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.     

Activity-dependent neural tissue oxidation emits intrinsic ultraweak photons

Living organisms have been known to spontaneously emit ultraweak photons in vivo and in vitro. Origin of the photon emission remains unclear, especially in the nervous system. The spontaneous ultraweak photon emission was detected here from cultured rat cerebellar granule neurons using a photomultiplier tube which was highly sensitive to visible light. The photon emission was facilitated by the membrane depolarization of neurons by a high concentration of K+ and was attenuated by application of tetrodotoxin or removal of extracellular Ca2+, indicating the photon emission depending on the neuronal activity and likely on the cellular metabolism. Furthermore, almost all the photon emission was arrested by 2,4-dinitrophenylhydrazine, indicating that the photon emission would be derived from oxidized molecules. Detection of the spontaneous ultraweak photon emission will realize noninvasive and real-time monitoring of the redox state of neural tissue corresponding to the neuronal activity and metabolism.     

Highly sensitive determination of transient generation of biophotons during hypersensitive response to cucumber mosaic virus in cowpea

The hypersensitive response (HR) is one mechanism of the resistance of plants to pathogen infection. It involves the generation of reactive oxygen species (ROS) which have crucial roles in signal transduction or as toxic agents leading to cell death. Often, ROS generation is accompanied by an ultraweak photon emission resulting from radical reactions that are initiated by ROS through the oxidation of living materials such as lipids, proteins, and DNA. This photon emission, referred to as 'biophotons', is extremely weak, but, based on the technique of photon counting imaging, a system has been developed to analyse the spatiotemporal properties of photon emission. Using this system, the dynamics of photon emission which might be associated with the oxidative burst, which promotes the HR, have been determined. Here, the transient generation of biophotons is demonstrated during the HR process in cowpea elicited by cucumber mosaic virus. The distinctive dynamics in spatiotemporal properties of biophoton emission during the HR expression on macroscopic and microscopic levels are also described. This study reveals the involvement of ROS generation in biophoton emission in the process of HR through the determination of the inhibitory effect of an antioxidant (Tiron) on biophoton emission.     

Oscillations in ultraweak photon emission of Acetabularia acetabulum (L.)

Ultraweak photon emission of dark-incubated A. acetabulum cells were measured with the use of a sensitive electronphotomultiplier of the Hamamatsu 550 type. The photon count series were subjected to Fourier analysis for 2-1020 sec period range. The average level of photon emission in samples containing 50 cells was approximately. 40% above background. Cell cultures were prepared at least 24 hr before the photon emission measurements and kept un-disturbed ("established cultures"). This paper reports results of Fourier analysis of a number of samples of Acetabularia cells. In a single population cells periodicity of light emission was not defined directly from Fourier transformation. A large number of analyses, however, if they are combined and compared with background data, reveal a cell-culture specific frequency pattern. The results suggest the idea that established cell-cultures are characterized by higher intensities of long period (minutes) oscillations occurs, while a relative decrease was observed in the short period (few seconds) range. The long period oscillations were not detected in cell cultures that were prepared within 1 hr before the photon emission measurements. It is concluded that Fourier analysis of ultraweak photon emission, even with relatively low signals, appears to be possible. It may serve as a non-invasive tool for monitoring the physiological state of cells, or for studying the control of intercellular dynamics.     

Discrimination between different types of low-level luminescence in mammalian cells: The biophysical radiation

Cellular low-level luminescence was measured after various disintegrative processes in brain cell preparations. In addition to known origins of low-level luminescence, e.g. oxygen radical reactions or enzymatic and non-enzymatic redox systems, a further source of photon emission is reported which is independent of external oxygen, oxygen radicals and enzyme activities. Vital cells from rat brain homogenates or pig oligodendrocytes could be kept for hours at 37 °C without any photon emission. Only after disintegrative processes a cellular photon emission could be induced. The maximal intensity of about 400 impulses/s/mg protein and a total radiation of about 6 × 10⁶ I/mg depended on the type of cells. The signal could be retained completely at 4 °C or in frozen samples. Heating (10 min, 90 °C) did not suppress the photon emission. Luminol and lucigenin did not amplify the signal as is usually observed in oxygen radical-producing cells. Non-specific radical scavengers as well as detergents suppressed the cellular photon emission completely. It is suggested that this cellular luminescence represents a biophysical radiation which originates from the interruption of an intermolecular radiationless energy transfer.     

植物幼苗原发性超弱光子成像的研究

采用光子计数成像系统（PIAS）对植物幼苗萌发过程的超弱发光进行观察。结果表明,自发光子长时间积累可形成二维图象;光子计数和采集图象均可得到植物体的自发发光;通过实验探测到幼苗的根,叶在同一平面图象有不同的发光表现;光子成像系统可客观地比较生物自发超弱发光,为进一步研究超弱发光机理提供实验基础。     

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.     

Linoleic acid-induced ultra-weak photon emission from Chlamydomonas reinhardtii as a tool for monitoring of lipid peroxidation in the cell membranes

Reactive oxygen species formed as a response to various abiotic and biotic stresses cause an oxidative damage of cellular component such are lipids, proteins and nucleic acids. Lipid peroxidation is considered as one of the major processes responsible for the oxidative damage of the polyunsaturated fatty acid in the cell membranes. Various methods such as a loss of polyunsaturated fatty acids, amount of the primary and the secondary products are used to monitor the level of lipid peroxidation. To investigate the use of ultra-weak photon emission as a non-invasive tool for monitoring of lipid peroxidation, the involvement of lipid peroxidation in ultra-weak photon emission was studied in the unicellular green alga Chlamydomonas reinhardtii. Lipid peroxidation initiated by addition of exogenous linoleic acid to the cells was monitored by ultra-weak photon emission measured with the employment of highly sensitive charged couple device camera and photomultiplier tube. It was found that the addition of linoleic acid to the cells significantly increased the ultra-weak photon emission that correlates with the accumulation of lipid peroxidation product as measured using thiobarbituric acid assay. Scavenging of hydroxyl radical by mannitol, inhibition of intrinsic lipoxygenase by catechol and removal of molecular oxygen considerably suppressed ultra-weak photon emission measured after the addition of linoleic acid. The photon emission dominated at the red region of the spectrum with emission maximum at 680 nm. These observations reveal that the oxidation of linoleic acid by hydroxyl radical and intrinsic lipoxygenase results in the ultra-weak photon emission. Electronically excited species such as excited triplet carbonyls are the likely candidates for the primary excited species formed during the lipid peroxidation, whereas chlorophylls are the final emitters of photons. We propose here that the ultra-weak photon emission can be used as a non-invasive tool for the detection of lipid peroxidation in the cell membranes.     

Endogenous enzyme reactions closely related to photon emission in the plant defense response

Lipoxygenase (LOX) and peroxidase (POD) reactions, which are involved in the production of reactive oxygen and radical species, are shown to be associated with ultraweak photon emission in plant defense mechanisms. These enzyme reactions induced high-level ultraweak photon emission in an in vitro reaction system. The application of LOX to sweet potato slices caused photon emission directly in plants. LOX substrate promoted photon emission in chitosan-treated sweet potato, and LOX inhibitor markedly suppressed this emission. Therefore, a LOX-related pathway, including LOX and other downstream reactions, is principally associated with photon emission in plant defense mechanisms.     

Light-induced photon emission by rat hepatocytes and hepatoma cells.

We have investigated spontaneous and light-induced photon emission of suspensions of rat hepatocytes and of HTC hepatoma cells. Rat hepatocytes exhibit spontaneous biophoton emission, but from hepatoma cells this was not detectable. In contrast, after irradiation with white light, the reemission intensity was found to be lower for hepatocytes than for the tumor cell line. Induced photon emission was neither influenced by anaerobiosis nor by the intactness of the cells. Cell-fractionation studies demonstrate that the induced photon emission was caused by the nuclear fraction and by isolated chromatin. Phenol-extracted DNA, however, has lost this capacity. Our data suggest that differences in the chromatin structure may explain the cell-specific induced photon emission.     

Light-Induced photon emission by rat hepatocytes and hepatoma cells

We have investigated spontaneous and light-induced photon emission of suspensions of rat hepatocytes and of HTC hepatoma cells. Rat hepatocytes exhibit spontaneous biophoton emission, but from hepatoma cells this was not detectable. In contrast, after irradiation with white light, the reemission intensity was found to be lower for hepatocytes than for the tumor cell line. Induced photon emission was neither influenced by anaerobiosis nor by the intactness of the cells. Cell-fractionation studies demonstrate that the induced photon emission was caused by the nuclear fraction and by isolated chromatin. Phenol-extracted DNA, however, has lost this capacity. Our data suggest that differences in the chromatin structure may explain the cell-specific induced photon emission.     

骆驼刺根瘤菌的超微结构研究

用透射电子显微镜研究骆驼刺根瘤中的根瘤菌。结果表明。在成熟的骆驼刺根瘤中,根瘤菌的大小、数量、形态、分布位置及精细结构随寄主细胞的发育程度不同而异。早期侵染细胞中,根瘤菌小,数量少,一般呈球形或椭球形,位于细胞壁附近及靠近核区的地方,没有聚磷酸盐颗粒和聚羟基丁酸。成熟侵染细胞中,根瘤菌个体较大,数量较多．多呈棒状,少数为球形或椭球形。有很多根瘤菌还呈现明显的“T”形、“Y”形或“V”形,菌体占满了整个细胞,这时的根瘤菌大多数含有聚羟基丁酸和聚磷酸盐颗粒。而在衰老的侵染细胞中,根瘤菌细胞质收缩,电子密度增高．形状变得很不规则,有的根瘤菌解体,呈现膜泡状结构,菌体中含有数量不等的聚羟基丁酸和聚磷酸盐颗粒。球状根瘤菌从侵染初期到侵染细胞裂解的整个阶段中都仔在。并且观察到的处于分裂状态的根瘤菌都是球状菌,因此可以推测骆驼刺根瘤中是以球状根瘤菌来进行增殖的。     

Spatial energy transfer with observation of bimolecular singlet oxygen emission using quantum dots as donors and zinc‐phthalocyanine as acceptors

This study reports the influence of CdSe–ZnS core–shell quantum dots (QDs) for formation of singlet oxygen using zinc‐phthalocyanine (ZnPc) dyes in colloidal solutions. Using a microluminescence surface scan technique it was possible to measure accurately the photon diffusion length, or photon mean free path, inside the medium. Analyses were performed for a range of QD concentrations. Photon diffusion length was assigned to the bimolecular singlet oxygen emission at 707 nm. Related singlet oxygen emission was predicted by observing quenching of the photon diffusion length measured at the specific oxygen emission as a function of QD concentration, being a nontrivial phenomenon related to the QD donors. Diffusion length measured at 707 nm increased with QD concentration; in the absence of QDs, as in pure ZnPc samples, the emission peak at 707 nm was not observed.     

Spontaneous and light-induced photon emission from intact brains of chick embryos

Photon emission (PE) and light-induced photon emission(LPE) of intact brains isolated from chick embryos have been measured by using the single photon counting device. Experimental results showed that the intensi-ty level of photon emission was detected to be higher from intact brain than from the medium in which the brain was immerged during measuring, and the emission intensity was related to the developmental stages, the healthy situation of the measured embryos, and the freshness of isolated brains as well. After white light illumination, a short-life de-layed emission from intact brains was observed, and its relaxation behavior followed a hyperbolic rather than an expo-nential law. According to the hypothesis of biophoton emission originating from a delocalized coherent electromagnetic field and Frohlich's idea of coherent long-range interactions in biological systems, discussions were made on the signifi-cance of photon emission in studying cell communication, biological regulation, living system'     

Generation of reactive oxygen species and photon emission from a browned product

The properties of photon emission arising from a browned product were investigated. The photon intensity of the browned product was proportional to the absorbancy at 420 nm, and was influenced by the amino acid structure. The fluorescence spectrum showed similar compounds in the browned product to be related with this photon emission. Superoxide and hydrogen peroxide contributed highly to this photon emission, and several redox compounds enhanced the photon intensity at appropriate concentrations. Our work suggests that the photon intensity was closely related to the reactive oxygen species (ROS) generated from the browned product, and this effect may be utilized to evaluate the function and quality of browned food.     

Imaging of Ultraweak Spontaneous Photon Emission from Human Body Displaying Diurnal Rhythm

The human body literally glimmers. The intensity of the light emitted by the body is 1000 times lower than the sensitivity of our naked eyes. Ultraweak photon emission is known as the energy released as light through the changes in energy metabolism. We successfully imaged the diurnal change of this ultraweak photon emission with an improved highly sensitive imaging system using cryogenic charge-coupled device (CCD) camera. We found that the human body directly and rhythmically emits light. The diurnal changes in photon emission might be linked to changes in energy metabolism.     

Cortical photons in early development of frog eggs: comparative study of photon emission between nuclear division and cytoplasmic fission.

In the study of cell division in the early development of frog eggs, cortical photon emission was investigated by converting small light emission from living cells into digital pulses of potentials and recording the integrals of these pulses (analog method), counting the number of pulses (photon-counting method), and counting the number of integrated pulses (improved photon-counting method). By the analog and improved photon-counting methods, changes in photon emission due to cell division could be clearly detected. The emitted light increased about 5.10(-19)W at the start of a cleavage furrow. Rapid changes in chemical reactions causing photon emission were compared during nuclear division and cytoplasmic phases. This emission occurred mainly in cytoplasmic fission, the rate being greater than in nuclear division by a factor of about 2.9. Chemical reaction rates were shown to differ according to bulk emission, thus indicating the mechanisms for the reactions to also differ.     

Expression of Rhizobial Nitrogenase: Influence of Plant Cell-Conditioned Medium

Conditioned medium was obtained from suspension cultures of soybean (Glycine max L. Merrit) cells after incubating them for 4 to 8 days with rhizobia which were separated from the soybean cells by two dialysis bags, one within another. This conditioned medium from the plant cell side (PCM) of the two membranes was used to elicit and influence nitrogenase activity (acetylene reduction) in rhizobia. When conditions for obtaining PCM from the soybean cell suspension cultures were varied, it could be shown that freshly grown rhizobia were able to induce active compounds in the PCM. These compounds caused acetylene reduction activity in test rhizobia under conditions where control rhizobia, containing various substrates, showed little or no acetylene reduction activity. Rhizobia that were already capable of acetylene reduction could not induce such compounds in the PCM when this was included with test rhizobia. The PCM from soybean cultures was also found to aid the expression of nitrogenase activity in suspension cultures of rhizobia normally associated with either peas, lupins, broad beans, or clovers. This is the first communication indicating nitrogenase activity in freeliving cultures for various species of rhizobia.     

Ultraweak photon emission in model reactions of the in vitro formation of eumelanins and pheomelanins

Ultraweak luminescence in the spectral region 300-660 nm is generated in the enzymatic (tyrosinase EC.1.14.18.1) and autooxidative polymerization of L-DOPA, 5-S-cysteinyl-DOPA, and L-DOPA + cysteine to eumelanins and pheomelanins, respectively. Using sensitive calibrated single photon counting equipment, the photon emission intensity I and quantum yield phi have been measured: I = 10-100 h nu/s cm3, phi less than or equal to 10(-13) for enzymatic reactions, and I = 500-3000 h nu/s cm3, phi greater than or equal to 5 x 10(-12) for autooxidative ones. 5-S-cysteinyl-DOPA and cysteine exhibit diminished I and phi-values relative to DOPA. Tests with chemiluminogenic probes-luminol and lucigenin, SOD, catalase, peroxidase, H2O2, and spectrophotometric measurements indicate that photon emission is associated with degradative oxidations of melanin subunits by means of active oxygen species as H2O2 and O2.     

Competitiveness of a <Emphasis Type="Italic">Bradyrhizobium</Emphasis> sp. Strain in Soils Containing Indigenous Rhizobia

The success of rhizobial inoculation on plant roots is often limited by several factors, including environmental conditions, the number of infective cells applied, the presence of competing indigenous (native) rhizobia, and the inoculation method. Many approaches have been taken to solve the problem of inoculant competition by naturalized populations of compatible rhizobia present in soil, but so far without a satisfactory solution. We used antibiotic resistance and molecular profiles as tools to find a reliable and accurate method for competitiveness assay between introduced Bradyrhizobium sp. strains and indigenous rhizobia strains that nodulate peanut in Argentina. The positional advantage of rhizobia soil population for nodulation was assessed using a laboratory model in which a rhizobial population is established in sterile vermiculite. We observed an increase in nodule number per plant and nodule occupancy for strains established in vermiculite. In field experiments, only 9% of total nodules were formed by bacteria inoculated by direct coating of seed, whereas 78% of nodules were formed by bacteria inoculated in the furrow at seeding. In each case, the other nodules were formed by indigenous strains or by both strains (inoculated and indigenous). These findings indicate a positional advantage of native rhizobia or in-furrow inoculated rhizobia for nodulation in peanut.