Phosphorylation of Notch proteins has been indirectly correlated with Notch activation and nuclear translocation as well as cellular transformation. There is evidence that the Wnt signaling pathway, which results in glycogen synthase kinase-3␤ (GSK-3␤) inhibition, cross-talks with the Notch pathway. In this study, we show that GSK-3␤ is able to bind and phosphorylate Notch2 in vitro and in vivo. We identify three specific phosphorylation sites in the Notch2 serine/threoninerich domain that are dependent on GSK-3␤ activity. Phosphorylation of the serine/threonine-rich domain has been shown previously to be crucial in regulating cytokine-specific cell differentiation. Coimmunoprecipitation experiments show that full-length Notch2 binds more efficiently than intracellular Notch2 to GSK-3␤. Nevertheless, only the processed Notch2 is a substrate for the kinase, thus suggesting that GSK-

AimTo describe the opinions of hospital physicians concerning problems regarding the spontaneous reporting of adverse drug reactions (ADRs) and ways to solve them. MethodsA qualitative study was carried out. Fifteen focus groups were conducted among physicians working in a tertiary teaching hospital. A total of 208 physicians from different medical specialities participated. The focus group discussions were recorded by three different observers and the transcripts of each session were analysed for issues and themes emerging from the text. ResultsFour types of obstacles to spontaneous reporting were considered particularly important: (i) problems with the ADRs diagnosis; (ii) problems with the usual workload and lack of time; (iii) problems related to the organization and activities of the pharmacovigilance system; (iv) and problems related to potential conflicts. The potential solutions suggested for improving spontaneous repor ting were to define the kind of ADRs which should be reported, to facilitate an easy contact and quick access to the hospital pharmacovigilance system, to facilitate information and support for reporting and feedback of pharmacovigilance activities. ConclusionsThe perception of the different obstacles by the hospital physicians is an impor tant factor in determining the causes of the underreporting of ADRs and addressing these obstacles could lead to an improvement in spontaneous repor ting. A closer relationship between the doctors and the pharmacovigilance centre is suggested as a means of solving these problems. More information is needed to improve the spontaneous reporting of ADRs in specialized healthcare.

The NF-B pathway plays a pivotal role in proliferation, differentiation, apoptosis, and immune responses in mammals. The NF-B inhibitor, IB, has classically been characterized for its ability to sequester NF-B transcription factors in the cytoplasm. Nevertheless, a nuclear fraction of IB␣ has consistently been detected and associated with repression of nuclear NF-B. Now we show that IB␣ physically associates with different repression elements such as nuclear corepressors and histone acetyltransferases and deacetylases (HDACs). More remarkably, chromatin immunoprecipitation experiments demonstrate that IB␣ is recruited to the promoter regions of the Notch-target gene, hes1, together with HDAC1 and -5, whereas we did not detect IB␣ associated with classical NF-B target genes such as IL6 and RANTES. TNF-␣ treatment results in a temporary release of IB␣ from the hes1 promoter that correlates with increased histone acetylation and transcriptional activation. In addition, we demonstrate that both IB kinase-␣ and -␤ are simultaneously recruited to the hes1 promoter in response to TNF-␣, coinciding with a maximum of IB␣ release and gene activation. Moreover, TNF-␣-dependent histone H3 acetylation, release of IB␣ from the hes1 promoter, and hes1 mRNA synthesis are affected in IKK-␣ ؊/؊ mouse embryonic fibroblasts. We propose that IB␣ plays a previously undescribed role in regulating the recruitment of repression elements to specific promoters. Recruitment of IKKs to the nucleus in response to TNF-␣ may induce chromatin-associated IB␣ release and gene activation. These findings provide additional insight in the cross-talk between NF-B and other signaling pathways.IB kinase ͉ NF-B ͉ chromatin ͉ TNF-␣