342 research outputs found

    Feeding practices and physical inactivity contributions to childhood overweight

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    OBJECTIVE: To review the literature in order to show how current feeding and physical activity practices may contribute to childhood overweight. DATA SOURCE: Ovid Journals, Highwire and SciELO, selecting original and review articles from 1997 to 2007, published in English and Portuguese. DATA SYNTHESIS: The periodic assessment of children nutritional status is important to diagnose their current health status and to predict their adult life prognosis. In Brazil, the prevalence of childhood obesity is progressively increasing in all social classes and its frequency varies from five to 18%, according to the region assessed. The association between the health, demographic and behavioral transition and the change in feeding practices can explain the increasing prevalence of childhood overweight. The current food consumption with high fat, sugar and sodium intake and low intake of whole cereals, fruits and vegetables associated to physical inactivity due to the excessive use of computers, electronic games and television may play a role in childhood obesity. This life style can be explained by changing family habits and school environment. CONCLUSIONS: These data suggest considerable influence of environmental factors, mainly nutritional habits and physical inactivity, on the increasing prevalence of childhood overweight.OBJETIVO: Revisar estudos que abordam as práticas alimentares atuais e o padrão de atividade física como contribuintes do excesso de peso na infância. FONTES DE DADOS: Ovid Journals, Highwire e SciELO, com seleção de artigos originais e de revisão nos últimos dez anos (1997 a 2007), na língua portuguesa e inglesa. SÍNTESE DE DADOS: O acompanhamento do estado nutricional de crianças permite diagnosticar seu estado de saúde atual, bem como predizer parcialmente seu prognóstico na vida adulta. A prevalência de obesidade infantil, no Brasil, apresenta aumento progressivo em todas as classes sociais e sua freqüência varia entre cinco a 18%, dependendo da região estudada. A associação da transição epidemiológica, demográfica e comportamental e a alteração do hábito alimentar são apontadas como fatores causais do aumento progressivo da obesidade infantil. Práticas alimentares caracterizadas por elevado teor de lipídios, sacarose e sódio e por reduzido consumo de cereais integrais, frutas e hortaliças associadas à inatividade física decorrente do uso de computadores, jogos eletrônicos e televisores influenciam parte considerável de crianças. Este estilo de vida reflete os hábitos familiares e pode ser influenciado pelo ambiente escolar no qual a criança está inserida. CONCLUSÕES: Os dados sugerem influência considerável dos fatores ambientais, principalmente hábitos alimentares e inatividade física, no crescente aumento da prevalência de excesso de peso na população pediátrica.Universidade Estadual Paulista Faculdade de Medicina de BotucatuUniversidade Federal do Rio de JaneiroUnesp FMB Departamento de PediatriaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de FisiologiaUnesp FMBUNIFESP, EPM, Depto. de FisiologiaSciEL

    Trapped lipopolysaccharide and LptD intermediates reveal lipopolysaccharide translocation steps across the Escherichia coli outer membrane

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    Lipopolysaccharide (LPS) is a main component of the outer membrane of Gram-negative bacteria, which is essential for the vitality of most Gram-negative bacteria and plays a critical role for drug resistance. LptD/E complex forms a N-terminal LPS transport slide, a hydrophobic intramembrane hole and the hydrophilic channel of the barrel, for LPS transport, lipid A insertion and core oligosaccharide and O-antigen polysaccharide translocation, respectively. However, there is no direct evidence to confirm that LptD/E transports LPS from the periplasm to the external leaflet of the outer membrane. By replacing LptD residues with an unnatural amino acid p-benzoyl-L-phenyalanine (pBPA) and UV-photo-cross-linking in E.coli, the translocon and LPS intermediates were obtained at the N-terminal domain, the intramembrane hole, the lumenal gate, the lumen of LptD channel, and the extracellular loop 1 and 4, providing the first direct evidence and “snapshots” to reveal LPS translocation steps across the outer membrane

    Nanocomposite sprayed films with photo-thermal properties for remote bacteria eradication

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    Currently there is a strong demand for novel protective materials with effcient antibacterial properties. Nanocomposite materials loaded with photo-thermally active nanoparticles can offer promising opportunities due to the local increase of temperature upon near-infrared (NIR) light exposure capable of eradicating bacteria. In this work, we fabricated antibacterial films obtained by spraying on glass slides aqueous solutions of polymers, containing highly photo-thermally active gold nanostars (GNS) or Prussian Blue (PB) nanoparticles. Under NIR light irradiation with low intensities (0.35W/cm2) these films demonstrated a pronounced photo-thermal effect: 06Tmax up to 26.4 ffC for the GNS-containing films and 06Tmax up to 45.8 ffC for the PB-containing films. In the latter case, such a local temperature increase demonstrated a remarkable effect on a Gram-negative strain (P. aeruginosa) killing (84% of dead bacteria), and a promising effect on a Gram-positive strain (S. aureus) eradication (69% of dead bacteria). The fabricated films are promising prototypes for further development of lightweight surfaces with effcient antibacterial action that can be remotely activated on demand

    Self-assembled monolayers of copper sulfide nanoparticles on glass as antibacterial coatings

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    We developed an easy and reproducible synthetic method to graft a monolayer of copper sulfide nanoparticles (CuS NP) on glass and exploited their particular antibacterial features. Samples were fully characterized showing a good stability, a neat photo-thermal effect when irradiated in the Near InfraRed (NIR) region (in the so called \u201cbiological window\u201d), and the ability to release controlled quantities of copper in water. The desired antibacterial activity is thus based on two different mechanisms: (i) slow and sustained copper release from CuS NP-glass samples, (ii) local temperature increase caused by a photo-thermal effect under NIR laser irradiation of CuS NP\u2013glass samples. This behavior allows promising in vivo applications to be foreseen, ensuring a \u201cstatic\u201d antibacterial protection tailored to fight bacterial adhesion in the critical timescale of possible infection and biofilm formation. This can be reinforced, when needed, by a photo-thermal action switchable on demand by an NIR light

    Efficacy of a food supplement based on S-adenosyl methionine and probiotic strains in subjects with subthreshold depression and mild-to-moderate depression: A monocentric, randomized, cross-over, double-blind, placebo-controlled clinical trial

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    Depression is one of the most serious chronic psychiatric disorders affecting people worldwide. Subthreshold depression (SD) is a form of subclinical depression with increased risk of major depressive disorder (MDD). Patients diagnosed with SD may not be eligible for antidepressant drugs and, particularly in the case of MDD, these antidepressants may have adverse effects which outweigh their therapeutic effects, leading to discontinuation of therapy. Food supplements could provide an alternative strategy. The aim of this study is to demonstrate the efficacy of a food supplement based on a combination of S-adenosyl methionine (SAMe, 200 mg/day) and probiotics (Lactobacillus helveticus Rosell®−52, Bifidobacterium longum Rosell®−175, 3 ×109 CFU/day) in reducing depression symptoms in a monocentric, randomised, double-blind, placebo-controlled, cross-over clinical trial. 80 Subjects were recruited and offered the food supplement or placebo daily for three months, according to a cross-over clinical trial design, followed by a six-week follow-up period. The efficacy of the food supplement was measured by means of the “Hamilton Depression Rating Scale” (HAM-D) and "Patient Health Questionnaire-9" (PHQ-9), using a mixed analysis of variance model, with random intercept, for statistical analysis. The food supplement showed a significant decrease of PHQ-9 and HAM-D scores resulting in reduced SD and MDD symptoms as compared to placebo. In conclusion, the daily intake of the food supplement based on SAMe and probiotic strains for a period of three months is effective in improving the quality of life of SD subjects who are not eligible for antidepressant therapies, and patients suffering from mild-to-moderate depression who are not sensitive or cannot tolerate conventional drugs

    The Escherichia coli Lpt transenvelope protein complex for lipopolysaccharide export is assembled via conserved structurally homologous domains

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    Lipopolysaccharide is a major glycolipid component in the outer leaflet of the outer membrane (OM), a peculiar permeability barrier of Gram-negative bacteria that prevents many toxic compounds from entering the cell. Lipopolysaccharide transport (Lpt) across the periplasmic space and its assembly at the Escherichia coli cell surface are carried out by a transenvelope complex of seven essential Lpt proteins spanning the inner membrane (LptBCFG), the periplasm (LptA), and the OM (LptDE), which appears to operate as a unique machinery. LptC is an essential inner membrane-anchored protein with a large periplasm-protruding domain. LptC binds the inner membrane LptBFG ABC transporter and interacts with the periplasmic protein LptA. However, its role in lipopolysaccharide transport is unclear. Here we show that LptC lacking the transmembrane region is viable and can bind the LptBFG inner membrane complex; thus, the essential LptC functions are located in the periplasmic domain. In addition, we characterize two previously described inactive single mutations at two conserved glycines (G56V and G153R, respectively) of the LptC periplasmic domain, showing that neither mutant is able to assemble the transenvelope machinery. However, while LptCG56V failed to copurify any Lpt component, LptCG153R was able to interact with the inner membrane protein complex LptBFG. Overall, our data further support the model whereby the bridge connecting the inner and outer membranes would be based on the conserved structurally homologous jellyroll domain shared by five out of the seven Lpt components
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