473 research outputs found

    Early replication in pulmonary B cells after infection with marek's disease herpesvirus by the respiratory route

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    Natural infection with Marek's disease virus occurs through the respiratory mucosa after chickens inhale dander shed from infected chickens. The early events in the lung following exposure to the feather and squamous epithelial cell debris containing the viral particles remain unclear. In order to elucidate the virological and immunological consequences of MDV infection for the respiratory tract, chickens were infected by intratracheal administration of infective dander. Differences between susceptible and resistant chickens were immediately apparent, with delayed viral replication and earlier onset of interferon (IFN)-γ production in the latter. CD4+ and CD8 + T cells surrounded infected cells in the lung. Although viral replication was evident in macrophages, pulmonary B cells were the main target cell type in susceptible chickens following intratracheal infection with MDV. In accordance, depletion of B cells curtailed viremia and substantially affected pathogenesis in susceptible chickens. Together the data described here demonstrate the role of pulmonary B cells as the primary and predominant target cells and their importance for MDV pathogenesis. © 2009, Mary Ann Liebert, Inc.

    Large introns in relation to alternative splicing and gene evolution: a case study of Drosophila bruno-3

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    Background: Alternative splicing (AS) of maturing mRNA can generate structurally and functionally distinct transcripts from the same gene. Recent bioinformatic analyses of available genome databases inferred a positive correlation between intron length and AS. To study the interplay between intron length and AS empirically and in more detail, we analyzed the diversity of alternatively spliced transcripts (ASTs) in the Drosophila RNA-binding Bruno-3 (Bru-3) gene. This gene was known to encode thirteen exons separated by introns of diverse sizes, ranging from 71 to 41,973 nucleotides in D. melanogaster. Although Bru-3's structure is expected to be conducive to AS, only two ASTs of this gene were previously described. Results: Cloning of RT-PCR products of the entire ORF from four species representing three diverged Drosophila lineages provided an evolutionary perspective, high sensitivity, and long-range contiguity of splice choices currently unattainable by high-throughput methods. Consequently, we identified three new exons, a new exon fragment and thirty-three previously unknown ASTs of Bru-3. All exon-skipping events in the gene were mapped to the exons surrounded by introns of at least 800 nucleotides, whereas exons split by introns of less than 250 nucleotides were always spliced contiguously in mRNA. Cases of exon loss and creation during Bru-3 evolution in Drosophila were also localized within large introns. Notably, we identified a true de novo exon gain: exon 8 was created along the lineage of the obscura group from intronic sequence between cryptic splice sites conserved among all Drosophila species surveyed. Exon 8 was included in mature mRNA by the species representing all the major branches of the obscura group. To our knowledge, the origin of exon 8 is the first documented case of exonization of intronic sequence outside vertebrates. Conclusion: We found that large introns can promote AS via exon-skipping and exon turnover during evolution likely due to frequent errors in their removal from maturing mRNA. Large introns could be a reservoir of genetic diversity, because they have a greater number of mutable sites than short introns. Taken together, gene structure can constrain and/or promote gene evolution

    Psychological impact, support and information needs for women with an abnormal Pap smear: comparative results of a questionnaire in three European countries

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    <p>Abstract</p> <p>Background</p> <p>Extensive information on cervical cancer is currently available. Its effectiveness in reducing anxiety in women receiving abnormal Pap tests is not clear. We investigated current practices of communicating abnormal Pap results to evaluate women's reactions and determine the sources of information they use subsequently.</p> <p>Methods</p> <p>A self-administered questionnaire-based study was performed in 1475 women in France, Spain and Portugal who had received an abnormal Pap smear result in the 12 months prior to completing the questionnaire. Questions covered methods of communication of the result, emotional reactions, support received (from the physician and entourage), and information sources, using pre-specified check box options and rating scales. Data were analyzed by country.</p> <p>Results</p> <p>Pap test results were mostly communicated by phone to Spanish women (76%), while physician letters were common in France (59%) and Portugal (36%). Frequent reactions were anxiety, panic and stress, which were less common in Spanish women than their French and Portuguese counterparts. After discussing with their physician, half of the participants were worried, despite rating highly the psychological support received. Over 90% of women in each country discussed their results with family or friends. Partners provided a high level of support. Overall, the abnormal diagnosis and consequences had a low to medium impact on daily, professional and family life and their relationships with their partner. Impact was higher in Spanish women than the French or Portuguese. Information on the diagnosis and its treatment was rated average, and nearly 80% of participants wanted more information, notably French women. Preferred sources were the physician and the Internet.</p> <p>Conclusions</p> <p>Women expressed a strong wish for more information about cervical cancer and other HPV-related diseases, and that their physician play a major role in its provision and in support. There was a heavy reliance on the close entourage and the Internet for information, highlighting the need for dissemination of accurate material. Differences between countries suggest information management strategies may need to be tailored to different geographical regions.</p

    Tandem repeat distribution of gene transcripts in three plant families

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    Tandem repeats (microsatellites or SSRs) are molecular markers with great potential for plant genetic studies. Modern strategies include the transfer of these markers among widely studied and orphan species. In silico analyses allow for studying distribution patterns of microsatellites and predicting which motifs would be more amenable to interspecies transfer. Transcribed sequences (Unigene) from ten species of three plant families were surveyed for the occurrence of micro and minisatellites. Transcripts from different species displayed different rates of tandem repeat occurrence, ranging from 1.47% to 11.28%. Both similar and different patterns were found within and among plant families. The results also indicate a lack of association between genome size and tandem repeat fractions in expressed regions. The conservation of motifs among species and its implication on genome evolution and dynamics are discussed

    Media coverage of the Zika crisis in Brazil: the construction of a 'war' frame that masked social and gender inequalities

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    Between 2015 and 2016, Zika became an epidemic of global concern and the focus of intense media coverage. Using a hybrid model of frame and social representations theory, we examine how the Zika outbreak was reported in two major newspapers in Brazil: O Globo and Folha de São Paulo. The analysis of 186 articles published between December 2015 and May 2016 reveals a dominant ‘war’ frame supported by two sub-frames: one focused on eradicating the vector (mosquito) and another on controlling microcephaly, placing the burden of prevention on women. Scientific uncertainties about the virus and its relationship to microcephaly coupled with political uncertainties in Brazil increased the power of the war frame. This frame gave prominence and legitimacy to certain representations of disease management during the crisis, masking social and gender inequalities. We show how the cartography of the disease overlaps with that of poverty and regional inequality in Brazil to argue that addressing socio-economic aspects is essential, but normally neglected, in media communications during disease outbreaks like Zika

    Nucleon-Nucleon Interaction: A Typical/Concise Review

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    Nearly a recent century of work is divided to Nucleon-Nucleon (NN) interaction issue. We review some overall perspectives of NN interaction with a brief discussion about deuteron, general structure and symmetries of NN Lagrangian as well as equations of motion and solutions. Meanwhile, the main NN interaction models, as frameworks to build NN potentials, are reviewed concisely. We try to include and study almost all well-known potentials in a similar way, discuss more on various commonly used plain forms for two-nucleon interaction with an emphasis on the phenomenological and meson-exchange potentials as well as the constituent-quark potentials and new ones based on chiral effective field theory and working in coordinate-space mostly. The potentials are constructed in a way that fit NN scattering data, phase shifts, and are also compared in this way usually. An extra goal of this study is to start comparing various potentials forms in a unified manner. So, we also comment on the advantages and disadvantages of the models and potentials partly with reference to some relevant works and probable future studies.Comment: 85 pages, 5 figures, than the previous v3 edition, minor changes, and typos fixe

    Dissecting the transcriptional networks underlying breast cancer: NR4A1 reduces the migration of normal and breast cancer cell lines

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    Introduction: Breast cancer currently accounts for more than one-quarter of all female cancers and, despite the great progress in treatment observed in the past few years, the need for identification of new gene targets that can be used for diagnosis, prognosis and therapy is evident. A previous study identified the transcription factor NR4A1 as a gene upregulated in primary breast cancer compared with normal tissue by microarray analysis and sequencing technologies. The purpose of the study was to identify the role of NR4A1 in normal mammary epithelial and breast cancer cell biology.Methods: NR4A1 expression in breast tumours was assessed by semiquantitative and real-time PCR using RNA from normal and tumour samples or breast cancer cell lines. Immunohistochemistry on tissue microarrays was performed to check NR4A1 protein expression in breast tumours. MCF-10A and 226L normal mammary epithelial cells as well as the tumour lines PMC42, ZR-75-1 and MDA-MB-231 were transduced with full-length NR4A1, and the ability of NR4A1-overexpressing cells to migrate was tested using scratch wound or transwell migration assays. Proliferation was measured using the MTT and BrdU assays, while apoptosis was determined by the Annexin V assay. The ability of the cells to adhere to extracellular matrix was tested by adhesion assays and integrin cell surface expression was measured by flow cytometry. Activation of the FAK as well as ERK1/2 and PI3K pathways was checked by western blotting.Results: Breast tissue microarray analysis showed NR4A1 expression in primary tumours, which was reduced in higher grade and metastatic tumours. Ectopic expression of NR4A1 in MCF-10A, 226L, PMC42 and ZR-75-1 cells led to reduced ability of the cells to migrate, while no differences were observed in their proliferation and apoptotic index. NR4A1 expression altered the ability of the MCF-10A cells to adhere to the extracellular matrix and affected cell surface expression of integrins.Conclusions: NR4A1 acts as an antimigratory factor in two normal mammary epithelial and two breast cancer cell lines tested. It is therefore possible that NR4A1 acts as an antimigratory factor in breast tumours, and further studies should be conducted to understand the mechanisms involved

    Glucose Depletion in the Airway Surface Liquid Is Essential for Sterility of the Airways

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    Diabetes mellitus predisposes the host to bacterial infections. Moreover, hyperglycemia has been shown to be an independent risk factor for respiratory infections. The luminal surface of airway epithelia is covered by a thin layer of airway surface liquid (ASL) and is normally sterile despite constant exposure to bacteria. The balance between bacterial growth and killing in the airway determines the outcome of exposure to inhaled or aspirated bacteria: infection or sterility. We hypothesized that restriction of carbon sources –including glucose– in the ASL is required for sterility of the lungs. We found that airway epithelia deplete glucose from the ASL via a novel mechanism involving polarized expression of GLUT-1 and GLUT-10, intracellular glucose phosphorylation, and low relative paracellular glucose permeability in well-differentiated cultures of human airway epithelia and in segments of airway epithelia excised from human tracheas. Moreover, we found that increased glucose concentration in the ASL augments growth of P. aeruginosa in vitro and in the lungs of hyperglycemic ob/ob and db/db mice in vivo. In contrast, hyperglycemia had no effect on intrapulmonary bacterial growth of a P. aeruginosa mutant that is unable to utilize glucose as a carbon source. Our data suggest that depletion of glucose in the airway epithelial surface is a novel mechanism for innate immunity. This mechanism is important for sterility of the airways and has implications in hyperglycemia and conditions that result in disruption of the epithelial barrier in the lung

    NR4A Gene Expression Is Dynamically Regulated in the Ventral Tegmental Area Dopamine Neurons and Is Related to Expression of Dopamine Neurotransmission Genes

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    The NR4A transcription factors NR4A1, NR4A2, and NR4A3 (also known as Nur77, Nurr1, and Nor1, respectively) share similar DNA-binding properties and have been implicated in regulation of dopamine neurotransmission genes. Our current hypothesis is that NR4A gene expression is regulated by dopamine neuron activity and that induction of NR4A genes will increase expression of dopamine neurotransmission genes. Eticlopride and γ-butyrolactone (GBL) were used in wild-type (+/+) and Nurr1-null heterozygous (+/−) mice to determine the mechanism(s) regulating Nur77 and Nurr1 expression. Laser capture microdissection and real-time PCR was used to measure Nurr1 and Nur77 mRNA levels in the ventral tegmental area (VTA). Nur77 expression was significantly elevated 1 h after both GBL (twofold) and eticlopride (fourfold). In contrast, GBL significantly decreased Nurr1 expression in both genotypes, while eticlopride significantly increased Nurr1 expression only in the +/+ mice. In a separate group of mice, haloperidol injection significantly elevated Nur77 and Nor1, but not Nurr1 mRNA in the VTA within 1 h and significantly increased tyrosine hydroxylase (TH) and dopamine transporter (DAT) mRNA expression by 4 h. These data demonstrate that the NR4A genes are dynamically regulated in dopamine neurons with maintenance of Nurr1 expression requiring dopamine neuron activity while both attenuation of dopamine autoreceptors activation and dopamine neuronal activity combining to induce Nur77 expression. Additionally, these data suggest that induction of NR4A genes could regulate TH and DAT expression and ultimately regulate dopamine neurotransmission
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