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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

GUANINE NUCLEOTIDE EXCHANGE ACTIVITY OF PHOSPHOLIPASE D2 AND ITS REGULATION

Mahankali, Madhupriya 15 September 2014 (has links)
No description available.
202

Phospholipase D: Key Player in Macrophage-mediated Inflammation and Resolution

Ganesan, Ramya January 2017 (has links)
No description available.
203

THE ROLE OF PANCREATIC PHOSPHOLIPASE A <sub>2</sub> IN DIETARY CHOLESTEROL ABSORPTION

Baque-Richmond, Bonnie L. January 2000 (has links)
No description available.
204

Use of Bioinformatics to Investigate Abiotic Stress in Arabidopsis and to Design Primers for Pathogen Detection

Mane, Shrinivasrao 30 April 2007 (has links)
The focus of the work has been on computational approaches to solving biological problems. First, microarray analysis was used to study the role of PLDα1 in drought stress in Arabidopsis. Second, a tool for designing and in-silico testing of primers for PCR-based pathogen detection will be discussed. Phospholipase D (PLD) has been implicated in a variety of stresses including osmotic stress and wounding. PLDα 1-derived phosphatidic acid interacts with ABI1 phosphatase 2C and promotes abscisic acid signaling. Plants with abrogated PLDα 1 show insensitivity to ABA and impaired stomatal conductance. My goal is to identify PLDα-mediated downstream events in response to progressive drought stress in Arabidopsis. <i>Arabidopsis thaliana</i> (Col-0) and antisense-PLDα 1 (Anti-PLDα) were drought stressed by withholding water. Anti-PLDα experienced severe water stress at the same time period that Col-0 experienced less water stress. Diurnal leaf water potential (LWP) measurements showed that Anti-PLDα had lower LWP than Col-0 under drought stress conditions. qRT-PCR revealed up to 18-fold lower values for PLDα transcripts in stressed Anti-PLDα plants when compared to stressed Col-0. Microarray expression profiles revealed distinct gene expression patterns in Col-0 and Anti-PLDα. ROP8, PLDδ and lipid transfer proteins were among the differentially expressed genes between the two genotypes. Different microarray analyses methods (TM4 and Expresso) were also compared on two different data sets. The results obtained from Expresso analysis were more accurate when compared with quantitative RT-PCR data. Rapid diagnosis of disease-causing agents is extremely important since delayed diagnosis can result in disease spread and delayed prophylaxis. It is even more important in an era where disease-causing agents are used as bioterrorism agents. Rapid advances in sequencing technology have resulted in the sequencing of thousands of microorganisms in recent years. Availability of genomic sequences has made it possible to identify and characterize microorganisms at the molecular level. PCR-based detection is powerful for pathogen diagnostics since it is rapid and sensitive. We have developed a tool, PathPrime, that can design primers, computationally test them against target genes, and potential contaminant sequences, and identify a minimum set of primers that can unambiguously detect a given list of sequences. / Ph. D.
205

Secretory phospholipase A2 as a tumor specific trigger for targeted delivery of a novel class of liposomal prodrug anticancer etherlipids

Gill, Jason H., Bibby, Michael C., Jensen, S.S., Shnyder, Steven 11 1900 (has links)
No / The use of many common clinically relevant chemotherapeutics is often limited due to insufficient delivery to the tumor and dose-limiting systemic toxicities. Therefore, therapeutics that specifically target tumor cells and are nontoxic to normal cells are required. Here, we report the development of a novel class of liposomes composed of lipid prodrugs, which use the increased secretory phospholipase A2 type IIA (sPLA2) activity of the tumor microenvironment as a trigger for the release of anticancer etherlipids (AEL). Treatment of sPLA2-secreting tumor cells in vitro with liposomes consisting of proAELs resulted in growth inhibition comparable with addition of the AELs alone. Using a specific sPLA2 inhibitor, we showed the low cytotoxicity of the nonhydrolyzed proAEL liposomes and have proven the sPLA2 dependency of the activation of proAELs to cytotoxic AELs. In addition, we showed that our proAEL liposomes circumvent the inherent hemolytic toxicities associated with the use of etherlipids, thereby allowing i.v. administration of such therapeutics as nontoxic prodrug liposomes. Furthermore, using a sPLA2-secreting human colon cancer xenograft model, we showed that the proAEL liposomes are capable of inducing a tumor growth delay in vivo. Taken together, these data support the validity of this novel tumor-selective liposomal prodrug delivery strategy. This new approach also provides a promising system for tumor-selective delivery and release of conventional chemotherapeutics encapsulated in the sPLA2-degradable prodrug liposomes.
206

In silico transcriptional regulation and functional analysis of dengue shock syndrome associated SNPs in PLCE1 and MICB genes

Taqi, M.M., Waseem, D., Ismatullah, H., Haider, S.A., Faisal, Muhammad 01 April 2016 (has links)
Yes / Single nucleotide polymorphisms (SNPs) in PLCE1 and MICB genes increase risk for the development of dengue shock syndrome (DSS). We used Bioinformatics tools to predict alterations at the transcriptional and posttranslational levels driven by PLCE1 and MICB SNPs associated with DSS. Functional and phenotypic analysis conducted to determine deleterious SNPs and impact of amino acid substitution on the structure and function of proteins identified rs2274223 (H1619R) as deleterious to protein coding as it induces structural change in the C2 domain of PLCε, with the mutant residue more positively charged than the wild-type residue (RMSD score, 1.75 Å).Moreover, rs2274223 condenses the chromatinrepressing PLCε expression in DSS. Briefly, this study presents the impact of a single nucleotide transition at SNPs associated with DSS on differential protein binding patterns with PLCE1 and MICB genes and on protein structure modification and their possible role in the pathogenesis of DSS.
207

The modulating effects of polyunsaturated fatty acids on membrane composition and phospholipase D in a canine mast cell line as a model for atopic dermatitis

Basiouni, Shereen 08 May 2014 (has links) (PDF)
Polyunsaturated fatty acids (PUFA) have been used with some success in the treatment of canine atopic dermatitis (CAD). Correspondent in vitro studies revealed that PUFA play a crucial role in the exocytosis of mast cells. n3 PUFA such as α-linolenic acid (LNA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), as well as the n6 PUFA linoleic acid (LA) have been shown to arrest the secretion of inflammatory mediators. Contrary, the n-6 PUFA arachidonic acid (AA) has been proven to promote the production of mast cell inflammatory mediators. However, we are still lacking a complete picture of the mode of action. The goal of this work was to further characterize the modulatory effects of PUFA supplementation on the plasma membrane lipid composition of mast cells. Furthermore the consequences of a membrane modulation of mast cells by PUFA on the localization and activity on of the membrane bound enzyme phospholipases D (PLD) were investigated. Canine mastocytoma cells (C2) were supplemented with one of the following PUFA: LNA, EPA, DHA, LA or AA. To investigate the influence of PUFA on the lipid composition of membrane microdomains, lipid rafts were separated from non-raft plasma membranes of mast cells for the first time using a detergent-free isolation technique. Results show that PUFA are significantly increased in rafts as well as in non-rafts microdomains (Publication 1). The incorporation of PUFA into the membrane goes along with an increase of the unsaturation status and the fluidity of the membrane. This rise in membrane fluidity may result in a reorganization of membrane signaling molecules and enzymes such as the PLD. To define the impact of a PUFA supplementation on PLD trafficking, C2 were transfected with green fluorescent protein (GFP) fusion plasmids encoding PLD1 or PLD2. Since the transfection ability of the suspension cell line C2 is limited, a special transfection protocol was established, suitable for non-adherent cell lines. Transfection succeeded using chicken egg white as coating material for the cell culture plates. The transfection efficiency rose to 50% versus 5% in uncoated plates. In addition to the obvious increase in the transfection efficiency, the new technique is simple and economic and might be suitable for a wide range of suspension cell lines (Publication 2). Using this optimized protocol the influence of PUFA on the trafficking of PLD isoforms was studied. LNA, EPA, DHA and LA but not AA prevented the stimulation-induced translocation of PLD1 to the plasma membrane. Since the translocation of PLD1 is important for mast cell exocytosis, LNA, EPA, DHA and LA do have an inhibiting effect on the stimulation-induced release of pro-inflammatory mediators. All PUFA tested boosted the total PLD activity. In order to rule out, which PLD isoform was affected by the PUFA, the mast cells were supplemented with DHA or AA in the presence of specific PLD isoform inhibitors. DHA completely abolished the inhibitiory effect of the PLD1 inhibitor but had no effect on the inhibitory effect of PLD2 inhibitor. On the other hand, AA suppressed the inhibitory effect of both PLD1 and PLD2 inhibitor (Publication 3). Taking together, the studies provide a mechanistic base for the role of PUFA in the exocytosis processes of mast cells. PUFA of the n3 and the n6 families impact the lipid composition of membrane microdomains, which in turn lead to a modulation of the physiochemical properties of the membrane. LNA, EPA, DHA and LA suppress the release of inflammatory mediators through their inhibitory action on the stimulation-induced translocation of the PLD1. Contrariwise, AA permits the stimulation-induced migration of PLD1 to the plasma membrane and increases the activity of both PLD isoforms. Therefore, LNA, EPA, DHA and LA but not AA inhibit the release of mast cell inflammatory mediators upon stimulation. / Mehrfach ungesättigte Fettsäuren (PUFA) können mit einigem Erfolg zur Behandlung der caninen atopischen Dermatitis (CAD) eingesetzt werden. In vitro-Studien zeigten, dass PUFA eine entscheidende Rolle in der Exozytose von Mastzellen spielen. N-3-PUFA wie α-Linolensäure (LNA), Eicosapentaensäure (EPA), Docosahexaensäure (DHA) sowie die n-6-PUFA Linolsäure (LA) können die Sekretion von Entzündungsmediatoren vermindern. Arachidonsäure (AA) als n-6 mehrfach ungesättigte Fettsäure hingegen fördert die Entzündungsmediatoren-Freisetzung aus den Mastzellen. Eine vollständige Aufklärung der Wirkungsweise fehlt aber weiterhin. Das Ziel dieser Arbeit war eine weitergehende Charakterisierung der modulierenden Effekte einer PUFA-Supplementierung auf die Lipidzusammensetzung der Plasmamembran von Mastzellen. Darüber hinaus wurden die Auswirkungen von PUFA auf die Lokalisation und Aktivität des Membran-gebundenen Enzyms Phospholipase D (PLD) untersucht. Canine Mastozytom-Zellen (C2) wurden mit einer der folgenden PUFA kultiviert: LNA, EPA, DHA, LA oder AA. Um den Einfluss von PUFA auf die Lipidzusammensetzung der Membran-Mikrodomänen zu untersuchen, konnten sowohl Lipid Raft als auch Nicht-Raft Plasmamembran-Anteile von Mastzellen zum ersten Mal mittels einer Detergenzien-freien Isolationsmethode getrennt werden. Hervorzuheben ist, dass PUFA signifikant vermehrt in Raft- sowie in Nicht-Raft Membranmikrodomänen eingelagert werden (Publikation 1). Die Integration von PUFA in die Membran geht mit einer Steigerung der Doppelbindungsanzahl und der Fluidität der Membran einher. Diese Erhöhung der Membranfluidität kann zu einer Reorganisation von membranären Signalmolekülen und Enzymen wie der PLD führen. Um die Auswirkungen einer PUFA-Supplementierung auf den intrazellulären Transport der PLD in C2 zu bestimmen, wurden die Zellen mit PLD1- oder PLD2-codierenden grün fluoreszierenden Protein-(GFP-)Fusionsplasmiden transfiziert. Da die Transfektionsfähigkeit der Suspensions-Zelllinie C2 begrenzt ist, wurde ein für nicht-adhärente Zelllinien geeignetes Transfektionsprotokoll etabliert. Mit Hühnereiweiß als Beschichtungsmaterial für die Zellkultur-Platten stieg die Transfektionseffizienz auf 50% im Vergleich zu 5% bei unbeschichteten Platten. Neben der deutlichen Erhöhung der Transfektionseffizienz ist die neu etablierte Technik einfach durchzuführen sowie wirtschaftlich und kann für eine Vielzahl von Suspension-Zelllinien geeignet sein (Publikation 2). Unter Verwendung dieses optimierten Protokolls wurde der Einfluss von PUFA auf die Translokation der PLD-Isoformen untersucht. LNA, EPA, DHA und LA, nicht aber AA verhindern die stimulationsinduzierte Translokation der PLD1 an die Plasmamembran. Die Translokation der PLD1 ist wichtig für die Mastzell-Exozytose. LNA, EPA, DHA und LA haben hier eine hemmende Wirkung auf die stimulationsinduzierte Freisetzung von proinflammatorischen Mediatoren. Alle getesteten PUFA verstärken die Gesamt-PLD-Aktivität. Um zu unterscheiden, welche PLD-Isoform durch PUFA beeinflusst ist, wurden die Mastzellen mit DHA oder AA in Gegenwart von PLD-Isoform-Inhibitoren supplementiert. DHA hebt die inhibitorische Wirkung des PLD1-Inhibitors vollständig auf, zeigte aber keinen Einfluss auf die hemmende Wirkung des PLD2-Inhibitors. Andererseits unterdrückt AA die hemmende Wirkung des PLD1- als auch des PLD2-Inhibitors (Publikation 3). Zusammenfassend bietet die Studie eine mechanistische Basis für die Rolle von PUFA bei Exozytose-Prozessen von Mastzellen. PUFA der n-3- und n-6-Familie beeinflussen die Lipidzusammensetzung von membranären Mikrodomänen, was wiederum zu einer Modulation der physikalisch-chemischen Eigenschaften der Membran führt. LNA, EPA, DHA und LA verhindern die Freisetzung von Entzündungsmediatoren durch ihre hemmende Wirkung auf die stimulationsinduzierte Translokation der PLD1. Umgekehrt erlaubt AA eine stimulationsinduzierte Migration der PLD1 zur Plasmamembran und steigert die Aktivität der beiden Isoformen der PLD. Somit hemmen LNA, EPA, DHA und LA, aber nicht AA die Freisetzung von Mastzell-Entzündungsmediatoren nach Stimulation.
208

Caracterização funcional e estrutural de inibidores de fosfolipases A2 isolados do plasma de serpente Bothrops jararacussu / Functional and structural characterization of phospholipase A2 inhibitors from Bothrops jararacussu snake plasma

Oliveira, Clayton Zambeli 23 April 2009 (has links)
As fosfolipases A2 (PLA2s) de peçonhas de serpentes compreendem um grupo de enzimas de massas moleculares variáveis entre 14.000 e 18.000, e são responsáveis por vários efeitos tóxicos induzidos pela peçonha destes animais, tornando-se necessária a busca por inibidores naturais de PLA2¬s. O presente trabalho propôs a caracterização bioquímica, farmacológica e estrutural de duas proteínas inibitórias isoladas do plasma da serpente Bothrops jararacussu (BjussuMIPs), que neutralizam as atividades enzimáticas, tóxicas e farmacológicas de diferentes PLA2s. Estes inibidores foram isolados por cromatografia de afinidade em miotoxina-Sepharose, demonstrando que ambos são glicoproteínas com massas moleculares de 24.000 (BjussuMIP) e 23.500 (BjussuMIP) para os monômeros e de 120.000 (BjussuMIP) e 160.000 (BjussuMIP) para os oligômeros. O tratamento dos BjussuMIPs com a N-glicosidase F reduziram os seus pesos moleculares para aproximadamente 18.000, mas não afetaram suas atividades inibitórias sobre PLA2s, sugerindo que os carboidratos tem pouco ou nenhum papel na associação dos BjussuMIPs com estas enzimas. A análise do BjussuMIP por dicroísmo circular mostrou 44% de -hélice, 18% de folhas , 10% de voltas e 28% de estruturas aleatórias. O cDNA obtido por PCR a partir do fígado desta serpente revelou 432 pb (BjussuMIP) e 543 pb (BjussuMIP) que codificam para 144 e 181 resíduos de aminoácidos, respectivamente. O alinhamento da sequência de BjussuMIP com a de outros inibidores do tipo , denominados de PLIs, apresentou 73-92% de similaridade e o BjussuMIP mostrou 89-94% com inibidores do tipo PLIs. Os BjussuMIPs demonstraram ser relativamente estável a variações de pH (6-12) e temperatura, entretanto, perderam atividade inibitória quando submetido a altas temperaturas. A caracterização funcional indica que os BjussuMIPs apresentaram propriedades inibitórias sobre diferentes PLA2s isoladas de peçonhas de serpentes dos gêneros Bothrops e Crotalus. Ambos BjussuMIPs revelaram propriedades farmacológicas como a inibição das atividades fosfolipásica, anticoagulante, miotóxica, indução de edema, citotóxica, bactericida e letal. Os resultados obtidos demonstram que o BjussuMIP mostra maior afinidade sobre as PLA2s homólogas Lys49 como BthTX-I e PrTX-I, enquanto que o BjussuMIP apresenta-se mais específico para PLA2s Asp49, sugerindo uma especificidade entre os BjussuMIPs e tipos de PLA2s. Além disso, ambos os inibidores mostraram ser eficazes na suplementação do antiveneno botrópico em diferentes concentrações, resultando no aumento da capacidade do soro em neutralizar toxinas de serpentes. Os aspectos abordados neste trabalho poderão trazer informações complementares sobre possíveis mecanismos de ação, podendo resultar no melhor entendimento dos efeitos inibitórios exercidos pelos BjussuMIPs, assim como auxiliar o tratamento do envenenamento ofídico pela suplementação da soroterapia tradicional. / Phospholipases A2 (PLA2s) from snake venoms comprise a group of enzymes with molecular weights varying from 14,000 to 18,000, and are responsible for several toxic effects induced by the venom of these animals, making important the search for natural inhibitors of PLA2s. The present work proposed the biochemical, pharmacological and structural characterization of two protein inhibitors isolated from the plasma of Bothrops jararacussu snake (BjussuMIPs), which neutralize the enzymatic, toxic and pharmacological activities of different PLA2s. These inhibitors were isolated by an affinity chromatography on myotoxin-Sepharose, showing that both are glycoproteins with molecular weights of 24,000 (BjussuMIP) and 23,500 (BjussuMIP) for the monomers and 120,000 (BjussuMIP) and 160,000 (BjussuMIP) for the oligomers. The treatment of BjussuMIPs with N-glucosidase F reduced their molecular weights to about 18,000, but did not affect their inhibitory activity on PLA2s, suggesting that the carbohydrates have little or no role in the association of these BjussuMIPs with these enzymes. The analysis of BjussuMIP by circular dichroism showed 44% of -helix, 18% of sheets, 10% of turns and 28% of random structures. The cDNA obtained by PCR from the snake liver showed 432 bp for BjussuMIP and 543 bp for BjussuMIP, which encode for 144 and 181 amino acid residues, respectively. The alignment of the sequence of BjussuMIP with those from other -inhibitors (PLIs) showed 73-92% of similarity and 89-94% for the BjussuMIP compared to other PLIs. The BjussuMIPs showed to be relatively stable to changes in pH (6-12) and temperature, however lost of its activity when submitted to high temperatures. The functional characterization indicates that both BjussuMIPs presented inhibitory properties on different snake venom PLA2s from the genera Bothrops and Crotalus. Both BjussuMIPs showed pharmacological properties such as inhibition of phospholipase, anticoagulant, myotoxic, cytotoxic, bactericidal, edema-inducing and lethal activities. The results show that BjussuMIP presents higher affinity to Lys49-PLA2 homologous, such as BthTX-I and PrTX-I, while BjussuMIP is more specific to Asp49-PLA2s, suggesting specificity between BjussuMIPs and types of PLA2s. Moreover, both inhibitors proved effective in the supplementation of Bothrops antivenom at different concentrations, resulting in an increased capacity of serum in neutralizing snake toxins. The issues reported in this work could bring additional information on possible mechanisms of action and may result in better understanding of the inhibitory effects exerted by these BjussuMIPs, as well as assist the treatment of ophidian envenomations by supplementation of the traditional serum therapy.
209

Implication de la phospholipase A2 cytoplamique dans la pathogénèse de la maladie d'Alzheimer / Involvement of cytosolic phospholipase A2 in Alzheimer's disease pathogenesis

Desbene, Cédric 12 November 2012 (has links)
Les oligomères solubles de peptide Bêta-amyloïde (A-bêta) apparaissent comme les acteurs majeurs de la perte synaptique précoce observée au cours de la maladie d'Alzheimer. Notre équipe a précédemment montré que ces oligomères de peptide A-bêta activent la phospholipase A2 cytosolique (cPLA2), qui entraîne la libération d'acide arachidonique à partir des phospholipides membranaires. En utilisant un modèle d'injection intra cérébro ventriculaire unique d'une faible quantité de peptide A-bêta, nous avons pu observer que l'inactivation constitutive du gène de la cPLA2 protége les souris KO contre les perturbations mnésiques et empêche la réduction de l'expression de protéines synaptiques au sein de l'hippocampe, ces deux effets délétères étant constatés chez les animaux wild-type. Par la suite, nous avons montré que l'activation des sphingomyélinases, consécutive à l'exposition aux oligomères A-bêta, est indétectable dans des neurones en culture issus de souris KO. Dans ces mêmes neurones KO, nous avons constaté que la phosphorylation de Akt/PKB n'est pas altérée suite à l'exposition des cellules aux oligomères A-bêta. Enfin, nous avons pu mettre en évidence une diminution de l'expression de la protéine précurseur du peptide A-bêta (protéine APP), tant au niveau d'homogénats hippocampiques que de neurones en cultures, issus de souris KO. Néanmoins, des travaux supplémentaires sont requis pour établir le lien exact entre cette réduction de l'expression d'APP et la résistance aux oligomères A-bêta, tant in vitro qu'in vivo. Toutefois, ces résultats soulignent l'implication de la cPLA2 dans la neuro dégénérescence entrainée par les oligomères A-bêta, et font apparaitre cette enzyme comme une cible thérapeutique potentielle pour le traitement de la maladie d'Alzheimer / Soluble beta-amyloid (A-beta) oligomers putatively play a critical role in the early synapse loss and cognitive impairment observed in Alzheimer's disease. We previously demonstrated that A-beta oligomers activate cytosolic phospholipase A2 (cPLA2) which specifically releases arachidonic acid from membrane phospholipids. By using a single A-beta oligomers intra cerebro ventricular injection, we observed that cPLA2 gene suppression prevents both the alterations of cognitive abilities and the reduction of hippocampal synaptic markers levels which are observed in wild type mice. We further demonstrated that the A-beta oligomers-induced sphingomyelinase activation is suppressed and that the phosphorylation of Akt/PKB is preserved in neuronal cells isolated from KO mice. Interestingly, expression of the A-beta precursor protein (APP) is reduced in hippocampus homogenates and neuronal cells from KO mice, but the relationship with the resistance of these mice to the A-beta oligomers toxicity requires further investigation. These results therefore show that cPLA2 plays a key role in the A-beta oligomers-associated neurodegenerative effects, and as such represents a potential therapeutic target for the treatment of Alzheimer's disease
210

Messung von Phospholipase D Metaboliten bei Notfall- und Intensivpatienten mit akutem Koronarsyndrom unter besonderer Berücksichtigung der Therapie mit GPIIb/IIIa-Antagonisten

Storm, Christian 01 November 2004 (has links)
Im Rahmen dieser Arbeit wurde der Einfluss des GPIIb/IIIa- Antagonisten Tirofiban auf die Vollblut-Konzentration des Phospholipase D Metaboliten Cholin (2- hydroxyethyltrimethylammonium, "whole blood cholin", WBCHO) bei Patienten mit akutem Koronarsyndrom untersucht. Die Phospholipase D hat eine Schlüsselfunktion bei der Destabilisierung atherosklerostischer Plaques, Aktivierung von Thrombozyten und Sekretion von Matrixmetalloproteinasen durch Makrophagen. Als Analyseverfahren für Cholin wurde die Hochleistungsflüssigkeits-Chromatographie (HPLC) in Verbindung mit der Massenspektrometrie (MS) eingesetzt. Die Klassifikation der Patienten erfolgte nach den aktuellen Richtlinien der European Society of Cardiology (ESC) und des American College of Cardiology (ACC) für das akute Koronarsyndrom. Aus einem Kollektiv von 342 Patienten wurden 32 Patienten mit akutem Koronarsyndrom in diese Studie aufgenommen, in zwei Gruppen mit jeweils 16 Patienten mittels matched pairs Technik unterteilt und analysiert. Eine Gruppe erhielt zusätzlich zur Standard- Therapie Tirofiban. Es wurden Blutabnahmen bei Aufnahme, nach 3-6 Stunden und nach 12-24 Stunden gewonnen. Hieraus wurden Troponin I und T, Myoglobin, Kreatinkinase Isoenzym MB, sowie Vollblut-Cholin bestimmt. Es gab einen signifikanten Verlauf der WBCHO- Konzentration (p = 0,006) in der mit Tirofiban behandelten Gruppe im Gegensatz zur Gruppe die nur die Standardtherapie erhielt (p = 0,174). Für den Verlauf der Standardmarker (Myoglobin, Kreatinkinase, Troponin I und T), wurde keine signifikante Beeinflussung durch die Therapie mit Tirofiban nachgewiesen. Im Vergleich zu Troponin I und T, Myoglobin und Kreatinkinase hatte WBCHO das zeitlich früheste Maximum. WBCHO könnte als Markersubstanz der Phospholipase D Aktivität zusätzliche Informationen über die Möglichkeit einer Destabilisierung einer atherosklerotischen Plaque bei Patienten mit akutem Koronarsyndrom geben. Dies könnte in Kombination mit anderen Markern eine verbesserte Risikostratifizierung in der Frühphase des akuten Koronarsyndroms ermöglichen. Zusätzlich scheint ein Monitoring der Tirofiban Therapie durch die WBCHO Konzentration möglich zu sein. / This research work deals with the measurement of the phospholipase D metabolite choline in patients with acute coronary syndrome (ACS) undergoing GPIIb/IIIa antagonist therapy. The influence of GPIIb/IIIa antagonists on concentration levels of the PLD metabolite 2- hydroxyethyltrimethylammonium in blood (whole blood choline, WBCHO) was studied. The activation of phospholipase D (PLD) has a key function in plaque destabilisation, activation of platelets and secretion of matrixmetalloproteinases by macrophages. For the detection of the PLD metabolite WBCHO high pressure liquid chromatography (HPLC) with a mass spectrometer (MS) was used. The classification of patients was performed according to the current guidelines of the European Society of Cardiology (ESC) and the American College of Cardiology (ACC). 32 patients with ACS out of a 342 patient study were included and analysed by matched pairs technique as two groups with 16 patients. One group was treated with Tirofiban (aggrastrat) in addition to standard therapy. Blood samples were taken at admission, after 3-6 hours and after 12-24 hours and in addition to the troponines, myoglobin and creatinkinase Isoenzyme MB, whole blood choline was analyzed. There was a significant (p = 0,006) decrease of WBCHO level in the group treated with Tirofiban in contrast to the reference group with no significant decrease (p = 0,174). The levels of conventional markers as troponin I and T, CK-MB mass and myoglobin had no significant changes in relationship to the Tirofiban therapy. WBCHO had the earliest maximum in contrast to all other markers. We concluded that WBCHO can be used as an additional early risk marker in ACS. Since GPIIb/IIIa- antagonist- therapy may influence WBCHO level, WBCHO has potential to be used for monitoring of therapy.

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