DNA methylation is an epigenetic mechanism that regulates the gene transcription. Folate is used in cellular synthesis of methyl groups, nucleic acids and amino acids. In complex diseases like cancer and neural tube defects (NTD), various genetic and epigenetic alterations can be found that disrupt the normal cell function. The main goals of this thesis were to analyze whether the genes responsible for the folate transport (FOLR1, PCFT, and RFC1) could be regulated by DNA methylation in placenta, blood leukocytes and colorectal cancer. We also addressed the genome-wide DNA methylation changes in colorectal cancer andcervical cancer.We found that changes in the methylated fraction of the RFC1 gene were dependent on the RFC1 80G>A polymorphism in placental specimens with NTDs and blood leukocytes from subjects with high homocysteine (Paper I). In colorectal cancer, the greatest difference in DNA methylation was observed in the RFC1 gene and was related to a lower protein expression (Paper II).In Paper III and IV we studied the DNA methylated fraction using a high-density array. Paper III was focused on genes in the DNA repair pathway and frequently mutated in colorectal cancer. We found that aberrant methylation in the DNA mismatch repair genes was not a frequent event in colorectal cancer and we identified five candidate biomarker genes in colorectal cancer, among them the GPC6 and DCLRE1C genes. In Paper IV, we found hypomethylation of genes involved in the immune system in cervical cancer specimens compared to healthy cervical scrapes and we identified twenty four candidate genes for further evaluation ofclinical value.In conclusion, the work of this thesis filled a relevant knowledge gap regarding the role of differential methylation of the folate transport genes in NTD and colorectal cancer. This thesis work also provided insights into the functional role of DNA methylation in cancer specific pathways and identified potential novel biomarker genes.

Made available in DSpace on 2015-07-22T20:49:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-18. Added 1 bitstream(s) on 2015-08-11T03:26:15Z : No. of bitstreams: 1 Publico-12957a.pdf: 1243731 bytes, checksum: 878db06d2872246e99cbd4358ee4a1d0 (MD5). Added 1 bitstream(s) on 2015-08-11T03:26:15Z : No. of bitstreams: 2 Publico-12957a.pdf: 1243731 bytes, checksum: 878db06d2872246e99cbd4358ee4a1d0 (MD5) Publico-12957b.pdf: 1376768 bytes, checksum: 4cdb6afbfd0e66e1d0fb5c0615f48744 (MD5) / A sepse apresenta crescente incidência com elevada morbidade e mortalidade, sendo a principal causa de óbito nas unidades de terapia intensiva. O controle da infecção depende do adequado reconhecimento dos microrganismos pelas células do hospedeiro e de resposta efetora competente. Os linfócitos, monócitos e neutrófilos são as principais populações celulares do sangue periférico envolvidas nesse processo. A apoptose representa um importante mecanismo de controle da resposta imune, mas em condições críticas, a apoptose desregulada dessas células pode levar o hospedeiro a imunossupressão, dificultando o controle da sepse. Este trabalho avaliou-se a porcentagem de apoptose em linfócitos monócitos e neutrófilos do sangue periférico de pacientes sépticos pela exposição de fosfatidilserina na superfície celular e pela detecção intracelular de caspase-3, também foi avaliado o número absoluto e percentual de linfócitos e suas subpopulações por citometria de fluxo. Foram incluídos 40 pacientes, sendo 4 em sepse, 9 em sepse grave e 27 em choque séptico, classificados de acordo com as definições do consenso de 1992. Quinze voluntários sadios foram incluídos para comparação. Nos ensaios de detecção de apoptose foi feita a separação dos leucócitos totais seguida de lise hipotônica das hemácias e marcação com anticorpos de superfície para identificação das populações leucocitarias. Para verificação da apoptose as amostras foram marcadas com anexina-V e coradas com Iodeto de Propídeo (PI) em tampão apropriado ou incubadas com anticorpo anti-caspase-3 após fixação e permeabilização. A contagem de linfócitos foi realizada em tubos TruCOUNT após a marcação com anticorpos anti-CD45, CD3, CD4, CD8, CD16/56 e CD19. Não houve diferença no percentual de linfócitos totais em apoptose, porém observou-se menor apoptose tardia em linfócitos T nos pacientes sépticos quando comparados aos sadios ( P<0,05). Foi observada menor contagem absoluta de linfócitos totais, linfócitos T, TCD4+, TCD8+ e NK de pacientes sépticos (p<0,01), embora o percentual destas populações celulares tenha se mantido inalterado. Os resultados mostram que o menor número de linfócitos circulantes observados durante o quadro de sepse não pôde ser explicado pela presença de apoptose. A diminuição da contagem destas células na periferia pode significar uma migração para os tecidos ou órgãos linfóides desencadeada pela infecção. Nos neutrófilos não foi observada diferença no percentual de células em apoptose precoce entre pacientes e indivíduos sadios. Houve queda no percentual de apoptose tardia e conseqüente aumento no percentual de células viáveis dos pacientes em comparação aos sadios (p<0,05). Não se observou diferença significativa na mensuração intracelular de caspase 3 em neutrófilos de pacientes comparado a indivíduos sadios. A análise da apoptose durante a evolução da sepse não mostrou diferença entre os grupos D0, D7 e D14. Não houve diferença na proporção de células em apoptose entre pacientes com sepse que sobreviveram e pacientes que evoluíram a óbito até o vigésimo oitavo dia após o diagnóstico de sepse. A apoptose tardia em neutrófilos parece estar diminuída. O possível efeito biológico da redução de apoptose tardia seria uma resposta adaptada à lesão, talvez prolongando a meia vida e atividade dos neutrófilos, entretanto, essa apoptose diminuída pode contribuir para a lesão inflamatória sistêmica e predispor o desenvolvimento da síndrome de disfunção de múltiplos órgãos. Os monócitos foram avaliados unicamente pela detecção intracelular de caspase-3, todavia, não foi encontrado diferença entre pacientes sépticos e indivíduos sadios. O mesmo ocorreu em amostras obtidas na admissão, 7º e 14º dia de seguimento. O percentual de monócitos com positividade para caspase-3 nos dias 0, 7 e 14 de sepse foi relacionado com a evolução dos pacientes em sobreviventes e óbitos, após 28 dias do diagnóstico. A análise realizada com amostras do D0 não indicou diferença na porcentagem de células apoptóticas entre os pacientes sobreviventes e que evoluíram a óbito. Entretanto, o percentual de apoptose observado no D7 mostrou que pacientes que evoluíram a óbito apresentaram menor porcentagem de células positivas para caspase-3 após 28 dias, e essa associação persistiu no seguimento de 60 e 180 dias. O papel da apoptose em monócitos parece ser muito importante na sepse, todavia são necessários novos estudos para elucidar a correlação entre apoptose de monócitos e sobrevida. / Sepsis incidence continues to rise with significant morbidity and mortality and is the leading cause of death in intensive care units. Infection control depends on proper recognition of the microorganisms by immune cells and an adequade effector immune response. Lymphocytes, monocytes and neutrophils are the major peripheral blood cell populations involved in this process. Apoptosis is an important mechanism for controlling the immune response, however, in critical conditions, deregulated apoptosis can lead to immune suppression, difficulting the control of sepsis. This study evaluated the percentage of apoptosis in peripheral blood derived lymphocytes, monocytes and neutrophils by means of exposure of phosphatidylserine on the cell surface and detection of intracellular caspase-3 and evaluated the absolute number and percentage of lymphocytes and their subpopulations by flow cytometry. Forty septic patients were included, of whom, 4 were septic, 9 presented severe sepsis and 27 were in septic shock, classified according to the definitions of the 1992´s consensus. Fifteen healthy volunteers’ were included for comparison. For apoptosis assays, total leucocytes were isolated from the whole blood by hypotonic lysis of the red blood cells and stained with surface antibodies in order to identify the leukocyte subpopulations. For apoptosis evaluation samples were stained with annexin-V and propidium iodide (PI) in an appropriate buffer or labeled with anti-caspase-3 after fixation and permeabilization. Lymphocyte counts were performed in TruCOUNT tubes after labeling the cells with anti-CD45, CD3, CD4, CD8, CD16/56 and CD19. There were no statistical differences in the percentage of apoptosis in total leukocytes, however, lower late apoptosis was observed in T lymphocytes of septic patients when compared to healthy subjects (P<0.05). Septic patients showed a smaller absolute count of total lymphocytes, T lymphocytes, CD4+, CD8+ and NK cells when compared to the healthy individuals (P<0.01), although the percentage of these cell populations has remained unchanged. These results demonstrate that the smallest number of circulating lymphocytes observed during sepsis could not be explained by the presence of apoptosis. The decrease of peripheral blood cell counts could be a result of the cell migration to the lymphoid tissues or organs triggered by infection. There were no differences in the percentage of early apoptosis in neutrophils of patients and healthy individuals. There was a decrease in the percentage of late apoptosis and a consequent increase in the percentage of viable cells in the patients when compared to the healthy subjects (P<0.05). There was no significant differences in the measurement of intracellular caspase-3 in neutrophils of patients compared to the healthy individuals. Analysis of apoptosis during the development os sepsis did not differ among the D0, D7 an D14 groups. There was no difference in the proportion of cells undergoing apoptosis between patients with sepsis who survived and those who died by the twenty-eight (D28) after the diagnosis of sepsis. Late apoptosis in neutrophils appears to be diminished. The possible biological effect of the reduction of apoptosis would be an adapted response to the injury, perhaps extending the half life and activity of neutrophils, however, this decreased apoptosis may contibute to inflammatory injury and predispose to the development of the multiple organ dysfunction syndrome. Only intracellular caspase-3 was evaluated in monocyte population, and no differences were found between this marker on septic patients and healthy individuals. The same results were observed in samples from adminssion, 7 and 14 days of follow-up. The percentage of monocytes with caspase-3 activity on days 0, 7 and 14 of sepsis was related to patient outcome as regards of survival and non-survival, after 28 days of diagnosis. The analysis performed on samples from D0 did not indicate differences in the percentage of apoptotic cells among the survivors and non-survivors. To counterpoint, when this analysis was performed on D7, the percentage of cells positive for caspase-3 were lower in those who died when compared with the survivors after 28 days; besides, this association persisted on 60 and 180 days follow-up. The role of apoptosis in monocytes seems to be important in sepsis, however, further research is needed to elucidate the correlation between monocyte apoptosis and survival. / TEDE

Made available in DSpace on 2014-06-11T19:31:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-06-30Bitstream added on 2014-06-13T18:41:44Z : No. of bitstreams: 1 pagnano_lo_dr_jabo.pdf: 626602 bytes, checksum: 91e708f2a8ad849761e7177151a3d66e (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O objetivo deste trabalho foi avaliar o potencial de cicatrização de uma fração de proteína extraída do látex da seringueira em diferentes concentrações (0,01% e 0,001%) associada a diferentes biomateriais (Fibracol plusÒ e ácido hialurônico a 1%). Utilizaram-se 36 coelhos albinos da raça Nova Zelândia Branco submetidos à realização de 4 feridas em cada orelha. Dividiu-se o experimento em etapas de acordo com a análise do período pós-operatório (3º, 7º, 14º e 21º dias), sendo utilizados 9 animais para cada etapa. Na primeira etapa (3º dia de pósoperatório), os animais foram numerados aleatoriamente de 1 a 9, sendo que em 3 animais, nas orelhas esquerdas, as feridas foram tratadas com solução salina (T1) e nas orelhas direitas, as feridas foram tratadas com membrana de Fibracol plus® + FrHb1 a 0,01% (T2). Em outros 3 animais, realizaram-se os mesmos procedimentos, diferenciando os tratamentos, onde nas feridas das orelhas esquerdas o tratamento foi com Fibracol plus® (T3) e nas feridas das orelhas direitas Fibracol plus® + FrHb1 a 0,001% (T4). Nos 3 animais restantes, seguiram-se os mesmos procedimentos, inserindo nas feridas das orelhas esquerdas ácido hialurônico a 1% + FrHb1 a 0,01% (T5) e nas feridas das orelhas direitas ácido hialurônico a 1% + FrHb1 a 0,001% (T6). Os animais foram sacrificados no 3º dia de pós-operatório e as feridas foram analisadas macroscopicamente e em seguida separadas para a análise histológica. Estes procedimentos foram repetidos para as etapas de 7, 14 e 21 dias de pós-operatório. Os segmentos de tecidos com as feridas foram fixados em solução de Bouin por 24 horas, e processados rotineiramente, para inclusão em paraplast e posterior avaliação histológica e morfométrica. A morfometria foi realizada por meio do sistema... / The aim of this study was to evaluate the potential for healing of a fraction of protein extracted from the latex of rubber trees in different concentrations (0.01% and 0.001%) associated with various biomaterials (Fibracol plus®1 and hyaluronic acid to 1%). There were used 36 New Zealand White rabbits underwent achievement of 4 wounds on each ear. The experiment was divided into stages according to the analysis of the postoperative period (3, 7, 14 and 21 days), and 9 animals used for each step. In the first stage (day 3 post-surgery), animals were randomly numbered from 1 to 9, with 3 animals in the left ear, the wounds were treated with saline (T1) and the right ear, the wounds were treated with membrane of Fibracol plus® + FrHb1 to 0.01% (T2). In 3 other animals, the same procedures were held, differing treatments, where the wounds of the left ear they were treated with Fibracol plus® (T3) and the wounds of the right ears Fibracol Plus® + FrHb1 to 0.001% (T4). In the 3 remaining animals, there was followed by the same procedures, including the ears wounds hyaluronic acid at 1% + FrHb1 to 0.01% (T5) and right ears wounds of hyaluronic acid 1% + FrHb1 a 0.001% (T6). The animals were sacrificed at 3 days postoperatively and the wounds were examined macroscopically and then separated for histological analysis. These procedures were repeated on the steps of 7, 14 and 21 days postoperatively. The segments of the injured tissues were fixed in Bouin solution for 24 hours and routinely processed for inclusion in paraplastic and subsequent histologic and morphometric evaluation. The morphometry was performed using the image analyzing system (Image Pro-PLUS2) and the evaluation of healing was done by enumeration of leukocytes and fibroblasts. The data were subjected to statistical analysis (ANOVA and Tukey test at 5%)... (Complete abstract click electronic access below)

Orientador: Aureo Evangelista Santana / Banca: Andrigo Barboza de Nardi / Banca: Ana Paula Massae Nakage Canesin / Banca: Paola Castro Moraes / Banca: Rosemeri de Oliveira Vasconcelos / Resumo: O presente estudo teve como objetivos avaliar seqüencial e temporalmente o quadro leucocitário de dez cães portadores de linfoma em remissão, submetidos à alta dose de ciclofosfamida, durante o uso do estimulador de colônia de granulócitos (GCSF, filgrastine) seguido ou não do transplante autólogo de medula óssea (TMO), bem como quantificar células CD34+ no sangue periférico dos referidos cães. Para tal avaliação foram utilizados três grupos experimentais, sendo o grupo 1 (G1) formado por cinco animais em remissão de linfoma que passaram por alta dose de ciclofosfamida e TMO seguido do uso de G-CSF; o grupo 2 (G2) formado por cinco animais em remissão de linfoma que sofreram alta dose de ciclofosfamida seguida do uso de G-CSF e o grupo 3 (G3) formado por dez animais saudáveis que receberam apenas o G-CSF. O transplante consistiu na colheita de medula óssea, preparo e congelamento da bolsa que continha células medulares em suspensão, condicionamento do paciente com 500mg/m2 de ciclofosfamida, infusão das células hematopoéticas e aplicação do G-CSF. Para avaliar a recuperação hematopoética pós-transplante foi realizado leucograma e análise citométrica do sangue nos dias 7, 8, 9, 10 e 11 após condicionamento. O nadir médio dos neutrófilos segmentados (NS) no grupo com transplante de medula óssea (G1) foi 425 NS/mL, e no grupo sem TMO (G2) foi 637,4 NS/μL e ocorreu sete dias após alta-dose de quimioterápico em ambos os grupos. A duração média da neutropenia foi de três dias. Nenhum animal apresentou febre ou sepse após a alta dose de ciclofosfamida. A dose de 5μg/kg/dia durante quatro dias de filgrastine foi insuficiente na mobilização adequada de células CD34+ nos três grupos estudados, sendo necessários novos estudos para este propósito. Desta maneira, pode-se comprovar o fato de que o uso do G-CSF leva a reduções significativas na incidência... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aims of this research were to provide an analysis of several counts of leucocytes values in dogs with lymphoma in remission phase, undergone to high-dose chemotherapy with cyclophosphamide, during treatment with granulocyte colonystimulating factor (G-CSF, filgrastine), followed or not by autologous bone marrow transplantation (BMT), as well to quantify CD34+ cells of peripheral blood from that dogs. For this purpose, three experimental groups were considered. Five dogs in clinical remission undergone to high-dose chemotherapy with cyclophosphamide and BMT, followed by G-CSF use were included in group 1 (G1), while group 2 (G2) was consisted by five dogs undergone to high-dose chemotherapy with cyclophosphamide, followed by G-CSF. Group 3 (G3) was composed of ten healthy dogs undergone to GCSF only. Transplantation consisted of bone marrow harvest, managing and freezing bags containing lifted marrow cells, cyclophosphamide conditioning (500mg/m2), hematopoietic cells infusion and treatment with G-CSF. After transplantation, hematopoietic recovery was evaluated by means of leukograms and flow cytofluorimetrical analysis on days 7, 8, 9, 10 and 11 after conditioning. Mean nadir neutrophil (NS) counts in group undergone transplantation (G1) was 425 NS/mL versus 637,4 NS/μL in group without BMT (G2). Nadir was observed on the seventh day after high-dose chemotherapy in both groups and neutropenia mean time was three days. Fever or sepsis was not observed in any dog after high-dose cyclophosphamide. Four days of filgrastine treatment in dose of 5μg/Kg, daily, was not enough to mobilize CD34+ cells appropriately in three groups analyzed, requiring new studies for this purpose. Considering these results, it is possible to conclude that G-CSF significantly reduces the incidence, severity and duration of neutropenia / Doutor