3,518 research outputs found

    Genome-scale modeling of Chinese hamster ovary cells by hybrid semi-parametric flux balance analysis

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    Funding Information: This work was sponsored by GlaxoSmithKline Biologicals SA whereby the NOVA University Lisbon was engaged under an Agreement for R and D Services. All authors were involved in the conception and design of the study. PD’s lab performed the experiments/acquired the data. JR, GO, RO analyzed and interpreted the data. All authors were involved in drafting the manuscript or critically revising it for important intellectual content. All authors had full access to the data and approved the manuscript before it was submitted by the corresponding author. Publisher Copyright: © 2022, The Author(s).Flux balance analysis (FBA) is currently the standard method to compute metabolic fluxes in genome-scale networks. Several FBA extensions employing diverse objective functions and/or constraints have been published. Here we propose a hybrid semi-parametric FBA extension that combines mechanistic-level constraints (parametric) with empirical constraints (non-parametric) in the same linear program. A CHO dataset with 27 measured exchange fluxes obtained from 21 reactor experiments served to evaluate the method. The mechanistic constraints were deduced from a reduced CHO-K1 genome-scale network with 686 metabolites, 788 reactions and 210 degrees of freedom. The non-parametric constraints were obtained by principal component analysis of the flux dataset. The two types of constraints were integrated in the same linear program showing comparable computational cost to standard FBA. The hybrid FBA is shown to significantly improve the specific growth rate prediction under different constraints scenarios. A metabolically efficient cell growth feed targeting minimal byproducts accumulation was designed by hybrid FBA. It is concluded that integrating parametric and nonparametric constraints in the same linear program may be an efficient approach to reduce the solution space and to improve the predictive power of FBA methods when critical mechanistic information is missing.publishersversionpublishe

    Analytical method for the determination of strychnine in tissues by gas chromatography/mass spectrometry: two case reports

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    This paper describes an analytical method for strychnine determination in biological samples by gas chromatography/mass spectrometry and their application in the investigation of two cases involving strychnine ingestion: A fatal case and a clinical one. The strychnine is isolated from biological samples using a liquid-liquid extraction procedure. The clean-up procedure is performed using an acid solution. Papaverine is used as internal standard in the quantification of strychnine. In the analysed specimens, the limits of quantification were 0.1 [mu]g/ml or 0.1 [mu]g/g. The recovery rate ranged from 75.0% to 98.7% and the coefficients of variation ranged from 4.8% to 10.5%.http://www.sciencedirect.com/science/article/B6T6W-408KCFB-8/1/f8bbeefad9e20909aef50467f67a2e8

    Impact of the APE1 Redox Function Inhibitor E3330 in Non-Small Cell Lung Cancer Cells Exposed to Cisplatin : Increased Cytotoxicity and Impairment of Cell Migration and Invasion

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    Elevated expression levels of the apurinic/apyrimidinic endonuclease 1 (APE1) have been correlated with the more aggressive phenotypes and poor prognosis of non-small cell lung cancer (NSCLC). This study aimed to assess the impact of the inhibition of the redox function of APE1 with E3330 either alone or in combination with cisplatin in NSCLC cells. For this purpose, complementary endpoints focusing on cell viability, apoptosis, cell cycle distribution, and migration/invasion were studied. Cisplatin decreased the viability of H1975 cells in a time- and concentration-dependent manner, with IC values of 9.6 µM for crystal violet assay and 15.9 µM for 3-(4,5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. E3330 was clearly cytotoxic for concentrations above 30 µM. The co-incubation of E3330 and cisplatin significantly decreased cell viability compared to cisplatin alone. Regarding cell cycle distribution, cisplatin led to an increase in sub-G1, whereas the co-treatment with E3330 did not change this profile, which was then confirmed in terms of % apoptotic cells. In addition, the combination of E3330 and cisplatin at low concentrations decreased collective and chemotactic migration, and also chemoinvasion, by reducing these capabilities up to 20%. Overall, these results point to E3330 as a promising compound to boost cisplatin therapy that warrants further investigation in NSCLC

    Cytokeratin 7/19 expression inN-diethylnitrosamine-induced mouse hepatocellular lesions: implications for histogenesis International

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    Hepatocellular carcinoma (HCC) is a common malignancy with poor clinical outcome, whose histogenesis is the subject of intense debate. Specifically, expression ofcytokeratins (CKs) 7 and 19, associated with aggressive biological behaviour, is proposed to reflect a possible progenitor cell origin or tumour dedifferentiation towardsa primitive phenotype. This work addresses that problem by studying CKs 7 and 19expression in N-diethylnitrosamine (DEN)-induced mouse HCCs. ICR mice weredivided into six DEN-exposed and six matched control groups. Samples were takenfrom each group at consecutive time points. Hyperplastic foci (13 lesions) occurredat 29-40 weeks (groups 8, 10 and 12) with diffuse dysplastic areas (19 lesions) andwith one hepatocellular adenoma (HCA) (at 29 weeks). HCCs (4 lesions) wereobserved 40 weeks after the first DEN administration (group 12). CKs 7 and 19showed identical expression patterns and located to large, mature hepatocytes, isolated or in small clusters. Hyperplastic foci and the single HCA were consistentlynegative for both markers, while dysplastic areas and HCCs were positive. Theseresults support the hypothesis that CKs 7 and 19 expression in hepatocellular malignancies results from a dedifferentiation process rather than from a possible progenitor cell origin

    Producing magnetic nanocomposites from paper sludge for the adsorptive removal of pharmaceuticals from water: a fractional factorial design

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    In view of a simple after-use separation, the potentiality of producing magnetic activated carbon (MAC) by intercalation of ferromagnetic metal oxide nanoparticles in the framework of a powder activated carbon (PAC) produced from primary paper sludge was explored in this work. The synthesis conditions to produce cost effective and efficient MACs for the adsorptive removal of pharmaceuticals (amoxicillin, carbamazepine, and diclofenac) from aqueous media were evaluated. For this purpose, a fractional factorial design (FFD) was applied to assess the effect of the most significant variables (Fe3+ to Fe2+ salts ratio, PAC to iron salts ratio, temperature, and pH), on the following responses concerning the resulting MACs: Specific surface area (SBET), saturation magnetization (Ms), and adsorption percentage of amoxicillin, carbamazepine, and diclofenac. The statistical analysis revealed that the PAC to iron salts mass ratio was the main factor affecting the considered responses. A quadratic linear regression model A = f(SBET, Ms) was adjusted to the FFD data, allowing to differentiate four of the eighteen MACs produced. These MACs were distinguished by being easily recovered from aqueous phase using a permanent magnet (Ms of 22-27 emu g-1), and their high SBET (741-795 m2 g-1) were responsible for individual adsorption percentages ranging between 61% and 84% using small MAC doses (35 mg L-1).publishe

    MRI analysis of the relationship between bone changes in the temporomandibular joint and articular disc position in symptomatic patients

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    Objectives: The aim of this study was to investigate bone changes in the condyle, articular eminence and glenoid fossa in relation to the position of the articular disc. Methods: 148 temporomandibular joints (TMJs) of 74 symptomatic patients who underwent MRI were evaluated. The position of the disc was classified as either normal (N), disc displacement with reduction (DDwR), disc displacement without reduction (DDwoR) and posterior displacement (PD). Bone changes were investigated in the condyle and temporal components of the TMJ and classified as osteophytosis, sclerosis or erosion. Results: There were no bone changes in the glenoid fossa of the temporal bone. Of the total number of TMJs studied, 94 (63.5%) were N, 34 (23%) presented DDwoR, 19 (12.8%) presented DDwR and 1 (0.7%) presented PD. The bone changes in the condyle and posterior aspect of the articular eminence were associated with the position of the disc. The bone changes in the anterior aspect of the articular eminence were not associated with the position of the disc. Conclusion: In cases of DDwoR, bone changes in the condyles were more common. The combination of erosion and osteophytosis in the condyle and the bone changes of the posterior aspect of the articular eminence were associated with disc position. Dentomaxillofacial Radiology (2012) 41, 367-372. doi: 10.1259/dmfr/7931785

    The Usefulness of Inflammatory Biomarkers to Predict Anastomotic Leakage after Colorectal Surgery: Systematic Review and Meta-Analysis

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    Aim: Anastomotic leakage (AL) is a severe postoperative complication in colorectal surgery, but its preclinical diagnosis may improve outcomes and increase anastomotic salvage. This study aimed to assess the added value of serum biomarkers for early detection of colorectal AL. Method: We performed a comprehensive literature review, and a qualitative and quantitative analysis of papers retrieved from MEDLINE, Embase, PubMed, Web of Science, Scopus and the Cochrane Library. We included all studies published before September 2021 assessing the serum biomarkers white blood cells (WBC), C-reactive protein (CRP), procalcitonin (PCT) and calprotectin (CLP) for the early diagnosis of AL. Results: Fifteen studies that evaluated three different systemic biomarkers in the context of AL were identified, including 5150 patients. Diagnostic test accuracy was estimated for CRP and PCT. On postoperative day (POD) 5, the highest AUC (87.1%) and specificity (80.2%) values were estimated for CRP. Random-effects meta-analysis and total effect sizes estimation for the biomarkers CRP, PCT and WBC were performed according to POD. The concentration of serum biomarkers is significantly higher in patients presenting AL. Regarding the qualitative analysis, there was significant heterogeneity in the inclusion of different subcategories of the consensus definition of colorectal AL in each paper’s definition. Conclusion: The serum biomarkers CRP and PCT are moderate predictors for AL, showing a high heterogeneity among the studies. Combinations of these biomarkers might improve predictive accuracy, but more studies will be necessary to conduct a quality metaregression.info:eu-repo/semantics/publishedVersio

    Recommendations for Urine and Urinary Bladder Collection in Chemical Carcinogenesis Assays with Rodents

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    This review describes the technical procedures to collect and process urine and urinary bladder samples, during and at the end of urinary bladder carcinogenesis assays with small rodents. The applications, advantages and disadvantages of each method are also mentioned and discussed

    Can preferential credit programs speed up the adoption of low-carbon agricultural systems in Mato Grosso, Brazil? Results from bioeconomic microsimulation

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    The need to balance agricultural production and environmental protection shifted the focus of Brazilian land-use policy toward sustainable agriculture. In 2010, Brazil established preferential credit lines to finance investments into low-carbon integrated agricultural systems of crop, livestock and forestry. This article presents a simulation-based empirical assessment of integrated system adoption in the state of Mato Grosso, where highly mechanized soybean–cotton and soybean–maize doublecrop systems currently prevail. We employ bioeconomic modeling to explicitly capture the heterogeneity of farm level costs and benefits of adoption. By parameterizing and validating our simulations with both empirical and experimental data, we evaluate the effectiveness of the ABC Integration credit through indicators such as land-use change, adoption rates and budgetary costs of credit provision. Alternative scenarios reveal that specific credit conditions might speed up the diffusion of low-carbon agricultural systems in Mato Grosso

    Standardization of Laboratory and Lipid Profile Evaluation: a Call for Action with a Special Focus in 2016 ESC/EAS Dyslipidaemia Guidelines - Full Report

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    Even with the improvement in lifestyle interventions, a better control of cardiovascular (CV) risk factors, and improvements in CV outcomes, cardiovascular disease (CVD) still persists as the leading cause of morbidity and mortality in Portugal and Europe. Atherogenic dyslipidaemias, namely hypercholesterolaemia, have a crucial and causal role in the development of atherosclerotic CVD. The clinical approach of a patient with dyslipidaemia involves a watchful diagnosis, sustained in lipid and lipoprotein laboratory procedures, which must be harmonized and standardized. Standardization of lipid test results and reports, incorporating the total CV risk and the respective target and goals of treatment approach, guarantees that clinical guidelines and good clinical practices are followed and respected, increasing the reliability of lipid disorders screening, producing more accurate diagnoses and CV risk stratification, and improving the CV prevention and the achievement the desirable treatment goals.info:eu-repo/semantics/publishedVersio
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