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ribosomal dna difference between species a and d of the anopheles dirus complex of mosquitoes from china.species a and d of the anopheles dirus complex were found in china. ribosomal dna second internal transcribed spacers (its2) of both species a and d were sequenced and found to be 716 and 710 base-pairs in length, respectively, with 69% gc content. no evidence of intraspecific variation was detected in the its2 sequence of species a, whereas the sequence of species d showed variation at one position in the its2. a large number of simple repeat motifs were dispersed throughout the its2 sequences. ...19979226641
studies on infections with two strains of plasmodium inui from taiwan in rhesus monkeys and different anopheline mosquitoes.rhesus monkeys infected with the taiwan strains of plasmodium inui could be appropriate models for understanding host-parasite relationships during long-term chronic infection. two strains of p. inui originally from taiwan were studied in rhesus monkeys and different anopheline mosquitoes. maximum parasite counts for 13 intact animals infected with the taiwan i strain ranged from 22,215 to 760,000/microl (median maximum parasite count = 242,800/microl). following splenectomy, the maximum parasit ...19989645855
cloning, expression and characterization of an insect class i glutathione s-transferase from anopheles dirus species b.insect class i glutathione s-transferases (gsts) were expressed from cdna obtained from larvae of the thai malaria vector. anopheles dirus in a pcr race (rapid amplification of cdna ends) reaction using a primer to the conserved n-terminal region of an. gambiae class i gsts and a synthetic oligo d(t)-adaptor primer. seven different plasmids, resulting from sub-cloning of an original single 0.7 kb pcr band, were picked at random and sequenced. four of these were clearly gsts on the basis of putat ...19989692235
sequence heterogeneity in copia-like retrotransposons in anopheles (diptera: culicidae) in thailand.degenerate primers and the polymerase chain reaction (pcr) detected a conserved region of copia-like reverse transcriptase from anopheles mosquitoes in thailand. a total of 43 subclone pcr fragments of the size expected for reverse transcriptase of copia-like elements was isolated from anopheles dirus (peyton & harrison) subspecies a, anopheles maculatus (theobald) subspecies e, anopheles nivipes (theobald), and anopheles subpictus grassi. sequence analysis of subclones confirmed the identity of ...19989775607
susceptibility of the malaria vectors to insecticides in bangladesh.insecticide susceptibility tests with diagnostic dosages of 4% ddt and 5% malathion concentrations conducted at field sites on the two important principal malaria vectors namely, anopheles dirus and an. philippinensis have been reported. they are found to be susceptible to ddt and malathion. the implication of the use of insecticides in controlling malaria is also discussed.19989776867
a review of leucosphyrus group with particular reference to the anopheles dirus complex (diptera: culicidae) in india.the classification of the leucosphyrus group remained confused for long. the taxonomic events until it was resolved are traced in this review. the significance the description of anopheles dirus as a new species and the subsequent characterization of its siblings are outlined. the current classification of the leucosphyrus group is presented and the various methods available for identifying the members of the dirus species complex are highlighted. based on the limited information available about ...19989842168
attempts to transmit the n-3 strain of plasmodium fieldi to aotus monkeys.aotus lemurinus griseimembra monkeys inoculated with parasitized erythrocytes of the n-3 strain of plasmodiumfieldi had transient low-density parasitemia. exoerythrocytic stages of this strain of parasite were demonstrated in sections of liver from aotus vociferans monkeys taken 8 days after the intravenous inoculation of sporozoites dissected from the salivary glands of anopheles dirus mosquitoes; no blood-stage infections were observed.19989488369
insecticide susceptibility of anopheles dirus in assam. 199810810572
larval ecology and mosquito fauna of upper brahmaputra valley, northeast india.ninety-one mosquito species in 15 genera were collected from 22 habitat types of upper brahmaputra valley in assam and bordering areas of arunachal pradesh. nineteen species have been recorded for the first time in assam including seven first records from the northeast region and three first country records. jaccard's coefficient was used to quantify the similarity between 13 different geographical localities surveyed on the basis of their mosquito fauna. group average sorting (upgma) cluster an ...199810497839
a diagnostic polymerase chain reaction assay for species a and d of the anopheles dirus (diptera: culicidae) species complex based on ribosomal dna second internal transcribed spacer sequence.a polymerase chain reaction assay based on differences in the internal transcribed spacer regions of ribosomal dna was developed for distinguishing 2 members of the anopheles dirus sibling species complex. this assay distinguished an. dirus species a from species d by producing diagnostic bands, 374 base pairs (bp) in length for species a and 663 bp in length for species d. both laboratory colonies and field collections from hainan and yunnan provinces of china were identified with 100% accuracy ...199810084131
[current status of studies on biosystematic and malaria transmission of anopheles dirus in china]. 199812078249
[differentiation of cryptic species a and d of anopheles dirus complex by polymerase chain reaction].to distinguish cryptic species a and d of anopheles dirus complex using polymerase chain reaction (pcr).199812078235
[observation on efficacy of artemether compound against vivax malaria].to observe the efficacy of artemether compound against vivax malaria.199912563840
selection of anopheles dirus for refractoriness and susceptibility to plasmodium yoelii nigeriensis.two lines of the oriental malaria vector mosquito anopheles dirus species a (diptera: culicidae), one fully refractory and one fully susceptible to plasmodium yoelii nigeriensis (an african rodent malaria parasite), were established after 17 generations of mass selection, followed by single female selection for one or two generations. prior to selection, the stock colony of an. dirus was 17% refractory. both lines of an. dirus produced abundant ookinetes that started to invade the midgut within ...199910608223
well-breeding anopheles dirus and their role in malaria transmission in myanmar.mosquitos were collected with human and animal baits from march 1996 to january 1998 in four villages located along the yadana gas pipe line in yepyu township, dawae district, tanintharyi division, southern myanmar. a total of 23 anopheline species were collected. anopheles dirus were abundant in pre-monsoon (may/june) an post-monsoon (october) months. all an. dirus caught both humans and cattle were assayed with specific, sporozoite enzyme-linked immunosorbent assays (elisas). a total of 5/250 ...199910774650
[malaria situation in the people's republic of china in 1998].notwithstanding there was a flood over the five provinces located at the middle and lower reaches of the changjiang river, i.e. hunan, hubei, jiangxi, anhui and jiangsu, in the summer and autumn of 1998, the prevalence of malaria in these areas was basically stable or slightly decreased as a result of timely implementing active and effective preventive measures. according to the case reporting system, the number of malaria cases of the whole nation totaled 31,319 in 1998, with a mean incidence o ...199912563754
efficient expression of mosquito-larvicidal proteins in a gram-negative bacterium capable of recolonization in the guts of anopheles dirus larva.the gram-negative bacterium, an11/2 g1, isolated from the guts of anopheles dirus mosquito larvae, was identified as enterobacter amnigenus. the e. amnigenus was able to recolonize in the gut of an. dirus larva but not in those of aedes aegypti and culex quinquefasciatus larvae. it was able to float in water for a longer period than bacillus thuringiensis subsp. israelensis and bacillus sphaericus. these are desirable characteristics for a delivery vehicle of mosquito-larvicidal toxins for the c ...199910077823
identification of five species of the anopheles dirus complex from thailand, using allele-specific polymerase chain reaction.the anopheles dirus complex of mosquitoes contains some of the most important vectors of malaria in southeast asia. to distinguish five species of the complex that occur in thailand, a method using the polymerase chain reaction (pcr) was developed. the method utilizes allele-specific amplification to detect fixed differences between the species in the dna sequence of the ribosomal dna internal transcribed spacer 2. primers were designed to amplify fragments of diagnostic length from the dna of t ...199910194746
studies on infections with the berok strain of plasmodium cynomolgi in monkeys and mosquitoes.infections with the berok strain of plasmodium cynomolgi were induced in macaca mulatta, macaca fascicularis, macaca nemestrina, aotus lemurinus griseimembra, aotus azarae boliviensis, and saimiri boliviensis monkeys. transmission was obtained with sporozoites developing in anopheles peditaeniatus, anopheles maculatus, anopheles quadrimaculatus, anopheles culicifacies, and anopheles dirus mosquitoes. this strain of p. cynomolgi offers significant potential for a number of experimental studies. t ...199910219307
adaptation of the amru-1 strain of plasmodium vivax to aotus and saimiri monkeys and to four species of anopheline mosquitoes.a chloroquine-resistant strain of plasmodium vivax (amru-1) from papua new guinea has been adapted to grow in 4 species of aotus monkeys (aotus lemurinus griseimembra, aotus vaciferans, aotus nancymai, and aotus azarae boliviensis), hybrid aotus monkeys, and saimiri boliviensis monkeys. whereas it was possible to infect saimiri monkeys with this parasite by inoculation of parasitized erythrocytes, only 42% of saimiri monkeys became infected, compared to 92% of aotus monkeys attempted. comparativ ...199910461947
population structure and population history of anopheles dirus mosquitoes in southeast asia.separating the confounding effects of long-term population history from gene flow can be difficult. here, we address the question of what inferences about gene flow can be made from mitochondrial sequence data in three closely related species of mosquitoes, anopheles dirus species a, c, and d, from southeast asia. a total of 84 sequences of 923 bp of the mitochondrial cytochrome oxidase i gene were obtained from 14 populations in thailand, myanmar, and bangladesh. the genealogy of sequences obta ...200010833203
the isolation and characterization of microsatellites from anopheles dirus mosquitoes. 200011050564
mosquito fauna and malaria vectors in jairampur, district changlang, arunachal pradesh.in an entomological study, covering three biotopes like village, panikheti (wet rice cultivated land) and urban agglomeration, a total of 35 species of mosquitoes in eight genera were recorded in jairampur area of arunachal pradesh. two mosquito species--orthopodomyia anopheloides and tripteroides indicus were recorded for the first time in arunachal pradesh. anopheles dirus and an. minimus, the two well-known malaria vectors were encountered in the study along with several potential vector spec ...200011820089
status of malaria in thailand.despite decades of control success and a competent network of country-wide health infrastructure, malaria remains an important health threat in rural thailand. all 4 known human malaria parasites have been reported present, with plasmodium falciparum and plasmodium vivax predominant. the expansion and intensity of multi-drug resistant plasmodium falciparum is the most serious development to occur the last several decades. members of 3 anopheline species complexes, anopheles dirus, anopheles mini ...200011127318
a preliminary field study on repellency of neem oil against anopheles dirus (diptera:culicidae) in assam. 200011198400
anthropophily of anophelines in duars of west bengal and other regions of india.attempts have been made to identify the source of blood meals of twenty three anopheline species from various areas of high malaria endemicity in india. anopheles minimus, anopheles fluviatilis and anopheles dirus showed a high propensity for human blood in north-eastern parts of the country while anopheles sundicus was found to be anthropophilic in andaman & nicobar islands. anopheles culicifacies, anopheles maculatus and anopheles philippinensis were found primarily zoophilic in north-eastern ...200011198404
isoenzymes of glutathione s-transferase from the mosquito anopheles dirus species b: the purification, partial characterization and interaction with various insecticides.previously we have purified and characterized a major glutathione s-transferase (gst) activity, gst-4a, from the thai mosquito anopheles dirus b, a model mosquito for study of anopheline malaria vectors [prapanthadara, l. koottathep, s., promtet, n., hemingway, j. and ketterman, a.j. (1996) insect biochem. mol. biol. 26:3, 277-285]. in this report we have purified an isoenzyme, gst-4c, which has the greatest ddt-dehydrochlorinase activity. three additional isoenzymes, gst-4b, gst-5 and gst-6, we ...200010745163
[molecular identification of sibling anopheles species: example of the anopheles minimus and anopheles dirus complexes, major malarial vectors in southeast asia].effective control of malaria vectors requires precise identification of species. this is especially important within complexes of species that cannot be distinguished based on morphological features. two methods based on polymerase chain reaction (pcr) analysis have been developed to identify 2 species in the anopheles minimus complex and 5 species of the minimums group as well as 4 species of the anopheles dirus complex. association of oligonucleotide couples in the form of multiplex pcr has al ...200111980390
structural biology and its applications to the health sciences.part of the decipherment of genomic information lies in understanding the structure and function of the protein products of these genes. protein structure is of further importance because of the molecular basis of many diseases. structural biology is the field of research focusing on the experimental determination of the structure of biological molecules. we review the field of structural biology and its application to medical research and drug discovery, and describe the structural results rece ...200111471188
crystallization of two glutathione s-transferases from an unusual gene family.two glutathione s-transferase isozymes from the mosquito anopheles dirus (adgst1-3 and adgst1-4) from an alternately spliced gene family have been expressed, purified and crystallized. the isozymes share an n-terminal domain derived from a single exon and c-terminal domains from unique exons. despite the high level of sequence identity (64% overall), the two isozymes crystallize in different space groups, the 1-3 isozyme in p3(1)21 or p3(2)21 (unit-cell parameters a = 49.9, c = 271.8 a at 100 k) ...200111375512
genetic population structure and introgression in anopheles dirus mosquitoes in south-east asia.genetic structure and species relationships were studied in three closely related mosquito species, anopheles dirus a, c and d in thailand using 11 microsatellite loci and compared with previous mitochondrial dna (mtdna) data on the same populations. all three species were well differentiated from each other at the microsatellite loci. given the almost complete absence of mtdna differentiation between an. dirus a and d, this endorses the previous suggestion of mtdna introgression between these s ...200111298969
single amino acid changes outside the active site significantly affect activity of glutathione s-transferases.glutathione s-transferases (gsts: e.c. 2.5.1.18) are a multigene family of multifunctional dimeric proteins that play a central role in detoxication. four allelic forms of the mosquito anopheles dirus gst, adgst1-1, were cloned, expressed and characterized. the one or two amino acid changes in each allelic form was shown to confer different kinetic properties. based on an available crystal structure, several of the residue changes were not in the putative substrate-binding pocket. modeling showe ...200111102836
heterologous expression and characterization of alternatively spliced glutathione s-transferases from a single anopheles gene.three cdna sequences of glutathione s-transferase (gst), adgst1-2, adgst1-3 and adgst1-4, which are alternatively spliced products of the adgst1as1 gene, were obtained from fourth instar larvae of anopheles dirus mosquito by reverse transcriptase pcr reactions. the nucleotide sequences of these three cdnas share >67% identity and the translated amino acid sequences share 61-64% identity. a comparison of the an. dirus to the an. gambiae enzymes shows that adgst1-2 versus aggst1-4, adgst1-3 versus ...200111439246
plasmodium coatneyi: observations on periodicity, mosquito infection, and transmission to macaca mulatta monkeys.plasmodium coatneyi has adapted well to experimental studies with macaca mulatta monkeys and anopheles dirus mosquitoes. studies were made to determine 1) the course of asexual parasitemia, 2) periods when infective gametocytes were produced, 3) the laboratory-reared mosquitoes susceptible to infection, 4) the mosquito most capable of transmitting the infection to monkeys via bite, 5) the pattern of recrudescence, and 6) the prepatent periods following the bites of infected an. dirus mosquitoes. ...200111442203
repellency of volatile oils from plants against three mosquito vectors.volatile oils extracted by steam distillation from four plant species (turmeric (curcuma longa), kaffir lime (citrus hystrix), citronella grass (cymbopogon winterianus) and hairy basil (ocimum americanum)), were evaluated in mosquito cages and in a large room for their repellency effects against three mosquito vectors, aedes aegypti, anopheles dirus and culex quinquefasciatus. the oils from turmeric, citronella grass and hairy basil, especially with the addition of 5% vanillin, repelled the thre ...200111469188
multistage multiantigen heterologous prime boost vaccine for plasmodium knowlesi malaria provides partial protection in rhesus macaques.a nonhuman primate model for malaria vaccine development allowing reliable, stringent sporozoite challenge and evaluation of both cellular and antibody responses is needed. we therefore constructed a multicomponent, multistage dna vaccine for the simian malaria species plasmodium knowlesi including two preerythrocytic-stage antigens, the circumsporozoite protein (pkcsp) and sporozoite surface protein 2 (pkssp2), and two blood stage antigens, apical merozoite antigen 1 (pkama1) and merozoite surf ...200111500430
development of a method for the in vitro production of plasmodium vivax ookinetes.we developed a method for the in vitro production of mature plasmodium vivax ookinetes. gametocytemic blood was collected from 98 p. vivax-infected patients reporting to malaria clinics in maesod and maekasa districts, tak province, thailand. briefly, gametogenesis was induced using xanthurenic acid and parasites were separated by density gradient centrifugation and then cultured in rpmi-1640, ph 7.8-8.2. at the same time that blood was collected, 200 anopheles dirus mosquitoes were allowed to f ...200111534665
prevention of sporogony of plasmodium vivax in anopheles dirus mosquitoes by transmission-blocking antimalarials.the sporontocidal activity of four dihydroacridine-diones (wr-233602, wr-243251, wr-250547, and wr-250548) and three fluoroquinolones (wr-279135, wr-279298, and wr-279288) was determined against naturally circulating isolates of plasmodium vivax. laboratory-reared anopheles dirus mosquitoes were infected with p. vivax by feeding them on gametocytemic volunteers reporting to local malaria clinics in kanchanaburi and tak provinces, thailand. four days after the infectious feed, mosquitoes were re- ...200111561707
the crystal structures of glutathione s-transferases isozymes 1-3 and 1-4 from anopheles dirus species b.glutathione s-transferases (gsts) are dimeric proteins that play an important role in cellular detoxification. four gsts from the mosquito anopheles dirus species b (ad), an important malaria vector in south east asia, are produced by alternate splicing of a single transcription product and were previously shown to have detoxifying activity towards pesticides such as ddt. we have determined the crystal structures for two of these alternatively spliced proteins, adgst1-3 (complexed with glutathio ...200111604524
recombinant enterobacter amnigenus highly toxic to anopheles dirus mosquito larvae.the mosquito-larvicidal binary toxin of bacillus sphaericus 2297 was expressed in enterobacter amnigenus, a gram-negative bacterium isolated from anopheles dirus larvae gut. the toxin was placed under the regulation of various promoters in order to improve the expression level of the toxin. amongst the recombinants obtained, e. amnigenus harboring pbs373, a plasmid which contains the toxin genes under the control of the native b. sphaericus promoter, expressed a significant amount of protein, co ...200111685515
targeting plasmodium ligands on mosquito salivary glands and midgut with a phage display peptide library.despite vast efforts and expenditures in the past few decades, malaria continues to kill millions of persons every year, and new approaches for disease control are urgently needed. to complete its life cycle in the mosquito, plasmodium, the causative agent of malaria, has to traverse the epithelia of the midgut and salivary glands. although strong circumstantial evidence indicates that parasite interactions with the two organs are specific, hardly any information is available about the interacti ...200111687659
confirmation of anopheles varuna in vietnam, previously misidentified and mistargeted as the malaria vector anopheles minimus.malaria control programs in southeast asia are faced with several questions concerning vector behavior and species identification, which need to be answered to consolidate and further improve the results of control practices. the vector system in southeast asia is complex because of the number of species potentially involved in malaria transmission. additionally, the follow-up and evaluation of preventive control measures are hampered by the misidentification of vectors due to overlapping morpho ...200111791965
a rapid polymerase chain reaction based method for identification of the anopheles dirus sibling species.a simple polymerase chain reaction (pcr) based method was developed to differentiate the anopheles dirus, species a, b, c and d in thailand using specific primers designed from species specific sequences. the pcr protocol was optimized to obtain products of 120 bp, 75 bp, 60 bp and 172 bp for species a, b, c and d, respectively. this method used a cocktail of four primer sets to identify these an. dirus sibling species. the method is very sensitive as only a small portion of mosquito was require ...200111944726
laboratory and field evaluations of the insect repellent 3535 (ethyl butylacetylaminopropionate) and deet against mosquito vectors in thailand.the insect repellents 3535 (ethyl butylacetylaminopropionate or ir3535) and deet (n,n-diethyl-3-methylbenzamide) were prepared as 20% solutions in absolute ethanol and evaluated for repellency against many mosquito species in thailand under laboratory and field conditions using human subjects. in the laboratory, 0.1 ml was applied per 30-cm2 of exposed area on a volunteer's forearm (0.66-0.67 mg active ingredient [ai]/ cm2), whereas in the field, volunteers' legs (from knee to ankle, with a surf ...200114529087
estimation of vectorial capacity of anopheles dirus (diptera: culicidae) in a forest-fringed village of assam (india).to estimate the vectorial capacity of anopheles dirus, the main vector of forest malaria in the northeastern region of india, in order to gain an understanding of entomological factors related to malaria transmission in forest-fringe areas of assam, india, an isolated village in the tropical rain forest-fringed area in the district of dibrugarh, assam, under the influence of an. dirus alone was studied. data on various entomological variables required for computation of the vectorial capacity we ...200112653151
isolation of bacterial strains colonizable in mosquito larval guts as novel host cells for mosquito control.we screened for microorganisms that can be utilized as new host cells for mosquito larvicides. as long persistence in the environment is required of host cells, we examined the bacterial populations in the guts of mosquito larvae collected from natural breeding habitats. larvae of aedes aegypti and culex quinquefasciatus were examined, and bacillus species, particularly bacillus cereus, were found to be the dominant bacterial species in their guts. to investigate the relationship between these b ...200116233108
genomic organization and putative promoters of highly conserved glutathione s-transferases originating by alternative splicing in anopheles dirus.the genomic dna of a gst class i alternative splicing gene has been characterized from anopheles dirus, a thai malaria vector. this gene organization is highly conserved in an. dirus and anopheles gambiae (aggst1alpha), with >80% nucleotide identity in the coding region. their gene organization contains six exons for four mature gst transcripts, which share exon 1 and exon 2 but vary between four different exon 3 sequences (exon 3a-3d). the deduced amino acid sequence of the gst transcripts from ...200111102837
entomological surveys of malaria in khammouane province, lao pdr, in 1999 and 2000.anopheline mosquitos and their relation to malaria transmission were studied 3 times: in july and august, 1999; in december, 1999; and in august and september, 2000. the studies took place in the malaria endemic villages of khammouane province, southeast of lao pdr. a total of 28 species were collected using human and animal bait. human bait attracted predominantly anopheles dirus and an. minimus, which were identified as vectors by the detection of sporozoites by dissection, pcr, and enzyme-lin ...200212693588
trypsin and aminopeptidase activities in blood-fed females anopheles dirus (diptera: culicidae) of differing susceptibility to plasmodium yoelii nigeriensis.midgut proteolytic enzymes contribute to the success or failure of plasmodium infection of the mosquito. the present study investigated trypsin and aminopeptidase activities in the midgut of two strains of anopheles dirus selected for susceptibility and refractoriness to plasmodium yoelii nigeriensis. at intervals of 6 hours following a bloodmeal, the midguts of fully engorged female mosquitos were dissected, homogenized, and assayed for enzyme activity. no differences trypsin activity (nmole/mi ...200212757211
indoor thermal fogging against vector mosquitoes with two bacillus thuringiensis israelensis formulations, vectobac abg 6511 water-dispersible granules and vectobac 12as liquid.bioefficacy of thermal fogging application of 2 bacillus thuringiensis israelensis formulations, vectobac abg 6511 water-dispersible granules (3,000 international toxic unit [itu]/mg) and vectobac 12as liquid (1,200 itu/mg), was assessed for larvicidal activities against aedes aegypti, aedes albopictus, anopheles dirus, and culex quinquefasciatus. portable agrofog af35 sprayers were used to apply the 2 formulations indoors in residential premises on penang island, malaysia. vectobac abg 6511 sho ...200211998931
infection of aotus and saimiri monkeys with plasmodium gonderi.attempts were made to infect 4 species of new world monkeys (saimiri boliviensis, aotus nancymai, a. vociferans, a. azarae boliviensis) with plasmodium gonderi, a malaria parasite of african monkeys. sporozoites were obtained from anopheles dirus or a. stephensi mosquitoes that fed on an infected rhesus monkey (macaca mulatta). inoculation of sporozoites was by injection of dissected sporozoites by either the intravenous or intrahepatic routes, or by mosquito bite. liver biopsies done 7 or 8 day ...200212054031
protection of rhesus macaques against lethal plasmodium knowlesi malaria by a heterologous dna priming and poxvirus boosting immunization regimen.we tested a cytokine-enhanced, multiantigen, dna priming and poxvirus boosting vaccine regimen for prevention of malaria in the plasmodium knowlesi-rhesus macaque model system. animals were primed with a mixture of dna plasmids encoding two preerythrocytic-stage proteins and two erythrocytic-stage proteins from p. knowlesi and combinations of the cytokines granulocyte-macrophage colony-stimulating factor, interleukin-4, and tumor necrosis factor alpha and were boosted with a mixture of four reco ...200212117942
studies on the bionomics of anopheles dirus (culicidae: diptera) in mudon, mon state, myanmar.this study examined some environmental factors influencing the larval habitats of anopheles dirus (breeding in wells) in mudon, myanmar, from may 1998 to march 2000. the larval/pupal density was found to be directly proportional to rainfall and indirectly proportional to the well water level. shade, vegetation and debris on the surface of well water were important factors influencing the abundance of the aquatic stages of an. dirus. salinity had an inverse correlation with the larval and pupal d ...200212125872
potential of the panama strain of plasmodium vivax for the testing of malarial vaccines in aotus nancymai monkeys.aotus monkeys were infected with a strain of plasmodium vivax from panama to determine its potential for the testing of malarial vaccines. after sporozoite inoculation, 3 splenectomized aotus nancymai that had been infected previously with plasmodium falciparum and p. vivax had prepatent periods of 13, 15, and 15 days with maximum parasite counts of 12,726/microl, 5,310/microl, and 9,180/microl. three other a. nancymai previously infected with p. falciparum only had prepatent periods of 17, 15, ...200212479543
physico-chemical characteristics of breeding habitats of anopheles dirus (diptera:culicidae) in assam, india.larval ecology of anopheles dirus, the main vector of forest malaria in north-eastern region of india, was studied in relation to physico-chemical characteristics of its breeding habitats in a rain forest area of assam, india. shady stream side pools, positive for the breeding of an. dirus, had significantly higher amounts of total hardness (p < 0.024) in comparison to negative pools of similar type. when compared with an. dirus negative breeding habitats, in hot-wet as well as in cool-dry seaso ...200212617325
scar markers and multiplex pcr-based identification of isomorphic species in the anopheles dirus complex in southeast asia.the anopheles dirus peyton & harrison complex of mosquitoes (diptera: culicidae) comprises seven known species, including important malaria vectors in southeast asia. specific identification of each species of the complex, which cannot be distinguished using morphological characters, is crucial for understanding vector ecology and implementing effective control measures. derived from individual random amplified polymorphic dna (rapd) markers, sequence characterized amplified regions (scar) were ...200211963981
expression and characterization of a novel class of glutathione s-transferase from anopheles dirus.a new anopheles dirus glutathione s-transferase (gst) has been obtained and named adgst4-1. both genomic dna and cdna for heterologous expression were acquired. the genomic sequence was 3188bp and consisted of the gst gene as well as flanking sequence. the flanking sequence was analyzed for possible regulatory elements that would control gene expression. in drosophila several of these elements have been shown to be involved in development and cell differentiation. the deduced amino acid sequence ...200211886777
[a method for prolonging the preservation of the eggs of anopheles dirus]. 200315108516
multiple roles of glutathione binding-site residues of glutathione s-transferase.this study was designed to characterize residues in the glutathione binding site of adgstd4-4 from the mosquito malaria vector anopheles dirus. the data revealed that leu33, his38 and his50 each play a role in enzyme catalysis and glutathione binding. the mutants of these three residues also displayed differences in hydrophobic substrate specificity, suggesting that changes in the active site conformation occurred. differences in conformations was also suggested by protein stability changes. the ...200314561132
a non-active site residue, cysteine 69, of glutathione s-transferase adgstd3-3 has a role in stability and catalytic function.the cys69 residue of an anopheles dirus glutathione s-transferase isoform (adgstd3-3), was characterized to elucidate its contribution in both catalysis and structural support. nine mutants were generated at this position by replacing the residue with polar, non-polar and charged residues. the polar residues changed the vm of the enzymes. with non-polar residues, the enzymes were unable to fold and were expressed in the insoluble inclusion form. with charged residues, the soluble enzyme yields w ...200314529491
epidemiological models for the spread of anti-malarial resistance.the spread of drug resistance is making malaria control increasingly difficult. mathematical models for the transmission dynamics of drug sensitive and resistant strains can be a useful tool to help to understand the factors that influence the spread of drug resistance, and they can therefore help in the design of rational strategies for the control of drug resistance.200312643812
transmission of malaria and its control in the northeastern region of india.let alone the eradication, malaria control itself has amounted to be a challenge, and is detrimental to the all round development of the northeastern region of india. focal outbreaks are frequent taking heavy tool on human lives. plasmodium falciparum is the predominant parasite species and is solely responsible for increased morbidity and mortality. the region contributes bulk of p. falciparum cases for the rest of india, and its proportions are increasing. efficient vectors like anopheles mini ...200315260392
serum antibodies induced by intranasal immunization of mice with plasmodium vivax pvs25 co-administered with cholera toxin completely block parasite transmission to mosquitoes.transmission-blocking vaccines (tbvs) targeting ookinete surface proteins expressed on sexual-stage malaria parasites are considered one promising strategy for malaria control. to evaluate the prospect of developing non-invasive and easy-to-administer mucosal malaria transmission-blocking vaccines, mice were immunized intranasally with a plasmodium vivax ookinete surface protein, pvs25 with a mucosal adjuvant cholera toxin (ct). immunization induced significant serum igg with high igg1/igg2a rat ...200312804841
the development of exoerythrocytic stages of plasmodium inui shortti in new world monkeys.attempts are being made to adapt old world monkey malarial parasites to new world monkeys for vaccine and molecular studies. several of these (plasmodium cynomolgi berok, plasmodium fragile, and plasmodium knowlesi) grow readily but have failed to produce infective gametocytes. plasmodium gonderi and plasmodium fieldi develop in the liver after sporozoite inoculation but have failed to establish infection in the erythrocyte. anopheles dirus mosquitoes infected with plasmodium inui shortti by fee ...200312880277
[study on the relationship between intracellular free calcium and melanization in oocysts of plasmodium yoelii].to study the change of intracellular free ca2+ in the oocyst when it melanized and to find out the relationship between the melanized oocyst and its intracellular level of free ca2+ in a plasmodium-refractory strain of anopheles dirus.200312884616
malaria control in a forest camp in an oil exploration area of upper assam.assam, in north-east india, is extremely rich in hydrocarbon deposits and the oil industry is the major contributor to its economy. a large number of oil fields and related installations in assam are located in forest areas or on their fringes where malaria is a serious problem among field staff and security personnel, adversely affecting oil production. we carried out an operational research study for one year in a forest-based industrial security camp of dibrugarh district and developed an eff ...200312929855
comparison of artificial membrane feeding with direct skin feeding to estimate the infectiousness of plasmodium vivax gametocyte carriers to mosquitoes.the efficacy of a membrane-feeding apparatus as a means of infecting anopheles dirus mosquitoes with plasmodium vivax was compared with direct feeding of mosquitoes on gametocyte carriers. volunteers participating in the study were symptomatic patients reporting to malaria clinics in western thailand. direct mosquito feeds were conducted on 285 p. vivax-infected individuals. four methods of preparing blood for the membrane-feeding apparatus were evaluated. they included 1) replacement of patient ...200314695091
transmission-blocking activity of tafenoquine (wr-238605) and artelinic acid against naturally circulating strains of plasmodium vivax in thailand.the sporontocidal activity of tafenoquine (wr-238605) and artelinic acid was determined against naturally circulating isolates of plasmodium vivax in western thailand. primaquine was used as a negative control and a dihydroacridine-dione (wr-250547) was used as a positive control. laboratory-reared anopheles dirus mosquitoes were infected with p. vivax by allowing mosquitoes to feed on blood (placed in an artificial-membrane feeding apparatus) collected from gametocytemic volunteers reporting to ...200314695093
anopheles dirus and its role in malaria transmission in myanmar.anopheles dirus is one of the primary vectors of highly drug-resistant plasmodium falciparum, which causes cerebral malaria resulting in high mortality. mosquito collections were conducted in a forest wood-extraction area (bago division), an irrigated plain area near foothills (mandalay division), a coastal plain (from domestic wells in the mudon area, mon state) near the foothill area, as well as a hilly area (deep forest timber extraction camp, tanintharyi division) from may 1998 to march 2000 ...200314714666
seasonal abundance and blood feeding activity of anopheles minimus theobald (diptera: culicidae) in thailand.anopheline mosquito larvae and adults were sampled at ban pu teuy, tri-yok district, kanchanaburi province, western thailand, from january 2000 to december 2001. over the period of 2 yr, anopheles minimus sensu lato was the most commonly collected species, followed by anopheles swadiwongporni and anopheles dirus sensu lato; all three species are important vectors of malaria in thailand. attempted blood feeding by an. minimus occurred throughout the night, with two distinct feeding peaks: strong ...200314765665
[the internal control role of ribosomal protein s7 in the defense of anopheles dirus against plasmodium infection].to investigate the role of ribosomal protein s7 (rps7) in the defense of anopheles dirus against infection.200315108511
mosquito appetite for blood is stimulated by plasmodium chabaudi infections in themselves and their vertebrate hosts.arthropod vectors of disease may encounter more than one infected host during the course of their lifetime. the consequences of super-infection to parasite development are rarely investigated, but may have substantial epidemiological and evolutionary consequences.200415151700
catalytic and structural contributions for glutathione-binding residues in a delta class glutathione s-transferase.glutathione s-transferases (gsts) are dimeric proteins that play a major role in cellular detoxification. the gsts in mosquito anopheles dirus species b, an important malaria vector in south east asia, are of interest because they can play an important role in insecticide resistance. in the present study, we characterized the anopheles dirus (ad)gst d3-3 which is an alternatively spliced product of the adgst1as1 gene. the data from the crystal structure of gst d3-3 shows that ile-52, glu-64, ser ...200415182230
malaria transmission and major malaria vectors in different geographical areas of southeast asia.during the last decade, major progress in malaria control has been achieved in vietnam, laos and cambodia. however, malaria is still a potentially fatal disease in some hilly-forested areas and continues to be endemic in a few coastal foci. to estimate the risk that stems from the major vectors after a decade of intensive malaria control, an entomological study based on human landing collections was conducted between april 1998 and november 2000 in six study villages (four in vietnam, one in cam ...200415040560
infectivity of asymptomatic plasmodium-infected human populations to anopheles dirus mosquitoes in western thailand.the infectivity of plasmodium-infected humans in western thailand was estimated by feeding laboratory-reared anopheles dirus peyton and harrison mosquitoes on venous blood placed in a membrane-feeding apparatus. between may 2000 and november 2001, a total of 6,494 blood films collected during an active malaria surveillance program were checked by microscopy for the presence of plasmodium parasites: 3.3, 4.5, and 0.1% of slides were p. falciparum- (pf), p. vivax- (pv), and p. malariae (pm)-positi ...200415061279
excito-repellency of deltamethrin on the malaria vectors, anopheles minimus, anopheles dirus, anopheles swadiwongporni, and anopheles maculatus, in thailand.this study compared the behavioral avoidance responses of 4 mosquito malaria vectors, anopheles minimus, anopheles dirus, anopheles maculatus form b, and anopheles swadiwongporni, to deltamethrin, the primary insecticide used for indoor residual spraying for malaria vector control in thailand. six test populations. representing 4 laboratory colonies and 2 wild-caught populations, were observed during and after exposure to deltamethrin at the operational dose (0.02 g active ingredient/m2) in exci ...200415088704
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
additional observations on the sporozoite transmission of plasmodium knowlesi to monkeys.saimiri boliviensis monkeys were infected by the intravenous injection of 50 sporozoites of the h strain of plasmodium knowlesi dissected from the salivary glands of anopheles dirus mosquitoes; prepatent periods were 11, 12, 13, 13, 13, and 16 days. sporozoites of p. knowlesi stored frozen for 7 days, 53 days, 20 mo, 7 yr and 7 mo, and 11 yr and 5 mo induced infections in macaca mulatta monkeys with prepatent periods of 7, 6, 8, 10, and 7 days, respectively. after frozen storage for 11 yr and 5 ...200415357085
infectious reservoir of plasmodium infection in mae hong son province, north-west thailand.it was unknown whether the main reservoir of plasmodium falciparum and plasmodium vivax, which infects mosquitoes in thailand, was (a) in people feeling sufficiently ill with malaria to come to a clinic or (b) in people who had remained in their home villages with some fever symptoms or with none.200415385050
endemic malaria in four villages in attapeu province, lao pdr.a study was conducted in four villages in attapeu province, lao pdr in 2002 to determine malaria endemicity. the study villages were mixay, beng phoukham, phou vong and pier geo. mass blood surveys were conducted in may, august, and october. finger prick blood was collected for thick and thin blood film as well as for dipstick. the slide positivity rate was highest in phou hom in october (41.7%). plasmodium falciparum was the dominant species comprising more than 80% of the cases. as a whole, th ...200415689064
malaria transmission by anopheles dirus in attapeu province, lao pdr.a study was carried out in four malaria-endemic villages in attapeu province, in the southern region of lao pdr. all-night human landing collections were carried out in may, august, and october 2002, to determine malaria vectors. at the same time, mass blood surveys were also carried out in the same villages. anopheles dirus was the predominant species in three of the study villages. sporozoites were found only in an. drius from phou hom. however, in beng phoukham, an. dirus was positive for ooc ...200415691129
changes in malaria vector densities over a twenty-three year period in mae hong son province, northern thailand.mae hong son province in northwestern thailand has a long history of malaria. during the last two decades the province has had one of the highest malaria incidences of all provinces in thailand. data were analyzed to determine whether the vector populations were stable or increasing during the last two decades and to determine the seasonal prevalence of the main vectors, and whether or not they were related to the malaria transmission peak, in the wet season. we compiled and analyzed accumulated ...200415691130
laboratory and field trial of developing medicinal local thai plant products against four species of mosquito vectors.oils of syzygium aromaticum (clove) and zanthoxylum limonella (makaen), widely used essential oils for dental caries or flavoring of food in thailand, were prepared as 10 experimental repellent products in gel or cream form against aedes aegypti, culex quinquefasciatus, and anopheles dirus under laboratory conditions, using the human-arm-in-cage method. two products that gave the longest-lasting complete protection were selected to examine their repellency against a variety of mosquito species u ...200415691131
behavioural heterogeneity of anopheles species in ecologically different localities in southeast asia: a challenge for vector control.in southeast asia the biodiversity of anopheles species in the domestic environment is very high. only few species are considered major vectors throughout the region, whereas the vector status of other species varies from area to area. often it is difficult to identify an anopheles species as a malaria vector in areas with low malaria incidence. the behaviour of anopheles species largely determines their vector status, and insights into their behaviour are essential to evaluate the appropriatene ...200515730510
studies on two strains of plasmodium cynomolgi in new world and old world monkeys and mosquitoes.infections that cause the gombak and smithsonian strains of plasmodium cynomolgi were induced in macaca mulatta, aotus lemurinus griseimembra, aotus nancymai, and saimiri boliviensis monkeys. transmission of the gombak strain to aotus spp. monkeys was obtained by the injection of sporozoites dissected from the salivary glands of experimentally infected anopheles dirus and by the bites of infected an. dirus and anopheles farauti mosquitoes. two s. boliviensis monkeys were infected via the injecti ...200515986601
evaluation of procedures to determine absolute density of plasmodium vivax ookinetes.the ookinete is the key determinant of infection within the mosquito vector, yet there are few population studies of ookinetes in nature. this investigation compared different techniques used to estimate ookinete densities in mosquitoes. laboratory-reared anopheles dirus mosquitoes were fed on gametocytemic blood drawn from 7 plasmodium vivax patients at a malaria clinic in mae sot, thailand. at 20-26 hr, bloodmeals were excised. three techniques were evaluated, i.e., hemacytometer counts under ...200515986624
observations on the vietnam palo alto strain of plasmodium vivax in two species of aotus monkeys.thirty-three splenectomized aotus lemurinus griseimembra monkeys with no previous experience with malaria were infected with the vietnam palo alto strain of plasmodium vivax. the median maximum parasite count was 280,000/microl. nine splenectomized monkeys with previous infection with plasmodium falciparum had median maximum parasite counts of 120,000/microl. splenectomized aotus nancymai monkeys supported infections at a lower level. transmission via the bites of anopheles dirus mosquitoes was ...200515986626
infection of saimiri boliviensis monkeys with plasmodium coatneyi.abundant, apparently normally developing, liver-stage parasites of plasmodium coatneyi were demonstrated following injection of sporozoites dissected from the salivary glands of anopheles dirus mosquitoes. erythrocytic development was not demonstrated.200515986634
plasmodium ovale: parasite and disease.humans are infected by four recognized species of malaria parasites. the last of these to be recognized and described is plasmodium ovale. like the other malaria parasites of primates, this parasite is only transmitted via the bites of infected anopheles mosquitoes. the prepatent period in the human ranges from 12 to 20 days. some forms in the liver have delayed development, and relapse may occur after periods of up to 4 years after infection. the developmental cycle in the blood lasts approxima ...200516020691
comparative repellency of 38 essential oils against mosquito bites.the mosquito repellent activity of 38 essential oils from plants at three concentrations was screened against the mosquito aedes aegypti under laboratory conditions using human subjects. on a volunteer's forearm, 0.1 ml of oil was applied per 30 cm2 of exposed skin. when the tested oils were applied at a 10% or 50% concentration, none of them prevented mosquito bites for as long as 2 h, but the undiluted oils of cymbopogon nardus (citronella), pogostemon cablin (patchuli), syzygium aromaticum (c ...200516041723
epidemiology of malaria in attapeu province, lao pdr in relation to entomological parameters.surveys were conducted in malaria-endemic villages in the southern province of attapeu, lao pdr during various seasons over a 3-year period. all-night mosquito landing collections, blood surveys and a case-control study were conducted. plasmodium falciparum was the predominant species, and slide positivity rates were higher during the transition/dry season compared with the wet season. anopheles dirus a was found to be the primary vector, and sporozoite rates were highest during the transition/d ...200516112154
nasal immunization with a malaria transmission-blocking vaccine candidate, pfs25, induces complete protective immunity in mice against field isolates of plasmodium falciparum.malaria transmission-blocking vaccines based on antigens expressed in sexual stages of the parasites are considered one promising strategy for malaria control. to investigate the feasibility of developing noninvasive mucosal transmission-blocking vaccines against plasmodium falciparum, intranasal immunization experiments with pichia pastoris-expressed recombinant pfs25 proteins were conducted. mice intranasally immunized with the pfs25 proteins in the presence of a potent mucosal adjuvant choler ...200516239536
epidemiology of forest malaria in central vietnam: a large scale cross-sectional survey.in vietnam, a large proportion of all malaria cases and deaths occurs in the central mountainous and forested part of the country. indeed, forest malaria, despite intensive control activities, is still a major problem which raises several questions about its dynamics.a large-scale malaria morbidity survey to measure malaria endemicity and identify important risk factors was carried out in 43 villages situated in a forested area of ninh thuan province, south central vietnam. four thousand three h ...200516336671
screening for larvicidal activity in some thai plants against four mosquito vector species.ninety-six ethanolic extracts from various parts of 84 thai plant species were tested for their larvicidal activity against aedes aegypti mosquitoes. extracts from rhinacanthus nasutus, derris elliptica, trigonostemon reidioides, homalomena aromatica, stemona tuberosa and acorus calamus possessed high larvicidal activity, with lc50 values between 16.0 and 48.2 mg/l. petroleum ether (pe) and methanol (meoh) extracts were tested for their larvicidal activity against 4 mosquito vector species. the ...200516610643
evaluating the costs of mosquito resistance to malaria parasites.costly resistance mechanisms have been cited as an explanation for the widespread occurrence of parasitic infections, yet few studies have examined these costs in detail. a malaria-mosquito model has been used to test this concept by making a comparison of the fitness of highly susceptible lines of mosquitoes with lines that are resistant to infection. malaria infection is known to cause a decrease in fecundity and fertility of mosquitoes; resistant mosquitoes were thus predicted to be fitter th ...200516526504
an electron-sharing network involved in the catalytic mechanism is functionally conserved in different glutathione transferase classes.in anopheles dirus glutathione transferase d3-3, there are electrostatic interactions between the negatively charged glutamyl alpha-carboxylate group of glutathione, the positively charged arg-66, and the negatively charged asp-100. this ionic interaction is stabilized by a network of hydrogen bonds from ser-65, thr-158, thr-162, and a conserved water-mediated contact. this alternating ionic bridge interaction between negatively and positively charged residues stabilized by a network of hydrogen ...200516012173
polyphyly and gene flow between non-sibling heliconius species.the view that gene flow between related animal species is rare and evolutionarily unimportant largely antedates sensitive molecular techniques. here we use dna sequencing to investigate a pair of morphologically and ecologically divergent, non-sibling butterfly species, heliconius cydno and h. melpomene (lepidoptera: nymphalidae), whose distributions overlap in central and northwestern south america.200616630334
natural human humoral response to salivary gland proteins of anopheles mosquitoes in thailand.during blood feeding, arthropod vectors inject saliva into vertebrate hosts. the saliva is biochemically complex and pharmacologically active, and may play an important role in pathogen transmission. to examine whether mosquito saliva could elicit humoral immune response in humans under natural conditions, we have collected sera from malaria patients, healthy villagers, and people from a non-malarious region in thailand. here we have demonstrated that anti-anopheles salivary protein antibodies o ...200616530153
two serine proteases from anopheles dirus haemocytes exhibit changes in transcript abundance after infection of an incompatible rodent malaria parasite, plasmodium yoelii.serine proteases are involved in regulation of innate immune responses, such as haemolymph coagulation, melanization reaction and antimicrobial peptide synthesis. although several serine proteases have been characterized in anopheles gambiae (a. gambiae), few were cloned from other malaria vectors. in this study, we identified three cdna fragments of serine proteases (adsp1, adsp2 and adsp3) from haemocytes of an oriental malaria vector, anopheles dirus (a. dirus), by cloning of fragments amplif ...200616567047
sequence variation in the t-cell epitopes of the plasmodium falciparum circumsporozoite protein among field isolates is temporally stable: a 5-year longitudinal study in southern vietnam.in an effort to decipher the nature and extent of antigen polymorphisms of malaria parasites in a setting where malaria is hypomesoendemic, we conducted a 5-year longitudinal study (1998 to 2003) by sequencing the th2r and th3r epitopes of the circumsporozoite protein (csp) of 142 plasmodium falciparum field isolates from bao loc, vietnam. samples were collected during the high-transmission season, september through december 1998 (n = 43), as well as from july 2000 to august 2001 (n = 34), septe ...200616597843
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