57 research outputs found
Ī±-MSH inhibits induction of C/EBPĪ²-DNA binding activity and NOS2 gene transcription in macrophages
Ī±-MSH inhibits induction of C/EBPĪ²-DNA binding activity and NOS2 gene transcription in macrophages.BackgroundĪ±-Melanocyteāstimulating hormone (Ī±-MSH) is an endogenous tridecapeptide that exerts anti-inflammatory actions and abrogates postischemic renal injury in rodents. Ī±-MSH inhibits lipopolysaccharide (LPS)-induced gene expression of several cytokines, chemokines, and nitric oxide synthase-2 (NOS2), but the molecular mechanisms underlying these effects have not been clearly defined. To test the hypothesis that Ī±-MSH inhibits the expression of inducible trans-activating factors involved in NOS2 regulation, we used RAW 264.7 macrophage cells to examine the effects of Ī±-MSH on the activation of nuclear factor-ŠŗB (NF-ŠŗB) and CCAAT/enhancer binding protein-Ī² (C/EBPĪ²), trans-acting factors known to be involved in LPS + interferon (IFN)-Ī³ induction of the NOS2 gene.MethodsGel shift assays were performed to identify NF-ŠŗB and C/EBP DNA binding activities in LPS + IFN-Ī³ātreated RAW 264.7 cells in the presence and absence of Ī±-MSH. NOS2 promoter assays were conducted to identify the effects of Ī±-MSH on LPS + IFN-Ī³āmediated induction of NOS2 transcription.ResultsGel shift assays demonstrated LPS + IFN-Ī³ induction of NF-ŠŗB and C/EBP family protein-DNA complexes in nuclei harvested from the cells. Supershift assays revealed that the C/EBP complexes were comprised of C/EBPĪ², but not C/EBPĪ±, C/EBPĪ±, or C/EBPĻµ. Ī±-MSH (100 nmol/L) inhibited the LPS + IFN-Ī³āmediated induction of nuclear DNA binding activity of C/EBPĪ², but not that of NF-ŠŗB (in contrast to reports in other cell types), as well as the activity of a murine NOS2 promoter-luciferase construct. In contrast, Ī±-MSH (100 nmol/L) had no effect on the induction of NOS2 promoter-luciferase genes harboring deletion or mutation of the C/EBP box.ConclusionsThese data indicate that Ī±-MSH inhibits the induction of C/EBPĪ² DNA binding activity and that this effect is a major mechanism by which Ī±-MSH inhibits the transcription of the NOS2 gene. The inability of Ī±-MSH to inhibit LPS + IFN-Ī³ induction of NF-ŠŗB in murine macrophage cells, which contrasts with inhibitory effects of the neuropeptide in other cell types, suggests that cell-typeāspecific mechanisms are involved
Magdalenian and Epimagdalenian chronology and palaeoenvironments at KÅÆlna Cave, Moravia, Czech Republic
KÅÆlna Cave is the only site in Moravia, Czech Republic, from which large assemblages of both Magdalenian and Epimagdalenian archaeological materials have been excavated from relatively secure stratified deposits. The site therefore offers the unrivalled opportunity to explore the relationship between these two archaeological phases. In this study, we undertake radiocarbon, stable isotope (carbon, nitrogen and sulphur), and ZooMS analysis of the archaeological faunal assemblage to explore the chronological and environmental context of the Magdalenian and Epimagdalenian deposits. Our results show that the Magdalenian and Epimagdalenian deposits can be understood as discrete units from one another, dating to the Late Glacial between c. 15,630 cal. BP and 14,610 cal. BP, and c. 14,140 cal. BP and 12,680 cal. BP, respectively. Stable isotope results (Ī“13C, Ī“15N, Ī“34S) indicate that Magdalenian and Epimagdalenian activity at KÅÆlna Cave occurred in very different environmental settings. Magdalenian occupation took place within a nutrient-poor landscape that was experiencing rapid changes to environmental moisture, potentially linked to permafrost thaw. In contrast, Epimagdalenian occupation occurred in a relatively stable, temperate environment composed of a mosaic of woodland and grassland habitats. The potential chronological gap between the two phases, and their associations with very different environmental conditions, calls into question whether the Epimagdalenian should be seen as a local, gradual development of the Magdalenian. It also raises the question of whether the gap in occupation at KÅÆlna Cave could represent a change in settlement dynamics and/or behavioural adaptations to changing environmental conditions
Equation-Free Analysis of Two-Component System Signalling Model Reveals the Emergence of Co-Existing Phenotypes in the Absence of Multistationarity
Phenotypic differences of genetically identical cells under the same environmental conditions have been attributed to the inherent stochasticity of biochemical processes. Various mechanisms have been suggested, including the existence of alternative steady states in regulatory networks that are reached by means of stochastic fluctuations, long transient excursions from a stable state to an unstable excited state, and the switching on and off of a reaction network according to the availability of a constituent chemical species. Here we analyse a detailed stochastic kinetic model of two-component system signalling in bacteria, and show that alternative phenotypes emerge in the absence of these features. We perform a bifurcation analysis of deterministic reaction rate equations derived from the model, and find that they cannot reproduce the whole range of qualitative responses to external signals demonstrated by direct stochastic simulations. In particular, the mixed mode, where stochastic switching and a graded response are seen simultaneously, is absent. However, probabilistic and equation-free analyses of the stochastic model that calculate stationary states for the mean of an ensemble of stochastic trajectories reveal that slow transcription of either response regulator or histidine kinase leads to the coexistence of an approximate basal solution and a graded response that combine to produce the mixed mode, thus establishing its essential stochastic nature. The same techniques also show that stochasticity results in the observation of an all-or-none bistable response over a much wider range of external signals than would be expected on deterministic grounds. Thus we demonstrate the application of numerical equation-free methods to a detailed biochemical reaction network model, and show that it can provide new insight into the role of stochasticity in the emergence of phenotypic diversity
The predictive role of symptoms in COVID-19 diagnostic models : A longitudinal insight
Acknowledgements 2019nCoV-302 Study Group Members: The NVX-CoV2373-2019nCoV-302 clinical trial was a collective group effort across multiple institutions and locations. Below is a list of sites and staff that significantly contributed to the implementation and conduct of the NVX-CoV2373-2019nCoV-302 clinical trial.Peer reviewe
Safety and efficacy of the NVX-CoV2373 coronavirus disease 2019 vaccine at completion of the placebo-controlled phase of a randomized controlled trial
Background:Ā The recombinant protein-based vaccine, NVX-CoV2373, demonstrated 89.7% efficacy against coronavirus disease 2019 (COVID-19) in a phase 3, randomized, observer-blinded, placebo-controlled trial in the United Kingdom. The protocol was amended to include a blinded crossover. Data to the end of the placebo-controlled phase are reported.
Methods:Ā Adults aged 18ā84 years received 2 doses of NVX-CoV2373 or placebo (1:1) and were monitored for virologically confirmed mild, moderate, or severe COVID-19 (onset from 7 days after second vaccination). Participants who developed immunoglobulin G (IgG) against nucleocapsid protein but did not show symptomatic COVID-19 were considered asymptomatic. Secondary outcomes included anti-spike (S) IgG responses, wild-type virus neutralization, and T-cell responses.
Results:Ā Of 15 185 participants, 13 989 remained in the per-protocol efficacy population (6989 NVX-CoV2373, 7000 placebo). At a maximum of 7.5 months (median, 4.5) postvaccination, there were 24 cases of COVID-19 among NVX-CoV2373 recipients and 134 cases among placebo recipients, a vaccine efficacy of 82.7% (95% confidence interval [CI], 73.3%ā88.8%). Vaccine efficacy was 100% (95% CI, 17.9%ā100.0%) against severe disease and 76.3% (95% CI, 57.4%ā86.8%) against asymptomatic disease. High anti-S and neutralization responses to vaccination were evident, together with S-proteināspecific induction of interferon-Ī³ secretion in peripheral blood T cells. Incidence of serious adverse events and adverse events of special interest were similar between groups.
Conclusions:Ā A 2-dose regimen of NVX-CoV2373 conferred a high level of ongoing protection against asymptomatic, symptomatic, and severe COVID-19 through >6 months postvaccination. A gradual decrease of protection suggests that a booster may be indicated.
Clinical Trials Registration:Ā EudraCT, 2020-004123-16
Safety and Efficacy of the NVX-CoV2373 Coronavirus Disease 2019 Vaccine at Completion of the Placebo-Controlled Phase of a Randomized Controlled Trial
Acknowledgements The study and article were funded by Novavax. We would like to thank all the study participants for their commitment to this study. We also acknowledge the investigators and their study teams for their hard work and dedication. In addition, we would like to thank the National Institute for Health Research, representatives from the Department of Health and Social Care laboratories and NHS Digital and the members of the UK Vaccine Task Force. Editorial support was provided by Kelly Cameron of Ashfield MedComms, an Inizio company Funding This work was funded by Novavax, and the sponsor had primary responsibility for study design, study vaccines, protocol development, study monitoring, data management, and statistical analyses. All authors reviewed and approved the manuscript before submission. LF reports a position as a prior full-time employee, now contractor to Novavax re-imbursed hourly for work performed on this study and in analyses and drafting this report. IC reports providing medical writing support for this work as an employee of NovavaxPeer reviewedPublisher PD
Dual ancestries and ecologies of the Late Glacial Palaeolithic in Britain
Genetic investigations of Upper Palaeolithic Europe have revealed a complex and transformative history of human population movements and ancestries, with evidence of several instances of genetic change across the European continent in the period following the Last Glacial Maximum (LGM). Concurrent with these genetic shifts, the post-LGM period is characterized by a series of significant climatic changes, population expansions and cultural diversification. Britain lies at the extreme northwest corner of post-LGM expansion and its earliest Late Glacial human occupation remains unclear. Here we present genetic data from Palaeolithic human individuals in the United Kingdom and the oldest human DNA thus far obtained from Britain or Ireland. We determine that a Late Upper Palaeolithic individual from Gough's Cave probably traced all its ancestry to Magdalenian-associated individuals closely related to those from sites such as El MirĆ³n Cave, Spain, and TroisiĆØme Caverne in Goyet, Belgium. However, an individual from Kendrick's Cave shows no evidence of having ancestry related to the Goughās Cave individual. Instead, the Kendrickās Cave individual traces its ancestry to groups who expanded across Europe during the Late Glacial and are represented at sites such as Villabruna, Italy. Furthermore, the individuals differ not only in their genetic ancestry profiles but also in their mortuary practices and their diets and ecologies, as evidenced through stable isotope analyses. This finding mirrors patterns of dual genetic ancestry and admixture previously detected in Iberia but may suggest a more drastic genetic turnover in northwestern Europe than in the southwest
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