289 research outputs found

    CCL18 synergises with high concentrations of glucose in stimulating fibronectin production in human renal tubuloepithelial cells.

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    Background: Diabetic nephropathy is the leading cause of end stage kidney disease worldwide. The pathogenesis of this disease remains elusive and multiple factors have been implicated. These include the effects of hyperglycaemia, haemodynamic and metabolic factors, and an inflammatory process that stimulates cellular signalling pathways leading to disease progression and severe fibrosis. Fibronectin (Fn) is an important protein of the extracellular matrix that is essential in fibrosis and its presence in increased amounts has been identified in the kidney in diabetic nephropathy. Methods: Proximal tubuloepithelial (HK-2) cells were stimulated with high glucose (30mM D-glucose) or glycated albumin (500μg/mmol) + 4mM D-glucose or their controls, Mannitol (26mM+4mM D-glucose) and 4mM D-glucose, respectively. Following 48 hours of stimulation the supernatant was collected and MTT [3-(4,5-dimethylthiazole-2,5-diphenyltetrazolium bromide] assay performed to assess cell viability. HK-2 cells were also stimulated in the above environments with recombinant CCL18 (rCCL18) or MCP-1 (rMCP-1) for 48 hours with quantification of Fn levels using ELISA. Results: Co-stimulation of HK-2 cells with high concentrations of glucose and rCCL18 significantly increased Fn (p<0.001), in comparison to high concentrations of glucose alone. HK-2 cells stimulated with glycated albumin consistently produced Fn and this did not alter following co-stimulation with rCCL18 or rMCP-1. Conclusion: This study demonstrates how stimulation with a specific chemokine CCL18 in high glucose upregulates the production of Fn from proximal tubuloepithelial cells. This may be relevant to the development of renal fibrosis in diabetic nephropath

    Fine-structure diagnostics of neutral carbon toward HE 0515-4414

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    New high-resolution high signal-to-noise spectra of the z=1.15z=1.15 damped Lyman α\alpha (DLA) system toward the quasi-stellar object HE 0515-4414 reveal absorption lines of the multiplets 2 and 3 in \ion{C}{i}. The resonance lines are seen in two components with total column densities of logN=13.79±0.01\log N=13.79\pm0.01 and logN=13.36±0.01\log N=13.36\pm0.01, respectively. The comparision of theoretical calculations of the relative fine-structure population with the ratios of the observed column densities suggests that the \ion{C}{i} absorbing medium is either very dense or exposed to very intense UV radiation. The upper limit on the local UV energy density is 100 times the galactic UV energy density, while the upper limit on the \ion{H}{i} number density is 110 cm3^{-3}. The excitation temperatures of the ground state fine-structure levels of T=15.7T=15.7 and T=11.1T=11.1 K, respectively, are consistent with the temperature-redshift relation predicted by the standard Friedmann cosmology. The cosmic microwave background radiation (CMBR) is only a minor source of the observed fine-structure excitation.Comment: 5 pages, 5 figures, uses A&A macro package, gzipped tar archive, accepted by A&

    From Classical Genetics to Quantitative Genetics to Systems Biology: Modeling Epistasis

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    Gene expression data has been used in lieu of phenotype in both classical and quantitative genetic settings. These two disciplines have separate approaches to measuring and interpreting epistasis, which is the interaction between alleles at different loci. We propose a framework for estimating and interpreting epistasis from a classical experiment that combines the strengths of each approach. A regression analysis step accommodates the quantitative nature of expression measurements by estimating the effect of gene deletions plus any interaction. Effects are selected by significance such that a reduced model describes each expression trait. We show how the resulting models correspond to specific hierarchical relationships between two regulator genes and a target gene. These relationships are the basic units of genetic pathways and genomic system diagrams. Our approach can be extended to analyze data from a variety of experiments, multiple loci, and multiple environments

    Prognostic Implications of MicroRNA-21 Overexpression in Invasive Ductal Carcinomas of the Breast

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    (miR-21) is known to act as an oncogene. The aim of this study was to investigate the significance of miR-21 expression level in relation with clinicopathological factors and prognosis in breast cancer. Methods: MicroRNA was extracted from cancer and normal breast tissue of 109 breast cancer patients who underwent surgery from 2002 to 2004 using the Taqman ® MicroRNA Assay. The correlation between miR-21 expression and clinicopathologic features was analyzed and the significance of miR-21 as a prognostic factor and its relationship with survival was determined. Results: MiR-21 expression was higher in cancer tissues than in normal tissues (p&lt;0.0001). High miR-21 expression was associated with mastectomy, larger tumor size, higher stage, higher grade, estrogen receptor (ER) negative, human epidermal growth factor receptor 2 (HER2) positive, HER2 positive breast cancer subtype, high Ki-67 expression, and death. On multivariate analysis, prognostic factors for overall survival were ER and miR-21. High miR-21 expression was significantly related to lower overall survival (p = 0.031). Conclusion: This study supports the role of miR-21 as an oncogene and a biomarker for breast cancer with its high expression in cancer tissues and its relationship with other prognostic factors and survival

    Process evaluation of a community-based intervention promoting multiple maternal and neonatal care practices in rural Nepal

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    <p>Abstract</p> <p>Background</p> <p>The challenge of delivering multiple, complex messages to promote maternal and newborn health in the <it>terai </it>region of Nepal was addressed through training Female Community Health Volunteers (FCHVs) to counsel pregnant women and their families using a flipchart and a pictorial booklet that was distributed to clients. The booklet consists of illustrated messages presented on postcard-sized laminated cards that are joined by a ring. Pregnant women were encouraged to discuss booklet content with their families.</p> <p>Methods</p> <p>We examined use of the booklet and factors affecting adoption of practices through semi-structured interviews with district and community-level government health personnel, staff from the Nepal Family Health Program, FCHVs, recently delivered women and their husbands and mothers-in-law.</p> <p>Results</p> <p>The booklet is shared among household members, promotes discussion, and is referred to when questions arise or during emergencies. Booklet cards on danger signs and nutritious foods are particularly well-received. Cards on family planning and certain aspects of birth preparedness generate less interest. Husbands and mothers-in-law control decision-making for maternal and newborn care-seeking and related household-level behaviors.</p> <p>Conclusions</p> <p>Interpersonal peer communication through trusted community-level volunteers is an acceptable primary strategy in Nepal for promotion of household-level behaviors. The content and number of messages should be simplified or streamlined before being scaled-up to minimize intervention complexity and redundant communication.</p

    MicroRNA-21 regulates breast cancer invasion partly by targeting tissue inhibitor of metalloproteinase 3 expression

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    <p>Abstract</p> <p>Background</p> <p>MicroRNAs are non-coding RNA molecules that posttranscriptionally regulate expression of target genes and have been implicated in the progress of cancer proliferation, differentiation and apoptosis. The aim of this study was to determine whether microRNA-21 (miR-21), a specific microRNA implicated in multiple aspects of carcinogenesis, impacts breast cancer invasion by regulating the tissue inhibitor of metalloproteinase 3 (TIMP3) gene.</p> <p>Methods</p> <p>miR-21 expression was investigated in 32 matched breast cancer and normal breast tissues, and in four human breast cancer cell lines, by Taqman quantitative real-time PCR. Cell invasive ability was determined by matrigel invasion assay in vitro, in cells transfected with miR-21 or anti-miR-21 oligonucleotides. In addition, the regulation of tissue inhibitor of metalloproteinase 3 (TIMP3) by miR-21 was evaluated by western blotting and luciferase assays.</p> <p>Results</p> <p>Of the 32 paired samples analyzed, 25 breast cancer tissues displayed overexpression of miR-21 in comparison with matched normal breast epithelium. Additionally, incidence of lymph node metastasis closely correlated with miR-21 expression, suggesting a role for miR-21 in metastasis. Similarly, each of the four breast cancer cell lines analyzed overexpressed miR-21, to varied levels. Further, cells transfected with miR-21 showed significantly increased matrigel invasion compared with control cells, whereas transfection with anti-miR-21 significantly decreased cell invasion. Evaluation of TIMP3 protein levels, a peptidase involved in extarcellular matrix degredation, inversely correlated with miR-21 expression.</p> <p>Conclusion</p> <p>As knockdown of miR-21 increased TIMP3 protein expression and luciferase reporter activity, our data suggests that miR-21 could promote invasion in breast cancer cells via its regulation of TIMP3.</p

    Predictors of early recurrence after resection of colorectal liver metastases

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    BACKGROUND: Early recurrence after resection of colorectal liver metastases (CLM) is common. Patients at risk of early recurrence may be candidates for enhanced preoperative staging and/or earlier postoperative imaging. The aim of this study was to determine if there are any risk factors that specifically predict early liver-only and systemic recurrence. METHODS: Retrospective analysis of prospective database of patients undergoing liver resection (LR) for CLM from 2004 to 2006 was undertaken. Early recurrence was defined as occurring within 18 months of LR. Patients were classified into three groups: early liver-only recurrence, early systemic recurrence and recurrence-free. Preoperative factors were compared between patients with and without early recurrence. RESULTS: Two hundred and forty-three consecutive patients underwent LR for CLM. Twenty-seven patients (11%) developed early liver-only recurrence. Dukes C stage and male sex were significantly associated with early liver-only recurrence (P < 0.05). Sixty-six patients (27%) developed early systemic recurrence. Tumour size ≥3.6 cm and tumour number (>2) were significantly associated with early systemic recurrence (P < 0.001). CONCLUSIONS: It is possible to stratify patients according to the risk of early liver-only or systemic recurrence after resection of CLM. High-risk patients may be candidates for preoperative MRI and/or computed tomography-positron emission tomography (CT-PET) scan and should receive intensive postoperative surveillance

    Structural Differences between the Streptococcus agalactiae Housekeeping and Pilus-Specific Sortases: SrtA and SrtC1

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    The assembly of pili on the cell wall of Gram-positive bacteria requires transpeptidase enzymes called sortases. In Streptococcus agalactiae, the PI-1 pilus island of strain 2603V/R encodes two pilus-specific sortases (SrtC1 and SrtC2) and three pilins (GBS80, GBS52 and GBS104). Although either pilus-specific sortase is sufficient for the polymerization of the major pilin, GBS80, incorporation of the minor pilins GBS52 and GBS104 into the pilus structure requires SrtC1 and SrtC2, respectively. The S. agalactiae housekeeping sortase, SrtA, whose gene is present at a different location and does not catalyze pilus polymerization, was shown to be involved in cell wall anchoring of pilus polymers. To understand the structural basis of sortases involved in such diverse functions, we determined the crystal structures of S. agalactiae SrtC1 and SrtA. Both enzymes are made of an eight-stranded beta-barrel core with variations in their active site architecture. SrtA exhibits a catalytic triad arrangement similar to that in Streptococcus pyogenes SrtA but different from that in Staphylococcus aureus SrtA. In contrast, the SrtC1 enzyme contains an N-terminal helical domain and a ‘lid’ in its putative active site, which is similar to that seen in Streptococcus pneumoniae pilus-specific sortases, although with subtle differences in positioning and composition. To understand the effect of such differences on substrate recognition, we have also determined the crystal structure of a SrtC1 mutant, in which the conserved DP(W/F/Y) motif was replaced with the sorting signal motif of GBS80, IPNTG. By comparing the structures of WT wild type SrtA and SrtC1 and the ‘lid’ mutant of SrtC1, we propose that structural elements within the active site and the lid may be important for defining the role of specific sortase in pili biogenesis

    Mapping Genetic Diversity of Cherimoya (Annona cherimola Mill.): Application of Spatial Analysis for Conservation and Use of Plant Genetic Resources

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    There is a growing call for inventories that evaluate geographic patterns in diversity of plant genetic resources maintained on farm and in species' natural populations in order to enhance their use and conservation. Such evaluations are relevant for useful tropical and subtropical tree species, as many of these species are still undomesticated, or in incipient stages of domestication and local populations can offer yet-unknown traits of high value to further domestication. For many outcrossing species, such as most trees, inbreeding depression can be an issue, and genetic diversity is important to sustain local production. Diversity is also crucial for species to adapt to environmental changes. This paper explores the possibilities of incorporating molecular marker data into Geographic Information Systems (GIS) to allow visualization and better understanding of spatial patterns of genetic diversity as a key input to optimize conservation and use of plant genetic resources, based on a case study of cherimoya (Annona cherimola Mill.), a Neotropical fruit tree species. We present spatial analyses to (1) improve the understanding of spatial distribution of genetic diversity of cherimoya natural stands and cultivated trees in Ecuador, Bolivia and Peru based on microsatellite molecular markers (SSRs); and (2) formulate optimal conservation strategies by revealing priority areas for in situ conservation, and identifying existing diversity gaps in ex situ collections. We found high levels of allelic richness, locally common alleles and expected heterozygosity in cherimoya's putative centre of origin, southern Ecuador and northern Peru, whereas levels of diversity in southern Peru and especially in Bolivia were significantly lower. The application of GIS on a large microsatellite dataset allows a more detailed prioritization of areas for in situ conservation and targeted collection across the Andean distribution range of cherimoya than previous studies could do, i.e. at province and department level in Ecuador and Peru, respectively
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