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Expression ectopique du gène homéotique Cdx2 dans les pathologies du système digestif / Ectopic expression of the homeotic gene Cdx2 in digestive pathologiesNair, Asmaa 24 January 2018 (has links)
Le facteur de transcription homéotique CDX2 est spécifiquement exprimé dans l’épithélium intestinal où il maintient l’identité, contrôle l’homéostasie et exerce une fonction suppresseur de tumeurs. Chez l’homme, une expression ectopique (hors de l’intestin) de CDX2 peut survenir, dans les métaplasies intestinales d’organes digestifs, considérées comme pré-cancéreuses. Ce travail de thèse visait à étudier les conséquences physiopathologiques de l’expression ectopique de CDX2. Nous avons développé et validé un modèle murin d’induction conditionnelle de CDX2 dans plusieurs organes digestifs. Nos résultats montrent que cette expression est dépendante du contexte cellulaire, et induit des métaplasies intestinales seulement dans l’estomac et le pancréas. Ces métaplasies n’évoluent pas spontanément en cancer. Cependant, CDX2 sensibilise ces lésions métaplasiques à l’apparition de tumeurs intestinales dans l’estomac placé dans un contexte où le gène Apc est muté. Globalement, ces résultats montrent que CDX2 est essentiel au développement de métaplasies intestinales mais n’exercerait pas de fonction oncogénique en situation ectopique. / The intestine-specific homeotic transcription factor CDX2 is required throughout life for intestinal homeostasis, the maintenance of intestinal identity and has tumor suppressor activity. In Human, ectopic expression of the gene Cdx2 is observed in several digestive organs as in intestinal metaplasia which is considered as pre-cancerous lesion. This work aimed to investigate the pathophysiological consequences and molecular mechanisms of ectopic expression of CDX2. We created and validated a conditional murine model of CDX2 induction in several digestive organs. Ectopic CDX2 causes intestinal metaplasias only in the stomach and the pancreas which do not spontaneously evolve to cancer, depending on cellular context. However, CDX2 promotes intestinal carcinogenesis in complete intestinal metaplasia of the stomach. Collectively, these results show that CDX2 is essential for the development of intestinal metaplasia but has no oncogenic function in ectopic situation.
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Trans-acting elements required for the localization of bicoid mRNA.January 2001 (has links)
Siu-wai Michael Sung. / Thesis submitted in: December 2000. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 97-111). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Abbreviations --- p.v / Table of Contents --- p.vii / Chapter Chapter 1 --- General Introduction / Chapter l. 1 --- Drosophila as a model for studying development --- p.1 / Chapter l .2 --- The formation of the body axis in Drosophila --- p.2 / Chapter l .3 --- Maternal genes are essential for development --- p.9 / Chapter 1.4 --- Maternal gene bicoid is essential for formation of the anterior structures in the embryo --- p.13 / Chapter 1.5 --- Establishment of an anterior to posterior bicoid protein gradient --- p.13 / Chapter 1.6 --- The bicoid protein gradient controls the downstream zygotic target genes in a concentration-dependent manner --- p.17 / Chapter 1.7 --- Bicoid protein acts as transcriptional regulators \9 --- p.19 / Chapter 1.8 --- Bicoid protein acts as transcriptional regulators --- p.21 / Chapter 1.9 --- The anterior localization of bcd mRNA --- p.21 / Chapter 1.10 --- Components required for bcd mRNA localization at anterior pole of oocyte / Chapter 1.10.1 --- Cis-acting elements --- p.22 / Chapter 1.10.1.1 --- BLE1 at 3' UTR directs localization of bcd mRNA --- p.23 / Chapter 1.10.2 --- Trans-acting elements / Chapter 1.10.2.1 --- "Exuperantia, swallow, and staufen are necessary for localization for bcd mKNA" --- p.27 / Chapter 1.10.2.2 --- exu protein is an absolute requirement for localization for bcd mRNA --- p.30 / Chapter 1.10.2.3 --- Microtubules dependence of localization --- p.31 / Chapter 1.11 --- Functions of exu in localization of bcd mRNA --- p.32 / Chapter 1.12 --- Characteristics of Bicoid protein and Bic-D gene --- p.33 / Chapter 1.13 --- Aim of Project --- p.36 / Chapter CHAPTER 2 --- Materials and Methods / Chapter 2.1 --- Fly Food --- p.37 / Chapter 2.2 --- Conditions in maintaining the fly stocks and working stocks --- p.37 / Chapter 2.3 --- Localization of exu protein and other intracellular elements by indirect immunofluorescence detection / Chapter 2.3.1 --- Immunohistrochemical distribution of exu and Bic-D protein --- p.38 / Chapter 2.3.2 --- Immunohistrochemical distribution of β-tubulin --- p.39 / Chapter 2.4 --- Preparation of total protein from the female and male flies --- p.41 / Chapter 2.5 --- Analysis of interactions between exu and trans-acting elements / Chapter 2.5.1 --- 35S-methionine metabolic labelling and immunoprecipitation by RIPA buffer --- p.41 / Chapter 2.5.2 --- 35S-methionine metabolic labelling and immunoprecipitation by Mach and Lehmann buffer system --- p.43 / Chapter 2.6 --- Co-immunoprecipitation of exu and Bic-D protein / Chapter 2.6.1 --- Co-immunoprecipitation of exu and Bic-D protein synthesized by in vitro coupled transcription and translation system with modified Mach and Lechmann buffer system --- p.44 / Chapter 2.7 --- in vivo ovary extract co-immunoprecipitation / Chapter 2.7.1 --- in vivo ovary extraction co-immunoprecipitation of exu and Bic-D protein with modified Mach and Lehmann buffer system supplemented with recombinant exu protein --- p.45 / Chapter CHAPTER 3 --- Results / Chapter 3.1 --- Analysis of co-localization of exu and Bic-D protein by double immuno-fluorescence staining on w1118 flies --- p.47 / Chapter 3.2 --- Analysis of co-localization of exu protein and β-tubulin protein by double immuno-fluorescence staining on w1118 flies --- p.51 / Chapter 3.3 --- Analysis of co-localization of exu and Bic-D protein by double immuno-fluorescence staining on Bic-D mutants --- p.55 / Chapter 3.4 --- Co-immunoprecipitation of exu and Bic-D protein synthesized by in vitro coupled transcription and translation system --- p.61 / Chapter 3.5 --- 35S-Methionine metabolic labelling and co-immunoprecipitation of exu and Bic-D protein with RIP A buffer system --- p.65 / Chapter 3.6 --- 35S-Methionine metabolic labelling and co-immunoprecipitation of exu and Bic-D protein with Mach and Lehmann buffer system --- p.68 / Chapter 3.7 --- in vivo ovary extract co-immunoprecipitation of exu and Bic-D protein with modified Mach and Lehmann buffer system supplemented with recombinant exu protein --- p.71 / Chapter CHAPTER 4 --- Discussion / Chapter 4.1 --- Analysis of co-localization of exu protein and other intracellular elements by indirect double immunofluorescence staining detection --- p.74 / Chapter 4.2 --- Analysis of co-localization of exu and BicD protein by double immuno- fluorescence staining on Bic-D mutants --- p.78 / Chapter 4.3 --- Co-immunoprecipitation of exu and BicD protein synthesized by in vitro coupled transcription and translation system --- p.79 / Chapter 4.4 --- Analysis of interactions between exu and trans-acting elements by 35S- Methionine metabolic labelling and immunoprecipitation --- p.82 / Chapter 4.5 --- "in vivo ovary extract coimmunoprecipitation of exu and Bic-D protein with modified Mech and Lehmann buffer system, supplemented with recombinant exu protein" --- p.84 / Chapter 4.6 --- Recent developments on the concept of ribonucleoprotein --- p.86 / Appendix A Supplementary protocols --- p.91 / Appendix B Reagents --- p.95 / Reference --- p.97
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Síntese, caracterização e reatividade química de complexos de cloro e nitrosil de trans-Tetrakispiridina de rutênio / Syntheses, Characterization and Chemical Reactivity of Chloro and Nitrosyl Complexes of trans-Tetrakispyridines of RutheniumCalandreli, Ivy 04 December 2009 (has links)
Neste trabalho foram realizadas as sínteses dos complexos trans-[RuCl2(L)4] (L = py, isn, 4-acpy e 3-acpy), trans-[RuCl(NO)(L)4](PF6)2 (L = py, isn e 4-acpy), trans-[Ru(OH)(NO)(py)4](PF6)2, trans-[RuCl(NO)(py)4]Cl23H2O, trans-[Ru(OH)(NO)(py)4]Cl2, cis-[RuCl2(DMSO)4], trans-[Ru(NO2)2(py)4], trans-[RuCl(NO2)(py)4], trans-[RuCl(acn)(py)4](PF6) e do complexo reduzido trans-[RuCl(NO)(py)4]I. Estes compostos foram submetidos a várias técnicas de caracterização como: análise elementar de CHN, espectroscopia de 1H RMN, espectroscopia na região do UV-vis e IV, técnicas de eletroquímica e EPR. A análise elementar de CHN e os espectros de 1H RMN se mostraram consistentes com as estruturas propostas, indicando a pureza destes compostos segundo estas técnicas. A caracterização por espectroscopia na região do UV-vis mostrou que os novos complexos apresentaram semelhança espectral com compostos semelhantes descritos na literatura. Entretanto, para os complexos trans-[RuCl(NO)(L)4](PF6)2 (L = py, isn e 4-acpy) e trans-[RuCl(NO)(py)4]Cl23H2O não se observa a banda entre 300-400 nm, comumente observada para tetraaminas de rutênio com o NO coordenado e nas bipiridinas de rutênio com o ligante nitrosilo. Os espectros de absorção na região do IV para os complexos nitrosilos apresentaram a banda da freqüência de estiramento do NO (NO) entre 1870 -1920 cm-1, indicando o caráter nitrosônio do NO. O complexo reduzido trans-[RuCl(NO)(py)4]I apresenta a banda de NO em 1854 cm-1 em acetonitrila, este valor está consistente com o deslocamento da banda de NO observado durante a eletrólise para a redução de trans-[RuCl(NO)(py)4]2+. A atribuição desta banda ao NO0 é reforçada pelo estudo de EPR, cujos espectros apresentaram um sinal característico de NO0 coordenado tanto para o complexo reduzido com iodo trans-[RuCl(NO)(py)4]I como para a solução eletrolisada de trans-[RuCl(NO)(py)4]2+. Os estudos de eletroquímica para os complexos trans-[RuCl2(L)4] (L = py, isn, 4-acpy e 3-acpy) apresentaram um processo de redução reversível, cujo Ef aumenta com o aumento da capacidade receptora de elétrons do ligante L, py < isn < 4-acpy. O comportamento eletroquímico de trans-[RuCl(NO)(L)4](PF6)2 (L = py e 4-acpy), em acetonitrila, apresentou um processo de redução reversível atribuído a 6/7 e um processo irreversível atribuído a redução 7/8. Após a redução do trans-[RuCl(NO)(py)4]2+ por eletrólise, em acetonitrila, foi observada a formação de trans-[RuCl(NO2)(py)4] para Eaplicado = -0,535 e -1,435 V vs Fc+/Fc. Em menor proporção, foi observado também a formação de trans-[RuCl(acn)(py)4]+, produto da liberação de NO (mas somente quando Eaplicado = -1,435 V vs Fc+/Fc). Em solução aquosa, os voltamogramas cíclicos do complexo trans-[RuCl(NO)(py)4]2+ apresentaram três processos de redução. O primeiro processo é referente à redução 6/7, o segundo corresponde à redução 7/8 e o terceiro processo envolve quatro elétrons convertendo o grupo nitrosil a amônia (NO- NH3). Durante a eletrólise, em solução aquosa, observou-se a formação de uma espécie a mais, além do composto trans-[RuCl(NH3)(py)4]+. Possivelmente, esta espécie seja o complexo trans-[RuCl(H2O)(py)4]+ (ou trans-[RuCl(OH)(py)4], dependendo do pH) derivado da liberação de NO. A grande capacidade -receptora dos ligantes piridínicos no plano equatorial dos complexos de rutênio, apresentados neste trabalho, se reflete em várias propriedades como: na energia da TCML, nos potenciais de redução e na acidez da água coordenada em trans ao NO do complexo trans-[Ru(NO)(H2O)(py)4]3+ (pKa < 1) que aumenta consideravelmente em relação ao trans-[Ru(NO)(H2O)(NH3)4]3+, (pKa = 3,1). / The complexes trans-[RuCl2(L)4] (L = py, isn, 4-acpy e 3-acpy), trans-[RuCl(NO)(L)4](PF6)2 (L = py, isn e 4-acpy), trans-[Ru(OH)(NO)(py)4](PF6)2, trans-[RuCl(NO)(py)4]Cl23H2O, trans-[Ru(OH)(NO)(py)4]Cl2, cis-[RuCl2(DMSO)4], trans-[Ru(NO2)2(py)4], trans-[RuCl(NO2)(py)4], trans-[RuCl(acn)(py)4](PF6) and the reduced complex trans-[RuCl(NO)(py)4]I were synthesized. The compounds were analyzed and characterized by elemental analysis of CHN, 1H NMR, UV-vis and IR spectroscopies, electrochemical techniques and EPR. The elemental analyses and 1H NMR spectra were consistent with the proposed structures indicating the purity of the compounds, according to these techniques. The UV-vis spectra of the complexes are similar to those of related complexes. However, for trans-[RuCl(NO)(L)4](PF6)2 (L = py, isn e 4-acpy) and trans-[RuCl(NO)(py)4]Cl23H2O, the band between 300-400 nm, usually seen in other nitrosyl ruthenium complexes spectra, as tetraamines and bipyridines complexes, was not observed. The IR spectra for nitrosyl complexes showed the stretching frequency band (NO) between 1870 -1920 cm-1, which is consistent with the nitrosonium character of these compounds. The reduced complex trans-[RuCl(NO)(py)4]I shows a NO band in 1854 cm-1 (acetonitrile). This value is consistent with the NO band shift observed during the trans-[RuCl(NO)(py)4]2+ reduction electrolysis. The assignment of this band to NO0 is consistent with the EPR studies, whose spectra showed a NO0 coordinated signal for the reduced complex trans-[RuCl(NO)(py)4]I and for the electrolyzed solution of trans-[RuCl(NO)(py)4]2+. The electrochemical studies for trans-[RuCl2(L)4] (L = py, isn, 4-acpy e 3-acpy) show a reversible reduction process assigned to RuIII/RuII, whose Ef increases with the -acceptor ability of the L ligand. In acetonitrile, the electrochemical behavior of trans-[RuCl(NO)(L)4](PF6)2 (L = py e 4-acpy), showed two reduction processes. The first is a reversible process assigned to 6/7 and the second is an irreversible process assigned to 7/8. The trans-[RuCl(NO2)(py)4] complex is formed during the reduction electrolysis of trans-[RuCl(NO)(py)4]2+ in acetonitrile with Eapplied = -0,535 and -1,435 V vs Fc+/Fc. The trans-[RuCl(acn)(py)4](PF6) is also formed after the NO release (only Eapplied = -1,435 V vs Fc+/Fc). In aqueous solution, the trans-[RuCl(NO)(py)4]2+ electrochemical behavior is different from that in acetonitrile. The cyclic voltammograms show three reduction processes. The first is a reversible process assigned to 6/7, the second is irreversible assigned to 7/8 and the third is a NO- NH3 four electron reduction. The electrolysis in aqueous solution generated another specie besides trans-[RuCl(NH3)(py)4]+, which should be the trans-[RuCl(H2O)(py)4]+ (or trans-[RuCl(OH)(py)4], depending on the pH) following the NO release. The great -acceptor ability of the L ligand in the ruthenium equatorial plane, presented in this work, reflects in many properties, such as: MLCT energy, reduction potential and the coordinated water acidity in trans-[Ru(NO)(H2O)(py)4]3+, (pKa < 1), which increases substantially compared to trans-[Ru(NO)(H2O)(NH3)4]3+ (pKa is 3,1).
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Sobre corpos insolentes: corpo trans, um ensaio estético da diferença sexual em educaçãoCHAVES, Silvane Lopes 30 June 2015 (has links)
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Previous issue date: 2015-06-30 / Este texto dissertativo situa-se no limiar discursivo entre sexualidade e educação. Apoiado no pensamento trágico e genealógico de Nietzsche e Foucault e no diálogo com Sade, Deleuze e Guattari, Derrida, os estudos que, a pesquisa apresenta a perspectiva do corpo trans como dimensão constitutiva da diferença sexual. Discute a noção de diferença sexual como dimensão fronteiriça e indeterminada da sexualidade e problematiza o paradigma da inclusão como suposto acolhimento da diferença na educação. No campo discursivo da sexualidade, tensiona as categorias “homossexualidade”, “visibilidade” e “identidade de gênero e sexual”, dando atenção à palavra que fala e à palavra que cala, na pronúncia da diferença sexual, para fazer emergir um corpo trans como radicalidade da diferença sexual e como singularidade de encarnação de uma vida singular guiada por uma ascese dionisíaca: o corpo trans como estética subversiva à conformidade da norma e como convite ao “tornar-se aquilo que é”, um transitar do corpo-fronteiriço por diferentes territorialidades, enlaçado à mitologia antiga e à “literatura menor” de Kafka. O trabalho perscruta os diferentes olhares que se constituíram historicamente sobre o corpo, expondo alguns de seus deslocamentos e efeitos discursivos sobre os modos de pensar a relação corpo - diferença sexual, em articulação com a educação. A estética trans é vista por um exercício de liberdade agonística e uma arte da existência capaz de potencializar no corpo sua verdade primeira e fazer dele um espaço de luta política, resistência, arte-transgressão. Nesse ensaio de criação de uma personagem conceitual (o corpo trans), propõe situá-lo enquanto existência menor, de modo a encarnar um valor político e coletivo frente à arbitrariedade da norma, e enquanto exercício de desterritorialização do masculino e do feminino. Enquanto produção de singularidade, interpela e intervém na educação, exigindo um tratamento ético, de modo a torná-la um espaço de promoção do encontro entre multiplicidades conectadas. / This dissertative text is located in a discursive threshold between sexuality and education. Supported by the tragic and genealogical thought of Nietzsche and Foucault and in the dialogue with Sade, Deleuze and Guattari, Derrida, queer studies, the research presents a trans body perspective as a constitutive dimension of sexual difference. It discusses the notion of sexual difference as boundary and indeterminate dimension of sexuality and questions the paradigm of the inclusion as alleged host of the difference in education. In the discursive field of sexuality, tensions the categories "homosexuality", "visibility" and "gender and sexual identity", paying attention to the word that speaks and to the word that shuts in pronunciation of sexual difference, to the emergence of a trans body as radicality of sexual difference and as uniqueness the embodiment of a singular life guided by a Dionysian asceticism: the trans body as subversive aesthetic to the compliance of the standard and as an invitation to the "become what it is", a transition from body boundary by different territorialities, tied to the old mythology and the "minor literature" of Kafka. The work examines the different views that were historically constituted on the body, exposing some of their movements and discursive effects on the ways of thinking the body relation and sexual difference, in conjunction with education. The trans aesthetic is seen by an exercise of agonistic freedom and an art of existence able to enhance in the body its first truth and make it a political battle space, endurance, art transgression. In this essay of creating a conceptual character (trans body), proposes to situate it as minor existence, in order to embody a collective value against the arbitrariness of the standard, and as an exercise in deterritorialization of male and female. As production of uniqueness, challenges and intervenes in education, requiring an ethical treatment so as to make it a space to promote the meeting among connected multiplicities.
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Euclidean DomainsTombs, Vandy Jade 01 July 2018 (has links)
In the usual definition of a Euclidean domain, a ring has a norm function whose codomain is the positive integers. It was noticed by Motzkin in 1949 that the codomain could be replaced by any well-ordered set. This motivated the study of transfinite Euclidean domains in which the codomain of the norm function is replaced by the class of ordinals. We prove that there exists a (transfinitely valued) Euclidean Domain with Euclidean order type for every indecomposable ordinal. Modifying the construction, we prove that there exists a Euclidean Domain with no multiplicative norm. Following a definition of Clark and Murty, we define a set of admissible primes. We develop an algorithm that can be used to find sets of admissible primes in the ring of integers of quadratic extensions of the rationals and provide some examples.
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Anti-cancer immunotherapy using an adenovirus vaccine in combination with retinoic acid-loaded nanoparticlesde Barros, Cristina Maria 01 August 2019 (has links)
Cancer immunotherapy is an approach to cancer therapy that involves the enhancement of the cancer patient’s own innate and/or adaptive immune systems to attack their own cancer. Clinically available cancer immunotherapies rely on different strategies: infusion of ex vivo manipulated autologous dendritic cells (DCs), infusion of genetically engineered autologous cytotoxic CD8+ T lymphocytes, stimulation of T lymphocyte proliferation, or inhibition of immunosuppressive pathways to improve T lymphocyte effector function. Nonetheless, only a small percentage of cancer patients receive benefit from immunotherapies and thus further improvements in clinical outcomes are required. Among numerous other therapeutic immunotherapies strategies being developed and tested, adenovirus serotype 5-based vectors (Ad5) have been well studied in preclinical and clinical settings. Preclinical research has shown that vaccination of mice with Ad5-OVA (an Ad5 encoding a model tumor antigen, chicken ovalbumin (OVA)) results in activation and proliferation of OVA-specific CD8+ T lymphocytes capable of specific killing of tumor cells that express OVA. This dissertation evaluates the potential of polymeric nanoparticles (NP) loaded with all-trans retinoic acid (ATRA), a vitamin A derivative with potent immunostimulatory effects, to improve the immunostimulatory and therapeutic effects of Ad5-OVA in a murine E.G7-OVA tumor model, a well described model that can be used for studying the immune response to Ad5-based immunotherapies.
In the first part of this work, poly(lactide-co-glycolide) NP loaded with ATRA (ATRA-PLGA-NP) were prepared and characterized. Next, the antitumor effect and the magnitude of the OVA-specific immune response due to Ad5-OVA vaccination versus ATRA-PLGA-NP (or ATRA soluble) plus Ad5-OVA combination treatment were compared in vivo. The results showed that the combination treatment using ATRA-NP, but not ATRA soluble, resulted in enhanced survival and enhanced levels of OVA-specific CD8+ T lymphocytes in peripheral blood, spleen, and tumor.
Next, cRGD- and mannose-functionalized PLGA-PEG NP were developed in an attempt to actively target the tumor neovasculature and DC-rich organs, respectively. The functionalization efficacy was confirmed by ex vivo fluorescence imaging studies. In vivo studies using E.G7-OVA-challenged mice showed that treatment with ATRA-loaded cRGD-functionalized PLGA-PEG-NP + Ad5-OVA, despite not enhancing the levels of OVA-CD8+ T lymphocytes in peripheral blood, substantially enhanced survival compared to either the combination of Ad5-OVA + non-functionalized ATRA-PLGA-PEG-NP or Ad5-OVA + conventional ATRA-PLGA-NP. On the contrary, treatment with mannose-functionalized PLGA-PEG-NP + Ad5-OVA, despite optimally enhancing the levels of OVA-CD8+ T lymphocytes in peripheral blood (compared to all other treatment groups), did not lead to enhanced survival compared to either the combination of Ad5-OVA + non-functionalized ATRA-PLGA-PEG-NP, Ad5-OVA + conventional ATRA-PLGA-NP, and over Ad5-OVA treatment alone. Although not investigated further in this dissertation, it was speculated that the observed trend in survival benefit provided by ATRA-PLGA-PEG-cRGD-NP + Ad5-OVA over the other NP formulations may have been due to higher levels of ATRA within the TME due to actively targeting the tumor vasculature, corroborating previous studies which demonstrated that ATRA functions as a potent stimulator of anti-tumor cellular immune responses within the tumor. The paradoxical results obtained with mannose-functionalized PLGA-PEG-NP are less readily explained.
In conclusion, it was demonstrated in this work that the co-administration of Ad5-OVA and ATRA-loaded NP formulations enhanced the tumor specific cellular immune response and the survival of tumor challenged mice compared to vaccination with Ad5-OVA alone.
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Targeting interleukin-6 trans-signaling in head and neck squamous cell carcinomaDahl, Rachel A. 01 May 2018 (has links)
Title: Inhibition of interleukin-6 trans-signaling by sgp130Fc is anti-tumorigenic in head and neck squamous cell carcinoma.
Background: Head and neck squamous cell carcinoma (HNSCC) is a highly inflammatory cancer type, and interleukin-6 (IL-6) is associated with this phenotype. Elevated expression of IL-6 is linked to tumor progression, recurrence, metastasis, and resistance to therapy in HNSCC. However, targeting IL-6 or IL-6 receptor (IL-6R) has demonstrated little to no clinical efficacy.
IL-6 signals through a classical signaling pathway via membrane IL-6R or a trans-signaling pathway via soluble IL-6R (sIL-6R). Recent evidence suggests that classical signaling induces acute, transient inflammation, eventually resulting in homeostasis; whereas trans-signaling may induce chronic, pro-tumorigenic inflammation. Therefore we propose that IL-6 trans-signaling is associated with the pro-inflammatory phenotype observed in HNSCC. We wanted to determine whether inhibition of IL-6 trans-signaling by sgp130Fc would better demonstrate anti-tumor efficacy and increase HNSCC tumor response to radiation, chemotherapy, and targeted therapy (cetuximab) compared to global IL-6 pathway inhibition.
Method/Results: Baseline levels of IL-6, IL-6R, sIL-6R, and sgp130 proteins in HNSCC cells were determined using ELISA and flow cytometry. Cisplatin, radiation, and cetuximab treatments each induced HNSCC cell secretion of IL-6 and sIL-6R in vitro, yet adding sgp130Fc to those treatments did not further reduce clonogenic survival. Sgp130Fc treatment significantly suppressed SQ20B tumor growth in nude mice, whereas global IL-6 pathway inhibition by IL-6R antagonist tocilizumab did not; however, cetuximab reduced the efficacy of sgp130Fc in this animal model. Sgp130Fc also sensitized SQ20B xenograft tumors to radiation and chemotherapy in nude mice and suppressed SCCVII tumor growth in male but not female C3H/HeJ mice.
Conclusion: Inhibition of IL-6 trans-signaling by sgp130Fc displayed significant anti-tumor effects as a single therapy and sensitized resistant HNSCC tumors to radiation and chemotherapy in vivo; however, sgp130Fc did not reduce survival of HNSCC cells in vitro. These results suggest that the efficacy of sgp130Fc relies on targeting another part of the microenvironment instead of tumor cells directly. Sgp130Fc has promise both as a single therapy and potentially as combined therapy with radiation and chemotherapy in HNSCC.
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Optimization of Aggregating agents and SERS Substrates for SERS detection of Cotinine and trans 3'-hydroxycotinineHan, Sungyub 05 February 2015 (has links)
This dissertation mainly focuses on applications of Surface Enhance Raman Scattering (SERS) to detect tobacco-related biomarkers with optimized experimental conditions (pH and aggregating agents) and SERS substrates (silica core and silver shell nanoparticles). Cotinine (COT) and trans 3-hydroxycotinine (3HC), metabolized from nicotine as one of main chemicals of tobacco, have been used as tobacco biomarkers because their half-life are longer than that of nicotine, which enable to monitor the tobacco exposure. The effects of aggregating agents and pH on SERS detection of COT and 3HC were investigated. Aggregating agents play an important role in SERS detection of target molecules since the strong SERS enhancements are observed from junctions of nanoparticles which can be induced by aggregating agents, and so called "hot spot". That is, the more hot spots are created among the nanoparticles by aggregating agents, the higher the SERS enhancement is. Five cationic (K+, Na+, Mg2+, Li+, Ca2+) and three anionic (Cl-, Br-, I-) aggregating agents were tested. Interestingly but not surprisingly, optimal concentrations of 11 kinds of aggregating agents for COT and 3HC detections vary dramatically within two orders of magnitude. In addition, the effect of pH conditions on SERS intensity of COT and 3HC was investigated since the protonated or deprotonated molecules induced by various ranges of pH values produces change in SERS intensity of the molecule. The highest SERS enhancement is obtained using 1.5 mM MgCl2 for COT at pH 7 and 50 mM NaBr for 3HC at pH 3. Both cations and anions strongly influence the SERS enhancement.
SERS enhancement depends also significantly on the type of metallic substrates. This indicates the choice of metallic substrate is critically important to achieve strong SERS enhancement. While Ag is the most commonly used materials for SERS substrates and has been demonstrated to exhibit high enhancement. It has the disadvantage of limited selection of excited wavelengths, which prevents to apply Ag SERS substrates to biological field. Dielectric core and metallic shell structure has been theoretically studied and it has been proposed that silica core and silver shell (SiO2@Ag) nanoparticles produces higher plasmon resonance than that of silver nanoparticles and their surface plasmon are tunable by controlling shell thickness. Here, SiO2@Ag nanoparticles were successfully fabricated and their activity as substrates for surface-enhanced Raman scattering (SERS) were examined. Both the core and the shell thickness exhibit strong effect on the SERS activity. Using Rhodamin 6 G (R6G) as a probe molecule, it was observed that SERS intensities of R6G were susceptible to change in Ag shell thickness and the size of core-shell nanoparticles. The 76 nm SiO2@ 23 nm Ag shell nanoparticles shows highest SERS intensity of R6G. Moreover, 76nm SiO2@ 23 nm Ag nanoparticles have higher SERS enhancements of R6G, 4-aminothiophenol (4-ATP), and cotinine (COT) than that of both silver nanoparticles and SiO2@Ag nanoparticles of previous studies. Also, the tuneability of surface plasmon of core-shell structure is flexible by changing in the size of either core or shell.
In addition, three Raman spectroscopy application in material science fields were studied: MP-11 encapsulated inside of Tb-mesoMOFs, poly(methyl methacrylate) composites of copper-4,4'-trimethylenedipyridein, and surfactant-free TiO2 surface hydroxyl groups. For the first study, the interaction between the ligands of Tb-meso MOFs and MP-11 was examined. Individual Raman bands of MP-11 and the ligands of Tb-mesoMOFs were distinguished and some of bands were shifted from the complex of MP-11@Tb-mesoMOFs. It is turned out that the interactions is involved through π•••π interactions between the heme and the conjugated triazine and benzene rings of TATB ligand. Next, Raman was used to study the interaction between poly methyl methacrylate (PMMAP) composites and copper-4,4'-trimethylenedipyridein (CU-TMDP). Copper contained in polymer materials has shown improvement performance (thermal and mechanical stability). The Raman results reveal a red-shift of vibrational peaks associated with pyridine ring of CU-TMDP when CU-TMDP is dispersed into PMMA. This interaction, a dipole-dipole interaction or London dispersion force, may produce the stability improvement of metal-containing polymer. The last application is about the effect of pH levels on the phase of TiO2 crystalline. TiO2 crystal has attractive advantage of self-cleaning property. The efficiency of self-cleaning of TiO2 is dependent on the phases (anatase, rutile, and brookite) of TiO2. Raman study revealed that the formation of the anatase phase of TiO2 is interrupted as the pH level increases.
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Experimental analysis of trans-splicing of an ascidian troponin I geneMortimer, Sandra, 1981- January 2007 (has links)
No description available.
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410 |
Peroxide value and trans analyses by Fourier transform infrared (FTIR) spectroscopyMa, Kangming, 1965- January 2000 (has links)
No description available.
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