479 research outputs found
Aetiological role of viral and bacterial infections in acute adult lower respiratory tract infection (LRTI) in primary care.
BACKGROUND: Lower respiratory tract infections (LRTI) are a common reason for consulting general practitioners (GPs). In most cases the aetiology is unknown, yet most result in an antibiotic prescription. The aetiology of LRTI was investigated in a prospective controlled study. METHODS: Eighty adults presenting to GPs with acute LRTI were recruited together with 49 controls over 12 months. Throat swabs, nasal aspirates (patients and controls), and sputum (patients) were obtained and polymerase chain reaction (PCR) and reverse transcriptase polymerase chain reaction (RT-PCR) assays were used to detect Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophila, influenza viruses (AH1, AH3 and B), parainfluenza viruses 1-3, coronaviruses, respiratory syncytial virus, adenoviruses, rhinoviruses, and enteroviruses. Standard sputum bacteriology was also performed. Outcome was recorded at a follow up visit. RESULTS: Potential pathogens were identified in 55 patients with LRTI (69%) and seven controls (14%; p<0.0001). The identification rate was 63% (viruses) and 26% (bacteria) for patients and 12% (p<0.0001) and 6% (p = 0.013), respectively, for controls. The most common organisms identified in the patients were rhinoviruses (33%), influenza viruses (24%), and Streptococcus pneumoniae (19%) compared with 2% (p<0.001), 6% (p = 0.013), and 4% (p = 0.034), respectively, in controls. Multiple pathogens were identified in 18 of the 80 LRTI patients (22.5%) and in two of the 49 controls (4%; p = 0.011). Atypical organisms were rarely identified. Cases with bacterial aetiology were clinically indistinguishable from those with viral aetiology. CONCLUSION: Patients presenting to GPs with acute adult LRTI predominantly have a viral illness which is most commonly caused by rhinoviruses and influenza viruses
Predicting function from sequence in a large multifunctional toxin family
Venoms contain active substances with highly specific physiological effects and are increasingly being used as sources of novel diagnostic, research and treatment tools for human disease. Experimental characterisation of individual toxin activities is a severe rate-limiting step in the discovery process, and in-silico tools which allow function to be predicted from sequence information are essential. Toxins are typically members of large multifunctional families of structurally similar proteins that can have different biological activities, and minor sequence divergence can have significant consequences. Thus, existing predictive tools tend to have low accuracy. We investigated a classification model based on physico-chemical attributes that can easily be calculated from amino-acid sequences, using over 250 (mostly novel) viperid phospholipase A2 toxins. We also clustered proteins by sequence profiles, and carried out in-vitro tests for four major activities on a selection of isolated novel toxins, or crude venoms known to contain them. The majority of detected activities were consistent with predictions, in contrast to poor performance of a number of tested existing predictive methods. Our results provide a framework for comparison of active sites among different functional sub-groups of toxins that will allow a more targeted approach for identification of potential drug leads in the future
Isolation of marine meiofauna from sandy sediments From decanting to DNA extraction
This protocol describes the separation of marine meiofauna from sediment and subsequent
environmental DNA extraction. In this study meiofauna samples were taken with a 45 mm core from
the upper 5 to 10 cm of sediment layer. Separation from sediment was achieved using a decantation
process followed by isolation from fine silt using repetitive centrifugation steps with a 1.16 specific
gravity (sg) LUDOX-TM solution. Meiofauna were deliberately separated from macrofauna by using
a 1 mm sieve on top of a bottle-top sterile 45 !M sieve. High quality DNA was subsequently
obtained using the QIAamp DNA Blood Maxi Kit (Qiagen) with minor adjustments to the
manufacturer’s protocol. This procedure allowed efficient isolation of meiofaunal representatives
from marine sediments and also extraction of high quality environmental DNA that can be used for
downstream metagenetic analysis
Experimental harvesting of fish populations drives genetically based shifts in body size and maturation
Size-selective harvesting in commercial fisheries can induce rapid changes in biological traits. While experimental and wild harvested populations often exhibit clear shifts in body size and maturation associated with fishing pressure, the relative contributions of genetic and environmental factors to these shifts remain uncertain and have been much debated. To date, observations of so-called fisheries-induced evolution (FIE) have been based solely on phenotypic measures, such as size data. Genetic data are hitherto lacking. Here, we quantify genetic versus environmental change in response to size-selective harvesting for small and large body size in guppies (Poecilia reticulata) across three generations of selection. We document for the first time significant changes at individual genetic loci, some of which have previously been associated with body size. In contrast, variation at neutral microsatellite markers was unaffected by selection, providing direct genetic evidence for rapid evolution induced by size-selective harvesting. These findings demonstrate FIE in an experimental system, with major implications for the sustainability of harvested populations, as well as impacts on size-structured communities and ecosystem processes. These findings highlight the need for scientists and managers to reconsider the capacity of harvested stocks to adapt to, and recover from, harvesting and predation. © 2013 The Ecological Society of America
Using domiciliary non-invasive ventilator data downloads to inform clinical decision-making to optimise ventilation delivery and patient compliance
© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted. Introduction Ventilation parameter data from patients receiving home mechanical ventilation can be collected via secure data cards and modem technology. This can then be reviewed by clinicians and ventilator prescriptions adjusted. Typically available measures include tidal volume (V T ), leak, respiratory rate, minute ventilation, patient triggered breaths, achieved pressures and patient compliance. This study aimed to assess the potential impact of ventilator data downloads on management of patients requiring home non-invasive ventilation (NIV). Methods A longitudinal within-group design with repeated measurements was used. Baseline ventilator data were downloaded, reviewed and adjustments made to optimise ventilation. Leak, V T and compliance data were collected for comparison at the first review and 3-7 weeks later. Ventilator data were monitored and amended remotely via a modem by a consultant physiotherapist between the first review and second appointment. Results Analysis of data from 52 patients showed increased patient compliance (% days used > 4 hours) from 90% to 96% (p=0.007), increased usage from 6.53 to 6.94 hours (p=0.211) and a change in V T (9.4 vs 8.7 mL/kg/ideal body weight, p=0.022). There was no change in leak following review of NIV prescriptions (mean (SD): 43 (23.4) L/min vs 45 (19.9)L/min, p=0.272). Conclusion Ventilator data downloads, via early remote assessment, can help optimise patient ventilation through identification of modifiable factors, in particular interface leak and ventilator prescriptions. However, a prospective study is required to assess whether using ventilator data downloads provides value in terms of patient outcomes and cost-effectiveness. The presented data will help to inform the design of such a study
Prevalence of people who could benefit from augmentative and alternative communication (AAC) in the UK: determining the need.
BACKGROUND: Commissioners and providers require information relating to the number of people requiring a service in order to ensure provision is appropriate and equitable for the population they serve. There is little epidemiological evidence available regarding the prevalence of people who could benefit from augmentative and alternative communication (AAC) in the UK. AIM: To determine the prevalence of people who could benefit from AAC in the UK. METHODS & PROCEDURES: An epidemiological approach was taken to create a new estimate of need: the prevalence of the main medical conditions and specific symptoms leading to the requirement for AAC were identified from the literature and AAC specialists were consulted to estimate the number of people who may require AAC. OUTCOMES & RESULTS: A total of 97.8% of the total number of people who could benefit from AAC have nine medical conditions: dementia, Parkinson's disease, autism, learning disability, stroke, cerebral palsy, head injury, multiple sclerosis and motor neurone disease. The total expectation is that 536 people per 100 000 of the UK population (approximately 0.5%) could benefit from AAC. CONCLUSIONS & IMPLICATIONS: To provide accurate figures on the potential need for and use of AAC, data need to be consistently and accurately recorded and regularly reviewed at a community level. The existing data suggest an urgent need for more accurate and up to date information to be captured about the need for AAC in the UK to provide better services and ensure access to AAC strategies, equipment and support
Convergence of multiple markers and analysis methods defines the genetic distinctiveness of cryptic pitvipers
Using multiple markers and multiple analytical approaches is critical for establishing species boundaries reliably, especially so in the case of cryptic species. Despite development of new and powerful analytical methods, most studies continue to adopt a few, with the choice often being subjective. One such example is routine analysis of Amplified Fragment Length Polymorphism (AFLP) data using population genetic models despite disparity between method assumptions and data properties. The application of newly developed methods for analyzing this dominant marker may not be entirely clear in the context of species delimitation. In this study, we use AFLPs and mtDNA to investigate cryptic speciation in the Trimeresurus macrops complex that belongs to a taxonomically difficult lineage of Asian pitvipers. We analyze AFLPs using population genetic, phylogenetic, multivariate statistical, and Bayes Factor Delimitation methods. A gene tree from three mtDNA markers provided additional evidence. Our results show that the inferences about species boundaries that can be derived from population genetic analysis of AFLPs have certain limitations. In contrast, four multivariate statistical analyses produced clear clusters that are consistent with each other, as well as with Bayes Factor Delimitation results, and with mtDNA and total evidence phylogenies. Furthermore, our results concur with allopatric distributions and patterns of variation in individual morphological characters previously identified in the three proposed species: T. macrops sensu stricto, T. cardamomensis, and T. rubeus. Our study provides evidence for reproductive isolation and genetic distinctiveness that define these taxa as full species. In addition, we re-emphasize the importance of examining congruence of results from multiple methods of AFLP analysis for inferring species diversity
Revealing higher than expected meiofaunal diversity in Antarctic sediments:a metabarcoding approach
An increasing number of studies are showing that Antarctic mega- and macrofauna are highly diverse, however, little is known about meiofaunal biodiversity in sediment communities, which are a vital part of a healthy and functional ecosystem. This is the first study to analyse community DNA (targeting meiofauna) using metabarcoding to investigate biodiversity levels in sediment communities of the Antarctic Peninsula. The results show that almost all of the meiofaunal biodiversity in the benthic habitat has yet to be characterised, levels of biodiversity were higher than expected and similar to temperate regions, albeit with the existence of potentially new and locally adapted species never described before at the molecular level. The Rothera meiofaunal sample sites showed four dominant eukaryotic groups, the nematodes, arthropods, platyhelminthes, and the annelids; some of which could comprise species complexes. Comparisons with deep-sea data from the same region suggest little exchange of Operational Taxonomic Units (OTUs) between depths with the nematodes prevalent at all depths, but sharing the shallow water benthos with the copepods. This study provides a preliminary analysis of benthic Antarctic Peninsula meiofauna using high throughput sequencing which substantiates how little is known on the biodiversity of one of the most diverse, yet underexplored communities of the Antarctic: the benthos
Coexisting cryptic species of the Litoditis marina complex (Nematoda) show differential resource use and have distinct microbiomes with high intraspecific variability
Differences in resource use or in tolerances to abiotic conditions are often invoked as potential mechanisms underlying the sympatric distribution of cryptic species. Additionally, the microbiome can provide physiological adaptations of the host to environmental conditions. We determined the intra-and interspecific variability of the microbiomes of three cryptic nematode species of the Litoditis marina species complex that co-occur, but show differences in abiotic tolerances. Roche 454 pyrosequencing of the microbial 16S rRNA gene revealed distinct bacterial communities characterized by a substantial diversity (85-513 OTUs) and many rare OTUs. The core microbiome of each species contained only very few OTUs (2-6), and four OTUs were identified as potentially generating tolerance to abiotic conditions. A controlled experiment in which nematodes from two cryptic species (Pm1 and Pm3) were fed with either an E. coli suspension or a bacterial mix was performed, and the 16S rRNA gene was sequenced using the MiSeq technology. OTU richness was 10-fold higher compared to the 454 data set and ranged between 1118 and 7864. This experiment confirmed the existence of species-specific microbiomes, a core microbiome with few OTUs, and high interindividual variability. The offered food source affected the bacterial community and illustrated different feeding behaviour between the cryptic species, with Pm3 exhibiting a higher degree of selective feeding than Pm1. Morphologically similar species belonging to the same feeding guild (bacterivores) can thus have substantial differences in their associated microbiomes and feeding strategy, which in turn may have important ramifications for biodiversity-ecosystem functioning relationships
Improved treatment completion for tuberculosis patients: The case for a dedicated social care team
OBJECTIVES: The increasing social needs of people with Tuberculosis (TB), and the poor adherence to anti-TB therapy (ATT) associated with homelessness, drug or alcohol abuse, and prison history, led us to introduce a social care team (SCT) to support patient engagement with care within this low TB incidence setting. METHODS: Using a risk assessment, patients with social risk factors (SRF) for non-adherence to ATT are identified and a referral made to the SCT, who then provide intensive casework support for areas including homelessness, housing, benefits, debt and immigration. Retrospective data analysis of the social care database from 2017 to 2019 was conducted. Patients who were (n = 170) and were not referred to the SCT (n = 734) were compared. RESULTS: Patients referred were significantly more likely to complete treatment for TB than those not (88.2% versus 77.7% respectively, p = 0.0025), irrespective of receipt of Directly/Video Observed Therapy and adjusting for confounders. CONCLUSIONS: This paper demonstrates important evidence for the positive impact of a dedicated SCT within a TB service, and these improved treatment outcomes provide a strong argument for development of similar SCTs within UK TB services and similar healthcare settings
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