绒毡层及小孢子发育研究的扫描电镜样品制备

锇酸-二甲基亚砜—锇酸冷冻割断法制备的样品,在扫描电镜下,可观察绒毡层及小孢子发育过程,细胞形态保存良好,结构清晰,立体感强,为用扫描电镜研究植物细胞结构提供了一个有应用价值的方法。     

不同固定方法对植物细胞扫描电镜观察用冷冻断裂样品的影响

用冷冻断裂法在扫描电镜下研究了洋葱(Allium cepa)根端分生组织细胞内部的三维结构。采用了两种固定方法。冷冻断裂前只用1％锇酸固定的材料容易在细胞质和核之间断开,而用卡诺固定液(无水乙醇:冰醋酸3:1)前固定,然后再用1％锇酸固定的材料容易使细胞核断裂。前一固定方法适于研究细胞质的内部结构(细胞骨架的纤维、线粒体、内质网等及其三维分布关系):后一固定方法适于研究核内结构(染色质、核仁、核基质纤维)的三维形象,特别是核仁纤维中心染色质的三维结构。     

杨属的分泌柱头：发育,细胞化学,超微结构及其与组间杂交不亲和性的关系

研究了胡杨、银白杨、小叶杨、大叶杨和欧洲黑杨的柱头。扫描电镜显示：分泌物存在于胞间隙、多细胞乳突的缝隙和接受表面。用黄丹Ⅲ和金胺Ｏ染新鲜柱头可见分泌物的释放和运动。戊乙醛－锇酸固定柱头,石蜡和半薄切片显示分泌物的脂类性质。透射电镜显示柱头表面乳突细胞的腺质特征－丰富的粗糙和光滑内质网、多聚核糖体、发育良好的具分泌泡的高尔基体。     

贯叶金丝桃叶中分泌细胞团的超微结构

随着贯叶金丝桃( Hypericum perforatum L.)叶中分泌细胞团的发育,其细胞中质体的数量和体积逐渐增大,但一些质体局部出现解体,大量的深色管状结构和小泡出现在退化质体的周围,有些小泡与液泡融合,并将其内容物释放至液泡中,导致液泡中出现大量的多泡结构、多膜结构和嗜锇滴.同时,高尔基体分泌小泡进入液泡.然而,当分泌细胞团发育成熟后,分泌细胞被含有灰色均匀的分泌物(金丝桃素)的大液泡所占据,嗜锇滴消失.表明嗜锇滴可能是金丝桃素的前体物,来源于退化的质体.出现于质体和嗜锇滴之间的内质网和高尔基体可能也参与了金丝桃素前体物的合成和细胞内的转运.     

银杏叶发育过程的解剖结构观察

利用半薄切片、扫描电镜和透射电镜技术,对不同发育时期的银杏叶片解剖结构变化进行连续观察.结果显示:(1)展叶期叶片无栅栏组织和海绵组织分化,细胞排列紧密;展叶后叶肉分化为栅栏组织1~2层,细胞呈长椭球形,海绵组织发达,细胞呈横向排列的椭球形,并形成通气系统;衰老期部分海绵组织细胞变小,并纵向排列,通气系统发达.(2)除叶基和叶缘外,成熟叶片的维管束直径基本相同,维管束鞘发达.(3)早期叶片上表皮有较多气孔分布,展叶后气孔密度迅速降低;下表皮气孔数量较多,但气孔密度随叶片的成熟逐渐下降.(4)叶绿体类囊体在展叶期结构简单,常含1~2个较大淀粉粒;生长期类囊体结构逐渐完善,淀粉粒较少,无嗜锇滴;衰老期类囊体瓦解,嗜锇滴大量累积.     

贯叶金丝桃叶中分泌细胞团的超微结构

随着贯叶金丝桃（Hypericum perforatum L.)叶中分泌细胞团的发育,其细胞中质体的数量和体积逐渐增大,但一些质体局部出现解体,大量的深色管状结构和小泡出现在退化质体的周围,有些小泡与液泡融合,并将其内容物释放至液泡中,导致液泡中出现大量的多泡结构,多膜结构和嗜锇滴。同时,高尔基体分泌小泡进入液泡。然而,当分泌细胞团发育成熟后,分泌细胞被含有灰色均匀的分泌物（金丝桃素）的大液泡所占据,嗜锇滴消失。表明嗜锇滴可能是金丝桃素的前体物,来源于退化的质体。出现于质体和嗜锇滴之间的内质网和高尔基体可能也参与了金丝桃素前体物的合成和细胞内的转运。     

支原体膜的结构与功能——Ⅱ、鸡败血症支原体细胞及细胞膜超精细结构

用负染、投影、超薄切片电镜技术研究鸡败血症支原体S_6细胞及细胞膜的超精细结构。结果表明,鸡败血症支原体S_6和其它类型支原体一样,具有多形态特征。细胞直径约为0.6微米。鸡败血症支原体细胞一端有小疱结构,此为其独特形态。用低渗法破碎鸡败血症支原体S_6细胞分离细胞膜,当细胞培养时间为36小时,可获较纯净的膜制品。分离出的膜结构为空囊状,有时在膜囊一端可见小疱状结构。用戊二醛与四氧化锇先后固定膜和四氧化锇单固定法进行比较,发现四氧化锇单固定可获更清楚的三层膜结构。     

聚乳酸聚乙醇酸膜、聚β羟基丁酯膜和胶原膜三种材料的相容性探讨

目的 评价聚乳酸聚乙醇酸膜、聚β羟基丁酯膜和胶原膜的结构、生物相容性及其在组织工程血管中的应用前景.方法 HE、胶原染色,扫描电镜观察材料的结构.新西兰兔15只皮下植入材料,于4、6、8和12周取出观察其组织反应和降解情况.将犬股动脉间质细胞种植于聚乳酸聚乙醇酸膜、胶原膜上,观察其形态.结果 聚乳酸聚乙醇酸膜、聚β羟基...     

烟草腺毛发育过程中叶绿体形态学研究

应用荧光显微技术和电镜技术,对不同发育时期烟草叶面腺毛的叶绿素荧光和叶绿体结构进行了比较研究.结果发现,在腺毛发育初期,腺头细胞叶绿素荧光明显,叶绿体类囊体结构清晰;随着腺头细胞的分裂和生长,叶绿素荧光逐渐增强,叶绿体数目逐渐增多,类囊体发达,嗜锇颗粒产生;在腺毛发育成熟以后,叶绿素荧光减弱,类囊体膜降解,嗜锇颗粒增多;随着腺毛的分泌活动增强,叶绿体完全降解,磷脂双层膜消失,嗜锇颗粒扩散到细胞质中,并最终聚集在细胞质膜附近.     

施肥对烟草腺毛叶绿体形态结构的影响

以烤烟K326为材料,在盆栽条件下分别施用纯有机肥和无机肥,在烟株旺长期和成熟期对叶面腺毛进行显微和超微结构观察,以明确肥料对烟草叶面腺毛生长发育的影响,结果显示:移栽后50 d,荧光下观察有机肥处理下腺头细胞叶绿素荧光强度较无机肥强烈,腺头细胞内叶绿体结构完整,类囊体基粒片层发达,嗜锇颗粒大而多;无机肥处理的细胞内叶绿体少,嗜锇颗粒较小,数量也较少.移栽后70 d,有机肥处理腺毛头细胞叶绿体双层膜结构依然完整,但类囊体基粒片层结构已经解体,其中积累大量黑色嗜锇颗粒;此时无机肥处理腺毛头细胞叶绿体结构完整,仍可清晰看到类囊体基粒片层仅含少量嗜锇颗粒.推测有机肥处理在初期促进了烟草腺毛细胞叶绿体的发育和叶绿素的合成、积累,在后期,促进叶绿素及内膜系统的降解,并有利于亲脂类物质的合成和积累,从而对腺毛分泌物积累和烟叶香气品质形成具有积极影响.     

Structural study of anhydrous tendon chitosan obtained via chitosan/acetic acid complex

The molecular structure and packing arrangement of anhydrous tendon chitosan was determined by the X-ray fibre diffraction method together with the linked-atom least-squares refinement technique. The specimen was prepared from chitosan/acetic acid complex which was obtained by exposing tendon chitosan to acetic acid vapour at room temperature for several days. There is high degree of orientation and crystallinity compared with the specimen obtained by the annealing method. Two chitosan chains are present in an orthorhombic unit cell of dimensions a = 8.26(2), b = 8.50(1), c (fibre axis) = 10.43(2) A and space group P2(1)2(1)2(1). The 2-fold helical chain is stabilised by O3 triple bond O5 hydrogen bond with the gt orientation of O6. There are direct hydrogen bonds (N2 triple bond O6) between adjacent chains along the a-axis, which makes a sheet structure parallel to the ac-plane. On the other hand, no hydrogen bond is found between the sheets.     

Analysis of cytokinetics by means of Feulgen cytofluorometry combine with 3H-thymidine autoradiography

DNA cytofluorometry combined with autoradiography after pulse-labelling with ³H-TdR visualizes movement of the labelled cells along the cell cycle. If the specimen is fixed after an adequate waiting time, this method enables us to measure the absolute length of the S phase in a cell population with a single sampling. The method was applied for Yoshida sarcoma cells proliferating in the rat ascites. Using a single specimen fixed after 4 h waiting time, the shortest, the average, and the longest durations of S phase in the population were estimated at 5.8, 7.5 and 13 h, respectively. Measurement on a flash-labelled specimen gives the relative durations of G 1, S, G 2 and M. It is shown that, using these 2 samples, a complete cell cycle time analysis can be performed.     

Techniques in the preparation of a monolayer of gynecologic cells for automated cytology. An overview

The computer-assisted microscope demands rigid specifications for specimen preparation. This paper addresses the variety of techniques developed by researchers attempting to automatically screen uterine cervical specimens. These same techniques could also be utilized for specimens from other body sites. In contrast to the easily prepared routine Papanicolaou smear, these techniques can be broken down into various steps as follows: transport media, cellular disaggregation, cell number estimation, cell separation and specimen enrichment, cellular adhesion to glass slide and cell transfer onto the slide. Variations on the theme are contrasted among specimen preparation methods utilized by prominent research groups. The plea for a simpler preparation method or, hopefully, utilization of the routine Papanicolaou smear for computer-assisted microscopy is made.     

Fine needle aspiration cytology of clear cell sarcoma. Report of a case with immunocytochemical, immunohistochemical and ultrastructural studies.

Cytologic findings of clear cell sarcoma obtained by fine needle aspiration (FNA) of a tumor are described. The tumor probably originated in the retroperitoneal tissue, and the diagnosis was confirmed histologically by open biopsy. Percutaneous needle aspirates of the intraabdominal tumor and touch preparations obtained from the open biopsy specimen revealed numerous atypical cells with an extremely hyperchromatic nucleus, prominent nucleoli and clear cytoplasm. The cytoplasm was rich in glycogen. The immunocytochemical technique demonstrated S-100 protein and neuron-specific enolase in the cytoplasm, both of which were exhibited also in the histologic specimen. Clear cell sarcoma is a rare tumor of soft tissue, and to our knowledge, detailed cytologic appearances of this tumor obtained by FNA have not been reported. In addition, the present tumor was unique in location. It is possible to diagnose clear cell sarcoma accurately on an FNA cytologic specimen if the periodic acid-Schiff stain and immunocytochemical technique are utilized in addition to the routine Papanicolaou method.     

Sponge-Cell Culture? A Molecular Identification Method for Sponge Cells

Dissociated sponge cells are easily confused with unicellular organisms. This has been an obstacle in the development of sponge-cell lines. We developed a molecular detection method to identify cells of the sponge Dysidea avara in dissociated cell cultures. The 18S ribosomal RNA gene from a Dysidea avara specimen was sequenced and compared to eukaryotic 18S rDNA sequences picked up from a proliferating cell culture that originated from a dissociated Dysidea avara specimen. Our method proved unambiguously that this was not a sponge-cell culture. Therefore, it provides a valuable tool for further research on sponge-cell cultures.     

Application of the microarray technique to cell blocks

OBJECTIVE: To evaluate whether the technique ofmicroarray construction can be applied to paraffin-embedded cell block specinmens. STUDY DESIGN: We used a manual microarray method for construction of a well-aligned cell microarray. First we evaluated the cellularity of the cell block and assigned the cases to the null, low, moderate or high cellularity category. Second, based on the different cellularity, we constructed 25 specimen cylinders into 1 block. We used routine hematoxylin-eosin (H-E) stain and immunocytochemistry (ICC) on the slide. RESULTS: All cell microarray paraffin block shaping and specimen cylinder arraying were finished in 1 step, so the specimen cylinders and the paraffin blocks of the cell microarray could very easily be incorporated. No sample was lost during the H-E staining process. However, a few samples fell off partially during the ICC process. Additionally, we observed that the higher cellularity groups yielded a better outcome as compared to the lower cellularity groups. CONCLUSION: This study introduced a very simple and economical technique for the creation of cell microarrays from cell blocks. This procedure should acquaint cytopathologists with microarray technology and encourage its use.     

植物材料减数分裂染色体标本的快速制作

探索一种简便快速的植物材料减数分裂染色体标本制作技术,获得良好的减数分裂染色体标本以供原位杂交研究、遗传学实验教学等方面研究使用。以植物材料小麦、黑麦花药为材料,卡宝品红染色,冰冻揭片法制得减数分裂染色体标本,结果表明,这些用快速简便的方法获得的标本效果良好,染色体图像清晰,可较好的用于本科生实验教学、染色体分带、原位杂交等方面的研究。     

Membrane turnover in crab photoreceptors studied by high-resolution scanning electron microscopy and by a new technique of thick-section transmission electron microscopy

Summary Crab photoreceptors were examined after treatment by the osmium-DMSO-osmium method for high-resolution scanning electron microscopy. This technique of specimen preparation was also adapted for transmission electron microscopy, enabling sections up to 1 urn thick to be viewed in a conventional microscope at 75 kV. With appropriate pretreatment, some cytoskeletal elements can be visualised by both techniques. The methods were then used to investigate some of the daily changes known to occur in photoreceptor cell structure. Striking differences were found in the structure of Golgi bodies present in retinula cells during the synthesis and breakdown phases of the daily cycle of photoreceptor membrane turnover. Cyclic changes were also noticed in the mitochondria of retinula cells, and additional evidence was found for a previously proposed model of rhabdomeral microvillus formation.