RESUMO
The investigation deals with a simplified modification or molecular-genetic detection of translocation t(9;22) using a combination of reverse transcription and polymerase chain reactions (RT-PCR). Unlike the available protocols, analysis is carried out using one enzyme--TET-Z polymerase--(instead of two) which has both revertase and DNA-polymerase activities. The present modification is highly sensitive, less time-consuming and cheaper. The method has proved useful for both diagnosing t(9;22) translocation and diagnosing and monitoring minimal residual disease remaining after marrow transplantation.
Assuntos
Cromossomos Humanos Par 22/genética , Cromossomos Humanos Par 9/genética , Neoplasia Residual/diagnóstico , Neoplasia Residual/genética , Reação em Cadeia da Polimerase , Translocação Genética , Humanos , Reação em Cadeia da Polimerase/métodos , DNA Polimerase Dirigida por RNARESUMO
To elucidate feasibility of accurate diagnosis of chronic myeloid leukemia (CML) without cytogenetic and molecular-genetic investigations as well as to specify CML diagnostic criteria, clinicohematological parameters were compared in two groups of patients: with Ph'-chromosome and/or rearrangement of fragment bcr (group 1), with unknown karyotype in whom detection of bcr fragment rearrangement was not made. Clinicohematological parameters in both groups were close in absolute value and underwent parallel changes in the course of leukemia progression. In group 1, patients in progressive and blastic phase compared to patients in chronic phase had a 14-fold increase in the number of additional cytogenetic anomalies. In patients with tumor transformation fragment bcr underwent rearrangement according to type B2A2. Thus, the diagnosis of typical CML variants is feasible without detection of Ph'-chromosome and/or rearrangement of bcr fragment. It is especially true and essential for patients in the chronic phase. The data obtained provide more accurate diagnostic criteria of CML.
Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Adolescente , Adulto , Idoso , Medula Óssea/ultraestrutura , Progressão da Doença , Hepatomegalia/diagnóstico , Humanos , Cariotipagem , Leucemia Mielogênica Crônica BCR-ABL Positiva/sangue , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Esplenomegalia/diagnóstico , Células Tumorais CultivadasRESUMO
The authors studied spontaneous DNA damages and the extra plan synthesis of DNA in various leukemias (chronic lympholeukemia, chronic myeloleukemia, acute leukemia) to predict the natural course of leukemias and the efficiency of chemotherapy. The level of genuine DNA breaks, which had been determined by the nic-translation test, was lower in peripheral blood cell DNA in all leukemias than that in the lymphocytes and granulocytes from donors. On the contrary, the levels of alkaline-labile DNA sites and nuclear matrix protein-bound DNA in the mature and maturing leukemia cells are high and decrease with progression of chronic lympholeukemia and chronic myeloleukemia. The extra plan DNA synthesis largely reflects the cellular levels of genuine DNA breaks, and the ultraviolet-induced DNA repair capacity is the highest in the lymphocytes in chronic lympholeukemia and particularly in the blasts in acute leukemia. The efficiency of chemotherapy was predicted during chemotherapy from the intensity of formation of genuine blast cell DNA breaks.