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Sample records for dust mite reveals

  1. Dust mite (image)

    MedlinePlus

    ... is a magnified photograph of a dust mite. Mites are carriers (vectors) of many important diseases including typhus (scrub and murine) and rickettsialpox. (Image courtesy of the Centers for Disease Control and ...

  2. [House dust mite allergy].

    PubMed

    Carrard, A; Pichler, C

    2012-04-01

    House dust mites can be found all over the world where human beings live independent from the climate. Proteins from the gastrointestinal tract- almost all known as enzymes - are the allergens which induce chronic allergic diseases. The inhalation of small amounts of allergens on a regular base all night leads to a slow beginning of the disease with chronically stuffed nose and an exercise induced asthma which later on persists. House dust mites grow well in a humid climate - this can be in well isolated dwellings or in the tropical climate - and nourish from human skin dander. Scales are found in mattresses, upholstered furniture and carpets. The clinical picture with slowly aggravating complaints leads quite often to a delayed diagnosis, which is accidently done on the occasion of a wider spectrum of allergy skin testing. The beginning of a medical therapy with topical steroids as nasal spray or inhalation leads to a fast relief of the complaints. Although discussed in extensive controversies in the literature - at least in Switzerland with the cold winter and dry climate - the recommendation of house dust mite avoidance measures is given to patients with good clinical results. The frequent ventilation of the dwelling with cold air in winter time cause a lower indoor humidity. Covering encasings on mattresses, pillow, and duvets reduces the possibility of chronic contact with mite allergens as well as the weekly changing the bed linen. Another option of therapy is the specific immunotherapy with extracts of house dust mites showing good results in children and adults. Using recombinant allergens will show a better quality in diagnostic as well as in therapeutic specific immunotherapy. PMID:22477664

  3. [House dust mite allergy].

    PubMed

    Carrard, A; Pichler, C

    2012-04-01

    House dust mites can be found all over the world where human beings live independent from the climate. Proteins from the gastrointestinal tract- almost all known as enzymes - are the allergens which induce chronic allergic diseases. The inhalation of small amounts of allergens on a regular base all night leads to a slow beginning of the disease with chronically stuffed nose and an exercise induced asthma which later on persists. House dust mites grow well in a humid climate - this can be in well isolated dwellings or in the tropical climate - and nourish from human skin dander. Scales are found in mattresses, upholstered furniture and carpets. The clinical picture with slowly aggravating complaints leads quite often to a delayed diagnosis, which is accidently done on the occasion of a wider spectrum of allergy skin testing. The beginning of a medical therapy with topical steroids as nasal spray or inhalation leads to a fast relief of the complaints. Although discussed in extensive controversies in the literature - at least in Switzerland with the cold winter and dry climate - the recommendation of house dust mite avoidance measures is given to patients with good clinical results. The frequent ventilation of the dwelling with cold air in winter time cause a lower indoor humidity. Covering encasings on mattresses, pillow, and duvets reduces the possibility of chronic contact with mite allergens as well as the weekly changing the bed linen. Another option of therapy is the specific immunotherapy with extracts of house dust mites showing good results in children and adults. Using recombinant allergens will show a better quality in diagnostic as well as in therapeutic specific immunotherapy.

  4. Dust mite-proof pillow cover (image)

    MedlinePlus

    ... the amount of dust mites encase mattresses, box springs, and pillows with mite-proof covers. Further methods consist of washing bedding once a week in hot water, and dusting with a wet cloth once a ...

  5. House dust mites, our intimate associates.

    PubMed

    Nadchatram, M

    2005-06-01

    House dust mites have lived in human contact from time immemorial. Human dander or dead skin constitutes the major organic component of the house dust ecosystem. Because the mites feed on dander, dust mites and human association will continue to co-exist as part of our environment. Efficient house-keeping practice is the best form of control to reduce infestation. However, special precautions are important when individuals are susceptible or sensitive to dust mites. House dust mites are responsible for causing asthma, rhinitis and contact dermatitis. The respiratory allergies are caused by the inhalation of dead or live mites, their faecal matter or other byproducts. Immune factors are of paramount importance in the development of dust related or mite induced respiratory diseases. House dust mites were found in some 1,000 samples of dust taken from approximately 330 dwellings in Peninsular Malaysia and Singapore. Mattresses, carpets, corners of a bedroom, and floor beneath the bed are favourable dust mite habitats. The incriminating species based on studies here and elsewhere, as well as many other species of dust mites of unknown etiological importance are widely distributed in Malaysian homes. Density of dust mites in Malaysia and Singapore is greater than in temperate countries. Prevention and control measures with reference to subjects sensitive to dust mite allergies, including chemical control described in studies conducted in Europe and America are discussed. However, a cost free and most practical way to remove mites, their faecal matter and other products is to resort to sunning the bedding and carpets to kill the living mites, and then beaten and brushed to remove the dust and other components.

  6. [House dust mites and their allergens].

    PubMed

    Bessot, J-C; Pauli, G

    2011-02-01

    The taxonomy, anatomy, life cycle and ecology of Pyroglyphidae mites and storage mites (Acaridae, Glycyphagidae, B. tropicalis) are described. Pyroglyphidae and storage mites have similar morphologies: they are octopods, with characteristic gnathosoma and sensory hairs. Salivary glands and the mid gut produce most of the allergens excreted, which are enzymatic proteins. Biological cycles and development are similar, although fecundity is superior in storage mites compared to the Pyroglyphides. Relative humidity is the main parameter, which regulates mite development, with a higher degree of temperature and humidity required for storage mites. Bedding is the ecological niche of Pyroglyphidae, which feed on human skin. Moulds and food products are the storage mite biotope from which they spread in the dwelling. Initially considered as rural mites, storage mites are also present in urban dwellings. B. tropicalis, in tropical regions is a true domestic mite. Because of this, it is justified to denominate Pyroglyphidae "house dust mites" and storage mites "domestic mites". In addition to the respiratory allergic symptoms, the storage mites can also cause occupational contact dermatoses.

  7. Cross-reactivity between storage and dust mites and between mites and shrimp.

    PubMed

    Arlian, Larry G; Morgan, Marjorie S; Vyszenski-Moher, DiAnn L; Sharra, Denada

    2009-02-01

    Many patients have sensitivities to multiple species of storage and house dust mites. It is not clear if this is because patients have multiple sensitivities to species-specific mite allergens or if these mites share many cross-reacting allergens. Our objective was to further define the cross-allergenicity between several species of storage and house dust mites using crossed-immunoelectrophoresis (CIE), crossed-radioimmunoelectrophoresis (CRIE), immunoblotting, and ELISA. CIE and CRIE reactions revealed that storage mites shared two cross-antigenic molecules and one of these bound IgE in a serum pool from mite allergic patients. Antibody in anti-sera built to each species of mite recognized many SDS-PAGE resolved proteins of other mite species and this suggested the potential for other cross-reactive allergens. Among patient sera, IgE bound to many different proteins but few had IgE that bound to a protein with common molecular weights across the mite species and this suggested mostly species-specific allergens. Antiserum built to each mite species precipitated one protein in shrimp extracts that bound anti-Der p 10 (tropomyosin) and IgE in the serum pool. Anti-Der p 10 showed strong binding to shrimp tropomyosin but very little to any of the mite proteins. ELISA showed the mite extracts contained very little tropomyosin. The storage and dust mites investigated contain mostly species-specific allergens and very small amounts of the pan-allergen tropomyosin compared to shrimp and snail. PMID:18850281

  8. Air-conditioner filters enriching dust mites allergen

    PubMed Central

    Zhan, Xiaodong; Li, Chaopin; Xu, Haifeng; Xu, Pengfei; Zhu, Haibin; Diao, Jidong; Li, Na; Zhao, Beibei

    2015-01-01

    We detected the concentration of dust mites allergen (Der f1 & Der p1) in the air of different places before and after the starting of air-conditioners in Wuhu City, Anhui, China, and to discuss the relation between the dust mites allergen in air-conditioner filters and the asthma attack. The dust samples were collected from the air-conditioner filters in dining rooms, shopping malls, hotels and households respectively. Concentrations of dust mites major group allergen 1 (Der f 1, Der p1) were detected with enzyme linked immunosorbent assay (ELISA), and the dust mite immune activities were determined by dot-ELISA. The concentration of Der f1 in dining rooms, shopping malls, hotels and households was 1.52 μg/g, 1.24 μg/g, 1.31 μg/g and 1.46 μg/g respectively, and the concentration of Der p1 in above-mentioned places was 1.23 μg/g, 1.12 μg/g, 1.16 μg/g and 1.18 μg/g respectively. The concentration of Der f1 & Der p1 in air was higher after the air-conditioners starting one hours later, and the difference was significant (P<0.05, respectively). Additionally, dot-ELISA findings revealed that the allergen extracted from the dust was capable of reacting with IgE from the sera of asthma mice allergic to dust mites. The study concludes that air-conditioner filters can enrich dust mites major group allergen, and the allergens can induce asthma. The air-conditioner filters shall be cleaned or replaced regularly to prevent or reduce accumulation of the dust mites and its allergens. PMID:26064381

  9. Air-conditioner filters enriching dust mites allergen.

    PubMed

    Zhan, Xiaodong; Li, Chaopin; Xu, Haifeng; Xu, Pengfei; Zhu, Haibin; Diao, Jidong; Li, Na; Zhao, Beibei

    2015-01-01

    We detected the concentration of dust mites allergen (Der f1 & Der p1) in the air of different places before and after the starting of air-conditioners in Wuhu City, Anhui, China, and to discuss the relation between the dust mites allergen in air-conditioner filters and the asthma attack. The dust samples were collected from the air-conditioner filters in dining rooms, shopping malls, hotels and households respectively. Concentrations of dust mites major group allergen 1 (Der f 1, Der p1) were detected with enzyme linked immunosorbent assay (ELISA), and the dust mite immune activities were determined by dot-ELISA. The concentration of Der f1 in dining rooms, shopping malls, hotels and households was 1.52 μg/g, 1.24 μg/g, 1.31 μg/g and 1.46 μg/g respectively, and the concentration of Der p1 in above-mentioned places was 1.23 μg/g, 1.12 μg/g, 1.16 μg/g and 1.18 μg/g respectively. The concentration of Der f1 & Der p1 in air was higher after the air-conditioners starting one hours later, and the difference was significant (P<0.05, respectively). Additionally, dot-ELISA findings revealed that the allergen extracted from the dust was capable of reacting with IgE from the sera of asthma mice allergic to dust mites. The study concludes that air-conditioner filters can enrich dust mites major group allergen, and the allergens can induce asthma. The air-conditioner filters shall be cleaned or replaced regularly to prevent or reduce accumulation of the dust mites and its allergens. PMID:26064381

  10. Inactivation of dust mites, dust mite allergen, and mold from carpet.

    PubMed

    Ong, Kee-Hean; Lewis, Roger D; Dixit, Anupma; MacDonald, Maureen; Yang, Mingan; Qian, Zhengmin

    2014-01-01

    Carpet is known to be a reservoir for biological contaminants, such as dust mites, dust mite allergen, and mold, if it is not kept clean. The accumulation of these contaminants in carpet might trigger allergies or asthma symptoms in both children and adults. The purpose of this study is to compare methods for removal of dust mites, dust mite allergens, and mold from carpet. Carpets were artificially worn to simulate 1 to 2 years of wear in a four-person household. The worn carpets were inoculated together with a common indoor mold (Cladosporium species) and house dust mites and incubated for 6 weeks to allow time for dust mite growth on the carpet. The carpets were randomly assigned to one of the four treatment groups. Available treatment regimens for controlling carpet contaminants were evaluated through a literature review and experimentation. Four moderately low-hazard, nondestructive methods were selected as treatments: vacuuming, steam-vapor, Neem oil (a natural tree extract), and benzalkonium chloride (a quaternary ammonium compound). Steam vapor treatment demonstrated the greatest dust mite population reduction (p < 0.05) when compared to other methods. The two physical methods, steam vapor and vacuuming, have no statistically significant efficacy in inactivating dust mite allergens (p = 0.084), but have higher efficacy when compared to the chemical method on dust mite allergens (p = 0.002). There is no statistically significant difference in the efficacy for reducing mold in carpet (p > 0.05) for both physical and chemical methods. The steam-vapor treatment effectively killed dust mites and denatured dust mite allergen in the laboratory environment. PMID:24467247

  11. Inactivation of dust mites, dust mite allergen, and mold from carpet.

    PubMed

    Ong, Kee-Hean; Lewis, Roger D; Dixit, Anupma; MacDonald, Maureen; Yang, Mingan; Qian, Zhengmin

    2014-01-01

    Carpet is known to be a reservoir for biological contaminants, such as dust mites, dust mite allergen, and mold, if it is not kept clean. The accumulation of these contaminants in carpet might trigger allergies or asthma symptoms in both children and adults. The purpose of this study is to compare methods for removal of dust mites, dust mite allergens, and mold from carpet. Carpets were artificially worn to simulate 1 to 2 years of wear in a four-person household. The worn carpets were inoculated together with a common indoor mold (Cladosporium species) and house dust mites and incubated for 6 weeks to allow time for dust mite growth on the carpet. The carpets were randomly assigned to one of the four treatment groups. Available treatment regimens for controlling carpet contaminants were evaluated through a literature review and experimentation. Four moderately low-hazard, nondestructive methods were selected as treatments: vacuuming, steam-vapor, Neem oil (a natural tree extract), and benzalkonium chloride (a quaternary ammonium compound). Steam vapor treatment demonstrated the greatest dust mite population reduction (p < 0.05) when compared to other methods. The two physical methods, steam vapor and vacuuming, have no statistically significant efficacy in inactivating dust mite allergens (p = 0.084), but have higher efficacy when compared to the chemical method on dust mite allergens (p = 0.002). There is no statistically significant difference in the efficacy for reducing mold in carpet (p > 0.05) for both physical and chemical methods. The steam-vapor treatment effectively killed dust mites and denatured dust mite allergen in the laboratory environment.

  12. Seasonal dynamics and distribution of house dust mites in China.

    PubMed

    Feng, Meng; Sun, Wenwen; Cheng, Xunjia

    2009-12-01

    House dust mites are widely distributed in the human habitat and work environment and produce very powerful allergens. The most important allergy-causing mites found in homes worldwide are the house dust mites Dermatophagoides farinae and D. pteronyssinus and the storage mite Blomia tropicalis. It is important to know which mite species are present in a geographical area when performing diagnostic testing and prescribing immunotherapy. We classified the breeding situations of house dust mites in dwellings in northern China. Mites are detectable in March and their number increases from April or May, reaching a peak from July to September. The seasonal distribution of different acaroid mite species may differ: temperature, humidity, and eating habits were the major limiting factors determining species composition and diversity of acaroid mite communities in house ecosystems; comparing to the field and the forest, in human living area including house and working place, acaroid mites showed less bio-diversity.

  13. [House-dust mites as vectors of human diseases].

    PubMed

    Hoffmann, G

    1982-01-01

    The genuine European house-dust mite, Dermatophagoides pteronyssinus, is the producer of the most common and most potent allergen in the house-dust in Central Europe. Such allergens causing asthma, rhinitis, tracheitis, bronchitis and/or conjunctivitis in man may also be produced by the other species of house-dust mites such as D. farinae and Euroglyphus maynei. House mites and mites of stored products rarely account for such diseases but more frequently for acarodermatitis--especially on farms. Allergies due to house-dust mites mainly occur in midsummer and in early autumn. Particularly children under 10 years of age are effected by these allergies. Textile articles such as mattresses, upholstered furniture and carpets are breeding places of the genuine house-dust mites. Skin scales of humans, mammals and birds affected by mould provide the nutritional substrate of the mites.

  14. Immunomodulation of Skin Cytokine Secretion by House Dust Mite Extracts

    PubMed Central

    Arlian, Larry G.; Morgan, Marjorie S.

    2011-01-01

    Background Skin contact with house dust mites may contribute to atopic dermatitis and other skin diseases. We sought to determine if molecules from house dust mites could influence the release of proinflammatory cytokines and chemokines from epidermal keratinocytes and dermal fibroblasts grown in a human skin equivalent (HSE) model. Methods HSEs consisting of an epidermis of keratinocytes with stratum corneum over a dermis of fibroblasts in a collagen matrix were challenged with Dermatophagoides farinae, D. pteronyssinus and Euroglyphus maynei mite extracts. Results HSEs secreted interleukin (IL)-1α, IL-1 receptor antagonist, IL-6, IL-8, cutaneous T cell-attracting chemokine, transforming growth factor-α, granulocyte/macrophage and macrophage colony-stimulating factors and vascular endothelial cell growth factor in response to at least 1 mite extract. Extracts of different mite species stimulated HSEs to release different cytokines. Therefore, extracts of different species contained different molecules or different concentrations of similar molecules. The cytokine release profiles of cells in the HSEs were not the same as for monocultured keratinocytes and fibroblasts. Conclusions Molecules from house dust mites are capable of inducing the release of multiple proinflammatory cytokines and chemokines from epidermal keratinocytes and dermal fibroblasts. Avoiding skin contact with house dust mites would reduce the possibility of mite-induced inflammation in the skin. Therefore, measures to reduce contact with mite molecules such as frequent vacuuming of upholstered furniture and carpets and laundering of clothing and bedding to remove mite molecules and allergens could reduce skin contact with mite molecules and diminish exacerbations of skin inflammation in patients with atopic dermatitis and other skin diseases. PMID:21576987

  15. Do other components of bedding dust affect sensitisation to house dust mites?

    PubMed

    Smith, Claire; Stanley, Thorsten; Crane, Julian; Siebers, Robert

    2011-01-01

    Bedding dust is a mixture of many components, of which the house dust mite (HDM) allergen, Der p 1, is the most allergenic. There has been little work to investigate the effect of other bedding dust components on HDM sensitisation. The objective of the study was to determine the effect of endotoxin in bedding dust on the allergic response in HDM-sensitised individuals. Twenty-nine house dust mite-sensitised adults were skin prick and allergen patch tested against a sterile solution of their own bedding dust and against a solution containing the same concentration of Der p 1 as the bedding solution for comparison. There was no significant difference in wheal size between the diluted house dust mite solution and the bedding dust in spite of their high levels of endotoxin. Symptomatic subjects had larger, but not statistically significant, responses to commercial house dust mite solution than asymptomatic subjects. Allergen patch test responses were negative in 22/29 of subjects using either bedding dust solutions or comparable diluted house dust mite solutions. An individual's own bedding dust does not appear to contain factors that enhance skin prick test or atopy patch test responses to house dust mites.

  16. House dust mite allergy: environment evaluation and disease prevention

    PubMed Central

    Yu, Sheng-Jie; Liao, En-Chih

    2014-01-01

    There are two groups of dust mites, house dust mites (HDMs) and storage mites (SMs), that have been identified in the household environment. Both could induce airway inflammation through activation of innate and adaptive immunity and lead to asthma. In order to monitor environmental dust mite infestation, different methods can be used to detect their presence, such as the use of floating methods, monoclonal antibodies, and nanostructured biosensor. SM could be identified in the storage room, mainly in contaminated food such as mushrooms and corn starch. In HDM-sensitive subjects and mice that were challenged with HDM or SM after sensitization, these mites could up-regulate IgE levels, T helper 2 associated cytokine production and airway hypersensitivity. Different age groups of subjects were sensitized by different species of mites. More subjects above 70 years were sensitized by SM and more subjects below the age of 40 years were sensitized to HDM. Different allergenic components of dust mite extracts, such as Der p 1, Der p 2, could activate innate immunity through activating pattern recognition receptor (PRR) and then lead to allergic inflammation. The best modality to treat HDM allergy is immunomodulation through Treg cells and IgA production. In the recent years, many studies indicated probiotics could increase IgA secretion and the number of Treg cells. However, some studies conducted in adults have contradictory effects in reducing allergic symptoms. Therefore, probiotics confer inconclusive benefits on the allergic symptoms. PMID:25379484

  17. Group V secretory phospholipase A2 reveals its role in house dust mite-induced allergic pulmonary inflammation by regulation of dendritic cell function

    PubMed Central

    Giannattasio, Giorgio; Fujioka, Daisuke; Xing, Wei; Katz, Howard R.; Boyce, Joshua A.; Balestrieri, Barbara

    2010-01-01

    We have previously shown that group V secretory phospholipase A2 (sPLA2) regulates phagocytosis of zymosan and Candida albicans by a mechanism that depends on fusion of phagosomes with late endosomes in macrophages. Here we report that group V sPLA2 (Pla2g5)-null mice exposed to an extract of house dust mite Dermatophagoides farinae (Df) had markedly reduced pulmonary inflammation and goblet cell metaplasia compared to wild-type (WT) mice. Pla2g5-null mice had also impaired Th2-type adaptive immune responses to Df compared to WT mice. Pla2g5-null bone marrow-derived dendritic cells (BMDCs) activated by Df had delayed intracellular processing of allergen and impaired allergen-dependent maturation, a pattern recapitulated by the native lung DCs of Df-challenged mice. Adoptively transferred Df-loaded Pla2g5-null BMDCs were less able than Df-loaded WT BMDCs to induce pulmonary inflammation and Th2 polarization in WT mice. However, Pla2g5-null recipients transferred with WT or Pla2g5-null Df-loaded BMDCs exhibited significantly reduced local inflammatory responses to Df, even though the transfer of WT BMDCs still induced an intact Th2 cytokine response in regional lymph nodes. Thus, the expression of group V sPLA2 in APC regulates Ag processing and maturation of dendritic cells, and contributes to pulmonary inflammation and immune response against Df. Furthermore, an additional yet to be identified resident cell type is essential for the development of pulmonary inflammation, likely a cell in which group V sPLA2 is upregulated by Df and whose function is also regulated by group V sPLA2. PMID:20817863

  18. Tropomyosin sensitization in house dust mite allergic patients.

    PubMed

    Becker, Sven; Gröger, Moritz; Canis, Martin; Pfrogner, Elisabeth; Kramer, Matthias F

    2012-04-01

    The growing popularity and frequency of consumption of seafood is accompanied by an increasing number of adverse reactions reported in literature. Allergic reactions to seafood can generate a variety of symptoms ranging from a mild oral allergy syndrome to keen anaphylactic reactions. Tropomyosin, the major shellfish allergen is regarded to be responsible for clinical cross-reactivity to inhaled house dust mites. The aim of the study was to investigate the prevalence of sensitization to tropomyosin in house dust mite allergic patients in southern Bavaria and to compare the results with allergic symptoms. Sera of house dust mite allergic patients (positive skin prick test, allergen-specific IgE and intranasal provocation) were screened for IgE antibodies to tropomyosin (Der p 10). Patients were contacted by phone to evaluate allergic symptoms when consuming seafood. IgE antibodies to house dust mite tropomyosin (Der p 10) could be found in 4 out of 93 sera (4.3%). Two of these four patients (50%) showed itching and swelling of oral mucosa accompanied by bronchial obstruction after consumption of shrimp. Two patients had no problems when eating seafood. None of the seronegative patients complained about any health problems during or after consumption of seafood. In conclusion, cross-reactivity to tropomyosin in house dust mite allergic patients in southern Bavaria, Germany is rarer than suspected. Beside the direct allergic reactions, a further part of reactions to seafood must therefore be ascribed to other mechanisms such as intoxication or intolerance to, e.g. additives in the food product.

  19. Mold populations and dust mite allergen concentrations in house dust samples from across Puerto Rico.

    PubMed

    Vesper, Stephen; Choi, Hyunok; Perzanowski, Matthew S; Acosta, Luis M; Divjan, Adnan; Bolaños-Rosero, Benjamin; Rivera-Mariani, Felix; Chew, Ginger L

    2016-01-01

    Lifetime childhood asthma prevalence (LCAP) percentages in Puerto Rico Health Regions (HR) are substantially higher in northeastern vs. southwestern HR. Higher average relative humidity in the northeast might promote mold and mite exposures and possibly asthma prevalence. To test this hypothesis, mold contamination, Environmental Relative Moldiness Index (ERMI) values were measured in floor dust (n = 26) and dust mite allergen concentrations in bed dust (n = 14). For this analysis, the eight HR were divided into those with LCAP > 30% (n = 3) and <  30% (n = 5). The average ERMI value was significantly greater (Wilcoxon Rank Sum, p < 0.001) in high than in low LCAP HR (14.5 vs. 9.3). The dust mite antigens Der p 1, Der f 1, and Blo t 5 were detected in 90% of bed samples, but the concentrations were not significantly different in high vs. low LCAP HR. Mold exposures might partially explain the differences in LCAP HR in Puerto Rico.

  20. Mold populations and dust mite allergen concentrations in house dust samples from across Puerto Rico

    PubMed Central

    Vesper, Stephen; Choi, Hyunok; Perzanowski, Matthew S.; Acosta, Luis M.; Divjan, Adnan; Bolaños-Rosero, Benjamin; Rivera-Mariani, Felix; Chew, Ginger L.

    2016-01-01

    Lifetime childhood asthma prevalence (LCAP) percentages in Puerto Rico Health Regions (HR) are substantially higher in northeastern vs. southwestern HR. Higher average relative humidity in the northeast might promote mold and mite exposures and possibly asthma prevalence. To test this hypothesis, mold contamination, Environmental Relative Moldiness Index (ERMI) values were measured in floor dust (n = 26) and dust mite allergen concentrations in bed dust (n = 14). For this analysis, the eight HR were divided into those with LCAP > 30 % (n = 3) and < 30 % (n = 5). The average ERMI value was significantly greater (Wilcoxon Rank Sum, p < 0.001) in high than in low LCAP HR (14.5 vs. 9.3). The dust mite antigens Der p 1, Der f 1, and Blo t 5 were detected in 90 % of bed samples, but the concentrations were not significantly different in high vs. low LCAP HR. Mold exposures might partially explain the differences in LCAP HR in Puerto Rico. PMID:26412677

  1. A house dust mite allergen homologue from poultry red mite Dermanyssus gallinae (De Geer).

    PubMed

    Nisbet, A J; Huntley, J F; Mackellar, A; Sparks, N; McDevitt, R

    2006-08-01

    Tropomyosin is an allergenic, actin-binding protein and a proposed vaccine candidate from several species of parasite. Tropomyosin cDNA, obtained by polymerase chain reaction (PCR) amplification from Dermanyssus gallinae RNA, encoded a predicted protein with 89% and 88% identity to tropomyosins from the ticks Boophilus microplus and Haemaphysalis longicornis, respectively, and 85% identity to the house dust mite (HDM) tropomyosin Der p 10. Mouse antibodies raised against HDM tropomyosin reacted with a band of 38 kDa on Western blots of D. gallinae extract, consistent with the molecular masses of acarine tropomyosins and the putative product of the cDNA encoding D. gallinae tropomyosin. When the same preparation of D. gallinae proteins was used in Western blots with serum from infested hens, the IgY component of the serum bound to a number of mite proteins, but not to tropomyosin, indicating that hens are not directly exposed to this allergen during a natural infestation. Immunolocalization of tropomyosin in mites indicated a ubiquitous distribution of the molecule in mite tissues. Immunolocalization and Western blotting also indicated that poultry red mites ingest host IgY.

  2. [Mites in mattress dust and relevant environmental factors in student dormitories in Shenzhen].

    PubMed

    Wang, Bin; Wu, Jie; Liu, Zhi-gang; Ran, Pi-xin; Gao, Qiao; Luo, Chun-hui; Ai, Mei

    2009-02-28

    Three hundred and eight mattress dust samples were collected from college dormitories in Shenzhen with a mite prevalence of 88% (271/308). From the samples, 6163 mites were isolated and identified. Dermatophagoides farinae, D. pteronyssinus and Blomia tropicalis were three most abundant species, occupying 29.7%, 21.7% and 17.9%, respectively. It was found that sex of the students, mattress cover (bamboo mat or bed sheet), with or without air conditioner installation, and daily using of air conditioner (<2 h, 2-8 h and >8 h) had no significant influence on the mite prevalence (P>0.05). However, logistic regression analysis revealed that the risk of mite sensitization in male student dormitory was significantly lower than that in female dormitory (OR=0.55, P=0.038), and the risk of using bed sheets was significantly higher than using bamboo mats (OR=2.13, P=0.040). Both mite prevalence and the risk of mite sensitization significantly decreased with higher floor of the dormitory building. PMID:19459513

  3. Improvement of shrimp allergy after sublingual immunotherapy for house dust mites: a case report.

    PubMed

    Cortellini, G; Spadolini, I; Santucci, A; Cova, V; Conti, C; Corvetta, A; Passalacqua, G

    2011-10-01

    The appropriateness of house dust mite specific immunotherapy in patients allergic to shrimps still remains unclear We present a clinical case as an immunological model for the strong sensitization to tropomyosin with symptoms of anaphylaxis due to shrimps and coexisting asthma due to house dust mite. The improvement in respiratory symptoms for house dust mite and in the food challenge for shrimps during mite immunotherapy with a known and high dosage of tropomyosin suggests the hypothesis that efficacy of mite immunotherapy in food allergy to tropomyosin may be dose dependent.

  4. Shellfish and House Dust Mite Allergies: Is the Link Tropomyosin?

    PubMed

    Wong, Lydia; Huang, Chiung Hui; Lee, Bee Wah

    2016-03-01

    Crustacean shellfish allergy is an important cause of food allergy and anaphylaxis in Asia. The major allergen in shellfish allergy is tropomyosin, a pan-allergen that is also found in house dust mites and cockroaches. Tropomyosins from house dust mites (HDMs) have a high sequence homology to shellfish tropomyosins, and cross-reactivity between HDM and shrimp tropomyosins has been demonstrated. Exposure to inhaled tropomyosins from house dust mites has been postulated to be the primary sensitizer for shellfish allergy, in a reaction analogous to the oral allergy (inhalant-food) syndrome. This notion is supported by indirect data from the effects of HDM immunotherapy on shellfish allergy, and strong correlations of shellfish and HDM sensitization. HDM immunotherapy has been reported to induce both shrimp allergy in non-allergic patients and shrimp tolerance in shrimp-allergic patients. Epidemiological surveys have also demonstrated a strong correlation between shellfish and HDM sensitization in both hospital-based and community-based studies. Unexposed populations have also been shown to develop sensitization-shellfish sensitization in orthodox Jews with no history of shellfish consumption was associated with HDM sensitization. Reciprocally, HDM sensitization in an Icelandic population living in a HDM-free environment was associated with shrimp sensitization. In vitro IgE inhibition studies on sera in shrimp-allergic Spanish patients indicate that mites are the primary sensitizer in shrimp-allergic patients living in humid and warm climates. Current data supports the hypothesis that tropomyosin is the link between HDM and shellfish allergies. The role of tropomyosin in HDM and shellfish allergies is a fertile field for investigation as it may provide novel immunotherapeutic strategies for shellfish allergy.

  5. Shellfish and House Dust Mite Allergies: Is the Link Tropomyosin?

    PubMed Central

    Wong, Lydia; Huang, Chiung Hui

    2016-01-01

    Crustacean shellfish allergy is an important cause of food allergy and anaphylaxis in Asia. The major allergen in shellfish allergy is tropomyosin, a pan-allergen that is also found in house dust mites and cockroaches. Tropomyosins from house dust mites (HDMs) have a high sequence homology to shellfish tropomyosins, and cross-reactivity between HDM and shrimp tropomyosins has been demonstrated. Exposure to inhaled tropomyosins from house dust mites has been postulated to be the primary sensitizer for shellfish allergy, in a reaction analogous to the oral allergy (inhalant-food) syndrome. This notion is supported by indirect data from the effects of HDM immunotherapy on shellfish allergy, and strong correlations of shellfish and HDM sensitization. HDM immunotherapy has been reported to induce both shrimp allergy in non-allergic patients and shrimp tolerance in shrimp-allergic patients. Epidemiological surveys have also demonstrated a strong correlation between shellfish and HDM sensitization in both hospital-based and community-based studies. Unexposed populations have also been shown to develop sensitization-shellfish sensitization in orthodox Jews with no history of shellfish consumption was associated with HDM sensitization. Reciprocally, HDM sensitization in an Icelandic population living in a HDM-free environment was associated with shrimp sensitization. In vitro IgE inhibition studies on sera in shrimp-allergic Spanish patients indicate that mites are the primary sensitizer in shrimp-allergic patients living in humid and warm climates. Current data supports the hypothesis that tropomyosin is the link between HDM and shellfish allergies. The role of tropomyosin in HDM and shellfish allergies is a fertile field for investigation as it may provide novel immunotherapeutic strategies for shellfish allergy. PMID:26739402

  6. Shellfish and House Dust Mite Allergies: Is the Link Tropomyosin?

    PubMed

    Wong, Lydia; Huang, Chiung Hui; Lee, Bee Wah

    2016-03-01

    Crustacean shellfish allergy is an important cause of food allergy and anaphylaxis in Asia. The major allergen in shellfish allergy is tropomyosin, a pan-allergen that is also found in house dust mites and cockroaches. Tropomyosins from house dust mites (HDMs) have a high sequence homology to shellfish tropomyosins, and cross-reactivity between HDM and shrimp tropomyosins has been demonstrated. Exposure to inhaled tropomyosins from house dust mites has been postulated to be the primary sensitizer for shellfish allergy, in a reaction analogous to the oral allergy (inhalant-food) syndrome. This notion is supported by indirect data from the effects of HDM immunotherapy on shellfish allergy, and strong correlations of shellfish and HDM sensitization. HDM immunotherapy has been reported to induce both shrimp allergy in non-allergic patients and shrimp tolerance in shrimp-allergic patients. Epidemiological surveys have also demonstrated a strong correlation between shellfish and HDM sensitization in both hospital-based and community-based studies. Unexposed populations have also been shown to develop sensitization-shellfish sensitization in orthodox Jews with no history of shellfish consumption was associated with HDM sensitization. Reciprocally, HDM sensitization in an Icelandic population living in a HDM-free environment was associated with shrimp sensitization. In vitro IgE inhibition studies on sera in shrimp-allergic Spanish patients indicate that mites are the primary sensitizer in shrimp-allergic patients living in humid and warm climates. Current data supports the hypothesis that tropomyosin is the link between HDM and shellfish allergies. The role of tropomyosin in HDM and shellfish allergies is a fertile field for investigation as it may provide novel immunotherapeutic strategies for shellfish allergy. PMID:26739402

  7. Water balance and humidity requirements of house dust mites.

    PubMed

    Arlian, L G

    1992-11-01

    The house dust mites, Dermatophagoides farinae, D. pteronyssinus and Euroglyphus maynei, are prevalent in homes in humid geographical areas throughout the world. These mites thrive in humid environments in human dwellings where there is no liquid water to drink. However, their bodies contain 70-75% water by weight, which must be maintained in order to reproduce. Their primary source of water is water vapor which is actively extracted from unsaturated air. At relative humidities above 65-70%, adequate amounts of water can be extracted from unsaturated air to compensate for that lost by all avenues. Active uptake is associated with ingestion of a hyperosmotic solution which is secreted by the supracoxal glands. Active mites do not survive longer than 6-11 days at RHs < or = 50%. They survive extended dry periods by forming a desiccation-resistant protonymphal stage which can survive for months at RHs below the critical humidity for active stages. Feeding rate and allergen production is directly influenced by RH. Mites feed, multiply, and produce more fecal matter at higher RHs than at lower ones.

  8. Ventilation in homes infested by house-dust mites.

    PubMed

    Sundell, J; Wickman, M; Pershagen, G; Nordvall, S L

    1995-02-01

    Thirty single-family homes with either high (> or = 2000 ng/g) or low (< or = 1000 ng/g) house-dust mite (HDM) allergen levels in mattress dust were examined for ventilation, thermal climate, and air quality (formaldehyde and total volatile organic compounds (TVOC). Elevated concentrations of HDM allergen in mattress and floor dust were associated with the difference in absolute humidity between indoor and outdoor air, as well as with low air-change rates of the home, particularly the bedroom. No correlation was found between concentration of TVOC or formaldehyde in bedroom air and HDM allergen concentration. In regions with a cold winter climate, the air-change rate of the home and the infiltration of outdoor air into the bedroom appear to be important for the infestation of HDM.

  9. Effectiveness of vacuum cleaning and wet cleaning in reducing house-dust mites, fungi and mite allergen in a cotton carpet: a case study.

    PubMed

    Wassenaar, D P

    1988-02-01

    In order to evaluate the effect of continuous, thorough vacuuming on house dust organisms and mite allergen, a cotton carpet was vacuumed every other day, six times in total. Seven weeks later, the carpet was cleaned by means of spray extraction. Samples were taken before and after this wet cleaning. In total 1150 g of dust was collected, containing approximately 174,000 arthropods (dead and alive) and 9000 X 10(6) fungal spores. In the course of the experiment, the amount of dust collected at each vacuuming decreased. The number of extracted house dust mites did not decrease significantly, but that of the predator mite Cheyletus did. The number of extracted fungal spores showed a significant decrease (from 142 to 16 X 10(6) spores/m2 per minute vacuuming), as did the extracted mite allergen per m2. After 7 weeks the number of mite eggs and complete house dust mites had increased enormously. After cleaning by spray extraction another increase in the number of complete mites and mite eggs was found, while the amount of mite allergen was diminished. The population growth of the house dust mite between the 6th and the 7th vacuuming is probably due to the decrease of their most important predator, Cheyletus. After the wet cleaning a number of extra eggs hatched, probably due to the high humidity in the carpet. The procedures used in this study to combat house dust mites may have an adverse effect in the long run. PMID:3378462

  10. Effects of physical interventions on house dust mite allergen levels in carpet, bed, and upholstery dust in low-income, urban homes.

    PubMed

    Vojta, P J; Randels, S P; Stout, J; Muilenberg, M; Burge, H A; Lynn, H; Mitchell, H; O'Connor, G T; Zeldin, D C

    2001-08-01

    House dust mite allergen exposure is a postulated risk factor for allergic sensitization, asthma development, and asthma morbidity; however, practical and effective methods to mitigate these allergens from low-income, urban home environments remain elusive. The purpose of this study was to assess the feasibility and effectiveness of physical interventions to mitigate house dust mite allergens in this setting. Homes with high levels of house dust mite allergen (Der f 1 + Der p 1 > or = 10 microg/g dust by enzyme-linked immunosorbent assay) in the bed, bedroom carpet, and/or upholstered furniture were enrolled in the study. Carpets and upholstered furniture were subjected to a single treatment of either dry steam cleaning plus vacuuming (carpet only) or intensive vacuuming alone. Bed interventions consisted of complete encasement of the mattress, box spring, and pillows plus either weekly professional or in-home laundering of nonencased bedding. Dust samples were collected at baseline and again at 3 days (carpet and upholstery only) and 2, 4, and 8 weeks posttreatment. We compared pretreatment mean allergen concentrations and loads to posttreatment values and performed between-group analyses after adjusting for differences in the pretreatment means. Both dry steam cleaning plus vacuuming and vacuuming alone resulted in a significant reduction in carpet house dust mite allergen concentration and load (p < 0.05). Levels approached pretreatment values by 4 weeks posttreatment in the intensive vacuuming group, whereas steam cleaning plus vacuuming effected a decrease that persisted for up to 8 weeks. Significant decreases in bed house dust mite allergen concentration and load were obtained in response to encasement and either professional or in-home laundering (p < 0.001). Between-group analysis revealed significantly less postintervention house dust mite allergen load in professionally laundered compared to home-laundered beds (p < 0.05). Intensive vacuuming and dry

  11. Effects of physical interventions on house dust mite allergen levels in carpet, bed, and upholstery dust in low-income, urban homes.

    PubMed

    Vojta, P J; Randels, S P; Stout, J; Muilenberg, M; Burge, H A; Lynn, H; Mitchell, H; O'Connor, G T; Zeldin, D C

    2001-08-01

    House dust mite allergen exposure is a postulated risk factor for allergic sensitization, asthma development, and asthma morbidity; however, practical and effective methods to mitigate these allergens from low-income, urban home environments remain elusive. The purpose of this study was to assess the feasibility and effectiveness of physical interventions to mitigate house dust mite allergens in this setting. Homes with high levels of house dust mite allergen (Der f 1 + Der p 1 > or = 10 microg/g dust by enzyme-linked immunosorbent assay) in the bed, bedroom carpet, and/or upholstered furniture were enrolled in the study. Carpets and upholstered furniture were subjected to a single treatment of either dry steam cleaning plus vacuuming (carpet only) or intensive vacuuming alone. Bed interventions consisted of complete encasement of the mattress, box spring, and pillows plus either weekly professional or in-home laundering of nonencased bedding. Dust samples were collected at baseline and again at 3 days (carpet and upholstery only) and 2, 4, and 8 weeks posttreatment. We compared pretreatment mean allergen concentrations and loads to posttreatment values and performed between-group analyses after adjusting for differences in the pretreatment means. Both dry steam cleaning plus vacuuming and vacuuming alone resulted in a significant reduction in carpet house dust mite allergen concentration and load (p < 0.05). Levels approached pretreatment values by 4 weeks posttreatment in the intensive vacuuming group, whereas steam cleaning plus vacuuming effected a decrease that persisted for up to 8 weeks. Significant decreases in bed house dust mite allergen concentration and load were obtained in response to encasement and either professional or in-home laundering (p < 0.001). Between-group analysis revealed significantly less postintervention house dust mite allergen load in professionally laundered compared to home-laundered beds (p < 0.05). Intensive vacuuming and dry

  12. The prevalence of house dust mites, Dermatophagoides spp, and associated environmental conditions in homes in Ohio.

    PubMed

    Arlian, L G; Bernstein, I L; Gallagher, J S

    1982-06-01

    Abundance of the house dust mites, Dermatophagoides farinae and D. pteronyssinus, in various sites in the homes of dust-sensitive patients was sequentially monitored at approximately 3 wk intervals for 2 yr, and mite density was correlated with indoor physical and climatic factors. Significantly higher mite levels occurred on the most heavily used fabric-upholstered furniture and carpeted floor areas of the living/family room and bedrooms. Mattresses were not found to be the major foci for mites. No significant positive correlation was noted between mite abundance and frequency or thoroughness of cleaning, amount of dust, and age of furnishings or dwelling. Significantly higher mite levels occurred on carpeted floors than on noncarpeted floors. Successive vacuuming did not significantly reduce mite abundance. Mite density exhibited a seasonal fluctuation, with highest density occurring in the humid summer months and the lowest density during the dryer, late heating season. Live mites were more abundant than dead mites during the period when total abundance was high. In homes inhabited by both species, D. farinae was the dominant species, except in one home that had a significantly higher relative humidity.

  13. Comparative efficacy of house dust mite extermination products.

    PubMed

    Schober, G; Kniest, F M; Kort, H S; De Saint Georges Gridelet, D M; Van Bronswijk, J E

    1992-06-01

    The acaricidal efficacy of nine marketed products, i.e. Acardust, Acarosan (foam and powder), Actelic 50, Artilin 3A (spirit and water base), liquid nitrogen, Paragerm AK, and Tymasil, and of intensive vacuum-cleaning have been compared on four different test surfaces: mattress, tufted carpet, gypsum board and rough wooden board, all covered with artificial house dust. They were inoculated with the house dust mite, Dermatophagoides pteronyssinus or the house-dust fungus Aspergillus repens for evaluation of the fungistatic claims of some products. The acaricidal activity of Tymasil did not surpass that of vacuuming; its fungistatic effect was not apparent. The other products showed complete to almost complete eradication on at least one of the substrates tested. Taking into account the results of acaricidal efficacy as well as the data on safety and practicality acquired earlier, Acarosan powder was considered first choice for carpet treatment. Acarosan and liquid nitrogen, were found to be effective in the treatment of mattress, pillow, upholstered furniture and heavy curtains. On wooden surfaces Acarosan was found to be both effective and safe, while Acardust, Actelic 50, Artilin 3A (both fungistatic as well as acaricidal), liquid nitrogen and Paragerm also passed the efficiency test.

  14. Dust Mites Population in Indoor Houses of Suspected Allergic Patients of South Assam, India

    PubMed Central

    Sharma, Dhruba; Dutta, B. K.; Singh, A. B.

    2011-01-01

    Background. In the present study, quality and quantity of indoor dust mites was evaluated at the residence of 150 atopic allergic patients from four different districts of South Assam. Methods. Suspected patients with case history of allergic disease were selected for indoor survey. Dust samples (500 mg) were collected from the selected patient's house and were analyzed using standard methods. Results. About 60% of the selected patients were found suffering from respiratory disorders and rest 40% from skin allergy. The dominant mites recorded from indoor dust samples were Dermatophagoides followed by Blomia, Acarus, and Cheyletus while Caloglyphus was recorded in least number. The distribution of mites on the basis of housing pattern indicates that RCC type of buildings supports maximum dust mite's population followed by Assam type (semi-RCC) buildings, and the lowest count was observed in wooden houses. Environmental factors like temperature, rainfall, and relative humidity are found to determine the indoor mite's population. Severity of allergic attack in some of the typical cases was found to be proportional to the allergen load of mites in the dust samples. Conclusions. The economic status, housing pattern, and local environmental factors determine the diversity and abundance of dust mites in indoor environment. PMID:23724231

  15. House dust mite and cat allergen in different indoor environments.

    PubMed

    Custovic, A; Taggart, S C; Woodcock, A

    1994-12-01

    Allergy to house dust mites (HDM) and domestic pets is a major cause of asthma. People in developed countries spend more than 90% of their time indoors. We have measured levels of HDM allergen Der pI and cat allergen Fel dI in public buildings and public transport. Dust samples were collected by vacuuming a 1 m2 area for 2 min from five schools, six hotels, four cinemas, six pubs, three buses, two trains and 12 domestic households without a cat. Der pI and Fel dI were assayed with monoclonal antibodies in a two-site immunometric ELISA. Der pI concentration was significantly higher in the private homes than in comparable sites in public places except for cinema seats (where high values were found) compared with domestic sofas. Der pI > 2000 ng/g of fine dust was found in 30% of the upholstered seats, 9% having a concentration > 10,000 ng/g. Fel dI levels were significantly higher in the dust from upholstered seats (geometric mean 14.88 micrograms/g) than in carpeted floors (geometric mean 0.73 micrograms/g), and in public places than in private homes. Fel dI > 8 micrograms/g was found in 79% of the upholstered seats or furniture sampled in public buildings or public transport. In conclusion, upholstered seats from public buildings and public transport constitute an allergen reservoir for continuous contamination of the indoor environment which could compromise the effects of allergen avoidance employed at home.

  16. House dust-mite allergen exposure is associated with serum specific IgE but not with respiratory outcomes.

    PubMed

    Bakolis, I; Heinrich, J; Zock, J P; Norbäck, D; Svanes, C; Chen, C M; Accordini, S; Verlato, G; Olivieri, M; Jarvis, D

    2015-06-01

    Exposure to house dust has been associated with asthma in adults, and this is commonly interpreted as a direct immunologic response to dust-mite allergens in those who are IgE sensitized to house dust-mite. Mattress house dust-mite concentrations were measured in a population-based sample of 2890 adults aged between 27 and 56 years living in 22 centers in 10 countries. Generalized linear mixed models were employed to explore the association of respiratory symptoms with house dust-mite concentrations, adjusting for individual and household confounders. There was no overall association of respiratory outcomes with measured house dust-mite concentrations, even in those who reported they had symptoms on exposure to dust and those who had physician-diagnosed asthma. However, there was a positive association of high serum specific IgE levels to HDM (>3.5 kUA /l) with mattress house dust-mite concentrations and a negative association of sensitization to cat with increasing house dust-mite concentrations. In conclusion, there was no evidence that respiratory symptoms in adults were associated with exposure to house dust-mite allergen in the mattress, but an association of house mite with strong sensitization was observed.

  17. Innate Immune Responses in House Dust Mite Allergy

    PubMed Central

    Jacquet, Alain

    2013-01-01

    Sensitizations to house dust mites (HDM) trigger strong exacerbated allergen-induced inflammation of the skin and airways mucosa from atopic subjects resulting in atopic dermatitis as well as allergic rhinitis and asthma. Initially, the Th2-biased HDM allergic response was considered to be mediated only by allergen B- and T-cell epitopes to promote allergen-specific IgE production as well as IL-4, IL-5, and IL-13 to recruit inflammatory cells. But this general molecular model of HDM allergenicity must be revisited as a growing literature suggests that stimulations of innate immune activation pathways by HDM allergens offer new answers to the following question: what makes an HDM allergen an allergen? Indeed, HDM is a carrier not only for allergenic proteins but also microbial adjuvant compounds, both of which are able to stimulate innate signaling pathways leading to allergy. This paper will describe the multiple ways used by HDM allergens together with microbial compounds to control the initiation of the allergic response through engagement of innate immunity. PMID:23724247

  18. Occurrence of Respiratory Symptoms Resulting from Exposure to House Dust Mites in Early Childhood

    ERIC Educational Resources Information Center

    Jedrychowski, Wieslaw; Maugeri, Umberto; Zembala, Marek; Hajto, Barbara; Flak, Elzbieta; Mroz, Elzbieta; Jacek, Ryszard; Sowa, Agata; Perera, Frederica P.

    2009-01-01

    The aim of the study was to describe the distribution of house dust mite (HDM) allergens within homes of three-year-old children, to identify factors responsible for its variation and to test the hypothesis whether the content of HDM allergens exceeding 2 [mu]g/g dust may be regarded as a risk level of sensitization possibly affecting respiratory…

  19. Hierarchy and molecular properties of house dust mite allergens.

    PubMed

    Thomas, Wayne R

    2015-10-01

    The allergenic load of house dust mite allergy is largely constituted by a few proteins with a hierarchical pattern of allergenicity. The serodominant specificities are the group 1&2 and the group 23 faecal allergens. The collective IgE binding to the group 1&2 allergens can measure unequivocal HDM sensitisation better than HDM extracts although discrepancies have been found in regions with complex acarofauna suggesting a need to investigate the specificity with allergen components. The group 4, 5, 7&21 allergens that each induce responses in about 40% of subjects are mid-tier allergens accounting for most of the remaining IgE binding. Their titres are proportional to the concomitant responses to Der p1&2. Group 2 allergen variants have different antibody binding. Body proteins only occasionally induce sensitisation although a higher prevalence of binding by atopic dermatitis patients provides a new avenue of research. A broad spectrum of IgE binding has been associated with diverse symptoms but not with the severity of asthma which is associated with low IgG antibody. Some allergens such as the group 14 large lipid binding proteins and the recently described proteins Der f 24-33, need further investigation but with the cognoscence that other denominated allergens have been found to be minor sensitisers by comparative quantitative analyses. Scabies is a confounder for diagnosis with extracts, inducing cross-reactive antibodies with Der p 4&20 as is seafood allergy with cross reactivity to Der p 10 a minor HDM allergen. The HDM genome sequence can now be used to verify allelic and paralogous variations. PMID:26433526

  20. The role of water temperature and laundry procedures in reducing house dust mite populations and allergen content of bedding.

    PubMed

    McDonald, L G; Tovey, E

    1992-10-01

    The effects of various laundry procedures on house dust mites and their allergens have been established. All mites were killed by water temperatures 55 degrees C or greater. Killing at lower temperatures was not enhanced by any of the pure detergents or laundry products tested. A cold cycle of laundry washing with or without laundry powder did not remove most live mites from bedding, however, the allergen concentration (Der p I/gm fine dust) was reduced by more than 90%. Dry cleaning did not reduce the allergen concentration of the dust, although most, if not all, mites were killed.

  1. The effect of sub-floor heating on house-dust-mite populations on floors and in furniture.

    PubMed

    de Boer, Rob

    2003-01-01

    It is well known that dehydrating conditions for house dust mites can be created by simply raising the temperature, causing loss of body water and eventually death. Thus, it can be expected that conditions for dust mites are less favourable on floors supplied with sub-floor heating. This was examined in a study of 16 houses with sub-floor heating and 21 without. The pattern of changes in air humidity and temperature on the floors was investigated and compared to known data of the tolerance of dust mites. Also the resident mite populations were compared. Floors with sub-floor heating had, on average, fewer mites, but the difference with unheated floors was small. It was remarkable that mite numbers were also lower in upholstered furniture. Another important observation was that some houses with sub-floor heating had high mite numbers, indicating that this type of heating is compatible with a thriving mite population. Temperature and humidity conditions of heated floors may allow mites not only to survive, but also to remain active in winter. A moderate increase in temperature, a moderate decrease in (absolute) air humidity, or a combination of both, will suffice to keep the humidity all winter below the Critical Equilibrium Humidity, the level of air humidity that is critical for mite growth and reproduction, hence for allergen production. However, it is argued that measures to suppress allergen production by house dust mites are likely to be far more effective if taken in summer rather than in winter.

  2. Inert dusts and their effects on the poultry red mite (Dermanyssus gallinae).

    PubMed

    Kilpinen, Ole; Steenberg, Tove

    2009-06-01

    The haematophagous poultry red mite (Dermanyssus gallinae) is the most important pest of egg laying hens in many parts of the world. Control has often relied on chemical pesticides, but inert dusts, which are thought to kill target hosts primarily by desiccation, have become one of the most commonly applied alternative control methods for poultry red mite in Europe. This development has occurred despite a lack of knowledge of the efficacy of the different types of inert dusts and how this is affected by environmental parameters, e.g. the high relative humidity found in poultry houses. In this laboratory study the efficacy of different commercial inert dust products against D. gallinae is compared. All tested compounds killed mites, but there was a clear ranking of efficacy (measured as weight loss after 24 h and as time until 50% mortality), particularly at 75% relative humidity (RH). At 85% RH the efficacy was significantly lower for all tested compounds (P < 0.001). Weight changes over time followed an exponential evaporation model until the mites started dying whereafter the rate of evaporation increased again and followed a slightly different exponential evaporation model. A tarsal test showed that 24 h exposure to surfaces treated with doses much lower than those recommended by the producers is sufficient to kill mites as fast as when they were dusted with massive doses. These data emphasise the need for thorough treatment of all surfaces in a poultry house in order to combat D. gallinae.

  3. Dose of house dust mite antigen (P1) inhaled by infants aged one month

    SciTech Connect

    Carswell, F.; Clark, J.; Robinson, P.; Platts-Mills, T.A.

    1983-11-01

    A survey of the habitats occupied by 12 infants of one month of age revealed that approximately 10% of their day was spent in conditions of potential exposure to the major (P1) allergen of the house dust mite, Dermatophagoides pteronyssinus. A respiratory pump which reproduced the minute ventilation of an infant was placed in representative infant habitats. The P1 allergen trapped by the filter in this pump was measured as an estimate of infants' allergen intake. Detectable P1 intake was only present when there was active air disturbance (bed making and vacuuming). The average P1 intake was approximately 3 ng P1/24 hours. Comparison of this P1 intake with that which sensitizes in other situations suggests that it is usually inadequate to sensitize infants.

  4. Mite antigen in house dust: relationship with different housing characteristics in The Netherlands.

    PubMed

    Van Strien, R T; Verhoeff, A P; Brunekreef, B; Van Wijnen, J H

    1994-09-01

    As part of a case-controlled study on the relationship between home dampness and respiratory symptoms of children, the concentration of the major allergen of Dermatophagoides pteronyssinus (Der p I) in floor dust and mattress dust in 516 dwellings in the Netherlands was measured. A checklist, completed by the investigators, was used to obtain information on home and occupant characteristics, which may have an impact on the Der p I concentration in house dust. The geometric mean mite antigen concentrations were 2370 ng Der p I/g floor dust for the living room, 2201 ng Der p I/g floor dust for the bedroom and 5075 ng Der p I/g mattress dust. In 86% of the houses the maximum concentration was higher than 2000 ng Der p I/g dust, that is regarded as representing a risk for genetically predisposed individuals for the development of specific IgE to house dust mite allergen. In 55% of the houses the maximum concentration exceeded 10,000 ng Der p I/g dust, regarded as a risk factor for acute attacks of asthma for mite allergic patients. The Der p I concentrations in dust from carpeted floors were six to 14 times higher than in dust from floors with a smooth floor covering. Higher Der p I concentrations in floor dust were also significantly associated with increasing age of the dwelling and of the floor covering, with an increasing number of occupants, and with the absence of floor insulation. For mattress dust, the age of the mattress, the presence of an outer cavity wall and mechanical ventilation were important factors. Older mattresses had higher levels, and mattress dust from bedrooms with solid brick outer walls had higher levels than that from bedrooms with outer cavity walls. Mattresses in homes with continuous mechanical ventilation had almost twice lower levels than mattresses in homes with natural ventilation. There was a tendency towards higher Der p I concentrations in dust in homes with reported or observed signs of dampness. The Der p I concentrations in dust

  5. Vacuum cleaning decreases the levels of mite allergens in house dust.

    PubMed

    Munir, A K; Einarsson, R; Dreborg, S K

    1993-08-01

    To investigate the capacity of chemical treatment of surfaces and the difference in capacity among common vacuum cleaners to reduce mite allergen content in house dust, we recruited 52 families with allergic children. Ten families used their central vacuum cleaners. Forty-two families were randomly divided into four groups with 10 or 11 families in each. These families used either new vacuum cleaners with either HEPA (High Efficiency Particulate Air) or micro-filters, or their own vacuum cleaners with either tannic acid or placebo. Dust samples were collected from carpets and upholstered furniture in the living rooms and from the mattresses of the children at Days 0, 7, 21, and 35. Der pI and Der fI allergens were determined by sandwich ELISA. After one week, tannic acid reduced the concentration of mite allergens/g of dust and the total amount/sampling area by 30% and 34%, respectively (p < 0.05), but there was no significant decrease in relation to placebo. After 5 weeks, central, HEPA- and micro-filter vacuum cleaners decreased the mite allergen concentration by 10-50% (p < 0.05) and the total amount of mite allergen from the investigated areas by 50-85% (p < 0.01). In relation to the placebo group the decrease was significant for HEPA- and micro-filter vacuums (p < 0.05). The total amount of mite allergens/sampling area was more significantly (p < 0.05) reduced than the concentration/g of dust. We conclude, that tannic acid reduces mite allergen concentrations in dust and total amount/sampling area for a short period of time.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Acaricidal activities against house dust mites of spearmint oil and its constituents.

    PubMed

    Yang, Ji-Yeon; Kim, Min-Gi; Lee, Sung-Eun; Lee, Hoi-Seon

    2014-02-01

    The aim of this study was to evaluate the acaricidal activities of spearmint oil and carvone derivatives against house dust mites using contact and fumigant toxicity bioassays to replace benzyl benzoate as a synthetic acaricide. Based on the LD50 values, the contact toxicity bioassay revealed that dihydrocarvone (0.95 and 0.88 µg/cm2) was 7.7 and 6.8 times more toxic than benzyl benzoate (7.33 and 6.01 µg/cm2) against Dermatophagoides farinae and Dermatophagoides pteronyssinus, respectively, followed by carvone (3.78 and 3.23 µg/cm2), spearmint oil (5.16 and 4.64 µg/cm2), carveol (6.00 and 5.80 µg/cm2), and dihydrocarveol (8.23 and 7.10 µg/cm2). Results of the fumigant toxicity bioassay showed that dihydrocarvone (2.73 and 2.16 µg/cm2) was approximately 4.0 and 4.8 times more effective than benzyl benzoate (11.00 and 10.27 µg/cm2), followed by carvone (6.63 and 5.78 µg/cm2), carveol (7.58 and 7.24 µg/cm2), spearmint oil (9.55 and 8.10 µg/cm2), and dihydrocarveol (9.79 and 8.14 µg/cm2). Taken together, spearmint oil and carvone derivatives are a likely viable alternative to synthetic acaricides for managing house dust mites.

  7. Environmental controls in reducing house dust mites and nasal symptoms in patients with allergic rhinitis.

    PubMed

    Moon, J S; Choi, S O

    1999-06-01

    A randomized comparison group pretest-posttest experimental design was used to quantitatively determine the effects of environmental control measures on patients with allergic rhinitis. Environmental controls included wrapping the mattress with a vinyl cover, washing the top bedding cover with 55 degrees C hot water every two weeks, removal of soft furniture, and wet cleaning of the bedroom floor every day. Thirty subjects were randomly assigned to experimental and control groups. The amount of house dust mites in dust samples collected from the bedroom floor, bedding and mattress, as well as the nasal symptoms of patients, were measured twice at one-month intervals. A significant decrease in house dust mites in dust samples and relief in patients' nasal symptoms were observed in the experimental group who had environmental controls.

  8. House dust mite control measures in the management of asthma: meta-analysis

    PubMed Central

    Gøtzsche, Peter C; Hammarquist, Cecilia; Burr, Michael

    1998-01-01

    Objective To determine whether patients with asthma who are sensitive to mites benefit from measures designed to reduce their exposure to house dust mite antigen in the home. Design Meta-analysis of randomised trials that investigated the effects on asthma patients of chemical or physical measures to control mites, or both, in comparison with an untreated control group. All trials in any language were eligible for inclusion. Subjects Patients with bronchial asthma as diagnosed by a doctor and sensitisation to mites as determined by skin prick testing, bronchial provocation testing, or serum assays for specific IgE antibodies. Main outcome measures Number of patients whose allergic symptoms improved, improvement in asthma symptoms, improvement in peak expiratory flow rate. Outcomes measured on different scales were combined using the standardised effect size method (the difference in effect was divided by the standard deviation of the measurements). Results 23 studies were included in the meta-analysis; 6 studies used chemical methods to reduce exposure to mites, 13 used physical methods, and 4 used a combination. Altogether, 41/113 patients exposed to treatment interventions improved compared with 38/117 in the control groups (odds ratio 1.20, 95% confidence interval 0.66 to 2.18). The standardised mean difference for improvement in asthma symptoms was −0.06 (95% confidence interval −0.54 to 0.41). For peak flow rate measured in the morning the standardised mean difference was −0.03 (−0.25 to 0.19). As measured in the original units this difference between the treatment and the control group corresponds to −3 l/min (95% confidence interval −25 l/min to 19 l/min). The results were similar in the subgroups of trials that reported successful reduction in exposure to mites or had long follow up times. Conclusion Current chemical and physical methods aimed at reducing exposure to allergens from house dust mites seem to be ineffective and cannot be

  9. Can house dust mite-triggered atopic dermatitis be alleviated using acaricides?

    PubMed

    Cameron, M M

    1997-07-01

    House dust mite (HDM) allergens are the most important triggers for atopic dermatitis. Reducing exposure to these allergens may alleviate clinical symptoms. Chemicals with acaricidal activity have been used to treat upholstered furniture, carpets and bedding with the aim to reduce HDM allergen exposure. These chemicals, by reducing HDM, can decrease the concentration of mite allergens in dust but improvements in clinical symptoms are not always apparent. Clinical improvement is more likely to occur if bedding has been treated rather than carpets and upholstery. Future control strategies should be aimed at treating bedding. Permethrin is a very efficient killer of mites. It is used topically to treat scabies and head lice and is impregnated in bed nets to prevent mosquito bites. Even when applied to the skin in high concentrations, it has a very low toxicity in humans and other mammals. Permethrin-impregnated bedding may prove to be the best control method in the treatment of HDM allergen-triggered atopic conditions.

  10. Effect of inhaled dust mite allergen on regional particle deposition and mucociliary clearance in allergic asthmatics**

    EPA Science Inventory

    Background Acute exacerbations in allergic asthmatics may lead to impaired ability to clear mucus from the airways, a key factor in asthma morbidity. Objective The purpose of this study was to determine the effect of inhaled house dust mite challenge on the regional deposition of...

  11. The relative allergenicity of Stachybotrys chartarum compared to house dust mite extracts in a mouse model

    EPA Science Inventory

    A report by the Institute of Medicine suggested that more research is needed to better understand mold effects on allergic disease, particularly asthma development. The authors compared the ability of the fungus Stachybotrys chartarum (SCE) and house dust mite (HDM) extracts to i...

  12. DIESEL AND CARBON PARTICLES ENHANCE HOUSE DUST MITE-INDUCED PULMONARY HYPERSENSITIVITY IN BROWN NORWAY RATS

    EPA Science Inventory

    Diesel and Carbon Particles Enhance House Dust Mite-Induced Pulmonary Hypersensitivity in Brown Norway Rats. P. Singh1, M.J. Daniels2, D. Winsett2, J. Richards2, K. Crissman2, M. Madden2 and M.I. Gilmour2. 1NCSU, Raleigh, NC and 2 USEPA, Research Triangle Park, NC.

    Ep...

  13. Respiratory allergy caused by house dust mites: What do we really know?

    PubMed

    Calderón, Moisés A; Linneberg, Allan; Kleine-Tebbe, Jörg; De Blay, Frédéric; Hernandez Fernandez de Rojas, Dolores; Virchow, Johann Christian; Demoly, Pascal

    2015-07-01

    The house dust mite (HDM) is a major perennial allergen source and a significant cause of allergic rhinitis and allergic asthma. However, awareness of the condition remains generally low. This review assesses the links between exposure to HDM, development of the allergic response, and pathologic consequences in patients with respiratory allergic diseases. We investigate the epidemiology of HDM allergy to explore the interaction between mites and human subjects at the population, individual, and molecular levels. Core and recent publications were identified by using "house dust mite" as a key search term to evaluate the current knowledge of HDM epidemiology and pathophysiology. Prevalence data for HDM allergen sensitization vary from 65 to 130 million persons in the general population worldwide to as many as 50% among asthmatic patients. Heterogeneity of populations, terminology, and end points in the literature confound estimates, indicating the need for greater standardization in epidemiologic research. Exposure to allergens depends on multiple ecological strata, including climate and mite microhabitats within the domestic environment, with the latter providing opportunity for intervention measures to reduce allergen load. Inhaled mite aeroallergens are unusually virulent: they are able to activate both the adaptive and innate immune responses, potentially offering new avenues for intervention. The role of HDM allergens is crucial in the development of allergic rhinitis and asthma, but the translation of silent sensitization into symptomatic disease is still incompletely understood. Improved understanding of HDMs, their allergens, and their microhabitats will enable development of more effective outcomes for patients with HDM allergy.

  14. Requirements for acquiring a high-quality house dust mite extract for allergen immunotherapy

    PubMed Central

    Frati, Franco; Incorvaia, Cristoforo; David, Marie; Scurati, Silvia; Seta, Simona; Padua, Guglielmo; Cattaneo, Eleonora; Cavaliere, Carlo; Di Rienzo, Alessia; Dell’Albani, Ilaria; Puccinelli, Paola

    2012-01-01

    The house dust mite is a major cause of respiratory allergy worldwide. The management of mite allergy is based on avoidance measures, drug treatment, and allergen immunotherapy, but only allergen immunotherapy is able to modify the natural history of the disease. Injectable subcutaneous immunotherapy was introduced a century ago, while sublingual immunotherapy was proposed in the 1980s and emerged in the ensuing years as an effective and safe option to subcutaneous immunotherapy. However, the quality of the extracts to be used in allergen immunotherapy is crucial for the success of treatment. The mite extract for sublingual immunotherapy known as Staloral 300 was developed to offer optimal characteristics concerning the mite culture medium, standardization, and allergen dose. Double-blind, placebo-controlled trials with Staloral 300 have provided a substantial part of the clinical evidence analyzed in a meta-analysis of the efficacy of allergen immunotherapy in mite-induced rhinitis and asthma. Safety and tolerability are very good, mild local reactions in the mouth being the most common side effect. This makes it feasible to carry out sublingual immunotherapy for the 3–5-year duration needed to achieve long-lasting tolerance to the specific allergen. The performance of Staloral 300 may provide optimal conditions for an effective and safe sublingual immunotherapy in patients with mite-induced respiratory allergy. PMID:22654506

  15. Requirements for acquiring a high-quality house dust mite extract for allergen immunotherapy.

    PubMed

    Frati, Franco; Incorvaia, Cristoforo; David, Marie; Scurati, Silvia; Seta, Simona; Padua, Guglielmo; Cattaneo, Eleonora; Cavaliere, Carlo; Di Rienzo, Alessia; Dell'Albani, Ilaria; Puccinelli, Paola

    2012-01-01

    The house dust mite is a major cause of respiratory allergy worldwide. The management of mite allergy is based on avoidance measures, drug treatment, and allergen immunotherapy, but only allergen immunotherapy is able to modify the natural history of the disease. Injectable subcutaneous immunotherapy was introduced a century ago, while sublingual immunotherapy was proposed in the 1980s and emerged in the ensuing years as an effective and safe option to subcutaneous immunotherapy. However, the quality of the extracts to be used in allergen immunotherapy is crucial for the success of treatment. The mite extract for sublingual immunotherapy known as Staloral 300 was developed to offer optimal characteristics concerning the mite culture medium, standardization, and allergen dose. Double-blind, placebo-controlled trials with Staloral 300 have provided a substantial part of the clinical evidence analyzed in a meta-analysis of the efficacy of allergen immunotherapy in mite-induced rhinitis and asthma. Safety and tolerability are very good, mild local reactions in the mouth being the most common side effect. This makes it feasible to carry out sublingual immunotherapy for the 3-5-year duration needed to achieve long-lasting tolerance to the specific allergen. The performance of Staloral 300 may provide optimal conditions for an effective and safe sublingual immunotherapy in patients with mite-induced respiratory allergy.

  16. Acarosan and the Acarex test in the control of house dust mite allergens in the home.

    PubMed

    Ridout, S; Twiselton, R; Matthews, S; Stevens, M; Matthews, L; Arshad, S H; Hide, D W

    1993-01-01

    House dust mites are believed to be major triggers for allergic disease in atopic individuals. As part of a programme controlling dietary and aero-allergen exposure in high-risk infants, an acaricidal foam and powder (Acarosan) was applied to bedroom and main living room carpets, as well as upholstered furniture, on four occasions in the first year of life. Dust was assayed for mite antigen (Der p1) and these results compared with the semi-quantitative assay of guanine content (Acarex Test). After nine months mean Der p1 levels had decreased by 70% in the treatment group. Proportionally, the greatest fall occurred in those items that had the highest initial mite antigen content. The Acarex score does show a correlation with Der p1 levels, but cannot replace antigen assay when accurate data is required. A chemical acaricide may help reduce house dust mite antigen levels, but is not by itself sufficient to reduce levels below that considered critical for sensitisation.

  17. Skin-associated Bacillus, staphylococcal and micrococcal species from the house dust mite, Dermatophagoides pteronyssinus and bacteriolytic enzymes.

    PubMed

    Tang, Vivian H; Chang, Barbara J; Srinivasan, Ambuja; Mathaba, Leslie T; Harnett, Gerald B; Stewart, Geoffrey A

    2013-12-01

    Dust mites produce bacteriolytic enzymes, one of which belongs to the NlpC/P60 superfamily comprising bacterial and fungal proteins. Whether this enzyme is derived from the mite or from mite-associated microbes is unclear. To this end, the bacteriology of mites per se, and carpet and mattress dust from a group of asthmatic children and their parents was investigated. Dust from parents' and children's mattresses yielded significantly more colony forming units compared with dust from their corresponding carpets. Zymography demonstrated some dusts contained bacteriolytic enzymes, and in nine of the twelve dust samples from three of five houses examined, a prominent bacteriolytic band was obtained that corresponded to the mite band, although in one home, other lytic bands were detected. Fifty bacterial isolates were obtained from surface-sterilised, commercially obtained Dermatophagoides pteronyssinus. 16S rRNA, tuf and rpoB gene sequencing of nine Gram-positive isolates identified them as Bacillus cereus, B. licheniformis, Staphylococcus aureus, S. epidermidis, S. capitis and Micrococcus luteus, known human skin commensals. 16S rRNA sequence homologies of four of the nine isolates identified as B. licheniformis formed a distinct phylogenetic cluster. All species secreted lytic enzymes during culture although the lytic profiles obtained differed between the rods and the cocci, and none of the bands detected corresponded to those observed in dust or mites. In conclusion, mites harbour a variety of bacterial species often associated with human skin and house dusts contain bacteriolytic enzymes that may be mite-derived. The identification of a novel cluster of B. licheniformis isolates suggests an ecological adaptation to laboratory-reared D. pteronyssinus. It remains to be determined whether the previously described mite-associated 14 K lytic enzyme is derived from a microbial source.

  18. Is permanent parasitism reversible?--critical evidence from early evolution of house dust mites.

    PubMed

    Klimov, Pavel B; OConnor, Barry

    2013-05-01

    Long-term specialization may limit the ability of a species to respond to new environmental conditions and lead to a higher likelihood of extinction. For permanent parasites and other symbionts, the most intriguing question is whether these organisms can return to a free-living lifestyle and, thus, escape an evolutionary "dead end." This question is directly related to Dollo's law, which stipulates that a complex trait (such as being free living vs. parasitic) cannot re-evolve again in the same form. Here, we present conclusive evidence that house dust mites, a group of medically important free-living organisms, evolved from permanent parasites of warm-blooded vertebrates. A robust, multigene topology (315 taxa, 8942 nt), ancestral character state reconstruction, and a test for irreversible evolution (Dollo's law) demonstrate that house dust mites have abandoned a parasitic lifestyle, secondarily becoming free living, and then speciated in several habitats. Hence, as exemplified by this model system, highly specialized permanent parasites may drastically de-specialize to the extent of becoming free living and, thus escape from dead-end evolution. Our phylogenetic and historical ecological framework explains the limited cross-reactivity between allergens from the house dust mites and "storage" mites and the ability of the dust mites to inhibit host immune responses. It also provides insights into how ancestral features related to parasitism (frequent ancestral shifts to unrelated hosts, tolerance to lower humidity, and pre-existing enzymes targeting skin and keratinous materials) played a major role in reversal to the free-living state. We propose that parasitic ancestors of pyroglyphids shifted to nests of vertebrates. Later the nest-inhabiting pyroglyphids expanded into human dwellings to become a major source of allergens.

  19. Studies on the Occurrence, Identification and Control of House Dust Mites at Rural Houses of Shebin El-Kom Locality, Egypt.

    PubMed

    Heikal, H M

    2015-04-01

    The present study was conducted at Elkom Elakhdar village, Shebin El-Kom, Menoufia Governorate along 2012 year seasons, to calculate and identify the species composition and the occurrence frequency of the extracted dust mites collected from three building ages at rural houses, as well as to determine the toxicity limits of different concentrations of three plant essential oils against two species of the family Pyroglyphidae the main causal of allergy to humans. The obtained results revealed that there were eleven mite species belong to five families (Pyroglyphidae, Chortoglyphidae, Glycyphagidae, Acaridae and Cheyletidae). Of the total collected mites (5276) the highest dominant percentage species was the dust mites: Dermatophagoides farinae (66.1%), followed by D. pteronyssinus (23.3%), while the percentages of the rest species: Chortoglyphus arcuatus, Lepidoglyphus destructor, Glycyphagus domesticus, Gohieria fusca, Tyrophagusputrescentiae, Caloglyphus sp, Cheyletus malaccensis, Blomia sp. and Acarus siro were ranged between 0.16-2.0%. Regarding to the effect of temperature degrees on mite population, high degrees more than 25 degrees C at summer season, decreased the numbers of D. farinae and D. pteronyssinus. Toxicological tests of the three plant essential oils against adult stages of D. farinae and D. pteronyssinus showed that lemon grass oil gave the highest toxicity effect, in comparison with geranium and thyme oils, where mortality percentages were approximately around 100% at 800 ppm concentration on both species. The LC50 of lemon grass were 228.992 and 293.615 ppm against the two species, respectively. From the results of the research, it could be recommend that it is preferable to apply control operation during summer season where the mite population density is the least, moreover, the botanical oil extracts effectively controlled the parasitic dust mites, D. farinae and D. pteronyssinus and can be used in the biological control programs, as well as

  20. The distribution of dust mite allergen in the houses of patients with asthma

    SciTech Connect

    Tovey, E.R.; Chapman, M.D.; Wells, C.W.; Platts-Mills, T.A.

    1981-11-01

    Using an inhibition radioimmunoassay for the major allergen from Dermatophagoides pteronyssinus (antigen P1), we studied the distribution of this dust allergen in the houses of patients with asthma. Both bed and floor dust samples contained a wide range of antigen P1, 100 to 100,000 ng/g of fine dust, and this concentration correlated well with the number of mite bodies (r . 0.81, p less than 0.001). We were unable to detect antigen P1 in the air of undisturbed rooms. However, during domestic activity, between 1 and 30 ng were collected on a filter than sampled air for 45 min at 17 L/min. Using a cascade impactor it was shown that greater than 80% of the airborne antigen P1 was associated with particles greater than 10 mu in diameter. Some of the particles containing allergen could be identified because they formed precipitin rings when impacted onto agarose containing rabbit antimite antiserum. These particles had the physical appearance of mite feces, which are the major source of antigen P1 in mite cultures. The results suggested that natural exposure to this dust allergen allows occasional fecal particles to enter the lungs and that these particles contain very concentrated allergen.

  1. Establishing health standards for indoor foreign proteins related to asthma: Dust mite, cat and cockroach

    SciTech Connect

    Platts-Mills, T.A.E.; Chapman, M.D.; Pollart, S.M.; Heymann, P.W.; Luczynska, C.M. )

    1990-01-01

    There is no doubt that a large number of individuals become allergic to foreign proteins that are predominantly or exclusively present indoors. In each case this immune response can be demonstrated either by immediate skin test responses or by measuring serum IgE antibodies. It has also been obvious for some time that patients presenting with asthma, perennial rhinitis and atopic dermatitis have an increased prevalence of IgE antibodies to these indoor allergens. More recently several epidemiological surveys have suggested that both mite exposure and IgE antibodies are important risk factors for asthma. The present situation is that assays have been developed capable of measuring the presence of mite, cockroach and cat allergens in house dust. Further clinical studies will be necessary to test the proposed standards for mite allergens and to define risk levels for other allergens.

  2. [House dust mite-crustaceans-molluscs syndrome. A rare variant of food allergy in primary sensitization to inhaled allergens].

    PubMed

    Kütting, B; Brehler, R

    2001-08-01

    80% of all cases in food allergy in adults are preceded by a clinical or subclinical sensitisation to inhalative allergens. Food allergy is caused by cross-reactions between ingested food and inhaled particles. We report a patient suffering from the house-dust mite-crustaceans-molluscs-syndrome. Here, house-dust mite is the sensitising agent, therefore even first ingestion of invertebrates such as snails, shrimps, mussels or oysters can lead to severe anaphylaxis.

  3. House Dust Mite Allergy in Korea: The Most Important Inhalant Allergen in Current and Future

    PubMed Central

    Jeong, Kyoung Yong; Park, Jung-Won

    2012-01-01

    The house-dust mite (HDM), commonly found in human dwellings, is an important source of inhalant and contact allergens. In this report, the importance of HDM allergy in Korea and the characteristics of allergens from dust mite are reviewed with an emphasis on investigations performed in Korea. In Korea, Dermatophagoides farinae is the dominant species of HDM, followed by D. pteronyssinus. Tyrophagus putrescentiae is also found in Korea, but its role in respiratory allergic disease in Korea is controversial. The relatively low densities of mite populations and concentrations of mite major allergens in dust samples from Korean homes, compared to westernized countries, are thought to reflect not only different climatic conditions, but also cultural differences, such as the use of 'ondol' under-floor heating systems in Korean houses. HDM are found in more than 90% of Korean houses, and the level of exposure to HDM is clinically significant. About 40%-60% of Korean patients suffering from respiratory allergies, and more than 40% of patients suffering from atopic dermatitis, are sensitized to HDM. Mite allergens can be summarized according to their inherent auto-adjuvant activities and/or their binding affinities to the adjuvant-like substances: proteolytic enzymes, lipid binding proteins, chitin binding proteins, and allergens not associated with adjuvant-like activity. In general, allergens with a strong adjuvant-like activity or adjuvant-binding activity elicit potent IgE reactivity. In Korea, Der f 2 is the most potent allergen, followed by Der f 1. Immune responses are modulated by the properties of the allergen itself and by the adjuvant-like substances that are concomitantly administered with the antigens. Characterization of allergenic molecules and elucidation of mechanisms by which adjuvant-like molecules modulate allergic reactions, not only in Korea but also worldwide, will provide valuable information on allergic diseases, and are necessary for the

  4. A study on the prevalence of house dust mites in Al-Arish city, North Sinai Governorate, Egypt.

    PubMed

    El-Sherbiny, Gihad T; El-Sherbini, Eman T; Saled, Nagla Mostafa K; Haridy, Fouad M; Morsy, Ayman T A

    2010-04-01

    Free living mites comprise a huge and various groups of tiny arthropods in the class Arachida, mainly of the Pyroglyphidae family. Exposure to allergens derived from house dust mite (HDM) feces is a postulated risk factor for allergic sensitization, asthma development and asthma morbidity. However, practical and effective method to mitigate these allergens in low-income, urban home environments remains elusive. It well known that (HDM) physiology is greatly affected by hydrothermal microclimatic condition. El Arish has subtropical climate and warm humid summer, such situation are favourable to proliferate house dust mites. As no valid data are available for house dust mites fauna of El Arish, this study was carried out to determine the prevalence and contamination rates of homes in El Arish city. Samples of house dust collected in 2008 from 50 houses in El Arish city were subjected to acarological examination. Acri were found in (34.6 %) of the samples collected from these homes. Results indicated that dust mites were present in all humid environments. Also, hypersensitivity to dust mites was common among patients with asthma.

  5. A study on the prevalence of house dust mites in Al-Arish city, North Sinai Governorate, Egypt.

    PubMed

    El-Sherbiny, Gihad T; El-Sherbini, Eman T; Saled, Nagla Mostafa K; Haridy, Fouad M; Morsy, Ayman T A

    2010-04-01

    Free living mites comprise a huge and various groups of tiny arthropods in the class Arachida, mainly of the Pyroglyphidae family. Exposure to allergens derived from house dust mite (HDM) feces is a postulated risk factor for allergic sensitization, asthma development and asthma morbidity. However, practical and effective method to mitigate these allergens in low-income, urban home environments remains elusive. It well known that (HDM) physiology is greatly affected by hydrothermal microclimatic condition. El Arish has subtropical climate and warm humid summer, such situation are favourable to proliferate house dust mites. As no valid data are available for house dust mites fauna of El Arish, this study was carried out to determine the prevalence and contamination rates of homes in El Arish city. Samples of house dust collected in 2008 from 50 houses in El Arish city were subjected to acarological examination. Acri were found in (34.6 %) of the samples collected from these homes. Results indicated that dust mites were present in all humid environments. Also, hypersensitivity to dust mites was common among patients with asthma. PMID:20503586

  6. House-dust Mite Asthma. Results of Challenge Tests on Five Criteria with Dermatophagoides pteronyssinus

    PubMed Central

    McAllen, Monica K.; Assem, E. S. K.; Maunsell, K.

    1970-01-01

    Twenty-eight patients with asthma and house-dust allergy were investigated by five different challenge tests with mite extract (Dermatophagoides pteronyssinus). These tests were performed on the skin, bronchi, nasal mucosa, and leucocytes, and on normal human lung tissue passively sensitized by the patients' serum. The results were compared with each other and with the clinical state of the patients. Of 21 patients on whom all five tests were carried out, positive reactions to every test were found in 14 (67%). Asthmatic attacks were readily induced by inhalation of the mite extract and occurred in 18 (86%). Nasal reactions were provoked in 18 (86%) and were not followed by asthmatic symptoms. A leucocyte test was positive in 19 (90%) and the serum test was positive in all (100%). Delayed asthmatic responses to bronchial challenge were seen in six patients, but there was no evidence that these were mediated by precipitins. Quantitatively there was no fixed pattern between the degrees of sensitivity of the different tissues in the same patient. The amount of mite antigen capable of causing an asthmatic reaction was extremely small—less than 1 μg. of mite material in several patients. In view of the prevalence of D. pteronyssinus in this country and its high allergenic potency, it is considered that this mite is an important factor in allergic asthma. PMID:4987898

  7. Allergic and nonallergic interactions between house dust mite allergens and airway mucosa.

    PubMed

    Roche, N; Chinet, T C; Huchon, G J

    1997-03-01

    Asthma and allergy are extremely frequent diseases, affecting 5-10% and 30% of the population, respectively. The prevalence of asthma has increased in many developed countries, which may be due to several factors, including increased exposure to house dust mite (HDM) allergens. HDM to which humans are most frequently sensitized are Dermatophagoides pteronyssinus, Dermatophagoides farinae, and Euroglyphus maynei. These mites multiply in carpets, bedding and upholstered furniture in a hot and humid atmosphere. The allergens are digestive enzymes of the mites. Several epidemiological studies have shown that an increase in exposure to HDMs is associated with an increase in the prevalence of sensitization and asthma, whereas mite avoidance leads to a decrease in respiratory symptoms of sensitized asthmatic subjects. Sensitized subjects have specific immunoglobulin G and E (IgG and IgE) humoral responses, as well as proliferative T-cell responses to HDM allergens. Experimental exposure to HDM allergens induces bronchoalveolar inflammatory responses, that are characterized by the recruitment and activation of eosinophils, mastocytes, neutrophils, monocytes and lymphocytes. The cysteine protease activity of Der p 1 (a major allergen of D. pteronyssinus) has been shown to increase airway mucosal permeability, and may thereby contribute to the pathogenesis of airway inflammation and hyperresponsiveness by nonimmunological mechanisms. These epidemiological and experimental data support the recommendations for mite avoidance, especially in persons at high risk of developing asthma.

  8. [Nursery schools, a site for exposure to house dust mite allergens?].

    PubMed

    Rebmann, H; Weller, A

    1989-10-01

    In June 1988, 110 dust samples from carpets, cushions, mattresses and upholstered furniture were collected by vacuum cleaner in 33 municipal nursery schools. All samples were assessed with guanine test strips (Acarex). In all samples giving moderately or strongly positive results in these tests (guanine stages 2 and 3) and in 10 random samples each from of stages 1 (weakly positive) and 0 (negative), mites were counted by light microscope. In 36% of the nursery schools, objects with guanine stages 2 or 3 were found, which indicates a high allergen burden. The high guanine stages were found only in mattresses, cushions and upholstered furniture. Nursery schools can be source areas of significant allergen exposure relevant for children with dust mite allergies.

  9. Effect on quality of life of the mixed house dust mite/weed pollen extract immunotherapy

    PubMed Central

    Li, Lisha

    2016-01-01

    Background Although many patients with allergic rhinitis have symptoms due to sensitization to more than one kind of allergens, and mixed allergen extracts are widely used for immunotherapy, there are few published trials. Objective Our study aimed to evaluate the effect of multiple-allergen immunotherapy on improving the symptoms and quality of life of allergic rhinitis patients. Methods We performed a 1-year single-center observation study of subcutaneous immunotherapy using house dust mite extract (n = 12), weed pollen extract (n = 21), or mixed house dust mite/weed pollen extract (n = 11) in 44 allergic rhinitis patients. All the allergens responsible for the symptom of each patient were included in his immunotherapy. Symptom score, medication score, and quality of life of the patients were evaluated before and after 1-year immunotherapy. Quality of life was evaluated with the Rhinoconjunctivitis Quality of Life Questionnaire. Results In all 3 groups receiving subcutaneous immunotherapy, significant improvement of symptom score, medication score, and quality of life was found vs. baseline at 1 year, irrespective of the allergen used. In the weed pollen season, the changes of quality of life questionnaire score after 1-year treatment were not significantly different between the weed pollen group (1.55 ± 1.24) and the mixed house dust mite/weed pollen group (1.14 ± 1.01). The same happened in the nonpollen seasons, during which dust mite immunotherapy (1.23 ± 1.63) and mixed immunotherapy (0.60 ± 0.47) did not show significantly different effect on the quality of life. Conclusion The multiple-allergen immunotherapy might be effective in polysensitized allergic rhinitis patients, and could improve their quality of life. Our result did not show significant difference between the effects of multiple-allergen immunotherapy and mono-allergen immunotherapy. PMID:27489789

  10. A novel nanostructured biosensor for the detection of the dust mite antigen Der p2

    PubMed Central

    Tsai, Jaw-Ji; Bau, I-Jiuan; Chen, He-Tsing; Lin, Yu-Ta; Wang, Gou-Jen

    2011-01-01

    The group 2 allergen, Der p2, has been reported to activate innate toll-like receptors (TLRs) on respiratory epithelial cells and thus aggravate respiratory diseases. In this study, a highly sensitive nanostructured biosensor based on a 3D sensing element with uniformly deposited gold nanoparticles is proposed for the detection of the dust mite antigen Der p2. The barrier layer comprises an anodic aluminum oxide (AAO) film which is used as the template in this highly sensitive nanostructured biosensor. Simple electrochemical deposition without reducing agent and stabilizer was enough to uniformly synthesize gold nanoparticles on the surface of the barrier layer. The size and the distribution density of the nanoparticles can be well controlled by the applied potential during electrochemical deposition. Following this procedure, the dust mite monoclonal antibodies (IgG) were then immobilized through the 11-MUA (11-mercaptoundecanoic acid), (1-ethyl-3-(3-dimethyl-aminopropyl)-carbodiimide)/(N-hydroxysuccinimide) self-assembled monolayer approach for the dust mite antigen Der p2 detection. The detection limit of the proposed 3D gold nanoparticle-based nanostructured biosensor was examined using electrochemical impedance spectroscopy analysis and found to be 1 pg/mL. The dynamic range was found to be 5 μg/mL. The proposed nanostructured biosensor would be useful for fast detection of rare molecules in a solution. PMID:21822382

  11. Crystallization and Preliminary X-ray Analysis of Der f 2, a Potent Allergen Derived from the House Dust Mite

    NASA Technical Reports Server (NTRS)

    Roeber, Dana; Achari, Aniruddha; Takai, Toshiro; Okumura, Yasushi; Scott, David L.; Curreri, Peter (Technical Monitor)

    2002-01-01

    Although a number of allergens have been identified and isolated, the underlying molecular basis for the potent immune response is poorly understood. House dust mites (Dermatophugoides sp.) are particularly ubiquitous contributors to atopy in developed countries. The rhinitis, dermatitis, and asthma associated with allergic reactions to these arthropods are often caused by relatively small (125-129 amino acids) mite proteins of unclear biological function. Der f 2, a major allergen from the mite Dermatophagoides farinae, has been recombinantly expressed and characterized. The Der f 2 protein has been crystallized in our laboratory and a native data set collected at a synchrotron source. The crystals belong to the orthorhombic space group I422 with unit cell parameters of a = 95.2 Angstroms, b = 95.2 Angstroms, and c = 103.3 Angstroms. An essentially complete (97.2%) data set has been collected to 2.4 Angstroms. Attempts to solve the crystal structure of Der f 2 by molecular replacement using the available NMR coordinates for either Der f 2 or Der p 2 (the homologous protein from D. pterovssinus) failed to reveal a creditable solution.

  12. Sero-prevalence study of IgE responses to allergens from Malaysian house dust (HDM) and storage mites (SM).

    PubMed

    Chong, K T; Wong, S F; Mak, J W; Loh, L C; Ho, T M

    2015-09-01

    Allergens of Dermatophagoides and Blomia species are well-characterized but not for other species. This study was conducted to determine the prevalence of allergic sensitization to house dust (HDM) and storage mites (SM). One hundred adult subjects (aged ≥ 18) were recruited. The mite specific IgE of all allergic subjects were higher compared with healthy subjetcs despite being not statistically significant except for D. farinae and G. malaysiensis. The mean serum IgE levels against HDM and SM for allergic subjects were significantly higher compared with those in healthy subjects. They were mainly sensitized to Dermatophagoides farinae (35%) and Glycycometus malaysiensis (37%). Immunoblots revealed not all allergic subjects showed positive immuno-reactivity against the mites tested. Single or multiple bands were observed for different species. The subjects were commonly sensitized to Group 2 (9-12 kDa), 10 (38 kDa) and 18 (40-48 kDa) allergens. Twenty-one out of 60 allergic subjects were sensitized to either one or more species. The majority of them (71%) were sensitized to single species. The allergic subjects were mainly sensitized to D. pteronyssinus, followed by Tyrophagus putrecentiae and Aleuroglyphus ovatus. Seven were solely sensitized to HDM while 10 were solely sensitized to SM. Four subjects were sensitized to both. Pre-adsorption study revealed no cross-reactivity. There was difference between the prevalence and reactivity to allergens of HDM and SM in these subjects. Both ELISA and immunoblot did not correlate well but can complement each other in improving the detection of mite allergens to the species level.

  13. New house dust collection system and its use in a study of asthma in dust mite sensitive children in Raleigh, North Carolina

    SciTech Connect

    Lindstrom, A.B.; Beck, M.A.; Henry, M.M.; Barnes, D.M.; Henderson, F.W.

    1993-01-01

    A prototype dust collection system, the House Dust Vacuum One (HDVI), was designed for use in a study to investigate the relationship between house dust mite antigen levels and the presence of asthma in dust mite sensitive children. The HDVI was designed for the collection of dust samples from all potentially relevant domestic substrates, with the primary sampling objective being the retrieval at least 100 mg of sample material. During the winter of 1991-92, dust samples were collected from six different microenvironments in the homes of 49 dust mite sensitive children living in the Raleigh, NC metropolitan area. In addition to the standard antigen immunoassay, the performance of the HDVI was assessed by conducting side by side comparison tests using two alternative antigen collection systems. Microenvironmental antigen concentrations were found to be lognormally distributed within the test homes and within each microenvironment. With the relatively large quantity of sample material collected and the ease with which the HDVI was able to collect samples from a wide variety of substrates, the new unit was determined to be well suited for surface dust and dust mite antigen collection studies.

  14. Mite-control activities of active constituents isolated from Pelargonium graveolens against house dust mites.

    PubMed

    Jeon, Ju-Hyun; Kim, Hyung-Wook; Kim, Min-Gi; Lee, Hoi-Seon

    2008-10-01

    The mite-control activities of materials obtained from Pelargonium graveolens oil against Dermatophagoides farinae and D. pteronyssinus were examined using an impregnated fabric disk bioassay and were compared with those shown by commercial benzyl benzoate and N,N-diethylm- toluamide (DEET). Purification of the biologically active constituents from P. graveolens oil was done by silica gel chromatography and high performance liquid chromatography. The structures of the active components were analyzed by EI/MS, (1)H-NMR, (13)C-NMR, (1)H-(13)C COSYNMR, and DEPT-NMR spectra, and were identified as geraniol (C(10)H(18)O, MW 154.25, trans-3,7-dimethyl-2,6- octadien-1-ol) and beta-citronellol (C(10)H(20)O, MW 156.27, 3,7-dimethyl-6-octen-1-ol). Based on the LD50 values, the most toxic compound was geraniol (0.26 microg/cm(2)), followed by beta-citronellol (0.28 microg/cm(2)), benzyl benzoate (10.03 microg/ cm(2)), and DEET (37.12 microg/cm(2)) against D. farinae. In the case of D. pteronyssinus, geraniol (0.28 microg/cm(2)) was the most toxic, followed by beta-citronellol (0.29 microg/cm(2)), benzyl benzoate (9.58 microg/cm(2)), and DEET (18.23 microg/cm(2)). These results suggest that D. farinae and D. pteronyssinus may be controlled more effectively by the application of geraniol and beta-citronellol than benzyl benzoate and DEET. Furthermore, geraniol and beta-citronellol isolated from P. graveolens could be useful for managing populations of D. farinae and D. pteronyssinus.

  15. Molecular Determinants for Antibody Binding on Group 1 House Dust Mite Allergens

    SciTech Connect

    Chruszcz, Maksymilian; Pomés, Anna; Glesner, Jill; Vailes, Lisa D.; Osinski, Tomasz; Porebski, Przemyslaw J.; Majorek, Karolina A.; Heymann, Peter W.; Platts-Mills, Thomas A.E.; Minor, Wladek; Chapman, Martin D.

    2012-07-11

    House dust mites produce potent allergens, Der p 1 and Der f 1, that cause allergic sensitization and asthma. Der p 1 and Der f 1 are cysteine proteases that elicit IgE responses in 80% of mite-allergic subjects and have proinflammatory properties. Their antigenic structure is unknown. Here, we present crystal structures of natural Der p 1 and Der f 1 in complex with a monoclonal antibody, 4C1, which binds to a unique cross-reactive epitope on both allergens associated with IgE recognition. The 4C1 epitope is formed by almost identical amino acid sequences and contact residues. Mutations of the contact residues abrogate mAb 4C1 binding and reduce IgE antibody binding. These surface-exposed residues are molecular targets that can be exploited for development of recombinant allergen vaccines.

  16. Synergistic interaction between the fungus Beauveria bassiana and desiccant dusts applied against poultry red mites (Dermanyssus gallinae).

    PubMed

    Steenberg, Tove; Kilpinen, Ole

    2014-04-01

    The poultry red mite, Dermanyssus gallinae, is a major pest in egg production, feeding on laying hens. Widely used non-chemical control methods include desiccant dusts, although their persistence under field conditions is often short. Entomopathogenic fungi may also hold potential for mite control, but these fungi often take several days to kill mites. Laboratory experiments were carried out to study the efficacy of 3 types of desiccant dusts, the fungus Beauveria bassiana and combinations of the two control agents against D. gallinae. There was significant synergistic interaction between each of the desiccant dusts and the fungus, with observed levels of mite mortality significantly higher than those expected for an additive effect (up to 38 % higher). Synergistic interaction between desiccant dust and fungus was found also when different application methods were used for the fungus and at different levels of relative humidity. Although increased levels of mortality were reached due to the synergistic interaction, the speed of lethal action was not influenced by combining the two components. The persistence of the control agents applied separately or in combination did not change over a period of 4 weeks. Overall, combinations of desiccant dusts and fungus conidia seem to hold considerable promise for future non-chemical control of poultry red mites. PMID:24253584

  17. Synergistic interaction between the fungus Beauveria bassiana and desiccant dusts applied against poultry red mites (Dermanyssus gallinae).

    PubMed

    Steenberg, Tove; Kilpinen, Ole

    2014-04-01

    The poultry red mite, Dermanyssus gallinae, is a major pest in egg production, feeding on laying hens. Widely used non-chemical control methods include desiccant dusts, although their persistence under field conditions is often short. Entomopathogenic fungi may also hold potential for mite control, but these fungi often take several days to kill mites. Laboratory experiments were carried out to study the efficacy of 3 types of desiccant dusts, the fungus Beauveria bassiana and combinations of the two control agents against D. gallinae. There was significant synergistic interaction between each of the desiccant dusts and the fungus, with observed levels of mite mortality significantly higher than those expected for an additive effect (up to 38 % higher). Synergistic interaction between desiccant dust and fungus was found also when different application methods were used for the fungus and at different levels of relative humidity. Although increased levels of mortality were reached due to the synergistic interaction, the speed of lethal action was not influenced by combining the two components. The persistence of the control agents applied separately or in combination did not change over a period of 4 weeks. Overall, combinations of desiccant dusts and fungus conidia seem to hold considerable promise for future non-chemical control of poultry red mites.

  18. Systemic Reactions to Dust Mite Subcutaneous Immunotherapy: A 3-Year Follow-up Study

    PubMed Central

    Dong, Xiang; Huang, Nan; Li, Wenjing; Hu, Lintao; Wang, Xiaolong; Wang, Yin; Xiang, Ning; Liu, Guanghui

    2016-01-01

    Purpose The incidence of allergen specific immunotherapy-related systemic reactions (SRs) varies among different studies, and many factors are likely to contribute to SRs. This study aims to investigate the incidence, characteristics, and risk factors of SRs to standardize dust mite-specific subcutaneous immunotherapy (SCIT) in Central China. Methods All patients receiving standardized dust mites (100-100,000 SQ-U/mL; Alutard SQ, Hørsholn, Denmark) immunotherapy were followed up. Recorded data included demographics, diagnosis, patient status, pulmonary function testing results before and after each injection, allergen dosage, and details of SRs. Results From June 2011 to August 2014, a total of 208 patients received 4,369 injections; 27 (13.0%) patients experienced 48 (1.1%) systemic reactions. Most of the SRs were grade 2 reactions (n=30, 62.5%), followed by grade 1 (n=11, 22.9%), grade 3 (n=7, 14.6%), and no fatal reactions occurred. Forty-six SRs (95.8%) occurred within 30 minutes. Higher SR rates were associated with high concentration extracts (100,000 SQ-U/mL), injections with concomitant local reactions (LRs), children, asthma and high sensitivity (skin prick test 3+/4+ and/or sIgE≥17.5 kUA/L) (P<0.05). The estimated odds of SRs increased in children (OR=6.57; 95% CI: 1.88-22.97, P=0.003), asthmatic patients (OR=4.10; 95% CI: 1.72-9.80, P=0.002), and injections with LRs (OR=2.41; 95% CI: 1.33-4.36, P=0.004). Conclusions The incidence of SRs to dust mite SCIT was low, and multiple factors were associated with the increased incidence of SRs. Children, asthmatics and patients with concomitant LR may be prone to develop SRs. PMID:27334780

  19. Gene expression in the skin of dogs sensitized to the house dust mite Dermatophagoides farinae.

    PubMed

    Schamber, Paz; Schwab-Richards, Rachel; Bauersachs, Stefan; Mueller, Ralf S

    2014-10-01

    Atopic dermatitis is a multifactorial allergic skin disease in humans and dogs. Genetic predisposition, immunologic hyperreactivity, a defective skin barrier, and environmental factors play a role in its pathogenesis. The aim of this study was to analyze gene expression in the skin of dogs sensitized to house dust mite antigens. Skin biopsy samples were collected from six sensitized and six nonsensitized Beagle dogs before and 6 hr and 24 hr after challenge using skin patches with allergen or saline as a negative control. Transcriptome analysis was performed by the use of DNA microarrays and expression of selected genes was validated by quantitative real-time RT-PCR. Expression data were compared between groups (unpaired design). After 24 hr, 597 differentially expressed genes were detected, 361 with higher and 226 with lower mRNA concentrations in allergen-treated skin of sensitized dogs compared with their saline-treated skin and compared with the control specimens. Functional annotation clustering and pathway- and co-citation analysis showed that the genes with increased expression were involved in inflammation, wound healing, and immune response. In contrast, genes with decreased expression in sensitized dogs were associated with differentiation and barrier function of the skin. Because the sensitized dogs did not show differences in the untreated skin compared with controls, inflammation after allergen patch test probably led to a decrease in the expression of genes important for barrier formation. Our results further confirm the similar pathophysiology of human and canine atopic dermatitis and revealed genes previously not known to be involved in canine atopic dermatitis.

  20. Gene Expression in the Skin of Dogs Sensitized to the House Dust Mite Dermatophagoides farinae

    PubMed Central

    Schamber, Paz; Schwab-Richards, Rachel; Bauersachs, Stefan; Mueller, Ralf S.

    2014-01-01

    Atopic dermatitis is a multifactorial allergic skin disease in humans and dogs. Genetic predisposition, immunologic hyperreactivity, a defective skin barrier, and environmental factors play a role in its pathogenesis. The aim of this study was to analyze gene expression in the skin of dogs sensitized to house dust mite antigens. Skin biopsy samples were collected from six sensitized and six nonsensitized Beagle dogs before and 6 hr and 24 hr after challenge using skin patches with allergen or saline as a negative control. Transcriptome analysis was performed by the use of DNA microarrays and expression of selected genes was validated by quantitative real-time RT-PCR. Expression data were compared between groups (unpaired design). After 24 hr, 597 differentially expressed genes were detected, 361 with higher and 226 with lower mRNA concentrations in allergen-treated skin of sensitized dogs compared with their saline-treated skin and compared with the control specimens. Functional annotation clustering and pathway- and co-citation analysis showed that the genes with increased expression were involved in inflammation, wound healing, and immune response. In contrast, genes with decreased expression in sensitized dogs were associated with differentiation and barrier function of the skin. Because the sensitized dogs did not show differences in the untreated skin compared with controls, inflammation after allergen patch test probably led to a decrease in the expression of genes important for barrier formation. Our results further confirm the similar pathophysiology of human and canine atopic dermatitis and revealed genes previously not known to be involved in canine atopic dermatitis. PMID:25098772

  1. Der p 5 Crystal Structure Provides Insight into the Group 5 Dust Mite Allergens

    SciTech Connect

    Mueller, G.; Gosavi, R; Krahn, J; Edwards, L; Cuneo, M; Glesner, J; Pomes, A; Chapman, M; London, R; Pedersen, L

    2010-01-01

    Group 5 allergens from house dust mites elicit strong IgE antibody binding in mite-allergic patients. The structure of Der p 5 was determined by x-ray crystallography to better understand the IgE epitopes, to investigate the biologic function in mites, and to compare with the conflicting published Blo t 5 structures, designated 2JMH and 2JRK in the Protein Data Bank. Der p 5 is a three-helical bundle similar to Blo t 5, but the interactions of the helices are more similar to 2JMH than 2JRK. The crystallographic asymmetric unit contains three dimers of Der p 5 that are not exactly alike. Solution scattering techniques were used to assess the multimeric state of Der p 5 in vitro and showed that the predominant state was monomeric, similar to Blo t 5, but larger multimeric species are also present. In the crystal, the formation of the Der p 5 dimer creates a large hydrophobic cavity of {approx}3000 {angstrom}{sup 3} that could be a ligand-binding site. Many allergens are known to bind hydrophobic ligands, which are thought to stimulate the innate immune system and have adjuvant-like effects on IgE-mediated inflammatory responses.

  2. Reduction of house-dust mite allergen concentrations in carpets by aluminium potassium sulfate dodecahydrate (alum).

    PubMed

    Sevki, Coskun; Levent, Aydin; Ender, Gulegen; Firdevs, Mor

    2006-01-01

    Special tools and skilled labor are required to reduce house-dust mite allergens in carpets. The main house-dust mite allergen is Der p 1, a soluble protein found in high abundance in woolen carpets. Current chemical treatment options are either unsafe or ineffective in eradicating Der p 1. Here, we present an effective, safe, and easy application reagent to reduce the allergen levels in carpets. Sixty woolen carpets with Der p 1 concentrations >2 microg/g in fine dust were divided into three homogeneous groups of 20 carpets each, according to their allergen load. We tested alum dissolved in 60 mL of water at doses of 3, 6, and 9 g/m2 against Der p 1 in groups 1, 2, and 3, respectively. The test side of the carpets was sprayed with the reagent. The control side was treated with the 60 mL of tap water. Dust particles were collected from a 1-m2 area on each carpet side 24 hours after treatment and were analyzed for Der p 1 content with a monoclonal ELISA. Alum reduced the Der p 1 concentrations by 48.6 +/- 6.2%, 78.8 +/- 7.2%, and 95.2 +/- 3.0% at 3, 6, and 9 g/m2 in the carpets, respectively. Moreover, there were no complaints registered by the residents against the alum applications. Alum, at 9 g/m2 (in a solution at 15%) in water, can be used for decreasing existing Der p 1 concentrations in woolen carpets.

  3. Efficacy of an In-home Test Kit in Reducing Dust Mite Allergen Levels: Results of a Randomized Controlled Pilot Study

    PubMed Central

    Winn, Amber K.; Salo, Päivi M.; Klein, Cynthia; Sever, Michelle L.; Harris, Shawn F.; Johndrow, David; Crockett, Patrick W.; Cohn, Richard D.; Zeldin, Darryl C.

    2015-01-01

    Background Dust mite allergens can induce allergic sensitization and exacerbate asthma symptoms. Although dust mite reduction and control strategies exist, few asthmatics employ them. Objectives We examined whether an in-home test kit, which quantifies dust mite allergen levels, resulted in behavioral changes in implementation and maintenance of mite reduction strategies and helped reduce allergen levels in homes of dust mite-sensitive children. Methods We enrolled 60 households of children aged 5-15 with parent-reported dust mite allergy into a randomized controlled trial. Intervention homes (N=30) received educational material about reducing dust mites and test kits at 1,2,5, and 8 months. Control homes (N=30) received only educational material. At baseline, 6 and 12 months, study staff visited all homes, collected dust samples from 3 locations and obtained information about parents’ mite reduction behaviors by questionnaire. Allergen concentrations (Der f 2/Der p2) in dust were assessed by immunoassays. After adjusting for visit and location, allergen concentrations in intervention and control homes were compared using mixed effects model analysis. Results In the intervention homes, allergen concentrations in the child's bedroom and living room floors were significantly reduced over time compared to control homes. Although not all location-specific differences in allergen concentrations were statistically significant, combining data across locations, there was a differential reduction in allergen concentrations in the intervention group versus the control group (p =0.02). Conclusion The use of in-home test kits along with education may beneficially influence behaviors and attitudes towards dust mite reduction strategies and help reduce residential dust mite allergen levels. PMID:26308287

  4. Evaluation of new sensitizations in asthmatic children monosensitized to house dust mite by specific immunotherapy.

    PubMed

    Harmanci, Koray; Razi, Cem H; Toyran, Muge; Kanmaz, Gozde; Cengizlier, Mehmet R

    2010-03-01

    Specific immunotherapy (SIT) is one of the treatment modalities recomended for the management of asthma and allergic rhinitis by international guidelines. A potential benefit of immunotherapy (IT) is to prevent the development of sensitisation to new allergens. There is stil no conclusion on this subject. One hundred twenty-two children 8-18 years old with intermittent asthma, with or without allergic rhinitis, all of whom were monosensitised to house dust mite (HDM) were selected. Sixty two of these children accepted to receive SIT with HDM extract for 4 years and the remaining 60 did not accept SIT and were treated with asthma medications only. This second group of children served as the control group. At the end of the 4-year study period, 36 of the 53 patients (67.9%) in the SIT group showed no new sensitizations, compared to 38 of 52 (73.0%) in the control group (p = 0.141). The most frequent new sensitizations at the end of the study were pollens, grasses and olive polen, followed by animal dander, alternaria and cockroach. In conclusion, SIT may not prevent the onset of new sensitizations in asthmatic children monosensitized to house dust mites. Further investigation is required to clarify the immunologic mechanisms and other factors by which SIT reduces or not the development of new sensitizations in monosensitized children. PMID:20527510

  5. Endotoxin and House Dust Mite Allergen Levels on Synthetic and Buckwheat Pillows

    PubMed Central

    Nam, Hae-Seon; Park, Choon-Sik; Crane, Julian

    2004-01-01

    Pillows are known to contain significant levels of indoor allergens and endotoxin, that are of importance to house dust mite sensitized asthmatics. Buckwheat pillows are commonly used in Korea. We studied the levels of the house dust mite allergen, Der f 1, and endotoxin on new synthetic and buckwheat pillows and their accumulation over three months. Endotoxin levels were significantly higher on new buckwheat pillows compared to synthetic pillows; geometric mean levels (95% CI) were 60,950 EU/g (30,270-122,700) and 4,887 EU/g (2,570-9,311) respectively (p<0.001). No Der f 1 was detected on the new pillows. After three months Der f 1 levels were similar on buckwheat and synthetic pillows, geometric mean levels (95% CI) were 1.16 µg/g (0.02-8.13) and 1.08 µg/g (0.19-1.68) respectively. These results indicate that buckwheat pillows are a source of very high endotoxin levels that may be of relevance to asthma severity of atopic asthmatics. PMID:15308838

  6. [Acarex test and acarosan effect in house dust mite allergy in 2 year follow-up].

    PubMed

    Kersten, W; Stollewerk, D; von Wahl, P G

    1992-01-01

    Clinical investigations of the effect of the acaricide product Acarosan shows in a large collective of patients beneficial results, whereby the patients are examined up to three months after sanitation. The remaining patients of this study are followed up one and two years after sanitation in open clinical trials. Without exception Acarex test values decrease highly significant after three months, indicating the effective elimination of the house dust mites by Acarosan treatment and consequently the reduction of the allergen containing excreta. The values increase after one year, but after a repetition of the Acarosan treatment they decrease again to the level reached after the first sanitation. The best results are achieved by sanitation of carpets, less favourable results are obtained by treating matresses and upholstered furniture. After sanitation all patients with monovalent house dust mite sensitization report an improvement of their symptoms (eyes, nose, bronchi) up to two years. Drug consumption is variable and decreases over all for up to two years. Peak flow meter values improve in the first year and even further more in the second year. The clinical improvement does not depend on sex, living area or former immunotherapy. During the two year observation period immunologic parameters do not change. 25.6% of the patients show a negative provocation test after the first year and 57% after the second year. Side effects due to the sanitation or signs of sensitization against Acarosan are not observed.

  7. Biological activity of recombinant Der p 2, Der p 5 and Der p 7 allergens of the house-dust mite Dermatophagoides pteronyssinus.

    PubMed

    Lynch, N R; Thomas, W R; Garcia, N M; Di Prisco, M C; Puccio, F A; L'opez, R I; Hazell, L A; Shen, H D; Lin, K L; Chua, K Y

    1997-09-01

    Der p 2, Der p 5 and Der p 7 are three allergens of the house-dust mite Dermatophagoides pteronyssinus that have been cloned and expressed in Escherichia coli as fusion proteins with glutathione-S-transferase (GST). We showed that these recombinant allergens produced immediate hypersensitivity skin-test reactions in 70, 60 and 52% respectively of a group of mite-sensitive allergic patients who were strongly positive to whole mite extract (WME). Comparable positivities were found for serum levels of specific IgE antibody against these allergens, as measured by the radioallergosorbant test (RAST). Overall, for the group of allergic patients that we evaluated, the serum IgE antibody concentrations against Der p 2, 5 and 7 were calculated to represent about one third, one quarter and one fifth respectively of the levels measured against the WME. However, for some patients the activity determined against the separate allergens was far higher than that detected against the WME, thus indicating that the concentration of these can be limiting in the WME. We found no significant correlations between the RAST levels against Derp 2 and either Derp 5 or 7, and RAST-inhibition tests indicated a lack of cross-reactivity between Der p 2 and the other two allergens. In contrast, the RAST results revealed the existence of a significant immunological relationship between Der p 5 and 7. Although a certain degree of reactivity against the GST fusion partner was found in the allergic patients studied, this was not a significant influence in determining the positivity against the recombinant allergens. These results confirm the in vivo biological activity of recombinant Der p 2, 5 and 7, and indicate that whilst Der p 2 is undoubtedly a major mite allergen, both Der p 5 and 7 make important contributions toward the overall allergenic activity of house-dust mites. PMID:9303332

  8. Acaricidal activities of some essential oils and their monoterpenoidal constituents against house dust mite, Dermatophagoides pteronyssinus (Acari: Pyroglyphidae)

    PubMed Central

    Saad, El-Zemity; Hussien, Rezk; Saher, Farok; Ahmed, Zaitoon

    2006-01-01

    The acaricidal activities of fourteen essential oils and fourteen of their major monoterpenoids were tested against house dust mites Dermatophagoides pteronyssinus. Five concentrations were used over two different time intervals 24 and 48 h under laboratory conditions. In general, it was noticed that the acaricidal effect based on LC 50 of either essential oils or monoterpenoids against the mite was time dependant. The LC 50 values were decreased by increasing of exposure time. Clove, matrecary, chenopodium, rosemary, eucalyptus and caraway oils were shown to have high activity. As for the monoterpenoids, cinnamaldehyde and chlorothymol were found to be the most effective followed by citronellol. This study suggests the use of the essential oils and their major constituents as ecofriendly biodegradable agents for the control of house dust mite, D. pteronyssinus. PMID:17111463

  9. Comparison of the Allergic Responses Induced by PeniciIlium chrysogenum and House Dust Mite Extracts in a Mouse Model

    EPA Science Inventory

    A report by the Institute of Medicine suggested that more research is needed to better understand mold effects on allergic disease, particularly asthma development. We compared the ability of the fungal Penicillium chrysogenum (PCE) and house dust mite (HDM) extracts to induce al...

  10. Allergy to house dust mites in primary health care subjects with chronic or recurrent inflammatory states of respiratory system.

    PubMed

    Paszkowski, Jacek; Łopatyński, Jerzy

    2002-01-01

    Chronic and recurrent respiratory tract disorders are a frequent problem in general practice. The purpose of the study was to investigate the role of hypersensitivity to house dust mites in respiratory tract diseases in general practice patients. We tried to assess the influence of determined risk factors exposure on development of respiratory tract allergy. Patients from family practitioners surgeries with chronic or recurrent respiratory tract symptoms who had no diagnosis of allergy were recruited to the study (n = 89). All patients responded to a questionnaire focused on history of symptoms, atopic conditions in family and exposure to determined environmental factors like dwelling conditions, obstetrician history, diet in the first year of life. All patients underwent skin prick test with common inhalant allergens. Families of the patients were asked to participate in the study. Families who agreed to take part also responded to the questionnaire and underwent skin tests. In patients and their families blood samples were taken to determine total IgE and specific IgE antibodies to mites allergens. Dust samples were collected by vacuuming of patients' bedroom carpets and mattresses to determine house dust mites allergens concentration. Data on 30 complete patients family sets of their brotherhood, mother and father were collected. Total and specific serum IgE antibodies were determined by disc enzyme-immunoassay (Analco). Mites allergens concentration in dust was measured by simple Acarex strip test (Nexter). The results of the assays (positive skin tests and/or elevated levels of specific IgE) showed allergy to house dust mites in 24 of 89 study patients from general practitioners surgeries (27%). The prevalence of chronic rhinitis, recurrent bronchitis, chronic or recurrent cough, wheezing, dyspnoea was higher in allergic than in nonallergic subjects. Patients with the diagnosis of allergy to house dust mites had usually worse dwelling conditions. Especially

  11. House dust and storage mite contamination of dry dog food stored in open bags and sealed boxes in 10 domestic households.

    PubMed

    Gill, Christina; McEwan, Neil; McGarry, John; Nuttall, Tim

    2011-04-01

    Dry pet food is a potential source of exposure to house dust and storage mite allergens in canine atopic dermatitis. This study evaluated contamination of house dust and dry dog food stored in paper bags, sealable plastic bags and sealable plastic boxes in 10 households for 90 days using Acarex(®) tests for guanine, a Der p 1 ELISA and mite flotation. Acarex(®) tests were negative in all the food samples but positive in all the house dust samples. The Der p 1 levels and mite numbers significantly increased in food from paper bags (P = 0.0073 and P = 0.02, respectively), but not plastic bags or boxes. Mite numbers and Der p 1 levels were 10-1000 times higher in house dust than the corresponding food samples (P < 0.0001). There were significant correlations between Der p 1 in house dust and food from the paper (P < 0.0001) and plastic bags (P = 0.003), and mite numbers in house dust and food from the paper bags (P = 0.0007). Bedding and carpets were significantly associated with Der p 1 levels in house dust (P = 0.015 and P = 0.01, respectively), and food from the paper (both P = 0.02) and plastic bags (P = 0.03 and P = 0.04, respectively). Mites were identified in six of 10 paper bag, three of 10 plastic bag, one of 10 plastic box and nine of 10 house dust samples. These comprised Dermatophagoides (54%), Tyrophagus (10%; all from food) and unidentified mites (36%). Storage of food in sealable plastic boxes largely prevented contamination for 3 months. Exposure to mites and mite proteins in all the stored food, however, appeared to be trivial compared with house dust.

  12. [Hyposensitization with extracts of house dust and mites adsorbed on aluminium-hydroxyde (allpyral) in children with bronchial asthma (author's transl)].

    PubMed

    Osváth, P; Endre, L

    1976-03-01

    Since the year 1971 the authors have treated 39 asthmatic patients with Allpyral house dust vaccins containing Dermatophagoides farinae extract. 16 of these children previously had similar treatment, but without mite extract, and this was changed because of the poor results. Patients allergic only to house dust and mites were selected according to the skin tests. Skin reaction to mite extract did not change even in symptomfree children in contrast to the decrease or disappearance of skin sensitivity to house dust. 23 out of 39 patients had no symptoms or only mild and short wheezing occasionaly in the last 3-6 months of treatment. There were six patients whose symptoms remained unchanged during the treatment. These children were all among the 16 asthmatics who previously had an unsuccessful house dust hyposensitization. So every patient whose treatment was started with the combined house dust-mite Allpyral has imporved, only 5 of the 23 still had yet a few asthmatic attacks.

  13. Selective allergy to lobster in a case of primary sensitization to house dust mites.

    PubMed

    Iparraguirre, A; Rodríguez-Pérez, R; Juste, S; Ledesma, A; Moneo, I; Caballero, M L

    2009-01-01

    Allergy to only 1 kind of seafood is uncommon. We report a case of selective allergy to lobster. We studied a 30-year-old man who suffered generalized urticaria, facial erythema, and pharyngeal pruritus after eating lobster. He had a more than 10-year history of mild persistent asthma and sensitization to house dust mites. The study was performed by skin prick test, and prick-prick test, oral food challenge, specific immunoglobulin (Ig) E determinations by CAP (Phadia, Uppsala, Sweden) and ADVIA-Centaur (ALK-Abelló, Madrid, Spain), and IgE-immunoblotting. The patient's serum recognized 2 allergens of around 198 kDa and 2 allergens of around 65 kDa from the lobster extract, allergens of around 15, 90, and 120 kDa from Dermatophagoides pteronyssinus extract, and allergens of around 15 and 65 kDa from Dermatophagoides farinae extract. Serum did not recognize purified shrimp tropomyosin. Immunoblot-inhibition assay results indicated cross-reactivity between lobster and mite allergens. This is the first report of selective allergy to lobster.

  14. Prevention of House Dust Mite Induced Allergic Airways Disease in Mice through Immune Tolerance

    PubMed Central

    Agua-Doce, Ana; Graca, Luis

    2011-01-01

    Allergic airways disease is a consequence of a Th2 response to an allergen leading to a series of manifestations such as production of allergen-specific IgE, inflammatory infiltrates in the airways, and airway hyper-reactivity (AHR). Several strategies have been reported for tolerance induction to allergens leading to protection from allergic airways disease. We now show that CD4 blockade at the time of house dust mite sensitization induces antigen-specific tolerance in mice. Tolerance induction is robust enough to be effective in pre-sensitized animals, even in those where AHR was pre-established. Tolerant mice are protected from airways eosinophilia, Th2 lung infiltration, and AHR. Furthermore, anti-CD4 treated mice remain immune competent to mount immune responses, including Th2, to unrelated antigens. Our findings, therefore, describe a strategy for tolerance induction potentially applicable to other immunogenic proteins besides allergens. PMID:21818308

  15. Rare adverse events due to house dust mite sublingual immunotherapy in pediatric practice: two case reports.

    PubMed

    Galip, Nilufer; Bahceciler, Nerin

    2015-01-01

    Sublingual route, a noninjective way of allergen administration appears to be associated with a lower incidence of severe systemic reactions compared with the subcutaneous route. Local adverse reactions are reported which resolve spontaneously within a few days without need for discontinuation of treatment. Hereby, we report two pediatric cases, one with persistent asthma and the other one with persistent allergic rhinitis. Both were treated by house dust mite sublingual immunotherapy, one of whom developed severe wheezing (grade 2 systemic reaction based on World Allergy Organization subcutaneous systemic reaction grading system) and the other intractable vomiting (grade 3 local reaction based on World Allergy Organization sublingual immunotherapy local adverse events grading system) at the end of the build-up phase which repeated on re-administration of the same dose. Both of those two cases completed their 3-year immunotherapy successfully by patient-based adjustment of the highest tolerated dose of the maintenance.

  16. Distribution and abundance of house dust mites, Dermatophagoides spp., in different ecological localities in Esna City, Kena Governorate, Egypt.

    PubMed

    Yassin, M K; Rifaat, M M

    1997-08-01

    The distribution and abundance of house dust mites, Dermatophagoides spp. were studied in July, September and November, 1995 in three different localities in Esna City, Kena Governorate, Upper Egypt. During these months, 15 houses were sampled in each locality. 87% of riverside houses were infested with mites where D. pteronyssinus dominated (80%) over D. farinae. Sixty percent of the valley houses sampled were infested, where D. farinae was dominant (66%). Densities of both Dermatophagoides spp., were considerably higher in riverside than in valley houses. Live mites were not found in the lightly infested houses sampled in the desert area (54% positive). Relative humidity, which varied in houses located in different climatic localities in Esna City, was noted to be the principal limiting factor influencing the distribution and abundance of both species. Temperature did not appear to be an important factor influencing the distribution and abundance.

  17. Revealing the Hyperdiverse Mite Fauna of Subarctic Canada through DNA Barcoding

    PubMed Central

    Young, Monica R.; Behan-Pelletier, Valerie M.; Hebert, Paul D. N.

    2012-01-01

    Although mites are one of the most abundant and diverse groups of arthropods, they are rarely targeted for detailed biodiversity surveys due to taxonomic constraints. We address this gap through DNA barcoding, evaluating acarine diversity at Churchill, Manitoba, a site on the tundra-taiga transition. Barcode analysis of 6279 specimens revealed nearly 900 presumptive species of mites with high species turnover between substrates and between forested and non-forested sites. Accumulation curves have not reached an asymptote for any of the three mite orders investigated, and estimates suggest that more than 1200 species of Acari occur at this locality. The coupling of DNA barcode results with taxonomic assignments revealed that Trombidiformes compose 49% of the fauna, a larger fraction than expected based on prior studies. This investigation demonstrates the efficacy of DNA barcoding in facilitating biodiversity assessments of hyperdiverse taxa. PMID:23133656

  18. No Concentration Decrease of House Dust Mite Allergens With Rising Altitude in Alpine Regions

    PubMed Central

    Grafetstätter, Carina; Prossegger, Johanna; Braunschmid, Herbert; Sanovic, Renata; Hahne, Penelope; Pichler, Christina; Thalhamer, Josef

    2016-01-01

    Purpose Several studies over the past 4 decades have indicated a significant reduction in house dust mite (HDM) and HDM allergen concentration in areas higher than 1,500 m above sea level. These have served as basis of allergen avoidance therapies for HDM allergy and asthma. However, modern construction techniques used in the insulation, heating, and glazing of buildings as well as global warming have changed the environmental parameters for HDM living conditions. The present study revisits the paradigm of decreasing HDM allergen concentrations with increasing altitude in the alpine region of Germany and Austria. Methods A total of 122 dust samples from different abodes (hotels, privates and mountain huts) at different altitudes (400-2,600 m) were taken, and concentrations of HDM allergens were analyzed. Humidity and temperature conditions, and numerous indoor environmental parameters such as fine dust, type of flooring, age of building, and frequency of cleaning were determined. Results HDM allergen concentrations did not significantly change with increasing altitude or relative humidity. At the level of indoor parameters, correlations could be found for different flooring types and the concentration of HDM allergens. Conclusions In contrast to the widespread view of the relationship between altitude and HDM allergen concentrations, clinically relevant concentrations of HDM allergens could be detected in high-lying alpine regions in Austria and Germany. These results indicate that improvement in conditions of asthmatic patients sensitized against HDMs during a stay at high altitude can no longer be ascribed to decreased levels of HDM allergens, instead, other mechanisms may trigger the beneficial effect. PMID:27126724

  19. [Comparative studies of the effectiveness of specific immunotherapy in house dust mite allergy].

    PubMed

    Ebner, H; Neuchrist, C; Havelec, L; Kraft, D

    1989-08-01

    In a prospective study, 60 patients with allergic rhinoconjunctivitis and/or asthma due to house dust mites were chosen for hyposensitization treatment with Migen (M) or Pharmalgen (P). Immunotherapy stretched over a whole year and every 3 months clinical results were evaluated by the patient's symptom score, by results of skin prick and conjunctival provocation tests, as well as by RIA and ELISA regarding the total and specific IgE and also specific IgG and IgG4 levels. Out of 30 patients of the M group, 15 were followed up over the whole therapeutic regimen, 4 of whom showed a very good, 7 a good to moderate clinical outcome and 4 showed no improvement at all. In the P group, 17 out of 30 patients were followed up whereby 9 showed a very good and 8 a good to moderate response. In both groups of patients a statistically significant decrease in skin and conjunctival sensitivity to mite allergens was observed after 12 months of therapy. However, there was no correlation between this observation and the failure or success of immunotherapy. Furthermore, in both groups there was significant increase in total and specific IgE (with a slight decrease after 6 to 12 months) and also in specific IgG and IgG4 (especially in the P group), but again these changes in antibody levels gave no indication of a good or bad clinical outcome. Hence, we believe other reasons than the usually presented thesis of inducing "blocking antibodies" by immunotherapy to be responsible for the well-known effects of hyposensitization.

  20. Immunization of rabbits with nematode Ascaris lumbricoides antigens induces antibodies cross-reactive to house dust mite Dermatophagoides farinae antigens.

    PubMed

    Nakazawa, Takuya; Khan, Al Fazal; Yasueda, Hiroshi; Saito, Akemi; Fukutomi, Yuma; Takai, Toshiro; Zaman, Khalequz; Yunus, Md; Takeuchi, Haruko; Iwata, Tsutomu; Akiyama, Kazuo

    2013-01-01

    There are controversial reports on the relationship between helminthic infection and allergic diseases. Although IgE cross-reactivity between nematode Ascaris antigens and house dust-mite allergens in allergic patients have been reported, whether Ascaris or the mite is the primary sensitizer remains unknown. Here we found that immunization of naïve animals with Ascaris lumbricoides (Al) antigens induced production of antibodies cross-reactive to mite antigens from Dermatophagoides farinae (Df). Sera from Bangladeshi children showed IgE reactivity to Ascaris and mite extracts. IgG from rabbits immunized with Al extract exhibited reactivity to Df antigens. Treatment of the anti-Al antibody with Df antigen-coupled beads eliminated the reactivity to Df antigens. In immunoblot analysis, an approximately 100-kDa Df band was the most reactive to anti-Al IgG. The present study is the first step towards the establishment of animal models to study the relationship between Ascaris infection and mite-induced allergic diseases.

  1. The relative risks of sensitivity to grass pollen, house dust mite and cat dander in the development of childhood asthma.

    PubMed

    Sears, M R; Herbison, G P; Holdaway, M D; Hewitt, C J; Flannery, E M; Silva, P A

    1989-07-01

    The associations between skin sensitivity to various common allergens and the development of childhood asthma were ascertained in a longitudinal study of a birth cohort of New Zealand children up to the age of 13 years. Of 714 children skin-tested, 45.8% were sensitive to at least one of 11 allergens, the most common responses being to rye grass pollen (32.5%), house dust mite (30.1%) and cat dander (13.3%). Allergen-specific relative risk analysis, controlled for the effect of sensitivity to other allergens, demonstrated that sensitivity to house dust mite and to cat dander were highly significant independent risk factors associated with the development of asthma (whether defined as recurrent typical respiratory symptoms, increased airway responsiveness, or the concurrent presence of both), whereas grass sensitivity was not a significant independent risk factor for asthma.

  2. [Ecological data on house dust mites in the city of Semipalatinsk].

    PubMed

    Iagofarov, F F; Galikeev, Kh L

    1987-01-01

    Distribution of mites of the genus Dermatophagoides in flats of allergic patients depending on the type of the building structure, relative air humidity and season of the year was studied. The mites are most frequently encountered in houses of wood or adobe with high air humidity. Autumn is an optimum season for reproduction of mites.

  3. T Follicular Helper Cell Plasticity Shapes Pathogenic T Helper 2 Cell-Mediated Immunity to Inhaled House Dust Mite.

    PubMed

    Ballesteros-Tato, André; Randall, Troy D; Lund, Frances E; Spolski, Rosanne; Leonard, Warren J; León, Beatriz

    2016-02-16

    Exposure to environmental antigens, such as house dust mite (HDM), often leads to T helper 2 (Th2) cell-driven allergic responses. However, the mechanisms underlying the development of these responses are incompletely understood. We found that the initial exposure to HDM did not lead to Th2 cell development but instead promoted the formation of interleukin-4 (IL-4)-committed T follicular helper (Tfh) cells. Following challenge exposure to HDM, Tfh cells differentiated into IL-4 and IL-13 double-producing Th2 cells that accumulated in the lung and recruited eosinophils. B cells were required to expand IL-4-committed Tfh cells during the sensitization phase, but did not directly contribute to disease. Impairment of Tfh cell responses during the sensitization phase or Tfh cell depletion prevented Th2 cell-mediated responses following challenge. Thus, our data demonstrate that Tfh cells are precursors of HDM-specific Th2 cells and reveal an unexpected role of B cells and Tfh cells in the pathogenesis of allergic asthma.

  4. Molecular, Structural and Immunological Characterization of Der p 18, a Chitinase-Like House Dust Mite Allergen

    PubMed Central

    Resch, Yvonne; Blatt, Katharina; Malkus, Ursula; Fercher, Christian; Swoboda, Ines; Focke-Tejkl, Margit; Chen, Kuan-Wei; Seiberler, Susanne; Mittermann, Irene; Lupinek, Christian; Rodriguez-Dominguez, Azahara; Zieglmayer, Petra; Zieglmayer, René; Keller, Walter; Krzyzanek, Vladislav; Valent, Peter; Valenta, Rudolf; Vrtala, Susanne

    2016-01-01

    Background The house dust mite (HDM) allergen Der p 18 belongs to the glycoside hydrolase family 18 chitinases. The relevance of Der p 18 for house dust mite allergic patients has only been partly investigated. Objective To perform a detailed characterization of Der p 18 on a molecular, structural and immunological level. Methods Der p 18 was expressed in E. coli, purified to homogeneity, tested for chitin-binding activity and its secondary structure was analyzed by circular dichroism. Der p 18-specific IgG antibodies were produced in rabbits to localize the allergen in mites using immunogold electron microscopy and to search for cross-reactive allergens in other allergen sources (i.e. mites, crustacea, mollusca and insects). IgE reactivity of rDer p 18 was tested with sera from clinically well characterized HDM-allergic patients (n = 98) and its allergenic activity was analyzed in basophil activation experiments. Results Recombinant Der p 18 was expressed and purified as a folded, biologically active protein. It shows weak chitin-binding activity and partial cross-reactivity with Der f 18 from D. farinae but not with proteins from the other tested allergen sources. The allergen was mainly localized in the peritrophic matrix of the HDM gut and to a lower extent in fecal pellets. Der p 18 reacted with IgE from 10% of mite allergic patients from Austria and showed allergenic activity when tested for basophil activation in Der p 18-sensitized patients. Conclusion Der p 18 is a rather genus-specific minor allergen with weak chitin-binding activity but exhibits allergenic activity and therefore should be included in diagnostic test panels for HDM allergy. PMID:27548813

  5. Inflammatory and remodeling events in asthma with chronic exposure to house dust mites: a murine model.

    PubMed

    Ahn, Joong Hyun; Kim, Chi Hong; Kim, Yong Hyun; Kim, Seung Joon; Lee, Sook Young; Kim, Young Kyoon; Kim, Kwan Hyoung; Moon, Hwa Sik; Song, Jeong Sup; Park, Sung Hak; Kwon, Soon Seog

    2007-12-01

    Although animal models with ovalbumin have been used to study chronic asthma, there are difficulties in inducing recurrence as well as in maintaining chronic inflammation in this system. Using a murine model of house dust mite (HDM)-induced bronchial asthma, we examined the airway remodeling process in response to the chronic exposure to HDM. During the seventh and twelfth weeks of study, HDM were inhaled through the nose for three consecutive days and airway responsiveness was measured. Twenty-four hours later, bronchoalveolar lavage and histological examination were performed. The degree of overproduction of mucus, subepithelial fibrosis, and the thickness of the peribronchial smooth muscle in the experimental group was clearly increased compared to the control group. In addition, HDM-exposed mice demonstrated severe airway hyperreactivity to methacholine. In the bronchoalveolar lavage fluid, the number of total cells and eosinophils was increased; during the twelfth week, the number of neutrophils increased in the experimental group. With regard to changes in cytokines, the concentrations of IL-4, IL- 13, and transforming growth factor-beta (TGF-beta) were increased in the experimental group. The data suggest that eosinophils, IL-4, IL-13, and TGF-beta might play an important role in the airway remodeling process and that neutrophils may be involved with increased exposure time.

  6. The Guinea Pig Sensitized by House Dust Mite: A Model of Experimental Cough Studies.

    PubMed

    Buday, T; Gavliakova, S; Mokry, J; Medvedova, I; Kavalcikova-Bogdanova, N; Plevkova, J

    2016-01-01

    The guinea pig sensitized by ovalbumin is the most widely used model to study cough experimentally, as the neurophysiology of the vagus nerve in the guinea pig is closest to humans. Nonetheless, the choice of the antigen remains questionable, which influences the translation of results into clinical medicine. The present study seeks to develop an alternative model of cough study using house dust mite sensitization (HDM). Thirty guinea pigs were divided into the HDM group, ovalbumin (OVA) group, and control group based on their cough response to 0.4 M citric acid. In the HDM group animals were sensitized by 0.25 %HDM aerosol, which they inhaled for 5 min over 5 days, followed by inhalation of 0.5 %HDM in the same protocol. Sensitization was confirmed by a skin test. Symptoms of allergic rhinitis were induced by intranasal application of 15 μl 0.5 %HDM and cough challenges with citric acid were performed. Airway resistance was measured in vivo by Pennock's method. We found that both HDM and OVA-sensitized groups showed a significantly enhanced nasal reactivity and cough response compared with controls. The airway resistance data did not show significant differences. We conclude that the HDM cough model replicates functional aspects of the OVA model, which may make it an alternative to the latter. However, the superiority of the HDM model for experimental cough studies remains to be further explored. PMID:26987338

  7. Interleukin-21-Producing CD4(+) T Cells Promote Type 2 Immunity to House Dust Mites.

    PubMed

    Coquet, Jonathan M; Schuijs, Martijn J; Smyth, Mark J; Deswarte, Kim; Beyaert, Rudi; Braun, Harald; Boon, Louis; Karlsson Hedestam, Gunilla B; Nutt, Steven L; Hammad, Hamida; Lambrecht, Bart N

    2015-08-18

    Asthma is a T helper 2 (Th2)-cell-mediated disease; however, recent findings implicate Th17 and innate lymphoid cells also in regulating airway inflammation. Herein, we have demonstrated profound interleukin-21 (IL-21) production after house dust mite (HDM)-driven asthma by using T cell receptor (TCR) transgenic mice reactive to Dermatophagoides pteronyssinus 1 and an IL-21GFP reporter mouse. IL-21-producing cells in the mediastinal lymph node (mLN) bore characteristics of T follicular helper (Tfh) cells, whereas IL-21(+) cells in the lung did not express CXCR5 (a chemokine receptor expressed by Tfh cells) and were distinct from effector Th2 or Th17 cells. Il21r(-/-) mice developed reduced type 2 responses and the IL-21 receptor (IL-21R) enhanced Th2 cell function in a cell-intrinsic manner. Finally, administration of recombinant IL-21 and IL-25 synergistically promoted airway eosinophilia primarily via effects on CD4(+) lymphocytes. This highlights an important Th2-cell-amplifying function of IL-21-producing CD4(+) T cells in allergic airway inflammation.

  8. Immunotherapy for house dust mite sensitivity: where are the knowledge gaps?

    PubMed

    Biagtan, Mark; Viswanathan, Ravi; Bush, Robert K

    2014-12-01

    House dust mites (HDMs) are found in the environments where human habitation exists. Their density is dependent on environmental relative humidity; therefore, higher populations are present in areas of the world with higher humidity levels, e.g., coastal areas and tropics. To date, 24 HDM allergens have been identified. Many of these represent digestive enzymes since HDM feces are the major source of allergen exposure. IgE- medicated sensitization to HDM allergens is an important factor in the pathogenesis of allergic diseases since it is the most common aeroallergen detected by skin testing or in vitro IgE assays. Sensitization to HDM allergens often occurs early in life and appears to play an important role in the progression from allergic rhinitis to asthma (the so-called Allergic March) in children. HDM sensitization is also associated with asthma across all age groups. Efforts to control environmental exposure to HDM allergens have often proven to be unsuccessful. While medications can improve symptoms, only immunotherapy currently provides disease-modifying effects in allergic rhinitis and asthma. Several systemic reviews and meta-analysis indicate that both subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) are effective in the treatment of allergic rhinitis and asthma for HDM sensitivity. In this report, we review recent studies and the evidence for the use of HDM SCIT and SLIT. Fundamental gaps in knowledge are identified which could lead to improved approaches to HDM allergy. PMID:25354663

  9. Featured Image: Reddened Stars Reveal Andromeda's Dust

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-12-01

    As distant light travels on a path toward us, it can be absorbed by intervening, interstellar dust. Much work has been done to understand this dust extinction in the Milky Way, providing us with detailed information about the properties of the dust in our galaxy. Far less, however, is known about the dust extinction of other galaxies. The image above, taken with the ultraviolet space telescope GALEX, identifies the locations of four stars in the nearby Andromeda galaxy (click for a full view!) that are reddened due to extinction of their light by dust within Andromeda. In a recent study led by Geoffrey Clayton (Louisiana State University), new, high-signal-to-noise spectra were obtained for these four stars using Hubbles Space Telescope Imaging Spectrograph. These observations have allowed the authors to construct dust extinction curves to carefully study the nature of Andromedas interstellar dust. To learn about the results, see the paper below.CitationGeoffrey C. Clayton et al 2015 ApJ 815 14. doi:10.1088/0004-637X/815/1/14

  10. Asthma, Airway Symptoms and Rhinitis in Office Workers in Malaysia: Associations with House Dust Mite (HDM) Allergy, Cat Allergy and Levels of House Dust Mite Allergens in Office Dust

    PubMed Central

    Lim, Fang Lee; Hashim, Zailina; Than, Leslie Thian Lung; Md Said, Salmiah; Hisham Hashim, Jamal; Norbäck, Dan

    2015-01-01

    A prevalence study was conducted among office workers in Malaysia (N= 695). The aim of this study was to examine associations between asthma, airway symptoms, rhinitis and house dust mites (HDM) and cat allergy and HDM levels in office dust. Medical data was collected by a questionnaire. Skin prick tests were performed for HDM allergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae) and cat allergen Felis domesticus. Indoor temperature and relative air humidity (RH) were measured in the offices and vacuumed dust samples were analyzed for HDM allergens. The prevalence of D. pteronyssinus, D. farinae and cat allergy were 50.3%, 49.0% and 25.5% respectively. Totally 9.6% had doctor-diagnosed asthma, 15.5% had current wheeze and 53.0% had current rhinitis. The Der p 1 (from D. pteronyssinus) and Der f 1 (from D. farinae) allergens levels in dust were 556 ng/g and 658 ng/g respectively. Statistical analysis was conducted by multilevel logistic regression, adjusting for age, gender, current smoking, HDM or cat allergy, home dampness and recent indoor painting at home. Office workers with HDM allergy had more wheeze (p= 0.035), any airway symptoms (p= 0.032), doctor-diagnosed asthma (p= 0.005), current asthma (p= 0.007), current rhinitis (p= 0.021) and rhinoconjuctivitis (p< 0.001). Cat allergy was associated with wheeze (p= 0.021), wheeze when not having a cold (p= 0.033), any airway symptoms (p= 0.034), doctor-diagnosed asthma (p= 0.010), current asthma (p= 0.020) and nasal allergy medication (p= 0.042). Der f 1 level in dust was associated with daytime breathlessness (p= 0.033) especially among those with HDM allergy. Der f 1 levels were correlated with indoor temperature (p< 0.001) and inversely correlated with RH (p< 0.001). In conclusion, HDM and cat allergies were common and independently associated with asthma, airway symptoms and rhinitis. Der f 1 allergen can be a risk factor for daytime breathlessness. PMID:25923543

  11. The effects of a newsletter on bedding control on house dust mite allergen concentrations in childcare centers in Korea

    PubMed Central

    Kim, Jeonghoon; Jeong, Kyoung Yong; Kwon, Ho-Jang; Yang, Heasuk; Yum, Hye Yung; Lee, Seon Ah; Kim, Chae-Bong; Kim, Hyunjung; Lim, Wan Ryung; Hong, Soyoung; Kim, Kyoosang

    2015-01-01

    Objectives Bedding in childcare centers (CCCs) can hold house dust mite (HDM) allergens. This study examined whether HDM allergen levels can be reduced through the distribution of an educational newsletter on bedding control to parents of CCC children in Korea. Methods All 38 CCCs were measured for Der 1 (sum of Der f 1 and Der p 1) concentrations on classroom floors and bedding before the intervention. Educational newsletters on children’s bedding control were sent to 21 CCCs by mail, and teachers were asked to distribute the newsletters to the parents of the children (intervention group). The remaining 17 CCCs were not sent newsletters (control group). The measurement of Der 1 concentrations in 38 CCCs was repeated after the intervention. Dust samples were collected with a vacuum cleaner and analyzed using enzyme-linked immunosorbent assay methods. Results The Der 1 concentrations on the bedding were significantly higher than those on the floors in 38 CCCs at baseline (p<0.05). Although changes of the Der 1 concentrations for the control group (n=17) were not significant, Der 1 concentrations for the intervention group (n=21) decreased significantly from 2077.9 ng/g dust to 963.5 ng/g dust on the floors and from 3683.9 ng/g dust to 610.4 ng/g dust on bedding (p<0.05). Conclusions The distribution of educational newsletters on bedding control to parents may be an effective means of controlling HDMs in CCCs. PMID:26602559

  12. Acetaminophen Attenuates House Dust Mite-Induced Allergic Airway Disease in Mice.

    PubMed

    Smith, Gregory J; Thrall, Roger S; Cloutier, Michelle M; Manautou, Jose E; Morris, John B

    2016-09-01

    Epidemiologic evidence suggests that N-acetyl-para-aminophenol (APAP) may play a role in the pathogenesis of asthma, likely through pro-oxidant mechanisms. However, no studies have investigated the direct effects of APAP on the development of allergic inflammation. To determine the likelihood of a causal relationship between APAP and asthma pathogenesis, we explored the effects of APAP on inflammatory responses in a murine house dust mite (HDM) model of allergic airway disease. We hypothesized that APAP would enhance the development of HDM-induced allergic inflammation. The HDM model consisted of once daily intranasal instillations for up to 2 weeks with APAP or vehicle administration 1 hour prior to HDM during either week 1 or 2. Primary assessment of inflammation included bronchoalveolar lavage (BAL), cytokine expression in lung tissue, and histopathology. Contrary to our hypothesis, the effects of HDM treatment were substantially diminished in APAP-treated groups compared with controls. APAP-treated groups had markedly reduced airway inflammation: including decreased inflammatory cells in the BAL fluid, lower cytokine expression in lung tissue, and less perivascular and peribronchiolar immune cell infiltration. The anti-inflammatory effect of APAP was not abrogated by an inhibitor of cytochrome P450 (P450) metabolism, suggesting that the effect was due to the parent compound or a non-P450 generated metabolite. Taken together, our studies do not support the biologic plausibility of the APAP hypothesis that APAP use may contribute to the causation of asthma. Importantly, we suggest the mechanism by which APAP modulates airway inflammation may provide novel therapeutic targets for asthma. PMID:27402277

  13. Neonatal exposure to pneumococcal phosphorylcholine modulates the development of house dust mite allergy during adult life.

    PubMed

    Patel, Preeyam S; Kearney, John F

    2015-06-15

    Currently, ∼20% of the global population suffers from an allergic disorder. Allergies and asthma occur at higher rates in developed and industrialized countries. It is clear that many human atopic diseases are initiated neonatally and herald more severe IgE-mediated disorders, including allergic asthma, which is driven by the priming of Th2 effector T cells. The hygiene hypothesis attempts to link the increased excessively sanitary conditions early in life to a default Th2 response and increasing allergic phenomena. Despite the substantial involvement of IgE Abs in such conditions, little attention has been paid to the effects of early microbial exposure on the B cell repertoire prior to the initiation of these diseases. In this study, we use Ab-binding assays to demonstrate that Streptococcus pneumoniae and house dust mite (HDM) bear similar phosphorylcholine (PC) epitopes. Neonatal C57BL/6 mice immunized with a PC-bearing pneumococcal vaccine expressed increased frequencies of PC-specific B cells in the lungs following sensitizing exposure to HDM as adults. Anti-PC IgM Abs in the lung decreased the interaction of HDM with pulmonary APCs and were affiliated with lowered allergy-associated cell infiltration into the lung, IgE production, development of airway hyperresponsiveness, and Th2 T cell priming. Thus, exposure of neonatal mice to PC-bearing pneumococci significantly reduced the development of HDM-induced allergic disease during adult life. Our findings demonstrate that B cells generated against conserved epitopes expressed by bacteria, encountered early in life, are also protective against the development of allergic disease during adult life. PMID:25957171

  14. Suppression of dust mite allergy by mucosal delivery of a hypoallergenic derivative in a mouse model.

    PubMed

    Ai, Chunqing; Zhang, Qiuxiang; Ding, Junrong; Ren, Chengcheng; Wang, Gang; Liu, Xiaoming; Tian, Fengwei; Zhao, Jianxin; Zhang, Hao; Chen, Yong Q; Chen, Wei

    2015-05-01

    Allergic asthma caused by house dust mite (HDM) is becoming a public health problem. Specific immunotherapy is considered to be the only curative treatment, but it is always associated with IgE-mediated side effects in the therapy process. A few studies showed that the disruption of allergen IgE epitopes could reduce IgE reactivity and thus reduce allergenic activity. In this study, a hypoallergenic derivative of the major HDM allergen Der p2 was constructed by genetic engineering. This derivative was confirmed to have a considerably reduced IgE reactivity compared with Der p2. For its application in vivo, recombinant Lactococcus lactis (LL-DM) was engineered to deliver the Der p2 derivative to the intestinal mucosal surface. Oral administration of LL-DM significantly alleviated Der p2-induced airway inflammation, as shown by reduced inflammatory infiltration and a reduction in Th2 cytokines in bronchoalveolar lavage. This protective effect was associated with an up-regulation of specific IgG2a and a decrease in IL-4 level in the spleen which may affect specific IgE response. Moreover, the levels of regulatory T cells in the mesenteric lymph nodes and spleen were markedly increased in mice fed with LL-DM, suggesting that LL-DM can inhibit allergic responses via the induction of regulatory T cell. Our results indicate that the Der p2 derivative is a promising therapeutic molecule for specific immunotherapy and recombinant lactic acid bacteria could be developed as a promising treatment or prevention strategy for allergic diseases.

  15. Neonatal Exposure to Pneumococcal Phosphorylcholine Modulates the Development of House Dust Mite Allergy during Adult Life

    PubMed Central

    Patel, Preeyam S.

    2015-01-01

    Currently, ∼20% of the global population suffers from an allergic disorder. Allergies and asthma occur at higher rates in developed and industrialized countries. It is clear that many human atopic diseases are initiated neonatally and herald more severe IgE-mediated disorders, including allergic asthma, which is driven by the priming of Th2 effector T cells. The hygiene hypothesis attempts to link the increased excessively sanitary conditions early in life to a default Th2 response and increasing allergic phenomena. Despite the substantial involvement of IgE Abs in such conditions, little attention has been paid to the effects of early microbial exposure on the B cell repertoire prior to the initiation of these diseases. In this study, we use Ab-binding assays to demonstrate that Streptococcus pneumoniae and house dust mite (HDM) bear similar phosphorylcholine (PC) epitopes. Neonatal C57BL/6 mice immunized with a PC-bearing pneumococcal vaccine expressed increased frequencies of PC-specific B cells in the lungs following sensitizing exposure to HDM as adults. Anti-PC IgM Abs in the lung decreased the interaction of HDM with pulmonary APCs and were affiliated with lowered allergy-associated cell infiltration into the lung, IgE production, development of airway hyperresponsiveness, and Th2 T cell priming. Thus, exposure of neonatal mice to PC-bearing pneumococci significantly reduced the development of HDM-induced allergic disease during adult life. Our findings demonstrate that B cells generated against conserved epitopes expressed by bacteria, encountered early in life, are also protective against the development of allergic disease during adult life. PMID:25957171

  16. The Effects of Storage Conditions on the Stability of House Dust Mite Extracts

    PubMed Central

    Jeong, Kyoung Yong; Choi, Soo-Young; Han, In-Soo; Lee, Jae-Hyun; Lee, Joo-Shil; Hong, Chein-Soo

    2013-01-01

    Purpose Allergen extracts from the house dust mite (HDM, Dermatophagoides pteronyssinus) are widely utilized for diagnosis and treatment of allergic diseases. It is known that allergen extracts degrade and lose potency when stored over time. Methods This study aimed to determine the optimal conditions for stability of allergen extracts. This study was undertaken to investigate the optimal storage conditions for HDM extracts, the effects of adding 0.03% human serum albumin (HSA) and 50% glycerol were evaluated at -20℃, 4℃, and room temperature (RT). Changes in protein and group 1 major allergen (Der p 1) concentration, as well as allergenicity were measured over a 1 year period using the Bradford assay, two-site ELISA, and ELISA inhibition. Results Protein concentrations decreased by 86%, 51%, and 6% at RT, 4℃, and -20℃, respectively, when stored in distilled water. Overall allergenicity remained high (89.9%) when the extracts was reconstituted in 50% glycerol solution, and was 93.1% when reconstituted in 50% glycerol and 0.03% HSA at RT. Allergenicity was decreased to 36.6% and 33.3%, however, reconstitution in DW or 0.03% HSA solution at RT, respectively. Allergenicity was remained high as 92.0%-97.0% when stored at 4℃ regardless of the buffer conditions. Conclusions Storage temperature is the most important factor in preserving allergenicity of HDM extracts, which is ideal at 4℃. The addition of 50% glycerol to the storage buffer was also found to play an important role in increasing the shelf-life of HDM extracts at RT. PMID:24179687

  17. Gene-by-environment effect of house dust mite on purinergic receptor P2Y12 (P2RY12) and lung function in children with asthma

    PubMed Central

    Bunyavanich, Supinda; Boyce, Joshua A.; Raby, Benjamin A.; Weiss, Scott T.

    2012-01-01

    Background Distinct receptors likely exist for leukotriene(LT)E4, a potent mediator of airway inflammation. Purinergic receptor P2Y12 is needed for LTE4-induced airways inflammation, and P2Y12 antagonism attenuates house dust mite-induced pulmonary eosinophilia in mice. Although experimental data support a role for P2Y12 in airway inflammation, its role in human asthma has never been studied. Objective To test for association between variants in the P2Y12 gene (P2RY12) and lung function in human subjects with asthma, and to examine for gene-by-environment interaction with house dust mite exposure. Methods 19 single nucleotide polymorphisms (SNPs) in P2RY12 were genotyped in 422 children with asthma and their parents (n=1266). Using family-based methods, we tested for associations between these SNPs and five lung function measures. We performed haplotype association analyses and tested for gene-by-environment interactions using house dust mite exposure. We used the false discovery rate to account for multiple comparisons. Results Five SNPs in P2RY12 were associated with multiple lung function measures (P values 0.006–0.025). Haplotypes in P2RY12 were also associated with lung function (P values 0.0055–0.046). House dust mite exposure modulated associations between P2RY12 and lung function, with minor allele homozygotes exposed to house dust mite demonstrating worse lung function than those unexposed (significant interaction P values 0.0028–0.040). Conclusions and clinical relevance P2RY12 variants were associated with lung function in a large family-based asthma cohort. House dust mite exposure caused significant gene-by-environment effects. Our findings add the first human evidence to experimental data supporting a role for P2Y12 in lung function. P2Y12 could represent a novel target for asthma treatment. PMID:22010907

  18. Der p 11 Is a Major Allergen for House Dust Mite-Allergic Patients Suffering from Atopic Dermatitis

    PubMed Central

    Banerjee, Srinita; Resch, Yvonne; Chen, Kuan-Wei; Swoboda, Ines; Focke-Tejkl, Margit; Blatt, Katharina; Novak, Natalija; Wickman, Magnus; van Hage, Marianne; Ferrara, Rosetta; Mari, Adriano; Purohit, Ashok; Pauli, Gabrielle; Sibanda, Elopy N.; Ndlovu, Portia; Thomas, Wayne R.; Krzyzanek, Vladislav; Tacke, Sebastian; Malkus, Ursula; Valent, Peter; Valenta, Rudolf; Vrtala, Susanne

    2015-01-01

    House dust mites (HDMs) belong to the most potent indoor allergen sources worldwide and are associated with allergic manifestations in the respiratory tract and the skin. Here we studied the importance of the high-molecular-weight group 11 allergen from Dermatophagoides pteronyssinus (Der p 11) in HDM allergy. Sequence analysis showed that Der p 11 has high homology to paramyosins from mites, ticks, and other invertebrates. A synthetic gene coding for Der p 11 was expressed in Escherichia coli and rDer p 11 purified to homogeneity as folded, alpha-helical protein as determined by circular dichroism spectroscopy. Using antibodies raised against rDer p 11 and immunogold electron microscopy, the allergen was localized in the muscle beneath the skin of mite bodies but not in feces. IgE reactivity of rDer p 11 was tested with sera from HDM-allergic patients from Europe and Africa in radioallergosorbent test–based dot-blot assays. Interestingly, we found that Der p 11 is a major allergen for patients suffering from atopic dermatitis (AD), whereas it is only a minor allergen for patients suffering from respiratory forms of HDM allergy. Thus, rDer p 11 might be a useful serological marker allergen for the identification of a subgroup of HDM-allergic patients suffering from HDM-associated AD. PMID:24999597

  19. Conversion of Der p 23, a New Major House Dust Mite Allergen, into a Hypoallergenic Vaccine

    PubMed Central

    Banerjee, Srinita; Weber, Milena; Blatt, Katharina; Swoboda, Ines; Focke-Tejkl, Margit; Valent, Peter; Valenta, Rudolf; Vrtala, Susanne

    2015-01-01

    Der p 23, a new, major house dust mite (HDM) allergen that is recognized by >70% of HDM-allergic patients, has high allergenic activity and, therefore, must be considered an important component for HDM-specific immunotherapy. We constructed and characterized a hypoallergenic Der p 23 vaccine for HDM immunotherapy. Three nonallergenic peptides from the C-terminal IgE epitope-containing part of Der p 23 (P4, P5) and P6, a mutant peptide containing serines instead of cysteines, were identified. Peptides were fused to the hepatitis B virus–derived PreS domain as recombinant fusion proteins (i.e., PreS-2XP4P5 and PreS-4XP6) that were expressed in Escherichia coli and purified to homogeneity. Compared with Der p 23, PreS-2XP4P5 and PreS-4XP6 showed no relevant IgE reactivity and exhibited considerably reduced allergenic activity in basophil activation tests using blood from HDM-allergic patients. Upon immunization of rabbits, only PreS-2XP4P5 induced high levels of Der p 23–specific IgG Abs that inhibited binding of patients’ IgE to Der p 23, comparable to IgG Abs induced with Der p 23, whereas Abs induced with PreS-4XP6 had only low blocking capacity. Additionally, IgG Abs induced with PreS-2XP4P5 inhibited Der p 23–induced basophil activation comparable to IgG Abs induced with Der p 23. Compared with Der p 23, PreS-2XP4P5 induced lower T cell proliferation but higher levels of the tolerogenic cytokine IL-10 and the Th1 cytokine IFN-γ in PBMCs from HDM-allergic patients, indicating an immunomodulatory capacity of the fusion protein. Therefore, PreS-2XP4P5 represents a promising candidate for immunotherapy of HDM-allergic patients. PMID:24733847

  20. CHARACTERIZATION OF IMMEDIATE AND LATE PHASE AIRWAY RESPONSES TO HOUSE DUST MITE CHALLENGE IN BROWN NORWAY RATS AND CORRELATIONS AMONG PHYSIOLOGICAL MEDIATORS

    EPA Science Inventory

    CHARACTERIZATION OF IMMEDIATE AND LATE PHASE AIRWAY RESPONSES TO HOUSE DUST MITE CHALLENGE IN BROWN NORWAY RATS AND CORRELATIONS AMONG PATHOPHYSIOLOGICAL MEDIATORS (P.
    SinghI, D.W. Winsett2, M.J. Daniels2, J. Richards2, K. Crissman2, D.L. Doerfler2 and M.I. Gilmour2, 1NCSU, Ra...

  1. Interference in foraging behaviour of European and American house dust mites Dermatophagoides pteronyssinus and Dermatophagoides farinae (Acari: Pyroglyphidae) by catmint, Nepeta cataria (Lamiaceae).

    PubMed

    Khan, M A; Jones, I; Loza-Reyes, E; Cameron, M M; Pickett, J A; Birkett, M A

    2012-05-01

    The European and American house dust mites, Dermatophagoides pteronyssinus and D. farinae, have a huge impact upon human health worldwide due to being the most important indoor trigger of atopic diseases such as asthma, rhinitis and atopic dermatitis. Preceding studies have shown that the behavioural response of house dust mites towards volatile chemicals from food sources can be assessed using a Y-tube olfactometer assay. In the current study, we used this assay to investigate, for the first time, the ability of the essential oil of the catmint plant, Nepeta cataria (Lamiaceae), known to repel other ectoparasites affecting human and animal health, to interfere with the attraction of D. pteronyssinus and D. farinae towards a standard food source (fish flakes). Two distinct chemotypes (A and B), enriched in the iridoid compounds (4aS,7S,7aR)-nepetalactone and (4aS,7S,7aS)-nepetalactone, and the sesquiterpene (E)-(1R,9S)-caryophyllene, were used. Initial assays with a hexane extract of fish flakes (FF extract) confirmed attraction of mites to this positive control (P < 0.001 and P < 0.05 for D. pteronyssinus and D. farinae respectively), but when presented in combination with either N. cataria chemotype, tested across a range of doses (10, 1, 0.1 and 0.01 μg), decreasing attraction of mites to their food source was observed as the dose augmented. Our study shows that N. cataria, enriched in iridoid nepetalactones and (E)-(1R,9S)-caryophyllene, exhibits potent repellent activity for house dust mites, and has the potential for deployment in control programmes based on interference with normal house dust mite behaviour.

  2. Interference in foraging behaviour of European and American house dust mites Dermatophagoides pteronyssinus and Dermatophagoides farinae (Acari: Pyroglyphidae) by catmint, Nepeta cataria (Lamiaceae).

    PubMed

    Khan, M A; Jones, I; Loza-Reyes, E; Cameron, M M; Pickett, J A; Birkett, M A

    2012-05-01

    The European and American house dust mites, Dermatophagoides pteronyssinus and D. farinae, have a huge impact upon human health worldwide due to being the most important indoor trigger of atopic diseases such as asthma, rhinitis and atopic dermatitis. Preceding studies have shown that the behavioural response of house dust mites towards volatile chemicals from food sources can be assessed using a Y-tube olfactometer assay. In the current study, we used this assay to investigate, for the first time, the ability of the essential oil of the catmint plant, Nepeta cataria (Lamiaceae), known to repel other ectoparasites affecting human and animal health, to interfere with the attraction of D. pteronyssinus and D. farinae towards a standard food source (fish flakes). Two distinct chemotypes (A and B), enriched in the iridoid compounds (4aS,7S,7aR)-nepetalactone and (4aS,7S,7aS)-nepetalactone, and the sesquiterpene (E)-(1R,9S)-caryophyllene, were used. Initial assays with a hexane extract of fish flakes (FF extract) confirmed attraction of mites to this positive control (P < 0.001 and P < 0.05 for D. pteronyssinus and D. farinae respectively), but when presented in combination with either N. cataria chemotype, tested across a range of doses (10, 1, 0.1 and 0.01 μg), decreasing attraction of mites to their food source was observed as the dose augmented. Our study shows that N. cataria, enriched in iridoid nepetalactones and (E)-(1R,9S)-caryophyllene, exhibits potent repellent activity for house dust mites, and has the potential for deployment in control programmes based on interference with normal house dust mite behaviour. PMID:22382713

  3. Savings associated with high-dose hypoallergenic house dust mite immunotherapy in rhinitis and/or asthma patients in Spain

    PubMed Central

    García Robaina, José Carlos; Polanco Sánchez, Carlos; Estella Pérez, Elvira

    2016-01-01

    Objectives To quantify the cost difference between conventional symptomatic treatment of mite allergy and specific subcutaneous immunotherapy (SCIT). Methods Observational, retrospective, and multicenter study was carried out in Spain in 2013. The medical records of 419 patients diagnosed with rhinitis and/or bronchial asthma for mite allergy were retrieved. Mean age was 24.9 years (standard deviation 14.4). The use of symptomatic medication (rescue and daily), diagnostic tests, unscheduled medical care, and sick leave days associated with SCIT treatment versus no-SCIT treatment was compared. Also measured was the SCIT treatment to no-SCIT treatment costs ratio: used resources (symptomatic medication, unscheduled medical care, diagnostic tests, and 3 years SCIT treatment and sick leave days) were quantified in euros. Efficacy (decreased resource usage) of first-year treatment was assumed during the remaining 2 years and also during the 3-year follow-up period. Results After a single year of SCIT, all quantified resources diminished significantly (P<0.05) from baseline. Estimated reduction in cost items included hospital resources (100% in hospitalizations, 82% in visits to the allergist, and 79% in emergency room visits), therapies (56% in rescue medication and 63% in daily medication), diagnostic tests (77%), and sick leave days (94%). Ratio of comparative calculation described as SCIT treatment versus non-SCIT treatment (or conventional symptomatic treatment) is 0.8. Conclusion Direct costs are reduced by 64% and indirect costs by 94%. SCIT of hypoallergenic preparation of dust mite (Acaroid®) allows cost savings versus conventional treatment. Estimated savings for the public National Health System are 5.7 times the cost of immunotherapy. PMID:27366098

  4. VLBA Reveals Dust-Enshrouded "Supernova Factory"

    NASA Astrophysics Data System (ADS)

    2003-05-01

    Using the National Science Foundation's Very Long Baseline Array (VLBA) radio telescope, astronomers have discovered a newly-exploded star, or supernova, hidden deep in a dust-enshrouded "supernova factory" in a galaxy some 140 million light-years from Earth. "This supernova is likely to be part of a group of super star clusters that produce one such stellar explosion every two years," said James Ulvestad, of the National Radio Astronomy Observatory (NRAO) in Socorro, NM. "We're extremely excited by the tremendous insights into star formation and the early Universe that we may gain by observing this 'supernova factory,'" he added. Ulvestad worked with Susan Neff of NASA's Goddard Space Flight Center in Greenbelt, MD, and Stacy Teng, a graduate student at the University of Maryland, on the project. The scientists presented their findings to the American Astronomical Society's meeting in Nashville, TN. "These super star clusters likely are forming in much the same way that globular clusters formed in the early Universe, and thus provide us with a unique opportunity to learn about how some of the first stars formed billions of years ago," Neff said. The cluster is in an object called Arp 299, a pair of colliding galaxies, where regions of vigorous star formation have been found in past observations. Since 1990, four other supernova explosions have been seen optically in Arp 299. Observations with the NSF's Very Large Array (VLA) earlier showed a region near the nucleus of one of the colliding galaxies which had all the earmarks of prolific star formation. The astronomers focused on this region, prosaically dubbed "Source A," with the VLBA and the NSF's Robert C. Byrd Green Bank Telescope in 2002, and found four objects in this dusty cloud that are likely young supernova remnants. When they observed the region again in February 2003, there was a new, fifth, object located only 7 light-years from one of the previously detected objects. More observations on April 30-May

  5. Group 10 allergens (tropomyosins) from house-dust mites may cause covariation of sensitization to allergens from other invertebrates

    PubMed Central

    Inam, Muhammad; Ismail, Muhammad; Chaudhary, Farhana Riaz

    2012-01-01

    Group 10 allergens (tropomyosins) have been assumed to be a major cause of cross-reactivity between house-dust mites (HDMs) and other invertebrates. Despite all of the published data regarding the epidemiology, percent IgE binding and level of sensitization in the population, the role of tropomyosin as a cross-reactive allergen in patients with multiple allergy syndrome still remains to be elucidated. Homology between amino acid sequences reported in allergen databases of selected invertebrate tropomyosins was determined with Der f 10 as the reference allergen. The 66.9 and 54.4% identities were found with selected crustacean and insect species, respectively, whereas only 20.4% identity was seen with mollusks. A similar analysis was performed using reported B-cell IgE-binding epitopes from Met e1 (shrimp allergen) and Bla g7 (cockroach allergen) with other invertebrate tropomyosins. The percent identity in linear sequences was higher than 35% in mites, crustaceans, and cockroaches. The polar and hydrophobic regions in these groups were highly conserved. These findings suggest that tropomyosin may be a major cause of covariation of sensitization between HDMs, crustaceans, and some species of insects and mollusks. PMID:23342293

  6. Genetically Engineered Lactococcus lactis Protect against House Dust Mite Allergy in a BALB/c Mouse Model

    PubMed Central

    Ai, Chunqing; Zhang, Qiuxiang; Ren, Chengcheng; Wang, Gang; Liu, Xiaoming; Tian, Fengwei; Zhao, Jianxin; Zhang, Hao; Chen, Yong Q.; Chen, Wei

    2014-01-01

    Background Mucosal vaccine based on lactic acid bacteria is an attractive concept for the prevention and treatment of allergic diseases, but their mechanisms of action in vivo are poorly understood. Therefore, we sought to investigate how recombinant major dust mite allergen Der p2-expressing Lactococcus lactis as a mucosal vaccine induced the immune tolerance against house dust mite allergy in a mouse model. Methods Three strains of recombinant L. lactis producing Der p2 in different cell components (extracellular, intracellular and cell wall) were firstly constructed. Their prophylactic potential was evaluated in a Der p2-sensitised mouse model, and immunomodulation properties at the cellular level were determined by measuring cytokine production in vitro. Results Der p2 expressed in the different recombinant L. lactis strains was recognized by a polyclonal anti-Der p2 antibody. Oral treatment with the recombinant L. lactis prior sensitization significantly prevented the development of airway inflammation in the Der p2-sensitized mice, as determined by the attenuation of inflammatory cells infiltration in the lung tissues and decrease of Th2 cytokines IL-4 and IL-5 levels in bronchoalveolar lavage. In addition, the serum allergen-specific IgE levels were significantly reduced, and the levels of IL-4 in the spleen and mesenteric lymph nodes cell cultures were also markedly decreased upon allergen stimulation in the mice fed with the recombinant L. lactis strains. These protective effects correlated with a significant up-regulation of regulatory T cells in the mesenteric lymph nodes. Conclusion Oral pretreatment with live recombinant L. lactis prevented the development of allergen-induced airway inflammation primarily by the induction of specific mucosal immune tolerance. PMID:25290938

  7. THREE-DIMENSIONAL DUST MAPPING REVEALS THAT ORION FORMS PART OF A LARGE RING OF DUST

    SciTech Connect

    Schlafly, E. F.; Rix, H.-W.; Martin, N. F.; Green, G.; Finkbeiner, D. P.; Burgett, W. S.; Chambers, K. C.; Kaiser, N.; Morgan, J. S.; Tonry, J. L.; Wainscoat, R. J.; Waters, C.; Draper, P. W.; Metcalfe, N.; Price, P. A.

    2015-02-01

    The Orion Molecular Complex is the nearest site of ongoing high-mass star formation, making it one of the most extensively studied molecular complexes in the Galaxy. We have developed a new technique for mapping the three-dimensional distribution of dust in the Galaxy using Pan-STARRS1 photometry. We isolate the dust at the distance to Orion using this technique, revealing a large (100 pc, 14° diameter), previously unrecognized ring of dust, which we term the ''Orion dust ring''. The ring includes Orion A and B, and is not coincident with current Hα features. The circular morphology suggests formation as an ancient bubble in the interstellar medium, though we have not been able to conclusively identify the source of the bubble. This hint at the history of Orion may have important consequences for models of high-mass star formation and triggered star formation.

  8. Mites and allergy.

    PubMed

    Fernández-Caldas, Enrique; Puerta, Leonardo; Caraballo, Luis

    2014-01-01

    Allergic diseases triggered by mite allergens include allergic rhinoconjunctivitis, asthma, atopic dermatitis and other skin diseases. Since the early discovery of the allergenic role of mites of the genus Dermatophagoides in the mid 1960s, numerous species have been described as the source of allergens capable of sensitizing and inducing allergic symptoms in sensitized and genetically predisposed individuals. The main sources of allergens in house dust worldwide are the fecal pellets of the mite species D. pteronyssinus, D. farinae, Euroglyphus maynei and the storage mites Blomia tropicalis, Lepidoglyphus destructor and Tyropahgus putrescentiae. Group 1 and 2 allergens are major house dust mite allergens. The main allergens in storage mites include fatty acid-binding proteins, tropomyosin and paramyosin homologues, apolipophorin-like proteins, α-tubulins and others, such as group 2, 5 and 7 allergens. Cross-reactivity is an important and common immunological feature among mites. Currently, purified native or recombinant allergens, epitope mapping, proteomic approaches and T cell proliferation techniques are being used to assess cross-reactivity. Mites contain potent enzymes capable of degrading a wide range of substrates. Most mite allergens are enzymes. Advances in genomics and molecular biology will improve our ability to understand the genetics of specific IgE responses to mites. Mite allergen avoidance and immunotherapy are the only two allergen-specific ways to treat mite-induced respiratory and cutaneous diseases.

  9. MHC Class II-Restricted Presentation of the Major House Dust Mite Allergen Der p 1 Is GILT-Dependent: Implications for Allergic Asthma

    PubMed Central

    West, Laura Ciaccia; Grotzke, Jeff E.; Cresswell, Peter

    2013-01-01

    Gamma-interferon-inducible lysosomal thiol reductase (GILT) is known to reduce disulfide bonds present in proteins internalized by antigen presenting cells, facilitating optimal processing and presentation of peptides on Major Histocompatibility Complex class II molecules, as well as the subsequent activation of CD4-positive T lymphocytes. Here, we show that GILT is required for class II-restricted processing and presentation of immunodominant epitopes from the major house dust mite allergen Der p 1. In the absence of GILT, CD4-positive T cell responses to Der p 1 are significantly reduced, resulting in mitigated allergic airway inflammation in response to Der p 1 and house dust mite extracts in a murine model of asthma. PMID:23326313

  10. Postnatal growth rate, but not mild preterm birth, influences airway structure in adult sheep challenged with house dust mite.

    PubMed

    Snibson, Ken; Harding, Richard

    2008-02-01

    The authors recently showed that preterm birth per se, in the absence of assisted ventilation or elevated inhaled oxygen levels, alters the structure of the airway walls in young lambs. The initial aim of the present study was to determine whether these changes persist into adulthood. Preterm (P; n = 7) lambs were delivered 14 days before term and compared with control lambs (C; n = 8) born at term ( approximately 147 days). After weaning, the sheep were kept as a flock with daily exposure to pasture until approximately 1.2 years old. All sheep were sensitized to house dust mite extract and then given aerosol challenges with house dust mite 10 to 12 weeks before autopsy. At autopsy, the right lung was fixed in neutral-buffered formalin at an inflation pressure of 20 cm H(2)O. The architecture of the walls of airway generations 4, 6, and 8 and the bronchioles was assessed by computer-aided image analysis of histological sections of airway walls cut in cross-section. Morphometric analysis showed that preterm birth per se had no significant effect on airway wall structure. Within both groups (preterm and term), we identified animals that grew at different growth rates after birth; a second aim, therefore, was to determine the influence of postnatal growth rates on airway structure at maturity. The 15 sheep were divided into 2 groups based on nonoverlapping growth rates between birth and 200 days of age: slower growing sheep (SG; n = 7) gained 102 +/- 5 g/day and faster growing sheep (FG; n = 8) gained 197 +/- 14 g/day (P < .01). In SG sheep, the pulmonary airways had thinner walls and less smooth muscle in relation to basement membrane perimeter. The airway epithelium was also thinner in the SG sheep. In the bronchiolar epithelium, there were fewer goblet cells and Clara cells in SG compared to FG sheep. We conclude that the early effects of preterm birth on the airway epithelium do not persist to maturity. However, slow growth after birth results in altered airway

  11. Conventional and monocyte-derived CD11b(+) dendritic cells initiate and maintain T helper 2 cell-mediated immunity to house dust mite allergen.

    PubMed

    Plantinga, Maud; Guilliams, Martin; Vanheerswynghels, Manon; Deswarte, Kim; Branco-Madeira, Filipe; Toussaint, Wendy; Vanhoutte, Leen; Neyt, Katrijn; Killeen, Nigel; Malissen, Bernard; Hammad, Hamida; Lambrecht, Bart N

    2013-02-21

    Dendritic cells (DCs) are crucial for mounting allergic airway inflammation, but it is unclear which subset of DCs performs this task. By using CD64 and MAR-1 staining, we reliably separated CD11b(+) monocyte-derived DCs (moDCs) from conventional DCs (cDCs) and studied antigen uptake, migration, and presentation assays of lung and lymph node (LN) DCs in response to inhaled house dust mite (HDM). Mainly CD11b(+) cDCs but not CD103(+) cDCs induced T helper 2 (Th2) cell immunity in HDM-specific T cells in vitro and asthma in vivo. Studies in Flt3l(-/-) mice, lacking all cDCs, revealed that moDCs were also sufficient to induce Th2 cell-mediated immunity but only when high-dose HDM was given. The main function of moDCs was the production of proinflammatory chemokines and allergen presentation in the lung during challenge. Thus, we have identified migratory CD11b(+) cDCs as the principal subset inducing Th2 cell-mediated immunity in the LN, whereas moDCs orchestrate allergic inflammation in the lung.

  12. Genome Sequencing of the Phytoseiid Predatory Mite Metaseiulus occidentalis Reveals Completely Atomized Hox Genes and Superdynamic Intron Evolution.

    PubMed

    Hoy, Marjorie A; Waterhouse, Robert M; Wu, Ke; Estep, Alden S; Ioannidis, Panagiotis; Palmer, William J; Pomerantz, Aaron F; Simão, Felipe A; Thomas, Jainy; Jiggins, Francis M; Murphy, Terence D; Pritham, Ellen J; Robertson, Hugh M; Zdobnov, Evgeny M; Gibbs, Richard A; Richards, Stephen

    2016-01-01

    Metaseiulus occidentalis is an eyeless phytoseiid predatory mite employed for the biological control of agricultural pests including spider mites. Despite appearances, these predator and prey mites are separated by some 400 Myr of evolution and radically different lifestyles. We present a 152-Mb draft assembly of the M. occidentalis genome: Larger than that of its favored prey, Tetranychus urticae, but considerably smaller than those of many other chelicerates, enabling an extremely contiguous and complete assembly to be built-the best arachnid to date. Aided by transcriptome data, genome annotation cataloged 18,338 protein-coding genes and identified large numbers of Helitron transposable elements. Comparisons with other arthropods revealed a particularly dynamic and turbulent genomic evolutionary history. Its genes exhibit elevated molecular evolution, with strikingly high numbers of intron gains and losses, in stark contrast to the deer tick Ixodes scapularis Uniquely among examined arthropods, this predatory mite's Hox genes are completely atomized, dispersed across the genome, and it encodes five copies of the normally single-copy RNA processing Dicer-2 gene. Examining gene families linked to characteristic biological traits of this tiny predator provides initial insights into processes of sex determination, development, immune defense, and how it detects, disables, and digests its prey. As the first reference genome for the Phytoseiidae, and for any species with the rare sex determination system of parahaploidy, the genome of the western orchard predatory mite improves genomic sampling of chelicerates and provides invaluable new resources for functional genomic analyses of this family of agriculturally important mites. PMID:26951779

  13. A Carboniferous Mite on an Insect Reveals the Antiquity of an Inconspicuous Interaction.

    PubMed

    Robin, Ninon; Béthoux, Olivier; Sidorchuk, Ekaterina; Cui, Yingying; Li, Yingnan; Germain, Damien; King, Andrew; Berenguer, Felisa; Ren, Dong

    2016-05-23

    Symbiosis [1], understood as prolonged interspecific association, is as ancient as the eukaryotic cell [2, 3]. A variety of such associations have been reported in the continental fossil record, albeit sporadically. As for mites, which as a group have been present since the Devonian (ca. 390 mya) [4, 5] and are involved in a tremendous variety of modern-day symbioses, reported associations are limited to a few amber-preserved cases [6-11], with the earliest instance in the Cretaceous (ca. 85 mya) [11]. As a consequence, the antiquity and origin of associations involving small-sized mites and larger animals are poorly understood. Here we report, recovered from the Carboniferous Xiaheyan locality (ca. 320 mya), an oribatid mite located on the thorax of an extinct relative of grasshoppers, crickets, and katydids [12]. The mite was investigated using several methods, including phase-contrast tomography. The detailed morphological data allowed the placement of the mite in a new family within Mixonomata, whose fossil record is thus extended by ca. 250 Ma. Specimen and abundance distribution data derived from the fossil insect sample indicate that specimens from the corresponding excavation site were buried rapidly and were sub-autochthonous, indicating a syn vivo association. Moreover, the mite is located in a sequestered position on the insect. The observed interaction best fits the definition for phoresy, in which the benefit is transport and protection for the mite. This discovery demonstrates that this association, a trait shared by representatives of the most speciose mite taxa, arose very early during mite evolution. PMID:27161503

  14. Effect of freezing, hot tumble drying and washing with eucalyptus oil on house dust mites in soft toys.

    PubMed

    Chang, Chin-Fu; Wu, Francis Fu-Sheng; Chen, Chi-Ying; Crane, Julian; Siebers, Rob

    2011-09-01

    Soft toys are a major source of house dust mites (HDM) and HDM allergens, and sleeping with soft toys is a significant risk factor for HDM sensitization. We studied three techniques to eliminate HDM from soft toys, namely freezing, hot tumble drying and washing with eucalyptus oil. Thirty-six toys (12 in each treatment group) were enumerated for live HDM by the heat escape method before and after freezing overnight, hot tumble drying for 1 h and washing in 0.2% to 0.4% eucalyptus oil. Freezing, hot tumble drying and washing with eucalyptus oil resulted in significant reductions in live HDM, an average reduction of 95.1%, 89.1% and 95.1%, respectively. Additionally, washing with eucalyptus oil resulted in a significant reduction in HDM allergens as well from a geometric mean of 9.12 μg/g to 0.37 μg/g (p = 0.033). These three HDM elimination techniques give parents of infants effective and acceptable methods of limiting HDM exposure.

  15. House-dust mite allergen and ozone exposure decreases histamine H3 receptors in the brainstem respiratory nuclei

    SciTech Connect

    Sekizawa, Shin-ichi; Bechtold, Andrea G.; Tham, Rick C.; Kott, Kayleen S.; Hyde, Dallas M.; Joad, Jesse P.; Bonham, Ann C.

    2010-09-15

    Allergic airway diseases in children are a common and a growing health problem. Changes in the central nervous system (CNS) have been implicated in contributing to some of the symptoms. We hypothesized that airway allergic diseases are associated with altered histamine H3 receptor expression in the nucleus tractus solitarius (NTS) and caudal spinal trigeminal nucleus, where lung/airway and nasal sensory afferents terminate, respectively. Immunohistochemistry for histamine H3 receptors was performed on brainstem sections containing the NTS and the caudal spinal trigeminal nucleus from 6- and 12-month-old rhesus monkeys who had been exposed for 5 months to house dust mite allergen (HDMA) + O{sub 3} or to filtered air (FA). While histamine H3 receptors were found exclusively in astrocytes in the caudal spinal trigeminal nucleus, they were localized to both neuronal terminals and processes in the NTS. HDMA + O{sub 3} exposure significantly decreased histamine H3 receptor immunoreactivity in the NTS at 6 months and in the caudal spinal trigeminal nucleus at 12 months of age. In conclusion, exposing young primates to HDMA + O{sub 3} changed histamine H3 receptor expression in CNS pathways involving lung and nasal afferent nerves in an age-related manner. Histamine H3 receptors may be a therapeutic target for allergic asthma and rhinitis in children.

  16. Human immune response to allergens of house dust mite, Dermatophagoides pteronyssinus. IV. Occurrence of natural autologous anti-idiotypic antibodies.

    PubMed

    Saint-Remy, J M; Lebecque, S J; Lebrun, P M; Jacquemin, M G

    1988-01-01

    IgG isolated from the plasma of seven individuals hypersensitive to the common house dust mite Dermatophagoides pteronyssinus (DPT) was exhaustively adsorbed onto insolubilized DPT. The unbound fraction was found by radioimmunoassay to contain antibodies recognizing the variable region of both anti-DPT IgG and IgE antibodies. This recognition was idiotype (Id)-specific as it persisted after passage over insolubilized polyclonal IgG of unrelated specificity. Most of these anti-Id IgG carried the internal image of the initial antigen in that they competitively inhibited the binding of anti-DPT antibodies to DPT. Immunoadsorption of anti-Id IgG onto insolubilized anti-DPT IgG antibodies from the same individual completely eliminated their reaction with anti-DPT IgG but not with anti-DPT IgE, suggesting that idiotopes included in the antigen-binding site of specific IgG and IgE antibodies were not identical. Anti-Id IgG recognizing idiotopes located outside the antigen-binding site (bystander idiotopes) were also completely removed by passage over insolubilized anti-DPT IgG; in this case the reaction of the anti-Id IgG with both anti-DPT IgG and anti-DPT IgE was inhibited, indicating that, for a given individual, bystander idiotopes were shared between anti-DPT antibodies pertaining to these two isotypes.

  17. Generation of a chimeric dust mite hypoallergen using DNA shuffling for application in allergen-specific immunotherapy

    PubMed Central

    Zhao, Bei-Bei; Diao, Ji-Dong; Liu, Zhi-Ming; Li, Chao-Pin; Jiang, Yu-Xin

    2014-01-01

    Specific immunotherapy (SIT) is the only treatment that provides long lasting relief of allergy symptoms. Unfortunately, SIT-based traditional remedies carry the risk of producing local and/or systemic side effects. To improve the safety and efficacy of SIT, it has been proposed that SIT must utilize allergens that are hypoallergenic but hyperimmunogenic. Therefore, we used DNA shuffling to generate mutant genes encoding hypoallergens with potent immunogenicity and screened them for their capacity to modify the allergic response. We tentatively shuffled the major group 1 allergen genes from house dust mite, Dermatophagoides farinae and Dermatophagoides pteronyssinus, and discovered a novel chimeric gene, termed C 1. The gene was expressed in Escherichia coli (E. coli) and the chimeric protein C 1 was purified. An animal model of asthma demonstrated that C 1 not only decreased the production of serum IgE and IgG1, and inhibited the production of IL-4 and IL-5 in the bronchoalveolar lavage fluid (BALF). C 1 also boosted the levels of IgG2a and IFN-γ, which may demonstrate a rebalance of TH1 and TH2 allergic response. Additionally, flow cytometry showed that the immunogenicity of C 1 was higher than that of ProDer f 1, but was not significantly different from that of ProDer p 1. Our findings suggest that the C 1 is hypoallergenic and yet highly immunogenic, which makes it potentially safe and effective for use in SIT of allergic asthma. PMID:25120738

  18. Generation of a chimeric dust mite hypoallergen using DNA shuffling for application in allergen-specific immunotherapy.

    PubMed

    Zhao, Bei-Bei; Diao, Ji-Dong; Liu, Zhi-Ming; Li, Chao-Pin; Jiang, Yu-Xin

    2014-01-01

    Specific immunotherapy (SIT) is the only treatment that provides long lasting relief of allergy symptoms. Unfortunately, SIT-based traditional remedies carry the risk of producing local and/or systemic side effects. To improve the safety and efficacy of SIT, it has been proposed that SIT must utilize allergens that are hypoallergenic but hyperimmunogenic. Therefore, we used DNA shuffling to generate mutant genes encoding hypoallergens with potent immunogenicity and screened them for their capacity to modify the allergic response. We tentatively shuffled the major group 1 allergen genes from house dust mite, Dermatophagoides farinae and Dermatophagoides pteronyssinus, and discovered a novel chimeric gene, termed C 1. The gene was expressed in Escherichia coli (E. coli) and the chimeric protein C 1 was purified. An animal model of asthma demonstrated that C 1 not only decreased the production of serum IgE and IgG1, and inhibited the production of IL-4 and IL-5 in the bronchoalveolar lavage fluid (BALF). C 1 also boosted the levels of IgG2a and IFN-γ, which may demonstrate a rebalance of TH1 and TH2 allergic response. Additionally, flow cytometry showed that the immunogenicity of C 1 was higher than that of ProDer f 1, but was not significantly different from that of ProDer p 1. Our findings suggest that the C 1 is hypoallergenic and yet highly immunogenic, which makes it potentially safe and effective for use in SIT of allergic asthma. PMID:25120738

  19. Nanoparticle conjugation enhances the immunomodulatory effects of intranasally delivered CpG in house dust mite-allergic mice

    DOE PAGESBeta

    Ballester, Marie; Jeanbart, Laura; de Titta, Alexandre; Nembrini, Chiara; Marsland, Benjamin J.; Hubbell, Jeffrey A.; Swartz, Melody A.

    2015-09-21

    An emerging strategy in preventing and treating airway allergy consists of modulating the immune response induced against allergens in the lungs. CpG oligodeoxynucleotides have been investigated in airway allergy studies, but even if promising, efficacy requires further substantiation. We investigated the effect of pulmonary delivery of nanoparticle (NP)-conjugated CpG on lung immunity and found that NP-CpG led to enhanced recruitment of activated dendritic cells and to Th1 immunity compared to free CpG. We then evaluated if pulmonary delivery of NP-CpG could prevent and treat house dust mite-induced allergy by modulating immunity directly in lungs. When CpG was administered as immunomodulatorymore » therapy prior to allergen sensitization, we found that NP-CpG significantly reduced eosinophilia, IgE levels, mucus production and Th2 cytokines, while free CpG had only a moderate effect on these parameters. In a therapeutic setting where CpG was administered after allergen sensitization, we found that although both free CpG and NP-CpG reduced eosinophilia and IgE levels to the same extent, NP conjugation of CpG significantly enhanced reduction of Th2 cytokines in lungs of allergic mice. Taken together, these data highlight benefits of NP conjugation and the relevance of NP-CpG as allergen-free therapy to modulate lung immunity and treat airway allergy.« less

  20. Nanoparticle conjugation enhances the immunomodulatory effects of intranasally delivered CpG in house dust mite-allergic mice

    SciTech Connect

    Ballester, Marie; Jeanbart, Laura; de Titta, Alexandre; Nembrini, Chiara; Marsland, Benjamin J.; Hubbell, Jeffrey A.; Swartz, Melody A.

    2015-09-21

    An emerging strategy in preventing and treating airway allergy consists of modulating the immune response induced against allergens in the lungs. CpG oligodeoxynucleotides have been investigated in airway allergy studies, but even if promising, efficacy requires further substantiation. We investigated the effect of pulmonary delivery of nanoparticle (NP)-conjugated CpG on lung immunity and found that NP-CpG led to enhanced recruitment of activated dendritic cells and to Th1 immunity compared to free CpG. We then evaluated if pulmonary delivery of NP-CpG could prevent and treat house dust mite-induced allergy by modulating immunity directly in lungs. When CpG was administered as immunomodulatory therapy prior to allergen sensitization, we found that NP-CpG significantly reduced eosinophilia, IgE levels, mucus production and Th2 cytokines, while free CpG had only a moderate effect on these parameters. In a therapeutic setting where CpG was administered after allergen sensitization, we found that although both free CpG and NP-CpG reduced eosinophilia and IgE levels to the same extent, NP conjugation of CpG significantly enhanced reduction of Th2 cytokines in lungs of allergic mice. Taken together, these data highlight benefits of NP conjugation and the relevance of NP-CpG as allergen-free therapy to modulate lung immunity and treat airway allergy.

  1. Sulphido-leukotriene production from peripheral leukocytes and skin in clinically normal dogs and house dust mite positive atopic dogs.

    PubMed

    Marsella, R; Nicklin, C F

    2001-02-01

    Pathogenesis of canine atopy has not been completely elucidated. In humans, sulphido-leukotrienes (s-LT) play a role in atopy, and increased production of s-LT occurs in the skin and peripheral leukocytes after allergen challenge. The study population included 16 clinically normal and 13 atopic dogs. All atopic dogs had in common a positive reaction (4+) to the intradermal injection of house dust mite (allergen of reference). Blood samples and skin biopsies were collected. Sulphido-LT synthesis by peripheral leukocytes after stimulation was measured, and no statistically significant difference was found between clinically normal and atopic dogs. Sulphido-LT concentrations in skin samples from stimulated and unstimulated sites were measured, and no statistically significant difference was detected between clinically normal and atopic dogs or between lesional and nonlesional skin within the atopic group. Clinical signs of atopic dogs were graded by owners and no correlation was found between their severity and cutaneous concentrations of s-LT. In this study there was no increase in s-LT synthesis in atopic dogs.

  2. Nanoparticle conjugation enhances the immunomodulatory effects of intranasally delivered CpG in house dust mite-allergic mice

    PubMed Central

    Ballester, Marie; Jeanbart, Laura; de Titta, Alexandre; Nembrini, Chiara; Marsland, Benjamin J.; Hubbell, Jeffrey A.; Swartz, Melody A.

    2015-01-01

    An emerging strategy in preventing and treating airway allergy consists of modulating the immune response induced against allergens in the lungs. CpG oligodeoxynucleotides have been investigated in airway allergy studies, but even if promising, efficacy requires further substantiation. We investigated the effect of pulmonary delivery of nanoparticle (NP)-conjugated CpG on lung immunity and found that NP-CpG led to enhanced recruitment of activated dendritic cells and to Th1 immunity compared to free CpG. We then evaluated if pulmonary delivery of NP-CpG could prevent and treat house dust mite-induced allergy by modulating immunity directly in lungs. When CpG was administered as immunomodulatory therapy prior to allergen sensitization, we found that NP-CpG significantly reduced eosinophilia, IgE levels, mucus production and Th2 cytokines, while free CpG had only a moderate effect on these parameters. In a therapeutic setting where CpG was administered after allergen sensitization, we found that although both free CpG and NP-CpG reduced eosinophilia and IgE levels to the same extent, NP conjugation of CpG significantly enhanced reduction of Th2 cytokines in lungs of allergic mice. Taken together, these data highlight benefits of NP conjugation and the relevance of NP-CpG as allergen-free therapy to modulate lung immunity and treat airway allergy. PMID:26387548

  3. Tropomyosin or not tropomyosin, what is the relevant allergen in house dust mite and snail cross allergies?

    PubMed

    Bessot, J C; Metz-Favre, C; Rame, J M; De Blay, F; Pauli, G

    2010-02-01

    Since tropomyosin is cross reactive in many arthropods, it was assumed that this highly conserved protein could be responsible for cross reactions in house dust mite (HDM) allergic patients who experienced adverse reactions after crustacean and mollusc ingestion. Here we report two clinical cases where the role of tropomyosin is a matter of debate. In the first case, the clinical history, as well as the results of in vivo and in vitro investigations, are in favour of a shrimp allergy without any snail allergy in a patient sensitized to HDM. In the second, the clinical history and the cutaneous tests are in favour of an allergy to snails without any allergy to shrimps in a patient suffering from HDM allergies. The clinical presentation is different in shrimp and snail allergies. In shrimp allergy, symptoms are mainly urticaria or angio-oedema. In snail allergies, adverse reactions are especially severe asthma. Shrimp tropomyosin is a dominant allergen in crustaceans whereas has a much less prominent role in HDM sensitization. Cross reactivities between HDM and snails have been confirmed by inhibition experiments. However, tropomyosin appears to be a minor allergen or even is not involved in snail allergy. It is necessary to clarify the allergens shared between HDMI and snails. The effects of HDM immunotherapy in snail allergy are questioned. Knowledge of taxonomy can contribute to more precise evaluation of cross reactivities between crustaceans and molluscs.

  4. Comparative proteomic analysis reveals mite (Varroa destructor) resistance-related proteins in Eastern honeybees (Apis cerana).

    PubMed

    Ji, T; Shen, F; Liu, Z; Yin, L; Shen, J; Liang, Q; Luo, Y X

    2015-08-21

    The mite (Varroa destructor) has become the greatest threat to apiculture worldwide. As the original host of the mite, Apis cerana can effectively resist the mite. An increased understanding of the resistance mechanisms of Eastern honeybees against V. destructor may help researchers to protect other species against these parasites. In this study, the proteomes of 4 Apis cerana colonies were analyzed using an isobaric tag for relative and absolute quantitation technology. We determined the differences in gene and protein expression between susceptible and resistant colonies that were either unchallenged or challenged by V. destructor. The results showed that a total of 1532 proteins were identified. Gene Ontology enrichment analysis suggested that the transcription factors and basic metabolic and respiratory processes were efficient and feasible factors controlling this resistance, and 12 differentially expressed proteins were identified in Venn analysis. The results were validated by quantitative polymerase chain reaction. This study may provide insight into the genetic mechanisms underlying the resistance of honeybee to mites.

  5. Serum antibody to Sarcoptes scabiei and house dust mite prior to and during infestation with S. scabiei.

    PubMed

    Arlian, L G; Morgan, M S

    2000-07-01

    In this study, serum antibodies to Sarcoptes scabiei var. canis (SS), Dermatophagoides farinae (DF), and D. pteronyssinus (DP) were determined in 19 healthy, random-source dogs prior to infestation with scabies then again during a primary infestation, cure and challenge infestation with scabies. Prior to scabies infestation, serum of 11 dogs contained faintly detectable amounts of IgE and/or IgG to proteins in SS extract, probably resulting from sensitization to dust mites that share cross-reactive antigenic epitopes with SS. After becoming infested with scabies, the response to SS antigens became stronger with antibodies appearing to more antigens as the scabies infestation progressed. Three of the newly recognized proteins were 170, 155 and 142/133kD and could be used in a diagnostic test since antibodies to them appeared during the primary infestation. In addition, during the primary infestation, 14 of 15 dogs developed IgE to 1-11 new SS proteins in addition to an increase in IgE binding to those proteins recognized prior to infestation. Overall, the strongest antibody responses (IgE and IgG) were exhibited during cure of the first infestation, when dead mites were still present in the stratum corneum. As expected, the antibody response was strong and rapid during challenge when the infestation self-cured. The immunogenic SS proteins identified by serum antibody binding during challenge, when the hosts self-cured, are candidates for inclusion in a vaccine. These candidate proteins are 200, 185, 170, 155, 142/133, 112, 97, 74, 57, 45/42, 32 and 22kD. Some of the proteins in SS that exhibited new or increased antibody binding during the experiment also had IgE and IgG binding to proteins with similar molecular weights in DF and DP extracts. These results illustrate the difficulties involved in understanding and interpreting serum antibody for developing a serological test for the diagnosis of scabies, isolating relevant SS antigens that could be included in a

  6. The complete mitochondrial genome of the house dust mite Dermatophagoides pteronyssinus (Trouessart): a novel gene arrangement among arthropods

    PubMed Central

    Dermauw, Wannes; Van Leeuwen, Thomas; Vanholme, Bartel; Tirry, Luc

    2009-01-01

    Background The apparent scarcity of available sequence data has greatly impeded evolutionary studies in Acari (mites and ticks). This subclass encompasses over 48,000 species and forms the largest group within the Arachnida. Although mitochondrial genomes are widely utilised for phylogenetic and population genetic studies, only 20 mitochondrial genomes of Acari have been determined, of which only one belongs to the diverse order of the Sarcoptiformes. In this study, we describe the mitochondrial genome of the European house dust mite Dermatophagoides pteronyssinus, the most important member of this largely neglected group. Results The mitochondrial genome of D. pteronyssinus is a circular DNA molecule of 14,203 bp. It contains the complete set of 37 genes (13 protein coding genes, 2 rRNA genes and 22 tRNA genes), usually present in metazoan mitochondrial genomes. The mitochondrial gene order differs considerably from that of other Acari mitochondrial genomes. Compared to the mitochondrial genome of Limulus polyphemus, considered as the ancestral arthropod pattern, only 11 of the 38 gene boundaries are conserved. The majority strand has a 72.6% AT-content but a GC-skew of 0.194. This skew is the reverse of that normally observed for typical animal mitochondrial genomes. A microsatellite was detected in a large non-coding region (286 bp), which probably functions as the control region. Almost all tRNA genes lack a T-arm, provoking the formation of canonical cloverleaf tRNA-structures, and both rRNA genes are considerably reduced in size. Finally, the genomic sequence was used to perform a phylogenetic study. Both maximum likelihood and Bayesian inference analysis clustered D. pteronyssinus with Steganacarus magnus, forming a sistergroup of the Trombidiformes. Conclusion Although the mitochondrial genome of D. pteronyssinus shares different features with previously characterised Acari mitochondrial genomes, it is unique in many ways. Gene order is extremely rearranged

  7. NICMOS PEERS THROUGH DUST TO REVEAL YOUNG STELLAR DISKS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The following images were taken by NASA Hubble Space Telescope's Near-Infrared Camera and Multi-Object Spectrometer (NICMOS). All of the objects are extremely young stars, 450 light-years away in the constellation Taurus. Most of the nebulae represent small dust particles around the stars, which are seen because they are reflecting starlight. In the color-coding, regions of greatest dust concentration appear red. All photo credits: D. Padgett (IPAC/Caltech), W. Brandner (IPAC), K. Stapelfeldt (JPL) and NASA [Top left]: CoKu Tau/1. This image shows a newborn binary star system, CoKu Tau/1, lying at the center of four 'wings' of light extending as much as 75 billion miles from the pair. The 'wings' outline the edges of a region in the stars' dusty surroundings, which have been cleared by outflowing gas. A thin, dark lane extends to the left and to right of the binary, suggesting that a disk or ring of dusty material encircles the two young stars. [Top center]: DG Tau B - An excellent example of the complementary nature of Hubble's instruments may be found by comparing the infrared NICMOS image of DG Tau B to the visible-light Wide Field and Planetary Camera 2 (WFPC2) image of the same object. WFPC2 highlights the jet emerging from the system, while NICMOS penetrates some of the dust near the star to more clearly outline the 50 billion-mile-long dust lane (the horizontal dark band, which indicates the presence of a large disk forming around the infant star). The young star itself appears as the bright red spot at the corner of the V-shaped nebula. [Top right]: Haro 6-5B - This image of the young star Haro 6-5B shows two bright regions separated by a dark lane. As seen in the WFPC2 image of the same object, the bright regions represent starlight reflecting from the upper and lower surfaces of the disk, which is thicker at its edges than its center. However, the infrared view reveals the young star just above the dust lane. [Bottom left]: I04016 - A very young star

  8. Genome Sequencing of the Phytoseiid Predatory Mite Metaseiulus occidentalis Reveals Completely Atomized Hox Genes and Superdynamic Intron Evolution

    PubMed Central

    Hoy, Marjorie A.; Waterhouse, Robert M.; Wu, Ke; Estep, Alden S.; Ioannidis, Panagiotis; Palmer, William J.; Pomerantz, Aaron F.; Simão, Felipe A.; Thomas, Jainy; Jiggins, Francis M.; Murphy, Terence D.; Pritham, Ellen J.; Robertson, Hugh M.; Zdobnov, Evgeny M.; Gibbs, Richard A.; Richards, Stephen

    2016-01-01

    Metaseiulus occidentalis is an eyeless phytoseiid predatory mite employed for the biological control of agricultural pests including spider mites. Despite appearances, these predator and prey mites are separated by some 400 Myr of evolution and radically different lifestyles. We present a 152-Mb draft assembly of the M. occidentalis genome: Larger than that of its favored prey, Tetranychus urticae, but considerably smaller than those of many other chelicerates, enabling an extremely contiguous and complete assembly to be built—the best arachnid to date. Aided by transcriptome data, genome annotation cataloged 18,338 protein-coding genes and identified large numbers of Helitron transposable elements. Comparisons with other arthropods revealed a particularly dynamic and turbulent genomic evolutionary history. Its genes exhibit elevated molecular evolution, with strikingly high numbers of intron gains and losses, in stark contrast to the deer tick Ixodes scapularis. Uniquely among examined arthropods, this predatory mite’s Hox genes are completely atomized, dispersed across the genome, and it encodes five copies of the normally single-copy RNA processing Dicer-2 gene. Examining gene families linked to characteristic biological traits of this tiny predator provides initial insights into processes of sex determination, development, immune defense, and how it detects, disables, and digests its prey. As the first reference genome for the Phytoseiidae, and for any species with the rare sex determination system of parahaploidy, the genome of the western orchard predatory mite improves genomic sampling of chelicerates and provides invaluable new resources for functional genomic analyses of this family of agriculturally important mites. PMID:26951779

  9. Class specific inhibition of house dust mite proteinases which cleave cell adhesion, induce cell death and which increase the permeability of lung epithelium

    PubMed Central

    Winton, Helen L; Wan, Hong; Cannell, Mark B; Thompson, Philip J; Garrod, David R; Stewart, Geoffrey A; Robinson, Clive

    1998-01-01

    House dust mite (HDM) allergens with cysteine and serine proteinase activity are risk factors for allergic sensitization and asthma. A simple method to fractionate proteinase activity from HDM faecal pellets into cysteine and serine class activity is described. Both proteinase fractions increased the permeability of epithelial cell monolayers. The effects of the serine proteinase fraction were inhibited by 4-(2-aminoethyl)-benzenesulphonyl fluoride hydrochloride (AEBSF) and soybean trypsin inhibitor (SBTI). The effects of the cysteine proteinase fraction could be inhibited by E-64. No reciprocity of action was found. Treatment of epithelial monolayers with either proteinase fraction caused breakdown of tight junctions (TJs). AEBSF inhibited TJ breakdown caused by the serine proteinase fraction, whereas E-64 inhibited the cysteine proteinase fraction. Agarose gel electrophoresis revealed that the proteinases induced DNA cleavage which was inhibited by the matrix metalloproteinase inhibitor BB-250. Compound E-64 inhibited DNA fragmentation caused by the cysteine proteinase fraction, but was without effect on the serine proteinase fraction. Staining of proteinase-treated cells with annexin V (AV) and propidium iodide (PI) revealed a diversity of cellular responses. Some cells stained only with AV indicating early apoptosis, whilst others were dead and stained with both AV and PI. HDM proteinases exert profound effects on epithelial cells which will promote allergic sensitization; namely disruption of intercellular adhesion, increased paracellular permeability and initiation of cell death. Attenuation of these actions by proteinase inhibitors leads to the conclusion that compounds designed to be selective for the HDM enzymes may represent a novel therapy for asthma. PMID:9720772

  10. Dust mite, cockroach, cat, and dog allergen concentrations in homes of asthmatic children in the northeastern United States: impact of socioeconomic factors and population density.

    PubMed Central

    Leaderer, Brian P; Belanger, Kathleen; Triche, Elizabeth; Holford, Theodore; Gold, Diane R; Kim, Young; Jankun, Thomas; Ren, Ping; McSharry Je, Jean-ellen; Platts-Mills, Thomas A E; Chapman, Martin D; Bracken, Michael B

    2002-01-01

    Home exposures to aeroallergens are an important environmental factor in allergic sensitization and in the development and exacerbation of asthma. We assessed variations in home concentrations of dust mite, cockroach, cat, and dog allergens in dust collected in the main living areas of asthmatics' homes by family income, mother's education, dwelling type, population density, household population density, and ethnicity in Connecticut and south-central Massachusetts. Dust samples were collected at the time of home interview in 999 homes as part of an ongoing longitudinal birth cohort study of 1,002 infants and their asthmatic siblings. The analysis employed lower and upper cut points for group 1 dust mite (> or = 2.0 microg/g and > or = 10 microg/g), cockroach (> or = 1.0 U/g and > or = 4.0 U/g), cat (> or = 1.0 microg/g and > or = 8.0 ug/g), and dog (> or = 2.0 microg/g and > or = 10.0 microg/g) allergens. Subject residences were geocoded to assess population density from the U.S. Census, and multiple logistic regression was used to control for confounding. The portion of homes at the lower cut point for dust mite, cockroach, cat, and dog allergens were 46.9%, 24.9%, 42.2%, and 35.6%, respectively; the upper cut point for each of the allergens was reached in 22.4%, 13.4%, 21.0%, and 22.9% of the homes, respectively. In all, 86.0% of the homes had at least one allergen at the lower cut point, and 58.0% had at least one allergen at the upper cut point. Forty-nine percent of the homes had two or more allergens at the lower cut point, and 19.7% had two or more allergens at the upper cut point. Higher education of the mother, higher household income, living in a single-family home in a less densely populated area with fewer people per room, and being a white household were associated with elevated dust mite, cat, and dog allergens and low cockroach allergen. In contrast, low income, living in a multifamily home in a high population density area with a higher occupancy

  11. Evaluation of HEPA vacuum cleaning and dry steam cleaning in reducing levels of polycyclic aromatic hydrocarbons and house dust mite allergens in carpets.

    PubMed

    Yu, Chang Ho; Yiin, Lih-Ming; Tina Fan, Zhi-Hua; Rhoads, George G

    2009-01-01

    Dry steam cleaning, which has gained recent attention as an effective method to reduce house dust mite (HDM) allergen concentration and loading in carpets, was evaluated in this study for its efficacy in lowering levels of polycyclic aromatic hydrocarbons (PAHs) as well as HDM allergens. Fifty urban homes with wall-to-wall carpets, mostly low-income and with known lead contamination, were studied in 2003 and 2004. Two carpet-cleaning interventions were compared: Repeated HEPA (High Efficiency Particulate Air filtered) vacuuming alone and repeated HEPA vacuuming supplemented with dry steam cleaning. Vacuum samples were collected to measure carpet loading of dust and contaminants immediately before and after cleaning. Paired comparisons were conducted to evaluate the effectiveness of the cleaning protocols in reducing the levels of PAHs and HDM allergens in carpets. The results indicated that both cleaning methods substantially reduced the loading of PAHs and HDM allergens as well as dust in carpets (p < 0.0001). The reductions in loading of dust (64.4%), PAHs (69.1%), and HDM allergens (85.5%), by dry steam cleaning plus repetitive HEPA vacuuming were larger than the reductions by regular HEPA vacuuming alone: dust (55.5%), PAHs (58.6%), and HDM allergens (80.8%), although the difference was statistically significant only for dust and PAHs. We conclude that intensive HEPA vacuum cleaning substantially reduced the loading of PAHs and HDM allergens in carpets in these urban homes and that dry steam cleaning added modestly to cleaning effectiveness. PMID:19137159

  12. Effect of the oral thrombin inhibitor dabigatran on allergic lung inflammation induced by repeated house dust mite administration in mice.

    PubMed

    de Boer, Johannes D; Berkhout, Lea C; de Stoppelaar, Sacha F; Yang, Jack; Ottenhoff, Roelof; Meijers, Joost C M; Roelofs, Joris J T H; van't Veer, Cornelis; van der Poll, Tom

    2015-10-15

    Asthma is a chronic disease of the airways; asthma patients are hampered by recurrent symptoms of dyspnoea and wheezing caused by bronchial obstruction. Most asthma patients suffer from chronic allergic lung inflammation triggered by allergens such as house dust mite (HDM). Coagulation activation in the pulmonary compartment is currently recognized as a feature of allergic lung inflammation, and data suggest that coagulation proteases further drive inflammatory mechanisms. Here, we tested whether treatment with the oral thrombin inhibitor dabigatran attenuates allergic lung inflammation in a recently developed HDM-based murine asthma model. Mice were fed dabigatran (10 mg/g) or placebo chow during a 3-wk HDM airway exposure model. Dabigatran treatment caused systemic thrombin inhibitory activity corresponding with dabigatran levels reported in human trials. Surprisingly, dabigatran did not lead to inhibition of HDM-evoked coagulation activation in the lung as measured by levels of thrombin-antithrombin complexes and D-dimer. Repeated HDM administration caused an influx of eosinophils and neutrophils into the lungs, mucus production in the airways, and a T helper 2 response, as reflected by a rise in bronchoalveolar IL-4 and IL-5 levels and a systemic rise in IgE and HDM-IgG1. Dabigatran modestly improved HDM-induced lung pathology (P < 0.05) and decreased IL-4 levels (P < 0.01), without influencing other HDM-induced responses. Considering the limited effects of dabigatran in spite of adequate plasma levels, these results argue against clinical evaluation of dabigatran in patients with asthma.

  13. Proteolytic Activity Present in House-Dust-Mite Extracts Degrades ENA-78/CXCL5 and Reduces Neutrophil Migration.

    PubMed

    Keglowich, Laura; Tamm, Michael; Zhong, Jun; Miglino, Nicola; Borger, Pieter

    2014-01-01

    Background. Bronchial smooth muscle cells (BSMC) are a major source of proinflammatory and proangiogenic cytokines and chemokines, including VEGF and CXC-chemokines. CXC-chemokines act primarily on neutrophils, mediating their recruitment to and activation at the site of inflammation. In humans, house-dust mite (HDM) allergens can cause asthmatic exacerbations and trigger an inflammatory response through protease-dependent mechanisms. Objective. We investigated the effect HDM extract on the release of pro-angiogenic and proinflammatory cytokines from BSMC. Methods. Human primary BSMC were stimulated with HDM extract in the absence or presence of fetal calf serum (FCS). Twenty angiogenic cytokines were detected by a specific antibody array and modified protein levels were confirmed by ELISA. Neutrophil migration was measured using a 96-well Boyden chamber. Results. ENA-78/CXCL5 protein levels in conditioned medium of BSMC stimulated with HDM extract were significantly reduced (n = 10, P < 0.05) but restored in the presence of 5% FCS. HDM extracts did not affect ENA-78/CXCL5 mRNA levels. Recombinant ENA-78/CXCL5 was degraded after incubation with HDM extracts (n = 7, P < 0.05) but restored after the addition of the serine protease AEBSF. Neutrophil migration towards recombinant ENA-78/CXCL5 was also reduced in the presence of HDM extract. Conclusion. HDM proteases degrade ENA-78/CXCL5. Thus exposure to HDM allergens may alter ENA-78/CXCL5 levels in the lungs and may affect angiogenesis and the inflammatory response in the airways of asthma patients.

  14. PARP is activated in human asthma and its inhibition by olaparib blocks house dust mite-induced disease in mice

    PubMed Central

    Ghonim, Mohamed A.; Pyakurel, Kusma; Ibba, Salome V.; Wang, Jeffrey; Rodriguez, Paulo; Al-Khami, Amir A.; Lammi, Matthew R.; Kim, Hogyoung; Zea, Arnold H.; Davis, Christian; Okpechi, Samuel; Wyczechowska, Dorota; Al-Ghareeb, Kamel; Mansy, Moselhy S.; Ochoa, Augusto; Naura, Amarjit S.

    2015-01-01

    Our laboratory established a role for poly(ADP-ribose)polymerase (PARP) in asthma. To increase the clinical significance of our studies, it is imperative to demonstrate that PARP is actually activated in human asthma, to examine whether a PARP inhibitor approved for human testing such as olaparib blocks already-established chronic asthma traits in response to house dust mite (HDM), a true human allergen, in mice and to examine whether the drug modulates human cluster of differentiation type 4 (CD4+) T-cell function. To conduct the study, human lung specimens and peripheral blood mononuclear cells (PBMCs) and a HDM-based mouse asthma model were used. Our results show that PARP is activated in PBMCs and lung tissues of asthmatics. PARP inhibition by olaparib or gene knockout blocked established asthma-like traits in mice chronically exposed to HDM including airway eosinophilia and hyper-responsiveness. These effects were linked to a marked reduction in T helper 2 (Th2) cytokine production without a prominent effect on interferon (IFN)-γ or interleukin (IL)-10. PARP inhibition prevented HDM-induced increase in overall cellularity, weight and CD4+ T-cell population in spleens of treated mice whereas it increased the T-regulatory cell population. In CD3/CD28-stimulated human CD4 +T-cells, olaparib treatment reduced Th2 cytokine production potentially by modulating GATA binding protein-3 (gata-3)/IL-4 expression while moderately affecting T-cell proliferation. PARP inhibition inconsistently increased IL-17 in HDM-exposed mice and CD3/CD28-stimulated CD4+ T cells without a concomitant increase in factors that can be influenced by IL-17. In the present study, we provide evidence for the first time that PARP-1 is activated in human asthma and that its inhibition is effective in blocking established asthma in mice. PMID:26205779

  15. Effect of the house dust mite allergen Der p 1 on tryptase release from human mast cells.

    PubMed

    Wang, D Q; Shen, Y Y; Xu, J H; Tang, H

    2016-07-14

    This study aimed to investigate the effects of the house dust mite allergen Der p 1 on the secretion of tryptase from the human mast cell line HMC-1. Flow cytometry was used to determine the expression levels of protease-activated receptor-2 (PAR2) on the surface of HMC-1 cells. HMC-1 cells were treated with Der p 1, SLIGRL-NH2 (PAR2 agonist), LRGILS-NH2 (control peptide for PAR2), or Der p 1 + FSLLRY (PAR2 antagonist), and the tryptase levels were measured using enzyme-linked immunosorbent assay. The biological functions of PAR2 were determined using the calcium green indicator, and intracellular calcium fluorescence intensity in the different groups (Der p 1, SLIGRL-NH2, LRGILS- NH2, Der p 1 + FSLLRY, tryptase, tryptase + FSLLRY, or cell culture medium) was detected by laser scanning confocal microscopy. The mast cells expressed PAR2 receptor on their surfaces. Der p 1 alone induced a significant release of intracellular calcium and tryptase in HMC-1 cells compared with the SLIGRL- NH2 treatment group and the control group. The combination of Der p 1 and FSLLRY partly inhibited intracellular calcium and tryptase release in HMC-1 cells compared with the Der p 1 treatment group. Moreover, tryptase induced a significant release of intracellular calcium in the HMC-1 cells. Der p 1 induced HMC-1 cell degranulation and the release of tryptase by activating the PAR2 receptor on the cell surfaces. Tryptase activated the PAR2 receptor and induced intracellular calcium release from the HMC-1 cells in a positive feedback loop.

  16. Effect of the house dust mite allergen Der p 1 on tryptase release from human mast cells.

    PubMed

    Wang, D Q; Shen, Y Y; Xu, J H; Tang, H

    2016-01-01

    This study aimed to investigate the effects of the house dust mite allergen Der p 1 on the secretion of tryptase from the human mast cell line HMC-1. Flow cytometry was used to determine the expression levels of protease-activated receptor-2 (PAR2) on the surface of HMC-1 cells. HMC-1 cells were treated with Der p 1, SLIGRL-NH2 (PAR2 agonist), LRGILS-NH2 (control peptide for PAR2), or Der p 1 + FSLLRY (PAR2 antagonist), and the tryptase levels were measured using enzyme-linked immunosorbent assay. The biological functions of PAR2 were determined using the calcium green indicator, and intracellular calcium fluorescence intensity in the different groups (Der p 1, SLIGRL-NH2, LRGILS- NH2, Der p 1 + FSLLRY, tryptase, tryptase + FSLLRY, or cell culture medium) was detected by laser scanning confocal microscopy. The mast cells expressed PAR2 receptor on their surfaces. Der p 1 alone induced a significant release of intracellular calcium and tryptase in HMC-1 cells compared with the SLIGRL- NH2 treatment group and the control group. The combination of Der p 1 and FSLLRY partly inhibited intracellular calcium and tryptase release in HMC-1 cells compared with the Der p 1 treatment group. Moreover, tryptase induced a significant release of intracellular calcium in the HMC-1 cells. Der p 1 induced HMC-1 cell degranulation and the release of tryptase by activating the PAR2 receptor on the cell surfaces. Tryptase activated the PAR2 receptor and induced intracellular calcium release from the HMC-1 cells in a positive feedback loop. PMID:27421012

  17. Immunomodulation of airway epithelium cell activation by mesenchymal stromal cells ameliorates house dust mite-induced airway inflammation in mice.

    PubMed

    Duong, Khang M; Arikkatt, Jaisy; Ullah, M Ashik; Lynch, Jason P; Zhang, Vivian; Atkinson, Kerry; Sly, Peter D; Phipps, Simon

    2015-11-01

    Allergic asthma is underpinned by T helper 2 (Th2) inflammation. Redundancy in Th2 cytokine function and production by innate and adaptive immune cells suggests that strategies aimed at immunomodulation may prove more beneficial. Hence, we sought to determine whether administration of mesenchymal stromal cells (MSCs) to house dust mite (HDM) (Dermatophagoides pteronyssinus)-sensitized mice would suppress the development of Th2 inflammation and airway hyperresponsiveness (AHR) after HDM challenge. We report that the intravenous administration of allogeneic donor MSCs 1 hour before allergen challenge significantly attenuated the features of allergic asthma, including tissue eosinophilia, Th2 cytokine (IL-5 and IL-13) levels in bronchoalveolar lavage fluid, and AHR. The number of infiltrating type 2 innate lymphoid cells was not affected by MSC transfer, suggesting that MSCs may modulate the adaptive arm of Th2 immunity. The effect of MSC administration was long lasting; all features of allergic airway disease were significantly suppressed in response to a second round of HDM challenge 4 weeks after MSC administration. Further, we observed that MSCs decreased the release of epithelial cell-derived alarmins IL-1α and high mobility group box-1 in an IL-1 receptor antagonist-dependent manner. This significantly decreased the expression of the pro-Th2 cytokine IL-25 and reduced the number of activated and antigen-acquiring CD11c(+)CD11b(+) dendritic cells in the lung and mediastinal lymph nodes. Our findings suggest that MSC administration can ameliorate allergic airway inflammation by blunting the amplification of epithelial-derived inflammatory cytokines induced by HDM exposure and may offer long-term protection against Th2-mediated allergic airway inflammation and AHR.

  18. Evaporative Cooler Use Influences Temporal Indoor Relative Humidity but Not Dust Mite Allergen Levels in Homes in a Semi-Arid Climate.

    PubMed

    Johnston, James D; Tuttle, Steven C; Nelson, Morgan C; Bradshaw, Rebecca K; Hoybjerg, Taylor G; Johnson, Julene B; Kruman, Bryce A; Orton, Taylor S; Cook, Ryan B; Eggett, Dennis L; Weber, K Scott

    2016-01-01

    Concerns about energy consumption and climate change make residential evaporative coolers a popular alternative to central air conditioning in arid and semi-arid climates. However, evaporative coolers have been shown to significantly increase indoor relative humidity and dust mite allergen levels in some studies, while showing no association in other studies. Improved measurement of temporal fluctuations in indoor relative humidity may help identify factors that promote mite growth in homes in dry climates. Dust samples and continuous indoor relative humidity measurements were collected from homes with central air conditioning and homes with evaporative coolers in Utah. Samples were collected over two seasons, winter/spring (Jan-Apr) and summer (July-Sept), 2014. Dust samples were analyzed for Der p 1 and Der f 1 using a two-site monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) analysis. Housing characteristics including age of home, occupant density, and age of mattresses, furniture, and carpeting were also measured. Positive Der p 1 or Der f 1 samples were found in 25.0% of the homes and there was no difference in mean allergen levels by type of air conditioning. Indoor relative humidity was significantly higher in homes with evaporative coolers compared to those with central air conditioning during the summer. Homes with evaporative coolers also spent significantly more time during summer above 55.0% and 65.0% relative humidity compared to central air homes, but not above 75.0%. Findings from this study suggest that increased humidity from evaporative coolers may not be sufficient to exceed the critical equilibrium humidity or maintain humidity excursions for sufficient duration in relatively larger single-family homes in semi-arid climates to support mite growth and reproduction. PMID:26808528

  19. Measurement of serum immunoglobulin E (IgE) specific for house dust mite antigens in normal cats and cats with allergic skin disease.

    PubMed

    Taglinger, K; Helps, C R; Day, M J; Foster, A P

    2005-05-01

    The purpose of this study was to determine whether cats with allergic skin disease have significant concentrations of serum Immunoglobulin E (IgE) specific for antigens derived from the house dust mites (HDM) Dermatophagoides farinae (DF) and Dermatophagoides pteronyssinus (DP). Enzyme-linked immunosorbent assays (ELISA) were developed for this purpose. Binding of serum allergen-specific IgE was detected via the use of biotinylated Fc-epsilon receptor alpha chain protein (FcvarepsilonRIalpha). Following optimisation of the assay, serum samples from 59 cats with allergic skin disease and 54 clinically normal cats were screened. Results were expressed as ELISA units per ml (EU/ml) compared to a standard curve. Serological findings were correlated with the clinical presentation of affected cats. Cats with symptoms of feline allergic skin disease were grouped as follows: self-induced alopecia without lesions (group 1), papulocrusting dermatitis (group 2), eosinophilic granuloma complex (group 3), papular/ulcerative dermatitis of head and neck/facial dermatitis (group 4), and a combination of symptoms (group 5). Control normal cats comprised the final group (group 6). The Kruskal-Wallis test was used for statistical analysis. There was no significant difference between groups for DF- and DP-specific IgE concentrations with a p-value of 0.875 and 0.705, respectively. Although the FcvarepsilonRIalpha-based ELISA was able to detect house dust mite-specific feline IgE, the presence of this allergen-specific IgE correlates poorly with the presence of clinical manifestations of allergic skin disease. The results of this study question the clinical relevance of house dust mite-specific IgE in feline allergic skin disease.

  20. Evaporative Cooler Use Influences Temporal Indoor Relative Humidity but Not Dust Mite Allergen Levels in Homes in a Semi-Arid Climate.

    PubMed

    Johnston, James D; Tuttle, Steven C; Nelson, Morgan C; Bradshaw, Rebecca K; Hoybjerg, Taylor G; Johnson, Julene B; Kruman, Bryce A; Orton, Taylor S; Cook, Ryan B; Eggett, Dennis L; Weber, K Scott

    2016-01-01

    Concerns about energy consumption and climate change make residential evaporative coolers a popular alternative to central air conditioning in arid and semi-arid climates. However, evaporative coolers have been shown to significantly increase indoor relative humidity and dust mite allergen levels in some studies, while showing no association in other studies. Improved measurement of temporal fluctuations in indoor relative humidity may help identify factors that promote mite growth in homes in dry climates. Dust samples and continuous indoor relative humidity measurements were collected from homes with central air conditioning and homes with evaporative coolers in Utah. Samples were collected over two seasons, winter/spring (Jan-Apr) and summer (July-Sept), 2014. Dust samples were analyzed for Der p 1 and Der f 1 using a two-site monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) analysis. Housing characteristics including age of home, occupant density, and age of mattresses, furniture, and carpeting were also measured. Positive Der p 1 or Der f 1 samples were found in 25.0% of the homes and there was no difference in mean allergen levels by type of air conditioning. Indoor relative humidity was significantly higher in homes with evaporative coolers compared to those with central air conditioning during the summer. Homes with evaporative coolers also spent significantly more time during summer above 55.0% and 65.0% relative humidity compared to central air homes, but not above 75.0%. Findings from this study suggest that increased humidity from evaporative coolers may not be sufficient to exceed the critical equilibrium humidity or maintain humidity excursions for sufficient duration in relatively larger single-family homes in semi-arid climates to support mite growth and reproduction.

  1. Evaporative Cooler Use Influences Temporal Indoor Relative Humidity but Not Dust Mite Allergen Levels in Homes in a Semi-Arid Climate

    PubMed Central

    Johnston, James D.; Tuttle, Steven C.; Nelson, Morgan C.; Bradshaw, Rebecca K.; Hoybjerg, Taylor G.; Johnson, Julene B.; Kruman, Bryce A.; Orton, Taylor S.; Cook, Ryan B.; Eggett, Dennis L.; Weber, K. Scott

    2016-01-01

    Concerns about energy consumption and climate change make residential evaporative coolers a popular alternative to central air conditioning in arid and semi-arid climates. However, evaporative coolers have been shown to significantly increase indoor relative humidity and dust mite allergen levels in some studies, while showing no association in other studies. Improved measurement of temporal fluctuations in indoor relative humidity may help identify factors that promote mite growth in homes in dry climates. Dust samples and continuous indoor relative humidity measurements were collected from homes with central air conditioning and homes with evaporative coolers in Utah. Samples were collected over two seasons, winter/spring (Jan–Apr) and summer (July–Sept), 2014. Dust samples were analyzed for Der p 1 and Der f 1 using a two-site monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) analysis. Housing characteristics including age of home, occupant density, and age of mattresses, furniture, and carpeting were also measured. Positive Der p 1 or Der f 1 samples were found in 25.0% of the homes and there was no difference in mean allergen levels by type of air conditioning. Indoor relative humidity was significantly higher in homes with evaporative coolers compared to those with central air conditioning during the summer. Homes with evaporative coolers also spent significantly more time during summer above 55.0% and 65.0% relative humidity compared to central air homes, but not above 75.0%. Findings from this study suggest that increased humidity from evaporative coolers may not be sufficient to exceed the critical equilibrium humidity or maintain humidity excursions for sufficient duration in relatively larger single-family homes in semi-arid climates to support mite growth and reproduction. PMID:26808528

  2. Exposure matrices of endotoxin, (1→3)-β-d-glucan, fungi, and dust mite allergens in flood-affected homes of New Orleans.

    PubMed

    Adhikari, Atin; Lewis, Jocelyn Suzanne; Reponen, Tiina; Degrasse, Enjoli C; Grimsley, L Faye; Chew, Ginger L; Iossifova, Yulia; Grinshpun, Sergey A

    2010-10-15

    This study examined: (i) biocontaminant levels in flooded homes of New Orleans two years after the flooding; (ii) seasonal changes in biocontaminant levels, and (iii) correlations between biocontaminant levels obtained by different environmental monitoring methods. Endotoxin, (1→3)-β-d-glucan, fungal spores, and dust mite allergens were measured in 35 homes during summer and winter. A combination of dust sampling, aerosolization-based microbial source assessment, and long-term inhalable bioaerosol sampling aided in understanding exposure matrices. On average, endotoxin found in the aerosolized fraction accounted for <2% of that measured in the floor dust, suggesting that vacuuming could overestimate inhalation exposures. In contrast, the (1→3)-β-d-glucan levels in the floor dust and aerosolized fractions were mostly comparable, and 25% of the homes showed aerosolizable levels even higher than the dust-borne levels. The seasonal patterns for endotoxin in dust and the aerosolizable fraction were different from those found for (1→3)-β-d-glucan, reflecting the temperature and humidity effects on bacterial and fungal contamination. While the concentration of airborne endotoxin followed the same seasonal trend as endotoxin aerosolized from surfaces, no significant seasonal difference was identified for the concentrations of airborne (1→3)-β-d-glucan and fungal spores. This was attributed to the difference in the particle size; smaller endotoxin-containing particles can remain airborne for longer time than larger fungal spores or (1→3)-β-d-glucan-containing particles. It is also possible that fungal aerosolization in home environments did not reach its full potential. Detectable dust mite allergens were found only in dust samples, and more commonly in occupied homes. Levels of endotoxin, (1→3)-β-d-glucan, and fungi in air had decreased during the two-year period following the flooding as compared to immediate measurements; however, the dust

  3. House Dust Mite-Derived Chitin Enhances Th2 Cell Response to Inhaled Allergens, Mainly via a TNF-α-Dependent Pathway

    PubMed Central

    Choi, Jun-Pyo; Lee, Sang-Min; Choi, Hyun-Il; Kim, Min-Hye; Jeon, Seong Gyu; Jang, Myoung Ho; Jee, Young-Koo; Yang, Sanghwa; Cho, Young-Joo

    2016-01-01

    Purpose Chitin is a potent adjuvant in the development of immune response to inhaled allergens in the airways. According to other studies, chitin is known as multi-faced adjuvants which can induce Th2 responses. Recently, we found that TNF-α is a key mediator in the development of Th2 cell response to inhaled allergens. Here, we evaluated the immunologic mechanisms in the development of airway hypersensitivity to inhaled allergens, enhanced by house dust mite (HDM)-derived chitin. Methods The role of TNF-α and TLRs was evaluated in an airway hypersensitivity mouse model induced by a sensitization with an allergen (ovalbumin, OVA) and HDM-derived chitin using mice with the null mutation of target genes. Results The present study showed that airway sensitization with HDM-derived chitin plus OVA enhanced OVA-induced airway inflammation v. OVA alone. This phenotype was associated with the increased expression of Th1, Th2, and Th17 cytokines and also with the enhanced production of OVA-specific IgE, IgG1, and IgG2a. As for T cell responses, OVA-specific Th2 cell response, enhanced by chitin, was abolished by the treatment of chitinase, whereas Th1 and Th17 cell responses enhanced by this treatment. Moreover, the null mutation of the TNF-α gene revealed similar effects as the chitinase treatment. In contrast, all the OVA-specific T cell responses, enhanced by chitin, were blocked by the absence of TLR2, but not of TLR1, TLR4, or TLR6. Conclusions In conclusion, these data suggest that HDM-derived chitin may enhance airway hypersensitivity to inhaled allergens, via the TLR2-dependent pathway, and that chitin-induced TNF-α can be a key mediator in the development of Th2 cell response to inhaled allergens. PMID:27126730

  4. A sensitive fluorescent assay for measuring the cysteine protease activity of Der p 1, a major allergen from the dust mite Dermatophagoides pteronyssinus.

    PubMed Central

    Schulz, O; Sewell, H F; Shakib, F

    1998-01-01

    The potent allergenicity of Der p 1, a major allergen of the house dust mite Dermatophagoides pteronyssinus, is thought to be related to its cysteine protease activity. Therefore, there is considerable interest in developing a sensitive assay for measuring Der p 1 activity to screen for specific inhibitors. This study demonstrates for the first time that the activity of Der p 1 can be measured conveniently in a continuous rate assay with the fluorogenic substrate Boc-Gln-Ala-Arg-AMC (K(m) = 280 microM and kcat/K(m) = 4.6 x 10(3)/M/s). PMID:9893750

  5. Crystallization and preliminary X-ray analysis of Der f 2, a potent allergen derived from the house dust mite (Dermatophagoides farinae)

    NASA Technical Reports Server (NTRS)

    Roeber, Dana; Achari, Aniruddha; Takai, Toshiro; Okumura, Yasushi; Scott, David L.

    2003-01-01

    Although a number of allergens have been identified and isolated, the underlying molecular basis for the potent immune response is poorly understood. House dust mites (Dermatophagoides sp.) are ubiquitous contributors to atopy in developed countries. The rhinitis, dermatitis and asthma associated with allergic reactions to these arthropods are frequently caused by relatively small (125-129 amino acids) mite proteins of unknown biological function. Der f 2, a major allergen from the mite D. farinae, has been recombinantly expressed, characterized and crystallized. The crystals belong to the tetragonal space group I4(1)22, with unit-cell parameters a = b = 95.2, c = 103.3 A. An essentially complete (97.2%) data set has been collected to 2.4 A at a synchrotron source. Attempts to solve the crystal structure of Der f 2 by molecular replacement using the NMR coordinates for either Der f 2 or Der p 2 (the homologous protein from D. pteronyssinus) failed, but preliminary searches using the crystalline Der p 2 atomic coordinates appear to be promising.

  6. Association of house dust mite-specific IgE with asthma control, medications and household pets

    PubMed Central

    Ramos, John Donnie A.

    2011-01-01

    Background Evidence is conflicting regarding the effectiveness of creating a low-allergen environment or reducing allergen exposure to control asthma exacerbations. Objective This study determined the association of house dust mite (HDM)-specific IgE levels with asthma symptom control, selected medications, family history of allergic disease, and exposure to second-hand smoke and household pets. Methods Serum samples from 102 doctor-diagnosed allergic asthma patients and 100 non-atopic controls were subjected to enzyme-linked immunosorbent assay using the HDM species Dermatophagoides pteronyssinus (Dp), Dermatophagoides farinae (Df), and Blomia tropicalis (Bt) allergens. Point-biserial correlation coefficient, Pearson R correlation, and logistic regression analyses were used to determine association of HDM-specific IgE levels with the abovementioned variables. Results Of the 102 cases, 38.24%, 47.06%, and 33.33% were sensitized to Bt, Df, and Dp, respectively. Sensitized patients showed greater probability [Bt (OR = 1.21), Df (OR = 1.14), and Dp (OR = 1.35)] to manifest symptoms than those who were not. Obtained p-values [Bt (p = 0.73), Df (p = 0.83), and Dp (p = 0.59)], however, proved that HDM-specific IgE levels had no significant contribution in predicting or explaining occurrence of asthma symptoms. Bt- and Df-specific IgEs showed moderately weak but significant relationship with bambuterol HCl and expectorant, respectively. Patients currently on said medications registered higher HDM-specific IgE levels than those who were not. No significant correlation between IgE levels and family history of allergic disease or with exposure to second-hand smoke was seen. Dp-specific IgE levels of patients exposed to household pets were significantly lower compared to those without exposure. Conclusion This study proves that sensitization to Bt, Df, and Dp allergens is not significantly associated with asthma symptoms and control. Although cases were shown to be sensitized

  7. Characteristics of Allergic Pulmonary Inflammation in CXCR3Knockout Mice Sensitized and Challenged with House Dust Mite Protein

    PubMed Central

    Chen, Xiaolan; Gao, Jinming; Guo, Zijian

    2016-01-01

    Chemokine C-X-C motif receptor 3 (CXCR3) is a chemokine receptor that is mainly expressed by activated T lymphocytes. T cells play important roles in allergic pulmonary inflammation, which is a hallmark of asthma and elicits the localized accumulation of activated T cells in the lung. In China, a marked increase in the incidence rate of chronic allergic pulmonary inflammation has made it a major public health threat. In the present study, we investigated the role of CXCR3 and its ligands in airway inflammation induced by house dust mite protein (HDMP) in a CXCR3 knockout (CXCR3KO) asthma mouse model. Pathological manifestations in the lung, cell counts and bronchoalveolar lavage fluid (BALF) classifications were studied using hematoxylin and eosin (H&E) staining. The levels of IL-4 and IFN-γ in the BALF and splenocyte supernatants were measured using ELISA. CD4+ and CD8+ T cells in the lung and spleen were analyzed by flow cytometry. RT-PCR was applied to measure the mRNA transcript levels of monokines induced by IFN-γ(CXCL9) and IFN-γ inducible protein 10(CXCL10). The total cell counts, eosinophil counts, and IL-4 levels in the BALF and cultured splenocyte supernatants were significantly increased, while the levels of IFN-γ were reduced in the HDMP groups(P<0.01). Changes in the total cell counts, eosinophil counts, and lymphocyte counts, as well as the total protein levels in the BALF, the levels of IL-4 in splenocyte supernatants, and the pathological manifestations in the lung, were all greater in CXCR3KO mice than in C57BL/6 wild-type mice. Furthermore, the expression levels of CXCL9 and CXCL10 mRNA transcripts in the lungs of CXCR3KO mice were lower than those in C57BL/6 wild-type mice (P<0.05). CXCR3 and its ligands (i.e., CXCL9 and CXCL10) may play anti-inflammatory roles in this animal model. Promoting the expression of CXCR3 and its ligands may represent a novel therapeutic approach for preventing and curing asthma. PMID:27727269

  8. Effect of Amino Acid Polymorphisms of House Dust Mite Der p 2 Variants on Allergic Sensitization

    PubMed Central

    Tanyaratsrisakul, Sasipa; Jirapongsananuruk, Orathai; Kulwanich, Bhakkawarat; Hales, Belinda J.; Thomas, Wayne R.

    2016-01-01

    Purpose The sequence variations of the Der p 2 allergen of Dermatophagoides pteronyssinus diverge along 2 pathways with particular amino acid substitutions at positions 40,47,111, and 114. The environmental prevalence and IgE binding to Der p 2 variants differ among regions. To compare IgE binding to Der p 2 variants between sera from Bangkok, Thailand and Perth, Western Australia with different variants and to determine the variant-specificity of antibodies induced by vaccination with recombinant variants. Methods The structures of recombinant variants produced in yeast were compared by circular dichroism and 1-anilinonaphthalene 8-sulfonic acid staining of their lipid-binding cavity. Sera from subjects in Bangkok and Perth where different variants are found were compared by the affinity (IC50) of IgE cross-reactivity to different variants and by direct IgE binding. Mice were immunized with the variants Der p 2.0101 and Der p 2.0110, and their IgG binding to Der p 2.0103, 2.0104, and 2.0109 was measured. Results The secondary structures of the recombinant variants resembled the natural allergen but with differences in ANS binding. The IC50 of Der p 2.0101 required 7-fold higher concentrations to inhibit IgE binding to the high-IgE-binding Der p 2.0104 than for homologous inhibition in sera from Bangkok where it is absent, while in sera from Perth that have both variants the IC50 was the same and low. Reciprocal results were obtained for Der p 2.0110 not found in Perth. Direct binding revealed that Der p 2.0104 was best for detecting IgE in both regions, followed by Der p 2.0101 with binding to other variants showing larger differences. Mouse anti-Der p 2.0101 antibodies had a high affinity of cross-reactivity but bound poorly to other variants. Conclusions The affinity of IgE antibody cross-reactivity, the direct IgE binding, and the specificities of antibodies induced by vaccination show that measures of allergic sensitization and therapeutic strategies could be

  9. Supernovae. Old supernova dust factory revealed at the Galactic center.

    PubMed

    Lau, R M; Herter, T L; Morris, M R; Li, Z; Adams, J D

    2015-04-24

    Dust formation in supernova ejecta is currently the leading candidate to explain the large quantities of dust observed in the distant, early universe. However, it is unclear whether the ejecta-formed dust can survive the hot interior of the supernova remnant (SNR). We present infrared observations of ~0.02 solar masses of warm (~100 kelvin) dust seen near the center of the ~10,000-year-old Sagittarius A East SNR at the Galactic center. Our findings indicate the detection of dust within an older SNR that is expanding into a relatively dense surrounding medium (electron density ~10(3) centimeters(-3)) and has survived the passage of the reverse shock. The results suggest that supernovae may be the dominant dust-production mechanism in the dense environment of galaxies of the early universe.

  10. Supernovae. Old supernova dust factory revealed at the Galactic center.

    PubMed

    Lau, R M; Herter, T L; Morris, M R; Li, Z; Adams, J D

    2015-04-24

    Dust formation in supernova ejecta is currently the leading candidate to explain the large quantities of dust observed in the distant, early universe. However, it is unclear whether the ejecta-formed dust can survive the hot interior of the supernova remnant (SNR). We present infrared observations of ~0.02 solar masses of warm (~100 kelvin) dust seen near the center of the ~10,000-year-old Sagittarius A East SNR at the Galactic center. Our findings indicate the detection of dust within an older SNR that is expanding into a relatively dense surrounding medium (electron density ~10(3) centimeters(-3)) and has survived the passage of the reverse shock. The results suggest that supernovae may be the dominant dust-production mechanism in the dense environment of galaxies of the early universe. PMID:25791082

  11. SURVIVAL OF THE HOUSE DUST MITE, DERMATOPHAGOIDES FARINAE, AT HIGH TEMPERATURES (40-80°C)

    EPA Science Inventory

    Experiments were conducted to evaluate the survival time of randomly selected female D. farinae exposed to temperatures from 40 to 80 degrees C and relative humidities (RHs) between 10 and 90%. Significant temperature effects were found on the length of time mites can survive at ...

  12. Protective effects of a recombinant fragment of human surfactant protein D in a murine model of pulmonary hypersensitivity induced by dust mite allergens.

    PubMed

    Singh, Mamta; Madan, Taruna; Waters, Patrick; Parida, Shreemanta K; Sarma, P Usha; Kishore, Uday

    2003-05-01

    Lung surfactant protein D (SP-D) is a carbohydrate pattern recognition immune molecule. It can interact with a range of pathogens, stimulate immune cells and manipulate cytokine profiles during host's immune response. SP-D has also been shown to interact, via its carbohydrate recognition domains, with glycoprotein allergens of house dust mite (Dermatophagoides pteronyssinus, Derp), inhibiting specific IgE isolated from mite-sensitive asthmatic patients from binding these allergens, and blocking subsequent histamine release from sensitized basophils. In the present study, we have examined the protection offered by various doses of intranasal administration of a recombinant fragment of human SP-D (rhSP-D) in a murine model of pulmonary hypersensitivity to Derp allergens which showed characteristic high levels of specific IgE antibodies, peripheral blood eosinophilia, pulmonary infiltrates and a Th2 cytokine response. Treatment of Derp mice with rhSP-D led to significant reduction in Derp-specific IgE levels, blood eosinophilia and pulmonary cellular infiltration. The levels of IL-4 and IL-5 were decreased, while those of IL-12 and IFN-gamma were raised in the supernatant of the cultured splenocytes, indicating a Th2 to Th1 polarization. These results suggest that SP-D has a protective role in the modulation of allergic sensitization and in the development of allergic reactions to Derp allergens and highlight potential of the rhSP-D as a therapeutic for pulmonary hypersensitivity. PMID:12706535

  13. The Discovery of Potent, Selective, and Reversible Inhibitors of the House Dust Mite Peptidase Allergen Der p 1: An Innovative Approach to the Treatment of Allergic Asthma

    PubMed Central

    2014-01-01

    Blocking the bioactivity of allergens is conceptually attractive as a small-molecule therapy for allergic diseases but has not been attempted previously. Group 1 allergens of house dust mites (HDM) are meaningful targets in this quest because they are globally prevalent and clinically important triggers of allergic asthma. Group 1 HDM allergens are cysteine peptidases whose proteolytic activity triggers essential steps in the allergy cascade. Using the HDM allergen Der p 1 as an archetype for structure-based drug discovery, we have identified a series of novel, reversible inhibitors. Potency and selectivity were manipulated by optimizing drug interactions with enzyme binding pockets, while variation of terminal groups conferred the physicochemical and pharmacokinetic attributes required for inhaled delivery. Studies in animals challenged with the gamut of HDM allergens showed an attenuation of allergic responses by targeting just a single component, namely, Der p 1. Our findings suggest that these inhibitors may be used as novel therapies for allergic asthma. PMID:25365789

  14. House dust mites possess a polymorphic, single domain putative peptidoglycan d,l endopeptidase belonging to the NlpC/P60 Superfamily

    PubMed Central

    Tang, Vivian H.; Stewart, Geoffrey A.; Chang, Barbara J.

    2015-01-01

    A 14 kDa protein homologous to the γ-d-glutamyl-l-diamino acid endopeptidase members of the NlpC/P60 Superfamily has been described in Dermatophagoides pteronyssinus and Dermatophagoides farinae but it is not clear whether other species produce homologues. Bioinformatics revealed homologous genes in other Sarcopteformes mite species (Psoroptes ovis and Blomia tropicalis) but not in Tetranychus urticae and Metaseiulus occidentalis. The degrees of identity (similarity) between the D. pteronyssinus mature protein and those from D. farinae, P. ovis and B. tropicalis were 82% (96%), 77% (93%) and 61% (82%), respectively. Phylogenetic studies showed the mite proteins were monophyletic and shared a common ancestor with both actinomycetes and ascomycetes. The gene encoding the D. pteronyssinus protein was polymorphic and intronless in contrast to that reported for D. farinae. Homology studies suggest that the mite, ascomycete and actinomycete proteins are involved in the catalysis of stem peptide attached to peptidoglycan. The finding of a gene encoding a P60 family member in the D. pteronyssinus genome together with the presence of a bacterial promotor suggests an evolutionary link to one or more prokaryotic endosymbionts. PMID:26566476

  15. [Ecological study of Pyroglyphides mites in house dust in the Grenoble area. A qualitative approach and incidence of various parameters: seasons, altitude, temperature and relative dampness in their multiplication].

    PubMed

    Lascaud, D

    1978-01-01

    This study concerns the analysis of 70 samples of dust mites taken periodically from 13 sample areas or mattresses at different altitudes. It shows the presence of Pyroglyphid mites in all the mattresses studied. Four species were found: Dermatophagoides pteronyssinus, Dermatophagoides farinae, Euroglyphus maynei and Dermatophagoides evansi. From a quantitative point of view, the statistical analysis of the results obtained allows the following conclusions to be drawn: -- All the Pyroglyphids (adults and young) undergo seasonal fluctuations at low, middle and high altitude. In the plains and at middle altitude these mites have a seasonal maximum and minimum. At high altitude only the seasonal maximum can be determined. -- The number of Pyroglyphids found is much higher in the plaine than at middle altitude and at middle altitude than at high altitude. The influence of altitude can be demonstrated with certitude. -- The conditions of temperature and relative dampness most favourable to the multiplication of mites are found in the plaine. At middle and high altitude these conditions are only met in summer. In flat country the statistical analysis allows us to show the existance of a correlation between the rate of dampness and the number of Pyroglyphids, and more specially, between the dampness rate and Dermatophagoides farinae, a predominant species at this sampling area. At middle and high altitude such a correlation cannot be shown clearly. At the three altitudes considered, no correlation can be established between the temperature and the number of Pyroglyphid mites found.

  16. Regulation of CBL and ESR1 expression by microRNA-22‑3p, 513a-5p and 625-5p may impact the pathogenesis of dust mite-induced pediatric asthma.

    PubMed

    Dong, Xiaoyan; Xu, Miao; Ren, Zhaorui; Gu, Jianlei; Lu, Min; Lu, Quan; Zhong, Nanbert

    2016-08-01

    Despite evidence for the involvement of microRNAs (miRNAs or miRs) in pediatric asthma, the mechanism responsible has not yet been fully elucidated. We aimed to identify novel miRNAs and to study their pathogenic role(s) in children with dust mite-induced asthma in order to gain a better understanding of the underlying mechanism responsible for this disease. For this purpose, 62 patients with asthma as well as 62 age- and gender-matched healthy controls were recruited. Twelve pairs of subjects were randomly subjected to microarray-based discovery analysis using a miRCURY LNA™ array. The differential expression of miRNAs and their targeted messenger RNAs were validated using RT-qPCR. Plasma concentrations of cytokines were determined using an enzyme-linked immunosorbent assay (ELISA) kit. The results revealed that three novel miRNAs - miR-22-3p, miR‑513a-5p and miR-625-5p - were significantly downregulated in the asthma group compared with the control group (p<0.01), whereas the transcript levels of Cbl proto-oncogene, E3 ubiquitin protein ligase (CBL), peroxisome proliferator‑activated receptor gamma, coactivator 1 beta (PPARGC1B), and estrogen receptor 1 (ESR1) that are targeted by these miRNAs were increased (p<0.01). There were significant differences in the plasma concentrations of γ-interferon, tumor necrosis factor-α, interleukin (IL)-12 and IL-10 between the two groups (p<0.05). Thus, miR-513a-5p, miR-22-3p and miR-625-5p may have an impact on the regulation of the immune response and inflammatory cytokine pathways through the regulation of their target gene(s), CBL, PPARGC1B and ESR1, which may then lead to a dust mite-induced asthma attack. Our findings may provide novel insights into the pathogenesis of pediatric asthma. PMID:27277384

  17. Regulation of CBL and ESR1 expression by microRNA-22-3p, 513a-5p and 625-5p may impact the pathogenesis of dust mite-induced pediatric asthma

    PubMed Central

    Dong, Xiaoyan; Xu, Miao; Ren, Zhaorui; Gu, Jianlei; Lu, Min; Lu, Quan; Zhong, Nanbert

    2016-01-01

    Despite evidence for the involvement of microRNAs (miRNAs or miRs) in pediatric asthma, the mechanism responsible has not yet been fully elucidated. We aimed to identify novel miRNAs and to study their pathogenic role(s) in children with dust mite-induced asthma in order to gain a better understanding of the underlying mechanism responsible for this disease. For this purpose, 62 patients with asthma as well as 62 age- and gender-matched healthy controls were recruited. Twelve pairs of subjects were randomly subjected to microarray-based discovery analysis using a miRCURY LNA™ array. The differential expression of miRNAs and their targeted messenger RNAs were validated using RT-qPCR. Plasma concentrations of cytokines were determined using an enzyme-linked immunosorbent assay (ELISA) kit. The results revealed that three novel miRNAs - miR-22-3p, miR-513a-5p and miR-625-5p - were significantly downregulated in the asthma group compared with the control group (p<0.01), whereas the transcript levels of Cbl proto-oncogene, E3 ubiquitin protein ligase (CBL), peroxisome proliferator-activated receptor gamma, coactivator 1 beta (PPARGC1B), and estrogen receptor 1 (ESR1) that are targeted by these miRNAs were increased (p<0.01). There were significant differences in the plasma concentrations of γ-interferon, tumor necrosis factor-α, interleukin (IL)-12 and IL-10 between the two groups (p<0.05). Thus, miR-513a-5p, miR-22-3p and miR-625-5p may have an impact on the regulation of the immune response and inflammatory cytokine pathways through the regulation of their target gene(s), CBL, PPARGC1B and ESR1, which may then lead to a dust mite-induced asthma attack. Our findings may provide novel insights into the pathogenesis of pediatric asthma. PMID:27277384

  18. Associations of allergic sensitization and clinical phenotypes with innate immune response genes polymorphisms are modified by house dust mite allergen exposure

    PubMed Central

    Kurowski, Marcin; Majkowska-Wojciechowska, Barbara; Wardzyńska, Aleksandra

    2011-01-01

    Introduction Polymorphisms within innate immunity genes are associated with allergic phenotypes but results are variable. These associations were not analyzed with respect to allergen exposure. We investigated associations of TLR and CD14 polymorphisms with allergy phenotypes in the context of house dust mite (HDM) exposure. Material and methods Children, aged 12-16 years (n=326), were recruited from downtown and rural locations and assessed by allergist. Skin prick tests, total and HDM-specific sIgE measurements were done. HDM allergen concentrations in dust were measured. Genetic polymorphisms were identified using restriction fragment length polymorphism (RFLP). Results Allergic rhinitis, asthma and atopy were more prevalent in urban area. Although HDM allergen concentrations were higher in rural households, sIgE were present more frequently in urban children. In the whole population no association was found between HDM exposure and sensitization. In children with CD14/−159CC, CD14/−159TT and TLR9/2848GA genotypes increased exposure to HDM was associated with reduced incidence of allergic rhinitis. Significant associations of increased HDM exposure with reduced incidence of atopy were found for the whole population and subjects with CD14/−159CC, CD14/−1359GT, TLR4/896AA and TLR9/2848GA genotypes. Among children with CD14/−159CC and CD14/−1359GG significant positive correlation between HDM allergen concentrations in household and sensitization to HDM was observed. In contrast, protective effect of high HDM allergen exposure against specific sensitization was seen in subjects with TLR4/896 AG. Conclusions Development of specific sensitization and allergy may be associated with innate immune response genes polymorphisms and is modified by allergen exposure. PMID:22328887

  19. Repetitive Immunoassay with a Surface Acoustic Wave Device and a Highly Stable Protein Monolayer for On-Site Monitoring of Airborne Dust Mite Allergens.

    PubMed

    Toma, Koji; Miki, Daisuke; Kishikawa, Chisato; Yoshimura, Naoyuki; Miyajima, Kumiko; Arakawa, Takahiro; Yatsuda, Hiromi; Mitsubayashi, Kohji

    2015-10-20

    This work describes a sensor to be incorporated into the on-site monitoring system of airborne house dust mite (HDM) allergens. A surface acoustic wave (SAW) device was combined with self-assembled monolayers of a highly stable antibody capture protein on the SAW surface that have high resistance to pH change. A sandwich assay was used to measure a HDM allergen, Der f 1 derived from Dermatophagoides farinae. Capture antibodies were cross-linked to a protein G based capture layer (ORLA85) on the sensor surface, thereby only Der f 1 and detection antibodies were regenerated by changing pH, resulting in fast repetition of the measurement. The sensor was characterized through 10 repetitive measurements of Der f 1, which demonstrated high reproducibility of the sensor with the coefficient of variation of 5.6%. The limit of detection (LOD) of the sensor was 6.1 ng·mL(-1), encompassing the standard (20 ng·mL(-1)) set by the World Health Organization. Negligible sensor outputs were observed for five different major allergens including other HDM allergens which tend to have cross-reactivity to Der f 1 and their mixtures with Der f 1. Finally, the sensor lifetime was evaluated by conducting three measurements per day, and the sensor output did not substantially change for 4 days. These characteristics make the SAW immunosensor a promising candidate for incorporation into on-site allergen monitoring systems.

  20. Pruni cortex ameliorates skin inflammation possibly through HMGB1-NFκB pathway in house dust mite induced atopic dermatitis NC/Nga transgenic mice

    PubMed Central

    Watanabe, Kenichi; Karuppagounder, Vengadeshprabhu; Arumugam, Somasundaram; Thandavarayan, Rajarajan A.; Pitchaimani, Vigneshwaran; Sreedhar, Remya; Afrin, Rejina; Harima, Meilei; Suzuki, Hiroshi; Suzuki, Kenji; Nakamura, Takashi; Nomoto, Mayumi; Miyashita, Shizuka; Fukumoto, Kyoko; Ueno, Kazuyuki

    2015-01-01

    Pruni cortex, the bark of Prunus jamasakura Siebold ex Koidzumi, has been used in the Japanese systems of medicine for many years for its anti-inflammatory, antioxidant and antitussive properties. In this study, we investigated the effect of pruni cortex on atopic dermatitis NC/Nga mouse model. Atopic dermatitis-like lesion was induced by the application of house dust mite extract to the dorsal skin. After induction of atopic dermatitis, pruni cortex aqueous extract (1 g/kg, p.o.) was administered daily for 2 weeks. We evaluated dermatitis severity, histopathological changes and cellular protein expression by Western blotting for nuclear and cytoplasmic high mobility group box 1, receptor for advanced glycation end products, nuclear factor κB, apoptosis and inflammatory markers in the skin of atopic dermatitis mice. The clinical observation confirmed that the dermatitis score was significantly lower when treated with pruni cortex than in the atopic dermatitis group. Similarly pruni cortex inhibited hypertrophy and infiltration of inflammatory cells as identified by histopathology. In addition, pruni cortex significantly inhibited the protein expression of cytoplasmic high mobility group box 1, receptor for advanced glycation end products, nuclear p-nuclear factor kappa B, apoptosis and inflammatory markers. These results indicate that pruni cortex may have therapeutic potential in the treatment of atopic dermatitis by attenuating high mobility group box 1 and inflammation possibly through the nuclear factor κB pathway. PMID:26060348

  1. The Hot-Water Extract of Smilacis Chinae Rhizome Suppresses 2,4-Dinitrochlorobenzene and House Dust Mite-Induced Atopic Dermatitis-Like Skin Lesions in Mice.

    PubMed

    Ki, Nam Yong; Park, Eun-Ji; Sung, In sung; Ju, Seul A; Kim, Kyoung Un; Kim, Mi Rae; Song, Do Yeon; Lee, Min-Ju; Kim, Hak-Soo; Kang, Boo-Hyon; Chung, Hun-Jong; Choi, Eun-Ju; Yoon, Ki-Hun; Lee, Min Won; Yun, Seongho; Min, Bokkee; Kwon, Suk Hyung; Shin, Hwa-Sup

    2016-04-01

    Smilacis Chinae Rhizome (SCR) has been used as an oriental folk medicine for various biological activities. However, its effect on atopic dermatitis (AD) remains undetermined to date. We assessed the effect of orally administered hot-water extract of SCR on AD-like skin lesions in mice and its underlying mechanisms. AD-like murine model was prepared by repeated alternate application of house dust mite (Dermatophagoides farinae) extract (DFE) and 2,4-dinitrochlorobenzene (DNCB) for 4 weeks, topically to the ears. Daily oral administration of SCR for 3 and 4 weeks significantly reduced inflammatory ear thickening, with the effect being enhanced at the earlier start and longer period of administration. This effect was accompanied by a significant decrease in both Th2 and Th1 serum antibodies (total IgE, DFE-specific IgE, and IgG2a). Histological analysis showed that SCR markedly decreased the epidermal/dermal ear thickening and the dermal infiltration of inflammatory cells. Furthermore, SCR suppressed DFE/DNCB-induced expression of IL-4, IL-13, IL-17, IL-18, TSLP, and IFN-γ genes in the ear tissue. Taken together, our observations demonstrate that chronic oral administration of SCR exerts beneficial effect in mouse AD model, suggesting that SCR has the therapeutic potential as an orally active treatment of AD by modulating both Th1 and Th2 responses.

  2. Sensitization by subcutaneous route is superior to intraperitoneal route in induction of asthma by house dust mite in a murine mode

    PubMed Central

    Aun, Marcelo Vivolo; Saraiva-Romanholo, Beatriz Mangueira; de Almeida, Francine Maria; Brüggemann, Thayse Regina; Kalil, Jorge; Martins, Milton de Arruda; Arantes-Costa, Fernanda Magalhães; Giavina-Bianchi, Pedro

    2015-01-01

    ABSTRACT Objective To develop a new experimental model of chronic allergic pulmonary disease induced by house dust mite, with marked production of specific immunoglobulin E (IgE), eosinophilic inflammatory infiltrate in the airways and remodeling, comparing two different routes of sensitization. Methods The protocol lasted 30 days. BALB/c mice were divided into six groups and were sensitized subcutaneously or intraperitoneally with saline (negative control), Dermatophagoides pteronyssinus (Der p) 50 or 500mcg in three injections. Subsequently they underwent intranasal challenge with Der p or saline for 7 days and were sacrificed 24 hours after the last challenge. We evaluated the titration of specific IgE anti-Der p, eosinophilic density in peribronchovascular space and airway remodeling. Results Both animals sensitized intraperitoneally and subcutaneously produced specific IgE anti-Der p. Peribronchovascular eosinophilia increased only in mice receiving lower doses of Der p. However, only the group sensitized with Der p 50mcg through subcutaneously route showed significant airway remodeling. Conclusion In this murine model of asthma, both pathways of sensitization led to the production of specific IgE and eosinophilia in the airways. However, only the subcutaneously route was able to induce remodeling. Furthermore, lower doses of Der p used in sensitization were better than higher ones, suggesting immune tolerance. Further studies are required to evaluate the efficacy of this model in the development of bronchial hyperresponsiveness, but it can already be replicated in experiments to create new therapeutic drugs or immunotherapeutic strategies. PMID:26761554

  3. Cloning, expression, purification, crystallization and preliminary X-ray diffraction studies of a major group 7 allergen, Der f 7, from the dust mite Dermatophagoides farinae.

    PubMed

    Tan, Kang Wei; Kumar, Sundramurthy; Chew, Fook Tim; Mok, Yu Keung

    2011-12-01

    Der f 7 is a major group 7 allergen from the dust mite Dermatophagoides farinae that shows 86% sequence identity to the homologous allergen Der p 7 from D. pteronyssinus. Der f 7 was successfully overexpressed in an Escherichia coli expression system and purified to homogeneity using Ni-NTA affinity and size-exclusion column chromatography. SeMet-labelled Der f 7 was crystallized by the hanging-drop vapour-diffusion method using a reservoir solution consisting of 0.1 M bis-tris pH 7.4 and 28% polyethylene glycol monomethyl ether 2000 at 293 K. X-ray diffraction data were collected to 2.24 Å resolution using synchrotron radiation. The crystals belonged to the orthorhombic system, space group P2(1)2(1)2(1), with unit-cell parameters a = 50.19, b = 58.67, c = 123.81 Å. Based on the estimated Matthews coefficient (2.16 Å(3) Da(-1)), two molecules of Der f 7 could be present in the asymmetric unit of the crystal lattice.

  4. House dust mite allergen Der f 1 induces IL-8 in human basophilic cells via ROS-ERK and p38 signal pathways.

    PubMed

    Yi, Myung-hee; Kim, Hyoung-Pyo; Jeong, Kyoung Yong; Kim, Chung-Ryul; Kim, Tae Yun; Yong, Tai-Soon

    2015-10-01

    Der f 1, a major house dust mite allergen and member of the papain-like cysteine protease family, can provoke immune responses with its proteolytic activity. To understand the role of Der f 1 in inflammatory immune responses, we studied the mechanism of the regulation of interleukin (IL)-8 expressions in human basophilic cell KU812 by proteolytically active recombinant Der f 1. Not only production of IL-8 mRNA was induced but also the DNA binding activity of activator protein-1 (AP-1) and phosphorylation of NF-κB p65 were increased in Der f 1-treated KU812. Furthermore, Der f 1 induction of IL-8 expression was sensitive to pharmacological inhibition of ERK and p38 mitogen activated protein kinase (MAPK) pathways. Der f 1 also activated ERK and p38 MAPK phosphorylation and rapidly induced reactive oxygen species (ROS) production. The antioxidant N-acetyl-cysteine (NAC) inhibited phosphorylation of ERK, but not p38, suggesting that secretion of IL-8 in KU812 cells treated with Der f 1 is dependent on ROS, ERK MAPK and p38 MAPK. We describe the mechanism of Der f 1-induced IL-8 secretion from human basophilic cells, which are thought to be important for allergic inflammation independent of IgE antibodies. These findings improve our understanding of the inflammatory immune response in human basophils to protease allergens.

  5. [Sensitization to granary mites in patients with allergic diseases].

    PubMed

    Golysheva, M A

    1991-01-01

    As many as 71 patients selected from a group of 550 patients suffering from allergic diseases, sensitized to the house dust mites Dermatophagoides pteronyssinus were examined. A study was made of the presence of allergen-specific IgE antibodies against house dust mites, storage mites (7 species altogether) using allergenic discs and commercial kits RAST (Pharmacia, Sweden). The group under examination mostly manifested sensitization to the house dust mites: Dermatophagoides ferinae (80%), Euroglyphus maynei (55%); storage mites: Acarus siro (45%), Lepidoglyphus destructor (35%). The latter one possesses the most powerful allergenic properties as compared to the acaroid mites of other types. The elevated sensitivity to storage mites is encountered among adults and children living both in Moscow and other regions (urban and rural). The problem of sensitization to storage mites in the USSR mandates thorough studies, which will enable the treatment and diagnostic agents to be designed and introduced into practice.

  6. Quantitative PCR-based genome size estimation of the astigmatid mites Sarcoptes scabiei, Psoroptes ovis and Dermatophagoides pteronyssinus

    PubMed Central

    2012-01-01

    Background The lack of genomic data available for mites limits our understanding of their biology. Evolving high-throughput sequencing technologies promise to deliver rapid advances in this area, however, estimates of genome size are initially required to ensure sufficient coverage. Methods Quantitative real-time PCR was used to estimate the genome sizes of the burrowing ectoparasitic mite Sarcoptes scabiei, the non-burrowing ectoparasitic mite Psoroptes ovis, and the free-living house dust mite Dermatophagoides pteronyssinus. Additionally, the chromosome number of S. scabiei was determined by chromosomal spreads of embryonic cells derived from single eggs. Results S. scabiei cells were shown to contain 17 or 18 small (< 2 μM) chromosomes, suggesting an XO sex-determination mechanism. The average estimated genome sizes of S. scabiei and P. ovis were 96 (± 7) Mb and 86 (± 2) Mb respectively, among the smallest arthropod genomes reported to date. The D. pteronyssinus genome was estimated to be larger than its parasitic counterparts, at 151 Mb in female mites and 218 Mb in male mites. Conclusions This data provides a starting point for understanding the genetic organisation and evolution of these astigmatid mites, informing future sequencing projects. A comparitive genomic approach including these three closely related mites is likely to reveal key insights on mite biology, parasitic adaptations and immune evasion. PMID:22214472

  7. Identification of Bari Transposons in 23 Sequenced Drosophila Genomes Reveals Novel Structural Variants, MITEs and Horizontal Transfer.

    PubMed

    Palazzo, Antonio; Lovero, Domenica; D'Addabbo, Pietro; Caizzi, Ruggiero; Marsano, René Massimiliano

    2016-01-01

    Bari elements are members of the Tc1-mariner superfamily of DNA transposons, originally discovered in Drosophila melanogaster, and subsequently identified in silico in 11 sequenced Drosophila genomes and as experimentally isolated in four non-sequenced Drosophila species. Bari-like elements have been also studied for their mobility both in vivo and in vitro. We analyzed 23 Drosophila genomes and carried out a detailed characterization of the Bari elements identified, including those from the heterochromatic Bari1 cluster in D. melanogaster. We have annotated 401 copies of Bari elements classified either as putatively autonomous or inactive according to the structure of the terminal sequences and the presence of a complete transposase-coding region. Analyses of the integration sites revealed that Bari transposase prefers AT-rich sequences in which the TA target is cleaved and duplicated. Furthermore evaluation of transposon's co-occurrence near the integration sites of Bari elements showed a non-random distribution of other transposable elements. We also unveil the existence of a putatively autonomous Bari1 variant characterized by two identical long Terminal Inverted Repeats, in D. rhopaloa. In addition, we detected MITEs related to Bari transposons in 9 species. Phylogenetic analyses based on transposase gene and the terminal sequences confirmed that Bari-like elements are distributed into three subfamilies. A few inconsistencies in Bari phylogenetic tree with respect to the Drosophila species tree could be explained by the occurrence of horizontal transfer events as also suggested by the results of dS analyses. This study further clarifies the Bari transposon's evolutionary dynamics and increases our understanding on the Tc1-mariner elements' biology. PMID:27213270

  8. Identification of Bari Transposons in 23 Sequenced Drosophila Genomes Reveals Novel Structural Variants, MITEs and Horizontal Transfer

    PubMed Central

    D’Addabbo, Pietro; Caizzi, Ruggiero

    2016-01-01

    Bari elements are members of the Tc1-mariner superfamily of DNA transposons, originally discovered in Drosophila melanogaster, and subsequently identified in silico in 11 sequenced Drosophila genomes and as experimentally isolated in four non-sequenced Drosophila species. Bari-like elements have been also studied for their mobility both in vivo and in vitro. We analyzed 23 Drosophila genomes and carried out a detailed characterization of the Bari elements identified, including those from the heterochromatic Bari1 cluster in D. melanogaster. We have annotated 401 copies of Bari elements classified either as putatively autonomous or inactive according to the structure of the terminal sequences and the presence of a complete transposase-coding region. Analyses of the integration sites revealed that Bari transposase prefers AT-rich sequences in which the TA target is cleaved and duplicated. Furthermore evaluation of transposon’s co-occurrence near the integration sites of Bari elements showed a non-random distribution of other transposable elements. We also unveil the existence of a putatively autonomous Bari1 variant characterized by two identical long Terminal Inverted Repeats, in D. rhopaloa. In addition, we detected MITEs related to Bari transposons in 9 species. Phylogenetic analyses based on transposase gene and the terminal sequences confirmed that Bari-like elements are distributed into three subfamilies. A few inconsistencies in Bari phylogenetic tree with respect to the Drosophila species tree could be explained by the occurrence of horizontal transfer events as also suggested by the results of dS analyses. This study further clarifies the Bari transposon’s evolutionary dynamics and increases our understanding on the Tc1-mariner elements’ biology. PMID:27213270

  9. Demodex mites.

    PubMed

    Elston, Carly A; Elston, Dirk M

    2014-01-01

    Demodex mites are normal inhabitants of human hair follicles. D folliculorum is found predominantly in the follicular infundibulum of facial skin and is typically present in small groups. D brevis, the smaller of the two species, predominates on the trunk, typically as solitarily mites within the sebaceous glands and ducts. In a wide variety of animals, Demodex mites are recognized as a cause of mange. The role of Demodex mites as agents of human disease has been more controversial, but evidence favors their involvement in acneiform eruptions, folliculitis, and a range of eruptions in immunosuppressed patients. PMID:25441466

  10. Demodex mites.

    PubMed

    Elston, Carly A; Elston, Dirk M

    2014-01-01

    Demodex mites are normal inhabitants of human hair follicles. D folliculorum is found predominantly in the follicular infundibulum of facial skin and is typically present in small groups. D brevis, the smaller of the two species, predominates on the trunk, typically as solitarily mites within the sebaceous glands and ducts. In a wide variety of animals, Demodex mites are recognized as a cause of mange. The role of Demodex mites as agents of human disease has been more controversial, but evidence favors their involvement in acneiform eruptions, folliculitis, and a range of eruptions in immunosuppressed patients.

  11. The effects of inhaled corticosteroids on intrinsic responsiveness and histology of airways from infant monkeys exposed to house dust mite allergen and ozone

    SciTech Connect

    Joad, Jesse P. Kott, Kayleen S.; Bric, John M.; Schelegle, Edward S.; Gershwin, Laurel J.; Plopper, Charles G.; Peake, Janice L.; Pinkerton, Kent E.

    2008-01-15

    Inhaled corticosteroids (ICS) are recommended to treat infants with asthma, some with intermittent asthma. We previously showed that exposing infant monkeys to allergen/ozone resulted in asthma-like characteristics of their airways. We evaluated the effects of ICS on histology and intrinsic responsiveness of allergen/ozone-exposed and normal infant primate airways. Infant monkeys were exposed by inhalation to (1) filtered air and saline, (2) house dust mite allergen (HDMA) + ozone and saline, (3) filtered air and ICS (budesonide) or (4) HDMA + ozone and ICS. Allergen/ozone exposures started at 1 month and ICS at 3 months of age. At 6 months of age, methacholine-induced changes in luminal area of airways in proximal and distal lung slices were determined using videomicrometry, followed by histology of the same slices. Proximal airway responsiveness was increased by allergen/ozone and by ICS. Eosinophil profiles were increased by allergen/ozone in both proximal and distal airways, an effect that was decreased by ICS in distal airways. In both allergen/ozone- and air-exposed monkeys, ICS increased the number of alveolar attachments in distal airways, decreased mucin in proximal airways and decreased epithelial volume in both airways. ICS increased smooth muscle in air-exposed animals while decreasing it in allergen/ozone-exposed animals in both airways. In proximal airways, there was a small but significant positive correlation between smooth muscle and airway responsiveness, as well as between alveolar attachments and responsiveness. ICS change morphology and function in normal airways as well as allergen/ozone-exposed airways, suggesting that they should be reserved for infants with active symptoms.

  12. Airway inflammation and IgE production induced by dust mite allergen-specific memory/effector Th2 cell line can be effectively attenuated by IL-35.

    PubMed

    Huang, Chiung-Hui; Loo, Evelyn Xiu-Ling; Kuo, I-Chun; Soh, Gim Hooi; Goh, Denise Li-Meng; Lee, Bee Wah; Chua, Kaw Yan

    2011-07-01

    CD4(+) memory/effector T cells play a central role in orchestrating the rapid and robust immune responses upon re-encounter with specific Ags. However, the immunologic mechanism(s) underlying these responses are still not fully understood. To investigate this, we generated an allergen (major house dust mite allergen, Blo t 5)-specific murine Th2 cell line that secreted IL-4, IL-5, IL-10, and IL-13, but not IL-9 or TNF-α, upon activation by the cognate Ag. These cells also exhibited CD44(high)CD62L(-) and CD127(+) (IL-7Rα(+)) phenotypes, which are characteristics of memory/effector T cells. Experiments involving adoptive transfer of this Th2 cell line in mice, followed by three intranasal challenges with Blo t 5, induced a dexamethasone-sensitive eosinophilic airway inflammation. This was accompanied by elevation of Th2 cytokines and CC- and CXC-motif chemokines, as well as recruitment of lymphocytes and polymorphic mononuclear cells into the lungs. Moreover, Blo t 5-specific IgE was detected 4 d after the last intranasal challenge, whereas elevation of Blo t 5-specific IgG1 was found at week two. Finally, pulmonary delivery of the pVAX-IL-35 DNA construct effectively downregulated Blo t 5-specific allergic airway inflammation, and i.m. injection of pVAX-IL-35 led to long-lasting suppression of circulating Blo t 5-specific and total IgE. This model provides a robust research tool to elucidate the immunopathogenic role of memory/effector Th2 cells in allergic airway inflammation. Our results suggested that IL-35 could be a potential therapeutic target for allergic asthma through its attenuating effects on allergen-specific CD4(+) memory/effector Th2 cell-mediated airway inflammation.

  13. Interleukin-33 from Monocytes Recruited to the Lung Contributes to House Dust Mite-Induced Airway Inflammation in a Mouse Model

    PubMed Central

    Tashiro, Hiroki; Takahashi, Koichiro; Hayashi, Shinichiro; Kato, Go; Kurata, Keigo; Kimura, Shinya; Sueoka-Aragane, Naoko

    2016-01-01

    Background Interleukin-33 (IL-33) activates group 2 innate lymphoid cells (ILC2), resulting in T-helper-2 inflammation in bronchial asthma. Airway epithelial cells were reported as sources of IL-33 during apoptosis and necrosis. However, IL-33 is known to be from sources other than airway epithelial cells such as leukocytes, and the mechanisms of IL-33 production and release are not fully understood. The aim of this study was to clarify the role of IL-33 production by monocytes in airway inflammation. Methods BALB/c mice were sensitized and challenged with a house dust mite (HDM) preparation. Airway inflammation was assessed by quantifying inflammatory cells in bronchoalveolar lavage (BAL) fluid, and IL-25, IL-33, and thymic stromal lymphopoietin (TSLP) levels in lung. Immunohistochemistry for IL-33 in lung sections was also performed. Ly6c, CD11b, and CD11c expression was examined by flow cytometry. Clodronate liposomes were used in the HDM-airway inflammation model to deplete circulating monocytes. Results The IL-33, but not IL-25 or TSLP, level in lung homogenates was markedly increased in HDM mice compared to control mice. IL-33-positive cells in the lungs were identified using immunohistochemistry and were increased in areas surrounding bronchi and vasculature. Furthermore, IL-33 levels were increased in mononuclear cells derived from lungs of HDM mice compared to controls. The expression of Ly6c in mononuclear cells was significantly higher in HDM mice than in controls. Treatment with clodronate liposomes led to inhibition of not only inflammatory cells in BAL fluid, airway hyper reactivity and Th2 cytokines in lung, but also IL-33 in lung. Conclusion IL-33 from monocytes recruited to the lung may contribute to the pathogenesis of HDM-induced airway inflammation. PMID:27310495

  14. Long-term falls in antibodies to dust mite and pollen allergens in patients with asthma or hay fever.

    PubMed

    Rawle, F C; Burr, M L; Platts-Mills, T A

    1983-09-01

    'Spontaneous' improvement in, or alteration of, allergic symptoms is a common occurrence, and the immunological basis is of interest in attempts to develop effective specific therapy. In the present study we measured levels of serum antibodies to Dermatophagoides pteronyssinus in patients diagnosed as having house-dust-allergic asthma up to 40 years previously. The results show a progressive fall in both IgG and IgE antibodies to antigen P1 and RAST binding to crude D. pteronyssinus extract. By contrast changes in total serum IgE were not marked. Within each of the groups of patients diagnosed 20, 30 and 40 years previously, 70% no longer suffered severe symptoms. However, the absence of detectable IgE antibody in serum was neither a necessary nor a sufficient condition for loss of symptoms. A group of patients who had spontaneously recovered from hay fever had significantly lower IgG and IgE antibody for the major grass pollen allergen Rye I and also lower total IgE than current hay fever sufferers. In neither hay fever nor asthma was there evidence to link spontaneous improvement in symptoms with an increase in IgG antibodies.

  15. Observations on the micromorphology of the tropical rat mite Ornithonyssus bacoti (Hirst) as revealed by scanning electron microscopy.

    PubMed

    Green, E D; Baker, C

    1996-09-01

    Ornithonyssus bacoti (Hirst) is an important parasite of rodents. The characteristic shape of the dorsal and sternal shields and gnathosoma used as taxonomic characteristics was confirmed by scanning electron microscopy. The anal plate is distinctly pear-shaped with a pair of adanal setae lateral to the anal valves, a single postanal seta and a distinct dentate cribrum formed by peg-like projections. In the adult mites a peritreme extends anteriorly to the 1st coxa from the spiracle situated laterally between the 3rd and 4th coxa. The peritreme is an open canal protected by an overhanging dorsal ridge and lined with short peg-like aciculae. The gnathosoma includes a pair of pedipalps, a pair of protrusile chelicerae retracted into the hypostoma, and a serrate tritosternum ventrally. A unique feature to the normal setae of the pedipalps is a golf club-shaped seta which is found medially on the palp genu. A distinctive double-bladed 'palpal claw' or apotele is directed medially from the palp tibia. The pincer-like chela consists of a spear-like prong forming the moveable digit and a curved stylus-like fixed digit used to pierce the skin. Each leg ends with a pair of hooked tarsal claws and a pair of lateral comblike pretarsal appendages adjacent to the pulvillus. The pulvillus may be retracted, allowing the pretarsal operculum to function as a 'clasping organ' that enables the mite to clasp the hairs of the host during feeding. PMID:9120855

  16. Screening of spider mites (Acari: Tetranychidae) for reproductive endosymbionts reveals links between co-infection and evolutionary history.

    PubMed

    Zhang, Yan-Kai; Chen, Ya-Ting; Yang, Kun; Qiao, Ge-Xia; Hong, Xiao-Yue

    2016-01-01

    Reproductive endosymbionts have been shown to have wide-ranging effects on many aspects of their hosts' biology. A first step to understanding how these endosymbionts interact with their hosts is to determine their incidences. Here, we screened for four reproductive endosymbionts (Wolbachia, Cardinium, Spiroplasma and Rickettsia) in 28 populations of spider mites (Acari: Tetranychidae) representing 12 species. Each of the four endosymbionts were identified in at least some of the tested specimens, and their infection patterns showed variations at the species-level and population-level, suggesting their distributions can be correlated with both the phylogeny and ecology of the hosts. Co-infections of unrelated bacteria, especially double infections of Wolbachia and Cardinium within the same individuals were common. Spiroplasma and Rickettsia infections were specific to particular host species, respectively. Further, the evolutionary histories of these endosymbionts were inferred by comparing the phylogenies of them and their hosts. These findings can help to clarify the interactions between endosymbionts and arthropods.

  17. Screening of spider mites (Acari: Tetranychidae) for reproductive endosymbionts reveals links between co-infection and evolutionary history.

    PubMed

    Zhang, Yan-Kai; Chen, Ya-Ting; Yang, Kun; Qiao, Ge-Xia; Hong, Xiao-Yue

    2016-01-01

    Reproductive endosymbionts have been shown to have wide-ranging effects on many aspects of their hosts' biology. A first step to understanding how these endosymbionts interact with their hosts is to determine their incidences. Here, we screened for four reproductive endosymbionts (Wolbachia, Cardinium, Spiroplasma and Rickettsia) in 28 populations of spider mites (Acari: Tetranychidae) representing 12 species. Each of the four endosymbionts were identified in at least some of the tested specimens, and their infection patterns showed variations at the species-level and population-level, suggesting their distributions can be correlated with both the phylogeny and ecology of the hosts. Co-infections of unrelated bacteria, especially double infections of Wolbachia and Cardinium within the same individuals were common. Spiroplasma and Rickettsia infections were specific to particular host species, respectively. Further, the evolutionary histories of these endosymbionts were inferred by comparing the phylogenies of them and their hosts. These findings can help to clarify the interactions between endosymbionts and arthropods. PMID:27291078

  18. Screening of spider mites (Acari: Tetranychidae) for reproductive endosymbionts reveals links between co-infection and evolutionary history

    PubMed Central

    Zhang, Yan-Kai; Chen, Ya-Ting; Yang, Kun; Qiao, Ge-Xia; Hong, Xiao-Yue

    2016-01-01

    Reproductive endosymbionts have been shown to have wide-ranging effects on many aspects of their hosts’ biology. A first step to understanding how these endosymbionts interact with their hosts is to determine their incidences. Here, we screened for four reproductive endosymbionts (Wolbachia, Cardinium, Spiroplasma and Rickettsia) in 28 populations of spider mites (Acari: Tetranychidae) representing 12 species. Each of the four endosymbionts were identified in at least some of the tested specimens, and their infection patterns showed variations at the species-level and population-level, suggesting their distributions can be correlated with both the phylogeny and ecology of the hosts. Co-infections of unrelated bacteria, especially double infections of Wolbachia and Cardinium within the same individuals were common. Spiroplasma and Rickettsia infections were specific to particular host species, respectively. Further, the evolutionary histories of these endosymbionts were inferred by comparing the phylogenies of them and their hosts. These findings can help to clarify the interactions between endosymbionts and arthropods. PMID:27291078

  19. Revealing the structure and dust content of debris disks on solar systems scales with GPI

    NASA Astrophysics Data System (ADS)

    Duchene, Gaspard; Fitzgerald, Michael P.; Kalas, Paul; Graham, James R.; Arriaga, Pauline; Bruzzone, Sebastian; Chen, Christine; Dawson, Rebekah Ilene; Dong, Ruobing; Draper, Zachary; Esposito, Thomas; Follette, Katherine; Hung, Li-Wei; Lawler, Samantha; Metchev, Stanimir; Millar-Blanchaer, Max; Murray-Clay, Ruth; Perrin, Marshall D.; Rameau, Julien; Wang, Jason; Wolff, Schuyler; Macintosh, Bruce; GPIES Team

    2016-01-01

    High contrast scattered light images offer the best prospect to assess the detailed geometry and structure of dusty debris disks. In turn, such images can yield profound insight on the architecture of the underlying planetary system as dust grains respond to the gravitational pull of planetary bodies. A new generation of extreme adaptive optics systems now enables an unprecedented exploration of circumstellar disks on solar system scales. Here we review the new science derived from over a dozen debris disks imaged with the Gemini Planet Imager (GPI) as part of the GPI Exoplanet Survey (GPIES). In addition to its exquisite imaging capability, GPI's polarimetric mode provides invaluable insight on the dust content of each disk, in most cases for the very first time. These early results typically reveal narrow belts of material with evacuated regions roughly 50-100 AU in radius, subtle asymmetries in structure and high degree of linear polarization. We will provide an overview of the disk observations made during the GPIES campaign to date and will discuss in more detail some of the most remarkable systems.This work is supported by grants NSF AST-0909188, -1411868, -1413718; NASA NNX-15AD95G, -14AJ80G, -11AD21G; and the NExSS research network.

  20. Fusarium semitectum, a potential mycopathogen against thrips and mites in chilli, Capsicum annuum.

    PubMed

    Mikunthan, G; Manjunatha, M

    2006-01-01

    . Fusarium formulation sprayed plots were recorded low damage index than NSKE, water sprayed plots including control. Oil-emulsion formulation treated plot adjusted the highest benefit cost ratio of 6.07:1. Oil emulsion formulation (refined sunflower oil-Safola) was next best to the dust water formulation of F. semitectum. and monocrotophos combination and more-over equal to the monocrotophos 0.05% alone in suppressing the thrips and mite population. These results revealed that dust water formulation in combination with monocrotophos (0.05%) was able to suppress the population of thrips and mites and thus was able to give highest dry chilli yield. Oil emulsion formulation of F. semitectum can also be used as the next best choice in an environment friendly integrated chilli pest management programme. PMID:17385513

  1. Profiles of IgE Sensitization to Der f 1, Der f 2, Der f 6, Der f 8, Der f 10, and Der f 20 in Korean House Dust Mite Allergy Patients

    PubMed Central

    Jeong, Kyoung Yong; Lee, June Yong; Son, Mina; Yi, Myung-hee; Yong, Tai-Soon; Shin, Jung U; Lee, Kwang Hoon; Kim, Yoon-Ju; Park, Kyung Hee; Park, Hye Jung; Lee, Jae-Hyun

    2015-01-01

    Purpose Measurement of IgE specific to purified house dust mite (HDM) allergens may improve allergy diagnosis. This study aimed to investigate the sensitization profiles of Korean HDM allergic subjects suffering from respiratory allergy and atopic dermatitis (AD) to Der f 1, Der f 2, Der f 6, Der f 8, Der f 10, and Der f 20. Methods Recombinant HDM allergens were produced in Pichia pastoris (Der f 1) or Escherichia coli (5 allergens). IgE reactivity to the individual recombinant allergens and total extract of mite was assessed by ELISA. Results Der f 1 was recognized by 79.1%, Der f 2 by 79.1%, Der f 6 by 9.3%, Der f 8 by 6.2%, Der f 10 by 6.2%, and Der f 20 by 6.6% of the patients' sera tested, while the prevalence of IgE reactivity to total mite extract was 94.7%. Combination of Der f 1 and Der f 2 had a sensitivity of 87.6%. Specific IgE to Der f 2 alone was detected from 89.4% of HDM-sensitized respiratory allergy subjects and 92.3% to the combination of the 2 major allergens Der f 1 and Der f 2. However, sera from fewer patients with AD, namely 72.4% and 71.0%, recognized Der f 1 and Der f 2, respectively. The combination of 2 major allergens allowed diagnosis of 84.5% of the AD patients. No correlation between sensitization to specific allergens and HDM allergy entity was found. Conclusions Der f 2 was the most frequently sensitized allergen among the HDM-sensitized respiratory and AD patients in Korea, and the combination of the group 1 and 2 major allergens increased the diagnostic sensitivity. Minor allergens did not significantly improve diagnostic sensitivity. However, further studies are needed to analyze the relationship between sensitization to other HDM allergens and the disease entity of the HDM allergy. PMID:25749773

  2. Crystal Structures of Mite Allergens Der f 1 and Der p 1 Reveal Differences in Surface-Exposed Residues that May Influence Antibody Binding

    SciTech Connect

    Chruszcz, Maksymilian; Chapman, Martin D.; Vailes, Lisa D.; Stura, Enrico A.; Saint-Remy, Jean-Marie; Minor, Wladek; Pomés, Anna

    2009-12-01

    The Group 1 mite allergens, Der f 1 and Der p 1, are potent allergens excreted by Dermatophagoides farinae and Dermatophagoides pteronyssinus, respectively. The human IgE antibody responses to the Group 1 allergens show more cross-reactivity than the murine IgG antibody responses which are largely species-specific. Here, we report the crystal structure of the mature form of Der f 1, which was isolated from its natural source, and a new, high-resolution structure of mature recombinant Der p 1. Unlike Der p 1, Der f 1 is monomeric both in the crystalline state and in solution. Moreover, no metal binding is observed in the structure of Der f 1, despite the fact that all amino acids involved in Ca{sup 2+} binding in Der p 1 are completely conserved in Der f 1. Although Der p 1 and Der f 1 share extensive sequence identity, comparison of the crystal structures of both allergens revealed structural features which could explain the differences in murine and human IgE antibody responses to these allergens. There are structural differences between Der f 1 and Der p 1 which are unevenly distributed on the allergens' surfaces. This uneven spatial arrangement of conserved versus altered residues could explain both the specificity and cross-reactivity of antibodies against Der f 1 and Der p 1.

  3. Lack of cross-reactivity between the Bacillus thuringiensis derived protein Cry1F in maize grain and dust mite Der p7 protein with human sera positive for Der p7-IgE.

    PubMed

    Ladics, Gregory S; Bardina, Luda; Cressman, Robert F; Mattsson, Joel L; Sampson, Hugh A

    2006-03-01

    Cry1F protein, derived from Bacillus thuringiensis, is effective at controlling lepidopteran pests and a synthetic Cry1F transgene was transferred into maize. For the safety assessment of genetically modified food crops, the allergenic potential of the introduced novel trait(s) is evaluated. Because no single parameter is currently predictive of allergic potential, a 'weight of evidence' approach has been proposed. As part of this assessment, the amino acid (aa) sequence of the Cry1F protein was compared to a database of known allergens using recommended criteria. The Cry1F protein did not show significant similarity or a match of eight contiguous identical aa with any allergen. However, a single six contiguous aa match was identified between Cry1F and the Der p7 protein of the dust mite, Dermatophagoides pteronyssinus. To investigate whether Cry1F was cross-reactive with Der p7, sera from 10 dust mite allergic patients containing Der p 7-specific IgE antibody were used to compare IgE-specific binding. No evidence of cross-reactivity was observed between Cry1F and Der p7. This study provides in vitro IgE sera screening data, that when considered in the context of other bioinformatic data [Hileman R.E., Silvanovich, A., Goodman R.E., Rice E.A., Holleschak G., Astwood J.D., Hefle S.L., 2002. Bioinformatic methods for allergenicity assessment using a comprehensive allergen database. Int. Arch. Allergy Immunol. 128, 280-291; Stadler, M.B., Stadler, B.M., 2003. Allergenicity prediction by protein sequence. FASEB J. 17, 1141-1143.], adds further evidence arguing against the use of a six contiguous identical amino acid search to identify potential cross-reactive allergens. Cry1F is heat labile, rapidly hydrolyzed in an in vitro pepsin resistance assay, not glycosylated and not from an allergenic source. Taken together, these data indicate a lack of allergenic concern for Cry1F.

  4. Topical application of a novel ceramide derivative, K6PC-9, inhibits dust mite extract-induced atopic dermatitis-like skin lesions in NC/Nga mice.

    PubMed

    Kang, Jong Soon; Youm, Jong-Kyung; Jeong, Se Kyoo; Park, Byeong Deog; Yoon, Won Kee; Han, Mi Hwa; Lee, Hyunju; Han, Sang-Bae; Lee, Kiho; Park, Song-Kyu; Lee, Seung Hun; Yang, Kyu-Hwan; Moon, Eun-Yi; Kim, Hwan Mook

    2007-12-15

    Atopic dermatitis (AD) is a chronic inflammatory skin disease. K6PC-9 (N-Ethanol-2-hexyl-3-oxo-decanamide) is a novel synthetic ceramide derivative of PC-9S (N-Ethanol-2-mirystyl-3-oxo-stearamide), which was known to be effective in atopic and psoriatic patients. To investigate the immunomodulatory activity of K6PC-9, we examined the effect of K6PC-9 on T lymphocyte and macrophage function and the effect of topical application of K6PC-9 on skin inflammation and AD-like skin lesions in mouse models. K6PC-9 had no effect on concanavalin A-induced proliferation, interleukin (IL)-2 secretion and IL-4 secretion in mouse splenocytes. In contrast, lipopolysaccharide-induced nitrite generation was potently suppressed by K6PC-9 in mouse peritoneal macrophages. In mouse model of skin inflammation, K6PC-9 inhibited phorbol ester-induced increase in ear thickness and expression of tumor necrosis factor-alpha in the ear of BALB/c mice. Topical application of K6PC-9 also suppressed mite extract-induced AD-like skin lesions in NC/Nga mice. Increase in ear thickness was significantly inhibited by K6PC-9 in this model. K6PC-9 also blocked the infiltration of mast cells and neutrophils into the ear. Further study demonstrated that the mRNA expression of tumor necrosis factor-alpha and adhesion molecules, such as vascular cell adhesion molecule-1, intercellular adhesion molecule-1, E-selectin, was also suppressed by K6PC-9 in the ear of mite extract-treated NC/Nga mice. Taken together, the results presented in this report show that K6PC-9 has an anti-inflammatory potential and exerts beneficial effects in an animal model of AD, indicating that K6PC-9 might be used as a topical agent for the treatment of AD.

  5. High Redshift Dust Obscured Galaxies, A Morphology-SED Connection Revealed by Keck Adaptive Optics Imaging

    NASA Astrophysics Data System (ADS)

    Melbourne, Jason

    2009-01-01

    Keck Adaptive Optics (AO) K'-band images reveal the morphologies of 15 high redshift (z 2) dust obscured galaxies (DOGs). DOGs are defined by an optical to mid-IR color of fν(24) / fν(R) > 1000, redder than Arp 220 at any redshift. With ultra-luminous infrared luminosities, DOGs are thought to be powered by a combination of AGN and star formation. We use high spatial resolution (0.5 - 1 kpc at these redshifts) AO images to help disentangle the dominant energy source in each DOG and to look for triggers, such as evidence of ongoing mergers. We find evidence for ongoing merging in 10-20% of the sample. We also find a statistically significant correlation between galaxy compactness and 24 micron flux (luminosity), with the brightest DOGs exhibiting more compact morphologies than fainter DOGs. The most diffuse systems tend to show a 1.6 micron stellar bump in their spectral energy distributions redshifted to the Spitzer IRAC bands (4.5 - 8.0 microns). The imaging results lend further support to the idea that the highest luminosity DOGs are AGN dominated (resulting in compact morphology), while the lower luminosity, diffuse, DOGs tend to be star formation dominated.

  6. Diversity of feather mites (Acari: Astigmata) on Darwin's finches.

    PubMed

    Villa, Scott M; Le Bohec, Céline; Koop, Jennifer A H; Proctor, Heather C; Clayton, Dale H

    2013-10-01

    Feather mites are a diverse group of ectosymbionts that occur on most species of birds. Although Darwin's finches are a well-studied group of birds, relatively little is known about their feather mites. Nearly 200 birds across 9 finch species, and from 2 locations on Santa Cruz Island, Galápagos, were dust-ruffled during the 2009 breeding season. We found 8 genera of feather mites; the most prevalent genus was Mesalgoides (53-55%), followed by Trouessartia (40-45%), Amerodectes and Proctophyllodes (26-33%), Xolalgoides (21-27%), Analges and Strelkoviacarus (0-6%), and Dermoglyphus (2-4%). There was no evidence for microclimatic effects (ambient temperature and relative humidity) on mite diversity. Host body mass was significantly correlated with mean feather mite abundance across 7 of 8 well-sampled species of finches. Certhidea olivacea, the smallest species, did not fit this pattern and had a disproportionately high number of mites for its body mass.

  7. Intestinal proteases of free-living and parasitic astigmatid mites.

    PubMed

    Holt, Deborah C; Burgess, Stewart T G; Reynolds, Simone L; Mahmood, Wajahat; Fischer, Katja

    2013-02-01

    Among arthropod pests, mites are responsible for considerable damage to crops, humans and other animals. However, detailed physiological data on these organisms remain sparse, mainly because of their small size but possibly also because of their extreme diversity. Focusing on intestinal proteases, we draw together information from three distinct mite species that all feed on skin but have separately adapted to a free-living, a strictly ecto-parasitic and a parasitic lifestyle. A wide range of studies involving immunohistology, molecular biology, X-ray crystallography and enzyme biochemistry of mite gut proteases suggests that these creatures have diverged considerably as house dust mites, sheep scab mites and scabies mites. Each species has evolved a particular variation of a presumably ancestral repertoire of digestive enzymes that have become specifically adapted to their individual environmental requirements.

  8. Astronomer's new guide to the galaxy: largest map of cold dust revealed

    NASA Astrophysics Data System (ADS)

    2009-07-01

    -wave camera on the ESO-operated APEX telescope. APEX is located at an altitude of 5100 m on the arid plateau of Chajnantor in the Chilean Andes -- a site that allows optimal viewing in the submillimetre range. The Universe is relatively unexplored at submillimetre wavelengths, as extremely dry atmospheric conditions and advanced detector technology are required for such observations. The interstellar medium -- the material between the stars -- is composed of gas and grains of cosmic dust, rather like fine sand or soot. However, the gas is mostly hydrogen and relatively difficult to detect, so astronomers often search for these dense regions by looking for the faint heat glow of the cosmic dust grains. Submillimetre light allows astronomers to see these dust clouds shining, even though they obscure our view of the Universe at visible light wavelengths. Accordingly, the ATLASGAL map includes the denser central regions of our galaxy, in the direction of the constellation of Sagittarius -- home to a supermassive black hole (ESO 46/08) -- that are otherwise hidden behind a dark shroud of dust clouds. The newly released map also reveals thousands of dense dust clumps, many never seen before, which mark the future birthplaces of massive stars. The clumps are typically a couple of light-years in size, and have masses of between ten and a few thousand times the mass of our Sun. In addition, ATLASGAL has captured images of beautiful filamentary structures and bubbles in the interstellar medium, blown by supernovae and the winds of bright stars. Some striking highlights of the map include the centre of the Milky Way, the nearby massive and dense cloud of molecular gas called Sagittarius B2, and a bubble of expanding gas called RCW120, where the interstellar medium around the bubble is collapsing and forming new stars (see ESO 40/08). "It's exciting to get our first look at ATLASGAL, and we will be increasing the size of the map over the next year to cover all of the galactic plane

  9. Genome-Wide Analysis of Stowaway-Like MITEs in Wheat Reveals High Sequence Conservation, Gene Association, and Genomic Diversification1[C][W

    PubMed Central

    Yaakov, Beery; Ben-David, Smadar; Kashkush, Khalil

    2013-01-01

    The diversity and evolution of wheat (Triticum-Aegilops group) genomes is determined, in part, by the activity of transposable elements that constitute a large fraction of the genome (up to 90%). In this study, we retrieved sequences from publicly available wheat databases, including a 454-pyrosequencing database, and analyzed 18,217 insertions of 18 Stowaway-like miniature inverted-repeat transposable element (MITE) families previously characterized in wheat that together account for approximately 1.3 Mb of sequence. All 18 families showed high conservation in length, sequence, and target site preference. Furthermore, approximately 55% of the elements were inserted in transcribed regions, into or near known wheat genes. Notably, we observed significant correlation between the mean length of the MITEs and their copy number. In addition, the genomic composition of nine MITE families was studied by real-time quantitative polymerase chain reaction analysis in 40 accessions of Triticum spp. and Aegilops spp., including diploids, tetraploids, and hexaploids. The quantitative polymerase chain reaction data showed massive and significant intraspecific and interspecific variation as well as genome-specific proliferation and nonadditive quantities in the polyploids. We also observed significant differences in the methylation status of the insertion sites among MITE families. Our data thus suggest a possible role for MITEs in generating genome diversification and in the establishment of nascent polyploid species in wheat. PMID:23104862

  10. The effect of house dust mite sensitization on lung size and airway caliber in symptomatic and nonsymptomatic preadolescent children: a community-based study in Poland.

    PubMed Central

    Jedrychowski, Wieslaw; Maugeri, Umberto; Jedrychowska-Bianchi, Iwona; Mróz, Elzbieta

    2002-01-01

    There are conflicting reports on the effects of atopy on lung function. The purpose of this study was to compare the effects of house mite (HM) atopy on lung function in subsamples of 12-year-old symptomatic and nonsymptomatic preadolescent children taken from the community sample. An additional objective of this study was to identify possible environmental determinants of HM skin reaction. We obtained questionnaire data on respiratory symptoms and skin-prick tests and performed spirometry on a subsample of 311 children of a birth cohort of children who have been followed over 3 years. Multivariate regression analysis showed progressive decrement of lung function indices (forced vital capacity, forced expiratory volume in 1 sec, and forced expiratory flow, midexpiratory phase) with increasing degree of HM atopy reflected by the skin reaction to HM allergens. The apparent association between the level of HM atopy and the lung function indices was highly significant in symptomatic individuals but insignificant in nonsymptomatic subjects. HM sensitization was significantly associated with mother's atopy. It occurred predominantly in boys and was related to the use of coal or gas for house heating. The effect of allergen sensitization on lung size and airway caliber confined to symptomatic subjects may reflect the inflammatory status of bronchial airways in the symptomatic subjects. PMID:12055047

  11. Dust Production and Particle Acceleration in Supernova 1987A Revealed with ALMA

    NASA Technical Reports Server (NTRS)

    Indebetouw, R.; Matsuura, M.; Dwek, E.; Zanardo, G.; Barlow, M. J.; Baes, M.; Bouchet, P.; Burrows, D. N.; Chevalier, R.; Clayton, G. C.; Fransson, C.; Gaensler, B.; Kirshner, R.; Lakicevic, M.; Long, K. S.; Lundqvist, P.; Marti-Vidal, I.; Marcaide, J.; McCray, R.; Meixner, M.; Ng, C.-Y.; Park, S.; Sonneborn, G.; Staveley-Smith, L.; vanLoon, J.

    2014-01-01

    Supernova (SN) explosions are crucial engines driving the evolution of galaxies by shock heating gas, increasing the metallicity, creating dust, and accelerating energetic particles. In 2012 we used the Atacama Large Millimeter/ Submillimeter Array to observe SN1987A, one of the best-observed supernovae since the invention of the telescope. We present spatially resolved images at 450 µm, 870 µm, 1.4 mm, and 2.8 mm, an important transition wavelength range. Longer wavelength emission is dominated by synchrotron radiation from shock-accelerated particles, shorter wavelengths by emission from the largest mass of dust measured in a supernova remnant (>0.2 Solar Mass). For the first time we show unambiguously that this dust has formed in the inner ejecta (the cold remnants of the exploded star's core). The dust emission is concentrated at the center of the remnant, so the dust has not yet been affected by the shocks. If a significant fraction survives, and if SN 1987A is typical, supernovae are important cosmological dust producers.

  12. DUST PRODUCTION AND PARTICLE ACCELERATION IN SUPERNOVA 1987A REVEALED WITH ALMA

    SciTech Connect

    Indebetouw, R.; Chevalier, R.; Matsuura, M.; Barlow, M. J.; Dwek, E.; Zanardo, G.; Baes, M.; Bouchet, P.; Burrows, D. N.; Clayton, G. C.; Fransson, C.; Lundqvist, P.; Gaensler, B.; Kirshner, R.; Lakićević, M.; Long, K. S.; Meixner, M.; Martí-Vidal, I.; Marcaide, J.; and others

    2014-02-10

    Supernova (SN) explosions are crucial engines driving the evolution of galaxies by shock heating gas, increasing the metallicity, creating dust, and accelerating energetic particles. In 2012 we used the Atacama Large Millimeter/Submillimeter Array to observe SN 1987A, one of the best-observed supernovae since the invention of the telescope. We present spatially resolved images at 450 μm, 870 μm, 1.4 mm, and 2.8 mm, an important transition wavelength range. Longer wavelength emission is dominated by synchrotron radiation from shock-accelerated particles, shorter wavelengths by emission from the largest mass of dust measured in a supernova remnant (>0.2 M {sub ☉}). For the first time we show unambiguously that this dust has formed in the inner ejecta (the cold remnants of the exploded star's core). The dust emission is concentrated at the center of the remnant, so the dust has not yet been affected by the shocks. If a significant fraction survives, and if SN 1987A is typical, supernovae are important cosmological dust producers.

  13. EXTREME DUST DISKS IN Arp 220 AS REVEALED BY ALMA

    SciTech Connect

    Wilson, C. D.; Rangwala, N.; Glenn, J.; Maloney, P. R.; Spinoglio, L.; Pereira-Santaella, M.

    2014-07-10

    We present new images of Arp 220 from the Atacama Large Millimeter/submillimeter Array with the highest combination of frequency (691 GHz) and resolution (0.''36 × 0.''20) ever obtained for this prototypical ultraluminous infrared galaxy. The western nucleus is revealed to contain warm (200 K) dust that is optically thick (τ{sub 434} {sub μm} = 5.3), while the eastern nucleus is cooler (80 K) and somewhat less opaque (τ{sub 434} {sub μm} = 1.7). We derive full width at half-maximum diameters of 76 × ≤ 70 pc and 123 × 79 pc for the western and eastern nucleus, respectively. The two nuclei combined account for (83{sub −38}{sup +65} (calibration) {sub −34}{sup +0} (systematic))% of the total infrared luminosity of Arp 220. The luminosity surface density of the western nucleus (log (σT{sup 4})=14.3±0.2{sub −0.7}{sup +0} in units of L {sub ☉} kpc{sup –2}) appears sufficiently high to require the presence of an active galactic nucleus (AGN) or a ''hot starburst'', although the exact value depends sensitively on the brightness distribution adopted for the source. Although the role of any central AGN remains open, the inferred mean gas column densities of (0.6-1.8) × 10{sup 25} cm{sup –2} mean that any AGN in Arp 220 must be Compton-thick.

  14. Sensitization of Children to Storage Mites in Kutahya, Turkey

    PubMed Central

    Soyucen, Erdogan

    2009-01-01

    Specific IgE against Acarus siro, Glycphagus domesticus, Tyrophagus putrescentiae, and Lepidoglyphus destructor have been investigated by ELISA in sera of 92 children. Of them, 41 were found to be specific IgE positive (≥ 0.35 IU/ml) against at least one of house dust mite species, Dermatophagoides pteronyssinus and Dermatophagoides farinae, by an immunoblot. In 65.9% of the dust mite-sensitized children, specific IgE against at least one of these mite species was found. Sensitization levels, including co-sensitization cases were found to be 35.7% against A. siro, 24.4% against T. putrescentiae, 31.7% against L. destructor, and 26.8% against G. domesticus. In non-sensitized children, dust mite sensitization level was found to be 25.5%. Breakdown of sensitization by individual species in this group was; against A. siro and T. putrescentiae at 7.8%, against L. destructor at 13.7%, and against G. domesticus at 9.8%. When all children were reckoned, 43.5% was found to be sensitized against at least one storage mite species, with sensitizations against A. siro at 18.5%, T. putrescentiae at 26.1%, L. destructor at 21.7%, and G. domesticus at 17.4%. In dust samples collected from the dwellings of children, distribution of species was found to be A. siro (17%), G. domesticus (23%), T. putrescentiae (29%), L. destructor (25%), and unidentified (6%). In Fisher's chi-square test on SPSS program, there was a relationship between dust mite sensitization and storage mite sensitization (P < 0.05), but no meaningful relationship was found on the basis of individual mite species. PMID:19967087

  15. QUANTITATIVE PCR ANALYSIS OF HOUSE DUST CAN REVEAL ABNORMAL MOLD CONDITIONS

    EPA Science Inventory

    Indoor mold populations were measured in the dust of homes in Cleveland and Cincinnati, OH, by quantitative PCR (QPCR) and, in Cincinnati, also by culturing. QPCR assays for 82 species (or groups of species) were used to identify and quantify indoor mold populations in moldy home...

  16. Fine-Scale Linkage Mapping Reveals a Small Set of Candidate Genes Influencing Honey Bee Grooming Behavior in Response to Varroa Mites

    PubMed Central

    Arechavaleta-Velasco, Miguel E.; Alcala-Escamilla, Karla; Robles-Rios, Carlos; Tsuruda, Jennifer M.; Hunt, Greg J.

    2012-01-01

    Populations of honey bees in North America have been experiencing high annual colony mortality for 15–20 years. Many apicultural researchers believe that introduced parasites called Varroa mites (V. destructor) are the most important factor in colony deaths. One important resistance mechanism that limits mite population growth in colonies is the ability of some lines of honey bees to groom mites from their bodies. To search for genes influencing this trait, we used an Illumina Bead Station genotyping array to determine the genotypes of several hundred worker bees at over a thousand single-nucleotide polymorphisms in a family that was apparently segregating for alleles influencing this behavior. Linkage analyses provided a genetic map with 1,313 markers anchored to genome sequence. Genotypes were analyzed for association with grooming behavior, measured as the time that individual bees took to initiate grooming after mites were placed on their thoraces. Quantitative-trait-locus interval mapping identified a single chromosomal region that was significant at the chromosome-wide level (p<0.05) on chromosome 5 with a LOD score of 2.72. The 95% confidence interval for quantitative trait locus location contained only 27 genes (honey bee official gene annotation set 2) including Atlastin, Ataxin and Neurexin-1 (AmNrx1), which have potential neurodevelopmental and behavioral effects. Atlastin and Ataxin homologs are associated with neurological diseases in humans. AmNrx1 codes for a presynaptic protein with many alternatively spliced isoforms. Neurexin-1 influences the growth, maintenance and maturation of synapses in the brain, as well as the type of receptors most prominent within synapses. Neurexin-1 has also been associated with autism spectrum disorder and schizophrenia in humans, and self-grooming behavior in mice. PMID:23133594

  17. Quantitative PCR analysis of house dust can reveal abnormal mold conditions†

    PubMed Central

    Meklin, Teija; Haugland, Richard A.; Reponen, Tiina; Varma, Manju; Lummus, Zana; Bernstein, David; Wymer, Larry J.; Vesper, Stephen J.

    2007-01-01

    Indoor mold concentrations were measured in the dust of moldy homes (MH) and reference homes (RH) by quantitative PCR (QPCR) assays for 82 species or related groups of species (assay groups). About 70% of the species and groups were never or only rarely detected. The ratios (MH geometric mean : RH geometric mean) for 6 commonly detected species (Aspergillus ochraceus, A. penicillioides, A. unguis, A. versicolor, Eurotium group, and Cladosporium sphaerospermum) were > 1 (Group I). Logistic regression analysis of the sum of the logs of the concentrations of Group I species resulted in a 95% probability for separating MH from RH. These results suggest that it may be possible to evaluate whether a home has an abnormal mold condition by quantifying a limited number of mold species in a dust sample. Also, four common species of Aspergillus were quantified by standard culturing procedures and their concentrations compared to QPCR results. Culturing underestimated the concentrations of these four species by 2 to 3 orders of magnitude compared to QPCR. PMID:15237292

  18. Northern fowl mite (Ornithonyssus sylviarum) in Sweden.

    PubMed

    Jansson, D S; Otman, F; Lundqvist, L; Höglund, J; Engström, A; Chirico, J

    2014-12-01

    Haematophagous mites were collected from the vent region and plumage of chickens in six hobby flocks of ornamental breeds in Sweden, one of which included turkeys. Soiled vent skin and feathers, dermatitis, hyperkeratosis, skin necroses and ulcers were observed in 12 necropsied birds from two of the flocks. The mites were identified as the northern fowl mite Ornithonyssus sylviarum (Mesostigmata: Macronyssidae). This was supported by sequence analysis of a 642-bp region in the mitochondrial cytochrome oxidase subunit 1 (COI) gene (COI) in mites collected from five flocks, which showed 97-99% sequence similarity to O. sylviarum by blast analysis. Pairwise sequence comparisons revealed nucleotide variations in the range of 0-2.8%, whereas amino acid sequences were highly conserved. This paper represents one of very few records of O. sylviarum in European poultry, and is the first to report COI sequence data for O. sylviarum from poultry in Europe. PMID:24602037

  19. Comparison between Siriraj mite allergen vaccine and standardized commercial mite vaccine by skin prick testing in normal Thai adults.

    PubMed

    Visitsunthorn, Nualanong; Pacharn, Punchama; Jirapongsananuruk, Orathai; Weeravejsukit, Sirirat; Sripramong, Chaweewan; Sookrung, Nitat; Bunnag, Chaweewan

    2010-03-01

    House dust mite is a major cause of allergic asthma and rhinitis in Thai population. Skin prick test (SPT) is a useful tool for the diagnosis of the IgE-mediated reactions. The imported commercial mite vaccine for SPT is available but it is relatively expensive. Aim of this study is to compare Siriraj Mite Allergen Vaccine (SMAV) with standardized commercial mite allergen vaccine by skin prick testing in normal Thai adults. A double blind, self-controlled study between the SMAV and standardized commercial mite allergen vaccine was performed by SPT in 17 normal Thai adult males and non-pregnant or non-lactating females aged 18-60 years. The study showed that 35.29 % of non atopic adults had positive SPT reaction to Dp and Df of both SMAV and standardized commercial mite allergen vaccine. Mean wheal and flare diameters from SPT of Dp and Df of SMAV showed strong correlation with standardized commercial mite allergen vaccine (r= 0.768 and 0.897 in Dp and Df respectively, p <0.001). The intraclass correlation was also excellent (0.893 and 0.775 in Dp and Df respectively). There was no significant difference in wheal and flare diameter between SMAV and standardized commercial mite allergen vaccine. No systemic or large local reaction was found in any of the study cases.

  20. Revealing the large nuclear dust structures in NGC 1068 with MIDI/VLTI

    NASA Astrophysics Data System (ADS)

    López-Gonzaga, N.; Jaffe, W.; Burtscher, L.; Tristram, K. R. W.; Meisenheimer, K.

    2014-05-01

    Aims: The aim of this paper is to understand the relation in active galactic nuclei (AGNs) between the small obscuring torus and dusty structures at larger scales (5-10 pc). Methods: The dusty structures in AGNs are best observed in the mid-infrared. To achieve the necessary spatial resolution (20-100 millarcsec) we use ESO's Mid-Infrared Interferometer (MIDI) with the 1.8 m Auxiliary Telescopes. We use the chromatic phases in the data to improve the spatial fidelity of the analysis. Results: We present interferometric data for NGC 1068 obtained in 2007 and 2012. We find no evidence of source variability. Many (u,v) points show non-zero chromatic phases indicating significant asymmetries. Gaussian model fitting of the correlated fluxes and chromatic phases provides a three-component best fit with estimates of sizes, temperatures, and positions of the components. A large, warm, offcenter component is required at a distance approximately 90 mas to the northwest at a position angle (PA) of ~-18°. Conclusions: The dust at 5-10 pc in the polar region contributes four times more to the mid-infrared flux at 12 μm than the dust located at the center. This dust may represent the inner wall of a dusty cone. If similar regions are heated by the direct radiation from the nucleus, then they will contribute substantially to the classification of many Seyfert galaxies as Type 2. Such a region is also consistent in other Seyfert galaxies (the Circinus galaxy, NGC 3783, and NGC 424). Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme IDs 080.B-0928 and 089.B-0099. Based on data obtained from the ESO Science Archive Facility.Appendices are available in electronic form at http://www.aanda.orgThe reduced visibilities (UVFITS tables) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/565/A71

  1. House dust mite allergen Der p 1 elevates the release of inflammatory cytokines and expression of adhesion molecules in co-culture of human eosinophils and bronchial epithelial cells.

    PubMed

    Wong, Chun K; Li, Mandy L Y; Wang, Cheng B; Ip, Wai K; Tian, Ya P; Lam, Christopher W K

    2006-08-01

    House dust mite (HDM) is a common allergen of allergic asthma. Eosinophils are principal effector cells of allergic inflammation and their adhesion onto human bronchial epithelial cells is mediated by a CD18-intracellular adhesion molecule-1 (ICAM-1)-dependent interaction. We studied the effects of HDM Dermatophagoides pteronyssinus (Der p) 1 on the activation of eosinophils and bronchial epithelial BEAS-2B cells. Cytokines and adhesion molecules were measured using flow cytometry. Transcription factor nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1) and signaling molecule p38 mitogen-activated protein kinase (MAPK) were analyzed using electromobility shift assay and western blot, respectively. Der p 1 protein was found to potently induce the release of IL-1beta, IL-6, IL-10, tumor necrosis factor (TNF)-alpha and granulocyte macrophage colony-stimulating factor from eosinophils. Such induction was further up-regulated for IL-6 and IL-10, and down-regulated for TNF-alpha and IL-1beta in eosinophil-BEAS-2B cells co-culture. Surface expression of CD18 and ICAM-1 on eosinophils was greatly increased by Der p 1; such inductive effect on ICAM-1 was also found to be more prominent on BEAS-2B cells from the co-culture than BEAS-2B cells alone. Der p 1 was found to activate NF-kappaB and AP-1 activity in eosinophils alone and in co-culture and BEAS-2B cells in co-culture. Moreover, Der p 1 could activate p38 MAPK in BEAS-2B cells and eosinophils alone and in co-culture. Selective inhibition of NF-kappaB, AP-1 and p38 MAPK resulted in differential suppression of the Der p 1-induced cytokine release and adhesion molecule expression. As an allergen, HDM could therefore induce the release of inflammatory cytokines and expression of adhesion molecules from the interaction of human eosinophils and bronchial epithelial cells.

  2. [Seasonal changes in the count of mites of the family Pyroglyphidae in houses in the city of Cheboksary].

    PubMed

    Ivanov, L N; Petrova, Iu I

    1986-01-01

    The results of human dwelling houses surveying for the presence of home dust mites and study of seasonal changes of their quantity in the town of Cheboksary are given. It has been found that the old wooden houses are inhabited by mites, in modern blocks of flats they are met rather seldom. The quantity of alive mites is maximum in September-October. The common number of mites is the greatest in December-January although the quantity of alive mites at this time is only 6.8%. PMID:2939887

  3. CHARACTERIZING THE YOUNGEST HERSCHEL-DETECTED PROTOSTARS. I. ENVELOPE STRUCTURE REVEALED BY CARMA DUST CONTINUUM OBSERVATIONS

    SciTech Connect

    Tobin, John J.; Stutz, Amelia M.; Henning, Thomas; Ragan, Sarah E.; Megeath, S. Thomas; Fischer, William J.; Ali, Babar; Stanke, Thomas; Manoj, P.; Calvet, Nuria; Hartmann, Lee

    2015-01-10

    We present Combined Array for Research in Millimeter-wave Astronomy 2.9 mm dust continuum emission observations of a sample of 14 Herschel-detected Class 0 protostars in the Orion A and B molecular clouds, drawn from the PACS Bright Red Sources (PBRS) sample. These objects are characterized by very red 24-70 μm colors and prominent submillimeter emission, suggesting that they are very young Class 0 protostars embedded in dense envelopes. We detect all of the PBRS in 2.9 mm continuum emission and emission from four protostars and one starless core in the fields toward the PBRS; we also report one new PBRS source. The ratio of 2.9 mm luminosity to bolometric luminosity is higher by a factor of ∼5 on average, compared to other well-studied protostars in the Perseus and Ophiuchus clouds. The 2.9 mm visibility amplitudes for 6 of the 14 PBRS are very flat as a function of uv distance, with more than 50% of the source emission arising from radii <1500 AU. These flat visibility amplitudes are most consistent with spherically symmetric envelope density profiles with ρ ∝ R {sup –2.5}. Alternatively, there could be a massive unresolved structure like a disk or a high-density inner envelope departing from a smooth power law. The large amount of mass on scales <1500 AU (implying high average central densities) leads us to suggest that that the PBRS with flat visibility amplitude profiles are the youngest PBRS and may be undergoing a brief phase of high mass infall/accretion and are possibly among the youngest Class 0 protostars. The PBRS with more rapidly declining visibility amplitudes still have large envelope masses, but could be slightly more evolved.

  4. Magnetism of outdoor and indoor settled dust and its utilization as a tool for revealing the effect of elevated particulate air pollution on cardiovascular mortality

    NASA Astrophysics Data System (ADS)

    Jordanova, Diana; Jordanova, Neli; Lanos, Philippe; Petrov, Petar; Tsacheva, Tsenka

    2012-08-01

    Settled indoor and outdoor dusts in urban environment represent an important source of secondary pollution. Magnetic characteristics of the settled dust from six cities in Bulgaria are explored, allowing comparison on a national (country) scale. Monthly variations of the mass-specific magnetic susceptibilities (χindoor) and (χoutdoor) and calculated dust loading rates for a period of 17 months do not show seasonal variability, probably due to the dominant role of traffic-related emissions and soil-derived particles in the settled dust. The main magnetic mineral is magnetite, present as spherules and irregular particles of pseudo-single-domain grain sizes. Systematically lower remanence coercivities are obtained for outdoor dusts when compared with the corresponding indoor samples, implying that penetration of smaller particles of ambient origin indoors is the main source of the indoor dust. Mean yearly values of the ratio (χindoor/χoutdoor) for each city show statistically significant correlation with mortality due to cardiovascular diseases. This ratio reveals the source- and site-specific importance of the anthropogenically derived toxicogenic fraction. Heavy metal content of the settled dust is related to the contribution from several pollution sources (soil-derived, combustion and industrial), discriminated through analysis of principal components. SEM/EDX analyses reveal abundant presence of anthopogenic Fe-containing spherules, irregular particles and diesel exhaust conglomerates. High molecular weight polyaromatic hydrocarbons (PAH) dominate the total PAH content of the outdoor dust samples. The observed linear correlation between total PAH content, coercivity of remanence and the ratio Mrs/χ suggest either adsorption of PAHs on iron oxide particles and especially magnetite, or emission related increase in total PAH concentration along with a decrease of effective magnetic grain size of the accompanying magnetic fraction.

  5. Deformed wing virus: replication and viral load in mites (Varroa destructor).

    PubMed

    Gisder, Sebastian; Aumeier, Pia; Genersch, Elke

    2009-02-01

    Deformed wing virus (DWV) normally causes covert infections but can have devastating effects on bees by inducing morphological deformity or even death when transmitted by the ectoparasitic mite Varroa destructor. In order to determine the role of V. destructor in the development of crippled wings, we analysed individual mites for the presence and replication of DWV. The results supported the correlation between viral replication in mites and morphologically deformed bees. Quantification of viral genome equivalents revealed that mites capable of inducing an overt DWV infection contained 10(10)-10(12) genome equivalents per mite. In contrast, mites which could not induce crippled wings contained a maximum of only 10(8) viral genome equivalents per mite. We conclude that the development of crippled wings not only depends on DWV transmission by V. destructor but also on viral replication in V. destructor and on the DWV titre in the parasitizing mites.

  6. Multiple Infections with Cardinium and Two Strains of Wolbachia in The Spider Mite Tetranychus phaselus Ehara: Revealing New Forces Driving the Spread of Wolbachia

    PubMed Central

    Zhao, Dong-Xiao; Chen, Da-Song; Ge, Cheng; Gotoh, Tetsuo; Hong, Xiao-Yue

    2013-01-01

    Cytoplasmic incompatibility (CI) has been proposed as a major mechanism by which certain strains of Wolbachia to invade and persist in host populations. However, mechanisms that underlie the invasion and persistence of non-CI strains are less well understood. Here, we established a spider mite Tetranychus phaselus population multiply infected by Cardinium as well as two distinct lineages of Wolbachia, designated wCon and wOri, to study the forces driving the spread of the non-CI strain of Wolbachia wOri. Interestingly, we found that wOri provided a longevity advantage to its female hosts under ideal conditions, making wOri stay longer in this population, and then being transmitted to more offspring. Furthermore, the lifespan of uninfected females was reduced when mated with multiple-infected males. As a result, the uninfected population is attenuated by the multiple-infected males. Thus, we infer that the host age effects of multiple infection may represent sufficient forces driving the spread of wOri through the host population. PMID:23355904

  7. Mites and Wee Beasties.

    ERIC Educational Resources Information Center

    Reed, George H., Jr.

    1978-01-01

    A review is made of public health aspects of some arthropods that might be seen on a college or university campus. The diseases and infestations caused by mites, lice, bed bugs, fleas, and ticks are discussed. (JMF)

  8. Scabies mite, photomicrograph (image)

    MedlinePlus

    This is a photomicrograph of the scabies mite. This animal burrows in the skin, depositing both eggs and feces. Scabies infestation causes intense itching (pruritus) which leads to scratching and damage ...

  9. Scabies mite, photomicrograph (image)

    MedlinePlus

    This is a photomicrograph of the scabies mite. They burrows into the skin, depositing both eggs and feces. A scabies infestation causes intense itching (pruritus) which leads to scratching and damage ...

  10. [Epidemiological Studies On The Acaroid Mite

    PubMed

    Chu, Jung Kyun; Song, Soo Bok; Kim, Don Kyun; Kim, Yeong Kyu

    1967-06-01

    Epidemiological study on Acaroid mite in dust different sites were carried out and the following results were obtained. 1. Tyrophagus dimidiatus, Chibidania tokyoensis and Ornithonyssus nagayoi were found in living room(46.2 %), bath room(36.7 %), garden(27.0 %), shopping-store(28.8 %) and ware-house (29.2 %) in the Pusan area. 2. Dermanyssus gallinae and Rhizoglyphus echinopus were found mainly in class rooms of girl's high school(34.0 %) and class room of girl's middle school(40.0 %) as well as in primary school(13.2 %), but they are not found in class rooms of boys high school. 3. Generally, the various mites were found in the living room(57.0 %), under the carpet(50 %), under the furniture(52.0 %), on the furniture(27.5 %), lavatory(35.7 %) and garden(23.8 %).

  11. HIGH-REDSHIFT DUST OBSCURED GALAXIES: A MORPHOLOGY-SPECTRAL ENERGY DISTRIBUTION CONNECTION REVEALED BY KECK ADAPTIVE OPTICS

    SciTech Connect

    Melbourne, J.; Matthews, K.; Soifer, B. T. E-mail: bts@submm.caltech.edu

    2009-06-15

    A simple optical to mid-IR color selection, R - [24]>14, i.e., f {sub {nu}}(24 {mu}m)/f {sub {nu}}(R) {approx}> 1000, identifies highly dust obscured galaxies (DOGs) with typical redshifts of z {approx} 2 {+-} 0.5. Extreme mid-IR luminosities (L {sub IR} > 10{sup 12-14}) suggest that DOGs are powered by a combination of active galactic nuclei (AGNs) and star formation, possibly driven by mergers. In an effort to compare their photometric properties with their rest-frame optical morphologies, we obtained high-spatial resolution (0.''05-0.''1) Keck Adaptive Optics K'-band images of 15 DOGs. The images reveal a wide range of morphologies, including small exponential disks (eight of 15), small ellipticals (four of 15), and unresolved sources (two of 15). One particularly diffuse source could not be classified because of low signal-to-noise ratio. We find a statistically significant correlation between galaxy concentration and mid-IR luminosity, with the most luminous DOGs exhibiting higher concentration and smaller physical size. DOGs with high concentration also tend to have spectral energy distributions (SEDs) suggestive of AGN activity. Thus, central AGN light may be biasing the morphologies of the more luminous DOGs to higher concentration. Conversely, more diffuse DOGs tend to show an SED shape suggestive of star formation. Two of 15 in the sample show multiple resolved components with separations of {approx}1 kpc, circumstantial evidence for ongoing mergers.

  12. Association of House Dust Allergen Concentrations With Residential Conditions in City and in Rural Houses

    PubMed Central

    Wardzyńska, Aleksandra; Majkowska-Wojciechowska, Barbara; Pełka, Jolanta; Korzon, Leszek; Kaczała, Magdalena; Jarzębska, Marzanna; Gwardys, Tomasz

    2012-01-01

    Background The aim of the study was to evaluate the relationship between house dust mite, cat and dog allergen levels with household characteristics in the houses of children living in urban and rural areas in central Poland. Methods Dust samples were collected from 141 urban and 191 rural houses. Der f1 + Der p1, Can f 1, and Fel d1 levels were measured and associated with residential conditions and atopy-related health outcomes assessed by clinical examination and skin prick testing. Results Concentrations of mite allergens were lower, and cat and dog allergen levels were higher in urban houses. Fel d1 and Can f1 levels depended on the presence of a respective animal in the house. In urban houses, Der p1 + Der f1 concentration was lower in households with central heating, whereas Can f1 concentration was related to building age. Multivariate analyses revealed that the concentrations of house dust mite and dog allergens were associated with relative humidity, number of people in the household, and the presence of a dog at home. There was no significant association between allergen level and sensitization or atopic diseases. Conclusions Concentrations of indoor allergens in urban and rural houses differ significantly, and residential conditions associated with allergen levels seem to be different in both environments. PMID:23268467

  13. Potential lethal and non-lethal effects of predators on dispersal of spider mites.

    PubMed

    Otsuki, Hatsune; Yano, Shuichi

    2014-11-01

    Predators can affect prey dispersal lethally by direct consumption or non-lethally by making prey hesitate to disperse. These lethal and non-lethal effects are detectable only in systems where prey can disperse between multiple patches. However, most studies have drawn their conclusions concerning the ability of predatory mites to suppress spider mites based on observations of their interactions on a single patch or on heavily infested host plants where spider mites could hardly disperse toward intact patches. In these systems, specialist predatory mites that penetrate protective webs produced by spider mites quickly suppress the spider mites, whereas generalist predators that cannot penetrate the webs were ineffective. By using a connected patch system, we revealed that a generalist ant, Pristomyrmex punctatus Mayr (Hymenoptera: Formicidae), effectively prevented dispersal of spider mites, Tetranychus kanzawai Kishida (Acari: Tetranychidae), by directly consuming dispersing individuals. We also revealed that a generalist predatory mite, Euseius sojaensis Ehara (Acari: Phytoseiidae), prevented between-patch dispersal of T. kanzawai by making them hesitate to disperse. In contrast, a specialist phytoseiid predatory mite, Neoseiulus womersleyi Schicha, allowed spider mites to escape an initial patch, increasing the number of colonized patches within the system. Our results suggest that ants and generalist predatory mites can effectively suppress Tetranychus species under some conditions, and should receive more attention as agents for conservation biological control in agroecosystems.

  14. Dermatoses associated with mites other than Sarcoptes.

    PubMed

    Ken, Kimberly M; Shockman, Solomon C; Sirichotiratana, Melissa; Lent, Megan P; Wilson, Morgan L

    2014-09-01

    Mites are arthropods of the subclass Acari (Acarina). Although Sarcoptes is the mite most commonly recognized as a cause of human skin disease in the United States, numerous other mite-associated dermatoses have been described, and merit familiarity on the part of physicians treating skin disease. This review discusses several non-scabies mites and their associated diseases, including Demodex, chiggers, Cheyletiella, bird mites, grain itch, oak leaf itch, grocer's itch, tropical rat mite, snake mite, and Psoroptes. PMID:25577848

  15. Revealing the cold dust in low-metallicity environments. I. Photometry analysis of the Dwarf Galaxy Survey with Herschel

    NASA Astrophysics Data System (ADS)

    Rémy-Ruyer, A.; Madden, S. C.; Galliano, F.; Hony, S.; Sauvage, M.; Bendo, G. J.; Roussel, H.; Pohlen, M.; Smith, M. W. L.; Galametz, M.; Cormier, D.; Lebouteiller, V.; Wu, R.; Baes, M.; Barlow, M. J.; Boquien, M.; Boselli, A.; Ciesla, L.; De Looze, I.; Karczewski, O. Ł.; Panuzzo, P.; Spinoglio, L.; Vaccari, M.; Wilson, C. D.

    2013-09-01

    Context. We present new photometric data from our Herschel guaranteed time key programme, the Dwarf Galaxy Survey (DGS), dedicated to the observation of the gas and dust in low-metallicity environments. A total of 48 dwarf galaxies were observed with the PACS and SPIRE instruments onboard the Herschel Space Observatory at 70, 100, 160, 250, 350, and 500 μm. Aims: The goal of this paper is to provide reliable far-infrared (FIR) photometry for the DGS sample and to analyse the FIR/submillimetre (submm) behaviour of the DGS galaxies. We focus on a systematic comparison of the derived FIR properties (FIR luminosity, LFIR, dust mass, Mdust, dust temperature, T, emissivity index, β) with more metal-rich galaxies and investigate the detection of a potential submm excess. Methods: The data reduction method is adapted for each galaxy in order to derive the most reliable photometry from the final maps. The derived PACS flux densities are compared with the Spitzer MIPS 70 and 160 μm bands. We use colour-colour diagrams to analyse the FIR/submm behaviour of the DGS galaxies and modified blackbody fitting procedures to determine their dust properties. To study the variation in these dust properties with metallicity, we also include galaxies from the Herschel KINGFISH sample, which contains more metal-rich environments, totalling 109 galaxies. Results: The location of the DGS galaxies on Herschel colour-colour diagrams highlights the differences in dust grain properties and/or global environments of low-metallicity dwarf galaxies. The dust in DGS galaxies is generally warmer than in KINGFISH galaxies (TDGS ~ 32 K and TKINGFISH ~ 23 K). The emissivity index, β, is ~1.7 in the DGS, however metallicity does not make a strong effect on β. The proportion of dust mass relative to stellar mass is lower in low-metallicity galaxies: Mdust/Mstar ~ 0.02% for the DGS versus 0.1% for KINGFISH. However, per unit dust mass, dwarf galaxies emit about six times more in the FIR/submm than

  16. Effects of an acaricide on mite allergen levels in the homes of asthmatic children.

    PubMed

    Chew, F T; Goh, D Y; Lee, B W

    1996-10-01

    Previous study by the current authors has shown that treating homes with D'Allergen, an acaricidal agent, can reduce bronchial hyper-reactivity in asthmatic children with house dust mite allergy. In the present study, the effects of a single D'Allergen treatment on the levels of major dust mite allergens, Der p I and Der f I was evaluated, and the duration of its effectiveness in the environment determined. Twenty randomly selected homes were treated with the acaricide and ten remained untreated. Dust samples were collected from mattresses, upholstered sofas and carpets of these homes before and 1, 2 and 4 months after treatment. The samples were then assayed for Der p I and Der f I allergens using a sandwich enzyme immunoassay. The results showed that D'Allergen was effective in reducing dust mite allergen levels in all three niches by 1.5-22.3 times below baseline values. This effect, however, was only present for 2 months, and the dust mite allergen levels increased to those of the baseline by the fourth month after treatment. These results indicated that repeated applications of the acaricide were required at 2-3 monthly intervals to obtain optimal effectiveness.

  17. Field study on the efficacy of an extract of neem seed (Mite -Stop) against the red mite Dermanyssus gallinae naturally infecting poultry in Egypt.

    PubMed

    Abdel-Ghaffar, Fathy; Sobhy, Hassan M; Al-Quraishy, Saleh; Semmler, Margit

    2008-08-01

    Infestations with the poultry red mite Dermanyssus gallinae represent a major ectoparasite problem in poultry and affects egg and meat production worldwide. The effects of the neem seed product Mite-Stop against the red poultry mite were investigated. Five primitive poultry farms in two small villages in the Nile Delta and Giza district were selected for the study. The neem extract was diluted 1:40 and 1:50 with tap water just prior to use. Application of the two dilutions of the provided product was performed to soil, cracks and crevices of the examined area as well as to mite-infested birds on day 0 and day 7. Two hours after treatment soil dust was collected from sprayed regions of the stable and from unsprayed control regions of the same stable. The treated chickens were also checked for mites 2 h after each treatment. The examination of the chickens 2 h after spraying showed that they were free of mites. The examination of treated soil with the Tullgren funnel apparatus 2 h after the first spraying on day 0 already showed a considerable reduction of living mites compared to controls. Seven days after the first treatment of the soil the number of living mites was reduced for 80% in the treated soil and decreased even more after the second spraying, since those larvae that had hatched from eggs in the meantime were killed. The 1:40 dilution of the neem seed extract with tap water was superior to the 1:50 dilution. These results clearly show a very high killing rate of the extract, if the mites come in direct contact with the compound. However, in order to obtain extinction also of hidden and freshly hatched stages repeated spraying should be done three times within 8-10 days. PMID:18481087

  18. Clumpy dust clouds and extended atmosphere of the AGB star W Hydrae revealed with VLT/SPHERE-ZIMPOL and VLTI/AMBER

    NASA Astrophysics Data System (ADS)

    Ohnaka, K.; Weigelt, G.; Hofmann, K.-H.

    2016-05-01

    Context. Dust formation is thought to play an important role in the mass loss from stars at the asymptotic giant branch (AGB); however, where and how dust forms is still open to debate. Aims: We present visible polarimetric imaging observations of the well-studied AGB star W Hya taken with VLT/SPHERE-ZIMPOL as well as high spectral resolution long-baseline interferometric observations taken with the AMBER instrument at the Very Large Telescope Interferometer (VLTI). Our goal is to spatially resolve the dust and molecule formation region within a few stellar radii. Methods: We observed W Hya with VLT/SPHERE-ZIMPOL at three wavelengths in the continuum (645, 748, and 820 nm), in the Hα line at 656.3 nm, and in the TiO band at 717 nm. The VLTI/AMBER observations were carried out in the wavelength region of the CO first overtone lines near 2.3 μm with a spectral resolution of 12000. Results: Taking advantage of the polarimetric imaging capability of SPHERE-ZIMPOL combined with the superb adaptive optics performance, we succeeded in spatially resolving three clumpy dust clouds located at ~50 mas (~2 R⋆) from the central star, revealing dust formation very close to the star. The AMBER data in the individual CO lines suggest a molecular outer atmosphere extending to ~3 R⋆. Furthermore, the SPHERE-ZIMPOL image taken over the Hα line shows emission with a radius of up to ~160 mas (~7 R⋆). We found that dust, molecular gas, and Hα-emitting hot gas coexist within 2-3 R⋆. Our modeling suggests that the observed polarized intensity maps can reasonably be explained by large (0.4-0.5 μm) grains of Al2O3, Mg2SiO4, or MgSiO3 in an optically thin shell (τ550nm = 0.1 ± 0.02) with an inner and outer boundary radius of 1.9-2.0 R⋆ and 3 ± 0.5R⋆, respectively. The observed clumpy structure can be reproduced by a density enhancement of a factor of 4 ± 1. Conclusions: The grain size derived from our modeling of the SPHERE-ZIMPOL polarimetric images is consistent with

  19. AGN - Dust-Obscured Galaxies at z~1-3 revealed by near-to-far infrared SED-fitting

    NASA Astrophysics Data System (ADS)

    Riguccini, Laurie

    Dust-Obscured galaxies (DOGs, Dey et al. 2008) are bright 24μm-selected sources with extreme obscuration at optical wavelengths (F24μ m /F R > 982). Recent studies (Dey et al. 2008, Bussmann et al. 2009) describe an evolutionary scenario in which the starbursting nature of submillimeter galaxies (SMGs) evolves into the composite nature of DOGs as an underlying AGN grows; this is followed by a quasar phase that terminates star formation (SF), leading to the formation of a passive, massive elliptical galaxy. Within this context, DOGs could provide a key insight to an extremely dusty stage in the evolution of galaxies at z ~ 2, where both AGN and SF activity coexist.

  20. New emerging results on molecular gas, stars, and dust at z~2, as revealed by low star formation rate and low stellar mass star-forming galaxies

    NASA Astrophysics Data System (ADS)

    Dessauges-Zavadsky, Miroslava; Schaerer, Daniel; Combes, Francoise; Egami, Eiichi; Swinbank, Mark; Richard, Johan; Sklias, Panos; Rawle, Tim D.

    2015-08-01

    The large surveys of main sequence star-forming galaxies (SFGs) at z~2, made at near-IR and mm wavelengths, have revolutionized our picture of galaxies at this critical epoch, where the cosmic star formation rate (SFR) density is at its peak and the stellar mass (Ms) assembly is rapid. They reveal that ~70% of SFGs are young, rotation dominated disk-like systems, yet dynamically hotter and geometrically thicker than local spirals, with larger molecular gas fractions (fgas).It is time to refine this modern picture of z~2 galaxies by extending the current studies toward the more numerous and typical SFGs, characterized by SFRdust properties in 8 such sub-SFR*, lensed SFGs at z=1.5-3.6, achieved thanks to gravitational lensing and IRAM/PdBI, Herschel, Spitzer, and HST multi-wavelength data. They extend the dynamical range in SFR and Ms of our compilation of CO-detected SFGs at z>1 from the literature, and allow us to revisit and propose new correlations between IR and CO luminosities, molecular gas, stellar and dust masses, specific SFR, molecular gas depletion timescales (tdepl), fgas, dust-to-gas ratios, and redshift, to be directly compared with galaxy evolution models.We find an increase of tdepl with Ms, as now revealed by low-Ms SFGs at z>1 and also observed at z=0, which contrasts with the acknowledged constant tdepl in "bathtub" models and refutes the linearity of the Kennicutt-Schmidt relation. A steady increase of fgas with redshift is predicted by cosmological models and is observed from z~0 to z~1.5, but is followed by a mild increase toward higher redshifts, which we further confirm with our highest redshift CO measurement in an SFR* galaxy at z=3.6. We provide the first fgas measure in z>1 SFGs at the low-Ms end 109.4

  1. Identification of molecular markers associated with mite resistance in coconut (Cocos nucifera L.).

    PubMed

    Shalini, K V; Manjunatha, S; Lebrun, P; Berger, A; Baudouin, L; Pirany, N; Ranganath, R M; Prasad, D Theertha

    2007-01-01

    Coconut mite (Aceria guerreronis 'Keifer') has become a major threat to Indian coconut (Coçcos nucifera L.) cultivators and the processing industry. Chemical and biological control measures have proved to be costly, ineffective, and ecologically undesirable. Planting mite-resistant coconut cultivars is the most effective method of preventing yield loss and should form a major component of any integrated pest management stratagem. Coconut genotypes, and mite-resistant and -susceptible accessions were collected from different parts of South India. Thirty-two simple sequence repeat (SSR) and 7 RAPD primers were used for molecular analyses. In single-marker analysis, 9 SSR and 4 RAPD markers associated with mite resistance were identified. In stepwise multiple regression analysis of SSRs, a combination of 6 markers showed 100% association with mite infestation. Stepwise multiple regression analysis for RAPD data revealed that a combination of 3 markers accounted for 83.86% of mite resistance in the selected materials. Combined stepwise multiple regression analysis of RAPD and SSR data showed that a combination of 5 markers explained 100% of the association with mite resistance in coconut. Markers associated with mite resistance are important in coconut breeding programs and will facilitate the selection of mite-resistant plants at an early stage as well as mother plants for breeding programs. PMID:17546069

  2. [The effect of a mite allergen on Na/H metabolic activity in peritoneal mast cells].

    PubMed

    Khlgatian, S V; Pinelis, V G; Berzhets, V M; Strukova, S M

    1992-12-01

    Mite allergen interacting with mast cells treated with sera from bronchial patient sensitized to home dust Dermatophagoides farinae causes changes in intracellular pH. Regulation of pHi peritoneal mast cells is participated by Na/H metabolism probably activated by protein kinase C.

  3. New emerging results on molecular gas, stars, and dust at z ~ 2, as revealed by low star formation rate and low stellar mass star-forming galaxies

    NASA Astrophysics Data System (ADS)

    Dessauges-Zavadsky, Miroslava; Zamojski, Michel; Schaerer, Daniel; Combes, Françoise; Egami, Eiichi; Sklias, Panos; Swinbank, Mark A.; Richard, Johan; Rawle, Tim

    Recent CO surveys of star-forming galaxies (SFGs) at z ~ 2 have revolutionized our picture of massive galaxies. It is time to expand these studies toward the more common z ~ 2 SFGs with SFR < 40 M ⊙ yr-1 and M * < 2.5 × 1010 M⊙. We have derived molecular gas, stars, and dust in 8 such lensed SFGs. They extend the L IR-L'CO(1-0) distribution of massive z>1 SFGs and increase the spread of the SFG star formation efficiency (SFE). A single star formation relation is found when combining all existing CO-detected galaxies. Our low-M * SFGs also reveal a SFE decrease with M * as found locally. A rise of the molecular gas fraction (f gas) with redshift is observed up to z ~ 1.6, but it severely flattens toward higher redshifts. We provide the first insight into the f gas upturn at the low-M * end 109.4 < M */M⊙ < 1010 reaching f gas ~ 0.7, it is followed by a f gas decrease toward higher M *. Finally, we find a non-universal dust-to-gas ratio among local and high-redshift SFGs and starbursts with near-solar metallicities.

  4. Structural Mechanisms of Inactivation in Scabies Mite Serine Protease Paralogues

    SciTech Connect

    Fischer, Katja; Langendorf, Christopher G.; Irving, James A.; Reynolds, Simone; Willis, Charlene; Beckham, Simone; Law, Ruby H.P.; Yang, Sundy; Bashtannyk-Puhalovich, Tanya A.; McGowan, Sheena; Whisstock, James C.; Pike, Robert N.; Kemp, David J.; Buckle, Ashley M.

    2009-08-07

    The scabies mite (Sarcoptes scabiei) is a parasite responsible for major morbidity in disadvantaged communities and immuno-compromised patients worldwide. In addition to the physical discomfort caused by the disease, scabies infestations facilitate infection by Streptococcal species via skin lesions, resulting in a high prevalence of rheumatic fever/heart disease in affected communities. The scabies mite produces 33 proteins that are closely related to those in the dust mite group 3 allergen and belong to the S1-like protease family (chymotrypsin-like). However, all but one of these molecules contain mutations in the conserved active-site catalytic triad that are predicted to render them catalytically inactive. These molecules are thus termed scabies mite inactivated protease paralogues (SMIPPs). The precise function of SMIPPs is unclear; however, it has been suggested that these proteins might function by binding and protecting target substrates from cleavage by host immune proteases, thus preventing the host from mounting an effective immune challenge. In order to begin to understand the structural basis for SMIPP function, we solved the crystal structures of SMIPP-S-I1 and SMIPP-S-D1 at 1.85 {angstrom} and 2.0 {angstrom} resolution, respectively. Both structures adopt the characteristic serine protease fold, albeit with large structural variations over much of the molecule. In both structures, mutations in the catalytic triad together with occlusion of the S1 subsite by a conserved Tyr200 residue is predicted to block substrate ingress. Accordingly, we show that both proteases lack catalytic function. Attempts to restore function (via site-directed mutagenesis of catalytic residues as well as Tyr200) were unsuccessful. Taken together, these data suggest that SMIPPs have lost the ability to bind substrates in a classical 'canonical' fashion, and instead have evolved alternative functions in the lifecycle of the scabies mite.

  5. Presence and density of domestic mites in the microenvironment of mite-sensitive dogs with atopic dermatitis.

    PubMed

    Farmaki, Rania; Saridomichelakis, Manolis N; Leontides, Leonidas; Papazahariadou, Margarita G; Gioulekas, Dimitrios; Koutinas, Alexander F

    2010-10-01

    This study was designed to investigate the presence and density of domestic mites (DMs) in households with atopic dogs sensitive to these mites (group A; n=20), in households with clinically healthy, nonatopic dogs (group B; n=20) and in households without pets (group C; n=25). Dust samples were vacuum-collected from the owner mattress (all groups) and dog sleeping area (groups A and B) or living room couch (group C) on four consecutive occasions, reflecting the four seasons of the year. DMs were found, at least once, in 19 of 20 (95%) group A, 13 of 20 (65%) group B and 21 of 25 (84%) group C households. DM numbers per gram of dust were 0-159 (median, 8.8), 0-302 (median, 3) and 0-1473 (median, 6.9) for group A, B and C, respectively. Dermatophagoides farinae predominated in all groups, since it was identified in 60% of group A, 40% of group B and 64% of group C households. Dermatophagoides pteronyssinus was found in 45%, 35% and 48% of households, in group A, B and C, respectively. No differences were found between households with (groups A and B) or without dogs (group C). When considering both sampling sites together, frequency of DM recovery was higher in group A than in group B (P=0.044). Also, both mite frequency (P=0.011) and density (P=0.015) in dog sleeping area were higher in group A than in group B. In conclusion, presence and density of DMs is higher in the microenvironment of mite-sensitive dogs with atopic dermatitis than in that of clinically healthy nonatopic dogs.

  6. Dietary effects on body weight of predatory mites (Acari, Phytoseiidae).

    PubMed

    Goleva, Irina; Rubio Cadena, Esteban C; Ranabhat, Nar B; Beckereit, Caroline; Zebitz, Claus P W

    2015-08-01

    Pollen is offered as alternative or supplementary food for predacious mites; however, it may vary in its nutritional value. Body weight appears a representative parameter to describe food quality. Thus, we assessed the body weight for adults of the generalist mites Amblyseius swirskii, Amblydromalus limonicus, and Neoseiulus cucumeris reared on 22, 12, and 6 pollen species, respectively. In addition, A. swirskii and A. limonicus was reared on codling moth eggs. In all mite species, female body weight was higher than that of males, ranging between 4.33 and 8.18 µg for A. swirskii, 2.56-6.53 µg for A. limonicus, and 4.66-5.92 µg for N. cucumeris. Male body weight ranged between 1.78 and 3.28 µg, 1.37-3.06 µg, and 2.73-3.03 µg, respectively. Nutritional quality of pollen was neither consistent among the mite species nor among sex, revealing superior quality of Quercus macranthera pollen for females of A. swirskii and Tulipa gesneriana pollen for males, Alnus incana pollen for females of A. limonicus and Aesculus hippocastanum pollen for males, and Ae. hippocastanum pollen for both sexes of N. cucumeris. The results are discussed against the background of known or putative pollen chemistry and mite's nutritional physiology. PMID:26014648

  7. Determination of pH in Regions of the Midguts of Acaridid Mites

    PubMed Central

    Erban, Tomas; Hubert, Jan

    2010-01-01

    The pH of the guts of mites strongly affects their digestive processes. This study was carried out to determine the pH in the guts of 12 species of stored product and house dust mites. Eighteen pH indicators were chosen and offered to the mites in the feeding biotest. Based on the color changes of the indicators, the gut contents of acaridid mites were determined to be within a pH range of 4 to neutral. The gut contents showed a gradient in pH from the anterior to the posterior part. The anterior midgut (ventriculus and caeca) of most species had a pH ranging from 4.5 to 5, or slightly more alkaline for most of the species, while the middle midgut (intercolon/colon) had a pH of 5 to 6. Finally, the pH of the posterior midgut (postcolon) was between 5.5 and 7. Except for Dermatophagoides spp., no remarkable differences in the pH of the gut were observed among the tested species. Dermatophagoides spp. had a more acidic anterior midgut (a pH of 4 to 5) and colon (a pH of 5) with postcolon (a pH of below 6). The results characterizing in vivo conditions in the mite gut offer useful information to study the activity of mite digestive enzymes including their inhibitors and gut microflora. PMID:20572792

  8. DIVERSITY OF FEATHER MITES (ACARI: ASTIGMATA) ON DARWIN’S FINCHES

    PubMed Central

    Villa, Scott M.; Le Bohec, Céline; Koop, Jennifer A. H.; Proctor, Heather C.; Clayton, Dale H.

    2014-01-01

    Feather mites are a diverse group of ectosymbionts that occur on most species of birds. Although Darwin’s finches are a well-studied group of birds, relatively little is known about their feather mites. Nearly 200 birds across 9 finch species, and from 2 locations on Santa Cruz Island, Galápagos, were dust-ruffled during the 2009 breeding season. We found 8 genera of feather mites; the most prevalent genus was Mesalgoides (53–55%), followed by Trouessartia (40–45%), Amerodectes and Proctophyllodes (26–33%), Xolalgoides (21–27%), Analges and Strelkoviacarus (0–6%), and Dermoglyphus (2–4%). There was no evidence for microclimatic effects (ambient temperature and relative humidity) on mite diversity. Host body mass was significantly correlated with mean feather mite abundance across 7 of 8 well-sampled species of finches. Certhidea olivacea, the smallest species, did not fit this pattern and had a disproportionately high number of mites for its body mass. PMID:23691947

  9. Ectoparasitic mite and fungus on Harmonia axyridis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ectoparasitic mites (Acarina: Podapolipidae) and ectoparasitic fungi (Laboulbeniales: Laboulbeniaceae) occur on ladybirds (Coleoptera: Coccinellidae) throughout the world (Riddick et al., 2009). This study documents the interaction of a coccinellid-specific mite Coccipolipus hippodamiae (McDaniel &...

  10. Flat mites of the world - Edition 2

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Flat Mites of the World has an interactive key, fact sheets, descriptions, and images to aid in the identification of flat mites (Acari: Trombidiformes: Tetranychoidea: Tenuipalpidae) worldwide. The tool will help identify 36 genera of flat mites, including specific diagnostics for 13 species of...

  11. The efficacy of neem seed extracts (Tre-san, MiteStop on a broad spectrum of pests and parasites.

    PubMed

    Schmahl, Günter; Al-Rasheid, Khaled A S; Abdel-Ghaffar, Fathy; Klimpel, Sven; Mehlhorn, Heinz

    2010-07-01

    The paper summarizes the acaricidal and insecticidal effects of a patented neem seed extract when diluted 1:10 with shampoo or 1:20, 1:30, 1:33, 1:40, respectively, 1:66 with tap water. It was shown that a broad range of pests and parasites, such as house dust mites, poultry mites, harvest mites, Ixodes and Rhipicephalus ticks, cat fleas (adults, larvae), bed bugs (all stages), head lice and mallophaga, cockroaches (genera Blatta, Blattella, Gomphadorhina), raptor bugs (Triatoma), and even food-attacking beetle (Tenebrio molitor) might be controlled with this extract, which is available as Tre-san (against house dust mites) and MiteStop (against mites, ticks, insects of any kind) to become water diluted or as Wash Away Louse or Picksan LouseStop being diluted in a shampoo. Tests on skin compatibility proved that there are no skin irritations during or after use. However, some target species are less sensible (beetles, Triatoma stages, fly maggots), while the specimens of the other species cited above were successfully killed even at low concentrations of the extract. PMID:20461406

  12. Ectoparasitic chigger mites on large oriental vole (Eothenomys miletus) across southwest, China.

    PubMed

    Peng, Pei-Ying; Guo, Xian-Guo; Song, Wen-Yu; Hou, Peng; Zou, Yun-Ji; Fan, Rong

    2016-02-01

    An investigation of chigger mites on the large oriental vole, Eothenomys miletus (Rodentia: Cricetidae), was conducted between 2001 and 2013 at 39 localities across southwest China, and 2463 individuals of the vole hosts were captured and examined, which is a big host sample size. From the body surface of E. miletus, 49,850 individuals of chigger mites were collected, and they were identified as comprising 175 species, 13 genera, and 3 subfamilies in 2 families (Trombiculidae and Leeuwenhoekiidae). The 175 species of chigger mites from such a single rodent species (E. miletus) within a certain region (southwest China) extremely exceeded all the species of chigger mites previously recorded from multiple species of hosts in a wide region or a whole country in some other countries, and this suggests that E. miletus has a great potential to harbor abundant species of chigger mites on its body surface. Of 175 mite species, Leptotrombidium scutellare was the most dominant species, which has been proved as one of the main vectors of scrub typhus and the potential vector of haemorrhagic fever with renal syndrome (HFRS) in China. The patchiness index (m*/m) was used to measure the spatial patterns of the dominant chigger mite species, and all the three dominant mite species (L. scutellare, Leptotrombidium sinicum, and Helenicula simena) showed aggregated distributions among the different host individuals. The coefficient of association (V) was adopted to measure the interspecies interaction between the dominant mite species and a slightly positive association existed between L. scutellare and L. sinicum (V = 0.28, P < 0.01), which implies that these two mite species can co-exist on the same species of the host, E. miletus. The tendency curve of species abundance showed that the number of chigger mite species gradually decreased with the increase of mite individuals, and this revealed that most chigger mite species were rare with very few individuals, but few

  13. Ectoparasitic chigger mites on large oriental vole (Eothenomys miletus) across southwest, China.

    PubMed

    Peng, Pei-Ying; Guo, Xian-Guo; Song, Wen-Yu; Hou, Peng; Zou, Yun-Ji; Fan, Rong

    2016-02-01

    An investigation of chigger mites on the large oriental vole, Eothenomys miletus (Rodentia: Cricetidae), was conducted between 2001 and 2013 at 39 localities across southwest China, and 2463 individuals of the vole hosts were captured and examined, which is a big host sample size. From the body surface of E. miletus, 49,850 individuals of chigger mites were collected, and they were identified as comprising 175 species, 13 genera, and 3 subfamilies in 2 families (Trombiculidae and Leeuwenhoekiidae). The 175 species of chigger mites from such a single rodent species (E. miletus) within a certain region (southwest China) extremely exceeded all the species of chigger mites previously recorded from multiple species of hosts in a wide region or a whole country in some other countries, and this suggests that E. miletus has a great potential to harbor abundant species of chigger mites on its body surface. Of 175 mite species, Leptotrombidium scutellare was the most dominant species, which has been proved as one of the main vectors of scrub typhus and the potential vector of haemorrhagic fever with renal syndrome (HFRS) in China. The patchiness index (m*/m) was used to measure the spatial patterns of the dominant chigger mite species, and all the three dominant mite species (L. scutellare, Leptotrombidium sinicum, and Helenicula simena) showed aggregated distributions among the different host individuals. The coefficient of association (V) was adopted to measure the interspecies interaction between the dominant mite species and a slightly positive association existed between L. scutellare and L. sinicum (V = 0.28, P < 0.01), which implies that these two mite species can co-exist on the same species of the host, E. miletus. The tendency curve of species abundance showed that the number of chigger mite species gradually decreased with the increase of mite individuals, and this revealed that most chigger mite species were rare with very few individuals, but few

  14. Grain dust and the lungs.

    PubMed Central

    Chan-Yeung, M.; Ashley, M. J.; Grzybowski, S.

    1978-01-01

    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. Images p1272-a PMID:348288

  15. Breaking the Curve with CANDELS: A Bayesian Approach to Reveal the Non-Universality of the Dust-Attenuation Law at High Redshift

    NASA Astrophysics Data System (ADS)

    Salmon, Brett; Papovich, Casey; Long, James; Willner, S. P.; Finkelstein, Steven L.; Ferguson, Henry C.; Dickinson, Mark; Duncan, Kenneth; Faber, S. M.; Hathi, Nimish; Koekemoer, Anton; Kurczynski, Peter; Newman, Jeffery; Pacifici, Camilla; Pérez-González, Pablo G.; Pforr, Janine

    2016-08-01

    Dust attenuation affects nearly all observational aspects of galaxy evolution, yet very little is known about the form of the dust-attenuation law in the distant universe. Here, we model the spectral energy distributions of galaxies at z ˜ 1.5–3 from CANDELS with rest-frame UV to near-IR imaging under different assumptions about the dust law, and compare the amount of inferred attenuated light with the observed infrared (IR) luminosities. Some individual galaxies show strong Bayesian evidence in preference of one dust law over another, and this preference agrees with their observed location on the plane of infrared excess (IRX, {L}{TIR}/{L}{UV}) and UV slope (β). We generalize the shape of the dust law with an empirical model, {A}λ ,δ =E{(B-V){k}λ (λ /{λ }V)}δ where k λ is the dust law of Calzetti et al., and show that there exists a correlation between the color excess E(B-V) and tilt δ with δ =(0.62+/- 0.05){log}(E(B-V))+(0.26+/- 0.02). Galaxies with high color excess have a shallower, starburst-like law, and those with low color excess have a steeper, SMC-like law. Surprisingly, the galaxies in our sample show no correlation between the shape of the dust law and stellar mass, star formation rate, or β. The change in the dust law with color excess is consistent with a model where attenuation is caused by scattering, a mixed star–dust geometry, and/or trends with stellar population age, metallicity, and dust grain size. This rest-frame UV-to-near-IR method shows potential to constrain the dust law at even higher redshifts (z\\gt 3).

  16. Breaking the Curve with CANDELS: A Bayesian Approach to Reveal the Non-Universality of the Dust-Attenuation Law at High Redshift

    NASA Astrophysics Data System (ADS)

    Salmon, Brett; Papovich, Casey; Long, James; Willner, S. P.; Finkelstein, Steven L.; Ferguson, Henry C.; Dickinson, Mark; Duncan, Kenneth; Faber, S. M.; Hathi, Nimish; Koekemoer, Anton; Kurczynski, Peter; Newman, Jeffery; Pacifici, Camilla; Pérez-González, Pablo G.; Pforr, Janine

    2016-08-01

    Dust attenuation affects nearly all observational aspects of galaxy evolution, yet very little is known about the form of the dust-attenuation law in the distant universe. Here, we model the spectral energy distributions of galaxies at z ˜ 1.5-3 from CANDELS with rest-frame UV to near-IR imaging under different assumptions about the dust law, and compare the amount of inferred attenuated light with the observed infrared (IR) luminosities. Some individual galaxies show strong Bayesian evidence in preference of one dust law over another, and this preference agrees with their observed location on the plane of infrared excess (IRX, {L}{TIR}/{L}{UV}) and UV slope (β). We generalize the shape of the dust law with an empirical model, {A}λ ,δ =E{(B-V){k}λ (λ /{λ }V)}δ where k λ is the dust law of Calzetti et al., and show that there exists a correlation between the color excess E(B-V) and tilt δ with δ =(0.62+/- 0.05){log}(E(B-V))+(0.26+/- 0.02). Galaxies with high color excess have a shallower, starburst-like law, and those with low color excess have a steeper, SMC-like law. Surprisingly, the galaxies in our sample show no correlation between the shape of the dust law and stellar mass, star formation rate, or β. The change in the dust law with color excess is consistent with a model where attenuation is caused by scattering, a mixed star-dust geometry, and/or trends with stellar population age, metallicity, and dust grain size. This rest-frame UV-to-near-IR method shows potential to constrain the dust law at even higher redshifts (z\\gt 3).

  17. High Varroa mite abundance influences chemical profiles of worker bees and mite-host preferences.

    PubMed

    Cervo, R; Bruschini, C; Cappa, F; Meconcelli, S; Pieraccini, G; Pradella, D; Turillazzi, S

    2014-09-01

    Honeybee disappearance is one of the major environmental and economic challenges this century has to face. The ecto-parasitic mite Varroa destructor represents one of the main causes of the worldwide beehive losses. Although halting mite transmission among beehives is of primary importance to save honeybee colonies from further decline, the natural route used by mites to abandon a collapsing colony has not been extensively investigated so far. Here, we explored whether, with increasing mite abundance within the colony, mites change their behaviour to maximize the chances of leaving a highly infested colony. We show that, at low mite abundance, mites remain within the colony and promote their reproduction by riding nurses that they distinguish from foragers by different chemical cuticular signatures. When mite abundance increases, the chemical profile of nurses and foragers tends to overlap, promoting mite departure from exploited colonies by riding pollen foragers. PMID:25165133

  18. Why do Varroa mites prefer nurse bees?

    PubMed Central

    Xie, Xianbing; Huang, Zachary Y.; Zeng, Zhijiang

    2016-01-01

    The Varroa mite, Varroa destructor, is an acarine ecto-parasite on Apis mellifera. It is the worst pest of Apis mellifera, yet its reproductive biology on the host is not well understood. In particular, the significance of the phoretic stage, when mites feed on adult bees for a few days, is not clear. In addition, it is not clear whether the preference of mites for nurses observed in the laboratory also happens inside real colonies. We show that Varroa mites prefer nurses over both newly emerged bees and forgers in a colony setting. We then determined the mechanism behind this preference. We show that this preference maximizes Varroa fitness, although due to the fact that each mite must find a second host (a pupa) to reproduce, the fitness benefit to the mites is not immediate but delayed. Our results suggest that the Varroa mite is a highly adapted parasite for honey bees. PMID:27302644

  19. Honey Bees: Sweetness and Mites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Honey bee colony losses have been in the news lately and the potential reasons for these losses have taken up much space in the news media. In order to clarify what role mites play in the current loss (2006-2007) of bee colonies, called Colony Collapse Disorder, a better understanding of what a mit...

  20. Dust Detector

    NASA Technical Reports Server (NTRS)

    Kelley, M. C.

    2001-01-01

    We discuss a recent sounding rocket experiment which found charged dust in the Earth's tropical mesosphere. The dust detector was designed to measure small (5000 - 10000 amu.) charged dust particles, most likely of meteoric origin. A 5 km thick layer of positively charged dust was found at an altitude of 90 km, in the vicinity of an observed sporadic sodium layer and sporadic E layer. The observed dust was positively charged in the bulk of the dust layer, but was negatively charged near the bottom.

  1. Revealing Exo-Zody and Exo-Planets from Solar System Dust Measurements: ALADDIN-2 for the Solar Power Sail Mission

    NASA Astrophysics Data System (ADS)

    Yano, Hajime; Hirai, Takayuki

    2016-07-01

    The dust structure of our Solar System provides a benchmark information of dust disks of other exo-planetary systems in general, just like the Sun as the closest main sequence G-star that we can study with the most details. Heliocentric dust distributions and gravitational and orbital interactions with planets such as mean motion resonances (MMRs) of dust flux of our Solar System are what we can transfer the knowledge of our Solar System dust apply to infer anisotropic exo-zodiacal brightness, or spatial structures within a exo-planetary dust disks with information about potentially embedded planets inside. In the coming era of disk resolved observations by ALMA, TMT and other new telescopes, we will be able to apply what we find in the Solar System to the rest of planetary systems. In 2010-11, the IKAROS solar sail spacecraft carried the ALADDIN large area dust detector array to study large meteoroids between the Earth and Venus orbits. Yano et al. directly detected both the Earth's and Venus' MMRs dust structures, being consistent with numerical simulations that predict the existence of such local enhancements of dust distribution around these terrestrial planets, as well as Neptune. JAXA's Solar Power Sail mission plans to carry even larger dust detector inherited the technology onboard IKAROS, namely ALADDIN-2 in order to search for such MMRs in the Mars and Jupiter orbits, as predicted by Kuchner et al.(2000), in addition to make a continuous measurement of large dust flux from 1.0 to 5.2 AU crossing the main asteroid belt up to Jupiter Trojan region. It is also noted that recent reanalysis of the Pioneer 10 and 11 photo polarimeter data suggests a small enhancement of the brightness towards the anti-solar direction near Jupiter the largest planet of our Solar System, implying a possible existence of a dust belt related to the planet. The spatial density of dust particles directly measured by the ALADDIN-2 will provide a more conclusive and direct proof due to

  2. Eradication of elephant ear mites (Loxoanoetus bassoni) in two African elephants (Loxodonta africana).

    PubMed

    Wyatt, Jeff; DiVincenti, Louis

    2012-03-01

    Elephant ear mites, not previously described in North America, were eradicated in two African elephants (Loxodonta africana) after six otic instillations of ivermectin at 2-wk intervals. The microscopic examination of a clear, mucoid discharge collected from the external ear canals of two wild-born African elephants housed in a New York State zoo for 25 yr revealed live mites (Loxoaneotus bassoni). The cytologic examination demonstrated no evidence of inflammation or infection. Both elephants were asymptomatic with normal hemograms and serum chemistry panels. A diagnosis of otoacariasis was made. Each elephant was treated six times with 5 ml of 1% ivermectin syrup instilled in each ear canal once every 2 wk. Microscopic examinations of clear mucus collected from each elephant's ear canals 9 days after the first instillation of ivermectin were negative for any life stages of ear mites. Microscopic examinations of mucus collected from both elephants' ear canals at 6, 11, and 16 wk, as well as annually post-treatment for 7 yr, confirmed eradication of the ear mites. The L. bassoni ear mite was first identified in the external ear canals of wild, asymptomatic, lesion-free, African elephants culled in Kruger National Park in South Africa. However, a new species in the same genus of mites (Loxoanoetus lenae) was identified at the necropsy of an 86-yr-old Asian elephant (Elephas maximus) living in a circus in Australia. The autopsy revealed a marked, ballooning distension of bone around the left external acoustic meatus, suggestive of mite-induced otitis externa, as seen in cattle infested with ear mites (Raillieta auris). Elephant health care providers should identify the prevalence of, and consider treatment of, elephants in their care infested with ear mites, given the possible risk for adverse health effects.

  3. Exceptionally High Levels of Genetic Diversity in Wheat Curl Mite (Acari: Eriophyidae) Populations from Turkey.

    PubMed

    Szydło, W; Hein, G; Denizhan, E; Skoracka, A

    2015-08-01

    Recent research on the wheat curl mite species complex has revealed extensive genetic diversity that has distinguished several genetic lineages infesting bread wheat (Triticum aestivum L.) and other cereals worldwide. Turkey is the historical region of wheat and barley (Hordeum vulgare L.) domestication and diversification. The close relationship between these grasses and the wheat curl mite provoked the question of the genetic diversity of the wheat curl mite in this region. The scope of the study was to investigate genetic differentiation within the wheat curl mite species complex on grasses in Turkey. Twenty-one wheat curl mite populations from 16 grass species from nine genera (Agropyron sp., Aegilops sp., Bromus sp., Elymus sp., Eremopyrum sp., Hordeum sp., Poa sp., Secale sp., and Triticum sp.) were sampled in eastern and southeastern Turkey for genetic analyses. Two molecular markers were amplified: the cytochrome oxidase subunit I coding region of mtDNA (COI) and the D2 region of 28S rDNA. Phylogenetic analyses revealed high genetic variation of the wheat curl mite in Turkey, primarily on Bromus and Hordeum spp., and exceptionally high diversity of populations associated with bread wheat. Three wheat-infesting wheat curl mite lineages known to occur on other continents of the world, including North and South America, Australia and Europe, were found in Turkey, and at least two new genetic lineages were discovered. These regions of Turkey exhibit rich wheat curl mite diversity on native grass species. The possible implications for further studies on the wheat curl mite are discussed. PMID:26470350

  4. Exceptionally High Levels of Genetic Diversity in Wheat Curl Mite (Acari: Eriophyidae) Populations from Turkey.

    PubMed

    Szydło, W; Hein, G; Denizhan, E; Skoracka, A

    2015-08-01

    Recent research on the wheat curl mite species complex has revealed extensive genetic diversity that has distinguished several genetic lineages infesting bread wheat (Triticum aestivum L.) and other cereals worldwide. Turkey is the historical region of wheat and barley (Hordeum vulgare L.) domestication and diversification. The close relationship between these grasses and the wheat curl mite provoked the question of the genetic diversity of the wheat curl mite in this region. The scope of the study was to investigate genetic differentiation within the wheat curl mite species complex on grasses in Turkey. Twenty-one wheat curl mite populations from 16 grass species from nine genera (Agropyron sp., Aegilops sp., Bromus sp., Elymus sp., Eremopyrum sp., Hordeum sp., Poa sp., Secale sp., and Triticum sp.) were sampled in eastern and southeastern Turkey for genetic analyses. Two molecular markers were amplified: the cytochrome oxidase subunit I coding region of mtDNA (COI) and the D2 region of 28S rDNA. Phylogenetic analyses revealed high genetic variation of the wheat curl mite in Turkey, primarily on Bromus and Hordeum spp., and exceptionally high diversity of populations associated with bread wheat. Three wheat-infesting wheat curl mite lineages known to occur on other continents of the world, including North and South America, Australia and Europe, were found in Turkey, and at least two new genetic lineages were discovered. These regions of Turkey exhibit rich wheat curl mite diversity on native grass species. The possible implications for further studies on the wheat curl mite are discussed.

  5. Revealing the sub-AU asymmetries of the inner dust rim in the disk around the Herbig Ae star R Coronae Austrinae

    NASA Astrophysics Data System (ADS)

    Kraus, S.; Hofmann, K.-H.; Malbet, F.; Meilland, A.; Natta, A.; Schertl, D.; Stee, P.; Weigelt, G.

    2009-12-01

    models we derive the location of the dust sublimation radius (~0.4 AU), the disk inclination angle (~35°), and a north-south disk orientation (PA ~ 180-190°). Our curved puffed-up rim model can reproduce reasonably well the interferometric observables and the SED and suggests a luminosity of ~29 L⊙ and the presence of relatively large (⪆1.2 μm) Silicate dust grains. Our study also reveals discrepancies between the measured interferometric observables and the puffed-up inner rim models, providing important constraints for future refinements of these theoretical models. Perpendicular to the disk, two bow shock-like structures appear in the associated reflection nebula NGC 6729, suggesting that the detected sub-AU size disk is the driving engine of a large-scale outflow. Conclusions: Detecting, for the first time, strong non-localized asymmetries in the inner regions of a Herbig Ae disk, our study supports the existence of a puffed-up inner rim in YSO disks. Based on observations made with ESO telescopes at the La Silla Paranal Observatory under programme IDs 079.D-0370(A), 081.C-0272(A,B,C), and 081.C-0321(A).

  6. Ubiquity and diversity of human-associated Demodex mites.

    PubMed

    Thoemmes, Megan S; Fergus, Daniel J; Urban, Julie; Trautwein, Michelle; Dunn, Robert R

    2014-01-01

    Demodex mites are a group of hair follicle and sebaceous gland-dwelling species. The species of these mites found on humans are arguably the animals with which we have the most intimate interactions. Yet, their prevalence and diversity have been poorly explored. Here we use a new molecular method to assess the occurrence of Demodex mites on humans. In addition, we use the 18S rRNA gene (18S rDNA) to assess the genetic diversity and evolutionary history of Demodex lineages. Within our samples, 100% of people over 18 years of age appear to host at least one Demodex species, suggesting that Demodex mites may be universal associates of adult humans. A phylogenetic analysis of 18S rDNA reveals intraspecific structure within one of the two named human-associated Demodex species, D. brevis. The D. brevis clade is geographically structured, suggesting that new lineages are likely to be discovered as humans from additional geographic regions are sampled.

  7. Ubiquity and Diversity of Human-Associated Demodex Mites

    PubMed Central

    Thoemmes, Megan S.; Fergus, Daniel J.; Urban, Julie; Trautwein, Michelle; Dunn, Robert R.

    2014-01-01

    Demodex mites are a group of hair follicle and sebaceous gland-dwelling species. The species of these mites found on humans are arguably the animals with which we have the most intimate interactions. Yet, their prevalence and diversity have been poorly explored. Here we use a new molecular method to assess the occurrence of Demodex mites on humans. In addition, we use the 18S rRNA gene (18S rDNA) to assess the genetic diversity and evolutionary history of Demodex lineages. Within our samples, 100% of people over 18 years of age appear to host at least one Demodex species, suggesting that Demodex mites may be universal associates of adult humans. A phylogenetic analysis of 18S rDNA reveals intraspecific structure within one of the two named human-associated Demodex species, D. brevis. The D. brevis clade is geographically structured, suggesting that new lineages are likely to be discovered as humans from additional geographic regions are sampled. PMID:25162399

  8. Dust Storm

    Atmospheric Science Data Center

    2013-04-16

    article title:  Massive Dust Storm over Australia     View ... at JPL September 22, 2009 - Massive dust storm over Australia. project:  MISR category:  ... Sep 22, 2009 Images:  Dust Storm location:  Australia and New Zealand ...

  9. In vitro efficacy of ByeMite and Mite-Stop on developmental stages of the red chicken mite Dermanyssus gallinae.

    PubMed

    Abdel-Ghaffar, Fathy; Semmler, Margit; Al-Rasheid, Khaled; Mehlhorn, Heinz

    2009-10-01

    The present in vitro study shows the efficacy of two antimite products (ByeMite = phoxim, Mite-Stop = neem seed extract) against all developing stages of the important red chicken mite Dermanyssus gallinae (obtained at two farms in France and Germany). While permanent contact with the active compound led to an efficacy of 100% in the case of Mite-Stop on mites in both farms, there was only a 96.2% killing effect of ByeMite on the mites of the French farm. Even short contacts of only 4 s killed 100% of mites in the case of Mite-Stop at the French farm and only 84.5% in the German farm. ByeMite, on the other hand, killed only 27.8% (Germany) and 30% (France) when mites got the chance to escape from the treated grounds to untreated ones. When using only the half doses of both products, Mite-Stop(R) still reached, after permanent contact, 100% activity on the German farm and 98.2% in France, while ByeMite killed 93.8% (Germany) and 90.6% (France). Short contact to half doses of course reduced the activity of both products (Mite-Stop = 59.3% in France, 22.1% in Germany; ByeMite = 28.8% in France, 18.8% in Germany). With respect to the fumigant activity of the products, the strains of D. gallinae reacted differently. While Mite-Stop(R) showed a clear fumigant activity in the case of the German mites, this product did not affect the French mites by air distribution, neither did ByeMite in both cases. Therefore, mites have to come in contact with both products. Against Mite-Stop, there was apparently no resistance and low doses have high efficacy after even short contacts, which regularly occur in a treated stable, where mites have the chance to leave treated places to untreated hidden spots.

  10. Study of Demodex mites: Challenges and Solutions.

    PubMed

    Lacey, N; Russell-Hallinan, A; Powell, F C

    2016-05-01

    Demodex mites are the largest and most complex organisms of the skin microflora. How they interact with the innate and adaptive immune systems is unknown. Their potential to have a pathogenic role in the causation of human skin disorders causes continued speculation. With growing interest in the microflora of human skin and its relevance to cutaneous health, the role of Demodex mites needs to be better understood. The main challenges facing scientists investigating the role of these organisms and possible solutions are reviewed under the following headings: (1) Determining the mite population in skin, (2) Transporting, extracting and imaging live mites, (3) Maintaining mites viable ex vivo and (4) Establishing methods to determine the immune response to Demodex mites and their internal contents. PMID:26695086

  11. [Dermatitis caused by the tropical rat mite (Ornithonyssus bacoti) in Switzerland. Case report].

    PubMed

    Mumcuoglu, Y; Buchheim, E

    1983-05-28

    The tropical rat mite, Ornithonyssus bacoti, has been detected in Switzerland for the first time in 3 patients suffering from a small papulous dermatitis. The lesions, distributed over the whole body, were especially intense on the arms and legs. The sting of O. bacoti was always very painful and the itching lasted for several weeks. The parasites were found on the skin of the patients, on one rat caught near the workroom, and in dust samples collected from the infested site. PMID:6879132

  12. terMITEs: miniature inverted-repeat transposable elements (MITEs) in the termite genome (Blattodea: Termitoidae).

    PubMed

    Luchetti, Andrea

    2015-08-01

    Transposable elements (TEs) are discrete DNA sequences which are able to replicate and jump into different genomic locations. Miniature inverted-repeats TEs (MITEs) are non-autonomous DNA elements whose origin is still poorly understood. Recently, some MITEs were found to contain core repeats that can be arranged in tandem arrays; in some instances, these arrays have even given rise to satellite DNAs in the (peri)centromeric region of the host chromosomes. I report the discovery and analysis of three new MITEs found in the genome of several termite species (hence the name terMITEs) in two different families. For two of the MITEs (terMITE1-Tc1/mariner superfamily; terMITE2-piggyBac superfamily), evidence of past mobility was retrieved. Moreover, these two MITEs contained core repeats, 16 bp and 114 bp long respectively, exhibiting copy number variation. In terMITE2, the tandem duplication appeared associated with element degeneration, in line with a recently proposed evolutionary model on MITEs and the origin of tandem arrays. Concerning their genomic distribution, terMITE1 and terMITE3 appeared more frequently inserted close to coding regions while terMITE2 was mostly associated with TEs. Although MITEs are commonly distributed in coding regions, terMITE2 distribution is in line with that of other insects' piggyBac-related elements and of other small TEs found in termite genomes. This has been explained through insertional preference rather than through selective processes. Data presented here add to the knowledge on the poorly exploited polyneopteran genomes and will provide an interesting framework in which to study TEs' evolution and host's life history traits.

  13. Birth of Three Stowaway-like MITE Families via Microhomology-Mediated Miniaturization of a Tc1/Mariner Element in the Yellow Fever Mosquito

    PubMed Central

    Yang, Guojun; Fattash, Isam; Lee, Chia-Ni; Liu, Kun; Cavinder, Brad

    2013-01-01

    Eukaryotic genomes contain numerous DNA transposons that move by a cut-and-paste mechanism. The majority of these elements are self-insufficient and dependent on their autonomous relatives to transpose. Miniature inverted repeat transposable elements (MITEs) are often the most numerous nonautonomous DNA elements in a higher eukaryotic genome. Little is known about the origin of these MITE families as few of them are accompanied by their direct ancestral elements in a genome. Analyses of MITEs in the yellow fever mosquito identified its youngest MITE family, designated as Gnome, that contains at least 116 identical copies. Genome-wide search for direct ancestral autonomous elements of Gnome revealed an elusive single copy Tc1/Mariner-like element, named as Ozma, that encodes a transposase with a DD37E triad motif. Strikingly, Ozma also gave rise to two additional MITE families, designated as Elf and Goblin. These three MITE families were derived at different times during evolution and bear internal sequences originated from different regions of Ozma. Upon close inspection of the sequence junctions, the internal deletions during the formation of these three MITE families always occurred between two microhomologous sites (6–8 bp). These results suggest that multiple MITE families may originate from a single ancestral autonomous element, and formation of MITEs can be mediated by sequence microhomology. Ozma and its related MITEs are exceptional candidates for the long sought-after endogenous active transposon tool in genetic control of mosquitoes. PMID:24068652

  14. Diarrhea and acaroid mites: A clinical study

    PubMed Central

    Li, Chao-Pin; Cui, Yu-Bao; Wang, Jian; Yang, Qing-Gui; Tian, Ye

    2003-01-01

    AIM: To explore the characteristics of diarrhea caused by acaroid mites. METHODS: Acaroid mites in fresh stools of 241 patients with diarrhea were separated by flotation in saturated saline. Meanwhile, skin prick test, total IgE and mite-specific IgE were detected in all patients. RESULTS: The total positive rate of mites in stool samples of the patients was 17.01% (41/241), the positive rates of mites in male and female patients were 15.86% (23/145) and 18.75% (18/96), respectively, without significant difference (P > 0.05). The percentage of skin prick test as" +++", "++", "+", and "-" was 9.13% (22/241), 7.47% (18/241), 5.81% (14/241), 4.98% (12/241) and 72.61% (175/241), respectively. The serum levels of total IgE, mite-specific IgE in patients with and without mites in stool samples were (165.72 ± 78.55) IU/ml, (132.44 ± 26.80) IU/mL and (145.22 ± 82.47) IU/ml, (67.35 ± 45.28) IU/ml, respectively, with significant difference (P < 0.01). The positive rate of mites in stool samples in staffs working in traditional Chinese medicine storehouses or rice storehouses (experimental group) was 26.74% (23/86), which was significantly higher than that (11.61%, 18/155) in people engaged in other professions (χ2 = 8.97, P < 0.01). CONCLUSION: Acaroid mites cause diarrhea and increase serum levels of total IgE and mite-specific IgE of patients, and the prevalence of diarrhea caused by acaroid mites is associated with occupations rather than the gender of patients. PMID:12854179

  15. Protoplanetary Dust

    NASA Astrophysics Data System (ADS)

    Apai, Dániel; Lauretta, Dante S.

    2010-01-01

    Preface; 1. Planet formation and protoplanetary dust Daniel Apai and Dante Lauretta; 2. The origins of protoplanetary dust and the formation of accretion disks Hans-Peter Gail and Peter Hope; 3. Evolution of protoplanetary disk structures Fred Ciesla and Cornelius P. Dullemond; 4. Chemical and isotopic evolution of the solar nebula and protoplanetary disks Dmitry Semenov, Subrata Chakraborty and Mark Thiemens; 5. Laboratory studies of simple dust analogs in astrophysical environments John R. Brucato and Joseph A. Nuth III; 6. Dust composition in protoplanetaty dust Michiel Min and George Flynn; 7. Dust particle size evolution Klaus M. Pontoppidan and Adrian J. Brearly; 8. Thermal processing in protoplanetary nebulae Daniel Apai, Harold C. Connolly Jr. and Dante S. Lauretta; 9. The clearing of protoplanetary disks and of the protosolar nebula Ilaira Pascucci and Shogo Tachibana; 10. Accretion of planetesimals and the formation of rocky planets John E. Chambers, David O'Brien and Andrew M. Davis; Appendixes; Glossary; Index.

  16. Protoplanetary Dust

    NASA Astrophysics Data System (ADS)

    Apai, D.´niel; Lauretta, Dante S.

    2014-02-01

    Preface; 1. Planet formation and protoplanetary dust Daniel Apai and Dante Lauretta; 2. The origins of protoplanetary dust and the formation of accretion disks Hans-Peter Gail and Peter Hope; 3. Evolution of protoplanetary disk structures Fred Ciesla and Cornelius P. Dullemond; 4. Chemical and isotopic evolution of the solar nebula and protoplanetary disks Dmitry Semenov, Subrata Chakraborty and Mark Thiemens; 5. Laboratory studies of simple dust analogs in astrophysical environments John R. Brucato and Joseph A. Nuth III; 6. Dust composition in protoplanetaty dust Michiel Min and George Flynn; 7. Dust particle size evolution Klaus M. Pontoppidan and Adrian J. Brearly; 8. Thermal processing in protoplanetary nebulae Daniel Apai, Harold C. Connolly Jr. and Dante S. Lauretta; 9. The clearing of protoplanetary disks and of the protosolar nebula Ilaira Pascucci and Shogo Tachibana; 10. Accretion of planetesimals and the formation of rocky planets John E. Chambers, David O'Brien and Andrew M. Davis; Appendixes; Glossary; Index.

  17. Intergalactic Dust

    NASA Astrophysics Data System (ADS)

    Li, A.

    2002-12-01

    We study the composition and sizes of intergalactic dust based on the expulsion of interstellar dust from the galactic disk. Interstellar grains in the Galactic disk are modelled as a mixture of amorphous silicate dust and carbonaceous dust consisting of polycyclic aromatic hydrocarbon (PAH) molecules and larger graphitic grains (Li & Draine 2001) with size distributions like those of the Milky Way dust (Weingartner & Draine 2001). We model their dynamic evolution in terms of the collective effects caused by (1) radiative acceleration, (2) gravitational attraction, (3) gas drag, (4) thermal sputtering, and (5) Lorenz force from the galactic magnetic field (Ferrara et al. 1991). Radiation pressure from the stellar disk exerts an upward force on dust grains and may ultimately expel them out of the entire galaxy. Gravitational force from the stellar, dust and gas disk as well as the dark matter halo exerts a downward force. Thermal sputtering erodes all grains to some degree but more efficiently destroys small grains. This, together with the fact that (1) very small grains (with small radiation pressure efficiencies) are not well coupled to starlight; (2) for large grains the radiative force to the gravitational force is approximately inversely proportional to grain size, acts as a size ``filter'' for dust leaking into the intergalactic space. Since the radiation pressure efficiency and the grain destruction rate are sensitive to dust composition, the relative importance of carbon dust compared to silicate dust expelled into the intergalactic space differs from that in the galactic plane. We derive the size distributions of both silicate and carbonaceous dust finally getting into the intergalactic space and obtain an intergalactic extinction curve. The predicted intergalactic infrared emission spectrum is calculated. References: Ferrara, A., Ferrini, F., Franco, J., & Barsella, B. 1991, ApJ, 381, 137 Li, A., & Draine, B.T. 2001, ApJ, 554, 778 Weingartner, J

  18. House dust in seven Danish offices

    NASA Astrophysics Data System (ADS)

    Mølhave, L.; Schneider, T.; Kjærgaard, S. K.; Larsen, L.; Norn, S.; Jørgensen, O.

    Floor dust from Danish offices was collected and analyzed. The dust was to be used in an exposure experiment. The dust was analyzed to show the composition of the dust which can be a source of airborne dust indoors. About 11 kg of dust from vacuum cleaner bags from seven Danish office buildings with about 1047 occupants (12 751 m 2) was processed according to a standardized procedure yielding 5.5 kg of processed bulk dust. The bulk dust contained 130.000-160.000 CFU g -1 microorganisms and 71.000-90.000 CFU g -1 microfungi. The content of culturable microfungi was 65-123 CFU 30 g -1 dust. The content of endotoxins ranged from 5.06-7.24 EU g -1 (1.45 ng g -1 to 1.01 ng g -1). Allergens (ng g -1) were from 147-159 (Mite), 395-746 (dog) and 103-330 (cat). The macro molecular organic compounds (the MOD-content) varied from 7.8-9.8 mg g -1. The threshold of release of histamine from basophil leukocytes provoked by the bulk dust was between 0.3 and 1.0 mg ml -1. The water content was 2% (WGT) and the organic fraction 33%. 6.5-5.9% (dry) was water soluble. The fiber content was less than 0.2-1.5% (WGT) and the desorbable VOCs was 176-319 μg g -1. Most of the VOC were aldehydes. However, softeners for plastic (DBP and DEHP) were present. The chemical composition includes human and animal skin fragments, paper fibers, glass wool, wood and textilefibers and inorganic and metal particles. The sizes ranged from 0.001-1 mm and the average specific density was 1.0 g m -3. The bulk dust was resuspended and injected into an exposure chamber. The airborne dust was sampled and analyzed to illustrate the exposures that can result from sedimented dirt and dust. The airborne dust resulting from the bulk dust reached concentrations ranging from 0.26-0.75 mg m -3 in average contained 300-170 CFU m -3. The organic fraction was from 55-70% and the water content about 2.5% (WGT). The content of the dust was compared to the similar results reported in the literature and its toxic potency is

  19. Intensity of parasitic mite infection decreases with hibernation duration of the host snail.

    PubMed

    Haeussler, E M; Pizá, J; Schmera, D; Baur, B

    2012-07-01

    Temperature can be a limiting factor on parasite development. Riccardoella limacum, a haematophagous mite, lives in the mantle cavity of helicid land snails. The prevalence of infection by R. limacum in populations of the land snail Arianta arbustorum is highly variable (0-78%) in Switzerland. However, parasitic mites do not occur in host populations at altitudes of 1290 m or higher. It has been hypothesized that the host's hibernation period might be too long at high elevations for mites and their eggs to survive. To test this hypothesis, we experimentally infected snails and allowed them to hibernate at 4°C for periods of 4-7 months. Winter survival of host snails was negatively affected by R. limacum. The intensity of mite infection decreased with increasing hibernation duration. Another experiment with shorter recording intervals revealed that mites do not leave the host when it buries in the soil at the beginning of hibernation. The number of mites decreased after 24 days of hibernation, whereas the number of eggs attached to the lung tissue remained constant throughout hibernation. Thus, R. limacum survives the winter in the egg stage in the host. Low temperature at high altitudes may limit the occurrence of R. limacum.

  20. The marine mites Hyadesia sp. and Copidognathus sp. Associated with the mussel Mytilus galloprovincialis.

    PubMed

    Cáceres-Martínez, J; Vásquez-Yeomans, R; Rentería, Y G; Curiel-Ramírez, S; Valdéz, J A; Rivas, G

    2000-10-01

    Two species of marine mites belonging to the families Hyadesiidae and Halacaridae, Hyadesia sp. and Copidognathus sp., respectively, were found associated with the mussel Mytilus galloprovincialis from Baja California in NW México. The first species was found inside the mussel gut with an intensity ranging from one to six mites per mussel and their prevalence was from 20.0 to 46.7%; this species was also found living free in the sediment at a density of 0.7 mite/100 ml. The second species was found on the mantle and gills of the host with an intensity ranging from one to three mites per host and their prevalence was from 3.3 to 6.7%; this species was abundant (4.5 mites/100 ml) and living free in the sediment around mussel clumps. Hyadesia sp. was found alive and attached in the gut of the mussel. A histological analysis revealed this species in the lumen of intestine surrounded by mucus and attached to the epithelial cells of the intestine, where some disorder of epithelial cells was associated. Moreover, this mite may be encapsulated by hemocytes inside the digestive diverticulum, the reproductive follicle, or the connective tissue surrounding the diverticulum. No damages to branches or gills resulting from the presence of Copidognathus sp. were observed. The results suggest that these mites are occasional invaders of mussels; however, as a result of this infestation, Hyadesia sp. may produce damage in the host's tissues. This is the first record of marine mites inside the gut, reproductive follicles, branches, and mantle of a marine bivalve.

  1. Digestive proteases in bodies and faeces of the two-spotted spider mite, Tetranychus urticae.

    PubMed

    Santamaría, María E; González-Cabrera, Joel; Martínez, Manuel; Grbic, Vojislava; Castañera, Pedro; Díaz, Lsabel; Ortego, Félix

    2015-07-01

    Digestive proteases of the phytophagous mite Tetranychus urticae have been characterised by comparing their activity in body and faecal extracts. Aspartyl, cathepsin B- and L-like and legumain activities were detected in both mite bodies and faeces, with a specific activity of aspartyl and cathepsin L-like proteases about 5- and 2-fold higher, respectively, in mite faeces than in bodies. In general, all these activities were maintained independently of the host plant where the mites were reared (bean, tomato or maize). Remarkably, this is the first report in a phytophagous mite of legumain-like activity, which was characterised for its ability to hydrolyse the specific substrate Z-VAN-AMC, its activation by DTT and inhibition by IAA but not by E-64. Gel free nanoLC-nanoESI-QTOF MS/MS proteomic analysis of mite faeces resulted in the identification of four cathepsins L and one aspartyl protease (from a total of the 29 cathepsins L, 27 cathepsins B, 19 legumains and two aspartyl protease genes identified the genome of this species). Gene expression analysis reveals that four cathepsins L and the aspartyl protease identified in the mite faeces, but also two cathepsins B and two legumains that were not detected in the faeces, were expressed at high levels in the spider mite feeding stages (larvae, nymphs and adults) relative to embryos. Taken together, these results indicate a digestive role for cysteine and aspartyl proteases in T. urticae. The expression of the cathepsins B and L, legumains and aspartyl protease genes analysed in our study increased in female adults after feeding on Arabidopsis plants over-expressing the HvCPI-6 cystatin, that specifically targets cathepsins B and L, or the CMe trypsin inhibitor that targets serine proteases. This unspecific response suggests that in addition to compensation for inhibitor-targeted enzymes, the increase in the expression of digestive proteases in T. urticae may act as a first barrier against ingested plant defensive

  2. China Dust

    Atmospheric Science Data Center

    2013-04-16

    ... SpectroRadiometer (MISR) nadir-camera images of eastern China compare a somewhat hazy summer view from July 9, 2000 (left) with a ... arid and sparsely vegetated surfaces of Mongolia and western China pick up large quantities of yellow dust. Airborne dust clouds from the ...

  3. Dust Storm

    Atmospheric Science Data Center

    2013-04-16

    ... April 11, 2004 (top panels) contrast strongly with the dust storm that swept across Iraq and Saudi Arabia on May 13, 2004 (bottom panels). ... Apr 11 and May 13, 2004 Images:  Dust Storm location:  Middle East thumbnail:  ...

  4. Indoor mite allergens in patients with respiratory allergy living in Porto, Portugal.

    PubMed

    Plácido, J L; Cuesta, C; Delgado, L; da Silva, J P; Miranda, M; Ventas, P; Vaz, M

    1996-09-01

    We investigated the levels of mite allergens (Der p 1, Der f 1, Der 2, and Lep d 1) in dust samples from the homes of 59 patients with asthma, 36 sensitized to house-dust mites (HDM) and 23 to grass pollen (controls), living in Porto, northern Portugal. The relationship between exposure and sensitization to HDM and the influence of housing conditions on mite-allergen levels were also evaluated. Der p 1 (median 9.2 micrograms/g) and Der 2 (4.6 micrograms/g) were the main allergens, while Der f 1 and Lep d 1 levels were always < 1 microgram/g dust and undetectable in 11% and 47% of samples, respectively. All HDM-sensitized asthmatics were exposed to Der p 1 levels > 2 micrograms/g and their homes contained significantly higher levels of Der p 1 (median 12.5 vs 6.4 micrograms/g; P = 0.008) and Der 2 (6.2 vs 3.0 micrograms/g; P = 0.004) when compared to the control group. A significant correlation was observed between the exposure to Der p 1 and the wheal area at skin testing with the Dermatophagoides pteronyssinus (Dp) extract (P = 0.01) as well as with serum specific IgE levels to Dp (P = 0.03). Patients with higher levels of serum specific IgE (> or = 17.5 HRU/ml) were also more frequently exposed to Der p 1 levels > or = 10 micrograms/g (P = 0.002). Old homes, presence of carpets, and signs of dampness were conditions associated with significantly higher levels of mite allergens. In conclusion, we found high levels of Der p 1 and Der 2 particularly in the homes of HDM-sensitized patients and we confirm the relationship between exposure and sensitization to HDM, assessed by both in vivo and in vitro methods. In additional to a favorable outdoor climate, we found in our region housing conditions propitious to mite growth, suggesting that specific geographic characteristics must also be taken into account for the correct planning of mite-avoidance measures. PMID:8899115

  5. Haematophagus Mites in Poultry Farms of Iran

    PubMed Central

    Rahbari, S; Nabian, S; Ronaghi, H

    2009-01-01

    Background: Blood sucking mites are important avian ectoparasites which being found on bird species worldwide. Their presence are problematic for the producers either through potential direct effects on weight gain, egg production, sperm production in roosters or as nuisance pests on worker handle hens and eggs. The aim of this study was pointing out of the status of haematophagus mites. Methods: Eight caged layer and four breeder flocks were visited, monitoring for the presence of chicken mites performed by removing and examining debris from poultry house, infested nesting material collected into zip lock plastic bags and at least 20 birds were also randomly selected to examine the presence of chicken mites. Mites obtained from each population were mounted in Hoyer’s medium on microscope slides and identified. All eight caged layer and four breeder flocks were inspected, which were infested with chicken blood feeding mites. Results: Massive infestations of Dermanyssus gallinae were common with huge numbers of parasites on birds, cages and the conveyor belts for egg. Only one farm from Mazandaran Province was infested to Ornithonyssus bursa. Conclusion: Dermanyssus gallinae was the most prevalent blood feeder mite in the breeder and caged layer flocks in Iran, while O. bursa was reported as a first record, which found only in a breeder flock in Mazanderan Province. It seems that its presence is limited into the area which affected by both warm and humid environmental conditions. PMID:22808378

  6. An opilioacarid mite in Cretaceous Burmese amber

    NASA Astrophysics Data System (ADS)

    Dunlop, Jason A.; de Oliveira Bernardi, Leopoldo Ferreira

    2014-09-01

    A fossil opilioacarid mite (Parasitiformes: Opilioacarida) in Burmese amber is described as ? Opilioacarus groehni sp. nov. This ca. 99 Ma record (Upper Cretaceous: Cenomanian) represents only the third fossil example of this putatively basal mite lineage, the others originating from Eocene Baltic amber (ca. 44-49 Ma). Our new record is not only the oldest record of Opilioacarida, but it is also one of the oldest examples of the entire Parasitiformes clade. The presence of Opilioacarida—potentially Opiloacarus—in the Cretaceous of SE Asia suggests that some modern genus groups were formerly more widely distributed across the northern hemisphere, raising questions about previously suggested Gondwanan origins for these mites.

  7. Light and scanning electron microscopic investigations on MiteStop-treated poultry red mites.

    PubMed

    Locher, Nina; Klimpel, Sven; Abdel-Ghaffar, Fathy; Al Rasheid, Khaled A S; Mehlhorn, Heinz

    2010-07-01

    Recent studies of the neem seed product MiteStop showed that it has a good acaricidal effect against all developmental stages of the poultry red mite, Dermanyssus gallinae. In vitro tests proved an efficacy at direct contact, as well as by fumigant toxicity. Light and scanning electron microscopic (SEM) investigations showed no clear, morphologically visible signs of an effect caused by fumigant toxicity. Direct contact with the neem product, however, seemed to be of great impact. Chicken mites turned dark brown or even black after being treated with the neem product. SEM analysis showed damages along the body surface of the mites. PMID:20563823

  8. Sahara Dust

    Atmospheric Science Data Center

    2013-04-15

    article title:  Casting Light and Shadows on a Saharan Dust Storm   ... CA, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed by NASA's Goddard Space Flight Center, ...

  9. Expression of a barley cystatin gene in maize enhances resistance against phytophagous mites by altering their cysteine-proteases.

    PubMed

    Carrillo, Laura; Martinez, Manuel; Ramessar, Koreen; Cambra, Inés; Castañera, Pedro; Ortego, Felix; Díaz, Isabel

    2011-01-01

    Phytocystatins are inhibitors of cysteine-proteases from plants putatively involved in plant defence based on their capability of inhibit heterologous enzymes. We have previously characterised the whole cystatin gene family members from barley (HvCPI-1 to HvCPI-13). The aim of this study was to assess the effects of barley cystatins on two phytophagous spider mites, Tetranychus urticae and Brevipalpus chilensis. The determination of proteolytic activity profile in both mite species showed the presence of the cysteine-proteases, putative targets of cystatins, among other enzymatic activities. All barley cystatins, except HvCPI-1 and HvCPI-7, inhibited in vitro mite cathepsin L- and/or cathepsin B-like activities, HvCPI-6 being the strongest inhibitor for both mite species. Transgenic maize plants expressing HvCPI-6 protein were generated and the functional integrity of the cystatin transgene was confirmed by in vitro inhibitory effect observed against T. urticae and B. chilensis protein extracts. Feeding experiments impaired on transgenic lines performed with T. urticae impaired mite development and reproductive performance. Besides, a significant reduction of cathepsin L-like and/or cathepsin B-like activities was observed when the spider mite fed on maize plants expressing HvCPI-6 cystatin. These findings reveal the potential of barley cystatins as acaricide proteins to protect plants against two important mite pests.

  10. Dust control for draglines

    SciTech Connect

    Grad, P.

    2009-09-15

    Monitoring dust levels inside draglines reveals room for improvement in how filtration systems are used and maintained. The Australian firm BMT conducted a field test program to measure airflow parameters, dust fallout rates and dust concentrations, inside and outside the machine house, on four draglines and one shovel. The study involved computational fluid dynamics (CFD) simulations. The article describes how the tests were made and gives results. It was not possible to say which of the two main filtration systems currently used on Australian draglines - Dynavane or Floseps - performs better. It would appear that more frequent maintenance and cleaning would increase the overall filtration performance and systems could be susceptible to repeat clogging in a short time. 2 figs., 1 photos.

  11. Direct activation of gelatinase B (MMP-9) by hay dust suspension and different components of organic dust.

    PubMed

    Simonen-Jokinen, Terhi; Maisi, Päivi; Tervahartiala, Taina; McGorum, Bruce; Pirie, Scott; Sorsa, Timo

    2006-02-15

    Matrix metalloproteinases (MMPs) are involved in tissue destruction in allergic airway diseases. We studied the ability of various allergenic substances to directly activate recombinant 92kDa proMMP-9. The substances included hay dust suspension (HDS) and its components (supernatant, particulate matter and wash fluid of particulate matter), storage mite extract and two Aspergillus fumigatus extracts. The allergen suspensions were incubated in vitro with proMMP-9. After incubation the conversion of proMMP-9 to 10kDa lower active forms were studied using gelatin zymography and Western immunoblot quantified by computerized densitometry. All studied allergens except HDS significantly and efficiently activated proMMP-9 as compared to a negative control. At the concentrations employed, the most potent activators were A. fumigatus extracts and mite suspension. The greater potency of mite and fungi as proMMP-9 activators suggests that these allergens may be more damaging to airways even at low concentrations. PMID:16181685

  12. The economic importance of acaricides in the control of phytophagous mites and an update on recent acaricide mode of action research.

    PubMed

    Van Leeuwen, Thomas; Tirry, Luc; Yamamoto, Atsushi; Nauen, Ralf; Dermauw, Wannes

    2015-06-01

    Acaricides are one of the cornerstones of an efficient control program for phytophagous mites. An analysis of the global acaricide market reveals that spider mites such as Tetranychus urticae, Panonychus citri and Panonychus ulmi are by far the most economically important species, representing more than 80% of the market. Other relevant mite groups are false spider mites (mainly Brevipalpus), rust and gall mites and tarsonemid mites. Acaricides are most frequently used in vegetables and fruits (74% of the market), including grape vines and citrus. However, their use is increasing in major crops where spider mites are becoming more important, such as soybean, cotton and corn. As revealed by a detailed case study of the Japanese market, major shifts in acaricide use are partially driven by resistance development and the commercial availability of compounds with novel mode of action. The importance of the latter cannot be underestimated, although some compounds are successfully used for more than 30 years. A review of recent developments in mode of action research is presented, as such knowledge is important for devising resistance management programs. This includes spirocyclic keto-enols as inhibitors of acetyl-CoA carboxylase, the carbazate bifenazate as a mitochondrial complex III inhibitor, a novel class of complex II inhibitors, and the mite growth inhibitors hexythiazox, clofentezine and etoxazole that interact with chitin synthase I.

  13. The economic importance of acaricides in the control of phytophagous mites and an update on recent acaricide mode of action research.

    PubMed

    Van Leeuwen, Thomas; Tirry, Luc; Yamamoto, Atsushi; Nauen, Ralf; Dermauw, Wannes

    2015-06-01

    Acaricides are one of the cornerstones of an efficient control program for phytophagous mites. An analysis of the global acaricide market reveals that spider mites such as Tetranychus urticae, Panonychus citri and Panonychus ulmi are by far the most economically important species, representing more than 80% of the market. Other relevant mite groups are false spider mites (mainly Brevipalpus), rust and gall mites and tarsonemid mites. Acaricides are most frequently used in vegetables and fruits (74% of the market), including grape vines and citrus. However, their use is increasing in major crops where spider mites are becoming more important, such as soybean, cotton and corn. As revealed by a detailed case study of the Japanese market, major shifts in acaricide use are partially driven by resistance development and the commercial availability of compounds with novel mode of action. The importance of the latter cannot be underestimated, although some compounds are successfully used for more than 30 years. A review of recent developments in mode of action research is presented, as such knowledge is important for devising resistance management programs. This includes spirocyclic keto-enols as inhibitors of acetyl-CoA carboxylase, the carbazate bifenazate as a mitochondrial complex III inhibitor, a novel class of complex II inhibitors, and the mite growth inhibitors hexythiazox, clofentezine and etoxazole that interact with chitin synthase I. PMID:26047107

  14. The role of mites in insect-fungus associations.

    PubMed

    Hofstetter, R W; Moser, J C

    2014-01-01

    The interactions among insects, mites, and fungi are diverse and complex but poorly understood in most cases. Associations among insects, mites, and fungi span an almost incomprehensible array of ecological interactions and evolutionary histories. Insects and mites often share habitats and resources and thus interact within communities. Many mites and insects rely on fungi for nutrients, and fungi benefit from them with regard to spore dispersal, habitat provision, or nutrient resources. Mites have important impacts on community dynamics, ecosystem processes, and biodiversity within many insect-fungus systems. Given that mites are understudied but highly abundant, they likely have bigger, more important, and more widespread impacts on communities than previously recognized. We describe mutualistic and antagonistic effects of mites on insect-fungus associations, explore the processes that underpin ecological and evolutionary patterns of these multipartite communities, review well-researched examples of the effects of mites on insect-fungus associations, and discuss approaches for studying mites within insect-fungus communities.

  15. Virulence and site of infection of the fungus, Hirsutella thompsonii, to the honey bee ectoparasitic mite, Varroa destructor.

    PubMed

    Peng, Christine Y S; Zhou, Xinsheng; Kaya, Harry K

    2002-11-01

    The Varroa mite, Varroa destructor, is recognized as the most serious pest of both managed and feral Western honey bee (Apis mellifera) in the world. The mite has developed resistance to fluvalinate, an acaricide used to control it in beehives, and fluvalinate residues have been found in the beeswax, necessitating an urgent need to find alternative control measures to suppress this pest. Accordingly, we investigated the possibility of using the fungus, Hirsutella thompsonii, as a biocontrol agent of the Varroa mite. Among the 9 isolates of H. thompsonii obtained from the University of Florida and the USDA, only the 3 USDA isolates (ARSEF 257, 1947 and 3323) were infectious to the Varroa mite in laboratory tests. The mite became infected when it was allowed to walk on a sporulating H. thompsonii culture for 5 min. Scanning electron micrographs revealed that the membranous arolium of the mite leg sucker is the focus of infection where the fungal conidia adhered and germinated. The infected mites died from mycosis, with the lethal times to kill 50% (LT(50)s) dependent on the fungal isolates. Thus, the LT(50)s were 52.7, 77.2, and 96.7h for isolates 3323, 257, and 1947, respectively. Passage of H. thompsonii through Varroa mite three times significantly reduced the LT(50)s of isolates 257 and 1947 (P<0.05) but not the LT(50) of isolate 3323. The fungus did not infect the honey bee in larval, prepupal, pupal, and adult stages under our laboratory rearing conditions. Our encouraging results suggest that some isolates of H. thompsonii have the potential to be developed as a biocontrol agent for V. destructor. However, fungal infectivity against the mites under beehive conditions needs to be studied before any conclusion can be made.

  16. Contrasting evolutionary patterns and target specificities among three Tourist-like MITE families in the maize genome.

    PubMed

    Zerjal, Tatiana; Joets, Johann; Alix, Karine; Grandbastien, Marie-Angèle; Tenaillon, Maud I

    2009-09-01

    Miniature inverted-repeat transposable elements (MITEs) are short, non autonomous DNA elements that are widespread and abundant in plant genomes. The high sequence and size conservation observed in many MITE families suggest that they have spread recently throughout their respective host genomes. Here we present a maize genome wide analysis of three Tourist-like MITE families, mPIF, and two previously uncharacterized families, ZmV1 and Zead8. We undertook a bioinformatic analysis of MITE insertion sites, developed methyl-sensitive transposon display (M-STD) assays to estimate the associated level of CpG methylation at MITE flanking regions, and conducted a population genetics approach to investigate MITE patterns of expansion. Our results reveal that the three MITE families insert into genomic regions that present specific molecular features: they are preferentially AT rich, present low level of cytosine methylation as compared to the LTR retrotransposon Grande, and target site duplications are flanked by large and conserved palindromic sequences. Moreover, the analysis of MITE distances from predicted genes shows that 73% of 263 copies are inserted at less than 5 kb from the nearest predicted gene, and copies from Zead8 family are significantly more abundant upstream of genes. By employing a population genetic approach we identified contrasting patterns of expansion among the three MITE families. All elements seem to have inserted roughly 1 million years ago but ZmV1 and Zead8 families present evidences for activity of several master copies within the last 0.4 Mya.

  17. Skin cross-reactivity between Dermatophagoides pteronyssinus and storage mites in atopic children.

    PubMed

    Sánchez Palacios, A; García Marrero, J A; Limiñana Cañal, J M; Schaman, F; Alonso Bordón, J; Gutiérrez Pérez, A T

    1991-06-01

    In our environment, some children with allergic respiratory pathology do not have as favorable an evolution as expected after three years of immunotherapy with D. pteronyssinus extracts. We believe this is due to the existence of other mites whose antigenic determinants are not present in D. pteronyssinus. The purpose of the present study was to evaluate skin cross-reactivity between Dermatophagoides and storage mites in children with bronchial asthma. Fifty patients were chosen, with a mean age of 7.78 +/- 2.98 years and a range of 3-14 years. There were 38 boys (76%) and 12 girls (24%) with rhinitis and bronchial asthma. All patients had skin tests and prick tests with the following extracts performed on them: house dust (HD), Dermatophagoides farinae (DFA), Dermatophagoides pteronyssinus (DPT), Acarus siro (AS), Glycyphagus domesticus (GD), Lepidoglyphus destructor (LD), Tyrophagus putrescentiae (TP), with negative and positive controls. The areas of the papulae were evaluated in crosses, according to the size of the histamine and using computerized papulometry, using the Kurta series one graphic tablet with one resolution of 200 points per inch. The data were processed with the "Image-pro" analysis image program. The following conclusions were obtained from our study: 1) No case of skin sensitization to storage mites was found in any of our 50 patients, without house dust and/or Dermatophagoides mites also being present. 2) The greatest skin response with regard to histamine was found for DFA (52%), DPT (44%), HD (22%), GD (10%), AS (4%) and GF (2%).(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Genotypic variability and relationships between mite infestation levels, mite damage, grooming intensity, and removal of Varroa destructor mites in selected strains of worker honey bees (Apis mellifera L.).

    PubMed

    Guzman-Novoa, Ernesto; Emsen, Berna; Unger, Peter; Espinosa-Montaño, Laura G; Petukhova, Tatiana

    2012-07-01

    The objective of this study was to demonstrate genotypic variability and analyze the relationships between the infestation levels of the parasitic mite Varroa destructor in honey bee (Apis mellifera) colonies, the rate of damage of fallen mites, and the intensity with which bees of different genotypes groom themselves to remove mites from their bodies. Sets of paired genotypes that are presumably susceptible and resistant to the varroa mite were compared at the colony level for number of mites falling on sticky papers and for proportion of damaged mites. They were also compared at the individual level for intensity of grooming and mite removal success. Bees from the "resistant" colonies had lower mite population rates (up to 15 fold) and higher percentages of damaged mites (up to 9 fold) than bees from the "susceptible" genotypes. At the individual level, bees from the "resistant" genotypes performed significantly more instances of intense grooming (up to 4 fold), and a significantly higher number of mites were dislodged from the bees' bodies by intense grooming than by light grooming (up to 7 fold) in all genotypes. The odds of mite removal were high and significant for all "resistant" genotypes when compared with the "susceptible" genotypes. The results of this study strongly suggest that grooming behavior and the intensity with which bees perform it, is an important component in the resistance of some honey bee genotypes to the growth of varroa mite populations. The implications of these results are discussed.

  19. Novel scabies mite serpins inhibit the three pathways of the human complement system.

    PubMed

    Mika, Angela; Reynolds, Simone L; Mohlin, Frida C; Willis, Charlene; Swe, Pearl M; Pickering, Darren A; Halilovic, Vanja; Wijeyewickrema, Lakshmi C; Pike, Robert N; Blom, Anna M; Kemp, David J; Fischer, Katja

    2012-01-01

    Scabies is a parasitic infestation of the skin by the mite Sarcoptes scabiei that causes significant morbidity worldwide, in particular within socially disadvantaged populations. In order to identify mechanisms that enable the scabies mite to evade human immune defenses, we have studied molecules associated with proteolytic systems in the mite, including two novel scabies mite serine protease inhibitors (SMSs) of the serpin superfamily. Immunohistochemical studies revealed that within mite-infected human skin SMSB4 (54 kDa) and SMSB3 (47 kDa) were both localized in the mite gut and feces. Recombinant purified SMSB3 and SMSB4 did not inhibit mite serine and cysteine proteases, but did inhibit mammalian serine proteases, such as chymotrypsin, albeit inefficiently. Detailed functional analysis revealed that both serpins interfered with all three pathways of the human complement system at different stages of their activation. SMSB4 inhibited mostly the initial and progressing steps of the cascades, while SMSB3 showed the strongest effects at the C9 level in the terminal pathway. Additive effects of both serpins were shown at the C9 level in the lectin pathway. Both SMSs were able to interfere with complement factors without protease function. A range of binding assays showed direct binding between SMSB4 and seven complement proteins (C1, properdin, MBL, C4, C3, C6 and C8), while significant binding of SMSB3 occurred exclusively to complement factors without protease function (C4, C3, C8). Direct binding was observed between SMSB4 and the complement proteases C1s and C1r. However no complex formation was observed between either mite serpin and the complement serine proteases C1r, C1s, MASP-1, MASP-2 and MASP-3. No catalytic inhibition by either serpin was observed for any of these enzymes. In summary, the SMSs were acting at several levels mediating overall inhibition of the complement system and thus we propose that they may protect scabies mites from complement

  20. Spectral response of spider mite infested cotton: Mite density and miticide rate study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two-spotted spider mites are important pests in many agricultural systems. Spider mites (Acari: Tetranychidae) have been found to cause economic damage in corn, cotton, and sorghum. Adult glass vial bioassays indicate that Temprano™ (abamectin) is the most toxic technical miticide for adult two-spot...

  1. Mitochondrial genome evolution and tRNA truncation in Acariformes mites: new evidence from eriophyoid mites

    PubMed Central

    Xue, Xiao-Feng; Guo, Jing-Feng; Dong, Yan; Hong, Xiao-Yue; Shao, Renfu

    2016-01-01

    The subclass Acari (mites and ticks) comprises two super-orders: Acariformes and Parasitiformes. Most species of the Parasitiformes known retained the ancestral pattern of mitochondrial (mt) gene arrangement of arthropods, and their mt tRNAs have the typical cloverleaf structure. All of the species of the Acariformes known, however, have rearranged mt genomes and truncated mt tRNAs. We sequenced the mt genomes of two species of Eriophyoidea: Phyllocoptes taishanensis and Epitrimerus sabinae. The mt genomes of P. taishanensis and E. sabinae are 13,475 bp and 13,531 bp, respectively, are circular and contain the 37 genes typical of animals; most mt tRNAs are highly truncated in both mites. On the other hand, these two eriophyoid mites have the least rearranged mt genomes seen in the Acariformes. Comparison between eriophyoid mites and other Aacariformes mites showed that: 1) the most recent common ancestor of Acariformes mites retained the ancestral pattern of mt gene arrangement of arthropods with slight modifications; 2) truncation of tRNAs for cysteine, phenylalanine and histidine occurred once in the most recent common ancestor of Acariformes mites whereas truncation of other tRNAs occurred multiple times; and 3) the placement of eriophyoid mites in the order Trombidiformes needs to be reviewed. PMID:26732998

  2. Wheat curl mite and dry bulb mite: untangling a taxonomic conundrum through a multidisciplinary approach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The taxonomy of two economically important eriophyoid species, Aceria tosichella (wheat curl mite, WCM) and A. tulipae (dry bulb mite, DBM), was confounded in the world literature until the late 20th century due to their morphological similarity and ambiguous data from plant-transfer and virus-trans...

  3. Mites and internal parasites associated with the common dung beetle Geotrupes (Anoplotrupes) stercorosus (Hartmann in Scriba, 1791) in Poland.

    PubMed

    Sulgostowska, Teresa; Solarz, Krzysztof; Madej, Grażyna; Klimaszewski, Krzysztof

    2015-12-01

    Common dung beetles collected in the "Sobieski Forest" (eastern border of Warsaw suburbs) were examined for the occurrence and prevalence of infections or infestations with intestinal parasites and phoretic mites in relation to soil characteristics and quality of the forest habitat. Endoparasitic fauna was represented by gregarines Didymophyes paradoxa, microsporidians Plistophora geotrupina and cysticerkoids of 2 tapeworms - Ditestolepis diaphana and Staphylocystis furcate. Prevalence of these infections was higher for beetles collected from rich habitats. Acarofauna was represented by hypopodes of Sancassania geotruporum (Astigmatina, Acaridae) and the following taxa of mesostigmatic mites: Alliphis halleri, Macrocheles glaber, Parasitus coleoptratorum and unidentified juvenile Laelapidae representative. Mites were most abundant in June, July and September. They were only slightly more numerously found on dung beetles from the rich habitats. Nonmetric multidimensional scaling, MDS (2D stress = 0.13) revealed significant similarities in the distribution of mite taxa between poor and rich sites and among the investigated months (June, July and September).

  4. An intensely star-forming galaxy at z ∼ 7 with low dust and metal content revealed by deep ALMA and HST observations

    SciTech Connect

    Ouchi, Masami; Ono, Yoshiaki; Momose, Rieko; Ellis, Richard; Nakanishi, Kouichiro; Kohno, Kotaro; Tamura, Yoichi; Kurono, Yasutaka; Ashby, M. L. N.; Willner, S. P.; Fazio, G. G.; Shimasaku, Kazuhiro; Iono, Daisuke

    2013-12-01

    We report deep ALMA observations complemented by associated Hubble Space Telescope (HST) imaging for a luminous (m {sub UV} = 25) galaxy, 'Himiko', at a redshift of z = 6.595. The galaxy is remarkable for its high star formation rate, 100 M {sub ☉} yr{sup –1}, which has been securely estimated from our deep HST and Spitzer photometry, and the absence of any evidence for strong active galactic nucleus activity or gravitational lensing magnification. Our ALMA observations probe an order of magnitude deeper than previous IRAM observations, yet fail to detect a 1.2 mm dust continuum, indicating a flux of <52 μJy, which is comparable to or weaker than that of local dwarf irregulars with much lower star formation rates. We likewise provide a strong upper limit for the flux of [C II] 158 μm, L{sub [C} {sub II]}<5.4×10{sup 7} L{sub ⊙}, which is a diagnostic of the hot interstellar gas that is often described as a valuable probe for early galaxies. In fact, our observations indicate that Himiko lies off the local L{sub [C} {sub II]}-star formation rate scaling relation by a factor of more than 30. Both aspects of our ALMA observations suggest that Himiko is a unique object with a very low dust content and perhaps nearly primordial interstellar gas. Our HST images provide unique insight into the morphology of this remarkable source, highlighting an extremely blue core of activity and two less extreme associated clumps. Himiko is undergoing a triple major merger event whose extensive ionized nebula of Lyα emitting gas, discovered in our earlier work with Subaru, is powered by star formation and the dense circumgalactic gas. We are likely witnessing an early massive galaxy during a key period of its mass assembly close to the end of the reionization era.

  5. Disseminated mite infection with ocular involvement in a juvenile bald eagle (Haliaeetus leucocephalus).

    PubMed

    Bueno-Padilla, Irene; Klauss, Gia; Gardiner, Chris H; Wuenschmann, Arno

    2012-07-01

    A bald eagle (Haliaeetus leucocephalus) was found unable to fly and was admitted to The Raptor Center (TRC). Major clinical signs were thin body condition and a cardiac arrhythmia. Ten days after admission to TRC, ophthalmic examination revealed multiple, distinct serpiginous lesions of chorioretinal atrophy in the ocular fundus of the right eye (OD). The bird was euthanized because of clinical deterioration and poor prognosis. Mites of an undetermined species were found histologically in the retina, episcleral tissues, lungs, and liver at the postmortem examination. Disseminated mite infection should be considered in the differential diagnosis of serpiginous chorioretinal lesions in bald eagles (H. leucocephalus).

  6. Disseminated mite infection with ocular involvement in a juvenile bald eagle (Haliaeetus leucocephalus).

    PubMed

    Bueno-Padilla, Irene; Klauss, Gia; Gardiner, Chris H; Wuenschmann, Arno

    2012-07-01

    A bald eagle (Haliaeetus leucocephalus) was found unable to fly and was admitted to The Raptor Center (TRC). Major clinical signs were thin body condition and a cardiac arrhythmia. Ten days after admission to TRC, ophthalmic examination revealed multiple, distinct serpiginous lesions of chorioretinal atrophy in the ocular fundus of the right eye (OD). The bird was euthanized because of clinical deterioration and poor prognosis. Mites of an undetermined species were found histologically in the retina, episcleral tissues, lungs, and liver at the postmortem examination. Disseminated mite infection should be considered in the differential diagnosis of serpiginous chorioretinal lesions in bald eagles (H. leucocephalus). PMID:22151197

  7. Inhibitory Properties of Cysteine Protease Pro-Peptides from Barley Confer Resistance to Spider Mite Feeding

    PubMed Central

    Diaz-Mendoza, Mercedes; Martinez, Manuel; Diaz, Isabel

    2015-01-01

    C1A plant cysteine proteases are synthesized as pre-pro-enzymes that need to be processed to become active by the pro-peptide claves off from its cognate enzyme. These pro-sequences play multifunctional roles including the capacity to specifically inhibit their own as well as other C1A protease activities from diverse origin. In this study, it is analysed the potential role of C1A pro-regions from barley as regulators of cysteine proteases in target phytophagous arthropods (coleopteran and acari). The in vitro inhibitory action of these pro-sequences, purified as recombinant proteins, is demonstrated. Moreover, transgenic Arabidopsis plants expressing different fragments of HvPap-1 barley gene containing the pro-peptide sequence were generated and the acaricide function was confirmed by bioassays conducted with the two-spotted spider mite Tetranychus urticae. Feeding trials resulted in a significant reduction of leaf damage in the transgenic lines expressing the pro-peptide in comparison to non-transformed control and strongly correlated with an increase in mite mortality. Additionally, the analysis of the expression levels of a selection of potential mite targets (proteases and protease inhibitors) revealed a mite strategy to counteract the inhibitory activity produced by the C1A barley pro-prodomain. These findings demonstrate that pro-peptides can control mite pests and could be applied as defence proteins in biotechnological systems. PMID:26039069

  8. Intraguild predation between phytoseiid mite species might not be so common.

    PubMed

    Guzmán, C; Sahún, R M; Montserrat, M

    2016-04-01

    It is widely acknowledged that intraguild predation (IGP) occurs frequently between species of phytoseiid mites. However, in the presence of a shared resource many species of phytoseiid mites considerably reduce, or even cease, predation on each other. That being the case, IGP would then be minimal, or non-existent, and its theoretical effects on communities negligible. The aim of this work was two-fold. On the one hand, we aimed at determining the occurrence of IGP between two species of phytoseiid mites that inhabit avocado agro-ecosystems (Euseius stipulatus and E. scutalis) while considering the influence of abiotic conditions. On the other hand, we aimed at evaluating the occurrence of IGP between species of phytoseiid mites through a literature search of studies to determine whether methodologies and results in these papers supported the extended idea of IGP being widespread in the Phytoseiidae family. Our results suggested that in the presence of the shared resource predation on the IG-prey was negligible and both species seem to forage preferentially on pollen. Therefore, the interaction that most likely drives the dynamics of these two species in the field is exploitative resource competition. The literature search revealed that caution should be taken when assuming that IGP between phytoseiid mites is widespread, because only few works used experimental set ups with the adequate array of treatments allowing to assess whether IG-predators fed or not on both the IG-prey and the shared resource. PMID:26715542

  9. Inhibitory properties of cysteine protease pro-peptides from barley confer resistance to spider mite feeding.

    PubMed

    Santamaria, M Estrella; Arnaiz, Ana; Diaz-Mendoza, Mercedes; Martinez, Manuel; Diaz, Isabel

    2015-01-01

    C1A plant cysteine proteases are synthesized as pre-pro-enzymes that need to be processed to become active by the pro-peptide claves off from its cognate enzyme. These pro-sequences play multifunctional roles including the capacity to specifically inhibit their own as well as other C1A protease activities from diverse origin. In this study, it is analysed the potential role of C1A pro-regions from barley as regulators of cysteine proteases in target phytophagous arthropods (coleopteran and acari). The in vitro inhibitory action of these pro-sequences, purified as recombinant proteins, is demonstrated. Moreover, transgenic Arabidopsis plants expressing different fragments of HvPap-1 barley gene containing the pro-peptide sequence were generated and the acaricide function was confirmed by bioassays conducted with the two-spotted spider mite Tetranychus urticae. Feeding trials resulted in a significant reduction of leaf damage in the transgenic lines expressing the pro-peptide in comparison to non-transformed control and strongly correlated with an increase in mite mortality. Additionally, the analysis of the expression levels of a selection of potential mite targets (proteases and protease inhibitors) revealed a mite strategy to counteract the inhibitory activity produced by the C1A barley pro-prodomain. These findings demonstrate that pro-peptides can control mite pests and could be applied as defence proteins in biotechnological systems.

  10. Variability of the honey bee mite Varroa destructor in Serbia, based on mtDNA analysis.

    PubMed

    Gajic, Bojan; Radulovic, Zeljko; Stevanovic, Jevrosima; Kulisic, Zoran; Vucicevic, Milos; Simeunovic, Predrag; Stanimirovic, Zoran

    2013-09-01

    Only two mitochondrial haplotypes (Korea and Japan) of Varroa destructor, the ectoparasitic honey bee mite, are known to be capable of infesting and successfully reproducing in Apis mellifera colonies worldwide. Varroa destructor (then called Varroa jacobsoni) was observed in Serbia for the first time in 1976. In order to obtain insight into the genetic variability of the mites parasitizing A. mellifera we analyzed 45 adult female mites sampled from nine localities dispersed throughout Serbia. Four fragments within cox1, atp6, cox3 and cytb mtDNA genes were sequenced. The Korea haplotype of V. destructor was found to be present at all localities, but also two new haplotypes (Serbia 1 and Peshter 1) were revealed, based on cox1 and cytb sequence variability. The simultaneous occurrence of Korea and Serbia 1 haplotypes was observed at five localities, whereas Peshter 1 haplotype was identifed at only one place.

  11. Histopathological study of the mite biting (Dermanyssus gallinae) in poultry skin

    PubMed Central

    Hobbenaghi, Rahim; Tavassoli, Mousa; Alimehr, Manochehr; Shokrpoor, Sara; Ghorbanzadeghan, Mohammad

    2012-01-01

    The red mite of poultry, Dremanyssus gallinae, is the most important hematophagous ectoparasite of poultry. In this study, pathologic changes of its biting on the poultry skin have been investigated. Thirty-two (Control = 16 and Treatment = 16) four weeks old Ross broilers (308) were infested with the mite on skin of hock joins. Samples were collected after 1, 24, 72 hours and 10 days. The skin samples were fixed in 10% buffered formalin and histological sections were prepared using routine Hematoxylin & Eosin staining method. Results showed that in all cases, except within first hour of infestation, lymphocytic infiltration was always a constant pathologic feature. Necrosis of feather's follicles was a prominent pathologic feature ensued due to vascular disturbances and resulted in loss of feather. Hyperkeratosis, parakeratosis and acanthosis were observed after 72 hours. These findings reveal that mite biting induces local epidermal hyperplasia. PMID:25610570

  12. Histopathological study of the mite biting (Dermanyssus gallinae) in poultry skin.

    PubMed

    Hobbenaghi, Rahim; Tavassoli, Mousa; Alimehr, Manochehr; Shokrpoor, Sara; Ghorbanzadeghan, Mohammad

    2012-01-01

    The red mite of poultry, Dremanyssus gallinae, is the most important hematophagous ectoparasite of poultry. In this study, pathologic changes of its biting on the poultry skin have been investigated. Thirty-two (Control = 16 and Treatment = 16) four weeks old Ross broilers (308) were infested with the mite on skin of hock joins. Samples were collected after 1, 24, 72 hours and 10 days. The skin samples were fixed in 10% buffered formalin and histological sections were prepared using routine Hematoxylin & Eosin staining method. Results showed that in all cases, except within first hour of infestation, lymphocytic infiltration was always a constant pathologic feature. Necrosis of feather's follicles was a prominent pathologic feature ensued due to vascular disturbances and resulted in loss of feather. Hyperkeratosis, parakeratosis and acanthosis were observed after 72 hours. These findings reveal that mite biting induces local epidermal hyperplasia.

  13. Severe ulceronecrotic dermatitis associated with mite infestation in the critically endangered Amargosa vole (Microtus californicus scirpensis).

    PubMed

    Foley, Janet; Branston, Tammy; Woods, Leslie; Clifford, Deana

    2013-08-01

    The entire range of the critically endangered Amargosa vole (Microtus californicus scirpensis) consists of less than 20 km(2) of riparian habitat in the Amargosa River drainage of the Mojave Desert in southern California. In September 2010, deformities on ears and chiggers on the ears and genitalia were detected, with some individuals so severely affected that they were missing ear pinnae altogether. Follow-up trapping was performed to document the presence of mites and mite-associated disease, and molecular characterization was performed on the mites. Of 151 Amargosa voles sampled from February to April of 2011, 60 (39.7%) voles had hard orange mites adhered to some part of their bodies, on ears of 46 (76.7%), on genitalia of 11 (18.3%), and near mammary tissue of 13 (21.7%) voles. Gross lesions were not detected on genitalia, but 47% of all individuals examined showed pinnal lesions and deformities, which included alopecia, swelling, marginal necrosis, and ulceration, as well as scarring, scabbing, and loss of pinna mass covering 25-100% of the pinnae. Biopsies revealed parakeratotic hyperkeratosis and acanthosis with diffuse neutrophilic exocytosis and dense necrotic granulocytes in the epidermis and superficial dermis associated with focal erosion and ulceration. In the underlying dermis, there were dense pleocellular inflammatory cell infiltrates composed primarily of necrotic granulocytes and multifocal hemorrhage. In some samples, mite mouthparts could be seen penetrating the superficial epidermis associated with focal necrosis, and mite fragments were found on the surface epidermis and within hair follicles. Microscopic examination of the mites documented that they were a larval trombiculid in the genus Neotrombicula with anatomical features that most closely resemble Neotrombicula microti, based on scutal shape, setation, and texture. PCR of 2 mite pools (each consisting of 3 mites from an individual animal) amplified 331 bp amplicons, which had 92

  14. First detections of Rickettsia helvetica and R. monacensis in ectoparasitic mites (Laelapidae and Trombiculidae) infesting rodents in south-western Slovakia.

    PubMed

    Miťková, Katarína; Berthová, Lenka; Kalúz, Stanislav; Kazimírová, Mária; Burdová, Lenka; Kocianová, Elena

    2015-07-01

    Information on circulation of rickettsiae between small mammals and their ectoparasitic mites is scarce. In this study, we investigated infestation rates of rodents with mites in some areas of SW Slovakia and the role of mites as possible vectors of pathogenic rickettsiae. A total of 615 rodents of five species were caught during 2010-2012. All individuals were examined for ectoparasites which resulted in 2821 mites belonging to three species of Laelapidae and six species of Trombiculidae. The most common Laelapidae species was Laelaps agilis (81.25 %), followed by Haemogamasus nidi, and Eulaelaps stabularis. Hirsutiella zachvatkini (16.52 %) was the dominant species of the family Trombiculidae. DNA extracted from rodent blood and ectoparasitic mites was examined for the presence of rickettsiae by PCR. By pooling mites, 345 pool samples were created, of which 112 (32.46 %) were found to be positive for the rickettsial DNA. From 487 examined rodent blood samples, rickettsial DNA was found in 46 (9.44 %). Sequencing DNA from the positive blood samples and mites revealed the identity of Rickettsia helvetica and Rickettsia monacensis. The results of the study suggest that ectoparasitic mites may be reservoirs as well as vectors of some pathogenic rickettsiae.

  15. Application of the Phylogenetic Species Concept to Wallemia sebi from House Dust and Indoor Air Revealed by Multi-Locus Genealogical Concordance

    PubMed Central

    Nguyen, Hai D. T.; Jančič, Sašo; Meijer, Martin; Tanney, Joey B.; Zalar, Polona; Gunde-Cimerman, Nina; Seifert, Keith A.

    2015-01-01

    A worldwide survey of Wallemia occurring in house dust and indoor air was conducted. The isolated strains were identified as W. sebi and W. muriae. Previous studies suggested that the W. sebi phylogenetic clade contained cryptic species but conclusive evidence was lacking because only the internal transcribed spacer (ITS) marker was analyzed. The ITS and four protein-coding genes (MCM7, RPB1, RPB2, and TSR1) were sequenced for 85 isolates. Based on an initial neighbor joining analysis of the concatenated genes, W. muriae remained monophyletic but four clades were found in W. sebi, which we designated as W. sebi clades 1, 2, 3, and 4. We hypothesized that these clades represent distinct phylogenetic species within the Wallemia sebi species complex (WSSC). We then conducted multiple phylogenetic analyses and demonstrated genealogical concordance, which supports the existence of four phylogenetic species within the WSSC. Geographically, W. muriae was only found in Europe, W. sebi clade 3 was only found in Canada, W. sebi clade 4 was found in subtropical regions, while W. sebi clade 1 and 2 were found worldwide. Haplotype analysis showed that W. sebi clades 1 and 2 had multiple haplotypes while W. sebi clades 3 and 4 had one haplotype and may have been under sampled. We describe W. sebi clades 2, 3, and 4 as new species in a companion study. PMID:25799362

  16. Dust production in supernovae and AGB stars

    NASA Astrophysics Data System (ADS)

    Matsuura, Mikako

    2015-08-01

    In the last decade, the role of supernovae on dust has changed; it has been long proposed that supernovae are dust destroyers, but now recent observations show that core-collapse supernovae can become dust factories. Theoretical models of dust evolution in galaxies have predicted that core-collapse supernovae can be an important source of dust in galaxies, if these supernovae can form a significant mass of dust (0.1-1 solar masses). The Herschel Space Observatory and ALMA detected dust in the ejecta of Supernova 1987A. They revealed an estimated 0.5 solar masses of dust. Herschel also found nearly 0.1 solar masses of dust in historical supernovae remnants, namely Cassiopeia A and the Crab Nebula. If dust grains can survive future interaction with the supernova winds and ambient interstellar medium, core-collapse supernovae can be an important source of dust in the interstellar media of galaxies. We further discuss the total dust mass injected by AGB stars and SNe into the interstellar medium of the Magellanic Clouds.

  17. Dust Studies in DIII-D Tokamak

    SciTech Connect

    Rudakov, D L; West, W P; Groth, M; Yu, J H; Boedo, J A; Bray, B D; Brooks, N H; Fenstermacher, M E; Hollmann, E M; Hyatt, A W; Krasheninnikov, S I; Lasnier, C J; Moyer, R A; Pigarov, A Y; Smirnov, R; Solomon, W M; Wong, C C

    2008-04-15

    Studies of submicron dust using Mie scattering from Nd:YAG lasers and video data of micron to sub-millimeter sized dust on DIII-D tokamak have provided the first data of dust sources and transport during tokamak discharges. During normal operation on DIII-D dust observation rates are low, a few events per discharge or less. The net carbon content of the dust corresponds to a carbon atom density a few orders of magnitude below the core impurity density. Statistical analysis of Mie data collected over months of operation reveal correlation of increased dust rate with increased heating power and impulsive wall loading due to edge localized modes (ELMs) and disruptions. Generation of significant amounts of dust by disruptions is confirmed by the camera data. However, dust production by disruptions alone is insufficient to account for estimated in-vessel dust inventory in DIII-D. After an extended entry vent, thousands of dust particles are observed by cameras in the first 2-3 plasma discharges. Individual particles moving at velocities up to {approx}300 m/s, breakup of larger particles into pieces, and collisions of particles with walls are observed. After {approx}70 discharges, dust levels are reduced to a few events per discharge. In order to calibrate diagnostics and benchmark modeling, milligram amounts of micron-sized carbon dust have been injected into DIII-D discharges, leading to the core carbon density increase by a factor of 2-3. Following injection, dust trajectories in the divertor are mostly in the toroidal direction, consistent with the ion drag force. Dust from the injection is observed in the outboard midplane by a fast framing camera. The observed trajectories and velocities of the dust particles are in qualitative agreement with modeling by the 3D DustT code.

  18. Dust Studies in DIII-D Tokamak

    SciTech Connect

    Rudakov, D. L.; Yu, J. H.; Boedo, J. A.; Hollmann, E. M.; Krasheninnikov, S. I.; Moyer, R. A.; Pigarov, A. Yu.; Smirnov, R.; West, W. P.; Bray, B. D.; Brooks, N. H.; Hyatt, A. W.; Wong, C. P. C.; Groth, M.; Fenstermacher, M. E.; Lasnier, C. J.; Solomon, W. M.

    2008-09-07

    Studies of submicron dust using Mie scattering from Nd:YAG lasers and video data of micron to sub-millimeter sized dust on DIII-D tokamak have provided the first data of dust sources and transport during tokamak discharges. During normal operation on DIII-D dust observation rates are low, a few events per discharge or less. The net carbon content of the dust corresponds to a carbon atom density a few orders of magnitude below the core impurity density. Statistical analysis of Mie data collected over months of operation reveal correlation of increased dust rate with increased heating power and impulsive wall loading due to edge localized modes (ELMs) and disruptions. Generation of significant amounts of dust by disruptions is confirmed by the camera data. However, dust production by disruptions alone is insufficient to account for estimated in-vessel dust inventory in DIII-D. After an extended entry vent, thousands of dust particles are observed by cameras in the first 2-3 plasma discharges. Individual particles moving at velocities up to {approx}300 m/s, breakup of larger particles into pieces, and collisions of particles with walls are observed. After {approx}70 discharges, dust levels are reduced to a few events per discharge. In order to calibrate diagnostics and benchmark modeling, milligram amounts of micron-sized carbon dust have been injected into DIII-D discharges, leading to the core carbon density increase by a factor of 2-3. Following injection, dust trajectories in the divertor are mostly in the toroidal direction, consistent with the ion drag force. Dust from the injection is observed in the outboard midplane by a fast framing camera. The observed trajectories and velocities of the dust particles are in qualitative agreement with modeling by the 3D DustT code.

  19. Effect of nonadiabaticity of dust charge variation on dust acoustic waves: generation of dust acoustic shock waves.

    PubMed

    Gupta, M R; Sarkar, S; Ghosh, S; Debnath, M; Khan, M

    2001-04-01

    The effect of nonadiabaticity of dust charge variation arising due to small nonzero values of tau(ch)/tau(d) has been studied where tau(ch) and tau(d) are the dust charging and dust hydrodynamical time scales on the nonlinear propagation of dust acoustic waves. Analytical investigation shows that the propagation of a small amplitude wave is governed by a Korteweg-de Vries (KdV) Burger equation. Notwithstanding the soliton decay, the "soliton mass" is conserved, but the dissipative term leads to the development of a noise tail. Nonadiabaticity generated dissipative effect causes the generation of a dust acoustic shock wave having oscillatory behavior on the downstream side. Numerical investigations reveal that the propagation of a large amplitude dust acoustic shock wave with dust density enhancement may occur only for Mach numbers lying between a minimum and a maximum value whose dependence on the dusty plasma parameters is presented. PMID:11308955

  20. Does the removal of mite-infested brood facilitate grooming?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The relationship between the removal of mite-infested brood and mite drop was compared using Russian (RHB, n = 9) and Italian (IHB, n = 9) honey bee colonies. A cloake board was used to isolate test brood frame on the top hive body and the metal sheet served as a varroa trap. Inoculum mites were col...

  1. Identification of crinosterol from astigamatid mites.

    PubMed

    Murakami, Kenjiro; Watanabe, Bunta; Nishida, Ritsuo; Mori, Naoki; Kuwahara, Yasumasa

    2007-05-01

    A 24-alkylsterol, crinosterol [(24S)-24-methylcholesta-5,22(E)-dien-3beta-ol] has been isolated from sea-dwelling animals, protists and plants. Here, we identified crinosterol from nine species of mites (Acari). The compound was identified by using (1)H-NMR analysis and GCMS spectral data along with the HPLC retention time by comparing with those of the synthesized compound. As far as we know, this is the first report on the identification of crinosterol from arthropods. Furthermore, after Rhizoglyphus robini were fed on artificial diets with d(3)-methionine, d(2)-crinosterol was detected from the mite's extracts. The incorporation of two deuterium atoms into the sterol indicated that a d(3)-methyl group was introduced into the C24 of the side chain to form crinosterol. Although the details of the biosynthesis of crinosterol remain unknown, the discovery of crinosterol in the mites implies the existence of interesting sterol metabolisms in the animals.

  2. Density and growth rates of spider mites in relation to phenological stages of soybean cultivars in Brazil.

    PubMed

    Arnemann, Jonas André; Fiorin, Rubens Alex; Perini, Clérison Régis; Storck, Lindolfo; Curioletti, Luis Eduardo; Nachman, Gösta; Guedes, Jerson Vanderlei Carús

    2015-11-01

    The population fluctuations of spider mites on different soybean cultivars were studied in two experiments performed in the municipalities of São Sepé (experiment 1) and Santa Maria (experiment 2) in the state of Rio Grande do Sul, Brazil. The number of cultivars was 20 in São Sepé and 25 in Santa Maria, and at each location leaves were sampled from 15 plants per cultivar every week throughout the entire plant developmental cycle, amounting to 11 and 10 samplings in experiment 1 and 2, respectively. The statistical analysis revealed that mite densities varied significantly with cultivar and time. Besides, the interaction between soybean cultivars and sampling times was significant at both locations. This indicates that the populations did not vary in the same way among cultivars over time, which is attributed to differences among the cultivars with respect to their phenology and response to spider mites. Equations for describing the mite population dynamics were estimated for each cultivar, mostly by fitting cubic equations to the weekly growth rates (per capita changes) in mite densities. We also found that the highest growth rates for mites on soybean cultivars in both locations occurred after the beginning of flowering, when the plants shifted from the vegetative to reproductive stages, about 3 weeks before reaching the peak densities.

  3. Density and growth rates of spider mites in relation to phenological stages of soybean cultivars in Brazil.

    PubMed

    Arnemann, Jonas André; Fiorin, Rubens Alex; Perini, Clérison Régis; Storck, Lindolfo; Curioletti, Luis Eduardo; Nachman, Gösta; Guedes, Jerson Vanderlei Carús

    2015-11-01

    The population fluctuations of spider mites on different soybean cultivars were studied in two experiments performed in the municipalities of São Sepé (experiment 1) and Santa Maria (experiment 2) in the state of Rio Grande do Sul, Brazil. The number of cultivars was 20 in São Sepé and 25 in Santa Maria, and at each location leaves were sampled from 15 plants per cultivar every week throughout the entire plant developmental cycle, amounting to 11 and 10 samplings in experiment 1 and 2, respectively. The statistical analysis revealed that mite densities varied significantly with cultivar and time. Besides, the interaction between soybean cultivars and sampling times was significant at both locations. This indicates that the populations did not vary in the same way among cultivars over time, which is attributed to differences among the cultivars with respect to their phenology and response to spider mites. Equations for describing the mite population dynamics were estimated for each cultivar, mostly by fitting cubic equations to the weekly growth rates (per capita changes) in mite densities. We also found that the highest growth rates for mites on soybean cultivars in both locations occurred after the beginning of flowering, when the plants shifted from the vegetative to reproductive stages, about 3 weeks before reaching the peak densities. PMID:26272161

  4. "Inert" formulation ingredients with activity: toxicity of trisiloxane surfactant solutions to twospotted spider mites (Acari: Tetranychidae).

    PubMed

    Cowles, R S; Cowles, E A; McDermott, A M; Ramoutar, D

    2000-04-01

    Organosilicone molecules are important surfactant ingredients used in formulating pesticides. These methylated silicones are considered inert ingredients, but their superior surfactant properties allow them to wet, and either suffocate or disrupt important physiological processes in mites and insects. Aqueous solutions of the tri-siloxane surfactants Silwet L-77, Silwet 408, and Silwet 806 were bioassayed against adult female two-spotted spider mites, Tetranychus urticae Koch, with leaf dip methods to compare their toxicity with organosilicone molecules containing bulkier hydrophobic components. All three tri-siloxanes in aqueous solutions were equivalently toxic (LC50 = 5.5-8.9 ppm), whereas Silwet L-7607 solutions were less toxic (LC50 = 4,800 ppm) and Silwet L-7200 was nontoxic to mites. In another experiment, the toxicity of Silwet L-77 was affected by the wettability of leaf surfaces. The LC50 shifted from 22 to 84 ppm when mites were tested on bean and strawberry leaf disks, respectively. Droplet spreading on paraffin and surface tension were both related to the toxicity of surfactant solutions. Surface tensions of solutions below 23 mN/m caused > 90% mite mortality in leaf dip bioassays. A field test of Conserve SC and its formulation blank, with and without Dyne-Amic adjuvant (a vegetable oil-organosilicone surfactant mixture) revealed that Dyne-Amic had the greatest miticidal contribution, reducing mite populations by 70%, followed by formulation inactive ingredients. Spinosad, the listed active ingredient in Conserve, only contributed miticidal activity when synergized by Dyne-Amic. Researchers should include appropriate surfactant or formulation blank controls when testing insecticides or miticides, especially when using high spray volumes.

  5. Dust Storm in Southern California

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Along historic Route 66, just southeast of the little town of Amboy, California, lies a dried-up lake. Dry lakebeds are good sources of two things: salt and dust. In this image, the now-parched Bristol Lake offers up both. On April 12, 2007, dust storms menaced the area around Amboy. To the northwest, near Newberry Springs, California, dust hampered visibility and led to a multi-car collision on Interstate 40, killing two people and injuring several others. The same day, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of a dust storm in the dry remains of Bristol Lake. Many small dust clouds boil up from the ground surface, casting their shadows to the northwest. A bright white cloud floating over the dust also throws its shadow onto the ground below. East of the dust storm are salt works that stand out from the surrounding landscape thanks to their straight lines and sharp angles. Dark ground surfaces alternate with mined white salt in a network of stripes. When lakes evaporate, chemicals that had been dissolved in the water stay behind, making dry lake beds an ideal place to find heavy concentrations of minerals, including salt. Besides the salt works, something else appears in stark contrast to this arid place. Lush green fields of irrigated crops appear in the east. Besides their color, their orderly arrangement reveals their human-made origin.

  6. Acaroid mite, intestinal and urinary acariasis

    PubMed Central

    Li, Chao-Pin; Cui, Yu-Bao; Wang, Jian; Yang, Qing-Gui; Tian, Ye

    2003-01-01

    AIM: To investigate epidemiology and pathogenic mite species of intestinal and urinary acariasis in individuals with different occupations. METHODS: A total of 1994 individuals were tested in this study. History collection, skin prick test and pathogen identification were conducted. The mites were isolated from stool and urine samples by saturated saline flotation methods and sieving following centrifugation, respectively. RESULTS: Among the 1994 individuals examined, responses to the skin prick test of “+++”, “++”, “+”, “±” and “-” were observed at frequencies of 3.96% (79), 3.21% (64), 2.31% (46), 1.25% (25) and 89.27% (1780), respectively. A total number of 161 (8.07%) individuals were shown to carry mites, with 92 (4.61%) positive only for stool samples, 37 (1.86%) positive only for urine samples and 32 (1.60%) for both. The positive rate of mites in stool samples was 6.22% (124/1994), being 6.84% (78/1140) for males and 5.39% (46/854) for females. No gender difference was observed in this study (χ2 = 1.77, P > 0.05). The mites from stool samples included Acarus siro, TyroPhagus putrescentiae, Dermatophagoides farinae, D. pteronyssinus, Glycyphagus domesticus, G.ornatus, Carpoglyphus lactis and Tarsonemus granaries. The positive rate of mites in urine samples was 3.46% (69/1994). The positive rates for male and female subjects were found to be 3.95% (45/1140) and 2.81% (24/854) respectively, with no gender difference observed (χ2 = 1.89, P > 0.05). Mites species in urine samples included Acarus siro, Tyrophagus putrescentiae, T. longior, Aleuroglyphus ovatus, Caloglyphus berlesei, C. mycophagus, Suidasia nesbitti, Lardoglyphus konoi, Glycyphagus domesticus, Carpoglyphus lactis, Lepidoglyphus destructor, Dermatophagoides farinae, D. pteronyssinus, Euroglyphus magnei, Caloglyphus hughesi, Tarsonemus granarus and T. hominis. The species of mites in stool and urine samples were consistent with those separated from working environment. A

  7. [Foci of the rat mite Ornithonyssus bacoti (Mesostigmata, Macronyssidae) and rat-mite dermatitis in Moscow].

    PubMed

    Lopatina, Iu V; Sokolova, T V; Niiazova, M V

    1992-01-01

    High density of the rat population in Moscow in 1990-1991 resulted in the appearance of Ornithonyssus bacoti foci and of cases of the rat-mite dermatitis in humans. A total of 36 foci of the disease were examined and eradicated. A method for the detection of such foci has been developed. Two types of foci are distinguished, communal and industrial, and their specific features as regards the rodent and mite populations and clinical features of dermatitis in humans are described. A system of measures for liquidation of foci of rat mites is suggested, including rat and mite eradication and treatment of the patients. Specific features of these measures for various types of foci and in case of a focus reappearance are enumerated. PMID:1299760

  8. Influence of wear, pile height, and cleaning method on removal of mite allergen from carpet.

    PubMed

    Causer, Simon M; Lewis, Roger D; Batek, Joseph M; Ong, Kee-Hean

    2004-04-01

    Carpet is a major sink for house dust mite allergen. Vacuum extraction methods have been shown to reduce concentrations of such allergen in dust, but the influence of carpet construction and cleaning parameters on the efficiency of extraction is poorly understood. The objective of this study was to determine the effect of construction, degree of wear, and cleaning method on ease of removal of the primary allergen (Der f I) derived from the North American house-dust mite, Dermatophagoides Farinae. Carpets of different pile heights were seeded with house dust, some were then subjected to artificial wear, and all were then either dry vacuumed or wet extracted. The Der f I content of carpet cores was measured at each stage. As a result, the degree of wear and pile height were shown to be the two most important factors determining ease of Der f I removal from carpet. For worn carpet, dry vacuuming of short pile constructions was shown to be significantly more effective (p 61%) for unworn carpet than for worn carpet (<30%). Only minor differences between types of cleaning method (wet vs. dry) were found. This study suggests that carpets differ greatly in their propensity to retain allergens, and that a consideration of carpet age, construction, and cleaning regime is important when advising the merits of different floor covering types, and on allergen avoidance techniques.

  9. Effects of habitat age and plant species on predatory mites (Acari, Mesostigmata) in grassy arable fallows in Eastern Austria

    PubMed Central

    Wissuwa, Janet; Salamon, Jörg-Alfred; Frank, Thomas

    2012-01-01

    Density, diversity and assemblage structure of Mesostigmata (cohorts Gamasina and Uropodina) were investigated in nine grassy arable fallows according to a factorial design with age class (2–3, 6–8, 12–15 years) and plant species (legume: Medicago sativa, herb: Taraxacum officinale, grass: Bromus sterilis) as factors. The response of Mesostigmata to habitat age and plant species was explored because this group belongs to the dominant acarine predators playing a crucial role in soil food webs and being important as biological control agents. To our knowledge, this combination of factors has never been studied before for Mesostigmata. A further rarely applied aspect of the present study is the micro-scale approach investigating the Mesostigmata assemblage of the soil associated with single plants. Four plots were randomly chosen at each fallow in May 2008. At each plot plant roots and the adjacent soil of five randomly selected plant individuals per plant species were dug out with steel cylinders for heat extraction of soil fauna and measurement of environmental parameters. In total, 83 mite taxa were identified, with 50 taxa being new to Austria. GLM analysis revealed a significant effect of plant species on mite density, with significantly more mites in B. sterilis than in T. officinale samples, and M. sativa samples being intermediate. This was in contrast to the assumption that the mite density is highest in M. sativa samples due to the propagation of plant quality effects to higher trophic levels. These results were probably caused by a higher amount of fine roots in grass samples leading to high densities of Collembola, which are preferred prey of predatory mites. Mite density did not significantly differ between the three age classes. A canonical analysis of principal coordinates (CAP) showed that the mite assemblage exhibited a weak yet significant separation between plant species, and a highly significant separation between age classes. Accordingly

  10. Chewing lice (Insecta, Phthiraptera) and feather mites (Acari, Astigmata) associated with birds of the Cerrado in Central Brazil.

    PubMed

    Enout, Alexandre Magno Junqueira; Lobato, Débora Nogueira Campos; Diniz, Francisco Carvalho; Antonini, Yasmine

    2012-10-01

    The association of chewing lice and feather mites with wild birds of riparian forest was investigated in the Cerrado biome, Tocantins State, Brazil. The birds were captured with mist nets between July 2008 and March 2009. Ectoparasites were collected by the dust-ruffling technique. Infestation rates were determined by the sampling prevalence, abundance, and mean intensity of ectoparasites. A total of 1,479 chewing lice were collected that were distributed in 3 families and 18 genera, of which 15 taxa were identified to the species level. Sixteen genera of feather mites were found, and 10 species were identified. A high prevalence rate of chewing lice and feather mites was found in non-Passeriformes (66.7 and 50.0%) and Passeriformes (57.8 and 75.6%) birds. New host-parasite associations were registered for two species of chewing lice and for four species of feather mites, thus expanding the geographical distribution in Brazil of six chewing lice species. This is the first study of the ectoparasites of wild birds to be conducted in this region of Brazil.

  11. Laboratory screening of potential predators of the poultry red mite (Dermanyssus gallinae) and assessment of Hypoaspis miles performance under varying biotic and abiotic conditions.

    PubMed

    Ali, W; George, D R; Shiel, R S; Sparagano, O A E; Guy, J H

    2012-06-01

    The poultry red mite, Dermanyssus gallinae (De Geer), is the most important ectoparasitic pest of layer hens worldwide and difficult to control through 'conventional' synthetic acaricides. The present study aimed to identify a suitable predator of D. gallinae that could potentially form the basis of biological control in commercial poultry systems. From four selected predatory mite species (Hypoaspis miles (Berlese), Hypoaspis aculeifer (Canestrini), Amblyseius degenerans (Berlese) and Phytoseiulus persimilis (Athias-Henriot)), Hypoaspis mites demonstrated the greatest potential as predators of D. gallinae. Experiments were also conducted to assess the effect of environmental (temperature and dust), physical (presence of harbourages) and biological (presence of alternative prey) factors on the predatory efficacy of H. miles. Predation of D. gallinae per se was observed under all conditions tested, though was found to be temperature-dependent and reduced by the presence of alternative prey. PMID:22301375

  12. Laboratory screening of potential predators of the poultry red mite (Dermanyssus gallinae) and assessment of Hypoaspis miles performance under varying biotic and abiotic conditions.

    PubMed

    Ali, W; George, D R; Shiel, R S; Sparagano, O A E; Guy, J H

    2012-06-01

    The poultry red mite, Dermanyssus gallinae (De Geer), is the most important ectoparasitic pest of layer hens worldwide and difficult to control through 'conventional' synthetic acaricides. The present study aimed to identify a suitable predator of D. gallinae that could potentially form the basis of biological control in commercial poultry systems. From four selected predatory mite species (Hypoaspis miles (Berlese), Hypoaspis aculeifer (Canestrini), Amblyseius degenerans (Berlese) and Phytoseiulus persimilis (Athias-Henriot)), Hypoaspis mites demonstrated the greatest potential as predators of D. gallinae. Experiments were also conducted to assess the effect of environmental (temperature and dust), physical (presence of harbourages) and biological (presence of alternative prey) factors on the predatory efficacy of H. miles. Predation of D. gallinae per se was observed under all conditions tested, though was found to be temperature-dependent and reduced by the presence of alternative prey.

  13. Tropical rat mites (Ornithonyssus bacoti) - serious ectoparasites.

    PubMed

    Beck, Wieland; Fölster-Holst, Regina

    2009-08-01

    In Germany there is limited information available about the distribution of the tropical rat mite (Ornithonyssus bacoti) in rodents. A few case reports show that this hematophagous mite species may also cause dermatitis in man. Having close body contact to small rodents is an important question for patients with pruritic dermatoses. The definitive diagnosis of this ectoparasitosis requires the detection of the parasite, which is more likely to be found in the environment of its host (in the cages, in the litter or in corners or cracks of the living area) than on the hosts' skin itself. A case of infestation with tropical rat mites in a family is reported here. Three mice that had been removed from the home two months before were the reservoir. The mites were detected in a room where the cage with the mice had been placed months ago. Treatment requires the eradication of the parasites on its hosts (by a veterinarian) and in the environment (by an exterminator) with adequate acaricides such as permethrin. PMID:19508683

  14. Hold your breath beetle-Mites!

    PubMed

    Gudowska, Agnieszka; Drobniak, Szymon M; Schramm, Bartosz W; Labecka, Anna Maria; Kozlowski, Jan; Bauchinger, Ulf

    2016-01-01

    Respiratory gas exchange in insects occurs via a branching tracheal system. The entrances to the air-filled tracheae are the spiracles, which are gate-like structures in the exoskeleton. The open or closed state of spiracles defines the three possible gas exchange patterns of insects. In resting insects, spiracles may open and close over time in a repeatable fashion that results in a discontinuous gas exchange (DGE) pattern characterized by periods of zero organism-to-environment gas exchange. Several adaptive hypotheses have been proposed to explain why insects engage in DGE, but none have attracted overwhelming support. We provide support for a previously untested hypothesis that posits that DGE minimizes the risk of infestation of the tracheal system by mites and other agents. Here, we analyze the respiratory patterns of 15 species of ground beetle (Carabidae), of which more than 40% of individuals harbored external mites. Compared with mite-free individuals, infested one's engaged significantly more often in DGE. Mite-free individuals predominantly employed a cyclic or continuous gas exchange pattern, which did not include complete spiracle closure. Complete spiracle closure may prevent parasites from invading, clogging, or transferring pathogens to the tracheal system or from foraging on tissue not protected by thick chitinous layers.

  15. Standard methods for tracheal mite research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter, for the COLOSS Beebook from the Bee Research Center in Switzerland, summarizes all the current information about the tracheal mite (Acarapis woodi) infesting honey bees (Apis mellifera). The chapter covers the effects on bees, its life history, and its range, as well as the identifica...

  16. Population survey of phytoseiid mites and spider mites on peach leaves and wild plants in Japanese peach orchard.

    PubMed

    Wari, David; Yamashita, Jun; Kataoka, Yoko; Kohara, Yoko; Hinomoto, Norihide; Kishimoto, Hidenari; Toyoshima, Shingo; Sonoda, Shoji

    2014-07-01

    A population survey of phytoseiid mites and spider mites was conducted on peach leaves and wild plants in Japanese peach orchards having different pesticide practices. The phytoseiid mite species composition on peach leaves and wild plants, as estimated using quantitative sequencing, changed during the survey period. Moreover, it varied among study sites. The phytoseiid mite species compositions were similar between peach leaves and some wild plants, such as Veronica persica, Paederia foetida, Persicaria longiseta, and Oxalis corniculata with larger quantities of phytoseiid mites, especially after mid-summer. A PCR-based method to detect the ribosomal ITS sequences of Tetranychus kanzawai and Panonychus mori from phytoseiid mites was developed. Results showed that Euseius sojaensis (specialized pollen feeder/generalist predator) uses both spider mites as prey in the field.

  17. Distribution of Dust from Kuiper Belt Objects

    NASA Technical Reports Server (NTRS)

    Gorkavyi, Nick N.; Ozernoy, Leonid; Taidakova, Tanya; Mather, John C.; Fisher, Richard (Technical Monitor)

    2000-01-01

    Using an efficient computational approach, we have reconstructed the structure of the dust cloud in the Solar system between 0.5 and 100 AU produced by the Kuiper belt objects. Our simulations offer a 3-D physical model of the 'kuiperoidal' dust cloud based on the distribution of 280 dust particle trajectories produced by 100 known Kuiper belt objects; the resulting 3-D grid consists of 1.9 x 10' cells containing 1.2 x 10" particle positions. The following processes that influence the dust particle dynamics are taken into account: 1) gravitational scattering on the eight planets (neglecting Pluto); 2) planetary resonances; 3) radiation pressure; and 4) the Poynting-Robertson (P-R) and solar wind drags. We find the dust distribution highly non-uniform: there is a minimum in the kuiperoidal dust between Mars and Jupiter, after which both the column and number densities of kuiperoidal dust sharply increase with heliocentric distance between 5 and 10 AU, and then form a plateau between 10 and 50 AU. Between 25 and 45 AU, there is an appreciable concentration of kuiperoidal dust in the form of a broad belt of mostly resonant particles associated with Neptune. In fact, each giant planet possesses its own circumsolar dust belt consisting of both resonant and gravitationally scattered particles. As with the cometary belts simulated in our related papers, we reveal a rich and sophisticated resonant structure of the dust belts containing families of resonant peaks and gaps. An important result is that both the column and number dust density are more or less flat between 10 and 50 AU, which might explain the surprising data obtained by Pioneers 10 & 11 and Voyager that the dust number density remains approximately distance-independent in this region. The simulated kuiperoidal dust, in addition to asteroidal and cometary dust, might represent a third possible source of the zodiacal light in the Solar system.

  18. Canyon Dust

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA03682 Canyon Dust

    These dust slides are located on the wall of Thithonium Chasma.

    Image information: VIS instrument. Latitude -4.1N, Longitude 275.7E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  19. Dust Slides

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Context image for PIA03677 Linear Clouds

    Dust slides are common in the dust covered region called Lycus Sulci. A large fracture is also visible in this image.

    Image information: VIS instrument. Latitude 28.1N, Longitude 226.3E. 18 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  20. Dust agglomeration

    NASA Technical Reports Server (NTRS)

    2000-01-01

    John Marshall, an investigator at Ames Research Center and a principal investigator in the microgravity fluid physics program, is studying the adhesion and cohesion of particles in order to shed light on how granular systems behave. These systems include everything from giant dust clouds that form planets to tiny compressed pellets, such as the ones you swallow as tablets. This knowledge should help us control the grains, dust, and powders that we encounter or use on a daily basis. Marshall investigated electrostatic charge in microgravity on the first and second U.S. Microgravity Laboratory shuttle missions to see how grains aggregate, or stick together. With gravity's effects eliminated on orbit, Marshall found that the grains of sand that behaved ever so freely on Earth now behaved like flour. They would just glom together in clumps and were quite difficult to disperse. That led to an understanding of the prevalence of the electrostatic forces. The granules wanted to aggregate as little chains, like little hairs, and stack end to end. Some of the chains had 20 or 30 grains. This phenomenon indicated that another force, what Marshall believes to be an electrostatic dipole, was at work.(The diagram on the right emphasizes the aggregating particles in the photo on the left, taken during the USML-2 mission in 1995.)

  1. Wild tomato leaf extracts for spider mite and cowpea aphid control.

    PubMed

    Antonious, George F; Kamminga, Katherine; Snyder, John C

    2014-01-01

    Glandular trichomes on the leaves of wild tomato, L. hirsutum f. hirsutum Mull, also known as Solanum habrochaites (Solanaceae), synthesize and accumulate high levels of methyl ketones (MKs). L. hirsutum accession LA 407, having high concentration of MKs, was grown from seeds under greenhouse conditions. Four MKs (2-undecanone, 2-dodecanone, 2-tridecanone, and 2-pentadecanone) were screened for their toxicity to spider mites, Tetranychus urticae Koch and cowpea aphids, Aphis craccivora Koch. The objectives of this investigation were to: (1) develop a bioassay for testing MKs on spider mite and cowpea aphid mortality and (2) compare the efficacies of wild tomato leaf crude extracts and pure standard materials of MKs against spider mite and cowpea aphid mortality. Our results revealed that spider mites are most sensitive to 2-tridecanone (LC50 = 0.08 μmole cm(-2) of treated leaf surface) and least sensitive to 2-undecanone (LC50 = 1.5 μmole cm(-2) of treated leaf surface) 4 h after treatment. Similarly, 2-tridecanone caused greatest mortality (LC50 = 0.2 μmole cm(-2) of treated leaf surface), whereas 2-undecanone caused the lowest morality (LC50 = 0.48 μmole cm(-2) of treated surface) of cowpea aphid. We concluded that all MKs tested in this investigation are toxic to spider mites and aphids. 2-Tridecanone is more effective in killing mites and aphids compared to other MKs. Toxicity of crude extracts, prepared from the leaves of L. hirsutum accession LA 407, to spider mites and cowpea aphids revealed greater mortality compared to a combined mixture of MKs standard material (used at the same concentration as found on LA 407 leaves). This indicates that in addition to MKs, other unidentified compounds in LA 407 leaf extract also have pesticidal properties. Accordingly, leaf extracts of LA 407 could be explored in crop protection, and they might open a new area of MK formulations and discovery of biorational alternatives for pest control in agricultural fields.

  2. Wild tomato leaf extracts for spider mite and cowpea aphid control.

    PubMed

    Antonious, George F; Kamminga, Katherine; Snyder, John C

    2014-01-01

    Glandular trichomes on the leaves of wild tomato, L. hirsutum f. hirsutum Mull, also known as Solanum habrochaites (Solanaceae), synthesize and accumulate high levels of methyl ketones (MKs). L. hirsutum accession LA 407, having high concentration of MKs, was grown from seeds under greenhouse conditions. Four MKs (2-undecanone, 2-dodecanone, 2-tridecanone, and 2-pentadecanone) were screened for their toxicity to spider mites, Tetranychus urticae Koch and cowpea aphids, Aphis craccivora Koch. The objectives of this investigation were to: (1) develop a bioassay for testing MKs on spider mite and cowpea aphid mortality and (2) compare the efficacies of wild tomato leaf crude extracts and pure standard materials of MKs against spider mite and cowpea aphid mortality. Our results revealed that spider mites are most sensitive to 2-tridecanone (LC50 = 0.08 μmole cm(-2) of treated leaf surface) and least sensitive to 2-undecanone (LC50 = 1.5 μmole cm(-2) of treated leaf surface) 4 h after treatment. Similarly, 2-tridecanone caused greatest mortality (LC50 = 0.2 μmole cm(-2) of treated leaf surface), whereas 2-undecanone caused the lowest morality (LC50 = 0.48 μmole cm(-2) of treated surface) of cowpea aphid. We concluded that all MKs tested in this investigation are toxic to spider mites and aphids. 2-Tridecanone is more effective in killing mites and aphids compared to other MKs. Toxicity of crude extracts, prepared from the leaves of L. hirsutum accession LA 407, to spider mites and cowpea aphids revealed greater mortality compared to a combined mixture of MKs standard material (used at the same concentration as found on LA 407 leaves). This indicates that in addition to MKs, other unidentified compounds in LA 407 leaf extract also have pesticidal properties. Accordingly, leaf extracts of LA 407 could be explored in crop protection, and they might open a new area of MK formulations and discovery of biorational alternatives for pest control in agricultural fields. PMID

  3. Reuyl Crater Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 13 May 2002) The Science The rugged, arcuate rim of the 90 km crater Reuyl dominates this THEMIS image. Reuyl crater is at the southern edge of a region known to be blanketed in thick dust based on its high albedo (brightness) and low thermal inertia values. This thick mantle of dust creates the appearance of snow covered mountains in the image. Like snow accumulation on Earth, Martian dust can become so thick that it eventually slides down the face of steep slopes, creating runaway avalanches of dust. In the center of this image about 1/3 of the way down is evidence of this phenomenon. A few dozen dark streaks can be seen on the bright, sunlit slopes of the crater rim. The narrow streaks extend downslope following the local topography in a manner very similar to snow avalanches on Earth. But unlike their terrestrial counterparts, no accumulation occurs at the bottom. The dust particles are so small that they are easily launched into the thin atmosphere where they remain suspended and ultimately blow away. The apparent darkness of the avalanche scars is due to the presence of relatively dark underlying material that becomes exposed following the passage of the avalanche. Over time, new dust deposition occurs, brightening the scars until they fade into the background. Although dark slope streaks had been observed in Viking mission images, a clear understanding of this dynamic phenomenon wasn't possible until the much higher resolution images from the Mars Global Surveyor MOC camera revealed the details. MOC images also showed that new avalanches have occurred during the time MGS has been in orbit. THEMIS images will allow additional mapping of their distribution and frequency, contributing new insights about Martian dust avalanches. The Story The stiff peaks in this image might remind you of the Alps here on Earth, but they really outline the choppy edge of a large Martian crater over 50 miles wide (seen in the context image at right). While these aren

  4. Immunochemical approach to indoor aeroallergen quantitation with a new volumetric air sampler: studies with mite, roach, cat, mouse, and guinea pig antigens

    SciTech Connect

    Swanson, M.C.; Agarwal, M.K.; Reed, C.E.

    1985-11-01

    We describe a new high-volume air sampler for determining antigen concentrations in homes and illustrate its use for quantitating airborne house dust mite, cat, cockroach, mouse, and guinea pig antigens. The concentration of house dust-mite antigen was similar from houses in Rochester, Minn. and tenement apartments in Harlem, N. Y., but cockroach and mouse urinary proteins were present only in Harlem. The amount of cat or guinea pig antigen varied as expected with the number of pets in the home. In calm air the airborne concentration of mite and cat antigen was similar throughout the house but increased greatly in a bedroom when bedding was changed. In calm air most of the cat and mite antigens were associated with respirable particles less than 5 microns mean aerodynamic mass diameter, but in air sampled after the bedding was changed, more cat antigen was found in particles greater than 5 microns. The apparatus and technique described can provide objective data concerning the magnitude and the relative distribution and duration of suspended particles of defined sizes, which contain allergen activity.

  5. Interstellar Dust: Contributed Papers

    NASA Technical Reports Server (NTRS)

    Tielens, Alexander G. G. M. (Editor); Allamandola, Louis J. (Editor)

    1989-01-01

    A coherent picture of the dust composition and its physical characteristics in the various phases of the interstellar medium was the central theme. Topics addressed included: dust in diffuse interstellar medium; overidentified infrared emission features; dust in dense clouds; dust in galaxies; optical properties of dust grains; interstellar dust models; interstellar dust and the solar system; dust formation and destruction; UV, visible, and IR observations of interstellar extinction; and quantum-statistical calculations of IR emission from highly vibrationally excited polycyclic aromatic hydrocarbon (PAH) molecules.

  6. Uranium mill ore dust characterization

    SciTech Connect

    Knuth, R.H.; George, A.C.

    1980-11-01

    Cascade impactor and general air ore dust measurements were taken in a uranium processing mill in order to characterize the airborne activity, the degree of equilibrium, the particle size distribution and the respirable fraction for the /sup 238/U chain nuclides. The sampling locations were selected to limit the possibility of cross contamination by airborne dusts originating in different process areas of the mill. The reliability of the modified impactor and measurement techniques was ascertained by duplicate sampling. The results reveal no significant deviation from secular equilibrium in both airborne and bulk ore samples for the /sup 234/U and /sup 230/Th nuclides. In total airborne dust measurements, the /sup 226/Ra and /sup 210/Pb nuclides were found to be depleted by 20 and 25%, respectively. Bulk ore samples showed depletions of 10% for the /sup 226/Ra and /sup 210/Pb nuclides. Impactor samples show disequilibrium of /sup 226/Ra as high as +-50% for different size fractions. In these samples the /sup 226/Ra ratio was generally found to increase as particle size decreased. Activity median aerodynamic diameters of the airborne dusts ranged from 5 to 30 ..mu..m with a median diameter of 11 ..mu..m. The maximum respirable fraction for the ore dusts, based on the proposed International Commission on Radiological Protection's (ICRP) definition of pulmonary deposition, was < 15% of the total airborne concentration. Ore dust parameters calculated for impactor duplicate samples were found to be in excellent agreement.

  7. long duration dust storm sequences on Mars

    NASA Astrophysics Data System (ADS)

    Wang, H.

    2012-12-01

    The Mars Global Surveyor (MGS) Mars Observer Camera (MOC) and Mars Reconnaissance Orbiter (MRO) Mars Color Imager (MARCI) Mars daily global maps have revealed new characteristics for long duration dust storm sequences. These dust storm sequences have long histories of more than a week, travel long distances out of their origination region, and influence large areas in different regions of the planet. During the Ls = 180 - 360 season, except for global dust storms which involve multiple remote dust lifting centers and generally expand explosively from the southern hemisphere northward, other long-lived dust storm sequences usually travel southward through the Acidalia-Chryse, Utopia-Isidis or Arcadia-Amazonis channels with subsequent dust lifting along the way. Sometimes, they penetrate remarkably deep to the southern high latitudes, producing fantastic display of dust band. During the rest of the year, long duration dust storm sequences usually originate from the Argyre/Solis, Hellas/Noachis, or Cimmeria/Sirenum area and travel northward toward the southern low latitudes. Each route exhibits its own peculiar characteristics. We will present our results about these long duration dust storm sequences summarized from the complete archive of MGS MOC daily global maps and two years of MRO MARCI daily global maps. The systematic daily nearly global coverage of these maps makes it feasible to reconstruct the history of long duration dust storm sequences with detail.

  8. Concentration and determinants of molds and allergens in indoor air and house dust of French dwellings.

    PubMed

    Dallongeville, Arnaud; Le Cann, Pierre; Zmirou-Navier, Denis; Chevrier, Cécile; Costet, Nathalie; Annesi-Maesano, Isabella; Blanchard, Olivier

    2015-12-01

    Molds and allergens are common indoor biocontaminants. The aims of this study were to assess the concentrations of common molds in indoor air and floor dust and the concentrations of house dust mite, cat and dog allergens in mattress dust in French dwellings, and to assess predictors of these concentrations. A sample of 150 houses in Brittany (western France) was investigated. Airborne Cladosporium and Penicillium were detected in more than 90% of the dwellings, Aspergillus in 46% and Alternaria in only 6% of the housings. Regarding floor dust samples, Cladosporium and Penicillium were detected in 92 and 80% of the housings respectively, Aspergillus in 49% and Alternaria in 14%. House dust mite allergens Der p1 and Der f1 were detected in 90% and 77% of the mattress dust samples respectively and Can f1 and Fel d1 in 37% and 89% of the homes. Airborne and dustborne mold concentrations, although not statistically correlated (except for Aspergillus) shared most of their predictors. Multivariate linear models for mold levels, explaining up to 62% of the variability, showed an influence of the season, of the age of the dwelling, of aeration habits, presence of pets, smoking, signals of dampness, temperature and relative humidity. Allergens in the dust of the mattress were strongly related to the presence of pets and cleaning practices of bedsheets, these factors accounting for 60% of the variability. This study highlights ubiquitous contamination by molds and underlines complex interaction between outdoor and indoor sources and factors. PMID:26094801

  9. Dust devil vortices seen by the Mars Pathfinder camera

    USGS Publications Warehouse

    Metzger, S.M.; Carr, J.R.; Johnson, J. R.; Parker, T.J.; Lemmon, M.T.

    1999-01-01

    Discovery of dust devil vortices in Mars Pathfinder (MPF) images reveals a dust entrainment mechanism at work on Mars. Scattering of visible light by dust in the Martian atmosphere creates a pronounced haze, preventing conventional image processing from displaying dust plumes. Spectral differencing techniques have enhanced five localized dust plumes from the general haze in images acquired near midday, which we determine to be dust devils. Processing of 440 nm images highlights dust devils as distinct occultation features against the horizon. The dust devils are interpreted to be 14-79 m wide, 46-350 m tall, travel at 0.5-4.6 m/s, with dust loading of 7E-5 kg m-3, relative to the general haze of 9E-8 kg m-3, and total particulate transport of 2.2 - 700 kg. The vortices match predictions from terrestrial analog studies. Copyright 1999 by the American Geophysical Union.

  10. In-situ dust measurements by a lunar lander

    NASA Astrophysics Data System (ADS)

    Srama, Ralf; Sternovsky, Zoltan; Horanyi, Mihaly; Gruen, Eberhard; Krueger, Harald; Laufer, Rene; Roeser, Hans-Peter; Postberg, Frank; Kempf, Sascha; Moragas-Klostermeyer, Georg; Mocker, Anna; Fiege, Katherina; Li, Yanwei

    2012-07-01

    Charged dust grains on the lunar surface impact our future exploration of the moon. Serious problems for exploration activities were revealed by the Apollo missions. Dust shows strong adhesion to equipment and clothes and makes breathing difficult within a spacecraft. The micron- and submicron sized grains are embedded in the lunar plasma environment and their physical properties determine their dynamics. The solar wind, UV light and shadows lead to temporal effects in plasma densities and dust grain charging states. The dust populations relevant for the processes on the surface are: interplanetary and interstellar dust, levitated dust and, especially, dust ejecta generated by primary impacts on the surface. A dust instrument on the surface shall distinguish the three populations and characterize their charging state, size, speed and directionality distribution. Dust measurements shall be performed in conjunction with surface plasma and surface electric field characterizations.

  11. Dust Measurements in Tokamaks

    SciTech Connect

    Rudakov, D; Yu, J; Boedo, J; Hollmann, E; Krasheninnikov, S; Moyer, R; Muller, S; Yu, A; Rosenberg, M; Smirnov, R; West, W; Boivin, R; Bray, B; Brooks, N; Hyatt, A; Wong, C; Fenstermacher, M; Groth, M; Lasnier, C; McLean, A; Stangeby, P; Ratynskaia, S; Roquemore, A; Skinner, C; Solomon, W M

    2008-04-23

    Dust production and accumulation impose safety and operational concerns for ITER. Diagnostics to monitor dust levels in the plasma as well as in-vessel dust inventory are currently being tested in a few tokamaks. Dust accumulation in ITER is likely to occur in hidden areas, e.g. between tiles and under divertor baffles. A novel electrostatic dust detector for monitoring dust in these regions has been developed and tested at PPPL. In DIII-D tokamak dust diagnostics include Mie scattering from Nd:YAG lasers, visible imaging, and spectroscopy. Laser scattering resolves size of particles between 0.16-1.6 {micro}m in diameter; the total dust content in the edge plasmas and trends in the dust production rates within this size range have been established. Individual dust particles are observed by visible imaging using fast-framing cameras, detecting dust particles of a few microns in diameter and larger. Dust velocities and trajectories can be determined in 2D with a single camera or 3D using multiple cameras, but determination of particle size is problematic. In order to calibrate diagnostics and benchmark dust dynamics modeling, pre-characterized carbon dust has been injected into the lower divertor of DIII-D. Injected dust is seen by cameras, and spectroscopic diagnostics observe an increase of carbon atomic, C2 dimer, and thermal continuum emissions from the injected dust. The latter observation can be used in the design of novel dust survey diagnostics.

  12. Salivary proteins of spider mites suppress defenses in Nicotiana benthamiana and promote mite reproduction.

    PubMed

    Villarroel, Carlos A; Jonckheere, Wim; Alba, Juan M; Glas, Joris J; Dermauw, Wannes; Haring, Michel A; Van Leeuwen, Thomas; Schuurink, Robert C; Kant, Merijn R

    2016-04-01

    Spider mites (Tetranychidae sp.) are widely occurring arthropod pests on cultivated plants. Feeding by the two-spotted spider mite T. urticae, a generalist herbivore, induces a defense response in plants that mainly depends on the phytohormones jasmonic acid and salicylic acid (SA). On tomato (Solanum lycopersicum), however, certain genotypes of T. urticae and the specialist species T. evansi were found to suppress these defenses. This phenomenon occurs downstream of phytohormone accumulation via an unknown mechanism. We investigated if spider mites possess effector-like proteins in their saliva that can account for this defense suppression. First we performed an in silico prediction of the T. urticae and the T. evansi secretomes, and subsequently generated a short list of candidate effectors based on additional selection criteria such as life stage-specific expression and salivary gland expression via whole mount in situ hybridization. We picked the top five most promising protein families and then expressed representatives in Nicotiana benthamiana using Agrobacterium tumefaciens transient expression assays to assess their effect on plant defenses. Four proteins from two families suppressed defenses downstream of the phytohormone SA. Furthermore, T. urticae performance on N. benthamiana improved in response to transient expression of three of these proteins and this improvement was similar to that of mites feeding on the tomato SA accumulation mutant nahG. Our results suggest that both generalist and specialist plant-eating mite species are sensitive to SA defenses but secrete proteins via their saliva to reduce the negative effects of these defenses. PMID:26946468

  13. Salivary proteins of spider mites suppress defenses in Nicotiana benthamiana and promote mite reproduction.

    PubMed

    Villarroel, Carlos A; Jonckheere, Wim; Alba, Juan M; Glas, Joris J; Dermauw, Wannes; Haring, Michel A; Van Leeuwen, Thomas; Schuurink, Robert C; Kant, Merijn R

    2016-04-01

    Spider mites (Tetranychidae sp.) are widely occurring arthropod pests on cultivated plants. Feeding by the two-spotted spider mite T. urticae, a generalist herbivore, induces a defense response in plants that mainly depends on the phytohormones jasmonic acid and salicylic acid (SA). On tomato (Solanum lycopersicum), however, certain genotypes of T. urticae and the specialist species T. evansi were found to suppress these defenses. This phenomenon occurs downstream of phytohormone accumulation via an unknown mechanism. We investigated if spider mites possess effector-like proteins in their saliva that can account for this defense suppression. First we performed an in silico prediction of the T. urticae and the T. evansi secretomes, and subsequently generated a short list of candidate effectors based on additional selection criteria such as life stage-specific expression and salivary gland expression via whole mount in situ hybridization. We picked the top five most promising protein families and then expressed representatives in Nicotiana benthamiana using Agrobacterium tumefaciens transient expression assays to assess their effect on plant defenses. Four proteins from two families suppressed defenses downstream of the phytohormone SA. Furthermore, T. urticae performance on N. benthamiana improved in response to transient expression of three of these proteins and this improvement was similar to that of mites feeding on the tomato SA accumulation mutant nahG. Our results suggest that both generalist and specialist plant-eating mite species are sensitive to SA defenses but secrete proteins via their saliva to reduce the negative effects of these defenses.

  14. Metal dusting

    SciTech Connect

    Edited by K. Natesan

    2004-01-01

    This workshop was held soon after the September 11th incident under a climate of sorrow and uncertainty among the people of the world, in particular the Workshop participants and their host organizations. With considerable help from the partiicpants, the Workshop was conducted as planed and we had excellent participation in spite of the circumstances. A good fraction of the attendees in the Workshop were from abroad and from several industries, indicating the importance and relevance of the subject for the chemical process industry. Degradation of structural metallic alloys by metal dusting has been an issue for over 40 years in the chemical, petrochemical, syngas, and iron ore reduction plants. However, the fundamental scientific reasons for the degradation of complex alloys in high carbon activity environments are not clear. one of the major parameters of importance is the variation in gas chemistry in both the laboratory experiments and in the plant-service environments. the industry has questioned the applicability of the laboratory test data, obtained in low steam environments, in assessment and life prediction for the materials in plant service where the environments contain 25-35% steam. Several other variables such as system pressure, gas flow velocity, incubation time, alloy chemistry, surface finish, and weldments, were also identified in the literature as to having an effect on the initiatino and propagation of metal dusting attack. It is the purpose of this Workshop to establish a forum in which the researchers from scientific and industrial laboratories, alloy manufacturers, end users, and research and development sponsors can exchange information, discuss different points of view, prioritize the issues, and to elaborate on the trends in industry for the future. We believe that we accomplished these goals successfully and sincerely thank the participants for their contributions.

  15. Remote sensing of spider mite damage in California peach orchards

    NASA Astrophysics Data System (ADS)

    Luedeling, Eike; Hale, Adam; Zhang, Minghua; Bentley, Walter J.; Dharmasri, L. Cecil

    2009-08-01

    Remote sensing techniques can decrease pest monitoring costs in orchards. To evaluate the feasibility of detecting spider mite damage in orchards, we measured visible and near infrared reflectance of 1153 leaves and 392 canopies in 11 peach orchards in California. Pairs of significant wavelengths, identified by Partial Least Squares regression, were combined into normalized difference indices. These and 9 previously published indices were evaluated for correlation with mite damage. Eight spectral regions for leaves and two regions for canopies (at blue and red wavelengths) were significantly correlated with mite damage. These findings were tested by calculating normalized difference indices from the Red and Blue bands of six multispectral aerial images. Index values were linearly correlated with mite damage ( R2 = 0.47), allowing identification of mite hotspots in orchards. However, better standardization of aerial imagery and accounting for perturbing environmental factors will be necessary for making this technique applicable for early mite detection.

  16. Seasonal phoresy as an overwintering strategy of a phytophagous mite

    PubMed Central

    Liu, Sai; Li, Jianling; Guo, Kun; Qiao, Haili; Xu, Rong; Chen, Jianmin; Xu, Changqing; Chen, Jun

    2016-01-01

    Migration by attachment to insects is common among mites that live in temporary habitats. However, because plants provide relatively stable habitats, phytophagous mites are generally not dependent on other animals for dispersal, so whether these mites can consistently be phoretic on insects through a particular life stage remains unclear and controversial. Here, we describe an obligate phoresy of a wholly phytophagous mite, Aceria pallida, in which the mites accompanied the psyllid Bactericera gobica to its winter hibernation sites, thus successfully escaping unfavourable winter conditions, and returned to reach the buds of their host plant early the following spring. This finding provides evidence of a new overwintering strategy that has contributed to the evolutionary success of these tiny phytophagous mites. PMID:27150196

  17. Seasonal phoresy as an overwintering strategy of a phytophagous mite.

    PubMed

    Liu, Sai; Li, Jianling; Guo, Kun; Qiao, Haili; Xu, Rong; Chen, Jianmin; Xu, Changqing; Chen, Jun

    2016-01-01

    Migration by attachment to insects is common among mites that live in temporary habitats. However, because plants provide relatively stable habitats, phytophagous mites are generally not dependent on other animals for dispersal, so whether these mites can consistently be phoretic on insects through a particular life stage remains unclear and controversial. Here, we describe an obligate phoresy of a wholly phytophagous mite, Aceria pallida, in which the mites accompanied the psyllid Bactericera gobica to its winter hibernation sites, thus successfully escaping unfavourable winter conditions, and returned to reach the buds of their host plant early the following spring. This finding provides evidence of a new overwintering strategy that has contributed to the evolutionary success of these tiny phytophagous mites. PMID:27150196

  18. Mite, cat, and cockroach exposure, allergen sensitisation, and asthma in children: a case-control study of three schools

    PubMed Central

    Sporik, R.; Squillace, S.; Ingram, J. M.; Rakes, G.; Honsinger, R.; Platts-Mills, T.

    1999-01-01

    BACKGROUND—The amount of allergen necessary to sensitise genetically "at risk" children is unclear. The relation between allergen exposure and asthma is also uncertain.
METHODS—To ensure a wide range of allergen exposures the data from case-control studies of asthma in children aged 12-14 years attending three schools in Los Alamos, New Mexico and Central Virginia were combined. Skin prick tests to indoor and outdoor allergens and bronchial hyperreactivity to histamine were assessed in children with and without symptoms of asthma. The concentration of mite, cat, and cockroach allergens in dust from the children's homes was used as a marker of exposure.
RESULTS—Three hundred and thirty two children (157 with asthmatic symptoms and 175 controls) were investigated. One hundred and eighty three were classified as atopic on the basis of allergen skin prick tests and 68 as asthmatic (symptoms plus bronchial responsiveness). The prevalence and degree of sensitisation to mite and cockroach, but not cat, was strongly associated in atopic children with increasing domestic concentrations of these allergens. Asthma was strongly associated with sensitisation to indoor allergens (p<10-6) and weakly to outdoor allergens (p = 0.026). There was an association between current asthma and the concentration of mite allergen amongst atopic children (p = 0.008) but not amongst those who were specifically mite sensitised (p = 0.16).
CONCLUSIONS—The domestic reservoir concentration of mite and cockroach, but not cat, allergen was closely related to the prevalence of sensitisation in atopic children. However, the prevalence of current asthma had a limited relationship to these allergen measurements, suggesting that other factors play a major part in determining which allergic individuals develop asthma.

 PMID:10413718

  19. Tyrophagus putrescentiae: an allergenically important mite.

    PubMed

    Green, W F; Woolcock, A J

    1978-03-01

    The incidence of positive skin tests to the mite Tyrophagus putrescentiae was measured and compared with skin reactions to Dermatophagoides pteronyssinus and other allergens in Australian and New Guinean populations, and mite counts were determined in Sydney and New Guinea houses. Positive reactions to T. putrescentiae were as frequent as those for D. pteronyssinus in asthmatics in Sydney and were the commonest positive reactions in the normal New Guinea population. T. putrescentiae-specific serum IgE levels were determined and some IgG cross-reactions of D. pteronyssinus and T. putrescentiae antigens were demonstrated. It is suggested that T. putrescentiae is an important source of allergen and should be considered whenever D. pteronyssinus is thought to be a problem. A convenient method for culturing and isolating T. putrescentiae is described. PMID:647897

  20. The Jean Gutierrez spider mite collection.

    PubMed

    Migeon, Alain

    2015-01-01

    The family Tetranychidae (spider mites) currently comprises 1,275 species and represents one of the most important agricultural pest families among the Acari with approximately one hundred pest species, ten of which considered major pests. The dataset presented in this document includes all the identified spider mites composing the Jean Gutierrez Collection hosted at the CBGP (Montferrier-sur-Lez, France), gathered from 1963 to 1999 during his career at the Institut de Recherche pour le Développement (IRD). It consists of 5,262 specimens corresponding to 1,564 occurrences (combination species/host plant/date/location) of 175 species. Most specimens were collected in Madagascar and other islands of the Western Indian Ocean, New Caledonia and other islands of the South Pacific and Papuasia. The dataset constitutes today the most important one available on Tetranychidae worldwide.

  1. Mange mite infestation in small ruminants in Ethiopia: Systematic review and meta-analysis.

    PubMed

    Asmare, Kassahun; Abebe, Rahmeto; Sheferaw, Desie; Krontveit, Randi I; Barbara, Wieland

    2016-03-15

    Mange mites are economically important ectoparasites of sheep and goats responsible for rejection or downgrading of skins in tanneries or leather industries in Ethiopia. The objective of this systematic review was to compute the pooled prevalence estimate and identify factors influencing mange mite prevalence in sheep and goats at national level based on the available research evidence. Articles on mange mite infestation of small ruminants in Ethiopia were searched in PubMed, Web of Science, Google scholar and African journals on-line. The review was based on 18 cross-sectional studies carried out between 2003 and 2015 in four administrative states of Ethiopia. Accordingly, the pooled prevalence estimate in a random effects meta-analysis was estimated to be 4.4% (95% CI 3.0, 6.3) although there were evidence of a substantial amount of between-study variance (I(2)=98.4%). In subgroup and multivariable meta-regression analyses, animal species, agro-ecology and administrative state were found to have significant effect on the prevalence estimate (P<0.05) and explained 32.87% of the explainable proportion of the heterogeneity noted between studies The prevalence was found to be higher in goats in lowland agro-ecology. Region wise the highest estimate was calculated for Amhara (6.4%) followed by Oromia (4.7%), Tigray (3.6%) and Southern Nations, Nationalities and People Region (SNNPR) (3.1%). Significant difference was noted between Amhara and SNNPR. The study further revealed that mites of the genus Sarcoptes, Demodex and Psoroptes are the most prevalent mites infesting small ruminants in Ethiopia. Valid studies were lacking from five regional states. As some of these regions are known for their large small ruminant population, further studies are warranted to produce better picture of the infestation at a national level. Meanwhile, the need for monitoring the ongoing control intervention is suggested. PMID:26872931

  2. Mange mite infestation in small ruminants in Ethiopia: Systematic review and meta-analysis.

    PubMed

    Asmare, Kassahun; Abebe, Rahmeto; Sheferaw, Desie; Krontveit, Randi I; Barbara, Wieland

    2016-03-15

    Mange mites are economically important ectoparasites of sheep and goats responsible for rejection or downgrading of skins in tanneries or leather industries in Ethiopia. The objective of this systematic review was to compute the pooled prevalence estimate and identify factors influencing mange mite prevalence in sheep and goats at national level based on the available research evidence. Articles on mange mite infestation of small ruminants in Ethiopia were searched in PubMed, Web of Science, Google scholar and African journals on-line. The review was based on 18 cross-sectional studies carried out between 2003 and 2015 in four administrative states of Ethiopia. Accordingly, the pooled prevalence estimate in a random effects meta-analysis was estimated to be 4.4% (95% CI 3.0, 6.3) although there were evidence of a substantial amount of between-study variance (I(2)=98.4%). In subgroup and multivariable meta-regression analyses, animal species, agro-ecology and administrative state were found to have significant effect on the prevalence estimate (P<0.05) and explained 32.87% of the explainable proportion of the heterogeneity noted between studies The prevalence was found to be higher in goats in lowland agro-ecology. Region wise the highest estimate was calculated for Amhara (6.4%) followed by Oromia (4.7%), Tigray (3.6%) and Southern Nations, Nationalities and People Region (SNNPR) (3.1%). Significant difference was noted between Amhara and SNNPR. The study further revealed that mites of the genus Sarcoptes, Demodex and Psoroptes are the most prevalent mites infesting small ruminants in Ethiopia. Valid studies were lacking from five regional states. As some of these regions are known for their large small ruminant population, further studies are warranted to produce better picture of the infestation at a national level. Meanwhile, the need for monitoring the ongoing control intervention is suggested.

  3. Comparative analysis of two edaphic zoocoenoses (Oribatid mites and Carabid beetles) in five habitats of the 'Pietraporciana' and 'Lucciolabella' Nature Reserves (Orcia Valley, central Italy)

    NASA Astrophysics Data System (ADS)

    Migliorini, Massimo; Petrioli, Andrea; Bernini, Fabio

    2002-12-01

    Oribatid mite and Carabid beetle communities were investigated at five sites in the 'Pietraporciana' and 'Lucciolabella' Nature Reserves (central Italy). In this part of southern Tuscany many attempts have been made to encourage the regeneration of native habitats and to preserve existing ones. Human-induced changes in the original forest landscape have had a direct impact on mite and carabid populations. Significant differences in species diversity and abundance among different sites were revealed throughout the sampling period. Species richness, abundance and diversity of oribatid mites decrease from woodland sites to open habitats where evenness was high. There is an inverse trend between the number of species and richness of carabid beetles and those of oribatid mites. Canonical correspondence analysis (CCA) of oribatid and carabid beetle compositions discriminated the sites, demonstrating how even small areas with different vegetation, composition, structure, environment and microclimate were characterised by distinct edaphic populations.

  4. Ectoparasitic insects and mites on Yunnan red-backed voles (Eothenomys miletus) from a localized area in southwest China.

    PubMed

    Guo, Xian-Guo; Speakman, John R; Dong, Wen-Ge; Men, Xing-Yuan; Qian, Ti-Jun; Wu, Dian; Qin, Feng; Song, Wen-Yu

    2013-10-01

    Ectoparasitic insects and mites on Yunnan red-backed voles (Eothenomys miletus) in Dali prefecture, Yunnan Province, southwest China, were studied between 2003 and 2004. In total, 34,389 individuals of 86 species of ectoparasitic insects (seven species of fleas and five species of sucking lice) and mites (23 species of gamasid mites and 51 species of chigger mites) were collected from 916 individual hosts. The diversity of ectoparasites on this single rodent species in such a small area was much higher than in previous reports, which concerned more host species and greater geographical areas. The majority of the ectoparasites were chigger mites, which accounted for 59.3% of the parasite species and 87.4% of the individual parasites. Most voles harbored parasites with an overall prevalence (P) of 82.5% and mean abundance (MA) of 37.5 parasites per host. The dispersion coefficient (C) and patchiness index (m*/m) were used to study the spatial patterns of the seven dominant parasite species, and all seven had aggregated distributions. The species abundance distribution of the ectoparasites on the vole was fitted by Preston's lognormal distribution (R (2) = 0.82), and the total expected parasite species was estimated from this plot as 167 species. Yunnan red-backed voles harbor many ectoparasites as revealed by examination of a large host population. Future field investigations should sample large numbers of host individuals to assess ectoparasite populations.

  5. Relative contribution of biotic and abiotic factors to the population density of the cassava green mite, Mononychellus tanajoa (Acari: Tetranychidae).

    PubMed

    Rêgo, Adriano S; Teodoro, Adenir V; Maciel, Anilde G S; Sarmento, Renato A

    2013-08-01

    The cassava green mite, Mononychellus tanajoa, is a key pest of cassava, Manihot esculenta Crantz (Euphorbiaceae), and it may be kept in check by naturally occurring predatory mites of the family Phytoseiidae. In addition to predatory mites, abiotic factors may also contribute to regulate pest mite populations in the field. Here, we evaluated the population densities of both M. tanajoa and the generalist predatory mite Euseius ho DeLeon (Acari: Phytoseiidae) over the cultivation cycle (11 months) of cassava in four study sites located around the city of Miranda do Norte, Maranhão, Brazil. The abiotic variables rainfall, temperature and relative humidity were also recorded throughout the cultivation cycle of cassava. We determined the relative importance of biotic (density of E. ho) and abiotic (rainfall, temperature and relative humidity) factors to the density of M. tanajoa. The density of M. tanajoa increased whereas the density of E. ho remained constant throughout time. A hierarchical partitioning analysis revealed that most of the variance for the density of M. tanajoa was explained by rainfall and relative humidity followed by E. ho density and temperature. We conclude that abiotic factors, especially rainfall, were the main mechanisms driving M. tanajoa densities.

  6. Planetary science: Cometary dust under the microscope

    NASA Astrophysics Data System (ADS)

    Kolokolova, Ludmilla

    2016-09-01

    The Rosetta spacecraft made history by successfully orbiting a comet. Data from the craft now reveal the structure of the comet's dust particles, shedding light on the processes that form planetary systems. See Letter p.73

  7. Dust feed mechanism

    DOEpatents

    Milliman, Edward M.

    1984-01-01

    The invention is a dust feed device for delivery of a uniform supply of dust for long periods of time to an aerosolizing means for production of a dust suspension. The device utilizes at least two tandem containers having spiral brushes within the containers which transport the dust from a supply to the aerosolizer means.

  8. Acaroid mites (Acari: Astigmata) in Chinese traditional medicines.

    PubMed

    Cui, Y-B; Li, C-P; Wang, J; Yang, Q-G; Tian, Y

    2003-12-01

    Almost 2000 samples of the dried plants and animals used in Chinese traditional medicine were collected from a storehouse in Huainan city, Anhui province, China, where they had been kept for at least 6 months. When examined, every sample was found to contain acaroid mites. The mites included representatives of 44 species belonging to 22 genera and seven families. It seems that samples of Chinese traditional medicine frequently become severely infested with mites while in storage. More importance should be attached to protecting the medicines against mite infestation and to protecting against acariasis those who ingest or simply handle the medicines.

  9. Mites associated with stored grain commodities in Benin, West Africa.

    PubMed

    Zannou, Ignace D; Adebo, Habib O; Zannou, Elisabeth; Hell, Kerstin

    2013-12-01

    After insects, mites are the major arthropod pests that inhabit stored agricultural products worldwide. To determine the acarofauna that infests cowpea, maize, paddy rice and sorghum in Benin (West Africa), surveys were conducted in some principal markets (Dantokpa, Glazoue and Parakou) of this country. A total of 555 samples of grains and debris were collected in May and September 2011. More than 56 species belonging to 24 mite families were recorded in the four products. These mite species included predators, parasites, fungivorous, phytophagous and other groups whose feeding habits are not well known. The family Cheyletidae was the most prevalent and the most diverse predatory mite family encountered, in which Cheyletus malaccensis Oudemans was the most abundant species. Several families of mite pests and mites responsible for allergies (Acaridae, Glycyphagidae, Pyroglyphidae, Pyemotidae and Saproglyphidae) were also detected. The three most dominant and frequent species were C. malaccensis, Suidasia nesbitti (Hughes) and Suidasia sp. Statistical analysis showed that densities of these three mite species were higher in Parakou than in Glazoue and Dantokpa, on one hand, and higher in debris than in grains, on the other hand. The densities of S. nesbitti and Suidasia sp. decreased significantly during the dry season, whereas C. malaccensis remained stable throughout the two samplings. Of all grains, sorghum was the least infested with mites. This study shows that in Benin mites are present in stored agricultural products to which they cause serious damage, and may cause various allergies to people.

  10. Time-Based Measurement of Personal Mite Allergen Bioaerosol Exposure over 24 Hour Periods.

    PubMed

    Tovey, Euan R; Liu-Brennan, Damien; Garden, Frances L; Oliver, Brian G; Perzanowski, Matthew S; Marks, Guy B

    2016-01-01

    Allergic diseases such as asthma and rhinitis are common in many countries. Globally the most common allergen associated with symptoms is produced by house dust mites. Although the bed has often been cited as the main site of exposure to mite allergens, surprisingly this has not yet been directly established by measurement due to a lack of suitable methods. Here we report on the development of novel methods to determine the pattern of personal exposure to mite allergen bioaerosols over 24-hour periods and applied this in a small field study using 10 normal adults. Air was sampled using a miniature time-based air-sampler of in-house design located close to the breathing zone of the participants, co-located with a miniature time-lapse camera. Airborne particles, drawn into the sampler at 2L/min via a narrow slot, were impacted onto the peripheral surface of a disk mounted on the hour-hand of either a 12 or 24 hour clock motor. The impaction surface was either an electret cloth, or an adhesive film; both novel for these purposes. Following a review of the time-lapse images, disks were post-hoc cut into subsamples corresponding to eight predetermined categories of indoor or outdoor location, extracted and analysed for mite allergen Der p 1 by an amplified ELISA. Allergen was detected in 57.2% of the total of 353 subsamples collected during 20 days of sampling. Exposure patterns varied over time. Higher concentrations of airborne mite allergen were typically measured in samples collected from domestic locations in the day and evening. Indoor domestic Der p 1 exposures accounted for 59.5% of total exposure, whereas total in-bed-asleep exposure, which varied 80 fold between individuals, accounted overall for 9.85% of total exposure, suggesting beds are not often the main site of exposure. This study establishes the feasibility of novel methods for determining the time-geography of personal exposure to many bioaerosols and identifies new areas for future technical

  11. Time-Based Measurement of Personal Mite Allergen Bioaerosol Exposure over 24 Hour Periods

    PubMed Central

    Tovey, Euan R.; Liu-Brennan, Damien; Garden, Frances L.; Oliver, Brian G.; Perzanowski, Matthew S.; Marks, Guy B.

    2016-01-01

    Allergic diseases such as asthma and rhinitis are common in many countries. Globally the most common allergen associated with symptoms is produced by house dust mites. Although the bed has often been cited as the main site of exposure to mite allergens, surprisingly this has not yet been directly established by measurement due to a lack of suitable methods. Here we report on the development of novel methods to determine the pattern of personal exposure to mite allergen bioaerosols over 24-hour periods and applied this in a small field study using 10 normal adults. Air was sampled using a miniature time-based air-sampler of in-house design located close to the breathing zone of the participants, co-located with a miniature time-lapse camera. Airborne particles, drawn into the sampler at 2L/min via a narrow slot, were impacted onto the peripheral surface of a disk mounted on the hour-hand of either a 12 or 24 hour clock motor. The impaction surface was either an electret cloth, or an adhesive film; both novel for these purposes. Following a review of the time-lapse images, disks were post-hoc cut into subsamples corresponding to eight predetermined categories of indoor or outdoor location, extracted and analysed for mite allergen Der p 1 by an amplified ELISA. Allergen was detected in 57.2% of the total of 353 subsamples collected during 20 days of sampling. Exposure patterns varied over time. Higher concentrations of airborne mite allergen were typically measured in samples collected from domestic locations in the day and evening. Indoor domestic Der p 1 exposures accounted for 59.5% of total exposure, whereas total in-bed-asleep exposure, which varied 80 fold between individuals, accounted overall for 9.85% of total exposure, suggesting beds are not often the main site of exposure. This study establishes the feasibility of novel methods for determining the time-geography of personal exposure to many bioaerosols and identifies new areas for future technical

  12. Exposure to grain dust in Great Britain.

    PubMed

    Spankie, Sally; Cherrie, John W

    2012-01-01

    Airborne grain dust is a complex mixture of fragments of organic material from grain, plus mineral matter from soil, and possible insect, fungal, or bacterial contamination or their toxic products, such as endotoxin. In the 1990s, grain workers in Britain were frequently exposed to inhalable dust >10 mg.m(-3) (8 h), with particularly high exposures being found at terminals where grain was imported or exported and in drying operations (personal exposure typically approximately 20 mg.m(-3)). Since then, the industry has made substantial progress in improving the control of airborne dust through better-designed processes, increased automation, and an improved focus on product quality. We have used information from the published scientific literature and a small survey of industry representatives to estimate current exposure levels. These data suggest that current long-term exposure to inhalable dust for most workers is on average less than approximately 3 mg.m(-3), with perhaps 15-20% of individual personal exposures being >10 mg.m(-3). There are no published data from Britain on short-term exposure during cleaning and other tasks. We have estimated average levels for a range of tasks and judge that the highest levels, for example during some cleaning activities and certain process tasks such as loading and packing, are probably approximately10 mg.m(-3). Endotoxin levels were judged likely to be <10⁴ EU m(-3) throughout the industry provided inhalable dust levels are <10 mg.m(-3). There are no published exposure data on mycotoxin, respirable crystalline silica, and mite contamination but these are not considered to present widespread problems in the British industry. Further research should be carried out to confirm these findings.

  13. Early Embryogenesis-Specific Expression of the Rice Transposon Ping Enhances Amplification of the MITE mPing

    PubMed Central

    Teramoto, Shota; Tsukiyama, Takuji; Okumoto, Yutaka; Tanisaka, Takatoshi

    2014-01-01

    Miniature inverted-repeat transposable elements (MITEs) are numerically predominant transposable elements in the rice genome, and their activities have influenced the evolution of genes. Very little is known about how MITEs can rapidly amplify to thousands in the genome. The rice MITE mPing is quiescent in most cultivars under natural growth conditions, although it is activated by various stresses, such as tissue culture, gamma-ray irradiation, and high hydrostatic pressure. Exceptionally in the temperate japonica rice strain EG4 (cultivar Gimbozu), mPing has reached over 1000 copies in the genome, and is amplifying owing to its active transposition even under natural growth conditions. Being the only active MITE, mPing in EG4 is an appropriate material to study how MITEs amplify in the genome. Here, we provide important findings regarding the transposition and amplification of mPing in EG4. Transposon display of mPing using various tissues of a single EG4 plant revealed that most de novo mPing insertions arise in embryogenesis during the period from 3 to 5 days after pollination (DAP), and a large majority of these insertions are transmissible to the next generation. Locus-specific PCR showed that mPing excisions and insertions arose at the same time (3 to 5 DAP). Moreover, expression analysis and in situ hybridization analysis revealed that Ping, an autonomous partner for mPing, was markedly up-regulated in the 3 DAP embryo of EG4, whereas such up-regulation of Ping was not observed in the mPing-inactive cultivar Nipponbare. These results demonstrate that the early embryogenesis-specific expression of Ping is responsible for the successful amplification of mPing in EG4. This study helps not only to elucidate the whole mechanism of mPing amplification but also to further understand the contribution of MITEs to genome evolution. PMID:24921928

  14. Evaluation of predatory mite (Acari: Phytoseiidae) releases to suppress spruce spider mites, Oligonychus ununguis (Acari: Tetranychidae), on juniper.

    PubMed

    Shrewsbury, Paula M; Hardin, Mark R

    2003-12-01

    A laboratory trial evaluated four phytoseiid species for their potential as biological control agents of spruce spider mite, Oligonychus ununguis (Jacobi) (Acari: Tetranychidae). An augmentative biological control approach, using the predatory mites Neoseiulus fallacis Garman and Galendromus occidentalis Nesbitt (Acari: Phytoseiidae), was evaluated for reducing pest mite densities and injury, and economic costs on Juniperus chinensis 'Sargentii' A. Henry (Cupressaceae) in an outdoor nursery. Sequential releases of predator species, individually and in combination, were tested and compared with two commonly used miticides, a low-toxicity miticide, horticultural oil, and a conventional miticide, hexythiazox. Timing of treatments was based on grower-determined need, and predator release rates were based on guidelines in literature received from producers of beneficial organisms. Predator releases were more expensive and provided less effective suppression of spruce spider mites, resulting in greater spider mite injury to plants, compared with conventional pesticides. However, spider mite damage to plants did not differ in an economically meaningful way between treatments. Unsatisfactory levels of control seem related to under estimations of actual spider mite abundance based on grower perceptions and the beat sampling technique used to estimate predator release rates. These data suggest that when initial populations of spruce spider mite are high, it is unlikely that sequential releases of predator species, individually or in combination, will suppress spider mite populations. In this trial, augmentative biological control control was 2.5-7 times more expensive than chemical controls.

  15. Scent of a mite: origin and chemical characterization of the lemon-like flavor of mite-ripened cheeses.

    PubMed

    Brückner, Adrian; Heethoff, Michael

    2016-07-01

    Cheese infested with cheese mites is usually treated as unpalatable. Nevertheless, some traditional cheese manufactories in Germany and France intentionally use mites for fermentation of special varieties (i.e. Milbenkäse and Mimolette). While their production includes different mite species, both are characterized by a "lemon-like" flavor. However, the chemical nature and origin of this flavor-component is unknown. The cheese mites possess a pair of opisthosomal glands producing blends of hydrocarbons, terpenes and aromatics. Here, we describe the chemical profiles of the astigmatid mite species Tyrolichus casei (Milbenkäse) and Acarus siro (Mimolette). Although the chemical profiles differ in several aspects, both mite species produce neral (a volatile flavor component of lemon oil), which was absent from the headspace of both cheeses without mites. We conclude that the lemon-like flavor of mite cheese is not a consequence of fermentation of the cheese itself but a component from secretions of the cheese mites. PMID:27059866

  16. Dust Avalanches

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    Crater wall dust avalanches in southern Arabia Terra.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

    Image information: VIS instrument. Latitude 10.3, Longitude 24.5 East (335.5 West). 19 meter/pixel resolution.

  17. Theory of dust voids in plasmas.

    PubMed

    Goree, J; Morfill, G E; Tsytovich, V N; Vladimirov, S V

    1999-06-01

    Dusty plasmas in a gas discharge often feature a stable void, i.e., a dust-free region inside the dust cloud. This occurs under conditions relevant to both plasma processing discharges and plasma crystal experiments. The void results from a balance of the electrostatic and ion drag forces on a dust particle. The ion drag force is driven by a flow of ions outward from an ionization source and toward the surrounding dust cloud, which has a negative space charge. In equilibrium the force balance for dust particles requires that the boundary with the dust cloud be sharp, provided that the particles are cold and monodispersive. Numerical solutions of the one-dimensional nonlinear fluid equations are carried out including dust charging and dust-neutral collisions, but not ion-neutral collisions. The regions of parameter space that allow stable void equilibria are identified. There is a minimum ionization rate that can sustain a void. Spatial profiles of plasma parameters in the void are reported. In the absence of ion-neutral collisions, the ion flow enters the dust cloud's edge at Mach number M=1. Phase diagrams for expanding or contracting voids reveal a stationary point corresponding to a single stable equilibrium void size, provided the ionization rate is constant. Large voids contract and small voids expand until they attain this stationary void size. On the other hand, if the ionization rate is not constant, the void size can oscillate. Results are compared to recent laboratory and microgravity experiments.

  18. Dust particle dynamics in atmospheric dust devils

    NASA Astrophysics Data System (ADS)

    Izvekova, Yulia; Popel, Sergey

    2016-04-01

    Dust particle dynamics is modeled in the Dust Devils (DDs). DD is a strong, well-formed, and relatively long-lived whirlwind, ranging from small (half a meter wide and a few meters tall) to large (more than 100 meters wide and more than 1000 meters tall) in Earth's atmosphere. We develop methods for the description of dust particle charging in DDs, discuss the ionization processes in DDs, and model charged dust particle motion. Our conclusions are consistent with the fact that DD can lift a big amount of dust from the surface of a planet into its atmosphere. On the basis of the model we perform calculations and show that DDs are important mechanism for dust uplift in the atmospheres of Earth and Mars. Influence of DD electric field on dynamics of dust particles is investigated. It is shown that influence of the electric field on dust particles trajectories is significant near the ground. At some altitude (more then a quarter of the height of DD) influence of the electric field on dust particles trajectories is negligible. For the calculation of the dynamics of dust electric field can be approximated by effective dipole located at a half of the height of DD. This work was supported by the Russian Federation Presidential Program for State Support of Young Scientists (project no. MK-6935.2015.2).

  19. Dust storm events over Delhi: verification of dust AOD forecasts with satellite and surface observations

    NASA Astrophysics Data System (ADS)

    Singh, Aditi; Iyengar, Gopal R.; George, John P.

    2016-05-01

    Thar desert located in northwest part of India is considered as one of the major dust source. Dust storms originate in Thar desert during pre-monsoon season, affects large part of Indo-Gangetic plains. High dust loading causes the deterioration of the ambient air quality and degradation in visibility. Present study focuses on the identification of dust events and verification of the forecast of dust events over Delhi and western part of IG Plains, during the pre-monsoon season of 2015. Three dust events have been identified over Delhi during the study period. For all the selected days, Terra-MODIS AOD at 550 nm are found close to 1.0, while AURA-OMI AI shows high values. Dust AOD forecasts from NCMRWF Unified Model (NCUM) for the three selected dust events are verified against satellite (MODIS) and ground based observations (AERONET). Comparison of observed AODs at 550 nm from MODIS with NCUM predicted AODs reveals that NCUM is able to predict the spatial and temporal distribution of dust AOD, in these cases. Good correlation (~0.67) is obtained between the NCUM predicted dust AODs and location specific observations available from AERONET. Model under-predicted the AODs as compared to the AERONET observations. This may be mainly because the model account for only dust and no anthropogenic activities are considered. The results of the present study emphasize the requirement of more realistic representation of local dust emission in the model both of natural and anthropogenic origin, to improve the forecast of dust from NCUM during the dust events.

  20. Potential geographic distribution of two invasive cassava green mites.

    PubMed

    Parsa, Soroush; Hazzi, Nicolas A; Chen, Qing; Lu, Fuping; Herrera Campo, Beatriz Vanessa; Yaninek, John Stephen; Vásquez-Ordóñez, Aymer Andrés

    2015-02-01

    The cassava green mites Mononychellus tanajoa and M. mcgregori are highly invasive species that rank among the most serious pests of cassava globally. To guide the development of appropriate risk mitigation measures preventing their introduction and spread, this article estimates their potential geographic distribution using the maximum entropy approach to distribution modeling. We compiled 1,232 occurrence records for M. tanajoa and 99 for M. mcgregori, and relied on the WorldClim climate database as a source of environmental predictors. To mitigate the potential impact of uneven sampling efforts, we applied a distance correction filter resulting in 429 occurrence records for M. tanajoa and 55 for M. mcgregori. To test for environmental biases in our occurrence data, we developed models trained and tested with records from different continents, before developing the definitive models using the full record sets. The geographically-structured models revealed good cross-validation for M. tanajoa but not for M. mcgregori, likely reflecting a subtropical bias in M. mcgregori's invasive range in Asia. The definitive models exhibited very good performance and predicted different potential distribution patterns for the two species. Relative to M. tanajoa, M. mcgregori seems better adapted to survive in locations lacking a pronounced dry season, for example across equatorial climates. Our results should help decision-makers assess the site-specific risk of cassava green mite establishment, and develop proportional risk mitigation measures to prevent their introduction and spread. These results should be particularly timely to help address the recent detection of M. mcgregori in Southeast Asia.

  1. Rebamipide suppresses mite-induced asthmatic responses in NC/Nga mice.

    PubMed

    Murakami, Ikuo; Zhang, Ran; Kubo, Masayuki; Nagaoka, Kenjiro; Eguchi, Eri; Ogino, Keiki

    2015-10-15

    Allergic asthma caused by continuous allergen exposure evokes allergen-specific Th2 responses and is characterized by chronic airway inflammation and hyperresponsiveness. A previous report showed that rebamipide improved asthmatic symptoms in an ovalbumin/trypsin mice model. However, it is still unclear how rebamipide exerts its effects in asthma. In this study, rebamipide improved the asthmatic responses induced by mite exposure in NC/Nga mice, revealing the mechanism of this therapeutic effect. Rebamipide suppressed the infiltration of eosinophils into the airways and lung as well as attenuating the production of reactive oxygen species in tissues. In addition to these anti-inflammatory effects, rebamipide inhibited the production of IL-33, a member of the IL-1 family that drives the subsequent production of Th2-associated cytokines. These observations identify the point where rebamipide exerts its suppressive action on asthma and suggest that rebamipide has therapeutic potential in preventing mite-induced asthma. PMID:26472814

  2. MITE INFECTION IN A MASKED PALM CIVET (PAGUMA LARVATA) TREATED BY SELAMECTIN (STRONGHOLD®, PFIZER LTD.).

    PubMed

    Olivieri, Lara; Nardini, Giordano; Leopardi, Stefania; Abramo, Francesca

    2015-09-01

    The masked palm civet (Paguma larvata) is a small Asian mammal (order Carnivora, family Viverridae) uncommon in Italy. Limited information is available about management and sanitary maintenance in captivity. A 4-mo-old masked palm civet presented with pruritus, itch, scratching, and disorexia. On physical examination, alopecia and crusts were detected on the ventral and lateral trunk, tail, legs, and lips. Skin scrapings and cytology revealed Notoedres spp. and bacterial infection. On histopathology, parasitic dermatitis was observed with the presence of a Sarcoptidae mite and Demodex spp. Selamectin spot-on (15 mg/kg every 2 wk, three applications) and marbofloxacin per os (2.5 mg/kg once daily for 2 wk) were administered, and the animal recovered in 1 mo. With the good response to this therapy, a notoedric mange was thought to be the main problem. This is the first report about the use of selamectin to treat a mite infection in masked palm civet. PMID:26352967

  3. Infestation of grasses by eriophyoid mites (Acari: Eriophyoidea) in Turkey

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite the economic importance of eriophyoid mites as agricultural pests, especially of cereal crops, knowledge of the eriophyoid fauna in Turkey remains incomplete. This paper presents the results of a 3-year study on grass-infesting eriophyoid mites in Turkey. The aim of this study was to collect...

  4. A sampling procedure for quantifying mites in soybeans.

    PubMed

    Storck, Lindolfo; Fiorin, Rubens Alex; Filho, Alberto Cargnelutti; Guedes, Jerson Vanderlei Carus

    2012-06-01

    To control phytophagous mites on soybean crops in an economically viable way, it is necessary to quantify the occurrence of the mites on the leaflets. Estimating the number of mites cm(-2) on leaflets is more difficult because of their irregular distribution on the leaflet surface. Therefore, the aim of this study was to determine the count-area/leaflet and the number of soybean leaflets to quantify the mites. One hundred infested plants were randomly collected. One leaflet was removed from each plant and divided into 32 sections (1.0 cm(2) per section), arranged in four columns and eight rows, to count the mites (adults, nymphs and eggs). The ideal count-area size per leaflet (Xo) was estimated by the maximum curvature of the coefficient of variation method for each of the 100 leaflets. For a count-area of Xo size, we obtained the number of mites cm(-2) per leaflet and, using the bootstrap resampling method, we estimated the point and interval averages as well as the sample size for a pre-established error. We suggest that the determination of the evaluated area size on each soybean leaflet (20 cm(2) in this case) and the bootstrap resampling estimate of the appropriate number of leaflets (12 in this case) for a bootstrap confidence interval of four mites (adults + nymphs) cm(-2) is sufficient to standardize the sampling-procedures for quantifying mites on soybean leaflets.

  5. Red Palm Mite Situation in the Caribbean and Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The red palm mite (Raoiella indica Hirst Tenuipalpidae), a pest of coconuts and ornamental palms in Asia and Africa, was reported in the Caribbean in 2004. By 2008, it had spread to at least twelve islands, two counties in Florida and to Venezuela. Red palm mite causes yellowing and leaf necrosis wi...

  6. Prenatal Chemosensory Learning by the Predatory Mite Neoseiulus californicus

    PubMed Central

    Peralta Quesada, Paulo C.; Schausberger, Peter

    2012-01-01

    Background Prenatal or embryonic learning, behavioral change following experience made prior to birth, may have significant consequences for postnatal foraging behavior in a wide variety of animals, including mammals, birds, fish, amphibians, and molluscs. However, prenatal learning has not been previously shown in arthropods such as insects, spiders and mites. Methodology/Principal Findings We examined prenatal chemosensory learning in the plant-inhabiting predatory mite Neoseiulus californicus. We exposed these predators in the embryonic stage to two flavors (vanillin or anisaldehyde) or no flavor (neutral) by feeding their mothers on spider mite prey enriched with these flavors or not enriched with any flavor (neutral). After the predators reached the protonymphal stage, we assessed their prey choice through residence and feeding preferences in experiments, in which they were offered spider mites matching the maternal diet (neutral, vanillin or anisaldehyde spider mites) and non-matching spider mites. Predator protonymphs preferentially resided in the vicinity of spider mites matching the maternal diet irrespective of the type of maternal diet and choice situation. Across treatments, the protonymphs preferentially fed on spider mites matching the maternal diet. Prey and predator sizes did not differ among neutral, vanillin and anisaldehyde treatments, excluding the hypothesis that size-assortative predation influenced the outcome of the experiments. Conclusions/Significance Our study reports the first example of prenatal learning in arthropods. PMID:23300897

  7. Allexivirus transmitted by eriophyid mites in garlic plants.

    PubMed

    Kang, Sang Gu; Koo, Bong Jin; Lee, Eun Tag; Chang, Moo Ung

    2007-11-01

    Viruses in garlic plants (Allium sativum L.) have accumulated and evolved over generations, resulting in serious consequences for the garlic trade around the world. These viral epidemics are also known to be caused by aphids and eriophyid mites (Aceria tulipae) carrying Potyviruses, Carlaviruses, and Allexiviruses. However, little is known about viral epidemics in garlic plants caused by eriophyid mites. Therefore, this study investigated the infection of garlic plants with Allexiviruses by eriophyid mites. When healthy garlic plants were cocultured with eriophyid mites, the leaves of the garlic plants developed yellow mosaic strips and became distorted. In extracts from the eriophyid mites, Allexiviruses were observed using immunosorbent electron microscopy (ISEM). From an immunoblot analysis, coat proteins against an Allexivirus garlic-virus antiserum were clearly identified in purified extracts from collected viral-infected garlic plants, eriophyid mites, and garlic plants infected by eriophyid mites. A new strain of GarV-B was isolated and named GarV-B Korea isolate 1 (GarV-B1). The ORF1 and ORF2 in GarV-B1 contained a typical viral helicase, RNA-directed RNA polymerase (RdRp), and triple gene block protein (TGBp) for viral movement between cells. The newly identified GarV-B1 was phylogenetically grouped with GarV-C and GarV-X in the Allexivirus genus. All the results in this study demonstrated that eriophyid mites are a transmitter insect species for Allexiviruses. PMID:18092468

  8. Genetic Variation in Jasmonic Acid- and Spider Mite-Induced Plant Volatile Emission of Cucumber Accessions and Attraction of the Predator Phytoseiulus persimilis

    PubMed Central

    Verstappen, Francel W. A.; Luckerhoff, Ludo L. P.; Bouwmeester, Harro J.; Dicke, Marcel

    2010-01-01

    Cucumber plants (Cucumis sativus L.) respond to spider–mite (Tetranychus urticae) damage with the release of specific volatiles that are exploited by predatory mites, the natural enemies of the spider mites, to locate their prey. The production of volatiles also can be induced by exposing plants to the plant hormone jasmonic acid. We analyzed volatile emissions from 15 cucumber accessions upon herbivory by spider mites and upon exposure to jasmonic acid using gas chromatography—mass spectrometry. Upon induction, cucumber plants emitted over 24 different compounds, and the blend of induced volatiles consisted predominantly of terpenoids. The total amount of volatiles was higher in plants treated with jasmonic acid than in those infested with spider mites, with (E)-4,8-dimethyl-1,3,7-nonatriene, (E,E)-α-farnesene, and (E)-β-ocimene as the most abundant compounds in all accessions in both treatments. Significant variation among the accessions was found for the 24 major volatile compounds. The accessions differed strongly in total amount of volatiles emitted, and displayed very different odor profiles. Principal component analysis performed on the relative quantities of particular compounds within the blend revealed clusters of highly correlated volatiles, which is suggestive of common metabolic pathways. A number of cucumber accessions also were tested for their attractiveness to Phytoseiulus persimilis, a specialist predator of spider mites. Differences in the attraction of predatory mites by the various accessions correlated to differences in the individual chemical profiles of these accessions. The presence of genetic variation in induced plant volatile emission in cucumber shows that it is possible to breed for cucumber varieties that are more attractive to predatory mites and other biological control agents. PMID:20383796

  9. Numerical simulation of a continental-scale Saharan dust event

    NASA Astrophysics Data System (ADS)

    Shao, Yaping; Fink, Andreas H.; Klose, Martina

    2010-07-01

    Using an integrated dust-storm modeling system, we simulate the severe Saharan dust episode between 1 and 10 March 2004. The simulations are compared with surface synoptic data and satellite images and are found to agree well with the observations. The synoptic systems that generated the dust storms and the evolution of the dust patterns are analyzed. It is revealed that a cyclogenesis over central Sahara, accompanied by an anticyclone over the Atlantic and a monsoon trough in the tropics, was responsible for the widespread continental-scale dust storms in North Africa. Dust first appeared in west Sahara, then in east Sahara and much of the dust emitted from east Sahara was transported to the monsoon trough, resulting in high concentrations of suspended dust over the Sahel (column dust load up to 10 g m-2). The main dust source regions were (1) Mauritania, (2) Chad and Niger, and (3) Libya, Egypt, and Sudan. The region between 10°N and 17°N was one of net dust deposition. We estimate that 715.8 megatons (Mt) of dust was emitted from North Africa during the episode, 608.2 Mt of which was deposited to the continent, and the net dust emission was 107.6 Mt. Of the 107.6 Mt, with respect to the model domain, 7.3 Mt was deposited to the ocean, 79.8 Mt was transported across the domain boundaries, and 20.5 Mt was suspended in the atmosphere.

  10. In-situ dust detection as a tool to study dust-plasma interactions in the Solar System

    NASA Astrophysics Data System (ADS)

    Srama, R.; Hsu, H. W.; Moragas-Klostermeyer, G.; Postberg, F.; Kempf, S.

    2014-12-01

    The unique results of the Cassini Cosmic Dust Analyzer onboard Cassini revealed the potential of in-situ dust detection for the study of dust-plasma interactions. In-situ techniques are charge induction, impact ionization, momentum transfer, foil depolarization, light scattering or mass spectrometry. Modern instruments like dust telescopes or the Cosmic Dust Analyzer (CDA) onboard Cassini combine different methods in one sensor. This paper gives an overview about in-situ dust measurements in space using direct detection methods. A focus is given to charge induction and impact ionization and their measurement thresholds are described. Major CDA discoveries are summarized and new results of nano-dust stream measurements in the outer Saturnian system are presented. These data show periodicities related to Saturn and its moons, leading to a deeper understanding of nano-dust origins and dynamics in Saturn's magnetosphere.

  11. Do plant mites commonly prefer the underside of leaves?

    PubMed

    Sudo, Masaaki; Osakabe, Masahiro

    2011-09-01

    The adaxial (upper) and abaxial (lower) surfaces of a plant leaf provide heterogeneous habitats for small arthropods with different environmental conditions, such as light, humidity, and surface morphology. As for plant mites, some agricultural pest species and their natural enemies have been observed to favor the abaxial leaf surface, which is considered an adaptation to avoid rain or solar ultraviolet radiation. However, whether such a preference for the leaf underside is a common behavioral trait in mites on wild vegetation remains unknown. The authors conducted a 2-year survey on the foliar mite assemblage found on Viburnum erosum var. punctatum, a deciduous shrub on which several mite taxa occur throughout the seasons, and 14 sympatric tree or shrub species in secondary broadleaf-forest sites in Kyoto, west-central Japan. We compared adaxial-abaxial surface distributions of mites among mite taxa, seasons, and morphology of host leaves (presence/absence of hairs and domatia). On V. erosum var. punctatum, seven of 11 distinguished mite taxa were significantly distributed in favor of abaxial leaf surfaces and the trend was seasonally stable, except for Eriophyoidea. Mite assemblages on 15 plant species were significantly biased towards the abaxial leaf surfaces, regardless of surface morphology. Our data suggest that many mite taxa commonly prefer to stay on abaxial leaf surfaces in wild vegetation. Oribatida displayed a relatively neutral distribution, and in Tenuipalpidae, the ratio of eggs collected from the adaxial versus the abaxial side was significantly higher than the ratio of the motile individuals, implying that some mite taxa exploit adaxial leaf surfaces as habitat. PMID:21472503

  12. Do plant mites commonly prefer the underside of leaves?

    PubMed

    Sudo, Masaaki; Osakabe, Masahiro

    2011-09-01

    The adaxial (upper) and abaxial (lower) surfaces of a plant leaf provide heterogeneous habitats for small arthropods with different environmental conditions, such as light, humidity, and surface morphology. As for plant mites, some agricultural pest species and their natural enemies have been observed to favor the abaxial leaf surface, which is considered an adaptation to avoid rain or solar ultraviolet radiation. However, whether such a preference for the leaf underside is a common behavioral trait in mites on wild vegetation remains unknown. The authors conducted a 2-year survey on the foliar mite assemblage found on Viburnum erosum var. punctatum, a deciduous shrub on which several mite taxa occur throughout the seasons, and 14 sympatric tree or shrub species in secondary broadleaf-forest sites in Kyoto, west-central Japan. We compared adaxial-abaxial surface distributions of mites among mite taxa, seasons, and morphology of host leaves (presence/absence of hairs and domatia). On V. erosum var. punctatum, seven of 11 distinguished mite taxa were significantly distributed in favor of abaxial leaf surfaces and the trend was seasonally stable, except for Eriophyoidea. Mite assemblages on 15 plant species were significantly biased towards the abaxial leaf surfaces, regardless of surface morphology. Our data suggest that many mite taxa commonly prefer to stay on abaxial leaf surfaces in wild vegetation. Oribatida displayed a relatively neutral distribution, and in Tenuipalpidae, the ratio of eggs collected from the adaxial versus the abaxial side was significantly higher than the ratio of the motile individuals, implying that some mite taxa exploit adaxial leaf surfaces as habitat.

  13. Housing and dustbathing effects on northern fowl mites (Ornithonyssus sylviarum) and chicken body lice (Menacanthus stramineus) on hens.

    PubMed

    Martin, C D; Mullens, B A

    2012-09-01

    Hen housing (cage or cage-free) did not impact overall abundances of northern fowl mites, Ornithonyssus sylviarum (Canestrini & Fanzago) (Acari: Macronyssidae), or chicken body lice, Menacanthus stramineus (Nitzsch) (Phthiraptera: Menoponidae). Cage-free hens received a dustbox with sand plus diatomaceous earth (DE), kaolin clay or sulphur. Weekly use varied from none to 100% of hens; 73% of hens used the dustbox at least once. Ectoparasite populations on dustbathing hens (users) were compared with those on non-user cage-free and caged hens. All materials reduced ectoparasites on user hens by 80-100% after 1 week of dustbox use. Diatomaceous earth and kaolin failed to reduce ectoparasites on non-user hens, and ectoparasites on user hens recovered after dustbox removal. A sulphur dustbox eliminated mites from all hens (including non-users) within 2-4 weeks. Residual sulphur controlled mites until the end of the experiment (up to 9 weeks), even after the dustbox was removed. Louse populations on hens using the sulphur dustbox were reduced in 1-2 weeks. Residual sulphur effects were less evident in lice, but the use of a sulphur dustbox by a higher proportion of hens extended louse control to all hens. This is the first experimental study to show that bird dustbathing in naturally and widely available dust materials (particularly kaolin) can suppress ectoparasites and thus the behaviour is probably adaptive. PMID:22458590

  14. Laboratory tests for controlling poultry red mites (Dermanyssus gallinae) with predatory mites in small 'laying hen' cages.

    PubMed

    Lesna, Izabela; Sabelis, Maurice W; van Niekerk, Thea G C M; Komdeur, Jan

    2012-12-01

    To assess their potential to control poultry red mites (Dermanyssus gallinae), we tested selected predaceous mites (Androlaelaps casalis and Stratiolaelaps scimitus) that occur naturally in wild bird nests or sometimes spontaneously invade poultry houses. This was done under laboratory conditions in cages, each with 2-3 laying hens, initially 300 poultry red mites and later the release of 1,000 predators. These small-scale tests were designed to prevent mite escape from the cages and they were carried out in three replicates at each of three temperature regimes: 26, 30 (constant day and night) and 33-25 °C (day-night cycle). After 6 weeks total population sizes of poultry red mites and predatory mites were assessed. For the temperature regimes of 26 and 33/25 °C S. scimitus reduced the poultry red mite population relative to the control experiments by a factor 3 and 30, respectively, and A. casalis by a factor of 18 and 55, respectively. At 30 °C the predators had less effect on red mites, with a reduction of 1.3-fold for S. scimitus and 5.6-fold for A. casalis. This possibly reflected hen manure condition or an effect of other invertebrates in the hen feed. Poultry red mite control was not negatively affected by temperatures as high as 33 °C and was always better in trials with A. casalis than in those with S. scimitus. In none of the experiments predators managed to eradicate the population of poultry red mites. This may be due to a prey refuge effect since most predatory mites were found in and around the manure tray at the bottom of the cage, whereas most poultry red mites were found higher up in the cage (i.e. on the walls, the cover, the perch, the nest box and the food box). The efficacy of applying predatory mites in the poultry industry may be promoted by reducing this refuge effect, boosting predatory mite populations using alternative prey and prolonged predator release devices. Biocontrol success, however, will strongly depend on how the poultry is

  15. Laboratory tests for controlling poultry red mites (Dermanyssus gallinae) with predatory mites in small 'laying hen' cages.

    PubMed

    Lesna, Izabela; Sabelis, Maurice W; van Niekerk, Thea G C M; Komdeur, Jan

    2012-12-01

    To assess their potential to control poultry red mites (Dermanyssus gallinae), we tested selected predaceous mites (Androlaelaps casalis and Stratiolaelaps scimitus) that occur naturally in wild bird nests or sometimes spontaneously invade poultry houses. This was done under laboratory conditions in cages, each with 2-3 laying hens, initially 300 poultry red mites and later the release of 1,000 predators. These small-scale tests were designed to prevent mite escape from the cages and they were carried out in three replicates at each of three temperature regimes: 26, 30 (constant day and night) and 33-25 °C (day-night cycle). After 6 weeks total population sizes of poultry red mites and predatory mites were assessed. For the temperature regimes of 26 and 33/25 °C S. scimitus reduced the poultry red mite population relative to the control experiments by a factor 3 and 30, respectively, and A. casalis by a factor of 18 and 55, respectively. At 30 °C the predators had less effect on red mites, with a reduction of 1.3-fold for S. scimitus and 5.6-fold for A. casalis. This possibly reflected hen manure condition or an effect of other invertebrates in the hen feed. Poultry red mite control was not negatively affected by temperatures as high as 33 °C and was always better in trials with A. casalis than in those with S. scimitus. In none of the experiments predators managed to eradicate the population of poultry red mites. This may be due to a prey refuge effect since most predatory mites were found in and around the manure tray at the bottom of the cage, whereas most poultry red mites were found higher up in the cage (i.e. on the walls, the cover, the perch, the nest box and the food box). The efficacy of applying predatory mites in the poultry industry may be promoted by reducing this refuge effect, boosting predatory mite populations using alternative prey and prolonged predator release devices. Biocontrol success, however, will strongly depend on how the poultry is

  16. Detection of anthropogenic dust using CALIPSO lidar measurements

    NASA Astrophysics Data System (ADS)

    Huang, J. P.; Liu, J. J.; Chen, B.; Nasiri, S. L.

    2015-10-01

    Anthropogenic dusts are those produced by human activities on disturbed soils, which are mainly cropland, pastureland, and urbanized regions, and are a subset of the total dust load which includes natural sources from desert regions. Our knowledge of anthropogenic dusts is still very limited due to a lack of data. To understand the contribution of anthropogenic dust to the total global dust load, it is important to identify it apart from total dust. In this study, a new technique for distinguishing anthropogenic dust from natural dust is proposed by using Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) dust and planetary boundary layer (PBL) height retrievals along with a land use data set. Using this technique, the global distribution of dust is analyzed and the relative contribution of anthropogenic and natural dust sources to regional and global emissions are estimated. Results reveal that local anthropogenic dust aerosol due to human activity, such as agriculture, industrial activity, transportation, and overgrazing, accounts for about 25 % of the global continental dust load. Of these anthropogenic dust aerosols, more than 53 % come from semi-arid and semi-wet regions. Annual mean anthropogenic dust column burden (DCB) values range from 0.42 g m-2, with a maximum in India, to 0.12 g m-2, with a minimum in North America. A better understanding of anthropogenic dust emission will enable us to focus on human activities in these critical regions and with such knowledge we will be more able to improve global dust models and to explore the effects of anthropogenic emission on radiative forcing, climate change, and air quality in the future.

  17. Detection of anthropogenic dust using CALIPSO lidar measurements

    NASA Astrophysics Data System (ADS)

    Huang, J.; Liu, J.; Chen, B.; Nasiri, S. L.

    2015-04-01

    Anthropogenic dusts are those produced by human activities on disturbed soils, which are mainly cropland, pasture, and urbanized regions and are a subset of the total dust load which includes natural sources from desert regions. Our knowledge of anthropogenic dusts is still very limited due to a lack of data on source distribution and magnitude, and on their effect on radiative forcing which may be comparable to other anthropogenic aerosols. To understand the contribution of anthropogenic dust to the total global dust load and its effect on radiative transfer and climate, it is important to identify them from total dust. In this study, a new technique for distinguishing anthropogenic dust from natural dust is proposed by using Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) dust and planetary boundary layer (PBL) height retrievals along with a land use dataset. Using this technique, the global distribution of dust is analyzed and the relative contribution of anthropogenic and natural dust sources to regional and global emissions are estimated. Results reveal that local anthropogenic dust aerosol due to human activity, such as agriculture, industrial activity, transportation, and overgrazing, accounts for about 25% of the global continental dust load. Of these anthropogenic dust aerosols, more than 53% come from semi-arid and semi-wet regions. Annual mean anthropogenic dust column burden (DCB) values range from 0.42 g m-2 with a maximum in India to 0.12 g m-2 with a minimum in North America. A better understanding of anthropogenic dust emission will enable us to focus on human activities in these critical regions and with such knowledge we will be better able to improve global dust models and to explore the effects of anthropogenic emission on radiative forcing, climate change and air quality in the future.

  18. Allergies, asthma, and dust

    MedlinePlus

    ... much dust. Dust particles collect in fabrics and carpets. If you can, get rid of fabric or ... are covered in cloth. Replace wall-to-wall carpet with wood or other hard flooring. Since mattresses, ...

  19. Niamey Dust Observations

    DOE Data Explorer

    Flynn, Connor

    2008-10-01

    Niamey aerosol are composed of two main components: dust due to the proximity of the Sahara Desert, and soot from local and regional biomass burning. The purpose of this data product is to identify when the local conditions are dominated by the dust component so that the properties of the dust events can be further studied.

  20. Middle East Dust

    Atmospheric Science Data Center

    2013-04-16

    ... (nadir) camera. Here only some of the dust over eastern Syria and southeastern Turkey can be discerned. The dust is much more obvious ... October 18, 2002 - A large dust plume extends across Syria and Turkey. project:  MISR category:  ...

  1. China Dust and Sand

    Atmospheric Science Data Center

    2013-04-16

    ... article title:  Dust and Sand Sweep Over Northeast China     View Larger Image ... these views of the dust and sand that swept over northeast China on March 10, 2004. Information on the height of the dust and an ...

  2. Dust in the Universe

    ERIC Educational Resources Information Center

    Hemenway, Mary Kay; Armosky, Brad J.

    2004-01-01

    Space is seeming less and less like empty space as new discoveries and reexaminations fill in the gaps. And, ingenuity and technology, like the Spitzer Space Telescope, is allowing examination of the far reaches of the Milky Way and beyond. Even dust is getting its due, but not the dust everyone is familiar with. People seldom consider the dust in…

  3. Orbital Observations of Dust Lofted by Daytime Convective Turbulence

    NASA Astrophysics Data System (ADS)

    Fenton, Lori; Reiss, Dennis; Lemmon, Mark; Marticorena, Béatrice; Lewis, Stephen; Cantor, Bruce

    2016-03-01

    Over the past several decades, orbital observations of lofted dust have revealed the importance of mineral aerosols as a climate forcing mechanism on both Earth and Mars. Increasingly detailed and diverse data sets have provided an ever-improving understanding of dust sources, transport pathways, and sinks on both planets, but the role of dust in modulating atmospheric processes is complex and not always well understood. We present a review of orbital observations of entrained dust on Earth and Mars, particularly that produced by the dust-laden structures produced by daytime convective turbulence called "dust devils". On Earth, dust devils are thought to contribute only a small fraction of the atmospheric dust budget; accordingly, there are not yet any published accounts of their occurrence from orbit. In contrast, dust devils on Mars are thought to account for several tens of percent of the planet's atmospheric dust budget; the literature regarding martian dust devils is quite rich. Because terrestrial dust devils may temporarily contribute significantly to local dust loading and lowered air quality, we suggest that martian dust devil studies may inform future studies of convectively-lofted dust on Earth. As on Earth, martian dust devils form most commonly when the insolation reaches its daily and seasonal peak and where a source of loose dust is plentiful. However this pattern is modulated by variations in weather, albedo, or topography, which produce turbulence that can either enhance or suppress dust devil formation. For reasons not well understood, when measured from orbit, martian dust devil characteristics (dimensions, and translational and rotational speeds) are often much larger than those measured from the ground on both Earth and Mars. Studies connecting orbital observations to those from the surface are needed to bridge this gap in understanding. Martian dust devils have been used to remotely probe conditions in the PBL (e.g., CBL depth, wind velocity

  4. Coincidental intraguild predation by caterpillars on spider mites.

    PubMed

    Shirotsuka, Kanako; Yano, Shuichi

    2012-01-29

    Intraguild predation (IGP) is defined as the killing and eating of prey species by a predator that also can utilize the resources of the prey. It is mainly reported among carnivores that share common herbivorous prey. However, a large chewing herbivore could prey upon sedentary and/or micro herbivores in addition to utilizing a host plant. To investigate such coincidental IGP, we observed the behavioral responses of the polyphagous mite Tetranychus kanzawai Kishida (Acari: Tetranychidae) when its host plant Cayratia japonica (Thunb.) Gagnep. (Vitaceae) was attacked by hornworms, Theretra japonica Boisduval (Sphingidae) and T. oldenlandiae Fabricius (Sphingidae). We also examined an interaction between the oligophagous mite Panonychus citri McGregor (Acari: Tetranychidae) and caterpillars of the swallowtail Papilio xuthus L. (Papilionidae) that share citrus plants as their main food source. Although all T. kanzawai and some active stage P. citri tried to escape from the coincidental IGP, some were consumed together with eggs, quiescent mites, and host plant leaves, suggesting that coincidental IGP occurs on spider mites in the wild. Moreover, neither hornworms nor swallowtail caterpillars distinguished between spider mite-infested and uninfested leaves, suggesting that the mite-infested leaves do not discourage caterpillar feeding. The reasons that the mites have no effective defense against coincidental IGP other than escaping are discussed.

  5. The use of soil mites in ecotoxicology: a review.

    PubMed

    Huguier, Pierre; Manier, Nicolas; Owojori, Olugbenga John; Bauda, Pascale; Pandard, Pascal; Römbke, Jörg

    2015-01-01

    Mites, and especially soil-inhabiting ones, have been less studied than the other invertebrates used in bio-assays for the assessment of soil quality and the hazards of chemicals, although these organisms are included in the regulatory assessment scheme of pesticides. The recent advances in the development of test methods for soil mites groups have provided more information on their sensitivities towards chemicals, which needs to be presented for a more robust assessment of the current trends in soil mite ecotoxicology. Moreover, interestingly mite is the only taxa for which test methods were developed and standardized on predatory organisms. This review summarizes the different protocols for the assessment of chemicals using soil-inhabiting mites, including laboratory, semi-field and field studies. Among the data found in the literature, most of the chemicals assessed with mites were pesticides, while a few environmental samples were assessed with these organisms. Their sensitivities towards chemicals were then compared and discussed regarding other soil invertebrates. Finally, we conclude on the usefulness of soil mites in ecotoxicology, and provide future research trail in this area.

  6. Phoretic mites identified on Andean hummingbirds (Trochilidae) of Caldas, Colombia.

    PubMed

    López-Orozco, Natalia; Cañón-Franco, William Alberto

    2013-01-01

    Within the bird-plant-mite system, the relationship between hummingbirds, flowers, and mites remains poorly understood. In this study, we evaluated the degree of association between nasal mites and eight species of Andean hummingbirds in Colombia (Amazilia saucerrottei, A. tzacatl, Chalybura buffonii, Chlorostilbon mellisugus, Florisuga mellivora, Glaucis hirsutus, Phaethornis guy and P. striigularis). Over a five-month period (trapping effort 360 hours/month), a total of 178 birds were captured, from which 81 mite specimens were collected and identified as belonging to three genera (Proctolaelaps, Rhinoseius and Tropicoseius) spanning eleven species. This is the first report of its kind from Colombia on the identification of the mite species P. rabulatus, R. luteyni, R. rafinskii, T. berryi, T. colwelli, T. erro and T. uniformis and the first record of P. guy as phoretic host for Proctolaelaps rabulatus. Morphological characteristics (length of the dorsal plate, width of the dorsal plate and setae z5 length) alone failed to distinguish between mite species. The ecologic impact of this relationship on flowers with respect to nectar and pollen availability and the effect of mites on pollination by hummingbirds needs to be determined.

  7. Bartonella-like bacteria carried by domestic mite species.

    PubMed

    Kopecký, Jan; Nesvorná, Marta; Hubert, Jan

    2014-01-01

    Bacteria of the genus Bartonella are carried by haematophagous mites, ticks, fleas and flies, and attack the erythrocytes of mammals. Here we describe a Bartonella-like clade, a distinct group related to Bartonellaceae, in stored-product mites (Acari: Astigmata) and a predatory mite Cheyletus eruditus (Acari: Prostigmata) based on the analysis of cloned 16S rRNA gene sequences. By using the clade-specific primers, closely related Bartonella-like 16S rRNA sequences were amplified from both laboratory colonies and field strains of three synanthropic mite species (Acarus siro, Lepidoglyphus destructor and Tyrophagus putrescentiae) and a predatory mite. Altogether, sequences of Bartonella-like bacteria were found in 11 strains, but were not detected in Dermatophagoides farinae and D. pteronyssinus and two strains of L. destructor. All obtained sequences formed a separate cluster branching as a sister group to Bartonellaceae and related to other separate clusters comprising uncultured bacterial clones from human skin and hemipteran insects (Nysius plebeius and Nysius sp.). The classification of sequences into operational taxonomic units (OTUs) showed a difference between A. siro and T. putrescentiae suggesting that the Bartonella-like bacteria are different in these two mite species. However, species specific sequences in separate OTUs were observed also for C. eruditus. Possible symbiotic interactions between Bartonella-like bacteria and their mite hosts are discussed.

  8. Amensalism via webs causes unidirectional shifts of dominance in spider mite communities.

    PubMed

    Osakabe, Masahiro; Hongo, Kimiko; Funayama, Ken; Osumi, Senichi

    2006-12-01

    Competitive displacement is considered the most severe consequence of interspecific competition; if a superior competitor invades the habitat of an inferior species, the inferior species will be displaced. Most displacements previously reported among arthropods were caused by exotic species. The lack of investigation of displacement among native species may be due to their apparently harmonious coexistence, even if it is equivalent to an outcome of interspecific association. A seasonal change in the species composition of spider mites, from Panonychus ulmi to Tetranychus urticae, is observed in apple trees worldwide. Previous laboratory experiments have revealed amensal effects of T. urticae on P. ulmi via their webs. Using manipulation experiments in an orchard, we tested whether this seasonal change in species composition occurred as the result of interspecific competition between these spider mites. Invasion by T. urticae prevented an increase in P. ulmi densities throughout the experimental periods. Degree of overlap relative to the independent distribution on a leaf-surface basis (omega (S)) changed from positive to negative with increasing density of T. urticae. T. urticae invasion drove P. ulmi toward upper leaf surfaces (competitor-free space). The niche adjustment by P. ulmi occurred between leaf surfaces but not among leaves. Our findings show that asymmetrical competition between T. urticae and P. ulmi plays an important role in this unidirectional displacement and that the existence of refuges within a leaf produces the apparently harmonious coexistence of the mites and obscures their negative association. PMID:17024380

  9. Field bioassay of Metarhizium anisopliae strains to control the poultry red mite Dermanyssus gallinae.

    PubMed

    Tavassoli, M; Allymehr, M; Pourseyed, S H; Ownag, A; Bernousi, I; Mardani, K; Ghorbanzadegan, M; Shokrpoor, S

    2011-06-10

    The poultry red mite, Dermanyssus gallinae is one of the most economically deleterious ectoparasite of laying hens worldwide. To evaluate the efficacy of three strains (V245, 3247 and 715C) of entomopathogenic fungus Metarhizium anisopliae with potential as acaricides against D. gallinae, this investigation was carried out in a commercial caged laying poultry farm in Naghedeh, West Azarbaijan of Iran. The parasite infestation already existed in the farm. Sunflower oil suspension of all fungal strains, each in two concentrations (1×10(7) and 1×10(9) conidia/ml) were used separately as spray on hens and cages, and in the control group the cages were only sprayed with sunflower oil and sterile distilled water. For estimating the population rate of mites before and after treatment, special cardboard traps were fixed to cages during a 1-month period. The traps were placed on weeks -1, 0, 1, 2 and 3 and always removed after 1 w. The results showed that the population rates post fungal treatment with the lower concentration were not significantly different compared to the control group. However, the reduction in mite numbers induced by all three strains at the concentration of 1×10(9) conidia/ml was significantly higher than the control (P<0.05). The results revealed that under field conditions, higher concentrations of M. anisopliae will be required for controlling D. gallinae.

  10. Zodiacal Dust: Measurements by Mariner IV.

    PubMed

    Alexander, W M; McCracken, C W; Bohn, J L

    1965-09-10

    Data from the Mariner IV dust-particle experiment reveal an increase by a factor of 5 in the flux of interplanetary dust particles as the heliocentric distance from the sun increases. There is a variation in the slope of the cumulative flux-mass distribution, with the steepest slope for the distribution occurring between the planets. No enhancement of the flux in the vicinity of Mars was detected.

  11. A rapid survey technique for Tropilaelaps mite (Mesostigmata: Laelapidae) detection.

    PubMed

    Pettis, Jeffery S; Rose, Robyn; Lichtenberg, Elinor M; Chantawannakul, Panuwan; Buawangpong, Ninat; Somana, Weeraya; Sukumalanand, Prachaval; Vanengelsdorp, Dennis

    2013-08-01

    Parasitic Tropilaelaps (Delfinado and Baker) mites are a damaging pest of European honey bees (Apis mellifera L.) in Asia. These mites represent a significant threat if introduced to other regions of the world, warranting implementation of Tropilaelaps mite surveillance in uninfested regions. Current Tropilaelaps mite-detection methods are unsuitable for efficient large scale screening. We developed and tested a new bump technique that consists of firmly rapping a honey bee brood frame over a collecting pan. Our method was easier to implement than current detection tests, reduced time spent in each apiary, and minimized brood destruction. This feasibility increase overcomes the test's decreased rate of detecting infested colonies (sensitivity; 36.3% for the bump test, 54.2% and 56.7% for the two most sensitive methods currently used in Asia). Considering this sensitivity, we suggest that screening programs sample seven colonies per apiary (independent of apiary size) and 312 randomly selected apiaries in a region to be 95% sure of detecting an incipient Tropilaelaps mite invasion. Further analyses counter the currently held view that Tropilaelaps mites prefer drone bee brood cells. Tropilaelaps mite infestation rate was 3.5 +/- 0.9% in drone brood and 5.7 +/- 0.6% in worker brood. We propose the bump test as a standard tool for monitoring of Tropilaelaps mite presence in regions thought to be free from infestation. However, regulators may favor the sensitivity of the Drop test (collecting mites that fall to the bottom of a hive on sticky boards) over the less time-intensive Bump test.

  12. A rapid survey technique for Tropilaelaps mite (Mesostigmata: Laelapidae) detection.

    PubMed

    Pettis, Jeffery S; Rose, Robyn; Lichtenberg, Elinor M; Chantawannakul, Panuwan; Buawangpong, Ninat; Somana, Weeraya; Sukumalanand, Prachaval; Vanengelsdorp, Dennis

    2013-08-01

    Parasitic Tropilaelaps (Delfinado and Baker) mites are a damaging pest of European honey bees (Apis mellifera L.) in Asia. These mites represent a significant threat if introduced to other regions of the world, warranting implementation of Tropilaelaps mite surveillance in uninfested regions. Current Tropilaelaps mite-detection methods are unsuitable for efficient large scale screening. We developed and tested a new bump technique that consists of firmly rapping a honey bee brood frame over a collecting pan. Our method was easier to implement than current detection tests, reduced time spent in each apiary, and minimized brood destruction. This feasibility increase overcomes the test's decreased rate of detecting infested colonies (sensitivity; 36.3% for the bump test, 54.2% and 56.7% for the two most sensitive methods currently used in Asia). Considering this sensitivity, we suggest that screening programs sample seven colonies per apiary (independent of apiary size) and 312 randomly selected apiaries in a region to be 95% sure of detecting an incipient Tropilaelaps mite invasion. Further analyses counter the currently held view that Tropilaelaps mites prefer drone bee brood cells. Tropilaelaps mite infestation rate was 3.5 +/- 0.9% in drone brood and 5.7 +/- 0.6% in worker brood. We propose the bump test as a standard tool for monitoring of Tropilaelaps mite presence in regions thought to be free from infestation. However, regulators may favor the sensitivity of the Drop test (collecting mites that fall to the bottom of a hive on sticky boards) over the less time-intensive Bump test. PMID:24020263

  13. Host inflammatory response governs fitness in an avian ectoparasite, the northern fowl mite (Ornithonyssus sylviarum).

    PubMed

    Owen, Jeb P; Delany, Mary E; Cardona, Carol J; Bickford, Arthur A; Mullens, Bradley A

    2009-06-01

    Vertebrate immune responses to ectoparasites influence pathogen transmission and host fitness costs. Few studies have characterized natural immune responses to ectoparasites and resultant fitness effects on the ectoparasite. These are critical gaps in understanding vertebrate-ectoparasite interaction, disease ecology and host-parasite co-adaptation. This study focused on an ectoparasite of birds--the northern fowl mite (NFM) (Ornithonyssus sylviarum). Based on prior evidence that chickens develop resistance to NFM, these experiments tested two hypotheses: (i) skin inflammation blocks mite access to blood,impairing development, reproduction and survival; and (ii) host immunogenetic variation influences the inflammatory response and subsequent effects on the ectoparasite. On infested hosts, histology of skin inflammation revealed increased epidermal cell number and size, immigration of leukocytes and deposition of serous exudates on the skin surface. Survival of adult mites and their offspring decreased as the area of skin inflammation increased during an infestation. Inflammation increased the distance to blood vessels beyond the length of mite mouthparts (100-160 lm) and prevented protonymphs and adults from reaching a blood source. Consequently, protonymphs could not complete development, evidenced by a significant inverse relationship between inflammation and protonymph feeding success, as well as an increasing protonymph/adult ratio. Adult females were unable to feed and reproduce, indicated by an inverse relationship between inflammation and egg production, and decreasing female/juvenile ratio. These combined impacts of host inflammation reversed NFM population growth. Intensity of inflammation was influenced by the genotype of the major histocompatibility complex(MHC), supporting previous research that linked these immunological loci with NFM resistance. Overall, these data provide a model for a mechanism of avian resistance to an ectoparasitic arthropod and

  14. Detection and identification of species-specific bacteria associated with synanthropic mites.

    PubMed

    Hubert, Jan; Kopecký, Jan; Perotti, M Alejandra; Nesvorná, Marta; Braig, Henk R; Ságová-Marečková, Markéta; Macovei, Lilia; Zurek, Ludek

    2012-05-01

    Internal bacterial communities of synanthropic mites Acarus siro, Dermatophagoides farinae, Lepidoglyphus destructor, and Tyrophagus putrescentiae (Acari: Astigmata) were analyzed by culturing and culture-independent approaches from specimens obtained from laboratory colonies. Homogenates of surface-sterilized mites were used for cultivation on non-selective agar and DNA extraction. Isolated bacteria were identified by sequencing of the 16S rRNA gene. PCR amplified 16S rRNA genes were analyzed by terminal restriction fragment length polymorphism analysis (T-RFLP) and cloning sequencing. Fluorescence in situ hybridization using universal bacterial probes was used for direct bacterial localization. T-RFLP analysis of 16S rRNA gene revealed distinct species-specific bacterial communities. The results were further confirmed by cloning and sequencing (284 clones). L. destructor and D. farinae showed more diverse communities then A. siro and T. putrescentiae. In the cultivated part of the community, the mean CFUs from four mite species ranged from 5.2 × 10(2) to 1.4 × 10(3) per mite. D. farinae had significantly higher CFUs than the other species. Bacteria were located in the digestive and reproductive tract, parenchymatical tissue, and in bacteriocytes. Among the clones, Bartonella-like bacteria occurring in A. siro and T. putresecentiae represented a distinct group related to Bartonellaceae and to Bartonella-like symbionts of ants. The clones of high similarity to Xenorhabdus cabanillasii were found in L. destructor and D. farinae, and one clone related to Photorhabdus temperata in A. siro. Members of Sphingobacteriales cloned from D. farinae and A. siro clustered with the sequences of "Candidatus Cardinium hertigii" and as a separate novel cluster.

  15. Scabies mite inactive serine proteases are potent inhibitors of the human complement lectin pathway.

    PubMed

    Reynolds, Simone L; Pike, Robert N; Mika, Angela; Blom, Anna M; Hofmann, Andreas; Wijeyewickrema, Lakshmi C; Kemp, Dave; Fischer, Katja

    2014-05-01

    Scabies is an infectious skin disease caused by the mite Sarcoptes scabiei and has been classified as one of the six most prevalent epidermal parasitic skin diseases infecting populations living in poverty by the World Health Organisation. The role of the complement system, a pivotal component of human innate immunity, as an important defence against invading pathogens has been well documented and many parasites have an arsenal of anti-complement defences. We previously reported on a family of scabies mite proteolytically inactive serine protease paralogues (SMIPP-Ss) thought to be implicated in host defence evasion. We have since shown that two family members, SMIPP-S D1 and I1 have the ability to bind the human complement components C1q, mannose binding lectin (MBL) and properdin and are capable of inhibiting all three human complement pathways. This investigation focused on inhibition of the lectin pathway of complement activation as it is likely to be the primary pathway affecting scabies mites. Activation of the lectin pathway relies on the activation of MBL, and as SMIPP-S D1 and I1 have previously been shown to bind MBL, the nature of this interaction was examined using binding and mutagenesis studies. SMIPP-S D1 bound MBL in complex with MBL-associated serine proteases (MASPs) and released the MASP-2 enzyme from the complex. SMIPP-S I1 was also able to bind MBL in complex with MASPs, but MASP-1 and MASP-2 remained in the complex. Despite these differences in mechanism, both molecules inhibited activation of complement components downstream of MBL. Mutagenesis studies revealed that both SMIPP-Ss used an alternative site of the molecule from the residual active site region to inhibit the lectin pathway. We propose that SMIPP-Ss are potent lectin pathway inhibitors and that this mechanism represents an important tool in the immune evasion repertoire of the parasitic mite and a potential target for therapeutics. PMID:24854034

  16. Benzyl-benzoate foam: effects on mite allergens in mattress, serum and nasal secretory IgE to Dermatophagoides pteronyssinus, and bronchial hyperreactivity in children with allergic asthma.

    PubMed

    Sette, L; Comis, A; Marcucci, F; Sensi, L; Piacentini, G L; Boner, A L

    1994-10-01

    Home mattresses of 24 asthmatic children with house dust mite allergy were sprayed with either benzyl-benzoate foam or placebo in a double blind fashion, 10 days before the children left the residential house for asthmatic children Istituto Pio XII (located in the Italian Alps in an environment free of mites) and went back to their own home for the Christmas and Easter holidays. A further group of 8 children, whose mattresses received no treatment, was kept as an absolute control. Two days after spraying, benzyl-benzoate or placebo were vacuumed from the mattresses. Acarex test was performed immediately before spraying and at the end of each holiday period of 20 and 10 days, respectively. Bronchial hyperreactivity as well as serum and nasal secretory specific IgE for Dermatophagoides pteronyssinus were assessed in all children immediately before leaving and within 48 hr after returning to the residential house. The results of the study show that sprayed benzyl-benzoate foam was no more effective than placebo in reducing the level of house dust mite recovered from patients' mattresses, or in reducing bronchial hyperreactivity and IgE concentration in serum and nasal secretions.

  17. Dust and Planetary Rings

    NASA Astrophysics Data System (ADS)

    Siddiqui, Muddassir

    ABSTRACT Space is not empty it has comic radiations (CMBR), dust etc. Cosmic dust is that type of dust which is composed of particles in space which vary from few molecules to 0.1micro metres in size. This type of dust is made up of heavier atoms born in the heart of stars and supernova. Mainly it contains dust grains and when these dust grains starts compacting then it turns to dense clouds, planetary ring dust and circumstellar dust. Dust grains are mainly silicate particles. Dust plays a major role in our solar system, for example in zodiacal light, Saturn's B ring spokes, planetary rings at Jovian planets and comets. Observations and measurements of cosmic dust in different regions of universe provide an important insight into the Universe's recycling processes. Astronomers consider dust in its most recycled state. Cosmic dust have radiative properties by which they can be detected. Cosmic dusts are classified as intergalactic dusts, interstellar dusts and planetary rings. A planetary ring is a ring of cosmic dust and other small particles orbiting around a planet in flat disc shape. All of the Jovian planets in our solar system have rings. But the most notable one is the Saturn's ring which is the brightest one. In March 2008 a report suggested that the Saturn's moon Rhea may have its own tenuous ring system. The ring swirling around Saturn consists of chunks of ice and dust. Most rings were thought to be unstable and to dissipate over course of tens or hundreds of millions of years but it now appears that Saturn's rings might be older than that. The dust particles in the ring collide with each other and are subjected to forces other than gravity of its own planet. Such collisions and extra forces tend to spread out the rings. Pluto is not known to have any ring system but some Astronomers believe that New Horizons probe might find a ring system when it visits in 2015.It is also predicted that Phobos, a moon of Mars will break up and form into a planetary ring

  18. Pulmonary Toxicity Studies of Lunar Dusts in Rodents

    NASA Technical Reports Server (NTRS)

    Lam, Chiu-wing; James, John T.

    2009-01-01

    NASA will build an outpost on the lunar surface for long-duration human habitation and research. The surface of the Moon is covered by a layer of fine, reactive dust, and the living quarters in the lunar outpost are expected to be contaminated by lunar dust. Because the toxicity of lunar dust is not known, NASA has tasked its toxicology laboratory to evaluate the risk of exposure to the dust and to establish safe exposure limits for astronauts working in the lunar habitat. Studies of the pulmonary toxicity of a dust are generally done first in rodents by intratracheal/intrapharyngeal instillation. This toxicity screening test is then followed by an inhalation study, which requires much more of the test dust and is labor intensive. Preliminary results obtained by examining lung lavage fluid from dust-treated mice show that lunar dust was somewhat toxic (more toxic than TiO2, but less than quartz dust). More extensive studies are in progress to further examine lung lavage fluid for biomarkers of toxicity and lung tissues for histopathological lesions in rodents exposed to aged and activated (ground) lunar dust samples. In these studies, reference dusts (TiO2 and quartz) of known toxicities and have industrial exposure limits will be studied in parallel so the relative toxicity of lunar dust can be determined. The results from the instillation studies will be useful for choosing exposure concentrations for the animal inhalation study. The animal inhalation exposure will be conducted with lunar dust simulant prior to the study with the lunar dust. The experiment with the simulate will ensure that the study techniques used with actual lunar dust will be successful. The results of instillation and inhalation studies will reveal the toxicological risk of exposures and are essential for setting exposure limits on lunar dust for astronauts living in the lunar habitat.

  19. Acaroid mite allergens from the filters of air-conditioning system in China.

    PubMed

    Li, Chao-Pin; Guo, Wei; Zhan, Xiao-Dong; Zhao, Bei-Bei; Diao, Ji-Dong; Li, Na; He, Lian-Ping

    2014-01-01

    Accumulation of acaroid mites in the filters of air-conditioners is harmful to human health. It is important to clarify the allergen components of mites from the filters of local air-conditioning system. The present study was to detect the allergen types in the filters of air-conditioners and assesse their allergenicity by asthmatic models. Sixty aliquots of dust samples were collected from air conditioning filters in civil houses in Wuhu area. Total protein was extracted from the dust samples using PBS and quantified by Bradford method. Allergens I and II were also detected by Western blot using primary antibody (anti-Der f1/2, Der p1/Der f2/Der p2, respectively). Ten aliquots of the positive samples were randomly selected for homogenization and sensitized the mice for developing asthmatic animal models. Total serum IgE level and IFN-γ, IL-4 and IL-5 in the bronchoalveolar lavage fluid (BALF). The allergenicity of the extraction was assessed using pathological sections developed from the mouse pulmonary tissues. The concentration of extract from the 60 samples was ranged from 4.37 μg/ml to 30.76 μg/ml. After analyzing with Western blot, 31 of 60 samples were positive for 4 allergens of acaroid mites, and yet 16 were negative. The levels of total IgE from serum IL-4 and IL-5 from the BALF in the experimental group were apparently higher than that of negative control and PBS group (P < 0.01), but there were no statistical difference compared to OVA group (P > 0.05). However,the IFN-γ level in BALF was lower compared with the negative control and PBS group (P < 0.05) but with the OVA group (P > 0.05). The pathological changes were evidently emerged in pulmonary tissues, which were similar to those of OVA group, compared with the PBS ground and negative controls. The air-conditioner filters in human dwellings of Wuhu area potentially contain the major group allergen 1 and 2 from D. farinae and D. pteronyssinus, which may be associated with seasonal prevalence of

  20. Acaroid mite allergens from the filters of air-conditioning system in China

    PubMed Central

    Li, Chao-Pin; Guo, Wei; Zhan, Xiao-Dong; Zhao, Bei-Bei; Diao, Ji-Dong; Li, Na; He, Lian-Ping

    2014-01-01

    Accumulation of acaroid mites in the filters of air-conditioners is harmful to human health. It is important to clarify the allergen components of mites from the filters of local air-conditioning system. The present study was to detect the allergen types in the filters of air-conditioners and assesse their allergenicity by asthmatic models. Sixty aliquots of dust samples were collected from air conditioning filters in civil houses in Wuhu area. Total protein was extracted from the dust samples using PBS and quantified by Bradford method. Allergens I and II were also detected by Western blot using primary antibody (anti-Der f1/2, Der p1/Der f2/Der p2, respectively). Ten aliquots of the positive samples were randomly selected for homogenization and sensitized the mice for developing asthmatic animal models. Total serum IgE level and IFN-γ, IL-4 and IL-5 in the bronchoalveolar lavage fluid (BALF). The allergenicity of the extraction was assessed using pathological sections developed from the mouse pulmonary tissues. The concentration of extract from the 60 samples was ranged from 4.37 μg/ml to 30.76 μg/ml. After analyzing with Western blot, 31 of 60 samples were positive for 4 allergens of acaroid mites, and yet 16 were negative. The levels of total IgE from serum IL-4 and IL-5 from the BALF in the experimental group were apparently higher than that of negative control and PBS group (P < 0.01), but there were no statistical difference compared to OVA group (P > 0.05). However,the IFN-γ level in BALF was lower compared with the negative control and PBS group (P < 0.05) but with the OVA group (P > 0.05). The pathological changes were evidently emerged in pulmonary tissues, which were similar to those of OVA group, compared with the PBS ground and negative controls. The air-conditioner filters in human dwellings of Wuhu area potentially contain the major group allergen 1 and 2 from D. farinae and D. pteronyssinus, which may be associated with seasonal prevalence of

  1. Acaroid mite allergens from the filters of air-conditioning system in China.

    PubMed

    Li, Chao-Pin; Guo, Wei; Zhan, Xiao-Dong; Zhao, Bei-Bei; Diao, Ji-Dong; Li, Na; He, Lian-Ping

    2014-01-01

    Accumulation of acaroid mites in the filters of air-conditioners is harmful to human health. It is important to clarify the allergen components of mites from the filters of local air-conditioning system. The present study was to detect the allergen types in the filters of air-conditioners and assesse their allergenicity by asthmatic models. Sixty aliquots of dust samples were collected from air conditioning filters in civil houses in Wuhu area. Total protein was extracted from the dust samples using PBS and quantified by Bradford method. Allergens I and II were also detected by Western blot using primary antibody (anti-Der f1/2, Der p1/Der f2/Der p2, respectively). Ten aliquots of the positive samples were randomly selected for homogenization and sensitized the mice for developing asthmatic animal models. Total serum IgE level and IFN-γ, IL-4 and IL-5 in the bronchoalveolar lavage fluid (BALF). The allergenicity of the extraction was assessed using pathological sections developed from the mouse pulmonary tissues. The concentration of extract from the 60 samples was ranged from 4.37 μg/ml to 30.76 μg/ml. After analyzing with Western blot, 31 of 60 samples were positive for 4 allergens of acaroid mites, and yet 16 were negative. The levels of total IgE from serum IL-4 and IL-5 from the BALF in the experimental group were apparently higher than that of negative control and PBS group (P < 0.01), but there were no statistical difference compared to OVA group (P > 0.05). However,the IFN-γ level in BALF was lower compared with the negative control and PBS group (P < 0.05) but with the OVA group (P > 0.05). The pathological changes were evidently emerged in pulmonary tissues, which were similar to those of OVA group, compared with the PBS ground and negative controls. The air-conditioner filters in human dwellings of Wuhu area potentially contain the major group allergen 1 and 2 from D. farinae and D. pteronyssinus, which may be associated with seasonal prevalence of

  2. Feather mites of Calidris fuscicollis (Aves: Scolopacidae) in Brazil.

    PubMed

    Gomes, S N; Pesenti, T C; Cirne, M P; Müller, G

    2015-11-01

    During the period 2010-2012, eighty individuals of Calidris fuscicollis (Vieillot, 1819) were collected on the southern coast of Rio Grande do Sul, Brazil, with the objective of determining the presence of feather mites. Of the 80 birds examined, 32.5% were infested by mites, identified as Avenzoaria calidridis (Oudemans, 1904) (Avenzoariidae) (31.25%), Montchadskiana securicata (Megnin & Trouessart 1884) (Pterolichidae) (22.5%) and Alloptes limosae (Dubinin, 1951) (Alloptidae) (6.25%). This is the first report of feather mites on Calidris fuscicollis in Brazil.

  3. An ant-associated mesostigmatid mite in Baltic amber

    PubMed Central

    Dunlop, Jason A.; Kontschán, Jenő; Walter, David E.; Perrichot, Vincent

    2014-01-01

    Fossil mesostigmatid mites (Acari: Parasitiformes: Mesostigmata) are extremely rare, and specimens from only nine families, including four named species, have been described so far. A new record of Myrmozercon sp. described here from Eocene (ca 44–49 Myr) Baltic amber represents the first—and so far only—fossil example of the derived, extant family Laelapidae. Significantly, modern species of this genus are habitually myrmecophilous and the fossil mite described here is preserved attached to the head of the dolichoderine ant Ctenobethylus goepperti (Mayr, 1868). It thus offers the oldest unequivocal evidence for an ecological association between mesostigmatid mites and social insects in the order Hymenoptera. PMID:25209198

  4. Feather mites of Calidris fuscicollis (Aves: Scolopacidae) in Brazil.

    PubMed

    Gomes, S N; Pesenti, T C; Cirne, M P; Müller, G

    2015-11-01

    During the period 2010-2012, eighty individuals of Calidris fuscicollis (Vieillot, 1819) were collected on the southern coast of Rio Grande do Sul, Brazil, with the objective of determining the presence of feather mites. Of the 80 birds examined, 32.5% were infested by mites, identified as Avenzoaria calidridis (Oudemans, 1904) (Avenzoariidae) (31.25%), Montchadskiana securicata (Megnin & Trouessart 1884) (Pterolichidae) (22.5%) and Alloptes limosae (Dubinin, 1951) (Alloptidae) (6.25%). This is the first report of feather mites on Calidris fuscicollis in Brazil. PMID:26675921

  5. Structure of Phoretic Mite Assemblages Across Subcortical Beetle Species at a Regional Scale.

    PubMed

    Pfammatter, Jesse A; Coyle, David R; Gandhi, Kamal J K; Hernandez, Natalie; Hofstetter, Richard W; Moser, John C; Raffa, Kenneth F

    2016-02-01

    Mites associated with subcortical beetles feed and reproduce within habitats transformed by tree-killing herbivores. Mites lack the ability to independently disperse among these habitats, and thus have evolved characteristics that facilitate using insects as transport between resources. Studies on associations between mites and beetles have historically been beetle-centric, where an assemblage of mite species is characterized on a single beetle species. However, available evidence suggests there may be substantial overlap among mite species on various species of beetles utilizing similar host trees. We assessed the mite communities of multiple beetle species attracted to baited funnel traps in Pinus stands in southern Wisconsin, northern Arizona, and northern Georgia to better characterize mite dispersal and the formation of mite-beetle phoretic associations at multiple scales. We identified approximately 21 mite species totaling 10,575 individuals on 36 beetle species totaling 983 beetles. Of the mites collected, 97% were represented by eight species. Many species of mites were common across beetle species, likely owing to these beetles' common association with trees in the genus Pinus. Most mite species were found on at least three beetle species. Histiostoma spp., Iponemus confusus Lindquist, Histiogaster arborsignis Woodring and Trichouropoda australis Hirschmann were each found on at least seven species of beetles. While beetles had largely similar mite membership, the abundances of individual mite species were highly variable among beetle species within each sampling region. Phoretic mite communities also varied within beetle species between regions, notably for Ips pini (Say) and Ips grandicollis (Eichhoff).

  6. Age and reproductive status of adult Varroa mites affect grooming success of honey bees.

    PubMed

    Kirrane, Maria J; de Guzman, Lilia I; Rinderer, Thomas E; Frake, Amanda M; Wagnitz, Jeremy; Whelan, Pádraig M

    2012-12-01

    This study evaluated for the first time the grooming response of honey bees to Varroa mites of different ages and reproductive statuses in the laboratory. Plastic cages containing a section of dark comb and about 200 bees were inoculated with groups of four classes of mites: gravid, phoretic foundresses, phoretic daughters and a combination of gravid and phoretic foundress mites. Each cage received 20 mites belonging to one of these classes. Our results showed that, 1 day after mite inoculation, phoretic daughter mites were the most prone to grooming by honey bees with an average mite drop of 49.8 ± 2.6 %. The lowest mite drop was recorded for bees inoculated with phoretic foundresses (30.3 ± 3.6 %) but was comparable to bees inoculated with gravid mites (31.8 ± 3.8 %) and the combination of gravid and phoretic foundress mites (34.2 ± 3.2 %). No differences among mite types were detected during the second and third days of observation. Regardless of mite type, the highest mite drop was recorded on the first day (35 ± 2.1 %) compared to the drop for any subsequent day (<10 %). Because of the great reproductive potential of daughter mites, their inclusion in assessments of grooming behaviour may increase our insight into the importance of grooming in mite resistance.

  7. Susceptibilities of northern fowl mite, Ornithonyssus sylviarum (Acarina: Macronyssidae), and chicken mite, Dermanyssus gallinae (Acarina: Dermanyssidae), to selected acaricides.

    PubMed

    Fletcher, M G; Axtell, R C

    1991-12-01

    The relative toxicities of ten acaricides to northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), and the chicken mite, Dermanyssus gallinae (De Geer), were determined simultaneously by holding the mites inside disposable glass Pasteur pipettes previously immersed in acetone solutions of various concentrations (w/v) of technical grade acaricides. The LC90s (parts per million) of the acaricides after 24 h exposure for the northern fowl mite and the chicken mite, respectively, were: bendiocarb (13.1, 0.18), tetrachlorvinphos (14.5, 4.07), carbaryl (15.0, 0.83), pirimiphos methyl (18.3, 2.03), permethrin (23.1, 8.46), lambda cyhalothrin (80.7, 11.4), dichlorvos (252.8, 3.75), malathion (238.4, 6.59), amitraz (6741, 9430) and fenvalerate (greater than 10,000, 60.2). After 48 h exposure there were only slight increases in mortalities of both species except for increased mortalities for the northern fowl mite with lambda cyhalothrin, amitraz and fenvalerate, and for the chicken mite with amitraz. PMID:1786744

  8. Quiescence of Asian dust events in South Korea and Japan during 2012 spring: Dust outbreaks and transports

    NASA Astrophysics Data System (ADS)

    Lee, Yun Gon; Ho, Chang-Hoi; Kim, Joo-Hong; Kim, Jhoon

    2015-08-01

    This study examined the quiescence of Asian dust events in South Korea and Japan during the spring of 2012, presenting a synoptic characterization and suggesting possible causes. Synoptic observation reports from the two countries confirmed that spring 2012 had the lowest number of dust events in 2000-2012. The monthly dust frequency (DF) in March 2012 over the dust source regions, i.e., deserts in northern China and Mongolia, indicated a significant decrease compared to the 12 year (2000-2011) March climatology. The DF in April 2012 was comparable to the 12 year climatology values, but in May 2012 it was slightly lower. The daily Ozone Monitoring Instrument Aerosol Index and the Navy Aerosol Analysis and Prediction System simulations revealed stagnant dust movement in March and May 2012. Anomalous anticyclones north of the source regions decreased the dust outbreaks and enhanced the southeasterly winds, resulting in few dust events over the downwind countries (i.e., South Korea and Japan). By contrast, in April 2012, a strong anomalous cyclone east of Lake Baikal slightly increased the dust outbreaks over northeastern China. However, the major dust outbreaks were not transported downwind because of exceptional dust pathways, i.e., the southeastward pathway of dust transport was unusually blocked by the expansion of an anomalous anticyclonic circulation over the Sea of Okhotsk, with dust being transported northeast.

  9. Observational study of formation mechanism, vertical structure, and dust emission of dust devils over the Taklimakan Desert, China

    NASA Astrophysics Data System (ADS)

    Liu, Chong; Zhao, Tianliang; Yang, Xinghua; Liu, Feng; Han, Yongxiang; Luan, Zhaopeng; He, Qing; Rood, Mark; Yuen, Wangki

    2016-04-01

    A field observation of dust devils was conducted at Xiaotang over the Taklimakan Desert (TD), China, from 7 to 14 July 2014. The measurements of dust devil opacity with the digital optical method and the observed atmospheric boundary layer conditions were applied to investigate the dust devils' formation mechanism, vertical structure, and dust emissions. The critical conditions in the atmospheric boundary layer for dust devil formation were revealed with the land-air surface temperature difference of higher than 15°C, the enhanced momentum flux and sensible heat flux up to 0.54 kg m-1 s-2 and 327 W m-2, respectively, the weak vertical wind shear with the low wind shear index α < 0.10, and the unstable stratification in the lower atmosphere. Based on observed dust opacities, it is identified that a typical dust devil was vertically structured with central updrafts and peripheral downdrafts of dust particles with the asymmetrically horizontal distribution of dust in a rotating dust column. The vertical flux of near-surface dust emissions was also estimated in a range from 5.4 × 10-5 to 9.6 × 10-5 kg m-2 s-1 for a typical dust devil event over TD.

  10. The genome of Tetranychus urticae reveals herbivorous pest adaptations

    PubMed Central

    Grbić, Miodrag; Van Leeuwen, Thomas; Clark, Richard M.; Rombauts, Stephane; Rouzé, Pierre; Grbić, Vojislava; Osborne, Edward J.; Dermauw, Wannes; Ngoc, Phuong Cao Thi; Ortego, Félix; Hernández-Crespo, Pedro; Diaz, Isabel; Martinez, Manuel; Navajas, Maria; Sucena, Élio; Magalhães, Sara; Nagy, Lisa; Pace, Ryan M.; Djuranović, Sergej; Smagghe, Guy; Iga, Masatoshi; Christiaens, Olivier; Veenstra, Jan A.; Ewer, John; Villalobos, Rodrigo Mancilla; Hutter, Jeffrey L.; Hudson, Stephen D.; Velez, Marisela; Yi, Soojin V.; Zeng, Jia; Pires-daSilva, Andre; Roch, Fernando; Cazaux, Marc; Navarro, Marie; Zhurov, Vladimir; Acevedo, Gustavo; Bjelica, Anica; Fawcett, Jeffrey A.; Bonnet, Eric; Martens, Cindy; Baele, Guy; Wissler, Lothar; Sanchez-Rodriguez, Aminael; Tirry, Luc; Blais, Catherine; Demeestere, Kristof; Henz, Stefan R.; Gregory, T. Ryan; Mathieu, Johannes; Verdon, Lou; Farinelli, Laurent; Schmutz, Jeremy; Lindquist, Erika; Feyereisen, René; Van de Peer, Yves

    2016-01-01

    The spider mite Tetranychus urticae is a cosmopolitan agricultural pest with an extensive host plant range and an extreme record of pesticide resistance. Here we present the completely sequenced and annotated spider mite genome, representing the first complete chelicerate genome. At 90 megabases T. urticae has the smallest sequenced arthropod genome. Compared with other arthropods, the spider mite genome shows unique changes in the hormonal environment and organization of the Hox complex, and also reveals evolutionary innovation of silk production. We find strong signatures of polyphagy and detoxification in gene families associated with feeding on different hosts and in new gene families acquired by lateral gene transfer. Deep transcriptome analysis of mites feeding on different plants shows how this pest responds to a changing host environment. The T. urticae genome thus offers new insights into arthropod evolution and plant–herbivore interactions, and provides unique opportunities for developing novel plant protection strategies. PMID:22113690

  11. The genome of Tetranychus urticae reveals herbivorous pest adaptations.

    PubMed

    Grbić, Miodrag; Van Leeuwen, Thomas; Clark, Richard M; Rombauts, Stephane; Rouzé, Pierre; Grbić, Vojislava; Osborne, Edward J; Dermauw, Wannes; Ngoc, Phuong Cao Thi; Ortego, Félix; Hernández-Crespo, Pedro; Diaz, Isabel; Martinez, Manuel; Navajas, Maria; Sucena, Élio; Magalhães, Sara; Nagy, Lisa; Pace, Ryan M; Djuranović, Sergej; Smagghe, Guy; Iga, Masatoshi; Christiaens, Olivier; Veenstra, Jan A; Ewer, John; Villalobos, Rodrigo Mancilla; Hutter, Jeffrey L; Hudson, Stephen D; Velez, Marisela; Yi, Soojin V; Zeng, Jia; Pires-daSilva, Andre; Roch, Fernando; Cazaux, Marc; Navarro, Marie; Zhurov, Vladimir; Acevedo, Gustavo; Bjelica, Anica; Fawcett, Jeffrey A; Bonnet, Eric; Martens, Cindy; Baele, Guy; Wissler, Lothar; Sanchez-Rodriguez, Aminael; Tirry, Luc; Blais, Catherine; Demeestere, Kristof; Henz, Stefan R; Gregory, T Ryan; Mathieu, Johannes; Verdon, Lou; Farinelli, Laurent; Schmutz, Jeremy; Lindquist, Erika; Feyereisen, René; Van de Peer, Yves

    2011-11-23

    The spider mite Tetranychus urticae is a cosmopolitan agricultural pest with an extensive host plant range and an extreme record of pesticide resistance. Here we present the completely sequenced and annotated spider mite genome, representing the first complete chelicerate genome. At 90 megabases T. urticae has the smallest sequenced arthropod genome. Compared with other arthropods, the spider mite genome shows unique changes in the hormonal environment and organization of the Hox complex, and also reveals evolutionary innovation of silk production. We find strong signatures of polyphagy and detoxification in gene families associated with feeding on different hosts and in new gene families acquired by lateral gene transfer. Deep transcriptome analysis of mites feeding on different plants shows how this pest responds to a changing host environment. The T. urticae genome thus offers new insights into arthropod evolution and plant-herbivore interactions, and provides unique opportunities for developing novel plant protection strategies.

  12. Exozodiacal Dust and Direct Imaging of Extrasolar Planets

    NASA Technical Reports Server (NTRS)

    Kuchner, Marc

    2008-01-01

    Direct imaging of extrasolar planets means contending with dust from extrasolar asteroids and comets. This 'exozodiacal dust' creates a structured background light that can easily outshine the light from an exoEarth and confuse a planet-search mission like TPF or TOPS. But exozodiacal dust can be both friend and foe: planets can stir dust clouds into patterns that reveal the presence of the planet and constrain its mass and orbit. I'll describe some recent research on this topic: 3-D dynamical models of dust clouds with planets and searches for exozodiacal dust with the Keck Interferometer. The author also offers a prediction for the typical zodiacal dust background found around solar analogs, based on seafloor sediment data.

  13. Identification of developmentally-specific kinotypes and mechanisms of Varroa mite resistance through whole-organism, kinome analysis of honeybee

    PubMed Central

    Robertson, Albert J.; Trost, Brett; Scruten, Erin; Robertson, Thomas; Mostajeran, Mohammad; Connor, Wayne; Kusalik, Anthony; Griebel, Philip; Napper, Scott

    2014-01-01

    Recent investigations associate Varroa destructor (Mesostigmata: Varroidae) parasitism and its associated pathogens and agricultural pesticides with negative effects on colony health, resulting in sporadic global declines in domestic honeybee (Apis mellifera) populations. These events have motivated efforts to develop research tools that can offer insight into the causes of declining bee health as well as identify biomarkers to guide breeding programs. Here we report the development of a bee-specific peptide array for characterizing global cellular kinase activity in whole bee extracts. The arrays reveal distinct, developmentally-specific signaling profiles between bees with differential susceptibility to infestation by Varroa mites. Gene ontology analysis of the differentially phosphorylated peptides indicates that the differential susceptibility to Varroa mite infestation does not reflect compromised immunity; rather, there is evidence for mite-mediated immune suppression within the susceptible phenotype that may reduce the ability of these bees to counter secondary viral infections. This hypothesis is supported by the demonstration of more diverse viral infections in mite-infested, susceptible adult bees. The bee-specific peptide arrays are an effective tool for understanding the molecular basis of this complex phenotype as well as for the discovery and utilization of phosphorylation biomarkers for breeding programs. PMID:24904639

  14. Ultrastructure investigation of the secondary insemination system of the gamasid mite Hattena cometis domrow (Acari: Anactinotrichida: Ameroseiidae).

    PubMed

    Di Palma, Antonella; Seeman, Owen; Alberti, Gerd

    2013-08-01

    Many gamasid mites, mainly of the taxon Dermanyssina, possess a secondarily evolved insemination system that is generally described as occurring in two types, the laelapid and the phytoseiid-type, which are structurally considerably different. Considering that Dermanyssina represent the most recent and most diverse group of gamasid mites, it was expected that a greater diversity of insemination system than reflected by the two types could be present and could give an idea of its evolution within the taxon. Here, the authors present a description of the fine-structure of the female secondary insemination system in the dermanyssine mite Hattena cometis. The system consists of a pair of sperm induction pores (solenostomes) and short sperm access ducts (tubules) which end in a syncytium. The syncytial strands of both sides meet medially under the ovary s.str., where they form a spherical syncytial spermatheca. Mature sperm cells of a modified ribbon type were seen in the syncytial parts of the system. The insemination system of Hattena cometis is regarded as a modification of the laelapid type. However, it is much simpler than that of Varroa destructor, the only other gamasid mite with the laelapid type studied ultrastructurally until now, and shows also some structural differences (e.g., no presence of an unpaired sperm duct). Hence, the present study suggests that some intermediate types might be revealed in future ultrastructure studies representing steps in the evolution of the insemination system in the Dermanyssina.

  15. In vitro and in vivo inhibition of alpha-amylases of stored-product mite Acarus siro.

    PubMed

    Hubert, Jan; Dolecková-Maresová, Lucie; Hýblová, Jana; Kudlíková, Iva; Stejskal, Václav; Mares, Michael

    2005-01-01

    The stored-product mites are the most abundant and frequent group of pests living on the stored food products in Europe. They endanger public health since they produce allergens and transmit mycotoxin-producing fungi. Novel acaricidal compounds with inhibitory effects on the digestive enzymes of arthropods are a safe alternative to the traditional neurotoxic pesticides used for control of the stored-product pests. In this work, we explored the properties of acarbose, the low molecular weight inhibitor of alpha-amylases (AI), as a novel acaricide candidate for protection of the stored products from infestation by Acarus siro (Acari: Acaridae). In vitro analysis revealed that AI blocked efficiently the enzymatic activity of digestive amylases of A. siro, and decreased the physiological capacity of mite's gut in utilizing a starch component of grain flour. In vivo experiments showed that AI suppressed the population growth of A. siro. The mites were kept for three weeks on experimental diet enriched by AI in concentration range of 0.005 to 0.25%. Population growth of A. siro was negatively correlated with the content of AI in the treated diet with a half-population dose of 0.125%. The suppressive effect of AIs on stored-product mites is discussed in the context of their potential application in GMO crops. PMID:15969461

  16. In vitro and in vivo inhibition of alpha-amylases of stored-product mite Acarus siro.

    PubMed

    Hubert, Jan; Dolecková-Maresová, Lucie; Hýblová, Jana; Kudlíková, Iva; Stejskal, Václav; Mares, Michael

    2005-01-01

    The stored-product mites are the most abundant and frequent group of pests living on the stored food products in Europe. They endanger public health since they produce allergens and transmit mycotoxin-producing fungi. Novel acaricidal compounds with inhibitory effects on the digestive enzymes of arthropods are a safe alternative to the traditional neurotoxic pesticides used for control of the stored-product pests. In this work, we explored the properties of acarbose, the low molecular weight inhibitor of alpha-amylases (AI), as a novel acaricide candidate for protection of the stored products from infestation by Acarus siro (Acari: Acaridae). In vitro analysis revealed that AI blocked efficiently the enzymatic activity of digestive amylases of A. siro, and decreased the physiological capacity of mite's gut in utilizing a starch component of grain flour. In vivo experiments showed that AI suppressed the population growth of A. siro. The mites were kept for three weeks on experimental diet enriched by AI in concentration range of 0.005 to 0.25%. Population growth of A. siro was negatively correlated with the content of AI in the treated diet with a half-population dose of 0.125%. The suppressive effect of AIs on stored-product mites is discussed in the context of their potential application in GMO crops.

  17. Pathogenic role of Demodex mites in blepharitis

    PubMed Central

    Liu, Jingbo; Sheha, Hosam; Tseng, Scheffer C.G.

    2010-01-01

    Purpose of review To summarize the key literature and our research experience regarding Demodex infestation as a potential cause of ocular inflammatory diseases with a special emphasis on Demodex blepharitis. Recent findings Two distinct Demodex species have been confirmed as a cause of blepharitis: Demodex folliculorum can cause anterior blepharitis associated with disorders of eyelashes, and D. brevis can cause posterior blepharitis with meibomian gland dysfunction and keratoconjunctivitis. Tea tree oil treatments with either 50% lid scrubs or 5% lid massages are effective in eradicating mites and reducing ocular surface inflammation. Summary Demodex blepharitis is a common but overlooked external eye disease. The pathogenesis of Demodex blepharitis in eliciting ocular surface inflammation has been further clarified. The modified eyelash sampling and counting method makes it easier and more accurate to diagnose Demodex infestation. Tea tree oil shows promising potential to treat Demodex blepharitis by reducing Demodex counts with additional antibacterial, antifungal, and anti-inflammatory actions. PMID:20689407

  18. Impeding movement of the poultry red mite, Dermanyssus gallinae.

    PubMed

    Pritchard, James; Küster, Tatiana; George, David; Sparagano, Olivier; Tomley, Fiona

    2016-07-30

    The poultry red mite, Dermanyssus gallinae, is an economically important hematophagous parasite of commercial egg laying hens, also affecting domesticated birds and companion animals. Conventional control of D. gallinae through acaricidal spraying is often ineffective, creating an urgent need to identify alternative management strategies for commercial and domestic infestations. Whilst integrated pest management is being considered for D. gallinae, the potential of impeding mite 'migration' routes, to either prevent initial infestation or manage established populations, has not been researched. Here we demonstrate that barriers of insecticidal glue, double sided sticky tape and thyme oil can contain D. gallinae within a specified area of a petri dish (78-88% of total mite population) and this level of containment was significantly greater than for negative controls (p values <0.05). Further studies in poultry houses are recommended to investigate the efficacy of these barriers in real world application and identity potential for barriers as a strategy for mite control. PMID:27369583

  19. Feather mites of the greater sandhill crane (Grus canadensis tabida)

    USGS Publications Warehouse

    Atyeo, W.T.; Windingstad, Ronald M.

    1979-01-01

    New taxa are described from Grus canadensis tabida: Brephosceles petersoni sp. n. (Alloptidae); Pseudogabucinia reticulata sp. n. (Kramerellidae); Geranolichus canadensis sp. n., and Gruolichus wodashae, gen. et sp. n. (Pterolichidae). Observations on resource partitioning by these mites are given.

  20. Impeding movement of the poultry red mite, Dermanyssus gallinae.

    PubMed

    Pritchard, James; Küster, Tatiana; George, David; Sparagano, Olivier; Tomley, Fiona

    2016-07-30

    The poultry red mite, Dermanyssus gallinae, is an economically important hematophagous parasite of commercial egg laying hens, also affecting domesticated birds and companion animals. Conventional control of D. gallinae through acaricidal spraying is often ineffective, creating an urgent need to identify alternative management strategies for commercial and domestic infestations. Whilst integrated pest management is being considered for D. gallinae, the potential of impeding mite 'migration' routes, to either prevent initial infestation or manage established populations, has not been researched. Here we demonstrate that barriers of insecticidal glue, double sided sticky tape and thyme oil can contain D. gallinae within a specified area of a petri dish (78-88% of total mite population) and this level of containment was significantly greater than for negative controls (p values <0.05). Further studies in poultry houses are recommended to investigate the efficacy of these barriers in real world application and identity potential for barriers as a strategy for mite control.

  1. Photoluminescence by Interstellar Dust

    NASA Astrophysics Data System (ADS)

    Vijh, U. P.

    2005-08-01

    In this dissertation, we report on our study of interstellar dust through the process of photoluminescence (PL). We present the discovery of a new band of dust PL, blue luminescence (BL) with λpeak˜370 nm in the proto-planetary nebula known as the Red Rectangle (RR). We attribute this to fluorescence by small, 3-4-ringed polycyclic aromatic hydrocarbon (PAH) molecules. Further analysis reveals additional independent evidence for the presence of small PAHs in this nebula. Detection of BL using long-slit spectroscopic observations in other ordinary reflection nebulae suggests that the BL carrier is an ubiquitous component of the ISM and is not restricted to the particular environment of the RR. We present the spatial distribution of the BL in these nebulae and find that the BL is spatially correlated with IR emission structures attributed to aromatic emission features (AEFs), attributed to PAHs. The carrier of the dust-associated photoluminescence process causing the extended red emission (ERE), known now for over twenty five years, remains unidentified. We constrain the character of the ERE carrier by determining the wavelengths of the radiation that initiates the ERE -- λ < 118 nm. We note that under interstellar conditions most PAH molecules are ionized to the di-cation stage by photons with E > 10.5 eV and that the electronic energy level structure of PAH di-cations is consistent with fluorescence in the wavelength band of the ERE. In the last few chapters of the dissertation we present first results from ongoing work: i) Using narrow-band imaging, we present the optical detection of the circum-binary disk of the RR in the light of the BL, and show that the morphology of the BL and ERE emissions in the RR nebula are almost mutually exclusive. It is very suggestive to attribute them to different ionization stages of the same family of carriers such as PAH molecules. ii) We also present a pure spectrum of the BL free of scattered light, resolved into seven

  2. Low dust charging rate induced weakly dissipative dust acoustic solitary waves: Role of nonthermal ions

    SciTech Connect

    Chaudhuri, Tushar Kanti; Khan, Manoranjan; Gupta, M. R.; Ghosh, Samiran

    2007-10-15

    The effects of low dust charging rate compared to the dust oscillation frequency and nonthermal ions on small but finite amplitude nonlinear dust acoustic wave have been investigated. It is seen that because of the low dust charging rate, the nonlinear wave exhibits weakly dissipative solitary wave that is governed by a modified form of the Korteweg-de Vries equation. The solitary wave possesses both rarefactive and compressive soliton solution depending on the values of ion nonthermality parameter a. An analytical solution reveals that because of the simultaneous effects of low dust charging rate and nonthermal ions, the wave amplitude may grow exponentially with time if the ion nonthermality parameter (a) exceeds a critical value provided the ion-electron temperature ratio ({sigma}{sub i}) is less than 0.11.

  3. Wetting Behavior of Hydrophobic Dust and Dust-Fall Theory of Fine Droplets

    NASA Astrophysics Data System (ADS)

    Kou, Bao-Fu; Liu, Qiu-Zu

    2015-12-01

    The wetting behavior of droplets on the surfaces of hydrophobic coal slices is measured with a CCD camera and simulated with the volume of fluid (VOF) numerical method. Experimental results reveal that the contact angle changes exponatially with time and the wettability decreases with the increasing rough microstructures of coal slice surfaces. There is a good agreement between numerical simulations and experimental results. Meanwhile, it is found that droplet with a smaller volume can enhance the hydrophilic. The dust-fall theory of fine droplets is useful to improve the wettability of dust and enlarge the contact ratio between dust and droplets, which can help to design wet-type dust-fall equipment and provide new way for the control of respiratory dust.

  4. Haul road dust control

    SciTech Connect

    Reed, W.R.; Organiscak, J.A.

    2007-10-15

    A field study was conducted to measure dust from haul trucks at a limestone quarry and a coal preparation plant waste hauling operation. The study found that primarily wind, distance and road treatment conditions notably affected the dust concentrations at locations next to, 50 ft from, and 100 ft away from the unpaved haulage road. Airborne dust measured along the unpaved haul road showed that high concentrations of fugitive dust can be generated with these concentrations rapidly decreasing to nearly background levels within 100 ft of the road. Instantaneous respirable dust measurements illustrated that the trucks generate a real-time dust cloud that has a peak concentration with a time-related decay rate as the dust moves past the sampling locations. The respirable dust concentrations and peak levels were notably diminished as the dust cloud was transported, diluted, and diffused by the wind over the 100 ft distance from the road. Individual truck concentrations and peak levels measured next to the dry road surface test section were quite variable and dependent on wind conditions, particularly wind direction, with respect to reaching the sampling location. The vast majority of the fugitive airborne dust generated from unpaved and untreated haulage roads was non-respirable. 6 figs.

  5. Dust Emission from Stephan's Quintet

    NASA Astrophysics Data System (ADS)

    Natale, G.; Tuffs, R.; Popescu, C.; Xu, C. K.; Fischera, J.; Lu, N.; Appleton, P.; Dopita, M.; Sulentic, J.; Gao, Y.; Yun, M.; Reach, W.; Boulanger, F.; Ogle, P.; Duc, P. A.; Des Forets, G. P.

    2010-10-01

    We present new infrared images of the prototype of compact galaxy groups, Stephan’s Quintet, taken with Spitzer/MIPS at 24, 70 and 160μm, and compare these with existing images at X-ray (Trinchieri et al. 2005, ,hereafter T05), UV/optical (Xu et al. 2005) and radio wavelengths (Williams et al. 2002) as well as with archival Spitzer/IRAC imaging at 8μ m. Morphological decomposition of the new images reveal an extended (on scales of up to 70 kpc) component of FIR emission which is roughly correlated with diffuse soft X-ray emission arising from the SHOCK and HALO regions (see T05). This correlation could be due, in principle, to collisional heating of dust embedded in X-ray plasma. If active, this mechanism would determine a significant shortening of the gas cooling time scale because the luminosity of the X-ray correlated infrared emission is about 70 times higher than the X-ray luminosity. However the color of dust emission and the inferred dust to gas ratio, comparable to the solar neighbourhood value, are difficult to explain in terms of purely collisionally heated dust. It is plausible that dust in colder and denser gas phases, heated by the diffuse intergalactic radiation field and/or local radiation fields from embedded young stars, is the major source of the apparently extended emission. The presence of the extended infrared emission, not related to the main bodies of the galaxies, is probably a direct consequence of the interaction induced decoupling between gas and stars in Stephan’s Quintet. Gas displacement has also modified the location of star formation sites (as traced by compact sources in the Spitzer images and the UV) compared to the case of isolated galaxies. In Stephan’s Quintet most of the recent star formation appears to have occurred at the peripheries of the galaxies, extending into the intergalactic medium.

  6. Autumn invasion rates of Varroa destructor (Mesostigmata: Varroidae) into honey bee (Hymenoptera: Apidae) colonies and the resulting increase in mite populations.

    PubMed

    Frey, Eva; Rosenkranz, Peter

    2014-04-01

    The honey bee parasite Varroa destructor Anderson & Trueman can disperse and invade honey bee colonies by attaching to "drifting" and "robbing" honey bees that move into nonnatal colonies. We quantified the weekly invasion rates and the subsequent mite population growth from the end of July to November 2011 in 28 honey bee colonies kept in two apiaries that had high (HBD) and low (LBD) densities of neighboring colonies. At each apiary, half (seven) of the colonies were continuously treated with acaricides to kill all Varroa mites and thereby determine the invasion rates. The other group of colonies was only treated before the beginning of the experiment and then left untreated to record Varroa population growth until a final treatment in November. The numbers of bees and brood cells of all colonies were estimated according to the Liebefeld evaluation method. The invasion rates varied among individual colonies but revealed highly significant differences between the study sites. The average invasion rate per colony over the entire 3.5-mo period ranged from 266 to 1,171 mites at the HBD site compared with only 72 to 248 mites at the LBD apiary. In the untreated colonies, the Varroa population reached an average final infestation in November of 2,082 mites per colony (HBD) and 340 mites per colony (LBD). All colonies survived the winter; however, the higher infested colonies lost about three times more bees compared with the lower infested colonies. Therefore, mite invasion and late-year population growth must be considered more carefully for future treatment concepts in temperate regions.

  7. Mite infestations of man contracted from dogs and cats.

    PubMed

    Thomsett, L R

    1968-07-13

    Acarine infestations of the dog and cat are transmissible to man. The relation between age incidence in the host, duration of disease, and circumstances under which the animal is kept are stated. Fifty out of 65 human contacts at risk to 42 infected dogs and cats showed lesions of mite infestation; 48% of these lesions were confined to the arms and torso.It is important to consider animal mite infestation in the differential diagnosis of human pruritic and papular skin disease.

  8. Pulmonary Toxicity Studies of Lunar Dusts in Rodents

    NASA Technical Reports Server (NTRS)

    Lam, Chiu-wing; James, John T.; Taylor, Larry

    2008-01-01

    useful for choosing an exposure concentration for the animal inhalation study on a selected lunar dust sample, which is included as a part of this proposal. The animal inhalation exposure will be conducted with lunar dust simulant prior to the study with the lunar dust. The simulant exposure will ensure that the study techniques used with actual lunar dust will be successful. The results of ITI and inhalation studies will reveal the toxicological risk of exposures and are essential for setting exposure limits on lunar dust for astronauts living in the lunar habitat.

  9. Techniques for identifying dust devils in mars pathfinder images

    USGS Publications Warehouse

    Metzger, S.M.; Carr, J.R.; Johnson, J. R.; Parker, T.J.; Lemmon, M.T.

    2000-01-01

    Image processing methods used to identify and enhance dust devil features imaged by IMP (Imager for Mars Pathfinder) are reviewed. Spectral differences, visible red minus visible blue, were used for initial dust devil searches, driven by the observation that Martian dust has high red and low blue reflectance. The Martian sky proved to be more heavily dust-laden than pre-Pathfinder predictions, based on analysis of images from the Hubble Space Telescope. As a result, these initial spectral difference methods failed to contrast dust devils with background dust haze. Imager artifacts (dust motes on the camera lens, flat-field effects caused by imperfections in the CCD, and projection onto a flat sensor plane by a convex lens) further impeded the ability to resolve subtle dust devil features. Consequently, reference images containing sky with a minimal horizon were first subtracted from each spectral filter image to remove camera artifacts and reduce the background dust haze signal. Once the sky-flat preprocessing step was completed, the red-minus-blue spectral difference scheme was attempted again. Dust devils then were successfully identified as bright plumes. False-color ratios using calibrated IMP images were found useful for visualizing dust plumes, verifying initial discoveries as vortex-like features. Enhancement of monochromatic (especially blue filter) images revealed dust devils as silhouettes against brighter background sky. Experiments with principal components transformation identified dust devils in raw, uncalibrated IMP images and further showed relative movement of dust devils across the Martian surface. A variety of methods therefore served qualitative and quantitative goals for dust plume identification and analysis in an environment where such features are obscure.

  10. Integrated pest management of two-spotted mite Tetranychus urticae on greenhouse roses using petroleum spray oil and the predatory mite Phytoseiulus persimilis.

    PubMed

    Nicetic; Watson, D M; Beattie, G A; Meats, A; Zheng, J

    2001-01-01

    From 1995 to 1999, four experiments were conducted on greenhouse roses to assess the effectiveness of the nC24 petroleum spray oil (PSO), D-C-Tron Plus, against two-spotted mite, Tetranychus urticae Koch (Acarina: Tetranychidae), and to determine how the oil could be most efficiently and effectively used in combination with the predatory mite Phytoseiulus persimilis Athias-Henriot (Acarina: Phytoseiidae) in an integrated pest management program. The results showed that 0.5% PSO applied fortnightly to roses gave excellent protection from T urticae infestation when the mite population was not already established. However, PSO applied after roses were infested with T. urticae above the economic threshold only stabilised populations without reducing them below that threshold. Populations of P. persimilis in the upper and lower canopies were unchanged after two sprays of PSO at 7-day intervals, and application of PSO to the upper canopy was as effective in controlling T. urticae in the presence of P persimilis as spraying the entire plant. Combining PSO with P. persimilis gave better control of T. urticae than using P. persimilis alone. The most cost-effective use of PSO in the presence of P. persimilis is, therefore, to apply spray only to the upper canopy. This will not affect control of powdery mildew with PSO. Comparison of a control program for T urticae based on the monitored use of synthetic miticides with that based on calendar application of PSO revealed that both gave equally effective control. The benefits of combining PSO and P. persimilis in an integrated pest management program for T. urticae on roses over a program based on synthetic fungicides are discussed.

  11. New Wolbachia supergroups detected in quill mites (Acari: Syringophilidae).

    PubMed

    Glowska, Eliza; Dragun-Damian, Anna; Dabert, Miroslawa; Gerth, Michael

    2015-03-01

    Wolbachia is the most abundant intracellular bacterial genus infecting a wide range of arthropods and filarial nematodes. Wolbachia have evolved parasitic, mutualistic and commensal relationships with their hosts but in arthropods generally act as reproductive parasites, inducing a wide range of phenotypic effects such as cytoplasmic incompatibility, parthenogenesis, feminization and male-killing. Up to now, the genus has been divided into 14 supergroups successively named A-O. Here, we describe two new Wolbachia supergroups from syringophilid mites (Acari: Cheyletoidea). These obligatory ectoparasites of birds inhabit the quills of feathers in many avian groups. The species of this family reproduce in a haplodiploid mode sensu arrhenotoky and are usually strongly female-biased. Based on the sequences of four protein-coding genes (ftsZ, gltA and groEL and coxA) and the 16S rRNA we identified strains of three Wolbachia supergroups (F and two distinct, yet undescribed ones) in five quill mite species. Our results suggest that in some cases the distribution of the bacteria can be better correlated with the mite's bird host rather than with mite taxonomy as such. The discovery of two new Wolbachia supergroups not only broadens the knowledge of the diversity of this bacterium but also raises questions about potential effects induced in quill mites and transmission mechanisms of the endosymbionts in this peculiar bacteria-quill mite-bird system.

  12. Spider mite web mediates anti-predator behaviour.

    PubMed

    Lemos, Felipe; Sarmento, Renato Almeida; Pallini, Angelo; Dias, Cleide Rosa; Sabelis, Maurice W; Janssen, Arne

    2010-09-01

    Herbivores suffer significant mortality from predation and are therefore subject to natural selection on traits promoting predator avoidance and resistance. They can employ an array of strategies to reduce predation, for example through changes in behaviour, morphology and life history. So far, the anti-predator response studied most intensively in spider mites has been the avoidance of patches with high predation risk. Less attention has been given to the dense web produced by spider mites, which is a complex structure of silken threads that is thought to hinder predators. Here, we investigate the effects of the web produced by the red spider mite, Tetranychus evansi Baker & Pritchard, on its interactions with the predatory mite, Phytoseiulus longipes Evans. We tested whether female spider mites recognize predator cues and whether these can induce the spider mites to produce denser web. We found that the prey did not produce denser web in response to such cues, but laid more eggs suspended in the web, away from the leaf surface. These suspended eggs suffered less from predation by P. longipes than eggs that were laid on the leaf surface under the web. Thus, by altering their oviposition behaviour in response to predator cues, females of T. evansi protect their offspring.

  13. Experimental infection of dogs with the nasal mite Pneumonyssoides caninum.

    PubMed

    Gunnarsson, L; Zakrisson, G; Lilliehook, I; Christensson, D; Rehbinder, C; Uggla, A

    1998-06-15

    A successful experimental transmission of the canine nasal mite, Pneumonyssoides caninum, is described. Some 11 weeks after repeated systemic ivermectin treatment, four Beagles were inoculated via the right nostril with 20 P. caninum mites of different sexes and life stages, obtained at the necropsy of an infected dog. The inoculated dogs and a matching uninoculated control were observed for clinical signs for 14 weeks and then euthanised. Vague upper respiratory signs and a transient minor increase in the number of eosinophils in peripheral blood were recorded in the inoculated dogs. At necropsy 4-12 P. caninum mites were found in the nasal cavities and sinuses of the inoculated dogs, but none in the control. In three out of the four infected dogs mites were found in both the right and left nasal cavities and sinuses of the skull. Since in no case more mites than the number used for inoculation were detected it is not clear if the mites managed to reproduce in the dogs. Inflammatory lesions were seen most consistently in the olfactory mucosa, respiratory mucosa and tonsils, and growth of opportunistic bacteria was observed in the tonsils of the infected dogs. The inflammatory lesions seen in the olfactory mucosa may explain why dogs infected with P. caninum sometimes appear to suffer from impaired scenting ability.

  14. DUST FORMATION IN MACRONOVAE

    SciTech Connect

    Takami, Hajime; Ioka, Kunihito; Nozawa, Takaya E-mail: kunihito.ioka@kek.jp

    2014-07-01

    We examine dust formation in macronovae (as known as kilonovae), which are the bright ejecta of neutron star binary mergers and one of the leading sites of r-process nucleosynthesis. In light of information about the first macronova candidate associated with GRB 130603B, we find that dust grains of r-process elements have difficulty forming because of the low number density of the r-process atoms, while carbon or elements lighter than iron can condense into dust if they are abundant. Dust grains absorb emission from ejecta with an opacity even greater than that of the r-process elements, and re-emit photons at infrared wavelengths. Such dust emission can potentially account for macronovae without r-process nucleosynthesis as an alternative model. This dust scenario predicts a spectrum with fewer features than the r-process model and day-scale optical-to-ultraviolet emission.

  15. Interstellar Dust Models

    NASA Technical Reports Server (NTRS)

    Dwek, Eli

    2004-01-01

    A viable interstellar dust model - characterized by the composition, morphology, and size distribution of the dust grains and by the abundance of the different elements locked up in the dust - should fit all observational constraints arising primarily from the interactions of the dust with incident radiation or the ambient gas. As a minimum, these should include the average interstellar extinction, the infrared emission from the diffuse interstellar medium (ISM), and the observed interstellar abundances of the various refractory elements. The last constraint has been largely ignored, resulting in dust models that require more elements to be in the dust phase than available in the ISM. In this talk I will describe the most recent advances towards the construction of a comprehensive dust model made by Zubko, Dwek, and Arendt, who, for the first time, included the interstellar abundances as explicit constraints in the construction of interstellar dust models. The results showed the existence of many distinct models that satisfy the basic set of observational constraints, including bare spherical silicate and graphite particles, PAHs, as well as spherical composite particles containing silicate, organic refractories, water ice, and voids. Recently, a new interstellar dust constituent has emerged, consisting of metallic needles. These needles constitute a very small fraction of the interstellar dust abundance, and their existence is primarily manifested in the 4 to 8 micron wavelength region, where they dominate the interstellar extinction. Preliminary studies show that these models may be distinguished by their X-ray halos, which are produced primarily by small angle scattering off large dust particles along the line of sight to bright X-ray sources, and probe dust properties largely inaccessible at other wavelengths.

  16. Smells familiar: group-joining decisions of predatory mites are mediated by olfactory cues of social familiarity.

    PubMed

    Muleta, Muluken G; Schausberger, Peter

    2013-09-01

    Group-living animals frequently have to trade off the costs and benefits of leaving an established group and joining another group. Owing to their high fitness relevance, group-joining decisions are commonly nonrandom and may be based on traits of both individual members and the group such as life stage, body size, social status and group density or size, respectively. Many group-living animals are able to recognize and to associate preferentially with familiar individuals, i.e. those encountered before. Hence, after dispersing from established groups, animals commonly have to decide whether to join a new familiar or unfamiliar group. Using binary choice situations we assessed the effects of social familiarity on group-joining behaviour of the plant-inhabiting predatory mite Phytoseiulus persimilis. Group living in P. persimilis is brought about by the patchy distribution of its spider mite prey and mutual conspecific attraction. In the first experiment, gravid predator females given a choice between spider mite patches occupied by unfamiliar and familiar groups of females strongly preferred to join familiar groups and to deposit their eggs in these patches. Preference for socially familiar groups was robust across biases of spider mite prey densities between choice options. The second experiment revealed that the predatory mite females can smell social familiarity from a distance. Females subjected to odour choice situations in artificial cages were more strongly attracted to the odour of familiar than unfamiliar groups. We argue that P. persimilis females preferentially join socially familiar groups because a familiar social environment relaxes competition and optimizes foraging and reproduction. PMID:24027341

  17. Operational Dust Prediction

    NASA Technical Reports Server (NTRS)

    Benedetti, Angela; Baldasano, Jose M.; Basart, Sara; Benincasa, Francesco; Boucher, Olivier; Brooks, Malcolm E.; Chen, Jen-Ping; Colarco, Peter R.; Gong, Sunlin; Huneeus, Nicolas; Jones, Luke; Lu, Sarah; Menut, Laurent; Morcrette, Jean-Jacques; Mulcahy, Jane; Nickovic, Slobodan; Garcia-Pando, Carlos P.; Reid, Jeffrey S.; Sekiyama, Thomas T.; Tanaka, Taichu Y.; Terradellas, Enric; Westphal, Douglas L.; Zhang, Xiao-Ye; Zhou, Chun-Hong

    2014-01-01

    Over the last few years, numerical prediction of dust aerosol concentration has become prominent at several research and operational weather centres due to growing interest from diverse stakeholders, such as solar energy plant managers, health professionals, aviation and military authorities and policymakers. Dust prediction in numerical weather prediction-type models faces a number of challenges owing to the complexity of the system. At the centre of the problem is the vast range of scales required to fully account for all of the physical processes related to dust. Another limiting factor is the paucity of suitable dust observations available for model, evaluation and assimilation. This chapter discusses in detail numerical prediction of dust with examples from systems that are currently providing dust forecasts in near real-time or are part of international efforts to establish daily provision of dust forecasts based on multi-model ensembles. The various models are introduced and described along with an overview on the importance of dust prediction activities and a historical perspective. Assimilation and evaluation aspects in dust prediction are also discussed.

  18. Dust Devil Tracks

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 8 May 2002) The Science This image, centered near 50.0 S and 17.7 W displays dust devil tracks on the surface. Most of the lighter portions of the image likely have a thin veneer of dust settled on the surface. As a dust devil passes over the surface, it acts as a vacuum and picks up the dust, leaving the darker substrate exposed. In this image there is a general trend of many of the tracks running from east to west or west to east, indicating the general wind direction. There is often no general trend present in dust devil tracks seen in other images. The track patterns are quite ephemeral and can completely change or even disappear over the course of a few months. Dust devils are one of the mechanisms that Mars uses to constantly pump dust into the ubiquitously dusty atmosphere. This atmospheric dust is one of the main driving forces of the present Martian climate. The Story Vrrrrooooooooom. Think of a tornado, the cartoon Tasmanian devil, or any number of vacuum commercials that powerfully suck up swirls of dust and dirt. That's pretty much what it's like on the surface of Mars a lot of the time. Whirlpools of wind called

  19. Temperature of cometary dust

    NASA Astrophysics Data System (ADS)

    Henning, Th.; Weidlich, U.

    1988-05-01

    The variation of dust temperature with heliocentric distance for a comet is calculated using the optical constants of an astronomically important silicate. The silicate, described by Drane (1985), is assumed to be similar to cometary dust. The temperatures of cometary dust grains are determined by the energy balance between the absorbed sunlight and emitted thermal radiation, and equilibrium temperatures of dust grains for different radii and heliocentric distances are compared. Deviations between computed and observed temperatures are attributed to variations in the chemical composition of the ablated grains.

  20. Identification of bacterial species associated with the sheep scab mite (Psoroptes ovis) by using amplified genes coding for 16S rRNA.

    PubMed

    Hogg, J C; Lehane, M J

    1999-09-01

    This was the first molecular study of the bacterial flora of the sheep scab mite (Psoroptes ovis). A sequence analysis of genes coding for 16S rRNA revealed that Serratia marcescens and bacteria closely related to Staphylococcus intermedius or Staphylococcus chromogens and Alloiococcus otitidis were present. These bacteria were associated with skin lesions, dermatitis, and otitis media caused by P. ovis.

  1. Quasar Dust Factories.

    NASA Astrophysics Data System (ADS)

    Marengo, Massimo; Elvis, Martin; Karovska, Margarita

    We show that quasars are naturally copious producers of dust, assuming only that the quasar broad emission lines (BELs) are produced by gas clouds that are part of an outflowing wind. These BEL clouds have large initial densities (ne ˜109 - 1011 cm-3) so that as they expand quasi-adiabatically they cool from an initial T = 104 K to a dust-capable T = 103 K, and reduce their pressures from ˜0.1 dyn cm-2 to ˜ 10-3 -10-5 dyn cm-2.. This places the expanded BEL clouds in the (T,P) dust forming regime of late-type giants extended atmospheres, both static and pulsing. The result applies whether the clouds have C/O abundance ratio greater or lower than 1. Photo-destruction of the grains by the quasar UV/X-ray continuum is not important, as the BEL clouds reach these conditions several parsecs from the quasar nucleus, well below the dust evaporation temperature. This result offers a new insight for the strong link between quasars and dust, and for the heavy obscuration around many quasars. It also introduces a new means of forming dust at early cosmological times, and a direct mechanism for the injection of such dust in the intergalactic medium. Since dust at high z is found only by observing quasars, our result allows far less dust to be present at early epochs, since dust only need be present where a quasar is, rather than the quasar illuminating pre-existing dust which would then need to be present in all galaxies at high z. See astro-ph/0202002 or ApJ 576, L107 (2002).

  2. The dissolution of natural and artificial dusts in glutamic acid

    NASA Astrophysics Data System (ADS)

    Ling, Zhang; Faqin, Dong; Xiaochun, He

    2015-06-01

    This article describes the characteristics of natural dusts, industrial dusts, and artificial dusts, such as mineral phases, chemical components, morphological observation and size. Quartz and calcite are the main phases of natural dusts and industrial dusts with high SiO2 and CaO and low K2O and Na2O in the chemical composition. The dissolution and electrochemical action of dusts in glutamic acid liquor at the simulated human body temperature (37 °C) in 32 h was investigated. The potential harm that the dust could lead to in body glutamic acid acidic environment, namely biological activity, is of great importance for revealing the human toxicological mechanism. The changes of pH values and electric conductivity of suspension of those dusts were similar, increased slowly in the first 8 h, and then the pH values increased rapidly. The total amount of dissolved ions of K, Ca, Na, and Mg was 35.4 to 429 mg/kg, particularly Ca was maximal of 20 to 334 mg/kg. The total amount of dissolved ions of Fe, Zn, Mn, Pb, and Ba was 0.18 to 5.59 mg/kg and in Al and Si was 3.0 to 21.7 mg/kg. The relative solubility order of dusts in glutamic acid is wollastonite > serpentine > sepiolite, the cement plant industrial dusts > natural dusts > power plant industrial dusts. The wollastonite and cement plant industrial dusts have the highest solubility, which also have high content of CaO; this shows that there are a poorer corrosion-resisting ability and lower bio-resistibility. Sepiolite and power plant industrial dusts have lowest solubility, which also have high content of SiO2; this shows that there are a higher corrosion-resisting ability and stronger bio-resistibility.

  3. Pulmonary Toxicity Studies of Lunar Dusts in Rodents

    NASA Technical Reports Server (NTRS)

    Lam, C.-W.; James, J. T.; Taylor, L.; Zeidler-Erdely, P. C.; Castranova, V.

    2009-01-01

    NASA will build an outpost on the Moon for prolonged human habitation and research. The lunar surface is covered by a layer of fine, reactive dust. Astronauts on the Moon will go in and out of the base for various activities, and will inevitably bring some dust into the living quarters. Depressurizing the airlock so that astronauts can exit for outdoor activities could also bring dust inside the airlock to the habitable area. Concerned about the potential health effects on astronauts exposed to airborne lunar dust, NASA directed the JSC Toxicology Laboratory to determine the pulmonary toxicity of lunar dust. The toxicity data also will be needed by toxicologists to establish safe exposure limits for astronauts residing in the lunar habitat and by environmental engineers to design an appropriate dust mitigation strategy. We conducted a study to examine biomarkers of toxicity (inflammation and cytotoxicity) in lung lavage fluids from mice intrapharyngeally instilled with lunar dust samples; we also collected lung tissue from the mice for histopathological examination 3 months after the dust instillation. Reference dusts (TiO2 and quartz) having known toxicities and industrial exposure limits were studied in parallel with lunar dust so that the relative toxicity of lunar dust can be determined. A 6-month histopathology study has been planned. These instillation experiments will be followed by inhalation studies, which are more labor intensive and technologically difficult. The animal inhalation studies will be conducted first with an appropriate lunar dust simulant to ensure that the exposure techniques to be used with actual lunar dust will be successful. The results of these studies collectively will reveal the toxicological risk of exposures and enable us to establish exposure limits on lunar dust for astronauts living in the lunar habitat.

  4. Do Phoretic Mites Influence the Reproductive Success of Ips grandicollis (Coleoptera: Curculionidae)?

    PubMed

    Pfammatter, Jesse A; Raffa, Kenneth F

    2015-12-01

    Ips grandicollis (Eichhoff) can be an important pest of plantation trees in the Great Lakes region. Mites commonly occur in phoretic association with this beetle, but little is known about their effects on beetle population dynamics. We assessed the effects of phoretic mites on the reproductive success of I. grandicollis using complementary correlative and manipulative approaches. First, we allowed beetles to colonize Pinus resinosa (Ait) logs from sites across Wisconsin, reared them in a common environment, and related the species identities and abundances of mites with beetle production from each log. We found a positive relationship between I. grandicollis abundance and the presence of five mite species, Histiostoma spp., Dendrolaelaps quadrisetus (Berlese), Iponemus confusus (Lindquist), Trichouropoda australis Hirschmann, and Tarsonemus spp. While the abundance of individual mite species was positively correlated with beetle abundance, assessments of mite community structure did not explain beetle reproduction. Next, we introduced beetles that either had a natural complement of mites or whose mites were mechanically reduced into logs, and compared reproductive success between these beetles. We found no difference in colonization rates or beetle emergence between mite-present and mite-reduced treatments. Collectively, these results suggest a correlative, rather than causal, link between beetle reproductive success and mite incidence and abundances. These mites and beetles likely benefit from mutually suitable environments rather than exerting strong reciprocal impacts. Although mites may have some effects on I. grandicollis reproductive success, they likely play a minimal role compared to factors such as tree quality, beetle predation, and weather.

  5. Mite species inhabiting commercial bumblebee (Bombus terrestris) nests in Polish greenhouses.

    PubMed

    Rożej, Elżbieta; Witaliński, Wojciech; Szentgyörgyi, Hajnalka; Wantuch, Marta; Moroń, Dawid; Woyciechowski, Michal

    2012-03-01

    Nests of social insects are usually inhabited by various mite species that feed on pollen, other micro-arthropods or are parasitic. Well-known negative effects of worldwide economic importance are caused by mites parasitizing honeybee colonies. Lately, attention has focused on the endoparasitic mite Locustacarus buchneri that has been found in commercial bumblebees. However, little is known of other mites associated with commercial bumblebee nests. Transportation of commercial bumblebee colonies with unwanted residents may introduce foreign mite species to new localities. In this study, we assessed the prevalence and species composition of mites associated with commercial bumblebee nests and determined if the mites are foreign species for Poland and for Europe. The study was conducted on 37 commercial bumblebee nests from two companies (Dutch and Israeli), originating from two greenhouses in southern Poland, and on 20 commercial bumblebee colonies obtained directly from suppliers. The species composition and abundance of mites inhabiting commercial bumblebee nests were determined. Seven mite species from three families were found in nests after greenhouse exploitation. The predominant mite species was Tyrophagus putrescentiae (Acaridae) that was a 100-fold more numerous than representatives of the family Laelapidae (Hypoaspis marginepilosa, H. hyatti, H. bombicolens). Representatives of Parasitidae (Parasitellus fucorum, P. crinitus, P. ignotus) were least numerous. All identified mite species are common throughout Europe, foreign species were not found. Mites were not detected in nests obtained directly from suppliers. We conclude that probably bumblebee nests are invaded by local mite species during greenhouse exploitation.

  6. Host finding behaviour of the coconut mite Aceria guerreronis.

    PubMed

    Melo, J W S; Lima, D B; Sabelis, M W; Pallini, A; Gondim, M G C

    2014-12-01

    For the coconut mite, Aceria guerreronis Keifer, its host plant, the coconut palm, is not merely a source of food, but more generally a habitat to live in for several generations. For these minute organisms, finding a new plant is difficult and risky, especially because their main mode of dispersal is passive drifting with the wind and because they are highly specialized on their host plant. Consequently, the probability of landing on a suitable host is very low, let alone to land in their specific microhabitat within the host. How coconut mites manage to find their microhabitat within a host plant is still underexplored. We tested the hypothesis that they use volatile chemical information emanating from the plant to find a specific site within their host plants and/or use non-volatile plant chemicals to stay at a profitable site on the plant. This was investigated in a Y-tube olfactometer (i.e. under conditions of a directed wind flow) and on cross-shaped arenas (i.e. under conditions of turbulent air) that either allowed contact with odour sources or not. The mites had to choose between odours from specific parts (leaflet, spikelet or fruit) of a non-infested coconut plant and clean air as the alternative. In the olfactometer experiments, no mites were found to reach the upwind end of the Y-tube: <5 % of the mites were able to pass the bifurcation of the "Y". On the cross-shaped arenas, however, a large number of coconut mites was found only when the arm of the arena contained discs of fruit epidermis and contact with these discs was allowed. The results suggest that coconut mites on palm trees are not attracted to specific sites on the plant by volatile plant chemicals, but that they arrested once they contact the substrate of specific sites. Possibly, they perceive non-volatile chemicals, but these remain to be identified. PMID:25033768

  7. Host finding behaviour of the coconut mite Aceria guerreronis.

    PubMed

    Melo, J W S; Lima, D B; Sabelis, M W; Pallini, A; Gondim, M G C

    2014-12-01

    For the coconut mite, Aceria guerreronis Keifer, its host plant, the coconut palm, is not merely a source of food, but more generally a habitat to live in for several generations. For these minute organisms, finding a new plant is difficult and risky, especially because their main mode of dispersal is passive drifting with the wind and because they are highly specialized on their host plant. Consequently, the probability of landing on a suitable host is very low, let alone to land in their specific microhabitat within the host. How coconut mites manage to find their microhabitat within a host plant is still underexplored. We tested the hypothesis that they use volatile chemical information emanating from the plant to find a specific site within their host plants and/or use non-volatile plant chemicals to stay at a profitable site on the plant. This was investigated in a Y-tube olfactometer (i.e. under conditions of a directed wind flow) and on cross-shaped arenas (i.e. under conditions of turbulent air) that either allowed contact with odour sources or not. The mites had to choose between odours from specific parts (leaflet, spikelet or fruit) of a non-infested coconut plant and clean air as the alternative. In the olfactometer experiments, no mites were found to reach the upwind end of the Y-tube: <5 % of the mites were able to pass the bifurcation of the "Y". On the cross-shaped arenas, however, a large number of coconut mites was found only when the arm of the arena contained discs of f