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Histones are integral components of eukaryotic chromatin that have a pivotal role in the organization and function of the genome. The dynamic regulation of chromatin involves the incorporation of histone variants, which can dramatically alter its structural and functional properties. Contrary to an earlier view that limited individual histone variants to specific genomic functions, new insights have revealed that histone variants exert multifaceted roles involving all aspects of genome function, from governing patterns of gene expression at precise genomic loci to participating in genome replication, repair and maintenance. This conceptual change has led to a new understanding of the intricate interplay between chromatin and DNA-dependent processes and how this connection translates into normal and abnormal cellular functions.
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Arctic and alpine tundra ecosystems are large reservoirs of organic carbon1,2. Climate warming may stimulate ecosystem respiration and release carbon into the atmosphere3,4. The magnitude and persistency of this stimulation and the environmental mechanisms that drive its variation remain uncertain5-7. This hampers the accuracy of global land carbon-climate feedback projections7,8. Here we synthesize 136 datasets from 56 open-top chamber in situ warming experiments located at 28 arctic and alpine tundra sites which have been running for less than 1 year up to 25 years. We show that a mean rise of 1.4 °C [confidence interval (CI) 0.9-2.0 °C] in air and 0.4 °C [CI 0.2-0.7 °C] in soil temperature results in an increase in growing season ecosystem respiration by 30% [CI 22-38%] (n = 136). Our findings indicate that the stimulation of ecosystem respiration was due to increases in both plant-related and microbial respiration (n = 9) and continued for at least 25 years (n = 136). The magnitude of the warming effects on respiration was driven by variation in warming-induced changes in local soil conditions, that is, changes in total nitrogen concentration and pH and by context-dependent spatial variation in these conditions, in particular total nitrogen concentration and the carbon:nitrogen ratio. Tundra sites with stronger nitrogen limitations and sites in which warming had stimulated plant and microbial nutrient turnover seemed particularly sensitive in their respiration response to warming. The results highlight the importance of local soil conditions and warming-induced changes therein for future climatic impacts on respiration.
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Respiración de la Célula , Ecosistema , Calentamiento Global , Tundra , Regiones Árticas , Carbono/metabolismo , Carbono/análisis , Ciclo del Carbono , Conjuntos de Datos como Asunto , Concentración de Iones de Hidrógeno , Nitrógeno/metabolismo , Nitrógeno/análisis , Plantas/metabolismo , Estaciones del Año , Suelo/química , Microbiología del Suelo , Temperatura , Factores de TiempoRESUMEN
This corrects the article DOI: 10.1038/ni.3713.
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Gut dysbiosis might underlie the pathogenesis of type 1 diabetes. In mice of the non-obese diabetic (NOD) strain, we found that key features of disease correlated inversely with blood and fecal concentrations of the microbial metabolites acetate and butyrate. We therefore fed NOD mice specialized diets designed to release large amounts of acetate or butyrate after bacterial fermentation in the colon. Each diet provided a high degree of protection from diabetes, even when administered after breakdown of immunotolerance. Feeding mice a combined acetate- and butyrate-yielding diet provided complete protection, which suggested that acetate and butyrate might operate through distinct mechanisms. Acetate markedly decreased the frequency of autoreactive T cells in lymphoid tissues, through effects on B cells and their ability to expand populations of autoreactive T cells. A diet containing butyrate boosted the number and function of regulatory T cells, whereas acetate- and butyrate-yielding diets enhanced gut integrity and decreased serum concentration of diabetogenic cytokines such as IL-21. Medicinal foods or metabolites might represent an effective and natural approach for countering the numerous immunological defects that contribute to T cell-dependent autoimmune diseases.
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Acetatos/metabolismo , Linfocitos B/inmunología , Butiratos/metabolismo , Colon/metabolismo , Diabetes Mellitus Tipo 1/dietoterapia , Disbiosis/dietoterapia , Linfocitos T Reguladores/inmunología , Animales , Autoinmunidad , Linfocitos B/microbiología , Células Cultivadas , Colon/patología , Dietoterapia , Microbioma Gastrointestinal , Interleucinas/sangre , Ratones , Ratones Endogámicos NOD , Linfocitos T Reguladores/microbiologíaRESUMEN
BACKGROUND: Thrombolytic agents, including tenecteplase, are generally used within 4.5 hours after the onset of stroke symptoms. Information on whether tenecteplase confers benefit beyond 4.5 hours is limited. METHODS: We conducted a multicenter, double-blind, randomized, placebo-controlled trial involving patients with ischemic stroke to compare tenecteplase (0.25 mg per kilogram of body weight, up to 25 mg) with placebo administered 4.5 to 24 hours after the time that the patient was last known to be well. Patients had to have evidence of occlusion of the middle cerebral artery or internal carotid artery and salvageable tissue as determined on perfusion imaging. The primary outcome was the ordinal score on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability and a score of 6 indicating death) at day 90. Safety outcomes included death and symptomatic intracranial hemorrhage. RESULTS: The trial enrolled 458 patients, 77.3% of whom subsequently underwent thrombectomy; 228 patients were assigned to receive tenecteplase, and 230 to receive placebo. The median time between the time the patient was last known to be well and randomization was approximately 12 hours in the tenecteplase group and approximately 13 hours in the placebo group. The median score on the modified Rankin scale at 90 days was 3 in each group. The adjusted common odds ratio for the distribution of scores on the modified Rankin scale at 90 days for tenecteplase as compared with placebo was 1.13 (95% confidence interval, 0.82 to 1.57; P = 0.45). In the safety population, mortality at 90 days was 19.7% in the tenecteplase group and 18.2% in the placebo group, and the incidence of symptomatic intracranial hemorrhage was 3.2% and 2.3%, respectively. CONCLUSIONS: Tenecteplase therapy that was initiated 4.5 to 24 hours after stroke onset in patients with occlusions of the middle cerebral artery or internal carotid artery, most of whom had undergone endovascular thrombectomy, did not result in better clinical outcomes than those with placebo. The incidence of symptomatic intracerebral hemorrhage was similar in the two groups. (Funded by Genentech; TIMELESS ClinicalTrials.gov number, NCT03785678.).
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Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Imagen de Perfusión , Tenecteplasa , Trombectomía , Activador de Tejido Plasminógeno , Humanos , Isquemia Encefálica/diagnóstico por imagen , Isquemia Encefálica/tratamiento farmacológico , Isquemia Encefálica/mortalidad , Isquemia Encefálica/cirugía , Fibrinolíticos/administración & dosificación , Fibrinolíticos/efectos adversos , Fibrinolíticos/uso terapéutico , Hemorragias Intracraneales/inducido químicamente , Hemorragias Intracraneales/diagnóstico por imagen , Perfusión , Imagen de Perfusión/métodos , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/mortalidad , Accidente Cerebrovascular/cirugía , Tenecteplasa/administración & dosificación , Tenecteplasa/efectos adversos , Tenecteplasa/uso terapéutico , Trombectomía/efectos adversos , Trombectomía/métodos , Activador de Tejido Plasminógeno/administración & dosificación , Activador de Tejido Plasminógeno/efectos adversos , Activador de Tejido Plasminógeno/uso terapéutico , Resultado del Tratamiento , Método Doble Ciego , Accidente Cerebrovascular Isquémico/diagnóstico por imagen , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Accidente Cerebrovascular Isquémico/mortalidad , Accidente Cerebrovascular Isquémico/cirugía , Infarto de la Arteria Cerebral Media/diagnóstico por imagen , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Infarto de la Arteria Cerebral Media/cirugía , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/tratamiento farmacológico , Enfermedades de las Arterias Carótidas/cirugía , Encéfalo/irrigación sanguínea , Encéfalo/diagnóstico por imagen , Tiempo de TratamientoRESUMEN
BACKGROUND: Tenecteplase is an effective thrombolytic agent for eligible patients with stroke who are treated within 4.5 hours after the onset of stroke. However, data regarding the effectiveness of tenecteplase beyond 4.5 hours are limited. METHODS: In a trial conducted in China, we randomly assigned patients with large-vessel occlusion of the middle cerebral artery or internal carotid artery who had salvageable brain tissue as identified on perfusion imaging and who did not have access to endovascular thrombectomy to receive tenecteplase (at a dose of 0.25 mg per kilogram of body weight; maximum dose, 25 mg) or standard medical treatment 4.5 to 24 hours after the time that the patient was last known to be well (including after stroke on awakening and unwitnessed stroke). The primary outcome was the absence of disability, which was defined as a score of 0 or 1 on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability), at day 90. The key safety outcomes were symptomatic intracranial hemorrhage and death. RESULTS: A total of 516 patients were enrolled; 264 were randomly assigned to receive tenecteplase and 252 to receive standard medical treatment. Less than 2% of the patients (4 in the tenecteplase group and 5 in the standard-treatment group) underwent rescue endovascular thrombectomy. Treatment with tenecteplase resulted in a higher percentage of patients with a modified Rankin scale score of 0 or 1 at 90 days than standard medical treatment (33.0% vs. 24.2%; relative rate, 1.37; 95% confidence interval, 1.04 to 1.81; P = 0.03). Mortality at 90 days was 13.3% with tenecteplase and 13.1% with standard medical treatment, and the incidence of symptomatic intracranial hemorrhage within 36 hours after treatment was 3.0% and 0.8%, respectively. CONCLUSIONS: In this trial involving Chinese patients with ischemic stroke due to large-vessel occlusion, most of whom did not undergo endovascular thrombectomy, treatment with tenecteplase administered 4.5 to 24 hours after stroke onset resulted in less disability and similar survival as compared with standard medical treatment, and the incidence of symptomatic intracranial hemorrhage appeared to be higher. (Funded by the National Natural Science Foundation of China and others; TRACE-III ClinicalTrials.gov number, NCT05141305.).
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Fibrinolíticos , Accidente Cerebrovascular Isquémico , Tenecteplasa , Tiempo de Tratamiento , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fibrinolíticos/uso terapéutico , Fibrinolíticos/efectos adversos , Fibrinolíticos/administración & dosificación , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Infarto de la Arteria Cerebral Media/cirugía , Hemorragias Intracraneales/etiología , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Accidente Cerebrovascular Isquémico/etiología , Accidente Cerebrovascular Isquémico/cirugía , Tenecteplasa/uso terapéutico , Tenecteplasa/efectos adversos , Trombectomía , Activador de Tejido Plasminógeno/administración & dosificación , Activador de Tejido Plasminógeno/efectos adversos , Activador de Tejido Plasminógeno/uso terapéutico , ChinaRESUMEN
An Amendment to this paper has been published and can be accessed via a link at the top of the paper.
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We describe 2 cases of extensively drug-resistant Pseudomonas aeruginosa infection caused by a strain of public health concern, as it was recently associated with a nationwide outbreak of contaminated artificial tears. Both cases were detected through database review of genomes in the Enhanced Detection System for Hospital-Associated Transmission (EDS-HAT), a routine genome sequencing-based surveillance program. We generated a high-quality reference genome for the outbreak strain from an isolate from our center and examined the mobile elements encoding blaVIM-80 and bla-GES-9 carbapenemases. We used publicly available Pseudomonas aeruginosa genomes to explore the genetic relatedness and antimicrobial resistance genes of the outbreak strain.
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Infecciones por Pseudomonas , Pseudomonas aeruginosa , Humanos , Pseudomonas aeruginosa/genética , Gotas Lubricantes para Ojos , Infecciones por Pseudomonas/tratamiento farmacológico , Infecciones por Pseudomonas/epidemiología , beta-Lactamasas/genética , Secuenciación Completa del Genoma , Brotes de Enfermedades , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Pruebas de Sensibilidad MicrobianaRESUMEN
BACKGROUND: Invasive meningococcal isolates in South Africa have in previous years (<2008) been characterized by serogroup B, C, W and Y lineages over time, with penicillin intermediate resistance (peni) at 6%. We describe the population structure and genomic markers of peni among invasive meningococcal isolates in South Africa, 2016-2021. METHODS: Meningococcal isolates were collected through national, laboratory-based invasive meningococcal disease (IMD) surveillance. Phenotypic antimicrobial susceptibility testing and whole-genome sequencing were performed, and the mechanism of reduced penicillin susceptibility was assessed in silico. RESULTS: Of 585 IMD cases reported during the study period, culture and PCR-based capsular group was determined for 477/585 (82%); and 241/477 (51%) were sequenced. Predominant serogroups included NmB (210/477; 44%), NmW (116/477; 24%), NmY (96/477; 20%) and NmC (48/477; 10%). Predominant clonal complexes (CC) were CC41/44 in NmB (27/113; 24%), CC11 in NmW (46/56; 82%), CC167 in NmY (23/44; 53%), and CC865 in NmC (9/24; 38%). Peni was detected in 16% (42/262) of isolates, and was due to the presence of a penA mosaic, with the majority harboring penA7, penA9 or penA14. CONCLUSION: IMD lineages circulating in South Africa were consistent with those circulating prior to 2008, however peni was higher than previously reported, and occurred in a variety of lineages.
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BACKGROUND: Existing data and clinical trials could not determine whether faster intravenous thrombolytic therapy (IVT) translates into better long-term functional outcomes after acute ischemic stroke among those treated with endovascular thrombectomy (EVT). Patient-level national data can provide the required large population to study the associations between earlier IVT, versus later, with longitudinal functional outcomes and mortality in patients receiving IVT+EVT combined treatment. METHODS: This cohort study included older US patients (age ≥65 years) who received IVT within 4.5 hours or EVT within 7 hours after acute ischemic stroke using the linked 2015 to 2018 Get With The Guidelines-Stroke and Medicare database (38 913 treated with IVT only and 3946 with IVT+EVT). Primary outcome was home time, a patient-prioritized functional outcome. Secondary outcomes included all-cause mortality in 1 year. Multivariate logistic regression and Cox proportional hazards models were used to evaluate the associations between door-to-needle (DTN) times and outcomes. RESULTS: Among patients treated with IVT+EVT, after adjusting for patient and hospital factors, including onset-to-EVT times, each 15-minute increase in DTN times for IVT was associated with significantly higher odds of zero home time in a year (never discharged to home) (adjusted odds ratio, 1.12 [95% CI, 1.06-1.19]), less home time among those discharged to home (adjusted odds ratio, 0.93 per 1% of 365 days [95% CI, 0.89-0.98]), and higher all-cause mortality (adjusted hazard ratio, 1.07 [95% CI, 1.02-1.11]). These associations were also statistically significant among patients treated with IVT but at a modest degree (adjusted odds ratio, 1.04 for zero home time, 0.96 per 1% home time for those discharged to home, and adjusted hazard ratio 1.03 for mortality). In the secondary analysis where the IVT+EVT group was compared with 3704 patients treated with EVT only, shorter DTN times (≤60, 45, and 30 minutes) achieved incrementally more home time in a year, and more modified Rankin Scale 0 to 2 at discharge (22.3%, 23.4%, and 25.0%, respectively) versus EVT only (16.4%, P<0.001 for each). The benefit dissipated with DTN>60 minutes. CONCLUSIONS: Among older patients with stroke treated with either IVT only or IVT+EVT, shorter DTN times are associated with better long-term functional outcomes and lower mortality. These findings support further efforts to accelerate thrombolytic administration in all eligible patients, including EVT candidates.
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Isquemia Encefálica , Procedimientos Endovasculares , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Anciano , Estados Unidos/epidemiología , Accidente Cerebrovascular Isquémico/diagnóstico , Accidente Cerebrovascular Isquémico/terapia , Estudios de Cohortes , Isquemia Encefálica/tratamiento farmacológico , Resultado del Tratamiento , Medicare , Fibrinolíticos/uso terapéutico , Terapia Trombolítica/efectos adversos , Trombectomía/efectos adversos , Procedimientos Endovasculares/efectos adversosRESUMEN
Artificial intelligence (AI) large language models (LLMs) now produce human-like general text and images. LLMs' ability to generate persuasive scientific essays that undergo evaluation under traditional peer review has not been systematically studied. To measure perceptions of quality and the nature of authorship, we conducted a competitive essay contest in 2024 with both human and AI participants. Human authors and 4 distinct LLMs generated essays on controversial topics in stroke care and outcomes research. A panel of Stroke Editorial Board members (mostly vascular neurologists), blinded to author identity and with varying levels of AI expertise, rated the essays for quality, persuasiveness, best in topic, and author type. Among 34 submissions (22 human and 12 LLM) scored by 38 reviewers, human and AI essays received mostly similar ratings, though AI essays were rated higher for composition quality. Author type was accurately identified only 50% of the time, with prior LLM experience associated with improved accuracy. In multivariable analyses adjusted for author attributes and essay quality, only persuasiveness was independently associated with odds of a reviewer assigning AI as author type (adjusted odds ratio, 1.53 [95% CI, 1.09-2.16]; P=0.01). In conclusion, a group of experienced editorial board members struggled to distinguish human versus AI authorship, with a bias against best in topic for essays judged to be AI generated. Scientific journals may benefit from educating reviewers on the types and uses of AI in scientific writing and developing thoughtful policies on the appropriate use of AI in authoring manuscripts.
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Inteligencia Artificial , Accidente Cerebrovascular , Humanos , Accidente Cerebrovascular/diagnóstico , Autoria , Publicaciones Periódicas como Asunto , Revisión de la Investigación por ParesRESUMEN
The Get With The Guidelines-Stroke program which, began 20 years ago, is one of the largest and most important nationally representative disease registries in the United States. Its importance to the stroke community can be gauged by its sustained growth and widespread dissemination of findings that demonstrate sustained increases in both the quality of care and patient outcomes over time. The objectives of this narrative review are to provide a brief history of Get With The Guidelines-Stroke, summarize its major successes and impact, and highlight lessons learned. Looking to the next 20 years, we discuss potential challenges and opportunities for the program.
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Accidente Cerebrovascular , Humanos , Historia del Siglo XXI , Guías de Práctica Clínica como Asunto/normas , Sistema de Registros , Accidente Cerebrovascular/terapia , Estados UnidosRESUMEN
BACKGROUND: The Get With The Guidelines-Stroke program is a quality improvement initiative designed to enhance adherence to evidence-based stroke care. Since its inception in 2003, over 2800 hospitals in the United States have participated in the program. METHODS: We examined patient characteristics, adherence to performance measures, and in-hospital outcomes in patients hospitalized for acute ischemic stroke, subarachnoid hemorrhage, intracerebral hemorrhage, and transient ischemic attack in The Get With The Guidelines-Stroke hospitals from 2003 through 2022. We quantified temporal changes in performance measure adherence and clinical outcomes over time. Performance measure denominators consisted of patients who were eligible, excluding those with contraindications. RESULTS: Over the 20 years of the program, a total of 7837 849 stroke cases (median age 71 years, 51.0% female; 69.2% ischemic strokes, 3.9% SAHs, 11.5% ICHs, and 15.3% TIAs) were entered into the registry. Except for antithrombotics at discharge, in which the baseline performance was >92%, there was sustained improvement in all performance metrics regardless of type of cerebrovascular event (P<0.01 for all). In patients with acute ischemic stroke, large improvements were observed for anticoagulation for atrial fibrillation (55.7% in 2003 to 97.2% in 2022), smoking cessation counseling (44.7%-97.8%), dysphagia screening (53.8%-83.5%), thrombolytic treatment for patients arriving by 3.5 hours, treat by 4.5 hours (15.2%-92.9%), door-to-needle time within 60 minutes (19.0%-75.3%), and endovascular door-to-puncture time within 90 minutes (54.7%-62.8%). Similar improvements were also observed for measures relevant to patients with subarachnoid hemorrhage, intracerebral hemorrhage, and transient ischemic attack. Multivariable analysis showed that there was a sustained increase in odds of receiving each performance measure over time, independent of patient and hospital characteristics for each type of cerebrovascular event. After risk adjustment, there were temporal trends that patients were less likely to be discharged to a skilled nursing facility, and, for ischemic stroke only, more likely to be discharged directly home. CONCLUSIONS: During the first 20 years, Get With The Guidelines-Stroke participation was associated with sustained improvement in evidence-based care and outcomes for patients with stroke and transient ischemic attack in the United States.
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BACKGROUND: Benzodiazepines are commonly prescribed for post-acute ischemic stroke for anxiety, insomnia, and agitation. While guidelines discourage use in those aged ≥65 years, little is known about prescription patterns at the national level. METHODS: We analyzed a 20% sample of US Medicare claims from April 1, 2013, to September 30, 2021. We selected beneficiaries aged ≥65 years discharged alive following an acute ischemic stroke who had traditional Medicare coverage and 6 months' prior enrollment in Parts A (hospital insurance), B (Medical insurance), and D (drug coverage). We excluded those with prior benzodiazepine prescriptions, self-discharges, or discharge to skilled nursing facilities. We examined demographics, comorbidities, first prescription days' supply, cumulative incidences of benzodiazepine first prescription fills within 90 days after discharge, and geographic and yearly trends. RESULTS: We included 126â 050 beneficiaries with a mean age of 78 years (SD, 8); 54% were female and 82% were White. Within 90 days, 6127 (4.9%) initiated a benzodiazepine. Among new prescriptions, lorazepam (40%) and alprazolam (33%) were the most prescribed. Most (76%) of first fills had a day's supply over 7 days and 55% between 15 and 30 days. Female initiation rates were higher (5.5% [95% CI, 5.3-5.7]) than male initiation rates (3.8% [95% CI, 3.6%-3.9%]). Rates were highest in the southeast (5.1% [95% CI, 4.8%-5.3%]) and lowest in the midwest (4.0% [95% CI, 3.8%-4.3%]), with a modest nationwide initiation decline from 2013 to 2021 (cumulative incidence difference, 1.6%). CONCLUSIONS: Despite a gradual decline in benzodiazepine initiation from 2013 to 2021, we noted excessive supplies in prescriptions post-acute ischemic stroke discharge, underscoring the need for improved policies.
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BACKGROUND: Delays in hospital presentation limit access to acute stroke treatments. While prior research has focused on patient-level factors, broader ecological and social determinants have not been well studied. We aimed to create a geospatial map of prehospital delay and examine the role of community-level social vulnerability. METHODS: We studied patients with ischemic stroke who arrived by emergency medical services in 2015 to 2017 from the American Heart Association Get With The Guidelines-Stroke registry. The primary outcome was time to hospital arrival after stroke (in minutes), beginning at last known well in most cases. Using Geographic Information System mapping, we displayed the geography of delay. We then used Cox proportional hazard models to study the relationship between community-level factors and arrival time (adjusted hazard ratios [aHR] <1.0 indicate delay). The primary exposure was the social vulnerability index (SVI), a metric of social vulnerability for every ZIP Code Tabulation Area ranging from 0.0 to 1.0. RESULTS: Of 750â 336 patients, 149â 145 met inclusion criteria. The mean age was 73 years, and 51% were female. The median time to hospital arrival was 140 minutes (Q1: 60 minutes, Q3: 458 minutes). The geospatial map revealed that many zones of delay overlapped with socially vulnerable areas (https://harvard-cga.maps.arcgis.com/apps/webappviewer/index.html?id=08f6e885c71b457f83cefc71013bcaa7). Cox models (aHR, 95% CI) confirmed that higher SVI, including quartiles 3 (aHR, 0.96 [95% CI, 0.93-0.98]) and 4 (aHR, 0.93 [95% CI, 0.91-0.95]), was associated with delay. Patients from SVI quartile 4 neighborhoods arrived 15.6 minutes [15-16.2] slower than patients from SVI quartile 1. Specific SVI themes associated with delay were a community's socioeconomic status (aHR, 0.80 [95% CI, 0.74-0.85]) and housing type and transportation (aHR, 0.89 [95% CI, 0.84-0.94]). CONCLUSIONS: This map of acute stroke presentation times shows areas with a high incidence of delay. Increased social vulnerability characterizes these areas. Such places should be systematically targeted to improve population-level stroke presentation times.
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Hospitalización , Accidente Cerebrovascular Isquémico , Sistema de Registros , Tiempo de Tratamiento , Tiempo de Tratamiento/estadística & datos numéricos , Humanos , Masculino , Femenino , Persona de Mediana Edad , Anciano , Lagunas en las Evidencias , Accidente Cerebrovascular Isquémico/epidemiología , Accidente Cerebrovascular Isquémico/terapia , Hospitalización/estadística & datos numéricos , Estados Unidos/epidemiología , Análisis Espacio-Temporal , Mapeo Geográfico , Modelos de Riesgos Proporcionales , Servicios Médicos de Urgencia/estadística & datos numéricosRESUMEN
BACKGROUND: Stroke with unknown time of onset can be categorized into 2 groups; wake-up stroke (WUS) and unwitnessed stroke with an onset time unavailable for reasons other than wake-up (non-wake-up unwitnessed stroke, non-WUS). We aimed to assess potential differences in the efficacy and safety of intravenous thrombolysis (IVT) between these subgroups. METHODS: Patients with an unknown-onset stroke were evaluated using individual patient-level data of 2 randomized controlled trials (WAKE-UP [Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke], THAWS [Thrombolysis for Acute Wake-Up and Unclear-Onset Strokes With Alteplase at 0.6 mg/kg]) comparing IVT with placebo or standard treatment from the EOS (Evaluation of Unknown-Onset Stroke Thrombolysis trial) data set. A favorable outcome was prespecified as a modified Rankin Scale score of 0 to 1 at 90 days. Safety outcomes included symptomatic intracranial hemorrhage at 22 to 36 hours and 90-day mortality. The IVT effect was compared between the treatment groups in the WUS and non-WUS with multivariable logistic regression analysis. RESULTS: Six hundred thirty-four patients from 2 trials were analyzed; 542 had WUS (191 women, 272 receiving alteplase), and 92 had non-WUS (42 women, 43 receiving alteplase). Overall, no significant interaction was noted between the mode of onset and treatment effect (P value for interaction=0.796). In patients with WUS, the frequencies of favorable outcomes were 54.8% and 45.5% in the IVT and control groups, respectively (adjusted odds ratio, 1.47 [95% CI, 1.01-2.16]). Death occurred in 4.0% and 1.9%, respectively (P=0.162), and symptomatic intracranial hemorrhage in 1.8% and 0.3%, respectively (P=0.194). In patients with non-WUS, no significant difference was observed in favorable outcomes relative to the control (37.2% versus 29.2%; adjusted odds ratio, 1.76 [0.58-5.37]). One death and one symptomatic intracranial hemorrhage were reported in the IVT group, but none in the control. CONCLUSIONS: There was no difference in the effect of IVT between patients with WUS and non-WUS. IVT showed a significant benefit in patients with WUS, while there was insufficient statistical power to detect a substantial benefit in the non-WUS subgroup. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: CRD42020166903.
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Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Femenino , Activador de Tejido Plasminógeno , Fibrinolíticos , Terapia Trombolítica/efectos adversos , Resultado del Tratamiento , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/inducido químicamente , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Hemorragias Intracraneales/etiología , Isquemia Encefálica/tratamiento farmacológicoRESUMEN
BACKGROUND: There is increasing interest in replacing alteplase with tenecteplase as the preferred thrombolytic treatment for patients with acute ischaemic stroke. We aimed to establish the non-inferiority of tenecteplase to alteplase for these patients. METHODS: In this multicentre, prospective, open-label, blinded-endpoint, randomised controlled, non-inferiority trial, adults with an acute ischaemic stroke who were eligible for standard intravenous thrombolysis but ineligible for endovascular thrombectomy were enrolled from 53 centres in China and randomly assigned (1:1) to receive intravenous tenecteplase (0·25 mg/kg, maximum dose of 25 mg) or intravenous alteplase (0·9 mg/kg, maximum dose of 90 mg). Participants had to be able to receive treatment within 4·5 h of stroke, have a modified Rankin Scale (mRS) score of no more than 1 before enrolment, and have a National Institutes of Health Stroke Scale score of 5-25. Patients and treating clinicians were not masked to group assignment; clinicians evaluating outcomes were masked to treatment type. The primary efficacy outcome was the proportion of participants who had a mRS score of 0-1 at 90 days, assessed in the modified intention-to-treat population (all randomly assigned participants who received the allocated thrombolytic), with a non-inferiority margin of 0·937 for the risk ratio (RR). The primary safety outcome was symptomatic intracranial haemorrhage within 36 h, assessed in all participants who received study drug and had a safety assessment available. The trial is registered with ClinicalTrials.gov, NCT04797013, and has been completed. FINDINGS: Between June 12, 2021, and May 29, 2022, 1430 participants were enrolled and randomly assigned to tenecteplase (n=716) or alteplase (n=714). Six patients assigned to tenecteplase and seven to alteplase did not receive study product, and five participants in the tenecteplase group and 11 in the alteplase group were lost to follow-up at 90 days. The primary outcome in the modified intention-to-treat population occurred in 439 (62%) of 705 in the tenecteplase group versus 405 (58%) of 696 in the alteplase group (RR 1·07, 95% CI 0·98-1·16). The lower limit of the RR's 95% CI was greater than the non-inferiority margin. Symptomatic intracranial haemorrhage within 36 h was observed in 15 (2%) of 711 in the tenecteplase group and 13 (2%) of 706 in the alteplase group (RR 1·18, 95% CI 0·56-2·50). Mortality within 90 days occurred in 46 (7%) individuals in the tenecteplase group versus 35 (5%) in the alteplase group (RR 1·31, 95% CI 0·86-2·01). INTERPRETATION: Tenecteplase was non-inferior to alteplase in people with ischaemic stroke who were eligible for standard intravenous thrombolytic but ineligible for or refused endovascular thrombectomy. FUNDING: National Science and Technology Major Project, Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences, National Natural Science Foundation of China, and China Shijiazhuang Pharmaceutical Company Recomgen Pharmaceutical (Guangzhou).
Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Tenecteplasa , Activador de Tejido Plasminógeno , Adulto , Humanos , Isquemia Encefálica/tratamiento farmacológico , Fibrinolíticos/uso terapéutico , Hemorragias Intracraneales , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Estudios Prospectivos , Tenecteplasa/uso terapéutico , Activador de Tejido Plasminógeno/uso terapéutico , Resultado del TratamientoRESUMEN
Tropical forest root characteristics and resource acquisition strategies are underrepresented in vegetation and global models, hampering the prediction of forest-climate feedbacks for these carbon-rich ecosystems. Lowland tropical forests often have globally unique combinations of high taxonomic and functional biodiversity, rainfall seasonality, and strongly weathered infertile soils, giving rise to distinct patterns in root traits and functions compared with higher latitude ecosystems. We provide a roadmap for integrating recent advances in our understanding of tropical forest belowground function into vegetation models, focusing on water and nutrient acquisition. We offer comparisons of recent advances in empirical and model understanding of root characteristics that represent important functional processes in tropical forests. We focus on: (1) fine-root strategies for soil resource exploration, (2) coupling and trade-offs in fine-root water vs nutrient acquisition, and (3) aboveground-belowground linkages in plant resource acquisition and use. We suggest avenues for representing these extremely diverse plant communities in computationally manageable and ecologically meaningful groups in models for linked aboveground-belowground hydro-nutrient functions. Tropical forests are undergoing warming, shifting rainfall regimes, and exacerbation of soil nutrient scarcity caused by elevated atmospheric CO2. The accurate model representation of tropical forest functions is crucial for understanding the interactions of this biome with the climate.
Las características de las raíces de los bosques tropicales y las estrategias de adquisición de recursos están subrepresentadas en modelos de vegetación, lo que dificulta la predicción del efecto de cambio de clima para estos ecosistemas ricos en carbono. Los bosques tropicales a menudo tienen combinaciones únicas a nivel mundial de alta biodiversidad taxonómica y funcional, estacionalidad de precipitación, y suelos infértiles, dando lugar a patrones distintos en los rasgos y funciones de las raíces en comparación con los ecosistemas de latitudes más altas. Integramos los avances recientes en nuestra comprensión de la función subterránea de los bosques tropicales en modelos de vegetación, centrándonos en la adquisición de agua y nutrientes. Ofrecemos comparaciones de avances recientes en la comprensión empírica y de modelos de las características de las raíces que representan procesos funcionales importantes en los bosques tropicales. Nos centramos en: (1) estrategias de raíces finas para adquisición de recursos del suelo, (2) acoplamiento y compensaciones entre adquisición del agua y de nutrientes, y (3) vínculos entre funciones sobre tierra y debajo del superficie en bosques tropicales. Sugerimos vías para representar estas comunidades de plantas extremadamente diversas en grupos computacionalmente manejables y ecológicamente significativos en modelos. Los bosques tropicales se están calentando, tienen cambios en los regímenes de lluvias, y tienen una exacerbación de la escasez de nutrientes del suelo causada por el elevado CO2 atmosférico. La representación precisa de las funciones de los bosques tropicales en modelos es crucial para comprender las interacciones de este bioma con el clima.
Asunto(s)
Ecosistema , Raíces de Plantas , Nitrógeno , Bosques , Suelo , Plantas , Agua , Clima Tropical , ÁrbolesRESUMEN
OBJECTIVE: We aimed to characterize the association of hospital procedural volumes with outcomes among acute ischemic stroke (AIS) patients undergoing endovascular therapy (EVT). METHODS: This was a retrospective, observational cohort study using data prospectively collected from January 1, 2016 to December 31, 2019 in the Get with the Guidelines-Stroke registry. Participants were derived from a cohort of 60,727 AIS patients treated with EVT within 24 hours at 626 hospitals. The primary cohort excluded patients with pretreatment National Institutes of Health Stroke Scale (NIHSS) < 6, onset-to-treatment time > 6 hours, and interhospital transfers. There were 2 secondary cohorts: (1) the EVT metrics cohort excluded patients with missing data on time from door to arterial puncture and (2) the intravenous thrombolysis (IVT) metrics cohort only included patients receiving IVT ≤4.5 hours after onset. RESULTS: The primary cohort (mean ± standard deviation age = 70.7 ± 14.8 years; 51.2% female; median [interquartile range] baseline NIHSS = 18.0 [13-22]; IVT use, 70.2%) comprised 21,209 patients across 595 hospitals. The EVT metrics cohort and IVT metrics cohort comprised 47,262 and 16,889 patients across 408 and 601 hospitals, respectively. Higher procedural volumes were significantly associated with higher odds (expressed as adjusted odds ratio [95% confidence interval] for every 10-case increase in volume) of discharge to home (1.03 [1.02-1.04]), functional independence at discharge (1.02 [1.01-1.04]), and lower rates of in-hospital mortality (0.96 [0.95-0.98]). All secondary measures were also associated with procedural volumes. INTERPRETATION: Among AIS patients primarily presenting to EVT-capable hospitals (excluding those transferred from one facility to another and those suffering in-hospital strokes), EVT at hospitals with higher procedural volumes was associated with faster treatment times, better discharge outcomes, and lower rates of in-hospital mortality. ANN NEUROL 2023.