51 research outputs found

    Functional Amyloids Composed of Phenol Soluble Modulins Stabilize Staphylococcus aureus Biofilms

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    Staphylococcus aureus is an opportunistic pathogen that colonizes the skin and mucosal surfaces of mammals. Persistent staphylococcal infections often involve surface-associated communities called biofilms. Here we report the discovery of a novel extracellular fibril structure that promotes S. aureus biofilm integrity. Biochemical and genetic analysis has revealed that these fibers have amyloid-like properties and consist of small peptides called phenol soluble modulins (PSMs). Mutants unable to produce PSMs were susceptible to biofilm disassembly by matrix degrading enzymes and mechanical stress. Previous work has associated PSMs with biofilm disassembly, and we present data showing that soluble PSM peptides disperse biofilms while polymerized peptides do not. This work suggests the PSMs' aggregation into amyloid fibers modulates their biological activity and role in biofilms

    Assessment of City Level Human Health Impact and Corresponding Monetary Cost Burden due to Air Pollution in India Taking Agra as a Model City

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    Objectives of the present study are to provide quantitative estimations of air pollution health impacts and monetary burden on people living in Agra city, the fourth most populated city in Uttar Pradesh, India. To estimate the direct health impacts of air pollution in Agra city during year 2002 to 2014, 'Risk of Mortality/Morbidity due to Air Pollution' model was used which is adopted from air quality health impact assessment software, developed by world health organization (WHO). Concentrations of NO2, SO2 and PM10 have been used to assess human health impacts in terms of attributable proportion of the health outcome as- annual number of excess cases of total mortality, cardiovascular mortality, respiratory mortality, hospital admission chronic obstructive pulmonary disease (COPD), hospital admission respiratory disease and hospital admission cardiovascular disease and it was observed that attributable number of cases were 1325, 908, 155, 138, 1230 and 348 respectively in year 2002. However, after thirteen years these figures increased to 1607, 1095, 189, 167, 1568 and 394 respectively. From these results, it was observed that from 2002 to 2014, the attributable number of cases increased almost by 13.43 to 27.52%. As a result, the monetary cost burden due to air pollution related health effects also increased very highly; it was 67.99 million USin2002,whichtransformedinto254.52millionUS in 2002, which transformed into 254.52 million US in 2014. In future, if air quality continues to follow current pollutant concentration trend, the monetary cost burden will reach a level of US$ 570.12 million in year 2020, which is not only a thoughtful matter but also a threatful matter and it signifies the importance of rectification measures for air quality in Agra city

    Burden of disease attributed to ambient PM2.5 and PM10 exposure in 190 cities in China

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    Particulate air pollution is becoming a serious public health concern in urban cities of China. Association of disability-adjusted life years (DALYs) and economic loss with air pollution-related health effects demand quantitative analysis for correctional measures in air quality. This study applies an epidemiology-based exposure-response function to obtain the quantitative estimate of health impact of particulate matter PM2.5 and PM10 across 190 cities of China during years 2014-2015. The annual average concentration of PM2.5 and PM10 is 57 +/- 18 mu g/m(3) (ranging from 18 to 119 mu g/m(3)) and 97.7 +/- 34.2 mu g/m(3) (ranging from 33.5 to 252.8 mu g/m(3)), respectively. Based on the present study, the total estimated annual premature mortality due to PM2.5 is 722,370 [95% confidence interval (CI) = 322,716-987,519], 79% of which accounts for adult cerebrovascular disease (stroke) and ischemic heart disease (IHD). The premature mortality in megacities is very high, such as Chongqing (25,162/year), Beijing (19,702/year), Shanghai (19,617/year), Tianjin (13,726/year), and Chengdu (12,356/year). PM10 pollution has caused 1,491,774 (95% CI = 972,770-1,960,303) premature deaths (age > 30) in China. Further, 3,614,064 cases of chronic bronchitis (CB); 13,759,894 cases of asthma attack among all ages; 191,709 COPD-related hospital admission (HA) cases; 499,048 respiratory-related HA; 357,816 cerebrovascular HA; and 308,129 cardiovascular-related HA due to PM10 pollution have been estimated during 2014-2015. Chongqing, Beijing, Baoding, Tianjin, and Shijiazhuang are the top five contributors to pollution-related mortality, accounting for 3.10, 2.71, 2.49, 2.20, and 2.02%, respectively, of the total deaths caused by PM10 pollution. The total DALYs associated with PM2.5 and PM10 pollution in China is 7.2 and 20.66 million in 2014-2015, and mortality and chronic bronchitis shared about 93.3% of the total DALYs for PM10. During this period, the economic cost of health impact due to PM10 is approximately US$304,122 million, which accounts for about 2.94% of China's gross domestic product (GDP). Megacities are expected to contribute relatively more to the total costs. The present methodology could be used as a tool to help policy makers and pollution control board authorities, to further analyze costs and benefits of air pollution management programs in China

    Human health risk as a basis for prioritizing air quality monitoring stations in a megacity: a case study

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    This paper presents an objective methodology for determining the optimum number of ambient air quality stations in a monitoring network based on human health risk (HHR). The case study is related to HHRs in terms of mortality and morbidity (hospital admission) due to adverse effects of air pollution in 41 wards in Delhi in India, which were evaluated using Ri-MAP model developed by the World Health Organization (WHO). By adopting the World Health Organization (WHO) guideline concentrations of the air pollutants total suspended particles (TSP) or its surrogate, sulfur dioxide (SO2) and nitrogen dioxide (NO2), concentration-response relationships and a population attributable-risk proportion concept are applied. It was found that an average total mortality was 1150 [631-1852 at 95% confidence interval (CI)], cardiovascular mortality was 450 (440-665 at 95% CI), respiratory mortality was 170 (96-288 at 95% CI), and chronic obstructive pulmonary disease (COPD) morbidity was 176 (2-333 at 95% CI) for every one million population in Delhi according to 2008 population statistics. There were 20 wards which had mortality and morbidity higher than the average. It may be concluded that pollution control authorities need to monitor air quality in these 20 identified locations having high health risk more rigorously. From the result, it was also seen that the excess number of mortality and morbidity in Delhi was basically due to particulate matter (PM) than due to gaseous pollutants. Hence, the pollution control authorities in Delhi urgently need proper management policy to improve ambient air quality in terms of TSP levels

    Disability-adjusted life years and economic cost assessment of the health effects related to PM2.5 and PM10 pollution in Mumbai and Delhi, in India from 1991 to 2015

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    Particulate air pollution is becoming a serious public health concern in urban cities in India due to air pollutionrelated health effects associated with disability-adjusted life years (DALYs) and economic loss. To obtain the quantitative result of health impact of particulate matter (PM) in most populated Mumbai City and most polluted Delhi City in India, an epidemiology-based exposure-response function has been used to calculate the attributable number of mortality and morbidity cases from 1991 to 2015 in a 5-year interval and the subsequent DALYs, and economic cost is estimated of the health damage based on unit values of the health outcomes. Here, we report the attributable number of mortality due to PM10 in Mumbai and Delhi increased to 32,014 and 48,651 in 2015 compared with 19,291 and 19,716 in year 1995. And annual average mortality due to PM2.5 in Mumbai and Delhi was 10,880 and 10,900. Premature cerebrovascular disease (CEV), ischemic heart disease (IHD), and chronic obstructive pulmonary disease (COPD) causes are about 35.3, 33.3, and 22.9% of PM2.5-attributable mortalities. Total DALYs due to PM10 increased from 0.34 million to 0.51 million in Mumbai and 0.34 million to 0.75 million in Delhi from average year 1995 to 2015. Among all health outcomes, mortality and chronic bronchitis shared about 95% of the total DALYs. Due to PM10, the estimated total economic cost at constant price year 2005 US$ increased from 2680.87 million to 4269.60 million for Mumbai City and 2714.10 million to 6394.74 million for Delhi City, from 1995 to 2015, and the total amount accounting about 1.01% of India's gross domestic product (GDP). A crucial presumption is that in 2030, PM10 levels would have to decline by 44% (Mumbai) and 67% (Delhi) absolutely to maintain the same health outcomes in year 2015 levels. The results will help policy makers from pollution control board for further costbenefit analyses of air pollution management programs in Mumbai and Delhi

    Estimating premature mortality attributable to PM2.5 exposure and benefit of air pollution control policies in China for 2020

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    In past decade of rapid industrial development and urbanization, China has witnessed increasingly persistent severe haze and smog episodes, posing serious health hazards to the Chinese population, especially in densely populated cities. Quantification of health impacts attributable to PM2.5 (particulates with aerodynamic diameter <= 2.5 mu m) has important policy implications to tackle air pollution. The Chinese national monitoring network has recently included direct measurements of ground level PM2.5, providing a potentially more reliable source for exposure assessment. This study reports PM2.5-related long-term mortality of year 2015 in 161 cities of nine regions across China using integrated exposure risk (IER) model for PM2.5 exposure-response functions (ERF). It further provides an estimate of the potential health benefits by year 2020 with a realization of the goals of Air Pollution Prevention and Control Action Plan (APPCAP) and the three interim targets (ITs) and Air Quality Guidelines (AQG) for PM2.5 by the World Health Organization (WHO). PM2.5-related premature mortality in 161 cities was 652 thousand, about 6.92% of total deaths in China during year 2015. Among all premature deaths, contributions of cerebrovascular disease (stroke), ischemic heart disease (IHD), chronic obstructive pulmonary disease (COPD), lung cancer (LC) and acute lower respiratory infections (ALRIs) were 51.70, 26.26, 11.77, 9.45 and 0.82%, respectively. The premature mortality in densely populated cities is very high, such as Tianjin (12,533/year), Beijing (18,817/year), Baoding (10,932/year), Shanghai (18,679/year), Chongqing (23,561/year), Chengdu (11,809/year), Harbin (9037/year) and Linyi (9141/year). The potential health benefits will be 4.4, 16.2, 34.5, 63.6 and 81.5% of the total present premature mortality when PM2.5 concentrations in China meet the APPCAP, WHO IT-1, IT-2, IT-3 and AQG respectively, by the year 2020. In the current situation, by the end of year 2030, even if Chines government fulfills its own target to meet national ambient air quality standard of PM2.5 (35 mu g/m(3)), total premature mortality attributable to PM2.5 will be 574 thousand across 161 cities. The present methodology will greatly help policy makers and pollution control authorities to further analyze cost and benefits of air pollution management programs in China. (C) 2017 Elsevier B.V. All rights reserved
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