378 research outputs found

    A day in the life of marine sulfonates

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    Lab-based studies, combined with metatranscriptomic and metabolomic field analyses, reveal important diel-linked roles for sulfonates in the major classes of phytoplankton that produce them, and in the environment in which they feed ubiquitous heterotrophic bacteri

    YihQ is a sulfoquinovosidase that cleaves sulfoquinovosyl diacylglyceride sulfolipids

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    Sulfoquinovose is produced by photosynthetic organisms at a rate of 1010 tons per annum and is degraded by bacteria as a source of carbon and sulfur. We have identified Escherichia coli YihQ as the first dedicated sulfoquinovosidase and the gateway enzyme to sulfoglycolytic pathways. Structural and mutagenesis studies unveiled the sequence signatures for binding the distinguishing sulfonate residue and revealed that sulfoquinovoside degradation is widespread across the tree of life

    Participant Experiences with a New Online Modified-Delphi Approach for Engaging Patients and Caregivers in Developing Clinical Guidelines

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    Background Patient engagement in clinical practice guideline (CPG) development has increased significantly in recent years. However, only a few patients and caregivers join CPG development groups. Objective To describe participant experiences with a novel online, scalable approach for patient and caregiver engagement in CPG development. Design We developed and tested the RAND/PPMD Patient-Centeredness Method (RPM), a novel online modified-Delphi approach to patient engagement in CPG development that consists of an optional idea generation round and two rating rounds interspersed with an online discussion round. Setting and Participants Using the online ExpertLens™ system, we ran 2 concurrent panels of patients and caregivers of individuals with Duchenne Muscular Dystrophy (DMD). Main Outcome Measures We surveyed all 95 panel participants about their participation and satisfaction with the process. We also conducted telephone interviews with 25 participants. Results Participants expressed satisfaction with various ExpertLens™ features, noting that the system fostered lively interaction among them. Panelists also appreciated participating in an educational, interactive and convenient discussion forum that allowed them to share their opinions on the importance and acceptability of different recommendations. The RPM was viewed as empowering by patients and their caregivers who felt it would be useful for CPG developers. Discussion and Conclusion The results of our study show the overall participant satisfaction with a novel, scalable, online approach to engaging patients and caregivers in CPG development, which allows them to share their perspectives and lived experiences using a rigorous, systematic and iterative way that is similar to how clinicians provide their input

    The RAND/PPMD Patient-Centeredness Method: a novel online approach to engaging patients and their representatives in guideline development

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    Although clinical practice guidelines (CPGs) provide recommendations for how best to treat a typical patient with a given condition, patients and their representatives are not always engaged in CPG development. Despite the agreement that patient participation may improve the quality and utility of CPGs, there is no systematic, scalable method for engaging patients and their representatives, as well as no consensus on what exactly patients and their representatives should be asked to do during CPG development. To address these gaps, an interdisciplinary team of researchers, patient representatives, and clinicians developed the RAND/PPMD Patient-Centeredness Method (RPM) - a novel online approach to engaging patients and their representatives in CPG development. The RPM is an iterative approach that allows patients and their representatives to provide input by (1) generating ideas; (2) rating draft recommendations on two criteria (importance and acceptability); (3) explaining and discussing their ratings with other participants using online, asynchronous, anonymous, moderated discussion boards, and (4) revising their responses if needed. The RPM was designed to be consistent with the RAND/UCLA Appropriateness Method used by clinicians and researchers to develop CPG, while helping patients and their representative rate outcome importance and recommendation acceptability - two key components of the GRADE Evidence to Decision (EtD) framework. With slight modifications, the RPM has the potential to explore consensus among key stakeholders on other dimensions of the EtD, including feasibility, equity, and resource use

    Unspecific CTL Killing Is Enhanced by High Glucose via TNF-Related Apoptosis-Inducing Ligand

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    TNF-related apoptosis inducing ligand (TRAIL) is expressed on cytotoxic T lymphocytes (CTLs) and TRAIL is linked to progression of diabetes. However, the impact of high glucose on TRAIL expression and its related killing function in CTLs still remains largely elusive. Here, we report that TRAIL is substantially up-regulated in CTLs in environments with high glucose (HG) both in vitro and in vivo. Non-mitochondrial reactive oxygen species, NFκB and PI3K/Akt are essential in HG-induced TRAIL upregulation in CTLs. TRAILhigh CTLs induce apoptosis of pancreatic beta cell line 1.4E7. Treatment with metformin and vitamin D reduces HG-enhanced expression of TRAIL in CTLs and coherently protects 1.4E7 cells from TRAIL-mediated apoptosis. Our work suggests that HG-induced TRAILhigh CTLs might contribute to the destruction of pancreatic beta cells in a hyperglycemia condition

    Detecting a stochastic gravitational wave background with the Laser Interferometer Space Antenna

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    The random superposition of many weak sources will produce a stochastic background of gravitational waves that may dominate the response of the LISA (Laser Interferometer Space Antenna) gravitational wave observatory. Unless something can be done to distinguish between a stochastic background and detector noise, the two will combine to form an effective noise floor for the detector. Two methods have been proposed to solve this problem. The first is to cross-correlate the output of two independent interferometers. The second is an ingenious scheme for monitoring the instrument noise by operating LISA as a Sagnac interferometer. Here we derive the optimal orbital alignment for cross-correlating a pair of LISA detectors, and provide the first analytic derivation of the Sagnac sensitivity curve.Comment: 9 pages, 11 figures. Significant changes to the noise estimate

    Anaerobic Degradation of the Plant Sugar Sulfoquinovose Concomitant With H2S Production: Escherichia coli K-12 and Desulfovibrio sp. Strain DF1 as Co-culture Model

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    Sulfoquinovose (SQ, 6-deoxy-6-sulfoglucose) is produced by plants and other phototrophs and its biodegradation is a relevant component of the biogeochemical carbon and sulfur cycles. SQ is known to be degraded by aerobic bacterial consortia in two tiers via C3-organosulfonates as transient intermediates to CO2, water and sulfate. In this study, we present a first laboratory model for anaerobic degradation of SQ by bacterial consortia in two tiers to acetate and hydrogen sulfide (H2S). For the first tier, SQ-degrading Escherichia coli K-12 was used. It catalyzes the fermentation of SQ to 2,3-dihydroxypropane-1-sulfonate (DHPS), succinate, acetate and formate, thus, a novel type of mixed-acid fermentation. It employs the characterized SQ Embden-Meyerhof-Parnas pathway, as confirmed by mutational and proteomic analyses. For the second tier, a DHPS-degrading Desulfovibrio sp. isolate from anaerobic sewage sludge was used, strain DF1. It catalyzes another novel fermentation, of the DHPS to acetate and H2S. Its DHPS desulfonation pathway was identified by differential proteomics and demonstrated by heterologously produced enzymes: DHPS is oxidized via 3-sulfolactaldehyde to 3-sulfolactate (SL) by two NAD+-dependent dehydrogenases (DhpA, SlaB); the SL is cleaved by an SL sulfite-lyase known from aerobic bacteria (SuyAB) to pyruvate and sulfite. The pyruvate is oxidized to acetate, while the sulfite is used as electron acceptor in respiration and reduced to H2S. In conclusion, anaerobic sulfidogenic SQ degradation was demonstrated as a novel link in the biogeochemical sulfur cycle. SQ is also a constituent of the green-vegetable diet of herbivores and omnivores and H2S production in the intestinal microbiome has many recognized and potential contributions to human health and disease. Hence, it is important to examine bacterial SQ degradation also in the human intestinal microbiome, in relation to H2S production, dietary conditions and human health

    Meeting Report: Methylmercury in Marine Ecosystems—From Sources to Seafood Consumers

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    Mercury and other contaminants in coastal and open-ocean ecosystems are an issue of great concern globally and in the United States, where consumption of marine fish and shellfish is a major route of human exposure to methylmercury (MeHg). A recent National Institute of Environmental Health Sciences–Superfund Basic Research Program workshop titled “Fate and Bioavailability of Mercury in Aquatic Ecosystems and Effects on Human Exposure,” convened by the Dartmouth Toxic Metals Research Program on 15–16 November 2006 in Durham, New Hampshire, brought together human health experts, marine scientists, and ecotoxicologists to encourage cross-disciplinary discussion between ecosystem and human health scientists and to articulate research and monitoring priorities to better understand how marine food webs have become contaminated with MeHg. Although human health effects of Hg contamination were a major theme, the workshop also explored effects on marine biota. The workgroup focused on three major topics: a) the biogeochemical cycling of Hg in marine ecosystems, b) the trophic transfer and bioaccumulation of MeHg in marine food webs, and c) human exposure to Hg from marine fish and shellfish consumption. The group concluded that current understanding of Hg in marine ecosystems across a range of habitats, chemical conditions, and ocean basins is severely data limited. An integrated research and monitoring program is needed to link the processes and mechanisms of MeHg production, bioaccumulation, and transfer with MeHg exposure in humans
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