| larvicidal toxicity of japanese bacillus thuringiensis against the mosquito anopheles stephensi. | japanese isolates of bacillus thuringiensis were screened for larvicidal activity against the mosquito anopheles stephensi, the urban malaria vector of the indian subcontinent. among more than 30 strains identified, larvicidal activity causing > 80% mortality in 72 h was demonstrated for 41/1449 (2.8%) isolates. the majority of strains and isolates (97.2%) exhibited little or no larvicidal activity. anopheles-active strains belonged to more than 12 h serotypes, especially h3ade (serovar fukuokae ... | 1998 | 9513945 |
| plasmodium berghei: infectivity of mice to anopheles stephensi mosquitoes. | the infectivity of p. berghei-infected to mice to mosquitoes declines rapidly 2 to 5 days after blood inoculation, in spite of rising numbers of gametocytes in the blood. this pattern is typical of many malaria infections and various factors, particularly specific and nonspecific immune responses, have previously been implicated in the decline. here we report that (1) simple physiological changes in the mouse blood, namely, falling ph and bicarbonate levels induced by high parasitaemias, are res ... | 1996 | 8948326 |
| dosage differential effects of permethrin impregnated into bednets on pyrethroid resistant and susceptible genotypes of the mosquito anopheles stephensi. | effects of bednets impregnated with permethrin 200 mg and 500 mg/m2 on pyrethroid resistant and susceptible strains of anopheles stephensi and their f1 hybrid progeny were studied, using free-flying female mosquitoes of these three genotypes, in a room with a human subject under a polyester net, having one of his arms in contact with the treated netting. unexpectedly an apparently higher feeding rate, but lower knockdown and mortality rates, of mosquitoes were obtained for each of the three geno ... | 1997 | 9430117 |
| severe and complicated malaria in bikaner (rajasthan), western india. | severe and complicated malaria is an important cause of mortality in plasmodium falciparum infection. we describe in this study the details of 532 cases of such syndromes admitted to hospital during an outbreak of malaria between september-december 1994. increase in the annual rain fall, collection of water around indra gandhi canal, forestation of shrubs around it and migration of labor, adaptation of anopheles stephensi to desert climate and favorable breeding of an. culicifacies in the areas ... | 1997 | 9444003 |
| two-site immunoradiometric assay (irma): detection, efficiency, and procedural modifications. | a 2-site immunoradiometric assay (irma) has been done using anopheles stephensi fed on plasmodium vivax blood through parafilm to ascertain at what time in the sporogonic cycle circumsporozoite (cs) antigen can be detected, and to detect cs antigen in mosquitoes squashed on filter paper (fp) and cellulose acetate membrane (cam). the cs antigen was detectable only in mature oocysts, a day prior to sporozoite liberation, and in salivary gland sporozoites. dissected sporozoites adsorbed on fp/cam a ... | 1994 | 8965070 |
| insecticidal activity of bacillus laterosporus. | the bacillus laterosporus strains 921 and 615 were shown to have toxicity for larvae of the mosquitoes aedes aegypti, anopheles stephensi, and culex pipiens. the larvicidal activity of b. laterosporus was associated with spores and crystalline inclusions. purified b. laterosporus 615 crystals were highly toxic for aedes aegypti and anopheles stephensi. | 1998 | 9647857 |
| chitinases are a multi-gene family in aedes, anopheles and drosophila. | degenerate primers were used to amplify by the polymerase chain reaction (pcr) dna fragments from the chitinase genes of five insect species: aedes aegypti, anopheles freeborni, anopheles gambiae, anopheles stephensi and drosophila melanogaster. as many as four different products were found for each species; each deduced protein sequence having greatest homology to chitinase sequences from other species of insects and the crustacean, penaeus japonicus. the four pcr products of a. aegypti hybridi ... | 1998 | 9662472 |
| characterization of aedes communis, aedes aegypti and anopheles stephensi mosquito saliva antigens by immunoblotting. | mosquito bites cause immediate wheals and delayed bite papules in sensitized subjects having saliva-specific ige and igg4 antibodies. at present, mosquito saliva antigens are not well characterized. | 1997 | 9030098 |
| characterization of mosquito larvicidal parasporal inclusions of a bacillus thuringiensis serovar higo strain. | the parasporal inclusion proteins of the type strain of bacillus thuringiensis serovar higo (h44), that have moderate mosquitocidal activity, were characterized. the purified parasporal inclusions, spherical in shape, were examined for activity against the two mosquito species, culex pipiens molestus and anopheles stephensi and the moth-fly, telmatoscopus albipunctatus. the lc50 values of the inclusion for the two mosquitoes were 3.41 and 0.15 microgram.ml-1, respectively. no mortality was shown ... | 1998 | 9674143 |
| insecticidal susceptibility status of anopheles stephensi (liston) in selected areas of calcutta (west bengal). | susceptibility tests were carried out with insecticides like organochlorine organophosphorus and synthetic pyrethroids using the who test kits against anopheles stephensi larvae and adults, collected from malaria endemic wards of calcutta in december, 1995 and january, 1996 anopheles stephensi adults were found resistant to ddt, propoxure, malathion but susceptible to fenthion and deltamethrin. | 1996 | 9119432 |
| a novel class of mosquitocidal delta-endotoxin, cry19b, encoded by a bacillus thuringiensis serovar higo gene. | partially digested hincii fragments of dna from a mosquitocidal strain of bacillus thuringiensis serovar higo were cloned into pbluescript ii sk(+) and propagated in escherichia coli. recombinant cells were screened immunologically for the production of parasporal inclusion antigens. one e. coli clone harboring a recombinant plasmid exhibited larvicidal activity to culex pipiens molestus, but not to anopheles stephensi. hybridization experiments revealed that the gene of the toxin protein is loc ... | 1998 | 9704107 |
| domestic breeding sources and their contribution in anopheles stephensi breeding in dindigul, tamil nadu. | longitudinal study taken up for one year in 10 different types of breeding habitats in dindigul town, tamil nadu, revealed that out of 51,785 habitats 225 (0.43%) were found positive for anopheles stephensi immatures. the overall positivity varied between 0.03 to 1.31% with peak density during july. the observed habitat-wise positivity was overhead tanks 0-7.07%; wells 0-1.69%; under ground tanks 0-2.26%; tappits 0-2.36%; outside tanks (permanent) 0-2.42%; outside tanks (temporary) 0-0.39%; insi ... | 1996 | 9125833 |
| bacillus thuringiensis and its pesticidal crystal proteins. | during the past decade the pesticidal bacterium bacillus thuringiensis has been the subject of intensive research. these efforts have yielded considerable data about the complex relationships between the structure, mechanism of action, and genetics of the organism's pesticidal crystal proteins, and a coherent picture of these relationships is beginning to emerge. other studies have focused on the ecological role of the b. thuringiensis crystal proteins, their performance in agricultural and othe ... | 1998 | 9729609 |
| genetics of refractoriness to plasmodium falciparum in the mosquito anopheles stephensi. | we previously selected a line of the malaria vector mosquito anopheles stephensi refractory (resistant) to the human malaria parasite plasmodium falciparum, using in vitro infections with p. falciparum gametocytes. this report presents data on the genetic background of refractoriness. the results of f1-crosses and backcrosses show that refractoriness to p. falciparum in our a. stephensi line is autosomal and semi-dominant to susceptibility. the expression of refractoriness is apparently affected ... | 1998 | 9737603 |
| variable cross-resistance to cry11b from bacillus thuringiensis subsp. jegathesan in culex quinquefasciatus (diptera: culicidae) resistant to single or multiple toxins of bacillus thuringiensis subsp. israelensis. | a novel mosquitocidal bacterium, bacillus thuringiensis subsp. jegathesan, and one of its toxins, cry11b, in a recombinant b. thuringiensis strain were evaluated for cross-resistance with strains of the mosquito culex quinquefasciatus that are resistant to single and multiple toxins of bacillus thuringiensis subsp. israelensis. the levels of cross-resistance (resistance ratios [rr]) at concentrations which caused 95% mortality (lc95) between b. thuringiensis subsp. jegathesan and the different b ... | 1998 | 9797262 |
| development of a natural model of cutaneous leishmaniasis: powerful effects of vector saliva and saliva preexposure on the long-term outcome of leishmania major infection in the mouse ear dermis. | we have developed a model of cutaneous leishmaniasis due to leishmania major that seeks to mimic the natural conditions of infection. 1,000 metacyclic promastigotes were coinoculated with a salivary gland sonicate (sgs) obtained from a natural vector, phlebotomus papatasii, into the ear dermis of naive mice or of mice preexposed to sgs. the studies reveal a dramatic exacerbating effect of sgs on lesion development in the dermal site, and a complete abrogation of this effect in mice preexposed to ... | 1998 | 9815271 |
| the amino acid composition of anopheles stephensi (diptera: culicidae) infected with nosema algerae (microsporida: nosematidae) | the amino acid composition of larvae, pupae, and adult mosquitoes of anopheles stephensi infected with nosema algerae and noninfected insects was analyzed using an amino acid analyzer. the increase and decrease in the concentration of single amino acids during the development of the microsporidium were compared with the spread of meronts, sporonts, and spores within the host. the appearance of meronts and sporonts coincided mainly with an increase in the concentration of alanine and histidine. t ... | 1998 | 9446736 |
| similarity in moth-fly specific larvicidal activity between two serologically unrelated bacillus thuringiensis strains. | parasporal inclusions of a bacillus thuringiensis isolate designated 92-ku-105-9 (h14/19) exhibited unusual larvicidal activity, specific for the moth-fly, telmatoscopus albipunctatus (diptera: psychodidae), similar to that of a previously reported b. thuringiensis serovar leesis (h33) strain. the lc50 value of the purified inclusions was 4.92 micrograms ml-1 for the moth-fly larvae, while no mortality was shown in the mosquitoes culex pipiens molestus and anopheles stephensi, at protein concent ... | 1998 | 9868764 |
| lethal effect of rickettsia rickettsii on its tick vector (dermacentor andersoni). | rickettsia rickettsii, the causative agent of rocky mountain spotted fever, was lethal for the majority of experimentally and transovarially infected rocky mountain wood ticks (dermacentor andersoni). overall, 94.1% of nymphs infected as larvae by feeding on rickettsemic guinea pigs died during the molt into adults and 88. 3% of adult female ticks infected as nymphs died prior to feeding. in contrast, only 2.8% of uninfected larvae failed to develop into adults over two generations. infected fem ... | 1999 | 9925615 |
| mixed-species plasmodium infections of humans. | we analyzed point-prevalence data from 35 recent studies of human populations in which plasmodium falciparum and one other plasmodium species were the reported causes of malaria infections. for the p. falciparum-plasmodium vivax pair, higher overall prevalence in a human population is associated with fewer mixed-species infections than expected on the basis of the product of individual species prevalences. this is not true for p. falciparum-plasmodium malariae. | 1997 | 9267397 |
| natural inhibitors of cholinesterases: implications for adverse drug reactions. | acetylcholinesterase and butyrylcholinesterase are two closely related enzymes important in the metabolism of acetylcholine and anaesthetic drugs, including succinylcholine, mivacurium, and cocaine. the solanaceous glycoalkaloids (sgas) are naturally occurring steroids in potatoes and related plants that inhibit both acetylcholinesterase and butyrylcholinesterase. there are many clinical examples of direct sga toxicity due to cholinesterase inhibition. the aim of this study was to review the hyp ... | 1997 | 9161749 |
| studies on a primaquine-tolerant strain of plasmodium vivax from brazil in aotus and saimiri monkeys. | a nonimmune american acquired an infection of plasmodium vivax type 1 malaria in brazil in 1994. after returning to the u.s.a., he had a primary attack followed by 3 relapses. the primary attack and first 2 relapses were treated with a standard regimen of chloroquine, followed by 14 days of primaquine (15 mg/day). following the third relapse, the primaquine treatment was extended to 28 days. no further relapses occurred. the lack of response to primaquine by this strain may recommend it as a sui ... | 1997 | 9267419 |
| induced immunity against the mosquito anopheles stephensi: reactivity characteristics of immune sera. | this study shows the progression of immune responses in mice during five sequential immunizations with anopheles stephensi mosquito extracts, characterized by elisa, western blot and immunohistochemistry. when exposed repeatedly to mosquito bites, control mice developed antibodies which reached titres of 1:10(5), reacted weakly in western blot analysis and were localized to the salivary glands. mice immunized with mosquito head plus salivary glands, midgut, ovary, fat body, midgut microvilli (mv ... | 1999 | 10194750 |
| antagonism between cry1ac1 and cyt1a1 toxins of bacillus thuringiensis | most strains of the insecticidal bacterium bacillus thuringiensis have a combination of different protoxins in their parasporal crystals. some of the combinations clearly interact synergistically, like the toxins present in b. thuringiensis subsp. israelensis. in this paper we describe a novel joint activity of toxins from different strains of b. thuringiensis. in vitro bioassays in which we used pure, trypsin-activated cry1ac1 proteins from b. thuringiensis subsp. kurstaki, cyt1a1 from b. thuri ... | 1999 | 10223999 |
| isolation of a substance from the mosquito that activates plasmodium fertilization. | we have isolated a small, heat stabile, hydrophilic molecule from the gut lumen of unfed, female anopheles stephensi that is a potent inducer of gametogenesis in plasmodium falciparum and p. gallinaceum at a hydrogen ion concentration, ph 7.4, that normally suppresses activation. this gamete activation factor (gaf) was purified using reverse phase high performance liquid chromatography and determined to have a major ion m/z of 206.1 by low resolution electrospray mass spectrometry. the molecule, ... | 1997 | 9274874 |
| green fluorescent protein as a marker in plasmodium berghei transformation. | we present a new marker that confers both resistance to pyrimethamine and green fluorescent protein-based fluorescence on the malarial parasite plasmodium berghei. a single copy of the cassette integrated into the genome is sufficient to direct fluorescence in parasites throughout the life cycle, in both its mosquito and vertebrate hosts. erythrocyte stages of the parasite that express the marker can be sorted from control parasites by flow cytometry. pyrimethamine pressure is not necessary for ... | 1999 | 10225926 |
| the roles of temperature, ph and mosquito factors as triggers of male and female gametogenesis of plasmodium berghei in vitro. | developmentally arrested malarial gametocytes undergo gamete formation in the mosquito midgut immediately after ingestion of the infected bloodmeal. in the rodent malaria parasite plasmodium berghei male gametogenesis (exflagellation) can be induced in vitro by a temperature decrease (from 39 degrees c in the vertebrate host to 20 degrees c) and a concomitant ph increase (from 7.3 in mouse blood to 8.0). we report the presence of additional gametocyte activating factor(s) (gaf) present in anophe ... | 1997 | 9280891 |
| access of antibody or trypsin to an integral outer membrane protein (p66) of borrelia burgdorferi is hindered by osp lipoproteins. | the outer membrane of borrelia burgdorferi, the lyme disease agent, contains lipoproteins anchored by their lipid moieties and integral proteins with membrane-spanning regions. we used the techniques of in situ proteolysis, immunofluorescence, in vitro growth inhibition, and cross-linking with formaldehyde to characterize topological relationships between p66, an integral membrane protein, and selected osp lipoproteins of b. burgdorferi. protease treatment of intact spirochetes cleaved p66 and o ... | 1999 | 10338494 |
| binding kinetics of bacillus sphaericus binary toxin to midgut brush-border membranes of anopheles and culex sp. mosquito larvae. | direct-binding assays and homologous-competition assays were used to identify specific binding between the radiolabelled toxin of bacillus sphaericus and brush-border membrane fractions (bbmf) from anopheles gambiae and anopheles stephensi, obtained from whole larvae preparations. in both species, the toxin bound to a single class of receptors. bbmf of a. gambiae had the highest binding affinity for the toxin of the species tested, with a dissociation constant (kd) of 30 +/- 15 nm and a maximum ... | 1997 | 9288894 |
| the effects of infection with plasmodium yoelii nigeriensis on the reproductive fitness of anopheles stephensi. | infection with the rodent malarial parasite plasmodium yoelii nigeriensis caused a significant reduction in the reproductive fitness (number of eggs produced and proportion of eggs hatched) of two different generations of anopheles stephensi. overall fertility (number of larvae produced) was reduced by 38.3% in the generation containing smaller mosquitoes (with a wing length of 3.2 +/- 0.1 mm) with relatively larger parasite burdens, and by 48.81% in the generation containing larger mosquitoes ( ... | 1997 | 9290843 |
| urban malaria vector biology. | one of the main reasons for the set-back in the urban malaria control programme is the peculiar biobehaviour of the principal urban malaria vector anopheles stephensi. certain relevant facts such as incrimination as the vector of malaria, sibling or biological species, resting habitat, manlanding behaviour, seasonal prevalence, blood meal analysis, longevity, parity status, daily survival and mortality rates of adults, breeding habitats and vertical distribution of larvae of an. stephensi have b ... | 1997 | 9291684 |
| anopheles stephensi salivary glands bear receptors for region i of the circumsporozoite protein of plasmodium falciparum. | in the mosquito, plasmodium sporozoites rupture from oocysts found on the midgut wall, circulate in the hemolymph and invade salivary glands where they wait to be injected into a vertebrate host during a bloodmeal. the mechanisms by which sporozoites specifically attach to and invade salivary glands are not known but evidence suggests that it is a receptor-mediated process. here we show that the major surface protein of sporozoites, the circumsporozoite protein (cs), binds preferentially to sali ... | 1997 | 9497030 |
| effects of plasmodium yoelii nigeriensis infection on anopheles stephensi egg development and resorption. | it has been shown previously that infection with plasmodium yoelii nigeriensis reduces the number of eggs produced by female anopheles stephensi. here we examine the mechanism underlying fecundity reduction. ovaries from infected and uninfected (control) female mosquitoes were examined 12, 24 or 36 h after blood-feeding during the first gonotrophic cycle (replicated) or the second gonotrophic cycle (unreplicated). follicular development was assessed according to christophers' stages and the prop ... | 1997 | 9330258 |
| two antigens on zygotes and ookinetes of plasmodium yoelii and plasmodium berghei that are distinct targets of transmission-blocking immunity. | we have developed transmission-blocking monoclonal antibodies (mabs) against plasmodium yoelii 21-kda (pys21) and 28-kda (pys25) ookinete surface proteins. these mabs block infectivity of p. yoelii to anopheles stephensi. one mab, 14, cross-reacted by western blotting with a 28-kda surface protein (pbs25) of p. berghei ookinetes and blocked oocyst development, as assayed by direct mosquito feeds on passively immunized p. berghei-infected mice. in total, we have identified two ookinete surface pr ... | 1997 | 9169761 |
| infectivity of plasmodium berghei sporozoites delivered by intravenous inoculation versus mosquito bite: implications for sporozoite vaccine trials. | plasmodium berghei sporozoites delivered by mosquito bite were more infectious to outbred cd-1 mice than were sporozoites delivered by intravenous inoculation. the route of challenge also affected vaccine efficacy. in view of these findings and the fact that mosquito bites are the natural mode of sporozoite delivery, infectious mosquito bites should be considered the challenge protocol of choice for sporozoite vaccine efficacy trials. | 1999 | 10417207 |
| delayed migration of plasmodium sporozoites from the mosquito bite site to the blood. | studies were done on delivery of plasmodium yoelii sporozoites by anopheles stephensi into the skin of balb/c mice. when infected mosquitoes fed on a portion of the ear, 81% of these positive control mice developed parasitemia. when the fed-upon site was excised immediately or 5 min postfeeding, a highly significant, smaller percentage of these experimental mice developed parasitemia. when the delay in removal of mosquito-bitten tissue was extended to 15 min, no significant difference was found ... | 1997 | 9347958 |
| improvement of bacillus sphaericus toxicity against dipteran larvae by integration, via homologous recombination, of the cry11a toxin gene from bacillus thuringiensis subsp. israelensis. | integrative plasmids were constructed to enable integration of foreign dna into the chromosome of bacillus sphaericus 2297 by in vivo recombination. integration of the apha3 kanamycin resistance gene by a two-step procedure demonstrated that this strategy was applicable with antibiotic resistance selection. hybridization experiments evidenced two copies of the operon encoding the binary toxin from b. sphaericus in the recipient strain. the bacillus thuringiensis subsp. israelensis cry11aal gene ... | 1997 | 9361428 |
| facilitation of rift valley fever virus transmission by plasmodium berghei sporozoites in anopheles stephensi mosquitoes. | certain mosquito species are susceptible to viral infection but cannot transmit the virus due to a salivary gland barrier. we hypothesized that such species could transmit virus if the mosquito were infected with both virus and malaria parasites. malaria sporozoites disrupt the integrity of mosquito salivary glands and, in so doing, may destroy salivary gland barriers to viral transmission. to examine this postulate, the model system of rift valley fever (rvf) virus and a rodent parasite, plasmo ... | 1996 | 8916797 |
| analysis of molecular forms and pharmacological properties of acetylcholinesterase in several mosquito species. | two acetylcholinesterases (ache1 and ache2) have recently been characterized in the common mosquito culex pipiens. this situation appeared to be an exception among insects, where only one acetylcholinesterase gene had previously been repeatedly reported. in the present study, acetylcholinesterase was studied in five mosquito species: aedes aegypti, anopheles gambiae, anopheles stephensi, culiseta longeareolata and culex hortensis, in order to test whether or not two different acetylcholinesteras ... | 1997 | 9185166 |
| genetic structure of plasmodium vivax isolates in india. | variations in the allelic composition of glucose phosphate isomerase (gpi), nadp-dependent glutamate dehydrogenase (gdh) and adenosine deaminase (ada) enzyme systems of plasmodium vivax were observed in isolates of indian origin in 1985-1993. no significant difference was observed in allelic frequencies in different years. the data indicated random distribution of gpi, gdh and ada alleles among the isolates, suggesting that loci for these enzymes were not linked. a high proportion of the isolate ... | 1997 | 9196779 |
| germination, growth, and sporulation of bacillus thuringiensis subsp. israelensis in excreted food vacuoles of the protozoan tetrahymena pyriformis. | spores of bacillus thuringiensis subsp. israelensis and their toxic crystals are bioencapsulated in the protozoan tetrahymena pyriformis, in which the toxin remains stable. each t. pyriformis cell concentrates the spores and crystals in its food vacuoles, thus delivering them to mosquito larvae, which rapidly die. vacuoles containing undigested material are later excreted from the cells. the fate of spores and toxin inside the food vacuoles was determined at various times after excretion by phas ... | 1998 | 9572947 |
| the mosquito anopheles stephensi limits malaria parasite development with inducible synthesis of nitric oxide. | we have discovered that the mosquito anopheles stephensi, a natural vector of human malaria, limits parasite development with inducible synthesis of nitric oxide (no). elevated expression of a. stephensi no synthase (nos), which is highly homologous to characterized nos genes, was detected in the midgut and carcass soon after invasion of the midgut by plasmodium. early induction is likely primed by bacterial growth in the blood meal. later increases in a. stephensi nos expression and enzyme acti ... | 1998 | 9576947 |
| adaptation of a strain of plasmodium vivax from mauritania to new world monkeys and anopheline mosquitoes. | a strain of plasmodium vivax from mauritania was adapted to develop in aotus lemurinus griseimembra, aotus nancymai, saimiri boliviensis, and hybrid aotus monkeys. infections were induced via the inoculation of sporozoites dissected from the salivary glands of anopheles gambiae, anopheles freeborni, and anopheles stephensi mosquitoes or the intravenous passage of infected erythrocytes. infections in 3 a. lemurinus griseimembra monkeys readily infected mosquitoes. four lines of the mauritania par ... | 1998 | 9645868 |
| heat shock response during development of the malaria vector anopheles stephensi (culicidae: diptera). | the pattern of synthesis of heat shock proteins (hsp) and thermotolerance to elevated temperatures during the development of the malaria vector anopheles stephensi normally reared at 28 +/- 2 degrees c was studied using sds-page. in total twelve heat shock proteins (i.e. 31, 33, 38, 43, 44, 51, 57, 62, 69, 71, 113 and 121 kd were induced by heat shock during various stages of development. eight polypeptides (hsp during one or other of the instars) appeared during normal development of the adult, ... | 1999 | 10581708 |
| transgenic expression of a mosquito-stage malarial protein, pbs21, in blood stages of transformed plasmodium berghei and induction of an immune response upon infection. | pbs21 is a surface protein of the ookinete of plasmodium berghei, which can induce a potent transmission-blocking immune response. pbs21 is normally expressed only by parasite stages in the mosquito, i.e., female gametes/zygotes, ookinetes, and oocysts. however, the pbs21 gene is transcribed in female gametocytes which circulate in the bloodstream of the host, where translation of the resulting mrna is totally repressed. episomal transfection has been used to investigate whether expression of pb ... | 1998 | 9673276 |
| purification and characterization of a thrombin inhibitor from the salivary glands of a malarial vector mosquito, anopheles stephensi. | a coagulation inhibitor was identified and isolated from the salivary glands of a malarial vector mosquito, anopheles stephensi. the salivary gland extract prolonged activated partial thromboplastin time (aptt) and prothrombin time (pt) in assays with human plasma. the inhibition assay of the factors in the coagulation cascade by using synthetic chromogenic substrates showed that the anticoagulant in the mosquito salivary glands is a thrombin inhibitor, but not an inhibitor of factor xa. the ant ... | 1998 | 9685655 |
| two-dimensional gel analysis of midgut proteins of anopheles stephensi lines with different susceptibility to plasmodium falciparum infection. | little is known about the composition of the mosquito midgut which plays a central role in the development and subsequent transmission of malaria parasites. as a first step towards the characterization of mosquito midgut molecules involved in the transmission of malaria parasites, we analysed two-dimensional gel electrophoresis patterns of the midgut proteins of sugar-fed and blood-fed anopheles stephensi lines of different susceptibility to p. falciparum infection. two lines fully susceptible a ... | 1998 | 9723875 |
| effect of plasmodium yoelii nigeriensis (haemosporidia: plasmodiidae) on anopheles stephensi (diptera: culicidae) vitellogenesis. | our previous studies demonstrated a significant reduction in the egg production and survival of anopeles stephensi liston infected with plasmodium yoelii nigeriensis killick-kendrick. we investigated the physiological mechanism underlying the malaria-induced curtailment of reproductive fitness. polyclonal antibodies were raised against an. stephensi vitellin (vn) and used in an enzyme immunoassay to quantify ovarian vn and hemolymph vitellogenin (vg) at 8, 12, 16, 20, 24, and 48 h postblood feed ... | 1998 | 9835686 |
| immunogenicity and in vitro protective efficacy of a recombinant multistage plasmodium falciparum candidate vaccine. | compared with a single-stage antigen-based vaccine, a multistage and multivalent plasmodium falciparum vaccine would be more efficacious by inducing "multiple layers" of immunity. we have constructed a synthetic gene that encodes for 12 b cell, 6 t cell proliferative, and 3 cytotoxic t lymphocyte epitopes derived from 9 stage-specific p. falciparum antigens corresponding to the sporozoite, liver, erythrocytic asexual, and sexual stages. the gene was expressed in the baculovirus system, and a 41- ... | 1999 | 9990073 |
| plasmodium infection-induced changes in salivary gland proteins of malaria vector anopheles stephensi (diptera:culicidae). | parasitism by plasmodium yoelii yoelii induced 18 polypeptides in the salivary glands of aging malaria vector anopheles stephensi. a polypeptide of low molecular size (30 kda) could generally be induced at all infected stages. on day 5 post blood feeding (pbf), no new polypeptide could be found in the salivary glands. seven polypeptides of low molecular size and 3 of high molecular size could be induced on day 11 pbf, which inducibility coincided with the invasion of the salivary glands by the s ... | 1999 | 10680088 |
| field trials of biolarvicide bacillus thuringiensis var. israelensis strain 164 and the larvivorous fish aplocheilus blocki against anopheles stephensi for malaria control in goa, india. | severe outbreaks of malaria occurred in the coastal villages of the candolim primary health centre (phc) of goa, india, in 1993 and 1994. these outbreaks were associated with accelerated construction activity with an influx of migrant laborers. the weekly application of bacillus thuringiensis var. israelensis (b.t.i.) strain 164 at 1 g/m2 and introduction of the indigenous larvivorous fish aplocheilus blocki in major breeding habitats of anopheles stephensi replaced ongoing ddt spraying and pyre ... | 1998 | 10084141 |
| genetics of mosquito vector competence. | mosquito-borne diseases are responsible for significant human morbidity and mortality throughout the world. efforts to control mosquito-borne diseases have been impeded, in part, by the development of drug-resistant parasites, insecticide-resistant mosquitoes, and environmental concerns over the application of insecticides. therefore, there is a need to develop novel disease control strategies that can complement or replace existing control methods. one such strategy is to generate pathogen-resi ... | 2000 | 10704476 |
| immunization of mice with dna-based pfs25 elicits potent malaria transmission-blocking antibodies. | immunological intervention, in addition to vector control and malaria chemotherapy, will be needed to stop the resurgence of malaria, a disease with a devastating impact on the health of 300 to 500 million people annually. we have pursued a vaccination strategy, based on dna immunization in mice with genes encoding two antigens present on the sexual stages of plasmodium falciparum, pfs25 and pfg27, to induce biologically important antibodies that can block development of the parasite in the anop ... | 1999 | 10085005 |
| phagocytosis does not play a major role in naturally acquired transmission-blocking immunity to plasmodium falciparum malaria. | phagocytosis of plasmodium falciparum sexual stages in vitro and within the mosquito midgut was assayed in order to assess its role in transmission-blocking immunity to malaria. both monocytes/macrophages (mm) and polymorphonuclear neutrophils (pmn) phagocytosed malarial gametes in vitro, but levels of phagocytosis were low. intraerythrocytic gametocytes were not susceptible to phagocytosis. in vitro phagocytosis was positively correlated with levels of antibodies against the gamete surface prot ... | 1999 | 10225892 |
| gene structure and polymorphism of an invertebrate nitric oxide synthase gene. | nitric oxide synthases (noss) are ubiquitous in living organisms. however, little is known about the evolution of this large gene family. the first inducible nos to be described from an invertebrate regulates malaria parasite (plasmodium spp.) development in the mosquito anopheles stephensi. this single copy gene shows the highest homology to the vertebrate neuronal isoforms, followed by decreasing homology to endothelial and inducible isoforms. the open reading frame of 1247 amino acids is enco ... | 1999 | 10333518 |
| prophylactic activity of atovaquone against plasmodium falciparum in humans. | the prophylactic antimalarial activity of atovaquone was determined in a randomized, double-blind, placebo-controlled study of healthy volunteers who were challenged by the bite of plasmodium falciparum-infected anopheles stephensi. subjects were randomly assigned to one of three groups: six received seven daily doses of 750 mg of atovaquone, starting the day before challenge; six received a single dose of 250 mg of atovaquone the day before challenge; and four received placebo. polymerase chain ... | 1999 | 10344660 |
| production of cry11a and cry11ba toxins in bacillus sphaericus confers toxicity towards aedes aegypti and resistant culex populations. | cry11a from bacillus thuringiensis subsp. israelensis and cry11ba from bacillus thuringiensis subsp. jegathesan were introduced, separately and in combination, into the chromosome of bacillus sphaericus 2297 by in vivo recombination. two loci on the b. sphaericus chromosome were chosen as target sites for recombination: the binary toxin locus and the gene encoding the 36-kda protease that may be responsible for the cleavage of the mtx protein. disruption of the protease gene did not increase the ... | 1999 | 10388698 |
| behavioural factors of anopheles stephensi--the principal vector of malaria in calcutta city. | | 1998 | 10389509 |
| dipeptide derivatives of primaquine as transmission-blocking antimalarials: effect of aliphatic side-chain acylation on the gametocytocidal activity and on the formation of carboxyprimaquine in rat liver homogenates. | dipeptide derivatives of primaquine (pq) with reduced oxidative deamination to the inactive metabolite carboxyprimaquine were synthesized and evaluated as a novel class of transmission-blocking antimalarials. methods; antimalarial activity was studied using a model consisting of mefloquine-resistant plasmodium berghei anka 25r/10, balb c mice, and anopheles stephensi mosquitoes. metabolic studies were performed with rat liver homogenates, and the incubates were analyzed by hplc. | 1999 | 10397619 |
| detection and characterization of a mannan-binding lectin from the mosquito, anopheles stephensi (liston). | two lectins from the serum of the mosquito, anopheles stephensi (liston), with distinct characteristics, were detected by agglutination of various animal erythrocytes. the lectins were developmental stage-specific and/or sex-related. one adult female-specific lectin was identified as mannan-specific, and named mosquito mannan-binding lectin (mbl). mbl cross-reacted immunologically with antibodies against a previously characterized cockroach lectin, blaberus discoidalis lectin (bdl1), and its act ... | 1999 | 10406943 |
| buoyancy and diving behavior in mosquito pupae. | mosquito pupal diving behavior has been studied mostly in aedes aegypti and in this species pupal buoyancy varies relative to several factors. the research reported herein addresses the 2 following questions. does diving behavior vary among different mosquito genera and species? how is diving behavior influenced by variation in buoyancy? depth and duration of dive, and dive pattern, were compared among ae. aegypti, culex pipiens, anopheles stephensi, aedes albopictus, and aedes triseriatus. in r ... | 1999 | 10412114 |
| a sex-linked ace gene, not linked to insensitive acetylcholinesterase-mediated insecticide resistance in culex pipiens. | an acetylcholinesterase (ache) gene, ace.x, showing 93% identity of deduced amino acid sequence to anopheles stephensi ace has been cloned from a culex pipiens strain homozygous for insensitive ache (iache) mediated insecticide resistance. dna sequence of genomic dna clones identified exons 2-5. rflp of six clones indicated four possible alleles. linkage analysis located ace.x to chromosome i, less than 0.8 centimorgans from the sex locus, whereas the locus conferring resistance was 2.0 centimor ... | 1998 | 9535157 |
| genotypic diversity among brevibacillus laterosporus strains. | in comparison with other entomopathogenic bacillus species, the genome of brevibacillus laterosporus is poorly characterized. the aim of this study was to examine genetic variability in b. laterosporus by using a range of typing methodologies. strains of b. laterosporus were examined for variation in 13 chromosomal genes encoding enzymes by multilocus enzyme electrophoresis. optimal conditions of pulsed-field gel electrophoresis and randomly amplified polymorphic dna were established that allowe ... | 1999 | 10543843 |
| conservation of a gliding motility and cell invasion machinery in apicomplexan parasites. | most apicomplexan parasites, including the human pathogens plasmodium, toxoplasma, and cryptosporidium, actively invade host cells and display gliding motility, both actions powered by parasite microfilaments. in plasmodium sporozoites, thrombospondin-related anonymous protein (trap), a member of a group of apicomplexan transmembrane proteins that have common adhesion domains, is necessary for gliding motility and infection of the vertebrate host. here, we provide genetic evidence that trap is d ... | 1999 | 10579715 |
| targeted disruption of the plasmodium berghei ctrp gene reveals its essential role in malaria infection of the vector mosquito. | ctrp (circumsporozoite protein and thrombospondin-related adhesive protein [trap]-related protein) of the rodent malaria parasite plasmodium berghei (pbctrp) makes up a protein family together with other apicomplexan proteins that are specifically expressed in the host-invasive stage 1. pbctrp is produced in the mosquito-invasive, or ookinete, stage and is a protein candidate for a role in ookinete adhesion and invasion of the mosquito midgut epithelium. to demonstrate involvement of pbctrp in t ... | 1999 | 10587361 |
| stable germline transformation of the malaria mosquito anopheles stephensi. | anopheline mosquito species are obligatory vectors for human malaria, an infectious disease that affects hundreds of millions of people living in tropical and subtropical countries. the lack of a suitable gene transfer technology for these mosquitoes has hampered the molecular genetic analysis of their physiology, including the molecular interactions between the vector and the malaria parasite. here we show that a transposon, based on the minos element and bearing exogenous dna, can integrate ef ... | 2000 | 10879538 |
| observations on the life cycle of coelomomyces indicus (blastocladiales: coelomomycetaceae) in anopheline mosquitoes from the philippines and thailand. | the water mold coelomomyces indicus iyengar is a widespread pathogen of anopheline mosquitoes in asia and africa, and it infects the copepod microcyclops varicans sars as its crustacean alternate host. this was determined by direct observation of field-infected copepods, selective meiospore encystment on m. varicans, and experimental infections of the copepod with zoospores from both thick and thin-walled meiosporangia. the physiological conditions governing germination of the 2 sporangial types ... | 1999 | 10593068 |
| transmission-blocking immunity to plasmodium falciparum in malaria-immune individuals is associated with antibodies to the gamete surface protein pfs230. | malaria-immune human sera were tested for their ability to affect the infectivity of plasmodium falciparum gametocytes to anopheles stephensi mosquitoes. transmission-reducing effects of the sera were associated with the presence of antibodies to the gamete surface protein, pfs230. enhancement of transmission, manifest as elevated numbers of oocysts relative to controls, was observed for a number of sera, but was not found to be associated with antibodies against pfs230. these results confirm th ... | 1999 | 10599074 |
| blood digestion in the mosquito, anopheles stephensi: the effects of plasmodium yoelii nigeriensis on midgut enzyme activities. | midgut proteases contribute to the success or failure of plasmodium infection of the mosquito. this paper examines the reciprocal effect of plasmodium yoelii nigeriensis on midgut trypsin, chymotrypsin, aminopeptidase and carboxypeptidase in the mosquito anopheles stephensi. the total protein ingested and the rate of protein digestion were unaffected by the parasite, but more protein was ingested at the first than the second bloodmeal. all peptidases were unaffected by the presence of the parasi ... | 1999 | 10633914 |
| ribosomal rna of nosema algerae and phylogenetic relationship to other microsporidia. | microsporidia are intracellular parasites that are common in invertebrates. taxonomic classification is mostly restricted to morphologic and physiologic data. limited data are available about taxonomic classification using dna-sequence data for analysis. we examined the small-subunit (ssu) rdna, the intergenic spacer (its) region, and a part of the large-subunit (lsu) rdna of nosema algerae, a parasite of mosquitoes, taken from a laboratory colony of anopheles stephensi. target gene amplificatio ... | 2000 | 10669131 |
| toward anopheles transformation: minos element activity in anopheline cells and embryos. | the ability of the minos transposable element to function as a transformation vector in anopheline mosquitoes was assessed. two recently established anopheles gambiae cell lines were stably transformed by using marked minos transposons in the presence of a helper plasmid expressing transposase. the markers were either the green fluorescent protein or the hygromycin b phosphotransferase gene driven by the drosophila hsp70 promoter. cloning and sequencing of the integration sites demonstrated that ... | 2000 | 10681436 |
| efficacy of aqueous suspension and granular formulations of bacillus thuringiensis (vectobac) against mosquito vectors. | the efficacy of aqueous suspension (as) and granular (g) formulation of bacillus thuringiensis var. israelensis (vectobac) was tested against the immatures of mosquito vectors in the laboratory and under field conditions. laboratory tests showed that the aqueous suspension was relatively more effective against culex quinquefasciatus than aedes aegypti and anopheles stephensi, the respective lc(50) values being 0.046, 0.060 and 0.190 mg/l. in stream pools, with the application of vectobac as at 1 ... | 2000 | 10708664 |
| comparative susceptibility of different members of the anopheles culicifacies complex to plasmodium vivax. | three colonized species of the anopheles culicifacies complex (species a, b and c) were compared with anopheles stephensi (control) for susceptibility to plasmodium vivax. in feeding experiments involving over 400 paired comparisons, the mean number of oocysts, oocyst rate and sporozoite rate were found to be significantly different. of the test groups, species a had the highest percentage of mosquitoes with oocysts (> 60%) and sporozoites (> 50%). an. culicifacies species b were least susceptib ... | 1999 | 10717735 |
| the effect of chloroquine treatment on the infectivity of plasmodium chabaudi gametocytes. | the antimalarial drug chloroquine has been reported to increase the infectivity of the forms of blood-stage malaria parasites (gametocytes) that are capable of infecting mosquito vectors. this effect has been demonstrated convincingly in the short term (12 h post treatment), although several authors have suggested infectivity enhancement a week or more after treatment. we carried out experiments to investigate the effects of chloroquine on the longer-term infectivity of gametocytes of the rodent ... | 1999 | 10428639 |
| 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 ... | 1999 | 10461947 |
| survey of termite-inhabited soil and mosquito breeding sites in lucknow, india for potential mycopathogens of anopheles stephensi. | during a short survey of soil and mosquito breeding sites in lucknow, india for potential mycopathogen from a period of august-october 1996, 11 species of fungi in 5 genera were isolated using live mosquito larvae as host, aspergillus flavus, a. fumigatus and fusarium semitectum were the most frequently isolated species. other fungi recorded were a. niger, a. ochraceus, a. terreus, a. versicolor, geotrichum candidum, penicillium verrucosum, paecilomyces sp. and fusarium sp. (liseola/elegans comp ... | 1998 | 10481288 |
| blood-stage dynamics and clinical implications of mixed plasmodium vivax-plasmodium falciparum infections. | we present a mathematical model of the blood-stage dynamics of mixed plasmodium vivax-plasmodium falciparum malaria infections in humans. the model reproduces features of such infections found in nature and suggests several phenomena that may merit clinical attention, including the potential recrudescence of a long-standing, low-level p. falciparum infection following a p. vivax infection or relapse and the capacity of an existing p. vivax infection to reduce the peak parasitemia of a p. falcipa ... | 1999 | 10497972 |
| the effect of plasmodium yoelii nigeriensis infection on the feeding persistence of anopheles stephensi liston throughout the sporogonic cycle. | vector-borne parasites such as malaria have been shown to modify the feeding behaviour of their invertebrate hosts so as to increase the probability of transmission. however, evolutionary consideration of developmental changes in malaria within anopheles mosquitoes suggests that the nature of altered feeding by mosquitoes should differ depending on the developmental stage of the parasite. we present laboratory evidence that the feeding persistence of female anopheles stephensi towards a human ho ... | 1999 | 10518321 |
| cd4(+) t-cell- and gamma interferon-dependent protection against murine malaria by immunization with linear synthetic peptides from a plasmodium yoelii 17-kilodalton hepatocyte erythrocyte protein. | most work on protective immunity against the pre-erythrocytic stages of malaria has focused on induction of antibodies that prevent sporozoite invasion of hepatocytes, and cd8(+) t-cell responses that eliminate infected hepatocytes. we recently reported that immunization of a/j mice with an 18-amino-acid synthetic linear peptide from plasmodium yoelii sporozoite surface protein 2 (ssp2) in titermax adjuvant induces sterile protection that is dependent on cd4(+) t cells and gamma interferon (ifn- ... | 1999 | 10531206 |
| 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 |
| determination of mosquito bloodmeal ph in situ by ion-selective microelectrode measurement: implications for the regulation of malarial gametogenesis. | malarial gametocytes circulate in the peripheral blood of the vertebrate host as developmentally arrested intra-erythrocytic cells, which only resume development into gametes when ingested into the bloodmeal of the female mosquito vector. the ensuing development encompasses sexual reproduction and mediates parasite transmission to the insect. in vitro the induction of gametogenesis requires a drop in temperature and either a ph increase from physiological blood ph (ca ph 7.4) to about ph 8.0, or ... | 2000 | 10874717 |
| biocontrol of the sugarcane borer eldana saccharina by expression of the bacillus thuringiensis cry1ac7 and serratia marcescens chia genes in sugarcane-associated bacteria. | the cry1ac7 gene of bacillus thuringiensis strain 234, showing activity against the sugarcane borer eldana saccharina, was cloned under the control of the tac promoter. the fusion was introduced into the broad-host-range plasmid pkt240 and the integration vector pjff350 and without the tac promoter into the broad-host-range plasmids pml122 and pkmm0. these plasmids were introduced into a pseudomonas fluorescens strain isolated from the phylloplane of sugarcane and the endophytic bacterium herbas ... | 2000 | 10877771 |
| [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 |
| cloning and characterization of a bacillus thuringiensis serovar higo gene encoding a novel class of the delta-endotoxin protein, cry27a, specifically active on the anopheles mosquito. | a novel gene encoding a 98-kda mosquitocidal delta-endotoxin protein, designated cry27a, was cloned from a bacillus thuringiensis serovar higo strain. the cry27a protein contained the five sequence blocks of amino acids commonly conserved in most b. thuringiensis cry proteins. relatively high homologies, ranging from 43.0% to 84.4%, existed between the cry27a protein and several established classes of mosquitocidal cry proteins (cry4a, cry10a, cry19a, cry19b, and cry20a) in the sequence of 51 n- ... | 2000 | 10879975 |
| parasporin, a human leukemic cell-recognizing parasporal protein of bacillus thuringiensis. | an unusual property, human leukemic cell-recognizing activity, associated with parasporal inclusions of a noninsecticidal bacillus thuringiensis soil isolate was investigated, and a protein (named parasporin in this study) responsible for the activity was cloned. the parasporin, encoded by a gene 2,169 bp long, was a polypeptide of 723 amino acid residues with a predicted molecular weight of 81, 045. the sequence of parasporin contained the five conserved blocks commonly found in b. thuringiensi ... | 2000 | 10882663 |
| mutations in plasmodium falciparum cytochrome b that are associated with atovaquone resistance are located at a putative drug-binding site. | atovaquone is the major active component of the new antimalarial drug malarone. considerable evidence suggests that malaria parasites become resistant to atovaquone quickly if atovaquone is used as a sole agent. the mechanism by which the parasite develops resistance to atovaquone is not yet fully understood. atovaquone has been shown to inhibit the cytochrome bc(1) (cyt bc(1)) complex of the electron transport chain of malaria parasites. here we report point mutations in plasmodium falciparum c ... | 2000 | 10898682 |
| comparison of two alpha-cyano pyrethroids when impregnated into bednets against a pyrethroid resistant and susceptible strain of anopheles stephensi (diptera: culicidae) and their f1 progeny. | the two alpha-cyano pyrethroid insecticides lambda-cyhalothrin and alpha-cypermethrin were tested as bednet treatments at a target dose of 20 mg m-2. to establish their efficacy, female pyrethroid resistant and susceptible anopheles stephensi liston, and the f1-hybrids were allowed to fly freely in a room with a human subject under an impregnated net. both treatments provided good personal protection by significantly reducing the number of blood fed mosquitoes compared to an untreated control ne ... | 2000 | 10948371 |
| host-virus interactions during malaria infection in hepatitis b virus transgenic mice. | we have previously shown that hepatitis b virus (hbv) replication is abolished in the liver of hbv transgenic mice by inflammatory cytokines induced by hbv-specific cytotoxic t cells and during unrelated viral infections of the liver. we now report that intrahepatic hbv replication is also inhibited in mice infected by the malaria species plasmodium yoelii 17x nl. p. yoelii infection triggers an intrahepatic inflammatory response characterized by the influx of natural killer cells, macrophages, ... | 2000 | 10952722 |
| lipid utilization for ovarian development in an autogenous mosquito, culex pipiens molestus (diptera: culicidae). | during the first ovarian cycle, autogenous female mosquitoes develop their ovaries in the absence of blood feeding. in autogenous culex pipiens molestus (forskal), complete yolk deposition was observed 2 d after emergence, even when no feeding was allowed (starved). neutral lipids in cx. p. molestus increased during the pupal stage, abruptly declined after emergence, and again increased on day 3. in contrast, neutral lipids decreased in anautogenous anopheles stephensi (liston) and cx. p. pallen ... | 2000 | 11004785 |
| 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 |
| bactericidal effects of sugar-fed antibiotics on resident midgut bacteria of newly emerged anopheline mosquitoes (diptera: culicidae). | a protocol was developed for significantly reducing resident midgut bacteria in newly emerged anopheline mosquitoes using a combination of antibiotics. pupa harvested from colony-reared anopheles gambiae s.l. giles and anopheles stephensi (liston) were placed in cages wiped previously with 70% alcohol and kept under uv light for 24 h. emerging adult mosquitoes were fed for 3 consecutive days on antibiotic solution, consisting of 0.4% gentamicin sulfate and 1% penicillin-streptomycin solution in ... | 2000 | 10730495 |
| variations in the response to bacillus sphaericus toxins in different strains of anopheles stephensi liston. | bacillus sphaericus has a potential of use as a larvicide in water storage practices but no such study has been done against anopheles stephensi. baseline susceptibility status of eleven wild and three mutant strains of an. stephensi to spherix, a formulation of b. sphaericus, strain b-101 (serotype h5a, 5b) was determined to find the variations in the degree of their response to b. sphaericus toxins and to study the possibility of development of resistance. the lc50 and lc90 values of different ... | 1998 | 10748558 |
| molecular characterization of a prophenoloxidase cdna from the malaria mosquito anopheles stephensi. | some refractory anopheline mosquitoes are capable of killing plasmodium, the causative agent of malaria, by melanotic encapsulation of invading ookinetes. phenoloxidase (po) appears to be involved in the formation of melanin and toxic metabolites in the surrounding capsule. a cdna encoding anopheles stephensi prophenoloxidase (ans-propo) was isolated from a cdna library screened with an amplimer produced by reverse transcriptase polymerase chain reaction (rt-pcr) with degenerate primers designed ... | 2000 | 10762420 |
| 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 entomopathogenic fungus, beauveria bassiana on larvae of three species of mosquitoes. | beauveria bassiana, an entomopathogenic fungus, was evaluated for its potential against second and third instar larvae of culex quinquefasciatus, anopheles stephensi and aedes aegypti. conidiospores of this fungus were effective in causing infection leading to mortality of different larval instars. larvae of cx. quinquefasciatus were more susceptible to infection than an. stephensi and the second instar larvae of these two species were more susceptible than third instar larvae. larvae of ae. aeg ... | 1999 | 10783749 |
| 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 |
| [characterization of entomopathogenic bacillus samples isolated in senegal and study of their toxicity for malaria vectors]. | a screening program developed in senegal to isolate new strains of entomopathogenic bacillus has led to the isolation of 194 strains of bacillus thuringiensis and 9 strains of bacillus sphaericus from various sites and insect samples. the characterization of these strains regarding their h serotype, their crystal composition and their toxicity against mosquitoes (culex pipiens, aedes aegypti and anopheles stephensi) has led to the isolation of 27 mosquitocidal strains. as malaria is an important ... | 1998 | 10797955 |
| a subdominant cd8(+) cytotoxic t lymphocyte (ctl) epitope from the plasmodium yoelii circumsporozoite protein induces ctls that eliminate infected hepatocytes from culture. | previous studies indicated that the plasmodium yoelii circumsporozoite protein (pycsp) 57-70 region elicits t cells capable of eliminating infected hepatocytes in vitro. herein, we report that the pycsp58-67 sequence contains an h-2(d) binding motif, which binds purified k(d) molecules in vitro with low affinity (3, 267 nm) and encodes an h-2(d)-restricted cytotoxic t lymphocyte (ctl) epitope. immunization of balb/c mice with three doses of a multiple antigen peptide (map) construct containing f ... | 2000 | 10816491 |
| 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 |