Developing useful early warning and prognostic scores for COVID-19

Abstract Early recognition of high-risk or deteriorating patients with COVID-19 allows timely treatment escalation and optimises allocation of scarce resources across overstretched healthcare systems. Since the late 1990s, physiological scoring systems have been used in hospital settings to provide an objective signal of clinical deterioration prompting urgent clinical review. Several early warning scores (EWS) accurately predict the need for intensive care unit admission and survival in hospitalised patients with sepsis and other acute illnesses, and their routine use is now recommended in secondary care settings in high and low income countries alike. However, there are widespread concerns that existing EWS, which place a premium on the cardiovascular instability seen in severe sepsis, may fail to identify the deteriorating COVID-19 patient. Dozens of research groups have now assessed the predictive value of existing EWS in hospitalised adults with COVID-19, and used sophisticated statistical methods to develop novel early warning and prognostic scores incorporating vital signs, laboratory tests and imaging results. However, many of these novel scores are at high risk of bias and few have been adopted in routine clinical practice. In this education and learning article, we will discuss key pitfalls of existing prognostic and EWS in hospitalised adults with COVID-19; outline promising novel scores for this patient group; and describe the ideal properties of scoring systems suitable for use in low and middle income settings

The effect of stress on the expression of the amyloid precursor protein in rat brain

AbstractThe abnormal processing of the amyloid precursor protein (APP) is a pivotal event in the development of the unique pathology that defines Alzheimer's disease (AD). Stress, and the associated increase in corticosteroids, appear to accelerate brain ageing and may increase vulnerability to Alzheimer's disease via altered APP processing. In this study, rats were repeatedly exposed to an unavoidable stressor, an open elevated platform. Previous studies in this laboratory have shown that a single exposure produces a marked increase in plasma corticosterone levels but animals develop tolerance to this effect between 10 and 20 daily sessions. Twenty-four hours after stress, there was an increase in the ratio of the deglycosylated form of APP in the particulate fraction of the brain, which subsequently habituated after 20 days. The levels of soluble APP (APPs) tended to be lower in the stress groups compared to controls except for a significant increase in the hippocampus after 20 days of platform exposure. Since APPs is reported to have neurotrophic properties, this increased release may represent a neuroprotective response to repeated stress. It is possible that the ability to mount this response decreases with age thus increasing the vulnerability to stress-induced AD-related pathology

“Step by step”: high frequency short-distance epizoochorous dispersal of aquatic macrophytes

Aquatic macrophytes can successfully colonise and re-colonise areas separated by space and time. The mechanisms underlying such “mobility” are not well understood, but it has often been hypothesised that epizoochory (external dispersal) plays an important role. Yet, there is only limited, and mostly anecdotal, evidence concerning successful epizoochorous dispersal of aquatic macrophytes, particularly in the case of short-distance dispersal. Here we examine in situ and ex situ dispersal of aquatic macrophytes, including three invasive alien species. A high frequency of Lemna minor Linnaeus dispersal was observed in situ, and this was linked to bird-mediated epizoochory. We concluded that wind had no effect on dispersal. Similarly, in an ex situ examination Lemna minuta Kunth and Azolla filiculoides Lamarck, were found to be dispersed with a high frequency by mallard ducks (Anas platyrhynchos). No dispersal was measured for Elodea nuttalli (Planchon) H. St. John. It is concluded that short-distance or “stepping-stone” dispersal via bird-mediated epizoochory can occur with high frequencies, and therefore can play an important role in facilitating colonisation, range expansion and biological invasion of macrophytes

Scoping report on the potential impact of on-board desulphurisation on the water quality in SOx emission control areas

The input of acid substances (like SO2) into the sea has been recognized as an environmental issue that needs to be considered in terms of ocean acidification; acid inputs and techniques to deal with them have implications for member states' obligations under the Water Framework Directive and Marine Strategy Framework Directive. This study provides an initial assessment on the potential impact of on-board desulphurisation equipment (open loop scrubbers) on the seawater quality with focus on SOx Emission Control Areas (SECAs). The study focuses on the potential impact of shipborne SO2 on acidification (pH) of seawater in comparison to the impact from climate change. The report comprises a literature study and a dedicated modelling exercise covering the North Sea region. Most available studies and the peer reviewed literature found only a small additional impact from SO2 emissions on acidification in the various investigated parts of the world ocean. However these studies generally assessed spatially averaged effects and regional and coastal oriented studies are mostly lacking from the literature, which means that potential effects to vulnerable ecosystems in such areas have not previously been considered. A coupled hydrodynamic-chemistry model was employed to assess the impact of adding SO2 and CO2 on the complex carbonate system in sea water. The impact on the pH decrease in the open North Sea region from discharging the acid wash water into the seawater was found to be small, but not insignificant, and regionally varying. The calculated annual mean decrease of pH due to SO2 injection for the North Sea total water column is 0.00011; when considering only the change in the surface layer (0-20m), the annual decrease is 0.00024. The total annual impact from increasing atmospheric CO2 concentrations on the acidification of the North Sea surface area is about 8 times stronger (0.001) than the impact from wash water injection. However because of the pronounced spatial variations the mean impact does not reflect the overall situation well. Consequently we find critical regions with high ship traffic intensity, for example along the shipping lanes and in the larger Rotterdam port area. Here, the contribution from SO2 injection can be double the impact from increasing CO2 concentrations and 20 times larger than the North Sea mean value. These critical regions indicate potential problems related to the surface water quality in ports, estuaries and coastal waters that are subject to regulation under the Water Framework Directive (WFD). In addition, the problem of decreasing pH caused by SO2 input from ship exhaust gases in regional seas (North Sea) is relevant to the obligation of the Member States to assess the environmental state of their marine areas and to establish a Good Environmental Status (GES) under the Marine Strategy Framework Directive (MFSD), as pH value is one of the GES criteria

Antibacterial Coatings for Medical Devices based on Glass Polyalkenoate Cement Chemistry

A biofilm is an accumulation of micro-organisms and their extracellular products forming a structured community on a surface. Biofilm formation on medical devices has severe health consequences as bacteria growing in this lifestyle are tolerant to both host defense mechanisms and antibiotic therapies. However, silver and zinc ions inhibit the attachment and proliferation of immature biofilms. The objective of this study is to evaluate whether it is possible to produce silver and zinc-containing glass polyalkenoate cement (GPC) coatings for medical devices that have antibacterial activity and which may therefore inhibit biofilm formation on a material surface. Two silver and zinc-containing GPC coatings (A and B) were synthesised and coated onto Ti6Al4V discs. Their handling properties were characterised and atomic absorption spectrometery was employed to determine zinc and silver ion release with coating maturation up to 30 days. The antibacterial properties of the coatings were also evaluated against Staphylococcus aureus and a clinical isolate of Pseudomonas aeruginosa using an agar diffusion assay method. The majority of the zinc and silver ions were released within the first 24 h; both coatings exhibited antibacterial effect against the two bacterial strains, but the effect was more intense for B which contained more silver and less zinc than A. Both coatings produced clear zones of inhibition with each of the two organisms tested. In this assay, Ps. aeruginosa was more sensitive than S. aureus. The diameters of these zones were reduced after the coating had been immersed in water for varying periods due to the resultant effect on ion release. © 2008 Springer Science+Business Media, LLC

String Theory and Cosmology

We discuss the main cosmological implications of considering string-loop effects and a potential for the dilaton in the lowest order string effective action. Our framework is based on the effective model arising from regarding homogeneous and isotropic dilaton, metric and Yang-Mills field configurations. The issues of inflation, entropy crisis and the Polonyi problem as well as the problem of the cosmological constant are discussed.Comment: 7 pages, plain Tex, no figure