1,007 research outputs found
an experimental study
Titelblatt, Inhaltsverzeichnis
Einleitung, Schrifttum
Material und Methoden
In vivo Ergebnisse
In vitro Ergebnisse
Zusammenfassung der Ergebnisse
Zusammenfassung der Ergebnisse
Diskussion
Zusammenfassung, Summary
AnhangIm Rahmen dieser Tissue Engineering-Studie wurde an autolgen aurikulären
Knorpeltransplantaten von je 3 - zum Teil immunmodulierten Hausschweinen in
2 Versuchstiergruppen die Bildung von neuem Knorpelgewebe und die
entzĂĽndlichen Reaktionen untersucht. Dabei wurden die enzymatisch isolierten
porcinen Ohrchondrozyten amplifiziert und anschlieĂźend in dreidimensionale
Konstrukte ĂĽberfĂĽhrt, die FasergerĂĽste aus Polyglykolid-Polylaktid bzw.
Kieselgel und/oder Fibrinkleber enthielten. Nach einer mehrtägigen
Vorkultivierungsphase wurden die Transplantate den Schweinen subkutan re-
implantiert. Nach 3, 8,16 und 31 Tagen wurden die Konstrukte wieder
explantiert und sowohl makroskopisch als auch mikroskopisch untersucht. Es
zeigte sich bei den immunmodulierten Polyglykolid-Polylaktid-Transplantaten
eine Ausbildung von Kalzifizierungen und metaplastischen Verknöcherungen. In
faserfreien Konstrukten der mit Cortison behandelten Schweine wurden
Chondrozyten nachgewiesen, die jedoch degeneriert waren. Blutuntersuchungen
lieferten keine Hinweise auf unerwĂĽnschte Nebenwirkungen der
Glukokortikoidtherapie. In parallelen in vitro Untersuchungen konnte kein
Vorteil eines Zusatzes von Schweineserum zum Monolayerkulturmedium gegenĂĽber
der Verwendung von FCS gesehen werden. Auch in vitro konnten degenerierte
Knorpelzellen nachgewiesen werden, wobei der Degenerationsgrad mit der
Kultivierungszeit und fortschreitender Proliferation der Zellen abnahm. Um in
der nahen Zukunft dem Patienten mit traumatisch oder kongenital bedingtem
Ohrknorpelverlust ein kosmetisch zufriedenstellendes autologes
Knorpeltransplantat bieten zu können, muss es das Bestreben sein, in
ergänzenden Untersuchungen die Transplantatzusammensetzung und deren
Kultivierungsbedingungen zu optimieren.A tissue engineering study was performed to investigate the growth of new
auricular cartilage tissue and inflammatory reactions in autologous cartilage
grafts obtained from three, partly immmunomodulated domestic pigs each in two
experimental groups. This was done by amplifying the enzymatically isolated
porcine ear chondrocytes and subsequently growing three-dimensional tissue on
a supportive fiber scaffold consisting of polyglycolide/polyactide or silica
gel and/or fibrin glue. Following several days of preculture, the grafts were
subcutaneously reimplanted into the pigs. The newly formed tissue was
explanted after 3, 8, 16, and 31 days for macroscopic and microscopic
examination. The immunomodulated polyglycolide-polyactide grafts showed
development of calcifications and metaplastic ossifications. Fiberless
neotissue grown in the cortisone-treated pigs was found to contain
chondrocytes but these were degenerated. Blood tests revealed no signs of
adverse effects of glucocorticoid therapy. Parallel in vitro experiments
showed no advantage of adding bovine serum to the monolayer culture medium
compared to the addition of fetal calf serum (FCS). Degenerated cartilage
cells were also found in vitro with the degree of degeneration decreasing with
the duration of cultivation and the progression of cell proliferation. Further
studies aiming at providing cosmetically acceptable autologous cartilage
grafts for patients with traumatically or congenitally damaged ear cartilage
in the near future should include supplementary investigations for optimizing
graft composition and the respective culture conditions
“When men lose their animals, women gain power”: Women and Change in East Pokot, Kenya
This thesis analyses the effects of increasing sedentarization among pastoral Pokot in East Pokot, Kenia, on society in general and women specifically and explores how the latter react to the new socio-economic circumstances, and again re-transform a heretofore patriarchal social order. Based on 14 months of fieldwork in the areas of Chemolingot and Kadingding and utilizing both quantitative and qualitative research as well as employing Sherry Ortner’s Theory of Practice, it posits three claims:
First, I argue that the face of sedentarization in East Pokot is female. Women are drivers, shapers and beneficiaries of the transformative processes. They surge towards urban centers to explore new sources of income from cash economy and casual work. And they are the ones who leave behind pastoral life to escape from what they perceive as an curtailment of their socioeconomic self-determination. For them, settled life holds a promise of becoming their family’s breadwinners and gain possessions of their own.
Second, this tendency generates friction. Men who, due to their social roles being fixed in terms of herders and warriors, have a harder time adjusting to the new reality, perceive female breadwinners and their for more equitable relationships as a threat to their status as heads of households. Here, a confrontational trope of “lazy men” and “disrespectful women” enters the picture. This trope is a critique of the cultural narrative of the gendered division of labor. Naturalized gendered tasks are becoming visible through female cash-income activities. These new practices open up the floor for debates on the workload of men and women. Underpinning this confrontation is Christian religion with its focus on monogamous marriage and its mission of empowering women to become educated and, thus, economically independent.
Third, I suggest that the female face of sedentarization is Janus-faced. A woman’s opportunities depend on their education and economic resources as well as social and biographical conditions. In settings where wealth is quantified over livestock, women possess little power. Only when cash and immovable properties come into play can they catch up with men. However, there are also risks, such as pauperization and the dissolution of social networks – as well as the burden of earning the household income and fulfilling all reproductive tasks too. These differences become salient in the institution of marriage. Marriage is an arena of contestation between two ideals – i.e., polygamy, associated with pastoralism, versus monogamy, associated with post-pastoralism – and also between men and women who are bargaining about rights and obligations. Here, the chances of influencing married life hinge on breaking with expectations of what it means to be a Pokot woman and launch new practices
Influence of photobiomodulation with blue light on the metabolism, proliferation and gene expression of human keratinocytes
The skin, which is the largest organ of the human body, serves as a protective barrier between the internal milieu and the environment. It functions as the body’s first line of defense against infection and regulates its temperature and fluid balance.
Keratinocytes are present in all the layers of the epidermis, the outermost layer of the skin, and are essentially connected to the pathophysiology of skin diseases such as psoriasis and atopic dermatitis, and play a crucial role in skin wound healing. Keratinocytes are the first cells to be in contact when exposed with external stimuli and are consequently more amenable to non-invasive treatments such as PBM using blue light. The anti-microbial, anti-inflammatory and anti-proliferative effects of blue light are already used for different medical treatments like psoriasis, neonatal jaundice and back pain. However, little is known about the mechanisms transducing the light induced signals from target molecules over downstream processes and/or gene expression to the biological effects and therefore the aim of this project was to examine the photobiomodulary effect of blue light on the immortalized human keratinocyte cell line HaCaT in detail.
Photobiomodulation using blue light irradiation induces a biphasic dose response curve of metabolism in HaCaT cells with an increase in metabolism and proliferation for low doses and a decrease in metabolism and proliferation for higher doses in vitro. For further tests, 7.5min (10.35J/cm²) respectively 30min (41.4J/cm²) were chosen for subsequent experiments to test the blue light effect after different harvesting times in the proliferative phase respectively the anti-proliferative phase of PBM.
Gene expression evaluation of HaCaT cells after 30min (41.4J/cm²) of blue light irradiation revealed an upregulation of “AHR battery genes” leading to production of phase I and phase II enzymes of xenobiotic metabolism. One important action of this downstream process is to provide a delicate hormesis between promoting and preventing ROM-mediated oxidative stress, which is in agreement with our ROS measurements. H2O2 concentrations are increased 30min after blue light irradiation; however, already 1h after irradiation H2O2 is metabolized by the cells leading to an even lower ROS concentration. Furthermore, steroid hormone biosynthesis is activated as a downstream process of “AHR battery gene” expression already 1h after irradiation triggering anti-inflammatory responses. Additionally, inflammation is also decreased due to oxidative stress inhibited NF-κB signaling pathway and interaction with JunB. DNA replication pathway is downregulated resulting in a decrease in cell proliferation due to primary production of ROS, AHR-induced downregulation of CDKN1B and prolongation of S-phase. However, ROS concentrations are not reaching a damaging level as cell survival pathways are enhanced by crosstalk of AHR-ligand complex with EGFR. Moreover, reduction of TNF-signaling pathway and downregulation of TRADD gene expression, which are relevant for apoptotic signaling, are consistent with FACS analysis as 24h after blue light irradiation cells are not showing any sign of apoptosis. Finally, it can be concluded that gene expression after 30min (41.4J/cm²) of blue light irradiation shows a time course after blue light irradiation, with early response genes and pathways leading to the identification of AHR as a possible target for PBM with blue light via photo-oxidation of tryptophan resulting, when using this described dose, in a cell protective effect with decreased proliferation, production of steroid hormones and prevention of inflammatory responses. Moreover, the anti- proliferative effect can be prolonged by consecutive irradiations each 24h.
Photobiomodulation with 7.5min (10.35J/cm²) blue light induced a proliferation increase in HaCaT cells until at least up to 24h after irradiation, which was documented in gene expression analysis with upregulation of DNA replication pathway and genes connected to cell cycle. H2O2 concentrations were increased 30min after blue light irradiation to an even higher level than after a 30min (41.4J/cm2) blue light irradiation; however, already 1h after irradiation H2O2 was metabolized by the cells. The hypothesis was set that even though H2O2 concentrations were higher after a 7.5min (10.35J/cm²) blue light irradiation compared to 30min (41.4J/cm2) the actual oxidative stress was lower. This was explained with the triphasic ROS production-curve induced by PBM described by Huang et al. 2011 and could be linked to gene expression analysis results, where for example oxidative stress dependent Nrf2 transcribed genes were not deregulated. It was not only shown that ROS production was not damaging the cells but even that cell survival pathways were enhanced by crosstalk of EGFR with the AHR-ligand complex. Furthermore, apoptotic signaling was downregulated as TRADD gene expression and TNF-signaling pathway were reduced. Comparable with 30min (41.4J/cm²) blue light irradiation, gene expression analysis revealed an upregulation of “AHR battery genes” after 7.5min (10.35J/cm²) blue light leading to production of phase I and phase II enzymes of xenobiotic metabolism and steroid hormone biosynthesis as a downstream process of “AHR battery gene” expression. However, deregulation of genes and pathways occurred to a smaller extent. Finally, it can be concluded that PBM with blue light, when using 7.5min (10.35J/cm²), activates AHR and results in a cell protective effect with increased proliferation, production of steroid hormones and induction of cell survival pathways. Furthermore, it is suggested not to use consecutive irradiations each 24h if a proliferative effect is desired
Social Diffusion of Religious Values within Families: Conceptual and Methodological Considerations
Familienmitglieder repräsentieren füreinander jeweils gegenseitig den sozialen Kontext, innerhalb dessen sich familiales Handeln und individuelle Persönlichkeitsentwicklung abspielen. Soziale Einflüsse in Familien äußern sich empirisch in einer überzufälligen Ähnlichkeit der Familienmitglieder hinsichtlich einer großen Bandbreite von Merkmalen. Der vorliegende Beitrag fokussiert auf die intrafamiliale Homogenisierung hinsichtlich Religiosität, wobei in einem empirischen Datenbeispiel horizontale Paar-Angleichungsprozesse sowie vertikale intergenerationale Transmissionsprozesse untersucht werden. Neben dem Befund, dass Sozialisationserfahrungen im Elternhaus bedeutsamer sind als spätere Partnereinflüsse, zeigen die Analysen, dass soziale Kontexteffekte umso stärker ausfallen, je größer die Kohäsion in der jeweiligen Interaktionsdyade ist; hier operationalisiert über die Beziehungsqualität.Family members create for each other the social context in which family behavior and personality development take place. The importance of social influence in families is evidenced empirically by family members' great similarity on a wide variety of characteristics. Focusing on intrafamily convergence on religiosity, the study discuses empirical methods of dyadic analysis and illustrates their use with an analysis of horizontal intracouple alignment and vertical intergenerational transmission. In addition to the finding that experiences during religious socialization in the parental home have a stronger impact than partner influences in adulthood, the analyses show that social context effects are stronger when the interaction dyad is more cohesive, as measured by, for example, relationship quality
[Rezension von] Albrecht Dröse: Die Poetik des Widerstreits. Konflikt und Transformation der Diskurse im ›Ackermann‹ des Johannes von Tepl. Heidelberg;Winter, 2013. (Studien zur historischen Poetik 10)
[Rezension von] Albrecht Dröse: Die Poetik des Widerstreits. Konflikt und Transformation der Diskurse im ›Ackermann‹ des Johannes von Tepl. Heidelberg;Winter, 2013. (Studien zur historischen Poetik 10)
[Rezension von] Martin Schuhmann: Reden und Erzählen. Figurenrede in Wolframs ›Parzival‹ und ›Titurel‹
Remetaphorisierendes Wiedererzählen. Die Pfingstszene in der ›Erlösung‹ und in Heinrichs von Neustadt ›Von Gottes Zukunft‹
Es wird argumentiert, dass die Erzählpoetik deutscher Bibelepen des Mittelalters von einem spezifischen Typ des Wiedererzählens geprägt ist, den man als ›remetaphorisierendes Wiedererzählen‹ beschreiben kann. Bibelepisches Wiedererzählen bewegt sich in einem vierpoligen Spannungsfeld, das von den beiden eher stabilen Größen materia und (kognitiver Leit-)Metapher sowie den beiden eher variablen Größen artificium und Sinn konstituiert wird. Am Beispiel der Wiedererzählungen des lukanischen Pfingstereignisses in der ›Erlösung‹ und in Heinrichs von Neustadt ›Von Gottes Zukunft‹ wird gezeigt, wie intensiv sich die Dichter mit den biblischen Metaphern auseinandersetzen und welch erstaunliche semantische, ästhetische und performative Effekte sie remetaphorisierend hervorbringen
"Not ist hierarchisch, Smog ist demokratisch" oder "Umweltbelastungen sind sozial ungleich verteilt"? Eine nähere Beleuchtung der gegenläufigen Positionen von Ulrich Beck und des Environmental Justice-Konzeptes
"Ein Kern der Diskussion über die Risikogesellschaft ist, dass sich die soziale Verteilung der heutigen Umweltrisiken wesentlich von der Verteilung von Reichtümern unterscheide, da von Umweltbelastungen 'alle gleichermaßen betroffen' seien. Kontrovers dazu wird in der Debatte über 'Environmental Justice' (E.J.) die sozial ungleiche Verteilung von Umweltschadstoffen in den Bezug zu vertikaler sozialer Ungleichheit gestellt. Wie kann es sein, dass das Thema 'Umwelt/ Umweltbelastungen' so verschieden betrachtet wird? In diesem Vortrag soll die These des E.J.-Ansatzes, dass es viele gesellschaftlich produzierte Umweltbelastungen gibt, die sozial ungleich verteilt sind, näher beleuchtet werden. Es werden die wichtigsten inhaltlichen Komponenten der E.J.-Forschung herausgefiltert, welche die Argumentation um die Thesen von Ulrich Beck erhellen können. Die Hauptintention ist es, einen Beitrag zur Klärungdes Zusammenhangs von umweltbezogener Ungleichheit mit sozialer Ungleichheit zu leisten und eine Hilfe zu einer systematischen Betrachtung zu geben. Dazu werden folgende Punkte angesprochen: Welche Umweltrisiken werden jeweils (bei U.Beck und in der E.J.-Forschung) berücksichtigt? Können diese, z.B. durch die Beachtung ihrer spezifischen räumlichen und zeitlichen Verteilungsmuster, differenziert und unterschieden werden? Gibt es Kriterien - wie z.B. sozial unterschiedliche Möglichkeiten des Folge-Umgangs und der Kompensation - die die Folgen der Schadstoffexposition weiter verstärken? (Viele) Umweltrisiken relativieren somit eben nicht die vertikale soziale Ungleichheit, sondern verstärken diese noch: letztendlich kommt 'zur Not auch noch der Smog' hinzu. Somit können auch Umweltrisiken eine grundsätzliche Dimension der vertikalen sozialen Ungleichheit darstellen. Dies gilt nicht nur für das Ursprungsland der E.J.-Diskussion, die USA, sondern auch z.B. für die BRD, trotz der sozioökonomischen Unterschiede und der Unterschiede in den Umweltbedingungen." (Autorenreferat
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