128 research outputs found

    Propionate and butyrate dependent bacterial sulfate reduction at extremely haloalkaline conditions and description of Desulfobotulus alkaliphilus sp. nov.

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    Evidence on the utilization of simple fatty acids by sulfate-reducing bacteria (SRB) at extremely haloalkaline conditions are practically absent, except for a single case of syntrophy by Desulfonatronum on acetate. Our experiments with sediments from soda lakes of Kulunda Steppe (Altai, Russia) showed sulfide production with sulfate as electron acceptor and propionate and butyrate (but not acetate) as an electron donor at a pH 10–10.5 and a salinity 70–180 g l−1. With propionate as substrate, a highly enriched sulfidogenic culture was obtained in which the main component was identified as a novel representative of the family Syntrophobacteraceae. With butyrate as substrate, a pure SRB culture was isolated which oxidized butyrate and some higher fatty acids incompletely to acetate. The strain represents the first haloalkaliphilic representative of the family Desulfobacteraceae and is described as Desulfobotulus alkaliphilus sp. nov

    Childhood Atopic Diseases and Early Life Circumstances: An Ecological Study in Cuba

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    Background: Children are especially vulnerable during periods of resource shortage such as economic embargoes. They are likely to suffer most from poor nutrition, infectious diseases, and other ensuing short-term threats. Moreover, early life circumstances can have important consequences for long-term health. We examined the relationship between early childhood exposure to the Cuban economic situation in the nineties and the occurrence of atopic diseases later in childhood. Methodology/Principal Findings: A cross-sectional study of 1321 primary schoolchildren aged 4-14 was conducted in two Cuban municipalities. Asthma, allergic rhinoconjunctivitis and atopic dermatitis were diagnosed using the International Study of Asthma and Allergies in Childhood questionnaire. Children were divided into three groups of exposure to the economic situation in the nineties according to birth date: (1) unexposed; (2) exposed during infancy; (3) exposed during infancy and early childhood. Associations were assessed using multiple logistic regression models. Exposure during infancy had a significant inverse association with the occurrence of asthma (OR 0.56, 95% CI 0.33-0.94) and allergic rhinoconjunctivitis (OR 0.46, 95% CI 0.25-0.85). The associations were stronger after longer exposure, i.e. during infancy and early childhood, for asthma (OR 0.40, 95% CI 0.17-0.95) and allergic rhinoconjunctivitis (OR 0.29, 95% CI 0.11-0.77). No significant associations were found for atopic dermatitis. Conclusions/Significance: Exposure to the economic situation in the nineties during infancy and early childhood was inversely associated with asthma and allergic rhinoconjunctivitis occurrence later in childhood. We hypothesize that factors related to this period, such as infectious diseases and undernutrition, may have an attenuating effect on atopic disease development. The exact cause and underlying mechanisms need to be further elucidated

    Impact on the Quality of Life of an Educational Program for the Prevention of Work-Related Musculoskeletal Disorders: a randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Work-related musculoskeletal disorders (WMSD) are a major cause for concern in public health and the main causes of sick leave. Treatments for WMSD have given disappointing results; prevention is the best strategy, but results of preventive measures have not been consistent. To the best of our knowledge there are few studies in literature that evaluated the impact of a specific program aimed at preventing WMSD on the quality of life of employed persons.</p> <p>Methods</p> <p>One hundred and one clerical and production workers in a steel trading company were enrolled in an open-label randomized controlled clinical trial (parallel groups) to compare the efficacy of an educational program for primary prevention of WMSD with control intervention. The primary outcome was a change in the physical functioning domain of the quality of life (QL) measured by Medical Outcomes Study Short Form 36 Health Survey (SF-36). The intervention group underwent six consecutive weekly sessions concerning specific orientations for the prevention of WMSD, while the control group received general health education in an identical schedule. The SF-36 and theses Work Limitation Questionnaire (WLQ) were evaluated at weeks zero, five and 26.</p> <p>Results</p> <p>Baseline characteristics of the interventions groups were comparable, and both groups comprised predominantly young healthy individuals. No significant differences in the variation of the SF-36 and WLQ between the groups were observed at weeks five and 26. However, both groups demonstrated improvement in some aspects of SF-36, suggesting that both educational interventions have beneficial impacts on QL.</p> <p>Conclusions</p> <p>A specific educational program aimed at the preventing of WMSD was comparable with general health orientation for the improvement of QL and work capacity in a sample of healthy workers during a six month period.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00981877">NCT00874718</a></p> <p>Trial Registration</p

    A review of elliptical and disc galaxy structure, and modern scaling laws

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    A century ago, in 1911 and 1913, Plummer and then Reynolds introduced their models to describe the radial distribution of stars in `nebulae'. This article reviews the progress since then, providing both an historical perspective and a contemporary review of the stellar structure of bulges, discs and elliptical galaxies. The quantification of galaxy nuclei, such as central mass deficits and excess nuclear light, plus the structure of dark matter halos and cD galaxy envelopes, are discussed. Issues pertaining to spiral galaxies including dust, bulge-to-disc ratios, bulgeless galaxies, bars and the identification of pseudobulges are also reviewed. An array of modern scaling relations involving sizes, luminosities, surface brightnesses and stellar concentrations are presented, many of which are shown to be curved. These 'redshift zero' relations not only quantify the behavior and nature of galaxies in the Universe today, but are the modern benchmark for evolutionary studies of galaxies, whether based on observations, N-body-simulations or semi-analytical modelling. For example, it is shown that some of the recently discovered compact elliptical galaxies at 1.5 < z < 2.5 may be the bulges of modern disc galaxies.Comment: Condensed version (due to Contract) of an invited review article to appear in "Planets, Stars and Stellar Systems"(www.springer.com/astronomy/book/978-90-481-8818-5). 500+ references incl. many somewhat forgotten, pioneer papers. Original submission to Springer: 07-June-201

    Complete Sequencing and Pan-Genomic Analysis of Lactobacillus delbrueckii subsp. bulgaricus Reveal Its Genetic Basis for Industrial Yogurt Production

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    Lactobacillus delbrueckii subsp. bulgaricus (Lb. bulgaricus) is an important species of Lactic Acid Bacteria (LAB) used for cheese and yogurt fermentation. The genome of Lb. bulgaricus 2038, an industrial strain mainly used for yogurt production, was completely sequenced and compared against the other two ATCC collection strains of the same subspecies. Specific physiological properties of strain 2038, such as lysine biosynthesis, formate production, aspartate-related carbon-skeleton intermediate metabolism, unique EPS synthesis and efficient DNA restriction/modification systems, are all different from those of the collection strains that might benefit the industrial production of yogurt. Other common features shared by Lb. bulgaricus strains, such as efficient protocooperation with Streptococcus thermophilus and lactate production as well as well-equipped stress tolerance mechanisms may account for it being selected originally for yogurt fermentation industry. Multiple lines of evidence suggested that Lb. bulgaricus 2038 was genetically closer to the common ancestor of the subspecies than the other two sequenced collection strains, probably due to a strict industrial maintenance process for strain 2038 that might have halted its genome decay and sustained a gene network suitable for large scale yogurt production

    Upregulation of the Wnt Co-Receptor LRP6 Promotes Hepatocarcinogenesis and Enhances Cell Invasion

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    Background: Activation of the Wnt/b-catenin signaling pathway plays a crucial role in hepatocellular carcinoma (HCC). Lowdensity lipoprotein (LDL) receptor-related protein-6 (LRP6) is one of the co-receptors of the Wnt/b-catenin pathway and forms a signaling complex with Wnt ligand and Frizzled receptor to activate downstream signaling. However, the role of LRP6 in hepatocarcinogenesis is unclear. In this study, we examined its expression and roles in human HCC. Methodology/Principal Findings: Using real-time quantitative RT-PCR, we found that LRP6 was frequently (45%) overexpressed in human HCCs (P = 0.003). In vitro studies showed that ectopic expression of LRP6 increased the protein level of b-catenin. Moreover, overexpression of the full-length and constitutively active LRP6, respectively, activated the WNT/b-catenin signaling pathway, as shown by the TCF/b-catenin reporter assay. With regard to the effects of LRP6 overexpression in HCC cells, stable overexpression of the constitutively active LRP6 in BEL-7402 HCC cells enhanced cell proliferation, cell migration, and invasion in vitro as well as tumorigenicity in nude mice. Conclusions/Significance: Our findings indicate that overexpression of LRP6 contributes to the hyperactivation of the Wnt

    Comparative Functional Genomics Analysis of NNK Tobacco-Carcinogen Induced Lung Adenocarcinoma Development in Gprc5a-Knockout Mice

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    Background: Improved understanding of lung cancer development and progression, including insights from studies of animal models, are needed to combat this fatal disease. Previously, we found that mice with a knockout (KO) of G-protein coupled receptor 5A (Gprc5a) develop lung tumors after a long latent period (12 to 24 months). Methodology/Principal Findings: To determine whether a tobacco carcinogen will enhance tumorigenesis in this model, we administered 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) i.p. to 2-months old Gprc5a-KO mice and sacrificed groups (n = 5) of mice at 6, 9, 12, and 18 months later. Compared to control Gprc5a-KO mice, NNK-treated mice developed lung tumors at least 6 months earlier, exhibited 2- to 4-fold increased tumor incidence and multiplicity, and showed a dramatic increase in lesion size. A gene expression signature, NNK-ADC, of differentially expressed genes derived by transcriptome analysis of epithelial cell lines from normal lungs of Gprc5a-KO mice and from NNK-induced adenocarcinoma was highly similar to differential expression patterns observed between normal and tumorigenic human lung cells. The NNK-ADC expression signature also separated both mouse and human adenocarcinomas from adjacent normal lung tissues based on publicly available microarray datasets. A key feature of the signature, up-regulation of Ube2c, Mcm2, and Fen1, was validated in mouse normal lung and adenocarcinoma tissues and cells by immunohistochemistry and western blotting, respectively

    A broader role for AmyR in Aspergillus niger: regulation of the utilisation of d-glucose or d-galactose containing oligo- and polysaccharides

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    AmyR is commonly considered a regulator of starch degradation whose activity is induced by the presence of maltose, the disaccharide building block of starch. In this study, we demonstrate that the role of AmyR extends beyond starch degradation. Enzyme activity assays, genes expression analysis and growth profiling on d-glucose- and d-galactose-containing oligo- and polysaccharides showed that AmyR regulates the expression of some of the Aspergillus niger genes encoding α- and β-glucosidases, α- and β- galactosidases, as well as genes encoding α-amlyases and glucoamylases. In addition, we provide evidence that d-glucose or a metabolic product thereof may be the inducer of the AmyR system in A. niger and not maltose, as is commonly assumed

    K-ras mutations in sinonasal cancers in relation to wood dust exposure

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    <p>Abstract</p> <p>Background</p> <p>Cancer in the sinonasal tract is rare, but persons who have been occupationally exposed to wood dust have a substantially increased risk. It has been estimated that approximately 3.6 million workers are exposed to inhalable wood dust in EU. In previous small studies of this cancer, <it>ras </it>mutations were suggested to be related to wood dust exposure, but these studies were too limited to detect statistically significant associations.</p> <p>Methods</p> <p>We examined 174 cases of sinonasal cancer diagnosed in Denmark in the period from 1991 to 2001. To ensure uniformity, all histological diagnoses were carefully reviewed pathologically before inclusion. Paraffin embedded tumour samples from 58 adenocarcinomas, 109 squamous cell carcinomas and 7 other carcinomas were analysed for K-<it>ras </it>codon 12, 13 and 61 point mutations by restriction fragment length polymorphisms and direct sequencing. Information on occupational exposure to wood dust and to potential confounders was obtained from telephone interviews and from registry data.</p> <p>Results</p> <p>Among the patients in this study, exposure to wood dust was associated with a 21-fold increased risk of having an adenocarcinoma than a squamous cell carcinoma compared to unexposed [OR = 21.0, CI = 8.0–55.0]. K-<it>ras </it>was mutated in 13% of the adenocarcinomas (seven patients) and in 1% of squamous cell carcinomas (one patient). Of these eight mutations, five mutations were located in the codon 12. The exact sequence change of remaining three could not be identified unambiguously. Among the five identified mutations, the G→A transition was the most common, and it was present in tumour tissue from two wood dust exposed adenocarcinoma patients and one patient with unknown exposure. Previously published studies of sinonasal cancer also identify the GGT → GAT transition as the most common and often related to wood dust exposure.</p> <p>Conclusion</p> <p>Patients exposed to wood dust seemed more likely to develop adenocarcinoma compared to squamous cell carcinomas. K-<it>ras </it>mutations were detected in 13% of adenocarcinomas. In this study and previously published studies of sinonasal cancer the found K-<it>ras </it>mutations, were almost exclusively G → A transitions. In conclusion, our study, based on a large representative collection of human SNC tumours, indicates that K-<it>ras </it>mutations are relatively infrequent, and most commonly occur in adenocarcinomas. Wood dust exposure alone was not found to be explanatory for the G→A mutations, but combination of exposure to tobacco, wood dust, and possibly other occupational agents may be a more likely explanation. Overall, the study suggests a limited role for K-<it>ras </it>mutations in development of sinonasal cancer.</p
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