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.

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.

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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No description available.

Thesis (D. Min.)--Trinity International University, Deerfield, Ill., 1998. / Abstract. Includes bibliographical references (leaves 149-156).

Les petits corps sont des clés pour comprendre notre système solaire. L'étude de cette population nous donne en effet accès aux informations sur l'état et sur la structure du système solaire primordial et du système solaire actuel, ainsi que sur son évolution et sur les processus de formation des planètes. Connaître la composition de surface des petits corps nous fournit des ingrédients et des proportions pour cette recette cosmique. Cette thèse, qui inclut l'étude des petits corps du système solaire interne et externe, est dédiée à la compréhension de la tendance compositionnelle des corps à travers le système solaire en utilisant des mesures photométriques et spectroscopiques. Je présente une classification (taxonomie) dans les longueurs d'ondes du visible et du proche infrarouge (de 0.4 à 2.4 µm), basée sur les données spectrales de 371 astéroïdes. Cette taxonomie comprend 24 classes qui chacune caractérise au mieux les variations spectrales observées parmi les petits corps du système solaire interne. De part la création de cette taxonomie, nous apprenons qu'en analysant les données dans les longueurs d'ondes du visible uniquement, il reste des incertitudes sur la forme de la bande d'absorption à 1 micron. Bien que la gamme de longueur d'onde du proche infrarouge soit excellente pour interpréter les données incluant les bandes diagnostiques à 1 et 2 microns, les complexes C et X des spectres sans fortes bandes paraissent plutôt dégénérés dans ce régime. J'analyse les couleurs photométriques des 23 objets trans-neptuniens (OTN) et Centaures, parmi lesquels neuf n'avaient jamais été observés précédemment, et je leur assigne une classe taxonomique. Je discute des objets qui ont soit changé de classe depuis les données préalables soit changé considérablement de magnitude absolue. De plus, j'interprète la composition de surfaces de trois petits corps du système solaire externe, l'objet couplé avec Jupiter (52872) Okyrhoe et les OTNs (90482) Orcus et (73480) 2002 PN34 en modélisant des mesures spectroscopiques dans les gammes du visible et du proche infrarouge. Les spectres révèlent des variations de quantité de glace d'eau à la surface de ces corps. Pour Orcus j'apporte des contraintes approximatives sur la présence de matériaux plus volatiles que la glace d'eau. Ensuite, je présente une recherche de l'éthane solide, C2H6, sur les surfaces de Pluton et de Triton. Celle-ci est basée sur les observations spectrales dans les longueurs d'ondes du proche infrarouge. Je modélise chaque surface en utilisant un modèle de transfert radiatif fondé sur la théorie de Hapke (Hapke, 1993) de trois manières : sans éthane, avec de l'éthane pur, et avec de l'éthane dilué dans de l'azote. La présence de moins de quelques pourcents d'éthane sur chaque corps ne permet pas d'exclure ce composant de Triton et Pluton, cependant il n'y a pas non plus de forte détection. Finalement, je reconsidère la connaissance actuelle de la distribution compositionnelle des matériaux de notre système solaire en fournissant une vue globale des petits corps. Je me concentre particulièrement sur la présence de l'eau dans toutes ses phases qui est pertinente surtout pour notre propre planète, la Terre, et la vie. Je compare brièvement la structure générale de notre système solaire aux autres disques d'accrétion, afin de mettre en perspective la vue détaillée mais cependant étroite de notre système solaire avec celle, plus large mais à basse résolution, des autres systèmes planétaires.

<p>Ribosomes stalled on problematic mRNAs can be rescued by a mechanism called <i>trans</i>-translation. This mechanism employs a dual transfer-messenger RNA molecule (tmRNA) together with a helper protein (SmpB). </p><p>In this work we have used an <i>in vitro</i> translation system with pure components to further clarify the roles of tmRNA and SmpB in <i>trans-</i>translation. </p><p>We found that SmpB binds ribosomes <i>in vivo</i> and <i>in vitro</i> independently of tmRNA presence and is essential for tmRNA binding and <i>trans-</i>peptidation. We show that two SmpB molecules can bind per ribosome, that SmpB does not leave the ribosome after <i>trans-</i>peptidation and that SmpB pre-bound to the ribosome can trigger <i>trans-</i>translation. </p><p>We demonstrated that the rate of <i>trans-</i>transfer of a peptide from the P-site tRNA to Ala-tmRNA and the efficiency by which Ala-tmRNA competes with peptide release factors decrease with increasing the mRNA length downstream from the P site of the ribosome. We showed that <i>trans-</i>translation is strongly stimulated by RelE cleavage of A-site mRNA. We concluded that tmRNA action<i> in vivo</i> must always be preceded by mRNA truncation.</p><p>We showed that rapid release of truncated mRNAs from the ribosome requires translocation of the peptidyl-tmRNA into the ribosomal P site, which is strictly EF-G dependent. mRNA release is slowed down by strong Shine and Dalgarno like sequences upstream the A site and by long 3’-extensions downstream from the P-site codon. </p><p>Footprinting was used to monitor SmpB binding to tmRNA, ribosomes and subunits and to study tmRNA interactions with the ribosome at distinct <i>trans-</i>translation stages. We confirmed that two SmpB molecules bind per ribosome and interact with nucleotides below the L7/L12-stalk on the 50S subunit and near the subunit interface on the 30S. We showed that tmRNA is mostly in complex with SmpB <i>in vivo</i> and during <i>trans-</i>translation. Specific cleavage patterns of tmRNA were observed at different stages of <i>trans-</i>translation, but the overall tmRNA conformation seems to be maintained during the whole process.</p>

<p>The toxicity of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) was measured. When Caco-2 cells from human adenocarcinoma are cultivated on a filter a monolayer is formed with properties similar to human duodenum epithelium. The Caco-2 cells grown on filter were exposed to the environmental contaminants PFOS and PFOA. The effects on the Caco-2 epithelium were examined by four different methods: trans-epithelial resistance (TEER), leakage of the intracellular protein lactate dehydrogenase (LDH), 14C-mannitol passage through the epithelium and protein content of the epithelium. TEER and C-mannitol passage show the Caco-2 cellmonolayer integrity, LDH leakage gives information of cytotoxicity and protein content of the epithelium shows cell adhension to the filter.</p><p>In the first study TEER decreased at the highest concentrations of PFOS and PFOA (1Mm). The 14C-mannitol passage increased at the highest PFOS concentration. No cytotoxicity was shown and protein-loss was not observed. The second study with PFOS doses of 0, 1, 10, 100 and 500µM and 1 and 10mM showed that the effect of PFOS on TEER was dose-dependent. The 14C-mannitol passage was very high at the highest PFOS-concentration (10mM) and a dose-response was indicated. No cytotoxicity was demonstrated and protein-quantity was not affected. In the third study it was demonstrated that the toxicity of PFOS did not depend on the different concentrations of the oil-emulsion used to dissolve PFOS and PFOA.</p>

Consumption of food away from home (FAFH) is widely believed to be a contributing factor to the current obesity crisis and other diet related problems in North America. At present, in Canada, a number of issues related to FAFH consumption such as the relationship between obesity and fast foods, trans-fats, sugar and sodium content of restaurant foods, and restaurant advertising for children are being widely discussed. In these discussions, it is apparent that the interrelationships between FAFH, nutrition and diet related diseases are complex. Therefore, there are significant gaps in our knowledge. In this study, a number of important research questions related to FAFH consumption were studied in order to provide a detailed understanding of FAFH purchase trends, nutrient demand trends, factors affecting these trends and to provide some idea of the possible effectiveness of proposed policy interventions in the area. In paper one of this study, a sample of Canadian FAFH purchases were analysed using a two stage demand model to examine the impact of industry advertising, households habit forming preferences and socio-demographic and economic variables. Given the unique method of restaurant categorization, results provide new and additional information of the impact of above variables in Canadian context. The second study examined the demand for selected nutrients in FAFH to understand factors affecting nutrient intake in FAFH foods focusing on chain restaurants. An innovative measure of nutrient content (nutrient density) was used in the analysis and study results provides interesting new information about nutrient consumption from chain restaurants in the FAFH market. The third study examined how some specific food industry changes in product formulations aimed at reducing trans-fatty acids (TFAs) could and have affected consumers overall diet quality and their demand for food away from home. This study provides some indications of effectiveness of the current trans-fat recommendations in Canada. In summary, this study is an empirical investigation of a number of questions related to Canadian FAFH consumption: What is the structure of the FAFH market in Canada? What are the households FAFH purchasing patterns? What is the impact of advertising and habit forming preferences and socio-economic and demographic factors on FAFH purchases? What are the nutrition profiles of the most popular menu items of chain restaurants? What are the factors affecting nutrient demand in FAFH foods? Would a specific food industry change in product formulation such as reducing TFAs have affect consumers overall diet quality and their demand for FAFH? In general, results from the three independent studies provide useful information to fill some of the gaps in our knowledge of FAFH consumption, especially on health and nutrition with implications for public policy. / Agricultural and Resource Economics