Les maladies du système nerveux central (SNC) comme la sclérose en plaques, les accidents vasculaires cérébraux et les maladies neurodégénératives (Alzheimer et Parkinson) entraînent une réponse inflammatoire au niveau cérébrale appelée neuroinflammation. Ce phénomène peut avoir pour conséquence la limitation de la propagation de la maladie mais aussi la réparation et la régénération des tissus touchés. La microglie, principale défense du SNC, passe à un stade activé lors de phénomènes neuroinflammatoires et va libérer de nombreux facteurs neuroprotecteurs mais aussi pro-inflammatoires. Cette dualité d’action va ainsi maintenir un cercle vicieux, pouvant conduire à la mort neuronale. Il serait donc intéressant de comprendre le mécanisme de la neuroinflammation pour diagnostiquer et traiter au mieux les pathologies du SNC. Il existe plusieurs cibles moléculaires, parmi elles se trouvent la CycloOXygénase 2 (COX-2), une enzyme qui permet la formation de prostaglandines à partir de l'acide arachidonique, qui apparaît précocement et est fortement surexprimée en cas de neuroinflammation. Cette enzyme serait donc une cible de choix pour le développement d’outils d’imagerie dans le but de diagnostiquer les pathologies dans lesquelles les processus inflammatoires centraux sont présents et ce afin d’améliorer la prise en charge du patient. La tomographie d’émission de positons (TEP) est une technique d’imagerie fonctionnelle très sensible qui permet de quantifier de manière fine les variations d’activités métaboliques ou moléculaires. Cette technique requiert l’utilisation de radiotraceurs marqués avec un émetteur béta+. / Central nervous system (CNS) disorders as multiple sclerosis, stroke and neurodegenerative diseases (Alzheimer’s and Parkinson’s) lead to inflammatory response in the brain called neuroinflammation. This phenomenon usually should result in limiting the spread of the disease but also repair and regeneration of the affected tissues. Microglia, the main defense of the SNC, which is activated during a neurodegenerative event leading to the production of many factors including neuroprotectors but also pro-inflammatories. This duality of actions will thereby maintain endless vicious circle leading to neuronal death. It would be interesting to understand the neuroinflammation mechanism to better diagnose and treat CNS diseases. There are several molecular targets, among them are the CycloOXygenase 2 (COX-2), an enzyme which allows the formation of prostaglandins from arachidonic acid, which appears early and it is significantly overexpressed in case of neuroinflammation. This enzyme is therefore a good biological target for the development of imaging tools in order to diagnose pathologies in which central inflammatory processes are present in order to improve patient care. Postiron emission tomography (PET) is a very sensitive functional imaging technique that quantifies minute variations in metabolic or molecular activities. This technique requires the use of radiotracers labeled with a beta + emitter.

Made available in DSpace on 2016-08-17T18:39:42Z (GMT). No. of bitstreams: 1 4298.pdf: 15812505 bytes, checksum: 0d001ab7407810f069373f198494cc0f (MD5) Previous issue date: 2011-12-14 / Prostaglandin H synthases (PGHS), or cyclooxygenases (COX), are known to exist in at least two isoforms, COX-1 and COX-2, encoded by different genes. COX s play a central role in the inflammatory cascade by converting arachidonic acid, released from membrane phospholipids, into bioactive prostanoids. Non-steriodal anti-inflammatory drugs (NSAIDs) represent an important therapeutic category related to the reduction of inflammation, pain and fever, however, can cause gastric and kidney failure. Selective inhibition of COX-2 by NSAIDs known as coxibs leads to a significant reduction of these side effects in addition reduce fatal thrombotic events and act in controlling some types of cancer and progression of Alzheimer's disease, when used for a long period. This study, based on molecular docking, describes the search for the most favorable poses in the formation of complexes between COX-2 and resveratrol analogues and 1,2,3-triazole derivatives. The three dimensional structure of the enzyme, 1cx2, was obtained from the Protein Data Bank (PDB). The structures of the ligands were obtained by molecular modeling. The docking calculations were carried out with the program GOLD 4.1.2. Analyses of the docking results show that interactions with residues of the side pocket of COX are important for the stabilization of the complexes, in particular His90, Arg120, Ser353, Tyr355 and Arg513 should be mentioned. The ligands studied locate, preferably, between α-helices 13 and 26 of the isoenzyme, and the interaction with the serine 353 residue seems to be related to the activity presented by ligands with low IC50 values, a characteristics that can be exploited in rational design of new leader molecules or in the optimization of selective ligands that should occupy the side pocket of the cyclooxygenase active site of COX-2. / Prostaglandinas H sintases (PGHS), ou ciclooxigenases (COX), existem em pelo menos duas isoformas, COX-1 e COX-2, codificadas por genes diferentes. A COX desempenha um papel central no processo inflamatório através da conversão do ácido araquidônico, liberado a partir dos fosfolipídios da membrana, em prostanóides bioativos. Anti-inflamatórios não esteroides (AINEs) representam uma importante categoria terapêutica relacionada à redução de inflamação, dor, e febre, no entanto, podem causar insuficiência renal e gástrica. A inibição seletiva da COX-2 pelos AINEs conhecidos como coxibs leva a uma redução significativa desses efeitos colaterais, além de reduzir eventos trombóticos fatais e agir no controle de alguns tipos de câncer e na progressão do mal de Alzheimer, quando utilizados de forma prolongada. Este estudo, baseado em docking molecular, descreve a busca das poses mais favoráveis para a formação dos complexos entre a COX-2 e ligantes análogos do resveratrol e derivados de 1,2,3-triazol. A estrutura tridimensional da enzima 1cx2 foi obtida do Protein Data Bank (PDB). As estruturas dos ligantes foram obtidas por modelagem molecular. Os cálculos de docking foram realizados utilizando o programa GOLD 4.1.2. As análises dos resultados de docking mostram que as interações com os resíduos do bolso lateral presente na COX são importantes para a estabilização dos complexos, especialmente, His90, Arg120, Ser353, Tyr355 e Arg513. Os ligantes estudados se localizam, preferencialmente, entre as α- hélices 13 e 26 da isoenzima, sendo que a interação com o resíduo serina 353 demonstra estar relacionada com a atividade apresentada por ligantes com baixos valores de IC50, característica que pode ser explorada racionalmente no desenho de novas moléculas lideres ou na otimização de ligantes seletivos que ocupem o bolso lateral do sítio ativo ciclooxigenase da COX-2.

Träningsvärk efter fysisk aktivitet är ett välkänt fenomen. Vad som ligger bakomträningsvärkens effekter såsom smärta och nedsatt rörlighet är mindre välkänt. Träningsvärk, eller ”delayed onset muscle soreness” (DOMS), har i forskningenantagits bero på muskelskada och inflammation i skelettmusklerna efter att ovana ellerexcentriska övningar utförts. Försöken att lindra träningsvärkens effekter har varitmånga, t ex genom antiinflammatoriska läkemedel (NSAID). Syftet med dennasystematiska litteraturstudie var att svara på frågeställningen hur ibuprofen påverkarträningsvärk där hypotesen att ibuprofen skulle ha en dämpande effekt på träningsvärkantogs. Nio artiklar granskades för att besvara hypotesen utan att några slutsatser omibuprofens inverkan på träningsvärk kunde dras då resultaten pekade åt olika håll ochinga tendenser kunde observeras. Den slutsats som kunde dras utifrån litteraturstudienvar att ytterligare forskning på området är behövlig. Om studier inte kan visa att NSAIDdämpar träningsvärk så kan det ifrågasättas om inflammation är orsaken tillträningsvärken. Ytterligare studier på området är viktigt då NSAID är vanligtförekommande som smärtlindrande läkemedel samtidigt som det har biverkningar. Det finns också forskning som tyder på att NSAID kan ha negativ inverkan på de positivaeffekter som är av intresse i träningssammanhang.

Mehrere Studien haben gezeigt, daß die Cyclooxygenase-2 (COX-2) eine bedeutende Rolle sowohl bei Entstehung als auch Progression maligner Tumoren spielt. COX-2-Inhibitoren werden bereits in klinischen Studien zur Krebstherapie getestet. COX-2 ist die induzierbare Isoform der Cyclooxygenase - dem Schlüsselenzym der Synthese von Prostaglandinen und anderen Eicosanoiden. Im Tier- und Zellkulturmodell konnten COX-Hemmer anti-Tumor-Effekte hervorrufen. Es ist jedoch unklar, ob diese Effekte durch Hemmung des COX-Enzyms oder durch COX-unabhängige Mechanismen vermittelt werden. Wir untersuchten daher die Auswirkung der COX-Inhibition zum einen durch den selektiven COX-2-Hemmer NS-398 sowie zum anderen durch COX-Isoform-spezifische RNA-Interferenz (RNAi) in zwei humanen Ovarialkarzinomzellinien (OVCAR-3 und SKOV-3). OVCAR-3 zeigte eine konstitutive COX-1-Expression und eine durch IL-1beta induzierbare COX-2-Expression. SKOV-3 war COX-1- und COX-2-negativ. IL-1beta führte bei OVCAR-3 zu einer vermehrten Produktion von Prostaglandin E2 (PGE2), die durch eine gegen die COX-2 gerichtete siRNA gehemmt werden konnte, wohingegen COX-1-siRNA keinen Effekt hatte. Das deutet darauf hin, daß die COX-2 die Hauptquelle von PGE2 in OVCAR-3 ist. 1mikroM NS-398 waren ausreichend, um die PGE2-Produktion und somit auch die COX-2 in OVCAR-3 zu inhibieren. Höhere Konzentrationen NS-398 (>10mikroM) hatten einen antiproliferativen Effekt. Auch in der COX-2-negativen Zellinie SKOV-3 trat diese Wachstumshemmung auf; sie war nicht durch exogene Zufuhr von PGE2 (10mikroM) reversibel. Durchflußzytometrische Zellzyklusanalyse ergab, daß der Wachstumshemmung in beiden Zellinien ein G0/G1-Zellzyklusarrest zugrunde liegt. Dagegen führten weder COX-1- noch COX-2-Ausschaltung durch RNAi zu ähnlichen Auswirkungen auf Proliferation bzw. Zellzyklus. Diese Ergebnisse zeigen, dass ein COX-2-unabhängiger Mechanismus für den durch NS-398 induzierten G0/G1-Arrest verantwortlich ist. / Several studies have provided evidence that the enzyme Cyclooxygenase-2 (COX-2) plays an important role in tumor development and progression. COX-2-inhibitors are already evaluated in clinical trials as cancer therapeutics. COX-2 is the inducible isoform of cyclooxygenase - the rate-limiting enzyme in the synthesis of prostaglandins and other eicosanoids. COX-inhibitors cause antitumor effects in animal models and in cell culture experiments. However, it is not clear, whether these effects are due to inhibition of the COX-enzyme or mediated via a COX-independent mechanism. We therefore investigated the effects of COX inhibition by the selective COX-2-inhibitor NS-398, as well as by COX-isoform specific RNA interference (RNAi) in the human ovarian carcinoma cell lines OVCAR-3 and SKOV-3. OVCAR-3 cells showed a constitutive expression of COX-1, and an inducible COX-2 expression. COX-2 was induced through stimulation with Interleukin-1beta, leading to production of high levels of Prostaglandin E2 (PGE2). SKOV-3 cells were negative for both COX isoforms. Selective COX-2-suppression by RNAi reduced PGE2 production in OVCAR-3, whereas COX-1-siRNA had no effect on PGE2 synthesis. Thus, COX-2 is the main source of PGE2 in OVCAR-3 cells. In these cells, 1microM NS-398 was sufficient to completely inhibit PGE2-synthesis - and thus the activity of the COX-2 enzyme. Increasing amounts of NS-398 (>10microM) had an antiproliferative effect. This growth inhibition was also observed in the COX-negative cell line SKOV-3, it could not be reverted by exogenous addition of PGE2 (10microM). Flowcytometric analysis of the cell cycle revealed that this growth inhibition was based on a G0/G1-cell-cycle-arrest. In contrast, suppression of COX-1 or COX-2 by RNAi had no effect on proliferation or cell cycle progression. These results suggest that a COX-independent mechanism is responsible for the G0/G1-arrest induced by NS-398.

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HINTERGRUND: Gastrointestinale Nebenwirkungen unter NSAR, ASS und Phenprocoumon spielen eine bedeutende Rolle im klinischen Alltag. Im Rahmen der Einführung der COX-2 Inhibitoren sollten relevanten Ursachen für Ulcera und Blutungen im Bereich des oberen Gastrointestinaltraktes dargestellt und die Behandlungsstrategien verschieden ausgerichteter Krankenhäuser im klinischen Alltag verglichen werden. METHODEN: Es wurden stationär gastroduodenoskopierte Patienten einer Rheumaklinik und von Krankenhäusern der Grund- und Regelversorgung unter der Therapie mit NSAR, ASS, Phenprocoumon, Glukokortikoiden und COX-2 Inhibitoren im Rahmen einer offenen, multizentrischen Fallkontrollstudie verglichen. Des Weiteren wurden alle Patienten mit einer oberen gastrointestinalen Blutung oder einem Ulcus im Bereich des oberen Gastrointestinaltraktes in die Studie eingeschlossen. Der Einfluss einer Helicobacter pylori Infektion und einer Magenschutzprophylaxe wurde überprüft. ERGEBNISSE: Die höchsten Ulcusraten traten unter der Kombinationstherapie von NSAR und ASS auf. Patienten mit NSAR oder ASS hatten eine Ulcusrate von 35% bzw. 31%. Die Blutungsrate der Patienten mit ASS lag jedoch um 15% höher. Die COX-2 Inhibitoren zeigten mit einer Ulcusrate von 10% deutlich bessere Ergebnisse. Patienten mit einer Helicobacter pylori Besiedlung hatten eine signifikant erhöhte Ulcusrate (48% zu 34%), zeigten aber keine Unterschiede in der Blutungsrate. Der Anteil der Patienten mit einer Magenschutzprophylaxe betrug nur 17%. Die Blutungsrate der Patienten ohne Magenschutz lag bei 87%. SCHLUSSFOLGERUNGEN: Im klinischen Alltag einer rheumatologischen Fachklinik treten gehäuft Ulcera unter NSAR auf. Unter den COX-2 Inhibitoren zeigte sich eine geringere Ulcusrate. Im Unterschied dazu haben in den Krankenhäusern der Regel -und Grundversorgung die Patienten mit einem Ulcus an erster Stelle eine Therapie mit ASS. Eine konsequent durchgeführte Magenschutzprophylaxe mit Protonenpumpeninhibitoren verhindert das Auftreten von gastrointestinalen Ulcera und Blutungen. / BACKGROUND: Gastrointestinal side effects under NSAR, ASS and Phenprocoumon play an important role in the clinical everyday life. In the context of the introduction of the COX-2 inhibitors relevant causes for ulcera and bleedings within the range of the upper gastrointestinal section should be represented and the treatment strategies of differently aligned hospitals in the clinical everyday life be compared. METHODS: Gastro duodenal syncopated in-patients of a hospital for rheumatic diseases and from state hospitals under the therapy with NSAR, ASS, Phenprocoumon, Glukokortikoiden and COX-2 inhibitors were compared within the context of an open, multi-centric drop control study. All patients with an upper gastrointestinal bleeding or an ulcus were included in the area of the upper gastrointestinal section of the study. The influence of a Helicobacter pylori infection and a stomach protection prophylaxis was examined. RESULTS: The highest ulcus rate arose under the combination therapy of NSAR and ASS. Patients with NSAR or ASS had a ulcus rate of 35% and 31% respectively. The bleeding rate of the patients with ASS was however around 15% higher. The COX-2 inhibitors showed clearly better results with an ulcus rate of 10 percent. Patients with a Helicobacter pylori colonization had a significantly increased ulcus rate (48% to 34%), however they showed no differences in the bleeding rate. The proportion of the patients with a stomach protection prophylaxis amounted to only 17 percent. The bleeding rate of the patients without stomach protection was 87%. CONCLUSIONS: In the clinical everyday life of a rheumatological specialized clinic ulcera under NSAR arise. Under the COX-2 inhibitors a smaller ulcus rate shows itself. In contrast to it, patients with an ulcus receive a therapy with ASS in the state hospitals. A consistently implemented stomach protection prophylaxis with proton pump inhibitors prevented the appearance of gastrointestinal ulcera and bleedings.

Background: In paediatrics, the limited documentation to guide medication, the lack of suitable dosage forms, and the continuous development in childhood present a scenario where safety of medication is a particular challenge. Aim: To explore reported adverse drug reactions (ADRs) and the challenges in prescribing and administering medicines in paediatrics, in order to identify and suggest areas needing international surveillance within medication safety and improvement in the clinical setting. Methods: Four exploratory studies were conducted. Worldwide reporting of suspected ADRs (individual case safety reports, ICSR) with ages 0-17 years were examined overall. Twenty published case reports and ICSRs for adolescents, who developed a rare and incompletely documented ADR (rhabdomyolysis) during antipsychotic medicine use, were analysed in-depth. Prescribed doses of anti-inflammatory medicines were studied in a UK electronic health record database. Transcribed focus group interviews with 20 registered nurses from four paediatric wards in Sweden were analysed for factors that may promote or hinder safe medication practices. Descriptive statistics, multiple regression, and content analyses were used. Results: Although, skin reactions and anti-infective medicines were most frequently reported, and more reported in paediatric patients than in adults, medication errors and adverse reactions related to psychostimulant medicines were reported with increased frequency during 2005 to February 2010. The in-depth case analysis emphasised the need for increased vigilance following changes in patients’ medicine regimens, and indicated that ICSRs could contribute with clinically valuable information. Prescribed dose variations were associated with type of dosage form. Tablets and capsules were prescribed with a higher dose than liquid dosage forms. Six themes emerged from the interviews: preparation and administration was complex; medication errors caused considerable psychological burden; support from nurse colleagues was highly valued; unfamiliar medication was challenging; clear dose instructions were important; nurses handling medications needed to be accorded higher priority. Conclusions: Age-specific screening of ICSRs and the use of ICSRs to enhance knowledge of ADRs and medication errors need to be developed. Access to age-appropriate dosage forms is important when prescribing medicines to children. To improve medication safety practices in paediatric care, interdisciplinary collaborations across hospitals on national or even global levels are needed.

More than half of all cases of breast cancer occur among women without any known risk factors. More research is needed on suspected risk factors in order to refine current breast cancer screening tools. The objectives of this thesis were: to determine the breast cancer risk associated with known risk factors (ethnicity, family history, breast biopsy, age at menarche, age at first birth, alcohol, HRT, and BMI), suspected risk factors (smoking, second-hand smoke exposure, smoked/grilled foods, and NSAID use), and to examine the above associations according to tumour receptor status, histologic grade, and menopausal status, with potential confounders also considered. This thesis project was conducted within the framework of the Molecular Epidemiology of Breast Cancer study, a case-control study of women in Vancouver, BC and Kingston, ON, with 1140 cases and 1169 controls recruited from 2005-2010. Information was collected from a detailed questionnaire. Cases and controls were similar in terms of age at menarche, age at first birth, smoking history, second-hand smoke exposure, lifetime smoked/grilled food consumption, HRT, and BMI. Among cases, there were significantly less Europeans and more Chinese, Japanese, and Filipino subjects compared to controls. Cases were more likely to have a first degree relative with breast cancer, as well as a previous benign breast biopsy. Alcohol consumption and past NSAID usage was higher among controls. The level of education completed was higher among controls. Cases were also more likely to be postmenopausal. Family history was associated with breast cancer risk (OR=1.59, CI=1.30-1.94), as was BMI (OR=1.28, CI=1.05-1.58 for overweight and OR=2.28, CI=1.35-3.86 for obese class II). Second-hand smoke was also found to be associated with breast cancer risk (OR=1.42, CI=1.02-1.97 for individuals with a less than 10 pack-year smoking history). Due to reduced sample size with stratification and marginally significant results, it is not possible to draw definitive conclusions regarding pathology sub-types. In summary, these results provide support for the association between several risk factors and breast cancer risk. More research is needed to ascertain how receptor status, histologic grade, and menopausal status affect these associations. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2011-08-15 19:43:06.689

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Indiana University-Purdue University Indianapolis (IUPUI) / Adult hematopoietic stem cells (HSC) are routinely used to reconstitute hematopoiesis after myeloablation; however, transplantation efficacy and multilineage reconstitution can be limited by inadequate HSC number, or poor homing, engraftment or self-renewal. We have demonstrated that mouse and human HSC express prostaglandin E2 (PGE2) receptors, and that short-term ex vivo exposure of HSC to PGE2 enhances their homing, survival and proliferation, resulting in increased long-term repopulating cell and competitive repopulating unit (CRU) frequency. HSC pulsed with PGE2 are more competitive, as determined by head-to-head comparison in a competitive transplantation model. Enhanced HSC frequency and competitive advantage is stable and maintained upon multiple serial transplantations, with full multi-lineage reconstitution. PGE2 increases HSC CXCR4 mRNA and surface expression and enhances their migration to SDF-1α in vitro and homing to bone marrow in vivo and stimulates HSC entry into and progression through cell cycle. In addition, PGE2 enhances HSC survival, associated with an increase in Survivin mRNA and protein expression and reduction in intracellular active caspase-3. While PGE2 pulse of HSC promotes HSC self-renewal, blockade of PGE2 biosynthesis with non-steroidal anti-inflammatory drugs (NSAIDs) results in expansion of bone marrow hematopoietic progenitor cells (HPC). We co-administered NSAIDs along with the mobilizing agent granulocyte-colony stimulating factor (G-CSF) and evaluations of limiting dilution transplants, assays monitoring neutrophil and platelet recoveries, and secondary transplantations, clearly indicate that NSAIDs facilitate mobilization of a hematopoietic graft with superior functional activity compared to the graft mobilized by G-CSF alone. Enhanced mobilization has also been confirmed in baboons mobilized with G-CSF and a NSAID. Increases in mobilization are the result of a reduction of signaling through the PGE2 receptor EP4, which results in marrow expansion and reduction in the osteoblastic HSC niche. We also identify a new role for cannabinoids, an eicosanoid with opposing functions to PGE2, in hematopoietic mobilization. Additionally, we demonstrate increased survival in lethally irradiated mice treated with PGE2, NSAIDs, or the hypoxia mimetic cobalt chloride. Our results define novel mechanisms of action whereby eicosanoids regulate HSC and HPC function, and characterize novel translational strategies for hematopoietic therapies.