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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

Breaking the Senescence: Inhibition of ATM Allows S9 Cells to Re-Enter Cell Cycle

January 2011 (has links)
abstract: The Philadelphia chromosome in humans, is on oncogenic translocation between chromosomes 9 and 22 that gives rise to the fusion protein BCR-Abl. This protein is constitutively active resulting in rapid and uncontrolled cell growth in affected cells. The BCR-Abl protein is the hallmark feature of chronic myeloid leukemia (CML) and is seen in Philadelphia-positive (Ph+) acute lymphoblastic leukemia (ALL) cases. Currently, the first line of treatment is the Abl specific inhibitor Imatinib. Some patients will, however, develop resistance to Imatinib. Research has shown how transformation of progenitor B cells with v-Abl, an oncogene expressed by the Abelson murine leukemia virus, causes rapid proliferation, prevents further differentiation and produces a potentially malignant transformation. We have used progenitor B cells transformed with a temperature-sensitive form of the v-Abl protein that allows us to inactivate or re-activate v-Abl by shifting the incubation temperature. We are trying to use this line as a model to study both the progression from pre-malignancy to malignancy in CML and Imatinib resistance in Ph+ ALL and CML. These progenitor B cells, once v-Abl is reactivated, in most cases, will not return to their natural cell cycle. In this they resemble Ph+ ALL and CML under Imatinib treatment. With some manipulation these cells can break this prolonged G1 arrested phenotype and become a malignant cell line and resistant to Imatinib treatment. Cellular senescence can be a complicated process requiring inter-play between a variety of players. It serves as an alternate option to apoptosis, in that the cell loses proliferative potential, but does not die. Treatment with some cancer therapeutics will induce senescence in some cancers. Such is the case with Imatinib treatment of CML and Ph+ ALL. By using the S9 cell line we have been able to explore the possible routes for breaking of prolonged G1 arrest in these Ph+ leukemias. We inhibited the DNA damage sensor protein ataxia telangiectasia mutated (ATM) and found that prolonged G1 arrest in our S9 cells was broken. While previous research has suggested that the DNA damage sensor protein ataxia-telangiectasia mutated (ATM) has little impact in CML, our research indicates that ATM may play a role in either senescence induction or release. / Dissertation/Thesis / M.S. Microbiology 2011
42

ANÁLISE DO CUSTO DE MEDICAMENTOS QUIMIOTERÁPICOS, POR MEIO DE MODELOS ARIMA - ARCH / ANALYSIS OF THE COST OF CHEMOTHERAPEUTIC DRUGS BY MEANS OF ARIMA MODELS - ARCH

Almeida, Silvana Gonçalves de 15 August 2011 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Today's medical treatments are becoming more expensive, in view of this plan and control costs are mechanisms that can ensure the survival of hospitals. The present study analyzed the cost of medications relevant financial, between January 2003 and November 2010, at University Hospital of Santa Maria. Since not all items have the same degree of importance, the drugs were classified by the ABC method which provided work with capecitabine and imatinib, the total cost of these drugs in 2010, representing about 18% compared to total expenditure on drugs and materials. The models found for the series of the cost of capecitabine and imatinib were ARIMA (0,1,1)-ARCH (1) and ARIMA (1,1,0)-ARCH (1), respectively. These models were used to analyze the behavior of the series under study and make predictions in order to assist hospital managers in decision making in hospital inventory management. / Atualmente os tratamentos médicos estão cada vez mais caros, em vista disso planejar e controlar custos são mecanismos que podem garantir a sobrevivência das instituições hospitalares. O presente estudo analisou o custo com medicamentos de relevância financeira, entre janeiro de 2003 e novembro de 2010, no Hospital Universitário de Santa Maria. Como nem todos os itens têm o mesmo grau de importância, os medicamentos foram classificados pelo método ABC o que proporcionou trabalhar com a Imatinibe e Capecitabina, cujo custo total em 2010 destes medicamentos, representou cerca de 18% em relação ao gasto total com medicamentos e materiais. Os modelos encontrados para as séries do custo de Imatinibe e Capecitabina foram, ARIMA(0,1,1)-ARCH(1) e ARIMA(1,1,0)-ARCH(1), respectivamente. Tais modelos foram utilizados para analisar o comportamento das séries em estudo e realizar previsões com o objetivo de auxiliar os gestores hospitalares nas tomadas de decisões no gerenciamento de estoque hospitalar.
43

Expressão dos genes ABCG2 e SCLO1A2 e sua relação com a resposta ao mesilato de imatinibe em pacientes com leucemia mieloide crônica / Gene Expression of ABCG2 and SCLO1A2 and its relationship with response to imatinib mesylate in patients with chronic myeloid leukemia

Luciene Terezina de Lima 24 February 2012 (has links)
A introdução do Mesilato de Imatinibe (MI) como primeiro inibidor específico de BCR-ABL1 na prática clínica revolucionou o tratamento da Leucemia Mieloide Crônica (LMC), tornando-se a terapia padrão para o tratamento desta doença. Porém, cerca de 30% dos pacientes com LMC não respondem à terapia com MI e um número substancial destes casos de resistência não tem causa conhecida. O MI interage com transportadores de membrana ABCG2 e SLCO1A2. Este estudo teve como objetivo investigar a relação da expressão gênica de ABCG2 e de SLCO1A2 com marcadores de resposta ao tratamento com MI, em indivíduos com LMC e avaliar a influência dos polimorfismos ABCG2 c.421C>A e ABCG2 c.-19-99G>A na resposta ao MI. Foram incluídos 118 pacientes com LMC os quais foram classificados em dois grupos: Grupo Respondedor, constituído por 70 pacientes com resposta citogenética completa com a dose padrão de MI (400 mg/dia) por até 18 meses e, Grupo não Respondedor constituído por 48 pacientes sem resposta citogenética completa à dose inicial de 400 mg/dia de MI ou que perderam esta resposta ao longo do tratamento e foram reescalonados para doses de 600 ou 800 mg/dia. A resposta ao tratamento foi avaliada segundo os critérios da European LeukemiaNet. Foram excluídos pacientes com alterações citogenéticas diferentes do cromossomo Ph e mutações no gene BCR-ABL1. Amostras de sangue periférico foram utilizadas para: extração do RNA total para quantificação dos transcritos BCR-ABL1 e expressão gênica de ABCG2 e SLCO1A2; extração de DNA e análise citogenética de banda G. A expressão do gene ABCG2 e SLCO1A2 e as análises dos polimorfismos foram feitas por PCR em tempo real. A expressão de ABCG2 foi maior no grupo de não respondedores ao MI (P=0,028). Este resultado foi influenciado pelos pacientes com resistência primária (N= 34 P=0,029), mas não pelos que apresentaram resistência secundária (N=14 P=0,249) quando comparado com respondedores (N=70). A elevada expressão do gene ABCG2 foi também associada àqueles pacientes que não tiveram resposta molecular maior (número de transcritos BCR-ABL1 ≤ 0,1%) (P=0,027) quando todos os pacientes foram analisados. O gene estudado não foi associado com a resposta molecular completa (número de transcritos BCR-ABL1 ≤ 0,032%). Com relação ao gene SLCO1A2 não foi possível determinar sua expressão devido à baixa concentração do RNA obtido. Os polimorfismos c.421C>A e c.-19-99G>A não foram associados com a expressão do gene ABCG2 e a resposta ao MI. A RMC (no grupo de respondedores) foi associada com o genótipo 421CC e houve tendência a maior frequencia de portadores do genótipo -19-99GG neste mesmo grupo. Portadores do genótipo -19-99AA apresentaram tendência ao risco de ter LMC. Os resultados deste estudo nos permitem concluir que a maior expressão de ABCG2 está associada com a resistência primária ao MI podendo então ser um mediador da resistência ao MI. Os polimorfismos do gene ABCG2 não influenciaram na expressão gênica de ABCG2, mas impactaram na RMC no grupo respondedor ao MI. / The introduction of imatinib mesylate (IM) as the first specific inhibitor of BCR-ABL1 in clinical practice has revolutionized the treatment of chronic myeloid leukemia (CML), becoming the standard therapy for this disease. However, about 20% of CML patients do not respond to therapy with IM and a substantial number of these cases of resistance have no known cause. The MI interacts with membrane transporters ABCG2 and SLCO1A2. The aim of this study was to investigate the relationship of ABCG2 and SLCO1A2 gene expression with markers of response to MI in individuals with CML and evaluate the influence of polymorphisms ABCG2 c.421C> A and c. ABCG2-19-99G> A in response to the MI. One hundred and eighteen patients in chronic phase of CML were studied and classified in two groups: Responder Group comprised 70 patients who had a complete cytogenetic response within 18 months of treatment. The non-responder group comprised 48 patients who did not have a complete cytogenetic response with the initial dose (400 mg/day) of IM or who relapsed during treatment and were submitted to higher doses of 600 or 800 mg/day. Criteria of failed response to treatment were established by European LeukemiaNet. Patients with cytogenetic patterns other than the Philadelphia chromosome and patients with mutations in the BCR-ABL1 gene were excluded from this study. Blood samples were obtained for: total RNA extraction for quantification of BCR-ABL1 and gene expression of ABCG2 and SLCO1A2; genomic DNA extraction and band G cytogenetic analysis. The gene expression and the analysis of the polymorphisms were performed by real time PCR. Expression of ABCG2 in non-responder group was higher than in responder group (P=0.028). This result was influenced by patients with primary resistance (n= 34 P=0.029) but not secondary resistance (n=14 P=0.249) when compared with responders (n=70). The higher expression of ABCG2 gene was also associated with those patients who had major molecular response (number of BCR-ABL1 . 0.1%) (P=0.027) when all patients were analyzed. The studied gene was not associated with the complete molecular response (number of BCR-ABL1 .0.0032). Regarding to the gene SLCO1A2 was not possible to determine its expression due to low concentration of RNA obtained. The c.421C>A e c.-19-99G>A were not associated neither with the ABCG2 gene expression and MI response. CMR in responders group was associated with the 421CC genotype ant there was a trend for higher frequency of carriers of genotype -19-99GG in the same group. Carriers of 19-99AA genotype tended to the risk of having CML. The results of this study allow us to conclude that the higher expression of ABCG2 is associated with primary resistance to IM and may be a mediator of resistance to IM. The ABCG2 polymorphisms did not influence the gene expression of ABCG2 but impacted in CMR of the responders to IM.
44

Estudo da expressão dos genes ABCB1 e SLC22A1 e sua relação com marcadores de  resposta ao mesilato de imatinibe em pacientes com leucemia mieloide crônica / Study of the expression of SLC22A1 and ABCB1 genes and their relationship with markers of response to imatinib mesylate in patients with chronic myeloid leukemia

Douglas Vivona 19 February 2014 (has links)
A leucemia mieloide crônica (LMC) é uma expansão clonal da célula tronco hematopoética, traduzindo-se por hiperplasia mieloide, leucocitose, neutrofilia, basofilia e esplenomegalia. O cromossomo Filadélfia é característico da doença, sendo produto da translocação t(9:22)(q34;q11), resultando na fusão dos genes ABL e BCR. Esta fusão gera um gene híbrido que codifica uma proteína com elevada atividade tirosinoquinase e tem um papel central na patogenia da LMC. O mesilato de imatinibe (MI) é um derivado da fenilaminopirimidina que inibe a proteína tirosinoquinase BCR-ABL1 in vitro e in vivo. O MI interage com transportadores de membrana de influxo, como o organic carion solute carrier 22 ,member 1 (SLC22A1,hOCT1); e de efluxo, como ATP binding cassette B1 (ABCB1, MDR1, P-gp). Os polimorfismos ABCB1 c.1236C>T, C.3435C>T e c.2677G>T/A têm sido associados com a alteração da função da P-gp. Este estudo teve por objetivo investigar a relação da expressão do RNAm de ABCB1 e SLC22A1 com marcadores de resposta ao tratamento com MI e avaliar a atividade funcional da P-gp em células mononucleares de pacientes com diferentes haplótipos para os polimorfismos ABCB1 c.1236C>T, c.3435C>T e c.2677G>T/A. Foram incluídos 118 pacientes com LMC para o estudo da expressão do RNAm de SLC22A1 e ABCB1 e para o estudo da atividade da P-gp foram selecionados 28 pacientes de acordo com os haplótipos dos polimorfismos ABCB1 c.1236C>T, c.3435C>T e c.2677G>T/A. Para o estudo da expressão do RNAm de SLC22A1 e ABCB1 foram constituídos dois grupos: Grupo 1 com 70 pacientes com resposta citogenética completa com a dose padrão de MI (400 mg/dia de MI) em até 18 meses e, Grupo 2 com 48 pacientes sem resposta citogenética completa com a dose inicial de 400 mg/dia de MI ou que perderam esta resposta ao longo do tratamento. Para o estudo da atividade funcional da P-gp, dos 118 pacientes incluídos, foram selecionados 10 pacientes que apresentaram o haplótipo 1236CC/3435CC/2677GG, 10 pacientes que apresentaram o haplótipo 1236CT/3435CT/2677GT e 8 pacientes que apresentaram o haplótipo 1236TT/3435TT/2677TT. A resposta ao tratamento foi avaliada segundo os critérios da European LeukemiaNet. Amostras de sangue foram obtidas para: quantificação de BCR-ABL1, extração do RNAm total, análise citogenética de banda G, dosagem da concentração plasmática de MI e análise da atividade e expressão da P-gp. A análise da expressão dos genes ABCB1 e SLC22A1 foi feita por PCR em tempo real, a análise da atividade e expressão da P-gp foram feitas por citometria de fluxo e a dosagem da concentração plasmática de MI foi realizada por eletroforese capilar. Resultados: A expressão de ABCB1 e SLC22A1 foi analisada nos 118 pacientes incluídos e foi similar entre os grupos de resposta. A elevada expressão do gene SLC22A1 foi associada àqueles pacientes que alcançaram a resposta molecular maior (RMM) no grupo respondedor (P=0,009). Não houve associação entre a expressão de ABCB1 e a resposta ao MI. Nenhum dos genes foi associado à resposta molecular completa (RMC). No estudo da atividade da P-gp foi observada uma maior atividade nos pacientes que apresentavam o haplótipo 1236CC/3435CC/2677GG quando comparado àqueles que possuíam o haplótipo com alelo mutado. Não houve diferença na expressão do RNAm dos genes SLC22A1 e ABCB1, expressão da P-gp e concentração plasmástica de MI entre os grupos de haplótipos. Os pacientes que não alcançaram a RMM apresentaram uma maior taxa de efluxo mediado pela P-gp quando comparado aos indivíduos que alcançaram esta resposta (64,7% vs. 45,7%; P=0,001). Os indivíduos que alcançaram a RMM e RMC apresentaram maior mediana de expressão do gene SLC22A1. Os pacientes sem RMM apresentaram menor concentração plasmática de MI quando comparados aos que alcançaram esta resposta (0,51 µg/mL vs. 1,42 µg/mL; P=0,001). Não foi observada associação entre a concentração plasmática de MI e a RMC. Em conclusão os pacientes respondedores a dose padrão de 400mg/dia de MI e que alcançaram a RMM apresentam maior expressão de RNAm de SLC22A1 e os portadores dos haplótipos 1236CT/3435CT/2677GT e 1236TT/3435TT/2677TT exibem menor efluxo mediado pela P-gp apresentando maior frequência de RMM. / Chronic myeloid leukemia (CML) is a clonal expansion of hematopoietic stem cell, translating into myeloid hyperplasia, leukocytosis, neutrophilia, basophilia and splenomegaly. The Philadelphia chromosome is characteristic of the disease, being the product of the translocation t(9:22)( q34,q11), resulting in the fusion of the BCR and ABL genes. This fusion generates a hybrid gene that encodes a protein with elevated tyrosine kinase activity and plays a central role in the pathogenesis of CML. Imatinib mesylate (IM) is a derivative of fenilaminopirimidine that inhibits BCR-ABL1 fusion protein tyrosine kinase in vitro and in vivo. IM interacts with uptake membrane transporters, such as cation organic solute carrier 22, member 1 (SLC22A1, hOCT1) and efflux as ATP binding cassette B1 (ABCB1, MDR1,P-gp). ABCB1 polymorphisms c.1236C>T,c.3435C>T and c.2677G>T/A have been associated with altered function of P-gp. This study aimed to investigate the relationship between mRNA expression of ABCB1 and SLC22A1 with markers of response to treatment with IM and evaluate the functional activity of P-gp in mononuclear cells of patients with different haplotypes for ABCB1 c.1236C>T, c.3435C>T and c.2677G>T/A polymorphisms. This study included 118 patients with CML to study the mRNA expression of SLC22A1 and ABCB1 and to study the P-gp activity, 28 patients were selected according to the haplotypes of ABCB1 c.1236C>T, c.3435C>T and c.2677G>T/A polymorphisms. To study the mRNA expression of SLC22A1 and ABCB1, two groups were constituted: Group 1 with 70 patients with a complete cytogenetic response with standard-dose IM (400 mg/day) in 18 months, and group 2 with 48 patients without complete cytogenetic response with the initial dose of IM (400 mg/day) or have lost this response during treatment. To study the P-gp functional activity, 10 patients with haplotype 1236CC/3435CC/2677GG, 10 patients with haplotype 1236CT/3435CT/2677GT and 8 patients with haplotype 1236TT/3435TT/2677TT were enrolled. Treatment response was assessed according to European LeukemiaNet criteria. Blood samples were obtained for: quantification of BCR-ABL1, mRNA extraction, G band cytogenetic analysis, measurement of IM plasma levels and P-gp activity and expression. The ABCB1 and SLC22A1 gene expression analysis was made by real-time PCR, analysis of P-gp activity and protein expression were performed by flow cytometry and determination of plasma Levels of IM was performed by capillary electrophoresis. Results: Expression of ABCB1 and SLC22A1 were analyzed in 118 patients included and was similar between the response groups. Higher expression of the SLC22A1 gene was associated with those patients who achieved a major molecular response (MMR) in the responder group (P=0.009). There was no association between ABCB1 expression and IM response. None of the studied genes was associated with complete molecular response (CMR). In the study of P-gp activity we observed greater activity mediated by P-gp in patients with 1236CC/3435CC/2677GG haplotype when compared to those with the mutated allele. There was no difference in mRNA expression of SLC22A1 and ABCB1 genes, P-gp expression and IM plasma levels between haplotypes groups. Patients who did not achieve MMR showed a higher rate of efflux mediated by P-gp compared to individuals who did achieve this response (64.7% vs. 45.7%, P=0.001). Individuals who achieved MMR and CMR had higher median of SLC22A1 expression. Patients without MMR had lower IM plasma levels compared with those who achieved this response (0.51 µg/mL vs. 1.42 µg/mL, P=0.001). No association was observed between IM plasma levels and CMR. In conclusion patients responders to standard dose of IM (400 mg/day) and who achieved MMR have higher SLC22A1 mRNA expression and the carriers of 1236CT/3435CT/2677GT 1236TT/3435TT/2677TT haplotypes exhibit lower efflux mediated by P-gp with higher frequency of MMR.
45

The Role of Calcium in the Regulation of Pathological Hypertrophy

Barr, Larry A. January 2014 (has links)
Pathological hypertrophy leads to cardiac dysfunction and heart failure. It is not clearly defined how this process occurs in the cardiomyocyte, or how the pathology can be effectively treated. There are numerous processes that lead to pathological hypertrophy. We developed two models to study pathological hypertrophy and the role that Ca2+ plays. In one model, we administered clinical doses of the leukemia therapeutic drug imatinib to neonatal ventricular cardiomyocytes. This drug has recently been found to be cardiotoxic, and we set out to understand if Ca2+ is involved. In the second model, we developed mice with overexpression of the Ca2+ entrance channel, the L-type calcium channel (LTCC), which leads to pathological hypertrophy over time. We instituted a chronic exercise regimen on these mice to learn if physiological hypertrophy can ameliorate detrimental aspects of pathological hypertrophy. After cardiomyocytes were treated with imatinib, they expressed enhanced Ca2+ activity. Levels of atrial natriuretic peptide (ANP) were up, signifying pathological hypertrophy. We determined that Ca2+ was activating Calcineurin, leading to translocation of nuclear factor of activated T-cells (NFAT) into the nucleus, resulting in hypertrophy. This activity was blocked by Ca2+ and Calcineurin inhibitors. We concluded that imatinib causes Ca2+ induced pathological hypertrophy. When mice with LTCC overexpression were exercised, they exhibited enhanced cardiac function. They also had thicker septal walls and increased chamber diameter, hallmarks of physiological hypertrophy. Heart weight to body weight ratio was significantly higher after exercise. When isolated hearts were administered ischemia/reperfusion injury, the exercised hearts showed a significant improvement in recovery compared to sedentary LTCC overexpressed hearts. Calcium activity was enhanced at the cardiomyocyte level in both mouse lines of exercised mice. In conclusion, hearts with a pathological hypertrophic phenotype can enhance function and achieve cardioprotection through chronic exercise. / Physiology
46

Étude d'une nouvelle population de lymphocytes T « innate-memory » : implication dans l'immunité anti-leucémique au cours de la leucémie myéloïde chronique / Evidence for innate-memory T cells in human : implication in antitumor response during chronic myeloid leukemia

Jacomet, Florence 18 December 2015 (has links)
La leucémie myéloïde chronique (LMC) est une hémopathie maligne caractérisée par un syndrome myéloprolifératif. Elle est secondaire à la formation d’un gène chimérique BCR-ABL dont le produit de ce gène de fusion est une protéine possédant une activité tyrosine kinase dérégulée, nécessaire et suffisante à la leucémogénèse. Plusieurs arguments suggèrent l’implication des cellules du système immunitaire dans le contrôle de la LMC.Nous avons montré que les lymphocytes Natural Killer T invariant (iNKT), une population minoritaire de lymphocytes T non conventionnels impliqués dans l’immunosurveillance, sont anergiques chez les patients en phase chronique (LMC-PC). Ce défaut est corrigé chez les patients en rémission cytogénétique complète après traitement par Imatinib Mesylate (LMC-IM) ou IFN-α.Les lymphocytes iNKT sont impliqués chez la Souris dans la génération de cellules T CD8+ « innate-memory », une autre population de lymphocytes T innés découverte récemment chez la Souris. Nous avons mis en évidence chez l’Homme, l’existence d’une population de cellules T ayant un phénotype inné et mémoire, exprimant fortement le facteur de transcription Eomesodermine et capable de produire rapidement de l’IFN-γ en réponse à une stimulation innée par les interleukines (IL)-12 et IL-18.Cette population de cellules est déficiente sur le plan numérique et fonctionnel chez les patients LMC-PC. Ces défauts sont partiellement corrigés chez les patients LMC-IM.L’ensemble de ces résultats souligne le rôle des lymphocytes T innés dans l’immunité anti-leucémique et pourrait permettre le développement de stratégies d’immunothérapies ciblées contre la LMC. / Chronic myeloid leukemia (CML) is a myeloproliferative disorder that results from dysregulated tyrosine kinase activity of the fusion oncoprotein BCR-ABL, which is sufficient to induce malignant transformation. A critical role of the immune system in the control of CML is supported by several reports. Invariant Natural Killer T (iNKT) lymphocytes are a population of non-conventional T cells that are believed to play a key role in cancer immunosurveillance. Here, we showed that CML in chronic phase is associated with anergy of iNKT cells that is restored upon complete cytogenetic remission (CCyR) following Imatinib Mesylate (IM) or IFN-α therapy. In mouse, iNKT cells are involved in the generation of a recently characterized subset of innate CD8 T cells. Importantly, we provided definitive evidence of the existence of an equivalent of these innate CD8 T cells in humans, harboring innate and memory phenotype with high Eomesodermin expression. These cells also exhibited innate functions such as prompt IFN-γ expression in response to innate stimulation by interleukin (IL)-12 and IL-18 and cytolytic activity in a TCR independent manner.Size and functions of this innate-like CD8 T cell subset were severely impaired in CML patients at chronic phase. These defects were partially reversed in patients who achieved CCyR following IM treatment.Altogether, these results reveal a possible contribution of innate CD8 T lymphocytes in anti-leukemic immunity and should contribute to development of immunotherapeutic strategies against CML.
47

Traitement anticancéreux et modulation du système immunitaire / Effects of Anticancer Agents on Immune Responses

Zoubir, Mustapha 06 April 2012 (has links)
Les thérapies anticancéreuses ont apporté un gain largement reconnu en matière de réduction de la charge tumorale, de survie des patients et d’amélioration de leur qualité de vie, dans un certain nombre de cancers. Hélas, ces thérapies exercent un effet immunosuppresseur en détruisant les effecteurs ou en bloquant l’activité de certains facteurs biologiques impliqués dans le recrutement des acteurs du système immunitaire. D’autre part, plusieurs travaux ont permis de démontrer que ces traitements pouvaient avoir un effet contraire en générant ou en favorisant l’induction d’une réponse immunitaire anti-tumorale, soit par effet direct sur le recrutement et l’activation des effecteurs de l’immunité, soit en potentialisant les interactions cellulaires par des mécanismes biologiques. Ces derniers faisant intervenir les cytokines, la stimulation des TLR, l’augmentation des interactions entre cellules du SI; ce qui permet de passer d’une anergie immunologique vers un véritable système d’éradication des cellules cancéreuses.Dans notre laboratoire, nous avons essayé d’évaluer l’implication du système immunitaire dans la réponse thérapeutique induite par des agents cytotoxiques conventionnels. Ici, nous décrivons les effets d’un inhibiteur de cyclines kinases multi-cibles « CDKi PHA-793 887 » testé dans un essai de phase I mené sur deux sites en Europe. C’est le constat inattendu que 6 des 15 patients, traités par ce médicament (PHA-793887) ont développé de graves infections bactériennes et virales et que 6 d’entre eux ont présenté la réactivation du virus de l’herpès qui nous a conduit à étudier ces effets sur le système immunitaire et en particulier sur le dialogue entre cellules dendritiques (CD) et cellules natural killer (NK). Ce travail met en évidence que ce médicament inhibe le signalling des récepteurs toll-like (TLR) réduisant par conséquent l’interaction CD/NK in vitro. Enfin la stimulation des cellules des patients sous traitement démontre une réduction importante de ce signalling ex-vivo. Ainsi, cet effet immunosuppresseur inattendu a permis une réactivation virale chez 40% des patients. La deuxième partie de ce travail, concerne les effets du cyclophosphamide (CTX) utilisé à faible dose. L’injection d'une faible dose chez la souris ou d’un dosage métronomique chez l'homme, promeut la différenciation des cellules lymphocytaires vers Th17 (sécrétant de l’interleukine-17 (IL-17)) et Th1 (sécrétant de l’interféron-γ (IFN)). Ceux-ci ont été retrouvés dans le sang et dans des ascites carcinomateuses de patients. Ainsi, le CTX pourrait participer à la génération de réponses anti-tumorale via la différenciation Th 17 comme cela fut suggéré par de récentes études précliniques montrant l’existence d’une corrélation étroite entre le taux des lymphocytes Th17 infiltrant la tumeur et la destruction tumorale. / Cancer therapies have made a gain widespread recognition in the reduction of tumor burden, patient survival and improved quality of life in a number of cancers. Unfortunately, these therapies exert an immunosuppressive effect by killing effectors or blocking the activity of certain biological factors involved in recruiting of the immune system. On the other hand, several studies have shown that these treatments could have the opposite effect by generating or promoting the induction of antitumor immune response, either by direct effect on the recruitment and activation of effectors immunity, either by potentiating cellular interactions by biological mechanisms. The latter involving cytokines, TLR stimulation, increased interactions between cells of the IS; which toggles between immunological anergy to a real system to eradicate cancer cells. In our laboratory, we tried to evaluate the involvement of the immune system in the therapeutic response induced by conventional cytotoxic agents. Here, we describe the effects of an inhibitor of cyclin kinases multi-target "CDKIs PHA-793887" tested in a phase I trial conducted at two sites in Europe. This unexpected finding is that 6 of 15 patients treated with this drug (PHA-793887) developed severe bacterial and viral infections and six of them showed reactivation of the herpes virus that has led us to study these effects on the immune system and in particular on the dialogue between dendritic (DCs) and natural killer (NK) cells. This work shows that this drug inhibits the signaling of toll-like receptor (TLR) thereby reducing the interaction DC / NK in vitro. Finally, stimulation of the cells of treated patients demonstrated a significant reduction of this signaling ex vivo. Thus, this immunosuppressive effect has an unexpected viral reactivation in 40% of patients. The second part of this work concerns the effects of metronomic dose of cyclophosphamide (CTX). The injection of a low dose in mice or metronomic dosing in humans, markedly promotes the differentiation of CD4+ T helper 17 (Th17) cells that can be recovered in both blood and tumor beds. However, CTX does not convert regulatory T cells into Th17 cells and promotes cell differentiation into Th17 lymphocytes (secreting interleukin-17 (IL-17)) and Th1 (secreting interferon-γ (IFN)). These were found in blood and in ascites carcinoma patients. Thus, CTX may participate in the generation of antitumor responses through Th 17 differentiation as was suggested by recent preclinical studies showing the existence of a correlation between the rate of Th17 lymphocytes infiltrating the tumor and tumor destruction.
48

Monitoramento terapêutico de mesilato de imatinibe: relação entre níveis séricos e alcance de resposta molecular maior na leucemia mielóide crônica / Therapeutic drug monitoring of imatinib mesylate: relationship between serum levels and the molecular outcome (as determined by major molecular response) in chronic myeloid leukemia

Rezende, Vinicius Marcondes 26 March 2018 (has links)
Dentre os vários tipos de leucemia, destaca-se a Leucemia Mielóide Crônica (LMC), um distúrbio mieloproliferativo em que ocorre a translocação entre o gene BCR no cromossomo 22 e o gene ABL1 no cromossomo 9. Essa translocação cria um cromossomo conhecido como Philadelphia (t 9,22)(q34;q11), ou Ph+, e a consequente formação de um produto único de proteínas BCR-ABL1. Essa proteína tem atividade de quinase constitutiva e impulsiona a proliferação descontrolada de células tronco hematopoiéticas. O surgimento de uma nova classe farmacológica no início dos anos 2000 - os inibidores de tirosina quinases, revolucionou o tratamento e o prognóstico da LMC, permitindo que esse câncer fosse tratado praticamente como uma doença crônica, com farmacoterapia oral. A droga de estréia dessa classe, o Mesilato de Imatinib, foi desenvolvida através de modelagem molecular para ser alvo-específica, mas apesar do desenvolvimento exitoso, após o início da comercialização, foram observadas falhas na ação em determinados pacientes. Há evidências de que a avaliação da relação entre a dose de imatinibe (e seus níveis sanguíneos) e a eficácia do tratamento medida através das respostas Hematológica, Citogenética e Molecular, seja uma forma de realizar o ajuste da dose reduzindo efeitos colaterais e custo do tratamento. No presente estudo foram avaliadas as concentrações séricas de imatinib, Cmin e Cmax, em 51 pacientes com Leucemia Mielóide Crônica, dos quais 33 atingiram Resposta Molecular Maior em até 12 meses de tratamento, 11 levaram mais que 12 meses para antingir, e 7 não atingiram. As concentrações séricas obtidas desses pacientes indicaram que no grupo que atingiu RMM em até 12 meses, os valores de vale (Cmin) se apresentaram com mediana de 889.2 ng/mL (721.9 e 1202.4 para primeiro e terceiro quartis respectivamente), sendo que o grupo que levou mais de 12 meses para atingir RMM, a concentração mediana observada foi de 611.0 ng/mL (493.0 e 816.0 para primeiro e terceiro quartis respectivamente), sendo essa diferença estatisticamente significativa (p < 0.05). Dessa forma demonstrou-se a importância do monitoramento das concentrações séricas de imatinib para o ajuste da dose e para a gestão do tratamento na mudança para segunda geração de inibidores de tirosina quinase. Através da análise comparativa dos dados populacionais estudados, observou-se não haver correlação significativa entre as concentrações séricas e índice de massa corpórea (IMC), peso, idade ou sexo / Among the various types of leukemia, Chronic Myeloid Leukemia (CML) stands out as a myeloproliferative disorder in which translocation occurs between the BCR gene on chromosome 22 and the ABL1 gene on chromosome 9. This translocation creates a chromosome known as Philadelphia (t 9,22) (q34; q11), or Ph +, and the consequent formation of a unique BCR-ABL1 protein product. This protein has constitutive kinase activity and drives the uncontrolled proliferation of hematopoietic stem cells. The launch of a new pharmacological class in the early 2000s - the tyrosine kinases inhibitors, revolutionized the treatment and prognosis of CML, allowing that cancer to be treated virtually as a chronic disease with oral pharmacotherapy. The newbie drug of this class, Imatinib Mesylate, was developed through molecular modeling to be target-specific, but despite the successful development, after the beginning of marketing, certain patients presented some failures in the response. There is an evidence that an assessment of the relationship between a dose of Imatinib (and its blood levels) and the efficacy of treatment from its Hematologic, Cytogenetic and Molecular Responses, is a really effective way to perform dose adjustment reducing side effects and cost of treatment. In the present study, the serum concentrations of Imatinib, Cmin and Cmax were evaluated in 51 patients with chronic myeloid leukemia, of which 33 reached major molecular response in up to 12 months of treatment, 10 took more than 12 months to achieve it, and 7 did not reach that. The serum concentrations obtained from those patients indicated that in the group that reached Major Molecular Response (MMR) within 12 months, the trough level (Cmin) presented a median of 889.2 ng / mL (721.9 and 1202.4 for first and third quartiles, respectively), and the group which took more than 12 months to reach MMR, the median concentration observed was 611.0 ng / mL (493.0 and 816.0 for the first and third quartiles respectively), and this difference was statistically significant (p < 0.05). Thus, the importance of monitoring serum imatinib concentrations for dose adjustment and treatment management in switching to second-generation tyrosine kinase inhibitors has been demonstrated. Through the comparative analysis of the population data, there was no significant correlation between serum concentrations and body mass index (BMI), weight, age or gender
49

Monitoramento terapêutico de mesilato de imatinibe: relação entre níveis séricos e alcance de resposta molecular maior na leucemia mielóide crônica / Therapeutic drug monitoring of imatinib mesylate: relationship between serum levels and the molecular outcome (as determined by major molecular response) in chronic myeloid leukemia

Vinicius Marcondes Rezende 26 March 2018 (has links)
Dentre os vários tipos de leucemia, destaca-se a Leucemia Mielóide Crônica (LMC), um distúrbio mieloproliferativo em que ocorre a translocação entre o gene BCR no cromossomo 22 e o gene ABL1 no cromossomo 9. Essa translocação cria um cromossomo conhecido como Philadelphia (t 9,22)(q34;q11), ou Ph+, e a consequente formação de um produto único de proteínas BCR-ABL1. Essa proteína tem atividade de quinase constitutiva e impulsiona a proliferação descontrolada de células tronco hematopoiéticas. O surgimento de uma nova classe farmacológica no início dos anos 2000 - os inibidores de tirosina quinases, revolucionou o tratamento e o prognóstico da LMC, permitindo que esse câncer fosse tratado praticamente como uma doença crônica, com farmacoterapia oral. A droga de estréia dessa classe, o Mesilato de Imatinib, foi desenvolvida através de modelagem molecular para ser alvo-específica, mas apesar do desenvolvimento exitoso, após o início da comercialização, foram observadas falhas na ação em determinados pacientes. Há evidências de que a avaliação da relação entre a dose de imatinibe (e seus níveis sanguíneos) e a eficácia do tratamento medida através das respostas Hematológica, Citogenética e Molecular, seja uma forma de realizar o ajuste da dose reduzindo efeitos colaterais e custo do tratamento. No presente estudo foram avaliadas as concentrações séricas de imatinib, Cmin e Cmax, em 51 pacientes com Leucemia Mielóide Crônica, dos quais 33 atingiram Resposta Molecular Maior em até 12 meses de tratamento, 11 levaram mais que 12 meses para antingir, e 7 não atingiram. As concentrações séricas obtidas desses pacientes indicaram que no grupo que atingiu RMM em até 12 meses, os valores de vale (Cmin) se apresentaram com mediana de 889.2 ng/mL (721.9 e 1202.4 para primeiro e terceiro quartis respectivamente), sendo que o grupo que levou mais de 12 meses para atingir RMM, a concentração mediana observada foi de 611.0 ng/mL (493.0 e 816.0 para primeiro e terceiro quartis respectivamente), sendo essa diferença estatisticamente significativa (p < 0.05). Dessa forma demonstrou-se a importância do monitoramento das concentrações séricas de imatinib para o ajuste da dose e para a gestão do tratamento na mudança para segunda geração de inibidores de tirosina quinase. Através da análise comparativa dos dados populacionais estudados, observou-se não haver correlação significativa entre as concentrações séricas e índice de massa corpórea (IMC), peso, idade ou sexo / Among the various types of leukemia, Chronic Myeloid Leukemia (CML) stands out as a myeloproliferative disorder in which translocation occurs between the BCR gene on chromosome 22 and the ABL1 gene on chromosome 9. This translocation creates a chromosome known as Philadelphia (t 9,22) (q34; q11), or Ph +, and the consequent formation of a unique BCR-ABL1 protein product. This protein has constitutive kinase activity and drives the uncontrolled proliferation of hematopoietic stem cells. The launch of a new pharmacological class in the early 2000s - the tyrosine kinases inhibitors, revolutionized the treatment and prognosis of CML, allowing that cancer to be treated virtually as a chronic disease with oral pharmacotherapy. The newbie drug of this class, Imatinib Mesylate, was developed through molecular modeling to be target-specific, but despite the successful development, after the beginning of marketing, certain patients presented some failures in the response. There is an evidence that an assessment of the relationship between a dose of Imatinib (and its blood levels) and the efficacy of treatment from its Hematologic, Cytogenetic and Molecular Responses, is a really effective way to perform dose adjustment reducing side effects and cost of treatment. In the present study, the serum concentrations of Imatinib, Cmin and Cmax were evaluated in 51 patients with chronic myeloid leukemia, of which 33 reached major molecular response in up to 12 months of treatment, 10 took more than 12 months to achieve it, and 7 did not reach that. The serum concentrations obtained from those patients indicated that in the group that reached Major Molecular Response (MMR) within 12 months, the trough level (Cmin) presented a median of 889.2 ng / mL (721.9 and 1202.4 for first and third quartiles, respectively), and the group which took more than 12 months to reach MMR, the median concentration observed was 611.0 ng / mL (493.0 and 816.0 for the first and third quartiles respectively), and this difference was statistically significant (p < 0.05). Thus, the importance of monitoring serum imatinib concentrations for dose adjustment and treatment management in switching to second-generation tyrosine kinase inhibitors has been demonstrated. Through the comparative analysis of the population data, there was no significant correlation between serum concentrations and body mass index (BMI), weight, age or gender
50

Avaliação do perfil in vitro de dissolução de comprimidos de mesilato de imatinibe empregando a cromatografia líquida de alta eficiência / Evaluation of the in vitro dissolution profile of imatinib mesylate tablets using the high performance liquid chromatography

Hanna, Thiago Branco 25 October 2010 (has links)
A leucemia mielóide crônica (LMC) é uma doença cujo marcador molecular é o rearranjo gênico BCR/ABL, original da translocação t(9;22), conhecida como cromossomo Philadelphia. Recentemente, os inibidores da enzima tirosina-quinase têm sido estudados e utilizados para o tratamento da LMC. Nesta classe, está o Mesilato de Imatinibe, uma pequena molécula que inibe competitivamente a BCR/ABL tirosina quinase, impedindo sua atividade. Por não possuir monografia publicada em compêndios oficiais, o objetivo deste trabalho foi avaliar o perfil in vitro de dissolução de comprimidos de mesilato em diferentes condições. A quantificação do fármaco foi feita utilizando a cromatografia líquida de alta eficiência em fase reversa (CLAE-FR) e as análises foram realizadas em uma coluna C18 Gemini Phenomenex®, utilizando como fase móvel tampão acetato de sódio 10,7 mmol/L, pH 3,0:metanol (40:60 v/v). O método foi validado e apresentou-se linear no intervalo de concentração de 10-150 µg/mL (r=0,9993). Os coeficientes de variação obtidos foram inferiores a 2,0 % e a exatidão próxima de 100 %. Também foram avaliados os parâmetros seletividade, robustez, estabilidade e limite de quantificação (10 µg/mL). A avaliação do perfil in vitro de dissolução foi realizada em três diferentes meios de dissolução (HCl 0,1 N, tampão acetato de sódio pH 4,5 e tampão fosfato de potássio monobásico pH 6,8), três velocidades de agitação (50, 75 e 100 rpm) e dois tipos de aparatos (pá e cesta). Os resultados obtidos neste teste indicaram que a forma farmacêutica em estudo é de liberação imediata, uma vez que foi verificada liberação de grande quantidade do fármaco em um curto período de tempo. A comparação dos perfis de dissolução, realizada através do cálculo da eficiência de dissolução, apresentou diferenças em relação à porcentagem do fármaco liberado. a condição mais adequada para avaliar o perfil in vitro de dissolução é o meio de dissolução HCl 0,1 N, aparato da pá e velocidade de agitação de 75 ou 100 rpm. / Chronic myeloid leukemia (CML) is a disease whose molecular marker is the BCR/ABL, original of the translocation t (9; 22), known as the Philadelphia chromosome. Recently, inhibitors of the enzyme tyrosine kinase have been studied and used for the treatment of CML. In this class, is the Imatinib mesylate, a small molecule that competitively inhibits BCR/ABL tyrosine kinase, preventing its activity. To do not have a monograph published in official compendia, the objective of this study was to evaluate the in vitro dissolution of tablets mesylate in different conditions. The quantification of the drug was made using high performance liquid chromatography on reversed phase (RP-HPLC) and analysis was performed on a Phenomenex® Gemini C18 column using a mobile phase of sodium acetate buffer 10.7 mmol/L pH 3.0:methanol (40:60 v/v). The method was validated and presented in a linear concentration range of 10-150 µg/mL (r=0.9993). The coefficients of variation obtained were below 2.0% and accuracy near 100%. We also evaluated the parameters selectivity, robustness, stability and limit of quantification (10 µg/mL). The evaluation of in vitro dissolution was conducted in three different dissolution media (0.1 N HCl, sodium acetate buffer pH 4.5 and potassium phosphate monobasic buffer pH 6.8), three agitation speeds (50, 75 and 100 rpm) and two types of devices (paddle and basket). The results of this tests indicated that the pharmaceutical form in question is immediate release, since it was observed release of large amounts of the drug in a short period of time. The comparison of dissolution profiles, conducted by calculating the dissolution efficiency, showed differences compared to the percentage of drug released. The best conditions to evaluate the in vitro profile of dissolution is the dissolution medium 0.1 N HCl, paddle apparatus and stirring speed of 75 or 100 rpm.

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