Background In this study, we aimed to evaluate the effects of tocilizumab in adult patients admitted to hospital with COVID-19 with both hypoxia and systemic inflammation. Methods This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. Those trial participants with hypoxia (oxygen saturation <92% on air or requiring oxygen therapy) and evidence of systemic inflammation (C-reactive protein ≥75 mg/L) were eligible for random assignment in a 1:1 ratio to usual standard of care alone versus usual standard of care plus tocilizumab at a dose of 400 mg–800 mg (depending on weight) given intravenously. A second dose could be given 12–24 h later if the patient's condition had not improved. The primary outcome was 28-day mortality, assessed in the intention-to-treat population. The trial is registered with ISRCTN (50189673) and ClinicalTrials.gov ( NCT04381936 ). Findings Between April 23, 2020, and Jan 24, 2021, 4116 adults of 21 550 patients enrolled into the RECOVERY trial were included in the assessment of tocilizumab, including 3385 (82%) patients receiving systemic corticosteroids. Overall, 621 (31%) of the 2022 patients allocated tocilizumab and 729 (35%) of the 2094 patients allocated to usual care died within 28 days (rate ratio 0·85; 95% CI 0·76–0·94; p=0·0028). Consistent results were seen in all prespecified subgroups of patients, including those receiving systemic corticosteroids. Patients allocated to tocilizumab were more likely to be discharged from hospital within 28 days (57% vs 50%; rate ratio 1·22; 1·12–1·33; p<0·0001). Among those not receiving invasive mechanical ventilation at baseline, patients allocated tocilizumab were less likely to reach the composite endpoint of invasive mechanical ventilation or death (35% vs 42%; risk ratio 0·84; 95% CI 0·77–0·92; p<0·0001). Interpretation In hospitalised COVID-19 patients with hypoxia and systemic inflammation, tocilizumab improved survival and other clinical outcomes. These benefits were seen regardless of the amount of respiratory support and were additional to the benefits of systemic corticosteroids. Funding UK Research and Innovation (Medical Research Council) and National Institute of Health Research.

Ionizing radiation has long been known to induce heritable mutagenic change in DNA sequence. However, the genomewide effect of radiation is not well understood. Here we report the molecular properties and frequency of mutations in phenotypically selected mutant lines isolated following exposure of the genetic model flowering plant Arabidopsis thaliana to fast neutrons (FNs). Previous studies suggested that FNs predominantly induce deletions longer than a kilobase in A. thaliana. However, we found a higher frequency of single base substitution than deletion mutations. While the overall frequency and molecular spectrum of fast-neutron (FN)-induced single base substitutions differed substantially from those of ''background'' mutations arising spontaneously in laboratory-grown plants, G:C >A:T transitions were favored in both. We found that FN-induced G:C>A:T transitions were concentrated at pyrimidine dinucleotide sites, suggesting that FNs promote the formation of mutational covalent linkages between adjacent pyrimidine residues. In addition, we found that FNs induced more single base than large deletions, and that these single base deletions were possibly caused by replication slippage. Our observations provide an initial picture of the genome-wide molecular profile of mutations induced in A. thaliana by FN irradiation and are particularly informative of the nature and extent of genome-wide mutation in lines selected on the basis of mutant phenotypes from FN-mutagenized A. thaliana populations.[Supplemental material is available for this article.]Ionizing radiation is pervasive in the environment and acts as a natural mutagen via its DNA-damaging properties (Friedberg et al. 2006). In addition, the mutagenic property of artificial ionizing radiation has been a mainstay of genetic research since the pioneering experiments of Müller (1928). However, while the effects of ionizing radiation on individual genes are now relatively well understood, its genome-wide effects are not. We therefore undertook an analysis of the genome-wide consequences of fast neutron (FN) irradiation in Arabidopsis thaliana, comparing our findings with those of recent studies documenting the frequency and molecular spectrum of spontaneous ''background'' mutations in the genomes of laboratory-grown ''mutation accumulation'' (MA) line Arabidopsis plants (Ossowski et al. 2010) and of Arabidopsis plants regenerated in vitro from root tissue explants (Jiang et al. 2011). We found that exposure of Arabidopsis to FNs induces a broader range of mutational lesions than previously suspected, and that both the incidence and spectrum of FN-induced mutations are distinct from those of ''spontaneous'' mutations. These discoveries have important consequences for the use of FNs in experimental plant mutagenesis and provide an indication of the likely mutagenic effects of environmental ionizing radiation on organisms living in the wild (Hinton et al. 2007). Results FN irradiation, mutant generation, and isolationOur analyses began with a multiply mutant Arab...

No abstract

No abstract

No abstract