Publicaciones Científicas

Dental caries remains a prevalent chronic disease driven by dysbiosis in the oral biofilm, with Streptococcus mutans playing a central role in its pathogenesis. Objective: This study aimed to assess the effect of D-tagatose on cariogenic risk by analyzing randomized clinical trials (RCTs). Methods: A systematic literature review was conducted targeting RCTs published up to 2024 in eight databases and two gray literature sources. The search strategy utilized Medical Subject Headings (MeSHs) and relevant keywords combined via Boolean operators using the query “Tagatose OR D-tagatose AND Dental Caries”. Eligible studies must evaluate the impact of D-tagatose on cariogenic risk, as indicated by reductions in colony-forming units (CFUs) and improvements in salivary pH levels in treatment groups. Results: From 1139 retrieved records, three studies met the inclusion criteria. These studies consistently demonstrated significant reductions in CFU counts and improvements in salivary pH levels in groups treated with D-tagatose compared to controls using other non-caloric sweeteners or placebos (p < 0.01). However, the quality of the evidence was heterogeneous, with certain methodological concerns. Conclusions: Although the findings suggest potential benefits of D-tagatose in reducing cariogenic risk, limitations such as small sample sizes and variability in study methodologies warrant caution. Further robust investigations are needed to substantiate these promising results and support the integration of D-tagatose into oral care formulations aimed at reducing cariogenic risk.

Introducción: Esta investigación tiene por objetivo analizar las representaciones mediáticas del flaite en los medios de prensa chilenos, a través de una revisión documental de dos años. Metodología: se analizó el total de las 123 noticias relacionadas a este término publicadas en los portales electrónicos de los medios de prensa chilenos entre abril del 2022 y marzo del 2024. La técnica de análisis de contenido fue el análisis categorial temático, construyendo categorías que permitieron sistematizar y categorizar la información recolectada. Resultados: la figura del flaite es estigmatizada en más de la mitad de las noticias analizadas, asociándolo principalmente a noticias con una connotación negativa. Conclusiones: El asociar la pobreza, juventud y marginalidad a un término como el flaite, resulta en un trato desigual por parte de los medios y en la exclusión de las personas estigmatizadas bajo este término, de ciertos derechos y oportunidades.

Introducción: La enfermedad de Parkinson es una afección neurológica progresiva caracterizada por la lentitud y la escasez de movimientos (bradicinesia), rigidez muscular, temblores en reposo y trastorno de la postura. Entre el período 1990-2016, las muertes atribuidas a enfermedad de Parkinson aumentaron en 16,5% y la prevalencia en 19,9%, situando a Chile como el país latinoamericano que registra el mayor aumento en la prevalencia de esta patología. Método: Se presenta estudio de carácter cuantitativo, observacional, descriptivo, ecológico y longitudinal retrospectivo relacionado a los ingresos de pacientes con un diagnóstico previo confirmado de enfermedad de Parkinson, con el objetivo general de describir los motivos de ingresos hospitalarios en pacientes con enfermedad de Parkinson en el Hospital Clínico Herminda Martín, Chillán, Chile, durante el período 2017–2021 a través de la descripción de esta población y sus complicaciones más frecuentes. Resultados y Conclusiones: La edad de presentación de complicaciones que requieren hospitalización más frecuente fue entre los 70 y 90 años, teniendo una distribución hombre: mujer de 3:2. La mediana de la duración de las hospitalizaciones fue de 8 días y el año en el que se presentaron mayor número de ingresos fue el 2019, con un 24% de los pacientes ingresados durante el período de estudio. En cuanto a los motivos de ingreso hospitalario más frecuente en pacientes con enfermedad de Parkinson fueron enfermedades cardiovasculares (30,2%), traumatismos (17,7%), descompensaciones de la enfermedad (10,4%), trastornos del tracto gastrointestinal (10,4%), neoplasias (8,3%), trastornos genitourinarios (8,3%), manifestaciones del sistema nervioso central no párkinson (7,3%), infecciones (3,1%) y Otros no clasificables (5%).

Ischaemic stroke is a leading cause of death and disability. Circulating extracellular vesicles (EVs) post-stroke may help brain endothelial cells (BECs) counter ischaemic injury. However data on how EVs from ischaemic stroke patients, considering injury severity, affect these cells are limited. The aims were to characterize the inflammatory and angiogenic components of circulating EVs in acute ischaemic stroke patients, considering stroke severity, and to investigate whether these circulating EVs differentially influence the proangiogenic properties and blood–brain barrier (BBB) integrity of human BECs. Eighteen ischaemic stroke patients (acute phase: 24–48 h) and nine controls matched by age, sex, and blood pressure were studied. Stroke severity was classified as severe (n = 9) or mild (n = 9). Plasma EVs were analysed for size, concentration, and protein markers (CD63, Alix, CD81, TSG101, HSP70), as well as proinflammatory and angiogenic proteins. EV uptake, cell viability, proangiogenic capacity, electrical resistance [TEER (transendothelial electrical resistance)], and dextran-70 kD permeability were assessed using human brain microvascular endothelial cells (hCMEC/D3). Stroke patients had lower EV concentrations than controls (p = 0.075), with mild-stroke patients having the smallest EVs. Stroke-derived EVs had higher levels of interleukin 6 (IL-6), tumour necrosis factor α (TNF-α), nitrotyrosine, and vascular endothelial growth factor (VEGF) but lower placental growth factor (PLGF) compared to controls. IL-6 was higher in mild strokes (p = 0.0025), and VEGF was higher in severe strokes (p = 0.048). EVs from severe-stroke cases enhanced proangiogenic capacity and minimally disrupted the BBB. Stroke severity influences EV number, size, and composition. EVs from severe strokes may promote BBB restoration and cerebral angiogenesis, suggesting their role in intercellular communication and homeostasis in ischaemic tissue. Key points - Ischaemic stroke is one of the leading causes of death worldwide. After an ischaemic stroke several physiological processes are triggered to recover the injured tissue. - Increasing evidence has suggested that extracellular vesicles (EVs) present in the bloodstream could play a role in brain recovery, but their specific impact, especially concerning stroke severity, was unclear. - This study demonstrates that plasma-derived EVs from first-ever ischaemic stroke patients have distinctive characteristics and effects over brain angiogenesis and blood–brain barrier (BBB) integrity. - Our study proposes that circulating EVs from patients with severe stroke may carry protective factors to initiate brain endothelial cell recovery after acute episodes. - These findings underscore the role of EVs as potential effectors of BBB recovery and biomarkers in severe ischaemic stroke.

Objective The inflammatory responses from synovial fibroblasts and macrophages and the mitochondrial dysfunction in chondrocytes lead to oxidative stress, disrupt extracellular matrix (ECM) homeostasis, and accelerate the deterioration process of articular cartilage in osteoarthritis (OA). In recent years, it has been proposed that mesenchymal stromal cells (MSC) transfer their functional mitochondria to damaged cells in response to cellular stress, becoming one of the mechanisms underpinning their therapeutic effects. Therefore, we hypothesize that a novel cell-free treatment for OA could involve direct mitochondria transplantation, restoring both cellular and mitochondrial homeostasis. Methods Mitochondria were isolated from Umbilical Cord (UC)-MSC (Mito-MSC) and characterized based on their morphology, phenotype, functions, and their ability to be internalized by different articular cells. Furthermore, the transcriptional changes following mitochondrial uptake by chondrocytes were evaluated using an Affymetrix analysis, Lastly, the dose dependence therapeutic efficacy, biodistribution and immunogenicity of Mito-MSC were assessed in vivo, through an intra-articular injection in male C57BL6 mice in a collagenase-induced OA (CIOA) model. Results Our findings demonstrate the functional integrity of Mito-MSC and their ability to be efficiently transferred into chondrocytes, synovial macrophages, and synovial fibroblasts. Moreover, the transcriptomic analysis showed the upregulation of genes involved in stress such as DNA reparative machinery and inflammatory antiviral responses. Finally, Mito-MSC transplantation yielded significant reductions in joint mineralization, a hallmark of OA progression, as well as improvements in OA-related histological signs, with the lower dose exhibiting better therapeutic efficacy. Furthermore, Mito-MSC was detected within the knee joint for up to 24 h post-injection without eliciting an inflammatory response in CIOA mice. Conclusion Collectively, our results reveal that mitochondria derived from MSC are transferred to key articular cells and are retained in the joint without generating an inflammatory immune response mitigating articular cartilage degradation in OA, probably through a restorative effect triggered by the stress antiviral response within OA chondrocytes.

El objetivo de esta investigación fue identificar las formas en que la crisis provocada por la pandemia del Covid 19 impactó en los sistemas de gestión de comunicación interna de crisis en empresas de Ecuador, Colombia y Chile, y vislumbrar las enseñanzas que este proceso dejó para las organizaciones. Para ello, se aplicó una metodología cualitativa mediante el uso de entrevistas semiestructuradas a 11 jefes de comunicación de las empresas en estudio. Los hallazgos mostraron que las empresas abordaron sus sistemas de comunicaciones internas de manera más estratégica con el doble objetivo de salvar vidas y mantener en funcionamiento a sus organizaciones. A través de la comunicación interna estratégica de crisis como subsistema de comunicación organizacional, las empresas no solo mostraron una gran capacidad de adaptación tecnológica en el uso de los canales de comunicación, sino también una mayor integración entre sus esfuerzos de comunicación organizacional para construir confianza con sus públicos clave y salvaguardar su reputación durante la pandemia. Las lecciones de la gestión de crisis en este periodo posibilitan a los gerentes y encargados de comunicación establecer estrategias para afrontar futuras crisis como parte de su aprendizaje organizacional y mejoramiento continuo.

Wetlands occupy a small percentage of the Earth's surface but provide essential ecosystem services, such as water regulation, carbon cycling and habitat support. Patagonian “Vegas” are unique wetland ecosystems characterised by their groundwater recharge and hydrological dynamics, distinct from the surrounding steppe. These ecosystems play a critical role in supporting livestock with up to six times the forage productivity of the surrounding steppe and in storing over 69 g kg−1 of organic carbon. However, the influence of soil structure parameters (e.g., pore size distribution, bulk density) and soil shrinkage behaviour on soil moisture variability and ecosystem functions in Patagonian wetlands remains poorly understood. This study aimed to assess the physical capacity and intensity parameters of soils, including shrinkage properties, within a micro-watershed in southern Patagonia. Our findings reveal significant spatial variability in soil properties, with bulk density (BD) ranging from 0.12 to 1.81 Mg m−3 across topographic positions. Mineral soils on summits and footslopes exhibited high macroporosity (up to 18.1% of total pore volume at 5 cm depth), which facilitates water movement, while organic soils in the Vega centre had a higher total porosity (up to 88.8%) that enhances water and air retention. The coefficient of linear extensibility (COLE) for organic soils reached a level of 0.078, indicating a high shrinkage capacity. This shrinkage influenced the functionality of the porous system, shifting pore roles between air conduction and water storage as larger pores contracted. These dynamics, driven by climate change and increased drying cycles, may lead to significant shifts in soil functionality and ecosystem resilience. Enhanced understanding of soil physical states and their response to environmental changes can support sustainable management strategies, benefiting local agriculture and preserving these critical ecosystems.

Intersexuality is a reproductive phenomenon that occurs in some gonochoric species and refers to the simultaneous presence of both male and female gametes within the same individual. Although this phenomenon has been reported in various invertebrate species, many aspects remain poorly understood, especially in marine mussels. However, it has been suggested that the prevalence of parasites within populations could induce the occurrence of intersex animals. We studied intersexuality in the marine mollusk Perumytilus purpuratus, a key species of the rocky intertidal zone on the southeastern coast of the Pacific Ocean. A total of 6472 mussels from eight locations in northern and southern Chile were analyzed. We estimated the size of the specimens, the sex ratio of the population, and the prevalence of parasites. Additionally, we examined the germ cells of intersex mussels. The results showed that the male-to-female sex ratio (1:1) was maintained in the populations. Intersex mussels were found in six of the eight locations, representing 0.19% of the mussels analyzed. However, no parasites were found in the intersex animals. Additionally, the abundance of intersex individuals was not correlated with parasitism levels in the population. In intersex mussels, the gonadal tissue was compartmentalized, with male and female germ cells remaining separate. It is concluded that intersexuality in Perumytilus purpuratus is a low-frequency reproductive phenomenon, likely resulting from an alteration in the sex determination mechanism. Intersexuality offers a valuable opportunity to explore the biological aspects of sex determination in mussels. Therefore, further research in this area should be pursued.

This exploratory case study investigates the emotional responses, professional accountability, and action-taking dispositions of 150 Chilean prospective English as a Foreign Language (EFL) teachers towards language assessment scenarios. Despite the growing interest in assessment, little research has focused on the affective experiences of trainee teachers. Participants completed the Emotionally Loaded Situations Questionnaire, which assessed their reactions to situations where students fail language assessments. The study reveals that these situations elicited negative emotional responses, leading to a diminished sense of teacher identity due to perceived inefficiencies in teaching and assessment practices. The findings also highlight the teachers’ dispositions towards taking corrective actions, such as revisiting teaching and assessment strategies, reinforcing assessment content, and improving future practices. As to professional accountability, trainee teachers acknowledge that their teaching performance has a direct effect on their students’ assessment results. These outcomes emphasize the need for further research on the affective dimension in language assessment to better support the professional development of future teachers.

The Bío Bío River is the second largest river in Chile considering both discharge and length. The Bío Bío River flows through the second most important economical centre in Chile and it has been recently classified as one of the world's largest river systems strongly affected by fragmentation and change in flow regime, mainly due to hydropower and irrigation. The cities of Hualqui, Chiguayante, Concepción, Hualpén, and San Pedro de la Paz are located along the last 25 km of its course, and are exposed to a high flood risk due to a combination of increasing rainfall storms and the dams operation located in the upper basin. This work assessed several structural and non-structural flood defence alternatives for the lower 25 km of the river. A one-dimensional (1D) hydraulic model was used under different discharge scenarios. The results showed that storage areas and diversion canals located along the lower part of the Bío Bío River did not prove to be a suitable solution. Nevertheless, it was found that the most effective alternative implies a reservoir operation focused on storing the extra water produced by the incoming flood. Conclusions support the materialization of reservoir emergency operation protocols, as indicated in the Reglamento de Ley N°20.304, approved by Decreto de Ley 138, Chile.