127 research outputs found
The efficacy and safety of closure of brachial access using the AngioSeal closure device: Experience with 161 interventions in diabetic patients with critical limb ischemia
PurposeThis study retrospectively evaluated the efficacy and safety of the 6F Angio-Seal (St. Jude Medical, St. Paul, Minn) as a closure device for transbrachial artery access for endovascular procedures in diabetic patients with critical limb ischemia.MethodsFrom January 2005 and September 2007, 1887 diabetic patients underwent interventional procedures in the lower limbs at a two diabetic foot centers. Patients presented with rest pain (16%), ulcers (80%), or gangrene (4%). Systemic anticoagulation with sodium heparin (70 IU/kg) was obtained for all patients at the beginning of the endovascular treatment. A total of 249 brachial arteries (238 patients) were evaluated for possible Angio-Seal use after endovascular recanalization of the leg. Color Doppler ultrasound imaging of the artery was obtained before revascularization only in patients with previous Angio-Seal placement in the brachial artery. No further imaging studies were done in the remaining brachial arteries where the Angio-Seal was deployed at the operator’s discretion. Impairment or disappearance of the radial pulse or onsets of hand ischemia or hand pain, or impairment of hand function during or at the end of the endovascular revascularization were all regarded as contraindications to Angio-Seal usage. Evidence of a highly calcified plaque of the brachial artery access site at the time of vessel puncture was regarded as an absolute contraindication to the Angio-Seal use. Patients were seen before discharge, at 1, 3, and 8 weeks after the procedure, and at 3-month intervals thereafter. Complications included hemorrhage, pseudoaneurysm, infection, and vessel occlusion.ResultsA total of 1947 Angio-Seal collagen plugs were deployed in 1709 diabetic patients (90.5%). The Angio-Seal was used for brachial artery closure in 159 patients (8.4%) in 161 procedures (159 in the left, 2 in the right brachial artery). In 79 patients (4.2%) in 88 procedures (87 in the left and 1 in the right brachial artery), the device was deemed contraindicated due to small vessel size in 73 patients (92.4%) or presence of calcium at the access site in five patients (6.3%). One patient (1.3%) refused the collagen plug closure after revascularization. The non-Angio-Seal group was evaluated for comparison. The success rate for achieving hemostasis in the Angio-Seal group was 96.9%. Five major complications (3.1%) at 30 days consisted of two puncture site hematomas >4 cm, two brachial artery occlusions, and one brachial artery pseudoaneurysm, with three patients requiring open surgery. Minor complications (7.50%) were three puncture site hematomas < 4 cm, three oozing of blood from the access site, and six patients had mild pain in the cubital fossa. No further complications were recorded in the 14-month follow-up (range 1-25 months) of a total of 140 patients.ConclusionsThis retrospective study shows that the 6F Angio-Seal is a valuable and safe vascular closure device for transbrachial access in diabetic patients undergoing interventional procedures for critical limb ischemia
Prasinovirus distribution in the Northwest Mediterranean Sea is affected by the environment and particularly by phosphate availability
AbstractNumerous seawater lagoons punctuate the southern coastline of France. Exchanges of seawater between these lagoons and the open sea are limited by narrow channels connecting them. Lagoon salinities vary according to evaporation and to the volume of freshwater arriving from influent streams, whose nutrients also promote the growth of algae. We compared Prasinovirus communities, whose replication is supported by microscopic green algae, in four lagoons and at a coastal sampling site. Using high-throughput sequencing of DNA from a giant virus-specific marker gene, we show that the environmental conditions significantly affect the types of detectable viruses across samples. In spatial comparisons between 5 different sampling sites, higher levels of phosphates, nitrates, nitrites, ammonium and silicates tend to increase viral community richness independently of geographical distances between the sampling sites. Finally, comparisons of Prasinovirus communities at 2 sampling sites over a period of 10 months highlighted seasonal effects and the preponderant nature of phosphate concentrations in constraining viral distribution
Supporting Early-Safety Analysis of IoT Systems by Exploiting Testing Techniques
IoT systems complexity and susceptibility to failures pose significant
challenges in ensuring their reliable operation Failures can be internally
generated or caused by external factors impacting both the systems correctness
and its surrounding environment To investigate these complexities various
modeling approaches have been proposed to raise the level of abstraction
facilitating automation and analysis FailureLogic Analysis FLA is a technique
that helps predict potential failure scenarios by defining how a components
failure logic behaves and spreads throughout the system However manually
specifying FLA rules can be arduous and errorprone leading to incomplete or
inaccurate specifications In this paper we propose adopting testing
methodologies to improve the completeness and correctness of these rules How
failures may propagate within an IoT system can be observed by systematically
injecting failures while running test cases to collect evidence useful to add
complete and refine FLA rule
Deep sequencing of amplified Prasinovirus and host green algal genes from an Indian Ocean transect reveals interacting trophic dependencies and new genotypes
International audienceHigh-throughput sequencing of Prasinovirus DNA polymerase and host green algal (Mamiellophyceae) ribosomal RNA genes was used to analyse the diversity and distribution of these taxa over a ∼10 000 km latitudinal section of the Indian Ocean. New viral and host groups were identified among the different trophic conditions observed, and highlighted that although unknown prasinoviruses are diverse, the cosmopolitan algal genera Bathycoccus, Micromonas and Ostreococcus represent a large proportion of the host diversity. While Prasinovirus communities were correlated to both the geography and the environment, host communities were not, perhaps because the genetic marker used lacked sufficient resolution. Nevertheless, analysis of single environmental variables showed that eutrophic conditions strongly influence the distributions of both hosts and viruses. Moreover, these communities were not correlated, in their composition or specific richness. These observations could result from antagonistic dynamics, such as that illustrated in a prey–predator model, and/or because hosts might be under a complex set of selective pressures. Both of these reasons must be considered to interpret environmental surveys of viruses and hosts, because covariation does not always imply interaction
Exploring nucleo-cytoplasmic large DNA viruses in Tara Oceans microbial metagenomes
Nucleo-cytoplasmic large DNA viruses (NCLDVs) constitute a group of eukaryotic viruses that can have crucial ecological roles in the sea by accelerating the turnover of their unicellular hosts or by causing diseases in animals. To better characterize the diversity, abundance and biogeography of marine NCLDVs, we analyzed 17 metagenomes derived from microbial samples (0.2–1.6 μm size range) collected during the Tara Oceans Expedition. The sample set includes ecosystems under-represented in previous studies, such as the Arabian Sea oxygen minimum zone (OMZ) and Indian Ocean lagoons. By combining computationally derived relative abundance and direct prokaryote cell counts, the abundance of NCLDVs was found to be in the order of 104–105 genomes ml−1 for the samples from the photic zone and 102–103 genomes ml−1 for the OMZ. The Megaviridae and Phycodnaviridae dominated the NCLDV populations in the metagenomes, although most of the reads classified in these families showed large divergence from known viral genomes. Our taxon co-occurrence analysis revealed a potential association between viruses of the Megaviridae family and eukaryotes related to oomycetes. In support of this predicted association, we identified six cases of lateral gene transfer between Megaviridae and oomycetes. Our results suggest that marine NCLDVs probably outnumber eukaryotic organisms in the photic layer (per given water mass) and that metagenomic sequence analyses promise to shed new light on the biodiversity of marine viruses and their interactions with potential hosts
Long-Term Prognosis of Diabetic Patients With Critical Limb Ischemia: A population-based cohort study
OBJECTIVE\u2014 To evaluate the long-term prognosis of critical limb ischemia (CLI) in diabetic
patients.
RESEARCH DESIGN AND METHODS\u2014 A total of 564 consecutive diabetic patients
were hospitalized for CLI from January 1999 to December 2003; 554 were followed until
December 2007.
RESULTS\u2014 The mean follow-up was 5.93 1.28 years. Peripheral angioplasty (PTA) was
performed in 420 (74.5%) and bypass graft (BPG) in 117 (20.6%) patients. Neither PTA nor BPG
were possible in 27 (4.9%) patients. Major amputations were performed in 74 (13.4%) patients:
34 (8.2%) in PTA, 24 (21.1%) in BPG, and 16 (59.2%) in a group that received no revascularization.
Restenosis occurred in 94 patients, bypass failures in 36 patients, and recurrent ulcers in
71 patients. CLI was observed in the contralateral limb of 225 (39.9%) patients; of these, 15
(6.7%) required major amputations (rate in contralateral compared with initial limb, P 0.007).
At total of 276 (49.82%) patients died. The Cox model showed significant hazard ratios (HRs) for
mortality with age (1.05 for 1 year [95% CI 1.03\u20131.07]), unfeasible revascularization (3.06
[1.40\u20136.70]), dialysis (3.00 [1.63\u20135.53]), cardiac disease history (1.37 [1.05\u20131.79]), and impaired
ejection fraction (1.08 for 1% point [1.05\u20131.09]).
CONCLUSIONS\u2014 Diabetic patients with CLI have high risks of amputation and death. In
a dedicated diabetic foot center, the major amputation, ulcer recurrence, and major contralateral
limb amputation rates were low. Coronary artery disease (CAD) is the leading cause of death, and
in patients with CAD history the impaired ejection fraction is the major independent prognostic
factor
Evolutionary consequences of viral resistance in the marine picoeukaryote Ostreococcus tauri
In marine environments, eukaryotic marine microalgae coexist with the viruses that
infect them. Marine microalgae are the main primary producers in the oceans and are
at the base of the marine food web. Viruses play important roles in top-down control
of algae populations, cycling of organic matter, and as evolutionary drivers of their
hosts. Algae must adapt in response to the strong selection pressure that viruses
impose for resistance to infection. In addition to biotic selection pressures such as
viral infections, algae must also adapt to their abiotic environment. Global climate
change is affecting temperature, salinity, pH, light and nutrient concentrations in the
oceans, particularly in surface waters, where microalgae live. Currently, little is
known about how consistent the effects of viruses on their hosts are, whether the cost
of host resistance varies across environments, and whether there is a trade-off
between maintaining resistance to viruses and adapting to other environmental
changes.
The marine picoeukaryote Ostreococcus tauri is abundant in Mediterranean lagoons,
where it experiences large fluctuations in environmental conditions and co-occurs
with lytic viruses (Ostreococcus tauri viruses – OtVs). Viral infection causes lysis of
susceptible (S) cells, however a small proportion of cells are resistant (R) and avoid
lysis. Some resistant O. tauri populations can coexist with infectious viruses, and it
has been proposed that these viruses are produced by a minority of susceptible cells
within a mainly resistant population. These populations are referred to as resistant
producers (RP). Virus production in RP populations is unstable and eventually they
shift to R populations. I used O. tauri and one of its viruses, OtV5, as a model
system to investigate whether cells that are susceptible or resistant to virus infection
adapt to environmental change differently and whether there is a cost of being
resistant.
For the first time, I evolved susceptible and resistant hosts of a marine alga
separately under a range of environments and directly compared their plastic and
evolved responses. I showed that resistant populations of O. tauri maintained their
resistance for more than 200 generations in the absence of viruses across all
environments, indicating that the resistance mechanism is difficult to reverse.
Furthermore, I did not detect a cost of being resistant, as measured by population
growth rate and competitive ability. Virus production in RP populations stopped in
all environments and all populations became R.
In addition, I found that virus production in RP O. tauri populations can fluctuate
before completely ceasing, and that phosphate affected the length of time it took for
virus production to stop. These results, combined with mathematical modelling of O.
tauri infection dynamics, provide support for the prediction that RP populations
consist of a mixed population of susceptible and resistant cells.
By examining multiple environments and resistance types, we can better understand
first, how microalgae populations adapt to environmental change and second, the
ecological and evolutionary consequences of maintaining resistance to viruses in
common marine picoeukaryotes
Recruitment of a lineage-specific virulence regulatory pathway promotes intracellular infection by a plant pathogen experimentally evolved into a legume symbiont
Ajuts: We are grateful to Lidwine Trouilh for helping in NimbleGen microarray hybridizations and Loic Escoriza for mutant construction. J.P.C. and C.C. were supported by the Initiative d'Excellence IDEX UNITI Actions Thématiques Stratégiques program (RHIZOWHEAT 2014) and by the French National Research Agency (ANR-12-ADAP-0014-01). This work was supported by funds from the French National Institute for Agricultural Research (Plant Health and the Environment Division), the French National Research Agency (ANR-12-ADAP-0014-01) and the French Laboratory of Excellence project TULIP (ANR-10-LABX-41). The complete collections of events generated for all the clones from this study are available on the Microscope platform (https://www.genoscope.cns.fr/agc/microscope/expdata/NGSProjectEvo.php, SYMPA tag).Ecological transitions between different lifestyles, such as pathogenicity, mutualism and saprophytism, have been very frequent in the course of microbial evolution, and often driven by horizontal gene transfer. Yet, how genomes achieve the ecological transition initiated by the transfer of complex biological traits remains poorly known. Here we used experimental evolution, genomics, transcriptomics and high-resolution phenotyping to analyze the evolution of the plant pathogen Ralstonia solanacearum into legume symbionts, following the transfer of a natural plasmid encoding the essential mutualistic genes. We show that a regulatory pathway of the recipient R. solanacearum genome involved in extracellular infection of natural hosts was reused to improve intracellular symbiosis with the Mimosa pudica legume. Optimization of intracellular infection capacity was gained through mutations affecting two components of a new regulatory pathway, the transcriptional regulator efpR and a region upstream from the RSc0965-0967 genes of unknown functions. Adaptive mutations caused the downregulation of efpR and the over-expression of a downstream regulatory module, the three unknown genes RSc3146-3148, two of which encoding proteins likely associated to the membrane. This over-expression led to important metabolic and transcriptomic changes and a drastic qualitative and quantitative improvement of nodule intracellular infection. In addition, these adaptive mutations decreased the virulence of the original pathogen. The complete efpR/RSc3146-3148 pathway could only be identified in the genomes of the pathogenic R. solanacearum species complex. Our findings illustrate how the rewiring of a genetic network regulating virulence allows a radically different type of symbiotic interaction and contributes to ecological transitions and trade-offs
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Evolutionary timeline and genomic plasticity underlying the lifestyle diversity in rhizobiales
Members of the order include those capable of nitrogen fixation in nodules as well as pathogens of animals and plants. This lifestyle diversity has important implications for agricultural and medical research. Leveraging large-scale genomic data, we infer that originated as a free-living ancestor ∼1,500 million years ago (Mya) and that the later emergence of host-associated lifestyles broadly coincided with the rise of their eukaryotic hosts. In particular, the first nodulating lineage arose from either or 150 to 80 Mya, a time range in general concurrent with the emergence of legumes. The rates of lifestyle transitions are highly variable; nodule association is more likely to be lost than gained, whereas animal association likely represents an evolutionary dead end. We searched for statistical correlations between gene presence and lifestyle and identified genes likely contributing to the transition and adaptation to the same lifestyle in divergent lineages. Among the genes potentially promoting successful transitions to major nodulation lineages, the and clusters for nodulation and nitrogen fixation, respectively, were repeatedly acquired during each transition; the , , and clusters involved in energy conservation under micro-oxic conditions were present in the nonnodulating ancestors; and the secretion systems were acquired in lineage-specific patterns. Our study data suggest that increased eukaryote diversity drives lifestyle diversification of bacteria and highlight both acquired and preexisting traits facilitating the origin of host association. Bacteria form diverse interactions with eukaryotic hosts. This is well represented by the , a clade of strategically important for their large diversity of lifestyles with implications for agricultural and medical research. To investigate their lifestyle evolution, we compiled a comprehensive data set of genomes and lifestyle information for over 1,000 genomes. We show that the origins of major host-associated lineages in broadly coincided with the emergences of their host plants/animals, suggesting bacterium-host interactions as a driving force in the evolution of We further found that, in addition to gene gains, preexisting traits and recurrent losses of specific genomic traits may have played underrecognized roles in the origin of host-associated lineages, providing clues to genetic engineering of microbial agricultural inoculants and prevention of the emergence of potential plant/animal pathogens
A set of empirically validated development guidelines for improving Node-RED flows comprehension
Internet of Things (IoT) systems are rapidly gaining importance in the human society, providing a variety of services to improve the quality of our lives, involving complex and safety-critical tasks; therefore, assuring their quality is of paramount importance. Node-RED is a Web-based visual tool inspired by the flow-based programming paradigm, built on Node.js, and recently emerged to support the users in developing IoT systems in a simple manner. The community behind Node-RED is quite active and encourages artefacts sharing. Thus, the Node-RED flows developed and submitted to public usages should be easy to comprehend and integrate within already existing systems, also in preparation of future maintenance and testing activities. Unfortunately, no consolidated approaches or guidelines to develop comprehensible Node-RED flows currently exist. In this paper, we propose a set of guidelines to help the Node-RED developers in producing flows that are easy to comprehend and use. We have designed and conducted an experiment to evaluate the effect of the guidelines in Node-RED flows comprehension. Results show that the adoption of the guidelines significantly reduces the number of errors (p-value = 0.00903) and the time required to comprehend Node-RED flows (p-value = 0.04883)
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