Navegando por Palavras-chave "In situ hybridization, fluorescence"

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    Avaliação de pacientes com o espectro clínico da síndrome da deleção 22q11.2 através de hibridização in situ por fluorescência e da técnica multiplex ligation-dependent probe amplification
    (Universidade Federal de São Paulo (UNIFESP), 2010-04-28) Pacanaro, Ade Nubia Xavier [UNIFESP]; Moraes-Pinto, Maria Isabel de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Introduction: The 22q11.2 deletion is the most frequent human microdeletion syndrome. The phenotype is highly variable and characterized by conotruncal heart defects, facial dysmorphism, velophalangeal dysfunction, hypoparathyroidism, thymic hypoplasia, learning disabilities, and mental retardation. Purpose: To investigate patients with clinical phenotype of the 22q11.2 deletion syndrome considering the presence, origin and extension of the deletion. To investigate other genomic region unbalances related to the syndrome. To correlate the different segments deleted with the phenotype. Methods: We studied 70 patients with diagnostic hypothesis of 22q11.2 deletion syndrome. Cytogenetic analysis was performed using G-banding. We used FISH (fluorescence in situ hybridization) technique in order to evaluate the deletion presence and origin, and MLPA (multiplex ligation-dependent probe amplification) technique in order to identify deletions and to determine their sizes and also, to evaluate other chromosomal region unbalances. Results: The cytogenetic analysis using G-banding showed normal karyotypes in all patients, except in one that was 48,XXXX. We found 21 patients with deletion and 49 patients with normal results, using the FISH and MLPA approaches. Among the 18 deletions investigated with MLPA, 13 were 3 Mb deletion (72%), two were 1,5 Mb deletion (11%) and three were atypical deletions (17%). Two were inherited deletions. Conclusions: Among patients with the phenotype of 22q11.2 deletion syndrome, we found 30% cases of 22q11.2 deletion. The phenotype correlation with the different size deletions is not well established considering the wide phenotypic variation found either in patient with typical deletions of 3 Mb or in patients with smaller and atypical deletions. The frequency of phenotypic features did not differ significantly between deleted and not deleted patients’ groups. Considering the great phenotypic variability among patients with different deletions and the clinical characteristics overlapping with the ones present in not deleted patients, it is important molecular approaches for the diagnosis. FISH and MLPA approaches have proved successful in the investigation of 22q11.2 deletion, although only MLPA technique is able to determine the 22q11.2 deletion extension.
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    Prevalence of chimerism after non-myeloablative hematopoietic stem cell transplantation
    (Associação Paulista de Medicina - APM, 2009-09-01) Ruiz, Azulamara da Silva [UNIFESP]; Chauffaille, Maria de Lourdes Lopes Ferrari [UNIFESP]; Alves, Solivanda Trindade; Oliveira, José Salvador Rodrigues de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Hospital Santa Marcelina Division of Hematology and Transfusion Medicine
    CONTEXT AND OBJECTIVE: Non-myeloablative hematopoietic stem cell transplantation (NMA-HSCT) is performed in onco-hematological patients who cannot tolerate ablative conditioning because of older age or comorbidities. This approach does not completely eliminate host cells and initially results in mixed chimerism. Long-term persistence of mixed chimerism results in graft rejection and relapse. Involvement of graft-versus-host disease is concomitant with complete chimerism and graft-versus-tumor effect. The aim of this study was to evaluate the prevalence of chimerism in onco-hematological patients who underwent NMA-HSCT. DESIGN AND SETTING: Observational clinical study on chimerism status after human leukocyte antigen-identical NMA-HSCT at the Discipline of Hematology and Hemotherapy of Universidade Federal de São Paulo (UNIFESP). METHODS: We sequentially analyzed the amplification of APO-B, D1S80, DxS52, FVW, 33.6, YNZ-2 and H-ras primers using variable number of tandem repeats (VNTR) on 17 pairs and fluorescent in situ hybridization (FISH) with the XY probe and SRY primer on 13 sex-unmatched pairs. RESULTS: The informativeness of the primers using VNTR was 60% for APO-B, 75% D1S80, 36% DxS52, 14% FVW, 40% YNZ-22 and 16% H-ras. The SRY primer was informative in female receptors with male donors. The XY-FISH method was informative in 100% of the sex-unmatched pairs. CONCLUSION: These methods were sensitive and informative. In VNTR, the association of APO-B with D1S80 showed 88% informativeness. The quantitative FISH method was more sensitive, but had the disadvantage of only being used for sex-unmatched pairs.