8 research outputs found
Adição de extrato de açaí ao diluente de criopreservação do sêmen de touros.
O processo de criopreservação das células espermáticas é uma biotécnica importante para a reprodução animal, pois garante a rápida difusão de material com elevado mérito genético. Porém, os espermatozoides são expostos a efeitos negativos em sua estrutura e funcionalidade, principalmente ocasionados pela produção em excesso de espécies reativas ao oxigênio durante a criopreservação. Adicionalmente, existem diferenças de sensibilidade a congelação das células espermáticas entre os indivíduos, devido os diferentes ejaculados não suportarem a mesma resistência a congelação. Assim, diversas substâncias com ação antioxidante têm sido adicionadas aos meios diluidores de congelação do sêmen. Dessa forma, objetivou-se avaliar o efeito da adição de extrato de açaí ao diluente de criopreservação do sêmen de touros sobre a
morfologia, cinética e integridade da membrana plasmática das células espermáticas. Os ejaculados foram coletados de cinco touros que apresentavam baixa capacidade de congelação dos espermatozoides, sendo distribuídos nos grupos experimentais, controle (não recebeu extrato de açaí) e nos demais adicionou-se extrato de açaí nas proporções de, 5, 10, 15 ou 20mg/mL de diluente de congelação. As alterações espermáticas apresentaram efeito linear decrescente com a adição do extrato de açaí. Quando avaliada por epifluorescência, a integridade da membrana plasmática foi superior após a adição do extrato de açaí ao diluente de criopreservação. O extrato de açaí não apresentou influência sobre a cinética dos espermatozoides. A adição do extrato de açaí ao diluente de congelação garante melhor preservação da integridade estrutural da membrana plasmática de espermatozoides no sêmen com baixa tolerância ao processo de criopreservação.The cryopreservation process of sperm cells is a important biotechnology in the field of animal reproduction since it allows the fast spread from males of high genetic merit. Nevertheless, the spermatozoa are exposed to negative effects that affect on structure and functionality, mainly due to the excessive production of reactive oxygen species during the process. Moreover, there are sensitivity differences among individuals concerning the resistance of the cells, that is, they cannot resist to the same resistance to freezing. Therefore, several antioxidant substances have been added to the diluent media used in the preservation of semen. We evaluated the outcome of the addition of açaí extract to bull semen cryopreservation diluent with respect to kinetics,
morphology and plasma membrane integrity of sperm cells. The sperm samples were collected from five bulls whose spermatozoa had a history of low tolerance to the cryopreservation process. The samples were distributed between the control subset (to which açaí extract was not added) and the rest, which were added with açaí extract in the proportions of 5, 10, 15 or 20mg/mL of diluent during the freezing process. The sperm alterations presented a linear decreasing response to the addition of açaí extract. In the analysis by epifluorescence, the plasma membrane integrity was higher after the addition of açaí extract to the cryopreservation diluent. The açaí extract did not influence the kinectics of the spermatozoa. The addition of
açaí extract to the freezing diluent allows a better preservation of the structural integrity of the plasma membrane of spermatozoa in semen with low tolerance to the cryopreservation process
The use of açaí as a potential antioxidant for bovine semen cryopreservation
Semen cryopreservation is an important tool for animal reproduction due to its potential for fast dissemination of genetics from males with high genetic merit. However, cryopreservation protocols continue to provoke negative effects on sperm cell structure and function, thus leading to lower viability. This reduction in viability is correlated with excessive production of reactive oxygen species (ROS) that generate oxidative stress, which is responsible for lowering sperm motility, alteration in plasma membrane fluidity, and lipidic peroxidation. Due to these facts, it becomes necessary to add substances with the antioxidant potential for semen cryopreservation to confer additional protection to sperm cells. A variety of compounds from plants and fruits have been incorporated to such media due to their antioxidant potential. In such context, açaí has gained attention by researchers due to its substantial antioxidant capacity, particularly attributed to its polyphenolic fraction, which is rich in anthocyanins. Moreover, it also contains resveratrol and quercetin in its composition, which has activity against free radicals. In general terms, the antioxidant of natural sources (i.e., açaí) deserves special attention since it contributes to the preservation of the national flora, also displays a significant potential to improve the quality of frozen-thawed bovine semen
Expatriados, imigrantes e refugiados no Brasil: trajetórias e estratégias de integração econômica e social
In the early 2010s, Brazil started to receive two new inflows of immigrants – citizens from Mercosur countries and refugees, especially from Haiti –, creating a kind of hierarchy that distinguishes desirable and undesirable immigrants, granting different access to legal, social and cultural resources to their integration into society. This new kind of immigration, different from the flow from Europe, is the target of prejudice from society, making it more difficult for them to integrate socially and economically. Based on qualitative researches conducted with immigrants, this work aims to discuss comparatively the obstacles and strategies of economic and social integration which are used by three categories of migrants – expatriates, immigrants and refugees – to enter the Brazilian society and deal with mechanisms of migration control and restrictions in Brazil. Based on these results, it is possible to generate inputs to enhance Brazilian migration policy.No início dos anos 2010, o Brasil passou a receber dois novos fluxos de imigrantes - nacionais dos países do Mercosul e refugiados, especialmente haitianos -, criando um tipo de hierarquia distinguindo entre imigrantes desejáveis e indesejáveis, com acesso diferenciado a recursos legais, sociais e culturais para sua integração na sociedade. Esse novo tipo de imigração, em oposição ao fluxo de origem europeia, sofre preconceito da sociedade, dificultando sua integração social e econômica. Com base em pesquisas qualitativas realizadas com imigrantes, este trabalho pretende discutir de forma comparativa os obstáculos e estratégias de inserção econômica e social utilizadas por três categorias de migrantes - expatriados, imigrantes e refugiados - para se integrar à sociedade brasileira e lidar com mecanismos de controle de migração e restrições no Brasil. Com base nos resultados, é possível gerar insumos para o aperfeiçoamento da política migratória brasileira.
Influence of the male effect on follicular dynamics and pregnancy rate in lactating cows undergoing fixed-time artificial insemination
Direct antiviral therapy for treatment of hepatitis C: A real-world study from Brazil
Introduction and objectives: Direct antiviral agents (DAAs) including sofosbuvir (SOF), daclatasvir (DCV), simeprevir (SIM) and ombitasvir, paritaprevir and dasabuvir were introduced 2015 in Brazil for treatment of hepatitis C virus (HCV) infection. The aims of this study were to assess effectiveness and safety of HCV treatment with DAA in real-life world in a highly admixed population from Brazil. Materials and methods: All Brazilian reference centers for HCV treatment were invited to take part in a web-based registry, prospectively conducted by the Brazilian Society of Hepatology, to assess outcomes of HCV treatment in Brazil with DAAs. Data to be collected included demographics, disease severity and comorbidities, genotype (GT), viral load, DAA regimens, treatment side effects and sustained virological response (SVR). Results: 3939 patients (60% males, mean age 58 ± 10 years) throughout the country were evaluated. Most had advanced fibrosis or cirrhosis, GT1 and were treated with SOF/DCV or SOF/SIM. Overall SVR rates were higher than 95%. Subjects with decompensated cirrhosis, GT2 and GT3 have lower SVR rates of 85%, 90% and 91%, respectively. Cirrhosis and decompensated cirrhosis in GT1 and male sex and decompensated cirrhosis in GT3 were significantly associated with no SVR. Adverse events (AD) and serious AD occurred in 18% and 5% of those subjects, respectively, but less than 1% of patients required treatment discontinuation. Conclusion: SOF-based DAA regimens are effective and safe in the heterogeneous highly admixed Brazilian population and could remain an option for HCV treatment at least in low-income countries
Núcleos de Ensino da Unesp: artigos 2007
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Brazilian Flora 2020: Leveraging the power of a collaborative scientific network
International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora