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Proliferation of the superficial epithelium of ovaries in senile female rats following oral administration of conjugated equine estrogens

PERNICONI, Sergio Eduardo; SIMÕES, Manuel de Jesus; SIMÕES, Ricardo dos Santos; HAIDAR, Mauro Abi; BARACAT, Edmund C; SOARES JR, Jose Maria
Fonte: Faculdade de Medicina / USP Publicador: Faculdade de Medicina / USP
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.67%
OBJECTIVE: To evaluate the effect of different concentrations of estrogen on the ovarian superficial epithelium in senile female rats. Design: Fifty female rats at 15 months of age and with irregular estrous cycles were selected and randomly divided into five experimental groups containing equal numbers of animals in each: GPROP, control group receiving vehicle only; GE0.05mg, group receiving conjugated equine estrogens (CEE) at a dose of 50 µg/kg; GE0.5mg, group receiving CEE at 500 µg/kg; GE1mg, group receiving CEE at 1 mg/kg; and GE2mg, receiving CEE at 2 mg/kg. The length of treatment was 21 days. After this period, the animals were anesthetized and the ovaries were fixed in 10% formaldehyde and processed for routine histology. Histomorphology was analyzed by light microscopy, and histomorphometrics were evaluated using the Imagelab program. RESULTS: In the GPROP and GE0.05mg groups, the superficial epithelium of the ovary had a simple cuboidal shape, and as the estrogen dose increased, the epithelium thickened, with pseudo-stratified or stratified epithelium appearing in the GE2mg group. The animals in the group given the highest estrogen dose (GE2mg) showed the thickest ovarian epithelium and the largest perimeter and surface area of the surface ovarian epithelium (P < 0.01). However...

Regeneration of the Corneal Epithelium after Debridement of its Central Region: An Autoradiographic Study on Rabbits

BARBOSA, Flavia Leao; FARIA-E-SOUSA, Sidney Julio de; GOES, Rejane Maira; HADDAD, Antonio
Fonte: TAYLOR & FRANCIS INC Publicador: TAYLOR & FRANCIS INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.62%
Purpose: To investigate the proliferative behavior of the corneal and limbal epithelia after debridement on the central region of the rabbit cornea. Methods: After scraping a circular epithelial area, 5 mm in diameter, in the center of the cornea, (3)H-thymidine ((3)H-TdR) was injected intravitreally, and the rabbits killed from 1 to 49 days afterward. The cornea, together with the adjacent conjunctiva, was processed for autoradiography. Results: The regenerating epithelium at the center of the cornea exhibited high frequencies of labeled nuclei when compared to controls. The mitotic indexes for the limbus were comparable in experimental and control eyes. The unique basal stratum of the limbal epithelium exhibited quick proliferation and vertical migration in all eyes. Cells that remained labeled for four weeks or more were observed throughout the corneal epithelium, including its basal stratum, and this did not depend on epithelial damage. Conclusion: Corneal epithelium wounds are healed by sliding and proliferation of cells surrounding the epithelial gap without any evidence for the participation of the limbal epithelium. Daughter cells labeled with (3)H-TdR were visualized in all layers of the corneal epithelium up to 7 weeks after the DNA precursor injection. However...

Morphological and autoradiographic studies on the corneal and limbal epithelium of rabbits

GOES, Rejane Maira; BARBOSA, Flavia Leao; FARIA-E-SOUSA, Sidney Julio De; HADDAD, Antonio
Fonte: WILEY-LISS Publicador: WILEY-LISS
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.59%
The investigation was centered on the morphological features of the conjunctiva-cornea transition (limbus) of the rabbit eye and the proliferative behavior of its epithelium. The eyes were processed for examination with light and electron microscopy, as well as for autoradiography after intravitreal injection of [H-3]thymidine ([H-3]TdR). At the sites of extraocular muscle insertion, the vascularization of the stroma extended to the peripheral cornea, and the limbal epithelium was thin with its basal stratum made up by clear cuboidal cells. In between the muscle insertions, the cuboidal clear cells, as well as the stroma blood vessels; were scarce. At the light microscope level, the basement membrane was distinct in the cornea but not in the limbus or the conjunctiva. Autoradiographs demonstrated that, at the limbus, the basal cells migrated very quickly to the suprabasal region and remained there up to the 28-day interval. Labeled cells were identified in all epithelial layers of the cornea, including the basal one, at 21 and 28 days but not in the limbal basal clear cells. The rate of renewal of conjunctival epithelium was similar to that observed for the transition with scarce clear cells. The high-resolution autoradiographs demonstrated that the basal cuboidal clear limbal cells exhibit a quick renewal and that they are not label-retaining cells. These latter ones were detected all over the corneal epithelium and in the suprabasal layers of the limbus up to 28 days...

Effects of Cobalt Chloride in Junctional Epithelium and Reduced Enamel Epithelium of the Rat Maxillary First Molar

FELIPPINI, Ana Luiza de C.; LOPES, Ruberval Armando; SALA, Miguel Angel; WATANABE, Ii-Sei; LOPES, Tulio Roberto V. P.; ISSA, Joao Paulo M.; RIBAS, Jose Paulo
Fonte: SOC CHILENA ANATOMIA Publicador: SOC CHILENA ANATOMIA
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
36.65%
Cobalt is one of the main components of cast metal alloys broadly used in dentistry. It is the constituent of 45 to 70% of numerous prosthetic works. There are evidences that metal elements cause systemic and local toxicity. The purpose of the present study was to evaluate the effects of cobalt on the junctional epithelium and reduced enamel epithelium of the first superior molar in rats, during lactation. To do this, 1-day old rats were used, whose mothers received 300mg of cobalt chloride per liter of distilled water in the drinker, during lactation. After 21 days, the rat pups were killed with an anesthetic overdose. The heads were separated, fixed in ""alfac"", decalcified and embedded in paraffin. Frontal sections stained with hematoxylin and eosin were employed. Karyometric methods allowed to estimate the following parameters: biggest, smallest and mean diameters, D/d ratio, perimeter, area, volume, volume/area ratio, eccentricity, form coefficient and contour index. Stereologic methods allow to evaluate: cytoplasm/nucleus ratio, cell and cytoplasm volume, cell number density, external surface/basal membrane ratio, thickness of the epithelial layers and surface density. All the collected data were subjected to statistic analysis by the non-parametric Wilcoxon-Mann-Whitney test. The nuclei of the studied tissues showed smaller values after karyometry for: diameters; perimeter...

Use of scanning electron microscopy for the evaluation of intestinal epithelium integrity

Gomide Junior, Marcio Heber; Sterzo, Elton Vinícius; Macari, Marcos; Boleli, Isabel Cristina
Fonte: Sociedade Brasileira de Zootecnia Publicador: Sociedade Brasileira de Zootecnia
Tipo: Artigo de Revista Científica Formato: 1500-1505
ENG
Relevância na Pesquisa
36.68%
Propõe-se, neste trabalho, o uso de microscopia eletrônica de varredura para avaliar perda de epitélio intestinal da mucosa intestinal de pintos machos e fêmeas submetidos a prolongado jejum pós-eclosão de água e ração. Dois segmentos do duodeno, jejuno e íleo por ave foram coletados e processados pelo método de rotina para microscopia eletrônica de varredura. Seis diferentes graus de perda de epitélio intestinal foram determinados: grau 0, vilos normais, sem extrusão; grau 1, vilos com pequenos pontos de extrusão; grau 2, vilos com perda de epitélio no ápice; grau 3, vilos com perda de epitélio na região apical; grau 4, vilos com perda de epitélio em sua metade superior; grau 5: vilos sem epitélio; grau 6: vilo quebrado. As três regiões intestinais das fêmeas apresentaram aproximadamente 90% de seus vilos normais (graus 0 e 1), enquanto nos machos ocorreu 38% de vilos normais no duodeno e jejuno e 85% no íleo. Além disso, machos apresentaram graus mais acentuados de perda de epitélio (graus 3, 4, 5 e 6) que as fêmeas (grau 3). Os dados indicaram que a mucosa intestinal de pintos machos é mais sensível a prolongado jejum pós-eclosão que a de pintos fêmeas. A microscopia eletrônica de varredura pode ser usada como um método de rotina seguro para a caracterização e quantificação de perda de epitélio intestinal.; This work reports the use of scanning electron microscopy to evaluate intestinal epithelium loss in broilers. Intestinal mucosa of male and female chicks submitted to prolonged period post-hatching of water and feed deprivation was evaluated. Two segments of the duodenum...

Germ line Cysts and the Formation of the Germinal Epithelium During the Female Gonadal Morphogenesis in Cyprinus Carpio (Teleostei: Ostariophysi: Cypriniformes)

Mazzoni, Talita Sarah; Grier, Harry J.; Quagio-Grassiotto, Irani
Fonte: Wiley-liss Publicador: Wiley-liss
Tipo: Conferência ou Objeto de Conferência Formato: 1581-1606
ENG
Relevância na Pesquisa
36.67%
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); The formation of both germline cysts and the germinal epithelium is described during the ovary development in Cyprinus carpio. As in the undifferentiated gonad of mammals, cords of PGCs become oogonia when they are surrounded by somatic cells. Ovarian differentiation is triggered when oogonia proliferate and enter meiosis, becoming oocytes. Proliferation of single oogonium results in clusters of interconnected oocytes, the germline cysts, that are encompassed by somatic prefollicle cells and form cell nests. Both PGCs and cell nests are delimited by a basement membrane. Ovarian follicles originate from the germline cysts, about the time of meiotic arrest, as prefollicle cells surround oocytes, individualizing them. They synthesize a basement membrane and an oocyte forms a follicle. With the formation of the stroma, unspecialized mesenchymal cells differentiate, and encompass each follicle, forming the theca. The follicle, basement membrane, and theca constitute the follicle complex. Along the ventral region of the differentiating ovary...

Ultrastructural study of the follicular epithelium in oocytes of Pachycondyla (Neoponera) villosa ants (Hymenoptera : Ponerinae)

Mathias, MIC; Caetano, F. H.
Fonte: Inst Histol Embriol-conicet Publicador: Inst Histol Embriol-conicet
Tipo: Artigo de Revista Científica Formato: 53-60
ENG
Relevância na Pesquisa
36.62%
Insect oocytes are surrounded by the follicular epithelium which is simple and cuboidal, wih the mainly functions of: synthesis of vitellin membrane and chorion and synthesis and transport of hemolymph products (proteins). In Pachycondyla (Neoponera) villosa ants workers aged less than 10 days do not present the formation of ovarian follicles (oocytes, nurse cells and follicular cells) indicating that vitellogenesis starts at approximately 10 days of age. Studies of participation of the follicular epithelium in Pachycondyla (Neoponera) villosa showed that in stage I oocytes the epithelium does not present the opening of intercellular spaces. In stage II these spaces begin to be observed together with separation of the follicular epithelium from the oocyte surface. In stage III two types of material were observed in the intercellular spaces: electrodense material in the basal region and compacted material in apical one as well as follicular epithelium/oocytes interface suggesting that the extraovarian material that reach oocytes undergoes some type of modification during passage through the intercellular spaces. The follicular epithelium spaces in queen are bigger than in workers oocytes.

Regeneration of the Corneal Epithelium after Debridement of its Central Region: An Autoradiographic Study on Rabbits

Barbosa, Flavia Leao; de Faria-e-Sousa, Sidney Julio; Goes, Rejane Maira; Haddad, Antonio
Fonte: Taylor & Francis Inc Publicador: Taylor & Francis Inc
Tipo: Artigo de Revista Científica Formato: 636-645
ENG
Relevância na Pesquisa
36.62%
Purpose: To investigate the proliferative behavior of the corneal and limbal epithelia after debridement on the central region of the rabbit cornea. Methods: After scraping a circular epithelial area, 5 mm in diameter, in the center of the cornea, (3)H-thymidine ((3)H-TdR) was injected intravitreally, and the rabbits killed from 1 to 49 days afterward. The cornea, together with the adjacent conjunctiva, was processed for autoradiography. Results: The regenerating epithelium at the center of the cornea exhibited high frequencies of labeled nuclei when compared to controls. The mitotic indexes for the limbus were comparable in experimental and control eyes. The unique basal stratum of the limbal epithelium exhibited quick proliferation and vertical migration in all eyes. Cells that remained labeled for four weeks or more were observed throughout the corneal epithelium, including its basal stratum, and this did not depend on epithelial damage. Conclusion: Corneal epithelium wounds are healed by sliding and proliferation of cells surrounding the epithelial gap without any evidence for the participation of the limbal epithelium. Daughter cells labeled with (3)H-TdR were visualized in all layers of the corneal epithelium up to 7 weeks after the DNA precursor injection. However...

Morphological and autoradiographic studies on the corneal and limbal epithelium of rabbits

Goes, Rejane Maira; Barbosa, Flavia Leao; De Faria-E-Sousa, Sidney Julio; Haddad, Antonio
Fonte: Wiley-liss Publicador: Wiley-liss
Tipo: Artigo de Revista Científica Formato: 191-203
ENG
Relevância na Pesquisa
36.59%
The investigation was centered on the morphological features of the conjunctiva-cornea transition (limbus) of the rabbit eye and the proliferative behavior of its epithelium. The eyes were processed for examination with light and electron microscopy, as well as for autoradiography after intravitreal injection of [H-3]thymidine ([H-3]TdR). At the sites of extraocular muscle insertion, the vascularization of the stroma extended to the peripheral cornea, and the limbal epithelium was thin with its basal stratum made up by clear cuboidal cells. In between the muscle insertions, the cuboidal clear cells, as well as the stroma blood vessels; were scarce. At the light microscope level, the basement membrane was distinct in the cornea but not in the limbus or the conjunctiva. Autoradiographs demonstrated that, at the limbus, the basal cells migrated very quickly to the suprabasal region and remained there up to the 28-day interval. Labeled cells were identified in all epithelial layers of the cornea, including the basal one, at 21 and 28 days but not in the limbal basal clear cells. The rate of renewal of conjunctival epithelium was similar to that observed for the transition with scarce clear cells. The high-resolution autoradiographs demonstrated that the basal cuboidal clear limbal cells exhibit a quick renewal and that they are not label-retaining cells. These latter ones were detected all over the corneal epithelium and in the suprabasal layers of the limbus up to 28 days...

Formação do epitelio germinativo durante a morfogenese e diferenciação gonodal em Cyprinus carpio (Teleostei:Cypriniformes) : analise estrutural e ultraestrutural das celulas germinativas e somaticas; Formation of germinal epithelium during gonodal morphogenesis and differentiation in Cyprinus carpio (Teleostei:Cypriniformes) : a structural and ultrastructural analysis of the germ and somatic cells

Talita Sarah Mazzoni
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 14/08/2009 PT
Relevância na Pesquisa
36.59%
Numa nova visão da morfogênese gonadal, sua descrição em Cyprinus carpio, mostra como a proliferação e diferenciação de células germinativas e somáticas a partir do primórdio gonadal levam à formação das diferentes estruturas ovarianas e testiculares e à constituição do epitélio germinativo que margeia as lamelas ovígeras e os túbulos testiculares. Em C. carpio, o primórdio gonadal é formado por células germinativas primordiais (CGPs) rodeadas por células somáticas. Após sucessivas divisões mitóticas das células somáticas, o tecido gonadal aumenta em comprimento e espessura. As CGPs isoladas entre células somáticas se dividem mitoticamente formando grupos de células germinativas, que se organizam em cordões contínuos, os quais são invadidos por células somáticas, levando à uma reorganização estrutural e diferenciação gonadal. Nas gônadas femininas, as oogônias são envolvidas por expansões citoplasmáticas das agora células pré-foliculares, formando cistos, delimitados por uma membrana basal em formação. Cada oogônia divide-se por mitose, formando novas oogônias ou entra em meiose originando os oócitos. Com a entrada e permanência em diplóteno, os oócitos, ainda no interior dos cistos...

Formação do epitélio germinativo e diferenciação das estruturas gonadais : uma análise comparativa entre grupos mais basais (Ostariophysi) e mais derivados (Atherinomorpha e Percomorpha) dentro de Teleostei; Formation of germinal epithelium during gonodal morphogenesis and differentiation in Cyprinus carpio (Teleostei:Cypriniformes) : comparative analysis between groups more basal (Ostariophysi) and more derivative (Atherinomorpha and Percomorpha) within Teleostei

Talita Sarah Mazzoni
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 29/08/2013 PT
Relevância na Pesquisa
36.59%
Considerando o status atual de conhecimento da morfogênese e diferenciação gonadal nos Teleostei frente à restrição de informações, especialmente em aspectos tangentes ao estabelecimento do epitélio germinativo e sua relação com a formação da estrutura gonadal tomou-se aqui como modelos biológicos Tanichthys albonubes, Gymnocorymbus ternetzi, Corydoras schwartzi, Amatitlania nigrofasciata e Poecilia reticulata, representando as séries Otophysi, Percomorpha e Atherinomorpha, visando estabelecer uma análise comparativa da diferenciação gonadal entre as espécies, considerando suas posições na escala filogenética. A proliferação e diferenciação de células germinativas e somáticas a partir do primórdio gonadal em T. albonubes, G. ternetzi, C. schwartzi, A. nigrofasciata e P. reticulata levam à formação das diferentes estruturas ovarianas e testiculares e à constituição do epitélio germinativo que margeia as lamelas ovígeras e os túbulos/lóbulos testiculares. Nesses animais, o primórdio gonadal é formado por células germinativas primordiais (CGPs) rodeadas por células somáticas. Após sucessivas divisões mitóticas das células somáticas, o tecido gonadal aumenta, originando uma gônada indiferenciada...

Morphological changes in the vaginal epithelium during the oestrous cycle of Calomys callosus (Rodentia, Cricetidae)

RODRIGUES,JEAN FÁBIO TORRES; FERRO,ELOISA AMÁLIA VIEIRA
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/1998 EN
Relevância na Pesquisa
36.62%
This study describes changes in the pattern of microridges, keratinization, desquamation, secretion, leukocyte infiltration as well as the increasing number of mitotic cells in the vaginal epithelium of Calomys callosus during the oestrous cycle. In proestrus, the epithelium is squamous and stratified with a fine layer of keratin and it is overlain by secretory prismatic cells. In oestrous, the epithelium is squamous, stratified and keratinized. In metoestrus, the epithelium is squamous and stratified with loss of the keratin layer. A leukocyte infiltration, extending from the base to the surface of the epithelial layer is also present. At the end of this phase, the surface cells start to become PAS-positive. In dioestrus, the epithelium is stratified. The superficial cells are prismatic, exhibiting the structural and ultrastructural characteristics of glycoprotein secreting cells supported by a layer of squamous cells. At the end of this phase, kerato-hyaline granules appear in the granular layer of the epithelium, indicating the beginning of the keratinization process, present in the next proestrus.

Maintenance of the corneal epithelium is carried out by germinative cells of its basal stratum and not by presumed stem cells of the limbus

Haddad,A.; Faria-e-Sousa,S.J.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 EN
Relevância na Pesquisa
36.59%
The purpose of this investigation was to analyze the proliferative behavior of rabbit corneal epithelium and establish if any particular region was preferentially involved in epithelial maintenance. [3H]-thymidine was injected intravitreally into both normal eyes and eyes with partially scraped corneal epithelium. Semithin sections of the anterior segment were evaluated by quantitative autoradiography. Segments with active replication (on) and those with no cell division (off) were intermingled in all regions of the tissue, suggesting that the renewal of the epithelial surface of the cornea followed an on/off alternating pattern. In the limbus, heavy labeling of the outermost layers was observed, coupled with a few or no labeled nuclei in the basal stratum. This suggests that this region is a site of rapid cell differentiation and does not contain many slow-cycling cells. The conspicuous and protracted labeling of the basal layer of the corneal epithelium suggests that its cells undergo repeated cycles of replication before being sent to the suprabasal strata. This replication model is prone to generate label-retaining cells. Thus, if these are adult stem cells, one must conclude that they reside in the corneal basal layer and not the limbal basal layer. One may also infer that the basal cells of the cornea and not of the limbus are the ones with the main burden of renewing the corneal epithelium. No particular role in this process could be assigned to the cells of the basal layer of the limbal epithelium.

Use of scanning electron microscopy for the evaluation of intestinal epithelium integrity

Gomide Junior,Marcio Heber; Sterzo,Elton Vinícius; Macari,Marcos; Boleli,Isabel Cristina
Fonte: Sociedade Brasileira de Zootecnia Publicador: Sociedade Brasileira de Zootecnia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2004 EN
Relevância na Pesquisa
36.68%
This work reports the use of scanning electron microscopy to evaluate intestinal epithelium loss in broilers. Intestinal mucosa of male and female chicks submitted to prolonged period post-hatching of water and feed deprivation was evaluated. Two segments of the duodenum, jejunum and ileum were taken per bird, and routinely processed by scanning electron microscopy. Six distinct degrees of epithelium loss were determined: degree 0, normal villi without apparent extrusion; degree 1, villi presenting small areas of epithelium loss; degree 2, villi without epithelium at the apex; degree 3, villi without epithelium at the apical region; degree 4, villi without epithelium in the upper half; degree 5, lack of epithelium in the whole villus; degree 6, loss of villi. Fasted male chicks presented only up to 38% of normal villi (degree 0 and 1) in the duodenum and jejunum, and 85% in the ileum, whereas fasted female chicks presented approximately 92% of normal villi in the three intestinal regions. Besides this, fasted male chicks had more accentuated degrees of epithelium loss (degrees 3, 4, 5 and 6) than females (degree 3). Data indicated that the intestinal mucosa in male chicks presents higher susceptibility to prolonged fasting than in females. Scanning electron microscopy is shown to be a reliable routine technique to characterize and quantify intestinal epithelium loss.

Proliferation of the superficial epithelium of ovaries in senile female rats following oral administration of conjugated equine estrogens

Perniconi,Sergio Eduardo; Simões,Manuel de Jesus; Simões,Ricardo dos Santos; Haidar,Mauro Abi; Baracat,Edmund C; Soares Jr,Jose Maria
Fonte: Faculdade de Medicina / USP Publicador: Faculdade de Medicina / USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2008 EN
Relevância na Pesquisa
36.67%
OBJECTIVE: To evaluate the effect of different concentrations of estrogen on the ovarian superficial epithelium in senile female rats. Design: Fifty female rats at 15 months of age and with irregular estrous cycles were selected and randomly divided into five experimental groups containing equal numbers of animals in each: GPROP, control group receiving vehicle only; GE0.05mg, group receiving conjugated equine estrogens (CEE) at a dose of 50 µg/kg; GE0.5mg, group receiving CEE at 500 µg/kg; GE1mg, group receiving CEE at 1 mg/kg; and GE2mg, receiving CEE at 2 mg/kg. The length of treatment was 21 days. After this period, the animals were anesthetized and the ovaries were fixed in 10% formaldehyde and processed for routine histology. Histomorphology was analyzed by light microscopy, and histomorphometrics were evaluated using the Imagelab program. RESULTS: In the GPROP and GE0.05mg groups, the superficial epithelium of the ovary had a simple cuboidal shape, and as the estrogen dose increased, the epithelium thickened, with pseudo-stratified or stratified epithelium appearing in the GE2mg group. The animals in the group given the highest estrogen dose (GE2mg) showed the thickest ovarian epithelium and the largest perimeter and surface area of the surface ovarian epithelium (P < 0.01). However...

Regional differences in cell surface patterns in normal human sulcular epithelium

Sánchez-Quevedo, M.C.; Moreu, G.; Campos, A.; García, J.M.; González-Jaranay, M.
Fonte: Murcia : F. Hernández Publicador: Murcia : F. Hernández
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
Relevância na Pesquisa
36.59%
Studies with scanning electron microscopy in the normal human sulcular epithelium are scarce, and no precise information exists about cell surface patterns along the epithelium, the frequencies of these patterns, or possible regional differences within the mouth. In five periodontal biopsy specimens each from the anterior and posterior region of the mouth, we observed three cell patterns on the basis of the overall appearance of morphological surface markers in the coronal and apical zones of sulcular epithelium: microvilli; microplicae; and pits. The percentage of keratinocytes showing the microvillous pattern in the surface of apical sulcular epithelium of the posterior region of the mouth was significantly higher than in the anterior region. We posit that the presente, in the bottom of the normal sulcular epithelium in the posterior region of the mouth, of mainly microvillous keratinocytes (the most undifferentiated and least desquamative type of keratinocyte, and thus the most vulnerable to bacterial colonization) can be associated with observations of longitudinal clinical studies of periodontal disease, which suggest that more severe clinical findings are found in the region of the molars.

Expression of retinoblastoma gene product in respiratory epithelium and sinonasal neoplasms: relationship with p16 and cyclin D1 expression

Schwerer, M.J.; Sailer, A.; Kraft, K.; Baczako, K.; Maier, H.
Fonte: Murcia : F. Hernández Publicador: Murcia : F. Hernández
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
Relevância na Pesquisa
36.67%
Transition from G1 to S phase of the cell cycle is mediated by interactions between the Retinoblastoma gene product (pRb), p16, and cyclin D1. To determine the expression of these proteins in the sinonasal mucosa immunohistochemistry was carried out on archived tissue sections from 46 patients (37 men, 9 women, age range 17 to 82 years, median 55 years). Nuclear immunostaining for these proteins was assessed and the expression rates (percentages of immunoreactive nuclei) in normal respiratory epithelium, inverted sinonasal papillomas, cylindrical (oncocytic) sinonasal papillomas, and squamous cell carcinomas were compared. Normal respiratory epithelium showed significantly higher pRb expression in surface cells compared to basal cells (p<0.05). In contrast, abundant pRb expression in surface and basal cells was detected in columnar differentiation in sinonasal papillomas and adjacent mucosa. Cuboidal and squamous metaplasia in inverted papillomas showed significantly reduced pRb expression in surface cells compared to columnar epithelium in inverted papillomas (p<0.05, respectively). Expression of p16 was detected in all epithelial cell layers of normal respiratory epithelium, sinonasal papillomas, and adjacent mucosa. Cuboidal and squamous metaplasia in inverted papillomas showed increased p16 expression in surface cells compared to columnar epithelium in inverted papillomas (p<0.05 between squamous metaplasia and columnar epithelium). Sinonasal squamous cell carcinomas showed the coexpression of pRb and p16. Expression rates of cyclin D1 higher than 10% were detected only in invasive carcinomas but not in carcinoma in situ...

Integrin Signaling Regulates Spindle Orientation in Drosophila to Preserve the Follicular-Epithelium Monolayer

Fernández-Miñán, Ana; Martín-Bermudo, María D.; González-Reyes, Acaimo
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 22195 bytes; application/pdf
ENG
Relevância na Pesquisa
36.59%
Epithelia act as important physiological barriers and as structural components of tissues and organs. In the Drosophila ovary, follicle cells envelop the germline cysts to form a monolayer epithelium. During division, the orientation of the mitotic spindle in follicle cells is such that both daughter cells remain within the same plane, and the simple structure of the follicular epithelium is thus preserved. Here we show that integrins, heterodimeric transmembrane receptors that connect the extracellular matrix to the cell's cytoskeleton 1 and 2, are required for maintaining the ovarian monolayer epithelium in Drosophila. Mosaic egg chambers containing integrin mutant follicle cells develop stratified epithelia at both poles. This stratification is due neither to abnormal cell proliferation nor to defects in the apical-basal polarity of the mutant cells. Instead, integrin function is required for the correct orientation of the mitotic apparatus both in mutant cells and in their immediately adjacent wild-type neighbors. We further demonstrate that integrin-mediated signaling, rather than adhesion, is sufficient for maintaining the integrity of the follicular epithelium. The above data show that integrins are necessary for preserving the simple organization of a specialized epithelium and link integrin-mediated signaling to the correct orientation of the mitotic spindle in this epithelial cell type.; Research in our laboratories is funded by the Spanish Ministerio de Ciencia y Tecnología (BMC2003-01512 and BFU2006-10934 to A. G-R; BMC2001-2298 and BFU2004-02840/BMC to M.D.M.-B.)...

Proliferation of the superficial epithelium of ovaries in senile female rats following oral administration of conjugated equine estrogens

Perniconi, Sergio Eduardo; Simões, Manuel de Jesus; Simões, Ricardo dos Santos; Haidar, Mauro Abi; Baracat, Edmund C; Soares Jr, Jose Maria
Fonte: Universidade de São Paulo. Faculdade de Medicina Publicador: Universidade de São Paulo. Faculdade de Medicina
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; Formato: application/pdf
Publicado em 01/01/2008 ENG
Relevância na Pesquisa
36.67%
OBJECTIVE: To evaluate the effect of different concentrations of estrogen on the ovarian superficial epithelium in senile female rats. Design: Fifty female rats at 15 months of age and with irregular estrous cycles were selected and randomly divided into five experimental groups containing equal numbers of animals in each: GPROP, control group receiving vehicle only; GE0.05mg, group receiving conjugated equine estrogens (CEE) at a dose of 50 µg/kg; GE0.5mg, group receiving CEE at 500 µg/kg; GE1mg, group receiving CEE at 1 mg/kg; and GE2mg, receiving CEE at 2 mg/kg. The length of treatment was 21 days. After this period, the animals were anesthetized and the ovaries were fixed in 10% formaldehyde and processed for routine histology. Histomorphology was analyzed by light microscopy, and histomorphometrics were evaluated using the Imagelab program. RESULTS: In the GPROP and GE0.05mg groups, the superficial epithelium of the ovary had a simple cuboidal shape, and as the estrogen dose increased, the epithelium thickened, with pseudo-stratified or stratified epithelium appearing in the GE2mg group. The animals in the group given the highest estrogen dose (GE2mg) showed the thickest ovarian epithelium and the largest perimeter and surface area of the surface ovarian epithelium (P < 0.01). However...

Beta-1 integrin loss leads to partial activation of pro-fibrotic pathways in the lens epithelium

Riggio, Brittany
Fonte: University of Delaware Publicador: University of Delaware
Tipo: Tese de Doutorado
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Duncan, Melinda K.; Integrins are heterodimeric adhesion receptors important for the detection of extracellular matrix, adhesion dependent signaling and tissue structure. Previously, the M. Duncan laboratory has shown that loss of ??1-integrin from the E12.5 mouse lens (??1MLR10) results in cell disorganization of the lens epithelium at E16.5, followed by its apoptosis at birth and ultimately in microphthalmia in adulthood. However, the identity of the cell signaling pathways that ??1-integrin controls in the lens and the mechanisms causing the cellular phenotype of these mice is not known. In order to investigate this, mice lacking ??1-integrin in the lens were obtained by mating mice harboring loxP sites around exon 3 of the ??1-integrin gene, to MLR10-cre mice, which express Cre-recombinase in all lens cells beginning at E10.5. mRNA levels of known genes involved in extracellular matrix and TGF-?? superfamily signaling were assessed by quantitative rtPCR SuperArray. Changes in protein expression and/or activation compared to wildtype C57Bl/6 controls were detected using immunofluorescence, and western blotting. This lead to the findings that loss of ??1-integrin leads to partial epithelial-mesenchymal transition of the lens epithelium...