271 research outputs found
Depression in Parkinson’s Disease: The Contribution from Animal Studies
Besides being better known for causing motor impairments, Parkinson’s disease (PD) can also cause many nonmotor symptoms, like depression and anxiety, which can cause significant loss of life quality and may not respond to regular drugs treatment. In this review, we discuss the depression in PD, based on data from studies in humans and rodents. Depression frequency seems higher in PD patients than in general population, despite high variation in data due to diagnosis disparities. Development of depression in PD seems more likely to be caused by the nigrostriatal pathway degeneration than as a consequence of the awareness of disease prognostic, and it seems to be related to dopaminergic, noradrenergic, and serotoninergic synapses deficits. The dopaminergic role could be more significant, since it can modulate the release of the others, and its depletion is progressive, due to the degenerative feature of PD. Highly regarded in major depression, serotonin can be depleted in rats after nigrostriatal damage, but data from human patients are more conflicting. Animal studies can help in understanding the neurobiological mechanisms of depression in PD and the pursuit for more effective drugs for its treatment, but they lack the complexity of the disease progression, especially the nondopaminergic degeneration
Effects of Hypericum perforatum on turning behavior in an animal model of Parkinson's disease
A Doença de Parkinson é uma doença neurodegenerativa relacionada à idade, caracterizada pela morte lenta e progressiva de neurônios dopaminérgicos da substância negra pars compacta. O Hypericum perforatum (H. perforatum) é um fitoterápico utilizado como antidepressivo, apresentando propriedades antioxidantes, anti-inflamatórias e nootrópicas. Neste trabalho, avaliaram-se os efeitos do tratamento com H. perforatum no comportamento rotatório de ratos no modelo da doença de Parkinson induzido pela administração unilateral de 6-OHDA no feixe prosencefálico medial. Ratos Wistar machos foram tratados com H. perforatum (100, 200 ou 400 mg/kg, v.o.) por 35 dias (do 28º dia antes até o 7º dia após a lesão). As rotações ipsilaterais e contralaterais à lesão foram registradas no 7º, 14º e 21º dias após a cirurgia. As três doses de H. perforatum utilizadas reduziram o número de rotações contralaterais, indicando um possível efeito neuroprotetor da planta. Porém, o H. perforatum não impediu a redução na expressão da enzima tirosina hidroxilase no estriado lesionado, quantificada por Western blot. Propomos que o H. perforatum possa bloquear o aumento da expressão dos receptores dopaminérgicos no estriado lesionado com 6-OHDA. Entretanto, estudos adicionais são necessários para identificar o mecanismo exato pelo qual o H. perforatum reduziu o número de rotações contralaterais. Os resultados do presente estudo sugerem o H. perforatum como um potencial agente terapêutico para a doença de Parkinson.Parkinson's disease (PD) is an age-related neurodegenerative disorder characterized by the slow and progressive death of dopaminergic neurons in the (substantia nigra pars compact). Hypericum perforatum (H. perforatum) is a plant widely used as an antidepressant, that also presents antioxidant and anti-inflammatory properties. We evaluated the effects of H. perforatum on the turning behavior of rats submitted to a unilateral administration of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle as an animal model of PD. The animals were treated with H. perforatum (100, 200, or 400 mg/kg, v.o.) for 35 consecutive days (from the 28th day before surgery to the 7th day after). The turning behavior was evaluated at 7, 14 and 21 days after the surgery, and the turnings were counted as contralateral or ipsilateral to the lesion side. All tested doses significantly reduced the number of contralateral turns in all days of evaluation, suggesting a neuroprotective effect. However, they were not able to prevent the 6-OHDA-induced decrease of tyrosine hydroxylase expression in the lesioned striatum. We propose that H. perforatum may counteract the overexpression of dopamine receptors on the lesioned striatum as a possible mechanism for this effect. The present findings provide new evidence that H. perforatum may represent a promising therapeutic tool for PD
Estudo e otimização de uma pilha de combustível de pequena potência (10W) e sua integração em equipamento portátil
Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia MecânicaCom o presente trabalho pretende-se, em termos globais, contribuir para o aprofundamento do conhecimento sobre as pilhas de combustível a hidrogénio através do estudo de uma pilha de combustível de pequena potência (10W) e a sua integração em equipamento portátil.
Em termos estruturais, de uma forma geral, esta dissertação engloba três partes distintas, uma parte inicial na qual se procede a uma revisão de literatura, uma segunda parte, na qual é efetuado um estudo acerca da implementação da pilha de combustível a hidrogénio no equipamento portátil escolhido, por fim, uma terceira parte na qual é apresentada uma simulação do funcionamento dessa pilha com a devida discussão sobre os resultados obtidos, bem como sobre as limitações do estudo.
Foram delineados três objetivos para este trabalho: o estudo teórico das pilhas de combustível, composto pelo estudo do seu princípio de funcionamento, das suas características, do tipo de combustível, das aplicações e dos desafios existentes neste tipo de tecnologia; o estudo comparativo entre as pilhas de combustível e outras tecnologias no mercado; e a implementação de uma pilha a hidrogénio num equipamento portátil escolhido por mim e estudo das suas características em funcionamento.
A implementação de uma pilha de combustível a hidrogénio num equipamento portátil foi conseguida através do recurso ao programa Matlab®. Assim, foi possível a simulação do funcionamento da pilha para o equipamento selecionado.
A simulação permitiu analisar e compreender o processo no interior da pilha de hidrogénio e o que esta transmite para o equipamento portátil.
Em termos de resultados, estes foram suficientes para se ajuizar sobre as curvas características típicas de uma pilha de hidrogénio, nomeadamente da variação da corrente e da tensão com a variação de carga aplicada na pilha de hidrogénio.Abstract: The intention with the present work, in global terms, is to contribute for a more profound understanding about the hydrogen fuel cells from the studies of a low power fuel cell (10W) and its integration on portable equipment.
In structural terms, in a general way, this thesis is assembled in three distinct parts, one consisting in a literature revision, a second in a study about the implementation of a hydrogen fuel cell in a particularly chosen portable equipment, and a third consisting in a simulation and discussion of obtained results of a fuel cell operation as well as study shortfalls.
There were three objectives to be considered for this work: the theoretical study of the fuel cell, consisting on the: (i) study of the operation principle, (ii) main features, (iii) fuel type, (iv) existing applications and (v) technology challenges; the study of its functioning characteristics and also the comparative study between fuel cells and other technologies available in the market and the implementation of a hydrogen fuel cell in a portable equipment chosen by me.
The implementation of a hydrogen fuel cell in a portable equipment was only possible resorting to the Matlab® program. Therefore, it was possible to simulate in the selected equipment the functioning of the fuel cell.
The simulation allowed the analysis and the understanding of the interior process of the hydrogen fuel cell and what it provides to the portable equipment.
Concerning results, these were more than enough to get the typical outline of the characteristic curves of a hydrogen fuel cell, mostly about the current and tension variation with the charge variation applied the hydrogen fuel cell
Effects of Hypericum perforatum on turning behavior in an animal model of Parkinson's disease
Parkinson's disease (PD) is an age-related neurodegenerative disorder characterized by the slow and progressive death of dopaminergic neurons in the (substantia nigra pars compact). Hypericum perforatum (H. perforatum) is a plant widely used as an antidepressant, that also presents antioxidant and anti-inflammatory properties. We evaluated the effects of H. perforatum on the turning behavior of rats submitted to a unilateral administration of 6-hydroxydopamine (6-OHDA) into the medial forebrain bundle as an animal model of PD. The animals were treated with H. perforatum (100, 200, or 400 mg/kg, v.o.) for 35 consecutive days (from the 28th day before surgery to the 7th day after). The turning behavior was evaluated at 7, 14 and 21 days after the surgery, and the turnings were counted as contralateral or ipsilateral to the lesion side. All tested doses significantly reduced the number of contralateral turns in all days of evaluation, suggesting a neuroprotective effect. However, they were not able to prevent the 6-OHDA-induced decrease of tyrosine hydroxylase expression in the lesioned striatum. We propose that H. perforatum may counteract the overexpression of dopamine receptors on the lesioned striatum as a possible mechanism for this effect. The present findings provide new evidence that H. perforatum may represent a promising therapeutic tool for PD
Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world
Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic.
Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality.
Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States.
Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis.
Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection
O perfil semiológico do paciente portador de hemorragia digestiva alta
OBJETIVO: O seguinte estudo objetivou descrever a semiologia do paciente portador de hemorragia digestiva alta, considerando como determinante na avaliação de potencias focos hemorrágicos. METODOLOGIA: Foram realizadas buscas nas plataformas do SciELO, LILACS, PubMed, Scopus e Google Scholar,utilizando os descritores gastrointestinal bleeding, peptic ulcerous disease e varicose hemorrhage, sendo identificados 35 estudos, dos quais foram incluídos 13 artigos completos. Desses estudos, 5 avaliaram as principais etiologias, 2 o surgimento de novos testes diagnósticos, 2 analisaram os aspectos epidemiológicos e 1 a sintomatologia apresentada pelo acometimento da hemorragia digestiva alta. Observou-se inicialmente a abundâncias de informações conceituais sobre o sangramento, como um transtorno clínico comum, acompanhada de inúmeras manifestações, considerando que o foco hemorrágico pode ocorrer em qualquer porção do trato gastrointestinal. Neste estudo, todas as publicações eleitas apresentaram o quadro semiológico composto por algia abdominal, indícios de choque hipovolêmico e taquicardia, alguns exibiram quedas abruptas da pressão arterial, odinofagia, êmese, náuseas e estado ictérico. Os pacientes implicados, cronicamente, já manifestaram ocorrências prévias, devido ao caráter recidivante torna-se essencial investigar a existência de varizes, fístula aorto-entérica, angiodisplasia e doença ulcerosa. CONCLUSÃO: Elucida-se que a hemorragia digestiva alta representa a principal causa de sangramento do trato gastrointestinal, majoritamente manifesta-se como hematêmese ou melena e cursam com o quadro sintomatológico que auxilia na avaliação da gravidade deste e o embasamento de potenciais focos de sangramento e que contribuam para disseminação de informações e intervenções futuras
BacHBerry: BACterial Hosts for production of Bioactive phenolics from bERRY fruits
BACterial Hosts for production of Bioactive phenolics from bERRY fruits (BacHBerry) was a 3-year project funded by the Seventh Framework Programme (FP7) of the European Union that ran between November 2013 and October 2016. The overall aim of the project was to establish a sustainable and economically-feasible strategy for the production of novel high-value phenolic compounds isolated from berry fruits using bacterial platforms. The project aimed at covering all stages of the discovery and pre-commercialization process, including berry collection, screening and characterization of their bioactive components, identification and functional characterization of the corresponding biosynthetic pathways, and construction of Gram-positive bacterial cell factories producing phenolic compounds. Further activities included optimization of polyphenol extraction methods from bacterial cultures, scale-up of production by fermentation up to pilot scale, as well as societal and economic analyses of the processes. This review article summarizes some of the key findings obtained throughout the duration of the project
Measurement of the CKM angle in and decays with
A measurement of -violating observables is performed using the decays
and , where the meson is
reconstructed in one of the self-conjugate three-body final states and (commonly denoted ). The decays are analysed in bins of the -decay phase space, leading
to a measurement that is independent of the modelling of the -decay
amplitude. The observables are interpreted in terms of the CKM angle .
Using a data sample corresponding to an integrated luminosity of
collected in proton-proton collisions at centre-of-mass
energies of , , and with the LHCb experiment,
is measured to be . The hadronic
parameters , , , and ,
which are the ratios and strong-phase differences of the suppressed and
favoured decays, are also reported
Caracterização neuroquímica e comportamental da lesão da via nigroestrial com 1 - metil - 4fenil - 1,2,3,6 - tetraidropiridina (MPTP) e 6 - hidroxidopamina (6-OHDA) em ratos /
Orientador : Claudio da CunhaTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Bioquímica. Defesa: Curitiba, 2007Inclui bibliografi
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