928 research outputs found

    Decreased expression of the Id3 gene at 1p36.1 in ovarian adenocarcinomas

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    The molecular events that drive the initiation and progression of ovarian adenocarcinoma are not well defined. We have investigated changes in gene expression in ovarian cancer cell lines compared to an immortalized human ovarian surface epithelial cell line (HOSE) using a cDNA array. We identified 17 genes that were under-expressed and 10 genes that were over-expressed in the cell lines compared to the HOSE cells. One of the genes under-expressed in the ovarian cancer cell lines, Id3, a transcriptional inactivator, was selected for further investigation. Id3 mRNA was expressed at reduced levels in 6 out of 9 ovarian cancer cell lines compared to the HOSE cells while at the protein level, all 7 ovarian cancer cell lines examined expressed the Id3 protein at greatly reduced levels. Expression of Id3 mRNA was also examined in primary ovarian tumours and was found in only 12/38 (32%) cases. A search was conducted for mutations of Id3 in primary ovarian cancers using single stranded conformation polymorphism (SSCP) analysis. Only one nucleotide substitution, present also in the corresponding constitutional DNA, was found in 94 ovarian tumours. Furthermore no association was found between LOH at 1p36 and lack of expression of Id3. These data suggest that Id3 is not the target of LOH at 1p36. © 2001 Cancer Research Campaign http://www.bjcancer.co

    Expansion of the ligand knowledge base for chelating P,P-donor ligands (LKB-PP)

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    [Image: see text] We have expanded the ligand knowledge base for bidentate P,P- and P,N-donor ligands (LKB-PP, Organometallics2008, 27, 1372–1383) by 208 ligands and introduced an additional steric descriptor (nHe(8)). This expanded knowledge base now captures information on 334 bidentate ligands and has been processed with principal component analysis (PCA) of the descriptors to produce a detailed map of bidentate ligand space, which better captures ligand variation and has been used for the analysis of ligand properties

    Antigenicity of Recombinant Maltose Binding Protein-Mycobacterium avium subsp. paratuberculosis Fusion Proteins with and without Factor Xa Cleaving

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    Mycobacterium avium subsp. paratuberculosis causes Johne’s disease (JD) in ruminants. Proteomic studies have shown that M. avium subsp. paratuberculosis expresses certain proteins when exposed to in vitro physiological stress conditions similar to the conditions experienced within a host during natural infection. Such proteins are hypothesized to be ex- pressed in vivo, are recognized by the host immune system, and may be of potential use in the diagnosis of JD. In this study, 50 recombinant maltose binding protein (MBP)-M. avium subsp. paratuberculosis fusion proteins were evaluated using serum samples from sheep infected with M. avium subsp. paratuberculosis, and 29 (58%) were found to be antigenic. Among 50 fusion proteins, 10 were evaluated in MBP fusion and factor Xa-cleaved forms. A total of 31 proteins (62%) were found to be antigenic in either MBP fusion or factor Xa-cleaved forms. Antigenicity after cleavage and removal of the MBP tag was marginally enhanced

    Increasing chromosome 1 copy number parallels histological progression in breast carcinogenesis

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    Chromosome 1 copy number in the benign breast lesions hyperplasia and atypical duct hyperplasia (ADH) was investigated using fluorescence in situ hybridization on paraffin sections. Progression of chromosome 1 changes occurring in parallel with histological progression from normal through hyperplasia and ADH to ductal carcinoma in situ (DCIS) and invasive carcinoma was also assessed, both overall and within individual patients. The mean signal number for normal cells was 1.14, while that for hyperplasia was 1.56 and ADH was 1.5, while values for DCIS of 1.95 and invasive duct carcinoma of 1.79, were higher (P< 0.001). Six of the seven cases also showed a significant trend towards an increasing proportion of cells with greater than 2 signals per nucleus occurring with histological progression (P< 0.001). These results support the concept that benign proliferative breast disease is a biological precursor of in-situ and invasive ductal carcinoma, the early histological changes possibly indicating a field effect with further genetic changes required for the development of a malignant phenotype. © 2000 Cancer Research Campaig

    Biogeographical patterns and environmental controls of phytoplankton communities from contrasting hydrographical zones of the Labrador Sea

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    The Labrador Sea is an important oceanic sink for atmospheric CO2 because of intensive convective mixing during winter and extensive phytoplankton blooms that occur during spring and summer. Therefore, a broad-scale investigation of the responses of phytoplankton community composition to environmental forcing is essential for understanding planktonic food-web organisation and biogeochemical functioning in the Labrador Sea. Here, we investigated the phytoplankton community structure (>4 μm) from near surface blooms (1.2 mg chla m−3) occurred on and near the shelves in May and in offshore waters of the central Labrador Sea in June due to haline- and thermal-stratification, respectively. Sea ice-related (Fragilariopsis cylindrus and F. oceanica) and Arctic diatoms (Fossula arctica, Bacterosira bathyomphala and Thalassiosira hyalina) dominated the relatively cold (<0 °C) and fresh (salinity < 33) waters over the Labrador shelf (e.g., on the southwestern side of the Labrador Sea), where sea-ice melt and Arctic outflow predominates. On the northeastern side of the Labrador Sea, intense blooms of the colonial prymnesiophyte Phaeocystis pouchetii and diatoms, such as Thalassiosira nordenskioeldii, Pseudo-nitzschia granii and Chaetoceros socialis, occurred in the lower nutrient waters (nitrate < 3.6 μM) of the West Greenland Current. The central Labrador Sea bloom occurred later in the season (June) and was dominated by Atlantic diatoms, such as Ephemera planamembranacea and Fragilariopsis atlantica. The data presented here demonstrate that the Labrador Sea spring and early summer blooms are composed of contrasting phytoplankton communities, for which taxonomic segregation appears to be controlled by the physical and biogeochemical characteristics of the dominant water masses

    Does shear wave ultrasound independently predict axillary lymph node metastasis in women with invasive breast cancer?

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    Shear wave elastography (SWE) shows promise as an adjunct to greyscale ultrasound examination in assessing breast masses. In breast cancer, higher lesion stiffness on SWE has been shown to be associated with features of poor prognosis. The purpose of this study was to assess whether lesion stiffness at SWE is an independent predictor of lymph node involvement. Patients with invasive breast cancer treated by primary surgery, who had undergone SWE examination were eligible. Data were retrospectively analysed from 396 consecutive patients. The mean stiffness values were obtained using the Aixplorer(®) ultrasound machine from SuperSonic Imagine Ltd. Measurements were taken from a region of interest positioned over the stiffest part of the abnormality. The average of the mean stiffness value obtained from each of two orthogonal image planes was used for analysis. Associations between lymph node involvement and mean lesion stiffness, invasive cancer size, histologic grade, tumour type, ER expression, HER-2 status and vascular invasion were assessed using univariate and multivariate logistic regression. At univariate analysis, invasive size, histologic grade, HER-2 status, vascular invasion, tumour type and mean stiffness were significantly associated with nodal involvement. Nodal involvement rates ranged from 7 % for tumours with mean stiffness <50 kPa to 41 % for tumours with a mean stiffness of >150 kPa. At multivariate analysis, invasive size, tumour type, vascular invasion, and mean stiffness maintained independent significance. Mean stiffness at SWE is an independent predictor of lymph node metastasis and thus can confer prognostic information additional to that provided by conventional preoperative tumour assessment and staging
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