Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MITES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,585 records · Page 88Linked to original sources
PubMed1997

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

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.

Allergens↗
PubMed1997

The effect of frequent vacuum cleaning on the house dust mite allergen, Der p 1 in carpets: a pilot study.

AIM: To determine the effect of frequent vacuum cleaning of carpets on Der p 1, the major group one allergen of the house dust mite Dermatophagoides pteronyssinus. METHODS: Nine rooms and three hallways in the resident medical officers quarters at Wellington Hospital were regularly vacuum cleaned (daily, except weekends) over a five week period. Dust samples were collected before and at weekly intervals for Der p 1 measurement by a double monoclonal antibody ELISA technique. RESULTS: Der p 1 concentrations progressively declined from an initial geometric mean level (95% CI) of 4.47 micrograms/g fine dust (0.11-21.73) to 1.83 micrograms/g (0.29-9.57) after five weeks, a mean reduction of 48.0% (31.7-65.5). Similarly when expressed per unit area Der p 1 levels declined from 6.35 micrograms/m2 (1.15-35.16) to 1.66 micrograms/m2 (0.33-9.04), a mean reduction of 68.5% (58.6-78.3). CONCLUSIONS: Frequent vacuum cleaning over a short time significantly reduces house dust mite allergen levels in carpets. Larger long term trials are warranted to determine if greater reductions are possible that would be beneficial to house dust mite sensitive individuals.

Animals↗
PubMed1998

[A clinical evaluation of clustered immunotherapy in house-dust-mite-sensitive adult bronchial asthma].

Clustered immunotherapy (C-IT) using house-dust (HD) antigen was performed in eight HD-mite-sensitive adult bronchial asthmatics. Six mg of mequitazine was given 2 hours before each visit. For each visit, injections of antigen were performed four times with an hour interval. Either 0.1 ml of 10-fold concentration of the HD or a final dose at the end of the fifth week was determined as a maintenance dose. All cases have reached to ten-fold concentration of the HD antigen within 5 weeks and been able to introduce maintenance therapy without any systemic reaction. Following C-IT, a rapid increase in morning peak expiratory flow rate was observed which is followed by decrease in clinical scores. Furthermore, an increase in mite-specific IgG4 antibody and a decrease in peripheral blood eosinophils were observed 16 weeks following C-IT. These results suggest that C-IT using HD antigen can be performed safely and securely and provides rapid immunological responses as well as clinical benefit in HD-mite-sensitive adult asthmatics.

Adolescent↗
PubMed1998

Sensitization to storage mites in urban working environment.

This paper presents an analysis of a medical history questionnaire, skin prick test and specific IgE to storage mites Lepidoglyphus destructor and Tyrophagus putrescentiae performed on 26 male paper mill workers and 36 postmen. Positive prick test were considered urticas with the mean diameter of 3 mm or over. Increased specific IgE were considered values of over 0.35 kU/L. Paper mill workers manifested a significantly higher frequency of positive test results, increased specific IgE and positive prick test, to L. destructor and T. putrescentiae than did the postmen. Paper mill workers with increased specific IgE manifested significantly greater mean skin reactivity to T. putrescentiae than to L. destructor. Respiratory symptoms were found in 40% of paper mill workers with positive test results to L. destructor, and in 53.8% with positive test results to T. putrescentiae. All postmen with positive test results to L. destructor and 83.3% with positive test results to T. putrescentiae had respiratory symptoms. The study results indicate that it is necessary to monitor sensitization to mites and to establish methods for identification and quantification of mites in the working and general environment.

Adult↗
PubMed1996

Ultrastructure and Pathology of Microsporidium phytoseiuli n. sp. Infecting the Predatory Mite, Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae)

Ultrastructure and pathology of Microsporidium phytoseiuli n. sp. infecting the predatory mite Phytoseiulus persimilis Athias-Henriot is described using light and transmission electron microscopy. Infected mites showed no gross, external symptoms. All observed stages of the parasite had unpaired nuclei. Schizonts were commonly observed within nuclei of digestive cells of the ventriculus and within the cytoplasm of cells lining the cecal wall and in muscle tissue underlying it. Sporoblasts and spores occurred in the nuclei and cytoplasm of digestive cells within the ventriculus, in cortical regions of the sub- and supraesophageal ganglia, within the cecal wall and muscle tissue, and in parenchyma cells underlying the cuticle. Mature spores were also observed in developing eggs within gravid females. These were broad- to elongate-ovoid, measured 4.33 ± 0.35 x 1.27 ± 0.15 &mgr;m (electron micrographs), 5.37 ± 0.46 x 2.22 ± 0.17 &mgr;m (fixed and stained), and 5.88 ± 0.34 x 2.22 ± 0.19 &mgr;m (fresh) and had an isolfilar polar filament coiled 12 to 15 times within the posterior two-thirds. Within cells, individual spores appeared to be in direct contact with host cytoplasm, while groups of spores were infrequently observed within interfacial envelopes. Groups of 4, 8, to more than 16 spores were observed by light microscopy, while 8 was the maximum observed by electron microscopy. No spores were observed in Tetranychus urticae, a mite used as food during this study.

Journal Article↗
PubMed2003

Temperature and sex allocation in a spider mite.

Although temperature is the most important environmental factor regulating arthropod development and reproduction, its influence on sex allocation in haplodiploid arthropods remains largely unexplored. We investigated under laboratory conditions how maternal age and temperature mediate offspring sex ratio of the spider mite Tetranychus mcdanieli (Acari: Tetranychidae). Over nine temperature regimes, female-biased sex ratios were consistently observed, varying from 57 to 87% among progeny produced over lifetime. Spider mite sex ratio was affected by maternal age: more male progeny were produced at both the beginning and the end of the female lifespan, yielding a dome shaped curvilinear relationship. This pattern of variation with age probably results from constraints on using sperm at young ages and sperm depletion or viability at older ages. We found a significant curvilinear relationship between temperature and sex ratio. The proportion of female offspring was lowest at intermediate temperatures and highest at extreme temperatures. We suggest that increased female-biased sex ratio at extreme temperatures is an evolutionary response of spider mites to deteriorating habitats as, in the Tetranychidae, females have better capacities than males to disperse and survive under harsh conditions.

Aging↗
PubMed2006

Amensalism via webs causes unidirectional shifts of dominance in spider mite communities.

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.

Analysis of Variance↗
PubMed2006

Assessment of sublethal effects of clofentezine on life-table parameters in Hawthorn spider mite (Tetranychus viennensis).

A leaf disc bioassay was employed in the laboratory to assess the population responses of Tetranychus viennensis Zacher to clofentezine at three concentrations (LC(10), LC(25) and LC(50)) in three successive generations. Life-table parameters were calculated in each acaricide exposure regime and compared by jackknife procedures. Clofentezine treatments in the juvenile stages significantly delayed development of the mites, and this delay increased with increasing dose but decreased as the mites developed. Exposure to clofentezine reduced the net reproduction rate (R(0)) in a concentration-dependent manner. The LC(50) treatment had strong effects on the hatchability of eggs produced by surviving females. Hatch rate dropped from 0.83 in the untreated control to 0.51 in the third generation. When exposed to constant concentrations of clofentezine in three successive generations, the intrinsic rate of increase and R(0) of the mites decreased significantly, but they increased significantly when exposed to decreasing concentrations. Unexposed offspring of the exposed mother also displayed increases in R(0) and the jackknife procedures indicated no significant differences in R(0) between LC(10) and LC(25) offspring and their mothers vs. the control, while R(0) in unexposed LC(50) offspring was significantly higher than their mother's, but lower than that in the control. These changing patterns of r(m) reveal that acaricide effects at the population level strongly depend on the life-history characteristics of T. viennensis and the chemical mode of action.

Aging↗
PubMed2006

Chemical alarm and defence in the oribatid mite Collohmannia gigantea (Acari: Oribatida).

The multicomponent oil gland secretion of Collohmannia gigantea, a middle-derivative mixonomatan oribatid mite, is demonstrated to possess alarm pheromonal and allomonal properties. Four components of the secretion, namely the monoterpenes neryl formate, neral, geranial and the aromatic 2-hydroxy- 6-methyl-benzaldehyde (2,6-HMBD), showed moderate to strong alarm pheromonal activity in adult mites. Naturally elicited response is due to neral (about 50% of the secretion) and probably 2,6-HMBD (only 5% of the secretion, but strong alarm pheromonal activity). This is the second report of an alarm pheromone in Oribatida. Tridecane and pentadecane (=the hydrocarbon fraction of the secretion) did not evoke evident behavioural reactions, and most likely serve as solvents and spreading agents for the pheromonal-active components. Alarm reactions were characterized by a short recognition phase (waving movements with legs I), followed by shrinking back and panic escape from the scent source. In addition, all six components of the oil gland secretion, including the hydrocarbons, exhibited strong allomonal properties against a model oribatid predator, the scydmaenid beetle, Euconnus (Tetramelus) oblongus. Considering the widespread semiochemical properties of oil gland secretions in astigmatid mites (=a highly derivative oribatid group), these results furnish evidence for a phylogenetically early origin of defensive and communicative roles of oil gland secretions in oribatids. These roles include alarm communication, defence and the production of anti-fungal compounds.

Acaridae↗
PubMed2007

Mobilization and evolutionary history of miniature inverted-repeat transposable elements (MITEs) in Beta vulgaris L.

We have identified three families of miniature inverted-repeat transposable elements (VulMITEs) in the genome of sugar beet (Beta vulgaris L.), evidently derived from a member of the Vulmar family of mariner transposons. While VulMITEs I are typical stowaway-like MITEs, VulMITEs II and VulMITEs III are rearranged stowaway elements of increased size. The integration of divergent moderately and highly repetitive sequences into VulMITEs II and, in particular in VulMITEs III, respectively, shows that amplification of repetitive DNA by MITEs contribute to the increase of genome size with possible implications for plant genome evolution. Fluorescent in-situ hybridization (FISH), for the first time visualizing stowaway MITE distribution on plant chromosomes, revealed a dispersed localization of VulMITEs along all B. vulgaris chromosomes. Analysis of the flanking sequences identified a dispersed repeat as target site for the integration of the stowaway element VulMITE I. Recent transposition of VulMITE I, which most likely occurred during the domestication of cultivated beets, was concluded from insertional polymorphisms between different B. vulgaris cultivars and species.

Base Sequence↗
PubMed1984

Detection of serum antibodies to sarcoptic mange mite antigens by the passive hemagglutination assay in pigs infested with Sarcoptes scabiei var. suis.

Development and remission of the clinical signs of sarcoptic mange in pigs experimentally infested once and twice with Sarcoptes scabiei var. suis were described. Encrusted lesions in the ears of pigs and a general dermatitis were observed 3 weeks after infestation, but subsided gradually. Specific antibody activity, in titers averaging 1:16 000 in sera from rabbits immunized with mite extracts and 1:512 in the serum from a pig artificially infested with sarcoptic manage and then twice immunized with mite extract, was detected with the passive hemagglutination assay with tanned bovine red blood cells. Titers ranging from 1:40 to 1:160 were detected in sera from experimentally-infested animals. Only 3 of 75 sera from chronically naturally-infested pigs exhibited antibody titers of 1:40 to the mite extract.

Animals↗
PubMed2006

Detection of a mariner-like element and a miniature inverted-repeat transposable element (MITE) associated with the heterochromatin from ants of the genus Messor and their possible involvement for satellite DNA evolution.

The satellite DNA of ants Messor bouvieri, M. barbarus and M. structor, studied in a previous paper, is organized as tandemly repeated 79-bp monomers in the three species showing high sequence similarity. In the present paper, a mariner-like element (Mboumar) and a new MITE (miniature inverted-repeat transposable element) called IRE-130, inserted into satellite DNA from M. bouvieri, are analyzed. The study of Mboumar element, of its transcription and the putative transposase that it would encode, suggests that it could be an active element. Mboumar elements inserted into IRE-130 elements have also been detected. It is the first time, to our knowledge, that a MITE has been described in Hymenoptera and it is also the first time that a mariner-like element inserted into a MITE has been detected. A mariner-like element, inserted into satellite DNA from M. structor and in M. barbarus, also has been found. The results seem to indicate that transposition events have participated in the satellite DNA mobilization and evolution.

Amino Acid Sequence↗
PubMed2004

Using rice to understand the origin and amplification of miniature inverted repeat transposable elements (MITEs).

Recent studies of rice miniature inverted repeat transposable elements (MITEs), largely fueled by the availability of genomic sequence, have provided answers to many of the outstanding questions regarding the existence of active MITEs, their source of transposases (TPases) and their chromosomal distribution. Although many questions remain about MITE origins and mode of amplification, data accumulated over the past two years have led to the formulation of testable models.

DNA Transposable Elements↗
PubMed2006

Efficacy of sublingual immunotherapy with high-dose mite extracts in asthma: a multi-center, double-blind, randomized, and placebo-controlled study in Taiwan.

Sublingual immunotherapy (SLIT) has been recommended as a viable alternative to subcutaneous injection therapy in the treatment of airway allergies, though more data is needed from well-controlled studies for documenting its efficacy in different ethnic populations. Ninety-seven children (age range 6-12 years), mild-to-moderate asthma with a single sensitization to mite allergen, were enrolled from 5 medical centers in Taiwan to evaluate the efficacy and safety of SLIT with standardized mite extracts, which contain Dermatophagoides pteronyssinus (D.p.) and Dermatophagoides farinae (D.f.). Patients were double blinded and randomly assigned to either a SLIT or placebo group. Following 24 weeks of study period, symptom and medication scores, lung function tests, skin prick tests, total serum IgE, and specific IgE to D.p. and D.f. were recorded. The results showed that there was statistically significant difference between these two groups in the analysis of daily (P=0.011), nighttime (P=0.028), and daytime (P=0.009) asthmatic scores after 24 weeks of treatment. Patients receiving SLIT improved their forced vital capacity (FVC), forced expiratory volume in 1s (FEV1), and peak expiratory flow (PEF) as compared to baseline (P=0.042, P=0.048, and P=0.001, respectively). No differences were found in skin prick test, total serum IgE and specific IgE to D.p. and D.f. Tolerance with high-dose SLIT was good with few minor adverse events reported. Our results indicated that a 24-week SLIT is of clinical benefit to mite-sensitive asthmatic children in Taiwan.

Administration, Sublingual↗
PubMed2005

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

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.

Animals↗
PubMed2006

Phylogeny of parasitiform mites (Acari) based on rRNA.

Acari (mites and ticks) form one the most diverse lineages of arthropods, but basal relationships in the group are still poorly understood. The current study addresses this issue for one of its two main lineages, the order Parasitiformes. Relationships are examined at the subordinal and infraordinal level using complete 18S and partial 28S nuclear rRNA sequence data. Most currently recognized lineages are recovered with good support, suggesting that nuclear rRNA, and specifically 18S rRNA, is very well suited for analyzing relationships at this level in this lineage. These results were found despite quite variable rates of sequence evolution, with rates "ratcheting up" from relatively low in most non-mite arachnid lineages, to intermediate in Pseudoscorpiones, the mite order Acariformes, and the parasitiform suborders Opilioacarida, Holothyrida, and Ixodida, to high in the parasitiform suborder Mesostigmata. The most species rich mesostigmatid infraorder, Dermanyssina, shows huge distances to the outgroups, but remarkably low within-group divergence in nuclear rRNA. This suggests the possibility of a relatively recent origin of this lineage.

Acari↗
PubMed2001

Rapid cold hardening in the predatory mite Euseius (Amblyseius) finlandicus (Acari: Phytoseiidae).

A rapid cold hardening response was studied in diapause and non-diapause females of the predatory mite Euseius finlandicus. When laboratory reared diapause and non-diapause females were transferred and maintained from the rearing temperature of 20 degrees C for 2 h to -11.5 degrees C and -10 degrees C, 10 to 20% survived respectively. However, conditioning of diapause females for 4 h at a range of temperatures from 0 to 10 degrees C before their exposure for 2 h to -11.5 degrees C, increased survival to approximately 90%. Similarly, conditioning of non-diapause females for 4 h at 5 degrees C before their exposure for 2 h to -10 degrees C increased survival to 90%. A similar rapid cold hardening response in both diapause and non-diapause females was also induced through gradual cooling of the mites, at a rate of approximately 0.4 degrees C per min. The rapid increase in cold tolerance after prior conditioning of the mites to low temperatures, was rapidly lost when they returned to a higher temperature of 20 degrees C. Rapid cold hardening extended the survival time of diapause and non-diapause females at sub-zero temperatures. The cost of rapid cold hardening in reproductive potential after diapause termination was negligible. In non-diapause females, however, the increase in cold tolerance gained through gradual cooling could not prevent cold shock injuries, as both fecundity and survival were reduced.

Journal Article↗
PubMed2001

Photoperiodic time measurement in insects and mites: a critical evaluation of the oscillator-clock hypothesis.

The validity of the oscillator-clock hypothesis for photoperiodic time measurement in insects and mites is questioned on the basis of a re-interpretation of available experimental evidence. The possible role of the circadian system in photoperiodism in arthropods is critically reviewed. Apart from the outcome of kinetic experiments, based on diel and non-diel light/dark cycles, evidence from various genetic and physiological experiments is discussed in relation to the oscillator-clock hypothesis. The conclusion is that photoperiodic time measurement in insects and mites is performed by a non-circadian 'hourglass' clock. Experimental evidence suggests a non-clock role for the circadian system in the photoperiodic mechanism of insects and mites.

Journal Article↗