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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

Prognostic and epidemiological factors in childhood leukaemia : studies of p53 and MDM2 expression and of space-time clustering /

Gustafsson, Britt, January 1900 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 6 uppsatser.
2

p53 alterations in human skin : a molecular study based on morphology /

Ling, Gao, January 1900 (has links)
Diss. (sammanfattning) Uppsala : Univ., 2001. / Härtill 4 uppsatser.
3

Alterações citogenômicas na medula óssea de trabalhadores rurais expostos a agrotóxicos

Ferreira Filho, Luiz Ivando Pires January 2013 (has links)
FERREIRA FILHO, Luiz Ivando Pires. Alterações citogenômicas na medula óssea de trabalhadores rurais expostos a agrotóxicos. 2013. Dissertação (Mestrado Ciências Médicas) - Universidade Federal do Ceará. Faculdade de Medicina, Fortaleza, 2013. / Submitted by denise santos (denise.santos@ufc.br) on 2014-02-17T12:21:59Z No. of bitstreams: 1 2013_dis_lipferreira filho.pdf: 2103165 bytes, checksum: 7ca3a3bd505574da57104d00a78b404d (MD5) / Approved for entry into archive by denise santos(denise.santos@ufc.br) on 2014-02-17T12:22:47Z (GMT) No. of bitstreams: 1 2013_dis_lipferreira filho.pdf: 2103165 bytes, checksum: 7ca3a3bd505574da57104d00a78b404d (MD5) / Made available in DSpace on 2014-02-17T12:22:47Z (GMT). No. of bitstreams: 1 2013_dis_lipferreira filho.pdf: 2103165 bytes, checksum: 7ca3a3bd505574da57104d00a78b404d (MD5) Previous issue date: 2013 / Os pesticidas são produtos químicos de uso disseminado no controle das pragas nas lavouras agrícolas. Estes produtos são classificados em herbicidas, inseticidas e fungicidas e podem acumular-se no meio ambiente. Um grande número de estudos epidemiológicos em trabalhadores rurais sugeriu um aumento do risco de câncer no grupo exposto a pesticidas. O objetivo deste estudo é avaliar a presença de anormalidades cromossômicas em células da medula óssea e alterações do gene TP53 por FISH em trabalhadores rurais expostos a pesticidas. Para o nosso conhecimento, este é o primeiro estudo a avaliar estas alterações utilizando células-tronco hematopoéticas coletadas por aspirado da medula óssea. Foram avaliados 43 trabalhadores rurais do sexo masculino e detectadas anormalidades cromossômicas através de citogenética por Banda G em 11 (25%). A maioria destas anomalias era relacionada com aneuploidias (6/11). Aneuploidias podem ocorrer devido a um cromossomo extra ou ausente. De extrema importância, encontramos quatro casos com anormalidades estruturais relacionadas aos cromossomos 4, 5, 7 e 11, como deleções do braço longo dos cromossomos 5, 7 e 11. Detectamos supressão do gene TP53 por Hibridização por Fluorescência in situ (FISH) em 4/31 e de amplificação em 3/31 casos. As outras alterações por FISH foram relacionadas à aneuploidia (6/31). Entre as anormalidades numéricas, encontramos tetrassomia em 3 casos, trissomia em dois casos e monossomia em um caso. Nosso trabalho é o primeiro a apresentar anomalias citogenéticas em células da medula óssea de trabalhadores rurais expostos a agrotóxicos. Nosso estudo destaca a importância da prevenção primária, pois apenas 23% dos trabalhadores rurais relatou medidas de proteção. Todas essas anormalidades citogenéticas aqui detectados são descritas como responsáveis por aumentar o risco de desenvolvimento de neoplasias. Como o uso de agrotóxicos está disseminado em nossa agricultura, os trabalhadores rurais devem evitar o uso impróprio devido ao risco de desenvolver neoplasias.
4

Polimorfismos do gene TP53 no linfoma de Hodgkin / TP53 gene polymorphisms in Hodgkin lymphoma

Viana, Daniel de Araújo January 2007 (has links)
VIANA, Daniel de Araújo. Polimorfismos do gene TP53 no linfoma de Hodgkin. 2007. 85 f. Dissertação (Mestrado em Patologia) - Universidade Federal do Ceará. Faculdade de Patologia, Fortaleza, 2007. / Submitted by denise santos (denise.santos@ufc.br) on 2011-12-21T11:21:30Z No. of bitstreams: 1 2007_dis_daviana.pdf: 2983687 bytes, checksum: a560463a3e70aa3380fd982718cb146f (MD5) / Approved for entry into archive by Eliene Nascimento(elienegvn@hotmail.com) on 2012-02-01T16:10:20Z (GMT) No. of bitstreams: 1 2007_dis_daviana.pdf: 2983687 bytes, checksum: a560463a3e70aa3380fd982718cb146f (MD5) / Made available in DSpace on 2012-02-01T16:10:20Z (GMT). No. of bitstreams: 1 2007_dis_daviana.pdf: 2983687 bytes, checksum: a560463a3e70aa3380fd982718cb146f (MD5) Previous issue date: 2007 / Hodgkin lymphoma is a hematololgic B neoplasm occurring at patients within any age, however more likely to affect those from 15 to 40 years-old. The TP53 gene is 20kb length gene with 11 exons that encodes the p53 protein, which main function is related to the conservation and integrity of the genetic code. Most cancers show point mutations in the TP53 sequence. The analysis of these mutations allows a better understanding of the function of the diverse domains of the protein and its relationship to tumor suppression. There is only a few data about TP53 polymorphisms and Hodgkin lymphoma. In this manner, in our study we try to detect polymorphisms within the codons 272, 273, 278, 282, 306 of the exon 8 of the TP53 gene in Hodgkin lymphoma. In our survey we analyzed 42 paraffin-embedded tissues from 2000 to 2006. These samples were prepared for DNA extraction and PCR isolation and amplification of the 137bp fragment of the exon 8 of the TP53 gene, using exclusive primers specially designed to our experiment: PFw8 e PRv8. After PCR amplification, the products of the reaction were purified to the Sequencing reaction. The last part of the experiment encoded the bioinformatics analysis of sequences. DNA extraction and PCR amplification were successfully obtained in our study in all the samples. However, the DNA sequencing was only obtained in 32 samples, but there was no characteristic electropherogram of the analyzed region of the gene. Therefore, it was not possible to determine the presence or absence of SNPs in the TP53 exon 8. / O Linfoma de Hodgkin é uma hemopatia linfóide pode ocorrer em qualquer faixa etária; no entanto, é mais comum na idade adulta jovem, dos 15 aos 40 anos. O TP53 é um gene de 20kb de comprimento que possui 11 éxons situado no cromossomo 17 e codifica a proteína p53, uma proteína cuja principal função está relacionada à preservação da integridade do código genético, e, durante o ciclo celular faz verificação quanto à eventual ocorrência de uma mutação na seqüência do código genético. Na presença dessas mutações, impede que esta célula entre em processo de mitose e complete a divisão celular. A maioria dos cânceres apresenta mutações pontuais na seqüência do TP53. A análise dos padrões dessas mutações é de grande valia uma vez que o conhecimento dessas mutações leva a um melhor entendimento das funções dos vários domínios da proteína p53 e seu envolvimento com o mecanismo de supressão tumoral, além de permitir que essas mutações sejam utilizadas como biomarcadores para desvendar a oncogênese humana. Na literatura vigente, poucos trabalhos abordam a identificação dessas mutações em relação ao linfoma de Hodgkin – forma clássica. Dessa forma, este trabalho se propõe a investigar quantitativa e qualitativamente os padrões de polimorfismos existentes nesta forma do linfoma de Hodgkin. A primeira etapa do nosso experimento constou da seleção de 42 casos de linfonodos diagnosticados como linfoma de Hodgkin entre os anos de 2000 e 2006, arquivados em blocos de parafina. Os casos foram selecionados de pacientes com diagnóstico de linfoma de Hodgkin, sem predileção por idade, sexo ou raça. Em seguida, o DNA foi extraído das amostras selecionadas para reação de PCR, realizada para isolar e amplificar, o fragmento de 137pb correspondente ao éxon 8 do gene TP53, através de primers exclusivos desenhados para o experimento: PFw8 e PRv8. Após a reação, os produtos de PCR foram purificados para reação de Seqüenciamento de DNA, utilizando o seqüenciador automático de DNA da marca ABI Prism® 3100 de 16 capilares (Applied Biosystems). A última etapa aconteceu em laboratório de bioinformática – dry lab, onde as seqüências de DNA obtidas foram analisadas qualitativa- e quantitativamente. Os processos de extração do DNA genômico, amplificação do éxon 8, purificação do produto de PCR foram realizadas com sucesso em todas as amostras obtidas de material parafinizado. No seqüenciamento do DNA parafinizado foi possível determinar, com segurança e confiabilidades previstas em parâmetros convencionais, a seqüência de pelo menos 32 amostras; contudo, não se obteve distinção suficiente dos picos de eletroferogramas para a determinação de eventuais polimorfismos na região analisada. Não foi possível portanto, verificar com margem de segurança razoável, a presença ou ausência de SNPs nas amostras seqüenciadas. Houve, contudo, uma qualificação e competência laboratorial instalada localmente (em Fortaleza), a partir da experiência desenvolvida com o esforço deste trabalho, para continuar a investigação molecular em prol da determinação, em futuro breve, da ocorrência ou não de SNPs no exon 8 do TP53 em linfoma de Hodgkin.
5

p53 and clusterin in photoreceptor cell death.

January 1998 (has links)
by Poon Hong Kit. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 129-161). / Abstract also in Chinese. / ACKNOWLEDGEMENTS --- p.i / ABSTRACT (ENGLISH/CHINESE) --- p.ii / ABBREVIATIONS --- p.vi / LIST OF TABLES --- p.vii / LIST OF FIGURES --- p.viii / TABLE OF CONTENTS --- p.x / INTRODUCTION --- p.1 / LITERATURE REVIEW --- p.4 / Chapter I. --- Models for studying photoreceptor cell death --- p.4 / Chapter II. --- Photic retinopathy --- p.5 / Chapter II.1. --- Proposed Mechanisms of Photic Retinopathy --- p.5 / Chapter II.2. --- Factors Affecting Photic Retinopathy --- p.6 / Chapter II.3. --- Pathologic Processes of Photic Retinopathy --- p.7 / Chapter III. --- P53 --- p.9 / Chapter III.1. --- Historical Perspective --- p.9 / Chapter III.2. --- Structure of p53 --- p.10 / Chapter III.2.1. --- The p53 Gene & mRNA --- p.10 / Chapter III.2.2. --- The p53 Protein --- p.10 / Chapter III.3. --- Modifications of p53 Protein --- p.13 / Chapter III.4. --- Functions of p53 --- p.14 / Chapter III.4.1. --- p53 & Tumors --- p.14 / Chapter III.4.2. --- p53 & DNA Damage --- p.15 / Chapter III.4.3. --- p53 & Apoptosis --- p.16 / Chapter III.4.3.1. --- p53-dependent Apoptosis --- p.16 / Chapter III.4.3.2. --- p53-independent Apoptosis --- p.20 / Chapter IV. --- clusterin --- p.22 / Chapter IV. 1. --- Historical Perspective --- p.22 / Chapter IV.2. --- Structure of Clusterin --- p.22 / Chapter IV.2.1. --- Clusterin Gene & mRNA --- p.22 / Chapter IV.2.2. --- Clusterin Protein --- p.22 / Chapter IV.3. --- Functions of Clusterin --- p.22 / Chapter IV.3.1. --- Clusterin & Apoptosis --- p.23 / OBJECTIVES --- p.24 / MATERIALS AND METHODS --- p.26 / Chapter V. --- Sample collections --- p.26 / Chapter V.l. --- Induction of Photic Injury in Rat --- p.26 / Chapter V.2. --- Tissue Processing --- p.26 / Chapter V.2.1. --- Paraffin-embedded Tissues --- p.26 / Chapter V.2.2. --- Epoxy-embedded Tissues --- p.27 / Chapter V.3. --- Cell Culture --- p.28 / Chapter VI. --- Light-microscopic study --- p.29 / Chapter VI. 1. --- Histopathology --- p.29 / Chapter VI.1.1. --- Toluidine Blue --- p.29 / Chapter VI. 1.2. --- Morphometry of the ONL Thickness --- p.29 / Chapter VI.2. --- In situ TUNEL --- p.29 / Chapter VI.2.1. --- Morphometry of TUNEL --- p.29 / Chapter VI.3. --- Immunohistochemistry --- p.30 / Chapter VI.3.1. --- Single-labeling --- p.30 / Chapter VI.3.1.1. --- Immunolabeling of p53 Protein --- p.31 / Chapter VI.3.1.2. --- Immunolabeling of p21 Protein --- p.31 / Chapter VI.3.1.3. --- Immunolabeling of bax Protein --- p.31 / Chapter VI.3.1.4. --- Immunolabeling of c-fos Protein --- p.32 / Chapter VI.3.1.5 --- Immunolabeling of Clusterin Protein --- p.32 / Chapter VI.3.2. --- Double-labeling --- p.32 / Chapter VI.3.2.1. --- TUNEL & Fluorescent-labeling of p53 --- p.32 / Chapter VI.3.2.2. --- TUNEL & Fluorescent-labeling of p21 --- p.33 / Chapter VI.3.3. --- Grading of Immunoreactivities --- p.33 / Chapter VI.3.4. --- Morphometry of c-fos Immuno-positive Nuclei --- p.33 / Chapter VI.4. --- In situ RT-PCR --- p.34 / Chapter VI.4.1. --- Isolation of Retinal DNA --- p.34 / Chapter VI.4.2. --- Polymerase Chain Reaction (PCR) --- p.34 / Chapter VI.4.3. --- In situ Reverse Transcriptase 226}0ؤ PCR (RT-PCR) --- p.35 / RESULTS --- p.37 / Chapter VII. --- LIGHT-MICROSCOPY --- p.37 / Chapter VII.1. --- Histopathology & Morphometry --- p.37 / Chapter VII. 1.1. --- Histopathology --- p.37 / Chapter VII.1.2. --- Morphometry of the ONL Thickness --- p.49 / Chapter VII.2. --- DNA Nicks Detection --- p.42 / Chapter VII.2.1. --- In situ TUNEL --- p.42 / Chapter VII.2.2. --- Morphometry of TUNEL --- p.42 / Chapter VII.3. --- p53 --- p.51 / Chapter VII.3.1. --- Immunohistochemistry of p53 --- p.51 / Chapter VII.3.2. --- Grading of p53 Immunoreactivities --- p.51 / Chapter VII.3.3. --- p53 in situ RT-PCR --- p.51 / Chapter VII.3.4. --- Double-labeling ofp53 with in situ TUNEL --- p.59 / Chapter VII.4. --- p21 --- p.74 / Chapter VII.4.1. --- Immunohistochemistry of p21 --- p.74 / Chapter VII.4.2. --- Grading of p21 Immunoreactivities --- p.74 / Chapter VII.4.3. --- Double-labeling of p21 with in situ TUNEL --- p.74 / Chapter VII.5. --- bax --- p.84 / Chapter VII.5.1. --- Immunohistochemistry of bax --- p.84 / Chapter VII.5.2. --- Grading of bax Immunoreactivities --- p.84 / Chapter VII.5.3. --- bax in situ RT-PCR --- p.84 / Chapter VII.6. --- c-fos --- p.96 / Chapter VII.6.1. --- Immunohistochemistry of c-fos --- p.96 / Chapter VII.6.2. --- Morphometry of c-fos immuno-positive nuclei & TUNEL --- p.96 / Chapter VII.7. --- Clusterin / Chapter VII.7.1. --- Immunohistochemistry of Clusterin --- p.108 / Chapter VII.7.2. --- Grading of Clusterin Immunoreactivities --- p.108 / discussion --- p.116 / Chapter VIII. 1. --- Summary --- p.116 / Chapter VIII.1.1. --- Histopathology & Morphometry --- p.118 / Chapter VIII.1.2. --- In situ TUNEL --- p.119 / Chapter VIII.1.3. --- p53 & c-fos --- p.119 / Chapter VIII.1.4. --- p27 --- p.124 / Chapter VIII.1.5. --- bax --- p.124 / Chapter VIII. 1.6. --- Clusterin --- p.124 / Chapter VIII.2. --- Hypothesis --- p.125 / Chapter VIII.3. --- Conclusion --- p.127 / bibliography --- p.129
6

The role of p53 in drug and interferon sensitivity of human osteosarcoma Saos-2 cells.

January 2004 (has links)
Wong Pak Cheung Ronald. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 121-142). / Abstracts in English and Chinese. / Acknowledgement --- p.I / Abstract --- p.II / Abbreviation --- p.VI / List of figures --- p.IX / List of tables --- p.XI / Content --- p.XII / Content / Chapter Chapter 1: --- General Introduction --- p.1 / Chapter 1.1 --- The p53 tumor suppressor gene --- p.2 / Chapter 1.1.1 --- Structure and function --- p.2 / Chapter 1.1.2 --- Regulation of p53 stability and activity --- p.3 / Chapter 1.1.3 --- p53 and cell cycle arrest --- p.4 / Chapter 1.1.4 --- p53 and apoptosis --- p.4 / Chapter 1.2 --- Mutation in p53 gene --- p.9 / Chapter 1.2.1 --- Loss of function through dominant negative effect --- p.9 / Chapter 1.2.2 --- Gain-of-function through transactivation by mutant p53 --- p.10 / Chapter 1.2.3 --- Mutation in p53 and resistance to cancer therapy --- p.10 / Chapter 1.3 --- Objective of the study --- p.14 / Chapter Chapter 2: --- Mutant p53 induced interferon resistance and its regulation of the Jak/Stat pathway --- p.15 / Chapter 2.1 --- Introduction --- p.16 / Chapter 2.1.1 --- IFN classification and biological activities --- p.16 / Chapter 2.1.2 --- IFN signaling --- p.17 / Chapter 2.1.3 --- IFN direct antitumor effect: cell cycle arrest and apoptosis --- p.18 / Chapter 2.1.4 --- IFN in immunotherapy --- p.20 / Chapter 2.1.5 --- Resistance to IFN therapy --- p.21 / Chapter 2.2 --- Materials and Methods --- p.24 / Chapter 2.2.1 --- Cell lines --- p.24 / Chapter 2.2.2 --- Drugs and antibodies --- p.24 / Chapter 2.2.3 --- Cell Proliferation assay- MTT assay --- p.24 / Chapter 2.2.4 --- Cell cycle analysis --- p.25 / Chapter 2.2.5 --- DNA fragmentation assay --- p.25 / Chapter 2.2.6 --- Western blot analysis --- p.26 / Chapter 2.2.7 --- "Combined treatment of IFNs and Jak inhibitors in MTT assay, DNA fragmentation assay and Western blot analysis" --- p.26 / Chapter 2.3 --- Results --- p.27 / Chapter 2.3.1 --- Mutant p53-V143A and p53-R273H induced IFN resistance: the role of IFN induced apoptosis and cell cycle arrest --- p.27 / Chapter 2.3.2 --- IFN induction of apoptosis: a p53-independent and caspase-dependent pathway --- p.28 / Chapter 2.3.3 --- Mutant p53 regulation of Jak/Stat pathway --- p.36 / Chapter 2.3.4 --- Janus kinases (Jaks) and IFN-alpha sensitivity in Saos-2 cells --- p.41 / Chapter 2.3.5 --- Janus kinases (Jaks) and IFN-gamma sensitivity --- p.49 / Chapter 2.4 --- Discussion --- p.56 / Chapter 2.4.1 --- Mutant p53-V143 and p53-R273H induced IFN resistance in Saos-2 cells --- p.56 / Chapter 2.4.2 --- Role of Jaks in IFN sensitivity in Saos-2 cells --- p.57 / Chapter 2.4.3 --- IFN signaling in Saos-2 cells --- p.57 / Chapter 2.4.4 --- Jak2 and IFN induced apoptosis --- p.58 / Chapter Chapter 3: --- Mutant p53 induced drug resistance --- p.60 / Chapter 3.1 --- Introduction --- p.61 / Chapter 3.1.1 --- The multidrug resistance (MDR) --- p.61 / Chapter 3.1.2 --- Anticancer drugs used in the study: action mechanisms and resistance --- p.67 / Chapter 3.1.3 --- Jak/Stat pathway and MDR --- p.68 / Chapter 3 .2 --- Materials and Methods --- p.72 / Chapter 3.2.1 --- Cell lines --- p.72 / Chapter 3.2.2 --- Drugs and antibodies --- p.72 / Chapter 3.2.3 --- Caspase 3 activity assay --- p.72 / Chapter 3.2.4 --- Cell Proliferation assay- MTT assay --- p.73 / Chapter 3.2.5 --- Cell cycle analysis --- p.73 / Chapter 3.2.6 --- DNA fragmentation assay --- p.73 / Chapter 3.2.7 --- Reverse transcription polymerase chain reaction --- p.73 / Chapter 3.2.8 --- Western blot analysis --- p.74 / Chapter 3.2.9 --- "Combined treatment of IFNs and Jak inhibitors in MTT assay, DNA fragmentation assay and Western blot analysis" --- p.74 / Chapter 3.3 --- Results --- p.75 / Chapter 3.3.1 --- Mutant p53 and drug sensitivity --- p.75 / Chapter 3.3.2 --- Mutant p53 and drug induced apoptosis and cell cycle arrest --- p.75 / Chapter 3.3.3 --- Classical drug resistance factors in mutant p53 induced drug resistance --- p.87 / Chapter 3.3.4 --- The role of Jaks in drug sensitivity of Saos-2 cells --- p.89 / Chapter 3.3.5 --- The role of Jaks in drug induced DNA fragmentationin Saos-2 cells --- p.89 / Chapter 3.3.6 --- Jak signaling and caspase activation in MTX induced apoptosis in Saos-2 cells --- p.100 / Chapter 3.3 --- Discussion --- p.108 / Chapter 3.3.1 --- Mutant p53-V143A and p53-R273H induced drug resistance in Saos-2 cells --- p.108 / Chapter 3.3.2 --- Role of Jaks in drug sensitivity in Saos-2 cells --- p.109 / Chapter 3.3.3 --- Jak/Stat signaling in Saos-2 cells --- p.109 / Chapter 3.3.4 --- Jak2 and MTX induced apoptosis --- p.110 / Chapter Chapter 4: --- General discussion --- p.112 / Chapter 4.1 --- Mutant p53 induced immunotherapy and chemotherapy resistance --- p.113 / Chapter 4.2 --- Gain of new function of mutant p53-V143A and p53-R273H in regulating Jak/Stat pathway leading to resistance to IFN and chemotherapeutic drugs --- p.114 / Chapter 4.3 --- The role of Jaks in MTX sensitivity --- p.114 / Chapter 4.4 --- Future work --- p.115 / Chapter 4.5 --- Perspective --- p.120 / References --- p.121
7

Eicosapentaenoic acid (EPA) induced apoptosis in human hepatoma cells through p53 pathway. / CUHK electronic theses & dissertations collection

January 2002 (has links)
Chi Tian-yi. / "July 2002." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (p. 213-257). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
8

Expressão de p53 e relação clínico-patológica no adenocarcinoma de reto

Jurach, Márcia Teresinha January 2003 (has links)
O adenocarcinoma colorretal é um dos tumores malignos mais freqüentes no mundo ocidental. Sua incidência varia mundialmente; nos Estados Unidos (EUA), é o terceiro câncer mais comum entre os homens e o segundo mais comum entre as mulheres, sendo a segunda causa de morte por câncer, superada apenas pelo tumor de pulmão. No Brasil, está entre as seis neoplasias mais freqüentes, ocupando a quarta posição em mortalidade. Os principais indicadores prognósticos do adenocarcinoma colorretal incluem a diferenciação histológica, profundidade de invasão e ocorrência de metástases. Recentemente, têm sido realizados diversos estudos usando técnicas de biologia molecular objetivando a identificação de novos parâmetros prognósticos. Entre estes, os fatores que regulam o ciclo celular influenciando no crescimento e mecanismo de apoptose têm demonstrado resultados promissores. O p53 é um gene supressor de tumores, localizado no braço curto do cromossomo 17; produz uma proteína chamada p53. Sua principal função é controlar pontos de checagem do ciclo celular, promover o reparo do DNA através do estímulo de outras proteínas (p21, por exemplo) e estimular a apoptose. Mutações deste gene produzem uma proteína p53 inativa que acumula nas células tumorais. A expressão desta proteína alterada é detectada em 30 a 70% dos tumores de reto e pode estar relacionada a mau prognóstico. O p53 é um dos genes mais comumente mutados no câncer humano. O objetivo deste estudo foi correlacionar a expressão imuno-histoquímica da proteína p53 com variáveis clínico-patológicas do adenocarcinoma de reto e sobrevida. Foram estudados 83 casos de pacientes operados no Hospital de Clínicas de Porto Alegre entre 1985 e 1997 através de reação imunohistoquímica utilizando anticorpo monoclonal Pab-1801 em amostras biológicas fixadas em formalina e armazenadas em blocos de parafina. Com um ponto de corte de 5%, 44 pacientes (53%) demonstraram expressão imunohistoquímica da proteína p53 maior que 5% e, com um ponto de corte de 20%, 36 pacientes (43,4%) demonstraram a expressão maior que 20%. Não houve associação estatisticamente significativa entre a expressão de p53 e as variáveis idade, gênero, localização, tamanho do tumor e comprometimento circunferencial. Encontramos associação entre p53 e óbito, recidiva local, metástases e recidiva total quando utilizado o ponto de corte de 20%, indicando um pior prognóstico nos pacientes com p53 positivos. Na análise multivariada em relação à sobrevida, o p53 teve poder prognóstico independente em relação às variáveis da classificação Astler- Coller e grau de diferenciação histológica da neoplasia. / Colorectal carcinoma is one of the most prevalent solid tumours in the western world. In the United States is the third most frequent neoplasia in men and the second most frequent in women. In Brazil, it is among the six more common neoplasms; it is ranked fifth in mortality. The main prognostic indicators of colorectal adenocarcinoma are histological differentiation, depth of invasion and metastatic involvement. Recently, many studies in molecular biology have been carried out aiming the identification of new prognostic parameters. The factors that regulate cell cycle implicated in cell growth and apoptosis have been shown promising results. P53 is a suppressor gene, located on the short arm of chromossome 17; the product of the p53 gene is a protein also called p53. Its main function on cell proliferation includes regulation of the transition from G1 to S phase as a checkpoint control factor and promotion of the DNA repair through stimulation of another protein (p21) and indution of apoptosis. Mutation of this gene produces loss of p53 function and leads to accumulation into cell. P53 mutation is detected in 30% to 70 % of rectal tumors and it is related with poor prognosis. P53 is the most frequent mutated gene on human cancer. The aim of this study was to determine the correlation of the immunohistochemical p53 expression with clinical and pathological variables and to determine its prognosis value on rectal carcinoma. We study 83 patients operated on Hospital de Clínicas de Porto Alegre during 1985 to 1997. Pab-1801 monoclonal antibodies againts p53 was used in formaline samples fixed. A total of 44 (53%) cases showed p53 expression, wit a cutoff of 5% and 36 (43,4%) cases, with cutoff of 20%. We did not find any association of p53 expression with age, gender, tumour site, grade and mucus production at 5% cutoff. However, we did find association between p53 expression with survival and recurrence on 20% cutoff, clearly indicating poor prognosis in p53 positive patients. Multivariate analysis for survival, showed P53 expression a powerful prognosis independent factor in despite another variables like Astler-Coller system or differentiation tumors.
9

Análise molecular do gene p53 em pacientes com esofagite, metaplasia intestinal da cárdia e esôfago de Barrett

Pilger, Diogo Andre January 2006 (has links)
Resumo não disponível
10

Avaliação dos genes MLL, RB e TP53 em pacientes com síndrome mielodisplásica / Evaluation of genes MLL, RB and TP53 in patients with Myelodysplastic Syndromes

Lima, Diego Silva January 2011 (has links)
LIMA, Diego Silva. Avaliação dos genes MLL, RB e TP53 em pacientes com síndrome mielodisplásica. 2011. 95 f. Dissertação (Mestrado em Patologia) - Universidade Federal do Ceará. Faculdade de Medicina, Fortaleza, 2011. / Submitted by denise santos (denise.santos@ufc.br) on 2013-12-03T12:56:53Z No. of bitstreams: 1 2011_dis_dslima.pdf: 4024143 bytes, checksum: 0a18d4cb329d542975fac3641f5bbd03 (MD5) / Approved for entry into archive by denise santos(denise.santos@ufc.br) on 2013-12-03T12:59:05Z (GMT) No. of bitstreams: 1 2011_dis_dslima.pdf: 4024143 bytes, checksum: 0a18d4cb329d542975fac3641f5bbd03 (MD5) / Made available in DSpace on 2013-12-03T12:59:05Z (GMT). No. of bitstreams: 1 2011_dis_dslima.pdf: 4024143 bytes, checksum: 0a18d4cb329d542975fac3641f5bbd03 (MD5) Previous issue date: 2011 / Myelodysplastic syndromes (MDS) represent a heterogeneous group of clonal disorders affecting the hematopoietic pluripotent cell, characterized by low cell counts in peripheral blood, dysplasia in one or more cell lines, inefficient hematopoiesis and increased risk of progression to acute myeloid leukemia. Although the disease can affect patients of other age groups, they are more frequent in those with advanced age with an average 60 to 75 years at diagnosis. Chromosomal abnormalities are observed in approximately 50% of all cases of MDS and are related with clinical and morphological findings. The aim of this study was to determine, through the technique of FISH (fluorescence in situ hybridization), the frequency of changes involving the MLL, RB, and TP53 genes in patients with MDS and associate these changes with cytogenetic findings. The cases included in the study were selected in the ambulatory of SMD from University Hospital Walter Cantídio. Thirty three patients were selected, 17 had aged over 60 years. 52% of patients were classified, according to WHO criteria, as refractory cytopenia with dysplasia in multiple lineages (RCDM) and 61% stratified, according to IPSS, as intermediate risk 1 (INT-1). 78% of patients had abnormalities detected by cytogenetics, among them 31% had complex karyotypes (more than 3 changes per metaphase). 18% of patients had changes at least in one of the three genes valued in this study by FISH. Three patients showed alterations of TP53 gene, being detected in two patients (records 31 and 6) the deletion of a single allele or both alleles of the gene, respectively, and in the third (record 2), we detected amplification of TP53 gene, all this changes were not detected by classical cytogenetics, because it is a less sensitive technique. 6% of patients (records 7 and 22) had rearrangement of MLL gene. In the first case, FISH discarded the gene deletion alleged by cytogenetic, proving that it was present in the genome of the patient, but in a rearranged form, and in the second case cytogenetics failed to demonstrate rearrangement of the gene. For the RB gene, FISH identified only one patient (3%) with deletion of one allele of the gene, and this change was also not detected by classical cytogenetics. During evaluating the TP53 gene, FISH allowed identification of two patients (records 5 and 10) presenting at least six extra copies of chromosome 17, probably representing a small hyperdiploid clone partially detected in the first patient and not detected in the second . In the six patients who showed abnormalities of the genes analyzed, FISH has provided information that added, changed or confirmed the result previously given by classical cytogenetics, which are a major application of this technique due to its high sensitivity compared to the traditional method. / As síndromes mielodisplásicas (SMD) representam um grupo heterogêneo de doenças clonais que acometem a célula precursora hematopoética pluripotente, caracterizando-se por baixa contagem de células no sangue periférico, displasia em uma ou mais linhagens celulares, hematopoese ineficiente, além do risco aumentado de progressão para leucemia mielóide aguda. Embora a doença possa acometer pacientes de outras faixas etárias, é mais frequente naqueles com idade avançada, com média ao diagnóstico de 60 a 75 anos. As anormalidades cromossômicas são observadas em aproximadamente 50% de todos os casos de SMD, estando, em alguns casos, relacionadas com achados clínicos e morfológicos. O objetivo deste trabalho foi determinar, através da técnica de FISH (hibridização in situ por fluorescência), a frequência de alterações envolvendo os genes MLL, RB e TP53 em pacientes com SMD e associar estas alterações com os achados citogenéticos. Os casos inseridos no estudo foram oriundos do ambulatório de SMD do Hospital Universitário Walter Cantídio. Dos 33 pacientes selecionados, 17 pertenciam ao grupo com idade acima de 60 anos. 52% dos pacientes foram classificados, segundo a OMS, como citopenia refratária com displasia em múltiplas linhagens (CRDM) e 61% estratificados, segundo o IPSS, como de risco intermediário 1 (INT-1). Um total de 78% dos pacientes apresentaram alterações citogenéticas, dentre eles 31% possuíam cariótipos complexos (mais de 3 alterações por metáfase). A técnica de FISH permitiu identificar em 18% dos pacientes alterações envolvendo um dos três genes avaliados. Três pacientes apresentaram alteração do gene TP53, sendo detectada em dois deles (registros 31 e 6) a deleção de um único alelo ou de ambos os alelos do gene, respectivamente, e no terceiro (registro 2), detectou-se a amplificação do gene TP53, sendo estas alterações não visualizadas através da citogenética clássica, por se tratar de um técnica menos sensível. Detectou-se em 6% dos pacientes (registros 7 e 22) rearranjo do gene MLL, no primeiro a FISH descartou a suposta deleção do gene alegada pela citogenética, provando que o mesmo estava presente no genoma do paciente, porém de forma rearranjada e no segundo a citogenética não conseguiu demonstrar o rearranjo do gene. Quanto ao gene RB, a FISH permitiu identificar apenas um paciente (3%) com deleção de um dos alelos do gene, sendo esta alteração também não detectada pela citogenética clássica. A FISH possibilitou identificar, durante a avaliação do gene TP53, dois pacientes (registros 5 e 10) apresentando pelo menos 6 cópias extras do cromossomo 17, devendo essa alteração se tratar de um pequeno clone hiperdiplóide detectado parcialmente no primeiro paciente e não detectado no segundo. Nos seis pacientes que apresentaram alteração dos genes avaliados, a FISH proveu informações que adicionaram, confirmaram ou alteraram o resultado previamente emitido pela citogenética clássica, sendo estas uma das principais aplicações desta técnica devido sua alta sensibilidade quando comparada ao método clássico.

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