468 research outputs found
Defining the molecular role of gp91phox in the immune manifestation of acute allergic asthma using a preclinical murine model
<p>Abstract</p> <p>Objective</p> <p>The phenomena manifested during inflammation require interplay between circulating effector cells, local resident cells, soluble mediators and genetic host factors to establish, develop and maintain itself. Of the molecues involed in the initiation and perpetuation of acute allergic inflammation in asthma, the involvement of effector cells in redox reactions for producing O<sub>2</sub><sup>- </sup>(superoxide anion) through the mediation of NADPH oxidase is a critical step. Prior data suggest that reactive oxygen species (ROS) produced by NADPH oxidase homologues in non-phagocytic cells play an important role in the regulation of signal transduction, while macrophages use a membrane-associated NADPH oxidase to generate an array of oxidizing intermediates which inactivate MMPs on or near them.</p> <p>Materials and Methods and Treatment</p> <p>To clarify the role of gp91phox subunit of NADPH oxidase in the development and progression of an acute allergic asthma phenotype, we induced allergen dependent inflammation in a gp91<it><sup>phox</sup></it>-/- single knockout and a gp91phox-/-MMP-12-/- double knockout mouse models.</p> <p>Results</p> <p>In the knockout mice, both inflammation and airway hyperreactivity were more extensive than in wildtype mice post-OVA. Although OVA-specific IgE in plasma were comparable in wildtype and knockout mice, enhanced inflammatory cell recruitment from circulation and cytokine release in lung and BALf, accompanied by higher airway resistance as well as Penh in response to methacholine, indicate a regulatory role for NADPH oxidase in development of allergic asthma. While T cell mediated functions like Th2 cytokine secretion, and proliferation to OVA were upregulated synchronous with the overall robustness of the asthma phenotype, macrophage upregulation in functions such as proliferation, and mixed lymphocyte reaction indicate a regulatory role for gp91phox and an overall non-involvement or synergistic involvement of MMP12 in the response pathway (comparing data from gp91phox-/- and gp91phox-/-MMP-12-/- mice).</p
Luxación aislada de la articulación radiocubital distal : Un nuevo caso
Se presenta 1 caso de luxación dorsal aislada de la articulación radiocubital distal
en un paciente varón de 18 años que sufrió una caída sobre la mano izquierda en posición de pronación
del antebrazo. Fue tratado mediante reducción cerrada bajo anestesia local y posterior
inmovilización en un yeso braquioantcbraquial con el codo en 90° de flexión y el antebrazo en supinación
durante 6 semanas. El resultado tras el tratamiento rehabilitador posterior a la retirada
del yeso fue satisfactorio, sin dolor ni alteraciones estéticas ni funcionales en la extremidad.A case of isolated dislocation of the distal radioulnar joint is presented. A 18-yearold
man felt on his left hand with the forearm in pronation. The treatment consisted of closed reduction
and cast inmobilization of the upper extremity with the elbow in 90° of flexion and the forearm
in supination during 6 weeks. The result after this treatment was excellent
Non-symplectic symmetries and bi-Hamiltonian structures of the rational Harmonic Oscillator
The existence of bi-Hamiltonian structures for the rational Harmonic
Oscillator (non-central harmonic oscillator with rational ratio of frequencies)
is analyzed by making use of the geometric theory of symmetries. We prove that
these additional structures are a consequence of the existence of dynamical
symmetries of non-symplectic (non-canonical) type. The associated recursion
operators are also obtained.Comment: 10 pages, submitted to J. Phys. A:Math. Ge
Resonances, Unstable Systems and Irreversibility: Matter Meets Mind
The fundamental time-reversal invariance of dynamical systems can be broken
in various ways. One way is based on the presence of resonances and their
interactions giving rise to unstable dynamical systems, leading to well-defined
time arrows. Associated with these time arrows are semigroups bearing time
orientations. Usually, when time symmetry is broken, two time-oriented
semigroups result, one directed toward the future and one directed toward the
past. If time-reversed states and evolutions are excluded due to resonances,
then the status of these states and their associated backwards-in-time oriented
semigroups is open to question. One possible role for these latter states and
semigroups is as an abstract representation of mental systems as opposed to
material systems. The beginnings of this interpretation will be sketched.Comment: 9 pages. Presented at the CFIF Workshop on TimeAsymmetric Quantum
Theory: The Theory of Resonances, 23-26 July 2003, Instituto Superior
Tecnico, Lisbon, Portugal; and at the Quantum Structures Association Meeting,
7-22 July 2004, University of Denver. Accepted for publication in the
Internation Journal of Theoretical Physic
Testing the AGB Scenario as the Origin of the Extreme-Helium Population in omega Centauri
The most massive Galactic globular cluster, Omega centauri, appears to have
multiple populations. Its bluest main sequence and extended horizontal branch
stars are suggested to have the common origin, that is, an extremely high
helium abundance of Y ~ 0.4. The high helium abundance is most often attributed
to asymptotic giant branch (AGB) stars. In this study we test the AGB
hypothesis. We simulate the maximum-AGB models where the impact of AGB stars is
maximised by assuming that supernova explosions do not affect the chemical
evolution of the proto cloud. We compare the enrichment history of helium,
metals, carbon and nitrogen to the observed values. Even under the most
generous condition, the maximum-AGB models fail to reproduce the large values
of helium Y ~ 0.4 and helium enrichment parameter Delta Y / Delta Z ~ 70 which
were deduced from the colour-magnitude diagram fits. They also fail to
reproduce the C and N contents of the blue population spectroscopically
determined. We conclude that the AGB scenario with the canonical stellar
evolution theory cannot explain the observational constraints and that the self
chemical enrichment does not provide a viable solution. Alternative processes
are desperately called for.Comment: 6 pages, 5 figures, Accepted by MNRA
Exploring the intersections of immigrant seniors’ digital literacies and social connectedness: a Canadian study
Seniors’ adoption of emerging technologies is crucial to their social connectedness, well-being, and digital participation in society. This article presents a Canadian study on how immigrant seniors established and sustained social connections through their engagement with digital technologies during the COVID-19 pandemic. Specifically, we aim to (1) deepen understandings of how immigrant seniors’ learning through and about technologies can shed light on our conceptualization of seniors’ digital literacies and (2) suggest programs and pedagogies that could foster lifelong learning for seniors. Data were collected through interviews, observations, and digital artifacts from a sample of immigrant seniors (N:16). Through narrative, we stitch together the personal and sociocultural perspectives from four seniors’ stories for holistic insights into their learning and engagement with technologies. Their stories also emphasize possibilities for dynamic and interconnected digital engagement and the inseparable link between community support and developing seniors’ digital literacy. Social interaction plays a pivotal role in facilitating, fostering, promoting, and enhancing seniors’ digital literacies. Our findings challenge preconceived notions about how seniors navigate digital technologies and offer strategies for supporting community service agencies in designing and implementing senior-friendly digital literacy programs
On singular Lagrangians affine in velocities
The properties of Lagrangians affine in velocities are analyzed in a
geometric way. These systems are necessarily singular and exhibit, in general,
gauge invariance. The analysis of constraint functions and gauge symmetry leads
us to a complete classification of such Lagrangians.Comment: AMSTeX, 22 page
El síndrome facetar lumbar: Tratamiento mediante infiltraciones facetarias con fenol
Se presenta una serie de 125 pacientes afectos de cuadro de lumbociatalgia atípica, diagnosticados de síndrome facetario y tratados con infiltraciones de solución fenolada en las articulaciones interapofisarias posteriores afectadas, seguidas de un programa de rehabilitación protocolizado tras las infiltraciones. A propósito de los mismos y tras una análisis estadístico de los datos obtenidos del estudio, se establecen algunos criterios para el tratamiento de pacientes aquejados de este tipo de patología.The authors present a series of 125 patients afflicted with an atypical sciatic low-back pain, who were diagnosed of "facet joint syndrome" and treated with injections of phenol solution in the affected lumbar zygapophysial joints. The patients followed a protocolized rehabilitation program. After an statistical analysis of the data obtained from the study, some criteria are stabilized for the treatment of patients suffering this pathology
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