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PubMed1966

The potential and short-circuit current across isolated rumen epithelium of the sheep.

1. A technique is described for working with isolated sheets of rumen epithelium. Epithelium was obtained at operations for rumen fistulation or in acute experiments and was rapidly mounted between two cone-shaped chambers each of which held 40 ml. of bathing fluid. The fluids were gassed with 95% O2/5% CO2 and 20 cm2 of epithelium was exposed to the fluids. 2. Electrical measurements were made of (a) the potential generated across the epithelium, (b) the short-circuit current which flowed and (c) the resistance of the epithelium. 3. The results are grouped according to the composition of the sheep Ringer solution used to bathe the epithelium. The most stable preparation was obtained when the solutions contained 5 mM each of glucose, acetate, propionate and butyrate as well as bicarbonate and phosphate buffers. 4. In Cl- media, the average initial p.d., short-circuit current (s.-c.c.) and resistance were 9.3 mV, 11.6 microA/cm2 and 1156 omega x cm2 respectively. Higher values of 17.6 mV, 17.3 microA/cm2 and 1501omega x cm2 were recorded in SO4(2-) media. In both media, the s.-c.c. declined at approximately 1.5 microA/cm2. hr and preparations were suitable for study over periods from 4 to 6 hr. 5. When the concentration of potassium was varied on either side of the epithelium at constant [Na+], the potential showed a linear relation with log [K+] for both sides of the epithelium. 6. Changing the sodium concentrations at constant [K+] on either side of the epithelium caused negligible alterations in the potential. 7. Exclusion of sodium from the media bathing both sides of the epithelium abolished the potential and s.-c.c. 8. The addition of ouabain to the blood side of the preparation abolished the potential and s.-c.c. whereas on the rumen side these parameters were unaffected.

Animals↗
PubMed1988

Removal of the epithelium potentiates acetylcholine in depolarizing canine bronchial smooth muscle.

Experiments were designed to determine whether the airway epithelium affects the membrane potential of the underlying smooth muscle. The effect of epithelium removal (by gentle rubbing) on the responsiveness of isolated canine bronchi was studied. Simultaneous recordings of mechanical and electrical activity were made in paired circumferential strips (with and without epithelium) of third-order bronchi. Changes in tension were recorded with a force transducer, and changes in membrane potential were measured with a microelectrode. The cell membrane potential and resting tension of the bronchial smooth muscle were stable over a 150-min period and were not affected by removal of the epithelium. In the presence of antagonists at muscarinic and adrenergic receptors, the resting tension and membrane potential were comparable in preparations with and without epithelium. By contrast, the anticholinesterase, echothiophate, caused depolarization in bronchi without epithelium. Exposure to high potassium induced similar levels of depolarization and contraction in tissues with and without epithelium. No significant differences in threshold for depolarization or for mechanical activation in the membrane potential-tension relationship were noted in the presence or absence of epithelium. In the presence of echothiophate, removal of the epithelium augmented the contraction of the bronchi to acetylcholine; the depolarization of the cell membrane induced by the cholinergic transmitter was significantly larger than in control tissues, even when matched contractions were compared. These observations indicate that the respiratory epithelium generates an inhibitory substance that dampens depolarization and contraction of bronchial smooth muscle caused by acetylcholine.

Acetylcholine↗
PubMed1989

Epithelium removal alters responsiveness of guinea pig trachea to substance P.

Removal of epithelium from mammalian tracheae has been shown to enhance responsiveness to a variety of contractile and relaxant agents. One of the most dramatic shifts reported has been for guinea pig tracheal tissue denuded of epithelium and treated with substance P. We investigated whether this shift in responsiveness was because of 1) removal of an epithelium-associated enzyme, neutral endopeptidase, which degrades substance P and 2) loss of an epithelium-derived noncyclooxygenase relaxant factor. Using a muscle bath preparation we performed concentration-response curves with substance P and acetylcholine on indomethacin-treated tissues with and without intact epithelium and with and without pretreatment with the neutral endopeptidase inhibitor, phosphoramidon. Epithelium removal potentiated the mean agonist concentration calculated to causes 30% of the maximal contractile response by 148-fold for substance P and by 7-fold for acetylcholine. Phosphoramidon potentiated the contractile response to substance P, but not to acetylcholine, by both the epithelium-intact and denuded tissues (P less than 0.05). However, the degree of enhancement by phosphoramidon was much greater in the intact tissues. With phosphoramidon treatment, therefore, the difference in responsiveness to substance P between the intact and denuded tissues was reduced from 148-fold to 18-fold. This effect of phosphoramidon suggests that the hyperresponsiveness to substance P of epithelium-denuded airway tissue is largely because of removal of neutral endopeptidase. Because all tissues were treated with indomethacin, the leftward shifts in substance P and in acetylcholine responsiveness induced by epithelium removal further suggest that an epithelium-derived noncyclooxygenase factor other than neutral endopeptidase also modulates the contractile response to substance P and to acetylcholine.

Acetylcholine↗
PubMed2004

Sonic hedgehog expression and role in healing corneal epithelium.

PURPOSE: To examine the expression pattern and roles of Sonic hedgehog (Shh) in healing corneal epithelium. METHODS: Immunofluorescent staining and Western blot analysis were used to detect Shh, patched 1 (Ptc 1) receptors, and Gli transcription factors in corneal epithelium of Wistar rats (n = 44) at various intervals after an epithelial defect. Effects of exogenous Shh on cell proliferation and cyclin D1 expression were determined in healing corneal epithelium of organ-cultured mouse eyes. RESULTS: Uninjured rat corneal epithelium was not labeled by anti-Shh antibody, but weakly positive for Ptc 1. Basal cells of limbal and conjunctival epithelia were labeled by antibodies against Shh and Ptc 1. Shh protein was transiently upregulated in limbal epithelium in 2 hours and was also transiently expressed in the migrating corneal epithelium with its peak at 12 hours postdebridement. Such upregulation of Shh expression was associated with a transient nuclear translocation of Gli-3 without lifting the suppression of cell proliferation in migrating epithelium postdebridement in vivo. However, an addition of Shh protein to culture medium resulted in nuclear accumulation of cyclin D1 and marked acceleration of epithelial cell proliferation in migrating corneal epithelium of an organ-cultured mouse eye. CONCLUSIONS: Corneal epithelial debridement causes a transient upregulation of Shh expression and activation of Shh/Gli-3 signaling cascade in healing corneal and limbal epithelia. Although exogenous Shh promotes epithelial cell proliferation in corneal organ culture, its expression in migrating epithelium in vivo does not counteract the suppression of cell proliferation at the early healing phase of epithelium debridement.

Animals↗
PubMed2004

Expression and function of tight junctions in the crypt epithelium of human palatine tonsils.

The human palatine tonsils have surface and crypt stratified epithelium and may be initiated via the epithelium to mount immune responses to various presenting antigens. Here we investigated the expression and function of tight junctions in the epithelium of human palatine tonsils from patients with tonsillar hypertrophy or recurrent tonsillitis. Occludin, ZO-1, JAM-1, and claudin-1, -3, -4, -7, -8, and -14 mRNAs were detected in tonsillar hypertrophy. Occludin and claudin-14 were expressed in the uppermost layer of the tonsil surface epithelium, whereas ZO-1, JAM-1, and claudin-1, -4, and -7 were found throughout the epithelium. In the crypt epithelium, claudin-4 was preferentially expressed in the upper layers. In freeze-fracture replicas, short fragments of continuous tight junction strands were observed but never formed networks. In the crypt epithelium of recurrent tonsillitis, the tracer was leaked from the surface regions where occludin and claudin-4 disappeared. Occludin, ZO-1, JAM-1, and claudin-1, -3, -4, and -14, but not claudin-7, mRNAs were decreased in recurrent tonsillitis compared with those of tonsillar hypertrophy. These studies suggest unique expression of tight junctions in human palatine tonsillar epithelium, and the crypt epithelium may possess an epithelial barrier different from that of the surface epithelium.

Adolescent↗
PubMed1998

A three-dimensional study of human fetal endocervix with special reference to its epithelium.

The development of human fetal cervix has been systematically studied by SEM, obtaining a detailed map of its fine structure, particularly concerning the differentiation and maturation of the endocervical epithelium, including its "eversion" and "squamous metaplasia", normally occurring in postnatal life, but not yet observed in detail by electron microscopy in the fetus. Cervices from spontaneous abortion at 12, 15, 18, 20, 21 and 22 weeks and from intrauterine fetal death (hydrocephalus) at 31 weeks of development have been examined. At 12-15 weeks, as the canalization of the cervix proceeded, the endocervical epithelium consisted of high polyhedral cells, with regularly flattened or concave apices exhibiting scarce microvilli and often single primary cilia. Some narrow intercellular infoldings probably corresponded to primordial tubular glands. At the 18th week the epithelium was made up of a mosaic of flat or slightly raised polygonal cells, whose apical surface showed thin microplicae. At the 20th week a pseudostratified epithelium with many apically convex cells lined the cervical canal and the tubular glands. At 21 and 22 weeks "plicae palmatae" developed, covered by cells, often showing a smooth central area surrounded by microvilli, provided with a primary cilium and swollen by secretory material. This also formed rounded masses on the epithelium. In the lower part of the endocervix some very elongated cells showed short microplicae resulting from fusion of microvilli. At the 31st week secretion increased and its products spreading from the bottom of the glands contacted isolated ciliated cells at their openings and diffusely covered the surface epithelium. Most of the ectocervix exhibited squamous elements, with well-developed labyrinthine microplicae. These cells could overlap each other and also desquamate. The zone of the portio vaginalis around the os of the cervical canal appeared infolded and hypertrophic. Here, an indented squamo-columnar junction between the ectocervical and endocervical epithelium, caused by tongue-like prolongations of squamous epithelium directed toward the endocervix, was found. Their tips consisted of elongated cells, rich only in short microvilli. Our data indicate that the features of the microvillous cells are an expression of a hormone-dependent differentiative process. Thus, their secretion might be stimulated by progesterone. Similarly microplicae on the ectocervical epithelium (a sign of squamous maturation) might be promoted by estrogens. Furthermore, two aspects were significative: 1) the finding--in an early phase only (18th week)--of endocervically-located squamous cells, although devoid of microplicae; and 2) the occurrence--in the latest phase (31st week)--of an indented squamo-columnar junction on the surface of the portio. These features are in agreement with the caudal shift of the squamo-columnar junction near the uterine cavity to the ectocervix after cervico-vaginal demarcation; the squamous metaplasia of this everted endocervical epithelium has been reported by some authors. It is likely that these processes, occurring in fetal life as well as in pregnant women, are related to a common hormonal background, arising from the mother to her fetus.

Cervix Uteri↗
PubMed2002

Connexin 43 expression and proliferation of human limbal epithelium on intact and denuded amniotic membrane.

PURPOSE: Stem cell (SC)-containing limbal basal epithelium and transient amplifying cell (TAC)-containing corneal basal epithelium lie on different mesenchymal matrices. The gap junction protein connexin 43 (Cx43) is absent in the limbal basal epithelium but is present in the corneal basal epithelium, suggesting that the expression of Cx43 denotes SC differentiation into TACs. Amniotic membrane (AM) can expand limbal epithelial progenitor cells in vivo and in culture for subsequent corneal surface reconstruction. In this study, the modulation of Cx43 expression, gap junction intercellular communication (GJIC), and proliferative activity of ex vivo expanded human limbal epithelial (HLE) cells on intact and epithelially denuded AM was investigated. METHODS: HLE cells were expanded on intact (i.e., remaining devitalized amniotic epithelium) or epithelially denuded AM (EDTA-treated). Cx43 expression and 24-hour 5-bromo-2'-deoxyuridine-5'monophosphate (BrdU) labeling index (percentage) were determined by double immunostaining. GJIC was investigated by a scrape-loading dye transfer assay. In a subset of cultures Cx43 and K3 keratin as well as BrdU-retaining nuclei were analyzed in the stratified epithelium obtained 5 days after subcutaneous transplantation in NIH bg-nu-xidBR mice of AM cultures continuously labeled with BrdU for 7 days. RESULTS: The outgrowth rate, overall, was significantly higher on EDTA-treated AM than on intact AM (P < 0.05). Cx43 was expressed in 12.4% +/- 14.5% (n = 5) on intact and 57.5% +/- 18.2% (n = 5) on EDTA-treated AM (P < 0.05). The BrdU labeling index was 2.4% +/- 0.9% (n = 5) for the intact AM group, which was significantly less than 22.5% +/- 8.2% (n = 5) for EDTA-treated AM (P < 0.05). BrdU-labeled cells did not express Cx43. The dye transfer assay revealed reduced GJIC on both AM-cultured groups compared with the control culture on plastic (P < 0.002). GJIC on intact AM (17%) was reduced compared with that on EDTA-treated AM (27%; P = 0.42). After xenotransplantation, the basal layer of the stratified epithelium was Cx43 and K3 keratin negative and retained BrdU on intact AM, resembling characteristics of the limbal basal epithelium in vivo. In contrast, that of EDTA-treated AM was Cx43 and K3 keratin positive without BrdU retention, resembling characteristics of the corneal epithelium in vivo. CONCLUSION: These data indicate that denudation of the devitalized amniotic epithelium to expose its basement membrane might be a microenvironmental cue to promote TAC differentiation. The model system described herein is ideal for future exploration of the exact mechanistic operation in the microenvironmental niche that maintains the "stemness" of limbal SCs as well as in the signal that promotes corneal TAC differentiation.

Amnion↗
PubMedDate not supplied

[Ultrastructure of epithelium and ciliary receptors in the parasitic turbellarian Urastoma cyprinae (Turbellaria, "Prolecithophora") and position of the species within Platyhelminthes].

Ultrastructure of the epithelium of adult and juvenile Urastoma cyprinae has been studied. The epithelium of both adult and juvenile worms is cellular, ciliated and bears numerous microvilli. The cytoplasm is rich in large, numerous epitheliosomes of two types--electron-dense and with fibrillated content (fig. 1, a, [symbol: see text]; 2, a-[symbol: see text]). Besides large secrete granules small membrane-bounded vesicles were observed (fig. 2, a-[symbol: see text]). In juvenile worms the dense epitheliosomes are less abundant and the fibrillated content in the second type of granules has a different structure: the fibrils are very thin and more densely packed forming the structures of the less electron density (fig. 3, a, [symbol: see text], [symbol: see text] 1). The membrane-bounded vesicles in the epithelium of juvenile worms were not observed. All types of secrete are ejected by exocytosis (fig. 2, [symbol: see text]; 3, [symbol: see text], [symbol: see text]). The ultrastructure of the epithelium in juvenile U. cyprinae is strongly similar to that in parasitic turbellarian Kronborgia, especially to the epithelium in a male and a larva. The basal lamina consists of tree layers and forms numerous deep infoldings into the epithelium (fig. 1, a; 2, a; 3, a, [symbol: see text], [symbol: see text]). The basement membrane projects deep and numerous invaginations into the epithelium which may almost reach the apical membrane (fig. 1, a; 2, a, [symbol: see text], [symbol: see text]; 3, [symbol: see text]). Mitochondria are large and situated mainly near the projections of the basement membrane (fig. 2, [symbol: see text]-[symbol: see text]; 3, [symbol: see text]). Such ultrastructure implies an intensive process of the transmembrane transfer of the dissolved organic substances from the sea water. The same structures were found in the epithelium of Kronborgia. Uptake of organic compounds through the epithelium in the common ancestors of Urastoma and Kronborgia could be the preadaptation to the endoparasitic mode of life in Fecampiida. The differencies in ultrastructure of epithelium in U. cyprinae from the White Sea and from Mediterranean Sea (Noury-Sraïri e. a., 1990) may be explained by the differences in the method of fixation or by the parasitizing the another host--the mollusk Mytilus galloprovincialis. The ciliary receptors of five types were revealed in U. cyprinae (fig. 3, e, [symbol: see text]; 4; 5; 6). They differ in the shape and length of the ciliary rootlets and in the content of the nerve processes. All receptors lack of the real collars typical for the receptors of Neodermata. Urastoma is most close to the Neodermata amond parasitic turbellarians studied thus far, and the absence of collars in receptors of this species testifies that the collars are the veritable synapomorphy of the Neodermata. The diversity in the ultrastructure and possible functions of receptors correspond to the complicated adaptations of this species. The modern molecular data as well as the ultrastructural evidence attest that parasitic turbellarians of the genera Urastoma, Genostoma and Ichthyophaga are relatives and cannot be included in any turbellarian order known. Therefore Urastoma, Genostoma and Ichthyophaga have been erected in the separate order Urastomida ord. nov. The diagnosis of the new order is given.

Animals↗
PubMed2004

[Expression of PTKs CDK4 and p15 in the middle ear cholesteatomatous epithelium].

OBJECTIVE: To explore the cells proliferation and its molecular regulating mechanisms of cholesteatomatous epithelium from the aspect of protein tyrosine kinases (PTKs) signal transduction and cell cycle control. METHOD: The expressions of phosphated PTKs, CDK4 and p15 were investigated by immunohistochemical S-P method and computer image analysis in 30 specimens of the middle ear cholesteatomatous epithelium and 19 specimens of external auditory canal epithelium from patients with chronic otitis media with cholesteatoma. The expressive results of phosphated PTKs, CDK4 and p15 were determined in same epithelium of different slices of same specimen. Statistical analysis was performed by the connection with degree of subepidermal inflammatory cell infiltration and degree of bone destruction. RESULT: The expression of phosphated PTKs was primarily staining in cell membrane, and the staining of CDK4 were located in the nuclei as well as the cytoplasm of cells, and the staining of nuclei was primary, but the staining of p15 was expressed only in the nuclei of cell. The expressions of phosphated PTKs, CDK4 and p15 in epithelium were clearly increased compared with that of external auditory canal epithelium (P < 0.01). The expression of phosphated PTKs and CDK4 tended to be strong in the epithelium with subepidermal inflammatory, and the expression of CDK4 tended to be strong in the epithelium with high level expression of phosphated PTKs (P < 0.01). The expressions of above investigated indexes were not significantly different under the different degree of bone destruction (P > 0.05). CONCLUSION: The cholesteatomatous epithelium have a hyperproliferation ability, and also show a mechanism of inhibiting proliferation ability. The microenvironment with inflammatory cell infiltration has a tendency to greatly affect proliferation ability of cholesteatomatous epithelium.

Adult↗
PubMed1990

[A pathological and histochemical study of capsules of impacted teeth with special reference to keratin immunohistochemistry in the lining epithelium].

The purpose of this study was to examine and understand the nature of capsules consisted of fifty cases of unerupted wisdom teeth using radiological, pathological and immunohistochemical methods. Radiologically, the pericoronal space was measured with slide caliper and divided into three groups (-0.9 mm, 1.0-1.9 mm, 2.0mm). Pathologically, all specimens were examined by the routine paraffin method and were stained with hematoxylin.eosin and PAS-alcian blue pH 2.5 stainings. Immunohistochemically, PAP (peroxidase-antiperoxidase) method using various keratin antibodies, such as, anti-keratin K 528 (40-68 KD), anti-cytokeratin PKK 1 (40, 45, 52.5 KD), anti-cytokeratin PKK 2 (40, 46, 48, 54 KD), anti-keratin A 575 (56, 64 KD) and anti-cytokeratin high molecular weight (68 KD), and other various antibodies of anti-EMA, anti-IgA and anti-SC was used in order to study the nature of the epithelium of capsule of impacted teeth. The following results were obtained; 1. Radiologically, the width of the capsules was 1.6 mm in the average. Histopathologically, the inner surface of the capsule was covered with two types of epithelium which were composed of non-typical epithelium with cuboidal (basal layer) and columnar (superficial layer) cells, and typical stratified squamous epithelium. The epithelium lining was observed in 74% of all cases. Among the cases, cyst like structure was more often seen in the cases with typical squamous epithelial lining and with pericoronal space more than 1.0 mm width. 2. In the connective tissue's findings of capsules of impacted teeth, fibrosis was found in almost all the cases. Inflammatory and myxomatous changes were recognized in ca. half cases. Epithelial rest and calcification with dystrophy and epithelial product were observed in about one third of the cases. The epithelial proliferation in the capsule was also rarely seen in the specimens. 3. Immunohistochemically, keratins of 56 KD and 64 KD were identified in the superficial layer of non-typical epithelium and basal, intermediate and superficial layers of the typical squamous epithelium of the capsules of imparted teeth. Keratin of 68 KD was only observed in superficial layer of squamous epithelium. 4. Epithelial membrane antigen was positive in the intermediate and superficial layers of typical squamous cell epithelium. However, it was not seen in the non-typical epithelium of capsule of impacted teeth. 5. Immunoglobulin A and secretory component were negative in the epithelia of capsules.

Epithelium↗
PubMed1993

Pharmacologic modulation of the influence of the epithelium on immunologic- and nonimmunologic-induced histamine release and contraction in guinea pig superfused tracheal strips.

The influence of the epithelium on contractions and histamine release evoked by ovalbumin and d-tubocurarine has been examined in guinea pig superfused tracheal strips under several experimental conditions. Without drug pretreatment, removal of the epithelium resulted in larger (P < .05) total histamine released by ovalbumin, 10(-4) to 10(-1) mg/ml, and by d-tubocurarine, 3 x 10(-3) M. In the presence of indomethacin, 5 x 10(-6) M, epithelium removal resulted in elevated histamine release only at smaller ovalbumin concentrations, 10(-4) and 10(-3) mg/ml. Indomethacin did not change the influence of the epithelium on histamine release by d-tubocurarine. Indomethacin treatment abolished the influence of the epithelium on ovalbumin-induced tracheal contraction. With indomethacin, larger (P < .05) histamine release was seen with ovalbumin, 10(-1) and 1 mg/ml, when the epithelium was intact. The larger histamine release in response to ovalbumin, 10(-1) mg/ml, in the presence of the epithelium was unaltered by pyrilamine, 10(-6) M, cimetidine, 10(-4) M, and thioperamide, 10(-6) M, to block histamine H1, H2 and H3 receptors, respectively. Therefore, histamine released by ovalbumin does not stimulate histamine release through an action on these receptors when the epithelium is intact. In the presence, but not in the absence, of the epithelium, A64077, 10(-5) M, and ICI198615, 10(-8) and 10(-6) M, inhibitors of 5-lipoxygenase and LTD4/E4 receptors, respectively, inhibited histamine release by ovalbumin, 10(-1) mg/ml. Histamine release by ovalbumin, 10(-4) mg/ml, and d-tubocurarine, 3 x 10(-3) M, studied with or without epithelium was not altered by A64077 or ICI198615.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2003

Globose basal cells are required for reconstitution of olfactory epithelium after methyl bromide lesion.

Despite a remarkable regenerative capacity, recovery of the mammalian olfactory epithelium can fail in severely injured areas, which subsequently reconstitute as aneuronal respiratory epithelium (metaplasia). We contrasted the cellular response of areas of the rat epithelium that recover as olfactory after methyl bromide lesion with those undergoing respiratory metaplasia in order to identify stem cells that restore lesioned epithelium as olfactory. Ventral olfactory epithelium is at particular risk for metaplasia after lesion and patches of it are rendered acellular by methyl bromide exposure. In contrast, globose basal cells (GBCs, marked by staining with GBC-2) are preserved in surrounding ventral areas and uniformly throughout dorsal epithelium, which consistently and completely recovers as olfactory after lesion. Over the next few days, neurons reappear, but only in those areas in which GBCs are preserved and multiply. In contrast, parts of the epithelium in which GBCs are destroyed are repopulated in part by Bowman's gland cells, which pile up above the basal lamina. Electron microscopy confirms the reciprocity between gland cells and globose basal cells. By 14 days after lesion, the areas that are undergoing metaplasia are repopulated by typical respiratory epithelial cells. As horizontal basal cells are eliminated from all parts of the ventral epithelium, the data suggest that GBC-2(+) cells are ultimately responsible for regenerating olfactory neuroepithelium. In contrast, GLA-13(+) cells may give rise to respiratory metaplastic epithelium where GBCs are eliminated. Thus, we support the idea that a subpopulation of GBCs is the neural stem cell of the olfactory epithelium.

Administration, Inhalation↗
PubMed2003

Aberrant expression of CDX2 in Barrett's epithelium and inflammatory esophageal mucosa.

BACKGROUND: There have been no detailed reports directly comparing the expression of CDX1 with that of CDX2 in the inflammatory esophageal mucosa and Barrett's epithelium. The present study was designed to examine the expression of CDX 1/2 in inflammatory esophageal mucosa with or without Barrett's epithelium. METHODS: The expression of CDX1/2 genes was analyzed using the reverse transcriptase-polymerase chain reaction (RT-PCR) in 34 human esophageal biopsy specimens, and CDX2 expression was also evaluated immunohistochemically, using anti-human CDX2 monoclonal antibody. The biopsy specimens for RNA extraction were taken endoscopically from esophageal mucosa with mucosal break due to gastroesophageal reflux disease (GERD), Barrett's epithelium, and normal epithelium. The expressions of mucin markers (MUC2) and intestine-specific genes (sucrase-isomal-tase, human defensin-5, alkaline phosphatase) were also comparatively analyzed. RESULTS: CDX1/2 expression was not found in the normal esophageal mucosa. The prevalence of CDX1/2 mRNA expression was significantly higher in the mucosa with Barrett's epithelium than in the mucosa without Barrett's epithelium. It is noteworthy, however, that the CDX2 mRNA expression was initiated at the stage of esophagitis, when neither CDX1 nor intestine-specific genes had emerged yet. In contrast to CDX2, CDX1 was expressed only in Barrett's epithelium. Immunohistochemical study demonstrated strong and extensive nuclear immunoreactivity for CDX2 in Barrett's epithelium. Furthermore, fine granular cytoplasmic staining was also observed in the cytoplasm in Barrett's epithelium, as well as in inflammatory esophageal mucosa. CONCLUSIONS: We report here, for the first time, that CDX2 is expressed in patients with Barrett's epithelium and inflammatory esophageal mucosa. These findings imply that the expression of CDX2 may be an early event leading to the development of Barrett's esophagus.

Adult↗
PubMed1992

Immunohistochemical study of nerve fibres with substance P- or calcitonin gene-related peptide-like immunoreactivity in the junctional epithelium of developing rats.

The beginning of innervation in the junctional epithelium of maxillary first molars was examined in gingival tissues from 19 to 32-day-old rats. Substance P- or calcitonin gene-related peptide (CGRP)-like immunoreactivity was demonstrated by the avidin-biotin peroxidase complex method. In 19-day-old rats, nerve fibres with substance P- or CGRP-like immunoreactivity were seen in the connective tissue and oral epithelium, but not in the reduced enamel epithelium, which would be transformed into the junctional epithelium. In 21-day-old rats, the fibres with substance P- or CGRP-like immunoreactivity formed a plexus in the oral sulcular epithelium and thin varicose fibres were seen for the first time entering the adjacent reduced enamel epithelium. These fibres also penetrated the middle portion of the reduced enamel epithelium, but did not reach the cuboidal reduced ameloblasts. More nerve fibres had CGRP-like immunoreactivity than substance P-like immunoreactivity. In 23-day-old rats, many fibres with both immunoreactivities were seen in the basal layers of the junctional epithelium, but only a few were seen in its superficial layers. In 28-32-day-old rats, numerous fibres with both immunoreactivities were distributed in the whole junctional epithelium and showed a similar pattern of innervation. For all immunoreactive fibres, the density in the middle portion in the junctional epithelium was the highest. The nerve plexus was formed in the basal layers and some fibres with a varicose appearance were found in the superficial layers.

Animals↗
PubMed1997

Estrogen-induced epithelial proliferation and cornification are uncoupled in sinus vaginal epithelium associated with uterine stroma.

Epithelium from the urogenital sinus-derived portion of the newborn mouse vagina when grown in association with uterine mesenchyme forms a "vaginal" stratified squamous non-cornified epithelium. However, the epithelium of these tissue recombinants composed of sinus vaginal epithelium plus uterine mesenchyme does not undergo the fluctuations in cytodifferentiation normally seen in vaginal epithelium during the estrous cycle (e.g., cornification and mucification). In this report we show that sinus vaginal epithelium in association with uterine mesenchyme proliferated in response to estradiol but failed to cornify in response to diethylstilbestrol (DES), even though both the epithelium and the stroma had estrogen receptors. However, if sinus vaginal epithelium that had been grown in combination with uterine mesenchyme was re-isolated from the tissue recombinant and recombined with fresh vaginal mesenchyme, the epithelium cornified in response to DES. These results indicate that the proliferative and the cytodifferentiation response to estrogen could be uncoupled and that sinus vaginal epithelium required vaginal stroma to cornify in response to DES.

Animals↗
PubMed2006

Establishment of a cultivated human conjunctival epithelium as an alternative tissue source for autologous corneal epithelial transplantation.

PURPOSE: The corneal epithelium is essential for maintaining corneal transparency, and efforts have been made to develop improved techniques for corneal epithelial transplantation in patients with total limbal failure. We evaluated the suitability of transplanted cultivated human conjunctival epithelium (HCjE) as a corneal epithelium replacement in rabbits with total corneal and limbal deficiency. METHODS: HCjE cells, cultivated on human amniotic membrane (AM) to confluence and exposed to an air-liquid interface (air-lifted), were transplanted onto denuded rabbit corneas and monitored for 2 weeks. The cultivated HCjE sheet and the engrafted epithelium were analyzed by immunohistochemistry and transmission electron microscopy (TEM). RESULTS: The transplanted HCjE remained transparent, smooth, and without epithelial defects during the follow-up period. Both the cultivated HCjE cells and the engrafted epithelium manifested five to six layers of stratified squamous epithelium similar in morphology to normal corneal epithelium. The basal cells expressed the putative stem cell markers (ABCG2 and P63) and hemidesmosome and desmosome component proteins. The cytokeratins (CK4, CK13, CK3, and CK12) and MUC4 were found in the engrafted epithelium. However, MUC5AC was not expressed. The results indicate that HCjE cultivated on AM has the potential to be used as an alternative corneal epithelium. CONCLUSIONS: The transplantation of cultivated HCjE sheets is a promising technique for the treatment of eyes with limbal failure.

ATP Binding Cassette Transporter, Subfamily G, Mem↗
PubMed1996

K-ras point mutations in cancerous and noncancerous biliary epithelium in patients with pancreaticobiliary maljunction.

BACKGROUND: Pancreaticobiliary maljunction (PBM), an anomalous union of the pancreatic duct with the common bile duct, has frequently been shown to be associated with biliary carcinoma. However, the mechanism of carcinogenesis is unknown. METHODS: Mutations of the K-ras oncogene were examined in cancerous and noncancerous biliary tract epithelium of 20 patients with PBM by an extraction of DNA from surgically resected histologic specimens. DNA was analyzed by a polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) method and direct sequencing. RESULTS: An abnormally mobilized DNA band was detected not only in cancerous epithelium but also in hyperplastic, metaplastic, and inflammatory epithelium of the gallbladder and/or common bile duct in patients with PBM. Among the biliary epithelium of patients with PBM, point mutation of K-ras oncogenes were detected in 4 of 5 (80%) cancerous epithelium, 7 of 12 (58%) hyperplastic and metaplastic epithelium, and 8 of 18 (44%) inflammatory epithelium, whereas no point mutation of the K-ras oncogene was detected in the gallbladder epithelium in 3 control patients without PBM. Direct sequence analysis of the K-ras oncogene revealed the mutation at codon 12 substituting the wild-type glycine (GGT) for aspartic acid (GAT) in all cancerous lesions of patients with PBM. Simultaneous two-point mutations from the wild-type glycine (GGC) to arginine (CGC) at codon 13 associated with the mutation at codon 12 were also found in one case of gallbladder carcinoma and one case of bile duct carcinoma. CONCLUSIONS: K-ras gene mutation is involved in the carcinogenesis of biliary tract epithelium in patients with PBM, and appears to be a high risk factor for carcinogenesis of the biliary tract.

Adult↗
PubMed1988

Neurogenesis in the vomeronasal epithelium of adult garter snakes: 3. Use of H3-thymidine autoradiography to trace the genesis and migration of bipolar neurons.

Use of H3-thymidine autoradiography and unilateral vomeronasal (VN) axotomy has permitted us to demonstrate directly the existence of VN stem cells in the adult garter snake and to trace continuous bipolar neuron development and migration in the normal VN and deafferentated VN epithelium in the same animal. The vomeronasal epithelium and olfactory epithelium of adult garter snakes are both capable of incorporating H3-thymidine. In the sensory epithelium of the vomeronasal organ, H3-thymidine-labeled cells were initially restricted to the base of the undifferentiated cell layer in animals surviving 1 day following H3-thymidine injection. With increasing survival time, labeled cells progressively migrated vertically within the receptor cell column toward the apex of the bipolar neuron layer. In both the normal and denervated VN epithelium, labeled cells were observed through the 56 days of postoperative survival. In the normal epithelium, labeled cells were always located within the matrix of the intact receptor cell columns. However, labeled cells of the denervated epithelium were always located at the apical front of the newly formed cell mass following depletion of the original neuronal cell population. In addition, at postoperative days 28 and 56, labeled cells of the denervated VN epithelium achieved neuronal differentiation and maturation by migrating much farther away from the base of the receptor cell column than the labeled cells on the normal, unoperated contralateral side. This study directly demonstrates that basal cells initially incorporating H3-thymidine are indeed stem cells of the VN epithelium in adult garter snakes.(ABSTRACT TRUNCATED AT 250 WORDS)

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