El impacto del proceso de fusiones y adquisiciones en la Argentina sobre el mapa de grandes empresas: factores determinantes y transformaciones en el universo de las grandes empresas de capital local

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Ultrastructure of sheep primordial follicles cultured in the presence of indol acetic acid, EGF, and FSH

The aim of this study was to investigate the ultrastructural characteristics of primordial follicles after culturing of sheep ovarian cortical slices in the presence of indol acetic acid (IAA), Epidermal Growth Factor (EGF), and FSH. To evaluate ultrastructure of primordial follicles cultured in MEM (control) or in MEM containing IAA, EGF, and FSH, fragments of cultured tissue were processes for transmission electron microscopy. Except in the control, primordial follicles cultured in supplemented media for 6d were ultrastructurally normal. They had oocyte with intact nucleus and the cytoplasm contained heterogeneous-sized lipid droplets and numerous round or elongated mitochondria with intact parallel cristae were observed. Rough endoplasmic reticulum (RER) was rarely found. The granulosa cells cytoplasm contained a great number of mitochondria and abundant RER. In conclusion, the presence of IAA, EGF, and FSH helped to maintain ultrastructural integrity of sheep primordial follicles cultured in vitro. © 2011 Evelyn Rabelo Andrade et al.

Primordial germ cells (spermatogonial stem cells) of bullfrogs express sex hormone-binding globulin and steroid receptors during seasonal spermatogenesis

In vertebrate species, testosterone seems to inhibit spermatogonial differentiation and proliferation. However, this androgen can also be converted, via aromatase, into estrogen which stimulates spermatogonial differentiation and mitotic activity. During seasonal spermatogenesis of adult bullfrogs Lithobates catesbeianus, primordial germ cells (PGCs) show enhanced testosterone cytoplasm immunoexpression in winter; however, in summer, weak or no testosterone immunolabelling was observed. The aim of this study was to confirm if PGCs express stem cell markers-alkaline phosphatase (AP) activity and GFRα1 (glial-cell-line-derived neurotrophic factor)-and verify whether testosterone is maintained in these cells by androgen receptors (ARs) and/or sex hormone-binding globulin (SHBG) in winter. Furthermore, regarding the possibility that testosterone is converted into estrogen by PGCs in summer, the immunoexpression of estrogen receptor (ER)β was investigated. Bullfrog testes were collected in winter and in summer and were embedded in glycol methacrylate for morphological analyses or in paraffin for the histochemical detection of AP activity. GFRα1, AR, SHBG and ERβ expression were detected by Western blot and immunohistochemical analyses. The expression of AP activity and GFRα1 in the PGCs suggest that these cells are spermatogonial stem cells. In winter, the cytoplasmic immunoexpression of ARs and SHBG in the PGCs indicates that testosterone is maintained by these proteins in these cells. The cytoplasmic immunoexpression of ERβ, in summer, also points to an ER-mediated action of estrogen in PGCs. The results indicate a participation of testosterone and estrogen in the control of the primordial spermatogonia during the seasonal spermatogenesis of L. catesbeianus. © 2012 S. Karger AG, Basel.

Migraciones: universo teórico y objetos de investigaciones

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As mulheres de Klaxon: o universo feminino a partir dos modernistas

Pós-graduação em Artes - IA

A poesia visual de Miguel de Frias: o universo da visualidade na poesia

Pós-graduação em Artes - IA

Mulheres recipientes: recortes poéticos do universo feminino nas artes visuais

Pós-graduação em Artes - IA

Caminhos da cerâmica em Cunha: paneleiras, olarias e ateliês, elementos importantes na formação do histórico ceramista da cidade

Pós-graduação em Artes - IA

Show da fé e de sentido(s): o universo eclesial como mediação sociocultural

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Competência comunicativa de futuros professores frente à diversidade religiosa na abordagem do tema origens do universo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A inserção da criança pré-escolar no universo da cultura escrita pela mediação do desenho

Pós-graduação em Educação - FFC

A desarticulação do universo patriarcal em The awakening, de Kate Chopin

Pós-graduação em Estudos Literários - FCLAR

Modelos de universo e equação de estado na cosmologia

Pós-graduação em Física - IFT

O universo imaginário dos holandeses no Brasil seiscentista: um estudo da narrativa do viajante Joan Nieuhof

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Construção exploratória de uma prepnet para o português do Brasil: uma incursão linguistico-computacional no universo das preposições indicativas de espaço

Pós-graduação em Linguística e Língua Portuguesa - FCLAR