40 research outputs found

    A Useful Form of the Abel Bound and Its Application to Estimator Threshold Prediction

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    International audienceThis correspondence investigates the Abel bound in order to predict the estimators mean square error (mse) threshold effect. A tractable and computationally efficient form of this bound is derived. This form combines the Chapman–Robbins and the Cramér–Rao bounds. This bound is applied to a data-aided carrier frequency estimation problem for which a closed-form expression is provided. An indicator of the signal-to-noise ratio threshold is proposed. A comparison with recent results on the Barankin bound (Chapman–Robbins version) shows the superiority of the Abel-bound version to predict the mse threshold without increasing the computational complexity

    Antibacterial Properties of Mesoporous Silica Nanoparticles Modified with Fluoroquinolones and Copper or Silver Species

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    Antibiotic resistance is a global problem and bacterial biofilms contribute to its development. In this context, this study aimed to perform the synthesis and characterization of seven materials based on silica mesoporous nanoparticles functionalized with three types of fluoroquinolones, along with Cu2+ or Ag+ species to evaluate the antibacterial properties against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa, including clinical and multi-drug-resistant strains of S. aureus and P. aeruginosa. In addition, in order to obtain an effective material to promote wound healing, a well-known proliferative agent, phenytoin sodium, was adsorbed onto one of the silver-functionalized materials. Furthermore, biofilm studies and the generation of reactive oxygen species (ROS) were also carried out to determine the antibacterial potential of the synthesized materials. In this sense, the Cu2+ materials showed antibacterial activity against S. aureus and E. coli, potentially due to increased ROS generation (up to 3 times), whereas the Ag+ materials exhibited a broader spectrum of activity, even inhibiting clinical strains of MRSA and P. aeruginosa. In particular, the Ag+ material with phenytoin sodium showed the ability to reduce biofilm development by up to 55% and inhibit bacterial growth in a “wound-like medium” by up to 89.33%.We gratefully acknowledge funding from the research project RTI2018-094322-B-I00 financed by MCIN/AEI/10.13039/501100011033/ and “ERDF A way of making Europe”, the Research Thematic Network RED2022-134091-T financed by MCIN/AEI/10.13039/501100011033, the University of the Basque Country UPV/EHU (GIC18/143) and (GIU20/028) and the Gobierno Vasco/Eusko Jaurlaritza (IT1755-22)

    TMPRSS4 regulates levels of integrin α5 in NSCLC through miR-205 activity to promote metastasis

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    TMPRSS4 is a membrane-anchored protease involved in cell migration and invasion in different cancer types including lung cancer. TMPRSS4 expression is increased in NSCLC and its inhibition through shRNA reduces lung metastasis. However, molecular mechanisms leading to the protumorigenic regulation of TMPRSS4 in lung cancer are unknown. METHODS: miR-205 was identified as an overexpressed gene upon TMPRSS4 downregulation through microarray analysis. Cell migration and invasion assays and in vivo lung primary tumour and metastasis models were used for functional analysis of miR-205 overexpression in H2170 and H441 cell lines. Luciferase assays were used to identify a new miR-205 direct target in NSCLC. RESULTS: miR-205 overexpression promoted an epithelial phenotype with increased E-cadherin and reduced fibronectin. Furthermore, miR-205 expression caused a G0/G1 cell cycle arrest and inhibition of cell growth, migration, attachment to fibronectin, primary tumour growth and metastasis formation in vivo. Integrin α5 (a proinvasive protein) was identified as a new miR-205 direct target in NSCLC. Integrin α5 downregulation in lung cancer cells resulted in complete abrogation of cell migration, a decreased capacity to adhere to fibronectin and reduced in vivo tumour growth, compared with control cells. TMPRSS4 silencing resulted in a concomitant reduction of integrin α5 levels. CONCLUSION: We have demonstrated for the first time a new molecular pathway that connects TMPRSS4 and integrin α5 through miR-205 to regulate cancer cell invasion and metastasis. Our results will help designing new therapeutic strategies to inhibit this novel pathway in NSCLC

    Effect of resveratrol on alcohol-induced mortality and liver lesions in mice

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    BACKGROUND: Resveratrol is a polyphenol with important antiinflammatory and antioxidant properties. We investigated the effect of resveratrol on alcohol-induced mortality and liver lesions in mice. METHODS: Mice were randomly distributed into four groups (control, resveratrol-treated control, alcohol and resveratrol-treated alcohol). Chronic alcohol intoxication was induced by progressively administering alcohol in drinking water up to 40% v/v. The mice administered resveratrol received 10 mg/ml in drinking water. The animals had free access to standard diet. Blood levels were determined for transaminases, IL-1 and TNF-α. A histological evaluation was made of liver damage, and survival among the animals was recorded. RESULTS: Transaminase concentration was significantly higher in the alcohol group than in the rest of the groups (p < 0.05). IL-1 levels were significantly reduced in the alcohol plus resveratrol group compared with the alcohol group (p < 0.05). TNF-α was not detected in any group. Histologically, the liver lesions were more severe in the alcohol group, though no significant differences between groups were observed. Mortality in the alcohol group was 78% in the seventh week, versus 22% in the alcohol plus resveratrol group (p < 0.001). All mice in the alcohol group died before the ninth week. CONCLUSION: The results obtained suggest that resveratrol reduces mortality and liver damage in mice

    Resveratrol inhibits nonalcoholic fatty liver disease in rats

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    <p>Abstract</p> <p>Background</p> <p>The prevalence of nonalcoholic fatty liver disease (NAFLD) is high. NAFLD is linked to obesity, diabetes mellitus, and hypertriglyceridemia. Approximately 20% of patients with NAFLD will eventually develop cirrhosis. Our purpose was to investigate whether resveratrol decreased hepatic steatosis in an animal model of steatosis, and whether this therapeutic approach resulted in a decrease in tumor necrosis factor α (TNF-α) production, lipid peroxidation and oxidative stress.</p> <p>Methods</p> <p>Male Wistar CRL: Wi (Han) (225 g) rats were randomized into three groups. A control group (n = 12) was given free access to regular dry rat chow for 4 weeks. The steatosis (n = 12) and resveratrol (n = 12) groups were given free access to feed (a high carbohydrate-fat free modified diet) and water 4 days per week, and fasted for the remaining 3 days for 4 weeks. Rats in the resveratrol group were given resveratrol 10 mg daily by the oral route. All rats were killed at 4 weeks and assessed for fatty infiltration and bacterial translocation. Levels of TNF-α in serum, hepatic malondialdehyde (MDA), oxidative stress (superoxide dismutase, glutathione peroxidase, catalase and nitric oxide synthase) and biochemical parameters were measured.</p> <p>Results</p> <p>Fat deposition was decreased in the resveratrol group as compared to the steatosis group (Grade 1 vs Grade 3, P < 0.05). TNF-α and MDA levels were significantly increased in the steatosis group (TNF-α; 33.4 ± 5.2 vs 26.24 ± 3.47 pg/ml and MDA; 9.08 ± 0.8 vs 3.17 ± 1.45 μM respectively, <it>P </it>< 0.05). This was accompanied by increased superoxide dismutase, glutathione peroxidase and catalase and decreased nitric oxide synthase in the liver of resveratrol group significantly (<it>P </it>< 0.05 vs steatosis group). Bacterial translocation was not found in any of the groups. Glucose levels were decreased in the group of rats given resveratrol (<it>P </it>< 0.05).</p> <p>Conclusion</p> <p>Resveratrol decreased NAFLD severity in rats. This effect was mediated, at least in part, by TNF-α inhibition and antioxidant activities.</p

    A Useful Form of the Abel Bound and Its Application to Estimator Threshold Prediction

    No full text
    International audienceThis correspondence investigates the Abel bound in order to predict the estimators mean square error (mse) threshold effect. A tractable and computationally efficient form of this bound is derived. This form combines the Chapman–Robbins and the Cramér–Rao bounds. This bound is applied to a data-aided carrier frequency estimation problem for which a closed-form expression is provided. An indicator of the signal-to-noise ratio threshold is proposed. A comparison with recent results on the Barankin bound (Chapman–Robbins version) shows the superiority of the Abel-bound version to predict the mse threshold without increasing the computational complexity

    TMPRSS4 regulates levels of integrin α5 in NSCLC through miR-205 activity to promote metastasis

    No full text
    TMPRSS4 is a membrane-anchored protease involved in cell migration and invasion in different cancer types including lung cancer. TMPRSS4 expression is increased in NSCLC and its inhibition through shRNA reduces lung metastasis. However, molecular mechanisms leading to the protumorigenic regulation of TMPRSS4 in lung cancer are unknown. METHODS: miR-205 was identified as an overexpressed gene upon TMPRSS4 downregulation through microarray analysis. Cell migration and invasion assays and in vivo lung primary tumour and metastasis models were used for functional analysis of miR-205 overexpression in H2170 and H441 cell lines. Luciferase assays were used to identify a new miR-205 direct target in NSCLC. RESULTS: miR-205 overexpression promoted an epithelial phenotype with increased E-cadherin and reduced fibronectin. Furthermore, miR-205 expression caused a G0/G1 cell cycle arrest and inhibition of cell growth, migration, attachment to fibronectin, primary tumour growth and metastasis formation in vivo. Integrin α5 (a proinvasive protein) was identified as a new miR-205 direct target in NSCLC. Integrin α5 downregulation in lung cancer cells resulted in complete abrogation of cell migration, a decreased capacity to adhere to fibronectin and reduced in vivo tumour growth, compared with control cells. TMPRSS4 silencing resulted in a concomitant reduction of integrin α5 levels. CONCLUSION: We have demonstrated for the first time a new molecular pathway that connects TMPRSS4 and integrin α5 through miR-205 to regulate cancer cell invasion and metastasis. Our results will help designing new therapeutic strategies to inhibit this novel pathway in NSCLC
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