381 research outputs found
The inflammatory response in the regression of lumbar disc herniation
Lumbar disc herniation (LDH) is highly associated with inflammation in the context of low back pain. Currently, inflammation is associated with adverse symptoms related to the stimulation of nerve fibers that may lead to pain. However, inflammation has also been indicated as the main factor responsible for LDH regression. This apparent controversy places inflammation as a good prognostic indicator of spontaneous regression of LDH. This review addresses the molecular and cellular mechanisms involved in LDH regression, including matrix remodeling and neovascularization, in the scope of the clinical decision on conservative versus surgical intervention. Based on the evidence, a special focus on the inflammatory response in the LDH context is given, particularly in the monocyte/macrophage role. The phenomenon of spontaneous regression of LDH, extensively reported in the literature, is therefore analyzed here under the perspective of the modulatory role of inflammation.This work was financed by project “Bioengineered Therapies for infectious diseases and tissue regeneration” (NORTE-01-0145-FEDER-000012), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), by FEDER/COMPETE 2020 (POCI), Portugal 2020, and by Portuguese funds through FCT/MCTES in the framework of the project "Institute for Research and Innovation in Health Sciences" (POCI-01- 0145-FEDER-007274). Cunha C and Gonçalves RM acknowledge FCT by their postdoc fellowship (SFRH/BDP/87071/2012) and FCT Investigator Grant (IF/ 00638/2014), respectively. Silva AJ acknowledges her fellowship under the framework of the project Norte-01-0145-FEDER-000012
Immunoglobulin genes implicated in glioma risk
Both genetic and environmental factors are thought to be causal in gliomagenesis. Several genes have been implicated in glioma development, but the putative role of a major immunity-related gene complex member, immunoglobulin heavy chain γ (IGHG) has not been evaluated. Prior observations that IGHG-encoded γ marker (GM) allotypes exhibit differential sensitivity to an immunoevasion strategy of cytomegalovirus, a pathogen implicated as a promoter of gliomagenesis, has lead us to hypothesize that these determinants are risk factors for glioma. To test this hypothesis, we genotyped the IGHG locus comprising the GM alleles, specifically GM alleles 3 and 17, of 120 glioma patients and 133 controls via TaqMan® genotyping assay. To assess the associations between GM genotypes and the risk of glioma, we applied an unconditional multivariate logistic regression analysis adjusted for potential confounding variables. In comparison to subjects who were homozygous for the GM 17 allele, the GM 3 homozygotes were over twice as likely, and the GM 3/17 heterozygotes were over three times as likely, to develop glioma. Similar results were achieved when analyzed by combining the data corresponding to alleles GM 3 and GM 3/17 in a dominant model. The GM 3/17 genotype and the combination of GM 3 and GM 3/17 were found to be further associated with over 3 times increased risk for high-grade astrocytoma (grades III-IV). Allele frequency analyses also showed an increased risk for gliomas and high-grade astrocytoma in association with GM 3. Our findings support the premise that the GM 3 allele may present risk for the development of glioma, possibly by modulating immunity to cytomegalovirus
Analysis of the Cochrane Review: Exercise-Based Cardiac Rehabilitation for Coronary Heart Disease. Cochrane Database Syst Rev. 2016;1:CD001800
A doença coronária, responsável por um terço de todas as mortes, Ă© a causa de morte mais comum em todo o mundo. Todavia, com o decrĂ©scimo das taxas de mortalidade associadas a esta patologia, observa-se um nĂşmero crescente de doentes com a doença, com aumento da necessidade de gestĂŁo dos seus sintomas e prognĂłstico. A reabilitação cardĂaca, componente essencial do tratamento contemporâneo da doença arterial coronária, Ă© uma intervenção complexa que envolve variadas tĂ©cnicas, incluindo exercĂcio fĂsico, correção dos fatores de risco cardiovasculares tradicionais, terapia comportamental e apoio psicolĂłgico, sendo considerada uma prioridade em paĂses em que a prevalĂŞncia da doença Ă© elevada. Esta revisĂŁo sistemática Cochrane constitui uma atualização de uma revisĂŁo Cochrane publicada em 2011, tendo identificado 16 novos ensaios clĂnicos (3872 doentes), predominantemente em status pĂłs-enfarte agudo do miocárdio e pĂłs-cirurgia de revascularização miocárdica. Incluiu, assim, 63 ensaios clĂnicos aleatorizados que estudaram a eficácia e o custo-efetividade da reabilitação cardĂaca baseada no exercĂcio fĂsico, em pacientes com doença arterial
coronária. A confiança na evidĂŞncia cientĂfica variou de baixa a moderada. Dos principais resultados destaca-se o efeito da reabilitação cardĂaca, em comparação com a ausĂŞncia de exercĂcio fĂsico, na redução na mortalidade cardiovascular, todavia sem redução da mortalidade total. Apesar da reabilitação cardĂaca ter diminuĂdo o risco global de internamento hospitalar, o mesmo nĂŁo se verificou para o risco de enfarte, cirurgia de revascularização miocárdica ou intervenção coronária percutânea. Neste artigo sumarizam-se e discutem-se os principais resultados, conclusões e implicações desta revisĂŁo sistemática para a prática clĂnica.info:eu-repo/semantics/publishedVersio
Quantization of Midisuperspace Models
We give a comprehensive review of the quantization of midisuperspace models.
Though the main focus of the paper is on quantum aspects, we also provide an
introduction to several classical points related to the definition of these
models. We cover some important issues, in particular, the use of the principle
of symmetric criticality as a very useful tool to obtain the required
Hamiltonian formulations. Two main types of reductions are discussed: those
involving metrics with two Killing vector fields and spherically symmetric
models. We also review the more general models obtained by coupling matter
fields to these systems. Throughout the paper we give separate discussions for
standard quantizations using geometrodynamical variables and those relying on
loop quantum gravity inspired methods.Comment: To appear in Living Review in Relativit
Effects of the functional HOTAIR rs920778 and rs12826786 genetic variants in glioma susceptibility and patient prognosis
Abnormal expression of the long non-coding RNA HOX transcript antisense intergenic RNA (HOTAIR) is oncogenic in several human cancers, including gliomas. The HOTAIR single nucleotide polymorphisms (SNPs) rs920778 (C > T) and rs12826786 (C > T) present in the intronic enhancer and promoter regions of HOTAIR, respectively, are associated with expression, cancer susceptibility, and patient prognosis in some tumor types. However, the relevance of these HOTAIR SNPs has not been studied in glioma. Here, we report a case-control study comprising 177 Portuguese glioma patients and 199 cancer-free controls. All subjects were genotyped by PCR and restriction fragment length polymorphism (RFLP). No statistically significant differences were found in the genotype or allele distributions of either rs920778 or rs12826786 between glioma patients and controls, suggesting these SNPs are not associated with glioma risk. No significant associations were found between rs920778 variants and HOTAIR expression levels, while rs12826786 CT genotype was associated with increased intratumoral HOTAIR RNA levels when compared to TT genotype (p-value = 0.04). Univariate (Log-rank) and multivariate (Cox proportional) analyses showed both rs920778 CT and rs12826786 CT genotypes were significantly associated with longer overall survival of WHO grade III anaplastic oligodendroglioma patients. Our results suggest that HOTAIR SNPs rs920778 and rs12826786 do not play a significant role in glioma susceptibility, but may be important prognostic factors in anaplastic oligodendroglioma patients. Future studies are warranted to validate and expand these findings, and to further dissect the importance of these SNPs in glioma.info:eu-repo/semantics/publishedVersio
Accurate masses and radii of normal stars: modern results and applications
This paper presents and discusses a critical compilation of accurate,
fundamental determinations of stellar masses and radii. We have identified 95
detached binary systems containing 190 stars (94 eclipsing systems, and alpha
Centauri) that satisfy our criterion that the mass and radius of both stars be
known to 3% or better. To these we add interstellar reddening, effective
temperature, metal abundance, rotational velocity and apsidal motion
determinations when available, and we compute a number of other physical
parameters, notably luminosity and distance. We discuss the use of this
information for testing models of stellar evolution. The amount and quality of
the data also allow us to analyse the tidal evolution of the systems in
considerable depth, testing prescriptions of rotational synchronisation and
orbital circularisation in greater detail than possible before. The new data
also enable us to derive empirical calibrations of M and R for single (post-)
main-sequence stars above 0.6 M(Sun). Simple, polynomial functions of T(eff),
log g and [Fe/H] yield M and R with errors of 6% and 3%, respectively.
Excellent agreement is found with independent determinations for host stars of
transiting extrasolar planets, and good agreement with determinations of M and
R from stellar models as constrained by trigonometric parallaxes and
spectroscopic values of T(eff) and [Fe/H]. Finally, we list a set of 23
interferometric binaries with masses known to better than 3%, but without
fundamental radius determinations (except alpha Aur). We discuss the prospects
for improving these and other stellar parameters in the near future.Comment: 56 pages including figures and tables. To appear in The Astronomy and
Astrophysics Review. Ascii versions of the tables will appear in the online
version of the articl
Globally convergent evolution strategies for constrained optimization
International audienceIn this paper we propose, analyze, and test algorithms for constrained optimization when no use of derivatives of the objective function is made. The proposed methodology is built upon the globally convergent evolution strategies previously introduced by the authors for unconstrained optimization. Two approaches are encompassed to handle the constraints. In a first approach, feasibility is first enforced by a barrier function and the objective function is then evaluated directly at the feasible generated points. A second approach projects first all the generated points onto the feasible domain before evaluating the objective function.The resulting algorithms enjoy favorable global convergence properties (convergence to stationarity from arbitrary starting points), regardless of the linearity of the constraints.The algorithmic implementation (i) includes a step where previously evaluated points are used to accelerate the search (by minimizing quadratic models) and (ii) addresses the particular cases of bounds on the variables and linear constraints. Our solver is compared to others, and the numerical results confirm its competitiveness in terms of efficiency and robustness
Anthropogenic disturbance in tropical forests can double biodiversity loss from deforestation
Concerted political attention has focused on reducing deforestation1,2,3, and this remains the cornerstone of most biodiversity conservation strategies4,5,6. However, maintaining forest cover may not reduce anthropogenic forest disturbances, which are rarely considered in conservation programmes6. These disturbances occur both within forests, including selective logging and wildfires7,8, and at the landscape level, through edge, area and isolation effects9. Until now, the combined effect of anthropogenic disturbance on the conservation value of remnant primary forests has remained unknown, making it impossible to assess the relative importance of forest disturbance and forest loss. Here we address these knowledge gaps using a large data set of plants, birds and dung beetles (1,538, 460 and 156 species, respectively) sampled in 36 catchments in the Brazilian state of Pará. Catchments retaining more than 69–80% forest cover lost more conservation value from disturbance than from forest loss. For example, a 20% loss of primary forest, the maximum level of deforestation allowed on Amazonian properties under Brazil’s Forest Code5, resulted in a 39–54% loss of conservation value: 96–171% more than expected without considering disturbance effects. We extrapolated the disturbance-mediated loss of conservation value throughout Pará, which covers 25% of the Brazilian Amazon. Although disturbed forests retained considerable conservation value compared with deforested areas, the toll of disturbance outside Pará’s strictly protected areas is equivalent to the loss of 92,000–139,000 km2 of primary forest. Even this lowest estimate is greater than the area deforested across the entire Brazilian Amazon between 2006 and 2015 (ref. 10). Species distribution models showed that both landscape and within-forest disturbances contributed to biodiversity loss, with the greatest negative effects on species of high conservation and functional value. These results demonstrate an urgent need for policy interventions that go beyond the maintenance of forest cover to safeguard the hyper-diversity of tropical forest ecosystems
How to promote adverse drug reaction reports using information systems – a systematic review and meta-analysis
The decision to emigrate: A study from the perspective of dispositional plurality
This paper analyses the Portuguese high-skilled emigration, focusing on the emigration decision-making process. This article aims to understand the dispositions leading to this decision, and the social processes that explain its origin, sedimentation and activation. To this end, and using the theoretical and methodological approach of Bernard Lahire, 53 sociological portraits of skilled Portuguese who emigrated to other European countries are cross-sectional analyzed. This analysis is supplemented by data from a survey previously administered. Thus, we will address how the migratory dispositions are built through the individual biographies, highlighting the heuristic potential of the individual observation scale
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