Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| [a challenge for the public health system in brazil: dengue control]. | this article presents a critical analysis of the traditional strategy used to control aedes aegypti using "health surveillance patrols", with periodic visits to all urban buildings. the strategy is not viable and/or is administratively unfeasible at present, since it has been proposed since the 1980s but has not been implemented. brazilian health reform prioritized the expansion of coverage for basic health services, and not measures to control specific diseases. a. aegypti, which was reintroduc ... | 2003 | 12700811 |
| mice genetically deficient in immunoglobulin e are more permissive hosts than wild-type mice to a primary, but not secondary, infection with the filarial nematode brugia malayi. | primary and secondary murine and human infections with brugia malayi are characterized by substantial increases in levels of immunoglobulin e (ige). to investigate whether this is necessary for worm clearance, ige(-/-) mice were subjected to primary- and secondary-infection protocols. following a primary infection, ige(-/-) mice displayed a profound deficit in their ability to clear an intraperitoneal injection of l3 infective-stage larvae in comparison to wild-type counterparts and maintained s ... | 2003 | 12704117 |
| isolation and expression of a sterol carrier protein-2 gene from the yellow fever mosquito, aedes aegypti. | trafficking of cholesterol in insects is a very important process due to the fact that insects depend on dietary cholesterol to fulfil their physiological needs. we identified a putative mosquito sterol carrier protein-2 (scp-2) cdna from fourth instar subtracted cdna library. the aescp-2 protein has high degree homology in the sterol transfer domain to both rat and human scp-2. transcripts of aescp-2 in fourth instars were detected strongly in the midgut, and weakly in the head and hindgut. in ... | 2003 | 12542635 |
| interaction of insect trypanosomatids with mosquitoes, sand fly and the respective insect cell lines. | interaction experiments between hematophagous insects and monoxenous trypanosomatids have become relevant, once cases of human infection involving these protozoa have been reported. moreover, investigations related to the interaction of insects with trypanosomatids that harbour an endosymbiotic bacterium and thereby lack the paraflagellar rod structure are important to elucidate the role of this structure in the adhesion process. in this work, we compared the interaction of endosymbiont-bearing ... | 2003 | 13129523 |
| efficacy of a new formulation of bacillus thuringiensis var israelensis (bti) in laboratory and field conditions of kumaun foothills of uttaranchal, india. | efficacy of a new bti formulation was tested in the laboratory and small scale field trials against mosquito larvae were carried out from march to june, 2001 in different breeding habitats of kumaun foothill region of nainital and udham singh nagar districts, uttaranchal state, india. laboratory tests revealed increased efficacy against culex quinquefasciatus (lc50 = 0.035 mg/l) followed by aedes aegypti (lc50 = 0.0628 mg/l), an. culicifacies sp a (lc50 = 0.184mg/l) and an. stephensi (lc50 - 0.2 ... | 2003 | 15909759 |
| enhanced esterase activity in salivary gland and midgut of aedes aegypti mosquito infected with dengue-2 virus. | mosquitoes were infected by intrathoracic inoculation. about 95% head squashes were positive for dengue virus antigen on the 15th post infection day (pid). esterase activity was determined in the homogenates prepared from the salivary glands and midguts on different pids of dengue virus inoculated and control mosquitoes showed that it was consistently higher in the virus-infected batches. | 2003 | 15267144 |
| ovicidal and larvicidal activity against aedes aegypti and anopheles gambiae complex mosquitoes of essential oils extracted from three spontaneous plants of burkina faso. | essential oils extracted from dried leaves of three spontaneous plants naturally growing in burkina faso, i.e. cymbopogon proximus, lippia multiflora and ocimum canum, exhibited larvicidal activity by the who standard protocol against 3rd and 4th instar f1-larvae of field-collected mosquitoes vectors of human disease, namely aedes aegypti and members of the anopheles gambiae complex, an. arabiensis and an. gambiae. the median lethal concentration (lc50) for ae. aegypti and an. gambiae s.l. larva ... | 2003 | 15270540 |
| biolarvicides in vector control: challenges and prospects. | biolarvicides, based on mosquitocidal toxins of certain strains of bacillus sphaericus and bacillus thuringiensis var israelensis h-14 (bti) are highly effective against mosquito larvae at very low doses and safe to other non-target organisms. during past two decades various biolarvicide formulations produced in india and abroad have been tested at malaria research centre and some formulations have undergone large-scale operational trials. biolarvicide formulations of b. sphaericus are useful in ... | 2003 | 15119068 |
| variation over space and time of aedes aegypti in phnom penh (cambodia): genetic structure and oral susceptibility to a dengue virus. | we studied spatial and temporal variation in 20-23 aedes aegypti samples collected in phnom penh and its suburbs to estimate the population genetic structure using allozymes and the susceptibility to a dengue-2 virus. based on seven allozyme systems, we detected low levels of genetic exchanges (i.e. high, significant f(st) values) between populations collected in the city centre, and different patterns of genetic structure for samples collected in the suburbs, depending on the type of environmen ... | 2003 | 15134196 |
| intraspecific dna variation in nuclear genes of the mosquito aedes aegypti. | single nucleotide polymorphisms (snps) are an abundant source of genetic variation among individual organisms. to assess the usefulness of snps for genome analysis in the yellow fever mosquito, aedes aegypti, we sequenced 25 nuclear genes in each of three strains and analysed nucleotide diversity. the average frequency of nucleotide variation was 12 snps per kilobase, indicating that nucleotide variation in ae. aegypti is similar to that in other organisms, including drosophila and the malaria v ... | 2003 | 14986924 |
| [levels of resistance to insecticides and their mechanisms in 2 strains of aedes aegypti from panama]. | the levels of susceptibility and/or resistance to insecticides in larvae and adults of aedes aegypti from 2 localities of panama (rio abajo and victoriano lorenzo) were determined. among larvae, it was found resistance to methyl- pyrimifos in both localities; however, they were susceptible to the rest of the organophosphate insecticides (temephos, malathion, fenthion fenitrothion and clorpirifos) and to pyrethroids (deltamethrin, lambda-cyhalothrin, cypermethrin and cyfluthrin. in the trials car ... | 2003 | 15849925 |
| [lethal effect of cuban myrtaceae on aedes aegypti (diptera cuilicidae)]. | the biological activity of the essential foliar oils from 2 cuban endemic myrtaceae: eugenia melanadenia and psidium rotundatum on a. aegypti larvae was evaluated for the first time at the laboratory level. the probit-log analysis of the results showed the larvicidal effect of both oils with values of cl50 = 0.0085% and cl95 = 0.0104% for e. melanadenia and cl50 = 0.0063% and cl95 = 0.0071% for o. rotundatum. besides, the diagnostic concentration for both essential oils are given and the possibl ... | 2003 | 15849965 |
| [cross resistance to pyrethroids in aedes aegypti from cuba induced by the selection with organophosphate malathion]. | a strain from aedes aegypti (l) collected in the municipality of santiago de cuba with low levels of resistance to malathion (1.79x) was subjected to selection pressure aimed at evaluating the evolution of the resistance to this organophosphate and its usefulness for control. after 5 generations of selection (san-f5) with malathion, it was not possible to increase the resistance and it was obtained a value of resistance factor (fr50) of 2.22x. none or little cross resistance to the following org ... | 2003 | 15849966 |
| a microfluorometric method for quantifying rna and dna in terrestrial insects. | evidence is accumulating for a mechanistic linkage between body phosphorus content and growth and reproduction of individual organisms, due in part to variation in allocation of resources to ribosomal rna. testing this connection requires reliable methods of quantifying the nucleic acid content of individual organisms. although methods for quantifying nucleic acids are available for a wide array of organisms, adaptation of such methods for study of insects has been neglected. sensitive stains an ... | 2003 | 15841218 |
| practical uses for ecdysteroids in mammals including humans: an update. | ecdysteroids are widely used as inducers for gene-switch systems based on insect ecdysteroid receptors and genes of interest placed under the control of ecdysteroid-response elements. we review here these systems, which are currently mainly used in vitro with cultured cells in order to analyse the role of a wide array of genes, but which are expected to represent the basis for future gene therapy strategies. such developments raise several questions, which are addressed in detail. first, the met ... | 2003 | 15844229 |
| [abundance indices of larvae and pupae of aedes aegypti (diptera: culicidae) in córdoba city]. | in 1995, aedes aegypti, vector of the flavivirus dengue and yellow fever, reached the province. therefore, it is necessary to quantify the vector abundance in order to determine the level of risk and to evaluate the prevention and control actions implemented. | 2003 | 16724440 |
| use of subtracted libraries and macroarray to isolate developmentally specific genes from the mosquito, aedes aegypti. | subtracted cdna libraries were screened with cdna macroarrays to isolate larval and pupal stage-specific genes from aedes aegypti. of 103 partial cdnas sequenced from the 4th instar subtracted cdna library, 62 have counterpart genes in other organisms while 41 of them have no significant similarity to any known genes. sequences of 116 partial cdna clones from the pupal subtracted library revealed that 57 belong to unknown genes and 59 have homologous genes in other organisms. results of cdna mac ... | 2002 | 12429127 |
| presence of chitinase and beta-n-acetylglucosaminidase in the aedes aegypti. a chitinolytic system involving peritrophic matrix formation and degradation. | measurement of the hydrolysis of specific fluorogenic substrates by spectrophotometry as well as the substrate activity-sds-page gel analysis of the chitinolytic activity in aedes aegypti guts showed that both chitinase and beta-n-acetylglucosaminidase are present and physiologically active. both enzymes were present even in guts from unfed insects, but the activities increased rapidly after feeding on blood or an artificial protein-free diet. chitinase activity was predominantly of the 'endo'-t ... | 2002 | 12429124 |
| repellent activity of constituents identified in foeniculum vulgare fruit against aedes aegypti (diptera: culicidae). | the repellent activity of materials derived from the methanol extract of fruits from foeniculum vulgareagainst hungry aedes aegypti females was examined using skin and patch tests and compared with that of the commercial n,n-diethyl-m-toluamide (deet) and (z)-9-octadecenoic acid. the biologically active constituents of the foeniculum fruits were characterized as (+)-fenchone and (e)-9-octadecenoic acid by spectroscopic analyses. responses varied according to compound, dose, and exposure time. in ... | 2002 | 12428949 |
| cloning and tissue distribution of two na+/h+ exchangers from the malpighian tubules of aedes aegypti. | a na(+)/h(+) exchanger (nhe) on the apical membrane of mosquito malpighian tubule (mt) cells is believed to participate in the blood-feeding mosquito's vital secretion of na(+) and fluid. this study presents the molecular cloning, primary structure, and tissue distribution of two cdnas encoding aedes aegypti mosquito mt nhes. the cdna sequences were obtained from mosquito mt total rna using reverse transcription-polymerase chain reaction (rt-pcr) and 5' and 3' rapid amplification of cdna ends (r ... | 2002 | 12386840 |
| operational note indoor low-volume spray trials: handheld equipment evaluation. | four handheld aerosol-mist generators and 1 thermal fog generator were evaluated initially for their ability to deliver low flow rates (< or = 5 ml/min) of resmethrin insecticide. two generators, the london fog eliminator and clarke pl, were then selected from that group to conduct a treatment of a block of 16 residences (4 x 4 grid) vs. direct treatment of individual residences to determine the most efficacious method of treating a group of small dwellings or a village. data are presented on dr ... | 2002 | 12322948 |
| effectiveness and residual activity comparison of granular formulations of insect growth regulators pyriproxyfen and s-methoprene against florida mosquitoes in laboratory and outdoor conditions. | effectiveness and residual activity tests of granular formulations of 2 insect growth regulators (igrs), s-methoprene and pyriproxyfen, against laboratory-reared larvae of 5 colonized mosquitoes, aedes aegypti, aedes albopictus, aedes taeniorhynchus, anopheles quadrimaculatus, and culex nigripalpus, were conducted in the laboratory and outdoors in plastic tubs. culex quinquefasciatus was exposed to these two igrs in the laboratory only. each igr formulation was applied at 0.02 and 0.05 ppm activ ... | 2002 | 12322941 |
| mosquito vector control and biology in latin america--a twelfth symposium. denver, colorado, february 2002. summaries. | the 12th annual latin american symposium presented by the american mosquito control association (amca) was held as part of the 68th annual meeting in denver, co, in february 2002. the principal objective, as for the previous 11 symposia, was to promote participation in the amca by vector control specialists, public health workers, and academicians from latin america. this publication includes summaries of 35 presentations that were given orally in spanish or presented as posters by participants ... | 2002 | 12322934 |
| cloning and sequence analysis of mosquito defensin genes. | to clone the defensin genes from the chinese main mosquito vectors and conduct sequnce analysis. | 2002 | 12297467 |
| molecular biology of mosquito vitellogenesis: from basic studies to genetic engineering of antipathogen immunity. | elucidation of molecular mechanisms underlying stage- and tissue-specific expression of genes activated by a blood meal is of great importance for current efforts directed towards utilizing molecular genetics to develop novel strategies of mosquito and pathogen control. regulatory regions of such genes can be used to express anti-pathogen effector molecules in engineered vectors in a precise temporal and spatial manner, designed to maximally affect a pathogen. the fat body is a particularly impo ... | 2002 | 12225918 |
| toward a description of the sialome of the adult female mosquito aedes aegypti. | to describe the set of mrna and protein expressed in the salivary glands (sialome) of aedes aegypti mosquitoes, we randomly sequenced a full-length cdna library of this insect and performed edman degradation of pvdf-transferred protein bands from salivary homogenates. we found 238 cdna clusters which contained those coding for 10 of the 11 proteins found by aminoterminal degradation. all six previously described salivary proteins were found in this library. full-length sequences of 32 novel cdna ... | 2002 | 12213246 |
| ribonucleotide reductase subunits from the yellow fever mosquito, aedes aegypti: cloning and expression. | ribonucleotide reductase catalyses the de novo synthesis of deoxyribonucleotides. class i reductases use an iron center to generate a tyrosyl free radical that can initiate formation of the deoxyribonucleotide. these reductases are alpha 2 beta 2 holoenzymes, and the subunits are denoted as r1 and r2. r1 contains the allosteric binding site and the active site, whereas r2 contains a binuclear iron center that initiates formation of the tyrosyl radical. we have cloned and sequenced the cdnas enco ... | 2002 | 12213240 |
| the chemical characterization of the epicuticular hydrocarbons of aedes aegypti (diptera: culicidae). | the chemical characterization of the hydrocarbon fraction of the epicuticular lipids of the vector mosquito aedes aegypti (linnaeus) was performed using gas chromatography (gc) and gas chromatography-electron impact mass spectrometry (gc-ms). seventy eight compounds were detected in purified hexane extracts and of these, 42 hydrocarbons were identified and several of the remaining compounds were partially characterized. the hydrocarbon classes present were n-alkanes, monomethylalkanes, dimethyla ... | 2002 | 12191436 |
| neuropeptide f and its expression in the yellow fever mosquito, aedes aegypti. | a neuropeptide f (npf) was isolated from an extract of adult aedes aegypti mosquitoes based on its immunoreactivity in a radioimmunoassay for drosophila npf. after sequencing the peptide, cdnas encoding the npf were identified from head and midgut. these cdnas encode a prepropeptide containing a 36 amino acid peptide with an amidated carboxyl terminus, and its sequence shows it to be a member of the neuropeptide f/y superfamily. immunocytochemistry and northern blots confirmed that both the brai ... | 2002 | 12182937 |
| leucokinin activates ca(2+)-dependent signal pathway in principal cells of aedes aegypti malpighian tubules. | the role of ca(2+) in mediating the diuretic effects of leucokinin-viii was studied in isolated perfused malpighian tubules of the yellow fever mosquito, aedes aegypti. peritubular leucokinin-viii (1 microm) decreased the transepithelial resistance from 11.2 to 2.6 komega. cm, lowered the transepithelial voltage from 42.8 to 2.7 mv, and increased transepithelial cl(-) diffusion potentials 5.1-fold. in principal cells of the tubules, leucokinin-viii decreased the fractional resistance of the baso ... | 2002 | 12167601 |
| linkage map organization of expressed sequence tags and sequence tagged sites in the mosquito, aedes aegypti. | a composite genetic linkage map for the yellow fever mosquito aedes aegypti was constructed based on restriction fragment length polymorphism (rflp), single nucleotide polymorphism (snp) and single strand conformation polymorphism (sscp) markers. the map consists of 146 marker loci distributed across 205 cm, and includes several morphological mutant marker loci. most of the genetic markers are derived from random cdnas or ae. aegypti genes of known function. a number of markers are derived from ... | 2002 | 12144703 |
| does temperature affect the outcome of larval competition between aedes aegypti and aedes albopictus? | the superior larval competitive ability of aedes albopictus has been proposed to explain the recent displacement of aedes aegyptiby the former species inparts of the southeastern u.s. ae. aegypti persists, however, in sympatry with ae. albopictus in urban areas of southern louisiana, florida, and texas, and the impact of larval competition between these species has not been investigated at higher temperatures that may be characteristic of these urban environments. we compared growth and survivor ... | 2002 | 12125878 |
| evaluation of various models of propane-powered mosquito traps. | large cage and field studies were conducted to determine the efficacy of various models of propane-powered mosquito traps. these traps utilized counterflow technology in conjunction with catalytic combustion to produce attractants (carbon dioxide, water vapor, and heat) and a thermoelectric generator that converted excess heat into electricity for stand-alone operation. the cage studies showed that large numbers of aedes aegypti and ochlerotatus taeniorhynchus were captured and that each progres ... | 2002 | 12125861 |
| an ecological survey of dengue vector mosquitos in central lao pdr. | an ecological survey of dengue vector mosquitos was carried out in june 2000 in central lao pdr. two areas in khammouane province, nongbok and thakhek, were selected for the survey. of the 7 mosquito species identified, aedes aegypti was dominant in both study areas. the container index for ae. aegypti in nongbok was 51.8% and was significantly higher than that of thakhek (40.2%); moreover, significant differences between the study areas were found with records to containers and to the condition ... | 2002 | 12118462 |
| a genetic correlation between age at pupation and melanization immune response of the yellow fever mosquito aedes aegypti. | to investigate the evolutionary cost of an immune response, we selected six lines of the mosquito aedes aegypti for earlier or later pupation and measured the extent to which this selection procedure changed the mosquito's ability to encapsulate and melanize a negatively charged sephadex bead. after 10 generations of selection, the age at pupation in the two selection regimes differed by about 0.7 days, accompanied by an increase of wing length of the mosquitoes selected for late pupation. among ... | 2002 | 12093022 |
| mouthparts of male aedes (stegomyia) mosquitoes. | mouthparts of adult males of 17 strains of 8 species from the subgenus stegomyia of the genus aedes, including 5 strains of aedes aegypti and 6 strains of aedes albopictus, were examined. lengths of maxillae, mandibles, maxillary palpi, and proboscises were measured under light microscopy and their detailed structures were examined by scanning electron microscopy. lengths were presented as ratios to proboscis lengths. in contrast to previous reports, mandibles were found in all 5 strains of male ... | 2002 | 12083358 |
| point source inoculation of mesocyclops (copepoda: cyclopidae) gives widespread control of ochlerotatus and aedes (diptera: culicidae) immatures in service manholes and pits in north queensland, australia. | this study details the novel application of predacious copepods, genus mesocyclops, for control of ochlerotatus tremulus (theobald) group and aedes aegypti (l.) mosquito larvae in subterranean habitats in north queensland, australia. during june 1997, 50 mesocyclops sp. 1 were inoculated into one service manhole in south townsville. wet season rainfall and flooding in both 1998 and 2000 was responsible for the dispersal of copepods via the underground pipe system to 29 of 35 manholes over an are ... | 2002 | 12061442 |
| a piperidine amide extracted from piper longum l. fruit shows activity against aedes aegypti mosquito larvae. | mosquito larvicidal activity of piper longum fruit-derived materials against the fourth-instar larvae of aedes aegypti was examined. a crude methanol extract of p. longum fruits was found to be active against the larvae, and the hexane fraction of the methanol extract showed a strong larvicidal activity of 100% mortality. the biologically active component of p. longum fruits was characterized as pipernonaline by spectroscopic analyses. the lc(50) value of pipernonaline was 0.25 mg/l. the toxicit ... | 2002 | 12059157 |
| neuroendocrine modulation of olfactory sensory neuron signal reception via axo-dendritic synapses in the antennae of the mosquito, aedes aegypti. | an ultrastructural study of the antennae of the yellow fever mosquito, aedes aegypti, revealed that as in the salt marsh mosquito, culex salinarius, the first flagellar segment of both sexes of a. aegypti contain neuroendocrine cells. these cells not only extend an axon via the antennal nerve to the antennal lobe of the deutocerebrum, but project collaterals to the periphery of the antennae, where they modulate the antennal sensory neurons by forming synapses with the dendrites of these afferent ... | 2002 | 12059042 |
| derris (lonchocarpus) urucu (leguminosae) extract modifies the peritrophic matrix structure of aedes aegypti (diptera:culicidae). | aqueous suspension of ethanol extracts of derris (lonchocarpus) urucu (leguminosae), collected in the state of amazonas, brazil, were tested for larvicidal activity against the mosquito aedes aegypti (diptera:culicidae). the aim of this study was to observe the alterations of peritrophic matrix in ae. aegypti larvae treated with an aqueous suspension of d. urucu extract. different concentrations of d. urucu root extract were tested against fourth instar larvae. one hundred percent mortality was ... | 2002 | 12051197 |
| variation of the oviposition preferences of aedes aegypti in function of substratum and humidity. | two aedes aegypti (l.) populations were studied in the laboratory regarding the preference for three types of breeding sites, i.e., flasks containing only water, flasks with a plant and flasks with a stick. each of these breeding units was placed in one cage and the choice of the oviposition sites was determined for individual females and three females per experimental unit at two humidity levels. preference for ovipositing on the water surface was observed and varied according to experimental u ... | 2002 | 12048575 |
| formulation of an effective mosquito-repellent topical product from lemongrass oil. | ointment and cream formulations of lemongrass oil in different classes of base and the oil in liquid paraffin solution have been evaluated for mosquito repellency in a topical application. mosquito repellency was tested by determining the bite-deterrence of product samples applied on an experimental bird's skin against a 2-day starved culture of aedes aegypti l. mosquitoes. the 1%v/v solution and 15%v/w cream and ointment preparations of the oil exhibited > or =50% repellency lasting 2-3 h, whic ... | 2002 | 12046869 |
| [climate and the superimposed distribution of aedes aegypti and aedes albopictus on infestation of são paulo state, brazil]. | to study the influence of climatic factors and superimposed distribution of aedes aegypti and aedes albopictus populations on their geographic dispersal in the state of são paulo. | 2002 | 12045797 |
| characterization of hemocytes from the yellow fever mosquito, aedes aegypti. | mosquitoes are the most important arthropod disease vectors, transmitting a broad range of pathogens that cause diseases such as malaria, lymphatic filariasis, and yellow fever. mosquitoes and other insects are able to mount powerful cellular and humoral immune responses against invading pathogens. to date, most studies have concentrated on the humoral response. in the current study we describe the hemocytes (blood cells) of the yellow fever mosquito, aedes aegypti, by means of morphology, lecti ... | 2002 | 12029490 |
| comparison of cetirizine, ebastine and loratadine in the treatment of immediate mosquito-bite allergy. | people frequently experience whealing and delayed papules from mosquito bites. whealing is mediated by antisaliva immunoglobulin (ig)e antibodies and histamine. cetirizine, ebastine and loratadine have earlier shown effects on mosquito-bite reactions but no comparative studies exist. | 2002 | 12028119 |
| [susceptibility to the infection of anopheles nuneztovari gabaldón and aedes aegypti l with romanomermis iyengari welch (rhabditida: mermitidae)]. | a laboratory-based study was performed in order to assess the infestation capacity of the mosquito parasite nematode romanomermis iyengari welch, on anopheles nuneztovari gabaldón and aedes aegypti l. for each mosquito species, nine hundred (900) i to iii instars larvae were taken. these larvae were infested with pre-parasitic larvae of r. iyengari in proportions of 5:1 and 10:1. the infestation averages obtained were 3.9 and 6.7 for anopheles nuneztovari, and 1.9 and 4.7 for aedes aegypti respe ... | 2002 | 12520998 |
| field evaluation of cypermethrin and cyfluthrin against dengue vectors in a housing estate in malaysia. | cynoff 25ulv (cypermethrin 25 g/l) and solfac ul015 (cyfluthrin 1.5% w/v) were evaluated against the sentinel sugar-fed adults and 4th-instar larvae of aedes aegypti in a housing estate endemic of dengue in malaysia. the impact of both pyrethroids on field populations of aedes albopictus and aedes aegypti larvae was monitored weekly using bottle containers. both cynoff 25ulv and solfac ul015 showed adulticidal effects and larvicidal effects. this field trial using cynoff 25ulv against dengue vec ... | 2002 | 12546459 |
| glucosamine:fructose-6-phosphate aminotransferase: gene characterization, chitin biosynthesis and peritrophic matrix formation in aedes aegypti. | glucosamine:fructose-6-phosphate aminotransferase (gfat) catalyses the formation of glucosamine 6-phosphate and is the first and rate-limiting enzyme of the hexosamine biosynthetic pathway. the final product of the hexosamine pathway, udp-n-acetyl glucosamine, is an active precursor of numerous macromolecules containing amino sugars, including chitin in fungi and arthropods. chitin is one of the essential components of insect cuticle and peritrophic matrix. the peritrophic matrix is produced in ... | 2002 | 12000639 |
| survey of aedes aegypti eggs in and around homes in tucson, arizona. | the abundance and location of eggs of aedes aegypti were evaluated through inspection of 24 tucson homes during the winter of 1998-99 to assess the potential of the mosquitoes to overwinter in this area. eggs were found either indoors or outdoors in 46% of residences surveyed. after immersion in water, about 23% of eggs found indoors hatched, and about 5% of eggs found outdoors hatched. | 2002 | 11998933 |
| two isoforms of the early e74 gene, an ets transcription factor homologue, are implicated in the ecdysteroid hierarchy governing vitellogenesis of the mosquito, aedes aegypti. | in the anautogenous mosquito, aedes aegypti, vitellogenesis is under the strict control of 20-hydroxyecdysone (20e), which is produced via a blood meal-activated hormonal cascade. several genes of the ecdysteroid-regulatory hierarchy are conserved between vitellogenesis in mosquitoes and metamorphosis in drosophila. we report characterization of two isoforms of the mosquito early e74 gene (aae74), which have a common c-terminal ets dna-binding domain and unique n-termini. they exhibited a high l ... | 2002 | 11997188 |
| development and applications of transgenesis in the yellow fever mosquito, aedes aegypti. | transgenesis technology has been developed for the yellow fever mosquito, aedes aegypti. successful integration of exogenous dna into the germline of this mosquito has been achieved with the class ii transposable elements, hermes, mariner and piggybac. a number of marker genes, including the cinnabar(+) gene of drosophila melanogaster, and fluorescent protein genes, can be used to monitor the insertion of these elements. the availability of multiple elements and marker genes provides a powerful ... | 2002 | 11985858 |
| effect of the synergist, piperonyl butoxide, on the development of deltamethrin resistance in yellow fever mosquito, aedes aegypti l. (diptera: culicidae). | the larvae and adults of aedes aegypti were tested for the potential to develop resistance to the synthetic pyrethroid, deltamethrin, alone or a combination of deltamethrin with the synergist, piperonyl butoxide (pbo). although continuous larval selection for 40 generations resulted in 703-fold resistance, the resistance ratio in the adults was only 1.3. similarly, adult selections with deltamethrin showed a resistance ratio of less than four after 40 generations, indicating differential respons ... | 2002 | 11948970 |
| investigation of the larvicidal activity of pothomorphe peltata and isolation of the active constituent. | the insecticidal activity of the leaves of pothomorphe peltata (piperaceae) was evaluated on aedes aegypti larvae. the active methanol extract was subjected to a bioactivity-directed fractionation, monitored by the larvicidal assay, and led to the isolation of a catechol derivative, 4-nerolidylcatechol. this compound was quite potent against aedes aegypti larvae (lc(50) = 9.1 microg/ml). | 2002 | 11933144 |
| winter intervention against aedes aegypti (diptera: culicidae) larvae in subterranean habitats slows surface recolonization in summer. | at semiarid charters towers, north queensland, australia, the importance of aedes aegypti (l.) in wells was assessed in relation to the colonization of surface habitats during the wet season. from april to july 1999, 10 wells (five positive for ae. aegypti) were monitored to assess their status and larvae population numbers therein. all surface containers located within a 100 m radius of each well were removed, treated with s-methoprene or sealed to prevent the utilization of these containers by ... | 2002 | 11931036 |
| characterization of the aeahp gene and its expression in the mosquito aedes aegypti (diptera: culicidae). | the sequence and tissue expression of the gene encoding a peptide hormone aea-hp-i, known to inhibit host-seeking behavior, has been characterized for the yellowfever mosquito, aedes aegypti (l.). the open reading frame reveals a prepropeptide that would be processed into three identical peptides. the gene contains four short introns and exists as a single genomic copy. transcripts of the gene were present in the brain, terminal ganglion, and midgut of adults, and in females, its expression prof ... | 2002 | 11931033 |
| carbonic anhydrase in the midgut of larval aedes aegypti: cloning, localization and inhibition. | the larval mosquito midgut exhibits one of the highest ph values known in a biological system. while the ph inside the posterior midgut and gastric caeca ranges between 7.0 and 8.0, the ph inside the anterior midgut is close to 11.0. alkalization is likely to involve bicarbonate/carbonate ions. these ions are produced in vivo by the enzymatic action of carbonic anhydrase. the purpose of this study was to investigate the role of this enzyme in the alkalization mechanism, to establish its presence ... | 2002 | 11907049 |
| aedes aegypti peritrophic matrix and its interaction with heme during blood digestion. | a large amount of heme is produced upon digestion of red cell hemoglobin in the midgut of mosquitoes. the interaction between heme and the peritrophic matrix (pm) was studied in aedes aegypti. by light microscopy, the pm appeared as a light brownish layer between the intestinal epithelium and the alimentary bolus. this natural color can be attributed to the presence of heme bound to the matrix. in histochemical studies, a diffuse peroxidase activity of the heme molecules was clearly observed bet ... | 2002 | 11891128 |
| 3-hydroxykynurenine transaminase identity with alanine glyoxylate transaminase. a probable detoxification protein in aedes aegypti. | this study describes the functional characterization of a specific mosquito transaminase responsible for catalyzing the transamination of 3-hydroxykynurenine (3-hk) to xanthurenic acid (xa). the enzyme was purified from aedes aegypti larvae by ammonium sulfate fractionation, heat treatment, and various chromatographic techniques, plus non-denaturing electrophoresis. the purified transaminase has a relative molecular mass of 42,500 by sds-page. n-terminal and internal sequencing of the purified p ... | 2002 | 11880382 |
| midgut exopeptidase activities in aedes aegypti are induced by blood feeding. | midgut extracts from aedes aegypti females exhibited hydrolytic activities against synthetic substrates for carboxypeptidase a, carboxyopeptidase b and leucine-aminopeptidase. the three activities showed a broad ph optimum, with maximum activities at ph between 6.5 and 8.5. enzymatic activities were further characterized by testing the effects of a variety of protease inhibitors. captopril and 1-10-phenantroline inhibited the activities of carboxypeptidases a and b, while leuhistin, amastatin an ... | 2002 | 12770120 |
| membrane conductances of principal cells in malpighian tubules of aedes aegypti. | two-electrode voltage clamp (tevc) methods were used to explore conductive transport pathways in principal cells, the dominant cell type in malpighian tubules of the yellow fever mosquito. the basolateral membrane of principal cells had a voltage (v(bl)) of -85.1 mv in 49 principal cells under control conditions. measures of the input resistance r(pc) together with membrane fractional resistance yielded estimates of the conductance of the basolateral membrane (g(bl) = 1.48 &mgr;s) and the apical ... | 2002 | 12770112 |
| lipid metabolism during sequential gonotrophic cycles in large and small female aedes aegypti. | the lipid metabolism was investigated during six gonotrophic cycles of aedes aegypti. females of constant body size were analyzed for their total lipid content: large females with a body size of 41.06 (wing length cubed) and small females with 15.63. their lipid contents at eclosion were compared to lipid values after two days of sugar-feeding, shortly before a blood meal, after oviposition, of their total egg batches, and again before the next blood meal, with intermittent access to sugar for t ... | 2002 | 12770082 |
| a ribosome-free extract from cultured cells improves recovery of polysomes from the mosquito fat body: analysis of vitellogenin and ribosomal protein rpl34 gene expression. | we have examined the association of ribosomal protein rpl34 mrna with polysomes in aedes albopictus c7-10 cells in culture using a simple, two-step sucrose gradient. in growing cells, 40-50% of the ribosomes were engaged on polysomes. this proportion could be increased to 80% when metabolism was stimulated by refeeding the cells with fresh medium. conversely, ribosomes shifted off polysomes when cells were starved with phosphate-buffered saline or cell lysates were treated with puromycin. when s ... | 2002 | 12770046 |
| a single point mutation in ecdysone receptor leads to increased ligand specificity: implications for gene switch applications. | the ecdysone receptor (ecr), a member of the nuclear receptor superfamily, plays an important role in regulating development and reproduction in insects. the ecr binds to ecdysteroids and regulates transcription of genes that contain ecdysone response elements. the ecr has been used to develop inducible gene switches for efficient regulation of foreign genes in applications such as gene therapy, protein production, and functional genomics. an ecr [choristoneura fumiferana ecr (cfecr)] homology m ... | 2002 | 12411578 |
| aedes aegypti ferritin heavy chain homologue: feeding of iron or blood influences message levels, lengths and subunit abundance. | secreted ferritin in the mosquito, aedes aegypti, has several subunits that are the products of at least two genes, one encoding a homologue of the vertebrate heavy chain (hch) and the other the light chain homologue (lch). here we report the developmental and organ specific pattern of expression of the ferritin hch messages and of both subunit types in control sugar-fed mosquitoes, in those exposed to high levels of dietary iron, and after blood feeding. when northern blots were probed with a h ... | 2002 | 15455041 |
| plant growth regulatory effect and insecticidal activity of the extracts of the tree of heaven (ailanthus altissima l.). | there is an urgent need to explore and utilize naturally occurring products for combating harmful agricultural and public health pests. secondary metabolites in the leaves of the tree of heaven, ailanthus altissima l. have been reported to be herbicidal and insecticidal. the mode of action, however, of the active compounds in a. altissima are not understood. in this paper, we report the chemical characteristics of the herbicidal and insecticidal components in this tree, and will discuss the effe ... | 2002 | 11860616 |
| effects of juvenile hormone and ecdysone on the timing of vitellogenin appearance in hemolymph of queen and worker pupae of apis mellifera. | the caste-specific regulation of vitellogenin synthesis in the honeybee represents a problem with many yet unresolved details. we carried out experiments to determine when levels of vitellogenin are first detected in hemolymph of female castes of apis mellifera, and whether juvenile hormone and ecdysteroids modulate this process. vitellogenin levels were measured in hemolymph using immunological techniques. we show that in both castes the appearance of vitellogenin in the hemolymph occurs during ... | 2002 | 15455035 |
| triacylglycerol-rich lipophorins are found in the dipteran infraorder culicomorpha, not just in mosquitoes. | lipophorin is the major hemolymph protein responsible for lipid transport between tissues of insects. lipophorins from several insect species in order diptera (the fruit fly drosophila melanogaster from the suborder brachycera, the mosquito aedes aegypti; the phantom midges chaoborus maximus and minimus; the black fly simulium vittatum; the crane fly nephrotoma abbreviata, all from the suborder nematocera) were isolated and characterized. all lipophorins consisted of two protein subunits of appr ... | 2002 | 15455049 |
| decreased survival of mosquito cells after stable transfection with a drosophila ecdysteroid response element: possible involvement of a 40 kda dna binding protein. | homologous transfection systems provide a useful tool for characterizing promoters and other regulatory elements from cloned genes. we have used cultured aedes albopictus c7-10 mosquito cells to evaluate expression of 20-hydroxyecdysone-inducible genes. although this cell line has previously been shown to synthesize components of the ecdysteroid receptor and ecdysone-inducible proteins, the well-characterized ecdysteroid response element (ecre) from the drosophilahsp27 promoter failed to confer ... | 2002 | 15455055 |
| structure-based analysis of the ultraspiracle protein and docking studies of putative ligands. | the ultraspiracle protein (usp) is the insect ortholog of the mammalian retinoid x receptor (rxr). fundamental questions concern the functional role of usp as the heterodimerization partner of insect nuclear receptors such as the ecdysone receptor. the crystallographic structures of the ligand binding domain of usps of heliothis virescens and drosophila melanogaster solved recently show that helix 12 is locked in an antagonist conformation raising the question whether usps could adopt an agonist ... | 2002 | 15455059 |
| outlook of dengue in malaysia: a century later. | dengue continues to be a major health threat to malaysia a century after its first reported outbreak in 1902. examination of the available outbreak data suggested that a major df/dhf outbreak occurred in malaysia in a cyclical pattern of approximately every 8 years. all four dengue virus serotypes are found co-circulating in malaysia, but after the first and only major outbreak involving den-4 in 1960's, only den-1, den-2 and den-3 were associated with df/dhf outbreaks. it is argued that perhaps ... | 2002 | 16329552 |
| laboratory evaluation of vectobac as against aedes aegypti in monterrey, nuevo león, mexico. | intensive use of the organophosphate insecticide malathion against adults and temephos against larvae of aedes aegypti in mexico over the past 30 years has led to problems requiring the use of new larvicides. toward this objective, bacillus thuringiensis var. israelensis (bti), a target-specific and environmentally safer control agent, was evaluated. laboratory bioassays were done to determine the susceptibility of 2nd- and 3rd-stage larvae of ae. aegypti to vectobac 12 as (aqueous suspension, 6 ... | 2002 | 12545970 |
| fast and slow blood-feeding durations of aedes aegypti mosquitoes in trinidad. | the duration of blood feeding by similar-sized aedes aegypti (l.) was determined under laboratory conditions in trinidad, west indies. ae. aegypti from the f0 generation contained individuals that fed quickly (106.2 seconds) as well as slowly (330.0 seconds). among the fast feeders (<2 min), the time taken for blood feeding during the first gonotrophic cycle was much shorter than that observed for the 2nd, 3rd and 4th gonotrophic cycles. in contrast, among the slow feeders the time taken was muc ... | 2002 | 12546453 |
| breeding habitats and larval indices of aedes aegypti (l) in residential areas of rajahmundry town, andhra pradesh. | entomological studies on relative prevalence and distribution of adults and immatures of aedes aegypti were conducted in rajahmundry town of andhra pradesh from december 1998 to november 1999. adults and immature stages of aedes aegypti were found in all the 22 localities viz; posh area (8), mixed area (8) and slum area (6) of the town. larval indices were found to be higher in slum areas as compared to mixed or posh areas of the town. however, the larval habitats were observed to be similar in ... | 2002 | 12718342 |
| evaluation of polymer-based granular formulations of bacillus thuringiensis israelensis against larval aedes aegypti in the laboratory. | a strategy to increase residual activity of bacillus thuringiensis serovar. israelensis (bti) extract through slow-release formulations and protection from solar radiation was studied. the median lethal concentration (lc50) and 90% lethal concentration (lc90) levels of laboratory-reared early 4th-stage larval aedes aegypti after exposure to bti extract were determined. formulations with 4 polymers and 1 solar protectant were prepared, and their shelf lives were evaluated for year-long storage at ... | 2002 | 12542194 |
| [aedes aegypti, vector of the dengue virus: spatio-temporal structure of its genetic variation]. | aedes aegypti is the main vector of dengue viruses. methods for limiting the spread of dengue outbreaks are currently based on vector control. estimates of population genetic organization and gene flow with respect to vector capacity have provided great insights into dengue epidemiology. in vietnam, dengue hemorrhagic fever was detected in the 1950's and becomes today the major problem of public health. among factors influencing dengue epidemiology, ecological disturbances have a direct impact o ... | 2002 | 12669664 |
| vector competence of brazilian aedes aegypti and ae. albopictus for a brazilian yellow fever virus isolate. | because the potential urban yellow fever (yf) mosquito vectors aedes aegypti and ae. albopictus are at historical highs in brazil, both in terms of density and geographical range, we assessed the risk of an urban yf epidemic in brazil. we evaluated and confirmed in a laboratory setting the vector competence of brazilian ae. aegypti for a currently circulating strain of yf virus, and investigated the potential for brazilian ae. albopictus to transmit yf. | 2002 | 12625133 |
| control of the aedes vectors of the dengue viruses and wuchereria bancrofti: the french polynesian experience. | in most of the 130 islands of french polynesia, the stenotopic mosquitoes aedes aegypti (the main local vector for the viruses causing dengue) and aedes polynesiensis (the main local vector of wuchereria bancrofti) share many breeding sites in water containers such as discarded cans, coconut shells, buckets and water-storage pots and drums. in addition to selective application of insecticides, non-polluting methods of controlling these mosquitoes have been evaluated during the last decade in two ... | 2002 | 12625924 |
| naturally exposed populations differ in their t1 and t2 responses to the circumsporozoite protein of plasmodium falciparum. | t-cell responses directed against the circumsporozoite protein (cs) of plasmodium falciparum can mediate protection against malaria. we determined the frequency of t cells reactive to different regions of the cs in the blood of donors naturally exposed to p. falciparum by examining t1 (gamma interferon [ifn-gamma] elispot assay), t2 (interleukin 4 [il-4] elispot assay), and proliferative t-cell responses. the proliferative responses were weak, which confirmed previous observations. the responses ... | 2002 | 11854234 |
| monoclonal antibody against the plasmodium falciparum chitinase, pfcht1, recognizes a malaria transmission-blocking epitope in plasmodium gallinaceum ookinetes unrelated to the chitinase pgcht1. | to initiate invasion of the mosquito midgut, plasmodium ookinetes secrete chitinases that are necessary to cross the chitin-containing peritrophic matrix en route to invading the epithelial cell surface. to investigate chitinases as potential immunological targets of blocking malaria parasite transmission to mosquitoes, a monoclonal antibody (mab) was identified that neutralized the enzymatic activity of the sole chitinase of plasmodium falciparum, pfcht1, identified to date. this mab, designate ... | 2002 | 11854247 |
| a theoretical approach to predicting the success of genetic manipulation of malaria mosquitoes in malaria control. | mosquitoes that have been genetically modified to better encapsulate the malaria parasite plasmodium falciparum are being considered as a possible tool in the control of malaria. hopes for this have been raised with the identification of genes involved in the encapsulation response and with advances in the tools required to transform mosquitoes. however, we have only very little understanding of the conditions that would allow such genes to spread in natural populations. | 2002 | 12057019 |
| interaction of 65- and 62-kd proteins from the apical membranes of the aedes aegypti larvae midgut epithelium with cry4b and cry11a endotoxins of bacillus thuringiensis. | a protein with the molecular weight of 65 kd is the only component of aedes aegypti larvae bbm capable to specifically bind mosquitocidal toxins cry4b and cry11a of bacillus thuringiensis. this protein lacks the leucine aminopeptidase activity which is characteristic for the toxin-binding proteins from the membranes of caterpillars. cry-toxins inactive against a. aegypti larvae either fail to bind to the 65-kd protein and to a putative product of its proteolysis with the molecular weight of 62 k ... | 2002 | 12059773 |
| mating alters the cuticular hydrocarbons of female anopheles gambiae sensu stricto and aedes aegypti (diptera: culicidae). | the cuticular hydrocarbons of female anopheles gambiae giles sensu stricto and aedes aegypti (l.) mosquitoes were analyzed before and after they mated. in an. gambiae, the proportions of the two cuticular hydrocarbon components, n-heneicosane and n-tricosane, were significantly reduced as the female aged and after it mated. there were no changes in the hydrocarbon composition of males after they mated. hydrocarbon extracts from mated and unmated an. gambiae females as well as those from males ca ... | 2002 | 12061454 |
| temporal genetic variation in aedes aegypti populations in ho chi minh city (vietnam). | aedes aegypti, the main vector of dengue viruses in asia, displays variation in population density over time. the larval habitats of this species being unevenly distributed and transient (depending on cycles of drought and flood), the forces generating temporal variation in gene frequencies in populations are studied. we sampled seven mosquito populations from ho chi minh city (vietnam) and its suburbs on five occasions between april 1999 and august 2000. we investigated genetic variation by stu ... | 2002 | 12080364 |
| completion of the sequence of the nuclear ribosomal dna subunit of simulium sanctipauli, with descriptions of the 18s, 28s genes and the igs. | we describe the igs-ets, 18s and 28s ribosomal gene sequences of simulium sanctipauli vajime & dunbar, a member of the s. damnosum theobald (diptera: simuliidae) complex of blackflies (diptera: simuliidae). these regions, together with the its-1, its-2 and 5.8s rdna presented elsewhere (accession number u36206), constitute the composite sequence of the entire rdna unit, making s. sanctipauli the second dipteran species of medical importance for which the entire rdna has been sequenced. despite t ... | 2002 | 12510891 |
| isoenzyme variation in aedes aegypti correlated with dirofilaria immitis infectability. | from the vero beach strain of the mosquito aedes (stegomyia) aegypti (l.) (diptera: culicidae), substrains were selected for susceptibility (ss) and refractoriness (rr) to the dog heartworm dirofilaria immitis (leidy) (filarioidea: onchocercidae). these two lines and their reciprocal f1 hybrids were analysed for genetic variation at 14 enzyme loci, using polyacrylamide gel electrophoresis. six of the enzyme loci showed variation (sample size 48 alleles/locus/line). three of these were monomorphi ... | 2002 | 12510895 |
| isoenzyme differentiation of aedes aegypti populations in french guiana. | population genetics of peri-domestic aedes aegypti (diptera: culicidae), vector of dengue and yellow fever, were investigated by gel electrophoresis of 10 enzyme loci in 14 samples of mosquito larvae collected in 1997-1998 from localities separated by distances of 3-275 km in french guiana. genetic differentiation between geographical populations was generally high (mean fst = +0.111, p < 10(-5)) even among seven sites <30 km apart (fst = +0.137, p < 0.05), but not positively correlated with dis ... | 2002 | 12510901 |
| host-specific cues cause differential attractiveness of kenyan men to the african malaria vector anopheles gambiae. | many studies have suggested that variability in the attractiveness of humans to host-seeking mosquitoes is caused by differences in the make-up of body emanations, and olfactory signals in particular. most investigations have either been laboratory-based, utilising odour obtained from sections of the body, or have been done in the field with sampling methods that do not discriminate between visual, physical and chemical cues of the host. accordingly, evidence for differential attractiveness base ... | 2002 | 12513703 |
| novel cost-effective method of screening soils for the presence of mosquito-pathogenic bacilli. | the aim was to simplify the cumbersome conventional process of isolating virulent bacilli, which involves isolating all bacilli strains from a source followed by screening for strains that are effective for bio-control of mosquito vectors. | 2002 | 12460424 |
| [main breeding-containers for aedes aegypti and associated culicids, argentina]. | breeding containers for aedes (stegomyia) aegypti were identified in two cities of chaco province (northeast argentina): presidencia roque saenz peña and machagai. all water-retaining recipients found in house backyards capable to retain water were classified according to their type and size, counted and checked. aedes aegypti and culex quinquefasciatus were the most frequently collected species, being also found cx. maxi, cx. saltanensis and ochlerotatus scapularis. tires and car batteries repr ... | 2002 | 12471389 |
| laboratory vector competence experiments with yellow fever virus and five south african mosquito species including aedes aegypti. | three domestic and peridomestic mosquito species, selected because their prevalence, distribution and ecology favoured them as potential urban vectors of yellow fever (yf) in south africa, were submitted to numerous tests for infectivity [measured as dose needed to infect 50% of the mosquitoes (mid50)], mainly with a kenyan strain (bc7914) of the virus. use of a nigerian virus strain (tvp1617) did not significantly alter infectivity. after artificial infective blood meals with titres of 7.0-8.0 ... | 2002 | 12474475 |
| [cytopathological effect of bacillus thuringiensis israelensis endotoxins on the intestines of aedes aegypti mosquito larvae]. | the dynamics of pathological changes in the intestine of aedes aegypti larvae under the influence of toxins cry11a and cry4b produced by bacillus thuringiensis israelensis was studied by means of electron microscope. most significant ultrastructure changes in the intestine of the second instar larvae were observed in the midgut. the cytoplasm of cells disintegrated, and elongated lacunae appeared. the number of microvilli decreased, or they disappeared in the result of destruction. the peritroph ... | 2002 | 12481602 |
| geographic genetic variation in populations of the dengue virus vector aedes aegypti. | isoenzyme variation was assessed in 79 mosquito samples of aedes aegypti, and susceptibility to a dengue 2 virus strain was evaluated in 83 samples. analysis of fst values, differentiation indexes, and geographic distances separating populations revealed that genetic differences between populations depended on the species' history of migration and colonization. three major clusters were identified: (1). the sylvan form, ae. ae. formosus, from west africa and some islands in the indian ocean; (2) ... | 2002 | 12486524 |
| evaluation of the residual effect of temephos on aedes aegypti (diptera, culicidae) larvae in artificial containers in manaus, amazonas state, brazil. | trial tests and container observations were conducted in households to verify the residual effect of temephos in manaus, amazonas state, brazil. three plastic buckets, three tin cans, and three tires filled with water from an artesian well and larvicide were used in the experiment, with twenty-five third-instar larvae, which remained exposed for 24h, followed by mortality readings. the same types of containers were selected from common households. collection and counts followed by chemical treat ... | 2002 | 12488878 |
| cross-resistance to pyrethroid and organophosphorus insecticides induced by selection with temephos in aedes aegypti (diptera: culicidae) from cuba. | a sample of aedes aegypti (l.) from santiago de cuba, cuba, with a high level of temephos resistance (19.58x at the 50% lethal concentration [lc50]), was subjected to temephos selection to evaluate the utility of this organophosphate insecticide for mosquito control. high resistance developed after six generations of selection (200.00x). little or no cross-resistance was observed to the organophosphates, malathion and fenitrothion, but high cross-resistance was observed for the pyrethroid deltam ... | 2002 | 12495187 |
| preadult stage parasites and multiple timed exposure to infective larvae are involved in development of limb edema in brugia malayi-infected indian leaf monkeys (presbytis entellus). | the pathogenesis of filarial limb edema is not known. the role of parasitological variables and parasite-mediated phenomena in the development of limb edema was investigated in the presbytis entellus-brugia malayi model. infection was initiated with subcutaneous inoculation of infective third-stage larvae (l(3)), and the animals were reexposed to different doses of l(3) at the prepatent, patent, and diminishing microfilaremia (0 to 5% of peak microfilaremia count) stages of infection. a large l( ... | 2002 | 12093695 |
| first outbreak of dengue hemorrhagic fever, bangladesh. | during the first countrywide outbreak of dengue hemorrhagic fever in bangladesh, we conducted surveillance for dengue at a hospital in dhaka. of 176 patients, primarily adults, found positive for dengue, 60.2% had dengue fever, 39.2% dengue hemorrhagic fever, and 0.6% dengue shock syndrome. the dengue virus 3 serotype was detected in eight patients. | 2002 | 12095447 |
| new enamine derivatives of lapachol and biological activity. | a convenient synthesis of the new enamine derivatives 2-(4-morpholinyl)-3-(3-methyl-2-butenyl)-1,4-naphthalenedione, 2-(1-piperidinyl)-3-(3-methyl-2-butenyl)-1,4-naphtalenedione and 2-(1-pyrrolidinyl)-3-(3-methyl-2-butenyl)-1,4-naphthalenedione was carried out from natural 2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthalenedione (lapachol) and morpholine, piperidine and pyrrolidine. the structures of the products were established mainly by nmr analysis, including 2d experiments. biological activiti ... | 2002 | 12098751 |
| insulin receptor expression during development and a reproductive cycle in the ovary of the mosquito aedes aegypti. | a key tyrosine kinase receptor regulates steroidogenesis during egg maturation in the mosquito aedes aegypti. this study examined expression patterns and phosphorylation states of the mosquito insulin receptor (mir) in ovaries during the previtellogenic stage and a reproductive cycle. little or no mir protein was present until 24 h after adult eclosion, when the mature mir appeared as a approximately 400-kda tetrameric protein composed of two 116-kda alpha-subunits and two 95-kda beta-subunits. ... | 2002 | 12107434 |
| isolation, characterization, and functional expression of kynurenine aminotransferase cdna from the yellow fever mosquito, aedes aegypti(1). | this study describes the molecular and biochemical characterization of kynurenine aminotransferase (kat) from aedes aegypti mosquitoes. through screening an a. aegypti larval cdna library, a 1695-bp full-length cdna clone with a 1434-bp open reading frame (orf) was isolated. its deduced amino acid sequence consists of 477 amino acid residues with a predicted molecular mass of 53,490 and the amino acid sequence shares 47 and 42% identity with kats from homo sapiens and rattus norvegicus, respecti ... | 2002 | 12110301 |
| the use of commercial saponin from quillaja saponaria bark as a natural larvicidal agent against aedes aegypti and culex pipiens. | the larvicidal activity of commercial bark saponin extract (sigma) from quillaja saponaria was studied on 3rd-4th instar larvae of aedes aegypti and culex pipiens (vectors for dengue fever and western nile virus, respectively). the larvae were exposed to serial concentrations (1000, 800, 500, 300, 100, 10, 1, 0.1 and 0.01 mg/l) of the extract for 1, 3, 5, 7 and 11 days. the results indicate that commercial bark saponin is toxic, causing 100% larval mortality in a. aegypti and c. pipiens after 1 ... | 2002 | 12127245 |