2,643 research outputs found
Hepatic mitochondrial content in malondialdehyde may be a marker of sea lamprey contact with atrazine
The atrazine attracts special attention as pollutant because of itspersistence in the aquatic environment. Although this herbicide has been studied in teleost, its toxicity in the sea lamprey, Petromyzon marinus is still poorly understood. Oxidative stress may occur if chemical pollutants contribute to block the capacity of mitochondria to generate ATP with continuous production of reactive oxygen species (ROS), disturbing the success of P. marinus seawater acclimation. So, the aim of this study was to evaluate how atrazine influences the malondialdehyde (MDA), glutathione (GSH) and glutathione disulfide (GSSG) contents of gills and liver mitochondria of juveniles from Lima river basin, Portugal during salt acclimation. Sampling occurred at the beginning of the P. marinus downstream migration. The sampled juveniles were transported alive to the laboratory and maintained in 200 l tanks with LSS 8 life support system. Two groups of 40 specimens were hold in tanks with 50 or 100 lg/l atrazine, during 30 days. The salinity was gradually increased from 0 to 35 psu,following a three step procedure during a 30 days period. The control group was maintained in freshwater without atrazine. Mitochondria obtained by centrifugation at 15000 g, 30 min, 4°C, of tissues homogenates prepared in 50 mM Tris-HCl pH 7.5 buffer were used in determination of ROS, MDA, GSH and GSSG by fluorescence. The statistical analysis were performed by ANOVA I and Duncan (p < 0.05), using SPSS 22 for Windows.The results showed that in P. marinus juveniles, no significant changes in the markers of oxidative stress and cell damages were detected in the mitochondrial gills. Nevertheless, in the animals exposed to 50 lg/l atrazine the content in glutathione and GSSG increased. A similar pattern of stress markers was detected in hepatic mitochondria. However, in the presence of atrazine, the MDA level of the mitochondria of liver increased threefold in the animals during salt acclimation. The high level of mitochondrial damages, detected in the hepatic mitochondria of macrophthalmia treated with atrazine, suggests that herbicide exposure caused metabolic failures which can disturb the adaptation of these specimens to the oceanic feeding phase. The hepatic mitochondrial MDA levels of P. marinus, may eventually detect sea lamprey contact with chlorine herbicides
L\'evy flights of photons in hot atomic vapours
Properties of random and fluctuating systems are often studied through the
use of Gaussian distributions. However, in a number of situations, rare events
have drastic consequences, which can not be explained by Gaussian statistics.
Considerable efforts have thus been devoted to the study of non Gaussian
fluctuations such as L\'evy statistics, generalizing the standard description
of random walks. Unfortunately only macroscopic signatures, obtained by
averaging over many random steps, are usually observed in physical systems. We
present experimental results investigating the elementary process of anomalous
diffusion of photons in hot atomic vapours. We measure the step size
distribution of the random walk and show that it follows a power law
characteristic of L\'evy flights.Comment: This final version is identical to the one published in Nature
Physic
Can the mitochondrial malondialdehyde content be an useful tool to distinguish ecological quality of Petromyzon marinus habitat?
The sea lamprey is an anadromous species that migrates twice during its life cycle between freshwater and seawater. Microphagous larvae generally spend 4–5 years burrowed in the substrate of rivers and streams before undergoing metamorphosis that ends with the beginning of the juvenile trophic migration. Once metamorphosis is complete, sea lamprey juvenile downstream migrants are fully tolerant to 35 PSU seawater. Pollution resulting from industrial effluents may disturb the seawater acclimatization causing oxidative damages, and ultimately may lead to a decrease of sea lamprey population. The aim of this study was to compare salt acclimation of sea lamprey juveniles captured in river basins with different levels of aquatic pollution, using mitochondrial glutathione and malondialdehyde of gills and liver as markers of physiological stress and cell damages. The results showed that juveniles from Lima basin exhibited the highest levels of mitochondrial malondialdehyde in gills, even though significant changes in the stress markers of mitochondrial gills of all animals subject to salt acclimation were not detected. In addition, an increase in the oxidative damages of hepatic mitochondria of macrophthalmia from Vouga basin suggests the occurrence of metabolic failures with the potential to disturb the capacity to adaptation to the marine environment
Formação em serviço: impacto de novas estratégias
A formação em enfermagem contribui para o desenvolvimento de competências
cognitivas e técnicas, mas também relacionais que possam ser transferíveis para o
contexto de trabalho pelo que se deve privilegiar a formação em serviço como forma
de manter actualizados, aprofundar e desenvolver os conhecimentos adquiridos.
Faz parte do descritivo de funções do enfermeiro e consta dos seus princípios
orientadores da prática, a constante actualização através da formação. (ver OE ….)
Identificada a irregular e reduzida formação interna que ocorre no serviço (obrigatória
ou não), a par de identificação de lacunas em temas fulcrais, foi implementada no
serviço de Cardiologia do Hospital Fernando Fonseca E.P.E. múltiplas estratégias de
intervenção que visem o desenvolvimento profissional dos enfermeiros e auxiliares de
acção médica através do aumento da formação na sua globalidade. A diversas
estratégias preconizadas consistem na contabilização das horas de formação como
horas de serviço, inscrição dos formandos para as formações com disponibilização do
dia expresso em horário, possibilidade de negociação de objectivos para as avaliações
de desempenho anuais, existência de um cronograma anual, de um Manual do
Formador como guia orientador à prática formativa, abordagem de diferentes áreas
focado nas necessidades de serviço e também no interesse individual, com
apresentações frequentes e que abranja todos os profissionais, formações semanais
de curta duração a decorrer em passagem de turno, formações mensais de uma hora
em sala de formação, trabalhos disponibilizados a toda a equipa.
Esta etapa formativa decorreu ao longo de todo o ano de 2014, cabendo em fase
posterior, a sua análise e avaliação, com base em indicadores de formação em serviço,
como sendo indicadores de execução como a taxa de número de horas de formação e
taxa de número de acções de formação, acrescida da avaliação de satisfação individual
dos participantes e suas opiniões face às estratégias implementadas, através da
realização de questionários aos mesmos. Acresce a avaliação da variação de adesão à
formação não obrigatória face às formações disponibilizadas, comparativamente com
as obrigatórias realizadas face à totalidade de formação obrigatórias. A análise dos referidos dados, revelam-nos uma percentagem significativa de acções
de formação ocorridas, assim como elevado número de horas formativas, pelo que
sugere um método eficaz de acção.
Uma análise preliminar revela satisfação e interesse equiparados às taxas formativas.
Daqui se poderá depreender que o conjunto de estratégias implementadas veio ao
encontro dos objectivos estabelecidos.
Cabe, em fase posterior, a análise do impacto formativo na melhoria das práticas,
eventualmente com base em indicadores adequados a cada formação,
complementada com os dados trimestrais das auditorias aos cuidados de enfermagem
do HFF
Expression and clinical relevance of SOX9 in gastric cancer
Gastric cancer is one of the most frequent tumours and the third leading cause of cancer-related death worldwide. The investigation of new biomarkers that can predict patient outcome more accurately and allow better treatment and follow-up decisions is of crucial importance. SOX9 (sex-determining region Y (SRY)-box 9) is a regulator of cell fate decisions in embryogenesis and adulthood. Here, we sought to ascertain the relevance of SOX9 transcription factor as a prognostic marker in gastric cancer. SOX9 expression was analyzed by immunohistochemistry in 333 gastric adenocarcinoma cases, and its association with clinicopathological and follow-up data was evaluated. SOX9 nuclear expression was absent in 17% of gastric cancer cases and predicted worse disease-free survival (P = 0 03). SOX9 expression was associated with lower risk of relapse in Cox univariable analysis (HR = 0 58; 95% CI = 0 35-0.97; P = 0 04). The prognostic value of SOX9 was more pronounced in tumours with expansive growth (P = 0 01) or with venous invasion (P = 0 02). Two validation cohorts from the Cancer Genome Atlas (TCGA) and the Asian Cancer Research Group (ACRG) confirmed that low SOX9 expression was significantly associated with poor patient outcome. In conclusion, we have identified SOX9 as a biomarker of disease relapse in gastric cancer patients. Further experiments are needed to elucidate its biological relevance at the cellular level.The authors wish to acknowledge the tumour and tissue bank at Hospital de São João for providing all the means to collect the human tissue samples included in this study. This work was supported by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT—Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Inovação in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274). This work was also financed by the projects NORTE-01-0145-FEDER-000003 (DOCnet) and NORTE-07-0124-FEDER-000029 supported by Norte Portugal Regional Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). BP and RB acknowledge FCT for financial support (grants SFRH/BPD/109794/2015 and SFRH/BPD/68276/2010, respectively)
Orofacial Injuries in Children and Adolescents (2009-2013): A 5-Year Study In Porto, Portugal
The aim of this study was to verify the prevalence of acts of aggression to the head, face and neck towards victims of Physical Violence against Children and Adolescents (PVCA) who were examined at the National Institute of Legal Medicine and Forensic Sciences Delegation North (INMLCF-DN) in Porto, Portugal. A study was carried out on 2,148 complaints of physical aggression against children and adolescents (0 to less than 18 years old) occurred between 2009 and 2013 and which were retrieved from information about violence held on INMLCF-DN data files. Continuous variables were described and the association between them was verified by Chi-square or Fischer’s Exact tests with 5% significance level. Within the 5-year timespan, 1,380 cases were identified with clinical relation with physical aggression. Most subjects evaluated were male adolescents and the most affected body region was the face, to which 747 injuries (24.7%) were recorded, with statistically significant association between sex and region (head and face). Victims in 15-17-year-old age group are more susceptible to violence than those in the 0-14-year-old age range. Dentists routinely examine the face, neck and skull, which make them the most appropriate health professionals to identify cases of aggression early.The authors thank the INMLCF-DN (Instituto Nacional de Medicina Legal e Ciências Forenses - Delegação do Norte, Portugal) for technical support and CAPES(Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brazil) for scholarship
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