2,785 research outputs found

    Preconditioning triggered by carbon monoxide (CO) provides neuronal protection following perinatal hypoxia-ischemia

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    Perinatal hypoxia-ischemia is a major cause of acute mortality in newborns and cognitive and motor impairments in children. Cerebral hypoxia-ischemia leads to excitotoxicity and necrotic and apoptotic cell death, in which mitochondria play a major role. Increased resistance against major damage can be achieved by preconditioning triggered by subtle insults. CO, a toxic molecule that is also generated endogenously, may have a role in preconditioning as low doses can protect against inflammation and apoptosis. In this study, the role of CO-induced preconditioning on neurons was addressed in vitro and in vivo. The effect of 1 h of CO treatment on neuronal death (plasmatic membrane permeabilization and chromatin condensation) and bcl-2 expression was studied in cerebellar granule cells undergoing to glutamate-induced apoptosis. CO's role was studied in vivo in the Rice-Vannucci model of neonatal hypoxia-ischemia (common carotid artery ligature +75 min at 8% oxygen). Apoptotic cells, assessed by Nissl staining were counted with a stereological approach and cleaved caspase 3-positive profiles in the hippocampus were assessed. Apoptotic hallmarks were analyzed in hippocampal extracts by Western Blot. CO inhibited excitotoxicity-induced cell death and increased Bcl-2 mRNA in primary cultures of neurons. In vivo, CO prevented hypoxia-ischemia induced apoptosis in the hippocampus, limited cytochrome c released from mitochondria and reduced activation of caspase-3. Still, Bcl-2 protein levels were higher in hippocampus of CO pre-treated rat pups. Our results show that CO preconditioning elicits a molecular cascade that limits neuronal apoptosis. This could represent an innovative therapeutic strategy for high-risk cerebral hypoxia-ischemia patients, in particular neonates

    1-Benzyl-2,5-dioxopyrrolidine-3,4-diyl diacetate

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    The pyrrolidine-2,5-dione ring in the title compound, C15H15NO6, is in a twisted conformation with the acetyl C atoms projecting to opposite sides of the ring. The acetyl groups lie to opposite sides of the five-membered ring. The benzene ring is roughly perpendicular to the heterocyclic ring, forming a dihedral angle of 76.57 (14)° with it. In the crystal, mol­ecules are connected through a network of C—H⋯O and C—H⋯π inter­actions

    AÇÃO COMUNICATIVA E AÇÃO DIALÓGICA: CONTRIBUIÇÕES PARA UMA EDUCAÇÃO LIBERTADORA

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    O presente trabalho tem por objetivo apresentar as idéias deHabermas e Paulo Freire, demonstrando a convergência de ambas no que serefere à emancipação dos sujeitos na sociedade e na educação. Primeiramente,abordar-se-á a construção da Teoria da Ação Comunicativa de Habermas.Em seguida, serão trazidos alguns elementos do pensamento de Paulo Freire.Por fim, far-se-á uma justaposição das idéias de ambos os autores

    Is SAPS 3 better than APACHE II at predicting mortality in critically ill transplant patients?

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    OBJECTIVES: This study compared the accuracy of the Simplified Acute Physiology Score 3 with that of Acute Physiology and Chronic Health Evaluation II at predicting hospital mortality in patients from a transplant intensive care unit. METHOD: A total of 501 patients were enrolled in the study (152 liver transplants, 271 kidney transplants, 54 lung transplants, 24 kidney-pancreas transplants) between May 2006 and January 2007. The Simplified Acute Physiology Score 3 was calculated using the global equation (customized for South America) and the Acute Physiology and Chronic Health Evaluation II score; the scores were calculated within 24 hours of admission. A receiver-operating characteristic curve was generated, and the area under the receiver-operating characteristic curve was calculated to identify the patients at the greatest risk of death according to Simplified Acute Physiology Score 3 and Acute Physiology and Chronic Health Evaluation II scores. The Hosmer-Lemeshow goodness-of-fit test was used for statistically significant results and indicated a difference in performance over deciles. The standardized mortality ratio was used to estimate the overall model performance. RESULTS: The ability of both scores to predict hospital mortality was poor in the liver and renal transplant groups and average in the lung transplant group (area under the receiver-operating characteristic curve = 0.696 for Simplified Acute Physiology Score 3 and 0.670 for Acute Physiology and Chronic Health Evaluation II). The calibration of both scores was poor, even after customizing the Simplified Acute Physiology Score 3 score for South America. CONCLUSIONS: The low predictive accuracy of the Simplified Acute Physiology Score 3 and Acute Physiology and Chronic Health Evaluation II scores does not warrant the use of these scores in critically ill transplant patients

    Nitrogen input by bamboos in neotropical forest: a new perspective

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    Background Nitrogen (N) is an important macronutrient that controls the productivity of ecosystems and biological nitrogen fixation (BNF) is a major source of N in terrestrial systems, particularly tropical forests. Bamboo dominates theses forests, but our knowledge regarding the role of bamboo in ecosystem functioning remains in its infancy. We investigated the importance of a native bamboo species to the N cycle of a Neotropical forest. Methods We selected 100 sample units (100 m2 each) in a pristine montane Atlantic Forest, in Brazil. We counted all the clumps and live culms of Merostachys neesii bamboo and calculated the specific and total leaf area, as well as litter production and respective N content. Potential N input was estimated based on available data on BNF rates for the same bamboo species, whose N input was then contextualized using information on N cycling components in the study area. Results With 4,000 live culms ha−1, the native bamboo may contribute up to 11.7 kg N ha−1 during summer (January to March) and 19.6 kg N ha−1 in winter (July to September). When extrapolated for annual values, M. neesii could contribute more than 60 kg N ha−1y−1. Discussion The bamboo species’ contribution to N input may be due to its abundance (habitat availability for microbial colonization) and the composition of the free-living N fixer community on its leaves (demonstrated in previous studies). Although some N is lost during decomposition, this input could mitigate the N deficit in the Atlantic Forest studied by at least 27%. Our findings suggest that M. neesii closely regulates N input and may better explain the high diversity and carbon stocks in the area. This is the first time that a study has investigated BNF using free-living N fixers on the phyllosphere of bamboo

    Development of New Canned Chub Mackerel Products Incorporating Edible Seaweeds—Influence on the Minerals and Trace Elements Composition

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    This study aimed to develop new canned chub mackerel products incorporating edible seaweeds (Ascophyllum nodosum, Fucus spiralis, Saccorhiza polyschides, Chondrus crispus, Porphyra sp. and Ulva sp.) harvested in the Portuguese North-Central coast, with simultaneous sensory improvement and minerals enrichment. Two processes were compared, namely the addition of seaweeds in i) the canning step and ii) in the brining step (as the replacement for salt). The concentrations of four macrominerals (Na, K, Ca and Mg), chloride, and twelve trace elements (Co, Cu, Fe, I, Li, Mn, Mo, Rb, Se, Sr, V and Zn) were determined by high-resolution continuum source flame atomic absorption spectrometry (HR-CS-FAAS) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. Results showed that canned chub mackerel incorporating C. crispus and F. spiralis was found to be the preferred sensory option, also exhibiting contents enriched with Cl, Co, Cu, Fe, I, Li, Mg, Mn, Mo, Na, Rb, Se, and Sr. This effect was more pronounced when both seaweed species were added to replace the salt added in the brining step.This work received financial support from project iCanSea—Conservas com macroalgas para diferenciação nutricional e sensorial, sponsored by Portugal 2020 under the Programa Operacional Competitividade e Internacionalização (Ref.3171/Portugal 2020). The Fundação para a Ciência e a Tecnologia (FCT) and the FEDER, under Programme PT2020 (Project UID/QUI/50006/2019) and the project Qualidade e Segurança Alimentar—uma abordagem (nano)tecnológica (NORTE-01-0145-FEDER-000011) are also acknowledged for the financial funding.info:eu-repo/semantics/publishedVersio

    Comparative EPR and fluorescence conformational studies of fully active spin-labeled melanotropic peptides

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    Similar to melanocyte stimulating hormone (alpha -MSH), its potent and long-acting analogue, [Nle(4), D-Phe(7)]alpha -MSH, when labeled with the paramagnetic amino acid probe 2,2,6,6-tetramethylpiperidine-N-oxyl-4-amino-4-carboxylic acid (Toac), maintains its full biological potency, thus validating any comparative structural investigations between the two labeled peptides, Correlation times, calculated from tire electron paramagnetic resonance signal of Toac bound to the peptides, and Toac-Trp distances, estimated from the Toac fluorescence quenching of the Trp residue present in the peptides, indicate a more rigid and folded structure for the potent analogue as compared to the hormone, in aqueous medium. (C) 2001 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.Universidade Federal de São Paulo, Dept Biofis, BR-04044020 São Paulo, BrazilUniv São Paulo, Inst Fis, BR-66318 São Paulo, BrazilUniv São Paulo, Inst Biociencias, Dept Fisiol, BR-11176 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biofis, BR-04044020 São Paulo, BrazilWeb of Scienc
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