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The most abundant N6-methyladenosine (m6A) modification on mRNAs is installed non-stoichiometrically across transcripts, with 5' untranslated regions (5' UTRs) being the least conductive. 5' UTRs are essential for translation initiation, yet the molecular mechanisms orchestrated by m6A remain poorly understood. Here, we combined structural, biochemical, and single-molecule approaches and show that at the most common position, a single m6A does not affect translation yields, the kinetics of translation initiation complex assembly, or start codon recognition both under permissive growth and following exposure to oxidative stress. Cryoelectron microscopy (cryo-EM) structures of the late preinitiation complex reveal that m6A purine ring established stacking interactions with an arginine side chain of the initiation factor eIF2α, although with only a marginal energy contribution, as estimated computationally. These findings provide molecular insights into m6A interactions with the initiation complex and suggest that the subtle stabilization is unlikely to affect the translation dynamics under homeostatic conditions or stress.
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Adenosina/análogos & derivados , Iniciación de la Cadena Peptídica Traduccional , Biosíntesis de Proteínas , Regiones no Traducidas 5' , Microscopía por Crioelectrón , ARN Mensajero/genética , ARN Mensajero/metabolismo , Codón Iniciador/genéticaRESUMEN
Cognitive accessibility aims to make content more accessible for people with cognitive impairments, such as the elderly and people with intellectual and learning disabilities. In this sense, it is possible to design an accessible user interface from a cognitive point of view. As a contribution, this article presents cognitive accessibility design patterns and their application in designing the Easier web system's user interface. The Easier web system provides a tool that assists in the understanding and readability of text content geared towards people with intellectual disabilities. It detects complex words and offers easier replacements and other resources such as a definition of the complex word. In addition to applying the design patterns, user tests with people with intellectual disabilities and older people have been carried out to evaluate the cognitive accessibility of the Easier system's interface. The results indicate that people with cognitive impairments know how to use the interfaces and have a satisfactory experience. In addition, a design proposal to provide a glossary mechanism to be used in web interfaces with simplified texts is presented and validated.
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BACKGROUND: Extravillous trophoblasts (EVTs) form stratified columns at the placenta-uterus interface. In the closest part to fetal structures, EVTs have a proliferative phenotype, whereas in the closest part to maternal structures, they present a migratory phenotype. During the placentation process, Connexin 40 (Cx40) participates in both the proliferation and migration of EVTs, which occurs under hypoxia. However, a possible interaction between hypoxia and Cx40 has not yet been established. METHODS: We developed two cellular models, one with "low Cx40" (Jeg-3), which reflected the expression of this protein found in migratory EVTs, and one with "high Cx40" (Jeg-3/hCx40), which reflected the expression of this protein in proliferative cells. We analyzed the migration and proliferation of these cells under normoxic and hypoxic conditions for 24 h. Jeg-3 cells under hypoxia increased their migratory capacity over their proliferative capacity. However, in Jeg-3/hCx40, the opposite effect was induced. On the other hand, hypoxia promoted gap junction (GJ) plaque formation between neighboring Jeg-3 cells. Similarly, the activation of a nitro oxide (NO)/cGMP/PKG-dependent pathway induced an increase in GJ-plaque formation in Jeg-3 cells. CONCLUSIONS: The expression patterns of Cx40 play a crucial role in shaping the responses of EVTs to hypoxia, thereby influencing their migratory or proliferative phenotype. Simultaneously, hypoxia triggers an increase in Cx40 gap junction (GJ) plaque formation through a pathway dependent on NO.
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Hipoxia de la Célula , Movimiento Celular , Proliferación Celular , Conexinas , Proteína alfa-5 de Unión Comunicante , Uniones Comunicantes , Trofoblastos , Trofoblastos/metabolismo , Humanos , Uniones Comunicantes/metabolismo , Conexinas/metabolismo , Femenino , Embarazo , Línea Celular , Modelos Biológicos , Trofoblastos ExtravellososRESUMEN
Thanks to technologies such as the Internet and devices now available to people, we have increasingly greater access to larger quantities of information. However, people with ageing disabilities or intellectual disabilities, non-native speakers, and others have difficulties reading and understanding information. For this reason, it is essential to provide text simplification mechanisms when accessing information. Natural Language Processing methods can be applied to simplify textual content and improve understanding. These methods often use machine learning algorithms and models which require resources, such as corpora, to be trained and tested. This article presents the EASIER corpus, a resource that can be used to build lexical simplification methods to process Spanish domain-independent texts. The EASIER corpus is composed of 260 annotated documents with 8,155 words labelled as complex and 5,130 words with at least one proposed context-aware synonym associated. Expert linguists in easy-to-read and plain language guidelines have annotated the corpus based on their experience adapting texts for people with intellectual disabilities. Sixteen annotation guidelines that discriminate between complex and simple words have been defined to help other groups of experts to generate new annotations. Additionally, an inter-annotator agreement test was performed to validate the corpus, obtaining a Fleiss Kappa coefficient of 0.641. Furthermore, a qualitative evaluation was conducted with 45 users (including people with intellectual disabilities, elderly people, and a control audience). Complex word identification tasks achieved moderate results, but the synonyms proposed to replace complex words achieved almost perfect ratings. This resource has been integrated into the EASIER platform, a tool that helps people with cognitive impairments and intellectual disabilities to read and understand texts more easily.
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Disfunción Cognitiva , Discapacidad Intelectual , Humanos , Anciano , Semántica , Lenguaje , Algoritmos , Procesamiento de Lenguaje NaturalRESUMEN
Between 2012 and 2014, 715 green coffee samples were gathered by Almacafé S.A. (Bogotá, Colombia) from 27 countries. These were analysed at the nuclear magnetic resonance (NMR) laboratory at Universidad del Valle (Cali, Colombia). Over 1000 methanolic coffee extracts were prepared and 4563 spectra were acquired in a fully automatic manner using a 400 MHz NMR spectrometer (Bruker Biospin, Germany). The dataset spans the variance that could be expected for an industrial application of origin monitoring, including samples from different harvest times, collected over several years, and processed by at least two distinct operators. The resulting 1D and 2D spectra can be used to develop and evaluate feature extraction methods, multivariate algorithms, and automation monitoring techniques. They can also be used as datasets for teaching, or as a reference for new studies of similar samples and approaches.
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The ongoing COVID-19 pandemic has already affected more than 300 million people worldwide. Medical imaging shortage affects an estimated of 4 billion people, especially in rural and remote areas (RAs), limiting diagnostic assessment of respiratory illness. Lung ultrasound imaging (LUS) together with volume sweep imaging (VSI) acquisition protocols have been successfully piloted as a solution for lung screening in RAs eliminating the need for trained operators and on-site radiologists. Nevertheless, this protocol requires the acquisition of 12 videos for 6 areas with both longitudinal and transverse positions of the transducer. Nonetheless, bandwidth limitations can hamper the transmission of these videos for remote interpretation. This work aimed to developed a stitching algorithm capable of generating a panoramic reconstruction of LUS cine clips. The results show reconstructions with minimal loss of information as 92.5% of the panoramic images conserved the presence of A-lines. These results show that LUS can be represented as an image without significantly compromising its quality. This can be useful to overcome bandwidth issues as well as improve the time on lung assessment of the patient.
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COVID-19 , Pandemias , COVID-19/diagnóstico por imagen , Diagnóstico por Imagen , Humanos , Pulmón/diagnóstico por imagen , UltrasonografíaRESUMEN
The aim of the research is to determine the trends and challenges related to sports medicine practices in Chilean athletic training. This research examines the state of sports medicine practices in the field of athletic training in Chile, taking a close expression at both international trends and regionally-specific issues. To determine the research, smart PLS software was used and generated informative results, including descriptive statistics and correlation coefficient analysis, which also explains the smart PLS Algorithm model between them. Global trends include the integration of cutting-edge technologies, customized training programs, and an all-encompassing, interdisciplinary approach; however, for successful implementation in Chile, issues including scarce resources, educational disparities, cultural influences, infrastructure needs, and legal considerations must be resolved. The overall research found that direct and significant implementation of sports medicine practices in Chilean athletic training. The study highlights how crucial it is to comprehend and overcome these obstacles to maximize athlete performance and well-being. Sports medicine practices in Chile can progress by practitioners and stakeholders recognizing and adjusting tothe distinct features of the nation's sports ecosystem (AU)
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Humanos , Medicina Deportiva/tendencias , Atletas , Algoritmos , ChileRESUMEN
Resumen El artículo presenta en líneas generales la configuración epistemológica de la bioética, fundamental para determinar su campo y modo de conocimiento. Mediante la revisión teórica, se presenta la conceptualización de la ética, de la bioética como una ética aplicada y el desarrollo de la bioética desde su concepción inicial y su pronto reduccionismo, hasta la ampliación y construcción de una extensa y contextualizada perspectiva latinoamericana, que extiende su campo de estudio y acción desde las cuestiones individuales hasta las colectivas, priorizando temas como la localización de los recursos en salud, la exclusión social, la equidad y las formas de discriminación. Este desarrollo, campo y objeto de estudio tiene como base de sustentación el Estatuto epistemológico de la bioética (en su versión en español), las Bases conceituais da bioética-enfoque latino-americano (en portugués), de la Red Latinoamericana y del Caribe de Bioética, y la Declaración Universal de Bioética y Derechos Humanos de la Unesco, instrumento que ayudó para la ampliación del referencial conceptual de la disciplina en la que se incorpora lo social, lo sanitario y lo medioambiental.
Abstract The article presents in general terms the epistemological configuration of bioethics, which is essential to determine its field and mode of knowledge. The theoretical revision presents the conceptualization of ethics, of bioethics as an applied ethics and the development of bioethics from its initial conception and its early reductionism, to the expansion and construction of a broad and contextualized Latin American perspective, which extends its field of study and action of individual issues to collective issues, prioritizing issues such as location of resources in health, social exclusion, equity, and forms of discrimination. This development, field and object of study is based on the Epistemological Statute of Bioethics (in its spanish version) and Bases Conceptual da Bioethics - Latin American approach (in Portuguese), of the Latin American and Caribbean Network of Bioethics and Unesco, Universal Declaration of Bioethics and Human Rights, an instrument that helped to broaden the conceptual framework of the discipline in which social, health, and environmental aspects are incorporated.
Resumo O artigo apresenta em linhas gerais a configuração epistemológica da Bioética, essencial na determinação do seu campo e modo de conhecimento. Através da revisão teórica, apresenta-se a conceptualização da ética, da bioética como uma ética aplicada e o desenvolvimento da bioética a partir da sua concepção inicial e seu cedo reducionismo, até à expansão e construção de uma ampla e contextualizada perspectiva latino-americana, que estende o seu campo de estudo e ação a partir das questões individuais ate as coletivas, priorizando questões como a alocação dos recursos em saúde, a exclusão social, a equidade e as formas de discriminação. Este desenvolvimento, campo e objeto de estudo têm como base de sustentação o Estatuto epistemológico da bioética, (em sua versão em espanhol), as Bases conceituais da bioética-enfoque latino-americano (em Português), da Rede Latino-americana e do Caribe de Bioética, e a Declaração Universal de bioética e Direitos Humanos da Unesco, um instrumento que ajudou a expandir o referencial conceitual da disciplina na qual se incorpora as questões meio ambientais, sociais, e de saúde.
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Humanos , Bioética , Conocimiento , Historia , América LatinaRESUMEN
El objetivo del siguiente estudio fue determinar las dimensiones del tórax y su relación con la función ventilatoria en un grupo de nadadores correspondientes a la selección de natación de la Universidad Católica del Maule. Se evaluaron 42 sujetos de sexo masculino entre 18 y 26 años, 18 seleccionados de natación y 24 estudiantes sedentarios, todos de la Universidad Católica del Maule. Se les realizó antropometría corporal básica (peso y talla corporal) y específica de tórax, diámetro antero-posterior (DAT) y transverso (DTT) de tórax y perímetro mesoesternal (PME). Posterior a esto, se evaluó la función ventilatoria a través de pletismografía corporal. Para el análisis estadístico se determinó la normalidad de los datos posteriormente se utilizó t de student o U de Mann-Whitney y Pearson o Spearman según correspondiera, para establecer significancia estadística o correlación, respectivamente. Se consideró un nivel de significancia estadística de p<0,05. Se observó un aumento significativo del índice de masa corporal (IMC), mayores dimensiones de tórax en nadadores, DAT a capacidad pulmonar total (CPT) y PME a CPT y volumen residual (VR). En función ventilatoria existió un aumento significativo de presión espiratoria máxima (PEM), presión inspiratoria máxima (PIM), capacidad inspiratoria (CI) y CPT. También se observaron correlaciones de buenas a excelentes entre diámetro y perímetro de tórax con CI y CPT en los nadadores. Por tanto, se concluye que existió una relación entre la antropometría de tórax y la función ventilatoria en nadadores de la Universidad Católica del Maule.
The main point of this study is to determine the dimensions of the thorax and its relation to the ventilatory function of a group of swimmers members of the swimming team at Universidad Católica del Maule. 42 male subjects, whose age vary between 18 and 26 years old, were evaluated. 18 subjects were on the swimming team and 24 were sedentary students, all of them study in Universidad Católica del Maule. They were performed a basic bodily anthropometry assessment (weight and body size) and they were also performed a specific anthropometric assessment of the thorax, as well as one of the anteroposterior diameter (ATD) and the transverse diameter (TDT), thorax and the mesosternal perimeter (MP). Finally, they were performed an evaluation of the ventilatory function trough body plethysmography. For the statistical analysis the normality of the data was determined, then came the use of t of student or U of Mann-Whitney and Pearson or Spearman, depending of the case, whether it was to determine the statistical significance or correlation, respectably. A level of statistical significance of p> 0,05 was considered. A significant increase of the body mass index (BMI) was observed, bigger thorax dimensions, PDA to full pulmonary capacity (FPC) and PME to FPC and residual volume. In the ventilatory function there was a significant increase of maximal expiratory pressure (MEP), maximal inspiratory pressure (MIP), inspiratory capacity (IC) and FPC. There were also correlations that vary from good to excellent between the diameter and perimeter of the thorax and IC and FMP, among the swimmers. Thus, it is concluded that relations exist between the anthropometrical of the thorax and the ventilatory function in swimmers of the Universidad Católica del Maule, Talca, Chile.
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Humanos , Masculino , Adolescente , Adulto , Adulto Joven , Antropometría , Pulmón/fisiología , Natación , Tórax/anatomía & histología , Capacidad VitalRESUMEN
El artículo analiza la crisis del sistema de salud colombiano sometido al modelo de economía de mercado con regulación estatal a partir de la Ley 100 de 1993. Su interés se centra en reflexionar sobre la concepción que el modelo da al gasto en salud como una inversión sometida a las fuerzas del mercado y consecuencialmente, con una tasa de rentabilidad esperada. Mediante el análisis de estadísticas oficiales y de encuestas de satisfacción de los usuarios se devela la crisis estructural que padece la prestación del servicio de salud pública como un sistema, involucrando variables económicas, políticas y sociales. La interdisciplinariedad del abordaje temático del estudio permite profundizar en el análisis desde la reflexión de los valores morales y éticos que debe acompañar la asistencia sanitaria, al igual que la visión económica de su administración. Bioética, salud y economía constituyen descriptores fácticos de un sistema en crisis estructural que alimenta la patología social de la pobreza (AU)
The article analyzes the crisis of the Colombian health system subject to market economy model with state regulation from the Law 100 of 1993. Its focus is to reflect on the concept that the model gives health expense as an investment subject to market forces and consequentially, with an expected rate of return. By analyzing official statistics and surveys of user satisfaction structural crisis affecting the provision of public health as a system, involving economic, political and social variables debela. The interdisciplinary approach to the study theme allows further analysis from the reflection of the moral and ethical values that should accompany the health care, as well as the economic vision of his administration. Bioethics, health and economy are factual descriptors of a system in structural crisis that fuels the social pathology of poverty (AU)
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Humanos , Sistemas de Salud/organización & administración , Salud Pública/tendencias , /organización & administración , Colombia , Modelos Organizacionales , 16672 , Economía Hospitalaria , PobrezaRESUMEN
A través del artículo se presenta el reduccionismo del que la disciplina de la Bioética ha sido objeto. Es por esta razón y para contribuir a vislumbrar el magnífico campo objeto de ella, que se hace mención de su carácter holístico y general. Aspectos de estudio intrínsecos desde su mismo fundador, y hoy insustituibles por la crisis generada por la intervención negativa del ser humano y por su negligencia en la ejecución de soluciones. Así mismo, y como un aporte fundamental al tema en cuestión, se presenta el objeto de estudio de la Bioética en Latinoamérica, con su desarrollo, su campo y su objeto de estudio propio. Se da paso entonces a la simbiosis o relación estrecha que tiene la Bioética con los Derechos Humanos, representada de una manera particular en La Declaración Universal sobre Bioética y Derechos Humanos aprobada por la UNESCO y, de donde se puede inferir uno de los aspectos fundamentales objeto de estudio de la Bioética latinoa¬mericana como es la parte social. Finalmente, se da paso al interesante y necesario aspecto de la enseñanza de la Bioética en los futuros profesionales como un aporte de la función y proyección social de la universidad...
Throughout the article the reductionism that discipline of bioethics has been. For this reason and to contribute to glimpse the object of her magnificent course that mentions its holistic and comprehensive. Intrinsic aspects of study from its founder, and now irreplaceable for the crisis caused by the negative intervention of human beings and for their negligence in implementing solutions. Also, as a fundamental contribution to the subject matter, we present the object of study of bioethics in Latin America, with its development, field and object of study. It then leads to symbiosis or close relationship has bioethics to Human Rights, represented in a particular way in the Universal Declaration on Bioethics and Human Rights adopted by UNESCO, and from which we can infer fundamental aspect object study of Latin American bioethics as is the social part. Eventually leads to the interesting aspect of bioethics education of future professionals as a contribution to the social function of the university...
Este artigo apresenta o reducionismo ao qual vem sendo objeto a disciplina da Bioética. É por esta razão, e con¬tribuindo para a visão do magnífico campo de seu objetivo, que se menciona seu caráter holístico e geral. Aspectos intrínsecos de estudo a partir do seu próprio fundador, e hoje insubstituíveis pela crise gerada com a intervenção negativa do ser humano e por sua negligencia na execução de soluções. Da mesma forma, e como uma contribuição fundamental ao tema em questão, é apresentado o objeto de estudo da Bioética na América Latina, com seu desen¬volvimento, campo e objetivo de estudo próprio. Passa-se então à simbiose ou estreita relação da Bioética com os Direitos Humanos, representada de maneira particular na Declaração Universal sobre Bioética e Direitos Humanos aprovada pela UNESCO, de onde se pode inferir um dos aspectos fundamentais objeto de estudo da Bioética latino¬-americana, que é a parte social. Finalmente, aborda o interessante e necessário aspecto do ensino da Bioética aos futuros profissionais, como uma contribuição da função e projeção social da universidade...
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Humanos , Bioética , Ética Profesional , Derechos Humanos , Enseñanza , UNESCORESUMEN
Astrocytes and microglia associate to amyloid plaques, a pathological hallmark of Alzheimer disease. Microglia are activated by and can phagocytose beta-amyloid (Abeta). Scavenger receptors (SRs) are among the receptors mediating the uptake of fibrillar Abeta in vitro. However, little is known about the function of the astrocytes surrounding the plaques or the nature of their interaction with Abeta. It is unknown whether glial cells bind to nonfibrillar Abeta and if binding of astrocytes to Abeta depends on the same Scavenger receptors described for microglia. We determined the binding of glia to Abeta by an adhesion assay and evaluated the presence of scavenger receptors in glial cells by immunocytochemistry, immunohistochemistry of brain sections, and immunoblot. We found that astrocytes and microglia from neonatal rats adhered in a concentration-dependent manner to surfaces coated with fibrillar Abeta or nonfibrillar Abeta. Fucoidan and poly(I), known ligands for SR-type A, inhibited adhesion of microglia and astrocytes to Abeta and also inhibited Abeta phagocytosis. In contrast, a ligand for SR-type B like low density lipoprotein, did not compete glial adhesion to Abeta. Microglia presented immunodetectable SR-BI, SR-AI/AII, RAGE, and SR-MARCO (macrophage receptor with collagenous structure, a member of the SR-A family). Astrocytes presented SR-BI and SR-MARCO. To our knowledge, this is the first description of the presence of SR-MARCO in astrocytes. Our results indicate that both microglia and astrocytes adhere to fibrillar and nonfibrillar Abeta. Adhesion was mediated by a fucoidan-sensitive receptor. We propose that SR-MARCO could be the Scavenger receptor responsible for the adhesion of astrocytes and microglia to Abeta.
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Péptidos beta-Amiloides/química , Astrocitos/citología , Microglía/metabolismo , Neuroglía/metabolismo , Receptores Inmunológicos/biosíntesis , Adenosina Trifosfato/química , Animales , Animales Recién Nacidos , Astrocitos/metabolismo , Unión Competitiva , Antígenos CD36 , Adhesión Celular , Línea Celular Tumoral , Membrana Celular/metabolismo , Supervivencia Celular , Relación Dosis-Respuesta a Droga , Humanos , Immunoblotting , Inmunohistoquímica , Queratinas/metabolismo , Ligandos , Microscopía Fluorescente , Péptidos/química , Fagocitosis , Fosforilación , Proteína Quinasa C/metabolismo , Ratas , Receptores Inmunológicos/metabolismo , Receptores Depuradores , Receptores Depuradores de Clase A , Receptores Depuradores de Clase B , Estrés MecánicoRESUMEN
Blood acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities have been studied as markers for Alzheimer's disease (AD), but their usefulness as a disease marker is controversial. To determine cholinesterase (ChE) activity during AD progression and whether ChE changes associate to other dementias, ChE activity was measured in lymphocytes, erythrocytes and platelets. Subjects underwent extensive medical and neuropsychological examination. Both early-AD and AD patients had lower AChE activity in lymphocytes compared to control subjects (p < 0.0001). In contrast, erythrocyte AChE activity was higher in patients with vascular dementia (p = 0.004). Low ChE activity in lymphocytes was the best discriminator for AD. Because it was already low at very early stages of AD, ChE could be helpful as an early biomarker of differential diagnosis for the follow-up of patients during their early stages of cognitive impairment before a clinical dementia is established.
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Enfermedad de Alzheimer/sangre , Colinesterasas/sangre , Demencia Vascular/sangre , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/diagnóstico , Encéfalo/diagnóstico por imagen , Butirilcolinesterasa/sangre , Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/epidemiología , Trastornos del Conocimiento/etiología , Demencia Vascular/complicaciones , Demencia Vascular/diagnóstico , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Índice de Severidad de la Enfermedad , Tomografía Computarizada por Rayos XRESUMEN
Research on Alzheimer's disease (AD) focuses mainly on neuronal death and synaptic impairment induced by beta-Amyloid peptide (Abeta), events at least partially mediated by astrocyte and microglia activation. However, substantial white matter damage and its consequences on brain function warrant the study of oligodendrocytes participation in the pathogenesis and progression of AD. Here, we analyze reports on oligodendrocytes' compromise in AD and discuss some experimental data indicative of Abeta toxicity in culture. We observed that 1 microM of fibrilogenic Abeta peptide damages oligodendrocytes in vitro: while pro-inflammatory molecules (1 microg/ ml LPS + 1 ng/ml IFNgamma) or the presence of astrocytes reduced the Abeta-induced damage. This agrees with our previous results showing an astrocyte-mediated protective effect over Abeta-induced damage on hippocampal cells and modulation of the activation of microglial cells in culture. Oligodendrocytes protection by astrocytes could be, either by reduction of Abeta fibrilogenesis/deposition or prevention of oxidative damage. Likewise, the decrease of Abeta-induced damage by proinflammatory molecules could reflect the production of trophic factors by activated oligodendrocytes and/or a metabolic activation as observed during myelination. Considering the association of inflammation with neurodegenerative diseases. oligodendrocytes impairment in AD patients could potentiate cell damage under pathological conditions.
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Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/fisiología , Astrocitos/metabolismo , Oligodendroglía/metabolismo , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Animales , Muerte Celular , Células Cultivadas , Humanos , Inflamación/metabolismo , RatasRESUMEN
BACKGROUND: Maternal omega-3 fatty acid supplementation has been suggested to provide docosahexaenoic acid (DHA) for the normal brain development during gestation. DHA can be given as such (preformed) or through the omega-3 precursor alpha-linolenic acid (LNA) which is transformed into DHA by elongation and desaturation reactions. Western diet provides low amounts of LNA and DHA; therefore, supplementation with these omega-3 fatty acids has been suggested for pregnant women. However, the bioequivalence of LNA ingestion to DHA supplementation has not been established. METHODS: Recently weaning female Wistar rats were fed a diet containing a small amount of LNA and no DHA. The animals were daily supplemented 40 days before mating, during pregnancy, and until delivery with 60 mg/kg of LNA or 6 mg/kg of DHA dissolved in coconut oil. Fatty acids were given as ethyl ester derivatives. Controls received coconut oil. The fatty acid composition of blood plasma, erythrocytes, liver, visceral adipose tissue, and brain segments (frontal cortex, hippocampus, and cerebellum) was analyzed. Brain segments obtained from 16- and 19-day-old fetuses and from 2- and 21-day-old rats were also analyzed for fatty acid composition. RESULTS: Supplementation with LNA and DHA induced a similar accretion of DHA in plasma, erythrocytes, liver, and brain segments of the mothers. The adipose tissue showed a higher DHA accretion after DHA-supplementation. The DHA accretion in frontal cortex, hippocampus, and cerebellum obtained from the fetuses and the newborn rats was similar when the mothers were supplemented with LNA and DHA. Our results show that under our experimental conditions a similar accretion of DHA in the different tissues of the mothers and in the brain segments of fetuses and newborn rats is obtained after LNA and DHA supplementation. CONCLUSION: LNA and DHA, at the amounts given in this study, show a similar bioequivalence for DHA accretion in different tissues of the mother and in brain segments of fetuses and newborn rats.
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Animales Recién Nacidos/metabolismo , Encéfalo/embriología , Encéfalo/metabolismo , Ácidos Docosahexaenoicos/administración & dosificación , Ácido alfa-Linolénico/administración & dosificación , Administración Oral , Animales , Química Encefálica , Ácidos Docosahexaenoicos/farmacocinética , Desarrollo Embrionario y Fetal/efectos de los fármacos , Desarrollo Embrionario y Fetal/fisiología , Femenino , Embarazo , Distribución Aleatoria , Ratas , Ácido alfa-Linolénico/farmacocinéticaRESUMEN
Research on Alzheimer's disease (AD) focuses mainly on neuronal death and synaptic impairment induced by â-Amyloid peptide (Aâ), events at least partially mediated by astrocyte and microglia activation. However, substantial white matter damage and its consequences on brain function warrant the study of oligodendrocytes participation in the pathogenesis and progression of AD. Here, we analyze reports on oligodendrocytes' compromise in AD and discuss some experimental data indicative of Aâ toxicity in culture. We observed that 1 ìM of fibrilogenic Aâ peptide damages oligodendrocytes in vitro; while pro-inflammatory molecules (1 ìg/ml LPS + 1 ng/ml IFNã) or the presence of astrocytes reduced the Ab-induced damage. This agrees with our previous results showing an astrocyte-mediated protective effect over Aâ-induced damage on hippocampal cells and modulation of the activation of microglial cells in culture. Oligodendrocytes protection by astrocytes could be, either by reduction of Aâ fibrilogenesis/deposition or prevention of oxidative damage. Likewise, the decrease of Aâ-induced damage by proinflammatory molecules could reflect the production of trophic factors by activated oligodendrocytes and/or a metabolic activation as observed during myelination. Considering the association of inflammation with neurodegenerative diseases, oligodendrocytes impairment in AD patients could potentiate cell damage under pathological conditions.
Asunto(s)
Animales , Enfermedad de Alzheimer/complicaciones , Oligodendroglía , Péptidos beta-Amiloides/toxicidad , Inflamación/inducido químicamenteRESUMEN
La demencia tipo Alzheimer (DTA) es una de las más frecuentes entre los adultos mayores de 65 años de edad. En el sistema nervioso central de los pacientes con enfermedad de Alzheimer se observa tempranamente una marcada alteración del sistema colinérgico, lo que se correlaciona con una disminución de la actividad enzimática de la acetilcolinesterasa (AChE) y un aumento de la butirilcolinesterasa (BuChE). Es probable que alguno de estos cambios bioquímicos pueda tener su reflejo también a nivel periférico, considerando que tanto la AChE como la BuChE se expresan en células no-neuronales, incluyendo a células sanguíneas. En el presente trabajo se evaluaron las actividades de la AchE y de la BuChE en linfocitos y plaquetas tanto en individuos normales como en pacientes con DTA, encontrándose que la actividad de la AChE está disminuida (60 por ciento ) en linfocitos obtenidos de pacientes con DTA, sin observarse cambios aparentes en la actividad de la BuChE. En plaquetas no se observaron diferencias en las actividades de la AChE y de la BuChE entre individuos con DTA y controles. Se evaluó también la captación de 14 C-serotonina por las plaquetas. No se observaron diferencias en la velocidad máxima de captación de 14 C-serotonina; sin embargo, la Km para la captación fue menor para los pacientes con DTA que para los controles. Finalmente el recuento de plaquetas y leucocitos evidenció un aumento en el número total de células en los pacientes con DTA