Comparison between Airway Responses to High versus Low Molecular Weight Compounds in Occupational Asthma

Occupational asthma (OA) is a heterogeneous disease, and the characteristics of the sensitizer responsible for OA may induce different clinical, functional, and biological manifestations. We examined the characteristics of 74 patients with OA induced by low molecular weight compounds (LMWC) or by high molecular weight compounds (HMWC) and diagnosed by specific inhalation challenge (SIC). Patients with OA induced by LMWC had a longer occupational exposure before the beginning of symptoms, a lower sputum eosinophilia, and a higher prevalence of late airway response (LAR), in comparison with patients with OA induced by HMWC. Pulmonary function tended to be poorer and atopy tended to be less frequent in LMWC-induced OA than in HMWC-induced OA. These data confirm and extend previous observations showing that the characteristics of the specific sensitizer inducing OA may determine different clinical, functional, and biological features, probably related to the difference pathogenetic mechanisms underlying these different types of OA

Effects of systemic glucocorticosteroids on peripheral neutrophil functions in asthmatic subjects: an ex vivo study

In 21 asthmatic subjects, several functions of isolated peripheral neutrophils (chemokinesis and chemotaxis toward 10% E. coli; superoxide anion generation after PMA; leukotriene B4 (LTB4) release from whole blood and isolated neutrophtls, before and after different stimuli) were evaluated during an acute exacerbation of asthma, and after 14 – 54 days of treatment with systemic glucocorticosteroids (GCS). During acute exacerbation, superoxide anion generation was higher in asthmatics than in eleven normal subjects (39.2 ± 14.1 vs. 25.2 ± 7.3 nmol, p < 0.05); there was a significant correlation between FEV1 (% of predicted) and neutrophil chemotaxis (r = −0.52, p = 0.04). After treatment, there was no significant change in all neutrophil functions, except for a decrease in neutrophil chemotaxis in subjects who showed an FEV1 increase > 20% after GCS treatment (from 131 ± 18 to 117 ± 21 μm, p = 0.005). Chemokinesis sicantly decreased in all subjects, and the changes significantly correlated with an arbitrary score of the total administered dose of GCS (r = 0.57, p < 0.05). These data suggest that neutrophil activation plays a minor role in asthma, and that treatment with GCS is not able to modify most functions of peripheral neutrophils in asthmatic subjects; chemotaxis seems to be related only to the severity of the asthma and it could reflect the improvement of the disease

Prenatal exposures and exposomics of asthma

This review examines the causal investigation of preclinical development of childhood asthma using exposomic tools. We examine the current state of knowledge regarding early-life exposure to non-biogenic indoor air pollution and the developmental modulation of the immune system. We examine how metabolomics technologies could aid not only in the biomarker identification of a particular asthma phenotype, but also the mechanisms underlying the immunopathologic process. Within such a framework, we propose alternate components of exposomic investigation of asthma in which, the exposome represents a reiterative investigative process of targeted biomarker identification, validation through computational systems biology and physical sampling of environmental medi

Differential responses of zooplankton assemblages to environmental variation in temporary and permanent ponds

Permanent and temporary wetlands in Mediterranean shrublands represent unique repositories of biodiversity, which are increasingly threatened by human-induced habitat loss. The zooplankton of a permanent (P1) and a temporary pond (T35) in the Natural Reserve of Castelporziano, a rare residual stretch of such a shrubland in Central Italy (Latium), was investigated to: (1) expand and deepen knowledge of these endangered freshwater habitats, which represent a crucial component of Mediterranean biodiversity; (2) identify environmental controls regulating the development of zooplankton communities of each environment; and (3) highlight differences in the adaptive responses of the zooplankton community in relation to the different ecological conditions experienced by permanent and temporary habitats. Despite summer desiccation in T35, the two ponds exhibited a relative homogeneity in hydrological and physico-chemical dynamics. Zooplankton assemblages contained 41 total taxa, of which 32 were found in P1 and 28 in T35. Out of the 41 taxa identified, 22 (> 50%) were exclusively present in one of the two ponds. On a yearly basis, the community dynamics of P1 seemed to be conditioned by physical and chemical factors and by hydrological cycle characteristics, while the community of T35 responded to algal blooms, food competition and predator/prey equilibria rather than correlating to abiotic factors. The main differences amongst zooplankton assemblages were observed over short time scales and occurred both within and between seasons, highlighting the role of some structural taxa that dominated the average composition of the community throughout the year, and the importance of "quick-response" taxa in determining the short-term composition and structure variation of pond zooplankton. A year-round cyclic community succession peculiar to each pond is described

Long term monitoring of astatic water bodies. Microcrustaceans as indicators of hydroperiod length in ponds and pools

Microcrustacean assemblages (Cladocera and Copepoda) from astatic ponds and pools of Castelporziano Presidential Estate were analysed to evaluate their role as indicators of functional variations related to the wet phase duration. The cladoceran and copepod fauna of the Estate (42 species) is very well known; rarefaction curves demonstrated that a percentage between 91 and 95% of total species richness was collected so far. Samples from a subset of 22 water bodies classified as permanent or temporary (based on observations over two decades, 1989-2001) were analysed. As a whole, 36 species of microcrustaceans (22 cladocerans and 14 copepods) were present in the 22 sampling sites. Hierarchical clustering allowed a clear distinction between temporary and permanent water bodies. Principal coordinate analysis (PCoA) provided a good separation of the two major hydroperiod groups along the first axis, which explained over 41.3% of total variation. The separation, tested by means of ANOSIM, showed to be significant, while no correlation emerged among PCoA axes and hydrogeological setting (i.e. hydrogeochemistry). The correlation between species and the first PCoA axis evidenced some possible biological indicators of hydrological changes: the cyclopoid copepods Macrocyclops albidus and Eucyclops serrulatus, which have no resting stages, in permanent ponds, accompanied by the calanoid copepod Eudiaptomus padanus etruscus and the cladocerans Ceriodaphnia reticulata, Scapholeberis ramneri and Coronella rectangula which are present in permanent and semi-permanent ponds; the cladoceran Daphnia chevreuxi and the calanoid copepods Diaptomus serbicus, Hemidiaptomus gurneyi and Mixodiaptomus kupelwieseri were exclusive of temporary ponds with short hydroperiod (less than six months). Finally, temporary water bodies hosted a mean species richness (13.7 species) higher than permanent ones (10.3), and the difference was statistically significant (p<0.05). Our results highlight that (1) cladocerans and copepods possess a high power in discriminating ponds with different wet phase duration, showing to be very good bioindicators; (2) small astatic water bodies play an important role in biodiversity conservation, as they host high percentages of species distributed in wider areas, besides of species exclusive of these habitats, and exhibit a higher alpha-diversity than permanent ponds; (3) hydroperiod appears to be the main driving force in characterizing microcrustacean assemblages in astatic ponds