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Onderzoek naar het effect van een kortdurende opname tijdens het winterseizoen in het Astmacentrum Davos bij kinderen met ernstig allergisch astma.

Insulin-like growth factor-1 receptor (IGF1R) is a tyrosine kinase receptor mediating cell growth and survival of cancer cells. We studied responses to IGF1R tyrosine kinase inhibitor NVP-AEW541 combined with conventional systemic drugs in breast cancer cell lines of different clinical subtype.Sensitivity to NVP-AEW541, single treatment and combinations with tamoxifen, trastuzumab, doxorubicin or paclitaxel, was tested in MCF7, SKBR3 and T47D cells. Cells were assayed for proliferation, cell death, cell cycle distribution and phosphorylation of proteins downstream of IGF1R.Treatment of NVP-AEW541 resulted in reduced proliferation, G-1 cell cycle arrest and reduced phosphorylation of protein kinase B (AKT) and extracellular-signal-regulated protein kinase (ERK). Sensitivity to IGF1R tyrosine kinase inhibition was low in T47D cells, despite their high IGF1R expression. NVP-AEW541 combined with trastuzumab had synergistic cytotoxic effects in T47D cells, and additive effects were shown in MCF7 and SKBR3 cells. Also, combination with doxorubicin had antagonistic effects in T47D cells. Doxorubicin caused up-regulation of phosphorylated ERK in T47D cells, which was not inhibited by NVP-AEW541.Antagonistic effects should be anticipated when IGF1R inhibitors are combined with conventional systemic drugs in a subset of breast tumors. Development of functional biomarkers predicting tumor response to tailored IGF1R therapy is warranted.

During the baseline period of a clinical trial comparing different dosage schedules of inhaled steroids, asthmatic children (aged 6-10 years) were expected to meet the inclusion criterion of airways hyper-responsiveness (PD(20) methacholine80 micro g) after withdrawal of inhaled corticosteroids for 2-8 weeks. However, many children failed to do so.It has been shown that young wheezing children may outgrow their symptoms. We investigated if differences between children with and without airways hyper-responsiveness after withdrawal of inhaled corticosteroids were compatible with differences between transient and persistent wheezers found in other studies.Seventy-eight children entered the study, of which 41 developed airways hyper- responsiveness after withdrawal of inhaled corticosteroids, and 37 did not. These two groups of children were compared with respect to differences in demographic, clinical, and immunological features (IL-4, IL-5, IL-10, and IFN-gamma produced by Con A stimulated peripheral mononuclear cells (PBMCs) and serum IL-4, IL-5 and soluble intercellular adhesion molecule-1 (sICAM-1)).Hyper-responsive children had more atopic features (positive RAST, high IgE, eczema), lower levels of FEV1 and lower concentrations of sICAM-1 than non-hyper-responsive children. Apart from a borderline significantly higher IL-4 production in the hyper-responsive group, other immunologic parameters were comparable. Multivariate logistic regression analysis showed that high serum IgE, low FEV1, and low sICAM-1 levels were independently associated with the presence of airways hyper-responsiveness after stopping inhaled corticosteroids. Atopy was associated with higher concentrations of IL-4 in the hyper-responsive group.After withdrawal of inhaled corticosteroids many children previously diagnosed with asthma did not develop airways hyper-responsiveness. We conclude that hyper-responsive children share features with persistent wheezers as found in previous studies, whereas the non-hyper- responsive children may represent transient wheezers.