2,815 research outputs found
Rodent models of cardiopulmonary disease: their potential applicability in studies of air pollutant susceptibility.
The mechanisms by which increased mortality and morbidity occur in individuals with preexistent cardiopulmonary disease following acute episodes of air pollution are unknown. Studies involving air pollution effects on animal models of human cardiopulmonary diseases are both infrequent and difficult to interpret. Such models are, however, extensively used in studies of disease pathogenesis. Primarily they comprise those developed by genetic, pharmacologic, or surgical manipulations of the cardiopulmonary system. This review attempts a comprehensive description of rodent cardiopulmonary disease models in the context of their potential application to susceptibility studies of air pollutants regardless of whether the models have been previously used for such studies. The pulmonary disease models include bronchitis, emphysema, asthma/allergy, chronic obstructive pulmonary disease, interstitial fibrosis, and infection. The models of systemic hypertension and congestive heart failure include: those derived by genetics (spontaneously hypertensive, Dahl S. renin transgenic, and other rodent models); congestive heart failure models derived by surgical manipulations; viral myocarditis; and cardiomyopathy induced by adriamycin. The characteristic pathogenic features critical to understanding the susceptibility to inhaled toxicants are described. It is anticipated that this review will provide a ready reference for the selection of appropriate rodent models of cardiopulmonary diseases and identify not only their pathobiologic similarities and/or differences to humans but also their potential usefulness in susceptibility studies
Efficient Transfer of Genes into Murine Cardiac Grafts by Starburst Polyamidoamine Dendrimers
Overview summary Plasmid-mediated gene therapy has been used to deliver immunosuppressive molecules into allografts to prolong graft survival. However, direct injection of naked plasmid DNA is inefficient because transgene expression is low and transient. This study investigated the ability of Starburst dendrimers to augment plasmid-mediated gene transfer efficiency in a murine cardiac transplantation model. The results demonstrate that dendrimers increased the efficiency of transfer and expression of exogenous DNA in cardiac grafts. Improved expression of an immunosuppressive cytokine viral interleukin-10 (vIL-10) by dendrimers significantly prolonged allograft survival. The dose of DNA, the charge ratio of DNA to dendrimer, and the size generation of the dendrimers were all critical for prolongation of allograft survival. Thus, the use of the Starburst dendrimer as a carrier molecule for plasmid-mediated gene transfer improved the efficiency of transfer and expression, providing further therapeutic value for treatment of cardiac allograft rejection.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63156/1/hum.1998.9.4-553.pd
fMRI of reward processing in a community-based longitudinal study
Up to 40% of youth with autism spectrum disorder (ASD) also suffer from
anxiety, and this comorbidity is linked with significant functional
impairment. However, the mechanisms of this overlap are poorly understood. We
investigated the interplay between ASD traits and anxiety during reward
processing, known to be affected in ASD, in a community sample of 1472
adolescents (mean age=14.4 years) who performed a modified monetary incentive
delay task as part of the Imagen project. Blood-oxygen-level dependent (BOLD)
responses to reward anticipation and feedback were compared using a 2x2
analysis of variance test (ASD traits: low/high; anxiety symptoms: low/high),
controlling for plausible covariates. In addition, we used a longitudinal
design to assess whether neural responses during reward processing predicted
anxiety at 2-year follow-up. High ASD traits were associated with reduced BOLD
responses in dorsal prefrontal regions during reward anticipation and negative
feedback. Participants with high anxiety symptoms showed increased lateral
prefrontal responses during anticipation, but decreased responses following
feedback. Interaction effects revealed that youth with combined ASD traits and
anxiety, relative to other youth, showed high right insula activation when
anticipating reward, and low right-sided caudate, putamen, medial and lateral
prefrontal activations during negative feedback (all clusters PFWE<0.05). BOLD
activation patterns in the right dorsal cingulate and right medial frontal
gyrus predicted new-onset anxiety in participants with high but not low ASD
traits. Our results reveal both quantitatively enhanced and qualitatively
distinct neural correlates underlying the comorbidity between ASD traits and
anxiety. Specific neural responses during reward processing may represent a
risk factor for developing anxiety in ASD youth
Balloon-Expandable Stent Treatment of Experimental Coarctation of the Aorta: Early Hemodynamic and Pathological Evaluation
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72292/1/j.1540-8183.1993.tb00843.x.pd
Multiwavelength Observations of the Gamma-Ray Blazar PKS 0528+134 in Quiescence
We present multiwavelength observations of the ultraluminous blazar-type
radio loud quasar PKS 0528+134 in quiescence during the period July to December
2009. Significant flux variability on a time scale of several hours was found
in the optical regime, accompanied by a weak trend of spectral softening with
increasing flux. We suggest that this might be the signature of a contribution
from the accretion disk at the blue end of the optical spectrum. The optical
flux is weakly polarized with rapid variations of the degree and direction of
polarization, while the polarization of the 43 GHz radio core remains steady.
Optical spectropolarimetry suggests a trend of increasing degree of
polarization with increasing wavelength, providing additional evidence for an
accretion disc contribution towards the blue end of the optical spectrum. We
constructed four SEDs indicating that even in the quiescent state, the
bolometric luminosity of PKS 0528+134 is dominated by its gamma-ray emission. A
leptonic single-zone jet model produced acceptable fits to the SEDs with
contributions to the high-energy emission from synchrotron self-Compton
radiation and Comptonization of direct accretion disk emission. Fit parameters
close to equipartition were obtained. The moderate variability on long time
scales implies the existence of on-going particle acceleration, while the
observed optical polarization variability seems to point towards a turbulent
acceleration process. Turbulent particle acceleration at stationary features
along the jet therefore appears to be a viable possibility for the quiescent
state of PKS 0528+134.Comment: Accepted for Publication in The Astrophysical Journal. -
Acknowledgement adde
Evidence for Exotic J^{PC}=1^{-+} Meson Production in the Reaction pi- p --> eta pi- p at 18 GeV/c
Details of the analysis of the eta pi- system studied in the reaction pi^{-}
p --> eta pi^{-} p at 18 GeV/c are given. Separate analyses for the 2 gamma and
pi+ pi- pi0 decay modes of the eta are presented. An amplitude analysis of the
data indicates the presence of interference between the a(2)(1320)- and a
J^{PC}=1^{-+} wave between 1.2 and 1.6 GeV/c^2. The phase difference between
these waves shows phase motion not attributable solely to the a(2)(1320)-. The
data can be fitted by interference between the a(2)(1320)- and an exotic 1^{-+}
resonance with M = 1370 +-16 +50 -30} MeV/c^2 and Gamma = 385 +- 40 +65 -105
MeV/c^2. Our results are compared with those of other experiments.Comment: 50 pages of text and 34 figure
Sagopilone (ZK-EPO, ZK 219477) for recurrent glioblastoma. A phase II multicenter trial by the European Organisation for Research and Treatment of Cancer (EORTC) Brain Tumor Group
Background: Sagopilone (ZK 219477), a lipophylic and synthetic analog of epothilone B, that crosses the blood-brain barrier has demonstrated preclinical activity in glioma models. Patients and methods: Patients with first recurrence/progression of glioblastoma were eligible for this early phase II and pharmacokinetic study exploring single-agent sagopilone (16 mg/m2 over 3 h every 21 days). Primary end point was a composite of either tumor response or being alive and progression free at 6 months. Overall survival, toxicity and safety and pharmacokinetics were secondary end points. Results: Thirty-eight (evaluable 37) patients were included. Treatment was well tolerated, and neuropathy occurred in 46% patients [mild (grade 1) : 32%]. No objective responses were seen. The progression-free survival (PFS) rate at 6 months was 6.7% [95% confidence interval (CI) 1.3-18.7], the median PFS was just over 6 weeks, and the median overall survival was 7.6 months (95% CI 5.3-12.3), with a 1-year survival rate of 31.6% (95% CI 17.7-46.4). Maximum plasma concentrations were reached at the end of the 3-h infusion, with rapid declines within 30 min after termination. Conclusions: No evidence of relevant clinical antitumor activity against recurrent glioblastoma could be detected. Sagopilone was well tolerated, and moderate-to-severe peripheral neuropathy was observed in despite prolonged administratio
Identifying the Location in the Host Galaxy of the Short GRB 111117A with the Chandra Sub-arcsecond Position
We present our successful Chandra program designed to identify, with
sub-arcsecond accuracy, the X-ray afterglow of the short GRB 111117A, which was
discovered by Swift and Fermi. Thanks to our rapid target of opportunity
request, Chandra clearly detected the X-ray afterglow, though no optical
afterglow was found in deep optical observations. The host galaxy was clearly
detected in the optical and near-infrared band, with the best photometric
redshift of z=1.31_{-0.23}^{+0.46} (90% confidence), making it one of the
highest known short GRB redshifts. Furthermore, we see an offset of 1.0 +- 0.2
arcseconds, which corresponds to 8.4 +- 1.7 kpc, between the host and the
afterglow position. We discuss the importance of using Chandra for obtaining
sub-arcsecond X-ray localizations of short GRB afterglows to study GRB
environments.Comment: 17 pages, 11 figures, accepted for publication in Ap
Genetic inhibition of neurotransmission reveals role of glutamatergic input to dopamine neurons in high-effort behavior
Midbrain dopamine neurons are crucial for many behavioral and cognitive functions. As the major excitatory input, glutamatergic afferents are important for control of the activity and plasticity of dopamine neurons. However, the role of glutamatergic input as a whole onto dopamine neurons remains unclear. Here we developed a mouse line in which glutamatergic inputs onto dopamine neurons are specifically impaired, and utilized this genetic model to directly test the role of glutamatergic inputs in dopamine-related functions. We found that while motor coordination and reward learning were largely unchanged, these animals showed prominent deficits in effort-related behavioral tasks. These results provide genetic evidence that glutamatergic transmission onto dopaminergic neurons underlies incentive motivation, a willingness to exert high levels of effort to obtain reinforcers, and have important implications for understanding the normal function of the midbrain dopamine system.Fil: Hutchison, M. A.. National Institutes of Health; Estados UnidosFil: Gu, X.. National Institutes of Health; Estados UnidosFil: Adrover, MartĂn Federico. National Institutes of Health; Estados Unidos. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Investigaciones en IngenierĂa GenĂ©tica y BiologĂa Molecular "Dr. HĂ©ctor N. Torres"; ArgentinaFil: Lee, M. R.. National Institutes of Health; Estados UnidosFil: Hnasko, T. S.. University of California at San Diego; Estados UnidosFil: Alvarez, V. A.. National Institutes of Health; Estados UnidosFil: Lu, W.. National Institutes of Health; Estados Unido
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