Untersuchungen zur Funktion enterischer Gliazellen bei der Vermittlung der angeborenen Immunantwort

Die Gliazellen des enterischen Nervensystems galten lange Zeit lediglich als Packmaterial der Neuronen. Erst in den letzten Jahren rückte dieser Zelltyp in das Interesse der Forschung, weil mehrere Studien eine Schlüsselrolle bei der Erhaltung der Darmwandintegrität postulierten. Da bisher wenig über die immunphysiologischen Eigenschaften der enterischen Gliazellen bekannt war, wurde in dieser Arbeit deren Bedeutung bei der angeborenen intestinalen Immunantwort untersucht. Hierfür wurden Primärkulturen von enterischen Gliazellen eingesetzt, welche aus dem Plexus myentericus adulter Ratten stammten. Es wurde erstmalig nachgewiesen, dass enterische Gliazellen über Toll like und NOD-Rezeptoren (TLR 2, TLR 4, TLR 6, TLR 7, TLR 9, NOD 1, NOD 2) pathogene bakterielle Muster (PAMPs) erkennen. Dabei zeigte sich, dass eine enge Vernetzung zwischen den Toll-like-Rezeptoren besteht. Einerseits findet eine Liganden-spezifische Regulierung der Toll-like-Rezeptoren statt, anderseits beeinflussen TLR spezifische Liganden die mRNA-Expression weiterer Toll-like-Rezeptoren. In der Analyse der intrazellulären Signalweiterleitung konnte die Existenz verschiedener Adaptor- und Interaktionsmoleküle wie RICK und Myd88 sowie der IKK / NF κB Signalweg mit Degradierung von IκB α nach Aktivierung durch LPS belegt werden. Aktivierte enterische Gliazellen sind eine Quelle für pro- und anti-inflammatorische Interleukine (IL-1α, IL 1β, IL 6, IL-10, IL-12), TNF α und Chemokine (Ccl-2, Cxcl-9, Cxcl-10). Sie können somit weitere immunkompetente Zellen rekrutieren und agieren vermutlich als Schnittstelle zwischen der angeborenen und erworbenen Immunantwort. Die Ergebnisse dieser Arbeit implizieren, dass es sich bei enterischen Gliazellen um einen zusätzlichen immunregulatorischen Zelltyp im Darm handelt, welcher aktiv bei der angeborenen Immunabwehr mitwirkt. Neben pro inflammatorischen Eigenschaften tragen enterische Gliazellen auch zur Darmprotektion während Entzündungsprozessen bei. Daraus ergibt sich eine komplexe Funktionalität der enterischen Gliazellen bei der immunologischen Homöostase im Darm

On the mechanical quality factors of cryogenic test masses from fused silica and crystalline quartz

Current interferometric gravitational wave detectors (IGWDs) are operated at room temperature with test masses made from fused silica. Fused silica shows very low absorption at the laser wavelength of 1064 nm. It is also well suited to realize low thermal noise floors in the detector signal band since it offers low mechanical loss, i. e. high quality factors (Q factors) at room temperature. However, for a further reduction of thermal noise, cooling the test masses to cryogenic temperatures may prove an interesting technique. Here we compare the results of Q factor measurements at cryogenic temperatures of acoustic eigenmodes of test masses from fused silica and its crystalline counterpart. Our results show that the mechanical loss of fused silica increases with lower temperature and reaches a maximum at 30 K for frequencies of slightly above 10 kHz. The losses of crystalline quartz generally show lower values and even fall below the room temperature values of fused silica below 10 K. Our results show that in comparison to fused silica, crystalline quartz has a considerably narrower and lower dissipation peak on cooling and thus has more promise as a test mass material for IGDWs operated at cryogenic temperatures. The origin of the different Q factor versus temperature behavior of the two materials is discussed.Comment: 11 pages, 2 figures, submitted to Class. Quantum Gra

Kawasaki Disease

Kawasaki disease (KD) is an acute-onset systemic vasculitis of medium-sized vessels that mostly affects infants and toddlers. Globally, it is the most common form of childhood primary vasculitis. Delayed diagnosis and treatment results in coronary artery aneurysms in up to 25% of all affected individuals. Thus, KD is the most common acquired heart disease in developed countries. Here, the current understanding of clinical presentations, pathophysiological concepts, disease-associated complications, and available pharmaceutical treatment is provided and discussed in the context of available literature

Orbital inflammation and colitis in pediatric IgG4-related disease: A case report and review of the literature.

IgG4-related disease (IgG4-RD) is an inflammatory disorder characterized by tumor-like swelling in one or more organs, elevated serum IgG4 levels, and histological alterations with infiltration of IgG4-positive plasma cells. IgG4-RD is rare and likely underdiagnosed in children. We report a case of a 16-year-old girl with IgG4-positive colitis that developed weeks after IgG4-related ophthalmic disease and discuss diagnosis and treatment in the context of the literature available. Since the pathophysiology of IgG4-RD is unknown, treatment options are empiric and, for the most part, untargeted. Systemic corticosteroid treatment is the basis of anti-inflammatory treatment in IgG4-RD and induced early remission in our patient. During corticosteroid taper, the patient developed weight loss and intestinal inflammation. Histopathological assessment of the intestinal walls confirmed IgG4-positive colitis. Immune-modulating treatment with non-biologic (e.g., methotrexate (MTX) and mycophenolate mofetil) or biologic (rituximab) disease-modifying antirheumatic drugs has been reported in treatment refractory or corticosteroid-dependent patients. The patient responded to treatment with anti-inflammatory therapy with food rich in TGF-β2 (modulen) and MTX. This is one of the first pediatric patients reported with IgG4-related colitis extending the phenotype of pediatric IgG4-RD. International collaboration to prospectively document clinical presentation and treatment responses may help to further establish the phenotype and treatment options and to raise awareness for IgG4-RD

Neighbourhood species richness and drought-tolerance traits modulate tree growth and δ13C responses to drought

Mixed-species forests are promoted as a forest management strategy for climate change mitigation and adaptation because they are more productive and can be more resistant and resilient than monospecific forests under drought stress. However, the trait-based mechanisms driving these properties remain elusive, making it difficult to predict which functional identities of species best improve tree growth and decrease tree physiological water stress under drought. We investigated tree growth and physiological stress responses (i.e. increase in wood carbon isotopic ratio; δ13C) to changes in climate-induced water availability (wet-to-dry years) along gradients in neighbourhood tree species richness and drought-tolerance traits. Using tree cores from a large-scale biodiversity experiment, we tested the overarching hypothesis that neighbourhood species richness increases growth and decreases δ13C. We further hypothesized that the abiotic (i.e. climatic conditions) and the biotic context modulate these biodiversity-ecosystem functioning relationships. We characterized the biotic context using drought-tolerance traits of focal trees and their neighbours. These traits are related to cavitation resistance vs. resource acquisition and stomatal control. We found that tree growth increased with neighbourhood species richness. However, we did not observe a universal relief of water stress in species-rich neighbourhoods, nor an increase in the strength of the relationship between richness and growth and between richness and δ13C from wet-to-dry years. Instead, these relationships depended on both the traits of the focal trees and their neighbours. At either end of each drought-tolerance gradient, species responded in opposing directions during drought and non-drought years. Synthesis. We report that the biotic context can determine the strength and nature of biodiversity-ecosystem functioning relationships in experimental tree communities. We derive two key conclusions: (1) drought-tolerance traits of focal trees and their neighbours can explain divergent tree responses to drought and diversity, and (2) contrasting, trait-driven responses of tree species to wet vs dry climatic conditions can promote forest community stability. Mixing tree species with a range of drought-tolerance traits may therefore increase forest productivity and stability

Cross-Sectional Associations between Homoarginine, Intermediate Phenotypes, and Atrial Fibrillation in the CommunityThe Gutenberg Health Study

Homoarginine has come into the focus of interest as a biomarker for cardiovascular disease. Atrial fibrillation (AF) causes a substantial increase in morbidity and mortality. Whether circulating homoarginine is associated with occurrence or persistence of AF and may serve as a new predictive biomarker remains unknown. We measured plasma levels of homoarginine in the population-based Gutenberg health study (3761 patients included, of them 51.7% males), mean age 55.6 +/- 10.9 years-old. Associations between homoarginine and intermediate electrocardiographic and echocardiographic phenotypes and manifest AF were examined. Patients with AF (124 patients, of them 73.4% males) had a mean age 64.8 +/- 8.6 years-old compared to a mean age of 55.3 +/- 10.9 in the population without AF (p-value < 0.001) and showed a less beneficial risk factor profile. The median homoarginine levels in individuals with and without AF were 1.9 mol/L (interquartile range (IQR) 1.5-2.5) and 2.0 mol/L (IQR 1.5-2.5), respectively, p = 0.56. In multivariable-adjusted regression analyses homoarginine was not statistically significantly related to electrocardiographic variables. Among echocardiographic variables beta per standard deviation increase was -0.12 (95% confidence interval (CI) -0.23-(-0.02);p = 0.024) for left atrial area and -0.01 (95% CI -0.02-(-0.003);p = 0.013) for E/A ratio. The odds ratio between homoarginine and AF was 0.91 (95% CI 0.70-1.16;p = 0.45). In our large, population-based cross-sectional study, we did not find statistically significant correlations between lower homoarginine levels and occurrence or persistence of AF or most standard electrocardiographic phenotypes, but some moderate inverse associations with echocardiographic left atrial size and E/A. Homoarginine may not represent a strong biomarker to identify individuals at increased risk for AF. Further investigations will be needed to elucidate the role of homoarginine and cardiac function

The force of the sign. Terrorism as a symbolic phenomenon

Seit der radikalen Änderung der weltpolitischen Lage durch das Selbstmordattentat islamistischer Terroristen auf die Supermacht U.S.A. am 11.9.01 versucht die Weltöffentlichkeit, dem Phänomen des Terrorismus durch die verschiedensten Erklärungsstrategien Herr zu werden. Man führt den Kampf der Kulturen oder Religionen an, verweist auf die Ausbeutung der Peripherie des kapitalistischen Weltsystems durch den Hegemon U.S.A. oder pathologisiert bzw. dämonisiert die Taten der Terroristen. Uns scheinen diese Erklärungsstrategien den Machtkonstellationen der postmodernen Gesellschaften nicht gerecht zu werden, da sie ein zentrales soziales Phänomen der vergangenen Jahrzehnte nicht beachten: das Unbehagen an der pluralistischen Gesellschaft und der konsensuell-repräsentativen Demokratie. Um dieses Unbehagen angemessen beschreiben zu können, wollen wir uns ihm aus einer zeichentheoretischen Perspektive nähern, die soziale Formationen nicht durch (kooperative) Arbeit determiniert sieht, sondern durch die Instanz des Codes. Für Jean Baudrillard ist die Wahl des Ziels der beiden Türme bedeutend, die sich wechselseitig reflektieren und das System nach allen Seiten hin abschließen. Mit ihnen wurde das neuralgische Zentrum des Systems getroffen, das sich auf einem binären Code gründet. Die Twintowers bedeuteten nicht nur das Ende jedweder originalen Referenz, sondern auch den Abschluss des Bezeichneten durch die Wiederholung des Zeichens. Der Code führt eine symbolische Verteilung der gesellschaftlichen Körper durch und zielt auf eine möglichst genaue Übereinstimmung der Gemeinschaft mit sich selbst gemäß eines arithmetischen und geometrischen Kalküls. Die integrative Kraft dieses auf dem Identitätsprinzip basierenden Systems scheint immer häufiger nicht mehr in der Lage zu sein, das negative Potential antagonistischer Strategien binden zu können, die in Form von zivilem Ungehorsam, Politik von Minoritäten oder terroristischen Akten die symbolische Ordnung der westlichen Gesellschaften unterhöhlen. In diesem Tagungsband diskutieren wir das Ausmaß der Krise der konsensuellen Demokratie und ihrer Institutionen. Die Aufsätze behandeln folgende Themen: • Die Krise der pluralistischen Gesellschaft: Wie verständlich ist das kulturelle, politische und religiöse Unbehagen am westlichen Wertekanon? • Die Funktion der Medien in der konsensuellen Demokratie; die gesellschaftliche Wirkung der medialen Reproduktion terroristischer Akte; das Bild des Terrorismus in der Populärkultur • Ästhetischer Terror: Die Vernichtung von Sinn und Bedeutung in der zeitgenössischen Kunst und Kunsttheorie • Die politische Logik des Terrorismus (Ziele, Bedingungen u. Legitimität des Terrorismus in Abgrenzung zu alternativen politischen Ausdrucksformen wie z.B. dem zivilen Ungehorsam; die Bedeutung des terroristischen Opfertodes) • Geschichte des Terrorismus (speziell der Terrorismus der RAF) • Terror als irrationale Gewalt (der ontologische Status des Terrorismus)Since the radical changes in international politics caused by the suicide attacks on the USA by Islamic terrorists on the 11th of September in 2001, the world public tries to grasp the phenomenon of „Terrorism“ through different explanatory strategies. These include referring to the clash of cultures and of religions, to the exploitation of the periphery by the capitalist system incarnated by the USA, or pathologizing as well as demonizing the deeds of the terrorists. All these explanatory attempts do not seem to do justice to the actual constellations of power in postmodern societies, because they do not take a widespread social phenomenon of the past decades in consideration: the discomfort with the pluralistic society and with the concurrent-representative democracy. In order to describe this discomfort adequately we would like to approach the phenomenon from a semiotic perspective which does not consider social formations as determined by cooperative work but rather by the authority of the code. For Jean Baudrillard the target was meaningful since the two towers not only reflect each other but also completely close the system. With them the neuralgic center which is based upon the binary code was severely hit. The twin towers not only meant the end of every original reference but also the completion of the signified by the reduplication of the sign. The code conducts a symbolic distribution of the social bodies and aims at an as accurate as possible identification of the community with itself corresponding to an arithmetic and geometric calculus. The system which is based upon the principle of identity does not seem to have the ability to integrate antagonist energies properly. So these antagonist powers undermine the symbolic order of western societies in terms of civil disobedience, politics of minorities or terroristic acts. In this conference transcript we discuss the degree of crisis of consensual democracy and ist institutions. The essays cover the following topics: • The crisis of the pluralistic society: How comprehensible and justified is the cultural, political, and religious discomfort with western values? • The function of mass media in democratic systems: What is the impact of the reproduction of terrorist acts on society? How does popular culture deal with terrorism? • Aesthetic terror: the destruction of sense and meaning in contemporary arts and art theory • The political logic of terrorism (aims, legitimacy of terrorism as opposed to other forms of opposition like civil disobedience; the meaning of the terrorist self-sacrifice death) • History of terrorism (e.g. The German terrorism of the RAF) • Terrorism as an irrational power (ontological status of terrorism