One of the most consistently deleted chromosomal regions in solid tumours is 11q23 ± q25, which consequently has been postulated to harbour one or more tumour suppressor loci. Despite large eorts to identify the responsible genes, the goal remains elusive, but as knowledge accumulates new candidates are emerging. The present study was undertaken in an attempt to assess the possible implication of four genes residing at 11q23 ± q24, in a population of early onset breast cancer (n=41). The coding sequence of PIG8, CHK1, LOH11CR2A and PPP2R1B were screened for mutations using the protein truncation test or single-strand conformational polymorphism, in combination with direct DNA sequencing. Varying proportions of alterations were detected, ranging from 6% in PPP2R1B to 39% in PIG8. Many of these changes were deletions, in some cases corresponding to complete exons, thus likely to represent splice variants, while others were presumed to arise from aberrant splicing, since they occurred at sites with resemblance to exon/intron borders. Considering only bona ®de mutations, the highest alteration frequency (17%) was again found in PIG8. Most of these alterations were likely to have an adverse impact on the translated protein as they either altered the reading frame or aected phylogenetically conserved residues. Our data represent the ®rst evidence of alterations in the PIG8 gene in human malignancies, a ®nding that substantiates its role as a potential tumour suppressor gene as suggested by its involvement in p53-induced apoptosis. Oncogene (2001) 20, 7753 ± 7760.

One of the main purposes of our investigation has been the development of new image processing methods, which allow a definite and precise tracking of the borderline of the ventricle in 2-dimensional echocardiograms. We report on our experience with two new methods, which are based on the grey-level rise (GL) and the signal-to-noise ratio (SNR) in combined heart phase triggered image series and present a quantitative comparison of these time-series methods with the interpretation of 0 a single native image (non-contrast image) (NCI) a single contrast-material image (CMI) the corresponding subtraction image (SUB) the corresponding color superposition image (CS).The comparison is based on the calculation of the ejection fraction using the above mentioned methods and contains inter-observer variability and intra-observer variability.