1,252 research outputs found
Mesoniviruses are mosquito-specific viruses with extensive geographic distribution and host range
Background: The family Mesoniviridae (order Nidovirales) comprises of a group of positive-sense, single-stranded RNA ([+]ssRNA) viruses isolated from mosquitoes. Findings. Thirteen novel insect-specific virus isolates were obtained from mosquitoes collected in Indonesia, Thailand and the USA. By electron microscopy, the virions appeared as spherical particles with a diameter of ∼50 nm. Their 20,129 nt to 20,777 nt genomes consist of positive-sense, single-stranded RNA with a poly-A tail. Four isolates from Houston, Texas, and one isolate from Java, Indonesia, were identified as variants of the species Alphamesonivirus-1 which also includes Nam Dinh virus (NDiV) from Vietnam and Cavally virus (CavV) from Côte d'Ivoire. The eight other isolates were identified as variants of three new mesoniviruses, based on genome organization and pairwise evolutionary distances: Karang Sari virus (KSaV) from Java, Bontag Baru virus (BBaV) from Java and Kalimantan, and Kamphaeng Phet virus (KPhV) from Thailand. In comparison with NDiV, the three new mesoniviruses each contained a long insertion (180 - 588 nt) of unknown function in the 5' region of ORF1a, which accounted for much of the difference in genome size. The insertions contained various short imperfect repeats and may have arisen by recombination or sequence duplication. Conclusions: In summary, based on their genome organizations and phylogenetic relationships, thirteen new viruses were identified as members of the family Mesoniviridae, order Nidovirales. Species demarcation criteria employed previously for mesoniviruses would place five of these isolates in the same species as NDiV and CavV (Alphamesonivirus-1) and the other eight isolates would represent three new mesonivirus species (Alphamesonivirus-5, Alphamesonivirus-6 and Alphamesonivirus-7). The observed spatiotemporal distribution over widespread geographic regions and broad species host range in mosquitoes suggests that mesoniviruses may be common in mosquito populations worldwide. © 2014 Vasilakis et al.; licensee BioMed Central Ltd
Rituximab in B-Cell Hematologic Malignancies: A Review of 20 Years of Clinical Experience
Rituximab is a human/murine, chimeric anti-CD20 monoclonal antibody with established efficacy, and a favorable and well-defined safety profile in patients with various CD20-expressing lymphoid malignancies, including indolent and aggressive forms of B-cell non-Hodgkin lymphoma. Since its first approval 20 years ago, intravenously administered rituximab has revolutionized the treatment of B-cell malignancies and has become a standard component of care for follicular lymphoma, diffuse large B-cell lymphoma, chronic lymphocytic leukemia, and mantle cell lymphoma. For all of these diseases, clinical trials have demonstrated that rituximab not only prolongs the time to disease progression but also extends overall survival. Efficacy benefits have also been shown in patients with marginal zone lymphoma and in more aggressive diseases such as Burkitt lymphoma. Although the proven clinical efficacy and success of rituximab has led to the development of other anti-CD20 monoclonal antibodies in recent years (e.g., obinutuzumab, ofatumumab, veltuzumab, and ocrelizumab), rituximab is likely to maintain a position within the therapeutic armamentarium because it is well established with a long history of successful clinical use. Furthermore, a subcutaneous formulation of the drug has been approved both in the EU and in the USA for the treatment of B-cell malignancies. Using the wealth of data published on rituximab during the last two decades, we review the preclinical development of rituximab and the clinical experience gained in the treatment of hematologic B-cell malignancies, with a focus on the well-established intravenous route of administration. This article is a companion paper to A. Davies, et al., which is also published in this issue
The development of direct extrusion-injection moulded zein matrices as novel oral controlled drug delivery systems
Purpose: To evaluate the potential of zein as a sole excipient for controlled release formulations prepared by hot melt extrusion. Methods: Physical mixtures of zein, water and crystalline paracetamol were hot melt extruded (HME) at 80°C and injection moulded (IM) into caplet forms. HME-IM Caplets were characterised using differential scanning calorimetry, ATR-FTIR spectroscopy, scanning electron microscopy and powder X-ray diffraction. Hydration and drug release kinetics of the caplets were investigated and fitted to a diffusion model. Results: For the formulations with lower drug loadings, the drug was found to be in the non-crystalline state, while for the ones with higher drug loadings paracetamol is mostly crystalline. Release was found to be largely independent of drug loading but strongly dependent upon device dimensions, and predominately governed by a Fickian diffusion mechanism, while the hydration kinetics shows the features of Case II diffusion. Conclusions: In this study a prototype controlled release caplet formulation using zein as the sole excipient was successfully prepared using direct HME-IM processing. The results demonstrated the unique advantage of the hot melt extruded zein formulations on the tuneability of drug release rate by alternating the device dimensions
In Vitro Downregulation of Matrix Metalloproteinase-9 in Rat Glial Cells by CCR5 Antagonist Maraviroc: Therapeutic Implication for HIV Brain Infection
BACKGROUND: Matrix metalloproteinases (MMPs) released by glial cells are important mediators of neuroinflammation and neurologic damage in HIV infection. The use of antiretroviral drugs able to combat the detrimental effect of chronic inflammation and target the exaggerated MMP activity might represent an attractive therapeutic challenge. Recent studies suggest that CCR5 antagonist maraviroc (MVC) exerts immunomodulant and anti-inflammatory activity beyond its anti-HIV properties. We investigated the in vitro effect of MVC on the activity of MMPs in astrocyte and microglia cultures.
METHODOLOGY/PRINCIPAL FINDINGS: Primary cultures of rat astrocytes and microglia were activated by exposure to phorbol myristate acetate (PMA) or lypopolysaccharide (LPS) and treated in vitro with MVC. Culture supernatants were subjected to gelatin zymography and quantitative determination of MMP-9 and MMP-2 was done by computerized scanning densitometry. MMP-9 levels were significantly elevated in culture supernatants from both LPS- and PMA-activated astrocytes and microglia in comparison to controls. The treatment with MVC significantly inhibited in a dose-dependent manner the levels and expression of MMP-9 in PMA-activated astrocytes (p<0,05) and, to a lesser extent, in PMA-activated microglia. By contrast, levels of MMP-2 did not significantly change, although a tendency to decrease was seen in PMA-activated astrocytes after treatment with MVC. The inhibition of levels and expression of MMP-9 in PMA-activated glial cells did not depend on cytotoxic effects of MVC. No inhibition of MMP-9 and MMP-2 were found in both LPS-activated astrocytes and microglia.
CONCLUSIONS: The present in vitro study suggests that CCR5 antagonist compounds, through their ability to inhibit MMP-9 expression and levels, might have a great potential for the treatment of HIV-associated neurologic damage
TRY plant trait database - enhanced coverage and open access
Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
Observation and study of baryonic B decays: B -> D(*) p pbar, D(*) p pbar pi, and D(*) p pbar pi pi
We present a study of ten B-meson decays to a D(*), a proton-antiproton pair,
and a system of up to two pions using BaBar's data set of 455x10^6 BBbar pairs.
Four of the modes (B0bar -> D0 p anti-p, B0bar -> D*0 p anti-p, B0bar -> D+ p
anti-p pi-, B0bar -> D*+ p anti-p pi-) are studied with improved statistics
compared to previous measurements; six of the modes (B- -> D0 p anti-p pi-, B-
-> D*0 p anti-p pi-, B0bar -> D0 p anti-p pi- pi+, B0bar -> D*0 p anti-p pi-
pi+, B- -> D+ p anti-p pi- pi-, B- -> D*+ p anti-p pi- pi-) are first
observations. The branching fractions for 3- and 5-body decays are suppressed
compared to 4-body decays. Kinematic distributions for 3-body decays show
non-overlapping threshold enhancements in m(p anti-p) and m(D(*)0 p) in the
Dalitz plots. For 4-body decays, m(p pi-) mass projections show a narrow peak
with mass and full width of (1497.4 +- 3.0 +- 0.9) MeV/c2, and (47 +- 12 +- 4)
MeV/c2, respectively, where the first (second) errors are statistical
(systematic). For 5-body decays, mass projections are similar to phase space
expectations. All results are preliminary.Comment: 28 pages, 90 postscript figures, submitted to LP0
Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at √s = 7 TeV with the ATLAS detector
This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of √s = 7 TeV;{\rm Te}{\rm V}4.6\;{\rm f}{{{\rm b}}^{-1}}{{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}|\eta |\lt 1.9{{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques
Search for the neutral Higgs bosons of the minimal supersymmetric standard model in pp collisions at root s=7 TeV with the ATLAS detector
A search for neutral Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) is reported. The analysis is based on a sample of proton-proton collisions at a centre-of-mass energy of 7TeV recorded with the ATLAS detector at the Large Hadron Collider. The data were recorded in 2011 and correspond to an integrated luminosity of 4.7 fb-1 to 4.8 fb-1. Higgs boson decays into oppositely-charged muon or τ lepton pairs are considered for final states requiring either the presence or absence of b-jets. No statistically significant excess over the expected background is observed and exclusion limits at the 95% confidence level are derived. The exclusion limits are for the production cross-section of a generic neutral Higgs boson, φ, as a function of the Higgs boson mass and for h/A/H production in the MSSM as a function of the parameters mA and tan β in the mhmax scenario for mA in the range of 90GeV to 500 GeV. Copyright CERN
- …