Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 259
Filtrar
1.
Plant J ; 118(3): 607-625, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38361340

RESUMEN

The conservation of GOLVEN (GLV)/ROOT MERISTEM GROWTH FACTOR (RGF) peptide encoding genes across plant genomes capable of forming roots or root-like structures underscores their potential significance in the terrestrial adaptation of plants. This study investigates the function and role of GOLVEN peptide-coding genes in Medicago truncatula. Five out of fifteen GLV/RGF genes were notably upregulated during nodule organogenesis and were differentially responsive to nitrogen deficiency and auxin treatment. Specifically, the expression of MtGLV9 and MtGLV10 at nodule initiation sites was contingent upon the NODULE INCEPTION transcription factor. Overexpression of these five nodule-induced GLV genes in hairy roots of M. truncatula and application of their synthetic peptide analogues led to a decrease in nodule count by 25-50%. Uniquely, the GOLVEN10 peptide altered the positioning of the first formed lateral root and nodule on the primary root axis, an observation we term 'noduletaxis'; this decreased the length of the lateral organ formation zone on roots. Histological section of roots treated with synthetic GOLVEN10 peptide revealed an increased cell number within the root cortical cell layers without a corresponding increase in cell length, leading to an elongation of the root likely introducing a spatiotemporal delay in organ formation. At the transcription level, the GOLVEN10 peptide suppressed expression of microtubule-related genes and exerted its effects by changing expression of a large subset of Auxin responsive genes. These findings advance our understanding of the molecular mechanisms by which GOLVEN peptides modulate root morphology, nodule ontogeny, and interactions with key transcriptional pathways.


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Medicago truncatula , Proteínas de Plantas , Raíces de Plantas , Nódulos de las Raíces de las Plantas , Medicago truncatula/genética , Medicago truncatula/crecimiento & desarrollo , Medicago truncatula/metabolismo , Medicago truncatula/efectos de los fármacos , Medicago truncatula/fisiología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/genética , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/metabolismo , Nódulos de las Raíces de las Plantas/genética , Nódulos de las Raíces de las Plantas/crecimiento & desarrollo , Nódulos de las Raíces de las Plantas/metabolismo , Nódulos de las Raíces de las Plantas/efectos de los fármacos , Ácidos Indolacéticos/metabolismo , Ácidos Indolacéticos/farmacología , Nodulación de la Raíz de la Planta/genética , Meristema/genética , Meristema/crecimiento & desarrollo , Meristema/efectos de los fármacos , Péptidos/metabolismo , Péptidos/genética
2.
Plant Physiol ; 191(1): 643-659, 2023 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-36264121

RESUMEN

To cope with environmental stresses and ensure maximal reproductive success, plants have developed strategies to adjust the timing of their transition to reproductive growth. This has a substantial impact on the stress resilience of crops and ultimately on agricultural productivity. Here, we report a previously uncharacterized, plant-specific gene family designated as Regulator of Flowering and Stress (RFS). Overexpression of the BdRFS gene in Brachypodium distachyon delayed flowering, increased biomass accumulation, and promoted drought tolerance, whereas clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9)-mediated knockout mutants exhibited opposite phenotypes. A double T-DNA insertional mutant in the two Arabidopsis (Arabidopsis thaliana) homologs replicated the effects on flowering and water deprivation seen in the B. distachyon CRISPR knockout lines, highlighting the functional conservation of the family between monocots and dicots. Lipid analysis of B. distachyon and Arabidopsis revealed that digalactosyldiacylglycerol (DGDG) and phosphatidylcholine (PC) contents were significantly, and reciprocally, altered in overexpressor and knockout mutants. Importantly, alteration of C16:0-containing PC, a Flowering Locus T-interacting lipid, associated with flowering phenotype, with elevated levels corresponding to earlier flowering. Co-immunoprecipitation analysis suggested that BdRFS interacts with phospholipase Dα1 as well as several other abscisic acid-related proteins. Furthermore, reduction of C18:3 fatty acids in DGDG corresponded with reduced jasmonic acid metabolites in CRISPR mutants. Collectively, we suggest that stress-inducible RFS proteins represent a regulatory component of lipid metabolism that impacts several agronomic traits of biotechnological importance.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Brachypodium , Arabidopsis/metabolismo , Brachypodium/metabolismo , Resistencia a la Sequía , Proteínas de Choque Térmico/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Lípidos , Regulación de la Expresión Génica de las Plantas
3.
Ann Neurol ; 93(3): 479-488, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36373166

RESUMEN

OBJECTIVE: Approximately 20% of strokes are embolic strokes of undetermined source (ESUS). Undetected atrial fibrillation (AF) remains an important cause. Yet, oral anticoagulation in unselected ESUS patients failed in secondary stroke prevention. Guidance on effective AF detection is lacking. Here, we introduce a novel, non-invasive AF risk assessment after ESUS. METHODS: Catch-Up ESUS is an investigator-initiated, observational cohort study conducted between 2018 and 2019 at the Munich University Hospital. Besides clinical characteristics, patients received ≥72 h digital electrocardiogram recordings to generate the rhythm irregularity burden. Uni- and multivariable regression models predicted the primary endpoint of incident AF, ascertained by standardized follow-up including implantable cardiac monitors. Predictors included the novel rhythm irregularity burden constructed from digital electrocardiogram recordings. We independently validated our model in ESUS patients from the University Hospital Tübingen, Germany. RESULTS: A total of 297 ESUS patients were followed for 15.6 ± 7.6 months. Incident AF (46 patients, 15.4%) occurred after a median of 105 days (25th to 75th percentile 31-33 days). Secondary outcomes were recurrent stroke in 7.7% and death in 6.1%. Multivariable-adjusted analyses identified the rhythm irregularity burden as the strongest AF-predictor (hazard ratio 3.12, 95% confidence interval 1.62-5.80, p < 0001) while accounting for the known risk factors age, CHA2 DS2 -VASc-Score, and NT-proBNP. Independent validation confirmed the rhythm irregularity burden as the most significant AF-predictor (hazard ratio 2.20, 95% confidence interval 1.45-3.33, p < 0001). INTERPRETATION: The novel, non-invasive, electrocardiogram-based rhythm irregularity burden may help adjudicating AF risk after ESUS, and subsequently guide AF-detection after ESUS. Clinical trials need to clarify if high-AF risk patients benefit from tailored secondary stroke prevention. ANN NEUROL 2023;93:479-488.


Asunto(s)
Fibrilación Atrial , Accidente Cerebrovascular Embólico , Embolia Intracraneal , Accidente Cerebrovascular , Humanos , Fibrilación Atrial/complicaciones , Accidente Cerebrovascular Embólico/complicaciones , Medición de Riesgo , Factores de Riesgo , Embolia Intracraneal/etiología
4.
BMC Neurol ; 24(1): 249, 2024 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-39039495

RESUMEN

BACKGROUND: CHANTER (Cerebellar Hippocampal and Basal Nuclei Transient Edema with Restricted diffusion) is a recently described syndrome occurring in the context of drug abuse. While clinical findings are rather unspecific (disorientation, unresponsiveness), MR imaging (MRI) discloses a characteristic pattern (restricted diffusion in the basal ganglia and hippocampi, cerebellar oedema and haemorrhage), allowing for timely diagnosis before complications such as cerebellar swelling and herniation do occur. Here we report a case of CHANTER primarily based on imaging findings, as there was no evidence of drug abuse on admission. CASE PRESENTATION: A 62-year-old Patient was admitted to our hospital after being unresponsive at home. Prehospital intubation was performed, which limited neurological assessment. Under these circumstances no obvious symptoms could be determined, i.e. pupils were isocoric and responsive, and there were no signs of seizures. While the initial CT scan was unremarkable, the subsequent MRI scan showed a distinct imaging pattern: moderately enhancing areas in the basal ganglia and hippocampi with diffusion restriction, accompanied by cerebellar haemorrhage and oedema (Figs. 1 and 2). A comprehensive clinical and laboratory work-up was performed, including drug screening, spinal tap, Holter ECG, echocardiography and EEG. The only conspicuous anamnestic finding was a chronic pain syndrome whose medication had been supplemented with opioids two months previously. The opioid medication was discontinued, which led to a rapid improvement in the patient's clinical condition without any further measures. The patient was able to leave the intensive care unit and was discharged 10 days after admission without persistent neurological deficits. CONCLUSION: Familiarity with typical MRI patterns of toxic encephalopathy in patients from high-risk groups, such as drug abusers, is crucial in emergency neuroradiology. In the presence of typical MRI findings, CHANTER syndrome should be included in the differential diagnosis, even if there is no history of drug abuse, to avoid delay in diagnosis and treatment.


Asunto(s)
Imagen por Resonancia Magnética , Humanos , Persona de Mediana Edad , Ganglios Basales/diagnóstico por imagen , Ganglios Basales/patología , Edema Encefálico/diagnóstico por imagen , Edema Encefálico/inducido químicamente , Hipocampo/diagnóstico por imagen , Hipocampo/patología , Imagen por Resonancia Magnética/métodos , Síndrome
5.
Am Heart J ; 265: 66-76, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37422010

RESUMEN

BACKGROUND: Atrial fibrillation (AF) is one of the most frequent causes of stroke. Several randomized trials have shown that prolonged monitoring increases the detection of AF, but the effect on reducing recurrent cardioembolism, ie, ischemic stroke and systemic embolism, remains unknown. We aim to evaluate whether a risk-adapted, intensified heart rhythm monitoring with consequent guideline conform treatment, which implies initiation of oral anticoagulation (OAC), leads to a reduction of recurrent cardioembolism. METHODS: Find-AF 2 is a randomized, controlled, open-label parallel multicenter trial with blinded endpoint assessment. 5,200 patients ≥ 60 years of age with symptomatic ischemic stroke within the last 30 days and without known AF will be included at 52 study centers with a specialized stroke unit in Germany. Patients without AF in an additional 24-hour Holter ECG after the qualifying event will be randomized in a 1:1 fashion to either enhanced, prolonged and intensified ECG-monitoring (intervention arm) or standard of care monitoring (control arm). In the intervention arm, patients with a high risk of underlying AF will receive continuous rhythm monitoring using an implantable cardiac monitor (ICM) whereas those without high risk of underlying AF will receive repeated 7-day Holter ECGs. The duration of rhythm monitoring within the control arm is up to the discretion of the participating centers and is allowed for up to 7 days. Patients will be followed for at least 24 months. The primary efficacy endpoint is the time until recurrent ischemic stroke or systemic embolism occur. CONCLUSIONS: The Find-AF 2 trial aims to demonstrate that enhanced, prolonged and intensified rhythm monitoring results in a more effective prevention of recurrent ischemic stroke and systemic embolism compared to usual care.


Asunto(s)
Fibrilación Atrial , Embolia , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Lactante , Fibrilación Atrial/complicaciones , Fibrilación Atrial/diagnóstico , Furilfuramida , Estudios Prospectivos , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/prevención & control , Accidente Cerebrovascular/diagnóstico , Electrocardiografía Ambulatoria/métodos , Embolia/diagnóstico , Embolia/etiología , Embolia/prevención & control
6.
J Exp Bot ; 74(6): 2083-2111, 2023 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-36629302

RESUMEN

Phosphorus (P) limitation in the majority of world soils is a major constraint for plant growth and crop productivity. RNA sequencing was used to discover novel P-responsive gene transcripts (PRGTs) in leaves and roots of Arabidopsis. Hisat StringTie and the Cufflinks TopHat transcript assembler were used to analyze reads and identify 1074 PRGTs with a >5-fold altered abundance during P limitation. Interestingly, 60% of these transcripts were not previously reported. Among the novel PRGTs, 106 were from unannotated genes, and some were among the most P-responsive, including At2g36727 which encodes a novel miRNA. Annotated novel PRGTs encode transcription factors, miRNAs, small signaling peptides, long non-coding RNAs, defense-related proteins, and transporters, along with proteins involved in many biological processes. We identified several genes that undergo alternative splicing during P limitation, including a novel miR399-resistant splice variant of PHOSPHATE2 (PHO2.2). Several novel P-responsive genes were regulated by PHOSPHATE STARVATION RESPONSE1 (PHR1), PHR1-LIKE 1 (PHL1), and PHO2. We discovered that P-limited plants show increased resistance to pathogens and drought stress mediated by PHR1-PHL1. Identification of novel P-responsive transcripts and the discovery of the influence of P limitation on biotic and abiotic stress adds a significant component to our understanding of plant P signaling.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Fósforo/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Fosfatos/metabolismo , Plantas/metabolismo , Regulación de la Expresión Génica de las Plantas
7.
Physiol Plant ; 175(5): e14008, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37882269

RESUMEN

Stomata are crucial for gas exchange and water evaporation, and environmental stimuli influence their density (SD) and size (SS). Although genes and mechanisms underlying stomatal development have been elucidated, stress-responsive regulators of SD and SS are less well-known. Previous studies have shown that the stress-inducible Brachypodium RFS (REGULATOR OF FLOWERING AND STRESS, BdRFS) gene affects heading time and enhances drought tolerance by reducing leaf water loss. Here, we report that overexpression lines (OXs) of BdRFS have reduced SD and increased SS, regardless of soil water status. Furthermore, biomass and plant water content of OXs were significantly increased compared to wild type. CRISPR/Cas9-mediated BdRFS knockout mutant (KO) exhibited the opposite stomatal characteristics and biomass changes. Reverse transcription-quantitative polymerase chain reaction analysis revealed that expression of BdICE1 was reversely altered in OXs and KO, pointing to a potential cause for the observed changes in stomatal phenotypes. Stomatal and transcriptional changes were not observed in the Arabidopsis rfs double mutant. Taken together, RFS is a novel regulator of SD and SS and is a promising candidate for genetic engineering of climate-resilient crops.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Brachypodium , Brachypodium/genética , Brachypodium/metabolismo , Estomas de Plantas/genética , Estomas de Plantas/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Plantas Modificadas Genéticamente/genética , Agua/metabolismo , Sequías , Estrés Fisiológico/genética , Regulación de la Expresión Génica de las Plantas
8.
New Phytol ; 233(3): 1153-1171, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34775627

RESUMEN

Root hairs (RHs) function in nutrient and water acquisition, root metabolite exudation, soil anchorage and plant-microbe interactions. Longer or more abundant RHs are potential breeding traits for developing crops that are more resource-use efficient and can improve soil health. While many genes are known to promote RH elongation, relatively little is known about genes and mechanisms that constrain RH growth. Here we demonstrate that a DOMAIN OF UNKNOWN FUNCTION 506 (DUF506) protein, AT3G25240, negatively regulates Arabidopsis thaliana RH growth. The AT3G25240 gene is strongly and specifically induced during phosphorus (P)-limitation. Mutants of this gene, which we call REPRESSOR OF EXCESSIVE ROOT HAIR ELONGATION 1 (RXR1), have much longer RHs, higher phosphate content and seedling biomass, while overexpression of the gene exhibits opposite phenotypes. Co-immunoprecipitation, pull-down and bimolecular fluorescence complementation (BiFC) analyses reveal that RXR1 physically interacts with a RabD2c GTPase in nucleus, and a rabd2c mutant phenocopies the rxr1 mutant. Furthermore, N-terminal variable region of RXR1 is crucial for inhibiting RH growth. Overexpression of a Brachypodium distachyon RXR1 homolog results in repression of RH elongation in Brachypodium. Taken together, our results reveal a novel DUF506-GTPase module with a prominent role in repression of plant RH elongation especially under P stress.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Regulación de la Expresión Génica de las Plantas , Fósforo/metabolismo , Raíces de Plantas/metabolismo
9.
Plant Cell Environ ; 45(6): 1796-1812, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35312071

RESUMEN

Domain of Unknown Function 506 proteins are ubiquitous in plants. The phosphorus (P) stress-inducible REPRESSOR OF EXCESSIVE ROOT HAIR GROWTH1 (AtRXR1) gene encodes the first characterized DUF506. AtRXR1 inhibits root hair elongation by interacting with RabD2c GTPase. However, functions of other P-responsive DUF506 genes are still missing. Here, we selected two additional P-inducible DUF506 genes for further investigation. The expression of both genes was induced by auxin. Under P-stress, At3g07350 gene expressed ubiquitously in seedlings, whereas At1g62420 (AtRXR3) expression was strongest in roots. AtRXR3 overexpressors and knockouts had shorter and longer root hairs, respectively. A functional AtRXR3-green fluorescent protein fusion localized to root epidermal cells. Chromatin immunoprecipitation and quantitative reverse-transcriptase-polymerase chain reaction revealed that AtRXR3 was transcriptionally activated by RSL4. Bimolecular fluorescence complementation and calmodulin (CaM)-binding assays showed that AtRXR3 interacted with CaM in the presence of Ca2+ . Moreover, cytosolic Ca2+ ([Ca2+ ]cyt ) oscillations in root hairs of rxr3 mutants exhibited elevated frequencies and dampened amplitudes compared to those of wild type. Thus, AtRXR3 is another DUF506 protein that attenuates P-limitation-induced root hair growth through mechanisms that involve RSL4 and interaction with CaM to modulate tip-focused [Ca2+ ]cyt oscillations.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Señalización del Calcio , Calmodulina/genética , Calmodulina/metabolismo , Regulación de la Expresión Génica de las Plantas , Raíces de Plantas/metabolismo
10.
Ann Neurol ; 90(3): 506-511, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34324214

RESUMEN

The global SARS-CoV-2 pandemic has contributed to more than 163 million confirmed infections and 3.3 million deaths worldwide. The severity of the pandemic has led to an unprecedented effort to develop multiple effective vaccines. Due to excellent safety and efficacy data from clinical trials, several vaccines were approved. We report a case series of postvaccinal encephalitis in temporal correlation to vaccination with ChAdOx1 nCov-19. The diagnostic criteria for possible autoimmune encephalitis were fulfilled. Our patients responded well to immunosuppressive therapy with corticosteroids. The incidence has been estimated to be approximately 8 per 10 million vaccine doses. Complication of postvaccinal encephalitis after ChAdOx1 nCoV-19 vaccination still appear to be very rare, but need to be diagnosed and treated adequately. Large pooled data from observational epidemiologic studies are necessary to verify causality. ANN NEUROL 2021;90:506-511.


Asunto(s)
Vacunas contra la COVID-19/efectos adversos , COVID-19/prevención & control , Encefalomielitis Aguda Diseminada/inducido químicamente , Encefalomielitis Aguda Diseminada/diagnóstico por imagen , ChAdOx1 nCoV-19 , Encefalomielitis Aguda Diseminada/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
11.
J Neuropsychiatry Clin Neurosci ; 34(3): 261-267, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35040661

RESUMEN

OBJECTIVE: The authors investigated for presence of cognitive impairment after occurrence of bilateral lesions of the genu of the internal capsule (GIC). Clinical and neuropsychological features of unilateral GIC lesions have previously been studied, but the cognitive profile of bilateral lesions of the GIC has not been fully explored. METHODS: An investigation was conducted of neurocognitive deficits and computerized tomography MRI findings among 4,200 stroke patients with bilateral GIC involvement who were admitted to the hospital between January 2010 and October 2018. RESULTS: Eight patients with bilateral lesions of the capsular genu were identified and their data analyzed. Overall, behavioral and cognitive dysfunction were characterized by impairment of frontal, memory, and executive functions. Attention and abstraction were present among all eight patients (100%); apathy, abulia, and executive dysfunctions, among seven (87.5%); global mental dysfunction and planning deficits, among six (75.0%); short-term verbal memory deficits and language dysfunctions, among five (62.5%); long-term verbal memory deficits, among four (50.0%); and spatial memory deficits, reading, writing, counting dysfunctions, and anarthria, among two (25.0%). Four of the patients (50.0%) without a history of cognitive disorder showed severe mental deterioration compatible with the clinical picture of dementia. A clinical picture of dementia was still present in these patients 6 months after stroke. CONCLUSIONS: Bilateral lesions of the capsular genu appearing either simultaneously or at different times were significantly associated with executive dysfunctions.


Asunto(s)
Disfunción Cognitiva , Demencia , Accidente Cerebrovascular , Disfunción Cognitiva/etiología , Humanos , Trastornos de la Memoria , Pruebas Neuropsicológicas , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/diagnóstico por imagen
12.
Plant Physiol ; 183(1): 399-413, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32079733

RESUMEN

A growing number of small secreted peptides (SSPs) in plants are recognized as important regulatory molecules with roles in processes such as growth, development, reproduction, stress tolerance, and pathogen defense. Recent discoveries further implicate SSPs in regulating root nodule development, which is of particular significance for legumes. SSP-coding genes are frequently overlooked, because genome annotation pipelines generally ignore small open reading frames, which are those most likely to encode SSPs. Also, SSP-coding small open reading frames are often expressed at low levels or only under specific conditions, and thus are underrepresented in non-tissue-targeted or non-condition-optimized RNA-sequencing projects. We previously identified 4,439 SSP-encoding genes in the model legume Medicago truncatula To support systematic characterization and annotation of these putative SSP-encoding genes, we developed the M. truncatula Small Secreted Peptide Database (MtSSPdb; https://mtsspdb.noble.org/). MtSSPdb currently hosts (1) a compendium of M. truncatula SSP candidates with putative function and family annotations; (2) a large-scale M. truncatula RNA-sequencing-based gene expression atlas integrated with various analytical tools, including differential expression, coexpression, and pathway enrichment analyses; (3) an online plant SSP prediction tool capable of analyzing protein sequences at the genome scale using the same protocol as for the identification of SSP genes; and (4) information about a library of synthetic peptides and root and nodule phenotyping data from synthetic peptide screens in planta. These datasets and analytical tools make MtSSPdb a unique and valuable resource for the plant research community. MtSSPdb also has the potential to become the most complete database of SSPs in plants.


Asunto(s)
Medicago truncatula/genética , Péptidos/metabolismo , Proteínas de Plantas/metabolismo , Bases de Datos Factuales , Genoma de Planta/genética , Péptidos/genética , Proteínas de Plantas/genética
13.
Plant Cell Environ ; 44(1): 186-202, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32822068

RESUMEN

Knowing how switchgrass (Panicum virgatum L.) responds and adapts to phosphorus (P)-limitation will aid efforts to optimize P acquisition and use in this species for sustainable biomass production. This integrative study investigated the impacts of mild, moderate, and severe P-stress on genome transcription and whole-plant metabolism, physiology and development in switchgrass. P-limitation reduced overall plant growth, increased root/shoot ratio, increased root branching at moderate P-stress, and decreased root diameter with increased density and length of root hairs at severe P-stress. RNA-seq analysis revealed thousands of genes that were differentially expressed under moderate and severe P-stress in roots and/or shoots compared to P-replete plants, with many stress-induced genes involved in transcriptional and other forms of regulation, primary and secondary metabolism, transport, and other processes involved in P-acquisition and homeostasis. Amongst the latter were multiple miRNA399 genes and putative targets of these. Metabolite profiling showed that levels of most sugars and sugar alcohols decreased with increasing P stress, while organic and amino acids increased under mild and moderate P-stress in shoots and roots, although this trend reversed under severe P-stress, especially in shoots.


Asunto(s)
Panicum/metabolismo , Fósforo/deficiencia , Perfilación de la Expresión Génica , Registros Médicos , MicroARNs/metabolismo , Panicum/crecimiento & desarrollo , Panicum/fisiología , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Brotes de la Planta/crecimiento & desarrollo , Brotes de la Planta/metabolismo , ARN Largo no Codificante/metabolismo , ARN de Planta/metabolismo , Estrés Fisiológico
14.
Ann Neurol ; 87(1): 40-51, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31714631

RESUMEN

OBJECTIVE: To analyze why numerous acute stroke treatments were successful in the laboratory but failed in large clinical trials. METHODS: We searched all phase 3 trials of medical treatments for acute ischemic stroke and corresponding early clinical and experimental studies. We compared the overall efficacy and assessed the impact of publication bias and study design on the efficacy. Furthermore, we estimated power and true report probability of experimental studies. RESULTS: We identified 50 phase 3 trials with 46,008 subjects, 75 early clinical trials with 12,391 subjects, and 209 experimental studies with >7,141 subjects. Three (6%) phase 3, 24 (32%) early clinical, and 143 (69.08%) experimental studies were positive. The mean treatment effect was 0.76 (95% confidence interval [CI] = 0.70-0.83) in experimental studies, 0.87 (95% CI = 0.71-1.06) in early clinical trials, and 1.00 (95% CI = 0.95-1.06) in phase 3 trials. Funnel plot asymmetry and trim-and-fill revealed a clear publication bias in experimental studies and early clinical trials. Study design and adherence to quality criteria had a considerable impact on estimated effect sizes. The mean power of experimental studies was 17%. Assuming a bias of 30% and pre-study odds of 0.5 to 0.7, this leads to a true report probability of <50%. INTERPRETATION: Pivotal study design differences between experimental studies and clinical trials, including different primary end points and time to treatment, publication bias, neglected quality criteria and low power, contribute to the stepwise efficacy decline of stroke treatments from experimental studies to phase 3 clinical trials. Even under conservative estimates, less than half of published positive experimental stroke studies are truly positive. ANN NEUROL 2020;87:40-51.


Asunto(s)
Ensayos Clínicos como Asunto/estadística & datos numéricos , Evaluación Preclínica de Medicamentos/estadística & datos numéricos , Fármacos Neuroprotectores/uso terapéutico , Accidente Cerebrovascular/tratamiento farmacológico , Animales , Humanos , Sesgo de Publicación , Proyectos de Investigación
15.
Br J Anaesth ; 126(6): 1119-1127, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33820655

RESUMEN

BACKGROUND: Postoperative cognitive dysfunction (POCD) is an adverse outcome that impacts patients' quality of life. Its diagnosis relies on formal cognitive testing performed before and after surgery. The substantial heterogeneity in methodology limits comparability and meta-analysis of studies. This systematic review critically appraises the methodology of studies on POCD published since the 1995 Consensus Statement and aims to provide guidance to future authors by providing recommendations that may improve comparability between future studies. METHODS: This systematic review of literature published between 1995 and 2019 included studies that used baseline cognitive testing and a structured cognitive test battery, and had a minimal follow-up of 1 month. For cohorts with multiple publications, data from the primary publication were supplemented with available data from later follow-up studies. RESULTS: A total of 274 unique studies were included in the analysis. In the included studies, 259 different cognitive tests were used. Studies varied considerably in timing of assessment, follow-up duration, definition of POCD, and use of control groups. Of the 274 included studies, 70 reported POCD as a dichotomous outcome at 1 to <3 months, with a pooled incidence of 2998/10 335 patients (29.0%). CONCLUSIONS: We found an overwhelming heterogeneity in methodology used to study POCD since the publication of the 1995 Consensus Statement. Future authors could improve study quality and comparability through optimal timing of assessment, the use of commonly used cognitive tests including the Consensus Statement 'core battery', application of appropriate cut-offs and diagnostic rules, and detailed reporting of the methods used. PROSPERO REGISTRY NUMBER: CRD42016039293.


Asunto(s)
Cognición , Pruebas Neuropsicológicas , Complicaciones Cognitivas Postoperatorias/diagnóstico , Humanos , Complicaciones Cognitivas Postoperatorias/etiología , Complicaciones Cognitivas Postoperatorias/psicología , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Proyectos de Investigación , Factores de Tiempo
16.
Eur J Anaesthesiol ; 38(9): 943-956, 2021 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-33534264

RESUMEN

BACKGROUND: Anecdotally, cholinergic stimulation has been used to treat delirium and reduce cognitive dysfunction. OBJECTIVE: The aim of this investigation was to evaluate whether physostigmine reduced the incidence of postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) in patients undergoing liver resection. DESIGN: This was a double-blind, randomised, placebo-controlled trial. Between 11 August 2009 and 3 March 2016, patients were recruited at the Charité - Universitätsmedizin Berlin in Germany. Follow-ups took place at 1 week (T1), 90 days (T2) and 365 days (T3) after surgery. SETTING: This single-centre study was conducted at an academic medical centre. PARTICIPANTS: In total, 261 participants aged at least 18 years scheduled for elective liver surgery were randomised. The protocol also included 45 non-surgical matched controls to provide normative data for POCD and neurocognitive deficit (NCD). INTERVENTION: Participants were allocated to receive either intravenous physostigmine, as a bolus of 0.02 mg kg-1 body weight followed by 0.01 mg kg-1 body weight per hour (n = 130), or placebo (n = 131), for 24 h after induction of anaesthesia. MAIN OUTCOMES AND MEASURES: Primary outcomes were POD, assessed using the Diagnostic and Statistical Manual of Mental Disorders (DSM-4-TR) twice daily up to day 7 after surgery, and POCD assessed via the CANTAB neuropsychological test battery, and two paper pencil tests on the day before surgery, and on postoperative days 7, 90 and 365. RESULTS: In total, 261 patients were randomised, 130 to the physostigmine and 131 to the placebo group. The incidence of POD did not differ significantly between the physostigmine and placebo groups (20 versus 15%; P = 0.334). Preoperative cognitive impairment and POCD frequencies did not differ significantly between the physostigmine and placebo groups at any time. Lower mortality rates were found in the physostigmine group compared with placebo at 3 months [2% (95% confidence interval (CI), 0 to 4) versus 11% (95% CI, 6 to 16), P = 0.002], and 6 months [7% (95% CI, 3 to 12) versus 16% (95% CI, 10 to 23), P = 0.012] after surgery. CONCLUSION: Physostigmine had no effect on POD and POCD when applied after induction of anaesthesia up to 24 h. TRIAL REGISTRATION: DOI 10.1186/ISRCTN18978802, EudraCT 2008-007237-47, Ethics approval ZS EK 11 618/08 (15 January 2009).


Asunto(s)
Disfunción Cognitiva , Delirio , Adolescente , Adulto , Disfunción Cognitiva/epidemiología , Disfunción Cognitiva/etiología , Disfunción Cognitiva/prevención & control , Delirio/diagnóstico , Delirio/epidemiología , Delirio/prevención & control , Humanos , Hígado , Fisostigmina , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/prevención & control
17.
Plant J ; 98(1): 153-164, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30548978

RESUMEN

Cell-, tissue- or organ-specific inducible expression systems are powerful tools for functional analysis of changes to the pattern, level or timing of gene expression. However, plant researchers lack standardised reagents that promote reproducibility across the community. Here, we report the development and functional testing of a Gateway-based system for quantitatively, spatially and temporally controlling inducible gene expression in Arabidopsis that overcomes several drawbacks of the legacy systems. We used this modular driver/effector system with intrinsic reporting of spatio-temporal promoter activity to generate 18 well-characterised homozygous transformed lines showing the expected expression patterns specific for the major cell types of the Arabidopsis root; seed and plasmid vectors are available through the Arabidopsis stock centre. The system's tight regulation was validated by assessing the effects of diphtheria toxin A chain expression. We assessed the utility of Production of Anthocyanin Pigment 1 (PAP1) as an encoded effector mediating cell-autonomous marks. With this shared resource of characterised reference driver lines, which can be expanded with additional promoters and the use of other fluorescent proteins, we aim to contribute towards enhancing reproducibility of qualitative and quantitative analyses.


Asunto(s)
Arabidopsis/genética , Genes Reporteros , Antocianinas/metabolismo , Arabidopsis/citología , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Estradiol/metabolismo , Regulación de la Expresión Génica de las Plantas , Especificidad de Órganos , Raíces de Plantas/citología , Raíces de Plantas/genética , Raíces de Plantas/metabolismo , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas/genética , Reproducibilidad de los Resultados , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
18.
Stroke ; 51(6): 1758-1765, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32404035

RESUMEN

Background and Purpose- The RE-SPECT ESUS trial (Randomized, Double-Blind, Evaluation in Secondary Stroke Prevention Comparing the Efficacy and Safety of the Oral Thrombin Inhibitor Dabigatran Etexilate Versus Acetylsalicylic Acid in Patients With Embolic Stroke of Undetermined Source) tested the hypothesis that dabigatran would be superior to aspirin for the prevention of recurrent stroke in patients with embolic stroke of undetermined source. This exploratory subgroup analysis investigates the impact of age, renal function (both predefined), and dabigatran dose (post hoc) on the rates of recurrent stroke and major bleeding. Methods- RE-SPECT ESUS was a multicenter, randomized, double-blind trial of dabigatran 150 or 110 mg (for patients aged ≥75 years and/or with creatinine clearance 30 to <50 mL/minute) twice daily compared with aspirin 100 mg once daily. The primary outcome was recurrent stroke. Results- The trial, which enrolled 5390 patients from December 2014 to January 2018, did not demonstrate superiority of dabigatran versus aspirin for prevention of recurrent stroke in patients with embolic stroke of undetermined source. However, among the population qualifying for the lower dabigatran dose, the rate of recurrent stroke was reduced with dabigatran versus aspirin (7.4% versus 13.0%; hazard ratio, 0.57 [95% CI, 0.39-0.82]; interaction P=0.01). This was driven mainly by the subgroup aged ≥75 years (7.8% versus 12.4%; hazard ratio, 0.63 [95% CI, 0.43-0.94]; interaction P=0.10). Stroke rates tended to be lower with dabigatran versus aspirin with declining renal function. Risks for major bleeding were similar between treatments, irrespective of renal function, but with a trend for lower bleeding rates with dabigatran versus aspirin in older patients. Conclusions- In subgroup analyses of RE-SPECT ESUS, dabigatran reduced the rate of recurrent stroke compared with aspirin in patients qualifying for the lower dose of dabigatran. These results are hypothesis-generating. Aspirin remains the standard antithrombotic treatment for patients with embolic stroke of undetermined source. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT02239120.


Asunto(s)
Aspirina , Dabigatrán , Fibrinolíticos , Embolia Intracraneal , Enfermedades Renales , Accidente Cerebrovascular , Anciano , Anciano de 80 o más Años , Aspirina/administración & dosificación , Aspirina/farmacocinética , Dabigatrán/administración & dosificación , Dabigatrán/farmacocinética , Método Doble Ciego , Femenino , Fibrinolíticos/administración & dosificación , Fibrinolíticos/farmacocinética , Humanos , Embolia Intracraneal/sangre , Embolia Intracraneal/tratamiento farmacológico , Enfermedades Renales/sangre , Enfermedades Renales/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Recurrencia , Accidente Cerebrovascular/sangre , Accidente Cerebrovascular/tratamiento farmacológico
19.
Cerebrovasc Dis ; 49(6): 647-655, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33207338

RESUMEN

BACKGROUND: Detection of atrial fibrillation (AF) is one of the primary diagnostic goals for patients on a stroke unit. Physician-based manual analysis of continuous ECG monitoring is regarded as the gold standard for AF detection but requires considerable resources. Recently, automated computer-based analysis of RR intervals was established to simplify AF detection. The present prospective study analyzes both methods head to head regarding AF detection specificity, sensitivity, and overall effectiveness. METHODS: Consecutive stroke patients without history of AF or proof of AF in the admission ECG were enrolled over the period of 7 months. All patients received continuous ECG telemetry during the complete stay on the stroke unit. All ECGs underwent automated analysis by a commercially available program. Blinded to these results, all ECG tracings were also assessed manually. Sensitivity, specificity, time consumption, costs per day, and cost-effectiveness were compared. RESULTS: 216 consecutive patients were enrolled (70.7 ± 14.1 years, 56% male) and 555 analysis days compared. AF was detected by manual ECG analysis on 37 days (6.7%) and automatically on 57 days (10.3%). Specificity of the automated algorithm was 94.6% and sensitivity 78.4% (28 [5.0%] false positive and 8 [1.4%] false negative). Patients with AF were older and had more often arterial hypertension, higher NIHSS at admission, more often left atrial dilatation, and a higher CHA2DS2-VASc score. Automation significantly reduced human resources but was more expensive compared to manual analysis alone. CONCLUSION: Automatic AF detection is highly specific, but sensitivity is relatively low. Results of this study suggest that automated computer-based AF detection should be rather complementary to manual ECG analysis than replacing it.


Asunto(s)
Algoritmos , Fibrilación Atrial/diagnóstico , Electrocardiografía , Sistema de Conducción Cardíaco/fisiopatología , Frecuencia Cardíaca , Hospitalización , Procesamiento de Señales Asistido por Computador , Accidente Cerebrovascular/etiología , Telemetría , Potenciales de Acción , Adulto , Anciano , Anciano de 80 o más Años , Fibrilación Atrial/complicaciones , Fibrilación Atrial/fisiopatología , Automatización , Femenino , Alemania , Humanos , Pacientes Internos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Reproducibilidad de los Resultados , Factores de Riesgo , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/fisiopatología , Adulto Joven
20.
J Stroke Cerebrovasc Dis ; 29(11): 105207, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33066934

RESUMEN

BACKGROUND: Cervical artery dissection is an important cause of stroke in the young. The etiology is still discussed controversial. The most obvious reason for a dissection of extracranial arteries is due to a trauma, eg. after car accidents or other high speed traumas such as high-velocity road traffic accidents. Besides these clear cases, chiropractic neck maneuvers represent potential reasons for vessel injuries. CASE PRESENTATION: We here report a rare case of secondary cervical artery dissection after so-called cupping therapy and a preventive treatment with a direct oral anticoagulant. CONCLUSIONS: Therapists using this technique should be aware of the potentially devastating side effects. The diagnosis of ICA dissection should be considered with any new onset of unknown neck pain or headache, specifically in combination with neurological deficits.


Asunto(s)
Disección de la Arteria Carótida Interna/etiología , Ventosaterapia/efectos adversos , Ataque Isquémico Transitorio/etiología , Administración Oral , Anticoagulantes/administración & dosificación , Disección de la Arteria Carótida Interna/diagnóstico por imagen , Disección de la Arteria Carótida Interna/tratamiento farmacológico , Sustitución de Medicamentos , Humanos , Ataque Isquémico Transitorio/diagnóstico por imagen , Ataque Isquémico Transitorio/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Inhibidores de Agregación Plaquetaria/administración & dosificación , Presión , Recurrencia , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda