Oral nitrate supplementation improves cardiovascular risk markers in COPD: ON-BC a randomised controlled trial

BACKGROUND: Short term studies suggest that dietary nitrate supplementation may improve cardiovascular risk profile, lowering blood pressure (BP) and enhancing endothelial function. It is not clear if these beneficial effects are sustained and whether they apply in people with COPD, who have a worse cardiovascular profile than those without COPD. Nitrate-rich beetroot juice BRJ (NR-BRJ) is a convenient dietary source of nitrate. METHODS: The ON-BC trial was a randomized, double-blind, placebo-controlled parallel group study in stable COPD patients with home systolic BP (SBP) measurement ≥130 mmHg. Participants were randomly allocated (1:1) using computer-generated, block randomization to either 70 mL of NR-BRJ (400 mg NO3 -) (n=40) or an otherwise identical nitrate-depleted placebo juice Pl-BRJ (0 mg NO3 -) (n=41), once daily for 12 weeks. The primary endpoint was between group change in home SBP measurement. Secondary outcomes included change in 6-minute walking distance (6MWD) and measures of endothelial function (reactive hyperaemia index (RHI) and augmentation index (AIx75)) using an EndoPAT device. Plasma nitrate and platelet function were also measured. RESULTS: Compared to placebo, active treatment lowered SBP (Hodges-Lemman treatment effect MD[95% CI]; -4.5[-3.0 to -5.9] improved 6MWD (+30.0 m [15.7 to 44.2], p<0.001), RHI +0.34 (0.03 to 0.63) p=0.03, and AIx75 -7.61% [-14.3 to -0.95], p=0.026. CONCLUSIONS: In people with COPD, prolonged dietary nitrate supplementation in the form of beetroot juice produces a sustained reduction in BP, associated with an improvement in endothelial function and exercise capacity

Model of For3p-Mediated Actin Cable Assembly in Fission Yeast

Formin For3p nucleates actin cables at the tips of fission yeast cells for polarized cell growth. The results of prior experiments have suggested a possible mechanism for actin cable assembly that involves association of For3p near cell tips, For3p-mediated actin polymerization, retrograde flow of actin cables toward the cell center, For3p dissociation from cell tips, and cable disassembly. We used analytical and computational modeling to test the validity and implications of the proposed coupled For3p/actin mechanism. We compared the model to prior experiments quantitatively and generated predictions for the expected behavior of the actin cable system upon changes of parameter values. We found that the model generates stable steady states with realistic values of rate constants and actin and For3p concentrations. Comparison of our results to previous experiments monitoring the FRAP of For3p-3GFP and the response of actin cables to treatments with actin depolymerizing drugs provided further support for the model. We identified the set of parameter values that produces results in agreement with experimental observations. We discuss future experiments that will help test the model's predictions and eliminate other possible mechanisms. The results of the model suggest that flow of actin cables may establish actin and For3p concentration gradients in the cytoplasm that could be important in global cell patterning

Free exopolysaccharide from Mycoplasma mycoides subsp. mycoides possesses anti-inflammatory properties

In this study we explored the immunomodulatory properties of highly purified free galactan, the soluble exopolysaccharide secreted by Mycoplasma mycoides subsp. mycoides (Mmm). Galactan was shown to bind to TLR2 but not TLR4 using HEK293 reporter cells and to induce the production of the anti-inflammatory cytokine IL-10 in bovine macrophages, whereas low IL-12p40 and no TNF-α, both pro-inflammatory cytokines, were induced in these cells. In addition, pre-treatment of macrophages with galactan substantially reduced lipopolysaccharide (LPS)-induced production of pro-inflammatory cytokines TNF- and IL-12p40 while increasing LPS-induced secretion of immunosuppressive IL-10. Also, galactan did not activate naïve lymphocytes and induced only low production of the Th1 cytokine IFN-γ in Mmm-experienced lymphocytes. Finally, galactan triggered weak recall proliferation of CD4+ T lymphocytes from contagious bovine pleuropneumonia-infected animals despite having a positive effect on the expression of co-stimulatory molecules on macrophages. All together, these results suggest that galactan possesses anti-inflammatory properties and potentially provides Mmm with a mechanism to evade host innate and adaptive cell-mediated immune responses. (Résumé d'auteur

A Three-Way Comparison of Tuberculin Skin Testing, QuantiFERON-TB Gold and T-SPOT.TB in Children

BACKGROUND: There are limited data comparing the performance of the two commercially available interferon gamma (IFN-gamma) release assays (IGRAs) for the diagnosis of tuberculosis (TB) in children. We compared QuantiFERON-TB gold In Tube (QFT-IT), T-SPOT.TB and the tuberculin skin test (TST) in children at risk for latent TB infection or TB disease. METHODS AND FINDINGS: The results of both IGRAs were compared with diagnosis assigned by TST-based criteria and assessed in relation to TB contact history. Results from the TST and at least one assay were available for 96 of 100 children. Agreement between QFT-IT and T-SPOT.TB was high (93% agreement, kappa = 0.83). QFT-IT and T-SPOT.TB tests were positive in 8 (89%) and 9 (100%) children with suspected active TB disease. There was moderate agreement between TST and either QFT-IT (75%, kappa = 0.50) or T-SPOT.TB (75%, kappa = 0.51). Among 38 children with TST-defined latent TB infection, QFT-IT gold and T-SPOT.TB assays were positive in 47% and 39% respectively. Three TST-negative children were positive by at least one IGRA. Children with a TB contact were more likely than children without a TB contact to have a positive IGRA (QFT-IT LR 3.9; T-SPOT.TB LR 3.9) and a positive TST (LR 1.4). Multivariate linear regression analysis showed that the magnitude of both TST induration and IGRA IFN-gamma responses was significantly influenced by TB contact history, but only the TST was influenced by age. CONCLUSIONS: Although a high level of agreement between the IGRAs was observed, they are commonly discordant with the TST. The correct interpretation of a negative assay in a child with a positive skin test in clinical practice remains challenging and highlights the need for longitudinal studies to determine the negative predictive value of IGRAs

Comparative transcriptome sequencing of germline and somatic tissues of the Ascaris suum gonad

<p>Abstract</p> <p>Background</p> <p><it>Ascaris suum </it>(large roundworm of pigs) is a parasitic nematode that causes substantial losses to the meat industry. This nematode is suitable for biochemical studies because, unlike <it>C. elegans</it>, homogeneous tissue samples can be obtained by dissection. It has large sperm, produced in great numbers that permit biochemical studies of sperm motility. Widespread study of <it>A. suum </it>would be facilitated by more comprehensive genome resources and, to this end, we have produced a gonad transcriptome of <it>A. suum</it>.</p> <p>Results</p> <p>Two 454 pyrosequencing runs generated 572,982 and 588,651 reads for germline (TES) and somatic (VAS) tissues of the <it>A. suum </it>gonad, respectively. 86% of the high-quality (HQ) reads were assembled into 9,955 contigs and 69,791 HQ reads remained as singletons. 2.4 million bp of unique sequences were obtained with a coverage that reached 16.1-fold. 4,877 contigs and 14,339 singletons were annotated according to the <it>C. elegans </it>protein and the Kyoto Encyclopedia of Genes and Genomes (KEGG) protein databases. Comparison of TES and VAS transcriptomes demonstrated that genes participating in DNA replication, RNA transcription and ubiquitin-proteasome pathways are expressed at significantly higher levels in TES tissues than in VAS tissues. Comparison of the <it>A. suum </it>TES transcriptome with the <it>C. elegans </it>microarray dataset identified 165 <it>A. suum </it>germline-enriched genes (83% are spermatogenesis-enriched). Many of these genes encode serine/threonine kinases and phosphatases (KPs) as well as tyrosine KPs. Immunoblot analysis further suggested a critical role of phosphorylation in both testis development and spermatogenesis. A total of 2,681 <it>A. suum </it>genes were identified to have associated RNAi phenotypes in <it>C. elegans</it>, the majority of which display embryonic lethality, slow growth, larval arrest or sterility.</p> <p>Conclusions</p> <p>Using deep sequencing technology, this study has produced a gonad transcriptome of <it>A. suum</it>. By comparison with <it>C. elegans </it>datasets, we identified sets of genes associated with spermatogenesis and gonad development in <it>A. suum</it>. The newly identified genes encoding KPs may help determine signaling pathways that operate during spermatogenesis. A large portion of <it>A. suum </it>gonadal genes have related RNAi phenotypes in <it>C. elegans </it>and, thus, might be RNAi targets for parasite control.</p

Singing for lung health in COPD: a multicentre randomised controlled trial of online delivery

Data availability statement: Data are available upon reasonable request. Individual participant data that underlie the results in the article, after de-identification (text, tables, figures and appendices) will be available on reasonable application to the corresponding author. Data will be made immediately available following publication, no end date. Data will be available to anyone who wishes to access the data, for any purpose. Data will be available indefinitely.Supplementary materials: Supplementary Data are available online at: https://bmjopenrespres.bmj.com/content/11/1/e002365.info .Background: Singing for lung health (SLH) is an arts-based breathing control and movement intervention for people with long-term respiratory conditions, intended to improve symptoms and quality of life. Online, remotely delivered programmes might improve accessibility; however, no previous studies have assessed the effectiveness of this approach. Methods: We conducted an assessor-blind randomised controlled trial comparing the impact of 12 weeks of once-weekly online SLH sessions against usual care on health-related quality of life, assessed using the RAND 36-Item Short Form Health Survey (SF-36) Mental Health Composite (MHC) and Physical Health Composite (PHC) scores. Results: We enrolled 115 people with stable chronic obstructive pulmonary disease (COPD), median (IQR) age 69 (62–74), 56.5% females, 80% prior pulmonary rehabilitation, Medical Research Council dyspnoea scale 4 (3–4), forced expiratory volume in 1 s % predicted 49 (35–63). 50 participants in each arm completed the study. The intervention arm experienced improvements in physical but not mental health components of RAND SF-36; PHC (regression coefficient (95% CI): 1.77 (95% CI 0.11 to 3.44); p=0.037), but not MHC (0.86 (95% CI −1.68 to 3.40); p=0.504). A prespecified responder analysis based on achieving a 10% improvement from baseline demonstrated a response rate for PHC of 32% in the SLH arm and 12.7% for usual care (p=0.024). A between-group difference in responder rate was not found in relation to the MHC (19.3% vs 25.9%; p=0.403). Discussion and conclusion: A 12-week online SLH programme can improve the physical component of quality of life for people with COPD, but the overall effect is relatively modest compared with the impact seen in research using face-to-face group sessions. Further work on the content, duration and dose of online interventions may be useful. Trial registration number NCT04034212.KEJP is supported was supported by the Imperial College Clinician Investigator Scholarship (no specific grant number/code). DF was supported by the Wellcome Trust [205407/Z/16/Z]

Killing by type VI secretion drives genetic phase separation and correlates with increased cooperation

By nature of their small size, dense growth and frequent need for extracellular metabolism, microbes face persistent public goods dilemmas. Genetic assortment is the only general solution stabilizing cooperation, but all known mechanisms structuring microbial populations depend on the availability of free space, an often unrealistic constraint. Here we describe a class of self-organization that operates within densely packed bacterial populations. Through mathematical modelling and experiments with Vibrio cholerae, we show how killing adjacent competitors via the Type VI secretion system (T6SS) precipitates phase separation via the ‘Model A' universality class of order-disorder transition mediated by killing. We mathematically demonstrate that T6SS-mediated killing should favour the evolution of public goods cooperation, and empirically support this prediction using a phylogenetic comparative analysis. This work illustrates the twin role played by the T6SS, dealing death to local competitors while simultaneously creating conditions potentially favouring the evolution of cooperation with kin