37 research outputs found
The Evolution of Active Droplets in Chemorobotic Platforms
There is great interest in oil-in-water droplets as simple systems that display astonishingly complex behaviours. Recently, we reported a chemorobotic platform capable of autonomously exploring and evolving the behaviours these droplets can exhibit. The platform enabled us to undertake a large number of reproducible experiments, allowing us to probe the non-linear relationship between droplet composition and behaviour. Herein we introduce this work, and also report on the recent developments we have made to this system. These include new platforms to simultaneously evolve the droplets’ physical and chemical environments and the inclusion of selfreplicating molecules in the droplets
Adaptive artificial evolution of droplet protocells in a 3D-printed fluidic chemorobotic platform with configurable environments
Few studies have explored the effect of a changing environment on artificial chemical evolution. Here, the authors develop an evolutionary platform that alters the physical environment of droplet protocells, showing that a population of simple chemical species can adapt to its surroundings, in analogy to natural evolution
Grape ASR-Silencing Sways Nuclear Proteome, Histone Marks and Interplay of Intrinsically Disordered Proteins
In order to unravel the functions of ASR (Abscisic acid, Stress, Ripening-induced) proteins in the nucleus, we created a new model of genetically transformed grape embryogenic cells by RNAi-knockdown of grape ASR (VvMSA). Nuclear proteomes of wild-type and VvMSA-RNAi grape cell lines were analyzed by quantitative isobaric tagging (iTRAQ 8-plex). The most significantly up- or down-regulated nuclear proteins were involved in epigenetic regulation, DNA replication/repair, transcription, mRNA splicing/stability/editing, rRNA processing/biogenesis, metabolism, cell division/differentiation and stress responses. The spectacular up-regulation in VvMSA-silenced cells was that of the stress response protein VvLEA D-29 (Late Embryogenesis Abundant). Both VvMSA and VvLEA D-29 genes displayed strong and contrasted responsiveness to auxin depletion, repression of VvMSA and induction of VvLEA D-29. In silico analysis of VvMSA and VvLEA D-29 proteins highlighted their intrinsically disordered nature and possible compensatory relationship. Semi-quantitative evaluation by medium-throughput immunoblotting of eighteen post-translational modifications of histones H3 and H4 in VvMSA-knockdown cells showed significant enrichment/depletion of the histone marks H3K4me1, H3K4me3, H3K9me1, H3K9me2, H3K36me2, H3K36me3 and H4K16ac. We demonstrate that grape ASR repression differentially affects members of complex nucleoprotein structures and may not only act as molecular chaperone/transcription factor, but also participates in plant responses to developmental and environmental cues through epigenetic mechanisms
Efectos clinicos e histopatologicos agudos y subagudos del veneno de Tityus breweri en miocardio de hamsters
Scorpions of the genus Tityus present the largest distributionof the world, of greater clinical, epidemiological and moredangerous importance of the American continent. The toxinsfrom its venom produce severe disturbance of the excitationand conduction processes of the nerve impulse. From thehistopathological point of view structural changes have beenobserved in different tissues of mice, with the venom of severalspecies of Venezuelan Tityus. Objective: To describe the acuteand subacute clinical and histopathological effects of scorpionvenom (Buthidae: T. breweri) on the hamster myocardium.Method: Experimental, exploratory, descriptive, analyticaland correlational study. Hersters of both sexes of thegenus Cricetus were obtained and venom of 26 T. breweriscorpions were obtained, 6 random hamsters were chosen,injecting intravenously (VIP) venom of Tityus breweri, 3sacrificed at 30 minutes and the other 3 a The 60 minutes,3 injected with distilled water constituted the control group.Results: Most of the exposed animals presented cholinergicand adrenergic type manifestations. The acute histopathologicalalterations observed were interfascicular edema and vascularcongestion, perivascular lymphohistiocytic infiltrate. At theend of 12, 24, 48 and 72 hours of exposure of the venom, nohistopathological changes were evidenced, which suggeststhat the repair processes of the damaged tissues were activated.Conclusion: T. breweri venom caused acute and subacutehistological alterations in myocardial tissue in hamsters withno evidence of alteration in the control group.Los escorpiones del género Tityus presentan la mayor distribución mundial, de mayor importancia clínica, epidemiológica y más peligrosa del continente americano. Las toxinas de su veneno producen perturbación severa de los procesos de excitación y conducción del impulso nervioso. Desde el punto de vista histopatológicos se han observado cambios estructurales en diferentes tejidos de ratones, con el veneno de varias especies de Tityus venezolanos. Objetivo: Describir los efectos clínicos e histopatológicos agudos y subagudos del veneno de escorpión (Buthidae: T. breweri) en el miocardio de hámster. Método: Estudio experimental, exploratoria, descriptivo, analítica y correlacional. Se utilizaron hámsteres de ambos sexos del genero Cricetus y se obtuvo el veneno de 26 escorpiones T. breweri, se escogieron 6 hámster al azar, inyectándoles vía intraperitonial (VIP) veneno de Tityus breweri, 3 sacrificados a los 30 minutos y los otros 3 a los 60 minutos, 3 inyectados con agua destilada constituyeron el grupo control. Resultados: La mayoría de los animales expuestos presentaron manifestaciones de tipo colinérgicas y adrenérgicas. Las alteraciones histopatológicas agudas observadas fueron edema interfascicular y congestión vascular, infiltrado linfohistiocítico perivascular. Al transcurrir 12, 24, 48 y 72 horas de exposición del veneno, no se evidenciaron cambios histopatológicos, lo que hace presumir que se activaron los procesos de reparación de los tejidos dañados. Conclusión: el veneno de T. breweri produjo alteración histológicas agudas y subagudas en el tejido miocárdico en los hámsteres sin evidencia de alteración en el grupo control.
 
Efectos clinicos e histopatologicos agudos y subagudos del veneno de Tityus breweri en miocardio de hamsters
Scorpions of the genus Tityus present the largest distributionof the world, of greater clinical, epidemiological and moredangerous importance of the American continent. The toxinsfrom its venom produce severe disturbance of the excitationand conduction processes of the nerve impulse. From thehistopathological point of view structural changes have beenobserved in different tissues of mice, with the venom of severalspecies of Venezuelan Tityus. Objective: To describe the acuteand subacute clinical and histopathological effects of scorpionvenom (Buthidae: T. breweri) on the hamster myocardium.Method: Experimental, exploratory, descriptive, analyticaland correlational study. Hersters of both sexes of thegenus Cricetus were obtained and venom of 26 T. breweriscorpions were obtained, 6 random hamsters were chosen,injecting intravenously (VIP) venom of Tityus breweri, 3sacrificed at 30 minutes and the other 3 a The 60 minutes,3 injected with distilled water constituted the control group.Results: Most of the exposed animals presented cholinergicand adrenergic type manifestations. The acute histopathologicalalterations observed were interfascicular edema and vascularcongestion, perivascular lymphohistiocytic infiltrate. At theend of 12, 24, 48 and 72 hours of exposure of the venom, nohistopathological changes were evidenced, which suggeststhat the repair processes of the damaged tissues were activated.Conclusion: T. breweri venom caused acute and subacutehistological alterations in myocardial tissue in hamsters withno evidence of alteration in the control group.Los escorpiones del género Tityus presentan la mayor distribución mundial, de mayor importancia clínica, epidemiológica y más peligrosa del continente americano. Las toxinas de su veneno producen perturbación severa de los procesos de excitación y conducción del impulso nervioso. Desde el punto de vista histopatológicos se han observado cambios estructurales en diferentes tejidos de ratones, con el veneno de varias especies de Tityus venezolanos. Objetivo: Describir los efectos clínicos e histopatológicos agudos y subagudos del veneno de escorpión (Buthidae: T. breweri) en el miocardio de hámster. Método: Estudio experimental, exploratoria, descriptivo, analítica y correlacional. Se utilizaron hámsteres de ambos sexos del genero Cricetus y se obtuvo el veneno de 26 escorpiones T. breweri, se escogieron 6 hámster al azar, inyectándoles vía intraperitonial (VIP) veneno de Tityus breweri, 3 sacrificados a los 30 minutos y los otros 3 a los 60 minutos, 3 inyectados con agua destilada constituyeron el grupo control. Resultados: La mayoría de los animales expuestos presentaron manifestaciones de tipo colinérgicas y adrenérgicas. Las alteraciones histopatológicas agudas observadas fueron edema interfascicular y congestión vascular, infiltrado linfohistiocítico perivascular. Al transcurrir 12, 24, 48 y 72 horas de exposición del veneno, no se evidenciaron cambios histopatológicos, lo que hace presumir que se activaron los procesos de reparación de los tejidos dañados. Conclusión: el veneno de T. breweri produjo alteración histológicas agudas y subagudas en el tejido miocárdico en los hámsteres sin evidencia de alteración en el grupo control.
 
Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study
Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe
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Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.
Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707
Physiological functions of ASR proteins regarding sugar signaling, transport and metabolism in two cell culture models in grapevine
Les sucres, sont des signaux métaboliques, impliqués dans le développement des plantes et leurs réponses aux contraintes du milieu. Les transporteurs de sucres se révèlent à la fois acteurs de la répartition des sucres et cibles de leur signalisation. L'ASR (ABA, Stress and Ripening) de la Vigne, VvMSA, étant identifiée comme protéine régulatrice de l'expression génique du transporteur d’hexoses VvHT1, l'objectif de la thèse est d'appréhender ses rôles physiologiques dans une démarche de biologie intégrée.Le premier axe a été dédié à la mise en place des modèles biologiques, des cellules embryogènes et non embryogènes de Vigne, issues du même fond génétique mais cultivées sur deux sources de carbone différentes. La caractérisation des cinétiques de prolifération et l'analyse des métabolomes ont mis en évidence leur sensibilité/tolérance différentielle à la carence en sucres. Le deuxième axe a porté sur la régulation de VvHT1 dans les deux types cellulaires sauvages et leurs mutants de surexpression/répression de VvMSA. L'approche pharmacologique utilisant des analogues du glucose, l'analyse de l'expression génique, le transport du glucose et l'activité des enzymes de la glycolyse indiquent que VvMSA affecte l'expression de VvHT1 par la voie dépendante du métabolisme du glucose. Le troisième volet a été réalisé par une approche de protéomique quantitative et comparative des protéines nucléaires des cellules embryogènes sauvages et réprimées pour VvMSA. Les protéines à expression significativement affectée par l'absence de l'ASR, laissent entrevoir un nouveau rôle à l'interconnexion des réponses métaboliques aux stress et la régulation épigénétique de l'expression génique.Sugars are metabolic signals involved in plant development and responses to environmental cues. Sugar transporters are both actors of sugar partitioning and targets of sugar signaling. As Grape ASR (ABA, Stress, Ripening), VvMSA, is identified as a regulatory protein controlling gene expression of the hexose transporter VvHT1, the aim of the PhD thesis is to assess its physiological functions by an integrative biology approach. The first part of the study consisted in the establishment of biological models, embryogenic and non embryogenic grape cells, sharing the same genetic background but growing on distinct carbon sources. The characterization of the proliferation kinetics and metabolomes of both cell types revealed differences in their sensitivity/tolerance to sugar starvation.The second objective was focused on VvHT1 expression regulation in both cell types and their mutants overexpressing or silenced for VvMSA. The pharmacological approach using glucose analogues, coupled to the analysis of gene expression, glucose transport and glycolytic enzymes activity, suggest that VvMSA affects VvHT1 expression through a glucose metabolism dependent pathway.The third research axis was carried out through a quantitative and comparative proteomic analysis of nuclear proteins in embryogenic wild type and VvMSA silenced cells. Proteins whose expression is affected by ASR repression suggest a new functional role of VvMSA at the interplay between metabolic responses to stress and epigenetic regulation of gene expression