| [dengue prevention and control: a review of studies on knowledge, beliefs, and practices]. | this article aims to contribute to dengue control programs through a review of recent studies on knowledge, beliefs, and practices concerning dengue and dengue prevention. the results show that adequate knowledge of dengue and prevention methods are found in close association with high rates of domiciliary infestation by aedes aegypti. this suggests that traditional education strategies, although efficient in transmitting information, have failed to change population behavior. qualitative studie ... | 2004 | 15608846 |
| [susceptibility of aedes aegypti to temephos and cypermethrin insecticides, brazil]. | bioassays were performed in order to detect the susceptibility of aedes aegypti to the chemical insecticides temephos and cypermethrin. the results showed that this species is susceptible to temephos and presents resistance to cypermethrin. | 2004 | 15608903 |
| selection for virulent dengue viruses occurs in humans and mosquitoes. | dengue is the most common mosquito-borne viral disease in humans. the spread of both mosquito vectors and viruses has led to the resurgence of epidemic dengue fever (a self-limited flu-like syndrome) and the emergence of dengue hemorrhagic fever (severe dengue with bleeding abnormalities) in urban centers of the tropics. there are no animal or laboratory models of dengue disease; indirect evidence suggests that dengue viruses differ in virulence, including their pathogenicities for humans and ep ... | 2005 | 15613313 |
| age-associated mortality in immune challenged mosquitoes (aedes aegypti) correlates with a decrease in haemocyte numbers. | mosquitoes vector pathogens. one aspect that has been overlooked in mosquito-pathogen relationships is the effect of host age on immune competence. here, we show that there is age-associated mortality following immune challenge with escherichia coli. this mortality correlates with a decrease in haemocyte numbers (blood cells) and a decreased ability to kill e. coli. although the number of haemocytes decreases, the available haemocytes retain their phagocytic ability regardless of age, and we est ... | 2005 | 15617522 |
| targeted mutagenesis of loop residues in the receptor-binding domain of the bacillus thuringiensis cry4ba toxin affects larvicidal activity. | loop residues in domain ii of bacillus thuringiensis cry delta-endotoxins have been demonstrated to be involved in insecticidal specificity. in this study, selected residues in loops beta6-beta7 (s(387)sps(390)), beta8-beta9 (s(410), n(411), t(413), t(415), e(417) and g(418)) and beta10-beta11 (d(454)yns(457)) in domain ii of the cry4ba mosquito-larvicidal protein were changed individually to alanine by pcr-based directed mutagenesis. all mutant toxins were expressed in escherichia coli jm109 ce ... | 2005 | 15621455 |
| characterization of neuropeptide f and its receptor from the african malaria mosquito, anopheles gambiae. | the genome of anopheles gambiae contains sequences encoding a neuropeptide f (ang-npf) and npf receptor (ang-npfr) related to the neuropeptide y signaling family. cdnas for each were cloned and sequenced. ang-npfr was stably expressed for radioligand binding analysis. ang-npf exhibited high affinity (ic50 approximately 3 nm) membrane binding; npfs from aedes aegypti (aea-npf) and drosophila melanogaster (drm-npf) were less potent, with the rank order: ang-npf>aea-npf>drm-npf>drm-npf8-36. rt-pcr ... | 2005 | 15626509 |
| identification of mosquito sterol carrier protein-2 inhibitors. | a mosquito sterol carrier protein-2, aescp-2, has been shown to aid in the uptake of cholesterol in mosquito cells. the discovery of chemical inhibitors of aescp-2 is reported here. aescp-2 inhibitors (scpis) belong to several chemotypes of hydrophobic compounds. those inhibitors competed with cholesterol for aescp-2, binding with relatively high binding affinities. in cultured insect cells, scpis reduced cholesterol uptake by as much as 30% at 1-5 microm concentrations. scpis were potent larvic ... | 2005 | 15627652 |
| characterization of two novel pacifastin-like peptide precursor isoforms in the desert locust (schistocerca gregaria): cdna cloning, functional analysis and real-time rt-pcr gene expression studies. | in the last decade, a new serine protease inhibitor family has been described in arthropods. eight members of the family were purified from locusts and share a conserved cysteine array (cys-xaa(9-12)-cys-asn-xaa-cys-xaa-cys-xaa(2-3)-gly-xaa(3-6)-cys-thr-xaa3-cys) with nine inhibitory domains of the light chain of the crayfish protease inhibitor, pacifastin (plds; pacifastin light chain domains). using cdna cloning, several pacifastin-related precursors have been identified, encoding additional p ... | 2005 | 15631618 |
| detection of dengue viruses in field-caught aedes aegypti (diptera: culicidae) in maracay, aragua state, venezuela by type-specific polymerase chain reaction. | virological surveillance of dengue viruses in aedes aegypti populations constitutes a powerful tool for early prediction of dengue outbreaks. we have standardized a protocol for viral rna extraction from individual and pools of mosquitoes that permits a sensitive detection of dengue virus without rna degradation or pcr inhibition when we apply a semi-nested rt-pcr. the limit of detection for each dengue serotype was 0.1 pfu. in a prospective field study conducted from november 2000 to december 2 ... | 2005 | 15639750 |
| horizontal and vertical dispersal of dengue vector mosquitoes, aedes aegypti and aedes albopictus, in singapore. | to study the dispersal of dengue vector mosquitoes in singapore, females of aedes aegypti (l.) and aedes albopictus (skuse) (diptera: culicidae) were fed blood containing rubidium (rb), which was detectable in their eggs by means of graphite furnace atomic absorption spectrophotometry (gfaas). laboratory calibration of the rb reading, for a range of egg numbers from rb-fed females, indicated a reasonably linear relationship and an unequivocal distinction between results with zero and one marked ... | 2004 | 15642001 |
| microarray analysis for identification of plasmodium-refractoriness candidate genes in mosquitoes. | the identification and cloning of genes conferring mosquito refractoriness to the malaria parasite is critical for understanding malaria transmission mechanisms and holds great promise for developing novel approaches to malaria control. the mosquito midgut is the first major site of interaction between the parasite and the mosquito. failure of the parasite to negotiate this environment can be a barrier for development and is likely the main cause of mosquito refractoriness. this paper reports a ... | 2004 | 15644964 |
| gene expression patterns associated with blood-feeding in the malaria mosquito anopheles gambiae. | blood feeding, or hematophagy, is a behavior exhibited by female mosquitoes required both for reproduction and for transmission of pathogens. we determined the expression patterns of 3,068 ests, representing ~2,000 unique gene transcripts using cdna microarrays in adult female anopheles gambiae at selected times during the first two days following blood ingestion, at 5 and 30 min during a 40 minute blood meal and at 0, 1, 3, 5, 12, 16, 24 and 48 hours after completion of the blood meal and compa ... | 2005 | 15651988 |
| quantitative genetics of vector competence for la crosse virus and body size in ochlerotatus hendersoni and ochlerotatus triseriatus interspecific hybrids. | la crosse virus is a leading cause of pediatric encephalitis in the united states. the mosquito ochlerotatus triseriatus is an efficient vector for la crosse virus, whereas the closely related o. hendersoni transmits only at very low rates. quantitative trait loci (qtl) affecting the ability to orally transmit this virus and adult body size were identified in 164 f(2) female individuals from interspecific crosses of o. hendersoni females and o. triseriatus males using a combination of composite ... | 2005 | 15654112 |
| [aedes aegypti infestation and occurrence of dengue in the city of belo horizonte, brazil]. | to assess the association between the proportion of buildings positive for aedes aegypti larvae measured by means of building infestation rate and dengue incidence rate. | 2005 | 15654458 |
| intersectoral coordination in aedes aegypti control. a pilot project in havana city, cuba. | background the 55th world health assembly declared dengue prevention and control a priority and urged member states to develop sustainable intersectoral strategies to this end. to provide evidence for the reorientation of the dengue prevention policy in cuba, we launched an intervention study to document the effectiveness of a local-level intersectoral approach. | 2005 | 15655017 |
| the mosquito aedes aegypti (l.) leucokinin receptor is a multiligand receptor for the three aedes kinins. | a cdna cloned from aedes aegypti (l.) (aedae) female malpighian tubule (ay596453) encodes a 584 amino acid residue protein (65.2 kda) predicted as a g protein-coupled receptor and orthologue of the drosokinin receptor from drosophila melanogaster and highly similar to the tick boophilus microplus myokinin receptor (af228521). based on the similarity to this aedes sequence, we also propose a correction for the anopheles gambiae protein sequence eaa05450. when expressed in cho-k1 cells, the aedes ... | 2005 | 15663775 |
| pcr cloning of a histone h1 gene from anopheles stephensi mosquito cells: comparison of the protein sequence with histone h1-like, c-terminal extensions on mosquito ribosomal protein s6. | in aedes and anopheles mosquitoes, ribosomal protein rps6 has an unusual c-terminal extension that resembles histone h1 proteins. to explore homology between a mosquito h1 histone and the rps6 tail, we took advantage of the anopheles gambiae genome database to clone a histone h1 gene from an anopheles stephensi mosquito cell line. | 2005 | 15667661 |
| genetic structure of natural populations of aedes aegypti at the micro- and macrogeographic levels in brazil. | genetic variation in 13 populations of aedes aegypti from 3 regions of brazil was compared using variation at 10 isozyme loci. heterozygosities varied from 0.050 +/- 0.027 to 0.280 +/- 0.120, and a large genetic differentiation (f(st) = 0.144) was observed among all populations. the largest within-regions differences were found between populations from the urban areas of northeast brazil (f(st) = 0.152). ecological conditions are likely having an impact on the population structure of ae. aegypti ... | 2004 | 15669374 |
| surveillance and behavioral investigations of aedes aegypti and aedes polynesiensis in moorea, french polynesia, using a sticky ovitrap. | the effectiveness of the sticky ovitrap was assessed for the container-breeding aedes aegypti and aedes polynesiensis in moorea, french polynesia. these mosquitoes are the primary vectors of dengue viruses and bancroftian filariasis, respectively, in the area. both ae. aegypti and ae. polynesiensis were collected in greatest numbers in sticky ovitraps baited with water or grass infusions rather than leaf infusions. sticky ovitrap collections were significantly higher for both species in the 12 h ... | 2004 | 15669377 |
| the use of the copepod mesocyclops longisetus as a biological control agent for aedes aegypti in cali, colombia. | we present data on the efficacy of mesocyclops longisetus as a biocontrol agent in controlling aedes aegypti larvae in catch basins in cali, colombia. additionally, we determined some of the features that facilitated the establishment of the copepods in catch basins. between june 1999 and february 2000, 201 catch basins were treated with an average of 500 adult copepods. the copepods had established in 49.2% of all the basins and they maintained ae. aegypti larvae at low densities until the end ... | 2004 | 15669381 |
| effects of sublethal concentrations of vectobac on biological parameters of aedes aegypti. | the effect of sublethal concentrations (30% lethal concentration [lc30] = 0.41 ppm, lc50 = 1.04 ppm, and lc70 = 2.60 ppm) of vectobac 12 aqueous suspension (as, bacillus thuringiensis var. israelensis h-14, 600 itu/mg) on life parameters of aedes aegypti and its f1 progeny (not exposed) was assessed in laboratory tests. based on the data, it was clear that concentrations of 0.41 ppm of vectobac significantly shortened the duration of the developmental cycle of the exposed mosquitoes, but not tha ... | 2004 | 15669383 |
| production of polymorphic sperm by anopheline mosquitoes and their fate within the female genital tract. | the males of two mosquito species within the anopheles gambiae complex, an. gambiae s.s. and an. quadriannulatus, as well as males of an. darlingi, produced sperm of significantly varying lengths, while a sperm polymorphism was absent in aedes aegypti and other anophelines not suspected of belonging to species complexes. the polymorphic distribution of these sperm lengths was not significantly different in smaller adult males that were reared on a low larval diet. the reproductive tract of the f ... | 2004 | 15670863 |
| aedes aegypti salivary gland extracts modulate anti-viral and th1/th2 cytokine responses to sindbis virus infection. | vector-borne viruses are naturally transmitted when a vector salivates during feeding on a vertebrate host. most laboratory studies of infection disregard the role that the vector plays in the pathogenesis of the virus. in this study, intradermal inoculations of aedes aegypti salivary gland extract (sge) and sindbis virus (sinv) were used to investigate the effect of mosquito feeding on the vertebrate immune response to infection with an arthropod-borne virus. murine cytokine expression in the s ... | 2004 | 15671753 |
| maps of the sri lanka malaria situation preceding the tsunami and key aspects to be considered in the emergency phase and beyond. | following the tsunami, a detailed overview of the area specific transmission levels is essential in assessing the risk of malaria in sri lanka. recent information on vector insecticide resistance, parasite drug resistance, and insights into the national policy for malaria diagnosis and treatment are important in assisting national and international agencies in their control efforts. | 2005 | 15676073 |
| short communication: detection of dengue virus antigens in desiccated mosquitoes: an improved tool for surveillance. | we developed a surveillance tool to monitor dengue virus (denv) infection in vector mosquitoes using a dengue antigen-capture enzyme immunoassay (eia) on desiccated specimens stored at room temperature (rt). we tested the effect of storage on the stability of den1, den2, den3 and den4 antigens. although desiccated infected aedes aegypti mosquitoes stored between 31 and 34 degrees c (rt) showed greater reactivity in the eia than those stored at -80 degrees c, a significant difference between the ... | 2005 | 15679562 |
| laboratory and field trial of developing medicinal local thai plant products against four species of mosquito vectors. | oils of syzygium aromaticum (clove) and zanthoxylum limonella (makaen), widely used essential oils for dental caries or flavoring of food in thailand, were prepared as 10 experimental repellent products in gel or cream form against aedes aegypti, culex quinquefasciatus, and anopheles dirus under laboratory conditions, using the human-arm-in-cage method. two products that gave the longest-lasting complete protection were selected to examine their repellency against a variety of mosquito species u ... | 2004 | 15691131 |
| manduca sexta serpin-6 regulates immune serine proteinases pap-3 and hp8. cdna cloning, protein expression, inhibition kinetics, and function elucidation. | analogous to blood coagulation and complement activation in mammals, some insect defense responses (e.g. prophenoloxidase (propo) activation and toll pathway initiation) are mediated by serine proteinase cascades and regulated by serpins in hemolymph. we recently isolated manduca sexta serpin-6 from hemolymph of the bacteria-challenged larvae, which selectively inhibited propo-activating proteinase-3 (pap-3) (wang, y., and jiang, h. (2004) insect biochem. mol. biol. 34, 387-395). to further char ... | 2005 | 15691825 |
| tracking the re-emergence of epidemic chikungunya virus in indonesia. | twenty-four distinct outbreaks of probable chikungunya (chik) etiology were identified throughout indonesia from september 2001 to march 2003, after a near 20-year hiatus of epidemic chik activity in the country. thirteen outbreak reports were based on clinical observations alone, and 11 confirmed by serological/virological methods. detailed epidemiological profiles of two investigated outbreaks in bogor and bekasi are presented. human sera were screened using an elisa for igm and igg anti-chik ... | 2005 | 15693148 |
| host range and specificity of an argentinean isolate of the aquatic fungus leptolegnia chapmanii (oomycetes: saprolegniales), a pathogen of mosquito larvae (diptera: culicidae). | an isolate from argentina of the fungal mosquito pathogen leptolegnia chapmanii (arsef 5499), was tested against 12 species of mosquito larvae and on species of non-target aquatic invertebrates and vertebrates. the mosquito species tested were aedes aegypti, anopheles sp., culex apicinus, cx. castroi, cx. dolosus, cx. pipiens, cx. renatoi, isostomyia paranensis, ochlerotatus albifasciatus, oc. crinifer, psorophora cyanescens, and p. ferox. mosquito larvae of 10 species were susceptible, with mor ... | 2004 | 15702269 |
| synergism between ammonia, lactic acid and carboxylic acids as kairomones in the host-seeking behaviour of the malaria mosquito anopheles gambiae sensu stricto (diptera: culicidae). | host odours play a major role in the orientation and host location of blood-feeding mosquitoes. anopheles gambiae giles sensu stricto, which is the most important malaria vector in africa, is a highly anthropophilic mosquito species, and the host-seeking behaviour of the females of this mosquito is guided by volatiles of human origin. ammonia, lactic acid and several carboxylic acids are known to be present in the human odour blend. we investigated the effect of these compounds on naive female m ... | 2005 | 15703334 |
| dengue and dengue hemorrhagic fever, brazil, 1981-2002. | in the last 5 years, brazil has accounted for approximately 70% of reported dengue fever cases in the americas. we analyzed trends of dengue and dengue hemorrhagic fever (dhf) from the early 1980s to 2002 by using surveillance data from the brazilian ministry of health. two distinct epidemiologic patterns for dengue were observed: localized epidemics (1986-1993), and endemic and epidemic virus circulation countrywide (1994-2002). currently, serotypes 1, 2, and 3 cocirculate in 22 of 27 states. d ... | 2005 | 15705322 |
| exotic mosquitoes in new zealand: a review of species intercepted, their pathways and ports of entry. | a review was carried out to identify the exotic mosquito species intercepted in new zealand to 2004, together with their origins, pathways and ports of entry into the country. a total of 171 interceptions have been recorded since 1929. there was little or no taxonomic information available for many, but at least 27 exotic species not yet established in new zealand have been intercepted, including important disease vectors such as aedes albopictus, aedes aegypti and culex annulirostris. of 152 in ... | 2004 | 15707185 |
| combination of mesocyclops thermocyclopoides and bacillus thuringiensis var. israelensis: a better approach for the control of aedes aegypti larvae in water containers. | the efficacy of a local thai-strain of the copepod, mesocyclops thermocyclopoides and the larvicide, bacillus thuringiensis var. israelensis (bti), used jointly and singly, was studied against aedes aegypti in water containers. in a laboratory test, copepods alone produced mortality of 98-100% in 1st instar larvae of ae. aegypti at copepod:larvae ratios ranging from 1:1 to 1:4. in an outdoor field simulated experiment that ran for 16 wk, after a single inoculation, the treatment of copepods and ... | 2004 | 15707281 |
| the relative attractiveness of carbon dioxide and octenol in cdc- and evs-type light traps for sampling the mosquitoes aedes aegypti (l.), aedes polynesiensis marks, and culex quinquefasciatus say in moorea, french polynesia. | two dominant day-biting pests and vector species on the island of moorea in french polynesia are aedes (stegomyia) aegypti (l.) and aedes (stegomyia) polynesiensis marks, major vectors of dengue viruses and wuchereria bancrofti, respectively. their surveillance is hindered by a relative lack of attraction to light traps, necessitating the undesirable use of human bait collections with the inherent risks of pathogen transmission. the effectiveness of cdc- and evs-type light traps baited with olfa ... | 2004 | 15707289 |
| observations on the seasonal prevalence and vertical distribution patterns of oviposition by aedes aegypti (l.) (diptera: culicidae) in urban high-rise apartments in trinidad, west indies. | the seasonal prevalence and vertical distribution of oviposition of aedes aegypti were studied for 53 wk in 1999--2000 using modified ovitraps located at several elevations. the ovitraps were positioned both indoors and outdoors in high-rise apartments in the urban township of john john, port of spain, trinidad, west indies. of 988 ovitraps, 490 were collected during the months of the wet season, with 404 (84.4%) positive with 18,536 ae. aegypti eggs. of 498 ovitraps collected during the dry sea ... | 2004 | 15707291 |
| potential of crude seed extract of celery, apium graveolens l., against the mosquito aedes aegypti (l.) (diptera: culicidae). | crude seed extract of celery, apium graveolens, was investigated for anti-mosquito potential, including larvicidal, adulticidal, and repellent activities against aedes aegypti, the vector of dengue haemorrhagic fever. the ethanol-extracted a. graveolens possessed larvicidal activity against fourth instar larvae of ae. aegypti with ld50 and ld95 values of 81.0 and 176.8 mg/l, respectively. the abnormal movement observed in treated larvae indicated that the toxic effect of a. graveolens extract wa ... | 2004 | 15707293 |
| a study of the larvicidal and molluscicidal activities of some medicinal plants from northeast brazil. | in a search for natural products that could be used to control the vectors of tropical diseases, 23 extracts of medicinal plants from the northeast of brazil have been tested for molluscicidal activity against egg masses and adults of the snail biomphalaria glabrata, for larvicidal activity against the larvae of the mosquito aedes aegypti, and for general toxicity against the larvae of the brine shrimp artemia salina. of these extracts, two were active against the adult snail, one against snail ... | 2005 | 15707752 |
| new strategy against aedes aegypti in vietnam. | the container-breeding mosquito, aedes aegypti, is the major global vector of dengue viruses, causing around 50 million infections annually. we have developed a mosquito control strategy, incorporating four elements: (1) a combined vertical and horizontal approach that depends on community understanding; (2) prioritised control according to the larval productivity of major habitat types; (3) use of predacious copepods of the genus mesocyclops as a biological control agent; delivered by (4) commu ... | 2005 | 15708107 |
| larvicidal activity of lignans identified in phryma leptostachya var. asiatica roots against three mosquito species. | the insecticidal activity of phytochemicals isolated from the roots of phryma leptostachya var. asiatica against third instar larvae of culex pipiens pallens, aedes aegypti, and ocheratatos togoi was examined. the two constituents of p. leptostachya var. asiatica roots were identified as the leptostachyol acetate (i) and 8'-acetoxy-2,2',6-trimethoxy-3,4,4',5'-dimethylenedioxyphenyl-7,7'-dioxabicyclo[3.3.0]octane (ii) by spectroscopic analysis. compound i was lethal to c. pipiens pallens, a. aegy ... | 2005 | 15713007 |
| insecticidal amides from fruits of piper nigrum linn. | the petroleum ether and ethyl acetate fractions of dried ground seeds of piper nigrum linn. afforded sixteen compounds (1-16) including one new insecticidal amide, pipwaqarine (1) and six constituents (3,4,6,7,11,15) previously unreported from this plant. the structure of (1) has been elucidated through extensive 1d-, 2d-nmr spectral studies as, 1-[13-(3',4'-methylenedioxyphenyl)-2e,4e,12e-tridecatrienoyl]-n-isopentylamide, while those of known constituents through comparison of spectral data. 1 ... | 2005 | 15715258 |
| simultaneous infection with dengue 2 and 3 viruses in a chinese patient return from sri lanka. | dengue is an acute viral disease transmitted by the aedes aegypti and aedes albopictus mosquito, which are present in most tropical urban areas of the world. there are four antigenically distinct serotypes, designated dengue-1 (den-1), dengue-2 (den-2), dengue-3 (den-3) and dengue-4 (den-4). dengue outbreaks have occurred in several regions in asia, involving four serotypes of dengue 1, 2, 3 and 4. in review of the few cases of dual infection documented in the literature, we report here a case o ... | 2005 | 15722024 |
| rel1, a homologue of drosophila dorsal, regulates toll antifungal immune pathway in the female mosquito aedes aegypti. | signaling by drosophila toll pathway activates two rel/nf-kappab transcription factors, dorsal (dl) and dorsal-related immune factor (dif). dl plays a central role in the establishment of dorsoventral polarity during early embryogenesis, whereas dif mediates the toll receptor-dependent antifungal immune response in adult drosophila. the absence of a dif ortholog in mosquito genomes suggests that dl may play its functional role in the mosquito toll-mediated innate immune responses. we have cloned ... | 2005 | 15722339 |
| elimination of dengue by community programs using mesocyclops(copepoda) against aedes aegypti in central vietnam. | from september 2000 to june 2003, a community-based program for dengue control using local predacious copepods of the genus mesocyclops was conducted in three rural communes in the central vietnam provinces of quang nam, quang ngai, and khanh hoa. post-project, three subsequent entomologic surveys were conducted until march 2004. the number of households and residents in the communes were 5,913 and 27,167, respectively, and dengue notification rates for these communes from 1996 were as high as 2 ... | 2005 | 15728869 |
| persistence of vectobac wdg and metoprag s-2g against aedes aegypti larvae using a semi-field bioassay in rio de janeiro, brazil. | persistence of bacillus thuringiensis var. israelensis (vectobac wdg) and methoprene (metoprag s-2g) was evaluated against aedes aegypti late third instar larvae of the rockefeller strain in a semi-field bioassay. tests were performed in rio de janeiro, using containers made of plastic, iron, concrete and asbestos, placed in a shaded area. the formulations used were 0.2 g of vectobac-wdg and 1 g of metoprag s-2g per 100 liters of water in house storage containers. vectobac wdg was tested twice, ... | 2005 | 15729468 |
| size heterogeneity in the 3' noncoding region of south american isolates of yellow fever virus. | the 3' noncoding region (3' ncr) of flaviviruses contains secondary and tertiary structures essential for virus replication. previous studies of yellow fever virus (yfv) and dengue virus have found that modifications to the 3' ncr are sometimes associated with attenuation in vertebrate and/or mosquito hosts. the 3' ncrs of 117 isolates of south american yfv have been examined, and major deletions and/or duplications of conserved rna structures have been identified in several wild-type isolates. ... | 2005 | 15731274 |
| do malaria ookinete surface proteins p25 and p28 mediate parasite entry into mosquito midgut epithelial cells? | p25 and p28 are related ookinete surface proteins highly conserved throughout the plasmodium genus that are under consideration as candidates for inclusion in transmission-blocking vaccines. previous research using transgenic rodent malaria parasites lacking p25 and p28 has demonstrated that these proteins have multiple partially redundant functions during parasite infection of the mosquito vector, including an undefined role in ookinete traversal of the mosquito midgut epithelium, and it has be ... | 2005 | 15733320 |
| dispersal of the dengue vector aedes aegypti within and between rural communities. | knowledge of mosquito dispersal is critical for vector-borne disease control and prevention strategies and for understanding population structure and pathogen dissemination. we determined aedes aegypti flight range and dispersal patterns from 21 mark-release-recapture experiments conducted over 11 years (1991-2002) in puerto rico and thailand. dispersal was compared by release location, sex, age, season, and village. for all experiments, the majority of mosquitoes were collected from their relea ... | 2005 | 15741559 |
| midgut epithelial responses of different mosquito-plasmodium combinations: the actin cone zipper repair mechanism in aedes aegypti. | in vivo responses of midgut epithelial cells to ookinete invasion of three different vector-parasite combinations, aedes aegypti-plasmodium gallinaceum, anopheles stephensi-plasmodium berghei, and a. stephensi-p. gallinaceum, were directly compared by using enzymatic markers and immunofluorescence stainings. our studies indicate that, in a. aegypti and a. stephensi ookinetes traverse the midgut via an intracellular route and inflict irreversible damage to the invaded cells. these two mosquito sp ... | 2005 | 15753303 |
| the anopheles gambiae detoxification chip: a highly specific microarray to study metabolic-based insecticide resistance in malaria vectors. | metabolic pathways play an important role in insecticide resistance, but the full spectra of the genes involved in resistance has not been established. we constructed a microarray containing unique fragments from 230 anopheles gambiae genes putatively involved in insecticide metabolism [cytochrome p450s (p450s), gsts, and carboxylesterases and redox genes, partners of the p450 oxidative metabolic complex, and various controls]. we used this detox chip to monitor the expression of the detoxifying ... | 2005 | 15753317 |
| biochemical mode of action and differential activity of new ecdysone agonists against mosquitoes and moths. | thq (1-aroyl-4-(arylamino)-1,2,3,4-tetrahydroquinoline) compounds were identified by fmc corporation in cell-based assays that used ecdysone receptors from drosophila melanogaster, heliothis virescens, or plodia interpunctata. thq compounds showed weak insecticidal activity against h. virescens and, therefore, were not developed further. several ecdysone agonists based on thq chemotype have been synthesized and tested for their activity against a number of ecrs in transactivation assays. the thq ... | 2005 | 15756700 |
| a simplified high-throughput method for pyrethroid knock-down resistance (kdr) detection in anopheles gambiae. | a single base pair mutation in the sodium channel confers knock-down resistance to pyrethroids in many insect species. its occurrence in anopheles mosquitoes may have important implications for malaria vector control especially considering the current trend for large scale pyrethroid-treated bednet programmes. screening anopheles gambiae populations for the kdr mutation has become one of the mainstays of programmes that monitor the development of insecticide resistance. the screening is commonly ... | 2005 | 15766386 |
| phylogeography and population structure of aedes aegypti in arizona. | aedes aegypti, the mosquito responsible for transmitting dengue, has colonized many cities and towns throughout arizona. determining both the migration between, and the origin of, local ae. aegypti populations is important for vector control and disease prevention purposes. amplified fragment length polymorphism was used to infer geographic structure and local substructure, and effective migration rates (m, migrants per generation) between populations, and to determine genetic differentiation be ... | 2005 | 15772327 |
| quantitative trait loci that control dengue-2 virus dissemination in the mosquito aedes aegypti. | the mosquito aedes aegypti is the most important vector of yellow fever and dengue fever flaviviruses. ae. aegypti eradication campaigns have not been sustainable and there are no effective vaccines for dengue viruses. alternative control strategies may depend upon identification of mosquito genes that condition flavivirus susceptibility and may ultimately provide clues for interrupting transmission. quantitative trait loci affecting the ability of ae. aegypti to develop a dengue-2 infection in ... | 2005 | 15781707 |
| heterologous expression of the filarial nematode alt gene products reveals their potential to inhibit immune function. | parasites exploit sophisticated strategies to evade host immunity that require both adaptation of existing genes and evolution of new gene families. we have addressed this question by testing the immunological function of novel genes from helminth parasites, in which conventional transgenesis is not yet possible. we investigated two such novel genes from brugia malayi termed abundant larval transcript (alt), expression of which reaches ~5% of total transcript at the time parasites enter the huma ... | 2005 | 15788098 |
| target of rapamycin-dependent activation of s6 kinase is a central step in the transduction of nutritional signals during egg development in a mosquito. | female mosquitoes are effective disease vectors, because they take blood from vertebrate hosts to obtain nutrients for egg development. amino acid signaling via the target of rapamycin (tor) pathway has been identified as a key requirement for the activation of egg development after a blood meal. we report the characterization of the tor kinase and one of its major downstream targets, s6 kinase, of the yellow fever mosquito aedes aegypti during egg development in adult females. both tor and s6k ... | 2005 | 15788394 |
| heat shock protein 90 and heat shock protein 70 are components of dengue virus receptor complex in human cells. | dengue virus requires the presence of an unidentified cellular receptor on the surface of the host cell. by using a recently published affinity chromatography approach, an 84-kda molecule, identified as heat shock protein 90 (hsp90) by matrix-assisted laser desorption ionization-time of flight mass spectrometry, was isolated from neuroblastoma and u937 cells. based on the ability of hsp90 (84 kda) to interact with hsp70 (74 kda) on the surface of monocytes during lipopolysaccharide (lps) signali ... | 2005 | 15795242 |
| inhibition of dengue virus serotypes 1 to 4 in vero cell cultures with morpholino oligomers. | five dengue (den) virus-specific r5f2r4 peptide-conjugated phosphorodiamidate morpholino oligomers (p4-pmos) were evaluated for their ability to inhibit replication of den virus serotype 2 (den-2 virus) in mammalian cell culture. initial growth curves of den-2 virus 16681 were obtained in vero cells incubated with 20 microm p4-pmo compounds. at 6 days after infection, a p4-pmo targeting the 3'-terminal nucleotides of the den-2 virus genome and a random-sequence p4-pmo showed relatively little su ... | 2005 | 15795296 |
| structural requirements of the unique disulphide bond and the proline-rich motif within the alpha4-alpha5 loop for larvicidal activity of the bacillus thuringiensis cry4aa delta-endotoxin. | both the disulphide bond (cys192-cys199) and the proline-rich motif (pro193proasnpro196) in the long loop connecting the alpha4-alpha5 transmembrane hairpin of the cry4aa mosquito-larvicidal protein have been found to be unique among the bacillus thuringiensis cry delta-endotoxins. in this study, their structural requirements for larvicidal activity of the cry4aa toxin were investigated. c192a and c199a mutant toxins were initially generated and over-expressed in escherichia coli cells as 130-kd ... | 2005 | 15796913 |
| selection of d2s3, an aedes aegypti (diptera: culicidae) strain with high oral susceptibility to dengue 2 virus and d2meb, a strain with a midgut barrier to dengue 2 escape. | family-based phenotypic selection was used to breed two genetic strains of aedes aegypti l. that differ in susceptibility to infection with dengue serotype 2 virus (den-2) strain jam1409. a dengue 2 susceptible on 3 chromosomes (d2s3) strain was bred from ae. aegypti aegypti and ae. aegyptiformosus p1 parents to have a high midgut infection rate (mir) and a high disseminated infection rate (dir). a dengue 2 midgut escape barrier (d2meb) strain was bred from d2s3 and houston p1 parents to have a ... | 2005 | 15799518 |
| investigation of relationships between aedes aegypti egg, larvae, pupae, and adult density indices where their main breeding sites were located indoors. | aedes aegypti (l.) density indices obtained in a dengue fever (df) endemic area were compared. one hundred and twenty premises, in an urban area of colombia where dengue type-1 and type-2 virus cocirculated, were randomly selected and sampled for 7 months. the geometric mean monthly numbers (density index, di) of ae. aegypti eggs (odi), 4th instar larvae (ldi), pupae (pdi), and adults (adi) were calculated based on the use of ovitraps, nets, and manual aspirators, respectively. a negative tempor ... | 2005 | 15825756 |
| a new in vitro bioassay system for discovery of novel human-use mosquito repellents. | a klun & debboun (k&d) test module, previously developed and used for quantitative measurement of the efficacy of mosquito repellents on human volunteers, was adapted for in vitro evaluation of repellents by coupling the module with a membrane-blood reservoir. performance of deet, bayrepel, and ss-220 insect repellents in the new in vitro system was compared with their performance on humans against mosquitoes using our standard in vivo system. for each compound, in vitro dose-response assays wer ... | 2005 | 15825764 |
| integration of bacillus thuringiensis h-14 formulations and pyriproxyfen for the control of larvae of aedes aegypti and aedes albopictus. | studies were carried out on the bioefficacy and residual activity of bacillus thuringiensis israelensis h-14 (bti) (water-dispersible granules of vectobac abg 6511 and liquid formulations of vectobac 12as) and pyriproxyfen (insect growth regulator, sumilarv 0.5%) as direct applications for control of larvae of aedes aegypti and aedes albopictus. two dosages of each bti formulation (285 and 570 international toxic units [itu]/liter) and the integration of both bti formulations and pyriproxyfen we ... | 2005 | 15825767 |
| genetic structure of aedes aegypti populations in thailand using mitochondrial dna. | a hierarchical population genetic study was conducted among 19 aedes aegypti populations in thailand from chiang mai in the north to songkhla province in the south. single-strand conformation polymorphism analysis was used to examine variation in a 359-basepair region of the nadh dehydrogenase subunit 4 mitochondrial dna gene (nd4). seven haplotypes were detected in two lineages previously identified in nd4 haplotypes from north america. gene flow estimates and highly significant variation among ... | 2005 | 15827282 |
| reconsideration of histopathology and ultrastructural aspects of the human liver in yellow fever. | yellow fever is a re-emerging infectious disease that currently is at risk of urbanization due to the advance of the aedes aegypti vector. the disease affects about 200,000 individuals annually, mainly in tropical africa and south america. it causes severe disease involving especially the liver, with lesions characterized by midzonal steatosis, apoptosis and lytic necrosis of the hepatocytes. quantitative histological and immunohistochemical analysis of 53 human hepatic samples demonstrated apop ... | 2005 | 15829426 |
| pilot anopheles gambiae full-length cdna study: sequencing and initial characterization of 35,575 clones. | we describe the preliminary analysis of over 35,000 clones from a full-length enriched cdna library from the malaria mosquito vector anopheles gambiae. the clones define nearly 3,700 genes, of which around 2,600 significantly improve current gene definitions. an additional 17% of the genes were not previously annotated, suggesting that an equal percentage may be missing from the current anopheles genome annotation. | 2005 | 15833126 |
| 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 |
| induction of nitric oxide synthase in anopheles stephensi by plasmodium falciparum: mechanism of signaling and the role of parasite glycosylphosphatidylinositols. | malaria parasite (plasmodium spp.) infection in the mosquito anopheles stephensi induces significant expression of a. stephensi nitric oxide synthase (asnos) in the midgut epithelium as early as 6 h postinfection and intermittently thereafter. this induction results in the synthesis of inflammatory levels of nitric oxide (no) in the blood-filled midgut that adversely impact parasite development. in mammals, p. falciparum glycosylphosphatidylinositols (pfgpis) can induce nos expression in immune ... | 2005 | 15845481 |
| [resistance to insecticides in larvae and adults of aedes aegypti, havana city: prevalence of a4 esterasa associated with resistance to temephos]. | 2 strains of aedes aegypti from 2 people's councils with high indexes of infestation of this vector were studied due to the need of carrying out an effective control of larvae and adults in the municipality of guanabacoa. the levels of susceptibility and/or resistance to organophosphate insecticides, pyrethroids and a carbamate were determined. the results of the bioassays in larvae showed a complete susceptibility to organophosphate insecticides, malathion, clorpirifos, methyl-pyrimifos and pro ... | 2004 | 15849910 |
| [status of resistance to insecticides and resistance mechanisms in larvae from playa municipality collected during the intensive campaign against aedes aegypti in havana city, 2001-2002]. | the levels of susceptibility and/or resistance to inseciticides in aedes aegypti larvae collected at the municipality of playa during the intensive campaign against the mosquito aedes aegypti, in havana city, in the present year, were determined. in larvae, it was found a high resistance to the organophosphate insecticides phention and temephos and moderate to fenitrothion. a high resistance to propoxur carbamate was also detected. the larvae proved to be susceptible to clorpirifos, malathion an ... | 2004 | 15849911 |
| [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 |
| primary characterization and basal promoter activity of two hexamerin genes of musca domestica. | hexamerins are high molecular-weight proteins found in the hemolymph of insects and have been proposed to function as storage proteins. in previous studies, two musca domestica hexamerins, designated hex-l and hex-f were characterized. hex-l is synthesized exclusively by the larval fat bodies, is secreted into the hemolymph and likely provides a source of amino acids and energy during metamorphosis. hex-f synthesis is induced by a proteinaceous meal and occurs only in the adult insect fat bodies ... | 2004 | 15861218 |
| entomopathogenic fungi for mosquito control: a review. | fungal diseases in insects are common and widespread and can decimate their populations in spectacular epizootics. virtually all insect orders are susceptible to fungal diseases, including dipterans. fungal pathogens such as lagenidium, coelomomyces and culicinomyces are known to affect mosquito populations, and have been studied extensively. there are, however, many other fungi that infect and kill mosquitoes at the larval and/or adult stage. the discovery, in 1977, of the selective mosquito-pa ... | 2004 | 15861235 |
| culex quinquefasciatus (diptera: culicidae) as a potential west nile virus vector in tucson, arizona: blood meal analysis indicates feeding on both humans and birds. | most reports from the united states suggest culex quinquefasciatus mosquitoes feed minimally on humans. given the abundance of c. quinquefasciatus in residential tucson and parts of metropolitan phoenix, and the arrival of west nile virus to this area, discovering the blood meal hosts of the local population is important. using a sandwich elisa technique, the local c. quinquefasciatus were found to feed on both humans and birds. this suggests they should be considered potential west nile virus v ... | 2004 | 15861236 |
| influence of age and previous diet of anopheles gambiae on the infectivity of natural plasmodium falciparum gametocytes from human volunteers. | the effect of age and dietary factors of anopheles gambiae (diptera: culicidae) on the infectivity of natural plasmodium falciparum parasites was studied. mosquitoes of various ages (1-3, 4-7 and 8-11 day old) and those fed blood (either single or double meals) and sugar meals were experimentally co-infected with p. falciparum gametocytes obtained from different naturally infected human volunteers. on day 7, midguts were examined for oocyst infection to determine whether mosquito age or diets ha ... | 2004 | 15861248 |
| serine proteinase over-expression in relation to deltamethrin resistance in culex pipiens pallens. | two serine proteinase genes were isolated from culex pipiens pallens as significantly up-regulated genes in a deltamethrin-resistant strain through a combination of suppression substractive hybridization and gene expression profiling by macroarrays. these two genes were found to be expressed at least threefold higher in the resistant strain than in the susceptible one. by using rapid amplification of cdna ends to screen the constructed cdna library, we cloned these two sequences. there were 909 ... | 2005 | 15876421 |
| dengue: a review of the laboratory tests a clinician must know to achieve a correct diagnosis. | dengue is the most important disease caused by an arbovirus (1, 2, 3 and 4 serotypes) worldwide, especially in the tropical and sub-tropical regions. its clinical manifestations range from asymptomatic infections to a severe disease characterized by hemorrhage and shock. the incidence of dengue virus activity in the americas has substantially increased from 1980 to 1994. in brazil, the increase in the incidence of dengue is especially linked to the dissemination of aedes aegypti. thus, a rapid a ... | 2004 | 15880229 |
| dengue fever, hawaii, 2001-2002. | autochthonous dengue infections were last reported in hawaii in 1944. in september 2001, the hawaii department of health was notified of an unusual febrile illness in a resident with no travel history; dengue fever was confirmed. during the investigation, 1,644 persons with locally acquired denguelike illness were evaluated, and 122 (7%) laboratory-positive dengue infections were identified; dengue virus serotype 1 was isolated from 15 patients. no cases of dengue hemorrhagic fever or shock synd ... | 2005 | 15890132 |
| retinal hemorrhages in 4 patients with dengue fever. | we report 4 patients with retinal hemorrhages that developed during hospitalization for dengue fever. onset of symptoms coincided with resolution of fever and the nadir of thrombocytopenia. retinal hemorrhages may reflect the rising incidence of dengue in singapore or may be caused by changes in the predominant serotype of the dengue virus. | 2005 | 15890137 |
| differential infectivities of o'nyong-nyong and chikungunya virus isolates in anopheles gambiae and aedes aegypti mosquitoes. | o'nyong-nyong virus (onnv) and chikungunya virus (chikv) are closely related alphaviruses that cause human disease in africa and asia. like most alphaviruses, chikv is vectored by culicine mosquitoes. onnv is considered unusual as it primarily infects anopheline mosquitoes; however, there are relatively few experimental data to support this. in this study, three strains of onnv and one strain of chikv were evaluated in anopheles gambiae and aedes aegypti mosquitoes and in four cell lines. as pre ... | 2005 | 15891138 |
| effect of mosquito midgut trypsin activity on dengue-2 virus infection and dissemination in aedes aegypti. | the effect of mosquito midgut trypsins in dengue serotype 2 flavivirus (denv-2) infectivity to aedes aegypti was studied. addition of soybean trypsin inhibitor (sti) in a denv-2 infectious blood meal resulted in a 91-97% decrease in midgut denv-2 rna copies (qrt-pcr analysis). sti treatment also resulted in slower denv-2 replication in the midgut, less denv-2 e protein expression, and decreased dissemination to the thorax and the head. a second uninfected blood meal, 7 days after the sti-treated ... | 2005 | 15891140 |
| the unexpected importance of mosquito oviposition behaviour for malaria: non-productive larval habitats can be sources for malaria transmission. | mosquitoes commute between blood-meal hosts and water. thus, heterogeneity in human biting reflects underlying spatial heterogeneity in the distribution and suitability of larval habitat as well as inherent differences in the attractiveness, suitability and distribution of blood-meal hosts. one of the possible strategies of malaria control is to identify local vector species and then attack water bodies that contain their larvae. | 2005 | 15892886 |
| association mapping of segregating sites in the early trypsin gene and susceptibility to dengue-2 virus in the mosquito aedes aegypti. | evidence suggests that midgut trypsins in aedes aegypti condition the mosquito's ability to become infected with the dengue-2 flavivirus (den2). the activity of early trypsin protein peaks approximately 3 h after blood feeding and then drops within a few hours. we use association mapping to test the hypothesis that segregating sites in early trypsin condition midgut susceptibility to den2 virus. a total of 1642 females from throughout mexico and the southern us were fed an artificial blood meal ... | 2005 | 15894193 |
| nanos (nos) genes of the vector mosquitoes, anopheles gambiae, anopheles stephensi and aedes aegypti. | a number of genetics-based strategies for the control of vector-borne diseases require the development of genetic drive systems for introgressing antipathogen effector genes into wild populations of insects. modified transposons whose mobilization is controlled by the dna elements of developmentally regulated genes offer a potential solution for introducing effector genes into mosquitoes. such elements could exhibit sex-, stage- and species-specific transposition, thus mitigating some of the con ... | 2005 | 15894194 |
| [anthropophilic activity of aedes aegypti and of aedes albopictus in area under control and surveillance]. | to describe the hematophagous activity of ae. aegypti and ae. albopictus in an area under control and surveillance. | 2005 | 15895139 |
| [aedes (stegomyia) aegypti (linnaeus, 1762) breeding sites in native bromeliads in vitória city, es]. | some insects that are vectors of human diseases have accompanied man in his migrations throughout the world and breed exclusively in the proximity of human dwellings. the mosquito aedes aegypti has been responsible for epidemics of dengue in brazil and its presence also constitutes a serious risk for future outbreaks of urban yellow fever. the failure of campaigns to eradicate this species justifies the search for alternative breeding sites, which may be beyond the reach of present control measu ... | 2005 | 15895175 |
| [identification of places with potential transmission of dengue fever in porto alegre using geographical information systems]. | the social-environmental conditions that promote the continuity of aedes aegypti in urban areas and its capacity for dengue transmission have yet to be determined. the aim of this work was to locate dengue cases and vector presence, then to identify social-environmental factors that characterize these sites, through geographical information systems (gis), with a view to developing a dengue fever prevention model. the vector was mainly located in south and east areas of the city, with a broad dis ... | 2005 | 15895177 |
| more dengue, more questions. | | 2005 | 15898172 |
| rag1 core and v(d)j recombination signal sequences were derived from transib transposons. | the v(d)j recombination reaction in jawed vertebrates is catalyzed by the rag1 and rag2 proteins, which are believed to have emerged approximately 500 million years ago from transposon-encoded proteins. yet no transposase sequence similar to rag1 or rag2 has been found. here we show that the approximately 600-amino acid "core" region of rag1 required for its catalytic activity is significantly similar to the transposase encoded by dna transposons that belong to the transib superfamily. this supe ... | 2005 | 15898832 |
| intravital observation of plasmodium berghei sporozoite infection of the liver. | plasmodium sporozoite invasion of liver cells has been an extremely elusive event to study. in the prevailing model, sporozoites enter the liver by passing through kupffer cells, but this model was based solely on incidental observations in fixed specimens and on biochemical and physiological data. to obtain direct information on the dynamics of sporozoite infection of the liver, we infected live mice with red or green fluorescent plasmodium berghei sporozoites and monitored their behavior using ... | 2005 | 15901208 |
| seasonal fluctuations of dengue fever vector, aedes aegypti (diptera: culicidae) in delhi, india. | studies on the seasonal fluctuation of aedes aegypti were undertaken in different localities of delhi, during 2000. the aedes aegypti population was found to be prevalent in all the localities in delhi. water coolers and tires were found to be the preferred breeding habitats of aedes mosquitos in the city. aedes aegypti, being hygroscopic, showed a phenomenon of annual pulsation. it tends to move to mother foci in the central areas of the city, which are humid in the dry season, and spread out d ... | 2005 | 15906665 |
| 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 |
| characterization of an infectious clone of the wild-type yellow fever virus asibi strain that is able to infect and disseminate in mosquitoes. | infectious clone technology provides an opportunity to study the molecular basis of arthropod-virus interactions in detail. this study describes the development of an infectious clone of the prototype yellow fever virus asibi strain (yfv-as) with the purpose of identifying sequences or domains that influence infection dynamics in the mosquito vector. the full-length cdna of yfv-as virus was produced from rt-pcr products of parental viral rna. these were cloned into a low-copy-number plasmid prev ... | 2005 | 15914853 |
| bottle and biochemical assays on temephos resistance in aedes aegypti in thailand. | the bottle bioassay measuring the time-mortality rate is a simplified procedure for detecting insecticide resistance. it can be used with a biochemical microplate assay to identify the mechanism involved. this integrated approach was used to detect temephos resistance in aedes aegypti from nonthaburi (lowest use) and roi et (highest use). ae. aegypti bkk1 laboratory strain was used as the susceptible reference strain. the appropriate concentration of insecticide for bottle bioassay was determine ... | 2005 | 15916049 |
| the geographic information system as an epidemiological tool in the surveillance of dengue virus-infected aedes mosquitos. | a geographic information system (gis) was used as analysis tool to study the spatial distribution of dengue virus-infected aedes mosquitos in thailand. global positioning system (gps) instruments were used to map villages involved in dengue epidemiological studies in ratchaburi province, thailand. differentially processed gps data, with a spatial resolution of approximately 1 meter, were incorporated into a gis for analysis and mapping. databases associated with a village gis included village nu ... | 2004 | 15916091 |
| chimeric dengue 2 pdk-53/west nile ny99 viruses retain the phenotypic attenuation markers of the candidate pdk-53 vaccine virus and protect mice against lethal challenge with west nile virus. | chimeric dengue serotype 2/west nile (d2/wn) viruses expressing prm-e of wn ny99 virus in the genetic background of wild-type d2 16681 virus and two candidate d2 pdk-53 vaccine variants (pdk53-e and pdk53-v) were engineered. the viability of the d2/wn viruses required incorporation of the wn virus-specific signal sequence for prm. introduction of two mutations at m-58 and e-191 in the chimeric cdna clones further improved the viability of the chimeras constructed in all three d2 carriers. two d2 ... | 2005 | 15919884 |
| [impact on the potential epidemic of dengue fever under warming winter in hainan province]. | impact of climate warming in winter on the potential epidemics of dengue fever in hainan was assessed. | 2005 | 15921588 |
| mosquito phenoloxidase and defensin colocalize in melanization innate immune responses. | mosquitoes mount strong humoral and cellular immune responses against foreign organisms. two components of the mosquito immune response that have received much attention are the phenoloxidase cascade that leads to melanization and antimicrobial peptides. the purpose of the current study was to use immunocytochemistry and transmission electron microscopy to identify the location of the melanization rate-limiting enzyme phenoloxidase and the antimicrobial peptide defensin in innate immune reaction ... | 2005 | 15928318 |