Thèses sur le sujet « HCMEC »

Les principaux transporteurs ABC et cytochromes P450 exprimés au niveau des microvaisseaux cérébraux chez l’homme sont l’ABCB1/P-gp, l’ABCG2/BCRP et le CYP1B1. Au niveau des organes périphériques, la régulation de l’expression de ces trois marqueurs fait intervenir des facteurs de transcription et notamment le récepteur aryl hydrocarbon (AhR). Or les transcrits d’AhR sont très exprimés au niveau des microvaisseaux cérébraux humains. Les travaux de cette thèse ont donc dans un premier temps été consacrés à l’étude de l’implication de la voie du récepteur Ah dans la régulation de l’expression de l’ABCB1, de l’ABCG2 et du CYP1B1 au niveau de la barrière hémato-encéphalique. In vivo, nous avons mis en évidence qu’un traitement aigu par la dioxine (ou TCDD), ligand puissant d’AhR, induisait l’expression génique et protéique du Cyp1b1 au niveau des microvaisseaux cérébraux de rats adultes Srague-Dawley. De même, in vitro, l’exposition au TCDD a fortement induit l’expression du CYP1B1 dans la lignée hCMEC/D3, un modèle in vitro de l’endothélium cérébral humain et le recours à la technique de l’ARN interférence nous a permis de démontrer que le récepteur Ah était impliqué dans les effets observés. En revanche, que ce soit in vivo ou in vitro, l’exposition au TCDD n’a entrainé aucune modification significative de l’expression de l’ABCB1 ou de l’ABCG2. Dans un second temps, nous avons étudié l’interrelation entre la voie AhR et les voies de réponse à l’hypoxie cellulaire. Les différentes expériences réalisées sur la lignée cellulaire hCMEC/D3 ont mis en évidence une interaction non réciproque entre ces deux voies de signalisation : en cas d’activation simultanée, la réponse à l’hypoxie abolit la réponse AhR tandis que l’activation de la voie AhR ne modifie pas la réponse adaptative à l’hypoxie
ABCB1 (P-gp), ABCG2 (BCRP) and CYP1B1 are the main ABC transporters and cytochrome P450 enzymes expressed at the human blood-brain barrier (BBB). In peripheral tissue, expression of these proteins is regulated by transcription factors such as the aryl hydrocarbon receptor (AhR). Interestingly, high levels of AhR mRNA are detected in human brain microvessels. We therefore investigated the potential implication of AhR in the regulation of ABCB1, ABCG2 and CYP1B1 expression. In vivo, a single dose of TCDD, a highly potent AhR ligand, increased Cyp1b1 transcripts and protein expression in rat brain microvessels. Similarly, exposing hCMEC/D3 cells, an in vitro promising model of human BBB, to TCDD induced CYP1B1 expression. Using small interfering RNA, we established AhR involvement in TCDD effects. However, either in vivo or in vitro TCDD treatment had no effect on ABCB1 or ABCG2 expression. Next, we investigated the crosstalk between AhR and hypoxia signalling pathways in case of simultaneous activation. Our experiments revealed that a crosstalk between these two pathways effectively occurred in hCMEC/D3 cells: hypoxia inhibited AhR response but not the reverse

La proteína de adhesión vascular 1 (VAP-1) es una proteína pro-inflamatoria que facilita el reclutamiento leucocitario a través de su actividad amino oxidasa sensible a semicarbazida (SSAO, E.C 1.4.3.21). La SSAO plasmática incrementa en pacientes con infarto cerebral o “stroke” isquémico y hemorrágico, y su actividad predice la aparición de hemorragias después del tratamiento con tPA. Además, la SSAO/VAP-1 se encuentra incrementada en plasma y tejido cerebral de pacientes con enfermedad de Alzheimer (EA). Así pues, creemos que la SSAO/VAP-1 puede contribuir al daño vascular en stroke y EA. Sin embargo, los mecanismos moleculares y su posible contribución al nexo stroke-EA se desconocen. En este trabajo hemos establecido un modelo de isquemia sencillo usando células endoteliales periféricas que expresan la SSAO/VAP-1 humana (HUVEC hSSAO/VAP-1) en condiciones de deprivación de oxígeno y glucosa (OGD). Mediante este modelo encontramos que la expresión de SSAO/VAP-1 incrementa la susceptibilidad de las células endoteliales a la OGD, y la oxidación de sus sustratos aumenta el daño vascular. Las caspasas 3 y 8 se activan durante esta muerte celular. Además, la OGD constituye un estímulo para la liberación de SSAO/VAP-1 soluble. También, una OGD corta induce la unión de leucocitos al endotelio dependiente de SSAO/VAP-1, parcialmente mediada por su actividad enzimática. Para evaluar mejor los efectos beneficiosos de nuevos compuestos inhibidores de la actividad SSAO/VAP-1 en isquemia cerebral generamos una línea celular endotelial cerebral humana que expresa la SSAO/VAP-1 (hCMEC/D3 hSSAO/VAP-1), como modelo de barrera hematoencefálica (BHE), y establecimos también las condiciones óptimas de OGD. Mediante el uso de las células HUVEC y hCMEC/D3 que expresan SSAO/VAP-1 probamos que el DPH-4, un nuevo compuesto multidiana diseñado para la EA, es capaz de proteger ambas células y disminuir la adhesión leucocitaria dependiente de SSAO en OGD con reoxigenación (OGD-Reox). El DPH-4 también fue efectivo contra el daño inducido por OGD-Reox en presencia de beta amiloide, como modelo de patología de EA. Para determinar los mecanismos moleculares subyacentes a los efectos beneficiosos de la simvastatina en el stroke, utilizamos las células hCMEC/D3 que expresan SSAO/VAP-1 en OGD, así como dos modelos animales de oclusión de la arteria cerebral media (MCAO). Los resultados revelaron que la simvastatina impide la liberación de SSAO/VAP-1 soluble al plasma o medio de cultivo, la cual induce la expresión de E-selectina y VCAM-1, y amplifica la inflamación y el daño subsiguiente en el cerebro infartado. Finalmente, se estudió del posible papel de la SSAO/VAP-1 en el nexo existente entre el stroke y la EA con las células hCMEC/D3. Resultados preliminares mostraron que en las células que expresan SSAO/VAP-1, la OGD-Reox induce la expresión de BACE1 y la disminución de LRP-1, y que su sustrato es capaz de incrementar los niveles de APP. Además, el metabolismo de la metilamina por la SSAO/VAP-1 induce una muerte celular adicional cuando se co-trata con Aβ1-40D, en OGD-Reox. De estos resultados concluimos que la expresión de SSAO/VAP-1 en endotelio puede incrementar el daño asociado a la OGD, y que la OGD induce la liberación de SSAO/VAP-1 soluble. También, que la oxidación de su sustrato media parte del daño vascular y que la adhesión leucocitaria dependiente de la SSAO/VAP-1 agrava la progresión de la patología aumentando la inflamación en isquemia. La inhibición de SSAO/VAP-1 por el DPH-4 puede aportar un beneficio terapéutico para el retraso y/o prevención del stroke, así como para su progresión a EA. La modulación de los niveles de SSAO/VAP-1 media parte de los efectos beneficiosos de la simvastatina en isquemia cerebral. Además, la presencia de SSAO/VAP-1 en el endotelio cerebral puede facilitar la generación de β-amiloide, incrementando el riesgo y el empeoramiento neurológico de la EA.
Vascular adhesion protein 1 (VAP-1) is a pro-inflammatory protein that mediates leukocyte recruitment through its semicarbazide-sensitive amine oxidase (SSAO, E.C 1.4.3.21) activity. Plasmatic SSAO increases in ischemic and in hemorrhagic stroke patients, and its activity predicts the appearance of parenchymal hemorrhages after tPA treatment in ischemic stroke patients. Moreover, SSAO/VAP-1 is also increased in AD patients’ plasma and brain tissue. Hence, we believe that SSAO/VAP-1 could contribute to the vascular damage in both stroke and AD. However, the molecular mechanisms of SSAO/VAP-1 in stroke and its possible contribution to the nexus of ischemic stroke and AD have not been studied in detail. In this work, an easy ischemic model was set up by using peripheral endothelial cells expressing the human SSAO/VAP-1 protein (HUVEC hSSAO/VAP-1) under oxygen-glucose deprivation (OGD) conditions. Based on this model, it was found that SSAO/VAP-1 expression increases the susceptibility of endothelial cells to OGD, and that its substrates oxidation through its enzymatic activity increases the vascular cell damage. Caspase-3 and caspase-8 are activated during the death process. In addition, OGD constitutes a stimulus for the soluble SSAO/VAP-1 release, partly mediated by metalloproteinase-2-dependent shedding. Also, short-time OGD induces SSAO/VAP-1-dependent leukocyte binding on endothelial cells, which is partly dependent on its enzymatic activity. In order to better evaluate the beneficial effects of new pharmaceutical compounds by SSAO/VAP-1 activity inhibition under cerebral ischemia conditions, a human brain endothelial cell line expressing the human SSAO/VAP-1 (hCMEC/D3 hSSAO/VAP-1) was further generated as a model of the brain blood barrier (BBB). OGD conditions were established with these cells as well. By using hSSAO/VAP-1 HUVEC and hCMEC/D3 cells, a novel multitarget-directed ligand (MTDL) DPH-4, designed for AD therapy, was proved able to protect both endothelial cells, as well as to decrease the SSAO-dependent leukocyte adhesion under OGD with reoxygenation. DPH-4 was also effective against the damage induced by OGD and reoxygenation in the presence of beta amyloid as a model of AD pathology. With regard to determine the molecular mechanisms underlying the beneficial effect of simvastatin on ischemic stroke, hCMEC/D3 hSSAO/VAP-1 cells subjected to OGD conditions and two middle cerebral arterial occlusion (MCAO) rat models were used. Results revealed that simvastatin could suppress the release of soluble SSAO/VAP-1 into the plasma or cell culture media, which induces the expression of the adhesion molecules E-selectin and VCAM-1, and amplifies the inflammation and the consequent damage in the infarcted brain. At last, hCMEC/D3 hSSAO/VAP-1 cells were used so as to study the possible role of SSAO/VAP-1 in the nexus between ischemic stroke and AD. Preliminary results showed that in SSAO/VAP-1-expressing cells, OGD with reoxygenation induces the expression of BACE1 and decreases the expression of LRP-1, and that the substrate of SSAO/VAP-1 can further up-regulate the levels of APP under OGD with reoxygenation. Furthermore, the metabolism of methylamine by SSAO/VAP-1 activity induces additional cell death when co-treated with Aβ1-40D under OGD with reoxygenation. In summary, these results conclude that the expression of SSAO/VAP-1 in endothelial cells can increase the OGD-associated cell damage. OGD induces soluble SSAO/VAP-1 release. The oxidation of its substrate mediates part of the tissue damage. SSAO/VAP-1 activity-dependent leukocyte binding further exacerbates the disease progression by augmenting inflammation in cerebral ischemia. The inhibition of SSAO/VAP-1 activity by DPH-4 can provide a therapeutic benefit to the delay and/or prevention of ischemic stroke as well as its progression to AD. The modulation of the SSAO/VAP-1 levels mediates part of the beneficial effect of simvastatin on cerebral ischemia. In addition of ischemic condition, the presence of SSAO/VAP-1 in brain endothelium may facilitate the generation of β-amyloid, hence increasing the risk and neurological worsening of AD.

Erkrankungen des Herz-Kreislaufsystems sind die häufigste Todesursache in Deutschland. Eine gestörte Funktion des Gefäßendothels spielt bei der Entstehung von Herz-Kreislauferkrankungen eine Schlüsselrolle. Das Risiko einer kardiovaskulären Erkrankung ist bei Diabetikern stark erhöht. Der Transkriptionsfaktor COUP-TFII spielt eine essentielle Rolle im Glukosemetabolismus. Gleichzeitig ist er für die Differenzierung von Endothelzellen von großer Bedeutung. Für die Differenzierung und Aufrechterhaltung des arteriellen und venösen Phänotyps von Endothelzellen sind dabei maßgeblich der NOTCH-Signalweg und insbesondere die Transkriptionsfaktoren HEY2 (arteriell) und COUP-TFII (venös) verantwortlich. Gesteigerte Glukosespiegel könnten somit Auswirkungen auf die Differenzierung von Endothelzellen haben und damit einen neuen Mechanismus für das erhöhte Risiko von Gefäßerkrankungen bei Diabetikern darstellen. Im Rahmen der Arbeit konnte die exklusive Expression von COUP-TFII im Zellkern von humanen venösen Endothelzellen nachgewiesen werden. Humane arterielle Endothelzellen zeigten keine Expression von COUP-TFII. Außerdem konnte im Rahmen der Arbeit erstmals die spezifische Expression von COUP-TFII in humanen Endothelzellen der Koronararterie nachgewiesen werden. Die Untersuchung der COUP-TFII Promotoraktivität konnte das Expressionsmuster von COUP-TFII bestätigen. Der Promotor zeigte sowohl in den venösen Endothelzellen der humanen Nabelschnur als auch in den humanen Endothelzellen der Koronararterie Aktivität. Die kurzzeitige Stimulation von venösen Endothelzellen mit Glukose führte zu einem starken Anstieg der COUP-TFII Expression. Eine Translokation von COUP-TFII aus dem Zellkern in das Zytoplasma konnte nicht nachgewiesen werden. Die Langzeitstimulation führte interessanterweise zu einer Verminderung der COUP-TFII Expression und zu einer Erhöhung der Expression von E-Selektin. In beiden Fällen zeigte sich keine Beeinträchtigung der Expression durch Insulin. Die durchgeführten Untersuchungen schließen eine Beteiligung des AKT-Signalweges an der Regulation aus. Es zeigte sich jedoch, dass humane venöse Endothelzellen als Insulin-sensitives Gewebe mit funktionsfähigem AKT-Signalweg einzustufen sind. Stimulationsversuche mit L-Glukose zeigten keine Regulation der COUP-TFII Expression. Eine osmotische Wirksamkeit der hohen Glukosekonzentration auf die Expression von COUP-TFII konnte somit ausgeschlossen werden. Die Deletionsanalyse des COUP-TFII Promotors konnte einen Glukose-sensitiven Bereich innerhalb des COUP-TFII Promotors identifizieren. Weiterhin konnte die Repression der Aktivität des COUP-TFII Promotors durch Hypoxie nachgewiesen werden. Eine der wichtigen Aufgaben von Endothelzellen ist die von der endothelialen NO-Synthase (eNOS) katalysierte Bildung von Stickstoffmonoxid (NO). NO hemmt die Expression des Adhäsionsmoleküls E-Selektin. Eine verringerte NO-Produktion hat die Ausbildung einer endothelialen Dysfunktion zur Folge. In dieser Arbeit konnte erstmals eine Erhöhung der eNOS Expression nach Verminderung der Expression von COUP-TFII in humanen venösen Endothelzellen gezeigt werden. Diese könnte die Ursache für die Verminderung der E-Selektin Expression nach Herabregulation von COUP-TFII sein. Durch die Anwendung einer Plattenkegel-Viskometer-Apparatur konnte gezeigt werden, dass die NO-Abgabe entscheidend von den Strömungsbedingungen und Scherkräften abhängig ist. Die Stimulation arterieller Endothelzellen mit laminarer oder oszillatorischer Schubspannung führte zu einer Erhöhung der NO-Abgabe. Turbulente Schubspannung zeigte dagegen keinen Einfluss auf die NO-Abgabe. Durch Überexpression von COUP-TFII in Kombination mit laminarer Schubspannung wurde die NO-Abgabe weiter gesteigert. Die gezeigte direkte Regulation der HEY2 und COUP-TFII Promotoraktivität durch geänderte Strömungsbedingungen spielt in diesem Prozess möglicherweise eine bedeutende Rolle. Die beschriebene Regulation von COUP-TFII durch Glukose in Endothelzellen könnte eine neue Erklärung für die gesteigerte Rate an Gefäßerkrankungen von Typ2-Diabetikern darstellen. Bei der Regulation der endothelialen NO-Synthase und E-Selektin durch COUP-TFII handelt es sich möglicherweise um einen neuen, anti-adhäsiven Feedback-Mechanismus, der zur Verringerung der Leukozyten-Adhäsion an Endothelzellen und damit zur Gefäßprotektion beitragen könnte. Die differentielle Expression der arteriellen Markergene HEY2 und CD44 konnte in humanen venösen und arteriellen Endothelzellen gezeigt werden. Die Untersuchung der Expression von FOXC1 legt nahe, dass es sich bei diesem Transkriptionsfaktor ebenfalls um ein in Endothelzellen arteriovenös differentiell exprimiertes Gen handelt. Die differentielle Exprimierung von HEY2 in Endothelzellen konnte auf transkriptioneller Ebene zusätzlich durch ein HEY2 Promotor Funktionsassay gezeigt werden. Die Überexpression der NOTCH1 intrazellulären Domäne führte zur Induktion der endogenen Expression der NOTCH-Zielgene HEY1 und HEY2 in HEK 293T Zellen. In dem Zelltyp durchgeführte Reportergenassays zeigten ebenfalls eine deutliche Aktivierung des HEY2 Promotors durch die Überexpression der NOTCH1 intrazellulären Domäne. Durch eine Deletionsanalyse konnte der Bereich, der für die Aktivierung verantwortlichen DNA-Sequenz-Motive stark eingegrenzt werden. Weiterhin konnte die Induktion des HEY2 Promotors durch VEGF und seine Repression durch einen γ-Sekretase Inhibitor nachgewiesen werden. Die Überexpression der NOTCH1 intrazellulären Domäne führte zur Verringerung der mRNA- und Protein-Expression von COUP-TFII in HEK 293T Zellen. Dieses Ergebnis konnte zusätzlich durch ein COUP-TFII Promotor Aktivitätsassay nach Überexpression des NOTCH-Zielgens HEY2 gezeigt werden. Die Deletionsanalyse des COUP-TFII Promotors lässt eine direkte Inhibition von COUP-TFII durch HEY2 vermuten. Die Überexpression von COUP-TFII führte zu einer starken Induktion der COUP-TFII mRNA- und Protein-Expression, jedoch weder in HEK 293T Zellen noch in Endothelzellen zu einer Änderung der HEY2 Promotoraktivität. Die Überexpression von FOXC1 und FOXC2 bewirkte eine Inhibition der HEY2 Promotoraktivität in HEK 293T Zellen. Die in der Arbeit gezeigte hohe Expression von FOXC1 in venösen Endothelzellen könnte somit in Kombination mit COUP-TFII für die komplette Repression der Aktivität des HEY2 Promotors in venösen Endothelzellen verantwortlich sein. Die durchgeführte Deletionsanalyse des HEY2 Promotors legt eine direkte Bindung von FOXC1 und FOXC2 an den HEY2 Promotor nahe. Die erzielten Ergebnisse dieser Arbeit sprechen im Kontext mit der Literatur für eine zelltypspezifische Regulierung/Aktivierung des NOTCH-Signalweges und lassen folgendes Modell zur Differenzierung des venösen oder arteriellen endothelialen Phänotyps vermuten: Die Determinierung des Phänotyps wird entschieden durch das Gleichgewicht der Expression der Interaktionspartner des NOTCH-Signalweges. Der VEGF Co-Rezeptor NRP1 und der VEGFR2 sind die entscheidenden Aktivatoren des NOTCH-Signalweges. Die Balance der Bindung des Repressors COUP-TFII an den NRP1 und VEGFR2 Promotor sowie des Aktivatorkomplexes NICD/RBP-JК an den NRP1 Promotor sind damit entscheidend für die Aktivität des NOTCH-Signalweges. NRP1 bindet VEGF und steigert gleichzeitig dessen Bindung an den VEGFR2. Dies führt zur Induktion von DLL4. Die Bindung von DLL4 an die NOTCH1/4 Rezeptoren führt zur Abspaltung der NOTCH intrazellulären Domäne (NICD) des Rezeptors. Die NICD wandert in den Zellkern und aktiviert dort zusammen im Komplex mit dem Transkriptionsfaktor RBP-JК die Gene HEY1, HEY2 und NRP1. Die Transkriptionsfaktoren HEY1 und HEY2 reprimieren über einen Feedback-Mechanismus direkt die Aktivität des COUP-TFII Promotors.

Gegenstand dieser Arbeit war die Synthese von thermisch schaltbaren Kammcopolymeren auf Basis von N-(Isopropylacrylamid) (NiPAAm) und Polyethylenglykolmakromonomeren (PEGMA). Die intensive Charakterisierung der aus diesen Copolymeren hergestellten Schichten und deren Anwendung als Zellkultursubstrate war ein weiteres Forschungsziel dieser Arbeit. Die mit Hilfe der neuartigen Schichten erhaltenen Zellkultursubstrate wurden anhand verschiedener adhärenter Zelllinien erfolgreich getestet. Alle getesten Zelltypen (Mausfibroblasten, humane Endothelzellen der Nabelschnurvene und humane korneale Endothelzellen) proliferierten auf den angebotenen Zellkultursubstraten bei 37°C und konnten durch senken der Temperatur geerntet werden.

Vietnam is a populous nation experiencing rapid social and economic transition. These changes, in combination with the spread of sexually transmitted infections such as HIV/AIDS, are compromising the reproductive health of young Vietnamese. Access to reliable reproductive health information is limited and social taboos prevent young people from talking openly about this topic. A huge number of young people living in Vietnam thus find themselves without access to relevant, accurate, non-threatening and unbiased information about sexuality and sexual health. The research outlined in this thesis approaches the issue of sexual health information provision for young people living in Vietnam from a participatory action research foundation. A key focus is investigation of the ways in which young people living in Vietnam can be included in the development of online sexual health communication tools by, for and about young Vietnamese. As part of this investigation, this thesis describes research conducted with young Vietnamese in Australia and Vietnam to identify and elucidate their reproductive health information needs, as situated within the contemporary Vietnamese socio-cultural context. The research was undertaken in order to determine how an online resource might meet these needs. This exploratory process involved the utilisation of a range of research methods to determine the website's optimal content, style, features and tone in relation to the Vietnamese context and requirements of its target users. It is hoped that the record of discovery resulting from this research journey will contribute to the existing body of knowledge on online health communication and participatory approaches to the development of context-sensitive health and behaviour-change communication.

Der Schlaganfall ist eine Krankheit mit großer Bedeutung, sowohl für die Betroffenen wie auch unter volkswirtschaftlichen Gesichtspunkten. In der Erforschung neuer und besserer Therapiemethoden für den ischämischen Schlaganfall ist ein gutes in-vitro-Modell der Blut-Hirn-Schranke unerlässlich, da ein Teil der Schädigung des ZNS durch einen Zusammenbruch dieser Barriere verursacht wird. Die hCMEC/D3-Zelllinie stellt ein solches Modell dar; mit steigender Dauer der ischämischen Stoffwechsellage zeigt sich eine Erhöhung der LDH-Konzentration als Marker für das Absterben der Zellen sowie ein Rückgang der Zellvitalität. Zudem lässt sich eine Entzündungsreaktion mit Anstieg der Marker TNF-Alpha und VEGF, sowie tendenziell auch von Interleukin 6 und Interleukin 8 beobachten, welche auch auf eine Barriereschwächung hindeutet. Aus vorherigen Versuchen bekannte Tight junctions-Proteine wie Claudin 1 und Occludin waren in D3-Zellen unter ischämischen Bedingungen nicht verändert, Claudin 5 war in der PCR vermindert exprimiert. Die für die Barriereschwächung verantwortlichen Strukturproteine müssen durch weitere Versuche identifiziert werden. Eine mögliche Erhöhung der Expression des Transkriptionsfaktors ZO-1 könnte unter diesen Bedingungen einen Mechanismus der Barriereschwächung darstellen. Die Expression des Glukokortikoidrezeptors war in Monokultur-Versuchen mit D3-Zellen nach Ischämie erniedrigt. Dies stellt eine Gemeinsamkeit mit Versuchen mit Zelllinien tierischen Ursprungs dar; in diesen zeigten die Zellen durch Degradation des Glukokortikoidrezeptors ein fehlendes Ansprechen auf eine Glukokortikoid-Behandlung. In der Cokultur der D3-Zellen mit Gliomzellen der C6-Zelllinie zeigte sich jedoch eine Erhöhung der GR-Expression. Eine Cokultur kann den komplexen Aufbau der Blut-Hirn-Schranke, mit Beteiligung mehrerer Zelltypen, besser darstellen als Versuche mit nur einer Zelllinie. Die Erhöhung der GR-Expression in diesem humanen in-vitro-Modell der Blut-Hirn-Schranke steht im Gegensatz zu den in-vitro-Versuchen mit anderen Zelllinien. Dies könnte eine mögliche Erklärung liefern, warum die Erkenntnisse aus diesen Versuchen bisher nicht zu einer Verbesserung der Evidenz der Glukokortikoid-Therapie beim ischämischen Schlaganfall beigetragen haben. Zudem zeigt die Fluoreszenzfärbung von D3-Zellen, dass diese auch unter Ischämie auf Glukokortikoide reagieren
The hCMEC/D3 cell line as human in-vitro-model of the blood brain barrier in ischemic stroke

碩士
國立臺灣科技大學
電子工程系
88
A self-organizing HCMAC (Hierarchical Cerebellar Model Arithmetic Computer) neural network classifier which contains a self-organizing input space module and hierarchical CMAC neural network is presented in this thesis. The conventional CMAC can be viewed as kind of basis function networks (BFN) and is useful in two aspects: one is its fast learning speed, and the other is it has a good local generalization capability for approximating nonlinear functions. However, the conventional CMAC needs huge memory requirement, and its performance is highly depended on the approach of input space quantization. To solve these problems, we proposed the self-organizing input space module, which uses Shannon entropy measure to determine adaptive resolutions for all input spaces. Moreover, a hierarchical neural network module was also proposed such that the enormous memory size problem in the conventional CMAC while resolving high dimensional problems can be overcame. Experiments confirm that the self-organizing HCMAC indeed achieve high learning speed and lower memory requirement. Besides, we find that the self-organizing HCMAC classifier has good classification ability by comparing with some other kinds of classifiers.

碩士
國立臺中科技大學
資訊工程系碩士班
106
ABSTRACT Deep neural networks require high performance computing and operations.Among them, the machine learning framework TensorFlow is a neural network implementation tool.The calculations expressed using TensorFlow can be flexibly applied to various systems.Paspberry Pi, Android, Windows, iOS, Linux to server,With little or no modification, portability ranges from portable devices to large distributed systems. Even tens of millions of computing devices.The entire system is very flexible,Mainly explore very large deep neural networks,Data flow graph deep learning provides convenience.And assume that many subgraphs contain distributed execution in this dataflow graph,These executions are manually defined through the step call API. CMAC can be regarded as a mapping method. It has the characteristics of basic functional network (BFN) and supervised learning. It has fast learning convergence and approximation effects, and has the characteristics of simple structure and good local generalization effect. However, since the hyper-cubic blocks of CMAC are evenly distributed, the values of the output in each partition are equal, and in order to solve the problem of huge storage in high-dimensional problems, The performance that causes it depends to a large extent on input space quantization. In order to solve the above two problems, the Gaussian function is added to the hypercube block to form the non-fixed variable micro-partition block, and the HCMAC is cited on the high-dimensional classification problem, which has the ability of fast learning and low memory requirements, and the traditional Compared with CMAC, it is a good neural network in solving high-dimensional classification problems. In this paper, the simulation results show that HCMAC applied to Tensorflow has good approximation ability and convergence performance.

Recently, the use of herbal drugs has been increased all over the world due to their therapeutic effects and fewer adverse effects as compared to conventional medicines. However, many herbal drugs and herbal extracts demonstrate low in vivo activity due to their poor solubility, improper molecular size or high metabolism, scarce absorption and bioavailability. Novel drug delivery systems open the door towards the development of enhancing bioavailability of plant-derived molecules. The innovative formulations are reported to have remarkable advantages over conventional formulations of plant actives and extracts which include increase of solubility, bioavailability, protection from toxicity, enhancement of pharmacological activity and intracellular uptake, modification of pharmacokinetics and biodistribution, improved tissue macrophages distribution, sustained delivery and protection from physical and chemical degradation. There are numerous examples of the application of the nano-sized drug delivery systems in this field related to isolated compounds or purified extracts. This research concerns the improvement of the biopharmaceutical properties and the pharmacological potential of plant-derived molecules. After the optimization of analytical methods for qualitative and quantitative characterization of the compounds, this work was focused on the development of different nano-drug delivery systems, such as micro- or nanoemulsions, solid lipid nanoparticles, nanostructured lipid carriers, liposomes, and albumin nanoparticles, for oral and brain delivery of herbal extracts or single molecules. The obtained formulations were physically and chemically characterized by Light Scattering techniques, transmission electron microscopy observations, high performance liquid chromatography, spectrophotometric and calorimetric analyses. All the developed nanocarriers enhanced the solubility of the bioactives when compared with their aqueous suspensions. Chemical and physical stability during storage, in simulated gastrointestinal environment, in the presence of human serum albumin and in rat plasma was tested. The dialysis bag method was employed to evaluate the release of the entrapped molecules in different pH conditions. In vitro permeation, cytotoxicity and uptake studies using different models such as parallel artificial membrane permeability assay (PAMPA), Caco-2 cell line, hCMEC/D3 cells were performed. These in vitro studies could provide useful information about dissolution and permeation/absorption aspects, which further could be correlated to in vivo bioavailability studies. Furthermore, the mucoadhesive properties of chitosan-coated formulations were investigated in vitro, by the turbidimetric method and the evaluation of the -potential and performing ex-vivo experiments using the rabbit nasal mucosa in a Franz-type diffusion apparatus. Besides, to evaluate the ability of the delivery systems to cross the blood-brain barrier and reach brain tissues, in vivo distribution and fate after intravenous administration in healthy rats were studied. Finally, nanostructured lipid carriers designed with silymarin as a payload were studied in a diabetic mouse model as one alternative/complementary remedial in systemic hyperglycemia, hypertriglyceridemia, and neuropathy. Thus, the present research proposed novel and promising strategies based on the development of nano-drug delivery systems to enhance the biopharmaceutical properties of plant active compounds and improve their performance in therapy.

碩士
義守大學
管理學院管理碩博士班
101
The purpose of this subject is to measure the Satisfaction of foreign investment Enterprises in the Investment Customs Branch - in the area of Ho Chi Minh Customs Department. On that basis, a number of measures is recommended to help the Customs to further improve the quality of electronic customs procedure (called e-customs) in order to improve the satisfaction of investment enterprises and promote exportation and importation business of foreign investment enterprises. The recommended research model was built on the basis of the theory of electronic customs procedure, the satisfaction of foreign investment enterprises. Inheritance and selective discovered from studies of SERVQUAL scale by PZB (1988) to establish the four components of the quality of e-customs procedure affecting the satisfaction of foreign invested enterprises with the name call (1) the customs officials, (2) electronic customs declaration system, (3) Customs policies, (4) the competence. A quantitative study with a sample size 200 investment enterprises in Ho Chi Minh Customs Department is carried out to assess the scale and test theoretical models. Cronbach Alpha reliability results and explored factor analysis (EFA) showed that the scale will meet the reliability, value and acceptance. Thus, based on the research findings, policy makers, managers of Customs, Customs Departments of provinces and cities will further understand the level of interest, enterprise satisfaction for e-customs; then apply appropriate changes to boost export and import operations, electronic communications quickly, create facilitation for enterprises and improve their satisfaction and support investment enterprises to thrive the investment process, improve the efficiency of state management of Customs and increase state budget revenues. Results of regression analysis results also four components (customs official, electronic customs declaration system, customs policies and the service ability) scale of quality electronic customs procedures are statistically significant and affects the satisfaction of business investment, proved that the hypothesis of the study is acceptable. Most powerful factor to the satisfaction of the business system investments electronic customs declaration, followed by customs officials, service ability, and the weakest impact factor to its satisfaction now is the customs policies law.

碩士
美和科技大學
經營管理研究所
99
The training quality today has become the most important factor in the competitive market all over the world and for the process of globalization of the world economy. Therefore, quality management is a very important duty to ensure the quality and to improve the training efficiency at colleges and universities, in Vietnam. However, higher education at Vietnam is facing enormous challenges: the government methods to manage colleges and universities change very slowly, can not ensure the required quality of the whole training system, can not promote the creation from a strong team teachers, administrators and students. Renovation the state management of higher education is the first step to improve the quality and comprehensive development of higher education In this study, the author researched overview about quality management system of higher education, the model of quality management in the world being more universities and colleges in Vietnam learn and apply as: Total Quality Management (TQM), International Standard Organization (ISO) and European Foundation For Quality Management (EFQM), etc. Finally, the author studied the factors that affect the quality management system of HCMC College of transport, Vietnam. From the results of research, the author proposes some solutions to improve the of quality management system training at HCMC College of transport, Vietnam.

碩士
國立高雄大學
國際高階經營管理碩士在職專班(IEMBA)
96
The advent of e-learning provides an important learning channel by which people in Vietnam can learn things. However, less attention has paid to the e-learning acceptance for adolescent. By using 182 samples this thesis conducted an empirical examination to survey factors that affect adolescents’ e-learning acceptance. Research results indicated that (1) most adolescents accept e-Learning as their way to learn, (2) social influence is a highly significant factor and age is a significant factor of acceptance, (3) age has a middle negative correlation with adolescents’ perceived usefulness of e-Learning and attitude towards e-Learning. While social influence has a highly correlation to adolescents’ perceived usefulness, perceived easy of use, attitude towards use and intention of usage of e-Learning, and (4) social influence comes from both peers and adults, and peers’ perceived easy of use and adults’ internet usage have strong positive correlation to students’ acceptance. Discussion and implication are also addressed.

碩士
樹德科技大學
金融與風險管理系碩士班
99
The evolution of technologies makes the world move faster than ever; very easily to find another supplier from other countries via the internet. This competition between firms in the same industry is no longer limited to one country. Firms now need to be more efficient, more responsive in dealing with the current business environment. Enterprise Resource Planning (ERP) has been recognized as a solution to enhance business efficiency and firms’ competitiveness. ERP is a complex information system that integrates and manages all the processes of a firm into a software package. It has been widely used in Vietnam in the recent years. However, implementing an ERP system successfully is very difficult and expensive. Various factors have been considered critical to an ERP implementation success. The purpose of this study is to identify critical success factors that have positive impact on an ERP implementation in HCMC – Vietnam. A survey was administered to managers/users who have taking part in ERP implementation in their respective firms. The results of this study should provide a better understanding of critical success factors to Vietnamese firms implementing ERP systems.

碩士
美和科技大學
經營管理研究所
99
Con Son Import Export Joint Stock Company (Cosimex) was founded on January 18th 2008. Previously, it was a state company, established in 1993, named Con Son Import Export Company (Cosimex), and began the process of privatization from 2005. From that time, Cosimex has to rearrange, to plan, to try to survive without any help from the government. From that time, Cosimex has to learn the real lesson about sustainable development; in which, one of the most important key is human resource management. Besides, the domestic economy has to be rearranged quickly to assimilate into worldwide economy. It requires managers and employees to have non-stop renovation, to apply new scientific ways in management, to have proper business strategy, especially in human resource strategy. The right human resource strategy that satisfies and encourages employees will repair the company errors that exist, will turn company challenges into opportunities, will make the company sustainably develop. With knowledge through courses, through the accumulation and research, I would like to do the research about employees satisfaction to Con Son Import Export Joint Stock Company; in order to help all directors and managers can recognize the reality of Cosimex human resource management; then can establish a strategy to improve the human resource management as well as the company competitiveness in the world markets. In this study, I recommend suggestions to apply to my company Personnel-Administrative Department, including: good resolution to internal relationships, implementation a fairness in treatment about discipline and income policies, create an comfortable working environment, set regulations to promote opportunities for employees advancement, including training affairs.

碩士
樹德科技大學
金融與風險管理系碩士班
99
Today is the era of high growth of economy, including society, open markets and the development of economic relations and international trade. This condition is favorable for the production and business activities in general and in particular commercial banks. However, the risks level implicit in the modern economy is tied to the opportunities and challenges that economic integration brings. For Bank operations and activities in the field of currency trading, credit has closely tied with customers and the organic economy through the implementation of business services activities provided by banks such as raising capital, lending, payment services and other activities. The main reason that the risks to banking activities are diverse, and potentially appear associated with each service activities and the impact are varying degrees, including credit risk. If credit risks happen, there should be enormous impacts and influence directly the survival and development of every credit institution. Higher the impact on the entire banking system is found. Because the traditional credit service activities are still and will continue to be major source of incomes for banks So this thesis discusses theoretical basis for credits in the market economy, including concepts, types of credit, factors that cause credit risks. This thesis also studies in depth of credit activities and current procedure of credit risks management at Agribank HCMC Branch. The objective is to help the bank managers and workers aware of credit depth and gain experience to predict what might happen of credit risks on customer transactions, so they can easily recognize the signs of risk which may occur at their work.

碩士
國立高雄第一科技大學
行銷與流通管理所
90
Facing the fast growing use of the World Wide Web, researchers urged the needs of thorough, theoretical, and empirical understanding of consumers’ response toward web advertising. The new characteristics of the hypermedia computer-mediated environments (HCMEs) raise the concern of how well the existing marketing theories and findings can be applied to web advertising. This research examined the impacts of consumer involvement and consequences of human-computer interaction (CHCI) on attitude toward the web ad (Aad). The research findings provide useful insights to both academicians and practitioners. 　　This research adopted Elaboration Likelihood Model, Flow theory, and MacKenzie and Lutz’s 1985 Aad formation model as study paradigms. According to a literature review of advertising and human-computer interaction, this research proposed a hypothesized model its related hypotheses. The model contained two independent constructs (i.e., consumer involvement and CHCI), one dependent construct (i.e., Aad), and one mediating variable (attitude toward web advertising in general). This research used a lab experiment method. The total effective samples were 445 college students. Students first browsed a downloaded web ad by using an instruction booklet, and then they filled out questionnaires. The findings suggested: (1)Product involvement, ad message involvement, and ad execution involvement were positively associated with Aad. (2)CHCI such as playfulness, exploratory behavior, and focus attention were positively associated with Aad. (3)CHCI and Involvement had the interaction effects on Aad. (4)Attitude toward web advertising in general were found the mediating effects on the relationships between involvement and CHCI on Aad.

碩士
樹德科技大學
金融與風險管理系碩士班
100
Thesis is intended to focus on workers who directly create products for businesses to provide benefits to consumers and profits to companies. The author wishes to explore the factors with motivate workers and affect their intention to change their work. Thesis was conducted through two main phases: Quantitative research with a sample of more than 200 workers and quantitative research through a questionnaire with 30 variables observed for the concept of factors of motivation and 4 variables observed for the concept of intention to change the work. The second phase is to conduct factor analysis to explore and test the reliability of this scale with the aid of SPSS 15.0 for window factor analysis. The results are consistent with five drawn factors including: the caring and support from superiors; the job and loyalty to the company; relationships between colleagues, job security and remuneration; balance between work and life. With the appropriate test results of Cronbach''s Alpha for this scale, the author conducted regression models built with these factors. Based on our model, author has concluded the second factor attached to the profession and the companies most powerful intention to change the work by workers. At the same time the author conducted a number of other relevant expertise for the model with the results of testing the model with no sign of the multi-collinearity and heteroscedasticity. The author hopes this study may contribute somewhat to businesses and management for labor. They can know what factors really affect the intention to change the work of workers who are working in companies, which will give them the best management policy.

碩士
國立成功大學
政治經濟研究所
104
Taiwanese business people whose factories were facing difficulties in Taiwan has been gradually moved factories and formed clustering in Ho Chi Minh City, Binh Duong and Dong Nai Provinces in Vietnam. Hence, this research takes Taiwanese furniture manufacture as an example to investigate into what kind of factors induce Taiwanese business people to settle down in these three locations then make cooperation; and what are the state and the types of the industrial clustering in these three locations. The study designs the research structure so called ‘three pyramids and trapezoid model’. The result is found that the Taiwanese furniture factories settled on these three locations because of national resources and the surrounding subcontractors. As under the ‘three pyramids and trapezoid model’ research structure, the Ho Chi Minh City and the Dong Nai Province are formed the type of industrial clustering so called ‘individual solidify’, and the Binh Duong Province formed the type of industrial clustering called ‘policy-factory harmony’ and ‘individual solidify’. The unique of the Ho Chi Minh City is the resources of woods and the value of geographical location, such as near the harbor and near the country of Cambodia; Dong Nai Province is the resources of woods, labors and earlier cheap lands, subcontractor chain and intra-factories’ management. Last the unique of the Binh Duong Province is the complete subcontractor chain, and the flexible implementation of policy by its province’s government. The study suggests Taiwanese furniture factories should use the surrounding subcontractors to enhance the production.