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OBJETIVOS: El asma, un problema de salud pública, tiene tasas de mortalidad global variables. En Chile, no existen estudios que informen respecto a la situación nacional. Analizamos la tendencia de mortalidad en adultos chilenos durante un período de 26 años. MÉTODOS: Utilizando datos del Departamento de Estadísticas e Información de Salud y el Instituto Nacional de Estadísticas se calcularon las tasas de mortalidad por asma 1992-2017 en personas ≥ 15 años de edad. Para evitar el impacto de los cambios por edad, las tasas de mortalidad ajustadas se calcularon mediante un método de ajuste directo utilizando la población de 2017 como referencia. Se usó Joinpoint para calcular la pendiente de las tasas ajustadas y para análisis de datos se utilizó Excel STATA versión13. RESULTADOS: Durante el período de 26 años, hubo 5.749 muertes relacionadas con el asma, con un promedio de 221 eventos / año. Las tasas de mortalidad ajustadas por edad disminuyeron significativamente de 3,26 en 1992 a 1,4 por 100.000 habitantes en 2017, con un promedio de disminución anual de -3,3%. La mayor proporción de defunciones se produjo en personas de 65 años o más, representando 79% de los casos en 1992 y 88% de los casos en 2017. CONCLUSIONES: las tendencias de las tasas de mortalidad por asma en Chile, ajustadas por edad, muestran una disminución significativa en los 26 años que abarca este estudio, disminución que es menos acentuada en los últimos 15 años.

OBJETIVES: Asthma, a public health problem, has variable global mortality rates. In Chile, there are no studies to report on the national situation. This study analyzes the mortality trend in Chilean adults over a period of 26 years. METHODS: Using data from the Department of Health Statistics and Information and the National Institute of Statistics, asthma mortality rates 1992-2017 were calculated in people ≥ 15 years-old. To avoid the impact of age changes, adjusted mortality rates were calculated using a direct adjustment method using the 2017 population as a reference. Joinpoint was used to calculate the slope of adjusted rates, and Excel STATA version13 was used for data analysis. RESULTS: Over the 26-year period, there were 5,749 asthma-related deaths, with an average of 221 events per year. Age-adjusted mortality rates decreased significantly from 3.26 in 1992 to 1.4 per 100,000 inhabitants in 2017, with an average annual decline of -3.3%. The highest proportion of deaths occurred in people 65 years of age or older, accounting for 79% of cases in 1992 and 88% of cases in 2017. CONCLUSIONS: In Chile trends in asthma mortality rates age-adjusted show a significant decrease in the 26 years covered by this study, a decrease that is less pronounced in the last 15 years.

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The expansion of agriculture, coupled with the need for sustainable cropping, is one of the greatest challenges of the scientific community working on the generation of new cultivars adapted to abiotic stress conditions. The aim of this study was to evaluate the variability of popcorn lines as to responsiveness and efficiency in phosphorus use, as a first step towards the implementation of a breeding program interested in the practice of sustainable agriculture. Twenty-five popcorn lines were evaluated in two locations with different phosphorus levels in the soil, using a randomized block design. The following traits were measured: plant height, ear height, female flowering date, male flowering date, male-female flowering interval, ear diameter, ear length, 100-grain weight, grain yield, popping expansion, and expanded popcorn volume per hectare. A combined analysis of variance and test of means were performed, and the lines were classified as to their phosphorus use efficiency, according to their production performance in the different environments. The genetic diversity between the lines was estimated by Tocher's and UPGMA clustering methods, using generalized Mahalanobis distance. Lines L59, P7, P2, P3, P4, P8, P10, P9, L66, L70, L69, and P5 were efficient and responsive, whereas lines L75, L80, L61, L77, L63, L65, P1, L54, L53, L88, and L71 were inefficient and nonresponsive. Genetic variability was greater in the environments with low phosphorus in the soil, suggesting that the selection pressure exerted in the stressing environment is a decisive factor to obtain a higher expression of variability.

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OBJECTIVE: To examine the potential association between social capital and self-rated health within a low income community of Santiago, Chile. METHOD: Cross-sectional survey, based on in-home interviews in the municipality of Puente Alto in Santiago, Chile. The participants were 781 residents of four neighbourhoods within Puente Alto (mean age 45.5 years). RESULTS: Principal components analysis with varimax rotation identified five domains of social capital: perceived trust in neighbours, perceived trust in organisations, reciprocity within the neighbourhood, neighbourhood integration, and social participation (Cronbach alphas: 0.58 to 0.77). Trust and reciprocity were significantly associated with better self-rated health. For example, a one standard deviation increase in trust in neighbours was associated with an adjusted odds ratio of 1.10 (95% confidence interval, CI: 1.05 to 1.15) for reporting good self-rated health. By contrast, social participation was associated with a lower odds (0.89, 95% CI: 0.89 to 1.06) of reporting good health. CONCLUSION: Neighbourhood social cohesion, measured by trust and reciprocity, is associated with higher self-rated health. However, social participation did not appear to be associated with better health in this predominantly low income neighbourhood. These findings provide preliminary support to the relevance for social capital as a determinant of health in Chile.

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The objective of this study was the evaluation of the genetic diversity found in HBV circulating among Venezuelan Amerindians and the general population in Colombia. Phylogenetic analysis of the S region in 194 isolates showed that genotype F is highly predominant in Colombia and Venezuela. This might be related to the genetic background of the population. F3 is the main subgenotype which circulates in both countries. Phylogenetic analysis of 61 complete genome sequences of HBV American genotypes confirms the presence of two genotypes F and H, and 4 F subgenotypes. In Venezuela, subgenotypes F1, F2, and F3 circulate in East and West Amerindians, while only F3 was found among South Amerindians. Japreira community derived from Yucpa Amerindians around 150 years ago. However, several Japreira HBV sequences were forming a clade that can be classified as subgenotype 2b, differing from Yucpa sequences that belong mainly to subgenotype F3. The apparent absence of correlation between the phylogenetic groupings of HBV isolates with the ethnical origin in aboriginal populations might be suggesting a recent origin of HBV American subgenotypes, or a genetic drift effect.

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The antibacterial activity of the peptide PsVP-10 obtained from Pseudomonas sp. R10 against Streptococcus mutans and Streptococcus sobrinus was investigated. One hundred and twenty strains of S. mutans and 120 strains of S. sobrinus with and without glycocalyx were isolated from saliva samples in trypticase-yeast-cysteine-sucrose-bacitracin (TYCSB) agar. Bacterial identification was made by polymerase chain reaction. Glycocalyx production was observed in modified TYCSB agar and confirmed with a modified version of the microplate adherence assay. The minimum inhibitory concentration (MIC) of PsVP-10 bacteriocin was determined by means of the agar dilution method, and the time of bacterial death was calculated by means of colony-forming unit counts. The MIC of the bacteriocin PsVP-10 for both bacterial species with and without glycocalyx was < 2 mg/L and the time of bacterial death was less than 240 s for all the studied bacterial strains. Thus, bacteriocin PsVP-10 could be an interesting possibility to combat these cariogenic bacterial species.

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Four species of the genus Rhagoletis are native to Chile: R. nova (Schiner), R. conversa, (Brèthes), R. penela Foote and R. tomatis Foote. Currently, identification of these species is based on morphological criteria, but their strong similarity makes precise recognition difficult. To clarify species separation for quarantine purposes, a reliable method based on a PCR-RFLP procedure is reported. A DNA region containing mitochondrial NADH dehydrogenase genes was selected as a target sequence for the analysis. The amplification products (c. 1 kb) were digested with either SspI or DdeI, yielding specific patterns that differentiated each of the endemic species. Complete nucleotide sequences were determined, confirming empirical restriction maps. This report updates information on the geographical distribution of Rhagoletis species in Chile.

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