Instituto de Salud Pública de Chile

FLASH radiotherapy, characterized by ultra-high dose rates (> 40 Gy/s), potentially spares normal tissues while maintaining antitumor efficacy (the FLASH effect). While electron and proton FLASH are explored, pulsed X-ray sources like plasma focus devices offer unique possibilities. Previous work has reported hyper-radiosensitivity in colorectal cancer cells exposed to ultra-high-dose-rate pulsed X-rays from a kilojoule plasma focus (PF) device, without significant effects on non-cancerous cells. This study further investigates the biological effects of ultra-high-dose-rate (~ 10⁷ Gy/min), low-total-dose pulsed X-rays generated by a PF-2 kJ device on colorectal cancer cell lines, focusing on DNA damage, cell cycle progression, and gene expression. Low-total-dose (~ 0.25 Gy), ultra-high-dose-rate pulsed X-rays (0.025 Gy/pulse, a total of 10 pulses, pulses temporally separated by 15–20 s) generated by a PF-2 kJ device induced a significant increase in the SubG1 population in HCT116 and DLD1 cells over 72 h, an effect indicative of apoptosis, which was not observed with conventional X-rays at similar total doses. In addition, pulsed X-rays induced apoptosis in radioresistant MCF-7 breast cancer cells. Whereas conventional X-rays did not cause a significant increase in double-strand breaks (DSBs), surrogate marker γ-H2AX and phosphor-P53(Ser15) signal were detected 30 min following pulsed X-ray exposure and persisted for up to 24 h, and no evidence of G2/M cell cycle arrest was detected in exposed cells. Gene expression analysis and preliminary transcriptomic data further suggest a DNA damage response leading to cell death and global change in general biological processes related to regulation of gene expression. Low-total-dose (~ 0.25 Gy), ultra-high-dose-rate pulsed X-rays generated by a PF-2 kJ device induce significant and sustained DNA damage (DSBs) leading to increased apoptosis in colorectal (HCT-116, DLD-1) and breast (MCF-7) cancer cells, compared to conventional X-rays. These effects, coupled with distinct changes in gene expression, suggest that ultra-high-dose-rate pulsed X-rays may overcomeradio-resistancee without eliciting a conventional DNA damage repair or cell cycle checkpoint response. These findings support the potential of PF-generated pulsed X-rays as a novel sourcof e radiotherapy modality and warrant further investigation, particularly in in vivo models, to assess clinical applicability and safety.

Simulation-based training significantly improved anesthesiology residents' performance in simulated ultrasound-guided pediatric CVC placement. Although not all residents were able to successfully complete the procedure in real patients, the findings suggest a potential transfer of skills acquired through simulation to clinical practice.

IntroductionPeople in prison experience disproportionate health burdens compared with community-based populations, including elevated rates of infectious and non-communicable diseases, mental illness and substance use disorders. Previous studies have consistently shown increased rates of mortality following release from incarceration, particularly from external (unnatural) causes such as suicide and violence. However, evidence on mortality incidence during imprisonment is scarce, and many deaths may be preventable through targeted health and prevention interventions. This study aims to synthesise worldwide evidence on all-cause mortality incidence in prisons.Methods and analysisWe will conduct a worldwide registry study combined with a systematic literature review and meta-regression analysis. Eligible sources will report deaths among incarcerated people between 2005 and 2025 at the national or, where more appropriate, the subnational jurisdictional level. Mortality data will be retrieved from official reports of prison administrations and direct contact with prison authorities. Also, data from international databases and the scientific literature will be reviewed. Incidence rates of all-cause mortality per 100 000 person-years will be calculated and reported for each jurisdiction, alongside standardised mortality ratios comparing imprisoned populations with general population estimates.Ethics and disseminationSince the study relies on anonymised routine data registries available from different sources, an exemption certificate was granted by the Ethics Committee of Diego Portales University (UDP) in Santiago, Chile. Findings will be submitted for publication in a peer-reviewed academic journal.Trial registration numberhttps://osf.io/vkzae.

Abstract. Natural gas is widely used for household cooking, with methane (CH4), its main component, being a potent short-lived greenhouse gas (GHG). While often seen as a cleaner alternative, natural gas combustion and leaks contribute to GHG emissions and indoor air pollution. Yet, fugitive methane emissions from residential appliances, especially cookstoves, are poorly quantified in low- and middle-income countries. In this study, we measured CH4, carbon dioxide (CO2), carbon monoxide (CO), and nitrogen oxides (NOx) emissions from cookstoves in 35 homes in Santiago, Chile, and 23 in Bogotá, Colombia, two countries experiencing rapid growth in natural gas use. We assessed continuous methane leaks, ignition-related emissions, and combustion emissions, using a mass balance approach that accounts for air exchange rates and gas concentrations. Our real-world measurements provide rare data on household cookstove emissions and inform emission factors used in GHG inventories. We found that methane emissions from residential stoves in Bogotá and Santiago are over six times higher than the Tier 1 IPCC emission factors currently used in national inventories. Notably, continuous leaks and ignition-related emissions, which are excluded from official estimates, contribute significantly to total methane emissions. These findings suggest that national inventories in Chile and Colombia underestimate methane emissions from household gas use, highlighting the need for more real-world measurements and research across Latin America. Our results have important implications for improving the accuracy of GHG inventories, understanding the role of household energy use in climate change, and guiding effective mitigation strategies.

To evaluate perceptions of respectful teaching among medical students in Chile and their relationship with sociodemographic, academic, and personal satisfaction factors. A cross-sectional study was conducted across six Chilean universities, involving 443 medical students. We used the Good Teaching Practices Questionnaire (40 items in 9 dimensions) and tools for sociodemographic characterization and academic satisfaction. Data were analyzed using descriptive statistics, reliability coefficients, Spearman correlations, and ANOVA, with significance set at p<0.05. Younger students, those in earlier years, or those recently admitted reported better perceptions of respectful teaching (p<0.05). Men perceived greater support in flexible planning, feedback, and concern for students (p<0.01). Theoretical and synchronous courses were associated with better perceptions of class agility and teaching passion (p<0.001). The highest-rated dimension was subject mastery (Md= 4.00), while concern for students received the lowest score (Md= 3.00). Higher life satisfaction and work-life balance levels are related to respectful teaching. Differences between universities and demographic groups highlight the need for inclusive institutional policies and faculty training to foster equitable and empathetic environments in medical education.

Los ecosistemas xerofíticos naturales de la región de Coquimbo y Atacama presentan un alto nivel de degradación, lo que afecta significativamente los bienes y servicios que estos proporcionan. Es necesario desarrollar estrategias y prácticas de manejo sustentable, sin embargo, falta información y hay limitaciones metodológicas que dificultan la evaluación de los bienes y servicios asociados a tales formaciones. Este estudio busca identificar, describir y cuantificar los bienes y servicios, que proporcionan las formaciones xerofíticas, considerando sus mecanismos de extracción, usos ancestrales, actuales y potenciales, en base al conocimiento tradicional. Esta información permitió reconocer y poner en valor los servicios que proveen las formaciones xerofíticas, evaluando tanto los beneficios como las posibles limitaciones que derivan de su uso. Para lograr estos objetivos, las regiones estudiadas se dividieron en seis macrozonas; en cada una de ellas se realizaron encuestas aplicando una metodología cualitativa enmarcada en un diseño exploratorio y descriptivo, utilizando la teoría fundamentada como método de investigación y análisis. Los resultados indican que, en ambas regiones, las comunidades locales continúan dependiendo del entorno natural y han desarrollado un conocimiento profundo sobre las propiedades de la flora local, además de una comprensión detallada de su entorno, lo que les permite identificar áreas específicas para la recolección de material vegetal, cuyo uso principal es medicinal, alimento animal, alimento humano y leña o carbón.

El objetivo de esta Editorial es ofrecer un resumen sobre los principales hallazgos y desafíos identificados en el Perfil de Seguridad y Salud en el Trabajo de Chile, 2024. Este perfil ha sido desarrollado en colaboración con entidades gubernamentales, universidades y expertos en salud ocupacional a nivel nacional e internacional. Se destaca los principales desafíos presentes en el país, y se proponen prioridades para mejorar las condiciones laborales y salud de la población trabajadora chilena.