4,239 research outputs found

    Autoregulation of the Escherichia coli melR promoter: repression involves four molecules of MelR

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    The Escherichia coli MelR protein is a transcription activator that autoregulates its own promoter by repressing transcription initiation. Optimal repression requires MelR binding to a site that overlaps the melR transcription start point and to upstream sites. In this work, we have investigated the different determinants needed for optimal repression and their spatial requirements. We show that repression requires a complex involving four DNA-bound MelR molecules, and that the global CRP regulator plays little or no role

    An integrated general practice and pharmacy-based intervention to promote the use of appropriate preventive medications among individuals at high cardiovascular disease risk: protocol for a cluster randomized controlled trial

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    Background: Cardiovascular diseases (CVD) are responsible for significant morbidity, premature mortality, and economic burden. Despite established evidence that supports the use of preventive medications among patients at high CVD risk, treatment gaps remain. Building on prior evidence and a theoretical framework, a complex intervention has been designed to address these gaps among high-risk, under-treated patients in the Australian primary care setting. This intervention comprises a general practice quality improvement tool incorporating clinical decision support and audit/feedback capabilities; availability of a range of CVD polypills (fixed-dose combinations of two blood pressure lowering agents, a statin ± aspirin) for prescription when appropriate; and access to a pharmacy-based program to support long-term medication adherence and lifestyle modification. Methods: Following a systematic development process, the intervention will be evaluated in a pragmatic cluster randomized controlled trial including 70 general practices for a median period of 18 months. The 35 general practices in the intervention group will work with a nominated partner pharmacy, whereas those in the control group will provide usual care without access to the intervention tools. The primary outcome is the proportion of patients at high CVD risk who were inadequately treated at baseline who achieve target blood pressure (BP) and low-density lipoprotein cholesterol (LDL-C) levels at the study end. The outcomes will be analyzed using data from electronic medical records, utilizing a validated extraction tool. Detailed process and economic evaluations will also be performed. Discussion: The study intends to establish evidence about an intervention that combines technological innovation with team collaboration between patients, pharmacists, and general practitioners (GPs) for CVD prevention. Trial registration: Australian New Zealand Clinical Trials Registry ACTRN1261600023342

    Single-base substitutions in the CHM promoter as a cause of choroideremia

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    Although over 150 unique mutations affecting the coding sequence of CHM have been identified in patients with the X-linked chorioretinal disease choroideremia (CHM), no regulatory mutations have been reported, and indeed the promoter has not been defined. Here, we describe two independent families affected by CHM bearing a mutation outside the gene's coding region at position c.-98: C>A and C>T, which segregated with the disease. The male proband of family 1 was found to lack CHM mRNA and its gene product Rab escort protein 1, whereas whole-genome sequencing of an affected male in family 2 excluded the involvement of any other known retinal genes. Both mutations abrogated luciferase activity when inserted into a reporter construct, and by further employing the luciferase reporter system to assay sequences 5′ to the gene, we identified the CHM promoter as the region encompassing nucleotides c.-119 to c.-76. These findings suggest that the CHM promoter region should be examined in patients with CHM who lack coding sequence mutations, and reveals, for the first time, features of the gene's regulation

    Multicellular Architecture of Malignant Breast Epithelia Influences Mechanics

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    Cell–matrix and cell–cell mechanosensing are important in many cellular processes, particularly for epithelial cells. A crucial question, which remains unexplored, is how the mechanical microenvironment is altered as a result of changes to multicellular tissue structure during cancer progression. In this study, we investigated the influence of the multicellular tissue architecture on mechanical properties of the epithelial component of the mammary acinus. Using creep compression tests on multicellular breast epithelial structures, we found that pre-malignant acini with no lumen (MCF10AT) were significantly stiffer than normal hollow acini (MCF10A) by 60%. This difference depended on structural changes in the pre-malignant acini, as neither single cells nor normal multicellular acini tested before lumen formation exhibited these differences. To understand these differences, we simulated the deformation of the acini with different multicellular architectures and calculated their mechanical properties; our results suggest that lumen filling alone can explain the experimentally observed stiffness increase. We also simulated a single contracting cell in different multicellular architectures and found that lumen filling led to a 20% increase in the “perceived stiffness” of a single contracting cell independent of any changes to matrix mechanics. Our results suggest that lumen filling in carcinogenesis alters the mechanical microenvironment in multicellular epithelial structures, a phenotype that may cause downstream disruptions to mechanosensing

    The determinants of hotels' marketing managers' green marketing behaviour

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    Little is known about the factors underlying the pro-environmental behaviour of marketing managers. This paper explores the determinants of green marketing practices in the Red Sea hotel sector in Egypt. The research model assesses green marketing practices against the personal and organisational values of the marketing managers, together with a range of organisational and demographic variables expected to influence hotels' environmental behaviour. From a valid sample of 89 marketing managers responsible for 194 hotels, it was found that organisational contextual variables, and in particular targeting Western tourists, being affiliated to an international hotel chain and the marketers' own demographics, including age, academic subject studied and gender, were the best predictors of more proactive green marketing. Personal environmental values did not explain the pro-environmental behaviour of marketers, and the organisational environmental values that had explained part of their ethical behaviour had resulted from voluntarism rather than utilitarian or conformance-based values. Government policies also appeared to be ineffective determinants. The implications for green marketing practices are also discussed. © 2010 Taylor & Francis

    Pre-cooling for endurance exercise performance in the heat: a systematic review.

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    PMCID: PMC3568721The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1741-7015/10/166. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Endurance exercise capacity diminishes under hot environmental conditions. Time to exhaustion can be increased by lowering body temperature prior to exercise (pre-cooling). This systematic literature review synthesizes the current findings of the effects of pre-cooling on endurance exercise performance, providing guidance for clinical practice and further research

    Enhanced formation of giant cells in common variable immunodeficiency: Relation to granulomatous disease.

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    Peripheral monocytes from patients with common variable immunodeficiency (CVID) had on average a 2 fold greater tendency to form giant cells in medium without additional cytokines. Giant cell formation was faster and 3 to 5 fold higher in most CVID cells compared to normal. Addition of IL4, GMCSF, IFNγ, TNFa and both T cell and monocyte conditioned media promoted monocyte fusion of some CVID individuals over 5 fold the normal average level, with combinations of cytokines and monokines acting synergistically. The reduction of normal giant cell formation by anti-IFNγ antibody and a greater tendency of CVID cells to fuse in immunoglobulin conditioned media suggests that standard IVIg treatment contributes to granuloma formation. CVID and normal giant cells expressed similar levels of phenotypic molecules and had similar phagocytic activity. Monocytes from many CVID patients have an elevated tendency to fuse which may explain the high incidence of granulomatous complications in CVID

    Contribution of microscopy for understanding the mechanism of action against trypanosomatids

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    Transmission electron microscopy (TEM) has proved to be a useful tool to study the ultrastructural alterations and the target organelles of new antitrypanosomatid drugs. Thus, it has been observed that sesquiterpene lactones induce diverse ultrastructural alterations in both T. cruzi and Leishmania spp., such as cytoplasmic vacuolization, appearance of multilamellar structures, condensation of nuclear DNA, and, in some cases, an important accumulation of lipid vacuoles. This accumulation could be related to apoptotic events. Some of the sesquiterpene lactones (e.g., psilostachyin) have also been demonstrated to cause an intense mitochondrial swelling accompanied by a visible kinetoplast deformation as well as the appearance of multivesicular bodies. This mitochondrial swelling could be related to the generation of oxidative stress and associated to alterations in the ergosterol metabolism. The appearance of multilamellar structures and multiple kinetoplasts and flagella induced by the sesquiterpene lactone psilostachyin C indicates that this compound would act at the parasite cell cycle level, in an intermediate stage between kinetoplast segregation and nuclear division. In turn, the diterpene lactone icetexane has proved to induce the external membrane budding on T. cruzi together with an apparent disorganization of the pericellar cytoskeleton. Thus, ultrastructural TEM studies allow elucidating the possible mechanisms and the subsequent identification of molecular targets for the action of natural compounds on trypanosomatids.Fil: Lozano, Esteban Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Spina Zapata, Renata María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Barrera, Patricia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Tonn, Carlos Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Sosa Escudero, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentin

    Fecal occult blood and fecal calprotectin as point-of-care markers of intestinal morbidity in Ugandan children with Schistosoma mansoni infection.

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    BACKGROUND: Calprotectin is a calcium-binding cytoplasmic protein found in neutrophils and increasingly used as a marker of bowel inflammation. Fecal occult blood (FOB) is also a dependable indicator of bowel morbidity. The objective of our study was to determine the applicability of these tests as surrogate markers of Schistosoma mansoni intestinal morbidity before and after treatment with praziquantel (PZQ). METHODS: 216 children (ages 3-9 years old) from Buliisa District in Lake Albert, Uganda were examined and treated with PZQ at baseline in October 2012 with 211 of them re-examined 24 days later for S. mansoni and other soil transmitted helminths (STH). POC calprotectin and FOB assays were performed at both time points on a subset of children. Associations between the test results and infection were analysed by logistic regression. RESULTS: Fecal calprotectin concentrations of 150-300 µg/g were associated with S. mansoni egg patent infection both at baseline and follow up (OR: 12.5 P = 0.05; OR: 6.8 P = 0.02). FOB had a very strong association with baseline anemia (OR: 9.2 P = 0.03) and medium and high egg intensity schistosomiasis at follow up (OR: 6.6 P = 0.03; OR: 51.3 P = 0.003). Both tests were strongly associated with heavy intensity S. mansoni infections. There was a significant decrease in FOB and calprotectin test positivity after PZQ treatment in those children who had egg patent schistosomiasis at baseline. CONCLUSIONS: Both FOB and calprotectin rapid assays were found to correlate positively and strongly with egg patent S. mansoni infection with a positive ameloriation response after PZQ treatment indicative of short term reversion of morbidity. Both tests were appropriate for use in the field with excellent operational performance and reliability. Due to its lower-cost which makes its scale-up of use affordable, FOB could be immediately adopted as a monitoring tool for PC campaigns for efficacy evaluation before and after treatment

    Variation in centre-specific survival in patients starting renal replacement therapy in England is explained by enhanced comorbidity information from hospitalization data

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    Background Unadjusted survival on renal replacement therapy (RRT) varies widely from centre to centre in England. Until now, missing data on case mix have made it impossible to determine whether this variation reflects genuine differences in the quality of care. Data linkage has the capacity to reduce missing data. Methods Modelling of survival using Cox proportional hazards of data returned to the UK Renal Registry on patients starting RRT for established renal failure in England. Data on ethnicity, socioeconomic status and comorbidity were obtained by linkage to the Hospital Episode Statistics database, using data from hospitalizations prior to starting RRT. Results Patients with missing data were reduced from 61 to 4%. The prevalence of comorbid conditions was remarkably similar across centres. When centre-specific survival was compared after adjustment solely for age, survival was below the 95% limit for 6 of 46 centres. The addition of variables into the multivariable model altered the number of centres that appeared to be ‘outliers’ with worse than expected survival as follows: ethnic origin four outliers, socioeconomic status eight outliers and year of the start of RRT four outliers. The addition of a combination of 16 comorbid conditions present at the start of RRT reduced the number of centres with worse than expected survival to one. Conclusions Linked data between a national registry and hospital admission dramatically reduced missing data, and allowed us to show that nearly all the variation between English renal centres in 3-year survival on RRT was explained by demographic factors and by comorbidity
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