Safety and efficacy of tenecteplase in patients with wake-up stroke assessed by non-contrast CT (TWIST): a multicentre, open-label, randomised controlled trial

BACKGROUND

Current evidence supports the use of intravenous thrombolysis with alteplase in patients with wake-up stroke selected with MRI or perfusion imaging and is recommended in clinical guidelines. However, access to advanced imaging techniques is often scarce. We aimed to determine whether thrombolytic treatment with intravenous tenecteplase given within 4·5 h of awakening improves functional outcome in patients with ischaemic wake-up stroke selected using non-contrast CT.

METHODS

TWIST was an investigator-initiated, multicentre, open-label, randomised controlled trial with blinded endpoint assessment, conducted at 77 hospitals in ten countries. We included patients aged 18 years or older with acute ischaemic stroke symptoms upon awakening, limb weakness, a National Institutes of Health Stroke Scale (NIHSS) score of 3 or higher or aphasia, a non-contrast CT examination of the head, and the ability to receive tenecteplase within 4·5 h of awakening. Patients were randomly assigned (1:1) to either a single intravenous bolus of tenecteplase 0·25 mg per kg of bodyweight (maximum 25 mg) or control (no thrombolysis) using a central, web-based, computer-generated randomisation schedule. Trained research personnel, who conducted telephone interviews at 90 days (follow-up), were masked to treatment allocation. Clinical assessments were performed on day 1 (at baseline) and day 7 of hospital admission (or at discharge, whichever occurred first). The primary outcome was functional outcome assessed by the modified Rankin Scale (mRS) at 90 days and analysed using ordinal logistic regression in the intention-to-treat population. This trial is registered with EudraCT (2014-000096-80), ClinicalTrials.gov (NCT03181360), and ISRCTN (10601890).

FINDINGS

From June 12, 2017, to Sept 30, 2021, 578 of the required 600 patients were enrolled (288 randomly assigned to the tenecteplase group and 290 to the control group [intention-to-treat population]). The median age of participants was 73·7 years (IQR 65·9-81·1). 332 (57%) of 578 participants were male and 246 (43%) were female. Treatment with tenecteplase was not associated with better functional outcome, according to mRS score at 90 days (adjusted OR 1·18, 95% CI 0·88-1·58; p=0·27). Mortality at 90 days did not significantly differ between treatment groups (28 [10%] patients in the tenecteplase group and 23 [8%] in the control group; adjusted HR 1·29, 95% CI 0·74-2·26; p=0·37). Symptomatic intracranial haemorrhage occurred in six (2%) patients in the tenecteplase group versus three (1%) in the control group (adjusted OR 2·17, 95% CI 0·53-8·87; p=0·28), whereas any intracranial haemorrhage occurred in 33 (11%) versus 30 (10%) patients (adjusted OR 1·14, 0·67-1·94; p=0·64).

INTERPRETATION

In patients with wake-up stroke selected with non-contrast CT, treatment with tenecteplase was not associated with better functional outcome at 90 days. The number of symptomatic haemorrhages and any intracranial haemorrhages in both treatment groups was similar to findings from previous trials of wake-up stroke patients selected using advanced imaging. Current evidence does not support treatment with tenecteplase in patients selected with non-contrast CT.

FUNDING

Norwegian Clinical Research Therapy in the Specialist Health Services Programme, the Swiss Heart Foundation, the British Heart Foundation, and the Norwegian National Association for Public Health.

The impact of LuxF on light intensity in bacterial bioluminescence

The enzymes involved in bacterial bioluminescence are encoded in the lux operon with a conserved gene order of luxCDABEG. Some photobacterial strains carry an additional gene, termed luxF, which produces the LuxF protein, whose function and influence on bacterial bioluminescence is still uncertain. The LuxF protein binds the flavin derivative 6-(3'-(R)-myristyl)-flavin mononucleotide (myrFMN), which is generated as a side product in the luciferase-catalyzed reaction. This study utilized an Escherichia coli (E. coli) based lux operon expression system where the lux operons of Photobacterium leiognathi subsp. mandapamensis 27561 or of Photobacterium leiognathi subsp. leiognathi 25521, namely luxCDAB(F)EG, were cloned into a single expression vector. Exclusion of luxF gene from the lux operon enabled novel insights into the role of LuxF protein in light emission. E. coli cultures harboring and expressing the genes of the lux operon including luxF gene emit more light than without luxF gene. Furthermore, isolation of the tightly bound flavin derivative revealed the presence of at least three different flavin derivatives. Analysis by UV/Vis absorption and NMR spectroscopy as well as mass spectrometry showed that the flavin derivatives bear fatty acids of various chain lengths. This distribution of FMN derivatives is vastly different to what was found in bioluminescent bacteria and indicates that the luciferase is supplied with a range of aldehyde substrates in E. coli.

Oxidative cyclization of N-methyl-dopa by a fungal flavoenzyme of the amine oxidase family

Flavin-dependent enzymes catalyze many oxidations, including formation of ring structures in natural products. The gene cluster for biosynthesis of fumisoquins, secondary metabolites structurally related to isoquinolines, in the filamentous fungus Aspergillus fumigatus harbors a gene that encodes a flavoprotein of the amine oxidase family, termed fsqB (fumisoquin biosynthesis gene B). This enzyme catalyzes an oxidative ring closure reaction that leads to the formation of isoquinoline products. This reaction is reminiscent of the oxidative cyclization reported for berberine bridge enzyme and tetrahydrocannabinol synthase. Despite these similarities, amine oxidases and berberine bridge enzyme–like enzymes possess distinct structural properties, prompting us to investigate the structure–function relationships of FsqB. Here, we report the recombinant production and purification of FsqB, elucidation of its crystal structure, and kinetic analysis employing five putative substrates. The crystal structure at 2.6 Å resolution revealed that FsqB is a member of the amine oxidase family with a covalently bound FAD cofactor. N-methyl-dopa was the best substrate for FsqB and was completely converted to the cyclic isoquinoline product. The absence of the meta-hydroxyl group, as e.g. in l-N-methyl-tyrosine, resulted in a 25-fold lower rate of reduction and the formation of the demethylated product l-tyrosine, instead of a cyclic product. Surprisingly, FsqB did not accept the d-stereoisomer of N-methyltyrosine, in contrast to N-methyl-dopa, for which both stereoisomers were oxidized with similar rates. On the basis of the crystal structure and docking calculations, we postulate a substrate-dependent population of distinct binding modes that rationalizes stereospecific oxidation in the FsqB active site.

In Situ Measurement and Correlation of Cell Density and Light Emission of Bioluminescent Bacteria

There is a considerable number of bacterial species capable of emitting light. All of them share the same gene cluster, namely the lux operon. Despite this similarity, these bacteria show extreme variations in characteristics like growth behavior, intensity of light emission or regulation of bioluminescence. The method presented here is a newly developed assay that combines recording of cell growth and bioluminescent light emission intensity over time utilizing a plate reader. The resulting growth and light emission characteristics can be linked to important features of the respective bacterial strain, such as quorum sensing regulation. The cultivation of a range of bioluminescent bacteria requires a specific medium (e.g., artificial sea water medium) and defined temperatures. The easy to handle, non-bioluminescent standard-research bacterium Escherichia coli (E. coli), on the other hand, can be cultivated inexpensively in high quantities in laboratory scale. Exploiting E. coli by introducing a plasmid containing the whole lux operon can simplify experimental conditions and additionally opens up many possibilities for future applications. The expression of all lux genes utilizing an E. coli expression strain was achieved by construction of an expression plasmid via Gibson cloning and insertion of four fragments containing seven lux genes and three rib genes of the lux-rib operon into a pET28a vector. E. coli based lux gene expression can be induced and controlled via Isopropyl-β-D-thiogalactopyranosid (IPTG) addition resulting in bioluminescent E. coli cells. The advantages of this system are to avoid quorum sensing regulation restrictions and complex medium compositions along with non-standard growth conditions, such as defined temperatures. This system enables analysis of lux genes and their interplay, by the exclusion of the respective gene from the lux operon, or even addition of novel genes, exchanging the luxAB genes from one bacterial strain by another, or analyzing protein complexes, such as luxCDE.

The single berberine bridge enzyme homolog of Physcomitrella patens is a cellobiose oxidase

The berberine bridge enzyme from the California poppy Eschscholzia californica (EcBBE) catalyzes the oxidative cyclization of (S)‐reticuline to (S)‐scoulerine, that is, the formation of the berberine bridge in the biosynthesis of benzylisoquinoline alkaloids. Interestingly, a large number of BBE‐like genes have been identified in plants that lack alkaloid biosynthesis. This finding raised the question of the primordial role of BBE in the plant kingdom, which prompted us to investigate the closest relative of EcBBE in Physcomitrella patens (PpBBE1), the most basal plant harboring a BBE‐like gene. Here, we report the biochemical, structural, and in vivo characterization of PpBBE1. Our studies revealed that PpBBE1 is structurally and biochemically very similar to EcBBE. In contrast to EcBBE, we found that PpBBE1 catalyzes the oxidation of the disaccharide cellobiose to the corresponding lactone, that is, PpBBE1 is a cellobiose oxidase. The enzymatic reaction mechanism was characterized by a structure‐guided mutagenesis approach that enabled us to assign a catalytic role to amino acid residues in the active site of PpBBE1. In vivo experiments revealed the highest level of PpBBE1 expression in chloronema, the earliest stage of the plant's life cycle, where carbon metabolism is strongly upregulated. It was also shown that the enzyme is secreted to the extracellular space, where it may be involved in later steps of cellulose degradation, thereby allowing the moss to make use of cellulose for energy production. Overall, our results suggest that the primordial role of BBE‐like enzymes in plants revolved around primary metabolic reactions in carbohydrate utilization.

Database

Structural data are available in the PDB under the accession numbers 6EO4 and 6EO5.

An uncommon complication of Listeria monocytogenes infection: Polyradiculoneuritis following Listeria meningoencephalitis

Listeria monocytogenes, primarily a foodborne pathogen, is commonly responsible for disorders affecting the central nervous system and cranial nerves. We hereby present the first case to our knowledge of listeriosis linked to a peripheral neurological disorder causing acute upper limb weakness.

Evaluation of the RumiWatchSystem for measuring grazing behaviour of cows

Feeding behaviour is an important parameter of animal performance, health and welfare, as well as reflecting levels and quality of feed available. Previously, sensors were only used for measuring animal feeding behaviour in indoor housing systems. However, sensors such as the RumiWatchSystem can also monitor such behaviour continuously in pasture-based environments. Therefore, the aim of this study was to validate the RumiWatchSystem to record cow activity and feeding behaviour in a pasture-based system. The RumiWatchSystem was evaluated against visual observation across two different experiments. The time duration per hour at grazing, rumination, walking, standing and lying recorded by the RumiWatchSystem was compared to the visual observation data in Experiment 1. Concordance Correlation Coefficient (CCC) values of CCC=0.96 for grazing, CCC=0.99 for rumination, CCC=1.00 for standing and lying and CCC=0.92 for walking were obtained. The number of grazing and rumination bouts within one hour were also analysed resulting in Cohen's Kappa (κ)=0.62 and κ=0.86 for grazing and rumination bouts, respectively. Experiment 2 focused on the validation of grazing bites and rumination chews. The accordance between visual observation and automated measurement by the RumiWatchSystem was high with CCC=0.78 and CCC=0.94 for grazing bites and rumination chews, respectively. These results indicate that the RumiWatchSystem is a reliable sensor technology for observing cow activity and feeding behaviour in a pasture based milk production system, and may be used for research purposes in a grazing environment.

Ribosomal protein S3 interacts with the NF-κB inhibitor IκBα

Ribosomal protein S3 (RPS3) is part of nuclear, transcriptionally active and cytoplasmic inhibitory complexes containing NF-κB variant p65. We show that in resting HEK293 cells, RPS3 interacts with NF-κB inhibitor IκBα. In contrast, efficient co-precipitation of p65 with RPS3 was only achieved in the presence of ectopic IκBα. In addition, a strong in vitro interaction was observed between RPS3 and IκBα, while binding between RPS3 and p65 was very weak. Furthermore, IκBα facilitated the reconstitution of p65 and RPS3 into one complex in vitro. Our results suggest that IκBα sequesters not only p65 but also RPS3 in the cytoplasm. This would ensure maintenance of an RPS3 pool for the NF-κB pathway as well as equimolar release of RPS3 and p65 upon stimulation.

Yar1 protects the ribosomal protein Rps3 from aggregation

2000 ribosomes have to be synthesized in yeast every minute. Therefore the fast production of ribosomal proteins, their efficient delivery to the nucleus and correct incorporation into ribosomal subunits are prerequisites for optimal growth rates. Here, we report that the ankyrin repeat protein Yar1 directly interacts with the small ribosomal subunit protein Rps3 and accompanies newly synthesized Rps3 from the cytoplasm into the nucleus where Rps3 is assembled into pre-ribosomal subunits. A yar1 deletion strain displays a similar phenotype as an rps3 mutant strain, showing an accumulation of 20S pre-rRNA and a 40S export defect. The combination of an rps3 mutation with a yar1 deletion leads to an enhancement of these phenotypes, while increased expression of RPS3 suppresses the defects of a yar1 deletion strain. We further show that Yar1 protects Rps3 from aggregation in vitro and increases its solubility in vivo. Our data suggest that Yar1 is a specific chaperone for Rps3, which serves to keep Rps3 soluble until its incorporation into the pre-ribosome.

[Therapeutic advances in neurology]

The neurology field has been greatly improved in 2008. The therapeutic window of intravenous thrombolysis for acute ischemic stoke is extended to 4 h 30. New studies show that the clinical progression of Parkinson's disease might be slowed by some medication. Deep brain stimulation may be beneficial early in the course of the disease. Tysabri and Fingolimod in multiple sclerosis are discussed. The pharmacopoeia for epilepsy is in constant development with new products recently released in Switzerland. CGRP receptor antagonists are about to be launched as a promising acute migraine treatment. The pharmacological approach in amyotrophic lateral sclerosis patients might be improved according to research results.