371 research outputs found
Transforming growth factor-alpha stimulates proliferation of rat sertoli cells
No full textThe number of Sertoli cells is positively correlated with the number of germ cells produced in the testis, but the regulation of Sertoli cell proliferation and final density is poorly understood. Using non-aggregated Sertoli cells from 8 to 9-day-old rat testes, highly enriched by lectin binding, we explored effects of Sertoli cell growth factor candidates in vitro. Proliferation was assessed by H-3-thymidine incorporation, bromodeoxyuridine labeling and supravital staining, and FSH was used as positive control. Transforming growth Factor-alpha (TGF-alpha) was found to stimulate Sertoli cell proliferation in a dose-dependent manner. Epidermal growth factor (EGF) and betacellulin mimicked the effect, demonstrating specificity of the response as they share receptors with TGF-alpha. Insulin-like growth factor I and II, acidic and basic fibroblast growth factor and stem cell factor lacked significant stimulatory effects. We conclude that EGF/TGF-alpha is a growth factor for Sertoli cells in vitro, possibly contributing to paracrine regulation of Sertoli cell proliferation in vivo. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved
Interleukin-1 is a potent paracrine growth and differentiation factor for immature rat Sertoli cells
No full textAplicabilidade dos frameworks de implementa??o da gest?o do conhecimento : estudo de caso em empresas do setor cal?adista
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Previous issue date: 2009-08-18Esta ? uma pesquisa qualitativa, sendo um estudo de caso m?ltiplo, onde se realizou an?lise de documentos e entrevistas em profundidade, com corte transversal. Ela tem como base o estudo de seis frameworks de implementa??o da gest?o do conhecimento, que s?o ferramentas que direcionam as empresas a encontrarem o melhor caminho para a solu??o dos seus problemas. Essa pesquisa foi aplicada em tr?s empresas do setor cal?adista. Como resultados a que a pesquisa chegou, pode-se dizer: o n?mero de categorias com mais dificuldades apresentadas pelas empresas de grande porte foi menor, j? o n?mero de categorias com mais dificuldades apresentadas pela empresa de m?dio porte foi maior; as empresas de grande porte apresentaram mais facilidades em pontos relevantes, como estrat?gia, suporte da lideran?a, sistemas de informa??o, comunica??o e estrutura; as empresas de grande porte apresentaram ambas tr?s categorias com mais dificuldades, sendo que a empresa A apresentou mais dificuldades em capital humano, sistema de recompensas e treinamento, enquanto o caso piloto apresentou mais dificuldades em capital humano, sistema de recompensas e cultura. Ao se comparar o quadro final com o quadro dos frameworks que serviram de base para essa pesquisa, percebe-se que as empresas A, B e caso piloto n?o se encaixam em nenhum framework, o que permite concluir que nenhuma das empresas tem de fato a gest?o do conhecimento implementada em suas empresas. Isto porque as empresas capacitadas, que seriam a empresa A e o caso piloto, ambas tiveram o n?mero de entrevistados que apresentou facilidades igual ao n?mero de entrevistados que apresentou dificuldades no t?pico processo, que aparece em todos os frameworks, o que n?o permite concluir se as empresas apresentam mais facilidade ou mais dificuldade em rela??o a esse t?pico
Promovendo à saúde ao atleta de voleibol: a multidimensionalidade na gestão do cuidado de saúde e enfermagem
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Programa de Pós-Graduação em Enfermagem, Florianópolis, 2013.A presente tese de doutorado está inserida na linha de pesquisa Políticas, Gestão e Avaliação do Cuidado em Saúde e Enfermagem do Grupo de Estudos e Pesquisas em Administração, Gerência do Cuidado e Gestão Educacional em Enfermagem e Saúde - GEPADES. Trata-se de um estudo envolvendo a gestão do cuidado a saúde e enfermagem do atleta de voleibol de alto rendimento. O ambiente esportivo, em especial o voleibol, mostrou-se como um terreno fértil para a realização de um estudo que abrangesse a saúde do jogador de voleibol, visto que esse espaço é carregado de especificidades e peculiaridades no seu enredo, sendo transversalizado por inúmeros condicionantes e determinantes que perpassam o contexto social e da saúde do atleta. A enfermagem é uma profissão que permea diferentes campos de atuação do ciclo do viver humano, que promove a saúde das pessoas e com isso amplia os horizontes de seus profissionais. Assim, as questões de pesquisa foram: Como o atleta de voleibol de alto rendimento vem experienciando o cuidado a saúde? E, quais significados atribuem a essa vivência na perspectiva da complexidade? O objetivo central do estudo foi de construir uma matriz de conhecimentos substantivos sobre o fenômeno que abrange a gestão do cuidado de saúde e enfermagem do atleta de voleibol de alto rendimento na perspectiva do pensamento complexo, a partir da compreensão dos significados atribuídos pelos referidos atletas sobre o cuidado a sua saúde. Para tal ancorou-se no referencial teórico do paradigma da complexidade, no percurso metodológico da Grounded Theory ou Teoria Fundamentada nos Dados (TFD), a qual considera que as pessoas agem de acordo com o propósito interativo, seguindo seu próprio entendimento dentro de uma situação. Assim, considerou-se o cenário de relações, interações e associações peculiares do viver do12atleta, e a amostra teórica constituiu-se de 34 participantes entrevistados (atletas, ex-atletas, técnicos e dirigentes), distribuídos em 3 grupos amostrais, tendo como período de realização da coleta dos dados de fevereiro a setembro de 2013. Os resultados obtidos estão apresentados na forma de 4 manuscritos, assim organizados: no primeiro manuscrito, foi realizado uma profunda e refinada busca nas bases PUBMED, CINAHL, LILACS e SciELO num intervalo de tempo de 7 anos (janeiro de 2007 a agosto de 2013), quando pode-se certificar que a literatura envolvendo voleibol, cuidado e enfermagem é incipiente, praticamente inexistente, configurando um excelente campo para inserção da enfermagem; o segundo manuscrito, aponta que a gestão do voleibol transita entre o profissionalismo e o amadorismo, apresentando-se frágil, carente em estrutura e organização, comprometendo assim a organização de um sistema de gestão de cuidado a saúde do atleta; o terceiro manuscrito, conduz a uma viagem pelos significados atribuídos pelos atletas a saúde, ao cuidado e a doença, constituindo o trinômio saúde-cuidado-doença no voleibol, ficou evidenciado que os jogadores possuem uma visão segmentada sobre o trinômio, explicitando o entendimento de que o corpo é considerado apenas o instrumento de trabalho e não o instrumento do viver; no quarto e último manuscrito, descreve a configuração da tese de forma geral, perpassa pela origem e confecção das 4 categorias emergidas no estudo e suas inter-relações com as subcategorias, até chegar na configuração do fenômenos central ?Gestão do cuidado no contexto do jogador de voleibol de alto rendimento: (sobre)vivendo na multidimensionalidade do ambiente esportivo?. A partir de uma reflexão crítica sobre o conjunto dos manuscritos, evidencia-se que a gestão do cuidado a saúde e enfermagem no voleibol é um campo muito denso e intenso, porém ainda um pouco inóspito, que carece de maior atenção e valorização pela importância que representa no cenário esportivo. No conjunto dos resultados finais dessa tese, pode-se afirmar que "A gestão do cuidado a saúde e enfermagem ao atleta de voleibol de alto rendimento é complexa, dinâmica, pró-ativa, interdependente e perpassa por dessemelhantes interações entre atores sociais envolvidos no contexto esportivo", permitindo assim, a organização de um sistema de gestão de cuidado a saúde e enfermagem que contemple a totalidade do atleta de voleibol de alto rendimento.Abstract : The present doctorate's thesis is inserted in the line of research Politics, Management and Healthcare Evaluation in Health and Nursing in the Study and Research Group in Administration, Care Management and Educational Management in Nursing and Health - GEPADES (acronym in Portuguese). This is a study involving healthcare and nursing management in high performance volleyball athletes. The sports environment, especially the volleyball, showed itself a productive area in order to carry out a study which would cover the volleyball players? health, once this space is full of specificities and peculiarities in its plot, being involved by several conditioning and determining factors which are part of the social and health player's context. Nursing is a profession which permeates different playing fields in the cycle of human living, which promotes people's health and this way it amplifies their professionals' horizons. Thus, the questions in the research were: How has the high performance volleyball athlete been experiencing healthcare? And, which meanings do they attribute to this living in the perspective of complexity? The main goal in the study was to build a matrix of substantive knowledge about the phenomenon which covers healthcare and nursing management of a high performance athlete in a complex thought perspective, from the understanding on the attributed meanings by the mentioned athletes about the care to their health. In order to do that, the theoretical approach was based on the complexity paradigm, in the methods of Grounded Theory, which considers people to act according to an interactive purpose, following their own understanding inside a situation. This way, the scenario of relationship, interactions and peculiar associations of the athlete's life, and the theoretical sample is consisted of 35 participants who were interviewed (athletes, ex-athletes, coaches and the board of directors), distributed in 3 sample groups, while the period of data collection was from February to September, 2013. The results are presented in the form of 4 manuscripts organized in the following way: in the first manuscript, a14deep and careful search was carried out on the databases PUBMED, CINAHL, LILACS and SciELO in a time interval of 7 years (January, 2007 to August, 2013), when it is possible to certify that the literature involving volleyball, care and nursing is incipient, almost inexistent, making an excellent field for inserting nursing; the second manuscript tells that the volleyball management walks between professionalism and amateurism, showing itself fragile, needy in structure and organization, compromising the organization of a management system of the player's healthcare, the third manuscript leads to a trip through the meaning attributed by the athletes to health, care and disease, constituting the trinomial health-care-disease in volleyball, it was evident that the players have a segmented view about the trinomial, clarifying the understanding that the body is considered only a tool to work and not a living tool; the fourth and last manuscript describes the setting of the thesis in a general way, going through the origin and production of 4 categories emerged in the study and its interrelations with the subcategories, till it gets to the setting of the central phenomena "Caring management in the context of high performance volleyball player: surviving/living in the multidimensionality of sports environment". From a critical reflection about the set of manuscripts, it is possible to stress that the management of healthcare and nursing in volleyball is a very dense and intense field, however, still a little inhospitable which needs more attention and value due to the importance it represents in the sports scenario. In the set of the final results of this thesis, it is possible to affirm that "The healthcare and nursing management to the high performance athlete is complex, dynamic, pro-active, interdependent and has different interactions between social actors involved in the sports context", allowing this way, the organization of a management system of healthcare and nursing which contemplates the whole high performance volleyball athlete
Phytoestrogen resveratrol suppresses steroidogenesis by rat adrenocortical cells by inhibiting cytochrome P450 c21-hydroxylase
No full textBackground and Aim: The phytoestrogen resveratrol is found in grapes, mulberries and peanuts, all of which are consumed regularly by humans. Resveratrol is also used in chemotherapy against cancer and aging and as a cardioprotectant. The aim of the present study was to characterize the effects of resveratrol on rat adrenal steroidogenesis and to study the underlying mechanism. Methods: Adrenocortical cells were isolated from the adrenal glands of normal male rats ( in vitro) and from male rats administered resveratrol in their diet for 12 weeks ( ex vivo). Cells from resveratrol-treated and non-treated rats were tested ex vivo for responsiveness to ACTH and cells from normal rats were tested in vitro for responsiveness to ACTH in the presence and absence of resveratrol. Corticosterone and progesterone production were measured by RIA and expression of steroidogenic enzymes analyzed by PAGE/Western blotting. Results: Corticosterone production was inhibited 47% by 50 mu M resveratrol in vitro and 20% ex vivo, while progesterone production was elevated to 400% of the control value in in vitro experiments. Resveratrol treatment decreased adrenal cytochrome P450 c21-hydroxylase expression in vivo and cell culture conditions. No changes in cell viability or morphology were caused by exposure to resveratrol in both ex vivo and in vitro experiments. Conclusion: Resveratrol suppresses corticosterone production by primary rat adrenocortical cell cultures in vitro and ex vivo by inhibiting cytochrome P450 c21-hydroxylase. Copyright (c) 2005 S. Karger AG, Basel
Perfil ocupacional de trabalhadores rurais expostos a agrot?xicos na Regi?o das Miss?es, RS
No full textThe Brazil has an intensive use of agricultural inputs in its national production,
among them stand out pesticides. In turn, the Rio Grande do Sul leads in the fourth
place in the ranking of the states that most commercialize pesticides in the country.
The farmers make up the population group most exposed to pesticides, since their
handling is part of their work activity. The study had to objective to analyze the
occupational profile of rural workers exposed to pesticides in the Region of Miss?es,
RS. Quantitative research, with a cross-sectional, descriptive and explicative design.
It was used random sampling by conglomerates in two-stage, with selected 12
municipalities in the first internship and 292 farmers in the second internship. The
study included rural workers aged 18 years or over, with at least 15 hours a week in
agricultural activities and using pesticides. In obtaining the data, the first stage
consisted of an interview in the agricultural establishments through a data collection
instrument prepared by the authors, with sociodemographic variables, time of
pesticide use, amount and type of pesticides, practices during the preparation and
pesticide application, previous poisoning and rural workers perceptions of the risk of
pesticide use. Secondly, the cholinesterase was measured in a blood sample and the
number of micronuclei in the oral mucosa. Statistical analysis was performed in
software R (3.4.3), with a chi-square test to verify the association between exposure
factors and main variables (risk perception and use of complete PPE), considering a
5% level of significance. As results main, it was verified that many rural workers do
not associate the use of pesticides with intoxication symptoms. In Santo Ant?nio das
Miss?es, RS, the exposed group presented a higher incidence of micronuclei when
compared to the individuals of the group not exposed to pesticides. The values for
the exams erythrocyte cholinesterase are within the reference standards, not
presenting significant difference between the groups. Contrary results are observed
for levels cholinesterase plasma, presenting a significant difference between the
groups exposed and not exposed to pesticides. Finally, there is a need for public
policies to monitor rural workers exposed to pesticides.O Brasil apresenta em sua produ??o nacional uma intensa utiliza??o de insumos
agr?colas, dentre eles destacam-se os agrot?xicos. Por sua vez, o Rio Grande do Sul
lidera em quarto lugar no ranking dos Estados que mais comercializam agrot?xicos
no pa?s. Os agricultores comp?em o grupo populacional mais exposto a agrot?xicos,
visto que o manuseio deste faz parte de sua atividade laboral. O estudo teve por
objetivo analisar o perfil ocupacional de trabalhadores rurais expostos a agrot?xicos
na Regi?o das Miss?es, RS. Pesquisa quantitativa, com delineamento transversal,
descritiva e explicativa. Utilizou-se amostragem aleat?ria por conglomerados em dois
est?gios, com sele??o de 12 munic?pios do primeiro est?gio e 292 agricultores no
segundo est?gio. Participaram do estudo, trabalhadores rurais com 18 anos ou mais
de idade, com no m?nimo 15 horas por semana nas atividades de agricultura e com
uso de agrot?xicos. Na obten??o dos dados, a primeira etapa constituiu-se em uma
entrevista nos estabelecimentos agropecu?rios atrav?s de um instrumento de coleta
de dados elaborado pelos autores, com vari?veis sociodemogr?ficas, tempo de uso
de agrot?xicos, quantidade e tipo de agrot?xicos, pr?ticas durante o preparo e
aplica??o do agrot?xico, intoxica??es pr?vias e percep??es dos trabalhadores rurais
quanto ao risco do uso de agrot?xicos. Em um segundo momento realizou-se a
dosagem da colinesterase em amostra de sangue e o n?mero de micron?cleos em
mucosa oral. A an?lise estat?stica foi realizada no software R (3.4.3), com teste de
qui-quadrado para verificar associa??o entre fatores de exposi??o e vari?veis
principais (percep??o do risco e uso do EPI completo), considerando o n?vel de 5%
de signific?ncia. Como resultados principais, verificou-se que muitos trabalhadores
rurais n?o associam o uso de agrot?xicos a sintomas de intoxica??o. Em Santo
Ant?nio das Miss?es, RS, o grupo exposto apresentou maior incid?ncia de
micron?cleos quando comparado com os indiv?duos do grupo n?o exposto a
agrot?xicos. Os valores para os exames de colinesterase eritrocit?ria encontram-se
dentro dos padr?es de refer?ncia, n?o apresentando diferen?a significativa entre os
grupos. Resultados contr?rios s?o observados para os n?veis de colinesterase
plasm?tica, apresentando diferen?a significativa entre os grupos exposto e n?o
exposto a agrot?xicos. Por fim, verifica-se a necessidade de pol?ticas p?blicas para o
monitoramento de trabalhadores rurais expostos aos agrot?xicos
Impact of uteroplacental insufficiency on postnatal rat male gonad
No full textPrenatal events such as intrauterine growth restriction can affect gonadal development of the offspring and have an impact on reproductive health. To investigate the effects of intrauterine growth restriction induced by uterine artery ligation on the postnatal rat testis. Pregnant rats underwent uterine artery ligation at day 19 of gestation. Offspring were killed at 5, 20 and 40 days post-partum (dpp). At killing, one gonad was snap-frozen in liquid nitrogen and processed for RNA and steroid extraction. The other gonad was formalin-fixed for histology. Gene expression was analyzed by TaqMan Low-Density Array. Intratesticular testosterone, estradiol and serum gonadotrophins were measured. Thirty genes were dysregulated in intrauterine growth-restricted rats compared to controls, among which markers of Sertoli cell and Leydig cell function, cell metabolism and growth factors. Testis weights were significantly reduced at 5 and 20 dpp in intrauterine growth-restricted rats and caught-up by 40 dpp Accordingly, Sertoli cell number was significantly lower in 5 dpp intrauterine growth-restricted rats. At 20 dpp, intratesticular testosterone was significantly increased in intrauterine growth-restricted rats, whereas serum gonadotrophins were unchanged. IUGR altered the gene expression in the rat testes up to peripubertal age and reduced testis size and Sertoli cell number in neonatal age. Multiple mechanisms encompassing genetic changes and steroid production by the testis may be involved in the catch-up growth phase that restored testis size by 40 dpp Permanent consequences on organ function and gamete integrity cannot be excluded and deserve further investigations
Impact of uteroplacental insufficiency on ovarian follicular pool in the rat
No full textAbstract Background A low oxygen supply to the fetus causes intrauterine growth restriction and can affect gonadal development of the offspring, having a potential impact on fertility. We investigated histology and gene expression in the postnatal rat ovary after fetal hypoxia induced by uterine artery ligation. Methods Sprague-Dawley rats underwent uterine artery ligation at day 19 of gestation. Offspring were sacrificed at 5, 20 and 40 days post-partum. Follicles were counted and classified in hematoxylin-eosin stained sections. Gene expression of 90 genes was analyzed by TaqMan® Low Density Array. Results A significantly lower number of total and primordial follicles was detected in 20 days post-partum intrauterine growth restricted animals. Follicle density was not different at 40 days post-partum, suggesting that compensatory mechanisms occurred during the pre-pubertal window. Uterine artery ligation modified the expression of 24 genes involved in different cellular functions, among which proliferation, apoptosis and metabolism. Conclusion Ovarian follicle pool was affected by fetal hypoxia in early life, but this effect did not persist in puberty. Genes involved in cellular processes were affected at all ages, potentially implying long-term genetic alterations. Further analyses are needed to elucidate later effects of fetal hypoxia on ovarian function and fertility
Influence of long-term dietary administration of procymidone, a fungicide with anti-androgenic effects, or the phytoestrogen genistein to rats on the pituitary-gonadal axis and Leydig cell steroidogenesis
No full textProcymidone is a fungicide with anti-androgenic properties, widely used to protect fruits from fungal infection. Thereby it contaminates fruit products prepared for human consumption. Genistein-containing soy products are increasingly used as food additives with health-promoting properties. Therefore we examined the effects of long-term dietary administration (3 months) of the anti-androgen procymidone (26 center dot 4 mg/animal per day) or the phytoestrogen genistein (21 center dot 1 mg/animal per day) to rats on the pituitary-gonadal axis fit vivo, as well as on Leydig cell steroidogenesis and on spermatogenesis ex vivo. The procymidone-containing diet elevated serum levels of LH and testosterone and, furthermore, Leydig cells isolated from procymidone-treated animals displayed an enhanced capacity for producing testosterone in response to stimulation by hCG or dibutyryl cAMP, as well as elevated expression of steroidogenic acute regulatory protein (StAR), cytochrome P450 side-chain cleavage (P450 scc) and cytochrome P450 17 alpha (P450c17). In contrast, the rate of DNA synthesis during stages VIII and IX of spermatogenesis in segments of seminiferous tubules isolated from genistein-treated rats was decreased without accompanying changes in the serum level of either LH or testosterone. Nonetheless, genistein did suppress the ex vivo steroidogenic response of Leydig cells to hCG or dibutyryl cAMP by down-regulating their expression of P450 scc. Considered together, our present findings demonstrate that long-term dietary administration of procymidone or genistein to rats exerts different effects on the pituitary-gonadal axis in vivo and on Leydig cell steroidogenesis ex vivo. Possibly as a result of disruption of hormonal feedback control due to its anti-androgenic action, procymidone activates this endocrine axis, thereby causing hyper-gonadotropic activation of testicular steroidogenesis. In contrast, genistein influences spermatogenesis and significantly inhibits Leydig cell steroidogenesis ex vivo without altering the serum level of either LH or testosterone
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