The electron microscopy of normal human oesophageal epithelium.

Oesophageal biopsies were studied with the electron microscope. Three layers were identified, as in the light microscopy of the oesophageal epithelium: basal, prickle and funtional cell layers. A continuous basement membrane separated the lamina propria from the basal cells. The basal cell membrane carried hemidesmosomes, desmosomes and microvillous processes. Their cytoplasm contained the usual organelles plus free ribosomes and tonofirbrils. Prickle cells contained glycogen rosettes and many tonofilaments, and their cell membrane many microvillous and demosomal processes, in places elaborated into desmosome fields. In both these layers there was a wide intercellular space containing some particulate and membranous debris. The flattened cells of the functional layer had fewer desmosomes and microvilli but abundant glycogen and tonofilaments, and a narrow intercellular space. Membrane coating granules first reaching a maximum in the functional cell layer appeared in the upper prickle cell layer and few persisted into the surface cells. The apical cell membrane of the most superficial cells was thickened and had few small microvillous processes, which were covered with a filamentous "fuzzy" coat. No keratohyaline granules were present. Papillae of lamina propria contained capillaries, some with a fenestrated endothelium.     

Electronmicroscopic observations on epidermoid (squamous cell) carcinomas of the lung

Five epidermoid (squamous cell) carcinomas of the lung histopathologically diagnosed were ultrastructurally analysed; special attention was given to the poorly differentiated-immature areas of proliferation. Wide intercellular spaces between irregular cytoplasms with protrusions and microvilli, a high incidence of indentations of nuclear membranes, a large amount of nuclear bodies, shape, size and structure anomalies of mitochondria, a great number of desmosomes and of tonofilaments and tonofibril bundles and their relations with desmosomes and with the finger-like cytoplasmic expansions were noticed. A few secretory granules were also present in these poorly differentiated-immature areas of epidermoid carcinomas of the lung.     

Tumors of the respiratory tract observed at the German Primate Center, 1978–1994

Abstract: Eight spontaneous pulmonary tumors (four bronchiolar tubular adenomas, two bronchiolar adenocarcinomas, two squamous-cell carcinomas) occurred in a total of 54 adult tree shrews (Tupaia belangeri) of the GPC colonies between 1978 and 1994. The adenomas and adenocarcinomas consisted of tubularly or trabecularly arranged cuboidal to cylindrical cells interspersed with some PAS-positive goblet cells, thus resembling the epithelial lining of respiratory bronchioles of tree shrews. The two squamous-cell carcinomas probably originated from the pulmonary alveoles. Three more pulmonary tumors (one small-cell carcinoma, one bronchial adenoma, one squamous-cell carcinoma) developed in 409 adult callitrichids of the GPC colonies during the same period, and one more bronchial adenoma was observed in a common marmoset (Callithrix jacchus) of another colony located in Göttingen. With regard to the adenomas and squamous-cell carcinomas, a similar cellular origin with the tree shrews is assumed. The small-cell carcinoma possibly developed from the bronchial epithelium, provided a pathogenesis parallel to that of human small-cell carcinoma is suggested. Four of the tree shrew pulmonary adenomas/adenocarcinomas and the small-cell Ca were macroscopically visible as yellowish-grey nodules of 1 mm × 1 mm to 15 mm × 15 mm diameter, predominantly involving the main lobes (2 × right main lobes, 2 × left main lobes, 1 × all lobes). The pulmonary tumors of the other animals were below macroscopical detectability.     

The ultrastructure of metastatic adenocarcinoma in serous fluids. An aid in identification of the primary site of the neoplasm

Identification of the primary sites of metastatic adenocarcinomas is a diagnostic problem, particularly in cases of occult primary neoplasms. We studied the ultrastructural morphology of 16 metastatic adenocarcinomas that presented as effusions to establish organ-specific features that would characterize adenocarcinomas from various sites. The nine cases in which the site of the primary carcinoma was known included seven derived from the breast, one from the ovary and one from the colon. The primary site was unknown in seven cases at the time of presentation. After investigations, the primary site became known in five cases (lung, colon and appendix, one case each, and the ovary in two cases). Ultrastructurally diagnostic features could be detected in gastrointestinal, ovarian, bronchioloalveolar-cell and breast carcinomas. In gastrointestinal carcinomas, the presence of short microvilli with long rootlets was specific for the group. The lamellar inclusions of type II pneumocytes were diagnostic of bronchioloalveolar-cell carcinoma. The microvilli in ovarian carcinomas were long, slender and bushy, as in mesotheliomas; however, the cells lacked the perinuclear condensation of tonofilaments seen in the latter. Breast carcinomas were associated with numerous intracytoplasmic lumina, electron-dense granules and aggregates of small vesicular bodies. We conclude that ultrastructural examination of adenocarcinomas in serious fluids can help to identify the primary site of certain neoplasms or at least shorten the list of possibilities. This may reduce costs and minimize the discomfort patients have to undergo by curtailing extensive invasive investigations in search of unknown primary neoplasms.     

Junctional complexes in fetal rat small intestine during morphogenesis

During the 7 days prior to birth (Days 15–22), the small-intestinal epithelium of the fetal rat changes from primitive stratified to simple columnar epithelium which lines villi at 19 days. As seen in thin sections, this remodeling involves rapid formation of new junctional complexes and secondary lumens between epithelial cells deep in the stratified epithelium. We have examined the formation and reorganization of junctional complexes in proximal small intestine of 15- to 19-day fetal rats using freeze-fracture techniques. On Days 15 and 16 the epithelial cells surrounding the primary lumen are joined by conventional apical junctional complexes. Additionally, macular junctional complexes are located on deeper epithelial cells. These display no polarity and consist of tight-junction strands intermixed with gap junction-like arrays and desmosomes. On Days 17 and 18 nonluminal, macular junctional complexes enlarge and secondary lumens develop within their centers. As the secondary lumens expand, microvilli appear and the junctional complex polarizes about the secondary lumen; tight-junction strands become parallel to the luminal surface, desmosomes migrate basolaterally, and gap junction-like arrays disappear. By Day 19, secondary lumens have fused with the primary lumen; concomitant loss of apical cells results in formation of villi lined by simple columnar epithelium with polarized apical tight junctions. The observed pattern of junctional complex formation may play a role in maintaining barrier function and establishing epithelial cell polarity as the epithelium is remodeled.     

Dry mass, DNA and non-histone protein determinations in lung cancer cells

Summary Cell nuclei from two biopsies of bronchial mucosa, seven squamous-cell carcinomas and six small-cell carcinomas of the lung were investigated. DNA and non-histone protein (NHP) content were simultaneously determined in Feulgen—Naphthol Yellow S-stained smears by means of multiple plug cytophotometry. In addition, the nuclear dry mass of cells originating from the same populations was measured by interference microscopy.DNA histograms of carcinomas were characterized by DNA stemlines being situated in the diploid range in four out of six small-cell carcinomas and in the hyperdiploid to hypertetraploid range in six out of seven squamous-cell carcinomas.Polyploid values (up to 8 c) were seldom found in small-cell carcinomas whereas squamous-cell carcinomas showed a broader dispersion approaching the 16 c level.The similarity of the NHP distributions with the DNA histograms was more marked in small-cell carcinomas than in the squamous-cell carcinomas. In comparison with the NHP distributions of normal bronchial epithelial cells, those of carcinomas were shifted to higher values. The increased NHP content was found to be a more prominent sign of malignancy in small-cell carcinomas than the DNA mass. The increase in nuclear dry mass in carcinomas was mainly caused by the accumulation of NHP in tumour cell nuclei.     

Intracellular lumen in cultured hepatocytes of rats. Study of an original cytoplasmic infrastructure

A few hours after plating, isolated rat hepatocytes reassociate into clusters and differentiate intercellular cavities bordered by junctional complexes. These structures show a great resemblance to bile canaliculi seen in vivo. Intracellular lumens surrounded by microvilli are observed in the cytoplasm of some cultured hepatocytes. The formation of these structures, which contain an osmiophilic substance, probably results from modifications in the functioning of the secretory apparatus. It can be speculated that these intracellular lumens may contribute to the formation of new canaliculi differentiated between reassociated cells.     

Morphometric and ultrastructural features of the mare oviduct epithelium during oestrus

Morphometric, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) investigations have displayed regional differences in the mare oviductal epithelium. The entire mucosa of the oviduct was lined with a pseudostratified epithelium, which consisted of two distinct cell types, ciliated and non-ciliated. Ciliated cells were predominant in the three different segments of the oviduct and their percentage increased from fimbriae to ampulla and significantly decreased in the isthmus. SEM revealed in the infundibulum finger-like mucosal folds, some of them interconnected, in the ampulla numerous and elaborated branched folds of the mucosa, whereas the isthmus displayed a narrow lumen, short and non-branched mucosal folds. In the ampulla and isthmus the majority of non-ciliated cells showed apical blebs provided or not of short microvilli. TEM displayed different ultrastructural features of ciliated and non-ciliated cells along the oviduct. Isthmus ciliated cells presented a more electron-dense cytoplasm than in infundibulum and ampulla cells and its cilia were enclosed in an amorphous matrix. The non-ciliated cells of infundibulum did not contain secretory granules but some apical endocytic vesicles and microvilli coated by a well developed glycocalyx. Non-ciliated cells of ampulla and isthmus contained secretory granules. Apical protrusions of ampulla displayed two types of secretory granules as well as occasional electron-lucent vesicles. Isthmus non-ciliated cells showed either electron-lucent or electron-dense cytoplasm and not all contained apical protrusions. The electron-dense non-ciliated cells displayed microvilli coated with a well developed glycocalyx. Three types of granules were observed in the isthmus non-ciliated cells. The regional differences observed along the epithelium lining the mare oviduct suggest that the epithelium of the each segment is involved in the production of a distinctive microenvironment with a unique biochemical milieu related to its functional role.     

Classification of lung carcinoma by means of digital nuclear image analysis

An investigation was performed of the maximum discriminating efficiency for each subgroup of digital nuclear image features and of the overall classification of nuclei from three types of human lung carcinomas in histologic sections: adenocarcinoma, small-cell carcinoma and squamous-cell carcinoma. The results indicate that, for each subgroup of features, the nuclei of the small-cell carcinomas are generally "correctly" classified in a higher percentage (80% to 100%) than are the nuclei of the adenocarcinomas (46% to 74%) and squamous-cell carcinomas (29% to 68%). The discriminant analysis for the overall classification selected features from most of the subgroups, suggesting that it is useful to perform nuclear image analysis with many subgroups having different properties. The overall classifications for the nuclei of the adenocarcinomas, small-cell carcinomas and squamous-cell carcinomas were, respectively, 81.4%, 93.2% and 74.7%. Before this technique can be applied to histopathologic diagnosis, a larger number of unselected lung carcinomas must be evaluated.     

The Olfactory System in the Hagfish Myxine glutinosa

The apical part of the olfactory epithelium in Myxine glutinosa was investigated by optical and electron microscopy. This part of the epithelium consists of supporting cells and two types of olfactory receptor cells, i.e., ciliated receptor cells and microvillous receptor cells. The olfactory cilia have a 9 + 0 pattern of the microtubules, occasionally with one pair of the doublets dislocated towards the center of the cilium. Giant cilia were observed. The supporting cells bear microvilli and are rich in tonofilaments. The supporting cells also have a secretory function, their secretion consisting mainly of acid mucopolysaccharides. An asymmetrical type of desmosome was found between the olfactory receptor cells and the supporting cells.     

Ultrastructure of macrocellular (large cell) carcinomas of the lung

The electronmicroscopic investigation of five lung tumors histodiagnosed as macrocellular carcinomas showed the ultrastructural monomorphism of large, variedly shaped neoplastic cells, lack of intercellular junctions, voluminous nuclei with many indentations of nuclear membrane, dispersed euchromatin, large and multiple nucleoli, and nuclear bodies. A reduced number of cytoplasmic organelles was characteristic for these cells, represented mainly by mitochondria, rare rough endoplasmic reticulum, free ribosomes rare Golgi vesicles and flattened tubules, and a various amount of tonofilaments. These features characterized the poorly differentiated proliferation forming these tumors. The elements of differential diagnosis from other poorly differentiated lung tumors (epidermoid and cylindrocubic) are discussed, allowing the consideration of this proliferation type with repressed differentiation and maturation as a real one in the framework of lung carcinomas.     

Ultrastructure of the main excretory duct of the cat submandibular gland

The main excretory ducts (MED's) from the submandibular gland of adult cats were examined by electron microscopy. The ducts consisted of a pseudostratified epithelial lining surrounded by abundant connective tissue and numerous, small, longitudinally-oriented blood vessels. The taller epithelial cells were closely coherent, without the luminal clefts between adjacent cells that are characteristic of rat MED's. In the cat, these cells lacked basal membrane specialization, but showed considerable lateral interdigitation. Some microvilli were present on the apical surface. In a'few rare cells, the luminal surface bore cilia of typical appearance. The smaller, pyramidal basal cells had irregular basal surfaces that gave rise to one or more long cytoplasmic processes. The basal surface of the pyramidal cells was studded with hemidesmosomes. The cytoplasm contained abundant tonofilaments, which sometimes aggregated in prominent perinuclear bundles. Occasional goblet cells were present in the duct wall. MED's perfused either in situ or in a perfusion chamber with Locke's solution also were studied. Even after perfusion of 160 minutes duration, the ultrastructure of the ductal epithelium showed remarkably few alterations. The MED model system thus remains stable long enough to carry out physiological experiments which may produce ultrastructural alterations.     

光唇鱼消化道的形态结构特征

采用解剖及石蜡切片显微技术,观察研究了光唇鱼消化道的形态结构特征。消化道由口咽腔、食道、肠构成。口下位、马蹄形,无颌齿,具咽齿,齿式为4/4。舌较小,前端游离,舌粘膜表层为复层鳞状上皮,有较多的杯状细胞和味蕾。食道及肠均由粘膜层、粘膜下层、肌层及外膜构成。食道内皱襞发达,粘膜层有大量杯状细胞。肠道盘曲,由前、中、后肠组成,肠长/体长为1.84±0.24;前肠管腔较大,中、后肠管腔渐变小;前、中肠皱襞及纹状缘比后肠发达;前肠及后肠杯状细胞较少,中肠杯状细胞较多。光唇鱼消化道的形态结构特征与其食性相适应。     

Ultrastructure of the dorsal hemal vessel in the sea-cucumber Parastichopus tremulus (Echinodermata: Holothuroidea)

The dorsal hemal vessel in Parastichopus consists of three distinct layers: An outer flagellated epithelium, an intermediate circular muscle layer and an inner connective tissue layer which nearly fills the lumen. Between the outer and intermediate layer runs strands of nerve fibers. Each coelomic epithelial cell has one flagellum and some microvilli. It contains a number of different vacuoles and a few bundles of tonofilaments. One special type of vacuole which contains well organized myofilaments is described. Each muscle cell contains one myofibril of a non-striated type consisting of thick and thin filaments and no dense bodies. The sarcoplasmic reticulum is poorly developed, but peripheral coupling are frequently found. The muscle cells in the dorsal hemal vessel of Parastichopus are compared with other muscles in echinoderms and muscle types described in other phyla.     

Morphogenetic characteristics of the aggregates formed in epithelial and mesenchymal recombinations of the lungs from intact and urethane-exposed mouse embryos

A study was made of the morphogenesis of organotypic aggregates obtained by epithelial mesenchymal recombinations from the lungs of embryonic mice, intact and treated with urethane. Normal growth and differentiation of organotypic structures were observed in long-term cultures of aggregates obtained by recombinations of the lung epithelium (E) and mesenchyma (M) from intact (i) embryonic mice (EiMi). Hyperplasia and squamous-cell metaplasia (with or without keratinization) of the epithelium were found in aggregates obtained from E and M of the treated mouse embryos (EtMt) and in aggregates obtained by recombinations of lung E and M from intact and treated embryos (EtMi, EiMt). The data obtained suggest that the alterations in epithelial mesenchymal interactions are of great significance for transplacental lung blastomogenesis and that the mesenchymal lung cells play an important part in mediation of the transplacental carcinogenous effects on epithelial target cells via subsequent epithelial mesenchymal tissue interactions.     

Continual neurogenesis of vomeronasal neurons in vitro.

We developed a culture system of vomeronasal neurons in which continuous degeneration and regeneration of axon bundles were observed. Partially dissociated vomeronasal cells from rat embryonic day 15 were grown in culture and formed a miniature vomeronasal-like epithelium. We called these structures vomeronasal pockets. They contained both vomeronasal neurons and supporting cells. They formed a spherical structure with a central cavity where microvilli protruded from supporting cells. Mature vomeronasal neurons with well-developed microvilli were not observed in the vomeronasal pocket. The time period between degeneration of axon bundles and the next was about 2 weeks. When vomeronasal pockets were incubated with 5 microgram/mL aphidicolin, an inhibitor of cell division, regeneration of axon bundles was not observed after degeneration. These results suggest that vomeronasal neurons in culture undergo continuous regeneration but do not fully mature. In this culture system, vomeronasal pockets survived for over 1 year.     

Differentiation of epithelial cells in the urinary tract

Uroplakins, cytokeratins and the apical plasma membrane were studied in the epithelia of mouse urinary tract. In the simple epithelium covering the inner medulla of the renal pelvis, no uroplakins or cytokeratin 20 were detected and cells had microvilli on their apical surface. The epithelium covering the inner band of the outer medulla became pseudostratified, with the upper layer consisting of large cells with stalks connecting them to the basal lamina. Uroplakins and cytokeratin 20 were not expressed in these cells. However, some superficial cells appeared without connections to the basal lamina; these cells expressed uroplakins Ia, Ib, II and III and cytokeratin 20, they contained sparse small uroplakin-positive cytoplasmic vesicles and their apical surface showed both microvilli and ridges. Cytokeratin 20 was seen as dots in the cytoplasm. This epithelium therefore showed partial urothelial differentiation. The epithelium covering the outer band of the outer medulla gradually changed from a two-layered to a three-layered urothelium with typical umbrella cells that contained all four uroplakins. Cytokeratin 20 was organized into a complex network. The epithelium possessed an asymmetric unit membrane at the apical cell surface and fusiform vesicles. Umbrella cells were also observed in the ureter and urinary bladder. In males and females, the urothelium ended in the bladder neck and was continued by a non-keratinized stratified epithelium in the urethra in which no urothelial cell differentiation markers were detected. We thus show here the expression, distribution and organization of specific proteins associated with the various cell types in the urinary tract epithelium.W. Mello Jr. thanks FAPESP, São Paulo, Brazil for financial support.     

Immunocytologic diagnosis of small-cell lung cancer in imprint smears.

Imprints of histologic or autopsy specimens from 12 small-cell lung cancers (SCLCs), 82 non-SCLCs (50 adenocarcinomas, 25 squamous-cell carcinomas, 1 adenosquamous carcinoma and 6 large-cell carcinomas), 2 carcinoid tumors, 1 malignant lymphoma and 8 metastatic carcinomas were examined immunocytologically for the presence of cluster 1 SCLC antigen (neural-cell adhesion molecule: N-CAM), chromogranin A, Leu-7, neuron-specific enolase (NSE) and gastrin-releasing peptide (GRP). The monoclonal antibodies NCC-LU-243 and NCC-LU-246, which are reactive with cluster 1 SCLC antigen/N-CAM, diffusely stained the cell membranes of all SCLCs and carcinoid tumors (100%) and diffusely and focally stained those of two of the large-cell carcinomas, two of the adenocarcinomas, two of the squamous-cell carcinomas and the one adenosquamous carcinoma. Malignant lymphoma and metastatic carcinoma were negative for this antigen. A few cases of large-cell carcinoma, adenocarcinoma, squamous-cell carcinoma and adenosquamous carcinoma were also stained with these antibodies, which may indicate a neuroendocrine differentiation. However, these tumors were different from SCLCs in that their positive tumor cell population was definitely smaller than that in SCLC, in which almost all tumor cells were positive. This confirmed the usefulness of antibodies against cluster 1 SCLC antigen for the immunocytologic diagnosis of SCLC and carcinoid tumor in imprint smears. Chromogranin A, GRP, NSE and Leu-7 were not useful in immunocytologically differentiating the imprints from these cases since only a few tumor cells were reactive with these antibodies. The antibodies against cluster 1 SCLC antigen/N-CAM can also be applied to cytologic preparations of sputum, pleural fluid and fine needle aspirates stained routinely by the Papanicolaou method since the antigen is preserved in such alcohol-fixed smears.     

Expression of keratins during experimentally induced carcinogenesis in hamster cheek pouch visualized polyclonal and monoclonal antibodies

Summary We obtained immnohistochemical profiles of several keratin proteins during experimentally induced carcinogenesis in hamster cheek-pouch mucosa using a polyclonal antibody (TK; detecting keratins with molecular masses of 41 65 kilodalton) and two monoclonal antibodies (KL1, 55- to 57-kilodalton keratins; PKK1; 40-, 45- and 52.5-kilodalton keratins). The squamous epithelium of normal pouch mucosa exhibited positive TK staining in all layers. KL1 staining in the spinous layer and PKK1 staining in the basal layer, thus indicating a regional or zonal distribution pattern. Epithelia undergoing basal hyperplasia showed irregular localization of PKK1 binding, while hyperkeratinized lesions exhibited the binding pattern found in normal epithelium. In case of epithelial dysplasia, there was reduced KL1 staining in spinous cells and decreased PKK1 staining in the basal and parabasal layers. Papillomas exhibited a rather zonal distribution of keratin staining. All squamous-cell carcinomas, irrespective of their degree of keratinization and infiltration pattern, showed slight or no PKK1 staining. Such lesions were only positive for KL1-detectable keratins in keratinizing tumour cells and exhibited an irregular distribution of TK binding. The expression of keratin proteins during carcinogenesis in hamster cheekpouch mucosa may parallel that of keratins in human squamous-cell carcinomas originating in the oral mucosa.     

An ultrastructural and immunohistological study of the rat olfactory epithelium: Unique properties of olfactory sensory cells

The olfactory epithelium contains three cell types: basal cells, supporting cells and sensory neurons. Electron microscopy as well as immunofluorescence microscopy with intermediate-filament antibodies were used to study the rat olfactory epithelium in order to obtain more information about these different cell types and to try to investigate their histogenetic origins. We found mitoses in the basal-cell layer, as well as multiple centrioles and tonofilaments in some basal cells. As revealed by electron microscopy, the supporting cells contained tonofilaments and reacted strongly with antibodies to keratin, in line with their known epithelial nature. When antibodies to other intermediate-filament types were used, i.e. glial fibrillary acidic protein, vimentin, desmin and neurofilaments, no reaction was seen in the cells of the olfactory epithelium, with the exception of occasional staining of a few axons in the subepithelial layer by neurofilament antibodies. In particular, the cell bodies, dendrites and most axons of the sensory neurons were negative for a variety of antibodies against neurofilaments. Olfactory sensory neurons therefore belong to the very few cells in adult animals which seem to lack intermediate filaments. We discuss whether this finding is related to the fact that these cells are also unique among neurons in that they are not permanent cells but constantly turn over.