337 research outputs found

    Role of ACE2 genetic polymorphisms in susceptibility to SARS-CoV-2 among highly exposed but non infected healthcare workers

    Get PDF
    We aim to evaluate the role of single-nucleotide polymorphisms of the angiotensin-converting enzyme 2 in susceptibility to SARS-CoV-2 infection. We included 28 uninfected but highly exposed healthcare workers and 39 hospitalized patients with COVID-19. Thirty-five SNPs were rationally selected. Two variants were associated with increased risk of being susceptible to SARS-CoV-2: the minor A allele in the rs2106806 variant (OR 3.75 [95% CI 1.23-11.43]) and the minor T allele in the rs6629110 variant (OR 3.39 [95% CI 1.09-10.56]). Evaluating the role of genetic variants in susceptibility to SARS-CoV-2 infection could help identify more vulnerable individuals and suggest potential drug targets for COVID-19 patients.This work was supported by Instituto de Salud Carlos III: [grant number AC17/00019,COV20/00349,PI18/00154,PT17/0019]; Merck, Sharp & Dohme: [Ref IISP 59181].S

    Jasmonate-dependent modifications of the pectin matrix during potato development function as a defense mechanism targeted by Dickeya dadantii virulence factors

    Full text link
    The plant cell wall constitutes an essential protection barrier against pathogen attack. In addition, cell-wall disruption leads to accumulation of jasmonates (JAs), which are key signaling molecules for activation of plant inducible defense responses. However, whether JAs in return modulate the cell-wall composition to reinforce this defensive barrier remains unknown. The enzyme 13-allene oxide synthase (13-AOS) catalyzes the first committed step towards biosynthesis of JAs. In potato (Solanum tuberosum), there are two putative St13-AOS genes, which we show here to be differentially induced upon wounding. We also determine that both genes complement an Arabidopsis aos null mutant, indicating that they encode functional 13-AOS enzymes. Indeed, transgenic potato plants lacking both St13-AOS genes (CoAOS1/2 lines) exhibited a significant reduction of JAs, a concomitant decrease in wound-responsive gene activation, and an increased severity of soft rot disease symptoms caused by Dickeya dadantii. Intriguingly, a hypovirulent D. dadantii pel strain lacking the five major pectate lyases, which causes limited tissue maceration on wild-type plants, regained infectivity in CoAOS1/2 plants. In line with this, we found differences in pectin methyl esterase activity and cell-wall pectin composition between wild-type and CoAOS1/2 plants. Importantly, wild-type plants had pectins with a lower degree of methyl esterification, which are the substrates of the pectate lyases mutated in the pel strain. These results suggest that, during development of potato plants, JAs mediate modification of the pectin matrix to form a defensive barrier that is counteracted by pectinolytic virulence factors from D. dadantii

    Annual short-burst mass anthelmintic administration reduces tuberculosis severity but not prevalence in a wildlife reservoir

    Get PDF
    Introduction: Tuberculosis (TB), caused by the Mycobacterium tuberculosis complex (MTC), is an important disease in both human and animal systems. Helminths are commonly found in coinfection with MTC and TB is often exacerbated in such coinfections. Long-term anthelmintic administration, to control helminths, can improve a host’s ability to control MTC infection. Mass drug administration programmes, in which anthelmintics are given only once or twice a year, leaving periods where helminth reinfection can occur, are common in both human and domestic animal populations. To date, the effect of such intermittent control programmes on MTC infection and severity has not been explored. Methods: Here we investigate the consequences of a ten-day, annual, mass ivermectin administration on TB prevalence and severity in free-ranging juvenile and yearling (<2 years) wild boar (Sus scrofa). Results: This single annual anthelmintic treatment administered over six years reduced TB severity. Further, the proportion of wild boar with severe TB continued to decrease with successive treatments. TB prevalence, however, did not decrease significantly over the course of the study. Discussion: While ivermectin has direct anti-mycobacterial effects in vitro, the short duration of treatment means that the reduction in TB severity we observe in wild boar is unlikely to be accounted for by such a direct mechanism. Disruption of the helminth community and subsequent modification or enhancement of the host immune response is a potential mechanism. Future work should examine the consequences of annual anthelmintic drug administration on helminth community composition and structure and on the host immunological responses through time

    Search for CP violation in D+→K−K+π+D^{+} \to K^{-}K^{+}\pi^{+} decays

    Get PDF
    A model-independent search for direct CP violation in the Cabibbo suppressed decay D+→K−K+π+D^+ \to K^- K^+\pi^+ in a sample of approximately 370,000 decays is carried out. The data were collected by the LHCb experiment in 2010 and correspond to an integrated luminosity of 35 pb−1^{-1}. The normalized Dalitz plot distributions for D+D^+ and D−D^- are compared using four different binning schemes that are sensitive to different manifestations of CP violation. No evidence for CP asymmetry is found.Comment: 13 pages, 8 figures, submitted to Phys. Rev.

    First observation of the decay Bˉs0→D0K∗0\bar{B}^0_s \to D^0 K^{*0} and a measurement of the ratio of branching fractions B(Bˉs0→D0K∗0)B(Bˉ0→D0ρ0)\frac{{\cal B}(\bar{B}^0_s \to D^0 K^{*0})}{{\cal B}(\bar{B}^0 \to D^0 \rho^0)}

    Get PDF
    The first observation of the decay Bˉs0→D0K∗0\bar{B}^0_s \to D^0 K^{*0} using pppp data collected by the LHCb detector at a centre-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 36 pb−1^{-1}, is reported. A signal of 34.4±6.834.4 \pm 6.8 events is obtained and the absence of signal is rejected with a statistical significance of more than nine standard deviations. The Bˉs0→D0K∗0\bar{B}^0_s \to D^0 K^{*0} branching fraction is measured relative to that of Bˉ0→D0ρ0\bar{B}^0 \to D^0 \rho^0: B(Bˉs0→D0K∗0)B(Bˉ0→D0ρ0)=1.48±0.34±0.15±0.12\frac{{\cal B}(\bar{B}^0_s \to D^0 K^{*0})}{{\cal B}(\bar{B}^0 \to D^0 \rho^0)} = 1.48 \pm 0.34 \pm 0.15 \pm 0.12, where the first uncertainty is statistical, the second systematic and the third is due to the uncertainty on the ratio of the B0B^0 and Bs0B^0_s hadronisation fractions.Comment: 10 pages, 3 figures, submitted to Phys. Lett. B; ISSN 0370-269

    Measurement of the ratio of branching fractions BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma)

    Get PDF
    The ratio of branching fractions of the radiative B decays B0 -> K*0 gamma and Bs0 -> phi gamma has been measured using 0.37 fb-1 of pp collisions at a centre of mass energy of sqrt(s) = 7 TeV, collected by the LHCb experiment. The value obtained is BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma) = 1.12 +/- 0.08 ^{+0.06}_{-0.04} ^{+0.09}_{-0.08}, where the first uncertainty is statistical, the second systematic and the third is associated to the ratio of fragmentation fractions fs/fd. Using the world average for BR(B0 -> K*0 gamma) = (4.33 +/- 0.15) x 10^{-5}, the branching fraction BR(Bs0 -> phi gamma) is measured to be (3.9 +/- 0.5) x 10^{-5}, which is the most precise measurement to date.Comment: 15 pages, 1 figure, 2 table

    Measurement of the CKM angle Îł from a combination of B±→Dh± analyses

    Get PDF
    A combination of three LHCb measurements of the CKM angle Îł is presented. The decays B±→D K± and B±→Dπ± are used, where D denotes an admixture of D0 and D0 mesons, decaying into K+K−, π+π−, K±π∓, K±π∓π±π∓, K0Sπ+π−, or K0S K+K− ïŹnal states. All measurements use a dataset corresponding to 1.0 fb−1 of integrated luminosity. Combining results from B±→D K± decays alone a best-ïŹt value of Îł =72.0◩ is found, and conïŹdence intervals are set Îł ∈ [56.4,86.7]◩ at 68% CL, Îł ∈ [42.6,99.6]◩ at 95% CL. The best-ïŹt value of Îł found from a combination of results from B±→Dπ± decays alone, is Îł =18.9◩, and the conïŹdence intervals Îł ∈ [7.4,99.2]◩ âˆȘ [167.9,176.4]◩ at 68% CL are set, without constraint at 95% CL. The combination of results from B± → D K± and B± → Dπ± decays gives a best-ïŹt value of Îł =72.6◩ and the conïŹdence intervals Îł ∈ [55.4,82.3]◩ at 68% CL, Îł ∈ [40.2,92.7]◩ at 95% CL are set. All values are expressed modulo 180◩, and are obtained taking into account the effect of D0–D0 mixing

    Study of the production of Λb0\Lambda_b^0 and B‟0\overline{B}^0 hadrons in pppp collisions and first measurement of the Λb0→J/ψpK−\Lambda_b^0\rightarrow J/\psi pK^- branching fraction

    Get PDF
    The product of the Λb0\Lambda_b^0 (B‟0\overline{B}^0) differential production cross-section and the branching fraction of the decay Λb0→J/ψpK−\Lambda_b^0\rightarrow J/\psi pK^- (B‟0→J/ψK‟∗(892)0\overline{B}^0\rightarrow J/\psi\overline{K}^*(892)^0) is measured as a function of the beauty hadron transverse momentum, pTp_{\rm T}, and rapidity, yy. The kinematic region of the measurements is pT<20 GeV/cp_{\rm T}<20~{\rm GeV}/c and 2.0<y<4.52.0<y<4.5. The measurements use a data sample corresponding to an integrated luminosity of 3 fb−13~{\rm fb}^{-1} collected by the LHCb detector in pppp collisions at centre-of-mass energies s=7 TeV\sqrt{s}=7~{\rm TeV} in 2011 and s=8 TeV\sqrt{s}=8~{\rm TeV} in 2012. Based on previous LHCb results of the fragmentation fraction ratio, fΛB0/fdf_{\Lambda_B^0}/f_d, the branching fraction of the decay Λb0→J/ψpK−\Lambda_b^0\rightarrow J/\psi pK^- is measured to be \begin{equation*} \mathcal{B}(\Lambda_b^0\rightarrow J/\psi pK^-)= (3.17\pm0.04\pm0.07\pm0.34^{+0.45}_{-0.28})\times10^{-4}, \end{equation*} where the first uncertainty is statistical, the second is systematic, the third is due to the uncertainty on the branching fraction of the decay B‟0→J/ψK‟∗(892)0\overline{B}^0\rightarrow J/\psi\overline{K}^*(892)^0, and the fourth is due to the knowledge of fΛb0/fdf_{\Lambda_b^0}/f_d. The sum of the asymmetries in the production and decay between Λb0\Lambda_b^0 and Λ‟b0\overline{\Lambda}_b^0 is also measured as a function of pTp_{\rm T} and yy. The previously published branching fraction of Λb0→J/ψpπ−\Lambda_b^0\rightarrow J/\psi p\pi^-, relative to that of Λb0→J/ψpK−\Lambda_b^0\rightarrow J/\psi pK^-, is updated. The branching fractions of Λb0→Pc+(→J/ψp)K−\Lambda_b^0\rightarrow P_c^+(\rightarrow J/\psi p)K^- are determined.Comment: 29 pages, 19figures. All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-032.htm
    • 

    corecore