RESUMO
DNA studies of the translocation t(15;17) in acute promyelocytic leukemia (APL) have shown that the retinoic acid receptor alpha (RARA) gene on chromosome 17 is juxtaposed to the promyelocytic leukemia (PML) gene on chromosome 15. The PML breakpoints have been mapped to 3 clusters: bcr1, bcr2, and bcr3. We have examined the PML breakpoint distribution in a series of 33 Chinese patients with APL. Twenty-two patients fell within bcr1, 2 within bcr2, and 9 within bcr3. The primary structure of the reciprocal chromosome translocation joints of one patient and that of their normal counterparts have been determined and compared to those of 2 previously reported cases. These studies revealed possible topoisomerase II cleavage sites close to the breakpoints and suggested implications of DNA attachment sites to nuclear matrix. We propose that these features are relevant to the process of illegitimate recombination generating the translocation.
Assuntos
Proteínas de Transporte/genética , Cromossomos Humanos Par 15/ultraestrutura , Cromossomos Humanos Par 17/ultraestrutura , Rearranjo Gênico , Genes , Leucemia Promielocítica Aguda/genética , Translocação Genética , Sequência de Bases , Sequência Consenso , Análise Mutacional de DNA , DNA Topoisomerases Tipo II/genética , Humanos , Íntrons , Dados de Sequência Molecular , Proteínas de Neoplasias/genética , Receptores do Ácido Retinoico , Proteínas Recombinantes de Fusão/genética , Homologia de Sequência do Ácido Nucleico , Fatores de Transcrição/genéticaRESUMO
The configuration of the P53 tumor suppressor gene was investigated in 43 Chinese patients with chronic myelogenous leukemia (CML), 32 in chronic phase and 11 in blastic crisis. No obvious rearranged DNA band was detected in Southern blot patterns from patients at both stages of the disease. However, P53 gene deletion events were observed in 4 out of 11 cases in blast crisis. This finding was associated with a cytogenetically identifiable chromosome 17p deletion, iso(17q), in only one out of 4 cases.
Assuntos
Crise Blástica/genética , Deleção Cromossômica , Genes p53/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Adulto , Idoso , Alelos , Southern Blotting , Criança , China , Feminino , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Masculino , Pessoa de Meia-IdadeRESUMO
In 100 cases with autoimmune hemolytic anemia, Coombs test was directly positive in 77 cases (77%). 82 patients had warm autoantibodies. IgM was increased in 12 patients. 3 patients were diagnosed as lymphoma with titers more than 1:1024. One patient had paroxysmal cold hemoglobinuria. The dramatic clinical response to corticosteroid therapy was observed in patients with warm autoantibodies. However, immunosuppressor should be given to patients with cold autoantibodies. It was suggested that combined therapy with two drugs may be more effective than the use of corticosteroid alone. Of 6 patients in whom splenectomy was performed, 4 showed excellent results. Out of 100 cases, there were 23 with Evans syndrome.