84 research outputs found
What are effective therapies for Clostridium difficile- associated diarrhea?
Oral metronidazole and oral vancomycin are
equally effective treatments for Clostridium difficile- associated diarrhea (CDAD) (strength of recommendation [SOR]: A, based on randomized trials). Oral vancomycin is considerably more expensive and may select for colonization with vancomycin-resistant enterococci, leading the American College of Gastroenterology to recommend oral metronidazole as preferred therapy (SOR: C, expert opinion). They recommend therapy with vancomycin for those who are pregnant, breast feeding, less than 10years old, nonresponders to metronidazole, critically ill, or allergic or intolerant to metronidazole (SOR: C, expert opinion)
Frequency of human immunodeficiency virus (HIV) testing in urban vs. rural areas of the United States: Results from a nationally-representative sample
<p>Abstract</p> <p>Background</p> <p>Studies in the United States show that rural persons with HIV are more likely than their urban counterparts to be diagnosed at a late stage of infection, suggesting missed opportunities for HIV testing in rural areas. To inform discussion of HIV testing policies in rural areas, we generated nationally representative, population-based estimates of HIV testing frequencies in urban vs. rural areas of the United States.</p> <p>Methods</p> <p>Secondary analysis of 2005 and 2009 Behavioral Risk Factor Surveillance System (BRFSS) data. Dependent variables were self-reported lifetime and past-year HIV testing. Urban vs. rural residence was determined using the metropolitan area framework and Urban Influence Codes and was categorized as 1) metropolitan, center city (the most urban); 2) metropolitan, other; 3) non-metropolitan, adjacent to metropolitan; 4) non-metropolitan, micropolitan; and 4) remote, non-metropolitan (the most rural).</p> <p>Results</p> <p>The 2005 sample included 257,895 respondents. Lifetime HIV testing frequencies ranged from 43.6% among persons residing in the most urban areas to 32.2% among persons in the most rural areas (P < 0.001). Past-year testing frequencies ranged from 13.5% to 7.3% in these groups (P < 0.001). After adjusting for demographics (age, sex, race/ethnicity, and region of residence) and self-reported HIV risk factors, persons in the most remote rural areas were substantially less likely than persons in the most urban areas to report HIV testing in the past year (odds ratio 0.65, 95% CI 0.57-0.75). Testing rates in urban and rural areas did not change substantively following the 2006 Centers for Disease Control and Prevention recommendation for routine, population-based HIV testing in healthcare settings. In metropolitan (urban) areas, 11.5% (95% CI 11.2-11.8) reported past-year HIV testing in 2005 vs. 11.4% (95% CI 11.1%-11.7%) in 2009 (P = 0.93). In non-metropolitan areas, 8.7% (95% CI 8.2%-9.2%) were tested in 2005 vs. 7.7% (95% CI 7.2%-8.2%) in 2009 (P = 0.03).</p> <p>Conclusions</p> <p>Rural persons are less likely than urban to report prior HIV testing, which may contribute to later HIV diagnosis in rural areas. There is need to consider strategies to increase HIV testing in rural areas.</p
Flavor Symmetries and The Problem of Squark Degeneracy
If supersymmetry exists at low energies, it is necessary to understand why
the squark spectrum exhibits sufficient degeneracy to suppress flavor changing
neutral currents. In this note, we point out that gauged horizontal symmetries
can yield realistic quark mass matrices, while at the same time giving just
barely enough squark degeneracy to account for neutral -meson phenomenology.
This approach suggests likely patterns for squark masses, and indicates that
there could be significant supersymmetric contributions to and
mixing and CP violation in the and systems.Comment: preprint SCIPP 93/04,SLAC-PUB-6147, 14 pages, 4 tables included; uses
macro package TABLES.TEX and phyzzx forma
Invisible Z-Boson Decays at e+e- Colliders
The measurement of the invisible Z-boson decay width at e+e- colliders can be
done "indirectly", by subtracting the Z-boson visible partial widths from the
Z-boson total width, or "directly", from the process e+e- -> \gamma \nu
\bar{\nu}. Both procedures are sensitive to different types of new physics and
provide information about the couplings of the neutrinos to the Z-boson. At
present, measurements at LEP and CHARM II are capable of constraining the
left-handed Z\nu\nu-coupling, 0.45 <~ g_L <~ 0.5, while the right-handed one is
only mildly bounded, |g_R| <= 0.2. We show that measurements at a future e+e-
linear collider at different center-of-mass energies, \sqrt{s} = MZ and
\sqrt{s}s ~ 170 GeV, would translate into a markedly more precise measurement
of the Z\nu\nu-couplings. A statistically significant deviation from Standard
Model predictions will point toward different new physics mechanisms, depending
on whether the discrepancy appears in the direct or the indirect measurement of
the invisible Z-width. We discuss some scenarios which illustrate the ability
of different invisible Z-boson decay measurements to constrain new physics
beyond the Standard Model
Impact of Age on Retention in Care and Viral Suppression
Retention in care is important for all HIV-infected persons and is strongly associated with initiation of antiretroviral therapy and viral suppression. However, it is unclear how retention in care and age interact to effect viral suppression. We evaluated whether the association between retention and viral suppression differed by age at entry into care
Normalization of Voltage-Sensitive Dye Signal with Functional Activity Measures
In general, signal amplitude in optical imaging is normalized using the
well-established ΔF/F method, where functional activity is divided by
the total fluorescent light flux. This measure is used both directly, as a
measure of population activity, and indirectly, to quantify spatial and
spatiotemporal activity patterns. Despite its ubiquitous use, the stability and
accuracy of this measure has not been validated for voltage-sensitive dye
imaging of mammalian neocortex in vivo. In this report, we find
that this normalization can introduce dynamic biases. In particular, the
ΔF/F is influenced by dye staining quality, and the ratio is also
unstable over the course of experiments. As methods to record and analyze
optical imaging signals become more precise, such biases can have an
increasingly pernicious impact on the accuracy of findings, especially in the
comparison of cytoarchitechtonic areas, in area-of-activation measurements, and
in plasticity or developmental experiments. These dynamic biases of the
ΔF/F method may, to an extent, be mitigated by a novel method of
normalization, ΔF/ΔFepileptiform. This normalization
uses as a reference the measured activity of epileptiform spikes elicited by
global disinhibition with bicuculline methiodide. Since this normalization is
based on a functional measure, i.e. the signal amplitude of
“hypersynchronized” bursts of activity in the cortical
network, it is less influenced by staining of non-functional elements. We
demonstrate that such a functional measure can better represent the amplitude of
population mass action, and discuss alternative functional normalizations based
on the amplitude of synchronized spontaneous sleep-like activity. These findings
demonstrate that the traditional ΔF/F normalization of voltage-sensitive
dye signals can introduce pernicious inaccuracies in the quantification of
neural population activity. They further suggest that normalization-independent
metrics such as waveform propagation patterns, oscillations in single detectors,
and phase relationships between detector pairs may better capture the biological
information which is obtained by high-sensitivity imaging
Dexamethasone in hospitalised coronavirus-19 patients not on intensive respiratory support.
INTRODUCTION: Dexamethasone decreases mortality in coronavirus disease 2019 (COVID-19) patients on intensive respiratory support (IRS) but is of uncertain benefit if less severely ill. We determined whether early (within 48 h) dexamethasone was associated with mortality in patients hospitalised with COVID-19 not on IRS. METHODS: We included patients admitted to Veterans Affairs hospitals between June 7, 2020-May 31, 2021 within 14-days after SARS-CoV-2 positive test. Exclusions included recent prior corticosteroids and IRS within 48 h. We used inverse probability of treatment weights (IPTW) to balance exposed and unexposed groups, and Cox proportional hazards models to determine 90-day all-cause mortality. RESULTS: Of 19 973 total patients (95% men, median age 71, 27% black), 15 404 (77%) were without IRS within 48 h. Of these, 3514/9450 (34%) patients on no oxygen received dexamethasone and 1042 (11%) died; 4472/5954 (75%) patients on low-flow nasal cannula (NC) received dexamethasone and 857 (14%) died. In IPTW stratified models, patients on no oxygen who received dexamethasone experienced 76% increased risk for 90-day mortality (hazard ratio [HR] 1.76, 95% confidence interval [CI] 1.47 to 2.12); there was no association with mortality among patients on NC (HR 1.08, 95% CI 0.86 to 1.36). CONCLUSION: In patients hospitalised with COVID-19, early initiation of dexamethasone was common and was associated with no mortality benefit among those on no oxygen or NC in the first 48 h; instead, we found evidence of potential harm. These real-world findings do not support the use of early dexamethasone in hospitalised COVID-19 patients without IRS
Dendritic Morphology of Hippocampal and Amygdalar Neurons in Adolescent Mice Is Resilient to Genetic Differences in Stress Reactivity
Many studies have shown that chronic stress or corticosterone over-exposure in rodents leads to extensive dendritic remodeling, particularly of principal neurons in the CA3 hippocampal area and the basolateral amygdala. We here investigated to what extent genetic predisposition of mice to high versus low stress reactivity, achieved through selective breeding of CD-1 mice, is also associated with structural plasticity in Golgi-stained neurons. Earlier, it was shown that the highly stress reactive (HR) compared to the intermediate (IR) and low (LR) stress reactive mice line presents a phenotype, with respect to neuroendocrine parameters, sleep architecture, emotional behavior and cognition, that recapitulates some of the features observed in patients suffering from major depression. In late adolescent males of the HR, IR, and LR mouse lines, we observed no significant differences in total dendritic length, number of branch points and branch tips, summated tip order, number of primary dendrites or dendritic complexity of either CA3 pyramidal neurons (apical as well as basal dendrites) or principal neurons in the basolateral amygdala. Apical dendrites of CA1 pyramidal neurons were also unaffected by the differences in stress reactivity of the animals; marginally higher length and complexity of the basal dendrites were found in LR compared to IR but not HR mice. In the same CA1 pyramidal neurons, spine density of distal apical tertiary dendrites was significantly higher in LR compared to IR or HR animals. We tentatively conclude that the dendritic complexity of principal hippocampal and amygdala neurons is remarkably stable in the light of a genetic predisposition to high versus low stress reactivity, while spine density seems more plastic. The latter possibly contributes to the behavioral phenotype of LR versus HR animals
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
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