代谢抑制剂对萌发绿豆超弱发光的影响

本文报导了A.D(actinomycin D)、EB(ethidium bromide)、CHI(cycloheximide)及NaN_3,对萌发绿豆(胚根长1.5cm左右)的自发性超弱发光强度的影响的研究结果,提供了DNA分子和/或RNA合成代谢对超弱发光有贡献的证据.     

生物超弱发光研究

生物超弱发光是自然界普遍在的一种生命现象。本文概述了近年来生物超弱发光研究的进展,探讨了生物超弱发光在医学和农业上应用的可能性,并提出了该领域有待深入研究的问题。     

化学物质对哺乳动物细胞超微弱发光的影响

各种不同的化学物质可以以不同的方式影响光子发射.实验所用的化学制剂为过氧化氢、硫酸亚铁铵、氢氧化钠、盐酸及乙醇.从光子发射的暂时过程,可以看到两种类型反应.添加过氧化氢或氢氧化钠可导致初始的光子发射增强,以后随时间推移而迅速降低.加入Fe~(2 ) K_2Cr_2O_7或乙醇以后则有完全不同的发光动力学过程.V_(79)细胞的超微弱光子发射被认为是整个细胞的一种性质, 实验结果表明, 各种化学物质可以引起光子发射的明显增加或降低,但光谱分布却来看出变化,上述化学制剂的作用仅仅是刺激或抑制光子发射.     

血清的超弱发光与疾病诊断

血清或血浆中存在着与脂质新陈代谢相关联的超弱发光的现象。机体病变时,血清的超弱发光会发生相依的变化。因此,血清趋弱发光的变化可以作为疾病的辅助诊断之用。本文简要地介绍了血清的发光机理、探测方法、影响因素及在某些疾病诊断中的应用。     

绿豆和花生的超弱发光

对黄化绿豆幼苗光形态建成过程的超弱发光图象的初步观察发现：见光培养４０ｍｉｎ后绿豆幼苗即可探测到明显的延迟发光;见光时间越长,光诱导的延迟发光强度也越强。从绿豆和花生幼苗的超弱发光图象来看,生长健壮的幼苗发光较强。其中茎尖和新生幼叶的延迟发光最强,上胚轴,子叶和一胚轴钩较强,下胚轴伸长部分次之,根部发光最弱。     

绿豆和花生的超弱发光

对黄化绿豆幼苗先形态建成过程的超弱发光图象（延迟发光）的初步观察发现：见光培养40min后的绿豆幼苗即可探测到明显的延迟发光;见光时间越长,光诱导的延迟发光强度也越强。从绿豆和花生幼苗的趋弱发光图象来看,生长健壮的幼苗发光较强。其中茎尖和新生幼叶的延迟发光最强,上胚轴、子叶和下胚轴弯钩较强,下胚轴伸长部分次之,根部发光最弱。从不同发育阶段叶片的超弱发光图象来看,光合作用较强、新陈代谢旺盛的成熟叶片的超弱发光较强;光合作用和其它代谢过程相对较弱的叶片（伸展叶、老叶和幼叶）,其超弱发光强度相应较弱。而叶绿素提取液和失活绿叶观测不到超弱发光。此外,对超弱发光光谱的初步研究表明它很可能来自光合作用中叶绿素的发光。这些都暗示,植物的（诱导）超弱发光与光形态建成和光合作用等生长代谢过程密切相关。     

白菜叶绿体的超弱发光机理初探

从先前对黄化绿豆幼苗光形态建成过程和花生叶片不同发育阶段的超弱发光 (ＵＢＥ)图象的初步观察结果来看 ,植物的 (诱导 )超弱发光与光形态建成和光合作用等生长代谢过程密切相关 (李德红等 ,1998)。我们在此工作的基础上 ,利用自行研制的超弱发光图象探测系统对叶绿体的超弱 (延迟 )发光进行了研究 ,并初步探讨了温度和某些化学试剂对叶绿体超弱发光的影响。实验材料选用白菜 (ＢｒａｓｓｉｃａｐｅｋｉｎｅｎｓｉｓＲｕｐｒ .)叶片 ,按通常的方法分离纯化叶绿体 ,经相应处理后分别装于比色皿中 ,按前文的方法观测其超弱发光。叶绿体无论…     

玉米果穗超弱发光特性的研究

玉米果穗的超弱发光特性与籽粒成熟度及籽粒着生部位有关。随着成熟时水分的散失和干物质的积累,发光由强到弱,成熟期为发光最低值。超弱发光可反映出玉米籽粒营养物质的转化动态。试验证明玉米果穗不同发育阶段的生理代谢与超弱发光密切相关。     

激光—静电磁场对水稻萌发过程超弱发光影响研究

１０．５ｍＷ Ｈｅ－Ｎｅ激光,３５００ｖ／ｃｍ静电场,０．４１Ｔ的恒磁场分别处理水稻种子,可使种子萌发过程中超弱发光不同程度增加。萌发种子经５℃低温胁迫后,发光值明显降低。     

Mn-SOD对CHO细胞电离辐射敏感性的影响

近年来的研究发现,IL-1和TNF是重要的辐射防护因子,因IL-1和TNF都能选择性诱导Mn-SOD的高度表达,因此认为Mn-SOD可能有辐射防护作用.通过转染有义和反义Mn-SOD cDNA于CHO细胞,进一步说明了Mn-SOD在抗电离辐射损伤中的作用.研究表明,转染有义Mn-SOD cDNA可降低细胞对电离辐射的敏感性, 而转染反义Mn-SOD cDNA的细胞克隆对电离辐射的敏感性升高.     

淡水鱼超微弱光子辐射的实验研究

采用一台高灵敏的生物活体单光计数系统对淡水鱼的主要超微弱发光特性进行了研究.淡水鱼的各种不同脏器的光子辐射强度数值为3.6—97.3CPS.发射光谱的最大值接近640nm处和460nm附近.实验结果表明,超微弱光子辐射的总强度随所测的时间而变化,加入UOUO_2~( )离子之后,其发光强度下降.     

人体血液的超微弱发光研究

采用一台高灵敏的单光子计数系统,研究了108例人体血液的超微弱光子辐射.结果表明:正常人血液的发光值平均每秒每平方厘米的计数在29.9水平内波动.血液的发光强度和供血者的年龄、性别有关.在选定的实验条件下,癌症患者血液的发光强度明显高于对照组,尤以肝、卵巢癌症患者显著.这一结果意味着血液的超微弱发光探测,有可能用于癌症的早期诊断.但对临床实践来说,血清的发光将更为有用.     

THE EFFECT OF IONIZING RADIATION UPON MITOCHONDRIA OF THE CENTRAL NERVOUS SYSTEM

After irradiation of rats with a linear electron accelerator, the respiratory rate in rat brain mitochondria was studied in the presence of substrate + ADP and after the conversion of ADP → ATP. After 20,000 rads of irradiation to the head there was a transient diminution of mitochondrial respiratory control when glutamate was used as the substrate, but no changes were observed when succinate was the substrate. Irradiation with 10,000 rads had no effect upon respiratory control. The addition of NADH₂ to irradiated mitochondria had no effect upon mitochondrial respiration. Irradiation of the brain with 20,000 rads failed to produce mitochondrial peroxidation or swelling, even in the presence of FeNH₄(SO₄)₂ or ascorbate. The slight changes in respiratory control of brain mitochondria following irradiation is in marked contrast to the susceptibility of mitochondria from other organs. The comparative radioresistance of brain mitochondria may be the result of greatly diminished radiation-induced peroxidation of cerebral mitochondrial membranes.     

THE KINETICS OF EXOSMOSIS OF WATER FROM LIVING CELLS

1. The rate of exosmosis of water was studied in unfertilized Arbacia eggs, in order to bring out possible differences between the kinetics of exosmosis and endosmosis. 2. Exosmosis, like endosmosis, is found to follow the equation See PDF for Equation, in which a is the total volume of water that will leave the cell before osmotic equilibrium is attained, x is the volume that has already left the cell at time t, and k is the velocity constant. 3. The velocity constants of the two processes are equal, provided the salt concentration of the medium is the same. 4. The temperature characteristic of exosmosis, as of endomosis, is high. 5. It is concluded that the kinetics of exosmosis and endosmosis of water in these cells are identical, the only difference in the processes being in the direction of the driving force of osmotic pressure.     

THE EFFECT OF CERTAIN ELECTROLYTES AND NON-ELECTROLYTES ON PERMEABILITY OF LIVING CELLS TO WATER

1. Permeability to water in unfertilized eggs of the sea urchin, Arbacia punctulata, is found to be greater in hypotonic solutions of dextrose, saccharose and glycocoll than in sea water of the same osmotic pressure. 2. The addition to dextrose solution of small amounts of CaCl₂ or MgCl₂ restores the permeability approximately to the value obtained in sea water. 3. This effect of CaCl₂ and MgCl₂ is antagonized by the further addition of NaCl or KCl. 4. It is concluded that the NaCl and KCl tend to increase the permeability of the cell to water, CaCl₂ and MgCl₂ to decrease it. 5. The method here employed can be used for quantitative study of salt antagonism.     

THE EFFECT OF SALT CONCENTRATION OF THE MEDIUM ON THE RATE OF OSMOSIS OF WATER THROUGH THE MEMBRANE OF LIVING CELLS

1. Using the unfertilized egg of the sea urchin, Arbacia, as osmometer, it was found that the rate with which water enters or leaves the cell depends on the osmotic pressure of the medium: the velocity constant of the diffusion process is higher when the cell is in concentrated sea water, and lower when the sea water medium is diluted with distilled water. Differences of more than tenfold in the value of the velocity constant were obtained in this way. When velocity constants are plotted against concentration of medium, a sigmoid curve is obtained. 2. These results are believed to indicate that cells are more permeable to water when the osmotic pressure of the medium is high than when it is low. This relation would be accounted for if water should diffuse through pores in a partially hydrated gel, constituting the cell membrane. In a medium of high osmotic pressure, the gel is conceived to give up water, to shrink, and therefore to allow widening of its pores with more ready diffusion of water through them. Conversely, in solutions of lower osmotic pressure, the gel would take up water and its pores become narrow.     

细菌防护液对照射小鼠脾脏细胞生物学效应的影响

目的:探讨细菌防护液(BPL)与受照小鼠脾脏细胞生物学效应的关系。方法:应用流式细胞仪((FCM)检测细胞的凋亡指数和免疫参数(CD 4、CD 8、NK)。结果:BPL能够降低细胞凋亡率(P<0.01),同时能够提高细胞的增殖率(P<0.05)。其作用机制可能与提高NK细胞活性和CD 4、CD 8数量有关。结论:本研究进一步证实,BPL对辐射损伤细胞有一定的保护作用,为临床应用提供科学数据。