Physicians compliance during maintenance therapy in children with Down syndrome and acute lymphoblastic leukemia.

Children with Down syndrome (DS) and acute lymphoblastic leukemia (ALL) have an inferior prognosis compared with non-DS ALL patients. We reviewed methotrexate (MTX)/mercaptopurine (6MP) maintenance therapy data for children with DS treated according to the Nordic Society of Pediatric Hematology and Oncology (NOPHO) ALL92 or the NOPHO ALL2000 protocols between 1992 and 2007. The 5-year event-free survival probability (pEFS(5 yr)) for the 66 DS patients was inferior to the 2602 non-DS patients (0.50 ± 0.07 vs 0.77 ± 0.01 (P<0.001)). The 48 DS patients in first remission at the beginning of maintenance therapy had pEFS(10 yr) below that of the 522 non-DS control patients (pEFS(10 yr): 0.58 (95% confidence interval (CI) 0.43-0.77) vs 0.83 (95% CI 0.80-0.86), respectively (P<0.0001)). The DS patients received lower median doses of MTX (median: 11.8 vs 15.4 (P<0.0001)) and 6MP (median: 43.6 vs 59.4 (P<0.0001)). In Cox regression analysis, male gender, presence of DS and high median maintenance therapy white blood cell levels (mWBC) were associated with increased risk for relapse. DS-ALL patients with mWBC above or below 3.5 × 10(9)/l (protocol target) had pEFS(10 yr) of 0.31 and 0.72 (P=0.02), and the mWBC hazard ratio for DS-ALL patients was 2.0 (P<0.0005). We conclude that insufficient treatment intensity during maintenance therapy of DS-ALL patients may contribute to their poor prognosis.

Parametric dependence of single-bubble sonoluminescence spectra.

We present experimental spectra of single sonoluminescing bubble in water at different dissolved argon concentrations and excitation levels. All the relevant experimental conditions are either measured directly or derived from measured quantities for each spectrum, thus the parametric dependence of the spectra can be analyzed. To characterize the data in a given wavelength interval we fitted the shape of the spectra with the Planck function. The effective temperatures obtained from these fits lie in the range 12,000-18,000 K, practically independent of the expansion ratio, while the intensity normalized by the volume of the bubble increases with the expansion ratio as a power law. The effective temperatures decrease with the pressure amplitude for each argon concentration, while the light intensity, measured with a photomultiplier tube, increases. These observations suggest that the increased energy input due to the higher pressure amplitudes results in an increased number of less energetic photons as compared to the case of a lower excitation level.

Alternative method to deduce bubble dynamics in single-bubble sonoluminescence experiments.

In this paper we present an experimental approach that allows to deduce the important dynamical parameters of single sonoluminescing bubbles (pressure amplitude, ambient radius, radius-time curve). The technique is based on a few previously confirmed theoretical assumptions and requires the knowledge of quantities such as the amplitude of the electric excitation and the phase of the flashes in the acoustic period. These quantities are easily measurable by a digital oscilloscope, avoiding the cost of the expensive lasers or ultrafast cameras of previous methods. We show the technique in a particular example and compare the results with conventional Mie scattering. We find that within the experimental uncertainties these two techniques provide similar results.