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1.
Surg Oncol ; 20(3): 155-61, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20739177

RESUMO

In this essay we set out clinical communication challenges in surgical oncology. We draw directly on relevant examples where they are available. Otherwise, we refer to the more generic surgical and medical literature. We offer 'macro' and 'micro' perspectives on clinical communication. That is, exploring communication challenges at the level of the organization and between individuals, doctors and patients and interprofessionally across different settings. Training content and methods are reported that address the complex communication challenges associated with surgical oncology. Innovations in simulation-based education offer exciting new opportunities for formative and summative assessment. We outline limitations of the essay and finally propose the content of a surgical oncology communication program.


Assuntos
Competência Clínica , Comunicação , Comportamento Cooperativo , Educação de Pós-Graduação em Medicina/métodos , Cirurgia Geral/educação , Oncologia/educação , Neoplasias/cirurgia , Humanos , Relações Médico-Paciente
2.
Braz. j. med. biol. res ; 40(12): 1623-1629, Dec. 2007. tab
Artigo em Inglês | LILACS | ID: lil-466736

RESUMO

Allogeneic stem cell transplantation has been increasingly performed for a variety of hematologic diseases. Clinically significant acute graft-versus-host disease (GVHD) occurs in 9 to 50 percent of patients who receive allogeneic grafts, resulting in high morbidity and mortality. There is no standard therapy for patients with acute GVHD who do not respond to steroids. Studies have shown a possible benefit of anti-TNF-a (infliximab)for the treatment of acute GVHD. We report here on the outcomes of 10 recipients of related or unrelated stem cell transplants who received 10 mg/kg infliximab, iv, once weekly for a median of 3.5 doses (range: 1-6) for the treatment of severe acute GVHD and who were not responsive to standard therapy. All patients had acute GVHD grades II to IV (II = 2, III = 3, IV = 5). Overall, 9 patients responded and 1 patient had progressive disease. Among the responders, 3 had complete responses and 6 partial responses. All patients with cutaneous or gastrointestinal involvement responded, while only 2 of 6 patients with liver disease showed any response. None of the 10 patients had any kind of immediate toxicity. Four patients died, all of them with sepsis. Six patients are still alive after a median follow-up time of 544 days (92-600) after transplantation. Considering the severity of the cases and the bad prognosis associated with advanced acute GVHD, we find our results encouraging. Anti-TNF-a seems to be a useful agent for the treatment of acute GVHD.


Assuntos
Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Anticorpos Monoclonais/uso terapêutico , Glucocorticoides/uso terapêutico , Doença Enxerto-Hospedeiro/tratamento farmacológico , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Metilprednisolona/uso terapêutico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Doença Aguda , Quimioterapia Combinada , Seguimentos , Leucemia/mortalidade , Leucemia/cirurgia , Índice de Gravidade de Doença , Resultado do Tratamento
3.
Bioorg Med Chem Lett ; 17(22): 6138-41, 2007 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-17904844

RESUMO

The structure-activity relationships of new quinoline based compounds were investigated. Quinoline-5,8-dione and styrylquinoline scaffolds were used for the design of potentially active compounds. The novel analogues had comparable antiproliferative activity to cisplatin when evaluated in a bioassay against the P388 leukemia cell line. However, these compounds appeared far less efficient against SK-N-MC neuroepithelioma cells. Analogues without the 5,8-dione structure but containing the 8-carboxylic acid group were also found to induce antiproliferative activity. Hydrophobicity as measured by HPLC did not correlate with antiproliferative activity.


Assuntos
Antineoplásicos/farmacologia , Ácidos Carboxílicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Quinolinas/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Ácidos Carboxílicos/síntese química , Ácidos Carboxílicos/química , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Camundongos , Estrutura Molecular , Quinolinas/síntese química , Quinolinas/química , Relação Estrutura-Atividade
4.
Braz J Med Biol Res ; 40(12): 1623-9, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17713663

RESUMO

Allogeneic stem cell transplantation has been increasingly performed for a variety of hematologic diseases. Clinically significant acute graft-versus-host disease (GVHD) occurs in 9 to 50% of patients who receive allogeneic grafts, resulting in high morbidity and mortality. There is no standard therapy for patients with acute GVHD who do not respond to steroids. Studies have shown a possible benefit of anti-TNF-a (infliximab)for the treatment of acute GVHD. We report here on the outcomes of 10 recipients of related or unrelated stem cell transplants who received 10 mg/kg infliximab, iv, once weekly for a median of 3.5 doses (range: 1-6) for the treatment of severe acute GVHD and who were not responsive to standard therapy. All patients had acute GVHD grades II to IV (II = 2, III = 3, IV = 5). Overall, 9 patients responded and 1 patient had progressive disease. Among the responders, 3 had complete responses and 6 partial responses. All patients with cutaneous or gastrointestinal involvement responded, while only 2 of 6 patients with liver disease showed any response. None of the 10 patients had any kind of immediate toxicity. Four patients died, all of them with sepsis. Six patients are still alive after a median follow-up time of 544 days (92-600) after transplantation. Considering the severity of the cases and the bad prognosis associated with advanced acute GVHD, we find our results encouraging. Anti-TNF-a seems to be a useful agent for the treatment of acute GVHD.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Glucocorticoides/uso terapêutico , Doença Enxerto-Hospedeiro/tratamento farmacológico , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Metilprednisolona/uso terapêutico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Doença Aguda , Adolescente , Adulto , Criança , Pré-Escolar , Quimioterapia Combinada , Feminino , Seguimentos , Humanos , Infliximab , Leucemia/mortalidade , Leucemia/cirurgia , Masculino , Índice de Gravidade de Doença , Resultado do Tratamento
5.
Transplant Proc ; 36(4): 814-5, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15194280

RESUMO

Striking progress has been observed in the number of volunteer donors for hematopoietic stem cell transplantation in the last years in Brazil. By the end of 1998, the number of donors barely reached 4200 but it has grown progressively. It was close to 48,000 by the end of May 1993. It is possible to notice a steady increase from the first (1993 to 2000) to the last years (2001 to 2003). The regulation of each procedure by the Brazilian Health System, with the collaboration of the Hematology Societies, was essential for the success of Redome and for the stem cell transplantation program in Brazil. However, when analyzing these results some problems were detected: 95% of Redome donors come from the south and southeastern regions of the country, while few donors are from the north, northeast, and central parts of Brazil. The different miscegenation of races in different regions and states of Brazil makes this an important issue: to represent the whole Brazilian population, Redome must improve the donor search in such places. It also became clear that several other centers involved in unrelated hematopoietic transplantation must be accredited to avoid a long line of patients with compatible donors a waiting transplantation.


Assuntos
Medula Óssea , Experimentação Humana/estatística & dados numéricos , Sistema de Registros , Doadores de Tecidos/estatística & dados numéricos , Brasil , Humanos
6.
Acta Pol Pharm ; 61 Suppl: 3-4, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15909921

RESUMO

In our work, leading to new styrylquinoline and styrylquinazoline inhibitors of HIV integrase, we analyzed virtual combinatorial library that includes these compounds. Using this method we were able to find interesting synthetic targets. We optimized synthetic procedure yielding such compounds and obtained a couple of new analogues. Their activity will be evaluated in the near future.


Assuntos
Inibidores de Integrase de HIV/síntese química , Quinazolinas/síntese química , Quinazolinas/farmacologia , Quinolinas/síntese química , Quinolinas/farmacologia , Técnicas de Química Combinatória , Desenho de Fármacos , Inibidores de Integrase de HIV/farmacologia , Indicadores e Reagentes
7.
Cytotherapy ; 5(4): 336-45, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12944240

RESUMO

BACKGROUND: PBSC transplant provides 10 times more T cells than BMT However, the incidence and severity of acute GvHD is similar among recipients of both types of transplants. Studies in mouse models suggest that the similar clinical outcome in BMT and PBSCT is due to differences in the lymphokine profiles. METHODS: PBMC, PBMC from G-CSF mobilized donors (G-PBMC)and BM mononuclear cells (BM-MC) were analyzed by flow cytometry and ELISA to detect gamma-IFN and IL-4 production. Hematoxylin and eosin staining was used to identify morphology and annexin/propidium-iodide was used for apoptosis assays. RESULTS: We show decreased production of gamma-interferon (85%) and IL-4 (60%) in G-PBMC when compared with either PBMC or BM-MCT cells on ex vivo assays. Surprisingly, 85% of fresh G-PBMC is composed of low-density granulocytes (LDG), which undergo apoptosis after 48 h in culture. At this same time, gamma-IFN production from G-PBMC T cell was reverted. In vitro, G-CSF converts granulocytes into LDGs, able to inhibit T-cell function by H2O2 production, and not through immune-deviation towards a Th2-type phenotype. DISCUSSION: We show that the estimated numbers of Th1 and Th2 cells infused in BMT and PBSCT do not differ significantly. These findings are discussed with reference to the relatively low incidence of acute GvHD in PBSCT shown in the literature. We suggest that these results might depend on the high number of granulocytes and progenitors infused. The potential use of granulocytes as immunosupressive short-term therapy is now being investigated by our group using a mouse experimental model.


Assuntos
Granulócitos/fisiologia , Transplante de Células-Tronco de Sangue Periférico , Linfócitos T/fisiologia , Acetato de Tetradecanoilforbol/análogos & derivados , Anexina A5/análise , Antígenos CD/análise , Apoptose/fisiologia , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/fisiologia , Transplante de Medula Óssea , Complexo CD3/análise , Catalase/farmacologia , Contagem de Células , Citometria de Fluxo , Fator Estimulador de Colônias de Granulócitos/farmacologia , Granulócitos/citologia , Granulócitos/efeitos dos fármacos , Mobilização de Células-Tronco Hematopoéticas , Transplante de Células-Tronco Hematopoéticas , Humanos , Peróxido de Hidrogênio/metabolismo , Interferon gama/análise , Interleucina-4/análise , Ionomicina/farmacologia , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/fisiologia , Leucossialina , Teste de Cultura Mista de Linfócitos , Ativação de Neutrófilo/efeitos dos fármacos , Ativação de Neutrófilo/fisiologia , Sialoglicoproteínas/análise , Linfócitos T/química , Linfócitos T/efeitos dos fármacos , Acetato de Tetradecanoilforbol/farmacologia , Fatores de Tempo
8.
Bone Marrow Transplant ; 29(9): 745-51, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12040471

RESUMO

In order to assess the effect of delaying G-CSF administration after autologous peripheral blood progenitor cell (PBPC) transplantation on the duration of neutropenia, 87 patients were randomized to receive G-CSF 5 microg/kg/day starting on day +1 (n = 45) or +5 (n = 42) following PBPC transplantation, until recovery of the neutrophils. The duration of neutropenia (<0.5 x 10(9)/l) was shorter in the day +1 group (7 vs 8 days; P = 0.02), especially in patients receiving melphalan 200 mg/m(2) and CD34(+) cell doses >3.0 x 10(6)/kg. These patients had a later onset of neutropenia after transplant. There were no differences in time to neutrophil and platelet engraftment, or in the incidence of fever and documentation of infection. Although the duration of antibiotic therapy (7 vs 10.5 days; P = 0.01) and time to hospital discharge (13 vs 15 days; P = 0.02) were shorter in the day +1 group, these differences could not be predicted by the day of G-CSF initiation in multivariate analysis. Starting G-CSF on day +1 does not result in faster neutrophil engraftment but in later onset and consequently, slightly shorter duration of neutropenia in patients who receive melphalan 200 mg/m(2) and CD34(+) cell doses >3.0 x 10(6)/kg.


Assuntos
Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Transplante de Células-Tronco de Sangue Periférico/métodos , Adolescente , Adulto , Idoso , Esquema de Medicação , Feminino , Febre/etiologia , Febre/prevenção & controle , Sobrevivência de Enxerto/efeitos dos fármacos , Fator Estimulador de Colônias de Granulócitos/farmacologia , Neoplasias Hematológicas/complicações , Neoplasias Hematológicas/terapia , Hematopoese/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Neutropenia/prevenção & controle , Transplante de Células-Tronco de Sangue Periférico/efeitos adversos , Estudos Prospectivos , Transplante Autólogo/efeitos adversos , Transplante Autólogo/métodos , Resultado do Tratamento
9.
Bone Marrow Transplant ; 28(3): 311-2, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11536001

RESUMO

We report a case of capillary leak syndrome in a 37-year-old female PBPC donor who received G-CSF 900 microg/day for 4 days and underwent leukapheresis. This lady had remained well and stable despite marked leukocytosis during G-CSF treatment, but developed hypotension during leukapheresis, quickly followed by hypoxemia, ascites, pericardial and pleural effusion, shock, edema, neurologic changes and hepatocellular injury. Upon G-CSF withdrawal, dopamine and crystalloid infusion, methylprednisolone treatment and suspension of apheresis, the clinical situation fully reversed. We hypothesize that leukapheresis, in the presence of marked leukocytosis and high doses of G-CSF, may have triggered neutrophil activation and the release of inflammatory mediators, resulting in tissue damage and systemic manifestations of increased capillary permeability.


Assuntos
Doadores de Sangue , Síndrome de Vazamento Capilar/etiologia , Mobilização de Células-Tronco Hematopoéticas/efeitos adversos , Adulto , Feminino , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Fator Estimulador de Colônias de Granulócitos/toxicidade , Transplante de Células-Tronco Hematopoéticas , Humanos , Leucaférese , Leucocitose/induzido quimicamente , Leucocitose/complicações , Transplante Homólogo
10.
Bone Marrow Transplant ; 27(1): 73-8, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11244440

RESUMO

We investigated the use of 'prophylactic' donor lymphocyte infusions (DLI) containing 1 x 107 CD3+ cells, given at 30, 60 and 90 days post-allogeneic blood and marrow transplantation (BMT), following conditioning with fludarabine 30 mg/m(2)/4 days and melphalan 70 mg/m(2)/2 days. GVHD prophylaxis consisted of cyclosporin A (CsA) 2 mg/kg daily with early tapering by day 60. Our goals were the rapid achievement of chimerism and disease control, providing an immunological platform for DLIs to treat refractory patients with hematological malignancies. Twelve heavily pre-treated patients with life expectancy less than 6 months were studied; none were in remission. Diagnoses were AML (n = 4), MDS (n = 1), ALL (n = 3), CML (n = 3) and multiple myeloma (n = 1). Response rate was 75%. Three patients are alive at a median of 450 days (range, 450-540). Two patients are in remission of CML in blast crisis and AML for more than 14 months. Median survival is 116 days (range, 25-648). Six patients received 12 DLIs; three patients developed acute GVHD after the first infusion and were excluded from further DLIs, but no GVHD occurred among patients receiving subsequent DLIs. One patient with CML in blast crisis went into CR after the first DLI. The overall incidence of acute GVHD was 70%. Primary causes of death were infections (n = 3), acute GVHD (n = 3), chronic GVHD (n = 1) and disease relapse (n = 2). We observed high response and chimerism rates at the expense of an excessive incidence of GVHD. DLI given at day +30 post BMT caused GVHD in 50% of the patients, and its role in this setting remains unclear.


Assuntos
Neoplasias Hematológicas/terapia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Transfusão de Linfócitos/normas , Adolescente , Adulto , Antineoplásicos/uso terapêutico , Antineoplásicos/toxicidade , Causas de Morte , Criança , Feminino , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/mortalidade , Efeito Enxerto vs Leucemia , Neoplasias Hematológicas/complicações , Neoplasias Hematológicas/mortalidade , Transplante de Células-Tronco Hematopoéticas/mortalidade , Humanos , Transfusão de Linfócitos/efeitos adversos , Transfusão de Linfócitos/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Indução de Remissão/métodos , Prevenção Secundária , Quimeras de Transplante
12.
Leuk Res ; 24(10): 839-48, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10996202

RESUMO

Several studies have demonstrated the prognostic value of cytogenetic analysis in MDS both for survival and progression to AML. However it is unknown which are the numerical or structural abnormalities required for leukemic transformation. In this report we studied clinically and cytogenetically 127 patients: 125 with primary MDS and two with AML with a previous history of MDS. Thirty-one patients (24%) showed evolution of the disease during the follow-up study. Chromosomal abnormalities found at diagnosis in patients that progressed toward AML included: del(5)(q15), +6, del(6)(q21), t(5;8)(q32;q22),-7, del(7)(q22), der(7)t(1;7)(q10;p10), t(7;11)(p15;p15), +8, del(11)(q23), del(12p), del(3)(q21), del(20)(q12) and complex karyotypes. Eight of these patients were studied cytogenetically during transformation and showed acquisition of chromosomal alterations involving dup(1q), +8, del(11)(q23), and translocations between chromosomes 1 and 8 or 7 and 17. In addition we also observed gain of ploidy and monosomy 21. These results suggest that chromosomal alterations during evolution of the disease include special chromosome gains or abnormalities of chromosomes 1, 7, 8, 11 and 17 with involvement of ETV-1, Hox-A9, Pax 4, MLL genes besides a putative gene mapped at 17q25. We also applied the International Prognostic Scoring System (IPSS) to 114 patients, excluding those submitted to allogeneic bone marrow transplant. Our patients were classified into four distinct risk groups. The analysis of risk groups presented by 27 patients who showed evolution of the disease revealed 18 at the high risk group and four at the intermediate-2 group. From the intermediate-1 risk group only five patients showed evolution of the disease. Three of these patients evolved from RA to RAEB with gain of a del(11)(q23) or an expansion of a del(12)(p12) clone. Our results suggest that some chromosomal alterations are responsible for each step in the evolution of the disease. As the pathway of evolution is not unique it has been very difficult to define what genetic alteration comes first. However from several results in the literature and our own, it seems that some chromosomal alterations may predict the evolution of the disease and are correlated with short survival, as for example the trisomy of chromosome 8, and might be incorporated in the high risk group in the IPSS. This score system has been proved to be useful for predicting survival and evolution from MDS to AML.


Assuntos
Aberrações Cromossômicas , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicas/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Cariotipagem , Masculino , Pessoa de Meia-Idade
13.
Cancer Genet Cytogenet ; 117(2): 104-7, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10704678

RESUMO

The development of acute megakaryoblastic leukemia (ANLL-M7) following myelodysplastic syndrome (MDS) has been described only in a few reports, and the mutations necessary for this transformation are still unknown. In this study, we describe a case of ANLL-M7 with a previous history of MDS presenting a complex karyotype 46,XX, t(4;11)(q21;q23),del(5)(q13q33),t(12;13)(p13;q21) and N-RAS point mutation. During MDS, the patient showed a hypercellular myelogram with dysplasia of the three myeloid lineages and the clinical symptoms characteristic of the 5q- syndrome. During the follow-up, we observed the appearance of two additional subclones, one with an isochromosome 17q and another with polyploidy. The presence of an isochromosome 17q in one subclone and polyploidy in another is probably due to the genetic instability generated by the malignant transformation.


Assuntos
Cromossomos Humanos Par 13 , Genes ras , Leucemia Megacarioblástica Aguda/genética , Aberrações Cromossômicas , Bandeamento Cromossômico , Códon , Evolução Fatal , Feminino , Humanos , Hibridização in Situ Fluorescente , Cariotipagem , Leucemia Megacarioblástica Aguda/etiologia , Leucemia Megacarioblástica Aguda/terapia , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/complicações , Síndromes Mielodisplásicas/genética , Mutação Puntual , Reação em Cadeia da Polimerase
14.
Leuk Lymphoma ; 37(1-2): 205-11, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10721788

RESUMO

Single-step Multiplex RT-PCR was used as a rapid and highly sensitive method for screening patients with myeloproliferative conditions and ALL for the presence of underlying BCR-ABL gene fusions. Positive and negative results obtained with the multiplex assay were subsequently confirmed by nested PCR. We studied 21 patients for detecting the presence of b3a2, b2a2 and e1a2 BCR-ABL transcripts at diagnosis and following treatment with different therapeutical procedures. These studies allowed the molecular characterisation of patients with different haematological disorders and for demonstrating BCR-ABL transcripts in Ph-CML. In a Ph+ CML patient, a switch of isoforms was detected after bone marrow transplantation and infusion with donor lymphocytes, implying substitution of e1a2 for b3a2 coexisting with a myeloid/lymphoid biphenotypic profile. In ALL, one Ph+ patient showed coexpression of e1a2 and b2a2 at diagnosis followed by persistence of e1a2 after bone marrow transplantation. Our results were compared to previous findings in the literature on molecular diagnosis of leukaemias.


Assuntos
Proteínas de Fusão bcr-abl/metabolismo , Neoplasias Hematológicas/metabolismo , DNA Complementar , Proteínas de Fusão bcr-abl/genética , Neoplasias Hematológicas/genética , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Reação em Cadeia da Polimerase , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , RNA/análise
16.
Leuk Res ; 23(2): 185-90, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10071134

RESUMO

Polymerase chain reaction (PCR) is a powerful and rapid method for specifically detecting BCR-ABL rearrangement by amplification of the complementary DNA (cDNA) produced by reverse transcription of BCR-ABL mRNA. We studied 29 patients for detecting the presence of BCR-ABL transcripts before and after bone marrow transplantation (BMT). Our sample was composed of two different groups of patients: one group (n = 18) was studied by serial follow-ups before and after BMT; a second group (n = 11) was studied several years after BMT. Detection of BCR-ABL was carried out with different primer sets at different periods of the clinical outcome of chronic myeloid leukaemia (CML). A comparison of PCR data and clinical-haematological conditions showed clear differences between patients. In the first group, eight patients showed a positive correlation between a favourable clinical outcome and molecular remission. Conversely, in the second group, six patients were BCR-ABL positive between 20 and 117 months after BMT, while only two of these patients showed signs of clinical relapse. Among all patients whose isoforms were known at some time during the course of CML, the more frequent isoform was b3a2. These results were compared to previous findings in the literature on diagnosis, outcome and prognosis of CML.


Assuntos
Proteínas de Fusão bcr-abl/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Reação em Cadeia da Polimerase , RNA Mensageiro/análise , Transplante de Medula Óssea , Humanos
17.
Leuk Res ; 22(2): 125-34, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9593469

RESUMO

A cytogenetic and N-ras point mutation study was done in patients with primary myelodysplastic syndrome (MDS) from Rio de Janeiro, Brazil, in order to evaluate the progression of preleukemic states to overt leukemia. Cytogenetic analysis was performed in 50 patients with MDS and clonal chromosomal abnormalities were detected in 19 (38%) of them. Patients with refractory anemia (RA) or with ringed sideroblasts (RARS) presented normal karyotypes or single abnormalities as del(5q) or -Y, while patients in more advanced states as RA with excess of blasts (RAEB), RAEB in transformation (RAEB-t) and chronic myelomonocytic leukemia (CMML) showed complex karyotypes and single abnormalities involving chromosomes 7 or 8, which were related to poor prognosis and elevated risk of transformation to acute myeloid leukemia (AML). The frequency of ras activation was studied in these 50 patients with MDS. Samples of bone marrow were screened for oncogenic point mutations by DNA amplification followed by oligonucleotide hybridization analysis (PCR-ASO) at codon 12 of N-ras proto-oncogene. We detected N-ras point mutations in 21 patients (42%). Progression from MDS to AML was observed in 9 patients (18%). The correlation analysis between N-ras point mutations and specific chromosomal abnormalities indicated that although mutated N-ras was found in cells with del(5q) and monosomy 7, cells with those abnormalities and normal N-ras were also identified. Otherwise trisomy of chromosome 8 showed a correlation with N-ras point mutations and in all cases, patients showed progression of MDS to AML during the follow-up study. MDS comprises a heterogeneous group of hematopoietic disorders and probably several steps are implicated in the evolution to AML. In this work we suggest that one possible pathway of leukemogenesis in MDS includes N-ras point mutations in association with trisomy of chromosome 8.


Assuntos
Aberrações Cromossômicas , Transtornos Cromossômicos , Genes ras , Síndromes Mielodisplásicas/genética , Mutação Puntual , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Transformação Celular Neoplásica/genética , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Proto-Oncogene Mas
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