In Vitro Transformation of Primary Human CD34+ Cells by AML Fusion Oncogenes: Early Gene Expression Profiling Reveals Possible Drug Target in AML

Different fusion oncogenes in acute myeloid leukemia (AML) have distinct clinical and laboratory features suggesting different modes of malignant transformation. Here we compare the in vitro effects of representatives of 4 major groups of AML fusion oncogenes on primary human CD34+ cells. As expected from their clinical similarities, MLL-AF9 and NUP98-HOXA9 had very similar effects in vitro. They both caused erythroid hyperplasia and a clear block in erythroid and myeloid maturation. On the other hand, AML1-ETO and PML-RARA had only modest effects on myeloid and erythroid differentiation. All oncogenes except PML-RARA caused a dramatic increase in long-term proliferation and self-renewal. Gene expression profiling revealed two distinct temporal patterns of gene deregulation. Gene deregulation by MLL-AF9 and NUP98-HOXA9 peaked 3 days after transduction. In contrast, the vast majority of gene deregulation by AML1-ETO and PML-RARA occurred within 6 hours, followed by a dramatic drop in the numbers of deregulated genes. Interestingly, the p53 inhibitor MDM2 was upregulated by AML1-ETO at 6 hours. Nutlin-3, an inhibitor of the interaction between MDM2 and p53, specifically inhibited the proliferation and self-renewal of primary human CD34+ cells transduced with AML1-ETO, suggesting that MDM2 upregulation plays a role in cell transformation by AML1-ETO. These data show that differences among AML fusion oncogenes can be recapitulated in vitro using primary human CD34+ cells and that early gene expression profiling in these cells can reveal potential drug targets in AML

Inhibition of K+ efflux and dehydration of sickle cells by [(dihydroindenyl)oxy]alkanoic acid: an inhibitor of the K+ Cl- cotransport system.

[(Dihydroindenyl)oxy]alkanoic acid (DIOA) was recently introduced as a potent inhibitor of the K+Cl- cotransport system without side effects on other cation transport systems [Garay, R. P., Nazaret, C., Hannaert, P.A. & Cragoe, E. J., Jr. (1988) Mol. Pharmacol. 33, 696-701]. In sickle cells, an abnormal activation of this K+Cl- cotransport system was proposed to be involved in cell K+ loss and dehydration. We found that DIOA inhibited the abnormal sickle cell K+ loss and specifically reduced sickle cell density upon stimulation of the net outward K+Cl- cotransport--i.e., low pH, hypoosmolarity, and activation by N-ethylmaleimide. DIOA opens another therapeutic approach to sickle cell disease by inhibiting cell dehydration, which favors HbS polymerization and reduces erythrocyte deformability

High pressure XANES and XMCD in the tender X-ray energy range

International audienceWe have developed an experimental setup at the ESRF beamline ID12 dedicated to X-ray absorption and magnetic circular dichroism measurements at high pressure adapted for the tender X-ray energy range and compatible with low temperatures and with high magnetic field. The focused incoming X-ray beam passes through a thin diamond disk attached to a fully perforated diamond anvil and X-ray fluorescence photons from the sample are collected in back-scattering geometry through the same diamond disk. The pressure in the cell is measured using the ruby luminescence through a full diamond anvil. The highest pressure attainable with this diamond anvil cell (DAC) depends on the thickness of the diamond disk and it is above 16 GPa for a 80-μm thick plate and exceeds 4.5 GPa in the case of 30-μm diamond disk. Excellent performances of this setup in the tender X-ray range are illustrated with X-ray absorption near-edge structure studies of the phase transitions in KCl at the potassium and chlorine K-edges (3.61 and 2.82 keV, respectively) as well as in CdS at the sulfur K-edge (2.47 keV). This DAC together with a dedicated total fluorescence yield (TFY) detector could be mounted in the main heat exchanger of a cryostat and inserted in a bore of a superconducting magnet, this makes possible to perform X-ray magnetic circular dichroism (XMCD) experiments at low temperature, high magnetic field and high pressure. Feasibility of this approach is shown with the XMCD results obtained at the U M4,5-edges in ferromagnetic superconductor UGe2

National influenza surveillance systems in five European countries: a qualitative comparative framework based on WHO guidance

Background Influenza surveillance systems vary widely between countries and there is no framework to evaluate national surveillance systems in terms of data generation and dissemination. This study aimed to develop and test a comparative framework for European influenza surveillance. Methods Surveillance systems were evaluated qualitatively in five European countries (France, Germany, Italy, Spain, and the United Kingdom) by a panel of influenza experts and researchers from each country. Seven surveillance sub-systems were defined: non-medically attended community surveillance, virological surveillance, community surveillance, outbreak surveillance, primary care surveillance, hospital surveillance, mortality surveillance). These covered a total of 19 comparable outcomes of increasing severity, ranging from non-medically attended cases to deaths, which were evaluated using 5 comparison criteria based on WHO guidance (granularity, timing, representativeness, sampling strategy, communication) to produce a framework to compare the five countries. Results France and the United Kingdom showed the widest range of surveillance sub-systems, particularly for hospital surveillance, followed by Germany, Spain, and Italy. In all countries, virological, primary care and hospital surveillance were well developed, but non-medically attended events, influenza cases in the community, outbreaks in closed settings and mortality estimates were not consistently reported or published. The framework also allowed the comparison of variations in data granularity, timing, representativeness, sampling strategy, and communication between countries. For data granularity, breakdown per risk condition were available in France and Spain, but not in the United Kingdom, Germany and Italy. For data communication, there were disparities in the timeliness and accessibility of surveillance data. Conclusions This new framework can be used to compare influenza surveillance systems qualitatively between countries to allow the identification of structural differences as well as to evaluate adherence to WHO guidance. The framework may be adapted for other infectious respiratory diseases

VENOGRAPHY OF THE LOWER-LIMBS - PITFALLS OF THE DIAGNOSTIC STANDARD

RATIONALE AND OBJECTIVES. Phlebography is considered the diagnostic standard for suspected deep venous thrombosis. The authors studied the inter-observer variability of phlebogram interpretation in the setting of a multicenter therapeutic trial of the thrombolytic agent alteplase. METHODS. The interpretation of 31 pairs of venograms (before and after thrombolytic therapy) was studied by comparing the quantitative Marder's scores which were computed by three experts and the qualitative assessment of phlebographic changes induced by thrombolysis by the panel of experts and by the investigators. RESULTS. Although the scores of the three experts correlated fairly well (r = .67-.82; P <.001), they differed significantly from each other (P <.0001). Substantial differences also were found between local (by investigators) qualitative evaluation of the venographic changes induced by the treatment and central evaluation by the panel of experts (coefficient of agreement kappa = 0.19), local assessment being significantly more optimistic (P = .002) than central judgment. CONCLUSION. Significant differences were observed between assessment of changes in venographic scores after thrombolytic treatment both among three expert radiologists, and between the panel of experts and the local investigators of the multicenter trial. This observation points to the need for an a priori definition of well-characterized decision criteria to allow a valid interpretation of the effects of the therapeutic intervention