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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Encapsulating N-heterocyclic carbene complexes into biodegradable nanoparticles and the antimicrobial and antitumor effects

Robishaw, Nikki K. 14 September 2018 (has links)
No description available.
42

Overcoming therapeutic resistance in glioblastoma using novel electroporation-based therapies

Partridge, Brittanie R. 25 October 2022 (has links)
Glioblastoma (GBM) is the most common and deadliest of the malignant primary brain tumors in humans, with a reported 5-year survival rate of only 6.8% despite years of extensive research. Failure to improve local tumor control rates and overall patient outcome is attributed to GBM's inherent therapeutic resistance. Marked heterogeneity, extensive local invasion within the brain parenchyma, and profound immunosuppression within the tumor microenvironment (TME) are some of the unique features that drive GBM therapeutic resistance. Furthermore, tumor cells are sequestered behind the blood-brain barrier (BBB), limiting delivery of effective therapeutics and immune cell infiltration into the local tumor. Electroporation-based therapies, such as irreversible electroporation (IRE) and second generation, high-frequency IRE (H-FIRE) represent attractive alternative approaches to standard GBM therapy given their ability to induce transient BBB disruption (BBBD), achieve non-thermal tumor cell ablation and stimulate local and systemic anti-tumor immune responses without significant morbidity. The following work explores the use of H-FIRE to overcome GBM-induced therapeutic resistance and improve treatment success. Chapter 1 opens with an overview of GBM and known barriers to treatment success. Here, we emphasize the utility of spontaneous canine gliomas as an ideal translational model for investigations into novel treatment approaches. Chapter 2 introduces novel ablation methods (i.e. IRE/H-FIRE) capable of targeting treatment-resistant cancer stem cells. The focus of Chapter 3 is to highlight IRE applications in a variety of spontaneous tumor types. In Chapter 4, we investigate the feasibility and local immunologic response of percutaneous H-FIRE for treatment of primary liver tumors using a spontaneous canine hepatocellular carcinoma (HCC) model. In chapter 5, we characterize the mechanisms of H-FIRE-mediated BBBD in an in vivo healthy rodent model. In Chapter 6, we characterize the local and systemic immune responses to intracranial H-FIRE in rodent and canine glioma models to enhance the translational value of our work. Collectively, our work demonstrates the potential for H-FIRE to overcome therapeutic resistance in GBM, thereby supporting its use as a novel, alternative treatment approach to standard therapy. / Doctor of Philosophy / Glioblastoma (GBM) is the most common and deadliest form of primary brain cancer in humans, with only 6.8% of people surviving 5-years after their diagnosis. GBM is characterized by a number of unique features that make it resistant to standard treatments, such as surgery, radiation and chemotherapy. Examples include: (1) extensive invasion of tumor cells into the brain, making complete removal via surgery very difficult; (2) tumor cells are protected by a structure called the blood-brain barrier (BBB), which restricts the entry of most drugs (i.e. chemotherapy) and many immune cells, into the brain, thereby preventing them from reaching tumor cells; (3) tumor cells produce substances that block the immune system from being able to detect the tumor itself, which allows it to continue to grow undetected. High-frequency irreversible electroporation (H-FIRE) represents a new approach for the treatment of GBM. H-FIRE uses electric pulses to temporarily or permanently injure cell membranes without the use of heat, which allows for very precise treatment. The following work explores the ways in which H-FIRE can interfere with specific GBM features that drive its resistance to treatment. Here, we demonstrate that H-FIRE is capable of temporarily disrupting the BBB and characterize the mechanisms by which this occurs. This allows for drugs and immune cells within the blood to enter the brain and access the tumor cells, particularly those extending beyond the visible tumor mass and invading the brain. We also illustrate the potential for H-FIRE treatment within the brain to stimulate local and systemic immune responses by causing the release of proteins from injured cells. Similar to a vaccine, these proteins are recognized by the immune system, which becomes primed to help fight off cancer cells within the body. The end result is an anti-tumor immune response. Collectively, this work supports the use of H-FIRE as an alternative treatment approach to standard therapy for GBM given its potential to overcome certain causes of treatment resistance.
43

Chemical synthesis and biological evaluation of a NAD(P)H:quinone oxidoreductase-1-targeted tripartite quinone drug delivery system

Volpato, Milène, Abou-Zeid, N., Tanner, R.W., Glassbrook, L.T., Taylor, James P., Stratford, I.J., Loadman, Paul, Jaffar, M., Phillips, Roger M. January 2007 (has links)
No / NAD(P)H:quinone oxidoreductase-1 (NQO1) is a potential target for therapeutic intervention but attempts to exploit NQO1 using quinone-based bioreductive prodrugs have been largely compromised by toxicity to organs that inherently express high levels of NQO1. In an attempt to circumvent this problem, this study describes the development of a tripartite quinone-based drug delivery system, the ultimate objective of which is to release a targeted therapeutic agent following the reduction of a quinone "trigger" by NQO1. Molecular modeling of drug/NQO1 interactions were conducted prior to the synthesis of N-{4-[bis-(2-chloroethyl)-amino]-phenyl}-beta,beta,2,4,5-pentamethyl-3,6-dioxo-1,4-cyclohexadiene-1-propanamide (prodrug 1). Prodrug 1 is a good substrate for purified NQO1 (V(max) and K(m) values of 11.86 +/- 3.09 micromol/min/mg and 2.70 +/- 1.14 micromol/L, respectively) and liquid chromatography-mass spectrometry analysis of the metabolites generated showed that lactone 3 and aniline mustard 4 were generated in a time- and NQO1-dependent manner. Chemosensitivity studies showed that prodrug 1 is selectively toxic to cells that overexpress NQO1 under aerobic conditions, and comet assay analysis confirmed the presence of elevated interstrand cross-links in NQO1-rich compared with NQO1-deficient cells. Hypoxic sensitization (hypoxic cytotoxicity ratio = 15.8) was observed in T47D cells that overexpress cytochrome P450 reductase. In conclusion, the results of this study provide mechanistic proof of principle that a tripartite benzoquinone drug delivery system is enzymatically reduced to release an active therapeutic agent. Further development of this concept to fine-tune substrate specificity for specific reductases and/or the inclusion of alternative therapeutic agents is warranted.
44

Impacto dos medicamentos imunobiológicos e da doença coronária na evolução de pacientes com artrite reumatoide: uma análise de custo-efetividade / Impact of immunobiological drugs and coronary disease evolution of patients with rheumatoid arthritis: a cost-effectiveness analysis

Gomes, Rafael Kmiliauskis Santos 02 June 2017 (has links)
Introdução: Estudos epidemiológicos têm estabelecido que a artrite reumatoide está associada com um aumento de doença cardiovascular. A avaliação de anti-TNF sobre a redução do risco de infarto agudo do miocárdio e óbito por causa cardiovascular tem demonstrado resultados promissores. A avaliação econômica para esses desfechos ainda não está estabelecida. Objetivo: Realizar uma análise de custo efetividade de anti-TNF versus Dmards para evitar um caso novo de morbidade e óbito cardiovascular na artrite reumatoide. Método: Foi realizada uma análise de custo efetividade por meio do modelo de Markov, ciclo de transição de 6 meses e horizonte temporal de 30 anos sob perspectiva do sistema público de saúde do Brasil mensurado pela razão de custo efetividade incremental. Custo em Reais no ano de 2015 e efetividade em evitar um caso novo de doença coronariana isquêmica aguda e óbito cardiovascular. Resultados: O custo médio em 30 anos de Dmards e anti-TNF foi de R$ 14.291.105,28 e R$ 96.151.873,86, respectivamente. A efetividade incremental para doença arterial coronariana foi de 2,69 e consequente razão incremental de custo efetividade de R$ 30.527.502,27, enquanto para óbito cardiovascular a efetividade incremental foi de 1,33 casos evitados e uma razão incremental de custo efetividade de R$ 61.634.231,69. A análise univariada identificou que o parâmetro de maior impacto na razão incremental de custo efetividade de ambos os desfechos foi o medicamento anti-TNF. A análise de sensibilidade estabeleceu que, para atingir o valor de disposição a pagar por semestre para evitar um infarto agudo do miocárdio, o custo médio do anti-TNF deveria ser de R$ 1.337,47 ou diferença de incidência entre as estratégias de 0,032. Ainda, para evitar um óbito cardiovascular, o custo médio deveria ser de R$ 954,22 ou diferença de incidência de 0,071. Todas as análises realizadas estabeleceram uma relação desfavorável da estratégia do tratamento medicamentoso com anti-TNF. Conclusão: Os achados da análise de custo efetividade entre pacientes com artrite reumatoide para desfecho cardiovascular quando comparada a estratégia de tratamento medicamentoso de anti-TNF em relação à estratégia dominante com Dmards após os 6 primeiros meses de exposição aos medicamentos apontaram para uma relação desfavorável, ultrapassando o valor de disposição a pagar recomendado pelo Ministério da Saúde do Brasil no ano de 2015. Descritores: artrite reumatoide; doenças cardiovasculares; infarto do miocárdio; óbito; avaliação de custo-efetividade; anti fator de necrose tumoral; drogas anti-reumáticas modificadoras de doença. / Introduction: Epidemiological studies have established that rheumatoid arthritis is associated with an increase in cardiovascular disease. The evaluation of anti-TNF on the reduction of the risk of acute myocardial infarction and death due to cardiovascular causes has shown promising results. The economic evaluation for these outcomes is not yet established. Objective: To perform a cost-effectiveness analysis of anti-TNF versus Dmards to avoid a new case of cardiovascular morbidity and death in rheumatoid arthritis. Method: A cost effectiveness analysis was performed using the Markov model, a 6-month transition cycle and a 30-year time horizon under the perspective of the Brazilian public health system measured by the incremental cost-effectiveness ratio. Cost in Reais in the year 2015 and effectiveness in avoiding a new case of acute ischemic coronary disease and cardiovascular death. Results: The average cost in 30 years of Dmards and anti-TNF was R$ 14,291,105.28 and R$ 96,151,873.86, respectively. The incremental effectiveness for coronary artery disease was 2.69 and a consequent incremental cost-effectiveness ratio of R$ 30,527,502.27, while for cardiovascular death, incremental effectiveness was 1.33 cases avoided and an incremental cost-effectiveness ratio of R$ 61,634,231.69. The univariate analysis identified that the parameter of greatest impact in the incremental cost-effectiveness ratio of both outcomes was the anti-TNF drug. The sensitivity analysis established that the average cost of anti-TNF should be R$ 1,337.47 or incidence difference between strategies of 0.032 in order to reach the amount of willingness to pay per semester to avoid an acute myocardial infarction. Also, to avoid a cardiovascular death, the average cost should be R$ 954.22 or incidence difference of 0.071. All the analyzes carried out established an unfavorable relationship of the drug treatment strategy with anti-TNF. Conclusions: The findings of the cost-effectiveness economic analysis among individuals with rheumatoid arthritis for cardiovascular outcome when compared to the strategy of anti-TNF drug treatment compared to the dominant strategy with Dmards after the first 6 months of drug exposure pointed to an unfavorable relationship, surpassing the amount of willingness to pay recommended by the Ministry of Health of Brazil in the year 2015.
45

Évaluation concomitante des signatures fonctionnelles des réponses lymphocytaires T spécifiques des Antigènes Associés aux Tumeurs et des Cellules Tumorales Circulantes : Impact sur le pronostic des patients atteints de carcinome épidermoïde des voies aéro-digestives supérieures / Prognostic value of the concomitant evaluation of tumor-associated immune responses and circulating tumor cells in head and neck squamous cell carcinoma

Wu, Xianglei 02 June 2017 (has links)
Nous avons abordé dans l’ensemble de nos travaux deux paramètres importants pour l’immunomonitoring des patients atteints d’un cancer : les cellules tumorales circulantes (CTC) comme un indicateur de la « charge antigénique tumorale » et la réponse immune lymphocytaire T spécifique d’antigènes associés aux tumeurs (AAT). Nous avons évalué d’abord la valeur diagnostique et pronostique des CTC dans les cancers des voies aérodigestives supérieures (« HNSCC » en anglais) par une revue systématique et meta-analyse de la littérature. Les preuves actuelles identifient le test de détection de CTC comme un test extrêmement spécifique, mais de faible sensibilité dans les HNSCC. En outre, la présence de CTC indique une DFS (« disease free survival ») inférieure. Nous rapportons également pour la première fois un cas rare d’énumération extrêmement élevée de CTC détectées par le système CellSearch® chez un patient présentant un carcinome épidermoïde de la cavité buccale en utilisant. Le nombre absolu de CTC pourrait donc prédire une phase particulière de développement du cancer ainsi qu'une mauvaise survie, contribuant potentiellement à une prise en charge médicale personnalisée. De plus, nous décrivons une adaptation de la méthode CellSearch® qui nous avons développée pour détecter les cellules tumorales dans le liquide céphalo-rachidien de patients atteints de méningites carcinomateuses. Cette nouvelle approche permet une sensibilité nettement améliorée en comparaison avec la cytologie conventionnelle. La technologie CellSearch®, appliquée à des volumes limités des échantillons et permettant une augmentation du temps pré-analytique, pourrait ainsi avoir un grand intérêt dans le diagnostic de métastases leptoméningées chez les patients atteints d’un cancer d’origine épithéliale. Par une évaluation concomitante des CTC et des réponses lymphocytaires spécifiques aux AAT chez 24 patients avec HNSCC, nous avons trouvé que les CTC pourraient être un indicateur indépendant de la charge tumorale immunogène. L'absence de CTC, la présence de lymphocytes T spécifiques aux AAT, ou la combinaison de ceux-ci, étaient tous des paramètres montrant une tendance pour une meilleure survie globale ou une survie sans maladie. L’amplitude et les signatures fonctionnelles des lymphocytes T spécifiques aux AAT chez les patients atteints de HNSCC étaient associées à la présence de CTC. Ces résultats suggèrent qu’une évaluation concomitante de ces deux paramètres pourrait être plus informative sur le pronostic et potentiellement sur l’impact des traitements (notamment dans la perspective d’un traitement par des « immune checkpoints ») / We have evaluated herein two important parameters in the immunomonitoring of cancer patients: circulating tumor cells (CTC) as an indicator of “tumoral antigenic load” and tumor-associated antigens (TAA) specific T-cells. We firstly evaluated the diagnostic and prognostic value of CTC in Head and Neck Squamous Cell Carcinoma (HNSCC) by a systematic review and meta-analysis. We came to the conclusion that current evidence identifies the CTC detection test as an extremely specific but low sensitive test in HNSCC. In addition, the presence of CTC indicates a worse disease-free disease (DFS). Also, we report for the first time a rare case of extremely high enumeration of circulating tumor cells detected in a patient with squamous cell carcinoma of the oral cavity using the CellSearch® system. The absolute number of CTC could therefore predict a particular phase of cancer development as well as a poor survival, potentially contributing to personalized health. In addition, we describe an adaptation of the CellSearch® method that we have developed for detecting tumor cells in the cerebrospinal fluid of patients with carcinomatous meningitis. This new approach reaches a significantly improved sensitivity compared to conventional cytology. CellSearch® technology, applied to limited sample volumes and allowing an increased pre-analytical time, may be of great interest in the diagnosis of leptomeningeal metastases in patients with epithelial cancer. By a concomitant evaluation of CTC and TAA-specific lymphocyte responses in 24 HNSCC patients, we describe that CTC could be an independent indicator of immunogenic tumor burden. The absence of CTC, the presence of TAA-specific T-cells, or the combination of these, were all parameters showing a trend for a better overall survival or DFS. The amplitude and functional signatures of TAA-specific T-lymphocytes in patients with HNSCC were associated with the presence of CTC. These results suggest that a concomitant evaluation of these two parameters may be more pertinent for prognosis assessment as well as for treatment impact, especially in “checkpoint-inhibitors” new immunotherapies
46

Prognostický a prediktivní význam exprese kontrolních bodů imunitních reakcí u ovariálního karcinomu / The prognostic and predictive role of immune check point inhibitors in ovarian cancer patients

Raková, Jana January 2018 (has links)
Epithelial ovarian cancer is the sixth most common tumor disease among women and it is the leading cause of death from all types of gynecologic malignancies. The current standart of care consist of debulking surgery followed by platinum-taxane chemotherapy. Althought some patients benefit from the treatment, most eventually experience platinum-resistance and die from this disease. Immunotherapy based on application of immune checkpoint blockers represents a new treatment strategy in different cancer malignancies. However, emerging clinical data show only limited clinical efficacy of these agents in ovarian cancer patients with objective response rates of 10-15%. Therefore there is a strong need to identify a potential biomarkers, which allows to identify the group of patients, who will benefit the most from this costly treatment. The aim of my diploma thesis was to characterize the prognostic and predictive role of the immune checkpoints within the retrospective and prospective cohort of patients with high-grade serous ovarian cancer (HGSOC). Our study follows, that the expression of PD-L1 molecule and high frequencies of PD-1+ tumor infiltrating lymphocytes (TILs) in tumor microenviroment is significantly correlated with a better prognosis of patients with HGSOC. Moreover, PD-L1 and PD-1...
47

TRPM4, a non selective cation-permeable channel regulates Foxp3+ regulatory T cells suppressive function and survival trough modulating calcium influx / TRPM4, le canal cationique non-selective régule la fonction suppressive et la survie des lymphocytes T régulateurs Foxp3+ en régulant l'influx calcique

Yang, Heng 05 October 2012 (has links)
TRPM4, un canal cationique non-sélective activé par le Ca2+ intracellulaire, est un acteur moléculaire important impliqué de la régulation du signal calcique et l’activation des lymphocytes T conventionnels mais son rôle dans la fonction des lymphocytes T régulateurs (Tregs Foxp3+) reste inconnu. Dans un modèle de souris transgéniques dans lequel le gène Trpm4 a été sélectivement invalidé dans la population des Tregs Foxp3+ (souris Foxp3(YFP)Cre+Trpm4flox/flox), nous avons démontré dans différents modèles in vivo d’inflammation aiguë et chronique que TRPM4 contrôle la fonction suppressive et la mort de ces cellules. Dans le modèle de fibrosarcome induit par le méthylcholanthrène (3-MCA) ou implanté (modèle MCA205), dans lequel le rôle des Tregs est documenté, l’absence de fonction de TRPM4 induit une diminution significative de l’incidence et de la croissance tumorale. Dans l’environnent inflammatoire chronique et hypoxique de ces tumeurs, l’expression de TRPM4 protège les Tregs infiltrant la tumeur de la mort cellulaire induit par l’ATP extracellulaire et stimule ainsi le développent et la progression tumorale. L’absence d’expression de TRPM4 dans les Tregs stimule la réponse anti-tumorale médiée par l’IFNg et induit la régression des tumeurs. En conclusion, en inhibant l’entrée de Ca2+ extracellulaire, TRPM4 régule négativement les fonctions suppressives des Tregs et protège ces cellules de la mort cellulaire induite par l’activation. / TRPM4, a Ca2+-activated non-selective cation ion channel is an important regulator of Ca2+ signaling and cell activation in conventional T cells, but its role in Foxp3+ Tregs function remains unknown. Using a model in which Trpm4 gene was selectively invalidated in Foxp3+ Tregs population (Foxp3(YFP)Cre+Trpm4flox/flox mice) we have shown in different in vivo models of acute and chronic inflammation that TRPM4 is an important regulator of Tregs functions and survival. In a model of primary carcinogenesis induced by methylcholantrene (3-MCA) or implanted fibrosarcoma (MCA205 model), in which Tregs role has been documented, lack of TRPM4 expression and function induced significantly decreased incidence and tumor growth. We found that within chronic inflammatory and hypoxic tumor microenvironment, TRPM4 protected Tregs from ATP-induced cell death and therefore promoted tumor initiation and progression. In contrast, TRPM4 deficiency in Tregs favored IFN-g-mediated spontaneous anti-tumor immune response. Thus, through inhibiting Ca2+ influx, TRPM4 acts as a negative modulator of Tregs suppressive functions and protects Tregs from activation-induced cell death.
48

Clinical and Experimental Studies in Peritoneal Metastases from Gastric Cancer

Hultman, Bo January 2013 (has links)
Gastric cancer (GC) is one of leading causes of death in the world, and peritoneal metastases (PM) are a major site of recurrence. PM from GC implies a poor prognosis, with median overall survival (mOS) approximately 3 months and no survival at five years. The aims of this thesis were to explore the incidence and evaluate prognostic factors for mOS of PM from GC in a defined population; to investigate the outcome of a new multimodal treatment; to analyse the treatment costs, and to investigate differences in drug sensitivity between individual patient samples and between various tumours. The incidence of loco-regional advanced GC was 3.8 per 100,000 person-years. Synchronous loco-regional GC in combination with synchronous distant metastasis was a negative prognostic factor while chemotherapy and good performance status, and radiotherapy plus chemotherapy were positive prognostic factors . There were no significant differences in mOS for the group of patients included during the period 2000-2004 versus 2005-2009, and this lack of improvement in mOS during the past decade justifies new treatment approaches. In a Phase II study of patients treated with neoadjuvant systemic chemotherapy followed by cytoreductive surgery + hyperthermic intraperitoneal chemotherapy, mOS was 14.3 months and for patients with macroscopically radical surgery mOS was 19.1 months. The mean overall cost of the loco-regional treatment was $145,700 compared to $59,300 with systemic chemotherapy treatment. In an ex vivo chemo-sensitivity test, it was determined that GC samples were equivalent to colorectal cancer in chemo-sensitivity to standard drugs and targeted drugs, whereas ovarian cancer samples were more sensitive. The individual GC samples varied considerably in sensitivity to increasing concentrations of the drugs, arguing for individualized drug selection. The incidence of loco-regional advanced GC was more common than previously reported and there were no improvements in mOS over the past decade. The mOS for patients with neoadjuvant systemic chemotherapy followed by macroscopically radical cytoreductive surgery + hyperthermic intraperitoneal chemotherapy was better than in recent reports on treatment with systemic chemotherapy. Treatment of advanced GC patients is costly irrespective of treatment modality. The GC samples varied considerably between individuals in terms of sensitivity to increasing concentrations of the drugs and were comparable to colorectal cancer in chemo-sensitivity.
49

THE CRITICAL ROLE OF CD4+ TH CELLS IN CD8+ CTL RESPONSES AND ANTI-TUMOR IMMUNITY

2012 April 1900 (has links)
The goal of this body of research was to elucidate the mechanism by which CD4+ T cells provide help for CD8+ cytotoxic T lymphocyte (CTL) responses in different immunization types. The establishment of diseases, such as chronic infections and cancers, is attributed to severe loss of or dysfunctions of CD4+ T cells. Even in acute infections, CD4+ T cell deficiency leads to poor memory responses. While the role of CD4+ T cells is being increasingly appreciated in these diseases, the timing and nature of CD4+ T help and associated molecular mechanisms are not completely understood. Growing evidence suggests that, depending on the type of infections or immunizations, the requirements of CD4+ T cells can vary for optimal CD8+ CTL responses. In order to understand the modulatory effects of CD4+ T cells for optimal CD8+ CTL responses, two distinct immunization types were chosen. These include: 1) non-inflammatory dendritic cell (DC) immunization, which fails to provide inflammatory/danger signals; and 2) inflammatory adenovirus (AdV) immunization, which provides profound inflammatory/danger signals. This allowed us to study CD4+ T cell’s participation under different inflammatory conditions. The studies described in Chapters 2 and 3 of this thesis were performed to further understand the concept of how CD4+ T cells mediate optimal CD8+ CTL responses. This has been called the “new dynamic model of CD4+ T helper – antigen (Ag)-presenting cells (Th-APCs),” proposed in 2005 by our laboratory. The study described in Chapter 2 shows that Th-APCs participate not only in augmenting CTL-mediated immune responses, perhaps during early phase, but also in regulating cellular immunity, perhaps during a later phase. Through enhanced IL-2, CD80 and CD40L singnaling, and weaker peptideMHC I (pMHC) signaling, Th-APCs stimulated naïve CD8+ T cells to differentiate into effector CTLs, capable of developing into, central memory CTLs. Th-APC-stimulated CD4+ T cells behaved like Th cells in function, augmenting the overall magnitude of CTL responses. In contrast, Th-APCs were able to kill DCs and other Th-APCs, predominantly through perforin-mediated pathway. The experiments described in Chapter 3 revealed a novel co-operative role of cognate Th-CTL interactions, contrary to previously known immune-regulatory mechanisms among Th-Th or CTL-CTL interactions. In our experiments, Th cells, via CD40L, IL-2, and acquired pMHC-I signaling, enhanced CTL survival and transition into functional memory CTLs. Moreover, RT-PCR, flow cytometry and western blot analysis demonstrate that increased survival of Th cell-helped CTLs is matched with enhanced Akt1/NF-κB activation, down-regulation of FasL and TRAIL, and altered expression profiles with up-regulation of prosurvival (Bcl-2) and down-regulation of proapoptotic (NFATc1, Bcl-10, Casp-3, Casp-4, Casp-7) genes/ molecules. Finally, helped CTLs were also able to induce protection against highly metastasizing tumor challenge, explaining why memory CTLs generated under cognate Th1’s help show survival and recall advantages. The studies in Chapter 4 showed how the precursor frequency (PF) of CD8+ T cells impacts CD4+ T helper requirements for functional CTL responses. At endogenous PF, CD4+ T helper signals were necessary for both primary and memory CTL responses. At increased PF, CD4+ T help, and its CD40L but not IL-2 signal became dispensable for primary CTL responses. In contrast, memory CTL responses required CD4+ T cell signals, largely in the form of IL-2 and CD40L. Thus, these results could impact the development of novel immunotherapy against cancers, since their efficacy would be determined in part by CD4+ T help and CD8+ T cell PF. Finally, the study showed the importance of CD4+ T cells for multiple phases of AdV transgene product-specific CTL responses. These include: a) cognate CD4+ T cells enhanced CTL responses via IL-2 and CD40L signaling during primary, maintenance and memory phases; b) polyclonal CD4+ T environment enhanced the survival of AdV-specific CTL survival, partially explaining protracted CTL contraction phase; and c) during the recall phase, the CD4+ T environment, particularly memory CD4+ T cells, considerably enhanced not only helped, but also unhelped, memory CTL expansion. Thus, these results suggest the participation of both cognate and polyclonal CD4+ T cells for multiple phases of AdV-specific CTLs. Taken together, the current work delineated the critical roles of CD4+ T cells in different stages of CTL responses and in the development of anti-tumor immunity. The results presented here will significantly advance our current understanding of immunity to cancers, autoimmunity and chronic infections, since pathogenesis of these diseases is largely determined by CD4+ T helper functions. As most immunization procedures use the principle that is based on functions of memory cells, the knowledge gained from this work will also have a major impact on designing vaccines against intractable diseases, including cancers and chronic infections. Moreover, in advanced tumors, vaccines developed using this knowledge may act synergistically with other cancer treatments such as irradiation, chemotherapy and microsurgery, minimizing their side effects and prolonging the lives of patients.
50

Impacto dos medicamentos imunobiológicos e da doença coronária na evolução de pacientes com artrite reumatoide: uma análise de custo-efetividade / Impact of immunobiological drugs and coronary disease evolution of patients with rheumatoid arthritis: a cost-effectiveness analysis

Rafael Kmiliauskis Santos Gomes 02 June 2017 (has links)
Introdução: Estudos epidemiológicos têm estabelecido que a artrite reumatoide está associada com um aumento de doença cardiovascular. A avaliação de anti-TNF sobre a redução do risco de infarto agudo do miocárdio e óbito por causa cardiovascular tem demonstrado resultados promissores. A avaliação econômica para esses desfechos ainda não está estabelecida. Objetivo: Realizar uma análise de custo efetividade de anti-TNF versus Dmards para evitar um caso novo de morbidade e óbito cardiovascular na artrite reumatoide. Método: Foi realizada uma análise de custo efetividade por meio do modelo de Markov, ciclo de transição de 6 meses e horizonte temporal de 30 anos sob perspectiva do sistema público de saúde do Brasil mensurado pela razão de custo efetividade incremental. Custo em Reais no ano de 2015 e efetividade em evitar um caso novo de doença coronariana isquêmica aguda e óbito cardiovascular. Resultados: O custo médio em 30 anos de Dmards e anti-TNF foi de R$ 14.291.105,28 e R$ 96.151.873,86, respectivamente. A efetividade incremental para doença arterial coronariana foi de 2,69 e consequente razão incremental de custo efetividade de R$ 30.527.502,27, enquanto para óbito cardiovascular a efetividade incremental foi de 1,33 casos evitados e uma razão incremental de custo efetividade de R$ 61.634.231,69. A análise univariada identificou que o parâmetro de maior impacto na razão incremental de custo efetividade de ambos os desfechos foi o medicamento anti-TNF. A análise de sensibilidade estabeleceu que, para atingir o valor de disposição a pagar por semestre para evitar um infarto agudo do miocárdio, o custo médio do anti-TNF deveria ser de R$ 1.337,47 ou diferença de incidência entre as estratégias de 0,032. Ainda, para evitar um óbito cardiovascular, o custo médio deveria ser de R$ 954,22 ou diferença de incidência de 0,071. Todas as análises realizadas estabeleceram uma relação desfavorável da estratégia do tratamento medicamentoso com anti-TNF. Conclusão: Os achados da análise de custo efetividade entre pacientes com artrite reumatoide para desfecho cardiovascular quando comparada a estratégia de tratamento medicamentoso de anti-TNF em relação à estratégia dominante com Dmards após os 6 primeiros meses de exposição aos medicamentos apontaram para uma relação desfavorável, ultrapassando o valor de disposição a pagar recomendado pelo Ministério da Saúde do Brasil no ano de 2015. Descritores: artrite reumatoide; doenças cardiovasculares; infarto do miocárdio; óbito; avaliação de custo-efetividade; anti fator de necrose tumoral; drogas anti-reumáticas modificadoras de doença. / Introduction: Epidemiological studies have established that rheumatoid arthritis is associated with an increase in cardiovascular disease. The evaluation of anti-TNF on the reduction of the risk of acute myocardial infarction and death due to cardiovascular causes has shown promising results. The economic evaluation for these outcomes is not yet established. Objective: To perform a cost-effectiveness analysis of anti-TNF versus Dmards to avoid a new case of cardiovascular morbidity and death in rheumatoid arthritis. Method: A cost effectiveness analysis was performed using the Markov model, a 6-month transition cycle and a 30-year time horizon under the perspective of the Brazilian public health system measured by the incremental cost-effectiveness ratio. Cost in Reais in the year 2015 and effectiveness in avoiding a new case of acute ischemic coronary disease and cardiovascular death. Results: The average cost in 30 years of Dmards and anti-TNF was R$ 14,291,105.28 and R$ 96,151,873.86, respectively. The incremental effectiveness for coronary artery disease was 2.69 and a consequent incremental cost-effectiveness ratio of R$ 30,527,502.27, while for cardiovascular death, incremental effectiveness was 1.33 cases avoided and an incremental cost-effectiveness ratio of R$ 61,634,231.69. The univariate analysis identified that the parameter of greatest impact in the incremental cost-effectiveness ratio of both outcomes was the anti-TNF drug. The sensitivity analysis established that the average cost of anti-TNF should be R$ 1,337.47 or incidence difference between strategies of 0.032 in order to reach the amount of willingness to pay per semester to avoid an acute myocardial infarction. Also, to avoid a cardiovascular death, the average cost should be R$ 954.22 or incidence difference of 0.071. All the analyzes carried out established an unfavorable relationship of the drug treatment strategy with anti-TNF. Conclusions: The findings of the cost-effectiveness economic analysis among individuals with rheumatoid arthritis for cardiovascular outcome when compared to the strategy of anti-TNF drug treatment compared to the dominant strategy with Dmards after the first 6 months of drug exposure pointed to an unfavorable relationship, surpassing the amount of willingness to pay recommended by the Ministry of Health of Brazil in the year 2015.

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