83 research outputs found

    Acid fast staining in formalin-fixed tissue specimen of patients with extrapulmonary tuberculosis

    Get PDF
    Diagnosis of extrapulmonary tuberculosis (EPTB) is difficult owing to low number of bacilli in the specimens, lack of adequate sample and non-uniform distribution of bacteria in tissues. The aim of this study was to investigate the utility of acid-fast bacilli (AFB) staining in biopsy specimens with typical granulomatous inflammation in patients with extrapulmonary tuberculosis and some related predictors.This study included 226 tissue biopsies of patients with EPTB showing typical granulomatous inflammation. Ziehl-Neelsen staining was performed for acid fast bacilli on paraffin embedded sections of tissue blocks. The most common site of involvement was pleura followed by vertebral and lymph nodes. Past history of pulmonary tuberculosis was positive in 46% of patients. The overall AFB positivity in specimens was 26.1%. The most positivity was in pleural TB (35.2%) and the least was in bone and joints TB (4.8%). There was significant association between site of involvement and AFB positivity (p=0.042). In multivariate logistic regression model, previous history of pulmonary tuberculosis was strongly associated with AFB positivity. Our study showed somewhat higher rate of smear positivity for acid fast bacilli in tissue specimen with typical pathology in some types of EPTB especially in patients with history of pulmonary tuberculosis. Despite low sensitivity, this method should be performed in patients suspected to EPTB especially in developing counties where new modality is not routinely available

    Linear vs. nonlinear effects for nonlinear Schrodinger equations with potential

    Full text link
    We review some recent results on nonlinear Schrodinger equations with potential, with emphasis on the case where the potential is a second order polynomial, for which the interaction between the linear dynamics caused by the potential, and the nonlinear effects, can be described quite precisely. This includes semi-classical regimes, as well as finite time blow-up and scattering issues. We present the tools used for these problems, as well as their limitations, and outline the arguments of the proofs.Comment: 20 pages; survey of previous result

    Network Topology Effecton QoS Delivering in Survivable DWDM Optical Networks, Journal of Telecommunications and Information Technology, 2009, nr 1

    Get PDF
    The quality of service (QoS) is an important and considerable issue in designing survivable dense wavelength division multiplexing (DWDM) backbones for IP networks. This paper investigates the effect of network topology on QoS delivering in survivable DWDM optical transport networks using bandwidth/load ratio and design flexibility metrics. The dedicated path protection architecture is employed to establish diverse working and spare lightpaths between each node pair in demand matrix for covering a single link failure model. The simulation results, obtained for the Pan-European and ARPA2 test bench networks, demonstrate that the network topology has a great influence on QoS delivering by network at optical layer for different applications. The Pan-European network, a more connected network, displays better performance than ARPA2 network for both bandwidth/load ratio and design flexibility metrics

    The natural organosulfur compound dipropyltetrasulfide prevents HOCL-induced systemic sclerosis in the mouse

    Get PDF
    PublishedArticleIntroduction: The aim of this study was to test the naturally occurring organosulfur compound dipropyltetrasulfide (DPTTS) found in plants, which has antibiotic and anti-cancer properties, as a treatment of HOCl-induced systemic sclerosis in the mouse. Methods: The pro-oxidative, anti-proliferative and cytotoxic effects of DPTTS were evaluated ex vivo on fibroblasts from normal and HOCl-mice. In vivo, the anti-fibrotic and immunomodulating properties of DPTTS were evaluated in the skin and lungs of HOCl-mice. Results: H2O2 production was higher in fibroblasts derived from HOCl-mice than in normal fibroblasts (P<0.05). DPTTS did not increase H2O2 production in normal fibroblasts, but DPTTS dose-dependently increased H2O2 production in HOCl-fibroblasts (P<0.001 with 40ÎŒM DPTTS). Because H2O2 reached a lethal threshold in cells from HOCl-mice, the anti-proliferative, cytotoxic and pro-apoptotic effects of DPTTS were significantly higher in HOCl-fibroblasts than for normal fibroblasts. In vivo, DPTTS decreased dermal thickness (P<0.001), collagen content in skin (P<0.01) and lungs (P<0.05), SMA (P<0.01) and pSMAD2/3 (P<0.01) expression in skin, formation of advanced oxidation protein products and anti-DNA topoisomerase-1 antibodies in serum (P<0.05) versus untreated HOCl- mice. Moreover, in HOCl-mice, DPTTS reduced splenic B cell counts (P<0.01), the proliferative rates of B-splenocytes stimulated by lipopolysaccharide (P<0.05) and T-splenocytes stimulated by anti-CD3/CD28 mAb (P<0.001). Ex vivo, it also reduced the production of IL-4 and IL-13 by activated T cells (P<0.05 in both cases). Conclusions: The natural organosulfur compound DPTTS prevents skin and lung fibrosis in the mouse through the selective killing of diseased fibroblasts and its immunomodulating properties. DPTTS may be a potential treatment of Systemic sclerosis.This work was supported by European Community’s Seventh Framework Programme (FP7/2007-2013) under grant agreement 215009 RedCat for financial support. The authors are grateful to Ms Agnes for her excellent typing of the manuscript

    Traveling waves for nonlinear Schr\"odinger equations with nonzero conditions at infinity, II

    Full text link
    We prove the existence of nontrivial finite energy traveling waves for a large class of nonlinear Schr\"odinger equations with nonzero conditions at infinity (includindg the Gross-Pitaevskii and the so-called "cubic-quintic" equations) in space dimension N≄2 N \geq 2. We show that minimization of the energy at fixed momentum can be used whenever the associated nonlinear potential is nonnegative and it gives a set of orbitally stable traveling waves, while minimization of the action at constant kinetic energy can be used in all cases. We also explore the relationship between the families of traveling waves obtained by different methods and we prove a sharp nonexistence result for traveling waves with small energy.Comment: Final version, accepted for publication in the {\it Archive for Rational Mechanics and Analysis.} The final publication is available at Springer via http://dx.doi.org/10.1007/s00205-017-1131-

    Asymptotic expansions of the solutions of the Cauchy problem for nonlinear parabolic equations

    Full text link
    Let uu be a solution of the Cauchy problem for the nonlinear parabolic equation ∂tu=Δu+F(x,t,u,∇u)inRN×(0,∞),u(x,0)=φ(x)inRN, \partial_t u=\Delta u+F(x,t,u,\nabla u) \quad in \quad{\bf R}^N\times(0,\infty), \quad u(x,0)=\varphi(x)\quad in \quad{\bf R}^N, and assume that the solution uu behaves like the Gauss kernel as t→∞t\to\infty. In this paper, under suitable assumptions of the reaction term FF and the initial function φ\varphi, we establish the method of obtaining higher order asymptotic expansions of the solution uu as t→∞t\to\infty. This paper is a generalization of our previous paper, and our arguments are applicable to the large class of nonlinear parabolic equations

    COMPETITIVE OR WEAK COOPERATIVE STOCHASTIC LOTKA-VOLTERRA SYSTEMS CONDITIONED TO NON-EXTINCTION

    Get PDF
    International audienceWe are interested in the long time behavior of a two-type density-dependent biological population conditioned to non-extinction, in both cases of competition or weak cooperation between the two species. This population is described by a stochastic Lotka-Volterra system, obtained as limit of renormalized interacting birth and death processes. The weak cooperation assumption allows the system not to blow up. We study the existence and uniqueness of a quasi-stationary distribution, that is convergence to equilibrium conditioned to non extinction. To this aim we generalize in two-dimensions spectral tools developed for one-dimensional generalized Feller diffusion processes. The existence proof of a quasi-stationary distribution is reduced to the one for a dd-dimensional Kolmogorov diffusion process under a symmetry assumption. The symmetry we need is satisfied under a local balance condition relying the ecological rates. A novelty is the outlined relation between the uniqueness of the quasi-stationary distribution and the ultracontractivity of the killed semi-group. By a comparison between the killing rates for the populations of each type and the one of the global population, we show that the quasi-stationary distribution can be either supported by individuals of one (the strongest one) type or supported by individuals of the two types. We thus highlight two different long time behaviors depending on the parameters of the model: either the model exhibits an intermediary time scale for which only one type (the dominant trait) is surviving, or there is a positive probability to have coexistence of the two species

    Characterization of SARS-CoV-2 nucleocapsid protein reveals multiple functional consequences of the C-terminal domain

    Get PDF
    Nucleocapsid (N) encoded by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) plays key roles in the replication cycle and is a critical serological marker. Here, we characterize essential biochemical properties of N and describe the utility of these insights in serological studies. We define N domains important for oligomerization and RNA binding and show that N oligomerization provides a high-affinity RNA-binding platform. We also map the RNA-binding interface, showing protection in the N-terminal domain and linker region. In addition, phosphorylation causes reduction of RNA binding and redistribution of N from liquid droplets to loose coils, showing how N-RNA accessibility and assembly may be regulated by phosphorylation. Finally, we find that the C-terminal domain of N is the most immunogenic, based on antibody binding to patient samples. Together, we provide a biochemical description of SARS-CoV-2 N and highlight the value of using N domains as highly specific and sensitive diagnostic markers

    The effects of upper and lower limb exercise on the microvascular reactivity in limited cutaneous systemic sclerosis patients

    Get PDF
    Background: Aerobic exercise in general and high intensity interval training (HIIT) specifically is known to improve vascular function in a range of clinical conditions. HIIT in particular has demonstrated improvements in clinical outcomes, in conditions that have a strong macroangiopathic component. Nevertheless, the effect of HIIT on microcirculation in systemic sclerosis (SSc) patients is yet to be investigated. Therefore, the purpose of the study was to compare the effects of two HIIT protocols (cycle and arm cranking) on the microcirculation of the digital area in SSc patients. Methods: Thirty four limited cutaneous SSc patients (65.3 ± 11.6 years old) were randomly allocated in three groups (cycling, arm cranking and control group). The exercise groups underwent a twelve-week exercise program twice per week. All patients performed the baseline and post-exercise intervention measurements where physical fitness, functional ability, transcutaneous oxygen tension (ΔtcpO2), body composition and quality of life were assessed. Endothelial-dependent as well as-independent vasodilation were assessed in the middle and index fingers using LDF and incremental doses of acetylcholine (ACh) and sodium nitroprusside (SNP). Cutaneous flux data were expressed as cutaneous vascular conductance (CVC). Results: Peak oxygen uptake increased in both exercise groups (p<0.01, d=1.36). ΔtcpO2 demonstrated an increase in the arm cranking group only, with a large effect, but not found statistically significant,(p=0.59, d=0.93). Endothelial-dependent vasodilation improvement was greater in the arm cranking (p<0.05, d=1.07) in comparison to other groups. Both exercise groups improved life satisfaction (p<0.001) as well as reduced discomfort and pain due to Raynaud's phenomenon (p<0.05). Arm cranking seems to be the preferred mode of exercise for study participants as compared to cycling (p<0.05). No changes were observed in the body composition or the functional ability in both exercise groups. Conclusion: Our results suggest that arm cranking has the potential to improve the microvascular endothelial function in SSc patients. Also notably, our recommended training dose (e.g., a 12-week HIIT program, twice per week), appeared to be sufficient and tolerable for this population. Future research should focus on exploring the feasibility of a combined exercise such as aerobic and resistance training by assessing individual's experience and the quality of life in SSc patients. Trial registration: ClinicalTrials.gov (NCT number): NCT03058887, February 23, 2017, https://clinicaltrials.gov/ct2/show/NCT03058887?term=NCT03058887&rank=1 Key words: High intensity interval training, vascular function, quality of lif

    Orbital stability of spherical galactic models

    Get PDF
    International audienceWe consider the three dimensional gravitational Vlasov Poisson system which is a canonical model in astrophysics to describe the dynamics of galactic clusters. A well known conjecture is the stability of spherical models which are nonincreasing radially symmetric steady states solutions. This conjecture was proved at the linear level by several authors in the continuation of the breakthrough work by Antonov in 1961. In a previous work, we derived the stability of anisotropic models under {\it spherically symmetric perturbations} using fundamental monotonicity properties of the Hamiltonian under suitable generalized symmetric rearrangements first observed in the physics litterature. In this work, we show how this approach combined with a {\it new generalized} Antonov type coercivity property implies the orbital stability of spherical models under general perturbations
    • 

    corecore