422 research outputs found

    Allergen-specific immunotherapy: an update on immunological mechanisms of action

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    Specific immunotherapy (SIT) is the only treatment able to modify the natural history of the allergic subjects. Several aspects of the immunopathological response modified by SIT have been investigated; the first parameter historically studied was the production of allergen-specific antibodies. An increase of allergen-specific IgG4 and a decrease of IgE appear after SIT. A shift from Th2-polarized immune response toward Th1-oriented pattern has been reported after SIT. More recently, a crucial role for a subpopulation of T cells has been evidenced: T regulatory cells (Treg). Allergic patients have a defect of Tregs. SIT is able of inducing a specific Treg response. Sublingual immunotherapy is an alternative route of administration for SIT. Recent evidence shows that SLIT is also able of inducing a Treg response as detected by IL- 10 production

    Tropical biomass burning smoke plume size, shape, reflectance, and age based on 2001–2009 MISR imagery of Borneo

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    Land clearing for crops, plantations and grazing results in anthropogenic burning of tropical forests and peatlands in Indonesia, where images of fire-generated aerosol plumes have been captured by the Multi-angle Imaging SpectroRadiometer (MISR) since 2001. Here we analyze the size, shape, optical properties, and age of distinct fire-generated plumes in Borneo from 2001–2009. The local MISR overpass at 10:30 a.m. misses the afternoon peak of Borneo fire emissions, and may preferentially sample longer plumes from persistent fires burning overnight. Typically the smoke flows with the prevailing southeasterly surface winds at 3–4 m s<sup>−1</sup>, and forms ovoid plumes whose mean length, height, and cross-plume width are 41 km, 708 m, and 27% of the plume length, respectively. 50% of these plumes have length between 24 and 50 km, height between 523 and 993 m and width between 18% and 30% of plume length. Length and cross-plume width are lognormally distributed, while height follows a normal distribution. Borneo smoke plume heights are similar to previously reported plume heights, yet Borneo plumes are on average nearly three times longer than previously studied plumes. This could be due to sampling or to more persistent fires and greater fuel loads in peatlands than in other tropical forests. Plume area (median 169 km<sup>2</sup>, with 25th and 75th percentiles at 99 km<sup>2</sup> and 304 km<sup>2</sup>, respectively) varies exponentially with length, though for most plumes a linear relation provides a good approximation. The MISR-estimated plume optical properties involve greater uncertainties than the geometric properties, and show patterns consistent with smoke aging. Optical depth increases by 15–25% in the down-plume direction, consistent with hygroscopic growth and nucleation overwhelming the effects of particle dispersion. Both particle single-scattering albedo and top-of-atmosphere reflectance peak about halfway down-plume, at values about 3% and 10% greater than at the origin, respectively. The initially oblong plumes become brighter and more circular with time, increasingly resembling smoke clouds. Wind speed does not explain a significant fraction of the variation in plume geometry. We provide a parameterization of plume shape that can help atmospheric models estimate the effects of plumes on weather, climate, and air quality. Plume age, the age of smoke furthest down-plume, is lognormally distributed with a median of 2.8 h (25th and 75th percentiles at 1.3 h and 4.0 h), different from the median ages reported in other studies. Intercomparison of our results with previous studies shows that the shape, height, optical depth, and lifetime characteristics reported for tropical biomass burning plumes on three continents are dissimilar and distinct from the same characteristics of non-tropical wildfire plumes

    Impact of allergic rhinitis on asthma: effects on bronchodilation testing

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    A remarkable relationship exists between the upper and lower airways. Bronchial obstruction is a paramount feature of asthma, and its reversibility is considered a main step in asthma diagnosis

    Do biomass burning aerosols intensify drought in equatorial Asia during El Niño?

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    During El Niño years, fires in tropical forests and peatlands in equatorial Asia create large regional smoke clouds. We characterized the sensitivity of these clouds to regional drought, and we investigated their effects on climate by using an atmospheric general circulation model. Satellite observations during 2000–2006 indicated that El Niño-induced regional drought led to increases in fire emissions and, consequently, increases in aerosol optical depths over Sumatra, Borneo and the surrounding ocean. Next, we used the Community Atmosphere Model (CAM) to investigate how climate responded to this forcing. We conducted two 30 year simulations in which monthly fire emissions were prescribed for either a high (El Niño, 1997) or low (La Niña, 2000) fire year using a satellite-derived time series of fire emissions. Our simulations included the direct and semi-direct effects of aerosols on the radiation budget within the model. We assessed the radiative and climate effects of anthropogenic fire by analyzing the differences between the high and low fire simulations. Fire aerosols reduced net shortwave radiation at the surface during August–October by 19.1±12.9 W m<sup>−2</sup> (10%) in a region that encompassed most of Sumatra and Borneo (90° E–120° E, 5° S–5° N). The reductions in net shortwave radiation cooled sea surface temperatures (SSTs) and land surface temperatures by 0.5±0.3 and 0.4±0.2 °C during these months. Tropospheric heating from black carbon (BC) absorption averaged 20.5±9.3 W m<sup>−2</sup> and was balanced by a reduction in latent heating. The combination of decreased SSTs and increased atmospheric heating reduced regional precipitation by 0.9±0.6 mm d<sup>−1</sup> (10%). The vulnerability of ecosystems to fire was enhanced because the decreases in precipitation exceeded those for evapotranspiration. Together, the satellite and modeling results imply a possible positive feedback loop in which anthropogenic burning in the region intensifies drought stress during El Niño

    A Global Analysis of Wildfire Smoke Injection Heights Derived from Space-Based Multi-Angle Imaging

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    We present an analysis of over 23,000 globally distributed wildfire smoke plume injection heights derived from Multi-angle Imaging SpectroRadiometer (MISR) space-based, multi-angle stereo imaging. Both pixel-weighted and aerosol optical depth (AOD)-weighted results are given, stratified by region, biome, and month or season. This offers an observational resource for assessing first-principle plume-rise modelling, and can provide some constraints on smoke dispersion modelling for climate and air quality applications. The main limitation is that the satellite is in a sun-synchronous orbit, crossing the equator at about 10:30 a.m. local time on the day side. Overall, plumes occur preferentially during the northern mid-latitude burning season, and the vast majority inject smoke near-surface. However, the heavily forested regions of North and South America, and Africa produce the most frequent elevated plumes and the highest AOD values; some smoke is injected to altitudes well above 2 km in nearly all regions and biomes. Planetary boundary layer (PBL) versus free troposphere injection is a critical factor affecting smoke dispersion and environmental impact, and is affected by both the smoke injection height and the PBL height; an example assessment is made here, but constraining the PBL height for this application warrants further work

    Bronchial hyperreactivity and spirometric impairment in patients with allergic rhinitis.

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    Background: The Link between allergic rhinitis and asthma is well known. Bronchial hyperreactivity (BHR) may be present in rhinitics. The present study is aimed at evaluating a large group of subjects suffering from allergic rhinitis alone to investigate the presence of spirometric impairment and BHR both during and outside the pollen season. Methods: 360 rhinitics (subdivided in 3 groups: seasonal, SAR, perennial, PAR, and polysensitized, PolysR) were investigated by spirometry and methacholine challenge. Results: There was a significant seasonal difference concerning the number of rhinitics with impaired FEV1 (p<0.01 for SAR, p<0.02 for PAR, and p<0.03 for PolysR) and FEF25-75 (p<0.05 for SAR, p<0.03 for PAR, and p<0.05 for PolysR) as well as with BHR (p<0.05 for SAR and p<0.03 for PAR). Conclusions: This study evidences that an impairment of spirometric parameters and BHR may be observed in patients with allergic rhinitis alone. Thus, careful evaluation of lower airways should be performed in patients with allergic rhinitis alone

    Allergy and covid-19

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    The first cases of as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have been reported in Wuhan, China in December 2019. The World Health Organization declared the global pandemic in March 2020. Coronavirus disease 2019 (COVID-19) showed high rates of mortality in the adult popula-tion, whereas a mild course was observed in childhood. Allergic diseases, characterized by a type-2 polariza-tion of the immune system, were considered one of the major risk factor of severe COVID-19. Large amounts of clinical data and expert opinions have been collected since the pandemic outbreak. This review summarizes the latest insights on COVID-19 and allergy. (www.actabiomedica.it)

    Use of remdesivir in children with covid-19 infection: A quick narrative review

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    SARS-CoV-2 infection has a severe course in a small percentage of children. Remdesivir has shown promising results in reducing hospitalisation time in adults, but data on mortality rate are conflicting and few studies are available on its use use in antivirals in children. We performed a quick narrative review of the available literature data regarding the usage of remdesivir in children and neonates. In children, remdesivir showed good safety profile, however bradicardia events have been reported in children. Remdesivir is cur-rently recommended by several guidelines in some subgroups of children with severe COVID-19, and should also be considered in critically ill patients, always in the context of the overall clinical picture and drug avail-ability. (www.actabiomedica.it)

    Insights into past ocean proxies from micron-scale mapping of sulfur species in carbonates

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    Laboratory work and analyses were supported by a Steve Fossett Fellowship awarded to Rose; a U.S. Department of Energy (DOE) Biological and Environmental Research grant (DE-SC0014613), U.S. National Science Foundation (NSF) grants (EAR-0951509, 1229370), an Agouron Institute (California, USA) grant, a Packard (The David and Lucile Packard Foundation, California, USA) Fellowship, and a Hanse-Wissenschaftskolleg (Germany) Fellowship awarded to Fike; and an NSF Career Grant (EAR-1056480) awarded to Catalano. Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory (California, USA), is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under contract DE-AC02-76SF00515. GeoSoilEnviroCARS is supported by the NSF–Earth Sciences (EAR-1634415) and DOE–GeoSciences (DE-FG02-94ER14466).Geological reconstructions of global ocean chemistry and atmospheric oxygen concentrations over Earth history commonly rely on the abundance and stable isotopic composition (δ34S) of sulfur-bearing compounds. Carbonate-associated sulfate (CAS), sulfate bound within a calcium carbonate mineral matrix, is among the most commonly interrogated sulfur mineral phases. However, recent work has revealed variability in δ34SCAS values that cannot be explained by evolution of the marine sulfate reservoir, challenging the common interpretation that CAS is inherently a high-fidelity record of seawater sulfate. To investigate the source of this inconsistency, we used X-ray spectromicroscopy to map the micron-scale distribution of S-bearing sedimentary phases in Ordovician-aged (ca. 444 Ma) shallow marine carbonates from Anticosti Island, Québec, Canada. Clear differences in the abundance of CAS are observed between cements and fossils, suggesting that variance in bulk-rock data could be a consequence of component mixing and that coupled synchrotron-petrographic screening can identify the carbonate components that are most likely to retain primary CAS. Furthermore, we observe multiple, distinct forms of sulfate (both inorganic and organic). Differences in these forms among fossil clades could provide new insights into biomineralization mechanisms in extinct organisms.PostprintPeer reviewe

    Impact of children's respiratory allergies on caregivers.

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    Background. Despite the great attention that has been paid to HRQoL in children with respiratory allergy, few studies have addressed this aspect in relation to caregivers. The aim of our study was to evaluate the impact of childhood respiratory allergies on caregivers by means of a new method. Methods. 119 parents of children suffering from allergies (75 suffering from asthma and 44 suffering from rhinitis) were recruited from three Italian Allergy Units. Parents were asked to complete the Disease Impact On Caregiver (DIOC), a new non disease specific questionnaire, validated on the Italian population. The questionnaire consists of 31 items grouped in four factors (Performance, Personal gratification, Psychophysical endurance, Socio-emotional domain) and covers the life aspects that could be affected by the assistance duties towards an ill family member. Results. Child's asthma resulted to have a worse impact on many aspects of a parents' life than rhinitis. Differences resulted to be statistically significant in 19 aspects out of the 31 assessed. The worse impact of asthma versus rhinitis was confirmed in the following domains: Performance (24.0±18.2 vs 11.5±17.8), Personal gratification (26.3±20.5 vs 12.1±16.5) and Psychophysical endurance (35.0±24.8 vs 18.8±21.7). In the Socio-emotional domain no difference emerged. Conclusions. Compared to parents of rhinitics, parents of asthmatic children appear to be more compromised in their resistance to stress, mood, emotional stability, amount of spare time and leisure activities. Our results suggest the need of giving the due attention to these problems both in clinical practice and in research, in order to avoid possible interferences of the caregiver's distress in the optimization of treatment outcome
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