143 resultados para Callichirus major


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background

Grass pollen allergens are the most important cause of hay fever and allergic asthma during summer in cool temperate climates. Pollen counts provide a guide to hay fever sufferers. However, grass pollen, because of its size, has a low probability of entering the lower airways to trigger asthma. Yet, grass pollen allergens are known to be associated with atmospheric respirable particles.
Objective

We aimed (1) to determine the concentration of group 5 major allergens in (a) pollen grains of clinically important grass species and (b) atmospheric particles (respirable and nonrespirable) and (2) to compare the atmospheric allergen load with clinical data to assess different risk factors for asthma and hay fever.
Methods

We have performed a continuous 24 h sampling of atmospheric particles greater and lower than 7.2 μm in diameter during the grass pollen season of 1996 and 1997 (17 October 1996–16 January 1997) by means of a high volume cascade impactor at a height of about 15 m above ground in Melbourne. Using Western analysis, we assessed the reactivity of major timothy grass allergen Phl p 5 specific monoclonal antibody (MoAb) against selected pollen extracts. A MoAb-based ELISA was then employed to quantify Phl p 5 and cross-reactive allergens in pollen extracts and atmospheric particles larger and smaller than 7.2 μm.
Results

Phl p 5-specific MoAb detected group 5 allergens in tested grass pollen extracts, indicating that the ELISA employed here determines total group 5 allergen concentrations. On average, 0.05 ng of group 5 allergens were detectable per grass pollen grain. Atmospheric group 5 allergen concentrations in particles > 7.2 μm were significantly correlated with grass pollen counts (rs = 0.842, P < 0.001). On dry days, 37% of the total group 5 allergen load, whereas upon rainfall, 57% of the total load was detected in respirable particles. After rainfall, the number of starch granule equivalents increased up to 10-fold; starch granule equivalent is defined as a hypothetical potential number of airborne starch granules based on known pollen count data. This indicates that rainfall tended to wash out large particles and contributed to an increase in respirable particles containing group 5 allergens by bursting of pollen grains. Four day running means of group 5 allergens in respirable particles and of asthma attendances (delayed by 2 days) were shown to be significantly correlated (P < 0.001).
Conclusion

Here we present, for the first time, an estimation of the total group 5 allergen content in respirable and nonrespirable particles in the atmosphere of Melbourne. These results highlight the different environmental risk factors for hay fever and allergic asthma in patients, as on days of rainfall following high grass pollen count, the risk for asthma sufferers is far greater than on days of high pollen count with no associated rainfall. Moreover, rainfall may also contribute to the release of allergens from fungal spores and, along with the release of free allergen molecules from pollen grains, may be able to interact with other particles such as pollutants (i.e. diesel exhaust carbon particles) to trigger allergic asthma.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: Birch-pollen allergens are an important cause of early spring hay fever and allergic asthma. Recently, we reported a mechanism for the release of respirable allergenic particles from birch pollen containing the major allergen Bet v 1. In this study, we aimed to assess the immunologic significance of the released Bet v 1-containing starch granules in the environment.

Methods: A two-site monoclonal antibody-based assay (ELISA) was employed to quantitate Bet v 1 in high-volume air sampler filter extracts, and immunogold-labelling was used on sections of these extracts to localize Bet v 1. Immunoblot analyses were performed with pooled sera from patients sensitive to birch pollen.

Results: Atmospheric starch granules contained Bet v 1, and the concentration increased upon light rainfall. Sera from patients allergic to birch allergens recognized extracts from isolated starch granules.

Conclusions: The clinical implications of these findings are that starch granules released from birch pollen are potentially able to trigger allergic asthmatic reactions to Bet v 1, since the allergen occurs in respirable particles. Thus, clinicians can advise asthma patients to remain indoors on days of light rainfall during the birch-pollen season to avoid high levels of allergen exposure.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background Grass pollen allergens are known to be present in the atmosphere in a range of particle sizes from whole pollen grains (approx. 20 to 55 μim in diameter) to smaller size fractions < 2.5 μ (fine particles, PM2.5). These latter particles are within the respirable range and include allergen-containing starch granules released from within the grains into the atmosphere when grass pollen ruptures in rainfall and are associated with epidemics of thunderstorm asthma during the grass pollen season. The question arises whether grass pollen allergens can interact with other sources of fine particles, particularly those present during episodes of air pollution.

Objective We propose the hypothesis that free grass pollen allergen molecules, derived from dead or burst grains and dispersed in microdroplets of water in aerosols, can bind to fine particles in polluted air.

Methods We used diesel exhaust carbon particles (DECP) derived from the exhaust of a stationary diesel engine, natural highly purified Lol p 1, immunogold labelling with specific monoclonal antibodies and a high voltage transmission electron -microscopic imaging technique

Results DECP are visualized as small carbon spheres, each 30–60 nm in diameter, forming fractal aggregates about 1–2μ in diameter. Here we test our hypothesis and show by in vitro experiments that the major grass pollen allergen, Lol p I. binds to one defined class of fine particles, DECP.

Conclusion DECP are in the respirable size range, can bind to the major grass pollen allergen Lol p I under in vitro conditions and represent a possible mechanism by which allergens can become concentrated in polluted air and thus trigger attacks of asthma.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Purpose – This paper aims to examine the tendencies of sustainability reporting by major commercial banks in Bangladesh in comparison with global sustainability reporting indicators outlined in the GRI framework together with banks' predilection toward reporting 16 GRI financial service sector (FSS) specific performance indicators.

Design/methodology/approach – Based on the GRI G3 guidelines, the paper investigated banks' reporting in five broad areas of sustainability, such as environment, labour practices and decent works, product responsibility, human rights and society. The 2008/2009 annual reports of 12 major commercial banks listed on Dhaka stock exchange were analysed and coded using a content-based technique.

Findings – The results show that information on society is addressed most extensively with regard to extent of reporting. This is followed by the disclosures prepared on decent works and labour practices and environmental issues. Furthermore, the disclosures of product responsibility information and the information for human rights are rather scarce in banks' reporting; on the subject of FSS-specific disclosures, only seven items out of 16 are disclosed by all sample banks.

Research limitations/implications – The findings of the study indicate that Bangladeshi commercial banks' social disclosures could develop in this style to become more holistic and over time (in association with the country's central bank involvement) to resemble a type of structured reporting to the point where they are properly labelled per se.

Originality/value – The study contributes to the social disclosure literature, in particular in a developing countries banking sector context, seeing as it disseminates evidence of the standing on social disclosures practices at the level of GRI with developing countries' banks data.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Organisational RestructuringLeading higher education organisational restructuring is not an easy task. It involves various degree of engagement, decision making and strategic alliances to make the change a success. Research has shown that organisational restructuring has impact on individuals of the organization and vice versa. Studies have shown that imposed change may create negative emotions such as fear of losing something important, anger and anxiety. On the contrary, planned change is accompanied by excitement and hope. Thus, the call for best practices in leading successful organizational change is greater than ever. Factors such as the fundamental characters and practices of higher education, as well as the presence of various human factors (academics and administrative) need to be taken into account. This paper presents the preliminary findings of a case study on organisational restructuring at a higher education institution in Australia. The restructuring in focus involves the amalgamation of two university faculties into one. This paper seeks to present the experiences and life accounts of faculty members with regards to leadership during the amalgamation process. Interviews were carried out with both the academic and administrative staff. Analysis of the interviews found a variation of views on leadership at different levels of the organisation, the emergence of leadership in times of crisis, the gap between the academics and administrative as well as the importance of organisational members to make the restructuring a success. The paper ends with useful suggestions for leaders and their role towards leading successful change in today’s complex higher education scenario.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: This paper aims to present an overview of screening and safety considerations for the treatment of clinical depressive disorders and make recommendations for safety monitoring.
Method: Data were sourced by a literature search using MEDLINE and a manual search of scientific journals to identify relevant articles. Draft guidelines were prepared and serially revised in an iterative manner until all co-authors gave final approval of content.
Results: Screening and monitoring can detect medical causes of depression. Specific adverse effects associated with antidepressant treatments may be reduced or identified earlier by baseline screening and agent-specific monitoring after commencing treatment.
Conclusion: The adoption of safety monitoring guidelines when treating clinical depression is likely to improve overall physical health status and treatment outcome. It is important to implement these guidelines in the routine management of clinical depression.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Risk analysis is one of the critical functions of the risk management process. It relies on a detailed understanding of risks and their possible implications. Construction projects, because of their large and complex nature, are plagued by a variety of risks which must be considered and responded to in order to ensure project success. This study conducts an extensive comparative analysis of major quantitative risk analysis techniques in the construction industry. The techniques discussed and comparatively analyzed in this report include: Programme Evaluation and Review Technique (PERT), Judgmental Risk Analysis Process (JRAP), Estimating Using Risk Analysis (ERA), Monte Carlo Simulation technique, Computer Aided Simulation for Project Appraisal and Review (CASPAR), Failure Modes and Effects Analysis technique (FMEA) and Advanced Programmatic Risk Analysis and Management model (APRAM). The findings highlight the fact that each risk analysis technique addresses risks in any or all of the following areas – schedule risks, budget risks or technical risks. Through comparative analysis, it has been revealed that a majority of risk analysis techniques focus on schedule or budget risks. Very little has been documented in terms of technical risk analysis techniques. In an era where clients are demanding and expecting higher quality projects and finishes, project managers must endeavor to invest time and resources to ensure that the few existing technical risk analysis techniques are developed and further refined, and that new technical risk analysis techniques are developed to suit the current construction industries requirements.