263 research outputs found

    Probabilistic Black-Box Checking via Active MDP Learning

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    We introduce a novel methodology for testing stochastic black-box systems, frequently encountered in embedded systems. Our approach enhances the established black-box checking (BBC) technique to address stochastic behavior. Traditional BBC primarily involves iteratively identifying an input that breaches the system's specifications by executing the following three phases: the learning phase to construct an automaton approximating the black box's behavior, the synthesis phase to identify a candidate counterexample from the learned automaton, and the validation phase to validate the obtained candidate counterexample and the learned automaton against the original black-box system. Our method, ProbBBC, refines the conventional BBC approach by (1) employing an active Markov Decision Process (MDP) learning method during the learning phase, (2) incorporating probabilistic model checking in the synthesis phase, and (3) applying statistical hypothesis testing in the validation phase. ProbBBC uniquely integrates these techniques rather than merely substituting each method in the traditional BBC; for instance, the statistical hypothesis testing and the MDP learning procedure exchange information regarding the black-box system's observation with one another. The experiment results suggest that ProbBBC outperforms an existing method, especially for systems with limited observation.Comment: Accepted to EMSOFT 202

    Prognostic significance of osteopontin expression in early-stage non-small-cell lung cancer

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    Osteopontin (OPN) is a multifunctional protein, which has recently been shown to be linked to tumorigenesis, progression and metastasis in different malignancies. Since non-small-cell lung cancer (NSCLC)'s prognosis remains bad, with few predictors of outcome, the purpose of this study was to evaluate if OPN might be involved in NSCLC's biology and therefore represent a prognostic marker and a target for new therapeutic trials. Immunohistochemistry was used to detect OPN expression, evaluated as percentage of neoplastic cells with cytoplasmic immunoreactivity, in a wide cohort of patients with stage I NSCLC (136 cases). The median value of this series (20% of positive cells) was used as the cutoff value to distinguish tumours with low (<20%) from tumours with high (⩾20%) OPN expression. A statistically significant correlation between high levels of OPN and shorter overall (P=0.034) and disease-free (P=0.011) survival in our patients was shown. Our results support the hypothesis that high OPN expression is a significantly unfavourable prognostic factor for the survival of patients with stage I NSCLC. This conclusion has notable importance in terms of the biological characterization of early-stage tumours and therapeutic opportunities

    Expression of Pulmonary Surfactant Protein A (SP-A) in Lung Cancer Lines

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    Pulmonary surfactant protein A (SP-A) is known to be a major phospholipid- associated 28-35 kDa glycoprotein in pulmonary surfactant, which is specific to the lung. Immunohistochemically, SP-A expression in the tumor tissues is demonstrated in approximately half of the cases of primary lung adenocarcinoma, but not in other histologic types of lung cancer nor in metas-tatic lung tumors. In the present study, to evaluate SP-A synthesis and secre-tion from lung cancer lines, SP-A content in culture supernatants was measured with SP-A enzyme linked immunosorbent assay and SP-A expression in tumor cells was analyzed immunohistochemically employing 10 lung adenocarcinoma lines, 3 lung epidermoid carcinoma lines and 5 lung small cell carcinoma lines. In only one line, LC117 out of 10 lung adenocarcinoma lines, SP-A content was high in the culture supernatant and SP-A was expressed in tumor cells, while other 9 lung adenocarcinoma lines, all lung epidermoid carcinoma lines and all lung small cell lines each exhibited a trace SP-A level in the culture supernatant and tumor cells alone failed to express SP-A. The present result indicated that in almost all lung adenocarcinoma lines function of SP-A synthesis may be lost during establishment of cancer lines

    Sputum and nasal lavage lung-specific biomarkers before and after smoking cessation

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    <p>Abstract</p> <p>Background</p> <p>Little is known about the effect of smoking cessation on airway inflammation. Secretory Leukocyte Protease Inhibitor (SLPI), Clara Cell protein 16 (CC16), elafin and human defensin beta-2 (HBD-2) protect human airways against inflammation and oxidative stress. In this longitudinal study we aimed to investigate changes in sputum and nasal lavage SLPI, CC16, elafin and HBD-2 levels in healthy smokers after 6 and 12 months of smoking cessation.</p> <p>Methods</p> <p>Induced sputum and nasal lavage was obtained from healthy current smokers (n = 76) before smoking cessation, after 6 months of smoking cessation (n = 29), after 1 year of smoking cessation (n = 22) and from 10 healthy never smokers. SLPI, CC16, elafin and HBD-2 levels were measured in sputum and nasal lavage supernatants by commercially available ELISA kits.</p> <p>Results</p> <p>Sputum SLPI and CC-16 levels were increased in healthy smokers before smoking cessation versus never-smokers (p = 0.005 and p = 0.08 respectively). SLPI and CC16 levels did not differ before and 6 months after smoking cessation (p = 0.118 and p = 0.543 respectively), neither before and 1 year after smoking cessation (p = 0.363 and p = 0.470 respectively). Nasal lavage SLPI was decreased 12 months after smoking cessation (p = 0.033). Nasal lavage elafin levels were increased in healthy smokers before smoking cessation versus never-smokers (p = 0.007), but there were no changes 6 months and 1 year after smoking cessation.</p> <p>Conclusions</p> <p>Only nasal lavage SLPI decrease after 1 year after smoking cessation. We may speculate that there is an ongoing inflammatory process stimulating the production of counter-regulating proteins in the airways of healthy ex-smokers.</p

    The cytokine-driven regulation of secretoglobins in normal human upper airway and their expression, particularly that of uteroglobin-related protein 1, in chronic rhinosinusitis

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    <p>Abstract</p> <p>Background</p> <p>The involvement of secretoglobins (SCGBs) other than SCGB1A1 (Clara cell 10-kDa protein, CC10) in human airway diseases remains unexplored. Among those SCGBs, SCGB3A2 (uteroglobin-related protein 1, UGRP1) is particularly interesting, given its structure and function similarities with SCGB1A1 (CC10). The aim of this study was to investigate the expression regulation of SCGBs other than SCGB1A1 (CC10) in human upper airway, and their potential involvement, particularly that of SCGB3A2 (UGRP1), in chronic rhinosinusitis (CRS) with nasal polyps (CRSwNP) and without nasal polyps (CRSsNP).</p> <p>Methods</p> <p>Eight SCGB family members including SCGB3A2 (UGRP1), SCGB1C1 (ligand binding protein RYD5), SCGB1D1 (lipophilin A), SCGB1D2 (lipophilin B), SCGB1D4 (interferon-γ inducible SCGB), SCGB2A1 (mammaglobin 2), SCGB2A2 (mammaglobin 1), and SCGB3A1 (uteroglobin-related protein 2) were studied. The regulation of SCGBs mRNA expression in normal nasal mucosa by proinflammatory, Th1, and Th2 cytokines was studied through nasal explant culture. SCGBs mRNA expression levels in CRSsNP and CRSwNP patients and controls were compared. The mRNA levels were detected by means of quantitative reverse transcriptase-polymerase chain reaction. The protein expression of SCGB3A2 (UGRP1) was analyzed using immunohistochemistry.</p> <p>Results</p> <p>The expression of SCGBs except SCGB1D2 (lipophilin B) could be found in upper airway and be differentially regulated by different cytokines. SCGB3A2 (UGRP1) mRNA expression was induced by Th1 cytokine, but suppressed by proinflammatory and Th2 cytokines. SCGBs mRNA expression was altered in CRS; particularly, SCGB3A2 (UGRP1) protein and mRNA expression was markedly decreased in both CRSsNP and CRSwNP and its protein levels inversely correlated with the number of total infiltrating cells, preoperative sinonasal CT scores, and postoperative endoscopy and symptom scores.</p> <p>Conclusion</p> <p>SCGBs except SCGB1D2 (lipophilin B) are expressed in human upper airway and their expression can be differentially regulated by inflammatory cytokines. SCGBs mRNA expression is altered in CRS. Reduced production of UGRP1, which is likely due, at least in part, to a local cytokine environment, may contribute to the hyper-inflammation in CRS and correlates with response to surgery.</p

    Susceptibility to COPD:Differential Proteomic Profiling after Acute Smoking

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    Cigarette smoking is the main risk factor for COPD (Chronic Obstructive Pulmonary Disease), yet only a subset of smokers develops COPD. Family members of patients with severe early-onset COPD have an increased risk to develop COPD and are therefore defined as "susceptible individuals". Here we perform unbiased analyses of proteomic profiles to assess how "susceptible individuals" differ from age-matched "non-susceptible individuals" in response to cigarette smoking. Epithelial lining fluid (ELF) was collected at baseline and 24 hours after smoking 3 cigarettes in young individuals susceptible or non-susceptible to develop COPD and older subjects with established COPD. Controls at baseline were older healthy smoking and non-smoking individuals. Five samples per group were pooled and analysed by stable isotope labelling (iTRAQ) in duplicate. Six proteins were selected and validated by ELISA or immunohistochemistry. After smoking, 23 proteins increased or decreased in young susceptible individuals, 7 in young non-susceptible individuals, and 13 in COPD in the first experiment; 23 proteins increased or decreased in young susceptible individuals, 32 in young non-susceptible individuals, and 11 in COPD in the second experiment. SerpinB3 and Uteroglobin decreased after acute smoke exposure in young non-susceptible individuals exclusively, whereas Peroxiredoxin I, S100A9, S100A8, ALDH3A1 (Aldehyde dehydrogenase 3A1) decreased both in young susceptible and non-susceptible individuals, changes being significantly different between groups for Uteroglobin with iTRAQ and for Serpin B3 with iTRAQ and ELISA measures. Peroxiredoxin I, SerpinB3 and ALDH3A1 increased in COPD patients after smoking. We conclude that smoking induces a differential protein response in ELF of susceptible and non-susceptible young individuals, which differs from patients with established COPD. This is the first study applying unbiased proteomic profiling to unravel the underlying mechanisms that induce COPD. Our data suggest that SerpinB3 and Uteroglobin could be interesting proteins in understanding the processes leading to COPD

    Plasma CC16 levels are associated with development of ALI/ARDS in patients with ventilator-associated pneumonia: a retrospective observational study

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    <p>Abstract</p> <p>Background</p> <p>Despite consensus criteria, diagnosing acute lung injury, or its more severe form acute respiratory distress syndrome (ALI/ARDS) remains challenging. Adding objective measures, such as plasma levels of biological markers could facilitate recognition of ALI/ARDS. This study was designed to assess and compare the diagnostic accuracy of biological markers for ALI/ARDS with ventilator-associated pneumonia (VAP).</p> <p>Methods</p> <p>We performed serial measurements of Clara cell protein (CC16), soluble receptor for advanced glycation end products (sRAGE), surfactant protein D (SP-D) and Krebs von den Lungen (KL-6) in plasma of patients with VAP and mechanically ventilated control patients without VAP. ALI/ARDS was diagnosed using the criteria of the North-American European consensus conference.</p> <p>Results</p> <p>Thirty-seven patients were enrolled - 22 patients with VAP and 15 control patients. Ten patients with pneumonia met the ALI/ARDS consensus criteria. Control patients never met these criteria. Plasma CC16 had a good diagnostic capacity for ALI/ARDS as shown by the receiver operating characteristic curve with an area under the curve of 0.91 (95% confidence interval (CI) 0.79 - 1.00; <it>p </it>< 0.001). Identification of ALI/ARDS patients by sudden increases in plasma CC16 of 30% or more yielded a sensitivity of 90% and a specificity of 92%. Of note, levels of CC16 increased 2 days before ALI/ARDS diagnosis. A cut-off level of 50 ng/ml SP-D yielded a specificity of 100% while the sensitivity was 70%. The area under the curve for SP-D was 0.80 (95% CI 0.58 - 1.00; <it>p </it>= 0.02). The diagnostic accuracies of KL-6 and sRAGE were low.</p> <p>Conclusion</p> <p>Plasma CC16 seems a potential biological marker for ALI/ARDS in patients with VAP. Plasma levels of sRAGE, SP-D and KL-6 have limited discriminative power for diagnosing ALI/ARDS in VAP.</p

    Expression profiling of familial breast cancers demonstrates higher expression of FGFR2 in BRCA2-associated tumors

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    BackgroundBRCA1- and BRCA2-associated tumors appear to have distinct molecular signatures. BRCA1-associated tumors are predominantly basal-like cancers, whereas BRCA2-associated tumors have a predominant luminal-like phenotype. These two molecular signatures reflect in part the two cell types found in the terminal duct lobular unit of the breast. To elucidate novel genes involved in these two spectra of breast tumorigenesis we performed global gene expression analysis on breast tumors from germline BRCA1 and BRCA2 mutation carriers. Methodology Breast tumor RNAs from 7 BRCA1 and 6 BRCA2 mutation carriers were profiled using UHN human 19K cDNA microarrays. Supervised univariate analyses were conducted to identify genes differentially expressed between BRCA1 and BRCA2-associated tumors. Selected discriminatory genes were validated using real time reverse transcription polymerase chain reaction in the tumor RNAs, and/or by immunohistochemistry (IHC) or by in situ hybridization (ISH) on tissue microarrays (TMAs) containing an independent set of 58 BRCA1 and 64 BRCA2-associated tumors. Results Genes more highly expressed in BRCA1-associated tumors included stathmin, osteopontin, TGFβ2 and Jagged 1 in addition to genes previously identified as characteristic of basal-like breast cancers. BRCA2-associated cancers were characterized by the higher relative expression of FGF1 and FGFR2. FGFR2 protein was also more highly expressed in BRCA2-associated cancers (P = 0.004). SignificanceBRCA1-associated tumours demonstrated increased expression of component genes of the Notch and TGFβ pathways whereas the higher expression of FGFR2 and FGF1 in BRCA2-associated cancers suggests the existence of an autocrine stimulatory loop

    VEGFA Upregulates FLJ10540 and Modulates Migration and Invasion of Lung Cancer via PI3K/AKT Pathway

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    BACKGROUND: Lung adenocarcinoma is the leading cause of cancer-related deaths among both men and women in the world. Despite recent advances in diagnosis and treatment, the mortality rates with an overall 5-year survival of only 15%. This high mortality is probably attributable to early metastasis. Although several well-known markers correlated with poor/metastasis prognosis in lung adenocarcinoma patients by immunohistochemistry was reported, the molecular mechanisms of lung adenocarcinoma development are still not clear. To explore novel molecular markers and their signaling pathways will be crucial for aiding in treatment of lung adenocarcinoma patients. METHODOLOGY/PRINCIPAL FINDINGS: To identify novel lung adenocarcinoma-associated /metastasis genes and to clarify the underlying molecular mechanisms of these targets in lung cancer progression, we created a bioinformatics scheme consisting of integrating three gene expression profile datasets, including pairwise lung adenocarcinoma, secondary metastatic tumors vs. benign tumors, and a series of invasive cell lines. Among the novel targets identified, FLJ10540 was overexpressed in lung cancer tissues and is associated with cell migration and invasion. Furthermore, we employed two co-expression strategies to identify in which pathway FLJ10540 was involved. Lung adenocarcinoma array profiles and tissue microarray IHC staining data showed that FLJ10540 and VEGF-A, as well as FLJ10540 and phospho-AKT exhibit positive correlations, respectively. Stimulation of lung cancer cells with VEGF-A results in an increase in FLJ10540 protein expression and enhances complex formation with PI3K. Treatment with VEGFR2 and PI3K inhibitors affects cell migration and invasion by activating the PI3K/AKT pathway. Moreover, knockdown of FLJ10540 destabilizes formation of the P110-alpha/P85-alpha-(PI3K) complex, further supporting the participation of FLJ10540 in the VEGF-A/PI3K/AKT pathway. CONCLUSIONS/SIGNIFICANCE: This finding set the stage for further testing of FLJ10540 as a new therapeutic target for treating lung cancer and may contribute to the development of new therapeutic strategies that are able to block the PI3K/AKT pathway in lung cancer cells
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