Fatores associados ao aumento no índice de incremento de pressão radial em indivíduos hipertensos

FUNDAMENTO: A rigidez arterial é uma variável preditora de morbimortalidade e um possível marcador de lesão vascular. Sua avaliação não invasiva por tonometria radial e análise do índice de incremento (r-AI) permite identificar os pacientes expostos a um maior risco cardiovascular. OBJETIVO: Analisar a influência do r-AI em variáveis clínico-bioquímicas e sua influência na prevalência de dano em órgão-alvo em pacientes hipertensos. MÉTODOS: Cento e quarenta pacientes hipertensos consecutivos, em seguimento clínico ambulatorial, foram submetidos à análise transversal. Os níveis de pressão arterial (PA) e o r-AI foram obtidos por tonometria de aplanação da artéria radial (HEM-9000AI, Onrom). Os pacientes foram alocados em tercis r-AI (r-AI < 85%; 85 < r-AI < 97%; r-AI > 97%). RESULTADOS: A amostra era predominantemente composta por mulheres (56,4%), com idade média de 61,7 ± 11,7 anos e índice de massa corporal de 29,6 ± 6,1 Kg/m². O maior tercil apresentou uma proporção maior de mulheres (p = 0,001), maior PA sistólica (p = 0,001) e pressão de pulso (p = 0,014), e menor peso (p = 0,044), altura (p < 0,001) e frequência cardíaca (p < 0,001). A análise multivariada demonstrou que o peso (β = -0,001, p = 0,017), frequência cardíaca (β = -0,001, p = 0,007) e pressão central (β = 0,015, p < 0,001) se correlacionam com o r-AI de maneira independente. Em análises de regressão logística, o 3º tercil r-AI foi associado a uma diminuição do diabete (DM) (OR = 0,41; 95% CI 0,17-0,97; p = 0,042). CONCLUSÃO: Este estudo demonstrou que peso, frequência cardíaca e PA central se relacionam com o r-AI de maneira independente.

Efeitos da Esqueletização em Comparação com a Manutenção do Pedículo da Artéria Radial sobre a Patência e Fluxo Pós-Operatórios do Enxerto

Fundamento: O enxerto de artéria radial (AR) foi o segundo enxerto arterial a ser introduzido na prática clínica para revascularização miocárdica. A técnica de esqueletização da artéria torácica interna esquerda (ATIE) pode, de fato, alterar a capacidade de fluxo do enxerto com potenciais vantagens, o que leva à suposição de que o comportamento da AR, como enxerto coronariano, seja semelhante ao da ATIE esqueletizada. Objetivo: Este estudo avaliou enxertos aortocoronários "livres" de AR, quer esqueletizados, quer com tecidos adjacentes. Métodos: Foi realizado um estudo prospectivo randomizado comparando 40 pacientes distribuídos em dois grupos. No grupo I, foram utilizadas artérias radiais esqueletizadas (20 pacientes), e no grupo II, artérias radiais com tecidos adjacentes (20 pacientes). Após o procedimento cirúrgico, os pacientes foram submetidos a medidas da velocidade de fluxo. Resultados: As principais variáveis cirúrgicas foram: diâmetro interno, comprimento e fluxo sanguíneo livre da AR. Os diâmetros médios dos enxertos de AR calculados através de angiografia quantitativa no pós-operatório imediato foram semelhantes, assim como as variáveis de medidas de velocidade de fluxo. Por outro lado, a cinecoronariografia mostrou a presença de oclusão em um enxerto de AR e estenose em cinco enxertos de AR no GII, enquanto que apenas um caso de estenose em um enxerto de AR no GI (p = 0,045). Conclusão: Os resultados mostram que tanto as características morfológicas e anatomopatológicas quanto o desempenho hemodinâmico dos enxertos livres de artéria radial, quer preparados de forma esqueletizada ou com tecidos adjacentes, são semelhantes. Entretanto, pode-se observar um maior número de lesões não obstrutivas quando a AR é preparada com tecidos adjacentes.

Femoral versus Radial Access in Primary Angioplasty. Analysis of the ACCEPT Registry

Background:The radial access provides a lower risk of bleeding and vascular complications related to the puncture site in comparison to the femoral access. Recent studies have suggested a reduction in mortality associated with the radial access in patients with acute myocardial infarction undergoing percutaneous coronary intervention.Objective:To compare the occurrence of adverse cardiovascular ischemic and hemorrhagic events in patients undergoing primary angioplasty according to the type of arterial access route.Methods:From August 2010 to December 2011, 588 patients undergoing primary percutaneous coronary intervention during acute ST-segment elevation myocardial infarction were assessed; they were recruited from 47 centers participating in the ACCEPT registry. Patients were grouped and compared according to the arterial access used for the procedure.Results:The mean age was 61.8 years; 75% were males and 24% had diabetes mellitus. There was no difference between groups as regards the procedure success rate, as well as regards the occurrence of death, reinfarction, or stroke at six months of follow-up. Severe bleeding was reported in 1.1% of the sample analyzed, with no statistical difference related to the access used.Conclusions:The femoral and radial accesses are equally safe and effective for the performance of primary percutaneous coronary intervention. The low rate of cardiovascular events and of hemorrhagic complications reflects the quality of the participating centers and the operators expertise with the use of both techniques.

Predictors of Conversion from Radial Into Femoral Access in Cardiac Catheterization

Background: Fewer bleeding complications and early ambulation make radial access a privileged route for cardiac catheterization. However, transradial (TR) approach is not always successful, requiring its conversion into femoral access. Objectives: To evaluate the rate of conversion from radial into femoral access in cardiac catheterization and to identify its predictors. Methods: Prospective dual-center registry, including 7632 consecutive patients undergoing catheterization via the radial access between Jan/2009 and Oct/2012. We evaluated the incidence of conversion into femoral access and its predictors by logistic regression analysis. Results: The patients’ mean age was 66 ± 11 years, and 32% were women. A total of 2969 procedures (38.4%) were percutaneous coronary interventions (PCI), and the most used first intention arterial access was the right radial artery (97.6%). Radial access failure rate was 5.8%. Independent predictors of conversion from radial into femoral access were the use of short introducer sheaths (OR 3.047, CI: 2.380-3.902; p < 0.001), PCI (OR 1.729, CI: 1.375-2.173; p < 0.001), female sex (OR 1.569, CI: 1.234-1.996; p < 0.001), multivessel disease (OR 1.457, CI: 1.167-1.819; p = 0.001), body surface area (BSA) ≤ 1.938 (OR 1.448, CI: 1.120-1.871; p = 0.005) and age > 66 years (OR 1.354, CI: 1.088-1.684; p = 0.007). Conclusion: Transradial approach for cardiac catheterization has a high success rate and the need for its conversion into femoral access in this cohort was low. Female sex, older age, smaller BSA, the use of short introducer sheaths, multivessel disease and PCI were independent predictors of conversion into femoral access.

Glia going emotional : the impact of acute and repeated neonatal separations on astrocytes in the medial prefrontal cortex

Astrocytes, GFAP, glia, neonatal separation, medial prefrontal cortex, S100ß

Optimization of radial jets mixing in cross-flow of combustion chambers using computational fluid dynamics

Cross-Flow, Radial Jets Mixing, Temperature Homogenization, Optimization, Combustion Chamber, CFD

Zell-spezifische, metabolische Markierung von neu synthetisierten Proteinen in einem Neuron-Glia-Netzwerk

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2012

Multi-echo radial FLASH techniques for real-time MRI

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2015

Dispersão larval radial pós-alimentar em Lucilia cuprina (Diptera, Calliphoridae): profundidade, peso e distância de enterramento para pupação

Blowflies utilize discrete and ephemeral sites for breeding and larval nutrition. After the exhaustion of food, the larvae begin dispersing to search for sites to pupate or for additional food source, process referred as postfeeding larval dispersal. Some aspects of this process were investigated in Lucilia cuprina (Wiedemann, 1830), utilizing a circular arena to permit the radial dispersion of larvae from the food source in the center. To determine the localization of each pupa, the arena was split into 72 equal sectors from the center. For each pupa, distance from the center of arena, weight and depth were determined. Statistical tests were performed to verify the relation among weight, depth and distance of burying for pupation. It was verified that the larvae that disperse farthest are those with lowest weights. The majority of individuals reached the depth of burying for pupation between 7 and 18 cm. The study of this process of dispersion can be utilized in the estimation of postmortem interval (PMI) for human corpses in medico-criminal investigations.

Bilateral symmetry of radial pulse in high-level tennis players: implications for the validity of central aortic pulse wave analysis.

BACKGROUND: Reconstruction of the central aortic pressure wave from the noninvasive recording of the radial pulse with applanation tonometry has become a standard tool in the field of hypertension. It is not presently known whether recording the radial pulse on the dominant or the nondominant side has any effect on such reconstruction. METHOD: We carried out radial applanation tonometry on both forearms in young, healthy, male volunteers, who were either sedentary (n = 11) or high-level tennis players (n = 10). The purpose of including tennis players was to investigate individuals with extreme asymmetry between the dominant and nondominant upper limb. RESULTS: In the sedentary individuals, forearm circumference and handgrip strength were slightly larger on the dominant (mean +/- SD respectively 27.9 +/- 1.5 cm and 53.8 +/- 10 kg) than on nondominant side (27.3 +/- 1.6 cm, P < 0.001 vs. dominant, and 52.1 +/- 11 kg, P = NS). In the tennis players, differences between sides were more conspicuous (forearm circumference: dominant 28.0 +/- 1.7 cm nondominant 26.4 +/- 1.5 cm, P < 0.001; handgrip strength 61.4 +/- 10.8 vs. 53.4 +/- 9.7 kg, P < 0.001). We found that in both sedentary individuals and tennis players, the radial pulse had identical shape on both sides and, consequently, the reconstructed central aortic pressure waveforms, as well as derived indices of central pulsatility, were not dependent on the side where applanation tonometry was carried out. CONCLUSION: Evidence from individuals with maximal asymmetry of dominant vs. nondominant upper limb indicates that laterality of measurement is not a methodological issue for central pulse wave analysis carried out with radial applanation tonometry.

Weighted norm inequalities for Fourier transforms of radial functions

"Vegeu el resum a l'inici del document del fitxer adjunt."

INTERCELLULAR AND SYSTEM-LEVEL ASPECTS OF THE METABOLIC INTERACTIONS BETWEEN NEURONS AND GLIA

Quand on parle de l'acide lactique (aussi connu sous le nom de lactate) une des premières choses qui vient à l'esprit, c'est son implication en cas d'intense activité musculaire. Sa production pendant une activité physique prolongée est associée avec la sensation de fatigue. Il n'est donc pas étonnant que cette molécule ait été longtemps considérée comme un résidu du métabolisme, possiblement toxique et donc à éliminer. En fait, il a été découvert que le lactate joue un rôle prépondérant dans le métabolisme grâce à son fort potentiel énergétique. Le cerveau, en particulier les neurones qui le composent, est un organe très gourmand en énergie. Récemment, il a été démontré que les astrocytes, cellules du cerveau faisant partie de la famille des cellules gliales, utilisent le glucose pour produire du lactate comme source d'énergie et le distribue aux neurones de manière adaptée à leur activité. Cette découverte a renouvelé l'intérêt scientifique pour le lactate. Aujourd'hui, plusieurs études ont démontré l'implication du lactate dans d'autres fonctions de la physiologie cérébrale. Dans le cadre de notre étude, nous nous sommes intéressés au rapport entre neurones et astrocytes avec une attention particulière pour le rôle du lactate. Nous avons découvert que le lactate possède la capacité de modifier la communication entre les neurones. Nous avons aussi décrypté le mécanisme grâce auquel le lactate agit, qui est basé sur un récepteur présent à la surface des neurones. Cette étude montre une fonction jusque-là insoupçonnée du lactate qui a un fort impact sur la compréhension de la relation entre neurones et astrocytes. - Relatively to its volume, the brain uses a large amount of glucose as energy source. Furthermore, a tight link exists between the level of synaptic activity and the consumption of energy equivalents. Astrocytes have been shown to play a central role in the regulation of this so-called neurometabolic coupling. They are thought to deliver the metabolic substrate lactate to neurons in register to glutamatergic activity. The astrocytic uptake of glutamate, released in the synaptic cleft, is the trigger signal that activates an intracellular cascade of events that leads to the production and release of lactate from astrocytes. The main goal of this thesis work was to obtain detailed information on the metabolic and functional interplay between neurons and astrocytes, in particular on the influence of lactate besides its metabolic effects. To gain access to both spatial and temporal aspects of these dynamic interactions, we used optical microscopy associated with specific fluorescent indicators, as well as electrophysiology. In the first part of this thesis, we show that lactate decreases spontaneous neuronal, activity in a concentration-dependent manner and independently of its metabolism. We further identified a receptor-mediated pathway underlying this modulatory action of lactate. This finding constituted a novel mechanism for the modulation of neuronal transmission by lactate. In the second part, we have undergone a characterization of a new pharmacological tool, a high affinity glutamate transporter inhibitor. The finality of this study was to investigate the detailed pharmacological properties of the compound to optimize its use as a suppressor of glutamate signal from neuron to astrocytes. In conclusion, both studies have implications not only for the understanding of the metabolic cooperation between neurons and astrocytes, but also in the context of the glial modulation of neuronal activity. - Par rapport à son volume, le cerveau utilise une quantité massive de glucose comme source d'énergie. De plus, la consommation d'équivalents énergétiques est étroitement liée au niveau d'activité synaptique. Il a été montré que dans ce couplage neurométabolique, un rôle central est joué par les astrocytes. Ces cellules fournissent le lactate, un substrat métabolique, aux neurones de manière adaptée à leur activité glutamatergique. Plus précisément, le glutamate libéré dans la fente synaptique par les neurones, est récupéré par les astrocytes et déclenche ainsi une cascade d'événements intracellulaires qui conduit à la production et libération de lactate. Les travaux de cette thèse ont visé à étudier la relation métabolique et fonctionnelle entre neurones et astrocytes, avec une attention particulière pour des rôles que pourrait avoir le lactate au-delà de sa fonction métabolique. Pour étudier les aspects spatio-temporels de ces interactions dynamiques, nous avons utilisé à la fois la microscopie optique associée à des indicateurs fluorescents spécifiques, ainsi que l'électrophysiologie. Dans la première partie de cette thèse, nous montrons que le lactate diminue l'activité neuronale spontanée de façon concentration-dépendante et indépendamment de son métabolisme. Nous avons identifié l'implication d'un récepteur neuronal au lactate qui sous-tend ce mécanisme de régulation. La découverte de cette signalisation via le lactate constitue un mode d'interaction supplémentaire et nouveau entre neurones et astrocytes. Dans la deuxième partie, nous avons caractérisé un outil pharmacologique, un inhibiteur des transporteurs du glutamate à haute affinité. Le but de cette étude était d'obtenir un agent pharmacologique capable d'interrompre spécifiquement le signal médié par le glutamate entre neurones et astrocytes pouvant permettre de mieux comprendre leur relation. En conclusion, ces études ont une implication non seulement pour la compréhension de la coopération entre neurones et astrocytes mais aussi dans le contexte de la modulation de l'activité neuronale par les cellules gliales.

Major impact of body position on arterial stiffness indices derived from radial applanation tonometry in pregnant and nonpregnant women.

OBJECTIVE: To evaluate the impact of body position on the arterial stiffness indices provided by radial applanation tonometry in pregnant and nonpregnant women. METHODS: Twenty-four young women (18-30 years) in the third trimester of a normal pregnancy and 20 healthy nonpregnant women of the same age were enrolled. In each, applanation tonometry was carried out in the sitting and supine position. The following stiffness indices were analyzed: systolic augmentation index (sAix), sAix adjusted for heart rate (sAix@75) and diastolic augmentation index (dAix), all expressed in % of central aortic pulse pressure. RESULTS: The sAix was apparently not influenced by body position, but the transition from seated to supine was associated with a substantial decrease in heart rate. When correcting for this confounder by calculating the sAix@75, systolic augmentation was substantially lower when individuals were supine (mean ± SD: nonpregnant 3.0 ± 14.4%, pregnant 8.8 ± 9.7%) than when they were sitting (nonpregnant 5.7 ± 13.0%, pregnant 11.1 ± 83%, P = 0.005 supine vs. seated in both study groups, P > 0.2 for pregnant vs. nonpregnant). The influence of body position on the dAix went in the opposite direction (supine: nonpregnant 9.7 ± 6.6%, pregnant 4.4 ± 3.5%; seated: nonpregnant 7.7 ± 5.8%, pregnant 3.3 ± 2.4%, P < 0.00001 supine vs. seated in both study groups, P = 0.001 for pregnant vs. nonpregnant). CONCLUSION: Body position has a major impact on the pattern of central aortic pressure augmentation by reflected waves in healthy young women examined either during third trimester pregnancy or in the nonpregnant state.