The specificity of frutalin lectin using biomembrane models

Frutalin is a homotetrameric alpha-D-galactose (D-Gal)-binding lectin that activates natural killer cells in vitro and promotes leukocyte migration in vivo. Because lectins are potent lymphocyte stimulators, understanding the interactions that occur between them and cell surfaces can help to the action mechanisms involved in this process. In this paper, we present a detailed investigation of the interactions of frutalin with phospho- and glycolipids using Langmuir monolayers as biomembrane models. The results confirm the specificity of frutalin for D-Gal attached to a biomembrane. Adsorption of frutalin was more efficient for the galactose polar head lipids, in contrast to the one for sulfated galactose, in which a lag time is observed, indicating a rearrangement of the monolayer to incorporate the protein. Regarding ganglioside GM1 monolayers, lower quantities of the protein were adsorbed, probably due to the farther apart position of D-galactose from the interface. Binary mixtures containing galactocerebroside revealed small domains formed at high lipid packing in the presence of frutalin, suggesting that lectin induces the clusterization and the forming of domains in vitro, which may be a form of receptor internalization. This is the first experimental evidence of such lectin effect, and it may be useful to understand the mechanism of action of lectins at the molecular level. (C) 2010 Elsevier B.V. All rights reserved.

A Single Mutation at the Sheet Switch Region Results in Conformational Changes Favoring lambda 6 Light-Chain Fibrillogenesis

Systemic amyloid light-chain (LC) amyloidosis is a disease process characterized by the pathological deposition of monoclonal LCs in tissue. All LC subtypes are capable of fibril formation although lambda chains, particularly those belonging to the lambda 6 type, are overrepresented. Here, we report the thermodynamic and in vitro fibrillogenic properties of several mutants of the lambda 6 protein 6aJL2 in which Pro7 and/or His8 was substituted by Ser or Pro. The H8P and H8S mutants were almost as stable as the wildtype protein and were poorly fibrillogenic. In contrast, the P7S mutation decreased the thermodynamic stability of 6aJL2 and greatly enhanced its capacity to form amyloid-like fibrils in vitro. The crystal structure of the P7S mutant showed that the substitution induced both local and long-distance effects, such as the rearrangement of the V(L) (variable region of the light chain)-V(L) interface. This mutant crystallized in two orthorhombic polymorphs, P2(1)2(1)2(1) and C222(1). In the latter, a monomer that was not arranged in the typical Bence-Jones dimer was observed for the first time. Crystal-packing analysis of the C222(1) lattice showed the establishment of intermolecular beta-beta interactions that involved the N-terminus and beta-strand B and that these could be relevant in the mechanism of LC fibril formation. Our results strongly suggest that Pro7 is a key residue in the conformation of the N-terminal sheet switch motif and, through long-distance interactions, is also critically involved in the contacts that stabilized the V(L) interface in lambda 6 LCs. (C) 2009 Elsevier Ltd. All rights reserved.

Insights into the mechanism of progressive RNA degradation by the archaeal exosome

Initially identified in yeast, the exosome has emerged as a central component of the RNA maturation and degradation machinery both in Archaea and eukaryotes. Here we describe a series of high-resolution structures of the RNase PH ring from the Pyrococcus abyssi exosome, one of them containing three 10-mer RNA strands within the exosome catalytic chamber, and report additional nucleotide interactions involving positions N5 and N7. Residues from all three Rrp41-Rrp42 heterodimers interact with a single RNA molecule, providing evidence for the functional relevance of exosome ring-like assembly in RNA processivity. Furthermore, an ADP-bound structure showed a rearrangement of nucleotide interactions at site N1, suggesting a rationale for the elimination of nucleoside diphosphate after catalysis. In combination with RNA degradation assays performed with mutants of key amino acid residues, the structural data presented here provide support for a model of exosome-mediated RNA degradation that integrates the events involving catalytic cleavage, product elimination, and RNA translocation. Finally, comparisons between the archaeal and human exosome structures provide a possible explanation for the eukaryotic exosome inability to catalyze phosphate-dependent RNA degradation.

Reactions of toluquinone - cyclopentadiene Diels -Alder epoxide adducts with nucleophiles under heterogeneous conditions

Toluquinone-cyclopentadiene Diels-Alder epoxide adducts react with sulfur and oxygen nucleophiles under heterogeneous conditions, leading to products resulting from the epoxide ring opening and from skeletal rearrangement, respectively. Pyrolysis of the sulfanyl adducts gave the new 3-sulfanyltoluquinones (1).

Ring Contraction of 1,2-Dihydronaphthalenes Promoted by Thallium(III) in Acetonitrile: A Diastereoselective Approach to Indanes

trans-1,3-Disubstituted indanes are conveniently accessed by a stereoselective ring contraction of 1,2-dihydronaphthalenes upon treatment with thallium(III) nitrate (TTN) in acetonitrile. Under these conditions, the oxidative rearrangement of either di- or trisubstituted double bonds is possible.

A Diastereoselective Total Synthesis of trans-Trikentrin A: A Ring Contraction Approach

A new route to obtain the polyalkylated indole (+/-)-trans-trikentrin A was developed. The synthesis of this natural alkaloid features a thallium(III)mediated ring contraction reaction to obtain the trans-1,3-disubstituted five-membered ring in a diastereoselective manner. Thallium(III) is chemoselective in this rearrangement, reacting with the olefin without oxidation of the indole moiety. Other key transformations are the Bartoli`s reaction to construct the heterocyclic ring and a Heck coupling to add the carbons atom that will originate the nonaromatic cycle.

Photochemical Generation and Intramolecular Chemistry of β-Alkoxycarbenes

The photolytic phenanthrene-based precursors for both β-methoxycarbene and β-ethoxycarbene were synthesized with and without a deuterium label attached to the a carbon. The incorporation of this deuterium label allowed distinction between a 1, 2-H shift and a 1, 2-O shift pathway to the respective alkyl vinyl ether, without the influence of a primary kinetic isotope effect. Photolyses of these precursors gave rearrangement products of the expected β-alkoxycarbenes. In the case of β-methoxycarbene, no methyl vinyl ether was observed due to its volatility. However, the appearance of aldehyde peaks in the NMR spectra, from an apparent further rearrangement to acetaldehyde through an enol intermediate, indicated that a 1,2-H shift had occurred. Ethyl vinyl ether was isolated following the photolysis of the β-ethoxycarbene precursor. Quantification of the two pathways showed less than 2% undergoing an ethoxy shift to the ethyl vinyl ether. Yield experiments on this photolysis demonstrated a maximum yield of β-ethoxycarbene as 43%, though this decreased as the experiment continued. Computational work on the β-ethoxycarbene system indicates that the triplet scate is more stable than the singlet. In addition, the activation energy to the 1.2-H shift pathway is remarkably low and is clearly consistent with the observed overwhelming preference for this pathway in the experiment.

Descentralizacion y participacion: dos variables democraticas tensiones y distennsiones en el sector salud, referencias a Brasil y Colombia

Este estudo tem, como tema central, a análise da descentralização e da participação como categorias democratizantes da reforma do Estado, particularmente, na área das políticas de saúde no Brasil e na Colômbia. Foi realizada uma análise teórica de ambas as categorias e de seu impacto na reformulação da relação Estado e sociedade para examinar, no último capítulo, sua conjunção na formulação, implementação e controle das políticas de saúde. Os resultados obtidos permitiram elaborar um marco analítico de gradação dos níveis de descentralização e participação assim como a importância destas na prática de uma gestão de saúde mais democrática.

Educação ambiental em escolas públicas: fundamentos para o raciocínio ecológico

A organizaçao logica do pensamento ocidental caracteriza-se pela predominancia de valores estáticos, fragmentados e abstratos. A abstração do pensamento favoreceu o desenvolvimento de uma ciencia e tecnologia alheias a relação de interdependncia entre o homem e seu ecossistema. A soberania da ciencia fragmentada, apoiada por conceitos ideológicos, políticos e economicos capitalistas, tem permitido interferencias humanas desestabilizadoras em seu ambiente. Gerou ainda uma concepç~o de desenvolvimento que combina progresso, viol~ncia e destruiç~o. Estas concepcses refletem-se nos valores e formas de organizac.o , , da sociedade ocidental, perpetuando-se através de seus sistemas educativos, entre estes, a educaç~o em escolas publicas. A urgente necesidade da ativaç~o do equilibrio ecológico, através da integraç~o do homem aos ecossistemas naturais, principalmente em paises do terceiro mundo, requer uma revis~o de valores sociais, politicos e econ8micos e uma reo~ganizaç~o do pensamento ocidental voltando-o para bases holisticas e dinamicas. A escola pública no Brasil, pode vir a ser uma peça fundamental neste processo, aproveitando-se deste movimento para reestrutur.r as bases de seu sistema educativo.

Uma analise comparativa e crítica à luz da doutrina contábil das duas formas de contabilização de leasing: "financiamento x arrendamento": um estudo de casa em arrendatária

Este trabalho objetivou investigar através de um estudo exploratório o atual estágio que se encontra o arrendamento mercantil ( Leasing Financeiro) no Brasil, identificando as disposições legais que orientam o tratamento procedendo a uma análise crítica comparativa das formas de, contabilizar o "leasing". Nesse sentido, procedeu-se a uma revisão bibliográfica das principais abordagens existentes no exterior e no Brasil e a partir das quais se criou o Plano de Referência que fundamentou a pesquisa. Em razão do propósito descritivo e comparativo do trabalho, optou-se pelo estudo de caso, tendo em vista as vantagens que o método oferece. Com base nos dados colhidos da pesquisa, fez-se um reordenamento nas demonstrações contábeis publicadas, de modo a permitir estudo comparativo, quando se utilizar como alternativa a contabilização do "leasing" (arrendamento mercantil) na forma de financiamento. Os resultados obtidos permitiram identificar as principais distorces nas demonstrações contábeis e fazer uma análise econômico-financeira e, ainda, possibilitaram que se chegasse a importantes conclusões, além de ensejarem algumas recomendações e sugestões para futuras pesquisas.

A mudança vocacional do município de Santo André e o impacto nas receitas municipais

O presente trabalho busca analisar as mudanças econômicas e de perfil produtivo ocorridas em Santo André, município integrante da Região Metropolitana de São Paulo (RMSP), com transformações em seu perfil eminentemente industrial para o incremento do setor de serviços, parcialmente decorrente dos processos de desconcentração industrial vividos em maior escala no país. Partindo-se da formação histórico-econômica local e da identificação de fenômenos globais, como a reestruturação produtiva vivida na indústria, a pesquisa procurou observar os impactos particulares desta reorganização econômica em Santo André, cujo índices apontam para maior retração industrial em comparação com outros municípios da RMSP, no período analisado que compreende os anos de 1990 a 2010. Além disso, o trabalho analisa a particular situação arrecadatória do município, tendo em vista a queda relativa de um de seus principais impostos - o ICMS – apontando questões no que se refere à gestão tributária e otimização dos recursos disponíveis no orçamento municipal. Por fim, diante da situação problema apresentada, a saber, a fragilidade financeira do poder público em contexto de perda de relevância econômica em Santo André, a pesquisa apresenta um quadro de sugestões relativas a diferentes instâncias estratégicas e estruturais, que visam à dinamização e incremento das finanças e desenvolvimento econômico andreenses. A metodologia utilizada para a construção do trabalho contou não apenas com o acesso a textos e análises de especialistas, relativos aos temas indicados, como entrevistas com diversos atores municipais e regionais, entre os quais incluem-se representantes do poder público municipal, lideranças locais de entidades públicas e privadas e pesquisadores acadêmicos.

Insights into the Specificity of Thioredoxin Reductase-Thioredoxin Interactions. A Structural and Functional Investigation of the Yeast Thioredoxin System

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Implementação da política de assistência social em Mossoró/RN : uma avaliação a partir dos centros de referência da assistência social

The current National Policy for Social Assistance (PNAS) is the instrument that regulates the organization and procedures of social-welfare actions. Developed and approved in 2004 since the Unified Social Assistance System (ITS) was crated in 2003, it reaffirms the democratic principles of the Social Assistance Organic Law (LOAS) focusing on the universalization of social rights and equality of rights when accessing the social-welfare system. In the SUAS point of view, the PNAS highlights the information, monitoring and evaluation fields for being the best way to assure the regulation, organization and control by the Federal Government paying attention to the principles of decentralization and participation. This political-institutional rearrangement occurs through the pact among all the three federal entities. The pact deals with the implementation of the task. It says that it has to be shared between the federal autonomous entities, established by dividing responsibilities. To the cities, considered as the smallest territorial unit of the federation and closer to the population, was given the primary responsibility, which is to feed and maintain the database of SUAS NETWORK and identify families living in situations of social vulnerability. In addition to these responsibilities, the cities that have full autonomy in the management of their actions, have the responsibility to organize the basic social protection and the special social protection, that using the Center of Social Assistance Reference (CRAS) and the Center of Specialized Social Assistance Reference (CREAS), are responsible for the provision of programs, projects and services that strengthen the family and community; that promote people who are able to enjoy the benefits of the Continuing benefit of Provisions (BPC) and transfer of incomes; that hold the infringed rights on its territory; that maximize the protective role of families and strengthen its users organization. In Mossoró/RN, city classified as autonomous in the social assistance management, has five units of CRAS that, for being public utilities, are considered the main units of basic social protection, since they are responsible for the connection between the other institutions that compose the network of local social protection. Also known as Family House, the CRAS, among other programs and services, offers the Integral Attention to Families Program (PAIF), Juvenile ProJovem Program, socio-educational coexistence services programs, as well as sending people to other public policies and social-welfare services network, provides information, among others. In this large field, social workers are highlighted as keys to implement the policy of social assistance within the city, followed by psychologists and educators. They should be effective public employees, as a solution to ensure that the provision of the services are to be continued, provided to the population living around the units. However, what we can find here is inattention to the standard rules of social assistance, which not only undermines the quality of programs and services, but also the consolidation of policy on welfare as public policy of social rights

A política de formação inicial de professores e a implementação do componente curricular Prática Profissional na Licenciatura de Geografia do CEFET-RN

This work is a research about the policy of initial education of teachers made by the federal government, in the Brazilian educational view in the 1990 s. It is based on that the procedures to the initial education of teachers are in a much bigger context of the productive rearrangement and of the reconstruction of the State and they have in the international institutions, like the CEPAL, UNESCO and the World Bank, their main mediators. The dissertation aims to analyze the implementation of the policy of initial education of educators, having as empirical field the CEFET RN institution, and as reference the undergraduate course of Geography, more specifically the subject vocational practice. This study is advised by the theoretical and methodological fundamentals of the qualitative research, and it is being characterized by a case study. Among the methodological procedures which were used, some of them can be pointed out such as, the bibliographic research, the documental analysis, the application of questionnaires and the carrying out of interviews. The studies show up CEFETs and the Superior Education Institutes were considered by the Brazilian government suitable for the introduction of the initial education of vocational training, related to teaching, a proposed model by updated principles of international organizations. However, in the CEFET RN reality, although the difficulties listed by the teachers and students in the introduction of the subject vocational practice, the initial background in the undergraduate course of Geography got one point which is getting close to the teaching that is carried out in universities, privileging teaching, research and extension. For the people who have participated of researches, the subject vocational practice is relevant for the curriculum of teaching education because it makes the articulation between theory and practice possible, aspects considered essential ones for a teaching education of quality. Also, the studies show that one of the big obstacles faced in the introduction of the subject in question, was the lack of assistance to the students who are in a period of training and in the execution of research and extension projects caused by the insufficiency of educators to perform in the undergraduate course, as well as the lack of time of the teachers due to a large number of activities that they develop in their workplace (CEFET RN). This fact reveals the way how the policy of education of teachers came to educational institutions, imposed by MEC, without considering their structure conditions. Although the difficulties, the innovator character of the experience stood out, as in relation to the locus of education as because of being an educational model which involves theory and practice and the different kinds of knowledge, pretty necessary ones for the teaching education, as well as coming beyond a pragmatic education coherent with the immediate interests of the world of work

Tuberculose: conhecimentos, representações sociais e experiências da doença na visão do portador

Tuberculosis is considered one of the most ancient human diseases, cases were registered 3900 years before Christ, and it is currently regarded as a serious public health problem in the world due to several factors such as income mismanagement, precarious standard of life and some sort of prejudice comprised by the word tuberculosis. Taking this into consideration, it was developed a descriptive and exploratory study aiming at analyzing the social representations of tuberculosis made by its patient from the Unidades de Saúde da Família (Family Health Units a public health program) in Campina Grande City PB, in relation to the decentralization of the policies that administrate the disease. It was interviewed 34 tuberculosis patient that were being treated from 2007 to 2008. The age group of the interviewees varied from 10 to 60 years old, but most of them were between 36 and 60 years old (58,8%, n=20), some were young adult and adult (21 35 years old), with 11 (32,3%) respondents, and, less frequent, children and teenagers (11 20 years old), with 03 (8,8%) participants. Data was collected through semi-structured interview. The questions that guided the research were elaborated based on the operational recommendations of DOTS strategy; that is: access to laboratory examinations; medication guarantee; directly observed treatment. Besides that, the experiences of the patient were considered in their relation with the family and the different social groups. The analysis of the discursive material was submitted to the Analyse Lexicale par Context d un Ensemble de Segments de Texte software - ALCESTE 4.7. Data interpretation showed five categories for the social representations of the tuberculosis patient that participated in DOTS strategy: 1) the accessibility of the health assistance service; 2) the patient perspective of the disease; 3) the change in the operation of the productive life; 4) the signals and symptoms of the tuberculosis disease; 5) the rearrangement and mechanisms used to face the disease. The Central Nucleus reveals that tuberculosis is a transmissible disease that can be prevented by people through educational practices, health promotion, active search for symptomatic respiratory and control of the carriers communication; these mechanisms should be incorporated to the routine of all participants of the family health groups. The Intermediate Elements, based on quotidian life, as well as the individual experiences of the tuberculosis patient, reveals prejudiced attitude and beliefs that lead to isolation and restriction of interpersonal relationship. Peripheral Elements were constituted by themes that showed the patient feelings of indignation because of the social barriers they had to face in the Family Health Units during the treatment. These elements demonstrate a negative perspective of the representation concerning the accessibility, i.e. inadequate structure of the health service; long distance to the Health Centre, this factormakes it difficult for the patient to continue the treatment; scheduling delay; and limited service regarding other requests (doctor, dentist etc). One expects to contribute for the construction of a new perspective of the health question between the different agents who make the assistencial institutions and formation of professionals, either in central or local scope