2,268 research outputs found
STRONG: metagenomics strain resolution on assembly graphs
We introduce STrain Resolution ON assembly Graphs (STRONG), which identifies strains de novo, from multiple metagenome samples. STRONG performs coassembly, and binning into metagenome assembled genomes (MAGs), and stores the coassembly graph prior to variant simplification. This enables the subgraphs and their unitig per-sample coverages, for individual single-copy core genes (SCGs) in each MAG, to be extracted. A Bayesian algorithm, BayesPaths, determines the number of strains present, their haplotypes or sequences on the SCGs, and abundances. STRONG is validated using synthetic communities and for a real anaerobic digestor time series generates haplotypes that match those observed from long Nanopore reads
Hypoxia upregulates neutrophil degranulation and potential for tissue injury.
BACKGROUND: The inflamed bronchial mucosal surface is a profoundly hypoxic environment. Neutrophilic airway inflammation and neutrophil-derived proteases have been linked to disease progression in conditions such as COPD and cystic fibrosis, but the effects of hypoxia on potentially harmful neutrophil functional responses such as degranulation are unknown. METHODS AND RESULTS: Following exposure to hypoxia (0.8% oxygen, 3 kPa for 4 h), neutrophils stimulated with inflammatory agonists (granulocyte-macrophage colony stimulating factor or platelet-activating factor and formylated peptide) displayed a markedly augmented (twofold to sixfold) release of azurophilic (neutrophil elastase, myeloperoxidase), specific (lactoferrin) and gelatinase (matrix metalloproteinase-9) granule contents. Neutrophil supernatants derived under hypoxic but not normoxic conditions induced extensive airway epithelial cell detachment and death, which was prevented by coincubation with the antiprotease α-1 antitrypsin; both normoxic and hypoxic supernatants impaired ciliary function. Surprisingly, the hypoxic upregulation of neutrophil degranulation was not dependent on hypoxia-inducible factor (HIF), nor was it fully reversed by inhibition of phospholipase C signalling. Hypoxia augmented the resting and cytokine-stimulated phosphorylation of AKT, and inhibition of phosphoinositide 3-kinase (PI3K)γ (but not other PI3K isoforms) prevented the hypoxic upregulation of neutrophil elastase release. CONCLUSION: Hypoxia augments neutrophil degranulation and confers enhanced potential for damage to respiratory airway epithelial cells in a HIF-independent but PI3Kγ-dependent fashion.Supported by the British Lung Foundation, Papworth Hospital NHS Foundation Trust, BBSRC and the Cambridge NIHR-Biomedical Research Centre. CS was funded by Wellcome Trust Early Postdoctoral Research Fellowship for Clinician Scientists (WT101692MA).This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by BMJ Publishing Group
Donor insulin use predicts beta‐cell function after islet transplantation
Insulin is routinely used to manage hyperglycaemia in organ donors and during the peri-transplant period in islet transplant recipients. However, it is unknown whether donor insulin use (DIU) predicts beta-cell dysfunction after islet transplantation. We reviewed data from the UK Transplant Registry and the UK Islet Transplant Consortium; all first-time transplants during 2008-2016 were included. Linear regression models determined associations between DIU, median and coefficient of variation (CV) peri-transplant glucose levels and 3-month islet graft function. In 91 islet cell transplant recipients, DIU was associated with lower islet function assessed by BETA-2 scores (β [SE] -3.5 [1.5], P = .02), higher 3-month post-transplant HbA1c levels (5.4 [2.6] mmol/mol, P = .04) and lower fasting C-peptide levels (−107.9 [46.1] pmol/l, P = .02). Glucose at 10 512 time points was recorded during the first 5 days peri-transplant: the median (IQR) daily glucose level was 7.9 (7.0-8.9) mmol/L and glucose CV was 28% (21%-35%). Neither median glucose levels nor glucose CV predicted outcomes post-transplantation. Data on DIU predicts beta-cell dysfunction 3 months after islet transplantation and could help improve donor selection and transplant outcomes
Estimation of the national disease burden of influenza-associated severe acute respiratory illness in Kenya and Guatemala : a novel methodology
Background:
Knowing the national disease burden of severe influenza in low-income countries can inform policy decisions around influenza treatment and prevention. We present a novel methodology using locally generated data for estimating this burden.
Methods and Findings:
This method begins with calculating the hospitalized severe acute respiratory illness (SARI) incidence for children <5 years old and persons ≥5 years old from population-based surveillance in one province. This base rate of SARI is then adjusted for each province based on the prevalence of risk factors and healthcare-seeking behavior. The percentage of SARI with influenza virus detected is determined from provincial-level sentinel surveillance and applied to the adjusted provincial rates of hospitalized SARI. Healthcare-seeking data from healthcare utilization surveys is used to estimate non-hospitalized influenza-associated SARI. Rates of hospitalized and non-hospitalized influenza-associated SARI are applied to census data to calculate the national number of cases. The method was field-tested in Kenya, and validated in Guatemala, using data from August 2009–July 2011. In Kenya (2009 population 38.6 million persons), the annual number of hospitalized influenza-associated SARI cases ranged from 17,129–27,659 for children <5 years old (2.9–4.7 per 1,000 persons) and 6,882–7,836 for persons ≥5 years old (0.21–0.24 per 1,000 persons), depending on year and base rate used. In Guatemala (2011 population 14.7 million persons), the annual number of hospitalized cases of influenza-associated pneumonia ranged from 1,065–2,259 (0.5–1.0 per 1,000 persons) among children <5 years old and 779–2,252 cases (0.1–0.2 per 1,000 persons) for persons ≥5 years old, depending on year and base rate used. In both countries, the number of non-hospitalized influenza-associated cases was several-fold higher than the hospitalized cases.
Conclusions: Influenza virus was associated with a substantial amount of severe disease in Kenya and Guatemala. This
method can be performed in most low and lower-middle income countries
The split property for quantum field theories in flat and curved spacetimes
The split property expresses a strong form of independence of spacelike separated regions in algebraic quantum field theory. In Minkowski spacetime, it can be proved under hypotheses of nuclearity. An expository account is given of nuclearity and the split property, and connections are drawn to the theory of quantum energy inequalities. In addition, a recent proof of the split property for quantum field theory in curved spacetimes is outlined, emphasising the essential ideas
Prevalence of Disorders Recorded in Dogs Attending Primary-Care Veterinary Practices in England
Purebred dog health is thought to be compromised by an increasing occurence of inherited diseases but inadequate prevalence data on common disorders have hampered efforts to prioritise health reforms. Analysis of primary veterinary practice clinical data has been proposed for reliable estimation of disorder prevalence in dogs. Electronic patient record (EPR) data were collected on 148,741 dogs attending 93 clinics across central and south-eastern England. Analysis in detail of a random sample of EPRs relating to 3,884 dogs from 89 clinics identified the most frequently recorded disorders as otitis externa (prevalence 10.2%, 95% CI: 9.1-11.3), periodontal disease (9.3%, 95% CI: 8.3-10.3) and anal sac impaction (7.1%, 95% CI: 6.1-8.1). Using syndromic classification, the most prevalent body location affected was the head-and-neck (32.8%, 95% CI: 30.7-34.9), the most prevalent organ system affected was the integument (36.3%, 95% CI: 33.9-38.6) and the most prevalent pathophysiologic process diagnosed was inflammation (32.1%, 95% CI: 29.8-34.3). Among the twenty most-frequently recorded disorders, purebred dogs had a significantly higher prevalence compared with crossbreds for three: otitis externa (P = 0.001), obesity (P = 0.006) and skin mass lesion (P = 0.033), and popular breeds differed significantly from each other in their prevalence for five: periodontal disease (P = 0.002), overgrown nails (P = 0.004), degenerative joint disease (P = 0.005), obesity (P = 0.001) and lipoma (P = 0.003). These results fill a crucial data gap in disorder prevalence information and assist with disorder prioritisation. The results suggest that, for maximal impact, breeding reforms should target commonly-diagnosed complex disorders that are amenable to genetic improvement and should place special focus on at-risk breeds. Future studies evaluating disorder severity and duration will augment the usefulness of the disorder prevalence information reported herein
Effects of a recombinant gene expression on ColE1-like plasmid segregation in Escherichia coli
<p>Abstract</p> <p>Background</p> <p>Segregation of expression plasmids leads to loss of recombinant DNA from transformed bacterial cells due to the irregular distribution of plasmids between the daughter cells during cell division. Under non-selective conditions this segregational instability results in a heterogeneous population of cells, where the non-productive plasmid-free cells overgrow the plasmid-bearing cells thus decreasing the yield of recombinant protein. Amongst the factors affecting segregational plasmid instability are: the plasmid design, plasmid copy-number, host cell genotype, fermentation conditions etc. This study aims to investigate the influence of transcription and translation on the segregation of recombinant plasmids designed for constitutive gene expression in <it>Escherichia coli </it>LE392 at glucose-limited continuous cultivation. To this end a series of pBR322-based plasmids carrying a synthetic human interferon-gamma (hIFNγ) gene placed under the control of different regulatory elements (promoter and ribosome-binding sites) were used as a model.</p> <p>Results</p> <p>Bacterial growth and product formation kinetics of transformed <it>E. coli </it>LE392 cells cultivated continuously were described by a structured kinetic model proposed by Lee et al. (1985). The obtained results demonstrated that both transcription and translation efficiency strongly affected plasmid segregation. The segregation of plasmid having a deleted promoter did not exceed 5% after 190 h of cultivation. The observed high plasmid stability was not related with an increase in the plasmid copy-number. A reverse correlation between the yield of recombinant protein (as modulated by using different ribosome binding sites) and segregational plasmid stability (determined by the above model) was also observed.</p> <p>Conclusions</p> <p>Switching-off transcription of the hIFNγ gene has a stabilising effect on ColE1-like plasmids against segregation, which is not associated with an increase in the plasmid copy-number. The increased constitutive gene expression has a negative effect on segregational plasmid stability. A kinetic model proposed by Lee et al. (1985) was appropriate for description of <it>E. coli </it>cell growth and recombinant product formation in chemostat cultivations.</p
Serum levels of osteoprotegerin and receptor activator of nuclear factor -κB ligand in children with early juvenile idiopathic arthritis: a 2-year prospective controlled study
<p>Abstract</p> <p>Background</p> <p>The clinical relevance of observations of serum levels of osteoprotegerin (OPG) and receptor activator of nuclear factor -κB ligand (RANKL) in juvenile idiopathic arthritis (JIA) is not clear. To elucidate the potential role of OPG and RANKL in JIA we determined serum levels of OPG and RANKL in patients with early JIA compared to healthy children, and prospectively explored changes in relation to radiographic score, bone and lean mass, severity of the disease, and treatment.</p> <p>Methods</p> <p>Ninety children with early oligoarticular or polyarticular JIA (ages 6-18 years; mean disease duration 19.4 months) and 90 healthy children individually matched for age, sex, race, and county of residence, were examined at baseline and 2-year follow-up. OPG and RANKL were quantified by enzyme-immunoassay. Data were analyzed with the use of t-tests, ANOVA, and multiple regression analyses.</p> <p>Results</p> <p>Serum OPG was significantly lower in patients than controls at baseline, and there was a trend towards higher RANKL and a lower OPG/RANKL ratio. Patients with polyarthritis had significantly higher increments in RANKL from baseline to follow-up, compared to patients with oligoarthritis. RANKL was a significant negative predictor for increments in total body lean mass. Patients who were receiving corticosteroids (CS) or disease-modifying antirheumatic drugs (DMARDs) at follow-up had higher OPG/RANKL ratio compared with patients who did not receive this medication.</p> <p>Conclusions</p> <p>The data supports that levels of OPG are lower in patients with JIA compared to healthy children, and higher levels of RANKL is associated with more serious disease. RANKL was a significant negative predictor of lean mass in patients with JIA. The OPG/RANKL ratio was higher in patients on DMARDs or CS treatment.</p
Sex-specific regulation of chemokine Cxcl5/6 controls neutrophil recruitment and tissue injury in acute inflammatory states
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Barts and The London Trustees Studentship (SM), Marie Curie fellowships (MB, JD), Arthritis Research UK career development fellowship (JW), William Harvey Research Foundation grant (JW/RSS), Kidney Research UK fellowship (NSAP), Barts and The London Vacation Scholarship (ISN), Wellcome Trust senior fellowship (DWG), and a Wellcome Trust career development fellowship (RSS). This work forms part of the research themes contributing to the translational research portfolio of Barts and The London Cardiovascular Biomedical Research Unit, which is supported and funded by National Institute for Health Researc
- …