Science.gov

Sample records for prolonged ozone exposure

  1. RESPIRATORY RESPONSES TO REPEATED PROLONGED EXPOSURE TO 0.12 PPM OZONE

    EPA Science Inventory

    Repeated exposures to high concentrations of ozone results first in augmentation and then attenuation of pulmonary response in humans. o determine the effects of repeated prolonged low concentration ozone exposure, we exposed 17 healthy nonsmoking males to 0.12 ppm ozone for 6.6 ...

  2. Chronic bronchiolitis in nonhuman primates after prolonged ozone exposure

    SciTech Connect

    Eustis, S.L.; Schwartz, L.W.; Kosch, P.C.; Dungworth, D.L.

    1981-01-01

    Bonnet monkeys (Macaca radiata) were exposed to 0.0, 0.5, or 0.8 ppm ozone for 7, 28, or 90 consecutive days, 8 hours per day. The pulmonary response was evaluated by means of pulmonary function testing, light microscopy, scanning electron microscopy, transmission microscopy, autoradiography, and morphometry. Pulmonary function values obtained before exposure did not statistically differ from values obtained after exposure. A general trend of increased quasistatic compliance of the lung was observed in both groups of exposed monkeys. Morphologic changes were principally characterized as low-grade chronic respiratory bronchiolitis. Tritiated thymidine labeling and counts of respiratory bronchiolar epithelium demonstrated up to a 37-fold increase in labeling index at 7 days but only a sevenfold increase at 90 days. Differential cell counts demonstrated an increase in the proportion of cuboidal bronchiolar cells constituting the respiratory bronchiolar epithelium. In control monkeys, 60% of the epithelial cells were cuboidal bronchiolar cells. At 90 days of exposure, more than 90% of the respiratory bronchiolar cells were cuboidal in appearance. The cuboidal bronchiolar cell in control monkeys does not appear secretory, but membrane-bound electron-dense secretory granules are present in this cell type from exposed monkeys. Epithelial hyperplasia (increased number of cells per millimeter of airway length) persisted through 90 days of exposure at a level slightly above that present at 7 days.

  3. Responses of older men with and without chronic obstructive pulmonary disease to prolonged ozone exposure

    SciTech Connect

    Gong, H. Jr.; Shamoo, D.A.; Anderson, K.R.; Linn, W.S.

    1997-01-01

    We tested responses to ozone (O{sub 3}) under simulated {open_quotes}worst-case{close_quotes} ambient exposure conditions. Subjects included 9 men who had severe chronic obstructive pulmonary disease (COPD) with subnormal carbon monoxide diffusing capacity (i.e., an emphysemic component) and 10 age-matched healthy men. Each subject was exposed to 0.24 ppm O{sub 3} and to clean air (control) in an environmentally controlled chamber at 24{degrees}C and 40% relative humidity. Exposures were randomized, they occurred 1 wk apart, and they lasted 4 h. During each half-hour interval, light exercise occurred (e.e., average ventilation 20 l/mm) for 15 min. during both control and O{sub 3} exposures, group mean symptom intensity and specific airway resistance (SRaw) increased, whereas forced expiratory performance decreased. The healthy subgroup`s mean arterial oxygen saturation (SaO{sub 2}) rose slightly, and the COPD subgroup`s mean SaO{sub 2} declined slightly, during exercise. Group mean forced expiratory volume in 1 s (FEV{sub 1.0}) declined significantly in O{sub 3} exposures, compared with controls (p {approx}.01). Mean excess FEV{sub 1.0} loss after 4 h in O{sub 3} (relative to control) was 8% of the preexposure value in the COPD subgroup, compared with 3% in the healthy subgroup (p > .05 [nonsignificant]). Overall FEV{sub 1.0} loss during O{sub 3} exposures, including exercise effects, averaged 19% in the COPD subgroup, compared with 2% in the healthy subgroup (p < .001). Symptoms, SRaw, and SaO{sub 2} responses, as well as healthy subjects` postexposure bronchial reactivity, differed little between O{sub 3}-exposed and control subjects. We therefore concluded that in older men with or without severe COPD, O{sub 3} causes lung dysfunction under {open_quotes}worst-case{close_quotes} ambient exposure conditions, despite older subjects` comparative unresponsiveness to O{sub 3}. 30 refs., 2 figs., 2 tabs.

  4. MORPHOLOGICAL EFFECTS OF PROLONGED EXPOSURE TO OZONE AND SULFURIC ACID AEROSOL ON THE RAT LUNG

    EPA Science Inventory

    The purpose of this study was to determine the pulmonary effects of a combination of ozone (0.5 ppm) and sulfuric acid aerosol (1 mg/cu. m.) and to assess the possibility of interactive effects. Groups of Sprague-Dawley rats were continously exposed to the pollutants, either indi...

  5. PROLONGED EXPOSURE OF HUMANS TO AMBIENT LEVELS OF OZONE CAUSES CELLULAR AND BIOCHEMICAL CHANGES IN THE LUNG

    EPA Science Inventory

    An acute (2h) exposure of humans to 0.4 ppm ozone initiates biochemical changes in the lung resulting in the production of components which mediate inflammation and acute lung damage as well as components which have the potential to lead to long term effects such as fibrosis. owe...

  6. CHANGES IN PULMONARY FUNCTION AND AIRWAY REACTIVITY DUE TO PROLONGED EXPOSURE TO TYPICAL AMBIENT OZONE (O3) LEVELS

    EPA Science Inventory

    Daily ambient ozone levels between 0.08 and 0.12 ppm for periods exceeding 6 hours often occur in many urban, suburban, and rural areas of the United States and Europe. Substantial decrements in pulmonary functions, moderate to severe respiratory symptoms, and increased airway re...

  7. Effects of prolonged, sequential exposure to acid fog and ozone on pulmonary function in exercising, normal subjects. Final report, 28 Feb 89-28 Dec 90

    SciTech Connect

    Balmes, J.

    1990-05-01

    Thirty-nine apparently healthy and asymptomatic subjects were selected for a study that screened for sensitivity to ozone. After three hours of ozone exposure (at 0.20 ppm), eighteen of the subjects (46 percent) experienced a 10 percent reduction in forced expiratory volume, an indicator of exhaling ability. After four hours of exposure, 62 percent of the subjects experienced a similar reduction in expiratory volume. Further, narrowing of airways among the sensitive subjects was suggested by results of the methacholine challenge test, a standard test for measuring airway resistance. The lung capacity of all subjects decreased progressively during ozone exposures. Capacity was unchanged during acidic fog and pollutant-free air exposures. No statistically significant differences in airway resistance, airway responsiveness and symptoms that could be attributed to acid fog exposure were observed. The study indicates that exposue to fog containing nitric acid followed by exposure to ozone does not have additive or synergistic acute effects. However, the study confirms earlier indications that many apparently healthy and asymptomatic individuals are susceptible to and adversely affected by ozone at relatively low concentrations.

  8. Prolonged stimulus exposure reveals prolonged neurobehavioral response patterns.

    PubMed

    Johnson, Brett A; Woo, Cynthia C; Zeng, Yu; Xu, Zhe; Hingco, Edna E; Ong, Joan; Leon, Michael

    2010-05-15

    Although it has been shown repeatedly that minimum response times in sensory systems can be quite short, organisms more often continue to respond to sensory stimuli over considerably longer periods of time. The continuing response to sensory stimulation may be a more realistic assessment of natural sensory responses, so we determined for how long a stimulus would evoke a response in naïve, freely moving animals. Specifically, we determined for how long such rats responded to odorants during continuous passive exposures by monitoring their sniffing with whole-body plethysmography. We found that naïve rats continue to sniff odorants vigorously for up to 3 minutes, much longer than what has been reported for highly trained, highly motivated rats. Patterns of 2-deoxyglucose (2-DG) uptake in the glomerular layer of the rat olfactory bulb also were seen after only 1-5 minutes of odorant exposure, overlapping with the period of increased respiration to odorants. Moreover, these 2-DG uptake patterns closely resembled the patterns that emerge from prolonged odorant exposures, suggesting that activity mapping over prolonged periods can identify areas of activity that are present when rats are still attending and responding to odorant stimuli. Given these findings, it seems important to consider the possibility that prolonged exposure to other sensory stimuli will reveal more realistic neural response patterns. PMID:20232477

  9. Ozone exposure: a case report and discussion.

    PubMed

    Parks, S; Paul, D W

    2000-02-01

    A 45-year-old man working with ozone presents with evidence of sinusitis, mucus membrane irritation, sleep disturbance and shortness of breath. Naturally occurring or manmade, ozone may damage pulmonary alveolar type I cells at significant exposure levels. EPA and OSHA regulate exposure concentrations. Studies show dose responses with exposures. Supporting epidemiological studies are reviewed briefly. Limiting potential for excess exposure is key to prevention. Recognition of ozone as a potential exposure in the Oklahoma workplace is key to symptom management. PMID:10692811

  10. HUMAN EXPOSURE SYSTEM FOR CONTROLLED OZONE ATMOSPHERES

    EPA Science Inventory

    An experimental exposure system for health effects research in environmental pollutants that permits the introduction and control of ozone (O3) to an acrylic plastic chamber in which a human subject actively resides is described. Ozone is introduced into the chamber air intake an...

  11. Ozone exposure : Areas of potential ozone risk for selected tree species in Austria.

    PubMed

    Loibl, W; Smidt, S

    1996-12-01

    Increased tropospheric ozone concentrations cause damage to both human health and the environment. To assess the exposure of forest areas and selected tree species to ozone, it is necessary to calculate the ozone exposure distribution. The present article describes the application of an ozone interpolation model to the calculation of the ozone exposure distribution in combination with forest inventory data.The exposure of forest regions to ozone was assessed by means of an AOT40 map (accumulated ozone exposure over a threshold of 40 ppb). The calculation was performed by hourly running of the model during the summer term and accumulation of the patterns that exceeded 40 ppb.The exposure of the primary Austrian tree species to ozone can be assessed due to the spatial relation of ozone exposure and tree species patterns. This spatial relation also allows the verification of assumptions concerning ozone-related tree damage. PMID:24233419

  12. Influenza virus infection, ozone exposure, and fibrogenesis.

    PubMed

    Jakab, G J; Bassett, D J

    1990-05-01

    Oxidant exposure following chemically induced lung injury exacerbates the tendency to develop pulmonary fibrosis. Influenza virus pneumonitis causes severe acute lung damage that, upon resolution, is followed by a persistent alveolitis and parenchymal changes characterized by patchy interstitial pneumonia and collagen deposition in the affected areas. To determine whether oxidant exposure exacerbates the virus-induced alveolitis and residual lung damage, mice were infected by aerosol inhalation with influenza A virus and continuously exposed to 0.5 ppm ozone or ambient air. Noninfected control mice were exposed to either ambient air or ozone. On various days during the first month after infection, groups of mice were sacrificed and their lungs assessed for acute injury (lung lavage albumin, total and differential cell counts, wet/dry ratios, and morphometry). At 30, 60, 90, and 120 days after infection, groups of mice were sacrificed for total and differential lavage cell counts, lung hydroxyproline content, and morphometric analysis. Ozone exposure did not alter the proliferation of virus in the lungs as quantitated by infectious virus titers of lung homogenates at 1, 4, 7, 10, and 15 days after virus infection but mitigated the virus-induced acute lung injury by approximately 50%. After Day 30 a shift in the character of the pulmonary lesions was observed in that continuous exposure to ozone potentiated the postinfluenzal alveolitis and structural changes in the lung parenchyma. Additional studies suggest that the mechanism for the enhanced postinfluenzal lung damage may be related to the oxidant impairing the repair process of the acute influenzal lung damage. These data demonstrate that ozone exposure mitigates acute virus-induced lung injury and potentiates residual lung damage. PMID:2339849

  13. AN HISTORICAL OVERVIEW OF THE OZONE EXPOSURE PROBLEM

    EPA Science Inventory

    Ozone can be found in essentially all locations in the troposphere. Too much exposure of vegetation and humans to this potent oxidizing gas can prove toxic. Reports of human toxicity to ozone first appeared in the 1800's from accidental occupational exposures when ozone was fir...

  14. CHANGES IN COMPLEX CARBOHYDRATE CONTENT AND STRUCTURE IN RAT LUNGS CAUSED BY PROLONGED OZONE INHALATION

    EPA Science Inventory

    EPA GRANT NUMBER: R828112C065III
    Title: Changes in Complex Carbohydrate Content and Structure in Rat Lungs Caused by Prolonged Ozone Inhalation
    Investigator: Bhandaru Radhakrishnamurthy
    Institution: Tulane University of Louisiana
    EPA...

  15. Ecosystem Consequences of Prolonged Ozone Pollution in the Southern Sierra Nevada

    NASA Astrophysics Data System (ADS)

    Cousins, S.; Battles, J. J.; Cisneros, R.; Esperanza, A.; Swenson, D.

    2015-12-01

    While acute O3 exposure is widely known to damage plant tissues, the chronic effects on long lived organisms such as trees remain unclear. In the southern Sierra Nevada, O3 pollution has afflicted pine-dominated forests for over 40 years. Here we report the results of a long-term study of O3 impact on tree injury, growth, and mortality. Our study employed a network of forest plots along a gradient of O3 pollution with recurring measurements from 1991-2012. Over the same period and locations, summer O3 was monitored via partnership with USNPS and USFS, making this one of the longest known ecosystem studies of O3 pollution and its effects. We found that exposure at the most polluted sites declined 33%, from a W126 index of 20.12 ppm-hrs in 1992 to 13.5 ppm-hrs in 2012. The severity of foliar pollution damage at these sites also declined, from 43.9 on the 0-100 Ozone Injury Index (OII) scale to 34.2, a drop of 22%. At locations with lower O3 exposure, damage declined from OII of 16.9 to 9.2. Mean annual tree mortality rates over the 20 year period, calculated with a profile likelihood approach, were 0.5%/yr (95% CI 0.3 to 0.8 %/yr). This rate is similar to that of healthy canopy trees in similar unpolluted stands. However, low and declining tree growth rates reveal possible ecosystem impacts of prolonged exposure to pollution. Across affected sites, mean relative growth rates were 1.1%/yr in 1991-2000, and just 0.9%/yr in 2000-2011, a decline of 15.6% in the second decade. Initial analyses suggest that tree damage is positively correlated with June-October O3, as indicated by previous studies. Further analysis will explore the drivers of ecosystem impacts and roles of other natural and anthropogenic stressors, including variation in climatic water deficit. Understanding the consequences of prolonged O3 exposure on both individual trees and complex forest ecosystems helps identify the hidden environmental costs of tropospheric O3 and potential benefits of cleaner air.

  16. The effects of prolonged exposure to weightlessness on postural equilibrium

    NASA Technical Reports Server (NTRS)

    Homick, J. L.; Reschke, M. F.; Miller, E. F., II

    1977-01-01

    A postflight postural equilibrium rail tests on spacecrews was used to prove a pronounced decrement in ability to maintain an upright posture after prolonged exposure to weightlessness. Support for the hypothesis that central neural reorganization occurs in response to environmental change is obtained when postflight decrease in stability on the rails and the time course for recovery are compared with preflight performance.

  17. Cognitive Changes During Prolonged Exposure versus Prolonged Exposure Plus Cognitive Restructuring in Female Assault Survivors with Posttraumatic Stress Disorder

    ERIC Educational Resources Information Center

    Foa, Edna B.; Rauch, Sheila A. M.

    2004-01-01

    The authors report on changes in cognitions related to posttraumatic stress disorder (PTSD) among 54 female survivors of sexual and nonsexual assault with chronic PTSD who completed either prolonged exposure alone or in combination with cognitive restructuring. Treatment included 9-12 weekly sessions, and assessment was conducted at pretreatment,…

  18. A new PZT with prolonged exposure and Wuchang PZT catalogue.

    NASA Astrophysics Data System (ADS)

    Gao, Buxi; Li, Jingfeng; Hu, Yashe

    The most important improvement in the authors' PZT is that the stars with 11 mag. can be observed, because exposure time for dimmer stars is prolonged. The observational practice during last three years denotes that the method of prolonged exposure is very successful. The number of observed stars is increased about three times, and the precision is improved. As there are so many star images in the plate, a series of processes is suggested, which includes the process of predicting the positions of star images on plates, finding out the pairs of star images and their corresponding stars automatically, calculating the apparent positions of stars and giving the final observational results. The corrections of 289 stars (on 150 measured plates) are given. The results show that many errors of stellar positions in AGK 3R and AGK 3 are larger than 0″5.

  19. Exposure to Environmental Ozone Alters Semen Quality

    PubMed Central

    Sokol, Rebecca Z.; Kraft, Peter; Fowler, Ian M.; Mamet, Rizvan; Kim, Elizabeth; Berhane, Kiros T.

    2006-01-01

    Idiopathic male infertility may be due to exposure to environmental toxicants that alter spermatogenesis or sperm function. We studied the relationship between air pollutant levels and semen quality over a 2-year period in Los Angeles, California, by analyzing repeated semen samples collected by sperm donors. Semen analysis data derived from 5,134 semen samples from a sperm donor bank were correlated with air pollutant levels (ozone, nitrogen dioxide, carbon monoxide, and particulate matter < 10 μm in aerodynamic diameter) measured 0–9, 10–14, and 70–90 days before semen collection dates in Los Angeles between January 1996 and December 1998. A linear mixed-effects model was used to model average sperm concentration and total motile sperm count for the donation from each subject. Changes were analyzed in relationship to biologically relevant time points during spermatogenesis, 0–9, 10–14, and 70–90 days before the day of semen collection. We estimated temperature and seasonality effects after adjusting for a base model, which included donor’s date of birth and age at donation. Forty-eight donors from Los Angeles were included as subjects. Donors were included if they collected repeated semen samples over a 12-month period between January 1996 and December 1998. There was a significant negative correlation between ozone levels at 0–9, 10–14, and 70–90 days before donation and average sperm concentration, which was maintained after correction for donor’s birth date, age at donation, temperature, and seasonality (p < 0.01). No other pollutant measures were significantly associated with sperm quality outcomes. Exposure to ambient ozone levels adversely affects semen quality. PMID:16507458

  20. Media Impacts on Women's Fertility Desires: A Prolonged Exposure Experiment.

    PubMed

    Knobloch-Westerwick, Silvia; Willis, Laura E; Kennard, Ashley R

    2016-06-01

    Media exposure may have implications for family planning, a public health issue of key importance. Drawing on social comparison theory and social identity theory, a prolonged exposure experiment examined whether media portrayals of women's social roles affect fertility desires among 166 American, nonstudent, never married, childless women ages 21-35 years old. After sign-up and baseline sessions, participants viewed magazine pages five days in a row. Stimuli presented women in either mother/homemaker roles, beauty ideal roles, or professional roles. Three days later, participants again indicated their number of desired children and time planned until first birth. Exposure to mother/homemaker and beauty ideal portrayals increased the number of desired children across time. Exposure to professional portrayals increased the time planned until 1st birth compared to beauty ideal portrayals-this impact was partially mediated by a shift toward more progressive gender norms (per social identity theory) and assimilation (per social comparison theory). PMID:27166510

  1. LUNG INJURY AFTER OZONE EXPOSURE IS IRON-DEPENDENT

    EPA Science Inventory

    We tested the hypothesis that oxidative stress and biological effect after ozone (O3) exposure are dependent on changes in iron homeostasis. After O3 exposure, healthy volunteers demonstrated increased lavage concentrations of iron, transferrin, lactoferrin, and ferritin. In norm...

  2. EFFICACY OF OZONE EXPOSURE INDICES IN THE STANDARD SETTING PROCESS

    EPA Science Inventory

    Determining the appropriate ozone exposure index for a secondary ambient air quality standard requires a consideration of the underlying biological basis for the response and a method of describing the temporal fluctuations in pollutant concentrations. An exposure index that adeq...

  3. Immunosuppression of pulmonary natural killer activity by exposure to ozone

    SciTech Connect

    Burleson, G.R.; Keyes, L.L.; Stutzman, J.D. )

    1989-01-01

    Ozone is an oxidant gas and an ubiquitous oxidant air pollutant with the potential to adversely affect pulmonary immune function with a consequent increase in disease susceptibility. Pulmonary natural killer (NK) activity was measured in order to assess the pulmonary immunotoxicity of continuous ozone exposure. Continuous ozone exposures at 1.0 ppm were performed for 23.5 hours per day for either 1, 5, 7, or 10 consecutive days. Pulmonary immune function was assessed by measuring natural killer (NK) activity from whole-lung homogenates of male Fischer-344 rats. Results of this study indicated that continuous ozone exposure for 1, 5, or 7 days resulted in a significant decrease in pulmonary NK activity. This suppressed pulmonary NK activity returned to control levels after continuous exposure to ozone for 10 days. The suppressed pulmonary NK response was thus attenuated and returned to normal values in the continued presence of ozone gas. This attenuation process is dynamic, complex, and doubtless involves several cell types and/or products of these cells. Pulmonary NK activity was also suppressed at 0.5 ppm ozone, but not at 0.1 ppm ozone, following 23.5 hours of exposure. NK activity is important for defense against viral, bacterial, and neoplastic disease. The depressed NK activity resulting from continuous ozone exposure could therefore result in a compromised ability to defend against pulmonary diseases.

  4. Pulmonary function and clearance after prolonged sulfuric acid aerosol exposure

    SciTech Connect

    Ives, P.J. ); Gerrity, T.R.; DeWitt, P.; Folinsbee, L.J. )

    1991-03-15

    The authors studied pulmonary function and clearance responses after a 4 H exposure to 75-100 {mu}g/m{sup 3} sulfuric acid aerosol (SAA). Healthy subjects, who exercised for 30 min/H at ventilation of about 25 L/min, were exposed once to clean air and once to SAA. Oral hygiene and acidic juice gargle were used to minimize oral ammonia. Lung function tests, including spirometry, plethysmography, and partial flow-volume (PEFV) curves were performed before and after exposure. Clearance of 99m-Technetium labeled iron oxide was assessed after each exposure. The first moment of fractional tracheobronchial retention (M1TBR), after correcting for 24 H retention and normalizing to time zero, was used as an index of clearance. There were no significant changes in lung volumes, airways resistance, or maximum expiratory flows after SAA exposure. Flow at 40% of total lung capacity on PEFV curves decreased 17% (NS) after SAA exposure. Tracheobronchial clearance was accelerated after a single exposure to SAA; M1TBR decreased from 73 {plus minus} 5 min (air) to 69 {plus minus} 5 min (SAA). These results suggest that acute prolonged exposure to low levels of SAA has minimal effects on lung mechanics in healthy subjects but does produce a modest acceleration of particle clearance.

  5. Ozone exposure of human tracheal epithelial cells inactivates cyclooxygenase and increases 15-HETE production.

    PubMed

    Alpert, S E; Walenga, R W

    1995-12-01

    We assessed the immediate and prolonged effects of ozone on arachidonic acid (AA) metabolism by primary cultured human tracheal epithelial (TE) cells. TE monolayers were exposed at a gas-fluid interface to air or 0.1, 0.25, or 0.5 ppm ozone (15 min air, then 45 min air/ozone), and serially collected effluents were analyzed by thin-layer chromatography (TLC) and/or high-performance liquid chromatography. Release of prostaglandin E2 (PGE2) and AA, but not 15-hydroxyeicosatetraenoic acid (15-HETE) or its metabolites, was detected from cultures prelabeled with [14C]AA. PGE2 production, measured by immunoassay, was nearly constant during air exposure. In contrast, PGE2 increased two- to threefold during the first 15-min exposure to all concentrations of ozone, but then progressively declined to 78 +/- 17, 57 +/- 12 (P < or = 0.05), and 45 +/- 15% (P < or = 0.05) of air controls after exposure to 0.1, 0.25, and 0.5 ppm ozone. Ozone did not induce a new spectrum of AA metabolites; only PGE2, lesser amounts of PGF2 alpha, and 15-HETE were present in media and cell extracts of air- or ozone-exposed cultures provided with 30 microM exogenous AA. However, cyclooxygenase (CO) activity (PGE2 produced from 30 microM AA) decreased to 82 +/- 9, 53 +/- 8 (P < or = 0.05), and 28 +/- 6% (P < or = 0.05) vs. controls after 0.1, 0.25, and 0.5 ppm ozone, whereas 15-HETE production was unimpaired. When cells exposed to 0.5 ppm ozone were maintained for up to 6 h in 5% CO2-air, spontaneous PGE2 production remained decreased and recovery of CO activity was extremely slow. TLC analysis of lipid extracts from [14C]AA-labeled cells revealed a nearly twofold increase in free intracellular 15-HETE, and hydrolysis of phospholipids demonstrated increased esterified 15-HETE. Exposure of human TE cells to ozone leads to a transient increase followed by prolonged decrease in PGE2 production and increased intracellular retention of 15-HETE. Loss of the bronchodilator and anti-inflammatory properties

  6. OZONE EXPOSURE AND PULMONARY METABOLIC EFFECTS OF MEDIATORS AND HORMONES

    EPA Science Inventory

    Several physiological effects of ozone exposure involving smooth muscle contracting substances have been studied in Sprague-Dawley derived, male rats whose body weights were in the range of 180-250 grams and whose ages were in the range of 45-60 days. The ozone concentration of i...

  7. PREDICTORS OF INDIVIDUAL DIFFERENCES IN ACUTE RESPONSE TO OZONE EXPOSURE

    EPA Science Inventory

    The purposes of this study were to identify personal characteristics which predict individual differences in acute response to ozone exposure and to develop a predictive model for decrements in FEV1 as a function of ozone concentration and individual predictors. esponse and predi...

  8. Long-term ozone exposure and ozone uptake of grapevines in open-top chambers

    NASA Astrophysics Data System (ADS)

    Soja, G.; Reichenauer, T. G.; Eid, M.; Soja, A.-M.; Schaber, R.; Gangl, H.

    Ozone uptake of pot-grown grapevines, fruit yield and sugar concentrations in juice were studied over the course of 4 years. In three of the study years, plants were exposed to contrasting ozone levels in open-top chambers. Results showed that juice quality was more sensitive to ozone exposure than grape yield. Ozone-induced reductions in grape yield were best described by the level of ozone exposure in the 2 years prior to harvest, whereas sugar content of juice was mainly affected by current and previous year ozone exposure. Regression models were developed to facilitate quantitative assessments of the effects of ozone on yield and quality. The observed effects on grape yield and on carbohydrate accumulation in fruit were slightly better explained when a threshold of 6 nmol m -2 s -1 was applied to cumulative uptake of ozone (CUO6) compared with AOT40 exposure or other CUO thresholds. Curvilinear regression models were developed which explained up to 75% of variance of the datasets. These models indicate a critical level of 1.1 mmol m -2 ozone (CUO6 from June to September) to protect carbohydrate accumulation in fruit with ozone taken up by the plants over consecutive years. For grape yield the CUO6 threshold was 2.2 mmol m -2 ozone. Exceedance of this threshold would be expected to reduce grape yield and sugar translocation to fruit by 10% with substantial degree of uncertainty (95% confidence interval 1-19%). For individual years, the critical level could be increased to 2.3 mmol m -2 for carbohydrate accumulation and 3.5 mmol m -2 CUO6 for grape yield if the CUO6 of 0 in the subsequent year was not exceeded.

  9. PARAMETER EVALUATION AND MODEL VALIDATION OF OZONE EXPOSURE ASSESSMENT USING HARVARD SOUTHERN CALIFORNIA CHRONIC OZONE EXPOSURE STUDY DATA

    EPA Science Inventory

    To examine factors influencing long-term ozone exposures by children living in urban communities, we analyzed longitudinal data on personal, indoor, and outdoor ozone concentrations as well as related housing and other questionnaire information collected in the one-year-long Harv...

  10. Persistence of the acute effects of ozone exposure

    SciTech Connect

    Folinsbee, L.J.; Horvath, S.M.

    1986-12-01

    Reexposure to ozone 24 h after an initial exposure results in greater decreases in forced expiratory tests of lung function following the second exposure. The purpose of this study was to determine whether this hyperresponsiveness was present earlier than 24 h or persisted beyond 24 h. Four groups of subjects (n = 6,6,7,7) were exposed to 0.25 ppm ozone and then reexposed at 12, 24, 48, or 72 h, respectively. During the 1-h exposures (Ta = 20 degrees C, RH = 70%) all subjects exercised continuously at approximately 65% of their respective peak VO2; VE averaged 63 L X min-1. The decrease in FEV1.0 after the second ozone exposure was significantly larger than that after the first for subjects reexposed at 12 or 24 h; FEV1.0 dropped 12% and 19% in the 12 h group, and 20% and 35% in the 24 h group. Subjects reexposed at 48 or 72 h had FEV1.0 responses which were not significantly different from the first exposure. Delta FEV1.0 on the first and second exposures were significantly correlated (r = 0.59). Symptoms generally paralleled changes in function. We conclude that the hyperresponsiveness to ozone following exposure to 0.25 ppm ozone under the conditions of this study is apparent within 12 h and is not present at 72 h.

  11. EVALUATION OF OZONE EXPOSURE INDICES FOR RELATING EXPOSURE TO PLANT PRODUCTION AND FOR ESTIMATING AGRICULTURAL LOSSES

    EPA Science Inventory

    The objective of the report is: (1) to compare alternative ozone exposure indices that relate well to plant response and are useful in developing future standards for ozone; (2) to estimate standard errors and confidence intervals of regression coefficients and exposure levels of...

  12. Interannual Variability of Ozone and Ultraviolet Exposure

    NASA Technical Reports Server (NTRS)

    Herman, J. R.; Piacentini, R. D.; Ziemke, J.; Celarier, E.; Larko. D.

    1999-01-01

    Annual zonal averages of ozone amounts from Nimbus-7/TOMS (Total Ozone Mapping Spectrometer) (1979 to 1992) are used to estimate the interannual variability of ozone and UVB (290 - 315 nm) irradiance between plus or minus 60 deg. latitude. Clear-sky interannual ozone and UVB changes are mainly caused by the Quasi Biennial Oscillation (QBO) of stratospheric winds, and can amount to plus or minus 15% at 300 nm and plus or minus 5% at 310 nm (or erythemal irradiance) at the equator and at middle latitudes. Near the equator, the interannual variability of ozone amounts and UV irradiance caused by the combination of the 2.3 year QBO and annual cycles implies that there is about a 5-year periodicity in UVB variability. At higher latitudes, the appearance of the interannual UVB maximum is predicted by the QBO, but without the regular periodicity. The 5-year periodic QBO effects on UVB irradiance are larger than the currently evaluated long-term changes caused by the decrease in ozone amounts.

  13. Exposure to ozone reduces influenza disease severity and alters distribution of influenza viral antigens in murine lungs.

    PubMed

    Wolcott, J A; Zee, Y C; Osebold, J W

    1982-09-01

    Exposure to ambient levels of ozone (0.5 ppm) was shown to alter the pathogenesis of respiratory infection after aerosol infection of mice with influenza A virus. A semiquantitative method for determination of the sites of virus replication by direct immunofluorescence indicated that exposure to ozone reduced the involvement of respiratory epithelium in the infectious process and resulted in a less widespread infection of the alveolar parenchyma. Furthermore, the ozone-mediated alteration in viral antigen distribution was consistent with significantly reduced influenza disease mortality and prolonged survival time, but only when the oxidant was present during the course of infection. Reduced disease severity in ozone-exposed animals appeared to be independent of peak pulmonary virus titers, pulmonary interferon titers, and pulmonary and serum-neutralizing antibody titers. These studies suggested that the distribution of influenza virus in the murine lung was a key factor in disease severity. PMID:6182839

  14. Exposure to ozone and erythrocyte osmotic resistance in the rat

    SciTech Connect

    Ikemi, Y.; Ohmori, K.; Ito, T.; Osaka, F.; Matuura, Y. )

    1992-10-01

    In order to learn the biological effect of photochemical oxidants on living bodies, we exposed newborn and adult rats, of both sexes, to ozone at a concentration of 0.25 ppm, which can be encountered in an urban environment, and then measured the osmotic resistance of their erythrocytes. The results of experiments using newborn rats indicated a positive increase in the osmotic resistance of erythrocytes in whole blood following ozone exposure for 4 weeks. An increase in the osmotic resistance of erythrocytes in the top part obtained by centrifugation was observed following ozone exposure for 12 weeks. This tendency was especially evident among male rats. On the other hand, no increase in the osmotic resistance of erythrocytes was recognized in the adult animals which had been exposed to the same concentration of ozone for 18 months.

  15. Examining potential contraindications for prolonged exposure therapy for PTSD

    PubMed Central

    van Minnen, Agnes; Harned, Melanie S.; Zoellner, Lori; Mills, Katherine

    2012-01-01

    Although prolonged exposure (PE) has received the most empirical support of any treatment for post-traumatic stress disorder (PTSD), clinicians are often hesitant to use PE due to beliefs that it is contraindicated for many patients with PTSD. This is especially true for PTSD patients with comorbid problems. Because PTSD has high rates of comorbidity, it is important to consider whether PE is indeed contraindicated for patients with various comorbid problems. Therefore, in this study, we examine the evidence for or against the use of PE with patients with problems that often co-occur with PTSD, including dissociation, borderline personality disorder, psychosis, suicidal behavior and non-suicidal self-injury, substance use disorders, and major depression. It is concluded that PE can be safely and effectively used with patients with these comorbidities, and is often associated with a decrease in PTSD as well as the comorbid problem. In cases with severe comorbidity, however, it is recommended to treat PTSD with PE while providing integrated or concurrent treatment to monitor and address the comorbid problems. PMID:22893847

  16. Morphological study of the effects of ozone on rat lung. II. Long-term exposure

    SciTech Connect

    Hiroshima, K.; Kohno, T.; Ohwada, H.; Hayashi, Y.

    1989-04-01

    To evaluate the morphological changes observed in animals after prolonged ozone exposure, 56 male rats were exposed to a high ambient level of ozone (0.5 ppm) 6 hr a day, 6 days a week, for 2, 3, 5, and 12 months and examined by light and electron microscopy. Bronchitis and peribronchitis were observed throughout the exposure periods, and connective tissue around the bronchi thickened as a result of fibrosis. Some bronchiolar ciliated cells were in a degenerated condition and others in a reparative phase. Hyperplastic nodules were not found in the bronchioles, but hyperplasia of the bronchiolar epithelium was observed. Hyperplasia of lymphoid nodules around small vessels was prominent after 2 months of exposure. After 3 months of exposure, alveolar ducts were lined by type 2 cells, and after 12 months, by the bronchiolar epithelium consisting of both ciliated and nonciliated cells. Alveolar macrophages accumulated in the centriacinar alveoli. Fibrous strands were seen to be deposited in alveolar ducts after 3 months, and in bronchioles after 5 months. This fibrosis was due to an increment in collagen fibers. The degree of fibrosis increased with the length of ozone exposure.

  17. The role of ozone exposure in the epidemiology of asthma

    SciTech Connect

    Balmes, J.R.

    1993-12-01

    Asthma is a clinical condition characterized by intermittent respiratory symptoms, nonspecific airway hyperresponsiveness, and reversible airway obstruction. Although the pathogenesis of asthma is incompletely understood, it is clear that airway inflammation is a paramount feature of the condition. Because inhalation of ozone by normal, healthy subjects causes increased airway responsiveness and inflammation, it is somewhat surprising that most controlled human exposure studies that have involved asthmatic subjects have not shown them to be especially sensitive to ozone. The acute decrement in lung function that is the end point traditionally used to define sensitivity to ozone in these studies may be due more to neuromuscular mechanisms limiting deep inspiration than to bronchoconstriction. The frequency of asthma attacks following ozone exposures may be a more relevant end point. Epidemiologic studies, rather than controlled human exposure studies, are required to determine whether ozone pollution increases the risk of asthma exacerbations. Asthma affects approximately 10 million people in the United States and, thus, the answer to this question is of considerable public health importance. Both the prevalence and severity of asthma appear to be increasing in many countries. Although increased asthma morbidity and mortality are probably of multifactorial etiology, a contributory role of urban air pollution is plausible. The epidemiologic database to support an association between asthma and ozone exposure is limited, but the results of several studies suggest such an association. Some potential approaches to further investigation of the relationship between asthma and ozone, including those that would link controlled human exposures to population-based studies, are considered. 57 refs.

  18. Exposure-Relevant Ozone Chemistry in Occupied Spaces

    SciTech Connect

    Coleman, Beverly Kaye

    2009-04-01

    Ozone, an ambient pollutant, is transformed into other airborne pollutants in the indoor environment. In this dissertation, the type and amount of byproducts that result from ozone reactions with common indoor surfaces, surface residues, and vapors were determined, pollutant concentrations were related to occupant exposure, and frameworks were developed to predict byproduct concentrations under various indoor conditions. In Chapter 2, an analysis is presented of secondary organic aerosol formation from the reaction of ozone with gas-phase, terpene-containing consumer products in small chamber experiments under conditions relevant for residential and commercial buildings. The full particle size distribution was continuously monitored, and ultrafine and fine particle concentrations were in the range of 10 to>300 mu g m-3. Particle nucleation and growth dynamics were characterized.Chapter 3 presents an investigation of ozone reactions with aircraft cabin surfaces including carpet, seat fabric, plastics, and laundered and worn clothing fabric. Small chamber experiments were used to determine ozone deposition velocities, ozone reaction probabilities, byproduct emission rates, and byproduct yields for each surface category. The most commonly detected byproducts included C1?C10 saturated aldehydes and skin oil oxidation products. For all materials, emission rates were higher with ozone than without. Experimental results were used to predict byproduct exposure in the cabin and compare to other environments. Byproduct levels are predicted to be similar to ozone levels in the cabin, which have been found to be tens to low hundreds of ppb in the absence of an ozone converter. In Chapter 4, a model is presented that predicts ozone uptake by and byproduct emission from residual chemicals on surfaces. The effects of input parameters (residue surface concentration, ozone concentration, reactivity of the residue and the surface, near-surface airflow conditions, and

  19. Surface ozone exposures measured at clean locations around the world.

    PubMed

    Lefohn, A S; Krupa, S V; Winstanley, D

    1990-01-01

    For assessing the effects of air pollution on vegetation, some researchers have used control chambers as the basis of comparison between crops and trees grown in contemporary polluted rural locations and those grown in a clean environment. There has been some concern whether the arbitrary ozone level of 0.025 ppm and below, often used in charcoal-filtration chambers to simulate the natural background concentration of ozone, is appropriate. Because of the many complex and man-made factors that influence ozone levels, it is difficult to determine natural background. To identify a range of ozone exposures that occur at 'clean' sites, we have calculated ozone exposures observed at a number of 'clean' monitoring sites located in the United States and Canada. We do not claim that these sites are totally free from human influence, but rather than the ozone concentrations observed at these 'clean' sites may be appropriate for use by vegetation researchers in control chambers as pragmatic and defensible surrogates for natural background. For comparison, we have also calculated ozone exposures observed at four 'clean' remote sites in the Northern and Southern Hemispheres and at two remote sites (Whiteface Mountain, NY and Hohenpeissenberg, FRG) that are considered to be more polluted. Exposure indices relevant for describing the relationship between ozone and vegetation effects were applied. For studying the effects of ozone on vegetation, the higher concentrations are of interest. The sigmoidally-weighted index appeared to best separate those sites that experienced frequent high concentration exposures from those that experienced few high concentrations. Although there was a consistent seasonal pattern for the National Oceanic and Atmospheric Administration (NOAA) Geophysical Monitoring for Climate Change (GMCC) sites indicating a winter/spring maximum, this was not the case for the other remote sites. Some sites in the continental United States and southern Canada

  20. Ozone NAAQS Review: Risk/Exposure Assessment

    EPA Science Inventory

    Ozone is one of the six major air pollutants for which EPA has issued air quality criteria and established national ambient air quality standards (NAAQS) based on those criteria. The Clear Air Act (CAA) requires EPA to periodically review and revise, as appropriate, existing air ...

  1. Sudden Gains in Prolonged Exposure and Sertraline for Chronic PTSD

    PubMed Central

    Jun, Janie J.; Zoellner, Lori A.; Feeny, Norah C.

    2014-01-01

    Background Sudden gains are significant, rapid improvements in symptoms, larger than typical between-session symptom reduction.[8] Sudden gains in a large sample of individuals with PTSD have not been studied, and only one study has looked at it in pharmacotherapy, but not in PTSD. In the present study, we examined the occurrence of sudden gains in psychotherapy, specifically prolonged exposure (PE), and pharmacotherapy, specifically sertraline, for chronic PTSD. Method Sudden gains in PTSD symptoms (PTSD Symptom Scale-Self-Report[23]) were assessed in 200 individuals with PTSD during 10 weeks of PE or sertraline. Results Individuals in both PE (42.2%) and sertraline (31%) exhibited sudden gains. Individuals in PE made more gains toward the end of treatment (7.2%) than sertraline (2%, OR = 3.82). However, individuals in sertraline made larger gains during early treatment (M = 18.35, SD = 8.15) than PE (M = 12.53, SD = 5.16, d = .85). Notably, those on sertraline were more likely to exhibit a reversal of sudden gains than those in PE (OR = .23). Pointing to clinical significance, the presence of a sudden gain was associated with better reduction in symptoms from pre- to post-treatment (β = -.49). Conclusions Individuals in both PE and sertraline experienced gains, though sertraline was associated with earlier large but reversible gains, and PE was associated with later gains. This differential pattern of discontinuous change highlights potential differential mechanism for these therapies and marks important transition points for further detailed analyses of change mechanisms. PMID:23633445

  2. THE EFFECT OF CONTROLLED OZONE EXPOSURE ON HUMAN LUMPHOCYTE FUNCTION

    EPA Science Inventory

    The effects of ozone (03) on cell-mediated immunity were studied in 16 human subjects exposed to 1176 micrograms/cu.m. 03 (0.6 ppm) for 2 hr in an environmentally controlled exposure chamber. Venous blood smaples were taken before and immediately after controlled air and 03 expos...

  3. DECREMENTS IN OLFACTORY SENSITIVITY DUE TO OZONE EXPOSURE

    EPA Science Inventory

    Approximate olfactory thresholds were determined in an exploratory study in which subjects were exposed to ozone (O3). The odorants were butyl alcohol (BA) and acetic acid (AA). Preliminary data suggest (1) temporary increases in thresholds due to O3 exposure, (2) diminution of O...

  4. EFFECTS OF EXPOSURE TO OZONE ON SUSCEPTIBILITY TO EXPERIMENTAL TUBERCULOSIS

    EPA Science Inventory

    Exposure of mice to 1.96 mg/cu. m. ozone (03) 3 h/day, 5 days/week, for up to 8 weeks beginning at 1 or 2 weeks after challenge with Mycobacterium tuberculosis R1Rv resulted in significant enhancement of bacterial titers in the lungs at 5 through 8 weeks after challenge when comp...

  5. BIOCHEMICAL CHANGES IN HUMANS UPON EXPOSURE TO OZONE AND EXERCISE

    EPA Science Inventory

    A total of 44 human subjects were exposed to 784 micrograms/cu.m.(0.4 ppm) ozone and 30 human subjects were exposed to air as controls. A four hour exposure was given on each of five consecutive days. Half of each group received a higher level of treadmill exercise than the other...

  6. Competing for Consciousness: Prolonged Mask Exposure Reduces Object Substitution Masking

    ERIC Educational Resources Information Center

    Goodhew, Stephanie C.; Visser, Troy A. W.; Lipp, Ottmar V.; Dux, Paul E.

    2011-01-01

    In object substitution masking (OSM) a sparse, temporally trailing 4-dot mask impairs target identification, even though it has different contours from, and does not spatially overlap with the target. Here, we demonstrate a previously unknown characteristic of OSM: Observers show reduced masking at prolonged (e.g., 640 ms) relative to intermediate…

  7. Ozone’s Impact on Public Health: Contributions from Indoor Exposures to Ozone and Products of Ozone-Initiated Chemistry

    PubMed Central

    Weschler, Charles J.

    2006-01-01

    Objective The associations between ozone concentrations measured outdoors and both morbidity and mortality may be partially due to indoor exposures to ozone and ozone-initiated oxidation products. In this article I examine the contributions of such indoor exposures to overall ozone-related health effects by extensive review of the literature as well as further analyses of published data. Findings Daily inhalation intakes of indoor ozone (micrograms per day) are estimated to be between 25 and 60% of total daily ozone intake. This is especially noteworthy in light of recent work indicating little, if any, threshold for ozone’s impact on mortality. Additionally, the present study estimates that average daily indoor intakes of ozone oxidation products are roughly one-third to twice the indoor inhalation intake of ozone alone. Some of these oxidation products are known or suspected to adversely affect human health (e.g., formaldehyde, acrolein, hydroperoxides, fine and ultrafine particles). Indirect evidence supports connections between morbidity/mortality and exposures to indoor ozone and its oxidation products. For example, cities with stronger associations between outdoor ozone and mortality tend to have residences that are older and less likely to have central air conditioning, which implies greater transport of ozone from outdoors to indoors. Conclusions Indoor exposures to ozone and its oxidation products can be reduced by filtering ozone from ventilation air and limiting the indoor use of products and materials whose emissions react with ozone. Such steps might be especially valuable in schools, hospitals, and childcare centers in regions that routinely experience elevated outdoor ozone concentrations. PMID:17035131

  8. Airway response to ultra short-term exposure to ozone

    SciTech Connect

    Fouke, J.M.; Delemos, R.A.; McFadden, E.R. Jr.

    1988-02-01

    To determine whether acute short-term exposure to oxidant pollutants can cause changes in respiratory mechanics, we gave 0.5 ppm ozone for 5 min to 7 baboons. We measured pulmonary resistance (RL) and obtained dose response curves to methacholine before and after the exposures. This brief insult increased resistance (control RL = 1.53 +/- 0.21 cm H/sub 2/O.L-1 s; post-ozone RL = 3.53 +/- 0.54 cm H/sub 2/O.L-1 s). On a second occasion, 6 of these animals were restudied before and after the administration of cromolyn sodium. Although this drug had no effect on the measurements of mechanics made in the control period, it significantly reduced the ozone-induced changes in mechanics. The increase in RL was 52% of that produced in the first study. The results demonstrated that the ozone injury with its acute and subacute airway sequelae occurs quite rapidly and after very brief exposure. The time course of the change in mechanics and the effects of cromolyn suggest the hypothesis that surface epithelial cells are disrupted, causing subsequent release of bronchoconstricting agents.

  9. Attenuated response to repeated daily ozone exposures in asthmatic subjects

    SciTech Connect

    Gong, H. Jr.; Linn, W.S.; McManus, M.S.

    1997-01-01

    The development of attenuated response ({open_quotes}tolerance{close_quotes}) to daily ozone (O{sub 3}) exposures in the laboratory is well established in healthy adult volunteers. However, the capability of asthmatics to develop tolerance during multiday ozone exposures in unclear. We exposed 10 adult volunteers with mild asthma to 0.4 ppm O{sub 3} in filtered air for 3 h/d on 5 consecutive d. Two similar filtered-air exposures during the preceding week served as controls. Follow-up O{sub 3} exposures were performed 4 and 7 d after the most recent consecutive exposure. All exposures were performed in an environmental chamber at 31 {degrees}C and 35% relative humidity. The subjects performed moderate exercise (mean ventilation rate of 32 l/min) for 15 min of each half-hour. Responses were measured with spirometry and symptom evaluations before and after each exposure, and a bronchial reactivity test (methacholine challenge) was conducted after each exposure. All response measurements showed clinically and statistically significant day-to-day variation. Symptom and forced-expiratory-volume-in-1-s responses were similarly large on the 1st and 2nd O{sub 3} exposure days, after which they diminished progressively, approaching filtered air response levels by the 5th consecutive O{sub 3} day. This tolerance was partially lost 4 and 7 d later. Bronchial reactivity peaked after the first O{sub 3} exposure and remained somewhat elevated after all subsequent O{sub 3} exposures, relative to its control level following filtered-air exposures. Individual responses varied widely; more severe initial responses to O{sub 3} predicted less rapid attenuation. We concluded that asthmatics can develop tolerance to frequent high-level O{sub 3} exposures in much the same manner as normal subjects, although the process may be slower and less fully effective in asthmatics. 27 refs., 3 figs., 4 tabs.

  10. Exposure of humans to ambient levels of ozone for 6. 6 hours causes cellular and biochemical changes in the lung

    SciTech Connect

    Devlin, R.B.; McDonnell, W.F.; Mann, R.; Becker, S.; House, D.E.; Schreinemachers, D.; Koren, H.S. )

    1991-01-01

    An acute (2 h) exposure of humans to 0.4 ppm ozone initiates biochemical changes in the lung that result in the production of components mediating inflammation and acute lung damage as well as components having the potential to lead to long-term effects such as fibrosis. However, many people are exposed to lower levels of ozone than this, but for periods of several hours. Therefore, it is important to determine if a prolonged exposure to low levels of ozone is also capable of causing cellular and biochemical changes in the lung. Nonsmoking males were randomly exposed to filtered air and either 0.10 ppm ozone or 0.08 ppm ozone for 6.6 h with moderate exercise (40 liters/min). Bronchoalveolar lavage (BAL) was performed 18 h after each exposure, and cells and fluid were analyzed. The BAL fluid of volunteers exposed to 0.10 ppm ozone had significant increases in neutrophils (PMNs), protein, prostaglandin E2 (PGE2), fibronectin, interleukin-6 (IL-6), and lactate dehydrogenase (LDH) compared with BAL fluid from the same volunteers exposed to filtered air. In addition, there was a decrease in the ability of alveolar macrophages to phagocytize yeast via the complement receptor. Exposure to 0.08 ppm ozone resulted in significant increases in PMNs, PGE2, LDH, IL-6, alpha 1-antitrypsin, and decreased phagocytosis via the complement receptor. However, BAL fluid protein and fibronectin were no longer significantly elevated. We conclude that exposure of humans to as low a level as 0.08 ppm for 6.6 h is sufficient to initiate an inflammatory reaction in the lung.

  11. PULMONARY FUNCTION AND SYMPTOM RESPONSES AFTER 6.6-HOUR EXPOSURE TO 0.12 PPM OZONE WITH MODERATE EXERCISE (JOURNAL VERSION)

    EPA Science Inventory

    Episodes occasionally occur when ambient ozone (03) levels remain at or near 0.12 ppm for more than 6 h. The hypothesis that prolonged exposure to 0.12 ppm 03 would result in progressively larger changes in respiratory function and symptoms over time was tested. Ten nonsmoking ma...

  12. Canine ovarian fibroma associated with prolonged exposure to mibolerone.

    PubMed

    Seaman, W J

    1985-01-01

    A study to determine the efficacy and safety of mibolerone following prolonged oral administration in the female dog was terminated after 9.6 yr. Histopathologic examination revealed the presence of small dense tumors in the ovaries of 12 of 92 dogs given mibolerone at the approximate efficacious dose. No such tumors were found in 60 vehicle control animals or 55 animals given exaggerated doses of mibolerone. The tumors were composed of dense fibrous connective tissue and incorporated occasional ovarian medullary tubules. The tumors appeared to grow by expansion with no evidence of invasion or metastasis and were diagnosed as fibromas. PMID:4070927

  13. Ozone exposure assessment in a southern California community.

    PubMed Central

    Liu, L J; Delfino, R; Koutrakis, P

    1997-01-01

    An ozone exposure assessment study was conducted in a Southern California community. The Harvard ozone passive sampler was used to monitor cohorts of 22 and 18 subjects for 8 weeks during the spring and fall of 1994, respectively. Ozone exposure variables included 12-hr personal O3 measurements, stationary outdoor O3 measurements from a continuous UV photometer and from 12-hr Harvard active monitors, and time-activity information. Results showed that personal O3 exposure levels averaged one-fourth of outdoor stationary O3 levels, attributable to high percentages of time spent indoors. Personal O3 levels were not predicted well by outdoor measurements. A random-effect general linear model analysis indicated that variance in personal exposure measurements was largely accounted for by random error (59-82%), followed by inter-subject (9-18%) and between-day (9-23%) random effects. The microenvironmental model performs differently by season, with the regression model for spring cohorts exhibiting two times the R2 of the fall cohorts (R2 = 0.21 vs. 0.09). When distance from the stationary monitoring site, elevation, and traffic are taken into account in the microenvironmental models, the adjusted R2 increased almost twofold for the fall personal exposure data. The low predictive power is due primarily to the apparent spatial variation of outdoor O3 and errors in O3 measurements and in time-activity records (particularly in recording the use of air conditioning). This study highlights the magnitude of O3 exposure misclassification in epidemiological settings and proposes an approach to reduce exposure uncertainties in assessing air pollution health effects. Images Figure 1. A Figure 1. B Figure 2. A Figure 2. B Figure 3. Figure 4. Figure 5. Figure 6. PMID:9074882

  14. Chronic exposure to ozone causes restrictive lung disease

    SciTech Connect

    Grose, E.C.; Costa, D.L.; Hatch, G.E.; Miller, F.J.; Graham, J.A.

    1989-01-01

    A chronic study to determine the progression and/or reversibility of ozone-induced lung disease was conducted. Male rats were exposed to a diurnal pattern of ozone (O{sub 3}) for 1 week, 3 weeks, 3 months, 12 months, or 18 months. The occurrence of chronic lung disease was determined by structural and functional endpoints. Structurally, a biphasic response was observed with an initial acute inflammatory response after 1 week of exposure, a reduced acute response after 3 weeks of exposure, and an epithelial and interstitial response observed after 3 months which persisted or increased in intensity up to 18 months of exposure. Functional studies showed a persistence of decreased total lung capacity and residual volumes at 3, 12, and 18 months of exposure, a response indicative of restrictive lung disease. Biochemical changes in antioxidant metabolism were also observed after 12 and 18 months of exposure. Most significant changes were resolved after the clean-air recovery period. The study has shown that chronic exposure to O{sub 3} causes restrictive lung disease as characterized by the development of focal interstitial fibrosis.

  15. PLASMA AND LUNG MACROPHAGE CAROTENOID RESPONSIVENESS TO SUPPLEMENTATION AND OZONE EXPOSURE IN HUMANS

    EPA Science Inventory

    OBJECTIVE:: To examine the effect of ozone exposure and vegetable juice supplementation on plasma and lung macrophage concentrations of carotenoids. DESIGN:: A randomized trial. SETTING:: Subjects were exposed to ambient air prior to antioxidant supplementation and to ozone after...

  16. Prolonged in vitro exposure of Staphylococcus aureus to germicidal teat dips.

    PubMed

    Hogan, J S; Smith, K L

    1989-04-01

    Eight strains of Staphylococcus aureus were tested to determine if prolonged exposure to commercial teat dips could enhance bacterial tolerance to teat dips in vitro. All strains of S. aureus were serially plated 15 times on chemically defined agar medium containing sublethal concentrations of linear dodecyl benzene sulfonic acid, chlorhexidine, sodium hypochlorite, and iodophor teat dips. Growth responses of S. aureus to chlorhexidine, sodium hypochlorite, and iodophor were not affected by prolonged exposure to these teat dips. Isolates subcultured on agar containing .1% linear dodecyl benzene sulfonic acid teat dip subsequently had a greater mean growth response to .1% solution of the germicide than did controls subcultured on basal medium. Hemolytic patterns, tube coagulase, clumping factor, and protein A reactions of S. aureus were not altered by exposure to any of the teat dips tested. In general, prolonged exposure to commercial teat dips did not alter germicidal susceptibility of S. aureus. PMID:2745808

  17. Effect of prolonged exposure to organic solvents on the active site environment of subtilisin Carlsberg

    PubMed Central

    Bansal, Vibha; Delgado, Yamixa; Fasoli, Ezio; Ferrer, Amaris; Griebenow, Kai; Secundo, Francesco; Barletta, Gabriel L

    2010-01-01

    The potential of enzyme catalysis as a tool for organic synthesis is nowadays indisputable, as is the fact that organic solvents affect an enzyme’s activity, selectivity and stability. Moreover, it was recently realized that an enzyme’s initial activity is substantially decreased after prolonged exposure to organic media, an effect that further hampers their potential as catalysts for organic synthesis. Regrettably, the mechanistic reasons for these effects are still debatable. In the present study we have made an attempt to explain the reasons behind the partial loss of enzyme activity on prolonged exposure to organic solvents. Fluorescence spectroscopic studies of the serine protease subtilisin Carlsberg chemically modified with polyethylene glycol (PEG-SC) and inhibited with a Dancyl fluorophore, and dissolved in two organic solvents (acetonitrile and 1,4-dioxane) indicate that when the enzyme is initially introduced into these solvents, the active site environment is similar to that in water; however prolonged exposure to the organic medium causes this environment to resemble that of the solvent in which the enzyme is dissolved. Furthermore, kinetic studies show a reduction on both Vmax and KM as a result of prolonged exposure to the solvents. One interpretation of these results is that during this prolonged exposure to organic solvents the active-site fluorescent label inhibitor adopts a different binding conformation. Extrapolating this to an enzymatic reaction we argue that substrates bind in a less catalytically favorable conformation after the enzyme has been exposed to organic media for several hours. PMID:20414456

  18. Response of the rat erythrocyte to ozone exposure

    NASA Technical Reports Server (NTRS)

    Larkin, E. C.; Kimzey, S. L.; Siler, K.

    1978-01-01

    Sprague-Dawley rats were exposed to high (6-8 ppm) and moderate (1.5 ppm) amounts of ozone (O3) for various time periods. Response of the rat erythrocyte to ozone was monitored with red blood cell potassium (rubidium) influx studies, with storage stress combined with ultrastructural studies and with levels of erythrocyte glutathione peroxidase and superoxide dismutase. Erythrocytes of rats exposed to O3 showed no significant changes either in their potassium influx or in their glutathione peroxidase and superoxide dismutase activities compared to controls. Erythrocyte differential counts on O3-exposed animals showed significant changes initially as well as following storage stress compared to controls. Rats exposed to 8 ppm O3 for 4 h showed a marked increase in echinocytes. These consistent transformations from discocytes to echinocytes following O3 exposure suggest latent erythrocyte damage has occurred.

  19. Exposure of human lung fibroblasts to ozone: cell mortality and hyaluronan metabolism

    SciTech Connect

    Mayer, D.; Branscheid, D. )

    1992-04-01

    Exposure of cultures of human lung fibroblasts to 0.5 ppm ozone for 20 h resulted in a significant increase in cellular mortality by 29%; after exposure to 2.5 ppm ozone for 4 h, the increase amounted to 74%. A marked difference in sensitivity to ozone was observed between fibroblast lines from different individuals. This variability in resistance to ozone was more evident after exposure to 0.5 ppm ozone for 20 h, when compared with 2.5 ppm ozone for 4 h. In one fibroblast line, synthesis of hyaluronan was enhanced by exposure to 0.5 ppm ozone for 20 h. The concentrations of hyaluronan in culture media increased in experiments using different fibroblast cell lines, a phenomenon that was obvious both if cell numbers and combined protein concentrations of cells and media are selected as references for hyaluronan concentrations.

  20. USE OF AUXILIARY DATA FOR SPATIAL INTERPOLATION OF OZONE EXPOSURE IN SOUTHEASTERN FORESTS

    EPA Science Inventory

    In order to assess the impact of tropospheric ozone on forests, it is necessary to quantify ozone exposure on regional scales. Since ozone monitoring stations are widely scattered and mostly concentrate in urban and suburban areas, some form of spatial interpolation is necessary ...

  1. Ozone Exposure System Designed and Used to High-Altitude Airship Materials

    NASA Technical Reports Server (NTRS)

    Miller, Sharon K.

    2005-01-01

    High-altitude airships can receive high doses of ozone over short mission durations. For example, in 1 year at an altitude of 70,000 ft, the ozone fluence (number arriving per unit area) can be as high as 1.2 1024 molecules/sq cm. Ozone exposure at these levels can embrittle materials or change the performance of solar cells. It is important to expose components and materials to the expected ozone dosage to determine if the ozone exposure could cause any mission-critical failures.

  2. Ozone decreases spring root growth and root carbohydrate content in ponderosa pine the year following exposure

    SciTech Connect

    Andersen, C.P.; Hogsett, W.E.; Wessling, R.; Plocher, M.

    1991-01-01

    Storage carbohydrates are extremely important for new shoot and root development following dormancy or during periods of high stress. The hypothesis that ozone decreases carbohydrate storage and decreases new root growth during the year following exposure was investigated. The results suggest that (1) ponderosa pine seedlings exposed to 122 and 169 ppm hrs ozone for one season have significantly less root starch reserves available just prior to and during bud break the following year, and (2) spring root growth is decreased following ozone exposure. The carry-over effects of ozone stress may be important in long-lived perennial species which are annually subjected to ozone.

  3. Adaptive response of poplar (Populus nigra L.) after prolonged Cd exposure period.

    PubMed

    Jakovljević, Tamara; Bubalo, Marina Cvjetko; Orlović, Sanja; Sedak, Marija; Bilandžić, Nina; Brozinčević, Iva; Redovniković, Ivana Radojčić

    2014-03-01

    An outdoor pot experiment was designed to study the changes of growth parameters, accumulation, and distribution of Cd in poplar (Populus nigra L.) during a prolonged exposure period (growing period of 17 months including three harvest points), allowing the consideration of time effects and prolonged adaptation to Cd stress. Simultaneously, changes to the antioxidant system in roots and leaves were monitored. It was demonstrated that poplar could adapt to the Cd-contaminated soils after prolonged exposure. Total Cd accumulation in the aerial parts of poplar, due to high biomass production and acceptable Cd accumulation parameters, implies that the tested poplar species could be a good candidate for Cd phytoextraction application as well as could be used as phytostabilizer of Cd in heavily polluted soil. Furthermore, the activity of the antioxidant machinery displays both a tissue- and exposure-specific response pattern to different Cd treatments, indicating that strict regulation of the antioxidant defense system is required for the adaptive response of poplar. In addition, this report highlights the importance of prolonged exposure studies of physiological responses of plants, especially for long-life-cycle woody species under heavy metal stress, since some misleading conclusions could be reached after shorter time periods. PMID:24288057

  4. Prolonged Exposure versus Dynamic Therapy for Adolescent PTSD: A Pilot Randomized Controlled Trial

    ERIC Educational Resources Information Center

    Gilboa-Schechtman, Eva; Foa, Edna B.; Shafran, Naama; Aderka, Idan M.; Powers, Mark B.; Rachamim, Lilach; Rosenbach, Lea; Yadin, Elna; Apter, Alan

    2010-01-01

    Objective: To examine the efficacy and maintenance of developmentally adapted prolonged exposure therapy for adolescents (PE-A) compared with active control time-limited dynamic therapy (TLDP-A) for decreasing posttraumatic and depressive symptoms in adolescent victims of single-event traumas. Method: Thirty-eight adolescents (12 to 18 years old)…

  5. Prolonged Exposure Therapy for a Vietnam Veteran with PTSD and Early-Stage Dementia

    ERIC Educational Resources Information Center

    Duax, Jeanne M.; Waldron-Perrine, Brigid; Rauch, Sheila A. M.; Adams, Kenneth M.

    2013-01-01

    Although prolonged exposure therapy (PE) is considered an evidence-based treatment for PTSD, there has been little published about the use of this treatment for older adults with comorbid early-stage dementia. As the number of older adults in the United States continues to grow, so will their unique mental health needs. The present article…

  6. Direction of Influence between Posttraumatic and Depressive Symptoms during Prolonged Exposure Therapy among Children and Adolescents

    ERIC Educational Resources Information Center

    Aderka, Idan M.; Foa, Edna B.; Applebaum, Edna; Shafran, Naama; Gilboa-Schechtman, Eva

    2011-01-01

    Objective: Our objective in the present study was to examine the temporal sequencing of posttraumatic and depressive symptoms during prolonged exposure therapy for posttraumatic stress disorder (PTSD) among children and adolescents. Method: Participants were 73 children and adolescents (56.2% female) between the ages of 8 and 18. Participants…

  7. Prolonged Exposure Treatment of Chronic PTSD in Juvenile Sex Offenders: Promising Results from Two Case Studies

    ERIC Educational Resources Information Center

    Hunter, John A.

    2010-01-01

    Prolonged exposure (PE) was used to treat chronic PTSD secondary to severe developmental trauma in two adolescent male sex offenders referred for residential sex offender treatment. Both youth were treatment resistant prior to initiation of PE and showed evidence of long-standing irritability and depression/anxiety. Clinical observation and…

  8. Prolonged Duration and Frequency of Springtime Ozone Depletion Events in the Arctic

    NASA Astrophysics Data System (ADS)

    McClure-Begley, A.; Petropavlovskikh, I. V.; Oltmans, S. J.; Uttal, T.; Crepinsek, S.

    2013-12-01

    Surface ozone measurements have been maintained in Barrow, Alaska since the mid-1970's, this long term data set allows for analysis and research regarding the year to year variability and long term trends of tropospheric ozone in this region. Since the discovery of ozone depletion events (ODE's) in the 1980's [Oltmans , 1981] evidence has shown that there is a direct correlation between sea ice age, wind direction, and ozone depletions. As the climate continues to change, the characteristics and chemistry of the sea ice, and in turn atmosphere, will change as well. With first year sea ice now making up the majority of Arctic ice cover, younger and saltier ice is being melted each spring. Bromine and other halogens are released into the atmosphere from brine depositions on the ice surface resulting in photo chemical reactions depleting ozone at the surface. It must be considered that wind direction of air masses moving into the measurement location play a great role on the intensity and frequency of events each year. When air masses have dominant land based direction, then the depletion events are not seen. These ODE's have been steadily increasing over time, with a remarkable amount of depletion detected in 2012. Data collected from Thermo Scientific Model 49c Ozone monitors in Barrow, Alaska and Tiksi, Russia (located at 71.6 N and 71.3 N respectively to minimize solar angle differences) can be correlated with dominant wind direction, Hybrid Single Particle Langrangian Integrated Trajectory (HYSPLIT) modeling, and ice age to form an association between ODE's and winds passing over the halogen rich arctic ice. 2013 data from both arctic locations is analyzed to determine the dynamics of ozone depletions with regard to changing ice conditions and wind patterns as compared to 2012 and historical data. The data must be scrutinized with regard to the confounding variables to determine the mechanism behind the extended duration and severity of depletion events in the

  9. Examining acute health outcomes due to ozone exposure and their subsequent relationship to chronic disease outcomes

    SciTech Connect

    Ostro, B.D.

    1993-12-01

    Current evidence indicates that individuals exposed to short term elevations in ambient ozone may experience both upper and lower respiratory effects. Some respiratory symptoms and spirometric changes are mild and reversible in nature, while others involve more severe outcomes, including hospital admissions and emergency room visits. However, many questions remain about the effects of acute ozone exposure and the implications of this exposure for chronic disease outcomes. For example, the identification of sensitive subgroups, the delineation of the entire spectrum of health effects due to exposure to ozone, the potential synergy between viral infections and ozone exposure, and the nature of adaptation to ozone are not well characterized. In addition, studies that examine the association between acute responses to ozone and potential biological indicators of a chronic disease process would be desirable. This paper serves to provide an overview of the types of epidemiologic studies that may be appropriate and factors to consider in addressing these questions. 23 refs.

  10. Effects of varying environmental conditions on vegetation response to ozone exposure

    SciTech Connect

    Zaleski, R.T.; Triemer, L.R.

    1995-12-31

    Developing an exposure-effects model for plant response to ozone exposure is a complex process. It is known that ozone must enter the plant through the stomata for an effect to occur. Therefore, ozone uptake is related not only to ambient ozone concentrations, but also to environmental factors which control stomatal movement. In addition, cellular factors within the plant can mitigate ozone impact and ultimately control plant response. This paper presents a review of the scientific literature on plant responses (e.g. visible foliar injury, reductions in growth or yield) to ozone exposures under varying environmental conditions known to affect stomatal aperture. The results of this effort show the importance of considering key environmental factors when developing exposure-effects models.

  11. TOWARDS RELIABLE AND COST-EFFECTIVE OZONE EXPOSURE ASSESSMENT: PARAMETER EVALUATION AND MODEL VALIDATION USING THE HARVARD SOUTHERN CALIFORNIA CHRONIC OZONE EXPOSURE STUDY DATA

    EPA Science Inventory

    Accurate assessment of chronic human exposure to atmospheric criteria pollutants, such as ozone, is critical for understanding human health risks associated with living in environments with elevated ambient pollutant concentrations. In this study, we analyzed a data set from a...

  12. ZINC-DEFICIENCY ENHANCES PRO-INFLAMMATORY RESPONSES AFTER OZONE EXPOSURE

    EPA Science Inventory

    Epidemiological and controlled exposure studies have demonstrated that humans are differentially susceptible to adverse health effects induced by exposure to ozone. Serum analysis of vitamins and trace elements have shown that the elderly (people >65 years) are deficient in sever...

  13. PROPORTION OF MODERATELY EXERCISING INDIVIDUALS RESPONDING TO LOW-LEVEL, MULTI-HOUR OZONE EXPOSURE

    EPA Science Inventory

    The purpose of this study was to describe the proportion of moderately exercising individuals experiencing significant respiratory responses to low-level, multi-hour ozone exposure as a function of ozone concentration and exposure duration. ixty-eight healthy, nonsmoking adults, ...

  14. OZONE-INDUCED RESPIRATORY SYMPTOMS AND LUNG FUNCTION DECREMENTS IN HUMANS: EXPOSURE-RESPONSE MODELS

    EPA Science Inventory

    Short duration exposure to ozone (<8 hr) is known to result in lung function decrements and respiratory symptoms in humans. The magnitudes of these responses are functions of ozone concentration (C), activity level measured by minute ventilation (Ve), duration of exposure (T), a...

  15. DURATION OF INCREASED PULMONARY FUNCTION SENSITIVITY TO AN INITIAL OZONE EXPOSURE

    EPA Science Inventory

    The metabolic and pulmonary function effects were investigated in 6 non-smoking, young adults who were exposed for 2 hours (22 deg. WBGT) to: (1) Filtered air (FA), (2) 0.45 ppm ozone (DAY), and (3) Two days later to a second exposure to 0.45 ppm ozone exposure (DAY2). The subjec...

  16. A DYNAMIC NONLINEAR MODEL OF OZONE-INDUCED FEV1 RESPONSE UNDER CHANGING EXPOSURE CONDITIONS

    EPA Science Inventory

    A Dynamic Nonlinear Model of Ozone-induced FEV1 Response under Changing Exposure Conditions. 1WF McDonnell, 2PW Stewart, 3MV Smith. 1Human Studies Division, NHEERL, U.S. EPA, RTP, NC. 2University of North Carolina, Chapel Hill, NC. 3ASI, Durham, NC.

    Ozone exposure result...

  17. Determination of oxidant exposure during ozonation of secondary effluent to predict contaminant removal.

    PubMed

    Zucker, Ines; Avisar, Dror; Mamane, Hadas; Jekel, Martin; Hübner, Uwe

    2016-09-01

    The use of kinetic models to predict oxidation performance in wastewater is limited due to fast ozone depletion during the first milliseconds of the reaction. This paper introduces the Quench Flow Module (QFM), a bench-scale experimental technique developed to measure the first 5-500 milliseconds of ozone depletion for accurate determination of ozone exposure in wastewater-ozonation processes. Calculated ozone exposure in QFM experiments was up to 24% lower than in standard batch experiments, strongly depending on the initial sampling point for measurement in batch experiments. However, oxidation rates of slowly- and moderately-reacting trace organic compounds (TrOCs) were accurately predicted from batch experiments based on integration of ozone depletion and removal of an ozone-resistant probe compound to calculate oxidant exposures. An alternative concept, where ozone and hydroxyl radical exposures are back-calculated from the removal of two probe compounds, was tested as well. Although the QFM was suggested to be an efficient mixing reactor, ozone exposure ranged over three orders of magnitude when different probe compounds reacting moderately with ozone were used for the calculation. These effects were beyond uncertainty ranges for apparent second order rate constants and consistently observed with different ozone-injection techniques, i.e. QFM, batch experiments, bubble columns and venturi injection. This indicates that previously suggested mixing effects are not responsible for the difference and other still unknown factors might be relevant. Results furthermore suggest that ozone exposure calculations from the relative residual concentration of a probe compound are not a promising option for evaluation of ozonation of secondary effluents. PMID:27232995

  18. Physiological Stress Responses to Prolonged Exposure to MS-222 and Surgical Implantation in Juvenile Chinook Salmon

    SciTech Connect

    Wagner, Katie A.; Woodley, Christa M.; Seaburg, Adam; Skalski, John R.; Eppard, Matthew B.

    2014-07-17

    While many studies have investigated the effects of transmitters on fish condition, behavior, and survival, to our knowledge, no studies have taken into account anesthetic exposure time in addition to tag and surgery effects. We investigated stress responses to prolonged MS-222 exposure after stage 4 induction in surgically implanted juvenile Chinook salmon (Oncorhynchus tshawytscha). Survival, tag loss, plasma cortisol concentration, and blood Na+, K+, Ca2+, and pH were measured immediately following anesthetic exposure and surgical implantation and 1, 7, and 14 days post-treatment. Despite the prolonged anesthetic exposure, 3-15 minutes post Stage 4 induction, there were no mortalities or tag loss in any treatment. MS-222 was effective at delaying immediate cortisol release during surgical implantation; however, osmotic disturbances resulted, which were more pronounced in longer anesthetic time exposures. From day 1 to day 14, Na+, Ca2+, and pH significantly decreased, while cortisol significantly increased. The cortisol increase was exacerbated by surgical implantation. There was a significant interaction between MS-222 time exposure and observation day for Na+, Ca2+, K+, and pH; variations were seen in the longer time exposures, although not consistently. In conclusion, stress response patterns suggest stress associated with surgical implantation is amplified with increased exposure to MS-222.

  19. Effects of prolonged alcohol exposure on somatotrophs and corticotrophs in adult rats: Stereological and hormonal study.

    PubMed

    Trifunović, Svetlana; Manojlović-Stojanoski, Milica; Ristić, Nataša; Jurijević, Branka Šošić; Balind, Snežana Raus; Brajković, Gordana; Perčinić-Popovska, Florina; Milošević, Verica

    2016-05-01

    Exposure to alcohol alters many physiological processes, including endocrine status. The present study examined whether prolonged alcohol (A) exposure could modulate selected stereological and hormonal aspects of pituitary somatotrophs (growth hormone-GH cells) and corticotrophs (adrenocorticotropic hormone-ACTH cells) in adult rats. Changes in pituitary gland volume; the volume density, total number and volume of GH and ACTH cells following alcohol exposure were evaluated using a stereological system (newCAST), while peripheral GH and ACTH levels were determined biochemically. Our results demonstrated the reduction (p<0.05) of the volume density (37%) and volume of GH cells (29%) in the group A. Also, there was a tendency for the total number of GH cells to be smaller in the group A. Serum GH level was significantly decreased (p<0.05; 70%) in the group A when compared to control values. Moreover, prolonged alcohol exposure induced declines (p<0.05) in volume density (24%) and volume of ACTH cells (29%). The total number of ACTH cells and ACTH level were higher (p<0.05; 42%) in the group A than in control rats. Collectively, these results indicate that prolonged alcohol exposure leads not only to changes in GH and ACTH hormone levels, but also to alterations of the morphological aspects of GH and ACTH cells within the pituitary. PMID:27017477

  20. An evaluation of ozone exposure metrics for a seasonally drought-stressed ponderosa pine ecosystem.

    PubMed

    Panek, Jeanne A; Kurpius, Meredith R; Goldstein, Allen H

    2002-01-01

    Ozone stress has become an increasingly significant factor in cases of forest decline reported throughout the world. Current metrics to estimate ozone exposure for forest trees are derived from atmospheric concentrations and assume that the forest is physiologically active at all times of the growing season. This may be inaccurate in regions with a Mediterranean climate, such as California and the Pacific Northwest, where peak physiological activity occurs early in the season to take advantage of high soil moisture and does not correspond to peak ozone concentrations. It may also misrepresent ecosystems experiencing non-average climate conditions such as drought years. We compared direct measurements of ozone flux into a ponderosa pine canopy with a suite of the most common ozone exposure metrics to determine which best correlated with actual ozone uptake by the forest. Of the metrics we assessed, SUM0 (the sum of all daytime ozone concentrations > 0) best corresponded to ozone uptake by ponderosa pine, however the correlation was only strong at times when the stomata were unconstrained by site moisture conditions. In the early growing season (May and June). SUM0 was an adequate metric for forest ozone exposure. Later in the season, when stomatal conductance was limited by drought. SUM0 overestimated ozone uptake. A better metric for seasonally drought-stressed forests would be one that incorporates forest physiological activity, either through mechanistic modeling, by weighting ozone concentrations by stomatal conductance, or by weighting concentrations by site moisture conditions. PMID:11843543

  1. Prolonged Particulate Hexavalent Chromium Exposure Suppresses Homologous Recombination Repair in Human Lung Cells.

    PubMed

    Browning, Cynthia L; Qin, Qin; Kelly, Deborah F; Prakash, Rohit; Vanoli, Fabio; Jasin, Maria; Wise, John Pierce

    2016-09-01

    Genomic instability is one of the primary models of carcinogenesis and a feature of almost all cancers. Homologous recombination (HR) repair protects against genomic instability by maintaining high genomic fidelity during the repair of DNA double strand breaks. The defining step of HR repair is the formation of the Rad51 nucleofilament, which facilitates the search for a homologous sequence and invasion of the template DNA strand. Particulate hexavalent chromium (Cr(VI)), a human lung carcinogen, induces DNA double strand breaks and chromosome instability. Since the loss of HR repair increases Cr(VI)-induced chromosome instability, we investigated the effect of extended Cr(VI) exposure on HR repair. We show acute (24 h) Cr(VI) exposure induces a normal HR repair response. In contrast, prolonged (120 h) exposure to particulate Cr(VI) inhibited HR repair and Rad51 nucleofilament formation. Prolonged Cr(VI) exposure had a profound effect on Rad51, evidenced by reduced protein levels and Rad51 mislocalization to the cytoplasm. The response of proteins involved in Rad51 nuclear import and nucleofilament formation displayed varying responses to prolonged Cr(VI) exposure. BRCA2 formed nuclear foci after prolonged Cr(VI) exposure, while Rad51C foci formation was suppressed. These results suggest that particulate Cr(VI), a major chemical carcinogen, inhibits HR repair by targeting Rad51, causing DNA double strand breaks to be repaired by a low fidelity, Rad51-independent repair pathway. These results further enhance our understanding of the underlying mechanism of Cr(VI)-induced chromosome instability and thus, carcinogenesis. PMID:27449664

  2. The Harvard Southern California Chronic Ozone Exposure Study: assessing ozone exposure of grade-school-age children in two Southern California communities.

    PubMed Central

    Geyh, A S; Xue, J; Ozkaynak, H; Spengler, J D

    2000-01-01

    The Harvard Southern California Chronic Ozone Exposure Study measured personal exposure to, and indoor and outdoor ozone concentrations of, approximately 200 elementary school children 6-12 years of age for 12 months (June 1995-May 1996). We selected two Southern California communities, Upland and several towns located in the San Bernardino mountains, because certain characteristics of those communities were believed to affect personal exposures. On 6 consecutive days during each study month, participant homes were monitored for indoor and outdoor ozone concentrations, and participating children wore a small passive ozone sampler to measure personal exposure. During each sampling period, the children recorded time-location-activity information in a diary. Ambient ozone concentration data were obtained from air quality monitoring stations in the study areas. We present ozone concentration data for the ozone season (June-September 1995 and May 1996) and the nonozone season (October 1995-April 1996). During the ozone season, outdoor and indoor concentrations and personal exposure averaged 48.2, 11.8, and 18.8 ppb in Upland and 60.1, 21.4, and 25.4 ppb in the mountain towns, respectively. During the nonozone season, outdoor and indoor concentrations and personal exposure averaged 21.1, 3.2, and 6.2 ppb in Upland, and 35.7, 2.8, and 5.7 ppb in the mountain towns, respectively. Personal exposure differed by community and sex, but not by age group. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:10706534

  3. Effect of short-term ozone exposure on exogenous thyroxine levels in thyroidectomized and hypophysectomized rats

    SciTech Connect

    Clemons, G.K.; Wei, D.

    1984-06-15

    Short-term ozone exposure (1 ppm X 24 hr) of male rats results in a significant reduction of circulating thyroid hormones and thyroid stimulating hormone (TSH). The reduction of thyroid hormone levels after ozone exposure has been hypothesized as a possible adaptive mechanism to enhance survival of rats during ozone exposure. In this study, the authors investigated the effect of ozone on thyroid hormone (T4) levels in thyroidectomized and hypophysectomized rats which received exogenous T4 in the drinking water. Groups of normal, intact rats, thyroidectomized rats maintained on T4 at doses ranging from 75 to 1000 micrograms/liter, and hypophysectomized rats maintained on 300 micrograms T4/liter were exposed to ozone (1 ppm X 24 hr), Plasma T4 concentrations were significantly reduced after ozone exposure, and the results indicated that the higher the circulating T4 levels before exposure the more they were reduced after ozone exposure. This reduction in T4 levels cannot be accounted for in these animals by reduced pituitary TSH levels or the effects of fasting, but is likely to be due to peripheral changes in plasma thyroid binding proteins initiated by ozone exposure.

  4. Effect of controlled ozone exposure on human lymphocyte function

    SciTech Connect

    Peterson, M.L.; Smialowicz, R.; Harder, S.; Ketcham, B.; House, D.

    1981-04-01

    The effects of ozone (O/sub 3/) on cell-mediated immunity were studied in 16 human subjects exposed to 1176 ..mu..g/m/sup 3/ O/sub 3/ (0.6 ppM) for 2 h in an environmentally controlled exposure chamber. Venous blood samples were taken before and immediately after controlled air and O/sub 3/ exposures, as well as at 72 h, 2 and 4 weeks, and at one random time at least 1 month after treatment. The relative frequency of T lymphocytes in blood and the in vitro blastogenic response of lymphocytes to phytohemagglutinin (PHA), concanavalin A (Con A), pokeweed mitogen (PWM), and Candida albicans were determined. During the course of the experiment, no statistically significant changes were observed in the number of T lymphocytes that form spontaneous rosettes with sheep erythrocytes. The response of T lymphocytes to PHA was significantly reduced (P < 0.05) in samples taken at 2 and 4 weeks, following O/sub 3/ exposure. Normal response to PHA was observed at 2 months post-O/sub 3/ exposure. No statistically significant changes in lymphocyte responses to Con A, PWM, or Candida were seen. These results show that one 2 h exposure of humans to 0.6 ppM O/sub 3/ may lead to a transient suppression of the PHA-stimulated blastogenic transformation of peripheral blood lymphocytes. The data indicate that the blastogenic response to PHA of human lymphocytes is exquisitely sensitive to O/sub 3/ exposure and could serve as a bioassay for evaluating subtle changes in cellular immunity induced by O/sub 3/ and possibly other pollutants.

  5. Chlorophyll fluorescence quenching during ozone exposure of leaves of Phaseolus vulgaris (pinto)

    SciTech Connect

    Guralnick, L.J. ); Miller, R.; Heath, R.L. )

    1990-05-01

    During ozone exposure, observations have noted an initial decrease in CO{sub 2} uptake followed by a decrease in stomatal conductance. We examined this response utilizing the technique of fluorescence quenching. Fourteen day old plants were exposed to 0.3 ul/l ozone for 1 hour. Fluorescence quenching was monitored using the Hanstech modulated fluorescence system. This enabled us to measure changes in photochemical quenching (qQ) and non-photochemical quenching (qE) in control and ozone treated plants. Results have indicated no differences in qQ and qE between ozone treated and control plants. We are initiating further studies utilizing different ozone levels.

  6. Topoisomerase I inhibitors: the relevance of prolonged exposure for present clinical development.

    PubMed Central

    Gerrits, C. J.; de Jonge, M. J.; Schellens, J. H.; Stoter, G.; Verweij, J.

    1997-01-01

    Topoisomerase I inhibitors constitute a new class of anti-cancer agents. Recently, topotecan and irinotecan were registered for clinical use in ovarian cancer and colorectal cancer respectively. Cytotoxicity of topoisomerase I inhibitors is S-phase specific, and in vitro and in vivo studies have suggested that, for efficacy, prolonged exposure might be more important than short-term exposure to high concentration. Clinical development of those topoisomerase I inhibitors that have reached this stage is also focused on schedules aiming to achieve prolonged exposure. In this review, we summarize all published preclinical studies on this topic for topoisomerase I inhibitors in clinical development, namely 20-S-camptothecin, 9-nitro-camptothecin, 9-amino-camptothecin, topotecan, irinotecan and GI147211. In addition, preliminary data on clinical studies concerning this topic are also reviewed. The data suggest that prolonged exposure may indeed be relevant for anti-tumour activity. However, the optimal schedule is yet to be determined. Finally, clinical data are yet too immature to draw definitive conclusions. PMID:9328159

  7. Systemic metabolic derangement, pulmonary effects, and insulin insufficiency following subchronic ozone exposure in rats.

    PubMed

    Miller, Desinia B; Snow, Samantha J; Henriquez, Andres; Schladweiler, Mette C; Ledbetter, Allen D; Richards, Judy E; Andrews, Debora L; Kodavanti, Urmila P

    2016-09-01

    Acute ozone exposure induces a classical stress response with elevated circulating stress hormones along with changes in glucose, protein and lipid metabolism in rats, with similar alterations in ozone-exposed humans. These stress-mediated changes over time have been linked to insulin resistance. We hypothesized that acute ozone-induced stress response and metabolic impairment would persist during subchronic episodic exposure and induce peripheral insulin resistance. Male Wistar Kyoto rats were exposed to air or 0.25ppm or 1.00ppm ozone, 5h/day, 3 consecutive days/week (wk) for 13wks. Pulmonary, metabolic, insulin signaling and stress endpoints were determined immediately after 13wk or following a 1wk recovery period (13wk+1wk recovery). We show that episodic ozone exposure is associated with persistent pulmonary injury and inflammation, fasting hyperglycemia, glucose intolerance, as well as, elevated circulating adrenaline and cholesterol when measured at 13wk, however, these responses were largely reversible following a 1wk recovery. Moreover, the increases noted acutely after ozone exposure in non-esterified fatty acids and branched chain amino acid levels were not apparent following a subchronic exposure. Neither peripheral or tissue specific insulin resistance nor increased hepatic gluconeogenesis were present after subchronic ozone exposure. Instead, long-term ozone exposure lowered circulating insulin and severely impaired glucose-stimulated beta-cell insulin secretion. Thus, our findings in young-adult rats provide potential insights into epidemiological studies that show a positive association between ozone exposures and type 1 diabetes. Ozone-induced beta-cell dysfunction may secondarily contribute to other tissue-specific metabolic alterations following chronic exposure due to impaired regulation of glucose, lipid, and protein metabolism. PMID:27368153

  8. Use of AIRS, OMI, MLS, and TES Data in Assessing Forest Ecosystem Exposure to Ozone

    NASA Technical Reports Server (NTRS)

    Spruce, Joseph P.

    2007-01-01

    Ground-level ozone at high levels poses health threats to exposed flora and fauna, including negative impacts to human health. While concern is common regarding depletion of ozone in the stratosphere, portions of the urban and rural United States periodically have high ambient levels of tropospheric ozone on the ground. Ozone pollution can cause a variety of impacts to susceptible vegetation (e.g., Ponderosa and Jeffrey pine species in the southwestern United States), such as stunted growth, alteration of growth form, needle or leaf chlorosis, and impaired ability to withstand drought-induced water stress. In addition, Southern Californian forests with high ozone exposures have been recently subject to multiyear droughts that have led to extensive forest overstory mortality from insect outbreaks and increased incidence of wildfires. Residual forests in these impacted areas may be more vulnerable to high ozone exposures and to other forest threats than ever before. NASA sensors collect a wealth of atmospheric data that have been used recently for mapping and monitoring regional tropospheric ozone levels. AIRS (Atmospheric Infrared Sounder), OMI (Ozone Monitoring Instrument), MLS (Microwave Limb Sounder), and TES (Tropospheric Emission Spectrometer) data could be used to assess forest ecosystem exposure to ozone. Such NASA data hold promise for providing better or at least complementary synoptic information on ground-level ozone levels that Federal agency partners can use to assess forest health trends and to mitigate the threats as needed in compliance with Federal laws and mandates. NASA data products on ozone concentrations may be able to aid applications of DSTs (decision support tools) adopted by the USDA FS (U.S. Department of Agriculture Forest Service) and by the NPS (National Park Service), such as the Ozone Calculator, in which ground ozone estimates are employed to assess ozone impacts to forested vegetation.

  9. Prolonged daily light exposure increases body fat mass through attenuation of brown adipose tissue activity

    PubMed Central

    Kooijman, Sander; van den Berg, Rosa; Ramkisoensing, Ashna; Boon, Mariëtte R.; Kuipers, Eline N.; Loef, Marieke; Zonneveld, Tom C. M.; Lucassen, Eliane A.; Sips, Hetty C. M.; Chatzispyrou, Iliana A.; Houtkooper, Riekelt H.; Meijer, Johanna H.; Coomans, Claudia P.; Biermasz, Nienke R.; Rensen, Patrick C. N.

    2015-01-01

    Disruption of circadian rhythmicity is associated with obesity and related disorders, including type 2 diabetes and cardiovascular disease. Specifically, prolonged artificial light exposure associates with obesity in humans, although the underlying mechanism is unclear. Here, we report that increasing the daily hours of light exposure increases body adiposity through attenuation of brown adipose tissue (BAT) activity, a major contributor of energy expenditure. Mice exposed to a prolonged day length of 16- and 24-h light, compared with regular 12-h light, showed increased adiposity without affecting food intake or locomotor activity. Mechanistically, we demonstrated that prolonged day length decreases sympathetic input into BAT and reduces β3-adrenergic intracellular signaling. Concomitantly, prolonging day length decreased the uptake of fatty acids from triglyceride-rich lipoproteins, as well as of glucose from plasma selectively by BAT. We conclude that impaired BAT activity is an important mediator in the association between disturbed circadian rhythm and adiposity, and anticipate that activation of BAT may overcome the adverse metabolic consequences of disturbed circadian rhythmicity. PMID:25964318

  10. Pulmonary function and symptom responses after 6. 6-hour exposure to 0. 12-ppm ozone with moderate exercise (journal version)

    SciTech Connect

    Folinsbee, L.J.; Horstman, D.H.; McDonnell, W.F.

    1988-01-01

    Episodes occasionally occur when ambient ozone (O/sub 3/) levels remain at or near 0.12 ppm for more than 6 h. The hypothesis that prolonged exposure to 0.12 ppm O/sub 3/ would result in progressively larger changes in respiratory function and symptoms over time was tested. Ten nonsmoking males (18-35 yr) were exposed once to clear air (CA) and once to 0.12 pp, O/sub 3/ for 6.75 h. Exposures consisted of six 50-min exercise periods, each followed by 10-min rest and measurement; a 45-min lunch period followed the third exercise period. Exercise ventilation averaged approximately 40 1/min. Forced expiratory and inspiratory spirometry and respiratory symptoms were measured prior to exposure and after each exercise. Increases in the symptom ratings of cough and pain on deep inspiration were observed with O/sub 3/ exposure but not with CA. Airway reactivity to methacholine was approximately doubled following O/sub 3/ exposure. Spirometry results indicate that prolonged exposure to 0.12 ppm O/sub 3/ results in a marked increase in non-specific airway reactivity and progressive changes in respiratory function.

  11. Ozone influence on native vegetation in the Jizerske hory Mts. of the Czech Republic: results based on ozone exposure and ozone-induced visible symptoms.

    PubMed

    Hůnová, Iva; Matoušková, Leona; Srněnský, Radek; Koželková, Klára

    2011-12-01

    Ozone levels in the Jizerske hory Mts. measured at 13 sites by diffusive samplers during the 2006 and 2007 vegetation seasons are presented. A significant ozone gradient (5.4 ppb in 2006 and 4.0 ppb in 2007) per 100 m difference in altitude between 370 and 1,100 m a.s.l. was recorded. High-resolution maps of phytotoxic potential were developed. The AOT40 threshold (5 ppm h) was exceeded over the entire area with the highest levels exceeding this threshold by 12 times in the upper portions of the mountains. Ozone visible injury was evaluated at four of the monitoring sites on seven native plant and tree species. Four species showed ozone-like symptoms, two of which (Rubus idaeus and Fagus sylvatica) were confirmed as ozone-induced. Our results indicate that ambient ozone is likely to have a much lower impact on the Jizerske hory Mts. vegetation than expected, considering the measured ambient ozone exposures and favourable environmental conditions for ozone uptake. PMID:21374050

  12. Effects of long-term exposure to low levels of ozone: a review

    SciTech Connect

    Melton, C.E.

    1982-02-01

    Available literature regarding long-term effects of ozone on animals and humans is reviewed. Emphasis is placed on reports that have appeared since 1976, but some earlier reports are cited for completeness and perspective. This review shows that ozone concentration is more important than duration of exposure in determining the effects of an ozone exposure (dose). This conclusion calls into question the validity of the Time-Weighted Average (TWA) as an index of severity of ozone exposure. The literature review further reveals a wide variation in susceptibility of different animal species to ozone, making it difficult to apply results of animal experiments to humans. It further appears that a dose of ozone that is acutely innocuous is also innocuous over the long term. The effects of a symptom-producing dose of ozone are initially cumulative for the first two or three exposures; then an adaptive response may ensue that involves a plateau of response or even reversal. These effects are shown by both animals and humans. The mechanisms are unknown. Ozone probably causes damage by the free radical formation. Free radical scavengers, such as vitamin E and C, may provide protection against ozone damage.

  13. Diel trend in plant sensitivity to ozone: Implications for exposure- and flux-based ozone metrics

    NASA Astrophysics Data System (ADS)

    Grantz, David A.

    2014-12-01

    Plant sensitivity to ozone (O3) is critical to modeling impacts of air pollution on vegetation. A diel timecourse of sensitivity (S) was recently determined in Pima cotton (Grantz et al., 2013). The sensitivity parameter serves as a weighting factor for stomatal uptake (ozone flux, F), or cumulative F (dose, D). Previous approaches used various weighting schemes to modify ozone concentration ([O3]) or cumulative [O3] (exposure, E). Use of the S parameter allows calculation of effective flux (Feff) and effective dose (Deff). Though theoretically sound, the practical significance of S has not been evaluated due to the previous lack of available data. Here, the newly available S parameter is used to explore the relationships between exposure- and flux-based O3 metrics in response to scenarios of contrasting stomatal conductance (gs) and ambient [O3]. The O3 scenarios were similar but differed in timing of peak [O3]. E varied by up to 13.7%, D by up to 15.4%, and Deff, which factors in sensitivity, by up to 19.0%. The gs scenarios differed in midday magnitude and nocturnal closure. Cumulative gs varied by 65.2%, which was attenuated in D to 49.2% and in Deff to 51.1%. A simulation of hourly [O3], F, and Feff was run using Monte Carlo techniques with a full month of ambient [O3] data. Resulting diel timecourses of [O3], F, and Feff were realistic, with the principal sources of uncertainty in the physiological parameters, gs and S. Analysis of hourly values from the scenarios and the simulation output demonstrated significant correlation among the O3 metrics. However, the uncertainty in both F and Feff predicted from [O3] was large and proportional to [O3], yielding greatest uncertainty under conditions of high [O3] and potential phytotoxicity. In contrast, Feff was significantly correlated with F, with low variability that was not proportional to F. As a result, uncertainty was low and prediction potentially useful under conditions of likely injury. These results

  14. Effects of prolonged exposure to space flight factors for 175 days on lettuce seeds

    NASA Astrophysics Data System (ADS)

    Nevzgodina, L. V.; Maximova, E. N.; Akatov, Yu. A.

    We have studied the effects of prolonged (up to 175 days) exposure of Lactuca sativa seeds to space flight factors, including primary cosmic radiation heavy ions. The data obtained evidence a significant fourfold increase ofs pontaneous mutagenesis in seeds both with regard to the total number of aberrant cells as well as the formation of single cells with multiple aberrations. Comparison of the present experiment with earlier works shows that the frequency of such aberrations increases with the duration of the flight.

  15. Effects of prolonged exposure to space flight factors for 175 days on lettuce seeds

    SciTech Connect

    Nevzgodina, L.V.; Maximova, E.N.; Akatov, Yu.A.

    1981-01-01

    The effects of prolonged (up to 175 days) exposure of Lactuca sativa seeds to space flight factors, including primary cosmic radiation heavy ions have been studied. The data obtained evidence a significant fourfold increase of spontaneous mutagenesis in seeds both with regard to the total number of aberrant cells as well as the formation of single cells with multiple aberrations. Comparison of the present experiment with earlier works shows that the frequency of such aberrations increases with the duration of the flight.

  16. Does ozone exposure alter growth and carbon allocation of mycorrhizal plants

    SciTech Connect

    Yoshida, L.C.; Gamon, J.A. ); Andersen, C.P. )

    1994-06-01

    Ozone is known to adversely affect plant growth. However, it is less clear how ozone affects belowground processes. This study tests the hypothesis that ozone alters growth and carbon allocation of vesicular arbuscular mycorrhizal (VAM) plants. Two ecotypes of Elymus glaucus (blue wild rye) were exposed to mycorrhizal inoculation and episodic ozone exposures simulating atmospheric conditions in the Los Angeles Basin. Preliminary results show that effects of ozone on growth were subtle. In both ecotypes, growth of aboveground biomass was not affected by ozone while root growth was decreased. In most treatments, mycorrhizal inoculation decreased growth of leaves and stems, but had no significant effect on root growth. Three-way ANOVA tests indicated interactive effects between ecotype, mycorrhiza and ozone. Further experimental work is needed to reveal the biological processes governing these responses.

  17. Secretory vesicle rebound hyperacidification and increased quantal size due to prolonged methamphetamine exposure

    PubMed Central

    Markov, Dmitriy; Mosharov, Eugene V.; Setlik, Wanda; Gershon, Michael D.; Sulzer, David

    2009-01-01

    Acute exposure to amphetamines collapses secretory vesicle pH gradients, which increases cytosolic catecholamine levels while decreases the quantal size of catecholamine release during fusion events. Amphetamine and methamphetamine, however, are retained in tissues over long durations. We used optical and electron microscopic probes to measure the effects of long-term methamphetamine exposure on secretory vesicle pH, and amperometry and intracellular patch electrochemistry to observe the effects on neurosecretion and cytosolic catecholamines in cultured rat chromaffin cells. In contrast to acute methamphetamine effects, exposure to the drug for 6–48 h at 10 μM and higher concentrations produced a concentration-dependent rebound hyperacidification of secretory vesicles. At 5–10 μM levels, methamphetamine increased the quantal size and reinstated exocytotic catecholamine release, although very high (>100 μM) levels of the drug, while continuing to produce rebound hyperacidification, did not increase quantal size. Secretory vesicle rebound hyperacidification was temperature dependent with optimal response at ~ 37°C, was not blocked by the transcription inhibitor, puromycin, and appears to be a general compensatory response to prolonged exposure with membranophilic weak bases, including amphetamines, methylphenidate, cocaine, and ammonia. Thus, under some conditions of prolonged exposure, amphetamines and other weak bases can enhance, rather than deplete, the vesicular release of catecholamines via a compensatory response resulting in vesicle acidification. PMID:19014382

  18. Increased radiation dose at mammography due to prolonged exposure, delayed processing, and increased film darkening

    SciTech Connect

    Kimme-Smith, C.; Bassett, L.W.; Gold, R.H.; Chow, S. )

    1991-02-01

    Four single-emulsion films introduced over the past 2 years--Du Pont Microvision, Fuji MiMa, Konica CM, and Eastman Kodak OM--were compared with Eastman Kodak OM SO-177 (Min-RE) film to evaluate their varying effects on mean glandular dose of reciprocity law failure due to prolonged exposure, delayed processing, and increased film darkening as a result of increased radiation exposure to improve penetration of glandular tissue. Exposures over 1.3 seconds led to increased radiation doses of 20%-30%. Delays in processing of 6 hours decreased processing speed by 11%-32% for all films except Du Pont Microvision. Optical density increases of 0.40 required 20%-30% more skin exposure for all five films. Optimal viewing densities were also evaluated and found to be different for each of the five films. Mammographers need to be aware of these differences in mammographic films to achieve maximum contrast at mammography.

  19. Ozone Exposure Alters Serotonin and Serotonin Receptor Expression in the Developing Lung

    PubMed Central

    Van Winkle, Laura S.

    2013-01-01

    Ozone, a pervasive environmental pollutant, adversely affects functional lung growth in children. Animal studies demonstrate that altered lung development is associated with modified signaling within the airway epithelial mesenchymal trophic unit, including mediators that can change nerve growth. We hypothesized that ozone exposure alters the normal pattern of serotonin, its transporter (5-HTT), and two key receptors (5-HT2A and 5-HT4), a pathway involved in postnatal airway neural, epithelial, and immune processes. We exposed monkeys to acute or episodic ozone during the first 2 or 6 months of life. There were three exposure groups/age: (1) filtered air, (2) acute ozone challenge, and (3) episodic ozone + acute ozone challenge. Lungs were prepared for compartment-specific qRT-PCR, immunohistochemistry, and stereology. Airway epithelial serotonin immunopositive staining increased in all exposure groups with the most prominent in 2-month midlevel and 6-month distal airways. Gene expression of 5-HTT, 5-HT2AR, and 5-HT4R increased in an age-dependent manner. Overall expression was greater in distal compared with midlevel airways. Ozone exposure disrupted both 5-HT2AR and 5-HT4R protein expression in airways and enhanced immunopositive staining for 5-HT2AR (2 months) and 5-HT4R (6 months) on smooth muscle. Ozone exposure increases serotonin in airway epithelium regardless of airway level, age, and exposure history and changes the spatial pattern of serotonin receptor protein (5-HT2A and 5-HT4) and 5-HTT gene expression depending on compartment, age, and exposure history. Understanding how serotonin modulates components of reversible airway obstruction exacerbated by ozone exposure sets the foundation for developing clinically relevant therapies for airway disease. PMID:23570994

  20. AN EVALUATION OF OZONE EXPOSURE METRICS FOR A SEASONALLY DROUGHT STRESSED PONDEROSA PINE ECOSYSTEM. (R826601)

    EPA Science Inventory

    Ozone stress has become an increasingly significant factor in cases of forest decline reported throughout the world. Current metrics to estimate ozone exposure for forest trees are derived from atmospheric concentrations and assume that the forest is physiologically active at ...

  1. Systemic Metabolic Derangement, Pulmonary Effects, and Insulin Insufficiency following subchronic ozone exposure in rats

    EPA Science Inventory

    Acute ozone exposure induces a classical stress response with elevated circulating stress hormones along with changes in glucose, protein and lipid metabolism in rats, with similar alterations in ozone-exposed humans. These stress-mediated changes over time have been linked to in...

  2. Low level ozone exposure induces airways inflammation and modifies cell surface phenotypes in healthy humans

    EPA Science Inventory

    Background: The effects of low level ozone exposure (0.08 ppm) on pulmonary function in healthy young adults are well known, however much less is known about the inflammatory and immuno-modulatory effects oflow level ozone in the airways. Techniques such as induced sputum and flo...

  3. DETECTION OF RADICALS PRODUCED IN VIVO DURING INHALATION EXPOSURE TO OZONE: USE OF VARIOUS SPIN TRAPS

    EPA Science Inventory

    Ozone is known to induce lipid peroxidation of lung tissue, although no direct evidence of free radical formation has been reported. e have used the electron paramagnetic resonance (EPR) spin-trapping technique to search for free radicals produced in vivo by ozone exposure. he sp...

  4. Home cage locomotor changes in non-human primates after prolonged welding-fume exposure.

    PubMed

    Kim, Choong Yong; Sung, Jae Hyuck; Chung, Yong Hyun; Park, Jung Duck; Han, Jeong Hee; Lee, Jong Seong; Heo, Jeong Doo; Yu, Il Je

    2013-12-01

    To define the relationship between the brain concentration of manganese and neurological signs, such as locomotion, after prolonged welding-fume exposure, cynomolgus monkeys were acclimated for 1 month and then divided into three concentration groups: unexposed, low concentration (31 mg/m(3) total suspended particulate (TSP), 0.9 mg/m(3) of Mn), and high concentration (62 mg/m(3) TSP, 1.95 mg/m(3) of Mn) of TSP. The monkeys were exposed to manual metal-arc stainless steel (MMA-SS) welding fumes for 2 h per day over 8 months in an inhalation chamber system equipped with an automatic fume generator. The home cage locomotor activity and patterns were determined using a camera system over 2-4 consecutive days. After 25 and 32 weeks of exposure, the home cage locomotor activity of the high-concentration primates was found to be 5-6 times higher than that of the unexposed primates, and this increased locomotor activity was maintained for 7 weeks after ceasing the welding-fume exposure, eventually subsiding to three times higher after 13 weeks of recovery. Therefore, the present results, along with our previous observations of a high magnetic resonance imaging (MRI) T1 signal in the globus pallidus and increased blood Mn concentration, indicate that prolonged welding-fume exposure can cause neurobehavioral changes in cynomolgus monkeys. PMID:24304306

  5. Short and prolonged exposure to hyperglycaemia in human fibroblasts and endothelial cells: metabolic and osmotic effects.

    PubMed

    Moruzzi, Noah; Del Sole, Marianna; Fato, Romana; Gerdes, Jantje M; Berggren, Per-Olof; Bergamini, Christian; Brismar, Kerstin

    2014-08-01

    High blood glucose levels are the main feature of diabetes. However, the underlying mechanism linking high glucose concentration to diabetic complications is still not fully elucidated, particularly with regard to human physiology. Excess of glucose is likely to trigger a metabolic response depending on the cell features, activating deleterious pathways involved in the complications of diabetes. In this study, we aim to elucidate how acute and prolonged hyperglycaemia alters the biology and metabolism in human fibroblasts and endothelial cells. We found that hyperglycaemia triggers a metabolic switch from oxidative phosphorylation to glycolysis that is maintained over prolonged time. Moreover, osmotic pressure is a major factor in the early metabolic response, decreasing both mitochondrial transmembrane potential and cellular proliferation. After prolonged exposure to hyperglycaemia we observed decreased mitochondrial steady-state and uncoupled respiration, together with a reduced ATP/ADP ratio. At the same time, we could not detect major changes in mitochondrial transmembrane potential and reactive oxygen species. We suggest that the physiological and metabolic alterations observed in healthy human primary fibroblasts and endothelial cells are an adaptive response to hyperglycaemia. The severity of metabolic and bioenergetics impairment associated with diabetic complications may occur after longer glucose exposure or due to interactions with cell types more sensitive to hyperglycaemia. PMID:24814290

  6. Long-Term Exposure to Ozone and Life Expectancy in the United States, 2002 to 2008.

    PubMed

    Li, Chaoyang; Balluz, Lina S; Vaidyanathan, Ambarish; Wen, Xiao-Jun; Hao, Yongping; Qualters, Judith R

    2016-02-01

    Long-term exposure to ground-level ozone is associated with increased risk of morbidity and mortality. The association remains uncertain between long-term exposure to ozone and life expectancy. We assessed the associations between seasonal mean daily 8-hour maximum (8-hr max) ozone concentrations measured during the ozone monitoring seasons and life expectancy at birth in 3109 counties of the conterminous U.S. during 2002 to 2008. We used latent class growth analysis to identify latent classes of counties that had distinct mean levels and rates of change in ozone concentrations over the 7-year period and used linear regression analysis to determine differences in life expectancy by ozone levels. We identified 3 classes of counties with distinct seasonal mean daily 8-hr max ozone concentrations and rates of change. When compared with the counties with the lowest ozone concentrations, the counties with the highest ozone concentrations had 1.7- and 1.4-year lower mean life expectancy in males and females (both P < 0.0001), respectively. The associations remained statistically significant after controlling for potential confounding effects of seasonal mean PM2.5 concentrations and other selected environmental, demographic, socio-economic, and health-related factors (both P < 0.0001). A 5 ppb higher ozone concentration was associated with 0.25 year lower life expectancy in males (95% CI: -0.30 to -0.19) and 0.21 year in females (95% CI: -0.25 to -0.17). We identified 3 classes of counties with distinct mean levels and rates of change in ozone concentrations. Our findings suggest that long-term exposure to a higher ozone concentration may be associated with a lower life expectancy. PMID:26886595

  7. Long-Term Exposure to Ozone and Life Expectancy in the United States, 2002 to 2008

    PubMed Central

    Li, Chaoyang; Balluz, Lina S.; Vaidyanathan, Ambarish; Wen, Xiao-Jun; Hao, Yongping; Qualters, Judith R.

    2016-01-01

    Abstract Long-term exposure to ground-level ozone is associated with increased risk of morbidity and mortality. The association remains uncertain between long-term exposure to ozone and life expectancy. We assessed the associations between seasonal mean daily 8-hour maximum (8-hr max) ozone concentrations measured during the ozone monitoring seasons and life expectancy at birth in 3109 counties of the conterminous U.S. during 2002 to 2008. We used latent class growth analysis to identify latent classes of counties that had distinct mean levels and rates of change in ozone concentrations over the 7-year period and used linear regression analysis to determine differences in life expectancy by ozone levels. We identified 3 classes of counties with distinct seasonal mean daily 8-hr max ozone concentrations and rates of change. When compared with the counties with the lowest ozone concentrations, the counties with the highest ozone concentrations had 1.7- and 1.4-year lower mean life expectancy in males and females (both P < 0.0001), respectively. The associations remained statistically significant after controlling for potential confounding effects of seasonal mean PM2.5 concentrations and other selected environmental, demographic, socio-economic, and health-related factors (both P < 0.0001). A 5 ppb higher ozone concentration was associated with 0.25 year lower life expectancy in males (95% CI: −0.30 to −0.19) and 0.21 year in females (95% CI: −0.25 to −0.17). We identified 3 classes of counties with distinct mean levels and rates of change in ozone concentrations. Our findings suggest that long-term exposure to a higher ozone concentration may be associated with a lower life expectancy. PMID:26886595

  8. Prolonged Exposure for Guilt and Shame in a Veteran of Operation Iraqi Freedom

    PubMed Central

    Paul, Lisa A.; Gros, Daniel F.; Strachan, Martha; Worsham, Glenna; Foa, Edna B.; Acierno, Ron

    2014-01-01

    Morally injurious events appear capable of producing posttraumatic stress disorder (PTSD), even though they may not involve actual or perceived life-threat or a response of fear, horror, or helplessness. Researchers have questioned whether exposure therapies can address these events. The current report presents evidence of the effectiveness of this treatment approach for addressing posttraumatic symptoms related to a morally injurious event through an illustrative case of an Operation Iraqi Freedom veteran with PTSD characterized by symptoms of guilt and shame. The veteran was successfully treated with nine sessions of prolonged exposure therapy, reporting minimal PTSD symptoms one week post-treatment and at a six-month follow-up assessment. Implications for the treatment of veterans with significant guilt and shame using exposure-based therapies, and with respect to the recent changes to the diagnostic criteria for PTSD, are discussed. PMID:25505798

  9. Germination of fungal conidia after exposure to low concentration ozone atmospheres.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The germinability of conidia of Alternaria alternata, Aspergillus flavus, Aspergillus niger, Penicillium digitatum, Penicillium expansum, or Penicillium italicum was determined periodically during exposure for approximately 100 days to a humid atmosphere of air alone or air containing 150 ppb ozone ...

  10. Ozone Exposure Increases Circulating Stress Hormones and Lipid Metabolites in Humans

    EPA Science Inventory

    RATIONALE: Air pollution has been associated with increased prevalence of type 2 diabetes; however, the mechanisms remain unknown. We have shown that acute ozone exposure in rats induces release of stress hormones, hyperglycemia, leptinemia, and gluoose intolerance that are assoc...

  11. OZONE DECREASES SPRING ROOT GROWTH AND ROOT CARBOHYDRATE CONTENT IN PONDEROSA PINE THE YEAR FOLLOWING EXPOSURE

    EPA Science Inventory

    Storage carbohydrates are extremely important for new shoot and root development following dormancy or during periods of high stress. he hypothesis that ozone decreases carbohydrate storage and decreases new root growth during the year following exposure was investigated. eedling...

  12. Controlled exposure of healthy young volunteers to ozone causes cardiovascular effects**

    EPA Science Inventory

    Background: Recent epidemiology studies have reported associations between acute ozone exposure and mortality. Such studies have previously reported associations between airborne particulate matter pollution (PM) and mortality and support for a causal relationship has come from c...

  13. Controlled Exposure of Healthy Young Volunteers to Ozone Causes Cardiovascular Effects

    EPA Science Inventory

    Background: Recent epidemiology studies have reported associations between acute ozone exposure and mortality. Such studies have previously reported associations between airborne particulate matter pollution (PM) and mortality and support for a causal relationship has come from c...

  14. Effect of ozone exposure on lung functions and plasma prostaglandin and thromboxane concentrations in guinea pigs

    SciTech Connect

    Miller, P.D.; Ainsworth, D.; Lam, H.F.; Amdur, M.O.

    1987-03-30

    Male Hartley guinea pigs were exposed either to filtered air or to 1 ppm ozone (O/sub 3/) for 1 hr. At 2, 8, 24, or 48 hr after exposure we measured ventilation, respiratory mechanics, lung volumes, diffusing capacity for carbon monoxide (DLCO), and alveolar volume (VA) in anesthetized, tracheotomized animals. Respiratory frequency and tidal volume were unchanged in all groups. Pulmonary resistance was increased 2 hr after O/sub 3/ but returned to control at 8 hr and thereafter. Prolonged reductions in lung volumes (total lung capacity, vital capacity, functional residual capacity, and residual volume) as well as in DLCO and VA occurred after O/sub 3/, with maximum decreases at 8 and 24 hr postexposure. Increased ratios of wet lung weight to body weight were seen at 2, 8, and 24 hr. In separate groups of animals, also exposed either to filtered air or to 1 ppm O/sub 3/, plasma eicosanoid (EC) concentrations were measured at 2, 8, 24, 48, or 72 hr after exposure. Significant increases in thromboxane B2 concentrations were seen at 2, 24, and 48 hr after exposure. Plasma concentrations of 6-keto prostaglandin F1 alpha (PGF1 alpha) and prostaglandin E1 (PGE1) were increased at 24 hr and at 24, 48, and 72 hr, respectively. The nature of this long-term pulmonary response to a short-term exposure to O/sub 3/ suggests alveolar involvement, including probable alveolar duct constriction and localized pulmonary edema. Although changes in plasma EC concentrations were observed concurrent with impaired lung functions, no simple causal relationship was apparent from these studies.

  15. Effects of prolonged exposure to perchlorate on thyroid and reproductive function in zebrafish

    USGS Publications Warehouse

    Mukhi, S.; Patino, R.

    2007-01-01

    The objectives of this study were to determine the effects of prolonged exposure to perchlorate on (1) thyroid status and reproductive performance of adult zebrafish (Danio rerio) and (2) F1 embryo survival and early larval development. Using a static-renewal procedure, mixed sex populations of adult zebrafish were exposed to 0, 10, and 100 mg/l nominal concentrations of waterborne perchlorate for 10 weeks. Thyroid histology was qualitatively assessed, and females and males were separated and further exposed to their respective treatments for six additional weeks. Eight females in each tank replicate (n = 3) were paired weekly with four males from the same respective treatment, and packed-egg (spawn) volume (PEV) was measured each of the last five weeks. At least once during weeks 14-16 of exposure, other end points measured included fertilization rate, fertilized egg diameter, hatching rate, standard length, and craniofacial development of 4-day-postfertilization larvae and thyroid hormone content of 3.5-h embryos and of exposed mothers. At 10 weeks of exposure, perchlorate at both concentrations caused thyroidal hypertrophy and colloid depletion. A marked reduction in PEV was observed toward the end of the 6-week spawning period, but fertilization and embryo hatching rates were unaffected. Fertilized egg diameter and larval length were increased by parental exposure to perchlorate. Larval head depth was unaffected but the forward protrusion of the lower jaw-associated cartilage complexes, Meckel's and ceratohyal, was decreased. Exposure to both concentrations of perchlorate inhibited whole-body thyroxine content in mothers and embryos, but triiodothyronine content was unchanged. In conclusion, prolonged exposure of adult zebrafish to perchlorate not only disrupts their thyroid endocrine system but also impairs reproduction and influences early F1 development. ?? 2007 Oxford University Press.

  16. Monitoring of Occupational Exposure of Mild Steel Welders to Ozone and Nitrogen Oxides

    PubMed Central

    Esmaeilzadeh, Morteza; Mehrabi, Yadollah; Salehpour, Sousan

    2011-01-01

    Background Metal Inert Gas (MIG) welding and Tungsten Inert Gas (TIG) welding are widely used for mild steel segments in basic metal industries. Pulmonary problems such as asthma, pulmonary inflammation, hyper-responsiveness of airways and higher susceptibility to infections are reported as the result of occupational exposure of welders to ozone and nitrogen oxides. Potent oxidizing agents like ozone and nitrogen oxides are also reported to be a precursor for respiratory problems and cause lipid peroxidation of membranes. Materials and Methods A total of 43 nonsmoking MIG and TIG welders and 41 nonsmoking workers without appreciable exposure to any chemicals as the control population were chosen to participate in this study. Occupational exposure to ozone was monitored according to the validated methods. Malondialdehyde (MDA) of blood serum as a biomarker for lipid peroxidation was analyzed using Reverse Phase High Performance Liquid Chromatography. Data obtained from this study were analyzed using t-test, Pearson's correlation coefficient and multiple regression analysis. Results A total of 88.4% and 74.4% of welders had exposure to ozone and nitrogen dioxide higher than the permissible limit of occupational exposure, respectively. Generally, exposure of MIG welders to ozone was significantly higher than TIG welders (P = 0.006). However, exposure to nitrogen dioxide gas was comparable in both groups. Serum MDA of welders was significantly higher than that of the control group (P = 0.001). A significant correlation was detected between ozone exposure and level of serum malondialdehyde. Such correlation was not observed for nitrogen dioxide exposure. Conclusion Considering the high exposure of welders to ozone and nitrogen dioxide, and higher level of serum malondialdehyde in them compared to controls, risk management is recommended for this group of workers. PMID:25191389

  17. Pulmonary function and symptom responses after 6. 6-hour exposure to 0. 12 ppm ozone with moderate exercise

    SciTech Connect

    Folinsbee, L.J.; McDonnell, W.F.; Horstman, D.H.

    1988-01-01

    Episodes occasionally occur when ambient ozone (O/sub 3/) levels remain at or near 0.12 ppm for more than 6 h. Small decrements in lung function have been reported following 2-h exposures to 0.12 ppm O/sub 3/. For short exposures to higher O/sub 3/ concentrations, lung function decrements are a function of exposure duration. Thus, we investigated the hypothesis that prolonged exposure to 0.12 ppm O/sub 3/ would result in progressively larger changes in respiratory function and symptoms over time. Ten nonsmoking males were exposed once to clean air and once to 0.12 ppm O/sub 3/ for 6.6 h. Exposures consisted of six 50-min exercise periods, each followed by 10-min rest and measurement; a 35-min lunch period followed by the third exercise period. Exercise ventilation averaged approximately 40 L/min. Forced expiratory and inspiratory spirometry and respiratory symptoms were measured prior to exposure and after each exercise. Airway reactivity to methacholine was determined after each exposure. After correcting for the air exposures, FEV 1.0 was found to decrease linearly during the O/sub 3/ exposure and was decreased by an average of 13.0 percent at the end of exposure. Decreases in FVC and FEF24-75% were also linear and averaged 8.3 and 17.4 percent, respectively, at the end of exposure. On forced inspiratory tests, the FIVC and FIV05 were decreased 12.6 and 20.7 percent, respectively. Increases in the symptom ratings of cough and pain on deep inspiration were observed with O/sub 3/ exposure but not with clean air. Airway reactivity to methacholine was approximately doubled following O/sub 3/ exposure.

  18. Human physiological responses to cold exposure: Acute responses and acclimatization to prolonged exposure.

    PubMed

    Castellani, John W; Young, Andrew J

    2016-04-01

    Cold exposure in humans causes specific acute and chronic physiological responses. This paper will review both the acute and long-term physiological responses and external factors that impact these physiological responses. Acute physiological responses to cold exposure include cutaneous vasoconstriction and shivering thermogenesis which, respectively, decrease heat loss and increase metabolic heat production. Vasoconstriction is elicited through reflex and local cooling. In combination, vasoconstriction and shivering operate to maintain thermal balance when the body is losing heat. Factors (anthropometry, sex, race, fitness, thermoregulatory fatigue) that influence the acute physiological responses to cold exposure are also reviewed. The physiological responses to chronic cold exposure, also known as cold acclimation/acclimatization, are also presented. Three primary patterns of cold acclimatization have been observed, a) habituation, b) metabolic adjustment, and c) insulative adjustment. Habituation is characterized by physiological adjustments in which the response is attenuated compared to an unacclimatized state. Metabolic acclimatization is characterized by an increased thermogenesis, whereas insulative acclimatization is characterized by enhancing the mechanisms that conserve body heat. The pattern of acclimatization is dependent on changes in skin and core temperature and the exposure duration. PMID:26924539

  19. CHRONIC EXPOSURE TO OZONE CAUSES RESTRICTIVE LUNG DISEASE

    EPA Science Inventory

    A chronic study to determine the progression and or/reversibility of ozone-induced lung disease was conducted. ale rats were exposed to a diurnal pattern of ozone (O3) for 1 wk, 3 wk, 3 mo, 12 mo, or 18 mo. he occurrence of chronic lung disease was determined by structural and fu...

  20. Long-Term Ozone Exposure Attenuates 1-Nitronaphthalene–Induced Cytotoxicity in Nasal Mucosa

    PubMed Central

    Lee, Myong Gyong; Wheelock, Åsa M.; Boland, Bridget; Plopper, Charles G.

    2008-01-01

    1-Nitronaphthalene (1-NN) and ozone are cytotoxic air pollutants commonly found as components of photochemical smog. The mechanism of toxicity for 1-NN involves bioactivation by cytochrome P450s and subsequent adduction to proteins. Previous studies have shown that 1-NN toxicity in the lung is considerably higher in rats after long-term exposure to ozone compared with the corresponding filtered air–exposed control rats. The aim of the present study was to establish whether long-term exposure to ozone alters the susceptibility of nasal mucosa to the bioactivated toxicant, 1-NN. Adult male Sprague-Dawley rats were exposed to filtered air or 0.8 ppm ozone for 8 hours per day for 90 days, followed by a single treatment with 0, 12.5, or 50.0 mg/kg 1-NN by intraperitoneal injection. The results of the histopathologic analyses show that the nasal mucosa of rats is a target of systemic 1-NN, and that long-term ozone exposure markedly lessens the severity of injury, as well as the protein adduct formation by reactive 1-NN metabolites. The antagonistic effects were primarily seen in the nasal transitional epithelium, which corresponds to the main site of histologic changes attributed to ozone exposure (goblet cell metaplasia and hyperplasia). Long-term ozone exposure did not appear to alter susceptibility to 1-NN injury in other nasal regions. This study shows that long-term ozone exposure has a protective effect on the susceptibility of nasal transitional epithelium to subsequent 1-NN, a result that clearly contrasts with the synergistic toxicological effect observed in pulmonary airway epithelium in response to the same exposure regimen. PMID:17901409

  1. Surface morphology and morphometry of rat alveolar macrophages after ozone exposure

    SciTech Connect

    Dormans, J.A.; Rombout, P.J.; van Loveren, H. )

    1990-09-01

    As the ultrastructural data on the effects of ozone on pulmonary alveolar macrophages (PAM) are lacking, transmission (TEM) and scanning (SEM) electron microscopy were performed on rat PAM present in alveolar lavages following exposure to ozone. Rats were continuously exposed for 7 d to ozone concentrations ranging from 0.25 to 1.50 mg/m3 for 7 d followed by a 5-d recovery period. Additionally, morphometry on lung sections was performed to quantitate PAM. In a second experiment rats were continuously exposed to 1.50 mg O3/m3 for 1, 3, 5, or 7 d. To study the influence of concurrent ozone exposure and lung infection, due to Listeria monocytogenes, rats were exposed for 7 d to 1.50 mg O3/m3 after a Listeria infection. The surface area of lavaged control PAM was uniformly covered with ruffles as shown by SEM and TEM. Exposure to 0.5 mg ozone/m3 for 7 d resulted in cells partly covered with microvilli and blebs in addition to normal ruffles. The number of large size PAM increased with an increase in ozone concentration. After 1 d of exposure, normal-appearing as well as many small macrophages with ruffles and scattered lymphocytes were seen. Lavage samples taken after 5 or 7 d of exposure showed an identical cell composition to that taken after 3 d of exposure. After Listeria infection alone, lavage samples consisted of mainly lymphocytes and some macrophages. Small quantitative changes, such as an increase in the number of polymorphonuclear neutrophils and large-size PAM, occurred in lavages after ozone exposure and infection with L. monocytogenes. Morphometric examination of lung sections revealed a concentration-related increase in the number of PAM, even in animals exposed to 0.25 mg ozone/m3 for 7 d. Centriacinar regions were more severely affected than other regions of lung tissue.

  2. Ozone exposure and systemic biomarkers: Evaluation of evidence for adverse cardiovascular health impacts.

    PubMed

    Goodman, Julie E; Prueitt, Robyn L; Sax, Sonja N; Pizzurro, Daniella M; Lynch, Heather N; Zu, Ke; Venditti, Ferdinand J

    2015-05-01

    The US Environmental Protection Agency (EPA) recently concluded that there is likely to be a causal relationship between short-term (< 30 days) ozone exposure and cardiovascular (CV) effects; however, biological mechanisms to link transient effects with chronic cardiovascular disease (CVD) have not been established. Some studies assessed changes in circulating levels of biomarkers associated with inflammation, oxidative stress, coagulation, vasoreactivity, lipidology, and glucose metabolism after ozone exposure to elucidate a biological mechanism. We conducted a weight-of-evidence (WoE) analysis to determine if there is evidence supporting an association between changes in these biomarkers and short-term ozone exposure that would indicate a biological mechanism for CVD below the ozone National Ambient Air Quality Standard (NAAQS) of 75 parts per billion (ppb). Epidemiology findings were mixed for all biomarker categories, with only a few studies reporting statistically significant changes and with no consistency in the direction of the reported effects. Controlled human exposure studies of 2 to 5 hours conducted at ozone concentrations above 75 ppb reported small elevations in biomarkers for inflammation and oxidative stress that were of uncertain clinical relevance. Experimental animal studies reported more consistent results among certain biomarkers, although these were also conducted at ozone exposures well above 75 ppb and provided limited information on ozone exposure-response relationships. Overall, the current WoE does not provide a convincing case for a causal relationship between short-term ozone exposure below the NAAQS and adverse changes in levels of biomarkers within and across categories, but, because of study limitations, they cannot not provide definitive evidence of a lack of causation. PMID:25959700

  3. Adjoint-based computation of U.S. nationwide ozone exposure isopleths

    NASA Astrophysics Data System (ADS)

    Ashok, Akshay; Barrett, Steven R. H.

    2016-05-01

    Population exposure to daily maximum ozone is associated with an increased risk of premature mortality, and efforts to mitigate these impacts involve reducing emissions of nitrogen oxides (NOx) and volatile organic compounds (VOCs). We quantify the dependence of U.S. national exposure to annually averaged daily maximum ozone on ambient VOC and NOx concentrations through ozone exposure isopleths, developed using emissions sensitivities from the adjoint of the GEOS-Chem air quality model for 2006. We develop exposure isopleths for all locations within the contiguous US and derive metrics based on the isopleths that quantify the impact of emissions on national ozone exposure. This work is the first to create ozone exposure isopleths using adjoint sensitivities and at a large scale. We find that across the US, 29% of locations experience VOC-limited conditions (where increased NOx emissions lower ozone) during 51% of the year on average. VOC-limited conditions are approximately evenly distributed diurnally and occur more frequently during the fall and winter months (67% of the time) than in the spring and summer (37% of the time). The VOC/NOx ratio of the ridge line on the isopleth diagram (denoting a local maximum in ozone exposure with respect to NOx concentrations) is 9.2 ppbC/ppb on average across grid cells that experience VOC-limited conditions and 7.9, 10.1 and 6.7 ppbC/ppb at the three most populous US cities of New York, Los Angeles and Chicago, respectively. Emissions that are ozone exposure-neutral during VOC-limited exposure conditions result in VOC/NOx concentration ratios of 0.63, 1.61 and 0.72 ppbC/ppb at each of the three US cities respectively, and between 0.01 and 1.91 ppbC/ppb at other locations. The sensitivity of national ozone exposure to NOx and VOC emissions is found to be highest near major cities in the US. Together, this information can be used to assess the effectiveness of NOx and VOC emission reductions on mitigating ozone exposure in the

  4. Ozone exposure and blood antioxidants: a study in a periurban area in Southern France.

    PubMed

    Saintot, M; Bernard, N; Astre, C; Gerber, M

    1999-01-01

    Major carotenoids in plasma--especially beta-carotene--are affected by oxidative stress (e.g., tobacco smoking). Environmental ozone induced oxidative stress in experimental in vitro and in vivo studies, and it also increased the incidence of lung cancer in mice. We proposed to measure, after controlling for other determinants, the impact of personal ozone exposure on carotenoids levels in plasma. During the summer, we recruited 58 volunteer subjects who worked in a periurban zone. We asked each subject to wear a passive sample, which measured ozone exposure for 5 consecutive d. At the end of this period, we assessed plasma antioxidants. We observed a negative significant regression coefficient between alpha- or beta-carotene and ozone exposure (r = -.39, p < .01, and r = -.45, p = .02, respectively). In a subsample of 45 nonsmoker subjects, among whom carotene intake was lower than the median intake value (i.e., 6.6 mg/d) of the overall group, we noted that a relatively low exposure to ozone (> or = 50 microg/m3 x h or > or = 23.8 ppb) induced a significant decrease in plasma beta-carotene levels (i.e., 0.7 micromol/l to 0.4 micromol/l). This significant decrease suggested that a high dietary intake of fruit or vegetables can have a beneficial influence on the levels of plasma antioxidants generated in response to ozone exposure. PMID:10025414

  5. Studying cumulative ozone exposures in Europe during a 7-year period

    NASA Astrophysics Data System (ADS)

    Bastrup-Birk, Annemarie; Brandt, JøRgen; Zlatev, Zahari; Uria, Ignacio

    1997-10-01

    Ozone is one of the most harmful pollutants in the troposphere. High ozone concentrations can damage plants, animals and humans. The damaging effects depend on the magnitude of a critical level of a special parameter, the cumulative ozone exposure. This is why cumulative ozone exposures must be carefully studied. It is important to determine the relationships between relevant emissions (NOx emissions, human-made VOC emissions, and/or a combination of NOx emissions and human-made VOC emissions) and cumulative ozone exposures. All these issues are discussed in this paper. Meteorological data from seven consecutive years, from 1989 to 1995, have been used in the experiments with different scenarios for varying the emissions (the NOx emissions, the human-made VOC emissions, as well as both the NOx emissions and the human-made VOC emissions). The particular air pollution model used in this study is the Danish Eulerian Model. Several hundred runs with different input data (meteorological data and/or emission data) have been performed. Advanced visualization techniques are used to interpret the large amount of digital data collected in these runs and to show clearly different trends and relationships that are normally hidden behind millions and millions of numbers. The model results were compared with measurements taken at more than 80 stations located in different European countries. The experiments indicate that it is sufficient to carry out computations over 5 consecutive years in order to eliminate the influence of extreme meteorological conditions (very warm or very cold summer months) on the cumulative ozone exposures, while this effect is clearly seen if less than 5 years are used in the experiments. It is shown that the relationship between the emissions (NOx and/or human-made VOC emissions) and the cumulative ozone exposures is in general nonlinear. Finally, it is illustrated that the critical values for ozone exposures are exceeded in most of Europe (in many

  6. Responses of subjects with chronic obstructive pulmonary disease after exposures to 0. 3 ppm ozone

    SciTech Connect

    Kehrl, H.R.; Hazucha, M.J.; Solic, J.J.; Bromberg, P.A.

    1985-05-01

    The authors previously reported that the respiratory mechanics of intermittently exercising persons with chronic obstructive pulmonary disease (COPD) were unaffected by a 2-h exposure to 0.2 ppm ozone. Employing a single-blind, cross-over design protocol, 13 white men with nonreversible COPD (9 current smokers; mean FEV1/FVC, 56%) were randomly exposed on 2 consecutive days for 2 h to air and 0.3 ppm ozone. During exposures, subjects exercised (minute ventilation, 26.4 +/- 3.0 L/min) for 7.5 min every 30 min; ventilation and gas exchange measured during exercise showed no difference between exposure days. Pulmonary function tests (spirometry, body plethysmography) obtained before and after exposures were unchanged on the air day. On the ozone day the mean airway resistance and specific airway resistance showed the largest (25 and 22%) changes (p = 0.086 and 0.058, respectively). Arterial oxygen saturation (SaO/sub 2/) obtained in 8 subjects during the last exercise interval showed a mean decrement of 0.95% on the ozone exposure day; this change did not attain significance (p = 0.074). Nevertheless, arterial oxygen desaturation may be a true consequence of low-level ozone exposure in this compromised patient group. As normal subjects undergoing exposures to ozone with slightly higher exercise intensities show a threshold for changes in their respiratory mechanics at approximately 0.3 ppm, these data indicate that persons with COPD are not unduly sensitive to the effects of low-level ozone exposure.

  7. The effect of prolonged exposure to 750 C air on the tribological performance of PM212

    NASA Technical Reports Server (NTRS)

    Bemis, Kirk; Bogdanski, Michael S.; Dellacorte, Christopher; Sliney, Harold E.

    1994-01-01

    The effect of prolonged exposure to 750 C air on the tribological performance and dimensional stability of PM212, a high temperature, self-lubricating composite, is studied. PM212, by weight, contains 70 percent metal-bonded Cr3C2, 15 percent BaF2/CaF2 eutectic, and 15 percent silver. Rub blocks were fabricated from PM212 by cold isostatic pressing followed by sintering. Prior to tribo-testing, the rub blocks were exposed to 750 C air for periods ranging from 100 to 1000 hours. Then, the rub blocks were slid against nickel-based superalloy disks in a double-rub-block tribometer in air under a 66 N load at temperatures from 25 to 750 C with a sliding velocity of 0.36 m/s. Unexposed rub blocks were tested for baseline comparison. Friction coefficients ranged from 0.24 to 0.37 for the unexposed rub blocks and from 0.32 to 0.56 for the exposed ones. Wear for both the composite blocks and superalloy disks was typically in the moderate to low range of 10(exp -5) to 10(exp -6) mm(exp 3)/N-m. Friction and wear data were similar for the rub blocks exposed for 100, 500, and 1000 hours. Prolonged exposure to 750 C air increased friction and wear of the PM212 rub blocks at room temperature, but their triboperformance remained unaffected at higher temperatures, probably due to the formation of lubricious metal oxides. Dimensional stability of the composite was studied by exposing specimens of varying thicknesses for 500 hours in air at 750 C. Block thicknesses were found to increase with increased exposure time until steady state was reached after 100 hours of exposure, probably due to oxidation.

  8. Cognitive functions and cerebral oxygenation changes during acute and prolonged hypoxic exposure.

    PubMed

    Davranche, Karen; Casini, Laurence; Arnal, Pierrick J; Rupp, Thomas; Perrey, Stéphane; Verges, Samuel

    2016-10-01

    The present study aimed to assess specific cognitive processes (cognitive control and time perception) and hemodynamic correlates using functional near-infrared spectroscopy (fNIRS) during acute and prolonged high-altitude exposure. Eleven male subjects were transported via helicopter and dropped at 14 272 ft (4 350 meters) of altitude where they stayed for 4 days. Cognitive tasks, involving a conflict task and temporal bisection task, were performed at sea level the week before ascending to high altitude, the day of arrival (D0), the second (D2) and fourth (D4) day at high altitude. Cortical hemodynamic changes in the prefrontal cortex (PFC) area were monitored with fNIRS at rest and during the conflict task. Results showed that high altitude impacts information processing in terms of speed and accuracy. In the early hours of exposure (D0), participants displayed slower reaction times (RT) and decision errors were twice as high. While error rate for simple spontaneous responses remained twice that at sea level, the slow-down of RT was not detectable after 2 days at high-altitude. The larger fNIRS responses from D0 to D2 suggest that higher prefrontal activity partially counteracted cognitive performance decrements. Cognitive control, assessed through the build-up of a top-down response suppression mechanism, the early automatic response activation and the post-error adjustment were not impacted by hypoxia. However, during prolonged hypoxic exposure the temporal judgments were underestimated suggesting a slowdown of the internal clock. A decrease in cortical arousal level induced by hypoxia could consistently explain both the slowdown of the internal clock and the persistence of a higher number of errors after several days of exposure. PMID:27262217

  9. Emotional attentional control predicts changes in diurnal cortisol secretion following exposure to a prolonged psychosocial stressor.

    PubMed

    Lenaert, Bert; Barry, Tom J; Schruers, Koen; Vervliet, Bram; Hermans, Dirk

    2016-01-01

    Hypothalamic-pituitary-adrenal (HPA) axis irregularities have been associated with several psychological disorders. Hence, the identification of individual difference variables that predict variations in HPA-axis activity represents an important challenge for psychiatric research. We investigated whether self-reported attentional control in emotionally demanding situations prospectively predicted changes in diurnal salivary cortisol secretion following exposure to a prolonged psychosocial stressor. Low ability to voluntarily control attention has previously been associated with anxiety and depressive symptomatology. Attentional control was assessed using the Emotional Attentional Control Scale. In students who were preparing for academic examination, salivary cortisol was assessed before (time 1) and after (time 2) examination. Results showed that lower levels of self-reported emotional attentional control at time 1 (N=90) predicted higher absolute diurnal cortisol secretion and a slower decline in cortisol throughout the day at time 2 (N=71). Difficulty controlling attention during emotional experiences may lead to chronic HPA-axis hyperactivity after prolonged exposure to stress. These results indicate that screening for individual differences may foster prediction of HPA-axis disturbances, paving the way for targeted disorder prevention. PMID:26539967

  10. Pre-activating wounding response in tobacco prior to high-level ozone exposure prevents necrotic injury.

    PubMed

    Orvar, B L; McPherson, J; Ellis, B E

    1997-02-01

    In tobacco, both wounding and treatment with jasmonates prior to exposure of the tissue to high concentrations of ozone (250 to 500 p.p.b.) produce a dramatic decrease in ozone injury. A systemic pattern of increased ozone tolerance developed within 3-6 h after wounding and also after local application of jasmonates. Ozone treatment of transgenic (NahG) tobacco plants showed that the inability of these plants to accumulate salicylic acid is also accompanied by increased ozone tolerance. Expression of mRNA encoding the anti-oxidant enzyme ascorbate peroxidase is upregulated by ozone challenge, wounding and by methyl jasmonate exposure within 3-4 h, while levels of carbonic anhydrase mRNA are simultaneously depressed following ozone exposure and methyl jasmonate treatment. The pattern of these results shows that the response to ozone challenge in tobacco involves signalling mechanisms similar to those induced in plants by other environmental stresses that generate reactive oxygen species. PMID:9076988

  11. Generation of oxidative stress in human cutaneous models following in vitro ozone exposure.

    PubMed

    Cotovio, J; Onno, L; Justine, P; Lamure, S; Catroux, P

    2001-01-01

    Ozone, one of the main components of photochemical smog, represents an important source of environmental oxidative stress. The skin, being the outermost barrier of the body, is directly exposed to environmental oxidant toxicants. Skin sebum and cellular plasma membrane lipids contain polyunsaturated fatty acids which are primary targets for ozone and free radical attack induced lipid peroxides. These ozonation processes in skin can also generate aldehydes, hydroxyhydroperoxides and specific Criegee's ozonides. In order to evaluate in vitro human skin susceptibility to ozone, we have exposed cultured immortalized human keratinocytes (DK7-NR) and the reconstructed human epidermis Episkin to 10 ppm of ozone in a specific incubator. We measured the formation of protein carbonyls by an ELISA method and monitored the oxidative stress using the fluorogenic probe 2',7'-dichlorofluorescin-diacetate (DCFH-DA). Results showed a time-dependent increase of fluorescence levels (linked to oxidative stress) in both models exposed to ozone. Using this protocol, we investigated the protective potential of different products including vitamin C, a thiol derivative and a plant extract. All products dramatically reduced oxidative responses during ozone exposure. Decreases observed in fluorescence levels were between 60 and 90% as compared to non-protected controls. These results demonstrate: (a) cutaneous in vitro models are remarkably susceptible to oxidative stress generated by an environmental air pollutant as ozone, and (b) raw antioxidants, thiols and vitamin C were efficient products to prevent ozone induced cellular oxidative damage. PMID:11566563

  12. Nonspecific bronchial responsiveness assessed in vitro following acute inhalation exposure to ozone and ozone/sulfuric acid mixtures

    SciTech Connect

    El-Fawal, H.A.N.; McGovern, T.; Schlesinger, R.B.

    1995-01-01

    Air pollution may play some role in the recent increase in severity and prevalence of asthma, but the specific chemical components with the ambient pollutant mix that may be responsible have not been delineated. Since ambient exposures involve mixtures, it is essential to examine airway responses to realistic pollutant mixtures. This study examined the ability of single (3-h) inhalation exposures to ozone and to mixtures of ozone plus sulfuric acid to induce nonspecific airway hyperresponsiveness in healthy rabbits. Airway responsiveness was assessed using an in vitro assay involving administration of increasing doses of acetylcholine to bronchial rings obtained from animals exposed to 0.1-0.6 ppm ozone or to mixtures of ozone and 50-125 {mu}g/m{sup 3} sulfuric acid aerosol; results were compared to those reported previously for sulfuric acid alone. Bronchial hyperresponsiveness in healthy animals and suggest that interaction with sulfuric acid may reduce the effectiveness of both pollutants. 31 refs., 3 figs., 3 tabs.

  13. Response of rat tracheal epithelium to ozone and oxygen exposure in vitro

    SciTech Connect

    Nikula, K.J.; Wilson, D.W. )

    1990-07-01

    Although ozone-induced epithelial injury in vivo has been morphologically characterized, effects of gaseous oxidants on respiratory epithelium in organ culture, where tissue organization is maintained but systemic influences are eliminated, have not been thoroughly investigated. In this study, we exposed tracheal organ cultures from rats to 95% oxygen and 1 ppm ozone, alone and in combination, to determine (1) whether epithelial responses to ozone similar to those observed in vivo occur in airways separated from systemic physiologic, secretory, and inflammatory reactions; (2) whether concentrations of oxygen sufficient to potentially cause oxidant injury result in morphologic epithelial alterations similar to those that occur in ozone toxicity; and (3) if the combined oxidant insult of oxygen and ozone results in more severe damage to the tracheal epithelium than occurs with ozone in air. Tracheal organ cultures were exposed to filtered air and 5% carbon dioxide; filtered air, 5% carbon dioxide, and 1 ppm ozone; 95% oxygen and 5% carbon dioxide; or 95% oxygen, 5% carbon dioxide, and 1 ppm ozone for 96 hr. Light- and quantitative electron-microscopic evaluation showed that epithelia exposed to 1 ppm ozone in air exhibited loss of ciliated cells and ciliated cell damage. The epithelia exposed to 95% oxygen and 5% carbon dioxide were pseudostratified, columnar, ciliated, and hyperplastic. Epithelia exposed to 95% oxygen plus 1 ppm ozone were stratified and nonciliated or very sparsely ciliated. The predominant cell types in epithelia exposed to oxygen plus ozone were serous cells and metaplastic cells, and focal aggregates of adherent necrotic cells were present. We conclude that there was a synergism between oxygen and ozone exposure leading to enhanced epithelial injury and metaplasia.

  14. The physiological consequences of varied heat exposure events in adult Myzus persicae: a single prolonged exposure compared to repeated shorter exposures

    PubMed Central

    Andrew, Nigel R.

    2016-01-01

    The study of environmental stress tolerance in aphids has primarily been at low temperatures. In these cases, and in the rare cases of high temperature tolerance assessments, all exposures had been during a single stress event. In the present study, we examined the physiological consequences of repeated high temperature exposure with recovery periods between these stress events in Myzus persicae. We subjected individuals to either a single prolonged three hour heating event, or three one hour heating events with a recovery time of 24 h between bouts. Aphids exposed to repeated bouts of high temperatures had more glucose and higher expression of proteins and osmolyte compounds, such as glycerol, compared to the prolonged exposure group. However, aphids exposed to the repeated high temperature treatment had reduced sources of energy such as trehalose and triglyceride compounds than the prolonged exposure group. Recovery time had more physiological costs (based on production of more protein and consumption of more trehalose and triglyceride) and benefits (based on production of more osmolytes) in repeated high temperature treatments. As aphids are known to respond differently to constant versus ‘natural’ fluctuating temperature regimes, conclusions drawn from constant temperature data sets may be problematic. We suggest future experiments assessing insect responses to thermal stress incorporate a repeated stress and recovery pattern into their methodologies. PMID:27547583

  15. The physiological consequences of varied heat exposure events in adult Myzus persicae: a single prolonged exposure compared to repeated shorter exposures.

    PubMed

    Ghaedi, Behnaz; Andrew, Nigel R

    2016-01-01

    The study of environmental stress tolerance in aphids has primarily been at low temperatures. In these cases, and in the rare cases of high temperature tolerance assessments, all exposures had been during a single stress event. In the present study, we examined the physiological consequences of repeated high temperature exposure with recovery periods between these stress events in Myzus persicae. We subjected individuals to either a single prolonged three hour heating event, or three one hour heating events with a recovery time of 24 h between bouts. Aphids exposed to repeated bouts of high temperatures had more glucose and higher expression of proteins and osmolyte compounds, such as glycerol, compared to the prolonged exposure group. However, aphids exposed to the repeated high temperature treatment had reduced sources of energy such as trehalose and triglyceride compounds than the prolonged exposure group. Recovery time had more physiological costs (based on production of more protein and consumption of more trehalose and triglyceride) and benefits (based on production of more osmolytes) in repeated high temperature treatments. As aphids are known to respond differently to constant versus 'natural' fluctuating temperature regimes, conclusions drawn from constant temperature data sets may be problematic. We suggest future experiments assessing insect responses to thermal stress incorporate a repeated stress and recovery pattern into their methodologies. PMID:27547583

  16. Prolonged exposure to arsenic in UK private water supplies: toenail, hair and drinking water concentrations.

    PubMed

    Middleton, D R S; Watts, M J; Hamilton, E M; Fletcher, T; Leonardi, G S; Close, R M; Exley, K S; Crabbe, H; Polya, D A

    2016-05-18

    Chronic exposure to arsenic (As) in drinking water is an established cause of cancer and other adverse health effects. Arsenic concentrations >10 μg L(-1) were previously measured in 5% of private water supplies (PWS) in Cornwall, UK. The present study investigated prolongued exposure to As by measuring biomarkers in hair and toenail samples from 212 volunteers and repeated measurements of As in drinking water from 127 households served by PWS. Strong positive Pearson correlations (rp = 0.95) indicated stability of water As concentrations over the time period investigated (up to 31 months). Drinking water As concentrations were positively correlated with toenail (rp = 0.53) and hair (rp = 0.38) As concentrations - indicative of prolonged exposure. Analysis of washing procedure solutions provided strong evidence of the effective removal of exogenous As from toenail samples. Significantly higher As concentrations were measured in hair samples from males and smokers and As concentrations in toenails were negatively associated with age. A positive association between seafood consumption and toenail As and a negative association between home-grown vegetable consumption and hair As was observed for volunteers exposed to <1 As μg L(-1) in drinking water. These findings have important implications regarding the interpretation of toenail and hair biomarkers. Substantial variation in biomarker As concentrations remained unaccounted for, with soil and dust exposure as possible explanations. PMID:27120003

  17. The impact of dissociation and depression on the efficacy of prolonged exposure treatment for PTSD.

    PubMed

    Hagenaars, Muriel A; van Minnen, Agnes; Hoogduin, Kees A L

    2010-01-01

    This study investigates the impact of dissociative phenomena and depression on the efficacy of prolonged exposure treatment in 71 patients with posttraumatic stress disorder (PTSD). Diagnoses, comorbidity, pretreatment depressive symptoms, PTSD symptom severity, and dissociative phenomena (trait dissociation, numbing, and depersonalization) were assessed at pretreatment using semi-structured interviews and questionnaires. In a pretreatment behavioral exposure test, patients were imaginally exposed to (part of) their trauma memory for 9 min, during which subjective fear was assessed. At posttreatment and 6 months follow-up PTSD, depressive and dissociative symptoms were again assessed in the completers (n = 60). Pretreatment levels of dissociative and depressive symptoms were similar in dropouts and completers and none of the dissociative phenomena nor depression predicted improvement. Against expectations, dissociative phenomena and depression were associated with enhanced rather than impeded fear activation during the behavioral exposure test. However, these effects disappeared after controlling for initial PTSD severity. Hence, rather than supporting contraindication, the current results imply that patients presenting with even severe dissociative or depressive symptoms may profit similarly from exposure treatment as do patients with minimal dissociative or depressive symptoms. PMID:19766987

  18. Exposure to ozone modulates human airway protease/antiprotease balance contributing to increased influenza A infection.

    PubMed

    Kesic, Matthew J; Meyer, Megan; Bauer, Rebecca; Jaspers, Ilona

    2012-01-01

    Exposure to oxidant air pollution is associated with increased respiratory morbidities and susceptibility to infections. Ozone is a commonly encountered oxidant air pollutant, yet its effects on influenza infections in humans are not known. The greater Mexico City area was the primary site for the spring 2009 influenza A H1N1 pandemic, which also coincided with high levels of environmental ozone. Proteolytic cleavage of the viral membrane protein hemagglutinin (HA) is essential for influenza virus infectivity. Recent studies suggest that HA cleavage might be cell-associated and facilitated by the type II transmembrane serine proteases (TTSPs) human airway trypsin-like protease (HAT) and transmembrane protease, serine 2 (TMPRSS2), whose activities are regulated by antiproteases, such as secretory leukocyte protease inhibitor (SLPI). Based on these observations, we sought to determine how acute exposure to ozone may modulate cellular protease/antiprotease expression and function, and to define their roles in a viral infection. We utilized our in vitro model of differentiated human nasal epithelial cells (NECs) to determine the effects of ozone on influenza cleavage, entry, and replication. We show that ozone exposure disrupts the protease/antiprotease balance within the airway liquid. We also determined that functional forms of HAT, TMPRSS2, and SLPI are secreted from human airway epithelium, and acute exposure to ozone inversely alters their expression levels. We also show that addition of antioxidants significantly reduces virus replication through the induction of SLPI. In addition, we determined that ozone-induced cleavage of the viral HA protein is not cell-associated and that secreted endogenous proteases are sufficient to activate HA leading to a significant increase in viral replication. Our data indicate that pre-exposure to ozone disrupts the protease/antiprotease balance found in the human airway, leading to increased influenza susceptibility. PMID

  19. Response of Phaseolus vulgaris L. to differing ozone regimes having identical total exposure

    NASA Astrophysics Data System (ADS)

    Musselman, Robert C.; Younglove, Theodore; McCool, Patrick M.

    Protocols were designed to test for differences in response of plants to ozone treatments having equal total exposure (concentration × time) but different exposure profiles Kidney beans ( Phaseolus vulgaris L., cv. California Dark Red) were exposed to ozone in controlled fumigation chambers within a greenhouse Four different ozone exposure profiles were used, each having the same total cumulative exposure (SUM00) and the same 7, 12 and 24 h seasonal means. The three exposure profiles which incorporated peak concentrations more severely impacted response parameters compared to a steady-state profile which did not exceed the National Ambient Air Quality Standard. Significant differences were found in percent necrotic leaf area, number of pods and top dry weight between exposure profiles. In additional analyses, the response parameters were regressed against seasonal cumulative ozone concentrations raised to powers of 0.33 and from 0.5 to 4 in steps of 0.5 in order to increase effective weighting of the higher concentrations. Total dry weight and leaf necrosis were best fit with the sum of the squared concentrations ( n = 2) while number of pods was best fit by the summed concentrations to the 3.5 power ( n = 3.5). These analyses suggest the peak ozone concentrations are important in determining plant response.

  20. Changes in thyroid function after short-term ozone exposure in rats

    SciTech Connect

    Clemons, G.K.; Garcia, J.F.

    1980-01-01

    Exposure of male rats to ozone for 24 h at 1 ppM caused a profound depression of the pituitary-thyroid axis as indicated by a highly significant reduction of circulating thyrotropin hormone (TSH), thyroid hormones (T4 and T3), and protein-bound iodine (PBI). The metabolic clearance of TSH was not altered during ozone exposure and the high TSH levels seen in thyroidectomized rats were also not affected. Circulating prolactin (PRL) levels were significantly elevated after exposure. Pituitary TSH and PRL content was considerably increased in ozone-exposed rats; however, only TSH was released significantly above control values in vitro. Thyroid weight was also significantly increased after exposure. The results suggest that the depression of the pituitary-thyroid axis may be an adaptive mechanism during ozone exposure by reducing hypothalamic stimulation via thyrotropin releasing hormone (TRH) and at the same time lifting the hypothalamic catecholamine inhibition on PRL release. Both may be necessary alterations in order to develop tolerance during ozone exposure.

  1. Ozone

    MedlinePlus

    ... Earth's surface. It shields us from the sun's ultraviolet rays. Part of the good ozone layer is ... enough good ozone, people may get too much ultraviolet radiation. This may increase the risk of skin ...

  2. Ozone

    MedlinePlus

    ... reactive form of oxygen. In the upper atmosphere, ozone forms a protective layer that shields us from the sun’s ultraviolet rays. At ground level, ozone is a harmful air pollutant and a primary ...

  3. DEVELOMENT AND EVALUATION OF A MODEL FOR ESTIMATING LONG-TERM AVERAGE OZONE EXPOSURES TO CHILDREN

    EPA Science Inventory

    Long-term average exposures of school-age children can be modelled using longitudinal measurements collected during the Harvard Southern California Chronic Ozone Exposure Study over a 12-month period: June, 1995-May, 1996. The data base contains over 200 young children with perso...

  4. MEASUREMENTS OF CARDIOPULMONARY RESPONSE IN AWAKE RATS DURING ACUTE EXPOSURE TO NEAR AMBIENT CONCENTRATIONS OF OZONE

    EPA Science Inventory

    Although rodents are the most commonly studied animal species for ozone (O3) research, no acute cardiopulmonary function studies during exposure have been reported. wake Fischer-344 rats were exposed to )3 and response was evaluated before, during and after the exposure using a p...

  5. Duration of increased pulmonary function sensitivity to an initial ozone exposure

    SciTech Connect

    Bedi, J.F.; Drechsler-Parks, D.M.; Horvath, S.M.

    1985-12-01

    The metabolic and pulmonary function effects were investigated in six non-smoking young adults who were exposed for 2 hours (22 degrees C WBGT) to: filtered air (FA) 0.45 ppm ozone (DAY1); and two days later to a second exposure to 0.45 ppm ozone (DAY2). The subjects alternated 20-minute periods of rest and 20-minute periods of bicycle ergometer exercise at a workload predetermined to elicit a ventilatory minute volume (VE) of 27 L/min (BTPS). Functional residual capacity (FRC) was determined pre- and post-exposure. Forced vital capacity (FVC) was determined before and after exposure, as well as 5 minutes after each exercise period. Heart rate was monitored throughout the exposure, and VE, oxygen uptake (VO2), respiratory rate (fR), and tidal volume (VT) were measured during the last 2 minutes of each exercise period. There were no changes in any variable consequent to FA exposure. Both ozone exposures induced significant (P less than 0.05) decrements in FVC; FEV1.0 (forced expiratory volume in 1 second); FEV3.0 (forced expiratory volume in 3 seconds); FEF25-75% (average flow rate between 25% and 75% of FVC); and total lung capacity (TLC). The decrements following the DAY2 ozone exposure were significantly greater than following DAY1, and averaged 7.2 percentage points greater than those following the DAY1 exposure.

  6. OZONE-INDUCED RESPIRATORY SYMPTOMS: EXPOSURE-RESPONSE MODELS AND ASSOCIATION WITH LUNG FUNCTION

    EPA Science Inventory

    Ozone-induced respiratory symptoms are known to be functions of concentration, minute ventilation, and duration of exposure. The purposes of this study were to identify an exposure-response model for symptoms, to determine whether response was related to age, and to assess the re...

  7. Ozone

    MedlinePlus

    Ozone is a gas. It can be good or bad, depending on where it is. "Good" ozone occurs naturally about 10 to 30 miles above ... the sun's ultraviolet rays. Part of the good ozone layer is gone. Man-made chemicals have destroyed ...

  8. Long-term behavioral effects in a rat model of prolonged postnatal morphine exposure.

    PubMed

    Craig, Michael M; Bajic, Dusica

    2015-10-01

    Prolonged morphine treatment in neonatal pediatric populations is associated with a high incidence of opioid tolerance and dependence. Despite the clinical relevance of this problem, our knowledge of long-term consequences is sparse. The main objective of this study was to investigate whether prolonged morphine administration in a neonatal rat is associated with long-term behavioral changes in adulthood. Newborn animals received either morphine (10 mg/kg) or equal volume of saline subcutaneously twice daily for the first 2 weeks of life. Morphine-treated animals underwent 10 days of morphine weaning to reduce the potential for observable physical signs of withdrawal. Animals were subjected to nonstressful testing (locomotor activity recording and a novel-object recognition test) at a young age (Postnatal Days [PDs] 27-31) or later in adulthood (PDs 55-56), as well as stressful testing (calibrated forceps test, hot plate test, and forced swim test) only in adulthood. Analysis revealed that prolonged neonatal morphine exposure resulted in decreased thermal but not mechanical threshold. Importantly, no differences were found for total locomotor activity (proxy of drug reward/reinforcement behavior), individual forced swim test behaviors (proxy of affective processing), or novel-object recognition test. Performance on the novel-object recognition test was compromised in the morphine-treated group at the young age, but the effect disappeared in adulthood. These novel results provide insight into the long-term consequences of opioid treatment during an early developmental period and suggest long-term neuroplastic differences in sensory processing related to thermal stimuli. PMID:26214209

  9. An Adaptation of Prolonged Exposure Therapy for Pediatric Single Incident Trauma: A Case Series

    PubMed Central

    Adler Nevo, Gili; Manassis, Katharina

    2011-01-01

    Objective: To assess the efficacy of a modification for Prolonged Exposure (PE) therapy for single incident trauma in youth and examine the effective component(s) of treatment. Method: Fifteen youth (2 boys, 13 girls; mean age= 10.8 years) were treated with a developmentally modified version of PE called Trauma Mastery Therapy (TMT). The youth were evaluated pre-treatment, every 2 treatment sessions, and at 1 month follow-up. Primary outcome measure: the Child PTSD Symptom Scale (CPSS), a self administered PTSD questionnaire. Results: Post-treatment, 13 participants did not meet criteria for PTSD. Patients showed significant improvement at post-treatment. Analysis of variance models with pair-wise contrasts showed significantly higher scores at initiation of treatment as compared to the end of the exposure phase and, to a lesser extent, as compared to the psychoeducational phase, but no further significant improvement following the relapse prevention or follow-up phases. Conclusions: TMT appears to be a promising treatment for single incident trauma in youth. Flexibility within the structure of TMT may facilitate treatment success. The study suggests exposure, and to some extent, psychoeducation, to be important components of treatment. Additional research is required to further validate these initial findings. PMID:21541102

  10. Prolonged exposure of the HIV-1 gp41 membrane proximal region with L669S substitution

    PubMed Central

    Shen, Xiaoying; Dennison, S. Moses; Liu, Pinghuang; Gao, Feng; Jaeger, Frederick; Montefiori, David C.; Verkoczy, Laurent; Haynes, Barton F.; Alam, S. Munir; Tomaras, Georgia D.

    2010-01-01

    The conserved membrane-proximal external region (MPER) of HIV-1 envelope is a target for the rare broadly neutralizing 2F5, Z13, and 4E10 monoclonal antibodies (mAbs). One strategy to elicit such antibodies is to design an immunogen with increased exposure of the 2F5 and 4E10 mAb epitopes. In this study we characterize a single leucine to serine substitution at position 669 (L669S) in the gp41 Env MPER that confers >250-fold more neutralization sensitivity to 2F5 and 4E10 mAbs than does the wild-type gp41 sequence. On synthetic liposomes, increased solvent exposure of MPER tryptophan residues and stable docking of 2F5 and 4E10 mAbs to mutant MPER peptide liposomes indicate more favorable membrane orientation of MPER neutralizing epitopes with L669S substitution. The time during which virus is sensitive to 2F5 mAb-mediated neutralization is approximately 3-fold longer when the mutation is present. These data suggest that a major contribution to the L669S mutant virus phenotype of enhanced susceptibility to MPER mAbs is prolonged exposure of the MPER neutralizing epitope during viral entry. PMID:20231447

  11. Changes in Temporal Attention Inhibition Following Prolonged Exposure and Sertraline in the Treatment of PTSD

    PubMed Central

    Echiverri-Cohen, Aileen; Zoellner, Lori A.; Gallop, Robert; Feeny, Norah; Jaeger, Jeffrey; Bedard-Gilligan, Michele

    2016-01-01

    Objective Attentional inhibitory deficits expressed as difficulty ignoring irrelevant stimuli in the pursuit of goal-directed behavior may serve as a fundamental mechanism of posttraumatic stress disorder (PTSD). Evidence of inhibitory processes as central to extinction suggests that exposure-based treatments may act more directly on the inhibitory deficits implicated in PTSD, whereas, in facilitating serotonergic neurotransmission, selective serotonin reuptake inhibitors (SSRIs) may be less direct and bring about general neurochemical changes in the fear circuitry. If these inhibitory deficits underlie PTSD, then inhibition should improve with successful treatment, with those treated with prolonged exposure (PE) potentially resulting in greater changes in inhibition than those treated with sertraline. Method Changes in temporal attentional inhibition, using an attentional blink (AB) paradigm, were examined at pre-and post-treatment in 49 individuals (74.5% female, 66.7% Caucasian, age M = 37.69, SD = 12.8 years) with chronic PTSD. Participants completed 10 weeks of either PE or sertraline. Results Individuals who made greater improvements with PE showed faster improvements in temporal inhibition on the critical inhibitory lag of AB than those who made greater improvements with sertraline (d = 0.94). These changes could not be accounted for by basic attention. Conclusions Greater improvement in fundamental attentional inhibitory processes with better treatment response to PE, compared to sertraline, suggests potential specificity in how PTSD treatments normalize inhibitory processes, such that exposure-based treatments like PE may target inhibitory processes and improve basic inhibitory functioning. Public Health Significance Statement Inhibitory processes, particularly related to temporal attention, may play a critical role in response to exposure therapy for PTSD. The main finding that individuals with PTSD who made more clinical improvement showed faster

  12. Prolonged exposure therapy for chronic combat-related PTSD: a case report of five veterans.

    PubMed

    Nacasch, Nitsa; Foa, Edna B; Fostick, Leah; Polliack, Miki; Dinstein, Yula; Tzur, Dana; Levy, Pnina; Zohar, Joseph

    2007-09-01

    Prolonged exposure (PE) therapy has been found efficient in reducing posttraumatic stress disorder (PTSD) symptoms mostly among rape victims, but has not been explored in combat-related PTSD. Five patients with severe chronic PTSD, unresponsive to previous treatment (medication and supportive therapy) are described. Patients were evaluated with the PTSD Symptom Scale-Interview, and Beck Depression Inventory, before and after 10-15 sessions of PE therapy. All five patients showed marked improvement with PE, with a mean decrease of 48% in PTSD Symptom Scale-Interview score and 69% in Beck Depression Inventory score. Moreover, four patients maintained treatment gains or kept improving 6-18 months after the treatment. The results suggest that PE was effective in reducing combat-related chronic PTSD symptoms. PMID:17805215

  13. Experimental chronic obstructive lung disease. I. Bronchopulmonary changes induced in rabbits by prolonged exposure to formaldehyde.

    PubMed

    Ionescu, J; Marinescu, D; Tapu, V; Eskenasy, A

    1978-01-01

    The prolonged exposure to formaldehyde induces in the rabbit lung reactional and dystrophic changes involving the intrapulmonary bronchi, the bronchioli and the lung tissue. These changes are represented by bronchial cell hyperplasia with hypermucigenesis, extrusion of bronchial cells, bronchiolar hypermucigenesis, parcellary squamous metaplasia or necrobiosis of epithelia, thickening of bronchial and bronchiolar walls by subepithelial cell accumulations, destruction of musculo-elastic structures with stenosis or ectasia; the vascular reactions are hyperhaemic and proliferative with an obstructive and fibrous tendency; the parenchymal lesions are atelectasias, intralobular emphysema, and cellular thickening of alveolar walls and interlobular areas. The acid phosphatase, Tween-60-esterase, naphthol-AS-D-acetate-esterase, proline-oxidase and hydroxyproline-2-epimerase activities are increasing, while the leucyl-aminopeptidase and beta-glucuronidase ones are decreasing. The qualitative observations are completed and sustained by quanitative studies of mucous cell kinetics, of cell accumulations and differentiations. PMID:151223

  14. A Pilot Study of Prolonged Exposure Therapy for Posttraumatic Stress Disorder Delivered via Telehealth Technology

    PubMed Central

    Tuerk, Peter W.; Yoder, Matthew; Ruggiero, Kenneth J; Gros, Daniel F.; Acierno, Ron

    2015-01-01

    We present a pilot study of 12 veterans diagnosed with combat-related PTSD and treated with prolonged exposure therapy (PE) via telehealth technology. A reference sample of 35 combat veterans treated with in-person PE in the same clinic is also included for a comparison. Feasibility and clinical outcomes of interest include: technical performance and practicality of the telehealth equipment, patient safety, treatment completion rates, number of sessions required for termination, and clinical outcomes. Results indicated large statistically significant decreases in self-reported pathology for veterans treated with PE via telehealth technology. Preliminary results support the feasibility and safety of the modality. Suggestions for the implementation of PE via telehealth technology are discussed. PMID:20135675

  15. Prolonged hypothermia exposure diminishes neuroprotection for severe ischemic-hypoxic primary neurons.

    PubMed

    Gao, Xiao-Ya; Zhu, Shu-Zhen; Xiang, Wei; Huang, Kai-Bin; Hu, Ya-Fang; Gu, Yong; Pan, Su-Yue

    2016-04-01

    This study aimed to identify optimal mild hypothermic (MH) condition that would provide the best protection for neuronal cells undergoing severe ischemia and hypoxia. We also sought to determine if longer exposure to mild hypothermia would confer greater protection to severe ischemia and hypoxia in these cells. We designed a primary neuronal cell model for severe glucose and oxygen deprivation/reoxygenation (OGD/R) to simulate the hypoxic-ischemic condition of patients with severe stroke, trauma, or hypoxic-ischemic encephalopathy. We evaluated the viability of these neurons following 3 h of OGD/R and variable MH conditions including different temperatures and durations of OGD/R exposure. We further explored the effects of the optimal MH condition on several parts which are associated with mitochondrial apoptosis pathway: intracellular calcium, reactive oxygen species (ROS), and mitochondrial transmembrane potential (MTP). The results of this study showed that the apoptosis proportion (AP) and cell viability proportion (CVP) after OGD/R significantly varied depending on which MH condition cells were exposed to (p < 0.001). Further, our findings showed that prolonged MH reduced the neuroprotection to AP and CVP. We also determined that the optimal MH conditions (34 °C for 4.5 h) reduced intracellular calcium, ROS, and recovered MTP. These findings indicate that there is an optimal MH treatment strategy for severely hypoxia-ischemic neurons, prolonged duration might diminish the neuroprotection, and that MH treatment likely initiates neuroprotection by inhibiting the mitochondrial apoptosis pathway. PMID:26802735

  16. Evaluation of the use of empirical ambient ozone pollutant modeling and subject activity logs as an indirect measurement of ozone exposure

    SciTech Connect

    Hopkins, L.P.; Fraser, M.P.; Ensor, K.B.; Rifai, H.S.

    1998-12-31

    The personal ozone exposure of women on the track team at Rice University was monitored using Harvard passive samplers over a period of six weeks during August and September of 1997. Each subject logged their location and activity in and around campus during the exposure period. A three-dimensional kriging model of ozone was developed to estimate the ozone exposure for each subject from ambient fixed site monitoring data. The ozone predictions from the model were combined with the activity and location information, adjusted for indoor environment when applicable, to estimate personal exposure concentrations for each subject. Using two independent approaches, the kriging model was proven to provide accurate spatial and temporal estimates of ozone at subject exposure points. The results from this work show that the method developed to estimate exposure through kriging over (x,y,t) to predict ozone concentrations at exposure points combined with subject activity/time logs produces exposure estimates within the error bounds of the analytical methods for personal monitoring.

  17. The action spectrum for vitamin D3: initial skin reaction and prolonged exposure.

    PubMed

    van Dijk, Arjan; den Outer, Peter; van Kranen, Henk; Slaper, Harry

    2016-07-01

    Vitamin D3 photosynthesis in the skin is formulated as a set of reaction equations, including side-reactions to lumisterol, tachysterol and toxisterols, and the accompanying reverse reactions, isomerisation of previtamin D3 to vitamin D3 and photodegradation of vitamin D3. The solution of this set is given for the stationary irradiance spectrum. The effective action spectrum for the instantaneous vitamin D3 production changes shape as a function of exposure, and therefore, no single action spectrum can be used. We assessed the action spectrum for unexposed skin and for skin that has been exposed to 7.5 Standard Erythemal Doses (SED). We constructed two new estimates: (1) the RIVM action spectrum, based on absorption spectra, quantum yields and skin transmission spectra, and (2) the modified QUT action spectrum, which is adjusted for self-absorption and skin transmission. For previously unexposed skin, the modified QUT action spectrum gives a qualitatively similar, but larger estimate than the RIVM action spectrum. We have not been able to solve the lack of quantitative agreement between the vitamin D production estimates from the three action spectrum estimates (RIVM, modified QUT and CIE). All new action spectra have stronger emphasis on the short wavelengths than the CIE action spectrum. We showed that, for wavelengths larger than 300 nm, the bandwidth that was used in the experiment that formed the basis of the CIE action spectrum, gives a red-shift of about 1 nm. Generally, with the formation of previtamin D3, the return reaction to provitamin D3 limits the production of vitamin D3. After some exposure, the new action spectrum has negative values for the longer wavelengths in the UVB. For the RIVM action spectrum, this happens after 7.5 SED, for the modified QUT action spectrum already after 1.25 SED, and after 7.5 SED the net production rate is largely cancelled. Thus prolonged exposure of previously unexposed skin saturates vitamin D3 formation. For maximum

  18. U.S. EPA'S OZONE EPIDEMIOLOGY RESEARCH PROGRAM: A STRATEGY FOR ASSESSING THE EFFECTS OF AMBIENT OZONE EXPOSURE UPON MORBIDITY IN EXPOSED POPULATIONS

    EPA Science Inventory

    The Clean Air Act Amendments of 1990 mandate a future reduction of ambient ozone levels in many areas of the country, the cost of which will be great. n order to assess the current public health burden of ambient ozone exposure and to provide information for assessment of potenti...

  19. Passive samplers for ambient ozone, formaldehyde and sulfur dioxide: Indoor, outdoor, and personal exposure applications

    SciTech Connect

    Grosjean, D.; Grosjean, E.

    1994-12-31

    Time-integrated measurements of air pollutants have many applications in the context of regulations pertaining to indoor air quality, outdoor (ambient) monitoring, and personal exposure assessment. For several years, the passive samplers developed at DGA have been applied to cost-effective measurements of parts per billion levels of ozone, formaldehyde and sulfur dioxide. Examples of applications will be described. These include (a) formaldehyde measurements in indoor settings including museums, public buildings and personal exposure; (b) ozone measurements indoor (museums, cultural heritage buildings) and outdoor (Class 1 Wilderness areas; air quality surveys in Europe, Canada and Latin America, long-term monitoring of ozone exposure in forests) and (c) surveys of ambient levels of sulfur dioxide in several eastern European countries.

  20. In vitro ozone exposure inhibits mitogen-induced lymphocyte proliferation and IL-2 production

    SciTech Connect

    Becker, S.; Jordan, R.L.; Orlando, G.S.; Koren, H.S.

    1989-01-01

    Human blood mononuclear cells were exposed to ozone in vitro and thereafter analyzed for competence in mitogen-induced proliferation as well as IL-1 and IL-2 production. Proliferative responses induced by phytohemagglutinin (PHA), concanavalin A (Con A), and pokeweed mitogen (PWM) were all depressed in lymphocytes exposed to an ozone concentration of 1 ppm for 4-6 h. The response to PWM was most sensitive to the ozone effect (38% suppression); responses to Con A and PHA were suppressed to a lesser extent, 23% and 18%, respectively, and were not significantly different from each other. PWM responses were affected at an ozone concentration as low as 0.1 ppm; however, no suppression of Con A-induced proliferation was seen below 0.18 ppm or of PHA-induced proliferation below 0.5 ppm. When lymphocytes and monocytes were exposed separately to ozone and then mixed back with control air-exposed monocytes or lymphocytes, both cell types appeared to be affected and the functional defects caused by the pollutant were additive. Monocyte IL-1 production induced by endotoxin was not affected by ozone exposure, while surface expression of HLA-DR on exposed monocytes was reduced by 40% 24 h after exposure. Moreover, lymphocytes exposed to ozone produced 46% less IL-2 while expressing similar surface density of IL-2 receptors. Taken together, these results show that exposure to ozone has distinct adverse effects on lymphocytes and monocytes, both of which are important in local immune defenses in the lung.

  1. Effects of ozone exposure on the xerophilic fungus, Eurotium amstelodami IS-SAB-01, isolated from naan bread.

    PubMed

    Antony-Babu, Sanjay; Singleton, Ian

    2011-01-01

    Xerophilic moulds cause contamination and spoilage of low moisture foods. This study examined the effect of ozone fumigation on growth of a Eurotium species isolated from naan bread. Two ozone treatments were used - a low-level long-term exposure (0.4 μmol/mol for 21 days) and high-level short-term exposure (300 μmol/mol for 5 to 120 min). For the low level exposure the combination of different media sucrose concentrations (0, 5, 10 and 20% w/v) with ozone treatment was also assessed. The growth of the isolate was found to be sensitive to low-level ozone fumigation depending on the media sucrose concentration and duration of the exposure. Low-level ozone exposure significantly (p<0.05) reduced the number of asexual spores formed in media with no added sucrose, an effect not observed in media with higher sucrose levels. Electron microscope observations of colonies indicated that ozone exposed cultures produced lower numbers of cleistothecia. High-level ozone exposure for short durations reduced spore viability although 100% reduction in viability was achieved only after 120 min exposure. This work demonstrates that ozone may be used to reduce spore production in Eurotium but that the ozone effect can be mediated by sucrose levels in the growth medium. PMID:21093088

  2. DOES CHRONIC OZONE EXPOSURE LEAD TO LUNG DISEASE?

    EPA Science Inventory

    The potential role of ozone in the induction of chronic lung diseases remains unclear. sing an ambient profile adopted from aerometric data from the Southwest Air Basin, rats were exposed to O3 for up to 18 months before assessments of pulmonary structure, function and biochemist...

  3. IMMUNOSUPPRESSION OF PULMONARY NATURAL KILLER ACTIVITY BY EXPOSURE TO OZONE

    EPA Science Inventory

    Ozone is an oxidant gas and an ubiquitous oxidant air pollutant with the potential to adversely affect pulmonary immune function with a consequent increase in disease susceptibility. ulmonary atural killer (NK) activity was measured in order to assess the pulmonary immunotoxicity...

  4. Respiratory responses of subjects with allergic rhinitis to ozone exposure and their relationship to nonspecific airway reactivity

    SciTech Connect

    McDonnell, W.F.; Horstman, D.H.; Abdul-Salaam, S.; Raggio, L.J.; Green, J.A.

    1987-01-01

    Ozone exposure in man produces changes in respiratory function and symptoms. There is a large degree of unexplained intersubject variability in the magnitude of these responses. There is concern that individuals with chronic respiratory diseases may also be more responsive to ozone than normal individuals. The purpose of this study was to describe the responses of subjects with allergic rhinitis to ozone exposure and to compare these responses to those previously observed in normal individuals. A further purpose was to measure the association between baseline nonspecific airway reactivity and changes in lung function and respiratory symptoms following ozone exposure.

  5. Prolonged increased responsiveness of canine peripheral airways after exposure to O/sub 3/

    SciTech Connect

    Beckett, W.S.; Freed, A.N.; Turner, C.; Menkes, H.A.

    1988-02-01

    Because it is relatively insoluble, the oxidant gas O3 may penetrate to small peripheral airways when it is inhaled. Increased responsiveness in large airways after O3 breathing has been associated with the presence of inflammatory cells. To determine whether O3 produces prolonged hyperresponsiveness of small airways associated with the presence of inflammatory cells, we exposed the peripheral lungs of anesthetized dogs to 1.0 ppm O3 for 2 h using a wedged bronchoscope technique. A contralateral sublobar segment was simultaneously exposed to air as a control. In the O3-exposed segments, collateral resistance (Rcs) was increased within 15 min and remained elevated approximately 150% throughout the 2-h exposure period. Fifteen hours later, the base-line Rcs of the O3-exposed sublobar segments was significantly elevated, and these segments demonstrated increased responsiveness to aerosolized acetylcholine (100 and 500 micrograms/ml). There were no differences in neutrophils, mononuclear cells, or mast cells (numbers or degree of mast cell degranulation) between O3 and air-exposed airways at 15 h. The small airways of the lung periphery thus are capable of remaining hyperresponsive hours after cessation of localized exposure to O3, but this does not appear to be dependent on the presence of inflammatory cells in the small airway wall.

  6. Prolonged exposure of cholestatic rats to complete dark inhibits biliary hyperplasia and liver fibrosis.

    PubMed

    Han, Yuyan; Onori, Paolo; Meng, Fanyin; DeMorrow, Sharon; Venter, Julie; Francis, Heather; Franchitto, Antonio; Ray, Debolina; Kennedy, Lindsey; Greene, John; Renzi, Anastasia; Mancinelli, Romina; Gaudio, Eugenio; Glaser, Shannon; Alpini, Gianfranco

    2014-11-01

    Biliary hyperplasia and liver fibrosis are common features in cholestatic liver disease. Melatonin is synthesized by the pineal gland as well as the liver. Melatonin inhibits biliary hyperplasia of bile duct-ligated (BDL) rats. Since melatonin synthesis (by the enzyme serotonin N-acetyltransferase, AANAT) from the pineal gland increases after dark exposure, we hypothesized that biliary hyperplasia and liver fibrosis are diminished by continuous darkness via increased melatonin synthesis from the pineal gland. Normal or BDL rats (immediately after surgery) were housed with light-dark cycles or complete dark for 1 wk before evaluation of 1) the expression of AANAT in the pineal gland and melatonin levels in pineal gland tissue supernatants and serum; 2) biliary proliferation and intrahepatic bile duct mass, liver histology, and serum chemistry; 3) secretin-stimulated ductal secretion (functional index of biliary growth); 4) collagen deposition, liver fibrosis markers in liver sections, total liver, and cholangiocytes; and 5) expression of clock genes in cholangiocytes. In BDL rats exposed to dark there was 1) enhanced AANAT expression/melatonin secretion in pineal gland and melatonin serum levels; 2) improved liver morphology, serum chemistry and decreased biliary proliferation and secretin-stimulated choleresis; and 4) decreased fibrosis and expression of fibrosis markers in liver sections, total liver and cholangiocytes and reduced biliary expression of the clock genes PER1, BMAL1, CLOCK, and Cry1. Thus prolonged dark exposure may be a beneficial noninvasive therapeutic approach for the management of biliary disorders. PMID:25214401

  7. Effect of ozone exposure on antigen-induced airway hyperresponsiveness in guinea pigs

    SciTech Connect

    Vargas, M.H.; Segura, P.; Campos, M.G.; Hong, E.; Montano, L.M.

    1994-12-31

    Airway hyperresponsiveness can be induced by several stimuli including antigen and ozone, both of which may be present in the air of polluted cities. Though the effect of ozone on the bronchoconstrictor response to antigen has been well described, the combined effect of these stimuli on airway hyperresponsiveness has not yet been studied. Sensitized guinea pigs with or without ozone exposure for 1 h at 3 ppm, 18 h prior to study, were challenged with a dose-response curve to histamine (0.01-1.8 {mu}g/kg, iv), and then by a second histamine dose-response curve 1 h later. Airway responses were measured as the increase in pulmonary insufflation pressure. In sensitized guinea pigs, the histamine ED50 significantly decreased after antigen challenge, demonstrating the development of airway hyperresponsiveness. Sensitized guinea pigs exposed to ozone showed airway hyperresponsiveness to histamine when compared with nonexposed animals, and such hyperresponsiveness was further enhanced after antigen challenge. We conclude that in this guinea pig model of acute allergic bronchoconstriction both antigen challenge and ozone induce airway hyperresponsiveness, while ozone exposure does not modify the development of antigen-induced hyperresponsiveness. 25 refs., 1 fig., 1 tab.

  8. Exposure to ozone reduces postharvest quality loss in red and green chilli peppers.

    PubMed

    Glowacz, Marcin; Rees, Deborah

    2016-11-01

    The effect of continuous exposure to ozone at 0.45, 0.9 and 2μmolmol(-1) on quality changes during the storage of red and green chilli peppers at 10°C was investigated. Ozone at 0.45 and 0.9μmolmol(-1) reduced disease incidence in red peppers, with no further benefits at 2μmolmol(-1). Ozone at 0.9μmolmol(-1) reduced weight loss during storage and improved firmness maintenance. Skin colour was bleached in red peppers exposed to ozone at 2μmolmol(-1), and in green ones at all tested doses. Total phenolic content was not affected by ozone but antioxidant activity was reduced in green chilli peppers exposed to ozone at 2μmolmol(-1), due to lower ascorbic acid content in those samples. Ozone at 0.9μmolmol(-1) extended the shelf-life of chilli peppers. PMID:27211651

  9. Relationships between ozone exposure and yield loss in European wheat and potato—a comparison of concentration- and flux-based exposure indices

    NASA Astrophysics Data System (ADS)

    Pleijel, H.; Danielsson, H.; Ojanperä, K.; Temmerman, L. De; Högy, P.; Badiani, M.; Karlsson, P. E.

    Data from open-top chamber experiments with field grown crops, performed in Sweden, Finland, Belgium, Italy and Germany, were combined to derive relationships between yield and ozone exposure for wheat ( Triticum aestivum L.) and potato ( Solanum tuberosum L.). Three different exposure indices were compared: AOT40 (accumulated exposure over a threshold ozone concentration of 40 nmol mol -1), CUO t (cumulative stomatal uptake of ozone, using a constant ozone uptake rate threshold of t nmol m -2 s -1) and mAOT c0 (conductance modified AOT using a threshold concentration for ozone of c0 nmol mol -1). The latter is essentially a combination of AOT and CUO. Ozone uptake was estimated using a Jarvis-type multiplicative model for stomatal conductance. In terms of correlation between relative yield (RY) and ozone exposure, CUO 5, the CUO index with an ozone uptake rate threshold of 5 nmol m -2 s -1, performed best for both wheat and potato, resulting in r2 values of 0.77 and 0.64, respectively. CUO 5 performed considerably better in terms of the correlation between RY and ozone exposure, than AOT40 for wheat, while mAOT10, the best performing mAOT index in this case, was intermediate in performance for this crop. For potato, the differences between the different ozone exposure indices AOT40, CUO 5 and mAOT20 (the mAOT index performing best for potato) in the correlation between RY and ozone exposure were relatively small. To test the assumption that the non-stomatal deposition of ozone was negligible for the uppermost, sunlit leaves, measurements of ozone uptake in relation to leaf conductance for water vapor of wheat leaves in a cuvette system were used. The non-stomatal deposition of ozone to the leaves turned out to be comparatively small. Based on the non-stomatal conductance ( gns=15 mmol m -2 s -1) estimated for the wheat leaves in the cuvette system, it was concluded that the consequence of omitting the non-stomatal conductance is small. In conclusion the study

  10. Episodic ozone exposure in adult and Senescent Brown Norway rats: Acute and delayed cardiovascular and thermoregulatory responses

    EPA Science Inventory

    Setting exposure standards for environmental pollutants may consider the aged as a susceptible population but the few published studies assessing susceptibility of the aged to air pollutants are inconsistent. Episodic ozone (O(3)) is more reflective of potential exposures occurri...

  11. Ocular and dermatologic health effects of ultraviolet radiation exposure from the ozone hole in southern Chile.

    PubMed Central

    Schein, O D; Vicencio, C; Muñoz, B; Gelatt, K N; Duncan, D D; Nethercott, J; Honeyman, J; Koren, H S; West, S

    1995-01-01

    OBJECTIVES. This study sought to investigate numerous reports emanating from Punta Arenas, Chile (population 110,000, latitude 53 degrees S), that associated acute ocular and dermatologic disease in humans and animals with excess ultraviolet-B (UV-B) exposure in the setting of the thinning of the ozone column. METHODS. Ophthalmologic and dermatologic records in Punta Arenas were systematically reviewed to enumerate sentinel diagnoses potentially associated with UV-B exposure, ocular examinations on representative animal populations were performed, and the ambient UV-B exposure in the region during the time of maximal thinning was estimated. RESULTS. No increase in patient visits or conditions attributable to UV-B exposure was seen for periods of known ozone depletion compared with control periods. Although ambient UV-B exposure was 1.6 to 2.3 times the habitual exposure on individual days, this excess exposure conferred only a 1% increase in annual exposure on the region. CONCLUSION. This study does not support existing lay reports of ocular and dermatologic disease in humans and animals that had been associated with the ozone hole over southern Chile. PMID:7702120

  12. Effect of Gaseous Ozone Exposure on the Bacteria Counts and Oxidative Properties of Ground Hanwoo Beef at Refrigeration Temperature

    PubMed Central

    Cho, Youngjae; Hahn, Tae-Wook

    2014-01-01

    This study was designed to elucidate the effect of ozone exposure on the bacteria counts and oxidative properties of ground Hanwoo beef contaminated with Escherichia coli O157:H7 at refrigeration temperature. Ground beef was inoculated with 7 Log CFU/g of E. coli O157:H7 isolated from domestic pigs and was then subjected to ozone exposure (10×10−6 kg O3 h−1) at 4℃ for 3 d. E. coli O157:H7, total aerobic and anaerobic bacterial growth and oxidative properties including instrumental color changes, TBARS, catalase (CAT) and glutathione peroxidase (GPx) activity were evaluated. Ozone exposure significantly prohibited (p<0.05) the growths of E. coli O157:H7, total aerobic and anaerobic bacteria in ground beef samples during storage. Ozone exposure reduced (p<0.05) the CIE a* value of samples over storage time. The CIE L* and CIE b* values of the samples fluctuated over storage time, and ozone had no clear effect. Ozone exposure increased the TBARS values during 1 to 3 d of storage (p<0.05). The CAT and GPx enzyme activities were not affected by ozone exposure until 2 and 3 d of storage, respectively. This study provides information about the use of ozone exposure as an antimicrobial agent for meat under refrigerated storage. The results of this study provide a foundation for the further application of ozone exposure by integrating an ozone generator inside a refrigerator. Further studies regarding the ozone concentrations and exposure times are needed. PMID:26761291

  13. Effect of Gaseous Ozone Exposure on the Bacteria Counts and Oxidative Properties of Ground Hanwoo Beef at Refrigeration Temperature.

    PubMed

    Cho, Youngjae; Muhlisin; Choi, Ji Hye; Hahn, Tae-Wook; Lee, Sung Ki

    2014-01-01

    This study was designed to elucidate the effect of ozone exposure on the bacteria counts and oxidative properties of ground Hanwoo beef contaminated with Escherichia coli O157:H7 at refrigeration temperature. Ground beef was inoculated with 7 Log CFU/g of E. coli O157:H7 isolated from domestic pigs and was then subjected to ozone exposure (10×10(-6) kg O3 h(-1)) at 4℃ for 3 d. E. coli O157:H7, total aerobic and anaerobic bacterial growth and oxidative properties including instrumental color changes, TBARS, catalase (CAT) and glutathione peroxidase (GPx) activity were evaluated. Ozone exposure significantly prohibited (p<0.05) the growths of E. coli O157:H7, total aerobic and anaerobic bacteria in ground beef samples during storage. Ozone exposure reduced (p<0.05) the CIE a* value of samples over storage time. The CIE L* and CIE b* values of the samples fluctuated over storage time, and ozone had no clear effect. Ozone exposure increased the TBARS values during 1 to 3 d of storage (p<0.05). The CAT and GPx enzyme activities were not affected by ozone exposure until 2 and 3 d of storage, respectively. This study provides information about the use of ozone exposure as an antimicrobial agent for meat under refrigerated storage. The results of this study provide a foundation for the further application of ozone exposure by integrating an ozone generator inside a refrigerator. Further studies regarding the ozone concentrations and exposure times are needed. PMID:26761291

  14. Comparison of ozone exposure characteristics in forested regions near Mexico City and Los Angeles

    NASA Astrophysics Data System (ADS)

    Miller, Paul R.; de Lourdes de Bauer, María; Quevedo Nolasco, Abel; Hernández Tejeda, Tomás

    This comparison of forest exposure to ozone in the vicinity of México City and Los Angeles provides preliminary evidence of the seasonal differences in ozone concentrations. Summer concentrations near México City are not as high as those near Los Angeles because most of the precipitation and associated cloudiness occurs near México City during the months of June through September. Winter concentrations remain nearly as high as summer concentrations at México City, because in winter skies are clearer and incident sunlight remains high. Latitudinal influences on solar zenith angle and the higher altitude of the México City region both contribute to a higher actinic flux than in the Los Angeles region. The primary difference in forest exposure is that there is very little respite from adverse ozone concentrations during the entire year in the México City region. Also, the rainy summer season would likely diminish water stress and result in greater ozone uptake at the Desierto de los Leones compared to dry summer conditions in California. The closer proximity of the Desierto de los Leones monitoring site to the urban area also contributes to high winter exposures. There is some respite from exposure during the winter in the San Bernardino mountain region; however, summer concentrations are higher than near México City. The greater transport distance from the Los Angeles source region also contributes to lower winter exposures.

  15. Ozone exposure triggers insulin resistance through muscle c-Jun N-terminal kinase activation.

    PubMed

    Vella, Roxane E; Pillon, Nicolas J; Zarrouki, Bader; Croze, Marine L; Koppe, Laetitia; Guichardant, Michel; Pesenti, Sandra; Chauvin, Marie-Agnès; Rieusset, Jennifer; Géloën, Alain; Soulage, Christophe O

    2015-03-01

    A growing body of evidence suggests that exposure to traffic-related air pollution is a risk factor for type 2 diabetes. Ozone, a major photochemical pollutant in urban areas, is negatively associated with fasting glucose and insulin levels, but most aspects of this association remain to be elucidated. Using an environmentally realistic concentration (0.8 parts per million), we demonstrated that exposure of rats to ozone induced whole-body insulin resistance and oxidative stress, with associated endoplasmic reticulum (ER) stress, c-Jun N-terminal kinase (JNK) activation, and disruption of insulin signaling in skeletal muscle. Bronchoalveolar lavage fluids from ozone-treated rats reproduced this effect in C2C12 myotubes, suggesting that toxic lung mediators were responsible for the phenotype. Pretreatment with the chemical chaperone 4-phenylbutyric acid, the JNK inhibitor SP600125, or the antioxidant N-acetylcysteine alleviated insulin resistance, demonstrating that ozone sequentially triggered oxidative stress, ER stress, and JNK activation to impair insulin signaling in muscle. This study is the first to report that ozone plays a causative role in the development of insulin resistance, suggesting that it could boost the development of diabetes. We therefore provide a potential mechanism linking pollutant exposure and the increased incidence of metabolic diseases. PMID:25277399

  16. Reduction of influenza virus pathogenesis by exposure to 0.5 ppm ozone.

    PubMed

    Jakab, G J; Hmieleski, R R

    1988-01-01

    Continuous exposure to 0.5 ppm ozone during the course of murine influenza A/PR8/34 virus infection reduced the severity of the disease as quantitated by histologic (morphometric), biochemical (serum albumin in lavage fluid), and gravimetric (lung wt/dry weight ratios) parameters of lung injury. The ozone-mediated abatement of the lung injury was independent of peak pulmonary virus titers. However, determination of the sites of virus multiplication indicated that exposure to ozone resulted in a less widespread infection of the lung parenchyma. Furthermore, ozone exposure reduced the antiviral immune response as shown by reduced numbers of phenotypically quantitated T- and B-lymphocytes recovered from lung tissues and reduction of serum antibody titers. Since the pathogenesis of influenza virus infection depends on both the site of viral replication and the antiviral immune response, these studies suggest that redistribution of virus growth in murine lungs and immunosuppressive mechanisms are factors in the ozone-reduced disease severity. PMID:3361616

  17. Modulation of bronchial epithelial cell barrier function by in vitro ozone exposure.

    PubMed Central

    Yu, X Y; Takahashi, N; Croxton, T L; Spannhake, E W

    1994-01-01

    The epithelial cells lining the small, peripheral airways function as important targets for the action of inspired ozone. Loss of epithelial barrier integrity in these regions is a common element in ozone-induced airway inflammation. To investigate the direct effect of ozone on epithelial barrier function, canine bronchial epithelial (CBE) cells grown with an air interface were exposed for 3 hr to 0.2, 0.5, or 0.8 ppm ozone or to air. Mannitol flux, used as an index of paracellular permeability, increased above air controls by 461%, 774%, and 1172% at the three ozone concentrations, respectively. Transcellular electrical resistance exhibited a dose-related decrease. The immediate effect of 0.8 ppm ozone on permeability was significantly inhibited by preincubation for 48 hr in the presence of 1 ng/ml vitamin E (33%) or 1 microM vitamin A (34%). Responses to 0.5 ppm or 0.8 ppm were inhibited by pretreatment of the cells with 0.1 microM of the actin polymerizing agent phalloidin (34% and 25% inhibition, respectively). The increases in permeability induced by 0.2 and 0.5 ppm ozone were attenuated by 54% and 22%, respectively, at 18 hr after exposure, whereas that to 0.8 ppm was further enhanced by 42% at this time. The effects of ozone are modulated by the availability of antioxidants to the cells and appear to be associated with cytoskeletal dysfunction in CBE cells. The data are consistent with a loss of barrier function linked to a direct oxidative effect of ozone on individual CBE cells and indicate that the reversible or progressive nature of this effect is dose dependent. Images Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. PMID:7713019

  18. Growth response of two varieties of slash-pine seedlings to chronic ozone exposures

    SciTech Connect

    Hogsett, W.E.; Plocher, M.; Wildman, V.; Tingey, D.T.; Bennett, J.P.

    1985-01-01

    Two geographical varieties of Pinus elliottii (Engelm.) seedlings, elliottii and densa, were exposed continuously to two daily peak exposure profiles of ozone having 7-h seasonal means of 0.104 and 0.076 ppm and charcoal-filtered air over a 112-day period. The profiles represented a daily rise and decline of hourly ozone concentration. They were constructed with a daily hourly maximum, which for one profile (0.126 micro l/l) exceeded the current ozone standard daily; the standard was not exceeded for the other profile (0.094 micro l/l). Destructive harvests at 7-day intervals over the exposure period were employed to assess visible injury and to construct growth curves for stem diameter, plant height, top and root dry weight, and needle number and length.

  19. Structural and functional localization of airway effects from episodic exposure of infant monkeys to allergen and/or ozone

    SciTech Connect

    Joad, Jesse P. . E-mail: jesse.joad@ucdmc.ucdavis.edu; Kott, Kayleen S.; Bric, John M.; Peake, Janice L.; Plopper, Charles G.; Schelegle, Edward S.; Gershwin, Laurel J.; Pinkerton, Kent E.

    2006-08-01

    Both allergen and ozone exposure increase asthma symptoms and airway responsiveness in children. Little is known about how these inhalants may differentially modify airway responsiveness in large proximal as compared to small distal airways. We evaluated whether bronchi and respiratory bronchioles from infant monkeys exposed episodically to allergen and/or ozone differentially develop intrinsic hyperresponsiveness to methacholine and whether eosinophils and/or pulmonary neuroendocrine cells play a role. Infant monkeys were exposed episodically for 5 months to: (1) filtered air, (2) aerosolized house dust mite allergen, (3) ozone 0.5 ppm, or (4) house dust mite allergen + ozone. Studying the function/structure relationship of the same lung slices, we evaluated methacholine airway responsiveness and histology of bronchi and respiratory bronchioles. In bronchi, intrinsic responsiveness was increased by allergen exposure, an effect reduced by bombesin antagonist. In respiratory bronchioles, intrinsic airway responsiveness was increased by allergen + ozone exposure. Eosinophils were increased by allergen and allergen + ozone exposure in bronchi and by allergen exposure in respiratory bronchioles. In both airways, exposure to allergen + ozone resulted in fewer tissue eosinophils than did allergen exposure alone. In bronchi, but not in respiratory bronchioles, the number of eosinophils and neuroendocrine cells correlated with airway responsiveness. We conclude that episodically exposing infant monkeys to house dust mite allergen with or without ozone increased intrinsic airway responsiveness to methacholine in bronchi differently than in respiratory bronchioles. In bronchi, eosinophils and neuroendocrine cells may play a role in the development of airway hyperresponsiveness.

  20. Exposure to medium and high ambient levels of ozone causes adverse systemic inflammatory and cardiac autonomic effects.

    PubMed

    Arjomandi, Mehrdad; Wong, Hofer; Donde, Aneesh; Frelinger, Jessica; Dalton, Sarah; Ching, Wendy; Power, Karron; Balmes, John R

    2015-06-15

    Epidemiological evidence suggests that exposure to ozone increases cardiovascular morbidity. However, the specific biological mechanisms mediating ozone-associated cardiovascular effects are unknown. To determine whether short-term exposure to ambient levels of ozone causes changes in biomarkers of cardiovascular disease including heart rate variability (HRV), systemic inflammation, and coagulability, 26 subjects were exposed to 0, 100, and 200 ppb ozone in random order for 4 h with intermittent exercise. HRV was measured and blood samples were obtained immediately before (0 h), immediately after (4 h), and 20 h after (24 h) each exposure. Bronchoscopy with bronchoalveolar lavage (BAL) was performed 20 h after exposure. Regression modeling was used to examine dose-response trends between the endpoints and ozone exposure. Inhalation of ozone induced dose-dependent adverse changes in the frequency domains of HRV across exposures consistent with increased sympathetic tone [increase of (parameter estimate ± SE) 0.4 ± 0.2 and 0.3 ± 0.1 in low- to high-frequency domain HRV ratio per 100 ppb increase in ozone at 4 h and 24 h, respectively (P = 0.02 and P = 0.01)] and a dose-dependent increase in serum C-reactive protein (CRP) across exposures at 24 h [increase of 0.61 ± 0.24 mg/l in CRP per 100 ppb increase in ozone (P = 0.01)]. Changes in HRV and CRP did not correlate with ozone-induced local lung inflammatory responses (BAL granulocytes, IL-6, or IL-8), but changes in HRV and CRP were associated with each other after adjustment for age and ozone level. Inhalation of ozone causes adverse systemic inflammatory and cardiac autonomic effects that may contribute to the cardiovascular mortality associated with short-term exposure. PMID:25862833

  1. Randomized Trial of Prolonged Exposure for Posttraumatic Stress Disorder with and without Cognitive Restructuring: Outcome at Academic and Community Clinics

    ERIC Educational Resources Information Center

    Foa, Edna B.; Hembree, Elizabeth A.; Cahill, Shawn P.; Rauch, Sheila A. M.; Riggs, David S.; Feeny, Norah C.; Yadin, Elna

    2005-01-01

    Female assault survivors (N = 171) with chronic posttraumatic stress disorder (PTSD) were randomly assigned to prolonged exposure (PE) alone, PE plus cognitive restructuring (PE/CR), or wait-list (WL). Treatment, which consisted of 9-12 sessions, was conducted at an academic treatment center or at a community clinic for rape survivors. Evaluations…

  2. Integrating Dialectical Behavior Therapy and Prolonged Exposure to Treat Co-Occurring Borderline Personality Disorder and PTSD: Two Case Studies

    ERIC Educational Resources Information Center

    Harned, Melanie S.; Linehan, Marsha M.

    2008-01-01

    Despite the high rate of trauma and PTSD among individuals with borderline personality disorder (BPD), no studies have specifically evaluated the treatment of PTSD in a BPD population. These case studies illustrate the use of a protocol based on prolonged exposure therapy that can be integrated into standard dialectical behavior therapy to treat…

  3. Absence of acute ocular damage in humans after prolonged exposure to intense RF EMF.

    PubMed

    Adibzadeh, F; van Rhoon, G C; Verduijn, G M; Naus-Postema, N C; Paulides, M M

    2016-01-21

    The eye is considered to be a critical organ when determining safety standards for radio frequency (RF) radiation. Experimental data obtained using animals showed that RF heating of the eye, particularly over a specific threshold, can induce cataracts. During the treatment of cancer in the head and neck by hyperthermia, the eyes receive a considerable dose of RF radiation due to stray radiation from the prolonged (60 min) and intense exposure at 434 MHz of this region. In the current study, we verified the exposure guidelines for humans by determining the association between the electromagnetic and thermal dose in the eyes with the reported ocular effects. We performed a simulation study to retrospectively assess the specific absorption rate (SAR) and temperature increase in the eyes of 16 selected patients (encompassing a total of 74 treatment sessions) whose treatment involved high power delivery as well as a minimal distance between the tumor site and the eye. Our results show that the basic restrictions on the peak 10 g spatial-averaged SAR (10 W kg(-1)) and peak tissue temperature increase (1 °C) are exceeded by up to 10.4 and 4.6 times, on average, and by at least 6.2 and 1.8 times when considering the lower limit of the 95% confidence interval. Evaluation of the acute effects according to patients' feedback (all patients), the common toxicity criteria scores (all patients) and an ophthalmology investigation (one patient with the highest exposure) revealed no indication of any serious acute ocular effect, even though the eyes were exposed to high electromagnetic fields, leading to a high thermal dose. We also found that, although there is a strong correlation (R (2) =  0.88) between the predicted induced SAR and temperature in the eye, there are large uncertainties regarding the temperature-SAR relationship. Given this large uncertainty (129%) compared with the uncertainty of 3D temperature simulations (61%), we recommend using temperature simulations as a

  4. Absence of acute ocular damage in humans after prolonged exposure to intense RF EMF

    NASA Astrophysics Data System (ADS)

    Adibzadeh, F.; van Rhoon, G. C.; Verduijn, G. M.; Naus-Postema, N. C.; Paulides, M. M.

    2016-01-01

    The eye is considered to be a critical organ when determining safety standards for radio frequency (RF) radiation. Experimental data obtained using animals showed that RF heating of the eye, particularly over a specific threshold, can induce cataracts. During the treatment of cancer in the head and neck by hyperthermia, the eyes receive a considerable dose of RF radiation due to stray radiation from the prolonged (60 min) and intense exposure at 434 MHz of this region. In the current study, we verified the exposure guidelines for humans by determining the association between the electromagnetic and thermal dose in the eyes with the reported ocular effects. We performed a simulation study to retrospectively assess the specific absorption rate (SAR) and temperature increase in the eyes of 16 selected patients (encompassing a total of 74 treatment sessions) whose treatment involved high power delivery as well as a minimal distance between the tumor site and the eye. Our results show that the basic restrictions on the peak 10 g spatial-averaged SAR (10 W kg-1) and peak tissue temperature increase (1 °C) are exceeded by up to 10.4 and 4.6 times, on average, and by at least 6.2 and 1.8 times when considering the lower limit of the 95% confidence interval. Evaluation of the acute effects according to patients’ feedback (all patients), the common toxicity criteria scores (all patients) and an ophthalmology investigation (one patient with the highest exposure) revealed no indication of any serious acute ocular effect, even though the eyes were exposed to high electromagnetic fields, leading to a high thermal dose. We also found that, although there is a strong correlation (R 2  =  0.88) between the predicted induced SAR and temperature in the eye, there are large uncertainties regarding the temperature-SAR relationship. Given this large uncertainty (129%) compared with the uncertainty of 3D temperature simulations (61%), we recommend using temperature

  5. INFLUENCE OF EXERCISE AND HEAT STRESS ON PULMONARY FUNCTION DURING OZONE EXPOSURE

    EPA Science Inventory

    The authors studied the effects of 2-h exposure to ozone in 14 nonsmoking males under four environmental conditions. Thirty minutes of exercise at 40% Vo2max was performed from 60 to 90 min for group A and 30 to 60 min for group B. Pulmonary Function changes, determined throughou...

  6. EFFECT OF OZONE EXPOSURE ON THE DISPERSION OF INHALED AEROSOL BOLUSES IN HEALTHY HUMAN SUBJECTS

    EPA Science Inventory

    Acute exposure of humans to low levels of ozone are known to cause decreases FVC and increases sRaw. hese alterations in lung function do not, however, elucidate the potential for acute small airways responses. n this study we employed a test of aerosol dispersion to examine the ...

  7. Human Ozone (O3) Exposure Alters Serum Profile of Lipid Metabolites

    EPA Science Inventory

    HUMAN OZONE (O3) EXPOSURE ALTERS SERUM PROFILE OF LIPID METABOLITES Miller, D B.1; Kodavanti, U P.2 Karoly, E D.3; Cascio W.E2, Ghio, A J. 21. UNC-Chapel Hill, Chapel Hill, N.C., United States. 2. NHEERL, U.S. EPA, RTP, N.C., United States. 3. METABOLON INC., Durham, N.C., United...

  8. RESPONSES OF SUBJECTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE AFTER EXPOSURES TO 0.3 PPM OZONE

    EPA Science Inventory

    The authors previously reported (1982) that the respiratory mechanics of intermittently exercising persons with chronic obstructive pulmonary disease (COPD) were unaffected by a 2-h exposure to 0.2 ppm ozone. Employing a single-blind cross-over design protocol, 13 white men with ...

  9. MODULATION OF HUMAN ALVEOLAR MACROPHAGE PROPERTIES BY OZONE EXPOSURE IN VITRO

    EPA Science Inventory

    We have investigated changes in human alveolar macrophage (HAM) function after exposure in vitro to ozone (O3) (0.1-1.0 ppm for 2-4 hours). he functions studied reflect concern that 03 is detrimental to host defense mechanisms in the broncho-alveolar spaces. xposure of HAM to cau...

  10. MUCOCILIARY CLEARANCE OF INHALED PARTICLES MEASURED AT TWO HOURS FOLLOWING OZONE EXPOSURE IN HUMANS

    EPA Science Inventory

    Mucociliary transport has been shown to increase during ozone exposure. his increase may have been due to a number of factors such as stimulation of muscarinic receptors, induction of cough, or a byproduct of inflammation. e exposed 15 healthy male and female on-smoking subjects,...

  11. COMPARISON OF THE RESPONSES OF CHILDREN AND ADULTS TO ACUTE OZONE EXPOSURE

    EPA Science Inventory

    The purpose of the paper is to compare the results of two studies in which the respiratory responses of children and adults to acute ozone (O3) exposure were measured. Forty-two 18-30 year old males were exposed for 2.5 hours in a controlled environmental chamber to either 0.0 or...

  12. INHIBITION OF HUMAN NATURAL KILLER CELL ACTIVITY FOLLOWING IN VITRO EXPOSURE TO OZONE

    EPA Science Inventory

    In this study we have examined the effect of in vitro ozone exposure on human peripheral blood natural killer (NK) cell activity measured against K562 tumor cells. he data showed that NK activity was nhibited in a time dependent manner with marked suppression observed after 6 hou...

  13. TOPICAL REVIEW: Climate change, ozone depletion and the impact on ultraviolet exposure of human skin

    NASA Astrophysics Data System (ADS)

    Diffey, Brian

    2004-01-01

    For 30 years there has been concern that anthropogenic damage to the Earth's stratospheric ozone layer will lead to an increase of solar ultraviolet (UV) radiation reaching the Earth's surface, with a consequent adverse impact on human health, especially to the skin. More recently, there has been an increased awareness of the interactions between ozone depletion and climate change (global warming), which could also impact on human exposure to terrestrial UV. The most serious effect of changing UV exposure of human skin is the potential rise in incidence of skin cancers. Risk estimates of this disease associated with ozone depletion suggest that an additional peak incidence of 5000 cases of skin cancer per year in the UK would occur around the mid-part of this century. Climate change, which is predicted to lead to an increased frequency of extreme temperature events and high summer temperatures, will become more frequent in the UK. This could impact on human UV exposure by encouraging people to spend more time in the sun. Whilst future social trends remain uncertain, it is likely that over this century behaviour associated with climate change, rather than ozone depletion, will be the largest determinant of sun exposure, and consequent impact on skin cancer, of the UK population.

  14. Effects of combinations of diesel exhaust and ozone exposure on lung function in human volunteers.

    EPA Science Inventory

    Ozone (03) exposure induces changes in human lung function, typically seen as a decrease in forced expiratory volume in one sec (FEV1) and forced vital capacity (FVC). Because people are usually exposed to other ambient air pollutants simultaneously with 03, there may be interact...

  15. Climate change, ozone depletion and the impact on ultraviolet exposure of human skin.

    PubMed

    Diffey, Brian

    2004-01-01

    For 30 years there has been concern that anthropogenic damage to the Earth's stratospheric ozone layer will lead to an increase of solar ultraviolet (UV) radiation reaching the Earth's surface, with a consequent adverse impact on human health, especially to the skin. More recently, there has been an increased awareness of the interactions between ozone depletion and climate change (global warming), which could also impact on human exposure to terrestrial UV. The most serious effect of changing UV exposure of human skin is the potential rise in incidence of skin cancers. Risk estimates of this disease associated with ozone depletion suggest that an additional peak incidence of 5000 cases of skin cancer per year in the UK would occur around the mid-part of this century. Climate change, which is predicted to lead to an increased frequency of extreme temperature events and high summer temperatures, will become more frequent in the UK. This could impact on human UV exposure by encouraging people to spend more time in the sun. Whilst future social trends remain uncertain, it is likely that over this century behaviour associated with climate change, rather than ozone depletion, will be the largest determinant of sun exposure, and consequent impact on skin cancer, of the UK population. PMID:14971768

  16. Effects Of Combinations of Ozone and Diesel Exhaust Exposures On Blood, Cardiac, And Lung Endpoints

    EPA Science Inventory

    Human subjects were exposed to combinations of 300 ppb ozone (03) and 300 ug/m3 diesel exhaust (DE) to examine if synergistic effects were observed. Subjects received either filtered air (FA), 03, DE, or DE+03 on Day 1, followed by only 03 exposures on Day 2, and a follow-up on D...

  17. Exposure to ozone modulates human airway protease/antiprotease balance contributing to increased influenza A infection

    EPA Science Inventory

    Exposure to oxidant air pollution is associated with Increased respiratory morbiditses and susceptibility to Infections Ozone is a commonly encountered oxidant air pollutant, yet Its effects on influenza infections in humans are not known ‘the greater Mexico City area was the pri...

  18. THE EFFECT OF CHRONIC OZONE EXPOSURE ON THE METABOLITE CONTENT OF PONDEROSA PINE SEEDLINGS

    EPA Science Inventory

    Ponderosa Pine (Pinus ponderosa Laws.) seedlings grown in field exposure chambers and fumigated with ozone at a concentration of 200 g/cu m 6 h/day; 7 days/wk for variable periods of up to 20 weeks. Pines were harvested at 4 wk intervals to determine the levels of the metabolites...

  19. Prolonged Exposure Therapy With Veterans and Active Duty Personnel Diagnosed With PTSD and Traumatic Brain Injury.

    PubMed

    Wolf, Gregory K; Kretzmer, Tracy; Crawford, Eric; Thors, Christina; Wagner, H Ryan; Strom, Thad Q; Eftekhari, Afsoon; Klenk, Megan; Hayward, Laura; Vanderploeg, Rodney D

    2015-08-01

    The present study used archival clinical data to analyze the delivery and effectiveness of prolonged exposure (PE) and ancillary services for posttraumatic stress disorder (PTSD) among Operation Enduring Freedom, Operation Iraqi Freedom, and Operation New Dawn veterans (N = 69) with histories of mild to severe traumatic brain injury (TBI). Data from standard clinical assessments of veterans and active duty personnel treated in both inpatient and outpatient programs at 2 Department of Veteran Affairs medical centers were examined. Symptoms were assessed with self-report measures of PTSD (PTSD Checklist) and depression (Beck Depression Inventory-II) before and throughout therapy. Mixed linear models were utilized to determine the slope of reported symptoms throughout treatment, and the effects associated with fixed factors such as site, treatment setting (residential vs. outpatient), and TBI severity were examined. Results demonstrated significant decreases in PTSD, B = -3.00, 95% CI [-3.22, -2.78]; t(210) = -13.5; p < .001, and in depressive symptoms, B = -1.46, 95% CI [-1.64, -1.28]; t(192) = -8.32; p < .001. The effects of PE treatment did not differ by clinical setting and participants with moderate to severe injuries reported more rapid gains than those with a history of mild TBI. The results provide evidence that PE may well be effective for veterans with PTSD and TBI. PMID:26201688

  20. Prolonged Exposure vs Dynamic Therapy for Adolescent PTSD: A Pilot Randomized Controlled Trial

    PubMed Central

    Gilboa-Schechtman, Eva; Foa, Edna; Shafran, Naama; Aderka, Idan M.; Powers, Mark B.; Rachamim, Lilach; Rosenbach, Lea; Yadin, Elna; Apter, Alan

    2010-01-01

    Objective To examine the efficacy and maintenance of developmentally adapted prolonged Exposure (PE-A) compared to active control Time Limited Dynamic Therapy (TLDP-A) for reducing post-traumatic and depressive symptoms in adolescent victims of single event traumas. Method 38 adolescents (age 12–18) were randomly assigned to receive either PE-A or TLDP-A. Results Both treatments resulted in decreased post-traumatic stress disorder and depression, and increased functioning. PE-A exhibited greater reduction of PTSD and depression symptom severity, and greater increase in global functioning than did TDLP-A. At post-treatment, 68.4% of adolescents beginning treatment with PE-A and 36.8% of those beginning treatment with TLDP-A no longer met diagnostic criteria for PTSD. Treatment gains were maintained at 6 and 17 months follow-up. Conclusions Brief individual therapy is effective in reducing post-traumatic distress and behavioral trauma-focused components enhance efficacy. PMID:20855048

  1. Change in Sleep Symptoms across Cognitive Processing Therapy and Prolonged Exposure: A Longitudinal Perspective

    PubMed Central

    Gutner, Cassidy A.; Casement, Melynda D.; Gilbert, Karina Stavitsky; Resick, Patricia A.

    2013-01-01

    Sleep disturbance is a core component in posttraumatic stress disorder (PTSD). Although cognitive-behavioral treatments for PTSD reduce the severity of sleep symptoms, they do not lead to complete remission. The present study examines the impact of Cognitive Processing Therapy (CPT) and Prolonged Exposure (PE) on subjective measures of sleep disturbance from treatment randomization through long-term follow-up (LTFU). Participants were 171 female rape victims with PTSD who were randomly assigned to CPT, PE, or Minimal Attention (MA). After 6-weeks, the MA group was randomized to CPT or PE. Sleep symptoms were assessed at baseline, post-MA, post-treatment, 3-months, 9-months and LTFU using the Pittsburgh Sleep Quality Index (PSQI) and nightmare and insomnia items from the Clinician Administered PTSD Scale. Change in sleep during MA, from pre- to post-treatment for CPT and PE, and from post-treatment through LTFU was assessed using piecewise hierarchical linear modeling with the intent-to-treat sample. Controlling for medication, sleep improved during CPT and PE compared to MA, and treatment gains were maintained through LTFU. CPT and PE were equally efficacious and improvements persist over LTFU, yet, neither produced remission of sleep disturbance. Overall, sleep symptoms do not remit and may warrant sleep-specific treatments. PMID:24184428

  2. Static and dynamic vestibulo-cervico-ocular responses after prolonged exposure to microgravity.

    PubMed

    Kornilova, L N; Sagalovitch, S V; Temnikova, V V; Yakushev, A G

    2007-01-01

    The vestibular function was investigated in 13 Russian crew members of the ISS missions on days 1(2), 4(5), and 8(9) after prolonged exposure to microgravity (126 to 195 days). The static torsional otolith-cervico-ocular reflex was studied, as well as the dynamic vestibulo-cervico-ocular responses, vestibular reactivity, and spontaneous oculomotor activity using videooculography (VOG) and electrooculography (EOG) for simultaneous recording of eye movements. On days 1-2 of return to the gravity (R+1-2), the cosmonauts were found to increase the spontaneous oculomotor activity (floating eye movements, both typical and atypical forms of spontaneous nystagmus, square wave jerks, gaze nystagmus) with the head held in the vertical position. The otolith function during static head inclinations to the right or left shoulder at 30 degrees was suppressed as determined by the inversion or absence, or reduction by half of the amplitude of torsional compensatory eye counter-rolling and the vestibular reactivity during head yaw movements at 0.125 Hz was increased as revealed by a lowered threshold and an increased intensity of vestibular nystagmus. The pattern, depth, dynamics, and velocity of the vestibular function recovery varied with individual participants in the investigation. However, the suppressed otolith functioning in the period of readaptation to the normal gravity was, as a rule, accompanied by an exaggerated vestibular reactivity. PMID:18626133

  3. The effects of prolonged exposure and sertraline on emotion regulation in individuals with posttraumatic stress disorder.

    PubMed

    Jerud, Alissa B; Pruitt, Larry D; Zoellner, Lori A; Feeny, Norah C

    2016-02-01

    The effects of current posttraumatic stress disorder (PTSD) interventions on emotion regulation are relatively unknown. Many conceptualize PTSD as a disorder of emotion dysregulation, and clinicians often fear that emotion regulation impairments will not change with stand-alone PTSD treatments, particularly for individuals with pre-existing emotion regulation difficulties. The present study examined changes in emotion regulation (expressive suppression, cognitive reappraisal, negative mood regulation) with prolonged exposure (PE) therapy or sertraline, specifically examining whether those with higher pre-existing emotion regulation difficulties improved over treatment on these indices. Individuals with chronic PTSD (N = 200) received 10 weeks of PE or sertraline and were followed through 6-month follow-up. Emotion regulation was assessed at pre- and post-treatment and at 3- and 6-month follow-up. Individuals with poorer initial emotion regulation showed greater improvement on all indices of emotion regulation, regardless of which treatment they received. Changes occurred during active treatment and were maintained over follow-up. These findings have both theoretical and clinical implications, arguing that emotion regulation is not impaired across all individuals with PTSD and that PE and sertraline effectively address emotion regulation difficulties. PMID:26723004

  4. Change in sleep symptoms across Cognitive Processing Therapy and Prolonged Exposure: a longitudinal perspective.

    PubMed

    Gutner, Cassidy A; Casement, Melynda D; Stavitsky Gilbert, Karina; Resick, Patricia A

    2013-12-01

    Sleep disturbance is a core component in posttraumatic stress disorder (PTSD). Although cognitive-behavioral treatments for PTSD reduce the severity of sleep symptoms, they do not lead to complete remission. The present study examines the impact of Cognitive Processing Therapy (CPT) and Prolonged Exposure (PE) on subjective measures of sleep disturbance from treatment randomization through long-term follow-up (LTFU). Participants were 171 female rape victims with PTSD who were randomly assigned to CPT, PE, or Minimal Attention (MA). After 6-weeks, the MA group was randomized to CPT or PE. Sleep symptoms were assessed at baseline, post-MA, post-treatment, 3-months, 9-months and LTFU using the Pittsburgh Sleep Quality Index (PSQI) and nightmare and insomnia items from the Clinician Administered PTSD Scale. Change in sleep during MA, from pre- to post-treatment for CPT and PE, and from post-treatment through LTFU was assessed using piecewise hierarchical linear modeling with the intent-to-treat sample. Controlling for medication, sleep improved during CPT and PE compared to MA, and treatment gains were maintained through LTFU. CPT and PE were equally efficacious and improvements persist over LTFU, yet, neither produced remission of sleep disturbance. Overall, sleep symptoms do not remit and may warrant sleep-specific treatments. PMID:24184428

  5. The Effect of Lake Temperatures and Emissions on Ozone Exposure in the Western Great Lakes Region

    SciTech Connect

    Fast, Jerome D. ); Heilman, Warren E.

    2003-09-01

    A meteorological-chemical model with a 12-km horizontal grid spacing was used to simulate the evolution of ozone over the western Great Lakes region during a 30-day period in the summer of 1999. High ozone production rates were produced over the surface of the lakes as a result of stable atmospheric conditions that trapped ozone precursors within a shallow layer during the day. Simulations with lake temperatures derived from either satellite measurements or climatological values produced ozone mixing ratios over the lakes and around the lake shores that differed by as much as 50 ppb while differences over land were usually 10 ppb or less. Through another series of sensitivity studies that varied ozone precursor emissions, it was shown that a reduction of 50% NOx or VOC would lower the 60 ppb ozone exposure by up to 50 h per month in the remote forest regions over the northern Great Lakes. The implications of these results on future climate change and air quality in the region is discussed.

  6. Stratospheric ozone changes under solar geoengineering: implications for UV exposure and air quality

    NASA Astrophysics Data System (ADS)

    Nowack, Peer Johannes; Abraham, Nathan Luke; Braesicke, Peter; Pyle, John Adrian

    2016-03-01

    Various forms of geoengineering have been proposed to counter anthropogenic climate change. Methods which aim to modify the Earth's energy balance by reducing insolation are often subsumed under the term solar radiation management (SRM). Here, we present results of a standard SRM modelling experiment in which the incoming solar irradiance is reduced to offset the global mean warming induced by a quadrupling of atmospheric carbon dioxide. For the first time in an atmosphere-ocean coupled climate model, we include atmospheric composition feedbacks for this experiment. While the SRM scheme considered here could offset greenhouse gas induced global mean surface warming, it leads to important changes in atmospheric composition. We find large stratospheric ozone increases that induce significant reductions in surface UV-B irradiance, which would have implications for vitamin D production. In addition, the higher stratospheric ozone levels lead to decreased ozone photolysis in the troposphere. In combination with lower atmospheric specific humidity under SRM, this results in overall surface ozone concentration increases in the idealized G1 experiment. Both UV-B and surface ozone changes are important for human health. We therefore highlight that both stratospheric and tropospheric ozone changes must be considered in the assessment of any SRM scheme, due to their important roles in regulating UV exposure and air quality.

  7. Ozone exposure and flux-based response functions for photosynthetic traits in wheat, maize and poplar.

    PubMed

    Bagard, Matthieu; Jolivet, Yves; Hasenfratz-Sauder, Marie-Paule; Gérard, Joëlle; Dizengremel, Pierre; Le Thiec, Didier

    2015-11-01

    Ozone exposure- and dose-response relationships based on photosynthetic leaf traits (CO2 assimilation, chlorophyll content, Rubisco and PEPc activities) were established for wheat, maize and poplar plants grown in identical controlled conditions, providing a comparison between crop and tree species, as well as between C3 and C4 plants. Intra-specific variability was addressed by comparing two wheat cultivars with contrasting ozone tolerance. Depending on plant models and ozone levels, first-order, second-order and segmented linear regression models were used to derive ozone response functions. Overall, flux-based functions appeared superior to exposure-based functions in describing the data, but the improvement remained modest. The best fit was obtained using the POD0.5 for maize and POD3 for poplar. The POD6 appeared relevant for wheat, although intervarietal differences were found. Our results suggest that taking into account the dynamics of leaf antioxidant capacity could improve current methods for ozone risk assessment for plants. PMID:26253315

  8. Effects of chronic exposure to ozone on collagen in rat lung

    SciTech Connect

    Wright, E.S.; Kehrer, J.P.; White, D.M.; Smiler, K.L.

    1988-03-15

    Pulmonary fibrosis is a consequence of severe injury from some toxic agents including high doses of ozone. It is not known, however, whether chronic exposure to low doses of ozone, such as those encountered in polluted ambient atmospheres, could also result in abnormal accumulations of lung collagen. Rats were exposed to ozone for 20 hr per day, 7 days per week for 3, 6, 12, and 18 months at concentrations of 0.12, 0.25, or 0.50 ppm. Controls were exposed under identical conditions to purified air. Upon removal from the chambers, rats were euthanized and lung tissue slices incubated with (14C)proline. The incorporation of 14C into hydroxyproline and the total hydroxyproline content of lung tissue were measured as estimates of lung collagen synthesis and content, respectively. The formation of labeled hydroxyproline tended to decrease significantly with time in controls and at the three ozone doses. There were, however, no significant dose-related changes at any of the time points tested. Total lung hydroxyproline increased with age in all groups, but no dose-related changes were detected at any time point. It was concluded that chronic exposure of rats to ozone at concentrations which approximate ambient urban concentrations did not affect normal age-related changes in either synthesis or accumulation of lung collagen.

  9. Effects of in vitro ozone exposure on peroxidative damage, membrane leakage, and taurine content of rat alveolar macrophages

    SciTech Connect

    Banks, M.A.; Porter, D.W.; Martin, W.G.; Castranova, V. )

    1990-08-01

    Rat alveolar macrophages (AM) were isolated by pulmonary lavage, allowed to adhere to a tissue culture flask, and then exposed to 0.45 +/- 0.05 ppm ozone. After exposures ranging from 0 to 60 min, the medium was decanted and cells were harvested. Cells were assayed for oxidant damage and media analyzed for leakage of intracellular components. Increasing length of exposure to ozone resulted in a decreased number of adherent AM and decreased cell viability. Resting and zymosan-stimulated chemiluminescence increased immediately after ozone exposure and reached a maximum at 15-30 min, then declined to initial levels after 60 min of ozone exposure. Lipid peroxidation and leakage of protein and K+ ions increased with increasing length of exposure to ozone, while leakage of reduced and oxidized glutathione increased through 30 min, then declined (reduced) or leveled off (oxidized). Activity of the Na+/K+ ATPase decreased with time while intracellular taurine concentration exhibited an initial rise, peaked at 30 min, and then returned to the untreated level. Leakage of taurine into the medium increased with time of exposure, suggesting that exposure of AM to ozone results in a shift from bound to free intracellular taurine. These data indicate that in vitro exposure of AM to ozone results in a time-dependent alteration of cell function, membrane integrity, and viability.

  10. Effect of exposures to ambient ozone on ventilatory lung function in children

    SciTech Connect

    Higgins, I.T.; D'Arcy, J.B.; Gibbons, D.I.; Avol, E.L.; Gross, K.B. )

    1990-05-01

    This study was undertaken to determine if the ventilatory capacity of children is affected by hourly concentrations of ozone inhaled during their daily activity. Over a 3-wk period children who were attending a summer camp in the San Bernardino mountains of California performed spirometry up to three times per day during their stay at the camp. Ozone, oxides of nitrogen, sulfur dioxide, temperature, and relative humidity were measured continuously. Daily average measurements of total suspended particulate and the PM10 particulate fraction were also made. Hourly ozone concentrations at the time of testing varied between 20 and 245 ppb. Regressions of each individual's FEV1 and FVC supported the view that high ozone levels reduced these lung function parameters. The average regression coefficient for FEV1 on ozone was -0.39 ml/ppb (SEM = 0.12) and for FVC -0.44 ml/ppb (SEM = 0.15), both of which were significantly different from zero. Statistical allowance for temperature and humidity increased the magnitude of these slopes. Nitrogen dioxide never exceeded 40 ppb during the time of testing and averaged 13 ppb. Sulfur dioxide's highest measurement was 8 ppb and often was at the limit of detection. Neither NO2 nor SO2 was considered in the statistical modeling. Data were divided based on whether each subject had been exposed to levels of ozone in excess of the National Ambient Air Quality Standard (NAAQS) during the several hours previous to being tested. Exposures exceeding the NAAQS indicated a significant negative relationship between ozone and FEV1, FVC, and PEFR. Data for nonexceedance periods did not indicate this negative relationship for any of the three lung function parameters, but it could not be determined if this was due to an absence of an ozone effect or to a combination of the increased variability and decreased size of this data subset.

  11. Structural and biochemical effects in lungs of Japanese quail following a 1-week exposure to ozone

    SciTech Connect

    Rombout, P.J.; Dormans, J.A.; van Bree, L.; Marra, M. )

    1991-02-01

    The effect of ozone inhalation on birds was investigated. Japanese quail were exposed continuously to 0, 0.3, 1.0, and 3.0 mg/m3 ozone (0, 0.15, 0.50, and 1.50 ppm, respectively) for 7 days. Pulmonary effects were determined by light and electron microscopy as well as by biochemistry. Focal areas of hemorrhages were noticed in the birds exposed to 1.0 mg/m3 ozone. Additional effects after exposure to 1 mg/m3 included loss of cilia in trachea and bronchi, an inflammatory response, and necrosis of air capillary epithelial cells. Following exposure to 3 mg/m3 many atria of tertiary bronchi were completely obstructed by extensive hemorrhages, metaplasia of atrial wall cells, and hypertrophy of smooth muscle cells. Lung biochemistry data revealed that in the 3 mg/m3 group lactate dehydrogenase, glucose-6-phosphate dehydrogenase, and glutathione reductase activities were significantly increased. In the 0.3 and 1.0 mg/m3 exposure groups no effects on lung antioxidant enzymes were observed. In conclusion, Japanese quail appear to respond to ozone exposure in a different way than mammals. Since no signs of repair in air capillary epithelium after 7 days of continuous exposure were observed, the quail seems to lack the morphological and biochemical repair ability as is observed in mammals. Therefore, more research of the effects of ozone on birds seems to be necessary, both from a mechanistic and an ecological point of view.

  12. Overview of ozone human exposure and health risk analyses used in the U.S. EPA's review of the ozone air quality standard.

    SciTech Connect

    Whitfield, R. G.

    1999-03-04

    This paper presents an overview of the ozone human exposure and health risk analyses developed under sponsorship of the U.S. Environmental Protection Agency (EPA). These analyses are being used in the current review of the national ambient air quality standards (NAAQS) for ozone. The analyses consist of three principal steps: (1) estimating short-term ozone exposure for particular populations (exposure model); (2) estimating population response to exposures or concentrations (exposure-response or concentration-response models); and (3) integrating concentrations or exposure with concentration-response or exposure-response models to produce overall risk estimates (risk model). The exposure model, called the probabilistic NAAQS exposure model for ozone (pNEM/03), incorporates the following factors: hourly ambient ozone concentrations; spatial distribution of concentrations; ventilation state of individuals at time of exposure; and movement of people through various microenvironments (e.g., outdoors, indoors, inside a vehicle) of varying air quality. Exposure estimates are represented by probability distributions. Exposure-response relationships have been developed for several respiratory symptom and lung function health effects, based on the results of controlled human exposure studies. These relationships also are probabilistic and reflect uncertainties associated with sample size and variability of response among subjects. The analyses also provide estimates of excess hospital admissions in the New York City area based on results from an epidemiology study. Overall risk results for selected health endpoints and recently analyzed air quality scenarios associated with alternative 8-hour NAAQS and the current 1-hour standard for outdoor children are used to illustrate application of the methodology.

  13. Short-Term Exposure to Ozone Does Not Impair Vascular Function or Affect Heart Rate Variability in Healthy Young Men

    PubMed Central

    Barath, Stefan; Langrish, Jeremy P.; Blomberg, Anders

    2013-01-01

    Air pollution exposure is associated with cardiovascular morbidity and mortality, yet the role of individual pollutants remains unclear. In particular, there is uncertainty regarding the acute effect of ozone exposure on cardiovascular disease. In these studies, we aimed to determine the effect of ozone exposure on vascular function, fibrinolysis, and the autonomic regulation of the heart. Thirty-six healthy men were exposed to ozone (300 ppb) and filtered air for 75min on two occasions in randomized double-blind crossover studies. Bilateral forearm blood flow (FBF) was measured using forearm venous occlusion plethysmography before and during intra-arterial infusions of vasodilators 2–4 and 6–8h after each exposure. Heart rhythm and heart rate variability (HRV) were monitored during and 24h after exposure. Compared with filtered air, ozone exposure did not alter heart rate, blood pressure, or resting FBF at either 2 or 6h. There was a dose-dependent increase in FBF with all vasodilators that was similar after both exposures at 2–4h. Ozone exposure did not impair vasomotor or fibrinolytic function at 6–8h but rather increased vasodilatation to acetylcholine (p = .015) and sodium nitroprusside (p = .005). Ozone did not affect measures of HRV during or after the exposure. Our findings do not support a direct rapid effect of ozone on vascular function or cardiac autonomic control although we cannot exclude an effect of chronic exposure or an interaction between ozone and alternative air pollutants that may be responsible for the adverse cardiovascular health effects attributed to ozone. PMID:23872581

  14. PROTEIN ACCUMULATION IN LUNG LAVAGE FLUID FOLLOWING OZONE EXPOSURE

    EPA Science Inventory

    Accumulation of protein in lung lavage fluid was used as an indicator of pulmonary damage following exposure of guinea pigs to 03. Exposure of animals to 510, 1000 or 1960 micrograms/cu. m. (O.26, 0.51 or 1.0 ppm) of O3 for 72 hours resulted in significantly elevated levels of la...

  15. Transmission electron microscopy study of stress-ruptured aged 304H stainless steel after prolonged exposure in service

    SciTech Connect

    Sengupta, A.; Balogh, M.

    1996-12-01

    Type 304H stainless steel is widely used for long-term, high-temperature applications, e.g., superheater tubes in steam generators. The 304H stainless steel tube in the present investigation has been exposed in service to a temperature range of 565 to 595 C for a prolonged period (in excess of 20 years). Metallographic and transmission electron microscopic analysis was carried out on exposed material to study the nature and type of precipitates formed in this material after prolonged exposure in service.

  16. Transmission electron microscopy study of stress- ruptured aged 304h stainless steel after prolonged exposure in service

    NASA Astrophysics Data System (ADS)

    Sengupta, A.; Balogh, M.

    1996-12-01

    Type 304H stainless steel is widely used for long- term, high- temperature applications, e.g., superheater tubes in steam generators. The 304H stainless steel tube in the present investigation has been exposed in service to a temperature range of 565 to 595 °C for a prolonged period (in excess of 20 years). Metallographic and transmission electron microscopic analysis was carried out on exposed material to study the nature and type of precipitates formed in this material after prolonged exposure in service.

  17. Plasmodium berghei infection in mice: effect of low-level ozone exposures

    SciTech Connect

    Moore, G.S.; Calabrese, E.J.; Molteni, K.H.

    1984-07-01

    Animal and human studies have accumulated that report erythrocyte effects from inhaled ozone (O/sub 3/). It was the purpose of this research to demonstrate the effects of O/sub 3/ exposure on the course of parasitemia in mice. A study was designed utilizing Plasmodium berghei, a murine malarial parasite host-specific for rodents, as the specific pathogen. The purpose of this project was to study mortality and percent parasitemia in the A/J mouse first infected with P. berghei and then exposed to low levels of ozone.

  18. A probabilistic assessment of health risks associated with short-term exposure to tropospheric ozone

    SciTech Connect

    Whitfield, R.G; Biller, W.F.; Jusko, M.J.; Keisler, J.M.

    1996-06-01

    The work described in this report is part of a larger risk assessment sponsored by the U.S. Environmental Protection Agency. Earlier efforts developed exposure-response relationships for acute health effects among populations engaged in heavy exertion. Those efforts also developed a probabilistic national ambient air quality standards exposure model and a general methodology for integrating probabilistic exposure-response relation- ships and exposure estimates to calculate overall risk results. Recently published data make it possible to model additional health endpoints (for exposure at moderate exertion), including hospital admissions. New air quality and exposure estimates for alternative national ambient air quality standards for ozone are combined with exposure-response models to produce the risk results for hospital admissions and acute health effects. Sample results explain the methodology and introduce risk output formats.

  19. Incorporation of glucose carbons into rat lung lipids after exposure to 0.6 ppm ozone.

    PubMed

    Bassett, D J; Rabinowitz, J L

    1985-05-01

    Continuous exposure to low concentrations of ozone has previously been associated with proliferation of lung alveolar type II epithelial cells. In this study, 14C incorporation into tissue lipids was determined in isolated rat lungs by perfusion with [U-14C]glucose, at a time of maximal hyperplasia brought about by 3 days continuous exposure to 0.6 ppm ozone. Ozone exposed lungs exhibited increased rates of glycolytic energy production, indicated by an 89% increase in 3H2O generation on perfusion with [5-3H]glucose, from a control value of 17.5 +/- 2.1 mumol X h-1 X g-1 X dry wt-1 (+/- SE, n = 4). Ozone exposure resulted in enhanced 14C incorporations into glyceride-glycerol and fatty acid moieties of lung lipids of 95 and 180%, respectively, with a greater proportion of label being recovered in shorter chain fatty acids. Although increased labeling was observed in both neutral and phospholipids, the pattern of 14C recovery suggested a relative increased glucose carbon incorporation into lung free fatty acids, phosphatidic acid, and such membrane associated lipids as phosphatidylinositol and those containing sphingosine. These results are consistent with the needs of a dividing cell population for enhanced energy production and synthesis of new lipids. PMID:3993775

  20. Early life exposure to allergen and ozone results in altered development in adolescent rhesus macaque lungs

    SciTech Connect

    Herring, M.J.; Putney, L.F.; St George, J.A.; Avdalovic, M.V.; Schelegle, E.S.; Miller, L.A.; Hyde, D.M.

    2015-02-15

    In rhesus macaques, previous studies have shown that episodic exposure to allergen alone or combined with ozone inhalation during the first 6 months of life results in a condition with many of the hallmarks of asthma. This exposure regimen results in altered development of the distal airways and parenchyma (Avdalovic et al., 2012). We hypothesized that the observed alterations in the lung parenchyma would be permanent following a long-term recovery in filtered air (FA) housing. Forty-eight infant rhesus macaques (30 days old) sensitized to house dust mite (HDM) were treated with two week cycles of FA, house dust mite allergen (HDMA), ozone (O{sub 3}) or HDMA/ozone (HDMA + O{sub 3}) for five months. At the end of the five months, six animals from each group were necropsied. The other six animals in each group were allowed to recover in FA for 30 more months at which time they were necropsied. Design-based stereology was used to estimate volumes of lung components, number of alveoli, size of alveoli, distribution of alveolar volumes, interalveolar capillary density. After 30 months of recovery, monkeys exposed to HDMA, in either group, had significantly more alveoli than filtered air. These alveoli also had higher capillary densities as compared with FA controls. These results indicate that early life exposure to HDMA alone or HDMA + O{sub 3} alters the development process in the lung alveoli. - Highlights: • Abnormal lung development after postnatal exposure to ozone and allergen • This remodeling is shown as smaller, more numerous alveoli and narrower airways. • Allergen appears to have more of an effect than ozone during recovery. • These animals also have continued airway hyperresponsiveness (Moore et al. 2014)

  1. Protein cross-linking and oligomerization through dityrosine formation upon exposure to ozone

    NASA Astrophysics Data System (ADS)

    Liu, Fobang; Kampf, Christopher; Reinmuth-Selzle, Kathrin; Berkemeier, Thomas; Shiraiwa, Manabu; Pöschl, Ulrich

    2015-04-01

    Air pollution is a potential factor for the increasing prevalence of allergic diseases. Airborne allergenic proteins can be directly exposed to air pollution promoting post-translational modifications, which can enhance the allergenic potential of proteins. The formation of dimers or oligomers of allergenic proteins has been reported to result in an enhanced allergenicity. However, the oligomerization process for proteins at atmospherically relevant concentration of O3 is still largely unknown. In this study, the kinetics and reaction mechanism of protein oligomerization upon ozone exposure were studied at atmospherically relevant ozone concentrations and relative humidity (RH) in coated-wall flow tube experiments. Bovine Serum Albumin (BSA) was used as a model protein. Protein ozone exposure was studied for different protein phase-states, i.e. amorphous solid (45% RH experiments), semi-solid (96% RH experiments) and liquid (bulk solution experiments) to account for the differences of phase in atmospheric particulates, e.g., aerosol particles and cloud droplets. Product analysis was performed using a size exclusion chromatography-high performance liquid chromatography-diode array detector (SEC-HPLC-DAD). We demonstrate that protein cross-linking upon ozone exposure can be attributed to the formation of covalent intermolecular dityrosine species by gel electrophoretic and fluorescence spectroscopic methods. The exposure experiments indicate that in addition to ozone concentration, the oligomerization process was depending on the phase-state of protein. In liquid-phase experiments, dimer formation was significantly enhanced, thus indicating a potential relevance of in-cloud processes for protein oligomerization. The reactive turnover is higher at 96% RH compared to 45% RH, indicating a higher bulk diffusion coefficient at high RH, which is explicitly resolved by kinetic modeling. Further, the reactive turnover showed a strong correlation to particle surface

  2. Prolonged exposure to high and variable phenylalanine levels over the lifetime predicts brain white matter integrity in children with phenylketonuria.

    PubMed

    Hood, Anna; Antenor-Dorsey, Jo Ann V; Rutlin, Jerrel; Hershey, Tamara; Shimony, Joshua S; McKinstry, Robert C; Grange, Dorothy K; Christ, Shawn E; Steiner, Robert; White, Desiree A

    2015-01-01

    In this study, we retrospectively examined the microstructural white matter integrity of children with early- and continuously-treated PKU (N=36) in relation to multiple indices of phenylalanine (Phe) control over the lifetime. White matter integrity was assessed using mean diffusivity (MD) from diffusion tensor imaging (DTI). Eight lifetime indices of Phe control were computed to reflect average Phe (mean, index of dietary control), variability in Phe (standard deviation, standard error of estimate, % spikes), change in Phe with age (slope), and prolonged exposure to Phe (mean exposure, standard deviation exposure). Of these indices, mean Phe, mean exposure, and standard deviation exposure were the most powerful predictors of widespread microstructural white matter integrity compromise. Findings from the two previously unexamined exposure indices reflected the accumulative effects of elevations and variability in Phe. Given that prolonged exposure to elevated and variable Phe was particularly detrimental to white matter integrity, Phe should be carefully monitored and controlled throughout childhood, without liberalization of Phe control as children with PKU age. PMID:25481106

  3. Prolonged Exposure to High and Variable Phenylalanine Levels over the Lifetime Predicts Brain White Matter Integrity in Children with Phenylketonuria

    PubMed Central

    Hood, Anna; Antenor-Dorsey, Jo Ann V.; Rutlin, Jerrel; Hershey, Tamara; Shimony, Joshua S.; McKinstry, Robert C.; Grange, Dorothy K.; Christ, Shawn E.; Steiner, Robert; White, Desiree A.

    2014-01-01

    In this study, we retrospectively examined the microstructural white matter integrity of children with early- and continuously-treated PKU (N = 36) in relation to multiple indices of phenylalanine (Phe) control over the lifetime. White matter integrity was assessed using mean diffusivity (MD) from diffusion tensor imaging (DTI). Eight lifetime indices of Phe control were computed to reflect average Phe (mean, index of dietary control), variability in Phe (standard deviation, standard error of estimate, % spikes), change in Phe with age (slope), and prolonged exposure to Phe (mean exposure, standard deviation exposure). Of these indices, mean Phe, mean exposure, and standard deviation exposure were the most powerful predictors of widespread microstructural white matter integrity compromise. Findings from the two previously unexamined exposure indices reflected the accumulative effects of elevations and variability in Phe. Given that prolonged exposure to elevated and variable Phe was particularly detrimental to white matter integrity, Phe should be carefully monitored and controlled throughout childhood, without liberalization of Phe control as children with PKU age. PMID:25481106

  4. Vestibulo-Cervico-Ocular Responses and Tracking Eye Movements after Prolonged Exposure to Microgravity

    NASA Technical Reports Server (NTRS)

    Kornilova, L. N.; Naumov, I. A.; Azarov, K. A.; Sagalovitch, S. V.; Reschke, Millard F.; Kozlovskaya, I. B.

    2007-01-01

    The vestibular function and tracking eye movements were investigated in 12 Russian crew members of ISS missions on days 1(2), 4(5-6), and 8(9-10) after prolonged exposure to microgravity (126 to 195 days). The spontaneous oculomotor activity, static torsional otolith-cervico-ocular reflex, dynamic vestibulo-cervico-ocular responses, vestibular reactivity, tracking eye movements, and gaze-holding were studied using videooculography (VOG) and electrooculography (EOG) for parallel eye movement recording. On post-flight days 1-2 (R+1-2) some cosmonauts demonstrated: - an increased spontaneous oculomotor activity (floating eye movements, spontaneous nystagmus of the typical and atypical form, square wave jerks, gaze nystagmus) with the head held in the vertical position; - suppressed otolith function (absent or reduced by one half amplitude of torsional compensatory eye counter-rolling) with the head inclined statically right- or leftward by 300; - increased vestibular reactivity (lowered threshold and increased intensity of the vestibular nystagmus) during head turns around the longitudinal body axis at 0.125 Hz; - a significant change in the accuracy, velocity, and temporal characteristics of the eye tracking. The pattern, depth, dynamics, and velocity of the vestibular function and tracking eye movements recovery varied with individual participants in the investigation. However, there were also regular responses during readaptation to the normal gravity: - suppression of the otolith function was typically accompanied by an exaggerated vestibular reactivity; - the structure of visual tracking (the accuracy of fixational eye rotations, smooth tracking, and gaze-holding) was disturbed (the appearance of correcting saccades, the transition of smooth tracking to saccadic tracking) only in those cosmonauts who, in parallel to an increased reactivity of the vestibular input, also had central changes in the oculomotor system (spontaneous nystagmus, gaze nystagmus).

  5. Cerebral volumetric changes induced by prolonged hypoxic exposure and whole-body exercise.

    PubMed

    Rupp, Thomas; Jubeau, Marc; Lamalle, Laurent; Warnking, Jan M; Millet, Guillaume Y; Wuyam, Bernard; Esteve, François; Levy, Patrick; Krainik, Alexandre; Verges, Samuel

    2014-11-01

    The present study assessed the isolated and synergetic effects of hypoxic exposure and prolonged exercise on cerebral volume and subedema and symptoms of acute mountain sickness (AMS). Twelve healthy males performed three semirandomized blinded 11-hour sessions with (1) an inspiratory oxygen fraction (FiO2) of 12% and 4-hour cycling, (2) FiO2=21% and 4-hour cycling, and (3) FiO2=8.5% to 12% at rest (matching arterial oxygen saturation measured during the first hypoxic session). Volumetric, apparent diffusion coefficient (ADC), and arterial spin labelling 3T magnetic resonance imaging sequences were performed after 30 minutes and 10 hours in each session. Thirty minutes of hypoxia at rest induced a significant increase in white-matter volume (+0.8±1.0% compared with normoxia) that was exacerbated after 10 hours of hypoxia at rest (+1.5±1.1%) or with cycling (+1.6±1.1%). Total brain parenchyma volume increased significantly after 10 hours of hypoxia with cycling only (+1.3±1.1%). Apparent diffusion coefficient was significantly reduced after 10 hours of hypoxia at rest or with cycling. No significant change in cerebral blood flow was observed. These results demonstrate changes in white-matter volume as early as after 30 minutes of hypoxia that worsen after 10 hours, probably due to cytotoxic edema. Exercise accentuates the effect of hypoxia by increasing total brain volume. These changes do not however correlate with AMS symptoms. PMID:25160673

  6. Tissue deoxygenation kinetics induced by prolonged hypoxic exposure in healthy humans at rest.

    PubMed

    Rupp, Thomas; Leti, Thomas; Jubeau, Marc; Millet, Guillaume Y; Bricout, Veronique A; Levy, Patrick; Wuyam, Bernard; Perrey, Stephane; Verges, Samuel

    2013-09-01

    This study aimed to investigate the effects of sustained hypoxic exposure on cerebral and muscle oxygenation and cardiorespiratory function at rest. Eleven healthy subjects inhaled a normobaric hypoxic (FiO2=0.12) or normoxic (FiO2=0.21) gas mixture for 4 h at rest, on two separated blinded sessions. Arterial oxygen saturation (SpO2), heart rate variability (HRV), end-tidal CO2 (EtCO2), and oxygenation of quadriceps muscle, prefrontal and motor cortices assessed by near-infrared spectroscopy (NIRS) were measured continuously during each session. Acute mountain sickness symptoms were evaluated at the end of each session. During a hypoxic session, SpO2 reduction (∼13%) plateaued after 20 min, while deoxygenation pattern took 30 to 40 min at the cerebral sites to plateau (+5.3±1.6  μMol of deoxygenated-hemoglobin). Deoxygenation was more pronounced in the cerebral cortex compared to the muscle (+2.1±2.3  μMol of deoxygenated-hemoglobin), and NIRS-derived tissue perfusion index showed distinct profiles between the muscle (hypoperfusion) and the brain (hyperperfusion) with prolonged hypoxia. Changes in tissue oxygenation were not associated with cardiorespiratory responses (e.g., HRV, EtCO2) and altitude sickness symptom appearance during hypoxic sessions. These data demonstrate that sustained hypoxia elicits time delay in changes between arterial and tissue (especially cerebral) oxygenation, as well as a tissue-specific sensitivity. PMID:24064948

  7. Nutritional considerations during prolonged exposure to a confined, hyperbaric, hyperoxic environment: recommendations for saturation divers.

    PubMed

    Deb, S K; Swinton, P A; Dolan, E

    2016-01-01

    Saturation diving is an occupation that involves prolonged exposure to a confined, hyperoxic, hyperbaric environment. The unique and extreme environment is thought to result in disruption to physiological and metabolic homeostasis, which may impact human health and performance. Appropriate nutritional intake has the potential to alleviate and/or support many of these physiological and metabolic concerns, whilst enhancing health and performance in saturation divers. Therefore, the purpose of this review is to identify the physiological and practical challenges of saturation diving and consequently provide evidence-based nutritional recommendations for saturation divers to promote health and performance within this challenging environment. Saturation diving has a high-energy demand, with an energy intake of between 44 and 52 kcal/kg body mass per day recommended, dependent on intensity and duration of underwater activity. The macronutrient composition of dietary intake is in accordance with the current Institute of Medicine guidelines at 45-65 % and 20-35 % of total energy intake for carbohydrate and fat intake, respectively. A minimum daily protein intake of 1.3 g/kg body mass is recommended to facilitate body composition maintenance. Macronutrient intake between individuals should, however, be dictated by personal preference to support the attainment of an energy balance. A varied diet high in fruit and vegetables is highly recommended for the provision of sufficient micronutrients to support physiological processes, such as vitamin B12 and folate intake to facilitate red blood cell production. Antioxidants, such as vitamin C and E, are also recommended to reduce oxidised molecules, e.g. free radicals, whilst selenium and zinc intake may be beneficial to reinforce endogenous antioxidant reserves. In addition, tailored hydration and carbohydrate fueling strategies for underwater work are also advised. PMID:26744625

  8. Ozone changes under solar geoengineering: implications for UV exposure and air quality

    NASA Astrophysics Data System (ADS)

    Nowack, P. J.; Abraham, N. L.; Braesicke, P.; Pyle, J. A.

    2015-11-01

    Various forms of geoengineering have been proposed to counter anthropogenic climate change. Methods which aim to modify the Earth's energy balance by reducing insolation are often subsumed under the term Solar Radiation Management (SRM). Here, we present results of a standard SRM modelling experiment in which the incoming solar irradiance is reduced to offset the global mean warming induced by a quadrupling of atmospheric carbon dioxide. For the first time in an atmosphere-ocean coupled climate model, we include atmospheric composition feedbacks such as ozone changes under this scenario. Including the composition changes, we find large reductions in surface UV-B irradiance, with implications for vitamin D production, and increases in surface ozone concentrations, both of which could be important for human health. We highlight that both tropospheric and stratospheric ozone changes should be considered in the assessment of any SRM scheme, due to their important roles in regulating UV exposure and air quality.

  9. Impact of asthma, exposure period, and filters on human responses during exposures to ozone and its initiated chemistry products.

    PubMed

    Fadeyi, M O; Tham, K W; Wu, W Y

    2015-10-01

    The impact of asthma, exposure period, and filter condition downstream of the mixing box of air-conditioning system on building occupants' perceptual response, work performance, and salivary α-amylase secretion during exposures to ozone and its initiated chemistry products is studied. The experiments were conducted in a field environmental chamber (FEC) (240 m(3)) simulating an office environment. Experiments were conducted during periods when the air-handling system operated with new or used pleated panel filters at constant recirculation (7/h) and ventilation (1/h) rates. Average ozone and secondary organic aerosols (ozone-initiated chemistry products) measured during non-asthmatic and asthmatic subjects' 3-h exposures in the FEC were in the ranges approximately 20-37 ppb and approximately 1.6-3 μg/m(3), respectively. Asthmatic subjects' perceived odor intensity and sensory (eye, nose, and throat) irritation ratings were generally lower than those of non-asthmatic subjects, possibly explaining why asthmatic subjects accept perceived air quality more than non-asthmatic subjects. However, asthmatic subjects' perceived physiological-like symptom ratings (flu, chest tightness, and headache) and concentrations of secreted salivary α-amylase were generally higher than those of non-asthmatic subjects. Asthmatic subjects had significantly lower accuracy than non-asthmatic subjects in a task that required higher concentration although they had higher work speed. Filter condition did not make any significant difference for subjects' responses. PMID:25250543

  10. Exposure of surfactant protein A to ozone in vitro and in vivo impairs its interactions with alveolar cells

    SciTech Connect

    Oosting, R.S.; Van Iwaarden, J.F.; Van Bree, L.; Verhoef, J.; Van Golde, L.M.; Haagsman, H.P. )

    1992-01-01

    This study focused on the question of whether exposure of surfactant protein A (SP-A) to ozone affected properties of this protein that may be involved in regulating alveolar type II cell and alveolar macrophage functions. In vitro exposure of human or canine SP-A to ozone reduced the ability of this protein to inhibit phorbol-ester induced secretion of (3H)phosphatidylcholine by alveolar type II cells in culture. Ozone-exposed human SP-A showed a decreased ability to enhance phagocytosis of herpes simplex virus and to stimulate superoxide anion production by alveolar macrophages. Experiments with elastase showed that ozone-exposed canine SP-A was more susceptible to proteolysis. A conformational change of the protein could underlie this phenomenon. Surfactant isolated from ozone-exposed rats (0.4 ppm ozone for 12 h) was also less able to stimulate superoxide anion production by alveolar macrophages than surfactant from control rats, which suggested that SP-A in vivo was also susceptible to ozone. The results of this study suggest that SP-A-alveolar cell interactions can be inhibited by ozone exposure, which may contribute to the toxicity of ozone in the lungs.

  11. Interaction of ozone exposure with airway hyperresponsiveness and inflammation induced by trimellitic anhydride in sensitized guinea pigs

    SciTech Connect

    Sun, Jian; Chung, K.Fan

    1997-09-01

    The effect of prior ozone (O{sub 3}) exposure on airway hyperresponsiveness and inflammation induced by trimellitic anhydride (TMA) has been investigated in TMA-sensitized guinea pigs. Airway responsiveness was measured as the concentration of acetylcholine needed to increase baseline lung resistance (RL) by 300% (PC300). Ozone (3 ppm, for 3 h) caused an increase in-log PC300 at 1 h after exposure, with return of -log PC300 to control levels at 8 h. Ozone also increased baseline RL at 8 h. TMA challenge increase -log PC300 in TMA-sensitized guinea pigs at 8 h after challenge from 3.85 {+-} 0.09 to 4.11 {+-} 0.09. Ozone exposure prior to TMA challenge prevented the induction of airway hyperresponsiveness with a mean -log PC300 of 3.51 {+-} 0.20, which was not different from that of control TMA-Sensitized group. Baseline RL was significantly higher in ozone-pretreated animals after TMA challenge when compared to those of either control or challenged with TMA alone. Ozone had no effect on TMA challenge-induced BAL eosinophilia and neutrophilia. We conclude that a single exposure to ozone inhibits the increase in airway responsiveness, but increases the bronchoconstrictor response induced by TMA in TMA-Sensitized guinea pigs; however, the inflammatory airway response to TMA is unchanged by preexposure to ozone. 29 refs., 2 figs., 1 tab.

  12. Pulmonary response to exposure to ozone of emphysematous rats

    SciTech Connect

    Yokoyama, E.; Nambu, Z.; Ichikawa, I.; Uchiyama, I.; Arakawa, H.

    1987-02-01

    Rats were treated with a single intratracheal instillation of 6.5 units elastase or normal saline. Seven weeks after treatment, the animals were exposed for 24 hr to filtered air or 1 ppm O3, and their lung functions were measured. The exposure to O3 resulted in functional changes depending mainly on peripheral airway obstruction, and the direction and degree of those functional changes were in general similar between the saline- and elastase-treated animals. Another group of saline- or elastase-treated rats were exposed to 3 ppm O3 for 3 hr and the edematous response of their lungs was again similar. These results indicate that elastase-treated lungs responded to the exposure to O3 in a fashion similar to normal lungs in rats, but lung damage caused by the exposure to O3 superimposed over preexisting emphysematous damage, resulted in an additional lessening of the margin of pulmonary reserve capacity.

  13. Growth response of Pinus ponderosa seedlings and mature tree branches to acid rain and ozone exposure

    SciTech Connect

    Anderson, P.D.; Houpis, J.L.J.; Helms, J.A.

    1994-10-01

    Forests of the central and southern Sierra Nevada in California have been subjected to chronic damage by ozone and other atmospheric pollutants for the past several decades. Until recently, pollutant exposure of northern Sierra Nevada forests has been mild but increasing population and changes in land use throughout the Sacramento Valley and Sierra Nevada foothills may lead to increased pollutant damage in these forests. Although, better documented in other regions of the United States, little is known regarding the potential for acidic precipitation damage to Sierra Nevada forests. Only recently have studies directed towards understanding the potential interactive effects of ozone and acidic precipitation been undertaken. A key issue in resolving potential regional impacts of pollutants on forests is the extent to which research results can be scaled across genotypes and life-stages. Most of the pollution research to date has been performed using seedlings with varying degrees of genetic control. It is important to determine if the results obtained in such studies can be extrapolated to mature trees and to different genetic sources. In this paper, we present results from a one-year study examining the interactive effects of foliar exposure to acidic rain and ozone on the growth of ponderosa pine (Pinus ponderosa), a conifer known to be sensitive to ozone. The response to pollutants is characterized for both seedlings and mature tree branches of three genotypes grown in a common environment.

  14. Providing perspective for interpreting cardiovascular mortality risks associated with ozone exposures.

    PubMed

    Petito Boyce, Catherine; Goodman, Julie E; Sax, Sonja N; Loftus, Christine T

    2015-06-01

    When identifying standards for air pollutants based on uncertain evidence, both science and policy judgments play critical roles. Consequently, critical contextual factors are important for understanding the strengths, limitations, and appropriate interpretation of available science, and potential benefits of risk mitigation alternatives. These factors include the relative magnitude and certainty of the risks posed by various factors and the impacts of other risk factors on air pollutant epidemiology study findings. This commentary explores ozone's status as a risk factor for cardiovascular mortality in contrast with decades of strong and consistent evidence for other established risk factors. By comparison, the ozone evidence is less conclusive, more heterogeneous, and subject to substantial uncertainty; ozone's potential effects, if any, are small and challenging to discern. Moreover, the absence of a demonstrated causal relationship calls into question efforts to quantify cardiovascular mortality risks attributed to ozone exposures on a population level and highlights the need to explicitly acknowledge this uncertainty if such calculations are performed. These concerns are relevant for other similar policy contexts - where multiple established risk factors contribute to the health impact of interest; exposure-effect associations are relatively small, weak, and uncertain; and a causal relationship has not been clearly established. PMID:25817736

  15. Source contributions to seasonal vegetative exposure to ozone in the US

    NASA Astrophysics Data System (ADS)

    Lapina, K.; Henze, D. K.; Milford, J.; Huang, M.; Lin, M.; Pfister, G.; Emmons, L. K.; Fiore, A. M.; Boynard, A.; Carmichael, G. R.; Sandiford, V.; Herrick, J. D.; Dutton, S.; Smith, T.; Porter, E. M.

    2012-12-01

    Frequent exposure to high levels of ozone leads to vegetation damage and can result in substantial economic losses. A cumulative ozone exposure metric, W126, has been considered by the US EPA for use as a secondary ozone standard. Information on source regions contributing to the non-attainment of this standard is crucial for developing a successful strategy to mitigate the negative effects of ozone on vegetation. In this work we quantify W126 source contributions for the US regions exceeding selected levels of the W126 standard by applying several source attribution techniques, including "tagging", emissions perturbation and adjoint sensitivity analysis, to a suite of five global and regional chemical transport models. We estimate the W126 North American background (defined as the W126 levels in the absence of North American anthropogenic emissions) and separate source contributions by sector and country of origin. Our calculations are performed for two periods in 2008 and 2010 and are compared to the W126 observations from the Air Quality System and CASTNET. Given that the W126 metric is highly non-linear, we discuss the pros and cons of the applied source attribution methods and the applicability of the results.

  16. Respiratory responses of subjects with allergic rhinitis to ozone exposure and their relationship to nonspecific airway reactivity

    SciTech Connect

    McDonnell, W.F.; Horstman, D.H.; Abdul-Salaam, S.; Raggio, L.J.; Green, J.A.

    1987-12-01

    Ozone exposure in man produces changes in respiratory function and symptoms. There is a large degree of unexplained intersubject variability in the magnitude of these responses. There is concern that individuals with chronic respiratory diseases may also be more responsive to ozone than normal individuals. The purpose of this study was to describe the responses of subjects with allergic rhinitis to ozone exposure and to compare these responses to those previously observed in normal individuals. A further purpose was to measure the association of baseline nonspecific airway reactivity with changes in lung function and respiratory symptoms following ozone exposure. A group of 26 nonasthmatic subjects with allergic rhinitis performed a bronchial inhalation challenge with histamine and subsequently underwent two hour exposures to both clean air and to 0.18 part per million ozone with alternating periods of rest and heavy exercise. The airway reactivity of this group of subjects was no greater than that of a comparable group of subjects without allergic rhinitis. The respiratory responses of these subjects to ozone exposure were similar to those previously reported for subjects without allergic rhinitis with the exception that the allergic rhinitis subjects appeared to have a modestly increased bronchoconstrictor response compared to normals. Furthermore, we observed no significant relationships between nonspecific airway reactivity and response to ozone as measured by changes in lung function or the induction of symptoms.

  17. A Genome-Wide mRNA Expression Profile in Caenorhabditis elegans under Prolonged Exposure to 1750MHz Radiofrequency Fields

    PubMed Central

    Gao, Dawen; Yu, Zhoulong; Wu, Tongning; Zhang, Chenggang

    2016-01-01

    Objective C. elegans has been used as a biomonitor for microwave-induced stress. However, the RF (radiofrequency) fields that have been used in previous studies were weak (≤1.8W/kg), and the bio-effects on C. elegans were mostly negative or ambiguous. Therefore, this study used more intense RF fields (SAR = 3W/kg) and longer time course of exposure (60h at 25°C, L1 stage through adult stage) to investigate the biological consequences of 1750 MHz RF fields in wild-type worms. Methods The growth rates and lifespans of RF-exposure group and the control group were carefully recorded. RNA samples were collected at L4 (35h) and gravid adult (50h) stages for further high-throughput sequencing, focusing on differences between the RF-exposure and the sham control groups. Results The RF-exposed and sham control groups developed at almost the same rate and had similar longevity curves. In L4 stage worms, 94 up-regulated and 17 down-regulated genes were identified, while 186 up-regulated and 3 down-regulated genes were identified in adult stage worms. GO analysis showed that the differentially expressed genes at 35h were associated with growth, body morphogenesis and collagen and cuticle-based development. Genes that were linked to growth rate and reproductive development were differentially expressed at 50h. Some embryonic and larval development genes in the offspring were also differentially expressed at 50h. Ten genes were differentially expressed at both 35h and 50h, most of which were involved in both embryonic and larval developmental processes. Although prolonged RF fields did not induce significant temperature increase in RF exposure groups, the temperature inside worms during exposure was unknown. Conclusions No harmful effects were observed in prolonged exposure to 1750 MHz RF fields at SAR of 3W/kg on development and longevity of C. elegans. Although some differentially expressed genes were found after prolonged RF exposure, these differences were ascribed to

  18. Inflammatory Cytokines and White Blood Cell Counts Response to Environmental Levels of Diesel Exhaust and Ozone Inhalation Exposures

    EPA Science Inventory

    Epidemiological observations of urban inhalation exposures to diesel exhaust (DE) and ozone (O3) have shown pre-clinical cardiopulmonary responses in humans. Identifying the key biological mechanisms that initiate these health bioindicators is difficult due to variability in envi...

  19. The effect of ozone exposure on the dispersion of inhaled aerosol boluses in healthy human subjects

    SciTech Connect

    Keefe, M.J.; Bennett, W.D.; DeWitt, P.; Seal, E.; Strong, A.A.; Gerrity, T.R. )

    1991-07-01

    Acute exposure of humans to low levels of ozone are known to cause decreases in FVC and increases in SRaw. These alterations in lung function do not, however, elucidate the potential for acute small airway responses. In this study we employed a test of aerosol dispersion to examine the potential effects of ozone on small airways in humans. Twenty-two healthy nonsmoking male volunteers were exposed to 0.4 ppm ozone for 1 h while exercising at 20 L/min/m2 body surface area. Before and immediately after exposure, tests of spirometry (FVC, FEV1, and FEF25-75) and plethysmography (Raw and SRaw) were performed. Subjects also performed an aerosol dispersion test before and after exposure. Each test involved a subject inhaling five to seven breaths of a 300-ml bolus of a 0.5 micron triphenyl phosphate aerosol injected into a 2-L tidal volume. The bolus was injected into the tidal breath at three different depths: at Depth A the bolus was injected after 1.6 L of clean air were inhaled from FRC, at Depth B after 1.2 L, and at Depth C after 1.2 L but with inhalation beginning from RV. The primary measure of bolus dispersion was the expired half-width (HW). Secondary measures were the ratio (expressed as percent) of peak exhaled aerosol concentration to peak inhaled concentration (PR), shift in the median bolus volume between inspiration and expiration (VS), and percent of total aerosol recovered (RC). Changes in pulmonary function after ozone exposure were consistent with previous findings.

  20. Effect of ozone exposure on the dispersion of inhaled aerosol boluses in healthy human subjects

    SciTech Connect

    Keefe, M.J.; Bennett, W.D.; Dewitt, P.; Seal, E.; Strong, A.A.

    1990-12-06

    Acute exposure of humans to low levels of ozone are known to cause decreases FVC and increases sRaw. These alterations in lung function do not, however, elucidate the potential for acute small airways responses. In the study the authors employed a test of aerosol dispersion to examine the potential effects of ozone on small airways in humans. Twenty-two healthy non-smoking male volunteers were exposed to 0.4 ppm ozone for one hour while exercising at 20 l/min/m{sup 2} (BSA). Prior to and immediately following exposure, tests of spirometry (FVC, FEV1, and FEF25-75) and plethysmography (Raw and sRaw) were performed. Subjects also performed an aerosol dispersion test before and after exposure. Each test involved a subject inhaling five to seven breaths of a 300 ml bolus of a 0.5 micrometers triphenyl phosphate (TPP) aerosol injected into a 2 liters tidal volume. The bolus was injected into the tidal breath at three different depths: at depth A the bolus was injected after 1.6 liters of clean air was inhaled from FRC; at depth B after 1.2 liters; and at depth C after 1.2 liters but with inhalation beginning from RV. The primary measure of bolus dispersion was the expired half-width (HW).

  1. Ozone Exposure of Macrophages Induces an Alveolar Epithelial Chemokine Response through IL-1α

    PubMed Central

    Manzer, Rizwan; Dinarello, Charles A.; McConville, Glen; Mason, Robert J.

    2008-01-01

    Ozone is known to produce an acute influx of neutrophils, and alveolar epithelial cells can secrete chemokines and modulate inflammatory processes. However, direct exposure of alveolar epithelial cells and macrophages to ozone (O3) produces little chemokine response. To determine if cell–cell interactions might be responsible, we investigated the effect of alveolar macrophage–conditioned media after ozone exposure (MO3CM) on alveolar epithelial cell chemokine production. Serum-free media were conditioned by exposing a rat alveolar macrophage cell line NR8383 to ozone for 1 hour. Ozone stimulated secretion of IL-1α, IL-1β, and IL-18 from NR8383 cells, but there was no secretion of chemokines or TNF-α. Freshly isolated type II cells were cultured, so as to express the biological markers of type I cells, and these cells are referred to as type I–like cells. Type I–like cells were exposed to diluted MO3CM for 24 hours, and this conditioned medium stimulated secretion of cytokine-induced neutrophil chemattractant-1 (CXCL1) and monocyte chemoattractant protein-1 (CCL2). Secretion of these chemokines was inhibited by the IL-1 receptor antagonist. Although both recombinant IL-1α and IL-1β stimulated alveolar epithelial cells to secrete chemokines, recombinant IL-1α was 100-fold more potent than IL-1β. Furthermore, neutralizing anti-rat IL-1α antibodies inhibited the secretion of chemokines by alveolar epithelial cells, whereas neutralizing anti-rat IL-1β antibodies had no effect. These observations indicate that secretion of IL-1α from macrophages stimulates alveolar epithelial cells to secrete chemokines that can elicit an inflammatory response. PMID:17901407

  2. Effect of acute ozone exposure on the proteinase-antiproteinase balance in the rat lung

    SciTech Connect

    Pickrell, J.A.; Gregory, R.E.; Cole, D.J.; Hahn, F.F.; Henderson, R.F.

    1987-04-01

    Lung disease may result from a persisting proteinase excess or a depletion of antiproteinase in pulmonary parenchyma. We investigated the in vivo effect of a 48-hr exposure to ozone at 0.5, 1.0, or 1.5 ppm on proteinase and antiproteinase activity of rat lungs. Elastase inhibitory capacities of serum, lung tissue, and airway washings were measured as indicators of antielastase activity. Trypsin inhibitory capacity was measured using an esterolytic procedure. Proteinase was measured as radioactive release from a /sup 14/C-globin substrate. The 48-hr exposures to O/sub 3/ at levels up to 1 ppm produced concentration-dependent decreases of 35-80% of antiproteinase activities in serum and in lung tissue. However, exposure to 1.5 ppm O/sub 3/ resulted in no decrease in antiproteinase activities. Acid proteinase activities (pH 4.2) were increased 65-120% by exposure to 1 or 1.5 ppm O/sub 3/, which correlated with inflammatory cells noted histologically. At 1.5 ppm O/sub 3/, pulmonary edema and hemorrhage were noted in histologic sections. These changes led to a flooding of the alveoli with up to 40 times normal protein levels and a greater than fivefold increase in airway antiproteinase. These data suggest that serum and soluble lung tissue antiproteinase activity decreased upon exposure to low levels of ozone. However, if O/sub 3/ exposure is high enough to produce pulmonary hemorrhage, antiproteinase may increase following serum exudation. These changes may be important in the development of ozone-induced lung diseases, especially emphysema.

  3. Effect of acute ozone exposure on the proteinase-antiproteinase balance in the rat lung.

    PubMed

    Pickrell, J A; Gregory, R E; Cole, D J; Hahn, F F; Henderson, R F

    1987-04-01

    Lung disease may result from a persisting proteinase excess or a depletion of antiproteinase in pulmonary parenchyma. We investigated the in vivo effect of a 48-hr exposure to ozone at 0.5, 1.0, or 1.5 ppm on proteinase and antiproteinase activity of rat lungs. Elastase inhibitory capacities of serum, lung tissue, and airway washings were measured as indicators of antielastase activity. Trypsin inhibitory capacity was measured using an esterolytic procedure. Proteinase was measured as radioactive release from a 14C-globin substrate. The 48-hr exposures to O3 at levels up to 1 ppm produced concentration-dependent decreases of 35-80% of antiproteinase activities in serum and in lung tissue. However, exposure to 1.5 ppm O3 resulted in no decrease in antiproteinase activities. Acid proteinase activities (pH 4.2) were increased 65-120% by exposure to 1 or 1.5 ppm O3, which correlated with inflammatory cells noted histologically. At 1.5 ppm O3, pulmonary edema and hemorrhage were noted in histologic sections. These changes led to a flooding of the alveoli with up to 40 times normal protein levels and a greater than fivefold increase in airway antiproteinase. These data suggest that serum and soluble lung tissue antiproteinase activity decreased upon exposure to low levels of ozone. However, if O3 exposure is high enough to produce pulmonary hemorrhage, antiproteinase may increase following serum exudation. These changes may be important in the development of ozone-induced lung diseases, especially emphysema. PMID:3549351

  4. Effect of ozone exposure on the electrical characteristics of high-purity, large-diameter semiconducting carbon nanotubes.

    PubMed

    Gao, Jia; Loo, Yueh-Lin

    2014-06-14

    In this study, we have elucidated the interactions between ozone and carbon nanotubes by monitoring the characteristics of field-effect transistors based on polymer-sorted, large-diameter semiconducting carbon nanotubes. The drain-source current of these transistors initially increases with ozone exposure and then it progressively decreases with increasing exposure beyond 3 min. This non-monotonic dependence of the drain-source current can be ascribed to two competing processes. At short ozone exposure, p-doping of carbon nanotubes dominates; the drain-source current thus increases as a result of increasing hole concentration. This effect is most evidenced in a progressive threshold voltage shift towards positive voltages with increasing exposure to ozone. At extended ozone exposure, chemical oxidation of carbon nanotubes instead dominates. The drain-source current decreases as a result of decreasing hole mobility. This effect manifests itself in a monotonic decrease in the mobility of these devices as a function of ozone exposure. PMID:24760174

  5. A morphological study of the effects of ozone on rat lung. I. Short-term exposure.

    PubMed

    Hiroshima, K; Kohno, T; Owada, H; Hayashi, Y

    1987-12-01

    In order to determine the effects of ozone on lungs and the course of cell renewal after damage, young male rats were exposed to 3 ppm of ozone for 4 hr. They were killed at 1, 6, 12, and 18 hr and 1, 2, 3, 4, 7, and 14 days after exposure. One hour before the killing, dividing cells were labeled with tritiated thymidine. Type 1 cells of centriacinar location and bronchiolar cells were severely damaged after exposure. Labeling indices of type 2 cells and bronchiolar nonciliated cells increased 1 day after exposure. Hyperplasia of type 2 cells and bronchiolar nonciliated cells was observed 2 and 3 days after exposure. Ciligenesis of bronchiolar ciliated cells occurred 4 days after exposure. Our study shows that injured type 1 cells are repaired by proliferation of type 2 cells and that injured bronchiolar ciliated and Clara cells are repaired by proliferation of bronchiolar nonciliated cells. These undifferentiated cells are probably progenitors of ciliated cells and Clara cells, and some nonciliated cells are in a transitional form between nonciliated and type 2 cells. PMID:3678465

  6. Assessing ozone exposure for epidemiological studies in Malmö and Umeå, Sweden

    NASA Astrophysics Data System (ADS)

    Malmqvist, E.; Olsson, D.; Hagenbjörk-Gustafsson, A.; Forsberg, B.; Mattisson, K.; Stroh, E.; Strömgren, M.; Swietlicki, E.; Rylander, L.; Hoek, G.; Tinnerberg, H.; Modig, L.

    2014-09-01

    Ground level ozone [ozone] is considered a harmful air pollutant but there is a knowledge gap regarding its long term health effects. The main aim of this study is to develop local Land Use Regression [LUR] models that can be used to study long term health effects of ozone. The specific aim is to develop spatial LUR models for two Swedish cities, Umeå and Malmö, as well as a temporal model for Malmö in order to assess ozone exposure for long term epidemiological studies. For the spatial model we measured ozone, using Ogawa passive samplers, as weekly averages at 40 sites in each study area, during three seasons. This data was then inserted in the LUR-model with data on traffic, land use, population density and altitude to develop explanatory models of ozone variation. To develop the temporal model for Malmö, hourly ozone data was aggregated into daily means for two measurement stations in Malmö and one in a rural area outside Malmö. Using regression analyses we inserted meteorological variables into different temporal models and the one that performed best for all three stations was chosen. For Malmö the LUR-model had an adjusted model R2 of 0.40 and cross validation R2 of 0.17. For Umeå the model had an adjusted model R2 of 0.67 and cross validation adjusted R2 of 0.48. When restricting the model to only including measuring sites from urban areas, the Malmö model had adjusted model R2 of 0.51 (cross validation adjusted R2 0.33) and the Umeå model had adjusted model R2 of 0.81 (validation adjusted R2 of 0.73). The temporal model had adjusted model R2 0.54 and 0.61 for the two Malmö sites, the cross validation adjusted R2 was 0.42. In conclusion, we can with moderate accuracy, at least for Umeå, predict the spatial variability, and in Malmö the temporal variability in ozone variation.

  7. Characterization of anxiety-related responses in male rats following prolonged exposure to therapeutic doses of oral methylphenidate.

    PubMed

    Britton, Gabrielle B; Bethancourt, José A

    2009-10-01

    Increases in the rates of attention-deficit/hyperactivity disorder (ADHD) diagnosis and the prescribed use of methylphenidate (MPH) in recent years have raised concerns over the potential effects of early MPH exposure on brain structure and function in adulthood. Animal studies have shown that long-term MPH exposure can modify anxiety-related behaviors and related neural circuitry in adulthood. The present study employed a battery of behavioral tests and repeated testing to assess the long-term effects of MPH exposure on anxious responding. Male Wistar rats beginning on post-natal day 27 were exposed to 4 or 7 weeks of twice daily MPH administration at doses of 2, 3, or 5 mg/kg. MPH was administered orally and on weekdays only in order to approximate drug treatment in clinical populations. Behavioral testing began 18 days following the last drug administration. Our results indicate that prolonged oral MPH treatment at therapeutic doses has little or no enduring effects on anxious behaviors. However, a comparison of MPH groups that received treatment for 4 or 7 weeks suggests that the two treatment periods influenced anxious behaviors in observably different manners in adulthood; namely, a more prolonged period of exposure produced less anxiety relative to the shorter period of MPH exposure as indicated by behaviors in the light-dark transition, elevated plus-maze, and fear conditioning tests. These findings were interpreted as evidence of the importance of considering length of drug exposure in pre-clinical studies aimed at investigating the effects of MPH exposure in ADHD populations. PMID:19540871

  8. Cellular kinetics in the lungs of aging Fischer 344 rats after acute exposure to ozone.

    PubMed Central

    Vincent, R.; Adamson, I. Y.

    1995-01-01

    Lung repair in aging Fischer 344 male rats was investigated after an acute inhalation exposure to ozone. Adult (9-month-old) and senescent (24-month-old) rats were exposed to 0.8 ppm ozone for a single period of 6 hours, and thereafter studied over 5 days of recovery in clean air. The animals were given intraperitoneal injections of colchicine and [3H]thymidine, 4 hours and 1.5 hours before termination, respectively. The lungs were inflated with glutaraldehyde, and tissue samples were embedded in epoxy resin for electron microscopy, or in glycol methacrylate for light-microscopic autoradiography. Exposure to ozone produced epithelial injury in alveolar ducts and terminal bronchioles, later reflected by the transient increase in mitotic activity of nonciliated bronchiolar cells and alveolar type 2 cells. The increase in metaphase-arrested cells and [3H]thymidine-labeled cells in bronchioles followed similar time courses, ie, maximal at days 1.5 to 2, and subsiding by day 3. In the alveoli, type 1 cell necrosis was observed early after exposure (6 hours recovery), without notable structural changes in the interstitial and endothelial compartments. The increased mitotic activity in the alveolar septa was mostly due to proliferation of epithelial type 2 cells, which was maximal at day 1.5, and of interstitial cells, maximal at day 2.5. The magnitude of the mitotic responses of nonciliated bronchiolar cells, alveolar type 2 cells and interstitial cells was highest (+50%) in the lungs of senescent rats. Although the cellular events during repair are essentially similar in both age groups, the results indicate that senescent rats have a significantly higher level of initial injury from inhalation of ozone than adult animals. Images Figure 1 Figure 2 Figure 5 PMID:7717445

  9. Ozone

    SciTech Connect

    Not Available

    1988-06-01

    The author discusses the debate over whether concern about a hole in the ozone layer in Antarctic is real or science fiction. There is a growing consensus that efforts must be taken to protect the ozone layer. The issue now is not whether chlorofluorocarbons (CFCs) should be controlled and regulated but how much and how soon. The United States has urged that the production of dangerous CFCs, and any other chemicals that affect the ozone layer, be restricted immediately to current levels and that their use be reduced 95 percent over the next decade. The American position was too strong for many European nations and the Japanese. Negotiations at an international conference on the matter broke down. The breakdown is due in part to a more acute concern for environmental matters in the United States than exists in many countries. Meanwhile CFCs are linked to another environmental problem that equally threatens the world - the Greenhouse Effect. The earth is in a natural warming period, but man could be causing it to become even warmer. The Greenhouse Effect could have a catastrophic impact on mankind, although nothing has been proven yet.

  10. Ozone-exposure and annealing effects on graphene-on-SiO2 transistors

    NASA Astrophysics Data System (ADS)

    Zhang, E. X.; Newaz, A. K. M.; Wang, B.; Zhang, C. X.; Fleetwood, D. M.; Bolotin, K. I.; Schrimpf, R. D.; Pantelides, S. T.; Alles, M. L.

    2012-09-01

    We employ resistance measurements and Raman spectroscopy to investigate the effects of UV ozone (UVO) exposure and Ar annealing on graphene-on-SiO2 transistors. Shorter UVO exposures lead to oxygen adsorption and doping; longer exposures lead to significant defect generation and then to etching. Elevated-temperature Ar annealing following UVO exposure leads to local defect healing, as shown by the evolution of the characteristic Raman D- and G-peaks. In striking contrast, the overall graphene transistor resistance increases significantly due to void formation. Density functional calculations show that carbon-oxygen reactions lead to efficient consumption and release of C atoms (as CO or CO2) under conditions of high surface oxygen concentration.

  11. Ozone exposure increases eosinophilic airway response induced by previous allergen challenge.

    PubMed

    Vagaggini, Barbara; Taccola, Mauro; Cianchetti, Silvana; Carnevali, Stefano; Bartoli, Maria Laura; Bacci, Elena; Dente, Federico L; Di Franco, Antonella; Giannini, Daniele; Paggiaro, Pier Luigi

    2002-10-15

    We investigated whether exposure to ozone (O(3)) 24 hours after an allergen challenge test would increase airway eosinophilia induced by allergen in subjects with mild asthma with late airway response. Twelve subjects with mild atopic asthma participated in a randomized, single-blind study. Subjects underwent allergen challenge 24 hours before a 2 hour exposure to O(3) (0.27 ppm) or filtered air. Pulmonary function was monitored during the allergen challenge and after the exposure to O(3) or air. Six hours later, induced sputum was collected. After 4 weeks, the experiment was repeated with the same subjects. Allergen induced a comparable late airway response in both challenges. O(3) exposure induced a significant decrease in FVC, FEV(1), and vital capacity, and was associated with a significant increase in total symptom score compared with air exposure. The percentage of eosinophils, but not the percentage of neutrophils, in induced sputum was significantly higher after exposure to O(3) than after exposure to air (p = 0.04). These results indicate that O(3) exposure after a late airway response elicited by allergen challenge can potentiate the eosinophilic inflammatory response induced by the allergen challenge itself in subjects with mild atopic asthma. This observation may help explain the synergistic effect of air pollution and allergen exposure in the exacerbation of asthma. PMID:12379550

  12. Autonomic Effects of Controlled Fine Particulate Exposure in Young Healthy Adults: Effect Modification by Ozone

    PubMed Central

    Fakhri, Asghar A.; Ilic, Ljubomir M.; Wellenius, Gregory A.; Urch, Bruce; Silverman, Frances; Gold, Diane R.; Mittleman, Murray A.

    2009-01-01

    Background Human controlled-exposure studies have assessed the impact of ambient fine particulate matter on cardiac autonomic function measured by heart rate variability (HRV), but whether these effects are modified by concomitant ozone exposure remains unknown. Objective In this study we assessed the impact of O3 and particulate matter exposure on HRV in humans. Methods In a crossover design, 50 subjects (19–48 years of age) were randomized to 2-hr controlled exposures to filtered air (FA), concentrated ambient particles (CAPs), O3, or combined CAPs and ozone (CAPs + O3). The primary end point was change in HRV between the start and end of exposure. Secondary analyses included blood pressure (BP) responses, and effect modification by asthmatic status. Results Achieved mean CAPs and O3 exposure concentrations were 121.6 ± 48.0 μg/m3 and 113.9 ± 6.6 ppb, respectively. In a categorical analysis, exposure had no consistent effect on HRV indices. However, the dose–response relationship between CAPs mass concentration and HRV indices seemed to vary depending on the presence of O3. This heterogeneity was statistically significant for the low-frequency component of HRV (p = 0.02) and approached significance for the high-frequency component and time-domain measures of HRV. Exposure to CAPs + O3 increased diastolic BP by 2.0 mmHg (SE, 1.2; p = 0.02). No other statistically significant changes in BP were observed. Asthmatic status did not modify these effects. Conclusion The potentiation by O3 of CAPs effects on diastolic BP and possibly HRV is of small magnitude in young adults. Further studies are needed to assess potential effects in more vulnerable populations. PMID:19672410

  13. The inoculating role of previous exposure to potentially traumatic life events on coping with prolonged exposure to rocket attacks: A lifespan perspective.

    PubMed

    Palgi, Yuval; Gelkopf, Marc; Berger, Rony

    2015-06-30

    Relatively little research have addressed the effect of prolonged exposure to rocket attacks with a lifespan perspective and only a handful of these studies focused on the effect of this exposure as a function of aging. The present study examined the effects of seven years of rocket attacks fired toward the south of Israel on adult participants of different ages. We examined whether potentially traumatic life events (PTLEs) unrelated to rocket attacks moderated the association between post-traumatic stress (PTS) symptoms and age. Data were obtained from a 2007 telephone survey using the Random Digit Dialing method and including 343 individuals (76.7% participation rate). Exposure to rockets, PTLEs, global distress, and post-traumatic symptomatology were assessed. Older age was associated with a higher level of PTS symptoms. Higher PTLE levels attenuated the association between age and PTS symptoms. Our results suggest that age is a risk factor for developing PTS symptoms under prolonged exposure to rocket attacks. However, previous levels of exposure to other negative events, as well as gender, appear to inoculate a person to stress, thus modulating the age-PTS association. PMID:25863821

  14. Subacute inhalation exposure to ozone induces systemic inflammation but not insulin resistance in a diabetic mouse model.

    PubMed

    Ying, Zhekang; Allen, Katryn; Zhong, Jixin; Chen, Minjie; Williams, Keisha M; Wagner, James G; Lewandowski, Ryan; Sun, Qinghua; Rajagopalan, Sanjay; Harkema, Jack R

    2016-01-01

    Epidemiological studies suggest that diabetics may be more susceptible to the adverse health effects from exposure to high ambient concentrations of ozone, the primary oxidant gas in photochemical smog. While increased morbidity and mortality from ozone inhalation has been linked to disruption of normal cardiovascular and airway functions, potential effects on glucose and insulin homeostasis are not understood. We tested the hypothesis that ozone exposure would worsen metabolic homeostasis in KKAy mice, a genetic diabetic animal model. Male KKAy mice were exposed to 0.5 ppm ozone for 13 consecutive weekdays, and then assessed for airway, adipose and systemic inflammation, glucose homeostasis, and insulin signaling. Ozone exposure increased plasma TNFα, as well as expression of VCAM-1, iNOS and IL-6 in both pulmonary and adipose tissues. Pro-inflammatory CD11b(+)Gr-1(lo)7/4(hi) macrophages were increased by 200% in adipose tissue, but unchanged in blood. Interestingly, glucose levels were not significantly different in the insulin tolerance test between air- and ozone-exposed mice, whereas fasting insulin levels and HOMA-IR in ozone-exposed animals were significantly reduced. These changes were accompanied by increased insulin signaling in skeletal muscle and liver, but not adipose tissues. Ozone also caused decrease in body weight and plasma leptin. Our results show that in addition to marked local and systemic inflammation, ozone increases insulin sensitivity that may be related to weight loss/leptin sensitization-dependent mechanisms in KKAy mice, warranting further study on the role of hyperglycemia in mediating cardiometabolic effects of ozone inhalation. PMID:26986950

  15. Subacute Inhalation Exposure to Ozone Induces Systemic Inflammation but not Insulin Resistance in a Diabetic Mouse Model

    PubMed Central

    Ying, Zhekang; Allen, Katryn; Zhong, Jixin; Chen, Minjie; Williams, Keisha M.; Wagner, James G.; Lewandowski, Ryan; Sun, Qinghua; Rajagopalan, Sanjay; Harkema, Jack R.

    2016-01-01

    Epidemiological studies suggest that diabetics may be more susceptible to the adverse health effects from exposure to high ambient concentrations of ozone, the primary oxidant gas in photochemical smog. While increased morbidity and mortality from ozone inhalation has been linked to disruption of normal cardiovascular and airway functions, potential effects on glucose and insulin homeostasis are not understood. We tested the hypothesis that ozone exposure would worsen metabolic homeostasis in KKAy mice, a genetic diabetic animal model. Male KKAy mice were exposed to 0.5 ppm ozone for thirteen consecutive weekdays, and then assessed for airway, adipose and systemic inflammation, glucose homeostasis, and insulin signaling. Ozone exposure caused increased plasma TNFα, as well as expression of VCAM-1, iNOS and IL-6 in both pulmonary and adipose tissues. Pro-inflammatory CD11b+Gr-1lo7/4hi macrophages were increased 200% in adipose tissue but unchanged in blood. Interestingly, glucose levels were not significantly different in the insulin tolerance test between air and ozone-expose mice, whereas fasting insulin levels and HOMA-IR in ozone-exposed animals were significantly reduced. These changes were accompanied by increased insulin signaling in skeletal muscle and liver, but not adipose tissues. Ozone also caused decreases in body weight and plasma leptin. Our results show that in addition to marked local and systemic inflammation, ozone increases insulin sensitivity that may be related to weight loss/leptin sensitization-dependent mechanisms in KKAy mice, warranting further study on the role of hyperglycemia in mediating cardiometabolic effects of ozone inhalation. PMID:26986950

  16. Effects of long-term open-field ozone exposure on leaf phenolics of European silver birch (Betula pendula Roth).

    PubMed

    Saleem, A; Loponen, J; Pihlaja, K; Oksanen, E

    2001-05-01

    The response of phenolic compounds as a result of long-term low open-field ozone exposure was studied in ozone-sensitive and ozone-tolerant clones of European silver birch (Betula pendula Roth). The saplings were exposed to 1.5-1.6 times the ambient (elevated) ozone and ambient air (as control) over three growing seasons from May 1996 until August 1998. Quantification by modified Folin-Ciocalteau assay showed a 16.2% increase in total phenolics in elevated ozone plants as compared to that in controls and a corresponding 9.9% increase of 10 phenolic compounds quantified by HPLC. Five nonflavonoids and five flavonoids showed 8.4% and 11.4% increases, respectively. The phenolic results indicated slightly higher ozone sensitivity of clone 5 as compared to clone 2. The most ozone-responsive phenolic compounds in clone 2 and clone 5 were (+)-catechin (CT), chlorogenic acid (CGA), 5-p-coumaroylquinic acid (5CQA), 3-p-coumaroylquinic acid (3CQA), myricetin galactopyranoside (MG), quercetin-3-O-glucuronopyranoside (QGR), and quercetin-3-O-arabinofuranoside (QA). Increased phenolic content in ozone-exposed plants was related to impaired growth and accelerated leaf senescence, indicated by enhanced autumn leaf yellowing and lower chlorophyll and Mg content. The change in carbon allocation towards defensive phenolics at the expense of growth was greater in the ozone-sensitive clone as compared to tolerant clone. PMID:11471939

  17. Accumulated exposure to ozone and measurement of health effects in children and counselors at two summer camps

    SciTech Connect

    Berry, M.; Lioy, P.J.; Gelperin, K.; Buckler, G.; Klotz, J. )

    1991-04-01

    In the summer of 1988 a multiorganizational field health study was conducted at two summer day camps in suburban-central New Jersey. Thirty-four campers and counselors had daily pulmonary function tests performed each afternoon while attending camp during the month of July. The subjects ranged from 9 to 35 years of age. A mobile medical screening van was used to house the spirometric equipment and travel to each camp. Continuous ozone measurements were collected over the 19-test day study period. An intense ozone episode was recorded just prior to and during the first 2 weeks of the study. The campers had an increase in respiratory symptoms with increases in ozone concentrations above 120 ppb. Exposures below 120 ppb ozone were not significantly associated with symptoms. Peak expiratory flow rate in children was the only lung function measure associated with increasing ozone concentrations, with an average loss of 4.74 ml/sec/ppb (P-value = 0.05) for the 8-hr ozone exposure measure. Furthermore, it appears that the early intense exposure to ozone produced a persistent decrease in lung function and baseline shift for three days after the episode that obscured the daily dose-response relationship.

  18. Evaluation of effects of ozone exposure on influenza infection in mice using several indicators of susceptibility

    SciTech Connect

    Selgrade, M.K.; Illing, J.W.; Starnes, D.M.; Stead, A.G.; Menache, M.G.; Stevens, M.A.

    1988-07-01

    Mice were exposed to 1 ppm O3, 3 hr/day, for 5 consecutive days. Separate groups of mice were infected with influenza following each of the individual exposures. A twofold increase in the incidence of mortality and a 3-day decrease in mean survival time were observed in mice infected after the second exposure. There were no effects on percentage mortality or mean survival time due to exposure to 1 ppm O3 in mice infected after the first, third, fourth, or fifth exposure. When the exposure concentration was lowered to 0.5 ppm, there were no effects on mortality in mice infected after the second exposure. Five, daily, 3-hr exposures to 1 ppm O3 had no effect on virus titers in the lungs of mice infected after either the second or fifth exposure. In contrast, wet lung weights were significantly enhanced over infected air controls in mice infected after the second O3 exposure at both 1 and 0.5 ppm but not at 0.25 ppm exposure concentrations. This effect on lung wet weight was observed in mice infected with a dose of virus which produced 7-33% mortality in controls as well as in mice infected with a sublethal dose of virus. Histopathologic changes due to sublethal influenza infection, including nonsuppurative pneumonitis and necrosis, squamous metaplasia and hyperplasia of the epithelium lining the bronchi and bronchioles, were more severe in mice infected after the second of five, 1 ppm O3 exposure than in comparable air controls. Sublethal infection caused a loss of lung volume with secondary reduction in diffusing capability and homogenity of ventilation distribution. These latter two effects were also exacerbated in mice infected after the second of five, 1 ppm O3 exposures as compared to air controls. When mice were infected after the fifth, 1 ppm O3 exposure, there was no effect due to ozone on either lung wet weight or histopathology.

  19. Susceptibility to ozone-induced inflammation. II. Separate loci control responses to acute and subacute exposures

    SciTech Connect

    Kleeberger, S.R.; Levitt, R.C.; Zhang, L.Y. )

    1993-01-01

    We demonstrated previously that inbred strains of mice are differentially susceptible to acute (3 h) and subacute (48 h) exposures to 2 parts per million (ppm) ozone (O3) and 0.30 ppm O3, respectively. Genetic studies with O3-resistant C3H/HeJ and O3-susceptible C57BL/6J strains have indicated that susceptibility to each of these O3 exposures is under Mendelian (single gene) control. In the present study, we hypothesized that the same gene controls susceptibility to the airway inflammatory responses to 2 ppm and 0.30 ppm O3 exposures. To test this hypothesis, airway inflammation was induced in 10 BXH and 16 BXD recombinant inbred (RI) strains of mice by acute as well as subacute O3 exposures. Airway inflammation was assessed by counting the number of polymorphonuclear leukocytes (PMNs) in bronchoalveolar lavage (BAL) returns obtained immediately after 48-h subacute exposure to 0.30 ppm O3, or 6 h after 3 h acute exposure to 2 ppm O3. Each RI strain was classified as susceptible or resistant to each exposure, based on a comparison of mean numbers of PMNs with those of the respective progenitor strains. For each RI set, a phenotypic strain distribution pattern (SDP) was thus derived for each exposure regimen, and the SDPs were then compared for concordance. Among the BXH RI strains, 4 of 10 responded discordantly to the two exposures: 3 were susceptible to acute exposure and resistant to subacute exposure, whereas 1 was conversely susceptible. Among the BXD RI strains, 4 of 16 were discordant: 1 was susceptible to acute exposure, and resistant to subacute exposure, whereas 3 were conversely susceptible.

  20. Adsorption of oxygen on Au(111) by exposure to ozone

    NASA Astrophysics Data System (ADS)

    Saliba, N.; Parker, D. H.; Koel, B. E.

    1998-08-01

    Atomic oxygen coverages of up to 1.2 ML may be cleanly adsorbed on the Au(111) surface by exposure to O 3 at 300 K. We have studied the adsorbed oxygen layer by AES, XPS, HREELS, LEED, work function measurements and TPD. A plot of the O(519 eV)/Au(239 eV) AES ratio versus coverage is nearly linear, but a small change in slope occurs at ΘO=0.9 ML. LEED observations show no ordered superlattice for the oxygen overlayer for any coverage studied. One-dimensional ordering of the adlayer occurs at low coverages, and disordering of the substrate occurs at higher coverages. Adsorption of 1.0 ML of oxygen on Au(111) increases the work function by +0.80 eV, indicating electron transfer from the Au substrate into an oxygen adlayer. The O(1s) peak in XPS has a binding energy of 530.1 eV, showing only a small (0.3 eV) shift to a higher binding energy with increasing oxygen coverage. No shift was detected for the Au 4f 7/2 peak due to adsorption. All oxygen is removed by thermal desorption of O 2 to leave a clean Au(111) surface after heating to 600 K. TPD spectra initially show an O 2 desorption peak at 520 K at low ΘO, and the peak shifts to higher temperatures for increasing oxygen coverages up to ΘO=0.22 ML. Above this coverage, the peak shifts very slightly to higher temperatures, resulting in a peak at 550 K at ΘO=1.2 ML. Analysis of the TPD data indicates that the desorption of O 2 from Au(111) can be described by first-order kinetics with an activation energy for O 2 desorption of 30 kcal mol -1 near saturation coverage. We estimate a value for the Au-O bond dissociation energy D(Au-O) to be ˜56 kcal mol -1.

  1. Ozone and limonene in indoor air: a source of submicron particle exposure.

    PubMed Central

    Wainman, T; Zhang, J; Weschler, C J; Lioy, P J

    2000-01-01

    overall particle exposure. This study provides data for assessing the impact of outdoor ozone on indoor particles. This is important to determine the efficacy of the mass-based particulate matter standards in protecting public health because the indoor secondary particles can vary coincidently with the variations of outdoor fine particles in summer. PMID:11133393

  2. Relative axial myopia induced by prolonged light exposure in C57BL/6 mice.

    PubMed

    Zhou, Xiangtian; An, Jianhong; Wu, Xiaomin; Lu, Runxia; Huang, Qinzhu; Xie, Ruozhong; Jiang, Liqin; Qu, Jia

    2010-01-01

    Ambient lighting is essential for ocular development in many species, however, disruption in diurnal lighting cycle can affect the development in refraction and axial growth of the eye. This study investigated the effects of prolonged daily lighting on refraction and various optical components of the eye by raising C57BL/6 mice under three different light/dark cycles (18/6, 12/12 and 6/18). Egr-1 mRNA expression, apoptosis and histology of the retina and size of the scleral fibrils were evaluated in these three lighting cycles. Results showed that there was a trend of myopic development, increasing vitreous chamber depth and thinning of the retina in eyes from 6/18 to 18/6 groups. Retinal Egr-1 mRNA expression and diameter of scleral fibrils were reduced with the prolongation of daily lighting from 6/18 to 18/6. However, retinal apoptosis was not detected in all the groups. These results suggest that prolonged lighting can induce axial myopia in inbred mice. This model, which uses mice with similar genetic backgrounds, provides an alternative to the currently available models and therefore is useful for evaluation of refractive errors caused by changes in environmental illumination. PMID:19912561

  3. Early Life Ozone Exposure Results in Dysregulated Innate Immune Function and Altered microRNA Expression in Airway Epithelium

    PubMed Central

    Gerriets, Joan E.; Wang, Theodore T.; Postlethwait, Edward M.; Evans, Michael J.; Fontaine, Justin H.; Miller, Lisa A.

    2014-01-01

    Exposure to ozone has been associated with increased incidence of respiratory morbidity in humans; however the mechanism(s) behind the enhancement of susceptibility are unclear. We have previously reported that exposure to episodic ozone during postnatal development results in an attenuated peripheral blood cytokine response to lipopolysaccharide (LPS) that persists with maturity. As the lung is closely interfaced with the external environment, we hypothesized that the conducting airway epithelium of neonates may also be a target of immunomodulation by ozone. To test this hypothesis, we evaluated primary airway epithelial cell cultures derived from juvenile rhesus macaque monkeys with a prior history of episodic postnatal ozone exposure. Innate immune function was measured by expression of the proinflammatory cytokines IL-6 and IL-8 in primary cultures established following in vivo LPS challenge or, in response to in vitro LPS treatment. Postnatal ozone exposure resulted in significantly attenuated IL-6 mRNA and protein expression in primary cultures from juvenile animals; IL-8 mRNA was also significantly reduced. The effect of antecedent ozone exposure was modulated by in vivo LPS challenge, as primary cultures exhibited enhanced cytokine expression upon secondary in vitro LPS treatment. Assessment of potential IL-6-targeting microRNAs miR-149, miR-202, and miR-410 showed differential expression in primary cultures based upon animal exposure history. Functional assays revealed that miR-149 is capable of binding to the IL-6 3′ UTR and decreasing IL-6 protein synthesis in airway epithelial cell lines. Cumulatively, our findings suggest that episodic ozone during early life contributes to the molecular programming of airway epithelium, such that memory from prior exposures is retained in the form of a dysregulated IL-6 and IL-8 response to LPS; differentially expressed microRNAs such as miR-149 may play a role in the persistent modulation of the epithelial innate

  4. Oxidative stress-dependent changes in immune responses and cell death in the substantia nigra after ozone exposure in rat.

    PubMed

    Rivas-Arancibia, Selva; Zimbrón, Luis Fernando Hernández; Rodríguez-Martínez, Erika; Maldonado, Perla D; Borgonio Pérez, Gabino; Sepúlveda-Parada, María

    2015-01-01

    Parkinson's disease has been associated with the selective loss of neurons in the substantia nigra pars compacta. Increasing evidence suggests that oxidative stress plays a major role. The resulting increase in reactive oxygen species triggers a sequence of events that leads to cell damage, activation of microglia cells and neuroinflammatory responses. Our objective was to study whether chronic exposure to low doses of ozone, which produces oxidative stress itself, induces progressive cell death in conjunction with glial alterations in the substantia nigra. Animals were exposed to an ozone-free air stream (control) or to low doses of ozone for 7, 15, 30, 60, or 90 days. Each group underwent (1) spectrophotometric analysis for protein oxidation; (2) western blot testing for microglia reactivity and nuclear factor kappa B expression levels; and (3) immunohistochemistry for cytochrome c, GFAP, Iba-1, NFkB, and COX-2. Our results indicate that ozone induces an increase in protein oxidation levels, changes in activated astrocytes and microglia, and cell death. NFkB and cytochrome c showed an increase until 30 days of exposure, while cyclooxygenase 2 in the substantia nigra increased from 7 days up to 90 days of repetitive ozone exposure. These results suggest that oxidative stress caused by ozone exposure induces changes in inflammatory responses and progressive cell death in the substantia nigra in rats, which could also be occurring in Parkinson's disease. PMID:25999851

  5. Oxidative stress-dependent changes in immune responses and cell death in the substantia nigra after ozone exposure in rat

    PubMed Central

    Rivas-Arancibia, Selva; Zimbrón, Luis Fernando Hernández; Rodríguez-Martínez, Erika; Maldonado, Perla D.; Borgonio Pérez, Gabino; Sepúlveda-Parada, María

    2015-01-01

    Parkinson's disease has been associated with the selective loss of neurons in the substantia nigra pars compacta. Increasing evidence suggests that oxidative stress plays a major role. The resulting increase in reactive oxygen species triggers a sequence of events that leads to cell damage, activation of microglia cells and neuroinflammatory responses. Our objective was to study whether chronic exposure to low doses of ozone, which produces oxidative stress itself, induces progressive cell death in conjunction with glial alterations in the substantia nigra. Animals were exposed to an ozone-free air stream (control) or to low doses of ozone for 7, 15, 30, 60, or 90 days. Each group underwent (1) spectrophotometric analysis for protein oxidation; (2) western blot testing for microglia reactivity and nuclear factor kappa B expression levels; and (3) immunohistochemistry for cytochrome c, GFAP, Iba-1, NFkB, and COX-2. Our results indicate that ozone induces an increase in protein oxidation levels, changes in activated astrocytes and microglia, and cell death. NFkB and cytochrome c showed an increase until 30 days of exposure, while cyclooxygenase 2 in the substantia nigra increased from 7 days up to 90 days of repetitive ozone exposure. These results suggest that oxidative stress caused by ozone exposure induces changes in inflammatory responses and progressive cell death in the substantia nigra in rats, which could also be occurring in Parkinson's disease. PMID:25999851

  6. Prolonged tamoxifen exposure selects a breast cancer cell clone that is stable in vitro and in vivo.

    PubMed

    Sipila, P E; Wiebe, V J; Hubbard, G B; Koester, S K; Emshoff, V D; Maenpaa, J U; Wurz, G T; Seymour, R C; DeGregorio, M W

    1993-01-01

    The effects of long-term tamoxifen exposure on cell growth and cell cycle kinetics were compared between oestrogen receptor (ER)-positive (MCF-7) and ER-negative (MDA-MB-231) cell lines. In the MCF-7 cell line, prolonged tamoxifen exposure (0.5 mumol/l for > 100 days) blocked cells in G0-G1 of the cell cycle, and slowed the doubling time of cells from 30 to 59 h. These effects corresponded to an increase in the cellular accumulation of tamoxifen over time [mean area under concentration curve (AUC) = 77.92 mumoles/10(6)/cells/day]. In contrast, in the MDA-MB-231 cell line, long-term tamoxifen exposure had no obvious effect on the doubling time, and reduced cellular tamoxifen accumulation (mean AUC = 50.50 mumoles/10(6)/cells/day) compared to the MCF-7 cells. Flow cytometric analysis of MDA-MB-231 cells demonstrated that a new tetraploid clone emerged following 56 days of tamoxifen exposure. Inoculation of the MDA-MB-231 tetraploid clone and MDA-MB-231 wildtype cells into the opposite flanks of athymic nude mice resulted in the rapid growth of tetraploid tumours. The tetraploid tumours maintained their ploidy following tamoxifen treatment for nine consecutive serial transplantations. Histological examination of the fifth transplant generation xenografts revealed that the tetraploid tumour had a 25-30 times greater mass, area of haemorrhage and necrosis, a slightly higher mitotic index and was more anaplastic than the control neoplasm. The control wildtype MDA-MB-231 tumours maintained a stable ploidy following tamoxifen treatment until the eighth and ninth transplantation, when a tetraploid population appeared, suggesting that tamoxifen treatment may select for this clone in vivo. These studies suggest that prolonged tamoxifen exposure may select for new, stable, fast growing cell clones in vitro as well as in vivo. PMID:8297653

  7. Effects of Gaseous Ozone Exposure on Bacterial Counts and Oxidative Properties in Chicken and Duck Breast Meat.

    PubMed

    Muhlisin, Muhlisin; Utama, Dicky Tri; Lee, Jae Ho; Choi, Ji Hye; Lee, Sung Ki

    2016-01-01

    The effects of gaseous ozone exposure on the bacterial counts and oxidative properties were evaluated in duck and chicken breast fillets, which were stored under a continuous flux of gaseous ozone (10×10(-6) kg O3/m(3)/h) at 4±1℃ for 4 d. The ozone generator was set to on for 15 min and off for 105 min, and this cyclic timer was set during storage. Ozone effectively reduced the growth of coliform, aerobic and anaerobic bacteria in both chicken and duck breast. However, lipid oxidation occurred faster in duck breast than chicken breast with higher degree of discoloration, TBARS value, and antioxidant enzyme (glutathione peroxidase and catalase) activity decline rates. It is concluded that ozone effectively controlled the growth of bacteria in both chicken and duck breast with less effects on oxidative deterioration in chicken breast. PMID:27433112

  8. Effects of Gaseous Ozone Exposure on Bacterial Counts and Oxidative Properties in Chicken and Duck Breast Meat

    PubMed Central

    Muhlisin, Muhlisin; Utama, Dicky Tri; Lee, Jae Ho; Choi, Ji Hye; Lee, Sung Ki

    2016-01-01

    The effects of gaseous ozone exposure on the bacterial counts and oxidative properties were evaluated in duck and chicken breast fillets, which were stored under a continuous flux of gaseous ozone (10×10−6 kg O3/m3/h) at 4±1℃ for 4 d. The ozone generator was set to on for 15 min and off for 105 min, and this cyclic timer was set during storage. Ozone effectively reduced the growth of coliform, aerobic and anaerobic bacteria in both chicken and duck breast. However, lipid oxidation occurred faster in duck breast than chicken breast with higher degree of discoloration, TBARS value, and antioxidant enzyme (glutathione peroxidase and catalase) activity decline rates. It is concluded that ozone effectively controlled the growth of bacteria in both chicken and duck breast with less effects on oxidative deterioration in chicken breast. PMID:27433112

  9. Increased CCL24/eotaxin-2 with postnatal ozone exposure in allergen-sensitized infant monkeys is not associated with recruitment of eosinophils to airway mucosa

    SciTech Connect

    Chou, Debbie L.; Gerriets, Joan E.; Schelegle, Edward S.; Hyde, Dallas M.; Miller, Lisa A.

    2011-12-15

    Epidemiology supports a causal link between air pollutant exposure and childhood asthma, but the mechanisms are unknown. We have previously reported that ozone exposure can alter the anatomic distribution of CD25+ lymphocytes in airways of allergen-sensitized infant rhesus monkeys. Here, we hypothesized that ozone may also affect eosinophil trafficking to allergen-sensitized infant airways. To test this hypothesis, we measured blood, lavage, and airway mucosa eosinophils in 3-month old monkeys following cyclical ozone and house dust mite (HDM) aerosol exposures. We also determined if eotaxin family members (CCL11, CCL24, CCL26) are associated with eosinophil location in response to exposures. In lavage, eosinophil numbers increased in animals exposed to ozone and/or HDM. Ozone + HDM animals showed significantly increased CCL24 and CCL26 protein in lavage, but the concentration of CCL11, CCL24, and CCL26 was independent of eosinophil number for all exposure groups. In airway mucosa, eosinophils increased with exposure to HDM alone; comparatively, ozone and ozone + HDM resulted in reduced eosinophils. CCL26 mRNA and immunofluorescence staining increased in airway mucosa of HDM alone animals and correlated with eosinophil volume. In ozone + HDM animal groups, CCL24 mRNA and immunofluorescence increased along with CCR3 mRNA, but did not correlate with airway mucosa eosinophils. Cumulatively, our data indicate that ozone exposure results in a profile of airway eosinophil migration that is distinct from HDM mediated pathways. CCL24 was found to be induced only by combined ozone and HDM exposure, however expression was not associated with the presence of eosinophils within the airway mucosa. -- Highlights: Black-Right-Pointing-Pointer Ozone can modulate the localization of eosinophils in infant allergic airways. Black-Right-Pointing-Pointer Expression of eotaxins within the lung is affected by ozone and allergen exposure. Black-Right-Pointing-Pointer CCL24 induction by

  10. Effects of ozone exposure: a comparison between oral and nasal breathing

    SciTech Connect

    Hynes, B.; Silverman, F.; Cole, P.; Corey, P.

    1988-09-01

    Mode of inhalation, by nose or by mouth, as a determinant of pulmonary toxicity to acute inhalant exposure has been investigated incompletely. This communication addresses whether there are significant differences in toxic pulmonary responses to acute ozone (O/sub 3/) exposure between differing modes of inhalation (nasal vs. oral breathing). Changes in the results of pulmonary function tests and symptomatology of healthy young adults were compared following both exclusive nose and exclusive mouth breathing during a 30-min exposure to approximately 0.4 ppm O/sub 3/ under conditions of moderate continuous exercise. In this single-blind, randomized, crossover study, no significant differences in either the results of pulmonary function tests or in symptomatology were found between the two modes of inhalation.

  11. Transient visual effects of prolonged small spot foveal laser exposure. Report for January-March 1989

    SciTech Connect

    Zwick, H.; Robins, D.O.; Magsood, N.

    1989-03-01

    In recent experiments, the authors evaluated the effects of acute, threshold damage levels of small-spot foveal laser exposure. These experiments revealed transient changes in acuity and contrast sensitivity lasting from 10 to 15 minutes postexposure. Following recovery from such effects, normal acuity and contrast sensitivity are not necessarily degraded, although continuous exposure at these levels does result in parafoveal compensation for foveal damage and eventual deficit in fine visual acuity. Development of a test of foveal function during and after small-spot foveal exposure was the primary objective of this investigation. This objective was accomplished. At retinal damage levels, only a small focal foveal lesion was observed indicating the ability to utilize the fovea during such exposure. Post-exposure recovery effects analyzed for target size and contrast conditions suggest retinal and possibly cortical saturation processes.

  12. Increased lung resistance after diesel particulate and ozone co-exposure not associated with enhanced lung inflammation in allergic mice*

    EPA Science Inventory

    Exposure to diesel exhaust particle matter (DEP) exacerbates asthma. Likewise, similar effects have been reported with exposure to the oxidizing air pollutant ozone (03) . Since levels of both pollutants in ambient air tend to be simultaneously elevated, we investigated the possi...

  13. Effect of maternal exposure to ozone on reproductive outcome and immune, inflammatory, and allergic responses in the offspring

    EPA Science Inventory

    There is growing concern that exposure to air pollutants during pregnancy affects health outcomes in the offspring due to alterations in the development of immune and other homeostatic processes. To assess the risks of maternal inhalation exposure to ozone (O3), timed pregnant BA...

  14. FLUX DETERMINATION AND PHYSIOLOGICAL RESPONSE IN THE EXPOSURE OF RED SPRUCE TO GASEOUS HYDROGEN PEROXIDE, OZONE, AND SULFUR DIOXIDE

    EPA Science Inventory

    We report on the 3-week exposure of a branch of a forest-grown red spruce (Picea rubens) sapling to the combination of gaseous hydrogen peroxide. ozone, and sulfur dioxide. he exposure was conducted continuously using concentrations of H2O2, O3, and SO2 that have been observed du...

  15. The Variable Effects of Ozone and/or Diesel Particulate Inhalation Exposure on Allergic Airways Responses in Mice

    EPA Science Inventory

    Exposure to diesel exhaust particle matter (DEP) associated with the combustion of diesel fuel exacerbates asthma. Likewise, similar effects have been reported with exposure to the oxidizing air pollutant ozone (O3). Since levels of both pollutants in ambient air are e...

  16. Consequences of prolonged inhalation of ozone on f344/n rats: Collaborative studies. Part 3. Effects on complex carbohydrates of lung connective tissue. Research report, April 1991-January 1994

    SciTech Connect

    Radhakrishnamurthy, B.

    1994-09-01

    Glycosaminoglycans are constituents of proteoglycans, which are integral components of lung connective tissue. Changes in the metabolism of glycosaminoglycans have been noted in pulmonary fibrosis and emphysema. The authors studied quantitative and qualitative changes of glycosaminoglycans in the lungs of rats exposed to a range of ozone levels (0, 0.12, 0.5, or 1.0 parts per million) for 20 months. Although wide variations in total glycosaminoglycans concentrations exist among individual animals within each exposure group, regression analyses of data indicated a monotonic and statistically significant decrease of total glycosaminoglycans after ozone exposure. Among individual glycosaminoglycans, hyaluronan, chondroitin 4-sulfate, and chondroitin 6-sulfate levels decreased significantly in animals exposed to ozone when compared with control animals. Heparan sulfate concentration exhibited a significant trend toward increase with increasing doses of ozone, but the difference in heparan sulfate concentration animals exposed to ozone and control animals was not significant. Gel filtration studies of glycosaminoglycans in pooled sampled indicated that the molecular size of hyaluronan in animals exposed to ozone was lower than it was in control animals. The authors noted differences in heparan sulfate`s chemical properties and its affinity to antithrombin III between animals exposed to ozone and control animals. These observations indicate that inhalation of ozone for 20 months affects normal cellular metabolism of proteoglycans, which may contribute to the functional impairment of the lung.

  17. Projecting Future Changes in Seasonal Vegetative Exposure to Ozone in the Western US Using GEOS-Chem Adjoint

    NASA Astrophysics Data System (ADS)

    Lapina, K.; Henze, D. K.; Milford, J. B.

    2014-12-01

    Frequent exposure to elevated levels of ozone leads to negative impacts on ecosystems including the loss of ozone-sensitive tree species and agricultural crops in many regions of the United States. Information on emission sources contributing to these losses is crucial for developing a successful strategy to mitigate the negative effects of ozone on vegetation. A cumulative ozone exposure metric, W126, has been considered by the US EPA for use as secondary ozone standard. The rural West of the US has been demonstrated to have an especially great potential for disconnect between attaining primary versus W126-based ozone standards. In this work we separate the relative impact of emissions sources for the W126 in the Western US using forward and adjoint simulations with the global chemical transport model GEOS-Chem. The obtained source contributions are separated by different locations, species, and sectors and are combined with representative concentration pathway (RCP) anthropogenic emission scenarios to project future changes in W126 through 2050. Focusing on the foreign influences we find that the change in Chinese emissions alone is projected to lead to up to 20% increase in the W126 levels in the West and is strongly dependent on the RCP scenario. We further use concentration-response functions based on the W126 index to estimate the loss of four ozone-sensitive species in the West - ponderosa pine, Douglas Fir, red alder and quacking aspen.

  18. Low-Temperature Ozone Exposure Technique to Modulate the Stoichiometry of WO(x) Nanorods and Optimize the Electrochromic Performance

    SciTech Connect

    Lin, F.; Li, C. P.; Chen, G.; Tenent, R. C.; Wolden, C. A.; Gillaspie, D. T.; Dillon, A. C.; Richards, R. M.; Engtrakul, C.

    2012-06-29

    A low-temperature ozone exposure technique was employed for the post-treatment of WO{sub x} nanorod thin films fabricated from hot-wire chemical vapor deposition (HWCVD) and ultrasonic spray deposition (USD) techniques. The resulting films were characterized with x-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, UV-vis-NIR spectroscopy and x-ray photoelectron spectroscopy (XPS). The stoichiometry and surface crystallinity of the WO{sub x} thin films were subsequently modulated upon ozone exposure and thermal annealing without particle growth. The electrochromic performance was studied in a LiClO{sub 4}-propylene carbonate electrolyte, and the results suggest that the low-temperature ozone exposure technique is superior to the traditional high-temperature thermal annealing (employed to more fully oxidize the WO{sub x}). The optical modulation at 670 nm was improved from 35% for the as-deposited film to 57% for the film after ozone exposure at 150 C. The coloration efficiency was improved and the switching speed to the darkened state was significantly accelerated from 18.0 s for the as-deposited film to 11.8 s for the film after the ozone exposure. The process opens an avenue for low-temperature and cost-effective manufacturing of electrochromic films, especially on flexible polymer substrates.

  19. Low-temperature ozone exposure technique to modulate the stoichiometry of WOx nanorods and optimize the electrochromic performance.

    PubMed

    Lin, Feng; Li, Chi-Ping; Chen, Gang; Tenent, Robert C; Wolden, Colin A; Gillaspie, Dane T; Dillon, Anne C; Richards, Ryan M; Engtrakul, Chaiwat

    2012-06-29

    A low-temperature ozone exposure technique was employed for the post-treatment of WO(x) nanorod thin films fabricated from hot-wire chemical vapor deposition (HWCVD) and ultrasonic spray deposition (USD) techniques. The resulting films were characterized with x-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, UV-vis-NIR spectroscopy and x-ray photoelectron spectroscopy (XPS). The stoichiometry and surface crystallinity of the WO(x) thin films were subsequently modulated upon ozone exposure and thermal annealing without particle growth. The electrochromic performance was studied in a LiClO(4)-propylene carbonate electrolyte, and the results suggest that the low-temperature ozone exposure technique is superior to the traditional high-temperature thermal annealing (employed to more fully oxidize the WO(x)). The optical modulation at 670 nm was improved from 35% for the as-deposited film to 57% for the film after ozone exposure at 150 °C. The coloration efficiency was improved and the switching speed to the darkened state was significantly accelerated from 18.0 s for the as-deposited film to 11.8 s for the film after the ozone exposure. The process opens an avenue for low-temperature and cost-effective manufacturing of electrochromic films, especially on flexible polymer substrates. PMID:22653083

  20. Interaction of drought and ozone exposure on isoprene emission from extensively cultivated poplar.

    PubMed

    Yuan, Xiangyang; Calatayud, Vicent; Gao, Feng; Fares, Silvano; Paoletti, Elena; Tian, Yuan; Feng, Zhaozhong

    2016-10-01

    The combined effects of ozone (O3 ) and drought on isoprene emission were studied for the first time. Young hybrid poplars (clone 546, Populus deltoides cv. 55/56 x P. deltoides cv. Imperial) were exposed to O3 (charcoal-filtered air, CF, and non-filtered air +40 ppb, E-O3 ) and soil water stress (well-watered, WW, and mild drought, MD, one-third irrigation) for 96 days. Consistent with light-saturated photosynthesis (Asat ), intercellular CO2 concentration (Ci ) and chlorophyll content, isoprene emission depended on drought, O3 , leaf position and sampling time. Drought stimulated emission (+38.4%), and O3 decreased it (-40.4%). Ozone increased the carbon cost per unit of isoprene emission. Ozone and drought effects were stronger in middle leaves (13th-15th from the apex) than in upper leaves (6th-8th). Only Asat showed a significant interaction between O3 and drought. When the responses were up-scaled to the entire-plant level, however, drought effects on total leaf area translated into around twice higher emission from WW plants in clean air than in E-O3 . Our results suggest that direct effects on plant emission rates and changes in total leaf area may affect isoprene emission from intensively cultivated hybrid poplar under combined MD and O3 exposure, with important feedbacks for air quality. PMID:27411672

  1. Effect of ozone exposure and infection on bronchoalveolar lavage: Sex differences in response patterns.

    PubMed Central

    Gan, Xiaozhuang; Umstead, Todd M.; Haque, Rizwanul; Wang, Guirong; Floros, Joanna

    2014-01-01

    Female mice exhibit a better survival rate than males after infection, but if infection follows an ozone-induced oxidative stress, male survival exceeds that of females. Our goal was to study bronchoalveolar lavage factors that contribute to these sex differences in outcome. We studied parameters at 4, 24, and 48 hours after ozone exposure and infection, including markers of inflammation, oxidative stress, and tissue damage, and surfactant phospholipids and surfactant protein A (SP-A). A multianalyte immunoassay at the 4 hr time point measured 59 different cytokines, chemokines, and other proteins. We found that: 1) Although some parameters studied revealed sex differences, no sex differences were observed in LDH, total protein, MIP-2, and SP-A. Males showed more intragroup significant differences in SP-A between filtered air- and ozone-exposed mice compared to females. 2) Oxidized dimeric SP-A was higher in FA-exposed female mice. 3) Surfactant phospholipids were typically higher in males. 4) The multianalyte data revealed differences in the exuberance of responses under different conditions - males in response to infection and females in response to oxidative stress. These more exuberant, and presumably less well-controlled responses associate with the poorer survival. We postulate that the collective effects of these sex differences in response patterns of lung immune cells may contribute to the clinical outcomes previously observed. PMID:24769259

  2. Effect of ozone exposure and infection on bronchoalveolar lavage: sex differences in response patterns.

    PubMed

    Mikerov, Anatoly N; Phelps, David S; Gan, Xiaozhuang; Umstead, Todd M; Haque, Rizwanul; Wang, Guirong; Floros, Joanna

    2014-10-15

    Female mice exhibit a better survival rate than males after infection, but if infection follows an ozone-induced oxidative stress, male survival exceeds that of females. Our goal was to study bronchoalveolar lavage factors that contribute to these sex differences in outcome. We studied parameters at 4, 24, and 48 h after ozone exposure and infection, including markers of inflammation, oxidative stress, and tissue damage, and surfactant phospholipids and surfactant protein A (SP-A). A multianalyte immunoassay at the 4h time point measured 59 different cytokines, chemokines, and other proteins. We found that: (1) Although some parameters studied revealed sex differences, no sex differences were observed in LDH, total protein, MIP-2, and SP-A. Males showed more intragroup significant differences in SP-A between filtered air- and ozone-exposed mice compared to females. (2) Oxidized dimeric SP-A was higher in FA-exposed female mice. (3) Surfactant phospholipids were typically higher in males. (4) The multianalyte data revealed differences in the exuberance of responses under different conditions - males in response to infection and females in response to oxidative stress. These more exuberant, and presumably less well-controlled responses associate with the poorer survival. We postulate that the collective effects of these sex differences in response patterns of lung immune cells may contribute to the clinical outcomes previously observed. PMID:24769259

  3. Enhanced inflammatory response to acute ozone exposure in rats during pregnancy and lactation

    SciTech Connect

    Gunnison, A.F.; Weideman, P.A.; Sobo, M. )

    1992-11-01

    Experimental evidence from several studies suggests that pregnant animals and women are more susceptible to oxidants than nonpregnant controls. In the study reported here, we sought to determine whether pregnant rats are more sensitive than age-matched virgin females to the inflammatory effects of ozone, a gaseous oxidant of considerable environmental significance. Rats at several stages of pregnancy and lactation, as well as age-matched virgin females, were exposed to 1 ppm ozone for 6 hr. Controls were sham-exposed to pure air for an identical period of time. Bronchoalveolar lavage was performed 24 hr after the beginning of exposure, and components of the lavage fluid considered to be indicators of inflammation were used to assess the severity of pulmonary inflammation. The results of this experiment showed that significantly enhanced sensitivity to ozone-induced pulmonary inflammation develops during pregnancy, is maintained during lactation, and disappears following lactation. Implicit in this pattern of differential sensitivity in rats is the possibility of a similar pattern of inflammatory response in analogous groups of humans as well as the potential for applicability to other oxidative pollutants.

  4. The effect of prolonged exposure to 750{degree}C air on the tribological performance of PM212

    SciTech Connect

    Bemis, K.; Bogdanski, M.S.; DellaCorte, C.; Sliney, H.E.

    1994-05-01

    The effect of prolonged exposure to 750C air on tribological performance and dimensional stability of PM212, a high temperature, self-lubricating composite, is studied. PM212, contains 70% metal-bonded Cr{sub 3}C{sub 2}, 15% BaF{sub 2}/CaF{sub 2} eutectic and 15% silver. Rub blocks were fabricated from PM212 by cold isostatic pressing followed by sintering. Prior to tribo-testing, the rub blocks were exposed to 750C air from 100 to 1000 hours. Then, the rub blocks were slid against nickel-based superalloy disks in a double-rub-block tribometer in air under 66N load at temperatures from 25 to 750C with a sliding velocity of 0.36 m/s. Unexposed rub blocks were tested for baseline comparison. Friction coefficients ranged from 0.24 to 0.37 for unexposed rub blocks and from 0.32 to 0.56 for the exposed ones. Wear for both the composite blocks and superalloy disks was typically in the moderate to low range of 10{sup {minus}5} to 10{sup {minus}6} mm{sup 3} /N-m. Friction and wear data were similar for the rub blocks exposed for 100, 500, and 1000 hours. Prolonged exposure to 750C air increased friction and wear of the PM212 rub blocks at room temperature, but triboperformance remained unaffected at higher temperatures, probably due to formation of lubricous metal oxides. Dimensional stability of the composite was studied by exposing specimens of varying thicknesses for 500 hours in air at 750C. Block thicknesses were found to increase with increased exposure time until steady state was reached after 100 hours of exposure, probably due to oxidation.

  5. Effects of processing and prolonged high temperature exposure on the microstructure of Nb-1Zr-C sheet

    NASA Technical Reports Server (NTRS)

    Uz, Mehmet; Titran, R. H.

    1993-01-01

    High temperature stability of the microstructure of Nb-1Zr sheet containing 0.1 and 0.06 wt. percent C was studied as affected by processing and prolonged 1350 K exposure with and without applied stress. Sheets were fabricated by cold rolling bars that were single-, double-, or triple-extruded at 1900 K. Creep samples were double-annealed (1 h at 1755 K + 2 h at 1475 K) prior to testing at 1350 K and 10,000 - 34,500 h. The microstructures of the as-cast, extruded, rolled, DA, and crept samples were characterized using various metallographic and analytical methods. The precipitates were rather coarse Nb2C initially, but transformed to finer (less than or equal to 1 micron) carbides of (Zr, Nb)C with each subsequent high temperature process. The grain size, and the relative amount and morphology of (Zr, Nb)C were found to be affected by the number of extrusions and to some extent by C-content. However, the microstructures of all the crept samples were similar with (Zr, Nb)C distributed throughout the matrix indicating that prolonged exposure to 1350 K gave rise to complete transformation of Nb2C to (Zr, Nb)C regardless of the processing history. These and other observations are presented with the emphasis on the correlation between processing, microstructure, and creep properties.

  6. Prolonged Morphine Exposure Induces Increased Firm Adhesion in an in Vitro Model of the Blood–Brain Barrier

    PubMed Central

    Strazza, Marianne; Pirrone, Vanessa; Wigdahl, Brian; Dampier, Will; Lin, Wei; Feng, Rui; Maubert, Monique E.; Weksler, Babette; Romero, Ignacio A.; Couraud, Pierre-Olivier; Nonnemacher, Michael R.

    2016-01-01

    The blood–brain barrier (BBB) has been defined as a critically important protective barrier that is involved in providing essential biologic, physiologic, and immunologic separation between the central nervous system (CNS) and the periphery. Insults to the BBB can cause overall barrier damage or deregulation of the careful homeostasis maintained between the periphery and the CNS. These insults can, therefore, yield numerous phenotypes including increased overall permeability, interendothelial gap formation, alterations in cytokine and chemokine secretion, and accelerated cellular passage. The current studies expose the human brain microvascular endothelial cell line, hCMEC/D3, to prolonged morphine exposure and aim to uncover the mechanisms underlying alterations in barrier function in vitro. These studies show alterations in the mRNA and protein levels of the cellular adhesion molecules (CAMs) intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and activated leukocyte cell adhesion molecule that correlate with an increased firm adhesion of the CD3+ subpopulation of peripheral blood mononuclear cells (PBMCs). Overall, these studies suggest that prolonged morphine exposure may result in increased cell migration into the CNS, which may accelerate pathological processes in many diseases that involve the BBB. PMID:27294916

  7. Prolonged Morphine Exposure Induces Increased Firm Adhesion in an in Vitro Model of the Blood-Brain Barrier.

    PubMed

    Strazza, Marianne; Pirrone, Vanessa; Wigdahl, Brian; Dampier, Will; Lin, Wei; Feng, Rui; Maubert, Monique E; Weksler, Babette; Romero, Ignacio A; Couraud, Pierre-Olivier; Nonnemacher, Michael R

    2016-01-01

    The blood-brain barrier (BBB) has been defined as a critically important protective barrier that is involved in providing essential biologic, physiologic, and immunologic separation between the central nervous system (CNS) and the periphery. Insults to the BBB can cause overall barrier damage or deregulation of the careful homeostasis maintained between the periphery and the CNS. These insults can, therefore, yield numerous phenotypes including increased overall permeability, interendothelial gap formation, alterations in cytokine and chemokine secretion, and accelerated cellular passage. The current studies expose the human brain microvascular endothelial cell line, hCMEC/D3, to prolonged morphine exposure and aim to uncover the mechanisms underlying alterations in barrier function in vitro. These studies show alterations in the mRNA and protein levels of the cellular adhesion molecules (CAMs) intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and activated leukocyte cell adhesion molecule that correlate with an increased firm adhesion of the CD3⁺ subpopulation of peripheral blood mononuclear cells (PBMCs). Overall, these studies suggest that prolonged morphine exposure may result in increased cell migration into the CNS, which may accelerate pathological processes in many diseases that involve the BBB. PMID:27294916

  8. PREEXPOSURE TO LOW OZONE CONCENTRATIONS DOES NOT DIMINISH THE PULMONARY FUNCTION RESPONSE ON EXPOSURE TO HIGHER OZONE CONCENTRATIONS

    EPA Science Inventory

    It has been well documented that persons exposed to the air pollutant ozone in concentrations between 0.40 and 0.50 ppm5 on consecutive days will adapt to the acute respiratory irritation of ozone. The adaptation consisted of the absence of any alteration in lung function during ...

  9. Nasal epithelial and inflammatory response to ozone exposure: a review of laboratory-based studies published since 1985.

    PubMed

    Nikasinovic, L; Momas, I; Seta, N

    2003-01-01

    This article summarizes biological events in human and animal nasal epithelium after short- and long-term exposure to ozone, the principal agent in photochemical smog. Despite anatomical and histological interspecies differences, ozone exposures resulted in common nasal qualitative alterations with an anterior-posterior gradient of phenomena occurring immediately, and with a lag time postexposure: epithelial disruption and increased permeability, inflammatory cell influx, and proliferative and secretory responses. Described mechanisms of toxicity included a direct effect of ozone on epithelial lining fluid and cellular membranes and the subsequent release of cytokines and cyclooxygenase and lipoxygenase products. An indirect effect of ozone was indicated by a decreased mucociliary clearance, free radicals production interacting with a gene promoting factor, and increased DNA synthesis. Studies highlighted the pivotal role of activated neutrophils and mast cells leading to the release of deleterious enzymes (tryptase, eosinophil cationic protein) and numerous cytokines. Experiments performed with ozone exposure/allergen challenge reported that, besides the intrinsic deleterious properties of ozone, it also had a priming effect on the late-phase response to allergen challenge, providing new insights into the pathophysiology of respiratory allergic diseases. PMID:12888446

  10. Evaluation of effects of ozone exposure on influenza infection in mice using several indicators of susceptibility.

    PubMed

    Selgrade, M K; Illing, J W; Starnes, D M; Stead, A G; Ménache, M G; Stevens, M A

    1988-07-01

    Mice were exposed to 1 ppm O3, 3 hr/day, for 5 consecutive days. Separate groups of mice were infected with influenza following each of the individual exposures. A twofold increase in the incidence of mortality and a 3-day decrease in mean survival time were observed in mice infected after the second exposure. There were no effects on percentage mortality or mean survival time due to exposure to 1 ppm O3 in mice infected after the first, third, fourth, or fifth exposure. When the exposure concentration was lowered to 0.5 ppm, there were no effects on mortality in mice infected after the second exposure. Five, daily, 3-hr exposures to 1 ppm O3 had no effect on virus titers in the lungs of mice infected after either the second or fifth exposure. In contrast, wet lung weights were significantly enhanced over infected air controls in mice infected after the second O3 exposure at both 1 and 0.5 ppm but not at 0.25 ppm exposure concentrations. This effect on lung wet weight was observed in mice infected with a dose of virus which produced 7-33% mortality in controls as well as in mice infected with a sublethal dose of virus. Histopathologic changes due to sublethal influenza infection, including nonsuppurative pneumonitis and necrosis, squamous metaplasia and hyperplasia of the epithelium lining the bronchi and bronchioles, were more severe in mice infected after the second of five, 1 ppm O3 exposure than in comparable air controls. Sublethal infection caused a loss of lung volume with secondary reduction in diffusing capability and homogenity of ventilation distribution. These latter two effects were also exacerbated in mice infected after the second of five, 1 ppm O3 exposures as compared to air controls. When mice were infected after the fifth, 1 ppm O3 exposure, there was no effect due to ozone on either lung wet weight or histopathology. The data indicate that O3 has little if any effect on antiviral defense mechanisms since virus titers in the lungs were not

  11. BVOC responses to realistic nitrogen fertilization and ozone exposure in silver birch.

    PubMed

    Carriero, G; Brunetti, C; Fares, S; Hayes, F; Hoshika, Y; Mills, G; Tattini, M; Paoletti, E

    2016-06-01

    Emission of BVOC (Biogenic Volatile Organic Compounds) from plant leaves in response to ozone exposure (O3) and nitrogen (N) fertilization is poorly understood. For the first time, BVOC emissions were explored in a forest tree species (silver birch, Betula pendula) exposed for two years to realistic levels of O3 (35, 48 and 69 ppb as daylight average) and N (10, 30 and 70 kg ha(-1) yr(-1), applied weekly to the soil as ammonium nitrate). The main BVOCs emitted were: α-pinene, β-pinene, limonene, ocimene, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) and hexanal. Ozone exposure increased BVOC emission and reduced total leaf area. The effect on emission was stronger when a short-term O3 metric (concentrations at the time of sampling) rather than a long-term one (AOT40) was used. The effect of O3 on total leaf area was not able to compensate for the stimulation of emission, so that responses to O3 at leaf and whole-plant level were similar. Nitrogen fertilization increased total leaf area, decreased α-pinene and β-pinene emission, and increased ocimene, hexanal and DMNT emission. The increase of leaf area changed the significance of the emission response to N fertilization for most compounds. Nitrogen fertilization mitigated the effects of O3 exposure on total leaf area, while the combined effects of O3 exposure and N fertilization on BVOC emission were additive and not synergistic. In conclusion, O3 exposure and N fertilization have the potential to affect global BVOC via direct effects on plant emission rates and changes in leaf area. PMID:26809503

  12. Diminished greenness of tomato leaves exposed to ozone and post-exposure recovery of greenness.

    PubMed

    Tenga, A Z; Ormrod, D P

    1990-01-01

    The response to ozone (O(3)) of greenness, in terms of estimated total chlorophyll concentration (Chl), of leaves at three plant canopy levels was studied in tomato (Lycopersicon esculentum Mill.) over a 10-day period following O(3) exposure. Plants of the cultivars 'New Yorker' and 'Tiny Tim' were grown at 25/15 degrees or 30/15 degrees day/night temperatures in growth chambers and exposed to 0.00, 0.08, 0.16 or 0.24 microl litre(-1) O(3) for 7 h day(-1) for four consecutive days in controlled environment exposure chambers. Measurement of Chl in the top, middle and bottom canopy leaves with a calibrated SPAD-501 leaf greenness meter indicated that the growth temperatures tested did not significantly influence the response of Chl to O(3). Ozone-induced loss of Chl was widespread in the entire foliage canopy, including foliage which did not demonstrate visible injury. In both cultvars the Chl in leaves at all three canopy levels declined as a function of increasing O(3) concentration when measured 2, 4, 6, 8 and 10 days after the exposure period. However, the slopes for leaves in the top and middle canopies decreased with increasing time after exposure. An analysis of this apparent Chl recovery indicated that leaves in the top and middle canopies exposed to 0.16 and 0.24 microl litre(-1) increased in greenness at a rapid rate after the marked initial decline associated with O(3) treatment. The apparent recovery of the top canopy may have reflected the growth of new leaves and their inclusion in the measurements, but this was not the case for the middle canopy for which the same leaves were measured throughout the post-exposure period. Bottom canopy leaves did not demonstrate significant recovery of Chl. PMID:15092305

  13. Pulmonary response to ozone exposures in healthy individuals aged 55 years or greater

    SciTech Connect

    Reisenauer, C.S.; Koenig, J.Q.; McManus, M.S.; Smith, M.S.; Kusic, G.; Pierson, W.E.

    1988-01-01

    Since minimal data are available regarding the pulmonary effects of ozone (O/sub 3/) in healthy individuals over the age of 55, this research was designed to determine if this group was at risk for pulmonary function changes when exposed to O/sub 3/ at ambient concentrations for one hour during intermittent exercise. Ten female and nine male subjects were exposed for 60 minutes in random order to one of the following O/sub 3/ concentrations: 0.0, 0.2, or 0.3 ppm. All exposures were administered through a rubber mouthpiece while the subject was either at rest or moderately exercising on a treadmill. The following pulmonary function tests (PFT) were recorded before exposure, and at periods immediately following and 20 minutes post-exposure: total respiratory resistance (R/sub T/), thoracic gas volume at functional residual capacity (FRC), and forced expiratory volume in one second (FEV/sub 1/). Baseline PFT mean values and air exposure PFT mean values were compared through the use of repeated measure two-way analysis of variance to detect any significant effect of exposure on these parameters. Following 60 minute of exposure at light intermittent exercise, there were no statistically significant pulmonary functional changes observed in male subjects. However, in female subjects, a statistically significant increase in R/sub T/ was observed

  14. Respiratory responses of vigorously exercising children to 0. 12 ppm ozone exposure

    SciTech Connect

    McDonnell, W.F. 3d.; Chapman, R.S.; Leigh, M.W.; Strope, G.L.; Collier, A.M.

    1985-10-01

    Changes in respiratory function have been suggested for children exposed to less than 0.12 ppm ozone (O3) while engaged in normal activities. Because the results of these studies have been confounded by other variables, such as temperature or the presence of other pollutants or have been questioned as to the adequacy of exposure measurements, the authors determined the acute response of children exposed to 0.12 ppm O3 in a controlled chamber environment. Twenty-three white males 8 to 11 yr of age were exposed once to clean air and once to 0.12 ppm O3 in random order. Exposures were for 2.5 h and included 2 h of intermittent heavy exercise. Measures of forced expiratory volume in one second (FEV1) and the symptom cough were determined prior to and after each exposure. A significant decline in FEV1 was found after the O3 exposure compared to the air exposure, and it appeared to persist for 16 to 20 h. No significant increase in cough was found due to O3 exposure. Forced vital capacity, specific airways resistance, respiratory frequency, tidal volume, and other symptoms were measured in a secondary exploratory analysis of this study.

  15. EVALUATION OF OZONE EXPOSURE INDICES IN EXPOSURE-RESPONSE MODELING (JOURNAL VERSION)

    EPA Science Inventory

    In exposure-response modeling, a major concern is the numerical definition of exposure in relating crop loss to O3, yet few indices have been considered. The paper addresses research in which plant growth was regressed for soybean, wheat, cotton, corn, and sorghum against 613 num...

  16. Physiological responses of mules on prolonged exposure to high altitude (3 650 m)

    NASA Astrophysics Data System (ADS)

    Riar, S. S.; Shankar Bhat, K.; Sen Gupta, J.

    1982-06-01

    Eight healthy male animals were inducted and kept for 2 1/2 years at 3 650 m altitude and subjected to normal work schedules. Physiological measurements viz. heart rate, blood pressure, minute ventilation, oxygen consumption, respiration rate, hemoglobin, packed cell haematocrit volume and eosinophil count were made on these animals at periodic intervals. On acute induction to an altitude of 3 650 m these animals demonstrated a sudden increase in tidal volume, a decrease in Rf and no change in VE, suggesting a decreased dead space/tidal volume ratio at altitude. However, all these changes stabilised within 3 weeks but on prolongation of stay, the physical state of these animals was adversely affected. The respiratory adjustments occurring on return to sea level appear to be a response to thermal stress. The initial increase in heart rate and blood pressure stabilised by the 2nd week.

  17. Exposure of pink salmon embryos to dissolved polynuclear aromatic hydrocarbons delays development, prolonging vulnerability to mechanical damage.

    PubMed

    Carls, Mark G; Thedinga, John F

    2010-06-01

    Exposure to dissolved polynuclear aromatic hydrocarbons (PAHs) from crude oil delays pink salmon (Oncorhynchus gorbuscha) embryo development, thus prolonging their susceptibility to mechanical damage (shock). Exposure also caused mortality, edema, and anemia consistent with previous studies. Hatching and yolk consumption were delayed, indicating the rate of embryonic development was slowed by PAH exposure. The net result was that exposed embryos were more susceptible to shock than normal, unexposed embryos. Susceptibility to shock was protracted by 4-6d for more than a month in embryos exposed to exponentially declining, dissolved PAH concentrations in water passed through oiled rock; the initial total PAH concentration was 22.4microgL(-1) and the geometric mean concentration was 4.5microgL(-1) over the first 20d. Protracted susceptibility to shock caused by exposure to PAHs dissolved from oil could potentially increase the reported incidence of mortality in oiled stream systems, such as those in Prince William Sound after the Exxon Valdez oil spill, if observers fail to discriminate between direct mortality and shock-induced mortality. PMID:20089299

  18. Prolonged Oxaliplatin Exposure Alters Intracellular Calcium Signaling: A New Mechanism To Explain Oxaliplatin-Associated Peripheral Neuropathy

    PubMed Central

    Schulze, Christin; McGowan, Margit; Jordt, Sven; Ehrlich, Barbara E

    2012-01-01

    Oxaliplatin is a platinum based cytotoxic agent commonly used to treat colorectal cancers. Despite its effectiveness, oxaliplatin administration is associated with the development of cold-induced peripheral neuropathy. This potentially permanent side effect is provoked by cold exposure and can range from mild and self limited to severe and debilitating. Even with tumor shrinkage, these painful side effects can force dose-reduction or discontinuation of treatment. Neither the mechanism of action of oxaliplatin nor that of cold-induced neuropathy is understood. Paclitaxel, an entirely different chemotherapeutic agent used to treat a variety of malignancies, also is associated with the development of peripheral neuropathy. Unlike oxaliplatin, neurotoxicity arising from paclitaxel treatment is better understood and was found to have profound effects on intracellular calcium signaling (1,2). In this study we examined the effects of oxaliplatin on calcium signaling pathways and found that acute exposure of either a neuroblastoma cell line or primary neurons with therapeutic concentrations of oxaliplatin had no effect on intracellular calcium signaling. We also found that cellular temperature sensors (TRP channels) were also not activated by oxaliplatin. Interestingly, prolonged exposure of oxaliplatin sensitized cells to subsequent stimuli and enhanced the magnitude of intracellular calcium responses. Taken together, our results suggest that acute oxaliplatin exposure will not induce abnormal calcium signaling but oxaliplatin-primed cells do exhibit enhanced sensitivity. These findings provide new insight to the mechanism behind oxaliplatin-induced neuropathy. PMID:21859566

  19. Responses of two birch ( Betula pendula Roth) clones to different ozone profiles with similar AOT40 exposure

    NASA Astrophysics Data System (ADS)

    Oksanen, Elina; Holopainen, Toini

    Saplings of two clones of European white birch ( Betula pendula Roth) were exposed to three different ozone profiles resulting in same AOT40 value of 13-14 ppm h in a chamber experiment. The sensitive clone 5 and the more tolerant clone 2 were growing (1) under filtered air (=control), or (2) were exposed to 70 ppb ozone for 24 h d -1 (=profile 1), (3) to 100 ppb ozone for 12 h d -1 at 8:00-20:00 (=profile 2), or (4) to 200 ppb ozone for 4.5 h d -1 at 9:30-14:00 (=profile 3) for 20 d. The saplings were determined for growth, visible leaf injuries, stomatal conductance, and concentrations of Rubisco, chlorophyll and carotenoids. Growth responses and induction of visible foliar injuries under different ozone profiles were variable, resulting in 4-17% lower dry mass of shoot, 16-46% reduction in stem height increment and 11-43% increase in visible injuries in clone 5, which was accompanied by higher leaf turnover rate under profile 3 indicating compensation growth. In clone 2, ozone-induced responses ranged from slight stimulation in stem height growth to 13% decrease in dry mass of shoot and 2-16% increase in visible injuries. Daytime stomatal conductance rates were lowered by 14-54% in clone 5 and 9-74% in clone 2, depending on profile. The additional power-weighted analyses revealed that high peak concentrations and exposure shape were important for induction of visible injuries in both clones and reduction in stomatal conductance in clone 5, whereas growth reductions were rather related to total cumulative exposure. The results indicate that profile of ozone exposure, night-time stomatal conductance (24 h flux), and recovery time for defence and compensations reactions should not be ignored in plant response and ozone flux modelling.

  20. Evaluation of the CNS and cardiovascular effects of prolonged exposure to bromotrifluromethane (CBrF3)

    NASA Technical Reports Server (NTRS)

    Geller, I.; Garcia, C.; Gleiser, C.; Haines, R., Jr.; Hamilton, M.; Hartmann, R., Jr.; Mendez, V.; Samuels, A.; Miguel, M. S.

    1981-01-01

    The proposed use of bromotrifluoromethane (CBrF3) as a fire extinguishant in aircraft, spacecraft and submarines has stimulated increasing interest and research in the toxicological properties of this compound. In a spacecraft, because of its unique recirculating life support system, the introduction of CBrF3 by leakage or intentional discharge, will result in continuous exposure of crewman to low concentrations of this compound for periods of up to 7 days, or possibly even longer. The effects of low concentrations of CBrF3, under continuous exposure conditions, on the CNS and cardiovascular systems of animals to enable an assessment of these risks were investigated.

  1. Severe, multimodal stress exposure induces PTSD-like characteristics in a mouse model of single prolonged stress.

    PubMed

    Perrine, Shane A; Eagle, Andrew L; George, Sophie A; Mulo, Kostika; Kohler, Robert J; Gerard, Justin; Harutyunyan, Arman; Hool, Steven M; Susick, Laura L; Schneider, Brandy L; Ghoddoussi, Farhad; Galloway, Matthew P; Liberzon, Israel; Conti, Alana C

    2016-04-15

    Appropriate animal models of posttraumatic stress disorder (PTSD) are needed because human studies remain limited in their ability to probe the underlying neurobiology of PTSD. Although the single prolonged stress (SPS) model is an established rat model of PTSD, the development of a similarly-validated mouse model emphasizes the benefits and cross-species utility of rodent PTSD models and offers unique methodological advantages to that of the rat. Therefore, the aims of this study were to develop and describe a SPS model for mice and to provide data that support current mechanisms relevant to PTSD. The mouse single prolonged stress (mSPS) paradigm, involves exposing C57Bl/6 mice to a series of severe, multimodal stressors, including 2h restraint, 10 min group forced swim, exposure to soiled rat bedding scent, and exposure to ether until unconsciousness. Following a 7-day undisturbed period, mice were tested for cue-induced fear behavior, effects of paroxetine on cue-induced fear behavior, extinction retention of a previously extinguished fear memory, dexamethasone suppression of corticosterone (CORT) response, dorsal hippocampal glucocorticoid receptor protein and mRNA expression, and prefrontal cortex glutamate levels. Exposure to mSPS enhanced cue-induced fear, which was attenuated by oral paroxetine treatment. mSPS also disrupted extinction retention, enhanced suppression of stress-induced CORT response, increased mRNA expression of dorsal hippocampal glucocorticoid receptors and decreased prefrontal cortex glutamate levels. These data suggest that the mSPS model is a translationally-relevant model for future PTSD research with strong face, construct, and predictive validity. In summary, mSPS models characteristics relevant to PTSD and this severe, multimodal stress modifies fear learning in mice that coincides with changes in the hypothalamo-pituitary-adrenal (HPA) axis, brain glucocorticoid systems, and glutamatergic signaling in the prefrontal cortex. PMID

  2. A comparison of acid aerosol and ozone exposure patterns in a summertime study of metropolitan Philadelphia

    SciTech Connect

    Waldman, J.M.; Liang, C.S.K.; Koutrakis, P.; Suh, H.; Allen, G.; Burton, R.; Wilson, W.E.

    1994-12-31

    A study of acid aerosol and ozone exposure patterns was conducted for metropolitan Philadelphia between June and August 1992. Included in the study design were daily monitoring of particulate strong acidity (PSA), sulfate (SO{sub 4}{sup {minus}2}) and hourly ozone data (O{sub 3}) at a citywide network. A continuous sulfate thermal speciation analyzer at one site collected hourly concentration data for SO{sub 4}{sup {minus}2} aerosol. The current paper presents temporal patterns of continuous measurements for O{sub 3} and SO{sub 4}{sup {minus}2} aerosol. Both pollutants had similar daily peak periods in the mid-afternoon, although the range for O{sub 3} was much greater than for SO{sub 4}{sup {minus}2} aerosol. The daily peak values were also correlated for the two species during the study period. It seems that many of the same meteorological factors affect the spatial and temporal patterns for these lung irritants. Hence, the similarity in exposure patterns for O{sub 3} and SO{sub 4}{sup {minus}2} aerosol is reason for concern, regarding possible synergism from coincident doses.

  3. Comparative cellular toxicity of titanium dioxide nanoparticles on human astrocyte and neuronal cells after acute and prolonged exposure.

    PubMed

    Coccini, Teresa; Grandi, Stefania; Lonati, Davide; Locatelli, Carlo; De Simone, Uliana

    2015-05-01

    Although in the last few decades, titanium dioxide nanoparticles (TiO₂NPs) have attracted extensive interest due to their use in wide range of applications, their influences on human health are still quite uncertain and less known. Evidence exists indicating TiO₂NPs ability to enter the brain, thus representing a realistic risk factor for both chronic and accidental exposure with the consequent needs for more detailed investigation on CNS. A rapid and effective in vitro test strategy has been applied to determine the effects of TiO₂NPs anatase isoform, on human glial (D384) and neuronal (SH-SY5Y) cell lines. Toxicity was assessed at different levels: mitochondrial function (by MTT), membrane integrity and cell morphology (by calcein AM/PI staining) after acute exposure (4-24-48 h) at doses from 1.5 to 250 μg/ml as well as growth and cell proliferation (by clonogenic test) after prolonged exposure (7-10 days) at sub-toxic concentrations (from 0.05 to 31 μg/ml). The cytotoxic effects of TiO₂NPs were compared with those caused by TiO₂ bulk counterpart treatment. Acute TiO₂NP exposure produced (i) dose- and time-dependent alterations of the mitochondrial function on D384 and SH-SY5Y cells starting at 31 and 15 μg/ml doses, respectively, after 24h exposure. SH-SY5Y were slightly more sensitive than D384 cells; and (ii) cell membrane damage occurring at 125 μg/ml after 24h exposure in both cerebral cells. Comparatively, the effects of TiO₂ bulk were less pronounced than those induced by nanoparticles in both cerebral cell lines. Prolonged exposure indicated that the proliferative capacity (colony size) was compromised at the extremely low TiO₂NP doses namely 1.5 μg/ml and 0.1 μg/ml for D384 and SH-SY5Y, respectively; cell sensitivity was still higher for SH-SY5Y compared to D384. Colony number decrease (15%) was also evidenced at ≥0.2 μg/ml TiO₂NP dose. Whereas, TiO₂ bulk treatment affected cell morphology only. TiO₂ internalization in SH

  4. Prolonged head-down tilt exposure reduces maximal cutaneous vasodilator and sweating capacity in humans

    NASA Technical Reports Server (NTRS)

    Crandall, C. G.; Shibasaki, M.; Wilson, T. E.; Cui, J.; Levine, B. D.

    2003-01-01

    Cutaneous vasodilation and sweat rate are reduced during a thermal challenge after simulated and actual microgravity exposure. The effects of microgravity exposure on cutaneous vasodilator capacity and on sweat gland function are unknown. The purpose of this study was to test the hypothesis that simulated microgravity exposure, using the 6 degrees head-down tilt (HDT) bed rest model, reduces maximal forearm cutaneous vascular conductance (FVC) and sweat gland function and that exercise during HDT preserves these responses. To test these hypotheses, 20 subjects were exposed to 14 days of strict HDT bed rest. Twelve of those subjects exercised (supine cycle ergometry) at 75% of pre-bed rest heart rate maximum for 90 min/day throughout HDT bed rest. Before and after HDT bed rest, maximal FVC was measured, via plethysmography, by heating the entire forearm to 42 degrees C for 45 min. Sweat gland function was assessed by administering 1 x 10(-6) to 2 M acetylcholine (9 doses) via intradermal microdialysis while simultaneously monitoring sweat rate over the microdialysis membranes. In the nonexercise group, maximal FVC and maximal stimulated sweat rate were significantly reduced after HDT bed rest. In contrast, these responses were unchanged in the exercise group. These data suggest that 14 days of simulated microgravity exposure, using the HDT bed rest model, reduces cutaneous vasodilator and sweating capacity, whereas aerobic exercise training during HDT bed rest preserves these responses.

  5. Premature mortality in India due to PM2.5 and ozone exposure

    NASA Astrophysics Data System (ADS)

    Ghude, Sachin D.; Chate, D. M.; Jena, C.; Beig, G.; Kumar, R.; Barth, M. C.; Pfister, G. G.; Fadnavis, S.; Pithani, Prakash

    2016-05-01

    This bottom-up modeling study, supported by new population census 2011 data, simulates ozone (O3) and fine particulate matter (PM2.5) exposure on local to regional scales. It quantifies, present-day premature mortalities associated with the exposure to near-surface PM2.5 and O3 concentrations in India using a regional chemistry model. We estimate that PM2.5 exposure leads to about 570,000 (CI95: 320,000-730,000) premature mortalities in 2011. On a national scale, our estimate of mortality by chronic obstructive pulmonary disease (COPD) due to O3 exposure is about 12,000 people. The Indo-Gangetic region accounts for a large part (~42%) of the estimated mortalities. The associated lost life expectancy is calculated as 3.4 ± 1.1 years for all of India with highest values found for Delhi (6.3 ± 2.2 years). The economic cost of estimated premature mortalities associated with PM2.5 and O3 exposure is about 640 (350-800) billion USD in 2011, which is a factor of 10 higher than total expenditure on health by public and private expenditure.

  6. The effects of ozone exposure and associated injury mechanisms on the central nervous system.

    PubMed

    Martínez-Lazcano, Juan Carlos; González-Guevara, Edith; del Carmen Rubio, María; Franco-Pérez, Javier; Custodio, Verónica; Hernández-Cerón, Miguel; Livera, Carlos; Paz, Carlos

    2013-01-01

    Ozone (O3) is a component of photochemical smog, which is a major air pollutant and demonstrates properties that are harmful to health because of the toxic properties that are inherent to its powerful oxidizing capabilities. Environmental O3 exposure is associated with many symptoms related to respiratory disorders, which include loss of lung function, exacerbation of asthma, airway damage, and lung inflammation. The effects of O3 are not restricted to the respiratory system or function - adverse effects within the central nervous system (CNS) such as decreased cognitive response, decrease in motor activity, headaches, disturbances in the sleep-wake cycle, neuronal dysfunctions, cell degeneration, and neurochemical alterations have also been described; furthermore, it has also been proposed that O3 could have epigenetic effects. O3 exposure induces the reactive chemical species in the lungs, but the short half-life of these chemical species has led some authors to attribute the injurious mechanisms observed within the lungs to inflammatory processes. However, the damage to the CNS induced by O3 exposure is not well understood. In this review, the basic mechanisms of inflammation and activation of the immune system by O3 exposure are described and the potential mechanisms of damage, which include neuroinflammation and oxidative stress, and the signs and symptoms of disturbances within the CNS caused by environmental O3 exposure are discussed. PMID:23585211

  7. Effect of acute exposure to ozone on heart rate and blood pressure of the conscious rat

    SciTech Connect

    Uchiyama, I.; Simomura, Y.; Yokoyama, E.

    1985-12-01

    Electrocardiogram and arterial blood pressure in conscious and unrestrained rats of various ages were recorded during a 3-hr exposure to filtered air or 1 ppm ozone (O/sub 3/). In general, heart rate and mean arterial blood pressure of rats significantly decreased during exposure to O/sub 3/, whereas these functional parameters remained almost stable during exposure to filtered air. Heart rate usually reached a plateau during the exposure to O/sub 3/. Additionally, PR interval and QRS complex significantly increased and premature atrial contraction and incomplete A-V block were frequently observed during the exposure to O/sub 3/. These circulatory effects of O/sub 3/ were more markedly manifested by rats 11 weeks old than either those 8 or 4 weeks old. On the other hand, no significant difference in the circulatory responses was observed between male and female rats. These circulatory effects of O/sub 3/ may be significant from the viewpoint of health effects, although its mechanisms remain unsolved.

  8. Effects of prolonged exposure to 4-tert-octylphenol on toxicity and indices of oestrogenic exposure in the sand goby (Pomatoschistus minutus, Pallas).

    PubMed

    Robinson, Craig D; Brown, Elaine; Craft, John A; Davies, Ian M; Moffat, Colin F

    2004-07-01

    Alkylphenolic compounds are present in estuarine and marine environments. They are moderately bioaccumulative, and oestrogenic to fish following three week, in vivo, exposures. The effects of prolonged exposure are, as yet, unclear. Sand goby (Pomatoschistus minutus) were exposed to measured concentrations of 4-tert-octylphenol (OP) in a 28-day, dose-ranging study, and a six month temporal response study. Following 28-days exposure to measured 31+/-6 or 101+/-47 microg l(-1) OP (mean+/-SD), immature male sand goby showed elevated vitellogenin (VTG) mRNA expression. Plasma alkali-labile phosphate concentrations were elevated in both sexes and were higher in females than males. Although measured OP concentrations were variable, they were significantly different for each treatment and a range of concentration-dependent effects were observed. The LC(50) for chronic OP exposure (8 weeks) was 29+/-6 microg l(-1), and both sexes demonstrated concentration and duration dependent increases in VTG mRNA expression. Exposure to 28+/-20 microg l(-1) OP (median+/-95% CI) for 6 months inhibited development of male nuptial colouration and sperm duct glands. These findings are discussed in relation to environmental concentrations of alkylphenols and ecological concerns. PMID:15046944

  9. Prolonged ampakine exposure prunes dendritic spines and increases presynaptic release probability for enhanced long-term potentiation in the hippocampus.

    PubMed

    Chang, Philip K-Y; Prenosil, George A; Verbich, David; Gill, Raminder; McKinney, R Anne

    2014-09-01

    CX 546, an allosteric positive modulator of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type ionotropic glutamate receptors (AMPARs), belongs to a drug class called ampakines. These compounds have been shown to enhance long-term potentiation (LTP), a cellular model of learning and memory, and improve animal learning task performance, and have augmented cognition in neurodegenerative patients. However, the chronic effect of CX546 on synaptic structures has not been examined. The structure and integrity of dendritic spines are thought to play a role in learning and memory, and their abnormalities have been implicated in cognitive disorders. In addition, their structural plasticity has been shown to be important for cognitive function, such that dendritic spine remodeling has been proposed as the morphological correlate for LTP. Here, we tested the effect of CX546 on dendritic spine remodeling following long-term treatment. We found that, with prolonged CX546 treatment, organotypic hippocampal slice cultures showed a significant reduction in CA3-CA1 excitatory synapse and spine density. Electrophysiological approaches revealed that the CA3-CA1 circuitry compensates for this synapse loss by increasing synaptic efficacy through enhancement of presynaptic release probability. CX546-treated slices showed prolonged and enhanced potentiation upon LTP induction. Furthermore, structural plasticity, namely spine head enlargement, was also more pronounced after CX546 treatment. Our results suggest a concordance of functional and structural changes that is enhanced with prolonged CX546 exposure. Thus, the improved cognitive ability of patients receiving ampakine treatment may result from the priming of synapses through increases in the structural plasticity and functional reliability of hippocampal synapses. PMID:24925283

  10. Music exposure induced prolongation of cardiac allograft survival and generated regulatory CD4⁺ cells in mice.

    PubMed

    Uchiyama, M; Jin, X; Zhang, Q; Amano, A; Watanabe, T; Niimi, M

    2012-05-01

    In clinical practice, music has been used to decrease stress, heart rate, and blood pressure and to provide a distraction from disease symptoms. We investigated sound effects on alloimmune responses in murine heart transplantation. Naïve and eardrum-ruptured CBA/N (CBA, H2(K)) underwent transplantation of a C57BL/6 (B6, H2(b)) heart and were exposed to 1 of 3 types of music-opera (La Traviata), classical (Mozart), and New Age (Enya)-or 1 of 6 different single sound frequencies for 7 days. An adoptive transfer study was performed to determine whether regulatory cells were generated in allograft recipients. Cell-proliferation, cytokine, and flow cytometry assessments were also performed. CBA recipients of a B6 graft exposed to opera and classical music had significantly prolonged allograft survival (median survival times [MSTs], 26.5 and 20 days, respectively), whereas those exposed to 6 single sound frequencies and New Age did not (MSTs, 7, 8, 9, 8, 8, 8, and 11 days, respectively). Untreated and eardrum-ruptured CBA rejected B6 grafts acutely (MSTs, 7 and 8.5 days, respectively). Adoptive transfer of whole splenocytes, CD4(+) cells, and CD4(+)CD25(+) cells from opera-exposed primary recipients resulted in significantly prolonged allograft survival in naive secondary recipients (MSTs, 36, 68, and >50 days, respectively). Cell-proliferation, interleukin (IL)-2 and interferon-γ were suppressed in opera-exposed mice, whereas IL-4 and IL-10 from opera-exposed recipients were up-regulated. Flow cytometry studies showed an increased CD4(+)CD25(+)Foxp3(+) cell population in splenocytes from opera-exposed mice. In conclusion, exposure to some types of music may induce prolonged survival of fully allogeneic cardiac allografts and generate CD4(+)CD25(+)Foxp3(+) regulatory cells. PMID:22564629

  11. A special type of scald caused by prolonged exposure to slowly heated water.

    PubMed

    Pircher, R; Pollak, S; Vogt, S; Epting, T; Kramer, L; Geisenberger, D

    2016-06-01

    When skin is subjected to water temperatures gradually rising from moderate to critical ranges for a prolonged period of time, the resulting scalds will initially present as reddening, followed by blistering and at last by full-thickness burns. On changing from second- to third-degree burn, the blisters stop to become enlarged and solidify due to heat-induced coagulation necrosis. Such gradually intensifying tissue damage results in multiple firm skin blisters together with third-degree burn of the affected area. The initially serous blister fluid assumes a jelly-like consistency as the proteins undergo denaturation. Scalds of this special type may occur in persons taking a bath and becoming incapable to act so that the warm water tap remains turned on or a hairdryer continues to work after having been dropped into the bath water. On the basis of two relevant fatalities (suicidal electrocutions in bathtubs by means of hairdryers), the macroscopic and histological appearance of blisters which only secondarily turned into a full-thickness scald is compared with blisters in genuine second-degree scalds. The blister fluid of the latter ones was also investigated as to their protein composition and hemoglobin concentration. PMID:27129143

  12. Can prolonged exposure to low VPD disturb the ABA signalling in stomatal guard cells?

    PubMed Central

    Aliniaeifard, Sasan; van Meeteren, Uulke

    2013-01-01

    The response of stomata to many environmental factors is well documented. Multiple signalling pathways for abscisic acid (ABA)-induced stomatal closure have been proposed over the last decades. However, it seems that exposure of a leaf for a long time (several days) to some environmental conditions generates a sort of memory in the guard cells that results in the loss of suitable responses of the stomata to closing stimuli, such as desiccation and ABA. In this review paper we discuss changes in the normal pattern of signal transduction that could account for disruption of guard cell signalling after long-term exposure to some environmental conditions, with special emphasis on long-term low vapour pressure deficit (VPD). PMID:23956410

  13. Survival of the anaerobic fungus Orpinomyces sp. strain C1A after prolonged air exposure

    PubMed Central

    Struchtemeyer, Christopher G.; Ranganathan, Abhaya; Couger, M. B.; Liggenstoffer, Audra S.; Youssef, Noha H.; Elshahed, Mostafa S.

    2014-01-01

    Anaerobic fungi are efficient plant biomass degraders and represent promising agents for a variety of biotechnological applications. We evaluated the tolerance of an anaerobic fungal isolate, Orpinomyces sp. strain C1A, to air exposure in liquid media using soluble (cellobiose) and insoluble (dried switchgrass) substrates. Strain C1A grown on cellobiose survived for 11, and 13.5 hours following air exposure when grown under planktonic, and immobilized conditions, respectively. When grown on switchgrass media, strain C1A exhibited significantly enhanced air tolerance and survived for 168 hours. The genome of strain C1A lacked a catalase gene, but contained superoxide dismutase and glutathione peroxidase genes. Real time PCR analysis indicated that superoxide dismutase, but not glutathione peroxidase, exhibits a transient increase in expression level post aeration. Interestingly, the C1A superoxide dismutase gene of strain C1A appears to be most closely related to bacterial SODs, which implies its acquisition from a bacterial donor via cross kingdom horizontal gene transfer during Neocallimastigomycota evolution. We conclude that strain C1A utilizes multiple mechanisms to minimize the deleterious effects of air exposure such as physical protection and the production of oxidative stress enzymes. PMID:25367149

  14. Survival of the anaerobic fungus Orpinomyces sp. strain C1A after prolonged air exposure.

    PubMed

    Struchtemeyer, Christopher G; Ranganathan, Abhaya; Couger, M B; Liggenstoffer, Audra S; Youssef, Noha H; Elshahed, Mostafa S

    2014-01-01

    Anaerobic fungi are efficient plant biomass degraders and represent promising agents for a variety of biotechnological applications. We evaluated the tolerance of an anaerobic fungal isolate, Orpinomyces sp. strain C1A, to air exposure in liquid media using soluble (cellobiose) and insoluble (dried switchgrass) substrates. Strain C1A grown on cellobiose survived for 11, and 13.5 hours following air exposure when grown under planktonic, and immobilized conditions, respectively. When grown on switchgrass media, strain C1A exhibited significantly enhanced air tolerance and survived for 168 hours. The genome of strain C1A lacked a catalase gene, but contained superoxide dismutase and glutathione peroxidase genes. Real time PCR analysis indicated that superoxide dismutase, but not glutathione peroxidase, exhibits a transient increase in expression level post aeration. Interestingly, the C1A superoxide dismutase gene of strain C1A appears to be most closely related to bacterial SODs, which implies its acquisition from a bacterial donor via cross kingdom horizontal gene transfer during Neocallimastigomycota evolution. We conclude that strain C1A utilizes multiple mechanisms to minimize the deleterious effects of air exposure such as physical protection and the production of oxidative stress enzymes. PMID:25367149

  15. ASSESSMENT OF INDIVIDUAL HUMAN EXPOSURES TO OZONE IN A HEALTH STUDY

    EPA Science Inventory

    The minute dose of ozone delivered to the lower respiratory tract of a subject depends upon the ozone concentration inhaled, the minute volume (Ve 1/min) and the fraction of the inhaled ozone that penetrates the nasopharyngeal passages to enter the trachea. The ozone concentratio...

  16. Cognitive and Affective Predictors of Treatment Outcome in Cognitive Processing Therapy and Prolonged Exposure for Posttraumatic Stress Disorder

    PubMed Central

    Rizvi, Shireen L.; Vogt, Dawne S.; Resick, Patricia A.

    2009-01-01

    This study examined cognitive and affective predictors of treatment dropout and treatment efficacy in Cognitive Processing Therapy (CPT) and Prolonged Exposure (PE) for PTSD. Study participants were women with PTSD from a sexual assault who received at least one session of either treatment (n=145) as part of a randomized clinical trial. Results revealed that younger age, lower intelligence, and less education were associated with higher treatment dropout, whereas higher depression and guilt at pretreatment were associated with greater improvement in PTSD symptomatology. Results by treatment condition indicated that women with higher anger at pretreatment were more likely to drop out of PE and that older women in PE and younger women in CPT had the best overall outcomes. These findings have implications for efforts to enhance treatment efficacy and retention in CBT treatment protocols. PMID:19595295

  17. Cognitive and affective predictors of treatment outcome in Cognitive Processing Therapy and Prolonged Exposure for posttraumatic stress disorder.

    PubMed

    Rizvi, Shireen L; Vogt, Dawne S; Resick, Patricia A

    2009-09-01

    This study examined cognitive and affective predictors of treatment dropout and treatment efficacy in Cognitive Processing Therapy (CPT) and Prolonged Exposure (PE) for PTSD. Study participants were women with PTSD from a sexual assault who received at least one session of either treatment (n = 145) as part of a randomized clinical trial. Results revealed that younger age, lower intelligence, and less education were associated with higher treatment dropout, whereas higher depression and guilt at pretreatment were associated with greater improvement in PTSD symptomatology. Results by treatment condition indicated that women with higher anger at pretreatment were more likely to dropout of PE and that older women in PE and younger women in CPT had the best overall outcomes. These findings have implications for efforts to enhance treatment efficacy and retention in CBT treatment protocols. PMID:19595295

  18. Prior exposure to ozone potentiates subsequent response to sulfur dioxide in adolescent asthmatic subjects

    SciTech Connect

    Koenig, J.Q.; Covert, D.S.; Hanley, Q.S.; van Belle, G.; Pierson, W.E. )

    1990-02-01

    The objective of this study was to test whether prior exposure to a low concentration of ozone (120 ppb) would condition airways in asthmatic subjects to respond to a subthreshold concentration of sulfur dioxide (100 ppb). Eight male and five female subjects 12 to 18 yr of age participated. They all had allergic asthma and exercise-induced bronchospasm. Subjects were exposed to three test atmosphere sequences during intermittent moderate exercise (a 45-min exposure to one pollutant followed by a 15-min exposure to the second pollutant). The sequences were: air followed by 100 ppb SO2, 120 ppb O3 followed by 120 ppb O3, and 120 ppb O3 followed by 100 ppb SO2. The pulmonary function measurements assessed were FEV1, total respiratory resistance (RT), and maximal flow (Vmax50). Air-SO2 and O3-O3 exposures did not cause significant changes in pulmonary function. On the other hand, exposure to 100 ppb SO2 after a 45-min exposure to 120 ppb O3 caused a significant (8%) decrease in FEV1 (p = 0.046), a significant (19%) increase in RT (p = 0.048), and a significant (15%) decrease in Vmax50 (p = 0.008). It is concluded that prior O3 exposure increased bronchial hyperresponsiveness in these subjects such that they responded to an ordinarily subthreshold concentration of SO2. These data suggest that assessment of pulmonary changes to single pollutant challenges overlooks the interactive effects of common coexisting or sequentially occurring air pollutants.

  19. Pulmonary sensitivity to ozone exposure in sedentary versus chronically trained, female rats.

    PubMed

    Gordon, Christopher J; Phillips, Pamela M; Beasley, Tracey E; Ledbetter, A; Aydin, Cenk; Snow, Samantha J; Kodavanti, Urmila P; Johnstone, Andrew F

    2016-06-01

    Epidemiological data suggest that a sedentary lifestyle may contribute to increased susceptibility for some environmental toxicants. We developed an animal model of active versus sedentary life style by providing female Sprague-Dawley rats with continuous access to running wheels. Sedentary rats were housed in standard cages without wheels. After training for 12 wks, rats were exposed to 0, 0.25, 0.5 or 1.0 ppm ozone [O3 for 5 h/d, 1 d/wk, for 6 wk (N = 10 per group)]. Body composition (%fat, lean and fluid) was monitored noninvasively over the course of the study. Ventilatory parameters [tidal volume, minute ventilation, frequency and enhanced pause (Penh)] were assessed using whole-body plethysmography prior to O3 and 24 h after the 5th O3 exposure. Trained rats lost ∼2% body fat after 12 wk of access to running wheels. Peak wheel activity was reduced by 40% after exposure to 1.0 ppm O3. After the 5th O3 exposure, body weight and %fat were reduced in sedentary but not trained rats. Penh was significantly elevated in sedentary but not trained rats the day after exposure to 1.0 ppm O3. However, lung lavage cell counts and biomarkers of pulmonary inflammation measured 1 day after the final exposure were inconsistently affected by training. Wheel running led to marked physiological responses along with some indication of improved pulmonary recovery from O3 exposure. However, wheel running with O3 exposure may also be a detriment for some pulmonary endpoints. Overall, a sedentary lifestyle may increase susceptibility to O3, but additional studies are needed. PMID:27160658

  20. Mucous cell metaplasia in rat nasal epithelium after a 20-month exposure to ozone: A morphometric study of epithelial differentiation

    SciTech Connect

    Harkema, J.R.; Hotchkiss, J.A.; Griffith, W.C. |

    1997-12-31

    The present study was designed to examine the effects of long-term ozone exposure on nasal epithelia and intraepithelial mucosubstances (IM) throughout the nasal airways of F344/N rats. Animals were exposed to 0 (controls). 0. 12. 0.5, or 1.0 ppm ozone. 6 h/day, 5 days/wk. for 20 mo. Rats were killed 1 wk after the end of the exposure. and nasal tissues were processed for light and electron microscopy. Standard morphometric techniques were used to determine epithelial cell densities and the amounts of IM in the surface epithelium lining the nasal airways. No mucous cells or IM were present in the epithelia lining the nasal lateral meatus and maxillary sinus of rats exposed to 0 or 0.12 ppm ozone. In contrast, rats exposed to 0.5 or 1.0 ppm ozone had marked mucous cell metaplasia (MCM) with numerous mucous cells and conspicuous amounts of IM in the surface epithelium lining these upper airways. Ozone-induced increases in total epithelial cells (i.e., epithelial hyperplasia) were present only in rats exposed to 1.0 ppm. The results of this study indicate that rats chronically exposed to 1.0 or 0.5 ppm, but not 0. 121 ppm. ozone can develop marked MCM with significant increases in IM in both proximal and distal nasal airways. The epithelial chances observed throughout the nasal passages of ozone-exposed rats may be adaptive responses in an attempt to protect the upper and lower respiratory tract from further ozone-induced injury.

  1. In vitro ozone exposure increases release of arachidonic acid products from a human bronchial epithelial cell line

    SciTech Connect

    McKinnon, K.P.; Madden, M.C.; Noah, T.L.; Devlin, R.B. )

    1993-02-01

    Eicosanoids released after ozone exposure of a human bronchial epithelial cell line, BEAS-S6, were analyzed by high-pressure liquid chromatography (HPLC) of supernatants from exposed cells prelabeled with [3H]arachidonic acid. BEAS cells released thromboxane B2 (TxB2), prostaglandin E2 (PGE2), leukotriene C4 (LTC4), LTD4, LTE4, and 12-hydroxyheptadecatrienoic acid (HHT) after exposure to ozone at concentrations of 0.1, 0.25, 0.5, and 1.0 ppm. The eicosanoids were identified by coelution with authentic standards. The largest product from ozone-exposed BEAS cells was the most polar peak, designated Peak 1. Release of cyclooxygenase products such as TxB2, PGE2, and HHT was inhibited by acetylsalicylic acid. Peaks that migrated with authentic standards for LTB4, LTC4, and LTD4 were inhibited by the lipoxygenase inhibitor nordihydroguaiaretic acid. The leukotrienes LTB4 and LTC4/D4 could also be detected by immunoassay of concentrated peak fractions. Thus BEAS cells released eicosanoids from cyclooxygenase and lipoxygenase pathways of arachidonic acid metabolism following exposure to ozone. Airway epithelial cells may be an important source of eicosanoids following ozone stimulation in humans.

  2. Meta-analysis of the association between short-term exposure to ambient ozone and respiratory hospital admissions

    NASA Astrophysics Data System (ADS)

    Ji, Meng; Cohan, Daniel S.; Bell, Michelle L.

    2011-04-01

    Ozone is associated with health impacts including respiratory outcomes; however, results differ across studies. Meta-analysis is an increasingly important approach to synthesizing evidence across studies. We conducted meta-analysis of short-term ozone exposure and respiratory hospitalizations to evaluate variation across studies and explore some of the challenges in meta-analysis. We identified 136 estimates from 96 studies and investigated how estimates differed by age, ozone metric, season, lag, region, disease category, and hospitalization type. Overall results indicate associations between ozone and various kinds of respiratory hospitalizations; however, study characteristics affected risk estimates. Estimates were similar, but higher, for the elderly compared to all ages and for previous day exposure compared to same day exposure. Comparison across studies was hindered by variation in definitions of disease categories, as some (e.g., asthma) were identified through >= 3 different sets of ICD codes. Although not all analyses exhibited evidence of publication bias, adjustment for publication bias generally lowered overall estimates. Emergency hospitalizations for total respiratory disease increased by 4.47% (95% interval: 2.48, 6.50%) per 10 ppb 24 h ozone among the elderly without adjustment for publication bias and 2.97% (1.05, 4.94%) with adjustment. Comparison of multi-city study results and meta-analysis based on single-city studies further suggested publication bias.

  3. Voluntarily exposure to a single, high dose of probiotic Escherichia coli results in prolonged colonisation.

    PubMed

    Wassenaar, T M; Beimfohr, C; Geske, T; Zimmermann, K

    2014-12-01

    The ability of probiotic Escherichia coli to colonise the human gut was determined in a volunteer study following national (German) regulations. Five persons voluntarily took a single, high dose of Symbioflor®2, which contains 6 different probiotic E. coli genotypes, to assess tolerance of the product, after which presence of E. coli in their faeces was tested for a follow-up period of 30 weeks. Intake of the product did not result in severe side effect in any of the individuals, though mild side effects were observed. Stool analysis showed that the probiotic E. coli had colonised all five persons for a period of 10 to 30 weeks (mean: 18.7 weeks, median: 25.7 weeks). In two individuals there was evidence of competition between host E. coli and probiotic E. coli, while in two others total E. coli levels increased persistently with at least a factor of 10 as a result of the received dose. In one individual, who had lacked detectable levels of faecal E. coli at the start of the post-authorisation safety study, long-term colonisation was established, first by probiotic E. coli exclusively, which were later replaced by host E. coli strains. In four out of five individuals, total E. coli faecal counts were higher on average than at the start of the experiment, while in none total levels exceeded 5×107 cfu/g. When the specific genotypes of the 6 probiotic E. coli were analysed, it was found that one and the same common genotype was responsible for prolonged colonisation in all five individuals. PMID:24985025

  4. Pre-exposure to ozone predisposes oak leaves to attacks by Diplodia corticola and Biscogniauxia mediterranea.

    PubMed

    Paoletti, Elena; Anselmi, Naldo; Franceschini, Antonio

    2007-01-01

    One-year-old cork oak (Quercus suber) and turkey oak (Q. cerris) seedlings were exposed to ozone (110 ppb, 5 h day(-1), for 30 days) and were inoculated with Diplodia corticola and Biscogniauxia mediterranea, respectively, by spraying a suspension of spores on the leaves. Both fungi are endophytic and may act as weak parasites, contributing to oak decline. Ozone exposure stimulated leaf attacks after inoculation, although the physiological, visible, and structural responses of both oaks to O3 exposure were weak. In fact, steady-state gas exchange, leaf waxes, and wettability were not significantly affected by O3. In Q. cerris, O3 altered the structure of stomata, as observed by scanning microscopy, and reduced the leaf relative water content. No hyphal entry through stomata or growth towards stomata was, however, observed. Inoculations were performed in a humid chamber at low light; stomata were likely to be closed. When Q. cerris was inoculated in natural conditions, i.e., in a forest infected by B. mediterranea, seedlings pre-exposed to the enhanced O3 regime had a higher number of B. mediterranea isolates than the controls. This suggests that pre-exposure to O3 predisposed Q. cerris leaves to attacks by B. mediterranea independent of stomata. The hyphae of both fungi were able to enter the leaf through the cuticle, either by gradual in-growth into the cuticle or erosion of a hollow in the cuticle at the point of contact. The primary cause of increased leaf injury in O3-exposed seedlings appeared to be higher germination of spores than on control leaves. PMID:17450300

  5. Changes in cerebral vascular reactivity and structure following prolonged exposure to high altitude in humans.

    PubMed

    Foster, Glen E; Davies-Thompson, Jodie; Dominelli, Paolo B; Heran, Manraj K S; Donnelly, Joseph; duManoir, Gregory R; Ainslie, Philip N; Rauscher, Alexander; Sheel, A William

    2015-12-01

    Although high-altitude exposure can lead to neurocognitive impairment, even upon return to sea level, it remains unclear the extent to which brain volume and regional cerebral vascular reactivity (CVR) are altered following high-altitude exposure. The purpose of this study was to simultaneously determine the effect of 3 weeks at 5050 m on: (1) structural brain alterations; and (2) regional CVR after returning to sea level for 1 week. Healthy human volunteers (n = 6) underwent baseline and follow-up structural and functional magnetic resonance imaging (MRI) at rest and during a CVR protocol (end-tidal PCO2 reduced by -10, -5 and increased by +5, +10, and +15 mmHg from baseline). CVR maps (% mmHg(-1)) were generated using BOLD MRI and brain volumes were estimated. Following return to sea level, whole-brain volume and gray matter volume was reduced by 0.4 ± 0.3% (P < 0.01) and 2.6 ± 1.0% (P < 0.001), respectively; white matter was unchanged. Global gray matter CVR and white matter CVR were unchanged following return to sea level, but CVR was selectively increased (P < 0.05) in the brainstem (+30 ± 12%), hippocampus (+12 ± 3%), and thalamus (+10 ± 3%). These changes were the result of improvement and/or reversal of negative CVR to positive CVR in these regions. Three weeks of high-altitude exposure is reflected in loss of gray matter volume and improvements in negative CVR. PMID:26660556

  6. Changes in thyroid status of rats after prolonged exposure to low dose dichlorodiphenyltrichloroethane.

    PubMed

    Yaglova, N V; Yaglov, V V

    2014-04-01

    The effect of low dose dichlorodiphenyltrichloroethane (DDT), omnipresent ecotoxicant and endocrine disruptor, on the functioning of the endocrine system is an urgent problem. We studied the effect of low dose DDT on thyroid status in rats. Rats receiving DDT in a dose of 1.890±0.086 μg/kg for 6 weeks showed increased concentrations of thyroid hormones, particularly triiodothyronine, and reduced level of thyrotropin. Longer exposure reduced the production of thyroid hormones. The dynamics of thyroid status parameters during DDT treatment in a low dose was similar to changes observed during the development of hypothyroidism induced by iodine deficiency. PMID:24824690

  7. Changes in airway permeability and responsiveness after exposure to ozone. [Sheep

    SciTech Connect

    Abraham, W.M.; Delehunt, J.C.; Yerger, L.; Marchette, B.; Oliver, W. Jr.

    1984-06-01

    The relationship between airway responsiveness and the permeability of histamine through the airways in conscious sheep after exposure to ozone (O/sub 3/ was examined). Airway responsiveness was assessed by measuring the change from baseline in mean pulmonary flow resistance following a controlled 2-min inhalation challenge with 1% histamine, containing 200 ..mu..Ci/ml of (/sup 3/H)histamine. The rate of appearance of the (/sup 3/H)histamine in the plasma during inhalation challenge was used to estimate airway permeability. To perturb the airways, conscious sheep were exposed to either 0.5 or 1.0 ppm O/sub 3/ for 2 hr via an endotracheal tube. Airway responsiveness and airway permeability were measured prior to and 1 day after exposure. In six sheep exposed to 0.5 ppm O/sub 3/, increased airway responsiveness and airway permeability were obseved 1 day after exposure. Four of seven sheep exposed to 1.0 ppm O/sub 3/ had enhanced airway responsiveness and airway permeability, while the remaining three sheep showed corresponding decreases in airway responsiveness and airway permeability. Since the O/sub 3/-induced directional changes in airway responsiveness paralleled the directional changes in airway permeability in both the positive and negative directions, it was concluded that changes in airway responsiveness to inhaled histamine following exposure to O/sub 3/ may be related to concomitant changes in airway permeability to this agent.

  8. Complex study of the physiological role of cadmium. IV. Effects of prolonged dietary exposure of broiler chickens to cadmium.

    PubMed

    Bokori, J; Fekete, S; Glávits, R; Kádár, I; Koncz, J; Kövári, L

    1996-01-01

    A 274-day long cadmium (Cd) feeding trial was carried out with broiler cockerel chickens. The diet of the control group (Cd-0, n = 6) contained no added Cd, whereas to the diet of group Cd-25 and group Cd-75 (n = 10 each) 25 ppm and 75 ppm Cd was added, respectively, in the form of CdSO4. The chickens were subjected to examinations described in detail earlier (Bokori et al., 1995b). In addition, the relative mass of five different organs (heart, liver, testis, spleen and brain), expressed as % of the body mass, was also determined. The clinical, gross and histopathological examinations and the assay of organs for mineral element content led to the following main findings. The feeding of diets containing 25 or 75 ppm Cd for more than 9 months did not cause signs indicative of acute Cd toxicosis or mortality in either group. The body mass gain of group Cd-75 chickens markedly decreased. Prolonged Cd exposure of the cockerels increased the relative mass of the liver and heart and markedly decreased that of the testes. The change in mass was proportional to the Cd load. The Cd-fed chickens developed focal pathological fatty infiltration of the liver, histiocytic infiltration of the jejunal mucosa and focal lympho-histiocytic interstitial infiltration and fibrosis of the kidney, which supports the view that prolonged Cd exposure leads to the development of subacute-chronic tissue changes in the kidney. The Cd content of the organs increased by one to three orders of magnitude, in direct proportion to the Cd load. The Cd content of most organs was 2 to 3 times as high as the value reported for broilers exposed to a similar Cd load lasting for 68 days (Bokori et al., 1995b). This indicates that the degree of Cd accumulation is markedly influenced by the duration of the Cd exposure. The highest Cd content was demonstrated in the kidney (724 mg/kg of dry matter). The Cd exposure markedly lowered the Zn, Mo and B content of the bones and the Ni content of the myocardium

  9. Effects of prolonged exposure of lettuce seeds to HZE particles on orbital stations

    NASA Astrophysics Data System (ADS)

    Nevzgodina, L. V.; Maksimova, E. N.; Kaminskaya, E. V.

    In a study of the biological effects of cosmic HZE particles, lettuce (Lactuca sativa) seeds were flown on the orbital stations Salyut 6 and 7 for varying periods of time (from 40 to 457 days). The dependence of the biological damage on flight duration, physical parameters and the fact of passage of an HZE particle through the seed was estimated using the criterion of the frequency of aberrant cells. The arrangement of the flight biological container Biobloc made it possible to trace the location of tracks of individual HZE particles with Z>=6 and LET 200 keV/um. In seeds hit by HZE particles, for all exposure times, a statistically significant much higher yield of aberrant cells and also of cells containing multiple chromosome aberrations was observed than in the control material. The frequency of aberrant cells is markedly higher (by a factor of 1,5) in seeds hit than in non-hit ones. The changes of the yield of aberrant cells as a function of the absorbed dose (3.2-63.4 mGy) and the fluence (4.8-44.2 particles/cm2) are linear for the exposure duration ranging from 40 to 457 days.

  10. Reproducibility of the pulmonary function response of older men and women to a 2-hour ozone exposure

    SciTech Connect

    Bedi, J.F.; Horvath, S.M.; Drechsler-Parks, D.M.

    1988-08-01

    To test the reproducibility of the pulmonary function response to ozone exposure in older individuals, eight men and eight women, average age 62.8 years, participated in three 2-hour exposures to 0.45 ppm ozone at 23.3 C and 62.5 percent relative humidity. The first and second exposures were separated by an average time of 17.2 days, and 27.3 days separated the second and third exposures. Subjects alternated riding a bicycle ergometer for 20 minutes at an average minute ventilation of 26 liters BTPS (body temperature pressure, saturated), with 20-minute rest periods. Forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV-1), and forced expiratory flow between 25 and 75% of FVC (FEF 25-75%) were measured pre and post exposure. The reproducibility of individual pre-post changes were assessed by calculation of the best linear fit and correlation coefficients between exposures. For FVC and FEV-1, the slopes were significantly different from 1, and correlation coefficients not significantly different from zero, implying that older individuals may not respond consistently to similar ozone exposures.

  11. Effect of cadmium on blood of tilapia, Oreochromis mossambicus (Peters), during prolonged exposure

    SciTech Connect

    Ruparelia, S.G.; Verma, Y.; Saiyed, S.R. ); Rawal, U.M. )

    1990-08-01

    Cadmium is recognized as one of the most hazardous environmental pollutants and is toxic to many living organisms. Experimental and environmental exposure to cadmium has been reported to cause disease in humans and other mammals. Recent reviews on cadmium have reported on acute and subacute effects on fish, mechanisms of toxicity, the role of toxicity modifying factors and various sublethal effects, i.e., hematological and biochemical disorders. However, very little information is available on the subacute effects of cadmium on fish blood exposed in hard water. The present investigation, therefore, was carried out to observe the effects of cadmium on the blood of tilapia (Oreochromis mossambicus) in hard and alkaline water to determine whether cadmium causes changes in blood of fish kept in hard water in the same way it causes changes in blood of fish kept in soft water.

  12. Ozone exposure response for U.S. soybean cultivars: linear reductions in photosynthetic potential, biomass and yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current background ozone concentrations ([O3]) over the Northern Hemisphere’s mid-latitudes are high enough to damage crops, and are projected to increase. Soybean (Glycine max [L.] Merr.) is particularly sensitive to O3 therefore establishing an O3 exposure-threshold for damage is critical to under...

  13. Effect of Same-day Sequential Exposure to Nitrogen Dioxide and Ozone on Cardiac and Ventilatory Function in Mice

    EPA Science Inventory

    This study examines the cardiac and ventilatory effects of sequential exposure to nitrogen dioxide and then ozone. The data show that mice exposed to both gases have increased arrhythmia and breathing changes not observed in the other groups. Although the mechanisms underlying ai...

  14. RESPIRATORY RESPONSES OF SUBJECTS WITH ALLERGIC RHINITIS TO OZONE EXPOSURE AND THEIR RELATIONSHIP TO NONSPECIFIC AIRWAY REACTIVITY

    EPA Science Inventory

    Ozone exposure in man produces changes in respiratory function and symptoms. There is a large degree of unexplained intersubject variability in the magnitude of these responses. There is concern that individuals with chronic respiratory diseases may also be more responsive to ozo...

  15. PULMONARY FUNCTION AND BRONCHIAL REACTIVITY IN HUMAN SUBJECTS WITH EXPOSURE TO OZONE AND RESPIRABLE SULFURIC ACID AEROSOL

    EPA Science Inventory

    A three-year research study was conducted investigating the effects of individual and sequential exposures to ozone and sulfuric acid aerosol on pulmonary function and bronchial reactivity in human subjects. PHASE I: In healthy smokers and nonsmokers exposed for 4 hours to 98 mic...

  16. INTERPOLATION OF TEMPERATURE AND NON-URBAN OZONE EXPOSURE AT HIGH SPATIAL RESOLUTION OVER THE WESTERN UNITED STATES

    EPA Science Inventory

    In order to assess the impact of natural and anthropogenic stresses on forest ecosystems, it is necessary to interpolate air temperature and tropospheric ozone (O3) exposure values at high spatial resolution over complex terrain. The proposed interpolation approach was selected ...

  17. Cultural Adaptations of Prolonged Exposure Therapy for Treatment and Prevention of Posttraumatic Stress Disorder in African Americans

    PubMed Central

    Williams, Monnica T.; Malcoun, Emily; Sawyer, Broderick A.; Davis, Darlene M.; Bahojb Nouri, Leyla; Bruce, Simone Leavell

    2014-01-01

    Posttraumatic stress disorder (PTSD) is a highly disabling disorder, afflicting African Americans at disproportionately higher rates than the general population. When receiving treatment, African Americans may feel differently towards a European American clinician due to cultural mistrust. Furthermore, racism and discrimination experienced before or during the traumatic event may compound posttrauma reactions, impacting the severity of symptoms. Failure to adapt treatment approaches to encompass cultural differences and racism-related traumas may decrease treatment success for African American clients. Cognitive behavioral treatment approaches are highly effective, and Prolonged Exposure (PE) in particular has the most empirical support for the treatment of PTSD. This article discusses culturally-informed adaptations of PE that incorporates race-related trauma themes specific to the Black experience. These include adding more sessions at the front end to better establish rapport, asking directly about race-related themes during the assessment process, and deliberately bringing to the forefront race-related experiences and discrimination during treatment when indicated. Guidelines for assessment and the development of appropriate exposures are provided. Case examples are presented demonstrating adaptation of PE for a survivor of race-related trauma and for a woman who developed internalized racism following a sexual assault. Both individuals experienced improvement in their posttrauma reactions using culturally-informed adaptations to PE. PMID:25379272

  18. Persistence of peak flow decrement in children following ozone exposures exceeding the national ambient air quality standard

    SciTech Connect

    Lioy, P.J.; Vollmuth, T.A.; Lippmann, M.

    1985-10-01

    A linear regression was calculated between the peak one-hour ozone concentration for a given day and forced vital capacity (FVC), forced expiratory volume in one second (FEV), and peak expiratory flow rate (PEFR) as determined the same day from spirograms for each of the 39 children tested on six or more days. All mean slopes were negative, except for FVC in boys, indicating a general tendency for decreased function with increasing ozone concentration. In another analysis, a summary weighted correlation coefficient between peak ozone level and each pulmonary function parameter was calculated for each of 49 children seen on four or more days. As in the regression analysis, decrements in PEFR were significantly correlated with the ozone exposure. Analysis of residuals from the regression lines provide evidence for responses of greater potential significance to the future health of the children. They indicate a different kind of response, i.e., a persistent decrement in function lasting for as much as a week after the end of a smog period of about four days' duration. The persistent effects associated with ozone could have been due to acidic sulfates as well as, or in addition to, ozone. 10 references, 2 figures, 2 tables.

  19. Relationships of ozone exposure to pine injury in the Sierra Nevada and San Bernardino Mountains of California, USA.

    PubMed

    Arbaugh, M J; Miller, P R; Carroll, J J; Takemoto, B; Procter, T

    1998-01-01

    Hourly ambient ozone exposure data and crown injury measurements were gathered in the Sierra Nevada and San Bernardino Mountains of California to develop relationships between the Ozone Injury Index (OII), the Forest Pest Management Index (FPM), chlorotic mottle, fascicle retention (OII index components) and cumulative ambient ozone indices for Pinus ponderosa Dougl. ex Laws and Pinus jeffreyi Grev. and Balf. Eleven sites located in the mixed conifer forest near ambient ozone monitoring sites were evaluated annually for 4 years. Four other sites in the San Bernardino Mountains were evaluated for 1 year. Analyses showed OII to be functionally equivalent (r2 = 0.96) to the FPM, and to depend only on fascicle retention and chlorotic mottle (R2 = 0.95) of the fourth whorl (or if four whorls are not present at the site, then the last whorl present for the majority of trees). Significant associations were found between OII and 4-year 24-h. summer SUM0, SUM06, W126 and HRS80 ozone indices. Three sites had higher levels of cumulative chlorotic mottle for individual whorls and larger numbers of trees with visible crown injury than other sites with similar cumulative ambient ozone levels. Including an indicator variable to discriminate between these two groups of sites increased R2 and decreased root mean square (RMSE) for all indices, especially SUM0 (R2 = 0.93, RMSE reduced by 46%). PMID:15093091

  20. Glucose Homeostasis During Short-term and Prolonged Exposure to High Altitudes

    PubMed Central

    Ader, Marilyn; Bergman, Richard N.

    2015-01-01

    Most of the literature related to high altitude medicine is devoted to the short-term effects of high-altitude exposure on human physiology. However, long-term effects of living at high altitudes may be more important in relation to human disease because more than 400 million people worldwide reside above 1500 m. Interestingly, individuals living at higher altitudes have a lower fasting glycemia and better glucose tolerance compared with those who live near sea level. There is also emerging evidence of the lower prevalence of both obesity and diabetes at higher altitudes. The mechanisms underlying improved glucose control at higher altitudes remain unclear. In this review, we present the most current evidence about glucose homeostasis in residents living above 1500 m and discuss possible mechanisms that could explain the lower fasting glycemia and lower prevalence of obesity and diabetes in this population. Understanding the mechanisms that regulate and maintain the lower fasting glycemia in individuals who live at higher altitudes could lead to new therapeutics for impaired glucose homeostasis. PMID:25675133

  1. Enhanced response to ozone exposure during the follicular phase of the menstrual cycle

    SciTech Connect

    Fox, S.D.; Adams, W.C.; Brookes, K.A.; Lasley, B.L. )

    1993-08-01

    Exposure to ozone (O[sub 3]), a toxic component of photochemical smog, results in significant airway inflammation, respiratory discomfort, and pulmonary function impairment. These effects can be reduced via pretreatment with anti-inflammatory agents. Progesterone, a gonadal steroid, is known to reduce general inflammation in the uterine endometrium. However, it is not known whether fluctuation in blood levels of progesterone, which are experienced during the normal female menstrual cycle, could alter O[sub 3] inflammatory-induced pulmonary responses. In this study, we tested the hypothesis that young, adult females are more responsive to O[sub 3] inhalation with respect to pulmonary function impairment during their follicular (F) menstrual phase when progesterone levels are lowest that during their mid-luteal (ML) phase when progesterone levels are highest. Nine subjects with normal ovarian function were exposed in random order for 1 hour each to filtered air and to 0.30 ppm O[sub 3] in their F and ML menstrual phases. Ozone responsiveness was measured by percent change in pulmonary function from pre- to postexposure. Significant gas concentration effects (filtered air versus O[sub 3]) were observed for forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV[sub 1]), and forced expiratory flow between 25 and 75% of FVC (FEF[sub 25-75]), showed a significant menstrual phase and gas concentration interaction effect, with larger decrements observed in the F menstrual phase when progesterone concentrations were significantly lower. We conclude that young, adult females appear to be more responsive to acute O[sub 3] exposure during the F phase than during the ML phase of their menstrual cycles. This difference in pulmonary function response could be related to the anti-inflammatory effects of increased progesterone concentrations during the luteal phase.

  2. Exposure to environmentally-relevant levels of ozone negatively influence pollen and fruit development.

    PubMed

    Gillespie, Colin; Stabler, Daniel; Tallentire, Eva; Goumenaki, Eleni; Barnes, Jeremy

    2015-11-01

    A combination of in vitro and in vivo studies on tomato (Lycopersicon esculentum Mill. cv. Triton) revealed that environmentally-relevant levels of ozone (O3) pollution adversely affected pollen germination, germ tube growth and pollen-stigma interactions - pollen originating from plants raised in charcoal-Purafil(®) filtered air (CFA) exhibited reduced germ tube development on the stigma of plants exposed to environmentally-relevant levels of O3. The O3-induced decline in in vivo pollen viability was reflected in increased numbers of non-fertilized and fertilized non-viable ovules in immature fruit. Negative effects of O3 on fertilization occurred regardless of the timing of exposure, with reductions in ovule viability evident in O3 × CFA and CFA × O3 crossed plants. This suggests O3-induced reductions in fertilization were associated with reduced pollen viability and/or ovule development. Fruit born on trusses independently exposed to 100 nmol mol(-1) O3 (10 h d(-1)) from flowering exhibited a decline in seed number and this was reflected in a marked decline in the weight and size of individual fruit - a clear demonstration of the direct consequence of the effects of the pollutant on reproductive processes. Ozone exposure also resulted in shifts in the starch and ascorbic acid (Vitamin C) content of fruit that were consistent with accelerated ripening. The findings of this study draw attention to the need for greater consideration of, and possibly the adoption of weightings for the direct impacts of O3, and potentially other gaseous pollutants, on reproductive biology during 'risk assessment' exercises. PMID:26284345

  3. Comparison of the responses of children and adults to acute ozone exposure

    SciTech Connect

    McDonnell, W.F.; Chapman, R.S.; Horstman, D.H.; Leigh, M.W.; Salaam, S.A.

    1986-07-01

    The purpose of the paper is to compare the results of two studies in which the respiratory responses of children and adults to acute ozone (O/sub 3/) exposure were measured. Forty-two 18-30 year old males were exposed for 2.5 hours in a controlled environmental chamber to either 0.0 or 0.12 ppm O3 while performing intermittent heavy exercise. Twenty-two 8-11 year old males were exposed in a similar manner to both air and 0.12 ppm O3. Measures of respiratory symptoms and function were made before and after exposure. Adults experienced an increase in the symptom cough and decrements in forced vital capacity and some measures of forced expiratory flow. Children experienced similar decrements in pulmonary function, but had no increase in symptoms. The authors concluded that as measured by pulmonary function children appear to be no more responsive to O3 exposure than are adults and may experience fewer symptoms.

  4. Age-dependent inhibition of pentobarbital sleeping time by ozone in mice and rats

    SciTech Connect

    Canada, A.T.; Calabrese, E.J.; Leonard, D.

    1986-09-01

    The effect of age on the metabolism of pentobarbital in mice and rats was investigated following exposure to 0.3 ppm of ozone for 3.75 hr. Young animals were 2.5 months of age and the mature were 18 months. The pentobarbital sleeping time was significantly prolonged following the ozone exposure in both the mice and rats when compared with an air control. No ozone effect on sleeping time was found in the young animals. The results indicate that there may be an age-related sensitivity to the occurrence of ozone-related inhibition of pentobarbital metabolism.

  5. Design considerations for ozone and acid aerosol exposure and health investigations: the Fairview Lake summer camp - photochemical smog case study

    SciTech Connect

    Lioy, P.J.; Spektor, D.; Thurston, G.; Citak, K.; Lippmann, M.; Bock, N.; Speizer, F.E.; Hayes, C.

    1987-01-01

    The health effects associated with ozone and acidic particulate sulfate exposures to active children have been and are being addressed in field epidemiological studies at summer camps in rural areas of the Northeastern US. The rationale and study design for studies, which have been conducted in Pennsylvania and New Jersey, are developed and reviewed. As background, results are summarized for human clinical and epidemiological studies and animal studies. These provided the basis for selection of health outcomes measured results from chemical characterization and transport studies are reviewed to define the criteria used for selection of a site which is effected by high ozone and acid species during photochemical smog episodes. The integration of the study design is discussed in detail by reviewing its application to the 1984 - Fairview Lake Camp Study (July 8 to August 4). The features of the camp study are reviewed, including the study population, pulmonary function procedures and analyses, air pollution monitoring instrumentation, and the site characteristics. The pollution exposure data are presented, for ozone and acidic sulfates and examined for the range and distribution concentration. Further information is provided on the intensity and duration of episodes encountered over the course of the study. Episodes occurred which had ozone and acid sulfates, ozone alone, and acid sulfates alone. 56 references, 9 figures.

  6. Simulated Sensitivity of Seasonal Ozone Exposure in the Great Lakes Region to Changes in Anthropogenic Emissions in the Presence of Interannual Variability

    SciTech Connect

    Fast, Jerome D.; Heilman, Warren E.

    2005-09-01

    A coupled meteorological and chemical modeling system with a 12-km horizontal grid spacing was used to simulate the evolution of ozone over the Great Lakes region between May and September of 1999 and 2001. Model performance was evaluated using operational surface and upper-air meteorological measurements and surface ozone data. The overall temporal and spatial variations in hourly ozone concentrations and ozone exposure from control simulations agreed reasonably well with the observations at most locations. The simulated ozone exposure was higher during the summer of 1999 than during 2001, similar to the observations. The emission projection simulation that employed the meteorological conditions of 1999 and increased anthropogenic emissions projected for the year 2020 produced increases in ozone exceeding 80 ppb over the lower peninsula of Michigan, the eastern half of the upper peninsula of Michigan, and over Ontario just north of Lake Superior and Lake Huron. Relatively large increases in ozone exceeding 60 ppb were also produced over agricultural regions. Despite the projected increase in anthropogenic emissions for the year 2020, increases in ozone exceeding 60 ppb occurred only over the lake surfaces and in central Michigan when the meteorological conditions of the summer of 2001 were applied. The meteorological conditions during the summer of 2001 were not as favorable for ozone production and did not result in increased ozone. For both summers, increases in anthropogenic emissions projected for the year 2020 decreased ozone exposure in the immediate vicinity of the largest metropolitan areas. The simulated ozone from this study will be used in the near future as input to biological models to assess the response of ozone-sensitive tree species to current and future ozone levels in the Great Lakes region.

  7. Pulmonary Epithelial Integrity in Children: Relationship to Ambient Ozone Exposure and Swimming Pool Attendance

    PubMed Central

    Lagerkvist, Birgitta Json; Bernard, Alfred; Blomberg, Anders; Bergstrom, Erik; Forsberg, Bertil; Holmstrom, Karin; Karp, Kjell; Lundstrom, Nils-Goran; Segerstedt, Bo; Svensson, Mona; Nordberg, Gunnar

    2004-01-01

    Airway irritants such as ozone are known to impair lung function and induce airway inflammation. Clara cell protein (CC16) is a small anti-inflammatory protein secreted by the nonciliated bronchiolar Clara cells. CC16 in serum has been proposed as a noninvasive and sensitive marker of lung epithelial injury. In this study, we used lung function and serum CC16 concentration to examine the pulmonary responses to ambient O3 exposure and swimming pool attendance. The measurements were made on 57 children 10–11 years of age before and after outdoor exercise for 2 hr. Individual O3 exposure was estimated as the total exposure dose between 0700 hr until the second blood sample was obtained (mean O3 concentration/m3 × hours). The maximal 1-hr value was 118 μg/m3 (59 ppb), and the individual exposure dose ranged between 352 and 914 μg/m3hr. These O3 levels did not cause any significant changes in mean serum CC16 concentrations before or after outdoor exercise, nor was any decrease in lung function detected. However, children who regularly visited chlorinated indoor swimming pools had significantly lower CC16 levels in serum than did nonswimming children both before and after exercise (respectively, 57 ± 2.4 and 53 ± 1.7 μg/L vs. 8.2 ± 2.8 and 8.0 ± 2.6 μg/L; p < 0.002). These results indicate that repeated exposure to chlorination by-products in the air of indoor swimming pools has adverse effects on the Clara cell function in children. A possible relation between such damage to Clara cells and pulmonary morbidity (e.g., asthma) should be further investigated. PMID:15579425

  8. Resistin deficiency in mice has no effect on pulmonary responses induced by acute ozone exposure.

    PubMed

    Razvi, Shehla S; Richards, Jeremy B; Malik, Farhan; Cromar, Kevin R; Price, Roger E; Bell, Cynthia S; Weng, Tingting; Atkins, Constance L; Spencer, Chantal Y; Cockerill, Katherine J; Alexander, Amy L; Blackburn, Michael R; Alcorn, Joseph L; Haque, Ikram U; Johnston, Richard A

    2015-11-15

    Acute exposure to ozone (O3), an air pollutant, causes pulmonary inflammation, airway epithelial desquamation, and airway hyperresponsiveness (AHR). Pro-inflammatory cytokines-including IL-6 and ligands of chemokine (C-X-C motif) receptor 2 [keratinocyte chemoattractant (KC) and macrophage inflammatory protein (MIP)-2], TNF receptor 1 and 2 (TNF), and type I IL-1 receptor (IL-1α and IL-1β)-promote these sequelae. Human resistin, a pleiotropic hormone and cytokine, induces expression of IL-1α, IL-1β, IL-6, IL-8 (the human ortholog of murine KC and MIP-2), and TNF. Functional differences exist between human and murine resistin; yet given the aforementioned observations, we hypothesized that murine resistin promotes O3-induced lung pathology by inducing expression of the same inflammatory cytokines as human resistin. Consequently, we examined indexes of O3-induced lung pathology in wild-type and resistin-deficient mice following acute exposure to either filtered room air or O3. In wild-type mice, O3 increased bronchoalveolar lavage fluid (BALF) resistin. Furthermore, O3 increased lung tissue or BALF IL-1α, IL-6, KC, TNF, macrophages, neutrophils, and epithelial cells in wild-type and resistin-deficient mice. With the exception of KC, which was significantly greater in resistin-deficient compared with wild-type mice, no genotype-related differences in the other indexes existed following O3 exposure. O3 caused AHR to acetyl-β-methylcholine chloride (methacholine) in wild-type and resistin-deficient mice. However, genotype-related differences in airway responsiveness to methacholine were nonexistent subsequent to O3 exposure. Taken together, these data demonstrate that murine resistin is increased in the lungs of wild-type mice following acute O3 exposure but does not promote O3-induced lung pathology. PMID:26386120

  9. Pulmonary epithelial integrity in children: relationship to ambient ozone exposure and swimming pool attendance.

    PubMed

    Lagerkvist, Birgitta Json; Bernard, Alfred; Blomberg, Anders; Bergstrom, Erik; Forsberg, Bertil; Holmstrom, Karin; Karp, Kjell; Lundstrom, Nils-Goran; Segerstedt, Bo; Svensson, Mona; Nordberg, Gunnar

    2004-12-01

    Airway irritants such as ozone are known to impair lung function and induce airway inflammation. Clara cell protein (CC16) is a small anti-inflammatory protein secreted by the nonciliated bronchiolar Clara cells. CC16 in serum has been proposed as a noninvasive and sensitive marker of lung epithelial injury. In this study, we used lung function and serum CC16 concentration to examine the pulmonary responses to ambient O3 exposure and swimming pool attendance. The measurements were made on 57 children 10-11 years of age before and after outdoor exercise for 2 hr. Individual O3 exposure was estimated as the total exposure dose between 0700 hr until the second blood sample was obtained (mean O3 concentration/m3 times symbol hours). The maximal 1-hr value was 118 microg/m3 (59 ppb), and the individual exposure dose ranged between 352 and 914 microg/m3hr. These O3 levels did not cause any significant changes in mean serum CC16 concentrations before or after outdoor exercise, nor was any decrease in lung function detected. However, children who regularly visited chlorinated indoor swimming pools had significantly lower CC16 levels in serum than did nonswimming children both before and after exercise (respectively, 57 +/- 2.4 and 53 +/- 1.7 microg/L vs. 8.2 +/- 2.8 and 8.0 +/- 2.6 microg/L; p < 0.002). These results indicate that repeated exposure to chlorination by-products in the air of indoor swimming pools has adverse effects on the Clara cell function in children. A possible relation between such damage to Clara cells and pulmonary morbidity (e.g., asthma) should be further investigated. PMID:15579425

  10. Skin wound trauma, following high-dose radiation exposure, amplifies and prolongs skeletal tissue loss.

    PubMed

    Swift, Joshua M; Swift, Sibyl N; Smith, Joan T; Kiang, Juliann G; Allen, Matthew R

    2015-12-01

    The present study investigated the detrimental effects of non-lethal, high-dose (whole body) γ-irradiation on bone, and the impact that radiation combined with skin trauma (i.e. combined injury) has on long-term skeletal tissue health. Recovery of bone after an acute dose of radiation (RI; 8 Gy), skin wounding (15-20% of total body skin surface), or combined injury (RI+Wound; CI) was determined 3, 7, 30, and 120 days post-irradiation in female B6D2F1 mice and compared to non-irradiated mice (SHAM) at each time-point. CI mice demonstrated long-term (day 120) elevations in serum TRAP 5b (osteoclast number) and sclerostin (bone formation inhibitor), and suppression of osteocalcin levels through 30 days as compared to SHAM (p<0.05). Radiation-induced reductions in distal femur trabecular bone volume fraction and trabecular number through 120 days post-exposure were significantly greater than non-irradiated mice (p<0.05) and were exacerbated in CI mice by day 30 (p<0.05). Negative alterations in trabecular bone microarchitecture were coupled with extended reductions in cancellous bone formation rate in both RI and CI mice as compared to Sham (p<0.05). Increased osteoclast surface in CI animals was observed for 3 days after irradiation and remained elevated through 120 days (p<0.01). These results demonstrate a long-term, exacerbated response of bone to radiation when coupled with non-lethal wound trauma. Changes in cancellous bone after combined trauma were derived from extended reductions in osteoblast-driven bone formation and increases in osteoclast activity. PMID:26335157

  11. Prolonged exposure to low levels of aluminum leads to changes associated with brain aging and neurodegeneration.

    PubMed

    Bondy, Stephen C

    2014-01-01

    Aluminum is one of the most common metal elements in the earth's crust. It is not an essential element for life and has commonly been thought of as a rather inert and insoluble mineral. Therefore, it has often been regarded as not posing a significant health hazard. In consequence, aluminum-containing agents been used in many food processing steps and also in removal by flocculation of particulate organic matter from water. In recent years, acid rain has tended to mobilize aluminum-containing minerals into a more soluble form, ionic Al(3+), which has found their way into many reservoirs that constitute residential drinking water resources. As a result, the human body burden of aluminum has increased. Epidemiological studies suggest that aluminum may not be as innocuous as was previously thought and that aluminum may actively promote the onset and progression of Alzheimer's disease. Epidemiological data is strengthened by experimental evidence of aluminum exposure leading to excess inflammatory activity within the brain. Such apparently irrelevant immune activity unprovoked by an exogenous infectious agent characterizes the aging brain and is even more pronounced in several neurodegenerative diseases. The causation of most of these age-related neurological disorders is not understood but since they are generally not genetic, one must assume that their development is underlain by unknown environmental factors. There is an increasing and coherent body of evidence that implicates aluminum as being one such significant factor. Evidence is outlined supporting the concept of aluminum's involvement in hastening brain aging. This acceleration would then inevitably lead to increased incidence of specific age-related neurological diseases. PMID:24189189

  12. The immune response of women with prolonged exposure to electromagnetic fields produced by radiotelevision broadcasting stations.

    PubMed

    Boscolo, P; Di Giampaolo, L; Di Donato, A; Antonucci, A; Paiardini, G; Morelli, S; Vasile, R; Spagnoli, G; Reale, M; Dadorante, V; Kouri, M; Di Gioacchino, M

    2006-01-01

    Twelve women, five of them housewives, exposed in their residences to electromagnetic fields (EMFs)emitted by radio-television broadcasting stations for a mean period of 13 years, were investigated. The EMFs in the balconies of the homes were (mean + S.D.) 4.3 + 1.4 V/m in the year 2000 and 3.7 + 1.3 V/m in 2005, while the exposure in the nearby area was <2.0 V/m. The EMF exposed women showed in 2000 reduced blood NK lymphocytes as well as PHA stimulated PBMC proliferation and IL-2 and IFN-gamma release. In the year 2005, the EMF exposed women and 48 control women with similar ages(mean 43 years), smoking habits, atopy and social level were investigated. State (temporary) and trait(tendency of the personality) anxiety were determined by STAI I and II, respectively. Blood cytotoxic activity and lymphocyte subsets were also determined. The ratio STAI I/STAI II of the EMF exposed group was lower than that of the control group. The blood cytotoxic activity of the exposed women was lower (p<0.01), percent of B CD45+-CD19+ lymphocytes higher and percent of CD45+-CD3+-CD8+ cells lower (p<0.05). Moreover, cytotoxic activity/CD45+-CD16+-56+ NK lymphocytes of the controls was negatively correlated with STAI I and STAI II (p<0.001). In conclusion, this study demonstrates reduced blood cytotoxic activity and increased trait anxiety in relation to state anxiety in EMF exposed women. An effect of EMFs on immune functions, in part mediated by nervous mechanisms, may be hypothesized. However, the influence of lifestyle may not be excluded. PMID:17291406

  13. Changes in the carbon dioxide expirogram in response to ozone exposure

    SciTech Connect

    Taylor, Adekemi B.; Lee, Genea M.; Nellore, Kavitha; Ben-Jebria, Abdellaziz . E-mail: axb23@psu.edu; Ultman, James S.

    2006-05-15

    The objectives of this study were to quantify pulmonary responses to ozone (O{sub 3}) exposure by parameters computed from the carbon dioxide expirogram and to compare these responses to decrements in forced expired spirometry. Anatomical dead space (V {sub D}) was determined from the pure dead space and transition regions of the expirogram. Four alternative parameters were computed from the alveolar plateau: slope (S), normalized slope (NS), peripheral cross-sectional area (A {sub P}) and well-mixed peripheral volume (V {sub MP}). Forty-seven healthy nonsmokers (25 men and 22 women) participated in two research sessions in which they exercised on a cycle ergometer for 1 h while orally inhaling either room air at a minute ventilation of 30.6 {+-} 3.6 L or room air mixed with 0.252 {+-} 0.029 ppm O{sub 3} at a minute ventilation of 29.9 {+-} 3.7 L. Carbon dioxide expirograms were measured before exposure, 10 min after exposure and 70 min after exposure. Percent changes (mean {+-} SD) in expirogram parameters were significant (P {<=} 0.002) at both 10 and 70 min after O{sub 3} exposure: V {sub D}(-4.2 {+-} 5.1, -3.3 {+-} 6.9), S(16.4 {+-} 17.9, +15.1 {+-} 20.2), NS(17.5 {+-} 15.4, +15.9 {+-} 19.2), A {sub P}(-8.1 {+-} 7.6, -7.7 {+-} 9.8) and V {sub MP}(-15.4 {+-} 13.0, -13.0 {+-} 15.2). Percent decrements of forced expired volume in one second (FEV{sub 1}) were also significant at both 10 min (-13.3 {+-} 13.4) and 70 min (-11.1 {+-} 9.2) following O{sub 3} exposure. Changes in the expirogram as well as decrements in FEV{sub 1} were not significant at either time point after air exposure. Thus, the CO{sub 2} expirogram is useful for characterizing the effect of O{sub 3} exposure on gas transport, and for supplementing forced expired spirometry that is frequently used to quantify lung mechanics.

  14. Ozone Exposure-Response in Field Grown Soybean: Characterizing Intraspecific Variability of Physiology and Biochemistry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop losses due to rising tropospheric ozone concentrations ([ozone]) in 2000 were estimated to cost $1.8 to $3.9 billion in the U.S. and $3.0 to $5.5 billion in China, and are expected to grow with the predicted 25% increase in background [ozone] over the next 30 to 50 years. This challenge provide...

  15. Overexpression of hsp27 Rescued Neuronal Cell Death and Reduction in Life- and Health-Span in Drosophila melanogaster Against Prolonged Exposure to Dichlorvos.

    PubMed

    Pandey, Ashutosh; Saini, Sanjay; Khatoon, Rehana; Sharma, Divya; Narayan, Gopeshwar; Kar Chowdhuri, Debapratim

    2016-07-01

    Long-term exposure to dichlorvos (O,O-dimethyl-2,2-dichlorovinyl phosphate (DDVP), an organophosphate pesticide) is reported to exert neurotoxicity, i.e., generation of reactive oxygen species (ROS), oxidative damage, and neuronal cell death along with life- and health-span reduction in nontarget organisms including humans. However, studies on genetic modulation towards neuroprotection against prolonged DDVP exposure are elusive. Hsp27 (a small heat shock protein) is involved in various cellular processes and thus has attained emphasis as a therapeutic target. We aimed to examine the protective effect of hsp27 overexpression against prolonged DDVP exposure using an in vivo model Drosophila melanogaster. Flies were exposed to 15.0 ng/ml DDVP for a prolonged period to examine neuronal cell death, locomotor performance, and lifespan. After prolonged exposure, cell death, ROS level, glutathione depletion, nicotinamide adenine dinucleotide phosphate level (NADPH), glucose-6-phosphate dehydrogenase (G6PD), and thioredoxin reductase (TrxR) activities were examined in fly brain tissues at different days of age (days 10, 20, and 30). Flies with ubiquitous overexpression of hsp27 showed better resistance (improved lifespan and locomotor performance) in comparison to that targeted to motor neurons and nervous system. These flies also exhibited lesser intracellular ROS level and glutathione depletion by restoring G6PD activity, NADPH level, and TrxR activity in their brains thereby resisted neuronal cell death. Conversely, hsp27 knockdown flies exhibited reversal of the above endpoints. The study evidenced the neuroprotective efficacy of hsp27 overexpression against prolonged DDVP exposure and favored Hsp27 as a therapeutic target towards achieving better organismal (including human) health against long-term chemical exposure. PMID:26033218

  16. Susceptibility to ozone-induced inflammation. I. Genetic control of the response to subacute exposure

    SciTech Connect

    Kleeberger, S.R.; Levitt, R.C.; Zhang, L.Y. )

    1993-01-01

    We demonstrated previously that C57BL/6J (B6) inbred mice are susceptible and C3H/HeJ (C3) mice are resistant to airway inflammation that is induced by acute (3 h) exposure to 2 parts per million (ppm) ozone (O3). In the present study we tested the hypothesis that B6 and C3 mice are also differentially susceptible to the airway inflammatory responses to subacute (72 h) exposure to environmentally relevant concentrations of O3 (0.12 and 0.30 ppm). Male mice (20-25 g, 5-7 wk) were exposed continuously to 0.12 ppm O3, 0.30 ppm O3, or filtered air (control). Pulmonary inflammation was assessed after 24, 48, and 72 h by differential cell count and total protein in bronchoalveolar lavage (BAL) returns. Exposure to 0.12 ppm O3 caused significant influx of alveolar macrophages, polymorphonuclear leukocytes (PMNs), lymphocytes, and total BAL protein in both strains, but no differences in the magnitude of the responses were found between B6 and C3 mice. In contrast to the effect of 0.12 ppm O3, exposure to 0.30 ppm O3 elicited significantly greater numbers of inflammatory cells and BAL protein concentration in B6 mice relative to C3 mice. The phenotypes of the B6 and C3 mice were termed susceptible and resistant, respectively. To further evaluate the potential genetic contribution to the inflammatory response to 0.30 ppm O3, the F1, F2, and backcross progeny from B6 and C3 progenitors were examined. The ratios of susceptible and resistant phenotypes of these progeny support the hypothesis that a single autosomal recessive gene confers susceptibility to subacute O3-induced inflammation.

  17. Hypoxia-induced pulmonary arterial hypertension augments lung injury and airway reactivity caused by ozone exposure.

    PubMed

    Zychowski, Katherine E; Lucas, Selita N; Sanchez, Bethany; Herbert, Guy; Campen, Matthew J

    2016-08-15

    Ozone (O3)-related cardiorespiratory effects are a growing public health concern. Ground level O3 can exacerbate pre-existing respiratory conditions; however, research regarding therapeutic interventions to reduce O3-induced lung injury is limited. In patients with chronic obstructive pulmonary disease, hypoxia-associated pulmonary hypertension (HPH) is a frequent comorbidity that is difficult to treat clinically, yet associated with increased mortality and frequency of exacerbations. In this study, we hypothesized that established HPH would confer vulnerability to acute O3 pulmonary toxicity. Additionally, we tested whether improvement of pulmonary endothelial barrier integrity via rho-kinase inhibition could mitigate pulmonary inflammation and injury. To determine if O3 exacerbated HPH, male C57BL/6 mice were subject to either 3 weeks continuous normoxia (20.9% O2) or hypoxia (10.0% O2), followed by a 4-h exposure to either 1ppm O3 or filtered air (FA). As an additional experimental intervention fasudil (20mg/kg) was administered intraperitoneally prior to and after O3 exposures. As expected, hypoxia significantly increased right ventricular pressure and hypertrophy. O3 exposure in normoxic mice caused lung inflammation but not injury, as indicated by increased cellularity and edema in the lung. However, in hypoxic mice, O3 exposure led to increased inflammation and edema, along with a profound increase in airway hyperresponsiveness to methacholine. Fasudil administration resulted in reduced O3-induced lung injury via the enhancement of pulmonary endothelial barrier integrity. These results indicate that increased pulmonary vascular pressure may enhance lung injury, inflammation and edema when exposed to pollutants, and that enhancement of pulmonary endothelial barrier integrity may alleviate such vulnerability. PMID:27286659

  18. Repeated Ozone Exposure Exacerbates Insulin Resistance And Activates Innate Immune Response In Genetically Susceptible Mice

    PubMed Central

    Zhong, Jixin; Allen, Katryn; Rao, Xiaoquan; Ying, Zhekang; Braunstein, Zachary; Kankanala, Saumya R.; Xia, Chang; Wang, Xiaoke; Bramble, Lori A.; Wagner, James G.; Lewandowski, Ryan; Sun, Qinghua; Harkema, Jack R.; Rajagopalan, Sanjay

    2016-01-01

    Background Inhaled ozone (O3) has been demonstrated as a harmful pollutant and associated with chronic inflammatory diseases such as diabetes and vascular disorders. However, the underlying mechanisms by which O3 mediates harmful effects are poorly understood. Objectives To investigate the effect of O3 exposure on glucose intolerance, immune activation and underlying mechanisms in a genetically susceptible mouse model. Methods Diabetes-prone KK mice were exposed to filtered air (FA), or O3 (0.5 ppm) for 13 consecutive weekdays (4 h/day). Insulin tolerance test (ITT) was performed following the last exposure. Plasma insulin, adiponectin, and leptin were measured by ELISA. Pathologic changes were examined by H&E and oil-red-o staining. Inflammatory responses were detected using flow cytometry and real-time PCR. Results KK mice exposed to O3 displayed an impaired insulin response. Plasma insulin and leptin levels were reduced in O3-exposed mice. Three-week exposure to O3 induced lung inflammation and increased monocytes/macrophages in both blood and visceral adipose tissue. Inflammatory monocytes/macrophages increased both systemically and locally. CD4+ T cell activation was also enhanced by the exposure of O3 although the relative percentage of CD4+ T cell decreased in blood and adipose tissue. Multiple inflammatory genes including CXCL-11, IFN-γ, TNFα, IL-12, and iNOS were up-regulated in visceral adipose tissue. Furthermore, the expression of oxidative stress-related genes such as Cox4, Cox5a, Scd1, Nrf1, and Nrf2, increased in visceral adipose tissue of O3-exposed mice. Conclusions Repeated O3 inhalation induces oxidative stress, adipose inflammation and insulin resistance. PMID:27240593

  19. Treating Low-Income and Minority Women with Posttraumatic Stress Disorder: A Pilot Study Comparing Prolonged Exposure and Treatment as Usual Conducted by Community Therapists

    ERIC Educational Resources Information Center

    Feske, Ulrike

    2008-01-01

    Twenty-one female psychiatric outpatients with chronic posttraumatic stress disorder (PTSD) are randomly assigned to prolonged exposure (PE; n = 9) for PTSD or treatment as usual (TAU; n = 12). Participants are predominately low income and African American with complex trauma and psychiatric histories. Treatment is delivered by community…

  20. The Relationship between Posttraumatic and Depressive Symptoms during Prolonged Exposure with and without Cognitive Restructuring for the Treatment of Posttraumatic Stress Disorder

    ERIC Educational Resources Information Center

    Aderka, Idan M.; Gillihan, Seth J.; McLean, Carmen P.; Foa, Edna B.

    2013-01-01

    Objective: In the present study, we examined the relationship between posttraumatic and depressive symptoms during prolonged exposure (PE) treatment with and without cognitive restructuring (CR) for the treatment of posttraumatic stress disorder (PTSD). Method: Female assault survivors (N = 153) with PTSD were randomized to either PE alone or PE…

  1. Characteristics of physiological and biochemical responses of soybean cultivars to short term ozone exposures

    SciTech Connect

    Sheng, Wen; Chevone, B. )

    1990-05-01

    The differential sensitivity to ozone based on the degree of visible injury among soybean (Glycine max (L.) Merr.) cvs: Dare (O{sub 3}-sensitive), Williams and Essex was investigated. Gas exchange measurements using a portable Li-Cor 6200 Photosynthesis System revealed that cv Essex maintained a higher net photosynthetic rate (Pn) than cvs Williams and Dare during a 4 hr fumigation with 0.2 {mu}l l{sup {minus}1} O{sub 3}. However, cv Dare had a higher stomatal conductance (Cs) than the other cvs during the exposure period suggesting a higher O{sub 3} influx into the leaf tissues. The maximum reductions in Pn and Cs of all cvs by O{sub 3} were approximately 30% and 70%, respectively. The antioxidant system, consisting of the metabolites: glutathione (GSH and GSSG) and ascorbic acid (AA and dHAA), and the enzymes: glutathione reductase (GRase), ascorbate peroxidase (APase) and superoxide dismutase (SOD), was found to be different in the endogenous levels or activities among cvs. There were no significant changes caused by O{sub 3} exposure, however, trends in metabolite concentrations and enzyme activities were evident. Most notably, O{sub 3} resulted in decreases of dHAA in cvs Dare and Williams, AA in cv Essex and GSSG in cv Williams and increases of GSSG in cv Essex, AA in cvs Dare and Williams and SOD in cv Dare.

  2. Chamber exposures of children to mixed ozone, sulfur dioxide, and sulfuric acid.

    PubMed

    Linn, W S; Gong, H; Shamoo, D A; Anderson, K R; Avol, E L

    1997-01-01

    To help assess acute health effects of summer air pollution in the eastern United States, we simulated ambient "acid summer haze" as closely as was practical in a laboratory chamber. We exposed young volunteers who were thought to be sensitive to this pollutant mixture on the basis of previous epidemiologic evidence. Specifically, we exposed 41 subjects aged 9-12 y to mixed ozone (0.10 ppm), sulfur dioxide (0.10 ppm), and 0.6-microm sulfuric acid aerosol (100 +/- 40 microg/m3, mean +/- standard deviation) for 4 h, during which there was intermittent exercise. Fifteen subjects were healthy, and 26 had allergy or mild asthma. The entire group responded nonsignificantly (p > .05) to pollution exposure (relative to clean air), as determined by spirometry, symptoms, and overall discomfort level during exercise. Subjects with allergy/asthma showed a positive association (p = .01) between symptoms and acid dose; in healthy subjects, that association was negative (p = .08). In these chamber-exposure studies, we noted less of an effect than was reported in previous epidemiologic studies of children exposed to ambient "acid summer haze." PMID:9169627

  3. Exposure to a Mixture of Polychlorinated Biphenyls and Polychlorinated Dibenzofurans Resulted in a Prolonged Time to Pregnancy in Women

    PubMed Central

    Yang, Chiu-Yueh; Wang, Ying-Jan; Chen, Pau-Chung; Tsai, Shaw-Jenq; Guo, Yueliang Leon

    2008-01-01

    Background Polychlorinated biphenyls (PCBs), dibenzofurans (PCDFs), and dibenzodioxins (PCDDs) may affect the female reproductive system in animals and humans. In 1978–1979, a mass poisoning occurred in central Taiwan due to PCB/PCDF-contaminated cooking oil; this incident was called Yucheng (“oil disease” in Chinese). Objective The purpose of our study was to determine whether PCB/PCDF exposure affected fertility in exposed women. Methods After the event, we followed the exposed individuals and a reference group who were sex-, age-, and community-matched. In 2003, we obtained fertility histories from Yucheng and reference women by telephone interview. We used Kaplan–Meier survival curves and multivariable Cox regression to compare time to pregnancy (TTP) between Yucheng and reference women, and we performed multiple logistic regression to determine whether PCB/PCDF exposure caused infertility. Results In total, 412 women responded, with a median TTP of 4 months in Yucheng women and 3 months in reference women (p = 0.019). After adjusting for confounders by Cox regression, we found a fecundability ratio of 0.90 [95% confidence interval (CI), 0.80–1.00] for Yucheng women. Among the 408 women who had noncontraceptive sexual activity for > 12 months, 19.7% of Yucheng women and 9.7% of reference women did not become pregnant (i.e., they were infertile). After we adjusted for confounders by logistic regression, the infertility odds ratio was 2.34 (95% CI, 1.23–4.59) for Yucheng women compared with the reference group. Conclusions We found prolonged TTP and reduced fertility among women previously exposed to PCBs/PCDFs. Because of the limited sample size and the relatively small decrease in the fertility rate, these effects require cautious interpretation and further investigation for confirmation. PMID:18470317

  4. Prolonged Exposure for Treating PTSD Among Female Methadone Patients Who Were Survivors of Sexual Abuse in Israel.

    PubMed

    Schiff, Miriam; Nacasch, Nitsa; Levit, Shabtay; Katz, Noam; Foa, Edna B

    2015-01-01

    The aims of this pilot study were: (a) to test the feasibility of prolonged exposure (PE) therapy conducted by a social worker staff on female patients in methadone program clinics who were survivors of child sexual abuse or rape and (b) to examine preliminary outcomes of PE on posttraumatic stress disorder (PTSD), depression, and illicit drug use at pre- and posttreatment, and up to 12-month follow-ups. Twelve female methadone patients who were survivors of child sexual abuse or rape diagnosed with PTSD were enrolled in 13-19 weekly individual PE sessions. Assessments were conducted at pre-, mid-, and posttreatment, as well as at 3, 6, and 12-month follow-ups. The treatment outcomes measures included PTSD symptoms, depressive symptoms, and illicit drug use. Ten of the 12 study patients completed treatment. PTSD and depressive symptoms showed significant reduction. No relapse to illicit drug use was detected. These preliminary results suggest that PE may be delivered by methadone social workers with successful outcomes. Further research should test the efficacy of PE among methadone patients in a randomized control trial with standard care as the control condition. PMID:26399489

  5. Static torsional otolith-cervical-ocular reflex after prolonged exposure to weightlessness and a 7-day immersion

    NASA Astrophysics Data System (ADS)

    Kornilova, L. N.; Naumov, I. A.; Makarova, S. M.

    2011-05-01

    To determine the role of the support-proprioceptive factor in the functioning of the vestibular system, in particular the static torsional otolith-cervical-ocular reflex (OCOR), comparative OCOR studies with videooculography recording were performed after a 7-day "dry" horizontal immersion (16 subjects) and after a prolonged (126-195 days) exposure to weightlessness (13 cosmonauts). For the first time, it was demonstrated that minimization of the support and proprioceptive afferentation may result in an inversion or absence of the static torsional OCOR and the development of a positional nystagmus with an inverted reflex. A comparative OCOR data analysis of cosmonauts and immersion subjects has revealed similarity of responses. However, changes in OCOR after immersion were noted in only 60% of the subjects, while after space flight, 90% of cosmonauts showed them. Post-flight changes were more frequent, marked and long-lasting. Statistical analysis has shown that there were significant differences between pre- and post-flight data according to both parametric and non-parametric methods of multiple comparisons, whereas only parametric methods have found significant differences within immersion data.

  6. Estimating the national public health burden associated with exposure to ambient PM2.5 and ozone.

    PubMed

    Fann, Neal; Lamson, Amy D; Anenberg, Susan C; Wesson, Karen; Risley, David; Hubbell, Bryan J

    2012-01-01

    Ground-level ozone (O(3)) and fine particulate matter (PM(2.5)) are associated with increased risk of mortality. We quantify the burden of modeled 2005 concentrations of O(3) and PM(2.5) on health in the United States. We use the photochemical Community Multiscale Air Quality (CMAQ) model in conjunction with ambient monitored data to create fused surfaces of summer season average 8-hour ozone and annual mean PM(2.5) levels at a 12 km grid resolution across the continental United States. Employing spatially resolved demographic and concentration data, we assess the spatial and age distribution of air-pollution-related mortality and morbidity. For both PM(2.5) and O(3) we also estimate: the percentage of total deaths due to each pollutant; the reduction in life years and life expectancy; and the deaths avoided according to hypothetical air quality improvements. Using PM(2.5) and O(3) mortality risk coefficients drawn from the long-term American Cancer Society (ACS) cohort study and National Mortality and Morbidity Air Pollution Study (NMMAPS), respectively, we estimate 130,000 PM(2.5) -related deaths and 4,700 ozone-related deaths to result from 2005 air quality levels. Among populations aged 65-99, we estimate nearly 1.1 million life years lost from PM(2.5) exposure and approximately 36,000 life years lost from ozone exposure. Among the 10 most populous counties, the percentage of deaths attributable to PM(2.5) and ozone ranges from 3.5% in San Jose to 10% in Los Angeles. These results show that despite significant improvements in air quality in recent decades, recent levels of PM(2.5) and ozone still pose a nontrivial risk to public health. PMID:21627672

  7. Repeated subacute ozone exposure of inbred mice: Airway inflammation and ventilation

    SciTech Connect

    Paquette, N.C.; Tankersley, C.G.; Zhang, L.Y.

    1994-11-01

    The present study was designed to assess the effects of repeated subacute ozone (O{sub 3}) exposure on pulmonary inflammation and ventilation in two inbred strains of mice differentially susceptible to a single O{sub 3} exposure. Susceptible C57BL/6J(B6) and resistant C3H/HeJ (C3) mice were exposed to 0.3 ppm O{sub 3} for 48 and 72 h and, after 14 days recovery, both strains were reexposed. Airway inflammation and lung injury were assessed by counting inflammatory cells and measuring total protein content and lactate dehydrogenase (LDH) activity in bronchoalveolar lavage (BAL) returns. Minute ventilation [V{sub E,} the product of breathing frequency (f), and tidal volume (V{sub T})] was measured prior to and immediately following each exposure. After the initial exposure, B6 mice developed greater O{sub 3}-induced increases in total protein, inflammatory cell influx, and LDH activity compared to C3 mice. In normal air, V{sub E} was also significantly elevated in B6, but not C3, mice after O{sub 3}. The hypercapnic f of B6 and hypercapnic V{sub T} of C3 mice were significantly altered after O{sub 3} exposure. Reexposure to O{sub 3} caused a smaller increase in the numbers of macrophages, lymphocytes, epithelial cells, and BAL protein in both strains, and no changes in LDH activity. However, the number of polymorphonuclear leukocytes significantly increased in B6 and C3 mice as compared to the initial O{sub 3} exposure. In both strains, the ventilatory responses to normal air or hypercapnia were largely reproducible after O{sub 3} reexposure. Results indicated that differential susceptibility to O{sub 3}-induced inflammation was maintained in B6 and C3 mice with O{sub 3} reexposure although the magnitude of the difference was reduced. Results also suggest that the ventilatory responses to O{sub 3} in B6 and C3 mice were reproducible with reexposure, and that airway inflammation and ventilation were not codependent. 34 refs., 4 figs., 1 tab.

  8. Sensory Neural Responses to Ozone Exposure during Early Postnatal Development in Rat Airways

    PubMed Central

    Hunter, Dawn D.; Wu, Zhongxin; Dey, Richard D.

    2010-01-01

    Airway infections or irritant exposures during early postnatal periods may contribute to the onset of childhood asthma. The purpose of this study was to examine critical periods of postnatal airway development during which ozone (O3) exposure leads to heightened neural responses. Rats were exposed to O3 (2 ppm) or filtered air for 1 hour on specific postnatal days (PDs) between PD1 and PD29, and killed 24 hours after exposure. In a second experiment, rats were exposed to O3 on PD2–PD6, inside a proposed critical period of development, or on PD19–PD23, outside the critical period. Both groups were re-exposed to O3 on PD28, and killed 24 hours later. Airways were removed, fixed, and prepared for substance P (SP) immunocytochemistry. SP nerve fiber density (NFD) in control extrapulmonary (EXP) epithelium/lamina propria (EPLP) increased threefold, from 1% to 3.3% from PD1–PD3 through PD13–PD15, and maintained through PD29. Upon O3 exposure, SP-NFD in EXP–smooth muscle (SM) and intrapulmonary (INT)-SM increased at least twofold at PD1–PD3 through PD13–PD15 in comparison to air exposure. No change was observed at PD21–PD22 or PD28–PD29. In critical period studies, SP-NFD in the INT-SM and EXP-SM of the PD2–PD6 O3 group re-exposed to O3 on PD28 was significantly higher than that of the group exposed at PD19–PD23 and re-exposed at PD28. These findings suggest that O3-mediated changes in sensory innervation of SM are more responsive during earlier postnatal development. Enhanced responsiveness of airway sensory nerves may be a contributing mechanism of increased susceptibility to environmental exposures observed in human infants and children. PMID:20118220

  9. Pulmonary Function Response to Exposure to Low Concentration Ozone in Young Adults: Inter-comparison among Studies and Meta-Analysis

    EPA Science Inventory

    Rationale: It is well established that moderate ozone exposures induce decrements in spirometry volume and respiratory symptoms in healthy young adults. However, studies for low concentration ozone near the current NAAQS standard (0.070 ppm) are limited to only a few and their co...

  10. Alteration of extracellular enzymes in pinto bean leaves upon exposure to air pollutants, ozone and sulfur dioxide

    SciTech Connect

    Peters, J.L.; Castillo, F.J.; Heath, R.L. )

    1989-01-01

    Diamine oxidase and peroxidase, associated with the wall in pinto bean (Phaseolus vulgaris L. var Pinto) leaves, can be washed out by vacuum infiltration and assayed without grinding the leaf. The diamine oxidase activity is inhibited in vivo by exposure of the plants to ozone (dose of 0.6 microliters per liter {times} hour), whereas the peroxidase activity associated with the wall space is stimulated. This dose does not cause obvious necrosis or chlorosis of the leaf. These alterations are greater when the dose of ozone exposure is given as a triangular pulse (a slow rise to a peak of 0.24 microliters per liter followed by a slow fall) compared to that given as a constant square wave pulse of 0.15 microliters per liter for the same 4 hour period. Exposure of the plants to sulfur dioxide (at a concentration of 0.4 microliters per liter for 4 hours) does not result in any change in the diamine oxidase or peroxidase activities, yet the total sulfhydryl content of the leaf is increased, demonstrating the entry of sulfur dioxide. These two pollutants, with different chemical reactivities, affect the activities of the extracellular enzymes in different manners. In the case of ozone exposure, the inhibition of extracellular diamine oxidase could profoundly alter the movements of polyamines from cell to cell.

  11. Air pollution and childhood respiratory health: Exposure to sulfate and ozone in 10 Canadian Rural Communities

    SciTech Connect

    Stern, B.R.; Raizenne, M.E.; Burnett, R.T.; Jones, L.; Kearney, J.; Franklin, C.A. )

    1994-08-01

    This study was designed to examine differences in the respiratory health status of preadolescent school children, aged 7-11 years, who resided in 10 rural Canadian communities in areas of moderate and low exposure to regional sulfate and ozone pollution. Five of the communities were located in central Saskatchewan, a low-exposure region, and five were located in southwestern Ontario, an area with moderately elevated exposures resulting from long-range atmospheric transport of polluted air masses. In this cross-sectional study, the child's respiratory symptoms and illness history were evaluated using a parent-completed questionnaire, administered in September 1985. Respiratory function was assessed once for each child in the schools between October 1985 and March 1986, by the measurement of pulmonary function for forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV[sub 1.0]), peak expiratory flow rate (PEFR), mean forced expiratory flow rate during the middle half of the FVC curve (FEF[sub 25-75]), and maximal expiratory flow at 50% of the expired vital capacity (V[sub 50]max). After controlling for the effects of age, sex, parental smoking, parental education and gas cooking, no significant regional differences were observed in rates of chronic cough or phlegm, persistent wheeze, current asthma, bronchitis in the past year, or any chest illness that kept the child at home for 3 or more consecutive days during the previous year. Children living in southwestern Ontario had statistically significant (P < 0.01) mean decrements of 1.7% in FVC and 1.3% in FEV[sub 1.0] compared with Saskatchewan children, after adjusting for age, sex, weight, standing height, parental smoking, and gas cooking. There were no statistically significant regional differences in the pulmonary flow parameters (P > 0.05). 54 refs., 1 fig., 7 tabs.

  12. Effect of low doses of lipopolysaccharide prior to ozone exposure on bronchoalveolar lavage

    PubMed Central

    Haque, Rizwanul; Umstead, Todd M.; Ahn, Kwangmi; Phelps, David S.; Floros, Joanna

    2010-01-01

    SUMMARY Background Several aspects of the inflammatory response to a single insult, i.e., exposure to 2 ppm of ozone (O3) for 3 h or 6 h, are less pronounced in surfactant protein A deficient (SP-A −/−) mice (KO) than in wild type mice (WT). It was hypothesized that a mild insult, specifically low doses of lipopolysaccharide (LPS), would adversely affect host defense and differentially potentiate O3-induced injury in WT and KO mice. METHODS WT and KO mice were treated with different doses of LPS or LPS (2 ng) + O3 (2 ppm) or filtered air (FA) for 3 h, then sacrificed 4 h following exposure (O3, FA) or 20 h after LPS treatment alone. Several endpoints of inflammation were measured in bronchoalveolar lavage (BAL). RESULTS 1) At 20 h after LPS treatment alone, both WT and KO mice exhibited signs of inflammation, but with differences in the macrophage inflammatory protein 2 (MIP-2) response pattern, total cells (at 0.5 ng LPS) and basal levels of oxidized protein and phospholipids; 2) After LPS + O3, KO compared to WT showed decrease in polymorphonuclear leukocytes (PMNs) and MIP-2 and increase in phospholipids, and after LPS + FA an increase in total cells; 3) WT after LPS + FA showed an increase in SP-A with no further increase after LPS + O3, and an increase in oxidized SP-A dimer following O3 or LPS + O3. CONCLUSIONS LPS treatment has negative effects on inflammation endpoints in mouse BAL long after exposure and renders KO mice less capable of responding to a second insult. LPS and O3 affect SP-A, quantitatively and qualitatively, respectively. PMID:21278811

  13. Inflammatory Cytokines and White Blood Cell Counts Response to Environmental Levels of Diesel Exhaust and Ozone Inhalation Exposures

    PubMed Central

    Stiegel, Matthew A.; Pleil, Joachim D.; Sobus, Jon R.; Madden, Michael C.

    2016-01-01

    Epidemiological observations of urban inhalation exposures to diesel exhaust (DE) and ozone (O3) have shown pre-clinical cardiopulmonary responses in humans. Identifying the key biological mechanisms that initiate these health bioindicators is difficult due to variability in environmental exposure in time and from person to person. Previously, environmentally controlled human exposure chambers have been used to study DE and O3 dose-response patterns separately, but investigation of co-exposures has not been performed under controlled conditions. Because a mixture is a more realistic exposure scenario for the general public, in this study we investigate the relationships of urban levels of urban-level DE exposure (300 μg/m3), O3 (0.3 ppm), DE + O3 co-exposure, and innate immune system responses. Fifteen healthy human volunteers were studied for changes in ten inflammatory cytokines (interleukins 1β, 2, 4, 5, 8, 10, 12p70 and 13, IFN-γ, and TNF-α) and counts of three white blood cell types (lymphocytes, monocytes, and neutrophils) following controlled exposures to DE, O3, and DE+O3. The results show subtle cytokines responses to the diesel-only and ozone-only exposures, and that a more complex (possibly synergistic) relationship exists in the combination of these two exposures with suppression of IL-5, IL-12p70, IFN-γ, and TNF-α that persists up to 22-hours for IFN-γ and TNF-α. The white blood cell differential counts showed significant monocyte and lymphocyte decreases and neutrophil increases following the DE + O3 exposure; lymphocytes and neutrophils changes also persist for at least 22-hours. Because human studies must be conducted under strict safety protocols at environmental levels, these effects are subtle and are generally only seen with detailed statistical analysis. This study indicates that the observed associations between environmental exposures and cardiopulmonary effects are possibly mediated by inflammatory response mechanisms. PMID:27058360

  14. Inflammatory Cytokines and White Blood Cell Counts Response to Environmental Levels of Diesel Exhaust and Ozone Inhalation Exposures.

    PubMed

    Stiegel, Matthew A; Pleil, Joachim D; Sobus, Jon R; Madden, Michael C

    2016-01-01

    Epidemiological observations of urban inhalation exposures to diesel exhaust (DE) and ozone (O3) have shown pre-clinical cardiopulmonary responses in humans. Identifying the key biological mechanisms that initiate these health bioindicators is difficult due to variability in environmental exposure in time and from person to person. Previously, environmentally controlled human exposure chambers have been used to study DE and O3 dose-response patterns separately, but investigation of co-exposures has not been performed under controlled conditions. Because a mixture is a more realistic exposure scenario for the general public, in this study we investigate the relationships of urban levels of urban-level DE exposure (300 μg/m3), O3 (0.3 ppm), DE + O3 co-exposure, and innate immune system responses. Fifteen healthy human volunteers were studied for changes in ten inflammatory cytokines (interleukins 1β, 2, 4, 5, 8, 10, 12p70 and 13, IFN-γ, and TNF-α) and counts of three white blood cell types (lymphocytes, monocytes, and neutrophils) following controlled exposures to DE, O3, and DE+O3. The results show subtle cytokines responses to the diesel-only and ozone-only exposures, and that a more complex (possibly synergistic) relationship exists in the combination of these two exposures with suppression of IL-5, IL-12p70, IFN-γ, and TNF-α that persists up to 22-hours for IFN-γ and TNF-α. The white blood cell differential counts showed significant monocyte and lymphocyte decreases and neutrophil increases following the DE + O3 exposure; lymphocytes and neutrophils changes also persist for at least 22-hours. Because human studies must be conducted under strict safety protocols at environmental levels, these effects are subtle and are generally only seen with detailed statistical analysis. This study indicates that the observed associations between environmental exposures and cardiopulmonary effects are possibly mediated by inflammatory response mechanisms. PMID:27058360

  15. Multi-route trihalomethane exposure in households using municipal tap water treated with chlorine or ozone-chlorine.

    PubMed

    Jo, Wan-Kuen; Kwon, Ki-Dong; Dong, Jong-In; Chung, Yong

    2005-03-01

    In Korea, data for multi-route trihalomethane (THM) exposure in households using municipal tap water treated with ozone-chlorine or chlorine are unavailable or very limited. Accordingly, the present study was designed to obtain those data by measurements of the THM concentrations in the tap water and indoor and outdoor air in the two types of households, along with an estimation of THM exposure from water ingestion, showering, and the inhalation of indoor air. Chloroform was the most abundant THM in all three media, yet no bromoform was detected in any sample. Similar to previous findings, the winter chloroform concentration in tap water treated with chlorine (22.1 microg/l, median) was significantly higher than that in the tap water treated with ozone-chlorine (16.8 microg/l, median). However, the summer water chloroform concentrations and summer and winter water concentrations of the other two THMs (bromodichloromethane and dibromochloromethane) exhibited no significant difference between the chlorine and ozone-chlorine-treated water. It was suggested that the effects of the water parameters including biochemical oxygen demand of raw water entering water treatment plants should be considered when evaluating the advantage of ozone-chlorine disinfection for THM formation over chlorine disinfection. The indoor air THM concentration trend was also consistent with the water concentration trend. The indoor to outdoor air concentration ratios were comparable with previous studies. The THM exposure estimates from water ingestion, showering, and the inhalation of apartment indoor air when not in the shower suggested that, for residents living in the surveyed households, their exposure to THMs in the home was mostly associated with their household water uses. The THM exposure estimates from tap water ingestion were similar to those from showering. PMID:15740765

  16. Antioxidant activity in mature branches of ponderosa pine (Pinus ponderosa) under long-term, low concentration ozone exposure

    SciTech Connect

    Benes, S.E.; Murphy, T.M.; Laeuchli, A. ); Anderson, P.D.; Houpis, J.L.J. )

    1990-05-01

    Antioxidant activity (superoxide dismutase, peroxidases and glutathione) is being examined in mature needle tissue of ponderosa pine exposed to elevated levels of ozone (O{sub 3}). Trees used in this study are 8-14 year-old clones produced from buds from a 70 year-old tree grafted onto seedling rootstock. Trees are exposed to O{sub 3} using a newly developed branch exposure chamber (BEC). Ozone treatments are charcoal-filtered, ambient and 2x ambient concentrations. A non-chambered branch will determine the effect of exposure chamber. Superoxide dismutase (SOD) activity measured in current-year needles in February via nitrobluetetrazolium (NBT) reduction was 138.5 {plus minus} 15 (SD) units mg{sup {minus}1} protein. The activity of guaiacol-oxidizing peroxidases was 89 {plus minus} 19 (SD) {Delta}A{sub 470} min{sup {minus}1} mg{sup {minus}1} protein. Ascorbate peroxidase and the ratio of oxidized to reduced glutathione (GSSG/GSH) are also being monitored. Antioxidant activity will be measured monthly across the ozone season (March to November) and during natural ozone episodes. Cellular antioxidant activity will be related to needle photosynthesis, respiration and stomatal conductance measured using a Licor 6200 portable photosynthesis apparatus.

  17. Effects of prolonged exposure to low pH on enzymatic and non-enzymatic antioxidants in Japanese Medaka (Oryzias latipes).

    PubMed

    Ramírez-Duarte, Wilson F; Jin, Jiali; Kurobe, Tomofumi; Teh, Swee J

    2016-10-15

    Acidification in aquatic ecosystems is a major concern worldwide. In freshwater, although there are several publications reporting acute toxicity and adverse effects due to low pH, little is known about adverse effects on antioxidant mechanisms in fish after prolonged exposure. This study aimed to investigate how antioxidants are affected by raising larval Japanese Medaka (Oryzias latipes) in soft water at pH5.5, 6.0, and 6.5. After 18days of exposure, glutathione concentration and glutathione peroxidase activity in whole body homogenates increased as pH decreased, without changes in lipid peroxidation measured as thiobarbituric acid reactive substances. This study showed that prolonged exposure to low pH increased reactive oxygen species production and that fish cope with it by increasing levels of enzymatic and non-enzymatic antioxidants. PMID:27285793

  18. Temporal processes that contribute to nonlinearity in vegetation responses to ozone exposure and dose

    NASA Astrophysics Data System (ADS)

    Heath, Robert L.; Lefohn, Allen S.; Musselman, Robert C.

    Ozone interacts with plant tissue through distinct temporal processes. Sequentially, plants are exposed to ambient O 3 that (1) moves through the leaf boundary layer, (2) is taken up into plant tissue primarily through stomata, and (3) undergoes chemical interaction within plant tissue, first by initiating alterations and then as part of plant detoxification and repair. In this paper, we discuss the linkage of the temporal variability of apoplastic ascorbate with the diurnal variability of defense mechanisms in plants and compare this variability with daily maximum O 3 concentration and diurnal uptake and entry of O 3 into the plant through stomata. We describe the quantitative evidence on temporal variability in concentration and uptake and find that the time incidence for maximum defense does not necessarily match diurnal patterns for maximum O 3 concentration or maximum uptake. We suggest that the observed out-of-phase association of the diurnal patterns for the above three processes produces a nonlinear relationship that results in a greater response from the higher hourly average O 3 concentrations than from the lower or mid-level values. The fact that these out-of-phase processes affect the relationship between O 3 exposure/dose and vegetation effects ultimately impact the ability of flux-based indices to predict vegetation effects accurately for purposes of standard setting and critical levels. Based on the quantitative aspect of temporal variability identified in this paper, we suggest that the inclusion of a diurnal pattern for detoxification in effective flux-based models would improve the predictive characteristics of the models. While much of the current information has been obtained using high O 3 exposures, future research results derived from laboratory biochemical experiments that use short but elevated O 3 exposures should be combined with experimental results that use ambient-type exposures over longer periods of time. It is anticipated that

  19. Effects of acute ozone exposure on the electrophysiological properties of guinea pig trachea

    SciTech Connect

    Croxton, T.L.; Takahashi, Masahiko; Kokia, Ira

    1994-12-31

    Acute ozone (O{sub 3}) exposures produce an increase in the apparent permeability of the tracheal epithelium, but the mechanism of this response is poorly understood. Comparison of previous studies suggests that qualitative differences may exist between measurements made in vivo or in vitro. To test this possibility we used both in vitro and in vivo electrophysiological techniques to investigate the effects of O{sub 3} exposure on guinea pig tracheal epithelium. Male Hartley guinea pigs were exposed to either 1 or 2 ppm O{sub 3} or to filtered air for 3 h and were studied 0, 6, or 24 h after exposure. Air-exposed animals had in vitro mean tracheal potential (V{sub T}) -32.0 {+-} 1.5 mV, conductance (G{sub T}{sup L}) 2.18 {+-} 0.22 mS/cm, short-circuit current (I{sub SC}{sup L}) 62.6 {+-} 3.7 {mu}A/cm, and diameter (D) 2.44 {+-} 0.10 mm. In vitro properties after 1 ppm O{sub 3} exposure did not differ at any time point from control. Two parts per million O{sub 3} increased I{sub SC}{sup L}, but only at 6 h postexposure. The effect of O{sub 3} on I{sub SC}{sup L} was abolished by amiloride. There were no significant changes in V{sub T}, G{sub T}{sup L}, or D. In vivo tracheal potential under pentobarbital anesthesia was -19.7 {+-} 1.7 mV. At 6 h postexposure to 2 ppm O{sub 3}, but not at 0 or 24 h, in vivo V{sub I} was increased. Thus, acute exposure of guinea pigs to a high concentration of O{sub 3} caused a delayed increase in Na{sup +} absorption by the trachea with no change in conductance. This indicates that paracellular permeability of guinea pig tracheal epithelium was not substantially increased by acute O{sub 3} and suggests that enhanced macromolecular uptake in this species probably occurs transcellularly. 24 refs., 1 fig., 2 tabs.

  20. Treating posttraumatic stress disorder with MDMA-assisted psychotherapy: A preliminary meta-analysis and comparison to prolonged exposure therapy.

    PubMed

    Amoroso, Timothy; Workman, Michael

    2016-07-01

    Since the wars in Iraq and Afghanistan, posttraumatic stress disorder (PTSD) has become a major area of research and development. The most widely accepted treatment for PTSD is prolonged exposure (PE) therapy, but for many patients it is intolerable or ineffective. ±3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy (MDMA-AP) has recently re-emerged as a new treatment option, with two clinical trials having been published and both producing promising results. However, these results have yet to be compared to existing treatments. The present paper seeks to bridge this gap in the literature. Often the statistical significance of clinical trials is overemphasized, while the magnitude of the treatment effects is overlooked. The current meta-analysis aims to provide a comparison of the cumulative effect size of the MDMA-AP studies with those of PE. Effect sizes were calculated for primary and secondary outcome measures in the MDMA-AP clinical trials and compared to those of a meta-analysis including several PE clinical trials. It was found that MDMA-AP had larger effect sizes in both clinician-observed outcomes than PE did (Hedges' g=1.17 vs. g=1.08, respectively) and patient self-report outcomes (Hedges' g=0.87 vs. g=0.77, respectively). The dropout rates of PE and MDMA-AP were also compared, revealing that MDMA-AP had a considerably lower percentage of patients dropping out than PE did. These results suggest that MDMA-AP offers a promising treatment for PTSD. PMID:27118529

  1. Influence of tropospheric ozone control on exposure to ultraviolet radiation at the surface.

    PubMed

    Madronich, Sasha; Wagner, Mark; Groth, Philip

    2011-08-15

    Improving air quality by reducing ambient ozone (O(3)) will likely lower O(3) concentrations throughout the troposphere and increase the transmission of solar ultraviolet (UV) radiation to the surface. The changes in surface UV radiation between two control scenarios (nominally 84 and 70 ppb O(3) for summer 2020) in the Eastern two-thirds of the contiguous U.S. are estimated, using tropospheric O(3) profiles calculated with a chemistry-transport model (Community Multi-Scale Air Quality, CMAQ) as inputs to a detailed model of the transfer of solar radiation through the atmosphere (tropospheric ultraviolet-visible, TUV) for clear skies, weighed for the wavelengths known to induce sunburn and skin cancer. Because the incremental emission controls differ according to region, strong spatial variability in O(3) reductions and in corresponding UV radiation increments is seen. The geographically averaged UV increase is 0.11 ± 0.03%, whereas the population-weighted increase is larger, 0.19 ± 0.06%, because O(3) reductions are greater in more densely populated regions. These relative increments in exposure are non-negligible given the already high incidence of UV-related health effects, but are lower by an order of magnitude or more than previous estimates. PMID:21755973

  2. Protein Cross-Linking and Oligomerization through Dityrosine Formation upon Exposure to Ozone.

    PubMed

    Kampf, Christopher J; Liu, Fobang; Reinmuth-Selzle, Kathrin; Berkemeier, Thomas; Meusel, Hannah; Shiraiwa, Manabu; Pöschl, Ulrich

    2015-09-15

    Air pollution is a potential driver for the increasing prevalence of allergic disease, and post-translational modification by air pollutants can enhance the allergenic potential of proteins. Here, the kinetics and mechanism of protein oligomerization upon ozone (O3) exposure were studied in coated-wall flow tube experiments at environmentally relevant O3 concentrations, relative humidities and protein phase states (amorphous solid, semisolid, and liquid). We observed the formation of protein dimers, trimers, and higher oligomers, and attribute the cross-linking to the formation of covalent intermolecular dityrosine species. The oligomerization proceeds fast on the surface of protein films. In the bulk material, reaction rates are limited by diffusion depending on phase state and humidity. From the experimental data, we derive a chemical mechanism and rate equations for a kinetic multilayer model of surface and bulk reaction enabling the prediction of oligomer formation. Increasing levels of tropospheric O3 in the Anthropocene may promote the formation of protein oligomers with enhanced allergenicity and may thus contribute to the increasing prevalence of allergies. PMID:26287571

  3. The effects of sequential exposure to acidic fog and ozone on pulmonary function in exercising subjects

    SciTech Connect

    Aris, R.; Christian, D.; Sheppard, D.; Balmes, J.R. )

    1991-01-01

    In Southern California coastal regions, morning fog is often acidified by the presence of nitric acid (HNO{sub 3}). Peak exposure to ozone (O{sub 3}) usually occurs in the afternoon and evening, after the fog has dissipated. To determine whether fog containing HNO{sub 3} might enhance pulmonary responses to O{sub 3}, we studied a group of healthy, athletic subjects selected for lung function sensitivity to O{sub 3}. On 3 separate days, the subjects exercised for 2 h in atmospheres containing HNO{sub 3} fog (0.5 mg/ml), H{sub 2}O fog, or clean, filtered air. After a 1-h break, they exercised for an additional 3 h in an atmosphere containing 0.20 ppm O{sub 3}. Surprisingly, the mean O{sub 3}-induced decrements in FEV1 and FVC were smaller after exercise in each fog-containing atmosphere than they were after exercise in clean, filtered air. The mean (+/- SEM) O{sub 3}-induced decrements in FEV1 were 26.4 +/- 5.3% after air, 17.1 +/- 3.7% after H{sub 2}O fog, and 18.0 +/- 4.3% after HNO{sub 3} fog, and in FVC they were 19.9 +/- 4.7% after air, 13.6 +/- 2.8% after H{sub 2}O fog, and 13.6 +/- 4.2% after HNO{sub 3} fog.

  4. Assessment of rice yield loss due to exposure to ozone pollution in Southern Vietnam.

    PubMed

    Danh, Ngo Thanh; Huy, Lai Nguyen; Oanh, Nguyen Thi Kim

    2016-10-01

    The study domain covered the Eastern region of Southern of Vietnam that includes Ho Chi Minh City (HCMC) and five other provinces. Rice production in the domain accounted for 13% of the national total with three crop cycles per year. We assessed ozone (O3) induced rice production loss in the domain for 2010 using simulated hourly surface O3 concentrations (WRF/CAMx; 4km resolution). Simulated O3 was higher in January-February (largely overlaps the first crop) and September-December (third crop), and lower in March-June (second crop). Spatially, O3 was higher in downwind locations of HCMC and were comparable with observed data. Relative yield loss (RYL) was assessed for each crop over the respective growing period (105days) using three metrics: AOT40, M7 and flux-based O3 dose of POD10. Higher RYL was estimated for the downwind of HCMC. Overall, the rice production loss due to O3 exposure in the study domain in 2010 was the highest for the first crop (up to 25,800metrictons), the second highest for the third crop (up to 21,500tons) and the least for the second crop (up to 6800tons). The low RYL obtained for the second crop by POD10 may be due to the use of a high threshold value (Y=10nmolm(-2)s(-1)). Linear regression between non-null radiation POD0 and POD10 had similar slopes for the first and third crop when POD0 was higher and very low slope for the second crop when POD0 was low. The results of this study can be used for the rice crop planning to avoid the period of potential high RYL due to O3 exposure. PMID:27265741

  5. Effect of cumulative ozone exposure on ozone-induced nasal epithelial hyperplasia and secretory metaplasia in rats

    SciTech Connect

    Hotchkiss, J.A.; Harkema, J.R.; Henderson, R.F. )

    1991-05-01

    Repeated exposure of rats to O3 induces proliferative and secretory metaplastic changes within nasal airway epithelia that may protect against subsequent exposures. Our study assessed the effect of different cumulative exposure times on O3-induced nasal epithelial hyperplasia and secretory metaplasia. Rats were exposed 6 h/day to air or to 0.8 ppm O3 and were sacrificed 18 h after the end of their last exposure. The rats were exposed to either air or 0.8 ppm O3 for 3 or 7 days, or to 0.8 ppm O3 for 3 days followed by a 4-day exposure to air. The effects of the exposures were determined by quantitating the hyperplastic (epithelial nuclei/mm basal lamina) and secretory metaplastic changes (volume densities of acidic and neutral mucosubstances) within the nasal nonciliated cuboidal epithelium (NNCE). There were no significant changes in NNCE cell numeric density, or in the volume density of intraepithelial mucus, compared to air-exposed control rats, in rats exposed to O3 for 3 days and sacrificed 18 h later. Compared to control rats, there was significant epithelial hyperplasia and secretory metaplasia within the NNCE of rats exposed to O3 either for 7 days or for 3 days followed by 4 days of exposure to air. There were no significant differences in NNCE cell hyperplasia or secretory metaplasia between these two experimental groups. Three 6 h/day exposures to 0.8 ppm O3 triggered hyperplastic and metaplastic changes within rat NNCE that were indistinguishable from those produced by seven 6 h/day exposures to the same concentration of O3. The data suggest that O3 is capable of rapidly inducing hyperplastic and metaplastic responses within rat NNCE, and that once initiated, development of the phenotypic changes within the epithelium does not require further O3 exposure.

  6. RNA-seq analysis reveals genetic response and tolerance mechanisms to ozone exposure in soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oxidative stress caused by ground level ozone is a major contributor to yield loss in a number of important crop plants. Soybean (Glycine max) is especially ozone sensitive, and research into its response to oxidative stress is limited. To better understand the genetic response in soybean to oxida...

  7. USE OF PERSONAL MEASUREMENTS FOR OZONE EXPOSURE ASSESSMENT: A PILOT STUDY

    EPA Science Inventory

    During summer 1991, we collected indoor, outdoor, and personal ozone concentration data as well as time-activity data in state College, Pennsylvania. hese concentrations were measured for 23 children and their homes using passive ozone samplers. outdoor concentrations were also m...

  8. Persistent rhinitis and epithelial remodeling induced by cyclic ozone exposure in the nasal airways of infant monkeys

    PubMed Central

    Ballinger, Carol A.; Plopper, Charles G.; McDonald, Ruth J.; Bartolucci, Alfred A.; Postlethwait, Edward M.; Harkema, Jack R.

    2011-01-01

    Children chronically exposed to high levels of ozone (O3), the principal oxidant pollutant in photochemical smog, are more vulnerable to respiratory illness and infections. The specific factors underlying this differential susceptibility are unknown but may be related to air pollutant-induced nasal alterations during postnatal development that impair the normal physiological functions (e.g., filtration and mucociliary clearance) serving to protect the more distal airways from inhaled xenobiotics. In adult animal models, chronic ozone exposure is associated with adaptations leading to a decrease in airway injury. The purpose of our study was to determine whether cyclic ozone exposure induces persistent morphological and biochemical effects on the developing nasal airways of infant monkeys early in life. Infant (180-day-old) rhesus macaques were exposed to 5 consecutive days of O3 [0.5 parts per million (ppm), 8 h/day; “1-cycle”] or filtered air (FA) or 11 biweekly cycles of O3 (FA days 1–9; 0.5 ppm, 8 h/day on days 10–14; “11-cycle”). The left nasal passage was processed for light microscopy and morphometric analysis. Mucosal samples from the right nasal passage were processed for GSH, GSSG, ascorbate (AH2), and uric acid (UA) concentration. Eleven-cycle O3 induced persistent rhinitis, squamous metaplasia, and epithelial hyperplasia in the anterior nasal airways of infant monkeys, resulting in a 39% increase in the numeric density of epithelial cells. Eleven-cycle O3 also induced a 65% increase in GSH concentrations at this site. The persistence of epithelial hyperplasia was positively correlated with changes in GSH. These results indicate that early life ozone exposure causes persistent nasal epithelial alterations in infant monkeys and provide a potential mechanism for the increased susceptibility to respiratory illness exhibited by children in polluted environments. PMID:21131400

  9. Persistent rhinitis and epithelial remodeling induced by cyclic ozone exposure in the nasal airways of infant monkeys.

    PubMed

    Carey, Stephan A; Ballinger, Carol A; Plopper, Charles G; McDonald, Ruth J; Bartolucci, Alfred A; Postlethwait, Edward M; Harkema, Jack R

    2011-02-01

    Children chronically exposed to high levels of ozone (O(3)), the principal oxidant pollutant in photochemical smog, are more vulnerable to respiratory illness and infections. The specific factors underlying this differential susceptibility are unknown but may be related to air pollutant-induced nasal alterations during postnatal development that impair the normal physiological functions (e.g., filtration and mucociliary clearance) serving to protect the more distal airways from inhaled xenobiotics. In adult animal models, chronic ozone exposure is associated with adaptations leading to a decrease in airway injury. The purpose of our study was to determine whether cyclic ozone exposure induces persistent morphological and biochemical effects on the developing nasal airways of infant monkeys early in life. Infant (180-day-old) rhesus macaques were exposed to 5 consecutive days of O(3) [0.5 parts per million (ppm), 8 h/day; "1-cycle"] or filtered air (FA) or 11 biweekly cycles of O(3) (FA days 1-9; 0.5 ppm, 8 h/day on days 10-14; "11-cycle"). The left nasal passage was processed for light microscopy and morphometric analysis. Mucosal samples from the right nasal passage were processed for GSH, GSSG, ascorbate (AH(2)), and uric acid (UA) concentration. Eleven-cycle O(3) induced persistent rhinitis, squamous metaplasia, and epithelial hyperplasia in the anterior nasal airways of infant monkeys, resulting in a 39% increase in the numeric density of epithelial cells. Eleven-cycle O(3) also induced a 65% increase in GSH concentrations at this site. The persistence of epithelial hyperplasia was positively correlated with changes in GSH. These results indicate that early life ozone exposure causes persistent nasal epithelial alterations in infant monkeys and provide a potential mechanism for the increased susceptibility to respiratory illness exhibited by children in polluted environments. PMID:21131400

  10. Long-term exposure to ambient ozone and mortality: a quantitative systematic review and meta-analysis of evidence from cohort studies

    PubMed Central

    Atkinson, R W; Butland, B K; Dimitroulopoulou, C; Heal, M R; Stedman, J R; Carslaw, N; Jarvis, D; Heaviside, C; Vardoulakis, S; Walton, H; Anderson, H R

    2016-01-01

    Objectives While there is good evidence for associations between short-term exposure to ozone and a range of adverse health outcomes, the evidence from narrative reviews for long-term exposure is suggestive of associations with respiratory mortality only. We conducted a systematic, quantitative evaluation of the evidence from cohort studies, reporting associations between long-term exposure to ozone and mortality. Methods Cohort studies published in peer-reviewed journals indexed in EMBASE and MEDLINE to September 2015 and PubMed to October 2015 and cited in reviews/key publications were identified via search strings using terms relating to study design, pollutant and health outcome. Study details and estimate information were extracted and used to calculate standardised effect estimates expressed as HRs per 10 ppb increment in long-term ozone concentrations. Results 14 publications from 8 cohorts presented results for ozone and all-cause and cause-specific mortality. We found no evidence of associations between long-term annual O3 concentrations and the risk of death from all causes, cardiovascular or respiratory diseases, or lung cancer. 4 cohorts assessed ozone concentrations measured during the warm season. Summary HRs for cardiovascular and respiratory causes of death derived from 3 cohorts were 1.01 (95% CI 1.00 to 1.02) and 1.03 (95% CI 1.01 to 1.05) per 10 ppb, respectively. Conclusions Our quantitative review revealed a paucity of independent studies regarding the associations between long-term exposure to ozone and mortality. The potential impact of climate change and increasing anthropogenic emissions of ozone precursors on ozone levels worldwide suggests further studies of the long-term effects of exposure to high ozone levels are warranted. PMID:26908518

  11. Ozone and allergen exposure during postnatal development alters the frequency and airway distribution of CD25+ cells in infant rhesus monkeys

    SciTech Connect

    Miller, Lisa A. Gerriets, Joan E.; Tyler, Nancy K.; Abel, Kristina; Schelegle, Edward S.; Plopper, Charles G.; Hyde, Dallas M.

    2009-04-01

    The epidemiologic link between air pollutant exposure and asthma has been supported by experimental findings, but the mechanisms are not understood. In this study, we evaluated the impact of combined ozone and house dust mite (HDM) exposure on the immunophenotype of peripheral blood and airway lymphocytes from rhesus macaque monkeys during the postnatal period of development. Starting at 30 days of age, monkeys were exposed to 11 cycles of filtered air, ozone, HDM aerosol, or ozone + HDM aerosol. Each cycle consisted of ozone delivered at 0.5 ppm for 5 days (8 h/day), followed by 9 days of filtered air; animals received HDM aerosol during the last 3 days of each ozone exposure period. Between 2-3 months of age, animals co-exposed to ozone + HDM exhibited a decline in total circulating leukocyte numbers and increased total circulating lymphocyte frequency. At 3 months of age, blood CD4+/CD25+ lymphocytes were increased with ozone + HDM. At 6 months of age, CD4+/CD25+ and CD8+/CD25+ lymphocyte populations increased in both blood and lavage of ozone + HDM animals. Overall volume of CD25+ cells within airway mucosa increased with HDM exposure. Ozone did not have an additive effect on volume of mucosal CD25+ cells in HDM-exposed animals, but did alter the anatomical distribution of this cell type throughout the proximal and distal airways. We conclude that a window of postnatal development is sensitive to air pollutant and allergen exposure, resulting in immunomodulation of peripheral blood and airway lymphocyte frequency and trafficking.

  12. Influence of age on the biochemical response of rat lung to ozone exposure

    SciTech Connect

    Mustafa, M.G.; Elsayed, N.M.; Ospital, J.J.; Hacker, A.D.

    1985-11-01

    We have previously examined the influence of animal age on the pulmonary response to ozone (O3) in rats between 7 and 90 days of age. In the present study, we expanded the age groups of rats, and examined in greater detail the relationship between animal age and pulmonary response to inhaled O3. We exposed 7 groups of specific pathogen free, male Sprague-Dawley rats, aged 24, 30, 45, 60, 90, 180, and 365 days, to 0.8 ppm (1568 micrograms/m3) O3 continuously for 3 days. After O3 exposure, we sacrificed the exposed rats and a matched number of controls from each age group, and analyzed their lungs for a series of physical and biochemical parameters, including glutathione metabolizing and NADPH producing enzyme activities. We observed that in control rats all the parameters increased as a function of age. However, the rate of increase was generally slower after age 60 days. After O3 exposure there was an increase in all the parameters for all age groups relative to their corresponding controls, but the extent of increase was significantly larger in rats 60 days and older than in younger rats. A regression of the difference in mean values between control and exposed animals for each parameter against age showed a linear correlation, indicating that the response was age-dependent. Since the magnitude of such increases is thought to reflect the degree of lung injury, the results suggest that O3 exposure causes greater lung injury in older rats than in younger rats. We tested this assumption by exposing rats from four different age groups (24, 45, 60 and 90 days) to a lethal dose of O3 (4 ppm or 7840 micrograms/m3 for 8 hours). The mortality rates were 50% and 83% for 24 and 45 day old rats, respectively, and 100% for 60 and 90 day old rats. The results of these studies further demonstrate that older rats are more susceptible to lung injury from O3 than younger rats.

  13. Exposure information in environmental health research: Current opportunities and future directions for particulate matter, ozone, and toxic air pollutants

    SciTech Connect

    McKone, Thomas E.; Ryan, P. Barry; Ozkaynak, Haluk

    2007-02-01

    Understanding and quantifying outdoor and indoor sources of human exposure are essential but often not adequately addressed in health-effects studies for air pollution. Air pollution epidemiology, risk assessment, health tracking and accountability assessments are examples of health-effects studies that require but often lack adequate exposure information. Recent advances in exposure modeling along with better information on time-activity and exposure factors data provide us with unique opportunities to improve the assignment of exposures for both future and ongoing studies linking air pollution to health impacts. In September 2006, scientists from the US Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) along with scientists from the academic community and state health departments convened a symposium on air pollution exposure and health in order to identify, evaluate, and improve current approaches for linking air pollution exposures to disease. This manuscript presents the key issues, challenges and recommendations identified by the exposure working group, who used cases studies of particulate matter, ozone, and toxic air pollutant exposure to evaluate health-effects for air pollution. One of the over-arching lessons of this workshop is that obtaining better exposure information for these different health-effects studies requires both goal-setting for what is needed and mapping out the transition pathway from current capabilities to meeting these goals. Meeting our long-term goals requires definition of incremental steps that provide useful information for the interim and move us toward our long-term goals. Another over-arching theme among the three different pollutants and the different health study approaches is the need for integration among alternate exposure assessment approaches. For example, different groups may advocate exposure indicators, biomonitoring, mapping methods (GIS), modeling, environmental media

  14. Projected Carbon Dioxide to Increase Grass Pollen and Allergen Exposure Despite Higher Ozone Levels

    PubMed Central

    Albertine, Jennifer M.; Manning, William J.; DaCosta, Michelle; Stinson, Kristina A.; Muilenberg, Michael L.; Rogers, Christine A.

    2014-01-01

    One expected effect of climate change on human health is increasing allergic and asthmatic symptoms through changes in pollen biology. Allergic diseases have a large impact on human health globally, with 10–30% of the population affected by allergic rhinitis and more than 300 million affected by asthma. Pollen from grass species, which are highly allergenic and occur worldwide, elicits allergic responses in 20% of the general population and 40% of atopic individuals. Here we examine the effects of elevated levels of two greenhouse gases, carbon dioxide (CO2), a growth and reproductive stimulator of plants, and ozone (O3), a repressor, on pollen and allergen production in Timothy grass (Phleum pratense L.). We conducted a fully factorial experiment in which plants were grown at ambient and/or elevated levels of O3 and CO2, to simulate present and projected levels of both gases and their potential interactive effects. We captured and counted pollen from flowers in each treatment and assayed for concentrations of the allergen protein, Phl p 5. We found that elevated levels of CO2 increased the amount of grass pollen produced by ∼50% per flower, regardless of O3 levels. Elevated O3 significantly reduced the Phl p 5 content of the pollen but the net effect of rising pollen numbers with elevated CO2 indicate increased allergen exposure under elevated levels of both greenhouse gases. Using quantitative estimates of increased pollen production and number of flowering plants per treatment, we estimated that airborne grass pollen concentrations will increase in the future up to ∼200%. Due to the widespread existence of grasses and the particular importance of P. pratense in eliciting allergic responses, our findings provide evidence for significant impacts on human health worldwide as a result of future climate change. PMID:25372614

  15. Changes in CR-39 proton sensitivity due to prolonged exposure to high vacuums relevant to the National Ignition Facility and OMEGA

    SciTech Connect

    Manuel, M. J.-E.; Rosenberg, M. J.; Sinenian, N.; Rinderknecht, H.; Zylstra, A. B.; Seguin, F. H.; Frenje, J.; Li, C. K.; Petrasso, R. D.

    2011-09-15

    When used at facilities like OMEGA and the NIF, CR-39 is exposed to high vacuum environments before and after irradiation by charged particles and neutrons. Using an electrostatic linear accelerator at MIT, studies have been conducted to investigate the effects of high vacuum exposure on the sensitivity of CR-39 to fusion protons in the {approx}1-9 MeV energy range. High vacuum conditions, of order 10{sup -5} Torr, experienced by CR-39 samples at these facilities were emulated. It is shown that vacuum exposure times longer than {approx}16 h before proton irradiation result in a decrease in proton sensitivity, whereas no effect was observed for up to 67 h of vacuum exposure after proton irradiation. CR-39 sensitivity curves are presented for samples with prolonged exposure to high vacuum before and after proton irradiation.

  16. An Assessment of Forest Pollutant Exposure Using Back Trajectories, Anthropogenic Emissions, and Ambient Ozone and Carbon Monoxide Measurements

    NASA Astrophysics Data System (ADS)

    Carroll, M.; Ocko, I. B.; McNeal, F.; Weremijewicz, J.; Hogg, A. J.; Opoku, N.; Bertman, S. B.; Neil, L.; Fortner, E.; Thornberry, T.; Town, M. S.; Yip, G.; Yageman, L.

    2008-12-01

    Measurements of ozone (O3) and carbon monoxide (CO) have been made above a Mixed Hardwood Forest in northern Michigan as part of the Program for Research on Oxidants: PHotochemistry, Emissions, and Transport (PROPHET) since 1997. Back trajectories calculated using the NOAA HYSPLIT Model have been used to classify air masses reaching the site into five flow regimes named according to the air mass source regions: north and northwesterly; south and southwesterly; westerly; east and southeasterly; and northeasterly. On an annual basis, air masses reaching the site came from the north and northwest, south and southwest, west, and east and southeast 28-35%, 22-25%, 9-14%, and 4 - 5% of the time, respectively. Pollutant levels in these air masses vary significantly with O3 typically 20 - 30 ppbv in north and northwesterly flow and 60 - 100 ppbv in south and southwesterly flow. In order to assess forest pollutant exposure, regional pollutant emissions were analyzed for each of the five flow regimes, the decadal record of ozone measurements were examined for temporal trends, and regression analyses of the O3 and CO data were performed. Nitrogen oxides (NOx), CO, and anthropogenic Volatile Organic Compound (VOC) exposure levels were estimated to be 18.0, 82.0, and 14.0 kg/km2/OSD (Ozone Season Day), respectively, for the south and southwesterly flow regime; 10.2, 57.4, and 9.3 kg/ km2/OSD, respectively, for the east and southeasterly flow regime; 6.9, 29.5, and 5.0 kg/ km2/OSD, respectively, for the westerly flow regime; 0.8, 3.8, and 0.5 kg/km2/OSD, respectively, for the northeasterly flow regime; and 0.4, 1.8, and 0.3 kg/ km2/OSD, respectively, for the north and northwesterly flow regime. In the search for temporal trends, in ambient ozone, arithmetic means and 90th percentiles were examined. A significant decrease is observed in ozone for data obtained during summer (June through August) during the most photochemically active time of day (1300 - 1600 Local Time

  17. Use of human lung tissue for studies of structural changes associated with chronic ozone exposure: Opportunities and critical issues

    SciTech Connect

    Lippmann, M.

    1993-12-01

    Definitive information on the chronic effects of exposure to ozone (O{sub 3}) in humans is not available. There is a strong concern that ozone could produce chronic lung damage in humans on the basis that exposures are ubiquitous at levels that produce transient symptoms, function deficits, and lung inflammation in humans and chronic lung damage in laboratory animals. Both prospective and national population surveys suggest an association between chronic O{sub 3} exposure and reduced lung function, and a pilot investigation of autopsied lungs of accident victims in Los Angeles reported an unexpectedly high incidence of disease in the centriacinar region, the lung region known to receive the highest dose of inhaled O{sub 3}. This paper discusses the advantages and limitations of further studies of structural changes in human lung tissue in relation to chronic O{sub 3} exposure. The major advantages of such studies are that (a) measurable effects may be related to realistic chronic exposures, (b) the effects may be described quantitatively and compared directly to those obtained in chronic animal inhalation exposures, and (c) evidence for chronic effects may be obtained much more rapidly than in prospective studies. The major limitations are the difficulties in obtaining sufficient reliable information on residential history, physical activity out-of-doors, and smoking and other confounding exposures to lung irritants from next of kin, and limited availability of adequate air quality data for determining ambient concentrations at places of residence and/or outdoor exercise. The paper also discusses approaches to minimizing these limitations in the design of specific studies. 15 refs.

  18. Biomarkers of Oxidative Stress Study IV. Are Antioxidants Markers of Ozone Exposure?

    EPA Science Inventory

    To determine whether the oxidative effects of ozone would result in losses of antioxidants from plasma, and possibly bronchoalveolar lavage fluid (BALF). This research is part of a comprehensive, multilaboratory validation study searching for noninvasive biomarkers of oxidative ...

  19. Surface Ozone Effects on Productivity Using a Biogeochemistry Model

    NASA Astrophysics Data System (ADS)

    Felzer, B. S.; Kicklighter, D. W.; Melillo, J. M.; Wang, C.; Zhuang, Q.

    2002-05-01

    The effects of air pollution on vegetation may provide another important control on the carbon cycle that has not yet been widely considered. Prolonged exposure to high levels of ozone, in particular, has been observed to inhibit photosynthesis by direct cellular damage within the leaves. This ozone exposure also indirectly affects photosynthesis, as well as nitrogen uptake and water availability, through changes in stomatal conductance. We have incorporated simple empirical equations derived for hardwoods, conifers, and croplands into the Terrestrial Ecosystem Model (TEM, version 4.2). These equations linearly relate gross primary productivity (GPP) to accumulated hourly ozone levels above a threshold of 40 ppb, such that productivity in regions with high ozone levels is reduced. Indirect effects of ozone have been incorporated by limiting nitrogen uptake, evapotranspiration (which limits further CO2 uptake and increases water availability), and ozone uptake in the month following exposure. Evaluation of TEM with data from a mixed hardwood stand at the Harvard Forest shows a 5% reduction in Net Primary Productivity (NPP) as a result of observed ozone levels. At this site, the most important factor influencing the reduction of NPP in the model is the reduction of N uptake. We also ran TEM with a business-as-usual scenario for ozone during the 21st century, using a 2D atmospheric chemistry model developed at MIT. Results for the U.S. show the largest reduction of NPP throughout the transient simulation occurs in the Northeast and upper Midwest, consistent with the regions of largest ozone exposure. The reduction in carbon accumulation by terrestrial ecosystems from 123 years of ozone exposure is 1.6 Pg C (which constitutes a 10% reduction). While these results are not significant for continental-scale carbon sequestration, they may have important implications for more localized carbon budgets.

  20. Fine Ambient Particulate and Ozone Co-Exposures in Durham, North Carolina: Influence of Season on Particle Chemistry and Cardiovascular Responses in Rats

    EPA Science Inventory

    Epidemiological studies have shown that the presence of one air pollutant modifies the cardiovascular health effects of another while controlled exposure studies in humans have documented synergistic effects of co-exposure to ambient particulate matter (PM) and ozone (O3) on bloo...

  1. Impact of sex and ozone exposure on the course of pneumonia in wild type and SP-A (−/−) mice

    PubMed Central

    Mikerov, Anatoly N.; Hu, Sanmei; Durrani, Faryal; Gan, Xiaozhuang; Wang, Guirong; Umstead, Todd M.; Phelps, David S.; Floros, Joanna

    2012-01-01

    Female mice exhibited higher survival rate than males after pneumonia, with a reversal of this pattern following ozone exposure. Surfactant protein A (SP-A) plays an important role in innate immunity and SP-A (−/−) mice were more susceptible to pneumonia than wild type mice. Here, we investigated underlying mechanisms of the differential susceptibility of mice to pneumonia. Wild type and SP-A (−/−) C57BL/6J male and female mice were exposed to ozone or filtered air (FA) and then infected intratracheally with Klebsiella pneumoniae. Blood, spleen, and lung were analyzed for bacterial counts, lung and spleen weights, and sex hormone and cortisol levels were measured in plasma within two days post-infection. We found: 1) in the absence of ozone-induced oxidative stress, males had higher level of bacterial dissemination compared to females; ozone exposure decreased pulmonary clearance in both sexes and ozone-exposed females were more affected than males; 2) ozone exposure increased lung weight, but decreased spleen weight in both sexes, and in both cases ozone-exposed females were affected the most; 3) plasma cortisol levels in infected mice changed: ozone-exposed > FA-exposed, females > males, and infected > non-infected; 4) no major sex hormone differences were observed in the studied conditions; 5) differences between wild type and SP-A (−/−) mice were observed in some of the studied conditions. We concluded that reduced pulmonary clearance, compromised spleen response to infection, and increased cortisol levels in ozone-exposed females, and the higher level of lung bacterial dissemination in FA-exposed males, contribute to the previously observed survival outcomes. PMID:22285567

  2. Previous exposure to other males leads to prolonged copulation by a predatory true bug (Hemiptera: Heteroptera: Anthocoridae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mating pairs of Anthocoris whitei Reuter (Hemiptera: Heteroptera: Anthocoridae) irregularly exhibit prolonged copulations exceeding 5 hrs in duration. Atypically long copulations may act as a form of post-insemination mate guarding to prevent insemination of a guarded female by other males. In many...

  3. Interaction and Localization of Synthetic Nanoparticles in Healthy and Cystic Fibrosis Airway Epithelial Cells: Effect of Ozone Exposure

    PubMed Central

    Raemy, David O.; Loader, Joan E.; Kailey, Jenai M; Neeves, Keith B.; White, Carl W.; Ahmad, Aftab; Gehr, Peter; Rothen-Rutishauser, Barbara M.

    2012-01-01

    Abstract Background Nanoparticles (NPs) produced by nanotechnology processes have taken the field of medicine by storm. Concerns about safety of these NPs in humans, however, have recently been raised. Although studies of NP toxicity have focused on lung disease the mechanistic link between NP exposure and lung injury remained unclear. This is primarily due to a lack of availability of appropriate airway disease models and sophisticated microscopic techniques to study nano-sized particulate delivery and resulting responses. Methods Air–liquid interface (ALI) cultures of non-cystic fibrosis (CF) and CF airway epithelial cells were exposed to the FITC-labeled NPs using a PennCentury microsprayer™. Uptake of NPs was assessed by FACS. Laser scanning microscopy (LSM) was performed and the images were analyzed by an advanced imaging software to study particle deposition and uptake. Results Flow cytometry data revealed that CF cells accumulated increased amounts of NPs. The increased NP uptake could be attributed to the reduced CF transmembrane conductance regulator (CFTR) function as a similar increased retention/uptake was observed in cells whose CFTR expression was downregulated by antisense oligonucleotide. NPs alone did not induce pro-inflammatory cytokine release or cell death. The cell culture system was sensitive to ozone but exposure to the uncoated synthetic NPs used in this study, did not cause any synergistic or suppressive effects. LSM imaging and subsequent image restoration further indicated particle uptake and intracellular localization. Exposure to ozone increased nuclear uptake in both non-CF and CF cells. Conclusion Our findings demonstrate the uptake of NPs using ALI cultures of non-CF and CF airway epithelial cells. The NPs used here were useful in demonstrating uptake by airway epithelial cells without causing adverse effects in presence or absence of ozone. However, to totally exclude toxic effects, chronic studies under in vivo conditions using

  4. Biomarkers of Oxidative Stress Study V: Ozone exposure of rats and its effect on lipids, proteins and DNA in plasma and urine

    PubMed Central

    Kadiiska, Maria B.; Basu, Samar; Brot, Nathan; Cooper, Christopher; Csallany, A. Saari; Davies, Michael J.; George, Magdalene M.; Murray, Dennis M.; Roberts, L. Jackson; Shigenaga, Mark K.; Sohal, Rajindar S.; Stocker, Roland; Van Thiel, David H.; Wiswedel, Ingrid; Hatch, Gary E.; Mason, Ronald P.

    2014-01-01

    Ozone exposure effect on free radical-catalyzed oxidation products of lipids, proteins and DNA in the plasma and urine of rats was studied as a continuation of the international Biomarker of Oxidative Stress Study (BOSS) sponsored by NIEHS/NIH. The goal was to identify a biomarker for ozone-induced oxidative stress and to assess whether inconsistent results often reported in the literature might be due to the limitations of the available methods for measuring the various types of oxidative products. The time and dose-dependent effects of ozone exposure on rat plasma lipid hydroperoxides, malondialdehyde, F2-isoprostanes, protein carbonyls, methionine oxidation, tyrosine- and phenylalanine oxidation products, as well as urinary malondialdehyde and F2-isoprostanes were investigated with various techniques. The criterion used to recognize a marker in the model of ozone exposure was that a significant effect could be identified and measured in a biological fluid seen at both doses at more than one time point. No statistically significant differences between the experimental and control groups at either ozone dose and time point studied could be identified in this study. Tissue samples were not included. Despite all the work accomplished in the BOSS study of ozone, no available product of oxidation in biological fluid has yet met the required criteria of being a biomarker. The current negative findings as a consequence of ozone exposure are of great importance, because they document that in complex systems, as the present in vivo experiment, the assays used may not provide meaningful data of ozone oxidation, especially in human studies. PMID:23608465

  5. Diesel exhaust but not ozone increases fraction of exhaled nitric oxide in a randomized controlled experimental exposure study of healthy human subjects

    PubMed Central

    2013-01-01

    Background Fraction of exhaled nitric oxide (FENO) is a promising non-invasive index of airway inflammation that may be used to assess respiratory effects of air pollution. We evaluated FENO as a measure of airway inflammation after controlled exposure to diesel exhaust or ozone. Methods Healthy volunteers were exposed to either diesel exhaust (particle concentration 300 μg/m3) and filtered air for one hour, or ozone (300 ppb) and filtered air for 75 minutes. FENO was measured in duplicate at expiratory flow rates of 10, 50, 100 and 270 mL/s before, 6 and 24 hours after each exposure. Results Exposure to diesel exhaust increased FENO at 6 hours compared with air at expiratory flow rates of 10 mL/s (p = 0.01) and at 50 mL/s (p = 0.011), but FENO did not differ significantly at higher flow rates. Increases in FENO following diesel exhaust were attenuated at 24 hours. Ozone did not affect FENO at any flow rate or time point. Conclusions Exposure to diesel exhaust, but not ozone, increased FENO concentrations in healthy subjects. Differences in the induction of airway inflammation may explain divergent responses to diesel exhaust and ozone, with implications for the use of FENO as an index of exposure to air pollution. PMID:23602059

  6. A Time-Stratified Case-Crossover Study of Ambient Ozone Exposure and Emergency Department Visits for Specific Respiratory Diagnoses in California (2005–2008)

    PubMed Central

    Malig, Brian J.; Pearson, Dharshani L.; Chang, Yun Brenda; Broadwin, Rachel; Basu, Rupa; Green, Rochelle S.; Ostro, Bart

    2015-01-01

    Background: Studies have explored ozone’s connection to asthma and total respiratory emergency department visits (EDVs) but have neglected other specific respiratory diagnoses despite hypotheses relating ozone to respiratory infections and allergic responses. Objective: We examined relationships between ozone and EDVs for respiratory visits, including specifically acute respiratory infections (ARI), asthma, pneumonia, chronic obstructive pulmonary disease (COPD), and upper respiratory tract inflammation (URTI). Methods: We conducted a multi-site time-stratified case-crossover study of ozone exposures for approximately 3.7 million respiratory EDVs from 2005 through 2008 among California residents living within 20 km of an ozone monitor. Conditional logistic regression was used to estimate associations by climate zone. Random effects meta-analysis was then applied to estimate pooled excess risks (ER). Effect modification by season, distance from the monitor and individual demographic characteristics (i.e., age, race/ethnicity, sex, and payment method), and confounding by other gaseous air pollutants were also investigated. Meta-regression was utilized to explore how climate zone–level meteorological, demographic, and regional differences influenced estimates. Results: We observed ozone-associated increases in all respiratory, asthma, and ARI visits, which were slightly larger in the warm season [asthma ER per 10-ppb increase in mean of same and previous 3 days ozone exposure (lag03) = 2.7%, 95% CI: 1.5, 3.9; ARI ERlag03 = 1.4%, 95% CI: 0.8, 1.9]. EDVs for pneumonia, COPD, and URTI were also significantly associated with ozone exposure over the whole year, but typically more consistently so during the warm season. Conclusions: Short-term ozone exposures among California residents living near an ozone monitor were positively associated with EDVs for asthma, ARI, pneumonia, COPD, and URTI from 2005 through 2008. Those associations were typically larger and more

  7. Serum biomarkers in young adult and aged Brown Norway (BN) rats following episodic (weekly) ozone exposure

    EPA Science Inventory

    Ozone (03) is an air pollutant that is associated with cardiovascular and respiratory diseases. Older adults are considered to be particularly susceptible to oxidant air pollutants such as 03. Serum biomarkers are being sought that would lead to better predictions of susceptibili...

  8. Glycoalkaloid levels in potato tubers and leaves after intermittent plant exposure to ozone

    SciTech Connect

    Speroni, J.J.; Pell, E.J.; Weissberger, W.C.

    1981-01-01

    Irish potato vines of Norland and Kennebec cultivars were exposed to 387 ..mu..g/m/sup 3/ ozone for 3 hr once every wk throughout their growth. Tubers of Norland and Kennebec were harvested at 120 and 140 days, respectively, from exposed and non-exposed plants. The experiment was conducted in 1977 and again in 1978. Ozone induced severe foliar injury to Norland and slight injury to leaves of Kennebec. Tubers from ozone treated plants displayed a significant reduction (0.35 mg TTGA/100 g fresh weight tuber tissue) in tuber total glycoalkaloids (TTGA) when expressed on a fresh weight basis. However, since differences were not detected for TTGA on a dry-weight basis, the fresh-weight TTGA differences may only reflect variations in moisture content. In a separate experiment, both Norland and Kennebec were exposed to 488 ..mu..g/m/sup 3/ ozone for 3 hr when the plants were 18 days old. When leaves were harvested three days later, no significant differeces were detected between leaf total glycoalkaloid (LTGA) levels of treated and nontreated plants. 26 references, 2 tables.

  9. Provisional assessment of recent studies on health and ecological effects of ozone exposure

    EPA Science Inventory

    A reconsideration of the national ambient air quality standards (NAAQS) for O3 is currently underway. The last Air Quality Criteria Document for Ozone and Related Photochemical Oxidants (O...

  10. SUBCHRONIC EPISODIC EXPOSURE OF RATS TO DIESEL PLUS OZONE INDUCES MINIMAL CARDIOPULMONARY EFFECTS

    EPA Science Inventory

    Diesel exhaust (DE) emissions contribute to near-road air pollution and have been shown to induce a variety of cardiovascular and pulmonary abnormalities in animals and humans. Since high ozone concentrations are often associated with increased traffic-related emissions, we postu...

  11. RESPIRATORY RESPONSES OF VIGOROUSLY EXERCISING CHILDREN TO 0.12 PPM OZONE EXPOSURE

    EPA Science Inventory

    Changes in respiratory function have been suggested for children exposed to less than 0.12 ppm ozone (O3) while engaged in normal activities. Because the results of these studies have been confounded by other variables such as temperature or the presence of other pollutants or ha...

  12. Psychomotor performance during ozone exposure: spectral and discriminant function analysis of EEG

    SciTech Connect

    Gliner, J.A.; Horvath, S.M; Sorich, R.A.; Hanley, J.

    1980-04-01

    Two experiments were conducted to evaluate the effects of ozone on the electroencephalogram during psychomotor performance. The first experiment consisted of a 2-h visual sustained attention task in room air and 0.75 parts per million (ppM) ozone. The second experiment was a divided attention study which combined a visual choice reaction time situation with an auditory sustained attention task. Ozone levels in this experiment were 0.0 ppM, 0.3 ppM, and 0.75 ppM. Spectral and discriminant function analyses were performed on the EEG collected during these studies. Attempts were made to categorize the EEG between different ozone levels, at rest, during each task performance, and between task and no-task performance within each ambient air condition. Discriminations between conditions for individuals were quite good, but discriminations for the combined subjects were disappointing with the exception of those between task and no-task conditions, which were moderately good.

  13. Impact of rising greenhouse gas concentrations on future tropical ozone and UV exposure

    NASA Astrophysics Data System (ADS)

    Meul, Stefanie; Dameris, Martin; Langematz, Ulrike; Abalichin, Janna; Kerschbaumer, Andreas; Kubin, Anne; Oberländer-Hayn, Sophie

    2016-03-01

    Future projections of tropical total column ozone (TCO) are challenging, as its evolution is affected not only by the expected decline of ozone depleting substances but also by the uncertain increase of greenhouse gas (GHG) emissions. To assess the range of tropical TCO projections, we analyze simulations with a chemistry-climate model forced by three different GHG scenarios (Representative Concentration Pathway (RCP) 4.5, RCP6.0, and RCP8.5). We find that tropical TCO will be lower by the end of the 21st century compared to the 1960s in all scenarios with the largest decrease in the medium RCP6.0 scenario. Uncertainties of the projected TCO changes arise from the magnitude of stratospheric column decrease and tropospheric ozone increase which both strongly vary between the scenarios. In the three scenario simulations the stratospheric column decrease is not compensated by the increase in tropospheric ozone. The concomitant increase in harmful ultraviolet irradiance reaches up to 15% in specific regions in the RCP6.0 scenario.

  14. EFFECT OF EXPOSURE TO PAN AND OZONE ON SUSCEPTIBILITY TO CHRONIC BACTERIAL INFECTION

    EPA Science Inventory

    The effects of peroxyacetyl nitrate (PAN) and ozone (O3) on susceptibility of mice and guinea pigs to chronic and acute respiratory infections were studied. The agent used for the acute infectious disease was Streptococcus sp. whereas Mycobacterium tuberculosis served as the agen...

  15. Effects of short- and long-term exposure to ozone on heart rate and blood pressure of emphysematous rats

    SciTech Connect

    Uchiyama, I.; Yokoyama, E.

    1989-02-01

    Electrocardiogram and arterial blood pressure of elastase-treated emphysematous rats (E rats) and saline-treated control rats (S rats) were recorded continuously during exposure to either 1 ppm ozone (O/sub 3/) for 3 hr or 0.5 ppm O/sub 3/ for 6 hr. The heart rates (HRs) of both groups decreased to about 50 and 65% of the initial levels at the end of 1 ppm and 0.5 ppm O/sub 3/ exposure, respectively. Mean arterial blood pressures (MAPs) also decreased to about 76 and 82%, respectively. There was no significant difference in these responses between E and S rats, although the levels of HRs and MAPs of the E rats were always a little lower than those of the S rats. Another group of E and S rats was continuously exposed to 0.2 ppm O/sub 3/ for 4 weeks. The HRs of both E and S groups decreased to about 81 and 88% of the initial levels on the first day, respectively, although they recovered completely by the third day. No significant difference in the variation of HRs during exposure was noted between E and S rats. However, the HR responses of these rats to a challenge exposure of 0.8 ppm O/sub 3/ for 1.5 hr appeared to be different. That is, S rats were more tolerant of the challenge exposure to O/sub 3/ for 1.5 hr than the E rats.

  16. Responses of Fraxinus excelsior L. seedlings to ambient ozone exposure in urban and mountain areas based on physiological characteristics and antioxidant activity.

    PubMed

    Parvanova, Petya; Tzvetkova, Nikolina; Bratanova-Doncheva, Svetla; Chipev, Nesho; Fikova, Radka; Donev, Evgeni

    2013-07-01

    Effects of ozone on the sensitive tree species Fraxinus excelsior L. exposed to ambient air were investigated. The dynamics of photosynthesis, transpiration, stomatal conductance and the activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) in three-year-old ash seedlings were studied during a four-month period (June-September). Seedlings were exposed to ambient ozone in an urban (the Central City Park of Sofia - Borisova Gradina) and a mountain (Plana Mountain) area in Bulgaria. The sites were located near climate monitoring stations, providing data on ozone concentrations and meteorological parameters. Ozone exposure at the mountain site (AOT40) was more than two times higher compared to the urban site. Significantly higher values of sun radiation, transpiration, stomatal conductance and enzyme activity at the mountain site were also observed. At the urban site higher values of temperature and air humidity were registered. Effects of the measured variables on ash seedlings were complex and interdependent. No direct effect of ozone concentration in ambient air on the leaf physiology and biochemistry could be proved. However, intensified SOD and CAT activity in the presence of elevated ozone suggested antioxidant reaction in response to ozone uptake. PMID:23760537

  17. Bronchopulmonary C-fibers' IL1RI contributes to the prolonged apneic response to intra-atrial injection of capsaicin by prenatal nicotinic exposure in rat pups.

    PubMed

    Zhao, Lei; Zhuang, Jianguo; Xu, Fadi

    2016-07-15

    Prenatal nicotinic exposure (PNE) as a SIDS model reportedly sensitizes bronchopulmonary C-fibers (PCFs), contributing to the prolonged PCF-mediated apnea in rat pups, but the relevant mechanisms are not fully understood. Pulmonary IL-1β upregulated by cigarette smoke is known to stimulate or sensitize PCFs acting via IL-1 type I receptor (IL1RI) and inhibit inspiration frequency. Because of its upregulation observed in SIDS victims, we hypothesized that PNE increased pulmonary IL-1β release and IL1RI expression in pulmonary C-neurons via action on α7 nicotinic acetylcholine receptors (α7nAChR) to induce the prolonged PCF-mediated apnea. IL-1β in BALF and IL1RI in the nodose/jugular (N/J) ganglion and vagal pulmonary C-neurons retrogradely-traced were compared between Ctrl (saline) and PNE pups and among the vehicle-treated Ctrl and PNE and methyllycaconitine (a selective α7nAChR antagonist)-treated PNE pups. The effect of IL-1RI blockade (IL-1Ra) on the PCF-mediated apnea was also compared between Ctrl and PNE pups. PNE significantly elevated IL-1β in BALF and upregulated IL1RI gene and protein expression in N/J ganglia and gene in vagal pulmonary C-neurons. All of these responses were eliminated by pretreatment with blockade of α7nAChR. In addition, the prolonged PCF-mediated apnea in PNE pups was significantly shortened by right atrial bolus injection of IL-1Ra. We conclude that PNE enhances pulmonary IL-1β release and PCF IL1RI expression acting via α7nAChR in contributing to sensitization of PCFs and prolongation of the PCF-mediated apneic response. PMID:27180639

  18. Bioindicators and reproductive effects of prolonged 17beta-oestradiol exposure in a marine fish, the sand goby (Pomatoschistus minutus).

    PubMed

    Robinson, Craig D; Brown, Elaine; Craft, John A; Davies, Ian M; Megginson, Colin; Miller, Colin; Moffat, Colin F

    2007-03-30

    The effects of 17beta-oestradiol (E2) on mortality, growth rates, sexual maturation, hepatic vitellogenin (VTG) mRNA expression and reproductive success were investigated during an 8-month, water-borne exposure of a marine fish, the sand goby (Pomatoschistus minutus). Indicators of oestrogenic exposure were investigated as predictors of population-level reproductive success. E2 exposure concentrations were <5 (below limit of detection), 16+/-3, 97+/-20 and 669+/-151 ng l(-1) (bootstrap means and standard errors). The carrier solvent (<20 microl l(-1) propan-2-ol) significantly reduced the rate of egg production compared to untreated fish, but did not significantly affect male VTG mRNA expression, brood size, or the other studied parameters. Fish exposed to 16 ng l(-1) E2 showed few adverse effects compared with solvent only-exposed fish. Exposure to 97 ng l(-1) E2 significantly inhibited male sexual maturation, induced male VTG mRNA expression and delayed spawning. The 97 ng l(-1) E2 exposed population also produced fertile eggs at a significantly slower rate than solvent controls; however, brood size, fertility and overall reproductive success were not significantly affected. Exposure to 669 ng l(-1) E2 significantly increased mortality, adversely affected haematological parameters and caused an almost total lack of reproductive activity, with both sexes failing to mature. Reproductive failure following exposure to 669 ng l(-1) E2 was evident in both sexes when crossed with untreated animals. This work indicates that marine fish are similarly as sensitive to oestrogenic exposure as freshwater fish, that exposure biomarkers such as VTG are more sensitive to exposure than are reproductive effects, and that the use of carrier solvents in long-term reproductive studies should be avoided. PMID:17289167

  19. Effects of chronic ozone exposure on gene expression in Arabidopsis thaliana ecotypes and in Thellungiella halophila.

    PubMed

    Li, Pinghua; Mane, Shrinivasrao P; Sioson, Allan A; Robinet, Cecilia Vasquez; Heath, Lenwood S; Bohnert, Hans J; Grene, Ruth

    2006-05-01

    Arabidopsis thaliana (At) ecotypes Columbia-0 (Col-0), Wassilewskija (WS), Cape Verde Islands (Cvi-0) and a relative, Thellungiella halophila (Th), were exposed to 20-25% over ambient ozone [O3] in a free air concentration enrichment (FACE) experiment (http://www.soyFACE. uiuc.edu), mirroring increases expected in the near future. Col-0 and WS accelerated development and developed lesions within 10 d under increased ozone, while Cvi-0 and Th grew slowly. RNAs were used in microarray hybridizations (Col-0-based 26 000 elements, 70-mer oligonucleotides). A two-step analysis of variance (ANOVA) model, including comparison with values obtained under [O3], was used for analyses. WS showed the greatest number of changes in gene expression in response to ozone. Th showed the least changes, suggesting that its expression state at [O3] was sufficient for resistance at increased ozone. Patterns observed in ambient air controls for Cvi-0 and Col-0 were most similar, while Th showed the greatest number of differences compared with the other controls. Compared with Col-0, however, Cvi-0 showed higher levels of expression of chaperones, receptor kinase-like and photosynthesis-related genes in ambient air. Cvi-0 exhibited ozone-mediated changes in a pathway involving AtSR, a homologue of the mammalian NF kappa B family of redox-sensitive transcription factors, changes in chaperones, WRKY and C2H2 proteins and antioxidants. WS displayed ozone-mediated decreases in the expression of two AtSR/NF kappa B family members, C2-domain proteins and genes associated with cell wall growth and changes in the expression of marker genes for programmed cell death (PCD), among them RCD1, a key regulator in this pathway. Microarray data were verified by reverse transcriptase (RT)-PCR. We relate O3-response diversity across the four lines to different responses among signaling and transcriptional response networks and differences in gene expression at [O3] levels. PMID:17087469

  20. A discrete-time analysis of the effects of more prolonged exposure to neighborhood poverty on the risk of smoking initiation by age 25.

    PubMed

    Kravitz-Wirtz, Nicole

    2016-01-01

    Evidence suggests that individuals who initiate smoking at younger ages are at increased risk for future tobacco dependence and continued use as well as for numerous smoking-attributable health problems. Identifying individual, household, and to a far lesser extent, contextual factors that predict early cigarette use has garnered considerable attention over the last several decades. However, the majority of scholarship in this area has been cross-sectional or conducted over relatively short windows of observation. Few studies have investigated the effects of more prolonged exposure to smoking-related risk factors, particularly neighborhood characteristics, from childhood through early adulthood. Using the 1970-2011 waves of the Panel Study of Income Dynamics merged with census data on respondents' neighborhoods, this study estimates a series of race-specific discrete-time marginal structural logit models for the risk of smoking initiation as a function of neighborhood poverty, as well as individual and household characteristics, from ages four through 25. Neighborhood selection bias is addressed using inverse-probability-of-treatment weights. Results indicate that more prolonged exposure to high (>20%) as opposed to low (<10%) poverty neighborhoods is associated with an increased risk of smoking onset by age 25, although consistent with prior literature, this effect is only evident among white and not nonwhite youth and young adults. PMID:26685707

  1. Chemical modification of coating of Pinus halepensis pollen by ozone exposure.

    PubMed

    Naas, Oumsaad; Mendez, Maxence; Quijada, Melesio; Gosselin, Sylvie; Farah, Jinane; Choukri, Ali; Visez, Nicolas

    2016-07-01

    Pollen coating, located on the exine, includes an extractible lipid fraction. The modification of the pollen coating by air pollutants may have implications on the interactions of pollen with plant stigmas and human cells. Pinus halepensis pollen was exposed to ozone in vitro and the pollen coating was extracted with organic solvent and analyzed by GC-MS. Ozone has induced chemical changes in the coating as observed with an increase in dicarboxylic acids, short-chain fatty acids and aldehydes. 4-Hydroxybenzaldehyde was identified as the main reaction product and its formation was shown to occur both on native pollen and on defatted pollen. 4-Hydroxybenzaldehyde is very likely formed via the ozonolysis of acid coumaric-like monomers constitutive of the sporopollenin. Modification of pollen coating by air pollutants should be accounted for in further studies on effect of pollution on germination and on allergenicity. PMID:27155099

  2. RESPIRATORY RESPONSE OF HUMAN EXPOSED TO LOW LEVELS OF OZONE FOR 6.6 HOURS

    EPA Science Inventory

    Recent evidence suggests that prolonged exposures of exercising men to 0.08 ppm ozone (O3) result in significant decrements in lung function, induction of respiratory symptoms, and increases in nonspecif ic airway reactivity. he purpose of this study was to confirm or refute thes...

  3. PULMONARY EFFECTS OF OZONE EXPOSURE DURING EXERCISE: DOSE-RESPONSE CHARACTERISTICS

    EPA Science Inventory

    Because minimal data are available regarding the pulmonary effects of ozone (O3) at levels < 0.27 ppm, six groups of healthy young males were exposed for 2.5 h to one of the following O3 concentrations:0.0, 0.12, 0.18, 0.24, 0.30, or 0.40 ppm. Fifteen-minute periods of rest and e...

  4. Site-specific dynamics of CD11b+ and CD103+ dendritic cell accumulations following ozone exposure

    PubMed Central

    Brand, Jeffrey D.; Ballinger, Carol A.; Tuggle, Katherine L.; Fanucchi, Michelle V.; Schwiebert, Lisa M.

    2012-01-01

    Pulmonary dendritic cells (DCs) are among the first responders to inhaled environmental stimuli such as ozone (O3), which has been shown to activate these cells. O3 reacts with epithelial lining fluid (ELF) components in an anatomically site-specific manner dictated by O3 concentration, airway flow patterns, and ELF substrate concentration. Accordingly, the anatomical distribution of ELF reaction products and airway injury are hypothesized to produce selective DC maturation differentially within the airways. To investigate how O3 affects regional airway DC populations, we utilized a model of O3-induced pulmonary inflammation, wherein C57BL/6 mice were exposed to 0.8 ppm O3 8 h/day for 1, 3, and 5 days. This model induced mild inflammation and no remarkable epithelial injury. Tracheal, but not more distant airway sites, and mediastinal lymph node (MLN) DC numbers were increased significantly after the third exposure day. The largest increase in each tissue was of the CD103+ DC phenotype. After 3 days of exposure, fewer DCs expressed CD80, CD40, and CCR7, and, at this same time point, total MLN T cell numbers increased. Together, these data demonstrate that O3 exposure induced site-specific and phenotype changes in the pulmonary and regional lymph node DC populations. Possibly contributing to ozone-mediated asthma perturbation, the phenotypic changes to DCs within pulmonary regions may alter responses to antigenic stimuli. Decreased costimulatory molecule expression within the MLN suggests induction of tolerance mechanisms; increased tracheal DC number may raise the potential for allergic sensitization and asthmatic exacerbation, thus overcoming O3-induced decrements in costimulatory molecule expression. PMID:23087018

  5. Short-term respiratory effects of 0. 12 ppm ozone exposure in volunteers with chronic obstructive pulmonary disease

    SciTech Connect

    Linn, W.S.; Fischer, D.A.; Medway, D.A.; Anzar, U.T.; Spier, C.E.; Valencia, L.M.; Venet, T.G.; Hackney, J.D.

    1982-06-01

    Twenty-five volunteers with chronic obstructive pulmonary disease of mild to moderately severe degree underwent 1-h exposures to 0.12 ppm ozone (O/sub 2/) in purified air with intermittent mild exercise. Their responses were assessed in terms of forced expiratory performance, ear oximetry, and reported symptoms. Control studied consisted of similar exposures to purified air alone. Control studies were separated from O/sub 2/ exposures by 1 month, and the order was randomized. All studies took place in a controlled-environment chamber, and were preceded by approximately 1 h of rest in a purified-air environment. No significant disturbances in forced expiratory performance or symptoms attributable to O/sub 2/ exposure were found. A slight but significant tendency to decreased arterial hemoglobin oxygen saturation (SaO/sub 2/) during exercise in O/sub 2/ was observed. The decrement in SaO/sub 2/ with O/sub 2/ relative to clean air (mean 1.3%) was near the limit of resolution of the ear oximeter test and was detected by signal averaging, thus its physiologic or clinical significance is uncertain.

  6. Effect and mechanism of waterborne prolonged Zn exposure influencing hepatic lipid metabolism in javelin goby Synechogobius hasta.

    PubMed

    Huang, Chao; Luo, Zhi; Hogstrand, Christer; Chen, Feng; Shi, Xi; Chen, Qi-Liang; Song, Yu-Feng; Pan, Ya-Xiong

    2016-07-01

    The present study was conducted to determine the effect and mechanism of waterborne Zn exposure influencing hepatic lipid deposition and metabolism in javelin goby Synechogobius hasta. S. hasta were exposed to four waterborne Zn concentrations (Zn 0.005 [control], 0.18, 0.36 and 0.55 mg l(-1) , respectively) for 60 days. Sampling occurred at days 20, 40 and 60, respectively. Zn exposure increased Zn content, declined hepatic lipid content and reduced viscerosomatic and hepatosomatic indices and lipogenic enzyme activities, including 6-phosphogluconate dehydrogenase (6PGD), glucose-6-phosphate dehydrogenase (G6PD), malic enzyme (ME) and fatty acid synthase (FAS). At days 20 and 60, Zn exposure decreased hepatic mRNA levels of 6PGD, G6PD, ME, FAS, acetyl-CoA carboxylase (ACC)α, ACCβ, hormone-sensitive lipase (HSL)a, HSLb, sterol-regulator element-binding protein (SREBP)-1, peroxisome proliferators-activated receptor (PPAR)α and PPARγ. However, the mRNA levels of CPT 1 and adipose triglyceride lipase increased following Zn exposure. On day 40, Zn exposure reduced hepatic mRNA expression of 6PGD, G6PD, ME, FAS, ACCα, ACCβ, HSLa, HSLb, SREBP-1 and PPARγ but increased mRNA expression of CPT 1, adipose triglyceride lipase and PPARα. General speaking, Zn exposure reduced hepatic lipid content by inhibiting lipogenesis and stimulating lipolysis. For the first time, the present study provided evidence that chronic Zn exposure differentially influenced mRNA expression and activities of genes and enzymes involved in lipogenic and lipolytic metabolism in a duration-dependent manner, and provided new insight into the relationship between metal elements and lipid metabolism. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26602879

  7. ISSUES AND CHALLENGES IN MODELING CHILDREN'S LONGITUDINAL EXPOSURES: AN OZONE STUDY

    EPA Science Inventory

    Modeling children's exposures is a complicated, data-intensive process. Modeling longitudinal exposures, which are important for regulatory decision making, especially for most air toxics, adds another level of complexity and data requirements. Because it is difficult to model in...

  8. Effects of Drought Stress and Ozone Exposure on Isoprene Emissions from Oak Seedlings in Texas

    NASA Astrophysics Data System (ADS)

    Madronich, M. B.; Harte, A.; Schade, G. W.

    2014-12-01

    Isoprene is the dominant hydrocarbon emitted by plants to the atmosphere with an approximate global emission of 550 Tg C yr-1. Isoprene emission studies have elucidated plants' isoprene production capacity, and the controlling factors of instantaneous emissions. However, it is not yet well understood how long-term climatic factors such as drought and increasing ozone concentrations affect isoprene emission rates. Drought reduces photosynthetic activity and is thus expected to reduce isoprene emission rate, since isoprene production relies on photosynthates. On the other hand, ozone is also known to negatively affect photosynthesis rates, but can instead increase isoprene emissions. These apparent inconsistencies and a lack of experimental data make it difficult to accurately parameterize isoprene emission responses to changing environmental conditions. The objective of this work is to reduce some of these uncertainties, using oak seedlings as a study system. Our project focuses on isoprene emission responses of oak trees to typical summer drought and high ozone conditions in Texas. We report on experiments conducted using a laboratory whole-plant chamber and leaf-level data obtained from greenhouse-grown seedlings. The chamber experiment studied the effects of ozone and drought on isoprene emissions from >3 year old oak seedlings under controlled conditions of photosynthetically active radiation (PAR), temperature, soil-moisture and the chamber's air composition. Stress in plants was induced by manipulating potted soil-moisture and ozone concentration in the chamber. The greenhouse study focused on understanding the effects of drought under Texas climatic conditions. For this study we used two year old seedlings of water oak (Quercus nigra) and post oak (Quercus stellata). Temperature, humidity and light in the greenhouse followed local conditions. Leaf-level conductance, photosynthesis measurements and isoprene sampling were carried out under controlled leaf

  9. INFLUENCE OF OZONE EXPOSURE DYNAMICS ON THE GROWTH AND YIELD OF KIDNEY BEAN (JOURNAL VERSION)

    EPA Science Inventory

    A field experiment was conducted in open-top chambers to assess the importance of peak exposure concentration and exposure frequency on the responses of kidney bean plants to O3. There were five treatments in the study: charcoal-filtered air, constant exposure to 0.05 ppm O3 (131...

  10. Prolonged inorganic arsenite exposure suppresses insulin-stimulated AKT S473 phosphorylation and glucose uptake in 3T3-L1 adipocytes: Involvement of the adaptive antioxidant response

    SciTech Connect

    Xue, Peng; Hou, Yongyong; Zhang, Qiang; Woods, Courtney G.; Yarborough, Kathy; Liu, Huiyu; Sun, Guifan; Andersen, Melvin E.; Pi, Jingbo

    2011-04-08

    Highlights: {yields} In 3T3-L1 adipocytes iAs{sup 3+} decreases insulin-stimulated glucose uptake. {yields} iAs{sup 3+} attenuates insulin-induced phosphorylation of AKT S473. {yields} iAs{sup 3+} activates the cellular adaptive oxidative stress response. {yields} iAs{sup 3+} impairs insulin-stimulated ROS signaling. {yields} iAs{sup 3+} decreases expression of adipogenic genes and GLUT4. -- Abstract: There is growing evidence that chronic exposure of humans to inorganic arsenic, a potent environmental oxidative stressor, is associated with the incidence of type 2 diabetes (T2D). One critical feature of T2D is insulin resistance in peripheral tissues, especially in mature adipocytes, the hallmark of which is decreased insulin-stimulated glucose uptake (ISGU). Despite the deleterious effects of reactive oxygen species (ROS), they have been recognized as a second messenger serving an intracellular signaling role for insulin action. Nuclear factor erythroid 2-related factor 2 (NRF2) is a central transcription factor regulating cellular adaptive response to oxidative stress. This study proposes that in response to arsenic exposure, the NRF2-mediated adaptive induction of endogenous antioxidant enzymes blunts insulin-stimulated ROS signaling and thus impairs ISGU. Exposure of differentiated 3T3-L1 cells to low-level (up to 2 {mu}M) inorganic arsenite (iAs{sup 3+}) led to decreased ISGU in a dose- and time-dependent manner. Concomitant to the impairment of ISGU, iAs{sup 3+} exposure significantly attenuated insulin-stimulated intracellular ROS accumulation and AKT S473 phosphorylation, which could be attributed to the activation of NRF2 and induction of a battery of endogenous antioxidant enzymes. In addition, prolonged iAs{sup 3+} exposure of 3T3-L1 adipocytes resulted in significant induction of inflammatory response genes and decreased expression of adipogenic genes and glucose transporter type 4 (GLUT4), suggesting chronic inflammation and reduction in GLUT4

  11. A transient increase in lipid peroxidation primes preadipocytes for delayed mitochondrial inner membrane permeabilization and ATP depletion during prolonged exposure to fatty acids.

    PubMed

    Rogers, Carlyle; Davis, Barbara; Neufer, P Darrell; Murphy, Michael P; Anderson, Ethan J; Robidoux, Jacques

    2014-02-01

    Preadipocytes are periodically subjected to fatty acid (FA) concentrations that are potentially cytotoxic. We tested the hypothesis that prolonged exposure of preadipocytes of human origin to a physiologically relevant mix of FAs leads to mitochondrial inner membrane (MIM) permeabilization and ultimately to mitochondrial crisis. We found that exposure of preadipocytes to FAs led to progressive cyclosporin A-sensitive MIM permeabilization, which in turn caused a reduction in MIM potential, oxygen consumption, and ATP synthetic capacity and, ultimately, death. Additionally, we showed that FAs induce a transient increase in intramitochondrial reactive oxygen species (ROS) and lipid peroxide production, lasting roughly 30 and 120min for the ROS and lipid peroxides, respectively. MIM permeabilization and its deleterious consequences including mitochondrial crisis and cell death were prevented by treating the cells with the mitochondrial FA uptake inhibitor etomoxir, the mitochondrion-selective superoxide and lipid peroxide antioxidants MitoTempo and MitoQ, or the lipid peroxide and reactive carbonyl scavenger l-carnosine. FAs also promoted a delayed oxidative stress phase. However, the beneficial effects of etomoxir, MitoTempo, and l-carnosine were lost by delaying the treatment by 2h, suggesting that the initial phase was sufficient to prime the cells for the delayed MIM permeabilization and mitochondrial crisis. It also suggested that the second ROS production phase is a consequence of this loss in mitochondrial health. Altogether, our data suggest that approaches designed to diminish intramitochondrial ROS or lipid peroxide accumulation, as well as MIM permeabilization, are valid mechanism-based therapeutic avenues to prevent the loss in preadipocyte metabolic fitness associated with prolonged exposure to elevated FA levels. PMID:24269897

  12. Acute Ozone (O3) Exposure Accelerates Diet-Induced Pulmonary Injury and Metabolic Alterations in a Rat Model of Type II Diabetes

    EPA Science Inventory

    Abstract for Society of Toxicology, March 22-25, 2015, San Diego, CAAcute Ozone (O3) Exposure Accelerates Diet-Induced Pulmonary Injury and Metabolic Alterations in a Rat Model of Type II DiabetesS.J. Snow1,3, D. Miller2, V. Bass2, M. Schladweiler3, A. Ledbetter3, J. Richards3, C...

  13. Effects of Acute Ozone Exposure and Methyl Jasmonate Treatment on White Pine Monoterpene and Sesquiterpene Emission Rates

    NASA Astrophysics Data System (ADS)

    Faiola, C. L.; Wagner, D.; Allwine, E.; Harley, P. C.; Vanreken, T. M.

    2010-12-01

    Biogenic volatile organic compounds (BVOCs) are produced by plants and include monoterpenes, sesquiterpenes, and their oxygenated derivatives. These BVOCs are one of the principal factors influencing the oxidative capacity of the atmosphere in forested regions, and impact both ozone concentration and secondary organic aerosol formation. Under unstressed conditions, the release of BVOCs to the atmosphere is primarily controlled by the vapor pressure of the relevant compounds within the plant tissue, which is in turn dependent on temperature as well as complex biochemical production processes. However, various natural and anthropogenic stressors can alter both the quantity and composition of the BVOCs emitted by plants. Many potential stressors are expected to become stronger as climate change effects escalate. The impacts of most stressors on BVOC emissions have not been well characterized, particularly in a field setting where changes in BVOC emissions could have influential feedbacks with climate. This study investigated the effects of two stressors on monoterpene and sesquiterpene emission rates at a field site in northern Michigan: acute ozone exposure and treatment with methyl jasmonate, an herbivory proxy. The study included six repetitions of the same experiment, each time using a new set of sub-canopy eastern white pine specimens. For each experiment, dynamic branch enclosures were simultaneously used on three specimens for sample collection: one ozone treatment tree, one methyl jasmonate treatment tree, and one control tree. Sampling lines were placed in each enclosure and VOCs were collected onto cartridges packed with Tenax GR adsorbent. Samples were collected several times per day for at least two days before treatment and for five days after treatment. Cartridges were analyzed via thermodesorption with an Agilent GC/MS/FID. This analysis allowed the identification and quantification of several monoterpene and sesquiterpene species in the samples

  14. Use of branch and whole tree exposure systems to evaluate ozone impacts on forest trees

    SciTech Connect

    Schaap, W.

    1992-01-01

    An integrated research program was carried out to study the effects of ozone on physiological processes and growth of field-grown Douglas-fir saplings over a two year period (1989-1990). The main objective was to evaluate the use of branches as a means of scaling in air pollution research with a test of the hypothesis that branches can be treated as functionally independent units. This program was unique for a number of reasons, including (a) using >3.5 m tall saplings as opposed to seedlings and (b) experimentally separating the response of the whole tree from its parts (i.e. branches).

  15. Prenatal nicotinic exposure upregulates pulmonary C-fiber NK1R expression to prolong pulmonary C-fiber-mediated apneic response.

    PubMed

    Zhao, Lei; Zhuang, Jianguo; Zang, Na; Lin, Yong; Lee, Lu-Yuan; Xu, Fadi

    2016-01-01

    Prenatal nicotinic exposure (PNE) prolongs bronchopulmonary C-fiber (PCF)-mediated apneic response to intra-atrial bolus injection of capsaicin in rat pups. The relevant mechanisms remain unclear. Pulmonary substance P and adenosine and their receptors (neurokinin-A receptor, NK1R and ADA1 receptor, ADA1R) and transient receptor potential cation channel subfamily V member 1 (TRPV1) expressed on PCFs are critical for PCF sensitization and/or activation. Here, we compared substance P and adenosine in BALF and NK1R, ADA1R, and TRPV1 expression in the nodose/jugular (N/J) ganglia (vagal pulmonary C-neurons retrogradely labeled) between Ctrl and PNE pups. We found that PNE failed to change BALF substance P and adenosine content, but significantly upregulated both mRNA and protein TRPV1 and NK1R in the N/J ganglia and only NK1R mRNA in pulmonary C-neurons. To define the role of NK1R in the PNE-induced PCF sensitization, the apneic response to capsaicin (i.v.) without or with pretreatment of SR140333 (a peripheral and selective NK1R antagonist) was compared and the prolonged apnea by PNE significantly shortened by SR140333. To clarify if the PNE-evoked responses depended on action of nicotinic acetylcholine receptors (nAChRs), particularly α7nAChR, mecamylamine or methyllycaconitine (a general nAChR or a selective α7nAChR antagonist) was administrated via another mini-pump over the PNE period. Mecamylamine or methyllycaconitine eliminated the PNE-evoked mRNA and protein responses. Our data suggest that PNE is able to elevate PCF NK1R expression via activation of nAChRs, especially α7nAChR, which likely contributes to sensitize PCFs and prolong the PCF-mediated apneic response to capsaicin. PMID:26524655

  16. Role of surfactant protein-A (SP-A) in lung injury in response to acute ozone exposure of SP-A deficient mice

    SciTech Connect

    Haque, Rizwanul; Umstead, Todd M.; Ponnuru, Padmavathi; Guo Xiaoxuan; Hawgood, Samuel; Phelps, David S.; Floros, Joanna . E-mail: jfloros@psu.edu

    2007-04-01

    Millions are exposed to ozone levels above recommended limits, impairing lung function, causing epithelial damage and inflammation, and predisposing some individuals to pneumonia, asthma, and other lung conditions. Surfactant protein-A (SP-A) plays a role in host defense, the regulation of inflammation, and repair of tissue damage. We tested the hypothesis that the lungs of SP-A(-/-) (KO) mice are more susceptible to ozone-induced damage. We compared the effects of ozone on KO and wild type (WT) mice on the C57BL/6 genetic background by exposing them to 2 parts/million of ozone for 3 or 6 h and sacrificing them 0, 4, and 24 h later. Lungs were subject to bronchoalveolar lavage (BAL) or used to measure endpoints of oxidative stress and inflammation. Despite more total protein in BAL of KO mice after a 3 h ozone exposure, WT mice had increased oxidation of protein and had oxidized SP-A dimers. In KO mice there was epithelial damage as assessed by increased LDH activity and there was increased phospholipid content. In WT mice there were more BAL PMNs and elevated macrophage inflammatory protein (MIP)-2 and monocyte chemoattractant protein (MCP)-1. Changes in MIP-2 and MCP-1 were observed in both KO and WT, however mRNA levels differed. In KO mice MIP-2 mRNA levels changed little with ozone, but in WT levels they were significantly increased. In summary, several aspects of the inflammatory response differ between WT and KO mice. These in vivo findings appear to implicate SP-A in regulating inflammation and limiting epithelial damage in response to ozone exposure.

  17. Age-related differences in pulmonary effects of acute and subchronic episodic ozone exposures in Brown Norway rats.

    PubMed

    Snow, Samantha J; Gordon, Christopher J; Bass, Virginia L; Schladweiler, Mette C; Ledbetter, Allen D; Jarema, Kimberly A; Phillips, Pamela M; Johnstone, Andrew F; Kodavanti, Urmila P

    2016-06-01

    Ozone (O3) is known to induce adverse pulmonary and systemic health effects. Importantly, children and older persons are considered at-risk populations for O3-induced dysfunction, yet the mechanisms accounting for the age-related pulmonary responses to O3 are uncertain. In this study, we examined age-related susceptibility to O3 using 1 mo (adolescent), 4 mo (young adult), 12 mo (adult) and 24 mo (senescent) male Brown Norway rats exposed to filtered air or O3 (0.25 and 1.00 ppm), 6 h/day, two days/week for 1 week (acute) or 13 weeks (subchronic). Ventilatory function, assessed by whole-body plethysmography, and bronchoalveolar lavage fluid (BALF) biomarkers of injury and inflammation were used to examine O3-induced pulmonary effects. Relaxation time declined in all ages following the weekly exposures; however, this effect persisted only in the 24 mo rats following a five days recovery, demonstrating an inability to induce adaptation commonly seen with repeated O3 exposures. PenH was increased in all groups with an augmented response in the 4 mo rats following the subchronic O3 exposures. O3 led to increased breathing frequency and minute volume in the 1 and 4 mo animals. Markers of pulmonary permeability were increased in all age groups. Elevations in BALF γ-glutamyl transferase activity and lung inflammation following an acute O3 exposure were noted in only the 1 and 4 mo rats, which likely received an increased effective O3 dose. These data demonstrate that adolescent and young adult animals are more susceptible to changes in ventilation and pulmonary injury/inflammation caused by acute and episodic O3 exposure. PMID:27097751

  18. A critical review and analysis of the use of exposure- and flux-based ozone indices for predicting vegetation effects

    NASA Astrophysics Data System (ADS)

    Musselman, Robert C.; Lefohn, Allen S.; Massman, William J.; Heath, Robert L.

    Early studies of plant response to ozone (O 3) utilized concentration-based metrics, primarily by summarizing the commonly monitored hourly average data sets. Research with the O 3 concentration parameter led to the recognition that both peak concentrations and cumulative effects are important when relating plant response to O 3. The US and Canada currently use O 3 concentration-based (exposure-based) parameters for ambient air quality standards for protecting vegetation; the European countries use exposure-based critical levels to relate O 3 to vegetation response. Because plant response is thought to be more closely related to O 3 absorbed into leaf tissue, recent research has been focused on flux-based O 3 parameters. Even though flux-based indices may appear to be more biologically relevant than concentration-based indices, there are limitations associated with their use. The current set of flux-based indices assumes that the plant has no defense mechanism to detoxify O 3. This is a serious limitation. In this paper, we review the literature on exposure- and flux-based indices for predicting plant response. Both exposure- and flux-based metrics may overestimate plant response. At this time, flux-based models that take into consideration detoxification mechanisms (referred to as effective flux) provide the best approach to relate O 3 to plant response. However, because there is considerable uncertainty in quantifying the various defense mechanisms, effective flux at this time is difficult to quantify. Without adequate effective-flux based models, exposure-based O 3 metrics appear to be the only practical measure for use in relating ambient air quality standards to vegetation response.

  19. Prolonged Exposure to HIV Reinforces a Poised Epigenetic Program for PD-1 Expression in Virus-specific CD8 T Cells

    PubMed Central

    Youngblood, Ben; Noto, Alessandra; Porichis, Filippos; Akondy, Rama S.; Ndhlovu, Zaza M.; Austin, James W.; Bordi, Rebeka; Procopio, Francesco A.; Miura, Toshiyuki; Allen, Todd M.; Sidney, John; Sette, Alessandro; Walker, Bruce D.; Ahmed, Rafi; Boss, Jeremy M.; Sékaly, Rafick-Pierre; Kaufmann, Daniel E.

    2013-01-01

    Antigen-specific CD8 T cells play a critical role in controlling HIV infection but eventually lose antiviral functions in part because of expression and signaling through the inhibitory PD-1 receptor. To better understand the impact of prolonged TCR ligation on regulation of PD-1 expression in HIV-specific CD8 T cells we investigated the capacity of virus-specific CD8 T cells to modify the PD-1 epigenetic program following reduction in viral load. We observed that the transcriptional regulatory region was unmethylated in the PD-1hi HIV-specific CD8 T cells while it remained methylated in donor matched naïve cells at acute and chronic stages of infection. Surprisingly, the PD-1 promoter remained unmethylated in HIV-specific CD8 T cells from subjects with a viral load controlled by antiviral therapy for greater than 2 years or from elite controllers. Together these data demonstrate that the epigenetic program at the PD-1 locus becomes fixed following prolonged exposure to HIV virus. PMID:23772031

  20. Inflammatory suppressive effect of prostate cancer cells with prolonged exposure to transforming growth factor β on macrophage-differentiated cells via downregulation of prostaglandin E2.

    PubMed

    Hayashi, Akinobu; Hirokawa, Yoshifumi S; Kagaya, Michiko; Fujiwara, Masaya; Yoneda, Misao; Kanayama, Kazuki; Uchida, Katsunori; Ishii, Kenichiro; Shiraishi, Taizo

    2014-10-01

    Transforming growth factor β1 (TGFβ1) regulates a variety of cellular functions, including cell growth, apoptosis and differentiation. The aim of the current study was to investigate the alterations of phenotypic events in the long-term exposure of prostate cancer (PCa) cells to TGFβ1 and its effect on macrophage-differentiated cells. The PCa cell line, PC-3, and the subclone, M1, were exposed to TGFβ1 for short- or long-term periods. TGFβ1 signaling was assessed by Smad3 phosphorylation, and non-canonical signaling was analyzed by quantitative polymerase chain reaction-based regulatory gene expression profiles. TGFβ1-exposed PCa cells were also co-cultured with phorbol 12-myristate 13-acetate (PMA)-treated THP-1 macrophages as a model of the tumor microenvironment. The phosphorylation of Smad3 in the PCa cells with long-term exposure was lower than that in the PCa cells with short-term exposure. Interleukin-6 mRNA expression in the PMA-treated THP-1 macrophages was significantly downregulated by co-culture with the PCa cells with long-term exposure. Cyclooxygenase-2 expression in the long-term TGFβ1-exposed PCa cells was lower than that in the control PCa cells, and the production of prostaglandin E2 (PGE2) in the long-term TGFβ1-exposed PCa cells was also significantly lower. The results of the current study demonstrated that the long-term TGFβ1 exposure of PCa cells induces phenotypic changes, including the downregulation of PGE2 production. This indicates that prolonged TGFβ-exposed PCa cells may change the cytokine production of macrophages in the tumor microenvironment. PMID:25202359

  1. Influence of ozone and paracetic acid disinfection on adhesion of resilient liners to acrylic resin

    PubMed Central

    2016-01-01

    PURPOSE The aim of this study was to evaluate the effect of paracetic acid (PAA) and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient liners to acrylic resins. MATERIALS AND METHODS One hundred and twenty dumbbell shaped heat-polymerized acrylic resins were prepared. From the mid segment of the specimens, 3 mm of acrylic were grinded off and separated parts were reattached by resilient liners. The specimens were divided into 2 control (control1, control7) and 4 test groups of PAA and ozone disinfection (PAA1, PAA7, ozone1 and ozone7; n=10). While control groups were immersed in distilled water for 10 min (control1) and 7 days (control7), test groups were subjected to PAA (16 g/L) or ozone rich water (4 mg/L) for 1 cycle (10 min for PAA and 60 min for ozone) per day for 7 days prior to tensile tests. Measurements of the TBS were analyzed using 3-way ANOVA and Tukey's HSD test. RESULTS Adhesive strength of Mollosil decreased significantly by application of ozone disinfection. PAA disinfection had no negative effect on the TBS values of Mollosil and Molloplast B to acrylic resin. Single application of ozone disinfection did not have any negative effect on TBS values of Molloplast B, but prolonged exposure to ozone decreased its adhesive strength. CONCLUSION The adhesion of resilient liners to acrylic was not adversely affected by PAA disinfection. Immersion in ozonated water significantly decreased TBS of Mollosil. Prolonged exposure to ozone negatively affects adhesion of Molloplast B to denture base materials. PMID:27555898

  2. A comparison of cognitive-processing therapy with prolonged exposure and a waiting condition for the treatment of chronic posttraumatic stress disorder in female rape victims.

    PubMed

    Resick, Patricia A; Nishith, Pallavi; Weaver, Terri L; Astin, Millie C; Feuer, Catherine A

    2002-08-01

    The purpose of this study was to compare cognitive-processing therapy (CPT) with prolonged exposure and a minimal attention condition (MA) for the treatment of posttraumatic stress disorder (PTSD) and depression. One hundred seventy-one female rape victims were randomized into 1 of the 3 conditions, and 121 completed treatment. Participants were assessed with the Clinician-Administered PTSD Scale, the PTSD Symptom Scale, the Structured Clinical Interview for DSM-IV, the Beck Depression Inventory, and the Trauma-Related Guilt Inventory. Independent assessments were made at pretreatment, posttreatment, and 3 and 9 months posttreatment. Analyses indicated that both treatments were highly efficacious and superior to MA. The 2 therapies had similar results except that CPT produced better scores on 2 of 4 guilt subscales. PMID:12182270

  3. Association of short-term exposure to ground-level ozone and respiratory outpatient clinic visits in a rural location – Sublette County, Wyoming, 2008–2011

    SciTech Connect

    Pride, Kerry R.; Peel, Jennifer L.; Robinson, Byron F.; Busacker, Ashley; Grandpre, Joseph; Bisgard, Kristine M.; Yip, Fuyuen Y.; Murphy, Tracy D.

    2015-02-15

    Objective: Short-term exposure to ground-level ozone has been linked to adverse respiratory and other health effects; previous studies typically have focused on summer ground-level ozone in urban areas. During 2008–2011, Sublette County, Wyoming (population: ~10,000 persons), experienced periods of elevated ground-level ozone concentrations during the winter. This study sought to evaluate the association of daily ground-level ozone concentrations and health clinic visits for respiratory disease in this rural county. Methods: Clinic visits for respiratory disease were ascertained from electronic billing records of the two clinics in Sublette County for January 1, 2008–December 31, 2011. A time-stratified case-crossover design, adjusted for temperature and humidity, was used to investigate associations between ground-level ozone concentrations measured at one station and clinic visits for a respiratory health concern by using an unconstrained distributed lag of 0–3 days and single-day lags of 0 day, 1 day, 2 days, and 3 days. Results: The data set included 12,742 case-days and 43,285 selected control-days. The mean ground-level ozone observed was 47±8 ppb. The unconstrained distributed lag of 0–3 days was consistent with a null association (adjusted odds ratio [aOR]: 1.001; 95% confidence interval [CI]: 0.990–1.012); results for lags 0, 2, and 3 days were consistent with the null. However, the results for lag 1 were indicative of a positive association; for every 10-ppb increase in the 8-h maximum average ground-level ozone, a 3.0% increase in respiratory clinic visits the following day was observed (aOR: 1.031; 95% CI: 0.994–1.069). Season modified the adverse respiratory effects: ground-level ozone was significantly associated with respiratory clinic visits during the winter months. The patterns of results from all sensitivity analyzes were consistent with the a priori model. Conclusions: The results demonstrate an association of increasing ground

  4. Increased responsiveness of rat dorsal horn neurons in vivo following prolonged intrathecal exposure to interferon-gamma.

    PubMed

    Vikman, K S; Siddall, P J; Duggan, A W

    2005-01-01

    Prolonged increases in the level of the pro-inflammatory cytokine interferon-gamma occur in the CNS during some disease states associated with persistent pain. Administration of interferon-gamma to both humans and rodents has produced pain or pain-related behavior but the underlying mechanisms are unknown. The present study examined the effects of repeated intrathecal administration of interferon-gamma on dorsal horn neuronal responses under in vivo conditions. In addition, behavioral effects of interferon-gamma treatment were studied. Intrathecal cannulae were implanted into anesthetized rats. Animals then received either 1000 U of recombinant rat interferon-gamma in 10 microl buffer intrathecally, repeated four times over 8 days, or similarly administered buffer (controls). Interferon-gamma-treated animals showed a significant reduction in paw withdrawal threshold to mechanical stimulation of the hind paw. Electrophysiological experiments were performed under halothane anesthesia. Extracellular recordings of spontaneous and evoked responses were obtained from dorsal horn neurons (n=64) in the lumbar spinal cord. There was a significantly higher proportion of spontaneously active neurons in the interferon-gamma-treated animals (50%) when compared with controls (19%). A significantly increased proportion of neurons from interferon-gamma-treated animals displayed afterdischarges following both innocuous and noxious mechanical stimulation of the receptive field (brush: 21% in interferon-gamma-treated, 3% in controls; pinch: 97% in interferon-gamma-treated, 50% in controls). Neurons from interferon-gamma-treated animals also showed significantly increased wind-up of action potentials in response to repeated electrical stimulation of the sciatic nerve at C-fiber strength at both 0.5 and 1 Hz. Paired-pulse inhibition, evoked through electrical stimulation of the cutaneous receptive field, was significantly decreased in neurons from interferon-gamma-treated animals at 50

  5. Ozone exposure and cardiovascular-related mortality in the Canadian Census Health and Environment Cohort (CANCHEC) by spatial synoptic classification zone.

    PubMed

    Cakmak, Sabit; Hebbern, Chris; Vanos, Jennifer; Crouse, Dan L; Burnett, Rick

    2016-07-01

    Our objective is to analyse the association between long term ozone exposure and cardiovascular related mortality while accounting for climate, location, and socioeconomic factors. We assigned subjects with 16 years of follow-up in the Canadian Census Health and Environment Cohort (CanCHEC) to one of seven regions based on spatial synoptic classification (SSC) weather types and examined the interaction of exposure to both fine particulate matter (PM2.5) and ground level ozone and cause of death using survival analysis, while adjusting for socioeconomic characteristics and individual confounders. Correlations between ozone and PM2.5 varied across SSC zones from -0.02 to 0.7. Comparing zones using the most populated SSC zone as a reference, a 10 ppb increase in ozone exposure was associated with increases in hazard ratios (HRs) that ranged from 1.007 (95% CI 0.99, 1.015) to 1.03 (95% CI 1.02, 1.041) for cardiovascular disease, 1.013 (95% CI 0.996, 1.03) to 1.058 (95% CI 1.034, 1.082) for cerebrovascular disease, and 1.02 (95% CI 1.006, 1.034) for ischemic heart disease. HRs remained significant after adjustment for PM2.5. Long term exposure to ozone is related to an increased risk of mortality from cardiovascular and cerebrovascular diseases; the risk varies by location across Canada and is not attenuated by adjustment for PM2.5. This research shows that the SSC can be used to define geographic regions and it demonstrates the importance of accounting for that spatial variability when studying the long term health effects of air pollution. PMID:27131819

  6. DETERMINATION OF THE EFFECTS OF MATERIAL FROM ALTERNATE ENERGY SOURCES ON THE UPPER RESPIRATORY TRACT CLEARANCE MECHANISM. PART I: IN VITRO EXPOSURE TO PARTICULATE POLLUTANTS. PART II: IN VIVO EXPOSURE TO OZONE

    EPA Science Inventory

    Studies were conducted to measure the toxic effects of a variety of substances from the environment on the clearance mechanism of the upper respiratory tract using an in vitro hamster model system. Studies using hamsters for in vivo exposures to ozone were also conducted to deter...

  7. Brief low [Mg2+]o-induced Ca2+ spikes inhibit subsequent prolonged exposure-induced excitotoxicity in cultured rat hippocampal neurons

    PubMed Central

    Kim, Hee Jung; Yang, Ji Seon

    2016-01-01

    Reducing [Mg2+]o to 0.1 mM can evoke repetitive [Ca2+]i spikes and seizure activity, which induces neuronal cell death in a process called excitotoxicity. We examined the issue of whether cultured rat hippocampal neurons preconditioned by a brief exposure to 0.1 mM [Mg2+]o are rendered resistant to excitotoxicity induced by a subsequent prolonged exposure and whether Ca2+ spikes are involved in this process. Preconditioning by an exposure to 0.1 mM [Mg2+]o for 5 min inhibited significantly subsequent 24 h exposure-induced cell death 24 h later (tolerance). Such tolerance was prevented by both the NMDA receptor antagonist D-AP5 and the L-type Ca2+ channel antagonist nimodipine, which blocked 0.1 mM [Mg2+]o-induced [Ca2+]i spikes. The AMPA receptor antagonist NBQX significantly inhibited both the tolerance and the [Ca2+]i spikes. The intracellular Ca2+ chelator BAPTA-AM significantly prevented the tolerance. The nonspecific PKC inhibitor staurosporin inhibited the tolerance without affecting the [Ca2+]i spikes. While Gö6976, a specific inhibitor of PKCα had no effect on the tolerance, both the PKCε translocation inhibitor and the PKCζ pseudosubstrate inhibitor significantly inhibited the tolerance without affecting the [Ca2+]i spikes. Furthermore, JAK-2 inhibitor AG490, MAPK kinase inhibitor PD98059, and CaMKII inhibitor KN-62 inhibited the tolerance, but PI-3 kinase inhibitor LY294,002 did not. The protein synthesis inhibitor cycloheximide significantly inhibited the tolerance. Collectively, these results suggest that low [Mg2+]o preconditioning induced excitotoxic tolerance was directly or indirectly mediated through the [Ca2+]i spike-induced activation of PKCε and PKCξ, JAK-2, MAPK kinase, CaMKII and the de novo synthesis of proteins. PMID:26807029

  8. Oxidative stress caused by ozone exposure induces β-amyloid 1-42 overproduction and mitochondrial accumulation by activating the amyloidogenic pathway.

    PubMed

    Hernández-Zimbrón, L F; Rivas-Arancibia, S

    2015-09-24

    Oxidative stress is a major risk factor for Alzheimer's disease (AD) that has been suggested to be the trigger of AD pathology. However, whether oxidative damage precedes and contributes directly to the intracellular accumulation of beta amyloid 1-42 (βA42) peptide remains a matter of debate. Chronic exposure to low doses of ozone similar to the levels during a day of high pollution in México City causes a state of oxidative stress that elicits progressive neurodegeneration in the hippocampi of rats. Several reports have demonstrated that the mitochondria are among the first organelles to be affected by oxidative stress and βA42 toxicity and act as sites of the accumulation of βA42, which affects energy metabolism. However, the mechanisms related to the neurodegeneration process and organelle damage that occur in conditions of chronic exposure to low doses of ozone have not been demonstrated. To analyze the effect of chronic ozone chronic exposure on changes in the production and accumulation of the βA42 and βA40 peptides in the mitochondria of hippocampal neurons of rats exposed to ozone, we examined the mitochondrial expression levels of Presenilins 1 and 2 and ADAM10 to detect changes related to the oxidative stress caused by low doses of ozone (0.25ppm). The results revealed significant accumulations of βA42 peptide in the mitochondrial fractions on days 60 and 90 of ozone exposure along with reductions in beta amyloid 1-40 accumulation, significant overexpressions of Pres2 and significant reductions in ADAM10 expression. Beta amyloid immunodetection revealed that there were some intracellular deposits of βA42 and that βA42 and the mitochondrial markers OPA1 and COX1 colocalized. These results indicate that the time of exposure to ozone and the accumulation of βA42 in the mitochondria of the hippocampal cells of rats were correlated. Our results suggest that the accumulation of the βA42 peptide may promote mitochondrial dysfunction due to its

  9. Clinical and pathological manifestations of cardiovascular disease in rat models: the influence of acute ozone exposure

    EPA Science Inventory

    This paper shows that rat models of cardiovascular diseases have differential degrees of underlying pathologies at a young age. Rodent models of cardiovascular diseases (CVD) and metabolic disorders are used for examining susceptibility variations to environmental exposures. How...

  10. Effects of drought and canopy ozone exposure on antioxidants in fine roots of mature European beech (Fagus sylvatica).

    PubMed

    Haberer, Kristine; Herbinger, Karin; Alexou, Maria; Rennenberg, Heinz; Tausz, Michael

    2008-05-01

    We quantified ascorbate, glutathione and alpha-tocopherol in fine roots of mature Fagus sylvatica L. under free-air canopy ozone (O(3)) exposure (twice ambient O(3) concentration, 2x[O(3)]) during two growing seasons that differed in the extent of summer drought (exceptional drought year 2003, average year 2004). This design allowed us to test whether O(3) exposure or drought, or both, affected root antioxidants during the growing season. In both years, root ascorbate and alpha-tocopherol showed a similar relationship with volumetric soil water content (SWC): ascorbate concentrations on a root dry mass basis increased from about 6 to 12 micromol g(-1) when SWC dropped from 25 to 20%, and a-tocopherol increased from 100 to 150 nmol g(-1) at SWC values below 20%. Root glutathione showed no relationship with SWC or differences between the dry and the average year, but it was significantly and consistently diminished by 2x[O(3)]. Our results were inconclusive as to whether shoot-root translocation of glutathione or glutathione production in the roots was diminished. Phloem glutathione concentrations in the canopy remained constant, but reduced transport velocity in the phloem and, as a consequence, reduced mass flow of glutathione cannot be ruled out. PMID:18316303

  11. Effects of ozone exposure on lipid metabolism in human alveolar macrophages

    SciTech Connect

    Friedman, M.; Madden, M.C.; Samet, J.M.; Koren, H.S.

    1991-01-01

    Alveolar macrophages (AM) store arachidonic acid (AA) which is esterified in cellular phospholipids until liberated by phospholipase A2 or C after exposure to inflammatory stimuli. Following release, there can be subsequent metabolism of AA into various potent, biological active mediators including prostaglandins and platelet activating factor (PAF). To examine the possibility that these mediators may account for some of the pathophysiologic alterations seen in the lung following O3 exposure, human AM were collected by bronchoalveolar lavage of normal subjects, plated into tissue culture dishes, and the adherent cells were incubated with 3H-AA or 3H-lysoPAF. Human AM exposed 1.0 ppm O3 for 2 hr released 65 + or - 12% more tritium, derived from 3H-AA, than paired air-exposed controls into media supernatants. In other studies using a similar O3 exposure protocol, there was also a significant increase in human AM PGE2 production (2.0 + or - 0.5 fold-increase above air-exposure values, p<0.01, n=17). In additional studies, using a similar O3 exposure protocol (1.0 ppm for 1 hr), there was also a significant increase in human AM PAF content (1.7 + or - 0.2 fold-increase above air-exposure values, p<0.02, n=5).

  12. Influence of ozone-exposure dynamics on the growth and yield of kidney bean (journal version)

    SciTech Connect

    Kohut, R.J.; Laurence, J.A.; Colavito, L.J.

    1988-01-01

    A field experiment was conducted in open-top chambers to assess the importance of peak exposure concentration and exposure frequency on the responses of kidney bean plants to O/sub 3/. There were five treatments in the study: charcoal-filtered air, constant exposure to 0.05 ppm O/sub 3/ (131 micrograms/cu m) daily, fluctuating exposure to 0.08 ppm O/sub 3/ on three alternate days, cluster exposure to 0.08 ppm O/sub 3/ on three consecutive days, and peak exposure to 0.12 ppm O/sub 3/ on two consecutive days. There were no significant effects of the O/sub 3/-addition treatments on yield when compared to the plants receiving charcoal-filtered air. This indicates that there were no cumulative impacts on plants exposed to 0.12 ppm O/sub 3/ for 4h on two consecutive days followed by filtered air compared to plants receiving charcoal-filtered air. The seasonal 7-h average concentrations of O/sub 3/ in the peak and filtered-air treatments were approximately 0.040 and 0.025 ppm, respectively.

  13. Pulmonary Responses in Healthy Young Adults Exposed to Low Concentration of Ozone for 6.6 Hours with Mild Exercise

    EPA Science Inventory

    Rational: Recent studies have shown small but significant decreases in lung function following a prolonged exposure (6.6 hour) of healthy young adults to levels of ozone (0.08 ppm) near the current 8 hour standard. It is unclear, however, if such effects may be extended to concen...

  14. Prolonged exposure to (R)-bicalutamide generates a LNCaP subclone with alteration of mitochondrial genome.

    PubMed

    Pignatta, Sara; Arienti, Chiara; Zoli, Wainer; Di Donato, Marzia; Castoria, Gabriella; Gabucci, Elisa; Casadio, Valentina; Falconi, Mirella; De Giorgi, Ugo; Silvestrini, Rosella; Tesei, Anna

    2014-01-25

    Advanced prostate cancers, initially sensitive to androgen deprivation therapy, frequently progress to the castration-resistant prostate cancer phenotype (CRPC) through mechanisms not yet fully understood. In this study we investigated mitochondrial involvement in the establishment of refractoriness to hormone therapy. Two human prostate cancer cell lines were used, the parental LNCaP and the resistant LNCaP-Rbic, the latter generated after continuous exposure to 20 μM of (R)-bicalutamide, the active enantiomer of Casodex®. We observed a significant decrease in mtDNA content and a lower expression of 8 mitochondria-encoded gene transcripts involved in respiratory chain complexes in both cell lines. We also found that (R)-bicalutamide differentially modulated dynamin-related protein (Drp-1) expression in LNCaP and LNCaP-Rbic cells. These data seem to indicate that the androgen-independent phenotype in our experimental model was due, at least in part, to alterations in mitochondrial dynamics and to a breakdown in the Drp-1-mediated mitochondrial network. PMID:24397920

  15. Using air quality modeling to study source-receptor relationships between nitrogen oxides emissions and ozone exposures over the United States.

    PubMed

    Tong, Daniel Q; Muller, Nicholas Z; Kan, Haidong; Mendelsohn, Robert O

    2009-11-01

    Human exposure to ambient ozone (O(3)) has been linked to a variety of adverse health effects. The ozone level at a location is contributed by local production, regional transport, and background ozone. This study combines detailed emission inventory, air quality modeling, and census data to investigate the source-receptor relationships between nitrogen oxides (NO(x)) emissions and population exposure to ambient O(3) in 48 states over the continental United States. By removing NO(x) emissions from each state one at a time, we calculate the change in O(3) exposures by examining the difference between the base and the sensitivity simulations. Based on the 49 simulations, we construct state-level and census region-level source-receptor matrices describing the relationships among these states/regions. We find that, for 43 receptor states, cumulative NO(x) emissions from upwind states contribute more to O(3) exposures than the state's own emissions. In-state emissions are responsible for less than 15% of O(3) exposures in 90% of U.S. states. A state's NO(x) emissions can influence 2 to 40 downwind states by at least a 0.1 ppbv change in population-averaged O(3) exposure. The results suggest that the U.S. generally needs a regional strategy to effectively reduce O(3) exposures. But the current regional emission control program in the U.S. is a cap-and-trade program that assumes the marginal damage of every ton of NO(x) is equal. In this study, the average O(3) exposures caused by one ton of NO(x) emissions ranges from -2.0 to 2.3 ppm-people-hours depending on the state. The actual damage caused by one ton of NO(x) emissions varies considerably over space. PMID:19656569

  16. Conservation of body calcium by increased dietary intake of potassium: A potential measure to reduce the osteoporosis process during prolonged exposure to microgravity

    NASA Technical Reports Server (NTRS)

    Nechay, Bohdan R.

    1989-01-01

    During the 1988 NASA Summer Faculty Fellowship Program, it was proposed that the loss of skeletal calcium upon prolonged exposure to microgravity could be explained, in part, by a renal maladjustment characterized by an increased urinary excretion of calcium. It was theorized that because the conservation of body fluids and electrolytes depends upon the energy of adenosine triphosphate and enzymes that control the use of its energy for renal ion transport, an induction of renal sodium and potassium-dependent adenosine triphosphatase (Na + K ATPase) by oral loading with potassium would increase the reabsorption of sodium directly and that of calcium indirectly, leading to improved hydration and to reduced calcium loss. Preliminary studies showed the following. Rats drinking water containing 0.2 M potassium chloride for six to 13 days excreted in urine 22 muEq of calcium and 135 muEq of sodium per 100 grams of body weight per day. The corresponding values for control rats drinking tap water were 43 muEq and 269 muEq respectively. Renal Na + K ATPase activity in potassium loaded rats was higher than in controls. Thus, oral potassium loading resulted in increased Na + K ATPase activity and diminished urinary excretion of calcium and of sodium as predicted by the hypothesis. An extension of these studies to humans has the potential of resulting in development of harmless, non-invasive, drug-free, convenient measures to reduce bone loss and other electrolyte and fluid problems in space travelers exposed to prolonged periods of microgravity.

  17. Growth of radish and marigold following repeated exposure to nitrogen dioxide, sulfur dioxide, and ozone

    SciTech Connect

    Reinert, R.A.; Sanders, J.S.

    1982-02-01

    Radish and marigold plants were exposed to 0.3 ppm of nitrogen dioxide (NO/sub 2/), sulfur dioxide (SO/sub 2/), and/or ozone (O/sub 3/) nine times during a 3-wk period. No interactions among NO/sub 2/, SO/sub 2/, and O/sub 3/ were detected in measurement of radish foliage and root dry weight. Treatments containing O/sub 3/ reduced radish foliage and root (hypocotyl) dry weight 356 and 531 mg/plant, respectively. Interactions among NO/sub 2/, SO/sub 2/, and O/sub 3/ occurred in shoots and roots of marigold. SO/sub 2/ alone reduced marigold shoot and root dry weight, but this effect was reversed in the presence of O/sub 3/. The suppressive effect of SO/sub 2/ on root weight was also reversed by NO/sub 3/. Treatments containing SO/sub 2/ reduced dry flower weight 0.17 g/plant, but effects of the pollutant interactions observed in shoots and roots were not present.

  18. Growth of radish and marigold following repeated exposure to nitrogen dioxide, sulfur dioxide, and ozone

    SciTech Connect

    Reinert, R.A.; Sanders, J.S.

    1982-02-01

    Radish and marigold plants were exposed to 0.3 ppM of nitrogen dioxide (NO/sub 2/), sulfur dioxide (SO/sub 2/), and /or ozone (O/sub 3/) nine times during a 3-wk period. No interactions among NO/sub 2/, SO/sub 2/, and O/sub 3/ were detected in measurement of radish foliage and root dry weight. Treatments containing O/sub 3/ reduced radish foliage and root (hypocotyl) dry weight 356 and 531 mg/plant, respectively. Interactions among NO/sub 2/, SO/sub 2/ and O/sub 3/ occurred in shoots and roots of marigold. SO/sub 2/ alone reduced marigold shoot and root dry weight, but this effect was reversed in the presence of O/sub 3/. The suppressive effect of SO/sub 2/ on root weight was also reversed by NO/sub 2/. Treatments containing SO/sub 2/ reduced dry flower weight 0.17 g/plant, but effects of the pollutant interactions observed in shoots and roots were not present. 8 references, 2 tables.

  19. Beta-lactam antibiotic-induced platelet dysfunction: Evidence for irreversible inhibition of platelet activation in vitro and in vivo after prolonged exposure to penicillin

    SciTech Connect

    Burroughs, S.F.; Johnson, G.J. )

    1990-04-01

    beta-Lactam antibiotics cause platelet dysfunction with bleeding complications. Previous in vitro studies documented reversible inhibition of agonist-receptor interaction. This mechanism is inadequate to explain the effect of beta-lactam antibiotics in vivo. Platelet function does not return to normal immediately after drug treatment, implying irreversible inhibition of platelet function. We report here evidence of irreversible platelet functional and biochemical abnormalities after in vitro and in vivo exposure to beta-lactam antibiotics. Irreversible binding of (14C)-penicillin (Pen) occurred in vitro. After 24 hours' in vitro incubation with 10 to 20 mmol/L Pen, or ex vivo after antibiotic treatment, irreversible functional impairment occurred; but no irreversible inhibition of alpha 2 adrenergic receptors, measured with (3H)-yohimbine, or high-affinity thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptors, measured with agonist (3H)-U46619 and antagonist (3H)-SQ29548, occurred. However, low-affinity platelet TXA2/PGH2 receptors were decreased 40% after Pen exposure in vitro or in vivo, indicating irreversible membrane alteration. Two postreceptor biochemical events were irreversibly inhibited in platelets incubated with Pen for 24 hours in vitro or ex vivo after antibiotic treatment. Thromboxane synthesis was inhibited 28.3% to 81.7%. Agonist-induced rises in cytosolic calcium ((Ca2+)i) were inhibited 40.1% to 67.5% in vitro and 26.6% to 52.2% ex vivo. Therefore, Pen binds to platelets after prolonged exposure, resulting in irreversible dysfunction attributable to inhibition of TXA2 synthesis and impairment of the rise in (Ca2+)i. The loss of low-affinity TXA2/PGH2 receptors suggests that the primary site of action of these drugs is on the platelet membrane.

  20. A Bayesian model for quantifying the change in mortality associated with future ozone exposures under climate change.

    PubMed

    Alexeeff, Stacey E; Pfister, Gabriele G; Nychka, Doug

    2016-03-01

    Climate change is expected to have many impacts on the environment, including changes in ozone concentrations at the surface level. A key public health concern is the potential increase in ozone-related summertime mortality if surface ozone concentrations rise in response to climate change. Although ozone formation depends partly on summertime weather, which exhibits considerable inter-annual variability, previous health impact studies have not incorporated the variability of ozone into their prediction models. A major source of uncertainty in the health impacts is the variability of the modeled ozone concentrations. We propose a Bayesian model and Monte Carlo estimation method for quantifying health effects of future ozone. An advantage of this approach is that we include the uncertainty in both the health effect association and the modeled ozone concentrations. Using our proposed approach, we quantify the expected change in ozone-related summertime mortality in the contiguous United States between 2000 and 2050 under a changing climate. The mortality estimates show regional patterns in the expected degree of impact. We also illustrate the results when using a common technique in previous work that averages ozone to reduce the size of the data, and contrast these findings with our own. Our analysis yields more realistic inferences, providing clearer interpretation for decision making regarding the impacts of climate change. PMID:26302149

  1. Cyclic AMP-elevating agents prolong or inhibit eosinophil survival depending on prior exposure to GM-CSF.

    PubMed Central

    Hallsworth, M. P.; Giembycz, M. A.; Barnes, P. J.; Lee, T. H.

    1996-01-01

    and dibutyryl cyclic AMP respectively. 8. In conclusion, cyclic AMP exerts opposing effects on eosinophil survival depending on prior exposure of the cells to GM-CSF. Images Figure 5 PMID:8825346

  2. Exposure assessment of air pollutants: a review on spatial heterogeneity and indoor/outdoor/personal exposure to suspended particulate matter, nitrogen dioxide and ozone

    NASA Astrophysics Data System (ADS)

    Monn, Christian

    This review describes databases of small-scale spatial variations and indoor, outdoor and personal measurements of air pollutants with the main focus on suspended particulate matter, and to a lesser extent, nitrogen dioxide and photochemical pollutants. The basic definitions and concepts of an exposure measurement are introduced as well as some study design considerations and implications of imprecise exposure measurements. Suspended particulate matter is complex with respect to particle size distributions, the chemical composition and its sources. With respect to small-scale spatial variations in urban areas, largest variations occur in the ultrafine (<0.1 μm) and the coarse mode (PM 10-2.5, resuspended dust). Secondary aerosols which contribute to the accumulation mode (0.1-2 μm) show quite homogenous spatial distribution. In general, small-scale spatial variations of PM 2.5 were described to be smaller than the spatial variations of PM 10. Recent studies in outdoor air show that ultrafine particle number counts have large spatial variations and that they are not well correlated to mass data. Sources of indoor particles are from outdoors and some specific indoor sources such as smoking and cooking for fine particles or moving of people (resuspension of dust) for coarse particles. The relationships between indoor, outdoor and personal levels are complex. The finer the particle size, the better becomes the correlation between indoor, outdoor and personal levels. Furthermore, correlations between these parameters are better in longitudinal analyses than in cross-sectional analyses. For NO 2 and O 3, the air chemistry is important. Both have considerable small-scale spatial variations within urban areas. In the absence of indoor sources such as gas appliances, NO 2 indoor/outdoor relationships are strong. For ozone, indoor levels are quite small. The study hypothesis largely determines the choice of a specific concept in exposure assessment, i.e. whether personal

  3. EFFECTS OF OZONE EXPOSURE ON LIPID METABOLISM IN HUMAN ALVEOLAR MACROPHAGES

    EPA Science Inventory

    Alveolar macrophages (AM) store arachidonic acid (AA) which is esterified in cellular phospholipids until liberated by phospholipase A2 or C after exposure to inflammatory stimuli. ollowing release, there can be subsequent metabolism of AA into various potent, biological active m...

  4. Overview of ozone bleaching

    SciTech Connect

    Sonnenberg, L.B.

    1995-12-31

    The potential impact of the pulp and paper industry on the environment may be reduced by replacing chlorine-based bleaching reagents with ozone. The reactivity of ozone coupled with the heterogeneity of pulp allows many types of reactions to occur during pulp bleaching. Ozone cleaves the aromatic rings and side chain double bonds in lignin in Criegee-type mechanisms. Activated carbon-hydrogen bonds are fragmented in lignin side chains, as well as Cl carbons of {beta}-glycosides, by way of a 1,3 dipolar insertion forming a hydrotrioxide intermediate. Ozone also attacks carbohydrates at acetal oxygens, depolymerizing at the glycosidic bond. Unsaturated sites are ozonated before aliphatic sites resulting in a predominance of lignin reactions over carbohydrate reactions until lignin is substantially removed from the pulp. Important factors in the successful application of ozone bleaching include minimizing ozone decomposition and other secondary reactions, reducing exposure of cellulose to high concentrations of ozone and radicals, and promoting uniform exposure of ozone to lignin. The quantity of chlorinated organic compounds in effluents can be drastically reduced by replacing chlorine-based bleaching reagents with ozone; less organochlorine is formed and there can be greater recycle of bleach plant wastes back to the recovery cycle. Recycling of bleach plant waste also reduces total organic loading in the effluent. The toxicity of ozone filtrates is variable compared to conventional filtrates and depends on several parameters including bleaching conditions, biological treatment, and target organisms.

  5. Effects of long-term ambient ozone exposure on biomass and wood traits in poplar treated with ethylenediurea (EDU).

    PubMed

    Carriero, G; Emiliani, G; Giovannelli, A; Hoshika, Y; Manning, W J; Traversi, M L; Paoletti, E

    2015-11-01

    This is the longest continuous experiment where ethylenediurea (EDU) was used to protect plants from ozone (O3). Effects of long-term ambient O3 exposure (23 ppm h AOT40) on biomass of an O3 sensitive poplar clone (Oxford) were examined after six years from in-ground planting. Trees were irrigated with either water or 450 ppm EDU. Above (-51%) and below-ground biomass (-47%) was reduced by O3 although the effect was significant only for stem and coarse roots. Ambient O3 decreased diameter of the lower stem, and increased moisture content along the stem of not-protected plants (+16%). No other change in the physical wood structure was observed. A comparison with a previous assessment in the same experiment suggested that O3 effects on biomass partitioning to above-ground organs depend on the tree ontogenetic stage. The root/shoot ratios did not change, suggesting that previous short-term observations of reduced allocation to tree roots may be overestimated. PMID:26310976

  6. The impact of prolonged exposure on PTSD symptoms and associated psychopathology in people living with HIV: A randomized test of concept

    PubMed Central

    Pacella, Maria L.; Armelie, Aaron; Boarts, Jessica; Wagner, Glenn; Jones, Tracy; Feeny, Norah; Delahanty, Douglas L.

    2015-01-01

    People living with HIV (PLWH) report elevated levels of posttraumatic stress disorder symptoms (PTSS) and associated comorbidities. The present study tested the efficacy of prolonged exposure (PE) at reducing PTSS, depression, negative posttraumatic cognitions, and substance use in PLWH. Participants were randomly assigned to receive PE (n = 40) or to a weekly monitoring control group (n = 25). Assessments occurred at baseline, post-intervention and 3-months post-treatment. Following the 3-month assessment, controls were offered the intervention. All PE recipients (whether originally from the PE or control group) completed a 6-month assessment. Intent-to-treat mixed model repeated measures ANOVAs were conducted through 3-months post-treatment; within group analyses were conducted through 6-months. PE recipients reported fewer PTSS and negative posttraumatic cognitions and were more likely to achieve good end-state functioning; gains were maintained at 6-months. No between-group differences emerged for substance use. Overall, results support the efficacy of PE in PLWH. PMID:22012149

  7. Treating PTSD in Suicidal and Self-injuring Women with Borderline Personality Disorder: Development and Preliminary Evaluation of a Dialectical Behavior Therapy Prolonged Exposure Protocol

    PubMed Central

    Harned, Melanie S.; Korslund, Kathryn E.; Foa, Edna B.; Linehan, Marsha M.

    2012-01-01

    This study focused on the development and pilot testing of a protocol based on Prolonged Exposure (PE) that can be added to Dialectical Behavior Therapy (DBT) to treat PTSD in suicidal and self-injuring individuals with borderline personality disorder (BPD). Women with BPD, PTSD, and recent and/or imminent serious intentional self-injury (n=13) received one year of DBT with the DBT PE Protocol, plus three months of follow up assessment. The treatment was associated with significant reductions in PTSD, with the majority of patients no longer meeting criteria for PTSD at post-treatment (71.4% of DBT PE Protocol completers, 60.0% of the intent-to-treat sample). A minority of patients (27.3%) engaged in intentional self-injury during the study. Improvements were also found for suicidal ideation, dissociation, trauma-related guilt cognitions, shame, anxiety, depression, and social adjustment. There was no evidence that the DBT PE Protocol led to exacerbations of intentional self-injury urges or behaviors, PTSD, treatment dropout, or crisis service use. Overall, the results indicate that this integrated BPD and PTSD treatment is feasible to implement within one year of treatment, highly acceptable to patients and therapists, safe to administer, and shows promise as an effective intervention for PTSD in this complex and high-risk patient population. PMID:22503959

  8. [Secondary traumatization/trauma among employees in palliative care units--the products of prolonged repeated exposure to suffering and death].

    PubMed

    Samson, Tali; Shvartzman, Pesach

    2012-11-01

    The palliative care philosophy accepts the dying process as a natural phase in the life cycle and provides quality end of life care for terminal patients and their family members. Prolonged exposure to the physical symptoms and pain, as well as the psychological, spiritual, and existential suffering of the dying patient, may be fertile ground for the development of post-traumatic stress symptoms among palliative care teams. Work-related positive outcomes (such as compassion, satisfaction and meaning) and work-related negative outcomes (such as compassion fatigue, secondary traumatization and burnout) can exist side by side, and the unique balance between them will determine the quality of life of the worker. This review presents the current knowledge about the prevalence and causes of work-related stress outcomes among palliative care teams and measurement tools that are available. The literature review discusses secondary traumatization in palliative care teams and relevant messages for the development of treatment options, burnout prevention programs and support interventions for professionals who lead the care for terminal patients in Israel. PMID:23367727

  9. Mechanisms of Change in Cognitive Processing Therapy and Prolonged Exposure Therapy for PTSD: Preliminary Evidence for the Differential Effects of Hopelessness and Habituation

    PubMed Central

    Resick, Patricia A.

    2013-01-01

    The present study examined two potential mechanisms of change, hopelessness cognitions and habituation, in a randomized controlled trial of cognitive processing therapy (CPT) and prolonged exposure therapy (PE) for posttraumatic stress disorder (PTSD). Participants were 171 adult women with a current primary diagnosis of sexual assault related PTSD. The potential mechanisms were examined by evaluating the intraindividual change in hopelessness within the course of both treatments and subjective units distress (SUDS) ratings (a proxy for habituation) within the course of PE. The effects of intraindividual change in the proposed mechanisms were then examined on within-treatment changes in PTSD symptoms. Findings indicated that the participants assigned to the CPT treatment had significantly greater pre-post reductions in hopelessness than those assigned to PE and that the changes in hopelessness predicted changes in PTSD symptoms (R2 = .24). Intraindividual changes in SUDS ratings for participants in the PE treatment condition also predicted changes in PTSD symptoms and did so independently of the effect of changes in hopelessness. Future research should examine these mechanisms using more intensive methods of data collection that would permit the demonstration of temporality of change. PMID:24363472

  10. Prolonged Exposure Therapy for Combat-Related Posttraumatic Stress Disorder: An Examination of Treatment Effectiveness for Veterans of the Wars in Afghanistan and Iraq

    PubMed Central

    Tuerk, Peter W.; Yoder, Matthew; Grubaugh, Anouk; Myrick, Hugh; Hamner, Mark; Acierno, Ron

    2015-01-01

    The Veteran's Health Administration (VHA) has launched a large-scale initiative to promote prolonged exposure (PE) therapy, an evidence-based treatment for PTSD. While existing randomized controlled trials (RCTs) unambiguously support the efficacy of PE in civilian and some military populations, there is a need to better understand the course of treatment for combat Veterans of the current wars receiving PE in normative mental healthcare settings. The current study investigates 65 Veterans receiving care at an urban VA medical center. All Veterans were diagnosed with PTSD via a structured interview and treated with PE. Measures of PTSD and depression were collected pre- and post-treatment and every two sessions during treatment. Dependent means t-tests were used to estimate pre- and post-treatment d-type effect sizes. Additionally, hierarchical linear models (HLM) were used to investigate treatment effects over time, relationships between patient characteristics and outcomes, and to provide estimates of R2-type effect sizes. Results indicate that PE in regular VA mental healthcare contexts can be as effective as when implemented in carefully conducted RCTs. PMID:21131170

  11. Prolonged pregnancy.

    PubMed

    Hollis, Brian

    2002-04-01

    Prolonged pregnancy is defined as any pregnancy that lasts 294 days or more. It is now well recognized that prolonged pregnancy is associated with an increased risk of perinatal mortality and morbidity. It is these complications of pregnancy that have led obstetricians to adopt a policy of induction of labour before the onset of the post-term period. The induction of labour between 41 and 42 weeks is, however, a very crude strategy for reducing term and post-term stillbirth rates. Although the risk of fetal death is increased after 42 weeks, many more fetuses die in utero between 37 and 42 weeks than die in the post-term period. It appears that smaller term fetuses run a greater risk than their larger counterparts, and that current methods of antepartum assessment of the term fetus are still inadequate. It behoves us as obstetricians to improve our capabilities in identifying the compromised fetus at term. This review puts into perspective the most recent publications and highlights areas requiring further study. PMID:11914699

  12. Estimation of the respiratory tract burden resulting from a prolonged inhalation exposure to aerosols of DU, based on the U in a 24-h urine sample taken years after exposure.

    PubMed

    Valdés, M

    2014-12-01

    A procedure is presented to estimate the respiratory tract burden from a prolonged inhalation exposure to particulate matter of depleted uranium, in cases where the rate of deposition is an unknown function. The precise range of possible values is identified. The calculations are based on the amount of depleted uranium measured in a single 24-h urine sample. In order to present an example, a simplified pharmacokinetical model is introduced. The results presented in this article are valid for any pharmacokinetical model represented by homogeneous linear differential equations with constant coefficients and non-zero initial values, and that clearly includes the International Commission on Radiological Protection model. In fact, they are applicable to any monitorable quantity measured over a short period of time, a monitorable quantity with a kinetic that can be described using a structurally similar system of differential equations to one describing these pharmacokinetical models. PMID:24682012

  13. Prolonged Exposure of Primary Human Muscle Cells to Plasma Fatty Acids Associated with Obese Phenotype Induces Persistent Suppression of Muscle Mitochondrial ATP Synthase β Subunit.

    PubMed

    Tran, Lee; Hanavan, Paul D; Campbell, Latoya E; De Filippis, Elena; Lake, Douglas F; Coletta, Dawn K; Roust, Lori R; Mandarino, Lawrence J; Carroll, Chad C; Katsanos, Christos S

    2016-01-01

    Our previous studies show reduced abundance of the β-subunit of mitochondrial H+-ATP synthase (β-F1-ATPase) in skeletal muscle of obese individuals. The β-F1-ATPase forms the catalytic core of the ATP synthase, and it is critical for ATP production in muscle. The mechanism(s) impairing β-F1-ATPase metabolism in obesity, however, are not completely understood. First, we studied total muscle protein synthesis and the translation efficiency of β-F1-ATPase in obese (BMI, 36±1 kg/m2) and lean (BMI, 22±1 kg/m2) subjects. Both total protein synthesis (0.044±0.006 vs 0.066±0.006%·h-1) and translation efficiency of β-F1-ATPase (0.0031±0.0007 vs 0.0073±0.0004) were lower in muscle from the obese subjects when compared to the lean controls (P<0.05). We then evaluated these same responses in a primary cell culture model, and tested the specific hypothesis that circulating non-esterified fatty acids (NEFA) in obesity play a role in the responses observed in humans. The findings on total protein synthesis and translation efficiency of β-F1-ATPase in primary myotubes cultured from a lean subject, and after exposure to NEFA extracted from serum of an obese subject, were similar to those obtained in humans. Among candidate microRNAs (i.e., non-coding RNAs regulating gene expression), we identified miR-127-5p in preventing the production of β-F1-ATPase. Muscle expression of miR-127-5p negatively correlated with β-F1-ATPase protein translation efficiency in humans (r = - 0.6744; P<0.01), and could be modeled in vitro by prolonged exposure of primary myotubes derived from the lean subject to NEFA extracted from the obese subject. On the other hand, locked nucleic acid inhibitor synthesized to target miR-127-5p significantly increased β-F1-ATPase translation efficiency in myotubes (0.6±0.1 vs 1.3±0.3, in control vs exposure to 50 nM inhibitor; P<0.05). Our experiments implicate circulating NEFA in obesity in suppressing muscle protein metabolism, and establish

  14. Prolonged Exposure of Primary Human Muscle Cells to Plasma Fatty Acids Associated with Obese Phenotype Induces Persistent Suppression of Muscle Mitochondrial ATP Synthase β Subunit

    PubMed Central

    Tran, Lee; Hanavan, Paul D.; Campbell, Latoya E.; De Filippis, Elena; Lake, Douglas F.; Coletta, Dawn K.; Roust, Lori R.; Mandarino, Lawrence J.; Carroll, Chad C.; Katsanos, Christos S.

    2016-01-01

    Our previous studies show reduced abundance of the β-subunit of mitochondrial H+-ATP synthase (β-F1-ATPase) in skeletal muscle of obese individuals. The β-F1-ATPase forms the catalytic core of the ATP synthase, and it is critical for ATP production in muscle. The mechanism(s) impairing β-F1-ATPase metabolism in obesity, however, are not completely understood. First, we studied total muscle protein synthesis and the translation efficiency of β-F1-ATPase in obese (BMI, 36±1 kg/m2) and lean (BMI, 22±1 kg/m2) subjects. Both total protein synthesis (0.044±0.006 vs 0.066±0.006%·h-1) and translation efficiency of β-F1-ATPase (0.0031±0.0007 vs 0.0073±0.0004) were lower in muscle from the obese subjects when compared to the lean controls (P<0.05). We then evaluated these same responses in a primary cell culture model, and tested the specific hypothesis that circulating non-esterified fatty acids (NEFA) in obesity play a role in the responses observed in humans. The findings on total protein synthesis and translation efficiency of β-F1-ATPase in primary myotubes cultured from a lean subject, and after exposure to NEFA extracted from serum of an obese subject, were similar to those obtained in humans. Among candidate microRNAs (i.e., non-coding RNAs regulating gene expression), we identified miR-127-5p in preventing the production of β-F1-ATPase. Muscle expression of miR-127-5p negatively correlated with β-F1-ATPase protein translation efficiency in humans (r = – 0.6744; P<0.01), and could be modeled in vitro by prolonged exposure of primary myotubes derived from the lean subject to NEFA extracted from the obese subject. On the other hand, locked nucleic acid inhibitor synthesized to target miR-127-5p significantly increased β-F1-ATPase translation efficiency in myotubes (0.6±0.1 vs 1.3±0.3, in control vs exposure to 50 nM inhibitor; P<0.05). Our experiments implicate circulating NEFA in obesity in suppressing muscle protein metabolism, and establish

  15. Syntaxin 5 Overexpression and β-Amyloid 1–42 Accumulation in Endoplasmic Reticulum of Hippocampal Cells in Rat Brain Induced by Ozone Exposure

    PubMed Central

    Hernández-Zimbrón, Luis Fernando

    2016-01-01

    Oxidative stress is a risk factor for Alzheimer's disease and it is currently accepted that oxidative damage precedes the overproduction of A42 peptide. We have reported that ozone causes oxidative stress inducing neurodegeneration in the brain of rats. It is associated with A42 overproduction and intracellular accumulation in hippocampus. Organelles like mitochondria, intracellular membranes, and endoplasmic reticulum have been identified as sites of A42 production and accumulation affecting cellular metabolism. However whether ozone exposure induces overproduction and/or accumulation of A42 in endoplasmic reticulum has not been studied. We evaluated this effect in the endoplasmic reticulum of hippocampal cells of rats exposed chronically to low doses of ozone (0.25 ppm) at 7, 15, 30, 60, and 90 days. The effect of the presence of A42 in endoplasmic reticulum was analyzed evaluating the expression of the chaperone Syntaxin 5. Our results show an accumulation of A42 peptide in this organelle. It was observed by immunofluorescence and by WB in endoplasmic fractions from hippocampal cells of rats at 60 and 90 days of treatment. Significant overexpression of the chaperone Syntaxin 5 at 60 and 90 days of treatment was observed (⁎P < 0.05). These results indicate that the exposure to environmental pollutants could be involved as a risk factor for neurodegenerative processes. PMID:27366738

  16. Syntaxin 5 Overexpression and β-Amyloid 1-42 Accumulation in Endoplasmic Reticulum of Hippocampal Cells in Rat Brain Induced by Ozone Exposure.

    PubMed

    Hernández-Zimbrón, Luis Fernando; Rivas-Arancibia, Selva

    2016-01-01

    Oxidative stress is a risk factor for Alzheimer's disease and it is currently accepted that oxidative damage precedes the overproduction of A42 peptide. We have reported that ozone causes oxidative stress inducing neurodegeneration in the brain of rats. It is associated with A42 overproduction and intracellular accumulation in hippocampus. Organelles like mitochondria,