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1.
In structured tissues such as stratified squamous epithelium the age distribution of cycling cells in a particular part of the tissue is influenced by cell migration. Age distributions are derived for the proliferative cells of stratified squamous epithelium, dependent on the mode of migration; and the effect of using analytical methods which assume exponential or rectangular age distributions is discussed with particular reference to the analysis of stathmokinetic experiments. 相似文献
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Subcultivated rat lingual epithelium derived from primary expiants remains mitotically active, possesses an organellar complement similar to the parent tissue, and undergoes terminal differentiation. Successful growth of primary cultures requires an incubation temperature below 34 °C and the addition of dimethyl sulfoxide (DMSO) to the medium. The subcultures retain a stable morphological phenotype through a minimum of 15 passages. Cultures are long-lived and may be maintained for one year or more in any passage. 相似文献
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Immunohistochemical localization of thrombomodulin in the stratified epithelium of the rat is restricted to the keratinizing epidermis 总被引:2,自引:1,他引:1
The expression and function of thrombomodulin (TM), an endothelial cofactor protein for thrombin-mediated protein C activation,
in the epithelium are not fully characterized. This report describes the distribution and localization of TM in the various
types of epithelia in the rat by light and electron microscopic immunocytochemistry. TM showed a limited distribution and
was expressed by the keratinizing stratified epithelia of the skin, tongue, and esophagus, but was not present on the non-keratinizing
epithelia of the vagina, ureter, trachea, stomach, or gut. An identical pattern of TM expression was seen in mucocutaneous
junctions, transitional zones from a non-keratinizing stratified epithelium to a keratinizing epithelium at the edge of the
eyelid and in the anal canal. As the keratinization of the stratified epithelia proceeded, the staining intensity increased
in the transitional zones. Within the keratinizing stratified epithelia, TM staining was limited to the keratinocytes of the
spinous layer, the spinous cells. The subcellular localization of TM on the spinous cells was restricted to the plasma membrane
facing the intercellular spaces. TM was not detectable on the desmosomes or the two membranes making up the junction, presumably
the nexus. The functional significance of TM in keratinizing epithelia is discussed.
Accepted: 14 October 1999 相似文献
4.
The aim of our research was to identify Merkel cells in stratified squamous nonkeratinized epithelium of the human oesophagus. We chose the middle and lower part of the oesophagus. For identification of Merkel cells we used antibodies against simple-epithelial cytokeratines, especially anti CK 20, because it is providing the highest degree of specificity. Our investigation showed increased number of CK 20- positive Merkel cells in lower (distal) part of the oesophagus, approximately 60%. In the middle part of the oesophagus there were 30% of CK20-positive Merkel cells. 相似文献
5.
Lis GJ Litwin JA Furgal-Borzych A Zarzecka J Cichocki T 《Folia histochemica et cytobiologica / Polish Academy of Sciences, Polish Histochemical and Cytochemical Society》2007,45(3):229-232
RAM11 is a mouse monoclonal anti-rabbit macrophage antibody recognizing connective tissue and vascular (atheromatous tissue) macrophages. This study demonstrates a cross-reaction of RAM11 with an unknown antigen in rabbit normal epithelial cells. Formalin-fixed, paraffin sections of the New Zealand White rabbit normal skin, oral mucosa, esophagus, small intestine and lung were immunostained with RAM11 antibody followed by goat anti-mouse Cy-3-conjugated antiglobulin. RAM11-positive immunofluorescence was observed in basal layer cells of stratified squamous epithelia (skin, oral mucosa, esophagus). No RAM11 immunostaining was found in any cells of simple (intestinal, bronchial) epithelia. These findings show that basal cells of stratified squamous keratinized and non-keratinized epithelia of the rabbit express an antigenic epitope which is common with that of macrophage antigen recognized by RAM11 monoclonal antibody. 相似文献
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Throughout embryogenesis of the rat palate, from the early fetal to adult stages, a consistent subset of keratin proteins is synthesized in the epithelial lining cells. Although the relative abundance of particular keratins has been shown to vary with ongoing palatogenesis, the expression of finite keratins appears to be genetically predetermined. In order to preliminarily ascertain whether conformational changes accompanied intermediate filament 'maturation' from monomeric to polymeric keratin formation, we screened cytokeratins with polyclonal and monoclonal antibodies generated against adult-type keratins. Until epithelial stratification occurred on the 16th day of gestation, the keratin proteins were weakly immunoreactive. On the other hand, subsequent to epithelial thickening, adult-type immunoreactivity was initiated and progressed concomitantly with ongoing palatal development. These findings suggest that the cytokeratin intermediate filaments may progress through conformational 'maturation' during polymerization, and play a role in the eventual acquisition of the adult-type epithelial structure and function. 相似文献
8.
Although several types of modified stratified squamous epithelia are present in the adult mammal, most are presumably derived from similar embryonic progenitors. Mechanisms responsible for region-specific specialization are poorly understood. To correlate epithelial diversification with the expression of tissue-specific markers, we analyzed keratin protein composition in four representative types of rat squamous epithelia from early embryonic through adult phases of development. Keratin subsets synthesized in palatal mucosa were qualitatively similar, but differed dramatically in relative abundance. Tongue mucosa synthesized a different, but consistent subset of keratins which also changed quantitatively throughout morphogenesis. In contrast, different keratin genes were sequentially expressed during histogenesis of backskin and footpad epidermis. These data indicate that tissue-specific keratin biosynthesis is genetically predetermined early in embryogenesis. 相似文献
9.
Enhancement of vinculin synthesis by migrating stratified squamous epithelium 总被引:7,自引:4,他引:3 下载免费PDF全文
A 110-115-kD protein is present at levels 27-fold higher in migratory epithelium in the rat cornea than in stationary epithelium. This protein represents 2.7% of the total protein in migratory epithelium 6-h postabrasion wound and 0.1% of the total protein in stationary epithelium. Our findings demonstrate that this 110-115-kD protein is vinculin. In Western blots comparing proteins from migratory and control epithelium, antibody against vinculin cross-reacted with the 110-115-kD protein. Using immunoslot blots, vinculin was determined to be present at maximal levels 6 h postabrasion wound, at levels 22- and 8-fold higher than control at 18 and 48 h, respectively, returning to control levels 72 h postwounding. Vinculin was also localized by indirect immunohistochemistry in migrating corneal epithelium. 3-mm scrape wounds were allowed to heal in vivo for 20 h. In flat mounts of these whole wounded corneas, vinculin was localized as punctate spots in the leading edge of migrating epithelium. In cryostat sections, vinculin was localized as punctate spots along the basal cell membranes of the migrating sheet adjacent to the basement membrane and in patches between cells as well as diffusely throughout the cell. Only very diffuse localization with occasional punctate spots between adjacent superficial cells was present in stationary epithelium. The increased synthesis of vinculin during migration and the localization of vinculin at the leading edge of migratory epithelium suggest that vinculin may be involved in cell-cell and cell-substrate adhesion as the sheet of epithelium migrates to cover a wound. 相似文献
10.
Basal laminas are important sheets of specialized extracellular matrix that underlie and surround groups of cells, such as epithelia or endothelia, enabling the cells to orientate their basal/apical polarity and creating a microenvironment for them. Basal laminas can also individually encapsulate whole cells, such as muscle cells, thereby forming a microenvironment but not polarizing the enclosed cells. Other mesenchymal or stromal cells exist with no basal lamina. In the course of studying the bovine follicular basal lamina which underlies the multilayered epithelium of the ovarian follicle, we identified a developmentally regulated novel extracellular matrix (which we call focimatrix for focal intra-epithelial matrix). Focimatrix is composed of basal lamina-like material deposited as plaques or aggregates between the multilayers of the epithelial granulosa cells. The focimatrix does not encapsulate individual or groups of cells and therefore does not form a microenvironment for them. Focimatrix contains collagen type IV subunits alpha1 and alpha2 (but not alpha3-alpha6), and laminin chains alpha1, beta2 and gamma1 (but not alpha2 or beta1), and nidogen-1 and perlecan (but not versican). The amount of focimatrix increases with increasing follicular size, and its appearance precedes the expression by granulosa cells of the enzymes for steroid hormone synthesis, cholesterol side-chain cleavage cytochrome P450 (SCC) and 3beta-hydroxysteroid dehydrogenase (3beta-HSD), in the days preceding ovulation. The expression in granulosa cells of two components examined, nidogen-1 and perlecan, also increases substantially when follicles enlarge to a sufficient size capable of ovulating. Following ovulation the follicular basal lamina is degraded, and presumably focimatrix is too since it is not detected in corpora lutea that develop from the ovulating follicles. During this development the granulosa cells undergo an epithelial-mesenchymal transition (EMT) into luteal cells following ovulation, and substantially increase their expression of steroidogenic enzymes in the process. During EMT epithelial cells lose polarity. Since focimatrix exists on more than one side of the granulosa cells, we propose that it disrupts the polarity induced by the follicular basal lamina in the lead up to ovulation. Hence focimatrix maybe a key part of the follicular/luteal EMT. 相似文献
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Teruhiko Makino Mikiro Takaishi Masahiko Toyoda Masaaki Morohashi Nam-ho Huh 《The journal of histochemistry and cytochemistry》2003,51(4):485-492
We have recently identified a novel protein named hornerin, the structural features of which are most similar to those of profilaggrin, an essential protein for keratinization of epidermal tissues. In this study we examined the expression of hornerin compared with that of profilaggrin in various mouse tissues. Hornerin was expressed in the upper epidermis of newborn mouse skin, as was profilaggrin. In addition, both hornerin and profilaggrin were expressed in the tongue, esophagus, and forestomach. In all four tissues, immunostaining for hornerin and profilaggrin showed a granular pattern, and most of the signals for the two proteins were co-localized on keratohyalin granules. This was confirmed by double immunoelectron microscopy. Within keratohyalin granules, hornerin was detected more frequently in the periphery, whereas profilaggrin was equally distributed. A quantitative RT-PCR revealed that both genes were expressed at highest levels in the forestomach and at the next highest levels in skin. Profilaggrin mRNA was most abundant in the forestomach. In skin, the amount of hornerin mRNA was more than fourfold greater than the amount of profilaggrin mRNA. These results form the basis for a better understanding of possible overlapping and/or differential functions of hornerin and profilaggrin. 相似文献
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Colonization of the stratified squamous epithelium of the nonsecreting area of horse stomach by lactobacilli 总被引:2,自引:0,他引:2
Yuki N Shimazaki T Kushiro A Watanabe K Uchida K Yuyama T Morotomi M 《Applied and environmental microbiology》2000,66(11):5030-5034
Selective adhesion to only certain epithelia is particularly common among the bacterial members of the indigenous microflora of mammals. We have found that the stratified squamous epithelium of the nonsecreting area of horse stomach is colonized by gram-positive rods. The microscopic features of a dense layer of these bacteria on the epithelium were found to be similar to those reported in mice, rats, and swine. Adhering microorganisms were isolated and identified as Lactobacillus salivarius, L. crispatus, L. reuteri, and L. agilis by DNA-DNA hybridization and 16S rRNA gene sequencing techniques. These lactobacilli associated with the horse, except for L. reuteri, were found to adhere to horse epithelial cells in vitro but not to those of rats. A symbiotic relationship of these lactobacilli with the horse is suggested. 相似文献
16.
Tobey NA Argote CM Vanegas XC Barlow W Orlando RC 《American journal of physiology. Gastrointestinal and liver physiology》2007,293(1):G264-G270
The human esophagus is lined by stratified squamous epithelium (ESSE), and in some subjects with reflux disease the distal esophagus becomes lined by Barrett's specialized columnar epithelium (BSCE). ESSE and BSCE differ both histologically and functionally, the latter evident by differences in their in vivo transmural electrical potential difference (PD), ESSE averaging -15 mV and BSCE being greater than -25 mV. In this report we examine the basis for this difference in PD. This is done by mounting endoscopic biopsies of ESSE from 25 subjects without esophageal disease and BSCE from 19 with Barrett's esophagus in mini-Ussing chambers for electrical recordings basally and after bathing solution ion replacement. The results show that the PD of human ESSE reflects a low level of active ion transport (5.1 +/- 0.8 muA/cm(2)) combined with a high level of tissue (electrical) resistance (344 +/- 34 Omega.cm(2)) and that of BSCE reflects a high level of active transport (43.6 +/- 11.6 muA/cm(2)) combined with a low level of resistance (69 +/- 8 Omega.cm(2)). Furthermore, active transport in ESSE was principally due to sodium absorption whereas in BSCE it was equally divided between sodium absorption and anion (chloride/bicarbonate) secretion, the latter through an apical membrane, 4-acetamido4'-isothiocyano-2,2'-stilbenedisulfonic acid-sensitive anion channel. As an anion-secreting tissue with bicarbonate secretory capacity more than fivefold greater than ESSE, BSCE is better suited than ESSE for defense of the esophagus against reflux disease. 相似文献
17.
Si Chen Xinyu Liu Nanshuo Wang Qianshan Ding Xianghong Wang Xin Ge En Bo Xiaojun Yu Honggang Yu Chenjie Xu Linbo Liu 《Journal of biophotonics》2019,12(9)
Imaging nuclei of keratinocytes in the stratified squamous epithelium has been a subject of intense research since nucleus associated cellular atypia is the key criteria for the screening and diagnosis of epithelial cancers and their precursors. However, keratinocyte nuclei have been reported to be either low scattering or high scattering, so that these inconsistent reports might have led to misinterpretations of optical images, and more importantly, hindered the establishment of optical diagnostic criteria. We disclose that they are generally low scattering in the core using Micro‐optical coherence tomography (μOCT) of 1.28‐μm axial resolution in vivo; those previously reported “high scattering” or “bright” signals from nuclei are likely from the nucleocytoplasmic boundary, and the low‐scattering nuclear cores were missed possibly due to insufficient axial resolutions (~4μm). It is further demonstrated that the high scattering signals may be associated with flattening of nuclei and cytoplasmic glycogen accumulation, which are valuable cytologic hallmarks of cell maturation. 相似文献
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M C Holley 《Tissue & cell》1984,16(2):287-310
The basal apparatuses which anchor the gill cilia in Branchiostoma lanceolatum (Pallas) and the actinopharynx cilia in Calliactis parasitica (Couch) are similar in structure. In C. parasitica the pharynx epithelium and the basal apparatuses are flexible. The basal apparatuses, however, bend in only one direction. This mechanism may permit epithelial flexibility whilst maintaining a similar basal orientation between cilia. In B. lanceolatum the ciliated gill epithelia are mechanically stable but the epithelial surfaces are curved. The basal apparatuses may correct for this curvature, with short rootlets between the distal centrioles (basal bodies) and the cell membranes, so that their cilia also share a common orientation. A common basal orientation between cilia is important for their coordination. The degree of coordination depends upon the function of the cilia; water-propelling cilia are more precisely coordinated than mucus-propelling cilia. Much of the structural diversity of ciliary basal apparatuses in Metazoa may be due to variation in the demands of anchoring functionally different cilia to epithelia which have different structural and mechanical properties. 相似文献
20.
Yoshida S Yasuda M Miyashita H Ogawa Y Yoshida T Matsuzaki Y Tsubota K Okano H Shimmura S 《PloS one》2011,6(12):e28856