532 research outputs found

    Utilization of a ts-sacB selection system for the generation of a Mycobacterium avium serovar-8 specific glycopeptidolipid allelic exchange mutant

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    BACKGROUND: Mycobacterium avium are ubiquitous environmental organisms and a cause of disseminated infection in patients with end-stage AIDS. The glycopeptidolipids (GPL) of M. avium are proposed to participate in the pathogenesis of this organism, however, establishment of a clear role for GPL in disease production has been limited by the inability to genetically manipulate M. avium. METHODS: To be able to study the role of the GPL in M. avium pathogenesis, a ts-sacB selection system, not previously used in M. avium, was employed as a means to achieve homologous recombination for the rhamnosyltransferase (rtfA) gene of a pathogenic serovar 8 strain of M. avium to prevent addition of serovar-specific sugars to rhamnose of the fatty acyl-peptide backbone of GPL. The genotype of the resultant rtfA mutant was confirmed by polymerase chain reaction and southern hybridization. Disruption in the proximal sugar of the haptenic oligosaccharide resulted in the loss of serovar specific GPL with no change in the pattern of non-serovar specific GPL moieties as shown by thin layer chromatography and gas chromatography/mass spectrometry. Complementation of wild type (wt) rtfA in trans through an integrative plasmid restored serovar-8 specific GPL expression identical to wt serovar 8 parent strain. RESULTS: In this study, we affirm our results that rtfA encodes an enzyme responsible for the transfer of Rha to 6d-Tal and provide evidence of a second allelic exchange mutagenesis system suitable for M. avium. CONCLUSION: We report the second allelic exchange system for M. avium utilizing ts-sacB as double-negative and xylE as positive counter-selection markers, respectively. This system of allelic exchange would be especially useful for M. avium strains that demonstrate significant isoniazid (INH) resistance despite transformation with katG. Through the construction of mutants in GPL or other mycobacterial components, their roles in M. avium pathogenesis, biosynthesis, or drug resistance can be studied in a consistent manner

    Silent Phase of Johne’s Disease in Experimentally Infected Goats – A Study on New and Established Diagnostic Approaches Using Specific and Non-Specific Parameters

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    The current gold standard diagnostic test for Johne’s disease (JD) is detecting Mycobacterium avium subsp. paratuberculosis (MAP) from fecal samples via culture and/or PCR. Other commercially available JD diagnostic tests focus on the detection of specific antibodies within the serum or milk of infected ruminants. These tests have a high specificity but low their sensitivity and usually fail to diagnose the disease until later stages of the disease. The ideal diagnostic test should detect infected animals already during the silent phase. Here, we evaluate the use of new and established approaches to define the silent phase of JD in experimentally infected goats. None of the established diagnostic tests or new approaches for the detection of humoral and cellular immune responses were positive during the first year of infection. Only the characterization of various subsets of peripheral blood leukocytes and the weight development gave some indication for the presence of a chronic, but silent, infection. Weight differences were present throughout the first year. In addition, some of the subsets of leukocytes (WC1+ T cells, MHC class II+ leukocytes, CD1+ leukocytes, CD14+ granulocytes, and CD14+/MHC class II+ granulocytes) demonstrated significant differences, but only at certain time points

    Polar Lipids of Burkholderia pseudomallei Induce Different Host Immune Responses

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    Melioidosis is a disease in tropical and subtropical regions of the world that is caused by Burkholderia pseudomallei. In endemic regions the disease occurs primarily in humans and goats. In the present study, we used the goat as a model to dissect the polar lipids of B. pseudomallei to identify lipid molecules that could be used for adjuvants/vaccines or as diagnostic tools. We showed that the lipidome of B. pseudomallei and its fractions contain several polar lipids with the capacity to elicit different immune responses in goats, namely rhamnolipids and ornithine lipids which induced IFN-γ, whereas phospholipids and an undefined polar lipid induced strong IL-10 secretion in CD4(+) T cells. Autologous T cells co-cultured with caprine dendritic cells (cDCs) and polar lipids of B. pseudomallei proliferated and up-regulated the expression of CD25 (IL-2 receptor) molecules. Furthermore, we demonstrated that polar lipids were able to up-regulate CD1w2 antigen expression in cDCs derived from peripheral blood monocytes. Interestingly, the same polar lipids had only little effect on the expression of MHC class II DR antigens in the same caprine dendritic cells. Finally, antibody blocking of the CD1w2 molecules on cDCs resulted in decreased expression for IFN-γ by CD4(+) T cells. Altogether, these results showed that polar lipids of B. pseudomallei are recognized by the caprine immune system and that their recognition is primarily mediated by the CD1 antigen cluster

    Resolution of Crohn\u27s disease and complex regional pain syndrome following treatment of paratuberculosis

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    A cohort of family members with various chronic diseases including Crohn\u27s disease, asthma, complex regional pain syndrome, hypothyroidism, type 1 diabetes mellitus, and lymphangiomatosis and/or evidence of infection by Mycobacterium avium subsp. paratuberculosis (MAP) are described in this series of case reports. MAP was cultured from the blood of three members affected by the first five diseases and there was accompanying elevated anti-MAP IgG in two members. The patient affected by the sixth disease has a markedly elevated anti-MAP titer. The two patients affected by the first four diseases have been treated with a combination of anti-MAP antibiotics and ultraviolet blood irradiation therapy with resolution of the disease symptomatology and inability to culture MAP in post treatment blood samples. These case reports of patients with MAP infections provide supportive evidence of a pathogenic role of MAP in humans

    In Search for a Credit Crunch in Germany

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    The purpose of this paper is to investigate whether a credit crunch occurred in Germany during the recent financial crisis and to analyze the underlying factors. In order to disentangle credit supply and demand we specify a theory-based dynamic disequilibrium model of the German credit market. To estimate this model we use a new approach based on Bayesian Inference suggested by Bauwens and Lubrano (2007). Besides the analysis of the whole banking sector we will apply the model to five groups of banks (big private banks, Landesbanken, savings banks, credit cooperatives, regional institutions of credit cooperatives) that were affected differently by the financial crisis. The results suggest that a credit crunch did not occur in Germany during the recent economic crisis as well as during the following recovery starting in 2010. Furthermore, we find that especially those banks that were more affected by the financial crisis through huge impairments restricted their credit supply more than others. Both supply and demand side factors contributed to the stabilization of credit financing. This suggests that the structure of the German banking sector as well as economic policy measures avoided a credit crunch

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

    Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

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    One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

    Search for stop and higgsino production using diphoton Higgs boson decays

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    Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top-quark (stop) and the Higgs boson (higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 inverse femtobarns of proton-proton collision data at sqrt(s) = 8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the stop mass below 360 to 410 GeV, depending on the higgsino mass
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