265 research outputs found
Contribution of residential wood combustion to PM10 levels in Portugal
Wood is commonly used in residential combustion for heating purposes; however, it can be a major source of air pollutants, namely fine particles, volatile organic compounds and carbon monoxide. Since 2004, the PM10 daily limit value has been surpassed in Portugal, and the European Commission has stated that plans and programs must be designed in order to reduce these levels. In Portugal, 18% of PM10 emissions are due to residential wood combustion, which may deeply impact the PM10 levels in the atmosphere. The main aim of this study is to investigate the impact of residential wood combustion on the air quality in Portugal. The air quality modelling system MM5/CHIMERE was applied over Portugal for a winter month, for the following three scenarios: the reference scenario, considering the actual emissions of PM10; scenario 1, where residential wood combustion emissions are not considered; and scenario 2, which takes into account a complete conversion from traditional fireplaces to certified appliances (with a 90% reduction in PM emissions). The residential wood combustion contribution to PM10 air quality concentration values during January 2007 ranges from 0 to 14 μg m−3, with a mean contribution of 10 μg m−3 in the Lisboa area and 6 μg m−3 in the Porto region. Concerning the legislated values, the area where the daily average limit value (50 μg m−3) is exceeded decreases by 46% in the simulation when residential combustion is not considered. The modelling results for scenario 2 are not significantly different from those for scenario 1. In summary, the regulation of the residential wood combustion sector is as an effective way to reduce the PM10 levels in the atmosphere as regards air quality plans and programs
Air Quality Plans for the Northern Region of Portugal: Improving Particulate Matter and Coping with Legislation
Infantile Refsum Disease: Influence of Dietary Treatment on Plasma Phytanic Acid Levels
Infantile Refsum disease (IRD) is one of the less severe of Zellweger spectrum disorders (ZSDs), a group of peroxisomal biogenesis disorders resulting from a generalized peroxisomal function impairment. Increased plasma levels of very long chain fatty acids (VLCFA) and phytanic acid are biomarkers used in IRD diagnosis. Furthermore, an increased plasma level of phytanic acid is known to be associated with neurologic damage. Treatment of IRD is symptomatic and multidisciplinary.The authors report a 3-year-old child, born from consanguineous parents, who presented with developmental delay, retinitis pigmentosa, sensorineural deafness and craniofacial dysmorphisms. While the relative level of plasma C26:0 was slightly increased, other VLCFA were normal. Thus, a detailed characterization of the phenotype was essential to point to a ZSD. Repeatedly increased levels of plasma VLCFA, along with phytanic acid and pristanic acid, deficient dihydroxyacetone phosphate acyltransferase activity in fibroblasts and identification of the homozygous pathogenic mutation c.2528G>A (p.Gly843Asp) in the PEX1 gene, confirmed this diagnosis. Nutritional advice and follow-up was proposed aiming phytanic acid dietary intake reduction. During dietary treatment, plasma levels of phytanic acid decreased to normal, and the patient's development evaluation showed slow progressive acquisition of new competences.This case report highlights the relevance of considering a ZSD in any child with developmental delay who manifests hearing and visual impairment and of performing a systematic biochemical investigation, when plasma VLCFA are mildly increased. During dietary intervention, a biochemical improvement was observed, and the long-term clinical effect of this approach needs to be evaluated.info:eu-repo/semantics/publishedVersio
Impairment of Adenosinergic System in Rett syndrome: Novel Therapeutic Target to Boost BDNF Signalling
Rett syndrome (RTT; OMIM#312750) is mainly caused by mutations in the X-linked MECP2 gene (methyl-CpG-binding protein 2 gene; OMIM*300005), which leads to impairments in the brain-derived neurotrophic factor (BDNF) signalling. The boost of BDNF mediated effects would be a significant breakthrough but it has been hampered by the difficulty to administer BDNF to the central nervous system. Adenosine, an endogenous neuromodulator, may accomplish that role since through A2AR it potentiates BDNF synaptic actions in healthy animals. We thus characterized several hallmarks of the adenosinergic and BDNF signalling in RTT and explored whether A2AR activation could boost BDNF actions. For this study, the RTT animal model, the Mecp2 knockout (Mecp2-/y) (B6.129P2 (C)-Mecp2tm1.1Bird/J) mouse was used. Whenever possible, parallel data was also obtained from post-mortem brain samples from one RTT patient. Ex vivo extracellular recordings of field excitatory post-synaptic potentials in CA1 hippocampal area were performed to evaluate synaptic transmission and long-term potentiation (LTP). RT-PCR was used to assess mRNA levels and Western Blot or radioligand binding assays were performed to evaluate protein levels. Changes in cortical and hippocampal adenosine content were assessed by liquid chromatography with diode array detection (LC/DAD). Hippocampal ex vivo experiments revealed that the facilitatory actions of BDNF upon LTP is absent in Mecp2-/y mice and that TrkB full-length (TrkB-FL) receptor levels are significantly decreased. Extracts of the hippocampus and cortex of Mecp2-/y mice revealed less adenosine amount as well as less A2AR protein levels when compared to WT littermates, which may partially explain the deficits in adenosinergic tonus in these animals. Remarkably, the lack of BDNF effect on hippocampal LTP in Mecp2-/y mice was overcome by selective activation of A2AR with CGS21680. Overall, in Mecp2-/y mice there is an impairment on adenosinergic system and BDNF signalling. These findings set the stage for adenosine-based pharmacological therapeutic strategies for RTT, highlighting A2AR as a therapeutic target in this devastating pathology.info:eu-repo/semantics/publishedVersio
Recommendations for perioperative prophylaxis of venous thromboembolism in the adult patient. National multidisciplinary consensus 2014
O propósito destas recomendações é fornecer uma ferramenta fundamentada na evidência
científica atual, centrada no doente, que possa ser útil na prática clínica e que contribua para
a implementação adequada, sistemática e transversal da profilaxia do tromboembolismo
venoso no doente adulto. Foram aprovadas, com o apoio da Sociedade Portuguesa de
Anestesiologia, por Consenso Nacional Multidisciplinar entre as especialidades de:
Anestesiologia, Cardiologia; Cirurgia Cardiotorácica; Cirurgia Geral - Cirurgia da Obesidade;
Cirurgia Plástica, Reconstrutiva e Estética; Cirurgia Vascular; Ginecologia e Obstetrícia;
Imuno-Hemoterapia; Neurocirurgia; Oncologia; Ortopedia e Urologia.
O tromboembolismo venoso constitui um grave problema de saúde pública. No período
peri-operatório o risco de tromboembolismo está relacionado com fatores individuais
do doente, tipo de cirurgia e de anestesia e tempo de internamento. Trombose venosa
prévia, doença oncológica, idade avançada, cirurgia major ortopédica, cirurgia bariátrica
e imobilização no leito, constituem alguns dos principais fatores de risco de eventos
tromboembólicos. O bloqueio do neuro-eixo está associado a redução destes eventos.
O estudo ENDORSE que avaliou o cumprimento internacional das recomendações do 7º
Consenso do American College of Chest Physicians sobre profilaxia do tromboembolismo
venoso, revelou que em Portugal a taxa de profilaxia adequada no doente cirúrgico em
risco era inferior à de outros países europeus. Neste estudo, alguns dos doentes a quem
foi prescrita tromboprofilaxia não preenchiam critérios de indicação, ficando expostos a
riscos desnecessários. Os hiatos identificados na profilaxia do tromboembolismo venoso
relacionam-se com a falta de comunicação interdisciplinar efetiva, desconhecimento das
recomendações e da farmacologia dos agentes e o receio de complicações hemorrágicas.
A falta de modelos de avaliação de risco validados e fáceis de aplicar tem dificultado a
uniformização de critérios. Estas recomendações consideram o modelo de avaliação de
risco de Caprini.
A avaliação do risco de tromboembolismo venoso está indicada em todos os doentes
propostos para cirurgia, devendo ser registada no processo clínico. A tromboprofilaxia
é uma responsabilidade multidisciplinar, deve basear-se na ponderação dos riscos de
tromboembolismo venoso e de hemorragia e ter em conta os valores e preferências do
doente.
A tromboprofilaxia deve iniciar-se 6-12 horas após a cirurgia (com exceções)
Expressão relativa do gene ovu em vários estádios de desenvolvimento de botão floral de algodoeiro.
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