Structure of Mycobacterium thermoresistibile GlgE defines novel conformational states that contribute to the catalytic mechanism.

GlgE, an enzyme of the pathway that converts trehalose to α-glucans, is essential for Mycobacterium tuberculosis. Inhibition of GlgE, which transfers maltose from a maltose-1-phosphate donor to α-glucan/maltooligosaccharide chain acceptor, leads to a toxic accumulation of maltose-1-phosphate that culminates in cellular death. Here we describe the first high-resolution mycobacterial GlgE structure from Mycobacterium thermoresistibile at 1.96 Å. We show that the structure resembles that of M. tuberculosis and Streptomyces coelicolor GlgEs, reported before, with each protomer in the homodimer comprising five domains. However, in M. thermoresistibile GlgE we observe several conformational states of the S domain and provide evidence that its high flexibility is important for enzyme activity. The structures here reported shed further light on the interactions between the N-terminal domains and the catalytic domains of opposing chains and how they contribute to the catalytic reaction. Importantly this work identifies a useful surrogate system to aid the development of GlgE inhibitors against opportunistic and pathogenic mycobacteria.This is the final version of the article. It was first available from NPG via http://dx.doi.org/10.1038/srep1714

Biochemical characterization of the maltokinase from Mycobacterium bovis BCG

<p>Abstract</p> <p>Background</p> <p>Maltose-1-phosphate was detected in <it>Mycobacterium bovis </it>BCG extracts in the 1960's but a maltose-1-phosphate synthetase (maltokinase, Mak) was only much later purified from <it>Actinoplanes missouriensis</it>, allowing the identification of the <it>mak </it>gene. Recently, this metabolite was proposed to be the intermediate in a pathway linking trehalose with the synthesis of glycogen in <it>M. smegmatis</it>. Although the <it>M. tuberculosis </it>H37Rv <it>mak </it>gene (Rv0127) was considered essential for growth, no mycobacterial Mak has, to date, been characterized.</p> <p>Results</p> <p>The sequence of the Mak from <it>M. bovis </it>BCG was identical to that from <it>M. tuberculosis </it>strains (99-100% amino acid identity). The enzyme was dependent on maltose and ATP, although GTP and UTP could be used to produce maltose-1-phosphate, which we identified by TLC and characterized by NMR. The K_{<it>m </it>}for maltose was 2.52 ± 0.40 mM and 0.74 ± 0.12 mM for ATP; the <it>V</it>_maxwas 21.05 ± 0.89 μmol/min.mg^-1. Divalent cations were required for activity and Mg²⁺was the best activator. The enzyme was a monomer in solution, had maximal activity at 60°C, between pH 7 and 9 (at 37°C) and was unstable on ice and upon freeze/thawing. The addition of 50 mM NaCl markedly enhanced Mak stability.</p> <p>Conclusions</p> <p>The unknown role of maltokinases in mycobacterial metabolism and the lack of biochemical data led us to express the <it>mak </it>gene from <it>M. bovis </it>BCG for biochemical characterization. This is the first mycobacterial Mak to be characterized and its properties represent essential knowledge towards deeper understanding of mycobacterial physiology. Since Mak may be a potential drug target in <it>M. tuberculosis</it>, its high-level production and purification in bioactive form provide important tools for further functional and structural studies.</p

“Private and personal”:Corporate political activity, informal governance, and the undermining of marketing regulation in Brazil

Few studies have investigated corporate political activity by unhealthy commodity industries in low- and middle-income countries, and the significance of social and political context has been largely neglected. This study aimed to explore the stalled development of marketing restriction policies in Brazil with an analysis of strategies used to undermine the Legal Framework for Early Childhood. Using a constructivist approach based on a typology of corporate political strategies, decision-making processes were assessed to understand interference by food companies in the Legal Framework, and how this was perceived by policy actors. Semi-structured interviews were conducted with public health advocates, academics and legislature officials. Three broad strategies that contributed to the stalling of marketing restrictions in the Legal Framework were identified: relational approaches to policy influence; collective participation in formal decision-making; and specific strategy choices (information and financial incentives). Key opportunities for policy influence through informal social networks in the ‘backstage’ of policy making are found to privilege commercial sector actors. Informal policy making may have a critical function in obstructing the development of health-focused regulation in Brazil. This highlights the need for a better understanding of non-codified and hidden corporate efforts to shape the policy environment

Self-recycling and partially conservative replication of mycobacterial methylmannose polysaccharides

The steep increase in nontuberculous mycobacteria (NTM) infections makes understanding their unique physiology an urgent health priority. NTM synthesize two polysaccharides proposed to modulate fatty acid metabolism: the ubiquitous 6-O-methylglucose lipopolysaccharide, and the 3-O-methylmannose polysaccharide (MMP) so far detected in rapidly growing mycobacteria. The recent identification of a unique MMP methyltransferase implicated the adjacent genes in MMP biosynthesis. We report a wide distribution of this gene cluster in NTM, including slowly growing mycobacteria such as Mycobacterium avium, which we reveal to produce MMP. Using a combination of MMP purification and chemoenzymatic syntheses of intermediates, we identified the biosynthetic mechanism of MMP, relying on two enzymes that we characterized biochemically and structurally: a previously undescribed ?-endomannosidase that hydrolyses MMP into defined-sized mannoligosaccharides that prime the elongation of new daughter MMP chains by a rare ?-(1?4)-mannosyltransferase. Therefore, MMP biogenesis occurs through a partially conservative replication mechanism, whose disruption affected mycobacterial growth rate at low temperature

Intra-family food insecurity and profile of food consumption

OBJECTIVE: Describe and evaluate daily food consumption among families experiencing food insecurity. METHODS: A population survey was conducted in Campinas, São Paulo, in 2003, with 456 families. One qualified member of each family was interviewed about their daily intake of 14 food groups. For the food insecurity classification, a scale divided into three categories was used: 1) Food security; 2) Mild food insecurity; 3) Moderate or Severe food insecurity. RESULTS: Significant differences were found among the categories of food insecurity with respect to food consumption. The proportion of respondents from families experiencing moderate or severe food insecurity or mild food insecurity that did not consume dairy products, fruits, vegetables, meats, on a daily basis is significantly higher than respondents from families who are food-secure (p<0.001). Among food-secure families, 73.7% consumed at least one fruit per day and 62.1% consumed dairy products every day. These percentages were 11.4% and 5.5%, respectively, in families with moderate or severe food insecurity. The majority of these families consumed only grains, oil, sugar, and dried beans on a daily basis, and they spend roughly 68% of their monthly income on food. There are significant differences in the frequency of the main daily meals among the food security categories, which is always less frequent among families with moderate or severe food insecurity. CONCLUSION: Families experiencing moderate or severe food insecurity have a boring diet, composed basically of energetic foods. Even among food secure families, adequate diet quality was not always present. These results show that it is necessary to strengthen nutrition education efforts in public policies that aim to improve food security and promote healthy diets.OBJETIVO: Descrever e avaliar o perfil de consumo diário de alimentos entre famílias em situação de insegurança alimentar. MÉTODOS: Inquérito populacional realizado em Campinas (SP), em 2003, com 456 famílias. Realizou-se levantamento do consumo diário de 14 grupos de alimentos, mediante informação de membro qualificado da família. Para categorização da insegurança alimentar utilizou-se uma escala dividida em 3 categorias: 1) Segurança alimentar; 2) Insegurança alimentar leve; 3) Insegurança alimentar moderada ou grave. RESULTADOS: Foram detectadas diferenças significativas entre categorias de segurança alimentar e consumo alimentar. A proporção de famílias em situação de insegurança, cujo informante não consome diariamente leite e derivados, frutas, verduras/legumes, e carnes é significantemente maior do que aquelas em situação de segurança alimentar (p<0,001). Nas famílias em segurança alimentar, o consumo de pelo menos uma fruta diariamente foi 73,7% e de derivados do leite 62,1%. Essas proporções são 11,4% e 5,5%, respectivamente, em famílias que experimentam insegurança alimentar moderada ou grave. Nestas últimas, a maioria consome diariamente apenas cereais, óleo, açúcar e feijão e gasta cerca de 68,0% da renda com despesas em alimentação. Existem diferenças significantes na freqüência das principais refeições diárias entre as categorias de segurança, sempre com menor freqüência entre os informantes das famílias em insegurança alimentar moderada ou grave. CONCLUSÃO: Famílias em insegurança alimentar moderada ou grave apresentaram dieta monótona, basicamente composta por alimentos energéticos. A condição de acesso ao alimento entre famílias em segurança alimentar, entretanto, não garantiu a adequação qualitativa da dieta. Esses resultados trazem a necessidade de reforçar, nas políticas de segurança alimentar, ações educativas direcionadas à promoção de alimentação saudável.135s144

[food Insecurity Perception In Families With Elderly In Campinas, São Paulo, Brazil].

The aim of this study was to determine the prevalence of food insecurity (FI) in families with elderly members and to describe their socio-demographic profile. The study focused on families with members aged 65 years or more (n = 195) participating in a household survey in Campinas, São Paulo, Brazil, in 2003. The Brazilian Food Insecurity Scale, an adaptation of the USDA FI module, was used to diagnose food security/insecurity (FS/FI). Mild FI was present in 33.0% of families, moderate in 11.8%, and severe in 7.2%. The elderly had no income in < 5.0% of the families. Families with FI, as in the United States, had a greater proportion of elderly with low income and low level of education (no schooling or incomplete primary schooling). A significantly higher proportion of daily qualitative food intake was observed in FS families (vegetables 92.3 vs. 61.8%; OR = 7.4; 95%CI: 2.9-19.6; meat 74.2 vs. 43.1%; OR = 3.8; 95%CI: 1.9-7.3; fruit 77.4 vs. 49.0%; OR = 3.6; 95%CI: 1.8-6.9). The elderly contribute to family income and thus do not pose a burden to their families.211433-4

Food insecurity perception in families with elderly in Campinas, São Paulo, Brazil

The aim of this study was to determine the prevalence of food insecurity (FI) in families with elderly members and to describe their socio-demographic profile. The study focused on families with members aged 65 years or more (n = 195) participating in a household survey in Campinas, São Paulo, Brazil, in 2003. The Brazilian Food Insecurity Scale, an adaptation of the USDA FI module, was used to diagnose food security/insecurity (FS/FI). Mild FI was present in 33.0% of families, moderate in 11.8%, and severe in 7.2%. The elderly had no income in < 5.0% of the families. Families with FI, as in the United States, had a greater proportion of elderly with low income and low level of education (no schooling or incomplete primary schooling). A significantly higher proportion of daily qualitative food intake was observed in FS families (vegetables 92.3 vs. 61.8%; OR = 7.4; 95%CI: 2.9-19.6; meat 74.2 vs. 43.1%; OR = 3.8; 95%CI: 1.9-7.3; fruit 77.4 vs. 49.0%; OR = 3.6; 95%CI: 1.8-6.9). The elderly contribute to family income and thus do not pose a burden to their families.O objetivo deste estudo foi determinar a prevalência de insegurança alimentar em famílias com idosos e descrever seu perfil sócio-demográfico. Foram estudadas famílias com membros de 65 anos e mais (n = 195), selecionadas de inquérito domiciliar realizado em 2003, em Campinas, São Paulo, Brasil. A Escala Brasileira de Insegurança Alimentar, versão brasileira do módulo de insegurança alimentar do United States Department of Agriculture, foi utilizada para diagnosticar segurança/insegurança alimentar (SA/IA). Observou-se insegurança alimentar leve em 33,0% das famílias, moderada em 11,8% e grave em 7,2%. Em menos de 5,0% das famílias o idoso não tinha renda. Os idosos de famílias com insegurança alimentar apresentaram, em forma similar aos Estados Unidos, maior proporção de idosos de baixa renda (< R$ 500,00) e baixa escolaridade (até o primário incompleto). As famílias em segurança alimentar apresentaram significativa maior proporção de consumo qualitativo diário de alimentos (verduras 92,3 vs. 61,8%; OR = 7,4; IC95%: 2,9-19,6; carne 74,2 vs. 43,1%; OR = 3,8; IC95%: 1,9-7,3; frutas 77,4 vs. 49,0% OR = 3,6; IC95%: 1,8-6,9). Os idosos contribuem para a renda familiar, não sendo, portanto, uma carga para suas famílias.1433144

Characterisation of ground thermal and thermo-mechanical behaviour for shallow geothermal energy applications

Increasing use of the ground as a thermal reservoir is expected in the near future. Shallow geothermal energy (SGE) systems have proved to be sustainable alternative solutions for buildings and infrastructure conditioning in many areas across the globe in the past decades. Recently novel solutions, including energy geostructures, where SGE systems are coupled with foundation heat exchangers, have also been developed. The performance of these systems is dependent on a series of factors, among which the thermal properties of the soil play one of major roles. The purpose of this paper is to present, in an integrated manner, the main methods and procedures to assess ground thermal properties for SGE systems and to carry out a critical review of the methods. In particular, laboratory testing through either steady-state or transient methods are discussed and a new synthesis comparing results for different techniques is presented. In-situ testing including all variations of the thermal response test is presented in detail, including a first comparison between new and traditional approaches. The issue of different scales between laboratory and in-situ measurements is then analysed in detail. Finally, thermo-hydro-mechanical behaviour of soil is introduced and discussed. These coupled processes are important for confirming the structural integrity of energy geostructures, but routine methods for parameter determination are still lacking

(In) Segurança Alimentar: experiência de grupos focais com populações rurais do Estado de São Paulo

O presente trabalho apresenta a experiência de grupos focais com participantes oriundos de populações rurais do Estado de São Paulo, que possibilitou analisar e elucidar a compreensão existente acerca dos conceitos utilizados pela Escala Norte-Americana para Medida de Segurança Alimentar (USDA Core Food Security Module, hoje denominada Household Food Insecurity Access Scale - HFIAS), previamente adaptada e validada para populações brasileiras urbanas. Essa fase qualitativa antecedeu e forneceu subsídios para realização da fase quantitativa do estudo de validação dessa escala para populações rurais. Foram realizados dois grupos focais, compostos, cada um, por 12 participantes, escolhidos e convidados para representar diferentes categorias da população rural paulista, incluindo: assentados, agricultores familiares tradicionais, trabalhadores assalariados e quilombolas. Os conceitos e palavras-chave investigados foram: “Segurança alimentar”; “Qualidade da alimentação”; “Alimentação saudável”; “Alimentação variada”; “Alimentação saudável e variada”; “Alimento suficiente”; “Condições para ter alimento suficiente: trocas, reserva, estoque, produção de alimentos para consumo e compra de alimentos”; “Dinheiro suficiente”; “Ficar sem nenhum dinheiro”; “Insegurança alimentar” e “Fome”. Os participantes expressaram uma compreensão abrangente sobre segurança alimentar, englobando diferentes aspectos do tema. A análise dos depoimentos desses grupos focais apontou para o reconhecimento no conceito de segurança alimentar do direito humano à alimentação, o que envolve também questões como acesso ao trabalho, saúde, educação, moradia e renda. Na compreensão do termo “Qualidade da alimentação” ficou evidente a preocupação com o consumo de produtos sem agrotóxicos, tendo sido observadas, em menor escala, referências às questões de preço e aparência mais recorrentes nos grupos focais com populações urbanas. Os resultados conduziram a modificações no questionário e contribuíram para o desenvolvimento da Escala Brasileira de Insegurança Alimentar (EBIA), válida para diagnosticar essa condição e monitorar o impacto de políticas voltadas para o combate à fome no país. O processo de validação concluído permitiu o uso da escala brasileira em projetos de pesquisa sobre segurança alimentar que atenderam a um edital do CNPq, ainda em 2003, e posteriormente, essa escala foi incorporada ao suplemento de segurança alimentar da Pesquisa Nacional por Amostra de Domicílios (PNAD-2004), do Instituto Brasileiro de Geografia e Estatística (IBGE)