626 research outputs found
Exploring alternative symmetry breaking mechanisms at the LHC with 7, 8 and 10 TeV total energy
In view of the annnouncement that in 2012 the LHC will run at 8 TeV, we study
the possibility of detecting signals of alternative mechanisms of ElectroWeak
Symmetry Breaking, described phenomenologically by unitarized models, at
energies lower than 14 TeV. A complete calculation with six fermions in the
final state is performed using the PHANTOM event generator. Our results
indicate that at 8 TeV some of the scenarios with TeV scale resonances are
likely to be identified while models with no resonances or with very heavy ones
will be inaccessible, unless the available luminosity will be much higher than
expected
Therapeutic limitations in tumor-specific CD8+ memory T cell engraftment
BACKGROUND: Adoptive immunotherapy with cytotoxic T lymphocytes (CTL) represents an alternative approach to treating solid tumors. Ideally, this would confer long-term protection against tumor. We previously demonstrated that in vitro-generated tumor-specific CTL from the ovalbumin (OVA)-specific OT-I T cell receptor transgenic mouse persisted long after adoptive transfer as memory T cells. When recipient mice were challenged with the OVA-expressing E.G7 thymoma, tumor growth was delayed and sometimes prevented. The reasons for therapeutic failures were not clear. METHODS: OT-I CTL were adoptively transferred to C57BL/6 mice 21 – 28 days prior to tumor challenge. At this time, the donor cells had the phenotypical and functional characteristics of memory CD8+ T cells. Recipients which developed tumor despite adoptive immunotherapy were analyzed to evaluate the reason(s) for therapeutic failure. RESULTS: Dose-response studies demonstrated that the degree of tumor protection was directly proportional to the number of OT-I CTL adoptively transferred. At a low dose of OT-I CTL, therapeutic failure was attributed to insufficient numbers of OT-I T cells that persisted in vivo, rather than mechanisms that actively suppressed or anergized the OT-I T cells. In recipients of high numbers of OT-I CTL, the E.G7 tumor that developed was shown to be resistant to fresh OT-I CTL when examined ex vivo. Furthermore, these same tumor cells no longer secreted a detectable level of OVA. In this case, resistance to immunotherapy was secondary to selection of clones of E.G7 that expressed a lower level of tumor antigen. CONCLUSIONS: Memory engraftment with tumor-specific CTL provides long-term protection against tumor. However, there are several limitations to this immunotherapeutic strategy, especially when targeting a single antigen. This study illustrates the importance of administering large numbers of effectors to engraft sufficiently efficacious immunologic memory. It also demonstrates the importance of targeting several antigens when developing vaccine strategies for cancer
New Physics Signals in Longitudinal Gauge Boson Scattering at the LHC
We introduce a novel technique designed to look for signatures of new physics
in vector boson fusion processes at the TeV scale. This functions by measuring
the polarization of the vector bosons to determine the relative longitudinal to
transverse production. In studying this ratio we can directly probe the high
energy E^2-growth of longitudinal vector boson scattering amplitudes
characteristic of models with non-Standard Model (SM) interactions. We will
focus on studying models parameterized by an effective Lagrangian that include
a light Higgs with non-SM couplings arising from TeV scale new physics
associated with the electroweak symmetry breaking, although our technique can
be used in more general scenarios. We will show that this technique is stable
against the large uncertainties that can result from variations in the
factorization scale, improving upon previous studies that measure cross section
alone
RNA secondary structure prediction from multi-aligned sequences
It has been well accepted that the RNA secondary structures of most
functional non-coding RNAs (ncRNAs) are closely related to their functions and
are conserved during evolution. Hence, prediction of conserved secondary
structures from evolutionarily related sequences is one important task in RNA
bioinformatics; the methods are useful not only to further functional analyses
of ncRNAs but also to improve the accuracy of secondary structure predictions
and to find novel functional RNAs from the genome. In this review, I focus on
common secondary structure prediction from a given aligned RNA sequence, in
which one secondary structure whose length is equal to that of the input
alignment is predicted. I systematically review and classify existing tools and
algorithms for the problem, by utilizing the information employed in the tools
and by adopting a unified viewpoint based on maximum expected gain (MEG)
estimators. I believe that this classification will allow a deeper
understanding of each tool and provide users with useful information for
selecting tools for common secondary structure predictions.Comment: A preprint of an invited review manuscript that will be published in
a chapter of the book `Methods in Molecular Biology'. Note that this version
of the manuscript may differ from the published versio
Near-infrared reflectance imaging of neovascular age-related macular degeneration
Contains fulltext :
81007.pdf (publisher's version ) (Closed access)PURPOSE: To evaluate various types of neovascular age-related macular degeneration (AMD) by near-infrared fundus reflectance (NIR) as compared to fundus fluorescein angiography (FFA) and to test NIR for assessment of leakage due to choroidal neovascularization (CNV). PATIENTS AND METHODS: Thirty-three patients with neovascular AMD (cases) and 20 age-matched patients with non-exudative AMD and healthy subjects (controls) were examined with a confocal scanning laser ophthalmoscope (Heidelberg Retina Angiograph 2). NIR images of neovascular AMD were qualitatively compared to the corresponding FFA and to age-matched controls. CNV membranes and exudation areas were manually segmented on FFA and NIR and analyzed quantitatively. Results : Of all cases included, five eyes had classic CNV, six had minimal classic lesions, 15 occult CNV's and seven eyes had retinal angiomatous proliferation (RAP). A dark halo on NIR was found in all cases and showed high correspondence to leakage on FFA (r (2) = 0.93; p < 0,0005). In classic CNV and minimal classic CNV, the classic part of the lesion on FFA revealed strong correlation to a dark core surrounded by a bright reflecting ring on NIR (r (2) = 0.88; p < 0.0005). Occult parts on FFA of minimal classic CNV and occult CNV lesions appeared as poorly demarcated, jagged areas of increased NIR. RAP was characterized by speckled NIR located at the intraretinal neovascular complex. CONCLUSIONS: NIR imaging in neovascular AMD revealed characteristic alterations depending on the type of CNV. These changes may reflect histological differences of the lesions. Leakage caused local darkening of NIR, presumably originating from increased light-scattering and absorbance by fluid accumulation and sub-cellular structure alterations
Cellular Radiosensitivity: How much better do we understand it?
Purpose: Ionizing radiation exposure gives rise to a variety of lesions in DNA that result in genetic instability and potentially tumorigenesis or cell death. Radiation extends its effects on DNA by direct interaction or by radiolysis of H2O that generates free radicals or aqueous electrons capable of interacting with and causing indirect damage to DNA. While the various lesions arising in DNA after radiation exposure can contribute to the mutagenising effects of this agent, the potentially most damaging lesion is the DNA double strand break (DSB) that contributes to genome instability and/or cell death. Thus in many cases failure to recognise and/or repair this lesion determines the radiosensitivity status of the cell. DNA repair mechanisms including homologous recombination (HR) and non-homologous end-joining (NHEJ) have evolved to protect cells against DNA DSB. Mutations in proteins that constitute these repair pathways are characterised by radiosensitivity and genome instability. Defects in a number of these proteins also give rise to genetic disorders that feature not only genetic instability but also immunodeficiency, cancer predisposition, neurodegeneration and other pathologies.
Conclusions: In the past fifty years our understanding of the cellular response to radiation damage has advanced enormously with insight being gained from a wide range of approaches extending from more basic early studies to the sophisticated approaches used today. In this review we discuss our current understanding of the impact of radiation on the cell and the organism gained from the array of past and present studies and attempt to provide an explanation for what it is that determines the response to radiation
Comparison of printed glycan array, suspension array and ELISA in the detection of human anti-glycan antibodies
Anti-glycan antibodies represent a vast and yet insufficiently investigated subpopulation of naturally occurring and adaptive antibodies in humans. Recently, a variety of glycan-based microarrays emerged, allowing high-throughput profiling of a large repertoire of antibodies. As there are no direct approaches for comparison and evaluation of multi-glycan assays we compared three glycan-based immunoassays, namely printed glycan array (PGA), fluorescent microsphere-based suspension array (SA) and ELISA for their efficacy and selectivity in profiling anti-glycan antibodies in a cohort of 48 patients with and without ovarian cancer. The ABO blood group glycan antigens were selected as well recognized ligands for sensitivity and specificity assessments. As another ligand we selected P1, a member of the P blood group system recently identified by PGA as a potential ovarian cancer biomarker. All three glyco-immunoassays reflected the known ABO blood groups with high performance. In contrast, anti-P1 antibody binding profiles displayed much lower concordance. Whilst anti-P1 antibody levels between benign controls and ovarian cancer patients were significantly discriminated using PGA (p = 0.004), we got only similar results using SA (p = 0.03) but not for ELISA. Our findings demonstrate that whilst assays were largely positively correlated, each presents unique characteristic features and should be validated by an independent patient cohort rather than another array technique. The variety between methods presumably reflects the differences in glycan presentation and the antigen/antibody ratio, assay conditions and detection technique. This indicates that the glycan-antibody interaction of interest has to guide the assay selection
Serratia marcescens Is Able to Survive and Proliferate in Autophagic-Like Vacuoles inside Non-Phagocytic Cells
Serratia marcescens is an opportunistic human pathogen that represents a growing problem for public health, particularly in hospitalized or immunocompromised patients. However, little is known about factors and mechanisms that contribute to S. marcescens pathogenesis within its host. In this work, we explore the invasion process of this opportunistic pathogen to epithelial cells. We demonstrate that once internalized, Serratia is able not only to persist but also to multiply inside a large membrane-bound compartment. This structure displays autophagic-like features, acquiring LC3 and Rab7, markers described to be recruited throughout the progression of antibacterial autophagy. The majority of the autophagic-like vacuoles in which Serratia resides and proliferates are non-acidic and have no degradative properties, indicating that the bacteria are capable to either delay or prevent fusion with lysosomal compartments, altering the expected progression of autophagosome maturation. In addition, our results demonstrate that Serratia triggers a non-canonical autophagic process before internalization. These findings reveal that S. marcescens is able to manipulate the autophagic traffic, generating a suitable niche for survival and proliferation inside the host cell
Chrysolina herbacea Modulates Terpenoid Biosynthesis of Mentha aquatica L.
Interactions between herbivorous insects and plants storing terpenoids are poorly
understood. This study describes the ability of Chrysolina
herbacea to use volatiles emitted by undamaged Mentha
aquatica plants as attractants and the plant's response to
herbivory, which involves the production of deterrent molecules. Emitted plant
volatiles were analyzed by GC-MS. The insect's response to plant volatiles
was tested by Y-tube olfactometer bioassays. Total RNA was extracted from
control plants, mechanically damaged leaves, and leaves damaged by herbivores.
The terpenoid quantitative gene expressions (qPCR) were then assayed. Upon
herbivory, M. aquatica synthesizes and emits
(+)-menthofuran, which acts as a deterrent to C. herbacea.
Herbivory was found to up-regulate the expression of genes involved in terpenoid
biosynthesis. The increased emission of (+)-menthofuran was correlated with
the upregulation of (+)-menthofuran synthase
Unemployment and ill health: a connection through inflammation?
<p>Abstract</p> <p>Background</p> <p>Unemployment is a source of acute and long-term psychosocial stress. Acute and chronic psychosocial stress can induce pronounced changes in human immune responses. In this study we tested our hypothesis that stress-induced low-grade tissue inflammation is more prevalent among the unemployed.</p> <p>Methods</p> <p>We determined the inflammatory status of 225 general population subjects below the general retirement age (65 years in Finland). Those who had levels of both interleukin-6 (≥ 0.97 pg/mL) and high-sensitivity C-reactive protein (≥ 1.49 mg/L) above the median were assessed to have an elevated inflammatory status (n = 72).</p> <p>Results</p> <p>An elevated inflammatory status was more common among the unemployed than among other study participants (59% versus 30%, p = 0.011). In the final multivariate model, those who were unemployed had over five-fold greater odds for having an elevated inflammatory status (OR 5.20, 95% CI 1.55-17.43, p = 0.008).</p> <p>Conclusion</p> <p>This preliminary finding suggests that stress-induced low-grade inflammation might be a link between unemployment and ill health.</p
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