20 research outputs found

    Age-Dependent Maturation of Toll-Like Receptor-Mediated Cytokine Responses in Gambian Infants

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    The global burden of neonatal and infant mortality due to infection is staggering, particularly in resource-poor settings. Early childhood vaccination is one of the major interventions that can reduce this burden, but there are specific limitations to inducing effective immunity in early life, including impaired neonatal leukocyte production of Th1-polarizing cytokines to many stimuli. Characterizing the ontogeny of Toll-like receptor (TLR)-mediated innate immune responses in infants may shed light on susceptibility to infection in this vulnerable age group, and provide insights into TLR agonists as candidate adjuvants for improved neonatal vaccines. As little is known about the leukocyte responses of infants in resource-poor settings, we characterized production of Th1-, Th2-, and anti-inflammatory- cytokines in response to agonists of TLRs 1-9 in whole blood from 120 Gambian infants ranging from newborns (cord blood) to 12 months of age. Most of the TLR agonists induced TNFα, IL-1β, IL-6, and IL-10 in cord blood. The greatest TNFα responses were observed for TLR4, -5, and -8 agonists, the highest being the thiazoloquinoline CLO75 (TLR7/8) that also uniquely induced cord blood IFNγ production. For most agonists, TLR-mediated TNFα and IFNγ responses increased from birth to 1 month of age. TLR8 agonists also induced the greatest production of the Th1-polarizing cytokines TNFα and IFNγ throughout the first year of life, although the relative responses to the single TLR8 agonist and the combined TLR7/8 agonist changed with age. In contrast, IL-1β, IL-6, and IL-10 responses to most agonists were robust at birth and remained stable through 12 months of age. These observations provide fresh insights into the ontogeny of innate immunity in African children, and may inform development of age-specific adjuvanted vaccine formulations important for global health

    Clinical Sequencing Exploratory Research Consortium: Accelerating Evidence-Based Practice of Genomic Medicine

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    Despite rapid technical progress and demonstrable effectiveness for some types of diagnosis and therapy, much remains to be learned about clinical genome and exome sequencing (CGES) and its role within the practice of medicine. The Clinical Sequencing Exploratory Research (CSER) consortium includes 18 extramural research projects, one National Human Genome Research Institute (NHGRI) intramural project, and a coordinating center funded by the NHGRI and National Cancer Institute. The consortium is exploring analytic and clinical validity and utility, as well as the ethical, legal, and social implications of sequencing via multidisciplinary approaches; it has thus far recruited 5,577 participants across a spectrum of symptomatic and healthy children and adults by utilizing both germline and cancer sequencing. The CSER consortium is analyzing data and creating publically available procedures and tools related to participant preferences and consent, variant classification, disclosure and management of primary and secondary findings, health outcomes, and integration with electronic health records. Future research directions will refine measures of clinical utility of CGES in both germline and somatic testing, evaluate the use of CGES for screening in healthy individuals, explore the penetrance of pathogenic variants through extensive phenotyping, reduce discordances in public databases of genes and variants, examine social and ethnic disparities in the provision of genomics services, explore regulatory issues, and estimate the value and downstream costs of sequencing. The CSER consortium has established a shared community of research sites by using diverse approaches to pursue the evidence-based development of best practices in genomic medicine

    Genetic mechanisms of critical illness in COVID-19.

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    Host-mediated lung inflammation is present1, and drives mortality2, in the critical illness caused by coronavirus disease 2019 (COVID-19). Host genetic variants associated with critical illness may identify mechanistic targets for therapeutic development3. Here we report the results of the GenOMICC (Genetics Of Mortality In Critical Care) genome-wide association study in 2,244 critically ill patients with COVID-19 from 208 UK intensive care units. We have identified and replicated the following new genome-wide significant associations: on chromosome 12q24.13 (rs10735079, P = 1.65 × 10-8) in a gene cluster that encodes antiviral restriction enzyme activators (OAS1, OAS2 and OAS3); on chromosome 19p13.2 (rs74956615, P = 2.3 × 10-8) near the gene that encodes tyrosine kinase 2 (TYK2); on chromosome 19p13.3 (rs2109069, P = 3.98 ×  10-12) within the gene that encodes dipeptidyl peptidase 9 (DPP9); and on chromosome 21q22.1 (rs2236757, P = 4.99 × 10-8) in the interferon receptor gene IFNAR2. We identified potential targets for repurposing of licensed medications: using Mendelian randomization, we found evidence that low expression of IFNAR2, or high expression of TYK2, are associated with life-threatening disease; and transcriptome-wide association in lung tissue revealed that high expression of the monocyte-macrophage chemotactic receptor CCR2 is associated with severe COVID-19. Our results identify robust genetic signals relating to key host antiviral defence mechanisms and mediators of inflammatory organ damage in COVID-19. Both mechanisms may be amenable to targeted treatment with existing drugs. However, large-scale randomized clinical trials will be essential before any change to clinical practice

    Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

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    Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

    Dimethyl fumarate in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

    Get PDF
    Dimethyl fumarate (DMF) inhibits inflammasome-mediated inflammation and has been proposed as a treatment for patients hospitalised with COVID-19. This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing multiple treatments in patients hospitalised for COVID-19 (NCT04381936, ISRCTN50189673). In this assessment of DMF performed at 27 UK hospitals, adults were randomly allocated (1:1) to either usual standard of care alone or usual standard of care plus DMF. The primary outcome was clinical status on day 5 measured on a seven-point ordinal scale. Secondary outcomes were time to sustained improvement in clinical status, time to discharge, day 5 peripheral blood oxygenation, day 5 C-reactive protein, and improvement in day 10 clinical status. Between 2 March 2021 and 18 November 2021, 713 patients were enroled in the DMF evaluation, of whom 356 were randomly allocated to receive usual care plus DMF, and 357 to usual care alone. 95% of patients received corticosteroids as part of routine care. There was no evidence of a beneficial effect of DMF on clinical status at day 5 (common odds ratio of unfavourable outcome 1.12; 95% CI 0.86-1.47; p = 0.40). There was no significant effect of DMF on any secondary outcome

    Highly Luminescent Dinuclear Platinum(II) Complexes Incorporating Bis-Cyclometallating Pyrazine-Based Ligands: A Versatile Approach to Efficient Red Phosphors

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    A series of luminescent dinuclear platinum(II) complexes incorporating diphenylpyrazine-based bridging ligands ((LH2)-H-n) has been prepared. Both 2,5-diphenylpyrazine ((LH2)-H-2) and 2,3-diphenylpyrazine ((LH2)-H-3) are able to undergo cyclometalation of the two phenyl rings, with each metal ion binding to the two nitrogen atoms of the central heterocycle, giving, after treatment with the anion of dipivaloyl methane (dpm), complexes of formula \{Pt(dpm)\}(2)L-n. These compounds are isomers of the analogous complex of 4,6-diphenylpyrimidine ((LH2)-H-1). Related complexes of dibenzo-(f,h)quinoxaline ((LH2)-H-4), 2,3-diphenyl-quinoxaline ((LH2)-H-5), and dibenzo{[}3,2-a:2',3'-c]phenazine ((LH2)-H-6) have also been prepared, allowing the effects of strapping together the phenyl rings ((LH2)-H-4 and (LH2)-H-6) and/or extension of the conjugation from pyrazine to quinoxaline ((LH2)-H-5 and (LH2)-H-6) to be investigated. In all cases, the corresponding mononuclear complexes, Pt(dpm)(LH)-H-n, have been isolated too. All 12 complexes are phosphorescent in solution at ambient temperature. Emission spectra of the dinuclear complexes are consistently red shifted compared to their mononuclear analogues, as are the lowest energy absorption bands. Electrochemical data and TD-DFT calculations suggest that this effect arises primarily from stabilization of the LUMO. Introduction of the second metal ion also has the effect of substantially increasing the molar absorptivity and, in most cases, the radiative rate constants. Meanwhile, extension of conjugation in the heterocycle of (LH2)-H-5 and (LH2)-H-6 and planarization of the aromatic system favored by interannular bond formation in (LH2)-H-4 and (LH2)-H-6 leads to further red shifts of the absorption and emission spectra to wavelengths that are unusually long for cyclometalated platinum(II) complexes. The results may offer a versatile design strategy for tuning and optimizing the optical properties of d-block metal complexes for contemporary applications

    Highly Luminescent Dinuclear Platinum(II) Complexes Incorporating Bis-Cyclometallating Pyrazine-Based Ligands: A Versatile Approach to Efficient Red Phosphors

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    A series of luminescent dinuclear platinum­(II) complexes incorporating diphenylpyrazine-based bridging ligands (L<sup><i>n</i></sup>H<sub>2</sub>) has been prepared. Both 2,5-diphenylpyrazine (L<sup>2</sup>H<sub>2</sub>) and 2,3-diphenylpyrazine (L<sup>3</sup>H<sub>2</sub>) are able to undergo cyclometalation of the two phenyl rings, with each metal ion binding to the two nitrogen atoms of the central heterocycle, giving, after treatment with the anion of dipivaloyl methane (dpm), complexes of formula {Pt­(dpm)}<sub>2</sub>L<sup><i>n</i></sup>. These compounds are isomers of the analogous complex of 4,6-diphenylpyrimidine (L<sup>1</sup>H<sub>2</sub>). Related complexes of dibenzo­(f,h)­quinoxaline (L<sup>4</sup>H<sub>2</sub>), 2,3-diphenyl-quinoxaline (L<sup>5</sup>H<sub>2</sub>), and dibenzo­[3,2-a:2′,3′-c]­phenazine (L<sup>6</sup>H<sub>2</sub>) have also been prepared, allowing the effects of strapping together the phenyl rings (L<sup>4</sup>H<sub>2</sub> and L<sup>6</sup>H<sub>2</sub>) and/or extension of the conjugation from pyrazine to quinoxaline (L<sup>5</sup>H<sub>2</sub> and L<sup>6</sup>H<sub>2</sub>) to be investigated. In all cases, the corresponding mononuclear complexes, Pt­(dpm)­L<sup><i>n</i></sup>H, have been isolated too. All 12 complexes are phosphorescent in solution at ambient temperature. Emission spectra of the dinuclear complexes are consistently red shifted compared to their mononuclear analogues, as are the lowest energy absorption bands. Electrochemical data and TD-DFT calculations suggest that this effect arises primarily from stabilization of the LUMO. Introduction of the second metal ion also has the effect of substantially increasing the molar absorptivity and, in most cases, the radiative rate constants. Meanwhile, extension of conjugation in the heterocycle of L<sup>5</sup>H<sub>2</sub> and L<sup>6</sup>H<sub>2</sub> and planarization of the aromatic system favored by interannular bond formation in L<sup>4</sup>H<sub>2</sub> and L<sup>6</sup>H<sub>2</sub> leads to further red shifts of the absorption and emission spectra to wavelengths that are unusually long for cyclometalated platinum­(II) complexes. The results may offer a versatile design strategy for tuning and optimizing the optical properties of d-block metal complexes for contemporary applications
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