内蒙古呼和浩特地区空气中致敏花粉的探讨

花粉中含有蛋白质、多糖类物质,属于外源性抗原,是引起呼吸道及其它变态反应病的重要致敏原。花粉症患者,占内蒙医学院附属医院变态反应门诊量的2—5%。为了有效的防治,必须了解空气中的致敏花粉种属及其数量,     

城市中的花粉致敏植物及其影响因素

大量致敏花粉飘散于空气中会引发花粉症,严重危害人体健康。由于不当的城市绿地建设使得花粉致敏植物在城市中大量聚集,加之城市热岛效应和交通污染等多方面的因素,使得城市中花粉症患者数量激增。综述了花粉致敏植物的种类、物候特征和影响因素提出了控制花粉致敏植物的建议;总结了目前花粉致敏植物研究中应进一步关注的问题,旨在为改善城市空气质量,建设合理绿化环境提供科学依据。     

花粉惹出的烦恼

“春……阿嚏……季里来百花香”,春风送暖,春意盎然,在这春花渐欲迷人眼的人间四月天里,恼人的花粉症也不期而至。什么是花粉症花粉症又叫花粉过敏,是指由花粉引起的呼吸道及眼部等器官的过敏表现。这是特异性个体对花粉的一种过敏反应。花粉通常是直径20～30μm的颗粒,在自然界,它是一种主要的致敏原。每年春季,枸树、蓖麻、地肤、法国梧桐,还有松树、橡树、枫树、桦树等各种植物的花     

北京主要气传致敏花粉年浓度峰值日期预测

花粉是我国北方引发过敏性鼻炎最主要过敏原,花粉症发病期与花粉浓度高峰期吻合。基于北京地区2012至2020年花粉季多站、逐日分类花粉浓度观测数据分析,得出北京地区花粉浓度在3月上旬至5月中旬(可进一步划分为3月中旬至4月上旬和4月下旬至5月上旬两个高峰期)和8月中旬至9月中旬分别存在两个高峰期,第一个高峰期内优势致敏花粉种类为柏科、杨柳科和松科,第二个高峰期内优势致敏花粉种类为桑科、菊科蒿属和藜科。根据优势致敏花粉年浓度峰值日期观测数据,使用与花粉采样站点位置相匹配的逐日气象观测数据累积值,基于作物模型概念和模糊逻辑原理建立了北京地区主要气传致敏花粉年浓度峰值日期预测模型。经检验,柏科、杨柳科、松科、桑科、菊科蒿属和藜科花粉模型预测准确率分别为87.8%、80.0%、64.4%、86.7%、78.8%和81.8%。基于北京地区主要气传致敏花粉年浓度峰值日期预测模型可为本地花粉症防治提供理论参考。     

武昌地区豚草花粉症研究

豚草原产北美洲,为一年生草本,高达200cm,属风媒植物,是北美地区引起花粉症的主要致敏植物"'。自40年代进入我国后,迅速蔓延。为探明武昌地区豚草的分布及其花粉在空气中的污染情况,我们于19g4年5月1日～1995年4月30日对本地区豚草花粉及其致敏性进行了调查、研究。1材料     

沈阳地区豚草及其花粉的调查

豚草(Ambrosia L.)花粉是北美地区的主要致敏花粉,可引起过敏性鼻炎、支气管哮喘等变态反应性疾病,国外称之为豚草花粉症。此症在美国、加拿大以及阿根廷等国的发病率达3—4%。据报道,加拿大约有80万人,美国约有1400万人受此花粉症之害,已成为引人注意的社会卫生问题。几年来,我们在变态反应临床工作中,     

水稻(Oryzasativa L.)潜在内源性致敏原的生物信息学筛选与分析

食物中的蛋白质是最常见的食入性致敏原。为了对水稻中的内源性致敏原有一个全面的认识和了解,本研究利用全序列比对的方法比较了水稻蛋白与已知致敏原之间的序列相似性,获得了水稻潜在致敏原,并对其保守结构域、分子功能、系统发育和染色体分布进行了分析和描述。结果一共发现了122个水稻潜在致敏蛋白,其中包括了22个已被数据库收录的水稻致敏原;保守结构域分析显示它们分别属于37个蛋白家族,其中的HATPase_c_3(Histidine kinase-,DNA gyrase B-,and HSP90-like ATPase,PF13589)结构域未在已知致敏原中发现;系统发育分析则分别揭示了水稻Prolamin蛋白超家族和Dna K蛋白家族的多样性;而且潜在致敏蛋白在水稻染色体上有成簇状分布的趋势。     

城市花粉致敏植物种类构成、分布与潜在危害评估——以深圳市为例

气传致敏花粉会引发过敏症,且可通过每年在花粉季的反复接触逐渐加重,危害人体健康,严重时甚至危害生命。花粉致敏植物在城市中被广泛引种栽培,导致城市花粉症患者数量激增。以深圳市为案例,基于建成区600个样地的实地调查数据,分析花粉致敏植物的种类构成与时空分布,通过构建花粉浓度及花粉致敏危害潜力计算公式,评估花粉致敏危害潜力及其分布特点。结果显示：①调查记录到深圳市建成区花粉致敏植物46科92属186种,其中外来种占43.37%,其中美洲、亚洲和大洋洲来源占国外外来种的81.00%。花粉致敏植物种数以公园绿地最多,达126种。植物花粉致敏等级以Ⅰ级为主,达154种。②花粉致敏植物的盛花期为春夏季,占全年累计开花种数的65.02%。最高峰出现在8月,开花种数达92种。 ③花粉浓度潜力最高值也出现在8月,占全年总值的12.13%。豆科和禾本科植物贡献比例较大,分别占乔木和草本总值的40.86%和64.13%。龙岗区花粉浓度潜力占比较高,占各季花粉量的26.06%-29.42%。④冬春两季各样地花粉致敏危害等级均不高,但夏秋季有些样地达到二级重度危害。罗湖区调查样地全年花粉致敏危害等级均较低,光明区在春夏秋季致敏危害等级皆较高。高危害等级样地主要出现在附属绿地及公园绿地。⑤花粉致敏植物防控措施情景模拟结果,去除主要花粉致敏植物种类比降低所有花粉致敏植物的花粉浓度潜力更有效。本研究为城市花粉致敏植物的管理、规划、养护和研究提供参考。     

北京城区气传花粉季节分布特征

研究北京城区气传花粉种类、数量及季节消长规律,为防治花粉症及建设合理城市绿地提供有效资料.应用Burkard采样器于2010年12月31日至2011年12月31日对北京城区气传花粉浓度进行监测,并对花粉浓度进行统计学分析.研究结果显示,2011年北京城区的花粉季节从3月20日起始,至10月18日截止,持续213d,占全年天数的58％;全年花粉含量月分布呈现两个高峰,第1个高峰为3-4月,主要花粉为木犀科、杨属、柳属等树木花粉,占全年花粉总量的30％;第2个高峰为8-9月,主要花粉为菊科、藜科及苋科等莠草花粉,占全年花粉总量的50％;2011年度北京城区最具代表性的气传花粉来自于菊科,比重占了收集到气传花粉的35％.研究结果还表明,秋季的气传花粉致敏性强,所以北京花粉症的高发季节主要集中在秋季,以8-9月为最高,其中有95％的病人在此期间出现花粉症症状.花粉浓度及飘散规律受当地植被状况及气候等多种因素影响,因此,北京城区空气中气传花粉飘散种类、数量及季节分布规律的调查结果,可以为本地区花粉症防治及绿化品种的选择提供可靠依据.     

实时荧光PCR法同时检测食物中大豆和芹菜致敏原成分

大豆、芹菜等食品原料是一些特殊人群的致敏原。根据大豆atp A基因和芹菜mtd基因设计特异性引物,利用不同荧光素标记的Taq Man探针,建立了一种实时荧光PCR检测方法,可同时检测食物中大豆和芹菜致敏原成分。分别以大豆、芹菜、大米、小麦、大麦、花生、芝麻、玉米、马铃薯、蕃茄、核桃、开心果、腰果、葵花籽、杏仁、苹果、梨、草莓、猪肉、牛肉、羊肉及鱼肉等材料的基因组DNA作为模板,进行PCR扩增实验,结果发现该方法仅能特异性扩增大豆和芹菜致敏原成分。灵敏度测试结果表明大豆和芹菜成分的检出限均达0.01%。因此,本方法可以作为同时检测食品中大豆和芹菜致敏原成分的特异性方法。     

Molecular, immunological, and structural characterization of Phl p 6, a major allergen and P-particle-associated protein from Timothy grass (Phleum pratense) pollen.

Due to the wide distribution and heavy pollen production of grasses, approximately 50% of allergic patients are sensitized against grass pollen allergens. cDNAs coding for two isoforms and four fragments of a major timothy grass (Phleum pratense) pollen allergen, Phl p 6, were isolated by IgE immunoscreening from a pollen expression cDNA library. Recombinant Phl p 6 (rPhl p 6), an acidic protein of 11.8 kDa, was purified to homogeneity as assessed by mass spectrometry and exhibited almost exclusive alpha-helical secondary structure as determined by circular dichroism spectroscopy. Phl p 6 reacted with serum IgE from 75% of grass pollen-allergic patients (n = 171). IgE binding experiments with rPhl p 6 fragments indicated that the N terminus of the allergen is required for IgE recognition. Purified rPhl p 6 elicited dose-dependent basophil histamine release and immediate type skin reactions in patients allergic to grass pollen. A rabbit antiserum raised against purified rPhl p 6 identified it as a pollen-specific protein that, by immunogold electron microscopy, was localized on the polysaccharide-containing wall-precursor bodies (P-particles). The association of Phl p 6 with P-particles may facilitate its intrusion into the deeper airways and thus be responsible for the high prevalence of IgE recognition of Phl p 6. Recombinant native-like Phl p 6 can be used for in vitro as well as in vivo diagnoses of grass pollen allergy, whereas N-terminal deletion mutants with reduced IgE binding capacity may represent candidates for immunotherapy of grass pollen allergy with a low risk of anaphylactic side effects.     

Luminescence immunoassay of pollen allergens on air sampling polytetrafluoroethylene filters.

A new method for quantification of airborne birch and grass pollen allergens collected on porous polytetrafluoroethylene filters has been developed. In this method, the allergens firmly adsorbed to the sampling filter of 25 mm in diameter are reacted with specific antibodies conjugated to alkaline phosphatase, generating a matrix-bound allergen-antibody-phosphatase complex. The filter is then floated on a chemiluminescent enzyme substrate solution. The light intensity of the product is linearly related to the amount of allergen over a large mass range, 0-1000 SQ (1 SQ is about 250 pg of protein). This direct on sampling filter in solution (DOSIS) technique demonstrated intra-assay precisions between 6-16% and 11-15% for the levels of 1-100 SQ units of grass allergen Phl p 5 and 4-400 SQ units of birch allergen Bet v 1, respectively. The limits of quantification for the corresponding allergens were estimated to 0.5 and 2 SQ units. Application of DOSIS to analysis of the grass pollen allergen concentrations of outdoor air for 12 days in July 1998 revealed a correlation coefficient of 0.69 between pollen grain and allergen concentrations for the dry weather period. After rainy days large amounts of grass allergens were present even in the absence of pollen grains.     

Airborne birch and oak pollen grains and birch pollen allergens at a common sampling station in Stockholm

In the present study, the airborne concentrations of birch and oak pollen grains and birch pollen allergens have been recorded in samples from a common sampling station in Stockholm. The sampling period was between April 22^nd and May 31^st 2003. The objectives were to evaluate if analysis of allergen particles in parallel with pollen grains would be relevant to aid subjects suffering from pollinosis. Days with low birch pollen counts had relatively high nominal allergen concentrations in the beginning of the sampling period. The birch pollen grain concentration peaks, during the dry pollination culmination interval in the middle of the period, were associated with correspondingly lower nominal concentrations of allergens than grains. At the end of the sampling period very high nominal amounts of allergen appeared, as reflected by high concentrations of oak pollen grains. The high allergen concentrations were obtained as a result of inherent cross‐reactivity of anti‐ Bet v 1 antibodies with Que a antigens, which are immunologically analogous with Bet v 1. Allergen concentrations increased and decreased after light and heavy rain, respectively. Results obtained indicate that adding a pollen count forecast with allergen concentration data should aid pollen allergic subjects to avoid particulate allergens which might be expected to penetrate more easily than pollen grains into indoor environments.     

Analysis of allergens in ambient aerosols: Comparison of areas subjected to different levels of air pollution

Recent studies describe interactions of pollen surfaces with aerosol particles; pollen surfaces undergo morphological changes and the release of allergens and allergenic fragments from the pollen can be enhanced. Thus allergens from pollen can be found in particle size fractions much smaller than undamaged pollen (<5 μm). This may explain allergic reactions in parts of the lungs which cannot be reached by undamaged pollen. In Switzerland the birch tree (betula verrucosa) major allergen Bet v 1 and the grass (phleum pratense) pollen major allergen Phl p 5 are of particular relevance for inducing pollinosis. In this study aerosols of different aerodynamic diameters were sampled by Andersen-Impactors over 18 months. Sampling areas are subjected to different levels of air pollution (Zürich, Switzerland, urban; Payerne, Switzerland, rural; Davos, Switzerland, alpine). Samples were scanned by electron microscopy and submitted to specific allergen assays (ELISA) for birch pollen major allergen Bet v 1 and grass pollen major allergen Phl p 5 respectively. Particle and major allergen concentrations were highest in Zürich, followed by Payerne and, significantly lower, Davos. Scanning electron microscopy investigations showed interactions of aerosols with pollen surfaces in Zürich and Payerne. The presence of Bet v 1 in smaller aerosol fractions was demonstrated in Zürich and Payerne some weeks before and after birch pollen was counted. An erratum to this article is available at .     

Isolation and partial characterization ofCupressus sempervirens allergens

Summary Allergic rhinitis due to cypress pollen is a well-recognized clinical condition that is evermore frequently diagnosed as a winter allergy in the Mediterranean area. Little is known about the allergen composition of its pollen and the dynamics of its immune response. For these reasons IgE-specific antibody distribution was determined and the allergenic pollen characterized. SDS-PAGE analysis of the whole extract revealed more than ten proteic bands ranging from 10 to 90 kD. The major allergen had a molecular weight of 36 kD and the specific IgE antibody was presene in >95% of the sera tested by immunoblotting technique. Two minor allergens were observed at the 43 and 49 kd protein bands. The results obtained with the whole extract were then compared to those of five commercially available preparations.     

Analysis of allergens in ambient aerosols: Comparison of areas subjected to different levels of air pollution

Recent studies describe interactions of pollen surfaces with aerosol particles; pollen surfaces undergo morphological changes and the release of allergens and allergenic fragments from the pollen can be enhanced. Thus allergens from pollen can be found in particle size fractions much smaller than undamaged pollen (<5m). This may explain allergic reactions in parts of the lungs which cannot be reached by undamaged pollen. In Switzerland the birch tree (betula verrucosa) major allergen Bet v 1 and the grass (phleum pratense) pollen major allergen Phl p 5 are of particular relevance for inducing pollinosis. In this study aerosols of different aerodynamic diameters were sampled by Andersen-Impactors over 18 months. Sampling areas are subjected to different levels of air pollution (Zürich, Switzerland, urban; Payerne, Switzerland, rural: Davos, Switzerland, alpine). Samples were scanned by electron microscopy and submitted to specific allergen assays (ELISA) for birch pollen major allergen Bet v 1 and grass pollen major allergen Phl p 5 respectively. Particle and major allergen concentrations were highest in Zürich, followed by Payerne and, significantly lower, Davos. Scanning electron microscopy investigations showed interactions of aerosols with pollen surfaces in Zürich and Payerne. The presence of Bet v 1 in smaller aerosol fractions was demonstrated in Zürich and Payerne some weeks before and after birch pollen was counted.     

nCup a 1 as a marker of allergy to cypress pollen

The increase in polysensitisations among allergic patients has led us to search for suitable means of diagnosis for identifying true sensitisation, and distinguishing true sensitisation from cross-reactivity. Cross-reactive carbohydrate determinants (CCDs) present in glycoproteins from cypress pollen extracts have been linked with such cross-reactivity, particularly in in vitro assays. The application of component-resolved diagnosis using recombinant allergens makes it possible to identify true allergens. The problem arises when the allergen available for the usual diagnostic methods, which are used as a reference for the diagnosis of allergy to cypress pollen nCup a 1, is a native allergen. The aim of the study was to validate the native allergen nCup a as a marker of true sensitisation to cypress pollen. The sera of 96 subjects with a proven allergy to cypress pollen were analysed. We then quantified IgE specific to Cupressus arizonica and to nCup a 1 and also analysed the CCDs in subjects sensitised to several tree pollen allergens, presenting with MUXF3-specific IgE. Results revealed that there is a statistically significant correlation between conventional diagnostic techniques used to determine allergy to cypress pollen (SPT and IgE Cupressus arizonica) and sensitisation to nCup a 1. CCD quantification in subjects sensitised to several tree pollen antigens showed that these did not interfere with our results. We validated the native Cupressus arizonica allergen, nCup a 1, as a marker of allergy to cypress pollen in our population.     

Aeroallergens: a comparative study of two monitoring methods

Olive and grass pollen grains are the major causes of hay fever in the Mediterranean region. A number of samplers and methods have been developed in recent years in order to obtain reliable data regarding airborne allergen concentrations. This paper reports on a detailed comparison of two samplers—Cyclone and ChemVol—and on the parameters that could influence their efficiency. Airborne concentrations of two key olive and grass allergens, Ole e 1 and Phl p 5, respectively, were monitored over two years with different weather patterns, 2012 and 2014. Allergenic particles were quantified by ELISA assay, and results were compared with pollen concentrations monitored using a Hirst-type volumetric spore trap over the same study periods. The influence of weather-related parameters on local airborne pollen and allergen concentrations was also analysed. Although a positive correlation was detected between results obtained using the two samplers during the pollen season, results for the cumulative annual Allergen Index varied considerably. The two samplers revealed a positive correlation between pollen concentrations and both minimum temperature during the warmer year (2012) and maximum temperature during the cooler year (2014); a negative significant correlation was observed in both cases with rainfall and relative humidity. In summary, although some differences were observed between the two samplers studied, both may be regarded as suitable for allergen detection.     

Nonanaphylactic synthetic peptides derived from B cell epitopes of the major grass pollen allergen, Phl p 1, for allergy vaccination.

Worldwide more than 200 million individuals are allergic to group 1 grass pollen allergens. We have used the major timothy grass pollen allergen Phl p 1, which cross-reacts with most grass-, corn-, and monocot-derived group 1 allergens to develop a generally applicable strategy for the production of hypoallergenic allergy vaccines. On the basis of the experimentally determined B cell epitopes of Phl p 1, we have synthesized five synthetic peptides. These peptides are derived from the major Phl p 1 IgE epitopes and were between 28-32 amino acids long. We demonstrate by nuclear magnetic resonance that the peptides exhibit no secondary and tertiary structure and accordingly failed to bind IgE antibodies from grass pollen allergic patients. The five peptides, as well as an equimolar mixture thereof, lacked allergenic activity as demonstrated by basophil histamine release and skin test experiments in grass pollen allergic patients. When used as immunogens in mice and rabbits, the peptides induced protective IgG antibodies, which recognized the complete Phl p 1 wild-type allergen and group 1 allergens from other grass species. Moreover, peptide-induced antibodies inhibited the binding of grass pollen allergic patients IgE antibodies to the wild-type allergen. We thus demonstrate that synthetic hypoallergenic peptides derived from B cell epitopes of major allergens represent safe vaccine candidates for the treatment of IgE- mediated allergies.