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PubMed2001

Intracellular 3',5'-adenosine cyclic monophosphate level regulates house dust mite-induced interleukin-13 production by T cells from mite-sensitive patients with atopic dermatitis.

We studied the relationship between cAMP and house dust mite-induced cytokine production in T cells from mite-sensitive patients with atopic dermatitis. T cells from atopic dermatitis patients secreted high level of interleukin-13 (mean 851.1 pg per ml) when cultured with autologous monocytes pulsed with Dermatophagoides pteronyssinus extract. Dermato- phagoides pteronyssinus-induced interleukin-13 secretion was not detected in normal subjects. Adenylate cyclase inhibitor MDL 12,330A and cyclic nucleotide phosphodiesterase type 4 inhibitor rolipram blocked Dermatophagoides pteronyssinus-induced interleukin-13 secretion in atopic dermatitis T cells. In atopic dermatitis T cells, cAMP level rose at 5 min after Dermatophagoides pteronyssinus stimulus then decreased to the basal level at 1 h. MDL 12,330A blocked the Dermatophagoides pteronyssinus-induced cAMP elevation while rolipram blocked its reversal. In atopic dermatitis T cells, adenylate cyclase activity increased at 5 min after Dermatophagoides pteronyssinus stimulus, followed by the increase of cyclic nucleotide phosphodiesterase activity at 15 min. In atopic dermatitis T cells, phospholipase C inhibitor ET-18-OCH3 blocked Dermatophagoides pteronyssinus-induced activation of adenylate cyclase, while rolipram, protein kinase A inhibitor H-89, and MDL 12,330A blocked the activation of cyclic nucleotide phosphodiesterase. These results suggest that Dermatophagoides pteronyssinus may first increase cAMP in atopic dermatitis T cells by activating adenylate cyclase via phospholipase C, and next decrease cAMP by activating cyclic nucleotide phosphodiesterase 4 via protein kinase A, which may be activated by adenylate cyclase-generated cAMP signal. These events are required for interleukin-13 response Dermatophagoides pteronyssinus.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1991

Medication requirements and house dust mite exposure in mite-sensitive asthmatics.

To better understand the clinical consequences of exposure to house dust mites (HDM), we investigated the relationship between treatment requirements to control symptoms in mite-allergic asthmatic patients and HDM-allergenic levels in their mattresses. This study included 49 asthmatic subjects recruited from an outpatient clinic. The protocol consisted of a questionnaire about the number of asthma attacks and treatment requirements in the last 3 months. Patients provided a sample of house dust collected from their mattresses by a standardized vacuum cleaning procedure. Mean antigen P1 equivalent defined as the sum of major allergens Der pI and Der fI (Ag P1 Eq) level was 1.34 micrograms/g dust in patients who had no treatment, 5.4 micrograms/g dust in patients who took puffs of beta 2-agonists only when required and 17.8 micrograms/g dust in patients who required daily long-term treatment. Similar relationships were demonstrated between mean Ag P1 Eq levels and the number of asthma attacks. These data support the clinical role of allergenic exposure in HDM-allergic asthmatics.

Adolescent↗
PubMed1996

Diagnostic significance of in vitro T-cell proliferative responses to house-dust mite Der p 1 in children with dust-mite allergy.

The study aimed to investigate the possible diagnostic significance of T-cell proliferative responses to purified Der p 1 antigen in allergic children with and without allergic sensitization to house-dust-mite (HDM) allergens. T-cell reactivity to purified Der p 1 antigen was analyzed in 24 children with allergic sensitization to HDM demonstrated by RAST and/or positive skin prick tests. Twelve healthy young adults and 11 children with allergic sensitizations other than HDM served as controls. Of 25 HDM-allergic patients, 16 displayed strong T-cell reactivity to Der p 1 (stimulation indices > 3): nine patients showed no T-cell proliferation despite the presence of specific IgE, and five showed no responses despite positive skin prick test. In two patients, a weak T-cell response to Der p 1 could be demonstrated in the absence of specific IgE and negative skin test result. The two affected subjects did not show evidence of mite allergy. No T-cell responses were observed in adult controls (stimulation indices < 3). We conclude that the assessment of T-cell reactivity to Der p 1 is of little value for the diagnosis of HDM allergy. The importance of T-cell proliferative responses for the study of the pathogenesis of HDM allergy remains unchallenged.

Adolescent↗
PubMed1992

Positive patch tests to whole mite culture and purified mite extracts in patients with atopic dermatitis, asthma, and rhinitis.

Patch tests with Dermatophagoides were carried out by different authors on patients with atopic dermatitis (AD) employing methods varying both in the type of allergen and in the way of performing the test. In order to examine and compare different methods and various allergenic materials and to define better the indications for this test, we performed patch tests with whole mite culture or purified mite extracts on 72 patients with AD, 40 subjects with mucosal atopy, and 32 healthy volunteers, employing different techniques of application. Positive results were obtained in 51.5% of patients with AD with specific IgE to Dermatophagoides, in 43.6% of patients with AD without this specific IgE and in 40% of subjects affected by mucosal atopy and having specific IgE to Dermatophagoides. From a technical point of view the simple application of the allergenic material on healthy skin gave the best results. Our data show that patch tests with Dermatophagoides extracts could contribute to a better immunoallergologic characterization both of patients with AD and patients with mucosal atopy.

Adolescent↗
PubMed1979

A trial of house dust mite extract in bronchial asthma. Mite Allergy Subcommittee of the Research Committee of the British Thoracic Association.

Patients with asthma considered to be due to house dust mite allergy were allocated at random to treatment with (a) increasing weekly injections of house dust mite extract for 18 weeks followed by monthly injections to complete 18 months of treatment; (b) similar injections for 18 weeks followed by placebo injections up to 18 months or (c) placebo injections for 18 months. Fifty-six patients completed at least six months of observation. In patients not on corticosteroids the treated group did a little better than the controls as judged by night asthma scores, discontinuation of bronchodilators and overall blind assessment of the records by a panel of independent physicians. No benefit was apparent by extending treatment from 18 weeks to 18 months. In contrast, patients on corticosteroids given placebo injections did a little better than the treated group. The extract used was stronger than the commercially available preparation and the injections had to be stopped in one-sixth of the patients because of side-effects. The improvement in patients not on corticosteroids in this trial was of doubtful clinical importance.

Adolescent↗
PubMed1981

Mites in cat ears: a source of cross antigenicity with house dust mites. Preliminary report.

Dermatophagoides had been established as an antigen in house dust by many investigators. An untapped source of cross antigenicity is presented in this paper, namely, Otodectes cyanotis, the mite found in the ears of millions of cats. House dust samples for mite species in other parts of the world may not be similar to samples in the United States since in most other countries the cat exists outdoors, whereas in this country it is a household pet.

Animals↗
PubMedDate not supplied

House dust mites and Der p I in Tenerife (Canary Islands, Spain): the relative importance of other non Dermatophagoides spp mites.

BACKGROUND: House dust mites constitute the major etiologic factor causing sensitization and asthma its geographical distribution map is quite well known, although it is not yet complete. Home environments world-wide show mites that mainly belong to the Piroglyphidae family, the D. pteronyssinus specie being the predominant one. However others have also been considered of interest. OBJECTIVE: The aim of this work was to study the species and to determine the levels of Der p I, Der f I and group II of allergens of Dermatophagoides. Present in houses from Tenerife, Canary Islands (Spain). METHODS: Dust samples were collected in 130 houses. RESULTS: D. pteronyssinus was found in 121 (95.3%) homes, being the predominant species in 113 (89%). In 69 (55%) homes, Dermatophagoides spp. were found together with other species from other generus. Mean values for Der p I were 13.7 +/- 13.88 (mean +/- SD), for Der f 1 1.05 +/- 1.83 and for the Group I of allergens 7 +/- 6.77. CONCLUSION: Although D. pteronyssinus is the predominant species in our area, there are others that may be off importance and should be taken into consideration in the diagnostic, home disallergenization and later treatment of patients.

Allergens↗
PubMed2005

Induced production of extrafloral nectar in intact lima bean plants in response to volatiles from spider mite-infested conspecific plants as a possible indirect defense against spider mites.

We found that intact lima bean plants increased the secretion of extrafloral nectar (EFN) after exposure to Tetranychus urticae-induced plant volatiles. Predatory mites, Phytoseiulus persimilis, dispersed more slowly from an exposed intact plant than from a control plant (plant exposed to volatiles from intact conspecific). The predators also dispersed more slowly from those plants that were provided with extra EFN than from untreated plants. We further show that EFN was a potential alternative food source for P. persimilis. From these results, we concluded that increased EFN was involved in the slow dispersal of P. persimilis from the plants exposed to herbivore-induced plant volatiles. Our data suggest that the increase of EFN in an HIPV-exposed intact plant could be an induced indirect defense against spider mites.

Fabaceae↗
PubMedDate not supplied

[The variability of the scabies mite Sarcoptes scabiei de Geer (Acariformes, Sarcoptidae) in relation to the epidemiology of scabies. 4. The variability of the mite population on a patient and its focal variability].

The authors analyze the individual variability of the agent of scabies in populations on individual patients and in foci of the disease. They define an elementary micropopulation and a focal population notions. A total of 763 females, collected from the hands of 100 patients with scabies were examined. The findings evidence that the degree of the chetoid covering joining in the mite females, assessed in grades, may be regarded as an indicator of the population status in the pathologic process. Grades II and III females predominate in the mite population on the patients during the initial period of the disease (up to a month), whereas in the course of a full-bloom process (over a month) Grades I and 0 females prevail. The attendant exo- and endogenous factors shift the grade composition of the females towards the higher grades whatever the length of the disease. A great variety of the females in focal populations evidences reinfection and continuity of the process.

Animals↗
PubMed1993

Intra-species cross-reactivity of house dust mite allergens separated by protein blotting and detected by selective elution of mite components and IgE antibodies.

A complex and varied antibody response to allergens, in particular Dermatophagoides pteronyssinus, is observed in the serum of allergic patients. To examine the role of cross-reacting antigenic determinants in allergy, a strategy has been devised for isolating antibody populations that bind to individual polypeptides of an allergen source separated by sodium dodecyl sulfate-polyacrylamide electrophoresis and electroblotted to nitrocellulose. Polypeptides are identified on the blots, desorbed and coupled to CNBr-activated paper discs. The coupled discs are then used as immunoadsorbent surfaces for the binding of antibodies from allergic sera. Antibodies eluted from the polypeptide immunoadsorbents are then used to reprobe protein blots of the allergen. Results are presented which demonstrate strong cross-reaction between two major mite allergens, Der p I and Der p III, and some weaker intra-species cross-reactivities.

Allergens↗
PubMed1996

Chemical ecology of astigmatid mites--XLV. (2R, 3R)-epoxyneral: sex pheromone of the acarid mite Caloglyphus sp. (Acarina: Acaridae).

(2R,3R)-2,3-Epoxy-3,7-dimethyl-6-octenal [(2R,3R)-epoxyneral] was identified as the female sex pheromone from an acarid mite, Caloglyphus sp. (Astigmata:Acaridae), whose phoretic hypopi had been collected from the Cockchafer, Melolontha japonica (Coleoptera: Scarabaeidae). Sexual activity of the males was induced by exposure to a 0.1-1 ng dose of synthetic (2R,3R)-epoxyneral. The enantiomer of the pheromone, (2S,3S)-epoxyneral, was inactive and its admixture did not inhibit the activity of the natural pheromone.

Aldehydes↗
PubMed2000

IL-4 production by PBMCs on stimulation with mite allergen is correlated with the level of serum IgE antibody against mite in children with bronchial asthma.

BACKGROUND: Although IL-4, IL-13, and IFN-gamma are known to affect IgE synthesis, it remains unclear which one plays the most important role in in vivo IgE synthesis in atopic patients. OBJECTIVE: The aim of this study is to clarify the difference in importance among these cytokines in up-regulation of IgE synthesis in atopic patients. METHODS: We measured IL-4, IL-13, and IFN-gamma production by PBMCs on stimulation with house dust mite (HDM) in 23 children, 3 to 15 years old, with bronchial asthma (BA) and analyzed the correlation with HDM-specific IgE antibody levels expressed as HDM IgE radioallergosorbent test (RAST) results. RESULTS: The production of IL-4 and IL-13 by PBMCs on stimulation with HDM was significantly higher in children with BA than in nonatopic control subjects (IL-4, 752.9 +/- 365.9 vs 312.3 +/- 230.0 fg/mL, P <.001; IL-13, 21.9 pg/ml [<12.0-77.6] vs <12.0, P <.01). IL-4 production showed a close positive correlation with HDM IgE RAST (r = 0.71, P <.001), which was distinctly stronger than that between IL-13 production and HDM IgE RAST (r = 0.46, P <.05). IFN-gamma production was neither different between children with BA and nonatopic control subjects (7. 24 [1.54-33.90] pg/mL vs 11.2 [1.66-75.9] pg/mL) nor correlated with HDM IgE RAST levels. Essentially the same result was obtained by stimulation of PBMCs with a purified HDM major allergen Der f 1. CONCLUSION: IL-4 is likely to be the most important cytokine in up-regulation of in vivo IgE synthesis against HDM in children with BA.

Adolescent↗
PubMed2000

House dust mite-specific IgE antibodies in induced sputum are associated with sputum eosinophilia in mite-sensitive asthmatics.

BACKGROUND: Although allergen-specific IgE antibodies have been considered to play an important role in the pathogenesis of atopic asthma, the role of IgE antibodies in the development of airway inflammation is not well defined. OBJECTIVE: To evaluate the association between allergen-specific IgE antibodies and inflammation of the asthmatic airway. METHODS: We measured house dust mite (HDM; Dermatophagoides farinae)-specific IgE antibodies in both serum and induced sputum from 16 HDM-sensitive asthmatic patients, and evaluated their association with sputum eosinophilia and eosinophil cationic protein (ECP) levels in induced sputum. RESULTS: Levels of HDM-specific IgE antibodies in induced sputum were significantly higher in asthmatic patients than in controls (P < .01). In asthmatic patients, levels of HDM-specific IgE antibodies were significantly higher in induced sputum samples with eosinophilia (sputum eosinophil count > or = 5% of 200 counted non-squamous cells) than in those without eosinophilia (P < .05). There were no significant differences in serum levels of HDM-specific IgE antibodies between asthmatic patients with sputum eosinophilia and asthmatic patients without sputum eosinophilia. In asthmatic patients, sputum ECP levels were significantly correlated with levels of HDM-specific IgE antibodies (r = 0.60, P = .01) in induced sputum but not with those in serum. CONCLUSION: We conclude that allergen-specific IgE antibodies in induced sputum from atopic asthmatics are associated with sputum eosinophilia. This result suggests that IgE-dependent mechanisms are involved in eosinophilic inflammation of the airway in atopic asthmatics.

Allergens↗
PubMed2000

Effects of light on the tritrophic interaction between kidney bean plants, two-spotted spider mites and predatory mites, Amblyseius womersleyi (Acari: Phytoseiidae).

By analyzing the volatiles from Tetranychus urticae-infested kidney bean plants (Phaseolus vulgaris) at different times for two days, we found that they were mainly produced in the light. Tetranychus urticae showed a higher oviposition rate and spent more time feeding during the day (in the light) than at night (in the dark). Infested leaves placed in the light attracted the predatory mite Amblyseius womersleyi, whereas those that were placed in the dark for at least 2 h in daytime did not. This indicates that presence or absence of light affects the production of herbivore-induced plant volatiles. Amblyseius womersleyi dispersed more frequently and consumed more T. urticae eggs during the day (in the light) than at night (in the dark), whereas their oviposition rate did not differ between day and night. Presence or absence of herbivore-induced plant volatiles in the surroundings did not affect dispersal, predation or oviposition rates of A. womersleyi. These results show that A. womersleyi's behavior coincides with the production pattern of herbivore-induced plant volatiles.

Animals↗
PubMed2001

Biological control of strawberry tarsonemid mite Phytonemus pallidus and two-spotted spider mite Tetranychus urticae on strawberry in the UK using species of Neoseiulus (Amblyseius) (Acari: Phytoseiidae).

Two species of Neoseiulus, N. californicus and N. cucumeris, showed potential for biocontrol of phytophagous mites on strawberry. N. californicus controlled Tetranychus urticae on potted strawberry plants in a gauze-sided glasshouse at temperatures comparable to early summer in the UK (8-20 degrees C). Both species of phytoseiid reduced numbers of the tarsonemid Phytonemus pallidus on potted strawberry plants under glasshouse conditions (15-23 degrees C). In several experiments reductions in the range of 71-81% in numbers of tarsonemid active stages and eggs, compared to non-release plants, were obtained. The importance of establishing a suitable predator: prey ratio at an early stage was demonstrated in an experiment where an initial ratio of 1 N. cucumeris: 10 P. pallidus gave a greater degree of control than 1:20 or 1:40.

Animals↗
PubMed2003

Chemical ecology of oribatid mites III. Chemical composition of oil gland exudates from two oribatid mites, Trhypochthoniellus sp. and Trhypochthonius japonicus (Acari: Trhypochthoniidae).

The composition of oil gland exudates from two oribatid mites, Trhypochthoniellus sp. and Trhypochthonius japonicus, was studied with reference to the related species Trhypochthoniellus crassus. Trhypochthoniellus sp. contained a mixture of seven compounds; (Z,Z)-6,9-heptadecadiene, geranial, 3-hydroxybenzene-1,2-dicarbaldehyde (gamma-acaridial), neryl formate, neral, (Z)-8-heptadecene and geranyl formate in decreasing order of abundance. The profile of the components from T. japonicus consisted of two types depending on the locality of sampling with unknown reason; one possessing a mixture of eight compounds [(Z,E)-farnesal, gamma-acaridial, (Z,Z)-6,9-heptadecadiene, (E,E)-farnesal, (Z)-8-heptadecene and geranial in decreasing order] together with two unknown compounds, and the other composed of the same set of compounds together with 2-hydroxy-6-methylbenzaldehyde as the most abundant component. Relative abundance among common components was consistent between the two types of T. japonicus. Profiles of components differed among three species including T. crasus. The phylogenetic relationship between Oribatida and Astigmata was discussed based on secretory compounds commonly distributed between these two suborders.

Acyclic Monoterpenes↗
PubMed2000

Long-term effects of specific immunotherapy, administered during childhood, in asthmatic patients allergic to either house-dust mite or to both house-dust mite and grass pollen.

In a retrospective study, asthmatic patients allergic to either house-dust mite (HDM) (Dermatophagoides pteronyssinus) (n = 34) or to both HDM and grass pollen (GP) (n = 14), and who were treated with specific immunotherapy (SIT) during childhood (mean duration of SIT: 61 +/- 9.70 months), were re-evaluated in early adulthood after mean cessation of SIT for 9.3 +/- 2.76 years. The results were compared to those of a control group of asthmatic patients (n = 42) with comparable asthma features, who were treated with appropriate antiasthmatic drugs during childhood, but who never received SIT. Re-evaluation was carried out with a standardized questionnaire, skin prick tests (SPT), and lung-function assessments. At the time of re-evaluation, the mean age in the SIT-treated group was 23.1 +/- 3.50 years; in the control group, it was 22.7 +/- 3.40 years. At re-evaluation, the risk of frequent asthmatic symptoms was three times higher in the control group than in the SIT-treated group (prevalence ratio: 3.43; P = 0.0006). The frequent use of antiasthmatic medication was also more pronounced in the control group, although the difference was not statistically significant (P=0.38). Lung-function parameters and results of SPT with HDM were comparable in both groups. It is concluded that SIT has long-term effects on asthmatic symptoms in young adults.

Adult↗
PubMed2003

Distribution of house dust mite allergen: comparing house dust mite allergen levels in dust samples collected from different sites on living room floors with smooth coverings.

BACKGROUND: The distribution of house dust mite allergen (Der p1) in living rooms with smooth floor coverings, as measured in the middle compared with the border of the floor was investigated. It was hypothesized that activity causes displacement of Der p1, from the middle towards the border. METHODS: Dust samples from the middle and border of 50 floors with smooth coverings were collected and analysed on Der p1 content in a standardized way. RESULTS: The Der p1 exposure expressed as per unit area (ng/m2) showed that border samples contained significantly more Der p1 compared with middle samples (median: 2.57 vs 0.27, respectively, P = 0.023). Presence of pets and presence of more than two inhabitants increased the difference. When expressed as per unit weight of dust (ng/g), significant differences were only detected when comparing Der p1 content of samples collected in households with three or more inhabitants [median: 2 (border) vs 53 (middle), respectively; P = 0.035]. CONCLUSIONS: The Der p1 is unequally distributed on living room floors with smooth coverings, most likely because of displacement of dust from the middle towards the border due to activity. Expression as ng/g of dust and ng/m2 could not obviously be interchangeable.

Animals↗