214 research outputs found
Immediate thoracotomy for penetrating injuries: Ten years' experience at a Dutch level I trauma center
Background: An emergency department thoracotomy (EDT) or an emergency thoracotomy (ET) in the operating theater are both beneficial in selected patients following thoracic penetrating injuries. Since outcome-descriptive European studies are lacking, the aim of this retrospective study was to evaluate ten years of experience at a Dutch level I trauma center. Method: Data on patients who underwent an immediate thoracotomy after sustaining a penetrating thoracic injury between October 2000 and January 2011 were collected from the trauma registry and hospital files. Descriptive and univariate analyses were performed. Results: Among 56 patients, 12 underwent an EDT and 44 an ET. Forty-six patients sustained one or multiple stab wounds, versus ten with one or multiple gunshot wounds. Patients who had undergone an EDT had a lower GCS (p < 0. 001), lower pre-hospital RTS and hospital triage RTS (p < 0. 001 and p = 0. 009, respectively), and a lower SBP (p = 0. 038). A witnessed loss of signs of life generally occurred in EDT patients and was accompanied by 100 % mortality. Survival following EDT was 25 %, which was significantly lower than in the ET group (75 %; p = 0. 002). Survivors had lower ISS (p = 0. 011), lower rates of pre-hospital (p = 0. 031) and hospital (p = 0. 003) hemodynamic instability, and a lower prevalence of concomitant abdominal injury (p = 0. 002). Conclusion: The overall survival rate in our study was 64 %. The outcome of immediate thoracotomy performed in this level I trauma center was similar to those obtained in high-incidence regions like the US and South Africa. This suggests that trauma units where immediate thoracotomies are not part of the daily routine can achieve similar results, if properly trained
The RESPITE trial: remifentanil intravenously administered patient-controlled analgesia (PCA) versus pethidine intramuscular injection for pain relief in labour: study protocol for a randomised controlled trial
Background
The commonest opioid used for pain relief in labour is pethidine (meperidine); however, its effectiveness has long been challenged and the drug has known side effects including maternal sedation, nausea and potential transfer across the placenta to the foetus. Over a third of women receiving pethidine require an epidural due to inadequate pain relief. Epidural analgesia increases the risk of an instrumental vaginal delivery and its associated effects. Therefore, there is a clear need for a safe, effective, alternative analgesic to pethidine. Evidence suggests that remifentanil patient-controlled analgesia (PCA) reduces epidural conversion rates compared to pethidine; however, no trial has yet investigated this as a primary endpoint. We are, therefore, comparing pethidine intramuscular injection to remifentanil PCA in a randomised controlled trial.
Methods/design
Women in established labour, requesting systemic opioid pain relief, will be randomised to either intravenously administered remifentanil PCA (intervention) or pethidine intramuscular injection (control) in an unblinded, 1:1 individual randomised trial.
Following informed consent, 400 women in established labour, who request systemic opioid pain relief, from NHS Trusts across England will undergo a minimised randomisation by a computer or automated telephone system to either pethidine or remifentanil. In order to balance the groups this minimisation is based on four parameters; parity (nulliparous versus multiparous), maternal age (<20, 20 < 30, 30 < 40, 40+ years), ethnicity (South Asian (Pakistani/Indian/Bangladeshi) versus Other) and induced versus spontaneous labour.
The effectiveness of pain relief provided by each technique will be recorded every 30 min after time zero, until epidural placement, delivery or transfer to theatre, quantified by Visual Analogue Scale. Incidence of maternal side effects including sedation, delivery mode, foetal distress requiring delivery, neonatal status at delivery and rate of initiation of breastfeeding within the first hour of birth will also be recorded.
Maternal satisfaction with her childbirth experience will be determined by a postpartum questionnaire prior to discharge from the delivery ward.
Discussion
The RESPITE trial’s primary outcome is the proportion of women who have an epidural placed for pain relief in labour in each arm.
Trial Registration
Current Controlled Trials registration number: ISRCTN29654603. Registered on 23 July 2013
Foliar δ15N values characterize soil N cycling and reflect nitrate or ammonium preference of plants along a temperate grassland gradient
The natural abundance of stable 15N isotopes in soils and plants is potentially a simple tool to assess ecosystem N dynamics. Several open questions remain, however, in particular regarding the mechanisms driving the variability of foliar δ15N values of non-N2 fixing plants within and across ecosystems. The goal of the work presented here was therefore to: (1) characterize the relationship between soil net mineralization and variability of foliar Δδ15N (δ15Nleaf − δ15Nsoil) values from 20 different plant species within and across 18 grassland sites; (2) to determine in situ if a plant’s preference for NO3− or NH4+ uptake explains variability in foliar Δδ15N among different plant species within an ecosystem; and (3) test if variability in foliar Δδ15N among species or functional group is consistent across 18 grassland sites. Δδ15N values of the 20 different plant species were positively related to soil net mineralization rates across the 18 sites. We found that within a site, foliar Δδ15N values increased with the species’ NO3− to NH4+ uptake ratios. Interestingly, the slope of this relationship differed in direction from previously published studies. Finally, the variability in foliar Δδ15N values among species was not consistent across 18 grassland sites but was significantly influenced by N mineralization rates and the abundance of a particular species in a site. Our findings improve the mechanistic understanding of the commonly observed variability in foliar Δδ15N among different plant species. In particular we were able to show that within a site, foliar δ15N values nicely reflect a plant’s N source but that the direction of the relationship between NO3− to NH4+ uptake and foliar Δδ15N values is not universal. Using a large set of data, our study highlights that foliar Δδ15N values are valuable tools to assess plant N uptake patterns and to characterize the soil N cycle across different ecosystems
Microarray-Based Maps of Copy-Number Variant Regions in European and Sub-Saharan Populations
The genetic basis of phenotypic variation can be partially explained by the presence of copy-number variations (CNVs). Currently available methods for CNV assessment include high-density single-nucleotide polymorphism (SNP) microarrays that have become an indispensable tool in genome-wide association studies (GWAS). However, insufficient concordance rates between different CNV assessment methods call for cautious interpretation of results from CNV-based genetic association studies. Here we provide a cross-population, microarray-based map of copy-number variant regions (CNVRs) to enable reliable interpretation of CNV association findings. We used the Affymetrix Genome-Wide Human SNP Array 6.0 to scan the genomes of 1167 individuals from two ethnically distinct populations (Europe, N = 717; Rwanda, N = 450). Three different CNV-finding algorithms were tested and compared for sensitivity, specificity, and feasibility. Two algorithms were subsequently used to construct CNVR maps, which were also validated by processing subsamples with additional microarray platforms (Illumina 1M-Duo BeadChip, Nimblegen 385K aCGH array) and by comparing our data with publicly available information. Both algorithms detected a total of 42669 CNVs, 74% of which clustered in 385 CNVRs of a cross-population map. These CNVRs overlap with 862 annotated genes and account for approximately 3.3% of the haploid human genome
NLRP12 attenuates colon inflammation by maintaining colonic microbial diversity and promoting protective commensal bacterial growth
Inflammatory bowel diseases involve the dynamic interplay of host genetics, microbiome and inflammatory response. Here, we report that NLRP12, a negative regulator of innate immunity, is reduced in human ulcerative colitis by comparing monozygotic twins and other patient cohorts. In parallel, Nlrp12-deficiency in mice caused increased colonic basal inflammation, leading to a less-diverse microbiome, loss of protective gut commensal strains (Lachnospiraceae) and increased colitogenic strains (Erysipelotrichaceae). Dysbiosis and colitis susceptibility associated with Nlrp12-deficency were reversed equally by treatment with antibodies targeting inflammatory cytokines or by administration of beneficial commensal Lachnospiraceae isolates. Fecal transplants from specific pathogen free reared mice into germ-free Nlrp12-deficient mice showed that NLRP12 and the microbiome each contribute to immune signaling that culminates in colon inflammation. These findings reveal a feed-forward loop where NLRP12 promotes specific commensals that can reverse gut inflammation, while cytokine blockade during NLRP12-deficiency can reverse dysbiosis
Knowledge ‘Translation’ as Social Learning: Negotiating the Uptake of Research-Based Knowledge in Practice
BACKGROUND: Knowledge translation and evidence-based practice have relied on research derived from clinical trials, which are considered to be methodologically rigorous. The result is practice recommendations based on a narrow view of evidence. We discuss how, within a practice environment, in fact individuals adopt and apply new evidence derived from multiple sources through ongoing, iterative learning cycles.
DISCUSSION: The discussion is presented in four sections. After elaborating on the multiple forms of evidence used in practice, in section 2 we argue that the practitioner derives contextualized knowledge through reflective practice. Then, in section 3, the focus shifts from the individual to the team with consideration of social learning and theories of practice. In section 4 we discuss the implications of integrative and negotiated knowledge exchange and generation within the practice environment. Namely, how can we promote the use of research within a team-based, contextualized knowledge environment? We suggest support for: 1) collaborative learning environments for active learning and reflection, 2) engaged scholarship approaches so that practice can inform research in a collaborative manner and 3) leveraging authoritative opinion leaders for their clinical expertise during the shared negotiation of knowledge and research. Our approach also points to implications for studying evidence-informed practice: the identification of practice change (as an outcome) ought to be supplemented with understandings of how and when social negotiation processes occur to achieve integrated knowledge.
SUMMARY: This article discusses practice knowledge as dependent on the practice context and on social learning processes, and suggests how research knowledge uptake might be supported from this vantage point
Histamine Derived from Probiotic Lactobacillus reuteri Suppresses TNF via Modulation of PKA and ERK Signaling
Beneficial microbes and probiotic species, such as Lactobacillus reuteri, produce biologically active compounds that can modulate host mucosal immunity. Previously, immunomodulatory factors secreted by L. reuteri ATCC PTA 6475 were unknown. A combined metabolomics and bacterial genetics strategy was utilized to identify small compound(s) produced by L. reuteri that were TNF-inhibitory. Hydrophilic interaction liquid chromatography-high performance liquid chromatography (HILIC-HPLC) separation isolated TNF-inhibitory compounds, and HILIC-HPLC fraction composition was determined by NMR and mass spectrometry analyses. Histamine was identified and quantified in TNF-inhibitory HILIC-HPLC fractions. Histamine is produced from L-histidine via histidine decarboxylase by some fermentative bacteria including lactobacilli. Targeted mutagenesis of each gene present in the histidine decarboxylase gene cluster in L. reuteri 6475 demonstrated the involvement of histidine decarboxylase pyruvoyl type A (hdcA), histidine/histamine antiporter (hdcP), and hdcB in production of the TNF-inhibitory factor. The mechanism of TNF inhibition by L. reuteri-derived histamine was investigated using Toll-like receptor 2 (TLR2)-activated human monocytoid cells. Bacterial histamine suppressed TNF production via activation of the H2 receptor. Histamine from L. reuteri 6475 stimulated increased levels of cAMP, which inhibited downstream MEK/ERK MAPK signaling via protein kinase A (PKA) and resulted in suppression of TNF production by transcriptional regulation. In summary, a component of the gut microbiome, L. reuteri, is able to convert a dietary component, L-histidine, into an immunoregulatory signal, histamine, which suppresses pro-inflammatory TNF production. The identification of bacterial bioactive metabolites and their corresponding mechanisms of action with respect to immunomodulation may lead to improved anti-inflammatory strategies for chronic immune-mediated diseases
Planck intermediate results: LVII. Joint Planck LFI and HFI data processing
We present the NPIPE processing pipeline, which produces calibrated frequency maps in temperature and polarization from data from the Planck
Low Frequency Instrument (LFI) and High Frequency Instrument (HFI) using high-performance computers. NPIPE represents a natural evolution
of previous Planck analysis efforts, and combines some of the most powerful features of the separate LFI and HFI analysis pipelines. For example,
following the LFI 2018 processing procedure, NPIPE uses foreground polarization priors during the calibration stage in order to break scanninginduced degeneracies. Similarly, NPIPE employs the HFI 2018 time-domain processing methodology to correct for bandpass mismatch at all
frequencies. In addition, NPIPE introduces several improvements, including, but not limited to: inclusion of the 8% of data collected during
repointing manoeuvres; smoothing of the LFI reference load data streams; in-flight estimation of detector polarization parameters; and construction
of maximally independent detector-set split maps. For component-separation purposes, important improvements include: maps that retain the CMB
Solar dipole, allowing for high-precision relative calibration in higher-level analyses; well-defined single-detector maps, allowing for robust CO
extraction; and HFI temperature maps between 217 and 857 GHz that are binned into 0.09 pixels (Nside = 4096), ensuring that the full angular
information in the data is represented in the maps even at the highest Planck resolutions. The net effect of these improvements is lower levels of
noise and systematics in both frequency and component maps at essentially all angular scales, as well as notably improved internal consistency
between the various frequency channels. Based on the NPIPE maps, we present the first estimate of the Solar dipole determined through component
separation across all nine Planck frequencies. The amplitude is (3366.6 ± 2.7) µK, consistent with, albeit slightly higher than, earlier estimates.
From the large-scale polarization data, we derive an updated estimate of the optical depth of reionization of τ = 0.051 ± 0.006, which appears
robust with respect to data and sky cuts. There are 600 complete signal, noise and systematics simulations of the full-frequency and detector-set
maps. As a Planck first, these simulations include full time-domain processing of the beam-convolved CMB anisotropies. The release of NPIPE
maps and simulations is accompanied with a complete suite of raw and processed time-ordered data and the software, scripts, auxiliary data, and
parameter files needed to improve further on the analysis and to run matching simulations
Amyloids - A functional coat for microorganisms
Amyloids are filamentous protein structures ~10 nm wide and 0.1–10 µm long that share a structural motif, the cross-β structure. These fibrils are usually associated with degenerative diseases in mammals. However, recent research has shown that these proteins are also expressed on bacterial and fungal cell surfaces. Microbial amyloids are important in mediating mechanical invasion of abiotic and biotic substrates. In animal hosts, evidence indicates that these protein structures also contribute to colonization by activating host proteases that are involved in haemostasis, inflammation and remodelling of the extracellular matrix. Activation of proteases by amyloids is also implicated in modulating blood coagulation, resulting in potentially life-threatening complications.
Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial
Background:
Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events.
Methods:
The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627).
Findings:
Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29–146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0– 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25–1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39–1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65–1·60]; p=0·92).
Interpretation:
These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention
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