Anti-MNDA (full length) polyclonal antibody

Introduction: Drug resistance and the gene expression profiles might discriminate the therapy outcome, and indicate the subgroup of patients with poor prognosis. In this study we analyzed the gene expression profile in correlation with the profile of ex vivo resistance to etoposide in children with acute leukemias. Methods: The ex vivo drug resistance profile was determined by the MTT cytotoxicity assay performed on leukemic blasts of 56 patients. Gene expression profiles were obtained from the results of hybridization of cRNA to Human Genome U133A 2.0 ologonucleotide arrays. The following analyses were performed: correlation analysis, hierarchical clustering, the assignment of location and function. Verification of data for four selected genes (MNDA, GH1, NUDT21, RHOG) was performed by quantitative real time polymerase chain reaction in the studied population and in an independent group of 54 leukemic patients. Results: Using the permutation Spearman correlation test, a set of 233 probes/209 genes was selected. The global test confirmed the significance of the correlation of gene expression profile and resistance to etoposide (p<0.001). The NUDT21 (nudix, nucleoside diphosphate linked moiety X-type, motif 21) gene showed the strongest correlation with resistance to etoposide (FDR<0.0001%). Conclusions: Profiling of transcriptome may help in assessing the sensitivity to drugs used in chemotherapy. Resistance to etoposide is possibly associated with a change of expression of a large number of biologically important genes that influence several cellular mechanisms.

A semicrystalline polymer, isotactic poly(phenyl glycidyl ether) (i-PPGE) was used as a modifier for epoxy resin; 1,8-Diamino-p-methane (MNDA) and 4,4'-Diamino diphenyl sulfone (DDS) were used as curing agents. In the MNDA-cured resins, the dispersed phase were spherical particles with diameters in the range of 0.5-1.0 mum when the resin was blended with 5 phr i-PPGE. In the DDS-cured resins, the particle size distribution of the dispersed phase was much wider. The difference was traced back to the reactivity of the curing agent and the different regimes used for curing. Through dynamic mechanical analysis, it was found that in the MNDA-cured systems, i-PPGE had a lower crystallinity than in the DDS-cured system. In spite of the remarkable difference in the morphology and microstructure of the modified resins cured with these two curing agents, the toughening effects of i-PPGE were similar for these resins. The critical stress intensity factor (K-IC) was increased by 54% and 53%, respectively, for the resins cured by DDS and by MNDA, blending with 5 phr of the toughner. i-PPGE was comparable with the classical toughners carboxyl-terminated butadiene-acrylonitrile copolymers in effectiveness of toughening the epoxy resin. An advantage of i-PPGE was that the modulus and the glass-transition temperature of the resin were less affected. However, this modifier caused the flexural strength to decrease somewhat. (C) 2002 Wiley Periodicals, Inc.