68 research outputs found

    Epithelial-Mesenchymal Transition in Cells Expanded In Vitro from Lineage-Traced Adult Human Pancreatic Beta Cells

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    BACKGROUND: In-vitro expansion of functional beta cells from adult human islets is an attractive approach for generating an abundant source of cells for beta-cell replacement therapy of diabetes. Using genetic cell-lineage tracing we have recently shown that beta cells cultured from adult human islets undergo rapid dedifferentiation and proliferate for up to 16 population doublings. These cells have raised interest as potential candidates for redifferentiation into functional insulin-producing cells. Previous work has associated dedifferentiation of cultured epithelial cells with epithelial-mesenchymal transition (EMT), and suggested that EMT generates cells with stem cell properties. Here we investigated the occurrence of EMT in these cultures and assessed their stem cell potential. METHODOLOGY/PRINCIPAL FINDINGS: Using cell-lineage tracing we provide direct evidence for occurrence of EMT in cells originating from beta cells in cultures of adult human islet cells. These cells express multiple mesenchymal markers, as well as markers associated with mesenchymal stem cells (MSC). However, we do not find evidence for the ability of such cells, nor of cells in these cultures derived from a non-beta-cell origin, to significantly differentiate into mesodermal cell types. CONCLUSIONS/SIGNIFICANCE: These findings constitute the first demonstration based on genetic lineage-tracing of EMT in cultured adult primary human cells, and show that EMT does not induce multipotency in cells derived from human beta cells

    Idiopathic sclerosing mesenteritis in paediatrics: Report of a successfully treated case and a review of literature

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    A 6 year old female with symptoms of small bowel obstruction underwent an exploratory laparotomy which revealed widespread evidence of inflammatory fibrotic adhesions involving the jejunal mesentery. In view of persistent growth failure, chronic anaemia, elevated acute phase reactants and imaging evidence of a diffuse progressive inflammatory process, the child was treated with corticosteroids and methotrexate with complete response. The literature on juvenile idiopathic sclerosing mesenteritis has been reviewed

    Serum VEGF levels are related to the presence of pulmonary arterial hypertension in systemic sclerosis

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    <p>Abstract</p> <p>Background</p> <p>The association between systemic sclerosis and pulmonary arterial hypertension (PAH) is well recognized. Vascular endothelial growth factor (VEGF) has been reported to play an important role in pulmonary hypertension. The aim of the present study was to examine the relationship between systolic pulmonary artery pressure, clinical and functional manifestations of the disease and serum VEGF levels in systemic sclerosis.</p> <p>Methods</p> <p>Serum VEGF levels were measured in 40 patients with systemic sclerosis and 13 control subjects. All patients underwent clinical examination, pulmonary function tests and echocardiography.</p> <p>Results</p> <p>Serum VEGF levels were higher in systemic sclerosis patients with sPAP ≥ 35 mmHg than in those with sPAP < 35 mmHg (352 (266, 462 pg/ml)) vs (240 (201, 275 pg/ml)) (p < 0.01), while they did not differ between systemic sclerosis patients with sPAP < 35 mmHg and controls. Serum VEGF levels correlated to systolic pulmonary artery pressure, to diffusing capacity for carbon monoxide and to MRC dyspnea score. In multiple linear regression analysis, serum VEGF levels, MRC dyspnea score, and D<sub>LCO </sub>were independent predictors of systolic pulmonary artery pressure.</p> <p>Conclusion</p> <p>Serum VEGF levels are increased in systemic sclerosis patients with sPAP ≥ 35 mmHg. The correlation between VEGF levels and systolic pulmonary artery pressure may suggest a possible role of VEGF in the pathogenesis of PAH in systemic sclerosis.</p

    A Mouse Stromal Response to Tumor Invasion Predicts Prostate and Breast Cancer Patient Survival

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    Primary and metastatic tumor growth induces host tissue responses that are believed to support tumor progression. Understanding the molecular changes within the tumor microenvironment during tumor progression may therefore be relevant not only for discovering potential therapeutic targets, but also for identifying putative molecular signatures that may improve tumor classification and predict clinical outcome. To selectively address stromal gene expression changes during cancer progression, we performed cDNA microarray analysis of laser-microdissected stromal cells derived from prostate intraepithelial neoplasia (PIN) and invasive cancer in a multistage model of prostate carcinogenesis. Human orthologs of genes identified in the stromal reaction to tumor progression in this mouse model were observed to be expressed in several human cancers, and to cluster prostate and breast cancer patients into groups with statistically different clinical outcomes. Univariate Cox analysis showed that overexpression of these genes is associated with shorter survival and recurrence-free periods. Taken together, our observations provide evidence that the expression signature of the stromal response to tumor invasion in a mouse tumor model can be used to probe human cancer, and to provide a powerful prognostic indicator for some of the most frequent human malignancies

    Effects of rapid urbanisation on the urban thermal environment between 1990 and 2011 in Dhaka Megacity, Bangladesh

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    This study investigates the influence of land-use/land-cover (LULC) change on land surface temperature (LST) in Dhaka Megacity, Bangladesh during a period of rapid urbanisation. LST was derived from Landsat 5 TM scenes captured in 1990, 2000 and 2011 and compared to contemporaneous LULC maps. We compared index-based and linear spectral mixture analysis (LSMA) techniques for modelling LST. LSMA derived biophysical parameters corresponded more strongly to LST than those produced using index-based parameters. Results indicated that vegetation and water surfaces had relatively stable LST but it increased by around 2 °C when these surfaces were converted to built-up areas with extensive impervious surfaces. Knowledge of the expected change in LST when one land-cover is converted to another can inform land planners of the potential impact of future changes and urges the development of better management strategies

    Effect of bivalirudin on aortic valve intervention outcomes study: a two-centre registry study comparing bivalirudin and unfractionated heparin in balloon aortic valvuloplasty

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    We sought to assess if bivalirudin use during balloon aortic valvuloplasty (BAV) would affect clinical outcomes compared with heparin. We compared the outcomes of consecutive patients who underwent elective or urgent BAV with intraprocedural use of bivalirudin or heparin at two high-volume centres. All in-hospital events post BAV were adjudicated by an independent, blinded clinical events committee. Of 427 patients, 223 patients (52.2%) received bivalirudin and 204 (47.8%) received heparin. Compared with patients who received heparin, patients who received bivalirudin had significantly less major bleeding (4.9% vs. 13.2%, p=0.003). Net adverse clinical events (NACE, major bleeding or major adverse cardiovascular events [MACE]) were also reduced (11.2% vs. 20.1%, p=0.01). There was no significant difference in the rates of MACE (mortality, myocardial infarction or stroke, 6.7% vs. 11.3%, p=0.1), or vascular complications (major, 2.7% vs. 2.0%; minor, 4.5% vs. 4.9%; p=0.83). After multivariate analysis controlling for vascular preclosure, the use of bivalirudin remained independently associated with reduced major bleeding (OR 0.37; 95% CI: 0.16 to 0.84; p=0.02) while the association was attenuated in propensity-adjusted analysis (OR 0.44, 95% CI: 0.18 to 1.07, p=0.08). In this registry of patients with severe aortic stenosis, bivalirudin as compared to heparin resulted in improved in-hospital outcomes post BAV in terms of reduced major bleeding, similar MACE and reduced NACE. If verified in a randomised study and extended to the transcatheter aortic valve implantation (TAVI) population, these results might indicate a potential benefit for patients undergoing such procedures
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