28 resultados para mode I testing
em BORIS: Bern Open Repository and Information System - Berna - Suiça
Resumo:
Treatment guidelines recommend strong consideration of thrombolysis in patients with acute symptomatic pulmonary embolism (PE) that present with arterial hypotension or shock because of the high risk of death in this setting. For haemodynamically stable patients with PE, the categorization of risk for subgroups may assist with decision-making regarding PE therapy. Clinical models [e.g. Pulmonary Embolism Severity Index (PESI)] may accurately identify those at low risk of overall death in the first 3 months after the diagnosis of PE, and such patients might benefit from an abbreviated hospital stay or outpatient therapy. Though some evidence suggests that a subset of high-risk normotensive patients with PE may have a reasonable risk to benefit ratio for thrombolytic therapy, single markers of right ventricular dysfunction (e.g. echocardiography, spiral computed tomography, or brain natriuretic peptide testing) and myocardial injury (e.g. cardiac troponin T or I testing) have an insufficient positive predictive value for PE-specific mortality to drive decision-making toward such therapy. Recommendations for outpatient treatment or thrombolytic therapy for patients with PE necessitate further development of prognostic models and conduct of clinical trials that assess various treatment strategies.
Resumo:
The OPERA experiment is searching for νμ → ντ oscillations in appearance mode, i.e., via the direct detection of τ leptons in ντ charged-current interactions. The evidence of νμ → ντ appearance has been previously reported with three ντ candidate events using a sub-sample of data from the 2008–2012 runs. We report here a fourth ντ candidate event, with the τ decaying into a hadron, found after adding the 2012 run events without any muon in the final state to the data sample. Given the number of analyzed events and the low background, νμ → ντ oscillations are established with a significance of 4.2σ.
Resumo:
The OPERA experiment is designed to search for ν μ →ν τ oscillations in appearance mode, i.e., through the direct observation of the τ lepton in ν τ -charged current interactions. The experiment has taken data for five years, since 2008, with the CERN Neutrino to Gran Sasso beam. Previously, two ν τ candidates with a τ decaying into hadrons were observed in a subsample of data of the 2008–2011 runs. Here we report the observation of a third ν τ candidate in the τ − →μ − decay channel coming from the analysis of a subsample of the 2012 run. Taking into account the estimated background, the absence of ν μ →ν τ oscillations is excluded at the 3.4 σ level.
Resumo:
The OPERA experiment was designed to search for νµ → ντ oscillations in appearance mode, i.e. by detecting the τ leptons produced in charged current ντ interactions. The experiment took data from 2008 to 2012 in the CERN Neutrinos to Gran Sasso beam. The observation of the νµ → ντ appearance, achieved with four candidate events in a subsample of the data, was previously reported. In this Letter, a fifth ντ candidate event, found in an enlarged data sample, is described. Together with a further reduction of the expected background, the candidate events detected so far allow us to assess the discovery of νµ → ντ oscillations in appearance mode with a significance larger than 5 σ.
Resumo:
The Default Mode Network (DMN) is a higher order functional neural network that displays activation during passive rest and deactivation during many types of cognitive tasks. Accordingly, the DMN is viewed to represent the neural correlate of internally-generated self-referential cognition. This hypothesis implies that the DMN requires the involvement of cognitive processes, like declarative memory. The present study thus examines the spatial and functional convergence of the DMN and the semantic memory system. Using an active block-design functional Magnetic Resonance Imaging (fMRI) paradigm and Independent Component Analysis (ICA), we trace the DMN and fMRI signal changes evoked by semantic, phonological and perceptual decision tasks upon visually-presented words. Our findings show less deactivation during semantic compared to the two non-semantic tasks for the entire DMN unit and within left-hemispheric DMN regions, i.e., the dorsal medial prefrontal cortex, the anterior cingulate cortex, the retrosplenial cortex, the angular gyrus, the middle temporal gyrus and the anterior temporal region, as well as the right cerebellum. These results demonstrate that well-known semantic regions are spatially and functionally involved in the DMN. The present study further supports the hypothesis of the DMN as an internal mentation system that involves declarative memory functions.
Resumo:
A low simplified Pulmonary Embolism Severity Index (sPESI), defined as age ≤80 years and absence of systemic hypotension, tachycardia, hypoxia, cancer, heart failure, and lung disease, identifies low-risk patients with acute pulmonary embolism (PE). It is unknown whether cardiac troponin testing improves the prediction of clinical outcomes if the sPESI is not low. In the prospective Swiss Venous Thromboembolism Registry, 369 patients with acute PE and a troponin test (conventional troponin T or I, highly sensitive troponin T) were enrolled from 18 hospitals. A positive test result was defined as a troponin level above the manufacturers assay threshold. Among the 106 (29%) patients with low sPESI, the rate of mortality or PE recurrence at 30 days was 1.0%. Among the 263 (71%) patients with high sPESI, 177 (67%) were troponin-negative and 86 (33%) troponin-positive; the rate of mortality or PE recurrence at 30 days was 4.6% vs. 12.8% (p=0.015), respectively. Overall, risk assessment with a troponin test (hazard ratio [HR] 3.39, 95% confidence interval [CI] 1.38-8.37; p=0.008) maintained its prognostic value for mortality or PE recurrence when adjusted for sPESI (HR 5.80, 95%CI 0.76-44.10; p=0.09). The combination of sPESI with a troponin test resulted in a greater area under the receiver-operating characteristic curve (HR 0.72, 95% CI 0.63-0.81) than sPESI alone (HR 0.63, 95% CI 0.57-0.68) (p=0.023). In conclusion, although cardiac troponin testing may not be required in patients with a low sPESI, it adds prognostic value for early death and recurrence for patients with a high sPESI.
Resumo:
The primary aim was to investigate the effect of combined butafosfan and cyanocobalamin on liver metabolism in early lactating cows through mRNA expression measurements of genes encoding 31 enzymes and transport proteins of major metabolic processes in the liver using 16 multiparous early lactating dairy cows. The treatments included i.v. injection of 10 mL/100 kg of body weight combined butafosfan and cyanocobalamin (TG, n = 8) on 3 d consecutively at 25 +/- 3 d in milk or injection with physiological saline solution similarly applied (CG, n = 8). Results include a higher daily milk production for TG cows (41.1 +/- 0.9 kg, mean +/- SEM) compared with CG cows (39.5 +/- 0.7 kg). In plasma, the concentration of inorganic phosphorus was lower in the TG cows (1.25 +/- 0.08 mmol/L) after the treatment than in the CG cows (1.33 +/- 0.07 mmol/L). The plasma beta-hydroxybutyrate concentration was 0.65 +/- 0.13 mmol/L for all cows before the treatment, and remained unaffected post treatment. The unique result was that in the liver, the mRNA abundance of acyl-coenzyme A synthetase long-chain family member 1, involved in fatty acid oxidation and biosynthesis, was lower across time points after the treatment for TG compared with CG cows (17.5 +/- 0.15 versus 18.1 +/- 0.24 cycle threshold, log(2), respectively). In conclusion, certain effects of combined butafosfan and cyanocobalamin were observed on mRNA abundance of a gene in the liver of nonketotic early lactating cows.
Resumo:
Biomarkers are currently best used as mechanistic "signposts" rather than as "traffic lights" in the environmental risk assessment of endocrine-disrupting chemicals (EDCs). In field studies, biomarkers of exposure [e.g., vitellogenin (VTG) induction in male fish] are powerful tools for tracking single substances and mixtures of concern. Biomarkers also provide linkage between field and laboratory data, thereby playing an important role in directing the need for and design of fish chronic tests for EDCs. It is the adverse effect end points (e.g., altered development, growth, and/or reproduction) from such tests that are most valuable for calculating adverseNOEC (no observed effect concentration) or adverseEC10 (effective concentration for a 10% response) and subsequently deriving predicted no effect concentrations (PNECs). With current uncertainties, biomarkerNOEC or biomarkerEC10 data should not be used in isolation to derive PNECs. In the future, however, there may be scope to increasingly use biomarker data in environmental decision making, if plausible linkages can be made across levels of organization such that adverse outcomes might be envisaged relative to biomarker responses. For biomarkers to fulfil their potential, they should be mechanistically relevant and reproducible (as measured by interlaboratory comparisons of the same protocol). VTG is a good example of such a biomarker in that it provides an insight to the mode of action (estrogenicity) that is vital to fish reproductive health. Interlaboratory reproducibility data for VTG are also encouraging; recent comparisons (using the same immunoassay protocol) have provided coefficients of variation (CVs) of 38-55% (comparable to published CVs of 19-58% for fish survival and growth end points used in regulatory test guidelines). While concern over environmental xenoestrogens has led to the evaluation of reproductive biomarkers in fish, it must be remembered that many substances act via diverse mechanisms of action such that the environmental risk assessment for EDCs is a broad and complex issue. Also, biomarkers such as secondary sexual characteristics, gonadosomatic indices, plasma steroids, and gonadal histology have significant potential for guiding interspecies assessments of EDCs and designing fish chronic tests. To strengthen the utility of EDC biomarkers in fish, we need to establish a historical control database (also considering natural variability) to help differentiate between statistically detectable versus biologically significant responses. In conclusion, as research continues to develop a range of useful EDC biomarkers, environmental decision-making needs to move forward, and it is proposed that the "biomarkers as signposts" approach is a pragmatic way forward in the current risk assessment of EDCs.
Resumo:
Fillers are an important tool in the armamentarium of the physician combating aging phenomena. A wide variety of filler substances are now available that meet many, but by far not all, needs in aesthetic medicine. The most commonly used substances now are hyaluronic acid and collagen preparations that have slightly different indications, but collagen requires pre-use testing to rule out inflammatory complications. Poly-L-lactic acid has gained its place in the filling of adipose tissue wasting in HIV-infected patients. Autologous fat is easy to harvest and inject and has virtually no risk of adverse side effects. Permanent fillers may be of advantage but carry the risk of permanent adverse reactions. Skillful combination of different fillers as well as with botulinum toxin injections and other cosmetic procedures may give optimal results.
Resumo:
OBJECTIVE: This study aimed to assess the potential cost-effectiveness of testing patients with nephropathies for the I/D polymorphism before starting angiotensin-converting enzyme (ACE) inhibitor therapy, using a 3-year time horizon and a healthcare perspective. METHODS: We used a combination of a decision analysis and Markov modeling technique to evaluate the potential economic value of this pharmacogenetic test by preventing unfavorable treatment in patients with nephropathies. The estimation of the predictive value of the I/D polymorphism is based on a systematic review showing that DD carriers tend to respond well to ACE inhibitors, while II carriers seem not to benefit adequately from this treatment. Data on the ACE inhibitor effectiveness in nephropathy were derived from the REIN (Ramipril Efficacy in Nephropathy) trial. We calculated the number of patients with end-stage renal disease (ESRD) prevented and the differences in the incremental costs and incremental effect expressed as life-years free of ESRD. A probabilistic sensitivity analysis was conducted to determine the robustness of the results. RESULTS: Compared with unselective treatment, testing patients for their ACE genotype could save 12 patients per 1000 from developing ESRD during the 3 years covered by the model. As the mean net cost savings was euro 356,000 per 1000 patient-years, and 9 life-years free of ESRD were gained, selective treatment seems to be dominant. CONCLUSION: The study suggests that genetic testing of the I/D polymorphism in patients with nephropathy before initiating ACE therapy will most likely be cost-effective, even if the risk for II carriers to develop ESRD when treated with ACE inhibitors is only 1.4% higher than for DD carriers. Further studies, however, are required to corroborate the difference in treatment response between ACE genotypes, before genetic testing can be justified in clinical practice.
Resumo:
Arabidopsis thaliana has emerged as a leading model species in plant genetics and functional genomics including research on the genetic causes of heterosis. We applied a triple testcross (TTC) design and a novel biometrical approach to identify and characterize quantitative trait loci (QTL) for heterosis of five biomass-related traits by (i) estimating the number, genomic positions, and genetic effects of heterotic QTL, (ii) characterizing their mode of gene action, and (iii) testing for presence of epistatic effects by a genomewide scan and marker x marker interactions. In total, 234 recombinant inbred lines (RILs) of Arabidopsis hybrid C24 x Col-0 were crossed to both parental lines and their F1 and analyzed with 110 single-nucleotide polymorphism (SNP) markers. QTL analyses were conducted using linear transformations Z1, Z2, and Z3 calculated from the adjusted entry means of TTC progenies. With Z1, we detected 12 QTL displaying augmented additive effects. With Z2, we mapped six QTL for augmented dominance effects. A one-dimensional genome scan with Z3 revealed two genomic regions with significantly negative dominance x additive epistatic effects. Two-way analyses of variance between marker pairs revealed nine digenic epistatic interactions: six reflecting dominance x dominance effects with variable sign and three reflecting additive x additive effects with positive sign. We conclude that heterosis for biomass-related traits in Arabidopsis has a polygenic basis with overdominance and/or epistasis being presumably the main types of gene action.
Variability of anti-PF4/heparin antibody results obtained by the rapid testing system ID-H/PF4-PaGIA
Resumo:
BACKGROUND: Recent studies have shown that a low clinical pretest probability may be adequate for excluding heparin-induced thrombocytopenia. However, for patients with intermediate or high pretest probability, laboratory testing is essential for confirming or refuting the diagnosis. Rapid assessment of anti-PF4/heparin-antibodies may assist clinical decision-making. OBJECTIVES: To evaluate the performance of rapid ID-H/PF4-PaGIA. In particular, we verified reproducibility of results between plasma and serum specimens, between fresh and frozen samples, and between different ID-H/PF4-polymer lots (polystyrene beads coated with heparin/PF4-complexes). PATIENTS/METHODS: The samples studied were 1376 plasma and 914 corresponding serum samples from patients investigated for suspected heparin-induced thrombocytopenia between January 2000 and October 2008. Anti-PF4/heparin-antibodies were assessed by ID-H/PF4-PaGIA, commercially available ELISAs and heparin-induced platelet aggregation test. RESULTS: Among 914 paired plasma/serum samples we noted discordant results (negative vs. low-titre positive) in nine instances (1%; 95%CI, 0.4-1.6%). Overall, agreement between titres assessed in plasma vs. serum was highly significant (Spearman correlation coefficient, 0.975; P < 0.0001). Forty-seven samples tested both fresh and after freezing/thawing showed a good agreement, with one discordant positive/negative result (Spearman correlation coefficient, 0.970; P < 0.0001). Among 1376 plasma samples we noted a strikingly variable incidence of false negative results (none - 82%; 95%CI, 66-98%), depending on the employed ID-H/PF4-polymer lot. Faulty lots can be recognized by titrating commercial positive controls and stored samples of HIT-patients. CONCLUSION: Laboratories performing the assay should implement stringent internal quality controls in order to recognize potentially faulty ID-H/PF4-polymer lots, thus avoiding false negative results.
Resumo:
The use of glasses doped with PbS nanocrystals as intracavity saturable absorbers for passive Q-switching and mode locking of c-cut Nd:Gd0.7Y0.3VO4, Nd:YVO4, and Nd:GdVO4 lasers is investigated. Q-switching yields pulses as short as 35 ns with an average output power of 435 mW at a repetition rate of 6–12 kHz at a pump power of 5–6 W. Mode locking through a combination of PbS nanocrystals and a Kerr lens results in 1.4 ps long pulses with an average output power of 255 mW at a repetition rate of 100 MHz.