黑线姬鼠肺泡Ⅱ型细胞及表面活性物质的电镜观察

本文对经免疫荧光证明为流行性出血热抗原阳性的黑线姬鼠肺泡Ⅱ型细胞及表面活性物质进行了电镜观察。以抗原阴性的黑线姬鼠,实验室的大、小白鼠的肺组织作为对照。在上述所有的肺组织的肺泡腔面,均可发现髓膜样结构及指纹状结构。后者由髓管组成,其横断面呈晶格状,类似病毒颗粒,与Lee在1978年报道的流行性出血热的病毒样颗粒,几乎一致。本研究描述了由髓膜样结构发展为指纹状结构及肺泡Ⅱ型细胞中,多板层小体发展为髓膜样结构的过程。在肺泡Ⅱ型细胞中尚观察到由线粒体发展为多板层小体的多种过渡形态。     

家蝇复眼小网膜的超微结构

用电子显微镜研究了家蝇(musca domestica)复眼小网膜的一般结构,特殊结构和小网膜细胞的对称性排列,并比较了在暗适应、明适应和强光适应状态下小网膜细胞的结构。家蝇复眼的每个小网膜一般由八个小网膜细胞组成,某些小网膜是由六、七、九和十个小网膜细胞组成。家蝇的左复眼与右复限、复限的背区与腹区中,小网膜细胞呈镜像对称排列。另外,在复眼的背区或腹区中,有的小网膜细胞之间也呈镜像对称排列。家蝇复眼在强光适应状态下,No.1～6小网膜细胞内大部分色素颗粒移动到感杆(rhabdomere)附近,而No.7～8小网膜细胞内色素颗粒一般不移动,但有些No.7～8小网膜细胞内色素颗粒也有移动。     

人表皮的冷冻复型电镜观察

本文应用冷冻复型法,对5例人小腿部脾经与胃经低电阻线下的表皮,进行了电镜观察。发现棘细胞具有粗大突起和微绒毛。颗粒细胞呈梭形,细胞表面呈波浪状;其胞膜的劈裂面上膜内微粒较棘细胞者少;但膜被颗粒的外排小孔则较之为多,其大小为50～75nm,平均数为47.5/μm~2;胞质内除个别线粒体外,主要为呈各种走向的张力细丝束;其间散布着膜被颗粒,接近角化细胞者多位于胞膜下方,直径为60～88nm。颗粒细胞核膜的膜内微粒及按孔均很稀少。角化细胞呈扁平状,胞膜明显增厚,其劈裂面上除桥粒区外,无膜内微粒和外排小孔;深层细胞的胞质可见大量细丝,而浅层者胞质呈均质状。桥粒在深层细胞多,至角化层渐减少,且呈退化状态。在颗粒层细胞间隙内,可见由膜被颗粒外排物质先附于细胞外表面,继而出现板层状膜及原纤维状结构,后者直径为70～100nm,具有间距为60～70nm的横纹。     

大鼠肺表面活性物质系统起源结构与板层体超微结构的研究

本文报道用扫描电镜、冷冻蚀刻和超薄切片透射电镜观察大鼠一次注入粉尘及不同间隔期肺洗出液中Ⅱ型肺泡上皮细胞的板层体、管状髓鞘结构、晶格髓鞘结构的结果。根据膜劈裂学说,结合冷冻蚀刻图象显示的管状髓鞘结构断裂情况,认为板层体是由正方形结品构成。一些正方形结晶作为亚单位,互连组成有框架的方形柱状体。几十层柱状体规则排列,纵横延伸,经纬交错,构成树木年轮样板层。板层一层一层包绕,形成球体——板层体。板层体形态有三:毛绒团状板层体、同心圆状板层体和网格板层体。我们看到同心圆状板层体游离子细胞外或细胞崩解后,板层自外向内地展平而形成表面活性物质系统。对照组大鼠肺洗出液中表面活性物质系统含量,从形态学来看,远远低于染尘组(包括气管注入石英、活性碳、铀矿粉及U_3O_8等粉尘)。     

四肢骨骨化性纤维瘤7例病理分析与鉴别诊断

本文报道四肢骨骨化性纤维瘤7例,男性4例,女性3例,年龄10～46岁,平均20岁。主要临床表现为局部肿块。镜下所见:肿瘤由肿瘤性纤维结缔组织和骨小梁组成,典型的骨小梁周边部呈平行的板层结构,中央呈不太清晰的编织状结构,骨小梁外周有密集的单行排列的骨母细胞和少数破骨细胞,所有病例均无出血、炎症和死骨片。本瘤应注意与非骨化性纤维瘤、骨纤维异常增殖症、骨囊肿和骨巨细胞瘤鉴别。     

具石棉样胶原纤维的脑膜瘤

目的 探讨脑膜瘤石棉样纤维的本质及其形成机制。方法 应用HE染色、组织化学、免疫组织化学染色及电镜观察l例具石棉样纤维的脑膜瘤的特点。结果 光镜下石棉样纤维为粗细均一的、呈放射状整齐排列的嗜酸性细丝构成的小体。ABPAS和网染小体周围带呈强阳性，中央中间带呈阴性。FN免疫组化染色小体边缘带阳性，中央中间带阴性。电镜下石棉样纤维由平行排列的胶原原纤维组成，与周围肿瘤组织内的胶原纤维有近似的周期和宽度，但原纤维平行排列呈放射状或栅状。结论 本例脑膜瘤，石棉样纤维是一种呈放射状排列的粗大胶原纤维，纤维沉积在球形或半球形的空隙内，小体周围瘤细胞与间质通过小体表面对小体具有均等的吸附力，使其呈放射状排列。     

人腰椎间盘纤维环超微结构的研究

应用扫描和透射电镜观察到人腰椎间盘纤维环(LAF)是由三种方向平行排列的真胶原束构成的板层结构。板层厚薄不匀,板内胶原束的排列松紧不一。胶原鞘不典型,横纹结构清楚。在胶原束之间有软骨细胞和成纤维细胞。它们的共同特征是都具有清楚的核膜,染色质呈细粒状,细胞质内有大量囊泡和颗粒状物质,但是又表现为细胞突起、光滑度、胞周间隙大小和集聚性等方面的差异。蛋白多糖基质依据其所在部位以及它与周围组织的关系,可以区分出粘糊状、颗粒状和团块状形式,主要分布于胶原束和胶原微纤维之间以及细胞的表面。     

版纳鱼螈肝、胆囊及胰的解剖学和组织学

目的:研究版纳鱼螈肝、胆囊和胰的形态结构.方法:肉眼结合使用体视显微镜观察和测量大体结构;组织学材料用Bouins液固定,石蜡包埋,连续切片, H-E染色,数码显微镜下观察、拍照和测量.结果:版纳鱼螈的肝呈长带状,背侧不分裂,腹侧分割成大小和数量不等的小肝叶;肝小叶分界极不明显,肝细胞呈腺泡或团块状排列,门管区未见小叶间动脉.胆囊椭圆形,胆囊壁由黏膜、肌层和浆膜构成.胰分左右两叶,外分泌部由腺泡和各级排泄管组成,内分泌细胞零散分布于外分泌部之间,数量少,未聚集成胰岛.结论:丰富了版纳鱼螈消化系统的解剖学和组织学资料,为分析探讨其分类和进化地位提供了基础信息.     

兔胰腺外分泌部的扫描电镜观察——DMSO冷冻割断法

本文以二甲亚砜(dimethyl sulfoxide,DMSO)冷冻割断技术处理正常兔胰腺,在扫描电镜下研究胰腺外分泌部超微结构。兔胰腺外分泌部由许多腺泡组成,每一腺泡由5～6个锥形细胞围绕形成,中央为腺泡腔。腺细胞顶端有短小微绒毛。细胞核呈球形,位于细胞基底部,核内含有1～3个核仁。细胞基底部有大量粗面内质网,呈纵行或同心圆形排列,线粒体介于其间。粗面内质网常自细胞基底部伸向细胞核上端,表面附着核蛋白体。细胞核上端有丰富的高尔基复合体,周周可见散在的球状酶原颗粒。     

软组织骨化性纤维黏液样肿瘤2例报道及文献复习

目的 探讨软组织骨化性纤维黏液样肿瘤(ossifying fibromyxoid tumor of soft tissue,OFT)的临床病理、免疫表型特征及其诊断和鉴别诊断.方法 对2例OFT临床病理资料进行分析、光镜观察及免疫组化标记,并复习相关文献.结果 2例患者临床表现均为皮下缓慢生长的肿块.手术完整切除肿块,大体标本表面均有一层不完整的骨壳.术后病理组织学检查见肿瘤边界清楚,有纤维性假包膜,包膜内有一层薄的不连续的由成熟化生的板层骨构成的骨小梁,肿瘤略呈分叶状,内见有圆形、卵圆形、短梭形瘤细胞呈巢状、索状、网格状、镶嵌状排列,核染色质细致,未见明显核分裂象,有明显纤维黏液样背景的间质.免疫表型:vimentin、S-100蛋白均(+),CK(-).结论 OFT是一种分类尚未确定的罕见肿瘤,属中间型肿瘤.其特征性的骨壳结构、独特的细胞形态及排列方式、免疫表型具有诊断意义.     

Adrenergic nerve elements in the hypogatric ganglion of the guinea pig

Adrenergic nerve elements in the hypogastric ganglion of the guinea pig were studied by fluorescence and electron microscopy. The ganglion contains two main elements exhibiting green to green-yellow fluorescence for catecholamines. One consists of basket-like, simple nerve endings around some of the ganglion cell bodies, and the other of small polyhedral cells with short axonic processes. Electron microscopy revealed the ultrastructure of these elements. The adrenergic nerve endings contain small granular vesicles, about 500 Å in diameter, as well as a few large granular and small agranular vesicles. They were more rare than the cholinergic endings, which contain numerous small agranular vesicles mixed with a few large granular vesicles. Both adrenergic and cholinergic endings submerge to a considerable depth into the cytoplasm of ganglion cells. The ganglion cells send spinous processes into these endings. The fluorescent polyhedral cells are probably in an intermediate position between adrenal medullary cells and ganglion cells. They contain numerous large granular vesicles. Their axonic processes extend for a short distance to end in close topographical relation to capillaries. According to the structure of the granulated vesicles, these cells were classified into four types. The function of the adrenergic elements in ganglionic transmission was discussed.     

Primary neuroendocrine carcinoma with ganglion cell differentiation in a crural lymph node

A primary neuroendocrine carcinoma with ganglion cell differentiation is described in a crural lymph node. The patient, a 48-year-old woman, presented a palpable lymph node of the crural region in March 1994. Histologically, the lesion was composed mostly of small cells immunoreactive for cytokeratins, neuron specific enolase and synaptophysin. The small cells merged gradually with areas containing ganglion cells immersed in a fibrillar matrix resembling neuropil. Ganglion cells expressed neuron-specific enolase, synaptophysin, neurofilament proteins and S-100 protein. Moreover, a minority of them featured cytokeratin expression. Electron microscopy was performed in the small cell component. These cells featured attenuated desmosomes and electron dense granules with an average size of 120 nm within bundles of intermediate filaments. Clinically, no tumour was found elsewhere despite extensive work-up over the 76-month follow-up period. Although similarities with previous cases of primary neuroendocrine carcinoma of lymph node, ganglion cell differentiation has never been described.     

小白鼠甲状腺神经节的形态学观察

应用镀银、硫堇及HE染色法和石蜡连续切片,可见不同鼠龄小白鼠甲状腺内侧缘上端与喉肌之间存在有类似典型的植物性神经节结构。此外,节的附近偶有散在的单个神经节细胞。神经节的位置、数量及大小个体不一,节的外面通常具有结缔组织的被膜,膜的胶原纤难向节内延伸成网、基质内有神经节细胞、神经胶质细胞和毛细血管。此外,尚有穿过节的有髓神经纤维等。神经节细胞散在分布,但以节的边缘为多,为多极神经元,胞体卵圆或不规则,尼氏小体呈细颗粒状,边缘较多,神经原纤维纤细世网。细胞核偏位,大而圆,染色质稀少呈空泡状,核仁明显,1—2个,此外核内尚有数个染色质聚集的不规则小块。幼龄小鼠可见双核神经节细胞。胞体外围有卫星细胞(被囊细胞)形成的被囊。神经节附近有甲状腺动脉、静脉主干同时出现,并显示为神经通路上(或稍偏离)之膨大结构,由其分出节前纤维进入节内,与神经节细胞形成突触。神经节内有错综交织的节前、后纤维及树突形成的神经网。研究表明小白鼠甲状腺附近存在有副交感神经节,其节后纤维分布有待进一步研究。     

Double myelination of axons in the sympathetic nervous system

Summary Relationships between axons and Schwann cells in myelinated fibres of the superior cervical (sympathetic) ganglion have been examined in normal adult rats. In cross-sections through the ganglion up to 4 % of myelinated fibres were focally encircled by an additional myelinating Schwann cell, forming regions termed double myelination. In these regions and elsewhere in the ganglion, the structure of the inner fibre (axon and myelinating Schwann cell) conformed to the relationships expected on the basis of numerous previous investigations on normal peripheral nerve. However, the outer Schwann cell and myelin sheath, which formed an annulus around the inner fibre, was remarkable in that it apparently made no direct contact either with the centrally enclosed axon or with any neighbouring axon, yet appeared largely if not completely intact. In addition, the increasing frequency of double myelination in older animals and the rarity of myelin degeneration in the same ganglia indicate that the outer Schwann cell, and in particular its myelin sheath, persist for some period in an isolated form. Double myelination was not located in non-sympathetic peripheral nerve samples from the same animals. Double myelination may result from the displacement of one myelin internode by the interposition of another Schwann cell rendering the original Schwann cell redundant. There was no involvement of haematogenous cells as occurs in some demyelinating conditions. While some parallels may be found with previous studies, this would appear to be the first report of apparent survival of myelin in a Schwann cell not making, as far as could be determined in the present study, at least partial direct axonal contact. These observations on sympathetic nerve may provide a new perspective on axon-Schwann cell signalling.     

Embryonic development of the myenteric nerve plexus in the rat small intestine as revealed by light and scanning electron microscopy

This study was performed to clarify developmental changes in the structure of the myenteric nerve plexus in the rat small intestine. The small intestines of fetal and neonatal rats were examined by light microscopic immunohistochemistry for protein gene product 9.5 (PGP-9.5) and alpha-smooth muscle actin (alpha-SMA). Direct observation of the three-dimensional structure of the neuronal and muscular elements was accomplished by scanning electron microscopy of tissues after KOH treatment. At the embryonic day 14 (E14), PGP-9.5 immunopositive (neuronal) cells first appeared in the mesenchymal tissue outside an alpha-SMA positive (muscle) cell layer. These cells increased in number to form a thin and continuous sheet, which was sandwiched between the inner and outer muscular layers at E17. This neuronal layer consisted of immature ganglion cells associated with supportive (enteroglial) cells, and was gradually segregated into groups by incomplete separation through slit-like interruptions at E18. With the widening of these slits at E19, the neuronal sheet was observed as a ladder composed of transversely elongated ganglia and their connecting nerve strands, resulting in the typical structure of the myenteric nerve plexus. Fibroblastic cells of a peculiar shape appeared on the outer surface of the myenteric plexus at E19. These cells (presumably interstitial cells) interconnected their long branching projections to form a cellular network on the myenteric plexus until birth.     

AN ULTRASTRUCTURAL STUDY OF HUMAN JUXTAGLOMERULAR CELLS

An electron microscopic investigation was made on the Juxtaglomerular cells (JC) of human renal glomeruli. This study corroborates the myoepithelioid appearance of JC situated in the wall of the afferent arteriole. These cells contain secretion granules as well as fibrillar bundles similar to myofilaments of the smooth muscle cells, while JC located farthest from the afferent arteriole lack them. In addition, a transitional form from agranular to granular JC is noted. It is presumed that (1) JC have a potency of a two-way differentiation (muscular and endocrine), and (2) granular JC are derived from agranular JC.
The existence of several types of intercellular Junctions and the occurrence of cilia in human JC have also been demonstrated in the present study.     

Synaptic membrane structure in Torpedo electric organ.

The innervated and noninnervated membranes of Torpedo electrocytes have been examined by electron microscopy of thin-sectioned and freeze-fractured specimens. The ventral innervated membrane is approximately 120 A thick and is characterized by an unusually broad outer dense lamina (approximately 60 A) in which a granular substructure can be resolved. The granules are approximately 70 A in diameter and are spaced irregularly. The same membrane specialization was noted in a previous study of amphibian myoneural junctions, and it was proposed then that the granular elements represent ACh receptor molecules. The morphologically equivalent structures presumably have the same significance in the Torpedo electric organ. However, in this case the specialized membrane covers the entire innervated surface, leading to the conclusion that high concentrations of receptors occur normally in extrajunctional as well as post-junctional regions of the innervated membrane of the electrocyte. In replicas of freeze-fractured specimens, the A face of this membrane is covered with large particles having the same distribution and approximate concentration as the granules visible in thin sections, indicating that the granules visible at the outer surface of the membrane extend at least into the hydrophobic middle layer of the membrane. The cytoplasmic surface of this membrane has an amorphous coating into which 'decorated' cytoplasmic filaments insert. Synaptic vesicle and axon terminal membranes also contain granules visible in thin sections but with a much sparser distribution. These probably correspond to the intramembranous particles seen in freeze-fractured specimens. Vesicles are occasionally attached to the axolemma by thin linear strands.     

The lack of a structured blood-brain barrier in the onychophoran Peripatus acacioi

Summary Onychophorans are ‘living fossils’ frequently purported to have evolved from the same ancestor as the arthropods and annelids. In the CNS ofPeripatus acacioi, beneath an outer acellular neural lamella, glial cells ensheath the cerebral ganglion and the nerve cords. These glial cells are, however, attenuated and rather few in number and, although they interdigitate with one another, they seem to lack intercellular junctions. Exogenous tracers penetrate between them and into the underlying neuropile, suggesting that there is no structural blood-brain barrier. Throughout the nervous tissue, extracellular spaces occur which contain banded collagen fibrils embedded in a matrix material. Thin glial cell processes, characterized by dense filaments, surround these regions and frequently form hemi-desmosomes with the extracellular matrix. The peripheral nerve cell bodies have a range of diameters; some have the characteristics of neurosecretory neurons. Granules in such neurons are produced by the Golgi saccules and associated fenestrated membranes which also possess many coated vesicles. Comparable granules are also found in axonal tracts, but no distinct peripheral neurohaemal areas have been found. Lysosomes are common in the nerve cell bodies and are frequently in the form of multivesicular bodies or large phagocytic vacuoles. Beneath the outer nerve cells lie many tracheae, arranged as a ring around the central neuropile which consists of glial processes, extracellular matrix, axons and nerve terminals. These nerve terminals occur throughout the central neuropile and are characterized by dense pyramidal presynaptic specializations and postsynaptic subsurface cisternae. The nervous system ofPeripatus is relatively simple in its organization, in the lack of glial intercellular junctions and in the ready accessibility of substances from the external milieu.     

东方对虾有髓神经纤维的个体发生的电镜观察

用电镜技术观察了东方对虾（Ｐｅｎａｅｕｓｏｒｉｅｎｔａｌｉｓ）有髓神经纤维的髓鞘化，以及位于其髓鞘与轴突间被命名为髓鞘下间隙和微管鞘这两个侍有结构的个体发生过程。结果如下：（１）在无节幼体（ｎａｕｐｌｉｕｓ）已有由神经历细胞和神经胶质母细胞构成的神经成分出现；（２）在状幼体（ｚｏａｅａ）神经细胞发生裸露的突起，其直径不等，走向不一；（３）在糠虾幼体阶段（ｍｙｓｉｓｓｔａｇｅ）已形成了与成体虾相似的腹神经索，其中的一对内侧巨大纤维已出现，并开始髓鞘化。在此发育阶段后期这两根巨大纤维的髓鞘开始脱离轴突，形成间隙，并在轴突周围开始出现由微管束构成的鞘。在此发育阶段虽已可辨认出一对外侧巨大纤维，但通常尚未髓鞘化；（４）在仔虾（ｐｏｓｔ－ｌａｒｖａ）阶段神经索中许多较粗神经纤维开始髓鞘化，也是由新生的髓鞘直接包绕轴突，然后与之脱离形成髓鞘下间隙和形成直接复盖轴突的微管鞘；（５）髓鞘的形成不是如在脊椎动物髓鞘通常所见到的那样，由一许旺细胞的浆膜片以螺旋方式包绕轴突而形成的，对虾髓鞘的形成则是由许旺氏细胞向两侧伸出许多浆膜片以同心方式包绕轴突，当两侧的浆膜片在某处相遇时，均形成内含２至数根微管的终扣（ｔｅｒｍｉｎａｌｌｏ?     

Influence of age on nuclear bodies and nuclear volume in pituicytes of the rat neurohypophysis

This study has analyzed age-related changes in the nuclear organization of pituicytes of the rat. The cytological study of the cell nucleus and the quantitative analysis of nuclear bodies (NBs) were performed on ultrathin sections. Nuclear diameter, perimeter, and area were measured on semithin sections, and nuclear volume was estimated from these data. The nucleolus was mainly composed of a few large fibrillar centers with their associated dense fibrillar component, whereas the granular component tended to form large masses at the nucleolar periphery. The most frequent configuration of NBs was a globular inclusion composed of a fibrillar capsule with a core that contained a few electron-dense granules. Intranuclear glycogen was detected on rare occasions and only in old rats. The proportion of nuclear sections containing NBs increased significantly from 1.5% in 3-month-old rats to 8.6% in 18-month-old rats. A significant increase in the nuclear volume was detected in older rats with respect to the younger ones (157 +/- 69 vs. 98 +/- 43 microns 3, mean +/- S.D.). Our results suggest an age-related activation of nuclear metabolism in pituicytes resulting in a nuclear expansion and an increase in the frequency of appearance of NBs. This activation might be a reactive cellular event induced by the degenerative changes in neurosecretory nerve endings naturally occurring in older animals.