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Exposure to heavy metals may cause the overproduction of reactive oxygen species, generating oxidative stress and consequently, various harms to human health. The soil surrounding the Ventanas Industrial Complex, in Puchuncaví and Quintero municipal districts on the central Chilean coast, contains heavy metal concentrations (As, Cu, Pb, Zn, among others) that far exceed the maximum permissible levels established by Italian soil standards (used as a reference). This study aimed to investigate the potential association between heavy metal exposure in humans and the levels of oxidative stress biomarkers in inhabitants of these locations. We took blood samples from 140 adults living in sites with high concentrations of heavy metals in the soil and compared them with blood samples from 140 adults living in areas with normal heavy metal concentrations. We assessed lipid peroxidation, damage to genetic material, and Total Antioxidant Capacity in these blood samples. Our results indicate an association between oxidative damage and heavy metal exposure, where the inhabitants living in exposed areas have a higher level of DNA damage compared with those living in control areas. Given that DNA damage is one of the main factors in carcinogenesis, these results are of interest, both for public health and for public policies aimed at limiting human exposure to environmental pollution. [ABSTRACT FROM AUTHOR]

In Chile, 18% of the population is over 60 years old and is projected to reach 31% in three decades. An aging population demands the development of strategies to improve quality of life (QoL). In this randomized trial, we present the implementation and evaluation of the Quida platform, which consists of a network of unintrusive sensors installed in the houses of elderly participants to monitor their activities and provide assistance. Sixty-nine elderly participants were included. A significant increase in overall QoL was observed amongst participants allocated to the interventional arm (p < 0.02). While some studies point out difficulties monitoring users at home, Quida demonstrates that it is possible to detect presence and movement to identify patterns of behavior in the sample studied, allowing us to visualize the behavior of older adults at different time intervals to support their medical evaluation. [ABSTRACT FROM AUTHOR]

Simple Summary: COVID-19 is frequently suspected based on clinical features, such as fever, cough, headache, or loss of taste. However, it remains unclear whether these manifestations are reliable indicators of disease. We sought to evaluate the diagnostic accuracy of clinical manifestations in identifying patients with COVID-19. Data from a nationwide database comprising of 2,187,962 patients who sought medical care in Chile were analysed. Information regarding age, gender, type of insurance, a history of a close contact with COVID-19, and several clinical features was obtained. The most common complaints were headache, muscle aches, and cough. No single clinical feature was precise enough to fully confirm or exclude COVID-19. The combination of several of these manifestations with epidemiological risk factors into a model showed a reasonable accuracy in detecting cases of COVID-19. (1) Background: The diagnosis of COVID-19 is frequently made on the basis of a suggestive clinical history and the detection of SARS-CoV-2 RNA in respiratory secretions. However, the diagnostic accuracy of clinical features is unknown. (2) Objective: To assess the diagnostic accuracy of patient-reported clinical manifestations to identify cases of COVID-19. (3) Methodology: Cross-sectional study using data from a national registry in Chile. Infection by SARS-CoV-2 was confirmed using RT-PCR in all cases. Anonymised information regarding demographic characteristics and clinical features were assessed using sensitivity, specificity, and diagnostic odds ratios. A multivariable logistic regression model was constructed to combine epidemiological risk factors and clinical features. (4) Results: A total of 2,187,962 observations were available for analyses. Male participants had a mean age of 43.1 ± 17.5 years. The most common complaints within the study were headache (39%), myalgia (32.7%), cough (31.6%), and sore throat (25.7%). The most sensitive features of disease were headache, myalgia, and cough, and the most specific were anosmia and dysgeusia/ageusia. A multivariable model showed a fair diagnostic accuracy, with a ROC AUC of 0.744 (95% CI 0.743–0.746). (5) Discussion: No single clinical feature was able to fully confirm or exclude an infection by SARS-CoV-2. The combination of several demographic and clinical factors had a fair diagnostic accuracy in identifying patients with the disease. This model can help clinicians tailor the probability of COVID-19 and select diagnostic tests appropriate to their setting. [ABSTRACT FROM AUTHOR]

Gene expression can be modified in people who are chronically exposed to high concentrations of heavy metals. The soil surrounding the Ventanas Industrial Complex, located on the coastal zone of Puchuncaví and Quintero townships (Chile), contain heavy metal concentrations (As, Cu, Pb, Zn, among others) that far exceed international standards. The aim of this study was to determine the potential association of the heavy metals in soils, especially arsenic, with the status of methylation of four tumor suppressor genes in permanent residents in those townships. To study the methylation status in genes p53, p16, APC, and RASSF1A, we took blood samples from adults living in areas near the industrial complex for at least 5 years and compared it to blood samples from adults living in areas with normal heavy metal concentrations of soils. Results indicated that inhabitants of an area with high levels of heavy metals in soil have a significantly higher proportion of methylation in the promoter region of the p53 tumor suppressor gene compared with control areas (p-value: 0.0035). This is the first study to consider associations between heavy metal exposure in humans and aberrant DNA methylation in Chile. Our results suggest more research to support consistent decision-making on processes of environmental remediation or prevention of exposure. [ABSTRACT FROM AUTHOR]

Teacher evaluation and development policies around the world are undergoing significant reform. Classroom observation often carries a considerable weight in teacher appraisal and improvement systems, and provides the critical formative anchor informing professional development. This study examined a purposively selected sample of sixteen classroom observation systems in six countries, including high performing Singapore and Japan, regional exemplar Chile, the three largest school districts in the United States, and other interesting examples in Australia, Germany and the United States to add diversity to the sample. The study offers an analytic framework for understanding classroom observation systems across contexts, distinguishing conceptual, methodological and policy aspects that shape these systems. The sixteen systems were remarkably consistent in their stated overall purposes, but there was variation in terms of how they operationalized good teaching, the degree of standardization of the observation process, emphasis on validation, and information uses. The paper describes and discusses these characteristics in order to help researchers and policymakers reflect on the available options and take more informed decisions in designing classroom observation for evaluating and improving teaching. [ABSTRACT FROM AUTHOR]

Background: delirium is a clinical syndrome associated with multiple short and long-term complications and therefore prevention is an essential part of its management. This study was designed to assess the efficacy of multicomponent intervention in delirium prevention.Methods: a total of 287 hospitalised patients at intermediate or high risk of developing delirium were randomised to receive a non-pharmacological intervention delivered by family members (144 patients) or standard management (143 patients). The primary efficacy outcome was the occurrence of delirium at any time during the course of hospitalisation. Three validated observers performed the event adjudication by using the confusion assessment method screening instrument.Results: there were no significant differences in the baseline characteristics between the two groups. The primary outcome occurred in 5.6% of the patients in the intervention group and in 13.3% of the patients in the control group (relative risk: 0.41; confidence interval: 0.19–0.92; P = 0.027).Conclusion: the results of this study show that there is a benefit in the non-pharmacological prevention of delirium using family members, when compared with standard management of patients at risk of developing this condition. [ABSTRACT FROM PUBLISHER]

In Chile, 18% of the population is over 60 years old and is projected to reach 31% in three decades. An aging population demands the development of strategies to improve quality of life (QoL). In this randomized trial, we present the implementation and evaluation of the Quida platform, which consists of a network of unintrusive sensors installed in the houses of elderly participants to monitor their activities and provide assistance. Sixty-nine elderly participants were included. A significant increase in overall QoL was observed amongst participants allocated to the interventional arm (p < 0.02). While some studies point out difficulties monitoring users at home, Quida demonstrates that it is possible to detect presence and movement to identify patterns of behavior in the sample studied, allowing us to visualize the behavior of older adults at different time intervals to support their medical evaluation.

Detection of positive selection signatures in populations around the world is helping to uncover recent human evolutionary history as well as the genetic basis of diseases. Most human evolutionary genomic studies have been performed in European, African, and Asian populations. However, populations with Native American ancestry have been largely underrepresented. Here, we used a genome-wide local ancestry enrichment approach complemented with neutral simulations to identify postadmixture adaptations underwent by admixed Chileans through gene flow from Europeans into local Native Americans. The top significant hits (P = 2.4×10-7) are variants in a region on chromosome 12 comprising multiple regulatory elements. This region includes rs12821256, which regulates the expression of KITLG, a well-known gene involved in lighter hair and skin pigmentation in Europeans as well as in thermogenesis. Another variant from that region is associated with the long noncoding RNA RP11-13A1.1, which has been specifically involved in the innate immune response against infectious pathogens. Our results suggest that these genes were relevant for adaptation in Chileans following the Columbian exchange., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.)

Identifying the ancestral components of genomes of admixed individuals helps uncovering the genetic basis of diseases and understanding the demographic history of populations. We estimate local ancestry on 313 Chileans and assess the contribution from three continental populations. The distribution of ancestry block-length suggests an average admixing time around 10 generations ago. Sex-chromosome analyses confirm imbalanced contribution of European men and Native-American women. Previously known genes under selection contain SNPs showing large difference in allele frequencies. Furthermore, we show that assessing ancestry is harder at SNPs with higher recombination rates and easier at SNPs with large difference in allele frequencies at the ancestral populations. Two observations, that African ancestry proportions systematically decrease from North to South, and that European ancestry proportions are highest in central regions, show that the genetic structure of Chileans is under the influence of a diffusion process leading to an ancestry gradient related to geography.