78 research outputs found

    Bacteriophage Infection of the Marine Bacterium Shewanella glacialimarina Induces Dynamic Changes in tRNA Modifications

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    Viruses are obligate intracellular parasites that, throughout evolution, have adapted numerous strategies to control the translation machinery, including the modulation of post-transcriptional modifications (PTMs) on transfer RNA (tRNA). PTMs are critical translation regulators used to further host immune responses as well as the expression of viral proteins. Yet, we lack critical insight into the temporal dynamics of infection-induced changes to the tRNA modification landscape (i.e., ‘modificome’). In this study, we provide the first comprehensive quantitative characterization of the tRNA modificome in the marine bacterium Shewanella glacialimarina during Shewanella phage 1/4 infection. Specifically, we show that PTMs can be grouped into distinct categories based on modification level changes at various infection stages. Furthermore, we observe a preference for the UAC codon in viral transcripts expressed at the late stage of infection, which coincides with an increase in queuosine modification. Queuosine appears exclusively on tRNAs with GUN anticodons, suggesting a correlation between phage codon usage and PTM modification. Importantly, this work provides the basis for further studies into RNA-based regulatory mechanisms employed by bacteriophages to control the prokaryotic translation machinery

    Young infants exhibit robust functional antibody responses and restrained IFN-γ production to SARS-CoV-2

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    Severe COVID-19 appears rare in children. This is unexpected, especially in young infants, who are vulnerable to severe disease caused by other respiratory viruses. We evaluate convalescent immune responses in four infants under 3 months old with confirmed COVID-19 who presented with mild febrile illness, alongside their parents, and adult controls recovered from confirmed COVID-19. Although not statistically significant, compared to seropositive adults, infants have high serum levels of IgG and IgA to SARS-CoV-2 spike protein with corresponding functional ability to block SARS-CoV-2 cellular entry. Infants also exhibit robust saliva anti-spike IgG and IgA responses. Spike-specific IFN-γ production by infant peripheral blood mononuclear cells appears restrained, but the frequency of spike-specific IFN-γ and/or TNF-ɑ producing T cells is comparable between infants and adults. On principal component analysis, infant immune responses appear distinct from their parents. Robust functional antibody responses alongside restrained IFN-γ production may help protect infants from severe COVID-19

    Development and evaluation of low-volume tests to detect and characterize antibodies to SARS-CoV-2

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    Low-volume antibody assays can be used to track SARS-CoV-2 infection rates in settings where active testing for virus is limited and remote sampling is optimal. We developed 12 ELISAs detecting total or antibody isotypes to SARS-CoV-2 nucleocapsid, spike protein or its receptor binding domain (RBD), 3 anti-RBD isotype specific luciferase immunoprecipitation system (LIPS) assays and a novel Spike-RBD bridging LIPS total-antibody assay. We utilized pre-pandemic (n=984) and confirmed/suspected recent COVID-19 sera taken pre-vaccination rollout in 2020 (n=269). Assays measuring total antibody discriminated best between pre-pandemic and COVID-19 sera and were selected for diagnostic evaluation. In the blind evaluation, two of these assays (Spike Pan ELISA and Spike-RBD Bridging LIPS assay) demonstrated >97% specificity and >92% sensitivity for samples from COVID-19 patients taken >21 days post symptom onset or PCR test. These assays offered better sensitivity for the detection of COVID-19 cases than a commercial assay which requires 100-fold larger serum volumes. This study demonstrates that low-volume in-house antibody assays can provide good diagnostic performance, and highlights the importance of using well-characterized samples and controls for all stages of assay development and evaluation. These cost-effective assays may be particularly useful for seroprevalence studies in low and middle-income countries

    SYSGENET: a meeting report from a new European network for systems genetics

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    The first scientific meeting of the newly established European SYSGENET network took place at the Helmholtz Centre for Infection Research (HZI) in Braunschweig, April 7-9, 2010. About 50 researchers working in the field of systems genetics using mouse genetic reference populations (GRP) participated in the meeting and exchanged their results, phenotyping approaches, and data analysis tools for studying systems genetics. In addition, the future of GRP resources and phenotyping in Europe was discussed

    Mitochondrial polymorphisms in rat genetic models of hypertension

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    Hypertension is a complex trait that has been studied extensively for genetic contributions of the nuclear genome. We examined mitochondrial genomes of the hypertensive strains: the Dahl Salt-Sensitive (S) rat, the Spontaneously Hypertensive Rat (SHR), and the Albino Surgery (AS) rat, and the relatively normotensive strains: the Dahl Salt-Resistant (R) rat, the Milan Normotensive Strain (MNS), and the Lewis rat (LEW). These strains were used previously for linkage analysis for blood pressure (BP) in our laboratory. The results provide evidence to suggest that variations in the mitochondrial genome do not account for observed differences in blood pressure between the S and R rats. However, variants were detected among the mitochondrial genomes of the various hypertensive strains, S, SHR, and AS, and also among the normotensive strains R, MNS, and LEW. A total of 115, 114, 106, 106, and 16 variations in mtDNA were observed between the comparisons S versus LEW, S versus MNS, S versus SHR, S versus AS, and SHR versus AS, respectively. Among the 13 genes coding for proteins of the electron transport chain, 8 genes had nonsynonymous variations between S, LEW, MNS, SHR, and AS. The lack of any sequence variants between the mitochondrial genomes of S and R rats provides conclusive evidence that divergence in blood pressure between these two inbred strains is exclusively programmed through their nuclear genomes. The variations detected among the various hypertensive strains provides the basis to construct conplastic strains and further evaluate the effects of these variants on hypertension and associated phenotypes

    Delineamentos para uma teoria da Museologia

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    The guiding principles in the formulation of a Museology theory were established\ud and disseminated internationally from the mid-1980s, and are related to the creation of the\ud International Committee for Museology (Icofom), associated with the International Council of\ud Museums (Icom). The opinions regarding the nature of so-called museological knowledge\ud were issued under the very specific conditions of each groups composition and of the intellectual\ud work undertook in the occasion. Despite the difficulties with the wording, risen in tandem with\ud the exercise (the terminology problem), we focused on the conjuncture that surrounded the\ud formulation: the environment, the aims, the way in which it was composed and the foundations\ud that characterise it, as well as some of the discussions that took place, which revealed aspects\ud that have been handed down as a legacy in this field of specialization

    The analysis of relationship among the total productivity, profitability and economic value added

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    The profitability of enterprise activities is one of the evaluation ways of management effectiveness of enterprise operations. The profitability ratios are quite well described in economics and financial literature. The current authors were less focused on the analysis of the ways of how to determine the main factors which influence the level of profitability. This problem is crucial and extraordinary important by the introduction and utilization of new production strategies. The paper defines the Total Productivity and the Total Productivity Break Even Point concept (TP_BEP). It describes the linear model of the Total Productivity Break Even Point with the developed expressions for calculation of a and b regression coefficients. The mathematical models of Total Productivity and EVA were described. Further focus of the paper was on the definition of relationships between Total Productivity an profitability (ROA). The mathematical model of this relationship was developed. The paper introduces the idea of mutual relationship of Total Productivity (PT) and Economic Value Added (EVA). The Break Even Point concept of Total Productivity was used by the development of relationship model of EVA and Total Productivity. The final solution was simplified for easy practical utilization
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