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Acta Endoscopica - L’hémorragie iatrogène en endoscopie digestive reste pour l’essentiel l’apanage des techniques de résection tumorale et de la... 相似文献
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Ramón Rodrigo Hernán Prat Walter Passalacqua Julia Araya Cristián Guichard Jean P B?chler 《Hypertension research》2007,30(12):1159-1167
This study investigated the association of blood pressure with blood oxidative stress-related parameters in normotensive and hypertensive subjects. A cross-sectional design was applied to 31 hypertensive patients and 35 healthy normotensive subjects. All subjects were men between the ages of 35 and 60 years. Exclusion criteria were obesity, dyslipidemia, diabetes mellitus, smoking and current use of any medication. All patients underwent 24-h ambulatory blood pressure monitoring and sampling of blood and urine. Antioxidant enzymes activity, reduced/oxidized glutathione ratio (GSH/GSSG), and lipid peroxidation (malondialdehyde) were determined in erythrocytes. Parameters measured in the plasma of test subjects were plasma antioxidant status, lipid peroxidation (8-isoprostane), plasma vitamin C and E, and the blood pressure modulators renin, aldosterone, endothelin-1 and homocysteine. Daytime systolic and diastolic blood pressures of hypertensives were negatively correlated with plasma antioxidant capacity (r=-0.46, p<0.009 and r=-0.48, p<0.007), plasma vitamin C levels (r=-0.53, p<0.003 and r=-0.44, p<0.02), erythrocyte activity of antioxidant enzymes, and erythrocyte GSH/GSSG ratio, with hypertensives showing higher levels of oxidative stress. Blood pressures showed a positive correlation with both plasma and urine 8-isoprostane. Neither plasma vitamin E nor the assessed blood pressure modulator levels showed significant differences between the groups or correlation with blood pressures. These findings demonstrate a strong association between blood pressure and some oxidative stress-related parameters and suggest a possible role of oxidative stress in the pathophysiology of essential hypertension. 相似文献
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Papillary carcinoma of the thyroid: hepatocyte growth factor (HGF) stimulates tumor cells to release chemokines active in recruiting dendritic cells 总被引:8,自引:0,他引:8 下载免费PDF全文
Scarpino S Stoppacciaro A Ballerini F Marchesi M Prat M Stella MC Sozzani S Allavena P Mantovani A Ruco LP 《The American journal of pathology》2000,156(3):831-837
Tissue distribution of dendritic cells was investigated in eight cases of papillary carcinoma of the thyroid using immunohistochemistry. Most dendritic cells had an immature phenotype (CD1a++, CD11c+, CD40+, CD86-, HLA-DR-) and were located at the invasion edge of the tumor. This pattern of distribution was profoundly different from that of CD68+ macrophages, which were evenly distributed throughout the tumor. The ability of tumor cells to release chemotactic factors active on dendritic cells was investigated in primary cultures of the same cases of papillary carcinoma, and was compared to that of the corresponding normal thyroid cells obtained from the tumor-free contralateral lobe. Chemotactic activity of culture supernatants was tested against dendritic cells in a chemotaxis chamber. It was found that papillary carcinoma cells were active in releasing chemotactic activity, that hepatocyte growth factor (HGF; 100 ng/ml) or interleukin (IL)-1beta (10(3) U/ml) induced a fourfold increase in the amount of chemotactic activity released, and that normal thyroid cells obtained from the same patients were as effective as tumor cells. Characterization of chemokines at RNA level revealed that unstimulated cells contain large amounts of IL-8 and monocyte chemotactic protein (MCP)-1 RNAs, and that stimulation with HGF or IL-1beta induced RNAs for regulated upon activation normal T expressed and secreted (RANTES), macrophage inflammatory protein (MIP)-3alpha, interferon-gamma-inducible protein 10 (IP-10), and, to a lesser extent, MIP-1alpha and MIP-1beta. The possibility that HGF/Met interaction has a biological role in vivo was investigated in serial sections of six tumors immunostained for CD1a+, Met protein, and HGF. It was found that all six tumors were intensely and diffusely positive for Met protein, that HGF staining was present in tumor cells of the advancing edge, and that HGF+/Met+ tumor cell nests were infiltrated by CD1a+ dendritic cells. The foregoing observations are consistent with the possibility that HGF stimulation of Met+ tumor cells is one of the molecular mechanisms involved in the recruitment of dendritic cells. 相似文献
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L. Prat G. Torres I. Carrió M. Roca V. Riambau L. Berná M. Estorch I. Ferrer C. Garcia 《European journal of nuclear medicine and molecular imaging》1993,20(12):1141-1145
To test iodine-125 labelled low-density lipoprotein (125I-LDL), polyclonal indium-111 labelled immunoglobulin G (111In-IgG) and iodine-125 labelled endothelin-1 uptake in metabolically active atheromatous plaques after arterial wall injury, we performed balloon de-endothelialization of carotid arteries or abdominal aortas in 24 New Zealand male rabbits which were fed with a normal diet (n=14) or a hypercholesterolaemic diet (n=10) after surgery. Six weeks later the animals were injected with 200 Ci of (125I-LDL), and/or with 100 Ci of 111In-IgG or with 9 Ci of 125I-endothelin-1. Forty-eight hours later the animals were sacrificed. Carotid arteries and aortas were removed, counted and fixed for autoradiography and light microscopy examination. Contralateral carotid arteries and thoracic aortas served as controls.Significant 111In-IgG uptake was observed in the injured arteries at autoradiography, with localization mainly in the healing edges, and at well counting. The percentage of the injected dose per gram (%D.inj/g) was 0.0188±0.06 versus 0.0059±0.003 in controls (P< 0.05). There was no difference in 111In-IgG uptake between arteries with injury alone and those with active atheroma formation at the site of the injury. Significant (125I-LDL), uptake was observed only when lipid deposition was present at light microscopy (%D.inj/g of 0.0024±0.0005 vs 0.0010±0.0003 in controls, P < 0.05). 125I-endothelin-1 accumulation was observed in four of five injured aortas both at autoradiography, with diffuse localization, and at well counting (%D.inj/g of 0.0012±0.0004 in the abdominal aortas vs 0.0008±0.0003 in the thoracic aortas).Polyclonal IgG may accumulate in injured arteries without active atheroma formation. Inflammatory reaction at the site of the injury may cause 111In-IgG uptake independently of atheromatous plaque formation. LDL accumulation takes place only with active atheroma formation at the site of the injury. Use of labelled peptides such as endothelin-1 may provide further insight into the mechanisms of atheromatous plaque formation. 相似文献
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Prat A Biernacki K Pouly S Nalbantoglu J Couture R Antel JP 《Journal of neuropathology and experimental neurology》2000,59(10):896-906
The kinin B1 receptor is an inducible receptor expressed in response to inflammatory mediators. We sought to determine whether kinin B1 receptor can be expressed on human brain endothelial cells (HBECs) in vitro and whether signaling via this receptor can regulate permeability and chemokine production properties of these cells. Multiplex RT-PCR amplification and western blot techniques were used to evaluate B1 receptor expression by HBECs. Although B1 receptor mRNA and protein could not be detected on resting HBECs, interferon-gamma induced a dose- and time-dependent up-regulation of B1 receptor mRNA and protein on HBECs. Stimulation of interferon-gamma-treated HBECs with the selective B1 agonist R-838 (Sar [D-Phe8] des Arg9-BK) induced a dose- and time-dependent increase in the production of inositol 3,4,5 tri-phosphate and nitric oxide. Permeability of the HBECs monolayer, as measured by BSA diffusion, was significantly increased by application of the B1 agonist. This biological effect of R-838 could be prevented by R-715, a B1 receptor antagonist and by L-NAME, a nitric oxide synthase blocker. R-838 also inhibited interleukin-8 release from HBECs. We demonstrate that B1 receptors can be up regulated on the surface of HBECs by molecules released during inflammatory response and that signaling via this receptor can regulate BBB permeability and chemokine production in vitro. 相似文献
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