United States Environmental Protection Agency

About: United States Environmental Protection Agency is a government organization based out in Washington D.C., District of Columbia, United States. It is known for research contribution in the topics: Population & Environmental exposure. The organization has 13873 authors who have published 26902 publications receiving 1191729 citations. The organization is also known as: EPA & Environmental Protection Agency.

Transcriptional profiling of mucociliary differentiation in human airway epithelial cells.

Abstract: When cultured at an air-liquid interface (ALI) in the appropriate medium, primary human airway epithelial cells form a polarized, pseudostratified epithelium composed of ciliated and mucus-secreting cells. This culture system provides a useful tool for the in vitro study of airway epithelial biology and differentiation. We have performed microarray analysis on ALI cultures of human bronchial epithelial cells (HBECs) grown over a 28-d period to identify genes involved in mucociliary differentiation. We identified over 2,000 genes that displayed statistically significant 2-fold or greater changes in expression during the time course. Of the genes showing the largest increases, many are involved in processes associated with airway epithelial biology, such as cell adhesion, immunity, transport, and cilia formation; however, many novel genes were also identified. We compared our results with data from proteomic analyses of the ciliary axoneme and identified candidate genes that may have roles in cilia formation or function. Gene networks were generated using Ingenuity Pathways Analysis (Ingenuity Systems, Redwood City, CA) to identify signaling pathways involved in mucociliary cell differentiation or function. Networks containing genes involved in TGF-beta, WNT/beta-catenin, and epidermal growth factor receptor (EGFR) pathways were identified, suggesting potential roles for these families in airway epithelia. Microarray results were validated by real-time RT-PCR for a number of representative genes. This work has provided extensive information about gene expression changes during differentiation of airway epithelial cells, and will be a useful resource for researchers interested in respiratory function, pathology, and toxicology.

Reduction in asthma morbidity in children as a result of home remediation aimed at moisture sources.

Abstract: Asthma is the single most common chronic disease of childhood, affecting > 3 million children in the United States. In addition, the burden of childhood asthma has increased over the past several decades despite the availability of excellent medications for controlling chronic symptoms and treating exacerbations. Moreover, asthma prevalence and morbidity are disproportionately high among inner-city children, most of whom are members of racial minorities. African-American children in the United States have a higher prevalence of asthma and greater morbidity as measured by acute care visits and hospitalizations compared with white children (Kattan et al. 1997; Mannino et al. 2002). The role of the indoor environment in triggering and exacerbating asthma and other respiratory symptoms has been documented in several studies (Daisey et al. 2003; Engvall et al. 2001; Nafstad et al. 1998; Perry et al. 2003; Rosenstreich et al. 1997; Zock et al. 2002; Zureik et al. 2002). High exposures to dust mite, cockroach, and mold have all been implicated in producing respiratory illness, such as infections, cough, and wheeze. Home dampness and the presence of mold have also been associated with asthma, cough, and wheeze (Institute of Medicine 2004). Dust mites, mold, and cockroach are indoor allergens and irritants related to home moisture content, and all are common in urban dwellings (Eggleston et al. 1999; Perry et al. 2003; Rosenstreich et al. 1997). High levels of indoor humidity promote the growth and survival of dust mites. Cockroaches can survive for long periods without food, as long as a water source, such as that from a leaky pipe, is available. Finally, growth of a number of indoor molds (Aspergillus species, Cladosporium, Penicillium, and Stachybotrys) may be promoted by high indoor humidity or water damage (Dales and Miller 1999). In addition to the allergen potential for mold, a number of fungal by-products, such as volatile organic compounds and β-1,2-glucans, may be respiratory irritants (Jaakkola et al. 2005; Rylander 2005). Inner-city children may be at increased risk for asthma morbidity due to exposure to such indoor allergens, because they often spend a large amount of time indoors and live in decaying housing stock that may be prone to water damage. Previous indoor environmental asthma interventions focused on decreasing allergen/irritant exposure by either blocking exposure (use of dust covers) or reducing burden of specific allergen (cockroach abatement) (Evans et al. 1999; Gergen et al. 1999; Morgan et al. 2004; Shapiro et al. 1999; Woodcock et al. 2003). In this pilot program, we explored the effects of remediation of root causes of indoor home moisture and mold on asthma morbidity in inner-city children. Our hypothesis was that use of a home environmental intervention involving construction remediation of sources of moisture and mold damage would significantly decrease asthma symptoms and health care use beyond that achieved by use of a standard asthma intervention alone.

Arsenic exposure from drinking water and birth weight.

Abstract: Background:Arsenic exposures from drinking water increase the risk of various cancers and noncancer health endpoints. Limited evidence suggests that arsenic may have adverse human reproductive effects. We investigated the association between drinking water arsenic exposure and fetal growth, as manif

DNA-based methods for monitoring invasive species: a review and prospectus

Abstract: The recent explosion of interest in DNA-based tools for species identification has prompted widespread speculation on the future availability of inexpensive, rapid, and accurate means of identifying specimens and assessing biodiversity. One applied field that may benefit dramatically from the development of such technologies is the detection, identification, and monitoring of invasive species. Recent studies have demonstrated the feasibility of DNA-based tools for such important tasks as confirmation of specimen identity and targeted screening for known or anticipated invaders. However, significant technological hurdles must be overcome before more ambitious applications, including estimation of propagule pressure and comprehensive surveys of complex environmental samples, are to be realized. Here we review existing methods, examine the technical difficulties associated with development of more sophisticated tools, and consider the potential utility of these DNA-based technologies for various applications relevant to invasive species monitoring.

Evaluating uncertainty in integrated environmental models: A review of concepts and tools

Abstract: [1] This paper reviews concepts for evaluating integrated environmental models and discusses a list of relevant software-based tools. A simplified taxonomy for sources of uncertainty and a glossary of key terms with ‘‘standard’’ definitions are provided in the context of integrated approaches to environmental assessment. These constructs provide a reference point for cataloging 65 different model evaluation tools. Each tool is described briefly (in the auxiliary material) and is categorized for applicability across seven thematic model evaluation methods. Ratings for citation count and software availability are also provided, and a companion Web site containing download links for tool software is introduced. The paper concludes by reviewing strategies for tool interoperability and offers guidance for both practitioners and tool developers.