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The syndecans are transmembrane proteoglycans that place structurally heterogeneous heparan sulfate chains at the cell surface and a highly conserved polypeptide in the cytoplasm. Their versatile heparan sulfate moieties support various processes of molecular recognition, signaling, and trafficking. Here we report the identification of a protein that binds to the cytoplasmic domains of the syndecans in yeast two-hybrid screens, surface plasmon resonance experiments, and ligand-overlay assays. This protein, syntenin, contains a tandem repeat of PDZ domains that reacts with the FYA C-terminal amino acid sequence of the syndecans. Recombinant enhanced green f luorescent protein (eGFP)-syntenin fusion proteins decorate the plasmamembrane and intracellular vesicles, where they colocalize and cosegregate with syndecans. Cells that overexpress eGFP-syntenin show numerous cell surface extensions, suggesting effects of syntenin on cytoskeleton-membrane organization. We propose that syntenin may function as an adaptor that couples syndecans to cytoskeletal proteins or cytosolic downstream signaleffectors.The cell surface heparan sulfate proteoglycans are at the cross-section of several different pathways (1, 2). The heparan sulfate moieties of these molecules bind various differentiation, growth, and scatter factors, facilitate the occupation and activation of the corresponding signal-transducing receptors, and are involved in the internalization and clearance of the signaling complexes from the cell surface (3). They assist receptors that are involved in cell-cell (4) and cell-matrix (5) adhesion and assist scavenging receptors that are involved in the endocytosis and transcytosis of lipoproteins and lipases (6). They also bind and activate serine proteinase inhibitors and accelerate the reactions of these inhibitors with their targets (7). Proteolysis, lipolysis, mesoderm induction, gastrulation, angiogenesis, and neuritogenesis all appear to be regulated by or to depend on heparan sulfate because this glycosaminoglycan is needed for the allosteric activation, approximation, and compartmentalization of the reactants that are engaged in these processes.In most cells syndecans represent the major source of cell surface heparan sulfate. The four known vertebrate syndecans are small type I membrane proteins, with similar and simple domain organizations: a single ectodomain, membrane span, and cytoplasmic domain (1). The ectodomains of the different syndecans have little in common, except for the presence of three or four consensus sites for heparan sulfate attachment near the N termini of the proteins and a dibasic, presumably protease-sensitive site at the junction with the membrane spanning segment. The structures of these ectodomains have not been evolutionary conserved, except again for these shared structural elements. The membrane-spanning and the small cytoplasmic domains of the syndecans, in contrast, show extensive structural similarity (Ϸ60% sequence identity) and have been highly conserved during evolutio...

We found evidence that CT-related radiation exposure increases brain tumor risk. No association was observed for leukemia. Compared with the general population, incidence of brain tumors was higher in the cohort of children with CT scans, requiring cautious interpretation of the findings.

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Primitive malignant renal tumours comprise 6% of all childhood cancers. Wilms tumour (WT) or nephroblastoma is the most frequent type accounting for more than 90%. Imaging alone cannot differentiate between these tumours with certainty but it plays an important role in screening, diagnostic workup, assessment of therapy response, preoperative evaluation and follow-up. The outcome of WT after therapy is excellent with an overall survival around 90%. In tumours such as those where the outcome is extremely good, focus can be shifted to a risk-based stratification to maintain excellent outcome in children with low risk tumours while improving quality of life and decreasing toxicity and costs. This review will discuss the imaging issues for WT from the European perspective and briefly discuss the characteristics of other malignant renal tumours occurring in children and new imaging techniques with potential in this matter.

Wilms tumour is one of the most common malignancies in children, with an excellent prognosis after therapy. There is a very diverse approach to treatment according to geographical location. This variation in therapeutic attitude toward Wilms tumour, particularly between the United States and Europe, has consequences for the choice of imaging modality at diagnosis. In Europe, the International Society of Paediatric Oncology (SIOP) treatment protocol is based on chemotherapy followed by surgery. Imaging (US, CT and MRI), clinical history and examination will help predict whether the findings are consistent with Wilms tumour. Furthermore, in the UK preoperative image-guided biopsy is advised to help identify the small group of patients who, despite typical imaging features of Wilms tumour, have other types of neoplasia that require alternative management. In the United States, the National Wilms Tumor Study (NWTS) advises surgery prior to chemo- and radiotherapy. Hence imaging must provide detailed anatomical information for surgical planning. This article discusses the role of imaging at diagnosis and the relative strengths and weaknesses of the available radiological techniques. We also focus on imaging the lung for metastatic disease and the consequences (to the patient's ultimate outcome) of CT-diagnosed small pulmonary nodules and discuss the radiological diagnosis and consequences of tumour rupture present at diagnosis.

Electronic Doppler flow measurement of portal vein flow is a viable, noninvasive technique that can be used to measure splanchnic blood flow. Values obtained as a result of intensive exercise are in line with earlier results obtained with other techniques.

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