L’objectif de cette thèse était d’améliorer les connaissances fondamentales sur le tissu adipeux, organe qui est au cœur de la pratique des chirurgiens plasticiens. En effet, ce tissu peut être transplanté de façon autologue afin de combler une perte de substance (rôle volumateur des adipocytes) mais également servir à des fins de régénération tissulaire en lien avec les cellules de la fraction vasculaire stromale (FVS) et tout particulièrement des cellules stromales mésenchymateuses (CSM). Ces cellules s’obtiennent après lipoaspiration du tissu par une digestion enzymatique de la graisse obtenue. Il s’avère que les connaissances disponibles sur ces CSM sont essentiellement issues d’études in vitro après une phase de culture cellulaire plus ou moins longue et ainsi les propriétés in vivo sont mal connues. Ce travail a donc consisté à caractériser l’hétérogénéité du compartiment stromal natif du tissu adipeux obtenu après digestion enzymatique. Nous avons isolé deux populations stromales natives distinctes : les ASC (CD34+), en grande majorité, et des cellules péricytaires (CD146+). Ces 2 types cellulaires différaient dans leurs phénotypes, leurs potentiels de clonogénécité et leurs propriétés immunomodulatrices in vitro et in vivo. Nous avons ensuite comparé la digestion enzymatique du tissu aux techniques de digestion mécanique utilisable au sein de nos blocs opératoires. Nous avons démontré que ces nouvelles techniques permettaient bien de produite les cellules de la FVS dont des CSM, cellules particulièrement intéressante pour des gestes de régénération tissulaire. De plus, l’ensemble des techniques de laboratoire acquise au cours de ce travail nous ont permis d’investiguer le rôle des techniques de lipoaspiration utilisé en chirurgie plastique sur le tissu adipeux. Nous avons démontré par cytométrie de flux et par immunofluorescence in situ qu’une partie de la trame microvasculaire était conservée. L’ensemble de ces résultats viennent s’ajouter aux données cliniques démontrant que la lipoaspiration du tissu est un geste permettant d’être plus conservateur pour le tissu et pourrait expliquer des taux de complications moindre après chirurgie de contour de la silhouette. / The aim of this work was to improve the knowledge on adipose tissue, organ that is at the heart of the practice of plastic surgeons. Indeed, this tissue can be transplanted autologously in order to fill a defect (volumizing role of the adipocytes) but also to be used for tissue regeneration in connection with the cells of the stromal vascular fraction (SVF) and especially the mesenchymal stromal cells (MSCs). These cells are obtained after liposuction of the tissue by enzymatic digestion of the extracellular matrix. It turns out that the knowledge available on these CSM is essentially derived from in vitro studies after a cell culture phase and thus the in vivo properties are poorly known. This work consisted in characterizing the heterogeneity of the native stromal compartment of adipose tissue obtained after enzymatic digestion. We isolated two distinct native stromal populations: the ASC (CD34 +), for the most part, and the pericyte cells (CD146 +). These 2 cell types differed in their phenotypes, their clonogenecity potentials and their immunomodulatory properties in vitro and in vivo. We then compared the enzymatic digestion of the tissue with the techniques of mechanical digestion usable within our operating room. We have demonstrated that these new techniques made it possible to produce the cells of the FVS including MSC, cells particularly interesting for regenerative surgery. In addition, all the laboratory techniques acquired during this work allowed us to investigate the role of liposuction techniques used in plastic surgery on adipose tissue. We have demonstrated by flow cytometry and confocal microscopy, that part of the microvasculature framework is conserved after liposuction. All of these results are in addition to clinical data demonstrating that liposuction of the tissue is a gesture to be more conservative for the tissue and could explain lower rates of complications after contour surgery.

Background: As patients with multiple sclerosis (MS) require lifelong treatment, optimization of therapy with respect to efficacy and safety is needed to limit long-term disease progression. Patients with MS also need a range of health-related services. Satisfaction with these as well as treatment is clinically relevant because satisfied patients are more likely to adhere to therapy. The aim of this study was to determine the status of patient satisfaction and of healthcare services in 70 specialized MS centres in Germany. Methods: In 2011, patients with MS responded to a questionnaire, which solicited clinical and demographic information, as well as patients’ perceptions of their overall situation and their satisfaction with treatment. Results: Of 2791 patients surveyed, 81.9% had relapsing-remitting MS with mild disability [mean (standard deviation) Expanded Disability Status Scale score: 2.6 (1.8)]. Disease activity data were collected from 2205 patients, of whom 57.6% had remained relapse-free during the preceding 12 months. However, 38.9% had experienced one or more relapses, most of whom (67.3%) while receiving immunomodulatory treatment. About one-third of the patients indicated that they were more dissatisfied with their overall situation compared with the time before diagnosis. However, many patients (58.3%) were satisfied with their existing medication. Overall, 72.8% of patients would prefer oral to injectable treatments, assuming there was no difference in their efficacy. Conclusions: A substantial proportion of patients experienced breakthrough disease on treatment and may potentially benefit from a change of therapy. Although largely satisfied with treatment, most patients with MS would choose oral over injectable treatments.

L'oligomérisation enzymatique de la rutine et esculine a donné lieu à cinq fractions d'oligomères de masse moléculaire moyenne entre 2127,42 et 8331,85 g/mol pour la rutine et 688,12 et 6973 g/mol pour l'esculine. L'analyse de ces fractions par FTIR montre que les fractions d'oligorutines sont obtenues à travers des liaisons C-C, C-O et C=O. Les fractions d'oligoesculines sont obtenues à travers des liaisons C-C. Une meilleure solubilité des oligorutines et des oligoesculines dans l'eau et une plus faible solubilité de ces oligomères dans l'éthanol comparé à leurs monomères a été mis en évidence. Une diminution de l'activité antiradicalaire vis-à-vis de DPPH., ABTS+. et OH. proportionnelle à la masse moléculaire moyenne des fractions d'oligorutines a été observé, contrairement aux fractions d'oligoesculines qui montrent un important pouvoir chélateur de ces mêmes radicaux comparé à leurs monomère. Une augmentation du pouvoir chélateur de fer, inhibiteur de la xanthine oxydase, réducteur du cuivre (CUPRAC), de l'activité antigénotoxique, ainsi que de l'activité stimulatrice de la prolifération des splénocytes, et des lymphocytes (B et T) proportionnelle au degré d'oligomérisation des oligomères étudiées a été noté. L'effet des fractions d'oligorutines et oligoesculines étudiées sur les macrophages en suivant la production de monoxyde d'azote (NO) montre un pouvoir anti-inflammatoire comparé à leurs monomères. L'étude de l'activité lysosomale induite par les fractions d'oligorutine révèle un pouvoir immunostimulateur proportionnelle à la masse moléculaire moyenne des oligorutines, et inversement proportionnelle à celle-ci pour les oligoesculines / Rutin and esculin have been polymerized by laccase. Five fractions with between 2127.42 and 8331.85 g/mol for oligorutins, and between 688.12 and 6973 g/mol for oligoesculins, were obtained. Fourier transformed infrared analysis showed that oligorutins were formed through C-C, C-O and C=O linkages, while oligoesculins were obtained through C-C linkages. Oligorutins and oligoesculins show a higher solubility in water and a lower solubility in ethanol compared to their monomers. The oligomerization of rutin decrease its antiradical capacity, while oligoesculin fractions demonstrated a high antiradical activity compared to monomeric esculin. Oligomer fractions showed a better iron chelating power, xanthine oxidase inhibition, copper reducing power (CUPRAC), antigenotoxic activity, and splenocytes stimulator activity compared to their monomers. Oligorutin and oligoesculin exhibited an important anti-inflammatory capacity through the nitric oxide inhibition. Moreover, oligorutin fractions demonstrated an immunostimulatory effect proportional to their degree of oligomerization, while oligoesculin fractions showed an immunostimulatory effect inversely proportional to their degree of oligomerization

Submitted by Simone Souza (simonecgsouza@hotmail.com) on 2017-09-20T14:37:32Z No. of bitstreams: 1 DISS_2014_Miguel Aprelino Alito.pdf: 4695957 bytes, checksum: 0f8d53c15612c14ec0bd4276f60d6c20 (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2017-09-26T12:50:06Z (GMT) No. of bitstreams: 1 DISS_2014_Miguel Aprelino Alito.pdf: 4695957 bytes, checksum: 0f8d53c15612c14ec0bd4276f60d6c20 (MD5) / Made available in DSpace on 2017-09-26T12:50:06Z (GMT). No. of bitstreams: 1 DISS_2014_Miguel Aprelino Alito.pdf: 4695957 bytes, checksum: 0f8d53c15612c14ec0bd4276f60d6c20 (MD5) Previous issue date: 2014-08-25 / Introdução: Protocolos multimodais, quando empregados, melhoram variáveis clínicas perioperatórias e pós-operatórias. Existe pouca informação sobre abreviação do jejum préoperatório com oferta de líquidos claros enriquecidos com carboidratos e imunomoduladores em operações ortopédicas. O projeto ACERTO (ACEleração da Recuperação Total pósoperatória) é baseado em um programa europeu já existente (ERAS) e fundamentado no paradigma da medicina baseada em evidências. É antes de tudo um programa educativo. Objetivos: Avaliar variáveis clínicas, bioquímicas inflamatórias e segurança de um protocolo multimodal em pacientes submetidos à cirurgia de artroplastia total do quadril, utilizando-se técnica cimentada em fêmur e sem cimento no acetábulo (artroplastia total de quadril tipo híbrida). Métodos: Estudo prospectivo com 32 pacientes (16 do sexo masculino, com idade média de 58 anos variando de 26 a 85 anos) randomizados em dois grupos: 17 pacientes (Grupo ACERTO) submetidos a jejum abreviado com oferta de maltodextrina a 12,5%, 2h antes da indução anestésica e uso de dieta imunomoduladora por cinco dias previamente a cirurgia; 15 pacientes (Grupo CONTROLE) submetidos a jejum de 8 horas sem terapia nutricional préoperatória. Foram avaliados clinicamente broncoaspiração na indução anestésica e tempo de internação e em exames laboratoriais os níveis de hemoglobina (HB), velocidade de hemossedimentação (VHS) e proteína C reativa (PCR) no pré-operatório e com 48h de pósoperatório. Resultados: Não ocorreram óbitos, infecções, luxações da prótese, necessidade de reoperação, ou transfusões sanguíneas. Nenhum caso de broncoaspiração ocorreu na indução anestésica. Pacientes do Grupo ACERTO apresentaram, em média, dois dias a menos de internação hospitalar (P < 0,01). A taxa de HB foi similar entre os grupos no pré e pósoperatório. Valores de VHS se mantiveram semelhantes entre os grupos no pós-operatório (p = 0,09), mas a PCR foi maior no grupo CONTROLE no pós-operatório (p = 0,01). Conclusão: Abreviação do jejum pré-operatório com oferta de carboidratos na artroplastia total de quadril é segura, podendo ser praticada. O protocolo investigado como um todo diminuiu o tempo de internação hospitalar e valores de PCR no pós-operatório. / Introduction: Multimodal protocols, when used, enhance several perioperative clinical variables. Limited information is available about the reduction of preoperative fasting with administration of clear liquids enriched with carbohydrate and immunomodulators in orthopedic surgeries. The ACERTO (Accelerated Postoperative Total Recovery) is based on an existing European program (ERAS) and based on the paradigm of evidence-based medicine. It is an educational program. Objectives: To evaluate clinical, biochemical inflammatory variables and safety of the method, shortening up the fast with drink containing carbohydrates and use of immunomodulatory diet in patients undergoing surgery for total hip arthroplasty using cementless technique on the femur and the acetabulum without cement (total hip arthroplasty hybrid type). Methods: A prospective study of 32 patients (16 males, with a mean age of 58 years ranging de 26 to 85 years) were randomized into two groups: 17 patients (Group ACERTO) undergoing abbreviated to offer 12,5% maltodextrin fasting, 2h before induction of anesthesia and use of immunomodulatory diet for five days prior to surgery; 15 patients (Group CONTROL) fasted for 8 hours without preoperative nutritional therapy. Clinically aspiration during induction of anesthesia and hospitalization time and in laboratory tests the levels of hemoglobin (Hb), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) preoperatively and 48 hours postoperatively were evaluated. Results: There were no deaths, infections, dislocations of the prosthesis, reoperation, or blood transfusions. No cases of aspiration occurred during anesthetic induction. Group ACERTO patients had, on average, two days less hospitalization (P < 0,01). Results of hemoglobin did not differ among groups in preoperative and postoperative. VHS values remained similar between groups postoperatively (p = 0,09), but CRP was higher in the control group postoperatively (p = 0,01). Conclusion: Preoperative fasting abbreviation with of carbohydrates in total hip arthroplasty is safe and may be practiced. The protocol investigated as a whole, decreased hospital stay and CRP levels postoperatively.

Made available in DSpace on 2014-07-29T15:16:36Z (GMT). No. of bitstreams: 1 Dissertacao Flavia de Castro Pereira UFG 2010 - part 1.pdf: 495954 bytes, checksum: 284a68ffbde993ede09791444dec1865 (MD5) Previous issue date: 2010-01-22 / Despite the resounding success of cisplatin and closely related platinum antitumor agents, the movement of other transition-metal antitumor agents toward the clinic has been exceptionally slow. Non-Platinum chemotherapeutic metallopharmaceuticals hold much promise for the future, and needs to be actively explored in a large variety of tumor types in combination therapies. The preparations of metallocomplexes with potential antitumor activity has been one of the main targets of transition metal chemistry since Rosenberg s discovery of cisplatin cisdiamminedichloridoplatinum (II), cis-[Pt(NH3)2Cl2]} cytotoxic activity in the 1960s. In 1978, cisplatin was approved as the first platinumbased drug for the oncology treatment, although several negative side-effects (nephrotoxicity, neurotoxicity, nausea, etc.) had been induced on treated patients. Nevertheless, cisplatin was followed by carboplatin {cis-diammine-1,1´ - yclobutanedicarboxylateplatinum(II), [Pt(NH3)2(cbdc)], approved in 1985} and oxaliplatin 1R,2Rdiamminocyclohexaneoxalatoplatinum(II), [Pt(dach)(ox)], approved in 1996}, which met requirements of improving antitumor activity and reducing disadvantages of cisplatin, carboplatin and oxaliplatin represent the second, and third platinum-based drug generations, respectively. Nowadays, not only platinum-bearing complexes are extensively studied with the aim to broaden a spectrum of transition metal-based complexes which could be used in the treatment of cancer. Ruthenium complexes have shown potential utility in chemotherapy and photodynamic therapy. Ruthenium complexes generally have lower toxicities compared to cisplatin attributed to their specific accumulation in cancer tissues. In vitro and in vivo studies show high anticancer activity of Ruthenium complexes and some of them are currently undergoing clinical trials. In the present work we studied the antitumor activity of the Ruthenium(III) compound cis-Tetraammine(oxalato)Ruthenium(III) Dithionate {cis- [Ru(C2O4)(NH3)4]2(S2O6)} against different tumor and normal cells lineages, analising cell viabilities, cell cycle distribution, apoptosis induction mecanistics and genome DNA damage. Correlation tests were performed to determine the effects of the time of exposure and concentration of Ruthenium complex on mitotic index (MI) and mitotic aberration index on Allium cepa root cells. A comparison of MI results of cis- [Ru(C2O4)(NH3)4]2(S2O6) to those of lead nitrate reveals that the Ruthenium complex demonstrates an average mitotic inhibition eightfold higher than lead, with the frequency of cellular abnormalities almost fourfold lower and mitotic aberration threefold lower. A. cepa root cells exposed to a range of Ruthenium complex concentrations did not display significant clastogenic effects. The cis- Tetraammine(oxalato)Ruthenium(III) Dithionate therefore exhibits a remarkable capacity to inhibit mitosis, perhaps by inhibiting DNA synthesis or blocking the cell cycle in the G2 phase. Results showed that Ruthenium(III) causes a significant reduction of proliferation of A549 cells with viabilities ranging from 55.5% to 24.6% when treated with 40 &#956;M for 24 and 48h; and 32% to 18.2% when treated with 150 &#956;M for 24 and 48h. The Ruthenium(III) compound induced a moderate (31.9% and 39.6% for concentrations 10 and 40 &#956;M, respectively) to high degree (74% for concentration 32 &#956;M) of cytotoxic activity against A549 cells (IC50= 33.72 &#956;M). On the other hand, the normal lung fibroblast MRC-5 did not show significant reduction proliferation in the presence of Ruthenium(III) compound. Even when treated with higher concentrations of cis-Tetraammine(oxalato)Ruthenium(III) Dithionate for 48 hours, MRC-5 cells showed viabilities ranging from 85% to 78,4% for 40 &#956;M and 150 &#956;M, respectively. The antiproliferative and cytotoxic activity revealed that K562 cells cultured with concentrations 40 and 150 &#956;g mL-1 of Ruthenium(III) compound showed significant reduction of proliferation after 72h of exposition, with viabilities ranging from 88.2% to 55.6% when treated with 40 &#956;M for 24 and 72h; and 76.2% to 26.7% when treated with 150 &#956;M for 24 and 72h. The Ruthenium(III) compound induced low [22.4% (24h) to 28.2% (48h) and 29.8% (24h) to 35.7% (48h) for concentrations 10 and 40 &#956;M, respectively] to moderate [44% (24h) and 53% (48h) for concentration 150 &#956;M] of cytotoxic activity against K562. After incubation for 48 h, the IC50 value was 18.28 &#956;M. Compared to the cell cycle profiles of untreated cells, flow cytometric analysis indicated a sub-G1 arresting effect of Ruthenium compound on K562 cells, inducing a 1.7-fold, 2.2-fold and 2.4-fold increase in the number of sub-G1 cells for 24, 48 and 72 h, respectively, when compared to control. The compound also caused a significant increase in tailed cells in any of the concentrations tested compared with negative control that can be associated cytotoxicity with direct effect on K562 cells DNA. / Apesar do sucesso da cisplatina e dos medicamentos à base de platina, o mercado de fármacos ainda é acessível para novas drogas á base de metal que oferecem uma melhor viabilidade, tais como a administração oral, o que pode ajudar a diminuir os efeitos colaterais graves e custos clínicos. Além disso, novos estudos concentram-se na investigação de novas drogas com maior eficácia, ou seja, drogas que interajam de forma diferente com o DNA, o que pode levar à superação da resistência inata ou adquirida de certos tipos de tumores. Dentre os vários complexos a base de metais desenvolvidos, os complexos de rutênio (III) representam uma nova família de promissores agentes anticâncer. No presente estudo foi investigado in vitro o efeito do composto Ditionato de cis- Tetraamino(oxalato)rutênio(III) sobre a viabilidade celular, distribuição das fases do ciclo celular, mecanismos de indução de apoptose e danos a molécula de DNA. Os resultados provenientes da análise do teste Allium cepa mostraram um efeito tempo dose-dependente. A avaliação mostrou que a concentração de rutênio teve um impacto maior do que o tempo de exposição. O efeito também se mostrou cumulativo, com uma quase completa inibição da mitose em uma concentração de rutênio de 0,1 mg mL-1 ou superior por períodos superiores a 24 h. Por outro lado, os resultados não revelaram efeitos clastogênicos significativos nas células meristemáticas expostas ao complexo de rutênio (III). A comparação entre os valores dos Índice Mitótico de células meristemáticas de cebolas tratadas com o complexo de rutênio em relação às células tratadas com nitrato de chumbo também mostrou que o complexo de rutênio induziu uma inibição mitótica média oito vezes maior do que o chumbo. Notadamente, as freqüências de anomalias e aberrações celulares mitóticas foram quase quatro vezes e três vezes menores, respectivamente. Os resultados mostram que o composto estudado causa significativa redução da proliferação das células A549 com viabilidades entre 55,5% para 24,6% quando tratados com 40 &#956;M por 24 e 48h; e 32% para 18,2% quando tratados com 150 &#956;M por 24 e 48h. O composto de rutênio(III) induz moderada (31,9% e 39,6% para concentrações 10 e 40 &#956;M, respectivamente) para alta degradação (74% para a concentração 150 &#956;M) para avaliação da atividade citotóxica das células A549 (IC50= 33,72 &#956;M). Quanto à linhagem de fibroblasto de pulmão humano normal MRC-5, não mostrou redução significativa na proliferação celular na presença do composto. Quando tratadas com altas concentrações do Ditionato cis-Tetraamino(oxalato)rutênio(III) por 48 horas, celulas MRC-5 mostraram viabilidades altas de 85% e 78,4% para 40 &#956;M e 150 &#956;M, respectivamente. A atividade citotóxica e antiproliferativa revelou que a cultura de células K562 nas concentrações de 40 e 150 &#956;g mL-1 do composto de Rutênio(III) mostrou redução significativa na proliferação 72h de exposição, com viabilidades de 88,2% para 55,6% quando tratadas com 40 &#956;M por 24 e 72h; e 76,2% para 26,7% quando tratadas com 150 &#956;M por 24 e 72h. O composto de Rutênio(III) induziu baixa [22,4% (24h) para 28,2% (48h) e 29,8% (24h) para 35,7% (48h) para concentrações de 10 e 40 &#956;M, respectivamente] para moderada [44% (24h) e 53% (48h) para concentrações de 150 &#956;M] atividade citotóxica em células K562. Após a incubação de 48 h, o valor da IC50 foi de 18,28 &#956;M. Quando comparado o ciclo celular de células não tratadas, a análise indica que as células foram arrastadas para sub-G1 apresentando um aumento de 1,7 para 2,2 e 2.4% no número de células em sub-G1 por 24, 48 e 72 h, respectivamente, quando comparado com o grupo controle. O composto também causou um significativo aumento em danos celulares nas concentrações testadas quando comparado com o controle negativo, o que pode estar associado com efeitos citotóxicos diretamente no DNA celular.

Les préparations de Viscum album (VA), connu sous le nom vernaculaire de gui européen, sont fréquemment utilisées en support des traitements anticancéreux, principalement pour améliorer la qualité de vie des malades et réduire la croissance des tumeurs. Elles sont connues pour exercer des effets anti-tumoraux. Il existe de plus en plus de données scientifiques faisant état de liens étroits entre cancer et inflammation. Étant donné que la prostaglandine E2 (PGE2) induite par la cyclo-oxygénase 2 (COX-2) joue un rôle clef dans l’inflammation, j’ai exploré la régulation du système COX-2-PGE2 par VA et ses mécanismes sous-jacents. J’ai montré que VA exerce ses effets anti-inflammatoires en inhibant sélectivement l’expression de COX-2 et en diminuant la production de PGE2 qui en découle, par le biais d’une déstabilisation de l’ARNm de COX-2. En plus de leurs propriétés cytotoxiques, il a été montré que les préparations de VA ont également des effets immunostimulants. Les différentes préparations de VA sont hautement hétérogènes du fait de leurs compositions biochimiques qui varient selon la récolte, l’espèce de l’arbre hôte et les méthodes de préparation qui peuvent influer sur leur efficacité clinique. De ce fait, j’ai réalisé une étude comparative sur cinq préparations de VA dans le but d’analyser leurs capacités de maturation et d’activation des cellules dendritiques (DC) qui peuvent à leur tour présenter une réponse immunitaire anti-tumorale. Les résultats ont montré que parmi les cinq préparations,VA Qu Spez induit de manière significative l’activation des DC et la sécrétion de cytokines pro-inflammatoires telle que l’IL-6, l’IL-8 et le TNF-α qui induisent la production d’IFN-γ,orientant de ce fait la réponse immunitaire vers une réponse Th1. L’orchestration de la11fonction des cellules myélomonocytiques est un élément central à l’interface entre inflammation et cancer. Il constitue un paradigme expliquant la plasticité et la fonction des macrophages. Mon étude met en évidence l’influence de VA Qu Spez sur la polarisation des macrophages qui passent d’un état alternatif (M2) à un état dit classique (ou M1). Les macrophages M2 sont connus pour polariser les réponses immunitaires Th2, pour participer à l’élimination des parasites, pour diminuer l’inflammation, pour promouvoir le remodelage tissulaire et la progression des tumeurs et pour avoir des fonctions immunorégulatrices. Les macrophages M1 sont impliqués dans la réponse Th1, favorisent la résistance aux pathogènes intracellulaires et aux tumeurs et promeuvent des réactions de désagrégation tissulaires. L’ensemble de ces résultats permet de comprendre les propriétés anti-inflammatoires et immunostimulantes des préparations de VA. Des recherches complémentaires permettront d’améliorer les stratégies d’utilisation thérapeutique de VA et son utilisation dans les soins de support aux traitements anticancéreux. / Viscum album (VA) preparations, commonly known as European mistletoe, are frequentlyused as complementary therapy in cancer, mainly to improve quality of life of the patients andto reduce the tumor growth. They are known to exert anti-tumoral effects. There is increasing evidence of the convoluted connection of cancer and inflammation. As cyclooxygenase-2(COX-2)-induced prostaglandin E2 (PGE2) plays a key role in the inflammation, I explored the regulation of COX-2-PGE2 axis by VA and underlying mechanisms. I found that VA exerts anti-inflammatory effects by selectively inhibiting COX-2 expression and ensuing PGE2 production. Inhibition of COX-2 expression implicates COX-2 mRNA destabilisation. In addition to their cytotoxic properties, they have also been shown to have immunostimulatory properties. Each VA preparations are highly heterogeneous because oftheir chemical composition which varies depending on the time of harvest, species of host treeand manufacturing methods, together which might influence clinical efficacy of VA.Therefore I performed a comparative study involving five different preparations of VA concerning maturation and activation of dendritic cells (DCs) which in turn may manifestanti-tumoral immune response. Results showed that among all five preparations, VA Qu Spez significantly induces DC activation, secretion of pro-inflammatory cytokines such as IL-6, Il-8 and TNF-α, enhancing IFN-γ production hence promoting Th1 immune response. The orchestration of myelomonocytic cell function is a key element that links inflammation and cancer and provides a paradigm for macrophage plasticity and function. My study reveals the effect of VA Qu Spez in switching the M2 macrophages which are known to participate inpolarizing Th2 responses, help with parasite clearance, dampen inflammation, promote tissue remodelling and tumor progression and have immunoregulatory functions, towards classicallyactivated M1 macrophages which are part of a polarized Th1 response and mediate resistance13to intracellular pathogens and tumors and elicit tissue-disruptive reactions. These results together should assist in understanding the anti-inflammatory and immunostimulatory properties of VA preparations and further research is warranted to improve the therapeutic strategies of use of VA and their role as complimentary therapy in cancer.

PhD (Microbiology) / Department of Microbiology / Background: Currently, Human Immunodeficiency Virus/ Acquired Immune Deficiency Syndrome (HIV/AIDS) is one of the deadliest diseases in the world. In Gabon, the prevalence is estimated at 4.1%. Because of the several side effects of highly active antiretroviral therapy on the health of people living with HIV, an emphasis on the utilization of based plant treatments have been noticed highlighted with testimonies of patient health improvement. That led researchers to conduct ethnobotanical surveys aiming at reporting medicinal plants used to treat HIV related opportunistic infections. From the outcomes, 20 plants have been selected based on the frequency of their use but also on the absence of papers in the literature related to HIV research conducted in Gabon. This study aims at evaluating the cytotoxicity, antioxidant, antimicrobial, anti-HIV and immunomodulatory activities of the 20 selected plants and to establish the phytochemical profile of these plants. Methodology: The plants were extracted using absolute methanol and distilled water. Qualitative (phytochemical screening) and quantitative (TPC and TFC) analysis were performed on the 40 extracts obtained. The extracts were assessed for cytotoxicity on Vero and HeLa cells using MTT and dual staining/fluorescence microscopy. The antimicrobial activity of the extracts was evaluated using well diffusion assay and micro-broth dilution assay. DPPH free radical scavenging assay and ferric reducing power were used to determine the antioxidant potential of the extracts. The anti-HIV effect was evaluated on HIV infected blood using reverse transcriptase inhibitory assay and p24 antigen inhibitory assay. The immunomodulatory effects of the extracts were evaluated on HIV infected blood using IL-2, IL-6 and TNF-α ELISA. Coula edulis and T. iboga methanol extracts were selected for fractionation using column chromatography. LC-MS was used to establish the phytochemical profile of the two selected extracts. Results: The results revealed that saponins, alkaloids, terpenoids, phenols, tannins, steroids, flavonoids and cardiac glycosides were detected in almost all the plant extracts. The extracts were found to contain more phenolics than flavonoids especially the methanolic extracts. Both alcoholic and aqueous extracts of C. edulis, M. cecropioides, S. ochocoa, S. kamerounensis, U. guineensis and C. religiosa, the methanolic extract of A. hirtella and R. vomitoria and the aqueous extracts of U. klainei presented IC50 significantly lower (p<0.05) than ascorbic acid (38.87±1.54 μg/ml). Both Coula edulis methanolic and aqueous extracts, methanolic extracts of S. kamerounensis, S. gabonensis, M. monandra, U.guineensis and A. klaineana showed antioxidant activity significantly xii | P a g e (p<0.01) higher than Ascorbic acid whose EC50 was 152.16±1.09 μg/ml. For the fluorescence microscopy the extracts of interest for Vero cells inhibition were A. klaineana, T. iboga, U. klainei and C. edulis while for Hela cells the cytotoxic activity was significant (p<0.05) for the following extracts: U. klainei, U. guineensis, P. soyauxii, A. klaineana, V. conferta, M. monandra, R. vomitoria, R. africanum, C. edulis and S. ochocoa. The extracts of C. edulis, M. cecropioides, S. ochocoa, S. gabonensis, A. hirtella, R. vomitoria, S. kamerunensis, P. soyauxii, U. guineensis and T. iboga displayed the highest antimicrobial activity against all the selected bacteria. For the anti-HIV the extracts of interest were V. conferta (47%), C. lucanusianus (47%), C. religiosa (44%), A. hirtella (42%), S. kamerunensis (41%), M. puberula (41%) as well as both aqueous and methanolic extracts of T. iboga (48% and 45% respectively), U. guineensis (46% and 41% respectively) and A. klaineana (41% and 44% respectively). The results for RT inhibition assay revealed that out of 24 selected plant extracts selected only C. edulis, C. religiosa, C. lucanusianus, R. africanum, P. soyauxii and V. conferta were able to decrease RT by more than 50%. The modulatory effect of the extracts on the secretion of IL-2, IL-6 and TNF-α by HIV infected cells was found to be insignificant (p>0.05). The fractionation of T. iboga and C. edulis methanol extracts eluted 4 fractions each. The LC-MS analysis revealed at negative ionization the presence of phenolic compounds (Ellagic acid, Gallic acid, and quercetin) in C. edulis samples while alkaloids (ibogaine, ibogaline, voacangine) were mainly found in T. iboga samples at positive ionization. The two crude extracts and the fractions showed some levels of antimicrobial, antioxidant, anti-HIV and anti-inflammatory activities. Conclusion: The present study has validated the use of the selected plants in the management of AIDS in Gabon and provided an explanation of the improvement in HIV individual’s life reported. Some of these plants could constitute good candidate for promising anti-HIV molecules. / NRF

Multiple Sklerose (MS) ist eine heterogene Krankheit des Zentralnervensystems, deren pathologische Mechanismen noch nicht vollständig aufgeklärt sind. Die gegenwärtige Hypothese ist, daß pro-inflammatorische T-Zellen entscheidend an der Pathogenese der MS beteiligt sind. Man geht davon aus, daß eine Fehlregulation der T-Zell-Kontrolle, möglicherweise bedingt durch ein Ungleichgewicht an Apoptose-regulierenden Molekülen, dabei eine Rolle spielt. Tatsächlich zielen therapeutische Strategien darauf ab, T-Zell-Aktivierung, Proliferation und Produktion von Zytokinen zu verringern, oder T-Zell-Eliminierung zu fördern. Diese Arbeit sollte zum einen die Bedeutung regulatorischer Faktoren klären, die für das überleben der T-Zellen von MS-Patienten verantwortlich sind. Zum anderen sollten die antiproliferative oder Apoptose-fördende Wirkung potentiell therapeutisch wirksamer Moleküle untersucht werden. Eine eingeschränkte Regulation der autoreaktiven T-Zellen durch Apoptose in der Peripherie und im ZNS trägt möglicherweise zur Pathophysiologie der MS bei. Als Schlüsselfaktoren der Regulation von Apoptose wurden Mitglieder der Bcl-2-Familie in MS-Patienten und Probanden untersucht. Diese Faktoren wurden in Relation zu der Suszeptibilität der T-Zellen gegenüber aktivierungsinduziertem Zelltod (sog. Activation-induced cell death oder AICD) überprüft. Um die in-vivo-Elimination der Antigen-reaktiven T-Zellen nachzuahmen, wurde ein in-vitro-Modell des AICD mit repetitiver T-Zell-Stimulation verwendet. Tatsächlich zeigten polyklonale T-Zellen von MS-Patienten eine verringerte Suszeptibilität für AICD, nachgewiesen sowohl durch verminderte Caspaseaktivtät (p=0.013) als auch durch DNA-Fragmentierung (p=0.0071). Weiter wurden höhere Spiegel des Proteins Bcl-XL in den Immunzellen von MS-Patienten mit Immunoblotting gemessen (p=0.014). Eine inverse Korrelation zwischen der Expression an Bcl-XL und der Empfindlichkeit der T-Zellen gegenüber AICD steht in Übereinstimmung mit vorhergehenden Daten bezüglich der Bedeutung dieses Proteins für die Apoptose-Resistenz von T-Zellen. Es wurde bereits gezeigt, daß dieses Molekül die Ausprägung der experimentell-autoimmun Enzephalomyelitis, des Tiermodells der MS, verstärkt. Zusammen mit den erhöhten Bcl-XL-Werten bei MS-Patienten, ergeben sich nun Perspektiven für einen therapeutischen Ansatz. Abgesehen von dem Konzept die apoptotische Eliminierung von T-Zellen zu unterstützen, streben gegenwärtige therapeutische Strategien an, die Aktivierung und weitere Proliferation der schädlichen T-Zellen zu hemmen. Basierend auf klinischer Erfahrung mit eher unselektiven Therapien, ist es ein therapeutisches Ziel, neue immunomodulatorische Substanzen mit besserer Selektivität zu finden, um das Nutzen/Risiko-Verhältnis zu maximieren. Aus diesem Grund wurden zwei unterschiedliche Substanzen untersucht die beide den Zellzyklus beeinflussen. Als erster Kandidat wurde der kürzlich entdeckte Todesligand TRAIL (engl.: TNF-related apoptosis inducing ligand) aus der TNF/NGF-Familie untersucht, da diesem bereits T-Zell-regulatorische Funktionen zugeschrieben worden waren, humane Antigen-spezifische T-Zellen jedoch resistent gegenüber TRAIL-induzierter Apoptose sind. Der zweite Kandidat mit potenziell therapeutischer Wirkung bei MS ist Atorvastatin, ein HMG-CoA-Reduktase-Hemmer, der bereits als Lipidsenker bei Patienten eingesetzt wird. Um die Hypothese zu überprüfen, daß diese Substanzen T-Zell-Rezeptor-Signale beeinflussen können, wurden humane Antigen-spezifische T-Zell-Linien von MS-Patienten und gesunden Probanden eingesetzt. Diese wurden hinsichtlich T-Helfer-Phänotyp und Peptid-Spezifität charakterisiert. Eine Behandlung mit TRAIL führte zur Hemmung der Proliferation in unterschiedlichem Ausmaß (6.2% - 63.8%). Atorvastatin hemmte in Abhängigkeit von der Dosis ebenso die Proliferation Antigen-spezifischer T-Zellen. Beide Substanzen wirkten antiproliferativ unabhängig von der Antigenpräsentation, aufgrund ihrer Fähigkeit, die Proliferation in Abwesenheit von professionellen Antigen-präsentierenden Zellen zu vermindern. Diese Eigenschaft weißt auf einen direkten Einfluß auf die T-Zell-Funktion hin. Die TRAIL-induzierte Hypoproliferation war assoziiert mit einer Herunterregulation der Zyklin-abhängigen Kinase CDK4 (engl.: cyclin dependent kinase 4), einem Schlüsselenzym für die nach T-Zell-Rezeptor-Stimulation einsetzende Transition von der G1- zur S-Phase des Zellzyklus. Inkubation mit Atorvastatin induzierte ebenso eine Verminderung von CDK4, begleitet von einer Erhöhung von p27Kip1. Die Atorvastatin-vermittelte Proliferations- und Zellzyklus-Blockade konnte durch Mevalonat rückgängig gemacht werden. Mevalonat ist ein Zwischenprodukt des HMG-CoA-Reduktaseweges. Atorvastatin scheint demnach einen direkten Einfluß auf diese Enzymkaskade zu haben, der wichtig für die Isoprenylierung von GTPase-Proteinen der Rho-Familie ist. T-Zell-Rezeptor-Stimulation führt zur Freisetzung von Kalzium aus intrazellulären Speichern und nachfolgend zur Öffnung transmembranöser Kalzium-Kanäle (sog. calcium release-activated calcium oder CRAC-Kanäle), die eine für die T-Zellaktivierung notwendige und anhaltende Erhöhung der intrazellulären Kalzium-Konzentration hervorruft. Nach Behandlung mit TRAIL wurde eine konzentrationsabhängige Inhibition des Einstroms extrazellulärer Kalzium-Ionen durch die CRAC-Kanäle beobachtet. Dies wurde mit löslichem TRAIL-Rezeptor-Fusionsprotein, einem TRAIL-Antagonisten, rückgängig gemacht. Die Blockade von Kalzium-abhängigen Aktivierungssignalen stellt damit möglicherweise einen primären immunregulatorischen Mechanismus für diese Todesliganden dar. Jedoch wurde keine Auswirkung von Atorvastatin auf die T-Zellaktivierung beobachtet, da der Einstrom von extrazellulärem Kalzium nicht beeinflußt wurde. Während Studien zum TRAIL-vermittelten Einfluß auf die T-Zell-Aktivierung und dem Zellzyklus erst in der präklinischen Phase sind, werden Statine, die ebenfalls den Zellzyklus beeinflussen, bereits in der Therapie anderer Erkrankungen angewand. Darüber hinaus werden derzeit bereits klinische Studien mit Statinen zur MS-Therapie durchgeführt. Weitere Untersuchungen zu den detaillierten Mechanismen antiproliferativer Substanzen mit potenziellem therapeutischen Effekt in der MS ermöglichen die Entwicklung von selektiveren immunomodulatorischen Therapien mit höherem therapeutischen Nutzen für MS-Patienten. / Multiple sclerosis (MS) is a heterogeneous disease of the central nervous system whose pathological mechanisms are far from completely understood. The current hypothesis is that pro-inflammatory T cells are orchestrating the pathogenesis of this condition. It is considered that a dysregulation in T cell control to be involved, with an imbalance in apoptosis-regulating molecules possibly playing a role. In fact, therapeutic strategies aim to reduce T cell activation, proliferation and cytokine production or to promote T cell elimination. The focus of this thesis was to identify the role of regulatory molecules for T cell survival in the immune pathogenesis of MS, and to investigate antiproliferative or apoptosis-promoting effects on T cells by potential therapeutic molecules. A limitation in the apoptotic regulation of autoreactive T cells in the periphery and in the CNS may contribute to the pathophysiology of MS. As key regulators of apoptosis, members of the Bcl-2 family were investigated in both MS patients and controls. These factors were examined in relation to the susceptibility of T cells, from both groups, towards activation-induced cell death (AICD). To mimic the in vivo elimination of antigen-reactive T cells, an in vitro model of AICD involving repetitive T cell receptor mediated stimulation was utilized. In fact, polyclonal T cells from MS patients showed a decreased susceptibility to undergo AICD as shown by both caspase activity (p=0.013) and DNA fragmentation (p=0.0071) assays. Furthermore, Bcl-XL protein levels, as measured by immunoblotting, were increased in the peripheral immune cells of MS patients (p=0.014). An inverse correlation observed between Bcl-XL levels and susceptibility of T cells to undergo AICD is in line with previous data on the significance of this anti-apoptotic protein in T cell resistance. Since this molecule has already been shown to aggravate the outcome of experimental autoimmune encephalitis, the animal model for MS, the observation of elevated Bcl-XL levels in patients offers perspectives towards therapeutic manipulation in MS. Apart from promoting apoptotic elimination, current therapeutic strategies aim at inhibiting activation and further proliferation of potentially harmful T cells. Based on clinical experience with rather non-selective therapies that promote T cell elimination, a therapeutic goal is to identify newer immunomodulatory substances with better selectivity in order to maximize the therapy's benefit to risk ratio. Thus, two different substances, both interfering with cell cycle regulation, were investigated. The first candidate was the recently discovered member of the TNF/NGF family of death ligands, TNF-related apoptosis inducing ligand (TRAIL) since it has been reported to have immunoregulatory functions and since human antigen-specific T cells were shown to be resistant towards apoptosis induction by this ligand. The second candidate drug with potential in MS therapy is atorvastatin, a 3-hydroxy-3-methylglutaryl coenzyme (HMG-CoA) reductase inhibitor and lipid-lowering drug, already indicated for anomalies in lipid metabolism. In order to prove the hypothesis that these substances interfere with T cell receptor signaling, human antigen-specific T cell lines from both MS patients and controls, characterized with regards to T helper differentiation and peptide specificity, were employed. Exogenous treatment of TRAIL resulted in an inhibition in proliferation, albeit to varying degrees (6.2% - 63.8% inhibition). Atorvastatin also inhibited proliferation of antigen-specific T cell lines in a dose-dependent manner. Both compounds induced hypoproliferation independently of antigen presentation, as shown by their ability to block T cell proliferation in response to direct T cell receptor engagement, thus indicating a direct influence on T cell function. The growth inhibition by TRAIL was associated with a downregulation of the cell cycle regulator CDK4, indicative of an inhibition of cell cycle progression at the G1/S transition. Incubating T cells with atorvastatin also induced a downregulation of CDK4 expression, which was accompanied by an upregulation of p27Kip1 expression. The atorvastatin-mediated inhibition in proliferation and cell cycle progression could be reversed by mevalonate, an intermediate product of the HMG-CoA reductase pathway, suggesting a direct involvement of atorvastatin in this pathway, necessary for the isoprenylation of small GTPase proteins of the Rho family. Utilizing a thapsigargin model of calcium influx to activate the same calcium-release activated calcium (CRAC) channels as T cell receptor-stimulation by antigen, an inhibition in calcium influx could be observed on pre-incubating T cells with TRAIL. Co-incubating with human recombinant TRAIL receptor 2 fusion protein, a competitive antagonist for TRAIL, reversed this inhibition. A direct influence on calcium influx is indicative of an influence of TRAIL on the activation status of human T cells. Therefore, TRAIL directly inhibits activation of these cells via blockade of calcium influx. However, no impact of atorvastatin on early T cell activation was observed, since calcium influx was unaffected. While TRAIL-mediated interference with T cell activation and further cell cycle progression is still in the pre-clinical phase, statins, which have also been shown here to interfere with the T cell cycle, are already employed in the clinic for other ailments. In fact, clinical trials are currently being undertaken with this group of drugs for MS. Further studies on detailed mechanisms of antiproliferative substances effective in MS will allow the development of highly selective immunomodulatory agents with increased beneficial profile as MS therapy.