RsmN : a new atypical RsmA homologue in Pseudomonas aeruginosa

The RsmA/CsrA family of global post-transcriptional regulators are small RNA-binding proteins involved in the regulation of a large number of genes such as those involved in quorum sensing, virulence factor production, secondary metabolism, motility and biofilm formation. They bind to target mRNAs and hence modulate their stability and translation rates. Their effects are antagonised by small non-coding regulatory RNAs. The control of expression of target genes via this post-transcriptional regulatory network is mostly operated in Pseudomonas spp. via the GacS/GacA two component system. This study aimed to perform a biophysical analysis of RsmA and to obtain a preliminary understanding of the structure, function and regulation of RsmN, a new atypical RsmA homologue from Pseudomonas aeruginosa. RsmA was purified and biophysical analysis confirmed that RsmA exists as a dimer and is highly stable at high temperatures (75 °C) and low pH (5.2). Although RsmN was found to be structurally similar to RsmA, no functional phenotypes have been identified. Consequently, rsmN was mutated and transcriptional fusions to rsmN and its anti-sense transcript were constructed for expression studies. Phenotypic analysis indicated that RsmN was not involved in the control of swarming, pyocyanin, elastase and protease production or glycogen accumulation. Unlike RsmA, RsmN does not have a control on the restriction modification system of P. aeruginosa. Transcriptional fusions revealed RetS, LadS and GacA all appear to have a 21 significant effect as activators of both the rsmN and nmsR promoters. 2-Alkyl-4(1H)-quinolone (AQ) signalling also modulate rsmN expression possibly via the iron chelating properties of 2-alkyl-3-hydroxy-4(1H)-heptyl-quinolone (PQS). RsmN targets identified from Deep Sequencing include those required for structural outer membrane proteins, transcriptional regulators as well as genes involved in motility, secretion, flagellar structure and biofilms. RsmA, RsmZ and RsmY were all identified as targets together with the small RNAs RgsA (indirectly gac-controlled) and the antagonistic RNA CrcZ (represses catabolite repression control protein Crc). Targets common to both RsmN and RsmA include the transcriptional regulators Vfr, PqsR, MvaT and Anr, regulatory RNAs RsmZ and RsmY together with transcripts corresponding to the pqsABCDE operon, LasB, LecA/B, RhlI, LasR/I, Crc and CrcZ. The identification of many mRNA targets for RsmN which are shared with targets of RsmA provides further evidence that RsmN is involved in global-post-transcriptional regulation of gene expression

RsmN : a new atypical RsmA homologue in Pseudomonas aeruginosa

The RsmA/CsrA family of global post-transcriptional regulators are small RNA-binding proteins involved in the regulation of a large number of genes such as those involved in quorum sensing, virulence factor production, secondary metabolism, motility and biofilm formation. They bind to target mRNAs and hence modulate their stability and translation rates. Their effects are antagonised by small non-coding regulatory RNAs. The control of expression of target genes via this post-transcriptional regulatory network is mostly operated in Pseudomonas spp. via the GacS/GacA two component system. This study aimed to perform a biophysical analysis of RsmA and to obtain a preliminary understanding of the structure, function and regulation of RsmN, a new atypical RsmA homologue from Pseudomonas aeruginosa. RsmA was purified and biophysical analysis confirmed that RsmA exists as a dimer and is highly stable at high temperatures (75 °C) and low pH (5.2). Although RsmN was found to be structurally similar to RsmA, no functional phenotypes have been identified. Consequently, rsmN was mutated and transcriptional fusions to rsmN and its anti-sense transcript were constructed for expression studies. Phenotypic analysis indicated that RsmN was not involved in the control of swarming, pyocyanin, elastase and protease production or glycogen accumulation. Unlike RsmA, RsmN does not have a control on the restriction modification system of P. aeruginosa. Transcriptional fusions revealed RetS, LadS and GacA all appear to have a 21 significant effect as activators of both the rsmN and nmsR promoters. 2-Alkyl-4(1H)-quinolone (AQ) signalling also modulate rsmN expression possibly via the iron chelating properties of 2-alkyl-3-hydroxy-4(1H)-heptyl-quinolone (PQS). RsmN targets identified from Deep Sequencing include those required for structural outer membrane proteins, transcriptional regulators as well as genes involved in motility, secretion, flagellar structure and biofilms. RsmA, RsmZ and RsmY were all identified as targets together with the small RNAs RgsA (indirectly gac-controlled) and the antagonistic RNA CrcZ (represses catabolite repression control protein Crc). Targets common to both RsmN and RsmA include the transcriptional regulators Vfr, PqsR, MvaT and Anr, regulatory RNAs RsmZ and RsmY together with transcripts corresponding to the pqsABCDE operon, LasB, LecA/B, RhlI, LasR/I, Crc and CrcZ. The identification of many mRNA targets for RsmN which are shared with targets of RsmA provides further evidence that RsmN is involved in global-post-transcriptional regulation of gene expression

Genome-wide mapping of the RNA targets of the Pseudomonas aeruginosa riboregulatory protein RsmN

Pseudomonads typically carry multiple non-identical alleles of the post-transcriptional regulator rsmA. In P. aeruginosa, RsmN is notable in that its structural rearrangement confers distinct and overlapping functions with RsmA. However, little is known about the specificities of RsmN for its target RNAs and overall impact on the biology of this pathogen. We purified and mapped 503 transcripts directly bound by RsmN in P. aeruginosa. About 200 of the mRNAs identified encode proteins of demonstrated function including some determining acute and chronic virulence traits. For example, RsmN reduces biofilm development both directly and indirectly via multiple pathways, involving control of Pel exopolysaccharide biosynthesis and c-di-GMP levels. The RsmN targets identified are also shared with RsmA, although deletion of rsmN generally results in less pronounced phenotypes than those observed for ΔrsmA or ΔrsmArsmNind mutants, probably as a consequence of different binding affinities. Targets newly identified for the Rsm system include the small non-coding RNA CrcZ involved in carbon catabolite repression, for which differential binding of RsmN and RsmA to specific CrcZ regions is demonstrated. The results presented here provide new insights into the intricacy of riboregulatory networks involving multiple but distinct RsmA homologues

Improving the Quality of Dentistry (IQuaD):a cluster factorial randomised controlled trial comparing the effectiveness and cost-benefit of oral hygiene advice and/or periodontal instrumentation with routine care for the prevention and management of periodontal disease in dentate adults attending dental primary care

Acknowledgements The authors wish to thank Mark Forrest and the programming team at CHaRT; Cynthia Fraser, our information specialist, for assistance with referencing; Moira Swan, who was the dental research nurse and part of the OA team in Newcastle upon Tyne; Louise Campbell for secretarial support and data management; our original statistician in the group, Andy Elders; senior IT manager Gladys Macpherson; senior trial administrator at the TCOD Marilyn Laird; Luke Vale for his involvement with the design of the health economic analysis at the inception of the trial; Maria Dimitrova, who assisted the health economists in the collection of unit costs; staff of the Scottish Primary Care Research Network, who assisted with screening eligible patients at dental practices; staff of the North East Commissioning Support Unit who assisted with research payments to dental practices in the north-east; members of the TMC and Periodontal Advisory Group for their ongoing advice and support of the trial; the independent members of the TSC and DMC; and the staff at recruitment sites who facilitated recruitment, treatment and follow-up of trial participants. The Health Services Research Unit and the Health Economics Research Unit is core funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorate.Peer reviewedPublisher PD

Blood Banking in Living Droplets

Blood banking has a broad public health impact influencing millions of lives daily. It could potentially benefit from emerging biopreservation technologies. However, although vitrification has shown advantages over traditional cryopreservation techniques, it has not been incorporated into transfusion medicine mainly due to throughput challenges. Here, we present a scalable method that can vitrify red blood cells in microdroplets. This approach enables the vitrification of large volumes of blood in a short amount of time, and makes it a viable and scalable biotechnology tool for blood cryopreservation.National Institutes of Health (U.S.) (NIH R21 EB007707)Wallace H. Coulter FoundationUnited States. Army Medical Research and Materiel Command (Acquisition Activity Cooperative Agreement RO1 A1081534)Center for Integration of Medicine and Innovative TechnologyUnited States. Army Medical Research and Materiel Command (Acquisition Activity Cooperative Agreement R21 AI087107)United States. Army. Telemedicine & Advanced Technology Research Cente

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

IQuaD dental trial; improving the quality of dentistry : a multicentre randomised controlled trial comparing oral hygiene advice and periodontal instrumentation for the prevention and management of periodontal disease in dentate adults attending dental primary care

Peer reviewedPublisher PD

Bleeding in cardiac patients prescribed antithrombotic drugs: Electronic health record phenotyping algorithms, incidence, trends and prognosis

Background Clinical guidelines and public health authorities lack recommendations on scalable approaches to defining and monitoring the occurrence and severity of bleeding in populations prescribed antithrombotic therapy. Methods We examined linked primary care, hospital admission and death registry electronic health records (CALIBER 1998–2010, England) of patients with newly diagnosed atrial fibrillation, acute myocardial infarction, unstable angina or stable angina with the aim to develop algorithms for bleeding events. Using the developed bleeding phenotypes, Kaplan-Meier plots were used to estimate the incidence of bleeding events and we used Cox regression models to assess the prognosis for all-cause mortality, atherothrombotic events and further bleeding. Results We present electronic health record phenotyping algorithms for bleeding based on bleeding diagnosis in primary or hospital care, symptoms, transfusion, surgical procedures and haemoglobin values. In validation of the phenotype, we estimated a positive predictive value of 0.88 (95% CI 0.64, 0.99) for hospitalised bleeding. Amongst 128,815 patients, 27,259 (21.2%) had at least 1 bleeding event, with 5-year risks of bleeding of 29.1%, 21.9%, 25.3% and 23.4% following diagnoses of atrial fibrillation, acute myocardial infarction, unstable angina and stable angina, respectively. Rates of hospitalised bleeding per 1000 patients more than doubled from 1.02 (95% CI 0.83, 1.22) in January 1998 to 2.68 (95% CI 2.49, 2.88) in December 2009 coinciding with the increased rates of antiplatelet and vitamin K antagonist prescribing. Patients with hospitalised bleeding and primary care bleeding, with or without markers of severity, were at increased risk of all-cause mortality and atherothrombotic events compared to those with no bleeding. For example, the hazard ratio for all-cause mortality was 1.98 (95% CI 1.86, 2.11) for primary care bleeding with markers of severity and 1.99 (95% CI 1.92, 2.05) for hospitalised bleeding without markers of severity, compared to patients with no bleeding. Conclusions Electronic health record bleeding phenotyping algorithms offer a scalable approach to monitoring bleeding in the population. Incidence of bleeding has doubled in incidence since 1998, affects one in four cardiovascular disease patients, and is associated with poor prognosis. Efforts are required to tackle this iatrogenic epidemic

Widespread retreat of coastal habitat is likely at warming levels above 1.5 °C

Several coastal ecosystems—most notably mangroves and tidal marshes—exhibit biogenic feedbacks that are facilitating adjustment to relative sea-level rise (RSLR), including the sequestration of carbon and the trapping of mineral sediment. The stability of reef-top habitats under RSLR is similarly linked to reef-derived sediment accumulation and the vertical accretion of protective coral reefs. The persistence of these ecosystems under high rates of RSLR is contested. Here we show that the probability of vertical adjustment to RSLR inferred from palaeo-stratigraphic observations aligns with contemporary in situ survey measurements. A defcit between tidal marsh and mangrove adjustment and RSLR is likely at 4 mm yr−1 and highly likely at 7 mm yr−1 of RSLR. As rates of RSLR exceed 7 mm yr−1, the probability that reef islands destabilize through increased shoreline erosion and wave over-topping increases. Increased global warming from 1.5 °C to 2.0 °C would double the area of mapped tidal marsh exposed to 4 mm yr−1 of RSLR by between 2080 and 2100. With 3 °C of warming, nearly all the world’s mangrove forests and coral reef islands and almost 40% of mapped tidal marshes are estimated to be exposed to RSLR of at least 7 mm yr−1. Meeting the Paris agreement targets would minimize disruption to coastal ecosystems

Seagrass and submerged aquatic vegetation (VAS) habitats off the Coast of Brazil: state of knowledge, conservation and main threats

Seagrass meadows are among the most threatened ecosystems on earth, raising concerns about the equilibrium of coastal ecosystems and the sustainability of local fisheries. The present review evaluated the current status of the research on seagrasses and submerged aquatic vegetation (SAV) habitats off the coast of Brazil in terms of plant responses to environmental conditions, changes in distribution and abundance, and the possible role of climate change and variability. Despite an increase in the number of studies, the communication of the results is still relatively limited and is mainly addressed to a national or regional public; thus, South American seagrasses are rarely included or cited in global reviews and models. The scarcity of large-scale and long-term studies allowing the detection of changes in the structure, abundance and composition of seagrass habitats and associated species still hinders the investigation of such communities with respect to the potential effects of climate change. Seagrass meadows and SAV occur all along the Brazilian coast, with species distribution and abundance being strongly influenced by regional oceanography, coastal water masses, river runoff and coastal geomorphology. Based on these geomorphological, hydrological and ecological features, we characterised the distribution of seagrass habitats and abundances within the major coastal compartments. The current conservation status of Brazilian seagrasses and SAV is critical. The unsustainable exploitation and occupation of coastal areas and the multifold anthropogenic footprints left during the last 100 years led to the loss and degradation of shoreline habitats potentially suitable for seagrass occupation. Knowledge of the prevailing patterns and processes governing seagrass structure and functioning along the Brazilian coast is necessary for the global discussion on climate change. Our review is a first and much-needed step toward a more integrated and inclusive approach to understanding the diversity of coastal plant formations along the Southwestern Atlantic coast as well as a regional alert the projected or predicted effects of global changes on the goods and services provided by regional seagrasses and SAV