Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| the impact of variations in temperature on early plasmodium falciparum development in anopheles stephensi. | the effect of temperature on early plasmodium falciparum development was examined in anopheles stephensi. the rates of both ookinete development and bloodmeal digestion were lengthened as temperatures decreased from 27 to 21 degrees c. however, low temperatures (21-27 degrees c) did not significantly influence infection rates or densities of either ookinetes or oocytes. in contrast, high temperatures (30 and 32 degrees c) significantly impacted parasite densities and infection rates by interferi ... | 1995 | 8559585 |
| plasmodium yoelii nigeriensis: the effect of high and low intensity of infection upon the egg production and bloodmeal size of anopheles stephensi during three gonotrophic cycles. | anopheles stephensi mosquitoes showed a reduction in fecundity over 3 successive gonotrophic cycles, after becoming infected with plasmodium yoelii nigeriensis. this effect could be observed at high oocyst burdens (> 75) or at low oocyst burdens (mean of 4.36). mean bloodmeal size of the infected mosquitoes was significantly reduced only when feeding upon a mouse with a high gametocytaemia and the conversion of the bloodmeal into eggs by the infected mosquitoes was disrupted. patterns of infecte ... | 1995 | 8559587 |
| binding of the cryivd toxin of bacillus thuringiensis subsp. israelensis to larval dipteran midgut proteins. | ligand-blotting experiments on dipteran brush border membrane vesicles (bbmvs) showed binding of cryivd toxin of bacillus thuringiensis subsp. israelensis to proteins of 148 kda in anopheles stephensi and of 78 kda in tipula oleracea, both species being susceptible to cryivd. binding of cryivd with bbmvs of a. stephensi resulted in a stronger signal than with bbmvs of t. oleracea. likewise, larvae of a. stephensi are 10,000-fold more susceptible to the cryivd toxin than are larvae of t. oleracea ... | 1995 | 16535074 |
| bacterial population dynamics in three anopheline species: the impact on plasmodium sporogonic development. | the functional role of bacteria in the midgut of adult mosquitoes is unknown. in this study, we examined the population dynamics of midgut bacteria of laboratory reared anopheles stephensi, an. gambiae, and an. albimanus. mosquito midguts were dissected under sterile conditions and examined for the presence of bacteria using standard microbiologic techniques. ninety percent and 73% (n = 30) of newly emerged an. gambiae and an. stephensi, respectively, harbored bacteria. in contrast, only 17% (n ... | 1996 | 8619451 |
| sodium beta-artelinate--a new potential gametocytocide. | the water-soluble artemisinin analogue sodium beta-artelinate, a fast-acting blood schizontocide, was evaluated for gametocytocidal action against simian malaria plasmodium cynomolgi b, and a single dose of the compound has been found to be an effective gametocytocide by both oral and intravenous routes. the compound was able to sterilize the circulating gametocytes in rhesus monkey, resulting in loss of mosquito infectivity and oocyst development in the anopheles stephensi. however, no sporonto ... | 1996 | 8631376 |
| the nigerian i/cdc strain of plasmodium ovale in chimpanzees. | the chimpanzee is the only animal host currently available that can support the development of the human malaria parasite plasmodium ovale. thirty-one infections with the nigerian i/cdc strain were induced in splenectomized chimpanzees. maximum parasite counts ranged from 1,240 to 127,224/microliters. infections were transient and unpredictable. anopheles stephensi, anopheles gambiae, anopheles freeborni, and anopheles dirus mosquitoes were infected by feeding through parafilm membranes on hepar ... | 1996 | 8636850 |
| cloning and expression of the first anaerobic toxin gene from clostridium bifermentans subsp. malaysia, encoding a new mosquitocidal protein with homologies to bacillus thuringiensis delta-endotoxins. | a gene (cbm71) encoding a 71,128-da mosquitocidal protein (cbm71) was obtained by screening a size-fractionated xbai digest of total genomic dna from clostridium bifermentans subsp. malaysia ch18 with two gene-specific oligonucleotide probes. the sequence of the cbm71 protein, as deduced from the sequence of cbm71, corresponds to that of the 66-kda protein previously described as one of the mosquitocidal components of c. bifermentans subsp. malaysia. cbm71 shows limited similarities with bacillu ... | 1996 | 8655486 |
| experimental evidence against replication or dissemination of hepatitis c virus in mosquitoes (diptera:culicidae) using detection by reverse transcriptase polymerase chain reaction. | in 3 laboratory experiments, mosquitoes were fed hepatitis c virus (hcv)-rna positive blood by using membrane feeders, separated into head, thorax, and abdomen, and tested by a reverse transcriptase polymerase chain reaction for hcv-rna. hcv did not replicate or disseminate in mosquitoes that had ingested blood from patients that were hcv-viremic positive. when yellow fever mosquitoes, aedes aegypti (l.), were held for 1, 3, 7, 14, and 21 d after feeding, hcv-rna was detected in the abdomens of ... | 1996 | 8667387 |
| current status of anopheles stephensi response to various insecticides in some areas of the thar desert. | investigations on the current response of a. stephensi. to six insecticides viz. ddt, dieldrin, malathion, fenitrothion, propoxur and permethrin, were carried out in 3 districts i.e. barmer, jodhpur and pali, of the thar desert. the species was found resistant to ddt and dieldrin, partially resistant to malathion and susceptible to fenitrothion, propoxur and permethrin. dieldrin and malathion resistance has been detected for the first time in the thar desert. lethal concentrations (lc50 & lc95) ... | 1996 | 8707370 |
| rapid decomposition of permethrin in the outer fly of an experimental tent in pakistan. | the residual activity of permethrin on the canvas of an experimental tent, used by nomadic refugees in a malarious area in northern pakistan, was assessed. a permethrin emulsion sprayed on the inner sheet of a pitched double-fly tent (0.5 g/m2) had an effective residue for at least 6 months in bioassays using the local malaria vectors, anopheles stephensi and anopheles culcifacies. however, a high concentration of permethrin (2 g/m2) sprayed on the inner surface of the outer tent, simulating sin ... | 1996 | 8723269 |
| self-protection from malaria vectors in pakistan: an evaluation of popular existing methods and appropriate new techniques in afghan refugee communities. | experimental huts were used to measure the impact of several techniques for self-protection from malaria vectors in pakistan. an electric fan, pyrethrum coils, untreated curtains, pyrethroid-vaporizing mats and permethrin-impregnated curtains reduced the total catches of blood-fed anopheles stephensi by 27%, 36%, 47%, 56% and 65%, respectively. the most marked effect of all the interventions was in reducing the numbers of mosquitoes entering the huts, although all the techniques, except for the ... | 1996 | 8758148 |
| bioefficacy of mosquito mat, coil and dispenser formulations containing allethrin group of synthetic pyrethroids against mosquito vectors. | the bioefficacy of mats, coils and dispensers containing allethrin group of synthetic pyrethroids was studied against laboratory strains of culex quinquefasciatus, aedes aegypti and anopheles stephensi. except esbiothrin in the mat formulation which was 100 and 178 times more effective against cx. quinquefasciatus than against ae. aegypti and an. stephensi with kt50 of 0.005, 0.5 and 0.89 min. respectively, all the three allethrins in mat or coil formulations were equally effective against the t ... | 1996 | 8810142 |
| lactate dehydrogenase as a marker of plasmodium infection in malaria vector anopheles. | lactate dehydrogenase (ldh) electrophoresis showed the presence of plasmodium yoelii yoelii in anopheles stephensi and an. gambiae. the ldh appeared as an additional band (pldh) whose activity was more intense with 3-acetyl pyridine adenine dinucleotide as coenzyme than with beta nicotin-amide adenine dinucleotide. several allelic forms occurred both in the vector and the host. the isoelectric point of ldh, similar in the vector and host, differed from those of ldh from mosquito and mouse. the p ... | 1996 | 8827592 |
| induction of anti-malarial transmission blocking immunity with a recombinant ookinete surface antigen of plasmodium berghei produced in silkworm larvae using the baculovirus expression vector system. | we have studied pbs21, a major ookinete surface protein of plasmodium berghei, for the development of a model transmission blocking immunogen. in the mouse, recombinant pbs21 expressed in the escherichia coli expression system (ecrpbs21) is not as effective in inducing transmission blocking antibodies as native pbs21 (npbs21), possibly because of differences in post-translational processing between ecrpbs21 and npbs21. in an attempt to improve the efficacy of the recombinant molecule, we describ ... | 1996 | 8852407 |
| effects of variations in a formulated protein meal on the fecundity and fertility of female mosquitoes. | a formulated protein meal developed by kogan (1990) for adult female aedes aegypti mosquitoes was evaluated and modified to increase egg and pupal yield. a vigorous laboratory colony was maintained with the females fed exclusively on this dietary formula for about twenty-five generations over more than 2 years. extra modifications were made to produce a diet suitable for anopheles arabiensis and anopheles stephensi females to produce eggs. both formulations contain bovine albumin, haemoglobin an ... | 1996 | 8887337 |
| 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 |
| inhibition of mosquito salivary gland apyrase activity by antibodies produced in mice immunized by bites of anopheles stephensi mosquitoes. | mice (balb/c) were immunized to mosquito saliva by repeated bites of anopheles stephensi mosquitoes. studies were conducted on the ability of these mice to develop antibodies against the apyrase component of the saliva. by means of immunoprecipitation procedures and western blot analysis, we demonstrated the presence of antiapyrase antibodies to the mosquito saliva. furthermore, these antibodies were able to inhibit apyrase activity. serum titers of 1:20 were able to inhibit approximately 90% of ... | 1996 | 8916799 |
| 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 |
| in-vitro cultivation of exoerythrocytic stages of plasmodium cynomolgi in hepatocytes of macaca radiata. | hepatocytes from bonet monkey (macaca radiata) obtained by perfusion of a liver biopsy were infected in-vitro with plasmodium cynomolgi bastianellii sporozoites raised in anopheles stephensi. the development of exoerythrocytic (ee) stages was seen under phase contrast microscope and by giemsa staining. multinucleated ee-stages were seen in the cultured hepatocytes on day 7-8 post-sporozoite inoculation. | 1996 | 8952170 |
| feeding behaviour of anopheles stephensi in calcutta. | 1996 | 8952175 | |
| characterization of six highly mosquitocidal bacillus thuringiensis strains that do not belong to h-14 serotype. | four strains belonging to bacillus thuringiensis serovars thompsoni, malaysiensis, canadensis, jegathesan and two auto-agglutinating b.t. strains were identified as being highly toxic to the mosquito larvae of the species aedes aegypti, anopheles stephensi, and culex pipiens. their larvicidal and hemolytic activities were determined and compared with those of strains known to be highly mosquitocidal and/or cytolytic from serovars of b.t. israelensis, morrisoni, darmstadiensis, medellin, kyushuen ... | 1996 | 8555944 |
| raising activity of bacillus thuringiensis var. israelensis against anopheles stephensi larvae by encapsulation in tetrahymena pyriformis (hymenostomatida:tetrahymenidae). | toxicity of bacillus thuringiensis var israelensis (b.t.i.) against surface-feeding mosquito larvae of anopheles stephensi was enhanced by encapsulation in the protozoan tetrahymena pyriformis. in the laboratory, larvae died about 8 times faster when exposed to protozoan cells filled with b.t.i. than when exposed to the same concentrations of b.t.i. alone. best larvicidal activities were achieved with ratios of 1:200-1:500 t. pyriformis cells to b.t.i. spores. the concentration of b.t.i. needed ... | 1996 | 9046467 |
| 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 |
| 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 |
| adaptive larval thermotolerance and induced cross-tolerance to propoxur insecticide in mosquitoes anopheles stephensi and aedes aegypti. | fourth-instar larvae of mosquitoes anopheles stephensi and aedes aegypti normally died within 90 min at 43 degrees c. pre-exposure to high but sublethal temperatures conferred adaptive thermotolerance, dependent on the temperature and the duration of pre-exposure. adaptive cross-tolerance to propoxur (a carbamate insecticide) was also induced in larvae by pre-exposing them to sublethal temperatures. pre-exposure to sublethal concentrations of propoxur was found to confer cross-thermotolerance to ... | 1996 | 8887340 |
| toxicity of insecticides to toxorhynchites splendens and three vector mosquitos and their sublethal effect on biocontrol potential of the predator. | toxicity of six larvicides ie fenthion, temephos, malathion, deltamethrin, alphamethrin (fendona), oms 3031 and five adulticides ie malathion, fenitrothion, propoxur, deltamethrin, permethrin to aedes aegypti, culex quiquefasciatus, anopheles stephensi and the predator, toxorhynchites splendens was studied for evaluating safety margin. concentrations of alphamethrin that killed 50% larvae of t. splendens were 53 and 12 times more than that which killed cx. quinquefasciatus and ae. aegypti. in ca ... | 1996 | 9031419 |
| effect of volatiles from neem and other natural products on gonotrophic cycle and oviposition of anopheles stephensi and an. culicifacies (diptera: culicidae). | the gonotrophic cycle of female anopheles was impaired by exposure to volatiles of neem, (azadirachta indica), reetha, (sapindus mukorossi), and garlic, (allium sativum), but not to castor seeds and cotton seed oil. a brief exposure to contact or volatile extracts from neem suppressed rather than inhibited oviposition. complete inhibition of oviposition was observed by exposure of mosquitoes to neem oil and 1 fraction containing volatile components. vitellogenesis was impaired irreversably by lo ... | 1996 | 8742520 |
| larvicidal activity of the naphthylisoquinoline alkaloid dioncophylline a against the malaria vector anopheles stephensi. | the larvicidal activity of dionocophylline a, a naphthylisoquinoline alkaloid derived from the tropical vine triphyophyllum peltatum (dioncophyllaceae), was investigated against the malaria vector anopheles stephensi. in direct and indirect inhibition assays it was demonstrated that the younger larval stages were very sensitive towards this natural product, with lc50 values below 1 mg/l. pronounced effects were observed within 4 h of exposure. aging larvae, however, were less sensitive, while pu ... | 1996 | 8953426 |
| inheritance and linkage of aspartate aminotransferase in anopheles stephensi. | 1996 | 8978908 | |
| mosquitoes (diptera:culicidae) breeding in brackish water: female ovipositional preferences or larval survival? | four species of mosquitoes were abundant in concrete reservoir tanks containing brackish water that ranged from 16 to 39% sea water. the ability of the larvae to survive in various salinities was compared for each species with the ovipositional preferences of the adult females to determine whether the 2 traits were correlated. southern house mosquito, culex quinquefasciatus say, normally was not present in the tanks but survived well in salinities up to 25% sea water. however, gravid females alm ... | 1996 | 8699444 |
| variation in cuticular hydrocarbons among strains of anopheles (cellia) stephensi liston possibly related to prior insecticide exposure. | cuticular lipids were extracted in hexane from the females of four strains of anopheles stephensi and separated by capillary gas chromatography. when the chromatograms produced were quantified and compared by discriminant analysis, compositional variations in the hydrocarbons indicated that two of the strains, 'russ' (originally isolated in the former (u.s.s.r.) and 'iraq' (from iraq), both of which were susceptible to ddt and malathion, could be confidently separated from 'beech' from india and ... | 1997 | 9425368 |
| electrophoretic separation and identification of phenoloxidases in hemolymph and midgut of adult anopheles stephensi mosquitoes. | anopheles mosquitoes frequently respond to invading malaria parasites with a rejection mechanism consisting of phenoloxidase-mediated melanization of ookinetes in the mosquito midgut epithelium. the relative roles of hemolymph vs. midgut phenoloxidase in this rejection mechanism is unclear. we have separated and identified phenoloxidase isozymes from midgut and hemolymph of anopheles stephensi by native gel electrophoresis followed by zymography. the isozymes from the 2 sites had distinctively d ... | 1997 | 9267412 |
| laboratory evaluation of the biocontrol potential of mesocyclops thermocyclopoides (copepoda: cyclopidae) against mosquito larvae. | biocontrol potential of mesocyclops thermocyclopoides against first instar larvae of anopheles stephensi, aedes aegypti and culex quinquefasciatus was studied under laboratory conditions. it was found that m. thermocyclopoides had the highest predation efficacy against ae. aegypti followed by an. stephensi and cx. quinquefasciatus. there was a significant reduction in the predation efficacy of m. thermocyclopoides against cx. quinquefasciatus in the presence of alternate food (p < 0.01). the cag ... | 1997 | 9656415 |
| an equipment for the study of behavioural responses of mosquitoes to residual application of synthetic insecticides. | excito-repellency (e-r) test box was developed to study under laboratory conditions the refractory behaviour of mosquitoes to residual application of synthetic insecticides. the observations obtained through the equipment were compared with another behavioural study of mosquitoes using standard who irritability test kit. during 16 hour exposure period there was restricted entry of mosquitoes in ddt treated chamber of e-r test box for all mosquito species tested (anopheles stephensi, aedes aegypt ... | 1997 | 9465527 |
| the effect of plasmodium yoelii nigeriensis infection on ovarian protein accumulation by anopheles stephensi. | both anopheline and culicine mosquitoes have been shown to incur a reduction in reproductive fitness when infected with malaria parasites. the agent of rodent malaria, plasmodium yoelii nigeriensis, was used as a laboratory model to investigate changes in the accumulation of protein in the ovaries of anopheles stephensi when infected with oocysts or when feeding on mice with heavy asexual parasitaemia but no mature gametocytes. herein we report that during the early phases of the gonotrophic cyc ... | 1997 | 9134561 |
| 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 |
| 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 |
| 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 |
| 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 |
| plasmodium yoelii sporozoite infectivity varies as a function of sporozoite loads in anopheles stephensi mosquitoes. | mechanisms by which plasmodium sporozoites survive and maintain their infectivity within the salivary glands of mosquitoes are unknown. in this study we establish a relationship between the number of sporozoites present in the salivary glands of individual mosquitoes (sporozoite load) and sporozoite infectiousness (or "quality") as measured by infections in balb/c or icr mice. when plasmodium yoelii-infected anopheles stephensi mosquitoes were each allowed to feed on a single mouse, we noted tha ... | 1997 | 9267407 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| contribution of the 65-kilodalton protein encoded by the cloned gene cry19a to the mosquitocidal activity of bacillus thuringiensis subsp. jegathesan. | two new crystal protein genes, cry19a and orf2, isolated from bacillus thuringiensis subsp. jegathesan were cloned and characterized. the cry19a gene encodes a 74.7-kda protein, and the orf2 gene encodes a 60-kda protein. cry19a contains the five conserved blocks present in most b. thuringiensis delta-endotoxins. the orf2 amino acid sequence is similar to that of the carboxy terminus of cry4 proteins. the cry 19a gene was expressed independently or in combination with orf2 in a crystal-negative ... | 1997 | 9361431 |
| 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 |
| 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 |
| identification of a gene for cyt1a-like hemolysin from bacillus thuringiensis subsp. medellin and expression in a crystal-negative b. thuringiensis strain. | a gene designated cyt1ab1, encoding a 27,490-da protein, was isolated from bacillus thuringiensis subsp. medellin (h30 serotype) by using an oligonucleotide probe corresponding to the cyt1aa1 gene. the sequence of the cyt1ab1 protein, as deduced from the sequence of the cyt1ab1 gene, was 86% identical to that of the cyt1aa1 protein and 32% identical to that of the cyt2aa1 protein from b. thuringiensis subsp. kyushuensis. the cyt1ab1 gene was flanked upstream by a p21 gene, in the same orientatio ... | 1997 | 9023925 |
| 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 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 |
| 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 |
| 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 |
| behavioural factors of anopheles stephensi--the principal vector of malaria in calcutta city. | 1998 | 10389509 | |
| 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 |
| [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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| functional complementation of nontoxic mutant binary toxins of bacillus sphaericus 1593m generated by site-directed mutagenesis. | alanine residues were substituted by site-directed mutagenesis at selected sites of the n- and c-terminal regions of the binary toxin (51- and 42-kda peptides) of b. sphaericus 1593m, and the mutant toxins were cloned and expressed in escherichia coli. bioassays with mosquito larvae, using binary toxins derived from individual mutants, showed that the substitution of alanine at some sites in both the 51-kda and the 42-kda peptides resulted in a total loss of activity. surprisingly, after mixing ... | 1998 | 9464418 |
| seasonal prevalence of anopheles stephensi larvae and existence of two forms of the species in an urban garden in calcutta city. | a study on the occurrence and seasonal prevalence of anopheles stephensi (principal vector of malaria in calcutta) larvae in an urban garden in central calcutta revealed their presence in collections of fresh and/or rain water in various kinds of temporary and permanent breeding habitats. breeding sites in shady areas were preferred in comparison to those receiving direct sunlight. the density of an. stephensi larvae was highest in earthen and lowest in wooden pots throughout the study period, a ... | 1998 | 10319556 |
| relative efficacy of synthetic pyrethroid-impregnated fabrics against mosquitoes under laboratory conditions. | the efficacy of synthetic pyrethroid-impregnated fabrics was evaluated against anopheles stephensi, aedes aegypti, and culex quinquefasciatus, under laboratory conditions. results revealed that delta-methrin was significantly superior in comparison to lambdacyhalothrin and cyfluthrin. results of bioassay tests revealed that deltamethrin was 1.5 and 1.9 times more effective than lambdacyhalothrin and cyfluthrin, respectively, against an. stephensi exposed to cotton fabric treated at 100 g/m2. del ... | 1998 | 10084134 |
| evaluation of repellent activities of cymbopogon essential oils against mosquito vectors of malaria, filariasis and dengue fever in india. | essential oils of four species and two hybrid varieties of cymbopogon grasses were evaluated for their repellent properties against the major vector mosquitoes, namely, anopheles stephensi, culex quinque-fasciatus and aedes aegypti, both in laboratory and field. the magnitude of repellency in the cymbopogon essential oils was found to be of moderate to high order. all grass species protected completely from mosquito bites for 4 hrs, whereas c. nardus provided protection for as much as 8-10 hrs o ... | 1998 | 23195906 |
| induced immunity against the mosquito anopheles stephensi liston (diptera: culicidae): effects on mosquito survival and fecundity. | mice were immunised three to five times with extracts of anopheles stephensi heads, midguts, ovaries or fat bodies. at each immunisation the effects of feeding an. stephensi on the mice was determined, and changes in mosquito longevity and fecundity examined as the immune response developed. although variability was common between control cages, significant and consistent reductions in mosquito longevity were observed when midguts were used as immunogens. other extracts caused transient reductio ... | 1998 | 9846609 |
| identification of electrophoretically separated proteases from midgut and hemolymph of adult anopheles stephensi mosquitoes. | digestion of blood within the mosquito midgut is mediated primarily by a series of proteases, and several previous studies have described protease activity within homogenates of the midgut of the malaria vector anopheles stephensi. we have expanded on these previous data by resolving protease isoforms from the midgut as well as the hemolymph of adult an. stephensi mosquitoes via gel electrophoresis and zymography. using this procedure, we have been able to identify multiple isozymes of trypsin, ... | 1998 | 9576512 |
| a mosquito (anopheles stephensi) angiotensin i-converting enzyme (ace) is induced by a blood meal and accumulates in the developing ovary. | angiotensin i-converting enzyme (ace) has a key role in regulating levels of several circulating peptides in mammals and has a vital role in male fertility. ace has recently been found in insects, where its role is unclear. a mutant allele of the ace gene (ance) of drosophila melanogaster is embryonic lethal, indicating an important role for the enzyme in development. we now report the presence of ace in female anopheles stephensi mosquitoes and that the enzyme is induced by a blood meal. ace ac ... | 1999 | 10437776 |
| gender-related efficacy difference to an extended duration formulation of topical n,n-diethyl-m-toluamide (deet). | a clinical trial (n = 120, 60 males and 60 females) was conducted to assess the efficacy of an extended duration tropical insect/arthropod repellent (edtiar) topical formulation of n,n-diethyl-m-toluamide (deet). the amount of edtiar (mean +/- confidence interval), applied by participants in accordance with label directions, was not significantly different between females (3.66 +/- 0.32 mg/cm2) and males (3.45 +/- 0.33 mg/cm2). there also was no significant difference in the number of anopheles ... | 1999 | 10348243 |
| rubidium marking of anopheles stephensi (diptera: culicidae). | immature anopheles stephensi liston were reared in untreated water and water containing eight 2-fold dilutions of rubidium (rb) from 1,000 to 7.8 ppm to determine the concentration that allowed reliable detection and produced the least toxic effects as measured by adult emergence, weight, and survival. the amount of rb detected in mosquitoes increased positively with increasing concentrations in the rearing water. concentrations > or = 31.2 ppm rb in the rearing water provided high and consisten ... | 1999 | 10083749 |
| laboratory evaluation of ai3-37220, ai3-35765, cic-4, and deet repellents against three species of mosquitoes. | four repellents, n,n-diethyl-3-methyl-benzamide (deet), 2-hydroxy-methyl-cyclohexyl acetic acid lactone (cic-4), and 2 piperidines (1-[3-cyclohexen-1-ylcarbonyl] piperidine [ai3-35765] and 1-[3-cyclohexen-1-ylcarbonyl]-2-methylpiperidine [ai3-37220]) were evaluated alone and in combination against aedes aegypti, anopheles stephensi, and culex quinquefasciatus using a modified in vitro test system. this method was a valuable tool for comparing effective concentrations of the new compounds. becaus ... | 1999 | 10480126 |
| evaluation of cyfluthrin and fenfluthrin for their insecticidal activity against three vector mosquitoes. | the ec50/ec90 concentrations of cyfluthrin and fenfluthrin were tested for their activity against different developmental stages of three important vector mosquitoes viz., anopheles stephensi liston, aedes aegypti (linn.) and culex quinquefasciatus say. the ec90 concentrations of both cyfluthrin and fenfluthrin showed ovicidal effect on an. stephensi and ae. aegypti whereas ec90 of cyfluthrin checked the hatching of eggs completely in cx. quinquefasciatus. fenfluthrin at ec50 concentration reduc ... | 1999 | 10810595 |
| influence of igr treatment on oviposition of three species of vector mosquitos at sublethal concentrations. | sublethal effect of hexaflumuron, an insect growth regulator (igr), on the oviposition of three species of vector mosquitos. culex quinquefasciatus, aedes aegypti and anopheles stephensi was studied. significant reduction in oviposition was observed in the females of the above three species derived from fourth instar larvae and pupae exposed to sublethal (ei5 and ei50) doses. the reduction in egg laying is proportional to the dose of exposure and was found to be about twice higher in females of ... | 1999 | 10695811 |
| 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 |
| 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 |
| 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 |
| 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 |