| 1. |
- Abate, E., et al.
(författare)
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Combined performance tests before installation of the ATLAS Semiconductor and Transition Radiation Tracking Detectors
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3
-
Tidskriftsartikel (refereegranskat)abstract
- The ATLAS (A Toroidal LHC ApparatuS) Inner Detector provides charged particle tracking in the centre of the ATLAS experiment at the Large Hadron Collider (LHC). The Inner Detector consists of three subdetectors: the Pixel Detector, the Semiconductor Tracker (SCT), and the Transition Radiation Tracker (TRT). This paper summarizes the tests that were carried out at the final stage of SCT+TRT integration prior to their installation in ATLAS. The combined operation and performance of the SCT and TRT barrel and endcap detectors was investigated through a series of noise tests, and by recording the tracks of cosmic rays. This was a crucial test of hardware and software of the combined tracker detector systems. The results of noise and cross-talk tests on the SCT and TRT in their final assembled configuration, using final readout and supply hardware and software, are reported. The reconstruction and analysis of the recorded cosmic tracks allowed testing of the offline analysis chain and verification of basic tracker performance parameters, such as efficiency and spatial resolution, in combined operation before installation.
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| 2. |
- Abdesselam, A., et al.
(författare)
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The ATLAS semiconductor tracker end-cap module
- 2007
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 575:3, s. 353-389
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Tidskriftsartikel (refereegranskat)abstract
- The challenges for the tracking detector systems at the LHC are unprecedented in terms of the number of channels, the required read-out speed and the expected radiation levels. The ATLAS Semiconductor Tracker. (SCT) end-caps have a total of about 3 million electronics channels each reading out every 25 ns into its own on-chip 3.3 mu s buffer. The highest anticipated dose after 10 years operation is 1.4x10(14) cm(-2) in units of 1 MeV neutron equivalent (assuming the damage factors scale with the non-ionising energy loss). The forward tracker has 1976 double-sided modules, mostly of area similar to 70 cm(2), each having 2 x 768 strips read out by six ASICs per side. The requirement to achieve an average perpendicular radiation length of 1.5% X-0, while coping with up to 7 W dissipation per module (after irradiation), leads to stringent constraints on the thermal design. The additional requirement of 1500e(-) equivalent noise charge (ENC) rising to only 1800e(-) ENC after irradiation, provides stringent design constraints on both the high-density Cu/Polyimide flex read-out circuit and the ABCD3TA read-out ASICs. Finally, the accuracy of module assembly must not compromise the 16 mu m (r phi) resolution perpendicular to the strip directions or 580 mu m radial resolution coming from the 40 mrad front-back stereo angle. A total of 2210 modules were built to the tight tolerances and specifications required for the SCT. This was 234 more than the 1976 required and represents a yield of 93%. The component flow was at times tight, but the module production rate of 40-50 per week was maintained despite this. The distributed production was not found to be a major logistical problem and it allowed additional flexibility to take advantage of where the effort was available, including any spare capacity, for building the end-cap modules. The collaboration that produced the ATLAS SCT end-cap modules kept in close contact at all times so that the effects of shortages or stoppages at different sites could be rapidly resolved.
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| 3. |
- Abat, E., et al.
(författare)
-
The ATLAS TRT end-cap detectors
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3
-
Tidskriftsartikel (refereegranskat)abstract
- The ATLAS TRT end-cap is a tracking drift chamber using 245,760 individual tubular drift tubes. It is a part of the TRT tracker which consist of the barrel and two end-caps. The TRT end-caps cover the forward and backward pseudo-rapidity region 1.0 < vertical bar eta vertical bar < 2.0, while the TRT barrel central eta region vertical bar eta vertical bar < 1.0. The TRT system provides a combination of continuous tracking with many measurements in individual drift tubes ( or straws) and of electron identification based on transition radiation from fibers or foils interleaved between the straws themselves. Along with other two sub-systems, namely the Pixel detector and Semi Conductor Tracker (SCT), the TRT constitutes the ATLAS Inner Detector. This paper describes the recently completed and installed TRT end-cap detectors, their design, assembly, integration and the acceptance tests applied during the construction.
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| 4. |
- Abat, E., et al.
(författare)
-
The ATLAS TRT barrel detector
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3
-
Tidskriftsartikel (refereegranskat)abstract
- The ATLAS TRT barrel is a tracking drift chamber using 52,544 individual tubular drift tubes. It is one part of the ATLAS Inner Detector, which consists of three sub-systems: the pixel detector spanning the radius range 4 to 20 cm, the semiconductor tracker (SCT) from 30 to 52 cm, and the transition radiation tracker ( TRT) from 56 to 108 cm. The TRT barrel covers the central pseudo-rapidity region |eta| < 1, while the TRT endcaps cover the forward and backward eta regions. These TRT systems provide a combination of continuous tracking with many measurements in individual drift tubes ( or straws) and of electron identification based on transition radiation from fibers or foils interleaved between the straws themselves. This paper describes the recently-completed construction of the TRT Barrel detector, including the quality control procedures used in the fabrication of the detector.
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| 5. |
- Abat, E., et al.
(författare)
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The ATLAS Transition Radiation Tracker (TRT) proportional drift tube: design and performance
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:2
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Tidskriftsartikel (refereegranskat)abstract
- A straw proportional counter is the basic element of the ATLAS Transition Radiation Tracker (TRT). Its detailed properties as well as the main properties of a few TRT operating gas mixtures are described. Particular attention is paid to straw tube performance in high radiation conditions and to its operational stability.
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| 6. |
- Abat, E., et al.
(författare)
-
The ATLAS TRT electronics
- 2008
-
Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:6
-
Tidskriftsartikel (refereegranskat)abstract
- The ATLAS inner detector consists of three sub-systems: the pixel detector spanning the radius range 4cm-20cm, the semiconductor tracker at radii from 30 to 52 cm, and the transition radiation tracker (TRT), tracking from 56 to 107 cm. The TRT provides a combination of continuous tracking with many projective measurements based on individual drift tubes (or straws) and of electron identification based on transition radiation from fibres or foils interleaved between the straws themselves. This paper describes the on and off detector electronics for the TRT as well as the TRT portion of the data acquisition (DAQ) system.
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| 7. |
- Elsik, Christine G., et al.
(författare)
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The Genome Sequence of Taurine Cattle : A Window to Ruminant Biology and Evolution
- 2009
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 324:5926, s. 522-528
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Tidskriftsartikel (refereegranskat)abstract
- To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.
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| 8. |
- Birney, Ewan, et al.
(författare)
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Identification and analysis of functional elements in 1% of the human genome by the ENCODE pilot project
- 2007
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 447:7146, s. 799-816
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Tidskriftsartikel (refereegranskat)abstract
- We report the generation and analysis of functional data from multiple, diverse experiments performed on a targeted 1% of the human genome as part of the pilot phase of the ENCODE Project. These data have been further integrated and augmented by a number of evolutionary and computational analyses. Together, our results advance the collective knowledge about human genome function in several major areas. First, our studies provide convincing evidence that the genome is pervasively transcribed, such that the majority of its bases can be found in primary transcripts, including non-protein-coding transcripts, and those that extensively overlap one another. Second, systematic examination of transcriptional regulation has yielded new understanding about transcription start sites, including their relationship to specific regulatory sequences and features of chromatin accessibility and histone modification. Third, a more sophisticated view of chromatin structure has emerged, including its inter-relationship with DNA replication and transcriptional regulation. Finally, integration of these new sources of information, in particular with respect to mammalian evolution based on inter- and intra-species sequence comparisons, has yielded new mechanistic and evolutionary insights concerning the functional landscape of the human genome. Together, these studies are defining a path for pursuit of a more comprehensive characterization of human genome function.
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| 9. |
- Monks, P. S., et al.
(författare)
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Atmospheric composition change : global and regional air quality
- 2009
-
Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 43:33, s. 5268-5350
-
Forskningsöversikt (refereegranskat)abstract
- Air quality transcends all scales with in the atmosphere from the local to the global with handovers and feedbacks at each scale interaction. Air quality has manifold effects on health, ecosystems heritage and, climate. In this review the state of scientific understanding in relation to global and regional air quality is outlined. The review discusses air quality, in terms of emissions, processing and transport of trace gases and aerosols. New insights into the characterization of both natural and anthropogenic emissions are reviewed looking at both natural (e.g. dust and lightning) as well as plant emissions. Trends in anthropogenic emissions both by region and globally are discussed as well as biomass burning emissions. In terms of chemical processing the major air quality elements of ozone, non-methane hydrocarbons, nitrogen oxides and aerosols are covered. A number of topics are presented as a way of integrating the process view into the atmospheric context; these include the atmospheric oxidation efficiency, halogen and HOx chemistry, nighttime chemistry, tropical chemistry, heat waves, megacities, biomass burning and the regional hot spot of the Mediterranean. New findings with respect to the transport of pollutants across the scales are discussed, in particular the move to quantify the impact of long-range transport on regional air quality. Gaps and research questions that remain intractable are identified. The review concludes with a focus of research and policy questions for the coming decade. In particular, the policy challenges for concerted air quality and climate change policy (co-benefit) are discussed.
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| 10. |
- Laj, P., et al.
(författare)
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Measuring Atmospheric Composition Change
- 2009
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1873-2844 .- 1352-2310. ; 43:33, s. 5351-5414
-
Tidskriftsartikel (refereegranskat)abstract
- Scientific findings from the last decades have clearly highlighted the need for a more comprehensive approach to atmospheric change processes. In fact, observation of atmospheric composition variables has been an important activity of atmospheric research that has developed instrumental tools (advanced analytical techniques) and platforms (instrumented passenger aircrafts, ground-based in-situ and remote sensing stations, earth observation satellite instruments) providing essential information on the composition of the atmosphere. The variability of the atmospheric system and the extreme complexity of the atmospheric cycles for short-lived gaseous and aerosol species have led to the development of complex models to interpret observations, test our theoretical understanding of atmospheric chemistry and predict future atmospheric composition. The validation of numerical models requires accurate information concerning the variability of atmospheric composition for targeted species via comparison with observations and measurements. In this paper, we provide an overview of recent advances in instrumentation and methodologies for measuring atmospheric composition changes from space, aircraft and the surface as well as recent improvements in laboratory techniques that permitted scientific advance in the field of atmospheric chemistry. Emphasis is given to the most promising and innovative technologies that will become operational in the near future to improve knowledge of atmospheric composition. Our current observation capacity, however, is not satisfactory to understand and predict future atmospheric composition changes, in relation to predicted climate warming. Based on the limitation of the current European observing system, we address the major gaps in a second part of the paper to explain why further developments in current observation strategies are still needed to strengthen and optimise an observing system not only capable of responding to the requirements of atmospheric services but also to newly open scientific questions.
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| 11. |
- Geser, F, et al.
(författare)
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The European Multiple System Atrophy-Study Group (EMSA-SG)
- 2005
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Ingår i: Journal of Neural Transmission. - : Springer Science and Business Media LLC. - 0300-9564 .- 1435-1463. ; 112:12, s. 1677-1686
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction. The European Multiple System Atrophy-Study Group (EMSA-SG) is an academic network comprising 23 centers across Europe and Israel that has constituted itself already in January 1999. This international forum of established experts under the guidance of the University Hospital of Innsbruck as coordinating center is supported by the 5th framework program of the European Union since March 2001 (QLK6-CT-2000-00661). Objectives. Primary goals of the network include (1) a central Registry for European multiple system atrophy (MSA) patients, (2) a decentralized DNA Bank, (3) the development and validation of the novel Unified MSA Rating Scale (UMSARS), (4) the conduction of a Natural History Study (NHS), and (5) the planning or implementation of interventional therapeutic trials. Methods. The EMSA-SG Registry is a computerized data bank localized at the coordinating centre in Innsbruck collecting diagnostic and therapeutic data of MSA patients. Blood samples of patients and controls are recruited into the DNA Bank. The UMSARS is a novel specific rating instrument that has been developed and validated by the EMSA-SG. The NHS comprises assessments of basic anthropometric data as well as a range of scales including the UMSARS, Unified Parkinson's Disease Rating Scale (UPDRS), measures of global disability, Red Flag list, MMSE (Mini Mental State Examination), quality of live measures, i.e. EuroQoL 5D (EQ-5D) and Medical Outcome Study Short Form (SF-36) as well as the Beck Depression Inventory (BDI). In a subgroup of patients dysautonomic features are recorded in detail using the Queen Square Cardiovascular Autonomic Function Test Battery, the Composite Autonomic Symptom Scale (COMPASS) and measurements of residual urinary volume. Most of these measures are repeated at 6-monthly follow up visits for a total study period of 24 months. Surrogate markers of the disease progression are identified by the EMSA-SG using magnetic resonance and diffusion weighted imaging (MRI and DWI, respectively). Results. 412 patients have been recruited into the Registry so far. Probable MSA-P was the most common diagnosis (49% of cases). 507 patients donated DNA for research. 131 patients have been recruited into the NHS. There was a rapid deterioration of the motor disorder (in particular akinesia) by 26.1% of the UMSARS II, and - to a lesser degree - of activities of daily living by 16.8% of the UMSARS I in relation to the respective baseline scores. Motor progression was associated with low motor or global disability as well as low akinesia or cerebellar subscores at baseline. Mental function did not deteriorate during this short follow up period. Conclusion. For the first time, prospective data concerning disease progression are available. Such data about the natural history and prognosis of MSA as well as surrogate markers of disease process allow planning and implementation of multi-centre phase II/III neuroprotective intervention trials within the next years more effectively. Indeed, a trial on growth hormone in MSA has just been completed, and another on minocycline will be completed by the end of this year.
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| 12. |
- Sodergren, Erica, et al.
(författare)
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The genome of the sea urchin Strongylocentrotus purpuratus.
- 2006
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 314:5801, s. 941-52
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Tidskriftsartikel (refereegranskat)abstract
- We report the sequence and analysis of the 814-megabase genome of the sea urchin Strongylocentrotus purpuratus, a model for developmental and systems biology. The sequencing strategy combined whole-genome shotgun and bacterial artificial chromosome (BAC) sequences. This use of BAC clones, aided by a pooling strategy, overcame difficulties associated with high heterozygosity of the genome. The genome encodes about 23,300 genes, including many previously thought to be vertebrate innovations or known only outside the deuterostomes. This echinoderm genome provides an evolutionary outgroup for the chordates and yields insights into the evolution of deuterostomes.
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| 13. |
- Cabell, Cristopher H, et al.
(författare)
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Use of surgery in patients with native valve infective endocarditis: results from the International Collaboration on Endocarditis Merged Database.
- 2005
-
Ingår i: American heart journal. - : Elsevier BV. - 1097-6744 .- 0002-8703. ; 150:5, s. 1092-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Early surgery has been shown to be beneficial for patients with infective endocarditis (IE), yet surgery is not used in most patients. Evidence of the uncertainty around the use of surgery can be found in the wide variations in the use of cardiac surgery in IE with few precise indications for cardiac surgery yet defined. The aim of the study was to characterize patients with native valve IE relative to surgery and to determine if patients who benefit from an early surgical intervention can be identified. METHODS: The International Collaboration on Endocarditis Merged Database was used to quantify the differences between patients with IE receiving medical and surgical intervention in 1516 patients with definite native valve IE. Propensity models were built to identify a group of patients that benefit from early surgery. RESULTS: Patients in the early surgical group were more likely to be male, younger, and with less comorbidities compared with the early medical group (P < .001 for all) and were less likely to have infection with Staphylococcus aureus or viridans group streptococci (P < .05 for all). Intracardiac abscess and heart failure were much more common in the surgical group (P < .001 for all). In an unadjusted comparison, there was no statistically significant survival advantage in the surgical group. However, in the propensity analysis, in the subgroup of patients with the most indications for surgery, there was a significant decrease in mortality associated with early surgery (11.2% vs 38.0%, P < .001). CONCLUSIONS: The benefits of surgery are not seen uniformly in all patients with native valve IE, but are most realized in a targeted population. This observation requires confirmation in other populations of patients with definite IE.
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| 14. |
- Fowler, D., et al.
(författare)
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Atmospheric composition change : Ecosystems-Atmosphere interactions
- 2009
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 43:33, s. 5193-5267
-
Forskningsöversikt (refereegranskat)abstract
- Ecosystems and the atmosphere: This review describes the state of understanding the processes involved in the exchange of trace gases and aerosols between the earth's surface and the atmosphere. The gases covered include NO, NO2, HONO, HNO3, NH3, SO2, DMS, Biogenic VOC, O-3, CH4, N2O and particles in the size range 1 nm-10 mu m including organic and inorganic chemical species. The main focus of the review is on the exchange between terrestrial ecosystems, both managed and natural and the atmosphere, although some new developments in ocean-atmosphere exchange are included. The material presented is biased towards the last decade, but includes earlier work, where more recent developments are limited or absent. New methodologies and instrumentation have enabled, if not driven technical advances in measurement. These developments have advanced the process understanding and upscaling of fluxes, especially for particles, VOC and NH3. Examples of these applications include mass spectrometric methods, such as Aerosol Mass Spectrometry (AMS) adapted for field measurement of atmosphere-surface fluxes using micrometeorological methods for chemically resolved aerosols. Also briefly described are some advances in theory and techniques in micrometeorology. For some of the compounds there have been paradigm shifts in approach and application of both techniques and assessment. These include flux measurements over marine surfaces and urban areas using micrometeorological methods and the up-scaling of flux measurements using aircraft and satellite remote sensing. The application of a flux-based approach in assessment of O-3 effects on vegetation at regional scales is an important policy linked development secured through improved quantification of fluxes. The coupling of monitoring, modelling and intensive flux measurement at a continental scale within the NitroEurope network represents a quantum development in the application of research teams to address the underpinning science of reactive nitrogen in the cycling between ecosystems and the atmosphere in Europe. Some important developments of the science have been applied to assist in addressing policy questions, which have been the main driver of the research agenda, while other developments in understanding have not been applied to their wider field especially in chemistry-transport models through deficiencies in obtaining appropriate data to enable application or inertia within the modelling community. The paper identifies applications, gaps and research questions that have remained intractable at least since 2000 within the specialized sections of the paper, and where possible these have been focussed on research questions for the coming decade.
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| 15. |
- Richards, Stephen, et al.
(författare)
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The genome of the model beetle and pest Tribolium castaneum.
- 2008
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Ingår i: Nature. - 1476-4687. ; 452:7190, s. 949-55
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Tidskriftsartikel (refereegranskat)abstract
- Tribolium castaneum is a representative of earth’s most numerous eukaryotic order, a powerful model organism for the study of generalized insect development, and also an important pest of stored agricultural products. We describe its genome sequence here. This omnivorous beetle has evolved an ability to interact with a diverse chemical environment as evidenced by large expansions in odorant and gustatory receptors, as well as p450 and other detoxification enzymes. Developmental patterns in Tribolium are more representative of other arthropods than those found in Drosophila, a fact represented in gene content and function. For one, Tribolium has retained more ancestral genes involved in cell-cell communication than Drosophila, and some are expressed in the growth zone crucial for axial elongation in short germ development. Systemic RNAi in T. castaneum appears to use mechanisms distinct from those found in C. elegans, but nevertheless offers similar power for the elucidation of gene function and identification of targets for selective insect control.
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| 16. |
- Chu, V H, et al.
(författare)
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Coagulase-negative staphylococcal prosthetic valve endocarditis--a contemporary update based on the International Collaboration on Endocarditis: prospective cohort study.
- 2009
-
Ingår i: Heart (British Cardiac Society). - : BMJ. - 1468-201X .- 1355-6037. ; 95:7, s. 570-6
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Tidskriftsartikel (refereegranskat)abstract
- To describe the contemporary features of coagulase-negative staphylococcal (CoNS) prosthetic valve endocarditis (PVE).Observational study of prospectively collected data from a multinational cohort of patients with infective endocarditis. Patients with CoNS PVE were compared to patients with Staphylococcus aureus and viridans streptococcal (VGS) PVE.The International Collaboration on Endocarditis-Prospective Cohort Study (ICE-PCS) is a contemporary cohort of patients with infective endocarditis from 61 centres in 28 countries.Adult patients in the ICE-PCS with definite PVE and no history of injecting drug use from June 2000 to August 2005 were included.None.Heart failure, intracardiac abscess, death.CoNS caused 16% (n = 86) of 537 cases of definite non-injecting drug use-associated PVE. Nearly one-half (n = 33/69, 48%) of patients with CoNS PVE presented between 60 days and 365 days of valve implantation. The rate of intracardiac abscess was significantly higher in patients with CoNS PVE (38%) than in patients with either S aureus (23%, p = 0.03) or VGS (20%, p = 0.05) PVE. The rate of abscess was particularly high in early (50%) and intermediate (52%) CoNS PVE. In-hospital mortality was 24% for CoNS PVE, 36% for S aureus PVE (p = 0.09) and 9.1% for VGS PVE (p = 0.08). Meticillin resistance was present in 68% of CoNS strains.Nearly one-half of CoNS PVE cases occur between 60 days and 365 days of prosthetic valve implantation. CoNS PVE is associated with a high rate of meticillin resistance and significant valvular complications.
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| 17. |
- Lalani, T, et al.
(författare)
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Prosthetic valve endocarditis due to coagulase-negative staphylococci: findings from the International Collaboration on Endocarditis Merged Database.
- 2006
-
Ingår i: European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology. - : Springer Science and Business Media LLC. - 0934-9723. ; 25:6, s. 365-8
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Tidskriftsartikel (refereegranskat)abstract
- Infective endocarditis due to coagulase-negative staphylococci is increasingly recognized as a difficult-to-treat disease associated with poor outcome. The aim of this report is to describe the characteristics and outcome of patients with prosthetic valve endocarditis (PVE) due to coagulase-negative staphylococci versus those of patients with PVE due to Staphylococcus aureus and viridans streptococci. Patients were identified through the International Collaboration on Endocarditis Merged Database. A total of 54 cases of coagulase-negative staphylococci PVE, 58 cases of S. aureus PVE, and 63 cases of viridans-streptococci-related PVE were available for analysis. There was no difference between the three groups with respect to the type of valve involved or the rate of embolization. However, heart failure was encountered more frequently with coagulase-negative staphylococci (54%) than with either S. aureus (33%; p=0.03) or viridans streptococci (32%; p=0.02). In addition, valvular abscesses complicated 39% of infections due to coagulase-negative staphylococci compared with 22% of those due to S. aureus (p=0.06) and 6% of those due to viridans streptococci (p<0.001). Mortality was highest in patients with S. aureus and coagulase-negative staphylococcal endocarditis (47 and 36%, respectively; p=0.22) and was considerably lower in patients with viridans streptococcal endocarditis (p=0.002 compared to patients with coagulase-negative staphylococcal endocarditis). The results of this analysis demonstrate the aggressive nature of coagulase-negative staphylococcal PVE and the substantially greater morbidity and mortality associated with this infection compared to PVE caused by other pathogens.
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| 18. |
- Wang, Andrew, et al.
(författare)
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The use and effect of surgical therapy for prosthetic valve infective endocarditis: a propensity analysis of a multicenter, international cohort.
- 2005
-
Ingår i: American heart journal. - : Elsevier BV. - 1097-6744 .- 0002-8703. ; 150:5, s. 1086-91
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Although surgical intervention is often used in the treatment of prosthetic valve infective endocarditis (PVIE), an understanding of its effect on survival has been limited by the biases of observational studies and lack of controlled trials. METHODS: The International Collaboration on Endocarditis Merged Database is a large, multicenter, international registry of patients with definite endocarditis by Duke criteria, including 367 patients with PVIE. Clinical, microbiologic, and echocardiographic variables were analyzed to determine those factors associated with the use of surgery for PVIE. Logistic regression analysis was performed to create a propensity model of predictors of surgery use. Patients who underwent surgery during initial hospitalization were matched by propensity score with patients treated with medical therapy alone. Logistic regression analysis was performed to determine variables independently associated with inhospital mortality in this matched subset. RESULTS: Surgical therapy for PVIE was performed in 148 (42%) of 367 patients. Inhospital mortality was similar for patients treated with surgery compared with those treated with medical therapy alone (25.0% vs 23.4%, P = .729). Surgical therapy was independently associated with patient age, microorganism, intracardiac abscess, and congestive heart failure. After adjustment for these determinants, inhospital mortality was predicted by brain embolization (OR 11.12, 95% CI 4.16-29.73) and Staphylococcus aureus infection (OR 3.67, 95% CI 1.29-9.74), with a trend toward benefit for surgery (OR 0.56, 95% CI 0.23-1.36). CONCLUSIONS: Despite the frequent use of surgery for the treatment of PVIE, this condition continues to be associated with a high inhospital mortality rate in the contemporary era. After adjustment for factors related to surgical intervention, brain embolism and S aureus infection were independently associated with inhospital mortality and a trend toward a survival benefit of surgery was evident.
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| 19. |
- McDonald, J R, et al.
(författare)
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Enterococcal endocarditis: 107 cases from the international collaboration on endocarditis merged database.
- 2005
-
Ingår i: The American journal of medicine. - : Elsevier BV. - 0002-9343. ; 118:7, s. 759-66
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To describe clinical features and outcomes of enterococcal left-sided native valve endocarditis and to compare it to endocarditis caused by other pathogens. SUBJECTS AND METHODS: Patients in the International Collaboration on Endocarditis-Merged Database were included if they had left-sided native valve endocarditis. Demographic characteristics, clinical features, and outcomes were analyzed. Multivariable analysis evaluated enterococcus as a predictor of mortality. RESULTS: Of 1285 patients with left-sided native valve endocarditis, 107 had enterococcal endocarditis. Enterococcal endocarditis was most frequently seen in elderly men, frequently involved the aortic valve, tended to produce heart failure rather than embolic events, and had relatively low short-term mortality. Compared to patients with non-enterococcal endocarditis, patients with enterococcal endocarditis had similar rates of nosocomial acquisition, heart failure, embolization, surgery, and mortality. Compared to patients with streptococcal endocarditis, patients with enterococcal endocarditis were more likely to be nosocomially acquired (9 of 59 [15%] vs 2 of 400 [1%]; P <.0001) and have heart failure (49 of 107 [46%] vs 234 of 666 [35%]; P = 0.03). Compared to patients with S. aureus endocarditis, patients with enterococcal endocarditis were less likely to embolize (28 of 107 [26%] vs 155 of 314 [49%]; P <.0001) and less likely to die (12 of 107 [11%] vs 83 of 313 [27%]; P = 0.001). Multivariable analysis of all patients with left-sided native valve endocarditis showed that enterococcal endocarditis was associated with lower mortality (odds ratio [OR] 0.49; 95% confidence interval [CI] 0.24 to 0.97). CONCLUSIONS: Enterococcal native valve endocarditis has a distinctive clinical picture with a good prognosis.
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| 20. |
- Anderson, D J, et al.
(författare)
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Enterococcal prosthetic valve infective endocarditis: report of 45 episodes from the International Collaboration on Endocarditis-merged database.
- 2005
-
Ingår i: European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology. - : Springer Science and Business Media LLC. - 0934-9723. ; 24:10, s. 665-70
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Tidskriftsartikel (refereegranskat)abstract
- Enterococcal prosthetic valve infective endocarditis (PVE) is an incompletely understood disease. In the present study, patients with enterococcal PVE were compared to patients with enterococcal native valve endocarditis (NVE) and other types of PVE to determine differences in basic clinical characteristics and outcomes using a large multicenter, international database of patients with definite endocarditis. Forty-five of 159 (29%) cases of definite enterococcal endocarditis were PVE. Patients with enterococcal PVE were demographically similar to patients with enterococcal NVE but had more intracardiac abscesses (20% vs. 6%; p=0.009), fewer valve vegetations (51% vs. 79%; p<0.001), and fewer cases of new valvular regurgitation (12% vs. 45%; p=0.01). Patients with either enterococcal PVE or NVE were elderly (median age, 73 vs. 69; p=0.06). Rates of in-hospital mortality, surgical intervention, heart failure, peripheral embolization, and stroke were similar in both groups. Patients with enterococcal PVE were also demographically similar to patients with other types of PVE, but mortality may be lower (14% vs. 26%; p=0.08). Notably, 93% of patients with enterococcal PVE came from European centers, as compared with only 79% of patients with enterococcal NVE (p=0.03). Thus, patients with enterococcal PVE have higher rates of myocardial abscess formation and lower rates of new regurgitation compared to patients with enterococcal NVE, but there are no differences between the groups with regard to surgical or mortality rates. In contrast, though patients with enterococcal PVE and patients with other types of PVE share similar characteristics, mortality is higher in the latter group. Importantly, the prevalence of enterococcal PVE was higher in the European centers in this study.
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| 21. |
- Kourany, Wissam M, et al.
(författare)
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Influence of diabetes mellitus on the clinical manifestations and prognosis of infective endocarditis: a report from the International Collaboration on Endocarditis-Merged Database.
- 2006
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Ingår i: Scandinavian journal of infectious diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 38:8, s. 613-9
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this investigation was to study the influence of diabetes mellitus (DM) on outcomes of infective endocarditis (IE). Outcomes were compared between 150 diabetic and 905 non-diabetic patients with IE from the International Collaboration on Endocarditis Merged Database. Compared to non-diabetic patients, diabetic patients were older (median age 63 vs 57 y, p<0.001), were more often female (42.0% vs 31.9%, p=0.01), more often had comorbidities (41.5% vs 26.7%, p<0.001), and were more likely to be dialysis dependent (12.7% vs 4.0%, p<0.001). S. aureus was isolated more often (30.7% vs 21.7%, p=0.02), and microorganisms from the viridans Streptococcus group less often (16.7% vs 28.2%, p = 0.001) in the diabetic group. There was no difference with respect to the presence of congestive heart failure, embolism, intra-cardiac abscess, new valvular regurgitation, or valvular vegetation. Diabetic patients underwent surgical intervention less frequently (32.0% vs 44.9%, p = 0.003), and had higher overall in-hospital mortality (30.3% vs 18.6%, p = 0.001). On multivariable analysis, DM was an independent predictor of mortality (odds ratio (OR) = 1.71, 95% confidence interval (CI) 1.08-2.70), especially in male patients, as diabetic males had higher mortality than non-diabetic males (OR 2.18, CI 1.08-4.35). DM is an independent predictor of in-hospital mortality among patients hospitalized with IE.
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| 22. |
- Miro, J M, et al.
(författare)
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Staphylococcus aureus native valve infective endocarditis: report of 566 episodes from the International Collaboration on Endocarditis Merged Database.
- 2005
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Ingår i: Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. - : Oxford University Press (OUP). - 1537-6591. ; 41:4, s. 507-14
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Staphylococcus aureus native valve infective endocarditis (SA-NVIE) is not completely understood. The objective of this investigation was to describe the characteristics of a large, international cohort of patients with SA-NVIE. METHODS: The International Collaboration on Endocarditis Merged Database (ICE-MD) is a combination of 7 existing electronic databases from 5 countries that contains data on 2212 cases of definite infective endocarditis (IE). RESULTS: Of patients with native valve IE, 566 patients [corrected] had IE due to S. aureus, and 1074 patients had IE due to pathogens other than S. aureus (non-SA-NVIE). Patients with S. aureus IE were more likely to die (20% vs. 12%; P < .001), to experience an embolic event (61% [corrected] vs. 31%; P < .001), or to have a central nervous system event (21% [corrected] vs. 13%; P < .001) and were less likely to undergo surgery (26% vs. 39%; P < .001) than were patients with non-SA-NVIE. Multivariate analysis of prognostic factors of mortality identified age (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.1-1.7), periannular abscess (OR, 2.4; 95% CI, 1.0 [corrected] -5.6), heart failure (OR, 3.9; 95% CI, 2.3-6.7), and absence of surgical therapy (OR, 2.3; 95% CI, 1.3-4.2) as variables that were independently associated with mortality in patients with SA-NVIE. After adjusting for patient-, pathogen-, and treatment-specific characteristics by multivariate analysis, geographical region was also found to be associated with mortality in patients with SA-NVIE (P < .001). CONCLUSIONS: S. aureus is an important and common cause of IE. The outcome of SA-NVIE is worse than that of non-SA-NVIE. Several clinical parameters are independently associated with mortality for patients with SA-NVIE. The clinical characteristics and outcome of SA-NVIE vary significantly by geographic region, although the reasons for such regional variations in outcomes of SA-NVIE are unknown and are probably multifactorial. A large, prospective, multinational cohort study of patients with IE is now under way to further investigate these observations.
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| 23. |
- Murdoch, David R, et al.
(författare)
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Clinical presentation, etiology, and outcome of infective endocarditis in the 21st century: the International Collaboration on Endocarditis-Prospective Cohort Study.
- 2009
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Ingår i: Archives of internal medicine. - : American Medical Association (AMA). - 1538-3679 .- 0003-9926. ; 169:5, s. 463-73
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: We sought to provide a contemporary picture of the presentation, etiology, and outcome of infective endocarditis (IE) in a large patient cohort from multiple locations worldwide. METHODS: Prospective cohort study of 2781 adults with definite IE who were admitted to 58 hospitals in 25 countries from June 1, 2000, through September 1, 2005. RESULTS: The median age of the cohort was 57.9 (interquartile range, 43.2-71.8) years, and 72.1% had native valve IE. Most patients (77.0%) presented early in the disease (<30 days) with few of the classic clinical hallmarks of IE. Recent health care exposure was found in one-quarter of patients. Staphylococcus aureus was the most common pathogen (31.2%). The mitral (41.1%) and aortic (37.6%) valves were infected most commonly. The following complications were common: stroke (16.9%), embolization other than stroke (22.6%), heart failure (32.3%), and intracardiac abscess (14.4%). Surgical therapy was common (48.2%), and in-hospital mortality remained high (17.7%). Prosthetic valve involvement (odds ratio, 1.47; 95% confidence interval, 1.13-1.90), increasing age (1.30; 1.17-1.46 per 10-year interval), pulmonary edema (1.79; 1.39-2.30), S aureus infection (1.54; 1.14-2.08), coagulase-negative staphylococcal infection (1.50; 1.07-2.10), mitral valve vegetation (1.34; 1.06-1.68), and paravalvular complications (2.25; 1.64-3.09) were associated with an increased risk of in-hospital death, whereas viridans streptococcal infection (0.52; 0.33-0.81) and surgery (0.61; 0.44-0.83) were associated with a decreased risk. CONCLUSIONS: In the early 21st century, IE is more often an acute disease, characterized by a high rate of S aureus infection. Mortality remains relatively high.
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| 24. |
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| 25. |
- Wang, Andrew, et al.
(författare)
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Contemporary clinical profile and outcome of prosthetic valve endocarditis.
- 2007
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Ingår i: JAMA : the journal of the American Medical Association. - : American Medical Association (AMA). - 1538-3598. ; 297:12, s. 1354-61
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: Prosthetic valve endocarditis (PVE) is associated with significant mortality and morbidity. The contemporary clinical profile and outcome of PVE are not well defined. OBJECTIVES: To describe the prevalence, clinical characteristics, and outcome of PVE, with attention to health care-associated infection, and to determine prognostic factors associated with in-hospital mortality. DESIGN, SETTING, AND PARTICIPANTS: Prospective, observational cohort study conducted at 61 medical centers in 28 countries, including 556 patients with definite PVE as defined by Duke University diagnostic criteria who were enrolled in the International Collaboration on Endocarditis-Prospective Cohort Study from June 2000 to August 2005. MAIN OUTCOME MEASURE: In-hospital mortality. RESULTS: Definite PVE was present in 556 (20.1%) of 2670 patients with infective endocarditis. Staphylococcus aureus was the most common causative organism (128 patients [23.0%]), followed by coagulase-negative staphylococci (94 patients [16.9%]). Health care-associated PVE was present in 203 (36.5%) of the overall cohort. Seventy-one percent of health care-associated PVE occurred within the first year of valve implantation, and the majority of cases were diagnosed after the early (60-day) period. Surgery was performed in 272 (48.9%) patients during the index hospitalization. In-hospital death occurred in 127 (22.8%) patients and was predicted by older age, health care-associated infection (62/203 [30.5%]; adjusted odds ratio [OR], 1.62; 95% confidence interval [CI], 1.08-2.44; P = .02), S aureus infection (44/128 [34.4%]; adjusted OR, 1.73; 95% CI, 1.01-2.95; P = .05), and complications of PVE, including heart failure (60/183 [32.8%]; adjusted OR, 2.33; 95% CI, 1.62-3.34; P<.001), stroke (34/101 [33.7%]; adjusted OR, 2.25; 95% CI, 1.25-4.03; P = .007), intracardiac abscess (47/144 [32.6%]; adjusted OR, 1.86; 95% CI, 1.10-3.15; P = .02), and persistent bacteremia (27/49 [55.1%]; adjusted OR, 4.29; 95% CI, 1.99-9.22; P<.001). CONCLUSIONS: Prosthetic valve endocarditis accounts for a high percentage of all cases of infective endocarditis in many regions of the world. Staphylococcus aureus is now the leading cause of PVE. Health care-associated infection significantly influences the clinical characteristics and outcome of PVE. Complications of PVE strongly predict in-hospital mortality, which remains high despite prompt diagnosis and the frequent use of surgical intervention.
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| 26. |
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| 27. |
- Anguera, Ignasi, et al.
(författare)
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Clinical characteristics and outcome of aortic endocarditis with periannular abscess in the International Collaboration on Endocarditis Merged Database.
- 2005
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Ingår i: The American journal of cardiology. - : Elsevier BV. - 0002-9149. ; 96:7, s. 976-81
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Tidskriftsartikel (refereegranskat)abstract
- The aims of this study were to determine the clinical characteristics and outcome of patients who had definite infective endocarditis (IE) complicated by aortic ring abscess formation that was detected with transesophageal echocardiography (TEE) and to determine the prognostic significance of abscess formation in aortic valve IE. Patients who had aortic valve IE were selected from the International Collaboration on Endocarditis Merged Database (ICE-MD) if they underwent TEE. Among 311 patients who had definite aortic valve IE, 67 (22%) had periannular abscesses. They were more likely to have infection in the setting of a prosthetic valve (40% vs 19%, p <0.001) and coagulase-negative staphylococcal IE (18% vs 6%, p < 0.01) and less likely to have streptococcal IE than were patients who did not develop abscess (28% vs 46%, p = 0.01). Systemic embolization, central nervous system events, and heart failure did not differ between those who developed abscess and those who did not, but power was limited. Patients who had abscess were more likely to undergo surgery (84% vs 36%, p <0.001), and their in-hospital mortality rate was higher (19% vs 11%, p = 0.09). Multivariate analysis of prognostic factors of mortality in aortic IE identified age (odds ratio [OR] 1.6, 95% confidence interval [CI]1.2 to 2.1), Staphylococcus aureus (S. aureus) infection (OR 2.4, 95% CI 1.1 to 5.2), and heart failure (OR 2.9, 95% CI 1.4 to 6.1) as variables that were independently associated with increased risk of death. Periannular abscess formation showed a nonsignificant trend toward an increased risk of death (OR 1.9, 95% CI 0.9 to 3.8). Multivariate analysis of prognostic factors of mortality in complicated aortic IE with abscess formation identified S. aureus infection (OR 6.9, 95% CI 1.6 to 29.4) as independently associated with increased risk of death. In conclusion, in the current era of TEE and high use of surgical treatment, periannular abscess formation in aortic valve IE is not an independent risk factor for mortality. S. aureus infection is an independent prognostic factor for mortality in patients who have abscess formation.
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| 28. |
- Baddley, J W, et al.
(författare)
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Candida infective endocarditis.
- 2008
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Ingår i: European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology. - : Springer Science and Business Media LLC. - 0934-9723. ; 27:7, s. 519-29
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Tidskriftsartikel (refereegranskat)abstract
- Candida infective endocarditis (IE) is uncommon but often fatal. Most epidemiologic data are derived from small case series or case reports. This study was conducted to explore the epidemiology, treatment patterns, and outcomes of patients with Candida IE. We compared 33 Candida IE cases to 2,716 patients with non-fungal IE in the International Collaboration on Endocarditis-Prospective Cohort Study (ICE-PCS). Patients were enrolled and the data collected from June 2000 until August 2005. We noted that patients with Candida IE were more likely to have prosthetic valves (p < 0.001), short-term indwelling catheters (p < 0.0001), and have healthcare-associated infections (p < 0.001). The reasons for surgery differed between the two groups: myocardial abscess (46.7% vs. 22.2%, p = 0.026) and persistent positive blood cultures (33.3% vs. 9.9%, p = 0.003) were more common among those with Candida IE. Mortality at discharge was higher in patients with Candida IE (30.3%) when compared to non-fungal cases (17%, p = 0.046). Among Candida patients, mortality was similar in patients who received combination surgical and antifungal therapy versus antifungal therapy alone (33.3% vs. 27.8%, p = 0.26). New antifungal drugs, particularly echinocandins, were used frequently. These multi-center data suggest distinct epidemiologic features of Candida IE when compared to non-fungal cases. Indications for surgical intervention are different and mortality is increased. Newer antifungal treatment options are increasingly used. Large, multi-center studies are needed to help better define Candida IE.
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| 29. |
- Benito, Natividad, et al.
(författare)
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Health care-associated native valve endocarditis: importance of non-nosocomial acquisition.
- 2009
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Ingår i: Annals of internal medicine. - : American College of Physicians. - 1539-3704 .- 0003-4819. ; 150:9, s. 586-94
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Tidskriftsartikel (refereegranskat)abstract
- The clinical profile and outcome of nosocomial and non-nosocomial health care-associated native valve endocarditis are not well defined.To compare the characteristics and outcomes of community-associated and nosocomial and non-nosocomial health care-associated native valve endocarditis.Prospective cohort study.61 hospitals in 28 countries.Patients with definite native valve endocarditis and no history of injection drug use who were enrolled in the ICE-PCS (International Collaboration on Endocarditis Prospective Cohort Study) from June 2000 to August 2005.Clinical and echocardiographic findings, microbiology, complications, and mortality.Health care-associated native valve endocarditis was present in 557 (34%) of 1622 patients (303 with nosocomial infection [54%] and 254 with non-nosocomial infection [46%]). Staphylococcus aureus was the most common cause of health care-associated infection (nosocomial, 47%; non-nosocomial, 42%; P = 0.30); a high proportion of patients had methicillin-resistant S. aureus (nosocomial, 57%; non-nosocomial, 41%; P = 0.014). Fewer patients with health care-associated native valve endocarditis had cardiac surgery (41% vs. 51% of community-associated cases; P < 0.001), but more of the former patients died (25% vs. 13%; P < 0.001). Multivariable analysis confirmed greater mortality associated with health care-associated native valve endocarditis (incidence risk ratio, 1.28 [95% CI, 1.02 to 1.59]).Patients were treated at hospitals with cardiac surgery programs. The results may not be generalizable to patients receiving care in other types of facilities or to those with prosthetic valves or past injection drug use.More than one third of cases of native valve endocarditis in non-injection drug users involve contact with health care, and non-nosocomial infection is common, especially in the United States. Clinicians should recognize that outpatients with extensive out-of-hospital health care contacts who develop endocarditis have clinical characteristics and outcomes similar to those of patients with nosocomial infection.None.
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