Surface topography and ultrastructural changes of mucinous carcinoma breast cells

Mucinous carcinoma of the breast (MCB) is histologically classified into 2 groups: (1) pure MCB and (2) mixed MCB. Pure MCB carries a better diagnosis than mixed MCB. This research relates to the cell surface topography and ultrastructure of the cells in the above cases and aims to find the differences between them, by means of two methods: scanning electron microscopy (SEM) and transmission electron microscopy (TEM). For the SEM examination, it was necessary to initially culture the MCB tissues and then proceed with the usual SEM method. In contrast, for the TEM technique, MCB tissues were initially fixed followed by the classic TEM method. The authors found the topography of pure MCB cases to be without nodes. The cell membrane was smooth, with numerous pores and small ruffles that covered the entire cell. The ultrastructural appearance of the same cases was with a normal cell membrane containing abundant collagen fibers. They also had many small vesicles containing mucin as well as secretory droplets. In contrast the mixed MCB had a number of lymph nodes and their cell surface topography showed stronger changes such as microvilli, numerous blebs, ruffles and many long projections. Their ultrastructure showed very long microvilli with large cytoplasmic inclusions and extracellular mucin collections, electron-dense material vacuoles, and many important cytoplasmic organelles. An important fact is that mixed MCB also contains areas of infiltrating ductal carcinoma. These cells of the cytoplasmic organelles are clearly responsible for the synthesis, storage, and secretion of the characteristic mucin of this tumor type. Evidently, this abnormal mucin production and the abundance of secretory granules along with the long projections observed in the topographical structure might be responsible for transferring tumor cells to neighboring organs, thus being responsible for metastatic disease.     

大鼠脑脊髓不同部位室管膜上皮细胞表面的超微结构特征--扫描电镜观察

目的 研究大鼠脑脊髓室管膜上皮细胞的区域性结构特征，并初步探讨其功能。方法 采用扫描电子显微镜观察法。结果 侧脑室壁室管膜上皮细胞游离端呈不规则多边形，可见纤毛及微绒毛，偶见分泌泡。侧脑室脉络丛上皮细胞游离端呈不规则多角形、梭形或三角形，微绒毛、分泌泡丰富，纤毛少见，可见“丛上细胞”。第Ⅲ脑室室管膜上皮细胞具明显区域性，脑室底部上皮细胞微绒毛短小、散在，有少量分泌粒，无纤毛；侧壁分泌泡较多，纤毛丰富；均可见“丛上细胞”。第Ⅲ脑室脉络丛上皮细胞可见大量细长微绒毛，分泌泡及“丛上细胞”较少。室问孔室管膜上皮呈梭形，长轴与室间孔平行，游离面罕见微绒毛，“丛上细胞”较多。穹窿下器及终板处室管膜细胞纤毛少见，而正中隆起处可见大量纤毛及微绒毛，并可见单个散在的纤毛上皮细胞。中脑导水管壁具有平行走向的纵嵴，游离面可见大量纤毛、微绒毛及分泌泡。第Ⅳ脑室室管膜上皮具大量长纤毛及微绒毛，分泌泡罕见。第Ⅳ脑室脉络丛上皮游离面呈多型性，可见短小密集的微绒毛及处于不同分泌周期的分泌泡，以及形态各异的“丛上细胞”，偶见纤毛上皮细胞及特殊的单鞭毛上皮细胞。脊髓中央管结构较简单，游离面可见大量长纤毛、微绒毛及分泌泡。结论 大鼠脑脊髓室管膜不同部位上皮细胞游离面超微结构差异，可能与其功能不同有关。分泌泡、纤毛及微绒毛的大小及多寡，可能是脑脊液的分泌、流动及代谢活性中分别有区域性不同的形态学基础。     

Large cell lymphoma with microvillus-like projections: an ultrastructural study

On many of the cells of each of the 10 large cell lymphomas we studied, electron microscopy demonstrating slender peripheral cytoplasmic projections that simulated microvilli. They varied in number, but, when numerous, easily could be misinterpreted as evidence of adenocarcinoma. Immunoperoxidase staining confirmed the presence of monoclonal cytoplasmic immunoglobulin in four of 10 cases. Stains for muramidase were negative in every case. Because nine of the 10 cases were of presumed B-cell lineage, the lymphoma cells are compared to transformed lymphocytes from the follicular centers of reactive lymph nodes.     

The allantoic and amniotic epithelia of the pig: SEM and TEM studies

Summary The epithelial layers of the allantoamnion of pig embryos and fetuses during various gestational ages were studied utilizing SEM, TEM, and light microscopic histochemistry. The allantoic endoderm exhibits a gland-like secretory activity and thereby differs greatly from that of other mammals. On the surface of this unilaminar cuboidal epithelium, the majority of the cells exhibit characteristic short vermiform ridges, while some protruding cells display larger individual microvilli. These two cell types are also distinct in thin sections. The more common granular cells with short and blunt microvillous projections and a lobated nucleus are characterized by small, Golgi-derived secretory granules in the apical cytoplasm showing a positive PAS-reaction. They contain vast glycogen deposits. Extensive regions of lateral interdigitations are found. In the younger stages, membrane thickenings of the apical plasmalemma resemble those of the urinary bladder. The cytoplasm harbors many more interwoven filaments than organelles. The second cell type, the mitochondria-rich cells, bearing longer apical microvilli in many cases, only constitutes up to 3% of the mucosal cell population. They are frequently flask-shaped, heavily reactive to oxidoreductases, and rich in lysosomes but have smaller glycogen deposits. Mitochondria-rich cells lack secretory granules but have light apical tubules, probably of endocytotic character. These cells can be found in different functional states. The amniotic epithelium is simple squamous in the younger stages and largely resembles that in other mammals exhibiting cells with few organelles but rich in filaments. Each terminal bar consists of a zonula occludens only which may open toward the end of gestation. In older fetuses, small stratified areas of cells sloughing off into the lumen appear as blisters which contain large vacuolated cells.     

A morphometric study on the ultrastructure of well-differentiated tumours and inflammatory mucosa of the human urinary bladder

Summary Transmission (TEM) and scanning electron microscopic (SEM) observations were performed on well-differentiated tumours and chronic cystitis in the human urinary bladder. SEM showed that the pleomorphic microvilli were present not only on the luminal surface of the tumour but also on the surface of inflammatory mucosa. The ultrastructure of six tumours and 5 cases of chronic cystitis was evaluated morphometrically. Bladder tumour and inflammatory mucosa were divided into several layers, namely outermost cells (S), subsurface cells just beneath these (S1), subsurface cells of 2 or 3 layers below (S23), intermediate cells of 2 or 3 layers above the basal cells (123), intermediate cells just above the basal cells (I1) and basal cells (Ba). Areas of nucleus, cytoplasm and cytoplasmic organelles, numbers of nucleoli, nuclear bodies, mitochondria and lysosomes together with irregularity of the cell and nucleus were estimated according to the methods of Weibel. A multi-variate analysis of variance on these variables showed that the above subdivision of layers was necessary for the comparison of tumour and inflammation. Discriminant analysis showed various differences between tumour and inflammatory mucosa. The results indicated that the Ba layer is the most effective site for differentiating the tumour from inflammation. Ba cells with large and irregular cytoplasm with an enlarged Golgi area, accompanied by many vacuolar structures, may be indicative of tumour rather than inflammation.     

Fine structure of bat deep posterior lingual glands (von Ebner's)

We studied the morphology and ultrastructure of the bat (Pipistrellus k.k. and Rhinolophus f.e.) deep posterior lingual glands (Ebner's glands) during hibernation, summer and after stimulation with pilocarpine. Ebner's glands are formed by serous tubulo-alveolar adenomeres and by an excretory system organized in intercalated ducts, long excretory ducts and a main excretory duct. The latter opens in the vallum which surrounds the circumvallate papillae and in the groove of the foliate papillae. The secretory cells, which lack basal folds, show abundant and dense granules (PAS+, Alcian blue -), microvilli (scarce during hibernation), a Golgi apparatus (well developed during summer and after stimulation with pilocarpine), a large nucleus and RER cisternae stacked at the basal pole. Centrioles, lipid droplets, heterogeneous bodies (in content and density, probably lipofuscin bodies), lysosomal multivesicular bodies and large, dense granules with a microcrystalline structure were also encountered. The lateral membranes of adjacent cells are joined by desmosomes; their interdigitations are neither numerous nor prominent during summer. Microfilaments, often gathered in small bundles, lie in the lateral, peripheral cytoplasm without any relation with desmosomes. In summer and particularly after stimulation with pilocarpine, the apical pole of the secretory cells is characterized by many long microvilli, pedunculated hyaloplasmic protrusions and secretory granules. During hibernation the lumen is filled with secretory material. Myoepithelial cells are arranged among secretory cells or between them and the basal lamina. The short intercalated ducts show similarities with the analogous ducts of the parotid gland. Striated ducts are absent. Excretory ducts are endowed with: a) an inner layer of cuboidal cells characterized by poorly developed cytoplasmic organelles, rare dense granules and a few small microvilli; b) an outer layer of basal cells lying on the basal lamina. Myoepithelial cells are absent. The main excretory duct is lined by a stratified epithelium with an inner layer of conical-pyramidal cells surrounded by two-three rows of basal cells. The conical-pyramidal cells show poorly developed organelles, an apical border with small short microvilli and a prominent terminal web.     

Identification of challenged subarachnoid free cells

Three distinct types of free cell contours are recognizable in scanning electron microscopy (SEM) on the leptomeningeal sheaths of dogs twelve days after an intrathecal injection of bacillus Calmette-Guerin (BCG). Macrophages possess abundant plasmalemmal blebs which are shown in transmission electron microscopy (TEM) to be composed of large membrane-bound vacuoles. Smooth surfaced lymphoblasts exhibit many basal microvilli that rest upon and often indent the plasmalemma of an underlying pial cell. Neutrophils display many microvilli over their rounded, chrysanthemum-like surfaces. The consistency with which these external features are expressed suggests that each cell type possesses characteristic surface topography, at least under these conditions of challenge.     

Ultrastructure study of the intramolluscan stages of Meiogymnophallus minutus (Digenea: Gymnophallidae) in Scrobicularia plana (Bivalvia) from Portugal

 The ultrastructure of the tegument of the sporocyst and contained cercariae of Meiogymnophallus minutus found in Scrobicularia plana collected in Ria de Aveiro estuary (Portugal) were studied by scanning (SEM) and transmission electron microscopy (TEM). TEM revealed microvilli extending from the surface of the sporocyst tegument that contributed to the lace-trimmed surface morphology observed by SEM. The cercarial surface was papilliform and covered densely with single-pointed tegumental spines. On TEM, besides the spines and several mitochondria, translucid and electron-dense spherical secretory vesicles were evident in the matrix of the tegument but were not seen on the sporocyst tegument. Uniciliate sensory receptors found in the cercaria of M. minutus were examined under SEM and TEM. Structural differences between the oral and the ventral sucker were observed. On the lip of the ventral sucker, large and strong spines were arranged in concentric rows, and two groups of six sensory papillae were placed concentrically and equidistantly. The oral sucker, surrounded by a crown of dense and long microvilli, exhibited a ring of uniciliate sensory papillae and some tegumental spines along the lip. The surface morphology of the M. minutus cercaria is compared with that of other Gymnophallidae cercariae. Received: 7 September 1995 / Accepted: 16 December 1995     

Ultrastructure of Well-Differentiated Adenocarcinoma of the Gallbladder

The ultrastructure of four well-differentiated adenocarcinomas of the gallbladder was investigated by scanning and transmission electron microscopy and compared with the ultrastructure of nonneoplastic mucosa in the same specimens and of the mucosa of gallbladders with gallstones. The tumor cells seen by scanning electron microscopy had severe disorganization of the regular arrangement of columnar cells. They were bizarre in shape and size and were covered with less developed pleomorphic microvilli that were irregularly distributed. No such findings appeared in the control specimens. The tumor cells seen by transmission electron microscopy exhibited pleomorphic microvilli, well-developed cytoplasmic organelles, various mucus granules, abundant lysosomes, and nuclear changes. These findings suggest increased secretory and metabolic activity in the tumor cells. Gobletlike cells, Paneth-like cells, and endocrine cells were scattered in two of the carcinomas. These cells were also noted in the nonneoplastic mucosa of the carcinoma specimens but were rare in the mucosa when cholelithiasis was present.     

Extra-long Projections of the Cell Surface in Nonspecial-type Ductal Carcinoma with Vascular Invasion under the Scanning Electron Microscope

In this study, cell surface projections of primary culture cells from tissues of infiltrating ductal carcinoma Non Special Type with vascular invasion are examined by use of the Scanning Electron Microscopy method. In these cases the projections of cell membrane appeared extremely long and bridge-like covering very long distances between the breast cancer cells. Also, the long cell membrane projections, connect cells between them and form a complex. Sometimes, from one edge to another we observed a very long chain of cancer cells reaching sometimes a length of 3, 3?mm. On the other hand the absence of vascular invasion never shows such long projections of the cell membrane even if there are many metastatic nodes. The role of these extra long projections in communication between cancer cells is determinant. Through this communication, these long projections seemed to be responsible for the metastatic process in primary breast cancer with vascular invasion.     

The proximal border of the human respiratory unit, as shown by scanning and transmission electron microscopy and light microscopical cytochemistry.

The epithelial cell types present in respiratory (= distal alveolarized) and terminal (= distal nonalveolarized) bronchioles in adult human lung were characterized with scanning and transmission electron microscopy (SEM, TEM) and light microscopic cytochemistry, using specific antibodies against surfactant protein SP-A and mucins, and Alcian blue/periodic acid-Schiff (AB/PAS) staining. In the respiratory bronchiole, two epithelial cell populations share the same basal lamina: one pseudostratified columnar with ciliated, secretory, and basal cells and the other predominantly simple cuboid with some interspersed flat (type I) cells. The columnar secretory cells show the ultrastructure of mucous cells. Light microscopically, they react with mucin antibodies and contain primarily periodate-reactive acid mucins. The mucous cells are the distal secretory cells described by Clara (1937). The cuboid cells are identified as type II (precursor) cells based on ultrastructural criteria for embryonic type II cells (Ten Have-Opbroek et al., 1988a, 1990a), including a cuboid cell shape, a large and roundish nucleus, rough and smooth endoplasmic reticulum (ER), osmiophilic multivesicular bodies, and dense bodies. These dense bodies in turn frequently exhibit--like those in embryonic type II cells--internal vesicles or lamellae, variability in size and shape, a specific relationship to ER and a widespread cytoplasmic distribution. Finally, the cuboid cells show a cytoplasmic staining pattern for SP-A. The terminal bronchiole is lined by the columnar cell population. In the respiratory bronchiole, the columnar (bronchial) and cuboid (alveolar) cell populations occupy distinctly different zones (pulmonary artery zone versus remaining wall). The alveolar part of the respiratory bronchiole (called alveolar tubule) defines the proximal border of a true respiratory unit.     

出生后10—90天大鼠附睾管上皮主细胞超微结构的观察

本文应用透射电镜观察了生后第10至90天大鼠附睾管上皮主细胞的超微结构。结果表明:第10天上皮细胞处于未分化状态,胞浆内充满了大量游离核糖体,其它细胞器均少见;第19天上皮细胞已开始分化,游离缘出现少量短粗微绒毛和微吞饮内褶,Golgi复合体渐发达且数量增加;第50天上皮细胞已具成年大鼠主细胞的超微结构,微绒毛发达,微吞饮内褶和多泡体丰富,Golgi复合体发达。本文对生后大鼠附睾管主细胞出现上述超微结构变化的意义进行了讨论。     

An ultrastructural study of the effects of asbestos fibres on cultured peritoneal macrophages

The effects of crocidolite and chrysotile fibres on lavaged peritoneal macrophages have been studied by both scanning (SEM) and transmission (TEM) electron microscopy. SEM provided little information (as the surface topography did not reflect the underlying cytoplasmic organization) except that it showed that individual macrophages often partially engulfed many long fibres in a random fashion. TEM revealed the fibres in and protruding from membrane-bound vacuoles, free in the cytoplasm and penetrating the nucleus. The cellular distribution of the fibres is discussed in terms of the cytotoxic nature of the fibres and their ability to produce a selective release of enzymes from the macrophages.     

An ultrastructural study of the effects of asbestos fibres on cultured peritoneal macrophages.

The effects of crocidolite and chrysotile fibres on lavaged peritoneal macrophages have been studied by both scanning (SEM) and transmission (TEM) electron microscopy. SEM provided little information (as the surface topography did not reflect the underlying cytoplasmic organization) except that it showed that individual macrophages often partially engulfed many long fibres in a random fashion. TEM revealed the fibres in and protruding from membrane-bound vacuoles, free in the cytoplasm and penetrating the nucleus. The cellular distribution of the fibres is discussed in terms of the cytotoxic nature of the fibres and their ability to produce a selective release of enzymes from the macrophages.     

Surface topography and interactions between mouse peritoneal cells allowed to settle on an artificial substrate: observations by scanning electron microscopy.

Identical mouse peritoneal lymphocytes, macrophages, mast cells, and polymorphonuclear leukocytes incubated on VS Millipore filters have been identified by light microscopy and then studied by scanning electron microscopy. The surface of the lymphocyte is covered with varying numbers of microvilli, and it has very little interaction with the substrate. The spherical macrophage has a surface composed of several levels of tight ridges and folds which become more separated and even disappear as the cell spreads out. The mast cell has both long and short microvilli and folds spread unevenly over an undulating surface through which the impression of granules can frequently be seen. The surface of the polymorphonuclear leukocyte is thrown into ridges and elaborate ruffles and waves but is devoid of microvilli. Lymphocytes, macrophages, and mast cells that are within a certain distance (about 6 μM) of each other extend characteristic “direction-oriented processes” toward many of their nearest neighbors. These delicate projections arise from a roughly circular region of the cell circumference; they vary in length up to approximately 1.5 μM and it is suggested that they are related to communication between these free cells that do not join together into a tissue.     

Modified LDLs induce and bind to membrane ruffles on macrophages.

Macrophage foam cell formation in vitro requires uptake of modified low density lipoproteins (LDL) such as acetylated LDL (AcLDL) and moderately oxidized LDL (OxLDL), or beta-migrating very low density lipoprotein (betaVLDL), a naturally occurring lipoprotein. Incubation ofmacrophages with AcLDL and OxLDL resulted in stimulation of membrane ruffle formation, while betaVLDL primarily resulted in increased numbers of microvilli. Time-lapse Allen video enhanced contrast differential interference contrast (AVEC-DIC) light microscopy and correlative whole mount intermediate-voltage transmission electron microscopy (IVEM) was used to examine the dynamics ofAcLDL stimulated membrane ruffling and membrane ruffle ultrastructure. Stereo 3D surface replicas confirmed that AcLDL bound to these AcLDL-induced membrane ruffles. Quantification of the plasma membrane surface area after incubation with AcLDL, betaVLDL or LDL confirmed that AcLDL stimulated membrane ruffling, while betaVLDL and LDL stimulated microvilli formation. These studies suggest that modified LDLs induce circular membrane ruffles and modified LDLs bind to these ligand-induced membrane ruffles.     

Morphogenesis of the fetal membranes of the white-tailed deer

Morphogenesis of the fetal membranes of the white-tailed deer was studied throughout pregnancy. In placentomes, the long, branched, fetal villi occupied corresponding maternal crypts. The bases of the villi and the arching areas connecting them (arcades) were covered with high columnar cytotrophoblast, which apparently had phagocytosed material from the adjacent degenerating rims of the crypts. This arcade cytotrophoblast contained much glycogen and occasional mitochondria, free ribosomes, and pigment granules. Elsewhere, the columnar cytotrophoblast cells usually contained three to five rows of rod-shaped mitochondria and other cytoplasmic organelles. Interspersed among them were numerous binucleate giant cells which usually contained peripheral lace-like granular endoplasmic reticulum and many complex lipoprotein droplets. Cryptal epithelium, deep to the degenerate rims, was low columnar, had infranuclear osmiophilic lipid droplets, and sparsely distributed cytoplasmic organelles. The microvilli of cryptal and cytotrophoblastic epithelia interdigitated and appeared as a brush border under light microscopy. The microvilli and their PAS-positive mucopolysaccharide material appeared capable of holding uterine and chorionic epithelia together during pregnancy. The placentomes were epitheliochorial, but showed “intra-epithelial” capillaries. Interplacenomal uterine and cytotrophoblasitc epithelia resembled those of the placentomes. Their microvill were inundated by endometrial gland secretion (uterine milk). The cytotrophoblast contained pigment granules and much absorbed uterine milk. The amniotic epithelium showed short microvilli, complexly folded lateral plasma membranes, many desmosomes, abundant glycogen granules, foot processes and other cytoplasmic organelles.     

An ultrastructural study of normal human mammary epithelial cells in culture

The ultrastructure of normal human mammary cells cultured from post-weaning breast fluids is described. Cells from confluent monolayers in two week old cultures were studied. The epithelial nature of these cells was established by the demonstration of a well developed system of cell-to-cell interdigitation and numerous desmosomes. These cells also share with breast epithelial cells in vivo, polarity, with blunt short microvilli on the apical surface and an oriented arrangement of organelles in the basal and apical portions of the cells. The Golgi apparatus, which is the most highly developed organelle, is localized in the apical pole and contains substantial quantities of secretory material in the cisternae and vesicles. A variegated palisade of finely granular material mixed with tonofilaments is seen in the basal portion of the cells; many of these tonofilaments end in the terminal web of the desmosomes. The regular occurrence of these cells in breast fluids during the terminal phases of lactation suggests that their separation is a part of normal breast involution.     

Scanning and transmission EM of rat kidney following low dose mercuric chloride administration.

The development of necrosis and the subsequent regeneration of the proximal tubular epithelium located in the cortex and the outer medulla of the rat kidney following subcutaneous injection of 2 mg of mercuric chloride per kilogram of body weight was observed utilizing light micromicroscopy (LM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The cortical proximal tubules were largely free of injury. In the medullary proximal tubules, the residual, undamaged cells underwent a change in phenotype appearance involving loss of the microvillus border, a decrease in cell height, and an increase in cytoplasmic ribosomes. These cells phagocytosed luminal debris. With time the cell height gradually increased, specialized organelles returned, and the luminal microvilli progressed from short, sparse profiles, to tufts of longer microvilli and finally the brush border was completely reformed. Some kidneys contained calcified tubules which regenerated more slowly than damaged but uncalcified tubules. Similarly, the medullary segments of the proximal tubules regenerated more slowly than the juxtamedullary region. Clusters of epithelial cells were occasionally seen growing into the tubular lumina during regeneration. Marked intersitial leukocyte infiltrations were observed.     

Spatial distribution of cell adhesion molecules on the peritoneal surface in the cecal perforation‐induced peritonitis

For understanding the immunological functions of the peritoneum, spatial localization of integrins and their ligands was studied by immuno‐SEM on the peritoneal surface of mice with cecal perforation‐induced peritonitis. The cecal peritoneum 24 hr after perforation was stained with specific antibodies against LFA‐1, Mac‐1, VLA‐4, ICAM‐1, VCAM‐1, and fibronectin diluted with cold University of Wisconsin (UW) solution in conjunction with immuno‐gold labeling. The spatial localization of those cell adhesion molecules was detected by backscatter electron (BSE) imaging with field emission scanning electron microscope (FESEM). Numerous leukocytes with diverse surface ultrastructure were observed on the peritoneal surface by FESEM. Some leukocytes were in contact with mesothelial cells, and others adhered to the exposed underlying connective tissue. The BSE imaging showed the ubiquitous distribution of Mac‐1 on all membrane domains of leukocytes, i.e., cell body, ruffles, and microvilli. In contrast, predominant expressions of LFA‐1 and VLA‐4 were discernible on ruffles/microvilli of some leukocytes. The mesothelial cells remaining in the inflamed area expressed both ICAM‐1 and VCAM‐1 on their microvilli. The fibronectin was detected on presumable collagen fibers and/or fibrin over the exposed smooth muscle layer as well as on fibrin extending between leukocyte aggregation. The spatial microlocalization of integrins was clarified on the leukocytes emigrated in peritonitis, and their ligands were detected on the inflamed peritoneum. Anat Rec 264:219–227, 2001. © 2001 Wiley‐Liss, Inc.