Storage mites

The interest in allergy to storage mites has increased over the past few years. Storage mites feed on a variety of substances and they can be found in many different products such as grain, flour, hay and straw, but also in house dust samples. The more common genera areLepidoglyphus, Tyrophagus, Glycyphagus, Acarus andBlomia. Several species of storage mites have been shown to cause IgE-mediated sensitization among rural workers, who to a varying extent develop asthma, rhinitis or conjunctivitis when exposed to barn dust. However, a number of studies, have reported on sensitization to storage mites also among urban people, indicating that sensitization is not restricted to individuals with occupational exposure. Regarding the allergenic relationship between storage mites and house dust mites, there appears to be a limited allergenic cross-reactivity between the two species. However, both species also possess their own unique allergens. Further research on identification and characterization of storage mite allergens and their cross-reactivity is required to understand the complexity of epitopes and allergens.     

Characterization of Rhinitis According to the Asthma Status in Adults Using an Unsupervised Approach in the EGEA Study

Background

The classification of rhinitis in adults is missing in epidemiological studies.

Objective

To identify phenotypes of adult rhinitis using an unsupervised approach (data-driven) compared with a classical hypothesis-driven approach.

Methods

983 adults of the French Epidemiological Study on the Genetics and Environment of Asthma (EGEA) were studied. Self-reported symptoms related to rhinitis such as nasal symptoms, hay fever, sinusitis, conjunctivitis, and sensitivities to different triggers (dust, animals, hay/flowers, cold air…) were used. Allergic sensitization was defined by at least one positive skin prick test to 12 aeroallergens. Mixture model was used to cluster participants, independently in those without (Asthma-, n = 582) and with asthma (Asthma+, n = 401).

Results

Three clusters were identified in both groups: 1) Cluster A (55% in Asthma-, and 22% in Asthma+) mainly characterized by the absence of nasal symptoms, 2) Cluster B (23% in Asthma-, 36% in Asthma+) mainly characterized by nasal symptoms all over the year, sinusitis and a low prevalence of positive skin prick tests, and 3) Cluster C (22% in Asthma-, 42% in Asthma+) mainly characterized by a peak of nasal symptoms during spring, a high prevalence of positive skin prick tests and a high report of hay fever, allergic rhinitis and conjunctivitis. The highest rate of polysensitization (80%) was found in participants with comorbid asthma and allergic rhinitis.

Conclusion

This cluster analysis highlighted three clusters of rhinitis with similar characteristics than those known by clinicians but differing according to allergic sensitization, and this whatever the asthma status. These clusters could be easily rebuilt using a small number of variables.     

SLPI prevents cytokine release in mite protease-exposed conjunctival epithelial cells

House dust mites are a major source of allergens associated with allergic diseases including allergic conjunctivitis. Here, we demonstrate that mite-derived serine protease activity induces the release of cytokines from human ocular conjunctival epithelial cells in vitro and innate antiproteases, secretory leukocyte protease inhibitor (SLPI) and α1-antitrypsin, can inhibit the response. An extract prepared from a whole-mite culture induced the release of IL-6 and IL-8 and upregulated their gene expression in the human conjunctival epithelial cell line Chang, responses which were inhibited not only by a synthetic serine protease-specific inhibitor, AEBSF, but also by SLPI and α1-antitrypsin at a physiologically relevant concentration. The findings suggest a homeostatic role for SLPI and α1-antitrypsin against the proteases contained in allergen sources in the ocular conjunctiva and that exposure to house dust particles containing mite-derived serine protease activity could be involved in the initiation of sensitization through the ocular conjunctival epithelium and/or exacerbation of allergic conjunctivitis.     

Lung disease in farmers.

Lung diseases in farmers attributable to their occupation include (a) farmer''s lung, caused by exposure to mouldy hay, (b) the asthma caused by exposure to grain dust and (c) silo-filler''s disease. Their prevalence in Canada is unknown. Farmer''s lung results from inhalation of mould spores in hay; the mechanism is immunologic. The exact cause and mechanism of grain dust asthma are unknown but may be immunologic. Silo-filler''s disease is caused by the toxic effects of inhaled nitrogen dioxide.     

Nasal hyperreactivity and inflammation in allergic rhinitis

The history of allergic disease goes back to 1819, when Bostock described his own 'periodical affection of the eyes and chest', which he called 'summer catarrh'. Since they thought it was produced by the effluvium of new hay, this condition was also called hay fever. Later, in 1873, Blackley established that pollen played an important role in the causation of hay fever. Nowadays, the definition of allergy is 'An untoward physiologic event mediated by a variety of different immunologic reactions'. In this review, the term allergy will be restricted to the IgE-dependent reactions. The most important clinical manifestations of IgE-dependent reactions are allergic conjunctivitis, allergic rhinitis, allergic asthma and atopic dermatitis. However, this review will be restricted to allergic rhinitis. The histopathological features of allergic inflammation involve an increase in blood flow and vascular permeability, leading to plasma exudation and the formation of oedema. In addition, a cascade of events occurs which involves a variety of inflammatory cells. These inflammatory cells migrate under the influence of chemotactic agents to the site of injury and induce the process of repair. Several types of inflammatory cells have been implicated in the pathogenesis of allergic rhinitis. After specific or nonspecific stimuli, inflammatory mediators are generated from cells normally found in the nose, such as mast cells, antigen-presenting cells and epithelial cells (primary effector cells) and from cells recruited into the nose, such as basophils, eosinophils, lymphocytes, platelets and neutrophils (secondary effector cells). This review describes the identification of each of the inflammatory cells and their mediators which play a role in the perennial allergic processes in the nose of rhinitis patients.     

Grain dust and the lungs.

Grain dust is composed of a large number of materials, including various types of grain and their disintegration products, silica, fungi, insects and mites. The clinical syndromes described in relation to exposure to grain dust are chronic bronchitis, grain dust asthma, extrinsic allergic alveolitis, grain fever and silo-filler''s lung. Rhinitis and conjunctivitis are also common in grain workers. While the concentration and the quality of dust influence the frequency and the type of clinical syndrome in grain workers, host factors are also important. Of the latter, smoking is the most important factor influencing the frequency of chronic bronchitis. The role of atopy and of bronchial hyperreactivity in grain dust asthma has yet to be assessed. Several well designed studies are currently being carried out in North America not only to delineate the frequency of the respiratory abnormalities, the pathogenetic mechanisms and the host factors, but also to establish a meaningful threshold limit concentration for grain dust.     

Increased hypoxia-inducible factor 1alpha expression in lung cells of horses with recurrent airway obstruction

ABSTRACT: BACKGROUND: Recurrent airway obstruction (RAO, also known as equine heaves) is an inflammatory condition caused by exposure of susceptible horses to organic dusts in hay. The immunological processes responsible for the development and the persistence of airway inflammation are still largely unknown. Hypoxia-inducible factor (Hif) is mainly known as a major regulator of energy homeostasis and cellular adaptation to hypoxia. More recently however, Hif also emerged as an essential regulator of innate immune responses. Here, we aimed at investigating the potential involvement of Hif1-alpha in myeloid cells in horse with recurrent airway obstruction. RESULTS: In vitro, we observed that Hif is expressed in equine myeloid cells after hay dust stimulation and regulates genes such as tumor necrosis factor alpha (TNF-alpha), interleukin-8 (IL-8) and vascular endothelial growth factor A (VEGF-A). We further showed in vivo that airway challenge with hay dust upregulated Hif1-alpha mRNA expression in myeloid cells from the bronchoalveolar lavage fluid (BALF) of healthy and RAO-affected horses, with a more pronounced effect in cells from RAO-affected horses. Finally, Hif1-alpha mRNA expression in BALF cells from challenged horses correlated positively with lung dysfunction. CONCLUSION: Taken together, our results suggest an important role for Hif1-alpha in myeloid cells during hay dust-induced inflammation in horses with RAO. We therefore propose that future research aiming at functional inactivation of Hif1 in lung myeloid cells could open new therapeutic perspectives for RAO.     

义乌地区儿童过敏性结膜炎过敏原分析

目的了解过敏性结膜炎患儿常见过敏原及其分布特征,为预防和脱敏治疗提供依据。方法采用免疫印迹法对363例过敏性结膜炎患儿进行血清过敏原检测,并对结果进行分组比较。结果患儿中检出率居前3位的吸入性过敏原分别为尘螨(50.41%)、猫毛(3.03%)和霉菌(2.48%);检出率居前3位的食物性过敏原分别为淡水鱼(10.74%)、海鱼(7.44%)和鸡蛋白(6.34%)。吸入性过敏原(62.26%)和食物性过敏原(41.60%)总检出率比较差异有统计学意义(P0.05)。婴幼儿组、学龄前组和学龄组患儿均以尘螨为常见过敏原,其检出率分别为33.33%、52.76%和52.00%。不同年龄患儿牛奶过敏检出率比较差异有统计学意义(P0.05),婴幼儿组牛奶过敏检出率最高,为12.82%。男、女患儿过敏原阳性率比较差异无统计学意义(P0.05)。不同年龄患儿过敏原阳性率比较差异无统计学意义(P0.05)。婴幼儿组、学龄前组和学龄组患儿均以单纯吸入性过敏原和单一过敏原为常见。1月-3月为儿童过敏性结膜炎的低发季节。结论通过血清过敏原检测可明确过敏性结膜炎的过敏原。尘螨是本地区儿童过敏性结膜炎常见过敏原。     

Acute Increase of Children's Conjunctivitis Clinic Visits by Asian Dust Storms Exposure - A Spatiotemporal Study in Taipei,Taiwan

Adverse health impacts of Asian dust storms (ADS) have been widely investigated and discussed in respiratory disease, but no study has examined the association between ADS events and their impact on eye diseases, especially in children. The impact of ADS events on the incidence of children''s conjunctivitis is examined by analyzing the data from children''s clinic visits registered in the 41 districts of Taipei area in Taiwan during the period 2002–2007. The structural additive regression modeling approach was used to assess the association between ADS events and clinic visits for conjunctivitis in children with consideration of day-of-the-week effects, temperature, and air quality levels. This study identifies an acute increase in the relative rate for children''s conjunctivitis clinic visits during ADS periods with 1.48% (95% CI = 0.79, 2.17) for preschool children (aged <6 years old) and 9.48% (95% CI = 9.03, 9.93) for schoolchildren (aged ≥6 years old), respectively. The relative rates during post-ADS periods were still statistically significant, but much lower than those during ADS periods. The spatial analysis presents geographic heterogeneity of children''s conjunctivitis clinic visits where higher relative rates were more likely observed in the most populated districts Compared to previous ADS studies related to respiratory diseases, our results reveals significantly acute impacts on children''s conjunctivitis during ADS periods, and much influence on schoolchildren. Vulnerable areas were also identified in high density population.     

Methods for reducing particle concentrations of Aspergillus fumigatus conidia and mouldy hay dust

The effectiveness of commercially available domestic air purifiers to reduce airborne Aspergillus fumigatus conidia and mouldy hay dust was investigated. It was found that the rate of particle clearance is a function of the volume of air passing through the purifiers but that the low throughflow of air makes their use of little value in clearing particles from a normal sized room. Vacuum cleaners were more effective than air purifiers because of their higher air throughput, so too were high volume fan systems in conjunction with simple filtration units. Ionizers had no effect but steam condensation was very efficient at clearing airborne particles.     

16S rRNA基因高通量测序方法检测奶牛场常用干草表面微生物群落结构及多样性

【目的】随着中国奶牛业的发展,干草需求量与日俱增。作为天然牧草,干草可以成为家畜传播病原体的载体。以干草表面附着物为研究对象,了解干草中细菌群落结构以及致病菌属特征。【方法】对来自6个不同奶牛场饲草舍的干草样本,应用Illumina Mi Seq高通量测序技术测定干草表面附着物细菌的16S r RNA基因V3-V4变异区序列,分析不同干草样本细菌群落组成。【结果】干草样本中的细菌在97%的相似水平下共得到OTU个数为15 416,涵盖了29门87纲144目219科323属的细菌。微生物多样性分析表明,干草样本具有很高的细菌多样性,不同样本多样性存在差异。对干草样本菌群中丰度较高的14种病原菌属进行分析,发现相较于人工种植牧草制备的干草,天然牧草制备的干草中病原菌属丰度较高。【结论】研究解析了干草样本中微生物的多样性、丰度及主要病原菌属的特征,对奶牛场疾病防控有一定指导意义。     

Better than nature: the changing treatment of asthma and hay fever in the United States, 1910–1945

Through the early twentieth century, asthmatics were advised to move to a more suitable climate, or to vacation in one during their worst season. In the late nineteenth century, physicians sought to quantify the ideal temperature, humidity, altitude, and pollen count to help travellers to select a suitable place, but these investigations led some physicians to question contradictions between expected and actual conditions. Given that even the best climate was not perfect at all times, and that many patients could not afford to travel or relocate, a group of physicians—who came to be known as allergists—sought ways to adapt their patients to any climate through changes in their indoor environments and treatments to manage their symptoms. Their approach included changes in household design, furnishings, and cleaning techniques, especially a strict avoidance of dust, which could carry feathers, animal hair, skin debris, pollen, moulds, and an unknown ‘dust’ allergen. Air filtering and air conditioning were also promoted as ways to protect asthmatics and hay fever sufferers. These modifications of patients and their microenvironments signalled both a move away from climactic approaches to asthma and toward the sanitary, modernist home of the twentieth century.     

Pulmonary intravascular macrophages as proinflammatory cells in heaves, an asthma-like equine disease

Heaves, an obstructive neutrophilic airway inflammation of horses, is triggered by dust components such as endotoxin and has similarities to human asthma. Pulmonary intravascular macrophages (PIMs) increase horses' sensitivity to endotoxin-induced lung inflammation; however, their role in an airborne pathology remains unknown. Therefore, we investigated the role of PIMs in the development of heaves in horses. Clinical and inflammatory responses were evaluated following induction of heaves by moldy hay exposure and PIM depletion with gadolinium chloride (GC). Mares (N = 9) were exposed to four treatments: alfalfa cubes (Cb), alfalfa cubes + GC (Cb-GC), moldy hay (MH), and moldy hay + GC (MH-GC). Clinical scores and neutrophil concentrations in bronchoalveolar lavage (BAL) fluid were higher when mares received MH compared with MH-GC. BAL cells from MH-GC-treated mares had significantly lower IL-8 and TLR4 mRNA expression compared with MH-treated mares. In vitro LPS challenge significantly increased IL-8 but not TLR4 mRNA expression in BAL cells recovered from horses fed with MH, but not from the MH-GC treatment. In summary, PIM depletion attenuated clinical scores, reduced the alveolar migration of neutrophils, and decreased the expression of proinflammatory molecules in BAL cells of heaves horses, suggesting a proinflammatory role of PIMs in the development of airborne pathology.     

Expression of conditioned preference for low-quality food in sheep is modulated by foraging costs

Past positive experiences can increase herbivores’ motivation to eat low-quality foods. However, this is not always translated into a higher preference for low-quality foods in choice tests among foods of higher nutritional quality. Foraging behavior is also affected by properties of the feeding context because the quality and abundance of foods in nature change in time and space. We hypothesized that in a choice situation, the expression of a past positive experience with a low-quality food is modulated by the costs associated with selecting a high-quality food option. A total of 24 sheep were randomly assigned into two groups (n=12). During conditioning phase, one group (CS+; i.e., conditioned group) was fed with oat hay (a low-quality food) for 20 min and immediately after a ration of soybean meal (a nutritious food), whereas the other group was also fed with oat hay but the offer of soybean meal was delayed 5 h (CS−; i.e., control group). After conditioning, we assessed sheep motivation to eat the oat hay in an experimental arena in which accessibility to alfalfa hay (a high-quality food) was increasingly restricted. When alfalfa hay was readily accessible, CS+ and CS− sheep almost exclusively selected this food, showing a small and similar preference for oat hay. However, when accessibility to alfalfa hay decreased, intake and selection of oat hay was greater in the CS+ sheep than in the CS− sheep. The latter was a consequence of differential changes in behavior between groups; for example, sheep in CS+ spent more time foraging oat hay and were more likely to switch to oat hay if they had previously been eating alfalfa hay than sheep in CS−. Our results show that behavioral expression of the conditioned preference for a low-quality food depends on parameters of the feeding context (e.g., availability). We suggest that this can be the link between learning models and optimal foraging models of diet selection.     

Evaluation of Initial Restoration Measures during the Restoration of Calcareous Grasslands on Former Arable Fields

In 1993, experiments on the restoration of calcareous grasslands on ex‐arable fields were started in order to provide new habitats for species of a small nature reserve with ancient grasslands north of Munich (Germany). The effects of diaspore transfer by the application of seed‐containing hay on vegetation establishment were studied on restoration fields with and without topsoil removal for 5 years. The aim of the study was to assess plant diversity for the evaluation of restoration success by different methods including determination of species with viable seeds in the hay by germination tests, phenological investigations on hay‐transfer source sites at the time of harvest, and vegetation analyses on the restoration sites. Total seed content of the hay and the number and composition of plant species with viable seeds were affected by the time of harvesting and differed between a site which had been used as arable field until 1959 and ancient grassland sites. Nevertheless, the number of established hay‐transfer species showed only few differences between restoration fields. The proportion of species transferred to restoration fields in relation to the number of species with viable seeds in the hay was between 69 and 89%. Five years after the hay transfer, the proportion of the established species was still between 58 and 76%. Up to now, topsoil removal had no significant effect on the number of established hay‐transfer species. After triple hay application the absolute number of transferred grassland species was higher than on sites with single hay application, but restoration efficiency was lower because many of the species with viable seeds in the hay did not establish. In general, our results showed that the transfer of autochthonous hay is a successful method to overcome dispersal limitation in restoration projects.     

Microbial aerosols and actinomycetes in etiological considerations of mushroom workers' lungs.

Spent steamed compost, phase II compost, and dust emanating from spent compost during dumping of stationary-bed mushroom houses were examined bacteriologically. The total count for spent compost was 16 X 10(8) microorganisms per g. The total count for dust was 333 microorganisms per liter of air. Actinomycetes belonging to the genus Streptomyces often constituted 90% or more of isolates from dust, whereas mold spores constituted approximately 5%. Dust weight averaged 3.4 mg/liter of air and contained approximately 33% inanimate and 67% animate (microbial) particles. Spent compost and casing contained approximately 60% moisture; the average pH of compost was 6.93, and that of casing was 7.70. Ouchterlony precipitin results with antisera from workers afflicted with either farmer's or mushroom worker's lung were positive for Bacillus licheniformis, Micropolyspora faeni, Thermoactinomyces vulgaris, Aspergillus fumigatus, Humicola grisea var. thermoidea, spent compost, and phase II compost. Their usefulness in determining the etiology of this and related forms of allergic alveolitis is questioned and discussed. The relationship of dust particle size; microbial species, prevalence and antigenicity; and compost antigenicity to the etiology of mushroom worker's lung is discussed. The microbial ecology of mushroom compost and moldy hay associated with farmer's lung is compared.     

Study of infectious conjunctivitis among children in rural areas of Qinghai province

Infectious conjunctivitis is no longer a common eye disease in cities and developed areas, but in remote mountainous regions of China where living conditions are relatively under-developed, the occurrence of infectious conjunctivitis remains a public health issue. Here, we evaluate the ratio of infectious conjunctivitis among primary school students in the rural areas of Xunhua, Huangyuan, and Huzhu Counties in the Qinghai province of China, and report the microorganisms involved in causing infection. Of the 765 eligible primary school students, 694 participated to this study(a response rateof 90.7%), 381 boys and 313 girls, with a mean age of 7.52 years(range 7–9 years). A clinical diagnosis of infectious conjunctivitis was returned for 238 of the 694 children examined. The ratio of infectious conjunctivitis in Xunhua County(46.64%) was higher compared to that in Huangyuan(26.67%; P=0.03) and Huzhu Counties(23.61%; P=0.02). The leading cause of conjunctivitis was bacterial, followed by chlamydial and viral. Our results show that there is a high ratio of infectious conjunctivitis among rural primary school students in Qinghai province.     

Localization of ruminal cellulolytic bacteria on plant fibrous materials as determined by fluorescence in situ hybridization and real-time PCR

To visualize and localize specific bacteria associated with plant materials, a new fluorescence in situ hybridization (FISH) protocol was established. By using this protocol, we successfully minimized the autofluorescence of orchard grass hay and detected rumen bacteria attached to the hay under a fluorescence microscope. Real-time PCR assays were also employed to quantitatively monitor the representative fibrolytic species Fibrobacter succinogenes and Ruminococcus flavefaciens and also total bacteria attached to the hay. F. succinogenes was found firmly attached to not only the cut edges but also undamaged inner surfaces of the hay. Cells of phylogenetic group 1 of F. succinogenes were detected on many stem and leaf sheath fragments of the hay, even on fragments on which few other bacteria were seen. Cells of phylogenetic group 2 of F. succinogenes were often detected on hay fragments coexisting with many other bacteria. On the basis of 16S rRNA gene copy number analysis, the numbers of bacteria attached to the leaf sheaths were higher than those attached to the stems (P<0.05). In addition, R. flavefaciens had a greater tendency than F. succinogenes to be found on the leaf sheath (P<0.01) with formation of many pits. F. succinogenes, particularly phylogenetic group 1, is suggested to possibly play an important role in fiber digestion, because it is clearly detectable by FISH and is the bacterium with the largest population size in the less easily degradable hay stem.     

Induction of low-nutritious food intake by subsequent nutrient supplementation in sheep (Ovis aries)

Acceptance of and preference for a particular food depends not only on its intrinsic (e.g. nutritional) properties but also on expected or recent food experiences. An instance of this type of phenomenon has been called induction effect, which consists of an increased intake of a type of food when it precedes a hedonically preferred food in a sequence familiar to the animal, relative to controls that have access only to the less-preferred food. The purpose of our study was to assess intake induction of a low-nutritious food when followed by different high-nutritious supplements in sheep (Ovis aries). In this experiment, we ran a supplemented phase where animals fed oat hay (a low-nutritious food) in the first part of the daily feeding sessions followed by a supplement with either a high (soya bean meal; group GS) or a low (ground corn; group GC) protein–energy ratio in the second part ate more oat hay than controls that were fed oat hay in both parts of sessions (group GH). In addition, supplemented animals presented a stronger preference for oat hay over alfalfa hay than controls in a subsequent choice. When all animals received no food in the second part of the sessions (Non-supplemented phase), intake of oat hay converged to the control's intake level in all the groups, suggesting that the presence of supplements after access to oat hay was responsible for intake induction. Lastly, we repeated the supplemented phase with a different control group where animals received oat hay in the first part of the sessions and no food in the second part (group NF), thus equalizing groups in terms of the time of access to oat hay in a session. Groups GS and GC still developed higher intake of oat hay than group NF. In both supplemented phases of the experiment, we estimated animals’ daily metabolizable energy (ME) and crude protein (CP) intake. CP intake was higher in group GS than in groups GC, GH and NF, but there was no difference between group GC and the controls. In turn, groups did not differ in ME intake in the First supplemented phase, and only group GS presented higher ME intake than the rest of the groups in the Second supplemented phase. Therefore, a nutritional account of the present induction effect seems insufficient. We propose that a learned association between oat hay and the post-ingestive feedback from the subsequent high-nutritious supplements underlay sheep's intake induction and increased preference for oat hay.