鱼腥藻7120细胞液泡内含物的初步测定

对鱼腥藻7120细胞液泡内含物中4种水溶性的物质进行了测定,液泡中4种物质占整个细胞中4种物质的比例分别为:蛋白质:14.1％;还原糖:34.4％;核酸:28.5％;藻青蛋白12.1％。     

无机盐诱导鱼腥藻 595 (Anabaena sp.595)的细胞学效应

鱼腥藻595(Anabaena sp．595)在0．05mol／L钾、钠、铵的盐酸盐、硝酸盐、硫酸盐和磷酸盐的诱导下,2d后即出现显著的细胞学效应：细胞体积增大,明显液泡化;少数细胞发生横向和不均等分裂;藻丝片段化,异形胞分化率相对提高。其中,铵盐培养的藻丝细胞内出现特异的浓缩颗粒状区域。钙盐、镁盐也诱导类似细胞学变化,但作用较弱。在含0．1mol／L NaO的培养基中长期培养,细胞出现周期性分化行为,开始细胞膨大并液泡化,以后色素质重新充满细胞,液泡消失,然后细胞分裂至正常细胞大小,成为接近正常的藻丝,但接着又膨大液泡化,如此进入新的周期过程。     

盐胁迫对柱胞鱼腥藻细胞结构和固氮作用的影响

在含KCl的条件下培养,柱胞鱼腥藻细胞膨大,球形化,色素质靠向细胞一侧,另一侧变成无色透明区。电镜检查,无色透明区形成液泡。此种结构改变是可逆的,CaCl2可抵消KCl的这种作用。在含KCl的无氮培养基中培养,柱胞鱼腥藻生长迟缓,细胞黄化,乙炔还原法测定固氮活性下降95％。     

无机盐诱导鱼腥藻 595 (Anabaena sp.595)的细胞学效应

鱼腥藻 595 (Anabaenasp. 595)在0.05 mol/L钾、钠、铵的盐酸盐、硝酸盐、硫酸盐和磷酸盐的诱导下,2 d后即出现显著的细胞学效应：细胞体积增大,明显液泡化;少数细胞发生横向和不均等分裂;藻丝片段化,异形胞分化率相对提高。其中,铵盐培养的藻丝细胞内出现特异的浓缩颗粒状区域。钙盐、镁盐也诱导类似细胞学变化,但作用较弱。在含 0.1 mol/L NaCl的培养基中长期培养,细胞出现周期性分化行为,开始细胞膨大并液泡化,以后色素质重新充满细胞,液泡消失,然后细胞分裂至正常细胞大小,成为接近正常的藻丝,但接着又膨大液泡化,如此进入新的周期过程。     

盐胁迫对柱胞鱼腥藻细胞结构和固氮作用的影响

在含ＫＣｌ的条件下培养,柱胞鱼腥藻细胞膨大,球形化,色素质靠向细胞一侧,另一侧变成无色透明区。电镜检查,无色透明区形成液泡。此种结构改变是可逆的,ＣａＣｌ２可抵消ＫＣｌ的这种作用。在含ＫＣｌ的无氮培养基中培养,柱胞鱼腥藻生长迟缓,细胞黄化,乙炔还原法测定固氮活性下降９５％。     

鱼腥藻7120细胞液泡内含物的初步测定

对鱼腥藻7120细胞液泡内含物中4种水溶性的物质进行了测定,液泡中4种物质占整个细胞中4种物质的比例分别为：蛋白质：14．1％;还原糖：34．4％;核酸：28．5％;藻青蛋白12．1％。     

重金属及微量元素诱导蓝藻形成液泡*

鱼腥藻595(Anabaena sp.595)、织线藻246(Plectonema boryanum 246)和伪枝藻248(Scynetonema hofmanni 248)在两种重金属汞、镉和两种微量元素铜、锌诱导下,藻丝细胞均能发生膨大、液泡化现象。不同重金属及微量元素对3种蓝藻液泡化诱导作用强弱程度不同。汞的诱导作用明显强于镉、铜和锌,0．1μmol／L汞可诱导3种蓝藻发生液泡化。采用压片法均观察到诱导形成的液泡,液泡在相差显微镜下显示为圆球形,基本透明。     

有机碳化合物对鱼腥藻7120生长的影响

在培养基中添加多种有机碳化合物对鱼腥藻7120进行培养。结果表明,葡萄糖的存在能明显地促进细胞的生长,但细胞仅能有限地利用葡萄糖;细胞混合营养生长的饱和光强约为80μEm^-2s^-1。乙酸、蔗糖、乙醇和甘油对细胞生长的影响不很显著,乳酸、柠檬酸、谷氨酸和甘氨酸表现出明显的抑制作用。鱼腥藻7120不能利用葡萄糖进行化能异养生长和光激活的化能异养生长,但有轻微的光异养现象。     

鱼腥藻PCC7120细胞液泡的初步研究

从保存３个月以上的老化培养物中直接检查到游离液泡。液泡为标准圆球状,完全透明,大小相差极为悬殊,多数大型液泡吞噬了数个衰老藻细胞。采用低渗酶解,渗透冲击,低渗酶解和渗透冲击相结合从培养３个月以上,２个月,１个月,１８ｄ,１０ｄ及２ｄ的藻丝细胞都分离到液泡。液泡略大于细胞,泡内无吞噬物。培养３ｄ的藻丝有１５％的细胞分离到液泡。其他多种蓝藻也分离到同样的液泡。     

转基因鱼腥藻7120适宜生长条件的初步研究

以前的研究报导了将人肿瘤坏死因子基因(TNF-α)成功转入鱼腥藻7120中,这项研究在实验室小规模范围内探讨了其转TNF-α基因鱼腥藻7120的适宜生长条件。结果表明,转基因鱼腥藻7120最适生长温度在25～30℃,最适pH7.0～7.5。不同光照强度下的净光合放氧速率测定结果表明,转基因鱼腥藻7120与野生型具有一致的光饱和点和光补偿点,且适合在10～700μE.m-2.s-1下生长。外加有机碳源(4g/L葡萄糖)一定程度上可以增加转基因鱼腥藻7120生长速度。对不同藻龄转基因鱼腥藻7120中TNF-α的累积量的检测发现:生长8d左右时转基因鱼腥藻7120中TNF-α累积量达到最大值。这将为产业化生产、适时收获转基因蓝藻提供理论指导,同时讨论了葡萄糖对转基因鱼腥藻7120代谢的调节。     

Measurement of live bacteria by Nomarski interference microscopy and stereologic methods as tested with macroscopic rod-shaped models.

A new method is proposed to measure bacterial cells under growth conditions. Bacterial cells, suspended in their growth medium, were attached to a cover slip with poly-L-lysine. The cover slip was inverted and placed on a glass microscope slide. To prevent dehydration of the medium, the edges of the cover slip were sealed to the microscope slide with clear fingernail polish. The bacteria on the slide were then quickly photographed with a Leitz light microscope, using Nomarski optics. The photographic negatives were then projected at a standard distance through a lens system, and the projected images of the whole cells were outlined by hand onto graph paper. The profile images so transcribed onto the graph paper were in effect transverse sections of each of the cells. Using stereologic grid and point counting techniques, the area of the cell transverse section as well as the perimeter or circumference of the transverse section were estimated. Formulae were developed so that both the volume and surface area of the whole cell could be ascertained from these area and circumference measurements. Since the efficacy of any measurements of surface area and volume of microscopic rod-shaped bacterial cells could be questioned, macroscopic rod-shaped models were used to test the theory and formulae and to compare this method with other commonly used cell-sizing techniques. This technique could be used in any study of bacterial cell size or changes in cell size (e.g., osmotic shifts).     

Measurement of live bacteria by Nomarski interference microscopy and stereologic methods as tested with macroscopic rod-shaped models

A new method is proposed to measure bacterial cells under growth conditions. Bacterial cells, suspended in their growth medium, were attached to a cover slip with poly-L-lysine. The cover slip was inverted and placed on a glass microscope slide. To prevent dehydration of the medium, the edges of the cover slip were sealed to the microscope slide with clear fingernail polish. The bacteria on the slide were then quickly photographed with a Leitz light microscope, using Nomarski optics. The photographic negatives were then projected at a standard distance through a lens system, and the projected images of the whole cells were outlined by hand onto graph paper. The profile images so transcribed onto the graph paper were in effect transverse sections of each of the cells. Using stereologic grid and point counting techniques, the area of the cell transverse section as well as the perimeter or circumference of the transverse section were estimated. Formulae were developed so that both the volume and surface area of the whole cell could be ascertained from these area and circumference measurements. Since the efficacy of any measurements of surface area and volume of microscopic rod-shaped bacterial cells could be questioned, macroscopic rod-shaped models were used to test the theory and formulae and to compare this method with other commonly used cell-sizing techniques. This technique could be used in any study of bacterial cell size or changes in cell size (e.g., osmotic shifts).     

A new gas vacuolated heterotrophic rod from freshwaters

Summary A gas vacuolated rod was isolated from the oxygen-depleted zone of a eutrophic lake. It is a non-motile, euryoxic, gram negative heterotroph that grows slowly under all conditions tested. The vesicles of the gas vacuoles of the bacterium revealed by the electron microscope resemble those of other gas vacuolate prokaryotes. The taxonomy of the isolate is discussed but no names have been proposed.ESE Pub. No. 278.     

The classic Golgi apparatus and vacuoles

The dense vacuoles, considered to be the classic Golgi apparatus in the root meristem ofFagopyrum, were studied by the following methods: 1. Impregnation methods for the demonstration of the Golgi apparatus, 2. cytochemical methods, 3. electron microscopic methods in the light microscope and 4. the electron microscope. A comparison was made with the classic Golgi apparatus in animal cells in the light and electron microscope. Dense vacuoles inFagopyrum and also evidently in other plants, were taken for the classic Golgi apparatus on account of their morphological similarity to the Golgi apparatus in animal cells on impregnation with silver and osmium and their staining preperties with lipoid methods. Dense vacuoles differ from the classic Golgi apparatus in other chemical properties, such as content of phenol substances, etc. No formations were found in animal cells which were similar to dense vacuoles on investigating by electron microscopy. In the electron microscope dense vacuoles have the appearance of derivatives of the normal light vacuoles known in plant cells. They therefore belong to vacuome of plant cell and cannot be analogous to the classic Golgi apparatus in animal cells. Thus the use of the term Golgi apparatus for dense vacuoles is not well founded. A comparison was made of fixation and impregnation used in the light microscope with fixation in the electron microscope. After fixation with permanganate, dense vacuoles have the same shape as after impregnation. After fixation with permanganate, they stain an intense black in the same way as after impregnation with silver and osmium. The form of the vacuoles is dependent on the fixation used. The comparison was made in the light microscope.     

The organization and structure of nerve and muscle in the jellyfish Cyanea capillata (coelenterata; scyphozoa)

The perirhopalial tissue and swimming muscle of Cyanea were examined with light microscopical and electron microscopical techniques. The perirhopalial tissue is a thin, triangular septum found on the subumbrellar surface of the animal. It separates part of the gastric canal system from the surrounding seawater, and is bound on two sides by radial muscle bands and on the third, the shorter side, by a rhopalium and the margin of the bell. The ectoderm of the perirhopalial tissue is composed of large, somewhat cuboidal, vacuolated, myoepithelial cells. The muscle tails of these cells form a single layer of radial, smooth muscle. Neurons of the “giant fiber nerve net” (GFNN), which form an extensive net over the perirhopalial tissue, lie at the base of the vacuolated portion of the myoepithelial cells. These neurons are visible in living tissue. The morphology of individual GFNN neurons was examined following intracellular injection of the fluorescent dye Lucifer Yellow. The neurons are usually bipolar and free of branches. At the electron microscope level, one usually finds that the GFNN neurons contain large vacuoles. The other characteristic feature of these cells is that they form symmetrical, or nonpolarized, synapses; that is, synaptic vesicles are found on both sides of the synapse. The swimming muscle is striated and composed of myoepithelial cells. Each myoepithelial cell has several muscle tails, and those of adjacent cells are linked to gether by desmosomes. The endoderm of the perirhopalial tissue also was examined. This investigation of the organization and ultrastructure of the perirhopalial tissue and surrounding muscle was undertaken to provide essential background information for an ongoing physiological study of the GFNN neurons and their synapses.     

Isolation and chemical characterization of gas-vacuole membranes fromMicrocystis aeruginosa Kuetz. emend. Elenkin

Summary A method involving penicillin treatment was developed to osmotically lyse the cells of the blue-green alga,Microcystis aeruginosa Kuetz. emend. Elenkin, and release the pressure-sensitive gas vacuoles intact. The gas vacuoles were purified by liquid-polymer partitioning or by macromolecular sieving and centrifugation. The degree of purification of the gas vacuoles was followed by observation in the electron microscope and by the use of C¹⁴-labeled vacuolated and nonvacuolated strains ofM. aeruginosa. The gas-vacuole membrane is composed of only protein consisting of 10% basic, 18% acidic and 52% non-polar amino acids.Supported by U.S. Atomic Energy Commission, Contract No. AT(11-1)-1338.     

声化学激活血卟啉诱导艾氏腹水肿瘤细胞凋亡

本实验采用频率为2．0MHz，声强分别为1．0w／cm^2、1．5w／cm^2、2．0w／cm^2等不同参数，研究超声激活血卟啉对艾氏腹水肿瘤细胞的杀伤作用和诱导肿瘤细胞凋亡现象。通过扫描电镜、透射电镜以及荧光显微镜观察受损后细胞形态结构的变化，主要表现为细胞微绒毛的减少，胞膜结构和通透性的改变，细胞器的受损以及核物质的分解、丢失；同时发现处理后的肿瘤细胞有核物质凝集、趋边排列以及凋亡小体的形成等细胞凋亡特征。研究中首次发现声化学激活血卟啉在对艾氏腹水肿瘤细胞杀伤的同时，也能诱导艾氏腹水肿瘤细胞发生凋亡，提示在声动力疗法中并存着对癌细胞的直接杀伤和通过诱导癌细胞凋亡的两种抗癌途径。     

Electron microscopy of free-floating cells: thin-layering technique, and selection of individual cells for ultramicrotomy.

A rapid and accurate procedure for electron microscopy of individual cells from suspensions (blood, peritoneal exudate, etc.) is described. After fixation of the sample with standard techniques, the particulate constituents are suspended in buffered 5% bovine serum albumin, thin-layered by gravity on clear supports (cover glasses or polyester slips) in which an orientation grid had been scored, and then immobilized by exposure of the preparations to acrolein vapors. The specimens are examined for cells of interest under a light microscope using interference or phase contrast; individual cells to be sectioned are documented in three photomicrographs taken at different magnifications. After this the specimens are embedded like ordinary cover slip preparations. When examining the face of the polymerized block under a light microscope, the position of the selected cell beneath the orientation grid relief can readily be relocated by the aid of the pre-embedding reference micrographs.     

Microscopy with Plastic Substitutes for Cover Glasses

To determine whether plastic substitutes for cover glasses on microscope slides affect the performance of the microscope, their optical constants were determined. The plastic covers and glass cover glasses were mounted also on silvered slides to form Star Test Plates which were studied by competent observers. The thicker plastic cover glasses, now on the market, are satisfactory when mounted to give a plane surface. Optically inhomogeneous materials, of irregular thickness, those that curl or do not have plane surfaces, adversely affect the performance of the microscope and should not be used. Since the substitutes are softer than glass they must be protected from abrasion. It is recommended that thicknesses of 0.18 mm., and none outside of a range of 0.12 to 0.20 mm. be used. For critical observation with unimmersed objectives of high aperture, best results are obtained with the correction collar set at the position corresponding to the actual thickness of the cover slip, just as would be done with glass cover glasses.