Linfomas são cânceres provenientes da transformação de um linfócito no sistema linfático, sendo que, o mais comum é o Linfoma Não-Hodgkin (LNH). Avanços na imunologia e na biologia molecular têm auxiliado na detecção desses tumores e aberto caminhos para novas estratégias de tratamento, como a Radioimunoterapia. O rituximab é um anticorpo monoclonal quimérico anti-CD20 já utilizado como imunoterápico no tratamento de LNH refratários ou recidivos. O objetivo deste trabalho foi estudar a conjugação deste anticorpo ao quelante bifuncional DOTA-NHS-éster e radiomarcar este imunoconjugado com o radioisótopo 177Lu, com o objetivo de desenvolver um radioimunoterápico para tratamento de LNH. Estudos de imunoconjugação com diferentes razões molares rituximab:DOTA foram estudadas (1:5, 1:10, 1:20, 1:50, 1:250, 1:500 e 1:1000) afim de avaliar qual condição conferia maior pureza radioquímica. A estabilidade dos imuconjugados foi analisada por cromatografia de alta eficiência por até 240 dias em diferentes condições de armazenamento. A estabilidade do imuconjugado radiomarcado foi avaliada após incubação a 2-8 °C e em soro humano a 37 °C e a ligação às proteínas séricas foi determinada. Estudos de biodistribuição foram realizados em camundongos Swiss sadios a fim de caracterizar biologicamente o imunoconjugado radiomarcado. Com o objetivo de analisar se os processos de conjugação e de radiomarcação não danificaram a capacidade de reconhecimento do antígeno (imunorreatividade) deste anticorpo, realizou-se estudos preliminares de ligação às células de LNH (Raji). Os imuconjugados de razão molar baixa (1:5, 1:10 e 1:20) mostraram-se estáveis quando armazenados por até 240 dias em diferentes condições. A análise em cromatografia em camada delgada e CLAE, revelou que o Acm conjugado na razão molar 1:50 foi radiomarcado com alta pureza radioquímica (superior a 95%) quando purificado em coluna PD-10. Este mesmo radioimunoconjugado apresentou razoável estabilidade a 2-8° C. A análise da estabilidade em soro humano não indicou grande metabolismo pelas enzimas do soro. O radioimuconjugado apresentou alta ligação às proteínas séricas indicando clareamento sanguíneo lento, o qual foi confirmado pelos estudos in vivo. O radioimunoconjugado apresentou alta captação no fígado o que é característico de anticorpos monoclonais. Os estudos preliminares de competição indicaram que o processo de obtenção do radioimunoconjugado não prejudicou sua ligação às células Raji sendo esta ligação específica. / Lymphomas are tumors origened from the transformation of a lymphocyte in the lymphatic system. The most common lymphoma is the Non-Hodgkin Lymphoma (NHL). Advances in immunology and molecular biology have been improving NHLs detection and treatment strategies development, such as Radioimmunotherapy (RIT). Rituximab is an anti-CD20 monoclonal antibody used as immunotherapeutic to treat refractory or relapsed NHL. The goal of the present work was to conjugate this antibody to DOTA-NHS-ester bifunctional chelator and to radiolabel it with 177Lu radioisotope in order to develop a radioimmunotherapeutic agent for NHLs treatment. Different rituximab to DOTA molar ratios (1:5, 1:10, 1:20, 1:50, 1:250, 1:500 and 1:1000) were evaluated in order to determine the best condition for obtaining the highest radiochemical purity of radioimmunotherapeutic. The stability of the unlabeled immunoconjugated was evaluated by high performance liquid chromatography (HPLC) for up to 240 days in different storage conditions. The stability of the labeled preparations was evaluated either after storing at 2-8 °C or incubation in human serum at 37 °C. The binding to serum proteins was also determined. In vivo studies were performed in healthy Swiss mice, in order to characterize the biological properties of labeled conjugate. Finally, preliminary studies of radioimmunoconjugated competitive binding to CD20 positive Raji cells were carried out in order to analyze if the process of conjugation and radiolabeling compromises the immunoreactivity of the antibody. The conjugation applying lower antibody to chelator molar ratios (1:5, 1:10 and 1:20) showed high stability when stored for up to 240 days in different conditions. The HPLC analysis showed that the monoclonal antibody conjugated in molar ratio 1:50 was labeled with higher radiochemical purity (> 95%) when purified in PD-10 column. This conjugate showed reasonable stability at 2-8 ° C. The analysis of the stability in human serum did not suggest high metabolic degradation by serum enzymes. The labeled conjugate showed high serum protein binding, suggesting slow blood clearance, which was confirmed by in vivo studies. The labeled conjugate presented high uptake in the liver, in accordance to biodistribution pattern of monoclonal antibodies. The preliminary competitive binding studies indicated a specific binding and suggest that the synthesis of 177Lu-DOTA-rituximab did not compromise its binding to CD20 positive tumor cells.

No description available.

Ko Kin Ming Jeffery. / Thesis submitted in: July 2005. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 99-111). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Table of Contents --- p.ix / List of Tables --- p.xiii / List of Figures --- p.xv / List of Abbreviations --- p.xvi / Chapter Chapter 1: --- Introduction --- p.1 / Chapter 1.1 --- Malignant Lymphoma --- p.1 / Chapter 1.2 --- Non-Hodgkin's Lymphoma --- p.1 / Chapter 1.3 --- Diffuse Large B-cell Lymphoma --- p.2 / Chapter 1.3.1 --- General Features of Diffuse Large B-cell Lymphoma --- p.2 / Chapter 1.3.2 --- Morphologic variants of Diffuse Large B-cell Lymphoma --- p.4 / Chapter 1.3.2.1 --- Centroblastic vairant --- p.5 / Chapter 1.3.2.2 --- Immunoblastic variant --- p.5 / Chapter 1.3.2.3 --- Anaplastic variant --- p.6 / Chapter 1.3.3 --- Immunophenotype of Diffuse Large B-cell Lymphoma --- p.6 / Chapter 1.3.3.1 --- Lineage-associated antigens --- p.6 / Chapter 1.3.3.1.1 --- B-cell lineage antigens --- p.6 / Chapter 1.3.3.1.2 --- T-cell lineage antigens --- p.7 / Chapter 1.3.3.2 --- Antigen involved in regulation of cell proliferation and apoptosis --- p.8 / Chapter 1.3.3.2.1 --- Proliferation markers --- p.8 / Chapter 1.3.3.2.2 --- Cell cycle regulators --- p.8 / Chapter 1.3.3.2.3 --- Protein controlling apoptosis --- p.10 / Chapter 1.3.4 --- Subtypes of Diffuse Large B-cell Lymphoma --- p.10 / Chapter 1.3.4.1 --- Classification method of DLBCL subtypes --- p.11 / Chapter 1.3.4.1.1 --- DNA microarray --- p.11 / Chapter 1.3.4.1.2 --- Immunohistochemistry pattern --- p.14 / Chapter 1.3.4.1.2.1 --- CD10 --- p.16 / Chapter 1.3.4.1.2.2 --- Bcl-6 --- p.16 / Chapter 1.3.4.1.2.3 --- CD138 --- p.17 / Chapter 1.3.4.1.2.4 --- MUM1/IRF4 --- p.17 / Chapter 1.3.4.2 --- Prognosis of 、DLBCL subtypes --- p.19 / Chapter 1.4 --- Interleukin 10 --- p.22 / Chapter 1.4.1 --- The IL-10 gene --- p.23 / Chapter 1.4.2 --- IL-10 promoter --- p.23 / Chapter 1.5 --- IL-10 receptor --- p.24 / Chapter 1.6 --- Cellular Signaling Pathways Regulated by IL-10 --- p.25 / Chapter 1.6.1 --- Jak/Stat Pathway --- p.25 / Chapter 1.6.2 --- Inhibition of NF B pathway --- p.26 / Chapter 1.7 --- Function of IL-10 --- p.27 / Chapter 1.7.1 --- Effects of IL-10 on immune cells in vitro --- p.27 / Chapter 1.7.2 --- Effects of IL-10 on B-cells --- p.28 / Chapter 1.8 --- IL-10 and IL-10 receptor in malignant diseases --- p.29 / Chapter 1.8.1 --- Melanoma --- p.29 / Chapter 1.8.2 --- Carcinoma --- p.30 / Chapter 1.8.3 --- Lymphoma --- p.30 / Chapter 1.9 --- Single Nucleotide Polymorphism (SNP) --- p.33 / Chapter 1.9.1 --- SNPs in cancer research --- p.34 / Chapter 1.9.1.1 --- Susceptibility to cancer and SNPs --- p.35 / Chapter 1.9.1.2 --- Outcome and SNPs --- p.35 / Chapter 1.10 --- SNP in the IL-10 promoter --- p.36 / Chapter 1.11 --- IL-10 promoter SNP in DLBCL --- p.37 / Chapter Chapter 2: --- Aims of Study --- p.39 / Chapter Chapter 3: --- Materials and Methods --- p.41 / Chapter 3.1 --- Sample Recruitment --- p.41 / Chapter 3.2 --- DNA preparation for Single Nucleotide Polymorphism (SNP) analysis --- p.41 / Chapter 3.2.1 --- Isolation of Peripheral Blood Mononuclear Cell (PBMC) from buffy coat from blood of normal control group --- p.41 / Chapter 3.2.2 --- Preparation for NHL and DLBCL samples from paraffin-embedded sections for DNA extraction --- p.42 / Chapter 3.2.3 --- DNA extraction for SNP analysis --- p.42 / Chapter 3.3 --- SNP analysis by Restriction Fragment Length Polymorphism (RFLP) --- p.43 / Chapter 3.3.1 --- Amplification of target site by PCR --- p.43 / Chapter 3.3.2 --- SNP analysis --- p.45 / Chapter 3.4 --- Determination of haplotypic frequency --- p.50 / Chapter 3.5 --- Classification of DLBCL by immunohistochemistry --- p.50 / Chapter 3.5.1 --- Staining pattern of CD10 --- p.53 / Chapter 3.5.2 --- Staining pattern of Bcl-6 --- p.54 / Chapter 3.5.3 --- Staining pattern of CD138 --- p.55 / Chapter 3.5.4 --- Staining pattern of MUM1/IRF4 --- p.56 / Chapter 3.6 --- Statistical Analysis --- p.57 / Chapter Chapter 4: --- Results --- p.58 / Chapter 4.1 --- SNPs of IL-10 promoter in normal controls --- p.58 / Chapter 4.1.1 --- Allelic Frequencies and genotype distributions --- p.58 / Chapter 4.1.2 --- Haplotypic Frequencies of normal controls --- p.58 / Chapter 4.2 --- SNP of the IL-10 promoter in non-Hodgkin's lymphomas --- p.59 / Chapter 4.2.1 --- Allelic frequencies and genotype distributions --- p.59 / Chapter 4.2.2 --- Haplolypic frequencies --- p.61 / Chapter 4.4 --- SNPs of the IL-10 promoter in DLBCL --- p.62 / Chapter 4.4.1 --- Allelic frequencies and genotype distributions --- p.62 / Chapter 4.4.2 --- Haplotypic frequencies --- p.64 / Chapter 4.5 --- SNP of the IL-10 promoter in different subtypes of DLBCL --- p.65 / Chapter 4.5.1 --- Classification of DLBCL by immunohistochemistry --- p.65 / Chapter 4.5.2 --- SNP of the IL-10 promoter in Germinal Center DLBCL (GC-DLBCL) --- p.67 / Chapter 4.5.2.1 --- Allelic frequencies and genotype distributions --- p.67 / Chapter 4.5.1.2 --- Haplotypic frequencies --- p.69 / Chapter 4.5.2 --- SNP of the IL-10 promoter in Activated Germinal Center DLBCL (AGC-DLBCL) --- p.70 / Chapter 4.5.2.1 --- Allelic frequencies and genotype distributions --- p.70 / Chapter 4.5.2.2 --- Haplotypic frequencies --- p.72 / Chapter 4.5.3 --- SNP of the IL-10 promoter in Activated non-Germinal Center DLBCL (ANGC-DLBCL) --- p.73 / Chapter 4.5.3.1 --- Allelic frequencies and genotype distributions --- p.73 / Chapter 4.5.3.2 --- Haplotypic frequencies --- p.75 / Chapter 4.5.4 --- SNP of the IL-10 promoter in Unclassified DLBCL (UC-DLBCL). --- p.76 / Chapter 4.5.4.1 --- Allelic frequencies and genotype distributions --- p.76 / Chapter 4.5.4.2 --- Haplotypic frequencies --- p.78 / Chapter 4.6 --- Summary of SNP of the IL-10 promoter in DLBCL subtypes --- p.79 / Chapter 4.7 --- Overall survival analysis --- p.80 / Chapter 4.7.1 --- Clinical data of DLBCL --- p.80 / Chapter 4.7.2 --- Cox Proportional Hazards Regression Analysis in DLBCL --- p.81 / Chapter Chapter 5: --- Discussion --- p.88 / Chapter 5.1 --- SNP for low IL-10 production in Hong Kong population --- p.88 / Chapter 5.2 --- NHL in low IL-10 production population --- p.90 / Chapter 5.2.1 --- The relationship between IL-10 and NHL --- p.90 / Chapter 5.2.2 --- Allelic frequencies and haplotype of the IL-10 promoter in NHL --- p.90 / Chapter 5.3 --- Classification of DLBCL --- p.91 / Chapter 5.3.1 --- Current prognostic analysis --- p.91 / Chapter 5.3.2 --- DLBCL subtypes distribution in Hong Kong is different from Caucasian --- p.92 / Chapter 5.4 --- IL-10 and DLBCL --- p.93 / Chapter 5.5 --- SNP of IL-10 promoter in DLBCL subtypes --- p.94 / Chapter 5.5.1 --- Allelic frequencies and haplotype of DLBCL subtypes --- p.94 / Chapter 5.5.2 --- Rare haplotypes were discovered in DLBCL --- p.94 / Chapter 5.6 --- Overall survival Analysis --- p.95 / Chapter 5.6.1 --- Univariate Cox Proportional Hazards Regression Analysis --- p.95 / Chapter 5.6.2 --- Bivariate Cox Proportional Hazards Regression Analysis --- p.96 / Chapter Chapter 6: --- Conclusion --- p.97 / References --- p.99

L'objectif de notre travail est de mieux comprendre le rôle de LMP1 et de ses variants délétés de 30 ou 69pb en C-terminal dans le développement du lymphome de Hodgkin (LH) chez les patients VIH+. Le séquençage de LMP1 dans des échantillons de sang total et de cellules oropharyngées de patients de la cohorte Lymphovir (LH/VIH+) et de deux populations contrôles (VIH+ et LH) a permis d'étudier la fréquence des variants de LMP1 in vivo. Ce travail a révélé que le variant LMP1-del30 semble plus fréquent chez les patients avec une immunosuppression modérée, durant laquelle l'incidence des LH est élevée. Par ailleurs, nous avons établi un modèle cellulaire dérivé de LH, exprimant LMP1 de façon inductible, montrant des différences d'expression des cytokines et de progression du cycle cellulaire en fonction des variants de LMP1. Notre travail supporte l'hypothèse d'une plus grande oncogénicité du variant LMP1-del30 et suggère qu'il pourrait être un facteur de risque de développer un LH. / The aim of this work was to improve our understanding of the role of LMP1 and its 30bp and 69bp deletion variants in the development of Hodgkin's lymphoma (HL) among HIV+ people. Blood and saliva samples were collected from HL/HIV+ patients recruited in the Lymphovir cohort, as well as in two control populations (HIV+ and HL). Next-Generation Sequencing allowed us to determine the frequency of LMP1 variants in these samples. This work showed that the del30-LMP1 variant seems to be more frequent in patients with a moderate immunosuppression, associated with a higher HL incidence. Besides, we established three HL-derived cell lines expressing WT-LMP1 or its variants and showed differences of cytokine expression and progression of the cell cycle depending on the variant. Our work supports the hypothesis of a greater oncogenicity of del30-LMP1 variant and suggests that it could be a risk factor for the development of HL.

<p>The relationship between Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) is not entirely elucidated and a clonal relation may be present more often than previously believed. Mechanisms of tumour progression and resistance to therapy are poorly understood.</p><p>Between 1974 and 1994 all individuals in Sweden with both HL and NHL were identified. Thirty-two cases were studied using clinical, histopathological and immunohistochemical methods. The second lymphoma often appeared in an aggressive clinical form and a significant correlation between the expression of p53 and LMP-1 in the first and second lymphoma was demonstrated.</p><p>The treatment outcome for 307 patients with advanced stages of HL, in an unselected population was in accordance with the treatment results of large centres world-wide. Some patients were successfully selected for a shorter chemotherapy-regimen without inferior treatment results.</p><p>In 124 patients with relapse, the survival of those primarily treated with radiotherapy according to the National guidelines was in accordance with the survival of patients of initially advanced stages. A worse outcome was found for those who received both chemotherapy and radiotherapy initially, probably because of a higher frequency of bulky disease in this group. </p><p>Immunohistochemical analysis of the tumour suppressor protein p53 and retinoblastoma protein (Rb) of paired samples at diagnosis and at relapse in 81 patients did not reveal any specific staining pattern affecting survival.</p><p>A novel B-cell line (U-2932) was established from a patient with a diffuse large B-cell lymphoma previously treated for advanced stage and subsequent relapses of HL. An identical rearranged IgH gene was demonstrated in tumour cells from the patient and in U-2932. A p53 point mutation was detected and over-expression of the p53 protein was found. A complex karyotype with high-level amplifications of the chromosomal regions 18q21 and 3q27, i.e. the loci for <i>bcl-2</i> and <i>bcl-6</i> were demonstrated. </p>

The relationship between Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) is not entirely elucidated and a clonal relation may be present more often than previously believed. Mechanisms of tumour progression and resistance to therapy are poorly understood. Between 1974 and 1994 all individuals in Sweden with both HL and NHL were identified. Thirty-two cases were studied using clinical, histopathological and immunohistochemical methods. The second lymphoma often appeared in an aggressive clinical form and a significant correlation between the expression of p53 and LMP-1 in the first and second lymphoma was demonstrated. The treatment outcome for 307 patients with advanced stages of HL, in an unselected population was in accordance with the treatment results of large centres world-wide. Some patients were successfully selected for a shorter chemotherapy-regimen without inferior treatment results. In 124 patients with relapse, the survival of those primarily treated with radiotherapy according to the National guidelines was in accordance with the survival of patients of initially advanced stages. A worse outcome was found for those who received both chemotherapy and radiotherapy initially, probably because of a higher frequency of bulky disease in this group. Immunohistochemical analysis of the tumour suppressor protein p53 and retinoblastoma protein (Rb) of paired samples at diagnosis and at relapse in 81 patients did not reveal any specific staining pattern affecting survival. A novel B-cell line (U-2932) was established from a patient with a diffuse large B-cell lymphoma previously treated for advanced stage and subsequent relapses of HL. An identical rearranged IgH gene was demonstrated in tumour cells from the patient and in U-2932. A p53 point mutation was detected and over-expression of the p53 protein was found. A complex karyotype with high-level amplifications of the chromosomal regions 18q21 and 3q27, i.e. the loci for bcl-2 and bcl-6 were demonstrated.

Noise-like activity (NLA) refers to spontaneous subthreshold fluctuations in membrane potential. In this thesis, we examine the role that synaptic channel fluctuations play in contributing to NLA by comparing a detailed biophysical model to experimental data from whole-intact hippocampal interneurons. To represent the contribution from synaptic channel fluctuations, we switch the synapses in the model from traditional to Markovian formalisms and demonstrate statistically relevant increases the standard deviation; power-law scaling exponent; and power spectral density in the 5-100 Hz and 1-5 kHz ranges. However, while synaptic channel fluctuations have a definite effect, we found that they were significantly more subtle than the synaptic response to network activity. This indicates that synaptic channel fluctuations do indeed play a significant role in subthreshold noise, but, overall, synaptic NLA is dominated by the synaptic response to presynaptic network activity.

Noise-like activity (NLA) refers to spontaneous subthreshold fluctuations in membrane potential. In this thesis, we examine the role that synaptic channel fluctuations play in contributing to NLA by comparing a detailed biophysical model to experimental data from whole-intact hippocampal interneurons. To represent the contribution from synaptic channel fluctuations, we switch the synapses in the model from traditional to Markovian formalisms and demonstrate statistically relevant increases the standard deviation; power-law scaling exponent; and power spectral density in the 5-100 Hz and 1-5 kHz ranges. However, while synaptic channel fluctuations have a definite effect, we found that they were significantly more subtle than the synaptic response to network activity. This indicates that synaptic channel fluctuations do indeed play a significant role in subthreshold noise, but, overall, synaptic NLA is dominated by the synaptic response to presynaptic network activity.

No description available.

The study of neurons is of fundamental importance in biology and medicine. Neurons are the most basic unit of information processing in the nervous system of humans and all other vertebrates and in complex invertebrates. In addition, networks of neurons (the human brain) are the most sophisticated computational devices known, and the study of neurons individually and working in concert is seen as a step toward understanding consciousness and cognition. In the 1950's Hodgkin and Huxley developed a system of nonlinear ordinary differential equations to describe the behavior of a neuron found in the squid. Equations of this form have since been used to model the behavior of a multitude of neurons across a broad spectrum of species. Hodgkin-Huxley type neuron models helped lay the foundation for computational neuroscience, and they remain widely used in the study of neuron behavior almost sixty years after their development. Hodgkin-Huxley type models accept a set of parameters as input and generate data describing the electrical activity of the neuron as a function of time. We develop inversion algorithms to predict a set of input parameter values from the voltage trace data generated by the model. We test our algorithm on data from the Hodgkin-Huxley equations, and we extend the algorithm to solve the inverse problem associated with a more complex Hodgkin-Huxley type model for a lobster stomatogastric neuron. We find strong empirical evidence that the algorithms produce parameter values that generate a good fit to the target voltage trace, and we prove that under certain conditions the inversion algorithm for the Hodgkin-Huxley equations converges to a perfect match. To our knowledge this is the first parameter optimization procedure for which convergence has been shown theoretically. Understanding the relationship between the parameters of a neuron model and its output has implications for designing effective neuron models and for explaining the mechanisms by which neurons regulate their behavior. Inversion algorithms for Hodgkin-Huxley type neuron models are an important theoretical and practical step toward understanding the relationship between model parameters and model behavior, and toward the larger problem of inferring neuronal parameters from behavior observed experimentally.