维生素E对果蝇辐射氧化损伤机制的影响

目的 探索不同浓度维生素E对γ射线照射后果蝇幼虫敏感性的影响。 方法 使用不同浓度（100、500、1000、1500 mg/L）维生素E处理W1118果蝇幼虫,137Cs γ射线 50 Gy 进行照射,测定果蝇幼虫的蛹化率和羽化率、羽化后48 h死亡率、过氧化氢酶（CAT）活性和谷胱甘肽（GSH）含量,分析其抗氧化能力和氧化损伤状态。组间的比较采用LSD-t检验。 结果 1000、1500 mg/L维生素E组果蝇幼虫的蛹化率、羽化率、攀爬能力、CAT活性、GSH含量均明显比单纯照射对照组高,且差异均有统计学意义（t=2.864~16.462,均P<0.05）。与未照射对照组比较,1000 mg/L和1500 mg/L维生素E组的果蝇幼虫羽化为成虫48 h内的死亡率分别从（54.0±5.0）%降低至（36.1±7.6）%和（37.5±5.8）%,差异均有统计学意义（t=3.386,P=0.028;t=3.718,P=0.021）。 结论 维生素E通过减少氧化性应激来减缓果蝇幼虫辐照后的氧化损伤,并能提高果蝇的辐射抗性。     

不同运动方案对果蝇运动能力、生命周期及心脏功能的影响

目的:研究不同运动方案对果蝇运动能力、生命周期及心脏功能的影响,探讨抗心脏衰老果蝇运动模型的建立。方法:12 h内羽化雄性野生型w1118品系果蝇3600只,随机分为6组:空白对照组、1.5 h运动组、2 h运动组、2.5 h运动组、3 h运动组、3.5 h运动组,每组600只。于8天龄进行3周平台运动,采用攀爬指数评定果蝇运动能力;统计果蝇平均寿命、半数死亡时间、最长寿命和平均延寿率;应用果蝇心力衰竭模型,检测31天龄、38天龄果蝇心脏衰竭率。结果:果蝇攀爬指数随着年龄增加而下降,运动第3周,2.5 h运动组果蝇攀爬指数明显大于其他各组。与空白对照组相比,2.5 h运动组平均寿命显著增加(P<0.01),1.5 h运动组、2 h运动组、3 h运动组和3.5 h运动组无变化;1.5 h运动组、2 h运动组、2.5 h运动组、3 h运动组、3.5 h运动组平均延寿率分别为1.36%、2.87%、5.86%、2.80%、-0.85%;与空白对照组相比,1.5 h运动组、2 h运动组、2.5 h运动组和3h运动组果蝇存活曲线上移、右移,3.5 h运动组存活曲线下移、左移。31天龄空白对照组、1.5 h运动组、2 h运动组、2.5 h运动组、3 h运动组、3.5 h运动组果蝇心脏衰竭率分别为56%、58%、52%、46%、57%和69%,38天龄空白对照组、1.5 h运动组、2 h运动组、2.5 h运动组、3 h运动组和3.5 h运动组果蝇心脏衰竭率分别为71%、68%、65%、62%、74%和80%。结论:8天龄开始,持续3周每天1.5 h至3 h的运动可增强果蝇运动能力,延缓因增龄而发生的运动能力下降、心脏功能衰退,改善生命周期,以每天2.5 h持续3周的运动效果最好,可以此方案建立抗心脏衰老果蝇运动模型。     

间歇性低氧与规律运动对中老龄果蝇心脏泵血能力及生活质量的影响

目的:探讨适宜的规律运动与间歇性低氧对中老龄果蝇心脏泵血功能与生活质量的影响。方法:通过扩大培养收集8 h内羽化的W1118品系处女蝇4500只,随机分为三个低氧年龄段(n=1500):青年低氧组(1~2周)、中年低氧组(3~4周)与老年低氧组(5~6周)。低氧结束后利用心力衰竭模型筛选出最佳低氧年龄段与低氧持续时间。再通过扩大培养收集8 h内羽化的W1118品系处女蝇1200只,随机分为常氧安静组(NC组)、常氧运动组(NE组)、低氧安静组(HC组)和低氧运动组(HE组)。HC与HE组果蝇采用6%O2与94%N2的混合气体,每天低氧6 h,NE与HE组果蝇每天运动2.5 h,低氧与运动干预结束的第二天进行心脏泵血能力与生活质量相关指标的检测。结果:(1)果蝇的心力衰竭率随年龄的增长而上升,中年组及老年组果蝇心力衰竭率随低氧暴露时间的延长逐渐下降。(2)NE组果蝇心脏舒张直径显著高于NC组与HC组(P<0.05,P<0.01),HC组显著低于NC组与HE组(P<0.05,P<0.01);HC组果蝇收缩直径显著低于NC组与HE组(P<0.05,P<0.01);NC组果蝇心脏射血分数显著低于NE组(P<0.01)。(3)NE组、HC组与HE组果蝇攀爬速度均显著高于NC组(P<0.05,P<0.01)。(4)HC组及HE组果蝇夜晚睡眠总时间显著长于NC组(P<0.05,P<0.01),HC组果蝇夜晚睡眠段数显著小于NC组(P<0.01)。(5)NE组果蝇活动总量显著高于其他三组(P<0.05),而HC组显著低于NC组(P<0.05),NE组果蝇清醒睡眠时间比以及单位活动时活动量均显著高于其他三组(P<0.05),HC组果蝇单位活动时活动量显著高于NC组与HE组果蝇(P<0.05),其日间活动时间显著低于NC组。(6)HC组果蝇最高寿命显著高于NC组与NE组(P<0.01)。HC组果蝇平均寿命显著高于其他三组(P<0.01),HE组果蝇平均寿命显著高于NC组与NE组(P<0.05)。结论:规律运动与间歇性低氧均能增强中老龄果蝇的攀爬能力与日常活动能力,但与规律运动能增强中老龄果蝇心脏泵血能力不同,间歇性低氧能减小其心管直径、增强夜间睡眠质量、延长寿命,而低氧联合运动能提高中老龄果蝇的攀爬能力、延长其平均寿命和夜间睡眠时间。     

人头低位倾斜时脑血流速度的增加

在微重力及模拟微重力状态下,由于下身血流及组织间液向上身转移,下肢容积缩小。已证明用头低位方法来模拟微重力时,头部毛细血管和皮肤的血流是增加的。猴头低位限制活动7天和9天,用形态学方法检查证明有脑血管舒张和血管周围水肿,这些现象都表明体液头向分布可影响脑循环。     

模拟微重力条件理植物细胞亚显微结构的研究

目的 研究微重力条件对植物生长发育中细胞亚显微结构的影响。方法 微重力仪连续改变方向来获得模拟微重力,对模拟微重力条件下生长的植物进行了细胞学、生理学实验。结果电镜观察表明：植物细胞在模拟微重力条件下正常重力条件生长的相比,在细胞壁、叶绿体,线粒体等方面产生变异,细胞出现了壁质分离现象,部分细胞壁扭曲、收缩变形,部分叶绿体片层结构出现了弯曲、排列疏松,内含物溢出,部分线粒体出现了边缘模糊及嵴消失的     

航空航天医学学会(AsMA)的医生成为航天飞机的乘员

NASA最近宣布了未来8项航天飞机任务的乘员名单。其中,AsMA会员,德克萨斯州休斯顿的E. S. Baker博士将成为美国STS—50微重力实验室飞行任务的载荷专家。该任务计划于1992年6月实施,包括微重力材料收集处理技术实验等,历时13天,是目前该类任务中时间最长的一项。     

长期模拟微重力对人体下肢肌肉影响的研究

已观察到长期航天后航天员下肢肌肉力量和体积减小。但是,现在基于微重力对人体肌肉结构和功能影响的资料有限,因此难于发展在微重力时降低肌肉变化的对抗措施,在致力于较好地解释肌肉     

模拟微重力条件下植物细胞亚显微结构的研究

目的 研究微重力条件对植物生长发育中细胞亚显微结构的影响。方法 通过微重力仪连续改变方向来获得模拟微重力,对模拟微重力条件下生长的植物进行了细胞学、生理学实验。结果电镜观察表明：植物细胞在模拟微重力条件下与正常重力条件生长的相比,在细胞壁、叶绿体,线粒体等方面产生变异,细胞出现了壁质分离现象,部分细胞壁扭曲、收缩变形,部分叶绿体片层结构出现了弯曲、排列疏松,内含物溢出,部分线粒体出现了边缘模糊及嵴消失的情况,同时细胞内淀粉粒明显增多。结论 模拟微重力对植物的正常生长起到了一定协迫作用,使植物细胞发生了变异。     

微重力条件下人体体液调节模型的分析与改进思考

航天和模拟微重力时研究表明：微重力与现有模拟微重力模型时人体生理学变化的主要差异表现在低压区循环和体液、电解质代谢。微重力生理研究的人体模型在进一步了解微重力对人体的生理影响和机理中不可缺少,有必要将现有人体模拟微重力模型加以改进。利用人体不同角度和不同压力制度的立位倾斜（ＨＵＴ）加下体正压、头低位卧床（ＨＤＴ）加上体负压,测量心血管参数、体液调节因子、肾排泄的有关指标,与航天中的相应指标对照,筛     

NASA的研究通告

美国航空航天局(NASA)空间科学与应用办公室(OSSA)的微重力科学与应用分部(MSAD)目前正着手实施一项有关微重力环境方面的基础研究计划,目的是提高对基础科学中主要是物理学、化学和生物学过程的认识。在这项定名为“微重力基础科学:研究和飞行的良机”的计划中,MSAD 使用了微重力的实验来进行流体     

卫星空间飞行对遗传影响的研究：果蝇伴性隐性致死试验

本工作以黑腹果蝇为实验材料,采用Muller-5检测技术,进行了伴性隐性致死频率的卫星空间飞行试验。结果表明,卫星空间飞行的综合因素对果蝇伴性隐性致死频率变异有增高趋势。提示我们,空间飞行因素的遗传效应及其防护的研究仍是今后应重视的研究课题。     

Morphohistochemical study of skeletal muscles in rats after experimental flight on "Kosmos-1887"

Morphometric and histochemical methods were used to examine the soleus, gastrocnemius (medial portion), quadriceps femoris (central portion) and biceps brachii muscles of Wistar SPF rats two days after the 13-day flight on Cosmos-1887. It was found that significant atrophy developed only in the soleus muscle. The space flight did not change the percentage content of slow (type I) and fast (type II) fibers in fast twitch muscles. During two days at 1 g the slow soleus muscle developed substantial circulation disorders, which led to interstitial edema and necrotic changes. The gastrocnemius muscle showed small foci containing necrotic myofibers. Two days after recovery no glycogen aggregates were seen in myofibers, which were previously observed in other rats examined 4--8 hours after flight. An initial stage of muscle readaptation to 1 g occurred, when NAD.H2-dehydrogenase activity was decreased.     

航天因素对螺旋藻生长的影响

螺旋藻是一种有希望成为载人航天提供气体交换和食品来源的藻类。我们利用返地式卫星的8天航天飞行条件,研究微重力等航天因素对飞行后螺旋藻生长发育的影响。结果表明,航天后的螺旋藻形态、生长和发育与地面对照没有显著差异,但航天螺旋藻的指数生长期的生长率快于地面对照(p<0.05)。     

不同剂量137Cs γ射线照射对雌果蝇的辐射损伤和氧化效应

目的了解不同剂量γ射线照射对雌果蝇产生的辐射损伤与氧化效应。方法采用不同剂量137Cs γ射线照射白眼W1118、红眼UAS-EGFP和Actin-Gal4雌果蝇,再测定其生存、运动和生殖能力。通过测定雌果蝇体内过氧化氢酶（CAT）活力和丙二醛（MDA）含量对果蝇成虫的辐射和氧化损伤进行评价。组间比较均采用LSD-t检验进行统计学分析。结果137Cs γ射线对W1118、UAS-EGFP、Actin-Gal4的半数致死剂量分别为1513、1643、1809 Gy;3个品系3日龄雌果蝇成虫的生存率、攀爬高度分数、产卵量与γ射线照射剂量呈负相关;与未照射组相比,1550 Gy照射后雌果蝇成虫体内的CAT活力降低,差异有统计学意义（t=10.76、13.84、11.22,均P < 0.05）;MDA含量升高,差异有统计学意义（t=4.51、4.26、4.35,均P < 0.05）。结论高剂量γ射线照射导致的雌果蝇成虫的生存、运动和生殖能力降低可能与其氧化损伤相关。     

Effect of space flight factors on bone marrow cells in the rat

The effect of space flight factors, weightlessness in particular, on the genetic structures of bone marrow cells of rats flown for 18.5 days on Cosmos-1129 was investigated. Chromosome aberrations were measured on postflight days 6 and 25. The frequency of unstable chromosome aberrations was similar in the flight, synchronous and vivarium rats. Karyotyping of metaphase plates revealed chromosome aberrations in the flight and synchronous rats. Exposure to weightlessness did not influence the mutagenic effect in bone marrow cells of the rats.     

The first experience using soft contact lenses during long-term space flights

During a long-term flight on Salyut-7 and Mir orbital stations a contact lens was used for the first time in order to correct mild ametropia of one of the crew members. He used a soft contact lens for 5 hrs on flight days 10, 30, 45 and 60. As a result, acuity of vision of the treated eye increased to 1.5. This study showed that contact lenses can be employed in space flight.     

Energy reactions in the skeletal muscles of rats after short-term space flight on Kosmos-1514

Ten hours after the 5-day space flight on Cosmos-1514 rats were examined for oxidative phosphorylation in mitochondria isolated from the posterior femoral muscles as well as for Krebs cycle enzymes and glycolysis in the mitochondrial and cytoplasmic fractions of the muscles. The mitochondrial respiration rate in various metabolic states was similar in flight rats and vivarium controls. After flight calculated parameters of energy efficacy of respiration as well as activity of malate dehydrogenase, isocitrate dehydrogenase and total lactate dehydrogenase remained unchanged. Unlike the flight rats, the synchronous controls showed signs of the stress-reaction: uncoupling of oxidative phosphorylation and oxalacetate inhibition of succinate dehydrogenase. Comparison of these findings with those from prolonged space flights indicates that inhibition of oxidative metabolism and glycolysis in mixed muscles which was demonstrated in the 20-day space flight does not develop immediately after launch but occurs within the time interval between mission days 6 and 18.     

Phenomenology and mechanisms of changes in the basic functions of the human body in weightlessness

In the course of the space era the duration of manned flights increased from 108 minutes to 326 days. During the flights a large number of biomedical investigations were carried out to study the phenomenology and mechanisms of space flight effects on the human body. It was demonstrated that exposure to microgravity produced most significant changes. Short-term effects include space adaptation syndrome changes associated with fluid shifts and changes in movement coordination. Long-term effects involve various changes in the musculoskeletal system, cardiovascular system, metabolism and its regulation, endocrine system, blood and immunity system. This paper describes symptom-complexes that are consistently observed in space flight, discusses mechanisms of changes and adaptation of vital physiological systems, and outlines main periods of changes during and after flight.     

Problems of variability in weightlessness

The genetic (cytogenetic) effects of microgravity have been under study for about 30 years. This line of research developed through three periods. Initially, biologists raised the question whether microgravity may act as a lethal factor or a strong mutagen. Many flight experiments gave a negative answer to it. The major goal of the second period was to identify the effects of microgravity at the chromosomal and cellular levels. Such effects, statistically significant although small in value, were detected in Tradescantia paludosa and Drosophila melanogaster microspores. These findings were confirmed by American and--later--by European investigators. The third period addresses the entire problem of variability in microgravity. This approach can be implemented on the basis of a comprehensive program of research that will include experiments at different levels: from the gene to the population level. The basic objective of the program is to clarify the role of the genetic apparatus in the adaptation of living systems to microgravity and, consequently, to determine the role of gravity in the evolution of life on the Earth.     

空间飞行诱导绿菜花的花粉母细胞染色体畸变研究

目的 研究空间飞行处理对绿菜花的细胞学效应和引起植物突变的原因及作用机理。方法 种子经科学返回式卫星搭载飞行８ｄ回收后种植,研究其种子长成植株的生长情况及其生长势,并用朱澄１９８２年的方法对其花粉母细胞的减数分裂行为进行染色压片观察。花粉样品用乳酸苯酚染色测定花粉育性。结果 绿菜花抽茎开花提前,叶片的蜡质减少,并观察到其花粉母细胞减数分裂的终变期的染色体数目不均等分离：如减少ｎ＝６,７或增加ｎ＝１