8,754 research outputs found

    Long-term survival after intraluminal brachytherapy for inoperable hilar cholangiocarcinoma: A case report

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    Surgical resection with a tumor-free margin is the only curative treatment for hilar cholangiocarcinoma (Klatskin tumor). However, over half of the patients present late with unresectable tumors. Radiotherapy using external beam irradiation or intraluminal brachytherapy (ILBT) has been used to treat unresectable hilar cholangiocarcinoma with satisfactory outcome. We reported a patent with unresectable hilar cholangiocarcinoma surviving more than 6 years after combined external beam irradiation and ILBT. © 2005 The WJG Press and Elsevier Inc. All rights reserved.published_or_final_versio

    Antitumor activity of epidermal growth factor receptor tyrosine kinase inhibitors in human hepatocellular carcinoma cell lines

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    Interactions of a hairy vetch-corn rotation and P fertilizer on the NPK balance in an upland red soil of the Yunnan plateau

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    A field experiment was conducted on an infertile red soil under a hairy vetch (Vicia villosa Roth) and corn (Zea mays L.) rotation system in a highland area of Yunnan Province, China. Effects of phosphate (P) fertilization, combined with hairy vetch returned to the soil, on crop yield and soil fertility were studied, and the balances of nitrogen (N), phosphorus (P) and potassium (K) in the rotation system were estimated. As P application increased from 135 to 315 kg ha-1, the dry matter yield of hairy vetch increased by 900.6 to 1283.86 kg DM ha-1, and also promoted P absorption by hairy vetch. When compared with CK, the corn and corn straw yield increased by 16.64 and 33.48%, respectively, from the crop rotation system, while it increased by 18.36 and 34.96% and 32.58 and 66.5%, from the integrated use of green manure and P fertilizer, respectively. Simple crop rotation proceeding could improve soil N content in the 0 to 20 cm soil layer, while the combined P application improved soil P content. After corn harvest, soil Olsen-P content under the different treatments increased by 35.31 and 122.15% and 19.70 and 63.63% in the 0 to 10 and 10 to 20 cm soil layers, respectively. The optimum P fertilizer rate for the hairy vetch-corn rotation system in Yunnan Province was 135 kg P2O5 ha,sup>-1. At this P rate, the nutrient balance surpluses for N, P and K were 84.9, 18.9 and 26.4%, respectively.Keywords: Rotation system, crop yield, green manure, NPK balance, P fertilizer, soil physical and chemical properties

    Epidemiology of acute primary angle-closure glaucoma in the Hong Kong Chinese population: prospective study.

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    OBJECTIVES: To determine the incidence of acute primary angle-closure glaucoma in the Hong Kong Chinese population, and to identify risk factors for this condition. DESIGN: Prospective study. SETTING: University teaching hospital, Hong Kong. PARTICIPANTS: Patients with acute primary angle-closure glaucoma presenting between 1 March 1998 and 29 February 2000. MAIN OUTCOME MEASURES: Demographic data, presenting symptoms and signs, temporal details of the presentation, and precipitating factors. The crude regional incidence was calculated according to the Hong Kong population census of 1991 and the age-specific incidence was calculated. RESULTS: Seventy-two cases (72 eyes of 72 patients) of acute primary angle-closure glaucoma were recruited. The crude incidence was 10.4 per 100,000 per year in the population aged 30 years and older. Patients at higher risk of attacks were those aged 70 years or older (age-specific incidence, 58.7 per 100,000 per year) and females, who had a relative risk of 3.8 compared with males (95% confidence interval, 1.7-8.4). Only four (5.6%) patients had a positive family history of acute primary angle-closure glaucoma. Seventeen (23.6%) patients were noted to have an upper respiratory tract infection before the attack, and 25 (34.7%) patients had taken antitussive agents. There was a statistically significant inverse correlation between the monthly attack rate and the monthly rate of influenza (Spearman's rank correlation coefficient = -0.388; P=0.031). CONCLUSION: There is a high incidence of acute primary angle-closure glaucoma among Chinese residents of Hong Kong, with elderly females at highest risk. A significant proportion of patients reported upper respiratory tract infection or the use of antitussive medication prior to attacks.published_or_final_versio

    Desensitization of T lymphocyte function by CXCR3 ligands in human hepatocellular carcinoma

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    Aim: Despite the presence of lymphocyte infiltration, human hepatocellular carcinoma (HCC) is typically a rapidly progressive disease. The mechanism of regulation of lymphocyte migration is poorly understood. In this study, we investigated various factors regulating T cell migration in HCC patients. We examined serum CXC chemokine levels in HCC patients and demonstrated the production of CXC chemokines by HCC cell lines. We determined the effect of both HCC patient serum and tumor cell conditioned supernatant upon lymphocyte expression of chemokine receptor CXCR3 as well as lymphocyte migration. Lastly, we examined the chemotactic responses of lymphocytes derived from HCC patients. Methods: The serum chemokines IP-10 (CXCL10) and Mig (CXCL9) levels were measured by cytometric bead array (CBA) and the tumor tissue IP-10 concentration was measured by ELISA. The surface expression of CXCR3 on lymphocytes was determined by flow cytometry. The migratory function of lymphocytes to the corresponding chemokines was assessed using an in vitro chemotactic assay. Phosphorylation of extracellular signal-regulated kinase (ERK) was determined by Western blot analysis. Results: Increased levels of IP-10 and Mig were detected in HCC patient serum and culture supernatants of HCC cell lines. The IP-10 concentration in the tumor was significantly higher than that in the non-involved adjacent liver tissues. HCC cell lines secreted functional chemokines that induced a CXCR3-specific chemotactic response of lymphocytes. Furthermore, tumor-cell-derived chemokines induced initial rapid phosphorylation of lymphocyte ERK followed by later inhibition of ERK phosphorylation. The culture of normal lymphocytes with HCC cell line supernatants or medium containing serum from HCC patients resulted in a significant reduction in the proportion of lymphocytes exhibiting surface expression of CXCR3. The reduction in T cell expression of CXCR3 resulted in reduced migration toward the ligand IP-10, and both CD4 + and CD8 + T cells from HCC patients exhibited diminished chemotactic responses to IP-10 in vitro compared to T cells from healthy control subjects. Conclusion: This study demonstrates functional desensitization of the chemokine receptor CXCR3 in lymphocytes from HCC patients by CXCR3 ligands secreted by tumor cells. This may cause lymphocyte dysfunction and subsequently impaired immune defense against the tumor. © 2005 The WJG Press and Elsevier Inc. All rights reserved.published_or_final_versio

    Global Regulation on microRNA in Hepatitis B Virus-Associated Hepatocellular Carcinoma

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    Recent work has revealed the causative links between deregulation of microRNAs (miRNAs) and cancer development. In hepatocellular carcinoma (HCC), aberrant expression of miRNAs has been observed, but the molecular mechanisms that contribute to such changes remains to be elucidated. Here, we reported the analysis of miRNA expression in 94 pairs of tumor and adjacent nontumor tissues from HBV-associated HCC in Chinese patients. We found miRNAs were aberrantly expressed in HCC tissues. To investigate the cause of such deregulation, we detected changes in DNA copy number by measuring locus-specific hybridization intensity, and found changes in expression of several miRNAs are correlated with genomic amplification or deletion. For example, the genomic regions of miR-30d and miR-151 were amplified in ∼50% of HCC tumor tissues, and the expressions of these miRNAs are significantly correlated with DNA copy number. We also employed cDNA microarray data, and provide evidence that key regulators of the miRNA biosynthetic pathway, including DROSHA, DGCR8, AGO1, and AGO2, are frequently overexpressed in HCC. This study provides molecular clues that may contribute to the global changes of miRNA expression in HCC. Copyright © 2011, Mary Ann Liebert, Inc.published_or_final_versio

    Effect of water vapor on the spallation of thermal barrier coating systems during laboratory cyclic oxidation testing.

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    The effect of water and water vapor on the lifetime of Ni-based superalloy samples coated with a typical thermal barrier coating system—b-(Ni,Pt)Al bond coat and yttria stabilized zirconia (YSZ) top coat deposited by electron beam physical vapor deposition (EB-PVD) was studied. Samples were thermally cycled to 1,150 C and subjected to a water-drop test in order to elucidate the effect of water vapor on thermal barrier coating (TBC) spallation. It was shown that the addition of water promotes spallation of TBC samples after a given number of cycles at 1,150 C. This threshold was found to be equal to 170 cycles for the present system. Systems based on b-NiAl bond coat or on Pt-rich c/c0 bond coat were also sensitive to the water-drop test. Moreover, it was shown that water vapor in ambient air after minutes or hours at room temperature, promotes also TBC spallation once the critical number of cycles has been reached. This desktop spalling (DTS) can be prevented by locking up the cycled samples in a dry atmosphere box. These results for TBC systems confirm and document Smialek’s theory about DTS and moisture induced delayed spalling (MIDS) being the same phenomenon. Finally, the mechanisms implying hydrogen embrittlement or surface tension modifications are discussed

    Evaluation of the fracture performance of different rubberised bitumens based on the essential work of fracture

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    The fracture performance of rubberised bitumen in addition to one pre-treated with a Warm Mix Additive (Sasobit®) was investigated using different test methods measuring different damage mechanisms. Two Recycled Tyre Rubber (RTR) modifiers together with two base binders were blended in the laboratory to produce various combinations of Recycled Tyre Rubber Modified Bitumens (RTR-MBs). The first RTR is a standard recycled polymer derived from discarded truck and passenger car tyres by ambient grinding. The second RTR consists of 100% recycled truck tyres derived by cryogenic grinding and pre-treated with special oil and WMA to allow further decrease of asphalt mixture production temperatures. A fracture mechanics testing approach was used for evaluating the binder fatigue resistance; consisting of the double-edge-notched tension (DENT) test. The critical tip opening displacement (CTOD) obtained from the DENT test was used for fracture characterization of the binders within the ductile failure region. The study applied the partitioning concept of the total energy of bituminous binders to have a more reliable parameter that could be independent of the stress state of the ligament. The results show that generally the addition of RTR improves the fracture properties of binders indicating better fatigue performance. Pre-treatment with Sasobit® makes the materials more brittle and hence more susceptible to fracture

    Phosphodiesterase type 4 expression and anti-proliferative effects in human pulmonary artery smooth muscle cells

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    BACKGROUND: Pulmonary arterial hypertension is a proliferative vascular disease, characterized by aberrant regulation of smooth muscle cell proliferation and apoptosis in distal pulmonary arteries. Prostacyclin (PGI(2)) analogues have anti-proliferative effects on distal human pulmonary artery smooth muscle cells (PASMCs), which are dependent on intracellular cAMP stimulation. We therefore sought to investigate the involvement of the main cAMP-specific enzymes, phosphodiesterase type 4 (PDE4), responsible for cAMP hydrolysis. METHODS: Distal human PASMCs were derived from pulmonary arteries by explant culture (n = 14, passage 3–12). Responses to platelet-derived growth factor-BB (5–10 ng/ml), serum, PGI(2 )analogues (cicaprost, iloprost) and PDE4 inhibitors (roflumilast, rolipram, cilomilast) were determined by measuring cAMP phosphodiesterase activity, intracellular cAMP levels, DNA synthesis, apoptosis (as measured by DNA fragmentation and nuclear condensation) and matrix metalloproteinase-2 and -9 (MMP-2, MMP-9) production. RESULTS: Expression of all four PDE4A-D genes was detected in PASMC isolates. PDE4 contributed to the main proportion (35.9 ± 2.3%, n = 5) of cAMP-specific hydrolytic activity demonstrated in PASMCs, compared to PDE3 (21.5 ± 2.5%), PDE2 (15.8 ± 3.4%) or PDE1 activity (14.5 ± 4.2%). Intracellular cAMP levels were increased by PGI(2 )analogues and further elevated in cells co-treated with roflumilast, rolipram and cilomilast. DNA synthesis was attenuated by 1 μM roflumilast (49 ± 6% inhibition), rolipram (37 ± 6%) and cilomilast (30 ± 4%) and, in the presence of 5 nM cicaprost, these compounds exhibited EC(50 )values of 4.4 (2.6–6.1) nM (Mean and 95% confidence interval), 59 (36–83) nM and 97 (66–130) nM respectively. Roflumilast attenuated cell proliferation and gelatinase (MMP-2 and MMP-9) production and promoted the anti-proliferative effects of PGI(2 )analogues. The cAMP activators iloprost and forskolin also induced apoptosis, whereas roflumilast had no significant effect. CONCLUSION: PDE4 enzymes are expressed in distal human PASMCs and the effects of cAMP-stimulating agents on DNA synthesis, proliferation and MMP production is dependent, at least in part, on PDE4 activity. PDE4 inhibition may provide greater control of cAMP-mediated anti-proliferative effects in human PASMCs and therefore could prove useful as an additional therapy for pulmonary arterial hypertension
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