scispace - formally typeset
Search or ask a question

Showing papers on "Apical cytoplasm published in 1992"


Journal ArticleDOI
TL;DR: It is concluded that two cell lines exhibiting different grades of differentiation as well as a different potency to metastasize can be established from the same primary tumor, and that these cell lines represent a suitable model for further study of the cell biology of human pancreatic adenocarcinoma.
Abstract: From a liver metastasis of a human pancreatic adenocarcinoma, we have established cell lines for studying the cell biology of this tumor. We obtained two cell lines with different morphological, chromosomal and functional properties. One of them, named PaTu 8988s, revealed a solid growth in nude mouse xenografts with cells exhibiting only occasional polar organisation of the cytoplasm. In general, no apical or basolateral plasma membrane domains could be distinguished and the sparse organelles were randomly distributed throughout the cytoplasm. Secretory products, such as mucin, were weakly stained histochemically or were completely absent. Transglutaminase (TGase) activity used as a marker for cellular differentiation was low in these cells. The other cell line, named PaTu 8988t, grew tumors composed of tubular structures when injected subcutaneously into nude mice. Cells were polarized with distinct apical and basolateral plasma membranes and the cytoplasmatic organelles were arranged with the nucleus in the lower part of the cell, while the apical cytoplasm contained the Golgi complex and numerous secretion granules. A high content of mucin was stained histochemically and transglutaminase activity was ten times higher than in PaTu 8988s. Comparing the chromosome number per metaphase plate, both cell lines showed a major peak, with 45-55 chromosomes per metaphase plate in PaTu 8988s and about 110-120 chromosomes per metaphase plate in PaTu 8988t. When the two cell lines were injected intravenously into the tail vein of nude mice, only PaTu 8988s developed metastases localized exclusively in the lung, whereas PaTu 8988t produced no metastases in any organ. We conclude, that two cell lines exhibiting different grades of differentiation as well as a different potency to metastasize can be established from the same primary tumor, and that these cell lines represent a suitable model for further study of the cell biology of human pancreatic adenocarcinoma.

123 citations


Journal ArticleDOI
TL;DR: The stage-dependent apical Sertoli cell cytoplasmic dynein immunofluorescence, in conjunction with the previously reported orientation of SERToli cell microtubules (slow-growing ends toward the lumen) and peak secretion of androgen-binding protein and transferrin, is consistent with the hypothesis that cy toplasmo-dynein is involved in Sertolis cell protein transport and secretion.
Abstract: To examine the possible role of microtubule-based transport in testicular function, we used immunofluorescent techniques to study the presence and localization of the microtubule mechanoenzymes cytoplasmic dynein (a slow-growing end-directed motor) and kinesin (a fast-growing end-directed motor) within rat testis. Cytoplasmic dynein immunofluorescence was observed in Sertoli cells during all stages of spermatogenesis, with a peak in apical cytoplasm during stages IX-XIV. Cytoplasmic dynein immunofluorescence was also localized within Sertoli cells to steps 9-14 (stages IX-XIV) germ cell-associated ectoplasmic specializations. In germ cells, cytoplasmic dynein immunofluorescence was observed in manchettes of steps 15-17 (stages I-IV) spermatids, and small, hollow circular structures were seen in the cytoplasm of step 17 and step 18 spermatids during stages V and VI. Kinesin immunofluorescence was observed in manchettes of steps 10-18 spermatids (stages X-VI). The stage-dependent apical Sertoli cell cytoplasmic dynein immunofluorescence, in conjunction with the previously reported orientation of Sertoli cell microtubules (slow-growing ends toward the lumen) and peak secretion of androgen-binding protein and transferrin, is consistent with the hypothesis that cytoplasmic dynein is involved in Sertoli cell protein transport and secretion. Further, the localization of cytoplasmic dynein and kinesin to manchettes is consistent with current hypotheses concerning manchette function.

82 citations


Journal Article
TL;DR: The results indicate that BFA rapidly inhibits secretion and causes dismantling of the Golgi stacks in pancreatic acinar cells, but clusters of vesicles consisting of bona fide Golgi remnants persist even with prolonged exposure to BFA, indicating that in the exocrine pancreas there is a dissociation of BFA's effects on the exocytic pathway.

59 citations


Journal ArticleDOI
TL;DR: It is concluded that necrosis is the dominant type of cell death of the follicular cells during atresia, and a small fraction of cells seems to die by apoptosis.
Abstract: The structure of follicular layer of growing and atretic follicles in the ovary of the domestic goose, was studied by electron microscopy In small follicles, the wall is lined with a narrow layer of tightly packed small, cuboidal cells separated from the thecal tissue by the basal lamina During growth, they transform into tall, columnar cells arranged in a single row The cells display several peculiar ultrastructural features First, annulate lamellae are commonly observed Second, cytoplasmic dense-cored granules accumulate in close association with fenestrated cisternae and networks of tubuli derived from the RER They consist of spheres and strands of amorphous substance of unknown origin Third, the cells contain many transosomes, a unique organelle of the avian follicle cell consisting of a dense plaque associated with ribosome-like particles The mature forms of transosomes are located at the tips of lateral and apical cell projections, while bodies thought to be their precursors, are found in the apical cytoplasm In follicles larger than 8 mm in diameter, most of the transosomes and their precursors have disappeared Follicular atresia occurs in all of the size-classes of follicles investigated A loss of transosomes (in follicles up to 8 mm in diameter) and an accumulation of lipid droplets are the first atretic events detectable by electron microscopy Morphologic features, including deep nuclear indentations, accumulation of lipid droplets frequently encireled by membrane whorls, dilation and disintegration of RER cisterns, swelling of mitochondria and accumulation of dense irregular masses of unknown origin in the cytoplasm, are taken as evidence for advanced degradation We conclude that necrosis is the dominant type of cell death of the follicular cells during atresia However, a small fraction of cells, characterized by dark condensed cytoplasm, seems to die by apoptosis

44 citations


Journal ArticleDOI
TL;DR: The selection of immature crypt cells by the intracellular Campylobacter-like organisms for entry and multiplication may represent a remarkable microbial adaptation associated with local immunomodulation and enhanced bacterial survival.
Abstract: The ileum, colon, and mesenteric lymph nodes of pigs naturally affected by either of the two major forms of proliferative enteropathy, namely, intestinal adenomatosis or hemorrhagic enteropathy, were examined for immunocytological responses to infection by immunocytochemistry, using antibodies directed against elements of the porcine immune system. In both forms, there was mucosal proliferation of immature enterocytes which lacked substantial major histocompatibility complex class II expression and a marked accumulation of immunoglobulin A (IgA) at the apical cytoplasm of affected enterocytes in association with intracellular Campylobacter-like organisms. In intestinal adenomatosis, there was only a mild infiltration of CD8+ and CD25+ T cells in the intestinal lamina propria. In hemorrhagic enteropathy, there was a moderate infiltration of CD8+ and CD25+ T cells and IgM+ B cells in the lamina propria. In rats and humans, villous enterocytes are thought to act as antigen-presenting cells, with major histocompatibility complex class II molecules present on their surface, capable of initiating a T-cell response (particularly of CD8+ T cells) in response to bacterial antigens. Therefore, the selection of immature crypt cells by the intracellular Campylobacter-like organisms for entry and multiplication may represent a remarkable microbial adaptation associated with local immunomodulation and enhanced bacterial survival. The accumulation of IgA within affected enterocytes may represent a reduced capability of the cells to process nonspecific IgA or an accumulation of specific IgA.

44 citations


Journal ArticleDOI
A. Gebert1, G. Hach1
TL;DR: The hypothesis that the membranous epithelial cells in the lymphoepithelium of rabbit BALT are analogous with intestinal M-cells, which in rabbit Peyer's patches and appendix are selectively labelled by vimentin antibodies, is supported.
Abstract: The lymphoepithelium covering the bronchus-associated lymphoid tissue (BALT) of the rabbit lung was studied with monoclonal antibodies against vimentin, using the indirect immunoperoxidase technique. In the lymphoepithelium single cells which had a membranous apical cytoplasm and engulfed intraepithelial lymphocytes were vimentin-immunoreactive. All other epithelial cells of the lymphoepithelium and of the surrounding airway epithelium did not bind vimentin antibodies. The results support the hypothesis that the membranous epithelial cells in the lymphoepithelium of rabbit BALT are analogous with intestinal M-cells, which in rabbit Peyer's patches and appendix are selectively labelled by vimentin antibodies.

30 citations


Journal ArticleDOI
TL;DR: Ciliogenic cells in early stages of ciliogenesis contained secretory granules-like vesicles in the apical cytoplasm, suggesting that the ciliated cells are differentiated from secretory cells in the late secretory phase on demand.
Abstract: Ciliogenesis has been investigated in the human oviduct epithelium during the normal menstrual cycle. Both centriolar and acentriolar pathways were involved in the replication of basal bodies. The centriolar pathway, in which procentrioles generate with the aid of preexisting diplosomes, played a minor role in the human oviduct. In the acentriolar pathway, fibrous granules were the first structure which appeared in the course of ciliogenesis and they initially occurred in association with the Golgi apparatus or free ribosomes. Subsequently deuterosomes arose in the aggregates of fibrous granules or apart from fibrous granules, and then microtubules-containing procentrioles originated around deuterosomes. Newly formed centrioles migrated to the apical cytoplasm with accompanying deuterosomes, and ciliary shafts extended first at the periphery of the luminal surface of ciliogenic cells. Deuterosomes as well as fibrous granules were considered to be related to the rootlet formation. Replicaion of basal bodies and protrusion of ciliary shafts mostly occurred during the proliferative phase of the menstrual cycle; however, a small number of fibrous granules indicating the ciliogenesis were still observed in some ciliated cells during the secretory phase. Ciliogenic cells in early stages of ciliogenesis contained secretory granules-like vesicles in the apical cytoplasm, suggesting that the ciliated cells are differentiated from secretory cells in the late secretory phase on demand.

29 citations


Book ChapterDOI
TL;DR: This chapter highlights zymogen granules (ZGs) of pancreas and the parotid gland and describes the overall variations of the ZG compartment and the variation of the granule size under a variety of physiological conditions.
Abstract: Publisher Summary This chapter highlights zymogen granules (ZGs) of pancreas and the parotid gland. It describes the overall variations of the ZG compartment and the variations of the granule size under a variety of physiological conditions. The chapter also examines the origin and fate of ZGs as observed by cytochemical methods and summarizes the contribution of freeze–fracture techniques to the definition of the ZG membrane architecture. The electrophysiological properties of ZGs and the influence of the cytoskeleton on secretion are discussed. The pancreas and the parotid gland process their macromolecular products by cisternal packaging and exocytosis. The size distribution of the ZGs in the parotid gland cells shows some points of similarity with that observed in the pancreas. During exocytosis the ZG membrane fuses with the luminal plasmalemma, allowing the discharge of granule content. The cytoskeleton controls the movement of ZGs toward the cell apex. The nature of these interactions may be much more complex than a simple ZG alignment in the apical cytoplasm. The life of a ZG starts in the trans-Golgi saccule, in the form of condensing vacuole (CV). Both size and electron opacity of the forming CV are highly variable.

25 citations


Journal ArticleDOI
TL;DR: In the transgenic TG.SH mice, occasional unilateral, but more frequently bilateral exophthalmos due to hyperplasia of the intraorbital (Harderian) lacrimal gland was observed, and parotid tumours developed later, identified these neoplasms as aciniccell carcinomas that mimic the human salivary gland acinic cell carcinoma faithfully.
Abstract: In the transgenic TG.SH (mouse mammary tumour virus/v-Ha-ras) mouse, designed to develop mammary tumours, occasional spontaneous salivary gland tumours have been reported, predominantly in males. The incidence and histomorphology of salivary gland tumours in 73 TG.SH mice were surveyed and in total, 21.9% developed both overt and microscopic parotid tumours. The majority developed between 73 and 150 days of age. In 31.5% of the TG.SH mice, occasional unilateral, but more frequently bilateral exophthalmos due to hyperplasia of the intraorbital (Harderian) lacrimal gland was observed. In 70% of these animals, parotid tumours developed later. Since Harderian gland hyperplasia, occurring as early as 5 weeks of age, preceded the development of palpable salivary gland lesions, this stigma is useful for the early selection of animals likely to progress to tumour formation. Before tumour-bearing transgenic mice are considered to be suitable models of human neoplastic disease, morphological characterization is necessary to ensure that the tumours are histologically representative of the human lesions for which they are potential models. In this study, all parotid tumours consisted of acinar-like glandular structures with central lumina discernible by electron microscopy. Ultrastructurally, secretory granules evident in the apical cytoplasm of the tumour cells resembled the zymogen granules of the normal parotid acinar cell, and some cells had a prominent complement of rough endoplasmic reticulum. These features, along with focal amylase expression detected immunohistochemically in some parotid tumours, identified these neoplasms as acinic cell carcinomas that mimic the human salivary gland acinic cell carcinoma faithfully.

25 citations


Journal ArticleDOI
TL;DR: Post-embedding colloidal gold labeling was used to examine the intracellular localization of IgG in the jejunal enterocytes of miniature piglets suckled for 2 hr and revealed that the most sensitive technique for IgG detection was the streptavidin bridge-gold technique.
Abstract: In ungulates, intestinal absorption of maternal immunoglobulins from colostrum plays a vital role in the acquisition of passive immunity during early neonatal life. In the present study we used post-embedding colloidal gold labeling to examine the intracellular localization of IgG in the jejunal enterocytes of miniature piglets suckled for 2 hr. Quantitation of the immunolabeling revealed that the most sensitive technique for IgG detection was the streptavidin bridge-gold technique. In this method, the LR White-embedded sections were labeled sequentially with biotinylated anti-porcine IgG, streptavidin, and biotinylated BSA conjugated to 10-nm colloidal gold. With this approach, we found the following sequence of maternal IgG accumulation: passage of IgG from colostrum through the brush border; binding to the apical plasma membrane; uptake in noncoated pits and invaginations; transport in endocytotic vesicles; and accumulation in granules in the apical cytoplasm.

21 citations


Journal ArticleDOI
TL;DR: The results show that the various hormone regimes produce characteristically different MF configurations and that this component of the cytoskeleton appears to be under the control of a delicate hormone balance within these uterine cells.
Abstract: This study investigates the interaction of hormones and the cytoskeleton within the apical cytoplasm of uterine epithelial cells of the rat. The effects of the hormones estradiol-17 beta and progesterone on the microfilament configuration were studied using myosin subfragment 1 (S1) decoration of actin microfilaments (MF) and transmission electron microscopy. In control ovariectomized animals, a sparse MF distribution was found in the apical cytoplasm underlying short microvilli with S1-decorated core MF. Hormone treatment experiments consisted of injecting ovariectomized rats with either progesterone or estradiol-17 beta. For the study of the MF configuration accompanying an apical surface primed for blastocyst receptivity, progesterone treatment was immediately followed by a single dose of estradiol-17 beta. The long, regular microvilli associated with estradiol only treatment contained bundled, decorated MF with tightly bundled rootlets. Progesterone alone produced numerous short microvilli with decorated core bundle MF and pronounced rootlets that frequently appeared splayed. The irregular microvilli and luminal surface of the uterine epithelial cells associated with the receptivity hormone sequence contained variable MF configurations, including MF bundles, networks, and areas with a "felted" appearance. The results show that the various hormone regimes produce characteristically different MF configurations and that this component of the cytoskeleton appears to be under the control of a delicate hormone balance within these uterine cells. The responses of uterine MF to specific regimes of steroid hormones used in this study are not only important for the understanding of the mechanisms at work during early pregnancy, but also contribute to the body of knowledge concerning the ways in which hormones in general effect the cytoskeleton of target cells.

Journal ArticleDOI
TL;DR: The repertoire of differentiating potency of mammalian and avian pineal cells has been examined utilizing cell culture technique and it has been found that tyrosinase is expressed from the beginning of pineal formation and that its expression is stage‐specific and site‐specific.
Abstract: The repertoire of differentiating potency of mammalian and avian pineal cells has been examined utilizing cell culture technique. Skeletal muscle fibers are differentiated from pineal cells of the rat under the usual culture condition and from those of quail under hypertonic conditions. Myogenesis of pineal cells may be explained from the ontogeny of the pineal body. Anlagen of a pineal body are situated in bilateral cephalic neural folds, which also supply multipotent neural crest cells. In some conditions, almost all quail pineal cells are able to differentiate into pigmented epithelial cells and/or lens cells. Opsin containing cells found in culture of rat pineal cells may be in a similar category reflecting the “third eye”: the phylogenetic ancestor of the pineal body of avian and mammalian species. Neuron-like cells have also been reported and neuronal morphology has been intensified under the effect of testicular hyaluronidase. The cytodifferentiation described above is suggested to be different expressions of a single type of progenitor cells in the pineal body. In relation to multipotentiality of pineal cells, the original differentiating state of pineal cells is interesting; it has been found that tyrosinase is expressed from the beginning of pineal formation and that its expression is stage-specific (during embryonic period) and site-specific (predominance in the dorsal half of the pineal body and in the apical cytoplasm of the pineal cell). In the 8 day quail embryo used for culture studies, three differentiating states as to tyrosinase are noticed. However, the distinction may be apparent, as even the cells negative in tyrosinase in this stage are still ready to express tyrosinase in the suitable culture condition. Pineal cells are flexible and surprisingly susceptible to environmental factors and useful for the study of cell differentiation in general. © 1992 Wiley-Liss, Inc.

Journal ArticleDOI
TL;DR: These results demonstrated marked changes in keratin expression and post-translational processing taking place at key stages of intestinal development.
Abstract: We have investigated keratin expression in fetal, newborn and adult rat intestines by immunofluorescence staining, immunoblotting of two-dimensional gels and Northern blot analysis of total cellular RNAs. Keratin-type intermediate filaments, composed predominantly of keratin no. 19, were observed already in the undifferentiated stratified epithelium present at 15-16 days of gestation. The marked maturation and differentiation of the epithelium taking place at 18-19 days of gestation was characterized by the appearance of the differentiation-specific keratin no. 21 and by a significant increase in the relative amount of keratin no. 8. The keratin pattern typical of adult villus cells became established at the time of birth, and was marked by a considerable increase in the complexity of the keratin-related polypeptides detected on two-dimensional gels, indicative of extensive post-translational modification of all keratins. Starting at 20 days of gestation there was a major increase in the relative abundance of mRNAs coding for keratin nos. 8, 19 and 21; in contrast, the relative amount of keratin no. 18 mRNA reached a peak shortly after birth and declined to very low levels in adult intestine. These results demonstrated marked changes in keratin expression and post-translational processing taking place at key stages of intestinal development. The appearance of keratin no. 21 in coincidence with the formation of an adult-type brush border and terminal web would be consistent with it having an important role in the organization of the intermediate filament network in the apical cytoplasm of the differentiated intestinal cells.

Journal ArticleDOI
TL;DR: It is concluded that the specific pattern of cell division led to differential cell density which, along with AM cell shape change, established the conditions necessary to achieve epidermal evagination.

Journal ArticleDOI
TL;DR: The current case suggests that the findings of glycocalyceal bodies and microvillous dense-core rootlets are not helpful in distinguishing between primary and metastatic lung adenocarcinomas.
Abstract: A 44-year-old woman with a long history of smoking presented with a single lung mass detected on routine chest radiographs. There were no other known primary tumors. Light microscopy showed a mucin-producing adenocarcinoma of bronchioloalveolar type. Furthermore, no gastrointestinal primary has been discovered 18 months after discovery of the lung tumor. Electron microscopy revealed that tumor cells had microvilli containing abundant microfilamentous, dense-core rootlets that showed long extensions into apical cytoplasm. The microvilli were capped by numerous glycocalyceal bodies. These findings are similar to the ultrastructural features previously described as being specific for gastrointestinal adenocarcinomas metastatic to lung. The current case, however, suggests that the findings of glycocalyceal bodies and microvillous dense-core rootlets are not helpful in distinguishing between primary and metastatic lung adenocarcinomas.

Journal ArticleDOI
TL;DR: The results show that at subsequent stages of development the lectin is expressed by cells of all three germ layers, including cells of the developing gut, coelomic pouches, and ectoderm, and by both primary and secondary mesenchyme cells.
Abstract: Echinonectin (EN) is a galactose-binding lectin present in eggs and embryos of the sea urchin Lytechinus variegatus. Recent studies have suggested that EN is a hyaline layer protein that may function as a substrate adhesion molecule (SAM) during development. We have used monoclonal and affinity-purified polyclonal antibodies that specifically recognize this protein to determine its spatial and temporal expression during embryogenesis. EN is stored in granules or vesicles in the unfertilized egg. After fertilization, these granules are rapidly redistributed to the apical cytoplasm of the zygote. Our results show that at subsequent stages of development the lectin is expressed by cells of all three germ layers, including cells of the developing gut, coelomic pouches, and ectoderm, and by both primary and secondary mesenchyme cells. In contrast to previous observations based solely upon light level immunofluorescent staining, immunoelectron microscopy demonstrates that EN is localized in intracellular, membrane-bounded vesicles. In epithelial cell types these vesicles have a highly polarized distribution and are found in the apical cortical cytoplasm. In mesenchyme cells the distribution of EN-containing vesicles is not obviously polarized. Steady-state levels of EN protein in the embryo remain almost constant from fertilization to the pluteus larva stage, Metabolic labeling studies show that synthesis of EN in L. variegatus begins immediately after fertilization and continues throughout embryogenesis. Monospecific antibodies raised against L. variegatus EN have also been used to determine whether this lectin is expressed in other echinoid species.

Journal ArticleDOI
TL;DR: In the present study E. spinosa infection did not produce overt clinical signs, but the patent period was not determined, and no villous atrophy in association with a large number of endogenous stages was observed.

Journal ArticleDOI
TL;DR: Investigation of the effects of diflubenzuron on the postmolt adult blue crab Callinectes sapidus offers morphologic evidence that the insect larvicide can interfere with crustacean chitin synthesis.
Abstract: Diflubenzuron is an insect larvicide that inhibits chitin synthesis. The effects of diflubenzuron were investigated on a nontarget organism, the postmolt adult blue crab Callinectes sapidus. Sections (explants) of the cuticle and epithelium were cut from the dorsal carapace of freshly molted blue crabs and maintained for 6 h in a buffered Ringer's solution containing diflubenzuron and 3H-glucosamine. Control sections were taken from the same animals and were maintained in a like fashion but without exposure to diflubenzuron. The sections were subsequently fixed, processed and examined by electron microscopy, or probed with a chitin oligosaccharide-binding lectin, or studied for 3H-glucosamine incorporation by autoradiography. Ultrastructurally, diflubenzuron-treated tissues showed coarse clumping of nuclear chromatin, dilation of the rough endoplasmic reticulum, and vesiculation of the apical cytoplasm of the cuticular epithelial cells. Decrease in nascent chitin in the treated tissues was demonstrated at the light microscopic level by scant binding of the lectin and minimal radiolabeling in the endocuticular region. The results offer morphologic evidence that diflubenzuron can interfere with crustacean chitin synthesis.

Journal ArticleDOI
TL;DR: It is demonstrated that the macula densa basement membrane and matrix material between extraglomerular mesangial cells is permeable to high molecular weight molecules and suggest unhindered diffusion of water and solutes within this area.
Abstract: To investigate the permeability properties of the basement membrane beneath macula densa cells and between extraglomerular mesangial cells, thick ascending limbs with attached glomeruli were dissected from rabbit kidney and incubated in a Ringers solution containing either horseradish peroxidase (HRP) (1 mg/ml; molecular weight approximately 40,000) or native or cationic ferritin (both at 5 mg/ml molecular weight approximately 450,000) for 5 and 20 min at room temperature. Tubules were processed for electron microscopy. At both time points, HRP reaction product fully permeated the matrix material between extraglomerular mesangial cells, the basement membrane underneath the macula densa, and also was occasionally located in intercellular spaces and intracellular vesicles within macula densa cells. Similar results were obtained with native and cationic ferritin. In separate experiments, thick ascending limbs with attached glomeruli were perfused for 20 min at room temperature with a Ringer solution containing HRP (1 mg/ml). HRP was found in tubulovesicular bodies within the apical cytoplasm of macula densa cells again indicating that these cells exhibit endocytotic activity. However, HRP did not gain access to intercellular spaces indicating that the apical junctional complex was impermeable to HRP. These results demonstrate that the macula densa basement membrane and matrix material between extraglomerular mesangial cells is permeable to high molecular weight molecules and suggest unhindered diffusion of water and solutes within this area.

Journal ArticleDOI
TL;DR: The most prominent changes to the biliary tree following infection by the parasite are the dilation of the bile ducts, alterations to their epithelial cells, and an increase in periductal fibrous tissue.
Abstract: Routine light microscopy and transmission and scanning electron microscopy were used to describe and compare the biliary tree of larval Lampetra lamottenii before and during infestation of the bile ducts with the nematode, Truttaedacnitis stelmioides. The most prominent changes to the biliary tree following infection by the parasite are the dilation of the bile ducts, alterations to their epithelial cells, and an increase in periductal fibrous tissue. In recently infected animals, the simple epithelium of dilated bile ducts often contains many mitotic figures. In long-term infestations, the epithelium is stratified or pseudostratified. Changes to the fine structure of the biliary epithelial cells include increase and/or dilation of the RER and SER, and increases in microfilaments, intermediate filaments, and microtubules. The abundance of dense bodies may reflect enhance reabsorption of biliary constituents, and their accumulation may ultimately result in cytolysis. There are increased mucous granules in the apical cytoplasm of biliary epithelial cells and an abundance of mucinous material within the bile duct lumen, and the basal lamina appears thickened. The changes to the liver of L. lamottenii following infection are discussed and compared to those reported in small mammals following bileduct ligation, in patients with extrahepatic biliary obstruction, and in parasitic infection of the biliary tree.© Willey-Liss, Inc.

Journal ArticleDOI
TL;DR: The fine structure of the main excretory duct epithelium of the male mouse submandibular glands was investigated by scanning and transmission electron microscopy and the granules may be derived from mitochondrial transformation and seem to be a special kind of secondary autolysosome.
Abstract: The fine structure of the main excretory duct epithelium of the male mouse submandibular glands was investigated by scanning and transmission electron microscopy. Three principal cell-types were observed: type I and II, and basal cells. This epithelium was characterized by the presence of intercellular canaliculi. Type-I cells were the most numerous. They had an abundance of mitochondria, well-developed Golgi apparatus, a few electron-lucent lipid-containing granules and poorly developed basal infoldings. These cells were also characterized by many glycogen granules throughout the cytoplasm and abundant smooth endoplasmic reticulum in the apical cytoplasm. Type-II cells were the second most numerous. Their most characteristic feature was the presence of abundant heterogeneous lipid-containing granules having acid phosphatase activity at the periphery. They were concentrated in the infra- and supra-nuclear cytoplasm. The granules may be derived from mitochondrial transformation and seem to be a special kind of secondary autolysosome. Type-II cells also contained abundant mitochondria throughout the cytoplasm, much smooth endoplasmic reticulum in the apical cytoplasm, a well developed Golgi apparatus adjacent to the heterogeneous lipid-containing granules and no basal infoldings. Basal cells were situated adjacent to the basal lamina. They had a large nucleus and the cytoplasm was filled with glycogen granules.

Journal ArticleDOI
01 Sep 1992-Placenta
TL;DR: The results are consistent with a secretory pathway including synthesis in the ER, processing by the Golgi complex, and exocytotic release into maternal blood in the intervillous space.

Journal Article
TL;DR: The extended aggregates of intracellular axonemal derivatives can be seen within the apical cytoplasm of ciliated cells of apparently healthy domestic pigs are more likely to be due to a failure of ciliary maturation than to a degradation of incorporated mature cilia.
Abstract: Extended aggregates of intracellular axonemal derivatives can be seen within the apical cytoplasm of ciliated cells of apparently healthy domestic pigs. Such alterations were observed in 15 out of 20 animals. Complete (9 + 2) or incomplete (8 + 2 - 5 + 2) intracellular axonemes were found which sometimes arose from mature, irregularly arranged kinetosomes. In addition, bundles of single microtubules and microtubular pairs were found. In previous investigations on the ciliated epithelium of different mammals, intracellular axonemes were investigated only under pathological or experimental conditions. Our findings indicate that these alterations also occur in healthy animals. The extended aggregates of intracellular axonemal derivatives are more likely to be due to a failure of ciliary maturation than to a degradation of incorporated mature cilia.

Journal ArticleDOI
TL;DR: The present findings suggested that negative or weakened staining at the basal and perinuclear portions of striated duct cells specifically reflects the primary or secondary cell damage produced by 60Coγ irradiation.
Abstract: Cytokeratin distribution in salivary glands was detected by use of polyclonal antikeratin antiserum (TK) and monoclonal antibodies (KL 1, RGE 53, and RPN 1164).The salivary glands of male rats received either 17. 82 Gy or 27.97Gy 60Coγ irradiation in a single exposure and were then compared immunohistochemically with those of normal rats.The following results were obtained.1. Polyclonal anti-keratin antiserum (TK), which reacts with 41-65 KD keratins, stained almost all ducts in normal glands.RPN 1164 (No.8 keratin) staining was negative in intercalated ducts of normal parotid and submandibular glands, but strongly positive in both striated and excretory ducts of these glands.Monoclonal antibody KL 1 (55-57 KD keratins) and RGE 53 (No.18 keratin) did not bind to any ductal or acinar epithelia.2. Only in the sublingual gland were acini positive for TK staining, possibly indicating myoepithelial cells.3. No effects of 60Coγ irradiation were apparent regarding keratin distribution in the intercalated duct.4. In striated duct cells, positive staining was lost in basal and perinuclear portions and restricted in apical cytoplasm by 60Coγ irradiation.5. Also, in the excretory duct, the basal side of the cells exhibited weakened staining following 60Coγ irradiation.6. Although the histology suggested that 60Coγ irradiation diminished in size of the granular convoluted tubule, no remarkable changes in keratin deposition were found.7. In striated ducts, changes in keratin distribution following 60Coγ irradiation were the most significant in the parotid and the least in the sublingual gland.Also this reaction depended upon the doses of 60Co used.The present findings suggested that negative or weakened staining at the basal and perinuclear portions of striated duct cells specifically reflects the primary or secondary cell damage produced by 60Coγ irradiation.Since the distribution of cytoskeletal proteins in the cytoplasm reflects certain pathological conditions, immunohistochemical detection of these proteins seem to have a diagnostic value with respect to cellular injury.

Journal Article
Mughal S1, Filipe Mi
TL;DR: The number of cases investigated is too small and a large series is required to clarify the significance of observations such as increased number of electron-dense bodies and vesicles in the apical cytoplasm and presence of atypical secretory cells.
Abstract: Ultrastructural changes that occurred in chronic active ulcerative colitis and Crohn's disease were investigated and compared to normal as well as to higher grades of dysplasia in adenomas and carcinomas. A greater number of immature absorptive cells, undifferentiated and intermediate cells were seen as compared to normal. One case of Crohn's and two cases of chronic ulcerative colitis including one with coexisting carcinoma showed increased number of vesicles and electron-dense bodies (EDB) in the absorptive cells and increased heterogeneity of mucin droplets in goblet cells and presence of atypical secretory cells (ASC). Higher grades of dysplasia characterised by large numbers of atypical secretory cells were not seen in the present series and provide no relationship between the atypical ultrastructural features and increased risk of malignancy. However, the number of cases investigated is too small and a large series is required to clarify the significance of observations such as increased number of electron-dense bodies and vesicles in the apical cytoplasm and presence of atypical secretory cells.

01 Jan 1992
TL;DR: The presence and localization of the microtubule mechanoenzymes cytoplasmic dynein and kinesin within rat testis and within germ cells and manchettes is consistent with current hypotheses concerning manchette function.
Abstract: To examine the possible role of microtubule-based transport in testicular function, we used immunofluorescent techniques to study the presence and localization of the microtubule mechanoenzymes cytoplasmic dynein (a slow-growing end-directed motor) and kinesin (a fast-growing end-directed motor) within rat testis. Cytoplasmic dynein immunofluorescence was observed in Sertoli cells during all stages of spermatogenesis, with a peak in apical cytoplasm during stages lX-XIV. Cytoplasmic dynein immunofluorescence was also localized within Sertoli cells to steps 9-14 (stages IX-XIV) germ cell-associated ectoplasmic specializations. In germ cells, cytoplasmic dynein immunofluorescence was observed in manchettes of steps 1S-17 (stages I-IV) spermatids, and small, hollow circular structures were seen in the cytoplasm of step 17 and step 18 spermatids during stages V and VI. Kinesin immunofluorescence was observed in manchettes of steps 10-18 spermatids (stages X-VI). The stage-dependent apical Sertoli cell cytoplasmic dynein immunofluorescence, in conjunction with the previously reported orientation of Sertoli cell microtubules (slow-growing ends toward the lumen) and peak secretion of androgen-binding protein and transferrin, is consistent with the hypothesis that cytoplasmic dynein is involved in Sertoli cell protein transport and secretion. Further, the localization of cytoplasmic dynein and kinesin to manchettes is consistent with current hypotheses concerning manchette function.

01 Jan 1992
TL;DR: In this article, the authors investigated the ultrastructural changes that occurred in chronic active ulcerative colitis and Crohn's disease compared to normal as well as to higher grades of dysplasia in adenomas and carcinomas.
Abstract: Summary. Ultrastructural changes that occurred in chronic active ulcerative colitis and Crohn's disease were investigated and compared to normal as well as to higher grades of dysplasia in adenomas and carcinomas. A greater number of immature absorptive cells, undifferentiated and intermediate cells were seen as compared to normal. One case of Crohn's and two cases of chronic ulcerative colitis including one with coexisting carcinoma showed increased number of vesicles and electron-dense bodies (EDB) in the absorptive cells and increased heterogeneity of mucin droplets in goblet cells and presence of atypical secretory cells (ASC). Higher grades of dysplasia characterised by large numbers of atypical secretory cells were not seen in the present series and provide no relationship between the atypical ultrastructural features and increased risk of malignancy. However, the number of cases investigated is too small and a large series is required to clarify the significance of observations such as increased number of electron-dense bodies and vesicles in the apical cytoplasm and presence of atypical secretory cells.