Differential signaling networks of Bcr-Abl p210 and p190 kinases in leukemia cells defined by functional proteomics

The two major isoforms of the oncogenic Bcr–Abl tyrosine kinase, p210 and p190, are expressed upon the Philadelphia chromosome translocation. p210 is the hallmark of chronic myelogenous leukemia, whereas p190 occurs in the majority of B-cell acute lymphoblastic leukemia. Differences in protein interactions and activated signaling pathways that may be associated with the different diseases driven by p210 and p190 are unknown. We have performed a quantitative comparative proteomics study of p210 and p190. Strong differences in the interactome and tyrosine phosphoproteome were found and validated. Whereas the AP2 adaptor complex that regulates clathrin-mediated endocytosis interacts preferentially with p190, the phosphatase Sts1 is enriched with p210. Stronger activation of the Stat5 transcription factor and the Erk1/2 kinases is observed with p210, whereas Lyn kinase is activated by p190. Our findings provide a more coherent understanding of Bcr–Abl signaling, mechanisms of leukemic transformation, resulting disease pathobiology and responses to kinase inhibitors.

A pilot project of school-based intervention integrating drama and language awareness

BACKGROUND

  To help immigrant and refugee adolescents experiencing a severe academic delay cope with adversity, a school-based intervention combining drama workshops and language awareness activities was piloted in two classrooms.

METHOD

  A qualitative analysis of participant observations was performed and the Strength and Difficulty Questionnaire and its Impairment Supplement was administered before and after the intervention. The observations were carried out in two Montreal high schools serving an underprivileged neighbourhood of immigrants, involving two classrooms of underschooled adolescents (n = 27) and two classes of similarly underschooled adolescents chosen among other teachers interested in the intervention, who accepted to participate as a comparison group (n = 28).

RESULTS

  The adolescents shared their experiences of adversity and felt empowered by the workshops. Self-reported impairment decreased in the intervention groups.

CONCLUSION

  The protective effect of creative language activities for immigrant and refugee youth should be further investigated.

Antimicrobial resistance survey in a river receiving effluents from freshwater fish farms

AIMS

The aims of this study were: (i) to determine the proportions of Aeromonas spp. resistant to florfenicol (FC), oxolinic acid (OA) and oxytetracycline (OTC) along a river receiving effluents from fish farms, and (ii) to assess the relevance of using this bacterial group as an indicator for studying the consequences of the use and release of these aquacultural antimicrobials in the freshwater environment, as compared with performing antimicrobial measurements in sediments.

METHODS AND RESULTS

Sediment interstitial waters sampled along a river during two distinct climatic seasons were plated on an Aeromonas-selective medium supplemented or not with OA, OTC or FC. The October 2004 campaign showed an enrichment of OA- and OTC-resistant Aeromonas immediately downstream of the fish farms and a wastewater treatment plant. Two fish farms showed similar results in March 2005. In contrast, only 10 FC-resistant Aeromonas strains could be isolated, which revealed that minimum inhibitory concentrations of FC were greater than 64 microg ml(-1) and multiple antimicrobial resistances. Contamination of sediments by antimicrobials was detected but was not always co-localized with resistance peaks or known point sources of contamination.

CONCLUSIONS

Aeromonas could be valuable indicators of OA, OTC and FC resistance in the freshwater environment. Fish farms contribute to the contamination of the river by antimicrobials and resistant bacteria.

SIGNIFICANCE AND IMPACT OF THE STUDY

Considering the still very low proportion of FC-resistant Aeromonas, this study can be considered as a reference for further studies about this recently introduced veterinary antimicrobial agent.

Improving reading and writing learning in underprivileged pluri-ethnic settings

BACKGROUND

Many studies carried out in first language contexts tend to demonstrate the positive effects of activity programmes aimed at (1) developing metaphonological abilities and (2) developing language skills through active story listening on learning to read and to spell by first-grade students.

AIMS

This study seeks to extend previous findings by (a) including children, the majority of whom have French as a second language, who attend plurilingual schools and have not been included in previous studies, and (b) providing training based on three essential principles shared by the two kinds of programmes: integrating activities into realistic literacy practice contexts; encouraging active student participation through tasks which very often require problem solving; and tackling, one after the other, different kinds of operations or strategies.

SAMPLE

Three groups of students were created out a pool of 202 children enrolled in nine first-grade classes in three underprivileged pluri-ethnic schools. The control group was composed of 46 students who received typical, first-grade methods for teaching reading and spelling. Experimental group 1 (DMPA), 91 students, received a training programme aimed at metaphonological abilities development. Experimental group 2 (DLS), 65 students, received a training intended to develop language skills through active story listening and production.

METHOD

The students from the three groups were evaluated at the beginning (metaphonological task I, pre-reading task) and at the end (metaphonological task II, word recognition task, text comprehension task, word spelling task) of their first year in elementary school.

RESULTS

The programme for the development of metaphonological abilities enabled DMPA group students to obtain significantly higher scores than the control group on metaphonological task II and word recognition task. The DMPA group children also did significantly better than the control and the DLS groups on the word spelling task. However, the DLS group, who benefited from language skills development activities, also progressed in that they obtained significantly better results than the control group in the word recognition task. Moreover, at the end of grade one, there was no difference in the scores obtained by the groups on a comprehension questionnaire administered after the reading of the narrative text.

CONCLUSION

The word reading skills of first-grade children in underprivileged pluriethnic settings can be improved through activities aimed at metaphonological abilities development or language skills development by means of active story listening and production. On the other hand, in order to develop word spelling abilities, the development of metaphonological abilities was more effective. Lastly, further research should seek to improve understanding of the absence of effects of either learning programme on narrative text comprehension.

Evidence of the key role of metal-molecule bonding in metal-molecule-metal transport experiments

The transport properties of two oligothiophene derivatives, that differ only by the chemical group coupling to gold, are compared. It is shown that the role of the coupling group in the transport properties can be decoupled from that of the conjugated body of the molecules and that Se is a better electronic coupling group than S. These results are accounted for semiquantitatively within the frame of the scattering theory of transport, using results from ultraviolet photoemission spectroscopy experiments as inputs for the position in energy of the molecular orbitals with respect to the Fermi level of the electrodes.

Determination of oxolinic acid in faeces and urine of turbot (Scophthalmus maximus) by high-performance liquid chromatography using fluorescence detection

A procedure for the determination of oxolinic acid (OA) in faeces and urine of turbot (Scophthalmus maximus), using reversed-phase high-performance liquid chromatography is described. Liquid chromatography was performed on a 5-microm PuroSpher RP-18E cartridge using acetonitrile and 0.001 M aqueous orthophosphoric acid solution as mobile phase, with fluorescence detection. After the addition of an internal standard, oxolinic acid was extracted by using a liquid-liquid extraction procedure. Linearity and precision were checked over the concentration ranges 1.0-1000 microg/g (faeces) and 0.06-10.00 microg/ml (urine). Limits of detection of OA in faeces and urine were 0.20 microg/g and 0.02 microg/ml respectively. Mean extraction recoveries of OA from faeces and urine were 102.0 and 91.6% respectively.

High-performance liquid chromatographic determination of oxolinic acid in the plasma of seabass (Dicentrarchus labrax) anaesthetized with 2-phenoxyethanol

A high-performance liquid chromatographic (HPLC) method for the determination of oxolinic acid (OA) in the plasma of seabass (Dicentrarchus labrax) anaesthetized with 2-phenoxyethanol is described. The samples were extracted and cleaned up by a solid-phase extraction procedure using C18 extraction cartridges. After the eluent was evaporated, the dry residue was dissolved in 1/15 M phosphate buffer. OA was determined by using an isocratic HPLC method with UV detection at 340 nm. Seabass drug-free plasma samples were spiked with OA at 0.2, 1.0, 5.0 and 25.0 microg/ml. Validation of the method showed good precision and accuracy. The mean recovery was 92.2%, with a relative standard deviation lower than 5%. The quantification limit was 0.2 microg/ml. The method was tested on 300 plasma samples of OA-treated seabass.

The perceptual reality of tone chroma in early infancy

It has often been advanced that pitch is a two-dimensional perceptual attribute, its two dimensions being: (1) tone height, a perceptual quality monotonically related to frequency; and (2) tone chroma, a quality shared by tones forming an octave interval. However, given that many musically uneducated adults do not seem to perceive tone chroma, this model is controversial. We investigated the sensitivity of three-month-old infants to tone chroma by means of a behavioral habituation-dishabituation procedure. Infants were presented with two successive melodic sequences of pure tones, the second sequence being a distorted version of the first one. The distortion consisted in shifting the frequency of some of the original tones, through a seventh or a ninth for some infants, through an octave for others. In the former case, infants displayed significant novelty reactions. In the latter case, significant novelty reactions were observed when the two sequences differed in melodic contour, but not when they had the same contour. These results suggest that young infants are sensitive to both tone height and tone chroma, and thus that tone chroma perception does not necessitate some form of musical experience.