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研究グループは、宇宙放射線による生物への影響を定量的に測定し、物理学的線量計による予測値と生物学的測定値がほぼ一致することを明らかにしました。今回、研究グループは、放射線に対する感受性を高めたマウス胚性幹細胞(ES細胞)を凍結し、2013年3月にSpace X-2のドラゴン宇宙船によりISSに打ち上げて1,584日間MELFIと呼ばれる-95℃の冷凍庫に保管させて宇宙放射線を被ばくさせました。その後、約1年ごとに4回にわたって細胞を地上に回収し染色体異常等を解析するとともに地上での加速器による陽子線の影響と比較しました。その結果、ISSの冷凍庫内で測定した物理学的線量から予測された宇宙放射線の影響の強さ(線質係数)は、陽子線の1.48倍になりました。一方、ISS内で宇宙放射線が細胞に直接与えた影響(染色体異常)は陽子線の1.54倍であることから、両方の値がほぼ一致することを世界で初めて示すことができました。このことから、宇宙放射線は、未知の複合的な効果で生物学的影響が非常に大きくなる、あるいは小さくなる可能性は低く、物理学的な測定と推定によるリスク評価が信用できることが示されました。本研究成果は、今後、月や火星など、より強い宇宙放射線の影響が予想される深宇宙空間における有人長期滞在の安全につながることが期待されます。, Nowadays, ordinary people can travel in space, and the possibility of extended durations in an environment such as moon of the Earth and Mars with higher space radiation exposures compared to past missions, is increasing. Until now, the physical doses of space radiation have been measured, but measurement of direct biological effects has been hampered by its low dose and low dose-rate effect. ...

Radiation (gamma-rays and neutron) induced morphological and functional damage, mutations and change of gene expression in the human thyroid tissues maintained in improved SCID (Severe Combined Immunodeficient) mice. Microsatellite mutation and leukemia were first detected significantly in F(sub 1) progeny of N5 male mice exposed to 0.4 Gy of fission neutron., 資料番号: AA0063349085

第62回応用物理学会春季学術講演会(2015年3月11日-14日. 東海大学湘南キャンパス), 平塚市, 神奈川県, 資料番号: AC1500090000, レポート番号: 11p-A19-2

Extremely huge solar storms happened from 19 October to 6 November 2003. It affected some satellite operation and some satellite was killed by this event. Surveyed were satellite anomalies and preparations and action for satellite during this event. This information will contribute to the satellite design and operation in the future. Also sent were Satellite Environment Alert messages to some users in this period. Presented are the survey results and the release status of the Satellite Environment Alert messages., 資料番号: AA0048057031, レポート番号: JAXA-RM-04-010

For estimating the genetic effects of space radiation, an effort has been made to establish the methodology for detecting the influences of low-dose ionizing radiation at chromosome level. Human lymphoblastoid cell TK6-20C was irradiated with 10 cGy of X-rays or C-ions and mutation frequency (MF) at the heterozygous thymidine kinase (TK) locus was determined by judgment of TFT resistance. Although an increase in MF from 5.7 x 10(exp -6) to 6.9 x 10(exp -6) by X-ray irradiation was not statistically significant, C-ion exposure increased MF to 17.9 x 10(exp -6), about 3-fold induction over background level. This induction was due to the enhancement of TK mutants exhibiting hemizygous-type LOH (loss of heterozygosity). Surprisingly the radiation-specific LOH patterns were observed in more than half of these hemizygous-type LOH events. Such LOH mutants can be considered as a result of end-joining repair of DNA double-strand breaks (DSB). Recently the restriction enzyme site I-SceI was introduced into the thymidine kinase (tk) gene of human lymphoblastoid cell line TK6 and a system was established to investigate the fate of DSBs quantitatively and qualitatively at molecular level. In this proceeding, it is reported that the results of fate of site-directed DSB are well consistent with the above molecular analysis for LOH mutants obtained after low-dose ionizing radiation exposure. Here, also proposed is the analysis by introducing I-SceI site into the TK locus of the cells returned from International Space Station (ISS) and detecting whether the fate of DSBS can be modified by the stay in ISS. In other words, such long stay can be considered as priming effect in the adaptive response., 資料番号: AA0046917027

宇宙環境での長期滞在は人類がこれまでに経験したことのない様々な線質の宇宙放射線を低線量率で被曝し続けることになる。宇宙放射線の生物影響は、低線量、低線量率、逆線量率効果、長期被曝、高エネルギー粒子線、バイスタンダー効果、微小重力の影響など考慮しなければならない因子が複雑に絡みあっている。国際宇宙ステーションの内部での被曝は1日あたり約1mSvと概算されている。宇宙で生活するためには宇宙放射線の生物影響を「正しく」把握し、障害を減らすための防護策が求められる。がん抑制遺伝子p53の形質発現が放射線に照射された後に誘導され、がんにならないようにするしくみを体は備えている。果たして、宇宙環境でもその機能を発揮することができるのであろうか。放射線影響を研究する研究者に課せられた大きな課題である。, 資料番号: AA0046917028

Possible formation and alteration of bioorganic compounds in interstellar space by cosmic radiation and UV were examined. Precursors of a wide variety of amino acids and nucleic acid bases were formed from simulated interstellar media such as a mixture of CO, NH3 and H2O. When the precursors of amino acids were irradiated with circular polarized light, enantiomeric excesses of alanine was observed. These results strongly suggest that bioorganic compounds formed in interstellar space were important for the emergence of life on the earth. It is quite important to verify the formation of organic compounds in actual space environments., 資料番号: AA0045438017

SATテクノロジー・ショーケース 2014 (2014年1月24日. つくば国際会議場), つくば市, 茨城, 資料番号: PA1410072000

We investigated the lethal and mutageneic effects of cosmic radiation on silkworm eggs, using the Radiation Monitoring Container and Dosimeter in the Russian space station "Mir" as part of the first MIR utilization space experiment. In hatching and pupation, there was difference in survival rate between the launched eggs and the eggs on the earth. But, in emergence, there was no difference in it between them. In order to detect the mutation frequency, we used the specific locus method using the egg-color gene pe and re located on the fifth chromosome. The mutation frequency was 12.4 × 10-3 in space, as compared with controls, it was very high. We think that the cause is the effect of cosmic rays and micro gravity.

During space flights, crew members are constantly exposed to space radiation. Such radiation damages the cellular DNA, and may induce mutations in germ cells. Medaka (Oryzias latipes) is a useful experimental fish and precise system to measure germ cell mutation induction by specific locus test was established and found that the spontaneous and gamma-ray induced mutation rates are very similar to those of mice. We are developing novel assay systems which can detect the germinal mutation using sperm genome. The point variation and frame shift variation will be detected by the high throughput SNPs (Single Nucleotide Polymorphisms) detection system. And the transgenic strains with visible fluorescent marker expressed in sperm can detect deletion-type mutations. These systems will enable a better assessment of the late genetic risk for humans in space and, in the long-term, will contribute to optimize radiation shielding for future space exploration missions., 資料番号: AA0063349084

We have studied biological effects in normal human fibroblasts induced by low-fluence high-LET (Linear Energy Transfer) ions to examine what kinds of radiation species induce genomic instability. Cells were pre-treated with low-fluence ions (approximately 1 milli-Gy/7 to 8 h) of either carbon or helium before following irradiation with X-ray challenging dose (1.5 Gy). There observed no difference in cell-killing effect in pre-treatment with either carbon or helium, when comparing to the pre-treatment with low-dose Cs-137 gamma rays. In mutation induction there was no difference in induced mutation frequency at 1.5 Gy of X-ray challenging dose between un-pretreated and gamma-ray pre-treated cells. On the other hand, it was around 4.0 times higher in carbon-ion pre-treated cells and 1.9 times higher in helium-ion pre-treated cells than in un-pretreated cells. There is evidence that genomic instability in mutation induction induced by the pre-treatment of low-fluence ions depends upon both LET and ion species., 資料番号: AA0063349086

担当教員:喜多 和子･他, 平成25年度(2013)教養コアF(いのちと科学),授業コード:G14F21101

宇宙放射線および微小重力が、一生の間に細胞形態および細胞分化に与える影響を調べるために、細胞性粘菌Dictyostelium discoideumの2つの株、野生株(NC4)と放射線感受性突然変異株(γs13)を使用した。NC4とγs13の乾燥した胞子を大腸菌細胞と共に細胞性粘菌培養キットに収めた。打ち上げ後7日目に、胞子から発生したアメーバの成長状態をチエックしたところ、採餌は認められなかった。そこでNASAケネディ宇宙センター(KSC)のバイオラック上の対照キットの成長状態を調べたところ、胞子からアメーバの成長は全く生じていなかった。実験を完全なものにできないので、この実験は終了し、キットは冷蔵庫へ移した。この後実験の目的を、発芽、細胞成長、および胞子の突然変異頻度に対する宇宙放射線の影響へと変更した。NC4の宇宙試料の全胞子と対照はすべて発芽し、アメーバは処理後成長した。γs13では対照試料中1試料内でのみ胞子は発芽した。宇宙試料中では発芽処理後でさえ、発芽は検出できなかった。宇宙試料と対照NC4試料とでは、アメーバの成長速度には違いが見られなかった。アメーバにより形成された子実体の形は、宇宙に送った胞子または地上に対照として残された胞子を使用して検査した。宇宙試料と対照NC4試料では、子実体の異常さになんら差は見られなかった。さらに、宇宙試料と対照NC4試料では、突然変異率に全く差は見られなかった。宇宙放射線は、γs13胞子での発芽抑制を誘導しているが、NC4胞子では誘導しないことを、これらの結果は示唆している。NC4の場合、地上対照と比べ、発芽、細胞成長、形態、突然変異頻度に対して、宇宙環境は全く影響を及ぼしていない。, Two strains of the slime mold Dictyostelium discoideum, a wild-type strain (NC4) and a radiation-sensitive mutant (gamma sl3), were used to investigate the effects of cosmic radiation and/or microgravity through the whole life span on cell morphology and cell differentiation. Dry spores of NC4 and gamma sl3 were placed in a slime mold cell culture kit with Escherichia coli cells. On the seventh day after launch, the growth condition of the amoebae that developed from the spores was checked and feeding was not detected. Therefore the growth condition of one control kit in the biorack at KSC was investigated, and no growth of amoeba from the spores was evident. Since the experiment could not been completed, the experiment was terminated and the kit moved to a refrigerator. After this, the purpose of the experiment to measure the effects of cosmic radiation on germination, cell growth and mutation frequency of the spores was changed. All the spores of space sample and the controls of NC4 germinated, and the amoebae grew after the treatment. In gamma sl3, only the spores in one of the control samples germinated. The germination of spores in the space sample could not been detected even after the germination treatment. There was no difference in the growth rate of amoebae between the space and control NC4 samples. The shapes of fruiting bodies formed by the amoebae were examined using spores sent into space or left on Earth as controls. There was no difference in abnormality of fruiting bodies between the space and the control NC4 samples. In addition, there was no difference between the mutation rate for the space sample and that of the control in NC4. From these results, it is suggested that cosmic environment may induce the depression of germination in gamma sl3 spores, but not in NC4 spores. In NC4, however, the cosmic environment is no effect on germination, cell growth, morphology and mutation frequency as compared as the ground control., 資料番号: AA0000271006, レポート番号: NASDA-TMR-960004

Biological effect of heavy ions accelerated by ring cyclotron has been investigated, since heavy ions have been considered as predominantly important radiation to estimate biological effect by space radiation. Here it is reported that phosphorylated histone H2AX at ser 139 (gamma-H2AX) and NBS1, which are required for efficient DNA double-strand break repair by homologous recombination, form large undissolvable foci after exposure to accelerated Fe ions. These results suggest that unrepairable DNA clustered damage is induced by heavy ions, in vivo and gamma-H2AX and NBS1 can be used as molecular marker of DNA clustered damage., 資料番号: AA0045438004

平成4年にアメリカ航空宇宙局のスペースシャトル/スペースラブを利用して、宇宙開発事業団が行った第1次材料実験に関して、搭載装置の開発、運用および搭乗科学技術者の訓練結果などについてとりまとめ、事業団としての評価を行った。実験の目的は、スペースシャトルに日本人科学技術者が搭乗し、宇宙空間の特性を利用した材料実験、ライフサイエンス実験を行うとともに、宇宙実験技術および有人宇宙技術の習得を行うことである。その方針としては、(1)わが国の技術能力を越える範囲の宇宙活動として、本格的宇宙実験および有人飛行の実現可能なスペースシャトルを利用しながら、わが国の宇宙開発を国際的に高いレベルで推進する、(2)搭載実験システムの開発および搭乗科学技術者の訓練などをできるだけ自主技術で行い、技術の蓄積につとめる、(3)幅広い範囲から実験テーマを募集するとともに、地上で十分な予備実験を重ね、可能な範囲で多くの実験を行う、などを考慮した。搭載した実験装置は3種類の電気炉などを含む計測装置、細胞培養装置などの実験用装置を含めて22種類、また実験テーマとして材料関係22,ライフサイエンス関係12,さらに日本人搭乗科学者の健康管理データの取得を目標とした。第1次材料実験は、実験運用中、実験装置に一部不具合があったものの、当初の計画どおり34テーマの実験を実施でき、宇宙実験技術および有人宇宙技術に関するデータの取得が行われた。また今後の宇宙実験計画に対する反映事項も明らかにされ、宇宙実験技術の蓄積および有人宇宙活動に関する基盤技術の取得という、第1次材料実験計画の初期の目的が達成されたことを確認した。, National Space Development Agency of Japan (NASDA) carried out First Material Processing Test (FMPT) in NASA's Space Shuttle and Space Love in 1992. This paper summarizes the development and operation of space experiment apparatus and the training results of a payload specialist. This paper also includes the evaluation of the results by NASDA. The purposes were to carry out experiments on materials and life science by using cosmic space characteristics and to learn the space experiment techniques and manned space flight technologies. The policies included promoting the Japanese space development project at internationally high level using the Space Shuttle where full-scale space experiments and manned flight exceeding Japanese technologies are possible, developing on-board experimental systems and training scientists by Japanese technologies as much as possible for accumulating technologies, and inviting extensive experimental subjects and carrying out as many experiments as possible with sufficient preliminary ground experiments. 22 experimental apparatus were loaded, including cell culture devices and measuring instruments including three electric furnaces. The experimental subjects included 22 subjects on materials and 12 on life science. Health care data on a Japanese payload specialist were also collected. The 34 subjects were carried out as scheduled although some of the FMPT experiment apparatus malfunctioned. Data on space experiment techniques and manned spaceship technologies were collected. The results also showed the issues to be reflected in future space experiment planning. The initial purposes of the FMPT, such as accumulating space experiment techniques and obtaining the basic technologies for manned space flight, were achieved., 資料番号: AA0004115001, レポート番号: NASDA-TMR-940002 V.1

HZE(高エネルギー重荷電粒子)および宇宙放射線の遺伝的影響を調べるため、ショウジョウバエ(Drosophila melanogaster)の成虫雄と幼虫をスペースシャトル/エンデバー号(STS-47)に搭載し、雄の生殖細胞(精子やその元となる精原細胞など)に起こる伴性劣性致死突然変異と、幼虫の翅原基体細胞に起こる染色体のつなぎかえによる突然変異を調べた。用いた系統は、標準的な野生株(Canton-S)と放射線高感受性株(mei-41)である。各系統で、成虫雄は200匹ずつ、幼虫は約6000匹ずつを搭載し宇宙環境に曝すとともに、ほぼ同数を地上対照群として、宇宙飛行群と同じ環境条件(温度と湿度)で飼育した。宇宙飛行は約8日間であった。帰還した雄のハエは、伴性劣性致死突然変異を調べるため、検出用系統の処女雌に交配し、次々世代で致死遺伝子を保有しているX染色体を検出した。宇宙飛行群の致死遺伝子をもった染色体頻度は、地上対照群の頻度に比べて、野生株では2倍、放射線高感受性株では3倍高かった。幼虫は、帰還時にほとんどが蛹になっており、翌日より徐々に羽化が始まった。羽化した成虫は、順次70%アルコールで貯蔵し、後に翅標本を作成して、染色体突然変異由来の翅毛変異スポットを調べた。野生株では、宇宙飛行群と地上対照群の頻度は、ほぼ同じであった。放射線高感受性株から分離してくるMuller-5個体における頻度は、地上対照群に比べて宇宙飛行群では、1.5倍高かった。しかし、放射線高感受性個体における宇宙飛行群の頻度は、地上対照群に比べて有意に低い頻度を示した。地上対照群に比べて、宇宙飛行群の劣性致死突然変異の高頻度は、生殖細胞において、放射線と微小重力の突然変異誘発作用への相乗効果を示唆している。しかし、この相乗効果は、体細胞の染色体突然変異誘発作用に対しては観察されなかった。, For examining the genetic effects of High Energy Heavy ions (HZE) and cosmic radiation, adult males and larvae of fruit flies (Drosophila melanogaster) were loaded on the Space Shuttle, Endeavor (STS-47), and sex-linked recessive lethal mutation in the male germ cells (spermatozoa and spermatogonia that produce them) and chromosome-recombination-derived mutation on the larva wing basal somatic cells were investigated. The strains used were a standard wild type strain (Canton-S) and a radiation sensitive strain (mei-41). Two-hundred adult males and about 6000 larvae of each strain were loaded and exposed to the cosmic environment. At the same time, almost the same number of adult flies and larvae were bred in the same environmental condition (temperature and humidity) as ground control groups. The flight period was about eight days. The returned male flies were mated with virgin female flies from a detection strain for investigating sex-linked recessive lethal mutation. X chromosomes with lethal genes were detected on the second generation. In the returned flies, the frequency of chromosomes with lethal genes was two times higher in the wild type strain and three times higher in the radiation sensitive strain than that of the ground control groups. Most of the returned larvae were in the pupal stage on the return day, and began to emerge on the next day. The emerged adult flies were stored in 70 percent alcohol solutions, and their wing samples were prepared for investigating the wing mutation spots derived from chromosome mutation. Mutation frequency in the wild type strain was almost the same between the flight and ground groups. The frequency in the Muller-5 individuals separated from the radiation sensitive strain was one and half times higher in the flight group than in the ground control group. However, the frequency in the radiation sensitive strain was significantly lower in the flight group than the ground group. The higher recessive lethal mutation frequency in the flight group suggests the synergistic effect of radiation and minute gravity on mutation induction in germ cells. However, this synergy effect was not observed on the chromosome mutation induction in somatic cells., 資料番号: AA0004115012, レポート番号: NASDA-TMR-940002 V.1

地球近傍の宇宙環境には多種の放射線が存在するが、その中で宇宙飛行士や搭載ペイロードにとって問題となるのは、プロトン以上の質量の高エネルギー粒子放射線(HZE)である。この実験では、宇宙放射線の中でも宇宙船の外壁を容易に貫通して船内に到達するHZE粒子や、この粒子線が船体やペイロードなどと相互作用して生ずる2次的な放射線を、飛跡検出材や熱蛍光性線量計で計測するとともに、これらの宇宙放射線の生物への影響を細胞レベルから個体レベルまでの異なった側面から研究、評価することを目的に行われた。宇宙実験に使用した装置は宇宙放射線モニタリングコンテナ2組とドシメータ13組であり、前者には、ハーツラスと呼ばれる固体飛跡検出材の間に生物試料を挟んだスタックを積層、充填し、後者には主としてハーツラスと熱蛍光線量計(TLD)を入れたものである。使用した生物試料は、放射線に感度の高いトウモロコシと大豆の種子、乾燥豊年エビ卵、DNA修復能を欠いた大腸菌突然変異株を中心に合計14種類のバクテリアを搭載した。これらの検出器および生物試料は、エンデバーでの宇宙実験終了後、約2週間で日本に返送され、物理的な線量解析と生物影響に関する実験を行った。TLDによる線量計測結果は、フッ化リチウム型TLDに関してはばらつきが大きく得られた価の信頼性が低かったが、ケイ酸マグネシウム型TLDは、被曝線量値が低いにもかかわらずばらつきの少ない良好な結果を与えることが解った。また、固体飛跡検出材の解析から得られた高エネルギー粒子線の線エネルギー付与率(LET)の分布は、IML-1ミッションやD-1のような同軌道のミッションで得られた結果と定性的にはよい一致を示したが、TLDと固体飛跡検出材両者の結果から推定された吸収線量率と線量当量率の比は、NASAジョンソ宇宙センターで計測された値と比較しかなり低い値を示した。生物試料に関し、2種の植物種子の体細胞突然変異率には、統計的に有為な変化は認め得なかったが、トウモロコシにくらべダイズがより放射線に敏感であることは相対的に確認することができた。豊年エビ卵は、試料の上下に置かれた飛跡検出材のエッチピット解析から、重粒子線に被曝した卵のみを弁別することが出来、幼生細胞に現われるピクノーシス頻度は地上群に比較し有為に上昇していることが解った。プラズミドDNApHY300PLKを保持した乾燥枯草菌胞子のテトラサイクリン耐性保持率は、地上対照試料では約90%であったが、フライト試料では約70%に低下しており、プラズミドDNA上に損傷が生じたか、宿主側の遺伝子に何らかの障害が出たことを示唆した。また、DNA修復能に関与する酵素活性を欠いた11種類の大腸菌突然変異株については、帰還後の生存率の変化について比較解析した結果、宇宙放射線からのDNA損傷の修復には、エキソヌクレアーゼ(特に3'→5')活性の寄与が大きく、紫外線損傷の修復系であるUVエンドヌクレアーゼ活性はほとんど寄与していないことがわかった。また、エキソヌクレアーゼ系を含んだ多重欠損突然変異株では、その多重度に依存して生存率が低下する事がわかった。これらの結果は宇宙放射線の生物影響がDNAのような分子レベルの領域に局在した、かなり顕著な作用を与えており、今後さらに詳細な実験や解析が心要なことを強く示唆している。, This experiment aims to measure cosmic radiation, especially Highly EnergiZed Electrons (HZE) that easily reaches the inside of a space ship by penetrating the outer wall, and secondary radiation generated from the synergetic effects between HZE and the ship body and payloads, using track detecting materials and a thermoluminescence dosimeter. This experiment also aims to investigate and evaluate the effects of the cosmic radiation on organisms at different levels such as cellular or individual level. The equipment used consists of two sets of cosmic radiation monitoring containers and 13 sets of dosimeters. The former was filled with piled stacks in which organic samples were sandwiched between solid state track-detecting materials called 'Hurtlus'. The latter includes the Hurtlus and ThermoLuminescence Dosimeters (TLD). The organic samples used include corn and soybean seeds that are sensitive to radiation, dried Artemia salina eggs, and 14 bacteria such as Escherichia coli mutants without DNA repair ability. These detecting devices and organic samples were returned to Japan for physical dose analysis and biological experiments about two weeks after the experiments in the Endeavor were over. Measuring doses with lithium fluoride TLD resulted in large dispersion with low reliability. However, measuring doses with magnesium silicate TLD showed good results with little dispersion in spite of low dose. Distribution of HZE's Liner Energy Transfer (LET) derived from solid track-detecting material analysis showed good qualitative agreement with the results of the same orbital experiments, such as IML-1 or D-1. However, the ratio of absorbed dose rate to dose equivalent rate, which was inferred from the results of the TLD and solid state track-detecting materials, was lower than that measured in the Johnson Space Center of NASA. The two kinds of plant seeds did not show any statistically significant change in somatic cell mutation: the soy bean seeds were confirmed to be more sensitive to radiation than corn seeds. Etch pit analysis of the track-detecting materials sandwiching the Artemia salina eggs allowed us to choose the eggs exposed to heavy ion beams. The exposed eggs showed that the picnosis frequency of juvenile cells was significantly higher than the ground samples. The tetracycline-resistant rate of dried Bacillus subtilis spores bearing plasmid DNA pHY300PLK was about 90 percent in the ground samples, while that of the flight samples was about 70 percent. This decrease suggests damages on the plasmid DNA or damaged host genes. The change in the survival rate of the 11 Escherichia coli mutants without enzyme activities involved in DNA repair was comparatively analyzed after returning to the Earth., 資料番号: AA0004115014, レポート番号: NASDA-TMR-940002 V.1

プレスなどへの公開用資料として、ISS米国実験棟における中性子計測実験の概要をまとめたものである。1)中性子計測実験の概要、2)別添1:スペースシャトルシステムの概要、3)別添2:国際宇宙ステーション(ISS)の概要。, 資料番号: AA0046973000, レポート番号: JAXA-RM-03-020

NASDAは、NASAのシャトル/ミールミッション(S/MM)計画の4回目の飛行機会を利用して、宇宙放射線データを実時間放射線計測装置(RRMD)により取得した。本計画では次のことを目的とした。(1)宇宙ステーション軌道での放射線環境計測、(2)計測データの放射線環境評価への利用、(3)被曝管理システム構築のための源泉データとして利用、および(4)生物試料への放射線影響の調査。NASDAの実験装置はSTS(スペースシャトル輸送システム)-79/アトランティス号に搭載されたスペースハブに組込まれた後、飛行に供された。実験テーマは次の通りである。(1)宇宙放射線の実時間線量計測、(2)宇宙放射線が与える大腸菌突然変異細胞への影響、(3)DNA修復に及ぼす宇宙環境、および(4)宇宙放射線環境データの実時間交換。実験装置は良好に稼動し、ほぼ計画どおり実験でき、多くのデータを取得した。また、生物試料も所定の操作が行われた。, Using the fourth flight opportunity of the Shuttle/Mir Mission (S/MM) project of NASA, NASDA acquired the cosmic radiation data by Real time Radiation Measurement Device (RRMD). In this project, the following items were aimed at: (1) radiation environment measurement in space station orbit; (2) utilization of measured data to radiation environment evaluation; (3) utilization as source data for the construction of exposure management system; and (4) investigation of radiation effect to biological sample. The experimental equipment of NASDA was launched on orbit after assembled in Spacehab onborded on the STS (Space Transportation System)-79/Atlantis orbitor. Experimental themes were as follows: (1) real time dosimetry of the cosmic radiation; (2) effect to a escherichia coli mutagenized cell which the cosmic radiation gives; (3) space environment on DNA repair; and (4) real time exchange of cosmic radiation environmental data. The test equipment worked well, and testing were almost performed according to the test plan, and much data were acquired. And, the experiments of biological sample were also carried out by the fixed operation., 資料番号: AA0001366000, レポート番号: NASDA-TMR-970007

The Ekar rat model of hereditary renal carcinoma (RC) is an example of Mendelian dominantly inherited predisposition to a specific cancer in an experimental animal. Effects of space radiation on carcinogenesis are investigated by using heavy-ions at HIMAC. First, analyzed was radio sensitivity of Ekar rats; compare the effects of heavy-ions (C-290 MeV/u, Fe-500 MeV/u) irradiation and X-ray irradiation. Pregnant rats were exposed to carbon-ion, iron-ion and X-ray at a single dose of 1 Gy, 2 Gy, 3 Gy on day 19 of gestation. The offspring were sacrificed at 8 weeks of age. RC developed in Ekar rats around the age of 8 weeks. The incidence of RC is investigated by comparing C-290 MeV/u, Fe-500 MeV/u and X-ray., 資料番号: AA0046917023

A Novel SCID technology is established for biomedical studies to evaluate the effect of space radiation on human organs and tissues. Morphology and function of human tissues were well maintained in the improved severe combined immunodeficient (SCID) mice for long period (2 to 3 years). Cs-137 ray exposure to transplant human thyroid tissues resulted in the disappearance of the follicles, significant decrease of human thyroid hormones, an increase of mutations, and change of gene expression, while low dose rate radiation exposure rarely induced these defects. Change of gene expression was also induced in extremely high incidence by fission neutron., 資料番号: AA0046917024

担当教員: 鈴木信夫ほか, 平成22年度(2010)教養コア科目授業F(いのちと科学),授業コード:G14F21101

担当教員: 鈴木信夫ほか, 平成22年度(2010)教養コア科目授業F(いのちと科学),授業コード:G14F21101