Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| 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 |
| phagocytosis of latex beads and bacteria by hemocytes of the triatomine bug rhodnius prolixus (hemiptera: reduvidae). | insect circulating hemocytes are primarily responsible for the immune defense against parasites and pathogens. here, we have analyzed phagocytosis of both biotic (bacteria) and abiotic (latex) particles by circulating hemocytes of 5th-instar nymphs of the triatomine bug rhodnius prolixus. the following hemocyte types were identified: prohemocytes, plasmatocytes, granulocytes, oenocytoids and adipohemocytes. there was a considerable change in the relative percentage of plasmatocytes and prohemocy ... | 2008 | 17368036 |
| 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 |
| distribution and activity of a dippu dh31-like peptide in the large milkweed bug oncopeltus fasciatus. | the milkweed bug, oncopeltus fasciatus, is a plant feeding hemipteran. while there has been much research done on the neurohormonal control of the post-feeding diuresis in the blood-feeding hemipteran, rhodnius prolixus, little is known about the control of the post-feeding diuresis in o. fasciatus. one of the neurohormones that may play a role in this rapid diuresis belongs to the calcitonin-like diuretic hormone (dh31) family of insect peptides. in this study we demonstrate the presence of dh3 ... | 2008 | 18206263 |
| degradation of the neolignan, burchellin in the hemolymph of the bloodsucking insect rhodnius prolixus. | the neolignan, burchellin, a natural compound that reduces urine excretion in larvae of the bloodsucking bug, rhodnius prolixus, a vector of chagas' disease, is rapidly degraded in the hemolymph of the insect. the main product that accumulates in this tissue has been shown to be piperonyl alcohol. other catabolites have been identified by gc-ms analysis. | 2008 | 17904765 |
| assignment of ferriheme resonances for high- and low-spin forms of nitrophorin 3 by h and c nmr spectroscopy and comparison to nitrophorin 2: heme pocket structural similarities and differences. | nitrophorin 3 (np3) is the only one of the four major no-binding heme proteins found in the saliva of the blood-sucking insect rhodnius prolixus (also called the kissing bug) for which it has not been possible to obtain crystals of diffraction quality for structure determination by x-ray crystallography. thus we have used nmr spectroscopy, mainly of the hyperfine-shifted ferriheme substituent resonances, to learn about the similarities and differences in the heme pocket and the iron active site ... | 2008 | 19262680 |
| laboratory evaluation of the effects of triflumuron on the development of rhodnius prolixus nymph. | studies were carried out to evaluate the efficacy of the growth regulator, triflumuron (tfm) (starycide sc 480 bayer), for disrupting the development of rhodnius prolixus fifth-instar nymph by oral, topical or continuous treatment. all treatments were able to induce high levels of mortality, delay development and molt inhibition. oral treatment induced molt inhibition in all insects that survived at doses of 0.25, 0.50 and 5.0 mg/ml of a blood meal. the highest levels of both mortality in 24 h a ... | 2008 | 19148427 |
| assignment of the ferriheme resonances of high- and low-spin forms of the symmetrical hemin-reconstituted nitrophorins 1-4 by 1h and 13c nmr spectroscopy: the dynamics of heme ruffling deformations. | the four major nitrophorins (nps) of the adult blood-sucking insect rhodnius prolixus have been reconstituted with the "symmetrical hemin" 2,4-dimethyldeuterohemin, and their nmr spectra have been investigated as the high-spin (s=5/2) aqua and low-spin (s=1/2) n-methylimidazole (nmeim) and cyanide complexes. the nmeim complexes allow assignment of the high-spin hemin resonances by saturation transfer difference spectroscopy. the cyanide complexes were investigated as paramagnetic analogues of th ... | 2008 | 18458965 |
| dynamics of lipid accumulation by the fat body of rhodnius prolixus: the involvement of lipophorin binding sites. | in insects, lipids are stored in the fat body, mainly as triacylglycerol (tag). in rhodnius prolixus, a hematophagous hemipteran, lipids are accumulated after blood meal to be used later on. in adult females, at the second day after feeding, the amount of tag was 57+/-17 microg/fat body, it increased almost five times and at fourth day it was 244+/-35 microg/fat body. tag content remained constant until day 13, but it then decreased and, at day 20th it was very low (31+/-4.9 microg/fat body). ra ... | 2008 | 18395740 |
| metasternal gland volatiles and sexual communication in the triatomine bug, rhodnius prolixus. | twelve compounds produced by the metasternal glands (mgs) of the triatomine bug rhodnius prolixus were identified by solid phase microextraction (spme) combined with coupled gas chromatography-mass spectrometry (gc-ms) using achiral and chiral columns. all substances were ketones or alcohols, and the same compound profile was found in the secretions produced by either sex. the most abundant compounds were 2-methyl-3-buten-2-ol, (2s)-pentanol, (3e)-2-methyl-3-penten-2-ol, and (2r/2s)-4-methyl-3-p ... | 2008 | 18317844 |
| amino acid sequence and biological activity of a calcitonin-like diuretic hormone (dh31) from rhodnius prolixus. | diuresis in the blood-gorging hemipteran rhodnius prolixus is under neurohormonal control and involves a variety of processes and tissues. these include ion and water movement across the epithelium of the crop and the malpighian tubules, and muscle contractions of the crop, hindgut and dorsal vessel, which facilitate mixing of the blood-meal, mixing of the haemolymph, as well as the expulsion of waste. one of the neurohormones that might play a role in this rapid diuresis belongs to the calciton ... | 2008 | 18203994 |
| characterization of neuropeptide f-like immunoreactivity in the blood-feeding hemipteran, rhodnius prolixus. | the invertebrate neuropeptide y (npy) homolog, neuropeptide f (npf), has been characterized for a wide range of invertebrate phyla, including platyhelminthes, molluscs, and arthropods. current hypotheses suggest that npf may be capable of regulating responses to diverse external cues related to nutritional status and feeding. the qualitative and quantitative distribution of an npf-like peptide in fifth instar rhodnius prolixus was undertaken using an antiserum raised against drosophila npf. immu ... | 2008 | 18201798 |
| decrease in deet repellency caused by nitric oxide in rhodnius prolixus. | n,n-diethyl-3-methylbenzamide (deet) is widely used as an insect repellent; however, little is known about its mode of action. on the other hand, nitric oxide (no) participates in the olfaction transduction pathway of insects. in this work, nitroso-acetyl-cysteine (snac), a nitric oxide donor, or dibutyril-cyclic-gmp (db-cgmp), the cyclic nucleotide analog, were applied on fifth instar nymphs of rhodnius prolixus before exposing them to deet, to obtain information about the possible role of no/c ... | 2008 | 18088059 |
| carbohydrate accumulation and utilization by oocytes of rhodnius prolixus. | the processes of accumulation and mobilization of carbohydrate stores in eggs of rhodnius prolixus were analyzed. during oogenesis, the total amounts of glycogen, glucose, and trehalose increased with an accumulation of proteins, especially when oocytes grew from 1.0 to 1.5 mm in length. at 2.0 mm length, when oocytes were ready for oviposition, nutrient reserves did not increase appreciably and trehalose content decreased. mating did not affect the final content of carbohydrates or proteins in ... | 2008 | 18064701 |
| temporal modulation and adaptive control of the behavioural response to odours in rhodnius prolixus. | it has been demonstrated in several insect species that a circadian clock makes the whole of antennal chemoreceptors more sensitive during a particular temporal window every day. this assessment raises the question about how insects exhibiting bimodal activity handle their sensitivity to odours which are relevant at different moments of the day. to shed some light on this problem, we studied in rhodnius prolixus the daily dynamics of their responsiveness to co(2) (host-associated cue) and aggreg ... | 2008 | 18692504 |
| cytochemical characterization of microvillar and perimicrovillar membranes in the posterior midgut epithelium of rhodnius prolixus. | perimicrovillar membranes (pmm) are structures present on the surface of midgut epithelial cells of the hematophagous insect, rhodnius prolixus. they cover the microvilli and are especially evident 10 days after blood meal, providing the compartmentalization of the enzymatic processes in the intestinal microenvironment. using an enzyme cytochemical approach, mg2+-atpase and ouabain-sensitive na+k+-atpase activities were observed in the plasma (or microvillar) membrane (mm) of midgut cells and in ... | 2009 | 18602023 |
| a one-residue switch reverses the orientation of a heme b cofactor. investigations of the ferriheme no transporters nitrophorin 2 and 7 from the blood-feeding insect rhodnius prolixus. | this study represents the identification of a single amino acid residue that has the major responsibility for the isomeric orientation of a heme b cofactor in a ferriheme protein. the insertion of hemin b into the asymmetric environment of a protein pocket facilitates two cofactor orientations, a and b, which is often called "heme rotational disorder". the proteins studied herein are nitrophorins, a class of ferriheme proteins found in the saliva of the blood-sucking insect rhodnius prolixus, in ... | 2009 | 19140692 |
| ecology of north american triatominae. | in all, 40 native triatomine species and subspecies occur in na, belonging to six genera from the triatomini (triatoma, paratriatoma, panstrongylus, dipetalogaster, belminus, eratyrus), and one genus from the rhodniini (represented by one non-native species rhodnius prolixus, formerly occurring exclusively in domestic habitats); 28 species are found exclusively in mexico (and/or central america), eight are shared between the united states (us) and mexico, and four occur exclusively in the us. th ... | 2009 | 19084490 |
| antennal pathways in the central nervous system of a blood-sucking bug, rhodnius prolixus. | the haematophagous bug rhodnius prolixus has been a model system in insect physiology for a long time. recently, several studies have been devoted to its sensory systems, including olfaction. however, few data are available on the basic organisation of the nervous system in this species. by means of neuronal backfills, histology, confocal microscopy and three-dimensional reconstruction methods, we have characterized the projection patterns of antennal sensory neurons within the central nervous s ... | 2009 | 18809510 |
| effect of mutation of carboxyl side-chain amino acids near the heme on the midpoint potentials and ligand binding constants of nitrophorin 2 and its no, histamine, and imidazole complexes. | nitrophorins (nps) are a group of no-carrying heme proteins found in the saliva of a blood-sucking insect from tropical central and south america, rhodnius prolixus, the "kissing bug". no is kept stable for long periods of time by binding it as an axial ligand to a ferriheme center. the fact that the nitrophorins are stabilized as fe(iii)-no proteins is a unique property because most heme proteins are readily autoreduced by excess no and bind no to the fe(ii) heme irreversibly (k(d)s in the pico ... | 2009 | 19175316 |
| metabolic rate controls respiratory pattern in insects. | the majority of scientific papers on the subject of respiratory patterns in insects have dealt with the discontinuous gas-exchange cycle (dgc). the dgc is characterized by the release of bursts of co(2) from the insect, followed by extended periods of spiracular closure. several hypotheses have been put forward to explain the evolutionary origin and physiological function of this unusual respiratory pattern. we expand upon one of these (the oxidative damage hypothesis) to explain not only the oc ... | 2009 | 19151217 |
| neuroendocrine control of ionic homeostasis in blood-sucking insects. | the pioneering work of simon maddrell established that the rapid postprandial diuresis of the haematophagous insect rhodnius prolixus is controlled by a diuretic hormone and demonstrated the role of the malpighian tubules in meeting the volumic, osmotic and ionic challenges posed by an enormous blood meal. a number of diuretic and antidiuretic hormones that control secretion of primary urine by malpighian tubules have now been identified, but little is known of the interplay between these hormon ... | 2009 | 19151213 |
| too much of a good thing: how insects cope with excess ions or toxins in the diet. | much of our understanding of the ionoregulatory and excretory physiology of blood-feeding insects can be traced to a series of papers by simon maddrell and colleagues in the 1970s and 1980s. these studies of the malpighian (renal) tubules of rhodnius prolixus revealed a number of physiological adaptations to the short-term and long-term stresses associated with blood feeding. more recent electrophysiological studies using voltage- and ion-selective microelectrodes have extended our understanding ... | 2009 | 19151211 |
| behavioural and physiological state dependency of host seeking in the blood-sucking insect rhodnius prolixus. | vertebrate blood is essential for the growth and the reproduction of haematophagous insects. provided that hosts play the double role of food sources and predators, feeding on their blood exposes these insects to a high predation risk. therefore, it is expected that host seeking occurs only when insects need to feed. in the present study, we analyse how the feeding status affects the response to host-associated cues in the blood-sucking insect rhodnius prolixus. we show that the responsiveness t ... | 2009 | 19617431 |
| functional anatomy of vagina muscles in the blood-feeding insect, rhodnius prolixus. | the physiology of the muscles associated with the vagina in the blood-feeding insect, rhodnius prolixus stal, was investigated with the use of methylene blue staining to visualize the anatomy, and a micro force transducer to record spontaneous and neurally-evoked contractions. the vagina is associated with a dorsal muscle and a set of paired lateral muscles. the dorsal muscle extends from the base of the common oviduct to apodemes located laterally on sternite viii, the first genital segment. th ... | 2009 | 19573623 |
| peptides and serotonin control feeding-related events in rhodnius prolixus. | rhodnius prolixus periodically gorges on a blood meal that could compromise salt and water balance. this, however, is prevented by rapid production of urine within minutes of feeding. the malpighian tubules increase their rate of secretion 1,000 fold leading to the production of a hypo-osmotic urine that is high in nacl content. feeding and post-prandial diuresis in r. prolixus are tightly coordinated events, involving a variety of neurons within the central nervous system. the present review co ... | 2009 | 19482642 |
| biological activity of diuretic factors on the anterior midgut of the blood-feeding bug, rhodnius prolixus. | probing of a host and ingestion of a blood-meal in a fifth instar rhodnius prolixus results in a cascade of tightly integrated events, including salivary gland secretion, plasticization of the abdominal cuticle, increased ion and water movement across the anterior midgut (crop) and malpighian tubules (which rapidly produce urine) and the regular expulsion of urine from the hindgut. in this study we have focussed on the role of the anterior midgut during the rapid postprandial diuresis. the huge ... | 2009 | 19408362 |
| protein dynamics of a beta-sheet protein. | rhodnius prolixus nitrophorin 4 (abbreviated np4) is an almost pure beta-sheet heme protein. its dynamics is investigated by x-ray structure determination at eight different temperatures from 122 to 304 k and by means of mössbauer spectroscopy. a comparison of this beta-sheet protein with the pure alpha-helical protein myoglobin (abbreviated mbmet) is performed. the mean square displacement derived from the mössbauer spectra increases linearly with temperature below a characteristic temperature ... | 2009 | 19271215 |
| ecdysteroid receptor (ecr) is associated with microtubules and with mitochondria in the cytoplasm of prothoracic gland cells of rhodnius prolixus (hemiptera). | we have shown previously that ecr in larval rhodnius is present in the cytoplasm of various cell types and undergoes daily cycling in abundance in the cytoplasm (vafopoulou and steel, 2006. cell tissue res 323:443-455). it is unknown which organelles are associated with ecr. here, we report that cytoplasmic ecr in prothoracic gland cells is associated with both microtubules and mitochondria, and discuss the implications for both nuclear and non-genomic actions of ecr. ecr was localized immunohis ... | 2009 | 19847923 |
| cloning and characterization of dorsal homologues in the hemipteran rhodnius prolixus. | rhodnius prolixus is an ancient haematophagous hemipteran insect capable of mounting a powerful immune response. this response is transcriptionally regulated in part by transcription factors of the rel/nuclear factor kappa b (rel/nf-kappab) family. we have cloned and characterized three members of this transcription factor family in this insect. dorsal 1a is primarily expressed in early developmental stages. in contrast, dorsal 1b and 1c, both differentially spliced products of dorsal 1a, are ex ... | 2009 | 19754745 |
| synthesis and mobilization of glycogen and trehalose in adult male rhodnius prolixus. | the vector of chagas' disease, rhodnius prolixus, feeds exclusively on blood. the blood meals are slowly digested, and these insects wait some weeks before the next meal. during the life of an insect, energy-requiring processes such as moulting, adult gonadal and reproductive growth, vitellogenesis, muscular activity, and fasting, lead to increased metabolism. carbohydrates are a major source of energy and their mobilization is important. we determined the amounts of glycogen, trehalose, and glu ... | 2009 | 19514081 |
| fumigant insecticidal activity and repellent effect of five essential oils and seven monoterpenes on first-instar nymphs of rhodnius prolixus. | the aim of this study was to evaluate the fumigant and repellent activity of five essential oils (from eucalyptus, geranium, lavender, mint, and orange oil) and seven monoterpenes (eucalyptol, geraniol, limonene, linalool, menthone, linalyl acetate, and menthyl acetate) on first-instar nymphs of the bloodsucking bug rhodnius prolixus stahl (vector of chagas disease in several latin american countries). fumigant activity was evaluated by exposing the nymphs to the vapors emitted by 100 microl of ... | 2009 | 19496421 |
| the neuropeptidome of rhodnius prolixus brain. | we show a sensitive and straightforward off-line nano-lc-maldi-ms/ms workflow that allowed the first comprehensive neuropeptidomic analysis of an insect disease vector. this approach was applied to identify neuropeptides in the brain of rhodnius prolixus, a vector of chagas disease. this work will contribute to the annotation of genes in the ongoing r. prolixus genome sequence project. peptides were identified by de novo sequencing and comparisons to known neuropeptides from different organisms ... | 2009 | 19137558 |
| [effect of the desiccant dry-die-67 on rhodnius prolixus stal. bugs]. | 2009 | 6341798 | |
| [toxicity of the preparation drayon for the bug rhodnius prolixus stal (order hemiptera, family triatomidae)]. | 2009 | 803609 | |
| trypanosoma cruzi: biological characterization of lineages i and ii supports the predominance of lineage i in colombia. | the causes of the particular distribution of both trypanosoma cruzi lineages throughout the american continent remain unknown. in colombia, t. cruzi i is the predominant group in both domestic and sylvatic cycles. here, we present the biological characterization of t. cruzi parasites belonging to both t. cruzi i and t. cruzi iib groups. our results show the inability of the t. cruzi iib clones to infect mammalian cells, produce trypomastigotes and replicate in rhodnius prolixus, the main vector ... | 2009 | 18950627 |
| the role of salivary nitrophorins in the ingestion of blood by the triatomine bug rhodnius prolixus (reduviidae: triatominae). | to assist haematophagy, rhodnius prolixus produces several bioactive molecules in its saliva which it injects into the host skin. the most abundant of these molecules are the nitrophorins (nps). in this work, we reduced the expression of np1-4 in the saliva of r. prolixus by rnai and evaluated the subsequent feeding performance of the bugs using the cibarial pump electromyogram either on the dorsal skin or on the tail vein of the mice. nps salivary mrna was reduced by >99% in comparison to contr ... | 2009 | 18992340 |
| arrest of oogenesis in the bug rhodnius prolixus challenged with the fungus aspergillus niger is mediated by immune response-derived pge2. | in this work we characterized the immune response of the insect rhodnius prolixus to a direct injection into the hemocoel of the non-entomopathogenic fungus aspergillus niger, and evaluated its consequences on host oogenesis. these animals were able to respond by mounting effective cellular and humoral responses to this fungus; these responses were shown, however, to have reproductive fitness costs, as the number of eggs laid per female was significantly reduced. the disturbance of egg formation ... | 2009 | 19059412 |
| a panel of ten microsatellite loci for the chagas disease vector rhodnius prolixus (hemiptera: reduviidae). | rhodnius prolixus is the main vector of chagas disease in venezuela, where it is found colonising rural housing consisting of unplastered adobe walls with palm and/or metal roofs. vector control failure in venezuela may be due to the invasion of houses by silvatic populations of r. prolixus found in palms. as part of a study to determine if domestic and silvatic populations of r. prolixus are isolated, thus clarifying the role of silvatic populations in maintaining house infestations, we constru ... | 2009 | 19061974 |
| allatostatin c and its paralog allatostatin double c: the arthropod somatostatins. | arthropods do not have one, but two genes encoding an allatostatin c-like peptide. the newly discovered paralog gene was called ast-cc, and the peptide which it is predicted to make was called allatostatin double c (astcc). genes for both allatostatin c (astc) and its paralog were found in the tick ixodes scapularis as well as dipteran, lepidopteran, coleopteran, aphidoidean and phthirapteran insect species. in addition partial or complete cdnas derived from ast-ccs were found in a number of spe ... | 2009 | 19063967 |
| invitro effect of canavalia ensiformis urease and the derived peptide jaburetox-2ec on rhodnius prolixus malpighian tubules. | ureases are metalloenzymes that are widespread among plants, fungi and bacteria. urease isoforms (jack bean urease-jbu and canatoxin) from canavalia ensiformis seeds are toxic to insects and fungi, suggesting a role in plant defense. the entomotoxic effect is due to the release of a 10-kda peptide by cathepsin-like enzymes in the insect's midgut. urease causes a decrease in post-feeding weight loss in rhodnius prolixus, suggesting an effect on water balance. to investigate how this impairment oc ... | 2009 | 19121321 |
| haplotype identification within trypanosoma cruzi i in colombian isolates from several reservoirs, vectors and humans. | genetic variability in the trypanosoma cruzi i group has recently been revealed in colombian isolates from humans, reservoirs and vectors. genomic rearrangements and the polymorphic regions in taxonomic markers, such as the miniexon gene, have led to the development of molecular tools to identify phylogenetic haplotypes in t. cruzi isolates. from genetic polymorphisms found in t. cruzi i isolates, they have been classified into four haplotypes according to their epidemiologic transmission cycles ... | 2009 | 19135020 |
| physalin b inhibits rhodnius prolixus hemocyte phagocytosis and microaggregation by the activation of endogenous paf-acetyl hydrolase activities. | the effects of physalin b (a natural secosteroidal chemical from physalis angulata, solanaceae) on phagocytosis and microaggregation by hemocytes of 5th-instar larvae of rhodnius prolixus were investigated. in this insect, hemocyte phagocytosis and microaggregation are known to be induced by the platelet-activating factor (paf) or arachidonic acid (aa) and regulated by phospholipase a(2) (pla(2)) and paf-acetyl hydrolase (paf-ah) activities. phagocytic activity and formation of hemocyte microagg ... | 2009 | 19232405 |
| state-dependency of host-seeking in rhodnius prolixus: the post-ecdysis time. | the source of blood of most haematophagous insects plays at the same time the double role of host and potential predator. feeding behaviour should be triggered only when necessary and should be completed as quickly as possible. from an epidemiological point of view, this modulation has an impact on the feeding frequency of disease vectors and, as a consequence, on the transmission of parasites. at present, not many data are available on the influence of the physiological state on the motivation ... | 2009 | 19418597 |
| diuretic and antidiuretic hormones in the blood-gorging bug rhodnius prolixus. | insect salt and water homeostasis is controlled by diuretic and antidiuretic hormones that can act upon the malpighian tubules, midgut, and hindgut. much is known about the physiological events stimulating diuresis and their signaling cascades; however, the factors inhibiting diuresis are less well known. an endogenous peptide in rhodnius prolixus inhibits absorption by the anterior midgut and secretion from the malpighian tubules. we have cloned the gene, sequenced this antidiuretic peptide, an ... | 2009 | 19456399 |
| the metasternal and brindley's glands of triatoma brasiliensis neiva (hemiptera: reduviidae). | triatoma brasiliensis neiva is the most important vector of the chagas' disease in the semiarid zones of north-eastern brazil. adult bugs have two main pairs of exocrine glands, the metasternal and the brindley's glands, which release volatiles possibly with defense, alarm and/or mating functions. to date, anatomical and histological studies of the metasternal and the brindley's glands in the genus triatoma are scarce and, considering the relevance of these exocrine glands, the present work aime ... | 2009 | 19488512 |
| the role of salivary and intestinal complement system inhibitors in the midgut protection of triatomines and mosquitoes. | saliva of haematophagous arthropods contain biomolecules involved directly or indirectly with the haematophagy process, and among them are encountered some complement system inhibitors. the most obvious function for these inhibitors would be the protection of the midgut against injury by the complement. to investigate this hypothesis, triatoma brasiliensis nymphs were forced to ingest human serum in conditions in which the protection of midgut by the inhibitors is bypassed. in these conditions, ... | 2009 | 19557176 |
| trypanosoma rangeli: a new perspective for studying the modulation of immune reactions of rhodnius prolixus. | abstract: insects are exposed to a wide range of microorganisms (bacteria, fungi, parasites and viruses) and have interconnected powerful immune reactions. although insects lack an acquired immune system they have well-developed innate immune defences that allow a general and rapid response to infectious agents.over the last few decades we have observed a dramatic increase in the knowledge of insect innate immunity, which relies on both humoral and cellular responses. however, innate reactions t ... | 2009 | 19615044 |
| transmission dynamics of trypanosoma cruzi determined by low-stringency single primer polymerase chain reaction and southern blot analyses in four indigenous communities of the sierra nevada de santa marta, colombia. | this study attempted to evaluate the transmission dynamics of trypanosoma cruzi in four indigenous communities of sierra nevada de santa marta (snsm), colombia. low-stringency single primer-polymerase chain reaction (lssp-pcr) of the minicircles and southern blot analyses were used to characterize samples from patients, vectors, and reservoirs in these communities. the lssp-pcr profiles revealed a high genetic variability but with similarities among the parasites present in the samples of vector ... | 2009 | 19706903 |
| biology, diversity and strategies for the monitoring and control of triatomines--chagas disease vectors. | despite the relevant achievements in the control of the main chagas disease vectors triatoma infestans and rhodnius prolixus, several factors still promote the risk of infection. the disease is a real threat to the poor rural regions of several countries in latin america. the current situation in brazil requires renewed attention due to its high diversity of triatomine species and to the rapid and drastic environmental changes that are occurring. using the biology, behaviour and diversity of tri ... | 2009 | 19753457 |
| sylvatic triatominae: a new challenge in vector control transmission. | over the last 10 years, uruguay, chile and brazil have been certified as being free from disease transmission by triatoma infestans, the main domiciliated vector for chagas disease in the southern cone countries. this demonstrates that programmes addressing the vector for the disease's transmission are effective. these programmes have resulted in a dramatic decrease in the incidence of chagas disease in latin america. guatemala was certified a few months ago as being free from disease transmissi ... | 2009 | 19753461 |
| in vitro and in vivo documentation of quantum dots labeled trypanosoma cruzi--rhodnius prolixus interaction using confocal microscopy. | semiconductor quantum dots (qds) are highly fluorescent nanocrystals markers that allow long photobleaching and do not destroy the parasites. in this paper, we used fluorescent core shell quantum dots to perform studies of live parasite-vector interaction processes without any observable effect on the vitality of parasites. these nanocrystals were synthesized in aqueous medium and physiological ph, which is very important for monitoring live cells activities, and conjugated with molecules such a ... | 2009 | 19756738 |
| attraction of triatoma dimidiata and rhodnius prolixus (hemiptera: reduviidae) to combinations of host cues tested at two distances. | the "kissing bugs," triatoma dimidiata (latreille) and rhodnius prolixus (stål) (reduviidae: triatominae) are major vectors of chagas disease in central and south america. to further uncover the attraction to certain host cues by these vectors at long and short distances from their host, the behavioral responses of two life stages (fifth-instar nymphs and adult males) of these two species to different known or suspected attractants, alone or in combination, were investigated. tests were done usi ... | 2009 | 19769037 |
| genomic resources for invertebrate vectors of human pathogens, and the role of vectorbase. | high-throughput genome sequencing techniques have now reached vector biology with an emphasis on those species that are vectors of human pathogens. the first mosquito to be sequenced was anopheles gambiae, the vector for plasmodium parasites that cause malaria. further mosquitoes have followed: aedes aegypti (yellow fever and dengue fever vector) and culex pipiens (lymphatic filariasis and west nile fever). species that are currently in sequencing include the body louse pediculus humanus (typhus ... | 2009 | 18262474 |
| trypanosoma cruzi congenital transmission in wild bats. | trypanosoma cruzi congenital transmission in wild bats (molossus molossus), associated with infected rhodnius prolixus in a natural habitat from a rural locality in western venezuela, is reported. t. cruzi blood circulating trypomastigotes in a pregnant bat were detected by parasitological methods. polymerase chain reaction (pcr) assays carried out in samples from the heart and the fetus of the same infected female, revealed the presence of t. cruzi-specific dna in both of the tissues, demonstra ... | 2009 | 18823929 |
| oral transmission of trypanosoma cruzi with opposing evidence for the theory of carnivory. | we present the first demonstration of oral transmission of trypanosoma cruzi to raccoons (procyon lotor), a natural reservoir host in the united states, by ingestion of trypomastigotes and infected bugs, but not infected tissue. to investigate an alternative, non-vector-based transmission method, we tested the hypothesis that raccoons scavenging on infected hosts results in patent infection. macerated tissue from selected organs infected with amastigote stages of t. cruzi was orally administered ... | 2009 | 18763853 |
| trypanosoma rangeli genotypes association with rhodnius prolixus and r. pallescens allopatric distribution in central america. | previous kdna polymorphism-based reports have revealed the existence of two trypanosoma rangeli genotypes (kp1+ and kp1-): sl and ssu rrna gene polymorphism-based studies have revealed that five genotypes (a-e) are distributed throughout different latin-american countries. some evidence has shown that the genotypes' biogeographical distribution is associated with sympatric rhodnius species. 12 t. rangeli isolates from humans and reservoirs from el salvador, guatemala, honduras, costa rica and pa ... | 2009 | 19778637 |
| immunogenic salivary proteins of triatoma infestans: development of a recombinant antigen for the detection of low-level infestation of triatomines. | triatomines are vectors of trypanosoma cruzi, the etiological agent of chagas disease in latin america. the most effective vector, triatoma infestans, has been controlled successfully in much of latin america using insecticide spraying. though rarely undertaken, surveillance programs are necessary in order to identify new infestations and estimate the intensity of triatomine bug infestations in domestic and peridomestic habitats. since hosts exposed to triatomines develop immune responses to sal ... | 2009 | 19841746 |
| behavioral and electrophysiological responses of triatoma brasiliensis males to volatiles produced in the metasternal glands of females. | in many insects, mate finding is mediated by volatile sex pheromones, but evidence for this phenomenon in triatomines (heteroptera: reduviidae) is still fragmentary. recently, it was shown that metasternal glands (mgs) are involved in producing signals related to the sexual communication of triatoma infestans and rhodnius prolixus. based on this, we tested whether mg volatiles could be involved in the sexual communication of triatoma brasiliensis. odor-mediated orientation responses were studied ... | 2009 | 19902303 |
| the triatominae species of french guiana (heteroptera: reduviidae). | an annotated list of the triatomine species present in french guiana is given. it is based on field collections carried out between 1993-2008, museum collections and a literature review. fourteen species, representing four tribes and six genera, are now known in this country and are illustrated (habitus). three species are recorded from french guiana for the first time: cavernicola pilosa, microtriatoma trinidadensis and rhodnius paraensis. the two most common and widely distributed species are ... | 2009 | 20140371 |
| physiological activity of neuropeptide f on the hindgut of the blood-feeding hemipteran, rhodnius prolixus. | current hypotheses propose that, in the invertebrates, neuropeptide f (npf), the vertebrate npy homologue, may be capable of regulating responses to diverse cues related to nutritional status and feeding. an investigation into the effects of drosophila melanogaster npf (drmnpf) and anopheles gambiae npf (angnpf) on hindgut physiology of rhodnius prolixus stal (heimptera: reduviidae) suggests a myoinhibitory role for these peptides and the r. prolixus native peptide. extracts of the central nervo ... | 2009 | 20050776 |
| alpha-glucosidase promotes hemozoin formation in a blood-sucking bug: an evolutionary history. | hematophagous insects digest large amounts of host hemoglobin and release heme inside their guts. in rhodnius prolixus, hemoglobin-derived heme is detoxified by biomineralization, forming hemozoin (hz). recently, the involvement of the r. prolixus perimicrovillar membranes in hz formation was demonstrated. | 2009 | 19742319 |
| [action of insect growth inhibitors on aedes aegypti l. mosquitoes and rhodnius prolixus stal. bugs. iii. the activity of diarylidene cyclonones]. | 2009 | 364291 | |
| isolation, expression analysis, and functional characterization of the first antidiuretic hormone receptor in insects. | diuresis following blood-gorging in rhodnius prolixus is the major process leading to the transmission of chagas' disease. we have cloned the cdna of the first receptor known to be involved in an antidiuretic strategy in insects, a strategy that prevents diuresis. this receptor belongs to the insect capa receptor family known in other insects to be activated by peptides encoded within the capability gene. we characterize the expression profile in fifth-instars and find expression is localized to ... | 2010 | 20479227 |
| cytogenetics and genome evolution in the subfamily triatominae (hemiptera, reduviidae). | the subfamily triatominae (hemiptera, reduviidae), vectors of chagas disease, includes over 140 species. karyotypic information is currently available for 80 of these species. this paper summarizes the chromosomal variability of the subfamily and how it may reveal aspects of genome evolution in this group. the triatominae present a highly conserved chromosome number. all species, except 3, present 20 autosomes. the differences in chromosome number are mainly caused by variation in the number of ... | 2010 | 20407223 |
| trypanosoma cruzi: synergistic cytotoxicity of multiple amphipathic anti-microbial peptides to t. cruzi and potential bacterial hosts. | the parasite trypanasoma cruzi is responsible for chagas disease and its triatomine vector, rhodnius prolixus, has a symbiotic relationship with the soil bacterium, rhodococcus rhodnii. r. rhodnii that was previously genetically engineered to produce the anti-microbial peptide, cecropin a was co-infected with t. cruzi into r. prolixus resulting in clearance of the infectious t. cruzi in 65% of the vectors. similar anti-microbial peptides have been isolated elsewhere and were studied for differen ... | 2010 | 20206169 |
| trypanosoma rangeli: differential expression of ecto-phosphatase activities in response to inorganic phosphate starvation. | in this work, we showed that living cells of trypanosoma rangeli express different ecto-phosphatase activities in response to different inorganic phosphate (pi) concentrations in the culture medium. the ecto-phosphatase activity from t. rangeli grown at low-pi concentration was inhibited by the increase of the ph, while the ecto-phosphatase of the cells grown at high pi concentration was not modulated by the change of the ph of the medium. okadaic acid inhibited only the ecto-phosphatase activit ... | 2010 | 20034491 |
| discovery of a novel insect neuropeptide signaling system closely related to the insect adipokinetic hormone and corazonin hormonal systems. | neuropeptides and their g protein-coupled receptors (gpcrs) play a central role in the physiology of insects. one large family of insect neuropeptides are the adipokinetic hormones (akhs), which mobilize lipids and carbohydrates from the insect fat body. other peptides are the corazonins that are structurally related to the akhs but represent a different neuropeptide signaling system. we have previously cloned an orphan gpcr from the malaria mosquito anopheles gambiae that was structurally inter ... | 2010 | 20068045 |
| nitrophorin 2, a factor ix(a)-directed anticoagulant, inhibits arterial thrombosis without impairing haemostasis. | nitrophorin 2 (np2) is a 20 kda lipocalin identified in the salivary gland of the blood sucking insect, rhodnius prolixus. it functions as a potent inhibitor of the intrinsic pathway of coagulation upon binding to factor ix (fix) or fixa. herein we have investigated the in vivo antithrombotic properties of np2. surface plasmon resonance assays demonstrated that np2 binds to rat fix and fixa with high affinities (kd = 43 and 47 nm, respectively), and prolongs the aptt without affecting the pt. in ... | 2010 | 20838739 |
| the control of malpighian tubule secretion in a predacious hemipteran insect, the spined soldier bug podisus maculiventris (heteroptera, pentatomidae). | spined soldier bugs, podisus maculiventris, are heteropteran insects that feed voraciously on other insects, particular the soft bodied larval forms of lepidoptera and coleoptera. the response of p. maculiventris malpighian tubules (mts) to serotonin and known diuretic and antidiuretic peptides has been investigated, and is compared with that of mt from the hematophagous and phytophagous heteropteran bugs rhodnius prolixus and acrosternum hilare, respectively. a crf-related peptide diuretic horm ... | 2010 | 21093508 |
| effects of platelet-activating factor on the interaction of trypanosoma cruzi with rhodnius prolixus. | we investigated the effects of platelet-activating factor (paf) on the interaction of trypanosoma cruzi with rhodnius prolixus. the parasites (epimastigotes) were treated with paf and/or web 2086 (paf antagonist) for 1 h prior to the interaction experiments. paf stimulated both in vivo and ex vivo interactions between t. cruzi and r. prolixus while web 2086 abrogated these effects. paf-treated epimastigotes also showed an increase in surface negativity and in the amount of surface sialic acid. n ... | 2010 | 21161276 |
| preliminary evidence of rhodnius prolixus (hemiptera: triatominae) attraction to human skin odour extracts. | host-seeking behaviour displayed by the haematophagous triatomine rhodnius prolixus stål, 1859 is influenced by different cues involving heat, moisture and odours. concentrations of volatile odours present in human sweat and breath that activate, attract or non-attract triatomines were tested behaviourally with a double choice olfactometer in adults of r. prolixus. attraction of a mixture of substances carried by a controlled air-stream was established and compared with volatiles from human extr ... | 2010 | 19879853 |
| a role for host-parasite interactions in the horizontal transfer of transposons across phyla. | horizontal transfer (ht), or the passage of genetic material between non-mating species, is increasingly recognized as an important force in the evolution of eukaryotic genomes. transposons, with their inherent ability to mobilize and amplify within genomes, may be especially prone to ht. however, the means by which transposons can spread across widely diverged species remain elusive. here we present evidence that host-parasite interactions have promoted the ht of four transposon families betwee ... | 2010 | 20428170 |
| primary culture of rhodnius prolixus (hemiptera: reduviidae) salivary gland cells. | in the present paper, we developed a primary culture of rhodnius prolixus salivary gland and main salivary canal cells. cells remained viable in culture for 30 days. three types of cells were indentified in the salivary gland cultures, with binuclear cells being the most abundant. the supernatants of salivary cultures contained mainly 16-24 kda proteins and presented anticoagulant and apyrase activities. secretion vesicles were observed budding from the cellular monolayer of the main salivary ca ... | 2010 | 20428670 |
| morphometry and morphology of the antennae of panstrongylus megistus burmeister, rhodnius neglectus lent, rhodnius prolixus stal and triatoma vitticeps stal (hemiptera: reduviidae). | the length of the four right antennal segments from nymphs and adults of panstrongylus megistus burmeister, rhodnius neglectus lent, rhodnius prolixus stal and triatoma vitticeps stal were measured. the length of the antennal segments of the adults of all four species, 4th and 5th instars of p. megistus, and 5th instar of r. neglectus and r. prolixus followed the same pattern: 2nd>3rd>4th>1st. the pattern of 1st and 2nd instars of p. megistus was: 4th>3rd>2nd>1st. for 3rd instars of p. megistus, ... | 2010 | 20498958 |
| feeding through artificial membranes reduces fecundity for females of the blood-feeding insect, rhodnius prolixus. | the blood-feeding insect, rhodnius prolixus, has been raised in the laboratory for close to 100 years. various feeding techniques have been employed ranging from the use of warm-blooded hosts, to the use of previously collected blood offered through artificial membranes. this study compared the fecundity in mated and unmated females fed rabbit blood directly from the shaved belly of a rabbit to that of females fed defibrinated rabbit blood through an artificial membrane. these results confirm pr ... | 2010 | 20513058 |
| commercial coconut palm as an ecotope of chagas disease vectors in north-eastern venezuela. | there are few reports of coccus nucifera (palmae) infestation by triatomines (hemiptera, reduviidae, triatominae), vectors of trypanosoma cruzi (kinetoplastida: trypanosomatidae), the causal agent of american trypanosomiasis. the aim of this study was to determine if this palm is an appropriate ecotope for rhodnius prolixus and triatoma maculata, the main vectors in venezuela. | 2010 | 20539044 |
| a standardizable protocol for infection of rhodnius prolixus with trypanosoma rangeli, which mimics natural infections and reveals physiological effects of infection upon the insect. | trypanosoma rangeli is a protozoan parasite that shares hosts - mammals and triatomines - with trypanosoma cruzi, the etiological agent of chagas disease. although t. rangeli is customarily considered to be non-pathogenic to human hosts, it is able to produce pathologies in its invertebrate hosts. however, advances are hindered by a lack of standardization of infection procedures and these pathologies need documentation. to establish a suitable, and standardizable, infection protocol, the durati ... | 2010 | 20546751 |
| cuticular plasticization in the tick, amblyomma hebraeum (acari: ixodidae): possible roles of monoamines and cuticular ph. | the degree of plasticization of the alloscutal cuticle of a 'hard' (ixodid) tick, amblyomma hebraeum, and a 'soft' (argasid) tick, ornithodoros moubata, was assessed throughout the blood-feeding period. cuticle viscosity was calculated from rate of creep of cuticle under constant load using a maxwell model. feeding-related plasticization (i.e. increased rate of extension under a constant load) occurred in a. hebraeum but not in o. moubata. maxwell viscosity of unfed a. hebraeum cuticle was relat ... | 2010 | 20675552 |
| validation of a less invasive blood sampling technique in rabies serology using reduviid bugs (triatominae, hemiptera). | during serologic rabies surveys, bleeding is often difficult or almost impossible in small or endangered mammals such as bats. therefore, the usefulness of an alternative, less invasive technique--that is, the use of blood-sucking reduviid bugs (dipetalogaster maximus and rhodnius prolixus)--was investigated. bugs were used in combination with a conventional method (retro-orbitale bleeding) to obtain blood samples from the same individual nmri-mice (mus musculus) vaccinated against rabies. rabie ... | 2010 | 20722255 |
| genetic variability and phylogenetic relationships within trypanosoma cruzi i isolated in colombia based on miniexon gene sequences. | phylogenetic studies of trypanosoma cruzi have identified the existence of two groups: t. cruzi i and t. cruzi ii. there are aspects that still remain unknown about the genetic variability within the t. cruzi i group. given its epidemiological importance, it is necessary to have a better understanding of t. cruzi transmission cycles. our purpose was to corroborate the existence of haplotypes within the t. cruzi i group and to describe the genetic variability and phylogenetic relationships, based ... | 2010 | 20798881 |
| paralytic activity of lysophosphatidylcholine from saliva of the waterbug belostoma anurum. | lysophosphatidylcholine (lpc) is a major bioactive lipid that is enzymatically generated by phospholipase a(2) (pla(2)). previously, we showed that lpc is present in the saliva of the blood-sucking hemipteran rhodnius prolixus and modulates cell-signaling pathways involved in vascular biology, which aids blood feeding. here, we show that the saliva of the predator insect belostoma anurum contains a large number of lipids with lpc accounting for 25% of the total phospholipids. a pla(2) enzyme lik ... | 2010 | 20833923 |
| sn-protoporphyrin inhibits both heme degradation and hemozoin formation in rhodnius prolixus midgut. | hematophagy is a feeding habit that involves the ingestion of huge amounts of heme. the hematophagous hemipteran rhodnius prolixus evolved many genetic resources to protect cells against heme toxicity. the primary barrier against the deleterious effects of heme is the aggregation of heme into hemozoin in the midgut lumen. hemozoin formation is followed by the enzymatic degradation of heme by means of a unique pathway whose end product is dicysteinyl-biliverdin ix-γ (rhodnius prolixus biliverdin, ... | 2010 | 20851767 |
| [genetic differentiation of three colombian populations of triatoma dimidiata (heteroptera: reduviidae) by nd4 mitochondrial gene molecular analysis]. | triatoma dimidiata is the second most important vector of chagas disease in colombia after rhodnius prolixus. population genetic studies are essential for the adequate design and implementation of vector control and surveillance strategies. | 2010 | 20890568 |
| neuropeptide precursor gene discovery in the chagas disease vector rhodnius prolixus. | we show a straightforward workflow combining homology search in rhodnius prolixus genome sequence with cloning by rapid amplification of cdna ends and mass spectrometry. we have identified 32 genes and their transcripts that encode a number of neuropeptide precursors leading to 194 putative peptides. we validated by mass spectrometry 82 of those predicted neuropeptides in the brain of r. prolixus to achieve the first comprehensive genomic, transcriptomic and neuropeptidomic analysis of an insect ... | 2010 | 20958806 |
| neurohormones implicated in the control of malpighian tubule secretion in plant sucking heteropterans: the stink bugs acrosternum hilare and nezara viridula. | plant sucking heteropteran bugs feed regularly on small amounts of k(+)-rich plant material, in contrast to their hematophagous relatives which imbibe large volumes of na(+)-rich blood. it was anticipated that this would be reflected in the endocrine control of malpighian tubule (mt) secretion. to explore this, neuroendocrine factors known to influence mt secretion were tested on mt of the pentatomid plant sucking stink bugs, acrosternum hilare and nezara viridula, and the results compared with ... | 2010 | 19772880 |
| flight initiation by male rhodnius prolixus is promoted by female odors. | several triatomine bug species utilize chemical cues for sexual communication. we tested whether female or male rhodnius prolixus, a vector of chagas disease, produce volatile chemicals that elicit flight responses from conspecifics, and then isolated the source of the chemical. males confronted with an airstream containing female odors showed a significantly greater take-off frequency compared to a blank airstream or an airstream with male odors. in contrast, females exhibited similar take-off ... | 2010 | 20352301 |
| two capa-genes are expressed in the neuroendocrine system of rhodnius prolixus. | capa-peptides have been isolated from a broad range of insect species and are typical of the neurosecretory system of the abdominal ventral nerve cord. in rhodnius prolixus, which is known to transmit chagas' disease, capa-peptides have potent antidiuretic effects. recently, two capa-genes were isolated from this hemipteran insect; it was the first description of the occurrence of multiple capa-genes from a single insect species. the expression of peptides from one of these capa-genes was confir ... | 2010 | 19778561 |
| characterization of the external female genitalia of six species of triatominae (hemiptera: reduviidade) by scanning electron microscopy. | by macroscopic and microscopic dorsal side observation, it was noted that the ix and x segments of two species each of panstrongylus and triatoma terminate in an elongated way, whereas they terminate abruptly in the two species of rhodnius. scanning observation of the dorsal, ventral, lateral and posterior sides of the female genitalia of panstrongylus herreri, panstrongylus megistus, rhodnius colombiensis, rhodnius prolixus, triatoma infestans and triatoma vitticeps revealed that these six spec ... | 2010 | 20512241 |
| unprecedented peroxidase-like activity of rhodnius prolixus nitrophorin 2: identification of the [feiv=o por•]+ and [feiv=o por](tyr38•) intermediates and their role(s) in substrate oxidation. | we have identified a novel enzymatic reaction for nitrophorin 2 (np2), a heme protein previously characterized as a nitric oxide carrier in the saliva of the rhodnius prolixus insect. np2 exhibited levels of peroxidase activity comparable to those of the bifunctional peroxidases (katgs), despite their heme pocket structural differences (heme ruffling, tyr38 and tyr85 in hydrogen bonding interactions with the propionates in np2). the intermediates of the peroxidase-like reaction of np2 were ident ... | 2010 | 20726527 |
| formation of the complex of nitrite with the ferriheme b beta-barrel proteins nitrophorin 4 and nitrophorin 7. | the interaction of ferriheme proteins with nitrite has recently attracted interest as a source for no or other nitrogen oxides in mammalian physiology. however, met-hemoglobin (methb), which was suggested as a key player in this process, does not convert nitrite unless small amounts of no are added in parallel. we have recently reported that, in contrast, nitrophorins (nps) convert nitrite as the sole substrate to form no even at ph 7.5, which is an unprecedented case among ferrihemes [he, c., a ... | 2010 | 20524697 |
| phenol oxidases from rhodnius prolixus: temporal and tissue expression pattern and regulation by ecdysone. | rhodnius prolixus 5th instar nymphs have significant po enzymatic activity in the anterior midgut, fat body and hemolymph. the tissue with the major amount of po activity is the anterior midgut while those with higher specific activities are the fat body and hemolymph. in this work the temporal pattern of po enzymatic activity in different tissues was investigated. in fat body, po peaks occur at 7, 12 and 16 days after a blood meal. in hemolymph, po diminishes until day 7, and then recovers by d ... | 2010 | 20361973 |
| jack bean urease alters serotonin-induced effects on rhodnius prolixus anterior midgut. | urease isoforms from jack bean seeds are toxic to insects, and this entomotoxic effect is mostly due to the release of a peptide by insect digestive enzymes. we previously demonstrated that jack bean urease (jbu) has antidiuretic effects on rhodnius prolixus malpighian tubules, decreasing the serotonin-stimulated secretion of fluid. now, we evaluate the toxicity of the intact jbu and its effect on r. prolixus anterior midgut, to further elucidate the mechanism of action of jbu in insects. jbu de ... | 2010 | 20223243 |
| the circadian timing system in the brain of the fifth larval instar of rhodnius prolixus (hemiptera). | the brain of larval rhodnius prolixus releases neurohormones with a circadian rhythm, indicating that a clock system exists in the larval brain. larvae also possess a circadian locomotor rhythm. the present paper is a detailed analysis of the distribution and axonal projections of circadian clock cells in the brain of the fifth larval instar. clock cells are identified as neurons that exhibit circadian cycling of both per and tim proteins. a group of eight lateral clock neurons (lns) in the prox ... | 2010 | 20151359 |
| serotonin regulates an acyl-coa-binding protein (acbp) gene expression in the midgut of rhodnius prolixus. | acyl-coa esters have many intracellular functions, acting as energy source, substrate for metabolic processes and taking part in cell signaling. the acyl-coa-binding protein (acbp), a highly conserved 10 kda intracellular protein, binds long- and medium-chain acyl-coa esters with very high affinity, directing them to specific metabolic routes and protecting them from hydrolysis. an acbp gene sequence was identified in the genome of rhodnius prolixus. this acbp gene (rpacbp-1) was expressed in al ... | 2010 | 20079838 |
| effects of the cyclopeptide mycotoxin destruxin a on the malpighian tubules of rhodnius prolixus (stål). | the production of peptide toxins by entomopathogenic fungi during the infection process plays critical roles in pathogenesis. to gain insight into the mechanism of action of these mycotoxins on insect internal organs, we have evaluated the effects of destruxin a, a cyclic peptide produced by metarhizium anispliae, on rhodnius prolixus malpighian tubules measuring fluid secretion rate, transepithelial electrical potential (tep), ph and ion composition of secreted fluid, and atp content. destruxin ... | 2010 | 20060849 |
| on the physico-chemical and physiological requirements of hemozoin formation promoted by perimicrovillar membranes in rhodnius prolixus midgut. | triatomine insects are obligatory blood-feeders that detoxify most of the hemoglobin-derived heme through its crystallization into hemozoin (hz). previous evidence demonstrates the key role of midgut perimicrovillar membranes (pmvm) on heme crystallization in triatomines. here, we investigated some of the physico-chemical and physiological aspects of heme crystallization induced by rhodnius prolixus pmvm. hz formation in vitro proceeded optimally at ph 4.8 and 28 degrees c, apparently involving ... | 2010 | 20060043 |
| the antidiuretic neurohormone rhoprcapa-2 downregulates fluid transport across the anterior midgut in the blood-feeding insect rhodnius prolixus. | osmotic balance in insects is regulated by the excretory system, consisting of malpighian tubules and the gut under the control of diuretic and antidiuretic factors. terrestrial insects must conserve water, and antidiuresis is the norm, only interrupted by brief diuretic periods. surprisingly, little is known about antidiuresis in insects. two antidiuretic strategies have been described. the first antidiuretic mechanism involves the reabsorption of fluid from the primary urine in the hindgut. mo ... | 2010 | 20007522 |
| inorganic polyphosphate inhibits an aspartic protease-like activity in the eggs of rhodnius prolixus (stahl) and impairs yolk mobilization in vitro. | inorganic polyphosphate (poly p) is a polymer of phosphate residues that has been shown to act as modulator of some vertebrate cathepsins. in the egg yolk granules of rhodnius prolixus, a cathepsin d is the main protease involved in yolk mobilization and is dependent on an activation by acid phosphatases. in this study, we showed a possible role of poly p stored inside yolk granules on the inhibition of cathepsin d and arrest of yolk mobilization during early embryogenesis of these insects. enzy ... | 2010 | 19957302 |