• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 44
  • 18
  • 3
  • 3
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 91
  • 75
  • 12
  • 11
  • 10
  • 9
  • 9
  • 9
  • 9
  • 9
  • 8
  • 8
  • 8
  • 8
  • 8
  • 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.
81

Compound discovery and expression of a putative cathepsin D-like protease in Trichomonas vaginalis

Dornbush, Padraick J. 01 January 2014 (has links) (PDF)
Trichomonas vaginalis is a sexually-transmitted parasite that is the causative agent in the disease trichomoniasis. Resistance to the only FDA-approved medication to this disease, metronidazole, has been on the increase giving rise to the need for finding targets for new inhibitors to exploit. New inhibitors can target enzymes such as 4-coumarate:CoA ligase and S-adenosylhomocysteine hydrolase. Another potential target is a cathepsin D-like protease found in T. vaginalis . This aspartic protease in humans is responsible for degrading proteins in the lysosome, and degrading hemoglobin in P. falciparum as the homologue plasmepsin. Searching the gene database, only one cathepsin-D like protease was discovered throughout the organism's genome. Utilizing RT-PCR, this gene is found to be expressed in two different strains of the organism. Transfection of an epitope-tagged version of this cathepsin D-like protease into T. vaginalis was accomplished, and subsequent immunofluorescence of this tagged version shows it to be localized in intracellular compartments, which can be colocalized using the SNARE and VAMP proteins found in T. vaginalis .
82

Synthèse de dérivés 5-nitroimidazoles à potentialités anti-infectieuses. / Synthesis of new potentially anti-infectious 5-nitroimidazole derivatives

Zink, Laura 07 December 2012 (has links)
L'objectif de ce travail consiste en la synthèse de nouveaux 5-nitroimidazoles fonctionnalisés à visée thérapeutique. Dans un premier temps, l'étude de la réactivité du 4-bromo-1,2-diméthyl-5-nitro-1H-imidazole vis-à-vis du couplage de Suzuki-Miyaura sous irradiation micro-ondes a permis la synthèse de nouveaux produits substitués en position 4 par différents groupements aryle ou styryle. Dans un second temps, la réactivité LD-SRN1 a été étudiée entre le 4-[4-(chlorométhyl)phényl]-1,2-diméthyl-5-nitro-1H-imidazole et différents nucléophiles centrés sur l'atome de carbone ou de soufre. Cette étude a révélé l'importance de la température dans l'activation de la réaction par transfert monoélectronique. De nouveaux dérivés substitués en position 4 par divers groupements sulfonyles ont ensuite été synthétisés, par réactions SN2 et SNAr entre des dérivés 5-nitroimidazolés et différents anions sulfinates. Cette synthèse a été suivie par la mise au point de tests biologiques sur Trichomonas vaginalis. L'activité trichomonacide a été évaluée sur certaines de ces molécules, à l'origine de relations structure-activité montrant l'influence de la position du groupement sulfonyle substituant le noyau 5-nitroimidazole. La dernière partie de ce travail décrit une réaction de O-arylation pallado-catalysée inattendue et originale, d'un dérivé fluoré en série nitro(o-nitrophényl)imidazole impliquant des acides arylboroniques dans les conditions opératoires de la réaction de Suzuki-Miyaura. / The aim of this work consists of the synthesis of new potentially bioactive functionalized 5-nitroimidazoles. Initially, the reactivity study of the 4-bromo-1,2-dimethyl-5-nitro-1H-imidazole under microwave-assisted Suzuki-Miyaura cross-coupling conditions gave new derivatives substituted by various aryl or styryl groups in 4-position. In a second step the 4-[4-(chloromethyl)phenyl]-1,2-dimethyl-5-nitro-1H-imidazole was prepared in order to study LD-SRN1 reactivity with different carbon and sulphur centered nucleophiles. This study pointed the role of the temperature for the electron transfer reactions. Then, new 4-position sulfonyl substituted derivatives were synthesized by SN2 and SNAr reactions between sulfinate anions and three substrates in 5-nitroimidazole series. This synthesis was followed by the development of biological assays on Trichomonas vaginalis. This assay was performed on some of these molecules, which revealed a relation between the structure and the position of the sulfonyl group and the antitrichomonas activity. The last part of this work describes an unexpected and original palladium-catalyzed O-arylation in fluorinated nitro(o-nitrophenyl)imidazole series involving arylboronic acids under Suzuki-Miyaura cross-coupling reaction conditions.
83

Hydrogels thermosensibles et mucoadhésifs : nouvelles stratégies pour prévenir et traiter les pathogènes au niveau de la muqueuse vaginale / Thermosensitive and mucoadhesive hydrogels : new strategies for preventing and treating the disease at the vaginal mucosa

Pradines, Bénédicte 02 July 2014 (has links)
Selon les dernières estimations de l'OMS, on enregistre chaque année dans le monde 498.9 millions de nouveaux cas d'infections sexuellement transmissibles (IST) dont 276.4 millions sont dus au parasite Trichomonas vaginalis (T. vaginalis). Au niveau du tractus génital, la colonisation et l’irritation de la muqueuse vaginale par T. vaginalis favorisent la survenue de complications infectieuses. Ces infections associées peuvent conduire à des infections chroniques et avoir à terme des conséquences graves (stérilité, rupture prématuré du placenta, mort prématurée du nourrisson). De plus, ces infections vaginales représentent des facteurs qui favorisent les infections par le Virus d’Immunodéficience Humaine (VIH-1).A l’heure actuelle, la lutte contre ce type d’infections consiste à agir tant au niveau curatif, que préventif. Ainsi, l’objectif de ce projet est de développer de nouvelles formulations pour la prévention et le traitement des pathogènes qui colonisent les muqueuses vaginales. Dans ce contexte, la formulation que nous proposons est composée de metronidazole inclut dans un hydrogel thermogélifiant à base de pluronic® F127 et de chitosane. Il a été montré que cet hydrogel conserve ces propriétés physiques à une température physiologique même après dilution dans les fluides vaginaux. Ces hydrogels sont stables et permettent une libération prolongée du metronidazole. La formulation n’a montré aucune toxicité envers les cellules HeLa ni envers la muqueuse vaginale porcine. L’efficacité de cette formulation a été prouvée envers T. vaginalis et présente un effet protecteur envers les cellules HeLa en présence de T. vaginalis. L’ensemble des résultats suggère donc la capacité́ de cette formulation à constituer une double barrière, physique et pharmacologique, protectrice de la muqueuse vaginale vis-à-vis de T. vaginalis. / According to the latest WHO estimates, 498 millions of new cases of sexually transmitted infections (STIs) are recorded annually in the world, including 276.4 million due to the parasite Trichomonas vaginalis (T. vaginalis). In the genital tract colonization and irritation of the vaginal mucosa by T. vaginalis promote the occurrence of infectious complications. Associated infections can lead to chronic infections and eventually have serious consequences (infertility, premature placental abruption, premature death). In addition, these vaginal infections can promote infection by Human Immunodeficiency Virus (HIV-1).Currently, the fight against these infections is to act at curative and preventive level. Thus, the objective of this project is to develop new formulations for the prevention and treatment of pathogens that colonize the vaginal mucosa. In this context, we propose a formulation composed of metronidazole and chitosan include in a thermogelling hydrogel of pluronic F127®.It was shown that the hydrogel retains its physical properties even at a physiological temperature and after dilution in the vaginal fluids. These hydrogels are stable and allow a sustained release of the metronidazole. The formulation showed no toxicity against HeLa cells or porcine vaginal mucosa. The effectiveness of this formulation has been proven against T vaginalis and has a protective effect on HeLa cells in the presence of T. vaginalis. The overall results therefore suggest the ability of this formulation to form a double barrier, physical and pharmacological, than protect vaginal mucosa against T. vaginalis.
84

Synthèse et évaluation biologique de nouveaux nitroimidazoles : challenges et recherche de nouvelles relations structure-activité / Synthesis and biological evaluation of new nitroimidazoles : challenges and search for new structure-activity relationships

Mathias, Fanny 14 December 2017 (has links)
Ce travail de thèse est consacré à la synthèse et l’évaluation biologique de nouveaux nitromidazoles à potentialités anti-infectieuses. Dans les trois premiers chapitres, nous avons abordé les propriétés biologiques des 5-nitroimidazoles, et la synthèse de nouveaux composés fonctionnalisés en positions 2 et 4 dans le but d'améliorer l'activité sur les souches résistantes au métronidazole, le 5-nitroimidazole de référence, tout en contrôlant au mieux la mutagénicité. Nous avons développé une méthode de couplage régiosélectif de Suzuki-Miyaura en position 4 du 2,4-dibromo-1-méthyl-5-nitro-1H-imidazole, suivi d’un deuxième couplage de Suzuki-Miyaura ou de Sonogashira par méthodologie « one-pot » séquentielle en position 2. Cette méthodologie nous a permis d’obtenir 30 nouveaux composés qui ont été testés pour leur propriétés antibactériennes et antiparasitaires. Une dizaine de composés ont été synthétisés par méthodologie TDAE sur le 4-[4-(chlorométhyl)phényl]-1,2-diméthyl-5-nitro-1H-imidazole. Dans le dernier chapitre, nous avons initié un travail de pharmacomodulation en série imidazooxazole, motif bien connu pour ses propriétés antituberculeuses et antileishmaniennes. Nous avons présenté la synthèse et l’évaluation biologique de dérivés 5-nitroimidazooxazoles et 7-nitro-2,3-dihydroimidazo[5,1-b]oxazoles. La synthèse de dérivés 6-nitroimidazooxazoles fonctionnalisés en position 5 est en cours de développement et nous avons présenté quelques essais de CH-arylation sur le 2-méthyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazole. / We have developed in this work the synthesis and the biological evaluation of novel nitromidazoles with anti-infectious potentialities. In the first three parts, we discussed the biological properties of 5-nitroimidazole scaffold, and the synthesis of new compounds functionalized at 2- and 4-position in order to improve the activity on metronidazole-resistant strains, while controlling mutagenicity. We developed a regioselective Suzuki-Miyaura cross- coupling reaction at 4-position of 2,4-dibromo-1-methyl-5-nitro-1H-imidazole, followed by a second Suzuki-Miyaura or Sonogashira cross-coupling reaction at 2-position by a "one-pot" sequential process. This methodology has enabled us to obtain 30 new products which were tested for their antibacterial and antiparasitic properties. Twelve compounds were synthesized by TDAE methodology on {4- [4- (chloromethyl) phenyl]} -1,2-dimethyl-5-nitro-1H-imidazole. In the last part, we initiated a work of pharmacomodulation in imidazooxazole series, scaffold well-known for its antituberculous and antileishmanial properties. We have described the synthesis and the biological evaluation of 6-functionalized 5-nitroimidazooxazole and 7-nitro-2,3-dihydroimidazo [5,1-b]oxazole derivatives. We have presented some CH-arylation assays on 2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazole to obtain 5-functionalized 6-nitroimidazooxazole derivatives.
85

Probiotika som prevention mot urogenitala sjukdomar

Hedman, Ellinore January 2014 (has links)
About 10 % of the adult women population in Sweden are treated annually for urinary tract infections. The increasing bacterial resistance towards antibiotics is classified by WHO (World Health Organization) and ECDC (European Centre for Disease Prevention and Control) as one of the greatest treats for human health in a global perspective. To find alternatives scientists are studying the possibility to use probiotics to reduce the frequency of recurring urinary tract infections. This literature study examines five randomized double blinded placebo controlled studies where different strains of Lactobacillus have been used as a prophylactic to women suffering from recurrent urinary tract infections and bacterial vaginosis. Overall the studies do not display enough promising results to recommend the use of probiotics as a prophylax or cure.
86

Charakterizace železo-sirných flavoproteinů z hydrogenosomu Trichomonas vaginalis / Characterization of hydrogenosomal iron-sulfur flavoproteins from Trichomonas vaginalis

Pilařová, Kateřina January 2012 (has links)
Trichomonas vaginalis is flagelated microaerophilic protozoan parasite from Excavata group, which causes trichomoniasis, the most common nonviral sexually transmitted disease in the world. It causes vaginitis in women and uretritis in man and it can also cause problems for example during pregnancy. This thesis is aimed on the characterisation of hydrogenosomal iron-sulfur flavoproteins (ISF) from Trichomonas vaginalis, proteins, which were only recently discovered in the proteome of hydrogenosome of T. vaginalis. Specifically, we have focused on characterisation of ISF3 which is, according to our data, active homodimer and binds flavin mononucleotide (FMN) and iron-sulphur centre in its active site. The iron- sulphur centre is not characterised yet. ISF3 is able to reduce oxygen, hydrogen peroxide, sodium nitrate and metronidazole also in the enzymatic system with PFO and ferredoxin. Next, I tried to reduce ammonium sulphate with ISF3, but unsuccessfully. These results correspond with the activities obtained for ISF from Methanosarcina thermophila, where ISF reduces oxygen and hydrogen peroxide to water. In addition, ISF3 is able to reduce nitrogen compounds. It is important according to the fact, that metronidazole is a drug from the group of 5−nitroimidazoles. The other results show the decrease...
87

Vaccination of BALB/c Mice with an Alhydrogel Adjuvanted Whole Cell Trichomonas vaginalis Formulation

Smith, Jeffrey D. 14 January 2014 (has links)
A human safe, Alhydrogel adjuvanted whole cell Trichomonas vaginalis vaccine was tested for efficacy in a BALB/c mouse model of vaginal infection. Additionally, the systemic and local immune response were measured. Vaccination reduced incidence and increased clearance of infection, and induced both systemic and local humoral immune responses. CD4+ cells were detected in vaginal tissues following intravaginal challenge with T. vaginalis, but were not seen in uninfected mice. CD4+ cells were detected more often, earlier, and in greater numbers in vaccinated vaginal tissues compared to unvaccinated controls. Presence of CD4+ T cells following infection can have significant implications of increasing HIV susceptibility and transmission. These data suggest that the vaccine induces local and systemic immune responses, and confers significantly greater protection against vaginal challenge than unvaccinated vaginal challenge. These data support the potential for a human vaccine against T. vaginalis infection that could also impact the incidence of HIV infections.
88

Diversidade bacteriana e determinação da carga de Gardnerella vaginalis, Atopobium vaginae, Mobiluncus spp., Mycoplasma hominis e Lactobacillus spp. em amostras de secreção vaginal de mulheres com e sem diagnóstico clínico de vaginose bacteriana

Oliveira, Laura Maria Andrade de 17 February 2014 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-02-15T16:46:49Z No. of bitstreams: 1 lauramariaandradedeoliveira.pdf: 1852262 bytes, checksum: 703240e1ddc07fe9a86ba010f803bbcc (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-02-26T12:26:34Z (GMT) No. of bitstreams: 1 lauramariaandradedeoliveira.pdf: 1852262 bytes, checksum: 703240e1ddc07fe9a86ba010f803bbcc (MD5) / Made available in DSpace on 2016-02-26T12:26:34Z (GMT). No. of bitstreams: 1 lauramariaandradedeoliveira.pdf: 1852262 bytes, checksum: 703240e1ddc07fe9a86ba010f803bbcc (MD5) Previous issue date: 2014-02-17 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A microbiota vaginal é considerada um ambiente complexo, onde várias espécies bacterianas coexistem e desenvolvem complexas relações. Vaginose bacteriana (VB) é uma síndrome caracterizada por uma depleção de espécies de Lactobacillus predominantes na microbiota vaginal saudável e um aumento de outras espécies, principalmente Gardnerella vaginalis e Atopobium vaginae. O objetivo desse trabalho foi avaliar a microbiota vaginal de pacientes com e sem VB, atendidas no serviço de ginecologia do SUS e da rede privada de Juiz de Fora/MG, quanto a sua diversidade bacteriana e quantificar os principais gêneros e espécies envolvidos na patogênese da doença. Secreção vaginal de pacientes com e sem VB foram coletadas e transportadas para o laboratório, em meio específico. Lâminas foram coradas pelo método de Gram, a fim de estabelecer o escore de Nugent para avaliação das pacientes entre saudáveis e doentes. O DNA total das secreções foi extraído e PCR quantitativa (qPCR) em tempo real foi realizada, utilizando primers específicos para Lactobacillus spp., G. vaginalis, A. vaginae, Mobiluncus spp. e Mycoplasma hominis. A partir do DNA total extraído também foi realizada PCR convencional utilizando primers específicos para Domínio Bacteria e os filos Actinobacteria e Firmicutes, e em seguida foi realizada técnica de Eletroforese em Gel com Gradiente Desnaturante (DGGE). Foi realizada também a técnica de Hibridização Fluorescente in situ (FISH), para identificação e quantificação de bactérias pertencentes aos filos Actinobacteria, Firmicutes, α-Proteobactéria, β-Proteobactéria e γ-Proteobactéria. Entre os grupos saudável e doente (VB) foi observada diferença estatisticamente significativa na quantificação de Lactobacillus spp., G. vaginalis, A. vaginae, Mobiluncus spp. e M. hominis. Lactobacillus spp. esteve presente em maior concentração no grupo saudável enquanto que G. vaginalis, A. vaginae, Mobiluncus spp. e M. hominis estiveram presentes em maior concentração no grupo doente (VB). De um modo geral, a concentração de G. vaginalis e Mobiluncus spp. elevou-se com o aumento do escore de Nugent; em contrapartida, a concentração de Lactobacillus spp., decresceu com o aumento do escore de Nugent. A análise de agrupamento mostrou que, com algumas exceções, os perfis de pacientes apresentando o mesmo status de saúde tenderam a se agrupar juntos, porém em clusters separados e que os agrupamentos parecem ser regidos pelo status de saúde das pacientes. As variáveis riqueza e diversidade revelaram perfis complexos entre as amostras e a análise de componente principal (PCA) mostrou que as amostras dentro do grupo VB tenderam a se agrupar na análise dos filos Actinobacteria e Firmicutes. Não foi observada diferença estatisticamente significativa entre os grupos saudável e doente (VB) em relação a quantificação dos filos Actinobacteria, Firmicutes, α-Proteobactéria, β-Proteobactéria e γ-Proteobactéria. O uso combinado das técnicas DGGE, FISH e PCR quantitativa em tempo real representam uma estratégia bem sucedida para o monitoramento qualitativo e quantitativo de alterações na microbiota vaginal relacionadas a doenças infecciosas, como a vaginose bacteriana. Tal fato pode contribuir tanto para o desenvolvimento de ferramentas que auxiliem no diagnóstico de mulheres acometidas pela VB, especialmente as pacientes assintomáticas, e também pode contribuir com a melhoria e otimização dos regimes terapêuticos adotados na prática clínica para o tratamento da VB. / The vaginal microbiota is considered a complex environment where several bacterial species coexist and develop complex relationships. Bacterial vaginosis (BV) is a syndrome characterized by a depletion of Lactobacillus species prevalent in healthy vaginal microbiota and an increase in other species, especially Gardnerella vaginalis and Atopobium vaginae. The aim of this study was to evaluate the vaginal microbiota of patients with and without BV, attended at the gynecology service of the SUS and the private service of health of Juiz de Fora/MG, as its bacterial diversity and quantify the major genera and species involved in the disease pathogenesis. Vaginal secretions of patients with and without BV were collected and transported to the laboratory in a specific medium. Slides were stained by the Gram method in order to establish the Nugent Score for evaluation of patients between healthy and sick. The total DNA of secretions was extracted and Real-time Polymerase Chain Reaction (qPCR) was performed using specific primers for Lactobacillus spp., G. vaginalis, A. vaginae, Mobiluncus spp. and Mycoplasma hominis. From the total DNA extracted from conventional PCR also was performed using specific primers to Bacteria domain and Actinobacteria and Firmicutes phyla, and then Denaturing Gradient Gel Electrophoresis (DGGE) was performed. The identification and quantification of bacteria belonging to the phyla Actinobacteria, Firmicutes, α-Proteobacteria, β-Proteobacteria and γ-Proteobacteria were performed by the technique of Fluorescence in situ Hybridization (FISH). Among the healthy and diseased (VB) groups statistically significant difference was observed in the quantification of Lactobacillus spp., G. vaginalis, A. vaginae, Mobiluncus spp. and M. hominis. Lactobacillus spp. was present in higher concentration in the healthy group while G. vaginalis, A. vaginae, Mobiluncus spp. and M. hominis were present in higher concentrations in the patient group (VB). In general, the concentration of G. vaginalis, and Mobiluncus spp. increased with the increment in the Nugent Score; however, the concentration of Lactobacillus spp decreased with the raise of the Nugent score. The cluster analyses showed that, with few exceptions, the profiles from patients with the same health status grouped together in separate clusters and there was a distinct separation based on the health status of the patients. The richness and diversity showed complex profiles and principal component analysis (PCA) showed that the samples within the VB group grouped together on the analysis of the phyla Firmicutes and Actinobacteria. No statistically significant difference was observed between healthy and diseased groups (VB) for quantification of the phyla Actinobacteria, Firmicutes, α-Proteobacteria, β-Proteobacteria and γ-Proteobacteria. The combined use of techniques DGGE, FISH and real-time quantitative PCR represent a successful strategy for qualitative and quantitative monitoring of changes in vaginal microbiota related to infectious diseases such as Bacterial Vaginosis.This may contribute to both the development of tools that aid in the diagnosis of women affected by BV, especially asymptomatic patients, and may also contribute to the improvement and optimization of therapeutic regimes adopted in clinical practice for the treatment of BV.
89

Vaccination of BALB/c Mice with an Alhydrogel Adjuvanted Whole Cell Trichomonas vaginalis Formulation

Smith, Jeffrey D. January 2014 (has links)
A human safe, Alhydrogel adjuvanted whole cell Trichomonas vaginalis vaccine was tested for efficacy in a BALB/c mouse model of vaginal infection. Additionally, the systemic and local immune response were measured. Vaccination reduced incidence and increased clearance of infection, and induced both systemic and local humoral immune responses. CD4+ cells were detected in vaginal tissues following intravaginal challenge with T. vaginalis, but were not seen in uninfected mice. CD4+ cells were detected more often, earlier, and in greater numbers in vaccinated vaginal tissues compared to unvaccinated controls. Presence of CD4+ T cells following infection can have significant implications of increasing HIV susceptibility and transmission. These data suggest that the vaccine induces local and systemic immune responses, and confers significantly greater protection against vaginal challenge than unvaccinated vaginal challenge. These data support the potential for a human vaccine against T. vaginalis infection that could also impact the incidence of HIV infections.
90

Novel Facets of Heat Shock Protein 90 in Neglected Protozoan Parasites

Singh, Meetali January 2016 (has links)
No description available.

Page generated in 0.0636 seconds