2,895 research outputs found

    Potent hepatoprotective effect in CCl4-induced hepatic injury in mice of phloroacetophenone from Myrcia multiflora

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    Background: This study investigated the hepatoprotective effect and antioxidant properties of phloroacetophenone (2',4',6'-trihydroxyacetophenone - THA), an acetophenone derived from the plant Myrcia multiflora. Material & Method: The free radical scavenging activity in vitro and induction of oxidative hepatic damage by carbon tetrachloride (CCl4) (0.5 ml/kg, i.p.) were tested in male Swiss mice (2595 g). Results: This compound exhibited in vitro antioxidant effects on FeCl2-ascorbate-induced lipid peroxidation (LPO) in mouse liver homogenate, scavenging hydroxyl and superoxide radicals, and 2,2-diphenyl-1-picrylhydrazyl. The in vivo assays showed that THA significantly (p<0.01) prevented the increases of hepatic LPO as measured by the levels of thiobarbituric acid-reactive substances, mitochondrial swelling. It also protected hepatocytes against protein carbonylation and oxidative DNA damage. Consistent with these observations, THA pre-treatment normalized the activities of antioxidant enzymes, such as catalase, glutathione peroxidase, and superoxide dismutase, and increased the levels of reduced glutathione (GSH) in CCl4-treated mice. In addition, THA treatment significantly prevented the elevation of serum enzymatic activities of alanine amino transferase, aspartate amino transferase, and lactate dehydrogenase, as well as histological alterations induced by CCl4. Silymarin (SIL) (24 mg/kg), a known hepatoprotective drug used for comparison, led to a significant decrease (p<0.01) in activities of theses enzymes in way very similar to that observed in pre-treatment with THA. Conclusion: These results suggest that the protective effects are due to reduction of oxidative damage induced by CCl4 resulting from the antioxidant properties of THA.Keywords: antioxidant; hepatoprotective; 2',4',6'-trihydroxyacetophenone; Myrcia multiflora; CCl4; Silymari

    INR Telemonitoring: Efficacy and Safety of a Telemonitoring Program in 453 Patients

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    Introdução: A análise do valor de INR em doentes hipocoagulados traz grande sobrecarga aos profissionais de saúde, despesas excessivas ao Serviço Nacional de Saúde (SNS) e perda de qualidade de vida dos doentes que se vêem obrigados a deslocações hospitalares frequentes. Não deveria constituir surpresa que a tecnologia esteja na vanguarda dos cuidados de saúde no século XXI e na área da anticoagulação têm sido desenvolvidos projectos de auto-monitorização do INR através do telefone, telemóvel ou internet. O objectivo deste estudo foi analisar a eficácia e segurança de um sistema de telemonitorização de INR implementado no nosso hospital em 2006. Material e Métodos: Estudo observacional, prospectivo dos 453 doentes incluídos no sistema de telemonitorização de INR desde 2006 até final Novembro 2010. A comunicação entre o doente e os profissionais de saúde é feita através de mensagens do telemóvel num sistema codificado e estandardizado que inclui informação sobre a manutenção ou alteração de terapêutica sempre que necessário e a data da próxima avaliação. Sempre que necessário o doente pode emitir um pedido de ajuda através de um código para o efeito. Na população estudada avaliaram-se os seguintes parâmetros: desistência do projecto de telemonitorização, necessidade de modificação da dose do anticoagulante, pedidos de esclarecimento por parte do doente, complicações hemorrágicas e internamento por INR > 10. Resultados: Da população estudada 53% eram do sexo feminino, idade média = 57 +/- 16. A percentagem dos valores de INR dentro do intervalo terapêutico obtida foi de 83%. Não se registaram desistências do projecto de telemonitorização. A percentagem de doentes com complicações hemorrágicas minor e major durante o follow-up foi de 0,4% e 0,2% respectivamente. Conclusões: O sistema de telemonitorização mostra-se seguro e eficaz no controlo à distância de análise de INR, permitindo controlo eficaz de INR com baixa prevalência de hemorragias major ou minor

    Relationship of health workers with their organization and work: a cross-cultural study

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    ABSTRACT We analyzed the differences, by Student’s t-test and ANOVA, between nurses and physicians from Portugal, Poland, Spain, and United Kingdom regarding their relationship with their work and organization. In total, 1,401 professionals answered the HSA-QHPR questionnaire. There are different levels of connection between physicians and nurses. The United Kingdom has the lowest levels of connection with the work while Portugal has the highest levels of relationship with the organization. The results provide guidelines for the development of policies and differential strategies aimed at improving the quality of healthcare service

    Flexible Blue-Light Fiber Amplifiers to Improve Signal Coverage in Advanced Lighting Communication Systems

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    Visible-light communication (VLC) based on white light-emitting diodes has recently attracted much attention to provide high-bitrate data communication in indoor environments. One of the remaining challenges to be resolved to enable the proliferation of VLC systems is related to channel attenuation and multiple path fading. Here, we introduce an advanced VLC system integrating an optical amplifier as a promising solution to overcome channel impairments, providing high bitrate coverage. The optical amplifier is a flexible fiber based on a poly(fluorene)-based lumophore doped within a di-ureasil organic-inor- ganic hybrid. Optical amplification is demonstrated for pre-amplifier and relay node scenarios, yielding a maximum gain of 5.9 G 0.2 dB and 3.7 G 0.2 dB, respectively, establishing the proposed approach as a promising cost-effective solution for VLCs. Additionally, numerical simulations show, for a realistic envi- ronment, a 207% improvement in the coverage area, using existing lighting infrastructure without extra cost.R.C.E. acknowledges funding from the European Research Council (ERC) under the European Union’s Ho- rizon 2020 research and innovation programme (grant agreement no. 818762 - SPECTRACON)

    The use of histological analysis for the detection of somatic embryos in sugarcane

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    The aim of this study was to establish an in vitro system for the induction, maturation and regeneration of somatic embryo in sugarcane from buds of cultivar RB 867515. Embryogenic calluses were obtained on semi-solid MS medium supplemented with 4.42 mg L-1 2,4-D. After four weeks of culture of explants on the callus induction medium, globular structures were obtained. At the end of 20 days in maturation medium, somatic embryos were observed. Histological analysis showed somatic embryos with caulinarand root apex, protodermal tissue, and the vascular system, which  apparently has no connection with the vascular tissue explant that gave rise to it confirming the presence of the somatic embryo. The embryos were transferred to regeneration medium containing 1 mg L-1 GA3 and BAP, and after 1 to 2 weeks of culture, green points were observed, indicating the beginning of the formation of shoots. Key words: Saccharum spp, bud culture, 2.4-D, morphogenetic pathway, embryogenesis, plant regeneration

    Purification, characterization and application of laccase from Trametes versicolor for colour and phenolic removal of olive mill wastewater in the presence of 1- hydroxybenzotriazole

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    Laccase forms (L1 and L2) from Trametes versicolor CCT 4521 showed a molecular mass of 66 kDa and optimum temperature around 40oC. The optimum pH (4.0 and 5.0) and Km (28.6 and 5 ìM) values usingsyringaldazine as substrate were found for L1 and L2, respectively. The enzymes were able to oxidize several compounds and were strongly inhibited by sodium azide, L-cysteine and dithiothreitol. The 75%of the N-terminal sequences were identical in both forms and similarities around 40 - 60% of laccases from wood-degrading fungi were observed. The use of 1-hydroxybenzotriazole as a mediator increased the compounds oxidized by laccases in olive mill wastewater

    Brazilian Bidens pilosa Linne´ yields fraction containing quercetin-derived flavonoid with free radical scavenger activity and hepatoprotective effects

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    Bidens pilosa is a plant used by Amazonian and Asian folks for some hepatopathies. The hydroethanol crude extract and three fractions were assessed for antioxidant and hepatoprotective effects. Higher levels of scavenger activity on the 1,1-diphenyl-2-picrylhydrazyl radical, inhibition of deoxyribose oxidation and lipid peroxidation in vitro were detected for the ethyl acetate fraction (IC50∼4.3-32.3 mg/ml) followed by the crude extract (IC50∼14.2-98.0 mg/ml). The ethyl acetate fraction, again followed by the crude extract, showed high contents of total soluble polyphenols (3.6±0.2 and 2.1±0.2 GAE/mg, respectively) and presence of a quercetin-derived flavonoid identified as quercetin 3,3′-dimethyl ether 7-Ο-β-D-glycopyranoside. Both products were assayed for hepatoprotector effects against CCl4-induced liver injury in mice. Markers of oxidative stress and hepatic injury were evaluated. The results showed that the 10-day pretreatments (15 mg/kg, p.o.) protected the livers against injury by blocking CCl4-induced lipid peroxidation and protein carbonylation and the DNA fragmentation was decreased (∼60%). The pretreatments avoided the loss of the plasma ferric reducing/antioxidant power and the elevation of serum transaminases and lactate dehydrogenase activities. The results suggest that the main constituents responsible for the hepatoprotective effects with free radical scavenger power associated are well extracted by performing fractionation with ethyl acetate. The findings support the Brazilian traditional use of this plant and justify further evaluations for the therapeutic efficacy and safety of the constituents of the ethyl acetate fraction to treat some liver diseases.Keywords: Bidens pilosa L.; hydroethanol maceration; ethyl acetate fractionation; free radical scavenger; hepatoprotection; CCl4 toxicit

    Low frequency of CD4(+) CD25(+) Treg in SLE patients: a heritable trait associated with CTLA4 and TGF gene variants

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    Background: CD4(+)CD25(+) regulatory T cells play an essential role in maintaining immune homeostasis and preventing autoimmunity. Therefore, defects in Treg development, maintenance or function have been associated with several human autoimmune diseases including Systemic Lupus Erythematosus (SLE), a systemic autoimmune disease characterized by loss of tolerance to nuclear components and significantly more frequent in females
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