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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.
1

Síntese e atividade anti-Trichomonas vaginalis de chalconas

Trein, Marcia Rodrigues January 2017 (has links)
Tricomoníase é a doença sexualmente transmissível não-viral mais comum no mundo e pode gerar sérias consequências na saúde reprodutiva, câncer e transmissão e aquisição do HIV. Por esta razão, esta infecção resulta em um pesado fardo para os sistemas de saúde pública. O único tratamento aprovado para esta infecção, que consiste nos 5-nitromidazois metronidazol e tinidazol, apresenta efeitos adversos e há uma subestimada taxa de resistência da infecção, atualmente considerada uma doença negligenciada, a estes fármacos. Portanto, há uma necessidade urgente de novas alternativas terapêuticas para a tricomoníase. Chalconas são uma família de moléculas que apresenta várias aplicações biológicas, como atividade contra diversos patógenos, incluindo protozoários patogênicos. Este trabalho apresenta o potencial anti-Trichomonas vaginalis de derivados de chalcona sintetizados e seus efeitos sobre os trofozoítos. Os valores de IC50 dos compostos mais ativos variaram de 27,5 a 76,4 μM, e as moléculas 4’-hidroxichalcona e 3’-aminochalcona apresentaram os valores mais baixos (27,5 e 28,9 μM). Estes dois compostos foram citotóxicos contra a linhagem de células epiteliais vaginais HMVII, consequentemente apresentaram baixos Índices de Seletividade; contudo, ao se utilizar larvas de Galleria mellonella, como modelo de toxicidade in vivo, não foi observada diminuição da viabilidade após o tratamento. As moléculas também não provocaram hemólise em eritrócitos humanos em 1 e 24 horas. Os compostos não induziram significativa produção de espécies reativas de oxigênio (EROs) nos trofozoítos. Neutrófilos humanos apresentaram aumento na produção de EROs quando coincubados com trofozoítos tratados com os compostos. Os resultados indicam que as chalconas são uma família de moléculas com potencial atividade contra T. vaginalis. / Trichomoniasis is the most common non-viral sexually transmitted disease worldwide and can lead to serious consequences in reproductive health, cancer and HIV acquisition. For this reason, this infection results in a heavy burden for public health systems. Current approved treatment, which consists in 5-nitromidazole drugs, metronidazole and tinidazole, present adverse effects and there is underestimate drug resistance data on this parasitic infection, currently considered a neglected disease. Therefore, there is an urgent need for new alternatives for trichomoniasis treatment. Chalcones are a family of molecules that present various biological applications, such as activity against many pathogenic organisms including protozoan pathogens. This study presents the anti-Trichomonas vaginalis potential of synthetized chalcone derivatives and their effects on the trophozoites. IC50 values of the most active compounds ranged from 27.5 to 76.4 μM, and 4’-hydroxychalcone and 3’- aminochalcone presented the lowest values of IC50 (27.5 and 28.9 μM). These two compounds showed cytotoxicity against HMVII vaginal epithelial cells, thus presenting a low Selectivyty Index; however, when Galleria mellonella larvae were used as model for in vivo toxicity no significant decrease in viability after treatment was observed. The chalcones also did not induce hemolysis in human erythrocytes The compounds did not induce significant reactive oxygen species (ROS) production in the trophozoites. Human neutrophils have increased ROS production when exposed to treated trophozoites. Results indicate that chalcones are a family of molecules with potential activity against T. vaginalis.
2

Síntese e atividade anti-Trichomonas vaginalis de chalconas

Trein, Marcia Rodrigues January 2017 (has links)
Tricomoníase é a doença sexualmente transmissível não-viral mais comum no mundo e pode gerar sérias consequências na saúde reprodutiva, câncer e transmissão e aquisição do HIV. Por esta razão, esta infecção resulta em um pesado fardo para os sistemas de saúde pública. O único tratamento aprovado para esta infecção, que consiste nos 5-nitromidazois metronidazol e tinidazol, apresenta efeitos adversos e há uma subestimada taxa de resistência da infecção, atualmente considerada uma doença negligenciada, a estes fármacos. Portanto, há uma necessidade urgente de novas alternativas terapêuticas para a tricomoníase. Chalconas são uma família de moléculas que apresenta várias aplicações biológicas, como atividade contra diversos patógenos, incluindo protozoários patogênicos. Este trabalho apresenta o potencial anti-Trichomonas vaginalis de derivados de chalcona sintetizados e seus efeitos sobre os trofozoítos. Os valores de IC50 dos compostos mais ativos variaram de 27,5 a 76,4 μM, e as moléculas 4’-hidroxichalcona e 3’-aminochalcona apresentaram os valores mais baixos (27,5 e 28,9 μM). Estes dois compostos foram citotóxicos contra a linhagem de células epiteliais vaginais HMVII, consequentemente apresentaram baixos Índices de Seletividade; contudo, ao se utilizar larvas de Galleria mellonella, como modelo de toxicidade in vivo, não foi observada diminuição da viabilidade após o tratamento. As moléculas também não provocaram hemólise em eritrócitos humanos em 1 e 24 horas. Os compostos não induziram significativa produção de espécies reativas de oxigênio (EROs) nos trofozoítos. Neutrófilos humanos apresentaram aumento na produção de EROs quando coincubados com trofozoítos tratados com os compostos. Os resultados indicam que as chalconas são uma família de moléculas com potencial atividade contra T. vaginalis. / Trichomoniasis is the most common non-viral sexually transmitted disease worldwide and can lead to serious consequences in reproductive health, cancer and HIV acquisition. For this reason, this infection results in a heavy burden for public health systems. Current approved treatment, which consists in 5-nitromidazole drugs, metronidazole and tinidazole, present adverse effects and there is underestimate drug resistance data on this parasitic infection, currently considered a neglected disease. Therefore, there is an urgent need for new alternatives for trichomoniasis treatment. Chalcones are a family of molecules that present various biological applications, such as activity against many pathogenic organisms including protozoan pathogens. This study presents the anti-Trichomonas vaginalis potential of synthetized chalcone derivatives and their effects on the trophozoites. IC50 values of the most active compounds ranged from 27.5 to 76.4 μM, and 4’-hydroxychalcone and 3’- aminochalcone presented the lowest values of IC50 (27.5 and 28.9 μM). These two compounds showed cytotoxicity against HMVII vaginal epithelial cells, thus presenting a low Selectivyty Index; however, when Galleria mellonella larvae were used as model for in vivo toxicity no significant decrease in viability after treatment was observed. The chalcones also did not induce hemolysis in human erythrocytes The compounds did not induce significant reactive oxygen species (ROS) production in the trophozoites. Human neutrophils have increased ROS production when exposed to treated trophozoites. Results indicate that chalcones are a family of molecules with potential activity against T. vaginalis.
3

Síntese e atividade anti-Trichomonas vaginalis de chalconas

Trein, Marcia Rodrigues January 2017 (has links)
Tricomoníase é a doença sexualmente transmissível não-viral mais comum no mundo e pode gerar sérias consequências na saúde reprodutiva, câncer e transmissão e aquisição do HIV. Por esta razão, esta infecção resulta em um pesado fardo para os sistemas de saúde pública. O único tratamento aprovado para esta infecção, que consiste nos 5-nitromidazois metronidazol e tinidazol, apresenta efeitos adversos e há uma subestimada taxa de resistência da infecção, atualmente considerada uma doença negligenciada, a estes fármacos. Portanto, há uma necessidade urgente de novas alternativas terapêuticas para a tricomoníase. Chalconas são uma família de moléculas que apresenta várias aplicações biológicas, como atividade contra diversos patógenos, incluindo protozoários patogênicos. Este trabalho apresenta o potencial anti-Trichomonas vaginalis de derivados de chalcona sintetizados e seus efeitos sobre os trofozoítos. Os valores de IC50 dos compostos mais ativos variaram de 27,5 a 76,4 μM, e as moléculas 4’-hidroxichalcona e 3’-aminochalcona apresentaram os valores mais baixos (27,5 e 28,9 μM). Estes dois compostos foram citotóxicos contra a linhagem de células epiteliais vaginais HMVII, consequentemente apresentaram baixos Índices de Seletividade; contudo, ao se utilizar larvas de Galleria mellonella, como modelo de toxicidade in vivo, não foi observada diminuição da viabilidade após o tratamento. As moléculas também não provocaram hemólise em eritrócitos humanos em 1 e 24 horas. Os compostos não induziram significativa produção de espécies reativas de oxigênio (EROs) nos trofozoítos. Neutrófilos humanos apresentaram aumento na produção de EROs quando coincubados com trofozoítos tratados com os compostos. Os resultados indicam que as chalconas são uma família de moléculas com potencial atividade contra T. vaginalis. / Trichomoniasis is the most common non-viral sexually transmitted disease worldwide and can lead to serious consequences in reproductive health, cancer and HIV acquisition. For this reason, this infection results in a heavy burden for public health systems. Current approved treatment, which consists in 5-nitromidazole drugs, metronidazole and tinidazole, present adverse effects and there is underestimate drug resistance data on this parasitic infection, currently considered a neglected disease. Therefore, there is an urgent need for new alternatives for trichomoniasis treatment. Chalcones are a family of molecules that present various biological applications, such as activity against many pathogenic organisms including protozoan pathogens. This study presents the anti-Trichomonas vaginalis potential of synthetized chalcone derivatives and their effects on the trophozoites. IC50 values of the most active compounds ranged from 27.5 to 76.4 μM, and 4’-hydroxychalcone and 3’- aminochalcone presented the lowest values of IC50 (27.5 and 28.9 μM). These two compounds showed cytotoxicity against HMVII vaginal epithelial cells, thus presenting a low Selectivyty Index; however, when Galleria mellonella larvae were used as model for in vivo toxicity no significant decrease in viability after treatment was observed. The chalcones also did not induce hemolysis in human erythrocytes The compounds did not induce significant reactive oxygen species (ROS) production in the trophozoites. Human neutrophils have increased ROS production when exposed to treated trophozoites. Results indicate that chalcones are a family of molecules with potential activity against T. vaginalis.
4

Caractérisation des canaux calciques dans les polynucléaires neutrophiles : rôle dans la phagocytose et la production des radicaux libres oxygénés / Characterization of calcium channels in polymorphonuclear neutrophils : role in phagocytosis and reactive oxygen species

Djillani, Alaeddine 26 September 2013 (has links)
Les polynucléaires neutrophiles représentent 50-70% des leucocytes sanguins et possèdent un rôle majeur dans la défense de l’organisme contre les pathogènes. Le Ca2+ est un second messager qui joue un rôle primordial dans le chimiotactisme, la phagocytose, la dégranulation et la production de formes réactives de l’oxygène (FRO) afin de neutraliser l’agent pathogène. Dans ces cellules, l’influx calcique de type SOCE est essentiel pour l'homéostasie calcique. Il est peu étudié en raison du manque d’outils pharmacologiques spécifiques d’où l’importance dans un premier temps de chercher de nouvelles molécules. Les cellules T Jurkat dont le SOCE est largement caractérisé servent de modèle pour la caractérisation initiale de ces molécules. Le 2-APB est parmi les molécules les plus largement utilisées dans la caractérisation du SOCE en raison de sa double activité sur le SOCE avec une potentialisation à [1-10 μM] et une inhibition à [> 20 μM]. En revanche, ce produit manque de spécificité et agit sur d’autres cibles cellulaires comme les récepteurs à l’inositol (1,4,5)-trisphosphate (InsP3Rs). La 1ère étape est de sélectionner à partir d’analogues commerciaux du 2-APB (Methoxy-APB, Dimethoxy-APB, Cyclic-APB, Benzothienyl-APB, Thienyl-APB et MDEB), des composés plus spécifiques et également plus efficaces que la molécule mère. Deux molécules se sont distinguées : le MDEB comme uniquement potentialisant du SOCE et le Benzothienyl-APB comme un puissant inhibiteur. En revanche, tous les analogues du 2-APB inhibent les InsP3Rs à l’exception du MDEB qui semble plus spécifique du SOCE. L’effet du MDEB sur le courant calcique, ICRAC, a été étudié grâce à la technique du patch-clamp. Il augmente d’environ 4 fois l’amplitude de ICRAC par rapport à celle enregistrée dans les cellules contrôle. Par ailleurs, le MDEB ralentie l’inactivation rapide de ICRAC due au Ca2+. Sur le plan physiologique, le MDEB à des concentrations croissantes inhibe la synthèse de l’IL-2 dans les cellules Jurkat stimulées et ceci malgré son effet potentialisant du SOCE. Cette activité est liée à son effet pro-apoptotique dans les cellules Jurkat stimulées. Le MDEB et le Benzothienyl-APB caractérisés dans la 1ère partie nous ont servi d’outils potentiels afin d’étudier le SOCE des cellules PLB-985 différenciées en cellules proches de neutrophiles. Le SOCE a été induit soit par un traitement des cellules avec la thapsigargine (Tg) soit de manière physiologique avec les peptides fMLF et le WKYMVm deux chimioattractants, ligands des récepteurs aux peptides formylés FPR et FPRL1 respectivement. En plus, le SOCE induit par la Tg est modulable par le 2-APB, potentialisé par le MDEB et inhibé par le Benzothienyl-APB. La phagocytose des levures par les cellules PLB-985 différenciées ainsi que la production de FRO intraphagosomales ont été inhibées par le MDEB et le Benzothienyl-APB. Les FRO extracellulaires ont été également inhibées par Benzothienyl-APB en revanche à cause de la forte interférence du MDEB avec la technique de mesure nous n’avons pas pu étudier ses activités. En conclusion, le MDEB et le Benzothienyl-APB sont de nouveaux outils pharmacologiques potentialisant ou inhibant le SOCE des leucocytes, qui nous permettront dans l’avenir une meilleure compréhension de l'entrée calcique et ses rôles dans ces cellules. / Neutrophils represent 50-70% of human blood leukocytes; their role is to protect the body against pathogens. Calcium is a second messenger which plays an important role in chemotaxis, phagocytosis, degranulation and the production of reactive oxygen species (ROS) in order to eliminate microbes. In neutrophils, the mechanism of store-operated calcium entry (SOCE) is essential for calcium homeostasis. However, neutrophil SOCE is not well understood because of the lack of specific pharmacological tools. It is necessary to first identify and characterize new molecules using a model of Jurkat T cells in which SOCE was the best characterized. 2-APB is the most widely used molecule in SOCE characterization due to its dual activity with a potentiation at lower concentrations [1-10 μM] and an inhibition at higher concentrations [> 20 μM]. However, this molecule lacks specificity because it acts on other cellular targets such as inositol (1,4,5)-trisphosphate receptors (InsP3Rs). The first step is to select from a library of 8 commercial 2-APB analogues (Methoxy-APB, Dimethoxy-APB, Cyclic-APB, Benzothienyl-APB, Thienyl-APB and MDEB) those that are more specific and also more efficient molecules than 2-APB. Two interesting molecules were identified, MDEB as the only SOCE potentiating product currently known and the Benzothienyl-APB, which is a strong inhibitor. Like 2-APB, all these analogues inhibit InsP3Rs except MDEB, which seems to be more specific. The effect of MDEB on the calcium current, ICRAC, was also studied using the patch-clamp technique. MDEB increases ~4 times the ICRAC amplitude in comparison with control. Otherwise, MDEB slows down the fast Ca2 +-dependent inactivation of ICRAC. Functionally, MDEB at increasing concentrations inhibits IL-2 synthesis in stimulated Jurkat T cells despite its potentiating activity on SOCE. The inhibition is due to MDEB induced apoptosis in stimulated Jurkat T cells. MDEB and Benzothienyl-APB were then used as tools to study SOCE in a neutrophil-like cell model, the differentiated PLB-985 cells. SOCE was induced either by treatment of cells with thapsigargin (Tg) or physiologically with the chemotactic peptides fMLF and WKYMVm, ligands of formyl peptide receptors FPR and FPRL1 respectively. In addition, Tg-induced SOCE was modulated by 2-APB, potentiated by MDEB and inhibited by Benzothienyl-APB. The consequences of these analogues on neutrophil functions were also studied. Phagocytosis of yeasts by PLB-985 cells and intraphagosomal ROS production were inhibited by MDEB and Benzothienyl-APB. Furthermore, extracellular ROS were also inhibited by Benzothienyl-APB. However, because of the high interference of MDEB with our techniques, its activities could not be studied. In conclusion, MDEB and Benzothienyl-APB are new analogues of 2-APB potentiating and inhibiting SOCE, which allow us in the future a better understanding of leukocyte SOCE and its cellular roles.

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