Prehospital transdermal glyceryl trinitrate in patients with ultra-acute presumed stroke (RIGHT-2): an ambulance-based, randomised, sham-controlled, blinded, phase 3 trial

Background: High blood pressure is common in acute stroke and is a predictor of poor outcome; however, large trials of lowering blood pressure have given variable results, and the management of high blood pressure in ultra-acute stroke remains unclear. We investigated whether transdermal glyceryl trinitrate (GTN; also known as nitroglycerin), a nitric oxide donor, might improve outcome when administered very early after stroke onset. Methods: We did a multicentre, paramedic-delivered, ambulance-based, prospective, randomised, sham-controlled, blinded-endpoint, phase 3 trial in adults with presumed stroke within 4 h of onset, face-arm-speech-time score of 2 or 3, and systolic blood pressure 120 mm Hg or higher. Participants were randomly assigned (1:1) to receive transdermal GTN (5 mg once daily for 4 days; the GTN group) or a similar sham dressing (the sham group) in UK-based ambulances by paramedics, with treatment continued in hospital. Paramedics were unmasked to treatment, whereas participants were masked. The primary outcome was the 7-level modified Rankin Scale (mRS; a measure of functional outcome) at 90 days, assessed by central telephone follow-up with masking to treatment. Analysis was hierarchical, first in participants with a confirmed stroke or transient ischaemic attack (cohort 1), and then in all participants who were randomly assigned (intention to treat, cohort 2) according to the statistical analysis plan. This trial is registered with ISRCTN, number ISRCTN26986053. Findings: Between Oct 22, 2015, and May 23, 2018, 516 paramedics from eight UK ambulance services recruited 1149 participants (n=568 in the GTN group, n=581 in the sham group). The median time to randomisation was 71 min (IQR 45–116). 597 (52%) patients had ischaemic stroke, 145 (13%) had intracerebral haemorrhage, 109 (9%) had transient ischaemic attack, and 297 (26%) had a non-stroke mimic at the final diagnosis of the index event. In the GTN group, participants' systolic blood pressure was lowered by 5·8 mm Hg compared with the sham group (p<0·0001), and diastolic blood pressure was lowered by 2·6 mm Hg (p=0·0026) at hospital admission. We found no difference in mRS between the groups in participants with a final diagnosis of stroke or transient ischaemic stroke (cohort 1): 3 (IQR 2–5; n=420) in the GTN group versus 3 (2–5; n=408) in the sham group, adjusted common odds ratio for poor outcome 1·25 (95% CI 0·97–1·60; p=0·083); we also found no difference in mRS between all patients (cohort 2: 3 [2–5]; n=544, in the GTN group vs 3 [2–5]; n=558, in the sham group; 1·04 [0·84–1·29]; p=0·69). We found no difference in secondary outcomes, death (treatment-related deaths: 36 in the GTN group vs 23 in the sham group [p=0·091]), or serious adverse events (188 in the GTN group vs 170 in the sham group [p=0·16]) between treatment groups. Interpretation: Prehospital treatment with transdermal GTN does not seem to improve functional outcome in patients with presumed stroke. It is feasible for UK paramedics to obtain consent and treat patients with stroke in the ultra-acute prehospital setting

Expression of P. falciparum var Genes Involves Exchange of the Histone Variant H2A.Z at the Promoter

Plasmodium falciparum employs antigenic variation to evade the human immune response by switching the expression of different variant surface antigens encoded by the var gene family. Epigenetic mechanisms including histone modifications and sub-nuclear compartmentalization contribute to transcriptional regulation in the malaria parasite, in particular to control antigenic variation. Another mechanism of epigenetic control is the exchange of canonical histones with alternative variants to generate functionally specialized chromatin domains. Here we demonstrate that the alternative histone PfH2A.Z is associated with the epigenetic regulation of var genes. In many eukaryotic organisms the histone variant H2A.Z mediates an open chromatin structure at promoters and facilitates diverse levels of regulation, including transcriptional activation. Throughout the asexual, intraerythrocytic lifecycle of P. falciparum we found that the P. falciparum ortholog of H2A.Z (PfH2A.Z) colocalizes with histone modifications that are characteristic of transcriptionally-permissive euchromatin, but not with markers of heterochromatin. Consistent with this finding, antibodies to PfH2A.Z co-precipitate the permissive modification H3K4me3. By chromatin-immunoprecipitation we show that PfH2A.Z is enriched in nucleosomes around the transcription start site (TSS) in both transcriptionally active and silent stage-specific genes. In var genes, however, PfH2A.Z is enriched at the TSS only during active transcription in ring stage parasites. Thus, in contrast to other genes, temporal var gene regulation involves histone variant exchange at promoter nucleosomes. Sir2 histone deacetylases are important for var gene silencing and their yeast ortholog antagonises H2A.Z function in subtelomeric yeast genes. In immature P. falciparum parasites lacking Sir2A or Sir2B high var transcription levels correlate with enrichment of PfH2A.Z at the TSS. As Sir2A knock out parasites mature the var genes are silenced, but PfH2A.Z remains enriched at the TSS of var genes; in contrast, PfH2A.Z is lost from the TSS of de-repressed var genes in mature Sir2B knock out parasites. This result indicates that PfH2A.Z occupancy at the active var promoter is antagonized by PfSir2A during the intraerythrocytic life cycle. We conclude that PfH2A.Z contributes to the nucleosome architecture at promoters and is regulated dynamically in active var genes

Prehospital transdermal glyceryl trinitrate for ultra-acute ischaemic stroke: data from the RIGHT-2 randomised sham-controlled ambulance trial

Background The effect of transdermal glyceryl trinitrate (GTN, a nitrovasodilator) on clinical outcome when administered before hospital admission in suspected stroke patients is unclear. Here, we assess the safety and efficacy of GTN in the prespecified subgroup of patients who had an ischaemic stroke within the Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2).Methods RIGHT-2 was an ambulance-based multicentre sham-controlled blinded-endpoint study with patients randomised within 4 hours of onset. The primary outcome was a shift in scores on the modified Rankin scale (mRS) at day 90. Secondary outcomes included death; a global analysis (Wei-Lachin test) containing Barthel Index, EuroQol-5D, mRS, telephone interview for cognitive status-modified and Zung depression scale; and neuroimaging-determined ‘brain frailty’ markers. Data were reported as n (%), mean (SD), median [IQR], adjusted common OR (acOR), mean difference or Mann-Whitney difference (MWD) with 95% CI.Results 597 of 1149 (52%) patients had a final diagnosis of ischaemic stroke; age 75 (12) years, premorbid mRS>2 107 (18%), Glasgow Coma Scale 14 (2) and time from onset to randomisation 67 [45, 108] min. Neuroimaging ‘brain frailty’ was common: median score 2 [2, 3] (range 0–3). At day 90, GTN did not influence the primary outcome (acOR for increased disability 1.15, 95% CI 0.85 to 1.54), death or global analysis (MWD 0.00, 95% CI −0.10 to 0.09). In subgroup analyses, there were non-significant interactions suggesting GTN may be associated with more death and dependency in participants randomised within 1 hour of symptom onset and in those with more severe stroke.Conclusions In patients who had an ischaemic stroke, ultra-acute administration of transdermal GTN in the ambulance did not improve clinical outcomes in a population with more clinical and radiological frailty than seen in previous in-hospital trials

Pre-hospital transdermal glyceryl trinitrate for transient ischaemic attack: data from the RIGHT-2 trial

Background: Ambulance trials assessing interventions in suspected stroke patients will recruit patients with currently active symptoms that will resolve into transient ischaemic attack (TIA). We assessed the safety and efficacy of glyceryl trinitrate (GTN) in the pre-specified subgroup of patients with TIA in the Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2).Methods: RIGHT-2 was a pre-hospital-initiated multicentre randomised sham-controlled blinded-endpoint trial that randomised patients with presumed ultra-acute stroke within 4 hours of symptom onset to transdermal GTN or sham. Final diagnosis was determined by site investigators. The primary outcome was shift in modified Rankin scale (mRS) scores at 90 days analysed using ordinal logistic regression reported as adjusted common odds ratio (cOR) with 95% confidence intervals (CI).Secondary outcomes included death or dependency (mRS >2). Results: 109 of 1149 (9.5%) patients had a final diagnosis of TIA (GTN 57, sham 52) with mean age 73 (13) years, 19 (17.4%) had pre-morbid mRS >2, and onset to randomisation was 80 [49, 105] minutes. GTN lowered blood pressure by 7.4/5.2 mmHg compared with sham by hospital arrival. At day 90, GTN had no effect on shift in mRS scores (cOR for increased dependency 1.47, 95% CI 0.70-3.11), but was associated with increased death or dependency (mRS >2): GTN 29 (51.8%) vs. sham 23 (46.9%), OR 3.86 (95% CI 1.09-13.59).Conclusions: Pre-hospital ultra-acute transdermal GTN did not improve overall functional outcome in patients with investigator-diagnosed TIA compared with sham treatment

Prehospital transdermal glyceryl trinitrate for ultra-acute intracerebral hemorrhage

Background and Purpose—Pilot trials suggest that glyceryl trinitrate (GTN; nitroglycerin) may improve outcome when administered early after stroke onset. Methods—We undertook a multicentre, paramedic-delivered, ambulance-based, prospective randomized, sham-controlled, blinded-end point trial in adults with presumed stroke within 4 hours of ictus. Participants received transdermal GTN (5 mg) or a sham dressing (1:1) in the ambulance and then daily for three days in hospital. The primary outcome was the 7-level modified Rankin Scale at 90 days assessed by central telephone treatment-blinded follow-up. This prespecified subgroup analysis focuses on participants with an intracerebral hemorrhage as their index event. Analyses are intention-to-treat. Results—Of 1149 participants with presumed stroke, 145 (13%; GTN, 74; sham, 71) had an intracerebral hemorrhage: time from onset to randomization median, 74 minutes (interquartile range, 45–110). By admission to hospital, blood pressure tended to be lower with GTN as compared with sham: mean, 4.4/3.5 mmHg. The modified Rankin Scale score at 90 days was nonsignificantly higher in the GTN group: adjusted common odds ratio for poor outcome, 1.87 (95% CI, 0.98–3.57). A prespecified global analysis of 5 clinical outcomes (dependency, disability, cognition, quality of life, and mood) was worse with GTN; Mann-Whitney difference, 0.18 (95% CI, 0.01–0.35; Wei-Lachin test). GTN was associated with larger hematoma and growth, and more mass effect and midline shift on neuroimaging, and altered use of hospital resources. Death in hospital but not at day 90 was increased with GTN. There were no significant betweengroup differences in serious adverse events. Conclusions—Prehospital treatment with GTN worsened outcomes in patients with intracerebral hemorrhage. Since these results could relate to the play of chance, confounding, or a true effect of GTN, further randomized evidence on the use of vasodilators in ultra-acute intracerebral hemorrhage is needed

Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans

Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in 25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16 regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP, while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium (LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region. Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa, an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent signals within the same regio

Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity.

Global dispersal and increasing frequency of the SARS-CoV-2 spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large dataset, well represented by both spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant