534 research outputs found
Post-Tracheal Extubation Pulmonary Oedema. Case Report
O edema agudo do pulmão pós-extubação traqueal é um acontecimento raro (≈ 0,1%)1. A etiologia é multifactorial, sendo a obstrução da via aérea superior o
factor desencadeante principal. O esforço inspiratório contra a glote encerrada causa pressões intra torácicas muito negativas, que se transmitem ao interstício pulmonar,
condicionando uma transudação de fluidos a
partir dos vasos capilares pulmonares1-5. Relatamos um caso de edema agudo do pulmão pós-extubação num doente de quinze anos, operado no serviço de urgência por amputação traumática da perna esquerda. Revemos a fisiopatologia, o padrão radiológico,
potenciais factores de risco e medidas preventivas desta complicação respiratória pós-anestésica
Alternative structures and bi-Hamiltonian systems on a Hilbert space
We discuss transformations generated by dynamical quantum systems which are
bi-unitary, i.e. unitary with respect to a pair of Hermitian structures on an
infinite-dimensional complex Hilbert space. We introduce the notion of
Hermitian structures in generic relative position. We provide few necessary and
sufficient conditions for two Hermitian structures to be in generic relative
position to better illustrate the relevance of this notion. The group of
bi-unitary transformations is considered in both the generic and non-generic
case. Finally, we generalize the analysis to real Hilbert spaces and extend to
infinite dimensions results already available in the framework of
finite-dimensional linear bi-Hamiltonian systems.Comment: 11 page
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The interplay between redox signalling and proteostasis in neurodegeneration: In vivo effects of a mitochondria-targeted antioxidant in Huntington's disease mice.
Abnormal protein homeostasis (proteostasis), dysfunctional mitochondria, and aberrant redox signalling are often associated in neurodegenerative disorders, such as Huntington's (HD), Alzheimer's and Parkinson's diseases. It remains incompletely understood, however, how changes in redox signalling affect proteostasis mechanisms, including protein degradation pathways and unfolded protein responses (UPR). Here we address this open question by investigating the interplay between redox signalling and proteostasis in a mouse model of HD, and by examining the in vivo effects of the mitochondria-targeted antioxidant MitoQ. We performed behavioural tests in wild-type and R6/2 HD mice, examined markers of oxidative stress, UPR activation, and the status of key protein degradation pathways in brain and peripheral tissues. We show that R6/2 mice present widespread markers of oxidative stress, with tissue-specific changes in proteostasis that were more pronounced in the brain and muscle than in the liver. R6/2 mice presented increased levels of cytosolic and mitochondrial chaperones, particularly in muscle, indicating UPR activation. Treatment with MitoQ significantly ameliorated fine motor control of R6/2 mice, and reduced markers of oxidative damage in muscle. Additionally, MitoQ attenuated overactive autophagy induction in the R6/2 muscle, which has been associated with muscle wasting. Treatment with MitoQ did not alter autophagy markers in the brain, in agreement with its low brain bioavailability, which limits the risk of impairing neuronal protein clearance mechanisms. This study supports the hypotheses that abnormal redox signalling in muscle contributes to altered proteostasis and motor impairment in HD, and that redox interventions can improve muscle performance, highlighting the importance of peripheral therapeutics in HD
Safety of etanercept in the treatment of rheumatic disease patients with Hepatitis C virus infection
info:eu-repo/semantics/publishedVersio
Can we rely on iFR for avoiding FFR? Conclusions of a 5-year experience
Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017Background: Recently, the instantaneous wave free ratio (iFR), has been proposed an alternative or complementary method to fractional flow reserve (FFR). This new method does not require the use of adenosine and may expedite the speed of functional assessment. The iFR “hybrid strategy” relies on values 0,93 as definitive results which would not require the use of FFR. However, this strategy is much less consensual than FFR alone.
Purpose: We aimed to assess the concordance of FFR and iFR results using the principle of the “hybrid strategy”, based on the 5-year experience of a single center. We also aimed to analyse the effect of iFR in the operator's decision to proceed to FFR, and its impact on procedure duration and radiation time/dosage.
Methods: Single-center registry of all patients undergoing functional coronary lesion assessment during 5 years. FFR was used as a gold standard (with a cut-off point for intervention ≤0,80) for assessing the diagnostic accuracy of iFR in every patient who underwent measurements with both techniques.
For analysis purposes, an iFR value 0,93 was considered negative (i.e. defer intervention). Values in between were deemed inconclusive. For statistical analysis we used the T student and Chi-Square tests.
Results: Functional testing was undertaken in 326 patients (67±11 years, 65,6% male), encompassing 402 lesions. 154 lesions underwent assessment with both techniques, 222 by FFR only and 26 cases iFR only.
The average iFR was 0,9±0,1. 60 lesions had an iFR >0,93 and 21 an iFR <0,86.
An iFR value between 0,86 and 0,93 was strongly associated with the decision to proceed to FFR (χ2=30,1; p0,93 (71,4% vs 68%; p=0,792). In these cases, there was a statistically significant concordance of 87% between the iFR and FFR results (χ2=22,43; p<0,001). Notwithstanding, there were 4 out of 13 cases (30,7%) of positive iFR with negative FFR and 3 out of 42 (7,1%) cases of negative iFR and positive FFR. This difference was statistically significant (p=0,026).
Regarding procedural time, radiation time and radiation dose, there were no statistically significant differences between patients who only underwent iFR, FFR only, or both techniques.
Conclusions: The iFR results were inconclusive (i.e. between 0,86 and 0,93) in most cases. There was a high degree of concordance between the iFR and FFR values. However, a significant proportion of patients, particularly in cases of positive iFR (<0,86), were classified as negative by FFR. The use of iFR had no impact on procedural time, radiation time and radiation dose.info:eu-repo/semantics/publishedVersio
Influence of steps on the tilting and adsorption dynamics of ordered Pn films on vicinal Ag(111) surfaces
Here we present a structural study of pentacene (Pn) thin films on vicinal
Ag(111) surfaces by He atom diffraction measurements and density functional
theory (DFT) calculations supplemented with van der Waals (vdW) interactions.
Our He atom diffraction results suggest initial adsorption at the step edges
evidenced by initial slow specular reflection intensity decay rate as a
function of Pn deposition time. In parallel with the experimental findings, our
DFT+vdW calculations predict the step edges as the most stable adsorption site
on the surface. An isolated molecule adsorbs as tilted on the step edge with a
binding energy of 1.4 eV. In addition, a complete monolayer (ML) with
pentacenes flat on the terraces and tilted only at the step edges is found to
be more stable than one with all lying flat or tilted molecules, which in turn
influences multilayers. Hence our results suggest that step edges can trap Pn
molecules and act as nucleation sites for the growth of ordered thin films with
a crystal structure similar to that of bulk Pn.Comment: 4 pages, 4 figures, 1 tabl
A functional genomic approach to identify reference genes for human pancreatic beta cell real-time quantitative RT-PCR analysis
Exposure of human pancreatic beta cells to pro-inflammatory cytokines or metabolic stressors is used to model events related to type 1 and type 2 diabetes, respectively. Quantitative real-time PCR is commonly used to quantify changes in gene expression. The selection of the most adequate reference gene(s) for gene expression normalization is an important pre-requisite to obtain accurate and reliable results. There are no universally applicable reference genes, and the human beta cell expression of commonly used reference genes can be altered by different stressors. Here we aimed to identify the most stably expressed genes in human beta cells to normalize quantitative real-time PCR gene expression. We used comprehensive RNA-sequencing data from the human pancreatic beta cell line EndoC-βH1, human islets exposed to cytokines or the free fatty acid palmitate in order to identify the most stably expressed genes. Genes were filtered based on their level of significance (adjusted P-value >0.05), fold-change (|fold-change| <1.5) and a coefficient of variation <10%. Candidate reference genes were validated by quantitative real-time PCR in independent samples. We identified a total of 264 genes stably expressed in EndoC-βH1 cells and human islets following cytokines–or palmitate-induced stress, displaying a low coefficient of variation. Validation by quantitative real-time PCR of the top five genes ARF1, CWC15, RAB7A, SIAH1 and VAPA corroborated their expression stability under most of the tested conditions. Further validation in independent samples indicated that the geometric mean of ACTB and VAPA expression can be used as a reliable normalizing factor in human beta cells
Overexpression of adenosine A2A receptors in rats: effects on depression, locomotion, and anxiety
Adenosine A2A receptors (A2AR) are a sub-type of receptors enriched in basal ganglia, activated by the neuromodulator adenosine, which interact with dopamine D2 receptors. Although this reciprocal antagonistic interaction is well-established in motor function, the outcome in dopamine-related behaviors remains uncertain, in particular in depression and anxiety. We have demonstrated an upsurge of A2AR associated to aging and chronic stress. Furthermore, Alzheimer's disease patients present A2AR accumulation in cortical areas together with depressive signs. We now tested the impact of overexpressing A2AR in forebrain neurons on dopamine-related behavior, namely depression. Adult male rats overexpressing human A2AR under the control of CaMKII promoter [Tg(CaMKII-hA2AR)] and aged-matched wild-types (WT) of the same strain (Sprague-Dawley) were studied. The forced swimming test (FST), sucrose preference test (SPT), and the open-field test (OFT) were performed to evaluate behavioral despair, anhedonia, locomotion, and anxiety. Tg(CaMKII-hA2AR) animals spent more time floating and less time swimming in the FST and presented a decreased sucrose preference at 48 h in the SPT. They also covered higher distances in the OFT and spent more time in the central zone than the WT. The results indicate that Tg(CaMKII-hA2AR) rats exhibit depressive-like behavior, hyperlocomotion, and altered exploratory behavior. This A2AR overexpression may explain the depressive signs found in aging, chronic stress, and Alzheimer's disease
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