4,755 research outputs found
Enhancing drug safety through active surveillance of observational healthcare data
Drug safety continues to be a major public health concern in the United States, with adverse drug reactions ranking as the 4th to 6th leading cause of death, and resulting in health care costs of $3.6 billion annually. Recent media attention and public scrutiny of high-profile drug safety issues have increased visibility and skepticism of the effectiveness of the current post-approval safety surveillance processes. Current proposals suggest establishing a national active drug safety surveillance system that leverages observational data, including administrative claims and electronic health records, to monitor and evaluate potential safety issues of medicines. However, the development and evaluation of appropriate strategies for systematic analysis of observational data have not yet been studied. This study introduces a novel exploratory analysis approach (Comparator-Adjusted Safety Surveillance or COMPASS) to identify drug-related adverse events in automated healthcare data. The aims of the study were: 1) to characterize the performance of COMPASS in identifying known safety issues associated with ACE inhibitor exposure within an administrative claims database; 2) to evaluate consistency of COMPASS estimates across a network of disparate databases; and 3) to explore differential effects across ingredients within ACE inhibitor class. COMPASS was observed to have improved accuracy to three other methods under consideration for an active surveillance system: observational screening, disproportionality analysis, and self-controlled case series. COMPASS performance was consistently strong within 5 different databases, though important differences in outcome estimates across the sources highlighted the substantial heterogeneity which makes pooling estimates challenging. The comparative safety analysis of products within the ACE inhibitor class provided evidence of similar risk profiles across an array of different outcomes, and raised questions about the product labeling differences and how observational studies should complement existing evidence as part of a broader safety assessment strategy. The results of this study should inform decisions about the appropriateness and utility of analyzing observational data as part of an active drug safety surveillance process. An improved surveillance system would enable a more comprehensive and timelier understanding of the safety of medicines. Such information supports patients and providers in therapeutic decision-making to minimize risks and improve the quality of care
Self-referenced continuous-variable quantum key distribution protocol
We introduce a new continuous-variable quantum key distribution (CV-QKD)
protocol, self-referenced CV-QKD, that eliminates the need for transmission of
a high-power local oscillator between the communicating parties. In this
protocol, each signal pulse is accompanied by a reference pulse (or a pair of
twin reference pulses), used to align Alice's and Bob's measurement bases. The
method of phase estimation and compensation based on the reference pulse
measurement can be viewed as a quantum analog of intradyne detection used in
classical coherent communication, which extracts the phase information from the
modulated signal. We present a proof-of-principle, fiber-based experimental
demonstration of the protocol and quantify the expected secret key rates by
expressing them in terms of experimental parameters. Our analysis of the secret
key rate fully takes into account the inherent uncertainty associated with the
quantum nature of the reference pulse(s) and quantifies the limit at which the
theoretical key rate approaches that of the respective conventional protocol
that requires local oscillator transmission. The self-referenced protocol
greatly simplifies the hardware required for CV-QKD, especially for potential
integrated photonics implementations of transmitters and receivers, with
minimum sacrifice of performance. As such, it provides a pathway towards
scalable integrated CV-QKD transceivers, a vital step towards large-scale QKD
networks.Comment: 14 pages, 10 figures. Published versio
Critical function of endogenous XIAP in regulating caspase activation during sympathetic neuronal apoptosis
In sympathetic neurons, unlike most nonneuronal cells, growth factor withdrawal–induced apoptosis requires the development of competence in addition to cytochrome c release to activate caspases. Thus, although most nonneuronal cells die rapidly with cytosolic cytochrome c alone, sympathetic neurons are remarkably resistant unless they develop competence. We have identified endogenous X-linked inhibitor of apoptosis protein (XIAP) as the essential postcytochrome c regulator of caspase activation in these neurons. In contrast to wild-type neurons that are resistant to injection of cytochrome c, XIAP-deficient neurons died rapidly with cytosolic cytochrome c alone. Surprisingly, the release of endogenous Smac was not sufficient to overcome the XIAP resistance in sympathetic neurons. In contrast, the neuronal competence pathway permitted cytochrome c to activate caspases by inducing a marked reduction in XIAP levels in these neurons. Thus, the removal of XIAP inhibition appears both necessary and sufficient for cytochrome c to activate caspases in sympathetic neurons. These data identify a critical function of endogenous XIAP in regulating apoptosis in mammalian cells
HST Grism Observations of a Gravitationally Lensed Redshift 10 Galaxy
We present deep spectroscopic observations of a Lyman-break galaxy candidate
(hereafter MACS1149-JD) at with the Space
Telescope () WFC3/IR grisms. The grism observations were taken at
4 distinct position angles, totaling 34 orbits with the G141 grism, although
only 19 of the orbits are relatively uncontaminated along the trace of
MACS1149-JD. We fit a 3-parameter (, F160W mag, and Ly equivalent
width) Lyman-break galaxy template to the three least contaminated grism
position angles using an MCMC approach. The grism data alone are best fit with
a redshift of ( confidence), in
good agreement with our photometric estimate of
( confidence). Our analysis
rules out Lyman-alpha emission from MACS1149-JD above a equivalent
width of 21 \AA{}, consistent with a highly neutral IGM. We explore a scenario
where the red /IRAC color of the galaxy
previously pointed out in the literature is due to strong rest-frame optical
emission lines from a very young stellar population rather than a 4000 \AA{}
break. We find that while this can provide an explanation for the observed IRAC
color, it requires a lower redshift (), which is less preferred
by the imaging data. The grism data are consistent with both
scenarios, indicating that the red IRAC color can still be explained by a 4000
\AA{} break, characteristic of a relatively evolved stellar population. In this
interpretation, the photometry indicate that a Myr stellar
population is already present in this galaxy only after
the Big Bang.Comment: Accepted to ApJ. This is the accepted versio
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Comparison of First-Line Dual Combination Treatments in Hypertension: Real-World Evidence from Multinational Heterogeneous Cohorts.
Background and objectives: 2018 ESC/ESH Hypertension guideline recommends 2-drug combination as initial anti-hypertensive therapy. However, real-world evidence for effectiveness of recommended regimens remains limited. We aimed to compare the effectiveness of first-line anti-hypertensive treatment combining 2 out of the following classes: angiotensin-converting enzyme (ACE) inhibitors/angiotensin-receptor blocker (A), calcium channel blocker (C), and thiazide-type diuretics (D).Methods: Treatment-naïve hypertensive adults without cardiovascular disease (CVD) who initiated dual anti-hypertensive medications were identified in 5 databases from US and Korea. The patients were matched for each comparison set by large-scale propensity score matching. Primary endpoint was all-cause mortality. Myocardial infarction, heart failure, stroke, and major adverse cardiac and cerebrovascular events as a composite outcome comprised the secondary measure.Results: A total of 987,983 patients met the eligibility criteria. After matching, 222,686, 32,344, and 38,513 patients were allocated to A+C vs. A+D, C+D vs. A+C, and C+D vs. A+D comparison, respectively. There was no significant difference in the mortality during total of 1,806,077 person-years: A+C vs. A+D (hazard ratio [HR], 1.08; 95% confidence interval [CI], 0.97-1.20; p=0.127), C+D vs. A+C (HR, 0.93; 95% CI, 0.87-1.01; p=0.067), and C+D vs. A+D (HR, 1.18; 95% CI, 0.95-1.47; p=0.104). A+C was associated with a slightly higher risk of heart failure (HR, 1.09; 95% CI, 1.01-1.18; p=0.040) and stroke (HR, 1.08; 95% CI, 1.01-1.17; p=0.040) than A+D.Conclusions: There was no significant difference in mortality among A+C, A+D, and C+D combination treatment in patients without previous CVD. This finding was consistent across multi-national heterogeneous cohorts in real-world practice
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Dam Removal I: Synthesis of Common Management Concerns Associated with Dam Removal
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