22 research outputs found

    Functional Evolution of Leptin of Ochotona curzoniae in Adaptive Thermogenesis Driven by Cold Environmental Stress

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    BACKGROUND: Environmental stress can accelerate the directional selection and evolutionary rate of specific stress-response proteins to bring about new or altered functions, enhancing an organism's fitness to challenging environments. Plateau pika (Ochotona curzoniae), an endemic and keystone species on Qinghai-Tibetan Plateau, is a high hypoxia and low temperature tolerant mammal with high resting metabolic rate and non-shivering thermogenesis to cope in this harsh plateau environment. Leptin is a key hormone related to how these animals regulate energy homeostasis. Previous molecular evolutionary analysis helped to generate the hypothesis that adaptive evolution of plateau pika leptin may be driven by cold stress. METHODOLOGY/PRINCIPAL FINDINGS: To test the hypothesis, recombinant pika leptin was first purified. The thermogenic characteristics of C57BL/6J mice injected with pika leptin under warm (23±1°C) and cold (5±1°C) acclimation is investigated. Expression levels of genes regulating adaptive thermogenesis in brown adipose tissue and the hypothalamus are compared between pika leptin and human leptin treatment, suggesting that pika leptin has adaptively and functionally evolved. Our results show that pika leptin regulates energy homeostasis via reduced food intake and increased energy expenditure under both warm and cold conditions. Compared with human leptin, pika leptin demonstrates a superior induced capacity for adaptive thermogenesis, which is reflected in a more enhanced β-oxidation, mitochondrial biogenesis and heat production. Moreover, leptin treatment combined with cold stimulation has a significant synergistic effect on adaptive thermogenesis, more so than is observed with a single cold exposure or single leptin treatment. CONCLUSIONS/SIGNIFICANCE: These findings support the hypothesis that cold stress has driven the functional evolution of plateau pika leptin as an ecological adaptation to the Qinghai-Tibetan Plateau

    Prioritizing multiple therapeutic targets in parallel using automated DNA-encoded library screening

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    AbstractThe identification and prioritization of chemically tractable therapeutic targets is a significant challenge in the discovery of new medicines. We have developed a novel method that rapidly screens multiple proteins in parallel using DNA-encoded library technology (ELT). Initial efforts were focused on the efficient discovery of antibacterial leads against 119 targets from Acinetobacter baumannii and Staphylococcus aureus. The success of this effort led to the hypothesis that the relative number of ELT binders alone could be used to assess the ligandability of large sets of proteins. This concept was further explored by screening 42 targets from Mycobacterium tuberculosis. Active chemical series for six targets from our initial effort as well as three chemotypes for DHFR from M. tuberculosis are reported. The findings demonstrate that parallel ELT selections can be used to assess ligandability and highlight opportunities for successful lead and tool discovery.</jats:p

    Selective neuromodulation and mutual inhibition within the CA3-CA2 system can prioritize sequences for replay

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    To make optimal use of previous experiences, important neural activity sequences must be prioritized during hippocampal replay. Integrating insights about the interplay between CA3 and CA2, we propose a conceptual framework that allows the two regions to control which sequences are reactivated. We suggest that neuromodulatory‐gated plasticity and mutual inhibition enable discrete assembly sequences in both regions to support each other while suppressing competing sequences. This perspective provides a coherent interpretation for a variety of seemingly disconnected functional properties of CA2 and paves the way for a more general understanding of CA2

    Selective neuromodulation and mutual inhibition within the CA3-CA2 system can prioritize sequences for replay

    No full text
    To make optimal use of previous experiences, important neural activity sequences must be prioritized during hippocampal replay. Integrating insights about the interplay between CA3 and CA2, we propose a conceptual framework that allows the two regions to control which sequences are reactivated. We show that neuromodulatory-gated plasticity and mutual inhibition enable discrete assembly sequences in both regions to support each other while suppressing competing sequences. This perspective provides a coherent interpretation for a variety of seemingly disconnected functional properties of CA2 and paves the way for a more general understanding of CA2

    Impact of Time to Intervention on Catheter-Directed Therapy for Pulmonary Embolism

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    OBJECTIVES:. Cather-directed therapies (CDTs) are an evolving therapeutic option for patients with intermediate-risk pulmonary embolism (PE). Although many techniques have been studied, there is limited evidence for the impact of timing of intervention on patient outcomes. Our objective was to assess the association between time to CDT in patients presenting with PE on patient-related outcomes such as length of stay (LOS) and mortality. DESIGN:. Retrospective cohort study. SETTING:. Single academic center. PATIENTS:. We identified patients for which the PE response team had been activated from January 2014 to October 2021. Patients were split into two cohorts depending on whether they went to CDT less than 24 hours from admission (early) versus greater than 24 hours (late). INTERVENTIONS:. None. MEASUREMENTS AND MAIN RESULTS:. Data on demographics, timing of interventions, pulmonary hemodynamics, and outcomes were collected. Sixty-four patients were included in analysis. Thirty-nine (63.8%) underwent their procedure less than 24 hours from admission, whereas 25 (36.2%) underwent the procedure after 24 hours. The time from admission to CDT was 15.9 hours (9.1–20.3 hr) in the early group versus 33.4 (27.9–41) in the late group (p ≤ 0.001). There was a greater decrease in pulmonary artery systolic pressure after intervention in the early cohort (14 mm Hg [6–20 mm Hg] vs 6 mm Hg [1–10 mm Hg]; p = 0.022). Patients who received earlier intervention were found to have shorter hospital LOS (4 vs 7 d; p = 0.038) and ICU LOS (3 vs 5 d; p = 0.004). There was no difference in inhospital mortality between the groups (17.9% vs 12%; p = 0.523). CONCLUSIONS:. Patients who underwent CDT within 24 hours of admission were more likely to have shorter hospital and ICU LOS. The magnitude of change in LOS between the two cohorts was not fully explained by the difference in time to CDT. There were modest improvements in pulmonary hemodynamics in the patients who underwent CDT earlier

    Work-related psychological health among clergy serving in the Presbyterian Church (USA) : testing the idea of balanced affect

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    Drawing on the classic model of balanced affect, the Francis Burnout Inventory (FBI) conceptualises good work-related psychological health among clergy in terms of negative affect being balanced by positive affect. In a random sample of 744 clergy (539 clergymen and 205 clergywomen) serving in The Presbyterian Church (USA), negative affect was assessed by the Scale of Emotional Exhaustion in Ministry (SEEM) and positive affect was assessed by the Satisfaction in Ministry Scale (SIMS). At the same time, burnout was independently assessed using self-report measures of overall health and burnout, and by the extraversion and neuroticism scales of Eysenck’s dimensional model of personality. These independent measures of burnout indicated higher burnout among those who were emotionally exhausted and lower burnout among those who had high levels of satisfaction with their ministry. Crucially for proving the idea of balanced affect, there was a significant interaction between the effects of SEEM and SIMS scores on these independent measures of burnout, showing that the mitigating effects of positive affect on burnout increased with increasing levels of negative affect

    Inhaled pulmonary vasodilators are not associated with improved gas exchange in mechanically ventilated patients with COVID-19: A retrospective cohort study

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    Purpose: Measure the effect of inhaled pulmonary vasodilators on gas exchange in mechanically ventilated patients with COVID-19. Methods: A retrospective observational cohort study at three New York University Hospitals was performed including eighty-four mechanically ventilated SARS Cov-2 nasopharyngeal PCR positive patients, sixty nine treated with inhaled nitric oxide (iNO) and fifteen with inhaled epoprostenol (iEPO). The primary outcomes were change in PAO2:FIO2 ratio, oxygenation Index (OI), and ventilatory ratio (VR) after initiation of inhaled pulmonary vasodilators. Results: There was no significant change in PAO2:FIO2ratio after initiation of iNO (mean − 4.1, 95% CI -17.3-9.0, P = 0.54) or iEPO (mean − 3.4, 95% CI -19.7-12.9, P = 0.66), in OI after initiation of iNO (mean 2.1, 95% CI-0.04-4.2, P = 0.054) or iEPO (mean − 3.4, 95% CI -19.7-12.9, P = 0.75), or in VR after initiation of iNO (mean 0.17, 95% CI -0.03-0.36, P = 0.25) or iEPO (mean 0.33, 95% CI -0.0847-0.74, P = 0.11). PAO2:FIO2, OI and VR did not significantly change over a five day period starting the day prior to drug initiation in patients who received either iNO or iEPO assessed with a fixed effects model. Conclusion: Inhaled pulmonary vasodilators were not associated with significant improvement in gas exchange in mechanically ventilated patients with COVID-19

    Inhaled pulmonary vasodilators are not associated with improved gas exchange in mechanically ventilated patients with COVID-19: A retrospective cohort study

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    Purpose: Measure the effect of inhaled pulmonary vasodilators on gas exchange in mechanically ventilated patients with COVID-19. Methods: A retrospective observational cohort study at three New York University Hospitals was performed including eighty-four mechanically ventilated SARS Cov-2 nasopharyngeal PCR positive patients, sixty nine treated with inhaled nitric oxide (iNO) and fifteen with inhaled epoprostenol (iEPO). The primary outcomes were change in PAO2:FIO2 ratio, oxygenation Index (OI), and ventilatory ratio (VR) after initiation of inhaled pulmonary vasodilators. Results: There was no significant change in PAO2:FIO2ratio after initiation of iNO (mean − 4.1, 95% CI -17.3-9.0, P = 0.54) or iEPO (mean − 3.4, 95% CI -19.7-12.9, P = 0.66), in OI after initiation of iNO (mean 2.1, 95% CI-0.04-4.2, P = 0.054) or iEPO (mean − 3.4, 95% CI -19.7-12.9, P = 0.75), or in VR after initiation of iNO (mean 0.17, 95% CI -0.03-0.36, P = 0.25) or iEPO (mean 0.33, 95% CI -0.0847-0.74, P = 0.11). PAO2:FIO2, OI and VR did not significantly change over a five day period starting the day prior to drug initiation in patients who received either iNO or iEPO assessed with a fixed effects model. Conclusion: Inhaled pulmonary vasodilators were not associated with significant improvement in gas exchange in mechanically ventilated patients with COVID-19
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