187 research outputs found
DC-SIGN (CD209) mediates dengue virus infection of human dendritic cells
Dengue virus is a single-stranded, enveloped RNA virus that productively infects human dendritic cells (DCs) primarily at the immature stage of their differentiation. We now find that all four serotypes of dengue use DC-SIGN (CD209), a C-type lectin, to infect dendritic cells. THP-1 cells become susceptible to dengue infection after transfection of DC-specific ICAM-3 grabbing nonintegrin (DC-SIGN), or its homologue L-SIGN, whereas the infection of dendritic cells is blocked by anti-DC-SIGN antibodies and not by antibodies to other molecules on these cells. Viruses produced by dendritic cells are infectious for DC-SIGN- and L-SIGN-bearing THP-1 cells and other permissive cell lines. Therefore, DC-SIGN may be considered as a new target for designing therapies that block dengue infection
Zn3As2 Nanowires and nanoplatelets: highly efficient infrared emission and photodetection by an earth abundant material
The development of earth abundant materials for optoelectronics and photovoltaics promises improvements in sustainability and scalability. Recent studies have further demonstrated enhanced material efficiency through the superior light management of novel nanoscale geometries such as the nanowire. Here we show that an industry standard epitaxy technique can be used to fabricate high quality II-V nanowires (1D) and nanoplatelets (2D) of the earth abundant semiconductor Zn3As2. We go on to establish the optoelectronic potential of this material by demonstrating efficient photoemission and detection at 1.0 eV, an energy which is significant to the fields of both photovoltaics and optical telecommunications. Through dynamical spectroscopy this superior performance is found to arise from a low rate of surface recombination combined with a high rate of radiative recombination. These results introduce nanostructured Zn3As2 as a high quality optoelectronic material ready for device exploration.T.B., P.C., Y.G., H.H.T., and C.J. acknowledge the Australian
Research Council. T.B., P.C., Y.G., H.H.T., and C.J. thank the
Australian National Fabrication Facility for access to the growth
and microscopy facilities and Centre for Advanced Microscopy
and Australian Microscopy and Microanalysis Research Facility
for access to microscopy facilities used in this work. Y.W., B.B.,
H.E.J., and L.M.S. acknowledge the financial support of the
National Science Foundation through grants DMR-1105362,
1105121, and ECCS-1100489
DC-SIGN (CD209) Mediates Dengue Virus Infection of Human Dendritic Cells
Dengue virus is a single-stranded, enveloped RNA virus that productively infects human dendritic cells (DCs) primarily at the immature stage of their differentiation. We now find that all four serotypes of dengue use DC-SIGN (CD209), a C-type lectin, to infect dendritic cells. THP-1 cells become susceptible to dengue infection after transfection of DC-specific ICAM-3 grabbing nonintegrin (DC-SIGN), or its homologue L-SIGN, whereas the infection of dendritic cells is blocked by anti–DC-SIGN antibodies and not by antibodies to other molecules on these cells. Viruses produced by dendritic cells are infectious for DC-SIGN– and L-SIGN–bearing THP-1 cells and other permissive cell lines. Therefore, DC-SIGN may be considered as a new target for designing therapies that block dengue infection
Fenebrutinib in H1 antihistamine-refractory chronic spontaneous urticaria: a randomized phase 2 trial
Bruton’s tyrosine kinase (BTK) is crucial for FcεRI-mediated mast cell activation and essential for autoantibody production by B cells in chronic spontaneous urticaria (CSU). Fenebrutinib, an orally administered, potent, highly selective, reversible BTK inhibitor, may be effective in CSU. This double-blind, placebo-controlled, phase 2 trial (EudraCT ID 2016-004624-35) randomized 93 adults with antihistamine-refractory CSU to 50 mg daily, 150 mg daily and 200 mg twice daily of fenebrutinib or placebo for 8 weeks. The primary end point was change from baseline in urticaria activity score over 7 d (UAS7) at week 8. Secondary end points were the change from baseline in UAS7 at week 4 and the proportion of patients well-controlled (UAS7 ≤ 6) at week 8. Fenebrutinib efficacy in patients with type IIb autoimmunity and effects on IgG-anti-FcεRI were exploratory end points. Safety was also evaluated. The primary end point was met, with dose-dependent improvements in UAS7 at week 8 occurring at 200 mg twice daily and 150 mg daily, but not at 50 mg daily of fenebrutinib versus placebo. Asymptomatic, reversible grade 2 and 3 liver transaminase elevations occurred in the fenebrutinib 150 mg daily and 200 mg twice daily groups (2 patients each). Fenebrutinib diminished disease activity in patients with antihistamine-refractory CSU, including more patients with refractory type IIb autoimmunity. These results support the potential use of BTK inhibition in antihistamine-refractory CSU
Toward a Surrogate Marker of Malaria Exposure: Modeling Longitudinal Antibody Measurements under Outbreak Conditions
Background: Biomarkers of exposure to Plasmodium falciparum would be a useful tool for the assessment of malaria burden and analysis of intervention and epidemiological studies. Antibodies to pre-erythrocytic antigens represent potential surrogates of exposure. Methods and Findings: In an outbreak cohort of U.S. Marines deployed to Liberia, we modeled pre- and post-deployment IgG against P. falciparum sporozoites by immunofluorescence antibody test, and both IgG and IgM against the P. falciparum circumsporozoite protein by enzyme-linked immunosorbant assay. Modeling seroconversion thresholds by a fixed ratio, linear regression or nonlinear regression produced sensitivity for identification of exposed U.S. Marines between 58-70% and specificities between 87-97%, compared with malaria-naïve U.S. volunteers. Exposure was predicted in 30-45% of the cohort. Conclusion: Each of the three models tested has merits in different studies, but further development and validation in endemic populations is required. Overall, these models provide support for an antibody-based surrogate marker of exposure to malaria
Instances and connectors : issues for a second generation process language
This work is supported by UK EPSRC grants GR/L34433 and GR/L32699Over the past decade a variety of process languages have been defined, used and evaluated. It is now possible to consider second generation languages based on this experience. Rather than develop a second generation wish list this position paper explores two issues: instances and connectors. Instances relate to the relationship between a process model as a description and the, possibly multiple, enacting instances which are created from it. Connectors refers to the issue of concurrency control and achieving a higher level of abstraction in how parts of a model interact. We believe that these issues are key to developing systems which can effectively support business processes, and that they have not received sufficient attention within the process modelling community. Through exploring these issues we also illustrate our approach to designing a second generation process language.Postprin
Mutation of pescadillo Disrupts Oligodendrocyte Formation in Zebrafish
Background: In vertebrates, the myelin sheath is essential for efficient propagation of action potentials along the axon shaft. Oligodendrocytes are the cells of the central nervous system that create myelin sheaths. During embryogenesis, ventral neural tube precursors give rise to oligodendrocyte progenitor cells, which divide and migrate throughout the central nervous system. This study aimed to investigate mechanisms that regulate oligodendrocyte progenitor cell formation. Methodology/Principal Findings: By conducting a mutagenesis screen in transgenic zebrafish, we identified a mutation, designated vu166, by an apparent reduction in the number of oligodendrocyte progenitor cells in the dorsal spinal cord. We subsequently determined that vu166 is an allele of pescadillo, a gene known to play a role in ribosome biogenesis and cell proliferation. We found that pescadillo function is required for both the proper number of oligodendrocyte progenitors to form, by regulating cell cycle progression, and for normal levels of myelin gene expression. Conclusions/Significance: Our data provide evidence that neural precursors require pes function to progress through th
Influenza virus infection among pediatric patients reporting diarrhea and influenza-like illness
<p>Abstract</p> <p>Background</p> <p>Influenza is a major cause of morbidity and hospitalization among children. While less often reported in adults, gastrointestinal symptoms have been associated with influenza in children, including abdominal pain, nausea, vomiting, and diarrhea.</p> <p>Methods</p> <p>From September 2005 and April 2008, pediatric patients in Indonesia presenting with concurrent diarrhea and influenza-like illness were enrolled in a study to determine the frequency of influenza virus infection in young patients presenting with symptoms less commonly associated with an upper respiratory tract infection (URTI). Stool specimens and upper respiratory swabs were assayed for the presence of influenza virus.</p> <p>Results</p> <p>Seasonal influenza A or influenza B viral RNA was detected in 85 (11.6%) upper respiratory specimens and 21 (2.9%) of stool specimens. Viable influenza B virus was isolated from the stool specimen of one case. During the time of this study, human infections with highly pathogenic avian influenza A (H5N1) virus were common in the survey area. However, among 733 enrolled subjects, none had evidence of H5N1 virus infection.</p> <p>Conclusions</p> <p>The detection of influenza viral RNA and viable influenza virus from stool suggests that influenza virus may be localized in the gastrointestinal tract of children, may be associated with pediatric diarrhea and may serve as a potential mode of transmission during seasonal and epidemic influenza outbreaks.</p
COX-2-Derived Prostaglandin E2 Produced by Pyramidal Neurons Contributes to Neurovascular Coupling in the Rodent Cerebral Cortex
International audienceVasodilatory prostaglandins play a key role in neurovascular coupling (NVC), the tight link between neuronal activity and local cerebral blood flow, but their precise identity, cellular origin and the receptors involved remain unclear. Here we show in rats that NMDA-induced vasodilation and hemodynamic responses evoked by whisker stimulation involve cyclooxygenase-2 (COX-2) activity and activation of the prostaglandin E2 (PgE(2)) receptors EP2 and EP4. Using liquid chromatography-electrospray ionization-tandem mass spectrometry, we demonstrate that PgE(2) is released by NMDA in cortical slices. The characterization of PgE2 producing cells by immunohistochemistry and single-cell reverse transcriptase-PCR revealed that pyramidal cells and not astrocytes are the main cell type equipped for PgE2 synthesis, one third expressing COX-2 systematically associated with a PgE2 synthase. Consistent with their central role in NVC, in vivo optogenetic stimulation of pyramidal cells evoked COX-2-dependent hyperemic responses in mice. These observations identify PgE2 as the main prostaglandin mediating sensory-evoked NVC, pyramidal cells as their principal source and vasodilatory EP2 and EP4 receptors as their targets
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