Additional chromosomal abnormalities in core-binding factor acute myeloid leukemia.

Despite sharing a similar genetic abnormality, patients with core binding factor acute myeloid leukemia (CBF-AML), which is characterized by the presence of t(8;21) or inv(16)/t(16;16), show heterogeneous survival. Other molecular or cytogenetic factors are supposed to have an impact on the prognosis. We enrolled 24 CBF-AML patients to determine the impact of cytogenetic abnormality, and c-KIT, FLT3, NPM1, and CEBPA mutations on the prognosis. Only three patients had the c-KIT mutation (3/24, 12.5%) and one had the FLT3 mutation. However, over half of the patients (14/24) harbored additional cytogenetic changes, including ten with loss of sexual chromosomes (LOS) [all in the t(8;21) group], and six had additional abnormalities (two cases had both LOS and additional abnormalities). From this small-number study, no association was found between c-KIT mutation and survival and relapse rate. However, additional chromosome abnormalities had a significant association with relapse of the disease (P = 0.027). Stem cell transplant had a trend of benefitting patients after relapse (P = 0.065). This implies that chromosome abnormalities occur in CBF-AML and might take part in the heterogeneous nature of CBF-AML.

Prognostic implication of molecular aberrations in cytogenetically normal acute myeloid leukemia patients receiving allogeneic hematopoietic stem cell transplantation.

Different molecular aberrations can be discriminated into certain prognostic subgroups in cytogenetically normal acute myeloid leukemia (CN-AML) patients but their impact on allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains controversial and studies from Asian populations are lacking. Forty-two adult non-M3 AML patients receiving allo-HSCT from 2002 to 2009 in southern Taiwan were retrospectively reviewed for survey, 23 (54.7%) of whom were CN-AML. NPM1, FLT3-ITD, and CEBPA were analyzed. After a median follow-up of 104 weeks (range, 8 to 384), patients in the good risk group (harboring either NPM1 or CEBPA mutation without concurrent FLT3-ITD) showed a borderline worse overall survival (OS) compared with the intermediate/poor risk group (P = 0.08). Interestingly, a poorer OS was found in patients with the CEBPA mutation (P = 0.003) but not the NPM1 mutation (P = 0.96). No OS difference was found between patients with or without FLT3-ITD (P = 0.15). In patients receiving allo-HSCT at first remission, there was no significant OS benefit in the good risk group (P = 0.33). In patients receiving allo-HSCT beyond first remission, disease status played a major role (P = 0.006), irrespective of molecular aberrations. Allo-HSCT in good risk patients should be carefully evaluated in Taiwanese, especially in patients with the CEBPA mutation. Conversely, allo-HSCT should be considered in first remission in patients with an intermediate/poor risk, where it may overcome the adverse impact of FLT3-ITD. Disease status remained a main issue in patients receiving allo-HSCT beyond first remission.

Expression and cellular localization of ribonucleotide reductase small subunit M2 protein in hydroxyurea-resistant Leishmania mexicana amazonensis.

We raised a specific antiserum against the recombinant M2 subunit protein of ribonucleotide reductase of Leishmania mexicana amazonensis in rabbit. This antiserum was used to study the expression and cellular location of the M2 protein in wildtype as well as hydroxyurea-resistant variants (HuR) of the parasite. The protein increased with increasing dose of the drug used for selection of resistance. The increase in protein level was accompanied by an increase in the copy numbers of mRNA of the M2 gene in the variants. In contrast to mammalian cells, the M2 protein of Leishmania is located in the nucleus rather than in the cytoplasm. The number of cells expressing M2 protein is also different in mammalian cells versus Leishmania. In mammalian cells, expression of M2 protein is a strictly S-phase-correlated event and in exponentially growing cells only approximately 50% of the cells are in S-phase and only these cells synthesize M2 protein. In L. m. amazonensis, however, almost all exponentially growing cells are positive for M2 protein. This makes it unlikely that M2 protein expression in Leishmania is S-phase dependent. In view of these findings, a fresh look in the future into the regulatory mechanisms of synthesis and the site of action of RNR in L. m. amazonensis is warranted.

Acute changes in endothelin-1 after hemodialysis for chronic renal failure.

Endothelin is a recently described, potent renal vascular and systemic vasoconstrictor peptide. To evaluate the response of this peptide to volume contraction, we measured eight baseline and posthemodialysis samples from seven children, aged 14.5 +/- 3 years, with chronic renal failure. Plasma was extracted and endothelin-1 was measured by radioimmunoassay. Dialysis was performed for a 3- to 3 1/2-hour period, and body weight decreased from 38.0 +/- 14.3 to 36.2 +/- 13.8 kg (p < 0.01) during this time. There were no significant changes in heart rate or respiratory rate after dialysis, but blood pressure fell from 127/80 +/- 22/16 to 114/72 +/- 20/21 mm Hg (p = 0.05 for the systolic pressure). Plasma endothelin-1 concentration increased from 1.5 +/- 1.2 pg/ml at baseline to 7.3 +/- 8.9 pg/ml (p = 0.06) after dialysis; the fall in body weight from dialysis correlated with the increase in endothelin (r = -0.75; p = 0.05). Thus volume contraction from hemodialysis is associated with a rise in plasma endothelin-1, which is related to the acute change in body weight.

Equipment replacement policy: a survey.

Over the past ten years there has been a considerable increase in application of theoretically correct measurement methods in determining the economic life of equipment. Approximately 89% of the firms surveyed have equipment replacement policies. The discounted rate of return method is the most widely used in determining the service life of equipment; the MAPI formula is not widely used. Difficulties in applying a replacement policy can be classified into three groups: operational, organizational, and economic. The problems mentioned most often are operational. In organizational difficulties there is usually a lack of coordination between staff and line managers. Economic problems are generally the limited funds available for equipment replacement. Formal educational programs are lacking for the development of equipment replacement managers. For the firms having replacement policies, individuals with engineering degrees are preferred over those in other disciplines for the management of the equipment replacement policy.