50 research outputs found

    Chemoattractant Signaling between Tumor Cells and Macrophages Regulates Cancer Cell Migration, Metastasis and Neovascularization

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    Tumor-associated macrophages are known to influence cancer progression by modulation of immune function, angiogenesis, and cell metastasis, however, little is known about the chemokine signaling networks that regulate this process. Utilizing CT26 colon cancer cells and RAW 264.7 macrophages as a model cellular system, we demonstrate that treatment of CT26 cells with RAW 264.7 conditioned medium induces cell migration, invasion and metastasis. Inflammatory gene microarray analysis indicated CT26-stimulated RAW 264.7 macrophages upregulate SDF-1α and VEGF, and that these cytokines contribute to CT26 migration in vitro. RAW 264.7 macrophages also showed a robust chemotactic response towards CT26-derived chemokines. In particular, microarray analysis and functional testing revealed CSF-1 as the major chemoattractant for RAW 264.7 macrophages. Interestingly, in the chick CAM model of cancer progression, RAW 264.7 macrophages localized specifically to the tumor periphery where they were found to increase CT26 tumor growth, microvascular density, vascular disruption, and lung metastasis, suggesting these cells home to actively invading areas of the tumor, but not the hypoxic core of the tumor mass. In support of these findings, hypoxic conditions down regulated CSF-1 production in several tumor cell lines and decreased RAW 264.7 macrophage migration in vitro. Together our findings suggest a model where normoxic tumor cells release CSF-1 to recruit macrophages to the tumor periphery where they secrete motility and angiogenic factors that facilitate tumor cell invasion and metastasis

    The Structural Biology Knowledgebase: a portal to protein structures, sequences, functions, and methods

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    The Protein Structure Initiative’s Structural Biology Knowledgebase (SBKB, URL: http://sbkb.org) is an open web resource designed to turn the products of the structural genomics and structural biology efforts into knowledge that can be used by the biological community to understand living systems and disease. Here we will present examples on how to use the SBKB to enable biological research. For example, a protein sequence or Protein Data Bank (PDB) structure ID search will provide a list of related protein structures in the PDB, associated biological descriptions (annotations), homology models, structural genomics protein target status, experimental protocols, and the ability to order available DNA clones from the PSI:Biology-Materials Repository. A text search will find publication and technology reports resulting from the PSI’s high-throughput research efforts. Web tools that aid in research, including a system that accepts protein structure requests from the community, will also be described. Created in collaboration with the Nature Publishing Group, the Structural Biology Knowledgebase monthly update also provides a research library, editorials about new research advances, news, and an events calendar to present a broader view of structural genomics and structural biology

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    Patients\u27 responses to incidentally discovered silent brain infarcts - a qualitative study.

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    BACKGROUND: Incidentally discovered silent brain infarcts (id-SBIs) are an understudied condition with probable clinical significance, but it is not known how patients respond to or prioritize this condition. We sought to assess reporting of id-SBIs and how patients approach their diagnosis. METHODS: Patients with id-SBIs were identified from sequential scans between 12/2015-5/2016, were referred by treating clinicians, or self-referred for the study. This study used qualitative semi-structured interviews. Purposeful sampling was used to achieve diversity in acuity, setting, and recruitment strategy. Interviews were audio-recorded and transcribed. A constant comparative method was used to develop a coding schema, find consensus, and iteratively explore emergent themes until thematic saturation was achieved. RESULTS: Only 10 of 102 patients prospectively identified by neuroimaging were informed of the imaging findings. Twelve participants in total were interviewed. Among the study participants, the primary themes were cognitive, emotional, and behavioral responses to diagnostic, prognostic, and therapeutic uncertainty regarding id-SBIs. Clinicians described id-SBIs to participants as an ambiguous condition. Participants feared potential consequences of id-SBIs, including symptomatic stroke, dementia, and disability. Participants attempted to reduce uncertainty with strategies including equating id-SBIs with symptomatic stroke, self-education about stroke, and seeking second opinions. CONCLUSION: Participants considered id-SBIs to be a serious medical condition. Ambiguous counseling by clinicians on id-SBIs provoked or failed to attenuate fear, leading to participants adopting strategies aimed at reducing uncertainty

    Correction: Clinicians' perspectives on incidentally discovered silent brain infarcts - A qualitative study.

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    [This corrects the article DOI: 10.1371/journal.pone.0194971.]
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