250 research outputs found

    full-FORCE: A Target-Based Method for Training Recurrent Networks

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    Trained recurrent networks are powerful tools for modeling dynamic neural computations. We present a target-based method for modifying the full connectivity matrix of a recurrent network to train it to perform tasks involving temporally complex input/output transformations. The method introduces a second network during training to provide suitable "target" dynamics useful for performing the task. Because it exploits the full recurrent connectivity, the method produces networks that perform tasks with fewer neurons and greater noise robustness than traditional least-squares (FORCE) approaches. In addition, we show how introducing additional input signals into the target-generating network, which act as task hints, greatly extends the range of tasks that can be learned and provides control over the complexity and nature of the dynamics of the trained, task-performing network.Comment: 20 pages, 8 figure

    Reconstruction of metabolic networks from high-throughput metabolite profiling data: in silico analysis of red blood cell metabolism

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    We investigate the ability of algorithms developed for reverse engineering of transcriptional regulatory networks to reconstruct metabolic networks from high-throughput metabolite profiling data. For this, we generate synthetic metabolic profiles for benchmarking purposes based on a well-established model for red blood cell metabolism. A variety of data sets is generated, accounting for different properties of real metabolic networks, such as experimental noise, metabolite correlations, and temporal dynamics. These data sets are made available online. We apply ARACNE, a mainstream transcriptional networks reverse engineering algorithm, to these data sets and observe performance comparable to that obtained in the transcriptional domain, for which the algorithm was originally designed.Comment: 14 pages, 3 figures. Presented at the DIMACS Workshop on Dialogue on Reverse Engineering Assessment and Methods (DREAM), Sep 200

    Distinct RNA profiles in subpopulations of extracellular vesicles: apoptotic bodies, microvesicles and exosomes

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    Introduction: In recent years, there has been an exponential increase in the number of studies aiming to understand the biology of exosomes, as well as other extracellular vesicles. However, classification of membrane vesicles and the appropriate protocols for their isolation are still under intense discussion and investigation. When isolating vesicles, it is crucial to use systems that are able to separate them, to avoid cross-contamination. Method: EVs released from three different kinds of cell lines: HMC-1, TF-1 and BV-2 were isolated using two centrifugation-based protocols. In protocol 1, apoptotic bodies were collected at 2,000×g, followed by filtering the supernatant through 0.8 µm pores and pelleting of microvesicles at 12,200×g. In protocol 2, apoptotic bodies and microvesicles were collected together at 16,500×g, followed by filtering of the supernatant through 0.2 µm pores and pelleting of exosomes at 120,000×g. Extracellular vesicles were analyzed by transmission electron microscopy, flow cytometry and the RNA profiles were investigated using a Bioanalyzer®. Results: RNA profiles showed that ribosomal RNA was primary detectable in apoptotic bodies and smaller RNAs without prominent ribosomal RNA peaks in exosomes. In contrast, microvesicles contained little or no RNA except for microvesicles collected from TF-1 cell cultures. The different vesicle pellets showed highly different distribution of size, shape and electron density with typical apoptotic body, microvesicle and exosome characteristics when analyzed by transmission electron microscopy. Flow cytometry revealed the presence of CD63 and CD81 in all vesicles investigated, as well as CD9 except in the TF-1-derived vesicles, as these cells do not express CD9. Conclusions: Our results demonstrate that centrifugation-based protocols are simple and fast systems to distinguish subpopulations of extracellular vesicles. Different vesicles show different RNA profiles and morphological characteristics, but they are indistinguishable using CD63-coated beads for flow cytometry analysis

    Identification and validation of common molecular targets of hydroxytyrosol

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    Hydroxytyrosol (HT) is involved in healthful activities and is beneficial to lipid metabolism. Many investigations focused on finding tissue-specific targets of HT through the use of different omics approaches such as transcriptomics and proteomics. However, it is not clear which (if any) of the potential molecular targets of HT reported in different studies are concurrently affected in various tissues. Following the bioinformatic analyses of publicly available data from a selection of in vivo studies involving HT-supplementation, we selected differentially expressed lipid metabolism-related genes and proteins common to more than one study, for validation in rodent liver samples from the entire selection. Four miRNAs (miR-802-5p, miR-423-3p, miR-30a-5p, and miR-146b-5p) responded to HT supplementation. Of note, miR-802-5p was commonly regulated in the liver and intestine. Our premise was that, in an organ crucial for lipid metabolism such as the liver, consistent modulation should be found for a specific target of HT even if different doses and duration of HT supplementation were used in vivo. Even though our results show inconsistency regarding differentially expressed lipid metabolism-related genes and proteins across studies, we found Fgf21 and Rora as potential novel targets of HT. Omics approaches should be fine-tuned to better exploit the available databases

    Análisis de paleodietas humanas en zonas áridas a través de isótopos estables: el caso de Antofagasta de la Sierra (noroeste argentino)

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    This article presents preliminary advances in the human paleodietary characterization of individuals from the Antofagasta de la Sierra, puna de Catamarca (Northwestern Argentina) micro-region. Samples belong to individuals from different agro-pastoral periods from the Late Holocene. A methodology based on stable isotope analysis (δ13C collagen y δ15N; δ13C apatite) was applied to a total of 14 individuals, taking into consideration local and neighboring resources. Results indicate that in most cases consumption of C4 vegetable species like maize (Zea mays) and amaranth (Amaranthus caudatus) was less relevant vis-à-vis other resources, while meat resources from lower elevations of the Puna eco-region were of higher importance https://doi.org/10.22380/2539472X44Este artículo presenta los primeros avances en la caracterización paleodietaria humana de individuos pertenecientes a la microrregión de Antofagasta de la Sierra, puna de Catamarca (noroeste argentino), correspondientes a diferentes periodos agropastoriles del Holoceno Tardío. Sobre un total de 14 individuos se aplicó una metodología basada en el análisis de isótopos estables (δ13 Ccolágeno y δ15N; δ13C apatita), considerando recursos locales y de áreas aledañas. Los resultados indican que el consumo de especies vegetales C4 , como el maíz (Zea mays) y el amaranto (Amaranthus caudatus), es menos importante respecto a otros recursos en la mayoría de los casos analizados, y son más relevantes los recursos cárnicos provenientes de las cotas más bajas de la ecorregión puna.      https://doi.org/10.22380/2539472X4

    An adaptive phase II/III safety and efficacy randomized controlled trial of single day or three-day fixed-dose albendazole-ivermectin co-formulation versus albendazole for the treatment of Trichuris trichiura and other STH infections. ALIVE trial protocol

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    18 páginas, 2 tablas, 1 figura.Background: Soil-transmitted helminths (STH) are targeted for control through mass drug-administration campaigns to prevent morbidity affecting at-risk groups in endemic regions. Although broadly successful, the use of albendazole and mebendazole achieved variable progress, with deficiencies against Trichuris trichiura and a predictable low efficacy against Strongyloides stercoralis. Novel drug combinations offer a potential solution, providing they can be delivered safely and maintain efficacy against all STH species. Here we present the protocol of a clinical trial to evaluate a fixed-dose combination (FDC) tablet containing albendazole and ivermectin that will be compared against albendazole against STH. Methods: An adaptive phase II/III randomized controlled trial will be undertaken in STH endemic sites in Ethiopia, Kenya and Mozambique to evaluate an oral FDC of 400 mg albendazole and either 9- or 18 mg ivermectin. FDC will be administered as a single dose or single doses over three-consecutive days and assessed against a single dose of 400 mg albendazole. In the phase II trial, 126 T. trichiura-infected children weighting 15 to 45 kg will be treated in a dose-escalation manner to determine safety objectives. In the phase III trial, 1097 participants aged 5 to 18 years old infected with T. trichiura, hookworm and S. stercoralis will be recruited to determine safety and efficacy. The trial will be open-label with blinded outcome assessors. Cure rate measured 21-days after-treatment in duplicate Kato-Katz is the primary efficacy outcome. Secondary objectives include efficacy evaluation by quantitative polymerase chain reaction (PCR) as an outcome measurement, description of pharmacokinetic parameters, palatability and acceptability evaluations, and monitoring of anthelmintic resistance. Conclusions: This trial with registrational goals seeks to evaluate an innovative fixed-dose combination of albendazole and ivermectin co-formulated tablets, with the goal of providing an anthelmintic regimen with improved efficacy and spectrum of coverage against STH. ClinicalTrials.gov registration: NCT05124691 (18/11/2021)

    Galectin-1 prevents pathological vascular remodeling in atherosclerosis and abdominal aortic aneurysm

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    Pathological vascular remodeling is the underlying cause of atherosclerosis and abdominal aortic aneurysm (AAA). Here, we analyzed the role of galectin-1 (Gal-1), a β-galactoside-binding protein, as a therapeutic target for atherosclerosis and AAA. Mice lacking Gal-1 (Lgals1 −/− ) developed severe atherosclerosis induced by pAAV/D377Y-mPCSK9 adenovirus and displayed higher lipid levels and lower expression of contractile markers of vascular smooth muscle cells (VSMCs) in plaques than wild-type mice. Proteomic analysis of Lgals1 −/− aortas showed changes in markers of VSMC phenotypic switch and altered composition of mitochondrial proteins. Mechanistically, Gal-1 silencing resulted in increased foam cell formation and mitochondrial dysfunction in VSMCs, while treatment with recombinant Gal-1 (rGal-1) prevented these effects. Furthermore, rGal-1 treatment attenuated atherosclerosis and elastase-induced AAA, leading to higher contractile VSMCs in aortic tissues. Gal-1 expression decreased in human atheroma and AAA compared to control tissue. Thus, Gal-1-driven circuits emerge as potential therapeutic strategies in atherosclerosis and AAA. Galectin-1 plays an essential role in prevention of atherosclerosis and abdominal aortic aneurysm

    Factors associated with the development of septic shock in patients with candidemia: A post hoc analysis from two prospective cohorts

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    Background: Almost one third of the patients with candidemia develop septic shock. The understanding why some patients do and others do not develop septic shock is very limited. The objective of this study was to identify variables associated with septic shock development in a large population of patients with candidemia. Methods: A post hoc analysis was performed on two prospective, multicenter cohort of patients with candidemia from 12 hospitals in Spain and Italy. All episodes occurring from September 2016 to February 2018 were analyzed to assess variables associated with septic shock development defined according to The Third International Consensus Definition for Sepsis and Septic Shock (Sepsis-3). Results: Of 317 candidemic patients, 99 (31.2%) presented septic shock attributable to candidemia. Multivariate logistic regression analysis identifies the following factors associated with septic shock development: age > 50 years (OR 2.57, 95% CI 1.03-6.41, p = 0.04), abdominal source of the infection (OR 2.18, 95% CI 1.04-4.55, p = 0.04), and admission to a general ward at the time of candidemia onset (OR 0.21, 95% CI, 0.12-0.44, p = 0.001). Septic shock development was independently associated with a greater risk of 30-day mortality (OR 2.14, 95% CI 1.08-4.24, p = 0.02). Conclusions: Age and abdominal source of the infection are the most important factors significantly associated with the development of septic shock in patients with candidemia. Our findings suggest that host factors and source of the infection may be more important for development of septic shock than intrinsic virulence factors of organisms
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