Nitrophorins and related antihemostatic lipocalins from Rhodnius prolixus and other blood-sucking arthropods.
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Recent gene sequence and crystal structure determinations of salivary proteins from several blood-sucking arthropods have revealed an unusual evolutionary relationship: many such proteins derive their functions from lipocalin protein folds. Many blood-sucking arthropods have independently evolved the ability to overcome a host organism's means of preventing blood loss (called hemostasis). Most blood feeders have proteins that induce vasodilation, inhibit blood coagulation, and reduce inflammation, but do so by distinctly different mechanisms. Despite this diversity, in many cases the antihemostatic activities in such organisms reside in proteins with lipocalin folds. Thirteen such lipocalins are described in this review, with a particular focus on the heme-containing nitrophorins from Rhodnius prolixus, which transport nitric oxide, sequester histamine, and disrupt blood coagulation. Also described are the antiplatelet compounds RPAI, moubatin, and pallidipin from R. prolixus, Ornithodoros moubata, and Triatoma pallidipennis; the antithrombin protein triabin from T. pallidipennis; and the tick histamine binding proteins from Rhipicephalus appendiculatus. (+info)
Aggregation pheromone activity of the female sex pheromone, beta-acaridial, in Caloglyphus polyphyllae (Acari: Acaridae).
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Caloglyphus (= Sancasania) polyphyllae discharges from a pair of opisthonotal glands a characteristic set of volatiles, i.e. three monoterpenes and seven hydrocarbons. Among them, beta-acaridial, which is known as the female sex pheromone of the species and has antifungal activity, was newly identified as the aggregation pheromone for unfeeding and unmating mites. Feeding mites, however, exhibited sexually aroused behavior instead of the tendency to cluster when exposed to beta-acaridial. This is the first example of the compound demonstrating two pheromone functions depending upon the circumstances faced by the mites. (+info)
Evaluation of the acarofauna of the domiciliary ecosystem in Juiz de Fora, State of Minas Gerais, Brazil.
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From August 1999 to January 2000, samples of house dust were collected from 160 domiciles in the city of Juiz de Fora, State of Minas Gerais, Brazil. In 36 of these domiciles kitchen samples were obtained. Prevalence rate was 77.5%, varying according to the geographical sector. There were found 2,278 specimens of mites, with 1,530 (67.2%) in the adult stage and 748 (32.8%) in immature forms. The main species found were Dermatophagoides pteronyssinus, D. farinae, Euroglyphus maynei, Blomia tropicalis and Tyrophagus putrescentiae. In a minor incidence we found Lepidoglyphus destructor, Suidasia pontificiae, Chortoglyphus arcuatus, Cheyletus malaccensis, C. fortis, Ker bakeri, Cheletonella vespertilionis, C. caucasica and others. C. vespertilionis and C. caucasica were identified for the first time in the domiciliary ecosystem and in Brazil. The abundance rate and the infestation intensity were analyzed. There was a varied correlation between climatic conditions and positive domiciles and number of mites. The difference between the number of positive domiciles in the urban area and in the expanding urban area was significant and so was the difference between samples from the domiciles compared to those from the kitchens. (+info)
Exogenous ACC enhances volatiles production mediated by jasmonic acid in lima bean leaves.
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We report the synergistic effects of exogenous 1-aminocyclopropane-1-carboxylic acid (ACC) and jasmonic acid (JA) on production of induced volatiles by excised lima bean leaves. Application of ACC alone to leaves induced trace amounts of volatiles. ACC positively affected three JA-induced volatiles, (E)- and (Z)-beta-ocimene, and (Z)-3-hexenyl acetate. The ethylene inhibitor, silver thiosulfate, inhibited the production of these compounds. The results suggest synergistic effects of JA and ACC on inducible volatile production by lima bean leaves. Furthermore, lima bean leaves treated with JA plus ACC became more attractive to predatory mites, Phytoseiulus persimilis, than those treated with JA alone. (+info)
(4E)-dehydrocitrals [(2E,4E)- and (2Z,4E )-3,7-dimethyl-2,4,6-octatrienals] from acarid mite Histiogaster sp. A096 (Acari: Acaridae).
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A mixture of two monoterpenes was obtained as the opisthonotal gland secretion from unidentified Histiogaster sp. A096 (Acari: Acaridae), and their structures were elucidated to be (4E)-dehydrocitrals [(2E,4E)- and (2Z,4E)-3,7-dimethyl-2,4,6-octatrienals] by GC/MS, GC/FT-IR, UV and 1H-NMR spectra. Both isomers of (4E)-dehydrocitral prepared by syntheses in 4 steps from 3-methyl-2-butenal with 34.2% yields (based on the ylide) were separated by column chromatography into the (2E,4E)- and (2Z,4E)-3,7-dimethyl-2,4,6-octatrienal. Mass spectra together with GC retention times of the purified natural (4E)-dehydrocitrals were identical with those of synthetic (2E,4E)-3,7-dimethyl-2,4,6-octatrienal and (2Z,4E)-3,7-dimethyl-2,4,6-octatrienal. The geometry at the 2-C position of both synthetic (4E)-dehydrocitrals was confirmed by NOESY analyses. This is the first identification of (4E)-dehydrocitrals from the animal kingdom. (+info)
Androlaelaps marmosops (Acari: Laelapidae), a new species associated with the mouse opossum, Marmosops incanus (Lund, 1840) in the Atlantic forest of Rio De Janeiro State, Brazil.
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Androlaelaps marmosops, a new species of laelapid mite, is described from the pelage of the mouse opossum, Marmosops incanus (Lund, 1840) (Mammalia: Didelphidae), in two areas of Atlantic Forest of Rio de Janeiro State. Measurements and illustrations are included for females only. (+info)
Diarrhea and acaroid mites: a clinical study.
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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 (chi(2)=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. (+info)
Simple synthesis of mite pheromone beta-acaridial and its analogs in the secretion of Caloglyphus polyphyllae (Acari: Acaridae).
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A simple synthesis of beta-acaridial [(E)-1], the active principle of the sex, alarm and aggregation pheromone among astigmatid mites, was achieved in 5 steps from 1,2,4-butanetriol 2 in a 19% overall yield. Its analog, beta-acariolal 8, was also prepared in a 63% yield by oxidation of the intermediate, beta-acaridiol [(E)-7], with pyridinium dichromate (PDC). This synthetic route also gave beta-(Z)-acaridiol [(Z)-7] by using a Z-selective base in the Wittig reaction. (Z)-7 was oxidized to give a new monoterpene, beta-(Z)-acaridial [(Z)-1], which was detected as a trace component in the secretion of Caloglyphus polyphyllae, together with 8. (+info)