Sympathetic Activation and Baroreflex Function during Intradialytic Hypertensive Episodes

BACKGROUND: The mechanisms of intradialytic increases in blood pressure are not well defined. The present study was undertaken to assess the role of autonomic nervous system activation during intradialytic hypertensive episodes. METHODOLOGY/PRINCIPAL FINDINGS: Continuous interbeat intervals (IBI) and systolic blood pressure (SBP) were monitored during hemodialysis in 108 chronic patients. Intradialytic hypertensive episodes defined as a period of at least 10 mmHg increase in SBP between the beginning and the end of a dialysis session or hypertension resistant to ultrafiltration occurring during or immediately after the dialysis procedure, were detected in 62 out of 113 hemodialysis sessions. SBP variability, IBI variability and baroreceptor sensitivity (BRS) in the low (LF) and high (HF) frequency ranges were assessed using the complex demodulation technique (CDM). Intradialytic hypertensive episodes were associated with an increased (n = 45) or decreased (n = 17) heart rate. The maximal blood pressure was similar in both groups. In patients with increased heart rate the increase in blood pressure was associated with marked increases in SBP and IBI variability, with suppressed BRS indices and enhanced sympatho-vagal balance. In contrast, in those with decreased heart rate, there were no significant changes in the above parameters. End-of-dialysis blood pressure in all sessions associated with hypertensive episode was significantly higher than in those without such episodes. In logistic regression analysis, predialysis BRS in the low frequency range was found to be the main predictor of intradialytic hypertension. CONCLUSION/SIGNIFICANCE: Our data point to sympathetic overactivity with feed-forward blood pressure enhancement as an important mechanism of intradialytic hypertension in a significant proportion of patients. The triggers of increased sympathetic activity during hemodialysis remain to be determined. Intradialytic hypertensive episodes are associated with higher end-of-dialysis blood pressure, suggesting that intradialytic hypertension may play a role in generation of interdialytic hypertension

Macrophage biology in development, homeostasis and disease

Macrophages the most plastic cells of the hematopoietic system are found in all tissues and exhibit great functional diversity. They have roles in development, homeostasis, tissue repair, and immunity. While anatomically distinct, resident tissue macrophages exhibit different transcriptional profiles, and functional capabilities, they are all required for the maintenance of homeostasis. However, these reparative and homeostatic functions can be subverted by chronic insults, resulting in a causal association of macrophages with disease states. In this review, we discuss how macrophages regulate normal physiology and development and provide several examples of their pathophysiologic roles in disease. We define the “hallmarks” of macrophages performing particular functions, taking into account novel insights into the diversity of their lineages, identity, and regulation. This diversity is essential to understand because macrophages have emerged as important therapeutic targets in many important human diseases

Untersuchungen zum Hybridrasensystem CombiGrass für Abschlagflächen auf Golfanlagen

Heutzutage möchten Golfspieler ihre sportlichen Aktivitäten saison- und witterungsunabhängig durchführen. Dies führt meistens zu einer Übernutzung der Abschlagflächen und schließlich zu einer stark verminderten Rasenqualität. Der damit verbundene, hohe Pflegeaufwand ist nicht unerheblich. Im Rahmen dieser Studie wurde das Hybridrasensystem CombiGrass der Firma Eurogreen auf verschiedenen Abschlagflächen von vier ausgewählten Golfanlagen mit Naturrasen verglichen. Es wurden die Parameter Ebenflächigkeit, Drehwiderstand, Kraftabbau, Energierückgabe, vertikale Deformation und Bodenfeuchtigkeit bestimmt. Außerdem wurde die projektive Bodendeckung der Rasennarbe vor und nach mehreren Golfabschlägen untersucht, um mögliche Unterschiede im Grünanteil zwischen Natur- und Hybridrasen festzustellen. Zusätzlich wurden eine quantitative Golfspielerbefragung und eine qualitative Expertenbefragung der Head-Greenkeeper durchgeführt. Die Messergebnisse der Untersuchungen wurden direkt mit den Ergebnissen beider Befragungen verglichen. Durch die Verwendung von CombiGrass, insbesondere unter feuchten Bedingungen und in schattigen Lagen, konnten Bespielbarkeit und Standfestigkeit sowie das Erscheinungsbild und die Ebenflächigkeit auf Abschlagflächen verbessert werden. Des Weiteren wurde eine Reduzierung von herausgeschlagenen Divots, Rasenkrankheiten und Materialaufwand zur Pflege und Instandhaltung festgestellt.At present, golfers like to follow their sport independently of the season and weather conditions. This usually leads to an overuse of teeing grounds which impairs the turfgrass quality and requires high maintenance. The aim of this study was to test the Hybridgrass-System CombiGrass of Eurogreen in comparison to natural turfgrass on teeing grounds of four different golf courses in Germany. Investigations were performed by comparing the parameters evenness, shear strength, shock absorption, force recuperation, vertical deformation and soil moisture. Wearing and appearance properties were compared by detecting total ground cover using a digital analysis technique. In addition, quantitative and qualitative data from interviews with golfers and a head-greenkeeper expert survey were put into relation with the measured values. The results have shown CombiGrass to be an alternative to natural turf on highly stressed teeing grounds especially under wet and shady conditions. A better stability and playability as well as an improved aspect and evenness on hybrid grass teeing grounds were recorded. Furthermore, a reduction of plant diseases, divot size and material costs for maintenance, were reported.De nos jours les golfeurs désirent pratiquer leur sport sans avoir à tenir compte de la saison ou des intempéries. Cela conduit généralement à une utilisation excessive des aires de départ et réduit considérablement la qualité des gazons. Les coûts d´entretien ne sont pas à négliger. Dans le cadre de cette étude on a comparé différents gazons hybrides CombiGrass d´Eurogreen sur les aires de départ de quatre cours de golf spécialement choisis pour leur gazon naturel. Pour ce faire on a défini préalablement certains paramètres tels les surfaces planes de gazon, la résistance du gazon à s´enrouler, sa biodégradation, sa restitution d´énergie, sa déformation verticale et l´humidité des sols. On a par ailleurs analysé qu´elle serait la couverture herbeuse sur ces aires à l´avenir avant et après plusieurs tees, afin de pouvoir déterminer les différences entre les gazons naturels et les gazons hybrides. On a également interviewé le plus grand nombre possible de golfeurs afin de connaître leur opinion. On a de même fait une enquête auprès des experts et chefsgreenkeepers pour avoir leurs expertises. On a directement comparé les résultats obtenus lors de ces deux enquêtes avec les résultats scientifiques des mesures. On a constaté que l´utilisation des CombiGrass, surtout en case d´humidité ou sur des endroits ombragés, améliore la practibilité des courts de golf ainsi que leur résistance et donne une apparence harmonieuse aux aires de départ. On a en outre observé une dimininution des divots et des maladies fongiques ainsi qu´une réduction des coûts d´entretien et aussi des produits utilisé