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The astrocyte population, around 50% of human brain cells, plays a crucial role in maintaining the overall health and functionality of the central nervous system (CNS). Astrocytes are vital in orchestrating neuronal development by releasing synaptogenic molecules and eliminating excessive synapses. They also modulate neuronal excitability and contribute to CNS homeostasis, promoting neuronal survival by clearance of neurotransmitters, transporting metabolites, and secreting trophic factors. Astrocytes are highly heterogeneous and respond to CNS injuries and diseases through a process known as reactive astrogliosis, which can contribute to both inflammation and its resolution. Recent evidence has revealed remarkable alterations in astrocyte transcriptomes in response to several diseases, identifying at least two distinct phenotypes called A1 or neurotoxic and A2 or neuroprotective astrocytes. However, due to the vast heterogeneity of these cells, it is limited to classify them into only two phenotypes. This review explores the various physiological and pathophysiological roles, potential markers, and pathways that might be activated in different astrocytic phenotypes. Furthermore, we discuss the astrocyte heterogeneity in the main neurodegenerative diseases and identify potential therapeutic strategies. Understanding the underlying mechanisms in the differentiation and imbalance of the astrocytic population will allow the identification of specific biomarkers and timely therapeutic approaches in various neurodegenerative diseases.

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Background: The deployment of OpenAI's ChatGPT-3.5 and its subsequent versions, ChatGPT-4 and ChatGPT-4 With Vision (4V; also known as "GPT-4 Turbo With Vision"), has notably influenced the medical field. Having demonstrated remarkable performance in medical examinations globally, these models show potential for educational applications. However, their effectiveness in non-English contexts, particularly in Chile's medical licensing examinations-a critical step for medical practitioners in Chile-is less explored. This gap highlights the need to evaluate ChatGPT's adaptability to diverse linguistic and cultural contexts. Objective: This study aims to evaluate the performance of ChatGPT versions 3.5, 4, and 4V in the EUNACOM (Examen Único Nacional de Conocimientos de Medicina), a major medical examination in Chile. Methods: Three official practice drills (540 questions) from the University of Chile, mirroring the EUNACOM's structure and difficulty, were used to test ChatGPT versions 3.5, 4, and 4V. The 3 ChatGPT versions were provided 3 attempts for each drill. Responses to questions during each attempt were systematically categorized and analyzed to assess their accuracy rate. Results: All versions of ChatGPT passed the EUNACOM drills. Specifically, versions 4 and 4V outperformed version 3.5, achieving average accuracy rates of 79.32% and 78.83%, respectively, compared to 57.53% for version 3.5 (P<.001). Version 4V, however, did not outperform version 4 (P=.73), despite the additional visual capabilities. We also evaluated ChatGPT's performance in different medical areas of the EUNACOM and found that versions 4 and 4V consistently outperformed version 3.5. Across the different medical areas, version 3.5 displayed the highest accuracy in psychiatry (69.84%), while versions 4 and 4V achieved the highest accuracy in surgery (90.00% and 86.11%, respectively). Versions 3.5 and 4 had the lowest performance in internal medicine (52.74% and 75.62%, respectively), while version 4V had the lowest performance in public health (74.07%). Conclusions: This study reveals ChatGPT's ability to pass the EUNACOM, with distinct proficiencies across versions 3.5, 4, and 4V. Notably, advancements in artificial intelligence (AI) have not significantly led to enhancements in performance on image-based questions. The variations in proficiency across medical fields suggest the need for more nuanced AI training. Additionally, the study underscores the importance of exploring innovative approaches to using AI to augment human cognition and enhance the learning process. Such advancements have the potential to significantly influence medical education, fostering not only knowledge acquisition but also the development of critical thinking and problem-solving skills among health care professionals.

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BACKGROUND: Lesbian, gay, bisexual, transgender, intersex, queer, and other sexual and gender identities (LGBTIQ+) individuals face health inequities. Additionally, medical students report a lack of confidence in providing specific health care to LGBTIQ + individuals, and medical schools do not offer the breadth and depth of coverage needed to fully prepare and make them comfortable in caring for these individuals. This study aims to characterize the teaching of curricular content related to LGBTIQ + health issues in medical schools in Chile. METHODS: This was a cross-sectional descriptive mixed-methods study based on a 15-question survey sent to school directors of the 24 medical schools in Chile, conducted between October 2020 and July 2021. The questions included in the study were mostly based on two pre-existing questionnaires covering content, assessment methods, and identification of barriers to teaching this content. RESULTS: The validated questionnaire was answered by 14 of 24 Chilean medical schools, with 11 schools (78.9%) declaring that they included some training in their curriculum. The predominant range of time allocated to LGBTIQ + training in medical programs was between 1 and 5 h. The most addressed topics were HIV (92.85%), sexual orientation (78.57%), and chronic disease risk in LGBTIQ + populations (78.57%). Most schools, accounting for 71.5%, considered the content they delivered to be "moderately insufficient" or "insufficient". Regarding the teaching methodologies, the most used were lectures (92.8%), clinical cases (42.9%), and clinical simulation (28.6%). CONCLUSION: Most surveyed medical schools reported curricular spaces dedicated to teaching health issues of LGBTIQ + individuals, primarily during the pre-internship training period. However, the time allocated is insufficient, and there is little approach to topics beyond the patient's sexual history or sexual orientation. Given the crucial role of medical schools, they must adopt both local and national strategies to enrich training focused on the care of LGBTIQ + patients.

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The α-synucleinopathies constitute a subset of neurodegenerative disorders, of which Parkinson's disease (PD) is the most common worldwide, characterized by the accumulation of misfolded α-synuclein in the cytoplasm of neurons, which spreads in a prion-like manner to anatomically interconnected brain areas. However, it is not clear how α-synucleinopathy triggers neurodegeneration. We recently developed a rat model through a single intranigral administration of the neurotoxic ß-sitosterol ß-D-glucoside (BSSG), which produces α-synucleinopathy. In this model, we aimed to evaluate the temporal pattern of levels in oxidative and nitrosative stress and mitochondrial complex I (CI) dysfunction and how these biochemical parameters are associated with neurodegeneration in different brain areas with α-synucleinopathy (Substantia nigra pars compacta, the striatum, in the hippocampus and the olfactory bulb, where α-syn aggregation spreads). Interestingly, an increase in oxidative stress and mitochondrial CI dysfunction accompanied neurodegeneration in those brain regions. Furthermore, in silico analysis suggests a high-affinity binding site for BSSG with peroxisome proliferator-activated receptors (PPAR) alpha (PPAR-α) and gamma (PPAR-γ). These findings will contribute to elucidating the pathophysiological mechanisms associated with α-synucleinopathies and lead to the identification of new early biomarkers and therapeutic targets.

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Hodgkin's Lymphoma has a very good prognosis. In the unusually refractory patients allogeneic transplantation offers a chance of cure. The so-called checkpoint inhibitors, such as Nivolumab can play a relevant role in this type of patients. Their side effects and usefulness after allogeneic transplantation are under investigation. Relapse after allogeneic transplantation has an extremely poor prognosis. We report two patients with refractory Hodgkin's lymphoma who relapsed after an allogeneic transplant and who were successfully treated with Nivolumab.

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The current pandemic caused by the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a public health emergency. To date, March 1, 2021, coronavirus disease 2019 (COVID-19) has caused about 114 million accumulated cases and 2.53 million deaths worldwide. Previous pieces of evidence suggest that SARS-CoV-2 may affect the central nervous system (CNS) and cause neurological symptoms in COVID-19 patients. It is also known that angiotensin-converting enzyme-2 (ACE2), the primary receptor for SARS-CoV-2 infection, is expressed in different brain areas and cell types. Thus, it is hypothesized that infection by this virus could generate or exacerbate neuropathological alterations. However, the molecular mechanisms that link COVID-19 disease and nerve damage are unclear. In this review, we describe the routes of SARS-CoV-2 invasion into the central nervous system. We also analyze the neuropathologic mechanisms underlying this viral infection, and their potential relationship with the neurological manifestations described in patients with COVID-19, and the appearance or exacerbation of some neurodegenerative diseases.

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Alzheimer's disease (AD) is the most common neurodegenerative disease worldwide. Histopathologically, AD presents with two hallmarks: neurofibrillary tangles (NFTs), and aggregates of amyloid ß peptide (Aß) both in the brain parenchyma as neuritic plaques, and around blood vessels as cerebral amyloid angiopathy (CAA). According to the vascular hypothesis of AD, vascular risk factors can result in dysregulation of the neurovascular unit (NVU) and hypoxia. Hypoxia may reduce Aß clearance from the brain and increase its production, leading to both parenchymal and vascular accumulation of Aß. An increase in Aß amplifies neuronal dysfunction, NFT formation, and accelerates neurodegeneration, resulting in dementia. In recent decades, therapeutic approaches have attempted to decrease the levels of abnormal Aß or tau levels in the AD brain. However, several of these approaches have either been associated with an inappropriate immune response triggering inflammation, or have failed to improve cognition. Here, we review the pathogenesis and potential therapeutic targets associated with dysfunction of the NVU in AD.

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Hodgkin's Lymphoma has a very good prognosis. In the unusually refractory patients allogeneic transplantation offers a chance of cure. The so-called checkpoint inhibitors, such as Nivolumab can play a relevant role in this type of patients. Their side effects and usefulness after allogeneic transplantation are under investigation. Relapse after allogeneic transplantation has an extremely poor prognosis. We report two patients with refractory Hodgkin's lymphoma who relapsed after an allogeneic transplant and who were successfully treated with Nivolumab.

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Background: ST-segment elevation myocardial infarction (STEMI), is an important cause of morbidity and mortality worldwide, and myocardial reperfusion, when adequate, reduces the complications of this entity. The aim of the study was to describe the clinical and treatment characteristics of STEMI in Peru and the relationship of successful reperfusion with in-hospital adverse events. Materials and methods: Prospective, multicenter cohort of STEMI patients attended during 2020 in public hospitals in Peru. We evaluated the clinical, therapeutic characteristics and in-hospital adverse events, also the relationship between successful reperfusion and adverse events. Results: A total of 374 patients were included, 69.5% in Lima and Callao. Fibrinolysis was used in 37% of cases (pharmacoinvasive 26% and fibrinolysis alone 11%), primary angioplasty with < 12 hours of evolution in 20%, late angioplasty in 9% and 34% did not access adequate reperfusion therapies, mainly due to late presentation. Ischemia time was longer in patients with primary angioplasty compared to fibrinolysis (median 7.7 hours (RIQ 5-10) and 4 hours (RIQ 2.3-5.5) respectively). Mortality was 8.5%, the incidence of post-infarction heart failure was 27.8% and of cardiogenic shock 11.5%. Successful reperfusion was associated with lower cardiovascular mortality (RR:0.28; 95%CI: 0.12-0.66, p=0.003) and lower incidence of heart failure during hospitalization (RR: 0.61; 95%CI: 0.43-0.85, p=0.004). Conclusions: Fibrinolysis continues to be the most frequent reperfusion therapy in public hospitals in Peru. Shorter ischemia-to-reperfusion time was associated with reperfusion success, and in turn with fewer in-hospital adverse events.

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The perception of music depends on the normal function of the peripheral and central auditory system. Aged subjects without hearing loss have altered music perception, including pitch and temporal features. Presbycusis or age-related hearing loss is a frequent condition in elderly people, produced by neurodegenerative processes that affect the cochlear receptor cells and brain circuits involved in auditory perception. Clinically, presbycusis patients have bilateral high-frequency hearing loss and deteriorated speech intelligibility. Music impairments in presbycusis subjects can be attributed to the normal aging processes and to presbycusis neuropathological changes. However, whether presbycusis further impairs music perception remains controversial. Here, we developed a computerized version of the Montreal battery of evaluation of amusia (MBEA) and assessed music perception in 175 Chilean adults aged between 18 and 90 years without hearing complaints and in symptomatic presbycusis patients. We give normative data for MBEA performance in a Latin-American population, showing age and educational effects. In addition, we found that symptomatic presbycusis was the most relevant factor determining global MBEA accuracy in aged subjects. Moreover, we show that melodic impairments in presbycusis individuals were diminished by music training, while the performance in temporal tasks were affected by the educational level and music training. We conclude that music training and education are important factors as they can slow the deterioration of music perception produced by age-related hearing loss.

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The direct link between lipid metabolism alterations and the increase of cardiovascular risk are well documented. Dyslipidemias, including isolated high LDL-c or mixed dyslipidemia, such as those seen in diabetes (hypertriglyceridemia, high LDL-c or low HDL-c), correlate with a significant risk of cardiovascular and cerebrovascular disease worldwide.  This review analyzes the current knowledge concerning the genetic basis of lipid metabolism alterations, emphasizing lipoprotein lipase gene mutations and the HindIII polymorphism, which are associated with decreased levels of triglycerides and LDL-c, as well as higher levels of HDL-c. These patterns would be associated with decreased global morbidity and mortality, providing protection against cardiovascular and cerebrovascular diseases.

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Se presentan los resultados más relevantes de la traducción, adaptación y validación del CIDI-SAM, instrumento diagnóstico del abuso y dependencia de sustancias psicoactivas. Sus índices de validación lo convierten en una herramienta de primera elección para estudios sobre drogas, especialmente a nivel comunitario

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Se analizó los resultados obtenidos en el tratamiento de 18 pacientes con traumatismo hepático (1989-1993). La mayoría de sexo masculino, edad x 31 años. El 69 por ciento fue debido a la contusión y el 31.25 por ciento tenia lesiones asociadas. Diez eran menores (grado I o II) y los 6 restantes eran traumatismos hepáticos complejos. (Grado III o Iv). No se trato ninguna en forma conservadora, la indicación quirúrgica inicial fué clinínica en 8 pacientes, punción abdominal 6, lavado peritoneal 1 y por ecografía 1. El 81.25 por ciento pudo ser tratado con medidas simples (hepatorrafia simple o con drenaje). En las restantes se utilizó digitoclasia mas parche de epiplon (6.25 por ciento), Digitoclasia mas taponamiento con gasa (6.25 por ciento) y ligadura del lóbulo derecho mas drenaje (6.25 por ciento). Dos pacientes presenataron complicaciones, derrame pleural derecho (1) y absceso de pared. No hubierón reintervenciones ni fallecidos en nuetra serie.

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Se evaluó el incremento como respuesta al aporte de energía y nutrientes que proporciona la dieta del niño de pretérmino hospitalizado, durante los dos primeros meses de vida. La muestra fue de 21 niños de pretérmino 11 del Hospital Nacional de Niños y 10 del Hospital Dr. Rafael Angel Calderón Guardia. La respuesta de los niños al tratamiento nutricional se valoró mediante los indicadores peso, talla y perímetro cefálico. Otros factores que pudieran afectar su recuperación nutricional, se estimaron con un registro diario de la morbilidad, número y características de las deposiciones, número de vómitos y temperatura. Se encontró una alta variabilidad en la composición de las fórmulas lácteas, evidenciada por altas desviaciones estándar en los promedios de composición de calorías y grasa. Los niños del Hospital Nacional de Niños consumieron 150 kcals y 2,8 g de proteína, 4,6 g de grasa y 15,5g de carbohidratos por kilo de peso, por día, mientra que la ingesta de los niños del Hospital Calderón Guardia fue de 126 kcals , 2,5 g de proteína, 4,1 g de grasa y 17,9 g de carbohidratos por kilo de peso, por día. La diferencia es significativa entre el consumo de energía y carbohidratos en ambos hospitales (p<0,05). Las velocidades de crecimiento en peso, talla y perímetro cefálico, en este orden fueron de 22,22 g por día; 1,12 cm por semana y 1,00 cm por semana en el Hospital Nacional de Niños y de 13,36 g por día, 0,81 cm por semana y 0,61 cm por semana en el Hospital Calderón Guardia. En los casos del Hospital Nacional de Niños los valores fueron significativamente mayores que los del Hospital Calderón Guardia (P<0,05) Los resultados sugieren que la alta variabilidad en la composición, calidad de los nutrientes y métodos de preparación empleados en la elaboración de las fórmulas lácteas impiden a los niños de pretérmino lograr velocidades de crecimiento óptimas.

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Este texto es un instrumento básico para conocer y poner en el corazón y en las obras el Mensaje de Jesús. El libro está destinado a los responsables de llevar adelante la formación de las comunidades del campo, de la ciudad y a quines deseen compartir la Palabra en comunidad.