245 research outputs found

    Application of a Multienzymatic System from Natural Latex in Key Reactions for oil-Based Biorefineries

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    Oil-based biorefineries play a crucial role in the production of key platform chemicals that can be generated via biotechnological processes instead of a petrochemical route. This work focuses on the latex of the fruit of Araujia sericifera, which can be considered a multienzymatic system with applications in key reactions in oil-based biorefineries. The latex of Araujia sericifera (ASL) was used as a novel biocatalyst in the esterification of oleic acid and in the hydrolysis of triglycerides and p-nitrophenyl carboxylates. When ASL was compared to a commercial biocatalyst, it showed an excellent activity in the hydrolysis of soybean oil and p-nitropheyl laurate, and a comparable activity in the esterification reaction.Centro de Investigación de Proteínas Vegetales (CIProVe)Facultad de Ciencias Exacta

    Efectos de la formación de directivos en las pymes españolas

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    A pesar de que la formación se considera imprescindible para que la empresa pueda desarrollar ventajas competitivas sostenibles y de que los directivos suelen ser el colectivo al que se dedica la mayor parte de las inversiones en esta área, poco se sabe sobre las repercusiones que esto tiene en los resultados globales de la empresa. Por ello, el presente trabajo, tras revisar la literatura teórica y empírica, estudia si la inversión en formación de directivos influye sobre los resultados organizativos, utilizando para ello una muestra de 214 pymes españolas. Los análisis efectuados identifican algunos efectos significativos

    Application of a Multienzymatic System from Natural Latex in Key Reactions for oil-Based Biorefineries

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    Oil-based biorefineries play a crucial role in the production of key platform chemicals that can be generated via biotechnological processes instead of a petrochemical route. This work focuses on the latex of the fruit of Araujia sericifera, which can be considered a multienzymatic system with applications in key reactions in oil-based biorefineries. The latex of Araujia sericifera (ASL) was used as a novel biocatalyst in the esterification of oleic acid and in the hydrolysis of triglycerides and p-nitrophenyl carboxylates. When ASL was compared to a commercial biocatalyst, it showed an excellent activity in the hydrolysis of soybean oil and p-nitropheyl laurate, and a comparable activity in the esterification reaction.Centro de Investigación de Proteínas Vegetales (CIProVe)Facultad de Ciencias Exacta

    Cerebrospinal fluid Presenilin-1 increases at asymptomatic stage in genetically determined Alzheimer’s disease

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    [Background] Presenilin-1 (PS1), the active component of the intramembrane γ-secretase complex, can be detected as soluble heteromeric aggregates in cerebrospinal fluid (CSF). The aim of this study was to examine the different soluble PS1 complexes in the lumbar CSF (CSF-PS1) of individuals with Alzheimer’s disease (AD), particularly in both symptomatic and asymptomatic genetically determined AD, in order to evaluate their potential as early biomarkers.[Methods] Western blotting, differential centrifugation and co-immunoprecipitation served to determine and characterize CSF-PS1 complexes. We also monitored the assembly of soluble PS1 into complexes in a cell model, and the participation of Aβ in the dynamics and robustness of the stable PS1 complexes.[Results] There was an age-dependent increase in CSF-PS1 levels in cognitively normal controls, the different complexes represented in similar proportions. The total levels of CSF-PS1, and in particular the proportion of the stable 100–150 kDa complexes, increased in subjects with autosomal dominant AD that carried PSEN1 mutations (eight symptomatic and six asymptomatic ADAD) and in Down syndrome individuals (ten demented and ten non-demented DS), compared with age-matched controls (n = 23), even prior to the appearance of symptoms of dementia. The proportion of stable CSF-PS1 complexes also increased in sporadic AD (n = 13) and mild-cognitive impaired subjects (n = 12), relative to age-matched controls (n = 17). Co-immunoprecipitation demonstrated the association of Aβ oligomers with soluble PS1 complexes, particularly the stable complexes.[Conclusions] Our data suggest that CSF-PS1 complexes may be useful as an early biomarker for AD, reflecting the pathology at asymptomatic state.This study was funded in part by the EU BIOMARKAPD-Joint Programming on Neurodegenerative Diseases (JPND) project, by the Instituto de Salud Carlos III (ISCIII grants PI11/03026 to JSV, PI11/02425 and PI14/01126 to JF, PI11/03035 and PI14/1561 to AL, PI08/0036 and PI12/00013 to RSV, and PI11/03023 to JLM), co-financed by the Fondo Europeo de Desarrollo Regional, under the aegis of JPND, and through CIBERNED, ISCIII. This work was also supported by the Fundació Catalana de Síndrome de Down and by a “Marató TV3” grant (20141210 to JF) and a grant from the Griffols Foundation. The funding bodies played no role in the study design, data collection and analysis, the decision to publish, or the preparation of the manuscript. We also acknowledge the support for the publication fee to the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).Peer reviewe

    Evaluating the performance of Bayesian and frequentist approaches for longitudinal modeling: application to Alzheimers disease

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    Linear mixed effects (LME) modelling under both frequentist and Bayesian frameworks can be used to study longitudinal trajectories. We studied the performance of both frameworks on different dataset configurations using hippocampal volumes from longitudinal MRI data across groups-healthy controls (HC), mild cognitive impairment (MCI) and Alzheimer's disease (AD) patients, including subjects that converted from MCI to AD. We started from a big database of 1250 subjects from the Alzheimer's disease neuroimaging initiative (ADNI), and we created different reduced datasets simulating real-life situations using a random-removal permutation-based approach. The number of subjects needed to differentiate groups and to detect conversion to AD was 147 and 115 respectively. The Bayesian approach allowed estimating the LME model even with very sparse databases, with high number of missing points, which was not possible with the frequentist approach. Our results indicate that the frequentist approach is computationally simpler, but it fails in modelling data with high number of missing values

    Increased Cortical Thickness and Caudate Volume Precede Atrophy in PSEN1 Mutation Carriers

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    Neuroimaging studies of familial Alzheimer's disease allow investigation of the disease process before clinical onset. We performed semi-automated MRI analysis to evaluate cortical thickness (CTh), grey matter (GM) volumes, and GM diffusivity indexes in PSEN1 mutation carriers (MC). We recruited 11 MC from 4 families with PSEN1 mutations (L286P, M139T, K239N) and 6 familial and 12 non-familial healthy controls. MC were classified as either asymptomatic (n=6) or symptomatic (n=5). Subjects underwent structural and diffusion-weighted 3-Tesla MRI scanning. CTh and GM volumes of subcortical structures and diffusivity indexes were calculated and group comparisons were performed. Structural images were reanalyzed with voxel-based morphometry methodology. Cerebrospinal fluid amyloid-β1-42 levels (Aβ) were measured. We found that symptomatic MC presented widespread cortical thinning, especially in precuneus and parietotemporal areas (p<0.01) and increased mean diffusivity (MD) in these areas compared to controls. Unexpectedly, asymptomatic MC, 9.9 years prior to the predicted age of disease onset, presented increased CTh in the precuneus and parietotemporal areas (p<0.01), increased caudate volumes (p<0.01), and decreased MD (p<0.05) in these areas compared to HC. In MC, CTh correlated with adjusted age. Aβ values were within normal limits in AMC. In conclusion, at early preclinical stages, CTh in the precuneus and parietotemporal regions and caudate volume increase in PSEN1 MC and decrease thereafter with disease progression. The different trends in MD in asymptomatic and symptomatic MC suggest that different microstructural changes underlie the contrasting morphometric findings. Reactive neuronal hypertrophy or/and inflammation may account for increased CTh and decreased MD in asymptomatic MC

    14-3-3 protein in the CSF as prognostic marker in early multiple sclerosis

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    Axonal damage probably occurs early in the evolution of MS. Five of 38 (13%) patients had a positive assay for the neuronal 14-3-3 protein in the CSF obtained at the first clinically isolated syndrome suggestive of MS. A positive 14-3-3 assay was the only independent predictor for a shorter time to conversion to clinical definite MS (risk ratio 4.1; 95% CI 1.1 to 15) and to reach an Expanded Disability Status Scale (EDSS) > or =2 at the end of follow-up (odds ratio 14.8; 95% CI 2.86 to 76.8). The detection of the 14-3-3 protein in the CSF at the first neurologic event suggestive of MS may be a useful predictor of short-term evolution

    Prognostic Role of the Expression of Latent-Membrane Protein 1 of Epstein-Barr Virus in Classical Hodgkin Lymphoma

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    The prognostic impact of the presence of Epstein-Barr virus (EBV) in classical Hodgkin lymphoma (cHL) is controversial. Previous studies reported heterogeneous results, rendering difficult the clinical validation of EBV as a prognostic biomarker in this lymphoma. The objective of this study was to evaluate the survival impact of the expression of EBV Latent-Membrane Protein 1 (EBV-LMP1) in tumoral Hodgkin-Reed-Sternberg (HRS) cells of primary diagnostic samples of cHL. Formalin-Fixed Paraffin-Embedded (FFPE) lymph node samples from 88 patients with cHL were analyzed. Patients were treated with the standard first-line chemotherapy (CT) with Adriamycin, Bleomycin, Vinblastine and Dacarbazine (ABVD) followed by radiotherapy. The Kaplan-Meier method and the Cox proportional hazards model were used for carrying out the survival analysis. In order to investigate whether the influence of EBV was age-dependent, analyses were performed both for patients of all ages and for age-stratified subgroups. In bivariate analysis, the expression of EBV was associated with older age (p = 0.011), mixed cellularity subtype cHL (p < 0.001) and high risk International Prognostic Score (IPS) (p = 0.023). Overall survival (OS) and progression-free survival (PFS) were associated with the presence of bulky disease (p = 0.009) and advanced disease at diagnosis (p = 0.016). EBV-positive cases did not present a significantly lower OS and PFS in comparison with EBV-negative cases, for all ages and when stratifying for age. When adjusted for covariates, absence of bulky disease at diagnosis (HR: 0.102, 95% CI: 0.02-0.48, p = 0.004) and limited disease stages (I-II) (HR: 0.074, 95% CI: 0.01-0.47, p = 0.006) were associated with a significant better OS. For PFS, limited-disease stages also retained prognostic impact in the multivariate Cox regression (HR: 0.145, 95% CI: 0.04-0.57, p = 0.006). These results are of importance as the early identification of prognostic biomarkers in cHL is critical for guiding and personalizing therapeutic decisions. The prognostic role of EBV in cHL could be modulated by the type of CT protocol employed and interact with the rest of presenting features

    Application of a Multienzymatic System from Natural Latex in Key Reactions for oil-Based Biorefineries

    Get PDF
    Oil-based biorefineries play a crucial role in the production of key platform chemicals that can be generated via biotechnological processes instead of a petrochemical route. This work focuses on the latex of the fruit of Araujia sericifera, which can be considered a multienzymatic system with applications in key reactions in oil-based biorefineries. The latex of Araujia sericifera (ASL) was used as a novel biocatalyst in the esterification of oleic acid and in the hydrolysis of triglycerides and p-nitrophenyl carboxylates. When ASL was compared to a commercial biocatalyst, it showed an excellent activity in the hydrolysis of soybean oil and p-nitropheyl laurate, and a comparable activity in the esterification reaction.Centro de Investigación de Proteínas Vegetales (CIProVe)Facultad de Ciencias Exacta

    White Matter Abnormalities Track Disease Progression in PSEN1 Autosomal Dominant Alzheimer's Disease

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    PSEN1 mutations are the most frequent cause of autosomal dominant Alzheimer's disease (ADAD), and show nearly full penetrance. There is presently increasing interest in the study of biomarkers that track disease progression in order to test therapeutic interventions in ADAD. We used white mater (WM) volumetric characteristics and diffusion tensor imaging (DTI) metrics to investigate correlations with the normalized time to expected symptoms onset (relative age ratio) and group differences in a cohort of 36 subjects from PSEN1 ADAD families: 22 mutation carriers, 10 symptomatic (SMC) and 12 asymptomatic (AMC), and 14 non-carriers (NC). Subjects underwent a 3T MRI. WM morphometric data and DTI metrics were analyzed. We found that PSEN1 MC showed significant negative correlation between fractional anisotropy (FA) and the relative age ratio in the genus and body of corpus callosum and corona radiate (p <  0.05 Family-wise error correction (FWE) at cluster level) and positive correlation with mean diffusivity (MD), axial diffusivity (AxD), and radial diffusivity (RD) in the splenium of corpus callosum. SMC presented WM volume loss, reduced FA and increased MD, AxD, and RD in the anterior and posterior corona radiate, corpus callosum (p <  0.05 FWE) compared with NC. No significant differences were observed between AMC and NC in WM volume or DTI measures. These findings suggest that the integrity of the WM deteriorates linearly in PSEN1 ADAD from the early phases of the disease; thus DTI metrics might be useful to monitor the disease progression. However, the lack of significant alterations at the preclinical stages suggests that these indexes might not be good candidates for early markers of the disease
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