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spectral sensitivity of larval mosquito ocelli.the spectral sensitivity of lateral ocelli in both wild-type and white-eyed larvae of the yellow fever mosquito aedes aegypti l. (reared in darkness) was measured by means of the electroretinogram. the spectral sensitivity is maximal at about 520 nm, with a small secondary peak near 370 nm. when allowance is made for some screening and filtering by the eye tissues, the spectral sensitivity is in reasonable agreement with the absorption spectrum of ocellar rhodopsin (lambda(max) = 515 nm).05029552
rhodopsin of the larval mosquito.larvae of the mosquito aedes aegypti have a cluster of four ocelli on each side of the head. the visual pigment of each ocellus of mosquitoes reared in darkness was characterized by microspectrophotometry, and found to be the same. larval mosquito rhodopsin (lambda(max) = 515 nm) upon short irradiation bleaches to a stable photoequilibrium with metarhodopsin (lambda(max) = 480 nm). on long irradiation of glutaraldehyde-fixed tissues or in the presence of potassium borohydride, bleaching goes fur ...05029551
glutathione biosynthesis in the aging adult yellow-fever mosquito [aedes aegypti (louisville)].our previous findings [hazelton & lang (1978) fed. proc. fed. am. soc. exp. biol. 37(6), 2378 (abstr.)] demonstrated a senescence-specific decrease in glutathione (gsh) concentration in the yellow-fever mosquito aedes aegypti (louisville)]. as a possible mechanism for this change, gsh biosynthesis was investigated in adult mosquitoes of different ages through the life-span. biosynthesis was measured as the incorporation rate of [14c]glycine or [14c]cystine into glutathione. essential information ...06860301
the ovary as a source of alpha-ecdysone in an adult mosquito.the ovaries of the mosquito aedes aegypti cultured in vitro secrete material that behaves like ecdysone in a radioimmunoassay. the material was identified as alpha-ecdysone by high-resolution liquid and gas-liquid chromatography. secretion reached a maximum 16 hr after a blood meal as shown by bioassay and direct determination. ovariectomy reduced the concentration of ecdysone in the adult after a blood meal. qualitative analysis of whole-body extracts indicated beta-ecdysone to be the principal ...01059110
diminution and enlargement of the mosquito rhabdom in light and darkness.the rhabdoms of the larval ocelli of the mosquito aedes aegypti undergo morphological light and dark adaptation over periods of hours. the rhabdom enlarges during dark adaptation and grows smaller during light adaptation. diminution is exponential, enlargement linear, and rates of change are proportional to log light intensity. rhabdoms maintained at a constant intensity level off at a constant volume proportional to log intensity. we argue that changes in rhabdom volume after changes in light i ...01176940
ecdysone-mediated stimulation of dopa decarboxylase activity and its relationship to ovarian development in aedes aegypti.very little dopa decarboxylase activity is detectable in adult female mosquitoes aedes aegypti which have not been allowed to engorge blood. however, when such females are injected with the molting hormone beta-ecdysone a marked stimulation of this enzyme's activity is observable. no stimulation is observed in males similarly injected, nor in females injected with cholesterol or a juvenile hormone mimic. in addition, ecdysone injection initiates ovarian development in these anautogenous non-bloo ...04827909
an extraovarian protein accumulated in mosquito oocytes is a carboxypeptidase activated in embryos.we report a phenomenon previously unknown for oviparous animals; in aedes aegypti mosquitoes a serine carboxypeptidase is synthesized extraovarially and then internalized by oocytes. the cdna encoding mosquito vitellogenic carboxypeptidase (vcp) was cloned and sequenced. the vcp cdna hybridizes to a 1.5-kilobase mrna present only in the fat body of vitellogenic females. the deduced amino acid sequence of vcp shares significant homology with members of the serine carboxypeptidase family. binding ...01961751
a lepidopteran orthologue of reaper reveals functional conservation and evolution of iap antagonists.genetic studies in drosophila melanogaster have revealed that inhibitor of apoptosis (iap) proteins and iap antagonists such as reaper play a pivotal role in controlling cell death in insects. interestingly, although the sequences and structures of iaps are highly conserved, the sequence of iap antagonists diverged very rapidly during evolution, making their identification difficult. using a customized bioinformatics approach, we identified an iap antagonist, iap-binding motif 1 (ibm1), from the ...019523066
voltage coupling of primary h+ v-atpases to secondary na+- or k+-dependent transporters.this review provides alternatives to two well established theories regarding membrane energization by h(+) v-atpases. firstly, we offer an alternative to the notion that the h(+) v-atpase establishes a protonmotive force (pmf) across the membrane into which it is inserted. the term pmf, which was introduced by peter mitchell in 1961 in his chemiosmotic hypothesis for the synthesis of atp by h(+) f-atp synthases, has two parts, the electrical potential difference across the phosphorylating membra ...019448072
toxicity of aromatic acids to the larvae of the mosquito aedes aegypti l. and the counteracting influence of amino acids. 014351182
oral delivery of double-stranded rna in larvae of the yellow fever mosquito, aedes aegypti: implications for pest mosquito control.rna interference has already proven itself to be a highly versatile molecular biology tool for understanding gene function in a limited number of insect species, but its widespread use in other species will be dependent on the development of easier methods of double-stranded rna (dsrna) delivery. this study demonstrates that rna interference can be induced in the mosquito aedes aegypti l. (diptera: culicidae) simply by soaking larvae in a solution of dsrna for two hours. the mrna transcripts for ...024224468
chloroquine use improves dengue-related symptoms.dengue is the most important arboviral disease in the world. as chloroquine, an antimalarial agent, has shown some antiviral effects, this study evaluated its effect in patients with dengue. a randomised, double-blind study was performed by administering chloroquine or placebo for three days to 129 patients with dengue-related symptoms. of these patients, 37 were confirmed as having dengue and completed the study; in total, 19 dengue patients received chloroquine and 18 received placebo. there w ...023903975
dengue: "plus ça change, plus c'est la même chose". 024600111
acute gingival bleeding as a complication of dengue hemorrhagic fever.dengue fever is mosquito borne disease caused by dengue virus (denv) of flaviviridae family. the clinical manifestations range from fever to severe hemorrhage, shock and death. here, we report a case of 20-year-old male patient undergoing orthodontic treatment presenting with acute gingival bleeding with a history of fever, weakness, backache, retro orbital pain and ecchymosis over his right arm. the hematological investigations revealed anemia, thrombocytopenia and positive dengue non-structura ...024174736
development associated profiling of chitinase and microrna of helicoverpa armigera identified chitinase repressive microrna.expression of chitinase is developmentally regulated in insects in consonance with their molting process. during the larval-larval metamorphosis in helicoverpa armigera, chitinase gene expression varies from high to negligible. in the five-day metamorphic course of fifth-instar larvae, chitinase transcript is least abundant on third day and maximal on fifth day. microrna library prepared from these highest and lowest chitinase-expressing larval stages resulted in isolation of several mirnas. in ...023887392
influence of age and nutritional status on flight performance of the asian tiger mosquito aedes albopictus (diptera: culicidae).the asian tiger mosquito, aedes albopictus, is a competent vector for arboviruses and recently was implicated as the vector of the first autochthonous cases of dengue and chikungunya in southern europe. the objective of this study was to analyze the flight performance of female ae. albopictus of different ages that were starved, sugar-fed, or sugar-fed and blood-fed, using flight mills. after three days of starvation post emergence, females flew an average distance of 0.7 ± 0.5 km in 1.9 ± 1.5 h ...024404384
rna interference in colorado potato beetle: steps toward development of dsrna as a commercial insecticide.colorado potato beetle (cpb) is a notorious pest on potatoes and has a remarkable ability to detoxify plant chemicals and develop resistance against insecticides. dsrna targeting cpb genes could be expressed in potato plants to control this pest. however, previous attempts at introducing transgenic potato plants to control cpb were not highly successful. recent studies showed that feeding dsrna expressed in bacteria works very well to kill cpb. to realize the potential of rnai to control this an ...026705514
she's a femme fatale: low-density larval development produces good disease vectors.two hypotheses for how conditions for larval mosquitoes affect vectorial capacity make opposite predictions about the relationship of adult size and frequency of infection with vector-borne pathogens. competition among larvae produces small adult females. the competition-susceptibility hypothesis postulates that small females are more susceptible to infection and predicts frequency of infection should decrease with size. the competition-longevity hypothesis postulates that small females have low ...025591112
chemical and biological insecticides select distinct gene expression patterns in aedes aegypti mosquito.worldwide evolution of mosquito resistance to chemical insecticides represents a major challenge for public health, and the future of vector control largely relies on the development of biological insecticides that can be used in combination with chemicals (integrated management), with the expectation that populations already resistant to chemicals will not become readily resistant to biological insecticides. however, little is known about the metabolic pathways affected by selection with chemic ...025540155
peripheral olfactory signaling in insects.olfactory signaling is a crucial component in the life history of insects. the development of precise and parallel mechanisms to analyze the tremendous amount of chemical information from the environment and other sources has been essential to their evolutionary success. considerable progress has been made in the study of insect olfaction fueled by bioinformatics- based utilization of genomics along with rapid advances in functional analyses. here we review recent progress in our rapidly emergin ...025584200
the enigmatic reception of deet - the gold standard of insect repellents.repellents are important prophylactic tools for travelers and populations living in endemic areas of malaria, dengue, encephalitis, and other vector-borne diseases. deet is a safe, broad spectrum repellent, which provides complete protection over a long period of time. despite its low cost, more affordable alternatives are highly desirable, particularly for those in endemic areas where cost is an impediment. alternative compounds like ir 3535 and picaridin have been developed using molecular mod ...025530943
evolution of mosquito preference for humans linked to an odorant receptor.female mosquitoes are major vectors of human disease and the most dangerous are those that preferentially bite humans. a 'domestic' form of the mosquito aedes aegypti has evolved to specialize in biting humans and is the main worldwide vector of dengue, yellow fever, and chikungunya viruses. the domestic form coexists with an ancestral, 'forest' form that prefers to bite non-human animals and is found along the coast of kenya. we collected the two forms, established laboratory colonies, and docu ...025391959
making designer mutants in model organisms.recent advances in the targeted modification of complex eukaryotic genomes have unlocked a new era of genome engineering. from the pioneering work using zinc-finger nucleases (zfns), to the advent of the versatile and specific talen systems, and most recently the highly accessible crispr/cas9 systems, we now possess an unprecedented ability to analyze developmental processes using sophisticated designer genetic tools. in this review, we summarize the common approaches and applications of these s ...025336735
shotgun analysis on the peritrophic membrane of the silkworm bombyx mori.the insect midgut epithelium is generally lined with a unique chitin and protein structure, the peritrophic membrane (pm), which facilitates food digestion and protects the gut epithelium. we used gel electrophoresis and mass spectrometry to identify the extracted proteins from the silkworm pm to obtain an in-depth understanding of the biological function of the silkworm pm components. a total of 305 proteins, with molecular weights ranging from 8.02 kda to 788.52 kda and the isoelectric points ...023187007
studies on the post-oviposition blood-feeding behaviour of aedes aegypti (l.) (diptera: culicidae) in the laboratory.the blood-feeding behaviour of the trinidad strain of aedes aegypti was studied, under laboratory conditions, using one female per cage and monitoring blood feeding immediately, 12, and 24 hours after oviposition. to get large numbers of females that had newly completed their first gonotrophic cycle, the diel oviposition periodicity was conducted using single females per cage and monitoring at 2-hour intervals. the diel oviposition periodicity showed a small morning peak (8%) during the first 2 ...023265613
silencing of the hsf gene, the transcriptional regulator of a. gambiae male accessory glands, inhibits the formation of the mating plug in mated females and disrupts their monogamous behaviour.discovering the molecular factors that shape the mating behaviour and the fertility of the mosquito anopheles gambiae, the principal vector of human malaria, is regarded as critical to better understand its reproductive success as well as for identifying new leads for malaria control measures. in a. gambiae mating induces complex behavioural and physiological changes in the females, including refractoriness to subsequent mating and induction of egg-laying. in other insects including drosophila a ...023265612
efficacy of three formulations of diflubenzuron, an insect growth regulator, against culex quinquefasciatus say, the vector of bancroftian filariasis in india.insect growth regulators (igrs) offer alternatives to conventional chemical larvicides that pose problem of resistance and environmental safety. however, only a limited number of igrs have been approved for use in mosquito control. in the present study, two new formulations of the igr diflubenzuron, 2 per cent granular (gr) and 2 per cent tablet (dt) were tested for its efficacy against culex quinquefasciatus, in comparison to its 25 per cent wettable powder (wp) formulation.023287125
need for an efficient adult trap for the surveillance of dengue vectors.the emergence and re-emergence of arboviral diseases transmitted by aedes aegypti and ae. albopictus continue to be a major threat in the tropics and subtropics. associations between currently used indices and dengue transmission have not been proven to be satisfactorily predictive of dengue epidemics. classical larval indices in dengue surveillance have limited use in assessing transmission risk and are a poor proxy for measuring adult emergence. besides, collection of larval indices is labour ...023287120
seroprevalence of antibodies against chikungunya, dengue, and rift valley fever viruses after febrile illness outbreak, madagascar.in october 2009, two-3 months after an outbreak of a febrile disease with joint pain on the eastern coast of madagascar, we assessed serologic markers for chikungunya virus (chikv), dengue virus (denv), and rift valley fever virus (rvfv) in 1,244 pregnant women at 6 locations. in 2 eastern coast towns, igg seroprevalence against chikv was 45% and 23%; igm seroprevalence was 28% and 5%. igg seroprevalence against denv was 17% and 11%. no anti-denv igm was detected. at 4 locations, 450-1,300 m hig ...023092548
seroprevalence of chikungunya in southern odisha.the emergence of chikungunya (chik) infection was observed in odisha, india in 2006. thereafter many cases with symptoms suggestive of chik were reported from different districts of southern-odisha. this study was aimed to know the seroprevalence, clinical presentations and seasonal trends of chik infection in this region.024479040
effects of the botanical insecticide, toosendanin, on blood digestion and egg production by female aedes aegypti (diptera: culicidae): topical application and ingestion.botanical insecticides offer novel chemistries and actions that may provide effective mosquito control. toosendanin (tsn, 95% purity) is one such insecticide used to control crop pests in china, and in this study, it was evaluated for lethal and sublethal effects on larvae and females of the yellowfever mosquito, aedes aegypti (l.). tsn was very toxic to first instar larvae after a 24 h exposure (lc50 = 60.8 microg/ml) and to adult females up to 96 h after topical treatment (ld50 = 4.3 microg/fe ...023427659
sources of dengue viruses imported into queensland, australia, 2002-2010.to assess risk for importation of dengue virus (denv) into queensland, australia, and sources of imported viruses, we sequenced the envelope region of denv isolates from symptomatic patients with a history of travel during 2002-2010. the number of imported dengue cases greatly increased over the surveillance period, some of which were associated with domestic outbreaks. patients reported traveling to (in order) asia, papua new guinea, pacific island countries, and non-asia-pacific countries. by ...023092682
mathematical models as aids for design and development of experiments: the case of transgenic mosquitoes.we demonstrate the utility of models as aids in the design and development of experiments aimed at measuring the effects of proposed vector population control strategies. we describe the exploration of a stochastic, age-structured model that simulates field cage experiments that test the ability of a female-killing strain of the mosquito aedes aegypti (l.) to suppress a wild-type population. model output predicts that choices of release ratio and population size can impact mean extinction time a ...023270145
gene flow networks among american aedes aegypti populations.the mosquito aedes aegypti, the dengue virus vector, has spread throughout the tropics in historical times. while this suggests man-mediated dispersal, estimating contemporary connectivity among populations has remained elusive. here, we use a large mtdna dataset and a bayesian coalescent framework to test a set of hypotheses about gene flow among american ae. aegypti populations. we assessed gene flow patterns at the continental and subregional (amazon basin) scales. for the americas, our data ...023144654
papaya, dengue fever and ayurveda. 024501439
hemoperitoneum in dengue fever with normal coagulation profile.a 43-year-old male living in bengaluru sought emergency services due to high-grade fever, headache, myalgia, abdominal pain and distension. platelet count (except the first-96,000/mm(3)) and coagulation profile was in normal limits. the dengue serology was positive for igm and ig g (immunoglobulin m and g) antibodies. ultrasound abdomen showed gross ascites, mild bilateral pleural effusion and hepatosplenomegaly. the patient continued to have abdominal pain and progressive distention ascitic tap ...023599615
anopheles nf-κb-regulated splicing factors direct pathogen-specific repertoires of the hypervariable pattern recognition receptor agdscam.insects rely on innate immune responses controlled by the immune deficiency (imd), toll, and other immune signaling pathways to combat infection by a broad spectrum of pathogens. these pathways signal to downstream nf-κb family transcription factors that control specific antipathogen action via direct transcriptional control of immune effectors, hematopoiesis, and melanization. here we show that in the anopheles malaria vector, imd and toll pathways mediate species-specific defenses against plas ...023084919
pyrethroid resistance in aedes aegypti and aedes albopictus from port-au-prince, haiti.in port-au-prince, haiti, the status of insecticide resistance has not recently been evaluated for aedes aegypti (l) and aedes albopictus (skuse) populations. no prophylactics exist for dengue, so prevention is only through vector control methods. an earthquake occurred in haiti on january 12, 2010, with a magnitude of 7.0 mw that devastated the area. dengue became a major concern for the humanitarian relief workers that entered the country. bottle bioassays were conducted in the field on adult ...023181855
lessons from malaria control to help meet the rising challenge of dengue.achievements in malaria control could inform efforts to control the increasing global burden of dengue. better methods for quantifying dengue endemicity-equivalent to parasite prevalence surveys and endemicity mapping used for malaria-would help target resources, monitor progress, and advocate for investment in dengue prevention. success in controlling malaria has been attributed to widespread implementation of interventions with proven efficacy. an improved evidence base is needed for large-sca ...023174383
application of eco-friendly tools and eco-bio-social strategies to control dengue vectors in urban and peri-urban settings in thailand.dengue is considered one of the most important vector-borne diseases in thailand. its incidence is increasing despite routine implementation of national dengue control programmes. this study, conducted during 2010, aimed to demonstrate an application of integrated, community-based, eco-bio-social strategies in combination with locally-produced eco-friendly vector control tools in the dengue control programme, emphasizing urban and peri-urban settings in eastern thailand.023318236
community mobilization and household level waste management for dengue vector control in gampaha district of sri lanka; an intervention study.waste management through community mobilization to reduce breeding places at household level could be an effective and sustainable dengue vector control strategy in areas where vector breeding takes place in small discarded water containers. the objective of this study was to assess the validity of this assumption.023318240
introduction. 023318233
community-based control of aedes aegypti by adoption of eco-health methods in chennai city, india.dengue is highly endemic in chennai city, south india, in spite of continuous vector control efforts. this intervention study was aimed at establishing the efficacy as well as the favouring and limiting factors relating to a community-based environmental intervention package to control the dengue vector aedes aegypti.023318241
estimating dengue vector abundance in the wet and dry season: implications for targeted vector control in urban and peri-urban asia.research has shown that the classical stegomyia indices (or "larval indices") of the dengue vector aedes aegypti reflect the absence or presence of the vector but do not provide accurate measures of adult mosquito density. in contrast, pupal indices as collected in pupal productivity surveys are a much better proxy indicator for adult vector abundance. however, it is unknown when it is most optimal to conduct pupal productivity surveys, in the wet or in the dry season or in both, to inform contr ...023318235
promoting health and advancing development through improved housing in low-income settings.there is major untapped potential to improve health in low-income communities through improved housing design, fittings, materials and construction. adverse effects on health from inadequate housing can occur through a range of mechanisms, both direct and indirect, including as a result of extreme weather, household air pollution, injuries or burns, the ingress of disease vectors and lack of clean water and sanitation. collaborative action between public health professionals and those involved i ...023271143
eco-bio-social research on dengue in asia: a multicountry study on ecosystem and community-based approaches for the control of dengue vectors in urban and peri-urban asia.this article provides an overview of methods and cross-site insights of a 5-year research and capacity building initiative conducted between 2006 and 2011 in six countries of south asia (india, sri lanka) and south-east asia (indonesia, myanmar, philippines, thailand).the initiative managed an interdisciplinary investigation of ecological, biological, and social (i.e., eco-bio-social) dimensions of dengue in urban and peri-urban areas, and developed community-based interventions aimed at reducin ...023318234
genetically modified insects as a public health tool: discussing the different bio-objectification within genetic strategies. 023275331
factors associated with dengue mortality in latin america and the caribbean, 1995-2009: an ecological study.in this study, we aimed to estimate the effect that environmental, demographic, and socioeconomic factors have on dengue mortality in latin america and the caribbean. to that end, we conducted an observational ecological study, analyzing data collected between 1995 and 2009. dengue mortality rates were highest in the caribbean (spanish-speaking and non-spanish-speaking). multivariate analysis through poisson regression revealed that the following factors were independently associated with dengue ...022302870
microsatellite-based parentage analysis of aedes aegypti (diptera: culicidae) using nonlethal dna sampling.to track aedes aegypti (l.) egg-laying behavior in the field in iquitos, peru, we developed methods for 1) sampling dna from live mosquitoes and 2) high through-put parentage analysis using microsatellite markers. we were able to amplify dna extracted from a single hind leg, but not from the pupal exuvia. removal of a leg from teneral females caused no significant changes in female behavioral or life history traits (e.g., longevity, blood feeding frequency, fecundity, egg hatch rate, gonotrophic ...022308775
daily newspaper view of dengue fever epidemic, athens, greece, 1927-1931.during the late summers of 1927 and 1928, a biphasic dengue epidemic affected the athens, greece, metropolitan area; >90% of the population became sick, and >1,000 persons (1,553 in the entire country) died. this epidemic was the most recent and most serious dengue fever epidemic in europe. review of all articles published by one of the most influential greek daily newspapers (i kathimerini) during the epidemic and the years that followed it did not shed light on the controversy about whether th ...022257469
dengue antibodies in blood donors.dengue is an urban arbovirus whose etiologic agent is a virus of the genus flavorius with four distinct antigen serotypes (denv-1, denv-2, denv-3 and denv-4) that is transmitted to humans through the bite of the mosquito aedes aegypti. the campo mourão region in brazil is endemic for dengue fever. obtective: the aim of this study was to evaluate the presence of igg and igm antibodies specific to the four serotypes of dengue in donors of the blood donor service in the city of campo mourão.023049418
the phospholipase c isozymes and their regulation.the physiological effects of many extracellular neurotransmitters, hormones, growth factors, and other stimuli are mediated by receptor-promoted activation of phospholipase c (plc) and consequential activation of inositol lipid signaling pathways. these signaling responses include the classically described conversion of phosphatidylinositol(4,5)p(2) to the ca(2+)-mobilizing second messenger inositol(1,4,5)p(3) and the protein kinase c-activating second messenger diacylglycerol as well as alterat ...022403074
roles of pkc and phospho-adducin in transepithelial fluid secretion by malpighian tubules of the yellow fever mosquito.the diuretic hormone aedeskinin-iii is known to increase the paracellular cl(-) conductance in malpighian (renal) tubules of the mosquito aedes aegypti via a g protein-coupled receptor. the increase serves the blood-meal-initiated diuresis and is associated with elevated levels of ca(2+) and phosphorylated adducin in the cytosol of tubule. in the present study we have cloned adducin in aedes malpighian tubules and investigated its physiological roles. immunolabeling experiments are consistent wi ...024062972
dengue infection: an emerging cause of neuromuscular weakness. 022346179
south-to-north, cross-disciplinary training in global health practice: ten years of lessons learned from an infectious disease field course in jamaica.global commerce, travel, and emerging and resurging infectious diseases have increased awareness of global health threats and opportunities for collaborative and service learning. we review course materials, knowledge archives, data management archives, and student evaluations for the first 10 years of an intensive summer field course in infectious disease epidemiology and surveillance offered in jamaica. we have trained 300 students from 28 countries through collaboration between the university ...021896794
the harmonic convergence of fathers predicts the mating success of sons in aedes aegypti.during courtship males often communicate information about their fitness to females. the matching of harmonic components of flight tone in male-female pairs of flying mosquitoes, or harmonic convergence, was recently described. this behaviour occurs prior to mating and has been suggested to function in mate selection. we investigated the hypothesis that harmonic convergence is a component of mosquito courtship. a key prediction of this hypothesis is that harmonic convergence should provide infor ...022003255
behavioral observations and sound recordings of free-flight mating swarms of ae. aegypti (diptera: culicidae) in thailand.sound plays an important role in the mating behavior of mosquitoes, including aedes aegypti (l). males orient to the fundamental wing beat frequency of females, and both sexes actively modulate their flight tone before mating to converge at harmonic frequencies. the majority of studies on mosquito mating acoustics have been conducted in the laboratory using tethered individuals. in this study, we present the first free-flight recording of naturally forming ae. aegypti swarms in thailand. we desc ...021845959
newer approaches to malaria control.malaria is the third leading cause of death due to infectious diseases affecting around 243 million people, causing 863,000 deaths each year, and is a major public health problem. most of the malarial deaths occur in children below 5 years and is a major contributor of under-five mortality. as a result of environmental and climatic changes, there is a change in vector population and distribution, leading to resurgence of malaria at numerous foci. resistance to antimalarials is a major challenge ...023508211
distributions of competing container mosquitoes depend on detritus types, nutrient ratios, and food availability.coexistence of competitors may result if resources are sufficiently abundant to render competition unimportant, or if species differ in resource requirements. detritus type has been shown to affect interspecific competitive outcomes between aedes albopictus (skuse) and aedes aegypti (l.) larvae under controlled conditions. we assessed the relationships among spatial distributions of detritus types, nutrients, and aquatic larvae of these species in nature. we collected mosquitoes, water, and detr ...022707761
the world of pulmonary vascular disease. 022140619
direct targets of the d. melanogaster dsxf protein and the evolution of sexual development.uncovering the direct regulatory targets of doublesex (dsx) and fruitless (fru) is crucial for an understanding of how they regulate sexual development, morphogenesis, differentiation and adult functions (including behavior) in drosophila melanogaster. using a modified damid approach, we identified 650 dsx-binding regions in the genome from which we then extracted an optimal palindromic 13 bp dsx-binding sequence. this sequence is functional in vivo, and the base identity at each position is imp ...021652649
interlocked feedforward loops control cell-type-specific rhodopsin expression in the drosophila eye.how complex networks of activators and repressors lead to exquisitely specific cell-type determination during development is poorly understood. in the drosophila eye, expression patterns of rhodopsins define at least eight functionally distinct though related subtypes of photoreceptors. here, we describe a role for the transcription factor gene defective proventriculus (dve) as a critical node in the network regulating rhodopsin expression. dve is a shared component of two opposing, interlocked ...021663797
food availability alters the effects of larval temperature on aedes aegypti growth.variation in temperature and food availability in larval habitats can influence the abundance, body size, and vector competence of the mosquito aedes aegypti. although increased temperature has energetic costs for growing larvae, how food resources influence the developmental response of this mosquito species to thermal conditions is unknown. we explored how rearing temperature and food affect allometric scaling between wing size and epidermal cell size in ae. aegypti. mosquitoes were reared at ...021936315
tagetes erecta linn. and its mosquitocidal potency against culex quinquefasciatus.to investigate mosquitocidal effects of ethanolic extract of flowers of tagetes erecta (t. erecta) and its chloroform and petroleum ether soluble fractions against the larvae of culex quinquefasciatus (cx. quinquefasciatus).023569756
toxicological effects of sphaeranthus indicus linn. (asteraceae) leaf essential oil against human disease vectors, culex quinquefasciatus say and aedes aegypti linn., and impacts on a beneficial mosquito predator.use of environmentally friendly, decomposable natural products for effective vector control has gained considerable momentum in modern society. in this study, essential oil of sphaeranthus indicus (si-eo) was extracted and further phytochemical screening revealed fourteen compounds with prominent peak area percentage of 24.9 and 22.54% in 3,5-di-tert-butyl-4-hydroxybenzaldehyde and benzene,2-(1,1-dimethylethyl)-1,4-dimethoxy, respectively. the si-eo was further evaluated for their larvicidal res ...028455566
larval feeding behavior of three co-occurring species of container mosquitoes.interspecific differences in foraging behavior may help to determine whether the outcome of interspecific competition is coexistence or exclusion. mosquitoes in the genus culex are commonly described as foraging primarily by filtering the water column. this behavior contrasts with that of other container-dwelling genera, such as aedes and ochlerotatus, that are thought to forage primarily by browsing on container and detritus surfaces. we compared the feeding behavior of cx. pipiens, ae. albopic ...015707290
identification of mosquito avian-derived blood meals by polymerase chain reaction-heteroduplex analysis.a polymerase chain reaction (pcr) heteroduplex assay (hda) was developed to identify avian derived mosquito blood meals to the species level. the assay used primers amplifying a fragment of the cytochrome b gene from vertebrate but not invertebrate species. in culex tarsalis fed on quail, pcr products derived from the quail cytochrome b gene were detected seven days post-engorgement. in an analysis of wild-caught mosquitoes, 85% of blood-fed mosquitoes produced detectable pcr products. heterodup ...012201598
risk of transmission of viral haemorrhagic fevers and the insecticide susceptibilitystatus of aedes aegypti (linnaeus) in some sites in accra, ghana.dengue is one of the emerging diseases that can mostly only be controlled by vector control since there is no vaccine for the disease. although, dengue has not been reported in ghana, movement of people from neighbouring countries where the disease has been reported can facilitate transmission of the disease.027752187
arbovirus infections.arbovirus (arthropod-borne virus) infections are increasingly important causes of neurologic disease in the united states through both endemic transmission and travel-associated infections. this article reviews the major arbovirus infections that can cause neurologic disease likely to be encountered in the united states.026633778
chikungunya vaccines in development.chikungunya virus has become a global health threat, spreading to the industrial world of europe and the americas; no treatment or prophylactic vaccine is available. since the late 1960s much effort has been put into the development of a vaccine, and several heterogeneous strategies have already been explored. only two candidates have recently qualified to enter clinical phase ii trials, a chikungunya virus-like particle-based vaccine and a recombinant live attenuated measles virus-vectored vacc ...026554522
climate, environmental and socio-economic change: weighing up the balance in vector-borne disease transmission.arguably one of the most important effects of climate change is the potential impact on human health. while this is likely to take many forms, the implications for future transmission of vector-borne diseases (vbds), given their ongoing contribution to global disease burden, are both extremely important and highly uncertain. in part, this is owing not only to data limitations and methodological challenges when integrating climate-driven vbd models and climate change projections, but also, perhap ...025688012
biological transmission of arboviruses: reexamination of and new insights into components, mechanisms, and unique traits as well as their evolutionary trends.among animal viruses, arboviruses are unique in that they depend on arthropod vectors for transmission. field research and laboratory investigations related to the three components of this unique mode of transmission, virus, vector, and vertebrate host, have produced an enormous amount of valuable information that may be found in numerous publications. however, despite many reviews on specific viruses, diseases, or interests, a systematic approach to organizing the available information on all f ...016223950
factors shaping the adaptive landscape for arboviruses: implications for the emergence of disease.many examples of the emergence or re-emergence of infectious diseases involve the adaptation of zoonotic viruses to new amplification hosts or to humans themselves. these include several instances of simple mutational adaptations, often to hosts closely related to the natural reservoirs. however, based on theoretical grounds, arthropod-borne viruses, or arboviruses, may face several challenges for adaptation to new hosts. here, we review recent findings regarding adaptive evolution of arboviruse ...023374123
protective and pathogenic responses to chikungunya virus infection.chikungunya virus (chikv) is an arbovirus responsible for causing epidemic outbreaks of human disease characterized by painful and often debilitating arthralgia. recently chikv has moved into the caribbean and the americas resulting in massive outbreaks in naïve human populations. given the importance of chikv as an emerging disease, a significant amount of effort has gone into interpreting the virus-host interactions that contribute to protection or virus-induced pathology following chikv infec ...026366337
innate antiviral immunity in drosophila.the study of drosophila, and other genetically tractable insects, has expanded our understanding of innate immunity and more recently antiviral innate mechanisms. the drosophila antiviral program includes inflammatory signaling cascades as well as antiviral rna silencing and autophagy. this review will highlight the recent discoveries in antiviral immunity in insects and will reveal some of the lessons learned.020137906
emerging and re-emerging viruses: a global challenge illustrated by chikungunya virus outbreaks.in recent decades, the issue of emerging and re-emerging infectious diseases, especially those related to viruses, has become an increasingly important area of concern in public health. it is of significance to anticipate future epidemics by accumulating knowledge through appropriate research and by monitoring their emergence using indicators from different sources. the objective is to alert and respond effectively in order to reduce the adverse impact on the general populations. most of the eme ...024175207
the role of environmental variables on aedes albopictus biology and chikungunya epidemiology.aedes albopictus is a vector of dengue and chikungunya viruses in the field, along with around 24 additional arboviruses under laboratory conditions. as an invasive mosquito species, ae. albopictus has been expanding in geographical range over the past 20 years, although the poleward extent of mosquito populations is limited by winter temperatures. nonetheless, population densities depend on environmental conditions and since global climate change projections indicate increasing temperatures and ...023916332
chikungunya virus and prospects for a vaccine.in 2004, chikungunya virus (chikv) re-emerged from east africa to cause devastating epidemics of debilitating and often chronic arthralgia that have affected millions of people in the indian ocean basin and asia. more limited epidemics initiated by travelers subsequently occurred in italy and france, as well as human cases exported to most regions of the world, including the americas where chikv could become endemic. because chikv circulates during epidemics in an urban mosquito-human cycle, con ...023151166
rna interference-mediated antiviral defense in insects.small interfering rna (sirna)-mediated rna interference (rnai) pathways are critical for the detection and inhibition of rna virus replication in insects. recent work has also implicated rnai pathways in the establishment of persistent virus infections and in the control of dna virus replication. accumulating evidence suggests that diverse double-stranded rnas produced by rna and dna viruses can trigger rnai responses yet many viruses have evolved mechanisms to inhibit rnai defenses. therefore, ...026034705
barriers to success: how baculoviruses establish efficient systemic infections.the mechanisms used by baculoviruses to exit the midgut and cause systemic infection of their insect hosts have been debated for decades. after being ingested, baculoviruses reach the midgut, where several host barriers need to be overcome in order to establish successful infection. one of these barriers is the basal lamina, a presumably virus-impermeable extracellular layer secreted by the epithelial cells lining the midgut and trachea. this review discusses new evidence that demonstrates how t ...021300392
rna interference in infectious tropical diseases.introduction of double-stranded rna (dsrna) into some cells or organisms results in degradation of its homologous mrna, a process called rna interference (rnai). the dsrnas are processed into short interfering rnas (sirnas) that subsequently bind to the rna-induced silencing complex (risc), causing degradation of target mrnas. because of this sequence-specific ability to silence target genes, rnai has been extensively used to study gene functions and has the potential to control disease pathogen ...018344671
transgene-mediated suppression of the rna interference pathway in aedes aegypti interferes with gene silencing and enhances sindbis virus and dengue virus type 2 replication.rna interference (rnai) is the major innate antiviral pathway in aedes aegypti that responds to replicating arboviruses such as dengue virus (denv) and sindbis virus (sinv). on the one hand, the mosquito's rnai machinery is capable of completely eliminating denv2 from ae. aegypti. on the other, transient silencing of key genes of the rnai pathway increases replication of sinv and denv2, allowing the viruses to temporally overcome dose-dependent midgut infection and midgut escape barriers (meb) m ...023331493
a genome-wide rnai screen reveals that mrna decapping restricts bunyaviral replication by limiting the pools of dcp2-accessible targets for cap-snatching.bunyaviruses are an emerging group of medically important viruses, many of which are transmitted from insects to mammals. to identify host factors that impact infection, we performed a genome-wide rnai screen in drosophila and identified 131 genes that impacted infection of the mosquito-transmitted bunyavirus rift valley fever virus (rvfv). dcp2, the catalytic component of the mrna decapping machinery, and two decapping activators, ddx6 and lsm7, were antiviral against disparate bunyaviruses in ...023824541
mosquito immune responses to arbovirus infections.the principal mosquito innate immune response to virus infections, rna interference (rnai), differs substantially from the immune response to bacterial and fungal infections. the exo-sirna pathway constitutes the major anti-arboviral rnai response and its essential genetic components have been identified. recent research has also implicated the piwi-interacting rna pathway in mosquito anti-arboviral immunity, but piwi gene-family components involved are not well-defined. arboviruses must evade o ...025401084
host inflammatory response to mosquito bites enhances the severity of arbovirus infection.aedes aegypti mosquitoes are responsible for transmitting many medically important viruses such as those that cause zika and dengue. the inoculation of viruses into mosquito bite sites is an important and common stage of all mosquito-borne virus infections. we show, using semliki forest virus and bunyamwera virus, that these viruses use this inflammatory niche to aid their replication and dissemination in vivo. mosquito bites were characterized by an edema that retained virus at the inoculation ...027332734
specificity of resistance to dengue virus isolates is associated with genotypes of the mosquito antiviral gene dicer-2.in contrast to the prevailing view that invertebrate immunity relies on broad-spectrum recognition and effector mechanisms, intrinsic genetic compatibility between invertebrate hosts and their pathogens is often highly specific in nature. solving this puzzle requires a better understanding of the molecular basis underlying observed patterns of invertebrate host-pathogen genetic specificity, broadly referred to as genotype-by-genotype interactions. here, we identify an invertebrate immune gene in ...023193131
tackling the most difficult diseases. genetics and genomics open new strategies to fight vector-borne diseases. 011600446
wing shape as an indicator of larval rearing conditions for aedes albopictus and aedes aegypti (diptera: culicidae).estimating a mosquito's vector competence, or likelihood of transmitting disease, if it takes an infectious bloodmeal, is an important aspect of predicting when and where outbreaks of infectious diseases will occur. vector competence can be affected by rearing temperature and inter- and intraspecific competition experienced by the individual mosquito during its larval development. this research investigates whether a new morphological indicator of larval rearing conditions, wing shape, can be us ...022897054
mechanisms of arthropod transmission of plant and animal viruses.a majority of the plant-infecting viruses and many of the animal-infecting viruses are dependent upon arthropod vectors for transmission between hosts and/or as alternative hosts. the viruses have evolved specific associations with their vectors, and we are beginning to understand the underlying mechanisms that regulate the virus transmission process. a majority of plant viruses are carried on the cuticle lining of a vector's mouthparts or foregut. this initially appeared to be simple mechanical ...010066833
larval food quantity affects the capacity of adult mosquitoes to transmit human malaria.adult traits of holometabolous insects are shaped by conditions experienced during larval development, which might impact interactions between adult insect hosts and parasites. however, the ecology of larval insects that vector disease remains poorly understood. here, we used anopheles stephensi mosquitoes and the human malaria parasite plasmodium falciparum, to investigate whether larval conditions affect the capacity of adult mosquitoes to transmit malaria. we reared larvae in two groups; one ...027412284
antiviral defense mechanisms in honey bees.honey bees are significant pollinators of agricultural crops and other important plant species. high annual losses of honey bee colonies in north america and in some parts of europe have profound ecological and economic implications. colony losses have been attributed to multiple factors including rna viruses, thus understanding bee antiviral defense mechanisms may result in the development of strategies that mitigate colony losses. honey bee antiviral defense mechanisms include rna-interference ...026273564
microbiota-dependent priming of antiviral intestinal immunity in drosophila.enteric pathogens must overcome intestinal defenses to establish infection. in drosophila, the erk signaling pathway inhibits enteric virus infection. the intestinal microflora also impacts immunity but its role in enteric viral infection is unknown. here we show that two signals are required to activate antiviral erk signaling in the intestinal epithelium. one signal depends on recognition of peptidoglycan from the microbiota, particularly from the commensal acetobacter pomorum, which primes th ...026567510
transcriptional pausing controls a rapid antiviral innate immune response in drosophila.innate immune responses are characterized by precise gene expression whereby gene subsets are temporally induced to limit infection, although the mechanisms involved are incompletely understood. we show that antiviral immunity in drosophila requires the transcriptional pausing pathway, including negative elongation factor (nelf) that pauses rna polymerase ii (pol ii) and positive elongation factor b (p-tefb), which releases paused pol ii to produce full-length transcripts. we identify a set of g ...023084920
assessing the epidemic potential of rna and dna viruses.many new and emerging rna and dna viruses are zoonotic or have zoonotic origins in an animal reservoir that is usually mammalian and sometimes avian. not all zoonotic viruses are transmissible (directly or by an arthropod vector) between human hosts. virus genome sequence data provide the best evidence of transmission. of human transmissible virus, 37 species have so far been restricted to self-limiting outbreaks. these viruses are priorities for surveillance because relatively minor changes in ...027869592
dengue: challenges for policy makers and vaccine developers.because of the increasing incidence, geographic expansion and economic burden of dengue transmission, dengue poses major challenges to policy makers. a vaccine against dengue is urgently needed, but vaccine development has been hampered by the lack of an appropriate animal model, poor understanding of correlates of successful human immunity, the fear of immune enhancement, and viral interference in tetravalent combinations. the most suitable target epitopes for vaccines, as well as the role of n ...024781826
novel genetic and molecular tools for the investigation and control of dengue virus transmission by mosquitoes.aedes aegypti is the principal vector of dengue virus (denv) throughout the tropical world. this anthropophilic mosquito species needs to be persistently infected with denv before it can transmit the virus through its saliva to a new vertebrate host. in the mosquito, denv is confronted with several innate immune pathways, among which rna interference is considered the most important. the ae. aegypti genome project opened the doors for advanced molecular studies on pathogen-vector interactions in ...024693489
mayaro virus infection, amazon basin region, peru, 2010-2013.during 2010-2013, we recruited 16 persons with confirmed mayaro virus infection in the peruvian amazon to prospectively follow clinical symptoms and serologic response over a 12-month period. mayaro virus infection caused long-term arthralgia in more than half, similar to reports of other arthritogenic alphaviruses.024210165
the status of infectious disease in the amazon region.the amazon river basin region is a vast territory with an area >7 million km2, encompassing parts of 9 south american countries: bolivia, brazil, colombia, ecuador, french guiana, guyana, peru, suriname, and venezuela. the amazon river, the longest river in the world, traverses the region from west to east, fed by multiple tributaries. the region also contains the largest tropical rainforest in the world, situated on a massive plain whose altitude is near sea level. with a climate characterized ...019331757
molecular detection and typing of dengue viruses from archived tissues of fatal cases by rt-pcr and sequencing: diagnostic and epidemiologic implications.diagnosis of dengue virus (denv) infection in fatal cases is challenging because of the frequent unavailability of blood or fresh tissues. for formalin-fixed, paraffin-embedded (ffpe) tissues immunohistochemistry (ihc) can be used; however, it may not be as sensitive and serotyping is not possible. the application of reverse transcription-polymerase chain reaction (rt-pcr) for the detection of denv in ffpe tissues has been very limited. we evaluated ffpe autopsy tissues of 122 patients with susp ...022302871
deadly intracranial bleed in patients with dengue fever: a series of nine patients and review of literature.dengue fever is a global pandemic threat with increasing incidence. to date, there are no cures and the effectiveness of dengue vaccines is still uncertain. world heath organization introduced expanded dengue syndrome to include unusual presentations of dengue fever including severe neurologic complications. one of the deadly complications is intracranial hemorrhage (ich).027365962
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