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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.
1

Clonal Expansion of B and T lymphocytes Defines a Spectrum of Monoclonal Lymphocytosis

Memon, Sadaf 23 August 2011 (has links)
Monoclonal B lymphocytosis (MBL) has been recognized as a novel diagnostic condition. This study aims at the identification of clonal lymphocytosis in the patients with asymptomatic lymphocytosis. A total of 203 patients were evaluated for clonal B and T lymphocytosis by using flow cytometry and multiplex-PCR. Among them clonal B- or T-cells were detected in 54.2% of the cases, of which 38.4% were clonal B-cells and 15.8% were clonal T-cells cases. By immunophenotype, MBL was classified into the chronic lymphocytic leukemia (CLL) type (21.7%) and non-CLL-type (7.4%). Flow cytometry analysis and cell counts were used to determine the size of clonal population, and the data indicate that MBL and CLL are present in a continuous spectrum of clonal expansion. The findings may contribute to the current understanding of MBL and evaluation of incidental lymphocytosis. Further studies are required to evaluate clonal progression as a precursor stage of lymphoid malignancy.
2

Clonal Expansion of B and T lymphocytes Defines a Spectrum of Monoclonal Lymphocytosis

Memon, Sadaf 23 August 2011 (has links)
Monoclonal B lymphocytosis (MBL) has been recognized as a novel diagnostic condition. This study aims at the identification of clonal lymphocytosis in the patients with asymptomatic lymphocytosis. A total of 203 patients were evaluated for clonal B and T lymphocytosis by using flow cytometry and multiplex-PCR. Among them clonal B- or T-cells were detected in 54.2% of the cases, of which 38.4% were clonal B-cells and 15.8% were clonal T-cells cases. By immunophenotype, MBL was classified into the chronic lymphocytic leukemia (CLL) type (21.7%) and non-CLL-type (7.4%). Flow cytometry analysis and cell counts were used to determine the size of clonal population, and the data indicate that MBL and CLL are present in a continuous spectrum of clonal expansion. The findings may contribute to the current understanding of MBL and evaluation of incidental lymphocytosis. Further studies are required to evaluate clonal progression as a precursor stage of lymphoid malignancy.
3

Efeitos das moléculas ativadoras e inibidoras presentes em células T CD4+ convencionais e reguladoras na modulação da resposta imune durante a fase aguda da malária pelo Plasmodium chabaudi AS. / Effects of activating and inhibitory ,molecules present in conventional and regulatory CD4+ T cells on the modulation of the immune response during the acute phase of malaria by Plasmodium chabaudi AS.

Alves, Genoilson de Brito 29 July 2013 (has links)
A malária está entre as doenças mais prevalentes no mundo, acometendo aproximadamente 500 milhões de indivíduos por ano. Sabe-se que a resposta pró-inflamatória proporciona o controle da parasitemia, mas também desencadeia as manifestações clínicas que estão diretamente relacionadas aos casos fatais da doença. A utilização de modelos experimentais contribui para o conhecimento dos mecanismos intrínsecos relacionados à imunidade do hospedeiro. As análises em camundongos infectados com 106 eritrócitos parasitados pelo Plasmodium chabaudi AS mostram que, na fase aguda da malária, ocorre intensa proliferação com parasitemia detectável no dia 4 pós-infecção (p.i.), sendo o pico atingido no dia 7 p.i. e o declínio até o dia 10 p.i .. Acompanhando a cinética do parasita, observa-se o aumento no número de esplenócitos totais. A ativação do sistema imune caracterizasse pelo perfil de resposta Th1, com expansão da população de linfócitos T CD4+ convencionais e linfócitos T CD4+ Foxp3+ reguladores (Treg) e produção predominante de IFN-g. Nesse estudo, avaliamos em camundongos infectados com P. chabaudi AS: 1) O perfil de expressão das moléculas com papel fundamental na resposta imune nas células T CD4+ convencionais e Treg; 2) Os efeitos decorrentes da inibição in vitro das moléculas ICOS e OX40 presentes em ambas as populações celulares na resposta proliferativa a eritrócitos parasitados; 3) A atividade supressora das células Treg, sobre as células T CD4+ convencionais. Os resultados mostram que a partir do dia 4 p.i. ocorreu aumento na porcentagem de células T CD4+ convencionais e Treg, que expressavam as moléculas estimuladoras GITR, OX40 e ICOS. Observamos também que houve correlação entre a maior expressão da molécula CD25 com o aumento das outras moléculas ativadoras presentes nas células T CD4+ convencionais, o mesmo não sendo tão acentuado nas células Treg . Ao inibirmos a ação das moléculas ICOS e OX40, observamos que a inibição de ICOS interferiu de forma mais intensa na proliferação da população de células Treg , enquanto a inibição da molécula OX40 reduziu drasticamente a proliferação das células T CD4+ convencionais e Treg . Os ensaios de supressão indicaram que as células Treg ICOS+ são mais eficientes para controlar a proliferação das células T CD4+ convencionais. Além disso, observamos que, no baço dos camundongos infectados pelo P. chabaudi, ocorreu aumento na porcentagem de células T CD4+ convencionais que expressavam PD-1 e PD-L 1. No entanto, nas células Treg, detectamos diminuição na expressão de PD-1 e aumento de PD-L 1, fornecendo indícios sobre o mecanismo que pode estar envolvido no controle do número de células na fase aguda da infecção. Observamos ainda que, durante a expansão das células T CD4+, não houve modificações na porcentagem de células expressando a molécula CTLA-4 ou no nível de expressão desta molécula nos diferentes dias de infecção. Considerando os dados em conjunto, podemos concluir que a modulação da resposta imune à malária causada pelo P. chabaudi requer a ação de várias moléculas ativadoras e reguladoras, que muitas vezes são expressas de forma concomitante. A expressão orquestrada de cada uma dessas moléculas permite o desenvolvimento das várias etapas da resposta imune na malária. / Malaria is among the most prevalent diseases in the world, affecting approximately 500 million people per year. It is known that the pro-inflammatory response provides the control of parasitemia, but also triggers the clinical manifestations that are directly related to the fatal cases of the disease. The analyzes in mice infected with 106 erythrocytes parasitized with Plasmodium chabaudi AS show that, in the acute phase of malaria, there is an intense proliferation with detectable parasitemia on day 4 post-infection (p .i.), being the peak attained at day 7 p.i. and the decline until day 10 p.i .. Following the kinetics of the parasite, there is an increase in the total number of splenocytes. The activation of the immune system is characterized by a Th1 profile, with expansion of the populations of conventional CD4+ T cells and CD4+ Foxp3+ regulatory (Treg) T cells and predominant production of IFN-g. In this study, we evaluated in mice infected with P. chabaudi AS: 1} The expression profile of molecules with key roles in the immune responses of conventional CD4+ T cells and Treg cells; 2} The effects of in vitro inhibition of ICOS and OX40 molecules in the proliferative responses both cell populations that were stimulated with parasitized erythrocytes; 3} The suppressive activity of Treg cells on the conventional CD4+ T cells. The results showed that, from day 4 p.i. on, there was an increase in the percentages of conventional CD4+ T cells and Treg cells that expressed stimulatory GITR, OX40 and ICOS molecules. We also observed a correlation between the higher expression of CD25 with the increase of 0ther activation molecules that were present in conventional CD4+ T cells, a phenomenon less pronounced in Treg cells. By inhibiting the activity of ICOS and OX40 molecules, we observed that ICOS inhibition interfered more intensely in the proliferation of the Treg cell population, while the inhibition of OX40 dramatically reduced the proliferation of conventional CD4+ T cells and Treg cells. The suppression assays indicated that ICOS+ Treg cells were more effective to control the proliferation of conventional CD4+ T cells. Furthermore, we observed that, in the spleen of P. chabaudi-infected mice, there was an increase in the percentage of conventional CD4+ T cells expressing PD-1 and PD-L 1. However, in Treg cells, we detected a reduction in the expression of PD-1 and increase of PD-L 1, providing evidence about the mechanism that may be involved in the control of cell numbers in the acute phase of infection. We also observed that, during the expansion of CD4+ T cells, there was no change in the percentage of cells expressing CTLA-4 or the levei of expression of this molecule on the various days of infection. Considering the data together, we concluded that the modulation of the immune response to malaria caused by P. chabaudi requires the action of several activating and regulatory molecules, which are often expressed concomitantly. The orchestrated expression of each of these molecules allows the development of the various stages of the immune response to malaria.
4

Effects of a Simulated Tennis Match on Lymphocyte Subset Measurements

Kell, Holly 01 December 2010 (has links)
Research has shown that maximal exercise has a significant effect on cells of the immune system. Specifically, lymphocyte count increases during exercise and decreases to a value lower than baseline following an acute exhaustive bout of exercise. The overall lymphocyte response is well characterized, however, the ability of exercise to affect lymphocyte subfractions is unknown to our knowledge. The purpose of this study was to assess and evaluate the affects of a simulated tennis match across two sessions on lymphocyte subsets. Initial measurements such as age, height, weight, skinfold analysis, and heart rate were recorded for each player, as well as blood samples being obtained by a finger prick before and after the tennis sessions. The tennis protocol started with five serves to the deuce court and five serves to the ad court, then individuals hit twenty-four forehands and twenty-four backhands against an oscillating ball machine. Each bout of serves and ground strokes were repeated ten times, with one minute rests in between each session. Before and immediately after completing the tennis trial, subjects were pricked with a lancet on the non dominant hand so to obtain at least two capillary tubes of blood. Whole blood was then added to the antibody cocktail, which is mixed according to the antibodies that were tested, which were CD4, CD8, CD19, CD95, and CX3CR1. Whole blood was added to red blood cell lysis buffer and fixation buffer, and the blood solution was incubated with antibodies specific to cell phenotype. The main results of this study indicated that there was a decrease in mainly post cell counts in pre and post CD19/CD95 measurements (P= .007), an increase in CD8/CX3CR1 in pre counts and an increase then decrease in post counts without wearing the bionic glove (P= .042), and a decrease in CD4 in the post count measurement with the bionic tennis glove (P= .043). The study’s can assist in making recommendations for after match treatment such as health and diet suggestions. Knowledge of prevention and treatment methods are low in the field of tennis and immune functions, so findings in this area could prevent elite athletes from contracting infections between matches.
5

Efeitos das moléculas ativadoras e inibidoras presentes em células T CD4+ convencionais e reguladoras na modulação da resposta imune durante a fase aguda da malária pelo Plasmodium chabaudi AS. / Effects of activating and inhibitory ,molecules present in conventional and regulatory CD4+ T cells on the modulation of the immune response during the acute phase of malaria by Plasmodium chabaudi AS.

Genoilson de Brito Alves 29 July 2013 (has links)
A malária está entre as doenças mais prevalentes no mundo, acometendo aproximadamente 500 milhões de indivíduos por ano. Sabe-se que a resposta pró-inflamatória proporciona o controle da parasitemia, mas também desencadeia as manifestações clínicas que estão diretamente relacionadas aos casos fatais da doença. A utilização de modelos experimentais contribui para o conhecimento dos mecanismos intrínsecos relacionados à imunidade do hospedeiro. As análises em camundongos infectados com 106 eritrócitos parasitados pelo Plasmodium chabaudi AS mostram que, na fase aguda da malária, ocorre intensa proliferação com parasitemia detectável no dia 4 pós-infecção (p.i.), sendo o pico atingido no dia 7 p.i. e o declínio até o dia 10 p.i .. Acompanhando a cinética do parasita, observa-se o aumento no número de esplenócitos totais. A ativação do sistema imune caracterizasse pelo perfil de resposta Th1, com expansão da população de linfócitos T CD4+ convencionais e linfócitos T CD4+ Foxp3+ reguladores (Treg) e produção predominante de IFN-g. Nesse estudo, avaliamos em camundongos infectados com P. chabaudi AS: 1) O perfil de expressão das moléculas com papel fundamental na resposta imune nas células T CD4+ convencionais e Treg; 2) Os efeitos decorrentes da inibição in vitro das moléculas ICOS e OX40 presentes em ambas as populações celulares na resposta proliferativa a eritrócitos parasitados; 3) A atividade supressora das células Treg, sobre as células T CD4+ convencionais. Os resultados mostram que a partir do dia 4 p.i. ocorreu aumento na porcentagem de células T CD4+ convencionais e Treg, que expressavam as moléculas estimuladoras GITR, OX40 e ICOS. Observamos também que houve correlação entre a maior expressão da molécula CD25 com o aumento das outras moléculas ativadoras presentes nas células T CD4+ convencionais, o mesmo não sendo tão acentuado nas células Treg . Ao inibirmos a ação das moléculas ICOS e OX40, observamos que a inibição de ICOS interferiu de forma mais intensa na proliferação da população de células Treg , enquanto a inibição da molécula OX40 reduziu drasticamente a proliferação das células T CD4+ convencionais e Treg . Os ensaios de supressão indicaram que as células Treg ICOS+ são mais eficientes para controlar a proliferação das células T CD4+ convencionais. Além disso, observamos que, no baço dos camundongos infectados pelo P. chabaudi, ocorreu aumento na porcentagem de células T CD4+ convencionais que expressavam PD-1 e PD-L 1. No entanto, nas células Treg, detectamos diminuição na expressão de PD-1 e aumento de PD-L 1, fornecendo indícios sobre o mecanismo que pode estar envolvido no controle do número de células na fase aguda da infecção. Observamos ainda que, durante a expansão das células T CD4+, não houve modificações na porcentagem de células expressando a molécula CTLA-4 ou no nível de expressão desta molécula nos diferentes dias de infecção. Considerando os dados em conjunto, podemos concluir que a modulação da resposta imune à malária causada pelo P. chabaudi requer a ação de várias moléculas ativadoras e reguladoras, que muitas vezes são expressas de forma concomitante. A expressão orquestrada de cada uma dessas moléculas permite o desenvolvimento das várias etapas da resposta imune na malária. / Malaria is among the most prevalent diseases in the world, affecting approximately 500 million people per year. It is known that the pro-inflammatory response provides the control of parasitemia, but also triggers the clinical manifestations that are directly related to the fatal cases of the disease. The analyzes in mice infected with 106 erythrocytes parasitized with Plasmodium chabaudi AS show that, in the acute phase of malaria, there is an intense proliferation with detectable parasitemia on day 4 post-infection (p .i.), being the peak attained at day 7 p.i. and the decline until day 10 p.i .. Following the kinetics of the parasite, there is an increase in the total number of splenocytes. The activation of the immune system is characterized by a Th1 profile, with expansion of the populations of conventional CD4+ T cells and CD4+ Foxp3+ regulatory (Treg) T cells and predominant production of IFN-g. In this study, we evaluated in mice infected with P. chabaudi AS: 1} The expression profile of molecules with key roles in the immune responses of conventional CD4+ T cells and Treg cells; 2} The effects of in vitro inhibition of ICOS and OX40 molecules in the proliferative responses both cell populations that were stimulated with parasitized erythrocytes; 3} The suppressive activity of Treg cells on the conventional CD4+ T cells. The results showed that, from day 4 p.i. on, there was an increase in the percentages of conventional CD4+ T cells and Treg cells that expressed stimulatory GITR, OX40 and ICOS molecules. We also observed a correlation between the higher expression of CD25 with the increase of 0ther activation molecules that were present in conventional CD4+ T cells, a phenomenon less pronounced in Treg cells. By inhibiting the activity of ICOS and OX40 molecules, we observed that ICOS inhibition interfered more intensely in the proliferation of the Treg cell population, while the inhibition of OX40 dramatically reduced the proliferation of conventional CD4+ T cells and Treg cells. The suppression assays indicated that ICOS+ Treg cells were more effective to control the proliferation of conventional CD4+ T cells. Furthermore, we observed that, in the spleen of P. chabaudi-infected mice, there was an increase in the percentage of conventional CD4+ T cells expressing PD-1 and PD-L 1. However, in Treg cells, we detected a reduction in the expression of PD-1 and increase of PD-L 1, providing evidence about the mechanism that may be involved in the control of cell numbers in the acute phase of infection. We also observed that, during the expansion of CD4+ T cells, there was no change in the percentage of cells expressing CTLA-4 or the levei of expression of this molecule on the various days of infection. Considering the data together, we concluded that the modulation of the immune response to malaria caused by P. chabaudi requires the action of several activating and regulatory molecules, which are often expressed concomitantly. The orchestrated expression of each of these molecules allows the development of the various stages of the immune response to malaria.
6

Avaliação da expressão de miRNAs e comprimento telomérico em linfocitose B monoclonal e leucemia linfocítica crônica / microRNA expression and telome length analysis in monoclonal B-cell lymphocytosis and chronic lymphocytic leukemia

Furtado, Felipe Magalhães 02 October 2015 (has links)
Leucemia Linfóide Crônica (LLC) é a leucemia mais comum em países ocidentais, tem apresentação clínica e evolução heterogênea. Especula-se que todos os casos sejam precedidos por Linfocitose B Monoclonal (LBM). Não são bem conhecidos os mecanismos moleculares responsáveis por esta evolução. Alterações na expressão de miRNAs e em comprimento telomérico podem contribuir para desencadear esta neoplasia. O objetivo deste estudo foi identificar diferenças em comprimento telomérico e expressão de miRNAs entre pacientes com LLC, portadores de LBM clínica e populacional e controles saudáveis. Estudamos 21 pacientes com LLC, 11 portadores de LBM clínica, 6 de LBM populacional e 10 voluntários saudáveis. Para o controle de comprimento telomérico, utilizamos dados de estudo anterior do nosso serviço com grupo de 261 voluntários saudáveis de 0 a 86 anos. Realizamos separação de células CD19+CD5+ por citometria de fluxo nos grupos de estudo e de linfócitos B no grupo controle. Analisamos expressão dos miRNAs 15a, 16-1, 29b, 34a, 155, 181a e 181b por RT-qPCR e comprimento telomérico por qPCR. O miR- 155 foi o único que demonstrou expressão diferente entre os grupos LLC e LBM, sendo maior nos pacientes com LLC. Este miRNA e o miR-34a têm aumento de expressão nas células com fenótipo anormal, apesar desta diferença não ter tido significância estatística quando considerada a expressão do miR-155 na LBM. Os miRNAs 15a, 16-1, 181a e 181b são hipoexpressos nas células com fenótipo anormal. O miR-29b teve expressão semelhante nos grupos estudados. O comprimento telomérico foi semelhante nos 3 grupos de estudo e menor quando comparados ao grupo controle. O miR-155 tem diferente expressão em LBM e LLC, podendo ser um dos responsáveis por esta evolução. Alterações nos miRNAs 34a, 15a, 16-1, 181a e 181b contribuem para expansão clonal de linfócitos B CD5+. O papel do miR-29b na fisiopatogênese e evolução da LLC ainda não está bem definido. O comprimento telomérico diminuído em LLC e LBM pode fazer parte dos eventos iniciais da fisiopatogênese desta leucemia. / Chronic Lymphocytic Leukemia (CLL) is the most common leukemia on Western countries, it has an heterogeneous clinical presentation and outcome. Monoclonal BCell Lymphocytosis (MBL) may precede all CLL cases. The molecular mechanisms responsible for this evolution are not known. Aberrant miRNA expression and telomere shortening may contribute for the pathophysiology of this disease. The objective of this study was to identify differences on telomere length and miRNA expression between CLL patients, subjects with clinical and population-screening MBL and healthy volunteers. 21 CLL patients, 11 subjects with clinical MBL, 6 with population-screening MBL and 10 healthy volunteers were enrolled on this study. As control for telomere length, we used a group of 261 healthy volunteers aged 0 to 86 years old that had been enrolled on a previous study from our group. After diagnosis confirmation, it has been done a flow citometry CD19+CD5+ cell sorting for the study groups and CD19+ cell sorting for the control group. The expression of the miRNAs 15a, 16-1, 29b, 34a, 155, 181a and 181b was determined by RT-qPCR. The telomere length was determined by qPCR. miR-155 was the only one with different expression between the CLL and MBL groups, presenting higher expression on the CLL group. This miRNA and the miR-34a are overexpressed on the study groups when compared to the control group, although this difference did not reach statistical significance when the miR-155 expression in MBL is considered. miRNAs 15a, 16-1, 181a and 181b are underexpressed on the study groups. The miR-29b was the only one with similar expression on all groups. The telomere length was similar on the 3 study groups and shorter on these groups when compared to normal subjects. The expression of miR-155 is different in CLL and MBL, it may contribute for this evolution. Aberrant expression of miR 34a, 15a, 16-1, 181a and 181b may contribute for the clonal expansion of CD5+ B lymphocytes. The role of miR-29b on the CLL pathogenesis and evolution is still not understood. The reduced telomere length on CLL and MBL may be part of the initial events of this leukemia pathogenesis.
7

Avaliação da expressão de miRNAs e comprimento telomérico em linfocitose B monoclonal e leucemia linfocítica crônica / microRNA expression and telome length analysis in monoclonal B-cell lymphocytosis and chronic lymphocytic leukemia

Felipe Magalhães Furtado 02 October 2015 (has links)
Leucemia Linfóide Crônica (LLC) é a leucemia mais comum em países ocidentais, tem apresentação clínica e evolução heterogênea. Especula-se que todos os casos sejam precedidos por Linfocitose B Monoclonal (LBM). Não são bem conhecidos os mecanismos moleculares responsáveis por esta evolução. Alterações na expressão de miRNAs e em comprimento telomérico podem contribuir para desencadear esta neoplasia. O objetivo deste estudo foi identificar diferenças em comprimento telomérico e expressão de miRNAs entre pacientes com LLC, portadores de LBM clínica e populacional e controles saudáveis. Estudamos 21 pacientes com LLC, 11 portadores de LBM clínica, 6 de LBM populacional e 10 voluntários saudáveis. Para o controle de comprimento telomérico, utilizamos dados de estudo anterior do nosso serviço com grupo de 261 voluntários saudáveis de 0 a 86 anos. Realizamos separação de células CD19+CD5+ por citometria de fluxo nos grupos de estudo e de linfócitos B no grupo controle. Analisamos expressão dos miRNAs 15a, 16-1, 29b, 34a, 155, 181a e 181b por RT-qPCR e comprimento telomérico por qPCR. O miR- 155 foi o único que demonstrou expressão diferente entre os grupos LLC e LBM, sendo maior nos pacientes com LLC. Este miRNA e o miR-34a têm aumento de expressão nas células com fenótipo anormal, apesar desta diferença não ter tido significância estatística quando considerada a expressão do miR-155 na LBM. Os miRNAs 15a, 16-1, 181a e 181b são hipoexpressos nas células com fenótipo anormal. O miR-29b teve expressão semelhante nos grupos estudados. O comprimento telomérico foi semelhante nos 3 grupos de estudo e menor quando comparados ao grupo controle. O miR-155 tem diferente expressão em LBM e LLC, podendo ser um dos responsáveis por esta evolução. Alterações nos miRNAs 34a, 15a, 16-1, 181a e 181b contribuem para expansão clonal de linfócitos B CD5+. O papel do miR-29b na fisiopatogênese e evolução da LLC ainda não está bem definido. O comprimento telomérico diminuído em LLC e LBM pode fazer parte dos eventos iniciais da fisiopatogênese desta leucemia. / Chronic Lymphocytic Leukemia (CLL) is the most common leukemia on Western countries, it has an heterogeneous clinical presentation and outcome. Monoclonal BCell Lymphocytosis (MBL) may precede all CLL cases. The molecular mechanisms responsible for this evolution are not known. Aberrant miRNA expression and telomere shortening may contribute for the pathophysiology of this disease. The objective of this study was to identify differences on telomere length and miRNA expression between CLL patients, subjects with clinical and population-screening MBL and healthy volunteers. 21 CLL patients, 11 subjects with clinical MBL, 6 with population-screening MBL and 10 healthy volunteers were enrolled on this study. As control for telomere length, we used a group of 261 healthy volunteers aged 0 to 86 years old that had been enrolled on a previous study from our group. After diagnosis confirmation, it has been done a flow citometry CD19+CD5+ cell sorting for the study groups and CD19+ cell sorting for the control group. The expression of the miRNAs 15a, 16-1, 29b, 34a, 155, 181a and 181b was determined by RT-qPCR. The telomere length was determined by qPCR. miR-155 was the only one with different expression between the CLL and MBL groups, presenting higher expression on the CLL group. This miRNA and the miR-34a are overexpressed on the study groups when compared to the control group, although this difference did not reach statistical significance when the miR-155 expression in MBL is considered. miRNAs 15a, 16-1, 181a and 181b are underexpressed on the study groups. The miR-29b was the only one with similar expression on all groups. The telomere length was similar on the 3 study groups and shorter on these groups when compared to normal subjects. The expression of miR-155 is different in CLL and MBL, it may contribute for this evolution. Aberrant expression of miR 34a, 15a, 16-1, 181a and 181b may contribute for the clonal expansion of CD5+ B lymphocytes. The role of miR-29b on the CLL pathogenesis and evolution is still not understood. The reduced telomere length on CLL and MBL may be part of the initial events of this leukemia pathogenesis.
8

Molecular Characterization of a Recurrent t(2;7) Translocation Linking CDK6 to the IGK Locus in Chronic B-cell Neoplasia

Parker, Edward 27 June 2013 (has links)
Uncovering the chromosomal abnormalities associated with human malignancy can provide significant insights into the molecular basis of tumorigenesis, as well as identifying potential targets for therapy. The present study set out to examine the genetic characteristics of t(2;7)(p11-12;q21-22) translocations arising in conjunction with chronic B-cell neoplasia. Using long-range PCR, a t(2;7) was initially mapped in an individual presenting with the preclinical entity CD5- monoclonal B-cell lymphocytosis. This revealed a breakpoint at 2p11.2 localized to the recombination signal of the immunoglobulin kappa (IGK) variable gene IGKV3-15, and a breakpoint at 7q21.2 located 520 bp upstream of cyclin dependent kinase 6 (CDK6). The same approach was subsequently employed to elucidate near-identical t(2;7) breakpoints in 4 additional cases presenting with chronic lymphocytic leukemia or indolent non-Hodgkin lymphomas. The remarkable consistency of these translocations implicates the dysregulation of CDK6 via translocation to IGK as a recurrent pathomechanism during the emergence of B-cell lymphoproliferative disorders.
9

Molecular Characterization of a Recurrent t(2;7) Translocation Linking CDK6 to the IGK Locus in Chronic B-cell Neoplasia

Parker, Edward 27 June 2013 (has links)
Uncovering the chromosomal abnormalities associated with human malignancy can provide significant insights into the molecular basis of tumorigenesis, as well as identifying potential targets for therapy. The present study set out to examine the genetic characteristics of t(2;7)(p11-12;q21-22) translocations arising in conjunction with chronic B-cell neoplasia. Using long-range PCR, a t(2;7) was initially mapped in an individual presenting with the preclinical entity CD5- monoclonal B-cell lymphocytosis. This revealed a breakpoint at 2p11.2 localized to the recombination signal of the immunoglobulin kappa (IGK) variable gene IGKV3-15, and a breakpoint at 7q21.2 located 520 bp upstream of cyclin dependent kinase 6 (CDK6). The same approach was subsequently employed to elucidate near-identical t(2;7) breakpoints in 4 additional cases presenting with chronic lymphocytic leukemia or indolent non-Hodgkin lymphomas. The remarkable consistency of these translocations implicates the dysregulation of CDK6 via translocation to IGK as a recurrent pathomechanism during the emergence of B-cell lymphoproliferative disorders.

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