Objective To evaluate the impact of the percentage of residual blasts in bone marrow at the end of induction chemotherapy ( T1 ) or during myelosuppression phase (T2) on prognosis of de novo acute myeloid leukemia(AML) (non M3) in 105 cases.To refine AML risk-stratification by combining the percentage of residual blast cells (T1 or/and T2) with cytogenetic data based the South West Oncology Group (SWOG) criteria.Methods The data of 105 de novo AML ( non M3 ) patients hospitalized between January 1st 1999 and February 1st 2008 were retrospectively reviewed.Results were analyzed with SPSS15.0 software.Results ( 1 ) Patients were divided into two subgroups by a cutoff of 5% residual bone marrow blasts at T1 or 12 time point.Patients with percentage of residual bone marrow blast cells <5% had better complete remission (CR) rate,relapse-free survival (RFS) and overall survival (OS) than the patients with percentage ≥5% at T1 or T2.The percentage of residual bone marrow blast cells at T1 was correlated with that at T2.(2) The prognosis of patients with intermediate karyotypes with percentage < 5 % at T1 or T2 was similar to that of the patients with favorable karyotypes.The patients with intermediate karyotypes and percentage of residual bone marrow blasts ≥5% at TI or T2 are defined as a subgroup with prognosis similar to that of patients with unfavorable karyotypes.(3) COX regression analysis showed that the percentage of residual bone marrow blasts at T1 or T2 is an independent prognostic factor of AML.The percentage of residual bone marrow blasts at T1 may be more helpful in prognostification than that at T2.Conclusion AML patients with percentage of residual bone marrow blasts < 5% after induction chemotherapy ( T1 or T2) have better CR rate,RFS,OS than the patients with percentage ≥5% at the same time point.Combination of cytogenetics and percentage of residual bone marrow blasts at T1 or T2 is helpful to divide patients with intermediate karyotypes into two subgroups with different prognosis.Thus,a better decision of treatment strategy can be designed.

The oligonucleotide microarray, a high-throughput polymorphism detection technology, holds great promise for the characterization of complex genetic variance. To achieve greater sensitivity and specificity for it to be an effective platform technology we present results and discuss some of the factors influencing signal intensities and single-mismatch discrimination in array-based mutation/SNP detection. Probes with a series of concentrations were spotted onto the slide in order to find the optimal concentration with the identifiable satisfying signals and the stable ratios between matched and mismatched probes. It was found that under our experimental conditions, when the initial probe concentration is higher than the maximum immobilization capability of the slide (7.5 micrometer), the hybridization signal will be saturated and the ratio between matched and mismatched probes will be more stable than at a lower probe concentration. Considering the cost of probes and the systematic stability, a constant spotting concentration of 10 micrometer was selected. The stability of different types of mismatched oligo-DNA duplexes on the glass surface was also confirmed. The results show that the order of stability of mismatched oligo-DNA duplexes on a glass surface is in general agreement with previous reports conducted using liquid and polyacrylamide gel pads. This suggests that the influence of the mismatched base pair on the stability of the duplex in a solid hybridization system is similar to that in the solution hybridization environment.
Nucleic Acid Heteroduplexes/chemistry ; *Nucleic Acid Hybridization ; *Oligonucleotide Array Sequence Analysis ; Oligonucleotide Probes/chemistry ; *Polymorphism, Single Nucleotide ; Research Support, Non-U.S. Gov't