Synthesis of Unstable Cyclic Peroxides for Chemiluminescence Studies

Cyclic four-membered ring peroxides are important high-energy intermediates in a variety of chemi and bioluminescence transformations. Specifically, alpha-peroxylactones (1,2-dioxetanones) have been considered as model systems for efficient firefly bioluminescence. However, the preparation of such highly unstable compounds is extremely difficult and, therefore, only few research groups have been able to study the properties of these substances. In this study, the synthesis, purification and characterization of three 1,2-dioxetanones are reported and a detailed procedure for the known synthesis of diphenoyl peroxide, another important model compound for the chemical generation of electronically excited states, is provided. For most of these peroxides, the complete spectroscopic characterization is reported here for the first time.

Development and validation of a high-performance liquid chromatography method for quantification of egonol and homoegonol in Styrax species

Styrax camporum Pohl, known in Brazil as estoraque do campo or cuia de brejo, has been used in the treatment of gastrointestinal diseases. The therapeutic action of S. camporum has been attributed to the ethyl acetate fraction, although the chemical composition of this fraction has not yet been analyzed. In this study, a high-performance liquid chromatography photodiode array detection (HPLC-PAD) method for analysis of Brazilian Styrax species has been developed. The compounds egonol (1) and homoegonol (2) were found to be present in all the samples investigated by HPLC. These compounds were isolated by open column chromatography followed by preparative TLC, and were identified by 1H NMR. Compounds 1 and 2 were thus proposed as phytochemical markers for Styrax, owing to their biological properties and presence in other Styrax species. The developed method has been validated and successfully applied for quantification of 1 and 2 in S. camporum dried leaves and crude ethanolic extracts from S. ferrugineus and S. pohlii aerial parts. Copyright (c) 2011 John Wiley & Sons, Ltd.

Inheritance of resistance to anthracnose stalk rot (Colletotrichum graminicola) in tropical maize inbred lines

Generation means was used to study the mode of inheritance of resistance to anthracnose stalk rot in tropical maize. Each population was comprised of six generations in two trials under a randomized block design. Inoculations were performed using a suspension of 105 conidia mL(-1) applied into the stalk. Internal lesion length was directly measured by opening the stalk thirty days after inoculation. Results indicated contrasting modes of inheritance. In one population, dominant gene effects predominated. Besides, additive x dominant and additive x additive interactions were also found. Intermediate values of heritability indicated a complex resistance inheritance probably conditioned by several genes of small effects. An additive-dominant genetic model sufficed to explain the variation in the second population, where additive gene effects predominated. Few genes of major effects control disease resistance in this cross. Heterosis widely differed between populations, which can be attributed to the genetic background of the parental resistant lines.

Protein quality control disruption by PKC beta II in heart failure: rescue by the selective PKC beta II inhibitor, beta IIV5-3

Myocardial remodeling and heart failure (HF) are common sequelae of many forms of cardiovascular disease and a leading cause of mortality worldwide. Accumulation of damaged cardiac proteins in heart failure has been described. However, how protein quality control (PQC) is regulated and its contribution to HF development are not known. Here, we describe a novel role for activated protein kinase C isoform beta II (PKC beta II) in disrupting PQC. We show that active PKC beta II directly phosphorylated the proteasome and inhibited proteasomal activity in vitro and in cultured neonatal cardiomyocytes. Importantly, inhibition of PKC beta II, using a selective PKC beta II peptide inhibitor (beta IIV5-3), improved proteasomal activity and conferred protection in cultured neonatal cardiomyocytes. We also show that sustained inhibition of PKC beta II increased proteasomal activity, decreased accumulation of damaged and misfolded proteins and increased animal survival in two rat models of HF. Interestingly, beta IIV5-3-mediated protection was blunted by sustained proteasomal inhibition in HF. Finally, increased cardiac PKC beta II activity and accumulation of misfolded proteins associated with decreased proteasomal function were found also in remodeled and failing human hearts, indicating a potential clinical relevance of our findings. Together, our data highlights PKC beta II as a novel inhibitor of proteasomal function. PQC disruption by increased PKC beta II activity in vivo appears to contribute to the pathophysiology of heart failure, suggesting that PKC beta II inhibition may benefit patients with heart failure. (218 words)

NADPH Oxidase and Neurodegeneration

NADPH oxidase (Nox) is a unique, multi-protein, electron transport system that produces large amounts of superoxide via the reduction of molecular oxygen. Nox-derived reactive oxygen species (ROS) are known to be involved in a variety of physiological processes, including host defense and signal transduction. However, over the past decade, the involvement of (Nox)-dependent oxidative stress in the pathophysiology of several neurodegenerative diseases has been increasingly recognized. ROS produced by Nox proteins contribute to neurodegenerative diseases through distinct mechanisms, such as oxidation of DNA, proteins, lipids, amino acids and metals, in addition to activation of redox-sensitive signaling pathways. In this review, we discuss the recent literature on Nox involvement in neurodegeneration, focusing on Parkinson and Alzheimer diseases.

Eye enucleation activates the transcription nuclear factor kappa-B in the rat superior colliculus

Ocular enucleation produces significant morphological and physiological changes in central visual areas. However, our knowledge of the molecular events resulting from eye enucleation in visual brain areas remains elusive. We characterized here the transcription nuclear factor kappa-B (NF-kappa B) activation induced by ocular enucleation in the rat superior colliculus (SC). We also tested the effectiveness of the synthetic glucocorticoid dexamethasone in inhibiting its activation. Electrophoretic mobility shift assays to detect NF-kappa B indicated that this transcription factor is activated in the SC from 1 h to day 15 postlesion. The expression of p65 and p50 proteins in the nuclear extracts was also increased. Dexamethasone treatment was able to significantly inhibit NF-kappa B activation. These findings suggest that this transcriptional factor is importantly involved in the visual system short-term processes that ensue after retinal lesions in the adult brain. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

EVALUATION OF GLUTATHIONE S-TRANSFERASE GSTM1 AND GSTT1 POLYMORPHISMS AND METHYLMERCURY METABOLISM IN AN EXPOSED AMAZON POPULATION

Over the last decades, the presence of methylmercury (MeHg) in the Amazon region of Brazil and its adverse human health effects have given rise to much concern. The biotransformation of MeHg occurs mainly through glutathione (GSH) in the bile mediated by conjugation with glutathione S-transferases (GST). Epidemiological evidence has shown that genetic polymorphisms may affect the metabolism of MeHg. The aim of this study was to evaluate the association between GST polymorphisms, GSH, and Hg levels in blood (B-Hg) and in hair (H-Hg) of an Amazon population chronically exposed to the metal through fish consumption. Blood and hair samples were collected from 144 volunteers (71 men, 73 women). B-Hg and H-Hg levels were determined by inductively coupled plasma-mass spectrometry, and GSH levels were evaluated by a spectrophotometric method. GSTM1 and T1 genotyping evaluation were carried out by multiplex polymerase chain reaction (PCR). Mean levels of B-Hg and H-Hg were 37.7 +/- 24.5 mu g/L and 10.4 +/- 7.4 mu g/g, respectively; GSH concentrations ranged from 0.52 to 2.89 mu M/ml of total blood. Distributions for GSTM1/T1, GSTM1/GSTT1*0, GSTM1*0/T1, and GSTM1*0/GSTT1*0 genotypes were 35.4, 22.2, 25.0, and 17.4%, respectively. GSTT1 genotype carriers presented lower levels of B-Hg and H-Hg when compared to other genotypes carriers. In addition, GSTM1*0/GSTT1*0 individuals presented higher Hg levels in blood and hair than subjects presenting any other genotypes. There appeared to be no evidence of an effect of polymorphisms on GSH levels. Therefore, our data suggest that GST polymorphisms may be associated with MeHg detoxification.

Dihydrocinnamic acid derivatives from Hortia species and their chemotaxonomic value in the Rutaceae

Phytochemical studies of Hortia brasiliana and Hortia oreadica (Rutaceae) have led to the identification of three novel dihydrocinnamic acids: 5-methoxy-2,2-dimethyl-2H-1-benzopyran-8-propanoic acid, 5,6-dimethoxy-2,2-dimethyl-2H-1-benzopyran-8-propanoic acid and erythro-2-hydroxy-4-methoxy-3-(1,2,3-trihydroxy-3-methylbutyl) benzenepropanoic acid from H. brasiliana and the second compound and six known dihydrocinnamic acids from H. oreadica. Engler included Hortia as the single Neotropical genus in the Toddalioideae subtribe Toddaliinae. However, the range of dihydrocinnamic acid derivatives found in H. brasiliana and H. oreadica show that they contain similar compounds to other species of Hortia and clearly point to their phytochemical affinities with other Rutoideae species. (C) 2012 Elsevier Ltd. All rights reserved.

Antigenotoxic Effects of Piquia (Caryocar villosum) in Multiple Rat Organs

This study investigated the in vivo genotoxicity of piquia pulp (Caryocar villosum) and its potential antigenotoxicity on doxorubicin (DXR)-induced DNA damage by comet assay and micronucleus test. In addition, the phytochemicals present in piquia pulp were determined. Piquia fruit pulp (75, 150 or 300 mg/kg b.w.) was administered by gavage to Wistar rats for 14 days, and the animals received an injection of saline or DXR (15 mg/kg b.w., i.p.) 24 h before they were euthanized. The phytochemical analysis revealed the presence of carotenoids; phenolic compounds, including flavonoids; tannins and alpha-tocopherol in piquia pulp. No statistically significant differences were observed in the evaluated parameters, demonstrating the absence of cytotoxic and genotoxic effects of piquia pulp at all tested doses. In liver, kidney, cardiac and bone marrow cells, piquia significantly reduced the DNA damage induced by DXR. Our results showed that the lowest piquia dose caused the largest decrease in DNA damage and the highest dose caused the smallest decrease, demonstrating an inverse dose-response of piquia pulp. Furthermore, we observed a difference in the potential antigenotoxic effects in several tissues. In conclusion, our results demonstrated that piquia pulp was not genotoxic and inhibited the genotoxicity induced by DXR, but some of the protective effects that were observed depended on the doses and experimental conditions. Therefore, further investigations are needed to clarify how piquia pulp positively affects human health.

Effect of Cholecalciferol as Adjunctive Therapy With Insulin on Protective Immunologic Profile and Decline of Residual beta-Cell Function in New-Onset Type 1 Diabetes Mellitus

Objective: To evaluate the effect of vitamin D-3 on cytokine levels, regulatory T cells, and residual beta-cell function decline when cholecalciferol (vitamin D-3 administered therapeutically) is given as adjunctive therapy with insulin in new-onset type 1 diabetes mellitus (T1DM). Design and Setting: An 18-month (March 10, 2006, to October 28, 2010) randomized, double-blind, placebo-controlled trial was conducted at the Diabetes Center of Sao Paulo Federal University, Sao Paulo, Brazil. Participants: Thirty-eight patients with new-onset T1DM with fasting serum C-peptide levels greater than or equal to 0.6 ng/mL were randomly assigned to receive daily oral therapy of cholecalciferol, 2000 IU, or placebo. Main Outcome Measure: Levels of proinflammatory and anti-inflammatory cytokines, chemokines, regulatory T cells, hemoglobin A(1c), and C-peptide; body mass index; and insulin daily dose. Results: Mean (SD) chemokine ligand 2 (monocyte chemoattractant protein 1) levels were significantly higher (184.6 [101.1] vs 121.4 [55.8] pg/mL) at 12 months, as well as the increase in regulatory T-cell percentage (4.55%[1.5%] vs 3.34%[1.8%]) with cholecalciferol vs placebo. The cumulative incidence of progression to undetectable (<= 0.1 ng/mL) fasting C-peptide reached 18.7% in the cholecalciferol group and 62.5% in the placebo group; stimulated C-peptide reached 6.2% in the cholecalciferol group and 37.5% in the placebo group at 18 months. Body mass index, hemoglobin A(1c) level, and insulin requirements were similar between the 2 groups. Conclusions: Cholecalciferol used as adjunctive therapy with insulin is safe and associated with a protective immunologic effect and slow decline of residual beta-cell function in patients with new-onset T1DM. Cholecalciferol may be an interesting adjuvant in T1DM prevention trials.

Bixin and norbixin protect against DNA-damage and alterations of redox status induced by methylmercury exposure in vivo

Populations in the Amazon are exposed to organic mercury via consumption of contaminated foods. These ethnic groups consume a specific plant seed annatto which contains certain carotenoids. The aim of this study was to find out if these compounds (bixin, BIX and norbixin, NOR), protect against DNA-damage caused by the metal. Therefore, rats were treated orally with methylmercury (MeHg) and with the carotenoids under conditions that are relevant to humans. The animals were treated either with MeHg (30 mu g/kg/bw/day), BIX (0.110 mg/kg/bw/day), NOR (0.011.0 mg/kg/bw/day) or combinations of the metal compound and the carotenoids consecutively for 45 days. Subsequently, the glutathione levels (GSH) and the activity of catalase were determined, and DNA-damage was measured in hepatocytes and leukocytes using single cell gel electrophoresis assays. Treatment with the metal alone caused a decrease in the GSH levels (35%) and induced DNA damage, which resulted in increased DNA migration after electrophoresis in liver and blood cells, whereas no effects were seen with the carotenoids alone. When BIX or NOR were given in combination with organic mercury, the intermediate and the highest concentrations of the carotenoids (1.0 and 10.0 mg/kg/bw/day BIX and 0.1 and 1.0 mg/kg/bw/day NOR) protected against DNA-damage. Furthermore, we found with both carotenoids, a moderate increase in the GSH levels in both metal-treated and untreated animals, while the activities of catalase remained unchanged. Our results indicate that consumption of BIX and NOR may protect humans against the adverse health effects caused by exposure to organic mercury. Environ. Mol. Mutagen., 2012. (c) 2012 Wiley Periodicals, Inc.

Panorama atual dos repositórios institucionais das instituições de ensino superior no Brasil

O cenário atual de repositórios digitais mundialmente distribuídos estimula estudos diversificados com os quais esse trabalho visa contribuir, objetivando um levantamento dos repositórios de instituições de ensino superior no Brasil, verificando a eficácia de uma ferramenta experimental no tratamento e análise dos dados e usando como fontes os diretórios Registry of Open Access Repositories (ROAR), Directory of Open Access Repositories (OpenDOAR), Diretório Luso-Brasileiro de Periódicos e Repositórios de Acesso Livre e a lista L_repositories. A ferramenta experimental Google Fusion Tables foi aplicada nos dados dos repositórios institucionais pesquisados, categorizando suas principais características: Instituição mantenedora, Natureza da instituição, Local, Região geográfica, Software adotado e sua versão, adoção do padrão Dublin Core e quantidade de trabalhos disponibilizados na data do estudo. Foram identificados 49 repositórios que em agosto de 2013 disponibilizavam 396.881 itens, sendo as instituições federais as com maior povoamento e o repositório LUME o primeiro em volume de itens; a região Sudeste com o maior número de repositórios e volume de itens disponibilizados; o DSpace o software predominante, com maior utilização da versão 1.6.2 e o padrão de metadados Dublin Core em todas as aplicações desse software. Este estudo comprovou a eficácia e utilidade do FusionTables, permitindo caracterizar o panorama atual de repositórios de instituições de ensino superior no Brasil. Os resultados foram disponibilizados em um Catálogo de Repositórios de Instituições de Ensino Superior no Brasil e um Mapa interativo dos Repositórios de Instituições de Ensino Superior no Brasil.

O sistema PBL, problem-based learning, no ensino de medicina no Brasil : análise bibliográfica sobre a sua execução

Introdução: Entre as estratégias de ensino e aprendizagem utilizadas nas práticas pedagógicas, a Problem Based Learning (PBL) (Aprendizagem Baseada em Problemas) é utilizada desde 1960, em especial nos cursos de Medicina. Mesmo sendo uma estratégia valiosa, um dos seus obstáculos é a pouca prática dos alunos em atividades autodirigidas, pesquisa e construção coletiva do conhecimento. Objetivo: Rastrear elementos constitutivos da PBL através de dados colhidos em artigos pesquisados em sítios de divulgação científica; Avaliar, nos estudos selecionados, os aspectos positivos e negativos que estejam relacionados com a metodologia do Sistema PBL aplicada ao ensino médico no Brasil. Metodologia: Estudo bibliográfico de 13 textos utilizando um modelo de desconstrução, denominada Análise Textual Discursiva (ATD) que consiste em: transformação dos artigos em pedaços menores; análise textual; identificação de padrões convergentes e divergentes em relação a PBL; organização e síntese dos dados, culminando com a elaboração de estratégia adaptativa da PBL para o curso de Medicina. Resultados: Foram encontradas 116 citações que convergiam para referências positivos acerca da metodologia PBL e 40 citações que divergiam acerca dos pontos positivos. Os aspectos positivos como o desenvolvimento de atitudes e habilidades; desenvolvimento de competências anteriores ao curso; efeitos positivos depois de terminada a graduação, como autonomia de estudo e a articulação entre currículo e realidade profissional, representam pontos a serem reforçados na aula. Em contraponto, foi observado que dentre os negativos a não compreensão do papel do professor como tutor; necessidade de conteúdo formal tradicional pelos alunos e a expectativa que o professor retire as suas dúvidas são pontos a serem evitados. Conclusões: A metodologia PBL deverá servir como metodologia ativa para aproveitar ao máximo as habilidades que os alunos já apresentam, potencializando o aprendizado na educação médica em sala de aula. Palavras-Chave: PBL; curso de medicina; metodologia ativa; educação médica.

AVALIAR POR COMPETÊNCIAS: UMA DISCUSSÃO A PARTIR DO ENSINO PROFISSIONALIZANTE

O objetivo desta investigação é buscar uma melhor compreensão sobre o complexo e polissêmico universo da avaliação por competências no ensino profissionalizante, a partir das definições de competências elencadas na Lei de Diretrizes e Bases da Educação Nacional em vigor (lei nº 9394/96) e outros documentos oficiais posteriores, assim como o referencial teórico advindo dessa discussão, tanto no âmbito da educacional quanto mercadológico, desde os anos 1990. Como, também, os documentos técnicos norteadores da escola de ensino profissionalizante ora investigada. Para compreendermos o presente e o futuro, tornou-se importante a realização de um resgate da evolução desse mesmo ensino, desde a época em que se lecionava com o único intuito de suprir apenas necessidades pontuais da economia, passando pelos liceus de artes e ofícios, nos séculos XVIII e XIX, e o impulso definitivo a partir da 1ª República, com Nilo Peçanha. Mesmo assim, verificou-se, a partir do arcabouço teórico utilizado, que certos aspectos continuaram presentes, mesmo após séculos de história, como a forte discriminação em relação a esse mesmo ensino profissionalizante, a conotação assistencialista e a dualidade do ensino no Brasil, onde a visão prevalecente foi a de que o ensino profissionalizante era destinado aos mais pobres e, o ensino regular, à elite. Avaliar competências tornou-se ainda mais importante a partir da aceleração da globalização e das profundas transformações do mercado de trabalho mundial, que passaram a exigir da mão de obra não só as habilidades anteriormente concebidas para realizar um trabalho específico ou desempenhar uma função. Mas, ir além do saber fazer, e passar a executar o saber ser (Kuenzer, 2002) de maneira sistemática, no dia a dia. Como, por exemplo, aprender e saber transformar conhecimentos, aptidões, habilidades, interesses e vontade em resultados práticos (Resende, 2000), não só no Brasil. Acompanhamos também os esforços de adequação do ensino profissionalizante em outros países, tais como EUA, França, Grã-Bretanha, e de organizações, como Unesco e a OCDE. Assim, o sujeito passa ser remunerado pelas suas novas capacidades e desempenho, e não mais apenas pelo cargo de ocupa (Arruda, 2000). Essas questões tornaram-se um grande problema, real, do cotidiano, e com um sentido de urgência que merece ser investigado, por sua relevância e atualidade. Nesse sentido, o presente trabalho discute essas questões a partir do olhar de quem, efetivamente, avalia por esse sistema, que são os docentes do ensino profissionalizante, que lidam no cotidiano com essa complexidade, considerando-se inclusive o contexto em que atuam e o senso comum. Como resultado, observa-se que a avaliação por competências encontrou o seu espaço como um sistema de análise de resultados e práticas, de forma a acompanhar os alunos sistematicamente e não apenas ao final dos estudos.

Concepções de interdisciplinaridade: o Programa Ensino Médio Inovador

The Interdisciplinary practice opens in the context of Basic Education guiding new looks in the production of knowledge. It is necessary to reflect the interdisciplinarity as scientific and epistemological stance and its conditions of possibility of expanding the horizon before the theoretical and methodological challenges posed by modernity. Thus, this work aimed to analyze interdisciplinary concepts present in the proposal of the High School Program Innovator. Therefore, the theoretical route initially had the search for understanding of high school in Brazil, interdisciplinarity as the possibility of tensioning the production of scientific knowledge, mainly anchored in the studies of Acácia Kuenzer, Dermeval Saviani, Boaventura de Sousa Santos, Claude Raynaut, Henrique Leff and Edgar Morin. The study was methodological subsidy document research and principles of content analysis. The analysis took place from the seven documents that make up the construction path of High School Program Innovator and a semi-structured interview. So, we sought to understand the concepts of the documents establishing analytical categories from more evoked content. In this process identified three categories with regard to the construction of the Program proposal: pedagogical innovations, curriculum organization and teaching quality and three categories with regard to interdisciplinary concepts present in the program: dialogue between curriculum components, joint knowledge and role of high school students. From the studies it was observed that the program came up with the prospect of directing a new identity for the final stage of basic education, listing Documents Guiding Plans and actions for a new curricular organization of secondary education. It was noted that the Program, though explicit in its guiding documents of the interdisciplinary perspective, in no time he calls himself as interdisciplinary. Interdisciplinary actions should run or from school understanding, as well as the preparation of the Redesign Project Curriculum encompassing dialogue between disciplines. Realized by the analysis of the guiding documents is a back program even for a technical rationality practiced by the particular understanding of the school and the practice being expressed from the same concepts that high school is developed, with each teacher teaching the contents of their disciplines and performing cross designs. Break the existing paradigm is still one of the challenges to the teaching-learning process. Break the existing paradigm is still one of the challenges to the teaching-learning process.