Publications

trypanosoma rangeli interactions within the vector rhodnius prolixus: a mini review.	this article is an integrative mini review of the research on the interactions between trypanosoma rangeli and the insect vector, rhodnius prolixus. special attention is given to the interactions of these parasites with the gut environment, gut walls, with hemolymph invasion, hemocytes, hemocyte microaggregations, prophenoloxidase-activating system, superoxide, and nitric acid generation and eicosanoid pathways. we described factors affecting vectorial capacity and suggested that t. rangeli may ...	2005	16184237
structural and morphological characterization of hemozoin produced by schistosoma mansoni and rhodnius prolixus.	hemozoin (hz) is a heme crystal produced upon the digestion of hemoglobin (hb) by blood-feeding organisms as a main mechanism of heme disposal. the structure of hz consists of heme dimers bound by reciprocal iron-carboxylate interactions and stabilized by hydrogen bonds. we have recently described heme crystals in the blood fluke, schistosoma mansoni, and in the kissing bug, rhodnius prolixus. here, we characterized the structures and morphologies of the heme crystals from those two organisms an ...	2005	16229843
nitric oxide interaction with insect nitrophorins and thoughts on the electron configuration of the {feno}6 complex.	the nitrophorins are no-carrying heme proteins that are found in the saliva of two species of blood-sucking insects, the kissing bug (rhodnius prolixus) and the bedbug (cimex lectularius). in both insects the no is bound to the ferric form of the protein, which gives rise to kds in the micromolar to nanomolar range, and thus upon injection of the saliva into the tissues of the victim the no can dissociate to cause vasodilation and inhibition of platelet aggregation. the structures of the protein ...	2005	15598503
heme-assisted s-nitrosation of a proximal thiolate in a nitric oxide transport protein.	certain bloodsucking insects deliver nitric oxide (no) while feeding, to induce vasodilation and inhibit blood coagulation. we have expressed, characterized, and determined the crystal structure of the cimex lectularius (bedbug) nitrophorin, the protein responsible for no storage and delivery, to understand how the insect successfully handles this reactive molecule. surprisingly, no binds not only to the ferric nitrophorin heme, but it can also be stored as an s-nitroso (sno) conjugate of the pr ...	2005	15637157
molecular characterisation of trypanosoma rangeli strains isolated from rhodnius ecuadoriensis in peru, r. colombiensis in colombia and r. pallescens in panama, supports a co-evolutionary association between parasites and vectors.	we present data on the molecular characterisation of strains of trypanosoma rangeli isolated from naturally infected rhodnius ecuadoriensis in peru, from rhodnius colombiensis, rhodnius pallescens and rhodnius prolixus in colombia, and from rhodnius pallescens in panama. strain characterisation involved a duplex pcr with s35/s36/kp1l primers. mini-exon gene analysis was also carried out using trint-1/trint-2 oligonucleotides. kdna and mini-exon amplification indicated dimorphism within both dna ...	2005	15639744
expression of fluorescent genes in trypanosoma cruzi and trypanosoma rangeli (kinetoplastida: trypanosomatidae): its application to parasite-vector biology.	two trypanosoma cruzi-derived cloning vectors, ptrex-n and pbs:calb1/cub01, were used to drive the expression of green fluorescent protein (gfp) and dsred in trypanosoma rangeli tejera, 1920, and trypanosoma cruzi chagas, 1909, isolates, respectively. regardless of the species, group, or strain, parasites harboring the transfected constructs as either episomes or stable chromosomal integrations showed high-level expression of fluorescent proteins. tagged flagellates of both species were used to ...	2005	15691008
[triatomines (reduviidae: triatominae) in a chagas disease focus in talaigua nuevo (bolívar, colombia)].	the epidemiological importance and ecological characteristics of triatomines were investigated in a chagas disease focus in talaigua nuevo, bolivar province.	2005	16433183
presence and activity of a dippu-dh31-like peptide in the blood-feeding bug, rhodnius prolixus.	the blood-feeding bug, rhodnius prolixus, ingests large blood meals, then undergoes a period of rapid diuresis which is under neurohormonal control. in both cockroach (diploptera punctata) and fruit fly (drosophila melanogaster) a calcitonin-like dh31 neuropeptide has been identified [coast gm, webster sg, schegg km, tobe ss, schooley da. the drosophila melanogaster homologue of an insect calcitonin-like diuretic peptide stimulates v-atpase activity in fruit fly malpighian tubules. j exp biol 20 ...	2005	15626502
tetraethylammonium and nicotine transport by the malpighian tubules of insects.	we examined transepithelial transport of the prototypical type i organic cation (oc) tetraethylammonium (tea) and the plant alkaloid nicotine by the isolated malpighian tubules (mts) of nine insect species from six orders. isolated tubules were exposed to radiolabelled forms of either tea or nicotine in the bathing (basal) fluid. luminal (apical) secreted fluid was collected and tea or nicotine concentration was determined. active net transport of nicotine from bath to lumen was observed by the ...	2006	16527303
trypanosoma cruzi: effects of infection on cathepsin d activity in the midgut of rhodnius prolixus.	cathepsin d activity was estimated in midgut homogenates from rhodnius prolixus, uninfected and experimentally infected with trypanosoma cruzi, at different times after blood ingestion. no enzyme activity was found in the anterior midgut and rectum. in the posterior midgut, enzyme activity was found both in lumen and wall. in starved uninfected insects, in lumen and wall, cathepsin d activity was high, decreasing to a constant rate at 1-15 days after feeding. in insects infected with t. cruzi ca ...	2006	16288741
trypanosoma rangeli: characterization of a mg-dependent ecto atp-diphosphohydrolase activity.	in this work we describe the ability of living trypanosoma rangeli to hydrolyze extracellular atp. in these intact parasites whose viability was assessed before and after the reactions by motility and by trypan blue dye exclusion, there was a low level of atp hydrolysis in the absence of any divalent metal (1.53+/-0.12 nmol p(i)/h x 10(7) cells). the atp hydrolysis was stimulated by mgcl(2) and the mg-dependent ecto-atpase activity was 5.24+/-0.64 nmol p(i)/h x 10(7) cells. the mg-dependent ecto ...	2006	16289087
trypanosoma rangeli: effects of physalin b on the immune reactions of the infected larvae of rhodnius prolixus.	physalins are seco-steroids obtained from plants of the family solanaceae. herein, we tested physalis angulata l purified physalin b as an immunomodulatory compound in 5th-instar larvae of rhodnius prolixus, which were systemically infected with the h14 trypanosoma rangeli strain protozoan. in uninfected insects, the effective concentration of physalin b, which inhibited 50% of the blood ingested (ed(50)) volume, was 15.2+/-1.6 microg/ml of the meal. ecdysis processes and mortality in uninfected ...	2006	16271717
analysis of antenal sensilla patterns of rhodnius prolixus from colombia and venezuela.	antennal sensilla patterns were used to analyze population variation of domestic rhodnius prolixus from six departments and states representing three biogeographical regions of colombia and venezuela. discriminant analysis of the patterns of mechanoreceptors and of three types of chemoreceptors on the pedicel and flagellar segments showed clear differentiation between r. prolixus populations east and west of the andean cordillera. the distribution of thick and thin-walled trichoids on the second ...	2006	16444424
take-off activity and orientation of triatomines (heteroptera: reduviidae) in relation to the presence of artificial lights.	we analysed the flying activity of triatoma infestans and rhodnius prolixus when confronted to artificial lights of different spectral quality. we found that the presence of light sources (white or ultraviolet) did not affect their spontaneous take-off rate. the comparison between species showed that r. prolixus was more prone to fly than t. infestans. females of t. infestans initiated flight more frequently than males of the same species. although the same tendency was observed in r. prolixus, ...	2006	16460653
parasitogenic alterations of vector behaviour.	in many parasite-vector systems, alterations of the behaviour of the blood-sucking arthropods result in an increase of the transmission rate, but the underlying mechanisms are elucidated in only some systems. the more sluggish movements of the trypanosoma rangeli-infected triatomine rhodnius prolixus might increase the rate of predation by insectivorous mammals but also the transmission rate between the triatomines via cannibalism. alterations of the feeding behaviour by which the number of atta ...	2006	16530007
salivation pattern of rhodnius prolixus (reduviidae; triatominae) in mouse skin.	the objective of this work was to study the pattern of salivation of triatomines during feeding in mouse skin. rhodnius prolixus was fed with a solution of the dye acridine orange or fluorescein. the saliva was efficiently labelled with acridine orange, probably due to the difference in ph between the salivary gland (6.0) and the hemolymph (6.5-7.0). this procedure was not effective at labelling the saliva of triatoma infestans, however, fluorescent labelling of r. prolixus saliva allowed us to ...	2006	16580013
trypanosoma cruzi: experimental parasitism of bone and cartilage.	trypanosoma cruzi causes chagas' disease, a systemic infection that affects cells of meso-, endo-, and ectodermic origin. however, as far as we know, the presence of t. cruzi stages in bone has not been reported previously, and it has scarcely been investigated in cartilage. we inoculated 7- and 20-day-old (8 and 15 g) nmri albino mice i.p. with metacyclic trypomastigotes from rhodnius prolixus used for xenodiagnosis of mice previously infected with mammalian, human, and triatomines isolates, ch ...	2006	16721600
control of chagas disease.	the southern cone initiative (iniciativa de salud del cono sur, incosur) to control domestic transmission of trypanosoma cruzi is a substantial achievement based on the enthusiasm of the scientific community, effective strategies, leadership, and cost-effectiveness. incosur triggered the launch of other regional initiatives in central america and in the andean and amazon regions, which have all made progress. the central american initiative targeted the elimination of an imported triatomine bug ...	2006	16735164
antiserum against perimicrovillar membranes and midgut tissue reduces the development of trypanosoma cruzi in the insect vector, rhodnius prolixus.	antiserum raised against rhodnius prolixus perimicrovillar membranes (pmm) and midgut tissue interfered with the midgut structural organization and reduced the development of trypanosoma cruzi in the r. prolixus insect vector. sds-page and western blot analyses confirmed the specific recognition of midgut proteins by the antibody. feeding, mortality, molt, and oviposition of the insects were unaffected by feeding with the antiserum. however, the eclosion of the eggs were reduced from r. prolixus ...	2006	16759654
cellular immune response in rhodnius prolixus: role of ecdysone in hemocyte phagocytosis.	in this paper we investigate in vivo and in vitro effects of orally administered azadirachtin and ecdysone on the phagocytic responses of rhodnius prolixus 5th-instar larval hemocytes to the yeast saccharomyces cerevisiae. groups of insects fed non-treated blood (control) and insects that received azadirachtin plus ecdysone in the blood meal were inoculated with yeast cells in the hemocele. the injected yeast cells disappeared rapidly from the hemolymph, being removed completely by 90min after i ...	2006	16759667
web 2086, a platelet-activating factor antagonist, inhibits prophenoloxidase-activating system and hemocyte microaggregation reactions induced by trypanosoma rangeli infection in rhodnius prolixus hemolymph.	the effects of the triazolodiazepine web 2086, a platelet-activating factor (paf) antagonist, on hemocyte microaggregation and prophenoloxidase (propo)-activating system in the hemolymph, hemocoelic infection and mortality in fifth-instar larvae of rhodnius prolixus inoculated with trypanosoma rangeli were investigated. hemocoelic injection of short t. rangeli epimastigotes (1x10(4) parasites/insect) in r. prolixus that were previously fed with blood containing 1mum of web 2086 resulted in (i) r ...	2006	16777137
taxonomic study of the phyllosoma complex and other triatomine (insecta: hemiptera: reduviidae) species of epidemiological importance in the transmission of chagas disease: using its-2 and mtcytb sequences.	the purpose of this work was to clarify the taxonomy and phylogenetic relationship of the phyllosoma complex and other important vectors in mexico. the internal transcribed spacer 2 (its-2) of rdna and the cytochrome b gene of mtdna (mtcytb) were analyzed for the following species of triatomine: triatoma bassolsae, t. longipennis, t. mazzottii, t. mexicana, t. pallidipennis, t. picturata, and t. phyllosoma belonging to the phyllosoma complex, as well as t. dimidiata, t. rubida, t. infestans, and ...	2006	16815044
a micro-spreading improvement for spermatogenic chromosomes from triatominae (hemiptera-reduviidae).	cytogenetics of triatomines have been a valuable biological tool for the study of evolution, taxonomy, and epidemiology of these vectors of trypanosoma cruzi. here we present a single microtube protocol that combines micro-centrifugation and micro-spreading, allowing high quality cytogenetic preparations from male gonadal material of rhodnius prolixus and triatoma lecticularia. the amount of cellular scattering can be modulated, which can be useful if small aggregates of synchronous cells are de ...	2006	16862334
rna interference of the salivary gland nitrophorin 2 in the triatomine bug rhodnius prolixus (hemiptera: reduviidae) by dsrna ingestion or injection.	mass sequencing of cdna libraries from salivary glands of triatomines has resulted in the identification of many novel genes of unknown function. the aim of the present work was to develop a functional rna interference (rnai) technique for rhodnius prolixus, which could be widely used for functional genomics studies in triatomine bugs. to this end, we investigated whether double-stranded rna (dsrna) can inhibit gene expression of r. prolixus salivary nitrophorin 2 (np2) and what impact this migh ...	2006	16935217
could the chagas disease elimination programme in venezuela be compromised by reinvasion of houses by sylvatic rhodnius prolixus bug populations?	the andean pact initiative (1997) committed andean countries to eliminate vectorial transmission of chagas disease by 2010 via widespread residual insecticide spraying. in venezuela, this aim could be compromised by reinvasion of houses by palm tree populations of the major vector rhodnius prolixus. to test this hypothesis, a multivariate logistic regression was undertaken of risk factors for triatomine infestation and colonization in 552 houses and 1068 peri-domestic outbuildings in barinas sta ...	2006	17002733
circadian orchestration of developmental hormones in the insect, rhodnius prolixus.	this review presents a new perspective on the circadian regulation and functions of insect developmental hormones. in rhodnius prolixus (hemiptera), the brain neuropeptide prothoracicotropic hormone (ptth) is released with a circadian rhythm that is controlled by paired photosensitive clocks in the brain. these clocks comprise the dorsal and lateral per/tim clock neurons known to regulate behavioral rhythms in drosophila. axons of ptth and clock cells make close contact. photosensitive per/tim c ...	2006	16702005
electrochemical gradients for na+, k+, cl- and h+ across the apical membrane in malpighian (renal) tubule cells of rhodnius prolixus.	measurements of intracellular and luminal ion activities as well as membrane potential were used to calculate electrochemical gradients for cl-, na+, k+ and h+ across the apical membrane during fluid secretion by malpighian tubules of rhodnius prolixus. the results show that the contribution of na+/h+ and/or k+/h+ exchangers to fluid secretion is feasible both in unstimulated and serotonin-stimulated tubules. similarly, the electrochemical potential for cl- is consistent with the passive movemen ...	2006	16651561
a secreted salivary inositol polyphosphate 5-phosphatase from a blood-feeding insect: allosteric activation by soluble phosphoinositides and phosphatidylserine.	type ii inositol polyphosphate 5-phosphatases (ipps) act on both soluble inositol phosphate and phosphoinositide substrates. in many cases, these enzymes occur as multidomain proteins in which the ipp domain is linked to lipid-binding or additional catalytic domains. rhodnius prolixus ipprp exists as an isolated ipp domain which is secreted into the saliva of this blood-feeding insect. it shows selectivity for soluble and lipid substrates having a 1,4,5-trisphosphate substitution pattern while o ...	2006	16634626
oligomerization of nitrophorins.	rhodnius prolixus is a blood-sucking insect that uses a mixture of nitrophorin (np) proteins to deliver nitric oxide (no) from the insect saliva to the hosts via a ferric heme coordinated to the protein, causing vasodilatation and anticoagulation to support their feeding. r. prolixus nps 1-4 are very similar proteins ( approximately 20 kda) with different no affinities for stepwise no release triggered by ph increase and histamine binding in hosts. ultra-high-resolution x-ray structures of nativ ...	2006	16574056
distribution, activity and evidence for the release of an anti-diuretic peptide in the kissing bug rhodnius prolixus.	in the haematophagous insect rhodnius prolixus, diuresis is accomplished through the combined actions of peptidergic diuretic hormones and 5-ht released from neurohaemal sites on the abdominal nerves. preliminary work on anti-diuresis in this blood-feeder, previously believed to occur through a decrease in the levels of the diuretic factors, indicates that an anti-diuretic hormone, with properties similar to cap2b (pelyafprvamide; recently renamed mas-capa-1), might also be present in r. prolixu ...	2006	16481579
ecto-nucleotidase activities in the fat body of rhodnius prolixus.	in this study, we describe the ability of intact fat body of an insect, rhodnius prolixus, to hydrolyze extracellular atp. in these fat bodies, the atp hydrolysis was low in the absence of any divalent metal, and was stimulated by mgcl(2). both activities (in the absence or presence of mgcl(2)) were linear with time for at least 30 min. in order to confirm the observed nucleotidase activities as ecto-nucleotidases, we used an impermeant inhibitor, dids (4, 4'-diisothiocyanostylbene 2'-2'-disulfo ...	2006	16380977
serotonin: a coordinator of feeding-related physiological events in the blood-gorging bug, rhodnius prolixus.	rhodnius prolixus is an obligatory blood-feeder that can ingest blood meals of up to 10 times its mass. rapid production of urine commences within 2-3 min of the start of feeding in order to eliminate the load of water and salts, and so there is an increase of malpighian tubule secretion greater than 1,000 fold in response to feeding. feeding and post-prandial diuresis in rhodnius are highly coordinated events, including for example, host recognition, probing, injection of saliva, cuticle plasti ...	2006	16377224
ecdysteroid hormone nuclear receptor (ecr) exhibits circadian cycling in certain tissues, but not others, during development in rhodnius prolixus (hemiptera).	the insect moulting hormones, viz. the ecdysteroids, regulate gene expression during development by binding to an intracellular protein, the ecdysteroid receptor (ecr). in the insect rhodnius prolixus, circulating levels of ecdysteroids exhibit a robust circadian rhythm. this paper demonstrates associated circadian rhythms in the abundance and distribution of ecr in several major target tissues of ecdysteroids, but not in others. quantitative analysis of immunofluorescence images obtained by con ...	2006	16323012
flight-oogenesis syndrome in a blood-sucking bug: biochemical aspects of lipid metabolism.	lipophorin (lp), either labeled in diacylglycerol moiety with [(3)h]-palmitic acid or in phospholipid moiety with (32)pi, was injected into rhodnius prolixus females. insects were induced to flight for different times. in just a few minutes of flight, the transfer of radioactivity to ovaries decreased, accompanied by its increase to flight muscles. after one hour of flight, lp density was higher (1.132 g/ml) than before flight (1.116 g/ml). lp purified from insects after flight was analyzed by g ...	2006	16933278
fifth instar experience reduces aversiveness of the plant extract ruda (ruta graveolens) in the adult triatomine rhodnius prolixus stal 1859.		2006	16859109
the haemoxisome: a haem-iron containing structure in the rhodnius prolixus midgut cells.	rhodnius prolixus midgut was analysed using transmission electron microscopy and electron spectroscopic imaging in order to localize the cellular structures involved in haem metabolism. in the posterior midgut, special cellular electron-dense structures were observed. these structures are here designated haemoxisomes. haemoxisomes are present in the epithelial cells at various time points after a blood meal. several days after the blood meal, some of them become less electron-dense. by electron ...	2006	16713601
a heme-degradation pathway in a blood-sucking insect.	hematophagous insects are vectors of diseases that affect hundreds of millions of people worldwide. a common physiological event in the life of these insects is the hydrolysis of host hemoglobin in the digestive tract, leading to a massive release of heme, a known prooxidant molecule. diverse organisms, from bacteria to plants, express the enzyme heme oxygenase, which catalyzes the oxidative degradation of heme to biliverdin (bv) ix, co, and iron. here, we show that the kissing bug rhodnius prol ...	2006	16698925
aspects of classification of hemiptera hemocytes from six triatomine species.	the objective of this work was to characterize, and compare different morphological types of hemocytes of rhodnius prolixus, rhodnius robustus, rhodnius neglectus, triatoma infestans, panstrongylus megistus, and dipetalogaster maximus. this information provides the basis for studying the cellular immune systems of these insects. seven morphological hemocyte types were identified by phase-contrast microscopy: prohemocytes, plasmatocytes, granular cells, cystocytes, oenocytoids, adipohemocytes and ...	2006	1842390
binding sites for igg-fc in hemocyte adherent cells of hematophagous bugs (rhodnius prolixus).		2006	2152199
short- and long-term effects of proallatotoxin (ethoxyprecocene ii) on rhodnius prolixus females.	oogenesis and oviposition can be inhibited in female of rhodnius prolixus by means of short-term experiment (first reproductive cycle) of a single dose of ethoxyprecocene ii given by ingestion. the inhibition is dose-dependent as measured by oocyte growth, egg maturation and egg deposition. in a long-term experiment (second and third reproductive cycles) egg production and oogenesis can be partially or totally re-established by subsequent blood meals without ethoxyprecocene ii. these findings su ...	2006	3333534
efficacy of ivermectin against the bloodsucking insect, rhodnius prolixus (hemiptera, triatominae).	ivermectin (0.2 mg/kg body weight) caused a high mortality in nymphs and adults of rhodnius prolixus following a single meal in mice sub-cutaneously injected with the drug. this effect was more evident in nymphs of 1st-and 2nd-instar than in older nymphs and adults. third-instar nymphs presented a high mortality when fed on mice treated with ivermectin 24 and 48 hours previously, while mortality was significantly reduced in nymphs fed on mice treated 72 hours before. surviving 3rd-instar nymphs ...	2006	3915765
[the teratogenic and toxic effect of unsaturated short-chain fatty acids in rhodnius prolixus].	the teratogenic role of two short-chain unsaturated fatty acids, octinoic acid and undecylenic acid on the hemimetabolic metamorphosis of the insect rhodnius prolixus (hemipter) is studied. the acids penetrate through the cuticle of the abdomen and tarsi, independently of the amount of distention. the effects are registered equally in satiated or hungry insects, in those treated topically or in those where the treatment was applied to the support paper. the acids apparently do not affect the for ...	2006	3915763
[on the mode of oviposition of triatoma megista and rhodnius prolixus].		2006	13943306
spectroscopic and functional characterization of nitrophorin 7 from the blood-feeding insect rhodnius prolixus reveals an important role of its isoform-specific n-terminus for proper protein function.	nitrophorins (nps) are a class of no-transporting and histamine-sequestering heme b proteins that occur in the saliva of the bloodsucking insect rhodnius prolixus. a detailed study of the newly described member, np7, is presented herein. no association constants for np7 [kiii(eq)(no)] reveal a drastic change when the ph is varied from 5.5 (reflecting the insect's saliva) to slightly above plasma ph (7.5) (>10(9) m-1 --> 4.0 x 10(6) m-1); thus, the protein promotes the storage of no in the insect ...	2007	17958381
effects of retinoids and juvenoids on moult and on phenoloxidase activity in the blood-sucking insect rhodnius prolixus.	retinoic acid and insect juvenile hormone (jh) are structurally related terpenoids which are widespread in nature and are involved in many biological events such as morphogenesis, embryogenesis and cellular differentiation. here, we investigated the effects of the retinoids 9-cis retinoic acid (9cisra), all trans retinol (atroh), all trans retinoic acid (atra) and the juvenoids methoprene (met) and jh injection on moult and on phenoloxidase activity in the blood-sucking insect rhodnius prolixus. ...	2007	17686447
neuroanatomical relations of prothoracicotropic hormone neurons with the circadian timekeeping system in the brain of larval and adult rhodnius prolixus (hemiptera).	this paper reports the localization in the rhodnius prolixus brain of neurons producing the key neuropeptide that regulates insect development, prothoracicotropic hormone (ptth) and describes intimate associations of the ptth neurons with the brain circadian timekeeping system. immunohistochemistry and confocal laser scanning microscopy revealed that the ptth-positive neurons in larvae are located in a single group in the lateral protocerebrum. their number increases from two in the last larval ...	2007	17534946
perimicrovillar membranes promote hemozoin formation into rhodnius prolixus midgut.	rhodnius prolixus is a hematophagous insect that ingests large quantities of blood in each blood-feeding session. this ingested blood provides important nutrients to sustain the insect's oogenesis and metabolic pathways. during the digestive process, however, huge amounts of heme are generated as a consequence of the hemoglobin breakdown. heme is an extremely dangerous molecule, since it can generate reactive oxygen species in the presence of oxygen that impair the normal metabolism of the insec ...	2007	17517329
rhodnius prolixus malpighian tubules and control of diuresis by neurohormones.	rhodnius prolixus malpighian tubules (mts) are a good model for fluid and ion secretion studies in view of the dramatic postprandial diuresis, which follows its massive blood meals. ingestion of a blood meal equals to 10-12 times their initial body mass, leads to rapid activation of high output by excretory system, which eliminates 40-50% of the fluid mass. secretion of ions and water is stimulated 1000-fold by serotonin and diuretic hormone. these hormones cooperate synergistically to activate ...	2007	17401478
allosteric regulation of 6-phosphofructo-1-kinase activity of fat body and flight muscle from the bloodsucking bug rhodnius prolixus.	6-phosphofructo-1-kinase (phosphofructokinase; pfk) activity from rhodnius prolixus, a haematophagous insect which is usually a poor flyer, was measured and compared in two metabolically active tissues - flight muscle and fat body. the activity of this important regulatory glycolytic enzyme was much more pronounced in muscle (15.1 +/- 1.4 u/mg) than in fat body extracts (3.6+/-0.4 u/mg), although the latter presented higher levels of enzyme per protein content, as measured by western-blotting. m ...	2007	17401475
calcium-regulated fusion of yolk granules is important for yolk degradation during early embryogenesis of rhodnius prolixus stahl.	this study examined the process of membrane fusion of yolk granules (ygs) during early embryogenesis of rhodnius prolixus. we show that eggs collected at days 0 and 3 after oviposition contain different populations of ygs, for example day-3 eggs are enriched in large ygs (lygs). day-3 eggs also contain the highest free [ca(2+)] during early embryogenesis of this insect. in vitro incubations of day-0 ygs with [ca(2+)] similar to those found in day-3 eggs resulted in the formation of lygs, as obse ...	2007	17170157
the interaction of feeding and mating in the hormonal control of egg production in rhodnius prolixus.	the evidence relating feeding and mating to hormonal control of egg production in rhodnius prolixus is reviewed from two perspectives. it identifies crucial areas in which information is lacking, and it attempts to relate the findings, most of which have been obtained on laboratory colonies isolated for many years, to the sylvan life of the insect as an opportunistic micropredator.	2007	17126364
exploring the role of insect host factors in the dynamics of trypanosoma cruzi-rhodnius prolixus interactions.	members of the subfamily triatominae, family reduviidae, comprise a large number of insect species of which some are vectors of trypanosoma cruzi, the causative agent of chagas' disease. this article outlines research on the process of transformation and the dynamics of developmental stages of trypanosoma cruzi in the triatomine insect hosts. special attention is given to the interactions of parasites with gut molecules, and the gut environment, and with host developmental physiology and intesti ...	2007	17141801
trypanosoma cruzi: attachment to perimicrovillar membrane glycoproteins of rhodnius prolixus.	studies were carried out to identify proteins involved in the interface of trypanosoma cruzi with the perimicrovillar membranes (pmm) of rhodnius prolixus. video microscopy experiments demonstrated high level of adhesion of t. cruzi dm 28c epimastigotes to the surface of posterior midgut cells of non-treated r. prolixus. the parasites however were unable to attach to gut cells obtained from decapitated or azadirachtin-treated insects. the influence of carbohydrates on the adhesion to insect midg ...	2007	17250827
replication of flock house virus in three genera of medically important insects.	flock house virus (family nodaviridae, genus alphanodavirus, fhv) was originally isolated from grass grubs costelytra zealandica (white) (coleoptera: scarabaeidae) in new zealand and belongs to a family of divided genome, plus-sense rna insect viruses. fhv replicates in insects, a nematode, plants, and yeast. we previously reported replication of fhv in four genera of mosquitoes and expression of green fluorescent protein in aedes aegypti (l.) produced by an fhv-based vector. we report here that ...	2007	17294927
morphometric evidence for a possible role of rhodnius prolixus from palm trees in house re-infestation in the state of barinas (venezuela).	the main vector of chagas disease in venezuela is rhodnius prolixus. specimens of rhodnius sp., identified elsewhere as r. prolixus by molecular tools, were collected in barinas state (venezuela) before insecticide application, and compared by morphometric techniques with post-spraying, re-infesting insects after control. geometric morphometry was applied, allowing separate analyses of shape and size. the idea of a single species sharing silvatic and domestic/peri-domestic ecotopes was supported ...	2007	17306204
trypanosoma cruzi: involvement of glycoinositolphospholipids in the attachment to the luminal midgut surface of rhodnius prolixus.	trypanosoma cruzi epimastigotes adhere in vivo to the luminal surface of their triatomid vector digestive tract by molecular mechanisms, as yet, unknown. here, we show that the administration of 0.5 microm epimastigote major surface glycoinositolphospholipids (gipls) to the infected bloodmeal inhibits up to 90% parasite infection in rhodnius prolixus. the parasite behavior was investigated in vitro using fragments of the insect midgut. the addition of gipls in concentration as low as 50-100 nm i ...	2007	17306256
rhodnius prolixus: identification of immune-related genes up-regulated in response to pathogens and parasites using suppressive subtractive hybridization.	we report the identification of immune-related molecules from the fat body, and intestine of rhodnius prolixus, an important vector of chagas disease. insects were challenged by introducing pathogens or trypanosoma cruzi, the parasite that causes chagas disease, into the hemocoel. rna from intestines, or fat body were isolated 24h after stimulation. we used suppressive subtractive hybridization to identify immune-related genes, generated three subtracted libraries, sequenced the clones and assem ...	2007	16824597
overexpression in escherichia coli and functional reconstitution of the liposome binding ferriheme protein nitrophorin 7 from the bloodsucking bug rhodnius prolixus.	a number of ferriheme proteins, termed nitrophorins (nps), occur in the saliva of the bloodsucking insect rhodnius prolixus ('kissing bug'), which is a vector for chagas' disease. nitrophorins bind the heme b cofactor in the beta-barrel of their lipocalin fold, which is further anchored through a proximal histidine-fe(iii) bond. the distal fe(iii) coordination site then binds nitric oxide (no) for delivery into a host's tissues during blood feeding, where, upon no release, the distal fe(iii) sit ...	2007	17428677
differential modulation of rhodnius prolixus nitric oxide activities following challenge with trypanosoma rangeli, t. cruzi and bacterial cell wall components.	nitric oxide (no) is a key immune effector and signaling molecule in many organisms. however, the contribution no makes towards insect immunity has received little attention, particularly in non-dipteran species. in this study, tissue- and time-specific alterations in no synthase (nos) gene expression and no production were documented in the hemipteran vector of chagas' disease, rhodnius prolixus, following in vivo immune challenge by trypanosoma cruzi, t. rangeli and crude bacterial lipopolysac ...	2007	17456439
acid phosphatase activity distribution in salivary glands of triatomines (heteroptera, reduviidae, triatominae).	acid phosphatase activity (gömori technique) in salivary gland cells was investigated in adult insects (males and females) of four species of triatomines: triatoma infestans, panstrongylus megistus, rhodnius neglectus, and rhodnius prolixus. binucleated cells with bulky and polyploidy nuclei were detected, with acid phosphatase activity in the heterochromatin and nucleolus, which showed the most intense response. thus, the activity of these phosphatases during rrna molecule transcription, possib ...	2007	17469069
[epidemiology of chagas disease in andrés eloy blanco, lara, venezuela: triatomine infestation and human seroprevalence].	a seroepidemiological survey and vector captures were performed in four rural communities in andrés eloy blanco, lara state, venezuela. systematic random sampling was based on family clusters, with samples drawn from 869 individuals to determine anti-trypanosoma cruzi and anti-leishmania sp. antibodies by indirect immunofluorescence. positive individuals were defined as > or = 1:32 for anti-t. cruzi antibody and non-reactive to leishmania sp. antigen, revealing an antibody frequency of 6.9% (n = ...	2007	17486235
risk factors for trypanosoma cruzi human infection in barinas state, venezuela.	this study attempted to quantify the transmission of trypanosoma cruzi in children less than 15 years of age in barinas state, venezuela and investigate risk factors for infection. among 3,296 children, 4 (0.12%) were seropositive. the mother of one child also was also seropositive, which suggested that congenital transmission is a possible risk factor for chagas disease in this area. seroprevalence among the dwellers of 10 localities was 3.3%. rhodnius prolixus was detected in 7 localities and ...	2007	17488916
lipid metabolism in rhodnius prolixus (hemiptera: reduviidae): role of a midgut triacylglycerol-lipase.	the utilization of dietary lipids was studied in adult females of rhodnius prolixus with the use of radiolabeled triacylglycerol (tag). it was shown that (3)h-triolein, when added to blood meal, was hydrolyzed to free fatty acids in the posterior midgut lumen. subsequently, free fatty acids were absorbed by posterior midgut epithelium and used in the synthesis of phospholipids, diacylglycerol (dag) and tag. phospholipids, dag and free fatty acids were then found in hemolymph, from where they wer ...	2007	17517335
effect of ectoparasitic pimeliaphilus plumifer mites (acari: pterygosomatidae) on meccus pallidipennis (hemiptera: reduviidae) and several other chagas' disease vectors under laboratory conditions.	several biological parameters were evaluated to determine the capacity of pimeliaphilus plumifer as biological control agent of triatominae bugs. when p. plumifer and bugs of a variety of triatomine species were forced together in cages in the laboratory, the incidence of mite infestation was the following: meccus pallidipennis > m. bassolsae > triatoma rubida > m. longipennis > m. picturatus, and practically no mites were found on t. infestans and rhodnius prolixus. adults and hexapod larvae of ...	2007	17549587
a multiplex pcr assay that separates rhodnius prolixus from members of the rhodnius robustus cryptic species complex (hemiptera: reduviidae).	rhodnius prolixus is one of the most important primary vectors of human chagas disease in latin america. its morphology is, however, identical to that of the members of the rhodnius robustus cryptic species complex, which includes secondary vectors. the correct identification of these taxa with differential vector competence is, therefore, of great epidemiological relevance. we used the alignment of 26 mitochondrial cytochrome b haplotypes (663 bp) to select for pcr-amplifiable species-specific ...	2007	17550472
trypanosoma cruzi: ultrastructural studies of adhesion, lysis and biofilm formation by serratia marcescens.	a few days after blood meal the number of bacteria in the anterior midgut (stomach) of rhodnius prolixus, a vector of trypanosoma cruzi, the causative agent of chagas' disease, increases dramatically. many of the bloodstream trypomastigotes of the pathogenic protozoan as well as ingested erythrocytes are lysed in the stomach. incubation of t. cruzi with serratia marcescens variant sm365, lead to parasite lysis. in the present study, this bacterium rapidly adhered to the protozoan surface through ...	2007	17570364
apo-nitrophorin 4 at atomic resolution.	the nitrophorins from rhodnius prolixus, the kissing bug, are heme-containing proteins used for the transport of nitric oxide to aide the insect in obtaining a blood meal. the rhodnius nitrophorins display an eight-stranded antiparallel beta-barrel motif, typical of lipocalins, with a histidine-linked heme in the open end of the barrel. heme is stabilized in the ferric state and highly distorted, displaying a ruffled conformation that may be of importance in the setting of the reduction potentia ...	2007	17660249
experimental transmission of the parasitic flagellates trypanosoma cruzi and trypanosoma rangeli between triatomine bugs or mice and captive neotropical bats.	trypanosoma cruzi and trypanosoma rangeli-like trypanosomes have been found in a variety of neotropical bat species. in this study, bats (artibeus lituratus, carollia perspicillata, desmodus rotundus, glossophaga soricina, molossus molossus, phyllostomus hastatus) were maintained under controlled conditions, and experiments were conducted to determine how they might become infected naturally with trypanosomes. all bats were first screened for existing infections by hemoculture and the examinatio ...	2007	17710299
current situation of chagas disease in central america.	chagas disease in central america is known since 1913 when the first human case was reported in el salvador. the other central american countries reported their first cases between 1933 and 1967. on october 1997 was launched the central american initiative for chagas disease control (ipca). the objectives of this sub-regional initiative are: (1) the elimination of rhodnius prolixus in central america; (2) the reduction of the domiciliary infestation of triatoma dimidiata; and (3) the elimination ...	2007	17713679
chagas disease in andean countries.	the andean countries' initiative (aci) for controlling chagas disease was officially created in 1997 within the framework of the hipolito unanue agreement (unanue) between the ministries of health of colombia, ecuador, peru, and venezuela. its objective was to interrupt transmission via vector and transfusion in the region, taking into account that there are 12.5 million people at risk in the four andean countries forming the initiative in the area and around 3 million people are infected by try ...	2007	17891273
do haematophagous bugs assess skin surface temperature to detect blood vessels?	it is known that some blood-sucking insects have the ability to reach vessels under the host skin with their mouthparts to feed blood from inside them. however, the process by which they locate these vessels remains largely unknown. less than 5% of the skin is occupied by blood vessels and thus, it is not likely that insects rely on a "random search strategy", since it would increase the probability of being killed by their hosts. indeed, heterogeneities along the skin surface might offer exploi ...	2007	17895973
biochemical properties of the major proteins from rhodnius prolixus eggshell.	two proteins from the eggshell of rhodnius prolixus were isolated, characterized and named rp30 and rp45 according to their molecular masses. purified proteins were used to obtain specific antiserum which was later used for immunolocalization. the antiserum against rp30 and rp45 detected their presence inside the follicle cells, their secretion and their association with oocyte microvilli. both proteins are expressed during the final stage of vitellogenesis, preserved during embryogenesis and di ...	2007	17916507
[population structure and genetic variability of rhodnius prolixus (hemiptera: reduviidae) from different geographic areas of colombia].	rhodnius prolixus is the most important vector of chagas disease in colombia. genetic characterization of this species is useful to understand its potential of dispersion. the distribution of the vector and the genetic population structure are important factors for the adequate implementation of control programs and epidemiological surveillance of chagas disease.	2007	18154243
[comparison of feeding and defecation patterns of rhodnius colombiensis and rhodnius prolixus(hempitera, reduviidae, triatominae) under laboratory conditions].	rhodnius colombiensis occasionally comes into human dwellings and consequently its role as an important potential vector in the transmission of american trypanosomiasis has been suggested.	2007	18154250
[updated geographical distribution and ecoepidemiology of the triatomine fauna (reduviidae: triatominae) in colombia].	information concerning triatomine records from provinces and municipalities was accumulated-including data indicating natural infections with trypanosomatides-that has been previously published or reported by colombian provincial health services and research institutes. altitude appeared to be the main factor responsible for the distribution of the insects. illustrations summarize the information provided by the above records. a triatomine fauna classification is presented that corresponds to th ...	2007	18154255
environmental determinants of the distribution of chagas disease vectors in south-eastern guatemala.	the associations between the presence of triatomines and environmental variables were studied using correlation analysis and logistic regression models for a sample of villages in the south-eastern provinces of guatemala. information on the presence of triatoma dimidiata, t. nitida and rhodnius prolixus came from entomological surveys carried out by the ministry of health of guatemala as part of its vector control programme. environmental information for each village was extracted from digital t ...	2007	18686245
[using elisa for identifying triatominae feeding behaviour in colombia].	standardising the elisa technique for identifying triatomine insects' feeding behaviour.	2007	18209827
distribution of fmrfamide-related peptides in the blood-feeding bug, rhodnius prolixus.	immunohistochemistry was used to study the distribution of fmrfamide-like material in the central and peripheral nervous systems and visceral tissues of 5th instar rhodnius prolixus. over 200 immunoreactive cell bodies and their processes as well as extensive neuropile regions were distributed throughout the nervous system. immunoreactive processes were seen over the cephalic aorta, corpus cardiacum/corpus allatum complex, and in neurohaemal sites on the abdominal nerves. in visceral tissues, im ...	2007	1939734
biglutaminyl-biliverdin ix alpha as a heme degradation product in the dengue fever insect-vector aedes aegypti.	hemoglobin digestion in the midgut of hematophagous animals results in the release of its prosthetic group, heme, which is a pro-oxidant molecule. heme enzymatic degradation is a protective mechanism that has been described in several organisms, including plants, bacteria, and mammals. this reaction is catalyzed by heme oxygenase and results in formation of carbon monoxide, ferrous ion, and biliverdin ixalpha. during digestion, a large amount of a green pigment is produced and secreted into the ...	2007	17508725
transepithelial transport of salicylate by the malpighian tubules of insects from different orders.	the organic anion salicylate is a plant secondary metabolite that protects plants against phytophagous insects. in this study, a combination of salicylate-selective microelectrodes and a radioisotope tracer technique was used to study the transepithelial transport of salicylate by the malpighian tubules of 10 species of insects from five orders. our results show that salicylate is transported into the lumen of the malpighian tubules in all the species evaluated, except rhodnius prolixus. the tra ...	2007	17640663
the biogeography and population genetics of neotropical vector species.	phylogenetic and population genetic data support the pliocene or pleistocene divergences of the co-distributed hematophagous insect vectors, the sand fly lutzomyia longipalpis s.l., the mosquitoes anopheles darlingi and a. albitarsis s.l., and the triatomines rhodnius prolixus and r. robustus. we examined patterns of divergence and distribution in relation to three hypotheses of neotropical diversification: miocene/pliocene marine incursion, pliocene/pleistocene riverine barriers and pleistocene ...	2007	17534382
effect of the n-terminus on heme cavity structure, ligand equilibrium, rate constants, and reduction potentials of nitrophorin 2 from rhodnius prolixus.	the d1a mutant of recombinant np2 has been prepared and shown to have the expression-initiation methionine-0 cleaved during expression in e. coli, as is the case for recombinant np4, where ala is the first amino acid for the recombinant protein as well as for the mature native protein. the heme substituent 1h nmr chemical shifts of np2-d1a and those of its imidazole, n-methylimidazole, and cyanide complexes are rather different from those of np2-m0d1. this difference is likely due to the much sm ...	2007	17506528
recent advances in understanding the mechanism of hemozoin (malaria pigment) formation.	the recent literature on hemozoin/beta-hematin formation is reviewed, with an emphasis on the mechanism of its formation. recent findings from unrelated organisms that produce hemozoin, namely the malaria parasite plasmodium falciparum, the worm schistosoma mansoni and the kissing bug rhodnius prolixus all of which consume human hemoglobin show that the formation of this crystalline substance occurs within or at the surface of lipids. biomimetic experimental models of the lipid-water interface a ...	2008	18226838
immune depression in rhodnius prolixus by seco-steroids, physalins.	a comparative study of the effects of physalins, seco-steroidal substances of physalis angulata (solanaceae), on the immune reactions of r. prolixus was carried out. ecdysis and mortality were not affected by treatment with physalins b, d, f or g (1-10 microg/ml of blood meal). r. prolixus larvae fed with blood containing physalins and inoculated with 1 microl of enterobacter cloacae beta12 (5 x 10(3)/insect) exhibited mortality rates three times higher than controls. the insects treated with ph ...	2008	18234209
identification and characterization of two novel lysozymes from rhodnius prolixus, a vector of chagas disease.	lysozymes have been described in invertebrates as digestive or immune molecules. we report here the characterization of two novel c-type lysozymes, rplys-a (eu250274) and rplys-b (eu250275), isolated from the fat body and digestive tract of immune stimulated rhodnius prolixus, a major vector of chagas disease. transcriptional profiles indicate that the temporal and spatial expression patterns of these two peptides are very different. rplys-a is expressed predominantly in the midgut after ingesti ...	2008	18258253
trypanosoma cruzi infection is enhanced by vector saliva through immunosuppressant mechanisms mediated by lysophosphatidylcholine.	trypanosoma cruzi, the etiological agent of chagas disease, is transmitted by bug feces deposited on human skin during a blood meal. however, parasite infection occurs through the wound produced by insect mouthparts. saliva of the triatominae bug rhodnius prolixus is a source of lysophosphatidylcholine (lpc). here, we tested the role of both triatomine saliva and lpc on parasite transmission. we show that vector saliva is a powerful inducer of cell chemotaxis. a massive number of inflammatory ce ...	2008	18794282
biological characterization of trypanosoma cruzi stocks from domestic and sylvatic vectors in sierra nevada of santa marta, colombia.	sierra nevada of santa marta is one of the most endemic regions of chagas disease in colombia. in this study, we compared the biological behavior and genetic features of trypanosoma cruzi stocks that were isolated from domestic and sylvatic insects in this area. rhodnius prolixus (from domestic environments) and triatoma dimidiata (from sylvatic, peridomestic and domestic environments) are the most important vectors in this region. genetic characterization showed that all stocks corresponded to ...	2008	18804443
hyaluronidase of bloodsucking insects and its enhancing effect on leishmania infection in mice.	salivary hyaluronidases have been described in a few bloodsucking arthropods. however, very little is known about the presence of this enzyme in various bloodsucking insects and no data are available on its effect on transmitted microorganisms. here, we studied hyaluronidase activity in thirteen bloodsucking insects belonging to four different orders. in addition, we assessed the effect of hyaluronidase coinoculation on the outcome of leishmania major infection in balb/c mice.	2008	18820742
lipid mediators and vector infection: trypanosoma rangeli inhibits rhodnius prolixus hemocyte phagocytosis by modulation of phospholipase a2 and paf-acetylhydrolase activities.	in this work we investigated the effects of trypanosoma rangeli infection through a blood meal on the hemocyte phagocytosis in experiments using the 5th instar larvae of rhodnius prolixus. hemocyte phagocytic activity was strongly blocked by oral infection with the parasites. in contrast, hemocyte phagocytosis inhibition caused by t. rangeli infection was rescued by exogenous arachidonic acid (20 microg/insect) or platelet activating factor (paf; 1 microg/insect) applied by hemocelic injection. ...	2008	18835273
comparative peptidomics of four related hemipteran species: pyrokinins, myosuppressin, corazonin, adipokinetic hormone, snpf, and periviscerokinins.	we performed the first comprehensive peptidomic analysis of neurohormones from hemipteran insects by analyzing the neuropeptides of two major neurohemal organs, namely the corpora cardiaca and abdominal perisympathetic organs. for the experiments we selected four related species of polyphagous stinkbugs (pentatomidae), three of which are known to attack several important food crops. peptide sequences were identified by maldi-tof mass spectrometry; tandem fragmentation of myosuppressin, snpf, cap ...	2008	18201800
blockades of phospholipase a(2) and platelet-activating factor receptors reduce the hemocyte phagocytosis in rhodnius prolixus: in vitro experiments.	the hemocytes phagocytosis in response to microorganisms may play an important role in the cellular immune responses of insects. here, we have evaluated the effects of the platelet-activating factor (paf) and eicosanoids in the phagocytosis of hemocyte monolayers of rhodnius prolixus to the yeast saccharomyces cerevisiae. experiments showed that the phagocytosis of yeast cells by rhodnius hemocytes is very efficient in both controls and cells treated with paf and arachidonic acid. phagocytosis o ...	2008	18036540
haemozoin formation.	formation of malaria pigment or haemozoin is the major route of haem detoxification in the malaria parasite plasmodium falciparum as well as several other species of haematophagous organisms, including other plasmodium species, helminth worms such as schistosoma mansoni and blood-sucking insects such as rhodnius prolixus. recent advances in our understanding of the formation of haemozoin, both from new observations that it is formed within lipid bodies in p. falciparum and s. mansoni and biomime ...	2008	18083247
differential actions of diuretic factors on the malpighian tubules of rhodnius prolixus.	the effects of corticotropin-releasing factor (crf)-related (zoonedh), calcitonin (ct)-related (rhoprdh(31)) and kinin-related (leucokinin i) peptides on the ion composition of fluid secreted by upper rhodnius prolixus malpighian tubules and on kcl reabsorption by the lower tubules were assessed. zoonedh stimulated fluid secretion while increasing the [na(+)] of secreted fluid at the expense of [k(+)]. upper tubules responded to zoonedh with a characteristic triphasic change in the transepitheli ...	2008	18083731
microsatellite markers from the chagas disease vector, rhodnius prolixus (hemiptera, reduviidae), and their applicability to rhodnius species.	ten microsatellites were isolated and characterized from a partial genomic library of rhodnius prolixus, the principal chagas disease vector in venezuela, colombia and central america. these polymorphic molecular markers could be particularly useful in chagas disease control initiatives. a wider applicability of the primer-pairs isolated was shown, from 6 to 10 loci being amplifiable in five out of the ten rhodnius species tested, namely r. domesticus, r. nasutus, r. neglectus, r. neivai and r. ...	2008	18304894
genetic transformation of a corynebacterial symbiont from the chagas disease vector triatoma infestans.	insect-borne diseases have experienced a troubling resurgence in recent years. emergence of resistance to pesticides greatly hampers control efforts. paratransgenesis, or the genetic transformation of bacterial symbionts of disease vectors, is an alternative to traditional approaches. previously, we developed paratransgenic lines of rhodnius prolixus, a vector of chagas disease in central america. here, we report identification of a corynebacterial species as a symbiont of triatoma infestans, a ...	2008	18331732
molecular genetics reveal that silvatic rhodnius prolixus do colonise rural houses.	rhodnius prolixus is the main vector of chagas disease in venezuela. here, domestic infestations of poor quality rural housing have persisted despite four decades of vector control. this is in contrast to the southern cone region of south america, where the main vector, triatoma infestans, has been eliminated over large areas. the repeated colonisation of houses by silvatic populations of r. prolixus potentially explains the control difficulties. however, controversy surrounds the existence of s ...	2008	18382605
ecto-phosphatase activity on the external surface of rhodnius prolixus salivary glands: modulation by carbohydrates and trypanosoma rangeli.	the salivary glands of insect's vectors are target organs to study the vectors-pathogens interactions. rhodnius prolixus an important vector of trypanosoma cruzi can also transmit trypanosoma rangeli by bite. in the present study we have investigated ecto-phosphatase activity on the surface of r. prolixus salivary glands. ecto-phosphatases are able to hydrolyze phosphorylated substrates in the extracellular medium. we characterized these ecto-enzyme activities on the salivary glands external sur ...	2008	18407240
preliminary characterization of a rhodnius prolixus hemolymph trypanolytic protein, this being a determinant of trypanosoma rangeli kp1(+) and kp1(-) subpopulations' vectorial ability.	rhodnius prolixus is the main trypanosoma rangeli vector in several latin-american countries and is susceptible to infection with kp1(+) strains; however, it presents an invasion-resistant response to kp1(-) strains. the present work has identified a trypanolytic protein against t. rangeli kp1(-) in the r. prolixus hemolymph which was fractioned with ammonium sulfate (following dialysis). the results revealed a protein component which did not depend on divalent cations for its biological functio ...	2008	18425269
characteristics of plasminogen binding to trypanosoma cruzi epimastigotes.	the binding constants of the interaction between plasminogen and trypanosoma cruzi epimastigotes were determined. an indirect method in which the bound plasminogen is detached from the cell by epsilon-aminocaproic acid and a direct method through biotinylated plasminogen were used. the analyses revealed a dissociation constant (kd) from 0.4 to 1.2microm, these values being compatible with recognition in vivo. moreover, epimastigotes from the gut of rhodnius prolixus were able to bind plasminogen ...	2008	18501871
learning and orientation to odor in the bug rhodnius prolixus stal 1859 under laboratory conditions.	two experiments are described investigating learning and orientation in the triatomine rhodnius prolixus. in experiment 1, pavlovian conditioning was investigated. the experiment differed from our previous work in that the intensity of the conditioned and unconditioned stimuli were reduced and the number of training trials increased. once again, no evidence for pavlovian conditioning was found. in experiment 2, an "orientation arena" was developed in which the orientation of r. prolixus to a hum ...	2008	18509679