390 research outputs found

    Deciphering the Symbiotic Significance of Quorum Sensing Systems of Sinorhizobium fredii HH103

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    Quorum sensing (QS) is a bacterial cell-to-cell signaling mechanism that collectively regulates and synchronizes behaviors by means of small diffusible chemical molecules. In rhizobia, QS systems usually relies on the synthesis and detection of N-acyl-homoserine lactones (AHLs). In the model bacterium Sinorhizobium meliloti functions regulated by the QS systems TraI-TraR and SinI-SinR(-ExpR) include plasmid transfer, production of surface polysaccharides, motility, growth rate and nodulation. These systems are also present in other bacteria of the Sinorhizobium genus, with variations at the species and strain level. In Sinorhizobium fredii NGR234 phenotypes regulated by QS are plasmid transfer, growth rate, sedimentation, motility, biofilm formation, EPS production and copy number of the symbiotic plasmid (pSym). The analysis of the S. fredii HH103 genomes reveal also the presence of both QS systems. In this manuscript we characterized the QS systems of S. fredii HH103, determining that both TraI and SinI AHL-synthases proteins are responsible of the production of short- and long-chain AHLs, respectively, at very low and not physiological concentrations. Interestingly, the main HH103 luxR-type genes, expR and traR, are split into two ORFs, suggesting that in S. fredii HH103 the corresponding carboxy-terminal proteins, which contain the DNA-binding motives, may control target genes in an AHL-independent manner. The presence of a split traR gene is common in other S. fredii strains.Spanish Ministerio de Economía y Competitividad (MINECO) BIO2016-78409-

    Neuroprotective efficacy of P7C3 compounds in primate hippocampus.

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    There is a critical need for translating basic science discoveries into new therapeutics for patients suffering from difficult to treat neuropsychiatric and neurodegenerative conditions. Previously, a target-agnostic in vivo screen in mice identified P7C3 aminopropyl carbazole as capable of enhancing the net magnitude of postnatal neurogenesis by protecting young neurons from death. Subsequently, neuroprotective efficacy of P7C3 compounds in a broad spectrum of preclinical rodent models has also been observed. An important next step in translating this work to patients is to determine whether P7C3 compounds exhibit similar efficacy in primates. Adult male rhesus monkeys received daily oral P7C3-A20 or vehicle for 38 weeks. During weeks 2-11, monkeys received weekly injection of 5'-bromo-2-deoxyuridine (BrdU) to label newborn cells, the majority of which would normally die over the following 27 weeks. BrdU+ cells were quantified using unbiased stereology. Separately in mice, the proneurogenic efficacy of P7C3-A20 was compared to that of NSI-189, a proneurogenic drug currently in clinical trials for patients with major depression. Orally-administered P7C3-A20 provided sustained plasma exposure, was well-tolerated, and elevated the survival of hippocampal BrdU+ cells in nonhuman primates without adverse central or peripheral tissue effects. In mice, NSI-189 was shown to be pro-proliferative, and P7C3-A20 elevated the net magnitude of hippocampal neurogenesis to a greater degree than NSI-189 through its distinct mechanism of promoting neuronal survival. This pilot study provides evidence that P7C3-A20 safely protects neurons in nonhuman primates, suggesting that the neuroprotective efficacy of P7C3 compounds is likely to translate to humans as well

    Impact of Impaired Glucose Metabolism on Periodontitis Progression over Three Years

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    We evaluated the relationship between glucose abnormalities and periodontitis in overweight/obese individuals. Eight hundred and seventy (870) diabetes-free participants aged 40–65 years completed the three-year follow-up in the San Juan Overweight Adults Longitudinal Study. The ADA thresholds for fasting and 2-h post-load glucose and HbA1c were used to define prediabetes. The NHANES methods were used to assess periodontitis. Multivariable linear regression was used to evaluate the relationship between baseline glucose metabolism measures and periodontitis at follow-up, adjusting for potential confounders. There was no association between impaired glucose measures and mean pocket depth (PD), mean clinical attachment loss (CAL), or mean percent of sites ≥5 mm PD. Impaired glucose tolerance (IGT) was associated with a lower mean percent of sites ≥5 mm CAL (β = −1.6, p = 0.037). Prediabetes and impaired fasting glucose (IFG) were associated with improvement in mean percent of sites ≥5 mm PD (β = −1.4, p = 0.022; β = −1.6, p = 0.032; respectively). IFG and IGT were associated with improvement in mean percent of sites with ≥5 mm CAL (β = −1.6, p = 0.038; β = −1.9, p = 0.020; respectively). In conclusion, there were no consistent associations between baseline prediabetes or insulin resistance and periodontitis progression over a three-year period

    Comida chatarra, Estado y mercado

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    El objetivo fundamental de esta colección es un llamado a la reflexión y a la toma de conciencia por parte de todos los involucrados –padres de familia, educadores, directivos de empresa, líderes políticos, organizaciones de la sociedad civil, entre otros– sobre los peligros y las graves consecuencias derivadas del creciente sobrepeso y de la obesidad en nuestra sociedad, sin descuidar la otra cara de la moneda que es la desnutrición crónica infantil. En segundo lugar, se busca provocar la reflexión y el debate sobre el rol del Estado, el mercado, las empresas (tanto la industria de alimentos como las agencias de publicidad), la sociedad civil y las familias, en la provocación o prevención de esta epidemia. Finalmente, buscamos plantear diversas soluciones para este problema antes de que sea demasiado tarde

    Discoloration on Methylene Blue Solutions by Direct and Catalytic Ozonation

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    During textile manufacturing, huge amounts of wastewaters characterized by removed impurities and high concentrations of dye are produced. These wastewaters cause several problems when they are discharged to the environment. The use of ozone in wastewater treatment results of interest. In this work we propose to assess the discoloration rate of different synthetic wastewaters as a function of pH, dye concentration (methylene blue (MB)) and reaction time. A comparison of discoloration rate between conventional ozonation and catalytic ozonation salts of copper, zinc, silver and nickel was also performed. For the optimization of the ozonation process of colored solutions, it was used a central composite experimental design with five replicates of the center point resulting to evaluate the influence of the independent variables at different ranges of pH, [MB] and time. In the catalyst-assisted ozonation, [MB], pH and the reaction time were fixed to 100 mg/L, 5.5 and 15 min, respectively. The optimized experimental conditions to provide maximum discoloration were pH = 3.3; [MB] = 8.6 mg/L and time = 74.3 min. Regarding the catalyst-assisted ozonation, it was found that CuSO4 catalyst gave better color reduction if compared with other catalysts assayed.Rodríguez López, AD.; García Garrido, J.; Pérez Ramiro, C.; Garcia-Castello, EM. (2013). Discoloration on Methylene Blue Solutions by Direct and Catalytic Ozonation. Journal of Materials Science and Chemical Engineering. 1(5):33-38. doi:10.4236/msce.2013.1500733381

    Detecting prediabetes among Hispanics/Latinos from diverse heritage groups: Does the test matter? Findings from the Hispanic Community Health Study/Study of Latinos

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    The objectives of this analysis were to compare the ability of fasting plasma glucose (FPG), post oral load plasma glucose (2hPG), and hemoglobin A1c (HbA1c) to identify U.S. Hispanic/Latino individuals with prediabetes, and to assess its cardiovascular risk factor correlates

    Tropoelastin and fibulin overexpression in the subepitelial connective tissue of human pterigium

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    Purpose To evaluate possible changes in the collagen and elastic components of the subepithelial connective tissue of human pterygium. Design Immunohistochemical study. Methods Immunohistochemical staining using antitropoelastin, anti-fibulin-2, and anti-fibulin-3 antibodies was performed in 10 normal conjunctival and 20 pterygium specimens. Masson trichome staining also was performed to study subepithelial connective tissue. Sirius red staining was used to identify collagen type I and III components. Tropoelastin, fibulin-2, and fibulin-3 messenger ribonucleic acid (mRNA) expressions were analyzed in 9 conjunctival and 12 pterygium specimens by quantitative real-time polymerase chain reaction assay. Results The subepithelial connective tissue and vessels were more predominant in pterygium compared with the normal conjunctival tissue. Amorphous subepithelial zones were observed in the areas of the pterygium tissue, but not in normal conjunctiva. Increased tropoelastin staining was seen in the pterygium tissue with areas of degenerative changes or immature formation of elastic fibers, as well an increase in tropoelastin mRNA, in contrast with fibulin-2 and fibulin-3 messenger levels. Fibulin-2 and fibulin-3 expression was colocalized in the subepithelial connective tissue and was distributed along blood and lymphatic vessels. Collagen type III, an immature form of collagen, was increased in the pathologic samples in association with a tissue remodeling process. Conclusions Elastin metabolism is dysregulated in the pathogenesis of human pterygium with tropoelastin, fibulin-2, and fibulin-3 overexpression in the subepithelial connective tissue.Hospital Universitario Príncipe de Asturias (Alcalá de Henares, España)Instituto de Salud Carlos III (Madrid, España)

    Correlates of Colorectal Cancer Screening among Hispanics: Results from the 2008 Puerto Rico Behavioral Risk Factor Surveillance System Survey

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    Introduction—Colorectal cancer (CRC) is the second most commonly diagnosed cancer in Puerto Rico (PR). Given the lack of information on cancer screening behavior, we identified factors associated with CRC screening among adults aged ≥ 50 years in PR. Methods—Age eligible adults who participated in the PR- Behavioral Risk Factor Surveillance System (BRFSS) in 2008 were included in the analysis (n=2,920). Weighted prevalence of fecal occult blood test (FOBT) within two years and of Sigmoidoscopy/Colonoscopy examination within five years before the interview were estimated and logistic regression models were used to assess factors associated with these CRC screening practices. Results—Overall 8.2% (95% CI 7.1%-9.3%) of the participants had had the FOBT within the past two years, 39.8% (95% CI 37.7%-41.9%) had sigmoidoscopy/colonoscopy examination within 5 years and 46.7% (95% CI= 44.5%-48.8%) had ever had any type of CRC screening. Factors positively associated to CRC screening in multivariate analyses included older age, higher education, and having had a routine check-up in the past year. Gender, body mass index, and other relevant covariates evaluated were not associated to screening behavior. Conclusions—Prevalence of CRC screening in PR during 2008 was below the goals established by Healthy People 2010 (50.0%) and 2020 (70.5%). We provide the first population-based estimates of CRC screening prevalence and correlates in a US predominantly Hispanic population. Low adherence to CRC screening may result in late stage at diagnosis and poorer disease outcomes. Public health efforts should focus on the promotion of CRC screening and early detection

    Selection criteria for early breast cancer patients in the DBCG proton trial – The randomised phase III trial strategy

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    Background and purpose Adjuvant radiotherapy of internal mammary nodes (IMN) improves survival in high-risk early breast cancer patients but inevitably leads to more dose to heart and lung. Target coverage is often compromised to meet heart/lung dose constraints. We estimate heart and lung dose when target coverage is not compromised in consecutive patients. These estimates are used to guide the choice of selection criteria for the randomised Danish Breast Cancer Group (DBCG) Proton Trial.Materials and methods 179 breast cancer patients already treated with loco-regional IMN radiotherapy from 18 European departments were included. If the clinically delivered treatment plan did not comply with defined target coverage requirements, the plan was modified retrospectively until sufficient coverage was reached. The choice of selection criteria was based on the estimated number of eligible patients for different heart and lung dose thresholds in combination with proton therapy capacity limitations and dose-response relationships for heart and lung.Results Median mean heart dose was 3.0 Gy (range, 1.1-8.2 Gy) for left-sided and 1.4 Gy (0.4-11.5 Gy) for right-sided treatment plans. Median V17Gy/V20Gy (hypofractionated/normofractionated plans) for ipsilateral lung was 31% (9-57%). The DBCG Radiotherapy Committee chose mean heart dose ≥ 4 Gy and/or lung V17Gy/V20Gy ≥ 37% as thresholds for inclusion in the randomised trial. Using these thresholds, we estimate that 22% of patients requiring loco-regional IMN radiotherapy will be eligible for the trial.Conclusion The patient selection criteria for the DBCG Proton Trial are mean heart dose ≥ 4 Gy and/or lung V17Gy/V20Gy ≥ 37%
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