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Análise citogenética comparada em mastocitomas: enfoque especial na raça Boxer; Compared cytogenetic analysis in mast cell tumors: a special focus on Boxer breed

Lima, Mirela Aline Real de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 14/04/2009 PT
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Atualmente muitas são as técnicas utilizadas na área de citogenética para que os desequilíbrios genéticos potencialmente hereditários sejam identificados ou evitados. Algumas das técnicas são utilizadas apenas para o diagnóstico de enfermidades em humanos, mas seria importante que fossem aplicadas também aos animais domésticos, com a finalidade de se associar uma causa genética ao aparecimento de algumas doenças, como por exemplo, os mastocitomas. Os mastocitomas são formações cutâneas neoplásicas originadas de mastócitos e se apresentam com frequência em cães. Algumas raças apresentam maior susceptibilidade ao aparecimento de mastocitoma, e o Boxer tem a maior incidência nesta espécie. Este trabalho objetivou avaliar comparativamente o cariótipo de cães da raça Boxer e buscar uma possível correlação com o desenvolvimento de mastocitoma. Foram utilizadas técnicas citogenéticas de bandamentos C, G e Ron além de análises em coloração convencional (Giemsa). Para tais análises utilizaram-se células cultivadas de linfócitos periféricos e de mastocitomas de Boxer. O material foi analisado e fotografado em microscópio de imersão da marca Zeiss®, em objetiva de 100x, com filtro verde, equipado com software de análise citogenética Ikaros®. Foram consideradas alterações numéricas e estruturais. Foram analisadas 828 metáfases mitóticas provenientes de linfócitos periféricos e células de mastocitomas. A análise das metáfases provenientes de cultura de células dos linfócitos periféricos não apresentou alterações estruturais e a análise numérica mostrou somente uma metáfase com 2n=77...

Citogenética do gênero Leucaena Benth; Cytogenetics of the genus Leucaena Benth

Schifino-Wittmann, Maria Teresa
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Artigo de Revista Científica Formato: application/pdf
POR
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Neste trabalho, são revistos e discutidos os resultados mais relevantes dos estudos citogenéticos em Leucaena realizados pelo grupo do Departamento de Plantas Forrageiras e Agrometeorologia da Universidade Federal do Rio Grande do Sul, que envolvem híbridos selecionados dentro de programas de melhoramento, e as espécies selvagens e cultivadas do gênero. Estes resultados revelaram variabilidade intra e interespecífica para o número cromossômico, mostrando a ocorrência de multivalentes mesmo nas espécies consideradas diplóides (o que apóia a origem paleopoliplóide de muitas espécies) e constituem uma importante contribuição para a citogenética das espécies de Leucaena, com repercussões na taxonomia e no melhor entendimento da complexa evolução do gênero. Os resultados indicam que deve haver um acompanhamento citogenético em programas de melhoramento genético destas espécies.; The cytogenetics group of the Departamento de Plantas Forrageiras e Agrometeorologia, Universidade Federal do Rio Grande do Sul, Brazil determined the chromosome numbers of all species of Leucaena. Cytogenetic results of some selected hybrids and wild and cultivated species of Leucaena are reviewed and discussed. The results showed an intra and interespecific chromosome number variability and the occurrence of multivalents even in the presumed diploid species (what supports a paleopolyploid origin for these species). This is a very important contribution and may reflect on the taxonomy and on the understanding of the complex evolution of Leucaena. These results suggest that cytogenetic studies should be part of all Leucaena breeding programs.

Integrating cytogenetics and genomics in comparative evolutionary studies of cichlid fish

Mazzuchelli, Juliana; Kocher, Thomas David; Yang, Fengtang; Martins, Cesar
Fonte: Biomed Central Ltd. Publicador: Biomed Central Ltd.
Tipo: Artigo de Revista Científica Formato: 14
ENG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Background: The availability of a large number of recently sequenced vertebrate genomes opens new avenues to integrate cytogenetics and genomics in comparative and evolutionary studies. Cytogenetic mapping can offer alternative means to identify conserved synteny shared by distinct genomes and also to define genome regions that are still not fine characterized even after wide-ranging nucleotide sequence efforts. An efficient way to perform comparative cytogenetic mapping is based on BAC clones mapping by fluorescence in situ hybridization. In this report, to address the knowledge gap on the genome evolution in cichlid fishes, BAC clones of an Oreochromis niloticus library covering the linkage groups (LG) 1, 3, 5, and 7 were mapped onto the chromosomes of 9 African cichlid species. The cytogenetic mapping data were also integrated with BAC-end sequences information of O. niloticus and comparatively analyzed against the genome of other fish species and vertebrates.Results: The location of BACs from LG1, 3, 5, and 7 revealed a strong chromosomal conservation among the analyzed cichlid species genomes...

Análise citogenética clássica e molecular em Chelonoidis carbonaria e Phrynops geoffroanus (Testudines)

Zago, Carlos Eduardo Saranz
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Tese de Doutorado Formato: 100 f. : il. color.
POR
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27.06%
Pós-graduação em Genética - IBILCE; Os répteis sofreram redução do número de espécies desde a época em que dominavam a Terra até os dias atuais. Os quelônios são poucos estudados, principalmente quanto à sua caracterização citogenética. O presente trabalho objetivou estudar, por meio das técnicas de citogenética clássica e molecular, os cromossomos de Chelonoidis carbonaria, espécie terrestre e Phrynops geoffroanus, espécie ameaçada de extinção que vive nas margens dos rios no continente Sul Americano. As amostras de sangue foram coletadas de animais do criatório, “Reginaldo Uvo Leone”, em Tabapuã-SP. Todos os procedimentos foram aprovados pelo Comitê de Ética Animal (nº 50/07-CEEA – Botucatu – SP) e pelo IBAMA/RAN (nº 14729-1). Para obter as metáfases, o sangue foi inoculado em meio de cultura de linfócitos que foram estimulados a se dividirem pela adição de fito-hemaglutina. Após esse procedimento, a colchicina foi adicionada para inibir a formação das fibras do fuso, mantendo as células em metáfase. Foram avaliados machos e fêmeas de Chelonoidis carbonaria, que apresentaram número de cromossomos igual a 2n = 52, e de Phrynops geoffroanus, descrito pela primeira vez, cujas fêmeas apresentaram 2n = 58 e os machos com 2n = 57 cromossomos. Pela metodologia de bandamento G...

Human molecular cytogenetics: from cells to nucleotides

Riegel,Mariluce
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
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37.33%
The field of cytogenetics has focused on studying the number, structure, function and origin of chromosomal abnormalities and the evolution of chromosomes. The development of fluorescent molecules that either directly or via an intermediate molecule bind to DNA has led to the development of fluorescent in situ hybridization (FISH), a technology linking cytogenetics to molecular genetics. This technique has a wide range of applications that increased the dimension of chromosome analysis. The field of cytogenetics is particularly important for medical diagnostics and research as well as for gene ordering and mapping. Furthermore, the increased application of molecular biology techniques, such as array-based technologies, has led to improved resolution, extending the recognized range of microdeletion/microduplication syndromes and genomic disorders. In adopting these newly expanded methods, cytogeneticists have used a range of technologies to study the association between visible chromosome rearrangements and defects at the single nucleotide level. Overall, molecular cytogenetic techniques offer a remarkable number of potential applications, ranging from physical mapping to clinical and evolutionary studies, making a powerful and informative complement to other molecular and genomic approaches. This manuscript does not present a detailed history of the development of molecular cytogenetics; however...

Impact of cytogenetics on outcome of matched unrelated donor hematopoietic stem cell transplantation for acute myeloid leukemia in first or second complete remission

Tallman, Martin S.; Dewald, Gordon W.; Gandham, Sharavi; Logan, Brent R.; Keating, Armand; Lazarus, Hillard M.; Litzow, Mark R.; Mehta, Jayesh; Pedersen, Tanya; Pérez, Waleska S.; Rowe, Jacob M.; Wetzler, Meir; Weisdorf, Daniel J.
Fonte: American Society of Hematology Publicador: American Society of Hematology
Tipo: Artigo de Revista Científica
Publicado em 01/07/2007 EN
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We compared the treatment-related mortality, relapse rate, disease-free survival (DFS), and overall survival (OS) by cytogenetic risk group of 261 patients with acute myeloid leukemia in first complete remission (CR1) and 299 patients in CR2 in undergoing matched unrelated donor hematopoietic stem cell transplantation (HSCT). For patients in first CR, the DFS and OS at 5 years were similar for the favorable, intermediate, and unfavorable risk groups at 29% (95% confidence interval [CI], 8%-56%) and 30% (22%-38%); 27% (19%-39%) and 29% (8%-56%); and 30% (95% CI, 22%-38%) and 30% (95% CI, 20%-41%), respectively. For patients in second CR, the DFS and OS at 5 years were 42% (95% CI, 33%-52%) and 35% (95% CI, 28%-43%); 38% (95% CI, 23%-54%) and 45% (95% CI, 35%-55%); and 37% (95% CI, 30%-45%) and 36% (95% CI, 21%-53%), respectively. Cytogenetics had little influence on the overall outcome for patients in first CR. In second CR, outcome was modestly, but not significantly, better for patients with favorable cytogenetics. The graft-versus-leukemia effect appeared effective, even in patients with unfavorable cytogenetics. However, treatment-related mortality was high. Matched unrelated donor HSCT should be considered for all patients with unfavorable cytogenetics who lack a suitable HLA-matched sibling donor.

Impact of cytogenetics on the outcome of adult acute lymphoblastic leukemia: results of Southwest Oncology Group 9400 study

Pullarkat, Vinod; Slovak, Marilyn L.; Kopecky, Kenneth J.; Forman, Stephen J.; Appelbaum, Frederick R.
Fonte: American Society of Hematology Publicador: American Society of Hematology
Tipo: Artigo de Revista Científica
Publicado em 01/03/2008 EN
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We examined the prognostic impact of cytogenetics on the outcome of 200 acute lymphoblastic leukemia (ALL) patients 15 to 65 years of age enrolled in Southwest Oncology Group (SWOG)–9400 study. Evaluable cytogenetics or fluorescence in situ hybridization studies were available in 140 (70%) patients. Four karyotype categories (normal [n = 31, 22%], t(9;22)/BCR/ABL1 [n = 36, 26%], other unfavorable [−7, +8, or 11q23 rearrangement, n = 19, 13%], and miscellaneous [n = 54, 39%]) and the biologically and clinically relevant ALL ploidy subgroups were prospectively defined. Overall survival (OS) decreased significantly with increasing age (P = .009) and varied with karyotype category (P < .001). OS was worst for t(9;22)/BCR/ABL1 followed by other unfavorable karyotypes, with hazard ratios (HR) of 3.45 (95% confidence interval [CI], 1.88-6.31) and 2.14 (95% CI, 1.04-4.04), respectively, compared with normal diploid group. OS of the miscellaneous group was similar to that of the normal diploid group (HR = 0.82; 95% CI, 0.44-1.53). Relapse-free survival (RFS) was not significantly associated with age (P = .30) but was heterogeneous among karyotype categories (P < .001) primarily because of poor RFS in t(9;22)/BCR/ABL1 (HR = 3.49; 95% CI...

Impact of Cytogenetics on Outcome of De novo and Therapy-related AML and MDS after Allogeneic Transplantation

Armand, Philippe; Kim, Haesook T.; DeAngelo, Daniel J.; Ho, Vincent T.; Cutler, Corey S.; Stone, Richard M.; Ritz, Jerome; Alyea, Edwin P.; Antin, Joseph H.; Soiffer, Robert J.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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27.33%
Cytogenetics has an important impact on the prognosis of patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) for AML or MDS. However, it is unclear whether currently accepted cytogenetic risk groups, which were established for patients treated mostly with standard therapy, are optimally discriminating for patients undergoing HSCT. Also, the impact of cytogenetics in the growing population of patients with therapy-related disease has not been completely elucidated. In this study, we retrospectively analyzed data on 556 patients with AML or MDS transplanted at our institution. We examined, in multivariate analyses, the contribution of cytogenetics to survival, relapse, and non-relapse mortality (NRM) for the 476 patients with de novo disease. We used these results to establish an optimal cytogenetic grouping scheme. We then applied this grouping scheme to the 80 patients with therapy-related disease. Our proposed three-group cytogenetic classification outperformed the established grouping schemes for both de novo and therapy-related disease. When classified by this new scheme, cytogenetics was the strongest prognostic factor for overall survival in our cohort, through its impact on the risk of relapse (and not on NRM). After accounting for cytogenetics...

Multicenter Validation Study of a Transplantation-Specific Cytogenetics Grouping Scheme for Patients with Myelodysplastic Syndromes

Armand, Philippe; Deeg, H. Joachim; Kim, Haesook T.; Lee, Hun; Armistead, Paul; de Lima, Marcos; Gupta, Vikas; Soiffer, Robert J.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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27.29%
Cytogenetics are an important prognostic factor for patients with MDS. However, existing cytogenetics grouping schemes are based on patients treated with supportive care, and may not be optimal for patients undergoing allogeneic stem cell transplantation (SCT). We previously proposed an SCT-specific cytogenetics grouping scheme for patients with MDS and AML arising from MDS, based on an analysis of patients transplanted at Dana-Farber Cancer Institute/Brigham and Women’s Hospital. Under this scheme, abnormalities of chromosome 7 and complex karyotype are considered adverse-risk, while all others are considered standard-risk. In the present retrospective study, we validated this scheme on an independent multicenter cohort of 546 patients. Adverse cytogenetics was the strongest prognostic factor for outcome in this cohort. Four-year relapse-free and overall survival were 42% and 46%, respectively, in the standard risk group, versus 21% and 23% in the adverse group (p<0.0001 for both comparisons). This grouping scheme retained its prognostic significance irrespective of patient age, disease type, prior leukemogenic therapy, and conditioning intensity. Therapy-related disease was not associated with increased mortality in this cohort...

FLT3 and NPM1 mutations in Chinese patients with acute myeloid leukemia and normal cytogenetics

Wang, Lei; Xu, Wei-lai; Meng, Hai-tao; Qian, Wen-bin; Mai, Wen-yuan; Tong, Hong-yan; Mao, Li-ping; Tong, Yin; Qian, Jie-jing; Lou, Yin-jun; Chen, Zhi-mei; Wang, Yun-gui; Jin, Jie
Fonte: Zhejiang University Press Publicador: Zhejiang University Press
Tipo: Artigo de Revista Científica
Publicado em /10/2010 EN
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Mutations of fms-like tyrosine kinase 3 (FLT3) and nucleophosmin (NPM1) exon 12 genes are the most common abnormalities in adult acute myeloid leukemia (AML) with normal cytogenetics. To assess the prognostic impact of the two gene mutations in Chinese AML patients, we used multiplex polymerase chain reaction (PCR) and capillary electrophoresis to screen 76 AML patients with normal cytogenetics for mutations in FLT3 internal tandem duplication (FLT3/ITD) and exon 12 of the NPM1 gene. FLT3/ITD mutation was detected in 15 (19.7%) of 76 subjects, and NPM1 mutation in 20 (26.3%) subjects. Seven (9.2%) cases were positive for both FLT3/ITD and NPM1 mutations. Significantly more FLT3/ITD aberration was detected in subjects with French-American-British (FAB) M1 (42.8%). NPM1 mutation was frequently detected in subjects with M5 (47.1%) and infrequently in subjects with M2 (11.1%). FLT3 and NPM1 mutations were significantly associated with a higher white blood cell count in peripheral blood and a lower CD34 antigen expression, but not age, sex, or platelet count. Statistical analysis revealed that the FLT3/ITD-positive group had a lower complete remission (CR) rate (53.3% vs. 83.6%). Survival analysis showed that the FLT3/ITD-positive/NPM1 mutation-negative group had worse overall survival (OS) and relapse-free survival (RFS). The FLT3/ITD-positive/NPM1 mutation-positive group showed a trend towards favorable survival compared with the FLT3/ITD-positive/NPM1 mutation-negative group (P=0.069). Our results indicate that the FLT3/ITD mutation might be a prognostic factor for an unfavorable outcome in Chinese AML subjects with normal cytogenetics...

Contributions of Cytogenetics and Molecular Cytogenetics to the Diagnosis of Adipocytic Tumors

Nishio, Jun
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
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27.06%
Over the last 20 years, a number of tumor-specific chromosomal translocations and associated fusion genes have been identified for mesenchymal neoplasms including adipocytic tumors. The addition of molecular cytogenetic techniques, especially fluorescence in situ hybridization (FISH), has further enhanced the sensitivity and accuracy of detecting nonrandom chromosomal translocations and/or other rearrangements in adipocytic tumors. Indeed, most resent molecular cytogenetic analysis has demonstrated a translocation t(11;16)(q13;p13) that produces a C11orf95-MKL2 fusion gene in chondroid lipoma. Additionally, it is well recognized that supernumerary ring and/or giant rod chromosomes are characteristic for atypical lipomatous tumor/well-differentiated liposarcoma and dedifferentiated liposarcoma, and amplification of 12q13–15 involving the MDM2, CDK4, and CPM genes is shown by FISH in these tumors. Moreover, myxoid/round cell liposarcoma is characterized by a translocation t(12;16)(q13;p11) that fuses the DDIT3 and FUS genes. This paper provides an overview of the role of conventional cytogenetics and molecular cytogenetics in the diagnosis of adipocytic tumors.

Serial assessment of suspected myelodysplastic syndromes: significance of flow cytometric findings validated by cytomorphology, cytogenetics, and molecular genetics

Kern, Wolfgang; Haferlach, Claudia; Schnittger, Susanne; Alpermann, Tamara; Haferlach, Torsten
Fonte: Ferrata Storti Foundation Publicador: Ferrata Storti Foundation
Tipo: Artigo de Revista Científica
Publicado em /02/2013 EN
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27.16%
The significance of flow cytometry indicating myelodysplasia without proof of myelodysplasia by cytomorphology remains to be clarified. We evaluated follow-up analyses in 142 patients analyzed in parallel by flow cytometry, cytomorphology and cytogenetics for suspected myelodysplasia without proof of myelodysplasia by cytomorphology. At initial assessment, flow cytometry indicated myelodysplasia in 64 of 142 (45.1%) patients. In 9 of 142 (6.3%) patients, cytogenetics revealed aberrant karyotypes at first evaluation that were found in 5 of 64 (7.8%) patients rated with myelodysplasia by flow cytometry. The remaining 133 patients without proof of myelodysplasia by cytomorphology and with normal karyotype underwent follow-up analyses that confirmed myelodysplasia by cytomorphology, cytogenetics or molecular genetics in 47 (35.3%) after a median interval of nine months (range 1-53 months). As far as initial flow cytometry results are concerned, this applied to 30 of 59 (50.1%) with myelodysplasia, 10 of 42 (23.8%) with “possible myelodysplasia” (minor antigen aberrancies only) and 7 of 32 (21.9%) without myelodysplasia (P=0.004). Notably, in these latter 7 patients, flow cytometry results changed at follow up to “possible myelodysplasia” (n=4) and “myelodysplasia” (n=2). These data argue in favor of including flow cytometry along with cytomorphology...

Treatment outcomes in patients with relapsed and refractory multiple myeloma and high-risk cytogenetics receiving single-agent carfilzomib in the PX-171-003-A1 study

Jakubowiak, A J; Siegel, D S; Martin, T; Wang, M; Vij, R; Lonial, S; Trudel, S; Kukreti, V; Bahlis, N; Alsina, M; Chanan-Khan, A; Buadi, F; Reu, F J; Somlo, G; Zonder, J; Song, K; Stewart, A K; Stadtmauer, E; Harrison, B L; Wong, A F; Orlowski, R Z; Jagan
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
EN
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27.06%
Several cytogenetic abnormalities are associated with poor outcomes in multiple myeloma (MM). We prospectively analyzed the impact of cytogenetic abnormalities on outcomes during the phase 2 PX-171-003-A1 study of single-agent carfilzomib for relapsed and refractory MM. In the response-evaluable population (257/266), fluorescence in situ hybridization (FISH)/conventional cytogenetic profiles were available for 229 patients; 62 (27.1%) had high-risk cytogenetics—del 17p13, t(4;14) or t(14;16) by interphase FISH or deletion 13 or hypodiploidy by metaphase cytogenetics—and 167 (72.9%) had standard-risk profiles. Generally, baseline characteristics were similar between the subgroups, but International Staging System stage III disease was more common in high- vs standard-risk patients (41.9% vs 27.5%) as was Eastern Cooperative Oncology Group performance status 1/2 (85.5% vs 68.3%). Overall response was comparable between the subgroups (25.8% vs 24.6%, respectively; P=0.85), while time-to-event end points showed a trend of shorter duration in high-risk patients, including median duration of response (5.6 months (95% confidence interval (CI) 3.7–7.8) vs 8.3 months (95% CI 5.6–12.3)) and overall survival (9.3 (95% CI 6.5–13.0) vs 19.0 months (95% CI 15.4–NE); P=0.0003). Taken together...

Human molecular cytogenetics: From cells to nucleotides

Riegel, Mariluce
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.29%
The field of cytogenetics has focused on studying the number, structure, function and origin of chromosomal abnormalities and the evolution of chromosomes. The development of fluorescent molecules that either directly or via an intermediate molecule bind to DNA has led to the development of fluorescent in situ hybridization (FISH), a technology linking cytogenetics to molecular genetics. This technique has a wide range of applications that increased the dimension of chromosome analysis. The field of cytogenetics is particularly important for medical diagnostics and research as well as for gene ordering and mapping. Furthermore, the increased application of molecular biology techniques, such as array-based technologies, has led to improved resolution, extending the recognized range of microdeletion/microduplication syndromes and genomic disorders. In adopting these newly expanded methods, cytogeneticists have used a range of technologies to study the association between visible chromosome rearrangements and defects at the single nucleotide level. Overall, molecular cytogenetic techniques offer a remarkable number of potential applications, ranging from physical mapping to clinical and evolutionary studies, making a powerful and informative complement to other molecular and genomic approaches. This manuscript does not present a detailed history of the development of molecular cytogenetics; however...

Cancer Cytogenetics: Methodology Revisited

Wan, Thomas S. K.
Fonte: The Korean Society for Laboratory Medicine Publicador: The Korean Society for Laboratory Medicine
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.16%
The Philadelphia chromosome was the first genetic abnormality discovered in cancer (in 1960), and it was found to be consistently associated with CML. The description of the Philadelphia chromosome ushered in a new era in the field of cancer cytogenetics. Accumulating genetic data have been shown to be intimately associated with the diagnosis and prognosis of neoplasms; thus, karyotyping is now considered a mandatory investigation for all newly diagnosed leukemias. The development of FISH in the 1980s overcame many of the drawbacks of assessing the genetic alterations in cancer cells by karyotyping. Karyotyping of cancer cells remains the gold standard since it provides a global analysis of the abnormalities in the entire genome of a single cell. However, subsequent methodological advances in molecular cytogenetics based on the principle of FISH that were initiated in the early 1990s have greatly enhanced the efficiency and accuracy of karyotype analysis by marrying conventional cytogenetics with molecular technologies. In this review, the development, current utilization, and technical pitfalls of both the conventional and molecular cytogenetics approaches used for cancer diagnosis over the past five decades will be discussed.

Impact of the revised International Prognostic Scoring System, cytogenetics and monosomal karyotype on outcome after allogeneic stem cell transplantation for myelodysplastic syndromes and secondary acute myeloid leukemia evolving from myelodysplastic syndromes: a retrospective multicenter study of the European Society of Blood and Marrow Transplantation

Koenecke, Christian; Göhring, Gudrun; de Wreede, Liesbeth C.; van Biezen, Anja; Scheid, Christof; Volin, Liisa; Maertens, Johan; Finke, Jürgen; Schaap, Nicolaas; Robin, Marie; Passweg, Jakob; Cornelissen, Jan; Beelen, Dietrich; Heuser, Michael; de Witte
Fonte: Ferrata Storti Foundation Publicador: Ferrata Storti Foundation
Tipo: Artigo de Revista Científica
Publicado em /03/2015 EN
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27.06%
The aim of this study was to determine the impact of the revised 5-group International Prognostic Scoring System cytogenetic classification on outcome after allogeneic stem cell transplantation in patients with myelodysplastic syndromes or secondary acute myeloid leukemia who were reported to the European Society for Blood and Marrow Transplantation database. A total of 903 patients had sufficient cytogenetic information available at stem cell transplantation to be classified according to the 5-group classification. Poor and very poor risk according to this classification was an independent predictor of shorter relapse-free survival (hazard ratio 1.40 and 2.14), overall survival (hazard ratio 1.38 and 2.14), and significantly higher cumulative incidence of relapse (hazard ratio 1.64 and 2.76), compared to patients with very good, good or intermediate risk. When comparing the predictive performance of a series of Cox models both for relapse-free survival and for overall survival, a model with simplified 5-group cytogenetics (merging very good, good and intermediate cytogenetics) performed best. Furthermore, monosomal karyotype is an additional negative predictor for outcome within patients of the poor, but not the very poor risk group of the 5-group classification. The revised International Prognostic Scoring System cytogenetic classification allows patients with myelodysplastic syndromes to be separated into three groups with clearly different outcomes after stem cell transplantation. Poor and very poor risk cytogenetics were strong predictors of poor patient outcome. The new cytogenetic classification added value to prediction of patient outcome compared to prediction models using only traditional risk factors or the 3-group International Prognostic Scoring System cytogenetic classification.

Use of interphase cytogenetics in demonstrating specific chromosomal aberrations in solid tumors new insights in the pathogenesis of malignant melanoma and head and neck squamous cell carcinoma

Poetsch, M.; Dittberner, T.; Woenckhaus, C.; Kleist, B.
Fonte: Murcia : F. Hernández Publicador: Murcia : F. Hernández
Tipo: Artigo de Revista Científica Formato: application/pdf
ENG
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37.06%
The detection of structural and numerical chromosomal aberrations is an important part of the characterization of tumors and genetic diseases. The direct demonstration of DNA sequences in interphase nuclei and metaphases by fluorescence in situ hybridization (FISH) has been termed interphase cytogenetics. It has been proven as a powerful technique to detect specific aberrations in a wide variety of cell types, including paraffin-embedded tissue. Nowadays a standard method in leukemia and lymphoma, interphase cytogenetics contributes mainly to the diagnosis in these tumors and helps to classify soft tissue tumors. Therefore FISH is mandatory for the choice of therapy in these tumors. In contrast to the aforementioned, up to now, the value of FISH in solid tumors is mostly limited to pure research and contributes in this way to our understanding of tumor biology. But with the use of paraffin-embedded tissue and the first results obtained, it seems very likely that a direct correlation between histological classification and cytogenetic characteristics of solid tumors can be achieved in the near future. This information might not only provide insights into tumor biology, but could also contribute to a different tumor classification...

Comparison of high resolution cytogenetics, fluorescence in situ hybridisation, and DNA studies to validate the diagnosis of Prader-Willi and Angelman's syndromes.

Smith, A; Prasad, M; Deng, Z M; Robson, L; Woodage, T; Trent, R J
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1995 EN
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27.23%
Eighty seven referrals with Prader-Willi syndrome and 49 with Angelman's syndrome were studied. High resolution cytogenetics was performed on all probands. Molecular studies, performed on the proband and both parents in each case, utilised multiple probes from within and distal to the 15(q11-13) region in order to establish the presence of DNA deletion or uniparental disomy. In addition, FISH, with probes at D15S11 and GABR beta 3 from the Prader-Willi syndrome/Angelman's syndrome region, was performed on a subset of 25 of these patients. In the referral group with Prader-Willi syndrome, 62 patients had a normal karyotype and 25 were deleted on high resolution cytogenetics. Twenty nine were found to be deleted with DNA techniques. In the Angelman's syndrome group, 37 had a normal karyotype and 12 were deleted on high resolution cytogenetics while 26 were deleted on molecular studies. The diagnosis was reassessed in 35 referrals with Prader-Willi syndrome and 11 with Angelman's syndrome following a non-deleted, non-disomic result. Of individuals who were neither deleted nor disomic on DNA studies, a false positive rate of 11.4% (4/35) for Prader-Willi syndrome and 16.7% (2/12) for Angelman's syndrome was found for a cytogenetically detected deletion. The false negative rate for deletion detected on high resolution cytogenetics was 19.5% (12/62) for Prader-Willi syndrome and 35% (13/37) for Angelman's syndrome. Thus high resolution cytogenetics was shown to be unreliable for deletion detection and should not be used alone to diagnose either syndrome. There were no discrepancies with FISH in 25 cases when FISH was compared with the DNA results...

Canine Cytogenetics - From band to basepair

Breen, Matthew
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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27.23%
Humans and dogs have coexisted for thousands of years, during which time we have developed a unique bond, centered on companionship. Along the way, we have developed purebred dog breeds in a manner that has resulted unfortunately in many of them being affected by serious genetic disorders, including cancers. With serendipity and irony the unique genetic architecture of the 21st Century genome of Man's best friend may ultimately provide many of the keys to unlock some of nature's most intriguing biological puzzles. Canine cytogenetics has advanced significantly over the past 10 years, spurred on largely by the surge of interest in the dog as a biomedical model for genetic disease and the availability of advanced genomics resources. As such the role of canine cytogenetics has moved rapidly from one that served initially to define the gross genomic organization of the canine genome and provide a reliable means to determine the chromosomal location of individual genes, to one that enabled the assembled sequence of the canine genome to be anchored to the karyotype. Canine cytogenetics now presents the biomedical research community with a means to assist in our search for a greater understanding of how genome architectures altered during speciation and in our search for genes associated with cancers that affect both dogs and humans. The cytogenetics ‘toolbox’ for the dog is now loaded. This review aims to provide a summary of some of the recent advancements in canine cytogenetics.

Estudio piloto de la fusión PML/RARalfa por el método de hibridación in situ con fluorescencia (FISH) en leucemia aguda promielocítica

Legües S,María Eugenia; Franco C,Giannina; Bertin C,Pablo
Fonte: Sociedad Médica de Santiago Publicador: Sociedad Médica de Santiago
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2002 ES
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27.23%
Background: Acute promyelocytic leukemia (APL) is characterized cytogenetically by t(15;17) (q22;q21) and its molecular consequence, fusion of PML and RARalpha genes. The detection of this genetic marker confirms the diagnosis and allows monitoring of the leukemic clone during treatment, which has prognostic value. Cytogenetics fails in some cases due to the absence of metaphases in cultures or their bad morphology. Southern blot and PCR methods require trained personnel and adequate equipment. FISH method allows the identification of chromosomic rearrangements in 24 to 48 h and is simple to set up in a cytogenetics laboratory. Aim: To evaluate the FISH method to detect PML/RARalpha fusion, compared to cytogenetic analysis. Patients and methods: Fifteen bone marrow specimens from APL patients with previous cytogenetic analysis were studied, using a commercial probe to detect PML/RARalpha fusion. Results: We obtained a normal cut-off value of 9.1%. Specificity and sensibility were 100%. Six positive cytogenetic cases at diagnosis were FISH positive. Six negative cytogenetic cases, one APL at diagnosis and five normal controls were FISH negative. One case in remission, that was negative by cytogenetics, was positive near the cut-off value by FISH. Two other cases in remission...