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mosquito transposable elements.the completion of the genome assembly for the african malaria mosquito, anopheles gambiae, and continuing genomic efforts for the yellow fever mosquito, aedes aegypti, have allowed the use of bioinformatics tools to identify and characterize a diverse array of transposable elements (tes) in these and other mosquito genomes. an overview of the types and number of both rna-mediated and dna-mediated tes that are found in mosquito genomes is presented. a number of novel and interesting tes from thes ...200415242704
olfactory regulation of mosquito-host interactions.mosquitoes that act as disease vectors rely upon olfactory cues to direct several important behaviors that are fundamentally involved in establishing their overall vectorial capacity. of these, the propensity to select humans for blood feeding is arguably the most important of these olfactory driven behaviors in so far as it significantly contributes to the ability of these mosquitoes to transmit pathogens that cause diseases such as dengue, yellow fever and most significantly human malaria. her ...200415242705
nutritional regulation of jh synthesis: a mechanism to control reproductive maturation in mosquitoes?juvenile hormone (jh) titers must be modulated to permit the normal progress of development and reproduction in mosquitoes. in adult female aedes aegypti, jh levels are low at adult eclosion, elevated in sugar-fed females and low again after a blood meal. although degradation plays a role, jh titer is fundamentally determined by the rate of biosynthesis in the corpora allata gland (ca). ca from newly eclosed females (0-1 h after emergence) exhibit a very low basal jh biosynthetic activity, aedes ...200415242710
impact of population age structure on wolbachia transgene driver efficacy: ecologically complex factors and release of genetically modified mosquitoes.wolbachia symbionts hold theoretical promise as a way to drive transgenes into insect vector populations for disease prevention. for simplicity, current models of wolbachia dynamics and spread ignore ecologically complex factors such as the age structure of vector populations and overlapping vector generations. we developed a model including these factors to assess their impact on the process of wolbachia spread into populations of three mosquito species (anopheles gambiae, aedes aegypti and cul ...200415242712
current advances in dengue diagnosis. 200415242935
piptigrine, a new insecticidal amide from piper nigrum linn.a new insecticidal amide piptigrine (1) possessing highly extended conjugation was isolated from the dried ground seeds of piper nigrum linn. along with the known amides piperine and wisanine (hitherto unreported from this plant). the structure of 1 has been elucidated as 1-[9-(3',4'-methylenedioxyphenyl)-4e,6e,8e-nonatrienoyl]piperidine through extensive 1d- and 2d-nmr (cosy-45, noesy, j-resolved, hmqc, hmbc and noesy studies. the known compounds have been identified through comparison of their ...200415248617
aedes aegypti resistance to temephos during 2001 in several municipalities in the states of rio de janeiro, sergipe, and alagoas, brazil.for more than 30 years temephos, an organophosphate insecticide, has been the sole larvicide used in brazil in the control of aedes aegypti. organophosphates were also used for adult control, being replaced by pyrethroids since 1999. in this same year the brazilian health foundation started the coordination of the ae. aegypti insecticide resistance monitoring program. in the context of this program, our group was responsible for the detection of temephos resistance in a total of 12 municipalitie ...200415250476
tents pre-treated with insecticide for malaria control in refugee camps: an entomological evaluation.a refugee shelter that is treated with insecticide during manufacture would be useful for malaria control at the acute stage of an emergency, when logistic problems, poor co-ordination and insecurity limit the options for malaria control.200415253773
evaluation of an in vitro bloodfeeding system for testing mosquito repellents.median effective doses and 95% effective doses of 9 commercial mosquito repellents were determined for the yellow fever mosquito, aedes aegypti, in an in vitro bloodfeeding test system and on the human forearm. results obtained in the 2 test systems did not differ significantly but, because of the inherent variability of repellent test data, did not always agree closely. potential modifications of in vitro bloodfeeding test systems for increased accuracy, precision, and reliability are discussed ...200415264624
efficacy and longevity of a new formulation of temephos larvicide tested in village-scale trials against larval aedes aegypti in water-storage containers.field trials on the initial and long-term efficacy of a new formulation of temephos granules (1% on zeolite) applied at 1 ppm active ingredient (ai) were conducted in water-storage containers against aedes aegypti in 3 villages in the kanchanaburi province in thailand. a total of 316 water-storage containers of various types and sizes were included in the study. in the initial survey, we found that some containers were positive for larval ae. aegypti, whereas others were devoid of larvae before ...200415264628
antagonistic effects of energy status on meal size and egg-batch size of aedes aegypti (diptera: culicidae).the effect of sugar feeding on egg-batch size in aedes aegypti was examined in a way that would distinguish between the roles of a recent sugar meal (full vs. empty crop) and of repeated sugar feeding and digestion (high vs. low energy reserves). egg numbers of females representing the four combinations of these characteristics (full crop/high reserves, full crop/low reserves, empty crop/high reserves, empty crop/low reserves) were counted during their first gonotrophic cycle. in addition, the s ...200415266745
the invasion of urban forest by dengue vectors in rio de janeiro.the invasion of a secondary forest within the city of rio de janeiro by aedes aegypti and ae. albopictus was evaluated from july 1997 to june 1998 through collections of immature stages in ovitraps set at 1 m, 10 m, 100 m, 500 m, and 1,000 m into the forest from houses on the periphery. both mosquito species were much more abundant close to houses (1-10 m). aedes aegypti was not collected beyond 100 m, while ae. albopictus was the most abundant species overall and in ovitraps at all distances fr ...200415266746
oviposition by aedes aegypti (diptera: culicidae) in relation to conspecific larvae infected with internal symbiotes.female mosquitoes use abiotic and biotic factors, such as the presence of heavy metals or parasites, to determine the acceptability of oviposition sites. some biotic factors can originate from mosquito larvae. when mosquito larvae are starved or infected with trematode metacercaria, they render associated water unacceptable to ovipositioning females. internal symbiotes are common in wild mosquito populations, and i tested whether or not larvae of aedes aegypti infected with a gregarine (ascogreg ...200415266753
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.200315267144
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 ...200315270540
the cost of immunity in the yellow fever mosquito, aedes aegypti depends on immune activation.although host immunity offers the obvious benefit of reducing parasite infection, it is often traded-off with other fitness components. we investigated whether the cost of an immune response in the yellow fever mosquito, aedes aegypti, is modulated by the antigen that activates the melanization immune response. thus, one of three different novel antigens were injected into the mosquito's thorax--either a glass bead, a negatively charged (c-25) sephadex bead, or a neutral (g-25) sephadex bead--an ...200415271083
effect of ten chlorophytes on larval survival, development and adult body size of the mosquito aedes aegypti.the effect of ten microalgal chlorophytes isolated from mosquito breeding containers on the survival, larval development and adult body size of the mosquito aedes aegypti was investigated. all larvae fed with six of the microalgal isolates died after 7 days. these isolates were found to be resistant to digestion by mosquito larvae. delayed pupation and body size reduction of the mosquitos fed with chlorococcum umacc 218 and scenedesmus umacc 220 were observed. in contrast, larvae fed with ankist ...200415272748
venezuelan equine encephalitis emergence: enhanced vector infection from a single amino acid substitution in the envelope glycoprotein.in 1993 and 1996, subtype ie venezuelan equine encephalitis (vee) virus caused epizootics in the mexican states of chiapas and oaxaca. previously, only subtype iab and ic vee virus strains had been associated with major outbreaks of equine and human disease. the iab and ic epizootics are believed to emerge via adaptation of enzootic (sylvatic, equine-avirulent) strains for high titer equine viremia that results in efficient infection of mosquito vectors. however, experimental equine infections w ...200415277679
modulation of dengue virus infection of dendritic cells by aedes aegypti saliva.dengue virus (dv) is a flavivirus carried by the aedes aegypti mosquito that causes a spectrum of illnesses in the tropics, including dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. dendritic cells (dcs) are professional antigen presenting cells recently shown to be permissive for dv, and implicated as the primary targets of initial dv infection. dv is transmitted to human host by infected mosquitoes during a blood meal, but it is currently unknown whether transmission is modi ...200415279703
cloning and characterization of a mosquito larvicidal toxin produced during vegetative stage of bacillus sphaericus 2297.the mosquitocidal toxin 1 (mtx1) gene from genomic dna of b. sphaericus strain 2297 was cloned and expressed in e. coli. dna sequencing analysis of the cloned gene revealed a single open reading frame encoding an 870-amino acid polypeptide. expression level of the full-length gene in e. coli was very low even though strong promoter was used or the gene was expressed as a fusion protein. expression level was highly improved after the putative leader sequence was deleted, and the truncated gene wa ...200415297911
attenuation of dengue virus infection by adeno-associated virus-mediated sirna delivery.background: the need for safe and effective treatment of dengue virus (den), a class a agent that causes dengue hemorrhagic fever/dengue shock syndrome, has been a critical global priority. an effective vaccine for den is not yet available. in this study the possibility of attenuating den infection using adeno-associated virus (aav)-encoded short interfering rnas (sirna) was examined in vero cells and human dendritic cells (dcs). methods: a cassette encoding sirna targeted to a 3' untranslated s ...200415301687
direct and indirect immunosuppression by a malaria parasite in its mosquito vector.malaria parasites develop as oocysts within the haemocoel of their mosquito vector during a period that is longer than the average lifespan of many of their vectors. how can they escape from the mosquito's immune responses during their long development? whereas older oocysts might camouflage themselves by incorporating mosquito-derived proteins into their surface capsule, younger stages are susceptible to the mosquito's immune response and must rely on other methods of immune evasion. we show th ...200415306308
adult size and distribution of aedes aegypti (diptera: culicidae) associated with larval habitats in iquitos, peru.adult mosquito size may be related to longevity, feeding frequency, and other factors that impact vectorial capacity. various investigations have shown that characteristics of larval mosquito habitats influence adult size. we studied breeding container characteristics in relation to size and abundance of aedes aegypti larvae and pupae in iquitos, peru, and compared these with the size of resulting adult females. during 22 may to 20 july 2000, immature mosquitoes were collected from 12,722 contai ...200415311454
comparisons of amplified fragment length polymorphism (aflp), microsatellite, and isoenzyme markers: population genetics of aedes aegypti (diptera: culicidae) from phnom penh (cambodia).aedes aegypti is the main vector of dengue viruses responsible for dengue hemorrhagic fever, which has become a major public health concern in tropical countries. because vaccines are still under development, dengue prevention depends entirely on vector control. knowledge of gene dispersal patterns is required to develop efficient vector control strategies. here we report the use of amplified fragment length polymorphism (aflp) to infer the genetic structure of ae. aegypti populations at a local ...200415311458
dinotefuran: a potential neonicotinoid insecticide against resistant mosquitoes.because pyrethroid, organophosphate, and carbamate resistance is more and more developed in mosquitoes of medical importance, there is an urgent need for alternative insecticides for vector control. dinotefuran, a new neonicotinoid insecticide commercialized by mitsui chemicals (tokyo, japan), could be a useful candidate in public health because it shows low mammalian toxicity and great insecticidal activity against a broad range of pests. in this study, the intrinsic toxicity of dinotefuran was ...200415311465
mutations in the bacillus thuringiensis cry1ca toxin demonstrate the role of domains ii and iii in specificity towards spodoptera exigua larvae.several mutants of the bacillus thuringiensis cry1ca toxin affected with regard to specific activity towards spodoptera exigua were studied. alanine was used to replace single residues in loops 2 and 3 of domain ii (mutant ppb19) and to replace residues 541-544 in domain iii (mutant ppb20). additionally, a cry1ca mutant combining all mutations was constructed (mutant ppb21). toxicity assays showed a marked decrease in toxicity against s. exigua for all mutants, while they retained their activity ...200415320864
seasonal pattern of abundance of aedes aegypti (diptera: culicidae) in buenos aires city, argentina.in buenos aires, the most crowded city of argentina, there is a potential risk of dengue virus transmission by the mosquito aedes aegypti during late summer. the temporal patterns of oviposition activity and abundance of breeding sites of this vector were studied in two cemeteries of the city. between september 1998 and august 1999, we examined 142 ovitraps weekly and a total of 18,010 water-filled containers. both study areas showed remarkable differences in the percentages of positive ovitraps ...200415322622
a conserved domain of alkaline phosphatase expression in the malpighian tubules of dipteran insects.malpighian (renal) tubules are key components of the insect osmoregulatory system and show correspondingly great diversity in both number and length. recently, the organisation of the drosophila melanogaster tubule has been elucidated by enhancer trapping, and an array for functional properties has been shown to align with the functional domains. in drosophila, there is a lower tubule domain, which coincides with expression of alkaline phosphatase and delineates the absorptive region of the tubu ...200415326206
genetic relationships and evolution of genotypes of yellow fever virus and other members of the yellow fever virus group within the flavivirus genus based on the 3' noncoding region.genetic relationships among flaviviruses within the yellow fever (yf) virus genetic group were investigated by comparing nucleotide sequences of the 3' noncoding region (3'ncr). size heterogeneity was observed between members and even among strains of the same viral species. size variation between yf strains was due to duplications and/or deletions of repeated nucleotide sequence elements (ryf). west african genotypes had three copies of the ryf (ryf1, ryf2, and ryf3); the angola and the east an ...200415331698
a single amino acid substitution in the envelope protein of chimeric yellow fever-dengue 1 vaccine virus reduces neurovirulence for suckling mice and viremia/viscerotropism for monkeys.a chimeric yellow fever-dengue 1 (chimerivax-den1) virus was produced by the transfection of vero cells with chimeric in vitro rna transcripts. the cell culture supernatant was subjected to plaque purification for the identification of a vaccine candidate without mutations. of 10 plaque-purified clones, 1 containing no mutation (clone j) was selected for production of the vaccine virus. during subsequent cell culture passaging of this clone for vaccine production, a single amino acid substitutio ...200415331733
function-informed transcriptome analysis of drosophila renal tubule.comprehensive, tissue-specific, microarray analysis is a potent tool for the identification of tightly defined expression patterns that might be missed in whole-organism scans. we applied such an analysis to drosophila melanogaster malpighian (renal) tubule, a defined differentiated tissue.200415345053
critical review of the vector status of aedes albopictus.the mosquito aedes (stegomyia) albopictus (skuse) (diptera: culicidae), originally indigenous to south-east asia, islands of the western pacific and indian ocean, has spread during recent decades to africa, the mid-east, europe and the americas (north and south) after extending its range eastwards across pacific islands during the early 20th century. the majority of introductions are apparently due to transportation of dormant eggs in tyres. among public health authorities in the newly infested ...200415347388
laboratory and field evaluation of teknar hp-d, a biolarvicidal formulation of bacillus thuringiensis ssp. israelensis, against mosquito vectors.larvicidal efficacy of teknar hp-d, an improved biolarvicidal formulation of bacillus thuringiensis ssp. israelensis (bti), against anopheles stephensi, culex quinquefasciatus and aedes aegypti was determined in the laboratory, and in field the efficacy of the formulation was tested against cx. quinquefasciatus breeding in cesspits, unused wells and drains. the toxicity of the formulation to gambusia affinis (larvivorous fish), notonecta sp. and diplonychus indicus (water bugs) was also evaluate ...200415350862
experimental evaluation of the relationship between lethal or non-lethal virulence and transmission success in malaria parasite infections.evolutionary theory suggests that the selection pressure on parasites to maximize their transmission determines their optimal host exploitation strategies and thus their virulence. establishing the adaptive basis to parasite life history traits has important consequences for predicting parasite responses to public health interventions. in this study we examine the extent to which malaria parasites conform to the predicted adaptive trade-off between transmission and virulence, as defined by morta ...200415355551
[evaluation of an educational module on dengue and aedes aegypti for schoolchildren in honduras].to evaluate the effectiveness of a special course on environmental health and dengue, given to primary school students and intended to promote behavioral changes in the mothers of those students that would lead to the safe handling of water, adequate disposal of trash, and control of household breeding sites of aedes aegypti, the mosquito vector for dengue.200415357933
[evaluation of the impact on aedes aegypti infestation in cement tanks of the municipal district of canindé, ceará, brazil after using the betta splendens fish as an alternative biological control].canindé has a population of 71,235 inhabitants. in april 2001, the city started using larvivorous fish in cement water tanks, as a means of biological control of aedes aegypti larvae. during house-to-house visits by health agents, instead of treating the water tank with larvicide, a betta splendens fish was introduced into each tank. the number of houses and the number of tanks was estimated by monthly surveys. then, the number of tanks per house was determined. taking into account this estimate ...200415361957
the logistic model for predicting the non-gonoactive aedes aegypti females.to estimate, using logistic regression, the likelihood of occurrence of a non-gonoactive aedes aegypti female, previously fed human blood, with relation to body size and collection method.200415368866
a potentially functional mariner transposable element in the protist trichomonas vaginalis.mariner transposable elements encoding a d,d34d motif-bearing transposase are characterized by their pervasiveness among, and exclusivity to, animal phyla. to date, several hundred sequences have been obtained from taxa ranging from cnidarians to humans, only two of which are known to be functional. related transposons have been identified in plants and fungi, but their absence among protists is noticeable. here, we identify and characterize tvmar1, the first representative of the mariner family ...200515371525
some basic biological characteristics of the vector, aedes aegypti, responsible for dengue virus transmission. 200415379084
densonucleosis virus purification by ion exchange membranes.preparative chromatography is widely used in the downstream purification of biopharmaceutical products. replacement of resins by membranes as chromatographic supports, overcomes many of the limitations associated with resin-based chromatography such as high-pressure drops, slow processing rates due to pore diffusion and channeling of the feed through the bed. in particular, adsorptive membranes may be ideally suited for virus capture. virus capture is critical in a number of applications. in gen ...200415384051
arrest of development of plasmodium gallinaceum in mosquitoes (aedes aegypti) by radiation effect of p32 1,2. 195015424666
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 ...200215455049
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 ...200215455055
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 ...200215455059
a single gene (yes) controls pigmentation of eyes and scales in heliothis virescens.a yellow-eyed mutant was discovered in a strain of heliothis virescens, the tobacco budworm, that already exhibited a mutation for yellow scale, y. we investigated the inheritance of these visible mutations as candidate markers for transgenesis. yellow eye was controlled by a single, recessive, autosomal factor, the same type of inheritance previously known for y. presence of the recombinant mutants with yellow scales and wild type eyes in test crosses indicated independent segregation of genes ...200115455061
distribution of ovary ecdysteroidogenic hormone i in the nervous system and gut of mosquitoes.ovary ecdysteroidogenic hormone i (oeh i) is a gonadotropin in the female mosquito, aedes aegypti. whole-mount immunocytochemistry using oeh i antisera revealed an extensive distribution of immunostained cells in larvae and adults of this mosquito comparable to that observed in the african malaria mosquito, anopheles gambiae. medial neurosecretory cells were stained in brains of larvae and adult ae. aegypti. in an gambiae the lateral neurosecretory cells were stained more often. in both species, ...200115455063
characterization of an endogenous gene expressed in aedes aegypti using an orally infectious recombinant sindbis virus.sindbis virus expression vectors have been used successfully to express and silence genes of interest in vivo in several mosquito species, including aedes aegypti, ae. albopictus, ae. triseriatus,culex pipiens, armigeres subalbatus and anopheles gambiae. here we describe the expression of an endogenous gene, defensin, in ae. aegypti using the orally infectious sindbis virus, mre/3'2j expression vector. we optimized conditions to infect mosquito larvae per os using c6/36ae. albopictus cells infec ...200115455070
vaccine candidates derived from a novel infectious cdna clone of an american genotype dengue virus type 2.a dengue virus type 2 (den-2 tonga/74) isolated from a 1974 epidemic was characterized by mild illness and belongs to the american genotype of den-2 viruses. to prepare a vaccine candidate, a previously described 30 nucleotide deletion (delta30) in the 3' untranslated region of den-4 has been engineered into the den-2 isolate.200415461822
the role of hemagglutinins in the midgut extracts of two lines of aedes aegypti in their susceptibility to dengue-2 virus.hemagglutinin activity (ha) was studied in the midgut extracts from highly (h) and lowly susceptible strains of aedes aegypti mosquitoes to dengue-2 virus (den-2). ha in the midgut extracts from these two isofemale strains of mosquitoes was high in as compared to (h) mosquitoes. ha was found to be higher with chicken red blood cells (rbcs) than with rabbit and human rbcs of o group. larval midgut extracts showed higher activity than those from adult female mosquitoes. exposure of midgut extracts ...200415462286
satellite dna from the y chromosome of the malaria vector anopheles gambiae.satellite dna is an enigmatic component of genomic dna with unclear function that has been regarded as "junk." yet, persistence of these tandem highly repetitive sequences in heterochromatic regions of most eukaryotic chromosomes attests to their importance in the genome. we explored the anopheles gambiae genome for the presence of satellite repeats and identified 12 novel satellite dna families. certain families were found in close juxtaposition within the genome. six satellites, falling into t ...200515466420
aromaticity of tyr-202 in the alpha4-alpha5 loop is essential for toxicity of the bacillus thuringiensis cry4a toxin.the current model for the mechanism of action of the bacillus thuringiensis cry delta-endotoxins involves the penetration of the alpha4-alpha5 hairpin into the target midgut epithelial cell membranes, followed by pore formation. in this study, pcr-based mutagenesis was employed to identify a critical residue within the alpha4-alpha5 loop of the 130kda cry4a mosquito-larvicidal protein. alanine-substitutions of two charged (asp-198 and asp-200) and four polar (asn-190, asn-195, tyr-201 and tyr-20 ...200415469709
comparative larvicidal toxicities of three ecdysone agonists on the mosquitoes aedes aegypti, culex quinquefasciatus, and anopheles gambiae.ecdysone agonists are hormonally active insect growth regulators that disrupt development of pest insects and have potential for development as insecticides. their effects have been particularly well-studied in lepidoptera and coleoptera, but significantly less is known about their effects on dipterans, particularly aquatic species. the potency of three ecdysone agonists on larvae of 3 mosquito species, aedes aegypti, anopheles gambiae, and culex quinquefasciatus, was examined. anopheles gambiae ...200415484259
[epidemiological characteristics of dengue in the municipality of são luís, maranhão, brazil, 1997-2002].a total of 12,008 cases of dengue were reported from 1997 to 2002, with peaks in 1997 (35.8%) and 1998 (45.8%). the disease predominated in the 15-49-year age group (72.2%) and during the rainy season (83.3%), showing a positive correlation with the amount of rainfall (r = 0.84) and relative humidity (r = 0.76) and a negative correlation with temperature (r = -0.78). there was no significant difference (chi2 = 2.319; p > 0.05) in the number of cases in males (49%) and females (51%). dengue was d ...200415486688
yellow fever: the recurring plague.despite the availability of a safe and efficacious vaccine, yellow fever (yf) remains a disease of significant public health importance, with an estimated 200,000 cases and 30,000 deaths annually. the disease is endemic in tropical regions of africa and south america; nearly 90% of yf cases and deaths occur in africa. it is a significant hazard to unvaccinated travelers to these endemic areas. virus transmission occurs between humans, mosquitoes, and monkeys. the mosquito, the true reservoir of ...200415487593
a preliminary study of multilevel geographic distribution & prevalence of aedes aegypti (diptera: culicidae) in the state of goa, india.dengue virus activity has never been reported in the state of goa. the present study was carried out to document a multilevel geographic distribution, prevalence and preliminary analysis of risk factors for the invasions of aedes aegypti in goa.200415489555
incomplete surveillance of a dengue-2 epidemic in ibagué, colombia, 1995-1997.from april 1995 through november 1997 a dengue epidemic occurred in ibagué (400,000 population), colombia, where 3,419 cases were reported and den 2 virus was isolated from seven patients. a sero-survey conducted in 1996 found evidence of previous dengue infection in 9.6% of the population, indicating that many infections had not been reported. the dengue infections occurred in all age groups, but children under five years of age were most frequently infected. forty-five percent of this ibagué p ...200415495597
genetic divergence and dispersal of yellow fever virus, brazil.an analysis of 79 yellow fever virus (yfv) isolates collected from 1935 to 2001 in brazil showed a single genotype (south america i) circulating in the country, with the exception of a single strain from rondonia, which represented south america genotype ii. brazilian yfv strains have diverged into two clades; an older clade appears to have become extinct and another has become the dominant lineage in recent years. pairwise nucleotide diversity between strains ranged from 0% to 7.4%, while amino ...200415498159
yellow fever virus infectivity for bolivian aedes aegypti mosquitoes.the absence of urban yellow fever virus (yfv) in bolivian cities has been attributed to the lack of competent urban mosquito vectors. experiments with aedes aegypti from santa cruz, bolivia, demonstrated infection (100%), dissemination (20%), and transmission of a bolivian yfv strain (cenetrop-322).200415498171
yellow fever outbreak, southern sudan, 2003.in may 2003, an outbreak of fatal hemorrhagic fever, caused by yellow fever virus, occurred in southern sudan. phylogenetic analysis showed that the virus belonged to the east african genotype, which supports the contention that yellow fever is endemic in east africa with the potential to cause large outbreaks in humans.200415498174
acinetobacter baumannii in human body louse.while we were isolating bartonella quintana from body lice, 40 acinetobacter baumannii strains were also isolated and genotyped. one clone was unique and the other was ampicillin susceptible. a. baumannii dna was later detected in 21% of 622 lice collected worldwide. these findings show an a. baumannii epidemic in human body lice.200415498175
conservation of capa peptide-induced nitric oxide signalling in diptera.in d. melanogaster malpighian (renal) tubules, the capa peptides stimulate production of nitric oxide (no) and guanosine 3', 5'-cyclic monophosphate (cgmp), resulting in increased fluid transport. the roles of no synthase (nos), no and cgmp in capa peptide signalling were tested in several other insect species of medical relevance within the diptera (aedes aegypti, anopheles stephensi and glossina morsitans) and in one orthopteran out-group, schistocerca gregaria. nos immunoreactivity was detect ...200415498959
[susceptibility of aedes aegypti larvae to the insecticide temephos in the federal district, brazil].to study the susceptibility status of aedes aegypti to the organophosphate insecticide temephos.200415499431
[tyrophagus putrescentiae predating adult insects of aedes aegypti and aedes albopictus in laboratory].the present study aimed at identifying a mite infesting a colony of aedes aegypti and ae. albopictus as well as investigating the source of infestation. the mite species was identified after it was mounted on slides in hoyer's medium and examined under an optical microscope. it showed to be tyrophagus putrescentiae. fish and rabbit food samples were kept in an environmental chamber at 27 degrees c and 90% humidity for 21 days and were weekly examined. the presence of t. putrescentiae was only ob ...200415499448
control of aedes aegypti with temephos in a buenos aires cemetery, argentina.the efficacy of a larvicide, temephos, for controlling ae. aegypti was evaluated in a cemetery in buenos aires, argentina. breeding sites decreased from 18.4% in the first study period (nov 1998 to may 1999, without temephos) to 2.2% in the second period (nov 1999 to may 2000, two applications), and to 0.05% in the third one (nov 2000 to may 2001, five applications). ovitraps with eggs decreased from 17% in the first period to 5.8% in the second period, and to 2.9% in the third one. results sugg ...200415499449
dengue emergence and adaptation to peridomestic mosquitoes.phylogenetic evidence suggests that endemic and epidemic dengue viruses (denv), transmitted among humans by the anthropophilic mosquitoes aedes aegypti and ae. albopictus, emerged when ancestral, sylvatic denv transmitted among nonhuman primates by sylvatic aedes mosquitoes adapted to these peridomestic vectors. we tested this hypothesis by retrospectively examining evidence for adaptation of epidemic and endemic versus sylvatic strains of denv-2 to ae. albopictus and ae. aegypti. first and seco ...200415504265
serotype-specific entry of dengue virus into liver cells: identification of the 37-kilodalton/67-kilodalton high-affinity laminin receptor as a dengue virus serotype 1 receptor.dengue virus, the causative agent of dengue fever, dengue shock syndrome, and dengue hemorrhagic fever, infects susceptible cells by initially binding to a receptor(s) located on the host cell surface. evidence to date suggests that receptor usage may be cell and serotype specific, and this study sought to identify dengue virus serotype 1 binding proteins on the surface of liver cells, a known target organ. by using a virus overlay protein binding assay (vopba), in both nondenaturing and denatur ...200415507651
study of sequence variation of dengue type 3 virus in naturally infected mosquitoes and human hosts: implications for transmission and evolution.dengue virus is an arbovirus that replicates alternately in the mosquito vector and human host. we investigated sequences of dengue type 3 virus in naturally infected aedes aegypti mosquitoes and in eight patients from the same outbreak and reported that the extent of sequence variation seen with the mosquitoes was generally lower than that seen with the patients (mean diversity, 0.21 versus 0.38% and 0.09 versus 0.23% for the envelope [e] and capsid [c] genes, respectively). this was further ve ...200415507664
nosocomial transmission of dengue. 200415515246
population dynamics of aedes aegypti from a dengue hyperendemic urban setting in colombia.this study evaluated if the aedes aegypti population in the city of cali, colombia was composed of genetically distinct local populations with different levels of insecticide resistance and dengue vector competence. insecticide resistance was assayed biochemically and was associated with varying levels of mixed-function oxidases and non-specific esterases. the genes encoding those enzymes were under selective pressure from insecticides used to suppress ae. aegypti populations. vector competence ...200415516650
molecular differentiation of colonized human malaria vectors by 28s ribosomal dna polymorphisms.anopheles gambiae s.s. giles, an. stephensi liston, an. freeborni aitken, and an. quadrimaculatus say are cultured and studied in molecular genetic and transgenic laboratories with increasing frequency. with limited research space, these mosquitoes are often maintained in the same insectary. under these conditions, cross-contamination of colonies can occur and have devastating consequences to affected research programs. we have developed a polymerase chain reaction-based assay targeting the 28s ...200415516651
new insecticidal amides from petroleum ether extract of dried piper nigrum l. whole fruits.the petroleum ether extract of dried ground whole fruits of piper nigrum l. afforded 20 compounds (1-20) including two new insecticidal amides named as pipnoohine (1), and pipyahyine (2), seven reported for the first time from this plant (12, 13, 15-17, 19, 20), and eleven known compounds (3-11, 14, 18). the structure of 1 has been elucidated as (2e,4e,12z)-n-(4-methylpentyl)octadeca-2,4,12-trienamide and that of 2 as (2e,4e,11e)-12-(benzo[1,3]dioxol-5-yl)-n-(3-methylbutyl)dodeca-2,4,11-trien-am ...200415516761
essential role of membrane-attack protein in malarial transmission to mosquito host.after ingestion of infected blood by a mosquito, malarial parasites are fertilized in the mosquito midgut and develop into motile ookinetes. these ookinetes invade epithelial cells by rupturing the cell membrane and migrate through the cytoplasm toward the basal lamina, on which they develop to oocysts. here we report that a microneme protein with a membrane-attack complex and perforin (macpf)-related domain, which we name membrane-attack ookinete protein (maop), is produced in the ookinete stag ...200415520375
field- and laboratory-based active dengue surveillance in chennai, tamil nadu, india: observations before and during the 2001 dengue epidemic.dengue cases are reported every year in the city of chennai, tamil nadu, india. since april 2001, longitudinal field- and laboratory-based active dengue surveillance has been carried out in chennai to study dengue trends.200415525913
molecular characterization of brevibacillus laterosporus and its potential use in biological control.thirty-three strains of brevibacillus laterosporus, including three novel strains isolated from brazilian soil samples, were examined for genetic variability by the use of different pcr-based methods. molecular markers that could characterize bacterial strains with regards to their pathogenic potential were investigated. in addition, toxicity was assessed by the use of insects belonging to the orders lepidoptera and coleoptera and the mollusk biomphalaria glabrata. among the targets tested, biom ...200415528531
entomological observations on dengue vector mosquitoes following a suspected outbreak of dengue in certain parts of nagaland with a note on their susceptibility to insecticides.three species of aedes viz., aedes albopictus, aedes aegypti and aedes annandalei were detected from different breeding sources in and around human habitats during entomological study conducted following an outbreak suspected to be of dengue (which occurred during, 1994) in parts of medziphema phc area of nagaland in two different points of time ie., in the year, 1994 and, 2000. the potential dengue vector, aedes albopictus showed high preponderance by breeding in all types of containers searche ...200415529881
repellency of aerosol and cream products containing fennel oil to mosquitoes under laboratory and field conditions.the repellency of fennel (foeniculum vulgare miller)-containing products (5% aerosol and 8% cream) against mosquitoes was compared with those of citronella oil, geranium oil and deet, as well as three commercial repellents, baby keeper cream containing ir3535, meimei cream containing citronella and geranium oils, and repellan s aerosol containing 19% n,n-diethyl-m-toluamide (deet) under laboratory and field conditions. in a laboratory study with female aedes aegypti (l), fennel oil exhibited goo ...200415532688
larvicidal persistence of formulations of bacillus thuringiensis var. israelensis to control larval aedes aegypti.after detection of resistance to the organophosphate temephos in populations of aedes aegypti in brazil, corncob granule (cg) and water-dispersible granule (wdg) formulations of bacillus thuringiensis var. israelensis (bti) were introduced in routine focal treatments. larvicidal persistence and the influence of exposure to sunlight on vectobac formulations of bti were compared in 250-liter fiberglass water containers. production of pupal ae. aegypti in containers was used to indicate control. in ...200415532933
experimental detection of rift valley fever virus by reverse transcription-polymerase chain reaction assay in large samples of mosquitoes.a reverse transcription-polymerase chain reaction (rt-pcr) was assessed in laboratory tests to detect the presence of single aedes aegypti (l.) or eretmapodites quinquevittatus theobald mosquitoes infected with rift valley fever virus in pools of mosquitoes, 50-600 in size, from laboratory colonies or mixed field collections. the viral rna was detected in all pools containing infected mosquitoes and was shown to be as sensitive as infant mice but more sensitive than vero cell cultures for virus ...200015535594
synergy between toxins of bacillus thuringiensis subsp. israelensis and bacillus sphaericus.synergistic interactions among the multiple endotoxins of bacillus thuringiensis subsp. israelensis de barjac play an important role in its high toxicity to mosquito larvae and the absence of insecticide resistance in populations treated with this bacterium. a lack of toxin complexity and synergism are the apparent causes of resistance to bacillus sphaericus neide in particular culex field populations. to identify endotoxin combinations of the two bacillus species that might improve insecticidal ...200415535624
susceptibility of urban and rural populations of aedes albopictus from são paulo state, brazil, to infection by dengue-1 and -2 viruses.in brazil, dengue viruses (denv) are transmitted by aedes aegypti (l.). however, the recent introduction of aedes albopictus (skuse) has caused concern, because some populations of this species also are capable of denv transmission. ae. albopictus from rural and urban localities of são paulo state, brazil, were artificially exposed to infection with denv-1 and -2 to evaluate their susceptibility. the rates of infection (6.2 and 5.7% for denv-1; 5.3 and 12% for denv-2) and dissemination (22.2 and ...200415535628
immune responses to mosquito saliva in 14 individuals with acute systemic allergic reactions to mosquito bites.mosquito bite-induced acute systemic allergic reactions are an increasing clinical concern and have not been optimally characterized immunologically.200415536430
saliva of the yellow fever mosquito, aedes aegypti, modulates murine lymphocyte function.saliva of many vector arthropods contains factors that inhibit haemostatic responses in their vertebrate hosts. less is known about the effect of vector saliva on host immune responses. we investigated the effect of aedes aegypti salivary gland extracts on antigen-stimulated responses of transgenic ova-tcr do11 mouse splenocytes in vitro. t-cell proliferation was inhibited in a dose-dependent manner, with greater than 50% inhibition at 0.3 salivary gland pair (sgp) equivalents/ml. lps-stimulated ...200415541033
weather-based prediction of plasmodium falciparum malaria in epidemic-prone regions of ethiopia i. patterns of lagged weather effects reflect biological mechanisms.malaria epidemics due to plasmodium falciparum are reported frequently in the east african highlands with high case fatality rates. there have been formal attempts to predict epidemics by the use of climatic variables that are predictors of transmission potential. however, little consensus has emerged about the relative importance and predictive value of different factors. understanding the reasons for variation is crucial to determining specific and important indicators for epidemic prediction. ...200415541174
chimpanzee fab fragments and a derived humanized immunoglobulin g1 antibody that efficiently cross-neutralize dengue type 1 and type 2 viruses.passive immunization with monoclonal antibodies from humans or nonhuman primates represents an attractive alternative to vaccines for prevention of illness caused by dengue viruses (denv) and other flaviviruses, including the west nile virus. in a previous study, repertoire cloning to recover fab fragments from bone marrow mrna of chimpanzees infected with all four denv serotypes (dengue virus serotype 1 [denv-1] to denv-4) was described. in that study, a humanized immunoglobulin g1 (igg1) antib ...200415542643
evaluation of mesocyclops annulatus (copepoda: cyclopoidea) as a control agent of aedes aegypti (diptera: culicidae) in argentina.we evaluated the potential of mesocyclops annulatus as a control agent of aedes aegypti in la plata city (argentina). mosquito larval survivorship due to predation by these copepods was estimated at weekly intervals during the oviposition period of a. aegypti. mean weekly a. aegypti larval survivorship in cylindrical plastic containers (12 cm height and 11 cm diameter) with copepods was significantly lower than in control containers. furthermore, weekly larval survival was negatively correlated ...200415543420
larvicidal activity of essential oils from brazilian plants against aedes aegypti l.aedes aegypti l. is the major vector of dengue fever, an endemic disease in brazil. in an effort to find effective and affordable ways to control this mosquito, the larvicidal activities of essential oils from nine plants widely found in the northeast of brazil were analyzed by measurement of their lc50. the essential oils were extracted by steam distillation and their chemical composition determined by gl-chromatography coupled to mass spectroscopy. the essential oils from cymbopogon citratus a ...200415543421
the role of phenylalanine hydroxylase in melanotic encapsulation of filarial worms in two species of mosquitoes.melanin formation has a significant influence on mosquito vector competence by limiting the development of metazoan parasites. tyrosine, the rate-limiting substrate of melanin production, can be obtained exogenously or derived from phenylalanine by phenylalanine hydroxylase (pah). the characteristics of this defense mechanism, such as temporal expression of constituent enzymes involved in the biosynthetic pathway, can vary considerably between mosquito species. we investigated the functional rol ...200415544946
an active transposable element, herves, from the african malaria mosquito anopheles gambiae.transposable elements have proven to be invaluable tools for genetically manipulating a wide variety of plants, animals, and microbes. some have suggested that they could be used to spread desirable genes, such as refractoriness to plasmodium infection, through target populations of anopheles gambiae, thereby disabling the mosquito's ability to transmit malaria. to achieve this, a transposon must remain mobile and intact after the initial introduction into the genome. endogenous, active class ii ...200515545643
weather-based prediction of plasmodium falciparum malaria in epidemic-prone regions of ethiopia ii. weather-based prediction systems perform comparably to early detection systems in identifying times for interventions.timely and accurate information about the onset of malaria epidemics is essential for effective control activities in epidemic-prone regions. early warning methods that provide earlier alerts (usually by the use of weather variables) may permit control measures to interrupt transmission earlier in the epidemic, perhaps at the expense of some level of accuracy.200415555061
characterization of a defensin from the sand fly phlebotomus duboscqi induced by challenge with bacteria or the protozoan parasite leishmania major.antimicrobial peptides are major components of the innate immune response of epithelial cells. in insect vectors, these peptides may play a role in the control of gut pathogens. we have analyzed antimicrobial peptides produced by the sand fly phlebotomus duboscqi, after challenge by injected bacteria or feeding with bacteria or the protozoan parasite leishmania major. a new hemolymph peptide with antimicrobial activity was identified and shown to be a member of the insect defensin family. intere ...200415557638
association of human leukocyte antigen dq1 and dengue fever in a white southern brazilian population.dengue is an infectious disease of viral etiology transmitted by the mosquitoes aedes aegypti, a. albopictus, and a. scutellaris. it can develop either as a benign form or as a severe hemorrhagic form. previous work showed an association of the hemorrhagic form with human leukocyte antigens (hla), suggesting a role of genetic factors in disease susceptibility. nevertheless, data on hla association with the classical form of the disease is scarce in literature. sixty-four patients and 667 normal ...200415558162
freeze-fracture and immunogold analysis of aquaporin-4 (aqp4) square arrays, with models of aqp4 lattice assembly.each day, approximately 0.5-0.9 l of water diffuses through (primarily) aquaporin-1 (aqp1) channels in the human choroid plexus, into the cerebrospinal fluid of the brain ventricles and spinal cord central canal, through the ependymal cell lining, and into the parenchyma of the cns. additional water is also derived from metabolism of glucose within the cns parenchyma. to maintain osmotic homeostasis, an equivalent amount of water exits the cns parenchyma by diffusion into interstitial capillarie ...200415561408
susceptibility of two different strains of aedes aegypti (diptera: culicidae) to plant oils.the toxicity of 11 oils extracted from plants commonly grown in the himalayan region was studied using larvae of two aedes aegypti (l.) strains. a strain from liverpool, england, was highly susceptible to these oils. the lc50 values were much higher in a local laboratory strain. daucus carota l. oil was highly toxic in both strains. differences in the susceptibility of these strains to the action of the test oils and their potential use in integrated pest management are discussed.200415568366
a gpi-linked carbonic anhydrase expressed in the larval mosquito midgut.we have previously described the first cloning and partial characterization of carbonic anhydrase from larval aedes aegypti mosquitoes. larval mosquitoes utilize an alkaline digestive environment in the lumen of their anterior midgut, and we have also demonstrated a critical link between alkalization of the gut and carbonic anhydrase(s). in this report we further examine the nature of the previously described carbonic anhydrase and test the hypothesis that its pattern of expression is consistent ...200415579552
functional characterisation of the anopheles leucokinins and their cognate g-protein coupled receptor.identification of the anopheles gambiae leucokinin gene from the completed a. gambiae genome revealed that this insect species contains three leucokinin peptides, named anopheles leucokinin i-iii. these peptides are similar to those identified in two other mosquito species, aedes aegypti and culex salinarius. additionally, anopheles leucokinin i displays sequence similarity to drosophila melanogaster leucokinin. using a combination of computational and molecular approaches, a full-length cdna fo ...200415579553
population genetic structure of anopheles gambiae mosquitoes on lake victoria islands, west kenya.understanding the genetic structure of island anopheles gambiae populations is important for the current tactics in mosquito control and for the proposed strategy using genetically-modified mosquitoes (gmm). genetically-isolated mosquito populations on islands are a potential site for testing gmm. the objective of this study was to determine the genetic structure of a. gambiae populations on the islands in lake victoria, western kenya.200415581429
rna interference acts as a natural antiviral response to o'nyong-nyong virus (alphavirus; togaviridae) infection of anopheles gambiae.rna interference (rnai) is triggered in eukaryotic organisms by double-stranded rna (dsrna), and it destroys any mrna that has sequence identity with the dsrna trigger. the rnai pathway in anopheles gambiae can be silenced by transfecting cells with dsrna derived from exon sequence of the a. gambiae argonaute2 (agago2) gene. we hypothesized that rnai may also act as an antagonist to alphavirus replication in a. gambiae because rna viruses form dsrna during replication. silencing agago2 expressio ...200415583140
the early gene broad is involved in the ecdysteroid hierarchy governing vitellogenesis of the mosquito aedes aegypti.the broad (br) gene, encoding a family of c2h2 type zinc-finger dna-binding proteins, has been shown to act as a crucial member of the 20-hydroxyecdysone (20e) regulatory hierarchy in the fruitfly, drosophila melanogaster and the moth, manduca sexta. in this study, we have shown that the br gene is involved in the 20e-regulatory hierarchy controlling vitellogenesis in the mosquito, aedes aegypti. unlike e74 and e75 early genes, expression of br was activated in previtellogenic females, during a ...200415591032
temporal and geographic patterns of aedes aegypti (diptera: culicidae) production in iquitos, peru.large-scale longitudinal cohort studies are necessary to characterize temporal and geographic variation in aedes aegypti (l.) (diptera: culicidae) production patterns and to develop targeted dengue control strategies that will reduce disease. we carried out pupal/demographic surveys in a circuit of approximately 6,000 houses, 10 separate times, between january 1999 and august 2002 in the amazonian city of iquitos, peru. we quantified the number of containers positive for ae. aegypti larvae and/o ...200415605653
quantitative trait loci affecting dengue midgut infection barriers in an advanced intercross line of aedes aegypti.quantitative trait loci (qtl) affecting the ability of the aedes aegypti midgut to become infected with dengue 2 virus (den2) were mapped in the f5 generation of an advanced intercross line (ail). a strain of ae. aegypti previously selected for den2 susceptibility was crossed to a new strain selected for refractoriness to midgut infection. in p1 and f1 parents and 147 f5 offspring, genotypes at forty-four cdna loci were analysed. a new sex linked qtl and a second qtl on chromosome ii with genoty ...200415606812
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