Search Results (50)

Early biomarkers are needed to predict the long-term persistence of rheumatical symptoms in patients infected with Chikungunya virus (CHIKV). This nested case-control study aimed to assess immunological factors during the early phases of CHIKV infection to predict the risk of post-CHIK chronic rheumatism (pCHIK-CR) in adult patients of two prospective cohorts. We evaluated 46 febrile patients (median age: 33.5 years; IQR: 19 years; women: 50.0%) with CHIKV infection confirmed during the 2014–2015 outbreak in Santander, Colombia. The participants were classified by a rheumatologist as either cases (pCHIK-CR) or controls (WoRM, without rheumatical manifestations). We quantified serum levels of IL-4, IL-6, IL-8/CXCL-8, IL-27, CCL-2, CXCL-9, CXCL-10, and IgG using Luminex and ELISA assays during the acute and subacute phases of infection. Then, we evaluated the association of these immune factors with the case-control status using piecewise logistic regression adjusted for age and sex. There were non-linear associations between IL-8/CXCL-8, CXCL-9, and CXCL-10 with pCHIK-CR. Increases in the levels of IL-8/CXCL-8 (<35.7 pg/mL), CXCL-9 (≥6000 pg/mL), and CXCL-10 (≥36,800 pg/mL) were significantly associated with a reduced risk of pCHIK-CR (adjusted ORs: 0.85, 0.96, and 0.94, respectively). These results suggest that increases in IL-8/CXCL-8, CXCL-9, and CXCL-10 levels, measured in the early stages of CHIKV infection, may predict a chronic disease risk. This suggests the possibility that an early and strong immune response could contribute to enhancing CHIKV control and potentially reduce the risk of persistent joint symptoms. Given their expression patterns and timing, these three immune factors may be considered promising biomarker candidates for assessing the risk of chronic rheumatologic disease. These findings should be considered as exploratory and validated in additional cohort studies. Full article

The fish pathogen Yersinia ruckeri forms biofilms on abiotic surfaces, contributing to recurrent infections in aquaculture. Increasing evidence suggests that the RNA chaperone Hfq and small non-coding RNAs (sRNAs) are key regulators of bacterial biofilm formation. However, the regulatory mechanisms mediated by these factors remain largely unexplored in Y. ruckeri. In this study, we investigated the roles of Hfq and the Hfq-dependent sRNAs RprA, ArcZ, and RybB in the biofilm formation of Y. ruckeri. We first characterized the sRNAome of biofilm-forming cells, identifying the conserved RprA, ArcZ, and RybB, among the upregulated sRNAs. We then evaluated motility, biofilm formation, and architecture in strains lacking either hfq (Δhfq) or these sRNAs (ΔsRNA). Our results reveal that both Δhfq and ΔsRNA strains exhibit significant alterations in biofilm and motility phenotypes, including changes in bacterial morphology and extracellular matrix. Furthermore, expression analyses indicate that these sRNAs modulate the transcription of key regulatory factors, flagellar and phosphodiesterase genes, ultimately influencing intracellular cyclic di-GMP levels, a key second messenger in biofilm formation. Together, our findings demonstrate that Hfq and its associated sRNAs play critical regulatory roles in Y. ruckeri biofilm formation by controlling the expression of genes involved in motility, bacterial envelope proteins, and c-di-GMP metabolism. Full article

Air pollution from particulate matter 2.5 (PM_2.5) may negatively impact students’ learning due to its neurotoxic effects. Therefore, we ask: What is the effect of PM_2.5 air pollution on the academic performance of Chilean eighth-grade students? Objective: To compare the academic performance of eighth-grade students living in the three most PM_2.5-polluted areas of Chile with those living in the three least polluted areas. Additionally, we compared the academic performance of schools in the most and least polluted areas according to their administrative dependency. Methodology: Academic performance was assessed using the results of the 2019 SIMCE test (mathematics, and language score). The most and least polluted areas were determined based on the three-year average PM_2.5 levels reported by the Chilean Ministry of the Environment. Results: The mathematics and language scores were lower in schools located in areas with higher pollution PM_2.5 with a small effect size. When analyzing the scores by administrative dependency, students from subsidized schools in highly polluted areas obtained lower scores in all tests compared to those in less polluted areas, a pattern not observed in private or municipal schools. Conclusion: These findings suggest that PM_2.5 pollution alone may not fully explain variations in academic performance, highlighting the need to explore additional contributing factors. Full article

Increased abundance of Segatella copri (S. copri) within the gut microbiota is associated with systemic inflammatory diseases, including rheumatoid arthritis. Although outer-membrane vesicles (OMVs) of Gram-negative bacteria are important players in microbiota–host communication, the effect of S. copri-derived OMVs on immune cells is unknown. Macrophages engulf and eliminate foreign material and are conditioned by environmental signals to promote either homeostasis or inflammation. Thus, we aimed to explore the impact of S. copri-OMVs on human macrophages in vitro, employing THP-1 and monocyte-derived macrophage models. The uptake of DiO-labeled S. copri-OMVs into macrophages was monitored by confocal microscopy and flow cytometry. Furthermore, the effect of S. copri and S. copri-OMVs on the phenotype and cytokine secretion of naïve (M0), pro-inflammatory (M1), and anti-inflammatory (M2) macrophages was analyzed by flow cytometry and ELISA, respectively. We show that S. copri-OMVs enter human macrophages through macropinocytosis and clathrin-dependent mechanisms. S. copri-OMVs, but not the parental bacterium, induced a dose-dependent increase in the expression of M1-related surface markers in M0 and M2 macrophages and activated the secretion of large amounts of pro-inflammatory cytokines in M1 macrophages. These results highlight an important role of S. copri-OMVs in promoting pro-inflammatory macrophage responses, which might contribute to systemic inflammatory diseases. Full article

The seismic performance assessment of timber structures and topology optimization have been widely researched in recent years. Furthermore, the use of wood as a construction material has increased due to new sustainability challenges. This research assesses the seismic performance of a topologically optimized timber building located in Concepcion, Chile. The structure is a five-story glulam braced frame, designed following current Chilean standards. The structural configuration was obtained through a topology optimization process using a variation of a soft-kill BESO algorithm implemented in MATLAB R2015a, obtaining topologies with low structural redundancy. For the analysis, a full 3D nonlinear model was prepared using OpenSees (Version 3.7.1), and the nonlinear behavior of the structure was only considered at joints using the backbone curves introduced in ASCE 41-13. Six different study cases were analyzed, varying joint strengths and ductility. The fragility curves were determined from a static pushover analysis (SPO) using SPO2FRAG (V1.1), considering the performance levels established in ASCE 41-13. The seismic hazard of the building’s site is estimated through a probabilistic seismic hazard analysis (PSHA), and the seismic performance of each case is determined by computing the probabilities of exceedance of the considered limit states. Analysis results show that wood braced-frame structures with low structural redundancy (and fewer main joints to dissipate energy), such as those obtained from topology optimization algorithms, exhibit a markedly brittle behavior with almost no displacement ductility. This undesirable behavior does not improve by providing more deformation capacity to this structure’s reduced number of main joints. Currently, the Chilean standard for seismic design requires a unique response modification factor R for wood structures. This research suggests that this requirement should be revisited, specifying different R values depending on the wood structure’s redundancy, considering that its displacement ductility comes almost exclusively from the nonlinear deformation capacity of joints. Full article

This article presents a systematic review of sustainable watershed management at the international level. Based on the risk regulation approach, this review approaches the specific gaps in the literature related to relevant issues outlining the international freshwater resources socio-environmental regulation issue, especially in regards to its sociological dimensions: the organizational capabilities of agents involved in regulatory efforts, issue-implicit challenges, and regulatory effort-generated socio-environmental risks. The study identifies the reflexive components of the involved institutions, outlines the deployment of organizational processes in normative regulatory components, and explores the modalities for addressing change and complexity in the regulatory field. A corpus of 64 articles published in the Web of Science (WoS) and Scopus databases between 2021 and 2024 was analyzed, and the following findings are demonstrated: (1) regulatory requirements emerge across the three dimensions due to sociological factors, with the need for broad-ranging coordination capacities and socio-technical improvements highlighted, (2) while high political–technical capacities are exhibited by regulatory agents in the field of study, significant regulatory challenges persist, complicating the sustainable management of watersheds, and (3) decision-making based on socio-environmental risks is deemed feasible within the field of study, enabling advancements in techno-scientific and socio-political areas, although achieving this is considered challenging. It is concluded that sustainable watershed management can be better understood when the risk-based approach is used as an explanatory framework, particularly in priority areas for addressing—and regulating—the global and local dilemmas involved in governing water resources. As this field has been scarcely examined from this perspective, a series of potential research avenues with substantial scope are faced by the social sciences. Socio-environmental challenges related to water should be rigorously analyzed in future studies through innovative approaches, with the social components of the issue prioritized. Full article

Background: Bone marrow mesenchymal stem cell (BM-MSC) therapy has emerged as a safe and feasible treatment option for patients with knee osteoarthritis (OA). However, the role of adjuvants remains unclear. Our aim was to evaluate the clinical and radiological effects of hyaluronic acid (HA) in comparison to platelet-rich plasma (PRP) as adjuvants to 100 × 10⁶ BM-MSCs in the treatment of knee OA. Methods: We used data from two randomized, parallel-group and controlled clinical trials which tested the efficacy of BM-MSC, previously published in 2016 (Clinical Trials.gov identifier NCT02123368, Nº EudraCT: 2009-017624-72) and 2020 (Clinical Trials.gov identifier NCT02365142. Nº EudraCT: 2011-006036-23). Results: Of the 34 patients included in the study, 24 had received 100 × 10⁶ BM-MSCs plus PRP and 10 had received 100 × 10⁶ BM-MSCs plus HA. On average, BM-MSC plus HA showed a higher improvement in VAS for pain [β-coefficient: −1.25; 95% confidence interval (95% CI):−2.20 to −0.30) than BM-MSC plus PRP (p = 0.01). We also observed that BM-MSC plus HA showed a greater improvement in all the WOMAC subscales scores and in the WOMAC overall score, compared to BM-MSC plus PRP, although these differences were not statistically significant. The Whole-Organ Magnetic Resonance Imaging Score (WORMS) at 12 months was more beneficial with 100 × 10⁶ BM-MSCs plus HA (β-coefficient: −12.61; 95% CI: −19.71, −5.52) than with BM-MSC plus PRP (p = 0.001). Conclusions: The clinical and radiological outcomes after BM-MSC therapy for knee OA could differ according to the adjuvant employed. HA showed greater clinical effectiveness and fewer instances of articular degeneration than PRP as an adjuvant. Full article

Extracellular vesicles (EVs) from Candida albicans can elicit immune responses, positioning them as promising acellular vaccine candidates. We characterized EVs from an avirulent C. albicans cell wall mutant (ecm33Δ) and evaluated their protective potential against invasive candidiasis. EVs from the yeast (YEVs) and hyphal (HEVs) forms of the SC5314 wild-type strain were also tested, yielding high survival rates with SC5314 YEV (91%) and ecm33 YEV immunization (64%). Surprisingly, HEV immunization showed a dual effect, resulting in 36% protection but also causing premature death in some mice. Proteomic analyses revealed distinct profiles among the top 100 proteins in the different EVs, which may explain these effects: a shared core of 50 immunogenic proteins such as Pgk1, Cdc19, and Fba1; unique, relevant immunogenic proteins in SC5314 YEVs; and proteins linked to pathogenesis, like Ece1 in SC5314 HEVs. Sera from SC5314 YEV-immunized mice showed the highest IgG2a titers and moderate IL-17, IFN-γ, and TNF-α levels, indicating the importance of both humoral and cellular responses for protection. These findings highlight the distinct immunogenic properties of C. albicans EVs, suggesting their potential in acellular vaccine development while emphasizing the need to carefully evaluate pathogenic risks associated with certain EVs. Full article

In recent decades, Latin America and the Caribbean region have experienced accelerated aging. However, despite the significant progress of gerontology in the region, the number of geriatricians and professionals trained in the field is low; a notable gap in the training related to the assessment of older adults can also be observed. Therefore, in this literature review, we update the concept of Comprehensive Gerontological Assessment (CGA) for its application in the region. We compile the characteristics, validity, and reliability of CGA tools, and their usage in government documents across countries in the region. We also analyze the adaptations made to CGA during the COVID-19 pandemic, and discuss challenges related to CGA administration, academic training, research, innovation, and management. This study is particularly relevant as it proposes lines of action for decision-makers, academics, researchers, university students, and the general community, which will allow for more tailored interventions aimed at meeting the needs of older adults, their families, and caregivers. Such actions will positively impact functionality, autonomy, and quality of life, while promoting healthy, active, and successful aging in the region. Full article

This research investigates the use of recycled diatomaceous earth (diatomite) from the wine, beer, and oil industries as supplementary cementitious materials in cement-based mixtures. This study aims to reduce embodied energy and promote circular economy practices by incorporating these industrial by-products. The research evaluates the compressive strength, durability, and pozzolanic activity of the mixtures over 7, 28, and 90 days of hydration. The results demonstrate that uncalcined diatoms from wine and oil showed lower compressive strength than natural diatomite, whereas calcination at 500 °C significantly improved performance. Beer diatoms exhibited the lowest mechanical strength because of the organic matter content in their composition. The incorporation of quicklime failed to induce pozzolanic activity in uncalcined diatoms; however, calcination at 500 °C led to improved long-term performance, highlighting the importance of heat treatment for activating diatoms’ pozzolanic properties. This study concludes that recycled diatoms, particularly when calcined, have potential as sustainable cementitious materials. Full article

Background: Quantitative trait loci (QTL) are genomic regions that influence essential traits in livestock. Understanding QTL distribution and density across species’ genomes is crucial for animal genetics research. Objectives: This study explored the QTLome of cattle, pigs, sheep, and chickens by analyzing QTL distribution and evaluating the correlation between QTL, gene density, and chromosome size with the aim to identify QTL-enriched genomic regions. Methods: Data from 211,715 QTL (1994–2021) were retrieved from the AnimalQTLdb and analyzed using R software v4.2.1. Unique QTL annotations were identified, and redundant or inconsistent data were removed. Statistical analyses included Pearson correlations and binomial, hypergeometric, and bootstrap-based enrichment tests. Results: QTL densities per Mbp were 10 for bovine, 4 for pig, 1 for sheep, and 3 for chicken genomes. Analysis of QTL distribution across chromosomes revealed uneven patterns, with certain regions enriched for QTL. Correlation analysis revealed a strong positive relationship between QTL and gene density/chromosome size across all species (p < 0.05). Enrichment analysis identified pleiotropic regions, where QTL affect multiple traits, often aligning with known candidate and major genes. Significant QTL-enriched windows (p < 0.05) were detected, with 699 (187), 355 (68), 50 (15), and 38 (17) genomic windows for cattle, pigs, sheep, and chickens, respectively, associated with overall traits (and specific phenotypic categories). Conclusions: This study provides critical insights into QTL distribution and its correlation with gene density, offering valuable data for advancing genetic research in livestock species. The identification of QTL-enriched regions also highlights key areas for future exploration in trait improvement programs. Full article

Background: Interferons (IFNs) are cytokines involved in the immune response with a synergistic regulatory effect on the immune response. They are therapeutics for various viral and proliferative conditions, with proven safety and efficacy. Their clinical application is challenging due to the molecules’ size, degradation, and pharmacokinetics. We are working on new drug delivery systems that provide adequate therapeutic concentrations for these cytokines and prolong their half-life in the circulation, such as nanoformulations. Methods: Through nanoencapsulation using electrospray technology and biocompatible and biodegradable polymers, we are developing a controlled release system based on nanoparticles for viral infections of the respiratory tract. Results: We developed a controlled release system for viral respiratory tract infections. A prototype nanoparticle with a core was created, which hydrolyzed the polyvinylpyrrolidone (PVP) shell , releasing the active ingredients interferon-alpha (IFN-α) and interferon-gamma (IFN-γ). The chitosan (QS) core degraded slowly, with a controlled release of IFN-α. The primary and rapid effect of the interferon combination ensured an antiviral and immunoregulatory response from day one, induced by IFN-α and enhanced by IFN-γ. The multilayer design demonstrated an optimal toxicity profile. Conclusions: This formulation is an inhaled dry powder intended for the non-invasive intranasal route. The product does not require a cold chain and has the potential for self-administration in the face of emerging viral infections. This novel drug has applications in multiple infectious, oncological, and autoimmune conditions, and further development is proposed for its therapeutic potential. This prototype would ensure greater bioavailability, controlled release, fewer adverse effects, and robust biological action through the simultaneous action of both molecules. Full article

This study examines the link between food deserts and cardiovascular health in older adults in Santiago’s Metropolitan Region, Chile. As the population ages and chronic diseases rise, understanding the impact of food accessibility on health is essential. Using multiscale geographically weighted regression, we analyzed data from the Cardiovascular Health Program, socioeconomic indicators, and food desert maps, sourced from the Chilean Ministry of Health and other databases. Spatial analysis, including Voronoi diagrams, assessed the influence of food deserts on health outcomes. Findings show a significant correlation between limited access to healthy foods and higher cardiovascular disease rates, especially in economically disadvantaged areas. The regression model is significant to contribute to the explanation of disease prevalence, emphasizing the impact of food availability on health. This study highlights the importance of considering spatial factors in urban planning and public health policies. By showcasing the role of food environments in health disparities, it advocates for integrated health interventions. Targeted urban planning to address food deserts can enhance access to healthy foods, improving cardiovascular health and well-being among Santiago’s elderly. The findings provide insights for policymakers to create healthier urban environments and stress the need for sustainable food systems to support public health. Full article

Background/Objectives: The hypercoagulable state associated with COVID-19 infection is associated with adverse outcomes and mortality. Studies have also demonstrated high rates of venous thromboembolism (VTE) events among patients with sepsis. We aimed to evaluate how the increase in thrombotic events in critically ill patients with COVID-19 infection compares to that of critically ill patients with non-COVID-19 sepsis. Methods: A chart review was performed of patients 18 years or older admitted to the intensive care unit (ICU) at Tampa General Hospital between 1 January 2020 and 31 December 2020 diagnosed with COVID-19 or sepsis secondary to other pathogens. Non-COVID-19 sepsis patients and COVID-19 patients were propensity-matched 3:1 on the Charlson Comorbidity Index. Multivariate analyses adjusting for confounding were conducted to report odds ratio (OR) and 95% confidence intervals (95% CIs) of predictors for thrombotic events and overall mortality. Results: After propensity score matching, 492 sepsis patients and 164 COVID-19 patients were included in the analysis. COVID-19 patients were significantly older (p = 0.021) and showed higher BMI (p < 0.001) than sepsis patients. COVID-19 patients did not show significantly higher odds of thrombosis after adjustment for confounders (OR 0.85, 95% CI 0.42–1.72), but had significantly lower odds of mortality than sepsis patients (OR 0.33, 95% CI 0.16–0.66). Conclusions: Our results suggest that further study is required to lower the rate of VTE in COVID-19 and non-COVID-19 sepsis patients admitted to the ICU; it is also reasonable to consider similar thromboembolism practices between these two patient groups. Full article

Aluminum (Al) toxicity and phosphorus (P) deficiency are widely recognized as major constraints to agricultural productivity in acidic soils. Under this scenario, the development of ryegrass plants with enhanced P use efficiency and Al resistance is a promising approach by which to maintain pasture production. In this study, we assessed the contribution of growth traits, P efficiency, organic acid anion (OA) exudation, and the expression of Al-responsive genes in improving tolerance to concurrent low-P and Al stress in ryegrass (Lolium perenne L.). Ryegrass plants were hydroponically grown under optimal (0.1 mM) or low-P (0.01 mM) conditions for 21 days, and further supplied with Al (0 and 0.2 mM) for 3 h, 24 h and 7 days. Accordingly, higher Al accumulation in the roots and lower Al translocation to the shoots were found in ryegrass exposed to both stresses. Aluminum toxicity and P limitation did not change the OA exudation pattern exhibited by roots. However, an improvement in the root growth traits and P accumulation was found, suggesting an enhancement in Al tolerance and P efficiency under combined Al and low-P stress. Al-responsive genes were highly upregulated by Al stress and P limitation, and also closely related to P utilization efficiency. Overall, our results provide evidence of the specific strategies used by ryegrass to co-adapt to multiple stresses in acid soils. Full article