| laboratory evaluation of trichophyton ajelloi, a fungal pathogen of anopheles stephensi and culex quinquefasciatus. | trichophyton ajelloi, a fungus isolated from soil, caused high larval mortality in anopheles stephensi and culex quinquefasciatus in the laboratory. the efficacy and toxicity of t. ajelloi against an. stephensi and cx. quinquefasciatus were evaluated at 6 different concentrations. at different concentrations of t. ajelloi, chitin synthesis in larval cuticle was adversely affected. larvae of 3rd-stage an. stephensi were more susceptible to t. ajelloi than were larvae of 1st, 2nd, and 4th stages a ... | 2000 | 11081656 |
| anopheles gambiae salivary gland proteins as putative targets for blocking transmission of malaria parasites. | anopheles gambiae is the primary vector of human malaria in sub-saharan africa. invasion of anopheles salivary glands by plasmodium sporozoites is a necessary step in the transmission of malaria and is likely to be mediated by specific receptor-ligand interactions. we are interested in identifying putative an a. gambiae salivary gland receptor or receptors for sporozoite invasion as a possible target for blocking malaria transmission. by using monoclonal antibodies against female-specific a. gam ... | 2000 | 11087838 |
| isolation and characterization of as60a, a transforming growth factor-beta gene, from the malaria vector anopheles stephensi. | we have isolated the first mosquito member of the tgf-beta superfamily, as60a. as60a is a single copy gene, approximately 5 kb in length and encodes eight exons. here we report the isolation and characterization of two of four transcripts produced from this gene. the transcripts as60a(1)and as60a(2)encode related 5'utr/exon 1 sequences. as60a is most similar to the 60a genes from drosophila and is thus a member of the dpp/bmp subfamily of the tgf-beta superfamily. the splice junction of intron 2 ... | 2001 | 11145845 |
| transcriptional complexity of the anopheles stephensi nitric oxide synthase gene. | anopheles stephensi nitric oxide synthase (asnos) is a single copy gene that shares significant structural homology with the three human nos genes and is inducibly expressed in plasmodium-infected mosquitoes. exon-specific northern analyses and exon-spanning polymerase chain reaction amplification were used to further characterize transcription from this gene. a total of 18-22 asnos transcripts, ranging in size from 1.0 to 7.5 kb, were detected in replicated northern blots from three separate co ... | 2001 | 11167094 |
| interleukin-12- and gamma interferon-dependent protection against malaria conferred by cpg oligodeoxynucleotide in mice. | unmethylated cpg dinucleotides in bacterial dna or synthetic oligodeoxynucleotides (odns) cause b-cell proliferation and immunoglobulin secretion, monocyte cytokine secretion, and activation of natural killer (nk) cell lytic activity and gamma interferon (ifn-gamma) secretion in vivo and in vitro. the potent th1-like immune activation by cpg odns suggests a possible utility for enhancing innate immunity against infectious pathogens. we therefore investigated whether the innate immune response co ... | 2001 | 11179339 |
| susceptibility of species a, b, and c of anopheles culicifacies complex to plasmodium yoelii yoelii and plasmodium vinckei petteri infections. | the comparative susceptibilities of colonized species a, b, and c of anopheles culicifacies complex and anopheles stephensi were determined for 2 rodent malaria parasites plasmodium vinckei petteri and plasmodium yoelii yoelii. all the 3 members of the complex were found to support complete sporogony with varying success. controls, a. stephensi, become readily infected, with >70% developing oocysts. of the test groups, species a had the highest percentage of mosquitoes with oocysts (>25%) and sp ... | 2000 | 11191914 |
| [use of the recombinant bacterial strain to control blood-sucking mosquito larvae]. | the recombinant strain of methylobacillus flagellatum with the cloned synthesis gene cry 4b of the toxic bac. thuringiensis var. israelensis protein proved to be effective against larvae of the anopheles stephensi, an. atroparvus, an. pulcherrimus, an. superpictus, and an. sacharovi cultured in the laboratory. the use of m. flagellatum in combination with t. pyriformis may greatly expand the scope of use of the recombinant strain to control malaria mosquito larvae. their combined use shows a 6-f ... | 1999 | 11221007 |
| lack of cross-resistance to cry19a from bacillus thuringiensis subsp. jegathesan in culex quinquefasciatus (diptera: culicidae) resistant to cry toxins from bacillus thuringiensis subsp. israelensis. | culex quinquefasciatus mosquitoes with high levels of resistance to single or multiple toxins from bacillus thuringiensis subsp. israelensis were tested for cross-resistance to the bacillus thuringiensis subsp. jegathesan polypeptide cry19a. no cross-resistance was detected in mosquitoes that had been selected with the cry11a, cry4a and cry4b, or cry4a, cry4b, cry11a, and cyta toxins. a low but statistically significant level of cross-resistance, three to fourfold, was detected in the colony sel ... | 2001 | 11282656 |
| epidemiological profile of malaria in a university hospital in the eastern region of saudi arabia. | to study the epidemiological, clinical and hematological profile of laboratory-diagnosed malaria cases at king fahd hospital of the university, al-khobar, saudi arabia, during the period from january 1990 to december 1999, and to provide suitable recommendations accordingly. | 2001 | 11299407 |
| anti-mosquito midgut antibodies block development of plasmodium falciparum and plasmodium vivax in multiple species of anopheles mosquitoes and reduce vector fecundity and survivorship. | the mosquito midgut plays a central role in the sporogonic development of malaria parasites. we have found that polyclonal sera, produced against mosquito midguts, blocked the passage of plasmodium falciparum ookinetes across the midgut, leading to a significant reduction of infections in mosquitoes. anti-midgut mabs were produced that display broad-spectrum activity, blocking parasite development of both p. falciparum and plasmodium vivax parasites in five different species of mosquitoes. in ad ... | 2001 | 11309510 |
| human antibodies against plasmodium falciparum liver-stage antigen 3 cross-react with plasmodium yoelii preerythrocytic-stage epitopes and inhibit sporozoite invasion in vitro and in vivo. | the plasmodium falciparum liver-stage antigen 3 (lsa3), a recently identified preerythrocytic antigen, induces protection against malaria in chimpanzees. using antibodies from individuals with hyperimmunity to malaria affinity purified on recombinant or synthetic polypeptides of lsa3, we identified four non-cross-reactive b-cell epitopes in plasmodium yoelii preerythrocytic stages. on sporozoites the p. yoelii protein detected has a molecular mass similar to that of lsa3. t-cell epitopes cross-r ... | 2001 | 11349050 |
| knockout of the rodent malaria parasite chitinase pbcht1 reduces infectivity to mosquitoes. | during mosquito transmission, malaria ookinetes must cross a chitin-containing structure known as the peritrophic matrix (pm), which surrounds the infected blood meal in the mosquito midgut. in turn, ookinetes produce multiple chitinase activities presumably aimed at disrupting this physical barrier to allow ookinete invasion of the midgut epithelium. plasmodium chitinase activities are demonstrated targets for human and avian malaria transmission blockade with the chitinase inhibitor allosamidi ... | 2001 | 11349074 |
| disruption of plasmodium falciparum chitinase markedly impairs parasite invasion of mosquito midgut. | to initiate invasion of the mosquito midgut, plasmodium ookinetes secrete chitinolytic activity to penetrate the peritrophic matrix surrounding the blood meal. while ookinetes of the avian malaria parasite plasmodium gallinaceum appear to secrete products of two chitinase genes, to date only one chitinase gene, pfcht1, has been identified in the nearly completed plasmodium falciparum strain 3d7 genome database. to test the hypothesis that the single identified chitinase of p. falciparum is neces ... | 2001 | 11349075 |
| the binding of the circumsporozoite protein to cell surface heparan sulfate proteoglycans is required for plasmodium sporozoite attachment to target cells. | the major surface protein of malaria sporozoites, the circumsporozoite protein, binds to heparan sulfate proteoglycans on the surface of hepatocytes. it has been proposed that this binding event is responsible for the rapid and specific localization of sporozoites to the liver after their injection into the skin by an infected anopheline mosquito. previous in vitro studies performed under static conditions have failed to demonstrate a significant role for heparan sulfate proteoglycans during spo ... | 2001 | 11352923 |
| nitric oxide synthase is induced in sporulation of physarum polycephalum. | the myxomycete physarum polycephalum expresses a calcium-independent nitric oxide (no) synthase (nos) resembling the inducible nos isoenzyme in mammals. we have now cloned and sequenced this, the first nonanimal nos to be identified, showing that it shares < 39% amino acid identity with known noss but contains conserved binding motifs for all nos cofactors. it lacks the sequence insert responsible for calcium dependence in the calcium-dependent nos isoenzymes. nos expression was strongly up-regu ... | 2001 | 11358872 |
| short report: failure to select for chloroquine- or mefloquine-resistant plasmodium berghei through drug pressure in anopheles stephensi mosquitoes. | we investigated whether chloroquine- or mefloquine-resistant plasmodium berghei could be selected through drug pressure applied during continuous cyclical transmission in anopheles stephensi mosquitoes. mosquitoes were infected by feeding them on mice previously inoculated with a drug-sensitive clone of p. berghei anka. mosquitoes ingested mefloquine or chloroquine with the infectious blood-meal, or by feeding on a drug-treated (uninfected) mouse 4 or 10 days after the infectious blood-meal. twe ... | 2000 | 11388501 |
| the influence of host haematocrit on the blood feeding success of anopheles stephensi: implications for enhanced malaria transmission. | two studies were carried out to determine the effect of the rodent malaria plasmodium yoelii nigeriensis on the blood feeding success of anopheles stephensi. initially, pairs of mice with similar packed cell volume (pcv) (measured by haematocrit) were selected. following infection of one of the pair its pcv gradually fell. at various times post-infection, a comparison was made of the bloodmeal size (haemoglobin content) of mosquitoes feeding on these mice. the bloodmeal sizes increased with para ... | 2001 | 11393821 |
| control of malaria in pakistan by applying deltamethrin insecticide to cattle: a community-randomised trial. | the standard method of malaria control in south asia, indoor spraying of houses with residual insecticide, is becoming prohibitively expensive to implement and new approaches are needed. since the region's vector mosquitoes feed predominantly on domestic animals and only secondarily on human beings, to apply insecticide to surfaces of cattle instead might be more costeffective. we aimed to investigate whether domestic livestock treated with deltamethrin (applied by a sponging method) would prove ... | 2001 | 11410192 |
| plasmodium malariae blood-stage dynamics. | we examine the dynamics of parasitemia, fever, and gametocytemia reflected in the preintervention charts of 180 malaria-naive u.s. neurosyphilis patients infected with the usphs strain of plasmodium malariae, for malariatherapy, focusing on the 84 charts for which more than 35 days of patency preceded intervention and daily records encompassed 92% or more of the duration of each infection. inoculum size did not influence any outcome variable. fevers (days with temperatures > or =101 f) followed ... | 2001 | 11426728 |
| effect of xanthurenic acid on infectivity of plasmodium falciparum to anopheles stephensi. | terminally differentiated malarial gametocytes remain in the vertebrate circulation in a developmentally arrested state until they are taken up by the mosquito. the gametocytes then undergo gametogenesis in the mosquito mid-gut within minutes after ingestion of the infected blood meal. the male gametogenesis (exflagellation) can be triggered by the combination of a decrease in temperature of at least 5 degrees c and a simultaneous increase in ph between 8.0 and 8.3. xanthurenic acid, which is pr ... | 2001 | 11429178 |
| interaction between host complement and mosquito-midgut-stage plasmodium berghei. | after ingestion by mosquitoes, gametocytes of malaria parasites become activated and form extracellular gametes that are no longer protected by the red blood cell membrane against immune effectors of host blood. we have studied the action of complement on plasmodium developmental stages in the mosquito blood meal using the rodent malaria parasite plasmodium berghei and rat complement as a model. we have shown that in the mosquito midgut, rat complement components necessary to initiate the altern ... | 2001 | 11447187 |
| dendritic cells can initiate protective immune responses against malaria. | an understanding of the antigen presentation mechanisms that mediate induction of protective immune responses against malaria is essential for the development of successful immunization approaches. here we show that dendritic cells presenting plasmodium yoelii sporozoite antigens are able to activate specific cd4(+) and cd8(+) t cells and initiate protective immune responses against malaria in mice. | 2001 | 11447201 |
| laboratory evaluation of fipronil, a phenylpyrazole insecticide, against adult anopheles (diptera: culicidae) and investigation of its possible cross-resistance with dieldrin in anopheles stephensi. | adult mosquitoes from two strains of anopheles gambiae and from three strains of anopheles stephensi were exposed to 0.25% fipronil-treated papers in who test kits or to 500 mg fipronil m-2 impregnated mosquito netting in bioassay spheres. for comparison, tests were also carried out with the pyrethroid permethrin, using the same methods and doses, and on papers treated with 0.4 and 4% of the cyclodiene insecticide dieldrin. compared with the same doses of permethrin, fipronil showed less and del ... | 2001 | 11455631 |
| chrysosporium tropicum efficacy against anopheles stephensi larvae in the laboratory. | the keratinophilic soil fungus chrysosporium tropicum was evaluated as a biological control agent against anopheles stephensi larvae in the laboratory. culture filtrates of c. tropicum were found to be toxic to an. stephensi larvae at various concentrations. the ranges of the 50% lethal concentration (lc50) values of fungal filtrates were 16.60-17.78, 12.02-12.88, and 34.67-35.48 microl/ml against 1st-, 2nd-, and 3rd-stage larvae, respectively. the ranges of lc99 values were 38.90-63.10, 12.02-2 ... | 2001 | 11480820 |
| concurrent control of mosquitoes and domestic pests by use of deltamethrin-treated curtains in the new delhi municipal committee, india. | a field trial was conducted in block f of the moti bagh area of new delhi municipal committee to demonstrate composite control of anopheles stephensi and aedes aegypti by spraying deltamethrin at 100 mg/m2 on window and door curtains of habitations. results revealed drastic reduction (87.9-93.7%, p < 0.05) of target species in the experimental area. the impact of deltamethrin-treated curtains was also evident against nontarget species (67.9-85.7%. p < 0.05). treated curtains provided 100% kill o ... | 2001 | 11480821 |
| p25 and p28 proteins of the malaria ookinete surface have multiple and partially redundant functions. | the ookinete surface proteins (p25 and p28) are proven antimalarial transmission-blocking vaccine targets, yet their biological functions are unknown. by using single (sko) and double gene knock-out (dko) plasmodium berghei parasites, we show that p25 and p28 share multiple functions during ookinete/oocyst development. in the midgut of mosquitoes, the formation of ookinetes lacking both proteins (dko parasites) is significantly inhibited due to decreased protection against lethal factors, includ ... | 2001 | 11483501 |
| exploring the transcriptome of the malaria sporozoite stage. | most studies of gene expression in plasmodium have been concerned with asexual and/or sexual erythrocytic stages. identification and cloning of genes expressed in the preerythrocytic stages lag far behind. we have constructed a high quality cdna library of the plasmodium sporozoite stage by using the rodent malaria parasite p. yoelii, an important model for malaria vaccine development. the technical obstacles associated with limited amounts of rna material were overcome by pcr-amplifying the tra ... | 2001 | 11493695 |
| midgut specific immune response of vector mosquito anopheles stephensi to malaria parasite plasmodium. | innate immune-related polypeptides expression in midgut in the ageing vector mosquito a. stephensi following infection by malaria parasite, plasmodium yoelii yoelii has been studied. twenty polypeptides were induced by an infected blood meal during various stages of adult life. a 24 kda polypeptide was induced generally in most of the stages. maximum parasite induced polypeptides i.e. 22, 33, 111, 122, 127, 140, 143 and 146 kda were found in 5 days of post blood feeding (pbf) which coincides wit ... | 2001 | 11495292 |
| complete, long-lasting protection against malaria of mice primed and boosted with two distinct viral vectors expressing the same plasmodial antigen. | we report that complete protection against malaria and total inhibition of liver stage development and parasitemia was obtained in 100% of balb/c mice primed with a replication-defective recombinant adenovirus expressing the circumsporozoite (cs) protein of plasmodium yoelii (adpycs), followed by a booster with an attenuated recombinant vaccinia virus, expressing the same malaria antigen, vacpycs. we found increased levels of activated cs-specific cd8(+) and cd4(+) t cells, higher anti-sporozoit ... | 2001 | 11553779 |
| possibility of false-positive detection for sporozoites in mosquitos (diptera: culicidae) by nested polymerase chain reaction using plasmodium yoelii genomic dna. | anopheles stephensi liston and an. saperoi bohart and ingram infected with the rodent malaria parasite plasmodium yoelii nigeriense. they were examined 12 and 19 days after blood feeding for sporozoites in head with anterior thorax (ht) and oocysts in abdomen with posterior thorax (ab) by light microscopy and by the nested polymerase chain reaction (nested pcr-based on the amplification of the sequences of the small subunit ribosomal rna gene). the detection rate of parasite dna by nested pcr in ... | 2001 | 11556576 |
| characterization and identification of exflagellation-inducing factor in the salivary gland of anopheles stephensi (diptera: culicidae). | gamete activation factor (gaf) induces exflagellation of plasmodium microgametes. we found gaf in the salivary glands of female mosquitoes, anopheles stephensi. the exflagellation was induced in a concentration-dependent manner in the supernatant of salivary gland's crude homogenate. the exflagellation-inducing activity in the salivary gland was higher than that in the midgut and the head. gaf in the salivary glands was found to be heat stable and low molecular weight (<3000 molecular weight). a ... | 2001 | 11573943 |
| anti-mosquito ovary antibodies reduce the fecundity of anopheles stephensi (diptera:insecta). | rabbit antibodies to five antigens (aj** 29, 35, 43, 64, and 80 kda) derived from the ovaries of anopheles stephensi tended to reduce the number of eggs produced. ingestion of anti-mosquito ovary antibodies did not show a detectable effect on the mortality of mosquitoes. antisera raised against an. stephensi ovaries showed cross-reactivity in other tissues and in the ovaries of other anopheles spp. by western blotting. the results indicate that anti-mosquito ovary antibodies have the potential t ... | 2001 | 11754155 |
| cloning and characterization of the crystal protein-encoding gene of bacillus thuringiensis subsp. yunnanensis. | molecular cloning and characterization of a novel cry gene, cry32aa, of bacillus thuringiensis subsp. yunnanensis was carried out. the cry32aa protein was predicted to have a molecular mass of 139.2 kda and was found to have an unusual 42-amino-acid-long tail at the c terminus. the cry32aa gene was localized on the 103-mda plasmid of the organism. bioassays showed no toxicity against several moths and mosquitoes. however, it exhibited weak toxicity against larvae of the diamondback moth, plutell ... | 2002 | 11772653 |
| plasmodium knowlesi provides a rapid in vitro and in vivo transfection system that enables double-crossover gene knockout studies. | transfection technology for malaria parasites provides a valuable tool for analyzing gene function and correlating genotype with phenotype. transfection models are even more valuable when appropriate animal models are available in addition to complete in vitro systems to be able to fully analyze parasite-host interactions. here we describe the development of such a model by using the nonhuman primate malaria plasmodium knowlesi. blood-stage parasites were adapted to long-term in vitro culture. i ... | 2002 | 11796595 |
| what's buzzing? mosquito genomics and transgenic mosquitoes. | genome projects and associated technologies are now being established for mosquito species that are vectors of human disease. the recent announcement of an award by the national institute of allergy and infectious diseases (niaid) to celera genomics to sequence the anopheles gambiae genome will further accelerate the completion of the sequencing of this genome. completion of the an. gambiae sequence will mean that the genomes of all three organisms involved in the transmission of falciparum mala ... | 2002 | 11835673 |
| levels of circumsporozoite protein in the plasmodium oocyst determine sporozoite morphology. | the sporozoite stage of the plasmodium parasite is formed by budding from a multinucleate oocyst in the mosquito midgut. during their life, sporozoites must infect the salivary glands of the mosquito vector and the liver of the mammalian host; both events depend on the major sporozoite surface protein, the circumsporozoite protein (cs). we previously reported that plasmodium berghei oocysts in which the cs gene is inactivated do not form sporozoites. here, we analyzed the ultrastructure of p.ber ... | 2002 | 11927543 |
| plasmodium sporozoite invasion into insect and mammalian cells is directed by the same dual binding system. | plasmodium sporozoites, the transmission form of the malaria parasite, successively invade salivary glands in the mosquito vector and the liver in the mammalian host. sporozoite capacity to invade host cells is mechanistically related to their ability to glide on solid substrates, both activities depending on the transmembrane protein trap. here, we show that loss-of- function mutations in two adhesive modules of the trap ectodomain, an integrin-like a-domain and a thrombospondin type i repeat, ... | 2002 | 11927544 |
| induced immunity against the mosquito anopheles stephensi (diptera: culicidae): effects of cell fraction antigens on survival, fecundity, and plasmodium berghei (eucoccidiida: plasmodiidae) transmission. | two subeellular fractions from the midgut of the malaria mosquito anopheles stephensi (liston) were used to immunize balb/c mice. mice were subsequently infected with the rodent malaria parasite plasmodium berghei (vineke & lips), and the effects of anti-mosquito immunity on mosquito survival and fecundity and on parasite transmission were investigated. mosquitoes were infected directly from mice (in vivo) or by feeding cultured ookinetes through a membrane (in vitro). infections were monitored ... | 2002 | 11931258 |
| expression of d7 and d7-related proteins in the salivary glands of the human malaria mosquito anopheles stephensi. | full-length cdna clones encoding d7 (ansd7) and d7-related (ansd7r1) secreted salivary gland proteins were isolated from anopheles stephensi. corresponding proteins were separated by sds-page and analysed by n-terminal sequencing, which also identified a second d7-related protein (ansd7r2). ansd7 encodes a protein of 37 kda, ansd7r1 of 18 kda, and ansd7r2 of 16 kda. polyclonal antibodies against recombinant ansd7 showed immunological cross-reactivity with the d7-related proteins, and alignment d ... | 2002 | 12000641 |
| genetic and environmental determinants of malaria parasite virulence in mosquitoes. | models of malaria epidemiology and evolution are frequently based on the assumption that vector-parasitic associations are benign. implicit in this assumption is the supposition that all plasmodium parasites have an equal and neutral effect on vector survival, and thus that there is no parasite genetic variation for vector virulence. while some data support the assumption of avirulence, there has been no examination of the impact of parasite genetic diversity. we conducted a laboratory study wit ... | 2002 | 12065037 |
| [continuous cultivation of a large number of plasmodium falciparum gametocytes in carbon dioxide incubator]. | to establish a method for continuously cultivating a large number of p. falciparum gametocytes in vitro using carbon dioxide incubator. | 1998 | 12078278 |
| comparison of three pyrethroid treatments of top-sheets for malaria control in emergencies: entomological and user acceptance studies in an afghan refugee camp in pakistan. | insecticide-treated bedding materials (sheets and blankets) could be protective against vectors of malaria and leishmaniasis--especially in complex emergencies, epidemics and natural disasters where people are more likely to sleep in exposed situations. comparison of cotton top-sheets impregnated with different pyrethroids (permethrin 500 mg/m2, deltamethrin 25 mg/m2 or alphacypermethrin 25 mg/m2) for effectiveness against mosquitoes (diptera: culicidae) was undertaken in a refugee camp in pakis ... | 2002 | 12109715 |
| comparative toxicity of selected larvicidal formulations against anopheles stephensi liston and aedes aegypti linn. | toxicity of selected larvicidal formulations of bacillus sphaericus, bacillus thuringiensis h-14 israelensis (bti) and insect growth regulators was determined against anopheles stephensi and aedes aegypti, the two major urban mosquito vectors of malaria and dengue fever in india respectively. the study revealed that the formulations of bacillus thuringiensis h-14 and igr compounds were highly toxic against both the mosquito species but bacillus sphaericus formulation was less toxic against aedes ... | 2001 | 12170930 |
| nitric oxide limits parasite development in vectors and in invertebrate intermediate hosts. | nitric oxide (no) possesses antiparasitic effects on both protozoa and metazoa in vertebrate definitive and intermediate hosts. inducible no limits parasite development also in rhodnius prolixus and anopheles stephensi, the natural vectors of human trypanosomiasis and malaria respectively, and in the snail biomphalaria glabrata, a natural invertebrate intermediate host of human schistosomiasis. therefore, no limits trypanosoma, plasmodium, and schistosoma development at all stages of the parasit ... | 2002 | 12049194 |
| maebl is essential for malarial sporozoite infection of the mosquito salivary gland. | malarial sporozoites mature in the oocysts formed in the mosquito midgut wall and then selectively invade the salivary glands, where they wait to be transmitted to the vertebrate host via mosquito bite. invasion into the salivary gland has been thought to be mediated by specific ligand-receptor interactions, but the molecules involved in these interactions remain unknown. maebl is a single transmembrane-like protein that is structurally related to merozoite adhesive proteins. we found maebl of t ... | 2002 | 12021311 |
| a mosquito salivary protein inhibits activation of the plasma contact system by binding to factor xii and high molecular weight kininogen. | the salivary glands of female mosquitoes contain a variety of bioactive substances that assist their blood-feeding behavior. here, we report a salivary protein of the malarial vector mosquito, anopheles stephensi, that inhibits activation of the plasma contact system. this factor, named hamadarin, is a 16-kda protein and a major component of the saliva of this mosquito. assays using human plasma showed that hamadarin dose-dependently inhibits activation of the plasma contact system and subsequen ... | 2002 | 12011093 |
| a rodent malaria, plasmodium berghei, is experimentally transmitted to mice by merely probing of infective mosquito, anopheles stephensi. | we found that infection of a rodent malaria, plasmodium berghei, occurred when the sporozoites were injected into the skin, the muscle, the peritoneal cavity and the tail end. mice, which were injected with sporozoites in the tail end and had the site cut 5 min later, did not develop malaria. we also found that mice developed malaria when malaria infective mosquitoes, anopheles stephensi, were forced not to take blood but only to probe into the skin. moreover, the mice probed by the infective mo ... | 2002 | 11880224 |
| prevention of malaria in afghanistan through social marketing of insecticide-treated nets: evaluation of coverage and effectiveness by cross-sectional surveys and passive surveillance. | malaria is often a major health problem in countries undergoing war or conflict owing to breakdown of health systems, displacement of vulnerable populations, and the increased risk of epidemics. after 23 years of conflict, malaria has become prevalent in many rural areas of afghanistan. from 1993 to the present, a network of non-governmental organizations, co-ordinated by healthnet international, has operated a programme of bednet sales and re-treatment in lowland areas. to examine whether a str ... | 2002 | 12358615 |
| characterization of cyt2bc toxin from bacillus thuringiensis subsp. medellin. | we cloned and sequenced a new cytolysin gene from bacillus thuringiensis subsp. medellin. three is240-like insertion sequence elements and the previously cloned cyt1ab and p21 genes were found in the vicinity of the cytolysin gene. the cytolysin gene encodes a protein 29.7 kda in size that is 91.5% identical to cyt2ba from bacillus thuringiensis subsp. israelensis and has been designated cyt2bc. inclusions containing cyt2bc were purified from the crystal-negative strain spl407 of b. thuringiensi ... | 2002 | 11872472 |
| insecticide susceptibility status of anopheles stephensi (liston) in calcutta, west bengal. | | 2000 | 11820082 |
| novel cost-effective method of screening soils for the presence of mosquito-pathogenic bacilli. | the aim was to simplify the cumbersome conventional process of isolating virulent bacilli, which involves isolating all bacilli strains from a source followed by screening for strains that are effective for bio-control of mosquito vectors. | 2002 | 12460424 |
| piggybac-mediated germline transformation of the malaria mosquito anopheles stephensi using the red fluorescent protein dsred as a selectable marker. | it is estimated that every year malaria infects approximately 300 million people and accounts for the death of 2 million individuals. the plasmodium parasites that cause malaria in humans are transmitted exclusively by mosquito species belonging to the anopheles genus. the recent development of a gene transfer technology for anopheles stephensi mosquitoes, using the minos transposable element marked with the enhanced green fluorescent protein egfp (catteruccia, f., nolan, t., loukeris, t. g., bl ... | 2002 | 11805082 |
| adaptation of a strain of plasmodium vivax from india to new world monkeys, chimpanzees, and anopheline mosquitoes. | a strain of plasmodium vivax from india was adapted to develop in splenectomized saimiri boliviensis, aotus lemurinus griseimembra, a vociferans, a. nancymai, a. azarae boliviensis, hybrid aotus monkeys, and splenectomized chimpanzees. infections were induced via the inoculation of sporozoites dissected from the salivary glands of anopheles stephensi and an. dirus mosquitoes to 12 aotus and 8 saimiri monkeys; transmission via the bites of infected an. stephensi was made to 1 aotus monkey and 1 c ... | 2001 | 11780828 |
| a comparative genomic analysis of two distant diptera, the fruit fly, drosophila melanogaster, and the malaria mosquito, anopheles gambiae. | genome evolution entails changes in the dna sequence of genes and intergenic regions, changes in gene numbers, and also changes in gene order along the chromosomes. genes are reshuffled by chromosomal rearrangements such as deletions/insertions, inversions, translocations, and transpositions. here we report a comparative study of genome organization in the main african malaria vector, anopheles gambiae, relative to the recently determined sequence of the drosophila melanogaster genome. the ances ... | 2002 | 11779831 |
| blocking of malaria parasite development in mosquito and fecundity reduction by midgut antibodies in anopheles stephensi (diptera: culicidae). | rabbits were immunized three times with extracts of anopheles stephensi midgut. immunized rabbits showed a high titer of antibodies when characterized by elisa. we investigated the effect of anti-mosquito midgut antibodies on mosquito fecundity, longevity, mortality, engorgement, and the development of the malaria parasite in mosquitoes. fecundity was reduced significantly (38%) and similarly hatchability by about 43.5%. there was no statistically significant effect on mortality, longevity, and ... | 2003 | 12529861 |
| recent advances in insect olfaction, specifically regarding the morphology and sensory physiology of antennal sensilla of the female sphinx moth manduca sexta. | the antennal flagellum of female manduca sexta bears eight sensillum types: two trichoid, two basiconic, one auriculate, two coeloconic, and one styliform complex sensilla. the first type of trichoid sensillum averages 34 microm in length and is innervated by two sensory cells. the second type averages 26 microm in length and is innervated by either one or three sensory cells. the first type of basiconic sensillum averages 22 microm in length, while the second type averages 15 microm in length. ... | 2001 | 11754510 |
| 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 ... | 2001 | 11687659 |
| genetics of mefloquine resistance in the rodent malaria parasite plasmodium chabaudi. | the genetic determinants of resistance to mefloquine in malaria parasites are unclear. some studies have implied that amplification of, or mutations in, the multidrug resistance gene pfmdr1 in plasmodium falciparum may be involved. using the rodent malaria model plasmodium chabaudi, we investigated the role of the orthologue of this gene, pcmdr1, in a stable mefloquine-resistant mutant, as(15mf/3), selected from a sensitive clone. pcmdr1 exists as a single copy gene on chromosome 12 of the sensi ... | 2003 | 12543682 |
| malaria-induced apoptosis in mosquito ovaries: a mechanism to control vector egg production. | many insects are able to adjust their egg production according to physiological conditions such as nutrient supply and mating success. one way in which this is achieved is by resorption of some, or all, of the ovarian follicles at some stage during oogenesis. we have shown that the mosquito anopheles stephensi responds in this manner when ookinetes of the malaria parasite plasmodium yoelii nigeriensis first begin to invade the midgut. little is known about the initiation and regulation of follic ... | 2001 | 11683433 |
| [relationship between hemolymph phenol oxidase and melanization of oocysts of plasmodium yoelii in anopheles stephensi]. | to explore the relationship between the hemolymph phenol oxidase and melanization of oocysts. | 2000 | 12567462 |
| [effect of anti-mosquito-midgut antibodies on the development of oocysts of plasmodium yoelii in anopheles stephensi]. | to study the effect of anti-mosquito-midgut antibodies on the development of p. yoelii in a. stephensi. | 2000 | 12567656 |
| immuno-electron microscopic observation of plasmodium berghei ctrp localization in the midgut of the vector mosquito anopheles stephensi. | the subcellular localization of plasmodium berghei circumsporozoite protein and thrombospondin-related adhesive protein (pbctrp) in the invasive stage ookinete of p. berghei was studied in the midgut of anopheles stephensi by immuno-electron microscopic observations using polyclonal antibodies and immuno-gold labeling. pbctrp was found to be associated with the micronemes of a mature ookinete throughout the movement from the endoperitrophic space to the basal lamina of the midgut epithelium. pbc ... | 2002 | 12197111 |
| effect of anti-mosquito hemolymph antibodies on fecundity and on the infectivity of malarial parasite plasmodium vivax to anopheles stephensi (diptera:insecta). | rabbit antibodies to hemolymph antigens (102.5, 101, 100, 96, 88, 80, 64, 55, 43, 29, and 23 kda) of anopheles stephensi reduced fecundity as well as viability in an. stephensi. however, ingestion of these antibodies was not associated with a marked effect on the engorgement of mosquitoes but egg laying was significantly delayed. antisera raised against hemolymph proteins were also used to identify cross reactive antigens/epitopes present in other tissues by western blotting, as well as by in vi ... | 2002 | 12195047 |
| impact of genetic manipulation on the fitness of anopheles stephensi mosquitoes. | genetic modification of mosquitoes offers exciting possibilities for controlling malaria, but success will depend on how transformation affects the fitness of modified insects. the expression of an exogenous gene, the mutations caused by its insertion, and inbreeding while transformed lines are established can all lead to reductions in fitness. factors influencing fitness were investigated in cage experiments with four lines of transgenic anopheles stephensi, a vector species of human malaria. t ... | 2003 | 12595691 |
| sex-specific and blood meal-induced proteins of anopheles gambiae midguts: analysis by two-dimensional gel electrophoresis. | anopheles gambiae is the main vector of plasmodium falciparum in africa. the mosquito midgut constitutes a barrier that the parasite must cross if it is to develop and be transmitted. despite the central role of the mosquito midgut in the host/parasite interaction, little is known about its protein composition. characterisation of an. gambiae midgut proteins may identify the proteins that render an. gambiae receptive to the malaria parasite. | 2003 | 12605724 |
| two new triterpenoids from azadirachta indica and their insecticidal activity. | two new triterpenoids, 22,23-dihydronimocinol (1) and desfurano-6alpha-hydroxyazadiradione (2), were isolated from a methanolic extract of the fresh leaves of azadirachta indica (neem) along with a known meliacin, 7alpha-senecioyl-(7-deacetyl)-23-o-methylnimocinolide. the structures of 1 and 2 were elucidated through spectral and chemical studies. compounds 1 and 2 showed mortality for fourth instar larvae of the mosquito (anopheles stephensi), with lc(50) values of 60 and 43 ppm, respectively. | 2002 | 12193038 |
| short-term antigen presentation and single clonal burst limit the magnitude of the cd8(+) t cell responses to malaria liver stages. | malaria sporozoites induce swift activation of antigen-specific cd8(+) t cells that inhibit the intracellular development of liver-stage parasites. the length of time of functional in vivo antigen presentation, estimated by monitoring the activation of antigen-specific cd8(+) t cells, is of short duration, with maximum t cell activation occurring within the first 8 h after immunization and lasting approximately 48 h. although the magnitude of the cd8(+) t cell response closely correlates with th ... | 2002 | 12185251 |
| field evaluation of bacillus thuringiensis var. israelensis (bacticide) against anopheles stephensi breeding in calcutta city. | | 2001 | 12170935 |
| bee venom phospholipase inhibits malaria parasite development in transgenic mosquitoes. | malaria kills millions of people every year, and new control measures are urgently needed. the recent demonstration that (effector) genes can be introduced into the mosquito germ line to diminish their ability to transmit the malaria parasite offers new hope toward the fight of the disease (ito, j., ghosh, a., moreira, l. a., wimmer, e. a. & jacobs-lorena, m. (2002) nature, 417, 452-455). because of the high selection pressure that an effector gene imposes on the parasite population, development ... | 2002 | 12167627 |
| post-bloodmeal diuretic shedding of hepatitis b virus by mosquitoes (diptera: culicidae). | persistence and diuretic shedding of hepatitis b virus (hbv) by mosquitoes (diptera: culicidae) was studied by using infectious blood feedings, intrathoracic inoculations, and detection of virus by polymerase chain reaction (pcr) and southern hybridization. results showed that both anopheles stephensi liston and ochlerotatus triseriatus (say) shed hbv during diuresis for up to 72 h after feeding on an hbv-positive serum drawn from a human donor. hbv did not persist in the bodies of either an. st ... | 2002 | 12144291 |
| plasmodium yoelii: semiquantitative analyses of circumsporozoite protein gene expression during the sporogonic development of p. y. yoelii and p. y. nigeriensis in the mosquito vector anopheles stephensi. | malaria infection in the mosquito vector can be modulated by the vertebrate host, mosquito factors, and interactions between different parasite populations. modulation of parasite development can be assessed through the study of gene expression. the present report describes a specific, sensitive, and nonradioactive method that permits assessment of parasite load and quantification of circumsporozoite protein gene expression during the sporogonic stages of plasmodium yoelii yoelii and p. y. niger ... | 2003 | 12760638 |
| high diversity and rapid changeover of expressed var genes during the acute phase of plasmodium falciparum infections in human volunteers. | plasmodium falciparum erythrocyte membrane protein 1 (pfemp1) proteins expressed on the surface of p. falciparum-infected erythrocytes undergo antigenic variation by switching the gene expressed within a repertoire of approximately 50 var genes per haploid genome. the switching of pfemp1 plays an important role in the survival and pathogenesis of the parasite. to understand how a parasite switches its var gene expression in human infections, we investigated the composition and change of var gene ... | 2002 | 12142467 |
| sulfadoxine-pyrimethamine resistance in the rodent malaria parasite plasmodium chabaudi. | we have studied resistance to sulfadoxine-pyrimethamine (s/p) in the rodent malaria parasite plasmodium chabaudi. a stable s/p-resistant mutant, as(50s/p), was selected by drug treatment of a clone, as(pyr), already resistant to pyrimethamine. the sequences of the p. chabaudi dhfr and dhps genes were obtained and found to be identical in as(50s/p) and as(pyr), showing that resistance to s/p in as(50s/p) was not due to additional mutations in either gene. as(50s/p) was crossed with a drug-sensiti ... | 2002 | 12121922 |
| plasmodium vivax blood-stage dynamics. | we examine the dynamics of parasitemia and gametocytemia reflected in the preintervention charts of 221 malaria-naive u.s. neurosyphilis patients infected with the st. elizabeth strain of plasmodium vivax, for malariatherapy, focusing on the 109 charts for which 15 or more days of patency preceded intervention and daily records encompassed an average 98% of the duration of each infection. our approximations of merogony cycles (via "local peaks" in parasitemia) seldom fit patterns that correspond ... | 2002 | 12099421 |
| [effect of dihydroquinghaosu on the development of plasmodium yoelii yoelii in anopheles stephensi]. | to observe the effect of dihydro qinghaosu (dqhs) on the development of plasmodium yoelii yoelii in anopheles stephensi and to explore the possibility of whether dqhs has preventive effect against malaria. | 1998 | 12078286 |
| persistence of protective immunity to malaria induced by dna priming and poxvirus boosting: characterization of effector and memory cd8(+)-t-cell populations. | the persistence of immunity to malaria induced in mice by a heterologous dna priming and poxvirus boosting regimen was characterized. mice were immunized by priming with dna vaccine plasmids encoding the plasmodium yoelii circumsporozoite protein (pycsp) and murine granulocyte-macrophage colony-stimulating factor and boosting with recombinant vaccinia encoding pycsp. balb/c mice immunized with either high-dose (100 microg of p pycsp plus 30 microg of pgm-csf) or low-dose (1 microg of p pycsp plu ... | 2002 | 12065488 |
| a theoretical approach to predicting the success of genetic manipulation of malaria mosquitoes in malaria control. | mosquitoes that have been genetically modified to better encapsulate the malaria parasite plasmodium falciparum are being considered as a possible tool in the control of malaria. hopes for this have been raised with the identification of genes involved in the encapsulation response and with advances in the tools required to transform mosquitoes. however, we have only very little understanding of the conditions that would allow such genes to spread in natural populations. | 2002 | 12057019 |
| implications of time bomb model of ookinete invasion of midgut cells. | in this review, we describe the experimental observations that led us to propose the time bomb model of ookinete midgut invasion and discuss potential implications of this model when considering malaria transmission-blocking strategies aimed at arresting parasite development within midgut cells. a detailed analysis of the molecular interactions between anopheles stephensi midgut epithelial cells and plasmodium berghei parasites, as they migrate through midgut cells, revealed that ookinetes induc ... | 2002 | 12225921 |
| cdna cloning, functional expression and characterization of kynurenine 3-hydroxylase of anopheles stephensi (diptera: culicidae). | kynurenine 3-hydroxylase (k3h) is a nadph-dependent flavin monooxygenase involved in the tryptophan pathway. xanthurenic acid (xa) is a metabolite of this pathway and has recently been identified as a gamete activating factor (gaf) of the malarial parasite. we cloned k3h cdna from anopheles stephensi (ask3h), because anopheline mosquitoes are a vector of the human malaria parasite, plasmodium falciparum and the catalytic function of ask3h in xa production. recombinant ask3h protein was expressed ... | 2002 | 12230548 |
| cloning and characterization of an insecticidal crystal protein gene from bacillus thuringiensis subspecies kenyae. | a sporulating culture of bacillus thuringiensis subsp. kenyae strain hd549 is toxic to larvae of lepidopteran insect species such as spodoptera litura, helicoverpa armigera and phthorimaea operculella, and a dipteran insect, culex fatigans. a 1.9-kb dna fragment, pcr-amplified from hd549 using cryii-gene-specific primers, was cloned and expressed in e. coli. the recombinant protein produced 92% mortality in first-instar larvae of spodoptera litura and 86% inhibition of adult emergence in phthori ... | 2002 | 12357073 |
| merozoite surface protein 1-specific immune response is protective against exoerythrocytic forms of plasmodium yoelii. | one of the difficulties in developing an effective malaria vaccine is the antigenic change of the parasite during the life cycle. it is desirable that vaccine-induced protective immunity be effective at different stages of parasite development. merozoite surface protein 1 (msp1) is a candidate vaccine antigen against blood-stage malaria, but it is also expressed in the exoerythrocytic forms. it was not known, however, whether the anti-msp1 immune response is effective against the liver-stage mal ... | 2002 | 12379684 |
| the histone-like c-terminal extension in ribosomal protein s6 in aedes and anopheles mosquitoes is encoded within the distal portion of exon 3. | in eukaryotic cells, ribosomal protein s6 (rps6) is the major phosphorylated protein on the small ribosomal subunit. in the mosquitoes aedes aegypti and aedes albopictus, the cdna encoding rps6 contains 300 additional nucleotides, relative to the drosophila homolog. the additional sequence encodes a 100-amino acid, lysine-rich c-terminal extension of the rps6 protein with 42-49% identity to histone h1 proteins from the chicken and other multicellular organisms. using mass spectrometry we now sho ... | 2003 | 12915181 |
| disseminated candidiasis and hepatic malarial infection in mannose-binding-lectin-a-deficient mice. | to examine the physiological functions of mannose-binding lectin a (mbl-a), we generated mice that were deficient in mbl-a and examined their susceptibilities to the microbial pathogens candida albicans and plasmodium yoelii, an accepted experimental malaria model in mouse. we found no differences in the survival rates and fungal burdens of wild-type and mbl-a(-/-) mice with disseminated c. albicans infection. the two mouse strains were also similar in their abilities to resist hepatic accumulat ... | 2002 | 12417723 |
| 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, ... | 2002 | 12479543 |
| insecticide-treated plastic tarpaulins for control of malaria vectors in refugee camps. | spraying of canvas tents with residual pyrethroid insecticide is an established method of malaria vector control in tented refugee camps. in recent years, plastic sheeting (polythene tarpaulins) has replaced canvas as the utilitarian shelter material for displaced populations in complex emergencies. advances in technology enable polythene sheeting to be impregnated with pyrethroid during manufacture. the efficacy of such material against mosquitoes when erected as shelters under typical refugee ... | 2002 | 12510893 |
| role of wastewater irrigation in mosquito breeding in south punjab, pakistan. | mosquito breeding within the wastewater irrigation system around the town of haroonabad in the southern punjab, pakistan, was studied from july to september 2000 as part of a wider study of the costs and benefits of wastewater use in agriculture. the objective of this study was to assess the vector-borne human disease risks associated with mosquito species utilizing wastewater for breeding. mosquito larvae were collected on a fortnightly basis from components of the wastewater disposal system an ... | 2003 | 12971517 |
| [experimental transmission of myxomatosis into rabbits by anopheles maculipennis atroparvus and anopheles stephensi]. | | 1954 | 13229028 |
| comparative experimental infections in anopheles fluviatilis and anopheles stephensi (type) with plasmodium falciparum welch, 1897. | | 1955 | 13262833 |
| transmission of plasmodium knowlesi by anopheles stephensi. | | 1957 | 13467998 |
| partial inhibitory effect of plistophora culicis on the sporogonic cycle of plasmodium cynomolgi in anopheles stephensi. | | 1958 | 13504228 |
| nitric oxide contributes to induction of innate immune responses to gram-negative bacteria in drosophila. | studies in mammals uncovered important signaling roles of nitric oxide (no), and contributions to innate immunity. suggestions of conservation led us to explore the involvement of no in drosophila innate immunity. inhibition of nitric oxide synthase (nos) increased larval sensitivity to gram-negative bacterial infection, and abrogated induction of the antimicrobial peptide diptericin. nos was up-regulated after infection. antimicrobial peptide reporters revealed that no triggered an immune respo ... | 2003 | 12514104 |
| [enrichment and screening of up-regulated genes of the mosquito anopheles stephensi in response to malaria parasite]. | to isolate and identify genes related to malaria parasite infection in vector mosquito, and to explore the mechanisms. | 2001 | 12572060 |
| infection of malaria (anopheles gambiae s.s.) and filariasis (culex quinquefasciatus) vectors with the entomopathogenic fungus metarhizium anisopliae. | current intra-domiciliary vector control depends on the application of residual insecticides and/or repellents. although biological control agents have been developed against aquatic mosquito stages, none are available for adults. following successful use of an entomopathogenic fungus against tsetse flies (diptera: glossinidae) we investigated the potency of this fungus as a biological control agent for adult malaria and filariasis vector mosquitoes. | 2003 | 14565851 |
| ovary specific immune response during plasmodium yoelii yoelii infection in malaria vector anopheles stephensi (diptera:insecta). | innate immune related polypeptides expression during three gonotrophic cycles in the ovaries of major disease vector mosquito a. stephensi has been analyzed following infection by malaria parasite, p. yoelii yoelii. seventeen polypeptides were induced in the ovaries of various stages due to parasitic infection. most of proteins were induced systemically during early stages of infection suggesting the possibility of immune related signalling process. the reduction in the quantity of protein conte ... | 2002 | 12622212 |
| anopheline vectors and malaria transmission in eastern afghanistan. | anopheline vectors and malaria transmission were studied in 2 river-irrigated, rice-growing districts of eastern afghanistan from may 1995 to december 1996. clinical malaria was monitored in 12 rural villages (population 14,538) by passive case detection at local clinics. adult mosquitoes were collected by space-spraying of living quarters and stables and by cattle bait catches. mosquito head-thoraces (17,255 specimens) were tested for plasmodium falciparum and p. vivax circumsporozoite protein ... | 2002 | 12625136 |
| p elements are found in the genomes of nematoceran insects of the genus anopheles. | we report the identification of genomic sequences in various anopheline mosquitoes (family culicidae: suborder nematocera: order diptera) showing homology to the class ii, short inverted-terminal-repeat (itr) transposable element p from drosophila melanogaster (family drosophilidae; suborder brachycera: order diptera). anopheles gambiae appears to have at least six distinct p elements. other anopheline species, including four additional members of the an. gambiae species complex (an. arabiensis, ... | 2003 | 12650686 |
| transformation of sporozoites into early exoerythrocytic malaria parasites does not require host cells. | malaria parasite species that infect mammals, including humans, must first take up residence in hepatic host cells as exoerythrocytic forms (eef) before initiating infection of red blood cells that leads to malaria disease. despite the importance of hepatic stages for immunity against malaria, little is known about their biology and antigenic composition. here, we show that sporozoites, the parasites' transmission stage that resides in the mosquito vector salivary glands, can transform into earl ... | 2003 | 12707302 |
| comparative analysis of dna vectors at mediating rnai in anopheles mosquito cells and larvae. | heritable rna interference (rnai) mediated by transgenes exhibiting dyad symmetry represents an important tool to study the function of genes expressed at late developmental stages. in this study, we determined whether the transcriptional machinery of anopheles mosquitoes is capable of directing suppression of gene expression from dna constructs designed to transcribe double-stranded rna (dsrna) as extended hairpin-loop rnas. a series of dna vectors containing sense and antisense regions of the ... | 2003 | 12728003 |
| mammalian transforming growth factor beta1 activated after ingestion by anopheles stephensi modulates mosquito immunity. | during the process of bloodfeeding by anopheles stephensi, mammalian latent transforming growth factor beta1 (tgf-beta1) is ingested and activated rapidly in the mosquito midgut. activation may involve heme and nitric oxide (no), agents released in the midgut during blood digestion and catalysis of l-arginine oxidation by a. stephensi no synthase (asnos). active tgf-beta1 persists in the mosquito midgut to extended times postingestion and is recognized by mosquito cells as a cytokine. in a manne ... | 2003 | 12761076 |
| induction of plasmodium falciparum transmission-blocking antibodies in nonhuman primates by a combination of dna and protein immunizations. | malaria transmission-blocking vaccination can effectively reduce and/or eliminate transmission of parasites from the human host to the mosquito vector. the immunity achieved by inducing an antibody response to surface antigens of male and female gametes and parasite stages in the mosquito. our laboratory has developed dna vaccine constructs, based on pfs25 (a plasmodium falciparum surface protein of 25 kda), that induce a transmission-blocking immune response in mice (c. a. lobo, r. dhar, and n. ... | 2004 | 14688103 |