498 research outputs found

    Overexpression of mitochondrial sirtuins alters glycolysis and mitochondrial function in HEK293 cells

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    SIRT3, SIRT4, and SIRT5 are mitochondrial deacylases that impact multiple facets of energy metabolism and mitochondrial function. SIRT3 activates several mitochondrial enzymes, SIRT4 represses its targets, and SIRT5 has been shown to both activate and repress mitochondrial enzymes. To gain insight into the relative effects of the mitochondrial sirtuins in governing mitochondrial energy metabolism, SIRT3, SIRT4, and SIRT5 overexpressing HEK293 cells were directly compared. When grown under standard cell culture conditions (25 mM glucose) all three sirtuins induced increases in mitochondrial respiration, glycolysis, and glucose oxidation, but with no change in growth rate or in steady-state ATP concentration. Increased proton leak, as evidenced by oxygen consumption in the presence of oligomycin, appeared to explain much of the increase in basal oxygen utilization. Growth in 5 mM glucose normalized the elevations in basal oxygen consumption, proton leak, and glycolysis in all sirtuin over-expressing cells. While the above effects were common to all three mitochondrial sirtuins, some differences between the SIRT3, SIRT4, and SIRT5 expressing cells were noted. Only SIRT3 overexpression affected fatty acid metabolism, and only SIRT4 overexpression altered superoxide levels and mitochondrial membrane potential. We conclude that all three mitochondrial sirtuins can promote increased mitochondrial respiration and cellular metabolism. SIRT3, SIRT4, and SIRT5 appear to respond to excess glucose by inducing a coordinated increase of glycolysis and respiration, with the excess energy dissipated via proton leak. © 2014 Barbi de Moura et al

    Studies of Copaifera luetzelburgii Harms in reproductive pharmacology: In vivo and in vitro approaches

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    The objective of this study was to evaluate the estrogenic and anti-estrogenic actions, as well as the reproductive and foetal toxicity, of the ethanol extract from Copaifera luetzelburgii (EEtOH-Cl). In the experiment of (anti) estrogenicity, nulliparous Wistar rats were treated for 3 days with EEtOH-Cl (125, 250 and 500 mg/kg); estradiol (E, 5 μg/kg); E + EEtOH-Cl; tamoxifen (T, 4mg/kg). This extract presented estrogenic activity by increasing the relative weight (%) of the uterus of rats treated at doses of 125, 250 and 500 mg/kg (0.267 ± 0.016*, 0.231 ± 0.014*, 0.242 ± 0.015*), and it showed anti-estrogenic activity when associated with estradiol (0.116 ± 0.006*, 0.103 ± 0.06*, 0.098 ± 0.05*), respectively. For assessment of toxicity in pregnancy, the animals were divided into two groups and treated daily with EEtOH-Cl. In the first group, the effect of the extract on the development of pregnancy from first to seventh day was observed, and in the second group, from 8 to 21 days, there was no change of these parameters or the viability of the progeny when the study assessed reproductive and foetal toxicity; however, there was shortening of pregnancy (125 mg/kg) without affecting the progeny. In the in vitro study, uterine strips of pregnant (P) and non-pregnant (NP) females were used. In both groups, half received EEtOH-Cl (vo) for 13 days (treated females - T), and the other half received EEtOH-Cl directly to the isolated organ bath system (untreated - NT). In vitro study on the uterus of pregnant animals pretreated with doses of 250 and 500 mg/kg showed that there was inhibition of KCl 80-induced phasic contractions (0.490 ± 0.110, 0.540 ± 0.092), respectively. Also, the contractions induced by oxytocin were inhibited at a dose of 500 mg/kg (0.380 ± 0.109). In non-pregnant, non-treated females, the extract at a concentration of 125 μg/mL (0.180 ± 0.062) also inhibited the contractions induced by oxytocin. Thus, EEtOH-Cl demonstrated estrogenic activity, but when combined with estradiol, it demonstrated anti-estrogenic activity. It did not induce toxicity in the progenitors or in the progeny, and it inhibited isometric contractions induced by oxytocin and KCl 80 mM in pregnant and non-pregnant rats.Keywords: Copaifera luetzelburgii, (anti-)estrogenicity, reproductive toxicity, phasic contractionsAfrican Journal of Biotechnology Vol. 12(24), pp. 3864-387

    Perfil microbiológico da carne de frangos abatidos artesanalmente e na indústria, comercializados na grande Recife-PE

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    Considerando o elevado consumo da carne de frango no contexto nacional e mais especificamente na cidade do Recife, onde o abate clandestino ainda é intenso, objetivou-se delinear o perfil microbiológico da carne de frango disponível no mercado, comparando-se os produtos advindos de abatedouro industrial e artesanal e verificar se os produtos atendiam às especificações dos padrões recomendados pela legislação. Determinou-se o Número Mais Provável (NMP) de coliformes totais e termotolerantes, bem como realizou-se a pesquisa de Salmonella spp. e Aeromonas spp., além da contagem de bactérias aeróbias mesófilas, psicrófilas e Staphylococcus spp.. Foram analisadas 24 amostras, sendo que 12 advindas do processamento de frigoríficos industriais, resfriadas e comercializadas. As outras 12 amostras foram provenientes de abatedouro artesanal e comercializadas sem refrigeração. Nos resultados obtidos, a contagem de Staphylococcus spp., a determinação do NMP de coliformes totais e termotolerantes apresentaram valores acima dos permitidos nas carcaças artesanais, enquanto que, as pesquisas de Salmonella spp. e Aeromonas spp. não apresentaram diferença significativa. Nas carcaças artesanais o número de bactérias mesófilas foi 2,6 vezes maior que nas industriais, enquanto que no número de psicrófilas/pisicotróficas não houve diferença significativa entre as amostras. Algumas amostras não estão dentro dos padrões recomendados pela legislação

    Treinamento de força e seus efeitos sobre a área de secção transversa e perímetro celular de miócitos do gastrocnêmio de Rattus novergicus

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    O treinamento de força é uma das modalidades de exercício físico mais praticadas na atualidade. O objetivo do presente estudo foi comparar a área e o perímetro de miócitos do gastrocnêmio de ratos (Rattus novergicus) submetidos a um protocolo crônico de 25 sessões de treinamento de força. Os resultados indicaram aumento da área e do perímetro celular do grupo treinado, em relação ao grupo controle (não treinado). A hipertrofia celular promove aumento da força e manutenção neuromuscular de maneira positiva. Conclui-se que o treinamento de força é uma alternativa não medicamentosa que promove o aumento de força, verificado pela hipertrofia muscular, e pode auxiliar no tratamento de diversas doenças que carecem desta valência física. ABSTRACT Strength training and its effects on the cross-section área and mobile perimeter of rattus novergicus gastrocnemioStrenght training is one of the most popular choices of physical conditioning training nowadays. The objective of the current study was to compare the area and the perimiter of rats’ (Rattus novergicus) gastrocnemius miocytes, submitted to a chronical 25 strenght training sessions. The results indicate increasing of the cell area and perimeter on the experimental group when compared to the control gruoup (not trained at all during the study). The cell hypertrophy promotes raising of the muscle strenght and nerumuscular maintaince in a positive way. It is conclued that the stenght training is a non-phamacological alternative that promotes muscular strenght raising, verified by the muscular hypertrophy, and can help on the treatment of several diseases that need this physical variable

    Diagnosis : a future field of medical activity.

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    O sequenciamento de ?ltima gera??o (NGS) ? um tipo de tecnologia de sequenciamento de DNA que usa o sequenciamento paralelo de m?ltiplos fragmentos pequenos de DNA. Essa tecnologia permitiu um aumento dram?tico na velocidade (e uma diminui??o no custo) na qual o genoma de um indiv?duo pode ser sequenciado. O sequenciamento de Sanger ? usado para confirmar a presen?a de muta??es espec?ficas identificadas pela NGS em situa??es cl?nicas, devido ? maior precis?o dos m?todos tradicionais de sequenciamento, embora essa pr?tica esteja sendo questionada. A NGS pode ser apropriada para diagnosticar dist?rbios gen?ticos suspeitos quando ? improv?vel que o sequenciamento de um ?nico gene forne?a um diagn?stico. Pain?is de genes baseados em NGS s?o usados clinicamente em certas neoplasias hematol?gicas, e os primeiros testes de painel gen?tico para tumores s?lidos. Outras utiliza??es, como o diagn?stico de infec??es e a triagem de pessoas saud?veis continuam sendo investigados.Next Generation Sequencing (NGS) is a type of DNA sequencing technology that uses parallel sequencing of multiple small fragments of DNA. This technology has allowed for a dramatic increase in speed (and a decrease in cost) in which an individual's genome can be sequenced. Sanger sequencing is used to confirm the presence of specific mutations identified by NGS in clinical situations due to the greater accuracy of traditional sequencing methods, although this practice is being questioned. NGS may be appropriate to diagnose suspected genetic disorders when single gene sequencing is unlikely to provide a diagnosis. NGS-based gene panels are used clinically in certain hematological malignancies, and the first genetic panel tests for solid tumors. Other uses, such as the diagnosis of infections and the screening of healthy people, continue to be investigated

    The Microfloral Analysis of Secondary Caries Biofilm around Class I and Class II Composite and Amalgam Fillings

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    <p>Abstract</p> <p>Background</p> <p>Secondary caries is responsible for 60 percent of all replacement restorations in the typical dental practice. The diversity of the bacterial sources and the different types of filling materials could play a role in secondary caries. The aim of this study was to determine and compare the microbial spectrum of secondary caries biofilms around amalgam and composite resin restorations.</p> <p>Methods</p> <p>Clinical samples were collected from freshly extracted teeth diagnosed with clinical secondary caries. Samples were categorized into four groups according to the types of restoration materials and the classification of the cavity. Biofilms were harvested from the tooth-restoration interface using a dental explorer and after dilution were incubated on special agars. The bacteria were identified using the biochemical appraisal system. Statistical calculations were carried out using SPSS11.5 software to analyze the prevalence of the bacteria involved in secondary caries.</p> <p>Results</p> <p>Samples from a total of four groups were collected: two groups were collected from amalgam restorations, each had 21 samples from both Class I and Class II caries; and the other two groups were from composite resin restorations, each had 13 samples from both class I and class II caries. Our results showed: (1) Anaerobic species were dominant in both restoration materials. (2) In terms of the types of individual bacteria, no significant differences were found among the four groups according to the geometric mean of the detected bacteria (P > 0.05). However, there were significant differences among the detected bacteria within each group (P < 0.05). The composition of each bacterium had no statistical difference among the four groups (P > 0.05), but showed significant differences among the detected bacteria in each group (P < 0.05). (3) Among the four groups, there were no significant differences for the detection rate of each bacterium (P > 0.05), however, the detection rate of each bacterium within each group was statistically different among the detected bacteria (P < 0.05).</p> <p>Conclusions</p> <p>The proportion of obligatory anaerobic species was much greater than the facultative anaerobic species in the biofilm of secondary caries. Statistically, the materials of restoration and the location of secondary caries did not show any significant effects on the composition of the microflora.</p
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