Publications
Title | Abstract | Year Filter | PMID(sorted descending) Filter |
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the role of promastigote secretory gel in the origin and transmission of the infective stage of leishmania mexicana by the sandfly lutzomyia longipalpis. | transmission of leishmaniasis is effected by a specific developmental stage, the metacyclic promastigote. the precursors of metacyclic promastigotes were a distinct subpopulation of parasites, identified for the first time as a new stage in the life-cycle and named leptomonad promastigotes. microdissection of infected sandflies into 4 midgut regions and foregut allowed precursor-product relationships to be established for amastigote-procyclic promastigote, procyclic-nectomonad promastigote, nect ... | 2002 | 12049412 |
leishmania chagasi: lipophosphoglycan characterization and binding to the midgut of the sand fly vector lutzomyia longipalpis. | during metacyclogenesis of leishmania in its sand fly vector, the parasite differentiates from a noninfective, procyclic form to an infective, metacyclic form, a process characterized by morphological changes of the parasite and also biochemical transformations in its major surface lipophosphoglycan (lpg). this glycoconjugate is polymorphic among species with variations in sugars that branch off the conserved gal(beta 1,4)man(alpha 1)-po(4) backbone of repeat units and the oligosaccharide cap. l ... | 2002 | 12034455 |
canine visceral leishmaniasis: dog infectivity to sand flies from non-endemic areas. | canine visceral leishmaniasis (vl), caused by leishmania infantum (leishmania chagasi in the new world), is a zoonotic, endemic disease in western europe and latin america. the potential spreading to new regions was suggested by the appearance of canine vl among foxhounds in the us. although the sand fly vectors in the major foci of transmission have been described, no information exists on other sand flies that could propagate the infection outside endemic areas. we evaluated the capacity of lu ... | 2002 | 12002643 |
distribution of putative male sex pheromones among lutzomyia sandflies (diptera: psychodidae). | male lutzomyia longipalpis produce terpene sex pheromones in glandular tissue underlying the cuticle. the pheromones are transmitted to the surface via cuticle-lined ducts (measuring 0.25 microm in diameter), each of which reaches the surface in the centre of a papule (measuring 3-3.5 microm in diameter). similar papules, in a range of shapes but all characterized by the presence of a central pore and absence of macroserae, occur in some other species of sandfly. the aim of the present study was ... | 2002 | 11989537 |
the d7 family of salivary proteins in blood sucking diptera. | the d7 subfamily of salivary proteins is widespread in blood sucking diptera and belongs to the superfamily of pheromone/odourant binding proteins. although d7 proteins are among the most abundant salivary proteins in adult female mosquitoes and sand flies, their role in blood feeding remains elusive. in the present work we report the sequence of seventeen novel d7 proteins, and propose an evolutionary scenario for the appearance of the several forms of this protein, based on a total of twenty-o ... | 2002 | 11966880 |
copulation songs in three siblings of lutzomyia longipalpis (diptera: psychodidae). | we present the results of recording male courtship songs of the sandfly lutzomyia longipalpis. the striking differences in the songs from 3 brazilian populations of this sandfly with 3 distinct male pheromones support the 3 sibling species previously proposed based on this characteristic. | 2006 | 11925981 |
external morphology of sensory structures of fourth instar larvae of neotropical species of phlebotomine sand flies (diptera: psychodidae) under scanning electron microscopy. | in the present study, some morphological structures of antennae, maxillary palps and caudal setae of fourth instar larvae of laboratory-reared phlebotomine sand flies (lutzomyia longipalpis, l. migonei, l. evandroi, l. lenti, l. sericea, l. whitmani and l. intermedia) of the state of ceará, brazil, were examined under scanning electron microscopy. the antennal structures exhibited considerable variation in the morphology and position. a prominent digitiform distal segment has been observed only ... | 2001 | 11784930 |
wing geometry as a tool for studying the lutzomyia longipalpis (diptera: psychodidae) complex. | toro toro (t) and yungas (y) have been described as genetically well differentiated populations of the lutzomyia longipalpis (lutz & neiva, 1912) complex in bolivia. here we use geometric morphometrics to compare samples from these populations and new populations (bolivia and nicaragua), representing distant geographical origins, qualitative morphological variation ("one-spot" or "two-spots" phenotypes), ecologically distinct traits (peridomestic and silvatic populations), and possibly different ... | 2001 | 11784928 |
phlebotomine sand flies in the state of piauí, brazil (diptera: psychodidae: phlebotominae). | in 1997, 1998 and 1999 we performed several captures in the state of piauí, in the counties of barro duro, campo maior, castelo, floriano, picos, são raimundo nonato and teresina. we used cdc light traps inside houses, in a primary forest and in one cave. seventeen species were collected being lutzomyia longipalpis, lutzomyia samueli, lutzomyia whitmani and lutzomyia lenti the most captured species. the genus brumptomyia, l. whitmani, lutzomyia sordellii, lutzomyia carmelinoi, lutzomyia termitop ... | 2001 | 11784927 |
the biological function of sand fly and leishmania glycosidases. | this is a summary of the recent work on some glycosidases of sand flies and their leishmania parasites. glycosidases catalyze the hydrolysis of complex sugar subunits of polysaccharides into simple sugars. leishmania major parasites secrete chitinase and n-acetylglucosaminase, which enables them to survive in the gut of the sand fly and are important in facilitating their transmission by the phlebotomine sand fly phlebotomus papatasi. these enzymes are found in a wide range of trypanosomatids an ... | 2001 | 11770110 |
lutzomyia pseudolongipalpis: the first new species within the longipalpis (diptera: psychodidae: phlebotominae) complex from la rinconada, curarigua, lara state, venezuela. | lutzomyia pseudolongipalpis, the first new sand fly species within the longipalpis complex, is described based on females and males from la rinconada, curarigua, lara state, venezuela. similar to lutzomyia longipalpis sensu lato, females of the new species show spermathecae with 8-10 annulations and cibarial armature with 8-12 horizontal teeth. however, l. pseudolongipalpis females show conspicuous vertical cibarial teeth, large stipites and wing vein sections, round cerci, and short and broad v ... | 2001 | 11761375 |
hepatitis c virus core and envelope proteins do not suppress the host's ability to clear a hepatic viral infection. | several hepatitis c virus (hcv) proteins have been shown in vitro to interact with host cellular components that are involved in immune regulation. however, there is a paucity of data supporting the relevance of these observations to the in vivo situation. to test the hypothesis that such an interaction suppresses immune responses, we studied a line of transgenic c57bl/6 mice that express the hcv core and envelope proteins in the liver. the potential effects of these proteins on the hepatic immu ... | 2001 | 11711589 |
development of lutzomyia intermedia and lutzomyia longipalpis (diptera: psychodidae: phlebotominae) larvae in different diets. | the objective of this research was to evaluate, in laboratory, the development of lutzomyia intermedia and lutzomyia longipalpis (diptera: psychodidae: phlebotominae) larvae, vectors of leishmaniasis in brazil, in the following diets: industrialized food for rabbits, dogs, hamsters and aquarium fishes, besides liver powder, cooked lettuce, wheat germ, beer yeast, oat, wheat bran and a diet denominated aged food. except wheat bran for l. intermedia, all diets provided adequate development for bot ... | 2002 | 11706567 |
dissociation between vasodilation and leishmania infection-enhancing effects of sand fly saliva and maxadilan. | in this study, the ability of maxadilan and lutzomyia longipalpis salivary gland lysate to enhance the infection of cba mice by leishmania major and of balb/c mice by l. braziliensis was tested. no difference was observed between sizes of lesion in cba mice infected with l. major and treated or not with salivary gland lysate or maxadilan, although they were injected in concentrations that induced cutaneous vasodilation. although parasites were more frequently observed in foot pads and spleens of ... | 2001 | 11685268 |
ultrastructure of endocrine cells from the abdominal midgut epithelium of lutzomyia longipalpis (diptera: psychodidae). | transmission electron microscopy (tem) was used to study two types of endocrine cells front the midgut of adult female luttzomyia longipalpis (lutz & neiva). endocrine cells rarely have been observed in nematocera, even using tem, and were present in small numbers dispersed among the monolayer of midgut digestive epithelial cells. triangular shaped "closed" cells were observed along the basement membrane, bounded on each side by digestive cells; these cells closed distally before reaching the ep ... | 2001 | 11580051 |
[phlebotomine sand flies in the state of tocantins, brazil (diptera: psychodidae)]. | between 1997-1998, the authors carried out sporadic collection of sand flies in the municipalities of paraíso de tocantins, monte do carmo, porto nacional and monte santo all in the tocantins state of northern brazil. human bait was used in monte santo and a battery operated light trap in other municipalities. the ecotypes chosen for the traps were in the peridomiciles, inside the houses, in the forest and the orchard. we identified 2,677 sand flies, belonging to 32 species. the most abundant sp ... | 2001 | 11562724 |
deltamethrin-impregnated dog collars have a potent anti-feeding and insecticidal effect on lutzomyia longipalpis and lutzomyia migonei. | deltamethrin-impregnated pvc dog collars were tested to assess if they were effective in protecting dogs from sand fly bites of lutzomyia longipalpis and lu. migonei. a protective effect against old world species phlebotomus perniciosus was demonstrated before. four dogs wearing deltamethrin collars and three dogs wearing untreated collars (not impregnated with deltamethrin) were kept in separate kennels for over eight months in a village on the outskirts of fortaleza in ceará, brazil. periodica ... | 2001 | 11562713 |
leishmaniasis vaccination: targeting the source of infection. | 2001 | 11489957 | |
toward a defined anti-leishmania vaccine targeting vector antigens: characterization of a protective salivary protein. | leishmania parasites are transmitted to their vertebrate hosts by infected phlebotomine sand fly bites. sand fly saliva is known to enhance leishmania infection, while immunity to the saliva protects against infection as determined by coinoculation of parasites with vector salivary gland homogenates (sghs) or by infected sand fly bites (kamhawi, s., y. belkaid, g. modi, e. rowton, and d. sacks. 2000. science. 290:1351-1354). we have now characterized nine salivary proteins of phlebotomus papatas ... | 2001 | 11489952 |
heterogeneity of wild leishmania major isolates in experimental murine pathogenicity and specific immune response. | virulence variability was investigated by analyzing the experimental pathogenicity of 19 leishmania major strains in susceptible balb/c mice. twelve strains were isolated from tunisian patients with zoonotic cutaneous leishmaniasis; seven strains were isolated in syria (n = 1), saudi arabia (n = 2), jordan (n = 2), or israel (n = 2). balb/c mice were injected in the hind footpad with 2 x 10(6) amastigotes of the various isolates, and lesion progression was recorded weekly for 9 weeks. interleuki ... | 2001 | 11447167 |
canine visceral leishmaniasis in colombia: relationship between clinical and parasitologic status and infectivity for sand flies. | we studied the reservoir competency of canines with distinct clinical presentations of leishmania chagasi infection. the parasitologic status of asymptomatic and symptomatic dogs was determined by standard culture methods infectivity was assessed by multiple xenodiagnoses with lutzomyia longipalpis, over a period of 2-11 months. asymptomatic dogs were non-infective (0 of 5) while 2 of 7 oligosymptomatic dogs infected l longipalpis, transmitting the parasites at low rates (range 0.9-5.2% of engor ... | 2001 | 11442205 |
[lutzomyia longipalpis and leishmaniasis visceral in argentina]. | lutzomyia longipalpis is reported for the second time after 50 years in misiones province, argentina. this insect is the vector of leishmania (l.) chagasi, visceral leishmaniasis' parasite. the literature concerning the 16 visceral leishmaniasis cases in the country is reviewed. the cases were reported from salta, jujuy, santiago del estero and chaco provinces. based on the clinical and entomo-epidemiological data two alternative hypotheses were evaluated: a) visceral leishmaniasis in argentina ... | 2001 | 11374140 |
new molecular markers for phlebotomine sand flies. | using degenerate-primers pcr we isolated and sequenced fragments from the sand fly lutzomyia longipalpis homologous to two behavioural genes in drosophila, cacophony and period. in addition we identified a number of other gene fragments that show homology to genes previously cloned in drosophila. a codon usage table for l. longipalpis based on these and other genes was calculated. these new molecular markers will be useful in population genetics and evolutionary studies in phlebotomine sand flie ... | 2001 | 11334955 |
courtship song genes and speciation in sand flies. | lutzomyia longipalpis (lutz & neiva, 1912) (diptera: psychodidae: phlebotominae) is a vector of visceral leishmaniasis in the americas and it might represent a complex of sibling species. reproductive isolation between closely related species often involves differences in courtship behaviour. cacophony (cac) and period (per) are two drosophila genes that control features of the "lovesong" males produce during courtship that has been implicated in the sexual isolation between closely related spec ... | 2001 | 11313653 |
effect of lutzomyia whitmani (diptera: psychodidae) salivary gland lysates on leishmania (viannia) braziliensis infection in balb/c mice. | previous reports showed that lutzomyia longipalpis saliva exacerbate leishmania braziliensis infection in mice. the sand fly lu. whitmani is one of the vectors of l. (viannia) braziliensis (lvb), a causative agent of cutaneous leishmaniasis in the state of ceará, brazil. to determine whether saliva of lu. whitmani could increase the infectivity of lvb in mice, we inoculated groups of balb/c mice with lvb promastigotes in the presence or absence of the salivary glands lysate from lu. whitmani. we ... | 2001 | 11313642 |
the phlebotominae sand fly (diptera: psychodidae) fauna of two atlantic rain forest reserves in the state of rio de janeiro, brazil. | during two consecutive years, studies on the sand fly fauna in poço das antas and fazenda bom retiro, two atlantic rain forest reserves from the state of rio de janeiro, were performed using shannon traps, cdc light traps and human bait collections. eleven species were identified; lutzomyia longipalpis, l. migonei, l. edwardsi, l. intermedia, l. whitmani, l. fischeri, l. shannoni, l. ayrozai, l. hirsuta, l. monticola and l. misionensis (first occurrence in the state of rio de janeiro). l. interm ... | 2001 | 11313637 |
the invertebrate growth factor/cecr1 subfamily of adenosine deaminase proteins. | adenosine deaminase (ada) catalyzes the hydrolysis of adenosine to inosine. its lack determines severe combined immunodeficiency in mammals, possibly due to accumulation of extracellular adenosine, which induces apoptosis in lymphocytes (franco et al., 1998). thus, presence of normal levels of ada leads to normal growth and proliferation of lymphocytes. several vertebrate and microbial ada amino-acid sequences are known, with substantial similarity to each other. on the other hand, there are inv ... | 2001 | 11311551 |
involvement of pacap receptor in primary afferent fibre-evoked responses of ventral roots in the neonatal rat spinal cord. | the role of pacap receptor in nociceptive transmission was investigated in vitro using maxadilan, a pacap receptor selective agonist and max.d.4, a pacap receptor selective antagonist. potentials, from a ventral root (l3 - l5) of an isolated spinal cord preparation or a spinal cord - saphenous nerve - skin preparation from 0 - 3-day-old rats, were recorded extracellularly. in the isolated spinal cord preparation, single shock stimulation of a dorsal root at c-fibre strength induced a slow depola ... | 2001 | 11309249 |
human immune response to sand fly salivary gland antigens: a useful epidemiological marker? | antibody (igg) responses to salivary gland homogenate and to a recombinant salivary protein from the sand fly lutzomyia longipalpis were investigated using sera from children living in an endemic area of visceral leishmaniasis in brazil. we classified children into four groups according to their responses to leishmania antigen: (group i) positive serology and positive delayed type hypersensitivity (dth), (group ii) positive serology and negative dth, (group iii) negative serology and positive dt ... | 2000 | 11304066 |
a possible role of bats as a blood source for the leishmania vector lutzomyia longipalpis (diptera: psychodidae). | some evidence suggests that bats may provide an alternative blood source for lutzomyia longipalpis, the main vector of american visceral leishmaniasis. feeding trials were conducted to determine whether l. longipalpis feeds on captive bats. the high feeding success indicated that l. longipalpis is capable of feeding on at least four species of bats. implications for the epidemiology of leishmaniases are discussed. | 2000 | 11304062 |
characterization of constitutive and putative differentially expressed mrnas by means of expressed sequence tags, differential display reverse transcriptase-pcr and randomly amplified polymorphic dna-pcr from the sand fly vector lutzomyia longipalpis. | molecular studies of insect disease vectors are of paramount importance for understanding parasite-vector relationship. advances in this area have led to important findings regarding changes in vectors' physiology upon blood feeding and parasite infection. mechanisms for interfering with the vectorial capacity of insects responsible for the transmission of diseases such as malaria, chagas disease and dengue fever are being devised with the ultimate goal of developing transgenic insects. a primar ... | 2001 | 11285481 |
gene flow between natural and domestic populations of lutzomyia longipalpis (diptera: psychodidae) in a restricted focus of american visceral leishmaniasis in venezuela. | the epidemiology of the visceral leishmaniasis in the americas is associated with both a natural and a domestic cycle. the existence of reproductively isolated populations of lutzomyia longipalpis (lutz & neiva), and the scarcity of records of this species from natural habitats in areas where it has been associated with domestic habitats indicated that natural populations could be genetically distinct from domestic ones. therefore, we compared the genetic structure and estimated the gene flow be ... | 2001 | 11268683 |
[digestive tract microbiota in female lutzomyia longipalpis (lutz & neiva, 1912) (diptera: psychodidae) from colonies feeding on blood meal and sucrose plus blood meal]. | there are very few reports on the microbiota of the digestive tract of sand flies, an important omission considering that blood is not the only meal ingested. male and female sand flies obtain sugar meals from several sources, thereby increasing their chance of infection with microorganisms. chances of contamination are higher when insects are bred in the laboratory, and this may affect the development of leishmania spp. from the digestive tract of 300 sand fly females separated in two groups we ... | 2001 | 11241946 |
[hourly frequency and seasonality of lutzomyia longipalpis (diptera: psychodidae: phlebotominae) on são luís island, maranhão, brazil]. | this article presents the hourly and seasonal distribution of the lutzomyia longipalpis sand fly captured on são luís island, maranhão state. a total of 11,200 specimens were captured during monthly use of cdc light traps indoors and in animal sheds, between 6:00 pm and 6:00 am, in 1996 and 1997. the sand fly behaved as an annual species, with a high frequency year-round, while it was most abundant during the rainy season (57.2%) as compared to the dry season (42.8%). the highest frequencies dur ... | 2001 | 11241945 |
influence of lysates of the salivary glands of lutzomyia longipalpis on the development of a leishmania-major-like parasite in the skin of the golden hamster. | twelve years ago, some mice inoculated with leishmania major were found to develop larger lesions, containing more amastigotes, if the inoculum used to infect them contained a lysate of salivary glands from lutzomyia longipalpis than if no lysate was included. in the present study, outbred golden hamsters (mesocricetus auratus) were each inoculated in a footpad with 10(4), 10(5), 10(6) or 10(7) stationary-phase promastigotes of a leishmania-major-like parasite (mhom/br/71/bh49). some of the inoc ... | 2001 | 11235554 |
[first record of finding lutzomyia longipalpis (lutz & neiva, 1912) in the urban area of brazil]. | this is a report of the first finding of visceral leishmaniasis' vector lutzomyia longipalpis in the urban area of campo grande, state of mato grosso do sul. the importance of this finding regarding the transmission of the disease in this area is discussed. | 2000 | 11175612 |
speciation and population structure in the morphospecies lutzomyia longipalpis (lutz & neiva) as derived from the mitochondrial nd4 gene. | recent studies have suggested that the phlebotomine sand fly lutzomyia longipalpis (diptera: psychodidae), the principal vector of visceral leishmaniasis in the neotropics, may consist of several allopatric sibling species. phylogenetic and population genetic analyses of nucleotide variation in a 618-bp fragment of the mitochondrial nd4 gene were carried out on specimens of lu. longipalpis from several locations in central and south america. the analyses were concordant with previous findings, i ... | 2001 | 11161745 |
the salivary apyrase of the blood-sucking sand fly phlebotomus papatasi belongs to the novel cimex family of apyrases. | apyrases are enzymes that hydrolyze nucleotide di- and triphosphates to orthophosphate and mononucleotides. at least two families of enzymes, belonging to the 5'-nucleotidase and to the actin/heat shock 70/sugar kinase superfamily, have evolved independently to serve the apyrase reaction. both families require either ca(2+) or mg(2+) for their action. a novel apyrase enzyme sequence, with no homology to any other known protein sequence, was found recently in the salivary glands of the hematophag ... | 2001 | 11136609 |
sensilla on the terminalia of lutzomyia spp. (diptera: psychodidae) sand flies. | sensilla on the male terminalia of four different species of sand flies (diptera: psychodidae) are described. two species belonged to the same species complex: lutzomyia longipalpis (lutz & neiva) and l. cruzi (mangabeira). other brazilian species complex was represented by l. lenti (mangabeira) and l. carmelinoi (ryan, fraiha, lainson & shaw). approximately 5-15 sensilla were found on the initial part of the styles of all species. structurally, the sensory organs were similar to small coeloconi ... | 2000 | 11126541 |
expression of heterologous promoters in lutzomyia longipalpis and phlebotomus papatasi (diptera: psychodidae) cell lines. | to establish a transient expression system for genes introduced into sand fly cell lines, we tested the expression of the luciferase reporter gene under control of different promoters. towards this end, we lipofected cell lines obtained from new and old world sand flies, ll-5 from lutzomyia longipalpis lutz & neiva and pp-9 from phlebotomus papatasi scopoli, respectively. the relative levels of luciferase expression were studied under control of drosophila melanogaster meigen heat shock protein ... | 2000 | 11126533 |
salivary proteins and glycoproteins in phlebotomine sandflies of various species, sex and age. | salivary gland proteins were studied in sandflies (diptera: psychodidae: phlebotominae) by electrophoretic techniques. in phlebotomus duboscqi neveu-lemaire the protein concentration was about 30 times higher in females than in males. sds page revealed eight major bands of 29-62 kda in salivary gland extracts (sge) from females, whereas only one band of 57kda was detected in males. the number of protein components in sge gradually increased with the age of females. in p. papatasi (scopoli) the t ... | 2000 | 11016431 |
simulium vittatum (diptera: simuliidae) and lutzomyia longipalpis (diptera: psychodidae) salivary gland hyaluronidase activity. | hyaluronidase activity in the salivary gland homogenates of simulium vittatum (zetterstedt) is described, and its optimal ph determined. salivary activity was reduced significantly after a blood meal, indicating that it was secreted after blood feeding. phlebotomus papatasi (scopoli) also exhibited salivary hyaluronidase activity. these results indicate that hematophagous pool-feeding insects may secrete this enzyme to help the spread of salivary antihemostatic agents in the vicinity of the feed ... | 2000 | 11004788 |
posterior spiracles of fourth instar larvae of four species of phlebotomine sand flies (diptera: psychodidae) under scanning electron microscopy. | in the present study, posterior spiracles of laboratory-reared fourth instar larvae of lutzomyia longipalpis, l. migonei, l. lenti, and l. whitmani (diptera: psychodidae) of the state of ceará, brazil, were examined under scanning electron microscopy. the number of papillae of spiracles examined varied according to the species examined, but no intraspecific differences were found. the importance of this structure to sand fly larva identification and phylogeny is commented. | 2003 | 10998217 |
"the salivary 5'-nucleotidase/phosphodiesterase of the hematophagus sand fly, lutzomyia longipalpis" by jose m.c. ribeiro, edgar d. rowton and rosane charlab. insect biochemistry and molecular biology 30(4) pp.279-285 | 2000 | 10989299 | |
[prevalence of microbiota in the digestive tract of wild females of lutzomyia longipalpis lutz & neiva, 1912) (diptera: psychodidae)]. | we dissected the digestive tract of 245 females in pools of 35 flies forming 7 groups. these flies were lutzomyia longipalpis originating from lapinha cave, lagoa santa, minas gerais. out of the 8 species of bacteria isolated there was a predominancy of gram negative bacterias (gnb) in the group of non-fermenters of sugar belonging to the following species: acinetobacter lwoffii, stenotrophomonas maltophilia, pseudomonas putida and flavimonas orizihabitans. the group of gnb fermenters were: ente ... | 2000 | 10967602 |
competence of the human host as a reservoir for leishmania chagasi. | the failure of control programs for visceral leishmaniasis (vl) that depend on elimination of infected dogs suggests that other reservoir hosts may participate in the transmission cycle. to determine whether persons infected with leishmania chagasi can infect the vector sand fly, laboratory-reared lutzomyia longipalpis were allowed to feed on brazilian subjects with active, cured, and asymptomatic vl and on asymptomatic residents of houses of persons with active vl. of 3747 insects that had fed, ... | 2000 | 10950806 |
evolution of lesion formation, parasitic load, immune response, and reservoir potential in c57bl/6 mice following high- and low-dose challenge with leishmania major. | a model of cutaneous leishmaniasis using 10(2) leishmania major metacyclic promastigotes inoculated into the footpads of genetically resistant c57bl/6 mice was studied in order to more accurately reproduce the evolution of lesion formation and the kinetics of parasite growth and immune response as they might occur in naturally exposed reservoirs and in human hosts. in contrast to the more conventional experimental model employing 10(6) metacyclic promastigotes, in which the rapid development of ... | 2000 | 10948141 |
correlated morphologic and genetic diversity among lutzomyia longipalpis (diptera: psychodidae) collections in venezuela. | diversity among lutzomyia longipalpis populations in venezuela was characterized using 2 methods: larval mouthpart morphology-morphometry and isoenzyme electrophoresis. analysis of the results suggested the presence of 2 morpho-genotypes. the mentum, maxillary comb, mandibular ventral teeth, and adenylate kinase and hexokinase enzyme-encoding loci suggested that a population from the northwestern coriano system (curarigua) is a distinct lineage within the l. longipalpis complex. three widely sep ... | 2000 | 10901644 |
molecular and biologic characterization of leishmania parasites implicated in an epidemic outbreak in northwestern argentina. | leishmania (viannia) braziliensis and its variants were implicated in the epidemic outbreak of mucocutaneous leishmaniasis that occurred in salta, northwestern argentina, in 1985. a total of 24 suspected, untreated cases were evaluated clinically and parasitologically. four of five stable isolates were consistent with the reference strain of l. (v.) braziliensis as determined by monoclonal antibodies and indirect immunofluorescence or radioimmunobinding assays. zymodeme analysis in agarose gels ... | 2000 | 10894479 |
sibling species in the llutzomyia longipalpis complex differ in levels of mrna expression for the salivary peptide, maxadilan. | maxadilan is a small ( approximately 7 kda) protein found in the saliva of sand fly species in the lutzomyia longipalpis complex, vectors of the parasite causing visceral leishmaniasis, leishmania chagasi. it is a potent vasodilator and also has immunomodulatory affects. maxadilan recovered from different sibling species of the lu. longipalpis complex differ in amino acid content by as much as 23%, however all variants possess equivalent vasodilatory activity. therefore, the dramatic differences ... | 2000 | 10886415 |
the salivary adenosine deaminase from the sand fly lutzomyia longipalpis. | in the process of sequencing a subtracted cdna library from the salivary glands of the sand fly lutzomyia longipalpis, we identified a cdna with similarities to gene products of the adenosine deaminase family. prompted by this cdna finding, we detected adenosine deaminase activity at levels of 1 u/mg protein in salivary gland homogenates. the activity was significantly reduced following a blood meal indicating its apparent secretory fate. the native enzyme has a k(m) of approximately 10 microm, ... | 2000 | 10864517 |
delayed-type hypersensitivity to phlebotomus papatasi sand fly bite: an adaptive response induced by the fly? | the saliva of bloodsucking arthropods contains a large array of pharmacologically active compounds that assist hematophagy. arthropod saliva is also responsible for causing uncomfortable allergic responses in its vertebrate hosts. in this article, we investigate whether the sand fly phlebotomus papatasi, known to produce a strong delayed-type hypersensitivity (dth) in humans, could benefit from, and possibly adaptively induce, this response in their vertebrate hosts. in this study, we show that ... | 2000 | 10841567 |
adaptive female choice for middle-aged mates in a lekking sandfly. | most theoretical models of age-related mate choice predict that females should prefer older males because they have proven survival ability. an alternative view is that older males represent inferior mates because of negative genetic correlations between early and late fitness components, or because older males have traded off longevity against other fitness components, have accumulated deleterious germ-line mutations, or are less well adapted to current conditions than more recently born indivi ... | 0 | 10821613 |
studies on populations of lutzomyia longipalpis (lutz & neiva, 1912) (diptera: psychodidae: phlebotominae) in brazil. | studies were performed on five brazilian populations of lutzomyia longipalpis: salvaterra (pa), são josé do ribamar (ma), canindé (ce), natal (rn) and gruta da lapinha, lagoa santa (mg). no morphological differences were observed that could distinguish between these populations. homogeneity tests showed that the allopatric populations display a certain heterogeneity and that the sympatric populations, with different patterns of spots, are homogeneous. the student-newman-keuls test, represented b ... | 2000 | 10800188 |
adenosine, amp, and protein phosphatase activity in sandfly saliva. | as they probe the skin for blood, sand flies inject saliva that prevents hemostasis. sand fly saliva also promotes leishmaniasis by suppressing immunologic functions of macrophages. saliva of phlebotomus papatasi, the vector of old world cutaneous leishmaniasis, contains adenosine and amp. we show that ph. papatasi saliva as well as pure adenosine down-regulate the expression of the inducible nitric oxide (no) synthase gene in activated macrophages. in addition ph. papatasi, but not lutzomyia lo ... | 2000 | 10761741 |
[sandflies (diptera, psychodidae) in a secondary forest area in the paco do lumiar city, maranhao, brazil: a leishmaniasis transmission area]. | this paper analyzes the wealth of species, relative abundance, seasonal fluctuation, and nocturnal activity of sandflies. the field survey was conducted in a "capoeira" (secondary forest) area in the county of paço do lumiar, maranhão, where cutaneous and transmission of visceral leishmaniasis frequently occurs. sandflies were captured by cdc-type light traps from 6:00 pm to 6:00 am, once a month, from march 1997 to february 1998. a total of 489 specimens were collected (251 males and 238 female ... | 2000 | 10738174 |
aspects related to productivity for four generations of a lutzomyia longipalpis laboratory colony. | a closed colony of lutzomyia longipalpis was established with specimens collected in the raposa - serra do sol indian reservoir, one of the main foci of visceral leishmaniasis in the state of roraima, brazil. biological observations were made on four generations of a l. longipalpis colony with emphasis on productivity. aspects studied were the number of laid and retained eggs, and the number of adults (male and female) per generation. during the four generations the percentage of engorged female ... | 2006 | 10733749 |
the salivary 5'-nucleotidase/phosphodiesterase of the hematophagus sand fly, lutzomyia longipalpis [corrected]. | salivary gland homogenates from adult female lutzomyia longipalpis sand flies contain large amounts of 5'-nucleotidase and phosphodiesterase activities. phosphodiesterase activity was found to be associated with 5'-nucleotidase in several independent experiments: (i) it coelutes with 5'-nucleotidase on a molecular sieving column, (ii) it coelutes with 5'-nucleotidase on a chromatofocusing column, and (iii) it has the same thermal inactivation kinetics as the 5'-nucleotidase activity. additionall ... | 2000 | 10727894 |
salivary amylase activity of the phlebotomine sand fly, lutzomyia longipalpis. | both male and female adult stages of the sand fly lutzomyia longipalpis have detectable amylase activity in their salivary glands, as indicated by formation of p-nitrophenyl-alpha-d-maltoside from p-nitrophenyl-alpha-d-octoside and by hydrolysis of 4-nitrophenyl-alpha-d-maltoheptaoside-4,6,-o-ethylidene. no salivary alpha-glucosidase was detected. amylase activity was also found in the crop and midgut of female flies, although in a smaller amount. salivary amylase is significantly reduced from t ... | 2000 | 10727893 |
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 |
occurrence of sibling species of lutzomyia longipalpis (diptera: psychodidae) in venezuela: first evidence from reproductively isolated sympatric populations. | the delimitation of cryptic species within the main vector of the american visceral leishmaniasis, lutzomyia longipalpis, remains a topic of controversy. an analysis of genetic variability based on 8 enzymatic loci revealed fixed differences in 2 diagnostic loci, adenylate kinase (ak) and hexokinase (hk), between sympatric and allopatric populations at 4 localities in venezuela. the absence of heterozygotes for these 2 loci within 1 locality indicates, for the first time, the presence of 2 sympa ... | 1999 | 10674686 |
epidemiologic aspects of american visceral leishmaniasis in an endemic focus in eastern venezuela. | an endemic focus of american visceral leishmaniasis (avl) in eastern venezuela has been evaluated in terms of patients (n = 48), immunologic reactivity to leishmania in household contacts (n = 187) and neighborhood controls (n = 170), detection of leishmania (l. donovani complex) in dogs and wild animals by the polymerase chain reaction (pcr) and characteristics of the sandfly population. the male:female ratio of patients was 1.18:1; 89.6% were < or =12 years old. serologic reactivity was signif ... | 1999 | 10674675 |
maxadilan interacts with receptors for pituitary adenylyl cyclase activating peptide in human sh-sy5y and sk-n-mc neuroblastoma cells. | receptors for pituitary adenylyl cyclase activating peptide (pacap) have been identified in human sh-sy5y neuroblastoma cells with pacap being 1000-fold more potent than vasoactive intestinal peptide (vip) in [(125)i]pacap binding inhibition and stimulation of camp accumulation. maxadilan, a vasodilator peptide from the salivary gland of the sand fly lutzomyia longipalpis also specifically bound to sh-sy5y cells, and was equipotent to pacap in [(125)i]pacap and [(125)i]maxadilan binding inhibiti ... | 1999 | 10657479 |
establishment and characterization of a new continuous cell line from lutzomyia longipalpis (diptera: psychodidae) and its susceptibility to infections with arboviruses and leishmania chagasi. | embryonic tissue explants of the sand fly lutzomyia longipalpis (lutz & neiva 1912) the main vector of leishmania chagasi (cunha and chagas), were used to obtain a continuous cell line (lulo). the tissues were seeded in mm/vp12 medium and these were incubated at 28 masculinec. the first subculture was obtained 45 days after explanting and 96 passages have been made to date. lulo is composed of epithelioid cells, showed a 0.04 generations/hour exponential growth rate and population doubling time ... | 2000 | 10656714 |
toward an understanding of the biochemical and pharmacological complexity of the saliva of a hematophagous sand fly lutzomyia longipalpis. | the saliva of blood-sucking arthropods contains powerful pharmacologically active substances and may be a vaccine target against some vector-borne diseases. subtractive cloning combined with biochemical approaches was used to discover activities in the salivary glands of the hematophagous fly lutzomyia longipalpis. sequences of nine full-length cdna clones were obtained, five of which are possibly associated with blood-meal acquisition, each having cdna similarity to: (i) the bed bug cimex lectu ... | 1999 | 10611354 |
the status of the lutzomyia longipalpis species complex and possible implications for leishmania transmission. | the sand fly lutzomyia longipalpis sensu latu has been identified as the principal vector of american visceral leishmaniasis, a potentially fatal disease that primarily affects children in several countries of south and central america. over the past several years increases have occurred both in the number of reported cases and the population at risk: approximately 1.6 million people reside in highly endemic areas with 16,000 cases reported annually. several studies have attempted to relate the ... | 1999 | 10585647 |
filamentous proteophosphoglycan secreted by leishmania promastigotes forms gel-like three-dimensional networks that obstruct the digestive tract of infected sandfly vectors. | development of leishmania parasites in the digestive tract of their sandfly vectors involves several morphological transformations from the intracellular mammalian amastigote via a succession of free and gut wall-attached promastigote stages to the infective metacyclic promastigotes. at the foregut midgut transition of leishmania-infected sandflies a gel-like plug of unknown origin and composition is formed, which contains high numbers of parasites, that occludes the gut lumen and which may be r ... | 1999 | 10569240 |
[sandflies (diptera, psychodidae) from an endemic leishmaniasis area in the cerrado region of the state of maranhão, brazil]. | this article presents a list of ten sandfly species from the genus lutzomyia frança, 1924 found in the counties of aldeias altas, capinzal do norte, caxias, codó, coelho neto, timbiras, timon and tuntum in northeastern maranhão, brazil. presence of sandflies was associated with cases of visceral and cutaneous leishmaniasis. some 377 specimens were captured indoors with cdc light traps and 1491 specimens in the peridomicile. the species were: lutzomyia cortelezii, lutzomyia evandroi, lutzomyia go ... | 1999 | 10502159 |
density of sand flies (diptera: psychodidae) in domestic and wild animal shelters in an area of visceral leishmaniasis in the state of rio grande do norte, brazil. | the objective of the present study was to determine the association of sand flies with the presence of domestic and wild animals in the peridomiciliary area. the sand flies were collected using direct aspiration and cdc light traps placed in animal shelters. the results suggest that different sand flies species have different behavioral characteristics in an apparent preference for animal baits and that lutzomyia longipalpis and lu. evandroi were the most eclectic species regarding their biotope ... | 1999 | 10445997 |
breeding structure of the sand fly lutzomyia longipalpis (lutz & neiva) in brazil. | eleven populations of lutzomyia longipalpis (lutz & neiva), the sand fly vector of leishmania chagasi, from different areas of brazil were analyzed for genetic variation at 16 enzyme loci. in this region, the prevalence of visceral leishmaniasis (vl) caused by l. chagasi is spotty and reproductive isolation among populations of lu. longipalpis has been reported. it is thought that morphologically similar cryptic species with varying vectorial capacity may be responsible for the discontinuous dis ... | 1999 | 10432072 |
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 |
behaviour of lutzomyia longipalpis in an area of southern honduras endemic for visceral/atypical cutaneous leishmaniasis. | the predominant sandfly in las maria de pavana, choluteca, honduras, was found to be lutzomyia longipalpis, most (69%) of the 791 specimens of this species caught being male. when local lu. longipalpis were studied over 1 year (1986-1987) using cdc traps, peaks in the size of the adult population were observed in december and july, each after a period of rain. most [51% (24/47)-67% (97/144)] of the flies caught inside houses were female whereas most [55% (6/11)-56% (37/66)] of those caught outsi ... | 1998 | 10396347 |
[phlebotomus (diptera, phlebotominae) from saint luis island, maranhão gulf region, brazil]. | this study lists 32 species of sand flies, 1 of them belonging to the genus brumptomyia and 31 to the genus lutzomyia, distributed among the following subgenera: psychodopygus (6), nyssomyia (5), pressatia (3), evandromyia (2), psathyromyia (2), sciopemyia (2), lutzomyia (1), micropygomyia (1), viannamyia (1), and the groups oswaldoi (5) and migonei (3). the sand flies were captured in the wild (forest) and in peridomicile (pigpen, hen house and stable) and intradomicile (bedroom) areas from 06: ... | 1999 | 10380563 |
variation in the salivary peptide, maxadilan, from species in the lutzomyia longipalpis complex. | maxadilan is an approximately 7kda peptide that occurs in the saliva of the sand fly lutzomyia longipalpis. this peptide is a potent vasodilator and may also have immunomodulatory effects related to the pathogenesis of leishmanial infections. variation in the primary dna and inferred amino acid sequence of maxadilan is reported. differences were found within and among natural field populations as well as among sibling species. extensive amino acid sequence differentiation, up to 23%, was observe ... | 1999 | 10380110 |
metaphase karyotypes and g-banding in sandflies of the lutzomyia longipalpis complex. | mitotic metaphase chromosomes (2n = 8) from brain cells of fourth instar sandfly larvae of four geographical strains of the lutzomyia longipaplis complex were examined microscopically, with bright-field illumination, after staining by a new g-banding technique involving exposure of air-dried chromosome preparations to quinacrine and ultraviolet light. differences of g-banding and/or position of the centromere on chromosome 4 (the smallest chromosome pair) distinguished four putative sibling spec ... | 1999 | 10194752 |
genetic variability in biochemical characters of brazilian field populations of the leishmania vector, lutzomyia longipalpis (diptera: psychodidae). | the phlebotomine sand fly lutzomyia longipalpis is the insect vector of visceral leishmaniasis, a protozoan disease of increasing incidence and distribution in central and south america. electrophoretic allele frequencies of 15 enzyme loci were compared among the l. longipalpis populations selected across its distribution range in brazil. the mean heterozygosity of two colonized geographic strains (one each from colombia and brazil) were 6% and 13% respectively, with 1.6-1.9 alleles detected per ... | 1998 | 9886196 |
exponential fitness gains of rna virus populations are limited by bottleneck effects. | fitness is a parameter that quantitatively measures adaptation of a virus to a given environment. we have previously reported exponential fitness gains of large populations of vesicular stomatitis virus replicating in a constant environment (i. s. novella et al., proc. natl. acad. sci. usa 92:5841-5844, 1995). in this paper, we report that during long-term passage of such large viral populations, fitness values reached a high-fitness plateau during which stochastic fitness variations were observ ... | 1999 | 9882378 |
phlebotomus papatasi sand fly salivary gland lysate down-regulates a th1, but up-regulates a th2, response in mice infected with leishmania major. | a vertebrate host becomes infected with leishmania major when the sand fly vector injects parasites into skin along with saliva. previous studies showed that salivary gland lysate of the new world sand fly lutzomyia longipalpis markedly enhanced l. major infection in cba mice. however, l. major is an old world parasite transmitted in nature by the old world sand fly phlebotomus papatasi. here we examine the ability of p. papatasi salivary gland lysate to enhance infection (lesion size and parasi ... | 1998 | 9820534 |
genetic polymorphism of morphological and biochemical characters in a natal, brazil, population of lutzomyia longipalpis (diptera: psychodidae). | the phlebotomine sand fly, lutzomyia longipalpis, is the vector of visceral leishmaniasis in the new world. variability in its tergal spot morphology has led to conflicting interpretations of the species status of the various forms. an l. longipalpis field population from eastern brazil was found with three co-occurring morphological variations--1-spot, 2-spot, and an intermediate form. genetic profiles were established for each form. fifteen isoenzyme loci provided the data matrix for compariso ... | 1998 | 9813825 |
lutzomyia longipalpis: ph in the gut, digestive glycosidases, and some speculations upon leishmania development. | screening for digestive glycosidases in different parts of the gut and associated organs of lutzomyia longipalpis is reported. searches for the enzymes were made in blood-fed and non-blood-fed females and the enzymes were characterized as soluble or membrane-bound molecules. a total of four different activities were detected, corresponding to the following specificities: an alpha-glucosidase, an n-acetyl-beta-d-glucosaminidase, an n-acetyl-beta-d-galactosaminidase, and an alpha-l-fucosidase. the ... | 1998 | 9806865 |
a role for pheromones in mate choice in a lekking sandfly. | there is increasing evidence to suggest that pheromone-mediated communication may play an important role in mate choice in many insects. we investigated the possible role of pheromones in mate choice in the lekking sandfly, lutzomyia longipalpis, and explored whether males or females display any behavioural traits that predict patterns of male mating success. pairs of virgin males were introduced into a small mating chamber and allowed to interact for approximately 10 min prior to the introducti ... | 1998 | 9790700 |
transformation, development, and transmission of axenically cultured amastigotes of leishmania mexicana in vitro and in lutzomyia longipalpis. | axenic cultures of leishmania mexicana amastigotes were transformed to promastigotes in vitro and in vivo in lutzomyia longipalpis. in vitro, both exponential phase and stationary phase amastigotes were capable of transforming and growing as promastigotes, but exponential phase amastigotes completed this transition more quickly. in vivo, both populations were capable of establishing infections in sand flies by membrane feeding and could be transmitted to balb/c mice via bite. a variety of morpho ... | 1998 | 9749637 |
random amplified polymorphic dna (rapd) analysis of lutzomyia longipalpis laboratory populations. | the phlebotomine sand fly lutzomyia longipalpis has been incriminated as a vector of american visceral leishmaniasis, caused by leishmania chagasi. however, some evidence has been accumulated suggesting that it may exist in nature not as a single but as a species complex. our goal was to compare four laboratory reference populations of l. longipalpis from distinct geographic regions at the molecular level by rapd-pcr. we screened genomic dna for polymorphic sites by pcr amplification with decame ... | 1998 | 9713138 |
field monitoring of cypermethrin residual effect on the mortality rates of the phlebotomine sand fly lutzomyia longipalpis in the state of paraíba, brazil. | in a visceral leishmaniasis endemic locality of northeast of brasil where all settlements were treated with cypermethrin, a follow-up of lutzomyia longipalpis populations was carried out by regular collections. the residual effect of the insecticide was studied using biological assays on three different types of walls. the results showed that the insecticides had an effect on intradomiciliar lu. longipalpis populations limited to two months, and had no significant effect on peridomiciliar vector ... | 1998 | 9698867 |
morphological study of the larval spiracular system in eight lutzomyia species (diptera: psychodidae). | the morphology of the spiracles of fourth instar larva in eight sandfly species were examined by light and scanning electron microscopy. species studied were: lutzomyia longipalpis (lutz & neiva), l. ovallesi (ortiz), l. youngi feliciangeli & murillo, l. evansi (nuñez-tovar), l. trinidadensis (newstead), l. migonei (frança), l. absonodonta feliciangeli, and l. venezuelensis (floch & abonnenc). in larvae of all eight species both thoracic and abdominal spiracles are located at the top of a globul ... | 2006 | 9698846 |
genetic variation among natural and laboratory colony populations of lutzomyia longipalpis (lutz & neiva, 1912)(diptera: psychodidae) from colombia. | genetic diversity among three field populations of lutzomyia longipalpis in colombia was studied using isozyme analysis. study sites were as much as 598 km apart and included populations separated by the eastern cordillera of the andes. genetic variability among populations, estimated by heterozygosity, was within values typical for insects in general (8.1%). heterozygosity for field populations were compared with a laboratory colony from colombia (melgar colony) and were only slightly lower. th ... | 1998 | 9698845 |
prevention of cerebral vasospasm by vasodilatory peptide maxadilan following subarachnoid hemorrhage in rabbits. | maxadilan is a vasodilatory peptide isolated from the blood-feeding sand fly lutzomyia longipalpis. its vasodilatory activity, estimated by the formation of erythema on rabbit skin, is greater than those of calcitonin gene-related peptide, vasoactive intestinal polypeptide and pituitary adenylyl cyclase activating polypeptide (pacap). we have recently demonstrated that maxadilan is a specific agonist for the pacap type i receptor, which is widely distributed in brain. therefore, we were interest ... | 1998 | 9685937 |
[update on the geographical distribution and first record of lutzomyia longipalpis in an urban area in são paulo state, brazil]. | 1997 | 9629719 | |
stomodaeal valve ultrastructure in the sandfly lutzomyia longipalpis (diptera: psychodidae). | the stomodaeal valve and adjacent cardia region of the alimentary canal of the phlebotomine sandfly lutzomyia longipalpis have been studied using electron microscopy. with the scanning electron microscope (sem), numerous pit-like structures of different sizes were found in the surface of the valve of male and female flies. under the transmission electron microscope (tem), the cells adjacent to the pores were shown to have numerous mitochondria and to lack neural innervation. it is suggested that ... | 1998 | 9622365 |
salivary gland lysate from the sand fly lutzomyia longipalpis suppresses the immune response of mice to sheep red blood cells in vivo and concanavalin a in vitro. | 1998 | 9603500 | |
[phlebotomines (diptera: psychodidae) focusing visceral leishmaniasis in the state of mato grosso do sul, brazil]. | in the americas, lutzomyia longipalpis has been incriminated as the vector of visceral leishmaniasis in almost all the areas in which this disease has been reported. the notification of human cases of visceral leishmaniasis and the presence of dogs with an appearance suggestive of the disease in the country of corumbá, mato grosso do sul state, brazil, led us to undertake an entomological investigation in this area, for the purpose of identifying the phlebotomine vector. | 1997 | 9595767 |
genetic structure of local populations of lutzomyia longipalpis (diptera: psychodidae) in central colombia. | lutzomyia longipalpis (lutz & neiva), the sand fly vector of american visceral leishmaniasis in the new world tropics, has a broad but discontinuous geographical distribution from southern mexico to argentina. a baseline for population genetic structure and genetic variability for this species was obtained by analyzing 5 local, peridomestic populations at the approximate center of its distribution, the magdalena river valley of central colombia. three populations of l. longipalpis from el callej ... | 1998 | 9542350 |
genetic variability among populations of the sand fly lutzomyia (lutzomyia) longipalpis (diptera: psychodidae) from central america. | eleven central american populations of lutzomyia longipalpis (lutz & neiva) were analyzed for genetic variation at 16 enzyme loci. the aim was to study the genetic structure among populations within this region and to identify demes that may represent different sibling species. genotypic frequencies within populations agreed with hardy-weinberg expectations, indicating that there were no sympatric sibling species among these 11 populations. levels of genetic distance between pairs of populations ... | 1998 | 9538579 |
phlebotomus papatasi saliva inhibits protein phosphatase activity and nitric oxide production by murine macrophages. | leishmania parasites, transmitted by phlebotomine sand flies, are obligate intracellular parasites of macrophages. the sand fly phlebotomus papatasi is the vector of leishmania major, a causative agent of cutaneous leishmaniasis in the old world, and its saliva exacerbates parasite proliferation and lesion growth in experimental cutaneous leishmaniasis. here we show that p. papatasi saliva contains a potent inhibitor of protein phosphatase 1 and protein phosphatase 2a of murine macrophages. we f ... | 1998 | 9529078 |
sugar feeding and fluid destination control in the phlebotomine sandfly lutzomyia longipalpis (diptera: psychodidae). | sandfly feeding behaviour and destination of coloured sugar meals in the gut of lutzomyia longipalpis were investigated with particular attention to the role of the crop. sandflies were able to ingest sugar from liquid drops, microcapillaries, a slice of pear and even sugar powder. in most cases the flies adopted a 'sugar feeding mode' with raised palps. as the fruit dried, flies of both sexes fed by piercing the tissue with the proboscis. all sugar-fed flies had a full crop plus a small amount ... | 1998 | 9513934 |
susceptibility of lutzomyia longipalpis (diptera: psychodidae) to selected insecticides in an endemic focus of visceral leishmaniasis in venezuela. | a field population of lutzomyia longipalpis from la rinconada, lara state, an endemic focus of visceral leishmaniasis in venezuela, was tested for susceptibility to organochlorine (ddt 2%), carbamate (propoxur 0.01%), organophosphate (malathion 2%, fenitrothion 1%, and pirimiphos methyl 1%), and pyrethroid (deltamethrin 0.06%, lambdacyhalothrin 0.06%, and permethrin 0.2%) insecticides. susceptibility to the insecticides tested was evaluated in the field population of l. longipalpis and compared ... | 1997 | 9474559 |
the vasoactive peptide maxadilan from sand fly saliva inhibits tnf-alpha and induces il-6 by mouse macrophages through interaction with the pituitary adenylate cyclase-activating polypeptide (pacap) receptor. | maxadilan is a vasodilatory peptide encoded by a gene cloned from lutzomyia longipalpis salivary glands. in this study we investigated the effects of maxadilan on macrophage functions. maxadilan treatment of lps-stimulated balb/c macrophages inhibited tnf-alpha release but increased il-6. further, it also induced il-6 release in a dose-dependent manner from unstimulated macrophages. maxadilan increased production of pge2, and the inhibition of tnf-alpha was completely abrogated by indomethacin. ... | 1998 | 9469441 |
larval microhabitats of lutzomyia longipalpis (diptera: psychodidae) in an endemic focus of visceral leishmaniasis in colombia. | an intensive search for the larval habitats of lutzomyia longipalpis (lutz & neiva) was conducted from november 1992 to october 1993 at a small rural community in colombia where american visceral leishmaniasis is endemic. emergence traps constructed from polyvinyl chloride pipes were used to sample a variety of soil microhabitats that included edge areas of covered pigpens, cattle corrals, the base of trees, and leaf litter at sites within 40 m of a house, rocks in fields located between 50 and ... | 1997 | 9439128 |
isozymic and metric variation in the lutzomyia longipalpis complex. | male lutzomyia longipalpis of two types from bolivia were compared using isozyme electrophoresis and wing morphometry. one sample (ex chiflonkaka cave, alt. 2800 m at toro toro, charcas province, potosi department) was 'two-spot' phenotype males (i.e. tergites iii and iv with paired pale patches of pheromone glands), whereas two other locality samples (apa apa and imanaco, sud yungas province, la paz department) were one-spot male phenotype (only tergite iv with paired pale patches). multilocus ... | 1997 | 9430121 |
the sandfly lutzomyia longipalpis shows specific humoral responses to bacterial challenge. | the presence of immune molecules induced by microorganisms in the haemolymph of lutzomyia longipalpis sandflies has been investigated. injections of escherichia coli and micrococcus luteus into female sandflies induced anti-bacterial activity in the haemolymph. inhibition zone assays showed that haemolymph from e. coli and m.luteus injected sandflies differentially inhibited m.luteus growth. this differential effect was specific to m.luteus infection since anti-e.coli activity was similar in hae ... | 1997 | 9430110 |