. For wild type p5 both the expression plasmid and a regulation plasmid (LacSwitch system) were transfected into the cells. The radiosensitivities of clones of mutant p53 and wild type p53 were examined. Transformants of wild type p53 had increased radiosensitivity. The induction of wild type p53 protein by addition of IPTG did not significantly increase radiosensitivity. A mutation at codon 123 also increased radiosensitivity. Mutations at codons 143, 175, and 273 did not alter radiosensitivity., Journal of radiation research. 1998, 39(2), p.111-118

Among a total of 65, 268 Nagasaki atomic bomb survivors recorded in the Scientific Data Center of Atomic Bomb Disaster, Nagasaki University School of Medicine, 140 cases with skin cancer were collected from 31 hospitals in Nagasaki City from 1961 through 1987. Subsequently, these cases of skin cancer in Nagasaki atomic bomb survivors were statistically analyzed in relation to the estimated distance from the hypocenter by age, sex, histology and latent period. The results were as follows: 1. A high correlation was observed between the incidence of skin cancer and the distance from the hypocenter. 2. The incidence of skin cancer in Nagasaki atomic bomb survivors now appears to be increasing in relation to exposure distance. 3. Among 140 cases, basal cell epithelioma was observed in 67 cases (47. 9%) and squamous cell carcinoma in 43 cases (30. 7%)., Journal of radiation research. 1990, 31(3), p.280-287

We investigated the p53 signaling pathway induced by hypergravity in the human glioblastoma cell line A 172. Hypergravity (20×g) induced the accumulation of p53 and the phosphorylation of p53 at Ser-15. The phosphorylation of p53 with hypergravity was not inhibited by wortmannin, the PI3-kinase inhibitor. This indicated that the p53 signal pathway induced by hypergravity is different from other p53 signal pathways, such as that of the DNA damage signal. Hypergravity did not induce an expression of the genes Waf-1 or Bax, located downstream from p53. We also examined the expression of genes with hypergravity by using a DNA microarray containing oligo DNA from 30,000 human genes. Hypergravity (20×g, 6h) did induce the expression of some genes concerned with the cell signaling pathway and cytoskeleton of the cell, but not any of the p53-downstream genes. DNA microarray revealed the induction of many genes to enable the cells to adapt to the hypergravity environment., Journal of radiation research. 2004, 45(3), p.399-403