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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.
21

Fatores de risco para mucosite bucal em pacientes com leucemia linfóide aguda submetidos a diferentes protocolos de tratamento / Risk factors to oral mucositis in patients with acute limphoblastic leukemia submitted to different treatment protocols

Suzana Luzia Coelho Figliolia 30 November 2006 (has links)
A mucosite bucal está entre as principais complicações decorrentes do tratamento antineoplásico em pacientes com leucemia linfóide aguda (LLA). Entre os fatores de risco para sua ocorrência destacam-se a idade, o gênero e a leucometria inicial, além das drogas quimioterápicas com comprovada ação estomatotóxicas. O objetivo deste estudo foi investigar a prevalência e os fatores de risco para a mucosite bucal em pacientes com LLA submetidos a diferentes protocolos de tratamento quimioterápicos. Um total de 169 prontuários clínicos de pacientes oncológicos pediátricos submetidos a diferentes protocolos de tratamento para LLA no Setor de Oncologia Pediátrica do Hospital Infantil Darcy Vargas, na cidade de São Paulo, no período compreendido entre 1994 a 2005 foram, retrospectivamente, avaliados. Os dados demográficos (idade e gênero) e clínicos (leucometria inicial, protocolo de tratamento a que foi submetido, evolução, ocorrência de mucosite e outras lesões bucais) foram registrados. A associação da mucosite bucal com as variáveis clínicas e demográficas foi obtida pelos testes do qui-quadrado e análise de regressão logística multivariada. Os resultados demonstraram uma freqüência de mucosite bucal em 46% dos pacientes oncológicos pediátricos com LLA sem correlação estatisticamente significativa entre sua ocorrência e o gênero (p=0,08), a idade (p=0,33) e a leucometria inicial (p=0,34). Na análise multivariada o protocolo de tratamento do grupo Berlim- Frankfurt-Munique de 1995 (ALL-BFM 95), de acordo com as variáveis avaliadas neste estudo, mostrou ser o fator mais significativo (p=0,009) para a ocorrência da mucosite bucal. Esses resultados fortemente sugerem uma maior estomatotoxicidade do protocolo ALL-BFM 95 comprovadas pela maior freqüência de mucosite bucal nos pacientes ontológicos pediátricos com LLA. Portanto, concluímos que a mucosite bucal deveria ser sistematicamente analisada nos centros especializados no tratamento da LLA que adotam diferentes protocolos de tratamento, visando não somente contribuir com a análise do grau de toxicidade das drogas quimioterápicas, mas principalmente, melhorar a qualidade de vida do paciente com base em condutas terapêuticas e profiláticas mais efetivas na prevenção de sua ocorrência. / Oral mucositis is one of the main complications secondary to antineoplastic treatment in patients with acute lymphoblastic leukemia (ALL). The risk factors for its occurrence include age, gender and initial leukocyte count, besides chemotherapeutic drugs with known stomatotoxic action. This study investigated the prevalence and risk factors to oral mucositis in patients with ALL submitted to different chemotherapeutic treatment protocols. A total of 169 clinical records of pediatric oncology patients submitted to different treatment protocols for ALL at the Pediatric Oncology Sector of the Child Hospital Darcy Vargas, in the city of São Paulo, in the period 1994 to 2005 were retrospectively evaluated. Demographic (age and gender) and clinical data (initial leukocyte count, treatment protocol adopted, evolution, occurrence of mucositis and other oral lesions) were recorded. The association of oral mucositis with the clinical and demographic variables was assessed by the chi-square test and multivariate logistic regression analysis. The results demonstrated occurrence of oral mucositis in 46% of pediatric oncology patients with ALL, without statistically significant correlation between its occurrence and gender (p=0.08), age (p=0.33) and initial leukocyte count (p=0.34). Multivariate analysis revealed that the Berlin-Frankfurt-Munich protocol of 1995 (ALL-BFM 95) was the most significant factor (p=0.009) to the occurrence of oral mucositis according to the variables evaluated in this study. These results strongly suggest the greater stomatotoxic effect of the ALL-BFM 95 protocol, as demonstrated by the higher frequency of oral mucositis in pediatric oncology patients with ALL. Thus, it may be concluded that oral mucositis should be systematically analyzed in centers specialized in the treatment of ALL adopting different treatment protocols, with a view to contribute to analysis of the degree of toxicity of chemotherapeutic drugs and mainly to improve the quality of life of patients on the basis of more effective therapeutic and prophylactic approaches for prevention of its occurrence.
22

Produção de L-asparaginase (ASP3) de Saccharomyces cerevisiae expressa em Pichia  pastoris / Production of L-Asparaginase (ASP3) from Saccharomyces cerevisiae expressed in Pichia pastoris

Omar Santiago Pillaca Pullo 20 September 2016 (has links)
A enzima L-asparaginase (ASNase) usada como biofármaco no tratamento de Leucemia Linfoblástica Aguda (LLA) é de origem bacteriana, o que provoca reações imunológicas nos paciente e a ASNase usada no Brasil é importada o que dificulta seu uso por razões de abastecimento e de preço. Por outra parte, dentro dos sistemas de expressão de proteínas recombinantes usados pela biotecnologia, destaca-se a Pichia pastoris, levedura metilotrófica de fácil manipulação, crescimento rápido, alta capacidade de expressão e capaz de realizar modificações pós-traducionais. Neste projeto, o gene de ASNase II de Saccharomyces cerevisiae foi expressa em P. pastoris (Muts), tendo sido analisada a localização da enzima nos meios extracelular, intracelular e espaço periplasmático. Além disso, foram avaliadas diversas condições de crescimento e indução da ASNase em agitador orbital e finalmente foi feito o cultivo em biorreator de 3L operado em batelada. Segundo o analise da expressão, a enzima foi localizada no espaço periplasmático. O crescimento de P. pastoris em diferentes concentrações de glicerol (10,0 - 50,0 g.L-1) mostraram parâmetros cinéticos similares (µmáx = 0,35 h-1; tg= 2,0 h) e o maior fator de conversão de substrato em células (Y x/s = 0,9 g g-1) foi obtido com 10,0 g.L-1 de glicerol. A expressão de ASNase somente ocorreu a 20 °C e melhora com concentrações de metanol acima de 1,0% (v/v), obtendo-se a maior produção da enzima a 3% de metanol durante 48 horas, o que foi corroborado pelo planejamento fatorial fraccionado (3n-k + 2), n = 3 e k =1. Também se observou que o pH de indução, a suplementação com aminoácidos ou casaminoácidos e concentração de glicerol durante a fase de crescimento apresentaram pouca ou nenhuma influência na expressão. Entretanto, as células induzidas imediatamente após o glicerol ter sido consumido melhoraram a produção de ASNase. No cultivo em biorreator, a fase de crescimento foi feita com 10,0 e 40,0 g.L-1-1 de glicerol, e a fase de indução com pulsos de 3,0% (v/v) de metanol durante 120 horas. A maior atividade volumétrica (710,2 U.L-1) de ASNase foi obtida na batelada com 40,0 g.L-1 de glicerol e a atividade periplasmática foi constante durante o tempo de cultivo o que significa que o controle do pH afeta positivamente na expressão de ASNase. / The bacterial L-asparaginase (ASNase) is used as biopharmaceutical in the treatment of acute lymphoblastic leukemia (ALL) and non-Hodgkin lymphoma and because his origin causes immune reactions in patients. The ASNase used in Brazil is imported which hinders its use due to supply availability and price. The methylotrophic yeast Pichia pastoris, is a microrganism easy to handle and with fast growth and high capacity of expression of recombinant proteins and that is able to carry out post-translational modifications. In this work, Saccharomyces cerevisiae ASNase II gene was expressed in Pichia pastoris (Muts) and was analyzed its localization in extra and intracellular medium and periplasmic space. Also, different conditions of growth and induction were evaluated in shaker, that culminated in a cultivation carried out in 3L bioreactor operated in batch. According the expression analysis, the enzyme was localized in periplasmic space; Pichia pastoris growth in different concentrations of glycerol (10 - 50 g.L-1) show similar kinetic parameters (µmáx = 0.35 h-1; tg = 2.0 h), with the higher substrate to biomass yield (Y x/s= 0.9 g.g-1) obtained with 10 g.L-1 of glycerol. The ASNase expression only occurred at 20°C and improves with methanol concentrations above 1.0% (v/v) to yield the highest production ASNase 3.0% methanol for 48 hours, which was corroborated by factorial fractionated design (3n-k + 2), n = 3 and k = 1. Also was observed that the pH of induction, supplementation with amino acids or casaminoacids and glycerol concentration during the growth phase had little or null influence on the expression. However the induction immediately after glycerol depletion improved the ASNase production. In bioreactor, were used 10 and 40 g.L-1 of glycerol in the growth phase and in the induction phase were used methanol pulses of 3.0% (v/v) during 120 hours. The major volumetric activity (710,2 U.L-1) of ASNase occurred in batch cultivation with 40 g.L-1 of glycerol and periplasmic activity was almost constant during the process which means that the control of pH affects positively the ASNase expression.
23

Produção, caracterização cinética e engenharia de proteína Asparaginase 1 de Saccharomyces cerevisiae para avaliação de seu uso como biofármaco / Production, kinetic characterization and engineering of asparaginase 1 protein from Saccharomyces cerevisiae to evaluate its use as a biopharmaceutical.

Iris Munhoz Costa 23 October 2015 (has links)
A L-asparaginase (EC 3.5.1.1) é uma enzima importante para o tratamento da leucemia linfoblástica aguda (LLA), neoplasia mais frequente em crianças e adolescentes. A L-asparaginase hidrolisa a L-asparagina resultando em ácido aspártico e amônio, impedindo que as células tumorais utilizem esse aminoácido para síntese proteica, ocasionando a morte celular apoptótica. Atualmente a enzima é obtida a partir de Escherichia coli e Erwinia chrysanthemi; no entanto, ambas as formulações estão associadas a um alto índice de efeitos adversos que comprometem a evolução e eficácia do tratamento. A levedura Saccharomyces cerevisiae tem o gene ASP1 responsável pela produção de L-asparaginase 1 (Sc_ASPase1) que tem sido pouco estudada. Para elucidar as características de Sc_ASPase1 nós expressamos a proteína em E. coli BL21(DE3) e a purificamos por cromatografia de afinidade. Sc_ASPase1 tem uma atividade especifica de 195,4 U/mg para L-asparagina e de 0,36 U/mg para L-glutamina, e um comportamento alostérico com um K0.5 de 75 µM para L-asparagina. Por meio de mutação sitio dirigida demonstramos a importância dos resíduos Thr64-Thy78-Th141-Lys215 para a catálise. As isoformas mutantes da proteína A331D, K335E, Y243S, S301N e ΔG77 não apresentaram melhoria nos parâmetros cinéticos ou atividade específica. Construímos e clonamos Sc_ASPase1 com a deleção dos primeiros 52 aminoácidos, porém nas condições testadas a proteína foi expressa na forma insolúvel. Demonstramos que Sc_ASPase1 possui potencial antineoplásico, pois com 10 U/mL de enzima foi capaz causar a 85% de mortalidade da linhagem leucêmica MOLT-4. Na mesma concentração, a enzima de E. coli é capaz de matar 95% de células dessa mesma linhagem. / L-Asparaginase (EC 3.5.1.1) is an important enzyme for the treatment of acute lymphoblastic leukemia (ALL), the most common malignancy in children and adolescents. L-asparaginase hydrolyzes L-asparagine resulting in ammonium and aspartic acid, preventing tumor cells of using such amino acid for protein synthesis, leading to apoptotic cell death. Currently, the enzyme is obtained from Escherichia coli and Erwinia chrysanthemi; however, both formulations are associated with a high incidence of side effects that compromise the progress and effectiveness of treatment. The yeast Saccharomyces cerevisiae has ASP1 gene responsible for the production of L-asparaginase 1 (Sc_ASPase1) that has been poor studied. To elucidate the characteristics of Sc_ASPase1, we expressed the protein in E. coli BL21 (DE3) cells and purified it by affinity chromatography. Sc_ASPase1 has a specific activity of 195.4 U/mg for L-asparagine and 0.36 U/mg for L-glutamine, and an allosteric behavior with a K0.5 of 75 µM for L-asparagine. Through site directed mutation, we demonstrated the importance of Thr64-Thy78-Th141-Lys215 residues for catalysis. The mutant protein isoforms A331D, K335E, Y243S, S301N and ΔG77 showed no improvement in kinetic parameters or specific activity. We build and cloned Sc_ASPase1 with the deletion of the first 52 amino acids, but under the conditions tested the protein was expressed in insoluble form. Sc_ASPase1 have demonstrated potential antineoplastic activityc, since 10 U/mL of enzyme lead to 85% of mortality in leukemia cell line MOLT-4. At the same concentration, the E. coli enzyme kills 95% of the cells of the same line.
24

EXPRESSÃO DOS MARCADORES CD56, CD16 E CD57 NA AVALIAÇÃO PROGNÓSTICA DE PACIENTES COM LEUCEMIA LINFÓIDE AGUDA NO ESTADO DO MARANHÃO / EXPRESSION OF MARKERS CD56, CD16 AND CD57 NA PROGNOSTIC EVALUATION OF PATIENTS WITH ACUTE LYMPHOBLASTIC LEUKEMIA IN MARANHÃO

Andrade, Karla Nadinne de Sousa 28 September 2012 (has links)
Made available in DSpace on 2016-08-19T18:16:06Z (GMT). No. of bitstreams: 1 DISSERTACAO KARLA.pdf: 550872 bytes, checksum: a1efbaeab3d76483b6e7b53d97cc5a68 (MD5) Previous issue date: 2012-09-28 / The acute lymphoblastic leukemia (ALL) is characterized by abnormal proliferation of immature lymphoid cells and represents the most common cancer in children. The evaluation of prognostic factors in patients with ALL enables the implantation of different therapeutic approaches. The aberrant expression of markers CD56, CD57 and CD16 may be a way to assess this prognosis. The objective of this study was to characterize patients with ALL and to evaluate the prognostic influence of aberrant expression of markers CD56, CD16 and CD57 in ALL. 44 patients treated at the Maranhense Oncology Institute Aldenora Bello in Sao Luis - MA were evaluated, from March 2010 to October 2011. Patients were diagnosed with ALL according to the morpho-cytochemical and immunophenotype criteria. The expression of markers was determined by flow cytometry and clinical data were obtained through chart review. Two groups were divided as the expression or not of these markers and compared in relation to prognostic variables. The average of age in the sample was 6,28 years, with a predominance of males (60,0%). The average of blasts counted in bone marrow (BM) and peripheral blood (PB) was 77,0 and 39,6, respectively. The L1 morphology of the blasts from BM was the most frequent (80,0%). The profile of the blood count at diagnosis indicated: 24.061 leukocytes/mm3; 56.510 platelets/mm3 and 8,0 g/dL hemoglobin. According to the classification GBTLI-99, 60,0% of the patients were in low risk of recurrence group and in the end of the induction phase of treatment (D29), 70,0% of the patients had remission. The patients with ALL T had mean of age (10,6 years; p = 0,0204) and leukometry (48.200/mm3; p = 0,0167) significantly higher than patients with ALL B. 80,0% of the patients expressed the CD56 marker and no patient expressed CD16 and/or CD57 markers. Patients who did not express the marker CD56 had age significantly higher those who expressed (9,3 years; p = 0,0353). For patients with ALL B, the average of blasts from PB of patients who expressed the CD56 marker was higher than those not expressed (41,1; p = 0,0226). It is concluded that CD56 expression characterizes a worse prognosis for patients with ALL B, due to a significantly higher average of blasts counted in PB found in our study. However, a greater number of cases and a longer observation time would be needed to better emphasize this evidence. / A Leucemia linfóide aguda (LLA) é caracterizada pela proliferação anormal de células linfóides imaturas e representa a neoplasia mais comum em crianças. A avaliação de fatores prognósticos em pacientes com LLA possibilita a implantação de abordagens terapêuticas diferenciadas. A expressão aberrante dos marcadores CD56, CD57 e CD16 pode ser uma forma de avaliar tal prognóstico. O objetivo deste trabalho foi caracterizar os pacientes com LLA e avaliar a influência prognóstica da expressão aberrante dos marcadores CD56, CD16 e CD57 na LLA. Foram avaliados 40 pacientes, atendidos no Instituto Maranhense de Oncologia Aldenora Bello (IMOAB), em São Luís MA, no período de março de 2010 a outubro de 2011. Os pacientes foram diagnosticados com LLA, segundo os critérios morfo-citoquímicos e imunofenotípicos. A expressão dos marcadores foi determinada através da citometria de fluxo e os dados clínicos foram obtidos através da revisão de prontuários. Dois grupos foram divididos quanto à expressão ou não dos referidos marcadores e comparados em relação às variáveis prognósticas. A média de idade na amostra foi de 6,28 anos, sendo o sexo masculino predominante (60,0%). A média de blastos contados na medula óssea (MO) e sangue periférico (SP) foram de 77,0 e 39,6, respectivamente. A morfologia L1 dos blastos da MO foi a mais frequente (80,0%). O perfil do hemograma, ao diagnóstico, indicou: 24.061 leucócitos/mm3, 56.510 plaquetas/mm3 e 8,0 g/dL de hemoglobina. De acordo com a classificação GBTLI-99, 60,0% dos pacientes se encontravam no grupo de baixo risco de recidiva e ao final da fase de indução do tratamento (D29), 70,0% dos pacientes alcançaram a remissão. Os pacientes portadores de LLA T apresentaram média de idade (10,6 anos; p= 0,0204) e leucometria (48.200/mm3; p= 0,0167) significativamente mais altas do que os pacientes com LLA B. 80,0% dos pacientes expressaram o marcador CD56 e nenhum paciente expressou o CD16 e/ou o CD57. Os pacientes que não expressaram o marcador CD56 tinham idade significativamente maior daqueles que o expressaram (9,3 anos; p= 0,0353). Para os pacientes portadores de LLA B, a média de blastos do SP dos pacientes que expressaram o marcador CD56 foi maior do que a média dos que não o expressaram (41,1; p= 0,0226). Conclui-se que a expressão do CD56 sugere um pior prognóstico para os pacientes com LLA B, em virtude de uma média significativamente maior de blastos contados no SP encontrada no nosso estudo, contudo, um maior número de casos e um maior tempo de observação seriam necessários para enfatizar melhor esta evidência.
25

Gene Expression and DNA Methylation in Acute Lymphoblastic Leukemia

Nordlund, Jessica January 2012 (has links)
Pediatric acute lymphoblastic leukemia (ALL) is the most common malignancy in children, which results from the malignant transformation of progenitor cells in the bone marrow into leukemic cells. The precise mechanisms for this transformation are not well defined, however recent studies suggest that aberrant regulation of gene expression or DNA methylation may play an important role. Hence, the aim of this thesis was to use novel methods to investigate genome-wide gene expression and DNA methylation patterns in a large collection of primary ALL cells from pediatric patients. With these studies, we aimed to increase the understanding of factors that regulate gene expression and DNA methylation in ALL. In the first study of the thesis we found that data obtained from genome-wide digital gene expression analysis enabled excellent cytogenetic subtype-specific classification of ALL cells and revealed new features of gene expression within the disease, such as prevalent antisense transcription and alternative polyadenylation. In the second study we used technology developed for large-scale single nucleotide polymorphism (SNP) genotyping for quantitative analysis of allele-specific gene expression (ASE), revealing widespread ASE in ALL cells. Analysis of DNA methylation in promoter regions of the genes displaying ASE using DNA-microarrays revealed frequent regulation of gene expression by DNA methylation. In the third study, using the same DNA methylation array, we identified differences in the DNA methylation patterns in ALL cells at diagnosis compared to healthy mononuclear cells from the bone marrow of the same children at remission. In the fourth study we measured the DNA methylation of >450,000 CpG sites across the genome in a large collection of ALL samples and non-leukemic control cells. We found that ALL cells displayed highly divergent DNA methylation patterns depending on their cytogenetic subtype and widespread regions of differential methylation were enriched for repressive histone marks. DNA methylation levels at distinct regions in the genome were substantially increased at relapse compared to matched cells from diagnosis. Collectively, the results presented in this thesis provide new insights into the patterns of gene expression and epigenetic changes in ALL and further increase our understanding of the development and progression of the disease, which will hopefully lead to better treatment options in the future.
26

Influência da punção lombar traumática e da quimioterapia intratecal na sobrevida de pacientes pediátricos com leucemia linfocítica aguda

Rech, Ângela January 2005 (has links)
Introdução e Objetivos: O sistema nervoso central (SNC) é o um sítio freqüente de recaída na criança com leucemia linfocítica aguda (LLA). Existe evidência de que a punção lombar traumática (PLT) pode representar um risco adicional de recaída no SNC quando ocorre inoculação de blastos no liqüido céfalorraquidiano (LCR). Este estudo tem por objetivo determinar se a ocorrência da PLT ao diagnóstico afeta o prognóstico de pacientes com essa patologia. Material e Métodos: Setenta e sete pacientes com diagnóstico de LLA, tratados entre 1992 a 2002, foram incluídos na análise. Quimioterapia intratecal (QIT) foi instilada imediatamente após a PL inicial (precoce), ou na segunda PL (tardia), realizada no período de 24 a 48 horas após a realização da PL inicial. Foi feita análise da influência da PLT e do momento (precoce x tardia) de administração da QIT em relação a recaída no SNC. Resultados: Entre os 19 pacientes que apresentaram PLT ao diagnóstico e receberam QIT tardia, seis tiveram recaída isolada no SNC e dois recaída combinada em SNC e medula óssea (MO). Entre os nove pacientes que tiveram PLT e receberam QIT precoce, somente um apresentou recaída combinada em SNC e MO (P=0,20); não houve, portanto, influência estatisticamente significativa da PLT na sobrevida livre de eventos (SLE) (55% para QIT precoce x 49% para QIT tardia) (P=0,37). Entretanto, em análise estratificada, de acordo com grupos de risco, observamos que para pacientes de baixo ou médio risco o OR foi de 0,8 quando recebiam QIT tardia (P=0,99) e 0,17 quando recebiam QIT precoce (P=0,47). Por outro lado, entre pacientes de alto risco o OR para recaída foi de 21,0 para aqueles que recebiam QIT tardia (P=0,09) e 1,5 para o grupo que recebia Q IT precoce (P=0,99). Conclusão: Os resultados do presente estudo são sugestivos de que a ocorrência da PLT tem uma influência adversa no prognóstico de pacientes com LLA de alto risco de recaída. Como estes resultados são decorrentes de um estudo retrospectivo, recomenda-se que sejam confirmados em estudos prospectivos randomizados. / Introduction and Objectives: The Central Nervous System (CNS) is a frequent site of relapse in childhood acute lymphoblastic leukemia (ALL). Traumatic lumbar puncture (TLP) is thought to increase the risk of relapse in the CNS. This study sought to determine if TLP at the time of diagnosis affected the outcome of patients. Matherial and Methods: Seventy-seven newly diagnosed patients treated from 1992 to 2002 were included in the analysis. Intrathecal therapy (IT) was instilled either immediately after the diagnostic LP (early) or at a second LP (delayed) 24 to 48 hours following the diagnostic LP procedure. The authors carried out an analysis of the influence of TLP and the timing (early versus late) of administration of IT therapy on CNS relapse. Results: Among the 19 patients who had a TLP at diagnosis and received late IT therapy, six had isolated CNS relapse and two had combined CNS and bone marrow (BM) relapse. Among the nine patients who had TLP and received early IT therapy, only one had a combined CNS and BM relapse (P=0.20); the influence of TLP was not statistically significant on the event-free survival (EFS) (55% for early IT versus 49% for delayed IT) ( P =0.37). However, when we carried out a stratified analysis according to risk categories we found that for low and standard risk patients the odds ratio (OR) for relapse was 0.8 for delayed IT therapy (P=0.99) and 0.17 for early IT (P=0.47). On the other hand, among high risk (HR) patients the OR for relapse was 21.0 for delayed IT therapy (P=0.09) and 1.5 for early IT (P=0.99). Conclusion: The occurrence of TLP impacts adversely on prognosis of HR ALL patients. As these results are based in a retrospective study with a low number of patients, the authors recommend future trials using prospective randomized studies to confirm these findings.
27

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
28

Influência da punção lombar traumática e da quimioterapia intratecal na sobrevida de pacientes pediátricos com leucemia linfocítica aguda

Rech, Ângela January 2005 (has links)
Introdução e Objetivos: O sistema nervoso central (SNC) é o um sítio freqüente de recaída na criança com leucemia linfocítica aguda (LLA). Existe evidência de que a punção lombar traumática (PLT) pode representar um risco adicional de recaída no SNC quando ocorre inoculação de blastos no liqüido céfalorraquidiano (LCR). Este estudo tem por objetivo determinar se a ocorrência da PLT ao diagnóstico afeta o prognóstico de pacientes com essa patologia. Material e Métodos: Setenta e sete pacientes com diagnóstico de LLA, tratados entre 1992 a 2002, foram incluídos na análise. Quimioterapia intratecal (QIT) foi instilada imediatamente após a PL inicial (precoce), ou na segunda PL (tardia), realizada no período de 24 a 48 horas após a realização da PL inicial. Foi feita análise da influência da PLT e do momento (precoce x tardia) de administração da QIT em relação a recaída no SNC. Resultados: Entre os 19 pacientes que apresentaram PLT ao diagnóstico e receberam QIT tardia, seis tiveram recaída isolada no SNC e dois recaída combinada em SNC e medula óssea (MO). Entre os nove pacientes que tiveram PLT e receberam QIT precoce, somente um apresentou recaída combinada em SNC e MO (P=0,20); não houve, portanto, influência estatisticamente significativa da PLT na sobrevida livre de eventos (SLE) (55% para QIT precoce x 49% para QIT tardia) (P=0,37). Entretanto, em análise estratificada, de acordo com grupos de risco, observamos que para pacientes de baixo ou médio risco o OR foi de 0,8 quando recebiam QIT tardia (P=0,99) e 0,17 quando recebiam QIT precoce (P=0,47). Por outro lado, entre pacientes de alto risco o OR para recaída foi de 21,0 para aqueles que recebiam QIT tardia (P=0,09) e 1,5 para o grupo que recebia Q IT precoce (P=0,99). Conclusão: Os resultados do presente estudo são sugestivos de que a ocorrência da PLT tem uma influência adversa no prognóstico de pacientes com LLA de alto risco de recaída. Como estes resultados são decorrentes de um estudo retrospectivo, recomenda-se que sejam confirmados em estudos prospectivos randomizados. / Introduction and Objectives: The Central Nervous System (CNS) is a frequent site of relapse in childhood acute lymphoblastic leukemia (ALL). Traumatic lumbar puncture (TLP) is thought to increase the risk of relapse in the CNS. This study sought to determine if TLP at the time of diagnosis affected the outcome of patients. Matherial and Methods: Seventy-seven newly diagnosed patients treated from 1992 to 2002 were included in the analysis. Intrathecal therapy (IT) was instilled either immediately after the diagnostic LP (early) or at a second LP (delayed) 24 to 48 hours following the diagnostic LP procedure. The authors carried out an analysis of the influence of TLP and the timing (early versus late) of administration of IT therapy on CNS relapse. Results: Among the 19 patients who had a TLP at diagnosis and received late IT therapy, six had isolated CNS relapse and two had combined CNS and bone marrow (BM) relapse. Among the nine patients who had TLP and received early IT therapy, only one had a combined CNS and BM relapse (P=0.20); the influence of TLP was not statistically significant on the event-free survival (EFS) (55% for early IT versus 49% for delayed IT) ( P =0.37). However, when we carried out a stratified analysis according to risk categories we found that for low and standard risk patients the odds ratio (OR) for relapse was 0.8 for delayed IT therapy (P=0.99) and 0.17 for early IT (P=0.47). On the other hand, among high risk (HR) patients the OR for relapse was 21.0 for delayed IT therapy (P=0.09) and 1.5 for early IT (P=0.99). Conclusion: The occurrence of TLP impacts adversely on prognosis of HR ALL patients. As these results are based in a retrospective study with a low number of patients, the authors recommend future trials using prospective randomized studies to confirm these findings.
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ExpressÃo da L-Selectina e do CD44 nas leucemias linfÃides agudas em crianÃas e dolescentes. / Expression of adhesion molecules L-selectin and CD44 in childhood acute lymphoblastic leukemia

Daniel Willian Lustosa de Sousa 10 September 2009 (has links)
IntroduÃÃo â AlteraÃÃes na expressÃo ou funÃÃo das molÃculas de adesÃo (MA) nas cÃlulas leucÃmicas podem contribuir para a evoluÃÃo e no comportamento biolÃgico das leucemias agudas. A expressÃo aumentada nas LLAs parece relacionar-se aos mecanismos de disseminaÃÃo extramedular dos linfoblastos, infiltraÃÃo do SNC e formaÃÃo de massas tumorais. Objetivos â Analisar a expressÃo da L-selectina e do CD44 nas LLAs em crianÃas e adolescentes. Avaliar os fatores prognÃsticos (idade, sexo, leucometria ao diagnÃstico, imunofenÃtipo, classificaÃÃo FAB, EGIL, Ãndice de DNA e resposta ao tratamento de induÃÃo) e as apresentaÃÃes extramedulares das LLAs e correlacionÃ-los com essas MA. Pacientes e MÃtodos â Foram avaliados 76 pacientes com LLA, tratados com o Protocolo GBTLI-LLA. O diagnÃstico foi baseado em critÃrios FAB, imunofenotÃpicos (EGIL) e citogenÃticos. A expressÃo das MA foi avaliada por citometria de fluxo, utilizando tripla marcaÃÃo. O anticorpo monoclonal CD45-PerCP (ImmunotechÂ) foi utlizado como marcador dos linfoblastos. O CD44-PE (Clone HP2/9 - ImmunostepÂ) e o CD62L-FITC (Clone HI62L - ImmunostepÂ) foram utilizados para a marcaÃÃo das MA. Para a anÃlise das amostras e o cÃlculo da intensidade mÃdia de fluorescÃncia foi utilizado o programa Cell Quest. Na anÃlise estatÃstica utilizou-se o software SPSS 16.0. A associaÃÃo entre as variÃveis, os fatores prognÃsticos e resposta foi realizada com os testes de Qui-quadrado, exato de Fisher e Mann-Whitney. Sobrevida global foi determinada por curvas Kaplan-Meier e teste log-rank. AnÃlise multivariada por modelo proporcional de Cox foi utilizada para assegurar a independÃncia dos fatores prognÃsticos. Resultados â A mÃdia de idade foi 6,3Â0,5 anos (5m -17a) e predominou o sexo masculino (65%). Ao diagnÃstico os achados clÃnicos foram: hepatomegalia (63%), esplenomegalia (58%) e linfadenomegalia (44%). A infiltraÃÃo SNC ocorreu em 6,6% dos casos e o alargamento de mediastino em 11,8%. Quanto ao risco, 54% eram baixo risco e 46% alto risco. A classificaÃÃo FAB determinou 83% como L1 e 17% L2. DiagnÃstico de LLA-B foi mais frequente (89,5%) e o da LLA-T em 10,5% dos pacientes. O subtipo EGIL mais prevalente foi B II e B III, 51,5% e 45% respectivamente. O IDNA &#8805; 1.16 foi encontrado em 19% dos pacientes e associou-se a bom prognÃstico. Na avaliaÃÃo do D8, 95% dos pacientes apresentaram contagem de blastos <1000/mm3 e leucÃcitos < 5.000/mm3. A taxa de remissÃo de induÃÃo foi de 95% e ocorreram 2,6% de Ãbitos na induÃÃo. Observou-se uma maior expressÃo do CD44 na LLA-T (87,5%/ IMF=150,44Â20,29), porÃm sem significÃncia estatÃstica. LLAs com massa tumoral apresentaram 84% de expressÃo do CD44, quando comparada a 52% das LLAs sem massa tumoral (p=0.01; OR=4,8). ExpressÃo aumentada da L-selectina na LLA-T (87,5%/IMF=272,33Â52,72) foi estatisticamente significante (p=0,004), comparado a LLA-B (54,5%/ IMF= 115,90Â12,75). NÃo houve correlaÃÃo entre os outros fatores prognÃsticos e essas MA. Na anÃlise multivariada as variÃveis de maior impacto para a sobrevida foram: a leucometria ao diagnÃstico, sexo, imunofenÃtipo T e a L-selectina. ConclusÃo â A expressÃo da L-selectina e do CD44 estÃo aumentadas nas LLAs estudadas, principalmente na LLA-T. O CD44 correlacionou-se com LLAs com massas tumorais e parece estar relacionado aos mecanismos de disseminaÃÃo extramedular dos linfoblastos / Introduction â Altered expression or function of adhesion molecules on leukemic blasts may contribute to the evolution of acute leukemia and its biological behavior. The elevated expression of adhesion molecules in ALL might be correlated with the extramedullary dissemination of blast cells, CNS involvement and leukemia tumor burden. Purpose â To analyze the expression of L-selectin and CD44 in ALL in children and adolescents. As well as to evaluate the prognostic factors (age, gender, initial leukocyte count, immunophenotype, FAB and EGIL classification, DNA index and early response to treatment) and the extramedullary presentation of ALL, to finally correlate the prognostic factors with these adhesion molecules. Patients and Methods â From November 2007 to November 2008, 76 patients with newly diagnosed ALL started on Brazilian GBTLI-ALL Protocol. The diagnosis was based on cytological, immunophenotypic, and cytogenetic methods. The mean fluorescence intensity (MFI) and the percentage of the adhesion molecules blasts cells was measured by flow cytometry using triple staining with McAb directly conjugated. CD45-PerCP positive cells were gated for blasts analysis. Anti-CD44-PE (Clone HP2/9 - ImmunostepÂ) and CD62L-FITC (Clone HI62L - ImmunostepÂ) were used to mark the adhesion molecules. The Cell Quest program was used for data acquisition and analysis. Statistical analysis was done by SPSS 16.0 Software. The association of features, prognosis and response to treatment was assessed by Chi-square, Fisher exact and Mann-Whitney tests. Overall survival curves were constructed by the Kaplan-Meier method and the log-rank test. Multivariate Cox regression analysis showed independent prognostic factors. Results â The mean age at diagnosis was 6.3Â0.5 years (range 9mo to 17yr) and 65% of them were boys. Clinical findings were hepatomegaly (63%), splenomegaly (58%), lymphadenopathy (44%). CNS involvement was detected in 6.6% of cases and mediastinal mass appeared in 11.8% of them. Patients were classified into low risk (54%) and high risk (46%). FAB classification identified 83% as L1 and 17% as L2. Immunophenotypically, 89.5% of patients were classified as B-lineage ALL and 10.5% as T-lineage ALL. The most frequent EGIL subtype was B common and pre-B-ALL (51.5% and 45.5%, respectively). DNA index greater than 1.16 was found in 19% of the patients and was associated with favorable prognosis. On the D8 evaluation, 95% of the patients had blast count lower than 1.000/mm3 and leukocyte count lower than 5.000/mm3. The remission induction rate was 95% and there was a rate of 2.6% of death during induction therapy. CD44 had greater expression to the rate of 87.5% in T-cell ALL (MFI=150.44Â20.29) with no statistical correlation. A significant positive correlation was demonstrated between 84% of CD44 expression and Leukemia burden tumor cases (p=0.01; OR=4.8). There was statistical correlation between L-selectin expression (87.5%/MFI=272.33Â52.72) and T-cell ALL (p=0,004). No significant correlation was detected between L-selectin and CD44 expression and other prognostic factors. Multivariate statistical analysis (adjusted for overall survival) indicated that initial leukocyte count, gender, T immunophenotype and L-selectin were independent factors. Conclusion â L-selectin and CD44 expressions were elevated in ALL studied, mainly in T-cell ALL. The research demonstrated that there is an association between CD44 expression and leukemia tumor burden, which might be involved in the dissemination of leukemic cells and the progression of the disease.
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Avaliação imunofenotipica, estudo do indice de DNA e de alterações moleculares em celulas blasticas de pacientes portadores de leucemia linfoide aguda diagnosticados na Fundação Hemope / Phnotipic and molecular features of acute lymphoblastic leukemia in Recife - PE

Mello, Mariana Rezende Bandeira de, 1980- 29 January 2007 (has links)
Orientador: Irene Lorand-Metze / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-10T07:46:16Z (GMT). No. of bitstreams: 1 Mello_MarianaRezendeBandeirade_M.pdf: 649822 bytes, checksum: e4b6cfab44c011f4863c0df41c725ca1 (MD5) Previous issue date: 2007 / Resumo: A Leucemia Linfóide Aguda (LLA) representa 75-80% dos casos de leucemia em crianças e apenas 20% das leucemias do adulto. Certas características clínicas e laboratoriais têm valor prognóstico e servem para estratificá-los em grupos de risco para tratamento. O diagnóstico da LLA é baseado principalmente nas suas características fenotípicas que permitem definir a linhagem, o grau de maturação, bem com, assincronismos de maturação que permitem diferenciar blastos leucêmicos de precursores linfóides normais, o que é muito útil na detecção de doença residual mínima. Nosso objetivo foi estudar as características biológicas da LLA (características fenotípicas, moleculares e ploidia) em pacientes (adultos e crianças) atendidos na Fundação Remope. Foram utilizados um painel de triagem de anticorpos monoclonais e 2 secundários (para LLA-B e LLA- T). Todos os casos foram analisados no Paint-a-Gate para estudo da intensidade média de ~uorescência (IMF). Pesquisamos os rearranjos BCR/ABL p190 e p210, AF4/MLL, E2A/PBXl e TEL/AMLl. Foram analisados 49 pacientes onde 18 eram crianças (:S 18 anos) e 31 adultos (> 18 anos). Dos casos estudados 11 foram LLA- T (6 préT e 5 LLA-T) com mediana de idade de 19 anos. E 38 foram LLA-B (7 pré-pré-B, 15 B comum e 13 pré B e 3 sem classificação) com mediana de idade de 29 anos. O rearranjo BCR/ABL foi encontrado em 5 pacientes, sendo 4 BCR/ABL p190 e 1 BCR/ABL p210. Dois pacientes apresentaram o rearranjo E2A/fBXI e 2 o AF4/MLL. Não foi encontrado nenhum caso com o rearranjo TEL/AMLI. Quanto ao índice de DNA, 5 pacientes foram hiperdiplóides e 42 diplóides. A porcentagem de células em Fase S não variou entre crianças e adultos nem entre as LLAs B e T. Concluímos que os anticorpos utilizados foram suficientes para classificar imunologicamente os casos. A análise quantitativa expôs mais os assincronismos de maturação. A freqüência encontrada de casos hiperdiplóides foi semelhante à literatura. A taxa de proliferação foi muito variável, mas não teve relação com a idade, nem com o tipo de LLA. Os rearranjos encontrados apresentaram associação com os subtipos de LLA conforme descrito na literatura. Embora, a freqüência de adultos com BCR/ABL tenha sido abaixo da relatada / Abstract: Acute Lymphoblastic Leukemia (ALL) is a disease that occurs primarily in children (75-80%) and represents only 20% of adults' leukemia. Some c1inical and laboratorial research have focused on stratifying patients into various risk groups based on known prognostic features that play a critical role in directing therapy for ALL. We have studied biological characteristics of ALL (adults and children) of patients attended on Hemope Foundation from March 2004 to March 2006. The immunophenotyping at diagnosis was perfonned by a dual color two stage protocol. Expression of each antigen studied was measured by mean fluorescence intensity (MFI) by flow cytometry using the Paint-a-gate software. RT-PCR was perfonned to detect specific molecular alterations. We analyzed 49 patients: 18 children (:S 18 years old) and 31 adults. Eleven were T ALL with median age of 19 years and 38 were B ALL (7 pre-pre B, 15 common, 13 pre B and 3 without c1assification) :with median age of 29 years. Concerning gene rearrangements, BCR/ABL was detected in 5 patients (4 BCR/ABL p190 and 1 BCR/ABL p210), E2A/PBXl in 2 patients and AF4/MLL in 2 patients. TEL/AML1 couldn't be found in any case examined. Hyperdiploidy was observed in 5 patients. The percentage of cells in phase S showed a large variation, but did not differ in children or adults nor between B ALL and T ALL. Our results show that the antibodies used were sufficient to c1assify the cases. The quantitative approach was able to disclose better the maturation abnonnalities of the leukemic blasts. The frequency of hyperdiploid cases was similar to that found in the literature. The proliferation rate was variable but had no relationship with age and ALL type. The molecular aberrations were associated with specific ALL subtypes, as already described in the literature. Even so, the frequency of BCR/ABL in adults was diminished. / Mestrado / Ciencias Basicas / Mestre em Clinica Medica

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