大豆种子萌发过程中子叶细胞超微结构和ATP酶活性动态研究

采用磷酸铅沉淀的电镜细胞化学方法，研究大豆种子萌发过程中，子叶细胞超微结构变化与ATP酶活性的消长。子叶细胞的ATP酶活性主要定位在质膜。在种子萌发的0-3天，子叶细胞贮存蛋白质和油脂大量急剧降解，并快速转运到胚，质膜ATP酶活性较高。萌发的6-9天，子叶细胞内含物大部分消解，蛋白体膜相互融合形成大液泡，原质体开始有稀疏的片层结构，ATP酶活性渐弱至无。萌发第12天，原质体的片层堆叠成基粒，子叶细胞转为同化器官，制造养分，质膜再度呈现较强的ATP酶活性。子叶细胞质膜ATP酶活性反应子叶细胞生理代谢状态。     

氟中毒蚕中肠组织中钙结晶体的发现和作用

应用焦锑酸钾亚细胞定位技术研究氟中毒蚕中肠细胞钙离子变化动态，在透射电镜下观察到由多层膜结构组成的同心圆钙结晶体结构，这种结晶体的结构和数量随食下桑叶含氟量的增加而变化，与家蚕氟中毒有密切的关系。     

冬季沙冬青液泡中膜状内含物的超微结构研究

冬季沙冬青叶肉细胞中由于液泡膜内吞现象极其普遍，以致常常形成各种细胞质突起，并有丰富的颗粒状和纤维状物质及大量的膜状结构存在于液泡中。膜状结构大小不等，形态各异，膜层排列也不一样。有的相当紊乱，有的比较规则，有的甚至呈同心圆形。同心圆的内部膜层时而清楚，时而模糊，时而是一团电子密度很高的物质。在这些液泡中常有一种电子密度很高，近似圆形的内含物，它的表层中偶尔有膜状结构。冬季沙冬青液泡膜的大量内吞可能与沙冬青具有高度的抗寒性有关。     

樱桃番茄叶体细胞胚发生的组织细胞学观察

以樱桃番茄无菌苗叶片为外植体,在附加2.0 mg/L 6-BA+0.1 mg/L IAA的MS培养基上诱导培养,利用石蜡切片和透射电镜技术观察外植体体细胞胚发生过程中显微结构和超微结构的变化.显微观察结果表明,培养5天后,部分叶肉细胞通过脱分化而进入分裂,开始形成胚性细胞;13天后切口处可诱导出淡黄色胚性愈伤组织,继续...     

患者增殖体、扁桃体组织内尼曼-匹克细胞的超微结构观察

目的：观察尼曼-匹克病患者增殖体、扁桃体组织中的尼曼-克细胞的超微结构。方法：取增殖体、扁桃体组织做超薄切片，透射电镜下观察尼曼-匹克细胞的超微结构。结果：在透射电镜下，尼曼-匹克细胞呈圆形或椭圆形，细胞质丰富，其中有数量不等的嗜锇板层小体，呈板层状或同心圆状排列。细胞基底部，可查见单层或多层基底膜和细胞表膜下有少数吞饮小泡，具有内皮细胞形态特征。结论：尼曼-匹克细胞的细胞质内可见数量不等的嗜锇板层小体及基底部的单层或多层基底膜，为其特征性的结构，可作为电镜超微结构诊断及鉴别诊断的形态学依据。     

双包层光纤内包层形状对吸收效率的影响分析

在理想情况下，用二维几何光学对双包层光纤中的泵浦光传输路线进行分析，从而得出不同内包层形状下的吸收效率。圆形内包层有最低的吸收效率，破坏同心圆的圆对称性后吸收效率显著提高，如偏心圆结构有比同心圆大的吸收效率，矩形和D形内包层可以达到理论上100％的吸收效率。     

枸杞胚性细胞分化的超微结构研究

在植物体细胞胚发生过程中，体细胞转变为胚性细胞是细胞分化的转折点，因此对胚性细胞分化的研究进十分重要的。为此，本研究以枸札胚性细胞的分化和发育早期为重点，用半薄切片定位，进行超薄切片，以观察胚性细胞超微结构的特点。结果表明：（１）杞的胚性细胞多由愈伤组织表层的薄壁细胞分化而来；愈伤组织中不未分化的细胞体积大，细胞壁薄，形状不规则，一般都具有中央大液泡，核小，细胞质少，细胞器少。（２）胚性细胞呈卵圆     

感染番茄斑萎病毒和番茄环纹斑点病毒的植物叶片细胞病理变化观察

应用透射电子显微镜观察比较了番茄斑萎病毒（ TSWV）和番茄环纹斑点病毒（ TZSV）感病植物叶片的细胞超微结构,发现两种病毒在病变细胞内的形态及细胞病理变化特征相似,但病毒含量及细胞受损程度存在明显差异。与TSWV相比,TZSV侵染细胞的病变程度更为严重,叶绿体产生大的囊泡,片层结构被破坏,线粒体也发生囊泡化,而TSWV侵染的细胞内线粒体保存相对完好。高压冷冻－冷冻置换制备的样品细胞病理结构与常规化学固定的相似,但对膜结构的保存更加良好。该结果从细胞病理学上证明了TZSV在田间对农作物造成的危害更加严重。     

大菜粉蝶颗粒体病毒(PbGV)在病虫脂肪体细胞中诱发的环形片层结构

环形片层(Annulate lamellae简称AL),它常出现在生殖细胞或肿瘤细胞中,也出现在由于病毒感染所造成的细胞循环失常的细胞中。本文介绍PbGV在病虫脂肪体细胞中诱发的环形片层结构,指出伴随着病毒感染的全过程,感染细胞中始终存在有环形片层结构。     

荠菜胚柄细胞中质体和线粒体的形态变异

从早球胚期到心形期，观察到荠菜胚柄细胞中存在切面上呈环形、镰刀形、哑铃形和蝴蝶形等形状的质体。在早球胚期和球胚期，分别观察到荠菜胚柄细胞中的蝴蝶形、镰刀形、人字形和环开遥线粒体，推测形态变异的质体可能承担着分泌功能。线粒体的形态变异可能与外膜和内膜面积增加有关，而内膜面积的增加有利于胚柄细胞旺盛的呼吸活动和能量转换。     

银杏小孢子囊壁发育的超微结构观察

本文利用透射电镜、半薄切片等技术,对银杏小孢子囊壁的发育进行了观察和研究。银杏小孢子囊壁分为表皮、内壁、中层和绒毡层。(1)对小孢子囊壁的表皮、内壁和中层细胞的观察表明,小孢子母细胞时期,这些细胞均处于活跃的代谢和合成阶段,含有大量的细胞器如线粒体、高尔基体、内质网和核糖体等;减数分裂时期细胞的细胞质浓度逐渐降低,细胞内分布有大液泡,其中表皮细胞的液泡膜上形成大量贮藏蛋白,内壁细胞的细胞壁逐渐皱缩,中层细胞纵向拉伸;有丝分裂时期,细胞的细胞质逐渐降解,内壁细胞切向壁和径向壁均出现大量乳突状纤维加厚,中层细胞解体,最后仅剩残余。(2)绒毡层细胞属于分泌型,在小孢子母细胞时期细胞内的细胞器丰富,其中质体在减数分裂过程中达到高峰;游离小孢子时期,粗糙内质网达到最大,绒毡层开始形成乌氏体,最终结合到花粉外壁,参与花粉外壁的形成;有丝分裂后期,绒毡层通过自溶的形式解体。以上结果显示,银杏的小孢子囊壁在为花粉发育提供营养和保护作用方面起着重要作用。     

青少年特发性脊柱侧凸患者脊柱前后柱生长软骨的超微结构研究

探讨青少年特发性脊柱侧凸(adolescent idiopathic scoliosis,AIS)患者脊柱生长的特征,对12例AIS患者的前后柱生长软骨进行超微结构观察。结果显示12例AIS患者脊柱前后柱均有软骨内成骨,电镜下观察脊柱前柱(终板)软骨细胞呈圆形且表面有突起,胞浆内粗面内质网和线粒体丰富;后柱生长软骨细胞呈梭形细胞表面有突起,胞浆内粗面内质网和线粒体相对较少,细胞核有异染色质聚集。超微结构的观察有助于青少年特发性脊柱侧凸的病因学诊断研究。     

A Unique Microcracking Process Associated with the Inelastic Deformation of Haversian Bone

Since the discovery of the Haversian system in human bone over three hundred years ago, researchers have been wondering about its mechanical advantages. Despite positive experimental evidences on the intervention of Haversian systems in the fracture process, the contributions of Haversian systems to bone fracture have been obscure. Here a unique microcracking process accompanying the inelastic deformation of Haversian bone is reported that may shine light on its structural advantages over other bones. When compressed transversely, the concentric bone lamellae surrounding each Haversian canal allow multiple radial microcracks and arc‐shaped cracks to develop intralamellarly. Groups of circumferential arc‐shaped microcracks develop in high shear zones and radiate out in oblique directions from each Haversian canal. At the cortical bone level, where the Haversian systems are randomly distributed within the interstitial matrix, multiple nucleations and stable development of such arc‐shaped cracks happen to most Haversian systems progressively. As a result, Haversian bone is not sensitive to the presence of Haversian canals and demonstrates high inelastic strains at macroscopic level.     

Three-dimensional structure of intracellular membranous organelles in embryonic chick skeletal muscle cells in vitro revealed with scanning electron microscope

Using the freeze-polishing and osmium-maceration procedures, the ultrastructure of intracellular membranous organelles in embryonic chick skeletal muscle cells in vitro was investigated three-dimensionally with the scanning electron microscope (SEM). T-system tubules followed a tortuous course and possessed many warts. Some of these tubules could be traced to the sarcolemma. The sarcoplasmic reticulum (SR) had elaborate structures of a hexagonal pattern. By comparing the SEM images with those of ultrathin sections of myotubes impregnated with ferritin particles, the distinction between the T-system and SR was confirmed. Late in the culture, these two intracellular membranous systems were arranged periodically at right angles to the longitudinal axis of the myotubes. Round-shaped mitochondria were often arranged in chains connected with slender rods. Long rod-shaped mitochondria exhibited occasional branchings.     

克劳茨基棉组织培养胚胎发生与器官分化的扫描电镜观察

用扫描电镜观察克劳茨基棉不同类型的愈伤组织和胚状体。结果表明克劳茨基棉花药诱导产生的愈伤组织可分为胚性愈伤组织和非胚性愈伤组织两类；克劳茨基棉组织培养植株再生存在着两条途径，即胚胎发生途径和器官分化途径；胚状体表面光滑，不定芽表面密生着大量的表皮毛。本文提出了在扫描电镜下鉴别胚状体、不定芽、不定根的形态依据     

大哑铃孢与平滑牛皮叶及其分离藻超微结构的研究

本文应用透射电子显微镜对大哑铃胞（Heterodermia diademata)与平滑牛皮叶（Sticta nylanderiana)两种地衣及其分离藻的超微结构进行了研究。两种地衣的藻的细胞壁均由5层不同电子密度的层次组成，分离藻的细胞壁一般比共生藻的薄，在两种地衣的菌藻相接部位发现细胞壁变薄及缺失现象；大哑铃胞共生藻中发现了蛋白核结构；两种地衣的藻细胞中类囊体发达，类囊体间分散许多嗜锇滴；两种地衣的共生菌中均有同心体存在。     

Influence of plasma and inflammatory proteins on the ultrastructure of exogenous surfactant

We tested the hypothesis that albumin, fibrinogen and eosinophilic cationic protein (ECP) alter not only the function but also the ultrastructural composition of natural bovine surfactant (Alveofact). Therefore, natural bovine surfactant was mixed with equimolar concentrations of these proteins for 2 h and prepared for electron microscopical examination. Volume fractions, the volume to surface ratio and the volume-weighted mean volume were determined by using various stereological methods. Alveofact surface activity was tested with the capillary surfactometer. Native Alveofact-suspension contained mainly multilamellar bodies (numerous concentric predominantly fused compact phospholipid lamellae) and small fractions of multilamellar vesicles (several concentrically arranged lamellae with a less dense order) and unilamellar vesicles (one to two concentrically arranged phospholipid lamellae), but no tubular myelin. Addition of proteins to Alveofact led to a protein-dependent alteration in the distribution patterns of surfactant subtypes. The significant highest decrease in the volume fraction of multilamellar bodies was found in Alveofact-fibrinogen preparations and the lowest decrease was in Alveofact-albumin preparations. Interaction of Alveofact with ECP resulted in a significant decrease in the size of multilamellar bodies and a significant increase in the volume fraction of very small unilamellar and electron-dense vesicles. Alveofact with ECP kept test capillaries open for the shortest time, while Alveofact with albumin had little inhibitory effect. There was a significant correlation between percentage of capillary openness and the volume fraction quotient of inactive to active surfactant subtypes. Thus, equimolar concentrations of different proteins in Alveofact induce a conversion of multilamellar bodies combined with a decrease in surface activity. The most impressive structural alterations were found after mixture with ECP.     

非洲爪蟾卵提取物中环形片层及其核孔复合体的自发形成

用超薄切片电镜技术结合冰冻蚀刻方法观察到在活化的爪蟾卵提取物中环形片层能够自发地大量形成,核孔复合体的超微结构与天然的核孔复合体没有区别,表明核孔复合体的装配能够不依赖于染色质或DNA的诱导而独立进行。进一步研究发现,在上述非细胞体系中,核孔复合体的自发装配需要可溶性组份与膜泡部分的共同参与,说明核孔复合体这种蛋白质性质的细胞器与膜物质有很密切的关系。活化的非洲爪蟾卵提取物为我们深入研究核孔复合体的装配及环形片层与核被膜的关系提供了一个很好的实验模式。     

The cell cycle, including the mitotic cycle and organelle division cycles, as revealed by cytological observations

It is generally believed that the cell cycle consists essentially of the mitotic cycle, which involves mitosis and cytokinesis. These processes are becoming increasingly well understood at the molecular level. However, successful cell reproduction requires duplication and segregation (inheritance) of all of the cellular contents, including not only the cell-nuclear genome but also intracellular organelles. Eukaryotic cells contain at least three types of double membrane-bounded organelles (cell nucleus, mitochondria and plastids), four types of single membrane-bounded organelles (endoplasmic reticulum, Golgi apparatus, lysosomes and microbodies) and the cytoskeleton, which comprises tubulin-based structures (including microtubules, centrosome and spindle) and actin microfilaments. These membrane-bounded organelles cannot be formed de novo and daughter organelles must be inherited from parent organelles during cell cycle. Regulation of organelle division and its coordination with the progression of the cell cycle involves a sequence of events that are subjected to precise spatio-temporal control. Considering that the cells of higher animals and plants contain many organelles which tend to behave somewhat randomly, there is little information concerning the division and inheritance of these double- and single-membrane-bounded organelles during the cell cycle. Here, we summarize the current cytological and morphological knowledge of the cell cycle, including the division cycles of seven membrane-bounded and some non-membrane-bounded organelles. The underlying mechanisms and the biological relevance of these processes are discussed, particularly with respect to cells of the primitive alga Cyanidioschyzon merolae that have a minimum of organelles. We discuss unsolved problems and future perspectives opened by recent studies.