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Abstract Objectives Asthma can be triggered by various factors due to different etiologies. Environmental factors remain a common trigger of asthma, especially amongst children, and such ambient exposures can be harder to avoid compared to behavioral triggers. As such, the contribution of environmental factors may be enhanced when considering repeat asthma cases compared to initial presentations. To test this hypothesis, we assessed associations between ambient temperature and hospital admissions for asthma in Hong Kong and stratified admission records into first and repeat asthma hospitalizations. Methods The daily number of asthma hospitalizations among children aged 0–5 years in Hong Kong during 2007–2011 was regressed on daily mean temperature using distributed lagged nonlinear models, with adjustment for seasonal patterns, day-of-week effects, and other meteorological factors and air-pollutants. Analyses were stratified by summer/winter and by type of admission (first admission and repeated admission). Results About 33% of the 12284 asthma hospitalizations were repeat admissions. Repeat admissions demonstrated higher sensitivity to high temperature in the summer. During this period, high temperatures were associated with increased risk of repeat admission but not with first admissions: RR (95% CI) comparing 31 °C vs. 29 °C across lags 0–15 days was 3.40 (1.26, 9.18) and 0.74 (0.31, 1.77) for repeat and first admissions respectively. In the cold season, all admissions increased with falls in temperature, with slightly stronger associations apparent for repeat admissions compared to first admission: 1.20 (1.00, 1.44) vs. 1.10 (0.96, 1.26) respectively comparing risk at 15 °C vs. 12 °C across lags 0–5 days. Conclusions To our knowledge, this is the first study to show stronger associations between ambient temperature and repeat asthma admissions compared to first admissions. The higher sensitivity among those experiencing repeat admissions may allow for more personalized disease management. Given the substantial differences in associations by admission type, future studies of ambient exposures on asthma should consider analyzing the two groups separately. Highlights • About 33% of childhood asthma admissions among the study population were repeat admission cases. • Repeat admissions cases were found significantly more sensitive to high temperature than first admissions. • This study suggested combining first- and repeat- asthma cases in temperature-asthma study may bias the association, in particular under high temperature. [ABSTRACT FROM AUTHOR]

The airborne particulate pollutants originating in the deserts of Mongolia and China which becomes contaminated with industrial effluents and traffic emissions while moving with the wind currents towards East Asia has recently become a serious environmental and health issue in the region. They cause asthma, collateral lung tissue damage, oxidative stress, allergic reactions, and inflammation. The current study was undertaken to evaluate the protective effects of alginate extracted from the invasive alga Sargassum horneri (SHA) against fine dust collected from Beijing, China (Chinese fine dust; CFD). It was found that CFD induces inflammation in HaCaT keratinocytes and inhibits macrophage activation. All of the particulate matter (PM) comprising CFD was < PM13 majority being < PM2.5 which is defined for mineral elements and polycyclic aromatic hydrocarbons. SHA attenuated PGE 2 levels in CFD-induced HaCaT keratinocytes. The IC 50 for SHA was 36.63 ± 4.11 µg mL -l . SHA also reduced the levels of COX-2, IL-6, and TNF-α, and inhibited certain key molecular mediators of the NF-κB and MAPK pathways in keratinocytes. SHA substantially reduced the levels of CFD-derived metal ions like Pb 2+ and Ca 2+ in keratinocytes attributable to its metal ion chelating properties. CFD-induced HaCaT keratinocyte culture media increased inflammatory responses in RAW 264.7 macrophages. These cells presented with increased levels of NO, iNOS, COX-2, PGE 2 , and pro-inflammatory cytokines. It was found that the aforementioned effects could be reversed in RAW 264.7 macrophages when keratinocytes were treated with SHA. Therefore, SHA could be used against fine dust-induced inflammation in keratinocytes. [ABSTRACT FROM AUTHOR]

Increased ambient concentration of particulate matters are considered as one of major causes for increased prevalence or exacerbation of asthma or asthma like symptoms. Recently, possible temporal variation in risks of PM on mortality has been suggested. We investigated short-term effect of both PM 10 and PM 2.5 on asthma hospitalization, and assessed temporal variation of PM risks in Seoul, Korea, 2003–2011. Generalized additive model was used to estimate PM risks on asthma hospitalization with consideration by long-term trend, influenza epidemic, day of week, meteorological factors. To assess temporal variation of PM risks, year-round PM risks were estimated. Stratified analysis by season and age-group were also conducted. Estimated RRs of PM on asthma hospitalization by an increase of 10㎍/㎥were 1.0084 (95% CI: 1.0041–1.0127) and 1.0156 (95% CI: 1.0055–1.0259) respectively with 7-days lag periods (lag06). PM 2.5 had stronger effect than PM 10 for all age group. Elderly group was most affected by PM. For the analysis of temporal variation of PM risks, we found increasing trend in total population and the elderly group. In the season-specific analysis, we also found increasing trend in winter for PM 10 , and in spring for PM 2.5 . PM 10 and PM 2.5 has adverse effect on asthma hospitalization with evidence suggesting temporal variation in PM risks. Further research will be needed to confirm the temporal variation of PM risk on asthma hospitalization, and to identify casual factors affecting this temporal variation. This study results could be evidentiary materials for establishing valid public health policies to reduce health burden or economic burden of asthma. [ABSTRACT FROM AUTHOR]

Linker for activation of T cells (LAT) is a key adaptor in the T cell receptor (TCR) signaling pathway. The expression of LAT is lower in asthmatic patients than that in healthy people, but there is little knowledge about the mechanism underlying this phenomenon. This study was aimed to determine whether LAT-PLC-γ1 interaction was involved in the development of asthma. It was shown that the phosphorylation of PLC-γ1 decreased in the asthmatic mouse model and Th2 cell differentiated CD4+ T cells. In addition, depleted endogenous PLC-γ1 promoted CD4+ T cells to differentiate into IL-4-Productor. It was therefore concluded that the low level of LAT-PLC-γ1 interaction was associated with Th2 polarized differentiation, and this may contribute to the etiology of asthma. [ABSTRACT FROM AUTHOR]

Abstract: The etiology of status asthmaticus (SA), a complication of severe asthma, is unknown. Fungal exposure, as measured by fungal atopy, is a major risk factor for developing asthma, but the relationship of fungi in SA per se has not previously been reported. In this five patient retrospective case series study, lower respiratory tract cultures were performed on bronchoalveolar lavage or tracheal aspirate fluid, comparing standard clinical laboratory cultures with a specialized technique in which respiratory mucus was removed prior to culture. We show that mucolytic treatment allows an increased detection of fungal growth, especially yeast, from the lower airways of all SA patients. We also demonstrate that inhalation of the yeast Candida albicans readily induces asthma-like disease in mice. Our observations suggest that SA may represent a fungal infectious process, and support additional prospective studies utilizing anti-fungal therapy to supplement conventional therapy, broad-spectrum antibiotics and high-dose glucocorticoids, which can promote fungal overgrowth. [Copyright &y& Elsevier]

Abstract: Low income, multi-ethnic communities in Main South/Piedmont neighborhoods of Worcester, Massachusetts are exposed to cumulative, chronic built-environment stressors, and have limited capacity to respond, magnifying their vulnerability to adverse health outcomes. “Neighborhood STRENGTH”, our community-based participatory research (CBPR) project, comprised four partners: a youth center; an environmental non-profit; a community-based health center; and a university. Unlike most CBPR projects that are single topic-focused, our ‘holistic’, systems-based project targeted five priorities. The three research-focused/action-oriented components were: (1) participatory monitoring of indoor and outdoor pollution; (2) learning about health needs and concerns of residents through community-based listening sessions; (3) engaging in collaborative survey work, including a household vulnerability survey and an asthma prevalence survey for schoolchildren. The two action-focused/research-informed components were: (4) tackling persistent street trash and illegal dumping strategically; and (5) educating and empowering youth to promote environmental justice. We used a coupled CBPR-capacity building approach to design, vulnerability theory to frame, and mixed methods: quantitative environmental testing and qualitative surveys. Process and outcomes yielded important lessons: vulnerability theory helps frame issues holistically; having several topic-based projects yielded useful information, but was hard to manage and articulate to the public; access to, and engagement with, the target population was very difficult and would have benefited greatly from having representative residents who were paid at the partners’ table. Engagement with residents and conflict burden varied highly across components. Notwithstanding, we built enabling capacity, strengthened our understanding of vulnerability, and are able to share valuable experiential knowledge. [Copyright &y& Elsevier]