1,662 research outputs found
Red alert: labile heme is an alarmin
This publication hasn't any creative commons license associated.This deposit is composed by the main article, and it hasn't any supplementary materials associated. There is no public supplementary material available.The deposited article is a pre-print version.Alarmins are a heterogeneous group of endogenous molecules that signal cellular damage when sensed extracellularly. Heme is an endogenous molecule that acts as a prosthetic group of hemoproteins, such as hemoglobin and myoglobin. When released from damaged red blood cells or muscle cells, oxidized hemoglobin and myoglobin release their prosthetic heme groups, respectively. This generates labile heme, which is sensed by pattern recognition receptors (PRR) expressed by innate immune cells and possibly regulatory T cells (TREG). The ensuing adaptive response, which alerts for the occurrence of red blood cell or muscle cell damage, regulates the pathologic outcome of hemolysis or rhabdomyolysis, respectively. In conclusion, we propose that labile heme is an alarmin.Fundação para a Ciência e Tecnologia grants: (PTDC/SAU TOX/116627/2010, HMSP-ICT/0022/2010, RECI/IMI-IMU/0038/2012); Fundação de Amparo a Pesquisa do Estado do Rio de Janeiro; Conselho Nacional de Pesquisa, INCTDengue, Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior.info:eu-repo/semantics/publishedVersio
Particle motion and gravitational lensing in the metric of a dilaton black hole in a de Sitter universe
We consider the metric exterior to a charged dilaton black hole in a de
Sitter universe. We study the motion of a test particle in this metric.
Conserved quantities are identified and the Hamilton-Jacobi method is employed
for the solutions of the equations of motion. At large distances from the black
hole the Hubble expansion of the universe modifies the effective potential such
that bound orbits could exist up to an upper limit of the angular momentum per
mass for the orbiting test particle. We then study the phenomenon of strong
field gravitational lensing by these black holes by extending the standard
formalism of strong lensing to the non-asymptotically flat dilaton-de Sitter
metric. Expressions for the various lensing quantities are obtained in terms of
the metric coefficients.Comment: 8 pages, RevTex, 1 eps figures; discussion improved; typos corrected;
references adde
Fungal Surface and Innate Immune Recognition of Filamentous Fungi
The innate immune system performs specific detection of molecules from infectious agents through pattern recognition receptors. This recognition triggers inflammatory responses and activation of microbicidal mechanisms by leukocytes. Infections caused by filamentous fungi have increased in incidence and represent an important cause of mortality and morbidity especially in individuals with immunosuppression. This review will discuss the innate immune recognition of filamentous fungi molecules and its importance to infection control and disease
Estimating the parameters of the Sgr A* black hole
The measurement of relativistic effects around the galactic center may allow
in the near future to strongly constrain the parameters of the supermassive
black hole likely present at the galactic center (Sgr A*). As a by-product of
these measurements it would be possible to severely constrain, in addition,
also the parameters of the mass-density distributions of both the innermost
star cluster and the dark matter clump around the galactic center.Comment: Accepted for publication on General Relativity and Gravitation, 2010.
11 Pages, 1 Figur
The role of corticosteroids in severe community-acquired pneumonia: a systematic review
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Previous issue date: 2008Instituto Nacional de Câncer. Unidade de Cuidados Intensivos. Rio de Janeiro, RJ, Brasil / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ, Brasil.Hospital de São Francisco Xavier. Centro Hospitalar de Lisboa Ocidental. Unidade de Terapia Intensiva Médica. Lisboa, Portugal.Instituto Nacional de Câncer. Unidade de Cuidados Intensivos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto de Pesquisa Clínica Evandro Chagas. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunofarmacologia. Rio de Janeiro, RJ, Brasil.Introduction: The purpose of this review was to evaluate the impact of corticosteroids on the outcomes of patients with severe community-acquired pneumonia (CAP). Methods: We performed a systematic MEDLINE, Cochrane database, and CINAHL search (1966 to November 2007) to
identify full-text publications that evaluated the use of corticosteroids in CAP. Results: An initial literature search yielded 109 articles, and 105
studies were excluded after the first analysis. We found four studies eligible for analysis. On the basis of their results, the use of corticosteroids as adjunctive therapy in severe CAP should be categorized as a weak recommendation (two studies) and a strong recommendation (two studies) with either low- or moderate-quality evidence. However, no evidence of adverse outcomes or harm is present in the evaluated studies. Conclusion: According to the GRADE system, available studies do not support the recommendation of corticosteroids as a standard of care for patients with severe CAP. Further randomized controlled trials with this aim should enroll a larger number of severely ill patients. However, in patients needing
corticosteroids, it may be reasonable to conclude that corticosteroid administration is safe in patients with severe infections receiving antimicrobial therapy
Multiplex cytokine profile from dengue patients: MIP-1beta and IFN-gamma as predictive factors for severity
<p>Abstract</p> <p>Background</p> <p>Dengue virus pathogenesis is not yet fully understood and the identification of patients at high risk for developing severe disease forms is still a great challenge in dengue patient care. During the present study, we evaluated prospectively the potential of cytokines present in plasma from patients with dengue in stratifying disease severity.</p> <p>Methods</p> <p>Seventeen-cytokine multiplex fluorescent microbead immunoassay was used for the simultaneous detection in 59 dengue patients. GLM models using bimodal or Gaussian family were determined in order to associate cytokines with clinical manifestations and laboratory diagnosis.</p> <p>Results</p> <p>IL-1β, IFN-γ, IL-4, IL-6, IL-13, IL-7 and GM-CSF were significantly increased in patients with severe clinical manifestations (severe dengue) when compared to mild disease forms (mild dengue). In contrast, increased MIP-1β levels were observed in patients with mild dengue. MIP-1β was also associated with CD56+NK cell circulating rates. IL-1β, IL-8, TNF-α and MCP-1 were associated with marked thrombocytopenia. Increased MCP-1 and GM-CSF levels correlated with hypotension. Moreover, MIP-1β and IFN-γ were independently associated with both dengue severity and disease outcome.</p> <p>Conclusion</p> <p>Our data demonstrated that the use of a multiple cytokine assay platform was suitable for identifying distinct cytokine profiles associated with the dengue clinical manifestations and severity. MIP-β is indicated for the first time as a good prognostic marker in contrast to IFN-γ that was associated with disease severity.</p
Gravitational Lensing by Black Holes
We review the theoretical aspects of gravitational lensing by black holes,
and discuss the perspectives for realistic observations. We will first treat
lensing by spherically symmetric black holes, in which the formation of
infinite sequences of higher order images emerges in the clearest way. We will
then consider the effects of the spin of the black hole, with the formation of
giant higher order caustics and multiple images. Finally, we will consider the
perspectives for observations of black hole lensing, from the detection of
secondary images of stellar sources and spots on the accretion disk to the
interpretation of iron K-lines and direct imaging of the shadow of the black
hole.Comment: Invited article for the GRG special issue on lensing (P. Jetzer, Y.
Mellier and V. Perlick Eds.). 31 pages, 12 figure
Shadows of a maximal acceleration
A quantum mechanical upper limit on the value of particle accelerations, or
maximal acceleration (MA), is applied to compact stars. A few MA fermions are
at most present in canonical white dwarfs and neutron stars. They drastically
alter a star's stability conditions.Comment: 11 page
Strong Gravitational Lensing in a Charged Squashed Kaluza- Klein Black hole
In this paper we investigate the strong gravitational lensing in a charged
squashed Kaluza-Klein black hole. We suppose that the supermassive black hole
in the galaxy center can be considered by a charged squashed Kaluza-Klein black
hole and then we study the strong gravitational lensing theory and estimate the
numerical values for parameters and observables of it. We explore the effects
of the scale of extra dimension and the charge of black hole
on these parameters and observables.Comment: 17 pages, 10 figure
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