2,457 research outputs found
Gene expression profiling identifies distinct molecular subgroups of leiomyosarcoma with clinical relevance
YesBackground: Soft tissue sarcomas are heterogeneous and a major complication in their management is that the existing
classification scheme is not definitive and is still evolving. Leiomyosarcomas, a major histologic category of soft tissue sarcomas,
are malignant tumours displaying smooth muscle differentiation. Although defined as a single group, they exhibit a wide range of
clinical behaviour. We aimed to carry out molecular classification to identify new molecular subgroups with clinical relevance.
Methods: We used gene expression profiling on 20 extra-uterine leiomyosarcomas and cross-study analyses for molecular
classification of leiomyosarcomas. Clinical significance of the subgroupings was investigated.
Results: We have identified two distinct molecular subgroups of leiomyosarcomas. One group was characterised by high
expression of 26 genes that included many genes from the sub-classification gene cluster proposed by Nielsen et al. These
sub-classification genes include genes that have importance structurally, as well as in cell signalling. Notably, we found a
statistically significant association of the subgroupings with tumour grade. Further refinement led to a group of 15 genes that
could recapitulate the tumour subgroupings in our data set and in a second independent sarcoma set. Remarkably, cross-study
analyses suggested that these molecular subgroups could be found in four independent data sets, providing strong support for
their existence.
Conclusions: Our study strongly supported the existence of distinct leiomyosarcoma molecular subgroups, which have clinical
association with tumour grade. Our findings will aid in advancing the classification of leiomyosarcomas and lead to more
individualised and better management of the disease.Alexander Boag Sarcoma Fund
Dark Matter from Minimal Flavor Violation
We consider theories of flavored dark matter, in which the dark matter
particle is part of a multiplet transforming nontrivially under the flavor
group of the Standard Model in a manner consistent with the principle of
Minimal Flavor Violation (MFV). MFV automatically leads to the stability of the
lightest state for a large number of flavor multiplets. If neutral, this
particle is an excellent dark matter candidate. Furthermore, MFV implies
specific patterns of mass splittings among the flavors of dark matter and
governs the structure of the couplings between dark matter and ordinary
particles, leading to a rich and predictive cosmology and phenomenology. We
present an illustrative phenomenological study of an effective theory of a
flavor SU(3)_Q triplet, gauge singlet scalar.Comment: 10 pages, 2 figures; v2: references added, minor changes to collider
analysis, conclusions unchange
Search for time-dependent B0s - B0s-bar oscillations using a vertex charge dipole technique
We report a search for B0s - B0s-bar oscillations using a sample of 400,000
hadronic Z0 decays collected by the SLD experiment. The analysis takes
advantage of the electron beam polarization as well as information from the
hemisphere opposite that of the reconstructed B decay to tag the B production
flavor. The excellent resolution provided by the pixel CCD vertex detector is
exploited to cleanly reconstruct both B and cascade D decay vertices, and tag
the B decay flavor from the charge difference between them. We exclude the
following values of the B0s - B0s-bar oscillation frequency: Delta m_s < 4.9
ps-1 and 7.9 < Delta m_s < 10.3 ps-1 at the 95% confidence level.Comment: 18 pages, 3 figures, replaced by version accepted for publication in
Phys.Rev.D; results differ slightly from first versio
Lifespan extension without fertility reduction following dietary addition of the autophagy activator Torin1 in Drosophila melanogaster
Autophagy is a highly conserved mechanism for cellular repair that becomes progressively down-regulated during normal ageing. Hence, manipulations that activate autophagy could increase lifespan. Previous reports show that manipulations to the autophagy pathway can result in longevity extension in yeast, flies, worms and mammals. Under standard nutrition, autophagy is inhibited by the nutrient sensing kinase Target of Rapamycin (TOR). Therefore, manipulations of TOR that increase autophagy may offer a mechanism for extending lifespan. Ideally, such manipulations should be specific and minimise off-target effects, and it is important to discover additional methods for ‘clean’ lifespan manipulation. Here we report an initial study into the effect of up-regulating autophagy on lifespan and fertility in Drosophila melanogaster by dietary addition of Torin1. Activation of autophagy using this selective TOR inhibitor was associated with significantly increased lifespan in both sexes. Torin1 induced a dose-dependent increase in lifespan in once-mated females. There was no evidence of a trade-off between longevity and fecundity or fertility. Torin1-fed females exhibited significantly elevated fecundity, but also elevated egg infertility, resulting in no net change in overall fertility. This supports the idea that lifespan can be extended without trade-offs in fertility and suggest that Torin1 may be a useful tool with which to pursue anti-ageing research
Evaluation of the safety of C-spine clearance by paramedics: design and methodology
<p>Abstract</p> <p>Background</p> <p>Canadian Emergency Medical Services annually transport 1.3 million patients with potential neck injuries to local emergency departments. Less than 1% of those patients have a c-spine fracture and even less (0.5%) have a spinal cord injury. Most injuries occur before the arrival of paramedics, not during transport to the hospital, yet most patients are transported in ambulances immobilized. They stay fully immobilized until a bed is available, or until physician assessment and/or X-rays are complete. The prolonged immobilization is often unnecessary and adds to the burden of already overtaxed emergency medical services systems and crowded emergency departments.</p> <p>Methods/Design</p> <p>The goal of this study is to evaluate the safety and potential impact of an active strategy that allows paramedics to assess very low-risk trauma patients using a validated clinical decision rule, the Canadian C-Spine Rule, in order to determine the need for immobilization during transport to the emergency department.</p> <p>This cohort study will be conducted in Ottawa, Canada with one emergency medical service. Paramedics with this service participated in an earlier validation study of the Canadian C-Spine Rule. Three thousand consecutive, alert, stable adult trauma patients with a potential c-spine injury will be enrolled in the study and evaluated using the Canadian C-Spine Rule to determine the need for immobilization. The outcomes that will be assessed include measures of safety (numbers of missed fractures and serious adverse outcomes), measures of clinical impact (proportion of patients transported without immobilization, key time intervals) and performance of the Rule.</p> <p>Discussion</p> <p>Approximately 40% of all very low-risk trauma patients could be transported safely, without c-spine immobilization, if paramedics were empowered to make clinical decisions using the Canadian C-Spine Rule. This safety study is an essential step before allowing all paramedics across Canada to selectively immobilize trauma victims before transport. Once safety and potential impact are established, we intend to implement a multi-centre study to study actual impact.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov <a href="http://www.clinicaltrials.gov/ct2/show/NCT01188447">NCT01188447</a></p
Early evolution of the LIM homeobox gene family
Background: LIM homeobox (Lhx) transcription factors are unique to the animal lineage and have patterning roles during embryonic development in flies, nematodes and vertebrates, with a conserved role in specifying neuronal identity. Though genes of this family have been reported in a sponge and a cnidarian, the expression patterns and functions of the Lhx family during development in non-bilaterian phyla are not known
Measurement of the branching fraction and CP content for the decay B(0) -> D(*+)D(*-)
This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APS.We report a measurement of the branching fraction of the decay B0→D*+D*- and of the CP-odd component of its final state using the BABAR detector. With data corresponding to an integrated luminosity of 20.4 fb-1 collected at the Υ(4S) resonance during 1999–2000, we have reconstructed 38 candidate signal events in the mode B0→D*+D*- with an estimated background of 6.2±0.5 events. From these events, we determine the branching fraction to be B(B0→D*+D*-)=[8.3±1.6(stat)±1.2(syst)]×10-4. The measured CP-odd fraction of the final state is 0.22±0.18(stat)±0.03(syst).This work is supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the A.P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
Tracing Functional Antigen-Specific CCR6+ Th17 Cells after Vaccination
BACKGROUND: The function of T helper cell subsets in vivo depends on their location, and one hallmark of T cell differentiation is the sequential regulation of migration-inducing chemokine receptor expression. CC-chemokine receptor 6 (CCR6) is a trait of tissue-homing effector T cells and has recently been described as a receptor on T helper type 17 (Th17) cells. Th17 cells are associated with autoimmunity and the defence against certain infections. Although, the polarization of Th cells into Th17 cells has been studied extensively in vitro, the development of those cells during the physiological immune response is still elusive. METHODOLOGY/PRINCIPAL FINDINGS: We analysed the development and functionality of Th17 cells in immune-competent mice during an ongoing immune response. In naïve and vaccinated animals CCR6(+) Th cells produce IL-17. The robust homeostatic proliferation and the presence of activation markers on CCR6(+) Th cells indicate their activated status. Vaccination induces antigen-specific CCR6(+) Th17 cells that respond to in vitro re-stimulation with cytokine production and proliferation. Furthermore, depletion of CCR6(+) Th cells from donor leukocytes prevents recipients from severe disease in experimental autoimmune encephalomyelitis, a model for multiple sclerosis in mice. CONCLUSIONS/SIGNIFICANCE: In conclusion, we defined CCR6 as a specific marker for functional antigen-specific Th17 cells during the immune response. Since IL-17 production reaches the highest levels during the immediate early phase of the immune response and the activation of Th17 cells precedes the Th1 cell differentiation we tent to speculate that this particular Th cell subset may represent a first line effector Th cell subpopulation. Interference with the activation of this Th cell subtype provides an interesting strategy to prevent autoimmunity as well as to establish protective immunity against infections
Measurement of D-s(+) and D-s(*+) production in B meson decays and from continuum e(+)e(-) annihilation at √s=10.6 GeV
This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APSNew measurements of Ds+ and Ds*+ meson production rates from B decays and from qq̅ continuum events near the Υ(4S) resonance are presented. Using 20.8 fb-1 of data on the Υ(4S) resonance and 2.6 fb-1 off-resonance, we find the inclusive branching fractions B(B⃗Ds+X)=(10.93±0.19±0.58±2.73)% and B(B⃗Ds*+X)=(7.9±0.8±0.7±2.0)%, where the first error is statistical, the second is systematic, and the third is due to the Ds+→φπ+ branching fraction uncertainty. The production cross sections σ(e+e-→Ds+X)×B(Ds+→φπ+)=7.55±0.20±0.34pb and σ(e+e-→Ds*±X)×B(Ds+→φπ+)=5.8±0.7±0.5pb are measured at center-of-mass energies about 40 MeV below the Υ(4S) mass. The branching fractions ΣB(B⃗Ds(*)+D(*))=(5.07±0.14±0.30±1.27)% and ΣB(B⃗Ds*+D(*))=(4.1±0.2±0.4±1.0)% are determined from the Ds(*)+ momentum spectra. The mass difference m(Ds+)-m(D+)=98.4±0.1±0.3MeV/c2 is also measured.This work was supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the Swiss NSF, A. P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
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