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Id: biblio-915440
Autor: Gonzalez, Raul S; Washington, Kay; Shi, Chanjuan.
Título: Current applications of molecular pathology in colorectal carcinoma
Fonte: Appl. cancer res;37:1-13, 2017. ilus.
Idioma: en.
Resumo: Molecular pathology is playing an increasingly important role in the treatment and overall management of patients with colorectal carcinoma. Three distinct genetic pathways have been identified that play a role in carcinogenesis: the chromosomal instability pathway, the microsatellite instability pathway, and the CpG island methylator phenotype pathway. Certain genetic mutations, some of which overlap with the aforementioned pathways, can also indicate that a carcinoma patient has a genetic predisposition syndrome, such as familial adenomatous polyposis, Lynch syndrome, and hamartomatous polyposis syndromes. A variety of advanced methods, including next-generation sequencing, are available to test for these and other mutations, such as targetable mutations that may allow tailoring of a treatment regimen to a patient's specific cancer (e.g., KRAS and BRAF mutations). The possible future role of testing circulating tumor cells is also addressed. New mutations and syndromes continue to be discovered, ensuring that our knowledge of colorectal carcinoma and our ability to treat it will advance in the future (AU)
Descritores: Síndromes Neoplásicas Hereditárias
Neoplasias Colorretais/genética
Instabilidade Cromossômica
Patologia Molecular
Carcinogênese
Limites: Humanos
Masculino
Feminino
Adulto
Pessoa de Meia-Idade
Idoso
Idoso de 80 Anos ou mais
Tipo de Publ: Revisão
Responsável: BR30.1 - Biblioteca


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Texto completo SciELO Brasil
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Id: lil-713677
Autor: Borgonovo, Tamara; Vaz, Isadora May; Senegaglia, Alexandra Cristina; Rebelatto, Carmen Lucia Kuniyoshi; Brofman, Paulo Roberto Slud.
Título: Genetic evaluation of mesenchymal stem cells by G-banded karyotyping in a Cell Technology Center
Fonte: Rev. bras. hematol. hemoter;36(3):202-207, May-Jun/2014. tab, graf.
Idioma: en.
Projeto: Conselho Nacional de Pesquisa; . Conselho Nacional de Pesquisa; . Conselho Nacional de Pesquisa.
Resumo: OBJECTIVE: To present the initial results of first three years of implementation of a genetic evaluation test for bone marrow-derived mesenchymal stem cells in a Cell Technology Center. METHODS: A retrospective study was carried out of 21 candidates for cell therapy. After the isolation of bone marrow mononuclear cells by density gradient, mesenchymal stem cells were cultivated and expanded at least until the second passage. Cytogenetic analyses were performed before and after cell expansion (62 samples) using G-banded karyotyping. RESULTS: All the samples analyzed, before and after cell expansion, had normal karyotypes, showing no clonal chromosomal changes. Signs of chromosomal instability were observed in 11 out of 21 patients (52%). From a total of 910 analyzed metaphases, five chromatid gaps, six chromatid breaks and 14 tetraploid cells were detected giving as total of 25 metaphases with chromosome damage (2.75%). CONCLUSION: The absence of clonal chromosomal aberrations in our results for G-banded karyotyping shows the maintenance of chromosomal stability of bone marrow-derived mesenchymal stem cells until the second passage; however, signs of chromosomal instability such as chromatid gaps, chromosome breaks and tetraploidy indicate that the long-term cultivation of these cells can provide an intermediate step for tumorigenesis. .
Descritores: Citogenética
Instabilidade Cromossômica
Células-Tronco Mesenquimais
Cariotipagem
Limites: Humanos
Masculino
Feminino
Responsável: BR408.1 - Biblioteca da Faculdade de Medicina - BFM


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Id: biblio-946998
Autor: Oliveira-Junior, Robson José de; Goulart Filho, Luiz Ricardo; Bastos, Luciana Machado; Alves, Dhiego de Deus; Silva, Sabrina Vaz dos Santos e; Morelli, Sandra.
Título: Contributions of cytogenetics to cancer research / Contribuições da citogenética em pesquisas sobre o câncer
Fonte: Biosci. j. (Online);30(1):245-259, jan./feb. 2014. tab, ilus.
Idioma: en.
Resumo: The two conflicting visions of tumorigenesis that are widely discussed are the gene-mutation hypothesis and the aneuploidy hypothesis. In this review we will summarize the contributions of cytogenetics in the study of cancer cells and propose a hypothetical model to explain the influence of cytogenetic events in carcinogenesis, emphasizing the role of aneuploidy. The gene mutation hypothesis states that gene-specific mutations occur and that they maintain the altered phenotype of the tumor cells, and the aneuploidy hypothesis states that aneuploidy is necessary and sufficient for the initiation and progression of malignant transformation. Aneuploidy is a hallmark of cancer and plays an important role in tumorigenesis and tumor progression. Aneuploid cells might be derived from polyploid cells, which can arise spontaneously or are induced by environmental agents or chemical compounds, and the genetic instability observed in polyploid cells leads to chromosomal losses or rearrangements, resulting in variable aberrant karyotypes. Because of the large amount of evidence indicating that the correct chromosomal balance is crucial to cancer development, cytogenetic techniques are important tools for both basic research, such as elucidating carcinogenesis, and applied research, such as diagnosis, prognosis and selection of treatment. The combination of classic cytogenetics, molecular cytogenetics and molecular genetics is essential and can generate a vast amount of data, enhancing our knowledge of cancer biology and improving treatment of this disease.

As duas visões conflitantes da tumorigênese que são amplamente discutidas são a hipótese da mutação gênica e a hipótese da aneuploidia. Nesta revisão vamos resumir as contribuições da citogenética no estudo das células tumorais e propor um modelo hipotético para explicar a influência dos eventos citogenéticos na carcinogênese, enfatizando o papel da aneuploidia. A teoria da mutação gênica estabelece que mutações específicas ocorrem e mantêm o fenótipo alterado das células de um tumor, enquanto a hipótese da aneuploidia estabelece que a aneuploidia é necessária e suficiente para a iniciação e progressão da transformação maligna. A aneuploidia é considerada um marcador do câncer e esta desempenha um importante papel tanto na tumorigênese, quanto na progressão tumoral. Células aneuplóides podem ser derivadas de células poliplóides, que surgem espontaneamente ou são induzidas por agentes ambientais ou compostos químicos. A instabilidade genética observada em células poliplóides leva a perdas ou rearranjos cromossômicos, resultando em cariótipos variavelmente aberrantes. Devido à grande quantidade de evidências indicando que um balanço cromossômico correto é crucial para o desenvolvimento do câncer, as técnicas citogenéticas são ferramentas importantes tanto para a pesquisa básica, tais como pesquisas para elucidar a carcinogênese, quanto pesquisas aplicadas, como no diagnóstico, prognóstico e escolha do tratamento. A combinação da citogenética clássica, citogenética molecular e genética molecular é essencial e pode gerar uma grande quantidade de dados, aumentando o nosso conhecimento da biologia do câncer, melhorando assim o tratamento desta doença.
Descritores: Cromossomos
Citogenética
Instabilidade Cromossômica
Neoplasias
Responsável: BR396.1 - Biblioteca Central


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Id: lil-725905
Autor: D'Ottavio, Guillermo E; Wulfson, Adolfo M; Rojman, Jose A.
Título: Carcinogenesis Colorrectal. Nuevas perspectivas e implicancias clínicas para su detección / Colorectal Carcinogenesis. New perspectives and clinical implications for its detection
Fonte: Rev. med. Rosario;80(2):63-74, mayo-ago. 2014. ilus.
Idioma: es.
Resumo: El cáncer colorrectal (CCR) es una de las principales causas de morbilidad y mortalidad a nivel mundial. Clásicamente se considera a los adenomas como las lesiones precursoras del CCR y se estipula un tiempo de 10 a 15 años para completar la secuencia adenoma-carcinoma. El CCR evoluciona a través de la acumulación progresiva de alteraciones genéticas y epigenéticas, las que conducen a la transformación de la mucosa colónica normal en cáncer invasivo. La identificación de diferentes vías moleculares de carcinogénesis colorrectal ha demostrado la naturaleza heterogénea del cáncer colónico. De reciente descripción, las lesiones aserradas muestran cambios moleculares y patológicos distintos a los adenomas tradicionales, estimándose que presentan un tiempo más acelerado de evolución hacia la malignidad. El objetivo de esta revisión es actualizar conocimientos sobre la génesis tumoral y sus bases biomoleculares a fin de posibilitar su aplicación a etapas clínicas concretas como la prevención y el tratamiento

Colorectal cancer (CRC) is one of the main causes of morbidity and mortality worldwide. Adenomas are classically regarded as precursor lesions of CRC and between 10 and 15 years is thought to elapse to complete the adenoma-carcinoma sequence. CRC evolves through the progressive accumulation of genetic and epigenetic alterations that lead to invasive cancer through the transformation of normal colonic mucosa. The identification of different molecular pathways of colorectal carcinogenesis has demonstrated the heterogeneous nature of colon cancer. Recent description of serrated lesions shows molecular and pathological changes other than traditional adenomas with an estimated faster time of progression to malignancy. The aim of this review is to update the knowledge about tumorigenesis and its biomolecular basis for clinical application in early stages providing firm ground for prevention and treatment
Descritores: Colonoscopia
Prevenção de Doenças
Epigênese Genética/genética
Genes Neoplásicos/genética
Lesões Pré-Cancerosas/patologia
Neoplasias Colorretais/patologia
-Metilação de DNA
Determinação/prevenção & controle
Hereditariedade/genética
Instabilidade Cromossômica/genética
Instabilidade de Microssatélites
Membrana Mucosa/anormalidades
Fenótipo
Literatura de Revisão como Assunto
Limites: Humanos
Adulto
Tipo de Publ: Revisão
Responsável: AR16.1 - Biblioteca


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Texto completo SciELO Brasil
Souto, Francisco José Dutra
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Id: lil-703643
Autor: Leite, Samantha Therezinha Almeida Pereira; Silva, Marilene Borges da; Pepato, Marco Andrey; Souto, Francisco Jose Dutra; Santos, Raquel Alves dos; Bassi-Branco, Carmen Lucia.
Título: Increased frequency of micronuclei in the lymphocytes of patients chronically infected with hepatitis B or hepatitis C virus
Fonte: Mem. Inst. Oswaldo Cruz;109(1):15-20, 02/2014. tab.
Idioma: en.
Projeto: FAPEMAT.
Resumo: In this study, we analysed the frequency of micronuclei (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) and evaluated mutagen-induced sensitivity in the lymphocytes of patients chronically infected with hepatitis B virus (HBV) or hepatitis C virus (HCV). In total, 49 patients with chronic viral hepatitis (28 HBV-infected and 21 HCV-infected patients) and 33 healthy, non-infected blood donor controls were investigated. The frequencies (‰) of MN, NPBs and NBUDs in the controls were 4.41 ± 2.15, 1.15 ± 0.97 and 2.98 ± 1.31, respectively. The frequencies of MN and NPBs were significantly increased (p < 0.0001) in the patient group (7.01 ± 3.23 and 2.76 ± 2.08, respectively) compared with the control group. When considered separately, the HBV-infected patients (7.18 ± 3.57) and HCV-infected patients (3.27 ± 2.40) each had greater numbers of MN than did the controls (p < 0.0001). The HCV-infected patients displayed high numbers of NPBs (2.09 ± 1.33) and NBUDs (4.38 ± 3.28), but only the HBV-infected patients exhibited a significant difference (NPBs = 3.27 ± 2.40, p < 0.0001 and NBUDs = 4.71 ± 2.79, p = 0.03) in comparison with the controls. Similar results were obtained for males, but not for females, when all patients or the HBV-infected group was compared with the controls. The lymphocytes of the infected patients did not exhibit sensitivity to mutagen in comparison with the lymphocytes of the controls (p = 0.06). These results showed that the lymphocytes of patients who were chronically infected with HBV or HCV presented greater chromosomal instability.
Descritores: Núcleo Celular/virologia
Hepatite B Crônica/virologia
Hepatite C Crônica/virologia
Linfócitos/virologia
Micronúcleos com Defeito Cromossômico/estatística & dados numéricos
-Fatores Etários
Análise de Variância
Distribuição de Qui-Quadrado
Instabilidade Cromossômica
Núcleo Celular/ultraestrutura
Dano ao DNA
Linfócitos/ultraestrutura
Testes para Micronúcleos
Fatores Sexuais
Limites: Adulto
Feminino
Humanos
Masculino
Pessoa de Meia-Idade
Adulto Jovem
Responsável: BR1.1 - BIREME


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Id: lil-677206
Autor: Castillo, Bárbara del; Navarrete, Carmen Luz.
Título: Síndrome de Nijmegen: una enfermedad genética a considerar en un paciente con microcefalia, retardo mental y lesiones de la piel / Nijmegen breakage syndrome
Fonte: Rev. Soc. Psiquiatr. Neurol. Infanc. Adolesc;22(1):83-86, abr. 2011.
Idioma: es.
Resumo: Se presenta el caso de un paciente masculino que a los 6 años de edad es derivado a Neurología Infantil para su estudio por presentar microcefalia y retardo mental. Tras ser evaluado por Inmunología y Genética se realiza en el Laboratorio de citogenética humana, programa de genética ICBM, Facultad de Medicina Universidad de Chile, PCR para deleción 657 del5 que confirma el diagnóstico de Nijmegen dando como resultado deleción nucleótido 5, mutación 657 del5, característico del Síndrome de Nijmegen. Actualmente el niño tiene 13 años y es tratado en el Servicio de Oncología infantil por el desarrollo de linfoma difuso de células grandes B, patología frecuente en este sindrome.

A case of a male patient at 6 years old was referred to child neurology for study due to microcephaly and mental retardation. After being evaluated for Immunology and Genetics Laboratory is performed in human cytogenetics, genetic program ICBM, Faculty of Medicine University of Chile, PCR for deletion 657 of the 5 that confirms the diagnosis of Nijmegen nucleotide deletion resulting in 5, 657 mutation del 5 Characteristic of the syndrome of Nijmegen. Currently the child is 13 and is treated at the Children's Oncology Service in the development of lymphoma diffuse large B cell, common pathology in this syndrome.
Descritores: Deficiência Intelectual
Microcefalia
Síndrome de Quebra de Nijmegen/diagnóstico
-Instabilidade Cromossômica
Deficiência de IgA
Mutação
Síndrome de Quebra de Nijmegen/complicações
Síndrome de Quebra de Nijmegen/genética
Síndrome de Quebra de Nijmegen/imunologia
Vitiligo/etiologia
Limites: Humanos
Masculino
Adolescente
Tipo de Publ: Relatos de Casos
Responsável: CL1.1 - Biblioteca Central


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Texto completo SciELO Costa Rica
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Id: lil-637628
Autor: Imery-Buiza, José.
Título: Inestabilidad cariológica durante la formación de células madres del polen en Aloe vera (Aloaceae)
Fonte: Rev. biol. trop;55(3/4):805-813, Sep.-Dec. 2007. ilus, tab.
Idioma: es.
Resumo: Con el objetivo de esclarecer la posible existencia de anomalías citogenéticas que aminoren la fertilidad del polen de Aloe vera, se analizó la etapa de proliferación celular que lleva a la formación de células madres del polen (CMPs). Se recolectaron botones florales (BF) en 25 plantas de una población ubicada a 10°34'15'' N, 64°12'08'' W, los cuales fueron fijados en Carnoy I por 24 h y almacenados en etanol (70 % v/v). Las observaciones se realizaron en preparaciones temporales obtenidas por la tinción del contenido de las anteras suspendidas en orceína acética (1.5 % p/v) por 5 minutos. De las 9 411 células analizadas, 17 % mostraron 1-8 puentes entre cromátidas hermanas, 13 % 1-7 micronúcleos de 0.9-4.8 µm, 8.1 % estaban unidas por puentes y 0.1 % no contenían cromatina. El resto de las células (61.8 %) presentó configuraciones aparentemente normales y sin variaciones morfométricas. La proliferación irregular de una fracción de CMPs (39.2 %) sugiere que las condiciones ambientales de la zona árida donde se realizaron los muestreos inducen inestabilidad cromosómica y cambios fisiológicos que afectan el normal desarrollo de la mitosis premeiótica, generando pérdida o adición de fragmentos, asociados a deficiencias y duplicaciones génicas.
Descritores: Aloe/citologia
Instabilidade Cromossômica/genética
Cromossomos de Plantas/genética
Mitose/genética
Pólen/citologia
Células-Tronco/citologia
-Aloe/genética
Pólen/genética
Venezuela
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: CR1.1 - BINASSS - Biblioteca Nacional de Salud y Seguridad Social


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Id: lil-616867
Autor: Herrera, Juan Carlos; Isaza, Luis Fernando; Ramírez, José Luis; Vásquez, Gonzalo; Muñetón, Carlos Mario.
Título: Detección de aneuploidías del cromosoma 17 y deleción del gen TP53 en una amplia variedad de tumores sólidos mediantehibridación in situ fluorescente bicolor / Detection of chromosome 17 aneuplody and TP53 gene deletion in a broad variety of solid tumors by dual-color fluorescence in situ hybridization (FISH)
Fonte: Biomédica (Bogotá);30(3):390-400, sept. 2010. tab, ilus.
Idioma: es.
Resumo: Introducción. El TP53 es un gen supresor de tumores localizado en la región cromosómica 17p13.1; controla el ciclo celular y se encuentra alterado en cerca de 50% de todas las neoplasias.Objetivos. Determinar las aneuploidías del cromosoma 17 y la deleción en el locus 17p13.1 del gen TP53, en diversos tumores sólidos primarios utilizando la técnica FISH-bicolor. Materiales y métodos. Se analizaron 38 muestras de diversos tipos de tumores sólidos primarios. Todas las muestras se disociaron mecánica y enzimáticamente con colagenasa al 0,2%, antes de la obtención de los núcleos interfásicos. La técnica de FISH-bicolor se realizó en núcleos interfásicos, mediante sondas marcadas directamente con fluorocromos para el centrómero del cromosoma 17 (CEP 17; señal verde; VYSIS) y para el locus específico del gen TP53 (LSI 17p13.1; señal naranja; VYSIS). Resultados. Se encontró que 63% (24/38) de las muestras tenían aneuploidías del cromosoma 17. La monosomía fue la aneuploidía más frecuente (75%; 18/24), seguida de la trisomía (17%; 4/24); la nulisomía y la tetrasomía fueron menos frecuentes. El 89,5% (34/38) de los casos presentaron deleción del gen TP53. Sólo cuatro casos fueron normales para el número de copias del cromosoma 17 y del gen TP53. El estudio histopatológico mostró que la mayoría de las muestras eran tumores malignos. Conclusiones. La aneuploidía del cromosoma 17 y la deleción en el locus 17p13.1 del gen TP53 son alteraciones muy frecuentes en los tumores sólidos. La técnica FISH-bicolor permite detectar simultáneamente alteraciones cromosómicas numéricas y estructurales en núcleos interfásicos.

Introduction. TP53 is a tumor suppressor gene located on chromosome 17p13.1. This gene is essential for the control of cell cycle and has been found altered in about 50% of all tumor types.Objective. The presence of aneuploidy of chromosome 17 and TP53 gene deletion at 17p13.1 locus was determined in primary solid tumors using the dual-color FISH (fluorescence in situ hybridization).Materials and methods. Thirty-eight samples consisted of several types of primary solid tumors. All samples were mechanically and enzymatically disaggregated with 0.2% collagenase prior to obtaining interphase nuclei. The dual-color FISH was performed using direct fluorescent labeling probes for the chromosome 17 centromere (green signal) and for the TP53 gene locus-specific (orange signal). Results. Characteristic aneuploidy on chromosome 17 was found in 63% (24/38) of the samples. Monosomy occurred most frequently (75%, 18/24), followed by trisomy (17%, 4/24); nullisomy and tetrasomy were less frequent. TP53 gene deletion was found in 89.5% (34/38) of cases. Only four tumors were normal for copy number of chromosome 17 and TP53 gene. The histopathologic study showed that most of the samples were malignant tumors. Conclusions. Aneuploidy of chromosome 17 and deletion at 17p13.1 locus of TP53 gene were genetic alterations found to be very frequent in solid tumors. The dual-color FISH was able to detect both numerical and structural chromosomal abnormalities in interphase nuclei.
Descritores: Aneuploidia
Deleção Cromossômica
Hibridização in Situ Fluorescente
Neoplasias
-Instabilidade Cromossômica
Heterogeneidade Genética
Limites: Humanos
Responsável: CO42.1 - Biblioteca Nacional de Salud José Celestino Mutis


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Id: lil-582218
Autor: Nascimento e Pontes, Merielen Garcia.
Título: Ganhos e perdas genômicas em momentos sucessivos do carcinoma urotelial de bexiga humana / Chromosomal imbalances in sucessive moments of human bladder urothelial carcinoma.
Fonte: Botucatu; s.n; 2010. [72] p. ilus, tab.
Idioma: pt.
Tese: Apresentada a Universidade Estadual Paulista. Faculdade de Medicina de Botucatu para obtenção do grau de Doutor.
Descritores: Instabilidade Cromossômica
Expressão Gênica
Neoplasias da Bexiga Urinária/genética
Limites: Humanos
Masculino
Feminino
Responsável: BR33.1 - Divisão Técnica de Biblioteca e Documentação
BR33.1


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Id: lil-545864
Autor: Escribano R., Gloria; Castillo T., Silvia; Daher N., Vera; Salazar C., Samuel; Tobella P., Lorena.
Título: Principales factores que producen fragilidad cromosómica transitoria en los pacientes referidos para estudio citogenético / Main factors that produce transitory chromosomic fragility in the patients referred for cytogenetic study
Fonte: Rev. Hosp. Clin. Univ. Chile;20(1):20-27, 2009. tab.
Idioma: es.
Resumo: The fragile sites are specific loci that show fractures during karyotyping perform under specific laboratory conditions. Are present in normal individuals and are classified by their population frequency. These sites have been associated with an increase in chromosome fragility, fractures and other chromosomal abnormalities. In recent years, the fragile sites have taken great importance because they represent regions in the genome that are particularly sensitive to replicative stress and are frequently rearrenged in tumor cells. Multiple risk factors endogenous and exogenous have been involved in the increase in chromosome fragility, including microorganisms, drugs, illegal drugs and toxins. The fragile sites have provided insight into understanding of the effects of replicative stress on DNA damage and genomic instability in cancer cells. In this work we aim to summarize the limited information available about the topic, and the clinical significance of fragile sites in vivo in the laboratory.
Descritores: Fragilidade Cromossômica
Análise Citogenética
-Instabilidade Cromossômica
Aberrações Cromossômicas
Síndrome do Cromossomo X Frágil
Limites: Humanos
Masculino
Feminino
Tipo de Publ: Revisão
Responsável: CL36.1 - Biblioteca Hospital Clínico



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