Efectos negativos en la investigación y el quehacer médico en Chile de la Ley 20.584 y la Ley de Neuroderechos en discusión: la urgente necesidad de aprender de nuestros errores / Negative effects of the patients' rights law and neuro-rights bill in Chile

Recently, the Chilean Senate approved the main ideas of a constitutional reform and a Neuro-rights bill. This bill aims to protect people from the potential abusive use of "neuro-technologies". Unfortunately, a literal interpretation of this law can produce severe negative effects both in the development of neuroscience research and medical practice in Chile, interfering with current treatments in countless patients suffering from neuropsychiatric diseases. This fear stems from the observation of the negative effects that recent Chilean legislations have produced, which share with the Neuro-Rights Law the attempt to protect vulnerable populations from potential abuse from certain medical interventions. In fact, Law 20,584 promulgated in 2012, instead of protecting the most vulnerable patients "incapacitated to consent", produced enormous, and even possibly irreversible, damage to research in Chile in pathologies that require urgent attention, such as many neuropsychiatric diseases. This article details the effects that Law 20.584 had on research in Chile, how it relates to the Neuro-Rights Law, and the potential negative effects that the latter could have on research and medical practice, if it is not formulated correcting its errors.

Orientaciones éticas para la toma de decisiones médicas en el contexto de la pandemia de COVID-19 en Chile / Ethical guidelines for medical decision-making during COVID-19 pandemic in Chile

The catastrophic emergency experienced by many countries with the COVID-19 pandemic emphasized the importance of bioethics for decision-making, both at the public health (equitable and effective policies) and at the clinical level. At the clinical level, the issues are the fulfillment of medical care demand with adequate health care teams, infrastructure, and supplies, and to cover critical care demands that surpass the available resources. Therefore, ethically correct approaches are required for the allocation of life sustaining resources. There are recommendations for the allocating life support during disasters based on multiple considerations, including ethical ones. However, the ethical criteria of existing guidelines are variable. Ethical principles usually considered are saving the greatest number of lives, saving the greatest number of years of life and the principle of the life cycle or the goal to give each individual equal opportunity to live through the various phases of life. However, the centrality of the human being and the search for the common good should be considered. Knowledge of public perspectives and moral benchmarks on these issues is essential. A successful assignment effort will require everyone's trust and cooperation. Decision making should be planned and discussed in advance, since in-depth deliberation will be extremely complex during the disaster. Our goal is to help the health care teams to wisely allocate resources in shortage periods.

Trasplante de células troncales: mecanismos de acción para sus usos potenciales en neurología / Stem cells transplant: potentially useful mechanism for neurology

Stem cells have a great potential for the treatment of presently incurable neurological diseases, including spinal trauma, cerebrovascular pathology, brain tumor and neurodegenerative processes, such as Parkinson and Alzheimer's disease, Huntington, multiple sclerosis and amyotrophic lateral sclerosis. Aims: To discuss the characteristics of the various stem cells types having been proposed for cell therapy, and the biological mechanisms responsible for their therapeutic effects. Report: Stem cells can be induced to differentiate into specialized cells such as neurons and glial cells, and they can influence the environment around them, both through the secretion of neurotrophic factors and immunomodulation of the host neuroimmune response. Furthermore, the understanding of the modulatory effect of stem cells could lead to the development of new therapeutic paradigms. Nevertheless, two important limitations of the field are that the ideal source for stem cells is not well defined yet and the mechanism of stem cell mediated functional improvement is not well understood. Conclusions: Research is currently focused on the biological mechanisms of stem cells therapy and the assessment of stem cell programming and delivery to the target regions. Furthermore, future research will increasingly target ways to enhance effectiveness of the stem cell therapy, including its combination with gene therapy. Regardless its enormous potentials, there are still many problems to be solved before clinical application of stem cell therapy can de used in neurological disease patients.

Introducción: Las células troncales tienen un gran potencial para el tratamiento de enfermedades neurológicas actualmente incurables, incluyendo el trauma espinal, patología cerebrovascular y procesos neurodegenerativos como el Parkinson, Alzheimer, Huntington, esclerosis múltiple o la esclerosis lateral amiotrófica. Objetivo: Discutir las características de diversas células troncales que han sido propuestas para terapia celular, y los mecanismos biológicos responsables de sus efectos terapéuticos. Desarrollo: Las células troncales pueden ser inducidas a diferenciarse en células especializadas como neuronas y células gliales, y pueden influenciar su entorno, tanto a través de la secreción de factores neurotróficos como por la inmunomodulación de la respuesta neuroinmune. La comprensión del efecto modulador de las células troncales podría orientar el desarrollo de nuevos paradigmas terapéuticos. Sin embargo, dos limitaciones importantes que persisten son, que la célula troncal ideal aún no está bien definida, y que los mecanismos que median la mejoría inducida por ellas no se comprende bien. Conclusiones: La investigación se enfoca actualmente en los mecanismos biológicos de la actividad terapéutica de las células troncales, en la evaluación de la programación celular y en su acceso a las regiones blanco. La investigación futura se dirigirá progresivamente a encontrar formas de aumentar la efectividad de las células troncales, incluyendo su combinación con terapia genética. Sin embargo, aún existen numerosos problemas que resolver antes que la terapia con células troncales pueda ser usada en pacientes con enfermedades neurológicas.

El síndrome metabólico: De factor agravante a principal factor de riesgo patogénico en diversas enfermedades crónicas / The metabolic syndrome: From an aggravating condition to a pathogenic risk factor for chronic diseases

In recent years, a rapidly increasing number of studies have focused on the association between metabolic syndrome and several chronic diseases. However, it is difficult to determine a well defined pathogenic relationship, due to the etiological heterogeneity and comorbidities of these diseases. Research efforts are aiming to identify the convergent biological mechanisms that mediate the effects of hyperinsulinemia, hyperglycemia, dyslipidemia, and hypertension. All these conditions define the metabolic syndrome, that increases the risk for several diseases. The knowledge of these biological mechanisms associated with this syndrome will elucidate the pathogenic association between a variety of chronic diseases, including its pathogenic link with cardiovascular diseases and the most common forms of dementia. The development of new therapeutic and preventive strategies for these diseases will be a corollary of this research.

Oligodendrocytes damage in Alzheimer's disease: Beta amyloid toxicity and inflammation

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.

La Barrera Hemato-Encefálica en la patología del Sistema Nervioso Central: su importancia en la Respuesta Inflamatoria / The Blood-Brain Barrier and the Pathology of the Central Nervous System: Its importance for the Inflammatory Response

Introducción. La Barrera Hemato-Encefálica (BHE) constituye una estructura histológica bien definida que participa tanto en la homeostasis normal del Sistema Nervioso Central (SNC) como en varios procesos patológicos que lo afectan. Métodos. Se evaluaron más de 50 revisiones y trabajos originales publicados en los últimos años en los que se discuten aspectos del desarrollo, morfología y función normales de la BHE, y alteraciones de su función y su participación en el desarrollo de patologías del SNC. La revisión aborda los mecanismos que pueden determinar la disfunción de la BHE y sus efectos sobre la patología del SNC. Resultados. La función de la BHE como barrera física y metabólica es la de separar al SNC de la periferia. Sin embargo, la BHE, lejos de comportarse como una estructura pasiva, juega un papel activo en la mantención de la función normal del SNC. Dependiendo de la presencia de daño o ciertas señales sistémicas, la integridad de la BHE puede ser comprometida, aumentando su permeabilidad. Conclusiones. Las características morfo-funcionales de la BHE son determinantes en la manifestación de ciertas patologías del SNC, o limitan las aproximaciones terapéuticas para abordarlas. La posibilidad de influir sobre la permeabilidad de la BHE de manera controlada y en forma espacial y temporalmente restringida potencialmente puede modificar tanto la prevención como el tratamiento de muchas enfermedades del SNC.