• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 49
  • 10
  • 7
  • 6
  • 4
  • 4
  • 3
  • 3
  • 2
  • 2
  • 2
  • Tagged with
  • 121
  • 27
  • 22
  • 19
  • 19
  • 19
  • 15
  • 15
  • 14
  • 14
  • 12
  • 11
  • 10
  • 10
  • 10
  • 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.
51

Discovery and characterisation of the novel, pathological GNB3 mutation (D153del/Gβ3D), in the retinopathy globe enlarged (rge) chicken

Tummala, Hemanth January 2008 (has links)
The common human GNB3 825C > T variant, which is present in 50% of the world’s chromosomes, has previously been shown to predispose individuals to hypertension, cardiac and neural disorders. This variant causes the production of a stable and gain of function protein Gβ<sub>3S</sub>- This thesis describes the discovery of a novel D153del mutation that produces an unstable, loss of function, protein Gβ<sub>3D </sub> in the recessively inherited, retinopathy globe enlarged (rge) chickens. This thesis also demonstrates that the normal Gβ<sub>3</sub> downstream phosphorylation signalling pathways are significantly altered in a tissue specific manner in rge chicken organs and in a human GNB3 825TT lymphoblast cell line. In rge tissues expressing Gβ<sub>3D</sub> protein, the cAMP induced GRK2 phosphorylation activity is significantly altered. Moreover MAPK1 (ERK2) phosphorylation is significantly decreased compared to normal tissues. In contrast human 825TT cell lines expressing the Gβ<sub>3S</sub> protein, showed enhanced cAMP induced GRK2 and MAPK (ERK1 and ERK2) phosphorylation activity. These results confirm previous findings of 825C > T Gβ<sub>3</sub> studies, that Gβ<sub>3S</sub> is indeed a hyper-activating structural variant, in contrast to the D153del Gp3D is a classical recessively inherited non-functional mutation.
52

Hodnocení transfekce nukleových kyselin v in vitro podmínkách. / IN VITRO assays for investigating nucleic acid delivery.

Mihaličoková, Dajana January 2018 (has links)
Charles University, Faculty of Pharmacy in Hradec Králové, Department of Biochemical Sciences University of Vienna, Faculty center for Pharmacy, Department of Pharmaceutical Chemistry, Laboratory of MacroMolecular Cancer Therapeutics Candidate: Dajana Mihaličoková Supervisor (Charles University): PharmDr. Anna Jirkovská, Ph.D. Supervisor (University of Vienna): Univ.Prof. Dipl. Ing. Dr. Manfred Ogris Co-supervisor (University of Vienna): Dr. Haider Sami, Ph.D. Title of diploma thesis: In vitro assays for investigating nucleic acid assay Keywords: transfection, splice correction, BCA assay, polyplexes One of the most important tasks of biochemical research is to find out the right way how to cure cancer, genetic disorders and other illnesses which are still not curable. Towards this, gene therapy is emerging as a potential treatment owing to its ability to deliver genetic material inside the cell. Reporer gene based transfection process can be used to study gene expression. Transfection is mediated by vectors, either of viral or non-viral origin. Non-viral vectors offer several advantages over the viral counterparts like easier to synthesize, relatively cheap and the most important is their non-immunogenicity. Cationic polymers based on polyethylenimine form complexes with plasmid DNA reffered to as...
53

Caracterização molecular (PCR) e infecção de Metarhizium anisopliae var. acridum e Metarhizium anisopliae em Zaprionus indianus

LEÃO, Mariele Porto Carneiro January 2006 (has links)
Made available in DSpace on 2014-06-12T15:05:47Z (GMT). No. of bitstreams: 2 arquivo4602_1.pdf: 941507 bytes, checksum: c0ae7f823963e2cbd711e367c4dd1d23 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2006 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Foram analisadas as linhagens Metahizium anisopliae var. acridum e Metarhizium anisopliae var. anisopliae quanto à patogênicidade sobre Zaprinus indianus, utilizando as concentrações 104, 105, 106, 107, 108 conídios/mL considerando o percentual de emergência de adultos. De acordo com a metodologia empregada verificou-se que as duas linhagens apresentaram ação contra Z. indianus. Os marcadores moleculares ITS (Internal Trancride Spacer) do rDNA, Intron Splice Site Primer e Microssatélite (SSR- Simple Sequence Repeats), foram utilizados para avaliar a diversidade genética entre as linhagens antes e após a passagem pela mosca. A análise de agrupamento usando o método de UPGMA baseada nas distâncias genéticas dos marcadores moleculares confirmou a diversidade genética reconhecida no gênero Metarhizium. O microssatélite (GTG)5 e o intron do grupo mRNA nuclear tiveram a mesma sensibilidade em detectar a variabilidade genética entre as linhagens de Metarhizium . Os produtos de amplificação dos loci ITS1-5.8-ITS2 do rDNA com os iniciadores ITS4 e ITS5 foram eficientes em demonstrar que as linhagens estudadas pertence à espécie Metarhizium anisopliae, apesar da diversidade genética demonstrada pelos marcadores (GTG)5 e EI1. Os perfis de amplificações da região microssatélite, intron e ITS após a passagem por Z. indianus comprovaram que as linhagens reisoladas foram às mesmas que foram utilizadas para infectar
54

Caracterização molecular de espécies deMetarhizium e patogenicidade sobre Diatraeasaccharalis

LIMA, Maria do Livramento Ferreira January 2005 (has links)
Made available in DSpace on 2014-06-12T15:03:44Z (GMT). No. of bitstreams: 2 arquivo4555_1.pdf: 1910369 bytes, checksum: 5a0109c9538c737e8440a1c2af5b2757 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2005 / Foram analisadas 15 linhagens de Metarhizium isoladas de diferentes regiões e hospedeiros quanto às características genéticas e 7 linhagens quanto a patogenicidade sobre Diatraea saccharalis. Os marcadores moleculares ITS (Internal Transcrided Spacer) do rDNA, Intron splice site primer, RAPD e Microssatélites (SSR-Simple Sequence Repeats) foram utilizados para avaliar a diversidade genética entre as linhagens. A análise de agrupamento usando o método UPGMA baseada nas distâncias genéticas dos quatro marcadores moleculares confirmou a diversidade genética reconhecida no gênero Metarhizium. As enzimas de restrição, HaeIII e MspI, evidenciaram a diversidade genética entre as linhagens ao digerirem os produtos de amplificação do locus ITS1-5.8S-ITS2 do rDNA com os iniciadores ITS4 e ITS5, a enzima DraI não apresentou sítios de restrição. Os introns do grupo mRNA nuclear discriminaram as linhagens de Metarhizium apenas com a utilização do iniciador EI1. As técnicas de RAPD e regiões de Microssatélite foram eficientes em demonstrar a diversidade entre as linhagens. Porém o microssatélite (GACA)4 foi mais sensível em detectar a variabilidade intra e interespecífica entre as diferentes linhagens de Metarhizium. Não houve correlação entre grupos e regiões geográficas. As linhagens 4415, 4400 e 4897 causaram maior percentual de mortalidade das larvas de Diatraea saccharalis. Também não houve correlação entre os agrupamentos gerados pelas técnicas moleculares e percentual de mortalidade de larvas de D. saccharalis
55

Análise da diversidade genética através de marcadores moleculares e características citomorfológicas de Colletotrichum gloeosporioides

SOUSA, Adna Cristina Barbosa de January 2004 (has links)
Made available in DSpace on 2014-06-12T15:04:33Z (GMT). No. of bitstreams: 2 arquivo4458_1.pdf: 786506 bytes, checksum: 30ccb6ed2c83e0fa52dedbb745159fb1 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2004 / Foram analisadas 20 linhagens de C. gloeosporioides quanto às características genéticas e citomorfológicas. Os marcadores moleculares, RAPD, microssatélites, Intron Spice Site Primer e região ITS do DNA ribossomal, foram utilizados para avaliar a diversidade genética entre as linhagens. A análise de agrupamento através do método UPGMA confirmou a diversidade genética intraespecífica reconhecida em C. gloeosporioides. Com a técnica de RAPD foi detectada uma maior similaridade genética entre as linhagens. As regiões de microssatélites investigadas, demonstraram alto polimorfismo genético e os introns discriminaram todos as linhagens apenas com o primer (EI-1), e revelaram maior diversidade genética em relação aos outros marcadores moleculares utilizados. As três enzimas de restrição testadas, HaeIII, DraI e MspI evidenciaram a diversidade genética entre as linhagens nos produtos de amplificação dos loci ITS1-5.8S-ITS2 do rDNA com os primers ITS1 e ITS4. Todos os marcadores empregados, foram eficientes em demonstrar o alto grau de polimorfismo genético, constatado pela formação de grupos altamente diversificados, sem apresentar correlação entre os hospedeiros. Os aspectos macroscópicos exibiram uma variação na coloração, textura e segregação de setores nas colônias, e as observações microscópicas demonstraram a formação de estruturas vegetativas e reprodutivas peculiares da espécie. A condição nuclear investigada através da técnica de HCl-Giemsa, evidenciou conídios 100% uninucleados
56

Implication de SOX9 et de MiniSOX9 dans la tumorigenèse colorectale / SOX9 and MiniSOX9 in intestinal tumorigenesis

Rammah-Bouazza, Cyrine 13 December 2012 (has links)
SOX9 est un facteur de transcription, appartenant à la famille des protéines à domaine HMG, et connu pour réguler la transcription grâce à la liaison de ce domaine à l'ADN. Au laboratoire, il a été montré que SOX9 possédait des propriétés anti-oncogéniques, cependant, de façon paradoxale, SOX9 est surexprimé dans les tumeurs colorectales. Nous avons mis en évidence l'existence d'un nouveau variant d'épissage de SOX9, MiniSOX9, qui possède un effet dominant négatif vis-à-vis de l'activité transcriptionnelle de SOX9. MiniSOX9 est fortement exprimé dans les tumeurs en comparaison avec le tissu sain adjacent à la tumeur. Nous avons émis l'hypothèse que MiniSOX9 pourrait donc avoir, dans les tumeurs, un effet antagoniste à SOX9 et s'opposer à ses propriétés anti-oncogéniques. Grâce à la mise en place de modèles cellulaires tumoraux de surexpression de SOX9 et MiniSOX9, inductibles à la doxycycline, nous avons mis en évidence que SOX9 réduit la prolifération, la migration et l'invasion cellulaire. De manière surprenante, MiniSOX9 ne possède aucun effet sur la prolifération cellulaire, suggérant que les effets de SOX9 pourraient être dus à son activité transcriptionnelle. En revanche, SOX9 ainsi que MiniSOX9 réduisent la capacité clonale des cellules et leur capacité à former des tumorosphères. Dans ce cas, il serait probable que SOX9 et MiniSOX9 modulent l'activité de protéines partenaires / SOX9 is an HMG transcription factor known to regulate transcription by binding of its HMG domain to DNA. We previously demonstrated that SOX9 has anti-oncogenic-properties but SOX9 is overexpressed in colon tumors when compared to adjacent healthy tissu. This overexpression appears paradoxical, unless its anti-oncogenic activity cannot be exert. In this study, we report the discovery of MiniSOX9, a new SOX9 splice variant, which is highly expressed in colon tumors. MiniSOX9 acts as a SOX9 dominant negative isoform. Our hypothesis was that MiniSOX9 antagonizes the SOX9 anti-oncogenic activity in tumors.Using tumors cells lines inducible for SOX9 and MiniSOX9 overexpression, we showed that SOX9 reduces cell proliferation, migration and invasion. Surprisingly, MiniSOX9 has no effect on cell proliferation, suggesting that SOX9 effects could be du to his transcriptionnal activity. However, SOX9 and MiniSOX9 decrease cell clonal ability and tumorosphere formation. In this case, it is likely that SOX9 and MiniSOX9 modulate the activity of proteins partners.
57

Luteinizing hormone receptor:expression and post-translational regulation of the rat receptor and its ectodomain splice variant

Apaja, P. (Pirjo) 16 November 2005 (has links)
Abstract The luteinizing hormone receptor (LHR) is a G protein-coupled receptor (GPCR) that has a large N-terminal ligand binding ectodomain. The LHR ectodomain splice variant, expressed concomitantly with the full-length LHR in tissues, has an unknown biological function. GPCRs are a major pharmacological target, however, very little is known about the intracellular regulation of these receptors. In the present work, expression and maturation of the rat LHR and its variant were elucidated using both tissues and heterologous expression systems. A special effort was made to identify the role of developmental stage and tissue type on the LHR maturation and to find out about the molecular role of the ectodomain splice variant. We found two sites of localization for the receptor, namely the sensory system and urogenital tissues. This was demonstrated at mRNA and protein level and by rat LHR promoter-driven β-galactosidase (β-Gal) expression in the mice. In neurons, the β-Gal co-localized with the cytochrome P450 side chain cleavage enzyme, which may indicate a novel role in the neurosteroid synthesis. The neuronal LHR was expressed in the mature and immature protein forms in both developing and adult tissues, being able to bind hormone with similar high-affinity as gonadal receptors. In contrast, only immature receptors were detected in the fetal rat urogenital structures. A significant novel finding was substantial upregulation of the LHR in pregnant female rat adrenal glands and kidneys at a time that coincides with the differentiation of the fetal urogenital tissues. The mice overexpressing the ectodomain splice variant showed interference in pituitary-gonadal functions and morphological changes in the urogenital tissues. The studies showed that the variant was an endoplasmic reticulum (ER)-retained soluble protein. It accumulated in juxtanuclear regions of the ER together with ER folding chaperones and was a substrate for ER associated degradation (ERAD). The co-expression of the variant with the full-length receptor decreased the amount of receptors and misrouted them to the juxtanuclear ER subcompartment. Taken together, we suggest that the maturation of the LHR protein is developmentally and physiologically regulated at the post-translational level in tissues. The LHR ectodomain splice variant possibly modulates post-translationally the number of full-length receptors through physiological signals. Our observation of the chaperone and protein accumulation into a specific ER subcompartment may represent a protein quality control holding compartment for inefficiently/misfolded ERAD substrates.
58

P2X7R-driven IL-1 responses in differentiated murine dendritic cells : comparison with macrophages

Englezou, Pavlos January 2013 (has links)
The P2X7R is a functionally distinct member of the P2X non-selective cation channels and has been implicated in the initiation of immune responses. One of the most extensively characterised immune responses of the receptor is to signal the rapid aggregation of the inflammasome complex and signal the release of IL-1β. These investigations have focused in providing direct comparisons of P2X7R-driven IL-1 responses between DC and mouse macrophages (peritoneal macrophages [PMΦ] and bone marrow derived macrophages [BM-MΦ]). Expression of the P2X7R has been identified in all three populations both at the transcriptional (P2X7A variant) and protein levels. Activation with lipopolysaccharide (LPS) (2h) induced a rapid dose dependent release of IL-6 but not of IL-1β in BM-DC. Rapid (2h) IL-1β release required both LPS priming and ATP activation. Both signals were also required for IL- 1β release in mouse ΒΜ-ΜΦ and PMΦ, however, at comparatively markedly lower levels. Furthermore, like with IL-1β, LPS did not induce IL-1α release in BM-DC. Interestingly, subsequent challenge with ATP evoked IL-1α release in BM-DC alone, with little or no detectable levels observed in activated BM-MΦ. This rapid IL-1β release (but not IL-6) was potently inhibited in both macrophages and DC with a P2X7R-specific inhibitor (A-740003) providing evidence that is predominantly a P2X7R-driven process. Treatment with A-740003 also potently inhibited IL-1α release from BM-DC suggesting that the ATP-P2X7R and caspase-1 activation might have a role in the release of the cytokine. Expression of gain-of-function P2X7K and loss-of- function P2X7J splice variants has been identified in both BM-DC and BM-MΦ, at the level of transcription. The possibility that a differential baseline or LPS-induced expression (at the transcriptional level) of P2X7J and P2X7K variants accounts for the diverse cytokine responses observed in BM-DC and BM-MΦ was also explored. However, the levels of expression for the various splice variants of interest (P2X7K and P2X7J) were found to be similar between the two cell types. The results of these investigations identify some subtle but intriguing differences in the mechanism of P2X7R activation and IL-1 release between DCs and macrophages. Purinergic signalling is increasing being implicated in the regulation of immune responses both in potentiating or suppressing inflammation. However, further work is required to decipher how the dynamic interplay between different purines can influence the immune activation of different cell types and indeed different cell subsets.
59

Phytomonas e outros Tripanossomatídeos em insetos no Estado de Rondônia - Amazônia Ocidental. / Phytomonas and others Trypanosomatids of insects in Rondonia State, Occidental Amazon.

Mara Maria Izar de Maio Godoi 15 March 2001 (has links)
Tripanossomatídeos particularmente os do gênero Phytomonas, podem infectar, frutos, látex, seiva, floema e flores de muitas famílias de vegetais, e foram detectados em insetos fitófagos de seus possíveis vetores em várias regiões do Velho e Novo Continente. Em contraste com a enorme variedade da flora e da fauna entomológica da Amazônia Brasileira, poucas espécies têm sido descritas albergando tripanossomatídeos. Os tripanossomatídeos pertencentes a estes gêneros podem apresentar formas evolutivas típicas que permitem a sua identificação morfológica. No entanto as formas promastigota, existentes tanto no ciclo evolutivo dos gêneros Herpetomonas, Leptomonas e Phytomonas, não permitem a identificação morfológica, sendo necessário parâmetros adicionais para a diferenciação entre os gêneros. A dificuldade do cultivo “in vitro”, impede a correta avaliação da presença destes parasitas em insetos e plantas, impossibilitando uma avaliação do universo dos tripanossomatídeos. No presente trabalho foram realizadas 37 coletas de hemípteros adultos, no estado de Rondônia, nas duas estações climáticas regional durante o período de 1998 a 1999. Foram coletados 244 hemípteros pertencentes a 17 espécies diferentes as quais 13 se revelaram portadoras de tripanossomatídeos. Das amostras positivas foram feitos esfregaços em lâminas e corados com Giemsa para posterior análise morfológica e morfométrica. Numa segunda etapa fizemos aplicação do PCR (reação em cadeia da Polimerase) em DNA recuperado de esfregaços em lâminas para pesquisa de tripanossomatídeos de insetos e plantas seguido de hibridação com sonda SL3’ específica para pesquisa do gênero Phytomonas, com vistas a um estudo preliminar da presença de tripanossomatídeos e Phytomonas em Hemípteros Fitófagos no estado de Rondônia sem necessidade de isolamento e cultura axênica dos parasitas. / Tripanossomatids, particularly Phytomonas, may infect the fruit, latex, sap, phloem and flowers of many plant families. These parasites have also been detected in phytofagous insects which are potential vectors in many areas of the Old and New World. In spite of the enormous variety of flora and entomological fauna of the Brazilian Amazon only a few species have been described harbouring tripanossomatids. Some genera of tripanossomatids present typical morphological forms which they can be identified. However, the promastigote form occurs in the genera Herpetomonas, Leptomonas and Phytomonas, so other parameters are needed to separate them. The difficulties of in vitro cultivation also hinders determining the presence of these parasites in both insects and plants, thus making it impossible to estabilish realistic incidence rates of these ubiquitous parasites. In the present study 37collections of adult hemipterans were made in Rondônia State during the different regional seasons of 1998 to 1999. A total of 244 bugs belonging to 17 species were collected of which 13 had trypanosomatid infections. Methanol fixed smears of all the infections were made on glass slides and stained with Giemsa for the morphological studies and morphometric analyses. In a second phase, we used the PCR (Polimerase Chain Reaction) to recover DNA from the methanol fixed smears. The PCR products were hybridized with the SL3’ probe which is specific for Phytomonas. The aim of this preliminary study was to locate trypanosomatids infections in phytophagous Hemiptera captured in Rondônia State and then determine which of these belonged to the genus Phytomonas without the necessity of isolation in culture.
60

Mikrostrukturní optická vlákna s dutým jádrem / Hollow Core Photonic Crystal Fibers

Hlavatý, Václav January 2015 (has links)
Aim of the work was to study, design and verify methods of splicing photonic crystal fibers with standard single-mode and multi-mode fibers. The main goal was to make of the fusion splicer Fujikura FSM 100P splicing process. To create splicing process, various splicing methods were tested. Method of the moving position of the arc discharge from the center of splicing fibers and the method with increased gas pressure in the microstructure were mainly tested. Research revealed the incompatibility of splicing process of the different types of fiber splicers. The main results of the work are optimized methods of the splicing HC 1550-2 fiber and SMF 28 fiber.

Page generated in 0.0424 seconds