965 research outputs found

    THG113.31, a specific PGF2alpha receptor antagonist, induces human myometrial relaxation and BKCa channel activation

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    BACKGROUND: PGF2alpha exerts a significant contractile effect on myometrium and is central to human labour. THG113.31, a specific non-competitive PGF2alpha receptor (FP) antagonist, exerts an inhibitory effect on myometrial contractility. The BKCa channel is ubiquitously encountered in human uterine tissue and plays a significant role in modulating myometrial cell membrane potential and excitability. The objective of this study was to investigate potential BKCa channel involvement in the response of human myometrium to THG113.31. METHODS: Single and whole-cell electrophysiological BKCa channel recordings from freshly dispersed myocytes, were investigated in the presence and absence of THG113.31. Functional studies investigated the effects of THG113.31 on isolated spontaneous myometrial contractions, in the presence and absence of the BKCa channel blocker, iberiotoxin. RESULTS: Single channel recordings identified the BKCa channel as a target of THG113.31. THG113.31 significantly increased the open state probability of these channels [control 0.023+/-0.006; 10 microM THG113.31 0.087+/-0.012 (P = 0.009); and 50 microM THG113.31 0.1356+/-0.018 (P = 0.001)]. In addition, THG113.31 increased whole-cell BKCa currents over a range of membrane potentials, and this effect was reversed by 100 nanoM IbTX. Isometric tension studies demonstrated that THG113.31 exerted a significant concentration-dependent relaxant effect on human myometrial tissue and pre-incubation of strips with IbTX abolished this effect on spontaneously occurring contractions. CONCLUSION: These data suggests that activation of the BKCa channel may contribute, at least partially, to the uterorelaxant effect of THG113.31

    Anti-malarial prescriptions in three health care facilities after the emergence of chloroquine resistance in Niakhar, Senegal (1992–2004)

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    <p>Abstract</p> <p>Background</p> <p>In the rural zone of Niakhar in Senegal, the first therapeutic failures for chloroquine (CQ) were observed in 1992. In 2003, the national policy regarding first-line treatment of uncomplicated malaria was modified, replacing CQ by a transitory bi-therapy amodiaquine/sulphadoxine-pyrimethamine (AQ/SP), before the implementation of artemisinin-based combination therapy (ACT) in 2006.</p> <p>The aims of the study were to assess the evolution of anti-malarial prescriptions in three health care facilities between 1992 and 2004, in parallel with increasing CQ resistance in the region.</p> <p>Methods</p> <p>The study was conducted in the area of Niakhar, a demographic surveillance site located in a sahelo-sudanese region of Senegal, with mesoendemic and seasonal malaria transmission. Health records of two public health centres and a private catholic dispensary were collected retrospectively to cover the period 1992–2004.</p> <p>Results</p> <p>Records included 110,093 consultations and 292,965 prescribed treatments. Twenty-five percent of treatments were anti-malarials, prescribed to 49% of patients. They were delivered all year long, but especially during the rainy season, and 20% of patients with no clinical malaria diagnosis received anti-malarials. Chloroquine and quinine represented respectively 55.7% and 34.6% of prescribed anti-malarials. Overall, chloroquine prescriptions rose from 1992 to 2000, in parallel with clinical malaria; then the CQ prescription rate decreased from 2000 and was concomitant with the rise of SP and the persistence of quinine use. AQ and SP were mainly used as bi-therapy after 2003, at the time of national treatment policy change.</p> <p>Conclusion</p> <p>The results show the overall level of anti-malarial prescription in the study area for a considerable number of patients over a large period of time. Even though resistance to CQ rapidly increased from 1992 to 2001, no change in CQ prescription was observed until the early 2000s, possibly due to the absence of an obvious decrease in CQ effectiveness, a lack of therapeutic options or a blind follow-up of national guidelines.</p

    Anti-Apoptotic Machinery Protects the Necrotrophic Fungus Botrytis cinerea from Host-Induced Apoptotic-Like Cell Death during Plant Infection

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    Necrotrophic fungi are unable to occupy living plant cells. How such pathogens survive first contact with living host tissue and initiate infection is therefore unclear. Here, we show that the necrotrophic grey mold fungus Botrytis cinerea undergoes massive apoptotic-like programmed cell death (PCD) following germination on the host plant. Manipulation of an anti-apoptotic gene BcBIR1 modified fungal response to PCD-inducing conditions. As a consequence, strains with reduced sensitivity to PCD were hyper virulent, while strains in which PCD was over-stimulated showed reduced pathogenicity. Similarly, reduced levels of PCD in the fungus were recorded following infection of Arabidopsis mutants that show enhanced susceptibility to B. cinerea. When considered together, these results suggest that Botrytis PCD machinery is targeted by plant defense molecules, and that the fungal anti-apoptotic machinery is essential for overcoming this host-induced PCD and hence, for establishment of infection. As such, fungal PCD machinery represents a novel target for fungicides and antifungal drugs

    Calcitonin gene-related peptide (CGRP) and its receptor components in human and rat spinal trigeminal nucleus and spinal cord at C1-level

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    <p>Abstract</p> <p>Background</p> <p>Calcitonin gene-related peptide (CGRP) has a key role in migraine pathophysiology and is associated with activation of the trigeminovascular system. The trigeminal ganglion, storing CGRP and its receptor components, projects peripheral to the intracranial vasculature and central to regions in the brainstem with Aδ- and C-fibers; this constitutes an essential part of the pain pathways activated in migraine attacks. Therefore it is of importance to identify the regions within the brainstem that processes nociceptive information from the trigeminovascular system, such as the spinal trigeminal nucleus (STN) and the C1-level of the spinal cord. Immunohistochemistry was used to study the distribution and relation between CGRP and its receptor components - calcitonin receptor-like receptor (CLR) and receptor activity modifying protein 1 (RAMP1) - in human and rat STN and at the C1-level, using a set of newly well characterized antibodies. In addition, double-stainings with CGRP and myelin basic protein (MBP, myelin), synaptophysin (synaptic vesicles) or IB4 (C-fibers in general) were performed.</p> <p>Results</p> <p>In the STN, the highest density of CGRP immunoreactive fibers were found in a network around fiber bundles in the superficial laminae. CLR and RAMP1 expression were predominately found in fibers in the spinal trigeminal tract region, with some fibers spanning into the superficial laminae. Co-localization between CGRP and its receptor components was not noted. In C1, CGRP was expressed in fibers of laminae I and II. The CGRP staining was similar in rat, except for CGRP positive neurons that were found close to the central canal. In C1, the receptor components were detected in laminae I and II, however these fibers were distinct from fibers expressing CGRP as verified by confocal microscopy.</p> <p>Conclusions</p> <p>This study demonstrates the detailed expression of CGRP and its receptor components within STN in the brainstem and in the spinal cord at C1-level, and shows the possibility of CGRP acting postjunctionally in these areas putatively involved in primary headaches.</p

    Studying the Underlying Event in Drell-Yan and High Transverse Momentum Jet Production at the Tevatron

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    We study the underlying event in proton-antiproton collisions by examining the behavior of charged particles (transverse momentum pT > 0.5 GeV/c, pseudorapidity |\eta| < 1) produced in association with large transverse momentum jets (~2.2 fb-1) or with Drell-Yan lepton-pairs (~2.7 fb-1) in the Z-boson mass region (70 < M(pair) < 110 GeV/c2) as measured by CDF at 1.96 TeV center-of-mass energy. We use the direction of the lepton-pair (in Drell-Yan production) or the leading jet (in high-pT jet production) in each event to define three regions of \eta-\phi space; toward, away, and transverse, where \phi is the azimuthal scattering angle. For Drell-Yan production (excluding the leptons) both the toward and transverse regions are very sensitive to the underlying event. In high-pT jet production the transverse region is very sensitive to the underlying event and is separated into a MAX and MIN transverse region, which helps separate the hard component (initial and final-state radiation) from the beam-beam remnant and multiple parton interaction components of the scattering. The data are corrected to the particle level to remove detector effects and are then compared with several QCD Monte-Carlo models. The goal of this analysis is to provide data that can be used to test and improve the QCD Monte-Carlo models of the underlying event that are used to simulate hadron-hadron collisions.Comment: Submitted to Phys.Rev.

    Precision measurement of the top quark mass from dilepton events at CDF II

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    We report a measurement of the top quark mass, M_t, in the dilepton decay channel of ttˉb+νbˉνˉt\bar{t}\to b\ell'^{+}\nu_{\ell'}\bar{b}\ell^{-}\bar{\nu}_{\ell} using an integrated luminosity of 1.0 fb^{-1} of p\bar{p} collisions collected with the CDF II detector. We apply a method that convolutes a leading-order matrix element with detector resolution functions to form event-by-event likelihoods; we have enhanced the leading-order description to describe the effects of initial-state radiation. The joint likelihood is the product of the likelihoods from 78 candidate events in this sample, which yields a measurement of M_{t} = 164.5 \pm 3.9(\textrm{stat.}) \pm 3.9(\textrm{syst.}) \mathrm{GeV}/c^2, the most precise measurement of M_t in the dilepton channel.Comment: 7 pages, 2 figures, version includes changes made prior to publication by journa

    Measurement of the Ratios of Branching Fractions B(Bs -> Ds pi pi pi) / B(Bd -> Dd pi pi pi) and B(Bs -> Ds pi) / B(Bd -> Dd pi)

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    Using 355 pb^-1 of data collected by the CDF II detector in \ppbar collisions at sqrt{s} = 1.96 TeV at the Fermilab Tevatron, we study the fully reconstructed hadronic decays B -> D pi and B -> D pi pi pi. We present the first measurement of the ratio of branching fractions B(Bs -> Ds pi pi pi) / B(Bd -> Dd pi pi pi) = 1.05 pm 0.10 (stat) pm 0.22 (syst). We also update our measurement of B(Bs -> Ds pi) / B(Bd -> Dd pi) to 1.13 pm 0.08 (stat) pm 0.23 (syst) improving the statistical uncertainty by more than a factor of two. We find B(Bs -> Ds pi) = [3.8 pm 0.3 (stat) pm 1.3 (syst)] \times 10^{-3} and B(Bs -> Ds pi pi pi) = [8.4 pm 0.8 (stat) pm 3.2 (syst)] \times 10^{-3}.Comment: 7 pages, 2 figure

    Cross Section Measurements of High-pTp_T Dilepton Final-State Processes Using a Global Fitting Method

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    We present a new method for studying high-pTp_T dilepton events (e±ee^{\pm}e^{\mp}, μ±μ\mu^{\pm}\mu^{\mp}, e±μe^{\pm}\mu^{\mp}) and simultaneously extracting the production cross sections of ppˉttˉp\bar{p} \to t\bar{t}, ppˉW+Wp\bar{p} \to W^+W^-, and p\bar{p} \to \ztt at a center-of-mass energy of s=1.96\sqrt{s} = 1.96 TeV. We perform a likelihood fit to the dilepton data in a parameter space defined by the missing transverse energy and the number of jets in the event. Our results, which use 360pb1360 {\rm pb^{-1}} of data recorded with the CDF II detector at the Fermilab Tevatron Collider, are σ(ttˉ)=8.52.2+2.7\sigma(t\bar{t}) = 8.5_{-2.2}^{+2.7} pb, σ(W+W)=16.34.4+5.2\sigma(W^+W^-) = 16.3^{+5.2}_{-4.4} pb, and \sigma(\ztt) =291^{+50}_{-46} pb.Comment: 20 pages, 2 figures, to be submitted to PRD-R

    Measurement of the Dipion Mass Spectrum in X(3872) -> J/Psi Pi+ Pi- Decays

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    We measure the dipion mass spectrum in X(3872)--> J/Psi Pi+ Pi- decays using 360 pb-1 of pbar-p collisions at 1.96 TeV collected with the CDF II detector. The spectrum is fit with predictions for odd C-parity (3S1, 1P1, and 3DJ) charmonia decaying to J/Psi Pi+ Pi-, as well as even C-parity states in which the pions are from Rho0 decay. The latter case also encompasses exotic interpretations, such as a D0-D*0Bar molecule. Only the 3S1 and J/Psi Rho hypotheses are compatible with our data. Since 3S1 is untenable on other grounds, decay via J/Psi Rho is favored, which implies C=+1 for the X(3872). Models for different J/Psi-Rho angular momenta L are considered. Flexibility in the models, especially the introduction of Rho-Omega interference, enable good descriptions of our data for both L=0 and 1.Comment: 7 pages, 4 figures -- Submitted to Phys. Rev. Let

    Top Quark Mass Measurement from Dilepton Events at CDF II with the Matrix-Element Method

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    We describe a measurement of the top quark mass using events with two charged leptons collected by the CDF II detector from ppˉp\bar{p} collisions with s=1.96\sqrt s = 1.96 TeV at the Fermilab Tevatron. The likelihood in top mass is calculated for each event by convoluting the leading order matrix element describing qqˉttˉbνbˉνq\bar{q} \to t\bar{t} \to b\ell\nu_{\ell}\bar{b}\ell'\nu_{\ell'} with detector resolution functions. The presence of background events in the data sample is modeled using similar calculations involving the matrix elements for major background processes. In a data sample with integrated luminosity of 340 pb1^{-1}, we observe 33 candidate events and measure Mtop=165.2±6.1(stat.)±3.4(syst.) GeV/c2.M_{top} = 165.2 \pm 6.1(\textrm{stat.}) \pm 3.4(\textrm{syst.}) \mathrm{~GeV}/c^2. This measurement represents the first application of this method to events with two charged leptons and is the most precise single measurement of the top quark mass in this channel.Comment: 21 pages, 14 figure
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