Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Poult Sci ; 97(4): 1271-1282, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29444319

RESUMO

Feed and water supplementation with powdered hydrolyzable tannins from chestnut represents a valuable alternative strategy to antibiotics in animal nutrition. In this study, we evaluated the effects and safety of a water-soluble form of chestnut tannin (WST) in an in vitro model of chicken small intestinal epithelial cells (CSIEC). A chicken cell culture was established, and WST in concentrations of 0.025, 0.05, 0.1, and 0.2% were tested for cytotoxicity, cell proliferation, metabolic activity, production of reactive oxygen species, intracellular antioxidative potential, genotoxicity, and influence on the epithelia cell cycle. The tested concentrations showed a significant (P < 0.05) greater proliferative effect on CSIEC than the control medium (maximal proliferation at 0.1% WST as determined by optical density measurements). The 0.2% concentration of WST was cytotoxic, causing significantly higher (P < 0.05) nitric oxide and hydrogen peroxide production but with no short-term genotoxicity. Although increasing the concentration caused a decline in the metabolism of challenged cells (the lowest at 0.1% WST), metabolic activity remained higher than that in control cells. The antioxidant potential was 75% better and significantly (P < 0.05) higher in the 0.1% WST cultured cells compared to control. In conclusion, the cultured CSIEC are useful tools in basic and clinical research for the study of intestinal physiology, as they retain physiological and biochemical properties and epithelial morphology close to the original tissue and, in many ways, reflect the in vivo state. Our results indicate that WST exert a beneficial effect on intestinal epithelia, since they: i) stimulate proliferation of enterocytes; ii) increase antioxidative potential; iii) have no genotoxic effect; and iv) do not affect cellular metabolism. Our results reinforce the importance of WST as promising candidates for further evaluation and use in commercial broiler farm production.


Assuntos
Galinhas , Intestino Delgado/efeitos dos fármacos , Extratos Vegetais/química , Taninos/química , Animais , Antioxidantes/metabolismo , Técnicas de Cultura de Células , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células Epiteliais , Fagaceae/química , Intestino Delgado/fisiologia , Testes de Mutagenicidade/veterinária , Extratos Vegetais/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Taninos/toxicidade
2.
J Comp Neurol ; 521(1): 169-88, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-22700217

RESUMO

Although adult neurogenesis has been conserved in higher vertebrates such as primates and humans, timing of generation, migration, and differentiation of new neurons appears to differ from that in rodents. Sheep could represent an alternative model to studying neurogenesis in primates because they possess a brain as large as a macaque monkey and have a similar life span. By using a marker of cell division, bromodeoxyuridine (BrdU), in combination with several markers, the maturation time of newborn cells in the dentate gyrus (DG) and the main olfactory bulb (MOB) was determined in sheep. In addition, to establish the origin of adult-born neurons in the MOB, an adeno-associated virus that infects neural cells in the ovine brain was injected into the subventricular zone (SVZ). A migratory stream was indicated from the SVZ up to the MOB, consisting of neuroblasts that formed chain-like structures. Results also showed a long neuronal maturation time in both the DG and the MOB, similar to that in primates. The first new neurons were observed at 1 month in the DG and at 3 months in the MOB after BrdU injections. Thus, maturation of adult-born cells in both the DG and the MOB is much longer than that in rodents and resembles that in nonhuman primates. This study points out the importance of studying the features of adult neurogenesis in models other than rodents, especially for translational research for human cellular therapy.


Assuntos
Hipocampo/citologia , Neurogênese/fisiologia , Bulbo Olfatório/citologia , Ovinos/anatomia & histologia , Células-Tronco Adultas/fisiologia , Fatores Etários , Animais , Bromodesoxiuridina/metabolismo , Contagem de Células , Diferenciação Celular , Movimento Celular , Feminino , Proteínas de Fluorescência Verde/genética , Humanos , Ventrículos Laterais/citologia , Proteínas do Tecido Nervoso/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Fatores de Transcrição SOXB1/metabolismo , Transdução Genética
3.
Horm Behav ; 58(5): 737-46, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20692260

RESUMO

Production of new neurons continues throughout life in the subventricular zone (SVZ) and the dentate gyrus (DG) of the hippocampus and is influenced by both endocrine and social factors. In sheep parturition is associated with the establishment of a selective bond with the young based on an olfactory learning. The possibility exists that endocrine changes at parturition together with interactions with the young modulate cell proliferation in the neurogenic zones. In the present study, we first investigated the existence of cell proliferation in sheep. Newly born cells labeled by the cell proliferation marker 5-bromo-2'-deoxyuridine (BrdU) were found in the SVZ, the main olfactory bulb (MOB) and the DG and completely co-localized with Ki-67, another mitotic marker. Forty to 50% of the BrdU-labeled cells contained GFAP suggestive of the presence of neural stem cells. Secondly, parturition with or without interactions with the lamb for 2 days, down-regulated the number of BrdU-labeled cells in the 3 proliferation sites in comparison to no pregnancy. An additional control provided evidence that this effect is specific to early postpartum period: estrus with interactions with males did not affect cell proliferation. Our results provide the first characterization of neural cell proliferation in the SVZ, the DG and unexpectedly in the MOB of adult sheep. We hypothesize that the down-regulation of cell proliferation observed in the early postpartum period could facilitate the olfactory perceptual and memory demands associated with maternal behavior by favouring the survival and integration of neurons born earlier.


Assuntos
Encéfalo/fisiologia , Proliferação de Células , Comportamento Materno/fisiologia , Parto/fisiologia , Prenhez , Ovinos/fisiologia , Animais , Animais Recém-Nascidos , Encéfalo/citologia , Contagem de Células , Regulação para Baixo , Feminino , Masculino , Neurogênese/fisiologia , Neurônios/citologia , Neurônios/fisiologia , Período Pós-Parto/fisiologia , Gravidez , Células-Tronco/fisiologia
4.
Reprod Domest Anim ; 41(4): 268-74, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16869880

RESUMO

Semen production and trade is a worldwide industry. A framework, based on international standards is awaiting international and national regulation. In the perspective of biosecurity of the final product, critical notes can be made according to the semen production regulation and product safety. Process description brings the obligatory health standards for the production bulls, collection and processing of semen, identification, registration, worldwide distribution and insemination into discussion. Test frequency, test quality and demands, way of sampling and test consistency can influence product safety. New scientific knowledge can influence the value of the regulation. Whether a country is free of notifiable disease should influence decisions regarding necessary tests for the production bulls. The biosecurity of the semen production process is influenced by several factors. The effectiveness of the antibiotics used is questionable. The extenders for cryopreservation added to the semen can affect product safety. The way materials and storage containers have to be disinfected must be clear. In modern industry, tracking and tracing is an important issue. Worldwide differences in ways of identification of straws do not benefit a proper identification and registration throughout the process. Regulation could help improve the transparency of production and trade. Before anything concerning biohazard is implemented in regulation, each rule should be thoroughly based on scientific research where possible and furthermore it must be possible to enforce the regulation. The effort it takes to enforce the regulation should be in balance with the benefit it provides. An approach to alter regulation quickly is advisable. To produce a safe product that is accepted for international trade is of vital interest for the survival of artificial insemination (AI) in cattle.


Assuntos
Sistemas de Identificação Animal/veterinária , Bovinos/fisiologia , Preservação do Sêmen/veterinária , Sêmen , Manejo de Espécimes/veterinária , Sistemas de Identificação Animal/métodos , Sistemas de Identificação Animal/normas , Animais , Cooperação Internacional , Masculino , Controle de Qualidade , Segurança , Preservação do Sêmen/normas , Manejo de Espécimes/métodos , Manejo de Espécimes/normas
5.
Am J Emerg Med ; 8(4): 323-5, 1990 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2194468

RESUMO

A case of a patient with a hepatic abscess secondary to a fish or chicken bone is presented. Of interest is the fact that the abscess resulted from gastrointestinal perforation of the foreign object. A review of the literature of this unusual occurrence along with clues to making the diagnosis are discussed.


Assuntos
Corpos Estranhos , Abscesso Hepático/etiologia , Estômago , Humanos , Abscesso Hepático/patologia , Masculino , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA