45 research outputs found

    A snapshot of translation in Mycobacterium tuberculosis during exponential growth and nutrient starvation revealed by ribosome profiling

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    Mycobacterium tuberculosis, which causes tuberculosis, can undergo prolonged periods of non-replicating persistence in the host. The mechanisms underlying this are not fully understood, but translational regulation is thought to play a role. A large proportion of mRNA transcripts expressed in M. tuberculosis lack canonical bacterial translation initiation signals, but little is known about the implications of this for fine-tuning of translation. Here, we perform ribosome profiling to characterize the translational landscape of M. tuberculosis under conditions of exponential growth and nutrient starvation. Our data reveal robust, widespread translation of non-canonical transcripts and point toward different translation initiation mechanisms compared to canonical Shine-Dalgarno transcripts. During nutrient starvation, patterns of ribosome recruitment vary, suggesting that regulation of translation in this pathogen is more complex than originally thought. Our data represent a rich resource for others seeking to understand translational regulation in bacterial pathogens

    Functional mechanisms underlying pleiotropic risk alleles at the 19p13.1 breast-ovarian cancer susceptibility locus

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    A locus at 19p13 is associated with breast cancer (BC) and ovarian cancer (OC) risk. Here we analyse 438 SNPs in this region in 46,451 BC and 15,438 OC cases, 15,252 BRCA1 mutation carriers and 73,444 controls and identify 13 candidate causal SNPs associated with serous OC (P=9.2 × 10-20), ER-negative BC (P=1.1 × 10-13), BRCA1-associated BC (P=7.7 × 10-16) and triple negative BC (P-diff=2 × 10-5). Genotype-gene expression associations are identified for candidate target genes ANKLE1 (P=2 × 10-3) and ABHD8 (P<2 × 10-3). Chromosome conformation capture identifies interactions between four candidate SNPs and ABHD8, and luciferase assays indicate six risk alleles increased transactivation of the ADHD8 promoter. Targeted deletion of a region containing risk SNP rs56069439 in a putative enhancer induces ANKLE1 downregulation; and mRNA stability assays indicate functional effects for an ANKLE1 3′-UTR SNP. Altogether, these data suggest that multiple SNPs at 19p13 regulate ABHD8 and perhaps ANKLE1 expression, and indicate common mechanisms underlying breast and ovarian cancer risk

    Altered TMPRSS2 usage by SARS-CoV-2 Omicron impacts infectivity and fusogenicity

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    The SARS-CoV-2 Omicron BA.1 variant emerged in 20211 and has multiple mutations in its spike protein2. Here we show that the spike protein of Omicron has a higher affinity for ACE2 compared with Delta, and a marked change in its antigenicity increases Omicron’s evasion of therapeutic monoclonal and vaccine-elicited polyclonal neutralizing antibodies after two doses. mRNA vaccination as a third vaccine dose rescues and broadens neutralization. Importantly, the antiviral drugs remdesivir and molnupiravir retain efficacy against Omicron BA.1. Replication was similar for Omicron and Delta virus isolates in human nasal epithelial cultures. However, in lung cells and gut cells, Omicron demonstrated lower replication. Omicron spike protein was less efficiently cleaved compared with Delta. The differences in replication were mapped to the entry efficiency of the virus on the basis of spike-pseudotyped virus assays. The defect in entry of Omicron pseudotyped virus to specific cell types effectively correlated with higher cellular RNA expression of TMPRSS2, and deletion of TMPRSS2 affected Delta entry to a greater extent than Omicron. Furthermore, drug inhibitors targeting specific entry pathways3 demonstrated that the Omicron spike inefficiently uses the cellular protease TMPRSS2, which promotes cell entry through plasma membrane fusion, with greater dependency on cell entry through the endocytic pathway. Consistent with suboptimal S1/S2 cleavage and inability to use TMPRSS2, syncytium formation by the Omicron spike was substantially impaired compared with the Delta spike. The less efficient spike cleavage of Omicron at S1/S2 is associated with a shift in cellular tropism away from TMPRSS2-expressing cells, with implications for altered pathogenesis

    Status incongruity and backlash effects: Defending the gender hierarchy motivates prejudice against female leaders

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    Agentic female leaders risk social and economic penalties for behaving counter-stereotypically (i.e., backlash; Rudman, 1998), but what motivates prejudice against female leaders? The status incongruity hypothesis (SIH) proposes that agentic women are penalized for status violations because doing so defends the gender hierarchy. Consistent with this view, Study 1 found that women are proscribed from dominant, high status displays (which are reserved for leaders and men); Studies 2-3 revealed that prejudice against agentic female leaders was mediated by a dominance penalty; and in Study 3, participants' gender system-justifying beliefs moderated backlash effects. Study 4 found that backlash was exacerbated when perceivers were primed with a system threat. Study 5 showed that only female leaders who threatened the status quo suffered sabotage. In concert, support for the SIH suggests that backlash functions to preserve male dominance by reinforcing a double standard for power and control

    "Debriefing-on-demand": A pilot Assessment of using a "pause button" in medical simulation

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    Simulation is an effective tool in medical education with debriefing as the cardinal educational component. Alternate debriefing strategies might further enhance the educational value of simulation. Here, we pilot a novel strategy that allows trainees to initiate debriefing at any point during the scenario, when they consider it necessary.With ethics approval, 8 postgraduate year 1 anesthesia residents (with no previous exposure to high-fidelity simulation) were randomly assigned to lead 2 of 8 scenarios with 2 debriefing strategies. With "debriefing-on-demand," residents had the option to initiate debriefing at any point in the scenario by activation of a "pause button"-in addition to undergoing conventional debriefing at the end of the scenario. Those randomized to "conventional debriefing" were debriefed only at the end of the scenario. All were allocated as team leader with both debriefing strategies and as a participant in remaining scenarios. Residents provided feedback regarding each method using Likert scales and completion of open-ended statements.Debriefing-on-demand was easily integrated into all scenarios, and most learners (88%) supported its use in future simulation sessions. The following 4 themes emerged from qualitative analyses: (1) improvements in the clarification and integration of knowledge, (2) reductions in stress/anxiety, (3) facilitated reflection on action, and (4) maintained realism comparable with conventional debriefing.Debriefing-on-demand was easily integrated into all scenarios and well received by these trainees new to simulation. Larger trials that use validated tools are needed to determine the absolute impact of debriefing-on-demand on stress levels and the overall learning value of simulation for trainees at different levels of training.Michael McMullen, Rosemary Wilson, Melinda Fleming, David Mark, Devin Sydor, Louie Wang, Jorge Zamora, Rachel Phelan, Jessica E. Burjorje

    Public Duty and Private Prejudice: Sexualities, Equalities and Local Government

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    Rather than critiquing social institutions and practices that have historically excluded lesbians and gay men, as did earlier social movements in the 1960s and 1970s, since the 1990s the politics of sexuality has increasingly been about demanding equal rights of citizenship. These citizenship demands have, at least to a degree, been answered via a raft of recent legislation in the UK including the Adoption and Children Act 2002, Employment Equality (Sexual Orientation) Regulations 2003, Gender Recognition Act 2004 and the Civil Partnership Act 2004, and by associated changes in policy making and practice that emphasize ‘Equality and Diversity’. In this article we consider how the implementation of sexualities equalities policies is related to processes of privatization and individualization. This is illustrated by using sexualities equalities work in local government as a case study to indicate how processes of change and resistance are aided by these processes. The article draws on findings from a study of lesbian, gay, bisexual and transgender (LGBT) equalities initiatives in local government in England, Wales and Northern Ireland, which examined the views of those who now have a public duty to implement recent legislative and policy shifts and are obliged to develop equalities initiatives concerning ‘sexual orientation' and ‘gender reassignment’

    Perfusion assessment in laparoscopic left-sided/anterior resection (PILLAR II): A multi-institutional study

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    BACKGROUND: Our primary objective was to demonstrate the utility and feasibility of the intraoperative assessment of colon and rectal perfusion using fluorescence angiography (FA) during left-sided colectomy and anterior resection. Anastomotic leak (AL) after colorectal resection increases morbidity, mortality, and, in cancer cases, recurrence rates. Inadequate perfusion may contribute to AL. The PINPOINT Endoscopic Fluorescence Imaging System allows for intraoperative assessment of anastomotic perfusion
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