1,228 research outputs found

    Impact of carvedilol on the mitochondrial damage induced by hypoxanthine and xantine oxidase: what role in myocardial ischemia and reperfusion?

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    OBJECTIVES: The cardioprotective effects of carvedilol (CV) may be explained in part by interactions with heart mitochondria. The objective of this work was to study the protection afforded by CV against oxidative stress induced in isolated heart mitochondria by hypoxanthine and xanthine oxidase (HX/XO), a well-known source of reactive oxygen species (ROS) in the cardiovascular system. METHODS: Mitochondria were isolated from Wistar rat hearts (n = 8) and incubated with HX/XO in the presence and in the absence of calcium. Several methods were used to assess the protection afforded by CV: evaluation of mitochondrial volume changes (by measuring changes in the optical density of the mitochondrial suspension), calcium uptake and release (with a fluorescent probe, Calcium Green 5-N) and mitochondrial respiration (with a Clark-type oxygen electrode). RESULTS: CV decreased mitochondrial damage associated with ROS production by HX and XO, as verified by the reduction of mitochondrial swelling and increase in mitochondrial calcium uptake. In the presence of HX and XO, CV also ameliorated mitochondrial respiration in the active phosphorylation state and prevented decrease in the respiratory control ratio (p < 0.05) and in mitochondrial phosphorylative efficiency (p < 0.001). CONCLUSIONS: The data indicate that CV partly protected heart mitochondria from oxidative damage induced by HX and XO, which may be useful during myocardial ischemia and reperfusion. It is also suggested that mitochondria may be a priority target for the protective action of some compounds

    Advantages in the use of carvedilol versus propranolol for the protection of cardiac mitochondrial function

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    BACKGROUND: Carvedilol is a neurohormonal antagonist of multiple action which is used in clinical practice for the treatment of congestive heart failure, mild to moderate hypertension and myocardial infarction. Previous results from our group have demonstrated that one of the main targets for the protective effect of carvedilol is the cardiac mitochondrial network. In-this work, we compare the effect of carvedilol with propranolol in different models of mitochondrial dysfunction and in the generation of transmembrane electric potential (EP). We further tested if carvedilol was able to inhibit the mitochondrial permeability transition (MPT) induced by doxorubicin and calcium-dependent cytochrome c release, a phenomenon frequently associated with apoptotic cell death. METHODS: Cardiac mitochondria were isolated by differential centrifugation. Oxygen consumption and mitochondrial EP were determined using an oxygen electrode and a tetraphenylphosphonium-sensitive electrode, respectively. Changes in mitochondrial volume and the release of cytochrome c were measured with spectrophotometric techniques. RESULTS: Propranolol, compared with carvedilol, had only a marginal effect, not only in protection against MPT induction, but also against oxygen consumption linked to the oxidation of external NADH, a process that is considered by several authors as key in the cardiotoxicity of doxorubicin. Regarding EP generation, propranolol had no effect, in contrast to carvedilol, which was confirmed to act as a protonophore. For the first time we also show that carvedilol inhibits the MPT induced by doxorubicin and calcium-dependent cytochrome c release. CONCLUSIONS: With this work, we further support the notion that carvedilol is effective in several models of mitochondrial dysfunction, particularly those involving oxidative stress. The results demonstrate that for some pathological conditions, carvedilol and propranolol have different mechanisms of action at the sub-cellular level, as propranolol seems to lack effectiveness in the protection of cardiac mitochondria

    Cost-effectiveness Analysis of Ocrelizumab for the Treatment of Relapsing and Primary Progressive Multiple Sclerosis in Portugal

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    Objectives: Ocrelizumab demonstrated significant clinical benefit for the treatment of relapsing (RMS) and primary progressive (PPMS) multiple sclerosis (MS), an incurable disease characterized by disability progression. This study evaluated the clinical and economic impact of ocrelizumab relative to current clinical practice, including other disease-modifying therapies (DMT), available in Portugal. Methods: Markov models for MS were adapted to estimate the impact of ocrelizumab across three patient populations: treatment-naïve RMS, previously treated RMS, and PPMS. Health states were defined according to the Expanded Disability Status Scale. For RMS, the model further captured the occurrence of relapses and progression to secondary progressive multiple sclerosis (SPMS). A lifetime time-horizon and Portuguese societal perspective were adopted. Results: For RMS patients, ocrelizumab was estimated to maximize the expected time (years) without progression to SPMS (10.50) relative to natalizumab (10.10), dimethyl fumarate (8.64), teriflunomide (8.39), fingolimod (8.38), interferon β-1a (8.33) and glatiramer acetate (8.18). As the most effective option, with quality-adjusted life year (QALY) gains between 0.3 and 1.2, ocrelizumab was found to be cost-saving relative to natalizumab and fingolimod, and presented incremental cost-effectiveness ratios (ICER) below €16,720/QALY relative to the remaining DMT. For PPMS patients, the ICER of ocrelizumab versus best supportive care was estimated at €78,858/QALY. Conclusions: Ocrelizumab provides important health benefits for RMS and PPMS patients, comparing favourably with other widely used therapies. In RMS, ocrelizumab was revealed to be either cost-saving or have costs-per-QALY likely below commonly accepted cost-effectiveness thresholds. In PPMS, ocrelizumab fills a clear clinical gap in the current clinical practice. Overall, ocrelizumab is expected to provide good value for money in addressing the need of MS patients.info:eu-repo/semantics/publishedVersio

    Analysis of antenal sensilla patterns of Rhodnius prolixus from Colombia and Venezuela

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    Antennal sensilla patterns were used to analyze population variation of domestic Rhodnius prolixus from six departments and states representing three biogeographical regions of Colombia and Venezuela. Discriminant analysis of the patterns of mechanoreceptors and of three types of chemoreceptors on the pedicel and flagellar segments showed clear differentiation between R. prolixus populations east and west of the Andean Cordillera. The distribution of thick and thin-walled trichoids on the second flagellar segment also showed correlation with latitude, but this was not seen in the patterns of other sensilla. The results of the sensilla patterns appear to be reflecting biogeographic features or population isolation rather than characters associated with different habitats and lend support to the idea that domestic R. prolixus originated in the eastern region of the Andes.Fil: Esteban, Lyda. Universidad Industrial de Santander; ColombiaFil: Angulo, Víctor Manuel. Universidad Industrial de Santander; ColombiaFil: Dora Feliciangeli, M.. Universidad de Carabobo; VenezuelaFil: Catala, Silvia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; Argentin

    Childhood socioeconomic position, adult socioeconomic position and social mobility in relation to markers of adiposity in early adulthood: evidence of differential effects by gender in the 1978/79 Ribeirao Preto cohort study

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    Background: Longitudinal studies drawn from high-income countries demonstrate long-term associations of early childhood socioeconomic deprivation with increased adiposity in adulthood. However, there are very few data from resource-poor countries where there are reasons to anticipate different gradients. Accordingly, we sought to characterise the nature of the socioeconomic status (SES)-adiposity association in Brazil. / Methods: We use data from the Ribeirao Preto Cohort Study in Brazil in which 9067 newborns were recruited via their mothers in 1978/79 and one-in-three followed up in 2002/04 (23–25years). SES, based on family income (salaries, interest on savings, pensions and so on), was assessed at birth and early adulthood, and three different adiposity measures (body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR)) ascertained at follow-up. The association between childhood SES, adult SES and social mobility (defined as four permutations of SES in childhood and adulthood: low–low, low–high, high–low, high–high), and the adiposity measures was examined using linear regression. / Results: There was evidence that the association between SES and the three markers of adiposity was modified by gender in both adulthood (P<0.02 for all outcomes) and childhood SES (P<0.02 for WC and WHR). Thus, in an unadjusted model, linear regression analyses showed that higher childhood SES was associated with lower adiposity in women (coefficient (95% confidence intervals) BMI: −1.49 (−2.29,−0.69); WC: −3.85 (−5.73,−1.97); WHR: −0.03 (−0.04,−0.02)). However, in men, higher childhood SES was related to higher adiposity (BMI: 1.03 (0.28,−1.78); WC: 3.15 (1.20, 5.09); WHR: 0.009 (−0.001, 0.019)) although statistical significance was not seen in all analyses. There was a suggestion that adult SES (but not adult health behaviours or birthweight) accounted for these relationships in women only. Upward mobility was associated with protection against greater adiposity in women but not men. / Conclusion: In the present study, in men there was some evidence that both higher childhood and adulthood SES was related to a higher adiposity risk, while the reverse gradient was apparent in women

    LINC complex-Lisl interplay controls MT1-MMP matrix digest-on-demand response for confined tumor cell migration

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    Cancer cells' ability to migrate through constricting pores in the tissue matrix is limited by nuclear stiffness. MT1-MMP contributes to metastasis by widening matrix pores, facilitating confined migration. Here, we show that modulation of matrix pore size or of lamin A expression known to modulate nuclear stiffness directly impinges on levels of MT1-MMP-mediated pericellular collagenolysis by cancer cells. A component of this adaptive response is the centrosome-centered distribution of MT1-MMP intracellular storage compartments ahead of the nucleus. We further show that this response, including invadopodia formation in association with confining matrix fibrils, requires an intact connection between the nucleus and the centrosome via the linker of nucleoskeleton and cytoskeleton (LINC) complex protein nesprin-2 and dynein adaptor Lis1. Our results uncover a digest-on-demand strategy for nuclear translocation through constricted spaces whereby confined migration triggers polarization of MT1-MMP storage compartments and matrix proteolysis in front of the nucleus depending on nucleus-microtubule linkage

    PROCESO DE CAMBIO CURRICULAR DEL CURSO DE GRADUACIÓN EN ENFERMERÍA DE LA UNIFESO: POTENCIALIDADES Y VULNERABILIDADES

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    Se objetivó en este estudio subrayar las potencialidades y vulnerabilidades del proceso del cambio curricular. Los sujetos de la encuesta fueron 43 educandos del segundo período de graduación en enfermería de la UNIFESO, que están insertos en el cambio curricular. Los resultados fueron presentados en unidades temáticas enfatizando las potencialidades y vulnerabilidades del proceso de cambio curricular. Entre las potencialidades, la primera es que el aprendizaje es facilitado por la interacción grupal, la segunda que el aprendizaje ocurre por la participación efectiva de los educandos, tercera, el aprendizaje y el dinamismo del proceso enseñanza-aprendizaje y la cuarta, la integración enseñanza-trabajo-ciudadanía como un diferencial en la formación. Siendo las vulnerabilidades cuestiones relacionadas a la estructura y organización curricular y relativas al proceso enseñanza-aprendizaje. Por consiguiente, se puede afirmar que el desafío puesto es transformar las tensiones generadas por el cambio curricular en momentos propiciadores y generar de las vulnerabilidades las grandes potencialidades del proceso de cambio.Objetivou-se neste estudo a destacar as potencialidades e vulnerabilidades do processo de mudança curricular. Os sujeitos da pesquisa foram 43 educandos do segundo período de graduação em enfermagem da UNIFESO, que estão inseridos na mudança curricular. Os resultados foram apresentados em unidades temáticas enfatizando as potencialidades e vulnerabilidades do processo de mudança curricular. Dentre as potencialidades à aprendizagem é facilitada pela interação grupal, a segunda a aprendizagem ocorre pela participação efetiva dos educandos, a terceira aprendizagem e o dinamismo do processo ensino-aprendizagem e a quarta a integração ensino-trabalho-cidadania como um diferencial na formação. Sendo as vulnerabilidades questões relacionadas à estrutura e organização curricular e relativos ao processo ensino-aprendizagem. Por conseguinte pode-se afirmar que o desafio posto é transformar as tensões geradas pela mudança curricular em momentos propiciadores e gerar das vulnerabilidades as grandes potencialidades do processo de mudanç

    Liposomes in tissue engineering and regenerative medicine

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    Liposomes are vesicular structures made of lipids that are formed in aqueous solutions. Structurally, they resemble the lipid membrane of living cells. Therefore, they have been widely investigated, since the 1960s, as models to study the cell membrane, and as carriers for protection and/or delivery of bioactive agents. They have been used in different areas of research including vaccines, imaging, applications in cosmetics and tissue engineering. Tissue engineering is defined as a strategy for promoting the regeneration of tissues for the human body. This strategy may involve the coordinated application of defined cell types with structured biomaterial scaffolds to produce living structures. To create a new tissue, based on this strategy, a controlled stimulation of cultured cells is needed, through a systematic combination of bioactive agents and mechanical signals. In this review, we highlight the potential role of liposomes as a platform for the sustained and local delivery of bioactive agents for tissue engineering and regenerative medicine approaches. liposomesscaffoldsdelivery systemsbioactive agentsstem cellsThe authors thank the Portuguese Foundation for Science and Technology for the PhD grant to N.S.M. (SFRH/BD/62465/2009), the post-doctoral grants of A.M. (SFRH/BPD/73663/2010). This study was also partly supported by POLARIS (FP7-REGPOT-2012-2013-1), RL3-TECT-NORTE-01-0124-FEDER-000020, co-financed by the North Portugal Regional Operational Programme (ON.2-O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF), the OsteoGraphy (PTDC/EME-MFE/2008) and MaxBone (PTDC/SAU-ENB/115179/2009) projects
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